/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprCXX.cpp

Bug Summary

File:	src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprCXX.cpp
Warning:	line 1247, column 28 Called C++ object pointer is null

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaExprCXX.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include/clang/Sema -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/llvm/include -I /usr/src/gnu/usr.bin/clang/libclangSema/../include -I /usr/src/gnu/usr.bin/clang/libclangSema/obj -I /usr/src/gnu/usr.bin/clang/libclangSema/obj/../include -D NDEBUG -D __STDC_LIMIT_MACROS -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D LLVM_PREFIX="/usr" -internal-isystem /usr/include/c++/v1 -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/usr/src/gnu/usr.bin/clang/libclangSema/obj -ferror-limit 19 -fvisibility-inlines-hidden -fwrapv -stack-protector 2 -fno-rtti -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c++ /usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprCXX.cpp

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaExprCXX.cpp

→

1//===--- SemaExprCXX.cpp - Semantic Analysis for Expressions --------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// Implements semantic analysis for C++ expressions.
11///
12//===----------------------------------------------------------------------===//

14#include "clang/Sema/Template.h"
15#include "clang/Sema/SemaInternal.h"
16#include "TreeTransform.h"
17#include "TypeLocBuilder.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/ASTLambda.h"
20#include "clang/AST/CXXInheritance.h"
21#include "clang/AST/CharUnits.h"
22#include "clang/AST/DeclObjC.h"
23#include "clang/AST/ExprCXX.h"
24#include "clang/AST/ExprObjC.h"
25#include "clang/AST/RecursiveASTVisitor.h"
26#include "clang/AST/TypeLoc.h"
27#include "clang/Basic/AlignedAllocation.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/TargetInfo.h"
30#include "clang/Lex/Preprocessor.h"
31#include "clang/Sema/DeclSpec.h"
32#include "clang/Sema/Initialization.h"
33#include "clang/Sema/Lookup.h"
34#include "clang/Sema/ParsedTemplate.h"
35#include "clang/Sema/Scope.h"
36#include "clang/Sema/ScopeInfo.h"
37#include "clang/Sema/SemaLambda.h"
38#include "clang/Sema/TemplateDeduction.h"
39#include "llvm/ADT/APInt.h"
40#include "llvm/ADT/STLExtras.h"
41#include "llvm/Support/ErrorHandling.h"
42using namespace clang;
43using namespace sema;

45/// Handle the result of the special case name lookup for inheriting
46/// constructor declarations. 'NS::X::X' and 'NS::X<...>::X' are treated as
47/// constructor names in member using declarations, even if 'X' is not the
48/// name of the corresponding type.
49ParsedType Sema::getInheritingConstructorName(CXXScopeSpec &SS,
                                            SourceLocation NameLoc,
                                            IdentifierInfo &Name) {
NestedNameSpecifier *NNS = SS.getScopeRep();

// Convert the nested-name-specifier into a type.
QualType Type;
switch (NNS->getKind()) {
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
  Type = QualType(NNS->getAsType(), 0);
  break;

case NestedNameSpecifier::Identifier:
  // Strip off the last layer of the nested-name-specifier and build a
  // typename type for it.
  assert(NNS->getAsIdentifier() == &Name && "not a constructor name")((void)0);
  Type = Context.getDependentNameType(ETK_None, NNS->getPrefix(),
                                      NNS->getAsIdentifier());
  break;

case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
  llvm_unreachable("Nested name specifier is not a type for inheriting ctor")__builtin_unreachable();
}

// This reference to the type is located entirely at the location of the
// final identifier in the qualified-id.
return CreateParsedType(Type,
                        Context.getTrivialTypeSourceInfo(Type, NameLoc));
81}

83ParsedType Sema::getConstructorName(IdentifierInfo &II,
                                  SourceLocation NameLoc,
                                  Scope *S, CXXScopeSpec &SS,
                                  bool EnteringContext) {
CXXRecordDecl *CurClass = getCurrentClass(S, &SS);
assert(CurClass && &II == CurClass->getIdentifier() &&((void)0)
       "not a constructor name")((void)0);

// When naming a constructor as a member of a dependent context (eg, in a
// friend declaration or an inherited constructor declaration), form an
// unresolved "typename" type.
if (CurClass->isDependentContext() && !EnteringContext && SS.getScopeRep()) {
  QualType T = Context.getDependentNameType(ETK_None, SS.getScopeRep(), &II);
  return ParsedType::make(T);
}

if (SS.isNotEmpty() && RequireCompleteDeclContext(SS, CurClass))
  return ParsedType();

// Find the injected-class-name declaration. Note that we make no attempt to
// diagnose cases where the injected-class-name is shadowed: the only
// declaration that can validly shadow the injected-class-name is a
// non-static data member, and if the class contains both a non-static data
// member and a constructor then it is ill-formed (we check that in
// CheckCompletedCXXClass).
CXXRecordDecl *InjectedClassName = nullptr;
for (NamedDecl *ND : CurClass->lookup(&II)) {
  auto *RD = dyn_cast<CXXRecordDecl>(ND);
  if (RD && RD->isInjectedClassName()) {
    InjectedClassName = RD;
    break;
  }
}
if (!InjectedClassName) {
  if (!CurClass->isInvalidDecl()) {
    // FIXME: RequireCompleteDeclContext doesn't check dependent contexts
    // properly. Work around it here for now.
    Diag(SS.getLastQualifierNameLoc(),
         diag::err_incomplete_nested_name_spec) << CurClass << SS.getRange();
  }
  return ParsedType();
}

QualType T = Context.getTypeDeclType(InjectedClassName);
DiagnoseUseOfDecl(InjectedClassName, NameLoc);
MarkAnyDeclReferenced(NameLoc, InjectedClassName, /*OdrUse=*/false);

return ParsedType::make(T);
131}

133ParsedType Sema::getDestructorName(SourceLocation TildeLoc,
                                 IdentifierInfo &II,
                                 SourceLocation NameLoc,
                                 Scope *S, CXXScopeSpec &SS,
                                 ParsedType ObjectTypePtr,
                                 bool EnteringContext) {
// Determine where to perform name lookup.

// FIXME: This area of the standard is very messy, and the current
// wording is rather unclear about which scopes we search for the
// destructor name; see core issues 399 and 555. Issue 399 in
// particular shows where the current description of destructor name
// lookup is completely out of line with existing practice, e.g.,
// this appears to be ill-formed:
//
//   namespace N {
//     template <typename T> struct S {
//       ~S();
//     };
//   }
//
//   void f(N::S<int>* s) {
//     s->N::S<int>::~S();
//   }
//
// See also PR6358 and PR6359.
//
// For now, we accept all the cases in which the name given could plausibly
// be interpreted as a correct destructor name, issuing off-by-default
// extension diagnostics on the cases that don't strictly conform to the
// C++20 rules. This basically means we always consider looking in the
// nested-name-specifier prefix, the complete nested-name-specifier, and
// the scope, and accept if we find the expected type in any of the three
// places.

if (SS.isInvalid())
  return nullptr;

// Whether we've failed with a diagnostic already.
bool Failed = false;

llvm::SmallVector<NamedDecl*, 8> FoundDecls;
llvm::SmallPtrSet<CanonicalDeclPtr<Decl>, 8> FoundDeclSet;

// If we have an object type, it's because we are in a
// pseudo-destructor-expression or a member access expression, and
// we know what type we're looking for.
QualType SearchType =
    ObjectTypePtr ? GetTypeFromParser(ObjectTypePtr) : QualType();

auto CheckLookupResult = [&](LookupResult &Found) -> ParsedType {
  auto IsAcceptableResult = [&](NamedDecl *D) -> bool {
    auto *Type = dyn_cast<TypeDecl>(D->getUnderlyingDecl());
    if (!Type)
      return false;

    if (SearchType.isNull() || SearchType->isDependentType())
      return true;

    QualType T = Context.getTypeDeclType(Type);
    return Context.hasSameUnqualifiedType(T, SearchType);
  };

  unsigned NumAcceptableResults = 0;
  for (NamedDecl *D : Found) {
    if (IsAcceptableResult(D))
      ++NumAcceptableResults;

    // Don't list a class twice in the lookup failure diagnostic if it's
    // found by both its injected-class-name and by the name in the enclosing
    // scope.
    if (auto *RD = dyn_cast<CXXRecordDecl>(D))
      if (RD->isInjectedClassName())
        D = cast<NamedDecl>(RD->getParent());

    if (FoundDeclSet.insert(D).second)
      FoundDecls.push_back(D);
  }

  // As an extension, attempt to "fix" an ambiguity by erasing all non-type
  // results, and all non-matching results if we have a search type. It's not
  // clear what the right behavior is if destructor lookup hits an ambiguity,
  // but other compilers do generally accept at least some kinds of
  // ambiguity.
  if (Found.isAmbiguous() && NumAcceptableResults == 1) {
    Diag(NameLoc, diag::ext_dtor_name_ambiguous);
    LookupResult::Filter F = Found.makeFilter();
    while (F.hasNext()) {
      NamedDecl *D = F.next();
      if (auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
        Diag(D->getLocation(), diag::note_destructor_type_here)
            << Context.getTypeDeclType(TD);
      else
        Diag(D->getLocation(), diag::note_destructor_nontype_here);

      if (!IsAcceptableResult(D))
        F.erase();
    }
    F.done();
  }

  if (Found.isAmbiguous())
    Failed = true;

  if (TypeDecl *Type = Found.getAsSingle<TypeDecl>()) {
    if (IsAcceptableResult(Type)) {
      QualType T = Context.getTypeDeclType(Type);
      MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
      return CreateParsedType(T,
                              Context.getTrivialTypeSourceInfo(T, NameLoc));
    }
  }

  return nullptr;
};

bool IsDependent = false;

auto LookupInObjectType = [&]() -> ParsedType {
  if (Failed || SearchType.isNull())
    return nullptr;

  IsDependent |= SearchType->isDependentType();

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  DeclContext *LookupCtx = computeDeclContext(SearchType);
  if (!LookupCtx)
    return nullptr;
  LookupQualifiedName(Found, LookupCtx);
  return CheckLookupResult(Found);
};

auto LookupInNestedNameSpec = [&](CXXScopeSpec &LookupSS) -> ParsedType {
  if (Failed)
    return nullptr;

  IsDependent |= isDependentScopeSpecifier(LookupSS);
  DeclContext *LookupCtx = computeDeclContext(LookupSS, EnteringContext);
  if (!LookupCtx)
    return nullptr;

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  if (RequireCompleteDeclContext(LookupSS, LookupCtx)) {
    Failed = true;
    return nullptr;
  }
  LookupQualifiedName(Found, LookupCtx);
  return CheckLookupResult(Found);
};

auto LookupInScope = [&]() -> ParsedType {
  if (Failed || !S)
    return nullptr;

  LookupResult Found(*this, &II, NameLoc, LookupDestructorName);
  LookupName(Found, S);
  return CheckLookupResult(Found);
};

// C++2a [basic.lookup.qual]p6:
//   In a qualified-id of the form
//
//     nested-name-specifier[opt] type-name :: ~ type-name
//
//   the second type-name is looked up in the same scope as the first.
//
// We interpret this as meaning that if you do a dual-scope lookup for the
// first name, you also do a dual-scope lookup for the second name, per
// C++ [basic.lookup.classref]p4:
//
//   If the id-expression in a class member access is a qualified-id of the
//   form
//
//     class-name-or-namespace-name :: ...
//
//   the class-name-or-namespace-name following the . or -> is first looked
//   up in the class of the object expression and the name, if found, is used.
//   Otherwise, it is looked up in the context of the entire
//   postfix-expression.
//
// This looks in the same scopes as for an unqualified destructor name:
//
// C++ [basic.lookup.classref]p3:
//   If the unqualified-id is ~ type-name, the type-name is looked up
//   in the context of the entire postfix-expression. If the type T
//   of the object expression is of a class type C, the type-name is
//   also looked up in the scope of class C. At least one of the
//   lookups shall find a name that refers to cv T.
//
// FIXME: The intent is unclear here. Should type-name::~type-name look in
// the scope anyway if it finds a non-matching name declared in the class?
// If both lookups succeed and find a dependent result, which result should
// we retain? (Same question for p->~type-name().)

if (NestedNameSpecifier *Prefix =
    SS.isSet() ? SS.getScopeRep()->getPrefix() : nullptr) {
  // This is
  //
  //   nested-name-specifier type-name :: ~ type-name
  //
  // Look for the second type-name in the nested-name-specifier.
  CXXScopeSpec PrefixSS;
  PrefixSS.Adopt(NestedNameSpecifierLoc(Prefix, SS.location_data()));
  if (ParsedType T = LookupInNestedNameSpec(PrefixSS))
    return T;
} else {
  // This is one of
  //
  //   type-name :: ~ type-name
  //   ~ type-name
  //
  // Look in the scope and (if any) the object type.
  if (ParsedType T = LookupInScope())
    return T;
  if (ParsedType T = LookupInObjectType())
    return T;
}

if (Failed)
  return nullptr;

if (IsDependent) {
  // We didn't find our type, but that's OK: it's dependent anyway.

  // FIXME: What if we have no nested-name-specifier?
  QualType T = CheckTypenameType(ETK_None, SourceLocation(),
                                 SS.getWithLocInContext(Context),
                                 II, NameLoc);
  return ParsedType::make(T);
}

// The remaining cases are all non-standard extensions imitating the behavior
// of various other compilers.
unsigned NumNonExtensionDecls = FoundDecls.size();

if (SS.isSet()) {
  // For compatibility with older broken C++ rules and existing code,
  //
  //   nested-name-specifier :: ~ type-name
  //
  // also looks for type-name within the nested-name-specifier.
  if (ParsedType T = LookupInNestedNameSpec(SS)) {
    Diag(SS.getEndLoc(), diag::ext_dtor_named_in_wrong_scope)
        << SS.getRange()
        << FixItHint::CreateInsertion(SS.getEndLoc(),
                                      ("::" + II.getName()).str());
    return T;
  }

  // For compatibility with other compilers and older versions of Clang,
  //
  //   nested-name-specifier type-name :: ~ type-name
  //
  // also looks for type-name in the scope. Unfortunately, we can't
  // reasonably apply this fallback for dependent nested-name-specifiers.
  if (SS.getScopeRep()->getPrefix()) {
    if (ParsedType T = LookupInScope()) {
      Diag(SS.getEndLoc(), diag::ext_qualified_dtor_named_in_lexical_scope)
          << FixItHint::CreateRemoval(SS.getRange());
      Diag(FoundDecls.back()->getLocation(), diag::note_destructor_type_here)
          << GetTypeFromParser(T);
      return T;
    }
  }
}

// We didn't find anything matching; tell the user what we did find (if
// anything).

// Don't tell the user about declarations we shouldn't have found.
FoundDecls.resize(NumNonExtensionDecls);

// List types before non-types.
std::stable_sort(FoundDecls.begin(), FoundDecls.end(),
                 [](NamedDecl *A, NamedDecl *B) {
                   return isa<TypeDecl>(A->getUnderlyingDecl()) >
                          isa<TypeDecl>(B->getUnderlyingDecl());
                 });

// Suggest a fixit to properly name the destroyed type.
auto MakeFixItHint = [&]{
  const CXXRecordDecl *Destroyed = nullptr;
  // FIXME: If we have a scope specifier, suggest its last component?
  if (!SearchType.isNull())
    Destroyed = SearchType->getAsCXXRecordDecl();
  else if (S)
    Destroyed = dyn_cast_or_null<CXXRecordDecl>(S->getEntity());
  if (Destroyed)
    return FixItHint::CreateReplacement(SourceRange(NameLoc),
                                        Destroyed->getNameAsString());
  return FixItHint();
};

if (FoundDecls.empty()) {
  // FIXME: Attempt typo-correction?
  Diag(NameLoc, diag::err_undeclared_destructor_name)
    << &II << MakeFixItHint();
} else if (!SearchType.isNull() && FoundDecls.size() == 1) {
  if (auto *TD = dyn_cast<TypeDecl>(FoundDecls[0]->getUnderlyingDecl())) {
    assert(!SearchType.isNull() &&((void)0)
           "should only reject a type result if we have a search type")((void)0);
    QualType T = Context.getTypeDeclType(TD);
    Diag(NameLoc, diag::err_destructor_expr_type_mismatch)
        << T << SearchType << MakeFixItHint();
  } else {
    Diag(NameLoc, diag::err_destructor_expr_nontype)
        << &II << MakeFixItHint();
  }
} else {
  Diag(NameLoc, SearchType.isNull() ? diag::err_destructor_name_nontype
                                    : diag::err_destructor_expr_mismatch)
      << &II << SearchType << MakeFixItHint();
}

for (NamedDecl *FoundD : FoundDecls) {
  if (auto *TD = dyn_cast<TypeDecl>(FoundD->getUnderlyingDecl()))
    Diag(FoundD->getLocation(), diag::note_destructor_type_here)
        << Context.getTypeDeclType(TD);
  else
    Diag(FoundD->getLocation(), diag::note_destructor_nontype_here)
        << FoundD;
}

return nullptr;
457}

459ParsedType Sema::getDestructorTypeForDecltype(const DeclSpec &DS,
                                            ParsedType ObjectType) {
if (DS.getTypeSpecType() == DeclSpec::TST_error)
  return nullptr;

if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
  return nullptr;
}

assert(DS.getTypeSpecType() == DeclSpec::TST_decltype &&((void)0)
       "unexpected type in getDestructorType")((void)0);
QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());

// If we know the type of the object, check that the correct destructor
// type was named now; we can give better diagnostics this way.
QualType SearchType = GetTypeFromParser(ObjectType);
if (!SearchType.isNull() && !SearchType->isDependentType() &&
    !Context.hasSameUnqualifiedType(T, SearchType)) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_destructor_expr_type_mismatch)
    << T << SearchType;
  return nullptr;
}

return ParsedType::make(T);
484}

486bool Sema::checkLiteralOperatorId(const CXXScopeSpec &SS,
                                const UnqualifiedId &Name, bool IsUDSuffix) {
assert(Name.getKind() == UnqualifiedIdKind::IK_LiteralOperatorId)((void)0);
if (!IsUDSuffix) {
  // [over.literal] p8
  //
  // double operator""_Bq(long double);  // OK: not a reserved identifier
  // double operator"" _Bq(long double); // ill-formed, no diagnostic required
  IdentifierInfo *II = Name.Identifier;
  ReservedIdentifierStatus Status = II->isReserved(PP.getLangOpts());
  SourceLocation Loc = Name.getEndLoc();
  if (Status != ReservedIdentifierStatus::NotReserved &&
      !PP.getSourceManager().isInSystemHeader(Loc)) {
    Diag(Loc, diag::warn_reserved_extern_symbol)
        << II << static_cast<int>(Status)
        << FixItHint::CreateReplacement(
               Name.getSourceRange(),
               (StringRef("operator\"\"") + II->getName()).str());
  }
}

if (!SS.isValid())
  return false;

switch (SS.getScopeRep()->getKind()) {
case NestedNameSpecifier::Identifier:
case NestedNameSpecifier::TypeSpec:
case NestedNameSpecifier::TypeSpecWithTemplate:
  // Per C++11 [over.literal]p2, literal operators can only be declared at
  // namespace scope. Therefore, this unqualified-id cannot name anything.
  // Reject it early, because we have no AST representation for this in the
  // case where the scope is dependent.
  Diag(Name.getBeginLoc(), diag::err_literal_operator_id_outside_namespace)
      << SS.getScopeRep();
  return true;

case NestedNameSpecifier::Global:
case NestedNameSpecifier::Super:
case NestedNameSpecifier::Namespace:
case NestedNameSpecifier::NamespaceAlias:
  return false;
}

llvm_unreachable("unknown nested name specifier kind")__builtin_unreachable();
530}

532/// Build a C++ typeid expression with a type operand.
533ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                              SourceLocation TypeidLoc,
                              TypeSourceInfo *Operand,
                              SourceLocation RParenLoc) {
// C++ [expr.typeid]p4:
//   The top-level cv-qualifiers of the lvalue expression or the type-id
//   that is the operand of typeid are always ignored.
//   If the type of the type-id is a class type or a reference to a class
//   type, the class shall be completely-defined.
Qualifiers Quals;
QualType T
  = Context.getUnqualifiedArrayType(Operand->getType().getNonReferenceType(),
                                    Quals);
if (T->getAs<RecordType>() &&
    RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
  return ExprError();

if (T->isVariablyModifiedType())
  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid) << T);

if (CheckQualifiedFunctionForTypeId(T, TypeidLoc))
  return ExprError();

return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), Operand,
                                   SourceRange(TypeidLoc, RParenLoc));
558}

560/// Build a C++ typeid expression with an expression operand.
561ExprResult Sema::BuildCXXTypeId(QualType TypeInfoType,
                              SourceLocation TypeidLoc,
                              Expr *E,
                              SourceLocation RParenLoc) {
bool WasEvaluated = false;
if (E && !E->isTypeDependent()) {
  if (E->getType()->isPlaceholderType()) {
    ExprResult result = CheckPlaceholderExpr(E);
    if (result.isInvalid()) return ExprError();
    E = result.get();
  }

  QualType T = E->getType();
  if (const RecordType *RecordT = T->getAs<RecordType>()) {
    CXXRecordDecl *RecordD = cast<CXXRecordDecl>(RecordT->getDecl());
    // C++ [expr.typeid]p3:
    //   [...] If the type of the expression is a class type, the class
    //   shall be completely-defined.
    if (RequireCompleteType(TypeidLoc, T, diag::err_incomplete_typeid))
      return ExprError();

    // C++ [expr.typeid]p3:
    //   When typeid is applied to an expression other than an glvalue of a
    //   polymorphic class type [...] [the] expression is an unevaluated
    //   operand. [...]
    if (RecordD->isPolymorphic() && E->isGLValue()) {
      if (isUnevaluatedContext()) {
        // The operand was processed in unevaluated context, switch the
        // context and recheck the subexpression.
        ExprResult Result = TransformToPotentiallyEvaluated(E);
        if (Result.isInvalid())
          return ExprError();
        E = Result.get();
      }

      // We require a vtable to query the type at run time.
      MarkVTableUsed(TypeidLoc, RecordD);
      WasEvaluated = true;
    }
  }

  ExprResult Result = CheckUnevaluatedOperand(E);
  if (Result.isInvalid())
    return ExprError();
  E = Result.get();

  // C++ [expr.typeid]p4:
  //   [...] If the type of the type-id is a reference to a possibly
  //   cv-qualified type, the result of the typeid expression refers to a
  //   std::type_info object representing the cv-unqualified referenced
  //   type.
  Qualifiers Quals;
  QualType UnqualT = Context.getUnqualifiedArrayType(T, Quals);
  if (!Context.hasSameType(T, UnqualT)) {
    T = UnqualT;
    E = ImpCastExprToType(E, UnqualT, CK_NoOp, E->getValueKind()).get();
  }
}

if (E->getType()->isVariablyModifiedType())
  return ExprError(Diag(TypeidLoc, diag::err_variably_modified_typeid)
                   << E->getType());
else if (!inTemplateInstantiation() &&
         E->HasSideEffects(Context, WasEvaluated)) {
  // The expression operand for typeid is in an unevaluated expression
  // context, so side effects could result in unintended consequences.
  Diag(E->getExprLoc(), WasEvaluated
                            ? diag::warn_side_effects_typeid
                            : diag::warn_side_effects_unevaluated_context);
}

return new (Context) CXXTypeidExpr(TypeInfoType.withConst(), E,
                                   SourceRange(TypeidLoc, RParenLoc));
634}

636/// ActOnCXXTypeidOfType - Parse typeid( type-id ) or typeid (expression);
637ExprResult
638Sema::ActOnCXXTypeid(SourceLocation OpLoc, SourceLocation LParenLoc,
                   bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
// typeid is not supported in OpenCL.
if (getLangOpts().OpenCLCPlusPlus) {
  return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported)
                   << "typeid");
}

// Find the std::type_info type.
if (!getStdNamespace())
  return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));

if (!CXXTypeInfoDecl) {
  IdentifierInfo *TypeInfoII = &PP.getIdentifierTable().get("type_info");
  LookupResult R(*this, TypeInfoII, SourceLocation(), LookupTagName);
  LookupQualifiedName(R, getStdNamespace());
  CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
  // Microsoft's typeinfo doesn't have type_info in std but in the global
  // namespace if _HAS_EXCEPTIONS is defined to 0. See PR13153.
  if (!CXXTypeInfoDecl && LangOpts.MSVCCompat) {
    LookupQualifiedName(R, Context.getTranslationUnitDecl());
    CXXTypeInfoDecl = R.getAsSingle<RecordDecl>();
  }
  if (!CXXTypeInfoDecl)
    return ExprError(Diag(OpLoc, diag::err_need_header_before_typeid));
}

if (!getLangOpts().RTTI) {
  return ExprError(Diag(OpLoc, diag::err_no_typeid_with_fno_rtti));
}

QualType TypeInfoType = Context.getTypeDeclType(CXXTypeInfoDecl);

if (isType) {
  // The operand is a type; handle it as such.
  TypeSourceInfo *TInfo = nullptr;
  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                 &TInfo);
  if (T.isNull())
    return ExprError();

  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

  return BuildCXXTypeId(TypeInfoType, OpLoc, TInfo, RParenLoc);
}

// The operand is an expression.
ExprResult Result =
    BuildCXXTypeId(TypeInfoType, OpLoc, (Expr *)TyOrExpr, RParenLoc);

if (!getLangOpts().RTTIData && !Result.isInvalid())
  if (auto *CTE = dyn_cast<CXXTypeidExpr>(Result.get()))
    if (CTE->isPotentiallyEvaluated() && !CTE->isMostDerived(Context))
      Diag(OpLoc, diag::warn_no_typeid_with_rtti_disabled)
          << (getDiagnostics().getDiagnosticOptions().getFormat() ==
              DiagnosticOptions::MSVC);
return Result;
696}

698/// Grabs __declspec(uuid()) off a type, or returns 0 if we cannot resolve to
699/// a single GUID.
700static void
701getUuidAttrOfType(Sema &SemaRef, QualType QT,
                llvm::SmallSetVector<const UuidAttr *, 1> &UuidAttrs) {
// Optionally remove one level of pointer, reference or array indirection.
const Type *Ty = QT.getTypePtr();
if (QT->isPointerType() || QT->isReferenceType())
  Ty = QT->getPointeeType().getTypePtr();
else if (QT->isArrayType())
  Ty = Ty->getBaseElementTypeUnsafe();

const auto *TD = Ty->getAsTagDecl();
if (!TD)
  return;

if (const auto *Uuid = TD->getMostRecentDecl()->getAttr<UuidAttr>()) {
  UuidAttrs.insert(Uuid);
  return;
}

// __uuidof can grab UUIDs from template arguments.
if (const auto *CTSD = dyn_cast<ClassTemplateSpecializationDecl>(TD)) {
  const TemplateArgumentList &TAL = CTSD->getTemplateArgs();
  for (const TemplateArgument &TA : TAL.asArray()) {
    const UuidAttr *UuidForTA = nullptr;
    if (TA.getKind() == TemplateArgument::Type)
      getUuidAttrOfType(SemaRef, TA.getAsType(), UuidAttrs);
    else if (TA.getKind() == TemplateArgument::Declaration)
      getUuidAttrOfType(SemaRef, TA.getAsDecl()->getType(), UuidAttrs);

    if (UuidForTA)
      UuidAttrs.insert(UuidForTA);
  }
}
733}

735/// Build a Microsoft __uuidof expression with a type operand.
736ExprResult Sema::BuildCXXUuidof(QualType Type,
                              SourceLocation TypeidLoc,
                              TypeSourceInfo *Operand,
                              SourceLocation RParenLoc) {
MSGuidDecl *Guid = nullptr;
if (!Operand->getType()->isDependentType()) {
  llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
  getUuidAttrOfType(*this, Operand->getType(), UuidAttrs);
  if (UuidAttrs.empty())
    return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
  if (UuidAttrs.size() > 1)
    return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
  Guid = UuidAttrs.back()->getGuidDecl();
}

return new (Context)
    CXXUuidofExpr(Type, Operand, Guid, SourceRange(TypeidLoc, RParenLoc));
753}

755/// Build a Microsoft __uuidof expression with an expression operand.
756ExprResult Sema::BuildCXXUuidof(QualType Type, SourceLocation TypeidLoc,
                              Expr *E, SourceLocation RParenLoc) {
MSGuidDecl *Guid = nullptr;
if (!E->getType()->isDependentType()) {
  if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
    // A null pointer results in {00000000-0000-0000-0000-000000000000}.
    Guid = Context.getMSGuidDecl(MSGuidDecl::Parts{});
  } else {
    llvm::SmallSetVector<const UuidAttr *, 1> UuidAttrs;
    getUuidAttrOfType(*this, E->getType(), UuidAttrs);
    if (UuidAttrs.empty())
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_without_guid));
    if (UuidAttrs.size() > 1)
      return ExprError(Diag(TypeidLoc, diag::err_uuidof_with_multiple_guids));
    Guid = UuidAttrs.back()->getGuidDecl();
  }
}

return new (Context)
    CXXUuidofExpr(Type, E, Guid, SourceRange(TypeidLoc, RParenLoc));
776}

778/// ActOnCXXUuidof - Parse __uuidof( type-id ) or __uuidof (expression);
779ExprResult
780Sema::ActOnCXXUuidof(SourceLocation OpLoc, SourceLocation LParenLoc,
                   bool isType, void *TyOrExpr, SourceLocation RParenLoc) {
QualType GuidType = Context.getMSGuidType();
GuidType.addConst();

if (isType) {
  // The operand is a type; handle it as such.
  TypeSourceInfo *TInfo = nullptr;
  QualType T = GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrExpr),
                                 &TInfo);
  if (T.isNull())
    return ExprError();

  if (!TInfo)
    TInfo = Context.getTrivialTypeSourceInfo(T, OpLoc);

  return BuildCXXUuidof(GuidType, OpLoc, TInfo, RParenLoc);
}

// The operand is an expression.
return BuildCXXUuidof(GuidType, OpLoc, (Expr*)TyOrExpr, RParenLoc);
801}

803/// ActOnCXXBoolLiteral - Parse {true,false} literals.
804ExprResult
805Sema::ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind) {
assert((Kind == tok::kw_true || Kind == tok::kw_false) &&((void)0)
       "Unknown C++ Boolean value!")((void)0);
return new (Context)
    CXXBoolLiteralExpr(Kind == tok::kw_true, Context.BoolTy, OpLoc);
810}

812/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
813ExprResult
814Sema::ActOnCXXNullPtrLiteral(SourceLocation Loc) {
return new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
816}

818/// ActOnCXXThrow - Parse throw expressions.
819ExprResult
820Sema::ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *Ex) {
bool IsThrownVarInScope = false;
if (Ex) {
  // C++0x [class.copymove]p31:
  //   When certain criteria are met, an implementation is allowed to omit the
  //   copy/move construction of a class object [...]
  //
  //     - in a throw-expression, when the operand is the name of a
  //       non-volatile automatic object (other than a function or catch-
  //       clause parameter) whose scope does not extend beyond the end of the
  //       innermost enclosing try-block (if there is one), the copy/move
  //       operation from the operand to the exception object (15.1) can be
  //       omitted by constructing the automatic object directly into the
  //       exception object
  if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Ex->IgnoreParens()))
    if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
      if (Var->hasLocalStorage() && !Var->getType().isVolatileQualified()) {
        for( ; S; S = S->getParent()) {
          if (S->isDeclScope(Var)) {
            IsThrownVarInScope = true;
            break;
          }

          if (S->getFlags() &
              (Scope::FnScope | Scope::ClassScope | Scope::BlockScope |
               Scope::FunctionPrototypeScope | Scope::ObjCMethodScope |
               Scope::TryScope))
            break;
        }
      }
    }
}

return BuildCXXThrow(OpLoc, Ex, IsThrownVarInScope);
854}

856ExprResult Sema::BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                             bool IsThrownVarInScope) {
// Don't report an error if 'throw' is used in system headers.
if (!getLangOpts().CXXExceptions &&
    !getSourceManager().isInSystemHeader(OpLoc) && !getLangOpts().CUDA) {
  // Delay error emission for the OpenMP device code.
  targetDiag(OpLoc, diag::err_exceptions_disabled) << "throw";
}

// Exceptions aren't allowed in CUDA device code.
if (getLangOpts().CUDA)
  CUDADiagIfDeviceCode(OpLoc, diag::err_cuda_device_exceptions)
      << "throw" << CurrentCUDATarget();

if (getCurScope() && getCurScope()->isOpenMPSimdDirectiveScope())
  Diag(OpLoc, diag::err_omp_simd_region_cannot_use_stmt) << "throw";

if (Ex && !Ex->isTypeDependent()) {
  // Initialize the exception result.  This implicitly weeds out
  // abstract types or types with inaccessible copy constructors.

  // C++0x [class.copymove]p31:
  //   When certain criteria are met, an implementation is allowed to omit the
  //   copy/move construction of a class object [...]
  //
  //     - in a throw-expression, when the operand is the name of a
  //       non-volatile automatic object (other than a function or
  //       catch-clause
  //       parameter) whose scope does not extend beyond the end of the
  //       innermost enclosing try-block (if there is one), the copy/move
  //       operation from the operand to the exception object (15.1) can be
  //       omitted by constructing the automatic object directly into the
  //       exception object
  NamedReturnInfo NRInfo =
      IsThrownVarInScope ? getNamedReturnInfo(Ex) : NamedReturnInfo();

  QualType ExceptionObjectTy = Context.getExceptionObjectType(Ex->getType());
  if (CheckCXXThrowOperand(OpLoc, ExceptionObjectTy, Ex))
    return ExprError();

  InitializedEntity Entity =
      InitializedEntity::InitializeException(OpLoc, ExceptionObjectTy);
  ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRInfo, Ex);
  if (Res.isInvalid())
    return ExprError();
  Ex = Res.get();
}

// PPC MMA non-pointer types are not allowed as throw expr types.
if (Ex && Context.getTargetInfo().getTriple().isPPC64())
  CheckPPCMMAType(Ex->getType(), Ex->getBeginLoc());

return new (Context)
    CXXThrowExpr(Ex, Context.VoidTy, OpLoc, IsThrownVarInScope);
910}

912static void
913collectPublicBases(CXXRecordDecl *RD,
                 llvm::DenseMap<CXXRecordDecl *, unsigned> &SubobjectsSeen,
                 llvm::SmallPtrSetImpl<CXXRecordDecl *> &VBases,
                 llvm::SetVector<CXXRecordDecl *> &PublicSubobjectsSeen,
                 bool ParentIsPublic) {
for (const CXXBaseSpecifier &BS : RD->bases()) {
  CXXRecordDecl *BaseDecl = BS.getType()->getAsCXXRecordDecl();
  bool NewSubobject;
  // Virtual bases constitute the same subobject.  Non-virtual bases are
  // always distinct subobjects.
  if (BS.isVirtual())
    NewSubobject = VBases.insert(BaseDecl).second;
  else
    NewSubobject = true;

  if (NewSubobject)
    ++SubobjectsSeen[BaseDecl];

  // Only add subobjects which have public access throughout the entire chain.
  bool PublicPath = ParentIsPublic && BS.getAccessSpecifier() == AS_public;
  if (PublicPath)
    PublicSubobjectsSeen.insert(BaseDecl);

  // Recurse on to each base subobject.
  collectPublicBases(BaseDecl, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                     PublicPath);
}
940}

942static void getUnambiguousPublicSubobjects(
  CXXRecordDecl *RD, llvm::SmallVectorImpl<CXXRecordDecl *> &Objects) {
llvm::DenseMap<CXXRecordDecl *, unsigned> SubobjectsSeen;
llvm::SmallSet<CXXRecordDecl *, 2> VBases;
llvm::SetVector<CXXRecordDecl *> PublicSubobjectsSeen;
SubobjectsSeen[RD] = 1;
PublicSubobjectsSeen.insert(RD);
collectPublicBases(RD, SubobjectsSeen, VBases, PublicSubobjectsSeen,
                   /*ParentIsPublic=*/true);

for (CXXRecordDecl *PublicSubobject : PublicSubobjectsSeen) {
  // Skip ambiguous objects.
  if (SubobjectsSeen[PublicSubobject] > 1)
    continue;

  Objects.push_back(PublicSubobject);
}
959}

961/// CheckCXXThrowOperand - Validate the operand of a throw.
962bool Sema::CheckCXXThrowOperand(SourceLocation ThrowLoc,
                              QualType ExceptionObjectTy, Expr *E) {
//   If the type of the exception would be an incomplete type or a pointer
//   to an incomplete type other than (cv) void the program is ill-formed.
QualType Ty = ExceptionObjectTy;
bool isPointer = false;
if (const PointerType* Ptr = Ty->getAs<PointerType>()) {
  Ty = Ptr->getPointeeType();
  isPointer = true;
}
if (!isPointer || !Ty->isVoidType()) {
  if (RequireCompleteType(ThrowLoc, Ty,
                          isPointer ? diag::err_throw_incomplete_ptr
                                    : diag::err_throw_incomplete,
                          E->getSourceRange()))
    return true;

  if (!isPointer && Ty->isSizelessType()) {
    Diag(ThrowLoc, diag::err_throw_sizeless) << Ty << E->getSourceRange();
    return true;
  }

  if (RequireNonAbstractType(ThrowLoc, ExceptionObjectTy,
                             diag::err_throw_abstract_type, E))
    return true;
}

// If the exception has class type, we need additional handling.
CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
if (!RD)
  return false;

// If we are throwing a polymorphic class type or pointer thereof,
// exception handling will make use of the vtable.
MarkVTableUsed(ThrowLoc, RD);

// If a pointer is thrown, the referenced object will not be destroyed.
if (isPointer)
  return false;

// If the class has a destructor, we must be able to call it.
if (!RD->hasIrrelevantDestructor()) {
  if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
    MarkFunctionReferenced(E->getExprLoc(), Destructor);
    CheckDestructorAccess(E->getExprLoc(), Destructor,
                          PDiag(diag::err_access_dtor_exception) << Ty);
    if (DiagnoseUseOfDecl(Destructor, E->getExprLoc()))
      return true;
  }
}

// The MSVC ABI creates a list of all types which can catch the exception
// object.  This list also references the appropriate copy constructor to call
// if the object is caught by value and has a non-trivial copy constructor.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  // We are only interested in the public, unambiguous bases contained within
  // the exception object.  Bases which are ambiguous or otherwise
  // inaccessible are not catchable types.
  llvm::SmallVector<CXXRecordDecl *, 2> UnambiguousPublicSubobjects;
  getUnambiguousPublicSubobjects(RD, UnambiguousPublicSubobjects);

  for (CXXRecordDecl *Subobject : UnambiguousPublicSubobjects) {
    // Attempt to lookup the copy constructor.  Various pieces of machinery
    // will spring into action, like template instantiation, which means this
    // cannot be a simple walk of the class's decls.  Instead, we must perform
    // lookup and overload resolution.
    CXXConstructorDecl *CD = LookupCopyingConstructor(Subobject, 0);
    if (!CD || CD->isDeleted())
      continue;

    // Mark the constructor referenced as it is used by this throw expression.
    MarkFunctionReferenced(E->getExprLoc(), CD);

    // Skip this copy constructor if it is trivial, we don't need to record it
    // in the catchable type data.
    if (CD->isTrivial())
      continue;

    // The copy constructor is non-trivial, create a mapping from this class
    // type to this constructor.
    // N.B.  The selection of copy constructor is not sensitive to this
    // particular throw-site.  Lookup will be performed at the catch-site to
    // ensure that the copy constructor is, in fact, accessible (via
    // friendship or any other means).
    Context.addCopyConstructorForExceptionObject(Subobject, CD);

    // We don't keep the instantiated default argument expressions around so
    // we must rebuild them here.
    for (unsigned I = 1, E = CD->getNumParams(); I != E; ++I) {
      if (CheckCXXDefaultArgExpr(ThrowLoc, CD, CD->getParamDecl(I)))
        return true;
    }
  }
}

// Under the Itanium C++ ABI, memory for the exception object is allocated by
// the runtime with no ability for the compiler to request additional
// alignment. Warn if the exception type requires alignment beyond the minimum
// guaranteed by the target C++ runtime.
if (Context.getTargetInfo().getCXXABI().isItaniumFamily()) {
  CharUnits TypeAlign = Context.getTypeAlignInChars(Ty);
  CharUnits ExnObjAlign = Context.getExnObjectAlignment();
  if (ExnObjAlign < TypeAlign) {
    Diag(ThrowLoc, diag::warn_throw_underaligned_obj);
    Diag(ThrowLoc, diag::note_throw_underaligned_obj)
        << Ty << (unsigned)TypeAlign.getQuantity()
        << (unsigned)ExnObjAlign.getQuantity();
  }
}

return false;
1073}

1075static QualType adjustCVQualifiersForCXXThisWithinLambda(
  ArrayRef<FunctionScopeInfo *> FunctionScopes, QualType ThisTy,
  DeclContext *CurSemaContext, ASTContext &ASTCtx) {

QualType ClassType = ThisTy->getPointeeType();
LambdaScopeInfo *CurLSI = nullptr;
DeclContext *CurDC = CurSemaContext;

// Iterate through the stack of lambdas starting from the innermost lambda to
// the outermost lambda, checking if '*this' is ever captured by copy - since
// that could change the cv-qualifiers of the '*this' object.
// The object referred to by '*this' starts out with the cv-qualifiers of its
// member function.  We then start with the innermost lambda and iterate
// outward checking to see if any lambda performs a by-copy capture of '*this'
// - and if so, any nested lambda must respect the 'constness' of that
// capturing lamdbda's call operator.
//

// Since the FunctionScopeInfo stack is representative of the lexical
// nesting of the lambda expressions during initial parsing (and is the best
// place for querying information about captures about lambdas that are
// partially processed) and perhaps during instantiation of function templates
// that contain lambda expressions that need to be transformed BUT not
// necessarily during instantiation of a nested generic lambda's function call
// operator (which might even be instantiated at the end of the TU) - at which
// time the DeclContext tree is mature enough to query capture information
// reliably - we use a two pronged approach to walk through all the lexically
// enclosing lambda expressions:
//
//  1) Climb down the FunctionScopeInfo stack as long as each item represents
//  a Lambda (i.e. LambdaScopeInfo) AND each LSI's 'closure-type' is lexically
//  enclosed by the call-operator of the LSI below it on the stack (while
//  tracking the enclosing DC for step 2 if needed).  Note the topmost LSI on
//  the stack represents the innermost lambda.
//
//  2) If we run out of enclosing LSI's, check if the enclosing DeclContext
//  represents a lambda's call operator.  If it does, we must be instantiating
//  a generic lambda's call operator (represented by the Current LSI, and
//  should be the only scenario where an inconsistency between the LSI and the
//  DeclContext should occur), so climb out the DeclContexts if they
//  represent lambdas, while querying the corresponding closure types
//  regarding capture information.

// 1) Climb down the function scope info stack.
for (int I = FunctionScopes.size();
     I-- && isa<LambdaScopeInfo>(FunctionScopes[I]) &&
     (!CurLSI || !CurLSI->Lambda || CurLSI->Lambda->getDeclContext() ==
                     cast<LambdaScopeInfo>(FunctionScopes[I])->CallOperator);
     CurDC = getLambdaAwareParentOfDeclContext(CurDC)) {
  CurLSI = cast<LambdaScopeInfo>(FunctionScopes[I]);

  if (!CurLSI->isCXXThisCaptured())
      continue;

  auto C = CurLSI->getCXXThisCapture();

  if (C.isCopyCapture()) {
    ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
    if (CurLSI->CallOperator->isConst())
      ClassType.addConst();
    return ASTCtx.getPointerType(ClassType);
  }
}

// 2) We've run out of ScopeInfos but check if CurDC is a lambda (which can
// happen during instantiation of its nested generic lambda call operator)
if (isLambdaCallOperator(CurDC)) {
  assert(CurLSI && "While computing 'this' capture-type for a generic "((void)0)
                   "lambda, we must have a corresponding LambdaScopeInfo")((void)0);
  assert(isGenericLambdaCallOperatorSpecialization(CurLSI->CallOperator) &&((void)0)
         "While computing 'this' capture-type for a generic lambda, when we "((void)0)
         "run out of enclosing LSI's, yet the enclosing DC is a "((void)0)
         "lambda-call-operator we must be (i.e. Current LSI) in a generic "((void)0)
         "lambda call oeprator")((void)0);
  assert(CurDC == getLambdaAwareParentOfDeclContext(CurLSI->CallOperator))((void)0);

  auto IsThisCaptured =
      [](CXXRecordDecl *Closure, bool &IsByCopy, bool &IsConst) {
    IsConst = false;
    IsByCopy = false;
    for (auto &&C : Closure->captures()) {
      if (C.capturesThis()) {
        if (C.getCaptureKind() == LCK_StarThis)
          IsByCopy = true;
        if (Closure->getLambdaCallOperator()->isConst())
          IsConst = true;
        return true;
      }
    }
    return false;
  };

  bool IsByCopyCapture = false;
  bool IsConstCapture = false;
  CXXRecordDecl *Closure = cast<CXXRecordDecl>(CurDC->getParent());
  while (Closure &&
         IsThisCaptured(Closure, IsByCopyCapture, IsConstCapture)) {
    if (IsByCopyCapture) {
      ClassType.removeLocalCVRQualifiers(Qualifiers::CVRMask);
      if (IsConstCapture)
        ClassType.addConst();
      return ASTCtx.getPointerType(ClassType);
    }
    Closure = isLambdaCallOperator(Closure->getParent())
                  ? cast<CXXRecordDecl>(Closure->getParent()->getParent())
                  : nullptr;
  }
}
return ASTCtx.getPointerType(ClassType);
1184}

1186QualType Sema::getCurrentThisType() {
DeclContext *DC = getFunctionLevelDeclContext();
QualType ThisTy = CXXThisTypeOverride;

if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(DC)) {
  if (method && method->isInstance())
    ThisTy = method->getThisType();
}

if (ThisTy.isNull() && isLambdaCallOperator(CurContext) &&
    inTemplateInstantiation() && isa<CXXRecordDecl>(DC)) {

  // This is a lambda call operator that is being instantiated as a default
  // initializer. DC must point to the enclosing class type, so we can recover
  // the 'this' type from it.
  QualType ClassTy = Context.getTypeDeclType(cast<CXXRecordDecl>(DC));
  // There are no cv-qualifiers for 'this' within default initializers,
  // per [expr.prim.general]p4.
  ThisTy = Context.getPointerType(ClassTy);
}

// If we are within a lambda's call operator, the cv-qualifiers of 'this'
// might need to be adjusted if the lambda or any of its enclosing lambda's
// captures '*this' by copy.
if (!ThisTy.isNull() && isLambdaCallOperator(CurContext))
  return adjustCVQualifiersForCXXThisWithinLambda(FunctionScopes, ThisTy,
                                                  CurContext, Context);
return ThisTy;
1214}

1216Sema::CXXThisScopeRAII::CXXThisScopeRAII(Sema &S,
                                       Decl *ContextDecl,
                                       Qualifiers CXXThisTypeQuals,
                                       bool Enabled)
: S(S), OldCXXThisTypeOverride(S.CXXThisTypeOverride), Enabled(false)
1221{
if (!Enabled || !ContextDecl)
  return;

CXXRecordDecl *Record = nullptr;
if (ClassTemplateDecl *Template = dyn_cast<ClassTemplateDecl>(ContextDecl))
  Record = Template->getTemplatedDecl();
else
  Record = cast<CXXRecordDecl>(ContextDecl);

QualType T = S.Context.getRecordType(Record);
T = S.getASTContext().getQualifiedType(T, CXXThisTypeQuals);

S.CXXThisTypeOverride = S.Context.getPointerType(T);

this->Enabled = true;
1237}


1240Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
if (Enabled) {
  S.CXXThisTypeOverride = OldCXXThisTypeOverride;
}
1244}

1246static void buildLambdaThisCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI) {
SourceLocation DiagLoc = LSI->IntroducerRange.getEnd();
30
←
Called C++ object pointer is null
assert(!LSI->isCXXThisCaptured())((void)0);
//  [=, this] {};   // until C++20: Error: this when = is the default
if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval &&
    !Sema.getLangOpts().CPlusPlus20)
  return;
Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit)
    << FixItHint::CreateInsertion(
           DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "this");
1256}

1258bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
  bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
  const bool ByCopy) {
// We don't need to capture this in an unevaluated context.
if (isUnevaluatedContext() && !Explicit)
5
←
Calling 'Sema::isUnevaluatedContext'→
13
←
Returning from 'Sema::isUnevaluatedContext'→
  return true;

assert((!ByCopy || Explicit) && "cannot implicitly capture *this by value")((void)0);

const int MaxFunctionScopesIndex = FunctionScopeIndexToStopAt13.1
'FunctionScopeIndexToStopAt' is null

13.1	'FunctionScopeIndexToStopAt' is null

←

'?' condition is false

→

1268 ? *FunctionScopeIndexToStopAt 1269 : FunctionScopes.size() - 1; 1270 1271 // Check that we can capture the *enclosing object* (referred to by '*this') 1272 // by the capturing-entity/closure (lambda/block/etc) at 1273 // MaxFunctionScopesIndex-deep on the FunctionScopes stack. 1274 1275 // Note: The *enclosing object* can only be captured by-value by a 1276 // closure that is a lambda, using the explicit notation: 1277 // [*this] { ... }. 1278 // Every other capture of the *enclosing object* results in its by-reference 1279 // capture. 1280 1281 // For a closure 'L' (at MaxFunctionScopesIndex in the FunctionScopes 1282 // stack), we can capture the *enclosing object* only if: 1283 // - 'L' has an explicit byref or byval capture of the *enclosing object* 1284 // - or, 'L' has an implicit capture. 1285 // AND 1286 // -- there is no enclosing closure 1287 // -- or, there is some enclosing closure 'E' that has already captured the 1288 // *enclosing object*, and every intervening closure (if any) between 'E' 1289 // and 'L' can implicitly capture the *enclosing object*. 1290 // -- or, every enclosing closure can implicitly capture the 1291 // *enclosing object* 1292 1293 1294 unsigned NumCapturingClosures = 0; 1295 for (int idx = MaxFunctionScopesIndex; idx

14.1	'idx' is >= 0

14.1	'idx' is >= 0

>= 0; idx--) {

←

Loop condition is true. Entering loop body

→

1296 if (CapturingScopeInfo *CSI

16.1	'CSI' is non-null

16.1	'CSI' is non-null

←

Taking true branch

→

1297 dyn_cast<CapturingScopeInfo>(FunctionScopes[idx])) {

←

Assuming the object is a 'CapturingScopeInfo'

→

1298 if (CSI->CXXThisCaptureIndex != 0) {

←

Assuming field 'CXXThisCaptureIndex' is equal to 0

→

←

Taking false branch

→

1299 // 'this' is already being captured; there isn't anything more to do. 1300 CSI->Captures[CSI->CXXThisCaptureIndex - 1].markUsed(BuildAndDiagnose); 1301 break; 1302 } 1303 LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);

←

Assuming 'CSI' is not a 'LambdaScopeInfo'

→

←

'LSI' initialized to a null pointer value

→

1304 if (LSI

21.1	'LSI' is null

21.1	'LSI' is null

&& isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) { 1305 // This context can't implicitly capture 'this'; fail out. 1306 if (BuildAndDiagnose) { 1307 Diag(Loc, diag::err_this_capture) 1308 << (Explicit && idx == MaxFunctionScopesIndex); 1309 if (!Explicit) 1310 buildLambdaThisCaptureFixit(*this, LSI); 1311 } 1312 return true; 1313 } 1314 if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||

←

Assuming field 'ImpCaptureStyle' is not equal to ImpCap_LambdaByref

→

1315 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval ||

←

Assuming field 'ImpCaptureStyle' is not equal to ImpCap_LambdaByval

→

1316 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_Block ||

←

Assuming field 'ImpCaptureStyle' is not equal to ImpCap_Block

→

1317 CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_CapturedRegion ||

←

Assuming field 'ImpCaptureStyle' is not equal to ImpCap_CapturedRegion

→

1318 (Explicit

25.1	'Explicit' is false

25.1	'Explicit' is false

&& idx == MaxFunctionScopesIndex)) { 1319 // Regarding (Explicit && idx == MaxFunctionScopesIndex): only the first 1320 // iteration through can be an explicit capture, all enclosing closures, 1321 // if any, must perform implicit captures. 1322 1323 // This closure can capture 'this'; continue looking upwards. 1324 NumCapturingClosures++; 1325 continue; 1326 } 1327 // This context can't implicitly capture 'this'; fail out. 1328 if (BuildAndDiagnose

25.2	'BuildAndDiagnose' is true

25.2	'BuildAndDiagnose' is true

)

←

Taking true branch

→

1329 Diag(Loc, diag::err_this_capture) 1330 << (Explicit

26.1	'Explicit' is false

26.1	'Explicit' is false

&& idx == MaxFunctionScopesIndex); 1331 1332 if (!Explicit

26.2	'Explicit' is false

26.2	'Explicit' is false

)

←

Taking true branch

→

1333 buildLambdaThisCaptureFixit(*this, LSI);

←

Passing null pointer value via 2nd parameter 'LSI'

→

←

Calling 'buildLambdaThisCaptureFixit'

→

1334 return true; 1335 } 1336 break; 1337 } 1338 if (!BuildAndDiagnose) return false; 1339 1340 // If we got here, then the closure at MaxFunctionScopesIndex on the 1341 // FunctionScopes stack, can capture the *enclosing object*, so capture it 1342 // (including implicit by-reference captures in any enclosing closures). 1343 1344 // In the loop below, respect the ByCopy flag only for the closure requesting 1345 // the capture (i.e. first iteration through the loop below). Ignore it for 1346 // all enclosing closure's up to NumCapturingClosures (since they must be 1347 // implicitly capturing the *enclosing object* by reference (see loop 1348 // above)). 1349 assert((!ByCopy ||((void)0) 1350 dyn_cast<LambdaScopeInfo>(FunctionScopes[MaxFunctionScopesIndex])) &&((void)0) 1351 "Only a lambda can capture the enclosing object (referred to by "((void)0) 1352 "*this) by copy")((void)0); 1353 QualType ThisTy = getCurrentThisType(); 1354 for (int idx = MaxFunctionScopesIndex; NumCapturingClosures; 1355 --idx, --NumCapturingClosures) { 1356 CapturingScopeInfo *CSI = cast<CapturingScopeInfo>(FunctionScopes[idx]); 1357 1358 // The type of the corresponding data member (not a 'this' pointer if 'by 1359 // copy'). 1360 QualType CaptureType = ThisTy; 1361 if (ByCopy) { 1362 // If we are capturing the object referred to by '*this' by copy, ignore 1363 // any cv qualifiers inherited from the type of the member function for 1364 // the type of the closure-type's corresponding data member and any use 1365 // of 'this'. 1366 CaptureType = ThisTy->getPointeeType(); 1367 CaptureType.removeLocalCVRQualifiers(Qualifiers::CVRMask); 1368 } 1369 1370 bool isNested = NumCapturingClosures > 1; 1371 CSI->addThisCapture(isNested, Loc, CaptureType, ByCopy); 1372 } 1373 return false; 1374} 1375 1376ExprResult Sema::ActOnCXXThis(SourceLocation Loc) { 1377 /// C++ 9.3.2: In the body of a non-static member function, the keyword this 1378 /// is a non-lvalue expression whose value is the address of the object for 1379 /// which the function is called. 1380 1381 QualType ThisTy = getCurrentThisType(); 1382 if (ThisTy.isNull())

Taking false branch

→

1383 return Diag(Loc, diag::err_invalid_this_use); 1384 return BuildCXXThisExpr(Loc, ThisTy, /*IsImplicit=*/false);

←

Calling 'Sema::BuildCXXThisExpr'

→

1385} 1386 1387Expr *Sema::BuildCXXThisExpr(SourceLocation Loc, QualType Type, 1388 bool IsImplicit) { 1389 auto *This = new (Context) CXXThisExpr(Loc, Type, IsImplicit); 1390 MarkThisReferenced(This);

←

Calling 'Sema::MarkThisReferenced'

→

1391 return This; 1392} 1393 1394void Sema::MarkThisReferenced(CXXThisExpr *This) { 1395 CheckCXXThisCapture(This->getExprLoc());

←

Calling 'Sema::CheckCXXThisCapture'

→

1396} 1397 1398bool Sema::isThisOutsideMemberFunctionBody(QualType BaseType) { 1399 // If we're outside the body of a member function, then we'll have a specified 1400 // type for 'this'. 1401 if (CXXThisTypeOverride.isNull()) 1402 return false; 1403 1404 // Determine whether we're looking into a class that's currently being 1405 // defined. 1406 CXXRecordDecl *Class = BaseType->getAsCXXRecordDecl(); 1407 return Class && Class->isBeingDefined(); 1408} 1409 1410/// Parse construction of a specified type. 1411/// Can be interpreted either as function-style casting ("int(x)") 1412/// or class type construction ("ClassType(x,y,z)") 1413/// or creation of a value-initialized type ("int()"). 1414ExprResult 1415Sema::ActOnCXXTypeConstructExpr(ParsedType TypeRep, 1416 SourceLocation LParenOrBraceLoc, 1417 MultiExprArg exprs, 1418 SourceLocation RParenOrBraceLoc, 1419 bool ListInitialization) { 1420 if (!TypeRep) 1421 return ExprError(); 1422 1423 TypeSourceInfo *TInfo; 1424 QualType Ty = GetTypeFromParser(TypeRep, &TInfo); 1425 if (!TInfo) 1426 TInfo = Context.getTrivialTypeSourceInfo(Ty, SourceLocation()); 1427 1428 auto Result = BuildCXXTypeConstructExpr(TInfo, LParenOrBraceLoc, exprs, 1429 RParenOrBraceLoc, ListInitialization); 1430 // Avoid creating a non-type-dependent expression that contains typos. 1431 // Non-type-dependent expressions are liable to be discarded without 1432 // checking for embedded typos. 1433 if (!Result.isInvalid() && Result.get()->isInstantiationDependent() && 1434 !Result.get()->isTypeDependent()) 1435 Result = CorrectDelayedTyposInExpr(Result.get()); 1436 else if (Result.isInvalid()) 1437 Result = CreateRecoveryExpr(TInfo->getTypeLoc().getBeginLoc(), 1438 RParenOrBraceLoc, exprs, Ty); 1439 return Result; 1440} 1441 1442ExprResult 1443Sema::BuildCXXTypeConstructExpr(TypeSourceInfo *TInfo, 1444 SourceLocation LParenOrBraceLoc, 1445 MultiExprArg Exprs, 1446 SourceLocation RParenOrBraceLoc, 1447 bool ListInitialization) { 1448 QualType Ty = TInfo->getType(); 1449 SourceLocation TyBeginLoc = TInfo->getTypeLoc().getBeginLoc(); 1450 1451 assert((!ListInitialization ||((void)0) 1452 (Exprs.size() == 1 && isa<InitListExpr>(Exprs[0]))) &&((void)0) 1453 "List initialization must have initializer list as expression.")((void)0); 1454 SourceRange FullRange = SourceRange(TyBeginLoc, RParenOrBraceLoc); 1455 1456 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TInfo); 1457 InitializationKind Kind = 1458 Exprs.size() 1459 ? ListInitialization 1460 ? InitializationKind::CreateDirectList( 1461 TyBeginLoc, LParenOrBraceLoc, RParenOrBraceLoc) 1462 : InitializationKind::CreateDirect(TyBeginLoc, LParenOrBraceLoc, 1463 RParenOrBraceLoc) 1464 : InitializationKind::CreateValue(TyBeginLoc, LParenOrBraceLoc, 1465 RParenOrBraceLoc); 1466 1467 // C++1z [expr.type.conv]p1: 1468 // If the type is a placeholder for a deduced class type, [...perform class 1469 // template argument deduction...] 1470 DeducedType *Deduced = Ty->getContainedDeducedType(); 1471 if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) { 1472 Ty = DeduceTemplateSpecializationFromInitializer(TInfo, Entity, 1473 Kind, Exprs); 1474 if (Ty.isNull()) 1475 return ExprError(); 1476 Entity = InitializedEntity::InitializeTemporary(TInfo, Ty); 1477 } 1478 1479 if (Ty->isDependentType() || CallExpr::hasAnyTypeDependentArguments(Exprs)) { 1480 // FIXME: CXXUnresolvedConstructExpr does not model list-initialization 1481 // directly. We work around this by dropping the locations of the braces. 1482 SourceRange Locs = ListInitialization 1483 ? SourceRange() 1484 : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); 1485 return CXXUnresolvedConstructExpr::Create(Context, Ty.getNonReferenceType(), 1486 TInfo, Locs.getBegin(), Exprs, 1487 Locs.getEnd()); 1488 } 1489 1490 // C++ [expr.type.conv]p1: 1491 // If the expression list is a parenthesized single expression, the type 1492 // conversion expression is equivalent (in definedness, and if defined in 1493 // meaning) to the corresponding cast expression. 1494 if (Exprs.size() == 1 && !ListInitialization && 1495 !isa<InitListExpr>(Exprs[0])) { 1496 Expr *Arg = Exprs[0]; 1497 return BuildCXXFunctionalCastExpr(TInfo, Ty, LParenOrBraceLoc, Arg, 1498 RParenOrBraceLoc); 1499 } 1500 1501 // For an expression of the form T(), T shall not be an array type. 1502 QualType ElemTy = Ty; 1503 if (Ty->isArrayType()) { 1504 if (!ListInitialization) 1505 return ExprError(Diag(TyBeginLoc, diag::err_value_init_for_array_type) 1506 << FullRange); 1507 ElemTy = Context.getBaseElementType(Ty); 1508 } 1509 1510 // There doesn't seem to be an explicit rule against this but sanity demands 1511 // we only construct objects with object types. 1512 if (Ty->isFunctionType()) 1513 return ExprError(Diag(TyBeginLoc, diag::err_init_for_function_type) 1514 << Ty << FullRange); 1515 1516 // C++17 [expr.type.conv]p2: 1517 // If the type is cv void and the initializer is (), the expression is a 1518 // prvalue of the specified type that performs no initialization. 1519 if (!Ty->isVoidType() && 1520 RequireCompleteType(TyBeginLoc, ElemTy, 1521 diag::err_invalid_incomplete_type_use, FullRange)) 1522 return ExprError(); 1523 1524 // Otherwise, the expression is a prvalue of the specified type whose 1525 // result object is direct-initialized (11.6) with the initializer. 1526 InitializationSequence InitSeq(*this, Entity, Kind, Exprs); 1527 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Exprs); 1528 1529 if (Result.isInvalid()) 1530 return Result; 1531 1532 Expr *Inner = Result.get(); 1533 if (CXXBindTemporaryExpr *BTE = dyn_cast_or_null<CXXBindTemporaryExpr>(Inner)) 1534 Inner = BTE->getSubExpr(); 1535 if (!isa<CXXTemporaryObjectExpr>(Inner) && 1536 !isa<CXXScalarValueInitExpr>(Inner)) { 1537 // If we created a CXXTemporaryObjectExpr, that node also represents the 1538 // functional cast. Otherwise, create an explicit cast to represent 1539 // the syntactic form of a functional-style cast that was used here. 1540 // 1541 // FIXME: Creating a CXXFunctionalCastExpr around a CXXConstructExpr 1542 // would give a more consistent AST representation than using a 1543 // CXXTemporaryObjectExpr. It's also weird that the functional cast 1544 // is sometimes handled by initialization and sometimes not. 1545 QualType ResultType = Result.get()->getType(); 1546 SourceRange Locs = ListInitialization 1547 ? SourceRange() 1548 : SourceRange(LParenOrBraceLoc, RParenOrBraceLoc); 1549 Result = CXXFunctionalCastExpr::Create( 1550 Context, ResultType, Expr::getValueKindForType(Ty), TInfo, CK_NoOp, 1551 Result.get(), /*Path=*/nullptr, CurFPFeatureOverrides(), 1552 Locs.getBegin(), Locs.getEnd()); 1553 } 1554 1555 return Result; 1556} 1557 1558bool Sema::isUsualDeallocationFunction(const CXXMethodDecl *Method) { 1559 // [CUDA] Ignore this function, if we can't call it. 1560 const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext); 1561 if (getLangOpts().CUDA) { 1562 auto CallPreference = IdentifyCUDAPreference(Caller, Method); 1563 // If it's not callable at all, it's not the right function. 1564 if (CallPreference < CFP_WrongSide) 1565 return false; 1566 if (CallPreference == CFP_WrongSide) { 1567 // Maybe. We have to check if there are better alternatives. 1568 DeclContext::lookup_result R = 1569 Method->getDeclContext()->lookup(Method->getDeclName()); 1570 for (const auto *D : R) { 1571 if (const auto *FD = dyn_cast<FunctionDecl>(D)) { 1572 if (IdentifyCUDAPreference(Caller, FD) > CFP_WrongSide) 1573 return false; 1574 } 1575 } 1576 // We've found no better variants. 1577 } 1578 } 1579 1580 SmallVector<const FunctionDecl*, 4> PreventedBy; 1581 bool Result = Method->isUsualDeallocationFunction(PreventedBy); 1582 1583 if (Result || !getLangOpts().CUDA || PreventedBy.empty()) 1584 return Result; 1585 1586 // In case of CUDA, return true if none of the 1-argument deallocator 1587 // functions are actually callable. 1588 return llvm::none_of(PreventedBy, [&](const FunctionDecl *FD) { 1589 assert(FD->getNumParams() == 1 &&((void)0) 1590 "Only single-operand functions should be in PreventedBy")((void)0); 1591 return IdentifyCUDAPreference(Caller, FD) >= CFP_HostDevice; 1592 }); 1593} 1594 1595/// Determine whether the given function is a non-placement 1596/// deallocation function. 1597static bool isNonPlacementDeallocationFunction(Sema &S, FunctionDecl *FD) { 1598 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FD)) 1599 return S.isUsualDeallocationFunction(Method); 1600 1601 if (FD->getOverloadedOperator() != OO_Delete && 1602 FD->getOverloadedOperator() != OO_Array_Delete) 1603 return false; 1604 1605 unsigned UsualParams = 1; 1606 1607 if (S.getLangOpts().SizedDeallocation && UsualParams < FD->getNumParams() && 1608 S.Context.hasSameUnqualifiedType( 1609 FD->getParamDecl(UsualParams)->getType(), 1610 S.Context.getSizeType())) 1611 ++UsualParams; 1612 1613 if (S.getLangOpts().AlignedAllocation && UsualParams < FD->getNumParams() && 1614 S.Context.hasSameUnqualifiedType( 1615 FD->getParamDecl(UsualParams)->getType(), 1616 S.Context.getTypeDeclType(S.getStdAlignValT()))) 1617 ++UsualParams; 1618 1619 return UsualParams == FD->getNumParams(); 1620} 1621 1622namespace { 1623 struct UsualDeallocFnInfo { 1624 UsualDeallocFnInfo() : Found(), FD(nullptr) {} 1625 UsualDeallocFnInfo(Sema &S, DeclAccessPair Found) 1626 : Found(Found), FD(dyn_cast<FunctionDecl>(Found->getUnderlyingDecl())), 1627 Destroying(false), HasSizeT(false), HasAlignValT(false), 1628 CUDAPref(Sema::CFP_Native) { 1629 // A function template declaration is never a usual deallocation function. 1630 if (!FD) 1631 return; 1632 unsigned NumBaseParams = 1; 1633 if (FD->isDestroyingOperatorDelete()) { 1634 Destroying = true; 1635 ++NumBaseParams; 1636 } 1637 1638 if (NumBaseParams < FD->getNumParams() && 1639 S.Context.hasSameUnqualifiedType( 1640 FD->getParamDecl(NumBaseParams)->getType(), 1641 S.Context.getSizeType())) { 1642 ++NumBaseParams; 1643 HasSizeT = true; 1644 } 1645 1646 if (NumBaseParams < FD->getNumParams() && 1647 FD->getParamDecl(NumBaseParams)->getType()->isAlignValT()) { 1648 ++NumBaseParams; 1649 HasAlignValT = true; 1650 } 1651 1652 // In CUDA, determine how much we'd like / dislike to call this. 1653 if (S.getLangOpts().CUDA) 1654 if (auto *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 1655 CUDAPref = S.IdentifyCUDAPreference(Caller, FD); 1656 } 1657 1658 explicit operator bool() const { return FD; } 1659 1660 bool isBetterThan(const UsualDeallocFnInfo &Other, bool WantSize, 1661 bool WantAlign) const { 1662 // C++ P0722: 1663 // A destroying operator delete is preferred over a non-destroying 1664 // operator delete. 1665 if (Destroying != Other.Destroying) 1666 return Destroying; 1667 1668 // C++17 [expr.delete]p10: 1669 // If the type has new-extended alignment, a function with a parameter 1670 // of type std::align_val_t is preferred; otherwise a function without 1671 // such a parameter is preferred 1672 if (HasAlignValT != Other.HasAlignValT) 1673 return HasAlignValT == WantAlign; 1674 1675 if (HasSizeT != Other.HasSizeT) 1676 return HasSizeT == WantSize; 1677 1678 // Use CUDA call preference as a tiebreaker. 1679 return CUDAPref > Other.CUDAPref; 1680 } 1681 1682 DeclAccessPair Found; 1683 FunctionDecl *FD; 1684 bool Destroying, HasSizeT, HasAlignValT; 1685 Sema::CUDAFunctionPreference CUDAPref; 1686 }; 1687} 1688 1689/// Determine whether a type has new-extended alignment. This may be called when 1690/// the type is incomplete (for a delete-expression with an incomplete pointee 1691/// type), in which case it will conservatively return false if the alignment is 1692/// not known. 1693static bool hasNewExtendedAlignment(Sema &S, QualType AllocType) { 1694 return S.getLangOpts().AlignedAllocation && 1695 S.getASTContext().getTypeAlignIfKnown(AllocType) > 1696 S.getASTContext().getTargetInfo().getNewAlign(); 1697} 1698 1699/// Select the correct "usual" deallocation function to use from a selection of 1700/// deallocation functions (either global or class-scope). 1701static UsualDeallocFnInfo resolveDeallocationOverload( 1702 Sema &S, LookupResult &R, bool WantSize, bool WantAlign, 1703 llvm::SmallVectorImpl<UsualDeallocFnInfo> *BestFns = nullptr) { 1704 UsualDeallocFnInfo Best; 1705 1706 for (auto I = R.begin(), E = R.end(); I != E; ++I) { 1707 UsualDeallocFnInfo Info(S, I.getPair()); 1708 if (!Info || !isNonPlacementDeallocationFunction(S, Info.FD) || 1709 Info.CUDAPref == Sema::CFP_Never) 1710 continue; 1711 1712 if (!Best) { 1713 Best = Info; 1714 if (BestFns) 1715 BestFns->push_back(Info); 1716 continue; 1717 } 1718 1719 if (Best.isBetterThan(Info, WantSize, WantAlign)) 1720 continue; 1721 1722 // If more than one preferred function is found, all non-preferred 1723 // functions are eliminated from further consideration. 1724 if (BestFns && Info.isBetterThan(Best, WantSize, WantAlign)) 1725 BestFns->clear(); 1726 1727 Best = Info; 1728 if (BestFns) 1729 BestFns->push_back(Info); 1730 } 1731 1732 return Best; 1733} 1734 1735/// Determine whether a given type is a class for which 'delete[]' would call 1736/// a member 'operator delete[]' with a 'size_t' parameter. This implies that 1737/// we need to store the array size (even if the type is 1738/// trivially-destructible). 1739static bool doesUsualArrayDeleteWantSize(Sema &S, SourceLocation loc, 1740 QualType allocType) { 1741 const RecordType *record = 1742 allocType->getBaseElementTypeUnsafe()->getAs<RecordType>(); 1743 if (!record) return false; 1744 1745 // Try to find an operator delete[] in class scope. 1746 1747 DeclarationName deleteName = 1748 S.Context.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 1749 LookupResult ops(S, deleteName, loc, Sema::LookupOrdinaryName); 1750 S.LookupQualifiedName(ops, record->getDecl()); 1751 1752 // We're just doing this for information. 1753 ops.suppressDiagnostics(); 1754 1755 // Very likely: there's no operator delete[]. 1756 if (ops.empty()) return false; 1757 1758 // If it's ambiguous, it should be illegal to call operator delete[] 1759 // on this thing, so it doesn't matter if we allocate extra space or not. 1760 if (ops.isAmbiguous()) return false; 1761 1762 // C++17 [expr.delete]p10: 1763 // If the deallocation functions have class scope, the one without a 1764 // parameter of type std::size_t is selected. 1765 auto Best = resolveDeallocationOverload( 1766 S, ops, /*WantSize*/false, 1767 /*WantAlign*/hasNewExtendedAlignment(S, allocType)); 1768 return Best && Best.HasSizeT; 1769} 1770 1771/// Parsed a C++ 'new' expression (C++ 5.3.4). 1772/// 1773/// E.g.: 1774/// @code new (memory) int[size][4] @endcode 1775/// or 1776/// @code ::new Foo(23, "hello") @endcode 1777/// 1778/// \param StartLoc The first location of the expression. 1779/// \param UseGlobal True if 'new' was prefixed with '::'. 1780/// \param PlacementLParen Opening paren of the placement arguments. 1781/// \param PlacementArgs Placement new arguments. 1782/// \param PlacementRParen Closing paren of the placement arguments. 1783/// \param TypeIdParens If the type is in parens, the source range. 1784/// \param D The type to be allocated, as well as array dimensions. 1785/// \param Initializer The initializing expression or initializer-list, or null 1786/// if there is none. 1787ExprResult 1788Sema::ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal, 1789 SourceLocation PlacementLParen, MultiExprArg PlacementArgs, 1790 SourceLocation PlacementRParen, SourceRange TypeIdParens, 1791 Declarator &D, Expr *Initializer) { 1792 Optional<Expr *> ArraySize; 1793 // If the specified type is an array, unwrap it and save the expression. 1794 if (D.getNumTypeObjects() > 0 && 1795 D.getTypeObject(0).Kind == DeclaratorChunk::Array) { 1796 DeclaratorChunk &Chunk = D.getTypeObject(0); 1797 if (D.getDeclSpec().hasAutoTypeSpec()) 1798 return ExprError(Diag(Chunk.Loc, diag::err_new_array_of_auto) 1799 << D.getSourceRange()); 1800 if (Chunk.Arr.hasStatic) 1801 return ExprError(Diag(Chunk.Loc, diag::err_static_illegal_in_new) 1802 << D.getSourceRange()); 1803 if (!Chunk.Arr.NumElts && !Initializer) 1804 return ExprError(Diag(Chunk.Loc, diag::err_array_new_needs_size) 1805 << D.getSourceRange()); 1806 1807 ArraySize = static_cast<Expr*>(Chunk.Arr.NumElts); 1808 D.DropFirstTypeObject(); 1809 } 1810 1811 // Every dimension shall be of constant size. 1812 if (ArraySize) { 1813 for (unsigned I = 0, N = D.getNumTypeObjects(); I < N; ++I) { 1814 if (D.getTypeObject(I).Kind != DeclaratorChunk::Array) 1815 break; 1816 1817 DeclaratorChunk::ArrayTypeInfo &Array = D.getTypeObject(I).Arr; 1818 if (Expr *NumElts = (Expr *)Array.NumElts) { 1819 if (!NumElts->isTypeDependent() && !NumElts->isValueDependent()) { 1820 // FIXME: GCC permits constant folding here. We should either do so consistently 1821 // or not do so at all, rather than changing behavior in C++14 onwards. 1822 if (getLangOpts().CPlusPlus14) { 1823 // C++1y [expr.new]p6: Every constant-expression in a noptr-new-declarator 1824 // shall be a converted constant expression (5.19) of type std::size_t 1825 // and shall evaluate to a strictly positive value. 1826 llvm::APSInt Value(Context.getIntWidth(Context.getSizeType())); 1827 Array.NumElts 1828 = CheckConvertedConstantExpression(NumElts, Context.getSizeType(), Value, 1829 CCEK_ArrayBound) 1830 .get(); 1831 } else { 1832 Array.NumElts = 1833 VerifyIntegerConstantExpression( 1834 NumElts, nullptr, diag::err_new_array_nonconst, AllowFold) 1835 .get(); 1836 } 1837 if (!Array.NumElts) 1838 return ExprError(); 1839 } 1840 } 1841 } 1842 } 1843 1844 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, /*Scope=*/nullptr); 1845 QualType AllocType = TInfo->getType(); 1846 if (D.isInvalidType()) 1847 return ExprError(); 1848 1849 SourceRange DirectInitRange; 1850 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) 1851 DirectInitRange = List->getSourceRange(); 1852 1853 return BuildCXXNew(SourceRange(StartLoc, D.getEndLoc()), UseGlobal, 1854 PlacementLParen, PlacementArgs, PlacementRParen, 1855 TypeIdParens, AllocType, TInfo, ArraySize, DirectInitRange, 1856 Initializer); 1857} 1858 1859static bool isLegalArrayNewInitializer(CXXNewExpr::InitializationStyle Style, 1860 Expr *Init) { 1861 if (!Init) 1862 return true; 1863 if (ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) 1864 return PLE->getNumExprs() == 0; 1865 if (isa<ImplicitValueInitExpr>(Init)) 1866 return true; 1867 else if (CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) 1868 return !CCE->isListInitialization() && 1869 CCE->getConstructor()->isDefaultConstructor(); 1870 else if (Style == CXXNewExpr::ListInit) { 1871 assert(isa<InitListExpr>(Init) &&((void)0) 1872 "Shouldn't create list CXXConstructExprs for arrays.")((void)0); 1873 return true; 1874 } 1875 return false; 1876} 1877 1878bool 1879Sema::isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const { 1880 if (!getLangOpts().AlignedAllocationUnavailable) 1881 return false; 1882 if (FD.isDefined()) 1883 return false; 1884 Optional<unsigned> AlignmentParam; 1885 if (FD.isReplaceableGlobalAllocationFunction(&AlignmentParam) && 1886 AlignmentParam.hasValue()) 1887 return true; 1888 return false; 1889} 1890 1891// Emit a diagnostic if an aligned allocation/deallocation function that is not 1892// implemented in the standard library is selected. 1893void Sema::diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD, 1894 SourceLocation Loc) { 1895 if (isUnavailableAlignedAllocationFunction(FD)) { 1896 const llvm::Triple &T = getASTContext().getTargetInfo().getTriple(); 1897 StringRef OSName = AvailabilityAttr::getPlatformNameSourceSpelling( 1898 getASTContext().getTargetInfo().getPlatformName()); 1899 VersionTuple OSVersion = alignedAllocMinVersion(T.getOS()); 1900 1901 OverloadedOperatorKind Kind = FD.getDeclName().getCXXOverloadedOperator(); 1902 bool IsDelete = Kind == OO_Delete || Kind == OO_Array_Delete; 1903 Diag(Loc, diag::err_aligned_allocation_unavailable) 1904 << IsDelete << FD.getType().getAsString() << OSName 1905 << OSVersion.getAsString() << OSVersion.empty(); 1906 Diag(Loc, diag::note_silence_aligned_allocation_unavailable); 1907 } 1908} 1909 1910ExprResult 1911Sema::BuildCXXNew(SourceRange Range, bool UseGlobal, 1912 SourceLocation PlacementLParen, 1913 MultiExprArg PlacementArgs, 1914 SourceLocation PlacementRParen, 1915 SourceRange TypeIdParens, 1916 QualType AllocType, 1917 TypeSourceInfo *AllocTypeInfo, 1918 Optional<Expr *> ArraySize, 1919 SourceRange DirectInitRange, 1920 Expr *Initializer) { 1921 SourceRange TypeRange = AllocTypeInfo->getTypeLoc().getSourceRange(); 1922 SourceLocation StartLoc = Range.getBegin(); 1923 1924 CXXNewExpr::InitializationStyle initStyle; 1925 if (DirectInitRange.isValid()) { 1926 assert(Initializer && "Have parens but no initializer.")((void)0); 1927 initStyle = CXXNewExpr::CallInit; 1928 } else if (Initializer && isa<InitListExpr>(Initializer)) 1929 initStyle = CXXNewExpr::ListInit; 1930 else { 1931 assert((!Initializer || isa<ImplicitValueInitExpr>(Initializer) ||((void)0) 1932 isa<CXXConstructExpr>(Initializer)) &&((void)0) 1933 "Initializer expression that cannot have been implicitly created.")((void)0); 1934 initStyle = CXXNewExpr::NoInit; 1935 } 1936 1937 Expr **Inits = &Initializer; 1938 unsigned NumInits = Initializer ? 1 : 0; 1939 if (ParenListExpr *List = dyn_cast_or_null<ParenListExpr>(Initializer)) { 1940 assert(initStyle == CXXNewExpr::CallInit && "paren init for non-call init")((void)0); 1941 Inits = List->getExprs(); 1942 NumInits = List->getNumExprs(); 1943 } 1944 1945 // C++11 [expr.new]p15: 1946 // A new-expression that creates an object of type T initializes that 1947 // object as follows: 1948 InitializationKind Kind 1949 // - If the new-initializer is omitted, the object is default- 1950 // initialized (8.5); if no initialization is performed, 1951 // the object has indeterminate value 1952 = initStyle == CXXNewExpr::NoInit 1953 ? InitializationKind::CreateDefault(TypeRange.getBegin()) 1954 // - Otherwise, the new-initializer is interpreted according to 1955 // the 1956 // initialization rules of 8.5 for direct-initialization. 1957 : initStyle == CXXNewExpr::ListInit 1958 ? InitializationKind::CreateDirectList( 1959 TypeRange.getBegin(), Initializer->getBeginLoc(), 1960 Initializer->getEndLoc()) 1961 : InitializationKind::CreateDirect(TypeRange.getBegin(), 1962 DirectInitRange.getBegin(), 1963 DirectInitRange.getEnd()); 1964 1965 // C++11 [dcl.spec.auto]p6. Deduce the type which 'auto' stands in for. 1966 auto *Deduced = AllocType->getContainedDeducedType(); 1967 if (Deduced && isa<DeducedTemplateSpecializationType>(Deduced)) { 1968 if (ArraySize) 1969 return ExprError( 1970 Diag(ArraySize ? (*ArraySize)->getExprLoc() : TypeRange.getBegin(), 1971 diag::err_deduced_class_template_compound_type) 1972 << /*array*/ 2 1973 << (ArraySize ? (*ArraySize)->getSourceRange() : TypeRange)); 1974 1975 InitializedEntity Entity 1976 = InitializedEntity::InitializeNew(StartLoc, AllocType); 1977 AllocType = DeduceTemplateSpecializationFromInitializer( 1978 AllocTypeInfo, Entity, Kind, MultiExprArg(Inits, NumInits)); 1979 if (AllocType.isNull()) 1980 return ExprError(); 1981 } else if (Deduced) { 1982 bool Braced = (initStyle == CXXNewExpr::ListInit); 1983 if (NumInits == 1) { 1984 if (auto p = dyn_cast_or_null<InitListExpr>(Inits[0])) { 1985 Inits = p->getInits(); 1986 NumInits = p->getNumInits(); 1987 Braced = true; 1988 } 1989 } 1990 1991 if (initStyle == CXXNewExpr::NoInit || NumInits == 0) 1992 return ExprError(Diag(StartLoc, diag::err_auto_new_requires_ctor_arg) 1993 << AllocType << TypeRange); 1994 if (NumInits > 1) { 1995 Expr *FirstBad = Inits[1]; 1996 return ExprError(Diag(FirstBad->getBeginLoc(), 1997 diag::err_auto_new_ctor_multiple_expressions) 1998 << AllocType << TypeRange); 1999 } 2000 if (Braced && !getLangOpts().CPlusPlus17) 2001 Diag(Initializer->getBeginLoc(), diag::ext_auto_new_list_init) 2002 << AllocType << TypeRange; 2003 Expr *Deduce = Inits[0]; 2004 QualType DeducedType; 2005 if (DeduceAutoType(AllocTypeInfo, Deduce, DeducedType) == DAR_Failed) 2006 return ExprError(Diag(StartLoc, diag::err_auto_new_deduction_failure) 2007 << AllocType << Deduce->getType() 2008 << TypeRange << Deduce->getSourceRange()); 2009 if (DeducedType.isNull()) 2010 return ExprError(); 2011 AllocType = DeducedType; 2012 } 2013 2014 // Per C++0x [expr.new]p5, the type being constructed may be a 2015 // typedef of an array type. 2016 if (!ArraySize) { 2017 if (const ConstantArrayType *Array 2018 = Context.getAsConstantArrayType(AllocType)) { 2019 ArraySize = IntegerLiteral::Create(Context, Array->getSize(), 2020 Context.getSizeType(), 2021 TypeRange.getEnd()); 2022 AllocType = Array->getElementType(); 2023 } 2024 } 2025 2026 if (CheckAllocatedType(AllocType, TypeRange.getBegin(), TypeRange)) 2027 return ExprError(); 2028 2029 // In ARC, infer 'retaining' for the allocated 2030 if (getLangOpts().ObjCAutoRefCount && 2031 AllocType.getObjCLifetime() == Qualifiers::OCL_None && 2032 AllocType->isObjCLifetimeType()) { 2033 AllocType = Context.getLifetimeQualifiedType(AllocType, 2034 AllocType->getObjCARCImplicitLifetime()); 2035 } 2036 2037 QualType ResultType = Context.getPointerType(AllocType); 2038 2039 if (ArraySize && *ArraySize && 2040 (*ArraySize)->getType()->isNonOverloadPlaceholderType()) { 2041 ExprResult result = CheckPlaceholderExpr(*ArraySize); 2042 if (result.isInvalid()) return ExprError(); 2043 ArraySize = result.get(); 2044 } 2045 // C++98 5.3.4p6: "The expression in a direct-new-declarator shall have 2046 // integral or enumeration type with a non-negative value." 2047 // C++11 [expr.new]p6: The expression [...] shall be of integral or unscoped 2048 // enumeration type, or a class type for which a single non-explicit 2049 // conversion function to integral or unscoped enumeration type exists. 2050 // C++1y [expr.new]p6: The expression [...] is implicitly converted to 2051 // std::size_t. 2052 llvm::Optional<uint64_t> KnownArraySize; 2053 if (ArraySize && *ArraySize && !(*ArraySize)->isTypeDependent()) { 2054 ExprResult ConvertedSize; 2055 if (getLangOpts().CPlusPlus14) { 2056 assert(Context.getTargetInfo().getIntWidth() && "Builtin type of size 0?")((void)0); 2057 2058 ConvertedSize = PerformImplicitConversion(*ArraySize, Context.getSizeType(), 2059 AA_Converting); 2060 2061 if (!ConvertedSize.isInvalid() && 2062 (*ArraySize)->getType()->getAs<RecordType>()) 2063 // Diagnose the compatibility of this conversion. 2064 Diag(StartLoc, diag::warn_cxx98_compat_array_size_conversion) 2065 << (*ArraySize)->getType() << 0 << "'size_t'"; 2066 } else { 2067 class SizeConvertDiagnoser : public ICEConvertDiagnoser { 2068 protected: 2069 Expr *ArraySize; 2070 2071 public: 2072 SizeConvertDiagnoser(Expr *ArraySize) 2073 : ICEConvertDiagnoser(/*AllowScopedEnumerations*/false, false, false), 2074 ArraySize(ArraySize) {} 2075 2076 SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, 2077 QualType T) override { 2078 return S.Diag(Loc, diag::err_array_size_not_integral) 2079 << S.getLangOpts().CPlusPlus11 << T; 2080 } 2081 2082 SemaDiagnosticBuilder diagnoseIncomplete( 2083 Sema &S, SourceLocation Loc, QualType T) override { 2084 return S.Diag(Loc, diag::err_array_size_incomplete_type) 2085 << T << ArraySize->getSourceRange(); 2086 } 2087 2088 SemaDiagnosticBuilder diagnoseExplicitConv( 2089 Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) override { 2090 return S.Diag(Loc, diag::err_array_size_explicit_conversion) << T << ConvTy; 2091 } 2092 2093 SemaDiagnosticBuilder noteExplicitConv( 2094 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 2095 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 2096 << ConvTy->isEnumeralType() << ConvTy; 2097 } 2098 2099 SemaDiagnosticBuilder diagnoseAmbiguous( 2100 Sema &S, SourceLocation Loc, QualType T) override { 2101 return S.Diag(Loc, diag::err_array_size_ambiguous_conversion) << T; 2102 } 2103 2104 SemaDiagnosticBuilder noteAmbiguous( 2105 Sema &S, CXXConversionDecl *Conv, QualType ConvTy) override { 2106 return S.Diag(Conv->getLocation(), diag::note_array_size_conversion) 2107 << ConvTy->isEnumeralType() << ConvTy; 2108 } 2109 2110 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 2111 QualType T, 2112 QualType ConvTy) override { 2113 return S.Diag(Loc, 2114 S.getLangOpts().CPlusPlus11 2115 ? diag::warn_cxx98_compat_array_size_conversion 2116 : diag::ext_array_size_conversion) 2117 << T << ConvTy->isEnumeralType() << ConvTy; 2118 } 2119 } SizeDiagnoser(*ArraySize); 2120 2121 ConvertedSize = PerformContextualImplicitConversion(StartLoc, *ArraySize, 2122 SizeDiagnoser); 2123 } 2124 if (ConvertedSize.isInvalid()) 2125 return ExprError(); 2126 2127 ArraySize = ConvertedSize.get(); 2128 QualType SizeType = (*ArraySize)->getType(); 2129 2130 if (!SizeType->isIntegralOrUnscopedEnumerationType()) 2131 return ExprError(); 2132 2133 // C++98 [expr.new]p7: 2134 // The expression in a direct-new-declarator shall have integral type 2135 // with a non-negative value. 2136 // 2137 // Let's see if this is a constant < 0. If so, we reject it out of hand, 2138 // per CWG1464. Otherwise, if it's not a constant, we must have an 2139 // unparenthesized array type. 2140 if (!(*ArraySize)->isValueDependent()) { 2141 // We've already performed any required implicit conversion to integer or 2142 // unscoped enumeration type. 2143 // FIXME: Per CWG1464, we are required to check the value prior to 2144 // converting to size_t. This will never find a negative array size in 2145 // C++14 onwards, because Value is always unsigned here! 2146 if (Optional<llvm::APSInt> Value = 2147 (*ArraySize)->getIntegerConstantExpr(Context)) { 2148 if (Value->isSigned() && Value->isNegative()) { 2149 return ExprError(Diag((*ArraySize)->getBeginLoc(), 2150 diag::err_typecheck_negative_array_size) 2151 << (*ArraySize)->getSourceRange()); 2152 } 2153 2154 if (!AllocType->isDependentType()) { 2155 unsigned ActiveSizeBits = ConstantArrayType::getNumAddressingBits( 2156 Context, AllocType, *Value); 2157 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) 2158 return ExprError( 2159 Diag((*ArraySize)->getBeginLoc(), diag::err_array_too_large) 2160 << toString(*Value, 10) << (*ArraySize)->getSourceRange()); 2161 } 2162 2163 KnownArraySize = Value->getZExtValue(); 2164 } else if (TypeIdParens.isValid()) { 2165 // Can't have dynamic array size when the type-id is in parentheses. 2166 Diag((*ArraySize)->getBeginLoc(), diag::ext_new_paren_array_nonconst) 2167 << (*ArraySize)->getSourceRange() 2168 << FixItHint::CreateRemoval(TypeIdParens.getBegin()) 2169 << FixItHint::CreateRemoval(TypeIdParens.getEnd()); 2170 2171 TypeIdParens = SourceRange(); 2172 } 2173 } 2174 2175 // Note that we do *not* convert the argument in any way. It can 2176 // be signed, larger than size_t, whatever. 2177 } 2178 2179 FunctionDecl *OperatorNew = nullptr; 2180 FunctionDecl *OperatorDelete = nullptr; 2181 unsigned Alignment = 2182 AllocType->isDependentType() ? 0 : Context.getTypeAlign(AllocType); 2183 unsigned NewAlignment = Context.getTargetInfo().getNewAlign(); 2184 bool PassAlignment = getLangOpts().AlignedAllocation && 2185 Alignment > NewAlignment; 2186 2187 AllocationFunctionScope Scope = UseGlobal ? AFS_Global : AFS_Both; 2188 if (!AllocType->isDependentType() && 2189 !Expr::hasAnyTypeDependentArguments(PlacementArgs) && 2190 FindAllocationFunctions( 2191 StartLoc, SourceRange(PlacementLParen, PlacementRParen), Scope, Scope, 2192 AllocType, ArraySize.hasValue(), PassAlignment, PlacementArgs, 2193 OperatorNew, OperatorDelete)) 2194 return ExprError(); 2195 2196 // If this is an array allocation, compute whether the usual array 2197 // deallocation function for the type has a size_t parameter. 2198 bool UsualArrayDeleteWantsSize = false; 2199 if (ArraySize && !AllocType->isDependentType()) 2200 UsualArrayDeleteWantsSize = 2201 doesUsualArrayDeleteWantSize(*this, StartLoc, AllocType); 2202 2203 SmallVector<Expr *, 8> AllPlaceArgs; 2204 if (OperatorNew) { 2205 auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>(); 2206 VariadicCallType CallType = Proto->isVariadic() ? VariadicFunction 2207 : VariadicDoesNotApply; 2208 2209 // We've already converted the placement args, just fill in any default 2210 // arguments. Skip the first parameter because we don't have a corresponding 2211 // argument. Skip the second parameter too if we're passing in the 2212 // alignment; we've already filled it in. 2213 unsigned NumImplicitArgs = PassAlignment ? 2 : 1; 2214 if (GatherArgumentsForCall(PlacementLParen, OperatorNew, Proto, 2215 NumImplicitArgs, PlacementArgs, AllPlaceArgs, 2216 CallType)) 2217 return ExprError(); 2218 2219 if (!AllPlaceArgs.empty()) 2220 PlacementArgs = AllPlaceArgs; 2221 2222 // We would like to perform some checking on the given `operator new` call, 2223 // but the PlacementArgs does not contain the implicit arguments, 2224 // namely allocation size and maybe allocation alignment, 2225 // so we need to conjure them. 2226 2227 QualType SizeTy = Context.getSizeType(); 2228 unsigned SizeTyWidth = Context.getTypeSize(SizeTy); 2229 2230 llvm::APInt SingleEltSize( 2231 SizeTyWidth, Context.getTypeSizeInChars(AllocType).getQuantity()); 2232 2233 // How many bytes do we want to allocate here? 2234 llvm::Optional<llvm::APInt> AllocationSize; 2235 if (!ArraySize.hasValue() && !AllocType->isDependentType()) { 2236 // For non-array operator new, we only want to allocate one element. 2237 AllocationSize = SingleEltSize; 2238 } else if (KnownArraySize.hasValue() && !AllocType->isDependentType()) { 2239 // For array operator new, only deal with static array size case. 2240 bool Overflow; 2241 AllocationSize = llvm::APInt(SizeTyWidth, *KnownArraySize) 2242 .umul_ov(SingleEltSize, Overflow); 2243 (void)Overflow; 2244 assert(((void)0) 2245 !Overflow &&((void)0) 2246 "Expected that all the overflows would have been handled already.")((void)0); 2247 } 2248 2249 IntegerLiteral AllocationSizeLiteral( 2250 Context, 2251 AllocationSize.getValueOr(llvm::APInt::getNullValue(SizeTyWidth)), 2252 SizeTy, SourceLocation()); 2253 // Otherwise, if we failed to constant-fold the allocation size, we'll 2254 // just give up and pass-in something opaque, that isn't a null pointer. 2255 OpaqueValueExpr OpaqueAllocationSize(SourceLocation(), SizeTy, VK_PRValue, 2256 OK_Ordinary, /*SourceExpr=*/nullptr); 2257 2258 // Let's synthesize the alignment argument in case we will need it. 2259 // Since we *really* want to allocate these on stack, this is slightly ugly 2260 // because there might not be a `std::align_val_t` type. 2261 EnumDecl *StdAlignValT = getStdAlignValT(); 2262 QualType AlignValT = 2263 StdAlignValT ? Context.getTypeDeclType(StdAlignValT) : SizeTy; 2264 IntegerLiteral AlignmentLiteral( 2265 Context, 2266 llvm::APInt(Context.getTypeSize(SizeTy), 2267 Alignment / Context.getCharWidth()), 2268 SizeTy, SourceLocation()); 2269 ImplicitCastExpr DesiredAlignment(ImplicitCastExpr::OnStack, AlignValT, 2270 CK_IntegralCast, &AlignmentLiteral, 2271 VK_PRValue, FPOptionsOverride()); 2272 2273 // Adjust placement args by prepending conjured size and alignment exprs. 2274 llvm::SmallVector<Expr *, 8> CallArgs; 2275 CallArgs.reserve(NumImplicitArgs + PlacementArgs.size()); 2276 CallArgs.emplace_back(AllocationSize.hasValue() 2277 ? static_cast<Expr *>(&AllocationSizeLiteral) 2278 : &OpaqueAllocationSize); 2279 if (PassAlignment) 2280 CallArgs.emplace_back(&DesiredAlignment); 2281 CallArgs.insert(CallArgs.end(), PlacementArgs.begin(), PlacementArgs.end()); 2282 2283 DiagnoseSentinelCalls(OperatorNew, PlacementLParen, CallArgs); 2284 2285 checkCall(OperatorNew, Proto, /*ThisArg=*/nullptr, CallArgs, 2286 /*IsMemberFunction=*/false, StartLoc, Range, CallType); 2287 2288 // Warn if the type is over-aligned and is being allocated by (unaligned) 2289 // global operator new. 2290 if (PlacementArgs.empty() && !PassAlignment && 2291 (OperatorNew->isImplicit() || 2292 (OperatorNew->getBeginLoc().isValid() && 2293 getSourceManager().isInSystemHeader(OperatorNew->getBeginLoc())))) { 2294 if (Alignment > NewAlignment) 2295 Diag(StartLoc, diag::warn_overaligned_type) 2296 << AllocType 2297 << unsigned(Alignment / Context.getCharWidth()) 2298 << unsigned(NewAlignment / Context.getCharWidth()); 2299 } 2300 } 2301 2302 // Array 'new' can't have any initializers except empty parentheses. 2303 // Initializer lists are also allowed, in C++11. Rely on the parser for the 2304 // dialect distinction. 2305 if (ArraySize && !isLegalArrayNewInitializer(initStyle, Initializer)) { 2306 SourceRange InitRange(Inits[0]->getBeginLoc(), 2307 Inits[NumInits - 1]->getEndLoc()); 2308 Diag(StartLoc, diag::err_new_array_init_args) << InitRange; 2309 return ExprError(); 2310 } 2311 2312 // If we can perform the initialization, and we've not already done so, 2313 // do it now. 2314 if (!AllocType->isDependentType() && 2315 !Expr::hasAnyTypeDependentArguments( 2316 llvm::makeArrayRef(Inits, NumInits))) { 2317 // The type we initialize is the complete type, including the array bound. 2318 QualType InitType; 2319 if (KnownArraySize) 2320 InitType = Context.getConstantArrayType( 2321 AllocType, 2322 llvm::APInt(Context.getTypeSize(Context.getSizeType()), 2323 *KnownArraySize), 2324 *ArraySize, ArrayType::Normal, 0); 2325 else if (ArraySize) 2326 InitType = 2327 Context.getIncompleteArrayType(AllocType, ArrayType::Normal, 0); 2328 else 2329 InitType = AllocType; 2330 2331 InitializedEntity Entity 2332 = InitializedEntity::InitializeNew(StartLoc, InitType); 2333 InitializationSequence InitSeq(*this, Entity, Kind, 2334 MultiExprArg(Inits, NumInits)); 2335 ExprResult FullInit = InitSeq.Perform(*this, Entity, Kind, 2336 MultiExprArg(Inits, NumInits)); 2337 if (FullInit.isInvalid()) 2338 return ExprError(); 2339 2340 // FullInit is our initializer; strip off CXXBindTemporaryExprs, because 2341 // we don't want the initialized object to be destructed. 2342 // FIXME: We should not create these in the first place. 2343 if (CXXBindTemporaryExpr *Binder = 2344 dyn_cast_or_null<CXXBindTemporaryExpr>(FullInit.get())) 2345 FullInit = Binder->getSubExpr(); 2346 2347 Initializer = FullInit.get(); 2348 2349 // FIXME: If we have a KnownArraySize, check that the array bound of the 2350 // initializer is no greater than that constant value. 2351 2352 if (ArraySize && !*ArraySize) { 2353 auto *CAT = Context.getAsConstantArrayType(Initializer->getType()); 2354 if (CAT) { 2355 // FIXME: Track that the array size was inferred rather than explicitly 2356 // specified. 2357 ArraySize = IntegerLiteral::Create( 2358 Context, CAT->getSize(), Context.getSizeType(), TypeRange.getEnd()); 2359 } else { 2360 Diag(TypeRange.getEnd(), diag::err_new_array_size_unknown_from_init) 2361 << Initializer->getSourceRange(); 2362 } 2363 } 2364 } 2365 2366 // Mark the new and delete operators as referenced. 2367 if (OperatorNew) { 2368 if (DiagnoseUseOfDecl(OperatorNew, StartLoc)) 2369 return ExprError(); 2370 MarkFunctionReferenced(StartLoc, OperatorNew); 2371 } 2372 if (OperatorDelete) { 2373 if (DiagnoseUseOfDecl(OperatorDelete, StartLoc)) 2374 return ExprError(); 2375 MarkFunctionReferenced(StartLoc, OperatorDelete); 2376 } 2377 2378 return CXXNewExpr::Create(Context, UseGlobal, OperatorNew, OperatorDelete, 2379 PassAlignment, UsualArrayDeleteWantsSize, 2380 PlacementArgs, TypeIdParens, ArraySize, initStyle, 2381 Initializer, ResultType, AllocTypeInfo, Range, 2382 DirectInitRange); 2383} 2384 2385/// Checks that a type is suitable as the allocated type 2386/// in a new-expression. 2387bool Sema::CheckAllocatedType(QualType AllocType, SourceLocation Loc, 2388 SourceRange R) { 2389 // C++ 5.3.4p1: "[The] type shall be a complete object type, but not an 2390 // abstract class type or array thereof. 2391 if (AllocType->isFunctionType()) 2392 return Diag(Loc, diag::err_bad_new_type) 2393 << AllocType << 0 << R; 2394 else if (AllocType->isReferenceType()) 2395 return Diag(Loc, diag::err_bad_new_type) 2396 << AllocType << 1 << R; 2397 else if (!AllocType->isDependentType() && 2398 RequireCompleteSizedType( 2399 Loc, AllocType, diag::err_new_incomplete_or_sizeless_type, R)) 2400 return true; 2401 else if (RequireNonAbstractType(Loc, AllocType, 2402 diag::err_allocation_of_abstract_type)) 2403 return true; 2404 else if (AllocType->isVariablyModifiedType()) 2405 return Diag(Loc, diag::err_variably_modified_new_type) 2406 << AllocType; 2407 else if (AllocType.getAddressSpace() != LangAS::Default && 2408 !getLangOpts().OpenCLCPlusPlus) 2409 return Diag(Loc, diag::err_address_space_qualified_new) 2410 << AllocType.getUnqualifiedType() 2411 << AllocType.getQualifiers().getAddressSpaceAttributePrintValue(); 2412 else if (getLangOpts().ObjCAutoRefCount) { 2413 if (const ArrayType *AT = Context.getAsArrayType(AllocType)) { 2414 QualType BaseAllocType = Context.getBaseElementType(AT); 2415 if (BaseAllocType.getObjCLifetime() == Qualifiers::OCL_None && 2416 BaseAllocType->isObjCLifetimeType()) 2417 return Diag(Loc, diag::err_arc_new_array_without_ownership) 2418 << BaseAllocType; 2419 } 2420 } 2421 2422 return false; 2423} 2424 2425static bool resolveAllocationOverload( 2426 Sema &S, LookupResult &R, SourceRange Range, SmallVectorImpl<Expr *> &Args, 2427 bool &PassAlignment, FunctionDecl *&Operator, 2428 OverloadCandidateSet *AlignedCandidates, Expr *AlignArg, bool Diagnose) { 2429 OverloadCandidateSet Candidates(R.getNameLoc(), 2430 OverloadCandidateSet::CSK_Normal); 2431 for (LookupResult::iterator Alloc = R.begin(), AllocEnd = R.end(); 2432 Alloc != AllocEnd; ++Alloc) { 2433 // Even member operator new/delete are implicitly treated as 2434 // static, so don't use AddMemberCandidate. 2435 NamedDecl *D = (*Alloc)->getUnderlyingDecl(); 2436 2437 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 2438 S.AddTemplateOverloadCandidate(FnTemplate, Alloc.getPair(), 2439 /*ExplicitTemplateArgs=*/nullptr, Args, 2440 Candidates, 2441 /*SuppressUserConversions=*/false); 2442 continue; 2443 } 2444 2445 FunctionDecl *Fn = cast<FunctionDecl>(D); 2446 S.AddOverloadCandidate(Fn, Alloc.getPair(), Args, Candidates, 2447 /*SuppressUserConversions=*/false); 2448 } 2449 2450 // Do the resolution. 2451 OverloadCandidateSet::iterator Best; 2452 switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { 2453 case OR_Success: { 2454 // Got one! 2455 FunctionDecl *FnDecl = Best->Function; 2456 if (S.CheckAllocationAccess(R.getNameLoc(), Range, R.getNamingClass(), 2457 Best->FoundDecl) == Sema::AR_inaccessible) 2458 return true; 2459 2460 Operator = FnDecl; 2461 return false; 2462 } 2463 2464 case OR_No_Viable_Function: 2465 // C++17 [expr.new]p13: 2466 // If no matching function is found and the allocated object type has 2467 // new-extended alignment, the alignment argument is removed from the 2468 // argument list, and overload resolution is performed again. 2469 if (PassAlignment) { 2470 PassAlignment = false; 2471 AlignArg = Args[1]; 2472 Args.erase(Args.begin() + 1); 2473 return resolveAllocationOverload(S, R, Range, Args, PassAlignment, 2474 Operator, &Candidates, AlignArg, 2475 Diagnose); 2476 } 2477 2478 // MSVC will fall back on trying to find a matching global operator new 2479 // if operator new[] cannot be found. Also, MSVC will leak by not 2480 // generating a call to operator delete or operator delete[], but we 2481 // will not replicate that bug. 2482 // FIXME: Find out how this interacts with the std::align_val_t fallback 2483 // once MSVC implements it. 2484 if (R.getLookupName().getCXXOverloadedOperator() == OO_Array_New && 2485 S.Context.getLangOpts().MSVCCompat) { 2486 R.clear(); 2487 R.setLookupName(S.Context.DeclarationNames.getCXXOperatorName(OO_New)); 2488 S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); 2489 // FIXME: This will give bad diagnostics pointing at the wrong functions. 2490 return resolveAllocationOverload(S, R, Range, Args, PassAlignment, 2491 Operator, /*Candidates=*/nullptr, 2492 /*AlignArg=*/nullptr, Diagnose); 2493 } 2494 2495 if (Diagnose) { 2496 // If this is an allocation of the form 'new (p) X' for some object 2497 // pointer p (or an expression that will decay to such a pointer), 2498 // diagnose the missing inclusion of <new>. 2499 if (!R.isClassLookup() && Args.size() == 2 && 2500 (Args[1]->getType()->isObjectPointerType() || 2501 Args[1]->getType()->isArrayType())) { 2502 S.Diag(R.getNameLoc(), diag::err_need_header_before_placement_new) 2503 << R.getLookupName() << Range; 2504 // Listing the candidates is unlikely to be useful; skip it. 2505 return true; 2506 } 2507 2508 // Finish checking all candidates before we note any. This checking can 2509 // produce additional diagnostics so can't be interleaved with our 2510 // emission of notes. 2511 // 2512 // For an aligned allocation, separately check the aligned and unaligned 2513 // candidates with their respective argument lists. 2514 SmallVector<OverloadCandidate*, 32> Cands; 2515 SmallVector<OverloadCandidate*, 32> AlignedCands; 2516 llvm::SmallVector<Expr*, 4> AlignedArgs; 2517 if (AlignedCandidates) { 2518 auto IsAligned = [](OverloadCandidate &C) { 2519 return C.Function->getNumParams() > 1 && 2520 C.Function->getParamDecl(1)->getType()->isAlignValT(); 2521 }; 2522 auto IsUnaligned = [&](OverloadCandidate &C) { return !IsAligned(C); }; 2523 2524 AlignedArgs.reserve(Args.size() + 1); 2525 AlignedArgs.push_back(Args[0]); 2526 AlignedArgs.push_back(AlignArg); 2527 AlignedArgs.append(Args.begin() + 1, Args.end()); 2528 AlignedCands = AlignedCandidates->CompleteCandidates( 2529 S, OCD_AllCandidates, AlignedArgs, R.getNameLoc(), IsAligned); 2530 2531 Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, 2532 R.getNameLoc(), IsUnaligned); 2533 } else { 2534 Cands = Candidates.CompleteCandidates(S, OCD_AllCandidates, Args, 2535 R.getNameLoc()); 2536 } 2537 2538 S.Diag(R.getNameLoc(), diag::err_ovl_no_viable_function_in_call) 2539 << R.getLookupName() << Range; 2540 if (AlignedCandidates) 2541 AlignedCandidates->NoteCandidates(S, AlignedArgs, AlignedCands, "", 2542 R.getNameLoc()); 2543 Candidates.NoteCandidates(S, Args, Cands, "", R.getNameLoc()); 2544 } 2545 return true; 2546 2547 case OR_Ambiguous: 2548 if (Diagnose) { 2549 Candidates.NoteCandidates( 2550 PartialDiagnosticAt(R.getNameLoc(), 2551 S.PDiag(diag::err_ovl_ambiguous_call) 2552 << R.getLookupName() << Range), 2553 S, OCD_AmbiguousCandidates, Args); 2554 } 2555 return true; 2556 2557 case OR_Deleted: { 2558 if (Diagnose) { 2559 Candidates.NoteCandidates( 2560 PartialDiagnosticAt(R.getNameLoc(), 2561 S.PDiag(diag::err_ovl_deleted_call) 2562 << R.getLookupName() << Range), 2563 S, OCD_AllCandidates, Args); 2564 } 2565 return true; 2566 } 2567 } 2568 llvm_unreachable("Unreachable, bad result from BestViableFunction")__builtin_unreachable(); 2569} 2570 2571bool Sema::FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range, 2572 AllocationFunctionScope NewScope, 2573 AllocationFunctionScope DeleteScope, 2574 QualType AllocType, bool IsArray, 2575 bool &PassAlignment, MultiExprArg PlaceArgs, 2576 FunctionDecl *&OperatorNew, 2577 FunctionDecl *&OperatorDelete, 2578 bool Diagnose) { 2579 // --- Choosing an allocation function --- 2580 // C++ 5.3.4p8 - 14 & 18 2581 // 1) If looking in AFS_Global scope for allocation functions, only look in 2582 // the global scope. Else, if AFS_Class, only look in the scope of the 2583 // allocated class. If AFS_Both, look in both. 2584 // 2) If an array size is given, look for operator new[], else look for 2585 // operator new. 2586 // 3) The first argument is always size_t. Append the arguments from the 2587 // placement form. 2588 2589 SmallVector<Expr*, 8> AllocArgs; 2590 AllocArgs.reserve((PassAlignment ? 2 : 1) + PlaceArgs.size()); 2591 2592 // We don't care about the actual value of these arguments. 2593 // FIXME: Should the Sema create the expression and embed it in the syntax 2594 // tree? Or should the consumer just recalculate the value? 2595 // FIXME: Using a dummy value will interact poorly with attribute enable_if. 2596 IntegerLiteral Size(Context, llvm::APInt::getNullValue( 2597 Context.getTargetInfo().getPointerWidth(0)), 2598 Context.getSizeType(), 2599 SourceLocation()); 2600 AllocArgs.push_back(&Size); 2601 2602 QualType AlignValT = Context.VoidTy; 2603 if (PassAlignment) { 2604 DeclareGlobalNewDelete(); 2605 AlignValT = Context.getTypeDeclType(getStdAlignValT()); 2606 } 2607 CXXScalarValueInitExpr Align(AlignValT, nullptr, SourceLocation()); 2608 if (PassAlignment) 2609 AllocArgs.push_back(&Align); 2610 2611 AllocArgs.insert(AllocArgs.end(), PlaceArgs.begin(), PlaceArgs.end()); 2612 2613 // C++ [expr.new]p8: 2614 // If the allocated type is a non-array type, the allocation 2615 // function's name is operator new and the deallocation function's 2616 // name is operator delete. If the allocated type is an array 2617 // type, the allocation function's name is operator new[] and the 2618 // deallocation function's name is operator delete[]. 2619 DeclarationName NewName = Context.DeclarationNames.getCXXOperatorName( 2620 IsArray ? OO_Array_New : OO_New); 2621 2622 QualType AllocElemType = Context.getBaseElementType(AllocType); 2623 2624 // Find the allocation function. 2625 { 2626 LookupResult R(*this, NewName, StartLoc, LookupOrdinaryName); 2627 2628 // C++1z [expr.new]p9: 2629 // If the new-expression begins with a unary :: operator, the allocation 2630 // function's name is looked up in the global scope. Otherwise, if the 2631 // allocated type is a class type T or array thereof, the allocation 2632 // function's name is looked up in the scope of T. 2633 if (AllocElemType->isRecordType() && NewScope != AFS_Global) 2634 LookupQualifiedName(R, AllocElemType->getAsCXXRecordDecl()); 2635 2636 // We can see ambiguity here if the allocation function is found in 2637 // multiple base classes. 2638 if (R.isAmbiguous()) 2639 return true; 2640 2641 // If this lookup fails to find the name, or if the allocated type is not 2642 // a class type, the allocation function's name is looked up in the 2643 // global scope. 2644 if (R.empty()) { 2645 if (NewScope == AFS_Class) 2646 return true; 2647 2648 LookupQualifiedName(R, Context.getTranslationUnitDecl()); 2649 } 2650 2651 if (getLangOpts().OpenCLCPlusPlus && R.empty()) { 2652 if (PlaceArgs.empty()) { 2653 Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new"; 2654 } else { 2655 Diag(StartLoc, diag::err_openclcxx_placement_new); 2656 } 2657 return true; 2658 } 2659 2660 assert(!R.empty() && "implicitly declared allocation functions not found")((void)0); 2661 assert(!R.isAmbiguous() && "global allocation functions are ambiguous")((void)0); 2662 2663 // We do our own custom access checks below. 2664 R.suppressDiagnostics(); 2665 2666 if (resolveAllocationOverload(*this, R, Range, AllocArgs, PassAlignment, 2667 OperatorNew, /*Candidates=*/nullptr, 2668 /*AlignArg=*/nullptr, Diagnose)) 2669 return true; 2670 } 2671 2672 // We don't need an operator delete if we're running under -fno-exceptions. 2673 if (!getLangOpts().Exceptions) { 2674 OperatorDelete = nullptr; 2675 return false; 2676 } 2677 2678 // Note, the name of OperatorNew might have been changed from array to 2679 // non-array by resolveAllocationOverload. 2680 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 2681 OperatorNew->getDeclName().getCXXOverloadedOperator() == OO_Array_New 2682 ? OO_Array_Delete 2683 : OO_Delete); 2684 2685 // C++ [expr.new]p19: 2686 // 2687 // If the new-expression begins with a unary :: operator, the 2688 // deallocation function's name is looked up in the global 2689 // scope. Otherwise, if the allocated type is a class type T or an 2690 // array thereof, the deallocation function's name is looked up in 2691 // the scope of T. If this lookup fails to find the name, or if 2692 // the allocated type is not a class type or array thereof, the 2693 // deallocation function's name is looked up in the global scope. 2694 LookupResult FoundDelete(*this, DeleteName, StartLoc, LookupOrdinaryName); 2695 if (AllocElemType->isRecordType() && DeleteScope != AFS_Global) { 2696 auto *RD = 2697 cast<CXXRecordDecl>(AllocElemType->castAs<RecordType>()->getDecl()); 2698 LookupQualifiedName(FoundDelete, RD); 2699 } 2700 if (FoundDelete.isAmbiguous()) 2701 return true; // FIXME: clean up expressions? 2702 2703 // Filter out any destroying operator deletes. We can't possibly call such a 2704 // function in this context, because we're handling the case where the object 2705 // was not successfully constructed. 2706 // FIXME: This is not covered by the language rules yet. 2707 { 2708 LookupResult::Filter Filter = FoundDelete.makeFilter(); 2709 while (Filter.hasNext()) { 2710 auto *FD = dyn_cast<FunctionDecl>(Filter.next()->getUnderlyingDecl()); 2711 if (FD && FD->isDestroyingOperatorDelete()) 2712 Filter.erase(); 2713 } 2714 Filter.done(); 2715 } 2716 2717 bool FoundGlobalDelete = FoundDelete.empty(); 2718 if (FoundDelete.empty()) { 2719 FoundDelete.clear(LookupOrdinaryName); 2720 2721 if (DeleteScope == AFS_Class) 2722 return true; 2723 2724 DeclareGlobalNewDelete(); 2725 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 2726 } 2727 2728 FoundDelete.suppressDiagnostics(); 2729 2730 SmallVector<std::pair<DeclAccessPair,FunctionDecl*>, 2> Matches; 2731 2732 // Whether we're looking for a placement operator delete is dictated 2733 // by whether we selected a placement operator new, not by whether 2734 // we had explicit placement arguments. This matters for things like 2735 // struct A { void *operator new(size_t, int = 0); ... }; 2736 // A *a = new A() 2737 // 2738 // We don't have any definition for what a "placement allocation function" 2739 // is, but we assume it's any allocation function whose 2740 // parameter-declaration-clause is anything other than (size_t). 2741 // 2742 // FIXME: Should (size_t, std::align_val_t) also be considered non-placement? 2743 // This affects whether an exception from the constructor of an overaligned 2744 // type uses the sized or non-sized form of aligned operator delete. 2745 bool isPlacementNew = !PlaceArgs.empty() || OperatorNew->param_size() != 1 || 2746 OperatorNew->isVariadic(); 2747 2748 if (isPlacementNew) { 2749 // C++ [expr.new]p20: 2750 // A declaration of a placement deallocation function matches the 2751 // declaration of a placement allocation function if it has the 2752 // same number of parameters and, after parameter transformations 2753 // (8.3.5), all parameter types except the first are 2754 // identical. [...] 2755 // 2756 // To perform this comparison, we compute the function type that 2757 // the deallocation function should have, and use that type both 2758 // for template argument deduction and for comparison purposes. 2759 QualType ExpectedFunctionType; 2760 { 2761 auto *Proto = OperatorNew->getType()->castAs<FunctionProtoType>(); 2762 2763 SmallVector<QualType, 4> ArgTypes; 2764 ArgTypes.push_back(Context.VoidPtrTy); 2765 for (unsigned I = 1, N = Proto->getNumParams(); I < N; ++I) 2766 ArgTypes.push_back(Proto->getParamType(I)); 2767 2768 FunctionProtoType::ExtProtoInfo EPI; 2769 // FIXME: This is not part of the standard's rule. 2770 EPI.Variadic = Proto->isVariadic(); 2771 2772 ExpectedFunctionType 2773 = Context.getFunctionType(Context.VoidTy, ArgTypes, EPI); 2774 } 2775 2776 for (LookupResult::iterator D = FoundDelete.begin(), 2777 DEnd = FoundDelete.end(); 2778 D != DEnd; ++D) { 2779 FunctionDecl *Fn = nullptr; 2780 if (FunctionTemplateDecl *FnTmpl = 2781 dyn_cast<FunctionTemplateDecl>((*D)->getUnderlyingDecl())) { 2782 // Perform template argument deduction to try to match the 2783 // expected function type. 2784 TemplateDeductionInfo Info(StartLoc); 2785 if (DeduceTemplateArguments(FnTmpl, nullptr, ExpectedFunctionType, Fn, 2786 Info)) 2787 continue; 2788 } else 2789 Fn = cast<FunctionDecl>((*D)->getUnderlyingDecl()); 2790 2791 if (Context.hasSameType(adjustCCAndNoReturn(Fn->getType(), 2792 ExpectedFunctionType, 2793 /*AdjustExcpetionSpec*/true), 2794 ExpectedFunctionType)) 2795 Matches.push_back(std::make_pair(D.getPair(), Fn)); 2796 } 2797 2798 if (getLangOpts().CUDA) 2799 EraseUnwantedCUDAMatches(dyn_cast<FunctionDecl>(CurContext), Matches); 2800 } else { 2801 // C++1y [expr.new]p22: 2802 // For a non-placement allocation function, the normal deallocation 2803 // function lookup is used 2804 // 2805 // Per [expr.delete]p10, this lookup prefers a member operator delete 2806 // without a size_t argument, but prefers a non-member operator delete 2807 // with a size_t where possible (which it always is in this case). 2808 llvm::SmallVector<UsualDeallocFnInfo, 4> BestDeallocFns; 2809 UsualDeallocFnInfo Selected = resolveDeallocationOverload( 2810 *this, FoundDelete, /*WantSize*/ FoundGlobalDelete, 2811 /*WantAlign*/ hasNewExtendedAlignment(*this, AllocElemType), 2812 &BestDeallocFns); 2813 if (Selected) 2814 Matches.push_back(std::make_pair(Selected.Found, Selected.FD)); 2815 else { 2816 // If we failed to select an operator, all remaining functions are viable 2817 // but ambiguous. 2818 for (auto Fn : BestDeallocFns) 2819 Matches.push_back(std::make_pair(Fn.Found, Fn.FD)); 2820 } 2821 } 2822 2823 // C++ [expr.new]p20: 2824 // [...] If the lookup finds a single matching deallocation 2825 // function, that function will be called; otherwise, no 2826 // deallocation function will be called. 2827 if (Matches.size() == 1) { 2828 OperatorDelete = Matches[0].second; 2829 2830 // C++1z [expr.new]p23: 2831 // If the lookup finds a usual deallocation function (3.7.4.2) 2832 // with a parameter of type std::size_t and that function, considered 2833 // as a placement deallocation function, would have been 2834 // selected as a match for the allocation function, the program 2835 // is ill-formed. 2836 if (getLangOpts().CPlusPlus11 && isPlacementNew && 2837 isNonPlacementDeallocationFunction(*this, OperatorDelete)) { 2838 UsualDeallocFnInfo Info(*this, 2839 DeclAccessPair::make(OperatorDelete, AS_public)); 2840 // Core issue, per mail to core reflector, 2016-10-09: 2841 // If this is a member operator delete, and there is a corresponding 2842 // non-sized member operator delete, this isn't /really/ a sized 2843 // deallocation function, it just happens to have a size_t parameter. 2844 bool IsSizedDelete = Info.HasSizeT; 2845 if (IsSizedDelete && !FoundGlobalDelete) { 2846 auto NonSizedDelete = 2847 resolveDeallocationOverload(*this, FoundDelete, /*WantSize*/false, 2848 /*WantAlign*/Info.HasAlignValT); 2849 if (NonSizedDelete && !NonSizedDelete.HasSizeT && 2850 NonSizedDelete.HasAlignValT == Info.HasAlignValT) 2851 IsSizedDelete = false; 2852 } 2853 2854 if (IsSizedDelete) { 2855 SourceRange R = PlaceArgs.empty() 2856 ? SourceRange() 2857 : SourceRange(PlaceArgs.front()->getBeginLoc(), 2858 PlaceArgs.back()->getEndLoc()); 2859 Diag(StartLoc, diag::err_placement_new_non_placement_delete) << R; 2860 if (!OperatorDelete->isImplicit()) 2861 Diag(OperatorDelete->getLocation(), diag::note_previous_decl) 2862 << DeleteName; 2863 } 2864 } 2865 2866 CheckAllocationAccess(StartLoc, Range, FoundDelete.getNamingClass(), 2867 Matches[0].first); 2868 } else if (!Matches.empty()) { 2869 // We found multiple suitable operators. Per [expr.new]p20, that means we 2870 // call no 'operator delete' function, but we should at least warn the user. 2871 // FIXME: Suppress this warning if the construction cannot throw. 2872 Diag(StartLoc, diag::warn_ambiguous_suitable_delete_function_found) 2873 << DeleteName << AllocElemType; 2874 2875 for (auto &Match : Matches) 2876 Diag(Match.second->getLocation(), 2877 diag::note_member_declared_here) << DeleteName; 2878 } 2879 2880 return false; 2881} 2882 2883/// DeclareGlobalNewDelete - Declare the global forms of operator new and 2884/// delete. These are: 2885/// @code 2886/// // C++03: 2887/// void* operator new(std::size_t) throw(std::bad_alloc); 2888/// void* operator new[](std::size_t) throw(std::bad_alloc); 2889/// void operator delete(void *) throw(); 2890/// void operator delete[](void *) throw(); 2891/// // C++11: 2892/// void* operator new(std::size_t); 2893/// void* operator new[](std::size_t); 2894/// void operator delete(void *) noexcept; 2895/// void operator delete[](void *) noexcept; 2896/// // C++1y: 2897/// void* operator new(std::size_t); 2898/// void* operator new[](std::size_t); 2899/// void operator delete(void *) noexcept; 2900/// void operator delete[](void *) noexcept; 2901/// void operator delete(void *, std::size_t) noexcept; 2902/// void operator delete[](void *, std::size_t) noexcept; 2903/// @endcode 2904/// Note that the placement and nothrow forms of new are *not* implicitly 2905/// declared. Their use requires including \<new\>. 2906void Sema::DeclareGlobalNewDelete() { 2907 if (GlobalNewDeleteDeclared) 2908 return; 2909 2910 // The implicitly declared new and delete operators 2911 // are not supported in OpenCL. 2912 if (getLangOpts().OpenCLCPlusPlus) 2913 return; 2914 2915 // C++ [basic.std.dynamic]p2: 2916 // [...] The following allocation and deallocation functions (18.4) are 2917 // implicitly declared in global scope in each translation unit of a 2918 // program 2919 // 2920 // C++03: 2921 // void* operator new(std::size_t) throw(std::bad_alloc); 2922 // void* operator new[](std::size_t) throw(std::bad_alloc); 2923 // void operator delete(void*) throw(); 2924 // void operator delete[](void*) throw(); 2925 // C++11: 2926 // void* operator new(std::size_t); 2927 // void* operator new[](std::size_t); 2928 // void operator delete(void*) noexcept; 2929 // void operator delete[](void*) noexcept; 2930 // C++1y: 2931 // void* operator new(std::size_t); 2932 // void* operator new[](std::size_t); 2933 // void operator delete(void*) noexcept; 2934 // void operator delete[](void*) noexcept; 2935 // void operator delete(void*, std::size_t) noexcept; 2936 // void operator delete[](void*, std::size_t) noexcept; 2937 // 2938 // These implicit declarations introduce only the function names operator 2939 // new, operator new[], operator delete, operator delete[]. 2940 // 2941 // Here, we need to refer to std::bad_alloc, so we will implicitly declare 2942 // "std" or "bad_alloc" as necessary to form the exception specification. 2943 // However, we do not make these implicit declarations visible to name 2944 // lookup. 2945 if (!StdBadAlloc && !getLangOpts().CPlusPlus11) { 2946 // The "std::bad_alloc" class has not yet been declared, so build it 2947 // implicitly. 2948 StdBadAlloc = CXXRecordDecl::Create(Context, TTK_Class, 2949 getOrCreateStdNamespace(), 2950 SourceLocation(), SourceLocation(), 2951 &PP.getIdentifierTable().get("bad_alloc"), 2952 nullptr); 2953 getStdBadAlloc()->setImplicit(true); 2954 } 2955 if (!StdAlignValT && getLangOpts().AlignedAllocation) { 2956 // The "std::align_val_t" enum class has not yet been declared, so build it 2957 // implicitly. 2958 auto *AlignValT = EnumDecl::Create( 2959 Context, getOrCreateStdNamespace(), SourceLocation(), SourceLocation(), 2960 &PP.getIdentifierTable().get("align_val_t"), nullptr, true, true, true); 2961 AlignValT->setIntegerType(Context.getSizeType()); 2962 AlignValT->setPromotionType(Context.getSizeType()); 2963 AlignValT->setImplicit(true); 2964 StdAlignValT = AlignValT; 2965 } 2966 2967 GlobalNewDeleteDeclared = true; 2968 2969 QualType VoidPtr = Context.getPointerType(Context.VoidTy); 2970 QualType SizeT = Context.getSizeType(); 2971 2972 auto DeclareGlobalAllocationFunctions = [&](OverloadedOperatorKind Kind, 2973 QualType Return, QualType Param) { 2974 llvm::SmallVector<QualType, 3> Params; 2975 Params.push_back(Param); 2976 2977 // Create up to four variants of the function (sized/aligned). 2978 bool HasSizedVariant = getLangOpts().SizedDeallocation && 2979 (Kind == OO_Delete || Kind == OO_Array_Delete); 2980 bool HasAlignedVariant = getLangOpts().AlignedAllocation; 2981 2982 int NumSizeVariants = (HasSizedVariant ? 2 : 1); 2983 int NumAlignVariants = (HasAlignedVariant ? 2 : 1); 2984 for (int Sized = 0; Sized < NumSizeVariants; ++Sized) { 2985 if (Sized) 2986 Params.push_back(SizeT); 2987 2988 for (int Aligned = 0; Aligned < NumAlignVariants; ++Aligned) { 2989 if (Aligned) 2990 Params.push_back(Context.getTypeDeclType(getStdAlignValT())); 2991 2992 DeclareGlobalAllocationFunction( 2993 Context.DeclarationNames.getCXXOperatorName(Kind), Return, Params); 2994 2995 if (Aligned) 2996 Params.pop_back(); 2997 } 2998 } 2999 }; 3000 3001 DeclareGlobalAllocationFunctions(OO_New, VoidPtr, SizeT); 3002 DeclareGlobalAllocationFunctions(OO_Array_New, VoidPtr, SizeT); 3003 DeclareGlobalAllocationFunctions(OO_Delete, Context.VoidTy, VoidPtr); 3004 DeclareGlobalAllocationFunctions(OO_Array_Delete, Context.VoidTy, VoidPtr); 3005} 3006 3007/// DeclareGlobalAllocationFunction - Declares a single implicit global 3008/// allocation function if it doesn't already exist. 3009void Sema::DeclareGlobalAllocationFunction(DeclarationName Name, 3010 QualType Return, 3011 ArrayRef<QualType> Params) { 3012 DeclContext *GlobalCtx = Context.getTranslationUnitDecl(); 3013 3014 // Check if this function is already declared. 3015 DeclContext::lookup_result R = GlobalCtx->lookup(Name); 3016 for (DeclContext::lookup_iterator Alloc = R.begin(), AllocEnd = R.end(); 3017 Alloc != AllocEnd; ++Alloc) { 3018 // Only look at non-template functions, as it is the predefined, 3019 // non-templated allocation function we are trying to declare here. 3020 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(*Alloc)) { 3021 if (Func->getNumParams() == Params.size()) { 3022 llvm::SmallVector<QualType, 3> FuncParams; 3023 for (auto *P : Func->parameters()) 3024 FuncParams.push_back( 3025 Context.getCanonicalType(P->getType().getUnqualifiedType())); 3026 if (llvm::makeArrayRef(FuncParams) == Params) { 3027 // Make the function visible to name lookup, even if we found it in 3028 // an unimported module. It either is an implicitly-declared global 3029 // allocation function, or is suppressing that function. 3030 Func->setVisibleDespiteOwningModule(); 3031 return; 3032 } 3033 } 3034 } 3035 } 3036 3037 FunctionProtoType::ExtProtoInfo EPI(Context.getDefaultCallingConvention( 3038 /*IsVariadic=*/false, /*IsCXXMethod=*/false, /*IsBuiltin=*/true)); 3039 3040 QualType BadAllocType; 3041 bool HasBadAllocExceptionSpec 3042 = (Name.getCXXOverloadedOperator() == OO_New || 3043 Name.getCXXOverloadedOperator() == OO_Array_New); 3044 if (HasBadAllocExceptionSpec) { 3045 if (!getLangOpts().CPlusPlus11) { 3046 BadAllocType = Context.getTypeDeclType(getStdBadAlloc()); 3047 assert(StdBadAlloc && "Must have std::bad_alloc declared")((void)0); 3048 EPI.ExceptionSpec.Type = EST_Dynamic; 3049 EPI.ExceptionSpec.Exceptions = llvm::makeArrayRef(BadAllocType); 3050 } 3051 } else { 3052 EPI.ExceptionSpec = 3053 getLangOpts().CPlusPlus11 ? EST_BasicNoexcept : EST_DynamicNone; 3054 } 3055 3056 auto CreateAllocationFunctionDecl = [&](Attr *ExtraAttr) { 3057 QualType FnType = Context.getFunctionType(Return, Params, EPI); 3058 FunctionDecl *Alloc = FunctionDecl::Create( 3059 Context, GlobalCtx, SourceLocation(), SourceLocation(), Name, 3060 FnType, /*TInfo=*/nullptr, SC_None, false, true); 3061 Alloc->setImplicit(); 3062 // Global allocation functions should always be visible. 3063 Alloc->setVisibleDespiteOwningModule(); 3064 3065 Alloc->addAttr(VisibilityAttr::CreateImplicit( 3066 Context, LangOpts.GlobalAllocationFunctionVisibilityHidden 3067 ? VisibilityAttr::Hidden 3068 : VisibilityAttr::Default)); 3069 3070 llvm::SmallVector<ParmVarDecl *, 3> ParamDecls; 3071 for (QualType T : Params) { 3072 ParamDecls.push_back(ParmVarDecl::Create( 3073 Context, Alloc, SourceLocation(), SourceLocation(), nullptr, T, 3074 /*TInfo=*/nullptr, SC_None, nullptr)); 3075 ParamDecls.back()->setImplicit(); 3076 } 3077 Alloc->setParams(ParamDecls); 3078 if (ExtraAttr) 3079 Alloc->addAttr(ExtraAttr); 3080 AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(Alloc); 3081 Context.getTranslationUnitDecl()->addDecl(Alloc); 3082 IdResolver.tryAddTopLevelDecl(Alloc, Name); 3083 }; 3084 3085 if (!LangOpts.CUDA) 3086 CreateAllocationFunctionDecl(nullptr); 3087 else { 3088 // Host and device get their own declaration so each can be 3089 // defined or re-declared independently. 3090 CreateAllocationFunctionDecl(CUDAHostAttr::CreateImplicit(Context)); 3091 CreateAllocationFunctionDecl(CUDADeviceAttr::CreateImplicit(Context)); 3092 } 3093} 3094 3095FunctionDecl *Sema::FindUsualDeallocationFunction(SourceLocation StartLoc, 3096 bool CanProvideSize, 3097 bool Overaligned, 3098 DeclarationName Name) { 3099 DeclareGlobalNewDelete(); 3100 3101 LookupResult FoundDelete(*this, Name, StartLoc, LookupOrdinaryName); 3102 LookupQualifiedName(FoundDelete, Context.getTranslationUnitDecl()); 3103 3104 // FIXME: It's possible for this to result in ambiguity, through a 3105 // user-declared variadic operator delete or the enable_if attribute. We 3106 // should probably not consider those cases to be usual deallocation 3107 // functions. But for now we just make an arbitrary choice in that case. 3108 auto Result = resolveDeallocationOverload(*this, FoundDelete, CanProvideSize, 3109 Overaligned); 3110 assert(Result.FD && "operator delete missing from global scope?")((void)0); 3111 return Result.FD; 3112} 3113 3114FunctionDecl *Sema::FindDeallocationFunctionForDestructor(SourceLocation Loc, 3115 CXXRecordDecl *RD) { 3116 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Delete); 3117 3118 FunctionDecl *OperatorDelete = nullptr; 3119 if (FindDeallocationFunction(Loc, RD, Name, OperatorDelete)) 3120 return nullptr; 3121 if (OperatorDelete) 3122 return OperatorDelete; 3123 3124 // If there's no class-specific operator delete, look up the global 3125 // non-array delete. 3126 return FindUsualDeallocationFunction( 3127 Loc, true, hasNewExtendedAlignment(*this, Context.getRecordType(RD)), 3128 Name); 3129} 3130 3131bool Sema::FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD, 3132 DeclarationName Name, 3133 FunctionDecl *&Operator, bool Diagnose) { 3134 LookupResult Found(*this, Name, StartLoc, LookupOrdinaryName); 3135 // Try to find operator delete/operator delete[] in class scope. 3136 LookupQualifiedName(Found, RD); 3137 3138 if (Found.isAmbiguous()) 3139 return true; 3140 3141 Found.suppressDiagnostics(); 3142 3143 bool Overaligned = hasNewExtendedAlignment(*this, Context.getRecordType(RD)); 3144 3145 // C++17 [expr.delete]p10: 3146 // If the deallocation functions have class scope, the one without a 3147 // parameter of type std::size_t is selected. 3148 llvm::SmallVector<UsualDeallocFnInfo, 4> Matches; 3149 resolveDeallocationOverload(*this, Found, /*WantSize*/ false, 3150 /*WantAlign*/ Overaligned, &Matches); 3151 3152 // If we could find an overload, use it. 3153 if (Matches.size() == 1) { 3154 Operator = cast<CXXMethodDecl>(Matches[0].FD); 3155 3156 // FIXME: DiagnoseUseOfDecl? 3157 if (Operator->isDeleted()) { 3158 if (Diagnose) { 3159 Diag(StartLoc, diag::err_deleted_function_use); 3160 NoteDeletedFunction(Operator); 3161 } 3162 return true; 3163 } 3164 3165 if (CheckAllocationAccess(StartLoc, SourceRange(), Found.getNamingClass(), 3166 Matches[0].Found, Diagnose) == AR_inaccessible) 3167 return true; 3168 3169 return false; 3170 } 3171 3172 // We found multiple suitable operators; complain about the ambiguity. 3173 // FIXME: The standard doesn't say to do this; it appears that the intent 3174 // is that this should never happen. 3175 if (!Matches.empty()) { 3176 if (Diagnose) { 3177 Diag(StartLoc, diag::err_ambiguous_suitable_delete_member_function_found) 3178 << Name << RD; 3179 for (auto &Match : Matches) 3180 Diag(Match.FD->getLocation(), diag::note_member_declared_here) << Name; 3181 } 3182 return true; 3183 } 3184 3185 // We did find operator delete/operator delete[] declarations, but 3186 // none of them were suitable. 3187 if (!Found.empty()) { 3188 if (Diagnose) { 3189 Diag(StartLoc, diag::err_no_suitable_delete_member_function_found) 3190 << Name << RD; 3191 3192 for (NamedDecl *D : Found) 3193 Diag(D->getUnderlyingDecl()->getLocation(), 3194 diag::note_member_declared_here) << Name; 3195 } 3196 return true; 3197 } 3198 3199 Operator = nullptr; 3200 return false; 3201} 3202 3203namespace { 3204/// Checks whether delete-expression, and new-expression used for 3205/// initializing deletee have the same array form. 3206class MismatchingNewDeleteDetector { 3207public: 3208 enum MismatchResult { 3209 /// Indicates that there is no mismatch or a mismatch cannot be proven. 3210 NoMismatch, 3211 /// Indicates that variable is initialized with mismatching form of \a new. 3212 VarInitMismatches, 3213 /// Indicates that member is initialized with mismatching form of \a new. 3214 MemberInitMismatches, 3215 /// Indicates that 1 or more constructors' definitions could not been 3216 /// analyzed, and they will be checked again at the end of translation unit. 3217 AnalyzeLater 3218 }; 3219 3220 /// \param EndOfTU True, if this is the final analysis at the end of 3221 /// translation unit. False, if this is the initial analysis at the point 3222 /// delete-expression was encountered. 3223 explicit MismatchingNewDeleteDetector(bool EndOfTU) 3224 : Field(nullptr), IsArrayForm(false), EndOfTU(EndOfTU), 3225 HasUndefinedConstructors(false) {} 3226 3227 /// Checks whether pointee of a delete-expression is initialized with 3228 /// matching form of new-expression. 3229 /// 3230 /// If return value is \c VarInitMismatches or \c MemberInitMismatches at the 3231 /// point where delete-expression is encountered, then a warning will be 3232 /// issued immediately. If return value is \c AnalyzeLater at the point where 3233 /// delete-expression is seen, then member will be analyzed at the end of 3234 /// translation unit. \c AnalyzeLater is returned iff at least one constructor 3235 /// couldn't be analyzed. If at least one constructor initializes the member 3236 /// with matching type of new, the return value is \c NoMismatch. 3237 MismatchResult analyzeDeleteExpr(const CXXDeleteExpr *DE); 3238 /// Analyzes a class member. 3239 /// \param Field Class member to analyze. 3240 /// \param DeleteWasArrayForm Array form-ness of the delete-expression used 3241 /// for deleting the \p Field. 3242 MismatchResult analyzeField(FieldDecl *Field, bool DeleteWasArrayForm); 3243 FieldDecl *Field; 3244 /// List of mismatching new-expressions used for initialization of the pointee 3245 llvm::SmallVector<const CXXNewExpr *, 4> NewExprs; 3246 /// Indicates whether delete-expression was in array form. 3247 bool IsArrayForm; 3248 3249private: 3250 const bool EndOfTU; 3251 /// Indicates that there is at least one constructor without body. 3252 bool HasUndefinedConstructors; 3253 /// Returns \c CXXNewExpr from given initialization expression. 3254 /// \param E Expression used for initializing pointee in delete-expression. 3255 /// E can be a single-element \c InitListExpr consisting of new-expression. 3256 const CXXNewExpr *getNewExprFromInitListOrExpr(const Expr *E); 3257 /// Returns whether member is initialized with mismatching form of 3258 /// \c new either by the member initializer or in-class initialization. 3259 /// 3260 /// If bodies of all constructors are not visible at the end of translation 3261 /// unit or at least one constructor initializes member with the matching 3262 /// form of \c new, mismatch cannot be proven, and this function will return 3263 /// \c NoMismatch. 3264 MismatchResult analyzeMemberExpr(const MemberExpr *ME); 3265 /// Returns whether variable is initialized with mismatching form of 3266 /// \c new. 3267 /// 3268 /// If variable is initialized with matching form of \c new or variable is not 3269 /// initialized with a \c new expression, this function will return true. 3270 /// If variable is initialized with mismatching form of \c new, returns false. 3271 /// \param D Variable to analyze. 3272 bool hasMatchingVarInit(const DeclRefExpr *D); 3273 /// Checks whether the constructor initializes pointee with mismatching 3274 /// form of \c new. 3275 /// 3276 /// Returns true, if member is initialized with matching form of \c new in 3277 /// member initializer list. Returns false, if member is initialized with the 3278 /// matching form of \c new in this constructor's initializer or given 3279 /// constructor isn't defined at the point where delete-expression is seen, or 3280 /// member isn't initialized by the constructor. 3281 bool hasMatchingNewInCtor(const CXXConstructorDecl *CD); 3282 /// Checks whether member is initialized with matching form of 3283 /// \c new in member initializer list. 3284 bool hasMatchingNewInCtorInit(const CXXCtorInitializer *CI); 3285 /// Checks whether member is initialized with mismatching form of \c new by 3286 /// in-class initializer. 3287 MismatchResult analyzeInClassInitializer(); 3288}; 3289} 3290 3291MismatchingNewDeleteDetector::MismatchResult 3292MismatchingNewDeleteDetector::analyzeDeleteExpr(const CXXDeleteExpr *DE) { 3293 NewExprs.clear(); 3294 assert(DE && "Expected delete-expression")((void)0); 3295 IsArrayForm = DE->isArrayForm(); 3296 const Expr *E = DE->getArgument()->IgnoreParenImpCasts(); 3297 if (const MemberExpr *ME = dyn_cast<const MemberExpr>(E)) { 3298 return analyzeMemberExpr(ME); 3299 } else if (const DeclRefExpr *D = dyn_cast<const DeclRefExpr>(E)) { 3300 if (!hasMatchingVarInit(D)) 3301 return VarInitMismatches; 3302 } 3303 return NoMismatch; 3304} 3305 3306const CXXNewExpr * 3307MismatchingNewDeleteDetector::getNewExprFromInitListOrExpr(const Expr *E) { 3308 assert(E != nullptr && "Expected a valid initializer expression")((void)0); 3309 E = E->IgnoreParenImpCasts(); 3310 if (const InitListExpr *ILE = dyn_cast<const InitListExpr>(E)) { 3311 if (ILE->getNumInits() == 1) 3312 E = dyn_cast<const CXXNewExpr>(ILE->getInit(0)->IgnoreParenImpCasts()); 3313 } 3314 3315 return dyn_cast_or_null<const CXXNewExpr>(E); 3316} 3317 3318bool MismatchingNewDeleteDetector::hasMatchingNewInCtorInit( 3319 const CXXCtorInitializer *CI) { 3320 const CXXNewExpr *NE = nullptr; 3321 if (Field == CI->getMember() && 3322 (NE = getNewExprFromInitListOrExpr(CI->getInit()))) { 3323 if (NE->isArray() == IsArrayForm) 3324 return true; 3325 else 3326 NewExprs.push_back(NE); 3327 } 3328 return false; 3329} 3330 3331bool MismatchingNewDeleteDetector::hasMatchingNewInCtor( 3332 const CXXConstructorDecl *CD) { 3333 if (CD->isImplicit()) 3334 return false; 3335 const FunctionDecl *Definition = CD; 3336 if (!CD->isThisDeclarationADefinition() && !CD->isDefined(Definition)) { 3337 HasUndefinedConstructors = true; 3338 return EndOfTU; 3339 } 3340 for (const auto *CI : cast<const CXXConstructorDecl>(Definition)->inits()) { 3341 if (hasMatchingNewInCtorInit(CI)) 3342 return true; 3343 } 3344 return false; 3345} 3346 3347MismatchingNewDeleteDetector::MismatchResult 3348MismatchingNewDeleteDetector::analyzeInClassInitializer() { 3349 assert(Field != nullptr && "This should be called only for members")((void)0); 3350 const Expr *InitExpr = Field->getInClassInitializer(); 3351 if (!InitExpr) 3352 return EndOfTU ? NoMismatch : AnalyzeLater; 3353 if (const CXXNewExpr *NE = getNewExprFromInitListOrExpr(InitExpr)) { 3354 if (NE->isArray() != IsArrayForm) { 3355 NewExprs.push_back(NE); 3356 return MemberInitMismatches; 3357 } 3358 } 3359 return NoMismatch; 3360} 3361 3362MismatchingNewDeleteDetector::MismatchResult 3363MismatchingNewDeleteDetector::analyzeField(FieldDecl *Field, 3364 bool DeleteWasArrayForm) { 3365 assert(Field != nullptr && "Analysis requires a valid class member.")((void)0); 3366 this->Field = Field; 3367 IsArrayForm = DeleteWasArrayForm; 3368 const CXXRecordDecl *RD = cast<const CXXRecordDecl>(Field->getParent()); 3369 for (const auto *CD : RD->ctors()) { 3370 if (hasMatchingNewInCtor(CD)) 3371 return NoMismatch; 3372 } 3373 if (HasUndefinedConstructors) 3374 return EndOfTU ? NoMismatch : AnalyzeLater; 3375 if (!NewExprs.empty()) 3376 return MemberInitMismatches; 3377 return Field->hasInClassInitializer() ? analyzeInClassInitializer() 3378 : NoMismatch; 3379} 3380 3381MismatchingNewDeleteDetector::MismatchResult 3382MismatchingNewDeleteDetector::analyzeMemberExpr(const MemberExpr *ME) { 3383 assert(ME != nullptr && "Expected a member expression")((void)0); 3384 if (FieldDecl *F = dyn_cast<FieldDecl>(ME->getMemberDecl())) 3385 return analyzeField(F, IsArrayForm); 3386 return NoMismatch; 3387} 3388 3389bool MismatchingNewDeleteDetector::hasMatchingVarInit(const DeclRefExpr *D) { 3390 const CXXNewExpr *NE = nullptr; 3391 if (const VarDecl *VD = dyn_cast<const VarDecl>(D->getDecl())) { 3392 if (VD->hasInit() && (NE = getNewExprFromInitListOrExpr(VD->getInit())) && 3393 NE->isArray() != IsArrayForm) { 3394 NewExprs.push_back(NE); 3395 } 3396 } 3397 return NewExprs.empty(); 3398} 3399 3400static void 3401DiagnoseMismatchedNewDelete(Sema &SemaRef, SourceLocation DeleteLoc, 3402 const MismatchingNewDeleteDetector &Detector) { 3403 SourceLocation EndOfDelete = SemaRef.getLocForEndOfToken(DeleteLoc); 3404 FixItHint H; 3405 if (!Detector.IsArrayForm) 3406 H = FixItHint::CreateInsertion(EndOfDelete, "[]"); 3407 else { 3408 SourceLocation RSquare = Lexer::findLocationAfterToken( 3409 DeleteLoc, tok::l_square, SemaRef.getSourceManager(), 3410 SemaRef.getLangOpts(), true); 3411 if (RSquare.isValid()) 3412 H = FixItHint::CreateRemoval(SourceRange(EndOfDelete, RSquare)); 3413 } 3414 SemaRef.Diag(DeleteLoc, diag::warn_mismatched_delete_new) 3415 << Detector.IsArrayForm << H; 3416 3417 for (const auto *NE : Detector.NewExprs) 3418 SemaRef.Diag(NE->getExprLoc(), diag::note_allocated_here) 3419 << Detector.IsArrayForm; 3420} 3421 3422void Sema::AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE) { 3423 if (Diags.isIgnored(diag::warn_mismatched_delete_new, SourceLocation())) 3424 return; 3425 MismatchingNewDeleteDetector Detector(/*EndOfTU=*/false); 3426 switch (Detector.analyzeDeleteExpr(DE)) { 3427 case MismatchingNewDeleteDetector::VarInitMismatches: 3428 case MismatchingNewDeleteDetector::MemberInitMismatches: { 3429 DiagnoseMismatchedNewDelete(*this, DE->getBeginLoc(), Detector); 3430 break; 3431 } 3432 case MismatchingNewDeleteDetector::AnalyzeLater: { 3433 DeleteExprs[Detector.Field].push_back( 3434 std::make_pair(DE->getBeginLoc(), DE->isArrayForm())); 3435 break; 3436 } 3437 case MismatchingNewDeleteDetector::NoMismatch: 3438 break; 3439 } 3440} 3441 3442void Sema::AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc, 3443 bool DeleteWasArrayForm) { 3444 MismatchingNewDeleteDetector Detector(/*EndOfTU=*/true); 3445 switch (Detector.analyzeField(Field, DeleteWasArrayForm)) { 3446 case MismatchingNewDeleteDetector::VarInitMismatches: 3447 llvm_unreachable("This analysis should have been done for class members.")__builtin_unreachable(); 3448 case MismatchingNewDeleteDetector::AnalyzeLater: 3449 llvm_unreachable("Analysis cannot be postponed any point beyond end of "__builtin_unreachable() 3450 "translation unit.")__builtin_unreachable(); 3451 case MismatchingNewDeleteDetector::MemberInitMismatches: 3452 DiagnoseMismatchedNewDelete(*this, DeleteLoc, Detector); 3453 break; 3454 case MismatchingNewDeleteDetector::NoMismatch: 3455 break; 3456 } 3457} 3458 3459/// ActOnCXXDelete - Parsed a C++ 'delete' expression (C++ 5.3.5), as in: 3460/// @code ::delete ptr; @endcode 3461/// or 3462/// @code delete [] ptr; @endcode 3463ExprResult 3464Sema::ActOnCXXDelete(SourceLocation StartLoc, bool UseGlobal, 3465 bool ArrayForm, Expr *ExE) { 3466 // C++ [expr.delete]p1: 3467 // The operand shall have a pointer type, or a class type having a single 3468 // non-explicit conversion function to a pointer type. The result has type 3469 // void. 3470 // 3471 // DR599 amends "pointer type" to "pointer to object type" in both cases. 3472 3473 ExprResult Ex = ExE; 3474 FunctionDecl *OperatorDelete = nullptr; 3475 bool ArrayFormAsWritten = ArrayForm; 3476 bool UsualArrayDeleteWantsSize = false; 3477 3478 if (!Ex.get()->isTypeDependent()) { 3479 // Perform lvalue-to-rvalue cast, if needed. 3480 Ex = DefaultLvalueConversion(Ex.get()); 3481 if (Ex.isInvalid()) 3482 return ExprError(); 3483 3484 QualType Type = Ex.get()->getType(); 3485 3486 class DeleteConverter : public ContextualImplicitConverter { 3487 public: 3488 DeleteConverter() : ContextualImplicitConverter(false, true) {} 3489 3490 bool match(QualType ConvType) override { 3491 // FIXME: If we have an operator T* and an operator void*, we must pick 3492 // the operator T*. 3493 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 3494 if (ConvPtrType->getPointeeType()->isIncompleteOrObjectType()) 3495 return true; 3496 return false; 3497 } 3498 3499 SemaDiagnosticBuilder diagnoseNoMatch(Sema &S, SourceLocation Loc, 3500 QualType T) override { 3501 return S.Diag(Loc, diag::err_delete_operand) << T; 3502 } 3503 3504 SemaDiagnosticBuilder diagnoseIncomplete(Sema &S, SourceLocation Loc, 3505 QualType T) override { 3506 return S.Diag(Loc, diag::err_delete_incomplete_class_type) << T; 3507 } 3508 3509 SemaDiagnosticBuilder diagnoseExplicitConv(Sema &S, SourceLocation Loc, 3510 QualType T, 3511 QualType ConvTy) override { 3512 return S.Diag(Loc, diag::err_delete_explicit_conversion) << T << ConvTy; 3513 } 3514 3515 SemaDiagnosticBuilder noteExplicitConv(Sema &S, CXXConversionDecl *Conv, 3516 QualType ConvTy) override { 3517 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 3518 << ConvTy; 3519 } 3520 3521 SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, 3522 QualType T) override { 3523 return S.Diag(Loc, diag::err_ambiguous_delete_operand) << T; 3524 } 3525 3526 SemaDiagnosticBuilder noteAmbiguous(Sema &S, CXXConversionDecl *Conv, 3527 QualType ConvTy) override { 3528 return S.Diag(Conv->getLocation(), diag::note_delete_conversion) 3529 << ConvTy; 3530 } 3531 3532 SemaDiagnosticBuilder diagnoseConversion(Sema &S, SourceLocation Loc, 3533 QualType T, 3534 QualType ConvTy) override { 3535 llvm_unreachable("conversion functions are permitted")__builtin_unreachable(); 3536 } 3537 } Converter; 3538 3539 Ex = PerformContextualImplicitConversion(StartLoc, Ex.get(), Converter); 3540 if (Ex.isInvalid()) 3541 return ExprError(); 3542 Type = Ex.get()->getType(); 3543 if (!Converter.match(Type)) 3544 // FIXME: PerformContextualImplicitConversion should return ExprError 3545 // itself in this case. 3546 return ExprError(); 3547 3548 QualType Pointee = Type->castAs<PointerType>()->getPointeeType(); 3549 QualType PointeeElem = Context.getBaseElementType(Pointee); 3550 3551 if (Pointee.getAddressSpace() != LangAS::Default && 3552 !getLangOpts().OpenCLCPlusPlus) 3553 return Diag(Ex.get()->getBeginLoc(), 3554 diag::err_address_space_qualified_delete) 3555 << Pointee.getUnqualifiedType() 3556 << Pointee.getQualifiers().getAddressSpaceAttributePrintValue(); 3557 3558 CXXRecordDecl *PointeeRD = nullptr; 3559 if (Pointee->isVoidType() && !isSFINAEContext()) { 3560 // The C++ standard bans deleting a pointer to a non-object type, which 3561 // effectively bans deletion of "void*". However, most compilers support 3562 // this, so we treat it as a warning unless we're in a SFINAE context. 3563 Diag(StartLoc, diag::ext_delete_void_ptr_operand) 3564 << Type << Ex.get()->getSourceRange(); 3565 } else if (Pointee->isFunctionType() || Pointee->isVoidType() || 3566 Pointee->isSizelessType()) { 3567 return ExprError(Diag(StartLoc, diag::err_delete_operand) 3568 << Type << Ex.get()->getSourceRange()); 3569 } else if (!Pointee->isDependentType()) { 3570 // FIXME: This can result in errors if the definition was imported from a 3571 // module but is hidden. 3572 if (!RequireCompleteType(StartLoc, Pointee, 3573 diag::warn_delete_incomplete, Ex.get())) { 3574 if (const RecordType *RT = PointeeElem->getAs<RecordType>()) 3575 PointeeRD = cast<CXXRecordDecl>(RT->getDecl()); 3576 } 3577 } 3578 3579 if (Pointee->isArrayType() && !ArrayForm) { 3580 Diag(StartLoc, diag::warn_delete_array_type) 3581 << Type << Ex.get()->getSourceRange() 3582 << FixItHint::CreateInsertion(getLocForEndOfToken(StartLoc), "[]"); 3583 ArrayForm = true; 3584 } 3585 3586 DeclarationName DeleteName = Context.DeclarationNames.getCXXOperatorName( 3587 ArrayForm ? OO_Array_Delete : OO_Delete); 3588 3589 if (PointeeRD) { 3590 if (!UseGlobal && 3591 FindDeallocationFunction(StartLoc, PointeeRD, DeleteName, 3592 OperatorDelete)) 3593 return ExprError(); 3594 3595 // If we're allocating an array of records, check whether the 3596 // usual operator delete[] has a size_t parameter. 3597 if (ArrayForm) { 3598 // If the user specifically asked to use the global allocator, 3599 // we'll need to do the lookup into the class. 3600 if (UseGlobal) 3601 UsualArrayDeleteWantsSize = 3602 doesUsualArrayDeleteWantSize(*this, StartLoc, PointeeElem); 3603 3604 // Otherwise, the usual operator delete[] should be the 3605 // function we just found. 3606 else if (OperatorDelete && isa<CXXMethodDecl>(OperatorDelete)) 3607 UsualArrayDeleteWantsSize = 3608 UsualDeallocFnInfo(*this, 3609 DeclAccessPair::make(OperatorDelete, AS_public)) 3610 .HasSizeT; 3611 } 3612 3613 if (!PointeeRD->hasIrrelevantDestructor()) 3614 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 3615 MarkFunctionReferenced(StartLoc, 3616 const_cast<CXXDestructorDecl*>(Dtor)); 3617 if (DiagnoseUseOfDecl(Dtor, StartLoc)) 3618 return ExprError(); 3619 } 3620 3621 CheckVirtualDtorCall(PointeeRD->getDestructor(), StartLoc, 3622 /*IsDelete=*/true, /*CallCanBeVirtual=*/true, 3623 /*WarnOnNonAbstractTypes=*/!ArrayForm, 3624 SourceLocation()); 3625 } 3626 3627 if (!OperatorDelete) { 3628 if (getLangOpts().OpenCLCPlusPlus) { 3629 Diag(StartLoc, diag::err_openclcxx_not_supported) << "default delete"; 3630 return ExprError(); 3631 } 3632 3633 bool IsComplete = isCompleteType(StartLoc, Pointee); 3634 bool CanProvideSize = 3635 IsComplete && (!ArrayForm || UsualArrayDeleteWantsSize || 3636 Pointee.isDestructedType()); 3637 bool Overaligned = hasNewExtendedAlignment(*this, Pointee); 3638 3639 // Look for a global declaration. 3640 OperatorDelete = FindUsualDeallocationFunction(StartLoc, CanProvideSize, 3641 Overaligned, DeleteName); 3642 } 3643 3644 MarkFunctionReferenced(StartLoc, OperatorDelete); 3645 3646 // Check access and ambiguity of destructor if we're going to call it. 3647 // Note that this is required even for a virtual delete. 3648 bool IsVirtualDelete = false; 3649 if (PointeeRD) { 3650 if (CXXDestructorDecl *Dtor = LookupDestructor(PointeeRD)) { 3651 CheckDestructorAccess(Ex.get()->getExprLoc(), Dtor, 3652 PDiag(diag::err_access_dtor) << PointeeElem); 3653 IsVirtualDelete = Dtor->isVirtual(); 3654 } 3655 } 3656 3657 DiagnoseUseOfDecl(OperatorDelete, StartLoc); 3658 3659 // Convert the operand to the type of the first parameter of operator 3660 // delete. This is only necessary if we selected a destroying operator 3661 // delete that we are going to call (non-virtually); converting to void* 3662 // is trivial and left to AST consumers to handle. 3663 QualType ParamType = OperatorDelete->getParamDecl(0)->getType(); 3664 if (!IsVirtualDelete && !ParamType->getPointeeType()->isVoidType()) { 3665 Qualifiers Qs = Pointee.getQualifiers(); 3666 if (Qs.hasCVRQualifiers()) { 3667 // Qualifiers are irrelevant to this conversion; we're only looking 3668 // for access and ambiguity. 3669 Qs.removeCVRQualifiers(); 3670 QualType Unqual = Context.getPointerType( 3671 Context.getQualifiedType(Pointee.getUnqualifiedType(), Qs)); 3672 Ex = ImpCastExprToType(Ex.get(), Unqual, CK_NoOp); 3673 } 3674 Ex = PerformImplicitConversion(Ex.get(), ParamType, AA_Passing); 3675 if (Ex.isInvalid()) 3676 return ExprError(); 3677 } 3678 } 3679 3680 CXXDeleteExpr *Result = new (Context) CXXDeleteExpr( 3681 Context.VoidTy, UseGlobal, ArrayForm, ArrayFormAsWritten, 3682 UsualArrayDeleteWantsSize, OperatorDelete, Ex.get(), StartLoc); 3683 AnalyzeDeleteExprMismatch(Result); 3684 return Result; 3685} 3686 3687static bool resolveBuiltinNewDeleteOverload(Sema &S, CallExpr *TheCall, 3688 bool IsDelete, 3689 FunctionDecl *&Operator) { 3690 3691 DeclarationName NewName = S.Context.DeclarationNames.getCXXOperatorName( 3692 IsDelete ? OO_Delete : OO_New); 3693 3694 LookupResult R(S, NewName, TheCall->getBeginLoc(), Sema::LookupOrdinaryName); 3695 S.LookupQualifiedName(R, S.Context.getTranslationUnitDecl()); 3696 assert(!R.empty() && "implicitly declared allocation functions not found")((void)0); 3697 assert(!R.isAmbiguous() && "global allocation functions are ambiguous")((void)0); 3698 3699 // We do our own custom access checks below. 3700 R.suppressDiagnostics(); 3701 3702 SmallVector<Expr *, 8> Args(TheCall->arg_begin(), TheCall->arg_end()); 3703 OverloadCandidateSet Candidates(R.getNameLoc(), 3704 OverloadCandidateSet::CSK_Normal); 3705 for (LookupResult::iterator FnOvl = R.begin(), FnOvlEnd = R.end(); 3706 FnOvl != FnOvlEnd; ++FnOvl) { 3707 // Even member operator new/delete are implicitly treated as 3708 // static, so don't use AddMemberCandidate. 3709 NamedDecl *D = (*FnOvl)->getUnderlyingDecl(); 3710 3711 if (FunctionTemplateDecl *FnTemplate = dyn_cast<FunctionTemplateDecl>(D)) { 3712 S.AddTemplateOverloadCandidate(FnTemplate, FnOvl.getPair(), 3713 /*ExplicitTemplateArgs=*/nullptr, Args, 3714 Candidates, 3715 /*SuppressUserConversions=*/false); 3716 continue; 3717 } 3718 3719 FunctionDecl *Fn = cast<FunctionDecl>(D); 3720 S.AddOverloadCandidate(Fn, FnOvl.getPair(), Args, Candidates, 3721 /*SuppressUserConversions=*/false); 3722 } 3723 3724 SourceRange Range = TheCall->getSourceRange(); 3725 3726 // Do the resolution. 3727 OverloadCandidateSet::iterator Best; 3728 switch (Candidates.BestViableFunction(S, R.getNameLoc(), Best)) { 3729 case OR_Success: { 3730 // Got one! 3731 FunctionDecl *FnDecl = Best->Function; 3732 assert(R.getNamingClass() == nullptr &&((void)0) 3733 "class members should not be considered")((void)0); 3734 3735 if (!FnDecl->isReplaceableGlobalAllocationFunction()) { 3736 S.Diag(R.getNameLoc(), diag::err_builtin_operator_new_delete_not_usual) 3737 << (IsDelete ? 1 : 0) << Range; 3738 S.Diag(FnDecl->getLocation(), diag::note_non_usual_function_declared_here) 3739 << R.getLookupName() << FnDecl->getSourceRange(); 3740 return true; 3741 } 3742 3743 Operator = FnDecl; 3744 return false; 3745 } 3746 3747 case OR_No_Viable_Function: 3748 Candidates.NoteCandidates( 3749 PartialDiagnosticAt(R.getNameLoc(), 3750 S.PDiag(diag::err_ovl_no_viable_function_in_call) 3751 << R.getLookupName() << Range), 3752 S, OCD_AllCandidates, Args); 3753 return true; 3754 3755 case OR_Ambiguous: 3756 Candidates.NoteCandidates( 3757 PartialDiagnosticAt(R.getNameLoc(), 3758 S.PDiag(diag::err_ovl_ambiguous_call) 3759 << R.getLookupName() << Range), 3760 S, OCD_AmbiguousCandidates, Args); 3761 return true; 3762 3763 case OR_Deleted: { 3764 Candidates.NoteCandidates( 3765 PartialDiagnosticAt(R.getNameLoc(), S.PDiag(diag::err_ovl_deleted_call) 3766 << R.getLookupName() << Range), 3767 S, OCD_AllCandidates, Args); 3768 return true; 3769 } 3770 } 3771 llvm_unreachable("Unreachable, bad result from BestViableFunction")__builtin_unreachable(); 3772} 3773 3774ExprResult 3775Sema::SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult, 3776 bool IsDelete) { 3777 CallExpr *TheCall = cast<CallExpr>(TheCallResult.get()); 3778 if (!getLangOpts().CPlusPlus) { 3779 Diag(TheCall->getExprLoc(), diag::err_builtin_requires_language) 3780 << (IsDelete ? "__builtin_operator_delete" : "__builtin_operator_new") 3781 << "C++"; 3782 return ExprError(); 3783 } 3784 // CodeGen assumes it can find the global new and delete to call, 3785 // so ensure that they are declared. 3786 DeclareGlobalNewDelete(); 3787 3788 FunctionDecl *OperatorNewOrDelete = nullptr; 3789 if (resolveBuiltinNewDeleteOverload(*this, TheCall, IsDelete, 3790 OperatorNewOrDelete)) 3791 return ExprError(); 3792 assert(OperatorNewOrDelete && "should be found")((void)0); 3793 3794 DiagnoseUseOfDecl(OperatorNewOrDelete, TheCall->getExprLoc()); 3795 MarkFunctionReferenced(TheCall->getExprLoc(), OperatorNewOrDelete); 3796 3797 TheCall->setType(OperatorNewOrDelete->getReturnType()); 3798 for (unsigned i = 0; i != TheCall->getNumArgs(); ++i) { 3799 QualType ParamTy = OperatorNewOrDelete->getParamDecl(i)->getType(); 3800 InitializedEntity Entity = 3801 InitializedEntity::InitializeParameter(Context, ParamTy, false); 3802 ExprResult Arg = PerformCopyInitialization( 3803 Entity, TheCall->getArg(i)->getBeginLoc(), TheCall->getArg(i)); 3804 if (Arg.isInvalid()) 3805 return ExprError(); 3806 TheCall->setArg(i, Arg.get()); 3807 } 3808 auto Callee = dyn_cast<ImplicitCastExpr>(TheCall->getCallee()); 3809 assert(Callee && Callee->getCastKind() == CK_BuiltinFnToFnPtr &&((void)0) 3810 "Callee expected to be implicit cast to a builtin function pointer")((void)0); 3811 Callee->setType(OperatorNewOrDelete->getType()); 3812 3813 return TheCallResult; 3814} 3815 3816void Sema::CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc, 3817 bool IsDelete, bool CallCanBeVirtual, 3818 bool WarnOnNonAbstractTypes, 3819 SourceLocation DtorLoc) { 3820 if (!dtor || dtor->isVirtual() || !CallCanBeVirtual || isUnevaluatedContext()) 3821 return; 3822 3823 // C++ [expr.delete]p3: 3824 // In the first alternative (delete object), if the static type of the 3825 // object to be deleted is different from its dynamic type, the static 3826 // type shall be a base class of the dynamic type of the object to be 3827 // deleted and the static type shall have a virtual destructor or the 3828 // behavior is undefined. 3829 // 3830 const CXXRecordDecl *PointeeRD = dtor->getParent(); 3831 // Note: a final class cannot be derived from, no issue there 3832 if (!PointeeRD->isPolymorphic() || PointeeRD->hasAttr<FinalAttr>()) 3833 return; 3834 3835 // If the superclass is in a system header, there's nothing that can be done. 3836 // The `delete` (where we emit the warning) can be in a system header, 3837 // what matters for this warning is where the deleted type is defined. 3838 if (getSourceManager().isInSystemHeader(PointeeRD->getLocation())) 3839 return; 3840 3841 QualType ClassType = dtor->getThisType()->getPointeeType(); 3842 if (PointeeRD->isAbstract()) { 3843 // If the class is abstract, we warn by default, because we're 3844 // sure the code has undefined behavior. 3845 Diag(Loc, diag::warn_delete_abstract_non_virtual_dtor) << (IsDelete ? 0 : 1) 3846 << ClassType; 3847 } else if (WarnOnNonAbstractTypes) { 3848 // Otherwise, if this is not an array delete, it's a bit suspect, 3849 // but not necessarily wrong. 3850 Diag(Loc, diag::warn_delete_non_virtual_dtor) << (IsDelete ? 0 : 1) 3851 << ClassType; 3852 } 3853 if (!IsDelete) { 3854 std::string TypeStr; 3855 ClassType.getAsStringInternal(TypeStr, getPrintingPolicy()); 3856 Diag(DtorLoc, diag::note_delete_non_virtual) 3857 << FixItHint::CreateInsertion(DtorLoc, TypeStr + "::"); 3858 } 3859} 3860 3861Sema::ConditionResult Sema::ActOnConditionVariable(Decl *ConditionVar, 3862 SourceLocation StmtLoc, 3863 ConditionKind CK) { 3864 ExprResult E = 3865 CheckConditionVariable(cast<VarDecl>(ConditionVar), StmtLoc, CK); 3866 if (E.isInvalid()) 3867 return ConditionError(); 3868 return ConditionResult(*this, ConditionVar, MakeFullExpr(E.get(), StmtLoc), 3869 CK == ConditionKind::ConstexprIf); 3870} 3871 3872/// Check the use of the given variable as a C++ condition in an if, 3873/// while, do-while, or switch statement. 3874ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, 3875 SourceLocation StmtLoc, 3876 ConditionKind CK) { 3877 if (ConditionVar->isInvalidDecl()) 3878 return ExprError(); 3879 3880 QualType T = ConditionVar->getType(); 3881 3882 // C++ [stmt.select]p2: 3883 // The declarator shall not specify a function or an array. 3884 if (T->isFunctionType()) 3885 return ExprError(Diag(ConditionVar->getLocation(), 3886 diag::err_invalid_use_of_function_type) 3887 << ConditionVar->getSourceRange()); 3888 else if (T->isArrayType()) 3889 return ExprError(Diag(ConditionVar->getLocation(), 3890 diag::err_invalid_use_of_array_type) 3891 << ConditionVar->getSourceRange()); 3892 3893 ExprResult Condition = BuildDeclRefExpr( 3894 ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue, 3895 ConditionVar->getLocation()); 3896 3897 switch (CK) { 3898 case ConditionKind::Boolean: 3899 return CheckBooleanCondition(StmtLoc, Condition.get()); 3900 3901 case ConditionKind::ConstexprIf: 3902 return CheckBooleanCondition(StmtLoc, Condition.get(), true); 3903 3904 case ConditionKind::Switch: 3905 return CheckSwitchCondition(StmtLoc, Condition.get()); 3906 } 3907 3908 llvm_unreachable("unexpected condition kind")__builtin_unreachable(); 3909} 3910 3911/// CheckCXXBooleanCondition - Returns true if a conversion to bool is invalid. 3912ExprResult Sema::CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr) { 3913 // C++11 6.4p4: 3914 // The value of a condition that is an initialized declaration in a statement 3915 // other than a switch statement is the value of the declared variable 3916 // implicitly converted to type bool. If that conversion is ill-formed, the 3917 // program is ill-formed. 3918 // The value of a condition that is an expression is the value of the 3919 // expression, implicitly converted to bool. 3920 // 3921 // C++2b 8.5.2p2 3922 // If the if statement is of the form if constexpr, the value of the condition 3923 // is contextually converted to bool and the converted expression shall be 3924 // a constant expression. 3925 // 3926 3927 ExprResult E = PerformContextuallyConvertToBool(CondExpr); 3928 if (!IsConstexpr || E.isInvalid() || E.get()->isValueDependent()) 3929 return E; 3930 3931 // FIXME: Return this value to the caller so they don't need to recompute it. 3932 llvm::APSInt Cond; 3933 E = VerifyIntegerConstantExpression( 3934 E.get(), &Cond, 3935 diag::err_constexpr_if_condition_expression_is_not_constant); 3936 return E; 3937} 3938 3939/// Helper function to determine whether this is the (deprecated) C++ 3940/// conversion from a string literal to a pointer to non-const char or 3941/// non-const wchar_t (for narrow and wide string literals, 3942/// respectively). 3943bool 3944Sema::IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType) { 3945 // Look inside the implicit cast, if it exists. 3946 if (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(From)) 3947 From = Cast->getSubExpr(); 3948 3949 // A string literal (2.13.4) that is not a wide string literal can 3950 // be converted to an rvalue of type "pointer to char"; a wide 3951 // string literal can be converted to an rvalue of type "pointer 3952 // to wchar_t" (C++ 4.2p2). 3953 if (StringLiteral *StrLit = dyn_cast<StringLiteral>(From->IgnoreParens())) 3954 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) 3955 if (const BuiltinType *ToPointeeType 3956 = ToPtrType->getPointeeType()->getAs<BuiltinType>()) { 3957 // This conversion is considered only when there is an 3958 // explicit appropriate pointer target type (C++ 4.2p2). 3959 if (!ToPtrType->getPointeeType().hasQualifiers()) { 3960 switch (StrLit->getKind()) { 3961 case StringLiteral::UTF8: 3962 case StringLiteral::UTF16: 3963 case StringLiteral::UTF32: 3964 // We don't allow UTF literals to be implicitly converted 3965 break; 3966 case StringLiteral::Ascii: 3967 return (ToPointeeType->getKind() == BuiltinType::Char_U || 3968 ToPointeeType->getKind() == BuiltinType::Char_S); 3969 case StringLiteral::Wide: 3970 return Context.typesAreCompatible(Context.getWideCharType(), 3971 QualType(ToPointeeType, 0)); 3972 } 3973 } 3974 } 3975 3976 return false; 3977} 3978 3979static ExprResult BuildCXXCastArgument(Sema &S, 3980 SourceLocation CastLoc, 3981 QualType Ty, 3982 CastKind Kind, 3983 CXXMethodDecl *Method, 3984 DeclAccessPair FoundDecl, 3985 bool HadMultipleCandidates, 3986 Expr *From) { 3987 switch (Kind) { 3988 default: llvm_unreachable("Unhandled cast kind!")__builtin_unreachable(); 3989 case CK_ConstructorConversion: { 3990 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Method); 3991 SmallVector<Expr*, 8> ConstructorArgs; 3992 3993 if (S.RequireNonAbstractType(CastLoc, Ty, 3994 diag::err_allocation_of_abstract_type)) 3995 return ExprError(); 3996 3997 if (S.CompleteConstructorCall(Constructor, Ty, From, CastLoc, 3998 ConstructorArgs)) 3999 return ExprError(); 4000 4001 S.CheckConstructorAccess(CastLoc, Constructor, FoundDecl, 4002 InitializedEntity::InitializeTemporary(Ty)); 4003 if (S.DiagnoseUseOfDecl(Method, CastLoc)) 4004 return ExprError(); 4005 4006 ExprResult Result = S.BuildCXXConstructExpr( 4007 CastLoc, Ty, FoundDecl, cast<CXXConstructorDecl>(Method), 4008 ConstructorArgs, HadMultipleCandidates, 4009 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 4010 CXXConstructExpr::CK_Complete, SourceRange()); 4011 if (Result.isInvalid()) 4012 return ExprError(); 4013 4014 return S.MaybeBindToTemporary(Result.getAs<Expr>()); 4015 } 4016 4017 case CK_UserDefinedConversion: { 4018 assert(!From->getType()->isPointerType() && "Arg can't have pointer type!")((void)0); 4019 4020 S.CheckMemberOperatorAccess(CastLoc, From, /*arg*/ nullptr, FoundDecl); 4021 if (S.DiagnoseUseOfDecl(Method, CastLoc)) 4022 return ExprError(); 4023 4024 // Create an implicit call expr that calls it. 4025 CXXConversionDecl *Conv = cast<CXXConversionDecl>(Method); 4026 ExprResult Result = S.BuildCXXMemberCallExpr(From, FoundDecl, Conv, 4027 HadMultipleCandidates); 4028 if (Result.isInvalid()) 4029 return ExprError(); 4030 // Record usage of conversion in an implicit cast. 4031 Result = ImplicitCastExpr::Create(S.Context, Result.get()->getType(), 4032 CK_UserDefinedConversion, Result.get(), 4033 nullptr, Result.get()->getValueKind(), 4034 S.CurFPFeatureOverrides()); 4035 4036 return S.MaybeBindToTemporary(Result.get()); 4037 } 4038 } 4039} 4040 4041/// PerformImplicitConversion - Perform an implicit conversion of the 4042/// expression From to the type ToType using the pre-computed implicit 4043/// conversion sequence ICS. Returns the converted 4044/// expression. Action is the kind of conversion we're performing, 4045/// used in the error message. 4046ExprResult 4047Sema::PerformImplicitConversion(Expr *From, QualType ToType, 4048 const ImplicitConversionSequence &ICS, 4049 AssignmentAction Action, 4050 CheckedConversionKind CCK) { 4051 // C++ [over.match.oper]p7: [...] operands of class type are converted [...] 4052 if (CCK == CCK_ForBuiltinOverloadedOp && !From->getType()->isRecordType()) 4053 return From; 4054 4055 switch (ICS.getKind()) { 4056 case ImplicitConversionSequence::StandardConversion: { 4057 ExprResult Res = PerformImplicitConversion(From, ToType, ICS.Standard, 4058 Action, CCK); 4059 if (Res.isInvalid()) 4060 return ExprError(); 4061 From = Res.get(); 4062 break; 4063 } 4064 4065 case ImplicitConversionSequence::UserDefinedConversion: { 4066 4067 FunctionDecl *FD = ICS.UserDefined.ConversionFunction; 4068 CastKind CastKind; 4069 QualType BeforeToType; 4070 assert(FD && "no conversion function for user-defined conversion seq")((void)0); 4071 if (const CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(FD)) { 4072 CastKind = CK_UserDefinedConversion; 4073 4074 // If the user-defined conversion is specified by a conversion function, 4075 // the initial standard conversion sequence converts the source type to 4076 // the implicit object parameter of the conversion function. 4077 BeforeToType = Context.getTagDeclType(Conv->getParent()); 4078 } else { 4079 const CXXConstructorDecl *Ctor = cast<CXXConstructorDecl>(FD); 4080 CastKind = CK_ConstructorConversion; 4081 // Do no conversion if dealing with ... for the first conversion. 4082 if (!ICS.UserDefined.EllipsisConversion) { 4083 // If the user-defined conversion is specified by a constructor, the 4084 // initial standard conversion sequence converts the source type to 4085 // the type required by the argument of the constructor 4086 BeforeToType = Ctor->getParamDecl(0)->getType().getNonReferenceType(); 4087 } 4088 } 4089 // Watch out for ellipsis conversion. 4090 if (!ICS.UserDefined.EllipsisConversion) { 4091 ExprResult Res = 4092 PerformImplicitConversion(From, BeforeToType, 4093 ICS.UserDefined.Before, AA_Converting, 4094 CCK); 4095 if (Res.isInvalid()) 4096 return ExprError(); 4097 From = Res.get(); 4098 } 4099 4100 ExprResult CastArg = BuildCXXCastArgument( 4101 *this, From->getBeginLoc(), ToType.getNonReferenceType(), CastKind, 4102 cast<CXXMethodDecl>(FD), ICS.UserDefined.FoundConversionFunction, 4103 ICS.UserDefined.HadMultipleCandidates, From); 4104 4105 if (CastArg.isInvalid()) 4106 return ExprError(); 4107 4108 From = CastArg.get(); 4109 4110 // C++ [over.match.oper]p7: 4111 // [...] the second standard conversion sequence of a user-defined 4112 // conversion sequence is not applied. 4113 if (CCK == CCK_ForBuiltinOverloadedOp) 4114 return From; 4115 4116 return PerformImplicitConversion(From, ToType, ICS.UserDefined.After, 4117 AA_Converting, CCK); 4118 } 4119 4120 case ImplicitConversionSequence::AmbiguousConversion: 4121 ICS.DiagnoseAmbiguousConversion(*this, From->getExprLoc(), 4122 PDiag(diag::err_typecheck_ambiguous_condition) 4123 << From->getSourceRange()); 4124 return ExprError(); 4125 4126 case ImplicitConversionSequence::EllipsisConversion: 4127 llvm_unreachable("Cannot perform an ellipsis conversion")__builtin_unreachable(); 4128 4129 case ImplicitConversionSequence::BadConversion: 4130 Sema::AssignConvertType ConvTy = 4131 CheckAssignmentConstraints(From->getExprLoc(), ToType, From->getType()); 4132 bool Diagnosed = DiagnoseAssignmentResult( 4133 ConvTy == Compatible ? Incompatible : ConvTy, From->getExprLoc(), 4134 ToType, From->getType(), From, Action); 4135 assert(Diagnosed && "failed to diagnose bad conversion")((void)0); (void)Diagnosed; 4136 return ExprError(); 4137 } 4138 4139 // Everything went well. 4140 return From; 4141} 4142 4143/// PerformImplicitConversion - Perform an implicit conversion of the 4144/// expression From to the type ToType by following the standard 4145/// conversion sequence SCS. Returns the converted 4146/// expression. Flavor is the context in which we're performing this 4147/// conversion, for use in error messages. 4148ExprResult 4149Sema::PerformImplicitConversion(Expr *From, QualType ToType, 4150 const StandardConversionSequence& SCS, 4151 AssignmentAction Action, 4152 CheckedConversionKind CCK) { 4153 bool CStyle = (CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast); 4154 4155 // Overall FIXME: we are recomputing too many types here and doing far too 4156 // much extra work. What this means is that we need to keep track of more 4157 // information that is computed when we try the implicit conversion initially, 4158 // so that we don't need to recompute anything here. 4159 QualType FromType = From->getType(); 4160 4161 if (SCS.CopyConstructor) { 4162 // FIXME: When can ToType be a reference type? 4163 assert(!ToType->isReferenceType())((void)0); 4164 if (SCS.Second == ICK_Derived_To_Base) { 4165 SmallVector<Expr*, 8> ConstructorArgs; 4166 if (CompleteConstructorCall( 4167 cast<CXXConstructorDecl>(SCS.CopyConstructor), ToType, From, 4168 /*FIXME:ConstructLoc*/ SourceLocation(), ConstructorArgs)) 4169 return ExprError(); 4170 return BuildCXXConstructExpr( 4171 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, 4172 SCS.FoundCopyConstructor, SCS.CopyConstructor, 4173 ConstructorArgs, /*HadMultipleCandidates*/ false, 4174 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 4175 CXXConstructExpr::CK_Complete, SourceRange()); 4176 } 4177 return BuildCXXConstructExpr( 4178 /*FIXME:ConstructLoc*/ SourceLocation(), ToType, 4179 SCS.FoundCopyConstructor, SCS.CopyConstructor, 4180 From, /*HadMultipleCandidates*/ false, 4181 /*ListInit*/ false, /*StdInitListInit*/ false, /*ZeroInit*/ false, 4182 CXXConstructExpr::CK_Complete, SourceRange()); 4183 } 4184 4185 // Resolve overloaded function references. 4186 if (Context.hasSameType(FromType, Context.OverloadTy)) { 4187 DeclAccessPair Found; 4188 FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(From, ToType, 4189 true, Found); 4190 if (!Fn) 4191 return ExprError(); 4192 4193 if (DiagnoseUseOfDecl(Fn, From->getBeginLoc())) 4194 return ExprError(); 4195 4196 From = FixOverloadedFunctionReference(From, Found, Fn); 4197 FromType = From->getType(); 4198 } 4199 4200 // If we're converting to an atomic type, first convert to the corresponding 4201 // non-atomic type. 4202 QualType ToAtomicType; 4203 if (const AtomicType *ToAtomic = ToType->getAs<AtomicType>()) { 4204 ToAtomicType = ToType; 4205 ToType = ToAtomic->getValueType(); 4206 } 4207 4208 QualType InitialFromType = FromType; 4209 // Perform the first implicit conversion. 4210 switch (SCS.First) { 4211 case ICK_Identity: 4212 if (const AtomicType *FromAtomic = FromType->getAs<AtomicType>()) { 4213 FromType = FromAtomic->getValueType().getUnqualifiedType(); 4214 From = ImplicitCastExpr::Create(Context, FromType, CK_AtomicToNonAtomic, 4215 From, /*BasePath=*/nullptr, VK_PRValue, 4216 FPOptionsOverride()); 4217 } 4218 break; 4219 4220 case ICK_Lvalue_To_Rvalue: { 4221 assert(From->getObjectKind() != OK_ObjCProperty)((void)0); 4222 ExprResult FromRes = DefaultLvalueConversion(From); 4223 if (FromRes.isInvalid()) 4224 return ExprError(); 4225 4226 From = FromRes.get(); 4227 FromType = From->getType(); 4228 break; 4229 } 4230 4231 case ICK_Array_To_Pointer: 4232 FromType = Context.getArrayDecayedType(FromType); 4233 From = ImpCastExprToType(From, FromType, CK_ArrayToPointerDecay, VK_PRValue, 4234 /*BasePath=*/nullptr, CCK) 4235 .get(); 4236 break; 4237 4238 case ICK_Function_To_Pointer: 4239 FromType = Context.getPointerType(FromType); 4240 From = ImpCastExprToType(From, FromType, CK_FunctionToPointerDecay, 4241 VK_PRValue, /*BasePath=*/nullptr, CCK) 4242 .get(); 4243 break; 4244 4245 default: 4246 llvm_unreachable("Improper first standard conversion")__builtin_unreachable(); 4247 } 4248 4249 // Perform the second implicit conversion 4250 switch (SCS.Second) { 4251 case ICK_Identity: 4252 // C++ [except.spec]p5: 4253 // [For] assignment to and initialization of pointers to functions, 4254 // pointers to member functions, and references to functions: the 4255 // target entity shall allow at least the exceptions allowed by the 4256 // source value in the assignment or initialization. 4257 switch (Action) { 4258 case AA_Assigning: 4259 case AA_Initializing: 4260 // Note, function argument passing and returning are initialization. 4261 case AA_Passing: 4262 case AA_Returning: 4263 case AA_Sending: 4264 case AA_Passing_CFAudited: 4265 if (CheckExceptionSpecCompatibility(From, ToType)) 4266 return ExprError(); 4267 break; 4268 4269 case AA_Casting: 4270 case AA_Converting: 4271 // Casts and implicit conversions are not initialization, so are not 4272 // checked for exception specification mismatches. 4273 break; 4274 } 4275 // Nothing else to do. 4276 break; 4277 4278 case ICK_Integral_Promotion: 4279 case ICK_Integral_Conversion: 4280 if (ToType->isBooleanType()) { 4281 assert(FromType->castAs<EnumType>()->getDecl()->isFixed() &&((void)0) 4282 SCS.Second == ICK_Integral_Promotion &&((void)0) 4283 "only enums with fixed underlying type can promote to bool")((void)0); 4284 From = ImpCastExprToType(From, ToType, CK_IntegralToBoolean, VK_PRValue, 4285 /*BasePath=*/nullptr, CCK) 4286 .get(); 4287 } else { 4288 From = ImpCastExprToType(From, ToType, CK_IntegralCast, VK_PRValue, 4289 /*BasePath=*/nullptr, CCK) 4290 .get(); 4291 } 4292 break; 4293 4294 case ICK_Floating_Promotion: 4295 case ICK_Floating_Conversion: 4296 From = ImpCastExprToType(From, ToType, CK_FloatingCast, VK_PRValue, 4297 /*BasePath=*/nullptr, CCK) 4298 .get(); 4299 break; 4300 4301 case ICK_Complex_Promotion: 4302 case ICK_Complex_Conversion: { 4303 QualType FromEl = From->getType()->castAs<ComplexType>()->getElementType(); 4304 QualType ToEl = ToType->castAs<ComplexType>()->getElementType(); 4305 CastKind CK; 4306 if (FromEl->isRealFloatingType()) { 4307 if (ToEl->isRealFloatingType()) 4308 CK = CK_FloatingComplexCast; 4309 else 4310 CK = CK_FloatingComplexToIntegralComplex; 4311 } else if (ToEl->isRealFloatingType()) { 4312 CK = CK_IntegralComplexToFloatingComplex; 4313 } else { 4314 CK = CK_IntegralComplexCast; 4315 } 4316 From = ImpCastExprToType(From, ToType, CK, VK_PRValue, /*BasePath=*/nullptr, 4317 CCK) 4318 .get(); 4319 break; 4320 } 4321 4322 case ICK_Floating_Integral: 4323 if (ToType->isRealFloatingType()) 4324 From = ImpCastExprToType(From, ToType, CK_IntegralToFloating, VK_PRValue, 4325 /*BasePath=*/nullptr, CCK) 4326 .get(); 4327 else 4328 From = ImpCastExprToType(From, ToType, CK_FloatingToIntegral, VK_PRValue, 4329 /*BasePath=*/nullptr, CCK) 4330 .get(); 4331 break; 4332 4333 case ICK_Compatible_Conversion: 4334 From = ImpCastExprToType(From, ToType, CK_NoOp, From->getValueKind(), 4335 /*BasePath=*/nullptr, CCK).get(); 4336 break; 4337 4338 case ICK_Writeback_Conversion: 4339 case ICK_Pointer_Conversion: { 4340 if (SCS.IncompatibleObjC && Action != AA_Casting) { 4341 // Diagnose incompatible Objective-C conversions 4342 if (Action == AA_Initializing || Action == AA_Assigning) 4343 Diag(From->getBeginLoc(), 4344 diag::ext_typecheck_convert_incompatible_pointer) 4345 << ToType << From->getType() << Action << From->getSourceRange() 4346 << 0; 4347 else 4348 Diag(From->getBeginLoc(), 4349 diag::ext_typecheck_convert_incompatible_pointer) 4350 << From->getType() << ToType << Action << From->getSourceRange() 4351 << 0; 4352 4353 if (From->getType()->isObjCObjectPointerType() && 4354 ToType->isObjCObjectPointerType()) 4355 EmitRelatedResultTypeNote(From); 4356 } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() && 4357 !CheckObjCARCUnavailableWeakConversion(ToType, 4358 From->getType())) { 4359 if (Action == AA_Initializing) 4360 Diag(From->getBeginLoc(), diag::err_arc_weak_unavailable_assign); 4361 else 4362 Diag(From->getBeginLoc(), diag::err_arc_convesion_of_weak_unavailable) 4363 << (Action == AA_Casting) << From->getType() << ToType 4364 << From->getSourceRange(); 4365 } 4366 4367 // Defer address space conversion to the third conversion. 4368 QualType FromPteeType = From->getType()->getPointeeType(); 4369 QualType ToPteeType = ToType->getPointeeType(); 4370 QualType NewToType = ToType; 4371 if (!FromPteeType.isNull() && !ToPteeType.isNull() && 4372 FromPteeType.getAddressSpace() != ToPteeType.getAddressSpace()) { 4373 NewToType = Context.removeAddrSpaceQualType(ToPteeType); 4374 NewToType = Context.getAddrSpaceQualType(NewToType, 4375 FromPteeType.getAddressSpace()); 4376 if (ToType->isObjCObjectPointerType()) 4377 NewToType = Context.getObjCObjectPointerType(NewToType); 4378 else if (ToType->isBlockPointerType()) 4379 NewToType = Context.getBlockPointerType(NewToType); 4380 else 4381 NewToType = Context.getPointerType(NewToType); 4382 } 4383 4384 CastKind Kind; 4385 CXXCastPath BasePath; 4386 if (CheckPointerConversion(From, NewToType, Kind, BasePath, CStyle)) 4387 return ExprError(); 4388 4389 // Make sure we extend blocks if necessary. 4390 // FIXME: doing this here is really ugly. 4391 if (Kind == CK_BlockPointerToObjCPointerCast) { 4392 ExprResult E = From; 4393 (void) PrepareCastToObjCObjectPointer(E); 4394 From = E.get(); 4395 } 4396 if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers()) 4397 CheckObjCConversion(SourceRange(), NewToType, From, CCK); 4398 From = ImpCastExprToType(From, NewToType, Kind, VK_PRValue, &BasePath, CCK) 4399 .get(); 4400 break; 4401 } 4402 4403 case ICK_Pointer_Member: { 4404 CastKind Kind; 4405 CXXCastPath BasePath; 4406 if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle)) 4407 return ExprError(); 4408 if (CheckExceptionSpecCompatibility(From, ToType)) 4409 return ExprError(); 4410 4411 // We may not have been able to figure out what this member pointer resolved 4412 // to up until this exact point. Attempt to lock-in it's inheritance model. 4413 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { 4414 (void)isCompleteType(From->getExprLoc(), From->getType()); 4415 (void)isCompleteType(From->getExprLoc(), ToType); 4416 } 4417 4418 From = 4419 ImpCastExprToType(From, ToType, Kind, VK_PRValue, &BasePath, CCK).get(); 4420 break; 4421 } 4422 4423 case ICK_Boolean_Conversion: 4424 // Perform half-to-boolean conversion via float. 4425 if (From->getType()->isHalfType()) { 4426 From = ImpCastExprToType(From, Context.FloatTy, CK_FloatingCast).get(); 4427 FromType = Context.FloatTy; 4428 } 4429 4430 From = ImpCastExprToType(From, Context.BoolTy, 4431 ScalarTypeToBooleanCastKind(FromType), VK_PRValue, 4432 /*BasePath=*/nullptr, CCK) 4433 .get(); 4434 break; 4435 4436 case ICK_Derived_To_Base: { 4437 CXXCastPath BasePath; 4438 if (CheckDerivedToBaseConversion( 4439 From->getType(), ToType.getNonReferenceType(), From->getBeginLoc(), 4440 From->getSourceRange(), &BasePath, CStyle)) 4441 return ExprError(); 4442 4443 From = ImpCastExprToType(From, ToType.getNonReferenceType(), 4444 CK_DerivedToBase, From->getValueKind(), 4445 &BasePath, CCK).get(); 4446 break; 4447 } 4448 4449 case ICK_Vector_Conversion: 4450 From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue, 4451 /*BasePath=*/nullptr, CCK) 4452 .get(); 4453 break; 4454 4455 case ICK_SVE_Vector_Conversion: 4456 From = ImpCastExprToType(From, ToType, CK_BitCast, VK_PRValue, 4457 /*BasePath=*/nullptr, CCK) 4458 .get(); 4459 break; 4460 4461 case ICK_Vector_Splat: { 4462 // Vector splat from any arithmetic type to a vector. 4463 Expr *Elem = prepareVectorSplat(ToType, From).get(); 4464 From = ImpCastExprToType(Elem, ToType, CK_VectorSplat, VK_PRValue, 4465 /*BasePath=*/nullptr, CCK) 4466 .get(); 4467 break; 4468 } 4469 4470 case ICK_Complex_Real: 4471 // Case 1. x -> _Complex y 4472 if (const ComplexType *ToComplex = ToType->getAs<ComplexType>()) { 4473 QualType ElType = ToComplex->getElementType(); 4474 bool isFloatingComplex = ElType->isRealFloatingType(); 4475 4476 // x -> y 4477 if (Context.hasSameUnqualifiedType(ElType, From->getType())) { 4478 // do nothing 4479 } else if (From->getType()->isRealFloatingType()) { 4480 From = ImpCastExprToType(From, ElType, 4481 isFloatingComplex ? CK_FloatingCast : CK_FloatingToIntegral).get(); 4482 } else { 4483 assert(From->getType()->isIntegerType())((void)0); 4484 From = ImpCastExprToType(From, ElType, 4485 isFloatingComplex ? CK_IntegralToFloating : CK_IntegralCast).get(); 4486 } 4487 // y -> _Complex y 4488 From = ImpCastExprToType(From, ToType, 4489 isFloatingComplex ? CK_FloatingRealToComplex 4490 : CK_IntegralRealToComplex).get(); 4491 4492 // Case 2. _Complex x -> y 4493 } else { 4494 auto *FromComplex = From->getType()->castAs<ComplexType>(); 4495 QualType ElType = FromComplex->getElementType(); 4496 bool isFloatingComplex = ElType->isRealFloatingType(); 4497 4498 // _Complex x -> x 4499 From = ImpCastExprToType(From, ElType, 4500 isFloatingComplex ? CK_FloatingComplexToReal 4501 : CK_IntegralComplexToReal, 4502 VK_PRValue, /*BasePath=*/nullptr, CCK) 4503 .get(); 4504 4505 // x -> y 4506 if (Context.hasSameUnqualifiedType(ElType, ToType)) { 4507 // do nothing 4508 } else if (ToType->isRealFloatingType()) { 4509 From = ImpCastExprToType(From, ToType, 4510 isFloatingComplex ? CK_FloatingCast 4511 : CK_IntegralToFloating, 4512 VK_PRValue, /*BasePath=*/nullptr, CCK) 4513 .get(); 4514 } else { 4515 assert(ToType->isIntegerType())((void)0); 4516 From = ImpCastExprToType(From, ToType, 4517 isFloatingComplex ? CK_FloatingToIntegral 4518 : CK_IntegralCast, 4519 VK_PRValue, /*BasePath=*/nullptr, CCK) 4520 .get(); 4521 } 4522 } 4523 break; 4524 4525 case ICK_Block_Pointer_Conversion: { 4526 LangAS AddrSpaceL = 4527 ToType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace(); 4528 LangAS AddrSpaceR = 4529 FromType->castAs<BlockPointerType>()->getPointeeType().getAddressSpace(); 4530 assert(Qualifiers::isAddressSpaceSupersetOf(AddrSpaceL, AddrSpaceR) &&((void)0) 4531 "Invalid cast")((void)0); 4532 CastKind Kind = 4533 AddrSpaceL != AddrSpaceR ? CK_AddressSpaceConversion : CK_BitCast; 4534 From = ImpCastExprToType(From, ToType.getUnqualifiedType(), Kind, 4535 VK_PRValue, /*BasePath=*/nullptr, CCK) 4536 .get(); 4537 break; 4538 } 4539 4540 case ICK_TransparentUnionConversion: { 4541 ExprResult FromRes = From; 4542 Sema::AssignConvertType ConvTy = 4543 CheckTransparentUnionArgumentConstraints(ToType, FromRes); 4544 if (FromRes.isInvalid()) 4545 return ExprError(); 4546 From = FromRes.get(); 4547 assert ((ConvTy == Sema::Compatible) &&((void)0) 4548 "Improper transparent union conversion")((void)0); 4549 (void)ConvTy; 4550 break; 4551 } 4552 4553 case ICK_Zero_Event_Conversion: 4554 case ICK_Zero_Queue_Conversion: 4555 From = ImpCastExprToType(From, ToType, 4556 CK_ZeroToOCLOpaqueType, 4557 From->getValueKind()).get(); 4558 break; 4559 4560 case ICK_Lvalue_To_Rvalue: 4561 case ICK_Array_To_Pointer: 4562 case ICK_Function_To_Pointer: 4563 case ICK_Function_Conversion: 4564 case ICK_Qualification: 4565 case ICK_Num_Conversion_Kinds: 4566 case ICK_C_Only_Conversion: 4567 case ICK_Incompatible_Pointer_Conversion: 4568 llvm_unreachable("Improper second standard conversion")__builtin_unreachable(); 4569 } 4570 4571 switch (SCS.Third) { 4572 case ICK_Identity: 4573 // Nothing to do. 4574 break; 4575 4576 case ICK_Function_Conversion: 4577 // If both sides are functions (or pointers/references to them), there could 4578 // be incompatible exception declarations. 4579 if (CheckExceptionSpecCompatibility(From, ToType)) 4580 return ExprError(); 4581 4582 From = ImpCastExprToType(From, ToType, CK_NoOp, VK_PRValue, 4583 /*BasePath=*/nullptr, CCK) 4584 .get(); 4585 break; 4586 4587 case ICK_Qualification: { 4588 ExprValueKind VK = From->getValueKind(); 4589 CastKind CK = CK_NoOp; 4590 4591 if (ToType->isReferenceType() && 4592 ToType->getPointeeType().getAddressSpace() != 4593 From->getType().getAddressSpace()) 4594 CK = CK_AddressSpaceConversion; 4595 4596 if (ToType->isPointerType() && 4597 ToType->getPointeeType().getAddressSpace() != 4598 From->getType()->getPointeeType().getAddressSpace()) 4599 CK = CK_AddressSpaceConversion; 4600 4601 From = ImpCastExprToType(From, ToType.getNonLValueExprType(Context), CK, VK, 4602 /*BasePath=*/nullptr, CCK) 4603 .get(); 4604 4605 if (SCS.DeprecatedStringLiteralToCharPtr && 4606 !getLangOpts().WritableStrings) { 4607 Diag(From->getBeginLoc(), 4608 getLangOpts().CPlusPlus11 4609 ? diag::ext_deprecated_string_literal_conversion 4610 : diag::warn_deprecated_string_literal_conversion) 4611 << ToType.getNonReferenceType(); 4612 } 4613 4614 break; 4615 } 4616 4617 default: 4618 llvm_unreachable("Improper third standard conversion")__builtin_unreachable(); 4619 } 4620 4621 // If this conversion sequence involved a scalar -> atomic conversion, perform 4622 // that conversion now. 4623 if (!ToAtomicType.isNull()) { 4624 assert(Context.hasSameType(((void)0) 4625 ToAtomicType->castAs<AtomicType>()->getValueType(), From->getType()))((void)0); 4626 From = ImpCastExprToType(From, ToAtomicType, CK_NonAtomicToAtomic, 4627 VK_PRValue, nullptr, CCK) 4628 .get(); 4629 } 4630 4631 // Materialize a temporary if we're implicitly converting to a reference 4632 // type. This is not required by the C++ rules but is necessary to maintain 4633 // AST invariants. 4634 if (ToType->isReferenceType() && From->isPRValue()) { 4635 ExprResult Res = TemporaryMaterializationConversion(From); 4636 if (Res.isInvalid()) 4637 return ExprError(); 4638 From = Res.get(); 4639 } 4640 4641 // If this conversion sequence succeeded and involved implicitly converting a 4642 // _Nullable type to a _Nonnull one, complain. 4643 if (!isCast(CCK)) 4644 diagnoseNullableToNonnullConversion(ToType, InitialFromType, 4645 From->getBeginLoc()); 4646 4647 return From; 4648} 4649 4650/// Check the completeness of a type in a unary type trait. 4651/// 4652/// If the particular type trait requires a complete type, tries to complete 4653/// it. If completing the type fails, a diagnostic is emitted and false 4654/// returned. If completing the type succeeds or no completion was required, 4655/// returns true. 4656static bool CheckUnaryTypeTraitTypeCompleteness(Sema &S, TypeTrait UTT, 4657 SourceLocation Loc, 4658 QualType ArgTy) { 4659 // C++0x [meta.unary.prop]p3: 4660 // For all of the class templates X declared in this Clause, instantiating 4661 // that template with a template argument that is a class template 4662 // specialization may result in the implicit instantiation of the template 4663 // argument if and only if the semantics of X require that the argument 4664 // must be a complete type. 4665 // We apply this rule to all the type trait expressions used to implement 4666 // these class templates. We also try to follow any GCC documented behavior 4667 // in these expressions to ensure portability of standard libraries. 4668 switch (UTT) { 4669 default: llvm_unreachable("not a UTT")__builtin_unreachable(); 4670 // is_complete_type somewhat obviously cannot require a complete type. 4671 case UTT_IsCompleteType: 4672 // Fall-through 4673 4674 // These traits are modeled on the type predicates in C++0x 4675 // [meta.unary.cat] and [meta.unary.comp]. They are not specified as 4676 // requiring a complete type, as whether or not they return true cannot be 4677 // impacted by the completeness of the type. 4678 case UTT_IsVoid: 4679 case UTT_IsIntegral: 4680 case UTT_IsFloatingPoint: 4681 case UTT_IsArray: 4682 case UTT_IsPointer: 4683 case UTT_IsLvalueReference: 4684 case UTT_IsRvalueReference: 4685 case UTT_IsMemberFunctionPointer: 4686 case UTT_IsMemberObjectPointer: 4687 case UTT_IsEnum: 4688 case UTT_IsUnion: 4689 case UTT_IsClass: 4690 case UTT_IsFunction: 4691 case UTT_IsReference: 4692 case UTT_IsArithmetic: 4693 case UTT_IsFundamental: 4694 case UTT_IsObject: 4695 case UTT_IsScalar: 4696 case UTT_IsCompound: 4697 case UTT_IsMemberPointer: 4698 // Fall-through 4699 4700 // These traits are modeled on type predicates in C++0x [meta.unary.prop] 4701 // which requires some of its traits to have the complete type. However, 4702 // the completeness of the type cannot impact these traits' semantics, and 4703 // so they don't require it. This matches the comments on these traits in 4704 // Table 49. 4705 case UTT_IsConst: 4706 case UTT_IsVolatile: 4707 case UTT_IsSigned: 4708 case UTT_IsUnsigned: 4709 4710 // This type trait always returns false, checking the type is moot. 4711 case UTT_IsInterfaceClass: 4712 return true; 4713 4714 // C++14 [meta.unary.prop]: 4715 // If T is a non-union class type, T shall be a complete type. 4716 case UTT_IsEmpty: 4717 case UTT_IsPolymorphic: 4718 case UTT_IsAbstract: 4719 if (const auto *RD = ArgTy->getAsCXXRecordDecl()) 4720 if (!RD->isUnion()) 4721 return !S.RequireCompleteType( 4722 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); 4723 return true; 4724 4725 // C++14 [meta.unary.prop]: 4726 // If T is a class type, T shall be a complete type. 4727 case UTT_IsFinal: 4728 case UTT_IsSealed: 4729 if (ArgTy->getAsCXXRecordDecl()) 4730 return !S.RequireCompleteType( 4731 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); 4732 return true; 4733 4734 // C++1z [meta.unary.prop]: 4735 // remove_all_extents_t<T> shall be a complete type or cv void. 4736 case UTT_IsAggregate: 4737 case UTT_IsTrivial: 4738 case UTT_IsTriviallyCopyable: 4739 case UTT_IsStandardLayout: 4740 case UTT_IsPOD: 4741 case UTT_IsLiteral: 4742 // Per the GCC type traits documentation, T shall be a complete type, cv void, 4743 // or an array of unknown bound. But GCC actually imposes the same constraints 4744 // as above. 4745 case UTT_HasNothrowAssign: 4746 case UTT_HasNothrowMoveAssign: 4747 case UTT_HasNothrowConstructor: 4748 case UTT_HasNothrowCopy: 4749 case UTT_HasTrivialAssign: 4750 case UTT_HasTrivialMoveAssign: 4751 case UTT_HasTrivialDefaultConstructor: 4752 case UTT_HasTrivialMoveConstructor: 4753 case UTT_HasTrivialCopy: 4754 case UTT_HasTrivialDestructor: 4755 case UTT_HasVirtualDestructor: 4756 ArgTy = QualType(ArgTy->getBaseElementTypeUnsafe(), 0); 4757 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 4758 4759 // C++1z [meta.unary.prop]: 4760 // T shall be a complete type, cv void, or an array of unknown bound. 4761 case UTT_IsDestructible: 4762 case UTT_IsNothrowDestructible: 4763 case UTT_IsTriviallyDestructible: 4764 case UTT_HasUniqueObjectRepresentations: 4765 if (ArgTy->isIncompleteArrayType() || ArgTy->isVoidType()) 4766 return true; 4767 4768 return !S.RequireCompleteType( 4769 Loc, ArgTy, diag::err_incomplete_type_used_in_type_trait_expr); 4770 } 4771} 4772 4773static bool HasNoThrowOperator(const RecordType *RT, OverloadedOperatorKind Op, 4774 Sema &Self, SourceLocation KeyLoc, ASTContext &C, 4775 bool (CXXRecordDecl::*HasTrivial)() const, 4776 bool (CXXRecordDecl::*HasNonTrivial)() const, 4777 bool (CXXMethodDecl::*IsDesiredOp)() const) 4778{ 4779 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 4780 if ((RD->*HasTrivial)() && !(RD->*HasNonTrivial)()) 4781 return true; 4782 4783 DeclarationName Name = C.DeclarationNames.getCXXOperatorName(Op); 4784 DeclarationNameInfo NameInfo(Name, KeyLoc); 4785 LookupResult Res(Self, NameInfo, Sema::LookupOrdinaryName); 4786 if (Self.LookupQualifiedName(Res, RD)) { 4787 bool FoundOperator = false; 4788 Res.suppressDiagnostics(); 4789 for (LookupResult::iterator Op = Res.begin(), OpEnd = Res.end(); 4790 Op != OpEnd; ++Op) { 4791 if (isa<FunctionTemplateDecl>(*Op)) 4792 continue; 4793 4794 CXXMethodDecl *Operator = cast<CXXMethodDecl>(*Op); 4795 if((Operator->*IsDesiredOp)()) { 4796 FoundOperator = true; 4797 auto *CPT = Operator->getType()->castAs<FunctionProtoType>(); 4798 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 4799 if (!CPT || !CPT->isNothrow()) 4800 return false; 4801 } 4802 } 4803 return FoundOperator; 4804 } 4805 return false; 4806} 4807 4808static bool EvaluateUnaryTypeTrait(Sema &Self, TypeTrait UTT, 4809 SourceLocation KeyLoc, QualType T) { 4810 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type")((void)0); 4811 4812 ASTContext &C = Self.Context; 4813 switch(UTT) { 4814 default: llvm_unreachable("not a UTT")__builtin_unreachable(); 4815 // Type trait expressions corresponding to the primary type category 4816 // predicates in C++0x [meta.unary.cat]. 4817 case UTT_IsVoid: 4818 return T->isVoidType(); 4819 case UTT_IsIntegral: 4820 return T->isIntegralType(C); 4821 case UTT_IsFloatingPoint: 4822 return T->isFloatingType(); 4823 case UTT_IsArray: 4824 return T->isArrayType(); 4825 case UTT_IsPointer: 4826 return T->isAnyPointerType(); 4827 case UTT_IsLvalueReference: 4828 return T->isLValueReferenceType(); 4829 case UTT_IsRvalueReference: 4830 return T->isRValueReferenceType(); 4831 case UTT_IsMemberFunctionPointer: 4832 return T->isMemberFunctionPointerType(); 4833 case UTT_IsMemberObjectPointer: 4834 return T->isMemberDataPointerType(); 4835 case UTT_IsEnum: 4836 return T->isEnumeralType(); 4837 case UTT_IsUnion: 4838 return T->isUnionType(); 4839 case UTT_IsClass: 4840 return T->isClassType() || T->isStructureType() || T->isInterfaceType(); 4841 case UTT_IsFunction: 4842 return T->isFunctionType(); 4843 4844 // Type trait expressions which correspond to the convenient composition 4845 // predicates in C++0x [meta.unary.comp]. 4846 case UTT_IsReference: 4847 return T->isReferenceType(); 4848 case UTT_IsArithmetic: 4849 return T->isArithmeticType() && !T->isEnumeralType(); 4850 case UTT_IsFundamental: 4851 return T->isFundamentalType(); 4852 case UTT_IsObject: 4853 return T->isObjectType(); 4854 case UTT_IsScalar: 4855 // Note: semantic analysis depends on Objective-C lifetime types to be 4856 // considered scalar types. However, such types do not actually behave 4857 // like scalar types at run time (since they may require retain/release 4858 // operations), so we report them as non-scalar. 4859 if (T->isObjCLifetimeType()) { 4860 switch (T.getObjCLifetime()) { 4861 case Qualifiers::OCL_None: 4862 case Qualifiers::OCL_ExplicitNone: 4863 return true; 4864 4865 case Qualifiers::OCL_Strong: 4866 case Qualifiers::OCL_Weak: 4867 case Qualifiers::OCL_Autoreleasing: 4868 return false; 4869 } 4870 } 4871 4872 return T->isScalarType(); 4873 case UTT_IsCompound: 4874 return T->isCompoundType(); 4875 case UTT_IsMemberPointer: 4876 return T->isMemberPointerType(); 4877 4878 // Type trait expressions which correspond to the type property predicates 4879 // in C++0x [meta.unary.prop]. 4880 case UTT_IsConst: 4881 return T.isConstQualified(); 4882 case UTT_IsVolatile: 4883 return T.isVolatileQualified(); 4884 case UTT_IsTrivial: 4885 return T.isTrivialType(C); 4886 case UTT_IsTriviallyCopyable: 4887 return T.isTriviallyCopyableType(C); 4888 case UTT_IsStandardLayout: 4889 return T->isStandardLayoutType(); 4890 case UTT_IsPOD: 4891 return T.isPODType(C); 4892 case UTT_IsLiteral: 4893 return T->isLiteralType(C); 4894 case UTT_IsEmpty: 4895 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 4896 return !RD->isUnion() && RD->isEmpty(); 4897 return false; 4898 case UTT_IsPolymorphic: 4899 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 4900 return !RD->isUnion() && RD->isPolymorphic(); 4901 return false; 4902 case UTT_IsAbstract: 4903 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 4904 return !RD->isUnion() && RD->isAbstract(); 4905 return false; 4906 case UTT_IsAggregate: 4907 // Report vector extensions and complex types as aggregates because they 4908 // support aggregate initialization. GCC mirrors this behavior for vectors 4909 // but not _Complex. 4910 return T->isAggregateType() || T->isVectorType() || T->isExtVectorType() || 4911 T->isAnyComplexType(); 4912 // __is_interface_class only returns true when CL is invoked in /CLR mode and 4913 // even then only when it is used with the 'interface struct ...' syntax 4914 // Clang doesn't support /CLR which makes this type trait moot. 4915 case UTT_IsInterfaceClass: 4916 return false; 4917 case UTT_IsFinal: 4918 case UTT_IsSealed: 4919 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 4920 return RD->hasAttr<FinalAttr>(); 4921 return false; 4922 case UTT_IsSigned: 4923 // Enum types should always return false. 4924 // Floating points should always return true. 4925 return T->isFloatingType() || 4926 (T->isSignedIntegerType() && !T->isEnumeralType()); 4927 case UTT_IsUnsigned: 4928 // Enum types should always return false. 4929 return T->isUnsignedIntegerType() && !T->isEnumeralType(); 4930 4931 // Type trait expressions which query classes regarding their construction, 4932 // destruction, and copying. Rather than being based directly on the 4933 // related type predicates in the standard, they are specified by both 4934 // GCC[1] and the Embarcadero C++ compiler[2], and Clang implements those 4935 // specifications. 4936 // 4937 // 1: http://gcc.gnu/.org/onlinedocs/gcc/Type-Traits.html 4938 // 2: http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 4939 // 4940 // Note that these builtins do not behave as documented in g++: if a class 4941 // has both a trivial and a non-trivial special member of a particular kind, 4942 // they return false! For now, we emulate this behavior. 4943 // FIXME: This appears to be a g++ bug: more complex cases reveal that it 4944 // does not correctly compute triviality in the presence of multiple special 4945 // members of the same kind. Revisit this once the g++ bug is fixed. 4946 case UTT_HasTrivialDefaultConstructor: 4947 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 4948 // If __is_pod (type) is true then the trait is true, else if type is 4949 // a cv class or union type (or array thereof) with a trivial default 4950 // constructor ([class.ctor]) then the trait is true, else it is false. 4951 if (T.isPODType(C)) 4952 return true; 4953 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 4954 return RD->hasTrivialDefaultConstructor() && 4955 !RD->hasNonTrivialDefaultConstructor(); 4956 return false; 4957 case UTT_HasTrivialMoveConstructor: 4958 // This trait is implemented by MSVC 2012 and needed to parse the 4959 // standard library headers. Specifically this is used as the logic 4960 // behind std::is_trivially_move_constructible (20.9.4.3). 4961 if (T.isPODType(C)) 4962 return true; 4963 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 4964 return RD->hasTrivialMoveConstructor() && !RD->hasNonTrivialMoveConstructor(); 4965 return false; 4966 case UTT_HasTrivialCopy: 4967 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 4968 // If __is_pod (type) is true or type is a reference type then 4969 // the trait is true, else if type is a cv class or union type 4970 // with a trivial copy constructor ([class.copy]) then the trait 4971 // is true, else it is false. 4972 if (T.isPODType(C) || T->isReferenceType()) 4973 return true; 4974 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 4975 return RD->hasTrivialCopyConstructor() && 4976 !RD->hasNonTrivialCopyConstructor(); 4977 return false; 4978 case UTT_HasTrivialMoveAssign: 4979 // This trait is implemented by MSVC 2012 and needed to parse the 4980 // standard library headers. Specifically it is used as the logic 4981 // behind std::is_trivially_move_assignable (20.9.4.3) 4982 if (T.isPODType(C)) 4983 return true; 4984 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 4985 return RD->hasTrivialMoveAssignment() && !RD->hasNonTrivialMoveAssignment(); 4986 return false; 4987 case UTT_HasTrivialAssign: 4988 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 4989 // If type is const qualified or is a reference type then the 4990 // trait is false. Otherwise if __is_pod (type) is true then the 4991 // trait is true, else if type is a cv class or union type with 4992 // a trivial copy assignment ([class.copy]) then the trait is 4993 // true, else it is false. 4994 // Note: the const and reference restrictions are interesting, 4995 // given that const and reference members don't prevent a class 4996 // from having a trivial copy assignment operator (but do cause 4997 // errors if the copy assignment operator is actually used, q.v. 4998 // [class.copy]p12). 4999 5000 if (T.isConstQualified()) 5001 return false; 5002 if (T.isPODType(C)) 5003 return true; 5004 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 5005 return RD->hasTrivialCopyAssignment() && 5006 !RD->hasNonTrivialCopyAssignment(); 5007 return false; 5008 case UTT_IsDestructible: 5009 case UTT_IsTriviallyDestructible: 5010 case UTT_IsNothrowDestructible: 5011 // C++14 [meta.unary.prop]: 5012 // For reference types, is_destructible<T>::value is true. 5013 if (T->isReferenceType()) 5014 return true; 5015 5016 // Objective-C++ ARC: autorelease types don't require destruction. 5017 if (T->isObjCLifetimeType() && 5018 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 5019 return true; 5020 5021 // C++14 [meta.unary.prop]: 5022 // For incomplete types and function types, is_destructible<T>::value is 5023 // false. 5024 if (T->isIncompleteType() || T->isFunctionType()) 5025 return false; 5026 5027 // A type that requires destruction (via a non-trivial destructor or ARC 5028 // lifetime semantics) is not trivially-destructible. 5029 if (UTT == UTT_IsTriviallyDestructible && T.isDestructedType()) 5030 return false; 5031 5032 // C++14 [meta.unary.prop]: 5033 // For object types and given U equal to remove_all_extents_t<T>, if the 5034 // expression std::declval<U&>().~U() is well-formed when treated as an 5035 // unevaluated operand (Clause 5), then is_destructible<T>::value is true 5036 if (auto *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { 5037 CXXDestructorDecl *Destructor = Self.LookupDestructor(RD); 5038 if (!Destructor) 5039 return false; 5040 // C++14 [dcl.fct.def.delete]p2: 5041 // A program that refers to a deleted function implicitly or 5042 // explicitly, other than to declare it, is ill-formed. 5043 if (Destructor->isDeleted()) 5044 return false; 5045 if (C.getLangOpts().AccessControl && Destructor->getAccess() != AS_public) 5046 return false; 5047 if (UTT == UTT_IsNothrowDestructible) { 5048 auto *CPT = Destructor->getType()->castAs<FunctionProtoType>(); 5049 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 5050 if (!CPT || !CPT->isNothrow()) 5051 return false; 5052 } 5053 } 5054 return true; 5055 5056 case UTT_HasTrivialDestructor: 5057 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 5058 // If __is_pod (type) is true or type is a reference type 5059 // then the trait is true, else if type is a cv class or union 5060 // type (or array thereof) with a trivial destructor 5061 // ([class.dtor]) then the trait is true, else it is 5062 // false. 5063 if (T.isPODType(C) || T->isReferenceType()) 5064 return true; 5065 5066 // Objective-C++ ARC: autorelease types don't require destruction. 5067 if (T->isObjCLifetimeType() && 5068 T.getObjCLifetime() == Qualifiers::OCL_Autoreleasing) 5069 return true; 5070 5071 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) 5072 return RD->hasTrivialDestructor(); 5073 return false; 5074 // TODO: Propagate nothrowness for implicitly declared special members. 5075 case UTT_HasNothrowAssign: 5076 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 5077 // If type is const qualified or is a reference type then the 5078 // trait is false. Otherwise if __has_trivial_assign (type) 5079 // is true then the trait is true, else if type is a cv class 5080 // or union type with copy assignment operators that are known 5081 // not to throw an exception then the trait is true, else it is 5082 // false. 5083 if (C.getBaseElementType(T).isConstQualified()) 5084 return false; 5085 if (T->isReferenceType()) 5086 return false; 5087 if (T.isPODType(C) || T->isObjCLifetimeType()) 5088 return true; 5089 5090 if (const RecordType *RT = T->getAs<RecordType>()) 5091 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 5092 &CXXRecordDecl::hasTrivialCopyAssignment, 5093 &CXXRecordDecl::hasNonTrivialCopyAssignment, 5094 &CXXMethodDecl::isCopyAssignmentOperator); 5095 return false; 5096 case UTT_HasNothrowMoveAssign: 5097 // This trait is implemented by MSVC 2012 and needed to parse the 5098 // standard library headers. Specifically this is used as the logic 5099 // behind std::is_nothrow_move_assignable (20.9.4.3). 5100 if (T.isPODType(C)) 5101 return true; 5102 5103 if (const RecordType *RT = C.getBaseElementType(T)->getAs<RecordType>()) 5104 return HasNoThrowOperator(RT, OO_Equal, Self, KeyLoc, C, 5105 &CXXRecordDecl::hasTrivialMoveAssignment, 5106 &CXXRecordDecl::hasNonTrivialMoveAssignment, 5107 &CXXMethodDecl::isMoveAssignmentOperator); 5108 return false; 5109 case UTT_HasNothrowCopy: 5110 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 5111 // If __has_trivial_copy (type) is true then the trait is true, else 5112 // if type is a cv class or union type with copy constructors that are 5113 // known not to throw an exception then the trait is true, else it is 5114 // false. 5115 if (T.isPODType(C) || T->isReferenceType() || T->isObjCLifetimeType()) 5116 return true; 5117 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) { 5118 if (RD->hasTrivialCopyConstructor() && 5119 !RD->hasNonTrivialCopyConstructor()) 5120 return true; 5121 5122 bool FoundConstructor = false; 5123 unsigned FoundTQs; 5124 for (const auto *ND : Self.LookupConstructors(RD)) { 5125 // A template constructor is never a copy constructor. 5126 // FIXME: However, it may actually be selected at the actual overload 5127 // resolution point. 5128 if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl())) 5129 continue; 5130 // UsingDecl itself is not a constructor 5131 if (isa<UsingDecl>(ND)) 5132 continue; 5133 auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl()); 5134 if (Constructor->isCopyConstructor(FoundTQs)) { 5135 FoundConstructor = true; 5136 auto *CPT = Constructor->getType()->castAs<FunctionProtoType>(); 5137 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 5138 if (!CPT) 5139 return false; 5140 // TODO: check whether evaluating default arguments can throw. 5141 // For now, we'll be conservative and assume that they can throw. 5142 if (!CPT->isNothrow() || CPT->getNumParams() > 1) 5143 return false; 5144 } 5145 } 5146 5147 return FoundConstructor; 5148 } 5149 return false; 5150 case UTT_HasNothrowConstructor: 5151 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html 5152 // If __has_trivial_constructor (type) is true then the trait is 5153 // true, else if type is a cv class or union type (or array 5154 // thereof) with a default constructor that is known not to 5155 // throw an exception then the trait is true, else it is false. 5156 if (T.isPODType(C) || T->isObjCLifetimeType()) 5157 return true; 5158 if (CXXRecordDecl *RD = C.getBaseElementType(T)->getAsCXXRecordDecl()) { 5159 if (RD->hasTrivialDefaultConstructor() && 5160 !RD->hasNonTrivialDefaultConstructor()) 5161 return true; 5162 5163 bool FoundConstructor = false; 5164 for (const auto *ND : Self.LookupConstructors(RD)) { 5165 // FIXME: In C++0x, a constructor template can be a default constructor. 5166 if (isa<FunctionTemplateDecl>(ND->getUnderlyingDecl())) 5167 continue; 5168 // UsingDecl itself is not a constructor 5169 if (isa<UsingDecl>(ND)) 5170 continue; 5171 auto *Constructor = cast<CXXConstructorDecl>(ND->getUnderlyingDecl()); 5172 if (Constructor->isDefaultConstructor()) { 5173 FoundConstructor = true; 5174 auto *CPT = Constructor->getType()->castAs<FunctionProtoType>(); 5175 CPT = Self.ResolveExceptionSpec(KeyLoc, CPT); 5176 if (!CPT) 5177 return false; 5178 // FIXME: check whether evaluating default arguments can throw. 5179 // For now, we'll be conservative and assume that they can throw. 5180 if (!CPT->isNothrow() || CPT->getNumParams() > 0) 5181 return false; 5182 } 5183 } 5184 return FoundConstructor; 5185 } 5186 return false; 5187 case UTT_HasVirtualDestructor: 5188 // http://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html: 5189 // If type is a class type with a virtual destructor ([class.dtor]) 5190 // then the trait is true, else it is false. 5191 if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) 5192 if (CXXDestructorDecl *Destructor = Self.LookupDestructor(RD)) 5193 return Destructor->isVirtual(); 5194 return false; 5195 5196 // These type trait expressions are modeled on the specifications for the 5197 // Embarcadero C++0x type trait functions: 5198 // http://docwiki.embarcadero.com/RADStudio/XE/en/Type_Trait_Functions_(C%2B%2B0x)_Index 5199 case UTT_IsCompleteType: 5200 // http://docwiki.embarcadero.com/RADStudio/XE/en/Is_complete_type_(typename_T_): 5201 // Returns True if and only if T is a complete type at the point of the 5202 // function call. 5203 return !T->isIncompleteType(); 5204 case UTT_HasUniqueObjectRepresentations: 5205 return C.hasUniqueObjectRepresentations(T); 5206 } 5207} 5208 5209static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 5210 QualType RhsT, SourceLocation KeyLoc); 5211 5212static bool evaluateTypeTrait(Sema &S, TypeTrait Kind, SourceLocation KWLoc, 5213 ArrayRef<TypeSourceInfo *> Args, 5214 SourceLocation RParenLoc) { 5215 if (Kind <= UTT_Last) 5216 return EvaluateUnaryTypeTrait(S, Kind, KWLoc, Args[0]->getType()); 5217 5218 // Evaluate BTT_ReferenceBindsToTemporary alongside the IsConstructible 5219 // traits to avoid duplication. 5220 if (Kind <= BTT_Last && Kind != BTT_ReferenceBindsToTemporary) 5221 return EvaluateBinaryTypeTrait(S, Kind, Args[0]->getType(), 5222 Args[1]->getType(), RParenLoc); 5223 5224 switch (Kind) { 5225 case clang::BTT_ReferenceBindsToTemporary: 5226 case clang::TT_IsConstructible: 5227 case clang::TT_IsNothrowConstructible: 5228 case clang::TT_IsTriviallyConstructible: { 5229 // C++11 [meta.unary.prop]: 5230 // is_trivially_constructible is defined as: 5231 // 5232 // is_constructible<T, Args...>::value is true and the variable 5233 // definition for is_constructible, as defined below, is known to call 5234 // no operation that is not trivial. 5235 // 5236 // The predicate condition for a template specialization 5237 // is_constructible<T, Args...> shall be satisfied if and only if the 5238 // following variable definition would be well-formed for some invented 5239 // variable t: 5240 // 5241 // T t(create<Args>()...); 5242 assert(!Args.empty())((void)0); 5243 5244 // Precondition: T and all types in the parameter pack Args shall be 5245 // complete types, (possibly cv-qualified) void, or arrays of 5246 // unknown bound. 5247 for (const auto *TSI : Args) { 5248 QualType ArgTy = TSI->getType(); 5249 if (ArgTy->isVoidType() || ArgTy->isIncompleteArrayType()) 5250 continue; 5251 5252 if (S.RequireCompleteType(KWLoc, ArgTy, 5253 diag::err_incomplete_type_used_in_type_trait_expr)) 5254 return false; 5255 } 5256 5257 // Make sure the first argument is not incomplete nor a function type. 5258 QualType T = Args[0]->getType(); 5259 if (T->isIncompleteType() || T->isFunctionType()) 5260 return false; 5261 5262 // Make sure the first argument is not an abstract type. 5263 CXXRecordDecl *RD = T->getAsCXXRecordDecl(); 5264 if (RD && RD->isAbstract()) 5265 return false; 5266 5267 llvm::BumpPtrAllocator OpaqueExprAllocator; 5268 SmallVector<Expr *, 2> ArgExprs; 5269 ArgExprs.reserve(Args.size() - 1); 5270 for (unsigned I = 1, N = Args.size(); I != N; ++I) { 5271 QualType ArgTy = Args[I]->getType(); 5272 if (ArgTy->isObjectType() || ArgTy->isFunctionType()) 5273 ArgTy = S.Context.getRValueReferenceType(ArgTy); 5274 ArgExprs.push_back( 5275 new (OpaqueExprAllocator.Allocate<OpaqueValueExpr>()) 5276 OpaqueValueExpr(Args[I]->getTypeLoc().getBeginLoc(), 5277 ArgTy.getNonLValueExprType(S.Context), 5278 Expr::getValueKindForType(ArgTy))); 5279 } 5280 5281 // Perform the initialization in an unevaluated context within a SFINAE 5282 // trap at translation unit scope. 5283 EnterExpressionEvaluationContext Unevaluated( 5284 S, Sema::ExpressionEvaluationContext::Unevaluated); 5285 Sema::SFINAETrap SFINAE(S, /*AccessCheckingSFINAE=*/true); 5286 Sema::ContextRAII TUContext(S, S.Context.getTranslationUnitDecl()); 5287 InitializedEntity To(InitializedEntity::InitializeTemporary(Args[0])); 5288 InitializationKind InitKind(InitializationKind::CreateDirect(KWLoc, KWLoc, 5289 RParenLoc)); 5290 InitializationSequence Init(S, To, InitKind, ArgExprs); 5291 if (Init.Failed()) 5292 return false; 5293 5294 ExprResult Result = Init.Perform(S, To, InitKind, ArgExprs); 5295 if (Result.isInvalid() || SFINAE.hasErrorOccurred()) 5296 return false; 5297 5298 if (Kind == clang::TT_IsConstructible) 5299 return true; 5300 5301 if (Kind == clang::BTT_ReferenceBindsToTemporary) { 5302 if (!T->isReferenceType()) 5303 return false; 5304 5305 return !Init.isDirectReferenceBinding(); 5306 } 5307 5308 if (Kind == clang::TT_IsNothrowConstructible) 5309 return S.canThrow(Result.get()) == CT_Cannot; 5310 5311 if (Kind == clang::TT_IsTriviallyConstructible) { 5312 // Under Objective-C ARC and Weak, if the destination has non-trivial 5313 // Objective-C lifetime, this is a non-trivial construction. 5314 if (T.getNonReferenceType().hasNonTrivialObjCLifetime()) 5315 return false; 5316 5317 // The initialization succeeded; now make sure there are no non-trivial 5318 // calls. 5319 return !Result.get()->hasNonTrivialCall(S.Context); 5320 } 5321 5322 llvm_unreachable("unhandled type trait")__builtin_unreachable(); 5323 return false; 5324 } 5325 default: llvm_unreachable("not a TT")__builtin_unreachable(); 5326 } 5327 5328 return false; 5329} 5330 5331ExprResult Sema::BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 5332 ArrayRef<TypeSourceInfo *> Args, 5333 SourceLocation RParenLoc) { 5334 QualType ResultType = Context.getLogicalOperationType(); 5335 5336 if (Kind <= UTT_Last && !CheckUnaryTypeTraitTypeCompleteness( 5337 *this, Kind, KWLoc, Args[0]->getType())) 5338 return ExprError(); 5339 5340 bool Dependent = false; 5341 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 5342 if (Args[I]->getType()->isDependentType()) { 5343 Dependent = true; 5344 break; 5345 } 5346 } 5347 5348 bool Result = false; 5349 if (!Dependent) 5350 Result = evaluateTypeTrait(*this, Kind, KWLoc, Args, RParenLoc); 5351 5352 return TypeTraitExpr::Create(Context, ResultType, KWLoc, Kind, Args, 5353 RParenLoc, Result); 5354} 5355 5356ExprResult Sema::ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc, 5357 ArrayRef<ParsedType> Args, 5358 SourceLocation RParenLoc) { 5359 SmallVector<TypeSourceInfo *, 4> ConvertedArgs; 5360 ConvertedArgs.reserve(Args.size()); 5361 5362 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 5363 TypeSourceInfo *TInfo; 5364 QualType T = GetTypeFromParser(Args[I], &TInfo); 5365 if (!TInfo) 5366 TInfo = Context.getTrivialTypeSourceInfo(T, KWLoc); 5367 5368 ConvertedArgs.push_back(TInfo); 5369 } 5370 5371 return BuildTypeTrait(Kind, KWLoc, ConvertedArgs, RParenLoc); 5372} 5373 5374static bool EvaluateBinaryTypeTrait(Sema &Self, TypeTrait BTT, QualType LhsT, 5375 QualType RhsT, SourceLocation KeyLoc) { 5376 assert(!LhsT->isDependentType() && !RhsT->isDependentType() &&((void)0) 5377 "Cannot evaluate traits of dependent types")((void)0); 5378 5379 switch(BTT) { 5380 case BTT_IsBaseOf: { 5381 // C++0x [meta.rel]p2 5382 // Base is a base class of Derived without regard to cv-qualifiers or 5383 // Base and Derived are not unions and name the same class type without 5384 // regard to cv-qualifiers. 5385 5386 const RecordType *lhsRecord = LhsT->getAs<RecordType>(); 5387 const RecordType *rhsRecord = RhsT->getAs<RecordType>(); 5388 if (!rhsRecord || !lhsRecord) { 5389 const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>(); 5390 const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>(); 5391 if (!LHSObjTy || !RHSObjTy) 5392 return false; 5393 5394 ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface(); 5395 ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface(); 5396 if (!BaseInterface || !DerivedInterface) 5397 return false; 5398 5399 if (Self.RequireCompleteType( 5400 KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr)) 5401 return false; 5402 5403 return BaseInterface->isSuperClassOf(DerivedInterface); 5404 } 5405 5406 assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)((void)0) 5407 == (lhsRecord == rhsRecord))((void)0); 5408 5409 // Unions are never base classes, and never have base classes. 5410 // It doesn't matter if they are complete or not. See PR#41843 5411 if (lhsRecord && lhsRecord->getDecl()->isUnion()) 5412 return false; 5413 if (rhsRecord && rhsRecord->getDecl()->isUnion()) 5414 return false; 5415 5416 if (lhsRecord == rhsRecord) 5417 return true; 5418 5419 // C++0x [meta.rel]p2: 5420 // If Base and Derived are class types and are different types 5421 // (ignoring possible cv-qualifiers) then Derived shall be a 5422 // complete type. 5423 if (Self.RequireCompleteType(KeyLoc, RhsT, 5424 diag::err_incomplete_type_used_in_type_trait_expr)) 5425 return false; 5426 5427 return cast<CXXRecordDecl>(rhsRecord->getDecl()) 5428 ->isDerivedFrom(cast<CXXRecordDecl>(lhsRecord->getDecl())); 5429 } 5430 case BTT_IsSame: 5431 return Self.Context.hasSameType(LhsT, RhsT); 5432 case BTT_TypeCompatible: { 5433 // GCC ignores cv-qualifiers on arrays for this builtin. 5434 Qualifiers LhsQuals, RhsQuals; 5435 QualType Lhs = Self.getASTContext().getUnqualifiedArrayType(LhsT, LhsQuals); 5436 QualType Rhs = Self.getASTContext().getUnqualifiedArrayType(RhsT, RhsQuals); 5437 return Self.Context.typesAreCompatible(Lhs, Rhs); 5438 } 5439 case BTT_IsConvertible: 5440 case BTT_IsConvertibleTo: { 5441 // C++0x [meta.rel]p4: 5442 // Given the following function prototype: 5443 // 5444 // template <class T> 5445 // typename add_rvalue_reference<T>::type create(); 5446 // 5447 // the predicate condition for a template specialization 5448 // is_convertible<From, To> shall be satisfied if and only if 5449 // the return expression in the following code would be 5450 // well-formed, including any implicit conversions to the return 5451 // type of the function: 5452 // 5453 // To test() { 5454 // return create<From>(); 5455 // } 5456 // 5457 // Access checking is performed as if in a context unrelated to To and 5458 // From. Only the validity of the immediate context of the expression 5459 // of the return-statement (including conversions to the return type) 5460 // is considered. 5461 // 5462 // We model the initialization as a copy-initialization of a temporary 5463 // of the appropriate type, which for this expression is identical to the 5464 // return statement (since NRVO doesn't apply). 5465 5466 // Functions aren't allowed to return function or array types. 5467 if (RhsT->isFunctionType() || RhsT->isArrayType()) 5468 return false; 5469 5470 // A return statement in a void function must have void type. 5471 if (RhsT->isVoidType()) 5472 return LhsT->isVoidType(); 5473 5474 // A function definition requires a complete, non-abstract return type. 5475 if (!Self.isCompleteType(KeyLoc, RhsT) || Self.isAbstractType(KeyLoc, RhsT)) 5476 return false; 5477 5478 // Compute the result of add_rvalue_reference. 5479 if (LhsT->isObjectType() || LhsT->isFunctionType()) 5480 LhsT = Self.Context.getRValueReferenceType(LhsT); 5481 5482 // Build a fake source and destination for initialization. 5483 InitializedEntity To(InitializedEntity::InitializeTemporary(RhsT)); 5484 OpaqueValueExpr From(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 5485 Expr::getValueKindForType(LhsT)); 5486 Expr *FromPtr = &From; 5487 InitializationKind Kind(InitializationKind::CreateCopy(KeyLoc, 5488 SourceLocation())); 5489 5490 // Perform the initialization in an unevaluated context within a SFINAE 5491 // trap at translation unit scope. 5492 EnterExpressionEvaluationContext Unevaluated( 5493 Self, Sema::ExpressionEvaluationContext::Unevaluated); 5494 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 5495 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 5496 InitializationSequence Init(Self, To, Kind, FromPtr); 5497 if (Init.Failed()) 5498 return false; 5499 5500 ExprResult Result = Init.Perform(Self, To, Kind, FromPtr); 5501 return !Result.isInvalid() && !SFINAE.hasErrorOccurred(); 5502 } 5503 5504 case BTT_IsAssignable: 5505 case BTT_IsNothrowAssignable: 5506 case BTT_IsTriviallyAssignable: { 5507 // C++11 [meta.unary.prop]p3: 5508 // is_trivially_assignable is defined as: 5509 // is_assignable<T, U>::value is true and the assignment, as defined by 5510 // is_assignable, is known to call no operation that is not trivial 5511 // 5512 // is_assignable is defined as: 5513 // The expression declval<T>() = declval<U>() is well-formed when 5514 // treated as an unevaluated operand (Clause 5). 5515 // 5516 // For both, T and U shall be complete types, (possibly cv-qualified) 5517 // void, or arrays of unknown bound. 5518 if (!LhsT->isVoidType() && !LhsT->isIncompleteArrayType() && 5519 Self.RequireCompleteType(KeyLoc, LhsT, 5520 diag::err_incomplete_type_used_in_type_trait_expr)) 5521 return false; 5522 if (!RhsT->isVoidType() && !RhsT->isIncompleteArrayType() && 5523 Self.RequireCompleteType(KeyLoc, RhsT, 5524 diag::err_incomplete_type_used_in_type_trait_expr)) 5525 return false; 5526 5527 // cv void is never assignable. 5528 if (LhsT->isVoidType() || RhsT->isVoidType()) 5529 return false; 5530 5531 // Build expressions that emulate the effect of declval<T>() and 5532 // declval<U>(). 5533 if (LhsT->isObjectType() || LhsT->isFunctionType()) 5534 LhsT = Self.Context.getRValueReferenceType(LhsT); 5535 if (RhsT->isObjectType() || RhsT->isFunctionType()) 5536 RhsT = Self.Context.getRValueReferenceType(RhsT); 5537 OpaqueValueExpr Lhs(KeyLoc, LhsT.getNonLValueExprType(Self.Context), 5538 Expr::getValueKindForType(LhsT)); 5539 OpaqueValueExpr Rhs(KeyLoc, RhsT.getNonLValueExprType(Self.Context), 5540 Expr::getValueKindForType(RhsT)); 5541 5542 // Attempt the assignment in an unevaluated context within a SFINAE 5543 // trap at translation unit scope. 5544 EnterExpressionEvaluationContext Unevaluated( 5545 Self, Sema::ExpressionEvaluationContext::Unevaluated); 5546 Sema::SFINAETrap SFINAE(Self, /*AccessCheckingSFINAE=*/true); 5547 Sema::ContextRAII TUContext(Self, Self.Context.getTranslationUnitDecl()); 5548 ExprResult Result = Self.BuildBinOp(/*S=*/nullptr, KeyLoc, BO_Assign, &Lhs, 5549 &Rhs); 5550 if (Result.isInvalid()) 5551 return false; 5552 5553 // Treat the assignment as unused for the purpose of -Wdeprecated-volatile. 5554 Self.CheckUnusedVolatileAssignment(Result.get()); 5555 5556 if (SFINAE.hasErrorOccurred()) 5557 return false; 5558 5559 if (BTT == BTT_IsAssignable) 5560 return true; 5561 5562 if (BTT == BTT_IsNothrowAssignable) 5563 return Self.canThrow(Result.get()) == CT_Cannot; 5564 5565 if (BTT == BTT_IsTriviallyAssignable) { 5566 // Under Objective-C ARC and Weak, if the destination has non-trivial 5567 // Objective-C lifetime, this is a non-trivial assignment. 5568 if (LhsT.getNonReferenceType().hasNonTrivialObjCLifetime()) 5569 return false; 5570 5571 return !Result.get()->hasNonTrivialCall(Self.Context); 5572 } 5573 5574 llvm_unreachable("unhandled type trait")__builtin_unreachable(); 5575 return false; 5576 } 5577 default: llvm_unreachable("not a BTT")__builtin_unreachable(); 5578 } 5579 llvm_unreachable("Unknown type trait or not implemented")__builtin_unreachable(); 5580} 5581 5582ExprResult Sema::ActOnArrayTypeTrait(ArrayTypeTrait ATT, 5583 SourceLocation KWLoc, 5584 ParsedType Ty, 5585 Expr* DimExpr, 5586 SourceLocation RParen) { 5587 TypeSourceInfo *TSInfo; 5588 QualType T = GetTypeFromParser(Ty, &TSInfo); 5589 if (!TSInfo) 5590 TSInfo = Context.getTrivialTypeSourceInfo(T); 5591 5592 return BuildArrayTypeTrait(ATT, KWLoc, TSInfo, DimExpr, RParen); 5593} 5594 5595static uint64_t EvaluateArrayTypeTrait(Sema &Self, ArrayTypeTrait ATT, 5596 QualType T, Expr *DimExpr, 5597 SourceLocation KeyLoc) { 5598 assert(!T->isDependentType() && "Cannot evaluate traits of dependent type")((void)0); 5599 5600 switch(ATT) { 5601 case ATT_ArrayRank: 5602 if (T->isArrayType()) { 5603 unsigned Dim = 0; 5604 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 5605 ++Dim; 5606 T = AT->getElementType(); 5607 } 5608 return Dim; 5609 } 5610 return 0; 5611 5612 case ATT_ArrayExtent: { 5613 llvm::APSInt Value; 5614 uint64_t Dim; 5615 if (Self.VerifyIntegerConstantExpression( 5616 DimExpr, &Value, diag::err_dimension_expr_not_constant_integer) 5617 .isInvalid()) 5618 return 0; 5619 if (Value.isSigned() && Value.isNegative()) { 5620 Self.Diag(KeyLoc, diag::err_dimension_expr_not_constant_integer) 5621 << DimExpr->getSourceRange(); 5622 return 0; 5623 } 5624 Dim = Value.getLimitedValue(); 5625 5626 if (T->isArrayType()) { 5627 unsigned D = 0; 5628 bool Matched = false; 5629 while (const ArrayType *AT = Self.Context.getAsArrayType(T)) { 5630 if (Dim == D) { 5631 Matched = true; 5632 break; 5633 } 5634 ++D; 5635 T = AT->getElementType(); 5636 } 5637 5638 if (Matched && T->isArrayType()) { 5639 if (const ConstantArrayType *CAT = Self.Context.getAsConstantArrayType(T)) 5640 return CAT->getSize().getLimitedValue(); 5641 } 5642 } 5643 return 0; 5644 } 5645 } 5646 llvm_unreachable("Unknown type trait or not implemented")__builtin_unreachable(); 5647} 5648 5649ExprResult Sema::BuildArrayTypeTrait(ArrayTypeTrait ATT, 5650 SourceLocation KWLoc, 5651 TypeSourceInfo *TSInfo, 5652 Expr* DimExpr, 5653 SourceLocation RParen) { 5654 QualType T = TSInfo->getType(); 5655 5656 // FIXME: This should likely be tracked as an APInt to remove any host 5657 // assumptions about the width of size_t on the target. 5658 uint64_t Value = 0; 5659 if (!T->isDependentType()) 5660 Value = EvaluateArrayTypeTrait(*this, ATT, T, DimExpr, KWLoc); 5661 5662 // While the specification for these traits from the Embarcadero C++ 5663 // compiler's documentation says the return type is 'unsigned int', Clang 5664 // returns 'size_t'. On Windows, the primary platform for the Embarcadero 5665 // compiler, there is no difference. On several other platforms this is an 5666 // important distinction. 5667 return new (Context) ArrayTypeTraitExpr(KWLoc, ATT, TSInfo, Value, DimExpr, 5668 RParen, Context.getSizeType()); 5669} 5670 5671ExprResult Sema::ActOnExpressionTrait(ExpressionTrait ET, 5672 SourceLocation KWLoc, 5673 Expr *Queried, 5674 SourceLocation RParen) { 5675 // If error parsing the expression, ignore. 5676 if (!Queried) 5677 return ExprError(); 5678 5679 ExprResult Result = BuildExpressionTrait(ET, KWLoc, Queried, RParen); 5680 5681 return Result; 5682} 5683 5684static bool EvaluateExpressionTrait(ExpressionTrait ET, Expr *E) { 5685 switch (ET) { 5686 case ET_IsLValueExpr: return E->isLValue(); 5687 case ET_IsRValueExpr: 5688 return E->isPRValue(); 5689 } 5690 llvm_unreachable("Expression trait not covered by switch")__builtin_unreachable(); 5691} 5692 5693ExprResult Sema::BuildExpressionTrait(ExpressionTrait ET, 5694 SourceLocation KWLoc, 5695 Expr *Queried, 5696 SourceLocation RParen) { 5697 if (Queried->isTypeDependent()) { 5698 // Delay type-checking for type-dependent expressions. 5699 } else if (Queried->getType()->isPlaceholderType()) { 5700 ExprResult PE = CheckPlaceholderExpr(Queried); 5701 if (PE.isInvalid()) return ExprError(); 5702 return BuildExpressionTrait(ET, KWLoc, PE.get(), RParen); 5703 } 5704 5705 bool Value = EvaluateExpressionTrait(ET, Queried); 5706 5707 return new (Context) 5708 ExpressionTraitExpr(KWLoc, ET, Queried, Value, RParen, Context.BoolTy); 5709} 5710 5711QualType Sema::CheckPointerToMemberOperands(ExprResult &LHS, ExprResult &RHS, 5712 ExprValueKind &VK, 5713 SourceLocation Loc, 5714 bool isIndirect) { 5715 assert(!LHS.get()->getType()->isPlaceholderType() &&((void)0) 5716 !RHS.get()->getType()->isPlaceholderType() &&((void)0) 5717 "placeholders should have been weeded out by now")((void)0); 5718 5719 // The LHS undergoes lvalue conversions if this is ->*, and undergoes the 5720 // temporary materialization conversion otherwise. 5721 if (isIndirect) 5722 LHS = DefaultLvalueConversion(LHS.get()); 5723 else if (LHS.get()->isPRValue()) 5724 LHS = TemporaryMaterializationConversion(LHS.get()); 5725 if (LHS.isInvalid()) 5726 return QualType(); 5727 5728 // The RHS always undergoes lvalue conversions. 5729 RHS = DefaultLvalueConversion(RHS.get()); 5730 if (RHS.isInvalid()) return QualType(); 5731 5732 const char *OpSpelling = isIndirect ? "->*" : ".*"; 5733 // C++ 5.5p2 5734 // The binary operator .* [p3: ->*] binds its second operand, which shall 5735 // be of type "pointer to member of T" (where T is a completely-defined 5736 // class type) [...] 5737 QualType RHSType = RHS.get()->getType(); 5738 const MemberPointerType *MemPtr = RHSType->getAs<MemberPointerType>(); 5739 if (!MemPtr) { 5740 Diag(Loc, diag::err_bad_memptr_rhs) 5741 << OpSpelling << RHSType << RHS.get()->getSourceRange(); 5742 return QualType(); 5743 } 5744 5745 QualType Class(MemPtr->getClass(), 0); 5746 5747 // Note: C++ [expr.mptr.oper]p2-3 says that the class type into which the 5748 // member pointer points must be completely-defined. However, there is no 5749 // reason for this semantic distinction, and the rule is not enforced by 5750 // other compilers. Therefore, we do not check this property, as it is 5751 // likely to be considered a defect. 5752 5753 // C++ 5.5p2 5754 // [...] to its first operand, which shall be of class T or of a class of 5755 // which T is an unambiguous and accessible base class. [p3: a pointer to 5756 // such a class] 5757 QualType LHSType = LHS.get()->getType(); 5758 if (isIndirect) { 5759 if (const PointerType *Ptr = LHSType->getAs<PointerType>()) 5760 LHSType = Ptr->getPointeeType(); 5761 else { 5762 Diag(Loc, diag::err_bad_memptr_lhs) 5763 << OpSpelling << 1 << LHSType 5764 << FixItHint::CreateReplacement(SourceRange(Loc), ".*"); 5765 return QualType(); 5766 } 5767 } 5768 5769 if (!Context.hasSameUnqualifiedType(Class, LHSType)) { 5770 // If we want to check the hierarchy, we need a complete type. 5771 if (RequireCompleteType(Loc, LHSType, diag::err_bad_memptr_lhs, 5772 OpSpelling, (int)isIndirect)) { 5773 return QualType(); 5774 } 5775 5776 if (!IsDerivedFrom(Loc, LHSType, Class)) { 5777 Diag(Loc, diag::err_bad_memptr_lhs) << OpSpelling 5778 << (int)isIndirect << LHS.get()->getType(); 5779 return QualType(); 5780 } 5781 5782 CXXCastPath BasePath; 5783 if (CheckDerivedToBaseConversion( 5784 LHSType, Class, Loc, 5785 SourceRange(LHS.get()->getBeginLoc(), RHS.get()->getEndLoc()), 5786 &BasePath)) 5787 return QualType(); 5788 5789 // Cast LHS to type of use. 5790 QualType UseType = Context.getQualifiedType(Class, LHSType.getQualifiers()); 5791 if (isIndirect) 5792 UseType = Context.getPointerType(UseType); 5793 ExprValueKind VK = isIndirect ? VK_PRValue : LHS.get()->getValueKind(); 5794 LHS = ImpCastExprToType(LHS.get(), UseType, CK_DerivedToBase, VK, 5795 &BasePath); 5796 } 5797 5798 if (isa<CXXScalarValueInitExpr>(RHS.get()->IgnoreParens())) { 5799 // Diagnose use of pointer-to-member type which when used as 5800 // the functional cast in a pointer-to-member expression. 5801 Diag(Loc, diag::err_pointer_to_member_type) << isIndirect; 5802 return QualType(); 5803 } 5804 5805 // C++ 5.5p2 5806 // The result is an object or a function of the type specified by the 5807 // second operand. 5808 // The cv qualifiers are the union of those in the pointer and the left side, 5809 // in accordance with 5.5p5 and 5.2.5. 5810 QualType Result = MemPtr->getPointeeType(); 5811 Result = Context.getCVRQualifiedType(Result, LHSType.getCVRQualifiers()); 5812 5813 // C++0x [expr.mptr.oper]p6: 5814 // In a .* expression whose object expression is an rvalue, the program is 5815 // ill-formed if the second operand is a pointer to member function with 5816 // ref-qualifier &. In a ->* expression or in a .* expression whose object 5817 // expression is an lvalue, the program is ill-formed if the second operand 5818 // is a pointer to member function with ref-qualifier &&. 5819 if (const FunctionProtoType *Proto = Result->getAs<FunctionProtoType>()) { 5820 switch (Proto->getRefQualifier()) { 5821 case RQ_None: 5822 // Do nothing 5823 break; 5824 5825 case RQ_LValue: 5826 if (!isIndirect && !LHS.get()->Classify(Context).isLValue()) { 5827 // C++2a allows functions with ref-qualifier & if their cv-qualifier-seq 5828 // is (exactly) 'const'. 5829 if (Proto->isConst() && !Proto->isVolatile()) 5830 Diag(Loc, getLangOpts().CPlusPlus20 5831 ? diag::warn_cxx17_compat_pointer_to_const_ref_member_on_rvalue 5832 : diag::ext_pointer_to_const_ref_member_on_rvalue); 5833 else 5834 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 5835 << RHSType << 1 << LHS.get()->getSourceRange(); 5836 } 5837 break; 5838 5839 case RQ_RValue: 5840 if (isIndirect || !LHS.get()->Classify(Context).isRValue()) 5841 Diag(Loc, diag::err_pointer_to_member_oper_value_classify) 5842 << RHSType << 0 << LHS.get()->getSourceRange(); 5843 break; 5844 } 5845 } 5846 5847 // C++ [expr.mptr.oper]p6: 5848 // The result of a .* expression whose second operand is a pointer 5849 // to a data member is of the same value category as its 5850 // first operand. The result of a .* expression whose second 5851 // operand is a pointer to a member function is a prvalue. The 5852 // result of an ->* expression is an lvalue if its second operand 5853 // is a pointer to data member and a prvalue otherwise. 5854 if (Result->isFunctionType()) { 5855 VK = VK_PRValue; 5856 return Context.BoundMemberTy; 5857 } else if (isIndirect) { 5858 VK = VK_LValue; 5859 } else { 5860 VK = LHS.get()->getValueKind(); 5861 } 5862 5863 return Result; 5864} 5865 5866/// Try to convert a type to another according to C++11 5.16p3. 5867/// 5868/// This is part of the parameter validation for the ? operator. If either 5869/// value operand is a class type, the two operands are attempted to be 5870/// converted to each other. This function does the conversion in one direction. 5871/// It returns true if the program is ill-formed and has already been diagnosed 5872/// as such. 5873static bool TryClassUnification(Sema &Self, Expr *From, Expr *To, 5874 SourceLocation QuestionLoc, 5875 bool &HaveConversion, 5876 QualType &ToType) { 5877 HaveConversion = false; 5878 ToType = To->getType(); 5879 5880 InitializationKind Kind = 5881 InitializationKind::CreateCopy(To->getBeginLoc(), SourceLocation()); 5882 // C++11 5.16p3 5883 // The process for determining whether an operand expression E1 of type T1 5884 // can be converted to match an operand expression E2 of type T2 is defined 5885 // as follows: 5886 // -- If E2 is an lvalue: E1 can be converted to match E2 if E1 can be 5887 // implicitly converted to type "lvalue reference to T2", subject to the 5888 // constraint that in the conversion the reference must bind directly to 5889 // an lvalue. 5890 // -- If E2 is an xvalue: E1 can be converted to match E2 if E1 can be 5891 // implicitly converted to the type "rvalue reference to R2", subject to 5892 // the constraint that the reference must bind directly. 5893 if (To->isLValue() || To->isXValue()) { 5894 QualType T = To->isLValue() ? Self.Context.getLValueReferenceType(ToType) 5895 : Self.Context.getRValueReferenceType(ToType); 5896 5897 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 5898 5899 InitializationSequence InitSeq(Self, Entity, Kind, From); 5900 if (InitSeq.isDirectReferenceBinding()) { 5901 ToType = T; 5902 HaveConversion = true; 5903 return false; 5904 } 5905 5906 if (InitSeq.isAmbiguous()) 5907 return InitSeq.Diagnose(Self, Entity, Kind, From); 5908 } 5909 5910 // -- If E2 is an rvalue, or if the conversion above cannot be done: 5911 // -- if E1 and E2 have class type, and the underlying class types are 5912 // the same or one is a base class of the other: 5913 QualType FTy = From->getType(); 5914 QualType TTy = To->getType(); 5915 const RecordType *FRec = FTy->getAs<RecordType>(); 5916 const RecordType *TRec = TTy->getAs<RecordType>(); 5917 bool FDerivedFromT = FRec && TRec && FRec != TRec && 5918 Self.IsDerivedFrom(QuestionLoc, FTy, TTy); 5919 if (FRec && TRec && (FRec == TRec || FDerivedFromT || 5920 Self.IsDerivedFrom(QuestionLoc, TTy, FTy))) { 5921 // E1 can be converted to match E2 if the class of T2 is the 5922 // same type as, or a base class of, the class of T1, and 5923 // [cv2 > cv1]. 5924 if (FRec == TRec || FDerivedFromT) { 5925 if (TTy.isAtLeastAsQualifiedAs(FTy)) { 5926 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 5927 InitializationSequence InitSeq(Self, Entity, Kind, From); 5928 if (InitSeq) { 5929 HaveConversion = true; 5930 return false; 5931 } 5932 5933 if (InitSeq.isAmbiguous()) 5934 return InitSeq.Diagnose(Self, Entity, Kind, From); 5935 } 5936 } 5937 5938 return false; 5939 } 5940 5941 // -- Otherwise: E1 can be converted to match E2 if E1 can be 5942 // implicitly converted to the type that expression E2 would have 5943 // if E2 were converted to an rvalue (or the type it has, if E2 is 5944 // an rvalue). 5945 // 5946 // This actually refers very narrowly to the lvalue-to-rvalue conversion, not 5947 // to the array-to-pointer or function-to-pointer conversions. 5948 TTy = TTy.getNonLValueExprType(Self.Context); 5949 5950 InitializedEntity Entity = InitializedEntity::InitializeTemporary(TTy); 5951 InitializationSequence InitSeq(Self, Entity, Kind, From); 5952 HaveConversion = !InitSeq.Failed(); 5953 ToType = TTy; 5954 if (InitSeq.isAmbiguous()) 5955 return InitSeq.Diagnose(Self, Entity, Kind, From); 5956 5957 return false; 5958} 5959 5960/// Try to find a common type for two according to C++0x 5.16p5. 5961/// 5962/// This is part of the parameter validation for the ? operator. If either 5963/// value operand is a class type, overload resolution is used to find a 5964/// conversion to a common type. 5965static bool FindConditionalOverload(Sema &Self, ExprResult &LHS, ExprResult &RHS, 5966 SourceLocation QuestionLoc) { 5967 Expr *Args[2] = { LHS.get(), RHS.get() }; 5968 OverloadCandidateSet CandidateSet(QuestionLoc, 5969 OverloadCandidateSet::CSK_Operator); 5970 Self.AddBuiltinOperatorCandidates(OO_Conditional, QuestionLoc, Args, 5971 CandidateSet); 5972 5973 OverloadCandidateSet::iterator Best; 5974 switch (CandidateSet.BestViableFunction(Self, QuestionLoc, Best)) { 5975 case OR_Success: { 5976 // We found a match. Perform the conversions on the arguments and move on. 5977 ExprResult LHSRes = Self.PerformImplicitConversion( 5978 LHS.get(), Best->BuiltinParamTypes[0], Best->Conversions[0], 5979 Sema::AA_Converting); 5980 if (LHSRes.isInvalid()) 5981 break; 5982 LHS = LHSRes; 5983 5984 ExprResult RHSRes = Self.PerformImplicitConversion( 5985 RHS.get(), Best->BuiltinParamTypes[1], Best->Conversions[1], 5986 Sema::AA_Converting); 5987 if (RHSRes.isInvalid()) 5988 break; 5989 RHS = RHSRes; 5990 if (Best->Function) 5991 Self.MarkFunctionReferenced(QuestionLoc, Best->Function); 5992 return false; 5993 } 5994 5995 case OR_No_Viable_Function: 5996 5997 // Emit a better diagnostic if one of the expressions is a null pointer 5998 // constant and the other is a pointer type. In this case, the user most 5999 // likely forgot to take the address of the other expression. 6000 if (Self.DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 6001 return true; 6002 6003 Self.Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 6004 << LHS.get()->getType() << RHS.get()->getType() 6005 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6006 return true; 6007 6008 case OR_Ambiguous: 6009 Self.Diag(QuestionLoc, diag::err_conditional_ambiguous_ovl) 6010 << LHS.get()->getType() << RHS.get()->getType() 6011 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6012 // FIXME: Print the possible common types by printing the return types of 6013 // the viable candidates. 6014 break; 6015 6016 case OR_Deleted: 6017 llvm_unreachable("Conditional operator has only built-in overloads")__builtin_unreachable(); 6018 } 6019 return true; 6020} 6021 6022/// Perform an "extended" implicit conversion as returned by 6023/// TryClassUnification. 6024static bool ConvertForConditional(Sema &Self, ExprResult &E, QualType T) { 6025 InitializedEntity Entity = InitializedEntity::InitializeTemporary(T); 6026 InitializationKind Kind = 6027 InitializationKind::CreateCopy(E.get()->getBeginLoc(), SourceLocation()); 6028 Expr *Arg = E.get(); 6029 InitializationSequence InitSeq(Self, Entity, Kind, Arg); 6030 ExprResult Result = InitSeq.Perform(Self, Entity, Kind, Arg); 6031 if (Result.isInvalid()) 6032 return true; 6033 6034 E = Result; 6035 return false; 6036} 6037 6038// Check the condition operand of ?: to see if it is valid for the GCC 6039// extension. 6040static bool isValidVectorForConditionalCondition(ASTContext &Ctx, 6041 QualType CondTy) { 6042 if (!CondTy->isVectorType() && !CondTy->isExtVectorType()) 6043 return false; 6044 const QualType EltTy = 6045 cast<VectorType>(CondTy.getCanonicalType())->getElementType(); 6046 assert(!EltTy->isBooleanType() && !EltTy->isEnumeralType() &&((void)0) 6047 "Vectors cant be boolean or enum types")((void)0); 6048 return EltTy->isIntegralType(Ctx); 6049} 6050 6051QualType Sema::CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS, 6052 ExprResult &RHS, 6053 SourceLocation QuestionLoc) { 6054 LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); 6055 RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); 6056 6057 QualType CondType = Cond.get()->getType(); 6058 const auto *CondVT = CondType->castAs<VectorType>(); 6059 QualType CondElementTy = CondVT->getElementType(); 6060 unsigned CondElementCount = CondVT->getNumElements(); 6061 QualType LHSType = LHS.get()->getType(); 6062 const auto *LHSVT = LHSType->getAs<VectorType>(); 6063 QualType RHSType = RHS.get()->getType(); 6064 const auto *RHSVT = RHSType->getAs<VectorType>(); 6065 6066 QualType ResultType; 6067 6068 6069 if (LHSVT && RHSVT) { 6070 if (isa<ExtVectorType>(CondVT) != isa<ExtVectorType>(LHSVT)) { 6071 Diag(QuestionLoc, diag::err_conditional_vector_cond_result_mismatch) 6072 << /*isExtVector*/ isa<ExtVectorType>(CondVT); 6073 return {}; 6074 } 6075 6076 // If both are vector types, they must be the same type. 6077 if (!Context.hasSameType(LHSType, RHSType)) { 6078 Diag(QuestionLoc, diag::err_conditional_vector_mismatched) 6079 << LHSType << RHSType; 6080 return {}; 6081 } 6082 ResultType = LHSType; 6083 } else if (LHSVT || RHSVT) { 6084 ResultType = CheckVectorOperands( 6085 LHS, RHS, QuestionLoc, /*isCompAssign*/ false, /*AllowBothBool*/ true, 6086 /*AllowBoolConversions*/ false); 6087 if (ResultType.isNull()) 6088 return {}; 6089 } else { 6090 // Both are scalar. 6091 QualType ResultElementTy; 6092 LHSType = LHSType.getCanonicalType().getUnqualifiedType(); 6093 RHSType = RHSType.getCanonicalType().getUnqualifiedType(); 6094 6095 if (Context.hasSameType(LHSType, RHSType)) 6096 ResultElementTy = LHSType; 6097 else 6098 ResultElementTy = 6099 UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional); 6100 6101 if (ResultElementTy->isEnumeralType()) { 6102 Diag(QuestionLoc, diag::err_conditional_vector_operand_type) 6103 << ResultElementTy; 6104 return {}; 6105 } 6106 if (CondType->isExtVectorType()) 6107 ResultType = 6108 Context.getExtVectorType(ResultElementTy, CondVT->getNumElements()); 6109 else 6110 ResultType = Context.getVectorType( 6111 ResultElementTy, CondVT->getNumElements(), VectorType::GenericVector); 6112 6113 LHS = ImpCastExprToType(LHS.get(), ResultType, CK_VectorSplat); 6114 RHS = ImpCastExprToType(RHS.get(), ResultType, CK_VectorSplat); 6115 } 6116 6117 assert(!ResultType.isNull() && ResultType->isVectorType() &&((void)0) 6118 (!CondType->isExtVectorType() || ResultType->isExtVectorType()) &&((void)0) 6119 "Result should have been a vector type")((void)0); 6120 auto *ResultVectorTy = ResultType->castAs<VectorType>(); 6121 QualType ResultElementTy = ResultVectorTy->getElementType(); 6122 unsigned ResultElementCount = ResultVectorTy->getNumElements(); 6123 6124 if (ResultElementCount != CondElementCount) { 6125 Diag(QuestionLoc, diag::err_conditional_vector_size) << CondType 6126 << ResultType; 6127 return {}; 6128 } 6129 6130 if (Context.getTypeSize(ResultElementTy) != 6131 Context.getTypeSize(CondElementTy)) { 6132 Diag(QuestionLoc, diag::err_conditional_vector_element_size) << CondType 6133 << ResultType; 6134 return {}; 6135 } 6136 6137 return ResultType; 6138} 6139 6140/// Check the operands of ?: under C++ semantics. 6141/// 6142/// See C++ [expr.cond]. Note that LHS is never null, even for the GNU x ?: y 6143/// extension. In this case, LHS == Cond. (But they're not aliases.) 6144/// 6145/// This function also implements GCC's vector extension and the 6146/// OpenCL/ext_vector_type extension for conditionals. The vector extensions 6147/// permit the use of a?b:c where the type of a is that of a integer vector with 6148/// the same number of elements and size as the vectors of b and c. If one of 6149/// either b or c is a scalar it is implicitly converted to match the type of 6150/// the vector. Otherwise the expression is ill-formed. If both b and c are 6151/// scalars, then b and c are checked and converted to the type of a if 6152/// possible. 6153/// 6154/// The expressions are evaluated differently for GCC's and OpenCL's extensions. 6155/// For the GCC extension, the ?: operator is evaluated as 6156/// (a[0] != 0 ? b[0] : c[0], .. , a[n] != 0 ? b[n] : c[n]). 6157/// For the OpenCL extensions, the ?: operator is evaluated as 6158/// (most-significant-bit-set(a[0]) ? b[0] : c[0], .. , 6159/// most-significant-bit-set(a[n]) ? b[n] : c[n]). 6160QualType Sema::CXXCheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, 6161 ExprResult &RHS, ExprValueKind &VK, 6162 ExprObjectKind &OK, 6163 SourceLocation QuestionLoc) { 6164 // FIXME: Handle C99's complex types, block pointers and Obj-C++ interface 6165 // pointers. 6166 6167 // Assume r-value. 6168 VK = VK_PRValue; 6169 OK = OK_Ordinary; 6170 bool IsVectorConditional = 6171 isValidVectorForConditionalCondition(Context, Cond.get()->getType()); 6172 6173 // C++11 [expr.cond]p1 6174 // The first expression is contextually converted to bool. 6175 if (!Cond.get()->isTypeDependent()) { 6176 ExprResult CondRes = IsVectorConditional 6177 ? DefaultFunctionArrayLvalueConversion(Cond.get()) 6178 : CheckCXXBooleanCondition(Cond.get()); 6179 if (CondRes.isInvalid()) 6180 return QualType(); 6181 Cond = CondRes; 6182 } else { 6183 // To implement C++, the first expression typically doesn't alter the result 6184 // type of the conditional, however the GCC compatible vector extension 6185 // changes the result type to be that of the conditional. Since we cannot 6186 // know if this is a vector extension here, delay the conversion of the 6187 // LHS/RHS below until later. 6188 return Context.DependentTy; 6189 } 6190 6191 6192 // Either of the arguments dependent? 6193 if (LHS.get()->isTypeDependent() || RHS.get()->isTypeDependent()) 6194 return Context.DependentTy; 6195 6196 // C++11 [expr.cond]p2 6197 // If either the second or the third operand has type (cv) void, ... 6198 QualType LTy = LHS.get()->getType(); 6199 QualType RTy = RHS.get()->getType(); 6200 bool LVoid = LTy->isVoidType(); 6201 bool RVoid = RTy->isVoidType(); 6202 if (LVoid || RVoid) { 6203 // ... one of the following shall hold: 6204 // -- The second or the third operand (but not both) is a (possibly 6205 // parenthesized) throw-expression; the result is of the type 6206 // and value category of the other. 6207 bool LThrow = isa<CXXThrowExpr>(LHS.get()->IgnoreParenImpCasts()); 6208 bool RThrow = isa<CXXThrowExpr>(RHS.get()->IgnoreParenImpCasts()); 6209 6210 // Void expressions aren't legal in the vector-conditional expressions. 6211 if (IsVectorConditional) { 6212 SourceRange DiagLoc = 6213 LVoid ? LHS.get()->getSourceRange() : RHS.get()->getSourceRange(); 6214 bool IsThrow = LVoid ? LThrow : RThrow; 6215 Diag(DiagLoc.getBegin(), diag::err_conditional_vector_has_void) 6216 << DiagLoc << IsThrow; 6217 return QualType(); 6218 } 6219 6220 if (LThrow != RThrow) { 6221 Expr *NonThrow = LThrow ? RHS.get() : LHS.get(); 6222 VK = NonThrow->getValueKind(); 6223 // DR (no number yet): the result is a bit-field if the 6224 // non-throw-expression operand is a bit-field. 6225 OK = NonThrow->getObjectKind(); 6226 return NonThrow->getType(); 6227 } 6228 6229 // -- Both the second and third operands have type void; the result is of 6230 // type void and is a prvalue. 6231 if (LVoid && RVoid) 6232 return Context.VoidTy; 6233 6234 // Neither holds, error. 6235 Diag(QuestionLoc, diag::err_conditional_void_nonvoid) 6236 << (LVoid ? RTy : LTy) << (LVoid ? 0 : 1) 6237 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6238 return QualType(); 6239 } 6240 6241 // Neither is void. 6242 if (IsVectorConditional) 6243 return CheckVectorConditionalTypes(Cond, LHS, RHS, QuestionLoc); 6244 6245 // C++11 [expr.cond]p3 6246 // Otherwise, if the second and third operand have different types, and 6247 // either has (cv) class type [...] an attempt is made to convert each of 6248 // those operands to the type of the other. 6249 if (!Context.hasSameType(LTy, RTy) && 6250 (LTy->isRecordType() || RTy->isRecordType())) { 6251 // These return true if a single direction is already ambiguous. 6252 QualType L2RType, R2LType; 6253 bool HaveL2R, HaveR2L; 6254 if (TryClassUnification(*this, LHS.get(), RHS.get(), QuestionLoc, HaveL2R, L2RType)) 6255 return QualType(); 6256 if (TryClassUnification(*this, RHS.get(), LHS.get(), QuestionLoc, HaveR2L, R2LType)) 6257 return QualType(); 6258 6259 // If both can be converted, [...] the program is ill-formed. 6260 if (HaveL2R && HaveR2L) { 6261 Diag(QuestionLoc, diag::err_conditional_ambiguous) 6262 << LTy << RTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6263 return QualType(); 6264 } 6265 6266 // If exactly one conversion is possible, that conversion is applied to 6267 // the chosen operand and the converted operands are used in place of the 6268 // original operands for the remainder of this section. 6269 if (HaveL2R) { 6270 if (ConvertForConditional(*this, LHS, L2RType) || LHS.isInvalid()) 6271 return QualType(); 6272 LTy = LHS.get()->getType(); 6273 } else if (HaveR2L) { 6274 if (ConvertForConditional(*this, RHS, R2LType) || RHS.isInvalid()) 6275 return QualType(); 6276 RTy = RHS.get()->getType(); 6277 } 6278 } 6279 6280 // C++11 [expr.cond]p3 6281 // if both are glvalues of the same value category and the same type except 6282 // for cv-qualification, an attempt is made to convert each of those 6283 // operands to the type of the other. 6284 // FIXME: 6285 // Resolving a defect in P0012R1: we extend this to cover all cases where 6286 // one of the operands is reference-compatible with the other, in order 6287 // to support conditionals between functions differing in noexcept. This 6288 // will similarly cover difference in array bounds after P0388R4. 6289 // FIXME: If LTy and RTy have a composite pointer type, should we convert to 6290 // that instead? 6291 ExprValueKind LVK = LHS.get()->getValueKind(); 6292 ExprValueKind RVK = RHS.get()->getValueKind(); 6293 if (!Context.hasSameType(LTy, RTy) && LVK == RVK && LVK != VK_PRValue) { 6294 // DerivedToBase was already handled by the class-specific case above. 6295 // FIXME: Should we allow ObjC conversions here? 6296 const ReferenceConversions AllowedConversions = 6297 ReferenceConversions::Qualification | 6298 ReferenceConversions::NestedQualification | 6299 ReferenceConversions::Function; 6300 6301 ReferenceConversions RefConv; 6302 if (CompareReferenceRelationship(QuestionLoc, LTy, RTy, &RefConv) == 6303 Ref_Compatible && 6304 !(RefConv & ~AllowedConversions) && 6305 // [...] subject to the constraint that the reference must bind 6306 // directly [...] 6307 !RHS.get()->refersToBitField() && !RHS.get()->refersToVectorElement()) { 6308 RHS = ImpCastExprToType(RHS.get(), LTy, CK_NoOp, RVK); 6309 RTy = RHS.get()->getType(); 6310 } else if (CompareReferenceRelationship(QuestionLoc, RTy, LTy, &RefConv) == 6311 Ref_Compatible && 6312 !(RefConv & ~AllowedConversions) && 6313 !LHS.get()->refersToBitField() && 6314 !LHS.get()->refersToVectorElement()) { 6315 LHS = ImpCastExprToType(LHS.get(), RTy, CK_NoOp, LVK); 6316 LTy = LHS.get()->getType(); 6317 } 6318 } 6319 6320 // C++11 [expr.cond]p4 6321 // If the second and third operands are glvalues of the same value 6322 // category and have the same type, the result is of that type and 6323 // value category and it is a bit-field if the second or the third 6324 // operand is a bit-field, or if both are bit-fields. 6325 // We only extend this to bitfields, not to the crazy other kinds of 6326 // l-values. 6327 bool Same = Context.hasSameType(LTy, RTy); 6328 if (Same && LVK == RVK && LVK != VK_PRValue && 6329 LHS.get()->isOrdinaryOrBitFieldObject() && 6330 RHS.get()->isOrdinaryOrBitFieldObject()) { 6331 VK = LHS.get()->getValueKind(); 6332 if (LHS.get()->getObjectKind() == OK_BitField || 6333 RHS.get()->getObjectKind() == OK_BitField) 6334 OK = OK_BitField; 6335 6336 // If we have function pointer types, unify them anyway to unify their 6337 // exception specifications, if any. 6338 if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { 6339 Qualifiers Qs = LTy.getQualifiers(); 6340 LTy = FindCompositePointerType(QuestionLoc, LHS, RHS, 6341 /*ConvertArgs*/false); 6342 LTy = Context.getQualifiedType(LTy, Qs); 6343 6344 assert(!LTy.isNull() && "failed to find composite pointer type for "((void)0) 6345 "canonically equivalent function ptr types")((void)0); 6346 assert(Context.hasSameType(LTy, RTy) && "bad composite pointer type")((void)0); 6347 } 6348 6349 return LTy; 6350 } 6351 6352 // C++11 [expr.cond]p5 6353 // Otherwise, the result is a prvalue. If the second and third operands 6354 // do not have the same type, and either has (cv) class type, ... 6355 if (!Same && (LTy->isRecordType() || RTy->isRecordType())) { 6356 // ... overload resolution is used to determine the conversions (if any) 6357 // to be applied to the operands. If the overload resolution fails, the 6358 // program is ill-formed. 6359 if (FindConditionalOverload(*this, LHS, RHS, QuestionLoc)) 6360 return QualType(); 6361 } 6362 6363 // C++11 [expr.cond]p6 6364 // Lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard 6365 // conversions are performed on the second and third operands. 6366 LHS = DefaultFunctionArrayLvalueConversion(LHS.get()); 6367 RHS = DefaultFunctionArrayLvalueConversion(RHS.get()); 6368 if (LHS.isInvalid() || RHS.isInvalid()) 6369 return QualType(); 6370 LTy = LHS.get()->getType(); 6371 RTy = RHS.get()->getType(); 6372 6373 // After those conversions, one of the following shall hold: 6374 // -- The second and third operands have the same type; the result 6375 // is of that type. If the operands have class type, the result 6376 // is a prvalue temporary of the result type, which is 6377 // copy-initialized from either the second operand or the third 6378 // operand depending on the value of the first operand. 6379 if (Context.getCanonicalType(LTy) == Context.getCanonicalType(RTy)) { 6380 if (LTy->isRecordType()) { 6381 // The operands have class type. Make a temporary copy. 6382 InitializedEntity Entity = InitializedEntity::InitializeTemporary(LTy); 6383 6384 ExprResult LHSCopy = PerformCopyInitialization(Entity, 6385 SourceLocation(), 6386 LHS); 6387 if (LHSCopy.isInvalid()) 6388 return QualType(); 6389 6390 ExprResult RHSCopy = PerformCopyInitialization(Entity, 6391 SourceLocation(), 6392 RHS); 6393 if (RHSCopy.isInvalid()) 6394 return QualType(); 6395 6396 LHS = LHSCopy; 6397 RHS = RHSCopy; 6398 } 6399 6400 // If we have function pointer types, unify them anyway to unify their 6401 // exception specifications, if any. 6402 if (LTy->isFunctionPointerType() || LTy->isMemberFunctionPointerType()) { 6403 LTy = FindCompositePointerType(QuestionLoc, LHS, RHS); 6404 assert(!LTy.isNull() && "failed to find composite pointer type for "((void)0) 6405 "canonically equivalent function ptr types")((void)0); 6406 } 6407 6408 return LTy; 6409 } 6410 6411 // Extension: conditional operator involving vector types. 6412 if (LTy->isVectorType() || RTy->isVectorType()) 6413 return CheckVectorOperands(LHS, RHS, QuestionLoc, /*isCompAssign*/false, 6414 /*AllowBothBool*/true, 6415 /*AllowBoolConversions*/false); 6416 6417 // -- The second and third operands have arithmetic or enumeration type; 6418 // the usual arithmetic conversions are performed to bring them to a 6419 // common type, and the result is of that type. 6420 if (LTy->isArithmeticType() && RTy->isArithmeticType()) { 6421 QualType ResTy = 6422 UsualArithmeticConversions(LHS, RHS, QuestionLoc, ACK_Conditional); 6423 if (LHS.isInvalid() || RHS.isInvalid()) 6424 return QualType(); 6425 if (ResTy.isNull()) { 6426 Diag(QuestionLoc, 6427 diag::err_typecheck_cond_incompatible_operands) << LTy << RTy 6428 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6429 return QualType(); 6430 } 6431 6432 LHS = ImpCastExprToType(LHS.get(), ResTy, PrepareScalarCast(LHS, ResTy)); 6433 RHS = ImpCastExprToType(RHS.get(), ResTy, PrepareScalarCast(RHS, ResTy)); 6434 6435 return ResTy; 6436 } 6437 6438 // -- The second and third operands have pointer type, or one has pointer 6439 // type and the other is a null pointer constant, or both are null 6440 // pointer constants, at least one of which is non-integral; pointer 6441 // conversions and qualification conversions are performed to bring them 6442 // to their composite pointer type. The result is of the composite 6443 // pointer type. 6444 // -- The second and third operands have pointer to member type, or one has 6445 // pointer to member type and the other is a null pointer constant; 6446 // pointer to member conversions and qualification conversions are 6447 // performed to bring them to a common type, whose cv-qualification 6448 // shall match the cv-qualification of either the second or the third 6449 // operand. The result is of the common type. 6450 QualType Composite = FindCompositePointerType(QuestionLoc, LHS, RHS); 6451 if (!Composite.isNull()) 6452 return Composite; 6453 6454 // Similarly, attempt to find composite type of two objective-c pointers. 6455 Composite = FindCompositeObjCPointerType(LHS, RHS, QuestionLoc); 6456 if (LHS.isInvalid() || RHS.isInvalid()) 6457 return QualType(); 6458 if (!Composite.isNull()) 6459 return Composite; 6460 6461 // Check if we are using a null with a non-pointer type. 6462 if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) 6463 return QualType(); 6464 6465 Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) 6466 << LHS.get()->getType() << RHS.get()->getType() 6467 << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); 6468 return QualType(); 6469} 6470 6471static FunctionProtoType::ExceptionSpecInfo 6472mergeExceptionSpecs(Sema &S, FunctionProtoType::ExceptionSpecInfo ESI1, 6473 FunctionProtoType::ExceptionSpecInfo ESI2, 6474 SmallVectorImpl<QualType> &ExceptionTypeStorage) { 6475 ExceptionSpecificationType EST1 = ESI1.Type; 6476 ExceptionSpecificationType EST2 = ESI2.Type; 6477 6478 // If either of them can throw anything, that is the result. 6479 if (EST1 == EST_None) return ESI1; 6480 if (EST2 == EST_None) return ESI2; 6481 if (EST1 == EST_MSAny) return ESI1; 6482 if (EST2 == EST_MSAny) return ESI2; 6483 if (EST1 == EST_NoexceptFalse) return ESI1; 6484 if (EST2 == EST_NoexceptFalse) return ESI2; 6485 6486 // If either of them is non-throwing, the result is the other. 6487 if (EST1 == EST_NoThrow) return ESI2; 6488 if (EST2 == EST_NoThrow) return ESI1; 6489 if (EST1 == EST_DynamicNone) return ESI2; 6490 if (EST2 == EST_DynamicNone) return ESI1; 6491 if (EST1 == EST_BasicNoexcept) return ESI2; 6492 if (EST2 == EST_BasicNoexcept) return ESI1; 6493 if (EST1 == EST_NoexceptTrue) return ESI2; 6494 if (EST2 == EST_NoexceptTrue) return ESI1; 6495 6496 // If we're left with value-dependent computed noexcept expressions, we're 6497 // stuck. Before C++17, we can just drop the exception specification entirely, 6498 // since it's not actually part of the canonical type. And this should never 6499 // happen in C++17, because it would mean we were computing the composite 6500 // pointer type of dependent types, which should never happen. 6501 if (EST1 == EST_DependentNoexcept || EST2 == EST_DependentNoexcept) { 6502 assert(!S.getLangOpts().CPlusPlus17 &&((void)0) 6503 "computing composite pointer type of dependent types")((void)0); 6504 return FunctionProtoType::ExceptionSpecInfo(); 6505 } 6506 6507 // Switch over the possibilities so that people adding new values know to 6508 // update this function. 6509 switch (EST1) { 6510 case EST_None: 6511 case EST_DynamicNone: 6512 case EST_MSAny: 6513 case EST_BasicNoexcept: 6514 case EST_DependentNoexcept: 6515 case EST_NoexceptFalse: 6516 case EST_NoexceptTrue: 6517 case EST_NoThrow: 6518 llvm_unreachable("handled above")__builtin_unreachable(); 6519 6520 case EST_Dynamic: { 6521 // This is the fun case: both exception specifications are dynamic. Form 6522 // the union of the two lists. 6523 assert(EST2 == EST_Dynamic && "other cases should already be handled")((void)0); 6524 llvm::SmallPtrSet<QualType, 8> Found; 6525 for (auto &Exceptions : {ESI1.Exceptions, ESI2.Exceptions}) 6526 for (QualType E : Exceptions) 6527 if (Found.insert(S.Context.getCanonicalType(E)).second) 6528 ExceptionTypeStorage.push_back(E); 6529 6530 FunctionProtoType::ExceptionSpecInfo Result(EST_Dynamic); 6531 Result.Exceptions = ExceptionTypeStorage; 6532 return Result; 6533 } 6534 6535 case EST_Unevaluated: 6536 case EST_Uninstantiated: 6537 case EST_Unparsed: 6538 llvm_unreachable("shouldn't see unresolved exception specifications here")__builtin_unreachable(); 6539 } 6540 6541 llvm_unreachable("invalid ExceptionSpecificationType")__builtin_unreachable(); 6542} 6543 6544/// Find a merged pointer type and convert the two expressions to it. 6545/// 6546/// This finds the composite pointer type for \p E1 and \p E2 according to 6547/// C++2a [expr.type]p3. It converts both expressions to this type and returns 6548/// it. It does not emit diagnostics (FIXME: that's not true if \p ConvertArgs 6549/// is \c true). 6550/// 6551/// \param Loc The location of the operator requiring these two expressions to 6552/// be converted to the composite pointer type. 6553/// 6554/// \param ConvertArgs If \c false, do not convert E1 and E2 to the target type. 6555QualType Sema::FindCompositePointerType(SourceLocation Loc, 6556 Expr *&E1, Expr *&E2, 6557 bool ConvertArgs) { 6558 assert(getLangOpts().CPlusPlus && "This function assumes C++")((void)0); 6559 6560 // C++1z [expr]p14: 6561 // The composite pointer type of two operands p1 and p2 having types T1 6562 // and T2 6563 QualType T1 = E1->getType(), T2 = E2->getType(); 6564 6565 // where at least one is a pointer or pointer to member type or 6566 // std::nullptr_t is: 6567 bool T1IsPointerLike = T1->isAnyPointerType() || T1->isMemberPointerType() || 6568 T1->isNullPtrType(); 6569 bool T2IsPointerLike = T2->isAnyPointerType() || T2->isMemberPointerType() || 6570 T2->isNullPtrType(); 6571 if (!T1IsPointerLike && !T2IsPointerLike) 6572 return QualType(); 6573 6574 // - if both p1 and p2 are null pointer constants, std::nullptr_t; 6575 // This can't actually happen, following the standard, but we also use this 6576 // to implement the end of [expr.conv], which hits this case. 6577 // 6578 // - if either p1 or p2 is a null pointer constant, T2 or T1, respectively; 6579 if (T1IsPointerLike && 6580 E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 6581 if (ConvertArgs) 6582 E2 = ImpCastExprToType(E2, T1, T1->isMemberPointerType() 6583 ? CK_NullToMemberPointer 6584 : CK_NullToPointer).get(); 6585 return T1; 6586 } 6587 if (T2IsPointerLike && 6588 E1->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { 6589 if (ConvertArgs) 6590 E1 = ImpCastExprToType(E1, T2, T2->isMemberPointerType() 6591 ? CK_NullToMemberPointer 6592 : CK_NullToPointer).get(); 6593 return T2; 6594 } 6595 6596 // Now both have to be pointers or member pointers. 6597 if (!T1IsPointerLike || !T2IsPointerLike) 6598 return QualType(); 6599 assert(!T1->isNullPtrType() && !T2->isNullPtrType() &&((void)0) 6600 "nullptr_t should be a null pointer constant")((void)0); 6601 6602 struct Step { 6603 enum Kind { Pointer, ObjCPointer, MemberPointer, Array } K; 6604 // Qualifiers to apply under the step kind. 6605 Qualifiers Quals; 6606 /// The class for a pointer-to-member; a constant array type with a bound 6607 /// (if any) for an array. 6608 const Type *ClassOrBound; 6609 6610 Step(Kind K, const Type *ClassOrBound = nullptr) 6611 : K(K), Quals(), ClassOrBound(ClassOrBound) {} 6612 QualType rebuild(ASTContext &Ctx, QualType T) const { 6613 T = Ctx.getQualifiedType(T, Quals); 6614 switch (K) { 6615 case Pointer: 6616 return Ctx.getPointerType(T); 6617 case MemberPointer: 6618 return Ctx.getMemberPointerType(T, ClassOrBound); 6619 case ObjCPointer: 6620 return Ctx.getObjCObjectPointerType(T); 6621 case Array: 6622 if (auto *CAT = cast_or_null<ConstantArrayType>(ClassOrBound)) 6623 return Ctx.getConstantArrayType(T, CAT->getSize(), nullptr, 6624 ArrayType::Normal, 0); 6625 else 6626 return Ctx.getIncompleteArrayType(T, ArrayType::Normal, 0); 6627 } 6628 llvm_unreachable("unknown step kind")__builtin_unreachable(); 6629 } 6630 }; 6631 6632 SmallVector<Step, 8> Steps; 6633 6634 // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1 6635 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3), 6636 // the cv-combined type of T1 and T2 or the cv-combined type of T2 and T1, 6637 // respectively; 6638 // - if T1 is "pointer to member of C1 of type cv1 U1" and T2 is "pointer 6639 // to member of C2 of type cv2 U2" for some non-function type U, where 6640 // C1 is reference-related to C2 or C2 is reference-related to C1, the 6641 // cv-combined type of T2 and T1 or the cv-combined type of T1 and T2, 6642 // respectively; 6643 // - if T1 and T2 are similar types (4.5), the cv-combined type of T1 and 6644 // T2; 6645 // 6646 // Dismantle T1 and T2 to simultaneously determine whether they are similar 6647 // and to prepare to form the cv-combined type if so. 6648 QualType Composite1 = T1; 6649 QualType Composite2 = T2; 6650 unsigned NeedConstBefore = 0; 6651 while (true) { 6652 assert(!Composite1.isNull() && !Composite2.isNull())((void)0); 6653 6654 Qualifiers Q1, Q2; 6655 Composite1 = Context.getUnqualifiedArrayType(Composite1, Q1); 6656 Composite2 = Context.getUnqualifiedArrayType(Composite2, Q2); 6657 6658 // Top-level qualifiers are ignored. Merge at all lower levels. 6659 if (!Steps.empty()) { 6660 // Find the qualifier union: (approximately) the unique minimal set of 6661 // qualifiers that is compatible with both types. 6662 Qualifiers Quals = Qualifiers::fromCVRUMask(Q1.getCVRUQualifiers() | 6663 Q2.getCVRUQualifiers()); 6664 6665 // Under one level of pointer or pointer-to-member, we can change to an 6666 // unambiguous compatible address space. 6667 if (Q1.getAddressSpace() == Q2.getAddressSpace()) { 6668 Quals.setAddressSpace(Q1.getAddressSpace()); 6669 } else if (Steps.size() == 1) { 6670 bool MaybeQ1 = Q1.isAddressSpaceSupersetOf(Q2); 6671 bool MaybeQ2 = Q2.isAddressSpaceSupersetOf(Q1); 6672 if (MaybeQ1 == MaybeQ2) 6673 return QualType(); // No unique best address space. 6674 Quals.setAddressSpace(MaybeQ1 ? Q1.getAddressSpace() 6675 : Q2.getAddressSpace()); 6676 } else { 6677 return QualType(); 6678 } 6679 6680 // FIXME: In C, we merge __strong and none to __strong at the top level. 6681 if (Q1.getObjCGCAttr() == Q2.getObjCGCAttr()) 6682 Quals.setObjCGCAttr(Q1.getObjCGCAttr()); 6683 else if (T1->isVoidPointerType() || T2->isVoidPointerType()) 6684 assert(Steps.size() == 1)((void)0); 6685 else 6686 return QualType(); 6687 6688 // Mismatched lifetime qualifiers never compatibly include each other. 6689 if (Q1.getObjCLifetime() == Q2.getObjCLifetime()) 6690 Quals.setObjCLifetime(Q1.getObjCLifetime()); 6691 else if (T1->isVoidPointerType() || T2->isVoidPointerType()) 6692 assert(Steps.size() == 1)((void)0); 6693 else 6694 return QualType(); 6695 6696 Steps.back().Quals = Quals; 6697 if (Q1 != Quals || Q2 != Quals) 6698 NeedConstBefore = Steps.size() - 1; 6699 } 6700 6701 // FIXME: Can we unify the following with UnwrapSimilarTypes? 6702 const PointerType *Ptr1, *Ptr2; 6703 if ((Ptr1 = Composite1->getAs<PointerType>()) && 6704 (Ptr2 = Composite2->getAs<PointerType>())) { 6705 Composite1 = Ptr1->getPointeeType(); 6706 Composite2 = Ptr2->getPointeeType(); 6707 Steps.emplace_back(Step::Pointer); 6708 continue; 6709 } 6710 6711 const ObjCObjectPointerType *ObjPtr1, *ObjPtr2; 6712 if ((ObjPtr1 = Composite1->getAs<ObjCObjectPointerType>()) && 6713 (ObjPtr2 = Composite2->getAs<ObjCObjectPointerType>())) { 6714 Composite1 = ObjPtr1->getPointeeType(); 6715 Composite2 = ObjPtr2->getPointeeType(); 6716 Steps.emplace_back(Step::ObjCPointer); 6717 continue; 6718 } 6719 6720 const MemberPointerType *MemPtr1, *MemPtr2; 6721 if ((MemPtr1 = Composite1->getAs<MemberPointerType>()) && 6722 (MemPtr2 = Composite2->getAs<MemberPointerType>())) { 6723 Composite1 = MemPtr1->getPointeeType(); 6724 Composite2 = MemPtr2->getPointeeType(); 6725 6726 // At the top level, we can perform a base-to-derived pointer-to-member 6727 // conversion: 6728 // 6729 // - [...] where C1 is reference-related to C2 or C2 is 6730 // reference-related to C1 6731 // 6732 // (Note that the only kinds of reference-relatedness in scope here are 6733 // "same type or derived from".) At any other level, the class must 6734 // exactly match. 6735 const Type *Class = nullptr; 6736 QualType Cls1(MemPtr1->getClass(), 0); 6737 QualType Cls2(MemPtr2->getClass(), 0); 6738 if (Context.hasSameType(Cls1, Cls2)) 6739 Class = MemPtr1->getClass(); 6740 else if (Steps.empty()) 6741 Class = IsDerivedFrom(Loc, Cls1, Cls2) ? MemPtr1->getClass() : 6742 IsDerivedFrom(Loc, Cls2, Cls1) ? MemPtr2->getClass() : nullptr; 6743 if (!Class) 6744 return QualType(); 6745 6746 Steps.emplace_back(Step::MemberPointer, Class); 6747 continue; 6748 } 6749 6750 // Special case: at the top level, we can decompose an Objective-C pointer 6751 // and a 'cv void *'. Unify the qualifiers. 6752 if (Steps.empty() && ((Composite1->isVoidPointerType() && 6753 Composite2->isObjCObjectPointerType()) || 6754 (Composite1->isObjCObjectPointerType() && 6755 Composite2->isVoidPointerType()))) { 6756 Composite1 = Composite1->getPointeeType(); 6757 Composite2 = Composite2->getPointeeType(); 6758 Steps.emplace_back(Step::Pointer); 6759 continue; 6760 } 6761 6762 // FIXME: arrays 6763 6764 // FIXME: block pointer types? 6765 6766 // Cannot unwrap any more types. 6767 break; 6768 } 6769 6770 // - if T1 or T2 is "pointer to noexcept function" and the other type is 6771 // "pointer to function", where the function types are otherwise the same, 6772 // "pointer to function"; 6773 // - if T1 or T2 is "pointer to member of C1 of type function", the other 6774 // type is "pointer to member of C2 of type noexcept function", and C1 6775 // is reference-related to C2 or C2 is reference-related to C1, where 6776 // the function types are otherwise the same, "pointer to member of C2 of 6777 // type function" or "pointer to member of C1 of type function", 6778 // respectively; 6779 // 6780 // We also support 'noreturn' here, so as a Clang extension we generalize the 6781 // above to: 6782 // 6783 // - [Clang] If T1 and T2 are both of type "pointer to function" or 6784 // "pointer to member function" and the pointee types can be unified 6785 // by a function pointer conversion, that conversion is applied 6786 // before checking the following rules. 6787 // 6788 // We've already unwrapped down to the function types, and we want to merge 6789 // rather than just convert, so do this ourselves rather than calling 6790 // IsFunctionConversion. 6791 // 6792 // FIXME: In order to match the standard wording as closely as possible, we 6793 // currently only do this under a single level of pointers. Ideally, we would 6794 // allow this in general, and set NeedConstBefore to the relevant depth on 6795 // the side(s) where we changed anything. If we permit that, we should also 6796 // consider this conversion when determining type similarity and model it as 6797 // a qualification conversion. 6798 if (Steps.size() == 1) { 6799 if (auto *FPT1 = Composite1->getAs<FunctionProtoType>()) { 6800 if (auto *FPT2 = Composite2->getAs<FunctionProtoType>()) { 6801 FunctionProtoType::ExtProtoInfo EPI1 = FPT1->getExtProtoInfo(); 6802 FunctionProtoType::ExtProtoInfo EPI2 = FPT2->getExtProtoInfo(); 6803 6804 // The result is noreturn if both operands are. 6805 bool Noreturn = 6806 EPI1.ExtInfo.getNoReturn() && EPI2.ExtInfo.getNoReturn(); 6807 EPI1.ExtInfo = EPI1.ExtInfo.withNoReturn(Noreturn); 6808 EPI2.ExtInfo = EPI2.ExtInfo.withNoReturn(Noreturn); 6809 6810 // The result is nothrow if both operands are. 6811 SmallVector<QualType, 8> ExceptionTypeStorage; 6812 EPI1.ExceptionSpec = EPI2.ExceptionSpec = 6813 mergeExceptionSpecs(*this, EPI1.ExceptionSpec, EPI2.ExceptionSpec, 6814 ExceptionTypeStorage); 6815 6816 Composite1 = Context.getFunctionType(FPT1->getReturnType(), 6817 FPT1->getParamTypes(), EPI1); 6818 Composite2 = Context.getFunctionType(FPT2->getReturnType(), 6819 FPT2->getParamTypes(), EPI2); 6820 } 6821 } 6822 } 6823 6824 // There are some more conversions we can perform under exactly one pointer. 6825 if (Steps.size() == 1 && Steps.front().K == Step::Pointer && 6826 !Context.hasSameType(Composite1, Composite2)) { 6827 // - if T1 or T2 is "pointer to cv1 void" and the other type is 6828 // "pointer to cv2 T", where T is an object type or void, 6829 // "pointer to cv12 void", where cv12 is the union of cv1 and cv2; 6830 if (Composite1->isVoidType() && Composite2->isObjectType()) 6831 Composite2 = Composite1; 6832 else if (Composite2->isVoidType() && Composite1->isObjectType()) 6833 Composite1 = Composite2; 6834 // - if T1 is "pointer to cv1 C1" and T2 is "pointer to cv2 C2", where C1 6835 // is reference-related to C2 or C2 is reference-related to C1 (8.6.3), 6836 // the cv-combined type of T1 and T2 or the cv-combined type of T2 and 6837 // T1, respectively; 6838 // 6839 // The "similar type" handling covers all of this except for the "T1 is a 6840 // base class of T2" case in the definition of reference-related. 6841 else if (IsDerivedFrom(Loc, Composite1, Composite2)) 6842 Composite1 = Composite2; 6843 else if (IsDerivedFrom(Loc, Composite2, Composite1)) 6844 Composite2 = Composite1; 6845 } 6846 6847 // At this point, either the inner types are the same or we have failed to 6848 // find a composite pointer type. 6849 if (!Context.hasSameType(Composite1, Composite2)) 6850 return QualType(); 6851 6852 // Per C++ [conv.qual]p3, add 'const' to every level before the last 6853 // differing qualifier. 6854 for (unsigned I = 0; I != NeedConstBefore; ++I) 6855 Steps[I].Quals.addConst(); 6856 6857 // Rebuild the composite type. 6858 QualType Composite = Composite1; 6859 for (auto &S : llvm::reverse(Steps)) 6860 Composite = S.rebuild(Context, Composite); 6861 6862 if (ConvertArgs) { 6863 // Convert the expressions to the composite pointer type. 6864 InitializedEntity Entity = 6865 InitializedEntity::InitializeTemporary(Composite); 6866 InitializationKind Kind = 6867 InitializationKind::CreateCopy(Loc, SourceLocation()); 6868 6869 InitializationSequence E1ToC(*this, Entity, Kind, E1); 6870 if (!E1ToC) 6871 return QualType(); 6872 6873 InitializationSequence E2ToC(*this, Entity, Kind, E2); 6874 if (!E2ToC) 6875 return QualType(); 6876 6877 // FIXME: Let the caller know if these fail to avoid duplicate diagnostics. 6878 ExprResult E1Result = E1ToC.Perform(*this, Entity, Kind, E1); 6879 if (E1Result.isInvalid()) 6880 return QualType(); 6881 E1 = E1Result.get(); 6882 6883 ExprResult E2Result = E2ToC.Perform(*this, Entity, Kind, E2); 6884 if (E2Result.isInvalid()) 6885 return QualType(); 6886 E2 = E2Result.get(); 6887 } 6888 6889 return Composite; 6890} 6891 6892ExprResult Sema::MaybeBindToTemporary(Expr *E) { 6893 if (!E) 6894 return ExprError(); 6895 6896 assert(!isa<CXXBindTemporaryExpr>(E) && "Double-bound temporary?")((void)0); 6897 6898 // If the result is a glvalue, we shouldn't bind it. 6899 if (E->isGLValue()) 6900 return E; 6901 6902 // In ARC, calls that return a retainable type can return retained, 6903 // in which case we have to insert a consuming cast. 6904 if (getLangOpts().ObjCAutoRefCount && 6905 E->getType()->isObjCRetainableType()) { 6906 6907 bool ReturnsRetained; 6908 6909 // For actual calls, we compute this by examining the type of the 6910 // called value. 6911 if (CallExpr *Call = dyn_cast<CallExpr>(E)) { 6912 Expr *Callee = Call->getCallee()->IgnoreParens(); 6913 QualType T = Callee->getType(); 6914 6915 if (T == Context.BoundMemberTy) { 6916 // Handle pointer-to-members. 6917 if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(Callee)) 6918 T = BinOp->getRHS()->getType(); 6919 else if (MemberExpr *Mem = dyn_cast<MemberExpr>(Callee)) 6920 T = Mem->getMemberDecl()->getType(); 6921 } 6922 6923 if (const PointerType *Ptr = T->getAs<PointerType>()) 6924 T = Ptr->getPointeeType(); 6925 else if (const BlockPointerType *Ptr = T->getAs<BlockPointerType>()) 6926 T = Ptr->getPointeeType(); 6927 else if (const MemberPointerType *MemPtr = T->getAs<MemberPointerType>()) 6928 T = MemPtr->getPointeeType(); 6929 6930 auto *FTy = T->castAs<FunctionType>(); 6931 ReturnsRetained = FTy->getExtInfo().getProducesResult(); 6932 6933 // ActOnStmtExpr arranges things so that StmtExprs of retainable 6934 // type always produce a +1 object. 6935 } else if (isa<StmtExpr>(E)) { 6936 ReturnsRetained = true; 6937 6938 // We hit this case with the lambda conversion-to-block optimization; 6939 // we don't want any extra casts here. 6940 } else if (isa<CastExpr>(E) && 6941 isa<BlockExpr>(cast<CastExpr>(E)->getSubExpr())) { 6942 return E; 6943 6944 // For message sends and property references, we try to find an 6945 // actual method. FIXME: we should infer retention by selector in 6946 // cases where we don't have an actual method. 6947 } else { 6948 ObjCMethodDecl *D = nullptr; 6949 if (ObjCMessageExpr *Send = dyn_cast<ObjCMessageExpr>(E)) { 6950 D = Send->getMethodDecl(); 6951 } else if (ObjCBoxedExpr *BoxedExpr = dyn_cast<ObjCBoxedExpr>(E)) { 6952 D = BoxedExpr->getBoxingMethod(); 6953 } else if (ObjCArrayLiteral *ArrayLit = dyn_cast<ObjCArrayLiteral>(E)) { 6954 // Don't do reclaims if we're using the zero-element array 6955 // constant. 6956 if (ArrayLit->getNumElements() == 0 && 6957 Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) 6958 return E; 6959 6960 D = ArrayLit->getArrayWithObjectsMethod(); 6961 } else if (ObjCDictionaryLiteral *DictLit 6962 = dyn_cast<ObjCDictionaryLiteral>(E)) { 6963 // Don't do reclaims if we're using the zero-element dictionary 6964 // constant. 6965 if (DictLit->getNumElements() == 0 && 6966 Context.getLangOpts().ObjCRuntime.hasEmptyCollections()) 6967 return E; 6968 6969 D = DictLit->getDictWithObjectsMethod(); 6970 } 6971 6972 ReturnsRetained = (D && D->hasAttr<NSReturnsRetainedAttr>()); 6973 6974 // Don't do reclaims on performSelector calls; despite their 6975 // return type, the invoked method doesn't necessarily actually 6976 // return an object. 6977 if (!ReturnsRetained && 6978 D && D->getMethodFamily() == OMF_performSelector) 6979 return E; 6980 } 6981 6982 // Don't reclaim an object of Class type. 6983 if (!ReturnsRetained && E->getType()->isObjCARCImplicitlyUnretainedType()) 6984 return E; 6985 6986 Cleanup.setExprNeedsCleanups(true); 6987 6988 CastKind ck = (ReturnsRetained ? CK_ARCConsumeObject 6989 : CK_ARCReclaimReturnedObject); 6990 return ImplicitCastExpr::Create(Context, E->getType(), ck, E, nullptr, 6991 VK_PRValue, FPOptionsOverride()); 6992 } 6993 6994 if (E->getType().isDestructedType() == QualType::DK_nontrivial_c_struct) 6995 Cleanup.setExprNeedsCleanups(true); 6996 6997 if (!getLangOpts().CPlusPlus) 6998 return E; 6999 7000 // Search for the base element type (cf. ASTContext::getBaseElementType) with 7001 // a fast path for the common case that the type is directly a RecordType. 7002 const Type *T = Context.getCanonicalType(E->getType().getTypePtr()); 7003 const RecordType *RT = nullptr; 7004 while (!RT) { 7005 switch (T->getTypeClass()) { 7006 case Type::Record: 7007 RT = cast<RecordType>(T); 7008 break; 7009 case Type::ConstantArray: 7010 case Type::IncompleteArray: 7011 case Type::VariableArray: 7012 case Type::DependentSizedArray: 7013 T = cast<ArrayType>(T)->getElementType().getTypePtr(); 7014 break; 7015 default: 7016 return E; 7017 } 7018 } 7019 7020 // That should be enough to guarantee that this type is complete, if we're 7021 // not processing a decltype expression. 7022 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 7023 if (RD->isInvalidDecl() || RD->isDependentContext()) 7024 return E; 7025 7026 bool IsDecltype = ExprEvalContexts.back().ExprContext == 7027 ExpressionEvaluationContextRecord::EK_Decltype; 7028 CXXDestructorDecl *Destructor = IsDecltype ? nullptr : LookupDestructor(RD); 7029 7030 if (Destructor) { 7031 MarkFunctionReferenced(E->getExprLoc(), Destructor); 7032 CheckDestructorAccess(E->getExprLoc(), Destructor, 7033 PDiag(diag::err_access_dtor_temp) 7034 << E->getType()); 7035 if (DiagnoseUseOfDecl(Destructor, E->getExprLoc())) 7036 return ExprError(); 7037 7038 // If destructor is trivial, we can avoid the extra copy. 7039 if (Destructor->isTrivial()) 7040 return E; 7041 7042 // We need a cleanup, but we don't need to remember the temporary. 7043 Cleanup.setExprNeedsCleanups(true); 7044 } 7045 7046 CXXTemporary *Temp = CXXTemporary::Create(Context, Destructor); 7047 CXXBindTemporaryExpr *Bind = CXXBindTemporaryExpr::Create(Context, Temp, E); 7048 7049 if (IsDecltype) 7050 ExprEvalContexts.back().DelayedDecltypeBinds.push_back(Bind); 7051 7052 return Bind; 7053} 7054 7055ExprResult 7056Sema::MaybeCreateExprWithCleanups(ExprResult SubExpr) { 7057 if (SubExpr.isInvalid()) 7058 return ExprError(); 7059 7060 return MaybeCreateExprWithCleanups(SubExpr.get()); 7061} 7062 7063Expr *Sema::MaybeCreateExprWithCleanups(Expr *SubExpr) { 7064 assert(SubExpr && "subexpression can't be null!")((void)0); 7065 7066 CleanupVarDeclMarking(); 7067 7068 unsigned FirstCleanup = ExprEvalContexts.back().NumCleanupObjects; 7069 assert(ExprCleanupObjects.size() >= FirstCleanup)((void)0); 7070 assert(Cleanup.exprNeedsCleanups() ||((void)0) 7071 ExprCleanupObjects.size() == FirstCleanup)((void)0); 7072 if (!Cleanup.exprNeedsCleanups()) 7073 return SubExpr; 7074 7075 auto Cleanups = llvm::makeArrayRef(ExprCleanupObjects.begin() + FirstCleanup, 7076 ExprCleanupObjects.size() - FirstCleanup); 7077 7078 auto *E = ExprWithCleanups::Create( 7079 Context, SubExpr, Cleanup.cleanupsHaveSideEffects(), Cleanups); 7080 DiscardCleanupsInEvaluationContext(); 7081 7082 return E; 7083} 7084 7085Stmt *Sema::MaybeCreateStmtWithCleanups(Stmt *SubStmt) { 7086 assert(SubStmt && "sub-statement can't be null!")((void)0); 7087 7088 CleanupVarDeclMarking(); 7089 7090 if (!Cleanup.exprNeedsCleanups()) 7091 return SubStmt; 7092 7093 // FIXME: In order to attach the temporaries, wrap the statement into 7094 // a StmtExpr; currently this is only used for asm statements. 7095 // This is hacky, either create a new CXXStmtWithTemporaries statement or 7096 // a new AsmStmtWithTemporaries. 7097 CompoundStmt *CompStmt = CompoundStmt::Create( 7098 Context, SubStmt, SourceLocation(), SourceLocation()); 7099 Expr *E = new (Context) 7100 StmtExpr(CompStmt, Context.VoidTy, SourceLocation(), SourceLocation(), 7101 /*FIXME TemplateDepth=*/0); 7102 return MaybeCreateExprWithCleanups(E); 7103} 7104 7105/// Process the expression contained within a decltype. For such expressions, 7106/// certain semantic checks on temporaries are delayed until this point, and 7107/// are omitted for the 'topmost' call in the decltype expression. If the 7108/// topmost call bound a temporary, strip that temporary off the expression. 7109ExprResult Sema::ActOnDecltypeExpression(Expr *E) { 7110 assert(ExprEvalContexts.back().ExprContext ==((void)0) 7111 ExpressionEvaluationContextRecord::EK_Decltype &&((void)0) 7112 "not in a decltype expression")((void)0); 7113 7114 ExprResult Result = CheckPlaceholderExpr(E); 7115 if (Result.isInvalid()) 7116 return ExprError(); 7117 E = Result.get(); 7118 7119 // C++11 [expr.call]p11: 7120 // If a function call is a prvalue of object type, 7121 // -- if the function call is either 7122 // -- the operand of a decltype-specifier, or 7123 // -- the right operand of a comma operator that is the operand of a 7124 // decltype-specifier, 7125 // a temporary object is not introduced for the prvalue. 7126 7127 // Recursively rebuild ParenExprs and comma expressions to strip out the 7128 // outermost CXXBindTemporaryExpr, if any. 7129 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7130 ExprResult SubExpr = ActOnDecltypeExpression(PE->getSubExpr()); 7131 if (SubExpr.isInvalid()) 7132 return ExprError(); 7133 if (SubExpr.get() == PE->getSubExpr()) 7134 return E; 7135 return ActOnParenExpr(PE->getLParen(), PE->getRParen(), SubExpr.get()); 7136 } 7137 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 7138 if (BO->getOpcode() == BO_Comma) { 7139 ExprResult RHS = ActOnDecltypeExpression(BO->getRHS()); 7140 if (RHS.isInvalid()) 7141 return ExprError(); 7142 if (RHS.get() == BO->getRHS()) 7143 return E; 7144 return BinaryOperator::Create(Context, BO->getLHS(), RHS.get(), BO_Comma, 7145 BO->getType(), BO->getValueKind(), 7146 BO->getObjectKind(), BO->getOperatorLoc(), 7147 BO->getFPFeatures(getLangOpts())); 7148 } 7149 } 7150 7151 CXXBindTemporaryExpr *TopBind = dyn_cast<CXXBindTemporaryExpr>(E); 7152 CallExpr *TopCall = TopBind ? dyn_cast<CallExpr>(TopBind->getSubExpr()) 7153 : nullptr; 7154 if (TopCall) 7155 E = TopCall; 7156 else 7157 TopBind = nullptr; 7158 7159 // Disable the special decltype handling now. 7160 ExprEvalContexts.back().ExprContext = 7161 ExpressionEvaluationContextRecord::EK_Other; 7162 7163 Result = CheckUnevaluatedOperand(E); 7164 if (Result.isInvalid()) 7165 return ExprError(); 7166 E = Result.get(); 7167 7168 // In MS mode, don't perform any extra checking of call return types within a 7169 // decltype expression. 7170 if (getLangOpts().MSVCCompat) 7171 return E; 7172 7173 // Perform the semantic checks we delayed until this point. 7174 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeCalls.size(); 7175 I != N; ++I) { 7176 CallExpr *Call = ExprEvalContexts.back().DelayedDecltypeCalls[I]; 7177 if (Call == TopCall) 7178 continue; 7179 7180 if (CheckCallReturnType(Call->getCallReturnType(Context), 7181 Call->getBeginLoc(), Call, Call->getDirectCallee())) 7182 return ExprError(); 7183 } 7184 7185 // Now all relevant types are complete, check the destructors are accessible 7186 // and non-deleted, and annotate them on the temporaries. 7187 for (unsigned I = 0, N = ExprEvalContexts.back().DelayedDecltypeBinds.size(); 7188 I != N; ++I) { 7189 CXXBindTemporaryExpr *Bind = 7190 ExprEvalContexts.back().DelayedDecltypeBinds[I]; 7191 if (Bind == TopBind) 7192 continue; 7193 7194 CXXTemporary *Temp = Bind->getTemporary(); 7195 7196 CXXRecordDecl *RD = 7197 Bind->getType()->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 7198 CXXDestructorDecl *Destructor = LookupDestructor(RD); 7199 Temp->setDestructor(Destructor); 7200 7201 MarkFunctionReferenced(Bind->getExprLoc(), Destructor); 7202 CheckDestructorAccess(Bind->getExprLoc(), Destructor, 7203 PDiag(diag::err_access_dtor_temp) 7204 << Bind->getType()); 7205 if (DiagnoseUseOfDecl(Destructor, Bind->getExprLoc())) 7206 return ExprError(); 7207 7208 // We need a cleanup, but we don't need to remember the temporary. 7209 Cleanup.setExprNeedsCleanups(true); 7210 } 7211 7212 // Possibly strip off the top CXXBindTemporaryExpr. 7213 return E; 7214} 7215 7216/// Note a set of 'operator->' functions that were used for a member access. 7217static void noteOperatorArrows(Sema &S, 7218 ArrayRef<FunctionDecl *> OperatorArrows) { 7219 unsigned SkipStart = OperatorArrows.size(), SkipCount = 0; 7220 // FIXME: Make this configurable? 7221 unsigned Limit = 9; 7222 if (OperatorArrows.size() > Limit) { 7223 // Produce Limit-1 normal notes and one 'skipping' note. 7224 SkipStart = (Limit - 1) / 2 + (Limit - 1) % 2; 7225 SkipCount = OperatorArrows.size() - (Limit - 1); 7226 } 7227 7228 for (unsigned I = 0; I < OperatorArrows.size(); /**/) { 7229 if (I == SkipStart) { 7230 S.Diag(OperatorArrows[I]->getLocation(), 7231 diag::note_operator_arrows_suppressed) 7232 << SkipCount; 7233 I += SkipCount; 7234 } else { 7235 S.Diag(OperatorArrows[I]->getLocation(), diag::note_operator_arrow_here) 7236 << OperatorArrows[I]->getCallResultType(); 7237 ++I; 7238 } 7239 } 7240} 7241 7242ExprResult Sema::ActOnStartCXXMemberReference(Scope *S, Expr *Base, 7243 SourceLocation OpLoc, 7244 tok::TokenKind OpKind, 7245 ParsedType &ObjectType, 7246 bool &MayBePseudoDestructor) { 7247 // Since this might be a postfix expression, get rid of ParenListExprs. 7248 ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); 7249 if (Result.isInvalid()) return ExprError(); 7250 Base = Result.get(); 7251 7252 Result = CheckPlaceholderExpr(Base); 7253 if (Result.isInvalid()) return ExprError(); 7254 Base = Result.get(); 7255 7256 QualType BaseType = Base->getType(); 7257 MayBePseudoDestructor = false; 7258 if (BaseType->isDependentType()) { 7259 // If we have a pointer to a dependent type and are using the -> operator, 7260 // the object type is the type that the pointer points to. We might still 7261 // have enough information about that type to do something useful. 7262 if (OpKind == tok::arrow) 7263 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) 7264 BaseType = Ptr->getPointeeType(); 7265 7266 ObjectType = ParsedType::make(BaseType); 7267 MayBePseudoDestructor = true; 7268 return Base; 7269 } 7270 7271 // C++ [over.match.oper]p8: 7272 // [...] When operator->returns, the operator-> is applied to the value 7273 // returned, with the original second operand. 7274 if (OpKind == tok::arrow) { 7275 QualType StartingType = BaseType; 7276 bool NoArrowOperatorFound = false; 7277 bool FirstIteration = true; 7278 FunctionDecl *CurFD = dyn_cast<FunctionDecl>(CurContext); 7279 // The set of types we've considered so far. 7280 llvm::SmallPtrSet<CanQualType,8> CTypes; 7281 SmallVector<FunctionDecl*, 8> OperatorArrows; 7282 CTypes.insert(Context.getCanonicalType(BaseType)); 7283 7284 while (BaseType->isRecordType()) { 7285 if (OperatorArrows.size() >= getLangOpts().ArrowDepth) { 7286 Diag(OpLoc, diag::err_operator_arrow_depth_exceeded) 7287 << StartingType << getLangOpts().ArrowDepth << Base->getSourceRange(); 7288 noteOperatorArrows(*this, OperatorArrows); 7289 Diag(OpLoc, diag::note_operator_arrow_depth) 7290 << getLangOpts().ArrowDepth; 7291 return ExprError(); 7292 } 7293 7294 Result = BuildOverloadedArrowExpr( 7295 S, Base, OpLoc, 7296 // When in a template specialization and on the first loop iteration, 7297 // potentially give the default diagnostic (with the fixit in a 7298 // separate note) instead of having the error reported back to here 7299 // and giving a diagnostic with a fixit attached to the error itself. 7300 (FirstIteration && CurFD && CurFD->isFunctionTemplateSpecialization()) 7301 ? nullptr 7302 : &NoArrowOperatorFound); 7303 if (Result.isInvalid()) { 7304 if (NoArrowOperatorFound) { 7305 if (FirstIteration) { 7306 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 7307 << BaseType << 1 << Base->getSourceRange() 7308 << FixItHint::CreateReplacement(OpLoc, "."); 7309 OpKind = tok::period; 7310 break; 7311 } 7312 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7313 << BaseType << Base->getSourceRange(); 7314 CallExpr *CE = dyn_cast<CallExpr>(Base); 7315 if (Decl *CD = (CE ? CE->getCalleeDecl() : nullptr)) { 7316 Diag(CD->getBeginLoc(), 7317 diag::note_member_reference_arrow_from_operator_arrow); 7318 } 7319 } 7320 return ExprError(); 7321 } 7322 Base = Result.get(); 7323 if (CXXOperatorCallExpr *OpCall = dyn_cast<CXXOperatorCallExpr>(Base)) 7324 OperatorArrows.push_back(OpCall->getDirectCallee()); 7325 BaseType = Base->getType(); 7326 CanQualType CBaseType = Context.getCanonicalType(BaseType); 7327 if (!CTypes.insert(CBaseType).second) { 7328 Diag(OpLoc, diag::err_operator_arrow_circular) << StartingType; 7329 noteOperatorArrows(*this, OperatorArrows); 7330 return ExprError(); 7331 } 7332 FirstIteration = false; 7333 } 7334 7335 if (OpKind == tok::arrow) { 7336 if (BaseType->isPointerType()) 7337 BaseType = BaseType->getPointeeType(); 7338 else if (auto *AT = Context.getAsArrayType(BaseType)) 7339 BaseType = AT->getElementType(); 7340 } 7341 } 7342 7343 // Objective-C properties allow "." access on Objective-C pointer types, 7344 // so adjust the base type to the object type itself. 7345 if (BaseType->isObjCObjectPointerType()) 7346 BaseType = BaseType->getPointeeType(); 7347 7348 // C++ [basic.lookup.classref]p2: 7349 // [...] If the type of the object expression is of pointer to scalar 7350 // type, the unqualified-id is looked up in the context of the complete 7351 // postfix-expression. 7352 // 7353 // This also indicates that we could be parsing a pseudo-destructor-name. 7354 // Note that Objective-C class and object types can be pseudo-destructor 7355 // expressions or normal member (ivar or property) access expressions, and 7356 // it's legal for the type to be incomplete if this is a pseudo-destructor 7357 // call. We'll do more incomplete-type checks later in the lookup process, 7358 // so just skip this check for ObjC types. 7359 if (!BaseType->isRecordType()) { 7360 ObjectType = ParsedType::make(BaseType); 7361 MayBePseudoDestructor = true; 7362 return Base; 7363 } 7364 7365 // The object type must be complete (or dependent), or 7366 // C++11 [expr.prim.general]p3: 7367 // Unlike the object expression in other contexts, *this is not required to 7368 // be of complete type for purposes of class member access (5.2.5) outside 7369 // the member function body. 7370 if (!BaseType->isDependentType() && 7371 !isThisOutsideMemberFunctionBody(BaseType) && 7372 RequireCompleteType(OpLoc, BaseType, diag::err_incomplete_member_access)) 7373 return ExprError(); 7374 7375 // C++ [basic.lookup.classref]p2: 7376 // If the id-expression in a class member access (5.2.5) is an 7377 // unqualified-id, and the type of the object expression is of a class 7378 // type C (or of pointer to a class type C), the unqualified-id is looked 7379 // up in the scope of class C. [...] 7380 ObjectType = ParsedType::make(BaseType); 7381 return Base; 7382} 7383 7384static bool CheckArrow(Sema &S, QualType &ObjectType, Expr *&Base, 7385 tok::TokenKind &OpKind, SourceLocation OpLoc) { 7386 if (Base->hasPlaceholderType()) { 7387 ExprResult result = S.CheckPlaceholderExpr(Base); 7388 if (result.isInvalid()) return true; 7389 Base = result.get(); 7390 } 7391 ObjectType = Base->getType(); 7392 7393 // C++ [expr.pseudo]p2: 7394 // The left-hand side of the dot operator shall be of scalar type. The 7395 // left-hand side of the arrow operator shall be of pointer to scalar type. 7396 // This scalar type is the object type. 7397 // Note that this is rather different from the normal handling for the 7398 // arrow operator. 7399 if (OpKind == tok::arrow) { 7400 // The operator requires a prvalue, so perform lvalue conversions. 7401 // Only do this if we might plausibly end with a pointer, as otherwise 7402 // this was likely to be intended to be a '.'. 7403 if (ObjectType->isPointerType() || ObjectType->isArrayType() || 7404 ObjectType->isFunctionType()) { 7405 ExprResult BaseResult = S.DefaultFunctionArrayLvalueConversion(Base); 7406 if (BaseResult.isInvalid()) 7407 return true; 7408 Base = BaseResult.get(); 7409 ObjectType = Base->getType(); 7410 } 7411 7412 if (const PointerType *Ptr = ObjectType->getAs<PointerType>()) { 7413 ObjectType = Ptr->getPointeeType(); 7414 } else if (!Base->isTypeDependent()) { 7415 // The user wrote "p->" when they probably meant "p."; fix it. 7416 S.Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 7417 << ObjectType << true 7418 << FixItHint::CreateReplacement(OpLoc, "."); 7419 if (S.isSFINAEContext()) 7420 return true; 7421 7422 OpKind = tok::period; 7423 } 7424 } 7425 7426 return false; 7427} 7428 7429/// Check if it's ok to try and recover dot pseudo destructor calls on 7430/// pointer objects. 7431static bool 7432canRecoverDotPseudoDestructorCallsOnPointerObjects(Sema &SemaRef, 7433 QualType DestructedType) { 7434 // If this is a record type, check if its destructor is callable. 7435 if (auto *RD = DestructedType->getAsCXXRecordDecl()) { 7436 if (RD->hasDefinition()) 7437 if (CXXDestructorDecl *D = SemaRef.LookupDestructor(RD)) 7438 return SemaRef.CanUseDecl(D, /*TreatUnavailableAsInvalid=*/false); 7439 return false; 7440 } 7441 7442 // Otherwise, check if it's a type for which it's valid to use a pseudo-dtor. 7443 return DestructedType->isDependentType() || DestructedType->isScalarType() || 7444 DestructedType->isVectorType(); 7445} 7446 7447ExprResult Sema::BuildPseudoDestructorExpr(Expr *Base, 7448 SourceLocation OpLoc, 7449 tok::TokenKind OpKind, 7450 const CXXScopeSpec &SS, 7451 TypeSourceInfo *ScopeTypeInfo, 7452 SourceLocation CCLoc, 7453 SourceLocation TildeLoc, 7454 PseudoDestructorTypeStorage Destructed) { 7455 TypeSourceInfo *DestructedTypeInfo = Destructed.getTypeSourceInfo(); 7456 7457 QualType ObjectType; 7458 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 7459 return ExprError(); 7460 7461 if (!ObjectType->isDependentType() && !ObjectType->isScalarType() && 7462 !ObjectType->isVectorType()) { 7463 if (getLangOpts().MSVCCompat && ObjectType->isVoidType()) 7464 Diag(OpLoc, diag::ext_pseudo_dtor_on_void) << Base->getSourceRange(); 7465 else { 7466 Diag(OpLoc, diag::err_pseudo_dtor_base_not_scalar) 7467 << ObjectType << Base->getSourceRange(); 7468 return ExprError(); 7469 } 7470 } 7471 7472 // C++ [expr.pseudo]p2: 7473 // [...] The cv-unqualified versions of the object type and of the type 7474 // designated by the pseudo-destructor-name shall be the same type. 7475 if (DestructedTypeInfo) { 7476 QualType DestructedType = DestructedTypeInfo->getType(); 7477 SourceLocation DestructedTypeStart 7478 = DestructedTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(); 7479 if (!DestructedType->isDependentType() && !ObjectType->isDependentType()) { 7480 if (!Context.hasSameUnqualifiedType(DestructedType, ObjectType)) { 7481 // Detect dot pseudo destructor calls on pointer objects, e.g.: 7482 // Foo *foo; 7483 // foo.~Foo(); 7484 if (OpKind == tok::period && ObjectType->isPointerType() && 7485 Context.hasSameUnqualifiedType(DestructedType, 7486 ObjectType->getPointeeType())) { 7487 auto Diagnostic = 7488 Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) 7489 << ObjectType << /*IsArrow=*/0 << Base->getSourceRange(); 7490 7491 // Issue a fixit only when the destructor is valid. 7492 if (canRecoverDotPseudoDestructorCallsOnPointerObjects( 7493 *this, DestructedType)) 7494 Diagnostic << FixItHint::CreateReplacement(OpLoc, "->"); 7495 7496 // Recover by setting the object type to the destructed type and the 7497 // operator to '->'. 7498 ObjectType = DestructedType; 7499 OpKind = tok::arrow; 7500 } else { 7501 Diag(DestructedTypeStart, diag::err_pseudo_dtor_type_mismatch) 7502 << ObjectType << DestructedType << Base->getSourceRange() 7503 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 7504 7505 // Recover by setting the destructed type to the object type. 7506 DestructedType = ObjectType; 7507 DestructedTypeInfo = 7508 Context.getTrivialTypeSourceInfo(ObjectType, DestructedTypeStart); 7509 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 7510 } 7511 } else if (DestructedType.getObjCLifetime() != 7512 ObjectType.getObjCLifetime()) { 7513 7514 if (DestructedType.getObjCLifetime() == Qualifiers::OCL_None) { 7515 // Okay: just pretend that the user provided the correctly-qualified 7516 // type. 7517 } else { 7518 Diag(DestructedTypeStart, diag::err_arc_pseudo_dtor_inconstant_quals) 7519 << ObjectType << DestructedType << Base->getSourceRange() 7520 << DestructedTypeInfo->getTypeLoc().getLocalSourceRange(); 7521 } 7522 7523 // Recover by setting the destructed type to the object type. 7524 DestructedType = ObjectType; 7525 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(ObjectType, 7526 DestructedTypeStart); 7527 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 7528 } 7529 } 7530 } 7531 7532 // C++ [expr.pseudo]p2: 7533 // [...] Furthermore, the two type-names in a pseudo-destructor-name of the 7534 // form 7535 // 7536 // ::[opt] nested-name-specifier[opt] type-name :: ~ type-name 7537 // 7538 // shall designate the same scalar type. 7539 if (ScopeTypeInfo) { 7540 QualType ScopeType = ScopeTypeInfo->getType(); 7541 if (!ScopeType->isDependentType() && !ObjectType->isDependentType() && 7542 !Context.hasSameUnqualifiedType(ScopeType, ObjectType)) { 7543 7544 Diag(ScopeTypeInfo->getTypeLoc().getLocalSourceRange().getBegin(), 7545 diag::err_pseudo_dtor_type_mismatch) 7546 << ObjectType << ScopeType << Base->getSourceRange() 7547 << ScopeTypeInfo->getTypeLoc().getLocalSourceRange(); 7548 7549 ScopeType = QualType(); 7550 ScopeTypeInfo = nullptr; 7551 } 7552 } 7553 7554 Expr *Result 7555 = new (Context) CXXPseudoDestructorExpr(Context, Base, 7556 OpKind == tok::arrow, OpLoc, 7557 SS.getWithLocInContext(Context), 7558 ScopeTypeInfo, 7559 CCLoc, 7560 TildeLoc, 7561 Destructed); 7562 7563 return Result; 7564} 7565 7566ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 7567 SourceLocation OpLoc, 7568 tok::TokenKind OpKind, 7569 CXXScopeSpec &SS, 7570 UnqualifiedId &FirstTypeName, 7571 SourceLocation CCLoc, 7572 SourceLocation TildeLoc, 7573 UnqualifiedId &SecondTypeName) { 7574 assert((FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||((void)0) 7575 FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&((void)0) 7576 "Invalid first type name in pseudo-destructor")((void)0); 7577 assert((SecondTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId ||((void)0) 7578 SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) &&((void)0) 7579 "Invalid second type name in pseudo-destructor")((void)0); 7580 7581 QualType ObjectType; 7582 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 7583 return ExprError(); 7584 7585 // Compute the object type that we should use for name lookup purposes. Only 7586 // record types and dependent types matter. 7587 ParsedType ObjectTypePtrForLookup; 7588 if (!SS.isSet()) { 7589 if (ObjectType->isRecordType()) 7590 ObjectTypePtrForLookup = ParsedType::make(ObjectType); 7591 else if (ObjectType->isDependentType()) 7592 ObjectTypePtrForLookup = ParsedType::make(Context.DependentTy); 7593 } 7594 7595 // Convert the name of the type being destructed (following the ~) into a 7596 // type (with source-location information). 7597 QualType DestructedType; 7598 TypeSourceInfo *DestructedTypeInfo = nullptr; 7599 PseudoDestructorTypeStorage Destructed; 7600 if (SecondTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) { 7601 ParsedType T = getTypeName(*SecondTypeName.Identifier, 7602 SecondTypeName.StartLocation, 7603 S, &SS, true, false, ObjectTypePtrForLookup, 7604 /*IsCtorOrDtorName*/true); 7605 if (!T && 7606 ((SS.isSet() && !computeDeclContext(SS, false)) || 7607 (!SS.isSet() && ObjectType->isDependentType()))) { 7608 // The name of the type being destroyed is a dependent name, and we 7609 // couldn't find anything useful in scope. Just store the identifier and 7610 // it's location, and we'll perform (qualified) name lookup again at 7611 // template instantiation time. 7612 Destructed = PseudoDestructorTypeStorage(SecondTypeName.Identifier, 7613 SecondTypeName.StartLocation); 7614 } else if (!T) { 7615 Diag(SecondTypeName.StartLocation, 7616 diag::err_pseudo_dtor_destructor_non_type) 7617 << SecondTypeName.Identifier << ObjectType; 7618 if (isSFINAEContext()) 7619 return ExprError(); 7620 7621 // Recover by assuming we had the right type all along. 7622 DestructedType = ObjectType; 7623 } else 7624 DestructedType = GetTypeFromParser(T, &DestructedTypeInfo); 7625 } else { 7626 // Resolve the template-id to a type. 7627 TemplateIdAnnotation *TemplateId = SecondTypeName.TemplateId; 7628 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 7629 TemplateId->NumArgs); 7630 TypeResult T = ActOnTemplateIdType(S, 7631 SS, 7632 TemplateId->TemplateKWLoc, 7633 TemplateId->Template, 7634 TemplateId->Name, 7635 TemplateId->TemplateNameLoc, 7636 TemplateId->LAngleLoc, 7637 TemplateArgsPtr, 7638 TemplateId->RAngleLoc, 7639 /*IsCtorOrDtorName*/true); 7640 if (T.isInvalid() || !T.get()) { 7641 // Recover by assuming we had the right type all along. 7642 DestructedType = ObjectType; 7643 } else 7644 DestructedType = GetTypeFromParser(T.get(), &DestructedTypeInfo); 7645 } 7646 7647 // If we've performed some kind of recovery, (re-)build the type source 7648 // information. 7649 if (!DestructedType.isNull()) { 7650 if (!DestructedTypeInfo) 7651 DestructedTypeInfo = Context.getTrivialTypeSourceInfo(DestructedType, 7652 SecondTypeName.StartLocation); 7653 Destructed = PseudoDestructorTypeStorage(DestructedTypeInfo); 7654 } 7655 7656 // Convert the name of the scope type (the type prior to '::') into a type. 7657 TypeSourceInfo *ScopeTypeInfo = nullptr; 7658 QualType ScopeType; 7659 if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_TemplateId || 7660 FirstTypeName.Identifier) { 7661 if (FirstTypeName.getKind() == UnqualifiedIdKind::IK_Identifier) { 7662 ParsedType T = getTypeName(*FirstTypeName.Identifier, 7663 FirstTypeName.StartLocation, 7664 S, &SS, true, false, ObjectTypePtrForLookup, 7665 /*IsCtorOrDtorName*/true); 7666 if (!T) { 7667 Diag(FirstTypeName.StartLocation, 7668 diag::err_pseudo_dtor_destructor_non_type) 7669 << FirstTypeName.Identifier << ObjectType; 7670 7671 if (isSFINAEContext()) 7672 return ExprError(); 7673 7674 // Just drop this type. It's unnecessary anyway. 7675 ScopeType = QualType(); 7676 } else 7677 ScopeType = GetTypeFromParser(T, &ScopeTypeInfo); 7678 } else { 7679 // Resolve the template-id to a type. 7680 TemplateIdAnnotation *TemplateId = FirstTypeName.TemplateId; 7681 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(), 7682 TemplateId->NumArgs); 7683 TypeResult T = ActOnTemplateIdType(S, 7684 SS, 7685 TemplateId->TemplateKWLoc, 7686 TemplateId->Template, 7687 TemplateId->Name, 7688 TemplateId->TemplateNameLoc, 7689 TemplateId->LAngleLoc, 7690 TemplateArgsPtr, 7691 TemplateId->RAngleLoc, 7692 /*IsCtorOrDtorName*/true); 7693 if (T.isInvalid() || !T.get()) { 7694 // Recover by dropping this type. 7695 ScopeType = QualType(); 7696 } else 7697 ScopeType = GetTypeFromParser(T.get(), &ScopeTypeInfo); 7698 } 7699 } 7700 7701 if (!ScopeType.isNull() && !ScopeTypeInfo) 7702 ScopeTypeInfo = Context.getTrivialTypeSourceInfo(ScopeType, 7703 FirstTypeName.StartLocation); 7704 7705 7706 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, SS, 7707 ScopeTypeInfo, CCLoc, TildeLoc, 7708 Destructed); 7709} 7710 7711ExprResult Sema::ActOnPseudoDestructorExpr(Scope *S, Expr *Base, 7712 SourceLocation OpLoc, 7713 tok::TokenKind OpKind, 7714 SourceLocation TildeLoc, 7715 const DeclSpec& DS) { 7716 QualType ObjectType; 7717 if (CheckArrow(*this, ObjectType, Base, OpKind, OpLoc)) 7718 return ExprError(); 7719 7720 if (DS.getTypeSpecType() == DeclSpec::TST_decltype_auto) { 7721 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid); 7722 return true; 7723 } 7724 7725 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc(), 7726 false); 7727 7728 TypeLocBuilder TLB; 7729 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); 7730 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); 7731 TypeSourceInfo *DestructedTypeInfo = TLB.getTypeSourceInfo(Context, T); 7732 PseudoDestructorTypeStorage Destructed(DestructedTypeInfo); 7733 7734 return BuildPseudoDestructorExpr(Base, OpLoc, OpKind, CXXScopeSpec(), 7735 nullptr, SourceLocation(), TildeLoc, 7736 Destructed); 7737} 7738 7739ExprResult Sema::BuildCXXMemberCallExpr(Expr *E, NamedDecl *FoundDecl, 7740 CXXConversionDecl *Method, 7741 bool HadMultipleCandidates) { 7742 // Convert the expression to match the conversion function's implicit object 7743 // parameter. 7744 ExprResult Exp = PerformObjectArgumentInitialization(E, /*Qualifier=*/nullptr, 7745 FoundDecl, Method); 7746 if (Exp.isInvalid()) 7747 return true; 7748 7749 if (Method->getParent()->isLambda() && 7750 Method->getConversionType()->isBlockPointerType()) { 7751 // This is a lambda conversion to block pointer; check if the argument 7752 // was a LambdaExpr. 7753 Expr *SubE = E; 7754 CastExpr *CE = dyn_cast<CastExpr>(SubE); 7755 if (CE && CE->getCastKind() == CK_NoOp) 7756 SubE = CE->getSubExpr(); 7757 SubE = SubE->IgnoreParens(); 7758 if (CXXBindTemporaryExpr *BE = dyn_cast<CXXBindTemporaryExpr>(SubE)) 7759 SubE = BE->getSubExpr(); 7760 if (isa<LambdaExpr>(SubE)) { 7761 // For the conversion to block pointer on a lambda expression, we 7762 // construct a special BlockLiteral instead; this doesn't really make 7763 // a difference in ARC, but outside of ARC the resulting block literal 7764 // follows the normal lifetime rules for block literals instead of being 7765 // autoreleased. 7766 PushExpressionEvaluationContext( 7767 ExpressionEvaluationContext::PotentiallyEvaluated); 7768 ExprResult BlockExp = BuildBlockForLambdaConversion( 7769 Exp.get()->getExprLoc(), Exp.get()->getExprLoc(), Method, Exp.get()); 7770 PopExpressionEvaluationContext(); 7771 7772 // FIXME: This note should be produced by a CodeSynthesisContext. 7773 if (BlockExp.isInvalid()) 7774 Diag(Exp.get()->getExprLoc(), diag::note_lambda_to_block_conv); 7775 return BlockExp; 7776 } 7777 } 7778 7779 MemberExpr *ME = 7780 BuildMemberExpr(Exp.get(), /*IsArrow=*/false, SourceLocation(), 7781 NestedNameSpecifierLoc(), SourceLocation(), Method, 7782 DeclAccessPair::make(FoundDecl, FoundDecl->getAccess()), 7783 HadMultipleCandidates, DeclarationNameInfo(), 7784 Context.BoundMemberTy, VK_PRValue, OK_Ordinary); 7785 7786 QualType ResultType = Method->getReturnType(); 7787 ExprValueKind VK = Expr::getValueKindForType(ResultType); 7788 ResultType = ResultType.getNonLValueExprType(Context); 7789 7790 CXXMemberCallExpr *CE = CXXMemberCallExpr::Create( 7791 Context, ME, /*Args=*/{}, ResultType, VK, Exp.get()->getEndLoc(), 7792 CurFPFeatureOverrides()); 7793 7794 if (CheckFunctionCall(Method, CE, 7795 Method->getType()->castAs<FunctionProtoType>())) 7796 return ExprError(); 7797 7798 return CheckForImmediateInvocation(CE, CE->getMethodDecl()); 7799} 7800 7801ExprResult Sema::BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand, 7802 SourceLocation RParen) { 7803 // If the operand is an unresolved lookup expression, the expression is ill- 7804 // formed per [over.over]p1, because overloaded function names cannot be used 7805 // without arguments except in explicit contexts. 7806 ExprResult R = CheckPlaceholderExpr(Operand); 7807 if (R.isInvalid()) 7808 return R; 7809 7810 R = CheckUnevaluatedOperand(R.get()); 7811 if (R.isInvalid()) 7812 return ExprError(); 7813 7814 Operand = R.get(); 7815 7816 if (!inTemplateInstantiation() && !Operand->isInstantiationDependent() && 7817 Operand->HasSideEffects(Context, false)) { 7818 // The expression operand for noexcept is in an unevaluated expression 7819 // context, so side effects could result in unintended consequences. 7820 Diag(Operand->getExprLoc(), diag::warn_side_effects_unevaluated_context); 7821 } 7822 7823 CanThrowResult CanThrow = canThrow(Operand); 7824 return new (Context) 7825 CXXNoexceptExpr(Context.BoolTy, Operand, CanThrow, KeyLoc, RParen); 7826} 7827 7828ExprResult Sema::ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation, 7829 Expr *Operand, SourceLocation RParen) { 7830 return BuildCXXNoexceptExpr(KeyLoc, Operand, RParen); 7831} 7832 7833static void MaybeDecrementCount( 7834 Expr *E, llvm::DenseMap<const VarDecl *, int> &RefsMinusAssignments) { 7835 DeclRefExpr *LHS = nullptr; 7836 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 7837 if (BO->getLHS()->getType()->isDependentType() || 7838 BO->getRHS()->getType()->isDependentType()) { 7839 if (BO->getOpcode() != BO_Assign) 7840 return; 7841 } else if (!BO->isAssignmentOp()) 7842 return; 7843 LHS = dyn_cast<DeclRefExpr>(BO->getLHS()); 7844 } else if (CXXOperatorCallExpr *COCE = dyn_cast<CXXOperatorCallExpr>(E)) { 7845 if (COCE->getOperator() != OO_Equal) 7846 return; 7847 LHS = dyn_cast<DeclRefExpr>(COCE->getArg(0)); 7848 } 7849 if (!LHS) 7850 return; 7851 VarDecl *VD = dyn_cast<VarDecl>(LHS->getDecl()); 7852 if (!VD) 7853 return; 7854 auto iter = RefsMinusAssignments.find(VD); 7855 if (iter == RefsMinusAssignments.end()) 7856 return; 7857 iter->getSecond()--; 7858} 7859 7860/// Perform the conversions required for an expression used in a 7861/// context that ignores the result. 7862ExprResult Sema::IgnoredValueConversions(Expr *E) { 7863 MaybeDecrementCount(E, RefsMinusAssignments); 7864 7865 if (E->hasPlaceholderType()) { 7866 ExprResult result = CheckPlaceholderExpr(E); 7867 if (result.isInvalid()) return E; 7868 E = result.get(); 7869 } 7870 7871 // C99 6.3.2.1: 7872 // [Except in specific positions,] an lvalue that does not have 7873 // array type is converted to the value stored in the 7874 // designated object (and is no longer an lvalue). 7875 if (E->isPRValue()) { 7876 // In C, function designators (i.e. expressions of function type) 7877 // are r-values, but we still want to do function-to-pointer decay 7878 // on them. This is both technically correct and convenient for 7879 // some clients. 7880 if (!getLangOpts().CPlusPlus && E->getType()->isFunctionType()) 7881 return DefaultFunctionArrayConversion(E); 7882 7883 return E; 7884 } 7885 7886 if (getLangOpts().CPlusPlus) { 7887 // The C++11 standard defines the notion of a discarded-value expression; 7888 // normally, we don't need to do anything to handle it, but if it is a 7889 // volatile lvalue with a special form, we perform an lvalue-to-rvalue 7890 // conversion. 7891 if (getLangOpts().CPlusPlus11 && E->isReadIfDiscardedInCPlusPlus11()) { 7892 ExprResult Res = DefaultLvalueConversion(E); 7893 if (Res.isInvalid()) 7894 return E; 7895 E = Res.get(); 7896 } else { 7897 // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if 7898 // it occurs as a discarded-value expression. 7899 CheckUnusedVolatileAssignment(E); 7900 } 7901 7902 // C++1z: 7903 // If the expression is a prvalue after this optional conversion, the 7904 // temporary materialization conversion is applied. 7905 // 7906 // We skip this step: IR generation is able to synthesize the storage for 7907 // itself in the aggregate case, and adding the extra node to the AST is 7908 // just clutter. 7909 // FIXME: We don't emit lifetime markers for the temporaries due to this. 7910 // FIXME: Do any other AST consumers care about this? 7911 return E; 7912 } 7913 7914 // GCC seems to also exclude expressions of incomplete enum type. 7915 if (const EnumType *T = E->getType()->getAs<EnumType>()) { 7916 if (!T->getDecl()->isComplete()) { 7917 // FIXME: stupid workaround for a codegen bug! 7918 E = ImpCastExprToType(E, Context.VoidTy, CK_ToVoid).get(); 7919 return E; 7920 } 7921 } 7922 7923 ExprResult Res = DefaultFunctionArrayLvalueConversion(E); 7924 if (Res.isInvalid()) 7925 return E; 7926 E = Res.get(); 7927 7928 if (!E->getType()->isVoidType()) 7929 RequireCompleteType(E->getExprLoc(), E->getType(), 7930 diag::err_incomplete_type); 7931 return E; 7932} 7933 7934ExprResult Sema::CheckUnevaluatedOperand(Expr *E) { 7935 // Per C++2a [expr.ass]p5, a volatile assignment is not deprecated if 7936 // it occurs as an unevaluated operand. 7937 CheckUnusedVolatileAssignment(E); 7938 7939 return E; 7940} 7941 7942// If we can unambiguously determine whether Var can never be used 7943// in a constant expression, return true. 7944// - if the variable and its initializer are non-dependent, then 7945// we can unambiguously check if the variable is a constant expression. 7946// - if the initializer is not value dependent - we can determine whether 7947// it can be used to initialize a constant expression. If Init can not 7948// be used to initialize a constant expression we conclude that Var can 7949// never be a constant expression. 7950// - FXIME: if the initializer is dependent, we can still do some analysis and 7951// identify certain cases unambiguously as non-const by using a Visitor: 7952// - such as those that involve odr-use of a ParmVarDecl, involve a new 7953// delete, lambda-expr, dynamic-cast, reinterpret-cast etc... 7954static inline bool VariableCanNeverBeAConstantExpression(VarDecl *Var, 7955 ASTContext &Context) { 7956 if (isa<ParmVarDecl>(Var)) return true; 7957 const VarDecl *DefVD = nullptr; 7958 7959 // If there is no initializer - this can not be a constant expression. 7960 if (!Var->getAnyInitializer(DefVD)) return true; 7961 assert(DefVD)((void)0); 7962 if (DefVD->isWeak()) return false; 7963 EvaluatedStmt *Eval = DefVD->ensureEvaluatedStmt(); 7964 7965 Expr *Init = cast<Expr>(Eval->Value); 7966 7967 if (Var->getType()->isDependentType() || Init->isValueDependent()) { 7968 // FIXME: Teach the constant evaluator to deal with the non-dependent parts 7969 // of value-dependent expressions, and use it here to determine whether the 7970 // initializer is a potential constant expression. 7971 return false; 7972 } 7973 7974 return !Var->isUsableInConstantExpressions(Context); 7975} 7976 7977/// Check if the current lambda has any potential captures 7978/// that must be captured by any of its enclosing lambdas that are ready to 7979/// capture. If there is a lambda that can capture a nested 7980/// potential-capture, go ahead and do so. Also, check to see if any 7981/// variables are uncaptureable or do not involve an odr-use so do not 7982/// need to be captured. 7983 7984static void CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures( 7985 Expr *const FE, LambdaScopeInfo *const CurrentLSI, Sema &S) { 7986 7987 assert(!S.isUnevaluatedContext())((void)0); 7988 assert(S.CurContext->isDependentContext())((void)0); 7989#ifndef NDEBUG1 7990 DeclContext *DC = S.CurContext; 7991 while (DC && isa<CapturedDecl>(DC)) 7992 DC = DC->getParent(); 7993 assert(((void)0) 7994 CurrentLSI->CallOperator == DC &&((void)0) 7995 "The current call operator must be synchronized with Sema's CurContext")((void)0); 7996#endif // NDEBUG 7997 7998 const bool IsFullExprInstantiationDependent = FE->isInstantiationDependent(); 7999 8000 // All the potentially captureable variables in the current nested 8001 // lambda (within a generic outer lambda), must be captured by an 8002 // outer lambda that is enclosed within a non-dependent context. 8003 CurrentLSI->visitPotentialCaptures([&] (VarDecl *Var, Expr *VarExpr) { 8004 // If the variable is clearly identified as non-odr-used and the full 8005 // expression is not instantiation dependent, only then do we not 8006 // need to check enclosing lambda's for speculative captures. 8007 // For e.g.: 8008 // Even though 'x' is not odr-used, it should be captured. 8009 // int test() { 8010 // const int x = 10; 8011 // auto L = [=](auto a) { 8012 // (void) +x + a; 8013 // }; 8014 // } 8015 if (CurrentLSI->isVariableExprMarkedAsNonODRUsed(VarExpr) && 8016 !IsFullExprInstantiationDependent) 8017 return; 8018 8019 // If we have a capture-capable lambda for the variable, go ahead and 8020 // capture the variable in that lambda (and all its enclosing lambdas). 8021 if (const Optional<unsigned> Index = 8022 getStackIndexOfNearestEnclosingCaptureCapableLambda( 8023 S.FunctionScopes, Var, S)) 8024 S.MarkCaptureUsedInEnclosingContext(Var, VarExpr->getExprLoc(), 8025 Index.getValue()); 8026 const bool IsVarNeverAConstantExpression = 8027 VariableCanNeverBeAConstantExpression(Var, S.Context); 8028 if (!IsFullExprInstantiationDependent || IsVarNeverAConstantExpression) { 8029 // This full expression is not instantiation dependent or the variable 8030 // can not be used in a constant expression - which means 8031 // this variable must be odr-used here, so diagnose a 8032 // capture violation early, if the variable is un-captureable. 8033 // This is purely for diagnosing errors early. Otherwise, this 8034 // error would get diagnosed when the lambda becomes capture ready. 8035 QualType CaptureType, DeclRefType; 8036 SourceLocation ExprLoc = VarExpr->getExprLoc(); 8037 if (S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 8038 /*EllipsisLoc*/ SourceLocation(), 8039 /*BuildAndDiagnose*/false, CaptureType, 8040 DeclRefType, nullptr)) { 8041 // We will never be able to capture this variable, and we need 8042 // to be able to in any and all instantiations, so diagnose it. 8043 S.tryCaptureVariable(Var, ExprLoc, S.TryCapture_Implicit, 8044 /*EllipsisLoc*/ SourceLocation(), 8045 /*BuildAndDiagnose*/true, CaptureType, 8046 DeclRefType, nullptr); 8047 } 8048 } 8049 }); 8050 8051 // Check if 'this' needs to be captured. 8052 if (CurrentLSI->hasPotentialThisCapture()) { 8053 // If we have a capture-capable lambda for 'this', go ahead and capture 8054 // 'this' in that lambda (and all its enclosing lambdas). 8055 if (const Optional<unsigned> Index = 8056 getStackIndexOfNearestEnclosingCaptureCapableLambda( 8057 S.FunctionScopes, /*0 is 'this'*/ nullptr, S)) { 8058 const unsigned FunctionScopeIndexOfCapturableLambda = Index.getValue(); 8059 S.CheckCXXThisCapture(CurrentLSI->PotentialThisCaptureLocation, 8060 /*Explicit*/ false, /*BuildAndDiagnose*/ true, 8061 &FunctionScopeIndexOfCapturableLambda); 8062 } 8063 } 8064 8065 // Reset all the potential captures at the end of each full-expression. 8066 CurrentLSI->clearPotentialCaptures(); 8067} 8068 8069static ExprResult attemptRecovery(Sema &SemaRef, 8070 const TypoCorrectionConsumer &Consumer, 8071 const TypoCorrection &TC) { 8072 LookupResult R(SemaRef, Consumer.getLookupResult().getLookupNameInfo(), 8073 Consumer.getLookupResult().getLookupKind()); 8074 const CXXScopeSpec *SS = Consumer.getSS(); 8075 CXXScopeSpec NewSS; 8076 8077 // Use an approprate CXXScopeSpec for building the expr. 8078 if (auto *NNS = TC.getCorrectionSpecifier()) 8079 NewSS.MakeTrivial(SemaRef.Context, NNS, TC.getCorrectionRange()); 8080 else if (SS && !TC.WillReplaceSpecifier()) 8081 NewSS = *SS; 8082 8083 if (auto *ND = TC.getFoundDecl()) { 8084 R.setLookupName(ND->getDeclName()); 8085 R.addDecl(ND); 8086 if (ND->isCXXClassMember()) { 8087 // Figure out the correct naming class to add to the LookupResult. 8088 CXXRecordDecl *Record = nullptr; 8089 if (auto *NNS = TC.getCorrectionSpecifier()) 8090 Record = NNS->getAsType()->getAsCXXRecordDecl(); 8091 if (!Record) 8092 Record = 8093 dyn_cast<CXXRecordDecl>(ND->getDeclContext()->getRedeclContext()); 8094 if (Record) 8095 R.setNamingClass(Record); 8096 8097 // Detect and handle the case where the decl might be an implicit 8098 // member. 8099 bool MightBeImplicitMember; 8100 if (!Consumer.isAddressOfOperand()) 8101 MightBeImplicitMember = true; 8102 else if (!NewSS.isEmpty()) 8103 MightBeImplicitMember = false; 8104 else if (R.isOverloadedResult()) 8105 MightBeImplicitMember = false; 8106 else if (R.isUnresolvableResult()) 8107 MightBeImplicitMember = true; 8108 else 8109 MightBeImplicitMember = isa<FieldDecl>(ND) || 8110 isa<IndirectFieldDecl>(ND) || 8111 isa<MSPropertyDecl>(ND); 8112 8113 if (MightBeImplicitMember) 8114 return SemaRef.BuildPossibleImplicitMemberExpr( 8115 NewSS, /*TemplateKWLoc*/ SourceLocation(), R, 8116 /*TemplateArgs*/ nullptr, /*S*/ nullptr); 8117 } else if (auto *Ivar = dyn_cast<ObjCIvarDecl>(ND)) { 8118 return SemaRef.LookupInObjCMethod(R, Consumer.getScope(), 8119 Ivar->getIdentifier()); 8120 } 8121 } 8122 8123 return SemaRef.BuildDeclarationNameExpr(NewSS, R, /*NeedsADL*/ false, 8124 /*AcceptInvalidDecl*/ true); 8125} 8126 8127namespace { 8128class FindTypoExprs : public RecursiveASTVisitor<FindTypoExprs> { 8129 llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs; 8130 8131public: 8132 explicit FindTypoExprs(llvm::SmallSetVector<TypoExpr *, 2> &TypoExprs) 8133 : TypoExprs(TypoExprs) {} 8134 bool VisitTypoExpr(TypoExpr *TE) { 8135 TypoExprs.insert(TE); 8136 return true; 8137 } 8138}; 8139 8140class TransformTypos : public TreeTransform<TransformTypos> { 8141 typedef TreeTransform<TransformTypos> BaseTransform; 8142 8143 VarDecl *InitDecl; // A decl to avoid as a correction because it is in the 8144 // process of being initialized. 8145 llvm::function_ref<ExprResult(Expr *)> ExprFilter; 8146 llvm::SmallSetVector<TypoExpr *, 2> TypoExprs, AmbiguousTypoExprs; 8147 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2> TransformCache; 8148 llvm::SmallDenseMap<OverloadExpr *, Expr *, 4> OverloadResolution; 8149 8150 /// Emit diagnostics for all of the TypoExprs encountered. 8151 /// 8152 /// If the TypoExprs were successfully corrected, then the diagnostics should 8153 /// suggest the corrections. Otherwise the diagnostics will not suggest 8154 /// anything (having been passed an empty TypoCorrection). 8155 /// 8156 /// If we've failed to correct due to ambiguous corrections, we need to 8157 /// be sure to pass empty corrections and replacements. Otherwise it's 8158 /// possible that the Consumer has a TypoCorrection that failed to ambiguity 8159 /// and we don't want to report those diagnostics. 8160 void EmitAllDiagnostics(bool IsAmbiguous) { 8161 for (TypoExpr *TE : TypoExprs) { 8162 auto &State = SemaRef.getTypoExprState(TE); 8163 if (State.DiagHandler) { 8164 TypoCorrection TC = IsAmbiguous 8165 ? TypoCorrection() : State.Consumer->getCurrentCorrection(); 8166 ExprResult Replacement = IsAmbiguous ? ExprError() : TransformCache[TE]; 8167 8168 // Extract the NamedDecl from the transformed TypoExpr and add it to the 8169 // TypoCorrection, replacing the existing decls. This ensures the right 8170 // NamedDecl is used in diagnostics e.g. in the case where overload 8171 // resolution was used to select one from several possible decls that 8172 // had been stored in the TypoCorrection. 8173 if (auto *ND = getDeclFromExpr( 8174 Replacement.isInvalid() ? nullptr : Replacement.get())) 8175 TC.setCorrectionDecl(ND); 8176 8177 State.DiagHandler(TC); 8178 } 8179 SemaRef.clearDelayedTypo(TE); 8180 } 8181 } 8182 8183 /// Try to advance the typo correction state of the first unfinished TypoExpr. 8184 /// We allow advancement of the correction stream by removing it from the 8185 /// TransformCache which allows `TransformTypoExpr` to advance during the 8186 /// next transformation attempt. 8187 /// 8188 /// Any substitution attempts for the previous TypoExprs (which must have been 8189 /// finished) will need to be retried since it's possible that they will now 8190 /// be invalid given the latest advancement. 8191 /// 8192 /// We need to be sure that we're making progress - it's possible that the 8193 /// tree is so malformed that the transform never makes it to the 8194 /// `TransformTypoExpr`. 8195 /// 8196 /// Returns true if there are any untried correction combinations. 8197 bool CheckAndAdvanceTypoExprCorrectionStreams() { 8198 for (auto TE : TypoExprs) { 8199 auto &State = SemaRef.getTypoExprState(TE); 8200 TransformCache.erase(TE); 8201 if (!State.Consumer->hasMadeAnyCorrectionProgress()) 8202 return false; 8203 if (!State.Consumer->finished()) 8204 return true; 8205 State.Consumer->resetCorrectionStream(); 8206 } 8207 return false; 8208 } 8209 8210 NamedDecl *getDeclFromExpr(Expr *E) { 8211 if (auto *OE = dyn_cast_or_null<OverloadExpr>(E)) 8212 E = OverloadResolution[OE]; 8213 8214 if (!E) 8215 return nullptr; 8216 if (auto *DRE = dyn_cast<DeclRefExpr>(E)) 8217 return DRE->getFoundDecl(); 8218 if (auto *ME = dyn_cast<MemberExpr>(E)) 8219 return ME->getFoundDecl(); 8220 // FIXME: Add any other expr types that could be be seen by the delayed typo 8221 // correction TreeTransform for which the corresponding TypoCorrection could 8222 // contain multiple decls. 8223 return nullptr; 8224 } 8225 8226 ExprResult TryTransform(Expr *E) { 8227 Sema::SFINAETrap Trap(SemaRef); 8228 ExprResult Res = TransformExpr(E); 8229 if (Trap.hasErrorOccurred() || Res.isInvalid()) 8230 return ExprError(); 8231 8232 return ExprFilter(Res.get()); 8233 } 8234 8235 // Since correcting typos may intoduce new TypoExprs, this function 8236 // checks for new TypoExprs and recurses if it finds any. Note that it will 8237 // only succeed if it is able to correct all typos in the given expression. 8238 ExprResult CheckForRecursiveTypos(ExprResult Res, bool &IsAmbiguous) { 8239 if (Res.isInvalid()) { 8240 return Res; 8241 } 8242 // Check to see if any new TypoExprs were created. If so, we need to recurse 8243 // to check their validity. 8244 Expr *FixedExpr = Res.get(); 8245 8246 auto SavedTypoExprs = std::move(TypoExprs); 8247 auto SavedAmbiguousTypoExprs = std::move(AmbiguousTypoExprs); 8248 TypoExprs.clear(); 8249 AmbiguousTypoExprs.clear(); 8250 8251 FindTypoExprs(TypoExprs).TraverseStmt(FixedExpr); 8252 if (!TypoExprs.empty()) { 8253 // Recurse to handle newly created TypoExprs. If we're not able to 8254 // handle them, discard these TypoExprs. 8255 ExprResult RecurResult = 8256 RecursiveTransformLoop(FixedExpr, IsAmbiguous); 8257 if (RecurResult.isInvalid()) { 8258 Res = ExprError(); 8259 // Recursive corrections didn't work, wipe them away and don't add 8260 // them to the TypoExprs set. Remove them from Sema's TypoExpr list 8261 // since we don't want to clear them twice. Note: it's possible the 8262 // TypoExprs were created recursively and thus won't be in our 8263 // Sema's TypoExprs - they were created in our `RecursiveTransformLoop`. 8264 auto &SemaTypoExprs = SemaRef.TypoExprs; 8265 for (auto TE : TypoExprs) { 8266 TransformCache.erase(TE); 8267 SemaRef.clearDelayedTypo(TE); 8268 8269 auto SI = find(SemaTypoExprs, TE); 8270 if (SI != SemaTypoExprs.end()) { 8271 SemaTypoExprs.erase(SI); 8272 } 8273 } 8274 } else { 8275 // TypoExpr is valid: add newly created TypoExprs since we were 8276 // able to correct them. 8277 Res = RecurResult; 8278 SavedTypoExprs.set_union(TypoExprs); 8279 } 8280 } 8281 8282 TypoExprs = std::move(SavedTypoExprs); 8283 AmbiguousTypoExprs = std::move(SavedAmbiguousTypoExprs); 8284 8285 return Res; 8286 } 8287 8288 // Try to transform the given expression, looping through the correction 8289 // candidates with `CheckAndAdvanceTypoExprCorrectionStreams`. 8290 // 8291 // If valid ambiguous typo corrections are seen, `IsAmbiguous` is set to 8292 // true and this method immediately will return an `ExprError`. 8293 ExprResult RecursiveTransformLoop(Expr *E, bool &IsAmbiguous) { 8294 ExprResult Res; 8295 auto SavedTypoExprs = std::move(SemaRef.TypoExprs); 8296 SemaRef.TypoExprs.clear(); 8297 8298 while (true) { 8299 Res = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); 8300 8301 // Recursion encountered an ambiguous correction. This means that our 8302 // correction itself is ambiguous, so stop now. 8303 if (IsAmbiguous) 8304 break; 8305 8306 // If the transform is still valid after checking for any new typos, 8307 // it's good to go. 8308 if (!Res.isInvalid()) 8309 break; 8310 8311 // The transform was invalid, see if we have any TypoExprs with untried 8312 // correction candidates. 8313 if (!CheckAndAdvanceTypoExprCorrectionStreams()) 8314 break; 8315 } 8316 8317 // If we found a valid result, double check to make sure it's not ambiguous. 8318 if (!IsAmbiguous && !Res.isInvalid() && !AmbiguousTypoExprs.empty()) { 8319 auto SavedTransformCache = 8320 llvm::SmallDenseMap<TypoExpr *, ExprResult, 2>(TransformCache); 8321 8322 // Ensure none of the TypoExprs have multiple typo correction candidates 8323 // with the same edit length that pass all the checks and filters. 8324 while (!AmbiguousTypoExprs.empty()) { 8325 auto TE = AmbiguousTypoExprs.back(); 8326 8327 // TryTransform itself can create new Typos, adding them to the TypoExpr map 8328 // and invalidating our TypoExprState, so always fetch it instead of storing. 8329 SemaRef.getTypoExprState(TE).Consumer->saveCurrentPosition(); 8330 8331 TypoCorrection TC = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection(); 8332 TypoCorrection Next; 8333 do { 8334 // Fetch the next correction by erasing the typo from the cache and calling 8335 // `TryTransform` which will iterate through corrections in 8336 // `TransformTypoExpr`. 8337 TransformCache.erase(TE); 8338 ExprResult AmbigRes = CheckForRecursiveTypos(TryTransform(E), IsAmbiguous); 8339 8340 if (!AmbigRes.isInvalid() || IsAmbiguous) { 8341 SemaRef.getTypoExprState(TE).Consumer->resetCorrectionStream(); 8342 SavedTransformCache.erase(TE); 8343 Res = ExprError(); 8344 IsAmbiguous = true; 8345 break; 8346 } 8347 } while ((Next = SemaRef.getTypoExprState(TE).Consumer->peekNextCorrection()) && 8348 Next.getEditDistance(false) == TC.getEditDistance(false)); 8349 8350 if (IsAmbiguous) 8351 break; 8352 8353 AmbiguousTypoExprs.remove(TE); 8354 SemaRef.getTypoExprState(TE).Consumer->restoreSavedPosition(); 8355 TransformCache[TE] = SavedTransformCache[TE]; 8356 } 8357 TransformCache = std::move(SavedTransformCache); 8358 } 8359 8360 // Wipe away any newly created TypoExprs that we don't know about. Since we 8361 // clear any invalid TypoExprs in `CheckForRecursiveTypos`, this is only 8362 // possible if a `TypoExpr` is created during a transformation but then 8363 // fails before we can discover it. 8364 auto &SemaTypoExprs = SemaRef.TypoExprs; 8365 for (auto Iterator = SemaTypoExprs.begin(); Iterator != SemaTypoExprs.end();) { 8366 auto TE = *Iterator; 8367 auto FI = find(TypoExprs, TE); 8368 if (FI != TypoExprs.end()) { 8369 Iterator++; 8370 continue; 8371 } 8372 SemaRef.clearDelayedTypo(TE); 8373 Iterator = SemaTypoExprs.erase(Iterator); 8374 } 8375 SemaRef.TypoExprs = std::move(SavedTypoExprs); 8376 8377 return Res; 8378 } 8379 8380public: 8381 TransformTypos(Sema &SemaRef, VarDecl *InitDecl, llvm::function_ref<ExprResult(Expr *)> Filter) 8382 : BaseTransform(SemaRef), InitDecl(InitDecl), ExprFilter(Filter) {} 8383 8384 ExprResult RebuildCallExpr(Expr *Callee, SourceLocation LParenLoc, 8385 MultiExprArg Args, 8386 SourceLocation RParenLoc, 8387 Expr *ExecConfig = nullptr) { 8388 auto Result = BaseTransform::RebuildCallExpr(Callee, LParenLoc, Args, 8389 RParenLoc, ExecConfig); 8390 if (auto *OE = dyn_cast<OverloadExpr>(Callee)) { 8391 if (Result.isUsable()) { 8392 Expr *ResultCall = Result.get(); 8393 if (auto *BE = dyn_cast<CXXBindTemporaryExpr>(ResultCall)) 8394 ResultCall = BE->getSubExpr(); 8395 if (auto *CE = dyn_cast<CallExpr>(ResultCall)) 8396 OverloadResolution[OE] = CE->getCallee(); 8397 } 8398 } 8399 return Result; 8400 } 8401 8402 ExprResult TransformLambdaExpr(LambdaExpr *E) { return Owned(E); } 8403 8404 ExprResult TransformBlockExpr(BlockExpr *E) { return Owned(E); } 8405 8406 ExprResult Transform(Expr *E) { 8407 bool IsAmbiguous = false; 8408 ExprResult Res = RecursiveTransformLoop(E, IsAmbiguous); 8409 8410 if (!Res.isUsable()) 8411 FindTypoExprs(TypoExprs).TraverseStmt(E); 8412 8413 EmitAllDiagnostics(IsAmbiguous); 8414 8415 return Res; 8416 } 8417 8418 ExprResult TransformTypoExpr(TypoExpr *E) { 8419 // If the TypoExpr hasn't been seen before, record it. Otherwise, return the 8420 // cached transformation result if there is one and the TypoExpr isn't the 8421 // first one that was encountered. 8422 auto &CacheEntry = TransformCache[E]; 8423 if (!TypoExprs.insert(E) && !CacheEntry.isUnset()) { 8424 return CacheEntry; 8425 } 8426 8427 auto &State = SemaRef.getTypoExprState(E); 8428 assert(State.Consumer && "Cannot transform a cleared TypoExpr")((void)0); 8429 8430 // For the first TypoExpr and an uncached TypoExpr, find the next likely 8431 // typo correction and return it. 8432 while (TypoCorrection TC = State.Consumer->getNextCorrection()) { 8433 if (InitDecl && TC.getFoundDecl() == InitDecl) 8434 continue; 8435 // FIXME: If we would typo-correct to an invalid declaration, it's 8436 // probably best to just suppress all errors from this typo correction. 8437 ExprResult NE = State.RecoveryHandler ? 8438 State.RecoveryHandler(SemaRef, E, TC) : 8439 attemptRecovery(SemaRef, *State.Consumer, TC); 8440 if (!NE.isInvalid()) { 8441 // Check whether there may be a second viable correction with the same 8442 // edit distance; if so, remember this TypoExpr may have an ambiguous 8443 // correction so it can be more thoroughly vetted later. 8444 TypoCorrection Next; 8445 if ((Next = State.Consumer->peekNextCorrection()) && 8446 Next.getEditDistance(false) == TC.getEditDistance(false)) { 8447 AmbiguousTypoExprs.insert(E); 8448 } else { 8449 AmbiguousTypoExprs.remove(E); 8450 } 8451 assert(!NE.isUnset() &&((void)0) 8452 "Typo was transformed into a valid-but-null ExprResult")((void)0); 8453 return CacheEntry = NE; 8454 } 8455 } 8456 return CacheEntry = ExprError(); 8457 } 8458}; 8459} 8460 8461ExprResult 8462Sema::CorrectDelayedTyposInExpr(Expr *E, VarDecl *InitDecl, 8463 bool RecoverUncorrectedTypos, 8464 llvm::function_ref<ExprResult(Expr *)> Filter) { 8465 // If the current evaluation context indicates there are uncorrected typos 8466 // and the current expression isn't guaranteed to not have typos, try to 8467 // resolve any TypoExpr nodes that might be in the expression. 8468 if (E && !ExprEvalContexts.empty() && ExprEvalContexts.back().NumTypos && 8469 (E->isTypeDependent() || E->isValueDependent() || 8470 E->isInstantiationDependent())) { 8471 auto TyposResolved = DelayedTypos.size(); 8472 auto Result = TransformTypos(*this, InitDecl, Filter).Transform(E); 8473 TyposResolved -= DelayedTypos.size(); 8474 if (Result.isInvalid() || Result.get() != E) { 8475 ExprEvalContexts.back().NumTypos -= TyposResolved; 8476 if (Result.isInvalid() && RecoverUncorrectedTypos) { 8477 struct TyposReplace : TreeTransform<TyposReplace> { 8478 TyposReplace(Sema &SemaRef) : TreeTransform(SemaRef) {} 8479 ExprResult TransformTypoExpr(clang::TypoExpr *E) { 8480 return this->SemaRef.CreateRecoveryExpr(E->getBeginLoc(), 8481 E->getEndLoc(), {}); 8482 } 8483 } TT(*this); 8484 return TT.TransformExpr(E); 8485 } 8486 return Result; 8487 } 8488 assert(TyposResolved == 0 && "Corrected typo but got same Expr back?")((void)0); 8489 } 8490 return E; 8491} 8492 8493ExprResult Sema::ActOnFinishFullExpr(Expr *FE, SourceLocation CC, 8494 bool DiscardedValue, 8495 bool IsConstexpr) { 8496 ExprResult FullExpr = FE; 8497 8498 if (!FullExpr.get()) 8499 return ExprError(); 8500 8501 if (DiagnoseUnexpandedParameterPack(FullExpr.get())) 8502 return ExprError(); 8503 8504 if (DiscardedValue) { 8505 // Top-level expressions default to 'id' when we're in a debugger. 8506 if (getLangOpts().DebuggerCastResultToId && 8507 FullExpr.get()->getType() == Context.UnknownAnyTy) { 8508 FullExpr = forceUnknownAnyToType(FullExpr.get(), Context.getObjCIdType()); 8509 if (FullExpr.isInvalid()) 8510 return ExprError(); 8511 } 8512 8513 FullExpr = CheckPlaceholderExpr(FullExpr.get()); 8514 if (FullExpr.isInvalid()) 8515 return ExprError(); 8516 8517 FullExpr = IgnoredValueConversions(FullExpr.get()); 8518 if (FullExpr.isInvalid()) 8519 return ExprError(); 8520 8521 DiagnoseUnusedExprResult(FullExpr.get()); 8522 } 8523 8524 FullExpr = CorrectDelayedTyposInExpr(FullExpr.get(), /*InitDecl=*/nullptr, 8525 /*RecoverUncorrectedTypos=*/true); 8526 if (FullExpr.isInvalid()) 8527 return ExprError(); 8528 8529 CheckCompletedExpr(FullExpr.get(), CC, IsConstexpr); 8530 8531 // At the end of this full expression (which could be a deeply nested 8532 // lambda), if there is a potential capture within the nested lambda, 8533 // have the outer capture-able lambda try and capture it. 8534 // Consider the following code: 8535 // void f(int, int); 8536 // void f(const int&, double); 8537 // void foo() { 8538 // const int x = 10, y = 20; 8539 // auto L = [=](auto a) { 8540 // auto M = [=](auto b) { 8541 // f(x, b); <-- requires x to be captured by L and M 8542 // f(y, a); <-- requires y to be captured by L, but not all Ms 8543 // }; 8544 // }; 8545 // } 8546 8547 // FIXME: Also consider what happens for something like this that involves 8548 // the gnu-extension statement-expressions or even lambda-init-captures: 8549 // void f() { 8550 // const int n = 0; 8551 // auto L = [&](auto a) { 8552 // +n + ({ 0; a; }); 8553 // }; 8554 // } 8555 // 8556 // Here, we see +n, and then the full-expression 0; ends, so we don't 8557 // capture n (and instead remove it from our list of potential captures), 8558 // and then the full-expression +n + ({ 0; }); ends, but it's too late 8559 // for us to see that we need to capture n after all. 8560 8561 LambdaScopeInfo *const CurrentLSI = 8562 getCurLambda(/*IgnoreCapturedRegions=*/true); 8563 // FIXME: PR 17877 showed that getCurLambda() can return a valid pointer 8564 // even if CurContext is not a lambda call operator. Refer to that Bug Report 8565 // for an example of the code that might cause this asynchrony. 8566 // By ensuring we are in the context of a lambda's call operator 8567 // we can fix the bug (we only need to check whether we need to capture 8568 // if we are within a lambda's body); but per the comments in that 8569 // PR, a proper fix would entail : 8570 // "Alternative suggestion: 8571 // - Add to Sema an integer holding the smallest (outermost) scope 8572 // index that we are *lexically* within, and save/restore/set to 8573 // FunctionScopes.size() in InstantiatingTemplate's 8574 // constructor/destructor. 8575 // - Teach the handful of places that iterate over FunctionScopes to 8576 // stop at the outermost enclosing lexical scope." 8577 DeclContext *DC = CurContext; 8578 while (DC && isa<CapturedDecl>(DC)) 8579 DC = DC->getParent(); 8580 const bool IsInLambdaDeclContext = isLambdaCallOperator(DC); 8581 if (IsInLambdaDeclContext && CurrentLSI && 8582 CurrentLSI->hasPotentialCaptures() && !FullExpr.isInvalid()) 8583 CheckIfAnyEnclosingLambdasMustCaptureAnyPotentialCaptures(FE, CurrentLSI, 8584 *this); 8585 return MaybeCreateExprWithCleanups(FullExpr); 8586} 8587 8588StmtResult Sema::ActOnFinishFullStmt(Stmt *FullStmt) { 8589 if (!FullStmt) return StmtError(); 8590 8591 return MaybeCreateStmtWithCleanups(FullStmt); 8592} 8593 8594Sema::IfExistsResult 8595Sema::CheckMicrosoftIfExistsSymbol(Scope *S, 8596 CXXScopeSpec &SS, 8597 const DeclarationNameInfo &TargetNameInfo) { 8598 DeclarationName TargetName = TargetNameInfo.getName(); 8599 if (!TargetName) 8600 return IER_DoesNotExist; 8601 8602 // If the name itself is dependent, then the result is dependent. 8603 if (TargetName.isDependentName()) 8604 return IER_Dependent; 8605 8606 // Do the redeclaration lookup in the current scope. 8607 LookupResult R(*this, TargetNameInfo, Sema::LookupAnyName, 8608 Sema::NotForRedeclaration); 8609 LookupParsedName(R, S, &SS); 8610 R.suppressDiagnostics(); 8611 8612 switch (R.getResultKind()) { 8613 case LookupResult::Found: 8614 case LookupResult::FoundOverloaded: 8615 case LookupResult::FoundUnresolvedValue: 8616 case LookupResult::Ambiguous: 8617 return IER_Exists; 8618 8619 case LookupResult::NotFound: 8620 return IER_DoesNotExist; 8621 8622 case LookupResult::NotFoundInCurrentInstantiation: 8623 return IER_Dependent; 8624 } 8625 8626 llvm_unreachable("Invalid LookupResult Kind!")__builtin_unreachable(); 8627} 8628 8629Sema::IfExistsResult 8630Sema::CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc, 8631 bool IsIfExists, CXXScopeSpec &SS, 8632 UnqualifiedId &Name) { 8633 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 8634 8635 // Check for an unexpanded parameter pack. 8636 auto UPPC = IsIfExists ? UPPC_IfExists : UPPC_IfNotExists; 8637 if (DiagnoseUnexpandedParameterPack(SS, UPPC) || 8638 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC)) 8639 return IER_Error; 8640 8641 return CheckMicrosoftIfExistsSymbol(S, SS, TargetNameInfo); 8642} 8643 8644concepts::Requirement *Sema::ActOnSimpleRequirement(Expr *E) { 8645 return BuildExprRequirement(E, /*IsSimple=*/true, 8646 /*NoexceptLoc=*/SourceLocation(), 8647 /*ReturnTypeRequirement=*/{}); 8648} 8649 8650concepts::Requirement * 8651Sema::ActOnTypeRequirement(SourceLocation TypenameKWLoc, CXXScopeSpec &SS, 8652 SourceLocation NameLoc, IdentifierInfo *TypeName, 8653 TemplateIdAnnotation *TemplateId) { 8654 assert(((!TypeName && TemplateId) || (TypeName && !TemplateId)) &&((void)0) 8655 "Exactly one of TypeName and TemplateId must be specified.")((void)0); 8656 TypeSourceInfo *TSI = nullptr; 8657 if (TypeName) { 8658 QualType T = CheckTypenameType(ETK_Typename, TypenameKWLoc, 8659 SS.getWithLocInContext(Context), *TypeName, 8660 NameLoc, &TSI, /*DeducedTypeContext=*/false); 8661 if (T.isNull()) 8662 return nullptr; 8663 } else { 8664 ASTTemplateArgsPtr ArgsPtr(TemplateId->getTemplateArgs(), 8665 TemplateId->NumArgs); 8666 TypeResult T = ActOnTypenameType(CurScope, TypenameKWLoc, SS, 8667 TemplateId->TemplateKWLoc, 8668 TemplateId->Template, TemplateId->Name, 8669 TemplateId->TemplateNameLoc, 8670 TemplateId->LAngleLoc, ArgsPtr, 8671 TemplateId->RAngleLoc); 8672 if (T.isInvalid()) 8673 return nullptr; 8674 if (GetTypeFromParser(T.get(), &TSI).isNull()) 8675 return nullptr; 8676 } 8677 return BuildTypeRequirement(TSI); 8678} 8679 8680concepts::Requirement * 8681Sema::ActOnCompoundRequirement(Expr *E, SourceLocation NoexceptLoc) { 8682 return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, 8683 /*ReturnTypeRequirement=*/{}); 8684} 8685 8686concepts::Requirement * 8687Sema::ActOnCompoundRequirement( 8688 Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS, 8689 TemplateIdAnnotation *TypeConstraint, unsigned Depth) { 8690 // C++2a [expr.prim.req.compound] p1.3.3 8691 // [..] the expression is deduced against an invented function template 8692 // F [...] F is a void function template with a single type template 8693 // parameter T declared with the constrained-parameter. Form a new 8694 // cv-qualifier-seq cv by taking the union of const and volatile specifiers 8695 // around the constrained-parameter. F has a single parameter whose 8696 // type-specifier is cv T followed by the abstract-declarator. [...] 8697 // 8698 // The cv part is done in the calling function - we get the concept with 8699 // arguments and the abstract declarator with the correct CV qualification and 8700 // have to synthesize T and the single parameter of F. 8701 auto &II = Context.Idents.get("expr-type"); 8702 auto *TParam = TemplateTypeParmDecl::Create(Context, CurContext, 8703 SourceLocation(), 8704 SourceLocation(), Depth, 8705 /*Index=*/0, &II, 8706 /*Typename=*/true, 8707 /*ParameterPack=*/false, 8708 /*HasTypeConstraint=*/true); 8709 8710 if (BuildTypeConstraint(SS, TypeConstraint, TParam, 8711 /*EllpsisLoc=*/SourceLocation(), 8712 /*AllowUnexpandedPack=*/true)) 8713 // Just produce a requirement with no type requirements. 8714 return BuildExprRequirement(E, /*IsSimple=*/false, NoexceptLoc, {}); 8715 8716 auto *TPL = TemplateParameterList::Create(Context, SourceLocation(), 8717 SourceLocation(), 8718 ArrayRef<NamedDecl *>(TParam), 8719 SourceLocation(), 8720 /*RequiresClause=*/nullptr); 8721 return BuildExprRequirement( 8722 E, /*IsSimple=*/false, NoexceptLoc, 8723 concepts::ExprRequirement::ReturnTypeRequirement(TPL)); 8724} 8725 8726concepts::ExprRequirement * 8727Sema::BuildExprRequirement( 8728 Expr *E, bool IsSimple, SourceLocation NoexceptLoc, 8729 concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) { 8730 auto Status = concepts::ExprRequirement::SS_Satisfied; 8731 ConceptSpecializationExpr *SubstitutedConstraintExpr = nullptr; 8732 if (E->isInstantiationDependent() || ReturnTypeRequirement.isDependent()) 8733 Status = concepts::ExprRequirement::SS_Dependent; 8734 else if (NoexceptLoc.isValid() && canThrow(E) == CanThrowResult::CT_Can) 8735 Status = concepts::ExprRequirement::SS_NoexceptNotMet; 8736 else if (ReturnTypeRequirement.isSubstitutionFailure()) 8737 Status = concepts::ExprRequirement::SS_TypeRequirementSubstitutionFailure; 8738 else if (ReturnTypeRequirement.isTypeConstraint()) { 8739 // C++2a [expr.prim.req]p1.3.3 8740 // The immediately-declared constraint ([temp]) of decltype((E)) shall 8741 // be satisfied. 8742 TemplateParameterList *TPL = 8743 ReturnTypeRequirement.getTypeConstraintTemplateParameterList(); 8744 QualType MatchedType = 8745 getDecltypeForParenthesizedExpr(E).getCanonicalType(); 8746 llvm::SmallVector<TemplateArgument, 1> Args; 8747 Args.push_back(TemplateArgument(MatchedType)); 8748 TemplateArgumentList TAL(TemplateArgumentList::OnStack, Args); 8749 MultiLevelTemplateArgumentList MLTAL(TAL); 8750 for (unsigned I = 0; I < TPL->getDepth(); ++I) 8751 MLTAL.addOuterRetainedLevel(); 8752 Expr *IDC = 8753 cast<TemplateTypeParmDecl>(TPL->getParam(0))->getTypeConstraint() 8754 ->getImmediatelyDeclaredConstraint(); 8755 ExprResult Constraint = SubstExpr(IDC, MLTAL); 8756 assert(!Constraint.isInvalid() &&((void)0) 8757 "Substitution cannot fail as it is simply putting a type template "((void)0) 8758 "argument into a concept specialization expression's parameter.")((void)0); 8759 8760 SubstitutedConstraintExpr = 8761 cast<ConceptSpecializationExpr>(Constraint.get()); 8762 if (!SubstitutedConstraintExpr->isSatisfied()) 8763 Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied; 8764 } 8765 return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc, 8766 ReturnTypeRequirement, Status, 8767 SubstitutedConstraintExpr); 8768} 8769 8770concepts::ExprRequirement * 8771Sema::BuildExprRequirement( 8772 concepts::Requirement::SubstitutionDiagnostic *ExprSubstitutionDiagnostic, 8773 bool IsSimple, SourceLocation NoexceptLoc, 8774 concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement) { 8775 return new (Context) concepts::ExprRequirement(ExprSubstitutionDiagnostic, 8776 IsSimple, NoexceptLoc, 8777 ReturnTypeRequirement); 8778} 8779 8780concepts::TypeRequirement * 8781Sema::BuildTypeRequirement(TypeSourceInfo *Type) { 8782 return new (Context) concepts::TypeRequirement(Type); 8783} 8784 8785concepts::TypeRequirement * 8786Sema::BuildTypeRequirement( 8787 concepts::Requirement::SubstitutionDiagnostic *SubstDiag) { 8788 return new (Context) concepts::TypeRequirement(SubstDiag); 8789} 8790 8791concepts::Requirement *Sema::ActOnNestedRequirement(Expr *Constraint) { 8792 return BuildNestedRequirement(Constraint); 8793} 8794 8795concepts::NestedRequirement * 8796Sema::BuildNestedRequirement(Expr *Constraint) { 8797 ConstraintSatisfaction Satisfaction; 8798 if (!Constraint->isInstantiationDependent() && 8799 CheckConstraintSatisfaction(nullptr, {Constraint}, /*TemplateArgs=*/{}, 8800 Constraint->getSourceRange(), Satisfaction)) 8801 return nullptr; 8802 return new (Context) concepts::NestedRequirement(Context, Constraint, 8803 Satisfaction); 8804} 8805 8806concepts::NestedRequirement * 8807Sema::BuildNestedRequirement( 8808 concepts::Requirement::SubstitutionDiagnostic *SubstDiag) { 8809 return new (Context) concepts::NestedRequirement(SubstDiag); 8810} 8811 8812RequiresExprBodyDecl * 8813Sema::ActOnStartRequiresExpr(SourceLocation RequiresKWLoc, 8814 ArrayRef<ParmVarDecl *> LocalParameters, 8815 Scope *BodyScope) { 8816 assert(BodyScope)((void)0); 8817 8818 RequiresExprBodyDecl *Body = RequiresExprBodyDecl::Create(Context, CurContext, 8819 RequiresKWLoc); 8820 8821 PushDeclContext(BodyScope, Body); 8822 8823 for (ParmVarDecl *Param : LocalParameters) { 8824 if (Param->hasDefaultArg()) 8825 // C++2a [expr.prim.req] p4 8826 // [...] A local parameter of a requires-expression shall not have a 8827 // default argument. [...] 8828 Diag(Param->getDefaultArgRange().getBegin(), 8829 diag::err_requires_expr_local_parameter_default_argument); 8830 // Ignore default argument and move on 8831 8832 Param->setDeclContext(Body); 8833 // If this has an identifier, add it to the scope stack. 8834 if (Param->getIdentifier()) { 8835 CheckShadow(BodyScope, Param); 8836 PushOnScopeChains(Param, BodyScope); 8837 } 8838 } 8839 return Body; 8840} 8841 8842void Sema::ActOnFinishRequiresExpr() { 8843 assert(CurContext && "DeclContext imbalance!")((void)0); 8844 CurContext = CurContext->getLexicalParent(); 8845 assert(CurContext && "Popped translation unit!")((void)0); 8846} 8847 8848ExprResult 8849Sema::ActOnRequiresExpr(SourceLocation RequiresKWLoc, 8850 RequiresExprBodyDecl *Body, 8851 ArrayRef<ParmVarDecl *> LocalParameters, 8852 ArrayRef<concepts::Requirement *> Requirements, 8853 SourceLocation ClosingBraceLoc) { 8854 auto *RE = RequiresExpr::Create(Context, RequiresKWLoc, Body, LocalParameters, 8855 Requirements, ClosingBraceLoc); 8856 if (DiagnoseUnexpandedParameterPackInRequiresExpr(RE)) 8857 return ExprError(); 8858 return RE; 8859}

←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/Sema/Sema.h

1//===--- Sema.h - Semantic Analysis & AST Building --------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file defines the Sema class, which performs semantic analysis and
10// builds ASTs.
11//
12//===----------------------------------------------------------------------===//

14#ifndef LLVM_CLANG_SEMA_SEMA_H
15#define LLVM_CLANG_SEMA_SEMA_H

17#include "clang/AST/ASTConcept.h"
18#include "clang/AST/ASTFwd.h"
19#include "clang/AST/Attr.h"
20#include "clang/AST/Availability.h"
21#include "clang/AST/ComparisonCategories.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/DeclarationName.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/ExprConcepts.h"
27#include "clang/AST/ExprObjC.h"
28#include "clang/AST/ExprOpenMP.h"
29#include "clang/AST/ExternalASTSource.h"
30#include "clang/AST/LocInfoType.h"
31#include "clang/AST/MangleNumberingContext.h"
32#include "clang/AST/NSAPI.h"
33#include "clang/AST/PrettyPrinter.h"
34#include "clang/AST/StmtCXX.h"
35#include "clang/AST/StmtOpenMP.h"
36#include "clang/AST/TypeLoc.h"
37#include "clang/AST/TypeOrdering.h"
38#include "clang/Basic/BitmaskEnum.h"
39#include "clang/Basic/Builtins.h"
40#include "clang/Basic/DarwinSDKInfo.h"
41#include "clang/Basic/ExpressionTraits.h"
42#include "clang/Basic/Module.h"
43#include "clang/Basic/OpenCLOptions.h"
44#include "clang/Basic/OpenMPKinds.h"
45#include "clang/Basic/PragmaKinds.h"
46#include "clang/Basic/Specifiers.h"
47#include "clang/Basic/TemplateKinds.h"
48#include "clang/Basic/TypeTraits.h"
49#include "clang/Sema/AnalysisBasedWarnings.h"
50#include "clang/Sema/CleanupInfo.h"
51#include "clang/Sema/DeclSpec.h"
52#include "clang/Sema/ExternalSemaSource.h"
53#include "clang/Sema/IdentifierResolver.h"
54#include "clang/Sema/ObjCMethodList.h"
55#include "clang/Sema/Ownership.h"
56#include "clang/Sema/Scope.h"
57#include "clang/Sema/SemaConcept.h"
58#include "clang/Sema/TypoCorrection.h"
59#include "clang/Sema/Weak.h"
60#include "llvm/ADT/ArrayRef.h"
61#include "llvm/ADT/Optional.h"
62#include "llvm/ADT/SetVector.h"
63#include "llvm/ADT/SmallBitVector.h"
64#include "llvm/ADT/SmallPtrSet.h"
65#include "llvm/ADT/SmallSet.h"
66#include "llvm/ADT/SmallVector.h"
67#include "llvm/ADT/TinyPtrVector.h"
68#include "llvm/Frontend/OpenMP/OMPConstants.h"
69#include <deque>
70#include <memory>
71#include <string>
72#include <tuple>
73#include <vector>

75namespace llvm {
class APSInt;
template <typename ValueT> struct DenseMapInfo;
template <typename ValueT, typename ValueInfoT> class DenseSet;
class SmallBitVector;
struct InlineAsmIdentifierInfo;
81}

83namespace clang {
class ADLResult;
class ASTConsumer;
class ASTContext;
class ASTMutationListener;
class ASTReader;
class ASTWriter;
class ArrayType;
class ParsedAttr;
class BindingDecl;
class BlockDecl;
class CapturedDecl;
class CXXBasePath;
class CXXBasePaths;
class CXXBindTemporaryExpr;
typedef SmallVector<CXXBaseSpecifier*, 4> CXXCastPath;
class CXXConstructorDecl;
class CXXConversionDecl;
class CXXDeleteExpr;
class CXXDestructorDecl;
class CXXFieldCollector;
class CXXMemberCallExpr;
class CXXMethodDecl;
class CXXScopeSpec;
class CXXTemporary;
class CXXTryStmt;
class CallExpr;
class ClassTemplateDecl;
class ClassTemplatePartialSpecializationDecl;
class ClassTemplateSpecializationDecl;
class VarTemplatePartialSpecializationDecl;
class CodeCompleteConsumer;
class CodeCompletionAllocator;
class CodeCompletionTUInfo;
class CodeCompletionResult;
class CoroutineBodyStmt;
class Decl;
class DeclAccessPair;
class DeclContext;
class DeclRefExpr;
class DeclaratorDecl;
class DeducedTemplateArgument;
class DependentDiagnostic;
class DesignatedInitExpr;
class Designation;
class EnableIfAttr;
class EnumConstantDecl;
class Expr;
class ExtVectorType;
class FormatAttr;
class FriendDecl;
class FunctionDecl;
class FunctionProtoType;
class FunctionTemplateDecl;
class ImplicitConversionSequence;
typedef MutableArrayRef<ImplicitConversionSequence> ConversionSequenceList;
class InitListExpr;
class InitializationKind;
class InitializationSequence;
class InitializedEntity;
class IntegerLiteral;
class LabelStmt;
class LambdaExpr;
class LangOptions;
class LocalInstantiationScope;
class LookupResult;
class MacroInfo;
typedef ArrayRef<std::pair<IdentifierInfo *, SourceLocation>> ModuleIdPath;
class ModuleLoader;
class MultiLevelTemplateArgumentList;
class NamedDecl;
class ObjCCategoryDecl;
class ObjCCategoryImplDecl;
class ObjCCompatibleAliasDecl;
class ObjCContainerDecl;
class ObjCImplDecl;
class ObjCImplementationDecl;
class ObjCInterfaceDecl;
class ObjCIvarDecl;
template <class T> class ObjCList;
class ObjCMessageExpr;
class ObjCMethodDecl;
class ObjCPropertyDecl;
class ObjCProtocolDecl;
class OMPThreadPrivateDecl;
class OMPRequiresDecl;
class OMPDeclareReductionDecl;
class OMPDeclareSimdDecl;
class OMPClause;
struct OMPVarListLocTy;
struct OverloadCandidate;
enum class OverloadCandidateParamOrder : char;
enum OverloadCandidateRewriteKind : unsigned;
class OverloadCandidateSet;
class OverloadExpr;
class ParenListExpr;
class ParmVarDecl;
class Preprocessor;
class PseudoDestructorTypeStorage;
class PseudoObjectExpr;
class QualType;
class StandardConversionSequence;
class Stmt;
class StringLiteral;
class SwitchStmt;
class TemplateArgument;
class TemplateArgumentList;
class TemplateArgumentLoc;
class TemplateDecl;
class TemplateInstantiationCallback;
class TemplateParameterList;
class TemplatePartialOrderingContext;
class TemplateTemplateParmDecl;
class Token;
class TypeAliasDecl;
class TypedefDecl;
class TypedefNameDecl;
class TypeLoc;
class TypoCorrectionConsumer;
class UnqualifiedId;
class UnresolvedLookupExpr;
class UnresolvedMemberExpr;
class UnresolvedSetImpl;
class UnresolvedSetIterator;
class UsingDecl;
class UsingShadowDecl;
class ValueDecl;
class VarDecl;
class VarTemplateSpecializationDecl;
class VisibilityAttr;
class VisibleDeclConsumer;
class IndirectFieldDecl;
struct DeductionFailureInfo;
class TemplateSpecCandidateSet;

218namespace sema {
class AccessedEntity;
class BlockScopeInfo;
class Capture;
class CapturedRegionScopeInfo;
class CapturingScopeInfo;
class CompoundScopeInfo;
class DelayedDiagnostic;
class DelayedDiagnosticPool;
class FunctionScopeInfo;
class LambdaScopeInfo;
class PossiblyUnreachableDiag;
class SemaPPCallbacks;
class TemplateDeductionInfo;
232}

234namespace threadSafety {
class BeforeSet;
void threadSafetyCleanup(BeforeSet* Cache);
237}

239// FIXME: No way to easily map from TemplateTypeParmTypes to
240// TemplateTypeParmDecls, so we have this horrible PointerUnion.
241typedef std::pair<llvm::PointerUnion<const TemplateTypeParmType*, NamedDecl*>,
                SourceLocation> UnexpandedParameterPack;

244/// Describes whether we've seen any nullability information for the given
245/// file.
246struct FileNullability {
/// The first pointer declarator (of any pointer kind) in the file that does
/// not have a corresponding nullability annotation.
SourceLocation PointerLoc;

/// The end location for the first pointer declarator in the file. Used for
/// placing fix-its.
SourceLocation PointerEndLoc;

/// Which kind of pointer declarator we saw.
uint8_t PointerKind;

/// Whether we saw any type nullability annotations in the given file.
bool SawTypeNullability = false;
260};

262/// A mapping from file IDs to a record of whether we've seen nullability
263/// information in that file.
264class FileNullabilityMap {
/// A mapping from file IDs to the nullability information for each file ID.
llvm::DenseMap<FileID, FileNullability> Map;

/// A single-element cache based on the file ID.
struct {
  FileID File;
  FileNullability Nullability;
} Cache;

274public:
FileNullability &operator[](FileID file) {
  // Check the single-element cache.
  if (file == Cache.File)
    return Cache.Nullability;

  // It's not in the single-element cache; flush the cache if we have one.
  if (!Cache.File.isInvalid()) {
    Map[Cache.File] = Cache.Nullability;
  }

  // Pull this entry into the cache.
  Cache.File = file;
  Cache.Nullability = Map[file];
  return Cache.Nullability;
}
290};

292/// Tracks expected type during expression parsing, for use in code completion.
293/// The type is tied to a particular token, all functions that update or consume
294/// the type take a start location of the token they are looking at as a
295/// parameter. This avoids updating the type on hot paths in the parser.
296class PreferredTypeBuilder {
297public:
PreferredTypeBuilder(bool Enabled) : Enabled(Enabled) {}

void enterCondition(Sema &S, SourceLocation Tok);
void enterReturn(Sema &S, SourceLocation Tok);
void enterVariableInit(SourceLocation Tok, Decl *D);
/// Handles e.g. BaseType{ .D = Tok...
void enterDesignatedInitializer(SourceLocation Tok, QualType BaseType,
                                const Designation &D);
/// Computing a type for the function argument may require running
/// overloading, so we postpone its computation until it is actually needed.
///
/// Clients should be very careful when using this funciton, as it stores a
/// function_ref, clients should make sure all calls to get() with the same
/// location happen while function_ref is alive.
///
/// The callback should also emit signature help as a side-effect, but only
/// if the completion point has been reached.
void enterFunctionArgument(SourceLocation Tok,
                           llvm::function_ref<QualType()> ComputeType);

void enterParenExpr(SourceLocation Tok, SourceLocation LParLoc);
void enterUnary(Sema &S, SourceLocation Tok, tok::TokenKind OpKind,
                SourceLocation OpLoc);
void enterBinary(Sema &S, SourceLocation Tok, Expr *LHS, tok::TokenKind Op);
void enterMemAccess(Sema &S, SourceLocation Tok, Expr *Base);
void enterSubscript(Sema &S, SourceLocation Tok, Expr *LHS);
/// Handles all type casts, including C-style cast, C++ casts, etc.
void enterTypeCast(SourceLocation Tok, QualType CastType);

/// Get the expected type associated with this location, if any.
///
/// If the location is a function argument, determining the expected type
/// involves considering all function overloads and the arguments so far.
/// In this case, signature help for these function overloads will be reported
/// as a side-effect (only if the completion point has been reached).
QualType get(SourceLocation Tok) const {
  if (!Enabled || Tok != ExpectedLoc)
    return QualType();
  if (!Type.isNull())
    return Type;
  if (ComputeType)
    return ComputeType();
  return QualType();
}

343private:
bool Enabled;
/// Start position of a token for which we store expected type.
SourceLocation ExpectedLoc;
/// Expected type for a token starting at ExpectedLoc.
QualType Type;
/// A function to compute expected type at ExpectedLoc. It is only considered
/// if Type is null.
llvm::function_ref<QualType()> ComputeType;
352};

354/// Sema - This implements semantic analysis and AST building for C.
355class Sema final {
Sema(const Sema &) = delete;
void operator=(const Sema &) = delete;

///Source of additional semantic information.
ExternalSemaSource *ExternalSource;

///Whether Sema has generated a multiplexer and has to delete it.
bool isMultiplexExternalSource;

static bool mightHaveNonExternalLinkage(const DeclaratorDecl *FD);

bool isVisibleSlow(const NamedDecl *D);

/// Determine whether two declarations should be linked together, given that
/// the old declaration might not be visible and the new declaration might
/// not have external linkage.
bool shouldLinkPossiblyHiddenDecl(const NamedDecl *Old,
                                  const NamedDecl *New) {
  if (isVisible(Old))
   return true;
  // See comment in below overload for why it's safe to compute the linkage
  // of the new declaration here.
  if (New->isExternallyDeclarable()) {
    assert(Old->isExternallyDeclarable() &&((void)0)
           "should not have found a non-externally-declarable previous decl")((void)0);
    return true;
  }
  return false;
}
bool shouldLinkPossiblyHiddenDecl(LookupResult &Old, const NamedDecl *New);

void setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
                                    QualType ResultTy,
                                    ArrayRef<QualType> Args);

391public:
/// The maximum alignment, same as in llvm::Value. We duplicate them here
/// because that allows us not to duplicate the constants in clang code,
/// which we must to since we can't directly use the llvm constants.
/// The value is verified against llvm here: lib/CodeGen/CGDecl.cpp
///
/// This is the greatest alignment value supported by load, store, and alloca
/// instructions, and global values.
static const unsigned MaxAlignmentExponent = 29;
static const unsigned MaximumAlignment = 1u << MaxAlignmentExponent;

typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy;
typedef OpaquePtr<TemplateName> TemplateTy;
typedef OpaquePtr<QualType> TypeTy;

OpenCLOptions OpenCLFeatures;
FPOptions CurFPFeatures;

const LangOptions &LangOpts;
Preprocessor &PP;
ASTContext &Context;
ASTConsumer &Consumer;
DiagnosticsEngine &Diags;
SourceManager &SourceMgr;

/// Flag indicating whether or not to collect detailed statistics.
bool CollectStats;

/// Code-completion consumer.
CodeCompleteConsumer *CodeCompleter;

/// CurContext - This is the current declaration context of parsing.
DeclContext *CurContext;

/// Generally null except when we temporarily switch decl contexts,
/// like in \see ActOnObjCTemporaryExitContainerContext.
DeclContext *OriginalLexicalContext;

/// VAListTagName - The declaration name corresponding to __va_list_tag.
/// This is used as part of a hack to omit that class from ADL results.
DeclarationName VAListTagName;

bool MSStructPragmaOn; // True when \#pragma ms_struct on

/// Controls member pointer representation format under the MS ABI.
LangOptions::PragmaMSPointersToMembersKind
    MSPointerToMemberRepresentationMethod;

/// Stack of active SEH __finally scopes.  Can be empty.
SmallVector<Scope*, 2> CurrentSEHFinally;

/// Source location for newly created implicit MSInheritanceAttrs
SourceLocation ImplicitMSInheritanceAttrLoc;

/// Holds TypoExprs that are created from `createDelayedTypo`. This is used by
/// `TransformTypos` in order to keep track of any TypoExprs that are created
/// recursively during typo correction and wipe them away if the correction
/// fails.
llvm::SmallVector<TypoExpr *, 2> TypoExprs;

/// pragma clang section kind
enum PragmaClangSectionKind {
  PCSK_Invalid      = 0,
  PCSK_BSS          = 1,
  PCSK_Data         = 2,
  PCSK_Rodata       = 3,
  PCSK_Text         = 4,
  PCSK_Relro        = 5
 };

enum PragmaClangSectionAction {
  PCSA_Set     = 0,
  PCSA_Clear   = 1
};

struct PragmaClangSection {
  std::string SectionName;
  bool Valid = false;
  SourceLocation PragmaLocation;
};

 PragmaClangSection PragmaClangBSSSection;
 PragmaClangSection PragmaClangDataSection;
 PragmaClangSection PragmaClangRodataSection;
 PragmaClangSection PragmaClangRelroSection;
 PragmaClangSection PragmaClangTextSection;

enum PragmaMsStackAction {
  PSK_Reset     = 0x0,                // #pragma ()
  PSK_Set       = 0x1,                // #pragma (value)
  PSK_Push      = 0x2,                // #pragma (push[, id])
  PSK_Pop       = 0x4,                // #pragma (pop[, id])
  PSK_Show      = 0x8,                // #pragma (show) -- only for "pack"!
  PSK_Push_Set  = PSK_Push | PSK_Set, // #pragma (push[, id], value)
  PSK_Pop_Set   = PSK_Pop | PSK_Set,  // #pragma (pop[, id], value)
};

// #pragma pack and align.
class AlignPackInfo {
public:
  // `Native` represents default align mode, which may vary based on the
  // platform.
  enum Mode : unsigned char { Native, Natural, Packed, Mac68k };

  // #pragma pack info constructor
  AlignPackInfo(AlignPackInfo::Mode M, unsigned Num, bool IsXL)
      : PackAttr(true), AlignMode(M), PackNumber(Num), XLStack(IsXL) {
    assert(Num == PackNumber && "The pack number has been truncated.")((void)0);
  }

  // #pragma align info constructor
  AlignPackInfo(AlignPackInfo::Mode M, bool IsXL)
      : PackAttr(false), AlignMode(M),
        PackNumber(M == Packed ? 1 : UninitPackVal), XLStack(IsXL) {}

  explicit AlignPackInfo(bool IsXL) : AlignPackInfo(Native, IsXL) {}

  AlignPackInfo() : AlignPackInfo(Native, false) {}

  // When a AlignPackInfo itself cannot be used, this returns an 32-bit
  // integer encoding for it. This should only be passed to
  // AlignPackInfo::getFromRawEncoding, it should not be inspected directly.
  static uint32_t getRawEncoding(const AlignPackInfo &Info) {
    std::uint32_t Encoding{};
    if (Info.IsXLStack())
      Encoding |= IsXLMask;

    Encoding |= static_cast<uint32_t>(Info.getAlignMode()) << 1;

    if (Info.IsPackAttr())
      Encoding |= PackAttrMask;

    Encoding |= static_cast<uint32_t>(Info.getPackNumber()) << 4;

    return Encoding;
  }

  static AlignPackInfo getFromRawEncoding(unsigned Encoding) {
    bool IsXL = static_cast<bool>(Encoding & IsXLMask);
    AlignPackInfo::Mode M =
        static_cast<AlignPackInfo::Mode>((Encoding & AlignModeMask) >> 1);
    int PackNumber = (Encoding & PackNumMask) >> 4;

    if (Encoding & PackAttrMask)
      return AlignPackInfo(M, PackNumber, IsXL);

    return AlignPackInfo(M, IsXL);
  }

  bool IsPackAttr() const { return PackAttr; }

  bool IsAlignAttr() const { return !PackAttr; }

  Mode getAlignMode() const { return AlignMode; }

  unsigned getPackNumber() const { return PackNumber; }

  bool IsPackSet() const {
    // #pragma align, #pragma pack(), and #pragma pack(0) do not set the pack
    // attriute on a decl.
    return PackNumber != UninitPackVal && PackNumber != 0;
  }

  bool IsXLStack() const { return XLStack; }

  bool operator==(const AlignPackInfo &Info) const {
    return std::tie(AlignMode, PackNumber, PackAttr, XLStack) ==
           std::tie(Info.AlignMode, Info.PackNumber, Info.PackAttr,
                    Info.XLStack);
  }

  bool operator!=(const AlignPackInfo &Info) const {
    return !(*this == Info);
  }

private:
  /// \brief True if this is a pragma pack attribute,
  ///         not a pragma align attribute.
  bool PackAttr;

  /// \brief The alignment mode that is in effect.
  Mode AlignMode;

  /// \brief The pack number of the stack.
  unsigned char PackNumber;

  /// \brief True if it is a XL #pragma align/pack stack.
  bool XLStack;

  /// \brief Uninitialized pack value.
  static constexpr unsigned char UninitPackVal = -1;

  // Masks to encode and decode an AlignPackInfo.
  static constexpr uint32_t IsXLMask{0x0000'0001};
  static constexpr uint32_t AlignModeMask{0x0000'0006};
  static constexpr uint32_t PackAttrMask{0x00000'0008};
  static constexpr uint32_t PackNumMask{0x0000'01F0};
};

template<typename ValueType>
struct PragmaStack {
  struct Slot {
    llvm::StringRef StackSlotLabel;
    ValueType Value;
    SourceLocation PragmaLocation;
    SourceLocation PragmaPushLocation;
    Slot(llvm::StringRef StackSlotLabel, ValueType Value,
         SourceLocation PragmaLocation, SourceLocation PragmaPushLocation)
        : StackSlotLabel(StackSlotLabel), Value(Value),
          PragmaLocation(PragmaLocation),
          PragmaPushLocation(PragmaPushLocation) {}
  };

  void Act(SourceLocation PragmaLocation, PragmaMsStackAction Action,
           llvm::StringRef StackSlotLabel, ValueType Value) {
    if (Action == PSK_Reset) {
      CurrentValue = DefaultValue;
      CurrentPragmaLocation = PragmaLocation;
      return;
    }
    if (Action & PSK_Push)
      Stack.emplace_back(StackSlotLabel, CurrentValue, CurrentPragmaLocation,
                         PragmaLocation);
    else if (Action & PSK_Pop) {
      if (!StackSlotLabel.empty()) {
        // If we've got a label, try to find it and jump there.
        auto I = llvm::find_if(llvm::reverse(Stack), [&](const Slot &x) {
          return x.StackSlotLabel == StackSlotLabel;
        });
        // If we found the label so pop from there.
        if (I != Stack.rend()) {
          CurrentValue = I->Value;
          CurrentPragmaLocation = I->PragmaLocation;
          Stack.erase(std::prev(I.base()), Stack.end());
        }
      } else if (!Stack.empty()) {
        // We do not have a label, just pop the last entry.
        CurrentValue = Stack.back().Value;
        CurrentPragmaLocation = Stack.back().PragmaLocation;
        Stack.pop_back();
      }
    }
    if (Action & PSK_Set) {
      CurrentValue = Value;
      CurrentPragmaLocation = PragmaLocation;
    }
  }

  // MSVC seems to add artificial slots to #pragma stacks on entering a C++
  // method body to restore the stacks on exit, so it works like this:
  //
  //   struct S {
  //     #pragma <name>(push, InternalPragmaSlot, <current_pragma_value>)
  //     void Method {}
  //     #pragma <name>(pop, InternalPragmaSlot)
  //   };
  //
  // It works even with #pragma vtordisp, although MSVC doesn't support
  //   #pragma vtordisp(push [, id], n)
  // syntax.
  //
  // Push / pop a named sentinel slot.
  void SentinelAction(PragmaMsStackAction Action, StringRef Label) {
    assert((Action == PSK_Push || Action == PSK_Pop) &&((void)0)
           "Can only push / pop #pragma stack sentinels!")((void)0);
    Act(CurrentPragmaLocation, Action, Label, CurrentValue);
  }

  // Constructors.
  explicit PragmaStack(const ValueType &Default)
      : DefaultValue(Default), CurrentValue(Default) {}

  bool hasValue() const { return CurrentValue != DefaultValue; }

  SmallVector<Slot, 2> Stack;
  ValueType DefaultValue; // Value used for PSK_Reset action.
  ValueType CurrentValue;
  SourceLocation CurrentPragmaLocation;
};
// FIXME: We should serialize / deserialize these if they occur in a PCH (but
// we shouldn't do so if they're in a module).

/// Whether to insert vtordisps prior to virtual bases in the Microsoft
/// C++ ABI.  Possible values are 0, 1, and 2, which mean:
///
/// 0: Suppress all vtordisps
/// 1: Insert vtordisps in the presence of vbase overrides and non-trivial
///    structors
/// 2: Always insert vtordisps to support RTTI on partially constructed
///    objects
PragmaStack<MSVtorDispMode> VtorDispStack;
PragmaStack<AlignPackInfo> AlignPackStack;
// The current #pragma align/pack values and locations at each #include.
struct AlignPackIncludeState {
  AlignPackInfo CurrentValue;
  SourceLocation CurrentPragmaLocation;
  bool HasNonDefaultValue, ShouldWarnOnInclude;
};
SmallVector<AlignPackIncludeState, 8> AlignPackIncludeStack;
// Segment #pragmas.
PragmaStack<StringLiteral *> DataSegStack;
PragmaStack<StringLiteral *> BSSSegStack;
PragmaStack<StringLiteral *> ConstSegStack;
PragmaStack<StringLiteral *> CodeSegStack;

// This stack tracks the current state of Sema.CurFPFeatures.
PragmaStack<FPOptionsOverride> FpPragmaStack;
FPOptionsOverride CurFPFeatureOverrides() {
  FPOptionsOverride result;
  if (!FpPragmaStack.hasValue()) {
    result = FPOptionsOverride();
  } else {
    result = FpPragmaStack.CurrentValue;
  }
  return result;
}

// RAII object to push / pop sentinel slots for all MS #pragma stacks.
// Actions should be performed only if we enter / exit a C++ method body.
class PragmaStackSentinelRAII {
public:
  PragmaStackSentinelRAII(Sema &S, StringRef SlotLabel, bool ShouldAct);
  ~PragmaStackSentinelRAII();

private:
  Sema &S;
  StringRef SlotLabel;
  bool ShouldAct;
};

/// A mapping that describes the nullability we've seen in each header file.
FileNullabilityMap NullabilityMap;

/// Last section used with #pragma init_seg.
StringLiteral *CurInitSeg;
SourceLocation CurInitSegLoc;

/// VisContext - Manages the stack for \#pragma GCC visibility.
void *VisContext; // Really a "PragmaVisStack*"

/// This an attribute introduced by \#pragma clang attribute.
struct PragmaAttributeEntry {
  SourceLocation Loc;
  ParsedAttr *Attribute;
  SmallVector<attr::SubjectMatchRule, 4> MatchRules;
  bool IsUsed;
};

/// A push'd group of PragmaAttributeEntries.
struct PragmaAttributeGroup {
  /// The location of the push attribute.
  SourceLocation Loc;
  /// The namespace of this push group.
  const IdentifierInfo *Namespace;
  SmallVector<PragmaAttributeEntry, 2> Entries;
};

SmallVector<PragmaAttributeGroup, 2> PragmaAttributeStack;

/// The declaration that is currently receiving an attribute from the
/// #pragma attribute stack.
const Decl *PragmaAttributeCurrentTargetDecl;

/// This represents the last location of a "#pragma clang optimize off"
/// directive if such a directive has not been closed by an "on" yet. If
/// optimizations are currently "on", this is set to an invalid location.
SourceLocation OptimizeOffPragmaLocation;

/// Flag indicating if Sema is building a recovery call expression.
///
/// This flag is used to avoid building recovery call expressions
/// if Sema is already doing so, which would cause infinite recursions.
bool IsBuildingRecoveryCallExpr;

/// Used to control the generation of ExprWithCleanups.
CleanupInfo Cleanup;

/// ExprCleanupObjects - This is the stack of objects requiring
/// cleanup that are created by the current full expression.
SmallVector<ExprWithCleanups::CleanupObject, 8> ExprCleanupObjects;

/// Store a set of either DeclRefExprs or MemberExprs that contain a reference
/// to a variable (constant) that may or may not be odr-used in this Expr, and
/// we won't know until all lvalue-to-rvalue and discarded value conversions
/// have been applied to all subexpressions of the enclosing full expression.
/// This is cleared at the end of each full expression.
using MaybeODRUseExprSet = llvm::SetVector<Expr *, SmallVector<Expr *, 4>,
                                           llvm::SmallPtrSet<Expr *, 4>>;
MaybeODRUseExprSet MaybeODRUseExprs;

std::unique_ptr<sema::FunctionScopeInfo> CachedFunctionScope;

/// Stack containing information about each of the nested
/// function, block, and method scopes that are currently active.
SmallVector<sema::FunctionScopeInfo *, 4> FunctionScopes;

/// The index of the first FunctionScope that corresponds to the current
/// context.
unsigned FunctionScopesStart = 0;

ArrayRef<sema::FunctionScopeInfo*> getFunctionScopes() const {
  return llvm::makeArrayRef(FunctionScopes.begin() + FunctionScopesStart,
                            FunctionScopes.end());
}

/// Stack containing information needed when in C++2a an 'auto' is encountered
/// in a function declaration parameter type specifier in order to invent a
/// corresponding template parameter in the enclosing abbreviated function
/// template. This information is also present in LambdaScopeInfo, stored in
/// the FunctionScopes stack.
SmallVector<InventedTemplateParameterInfo, 4> InventedParameterInfos;

/// The index of the first InventedParameterInfo that refers to the current
/// context.
unsigned InventedParameterInfosStart = 0;

ArrayRef<InventedTemplateParameterInfo> getInventedParameterInfos() const {
  return llvm::makeArrayRef(InventedParameterInfos.begin() +
                                InventedParameterInfosStart,
                            InventedParameterInfos.end());
}

typedef LazyVector<TypedefNameDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadExtVectorDecls, 2, 2>
  ExtVectorDeclsType;

/// ExtVectorDecls - This is a list all the extended vector types. This allows
/// us to associate a raw vector type with one of the ext_vector type names.
/// This is only necessary for issuing pretty diagnostics.
ExtVectorDeclsType ExtVectorDecls;

/// FieldCollector - Collects CXXFieldDecls during parsing of C++ classes.
std::unique_ptr<CXXFieldCollector> FieldCollector;

typedef llvm::SmallSetVector<NamedDecl *, 16> NamedDeclSetType;

/// Set containing all declared private fields that are not used.
NamedDeclSetType UnusedPrivateFields;

/// Set containing all typedefs that are likely unused.
llvm::SmallSetVector<const TypedefNameDecl *, 4>
    UnusedLocalTypedefNameCandidates;

/// Delete-expressions to be analyzed at the end of translation unit
///
/// This list contains class members, and locations of delete-expressions
/// that could not be proven as to whether they mismatch with new-expression
/// used in initializer of the field.
typedef std::pair<SourceLocation, bool> DeleteExprLoc;
typedef llvm::SmallVector<DeleteExprLoc, 4> DeleteLocs;
llvm::MapVector<FieldDecl *, DeleteLocs> DeleteExprs;

typedef llvm::SmallPtrSet<const CXXRecordDecl*, 8> RecordDeclSetTy;

/// PureVirtualClassDiagSet - a set of class declarations which we have
/// emitted a list of pure virtual functions. Used to prevent emitting the
/// same list more than once.
std::unique_ptr<RecordDeclSetTy> PureVirtualClassDiagSet;

/// ParsingInitForAutoVars - a set of declarations with auto types for which
/// we are currently parsing the initializer.
llvm::SmallPtrSet<const Decl*, 4> ParsingInitForAutoVars;

/// Look for a locally scoped extern "C" declaration by the given name.
NamedDecl *findLocallyScopedExternCDecl(DeclarationName Name);

typedef LazyVector<VarDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadTentativeDefinitions, 2, 2>
  TentativeDefinitionsType;

/// All the tentative definitions encountered in the TU.
TentativeDefinitionsType TentativeDefinitions;

/// All the external declarations encoutered and used in the TU.
SmallVector<VarDecl *, 4> ExternalDeclarations;

typedef LazyVector<const DeclaratorDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadUnusedFileScopedDecls, 2, 2>
  UnusedFileScopedDeclsType;

/// The set of file scoped decls seen so far that have not been used
/// and must warn if not used. Only contains the first declaration.
UnusedFileScopedDeclsType UnusedFileScopedDecls;

typedef LazyVector<CXXConstructorDecl *, ExternalSemaSource,
                   &ExternalSemaSource::ReadDelegatingConstructors, 2, 2>
  DelegatingCtorDeclsType;

/// All the delegating constructors seen so far in the file, used for
/// cycle detection at the end of the TU.
DelegatingCtorDeclsType DelegatingCtorDecls;

/// All the overriding functions seen during a class definition
/// that had their exception spec checks delayed, plus the overridden
/// function.
SmallVector<std::pair<const CXXMethodDecl*, const CXXMethodDecl*>, 2>
  DelayedOverridingExceptionSpecChecks;

/// All the function redeclarations seen during a class definition that had
/// their exception spec checks delayed, plus the prior declaration they
/// should be checked against. Except during error recovery, the new decl
/// should always be a friend declaration, as that's the only valid way to
/// redeclare a special member before its class is complete.
SmallVector<std::pair<FunctionDecl*, FunctionDecl*>, 2>
  DelayedEquivalentExceptionSpecChecks;

typedef llvm::MapVector<const FunctionDecl *,
                        std::unique_ptr<LateParsedTemplate>>
    LateParsedTemplateMapT;
LateParsedTemplateMapT LateParsedTemplateMap;

/// Callback to the parser to parse templated functions when needed.
typedef void LateTemplateParserCB(void *P, LateParsedTemplate &LPT);
typedef void LateTemplateParserCleanupCB(void *P);
LateTemplateParserCB *LateTemplateParser;
LateTemplateParserCleanupCB *LateTemplateParserCleanup;
void *OpaqueParser;

void SetLateTemplateParser(LateTemplateParserCB *LTP,
                           LateTemplateParserCleanupCB *LTPCleanup,
                           void *P) {
  LateTemplateParser = LTP;
  LateTemplateParserCleanup = LTPCleanup;
  OpaqueParser = P;
}

// Does the work necessary to deal with a SYCL kernel lambda. At the moment,
// this just marks the list of lambdas required to name the kernel.
void AddSYCLKernelLambda(const FunctionDecl *FD);

class DelayedDiagnostics;

class DelayedDiagnosticsState {
  sema::DelayedDiagnosticPool *SavedPool;
  friend class Sema::DelayedDiagnostics;
};
typedef DelayedDiagnosticsState ParsingDeclState;
typedef DelayedDiagnosticsState ProcessingContextState;

/// A class which encapsulates the logic for delaying diagnostics
/// during parsing and other processing.
class DelayedDiagnostics {
  /// The current pool of diagnostics into which delayed
  /// diagnostics should go.
  sema::DelayedDiagnosticPool *CurPool;

public:
  DelayedDiagnostics() : CurPool(nullptr) {}

  /// Adds a delayed diagnostic.
  void add(const sema::DelayedDiagnostic &diag); // in DelayedDiagnostic.h

  /// Determines whether diagnostics should be delayed.
  bool shouldDelayDiagnostics() { return CurPool != nullptr; }

  /// Returns the current delayed-diagnostics pool.
  sema::DelayedDiagnosticPool *getCurrentPool() const {
    return CurPool;
  }

  /// Enter a new scope.  Access and deprecation diagnostics will be
  /// collected in this pool.
  DelayedDiagnosticsState push(sema::DelayedDiagnosticPool &pool) {
    DelayedDiagnosticsState state;
    state.SavedPool = CurPool;
    CurPool = &pool;
    return state;
  }

  /// Leave a delayed-diagnostic state that was previously pushed.
  /// Do not emit any of the diagnostics.  This is performed as part
  /// of the bookkeeping of popping a pool "properly".
  void popWithoutEmitting(DelayedDiagnosticsState state) {
    CurPool = state.SavedPool;
  }

  /// Enter a new scope where access and deprecation diagnostics are
  /// not delayed.
  DelayedDiagnosticsState pushUndelayed() {
    DelayedDiagnosticsState state;
    state.SavedPool = CurPool;
    CurPool = nullptr;
    return state;
  }

  /// Undo a previous pushUndelayed().
  void popUndelayed(DelayedDiagnosticsState state) {
    assert(CurPool == nullptr)((void)0);
    CurPool = state.SavedPool;
  }
} DelayedDiagnostics;

/// A RAII object to temporarily push a declaration context.
class ContextRAII {
private:
  Sema &S;
  DeclContext *SavedContext;
  ProcessingContextState SavedContextState;
  QualType SavedCXXThisTypeOverride;
  unsigned SavedFunctionScopesStart;
  unsigned SavedInventedParameterInfosStart;

public:
  ContextRAII(Sema &S, DeclContext *ContextToPush, bool NewThisContext = true)
    : S(S), SavedContext(S.CurContext),
      SavedContextState(S.DelayedDiagnostics.pushUndelayed()),
      SavedCXXThisTypeOverride(S.CXXThisTypeOverride),
      SavedFunctionScopesStart(S.FunctionScopesStart),
      SavedInventedParameterInfosStart(S.InventedParameterInfosStart)
  {
    assert(ContextToPush && "pushing null context")((void)0);
    S.CurContext = ContextToPush;
    if (NewThisContext)
      S.CXXThisTypeOverride = QualType();
    // Any saved FunctionScopes do not refer to this context.
    S.FunctionScopesStart = S.FunctionScopes.size();
    S.InventedParameterInfosStart = S.InventedParameterInfos.size();
  }

  void pop() {
    if (!SavedContext) return;
    S.CurContext = SavedContext;
    S.DelayedDiagnostics.popUndelayed(SavedContextState);
    S.CXXThisTypeOverride = SavedCXXThisTypeOverride;
    S.FunctionScopesStart = SavedFunctionScopesStart;
    S.InventedParameterInfosStart = SavedInventedParameterInfosStart;
    SavedContext = nullptr;
  }

  ~ContextRAII() {
    pop();
  }
};

/// Whether the AST is currently being rebuilt to correct immediate
/// invocations. Immediate invocation candidates and references to consteval
/// functions aren't tracked when this is set.
bool RebuildingImmediateInvocation = false;

/// Used to change context to isConstantEvaluated without pushing a heavy
/// ExpressionEvaluationContextRecord object.
bool isConstantEvaluatedOverride;

bool isConstantEvaluated() {
  return ExprEvalContexts.back().isConstantEvaluated() ||
         isConstantEvaluatedOverride;
}

/// RAII object to handle the state changes required to synthesize
/// a function body.
class SynthesizedFunctionScope {
  Sema &S;
  Sema::ContextRAII SavedContext;
  bool PushedCodeSynthesisContext = false;

public:
  SynthesizedFunctionScope(Sema &S, DeclContext *DC)
      : S(S), SavedContext(S, DC) {
    S.PushFunctionScope();
    S.PushExpressionEvaluationContext(
        Sema::ExpressionEvaluationContext::PotentiallyEvaluated);
    if (auto *FD = dyn_cast<FunctionDecl>(DC))
      FD->setWillHaveBody(true);
    else
      assert(isa<ObjCMethodDecl>(DC))((void)0);
  }

  void addContextNote(SourceLocation UseLoc) {
    assert(!PushedCodeSynthesisContext)((void)0);

    Sema::CodeSynthesisContext Ctx;
    Ctx.Kind = Sema::CodeSynthesisContext::DefiningSynthesizedFunction;
    Ctx.PointOfInstantiation = UseLoc;
    Ctx.Entity = cast<Decl>(S.CurContext);
    S.pushCodeSynthesisContext(Ctx);

    PushedCodeSynthesisContext = true;
  }

  ~SynthesizedFunctionScope() {
    if (PushedCodeSynthesisContext)
      S.popCodeSynthesisContext();
    if (auto *FD = dyn_cast<FunctionDecl>(S.CurContext))
      FD->setWillHaveBody(false);
    S.PopExpressionEvaluationContext();
    S.PopFunctionScopeInfo();
  }
};

/// WeakUndeclaredIdentifiers - Identifiers contained in
/// \#pragma weak before declared. rare. may alias another
/// identifier, declared or undeclared
llvm::MapVector<IdentifierInfo *, WeakInfo> WeakUndeclaredIdentifiers;

/// ExtnameUndeclaredIdentifiers - Identifiers contained in
/// \#pragma redefine_extname before declared.  Used in Solaris system headers
/// to define functions that occur in multiple standards to call the version
/// in the currently selected standard.
llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*> ExtnameUndeclaredIdentifiers;


/// Load weak undeclared identifiers from the external source.
void LoadExternalWeakUndeclaredIdentifiers();

/// WeakTopLevelDecl - Translation-unit scoped declarations generated by
/// \#pragma weak during processing of other Decls.
/// I couldn't figure out a clean way to generate these in-line, so
/// we store them here and handle separately -- which is a hack.
/// It would be best to refactor this.
SmallVector<Decl*,2> WeakTopLevelDecl;

IdentifierResolver IdResolver;

/// Translation Unit Scope - useful to Objective-C actions that need
/// to lookup file scope declarations in the "ordinary" C decl namespace.
/// For example, user-defined classes, built-in "id" type, etc.
Scope *TUScope;

/// The C++ "std" namespace, where the standard library resides.
LazyDeclPtr StdNamespace;

/// The C++ "std::bad_alloc" class, which is defined by the C++
/// standard library.
LazyDeclPtr StdBadAlloc;

/// The C++ "std::align_val_t" enum class, which is defined by the C++
/// standard library.
LazyDeclPtr StdAlignValT;

/// The C++ "std::experimental" namespace, where the experimental parts
/// of the standard library resides.
NamespaceDecl *StdExperimentalNamespaceCache;

/// The C++ "std::initializer_list" template, which is defined in
/// \<initializer_list>.
ClassTemplateDecl *StdInitializerList;

/// The C++ "std::coroutine_traits" template, which is defined in
/// \<coroutine_traits>
ClassTemplateDecl *StdCoroutineTraitsCache;

/// The C++ "type_info" declaration, which is defined in \<typeinfo>.
RecordDecl *CXXTypeInfoDecl;

/// The MSVC "_GUID" struct, which is defined in MSVC header files.
RecordDecl *MSVCGuidDecl;

/// Caches identifiers/selectors for NSFoundation APIs.
std::unique_ptr<NSAPI> NSAPIObj;

/// The declaration of the Objective-C NSNumber class.
ObjCInterfaceDecl *NSNumberDecl;

/// The declaration of the Objective-C NSValue class.
ObjCInterfaceDecl *NSValueDecl;

/// Pointer to NSNumber type (NSNumber *).
QualType NSNumberPointer;

/// Pointer to NSValue type (NSValue *).
QualType NSValuePointer;

/// The Objective-C NSNumber methods used to create NSNumber literals.
ObjCMethodDecl *NSNumberLiteralMethods[NSAPI::NumNSNumberLiteralMethods];

/// The declaration of the Objective-C NSString class.
ObjCInterfaceDecl *NSStringDecl;

/// Pointer to NSString type (NSString *).
QualType NSStringPointer;

/// The declaration of the stringWithUTF8String: method.
ObjCMethodDecl *StringWithUTF8StringMethod;

/// The declaration of the valueWithBytes:objCType: method.
ObjCMethodDecl *ValueWithBytesObjCTypeMethod;

/// The declaration of the Objective-C NSArray class.
ObjCInterfaceDecl *NSArrayDecl;

/// The declaration of the arrayWithObjects:count: method.
ObjCMethodDecl *ArrayWithObjectsMethod;

/// The declaration of the Objective-C NSDictionary class.
ObjCInterfaceDecl *NSDictionaryDecl;

/// The declaration of the dictionaryWithObjects:forKeys:count: method.
ObjCMethodDecl *DictionaryWithObjectsMethod;

/// id<NSCopying> type.
QualType QIDNSCopying;

/// will hold 'respondsToSelector:'
Selector RespondsToSelectorSel;

/// A flag to remember whether the implicit forms of operator new and delete
/// have been declared.
bool GlobalNewDeleteDeclared;

/// Describes how the expressions currently being parsed are
/// evaluated at run-time, if at all.
enum class ExpressionEvaluationContext {
  /// The current expression and its subexpressions occur within an
  /// unevaluated operand (C++11 [expr]p7), such as the subexpression of
  /// \c sizeof, where the type of the expression may be significant but
  /// no code will be generated to evaluate the value of the expression at
  /// run time.
  Unevaluated,

  /// The current expression occurs within a braced-init-list within
  /// an unevaluated operand. This is mostly like a regular unevaluated
  /// context, except that we still instantiate constexpr functions that are
  /// referenced here so that we can perform narrowing checks correctly.
  UnevaluatedList,

  /// The current expression occurs within a discarded statement.
  /// This behaves largely similarly to an unevaluated operand in preventing
  /// definitions from being required, but not in other ways.
  DiscardedStatement,

  /// The current expression occurs within an unevaluated
  /// operand that unconditionally permits abstract references to
  /// fields, such as a SIZE operator in MS-style inline assembly.
  UnevaluatedAbstract,

  /// The current context is "potentially evaluated" in C++11 terms,
  /// but the expression is evaluated at compile-time (like the values of
  /// cases in a switch statement).
  ConstantEvaluated,

  /// The current expression is potentially evaluated at run time,
  /// which means that code may be generated to evaluate the value of the
  /// expression at run time.
  PotentiallyEvaluated,

  /// The current expression is potentially evaluated, but any
  /// declarations referenced inside that expression are only used if
  /// in fact the current expression is used.
  ///
  /// This value is used when parsing default function arguments, for which
  /// we would like to provide diagnostics (e.g., passing non-POD arguments
  /// through varargs) but do not want to mark declarations as "referenced"
  /// until the default argument is used.
  PotentiallyEvaluatedIfUsed
};

using ImmediateInvocationCandidate = llvm::PointerIntPair<ConstantExpr *, 1>;

/// Data structure used to record current or nested
/// expression evaluation contexts.
struct ExpressionEvaluationContextRecord {
  /// The expression evaluation context.
  ExpressionEvaluationContext Context;

  /// Whether the enclosing context needed a cleanup.
  CleanupInfo ParentCleanup;

  /// The number of active cleanup objects when we entered
  /// this expression evaluation context.
  unsigned NumCleanupObjects;

  /// The number of typos encountered during this expression evaluation
  /// context (i.e. the number of TypoExprs created).
  unsigned NumTypos;

  MaybeODRUseExprSet SavedMaybeODRUseExprs;

  /// The lambdas that are present within this context, if it
  /// is indeed an unevaluated context.
  SmallVector<LambdaExpr *, 2> Lambdas;

  /// The declaration that provides context for lambda expressions
  /// and block literals if the normal declaration context does not
  /// suffice, e.g., in a default function argument.
  Decl *ManglingContextDecl;

  /// If we are processing a decltype type, a set of call expressions
  /// for which we have deferred checking the completeness of the return type.
  SmallVector<CallExpr *, 8> DelayedDecltypeCalls;

  /// If we are processing a decltype type, a set of temporary binding
  /// expressions for which we have deferred checking the destructor.
  SmallVector<CXXBindTemporaryExpr *, 8> DelayedDecltypeBinds;

  llvm::SmallPtrSet<const Expr *, 8> PossibleDerefs;

  /// Expressions appearing as the LHS of a volatile assignment in this
  /// context. We produce a warning for these when popping the context if
  /// they are not discarded-value expressions nor unevaluated operands.
  SmallVector<Expr*, 2> VolatileAssignmentLHSs;

  /// Set of candidates for starting an immediate invocation.
  llvm::SmallVector<ImmediateInvocationCandidate, 4> ImmediateInvocationCandidates;

  /// Set of DeclRefExprs referencing a consteval function when used in a
  /// context not already known to be immediately invoked.
  llvm::SmallPtrSet<DeclRefExpr *, 4> ReferenceToConsteval;

  /// \brief Describes whether we are in an expression constext which we have
  /// to handle differently.
  enum ExpressionKind {
    EK_Decltype, EK_TemplateArgument, EK_Other
  } ExprContext;

  ExpressionEvaluationContextRecord(ExpressionEvaluationContext Context,
                                    unsigned NumCleanupObjects,
                                    CleanupInfo ParentCleanup,
                                    Decl *ManglingContextDecl,
                                    ExpressionKind ExprContext)
      : Context(Context), ParentCleanup(ParentCleanup),
        NumCleanupObjects(NumCleanupObjects), NumTypos(0),
        ManglingContextDecl(ManglingContextDecl), ExprContext(ExprContext) {}

  bool isUnevaluated() const {
    return Context == ExpressionEvaluationContext::Unevaluated ||
7
←
Assuming field 'Context' is not equal to Unevaluated→
10
←
Returning zero, which participates in a condition later→
           Context == ExpressionEvaluationContext::UnevaluatedAbstract ||
8
←
Assuming field 'Context' is not equal to UnevaluatedAbstract→
           Context == ExpressionEvaluationContext::UnevaluatedList;
9
←
Assuming field 'Context' is not equal to UnevaluatedList→
  }
  bool isConstantEvaluated() const {
    return Context == ExpressionEvaluationContext::ConstantEvaluated;
  }
};

/// A stack of expression evaluation contexts.
SmallVector<ExpressionEvaluationContextRecord, 8> ExprEvalContexts;

/// Emit a warning for all pending noderef expressions that we recorded.
void WarnOnPendingNoDerefs(ExpressionEvaluationContextRecord &Rec);

/// Compute the mangling number context for a lambda expression or
/// block literal. Also return the extra mangling decl if any.
///
/// \param DC - The DeclContext containing the lambda expression or
/// block literal.
std::tuple<MangleNumberingContext *, Decl *>
getCurrentMangleNumberContext(const DeclContext *DC);


/// SpecialMemberOverloadResult - The overloading result for a special member
/// function.
///
/// This is basically a wrapper around PointerIntPair. The lowest bits of the
/// integer are used to determine whether overload resolution succeeded.
class SpecialMemberOverloadResult {
public:
  enum Kind {
    NoMemberOrDeleted,
    Ambiguous,
    Success
  };

private:
  llvm::PointerIntPair<CXXMethodDecl*, 2> Pair;

public:
  SpecialMemberOverloadResult() : Pair() {}
  SpecialMemberOverloadResult(CXXMethodDecl *MD)
      : Pair(MD, MD->isDeleted() ? NoMemberOrDeleted : Success) {}

  CXXMethodDecl *getMethod() const { return Pair.getPointer(); }
  void setMethod(CXXMethodDecl *MD) { Pair.setPointer(MD); }

  Kind getKind() const { return static_cast<Kind>(Pair.getInt()); }
  void setKind(Kind K) { Pair.setInt(K); }
};

class SpecialMemberOverloadResultEntry
    : public llvm::FastFoldingSetNode,
      public SpecialMemberOverloadResult {
public:
  SpecialMemberOverloadResultEntry(const llvm::FoldingSetNodeID &ID)
    : FastFoldingSetNode(ID)
  {}
};

/// A cache of special member function overload resolution results
/// for C++ records.
llvm::FoldingSet<SpecialMemberOverloadResultEntry> SpecialMemberCache;

/// A cache of the flags available in enumerations with the flag_bits
/// attribute.
mutable llvm::DenseMap<const EnumDecl*, llvm::APInt> FlagBitsCache;

/// The kind of translation unit we are processing.
///
/// When we're processing a complete translation unit, Sema will perform
/// end-of-translation-unit semantic tasks (such as creating
/// initializers for tentative definitions in C) once parsing has
/// completed. Modules and precompiled headers perform different kinds of
/// checks.
const TranslationUnitKind TUKind;

llvm::BumpPtrAllocator BumpAlloc;

/// The number of SFINAE diagnostics that have been trapped.
unsigned NumSFINAEErrors;

typedef llvm::DenseMap<ParmVarDecl *, llvm::TinyPtrVector<ParmVarDecl *>>
  UnparsedDefaultArgInstantiationsMap;

/// A mapping from parameters with unparsed default arguments to the
/// set of instantiations of each parameter.
///
/// This mapping is a temporary data structure used when parsing
/// nested class templates or nested classes of class templates,
/// where we might end up instantiating an inner class before the
/// default arguments of its methods have been parsed.
UnparsedDefaultArgInstantiationsMap UnparsedDefaultArgInstantiations;

// Contains the locations of the beginning of unparsed default
// argument locations.
llvm::DenseMap<ParmVarDecl *, SourceLocation> UnparsedDefaultArgLocs;

/// UndefinedInternals - all the used, undefined objects which require a
/// definition in this translation unit.
llvm::MapVector<NamedDecl *, SourceLocation> UndefinedButUsed;

/// Determine if VD, which must be a variable or function, is an external
/// symbol that nonetheless can't be referenced from outside this translation
/// unit because its type has no linkage and it's not extern "C".
bool isExternalWithNoLinkageType(ValueDecl *VD);

/// Obtain a sorted list of functions that are undefined but ODR-used.
void getUndefinedButUsed(
    SmallVectorImpl<std::pair<NamedDecl *, SourceLocation> > &Undefined);

/// Retrieves list of suspicious delete-expressions that will be checked at
/// the end of translation unit.
const llvm::MapVector<FieldDecl *, DeleteLocs> &
getMismatchingDeleteExpressions() const;

typedef std::pair<ObjCMethodList, ObjCMethodList> GlobalMethods;
typedef llvm::DenseMap<Selector, GlobalMethods> GlobalMethodPool;

/// Method Pool - allows efficient lookup when typechecking messages to "id".
/// We need to maintain a list, since selectors can have differing signatures
/// across classes. In Cocoa, this happens to be extremely uncommon (only 1%
/// of selectors are "overloaded").
/// At the head of the list it is recorded whether there were 0, 1, or >= 2
/// methods inside categories with a particular selector.
GlobalMethodPool MethodPool;

/// Method selectors used in a \@selector expression. Used for implementation
/// of -Wselector.
llvm::MapVector<Selector, SourceLocation> ReferencedSelectors;

/// List of SourceLocations where 'self' is implicitly retained inside a
/// block.
llvm::SmallVector<std::pair<SourceLocation, const BlockDecl *>, 1>
    ImplicitlyRetainedSelfLocs;

/// Kinds of C++ special members.
enum CXXSpecialMember {
  CXXDefaultConstructor,
  CXXCopyConstructor,
  CXXMoveConstructor,
  CXXCopyAssignment,
  CXXMoveAssignment,
  CXXDestructor,
  CXXInvalid
};

typedef llvm::PointerIntPair<CXXRecordDecl *, 3, CXXSpecialMember>
    SpecialMemberDecl;

/// The C++ special members which we are currently in the process of
/// declaring. If this process recursively triggers the declaration of the
/// same special member, we should act as if it is not yet declared.
llvm::SmallPtrSet<SpecialMemberDecl, 4> SpecialMembersBeingDeclared;

/// Kinds of defaulted comparison operator functions.
enum class DefaultedComparisonKind : unsigned char {
  /// This is not a defaultable comparison operator.
  None,
  /// This is an operator== that should be implemented as a series of
  /// subobject comparisons.
  Equal,
  /// This is an operator<=> that should be implemented as a series of
  /// subobject comparisons.
  ThreeWay,
  /// This is an operator!= that should be implemented as a rewrite in terms
  /// of a == comparison.
  NotEqual,
  /// This is an <, <=, >, or >= that should be implemented as a rewrite in
  /// terms of a <=> comparison.
  Relational,
};

/// The function definitions which were renamed as part of typo-correction
/// to match their respective declarations. We want to keep track of them
/// to ensure that we don't emit a "redefinition" error if we encounter a
/// correctly named definition after the renamed definition.
llvm::SmallPtrSet<const NamedDecl *, 4> TypoCorrectedFunctionDefinitions;

/// Stack of types that correspond to the parameter entities that are
/// currently being copy-initialized. Can be empty.
llvm::SmallVector<QualType, 4> CurrentParameterCopyTypes;

void ReadMethodPool(Selector Sel);
void updateOutOfDateSelector(Selector Sel);

/// Private Helper predicate to check for 'self'.
bool isSelfExpr(Expr *RExpr);
bool isSelfExpr(Expr *RExpr, const ObjCMethodDecl *Method);

/// Cause the active diagnostic on the DiagosticsEngine to be
/// emitted. This is closely coupled to the SemaDiagnosticBuilder class and
/// should not be used elsewhere.
void EmitCurrentDiagnostic(unsigned DiagID);

/// Records and restores the CurFPFeatures state on entry/exit of compound
/// statements.
class FPFeaturesStateRAII {
public:
  FPFeaturesStateRAII(Sema &S) : S(S), OldFPFeaturesState(S.CurFPFeatures) {
    OldOverrides = S.FpPragmaStack.CurrentValue;
  }
  ~FPFeaturesStateRAII() {
    S.CurFPFeatures = OldFPFeaturesState;
    S.FpPragmaStack.CurrentValue = OldOverrides;
  }
  FPOptionsOverride getOverrides() { return OldOverrides; }

private:
  Sema& S;
  FPOptions OldFPFeaturesState;
  FPOptionsOverride OldOverrides;
};

void addImplicitTypedef(StringRef Name, QualType T);

bool WarnedStackExhausted = false;

/// Increment when we find a reference; decrement when we find an ignored
/// assignment.  Ultimately the value is 0 if every reference is an ignored
/// assignment.
llvm::DenseMap<const VarDecl *, int> RefsMinusAssignments;

Optional<std::unique_ptr<DarwinSDKInfo>> CachedDarwinSDKInfo;

1531public:
Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
     TranslationUnitKind TUKind = TU_Complete,
     CodeCompleteConsumer *CompletionConsumer = nullptr);
~Sema();

/// Perform initialization that occurs after the parser has been
/// initialized but before it parses anything.
void Initialize();

/// This virtual key function only exists to limit the emission of debug info
/// describing the Sema class. GCC and Clang only emit debug info for a class
/// with a vtable when the vtable is emitted. Sema is final and not
/// polymorphic, but the debug info size savings are so significant that it is
/// worth adding a vtable just to take advantage of this optimization.
virtual void anchor();

const LangOptions &getLangOpts() const { return LangOpts; }
OpenCLOptions &getOpenCLOptions() { return OpenCLFeatures; }
FPOptions     &getCurFPFeatures() { return CurFPFeatures; }

DiagnosticsEngine &getDiagnostics() const { return Diags; }
SourceManager &getSourceManager() const { return SourceMgr; }
Preprocessor &getPreprocessor() const { return PP; }
ASTContext &getASTContext() const { return Context; }
ASTConsumer &getASTConsumer() const { return Consumer; }
ASTMutationListener *getASTMutationListener() const;
ExternalSemaSource* getExternalSource() const { return ExternalSource; }
DarwinSDKInfo *getDarwinSDKInfoForAvailabilityChecking(SourceLocation Loc,
                                                       StringRef Platform);

///Registers an external source. If an external source already exists,
/// creates a multiplex external source and appends to it.
///
///\param[in] E - A non-null external sema source.
///
void addExternalSource(ExternalSemaSource *E);

void PrintStats() const;

/// Warn that the stack is nearly exhausted.
void warnStackExhausted(SourceLocation Loc);

/// Run some code with "sufficient" stack space. (Currently, at least 256K is
/// guaranteed). Produces a warning if we're low on stack space and allocates
/// more in that case. Use this in code that may recurse deeply (for example,
/// in template instantiation) to avoid stack overflow.
void runWithSufficientStackSpace(SourceLocation Loc,
                                 llvm::function_ref<void()> Fn);

/// Helper class that creates diagnostics with optional
/// template instantiation stacks.
///
/// This class provides a wrapper around the basic DiagnosticBuilder
/// class that emits diagnostics. ImmediateDiagBuilder is
/// responsible for emitting the diagnostic (as DiagnosticBuilder
/// does) and, if the diagnostic comes from inside a template
/// instantiation, printing the template instantiation stack as
/// well.
class ImmediateDiagBuilder : public DiagnosticBuilder {
  Sema &SemaRef;
  unsigned DiagID;

public:
  ImmediateDiagBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
      : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
  ImmediateDiagBuilder(DiagnosticBuilder &&DB, Sema &SemaRef, unsigned DiagID)
      : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}

  // This is a cunning lie. DiagnosticBuilder actually performs move
  // construction in its copy constructor (but due to varied uses, it's not
  // possible to conveniently express this as actual move construction). So
  // the default copy ctor here is fine, because the base class disables the
  // source anyway, so the user-defined ~ImmediateDiagBuilder is a safe no-op
  // in that case anwyay.
  ImmediateDiagBuilder(const ImmediateDiagBuilder &) = default;

  ~ImmediateDiagBuilder() {
    // If we aren't active, there is nothing to do.
    if (!isActive()) return;

    // Otherwise, we need to emit the diagnostic. First clear the diagnostic
    // builder itself so it won't emit the diagnostic in its own destructor.
    //
    // This seems wasteful, in that as written the DiagnosticBuilder dtor will
    // do its own needless checks to see if the diagnostic needs to be
    // emitted. However, because we take care to ensure that the builder
    // objects never escape, a sufficiently smart compiler will be able to
    // eliminate that code.
    Clear();

    // Dispatch to Sema to emit the diagnostic.
    SemaRef.EmitCurrentDiagnostic(DiagID);
  }

  /// Teach operator<< to produce an object of the correct type.
  template <typename T>
  friend const ImmediateDiagBuilder &
  operator<<(const ImmediateDiagBuilder &Diag, const T &Value) {
    const DiagnosticBuilder &BaseDiag = Diag;
    BaseDiag << Value;
    return Diag;
  }

  // It is necessary to limit this to rvalue reference to avoid calling this
  // function with a bitfield lvalue argument since non-const reference to
  // bitfield is not allowed.
  template <typename T, typename = typename std::enable_if<
                            !std::is_lvalue_reference<T>::value>::type>
  const ImmediateDiagBuilder &operator<<(T &&V) const {
    const DiagnosticBuilder &BaseDiag = *this;
    BaseDiag << std::move(V);
    return *this;
  }
};

/// A generic diagnostic builder for errors which may or may not be deferred.
///
/// In CUDA, there exist constructs (e.g. variable-length arrays, try/catch)
/// which are not allowed to appear inside __device__ functions and are
/// allowed to appear in __host__ __device__ functions only if the host+device
/// function is never codegen'ed.
///
/// To handle this, we use the notion of "deferred diagnostics", where we
/// attach a diagnostic to a FunctionDecl that's emitted iff it's codegen'ed.
///
/// This class lets you emit either a regular diagnostic, a deferred
/// diagnostic, or no diagnostic at all, according to an argument you pass to
/// its constructor, thus simplifying the process of creating these "maybe
/// deferred" diagnostics.
class SemaDiagnosticBuilder {
public:
  enum Kind {
    /// Emit no diagnostics.
    K_Nop,
    /// Emit the diagnostic immediately (i.e., behave like Sema::Diag()).
    K_Immediate,
    /// Emit the diagnostic immediately, and, if it's a warning or error, also
    /// emit a call stack showing how this function can be reached by an a
    /// priori known-emitted function.
    K_ImmediateWithCallStack,
    /// Create a deferred diagnostic, which is emitted only if the function
    /// it's attached to is codegen'ed.  Also emit a call stack as with
    /// K_ImmediateWithCallStack.
    K_Deferred
  };

  SemaDiagnosticBuilder(Kind K, SourceLocation Loc, unsigned DiagID,
                        FunctionDecl *Fn, Sema &S);
  SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D);
  SemaDiagnosticBuilder(const SemaDiagnosticBuilder &) = default;
  ~SemaDiagnosticBuilder();

  bool isImmediate() const { return ImmediateDiag.hasValue(); }

  /// Convertible to bool: True if we immediately emitted an error, false if
  /// we didn't emit an error or we created a deferred error.
  ///
  /// Example usage:
  ///
  ///   if (SemaDiagnosticBuilder(...) << foo << bar)
  ///     return ExprError();
  ///
  /// But see CUDADiagIfDeviceCode() and CUDADiagIfHostCode() -- you probably
  /// want to use these instead of creating a SemaDiagnosticBuilder yourself.
  operator bool() const { return isImmediate(); }

  template <typename T>
  friend const SemaDiagnosticBuilder &
  operator<<(const SemaDiagnosticBuilder &Diag, const T &Value) {
    if (Diag.ImmediateDiag.hasValue())
      *Diag.ImmediateDiag << Value;
    else if (Diag.PartialDiagId.hasValue())
      Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second
          << Value;
    return Diag;
  }

  // It is necessary to limit this to rvalue reference to avoid calling this
  // function with a bitfield lvalue argument since non-const reference to
  // bitfield is not allowed.
  template <typename T, typename = typename std::enable_if<
                            !std::is_lvalue_reference<T>::value>::type>
  const SemaDiagnosticBuilder &operator<<(T &&V) const {
    if (ImmediateDiag.hasValue())
      *ImmediateDiag << std::move(V);
    else if (PartialDiagId.hasValue())
      S.DeviceDeferredDiags[Fn][*PartialDiagId].second << std::move(V);
    return *this;
  }

  friend const SemaDiagnosticBuilder &
  operator<<(const SemaDiagnosticBuilder &Diag, const PartialDiagnostic &PD) {
    if (Diag.ImmediateDiag.hasValue())
      PD.Emit(*Diag.ImmediateDiag);
    else if (Diag.PartialDiagId.hasValue())
      Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second = PD;
    return Diag;
  }

  void AddFixItHint(const FixItHint &Hint) const {
    if (ImmediateDiag.hasValue())
      ImmediateDiag->AddFixItHint(Hint);
    else if (PartialDiagId.hasValue())
      S.DeviceDeferredDiags[Fn][*PartialDiagId].second.AddFixItHint(Hint);
  }

  friend ExprResult ExprError(const SemaDiagnosticBuilder &) {
    return ExprError();
  }
  friend StmtResult StmtError(const SemaDiagnosticBuilder &) {
    return StmtError();
  }
  operator ExprResult() const { return ExprError(); }
  operator StmtResult() const { return StmtError(); }
  operator TypeResult() const { return TypeError(); }
  operator DeclResult() const { return DeclResult(true); }
  operator MemInitResult() const { return MemInitResult(true); }

private:
  Sema &S;
  SourceLocation Loc;
  unsigned DiagID;
  FunctionDecl *Fn;
  bool ShowCallStack;

  // Invariant: At most one of these Optionals has a value.
  // FIXME: Switch these to a Variant once that exists.
  llvm::Optional<ImmediateDiagBuilder> ImmediateDiag;
  llvm::Optional<unsigned> PartialDiagId;
};

/// Is the last error level diagnostic immediate. This is used to determined
/// whether the next info diagnostic should be immediate.
bool IsLastErrorImmediate = true;

/// Emit a diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID,
                           bool DeferHint = false);

/// Emit a partial diagnostic.
SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic &PD,
                           bool DeferHint = false);

/// Build a partial diagnostic.
PartialDiagnostic PDiag(unsigned DiagID = 0); // in SemaInternal.h

/// Whether deferrable diagnostics should be deferred.
bool DeferDiags = false;

/// RAII class to control scope of DeferDiags.
class DeferDiagsRAII {
  Sema &S;
  bool SavedDeferDiags = false;

public:
  DeferDiagsRAII(Sema &S, bool DeferDiags)
      : S(S), SavedDeferDiags(S.DeferDiags) {
    S.DeferDiags = DeferDiags;
  }
  ~DeferDiagsRAII() { S.DeferDiags = SavedDeferDiags; }
};

/// Whether uncompilable error has occurred. This includes error happens
/// in deferred diagnostics.
bool hasUncompilableErrorOccurred() const;

bool findMacroSpelling(SourceLocation &loc, StringRef name);

/// Get a string to suggest for zero-initialization of a type.
std::string
getFixItZeroInitializerForType(QualType T, SourceLocation Loc) const;
std::string getFixItZeroLiteralForType(QualType T, SourceLocation Loc) const;

/// Calls \c Lexer::getLocForEndOfToken()
SourceLocation getLocForEndOfToken(SourceLocation Loc, unsigned Offset = 0);

/// Retrieve the module loader associated with the preprocessor.
ModuleLoader &getModuleLoader() const;

/// Invent a new identifier for parameters of abbreviated templates.
IdentifierInfo *
InventAbbreviatedTemplateParameterTypeName(IdentifierInfo *ParamName,
                                           unsigned Index);

void emitAndClearUnusedLocalTypedefWarnings();

private:
  /// Function or variable declarations to be checked for whether the deferred
  /// diagnostics should be emitted.
  llvm::SmallSetVector<Decl *, 4> DeclsToCheckForDeferredDiags;

public:
// Emit all deferred diagnostics.
void emitDeferredDiags();

enum TUFragmentKind {
  /// The global module fragment, between 'module;' and a module-declaration.
  Global,
  /// A normal translation unit fragment. For a non-module unit, this is the
  /// entire translation unit. Otherwise, it runs from the module-declaration
  /// to the private-module-fragment (if any) or the end of the TU (if not).
  Normal,
  /// The private module fragment, between 'module :private;' and the end of
  /// the translation unit.
  Private
};

void ActOnStartOfTranslationUnit();
void ActOnEndOfTranslationUnit();
void ActOnEndOfTranslationUnitFragment(TUFragmentKind Kind);

void CheckDelegatingCtorCycles();

Scope *getScopeForContext(DeclContext *Ctx);

void PushFunctionScope();
void PushBlockScope(Scope *BlockScope, BlockDecl *Block);
sema::LambdaScopeInfo *PushLambdaScope();

/// This is used to inform Sema what the current TemplateParameterDepth
/// is during Parsing.  Currently it is used to pass on the depth
/// when parsing generic lambda 'auto' parameters.
void RecordParsingTemplateParameterDepth(unsigned Depth);

void PushCapturedRegionScope(Scope *RegionScope, CapturedDecl *CD,
                             RecordDecl *RD, CapturedRegionKind K,
                             unsigned OpenMPCaptureLevel = 0);

/// Custom deleter to allow FunctionScopeInfos to be kept alive for a short
/// time after they've been popped.
class PoppedFunctionScopeDeleter {
  Sema *Self;

public:
  explicit PoppedFunctionScopeDeleter(Sema *Self) : Self(Self) {}
  void operator()(sema::FunctionScopeInfo *Scope) const;
};

using PoppedFunctionScopePtr =
    std::unique_ptr<sema::FunctionScopeInfo, PoppedFunctionScopeDeleter>;

PoppedFunctionScopePtr
PopFunctionScopeInfo(const sema::AnalysisBasedWarnings::Policy *WP = nullptr,
                     const Decl *D = nullptr,
                     QualType BlockType = QualType());

sema::FunctionScopeInfo *getCurFunction() const {
  return FunctionScopes.empty() ? nullptr : FunctionScopes.back();
}

sema::FunctionScopeInfo *getEnclosingFunction() const;

void setFunctionHasBranchIntoScope();
void setFunctionHasBranchProtectedScope();
void setFunctionHasIndirectGoto();
void setFunctionHasMustTail();

void PushCompoundScope(bool IsStmtExpr);
void PopCompoundScope();

sema::CompoundScopeInfo &getCurCompoundScope() const;

bool hasAnyUnrecoverableErrorsInThisFunction() const;

/// Retrieve the current block, if any.
sema::BlockScopeInfo *getCurBlock();

/// Get the innermost lambda enclosing the current location, if any. This
/// looks through intervening non-lambda scopes such as local functions and
/// blocks.
sema::LambdaScopeInfo *getEnclosingLambda() const;

/// Retrieve the current lambda scope info, if any.
/// \param IgnoreNonLambdaCapturingScope true if should find the top-most
/// lambda scope info ignoring all inner capturing scopes that are not
/// lambda scopes.
sema::LambdaScopeInfo *
getCurLambda(bool IgnoreNonLambdaCapturingScope = false);

/// Retrieve the current generic lambda info, if any.
sema::LambdaScopeInfo *getCurGenericLambda();

/// Retrieve the current captured region, if any.
sema::CapturedRegionScopeInfo *getCurCapturedRegion();

/// Retrieve the current function, if any, that should be analyzed for
/// potential availability violations.
sema::FunctionScopeInfo *getCurFunctionAvailabilityContext();

/// WeakTopLevelDeclDecls - access to \#pragma weak-generated Decls
SmallVectorImpl<Decl *> &WeakTopLevelDecls() { return WeakTopLevelDecl; }

/// Called before parsing a function declarator belonging to a function
/// declaration.
void ActOnStartFunctionDeclarationDeclarator(Declarator &D,
                                             unsigned TemplateParameterDepth);

/// Called after parsing a function declarator belonging to a function
/// declaration.
void ActOnFinishFunctionDeclarationDeclarator(Declarator &D);

void ActOnComment(SourceRange Comment);

//===--------------------------------------------------------------------===//
// Type Analysis / Processing: SemaType.cpp.
//

QualType BuildQualifiedType(QualType T, SourceLocation Loc, Qualifiers Qs,
                            const DeclSpec *DS = nullptr);
QualType BuildQualifiedType(QualType T, SourceLocation Loc, unsigned CVRA,
                            const DeclSpec *DS = nullptr);
QualType BuildPointerType(QualType T,
                          SourceLocation Loc, DeclarationName Entity);
QualType BuildReferenceType(QualType T, bool LValueRef,
                            SourceLocation Loc, DeclarationName Entity);
QualType BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
                        Expr *ArraySize, unsigned Quals,
                        SourceRange Brackets, DeclarationName Entity);
QualType BuildVectorType(QualType T, Expr *VecSize, SourceLocation AttrLoc);
QualType BuildExtVectorType(QualType T, Expr *ArraySize,
                            SourceLocation AttrLoc);
QualType BuildMatrixType(QualType T, Expr *NumRows, Expr *NumColumns,
                         SourceLocation AttrLoc);

QualType BuildAddressSpaceAttr(QualType &T, LangAS ASIdx, Expr *AddrSpace,
                               SourceLocation AttrLoc);

/// Same as above, but constructs the AddressSpace index if not provided.
QualType BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
                               SourceLocation AttrLoc);

bool CheckQualifiedFunctionForTypeId(QualType T, SourceLocation Loc);

bool CheckFunctionReturnType(QualType T, SourceLocation Loc);

/// Build a function type.
///
/// This routine checks the function type according to C++ rules and
/// under the assumption that the result type and parameter types have
/// just been instantiated from a template. It therefore duplicates
/// some of the behavior of GetTypeForDeclarator, but in a much
/// simpler form that is only suitable for this narrow use case.
///
/// \param T The return type of the function.
///
/// \param ParamTypes The parameter types of the function. This array
/// will be modified to account for adjustments to the types of the
/// function parameters.
///
/// \param Loc The location of the entity whose type involves this
/// function type or, if there is no such entity, the location of the
/// type that will have function type.
///
/// \param Entity The name of the entity that involves the function
/// type, if known.
///
/// \param EPI Extra information about the function type. Usually this will
/// be taken from an existing function with the same prototype.
///
/// \returns A suitable function type, if there are no errors. The
/// unqualified type will always be a FunctionProtoType.
/// Otherwise, returns a NULL type.
QualType BuildFunctionType(QualType T,
                           MutableArrayRef<QualType> ParamTypes,
                           SourceLocation Loc, DeclarationName Entity,
                           const FunctionProtoType::ExtProtoInfo &EPI);

QualType BuildMemberPointerType(QualType T, QualType Class,
                                SourceLocation Loc,
                                DeclarationName Entity);
QualType BuildBlockPointerType(QualType T,
                               SourceLocation Loc, DeclarationName Entity);
QualType BuildParenType(QualType T);
QualType BuildAtomicType(QualType T, SourceLocation Loc);
QualType BuildReadPipeType(QualType T,
                       SourceLocation Loc);
QualType BuildWritePipeType(QualType T,
                       SourceLocation Loc);
QualType BuildExtIntType(bool IsUnsigned, Expr *BitWidth, SourceLocation Loc);

TypeSourceInfo *GetTypeForDeclarator(Declarator &D, Scope *S);
TypeSourceInfo *GetTypeForDeclaratorCast(Declarator &D, QualType FromTy);

/// Package the given type and TSI into a ParsedType.
ParsedType CreateParsedType(QualType T, TypeSourceInfo *TInfo);
DeclarationNameInfo GetNameForDeclarator(Declarator &D);
DeclarationNameInfo GetNameFromUnqualifiedId(const UnqualifiedId &Name);
static QualType GetTypeFromParser(ParsedType Ty,
                                  TypeSourceInfo **TInfo = nullptr);
CanThrowResult canThrow(const Stmt *E);
/// Determine whether the callee of a particular function call can throw.
/// E, D and Loc are all optional.
static CanThrowResult canCalleeThrow(Sema &S, const Expr *E, const Decl *D,
                                     SourceLocation Loc = SourceLocation());
const FunctionProtoType *ResolveExceptionSpec(SourceLocation Loc,
                                              const FunctionProtoType *FPT);
void UpdateExceptionSpec(FunctionDecl *FD,
                         const FunctionProtoType::ExceptionSpecInfo &ESI);
bool CheckSpecifiedExceptionType(QualType &T, SourceRange Range);
bool CheckDistantExceptionSpec(QualType T);
bool CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New);
bool CheckEquivalentExceptionSpec(
    const FunctionProtoType *Old, SourceLocation OldLoc,
    const FunctionProtoType *New, SourceLocation NewLoc);
bool CheckEquivalentExceptionSpec(
    const PartialDiagnostic &DiagID, const PartialDiagnostic & NoteID,
    const FunctionProtoType *Old, SourceLocation OldLoc,
    const FunctionProtoType *New, SourceLocation NewLoc);
bool handlerCanCatch(QualType HandlerType, QualType ExceptionType);
bool CheckExceptionSpecSubset(const PartialDiagnostic &DiagID,
                              const PartialDiagnostic &NestedDiagID,
                              const PartialDiagnostic &NoteID,
                              const PartialDiagnostic &NoThrowDiagID,
                              const FunctionProtoType *Superset,
                              SourceLocation SuperLoc,
                              const FunctionProtoType *Subset,
                              SourceLocation SubLoc);
bool CheckParamExceptionSpec(const PartialDiagnostic &NestedDiagID,
                             const PartialDiagnostic &NoteID,
                             const FunctionProtoType *Target,
                             SourceLocation TargetLoc,
                             const FunctionProtoType *Source,
                             SourceLocation SourceLoc);

TypeResult ActOnTypeName(Scope *S, Declarator &D);

/// The parser has parsed the context-sensitive type 'instancetype'
/// in an Objective-C message declaration. Return the appropriate type.
ParsedType ActOnObjCInstanceType(SourceLocation Loc);

/// Abstract class used to diagnose incomplete types.
struct TypeDiagnoser {
  TypeDiagnoser() {}

  virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) = 0;
  virtual ~TypeDiagnoser() {}
};

static int getPrintable(int I) { return I; }
static unsigned getPrintable(unsigned I) { return I; }
static bool getPrintable(bool B) { return B; }
static const char * getPrintable(const char *S) { return S; }
static StringRef getPrintable(StringRef S) { return S; }
static const std::string &getPrintable(const std::string &S) { return S; }
static const IdentifierInfo *getPrintable(const IdentifierInfo *II) {
  return II;
}
static DeclarationName getPrintable(DeclarationName N) { return N; }
static QualType getPrintable(QualType T) { return T; }
static SourceRange getPrintable(SourceRange R) { return R; }
static SourceRange getPrintable(SourceLocation L) { return L; }
static SourceRange getPrintable(const Expr *E) { return E->getSourceRange(); }
static SourceRange getPrintable(TypeLoc TL) { return TL.getSourceRange();}

template <typename... Ts> class BoundTypeDiagnoser : public TypeDiagnoser {
protected:
  unsigned DiagID;
  std::tuple<const Ts &...> Args;

  template <std::size_t... Is>
  void emit(const SemaDiagnosticBuilder &DB,
            std::index_sequence<Is...>) const {
    // Apply all tuple elements to the builder in order.
    bool Dummy[] = {false, (DB << getPrintable(std::get<Is>(Args)))...};
    (void)Dummy;
  }

public:
  BoundTypeDiagnoser(unsigned DiagID, const Ts &...Args)
      : TypeDiagnoser(), DiagID(DiagID), Args(Args...) {
    assert(DiagID != 0 && "no diagnostic for type diagnoser")((void)0);
  }

  void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
    const SemaDiagnosticBuilder &DB = S.Diag(Loc, DiagID);
    emit(DB, std::index_sequence_for<Ts...>());
    DB << T;
  }
};

/// Do a check to make sure \p Name looks like a legal argument for the
/// swift_name attribute applied to decl \p D.  Raise a diagnostic if the name
/// is invalid for the given declaration.
///
/// \p AL is used to provide caret diagnostics in case of a malformed name.
///
/// \returns true if the name is a valid swift name for \p D, false otherwise.
bool DiagnoseSwiftName(Decl *D, StringRef Name, SourceLocation Loc,
                       const ParsedAttr &AL, bool IsAsync);

/// A derivative of BoundTypeDiagnoser for which the diagnostic's type
/// parameter is preceded by a 0/1 enum that is 1 if the type is sizeless.
/// For example, a diagnostic with no other parameters would generally have
/// the form "...%select{incomplete|sizeless}0 type %1...".
template <typename... Ts>
class SizelessTypeDiagnoser : public BoundTypeDiagnoser<Ts...> {
public:
  SizelessTypeDiagnoser(unsigned DiagID, const Ts &... Args)
      : BoundTypeDiagnoser<Ts...>(DiagID, Args...) {}

  void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
    const SemaDiagnosticBuilder &DB = S.Diag(Loc, this->DiagID);
    this->emit(DB, std::index_sequence_for<Ts...>());
    DB << T->isSizelessType() << T;
  }
};

enum class CompleteTypeKind {
  /// Apply the normal rules for complete types.  In particular,
  /// treat all sizeless types as incomplete.
  Normal,

  /// Relax the normal rules for complete types so that they include
  /// sizeless built-in types.
  AcceptSizeless,

  // FIXME: Eventually we should flip the default to Normal and opt in
  // to AcceptSizeless rather than opt out of it.
  Default = AcceptSizeless
};

2153private:
/// Methods for marking which expressions involve dereferencing a pointer
/// marked with the 'noderef' attribute. Expressions are checked bottom up as
/// they are parsed, meaning that a noderef pointer may not be accessed. For
/// example, in `&*p` where `p` is a noderef pointer, we will first parse the
/// `*p`, but need to check that `address of` is called on it. This requires
/// keeping a container of all pending expressions and checking if the address
/// of them are eventually taken.
void CheckSubscriptAccessOfNoDeref(const ArraySubscriptExpr *E);
void CheckAddressOfNoDeref(const Expr *E);
void CheckMemberAccessOfNoDeref(const MemberExpr *E);

bool RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
                             CompleteTypeKind Kind, TypeDiagnoser *Diagnoser);

struct ModuleScope {
  SourceLocation BeginLoc;
  clang::Module *Module = nullptr;
  bool ModuleInterface = false;
  bool ImplicitGlobalModuleFragment = false;
  VisibleModuleSet OuterVisibleModules;
};
/// The modules we're currently parsing.
llvm::SmallVector<ModuleScope, 16> ModuleScopes;

/// Namespace definitions that we will export when they finish.
llvm::SmallPtrSet<const NamespaceDecl*, 8> DeferredExportedNamespaces;

/// Get the module whose scope we are currently within.
Module *getCurrentModule() const {
  return ModuleScopes.empty() ? nullptr : ModuleScopes.back().Module;
}

VisibleModuleSet VisibleModules;

2188public:
/// Get the module owning an entity.
Module *getOwningModule(const Decl *Entity) {
  return Entity->getOwningModule();
}

/// Make a merged definition of an existing hidden definition \p ND
/// visible at the specified location.
void makeMergedDefinitionVisible(NamedDecl *ND);

bool isModuleVisible(const Module *M, bool ModulePrivate = false);

// When loading a non-modular PCH files, this is used to restore module
// visibility.
void makeModuleVisible(Module *Mod, SourceLocation ImportLoc) {
  VisibleModules.setVisible(Mod, ImportLoc);
}

/// Determine whether a declaration is visible to name lookup.
bool isVisible(const NamedDecl *D) {
  return D->isUnconditionallyVisible() || isVisibleSlow(D);
}

/// Determine whether any declaration of an entity is visible.
bool
hasVisibleDeclaration(const NamedDecl *D,
                      llvm::SmallVectorImpl<Module *> *Modules = nullptr) {
  return isVisible(D) || hasVisibleDeclarationSlow(D, Modules);
}
bool hasVisibleDeclarationSlow(const NamedDecl *D,
                               llvm::SmallVectorImpl<Module *> *Modules);

bool hasVisibleMergedDefinition(NamedDecl *Def);
bool hasMergedDefinitionInCurrentModule(NamedDecl *Def);

/// Determine if \p D and \p Suggested have a structurally compatible
/// layout as described in C11 6.2.7/1.
bool hasStructuralCompatLayout(Decl *D, Decl *Suggested);

/// Determine if \p D has a visible definition. If not, suggest a declaration
/// that should be made visible to expose the definition.
bool hasVisibleDefinition(NamedDecl *D, NamedDecl **Suggested,
                          bool OnlyNeedComplete = false);
bool hasVisibleDefinition(const NamedDecl *D) {
  NamedDecl *Hidden;
  return hasVisibleDefinition(const_cast<NamedDecl*>(D), &Hidden);
}

/// Determine if the template parameter \p D has a visible default argument.
bool
hasVisibleDefaultArgument(const NamedDecl *D,
                          llvm::SmallVectorImpl<Module *> *Modules = nullptr);

/// Determine if there is a visible declaration of \p D that is an explicit
/// specialization declaration for a specialization of a template. (For a
/// member specialization, use hasVisibleMemberSpecialization.)
bool hasVisibleExplicitSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);

/// Determine if there is a visible declaration of \p D that is a member
/// specialization declaration (as opposed to an instantiated declaration).
bool hasVisibleMemberSpecialization(
    const NamedDecl *D, llvm::SmallVectorImpl<Module *> *Modules = nullptr);

/// Determine if \p A and \p B are equivalent internal linkage declarations
/// from different modules, and thus an ambiguity error can be downgraded to
/// an extension warning.
bool isEquivalentInternalLinkageDeclaration(const NamedDecl *A,
                                            const NamedDecl *B);
void diagnoseEquivalentInternalLinkageDeclarations(
    SourceLocation Loc, const NamedDecl *D,
    ArrayRef<const NamedDecl *> Equiv);

bool isUsualDeallocationFunction(const CXXMethodDecl *FD);

bool isCompleteType(SourceLocation Loc, QualType T,
                    CompleteTypeKind Kind = CompleteTypeKind::Default) {
  return !RequireCompleteTypeImpl(Loc, T, Kind, nullptr);
}
bool RequireCompleteType(SourceLocation Loc, QualType T,
                         CompleteTypeKind Kind, TypeDiagnoser &Diagnoser);
bool RequireCompleteType(SourceLocation Loc, QualType T,
                         CompleteTypeKind Kind, unsigned DiagID);

bool RequireCompleteType(SourceLocation Loc, QualType T,
                         TypeDiagnoser &Diagnoser) {
  return RequireCompleteType(Loc, T, CompleteTypeKind::Default, Diagnoser);
}
bool RequireCompleteType(SourceLocation Loc, QualType T, unsigned DiagID) {
  return RequireCompleteType(Loc, T, CompleteTypeKind::Default, DiagID);
}

template <typename... Ts>
bool RequireCompleteType(SourceLocation Loc, QualType T, unsigned DiagID,
                         const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteType(Loc, T, Diagnoser);
}

template <typename... Ts>
bool RequireCompleteSizedType(SourceLocation Loc, QualType T, unsigned DiagID,
                              const Ts &... Args) {
  SizelessTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteType(Loc, T, CompleteTypeKind::Normal, Diagnoser);
}

/// Get the type of expression E, triggering instantiation to complete the
/// type if necessary -- that is, if the expression refers to a templated
/// static data member of incomplete array type.
///
/// May still return an incomplete type if instantiation was not possible or
/// if the type is incomplete for a different reason. Use
/// RequireCompleteExprType instead if a diagnostic is expected for an
/// incomplete expression type.
QualType getCompletedType(Expr *E);

void completeExprArrayBound(Expr *E);
bool RequireCompleteExprType(Expr *E, CompleteTypeKind Kind,
                             TypeDiagnoser &Diagnoser);
bool RequireCompleteExprType(Expr *E, unsigned DiagID);

template <typename... Ts>
bool RequireCompleteExprType(Expr *E, unsigned DiagID, const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteExprType(E, CompleteTypeKind::Default, Diagnoser);
}

template <typename... Ts>
bool RequireCompleteSizedExprType(Expr *E, unsigned DiagID,
                                  const Ts &... Args) {
  SizelessTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireCompleteExprType(E, CompleteTypeKind::Normal, Diagnoser);
}

bool RequireLiteralType(SourceLocation Loc, QualType T,
                        TypeDiagnoser &Diagnoser);
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID);

template <typename... Ts>
bool RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID,
                        const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireLiteralType(Loc, T, Diagnoser);
}

QualType getElaboratedType(ElaboratedTypeKeyword Keyword,
                           const CXXScopeSpec &SS, QualType T,
                           TagDecl *OwnedTagDecl = nullptr);

QualType getDecltypeForParenthesizedExpr(Expr *E);
QualType BuildTypeofExprType(Expr *E, SourceLocation Loc);
/// If AsUnevaluated is false, E is treated as though it were an evaluated
/// context, such as when building a type for decltype(auto).
QualType BuildDecltypeType(Expr *E, SourceLocation Loc,
                           bool AsUnevaluated = true);
QualType BuildUnaryTransformType(QualType BaseType,
                                 UnaryTransformType::UTTKind UKind,
                                 SourceLocation Loc);

//===--------------------------------------------------------------------===//
// Symbol table / Decl tracking callbacks: SemaDecl.cpp.
//

struct SkipBodyInfo {
  SkipBodyInfo()
      : ShouldSkip(false), CheckSameAsPrevious(false), Previous(nullptr),
        New(nullptr) {}
  bool ShouldSkip;
  bool CheckSameAsPrevious;
  NamedDecl *Previous;
  NamedDecl *New;
};

DeclGroupPtrTy ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType = nullptr);

void DiagnoseUseOfUnimplementedSelectors();

bool isSimpleTypeSpecifier(tok::TokenKind Kind) const;

ParsedType getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
                       Scope *S, CXXScopeSpec *SS = nullptr,
                       bool isClassName = false, bool HasTrailingDot = false,
                       ParsedType ObjectType = nullptr,
                       bool IsCtorOrDtorName = false,
                       bool WantNontrivialTypeSourceInfo = false,
                       bool IsClassTemplateDeductionContext = true,
                       IdentifierInfo **CorrectedII = nullptr);
TypeSpecifierType isTagName(IdentifierInfo &II, Scope *S);
bool isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S);
void DiagnoseUnknownTypeName(IdentifierInfo *&II,
                             SourceLocation IILoc,
                             Scope *S,
                             CXXScopeSpec *SS,
                             ParsedType &SuggestedType,
                             bool IsTemplateName = false);

/// Attempt to behave like MSVC in situations where lookup of an unqualified
/// type name has failed in a dependent context. In these situations, we
/// automatically form a DependentTypeName that will retry lookup in a related
/// scope during instantiation.
ParsedType ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
                                    SourceLocation NameLoc,
                                    bool IsTemplateTypeArg);

/// Describes the result of the name lookup and resolution performed
/// by \c ClassifyName().
enum NameClassificationKind {
  /// This name is not a type or template in this context, but might be
  /// something else.
  NC_Unknown,
  /// Classification failed; an error has been produced.
  NC_Error,
  /// The name has been typo-corrected to a keyword.
  NC_Keyword,
  /// The name was classified as a type.
  NC_Type,
  /// The name was classified as a specific non-type, non-template
  /// declaration. ActOnNameClassifiedAsNonType should be called to
  /// convert the declaration to an expression.
  NC_NonType,
  /// The name was classified as an ADL-only function name.
  /// ActOnNameClassifiedAsUndeclaredNonType should be called to convert the
  /// result to an expression.
  NC_UndeclaredNonType,
  /// The name denotes a member of a dependent type that could not be
  /// resolved. ActOnNameClassifiedAsDependentNonType should be called to
  /// convert the result to an expression.
  NC_DependentNonType,
  /// The name was classified as an overload set, and an expression
  /// representing that overload set has been formed.
  /// ActOnNameClassifiedAsOverloadSet should be called to form a suitable
  /// expression referencing the overload set.
  NC_OverloadSet,
  /// The name was classified as a template whose specializations are types.
  NC_TypeTemplate,
  /// The name was classified as a variable template name.
  NC_VarTemplate,
  /// The name was classified as a function template name.
  NC_FunctionTemplate,
  /// The name was classified as an ADL-only function template name.
  NC_UndeclaredTemplate,
  /// The name was classified as a concept name.
  NC_Concept,
};

class NameClassification {
  NameClassificationKind Kind;
  union {
    ExprResult Expr;
    NamedDecl *NonTypeDecl;
    TemplateName Template;
    ParsedType Type;
  };

  explicit NameClassification(NameClassificationKind Kind) : Kind(Kind) {}

public:
  NameClassification(ParsedType Type) : Kind(NC_Type), Type(Type) {}

  NameClassification(const IdentifierInfo *Keyword) : Kind(NC_Keyword) {}

  static NameClassification Error() {
    return NameClassification(NC_Error);
  }

  static NameClassification Unknown() {
    return NameClassification(NC_Unknown);
  }

  static NameClassification OverloadSet(ExprResult E) {
    NameClassification Result(NC_OverloadSet);
    Result.Expr = E;
    return Result;
  }

  static NameClassification NonType(NamedDecl *D) {
    NameClassification Result(NC_NonType);
    Result.NonTypeDecl = D;
    return Result;
  }

  static NameClassification UndeclaredNonType() {
    return NameClassification(NC_UndeclaredNonType);
  }

  static NameClassification DependentNonType() {
    return NameClassification(NC_DependentNonType);
  }

  static NameClassification TypeTemplate(TemplateName Name) {
    NameClassification Result(NC_TypeTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification VarTemplate(TemplateName Name) {
    NameClassification Result(NC_VarTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification FunctionTemplate(TemplateName Name) {
    NameClassification Result(NC_FunctionTemplate);
    Result.Template = Name;
    return Result;
  }

  static NameClassification Concept(TemplateName Name) {
    NameClassification Result(NC_Concept);
    Result.Template = Name;
    return Result;
  }

  static NameClassification UndeclaredTemplate(TemplateName Name) {
    NameClassification Result(NC_UndeclaredTemplate);
    Result.Template = Name;
    return Result;
  }

  NameClassificationKind getKind() const { return Kind; }

  ExprResult getExpression() const {
    assert(Kind == NC_OverloadSet)((void)0);
    return Expr;
  }

  ParsedType getType() const {
    assert(Kind == NC_Type)((void)0);
    return Type;
  }

  NamedDecl *getNonTypeDecl() const {
    assert(Kind == NC_NonType)((void)0);
    return NonTypeDecl;
  }

  TemplateName getTemplateName() const {
    assert(Kind == NC_TypeTemplate || Kind == NC_FunctionTemplate ||((void)0)
           Kind == NC_VarTemplate || Kind == NC_Concept ||((void)0)
           Kind == NC_UndeclaredTemplate)((void)0);
    return Template;
  }

  TemplateNameKind getTemplateNameKind() const {
    switch (Kind) {
    case NC_TypeTemplate:
      return TNK_Type_template;
    case NC_FunctionTemplate:
      return TNK_Function_template;
    case NC_VarTemplate:
      return TNK_Var_template;
    case NC_Concept:
      return TNK_Concept_template;
    case NC_UndeclaredTemplate:
      return TNK_Undeclared_template;
    default:
      llvm_unreachable("unsupported name classification.")__builtin_unreachable();
    }
  }
};

/// Perform name lookup on the given name, classifying it based on
/// the results of name lookup and the following token.
///
/// This routine is used by the parser to resolve identifiers and help direct
/// parsing. When the identifier cannot be found, this routine will attempt
/// to correct the typo and classify based on the resulting name.
///
/// \param S The scope in which we're performing name lookup.
///
/// \param SS The nested-name-specifier that precedes the name.
///
/// \param Name The identifier. If typo correction finds an alternative name,
/// this pointer parameter will be updated accordingly.
///
/// \param NameLoc The location of the identifier.
///
/// \param NextToken The token following the identifier. Used to help
/// disambiguate the name.
///
/// \param CCC The correction callback, if typo correction is desired.
NameClassification ClassifyName(Scope *S, CXXScopeSpec &SS,
                                IdentifierInfo *&Name, SourceLocation NameLoc,
                                const Token &NextToken,
                                CorrectionCandidateCallback *CCC = nullptr);

/// Act on the result of classifying a name as an undeclared (ADL-only)
/// non-type declaration.
ExprResult ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
                                                  SourceLocation NameLoc);
/// Act on the result of classifying a name as an undeclared member of a
/// dependent base class.
ExprResult ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
                                                 IdentifierInfo *Name,
                                                 SourceLocation NameLoc,
                                                 bool IsAddressOfOperand);
/// Act on the result of classifying a name as a specific non-type
/// declaration.
ExprResult ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
                                        NamedDecl *Found,
                                        SourceLocation NameLoc,
                                        const Token &NextToken);
/// Act on the result of classifying a name as an overload set.
ExprResult ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *OverloadSet);

/// Describes the detailed kind of a template name. Used in diagnostics.
enum class TemplateNameKindForDiagnostics {
  ClassTemplate,
  FunctionTemplate,
  VarTemplate,
  AliasTemplate,
  TemplateTemplateParam,
  Concept,
  DependentTemplate
};
TemplateNameKindForDiagnostics
getTemplateNameKindForDiagnostics(TemplateName Name);

/// Determine whether it's plausible that E was intended to be a
/// template-name.
bool mightBeIntendedToBeTemplateName(ExprResult E, bool &Dependent) {
  if (!getLangOpts().CPlusPlus || E.isInvalid())
    return false;
  Dependent = false;
  if (auto *DRE = dyn_cast<DeclRefExpr>(E.get()))
    return !DRE->hasExplicitTemplateArgs();
  if (auto *ME = dyn_cast<MemberExpr>(E.get()))
    return !ME->hasExplicitTemplateArgs();
  Dependent = true;
  if (auto *DSDRE = dyn_cast<DependentScopeDeclRefExpr>(E.get()))
    return !DSDRE->hasExplicitTemplateArgs();
  if (auto *DSME = dyn_cast<CXXDependentScopeMemberExpr>(E.get()))
    return !DSME->hasExplicitTemplateArgs();
  // Any additional cases recognized here should also be handled by
  // diagnoseExprIntendedAsTemplateName.
  return false;
}
void diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
                                        SourceLocation Less,
                                        SourceLocation Greater);

void warnOnReservedIdentifier(const NamedDecl *D);

Decl *ActOnDeclarator(Scope *S, Declarator &D);

NamedDecl *HandleDeclarator(Scope *S, Declarator &D,
                            MultiTemplateParamsArg TemplateParameterLists);
bool tryToFixVariablyModifiedVarType(TypeSourceInfo *&TInfo,
                                     QualType &T, SourceLocation Loc,
                                     unsigned FailedFoldDiagID);
void RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S);
bool DiagnoseClassNameShadow(DeclContext *DC, DeclarationNameInfo Info);
bool diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
                                  DeclarationName Name, SourceLocation Loc,
                                  bool IsTemplateId);
void
diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
                          SourceLocation FallbackLoc,
                          SourceLocation ConstQualLoc = SourceLocation(),
                          SourceLocation VolatileQualLoc = SourceLocation(),
                          SourceLocation RestrictQualLoc = SourceLocation(),
                          SourceLocation AtomicQualLoc = SourceLocation(),
                          SourceLocation UnalignedQualLoc = SourceLocation());

static bool adjustContextForLocalExternDecl(DeclContext *&DC);
void DiagnoseFunctionSpecifiers(const DeclSpec &DS);
NamedDecl *getShadowedDeclaration(const TypedefNameDecl *D,
                                  const LookupResult &R);
NamedDecl *getShadowedDeclaration(const VarDecl *D, const LookupResult &R);
NamedDecl *getShadowedDeclaration(const BindingDecl *D,
                                  const LookupResult &R);
void CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
                 const LookupResult &R);
void CheckShadow(Scope *S, VarDecl *D);

/// Warn if 'E', which is an expression that is about to be modified, refers
/// to a shadowing declaration.
void CheckShadowingDeclModification(Expr *E, SourceLocation Loc);

void DiagnoseShadowingLambdaDecls(const sema::LambdaScopeInfo *LSI);

2669private:
/// Map of current shadowing declarations to shadowed declarations. Warn if
/// it looks like the user is trying to modify the shadowing declaration.
llvm::DenseMap<const NamedDecl *, const NamedDecl *> ShadowingDecls;

2674public:
void CheckCastAlign(Expr *Op, QualType T, SourceRange TRange);
void handleTagNumbering(const TagDecl *Tag, Scope *TagScope);
void setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
                                  TypedefNameDecl *NewTD);
void CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *D);
NamedDecl* ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                                  TypeSourceInfo *TInfo,
                                  LookupResult &Previous);
NamedDecl* ActOnTypedefNameDecl(Scope* S, DeclContext* DC, TypedefNameDecl *D,
                                LookupResult &Previous, bool &Redeclaration);
NamedDecl *ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
                                   TypeSourceInfo *TInfo,
                                   LookupResult &Previous,
                                   MultiTemplateParamsArg TemplateParamLists,
                                   bool &AddToScope,
                                   ArrayRef<BindingDecl *> Bindings = None);
NamedDecl *
ActOnDecompositionDeclarator(Scope *S, Declarator &D,
                             MultiTemplateParamsArg TemplateParamLists);
// Returns true if the variable declaration is a redeclaration
bool CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous);
void CheckVariableDeclarationType(VarDecl *NewVD);
bool DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
                                   Expr *Init);
void CheckCompleteVariableDeclaration(VarDecl *VD);
void CheckCompleteDecompositionDeclaration(DecompositionDecl *DD);
void MaybeSuggestAddingStaticToDecl(const FunctionDecl *D);

NamedDecl* ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                                   TypeSourceInfo *TInfo,
                                   LookupResult &Previous,
                                   MultiTemplateParamsArg TemplateParamLists,
                                   bool &AddToScope);
bool AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD);

enum class CheckConstexprKind {
  /// Diagnose issues that are non-constant or that are extensions.
  Diagnose,
  /// Identify whether this function satisfies the formal rules for constexpr
  /// functions in the current lanugage mode (with no extensions).
  CheckValid
};

bool CheckConstexprFunctionDefinition(const FunctionDecl *FD,
                                      CheckConstexprKind Kind);

void DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD);
void FindHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
void NoteHiddenVirtualMethods(CXXMethodDecl *MD,
                        SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods);
// Returns true if the function declaration is a redeclaration
bool CheckFunctionDeclaration(Scope *S,
                              FunctionDecl *NewFD, LookupResult &Previous,
                              bool IsMemberSpecialization);
bool shouldLinkDependentDeclWithPrevious(Decl *D, Decl *OldDecl);
bool canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
                                    QualType NewT, QualType OldT);
void CheckMain(FunctionDecl *FD, const DeclSpec &D);
void CheckMSVCRTEntryPoint(FunctionDecl *FD);
Attr *getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
                                                 bool IsDefinition);
void CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D);
Decl *ActOnParamDeclarator(Scope *S, Declarator &D);
ParmVarDecl *BuildParmVarDeclForTypedef(DeclContext *DC,
                                        SourceLocation Loc,
                                        QualType T);
ParmVarDecl *CheckParameter(DeclContext *DC, SourceLocation StartLoc,
                            SourceLocation NameLoc, IdentifierInfo *Name,
                            QualType T, TypeSourceInfo *TSInfo,
                            StorageClass SC);
void ActOnParamDefaultArgument(Decl *param,
                               SourceLocation EqualLoc,
                               Expr *defarg);
void ActOnParamUnparsedDefaultArgument(Decl *param, SourceLocation EqualLoc,
                                       SourceLocation ArgLoc);
void ActOnParamDefaultArgumentError(Decl *param, SourceLocation EqualLoc);
ExprResult ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
                                       SourceLocation EqualLoc);
void SetParamDefaultArgument(ParmVarDecl *Param, Expr *DefaultArg,
                             SourceLocation EqualLoc);

// Contexts where using non-trivial C union types can be disallowed. This is
// passed to err_non_trivial_c_union_in_invalid_context.
enum NonTrivialCUnionContext {
  // Function parameter.
  NTCUC_FunctionParam,
  // Function return.
  NTCUC_FunctionReturn,
  // Default-initialized object.
  NTCUC_DefaultInitializedObject,
  // Variable with automatic storage duration.
  NTCUC_AutoVar,
  // Initializer expression that might copy from another object.
  NTCUC_CopyInit,
  // Assignment.
  NTCUC_Assignment,
  // Compound literal.
  NTCUC_CompoundLiteral,
  // Block capture.
  NTCUC_BlockCapture,
  // lvalue-to-rvalue conversion of volatile type.
  NTCUC_LValueToRValueVolatile,
};

/// Emit diagnostics if the initializer or any of its explicit or
/// implicitly-generated subexpressions require copying or
/// default-initializing a type that is or contains a C union type that is
/// non-trivial to copy or default-initialize.
void checkNonTrivialCUnionInInitializer(const Expr *Init, SourceLocation Loc);

// These flags are passed to checkNonTrivialCUnion.
enum NonTrivialCUnionKind {
  NTCUK_Init = 0x1,
  NTCUK_Destruct = 0x2,
  NTCUK_Copy = 0x4,
};

/// Emit diagnostics if a non-trivial C union type or a struct that contains
/// a non-trivial C union is used in an invalid context.
void checkNonTrivialCUnion(QualType QT, SourceLocation Loc,
                           NonTrivialCUnionContext UseContext,
                           unsigned NonTrivialKind);

void AddInitializerToDecl(Decl *dcl, Expr *init, bool DirectInit);
void ActOnUninitializedDecl(Decl *dcl);
void ActOnInitializerError(Decl *Dcl);

void ActOnPureSpecifier(Decl *D, SourceLocation PureSpecLoc);
void ActOnCXXForRangeDecl(Decl *D);
StmtResult ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
                                      IdentifierInfo *Ident,
                                      ParsedAttributes &Attrs,
                                      SourceLocation AttrEnd);
void SetDeclDeleted(Decl *dcl, SourceLocation DelLoc);
void SetDeclDefaulted(Decl *dcl, SourceLocation DefaultLoc);
void CheckStaticLocalForDllExport(VarDecl *VD);
void FinalizeDeclaration(Decl *D);
DeclGroupPtrTy FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
                                       ArrayRef<Decl *> Group);
DeclGroupPtrTy BuildDeclaratorGroup(MutableArrayRef<Decl *> Group);

/// Should be called on all declarations that might have attached
/// documentation comments.
void ActOnDocumentableDecl(Decl *D);
void ActOnDocumentableDecls(ArrayRef<Decl *> Group);

void ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
                                     SourceLocation LocAfterDecls);
void CheckForFunctionRedefinition(
    FunctionDecl *FD, const FunctionDecl *EffectiveDefinition = nullptr,
    SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnStartOfFunctionDef(Scope *S, Declarator &D,
                              MultiTemplateParamsArg TemplateParamLists,
                              SkipBodyInfo *SkipBody = nullptr);
Decl *ActOnStartOfFunctionDef(Scope *S, Decl *D,
                              SkipBodyInfo *SkipBody = nullptr);
void ActOnStartTrailingRequiresClause(Scope *S, Declarator &D);
ExprResult ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr);
ExprResult ActOnRequiresClause(ExprResult ConstraintExpr);
void ActOnStartOfObjCMethodDef(Scope *S, Decl *D);
bool isObjCMethodDecl(Decl *D) {
  return D && isa<ObjCMethodDecl>(D);
}

/// Determine whether we can delay parsing the body of a function or
/// function template until it is used, assuming we don't care about emitting
/// code for that function.
///
/// This will be \c false if we may need the body of the function in the
/// middle of parsing an expression (where it's impractical to switch to
/// parsing a different function), for instance, if it's constexpr in C++11
/// or has an 'auto' return type in C++14. These cases are essentially bugs.
bool canDelayFunctionBody(const Declarator &D);

/// Determine whether we can skip parsing the body of a function
/// definition, assuming we don't care about analyzing its body or emitting
/// code for that function.
///
/// This will be \c false only if we may need the body of the function in
/// order to parse the rest of the program (for instance, if it is
/// \c constexpr in C++11 or has an 'auto' return type in C++14).
bool canSkipFunctionBody(Decl *D);

void computeNRVO(Stmt *Body, sema::FunctionScopeInfo *Scope);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body);
Decl *ActOnFinishFunctionBody(Decl *Decl, Stmt *Body, bool IsInstantiation);
Decl *ActOnSkippedFunctionBody(Decl *Decl);
void ActOnFinishInlineFunctionDef(FunctionDecl *D);

/// ActOnFinishDelayedAttribute - Invoked when we have finished parsing an
/// attribute for which parsing is delayed.
void ActOnFinishDelayedAttribute(Scope *S, Decl *D, ParsedAttributes &Attrs);

/// Diagnose any unused parameters in the given sequence of
/// ParmVarDecl pointers.
void DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters);

/// Diagnose whether the size of parameters or return value of a
/// function or obj-c method definition is pass-by-value and larger than a
/// specified threshold.
void
DiagnoseSizeOfParametersAndReturnValue(ArrayRef<ParmVarDecl *> Parameters,
                                       QualType ReturnTy, NamedDecl *D);

void DiagnoseInvalidJumps(Stmt *Body);
Decl *ActOnFileScopeAsmDecl(Expr *expr,
                            SourceLocation AsmLoc,
                            SourceLocation RParenLoc);

/// Handle a C++11 empty-declaration and attribute-declaration.
Decl *ActOnEmptyDeclaration(Scope *S, const ParsedAttributesView &AttrList,
                            SourceLocation SemiLoc);

enum class ModuleDeclKind {
  Interface,      ///< 'export module X;'
  Implementation, ///< 'module X;'
};

/// The parser has processed a module-declaration that begins the definition
/// of a module interface or implementation.
DeclGroupPtrTy ActOnModuleDecl(SourceLocation StartLoc,
                               SourceLocation ModuleLoc, ModuleDeclKind MDK,
                               ModuleIdPath Path, bool IsFirstDecl);

/// The parser has processed a global-module-fragment declaration that begins
/// the definition of the global module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
DeclGroupPtrTy ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc);

/// The parser has processed a private-module-fragment declaration that begins
/// the definition of the private module fragment of the current module unit.
/// \param ModuleLoc The location of the 'module' keyword.
/// \param PrivateLoc The location of the 'private' keyword.
DeclGroupPtrTy ActOnPrivateModuleFragmentDecl(SourceLocation ModuleLoc,
                                              SourceLocation PrivateLoc);

/// The parser has processed a module import declaration.
///
/// \param StartLoc The location of the first token in the declaration. This
///        could be the location of an '@', 'export', or 'import'.
/// \param ExportLoc The location of the 'export' keyword, if any.
/// \param ImportLoc The location of the 'import' keyword.
/// \param Path The module access path.
DeclResult ActOnModuleImport(SourceLocation StartLoc,
                             SourceLocation ExportLoc,
                             SourceLocation ImportLoc, ModuleIdPath Path);
DeclResult ActOnModuleImport(SourceLocation StartLoc,
                             SourceLocation ExportLoc,
                             SourceLocation ImportLoc, Module *M,
                             ModuleIdPath Path = {});

/// The parser has processed a module import translated from a
/// #include or similar preprocessing directive.
void ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod);
void BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod);

/// The parsed has entered a submodule.
void ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod);
/// The parser has left a submodule.
void ActOnModuleEnd(SourceLocation DirectiveLoc, Module *Mod);

/// Create an implicit import of the given module at the given
/// source location, for error recovery, if possible.
///
/// This routine is typically used when an entity found by name lookup
/// is actually hidden within a module that we know about but the user
/// has forgotten to import.
void createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
                                                Module *Mod);

/// Kinds of missing import. Note, the values of these enumerators correspond
/// to %select values in diagnostics.
enum class MissingImportKind {
  Declaration,
  Definition,
  DefaultArgument,
  ExplicitSpecialization,
  PartialSpecialization
};

/// Diagnose that the specified declaration needs to be visible but
/// isn't, and suggest a module import that would resolve the problem.
void diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
                           MissingImportKind MIK, bool Recover = true);
void diagnoseMissingImport(SourceLocation Loc, NamedDecl *Decl,
                           SourceLocation DeclLoc, ArrayRef<Module *> Modules,
                           MissingImportKind MIK, bool Recover);

Decl *ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
                           SourceLocation LBraceLoc);
Decl *ActOnFinishExportDecl(Scope *S, Decl *ExportDecl,
                            SourceLocation RBraceLoc);

/// We've found a use of a templated declaration that would trigger an
/// implicit instantiation. Check that any relevant explicit specializations
/// and partial specializations are visible, and diagnose if not.
void checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec);

/// Retrieve a suitable printing policy for diagnostics.
PrintingPolicy getPrintingPolicy() const {
  return getPrintingPolicy(Context, PP);
}

/// Retrieve a suitable printing policy for diagnostics.
static PrintingPolicy getPrintingPolicy(const ASTContext &Ctx,
                                        const Preprocessor &PP);

/// Scope actions.
void ActOnPopScope(SourceLocation Loc, Scope *S);
void ActOnTranslationUnitScope(Scope *S);

Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                                 RecordDecl *&AnonRecord);
Decl *ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                                 MultiTemplateParamsArg TemplateParams,
                                 bool IsExplicitInstantiation,
                                 RecordDecl *&AnonRecord);

Decl *BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
                                  AccessSpecifier AS,
                                  RecordDecl *Record,
                                  const PrintingPolicy &Policy);

Decl *BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
                                     RecordDecl *Record);

/// Common ways to introduce type names without a tag for use in diagnostics.
/// Keep in sync with err_tag_reference_non_tag.
enum NonTagKind {
  NTK_NonStruct,
  NTK_NonClass,
  NTK_NonUnion,
  NTK_NonEnum,
  NTK_Typedef,
  NTK_TypeAlias,
  NTK_Template,
  NTK_TypeAliasTemplate,
  NTK_TemplateTemplateArgument,
};

/// Given a non-tag type declaration, returns an enum useful for indicating
/// what kind of non-tag type this is.
NonTagKind getNonTagTypeDeclKind(const Decl *D, TagTypeKind TTK);

bool isAcceptableTagRedeclaration(const TagDecl *Previous,
                                  TagTypeKind NewTag, bool isDefinition,
                                  SourceLocation NewTagLoc,
                                  const IdentifierInfo *Name);

enum TagUseKind {
  TUK_Reference,   // Reference to a tag:  'struct foo *X;'
  TUK_Declaration, // Fwd decl of a tag:   'struct foo;'
  TUK_Definition,  // Definition of a tag: 'struct foo { int X; } Y;'
  TUK_Friend       // Friend declaration:  'friend struct foo;'
};

Decl *ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
               SourceLocation KWLoc, CXXScopeSpec &SS, IdentifierInfo *Name,
               SourceLocation NameLoc, const ParsedAttributesView &Attr,
               AccessSpecifier AS, SourceLocation ModulePrivateLoc,
               MultiTemplateParamsArg TemplateParameterLists, bool &OwnedDecl,
               bool &IsDependent, SourceLocation ScopedEnumKWLoc,
               bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
               bool IsTypeSpecifier, bool IsTemplateParamOrArg,
               SkipBodyInfo *SkipBody = nullptr);

Decl *ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
                              unsigned TagSpec, SourceLocation TagLoc,
                              CXXScopeSpec &SS, IdentifierInfo *Name,
                              SourceLocation NameLoc,
                              const ParsedAttributesView &Attr,
                              MultiTemplateParamsArg TempParamLists);

TypeResult ActOnDependentTag(Scope *S,
                             unsigned TagSpec,
                             TagUseKind TUK,
                             const CXXScopeSpec &SS,
                             IdentifierInfo *Name,
                             SourceLocation TagLoc,
                             SourceLocation NameLoc);

void ActOnDefs(Scope *S, Decl *TagD, SourceLocation DeclStart,
               IdentifierInfo *ClassName,
               SmallVectorImpl<Decl *> &Decls);
Decl *ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
                 Declarator &D, Expr *BitfieldWidth);

FieldDecl *HandleField(Scope *S, RecordDecl *TagD, SourceLocation DeclStart,
                       Declarator &D, Expr *BitfieldWidth,
                       InClassInitStyle InitStyle,
                       AccessSpecifier AS);
MSPropertyDecl *HandleMSProperty(Scope *S, RecordDecl *TagD,
                                 SourceLocation DeclStart, Declarator &D,
                                 Expr *BitfieldWidth,
                                 InClassInitStyle InitStyle,
                                 AccessSpecifier AS,
                                 const ParsedAttr &MSPropertyAttr);

FieldDecl *CheckFieldDecl(DeclarationName Name, QualType T,
                          TypeSourceInfo *TInfo,
                          RecordDecl *Record, SourceLocation Loc,
                          bool Mutable, Expr *BitfieldWidth,
                          InClassInitStyle InitStyle,
                          SourceLocation TSSL,
                          AccessSpecifier AS, NamedDecl *PrevDecl,
                          Declarator *D = nullptr);

bool CheckNontrivialField(FieldDecl *FD);
void DiagnoseNontrivial(const CXXRecordDecl *Record, CXXSpecialMember CSM);

enum TrivialABIHandling {
  /// The triviality of a method unaffected by "trivial_abi".
  TAH_IgnoreTrivialABI,

  /// The triviality of a method affected by "trivial_abi".
  TAH_ConsiderTrivialABI
};

bool SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
                            TrivialABIHandling TAH = TAH_IgnoreTrivialABI,
                            bool Diagnose = false);

/// For a defaulted function, the kind of defaulted function that it is.
class DefaultedFunctionKind {
  CXXSpecialMember SpecialMember : 8;
  DefaultedComparisonKind Comparison : 8;

public:
  DefaultedFunctionKind()
      : SpecialMember(CXXInvalid), Comparison(DefaultedComparisonKind::None) {
  }
  DefaultedFunctionKind(CXXSpecialMember CSM)
      : SpecialMember(CSM), Comparison(DefaultedComparisonKind::None) {}
  DefaultedFunctionKind(DefaultedComparisonKind Comp)
      : SpecialMember(CXXInvalid), Comparison(Comp) {}

  bool isSpecialMember() const { return SpecialMember != CXXInvalid; }
  bool isComparison() const {
    return Comparison != DefaultedComparisonKind::None;
  }

  explicit operator bool() const {
    return isSpecialMember() || isComparison();
  }

  CXXSpecialMember asSpecialMember() const { return SpecialMember; }
  DefaultedComparisonKind asComparison() const { return Comparison; }

  /// Get the index of this function kind for use in diagnostics.
  unsigned getDiagnosticIndex() const {
    static_assert(CXXInvalid > CXXDestructor,
                  "invalid should have highest index");
    static_assert((unsigned)DefaultedComparisonKind::None == 0,
                  "none should be equal to zero");
    return SpecialMember + (unsigned)Comparison;
  }
};

DefaultedFunctionKind getDefaultedFunctionKind(const FunctionDecl *FD);

CXXSpecialMember getSpecialMember(const CXXMethodDecl *MD) {
  return getDefaultedFunctionKind(MD).asSpecialMember();
}
DefaultedComparisonKind getDefaultedComparisonKind(const FunctionDecl *FD) {
  return getDefaultedFunctionKind(FD).asComparison();
}

void ActOnLastBitfield(SourceLocation DeclStart,
                       SmallVectorImpl<Decl *> &AllIvarDecls);
Decl *ActOnIvar(Scope *S, SourceLocation DeclStart,
                Declarator &D, Expr *BitfieldWidth,
                tok::ObjCKeywordKind visibility);

// This is used for both record definitions and ObjC interface declarations.
void ActOnFields(Scope *S, SourceLocation RecLoc, Decl *TagDecl,
                 ArrayRef<Decl *> Fields, SourceLocation LBrac,
                 SourceLocation RBrac, const ParsedAttributesView &AttrList);

/// ActOnTagStartDefinition - Invoked when we have entered the
/// scope of a tag's definition (e.g., for an enumeration, class,
/// struct, or union).
void ActOnTagStartDefinition(Scope *S, Decl *TagDecl);

/// Perform ODR-like check for C/ObjC when merging tag types from modules.
/// Differently from C++, actually parse the body and reject / error out
/// in case of a structural mismatch.
bool ActOnDuplicateDefinition(DeclSpec &DS, Decl *Prev,
                              SkipBodyInfo &SkipBody);

typedef void *SkippedDefinitionContext;

/// Invoked when we enter a tag definition that we're skipping.
SkippedDefinitionContext ActOnTagStartSkippedDefinition(Scope *S, Decl *TD);

Decl *ActOnObjCContainerStartDefinition(Decl *IDecl);

/// ActOnStartCXXMemberDeclarations - Invoked when we have parsed a
/// C++ record definition's base-specifiers clause and are starting its
/// member declarations.
void ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagDecl,
                                     SourceLocation FinalLoc,
                                     bool IsFinalSpelledSealed,
                                     bool IsAbstract,
                                     SourceLocation LBraceLoc);

/// ActOnTagFinishDefinition - Invoked once we have finished parsing
/// the definition of a tag (enumeration, class, struct, or union).
void ActOnTagFinishDefinition(Scope *S, Decl *TagDecl,
                              SourceRange BraceRange);

void ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context);

void ActOnObjCContainerFinishDefinition();

/// Invoked when we must temporarily exit the objective-c container
/// scope for parsing/looking-up C constructs.
///
/// Must be followed by a call to \see ActOnObjCReenterContainerContext
void ActOnObjCTemporaryExitContainerContext(DeclContext *DC);
void ActOnObjCReenterContainerContext(DeclContext *DC);

/// ActOnTagDefinitionError - Invoked when there was an unrecoverable
/// error parsing the definition of a tag.
void ActOnTagDefinitionError(Scope *S, Decl *TagDecl);

EnumConstantDecl *CheckEnumConstant(EnumDecl *Enum,
                                    EnumConstantDecl *LastEnumConst,
                                    SourceLocation IdLoc,
                                    IdentifierInfo *Id,
                                    Expr *val);
bool CheckEnumUnderlyingType(TypeSourceInfo *TI);
bool CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
                            QualType EnumUnderlyingTy, bool IsFixed,
                            const EnumDecl *Prev);

/// Determine whether the body of an anonymous enumeration should be skipped.
/// \param II The name of the first enumerator.
SkipBodyInfo shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
                                    SourceLocation IILoc);

Decl *ActOnEnumConstant(Scope *S, Decl *EnumDecl, Decl *LastEnumConstant,
                        SourceLocation IdLoc, IdentifierInfo *Id,
                        const ParsedAttributesView &Attrs,
                        SourceLocation EqualLoc, Expr *Val);
void ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
                   Decl *EnumDecl, ArrayRef<Decl *> Elements, Scope *S,
                   const ParsedAttributesView &Attr);

/// Set the current declaration context until it gets popped.
void PushDeclContext(Scope *S, DeclContext *DC);
void PopDeclContext();

/// EnterDeclaratorContext - Used when we must lookup names in the context
/// of a declarator's nested name specifier.
void EnterDeclaratorContext(Scope *S, DeclContext *DC);
void ExitDeclaratorContext(Scope *S);

/// Enter a template parameter scope, after it's been associated with a particular
/// DeclContext. Causes lookup within the scope to chain through enclosing contexts
/// in the correct order.
void EnterTemplatedContext(Scope *S, DeclContext *DC);

/// Push the parameters of D, which must be a function, into scope.
void ActOnReenterFunctionContext(Scope* S, Decl* D);
void ActOnExitFunctionContext();

DeclContext *getFunctionLevelDeclContext();

/// getCurFunctionDecl - If inside of a function body, this returns a pointer
/// to the function decl for the function being parsed.  If we're currently
/// in a 'block', this returns the containing context.
FunctionDecl *getCurFunctionDecl();

/// getCurMethodDecl - If inside of a method body, this returns a pointer to
/// the method decl for the method being parsed.  If we're currently
/// in a 'block', this returns the containing context.
ObjCMethodDecl *getCurMethodDecl();

/// getCurFunctionOrMethodDecl - Return the Decl for the current ObjC method
/// or C function we're in, otherwise return null.  If we're currently
/// in a 'block', this returns the containing context.
NamedDecl *getCurFunctionOrMethodDecl();

/// Add this decl to the scope shadowed decl chains.
void PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext = true);

/// isDeclInScope - If 'Ctx' is a function/method, isDeclInScope returns true
/// if 'D' is in Scope 'S', otherwise 'S' is ignored and isDeclInScope returns
/// true if 'D' belongs to the given declaration context.
///
/// \param AllowInlineNamespace If \c true, allow the declaration to be in the
///        enclosing namespace set of the context, rather than contained
///        directly within it.
bool isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S = nullptr,
                   bool AllowInlineNamespace = false);

/// Finds the scope corresponding to the given decl context, if it
/// happens to be an enclosing scope.  Otherwise return NULL.
static Scope *getScopeForDeclContext(Scope *S, DeclContext *DC);

/// Subroutines of ActOnDeclarator().
TypedefDecl *ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
                              TypeSourceInfo *TInfo);
bool isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New);

/// Describes the kind of merge to perform for availability
/// attributes (including "deprecated", "unavailable", and "availability").
enum AvailabilityMergeKind {
  /// Don't merge availability attributes at all.
  AMK_None,
  /// Merge availability attributes for a redeclaration, which requires
  /// an exact match.
  AMK_Redeclaration,
  /// Merge availability attributes for an override, which requires
  /// an exact match or a weakening of constraints.
  AMK_Override,
  /// Merge availability attributes for an implementation of
  /// a protocol requirement.
  AMK_ProtocolImplementation,
  /// Merge availability attributes for an implementation of
  /// an optional protocol requirement.
  AMK_OptionalProtocolImplementation
};

/// Describes the kind of priority given to an availability attribute.
///
/// The sum of priorities deteremines the final priority of the attribute.
/// The final priority determines how the attribute will be merged.
/// An attribute with a lower priority will always remove higher priority
/// attributes for the specified platform when it is being applied. An
/// attribute with a higher priority will not be applied if the declaration
/// already has an availability attribute with a lower priority for the
/// specified platform. The final prirority values are not expected to match
/// the values in this enumeration, but instead should be treated as a plain
/// integer value. This enumeration just names the priority weights that are
/// used to calculate that final vaue.
enum AvailabilityPriority : int {
  /// The availability attribute was specified explicitly next to the
  /// declaration.
  AP_Explicit = 0,

  /// The availability attribute was applied using '#pragma clang attribute'.
  AP_PragmaClangAttribute = 1,

  /// The availability attribute for a specific platform was inferred from
  /// an availability attribute for another platform.
  AP_InferredFromOtherPlatform = 2
};

/// Attribute merging methods. Return true if a new attribute was added.
AvailabilityAttr *
mergeAvailabilityAttr(NamedDecl *D, const AttributeCommonInfo &CI,
                      IdentifierInfo *Platform, bool Implicit,
                      VersionTuple Introduced, VersionTuple Deprecated,
                      VersionTuple Obsoleted, bool IsUnavailable,
                      StringRef Message, bool IsStrict, StringRef Replacement,
                      AvailabilityMergeKind AMK, int Priority);
TypeVisibilityAttr *
mergeTypeVisibilityAttr(Decl *D, const AttributeCommonInfo &CI,
                        TypeVisibilityAttr::VisibilityType Vis);
VisibilityAttr *mergeVisibilityAttr(Decl *D, const AttributeCommonInfo &CI,
                                    VisibilityAttr::VisibilityType Vis);
UuidAttr *mergeUuidAttr(Decl *D, const AttributeCommonInfo &CI,
                        StringRef UuidAsWritten, MSGuidDecl *GuidDecl);
DLLImportAttr *mergeDLLImportAttr(Decl *D, const AttributeCommonInfo &CI);
DLLExportAttr *mergeDLLExportAttr(Decl *D, const AttributeCommonInfo &CI);
MSInheritanceAttr *mergeMSInheritanceAttr(Decl *D,
                                          const AttributeCommonInfo &CI,
                                          bool BestCase,
                                          MSInheritanceModel Model);
FormatAttr *mergeFormatAttr(Decl *D, const AttributeCommonInfo &CI,
                            IdentifierInfo *Format, int FormatIdx,
                            int FirstArg);
SectionAttr *mergeSectionAttr(Decl *D, const AttributeCommonInfo &CI,
                              StringRef Name);
CodeSegAttr *mergeCodeSegAttr(Decl *D, const AttributeCommonInfo &CI,
                              StringRef Name);
AlwaysInlineAttr *mergeAlwaysInlineAttr(Decl *D,
                                        const AttributeCommonInfo &CI,
                                        const IdentifierInfo *Ident);
MinSizeAttr *mergeMinSizeAttr(Decl *D, const AttributeCommonInfo &CI);
SwiftNameAttr *mergeSwiftNameAttr(Decl *D, const SwiftNameAttr &SNA,
                                  StringRef Name);
OptimizeNoneAttr *mergeOptimizeNoneAttr(Decl *D,
                                        const AttributeCommonInfo &CI);
InternalLinkageAttr *mergeInternalLinkageAttr(Decl *D, const ParsedAttr &AL);
InternalLinkageAttr *mergeInternalLinkageAttr(Decl *D,
                                              const InternalLinkageAttr &AL);
WebAssemblyImportNameAttr *mergeImportNameAttr(
    Decl *D, const WebAssemblyImportNameAttr &AL);
WebAssemblyImportModuleAttr *mergeImportModuleAttr(
    Decl *D, const WebAssemblyImportModuleAttr &AL);
EnforceTCBAttr *mergeEnforceTCBAttr(Decl *D, const EnforceTCBAttr &AL);
EnforceTCBLeafAttr *mergeEnforceTCBLeafAttr(Decl *D,
                                            const EnforceTCBLeafAttr &AL);

void mergeDeclAttributes(NamedDecl *New, Decl *Old,
                         AvailabilityMergeKind AMK = AMK_Redeclaration);
void MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
                          LookupResult &OldDecls);
bool MergeFunctionDecl(FunctionDecl *New, NamedDecl *&Old, Scope *S,
                       bool MergeTypeWithOld);
bool MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
                                  Scope *S, bool MergeTypeWithOld);
void mergeObjCMethodDecls(ObjCMethodDecl *New, ObjCMethodDecl *Old);
void MergeVarDecl(VarDecl *New, LookupResult &Previous);
void MergeVarDeclTypes(VarDecl *New, VarDecl *Old, bool MergeTypeWithOld);
void MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old);
bool checkVarDeclRedefinition(VarDecl *OldDefn, VarDecl *NewDefn);
void notePreviousDefinition(const NamedDecl *Old, SourceLocation New);
bool MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old, Scope *S);

// AssignmentAction - This is used by all the assignment diagnostic functions
// to represent what is actually causing the operation
enum AssignmentAction {
  AA_Assigning,
  AA_Passing,
  AA_Returning,
  AA_Converting,
  AA_Initializing,
  AA_Sending,
  AA_Casting,
  AA_Passing_CFAudited
};

/// C++ Overloading.
enum OverloadKind {
  /// This is a legitimate overload: the existing declarations are
  /// functions or function templates with different signatures.
  Ovl_Overload,

  /// This is not an overload because the signature exactly matches
  /// an existing declaration.
  Ovl_Match,

  /// This is not an overload because the lookup results contain a
  /// non-function.
  Ovl_NonFunction
};
OverloadKind CheckOverload(Scope *S,
                           FunctionDecl *New,
                           const LookupResult &OldDecls,
                           NamedDecl *&OldDecl,
                           bool IsForUsingDecl);
bool IsOverload(FunctionDecl *New, FunctionDecl *Old, bool IsForUsingDecl,
                bool ConsiderCudaAttrs = true,
                bool ConsiderRequiresClauses = true);

enum class AllowedExplicit {
  /// Allow no explicit functions to be used.
  None,
  /// Allow explicit conversion functions but not explicit constructors.
  Conversions,
  /// Allow both explicit conversion functions and explicit constructors.
  All
};

ImplicitConversionSequence
TryImplicitConversion(Expr *From, QualType ToType,
                      bool SuppressUserConversions,
                      AllowedExplicit AllowExplicit,
                      bool InOverloadResolution,
                      bool CStyle,
                      bool AllowObjCWritebackConversion);

bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);
bool IsFloatingPointPromotion(QualType FromType, QualType ToType);
bool IsComplexPromotion(QualType FromType, QualType ToType);
bool IsPointerConversion(Expr *From, QualType FromType, QualType ToType,
                         bool InOverloadResolution,
                         QualType& ConvertedType, bool &IncompatibleObjC);
bool isObjCPointerConversion(QualType FromType, QualType ToType,
                             QualType& ConvertedType, bool &IncompatibleObjC);
bool isObjCWritebackConversion(QualType FromType, QualType ToType,
                               QualType &ConvertedType);
bool IsBlockPointerConversion(QualType FromType, QualType ToType,
                              QualType& ConvertedType);
bool FunctionParamTypesAreEqual(const FunctionProtoType *OldType,
                                const FunctionProtoType *NewType,
                                unsigned *ArgPos = nullptr);
void HandleFunctionTypeMismatch(PartialDiagnostic &PDiag,
                                QualType FromType, QualType ToType);

void maybeExtendBlockObject(ExprResult &E);
CastKind PrepareCastToObjCObjectPointer(ExprResult &E);
bool CheckPointerConversion(Expr *From, QualType ToType,
                            CastKind &Kind,
                            CXXCastPath& BasePath,
                            bool IgnoreBaseAccess,
                            bool Diagnose = true);
bool IsMemberPointerConversion(Expr *From, QualType FromType, QualType ToType,
                               bool InOverloadResolution,
                               QualType &ConvertedType);
bool CheckMemberPointerConversion(Expr *From, QualType ToType,
                                  CastKind &Kind,
                                  CXXCastPath &BasePath,
                                  bool IgnoreBaseAccess);
bool IsQualificationConversion(QualType FromType, QualType ToType,
                               bool CStyle, bool &ObjCLifetimeConversion);
bool IsFunctionConversion(QualType FromType, QualType ToType,
                          QualType &ResultTy);
bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType);
bool isSameOrCompatibleFunctionType(CanQualType Param, CanQualType Arg);

bool CanPerformAggregateInitializationForOverloadResolution(
    const InitializedEntity &Entity, InitListExpr *From);

bool IsStringInit(Expr *Init, const ArrayType *AT);

bool CanPerformCopyInitialization(const InitializedEntity &Entity,
                                  ExprResult Init);
ExprResult PerformCopyInitialization(const InitializedEntity &Entity,
                                     SourceLocation EqualLoc,
                                     ExprResult Init,
                                     bool TopLevelOfInitList = false,
                                     bool AllowExplicit = false);
ExprResult PerformObjectArgumentInitialization(Expr *From,
                                               NestedNameSpecifier *Qualifier,
                                               NamedDecl *FoundDecl,
                                               CXXMethodDecl *Method);

/// Check that the lifetime of the initializer (and its subobjects) is
/// sufficient for initializing the entity, and perform lifetime extension
/// (when permitted) if not.
void checkInitializerLifetime(const InitializedEntity &Entity, Expr *Init);

ExprResult PerformContextuallyConvertToBool(Expr *From);
ExprResult PerformContextuallyConvertToObjCPointer(Expr *From);

/// Contexts in which a converted constant expression is required.
enum CCEKind {
  CCEK_CaseValue,   ///< Expression in a case label.
  CCEK_Enumerator,  ///< Enumerator value with fixed underlying type.
  CCEK_TemplateArg, ///< Value of a non-type template parameter.
  CCEK_ArrayBound,  ///< Array bound in array declarator or new-expression.
  CCEK_ExplicitBool ///< Condition in an explicit(bool) specifier.
};
ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
                                            llvm::APSInt &Value, CCEKind CCE);
ExprResult CheckConvertedConstantExpression(Expr *From, QualType T,
                                            APValue &Value, CCEKind CCE,
                                            NamedDecl *Dest = nullptr);

/// Abstract base class used to perform a contextual implicit
/// conversion from an expression to any type passing a filter.
class ContextualImplicitConverter {
public:
  bool Suppress;
  bool SuppressConversion;

  ContextualImplicitConverter(bool Suppress = false,
                              bool SuppressConversion = false)
      : Suppress(Suppress), SuppressConversion(SuppressConversion) {}

  /// Determine whether the specified type is a valid destination type
  /// for this conversion.
  virtual bool match(QualType T) = 0;

  /// Emits a diagnostic complaining that the expression does not have
  /// integral or enumeration type.
  virtual SemaDiagnosticBuilder
  diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a diagnostic when the expression has incomplete class type.
  virtual SemaDiagnosticBuilder
  diagnoseIncomplete(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a diagnostic when the only matching conversion function
  /// is explicit.
  virtual SemaDiagnosticBuilder diagnoseExplicitConv(
      Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;

  /// Emits a note for the explicit conversion function.
  virtual SemaDiagnosticBuilder
  noteExplicitConv(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;

  /// Emits a diagnostic when there are multiple possible conversion
  /// functions.
  virtual SemaDiagnosticBuilder
  diagnoseAmbiguous(Sema &S, SourceLocation Loc, QualType T) = 0;

  /// Emits a note for one of the candidate conversions.
  virtual SemaDiagnosticBuilder
  noteAmbiguous(Sema &S, CXXConversionDecl *Conv, QualType ConvTy) = 0;

  /// Emits a diagnostic when we picked a conversion function
  /// (for cases when we are not allowed to pick a conversion function).
  virtual SemaDiagnosticBuilder diagnoseConversion(
      Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) = 0;

  virtual ~ContextualImplicitConverter() {}
};

class ICEConvertDiagnoser : public ContextualImplicitConverter {
  bool AllowScopedEnumerations;

public:
  ICEConvertDiagnoser(bool AllowScopedEnumerations,
                      bool Suppress, bool SuppressConversion)
      : ContextualImplicitConverter(Suppress, SuppressConversion),
        AllowScopedEnumerations(AllowScopedEnumerations) {}

  /// Match an integral or (possibly scoped) enumeration type.
  bool match(QualType T) override;

  SemaDiagnosticBuilder
  diagnoseNoMatch(Sema &S, SourceLocation Loc, QualType T) override {
    return diagnoseNotInt(S, Loc, T);
  }

  /// Emits a diagnostic complaining that the expression does not have
  /// integral or enumeration type.
  virtual SemaDiagnosticBuilder
  diagnoseNotInt(Sema &S, SourceLocation Loc, QualType T) = 0;
};

/// Perform a contextual implicit conversion.
ExprResult PerformContextualImplicitConversion(
    SourceLocation Loc, Expr *FromE, ContextualImplicitConverter &Converter);


enum ObjCSubscriptKind {
  OS_Array,
  OS_Dictionary,
  OS_Error
};
ObjCSubscriptKind CheckSubscriptingKind(Expr *FromE);

// Note that LK_String is intentionally after the other literals, as
// this is used for diagnostics logic.
enum ObjCLiteralKind {
  LK_Array,
  LK_Dictionary,
  LK_Numeric,
  LK_Boxed,
  LK_String,
  LK_Block,
  LK_None
};
ObjCLiteralKind CheckLiteralKind(Expr *FromE);

ExprResult PerformObjectMemberConversion(Expr *From,
                                         NestedNameSpecifier *Qualifier,
                                         NamedDecl *FoundDecl,
                                         NamedDecl *Member);

// Members have to be NamespaceDecl* or TranslationUnitDecl*.
// TODO: make this is a typesafe union.
typedef llvm::SmallSetVector<DeclContext   *, 16> AssociatedNamespaceSet;
typedef llvm::SmallSetVector<CXXRecordDecl *, 16> AssociatedClassSet;

using ADLCallKind = CallExpr::ADLCallKind;

void AddOverloadCandidate(FunctionDecl *Function, DeclAccessPair FoundDecl,
                          ArrayRef<Expr *> Args,
                          OverloadCandidateSet &CandidateSet,
                          bool SuppressUserConversions = false,
                          bool PartialOverloading = false,
                          bool AllowExplicit = true,
                          bool AllowExplicitConversion = false,
                          ADLCallKind IsADLCandidate = ADLCallKind::NotADL,
                          ConversionSequenceList EarlyConversions = None,
                          OverloadCandidateParamOrder PO = {});
void AddFunctionCandidates(const UnresolvedSetImpl &Functions,
                    ArrayRef<Expr *> Args,
                    OverloadCandidateSet &CandidateSet,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
                    bool SuppressUserConversions = false,
                    bool PartialOverloading = false,
                    bool FirstArgumentIsBase = false);
void AddMethodCandidate(DeclAccessPair FoundDecl,
                        QualType ObjectType,
                        Expr::Classification ObjectClassification,
                        ArrayRef<Expr *> Args,
                        OverloadCandidateSet& CandidateSet,
                        bool SuppressUserConversion = false,
                        OverloadCandidateParamOrder PO = {});
void AddMethodCandidate(CXXMethodDecl *Method,
                        DeclAccessPair FoundDecl,
                        CXXRecordDecl *ActingContext, QualType ObjectType,
                        Expr::Classification ObjectClassification,
                        ArrayRef<Expr *> Args,
                        OverloadCandidateSet& CandidateSet,
                        bool SuppressUserConversions = false,
                        bool PartialOverloading = false,
                        ConversionSequenceList EarlyConversions = None,
                        OverloadCandidateParamOrder PO = {});
void AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl,
                                DeclAccessPair FoundDecl,
                                CXXRecordDecl *ActingContext,
                               TemplateArgumentListInfo *ExplicitTemplateArgs,
                                QualType ObjectType,
                                Expr::Classification ObjectClassification,
                                ArrayRef<Expr *> Args,
                                OverloadCandidateSet& CandidateSet,
                                bool SuppressUserConversions = false,
                                bool PartialOverloading = false,
                                OverloadCandidateParamOrder PO = {});
void AddTemplateOverloadCandidate(
    FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
    TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
    OverloadCandidateSet &CandidateSet, bool SuppressUserConversions = false,
    bool PartialOverloading = false, bool AllowExplicit = true,
    ADLCallKind IsADLCandidate = ADLCallKind::NotADL,
    OverloadCandidateParamOrder PO = {});
bool CheckNonDependentConversions(
    FunctionTemplateDecl *FunctionTemplate, ArrayRef<QualType> ParamTypes,
    ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet,
    ConversionSequenceList &Conversions, bool SuppressUserConversions,
    CXXRecordDecl *ActingContext = nullptr, QualType ObjectType = QualType(),
    Expr::Classification ObjectClassification = {},
    OverloadCandidateParamOrder PO = {});
void AddConversionCandidate(
    CXXConversionDecl *Conversion, DeclAccessPair FoundDecl,
    CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
    OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
    bool AllowExplicit, bool AllowResultConversion = true);
void AddTemplateConversionCandidate(
    FunctionTemplateDecl *FunctionTemplate, DeclAccessPair FoundDecl,
    CXXRecordDecl *ActingContext, Expr *From, QualType ToType,
    OverloadCandidateSet &CandidateSet, bool AllowObjCConversionOnExplicit,
    bool AllowExplicit, bool AllowResultConversion = true);
void AddSurrogateCandidate(CXXConversionDecl *Conversion,
                           DeclAccessPair FoundDecl,
                           CXXRecordDecl *ActingContext,
                           const FunctionProtoType *Proto,
                           Expr *Object, ArrayRef<Expr *> Args,
                           OverloadCandidateSet& CandidateSet);
void AddNonMemberOperatorCandidates(
    const UnresolvedSetImpl &Functions, ArrayRef<Expr *> Args,
    OverloadCandidateSet &CandidateSet,
    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);
void AddMemberOperatorCandidates(OverloadedOperatorKind Op,
                                 SourceLocation OpLoc, ArrayRef<Expr *> Args,
                                 OverloadCandidateSet &CandidateSet,
                                 OverloadCandidateParamOrder PO = {});
void AddBuiltinCandidate(QualType *ParamTys, ArrayRef<Expr *> Args,
                         OverloadCandidateSet& CandidateSet,
                         bool IsAssignmentOperator = false,
                         unsigned NumContextualBoolArguments = 0);
void AddBuiltinOperatorCandidates(OverloadedOperatorKind Op,
                                  SourceLocation OpLoc, ArrayRef<Expr *> Args,
                                  OverloadCandidateSet& CandidateSet);
void AddArgumentDependentLookupCandidates(DeclarationName Name,
                                          SourceLocation Loc,
                                          ArrayRef<Expr *> Args,
                              TemplateArgumentListInfo *ExplicitTemplateArgs,
                                          OverloadCandidateSet& CandidateSet,
                                          bool PartialOverloading = false);

// Emit as a 'note' the specific overload candidate
void NoteOverloadCandidate(
    NamedDecl *Found, FunctionDecl *Fn,
    OverloadCandidateRewriteKind RewriteKind = OverloadCandidateRewriteKind(),
    QualType DestType = QualType(), bool TakingAddress = false);

// Emit as a series of 'note's all template and non-templates identified by
// the expression Expr
void NoteAllOverloadCandidates(Expr *E, QualType DestType = QualType(),
                               bool TakingAddress = false);

/// Check the enable_if expressions on the given function. Returns the first
/// failing attribute, or NULL if they were all successful.
EnableIfAttr *CheckEnableIf(FunctionDecl *Function, SourceLocation CallLoc,
                            ArrayRef<Expr *> Args,
                            bool MissingImplicitThis = false);

/// Find the failed Boolean condition within a given Boolean
/// constant expression, and describe it with a string.
std::pair<Expr *, std::string> findFailedBooleanCondition(Expr *Cond);

/// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
/// non-ArgDependent DiagnoseIfAttrs.
///
/// Argument-dependent diagnose_if attributes should be checked each time a
/// function is used as a direct callee of a function call.
///
/// Returns true if any errors were emitted.
bool diagnoseArgDependentDiagnoseIfAttrs(const FunctionDecl *Function,
                                         const Expr *ThisArg,
                                         ArrayRef<const Expr *> Args,
                                         SourceLocation Loc);

/// Emit diagnostics for the diagnose_if attributes on Function, ignoring any
/// ArgDependent DiagnoseIfAttrs.
///
/// Argument-independent diagnose_if attributes should be checked on every use
/// of a function.
///
/// Returns true if any errors were emitted.
bool diagnoseArgIndependentDiagnoseIfAttrs(const NamedDecl *ND,
                                           SourceLocation Loc);

/// Returns whether the given function's address can be taken or not,
/// optionally emitting a diagnostic if the address can't be taken.
///
/// Returns false if taking the address of the function is illegal.
bool checkAddressOfFunctionIsAvailable(const FunctionDecl *Function,
                                       bool Complain = false,
                                       SourceLocation Loc = SourceLocation());

// [PossiblyAFunctionType]  -->   [Return]
// NonFunctionType --> NonFunctionType
// R (A) --> R(A)
// R (*)(A) --> R (A)
// R (&)(A) --> R (A)
// R (S::*)(A) --> R (A)
QualType ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType);

FunctionDecl *
ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr,
                                   QualType TargetType,
                                   bool Complain,
                                   DeclAccessPair &Found,
                                   bool *pHadMultipleCandidates = nullptr);

FunctionDecl *
resolveAddressOfSingleOverloadCandidate(Expr *E, DeclAccessPair &FoundResult);

bool resolveAndFixAddressOfSingleOverloadCandidate(
    ExprResult &SrcExpr, bool DoFunctionPointerConversion = false);

FunctionDecl *
ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl,
                                            bool Complain = false,
                                            DeclAccessPair *Found = nullptr);

bool ResolveAndFixSingleFunctionTemplateSpecialization(
                    ExprResult &SrcExpr,
                    bool DoFunctionPointerConverion = false,
                    bool Complain = false,
                    SourceRange OpRangeForComplaining = SourceRange(),
                    QualType DestTypeForComplaining = QualType(),
                    unsigned DiagIDForComplaining = 0);


Expr *FixOverloadedFunctionReference(Expr *E,
                                     DeclAccessPair FoundDecl,
                                     FunctionDecl *Fn);
ExprResult FixOverloadedFunctionReference(ExprResult,
                                          DeclAccessPair FoundDecl,
                                          FunctionDecl *Fn);

void AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE,
                                 ArrayRef<Expr *> Args,
                                 OverloadCandidateSet &CandidateSet,
                                 bool PartialOverloading = false);
void AddOverloadedCallCandidates(
    LookupResult &R, TemplateArgumentListInfo *ExplicitTemplateArgs,
    ArrayRef<Expr *> Args, OverloadCandidateSet &CandidateSet);

// An enum used to represent the different possible results of building a
// range-based for loop.
enum ForRangeStatus {
  FRS_Success,
  FRS_NoViableFunction,
  FRS_DiagnosticIssued
};

ForRangeStatus BuildForRangeBeginEndCall(SourceLocation Loc,
                                         SourceLocation RangeLoc,
                                         const DeclarationNameInfo &NameInfo,
                                         LookupResult &MemberLookup,
                                         OverloadCandidateSet *CandidateSet,
                                         Expr *Range, ExprResult *CallExpr);

ExprResult BuildOverloadedCallExpr(Scope *S, Expr *Fn,
                                   UnresolvedLookupExpr *ULE,
                                   SourceLocation LParenLoc,
                                   MultiExprArg Args,
                                   SourceLocation RParenLoc,
                                   Expr *ExecConfig,
                                   bool AllowTypoCorrection=true,
                                   bool CalleesAddressIsTaken=false);

bool buildOverloadedCallSet(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE,
                            MultiExprArg Args, SourceLocation RParenLoc,
                            OverloadCandidateSet *CandidateSet,
                            ExprResult *Result);

ExprResult CreateUnresolvedLookupExpr(CXXRecordDecl *NamingClass,
                                      NestedNameSpecifierLoc NNSLoc,
                                      DeclarationNameInfo DNI,
                                      const UnresolvedSetImpl &Fns,
                                      bool PerformADL = true);

ExprResult CreateOverloadedUnaryOp(SourceLocation OpLoc,
                                   UnaryOperatorKind Opc,
                                   const UnresolvedSetImpl &Fns,
                                   Expr *input, bool RequiresADL = true);

void LookupOverloadedBinOp(OverloadCandidateSet &CandidateSet,
                           OverloadedOperatorKind Op,
                           const UnresolvedSetImpl &Fns,
                           ArrayRef<Expr *> Args, bool RequiresADL = true);
ExprResult CreateOverloadedBinOp(SourceLocation OpLoc,
                                 BinaryOperatorKind Opc,
                                 const UnresolvedSetImpl &Fns,
                                 Expr *LHS, Expr *RHS,
                                 bool RequiresADL = true,
                                 bool AllowRewrittenCandidates = true,
                                 FunctionDecl *DefaultedFn = nullptr);
ExprResult BuildSynthesizedThreeWayComparison(SourceLocation OpLoc,
                                              const UnresolvedSetImpl &Fns,
                                              Expr *LHS, Expr *RHS,
                                              FunctionDecl *DefaultedFn);

ExprResult CreateOverloadedArraySubscriptExpr(SourceLocation LLoc,
                                              SourceLocation RLoc,
                                              Expr *Base,Expr *Idx);

ExprResult BuildCallToMemberFunction(Scope *S, Expr *MemExpr,
                                     SourceLocation LParenLoc,
                                     MultiExprArg Args,
                                     SourceLocation RParenLoc,
                                     bool AllowRecovery = false);
ExprResult
BuildCallToObjectOfClassType(Scope *S, Expr *Object, SourceLocation LParenLoc,
                             MultiExprArg Args,
                             SourceLocation RParenLoc);

ExprResult BuildOverloadedArrowExpr(Scope *S, Expr *Base,
                                    SourceLocation OpLoc,
                                    bool *NoArrowOperatorFound = nullptr);

/// CheckCallReturnType - Checks that a call expression's return type is
/// complete. Returns true on failure. The location passed in is the location
/// that best represents the call.
bool CheckCallReturnType(QualType ReturnType, SourceLocation Loc,
                         CallExpr *CE, FunctionDecl *FD);

/// Helpers for dealing with blocks and functions.
bool CheckParmsForFunctionDef(ArrayRef<ParmVarDecl *> Parameters,
                              bool CheckParameterNames);
void CheckCXXDefaultArguments(FunctionDecl *FD);
void CheckExtraCXXDefaultArguments(Declarator &D);
Scope *getNonFieldDeclScope(Scope *S);

/// \name Name lookup
///
/// These routines provide name lookup that is used during semantic
/// analysis to resolve the various kinds of names (identifiers,
/// overloaded operator names, constructor names, etc.) into zero or
/// more declarations within a particular scope. The major entry
/// points are LookupName, which performs unqualified name lookup,
/// and LookupQualifiedName, which performs qualified name lookup.
///
/// All name lookup is performed based on some specific criteria,
/// which specify what names will be visible to name lookup and how
/// far name lookup should work. These criteria are important both
/// for capturing language semantics (certain lookups will ignore
/// certain names, for example) and for performance, since name
/// lookup is often a bottleneck in the compilation of C++. Name
/// lookup criteria is specified via the LookupCriteria enumeration.
///
/// The results of name lookup can vary based on the kind of name
/// lookup performed, the current language, and the translation
/// unit. In C, for example, name lookup will either return nothing
/// (no entity found) or a single declaration. In C++, name lookup
/// can additionally refer to a set of overloaded functions or
/// result in an ambiguity. All of the possible results of name
/// lookup are captured by the LookupResult class, which provides
/// the ability to distinguish among them.
//@{

/// Describes the kind of name lookup to perform.
enum LookupNameKind {
  /// Ordinary name lookup, which finds ordinary names (functions,
  /// variables, typedefs, etc.) in C and most kinds of names
  /// (functions, variables, members, types, etc.) in C++.
  LookupOrdinaryName = 0,
  /// Tag name lookup, which finds the names of enums, classes,
  /// structs, and unions.
  LookupTagName,
  /// Label name lookup.
  LookupLabel,
  /// Member name lookup, which finds the names of
  /// class/struct/union members.
  LookupMemberName,
  /// Look up of an operator name (e.g., operator+) for use with
  /// operator overloading. This lookup is similar to ordinary name
  /// lookup, but will ignore any declarations that are class members.
  LookupOperatorName,
  /// Look up a name following ~ in a destructor name. This is an ordinary
  /// lookup, but prefers tags to typedefs.
  LookupDestructorName,
  /// Look up of a name that precedes the '::' scope resolution
  /// operator in C++. This lookup completely ignores operator, object,
  /// function, and enumerator names (C++ [basic.lookup.qual]p1).
  LookupNestedNameSpecifierName,
  /// Look up a namespace name within a C++ using directive or
  /// namespace alias definition, ignoring non-namespace names (C++
  /// [basic.lookup.udir]p1).
  LookupNamespaceName,
  /// Look up all declarations in a scope with the given name,
  /// including resolved using declarations.  This is appropriate
  /// for checking redeclarations for a using declaration.
  LookupUsingDeclName,
  /// Look up an ordinary name that is going to be redeclared as a
  /// name with linkage. This lookup ignores any declarations that
  /// are outside of the current scope unless they have linkage. See
  /// C99 6.2.2p4-5 and C++ [basic.link]p6.
  LookupRedeclarationWithLinkage,
  /// Look up a friend of a local class. This lookup does not look
  /// outside the innermost non-class scope. See C++11 [class.friend]p11.
  LookupLocalFriendName,
  /// Look up the name of an Objective-C protocol.
  LookupObjCProtocolName,
  /// Look up implicit 'self' parameter of an objective-c method.
  LookupObjCImplicitSelfParam,
  /// Look up the name of an OpenMP user-defined reduction operation.
  LookupOMPReductionName,
  /// Look up the name of an OpenMP user-defined mapper.
  LookupOMPMapperName,
  /// Look up any declaration with any name.
  LookupAnyName
};

/// Specifies whether (or how) name lookup is being performed for a
/// redeclaration (vs. a reference).
enum RedeclarationKind {
  /// The lookup is a reference to this name that is not for the
  /// purpose of redeclaring the name.
  NotForRedeclaration = 0,
  /// The lookup results will be used for redeclaration of a name,
  /// if an entity by that name already exists and is visible.
  ForVisibleRedeclaration,
  /// The lookup results will be used for redeclaration of a name
  /// with external linkage; non-visible lookup results with external linkage
  /// may also be found.
  ForExternalRedeclaration
};

RedeclarationKind forRedeclarationInCurContext() {
  // A declaration with an owning module for linkage can never link against
  // anything that is not visible. We don't need to check linkage here; if
  // the context has internal linkage, redeclaration lookup won't find things
  // from other TUs, and we can't safely compute linkage yet in general.
  if (cast<Decl>(CurContext)
          ->getOwningModuleForLinkage(/*IgnoreLinkage*/true))
    return ForVisibleRedeclaration;
  return ForExternalRedeclaration;
}

/// The possible outcomes of name lookup for a literal operator.
enum LiteralOperatorLookupResult {
  /// The lookup resulted in an error.
  LOLR_Error,
  /// The lookup found no match but no diagnostic was issued.
  LOLR_ErrorNoDiagnostic,
  /// The lookup found a single 'cooked' literal operator, which
  /// expects a normal literal to be built and passed to it.
  LOLR_Cooked,
  /// The lookup found a single 'raw' literal operator, which expects
  /// a string literal containing the spelling of the literal token.
  LOLR_Raw,
  /// The lookup found an overload set of literal operator templates,
  /// which expect the characters of the spelling of the literal token to be
  /// passed as a non-type template argument pack.
  LOLR_Template,
  /// The lookup found an overload set of literal operator templates,
  /// which expect the character type and characters of the spelling of the
  /// string literal token to be passed as template arguments.
  LOLR_StringTemplatePack,
};

SpecialMemberOverloadResult LookupSpecialMember(CXXRecordDecl *D,
                                                CXXSpecialMember SM,
                                                bool ConstArg,
                                                bool VolatileArg,
                                                bool RValueThis,
                                                bool ConstThis,
                                                bool VolatileThis);

typedef std::function<void(const TypoCorrection &)> TypoDiagnosticGenerator;
typedef std::function<ExprResult(Sema &, TypoExpr *, TypoCorrection)>
    TypoRecoveryCallback;

4054private:
bool CppLookupName(LookupResult &R, Scope *S);

struct TypoExprState {
  std::unique_ptr<TypoCorrectionConsumer> Consumer;
  TypoDiagnosticGenerator DiagHandler;
  TypoRecoveryCallback RecoveryHandler;
  TypoExprState();
  TypoExprState(TypoExprState &&other) noexcept;
  TypoExprState &operator=(TypoExprState &&other) noexcept;
};

/// The set of unhandled TypoExprs and their associated state.
llvm::MapVector<TypoExpr *, TypoExprState> DelayedTypos;

/// Creates a new TypoExpr AST node.
TypoExpr *createDelayedTypo(std::unique_ptr<TypoCorrectionConsumer> TCC,
                            TypoDiagnosticGenerator TDG,
                            TypoRecoveryCallback TRC, SourceLocation TypoLoc);

// The set of known/encountered (unique, canonicalized) NamespaceDecls.
//
// The boolean value will be true to indicate that the namespace was loaded
// from an AST/PCH file, or false otherwise.
llvm::MapVector<NamespaceDecl*, bool> KnownNamespaces;

/// Whether we have already loaded known namespaces from an extenal
/// source.
bool LoadedExternalKnownNamespaces;

/// Helper for CorrectTypo and CorrectTypoDelayed used to create and
/// populate a new TypoCorrectionConsumer. Returns nullptr if typo correction
/// should be skipped entirely.
std::unique_ptr<TypoCorrectionConsumer>
makeTypoCorrectionConsumer(const DeclarationNameInfo &Typo,
                           Sema::LookupNameKind LookupKind, Scope *S,
                           CXXScopeSpec *SS,
                           CorrectionCandidateCallback &CCC,
                           DeclContext *MemberContext, bool EnteringContext,
                           const ObjCObjectPointerType *OPT,
                           bool ErrorRecovery);

4096public:
const TypoExprState &getTypoExprState(TypoExpr *TE) const;

/// Clears the state of the given TypoExpr.
void clearDelayedTypo(TypoExpr *TE);

/// Look up a name, looking for a single declaration.  Return
/// null if the results were absent, ambiguous, or overloaded.
///
/// It is preferable to use the elaborated form and explicitly handle
/// ambiguity and overloaded.
NamedDecl *LookupSingleName(Scope *S, DeclarationName Name,
                            SourceLocation Loc,
                            LookupNameKind NameKind,
                            RedeclarationKind Redecl
                              = NotForRedeclaration);
bool LookupBuiltin(LookupResult &R);
void LookupNecessaryTypesForBuiltin(Scope *S, unsigned ID);
bool LookupName(LookupResult &R, Scope *S,
                bool AllowBuiltinCreation = false);
bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
                         bool InUnqualifiedLookup = false);
bool LookupQualifiedName(LookupResult &R, DeclContext *LookupCtx,
                         CXXScopeSpec &SS);
bool LookupParsedName(LookupResult &R, Scope *S, CXXScopeSpec *SS,
                      bool AllowBuiltinCreation = false,
                      bool EnteringContext = false);
ObjCProtocolDecl *LookupProtocol(IdentifierInfo *II, SourceLocation IdLoc,
                                 RedeclarationKind Redecl
                                   = NotForRedeclaration);
bool LookupInSuper(LookupResult &R, CXXRecordDecl *Class);

void LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
                                  UnresolvedSetImpl &Functions);

LabelDecl *LookupOrCreateLabel(IdentifierInfo *II, SourceLocation IdentLoc,
                               SourceLocation GnuLabelLoc = SourceLocation());

DeclContextLookupResult LookupConstructors(CXXRecordDecl *Class);
CXXConstructorDecl *LookupDefaultConstructor(CXXRecordDecl *Class);
CXXConstructorDecl *LookupCopyingConstructor(CXXRecordDecl *Class,
                                             unsigned Quals);
CXXMethodDecl *LookupCopyingAssignment(CXXRecordDecl *Class, unsigned Quals,
                                       bool RValueThis, unsigned ThisQuals);
CXXConstructorDecl *LookupMovingConstructor(CXXRecordDecl *Class,
                                            unsigned Quals);
CXXMethodDecl *LookupMovingAssignment(CXXRecordDecl *Class, unsigned Quals,
                                      bool RValueThis, unsigned ThisQuals);
CXXDestructorDecl *LookupDestructor(CXXRecordDecl *Class);

bool checkLiteralOperatorId(const CXXScopeSpec &SS, const UnqualifiedId &Id,
                            bool IsUDSuffix);
LiteralOperatorLookupResult
LookupLiteralOperator(Scope *S, LookupResult &R, ArrayRef<QualType> ArgTys,
                      bool AllowRaw, bool AllowTemplate,
                      bool AllowStringTemplate, bool DiagnoseMissing,
                      StringLiteral *StringLit = nullptr);
bool isKnownName(StringRef name);

/// Status of the function emission on the CUDA/HIP/OpenMP host/device attrs.
enum class FunctionEmissionStatus {
  Emitted,
  CUDADiscarded,     // Discarded due to CUDA/HIP hostness
  OMPDiscarded,      // Discarded due to OpenMP hostness
  TemplateDiscarded, // Discarded due to uninstantiated templates
  Unknown,
};
FunctionEmissionStatus getEmissionStatus(FunctionDecl *Decl,
                                         bool Final = false);

// Whether the callee should be ignored in CUDA/HIP/OpenMP host/device check.
bool shouldIgnoreInHostDeviceCheck(FunctionDecl *Callee);

void ArgumentDependentLookup(DeclarationName Name, SourceLocation Loc,
                             ArrayRef<Expr *> Args, ADLResult &Functions);

void LookupVisibleDecls(Scope *S, LookupNameKind Kind,
                        VisibleDeclConsumer &Consumer,
                        bool IncludeGlobalScope = true,
                        bool LoadExternal = true);
void LookupVisibleDecls(DeclContext *Ctx, LookupNameKind Kind,
                        VisibleDeclConsumer &Consumer,
                        bool IncludeGlobalScope = true,
                        bool IncludeDependentBases = false,
                        bool LoadExternal = true);

enum CorrectTypoKind {
  CTK_NonError,     // CorrectTypo used in a non error recovery situation.
  CTK_ErrorRecovery // CorrectTypo used in normal error recovery.
};

TypoCorrection CorrectTypo(const DeclarationNameInfo &Typo,
                           Sema::LookupNameKind LookupKind,
                           Scope *S, CXXScopeSpec *SS,
                           CorrectionCandidateCallback &CCC,
                           CorrectTypoKind Mode,
                           DeclContext *MemberContext = nullptr,
                           bool EnteringContext = false,
                           const ObjCObjectPointerType *OPT = nullptr,
                           bool RecordFailure = true);

TypoExpr *CorrectTypoDelayed(const DeclarationNameInfo &Typo,
                             Sema::LookupNameKind LookupKind, Scope *S,
                             CXXScopeSpec *SS,
                             CorrectionCandidateCallback &CCC,
                             TypoDiagnosticGenerator TDG,
                             TypoRecoveryCallback TRC, CorrectTypoKind Mode,
                             DeclContext *MemberContext = nullptr,
                             bool EnteringContext = false,
                             const ObjCObjectPointerType *OPT = nullptr);

/// Process any TypoExprs in the given Expr and its children,
/// generating diagnostics as appropriate and returning a new Expr if there
/// were typos that were all successfully corrected and ExprError if one or
/// more typos could not be corrected.
///
/// \param E The Expr to check for TypoExprs.
///
/// \param InitDecl A VarDecl to avoid because the Expr being corrected is its
/// initializer.
///
/// \param RecoverUncorrectedTypos If true, when typo correction fails, it
/// will rebuild the given Expr with all TypoExprs degraded to RecoveryExprs.
///
/// \param Filter A function applied to a newly rebuilt Expr to determine if
/// it is an acceptable/usable result from a single combination of typo
/// corrections. As long as the filter returns ExprError, different
/// combinations of corrections will be tried until all are exhausted.
ExprResult CorrectDelayedTyposInExpr(
    Expr *E, VarDecl *InitDecl = nullptr,
    bool RecoverUncorrectedTypos = false,
    llvm::function_ref<ExprResult(Expr *)> Filter =
        [](Expr *E) -> ExprResult { return E; });

ExprResult CorrectDelayedTyposInExpr(
    ExprResult ER, VarDecl *InitDecl = nullptr,
    bool RecoverUncorrectedTypos = false,
    llvm::function_ref<ExprResult(Expr *)> Filter =
        [](Expr *E) -> ExprResult { return E; }) {
  return ER.isInvalid()
             ? ER
             : CorrectDelayedTyposInExpr(ER.get(), InitDecl,
                                         RecoverUncorrectedTypos, Filter);
}

void diagnoseTypo(const TypoCorrection &Correction,
                  const PartialDiagnostic &TypoDiag,
                  bool ErrorRecovery = true);

void diagnoseTypo(const TypoCorrection &Correction,
                  const PartialDiagnostic &TypoDiag,
                  const PartialDiagnostic &PrevNote,
                  bool ErrorRecovery = true);

void MarkTypoCorrectedFunctionDefinition(const NamedDecl *F);

void FindAssociatedClassesAndNamespaces(SourceLocation InstantiationLoc,
                                        ArrayRef<Expr *> Args,
                                 AssociatedNamespaceSet &AssociatedNamespaces,
                                 AssociatedClassSet &AssociatedClasses);

void FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
                          bool ConsiderLinkage, bool AllowInlineNamespace);

bool CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old);

void DiagnoseAmbiguousLookup(LookupResult &Result);
//@}

/// Attempts to produce a RecoveryExpr after some AST node cannot be created.
ExprResult CreateRecoveryExpr(SourceLocation Begin, SourceLocation End,
                              ArrayRef<Expr *> SubExprs,
                              QualType T = QualType());

ObjCInterfaceDecl *getObjCInterfaceDecl(IdentifierInfo *&Id,
                                        SourceLocation IdLoc,
                                        bool TypoCorrection = false);
FunctionDecl *CreateBuiltin(IdentifierInfo *II, QualType Type, unsigned ID,
                            SourceLocation Loc);
NamedDecl *LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
                               Scope *S, bool ForRedeclaration,
                               SourceLocation Loc);
NamedDecl *ImplicitlyDefineFunction(SourceLocation Loc, IdentifierInfo &II,
                                    Scope *S);
void AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(
    FunctionDecl *FD);
void AddKnownFunctionAttributes(FunctionDecl *FD);

// More parsing and symbol table subroutines.

void ProcessPragmaWeak(Scope *S, Decl *D);
// Decl attributes - this routine is the top level dispatcher.
void ProcessDeclAttributes(Scope *S, Decl *D, const Declarator &PD);
// Helper for delayed processing of attributes.
void ProcessDeclAttributeDelayed(Decl *D,
                                 const ParsedAttributesView &AttrList);
void ProcessDeclAttributeList(Scope *S, Decl *D, const ParsedAttributesView &AL,
                           bool IncludeCXX11Attributes = true);
bool ProcessAccessDeclAttributeList(AccessSpecDecl *ASDecl,
                                 const ParsedAttributesView &AttrList);

void checkUnusedDeclAttributes(Declarator &D);

/// Handles semantic checking for features that are common to all attributes,
/// such as checking whether a parameter was properly specified, or the
/// correct number of arguments were passed, etc. Returns true if the
/// attribute has been diagnosed.
bool checkCommonAttributeFeatures(const Decl *D, const ParsedAttr &A);
bool checkCommonAttributeFeatures(const Stmt *S, const ParsedAttr &A);

/// Determine if type T is a valid subject for a nonnull and similar
/// attributes. By default, we look through references (the behavior used by
/// nonnull), but if the second parameter is true, then we treat a reference
/// type as valid.
bool isValidPointerAttrType(QualType T, bool RefOkay = false);

bool CheckRegparmAttr(const ParsedAttr &attr, unsigned &value);
bool CheckCallingConvAttr(const ParsedAttr &attr, CallingConv &CC,
                          const FunctionDecl *FD = nullptr);
bool CheckAttrTarget(const ParsedAttr &CurrAttr);
bool CheckAttrNoArgs(const ParsedAttr &CurrAttr);
bool checkStringLiteralArgumentAttr(const ParsedAttr &Attr, unsigned ArgNum,
                                    StringRef &Str,
                                    SourceLocation *ArgLocation = nullptr);
llvm::Error isValidSectionSpecifier(StringRef Str);
bool checkSectionName(SourceLocation LiteralLoc, StringRef Str);
bool checkTargetAttr(SourceLocation LiteralLoc, StringRef Str);
bool checkMSInheritanceAttrOnDefinition(
    CXXRecordDecl *RD, SourceRange Range, bool BestCase,
    MSInheritanceModel SemanticSpelling);

void CheckAlignasUnderalignment(Decl *D);

/// Adjust the calling convention of a method to be the ABI default if it
/// wasn't specified explicitly.  This handles method types formed from
/// function type typedefs and typename template arguments.
void adjustMemberFunctionCC(QualType &T, bool IsStatic, bool IsCtorOrDtor,
                            SourceLocation Loc);

// Check if there is an explicit attribute, but only look through parens.
// The intent is to look for an attribute on the current declarator, but not
// one that came from a typedef.
bool hasExplicitCallingConv(QualType T);

/// Get the outermost AttributedType node that sets a calling convention.
/// Valid types should not have multiple attributes with different CCs.
const AttributedType *getCallingConvAttributedType(QualType T) const;

/// Process the attributes before creating an attributed statement. Returns
/// the semantic attributes that have been processed.
void ProcessStmtAttributes(Stmt *Stmt,
                           const ParsedAttributesWithRange &InAttrs,
                           SmallVectorImpl<const Attr *> &OutAttrs);

void WarnConflictingTypedMethods(ObjCMethodDecl *Method,
                                 ObjCMethodDecl *MethodDecl,
                                 bool IsProtocolMethodDecl);

void CheckConflictingOverridingMethod(ObjCMethodDecl *Method,
                                 ObjCMethodDecl *Overridden,
                                 bool IsProtocolMethodDecl);

/// WarnExactTypedMethods - This routine issues a warning if method
/// implementation declaration matches exactly that of its declaration.
void WarnExactTypedMethods(ObjCMethodDecl *Method,
                           ObjCMethodDecl *MethodDecl,
                           bool IsProtocolMethodDecl);

typedef llvm::SmallPtrSet<Selector, 8> SelectorSet;

/// CheckImplementationIvars - This routine checks if the instance variables
/// listed in the implelementation match those listed in the interface.
void CheckImplementationIvars(ObjCImplementationDecl *ImpDecl,
                              ObjCIvarDecl **Fields, unsigned nIvars,
                              SourceLocation Loc);

/// ImplMethodsVsClassMethods - This is main routine to warn if any method
/// remains unimplemented in the class or category \@implementation.
void ImplMethodsVsClassMethods(Scope *S, ObjCImplDecl* IMPDecl,
                               ObjCContainerDecl* IDecl,
                               bool IncompleteImpl = false);

/// DiagnoseUnimplementedProperties - This routine warns on those properties
/// which must be implemented by this implementation.
void DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
                                     ObjCContainerDecl *CDecl,
                                     bool SynthesizeProperties);

/// Diagnose any null-resettable synthesized setters.
void diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl);

/// DefaultSynthesizeProperties - This routine default synthesizes all
/// properties which must be synthesized in the class's \@implementation.
void DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
                                 ObjCInterfaceDecl *IDecl,
                                 SourceLocation AtEnd);
void DefaultSynthesizeProperties(Scope *S, Decl *D, SourceLocation AtEnd);

/// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
/// an ivar synthesized for 'Method' and 'Method' is a property accessor
/// declared in class 'IFace'.
bool IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
                                    ObjCMethodDecl *Method, ObjCIvarDecl *IV);

/// DiagnoseUnusedBackingIvarInAccessor - Issue an 'unused' warning if ivar which
/// backs the property is not used in the property's accessor.
void DiagnoseUnusedBackingIvarInAccessor(Scope *S,
                                         const ObjCImplementationDecl *ImplD);

/// GetIvarBackingPropertyAccessor - If method is a property setter/getter and
/// it property has a backing ivar, returns this ivar; otherwise, returns NULL.
/// It also returns ivar's property on success.
ObjCIvarDecl *GetIvarBackingPropertyAccessor(const ObjCMethodDecl *Method,
                                             const ObjCPropertyDecl *&PDecl) const;

/// Called by ActOnProperty to handle \@property declarations in
/// class extensions.
ObjCPropertyDecl *HandlePropertyInClassExtension(Scope *S,
                    SourceLocation AtLoc,
                    SourceLocation LParenLoc,
                    FieldDeclarator &FD,
                    Selector GetterSel,
                    SourceLocation GetterNameLoc,
                    Selector SetterSel,
                    SourceLocation SetterNameLoc,
                    const bool isReadWrite,
                    unsigned &Attributes,
                    const unsigned AttributesAsWritten,
                    QualType T,
                    TypeSourceInfo *TSI,
                    tok::ObjCKeywordKind MethodImplKind);

/// Called by ActOnProperty and HandlePropertyInClassExtension to
/// handle creating the ObjcPropertyDecl for a category or \@interface.
ObjCPropertyDecl *CreatePropertyDecl(Scope *S,
                                     ObjCContainerDecl *CDecl,
                                     SourceLocation AtLoc,
                                     SourceLocation LParenLoc,
                                     FieldDeclarator &FD,
                                     Selector GetterSel,
                                     SourceLocation GetterNameLoc,
                                     Selector SetterSel,
                                     SourceLocation SetterNameLoc,
                                     const bool isReadWrite,
                                     const unsigned Attributes,
                                     const unsigned AttributesAsWritten,
                                     QualType T,
                                     TypeSourceInfo *TSI,
                                     tok::ObjCKeywordKind MethodImplKind,
                                     DeclContext *lexicalDC = nullptr);

/// AtomicPropertySetterGetterRules - This routine enforces the rule (via
/// warning) when atomic property has one but not the other user-declared
/// setter or getter.
void AtomicPropertySetterGetterRules(ObjCImplDecl* IMPDecl,
                                     ObjCInterfaceDecl* IDecl);

void DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D);

void DiagnoseMissingDesignatedInitOverrides(
                                        const ObjCImplementationDecl *ImplD,
                                        const ObjCInterfaceDecl *IFD);

void DiagnoseDuplicateIvars(ObjCInterfaceDecl *ID, ObjCInterfaceDecl *SID);

enum MethodMatchStrategy {
  MMS_loose,
  MMS_strict
};

/// MatchTwoMethodDeclarations - Checks if two methods' type match and returns
/// true, or false, accordingly.
bool MatchTwoMethodDeclarations(const ObjCMethodDecl *Method,
                                const ObjCMethodDecl *PrevMethod,
                                MethodMatchStrategy strategy = MMS_strict);

/// MatchAllMethodDeclarations - Check methods declaraed in interface or
/// or protocol against those declared in their implementations.
void MatchAllMethodDeclarations(const SelectorSet &InsMap,
                                const SelectorSet &ClsMap,
                                SelectorSet &InsMapSeen,
                                SelectorSet &ClsMapSeen,
                                ObjCImplDecl* IMPDecl,
                                ObjCContainerDecl* IDecl,
                                bool &IncompleteImpl,
                                bool ImmediateClass,
                                bool WarnCategoryMethodImpl=false);

/// CheckCategoryVsClassMethodMatches - Checks that methods implemented in
/// category matches with those implemented in its primary class and
/// warns each time an exact match is found.
void CheckCategoryVsClassMethodMatches(ObjCCategoryImplDecl *CatIMP);

/// Add the given method to the list of globally-known methods.
void addMethodToGlobalList(ObjCMethodList *List, ObjCMethodDecl *Method);

/// Returns default addr space for method qualifiers.
LangAS getDefaultCXXMethodAddrSpace() const;

4495private:
/// AddMethodToGlobalPool - Add an instance or factory method to the global
/// pool. See descriptoin of AddInstanceMethodToGlobalPool.
void AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl, bool instance);

/// LookupMethodInGlobalPool - Returns the instance or factory method and
/// optionally warns if there are multiple signatures.
ObjCMethodDecl *LookupMethodInGlobalPool(Selector Sel, SourceRange R,
                                         bool receiverIdOrClass,
                                         bool instance);

4506public:
/// - Returns instance or factory methods in global method pool for
/// given selector. It checks the desired kind first, if none is found, and
/// parameter checkTheOther is set, it then checks the other kind. If no such
/// method or only one method is found, function returns false; otherwise, it
/// returns true.
bool
CollectMultipleMethodsInGlobalPool(Selector Sel,
                                   SmallVectorImpl<ObjCMethodDecl*>& Methods,
                                   bool InstanceFirst, bool CheckTheOther,
                                   const ObjCObjectType *TypeBound = nullptr);

bool
AreMultipleMethodsInGlobalPool(Selector Sel, ObjCMethodDecl *BestMethod,
                               SourceRange R, bool receiverIdOrClass,
                               SmallVectorImpl<ObjCMethodDecl*>& Methods);

void
DiagnoseMultipleMethodInGlobalPool(SmallVectorImpl<ObjCMethodDecl*> &Methods,
                                   Selector Sel, SourceRange R,
                                   bool receiverIdOrClass);

4528private:
/// - Returns a selector which best matches given argument list or
/// nullptr if none could be found
ObjCMethodDecl *SelectBestMethod(Selector Sel, MultiExprArg Args,
                                 bool IsInstance,
                                 SmallVectorImpl<ObjCMethodDecl*>& Methods);


/// Record the typo correction failure and return an empty correction.
TypoCorrection FailedCorrection(IdentifierInfo *Typo, SourceLocation TypoLoc,
                                bool RecordFailure = true) {
  if (RecordFailure)
    TypoCorrectionFailures[Typo].insert(TypoLoc);
  return TypoCorrection();
}

4544public:
/// AddInstanceMethodToGlobalPool - All instance methods in a translation
/// unit are added to a global pool. This allows us to efficiently associate
/// a selector with a method declaraation for purposes of typechecking
/// messages sent to "id" (where the class of the object is unknown).
void AddInstanceMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
  AddMethodToGlobalPool(Method, impl, /*instance*/true);
}

/// AddFactoryMethodToGlobalPool - Same as above, but for factory methods.
void AddFactoryMethodToGlobalPool(ObjCMethodDecl *Method, bool impl=false) {
  AddMethodToGlobalPool(Method, impl, /*instance*/false);
}

/// AddAnyMethodToGlobalPool - Add any method, instance or factory to global
/// pool.
void AddAnyMethodToGlobalPool(Decl *D);

/// LookupInstanceMethodInGlobalPool - Returns the method and warns if
/// there are multiple signatures.
ObjCMethodDecl *LookupInstanceMethodInGlobalPool(Selector Sel, SourceRange R,
                                                 bool receiverIdOrClass=false) {
  return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
                                  /*instance*/true);
}

/// LookupFactoryMethodInGlobalPool - Returns the method and warns if
/// there are multiple signatures.
ObjCMethodDecl *LookupFactoryMethodInGlobalPool(Selector Sel, SourceRange R,
                                                bool receiverIdOrClass=false) {
  return LookupMethodInGlobalPool(Sel, R, receiverIdOrClass,
                                  /*instance*/false);
}

const ObjCMethodDecl *SelectorsForTypoCorrection(Selector Sel,
                            QualType ObjectType=QualType());
/// LookupImplementedMethodInGlobalPool - Returns the method which has an
/// implementation.
ObjCMethodDecl *LookupImplementedMethodInGlobalPool(Selector Sel);

/// CollectIvarsToConstructOrDestruct - Collect those ivars which require
/// initialization.
void CollectIvarsToConstructOrDestruct(ObjCInterfaceDecl *OI,
                                SmallVectorImpl<ObjCIvarDecl*> &Ivars);

//===--------------------------------------------------------------------===//
// Statement Parsing Callbacks: SemaStmt.cpp.
4591public:
class FullExprArg {
public:
  FullExprArg() : E(nullptr) { }
  FullExprArg(Sema &actions) : E(nullptr) { }

  ExprResult release() {
    return E;
  }

  Expr *get() const { return E; }

  Expr *operator->() {
    return E;
  }

private:
  // FIXME: No need to make the entire Sema class a friend when it's just
  // Sema::MakeFullExpr that needs access to the constructor below.
  friend class Sema;

  explicit FullExprArg(Expr *expr) : E(expr) {}

  Expr *E;
};

FullExprArg MakeFullExpr(Expr *Arg) {
  return MakeFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation());
}
FullExprArg MakeFullExpr(Expr *Arg, SourceLocation CC) {
  return FullExprArg(
      ActOnFinishFullExpr(Arg, CC, /*DiscardedValue*/ false).get());
}
FullExprArg MakeFullDiscardedValueExpr(Expr *Arg) {
  ExprResult FE =
      ActOnFinishFullExpr(Arg, Arg ? Arg->getExprLoc() : SourceLocation(),
                          /*DiscardedValue*/ true);
  return FullExprArg(FE.get());
}

StmtResult ActOnExprStmt(ExprResult Arg, bool DiscardedValue = true);
StmtResult ActOnExprStmtError();

StmtResult ActOnNullStmt(SourceLocation SemiLoc,
                         bool HasLeadingEmptyMacro = false);

void ActOnStartOfCompoundStmt(bool IsStmtExpr);
void ActOnAfterCompoundStatementLeadingPragmas();
void ActOnFinishOfCompoundStmt();
StmtResult ActOnCompoundStmt(SourceLocation L, SourceLocation R,
                             ArrayRef<Stmt *> Elts, bool isStmtExpr);

/// A RAII object to enter scope of a compound statement.
class CompoundScopeRAII {
public:
  CompoundScopeRAII(Sema &S, bool IsStmtExpr = false) : S(S) {
    S.ActOnStartOfCompoundStmt(IsStmtExpr);
  }

  ~CompoundScopeRAII() {
    S.ActOnFinishOfCompoundStmt();
  }

private:
  Sema &S;
};

/// An RAII helper that pops function a function scope on exit.
struct FunctionScopeRAII {
  Sema &S;
  bool Active;
  FunctionScopeRAII(Sema &S) : S(S), Active(true) {}
  ~FunctionScopeRAII() {
    if (Active)
      S.PopFunctionScopeInfo();
  }
  void disable() { Active = false; }
};

StmtResult ActOnDeclStmt(DeclGroupPtrTy Decl,
                                 SourceLocation StartLoc,
                                 SourceLocation EndLoc);
void ActOnForEachDeclStmt(DeclGroupPtrTy Decl);
StmtResult ActOnForEachLValueExpr(Expr *E);
ExprResult ActOnCaseExpr(SourceLocation CaseLoc, ExprResult Val);
StmtResult ActOnCaseStmt(SourceLocation CaseLoc, ExprResult LHS,
                         SourceLocation DotDotDotLoc, ExprResult RHS,
                         SourceLocation ColonLoc);
void ActOnCaseStmtBody(Stmt *CaseStmt, Stmt *SubStmt);

StmtResult ActOnDefaultStmt(SourceLocation DefaultLoc,
                                    SourceLocation ColonLoc,
                                    Stmt *SubStmt, Scope *CurScope);
StmtResult ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl,
                          SourceLocation ColonLoc, Stmt *SubStmt);

StmtResult BuildAttributedStmt(SourceLocation AttrsLoc,
                               ArrayRef<const Attr *> Attrs, Stmt *SubStmt);
StmtResult ActOnAttributedStmt(const ParsedAttributesWithRange &AttrList,
                               Stmt *SubStmt);

class ConditionResult;
StmtResult ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr,
                       SourceLocation LParenLoc, Stmt *InitStmt,
                       ConditionResult Cond, SourceLocation RParenLoc,
                       Stmt *ThenVal, SourceLocation ElseLoc, Stmt *ElseVal);
StmtResult BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
                       SourceLocation LParenLoc, Stmt *InitStmt,
                       ConditionResult Cond, SourceLocation RParenLoc,
                       Stmt *ThenVal, SourceLocation ElseLoc, Stmt *ElseVal);
StmtResult ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
                                  SourceLocation LParenLoc, Stmt *InitStmt,
                                  ConditionResult Cond,
                                  SourceLocation RParenLoc);
StmtResult ActOnFinishSwitchStmt(SourceLocation SwitchLoc,
                                         Stmt *Switch, Stmt *Body);
StmtResult ActOnWhileStmt(SourceLocation WhileLoc, SourceLocation LParenLoc,
                          ConditionResult Cond, SourceLocation RParenLoc,
                          Stmt *Body);
StmtResult ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
                       SourceLocation WhileLoc, SourceLocation CondLParen,
                       Expr *Cond, SourceLocation CondRParen);

StmtResult ActOnForStmt(SourceLocation ForLoc,
                        SourceLocation LParenLoc,
                        Stmt *First,
                        ConditionResult Second,
                        FullExprArg Third,
                        SourceLocation RParenLoc,
                        Stmt *Body);
ExprResult CheckObjCForCollectionOperand(SourceLocation forLoc,
                                         Expr *collection);
StmtResult ActOnObjCForCollectionStmt(SourceLocation ForColLoc,
                                      Stmt *First, Expr *collection,
                                      SourceLocation RParenLoc);
StmtResult FinishObjCForCollectionStmt(Stmt *ForCollection, Stmt *Body);

enum BuildForRangeKind {
  /// Initial building of a for-range statement.
  BFRK_Build,
  /// Instantiation or recovery rebuild of a for-range statement. Don't
  /// attempt any typo-correction.
  BFRK_Rebuild,
  /// Determining whether a for-range statement could be built. Avoid any
  /// unnecessary or irreversible actions.
  BFRK_Check
};

StmtResult ActOnCXXForRangeStmt(Scope *S, SourceLocation ForLoc,
                                SourceLocation CoawaitLoc,
                                Stmt *InitStmt,
                                Stmt *LoopVar,
                                SourceLocation ColonLoc, Expr *Collection,
                                SourceLocation RParenLoc,
                                BuildForRangeKind Kind);
StmtResult BuildCXXForRangeStmt(SourceLocation ForLoc,
                                SourceLocation CoawaitLoc,
                                Stmt *InitStmt,
                                SourceLocation ColonLoc,
                                Stmt *RangeDecl, Stmt *Begin, Stmt *End,
                                Expr *Cond, Expr *Inc,
                                Stmt *LoopVarDecl,
                                SourceLocation RParenLoc,
                                BuildForRangeKind Kind);
StmtResult FinishCXXForRangeStmt(Stmt *ForRange, Stmt *Body);

StmtResult ActOnGotoStmt(SourceLocation GotoLoc,
                         SourceLocation LabelLoc,
                         LabelDecl *TheDecl);
StmtResult ActOnIndirectGotoStmt(SourceLocation GotoLoc,
                                 SourceLocation StarLoc,
                                 Expr *DestExp);
StmtResult ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope);
StmtResult ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope);

void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
                              CapturedRegionKind Kind, unsigned NumParams);
typedef std::pair<StringRef, QualType> CapturedParamNameType;
void ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope,
                              CapturedRegionKind Kind,
                              ArrayRef<CapturedParamNameType> Params,
                              unsigned OpenMPCaptureLevel = 0);
StmtResult ActOnCapturedRegionEnd(Stmt *S);
void ActOnCapturedRegionError();
RecordDecl *CreateCapturedStmtRecordDecl(CapturedDecl *&CD,
                                         SourceLocation Loc,
                                         unsigned NumParams);

struct NamedReturnInfo {
  const VarDecl *Candidate;

  enum Status : uint8_t { None, MoveEligible, MoveEligibleAndCopyElidable };
  Status S;

  bool isMoveEligible() const { return S != None; };
  bool isCopyElidable() const { return S == MoveEligibleAndCopyElidable; }
};
enum class SimplerImplicitMoveMode { ForceOff, Normal, ForceOn };
NamedReturnInfo getNamedReturnInfo(
    Expr *&E, SimplerImplicitMoveMode Mode = SimplerImplicitMoveMode::Normal);
NamedReturnInfo getNamedReturnInfo(const VarDecl *VD);
const VarDecl *getCopyElisionCandidate(NamedReturnInfo &Info,
                                       QualType ReturnType);

ExprResult
PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
                                const NamedReturnInfo &NRInfo, Expr *Value,
                                bool SupressSimplerImplicitMoves = false);

StmtResult ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                           Scope *CurScope);
StmtResult BuildReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp);
StmtResult ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp,
                                   NamedReturnInfo &NRInfo,
                                   bool SupressSimplerImplicitMoves);

StmtResult ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
                           bool IsVolatile, unsigned NumOutputs,
                           unsigned NumInputs, IdentifierInfo **Names,
                           MultiExprArg Constraints, MultiExprArg Exprs,
                           Expr *AsmString, MultiExprArg Clobbers,
                           unsigned NumLabels,
                           SourceLocation RParenLoc);

void FillInlineAsmIdentifierInfo(Expr *Res,
                                 llvm::InlineAsmIdentifierInfo &Info);
ExprResult LookupInlineAsmIdentifier(CXXScopeSpec &SS,
                                     SourceLocation TemplateKWLoc,
                                     UnqualifiedId &Id,
                                     bool IsUnevaluatedContext);
bool LookupInlineAsmField(StringRef Base, StringRef Member,
                          unsigned &Offset, SourceLocation AsmLoc);
ExprResult LookupInlineAsmVarDeclField(Expr *RefExpr, StringRef Member,
                                       SourceLocation AsmLoc);
StmtResult ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
                          ArrayRef<Token> AsmToks,
                          StringRef AsmString,
                          unsigned NumOutputs, unsigned NumInputs,
                          ArrayRef<StringRef> Constraints,
                          ArrayRef<StringRef> Clobbers,
                          ArrayRef<Expr*> Exprs,
                          SourceLocation EndLoc);
LabelDecl *GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
                                 SourceLocation Location,
                                 bool AlwaysCreate);

VarDecl *BuildObjCExceptionDecl(TypeSourceInfo *TInfo, QualType ExceptionType,
                                SourceLocation StartLoc,
                                SourceLocation IdLoc, IdentifierInfo *Id,
                                bool Invalid = false);

Decl *ActOnObjCExceptionDecl(Scope *S, Declarator &D);

StmtResult ActOnObjCAtCatchStmt(SourceLocation AtLoc, SourceLocation RParen,
                                Decl *Parm, Stmt *Body);

StmtResult ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body);

StmtResult ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try,
                              MultiStmtArg Catch, Stmt *Finally);

StmtResult BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw);
StmtResult ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw,
                                Scope *CurScope);
ExprResult ActOnObjCAtSynchronizedOperand(SourceLocation atLoc,
                                          Expr *operand);
StmtResult ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc,
                                       Expr *SynchExpr,
                                       Stmt *SynchBody);

StmtResult ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body);

VarDecl *BuildExceptionDeclaration(Scope *S, TypeSourceInfo *TInfo,
                                   SourceLocation StartLoc,
                                   SourceLocation IdLoc,
                                   IdentifierInfo *Id);

Decl *ActOnExceptionDeclarator(Scope *S, Declarator &D);

StmtResult ActOnCXXCatchBlock(SourceLocation CatchLoc,
                              Decl *ExDecl, Stmt *HandlerBlock);
StmtResult ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock,
                            ArrayRef<Stmt *> Handlers);

StmtResult ActOnSEHTryBlock(bool IsCXXTry, // try (true) or __try (false) ?
                            SourceLocation TryLoc, Stmt *TryBlock,
                            Stmt *Handler);
StmtResult ActOnSEHExceptBlock(SourceLocation Loc,
                               Expr *FilterExpr,
                               Stmt *Block);
void ActOnStartSEHFinallyBlock();
void ActOnAbortSEHFinallyBlock();
StmtResult ActOnFinishSEHFinallyBlock(SourceLocation Loc, Stmt *Block);
StmtResult ActOnSEHLeaveStmt(SourceLocation Loc, Scope *CurScope);

void DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock);

bool ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const;

/// If it's a file scoped decl that must warn if not used, keep track
/// of it.
void MarkUnusedFileScopedDecl(const DeclaratorDecl *D);

/// DiagnoseUnusedExprResult - If the statement passed in is an expression
/// whose result is unused, warn.
void DiagnoseUnusedExprResult(const Stmt *S);
void DiagnoseUnusedNestedTypedefs(const RecordDecl *D);
void DiagnoseUnusedDecl(const NamedDecl *ND);

/// If VD is set but not otherwise used, diagnose, for a parameter or a
/// variable.
void DiagnoseUnusedButSetDecl(const VarDecl *VD);

/// Emit \p DiagID if statement located on \p StmtLoc has a suspicious null
/// statement as a \p Body, and it is located on the same line.
///
/// This helps prevent bugs due to typos, such as:
///     if (condition);
///       do_stuff();
void DiagnoseEmptyStmtBody(SourceLocation StmtLoc,
                           const Stmt *Body,
                           unsigned DiagID);

/// Warn if a for/while loop statement \p S, which is followed by
/// \p PossibleBody, has a suspicious null statement as a body.
void DiagnoseEmptyLoopBody(const Stmt *S,
                           const Stmt *PossibleBody);

/// Warn if a value is moved to itself.
void DiagnoseSelfMove(const Expr *LHSExpr, const Expr *RHSExpr,
                      SourceLocation OpLoc);

/// Warn if we're implicitly casting from a _Nullable pointer type to a
/// _Nonnull one.
void diagnoseNullableToNonnullConversion(QualType DstType, QualType SrcType,
                                         SourceLocation Loc);

/// Warn when implicitly casting 0 to nullptr.
void diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E);

ParsingDeclState PushParsingDeclaration(sema::DelayedDiagnosticPool &pool) {
  return DelayedDiagnostics.push(pool);
}
void PopParsingDeclaration(ParsingDeclState state, Decl *decl);

typedef ProcessingContextState ParsingClassState;
ParsingClassState PushParsingClass() {
  ParsingClassDepth++;
  return DelayedDiagnostics.pushUndelayed();
}
void PopParsingClass(ParsingClassState state) {
  ParsingClassDepth--;
  DelayedDiagnostics.popUndelayed(state);
}

void redelayDiagnostics(sema::DelayedDiagnosticPool &pool);

void DiagnoseAvailabilityOfDecl(NamedDecl *D, ArrayRef<SourceLocation> Locs,
                                const ObjCInterfaceDecl *UnknownObjCClass,
                                bool ObjCPropertyAccess,
                                bool AvoidPartialAvailabilityChecks = false,
                                ObjCInterfaceDecl *ClassReceiver = nullptr);

bool makeUnavailableInSystemHeader(SourceLocation loc,
                                   UnavailableAttr::ImplicitReason reason);

/// Issue any -Wunguarded-availability warnings in \c FD
void DiagnoseUnguardedAvailabilityViolations(Decl *FD);

void handleDelayedAvailabilityCheck(sema::DelayedDiagnostic &DD, Decl *Ctx);

//===--------------------------------------------------------------------===//
// Expression Parsing Callbacks: SemaExpr.cpp.

bool CanUseDecl(NamedDecl *D, bool TreatUnavailableAsInvalid);
bool DiagnoseUseOfDecl(NamedDecl *D, ArrayRef<SourceLocation> Locs,
                       const ObjCInterfaceDecl *UnknownObjCClass = nullptr,
                       bool ObjCPropertyAccess = false,
                       bool AvoidPartialAvailabilityChecks = false,
                       ObjCInterfaceDecl *ClassReciever = nullptr);
void NoteDeletedFunction(FunctionDecl *FD);
void NoteDeletedInheritingConstructor(CXXConstructorDecl *CD);
bool DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *PD,
                                      ObjCMethodDecl *Getter,
                                      SourceLocation Loc);
void DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc,
                           ArrayRef<Expr *> Args);

void PushExpressionEvaluationContext(
    ExpressionEvaluationContext NewContext, Decl *LambdaContextDecl = nullptr,
    ExpressionEvaluationContextRecord::ExpressionKind Type =
        ExpressionEvaluationContextRecord::EK_Other);
enum ReuseLambdaContextDecl_t { ReuseLambdaContextDecl };
void PushExpressionEvaluationContext(
    ExpressionEvaluationContext NewContext, ReuseLambdaContextDecl_t,
    ExpressionEvaluationContextRecord::ExpressionKind Type =
        ExpressionEvaluationContextRecord::EK_Other);
void PopExpressionEvaluationContext();

void DiscardCleanupsInEvaluationContext();

ExprResult TransformToPotentiallyEvaluated(Expr *E);
ExprResult HandleExprEvaluationContextForTypeof(Expr *E);

ExprResult CheckUnevaluatedOperand(Expr *E);
void CheckUnusedVolatileAssignment(Expr *E);

ExprResult ActOnConstantExpression(ExprResult Res);

// Functions for marking a declaration referenced.  These functions also
// contain the relevant logic for marking if a reference to a function or
// variable is an odr-use (in the C++11 sense).  There are separate variants
// for expressions referring to a decl; these exist because odr-use marking
// needs to be delayed for some constant variables when we build one of the
// named expressions.
//
// MightBeOdrUse indicates whether the use could possibly be an odr-use, and
// should usually be true. This only needs to be set to false if the lack of
// odr-use cannot be determined from the current context (for instance,
// because the name denotes a virtual function and was written without an
// explicit nested-name-specifier).
void MarkAnyDeclReferenced(SourceLocation Loc, Decl *D, bool MightBeOdrUse);
void MarkFunctionReferenced(SourceLocation Loc, FunctionDecl *Func,
                            bool MightBeOdrUse = true);
void MarkVariableReferenced(SourceLocation Loc, VarDecl *Var);
void MarkDeclRefReferenced(DeclRefExpr *E, const Expr *Base = nullptr);
void MarkMemberReferenced(MemberExpr *E);
void MarkFunctionParmPackReferenced(FunctionParmPackExpr *E);
void MarkCaptureUsedInEnclosingContext(VarDecl *Capture, SourceLocation Loc,
                                       unsigned CapturingScopeIndex);

ExprResult CheckLValueToRValueConversionOperand(Expr *E);
void CleanupVarDeclMarking();

enum TryCaptureKind {
  TryCapture_Implicit, TryCapture_ExplicitByVal, TryCapture_ExplicitByRef
};

/// Try to capture the given variable.
///
/// \param Var The variable to capture.
///
/// \param Loc The location at which the capture occurs.
///
/// \param Kind The kind of capture, which may be implicit (for either a
/// block or a lambda), or explicit by-value or by-reference (for a lambda).
///
/// \param EllipsisLoc The location of the ellipsis, if one is provided in
/// an explicit lambda capture.
///
/// \param BuildAndDiagnose Whether we are actually supposed to add the
/// captures or diagnose errors. If false, this routine merely check whether
/// the capture can occur without performing the capture itself or complaining
/// if the variable cannot be captured.
///
/// \param CaptureType Will be set to the type of the field used to capture
/// this variable in the innermost block or lambda. Only valid when the
/// variable can be captured.
///
/// \param DeclRefType Will be set to the type of a reference to the capture
/// from within the current scope. Only valid when the variable can be
/// captured.
///
/// \param FunctionScopeIndexToStopAt If non-null, it points to the index
/// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
/// This is useful when enclosing lambdas must speculatively capture
/// variables that may or may not be used in certain specializations of
/// a nested generic lambda.
///
/// \returns true if an error occurred (i.e., the variable cannot be
/// captured) and false if the capture succeeded.
bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc, TryCaptureKind Kind,
                        SourceLocation EllipsisLoc, bool BuildAndDiagnose,
                        QualType &CaptureType,
                        QualType &DeclRefType,
                        const unsigned *const FunctionScopeIndexToStopAt);

/// Try to capture the given variable.
bool tryCaptureVariable(VarDecl *Var, SourceLocation Loc,
                        TryCaptureKind Kind = TryCapture_Implicit,
                        SourceLocation EllipsisLoc = SourceLocation());

/// Checks if the variable must be captured.
bool NeedToCaptureVariable(VarDecl *Var, SourceLocation Loc);

/// Given a variable, determine the type that a reference to that
/// variable will have in the given scope.
QualType getCapturedDeclRefType(VarDecl *Var, SourceLocation Loc);

/// Mark all of the declarations referenced within a particular AST node as
/// referenced. Used when template instantiation instantiates a non-dependent
/// type -- entities referenced by the type are now referenced.
void MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T);
void MarkDeclarationsReferencedInExpr(Expr *E,
                                      bool SkipLocalVariables = false);

/// Try to recover by turning the given expression into a
/// call.  Returns true if recovery was attempted or an error was
/// emitted; this may also leave the ExprResult invalid.
bool tryToRecoverWithCall(ExprResult &E, const PartialDiagnostic &PD,
                          bool ForceComplain = false,
                          bool (*IsPlausibleResult)(QualType) = nullptr);

/// Figure out if an expression could be turned into a call.
bool tryExprAsCall(Expr &E, QualType &ZeroArgCallReturnTy,
                   UnresolvedSetImpl &NonTemplateOverloads);

/// Try to convert an expression \p E to type \p Ty. Returns the result of the
/// conversion.
ExprResult tryConvertExprToType(Expr *E, QualType Ty);

/// Conditionally issue a diagnostic based on the current
/// evaluation context.
///
/// \param Statement If Statement is non-null, delay reporting the
/// diagnostic until the function body is parsed, and then do a basic
/// reachability analysis to determine if the statement is reachable.
/// If it is unreachable, the diagnostic will not be emitted.
bool DiagRuntimeBehavior(SourceLocation Loc, const Stmt *Statement,
                         const PartialDiagnostic &PD);
/// Similar, but diagnostic is only produced if all the specified statements
/// are reachable.
bool DiagRuntimeBehavior(SourceLocation Loc, ArrayRef<const Stmt*> Stmts,
                         const PartialDiagnostic &PD);

// Primary Expressions.
SourceRange getExprRange(Expr *E) const;

ExprResult ActOnIdExpression(
    Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    UnqualifiedId &Id, bool HasTrailingLParen, bool IsAddressOfOperand,
    CorrectionCandidateCallback *CCC = nullptr,
    bool IsInlineAsmIdentifier = false, Token *KeywordReplacement = nullptr);

void DecomposeUnqualifiedId(const UnqualifiedId &Id,
                            TemplateArgumentListInfo &Buffer,
                            DeclarationNameInfo &NameInfo,
                            const TemplateArgumentListInfo *&TemplateArgs);

bool DiagnoseDependentMemberLookup(LookupResult &R);

bool
DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R,
                    CorrectionCandidateCallback &CCC,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr,
                    ArrayRef<Expr *> Args = None, TypoExpr **Out = nullptr);

DeclResult LookupIvarInObjCMethod(LookupResult &Lookup, Scope *S,
                                  IdentifierInfo *II);
ExprResult BuildIvarRefExpr(Scope *S, SourceLocation Loc, ObjCIvarDecl *IV);

ExprResult LookupInObjCMethod(LookupResult &LookUp, Scope *S,
                              IdentifierInfo *II,
                              bool AllowBuiltinCreation=false);

ExprResult ActOnDependentIdExpression(const CXXScopeSpec &SS,
                                      SourceLocation TemplateKWLoc,
                                      const DeclarationNameInfo &NameInfo,
                                      bool isAddressOfOperand,
                              const TemplateArgumentListInfo *TemplateArgs);

/// If \p D cannot be odr-used in the current expression evaluation context,
/// return a reason explaining why. Otherwise, return NOUR_None.
NonOdrUseReason getNonOdrUseReasonInCurrentContext(ValueDecl *D);

DeclRefExpr *BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                              SourceLocation Loc,
                              const CXXScopeSpec *SS = nullptr);
DeclRefExpr *
BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                 const DeclarationNameInfo &NameInfo,
                 const CXXScopeSpec *SS = nullptr,
                 NamedDecl *FoundD = nullptr,
                 SourceLocation TemplateKWLoc = SourceLocation(),
                 const TemplateArgumentListInfo *TemplateArgs = nullptr);
DeclRefExpr *
BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK,
                 const DeclarationNameInfo &NameInfo,
                 NestedNameSpecifierLoc NNS,
                 NamedDecl *FoundD = nullptr,
                 SourceLocation TemplateKWLoc = SourceLocation(),
                 const TemplateArgumentListInfo *TemplateArgs = nullptr);

ExprResult
BuildAnonymousStructUnionMemberReference(
    const CXXScopeSpec &SS,
    SourceLocation nameLoc,
    IndirectFieldDecl *indirectField,
    DeclAccessPair FoundDecl = DeclAccessPair::make(nullptr, AS_none),
    Expr *baseObjectExpr = nullptr,
    SourceLocation opLoc = SourceLocation());

ExprResult BuildPossibleImplicitMemberExpr(
    const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R,
    const TemplateArgumentListInfo *TemplateArgs, const Scope *S,
    UnresolvedLookupExpr *AsULE = nullptr);
ExprResult BuildImplicitMemberExpr(const CXXScopeSpec &SS,
                                   SourceLocation TemplateKWLoc,
                                   LookupResult &R,
                              const TemplateArgumentListInfo *TemplateArgs,
                                   bool IsDefiniteInstance,
                                   const Scope *S);
bool UseArgumentDependentLookup(const CXXScopeSpec &SS,
                                const LookupResult &R,
                                bool HasTrailingLParen);

ExprResult
BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS,
                                  const DeclarationNameInfo &NameInfo,
                                  bool IsAddressOfOperand, const Scope *S,
                                  TypeSourceInfo **RecoveryTSI = nullptr);

ExprResult BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
                                     SourceLocation TemplateKWLoc,
                              const DeclarationNameInfo &NameInfo,
                              const TemplateArgumentListInfo *TemplateArgs);

ExprResult BuildDeclarationNameExpr(const CXXScopeSpec &SS,
                                    LookupResult &R,
                                    bool NeedsADL,
                                    bool AcceptInvalidDecl = false);
ExprResult BuildDeclarationNameExpr(
    const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, NamedDecl *D,
    NamedDecl *FoundD = nullptr,
    const TemplateArgumentListInfo *TemplateArgs = nullptr,
    bool AcceptInvalidDecl = false);

ExprResult BuildLiteralOperatorCall(LookupResult &R,
                    DeclarationNameInfo &SuffixInfo,
                    ArrayRef<Expr *> Args,
                    SourceLocation LitEndLoc,
                    TemplateArgumentListInfo *ExplicitTemplateArgs = nullptr);

ExprResult BuildPredefinedExpr(SourceLocation Loc,
                               PredefinedExpr::IdentKind IK);
ExprResult ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind);
ExprResult ActOnIntegerConstant(SourceLocation Loc, uint64_t Val);

ExprResult BuildSYCLUniqueStableNameExpr(SourceLocation OpLoc,
                                         SourceLocation LParen,
                                         SourceLocation RParen,
                                         TypeSourceInfo *TSI);
ExprResult ActOnSYCLUniqueStableNameExpr(SourceLocation OpLoc,
                                         SourceLocation LParen,
                                         SourceLocation RParen,
                                         ParsedType ParsedTy);

bool CheckLoopHintExpr(Expr *E, SourceLocation Loc);

ExprResult ActOnNumericConstant(const Token &Tok, Scope *UDLScope = nullptr);
ExprResult ActOnCharacterConstant(const Token &Tok,
                                  Scope *UDLScope = nullptr);
ExprResult ActOnParenExpr(SourceLocation L, SourceLocation R, Expr *E);
ExprResult ActOnParenListExpr(SourceLocation L,
                              SourceLocation R,
                              MultiExprArg Val);

/// ActOnStringLiteral - The specified tokens were lexed as pasted string
/// fragments (e.g. "foo" "bar" L"baz").
ExprResult ActOnStringLiteral(ArrayRef<Token> StringToks,
                              Scope *UDLScope = nullptr);

ExprResult ActOnGenericSelectionExpr(SourceLocation KeyLoc,
                                     SourceLocation DefaultLoc,
                                     SourceLocation RParenLoc,
                                     Expr *ControllingExpr,
                                     ArrayRef<ParsedType> ArgTypes,
                                     ArrayRef<Expr *> ArgExprs);
ExprResult CreateGenericSelectionExpr(SourceLocation KeyLoc,
                                      SourceLocation DefaultLoc,
                                      SourceLocation RParenLoc,
                                      Expr *ControllingExpr,
                                      ArrayRef<TypeSourceInfo *> Types,
                                      ArrayRef<Expr *> Exprs);

// Binary/Unary Operators.  'Tok' is the token for the operator.
ExprResult CreateBuiltinUnaryOp(SourceLocation OpLoc, UnaryOperatorKind Opc,
                                Expr *InputExpr);
ExprResult BuildUnaryOp(Scope *S, SourceLocation OpLoc,
                        UnaryOperatorKind Opc, Expr *Input);
ExprResult ActOnUnaryOp(Scope *S, SourceLocation OpLoc,
                        tok::TokenKind Op, Expr *Input);

bool isQualifiedMemberAccess(Expr *E);
QualType CheckAddressOfOperand(ExprResult &Operand, SourceLocation OpLoc);

ExprResult CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo,
                                          SourceLocation OpLoc,
                                          UnaryExprOrTypeTrait ExprKind,
                                          SourceRange R);
ExprResult CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc,
                                          UnaryExprOrTypeTrait ExprKind);
ExprResult
  ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc,
                                UnaryExprOrTypeTrait ExprKind,
                                bool IsType, void *TyOrEx,
                                SourceRange ArgRange);

ExprResult CheckPlaceholderExpr(Expr *E);
bool CheckVecStepExpr(Expr *E);

bool CheckUnaryExprOrTypeTraitOperand(Expr *E, UnaryExprOrTypeTrait ExprKind);
bool CheckUnaryExprOrTypeTraitOperand(QualType ExprType, SourceLocation OpLoc,
                                      SourceRange ExprRange,
                                      UnaryExprOrTypeTrait ExprKind);
ExprResult ActOnSizeofParameterPackExpr(Scope *S,
                                        SourceLocation OpLoc,
                                        IdentifierInfo &Name,
                                        SourceLocation NameLoc,
                                        SourceLocation RParenLoc);
ExprResult ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc,
                               tok::TokenKind Kind, Expr *Input);

ExprResult ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc,
                                   Expr *Idx, SourceLocation RLoc);
ExprResult CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc,
                                           Expr *Idx, SourceLocation RLoc);

ExprResult CreateBuiltinMatrixSubscriptExpr(Expr *Base, Expr *RowIdx,
                                            Expr *ColumnIdx,
                                            SourceLocation RBLoc);

ExprResult ActOnOMPArraySectionExpr(Expr *Base, SourceLocation LBLoc,
                                    Expr *LowerBound,
                                    SourceLocation ColonLocFirst,
                                    SourceLocation ColonLocSecond,
                                    Expr *Length, Expr *Stride,
                                    SourceLocation RBLoc);
ExprResult ActOnOMPArrayShapingExpr(Expr *Base, SourceLocation LParenLoc,
                                    SourceLocation RParenLoc,
                                    ArrayRef<Expr *> Dims,
                                    ArrayRef<SourceRange> Brackets);

/// Data structure for iterator expression.
struct OMPIteratorData {
  IdentifierInfo *DeclIdent = nullptr;
  SourceLocation DeclIdentLoc;
  ParsedType Type;
  OMPIteratorExpr::IteratorRange Range;
  SourceLocation AssignLoc;
  SourceLocation ColonLoc;
  SourceLocation SecColonLoc;
};

ExprResult ActOnOMPIteratorExpr(Scope *S, SourceLocation IteratorKwLoc,
                                SourceLocation LLoc, SourceLocation RLoc,
                                ArrayRef<OMPIteratorData> Data);

// This struct is for use by ActOnMemberAccess to allow
// BuildMemberReferenceExpr to be able to reinvoke ActOnMemberAccess after
// changing the access operator from a '.' to a '->' (to see if that is the
// change needed to fix an error about an unknown member, e.g. when the class
// defines a custom operator->).
struct ActOnMemberAccessExtraArgs {
  Scope *S;
  UnqualifiedId &Id;
  Decl *ObjCImpDecl;
};

ExprResult BuildMemberReferenceExpr(
    Expr *Base, QualType BaseType, SourceLocation OpLoc, bool IsArrow,
    CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    NamedDecl *FirstQualifierInScope, const DeclarationNameInfo &NameInfo,
    const TemplateArgumentListInfo *TemplateArgs,
    const Scope *S,
    ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);

ExprResult
BuildMemberReferenceExpr(Expr *Base, QualType BaseType, SourceLocation OpLoc,
                         bool IsArrow, const CXXScopeSpec &SS,
                         SourceLocation TemplateKWLoc,
                         NamedDecl *FirstQualifierInScope, LookupResult &R,
                         const TemplateArgumentListInfo *TemplateArgs,
                         const Scope *S,
                         bool SuppressQualifierCheck = false,
                         ActOnMemberAccessExtraArgs *ExtraArgs = nullptr);

ExprResult BuildFieldReferenceExpr(Expr *BaseExpr, bool IsArrow,
                                   SourceLocation OpLoc,
                                   const CXXScopeSpec &SS, FieldDecl *Field,
                                   DeclAccessPair FoundDecl,
                                   const DeclarationNameInfo &MemberNameInfo);

ExprResult PerformMemberExprBaseConversion(Expr *Base, bool IsArrow);

bool CheckQualifiedMemberReference(Expr *BaseExpr, QualType BaseType,
                                   const CXXScopeSpec &SS,
                                   const LookupResult &R);

ExprResult ActOnDependentMemberExpr(Expr *Base, QualType BaseType,
                                    bool IsArrow, SourceLocation OpLoc,
                                    const CXXScopeSpec &SS,
                                    SourceLocation TemplateKWLoc,
                                    NamedDecl *FirstQualifierInScope,
                             const DeclarationNameInfo &NameInfo,
                             const TemplateArgumentListInfo *TemplateArgs);

ExprResult ActOnMemberAccessExpr(Scope *S, Expr *Base,
                                 SourceLocation OpLoc,
                                 tok::TokenKind OpKind,
                                 CXXScopeSpec &SS,
                                 SourceLocation TemplateKWLoc,
                                 UnqualifiedId &Member,
                                 Decl *ObjCImpDecl);

MemberExpr *
BuildMemberExpr(Expr *Base, bool IsArrow, SourceLocation OpLoc,
                const CXXScopeSpec *SS, SourceLocation TemplateKWLoc,
                ValueDecl *Member, DeclAccessPair FoundDecl,
                bool HadMultipleCandidates,
                const DeclarationNameInfo &MemberNameInfo, QualType Ty,
                ExprValueKind VK, ExprObjectKind OK,
                const TemplateArgumentListInfo *TemplateArgs = nullptr);
MemberExpr *
BuildMemberExpr(Expr *Base, bool IsArrow, SourceLocation OpLoc,
                NestedNameSpecifierLoc NNS, SourceLocation TemplateKWLoc,
                ValueDecl *Member, DeclAccessPair FoundDecl,
                bool HadMultipleCandidates,
                const DeclarationNameInfo &MemberNameInfo, QualType Ty,
                ExprValueKind VK, ExprObjectKind OK,
                const TemplateArgumentListInfo *TemplateArgs = nullptr);

void ActOnDefaultCtorInitializers(Decl *CDtorDecl);
bool ConvertArgumentsForCall(CallExpr *Call, Expr *Fn,
                             FunctionDecl *FDecl,
                             const FunctionProtoType *Proto,
                             ArrayRef<Expr *> Args,
                             SourceLocation RParenLoc,
                             bool ExecConfig = false);
void CheckStaticArrayArgument(SourceLocation CallLoc,
                              ParmVarDecl *Param,
                              const Expr *ArgExpr);

/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments.
/// This provides the location of the left/right parens and a list of comma
/// locations.
ExprResult ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
                         MultiExprArg ArgExprs, SourceLocation RParenLoc,
                         Expr *ExecConfig = nullptr);
ExprResult BuildCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc,
                         MultiExprArg ArgExprs, SourceLocation RParenLoc,
                         Expr *ExecConfig = nullptr,
                         bool IsExecConfig = false,
                         bool AllowRecovery = false);
Expr *BuildBuiltinCallExpr(SourceLocation Loc, Builtin::ID Id,
                           MultiExprArg CallArgs);
enum class AtomicArgumentOrder { API, AST };
ExprResult
BuildAtomicExpr(SourceRange CallRange, SourceRange ExprRange,
                SourceLocation RParenLoc, MultiExprArg Args,
                AtomicExpr::AtomicOp Op,
                AtomicArgumentOrder ArgOrder = AtomicArgumentOrder::API);
ExprResult
BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, SourceLocation LParenLoc,
                      ArrayRef<Expr *> Arg, SourceLocation RParenLoc,
                      Expr *Config = nullptr, bool IsExecConfig = false,
                      ADLCallKind UsesADL = ADLCallKind::NotADL);

ExprResult ActOnCUDAExecConfigExpr(Scope *S, SourceLocation LLLLoc,
                                   MultiExprArg ExecConfig,
                                   SourceLocation GGGLoc);

ExprResult ActOnCastExpr(Scope *S, SourceLocation LParenLoc,
                         Declarator &D, ParsedType &Ty,
                         SourceLocation RParenLoc, Expr *CastExpr);
ExprResult BuildCStyleCastExpr(SourceLocation LParenLoc,
                               TypeSourceInfo *Ty,
                               SourceLocation RParenLoc,
                               Expr *Op);
CastKind PrepareScalarCast(ExprResult &src, QualType destType);

/// Build an altivec or OpenCL literal.
ExprResult BuildVectorLiteral(SourceLocation LParenLoc,
                              SourceLocation RParenLoc, Expr *E,
                              TypeSourceInfo *TInfo);

ExprResult MaybeConvertParenListExprToParenExpr(Scope *S, Expr *ME);

ExprResult ActOnCompoundLiteral(SourceLocation LParenLoc,
                                ParsedType Ty,
                                SourceLocation RParenLoc,
                                Expr *InitExpr);

ExprResult BuildCompoundLiteralExpr(SourceLocation LParenLoc,
                                    TypeSourceInfo *TInfo,
                                    SourceLocation RParenLoc,
                                    Expr *LiteralExpr);

ExprResult ActOnInitList(SourceLocation LBraceLoc,
                         MultiExprArg InitArgList,
                         SourceLocation RBraceLoc);

ExprResult BuildInitList(SourceLocation LBraceLoc,
                         MultiExprArg InitArgList,
                         SourceLocation RBraceLoc);

ExprResult ActOnDesignatedInitializer(Designation &Desig,
                                      SourceLocation EqualOrColonLoc,
                                      bool GNUSyntax,
                                      ExprResult Init);

5492private:
static BinaryOperatorKind ConvertTokenKindToBinaryOpcode(tok::TokenKind Kind);

5495public:
ExprResult ActOnBinOp(Scope *S, SourceLocation TokLoc,
                      tok::TokenKind Kind, Expr *LHSExpr, Expr *RHSExpr);
ExprResult BuildBinOp(Scope *S, SourceLocation OpLoc,
                      BinaryOperatorKind Opc, Expr *LHSExpr, Expr *RHSExpr);
ExprResult CreateBuiltinBinOp(SourceLocation OpLoc, BinaryOperatorKind Opc,
                              Expr *LHSExpr, Expr *RHSExpr);
void LookupBinOp(Scope *S, SourceLocation OpLoc, BinaryOperatorKind Opc,
                 UnresolvedSetImpl &Functions);

void DiagnoseCommaOperator(const Expr *LHS, SourceLocation Loc);

/// ActOnConditionalOp - Parse a ?: operation.  Note that 'LHS' may be null
/// in the case of a the GNU conditional expr extension.
ExprResult ActOnConditionalOp(SourceLocation QuestionLoc,
                              SourceLocation ColonLoc,
                              Expr *CondExpr, Expr *LHSExpr, Expr *RHSExpr);

/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo".
ExprResult ActOnAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc,
                          LabelDecl *TheDecl);

void ActOnStartStmtExpr();
ExprResult ActOnStmtExpr(Scope *S, SourceLocation LPLoc, Stmt *SubStmt,
                         SourceLocation RPLoc);
ExprResult BuildStmtExpr(SourceLocation LPLoc, Stmt *SubStmt,
                         SourceLocation RPLoc, unsigned TemplateDepth);
// Handle the final expression in a statement expression.
ExprResult ActOnStmtExprResult(ExprResult E);
void ActOnStmtExprError();

// __builtin_offsetof(type, identifier(.identifier|[expr])*)
struct OffsetOfComponent {
  SourceLocation LocStart, LocEnd;
  bool isBrackets;  // true if [expr], false if .ident
  union {
    IdentifierInfo *IdentInfo;
    Expr *E;
  } U;
};

/// __builtin_offsetof(type, a.b[123][456].c)
ExprResult BuildBuiltinOffsetOf(SourceLocation BuiltinLoc,
                                TypeSourceInfo *TInfo,
                                ArrayRef<OffsetOfComponent> Components,
                                SourceLocation RParenLoc);
ExprResult ActOnBuiltinOffsetOf(Scope *S,
                                SourceLocation BuiltinLoc,
                                SourceLocation TypeLoc,
                                ParsedType ParsedArgTy,
                                ArrayRef<OffsetOfComponent> Components,
                                SourceLocation RParenLoc);

// __builtin_choose_expr(constExpr, expr1, expr2)
ExprResult ActOnChooseExpr(SourceLocation BuiltinLoc,
                           Expr *CondExpr, Expr *LHSExpr,
                           Expr *RHSExpr, SourceLocation RPLoc);

// __builtin_va_arg(expr, type)
ExprResult ActOnVAArg(SourceLocation BuiltinLoc, Expr *E, ParsedType Ty,
                      SourceLocation RPLoc);
ExprResult BuildVAArgExpr(SourceLocation BuiltinLoc, Expr *E,
                          TypeSourceInfo *TInfo, SourceLocation RPLoc);

// __builtin_LINE(), __builtin_FUNCTION(), __builtin_FILE(),
// __builtin_COLUMN()
ExprResult ActOnSourceLocExpr(SourceLocExpr::IdentKind Kind,
                              SourceLocation BuiltinLoc,
                              SourceLocation RPLoc);

// Build a potentially resolved SourceLocExpr.
ExprResult BuildSourceLocExpr(SourceLocExpr::IdentKind Kind,
                              SourceLocation BuiltinLoc, SourceLocation RPLoc,
                              DeclContext *ParentContext);

// __null
ExprResult ActOnGNUNullExpr(SourceLocation TokenLoc);

bool CheckCaseExpression(Expr *E);

/// Describes the result of an "if-exists" condition check.
enum IfExistsResult {
  /// The symbol exists.
  IER_Exists,

  /// The symbol does not exist.
  IER_DoesNotExist,

  /// The name is a dependent name, so the results will differ
  /// from one instantiation to the next.
  IER_Dependent,

  /// An error occurred.
  IER_Error
};

IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope *S, CXXScopeSpec &SS,
                             const DeclarationNameInfo &TargetNameInfo);

IfExistsResult
CheckMicrosoftIfExistsSymbol(Scope *S, SourceLocation KeywordLoc,
                             bool IsIfExists, CXXScopeSpec &SS,
                             UnqualifiedId &Name);

StmtResult BuildMSDependentExistsStmt(SourceLocation KeywordLoc,
                                      bool IsIfExists,
                                      NestedNameSpecifierLoc QualifierLoc,
                                      DeclarationNameInfo NameInfo,
                                      Stmt *Nested);
StmtResult ActOnMSDependentExistsStmt(SourceLocation KeywordLoc,
                                      bool IsIfExists,
                                      CXXScopeSpec &SS, UnqualifiedId &Name,
                                      Stmt *Nested);

//===------------------------- "Block" Extension ------------------------===//

/// ActOnBlockStart - This callback is invoked when a block literal is
/// started.
void ActOnBlockStart(SourceLocation CaretLoc, Scope *CurScope);

/// ActOnBlockArguments - This callback allows processing of block arguments.
/// If there are no arguments, this is still invoked.
void ActOnBlockArguments(SourceLocation CaretLoc, Declarator &ParamInfo,
                         Scope *CurScope);

/// ActOnBlockError - If there is an error parsing a block, this callback
/// is invoked to pop the information about the block from the action impl.
void ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope);

/// ActOnBlockStmtExpr - This is called when the body of a block statement
/// literal was successfully completed.  ^(int x){...}
ExprResult ActOnBlockStmtExpr(SourceLocation CaretLoc, Stmt *Body,
                              Scope *CurScope);

//===---------------------------- Clang Extensions ----------------------===//

/// __builtin_convertvector(...)
ExprResult ActOnConvertVectorExpr(Expr *E, ParsedType ParsedDestTy,
                                  SourceLocation BuiltinLoc,
                                  SourceLocation RParenLoc);

//===---------------------------- OpenCL Features -----------------------===//

/// __builtin_astype(...)
ExprResult ActOnAsTypeExpr(Expr *E, ParsedType ParsedDestTy,
                           SourceLocation BuiltinLoc,
                           SourceLocation RParenLoc);
ExprResult BuildAsTypeExpr(Expr *E, QualType DestTy,
                           SourceLocation BuiltinLoc,
                           SourceLocation RParenLoc);

//===---------------------------- C++ Features --------------------------===//

// Act on C++ namespaces
Decl *ActOnStartNamespaceDef(Scope *S, SourceLocation InlineLoc,
                             SourceLocation NamespaceLoc,
                             SourceLocation IdentLoc, IdentifierInfo *Ident,
                             SourceLocation LBrace,
                             const ParsedAttributesView &AttrList,
                             UsingDirectiveDecl *&UsingDecl);
void ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace);

NamespaceDecl *getStdNamespace() const;
NamespaceDecl *getOrCreateStdNamespace();

NamespaceDecl *lookupStdExperimentalNamespace();

CXXRecordDecl *getStdBadAlloc() const;
EnumDecl *getStdAlignValT() const;

5666private:
// A cache representing if we've fully checked the various comparison category
// types stored in ASTContext. The bit-index corresponds to the integer value
// of a ComparisonCategoryType enumerator.
llvm::SmallBitVector FullyCheckedComparisonCategories;

ValueDecl *tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
                                       CXXScopeSpec &SS,
                                       ParsedType TemplateTypeTy,
                                       IdentifierInfo *MemberOrBase);

5677public:
enum class ComparisonCategoryUsage {
  /// The '<=>' operator was used in an expression and a builtin operator
  /// was selected.
  OperatorInExpression,
  /// A defaulted 'operator<=>' needed the comparison category. This
  /// typically only applies to 'std::strong_ordering', due to the implicit
  /// fallback return value.
  DefaultedOperator,
};

/// Lookup the specified comparison category types in the standard
///   library, an check the VarDecls possibly returned by the operator<=>
///   builtins for that type.
///
/// \return The type of the comparison category type corresponding to the
///   specified Kind, or a null type if an error occurs
QualType CheckComparisonCategoryType(ComparisonCategoryType Kind,
                                     SourceLocation Loc,
                                     ComparisonCategoryUsage Usage);

/// Tests whether Ty is an instance of std::initializer_list and, if
/// it is and Element is not NULL, assigns the element type to Element.
bool isStdInitializerList(QualType Ty, QualType *Element);

/// Looks for the std::initializer_list template and instantiates it
/// with Element, or emits an error if it's not found.
///
/// \returns The instantiated template, or null on error.
QualType BuildStdInitializerList(QualType Element, SourceLocation Loc);

/// Determine whether Ctor is an initializer-list constructor, as
/// defined in [dcl.init.list]p2.
bool isInitListConstructor(const FunctionDecl *Ctor);

Decl *ActOnUsingDirective(Scope *CurScope, SourceLocation UsingLoc,
                          SourceLocation NamespcLoc, CXXScopeSpec &SS,
                          SourceLocation IdentLoc,
                          IdentifierInfo *NamespcName,
                          const ParsedAttributesView &AttrList);

void PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir);

Decl *ActOnNamespaceAliasDef(Scope *CurScope,
                             SourceLocation NamespaceLoc,
                             SourceLocation AliasLoc,
                             IdentifierInfo *Alias,
                             CXXScopeSpec &SS,
                             SourceLocation IdentLoc,
                             IdentifierInfo *Ident);

void FilterUsingLookup(Scope *S, LookupResult &lookup);
void HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow);
bool CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Target,
                          const LookupResult &PreviousDecls,
                          UsingShadowDecl *&PrevShadow);
UsingShadowDecl *BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD,
                                      NamedDecl *Target,
                                      UsingShadowDecl *PrevDecl);

bool CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
                                 bool HasTypenameKeyword,
                                 const CXXScopeSpec &SS,
                                 SourceLocation NameLoc,
                                 const LookupResult &Previous);
bool CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename,
                             const CXXScopeSpec &SS,
                             const DeclarationNameInfo &NameInfo,
                             SourceLocation NameLoc,
                             const LookupResult *R = nullptr,
                             const UsingDecl *UD = nullptr);

NamedDecl *BuildUsingDeclaration(
    Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
    bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
    DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
    const ParsedAttributesView &AttrList, bool IsInstantiation,
    bool IsUsingIfExists);
NamedDecl *BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS,
                                     SourceLocation UsingLoc,
                                     SourceLocation EnumLoc,
                                     SourceLocation NameLoc, EnumDecl *ED);
NamedDecl *BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
                              ArrayRef<NamedDecl *> Expansions);

bool CheckInheritingConstructorUsingDecl(UsingDecl *UD);

/// Given a derived-class using shadow declaration for a constructor and the
/// correspnding base class constructor, find or create the implicit
/// synthesized derived class constructor to use for this initialization.
CXXConstructorDecl *
findInheritingConstructor(SourceLocation Loc, CXXConstructorDecl *BaseCtor,
                          ConstructorUsingShadowDecl *DerivedShadow);

Decl *ActOnUsingDeclaration(Scope *CurScope, AccessSpecifier AS,
                            SourceLocation UsingLoc,
                            SourceLocation TypenameLoc, CXXScopeSpec &SS,
                            UnqualifiedId &Name, SourceLocation EllipsisLoc,
                            const ParsedAttributesView &AttrList);
Decl *ActOnUsingEnumDeclaration(Scope *CurScope, AccessSpecifier AS,
                                SourceLocation UsingLoc,
                                SourceLocation EnumLoc, const DeclSpec &);
Decl *ActOnAliasDeclaration(Scope *CurScope, AccessSpecifier AS,
                            MultiTemplateParamsArg TemplateParams,
                            SourceLocation UsingLoc, UnqualifiedId &Name,
                            const ParsedAttributesView &AttrList,
                            TypeResult Type, Decl *DeclFromDeclSpec);

/// BuildCXXConstructExpr - Creates a complete call to a constructor,
/// including handling of its default argument expressions.
///
/// \param ConstructKind - a CXXConstructExpr::ConstructionKind
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      NamedDecl *FoundDecl,
                      CXXConstructorDecl *Constructor, MultiExprArg Exprs,
                      bool HadMultipleCandidates, bool IsListInitialization,
                      bool IsStdInitListInitialization,
                      bool RequiresZeroInit, unsigned ConstructKind,
                      SourceRange ParenRange);

/// Build a CXXConstructExpr whose constructor has already been resolved if
/// it denotes an inherited constructor.
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      CXXConstructorDecl *Constructor, bool Elidable,
                      MultiExprArg Exprs,
                      bool HadMultipleCandidates, bool IsListInitialization,
                      bool IsStdInitListInitialization,
                      bool RequiresZeroInit, unsigned ConstructKind,
                      SourceRange ParenRange);

// FIXME: Can we remove this and have the above BuildCXXConstructExpr check if
// the constructor can be elidable?
ExprResult
BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
                      NamedDecl *FoundDecl,
                      CXXConstructorDecl *Constructor, bool Elidable,
                      MultiExprArg Exprs, bool HadMultipleCandidates,
                      bool IsListInitialization,
                      bool IsStdInitListInitialization, bool RequiresZeroInit,
                      unsigned ConstructKind, SourceRange ParenRange);

ExprResult BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field);


/// Instantiate or parse a C++ default argument expression as necessary.
/// Return true on error.
bool CheckCXXDefaultArgExpr(SourceLocation CallLoc, FunctionDecl *FD,
                            ParmVarDecl *Param);

/// BuildCXXDefaultArgExpr - Creates a CXXDefaultArgExpr, instantiating
/// the default expr if needed.
ExprResult BuildCXXDefaultArgExpr(SourceLocation CallLoc,
                                  FunctionDecl *FD,
                                  ParmVarDecl *Param);

/// FinalizeVarWithDestructor - Prepare for calling destructor on the
/// constructed variable.
void FinalizeVarWithDestructor(VarDecl *VD, const RecordType *DeclInitType);

/// Helper class that collects exception specifications for
/// implicitly-declared special member functions.
class ImplicitExceptionSpecification {
  // Pointer to allow copying
  Sema *Self;
  // We order exception specifications thus:
  // noexcept is the most restrictive, but is only used in C++11.
  // throw() comes next.
  // Then a throw(collected exceptions)
  // Finally no specification, which is expressed as noexcept(false).
  // throw(...) is used instead if any called function uses it.
  ExceptionSpecificationType ComputedEST;
  llvm::SmallPtrSet<CanQualType, 4> ExceptionsSeen;
  SmallVector<QualType, 4> Exceptions;

  void ClearExceptions() {
    ExceptionsSeen.clear();
    Exceptions.clear();
  }

public:
  explicit ImplicitExceptionSpecification(Sema &Self)
    : Self(&Self), ComputedEST(EST_BasicNoexcept) {
    if (!Self.getLangOpts().CPlusPlus11)
      ComputedEST = EST_DynamicNone;
  }

  /// Get the computed exception specification type.
  ExceptionSpecificationType getExceptionSpecType() const {
    assert(!isComputedNoexcept(ComputedEST) &&((void)0)
           "noexcept(expr) should not be a possible result")((void)0);
    return ComputedEST;
  }

  /// The number of exceptions in the exception specification.
  unsigned size() const { return Exceptions.size(); }

  /// The set of exceptions in the exception specification.
  const QualType *data() const { return Exceptions.data(); }

  /// Integrate another called method into the collected data.
  void CalledDecl(SourceLocation CallLoc, const CXXMethodDecl *Method);

  /// Integrate an invoked expression into the collected data.
  void CalledExpr(Expr *E) { CalledStmt(E); }

  /// Integrate an invoked statement into the collected data.
  void CalledStmt(Stmt *S);

  /// Overwrite an EPI's exception specification with this
  /// computed exception specification.
  FunctionProtoType::ExceptionSpecInfo getExceptionSpec() const {
    FunctionProtoType::ExceptionSpecInfo ESI;
    ESI.Type = getExceptionSpecType();
    if (ESI.Type == EST_Dynamic) {
      ESI.Exceptions = Exceptions;
    } else if (ESI.Type == EST_None) {
      /// C++11 [except.spec]p14:
      ///   The exception-specification is noexcept(false) if the set of
      ///   potential exceptions of the special member function contains "any"
      ESI.Type = EST_NoexceptFalse;
      ESI.NoexceptExpr = Self->ActOnCXXBoolLiteral(SourceLocation(),
                                                   tok::kw_false).get();
    }
    return ESI;
  }
};

/// Evaluate the implicit exception specification for a defaulted
/// special member function.
void EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD);

/// Check the given noexcept-specifier, convert its expression, and compute
/// the appropriate ExceptionSpecificationType.
ExprResult ActOnNoexceptSpec(SourceLocation NoexceptLoc, Expr *NoexceptExpr,
                             ExceptionSpecificationType &EST);

/// Check the given exception-specification and update the
/// exception specification information with the results.
void checkExceptionSpecification(bool IsTopLevel,
                                 ExceptionSpecificationType EST,
                                 ArrayRef<ParsedType> DynamicExceptions,
                                 ArrayRef<SourceRange> DynamicExceptionRanges,
                                 Expr *NoexceptExpr,
                                 SmallVectorImpl<QualType> &Exceptions,
                                 FunctionProtoType::ExceptionSpecInfo &ESI);

/// Determine if we're in a case where we need to (incorrectly) eagerly
/// parse an exception specification to work around a libstdc++ bug.
bool isLibstdcxxEagerExceptionSpecHack(const Declarator &D);

/// Add an exception-specification to the given member function
/// (or member function template). The exception-specification was parsed
/// after the method itself was declared.
void actOnDelayedExceptionSpecification(Decl *Method,
       ExceptionSpecificationType EST,
       SourceRange SpecificationRange,
       ArrayRef<ParsedType> DynamicExceptions,
       ArrayRef<SourceRange> DynamicExceptionRanges,
       Expr *NoexceptExpr);

class InheritedConstructorInfo;

/// Determine if a special member function should have a deleted
/// definition when it is defaulted.
bool ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
                               InheritedConstructorInfo *ICI = nullptr,
                               bool Diagnose = false);

/// Produce notes explaining why a defaulted function was defined as deleted.
void DiagnoseDeletedDefaultedFunction(FunctionDecl *FD);

/// Declare the implicit default constructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// default constructor will be added.
///
/// \returns The implicitly-declared default constructor.
CXXConstructorDecl *DeclareImplicitDefaultConstructor(
                                                   CXXRecordDecl *ClassDecl);

/// DefineImplicitDefaultConstructor - Checks for feasibility of
/// defining this constructor as the default constructor.
void DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
                                      CXXConstructorDecl *Constructor);

/// Declare the implicit destructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// destructor will be added.
///
/// \returns The implicitly-declared destructor.
CXXDestructorDecl *DeclareImplicitDestructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitDestructor - Checks for feasibility of
/// defining this destructor as the default destructor.
void DefineImplicitDestructor(SourceLocation CurrentLocation,
                              CXXDestructorDecl *Destructor);

/// Build an exception spec for destructors that don't have one.
///
/// C++11 says that user-defined destructors with no exception spec get one
/// that looks as if the destructor was implicitly declared.
void AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor);

/// Define the specified inheriting constructor.
void DefineInheritingConstructor(SourceLocation UseLoc,
                                 CXXConstructorDecl *Constructor);

/// Declare the implicit copy constructor for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// copy constructor will be added.
///
/// \returns The implicitly-declared copy constructor.
CXXConstructorDecl *DeclareImplicitCopyConstructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitCopyConstructor - Checks for feasibility of
/// defining this constructor as the copy constructor.
void DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
                                   CXXConstructorDecl *Constructor);

/// Declare the implicit move constructor for the given class.
///
/// \param ClassDecl The Class declaration into which the implicit
/// move constructor will be added.
///
/// \returns The implicitly-declared move constructor, or NULL if it wasn't
/// declared.
CXXConstructorDecl *DeclareImplicitMoveConstructor(CXXRecordDecl *ClassDecl);

/// DefineImplicitMoveConstructor - Checks for feasibility of
/// defining this constructor as the move constructor.
void DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
                                   CXXConstructorDecl *Constructor);

/// Declare the implicit copy assignment operator for the given class.
///
/// \param ClassDecl The class declaration into which the implicit
/// copy assignment operator will be added.
///
/// \returns The implicitly-declared copy assignment operator.
CXXMethodDecl *DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl);

/// Defines an implicitly-declared copy assignment operator.
void DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
                                  CXXMethodDecl *MethodDecl);

/// Declare the implicit move assignment operator for the given class.
///
/// \param ClassDecl The Class declaration into which the implicit
/// move assignment operator will be added.
///
/// \returns The implicitly-declared move assignment operator, or NULL if it
/// wasn't declared.
CXXMethodDecl *DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl);

/// Defines an implicitly-declared move assignment operator.
void DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
                                  CXXMethodDecl *MethodDecl);

/// Force the declaration of any implicitly-declared members of this
/// class.
void ForceDeclarationOfImplicitMembers(CXXRecordDecl *Class);

/// Check a completed declaration of an implicit special member.
void CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD);

/// Determine whether the given function is an implicitly-deleted
/// special member function.
bool isImplicitlyDeleted(FunctionDecl *FD);

/// Check whether 'this' shows up in the type of a static member
/// function after the (naturally empty) cv-qualifier-seq would be.
///
/// \returns true if an error occurred.
bool checkThisInStaticMemberFunctionType(CXXMethodDecl *Method);

/// Whether this' shows up in the exception specification of a static
/// member function.
bool checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method);

/// Check whether 'this' shows up in the attributes of the given
/// static member function.
///
/// \returns true if an error occurred.
bool checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method);

/// MaybeBindToTemporary - If the passed in expression has a record type with
/// a non-trivial destructor, this will return CXXBindTemporaryExpr. Otherwise
/// it simply returns the passed in expression.
ExprResult MaybeBindToTemporary(Expr *E);

/// Wrap the expression in a ConstantExpr if it is a potential immediate
/// invocation.
ExprResult CheckForImmediateInvocation(ExprResult E, FunctionDecl *Decl);

bool CompleteConstructorCall(CXXConstructorDecl *Constructor,
                             QualType DeclInitType, MultiExprArg ArgsPtr,
                             SourceLocation Loc,
                             SmallVectorImpl<Expr *> &ConvertedArgs,
                             bool AllowExplicit = false,
                             bool IsListInitialization = false);

ParsedType getInheritingConstructorName(CXXScopeSpec &SS,
                                        SourceLocation NameLoc,
                                        IdentifierInfo &Name);

ParsedType getConstructorName(IdentifierInfo &II, SourceLocation NameLoc,
                              Scope *S, CXXScopeSpec &SS,
                              bool EnteringContext);
ParsedType getDestructorName(SourceLocation TildeLoc,
                             IdentifierInfo &II, SourceLocation NameLoc,
                             Scope *S, CXXScopeSpec &SS,
                             ParsedType ObjectType,
                             bool EnteringContext);

ParsedType getDestructorTypeForDecltype(const DeclSpec &DS,
                                        ParsedType ObjectType);

// Checks that reinterpret casts don't have undefined behavior.
void CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
                                    bool IsDereference, SourceRange Range);

// Checks that the vector type should be initialized from a scalar
// by splatting the value rather than populating a single element.
// This is the case for AltiVecVector types as well as with
// AltiVecPixel and AltiVecBool when -faltivec-src-compat=xl is specified.
bool ShouldSplatAltivecScalarInCast(const VectorType *VecTy);

/// ActOnCXXNamedCast - Parse
/// {dynamic,static,reinterpret,const,addrspace}_cast's.
ExprResult ActOnCXXNamedCast(SourceLocation OpLoc,
                             tok::TokenKind Kind,
                             SourceLocation LAngleBracketLoc,
                             Declarator &D,
                             SourceLocation RAngleBracketLoc,
                             SourceLocation LParenLoc,
                             Expr *E,
                             SourceLocation RParenLoc);

ExprResult BuildCXXNamedCast(SourceLocation OpLoc,
                             tok::TokenKind Kind,
                             TypeSourceInfo *Ty,
                             Expr *E,
                             SourceRange AngleBrackets,
                             SourceRange Parens);

ExprResult ActOnBuiltinBitCastExpr(SourceLocation KWLoc, Declarator &Dcl,
                                   ExprResult Operand,
                                   SourceLocation RParenLoc);

ExprResult BuildBuiltinBitCastExpr(SourceLocation KWLoc, TypeSourceInfo *TSI,
                                   Expr *Operand, SourceLocation RParenLoc);

ExprResult BuildCXXTypeId(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          TypeSourceInfo *Operand,
                          SourceLocation RParenLoc);
ExprResult BuildCXXTypeId(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          Expr *Operand,
                          SourceLocation RParenLoc);

/// ActOnCXXTypeid - Parse typeid( something ).
ExprResult ActOnCXXTypeid(SourceLocation OpLoc,
                          SourceLocation LParenLoc, bool isType,
                          void *TyOrExpr,
                          SourceLocation RParenLoc);

ExprResult BuildCXXUuidof(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          TypeSourceInfo *Operand,
                          SourceLocation RParenLoc);
ExprResult BuildCXXUuidof(QualType TypeInfoType,
                          SourceLocation TypeidLoc,
                          Expr *Operand,
                          SourceLocation RParenLoc);

/// ActOnCXXUuidof - Parse __uuidof( something ).
ExprResult ActOnCXXUuidof(SourceLocation OpLoc,
                          SourceLocation LParenLoc, bool isType,
                          void *TyOrExpr,
                          SourceLocation RParenLoc);

/// Handle a C++1z fold-expression: ( expr op ... op expr ).
ExprResult ActOnCXXFoldExpr(Scope *S, SourceLocation LParenLoc, Expr *LHS,
                            tok::TokenKind Operator,
                            SourceLocation EllipsisLoc, Expr *RHS,
                            SourceLocation RParenLoc);
ExprResult BuildCXXFoldExpr(UnresolvedLookupExpr *Callee,
                            SourceLocation LParenLoc, Expr *LHS,
                            BinaryOperatorKind Operator,
                            SourceLocation EllipsisLoc, Expr *RHS,
                            SourceLocation RParenLoc,
                            Optional<unsigned> NumExpansions);
ExprResult BuildEmptyCXXFoldExpr(SourceLocation EllipsisLoc,
                                 BinaryOperatorKind Operator);

//// ActOnCXXThis -  Parse 'this' pointer.
ExprResult ActOnCXXThis(SourceLocation loc);

/// Build a CXXThisExpr and mark it referenced in the current context.
Expr *BuildCXXThisExpr(SourceLocation Loc, QualType Type, bool IsImplicit);
void MarkThisReferenced(CXXThisExpr *This);

/// Try to retrieve the type of the 'this' pointer.
///
/// \returns The type of 'this', if possible. Otherwise, returns a NULL type.
QualType getCurrentThisType();

/// When non-NULL, the C++ 'this' expression is allowed despite the
/// current context not being a non-static member function. In such cases,
/// this provides the type used for 'this'.
QualType CXXThisTypeOverride;

/// RAII object used to temporarily allow the C++ 'this' expression
/// to be used, with the given qualifiers on the current class type.
class CXXThisScopeRAII {
  Sema &S;
  QualType OldCXXThisTypeOverride;
  bool Enabled;

public:
  /// Introduce a new scope where 'this' may be allowed (when enabled),
  /// using the given declaration (which is either a class template or a
  /// class) along with the given qualifiers.
  /// along with the qualifiers placed on '*this'.
  CXXThisScopeRAII(Sema &S, Decl *ContextDecl, Qualifiers CXXThisTypeQuals,
                   bool Enabled = true);

  ~CXXThisScopeRAII();
};

/// Make sure the value of 'this' is actually available in the current
/// context, if it is a potentially evaluated context.
///
/// \param Loc The location at which the capture of 'this' occurs.
///
/// \param Explicit Whether 'this' is explicitly captured in a lambda
/// capture list.
///
/// \param FunctionScopeIndexToStopAt If non-null, it points to the index
/// of the FunctionScopeInfo stack beyond which we do not attempt to capture.
/// This is useful when enclosing lambdas must speculatively capture
/// 'this' that may or may not be used in certain specializations of
/// a nested generic lambda (depending on whether the name resolves to
/// a non-static member function or a static function).
/// \return returns 'true' if failed, 'false' if success.
bool CheckCXXThisCapture(SourceLocation Loc, bool Explicit = false,
    bool BuildAndDiagnose = true,
    const unsigned *const FunctionScopeIndexToStopAt = nullptr,
    bool ByCopy = false);

/// Determine whether the given type is the type of *this that is used
/// outside of the body of a member function for a type that is currently
/// being defined.
bool isThisOutsideMemberFunctionBody(QualType BaseType);

/// ActOnCXXBoolLiteral - Parse {true,false} literals.
ExprResult ActOnCXXBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);


/// ActOnObjCBoolLiteral - Parse {__objc_yes,__objc_no} literals.
ExprResult ActOnObjCBoolLiteral(SourceLocation OpLoc, tok::TokenKind Kind);

ExprResult
ActOnObjCAvailabilityCheckExpr(llvm::ArrayRef<AvailabilitySpec> AvailSpecs,
                               SourceLocation AtLoc, SourceLocation RParen);

/// ActOnCXXNullPtrLiteral - Parse 'nullptr'.
ExprResult ActOnCXXNullPtrLiteral(SourceLocation Loc);

//// ActOnCXXThrow -  Parse throw expressions.
ExprResult ActOnCXXThrow(Scope *S, SourceLocation OpLoc, Expr *expr);
ExprResult BuildCXXThrow(SourceLocation OpLoc, Expr *Ex,
                         bool IsThrownVarInScope);
bool CheckCXXThrowOperand(SourceLocation ThrowLoc, QualType ThrowTy, Expr *E);

/// ActOnCXXTypeConstructExpr - Parse construction of a specified type.
/// Can be interpreted either as function-style casting ("int(x)")
/// or class type construction ("ClassType(x,y,z)")
/// or creation of a value-initialized type ("int()").
ExprResult ActOnCXXTypeConstructExpr(ParsedType TypeRep,
                                     SourceLocation LParenOrBraceLoc,
                                     MultiExprArg Exprs,
                                     SourceLocation RParenOrBraceLoc,
                                     bool ListInitialization);

ExprResult BuildCXXTypeConstructExpr(TypeSourceInfo *Type,
                                     SourceLocation LParenLoc,
                                     MultiExprArg Exprs,
                                     SourceLocation RParenLoc,
                                     bool ListInitialization);

/// ActOnCXXNew - Parsed a C++ 'new' expression.
ExprResult ActOnCXXNew(SourceLocation StartLoc, bool UseGlobal,
                       SourceLocation PlacementLParen,
                       MultiExprArg PlacementArgs,
                       SourceLocation PlacementRParen,
                       SourceRange TypeIdParens, Declarator &D,
                       Expr *Initializer);
ExprResult BuildCXXNew(SourceRange Range, bool UseGlobal,
                       SourceLocation PlacementLParen,
                       MultiExprArg PlacementArgs,
                       SourceLocation PlacementRParen,
                       SourceRange TypeIdParens,
                       QualType AllocType,
                       TypeSourceInfo *AllocTypeInfo,
                       Optional<Expr *> ArraySize,
                       SourceRange DirectInitRange,
                       Expr *Initializer);

/// Determine whether \p FD is an aligned allocation or deallocation
/// function that is unavailable.
bool isUnavailableAlignedAllocationFunction(const FunctionDecl &FD) const;

/// Produce diagnostics if \p FD is an aligned allocation or deallocation
/// function that is unavailable.
void diagnoseUnavailableAlignedAllocation(const FunctionDecl &FD,
                                          SourceLocation Loc);

bool CheckAllocatedType(QualType AllocType, SourceLocation Loc,
                        SourceRange R);

/// The scope in which to find allocation functions.
enum AllocationFunctionScope {
  /// Only look for allocation functions in the global scope.
  AFS_Global,
  /// Only look for allocation functions in the scope of the
  /// allocated class.
  AFS_Class,
  /// Look for allocation functions in both the global scope
  /// and in the scope of the allocated class.
  AFS_Both
};

/// Finds the overloads of operator new and delete that are appropriate
/// for the allocation.
bool FindAllocationFunctions(SourceLocation StartLoc, SourceRange Range,
                             AllocationFunctionScope NewScope,
                             AllocationFunctionScope DeleteScope,
                             QualType AllocType, bool IsArray,
                             bool &PassAlignment, MultiExprArg PlaceArgs,
                             FunctionDecl *&OperatorNew,
                             FunctionDecl *&OperatorDelete,
                             bool Diagnose = true);
void DeclareGlobalNewDelete();
void DeclareGlobalAllocationFunction(DeclarationName Name, QualType Return,
                                     ArrayRef<QualType> Params);

bool FindDeallocationFunction(SourceLocation StartLoc, CXXRecordDecl *RD,
                              DeclarationName Name, FunctionDecl* &Operator,
                              bool Diagnose = true);
FunctionDecl *FindUsualDeallocationFunction(SourceLocation StartLoc,
                                            bool CanProvideSize,
                                            bool Overaligned,
                                            DeclarationName Name);
FunctionDecl *FindDeallocationFunctionForDestructor(SourceLocation StartLoc,
                                                    CXXRecordDecl *RD);

/// ActOnCXXDelete - Parsed a C++ 'delete' expression
ExprResult ActOnCXXDelete(SourceLocation StartLoc,
                          bool UseGlobal, bool ArrayForm,
                          Expr *Operand);
void CheckVirtualDtorCall(CXXDestructorDecl *dtor, SourceLocation Loc,
                          bool IsDelete, bool CallCanBeVirtual,
                          bool WarnOnNonAbstractTypes,
                          SourceLocation DtorLoc);

ExprResult ActOnNoexceptExpr(SourceLocation KeyLoc, SourceLocation LParen,
                             Expr *Operand, SourceLocation RParen);
ExprResult BuildCXXNoexceptExpr(SourceLocation KeyLoc, Expr *Operand,
                                SourceLocation RParen);

/// Parsed one of the type trait support pseudo-functions.
ExprResult ActOnTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                          ArrayRef<ParsedType> Args,
                          SourceLocation RParenLoc);
ExprResult BuildTypeTrait(TypeTrait Kind, SourceLocation KWLoc,
                          ArrayRef<TypeSourceInfo *> Args,
                          SourceLocation RParenLoc);

/// ActOnArrayTypeTrait - Parsed one of the binary type trait support
/// pseudo-functions.
ExprResult ActOnArrayTypeTrait(ArrayTypeTrait ATT,
                               SourceLocation KWLoc,
                               ParsedType LhsTy,
                               Expr *DimExpr,
                               SourceLocation RParen);

ExprResult BuildArrayTypeTrait(ArrayTypeTrait ATT,
                               SourceLocation KWLoc,
                               TypeSourceInfo *TSInfo,
                               Expr *DimExpr,
                               SourceLocation RParen);

/// ActOnExpressionTrait - Parsed one of the unary type trait support
/// pseudo-functions.
ExprResult ActOnExpressionTrait(ExpressionTrait OET,
                                SourceLocation KWLoc,
                                Expr *Queried,
                                SourceLocation RParen);

ExprResult BuildExpressionTrait(ExpressionTrait OET,
                                SourceLocation KWLoc,
                                Expr *Queried,
                                SourceLocation RParen);

ExprResult ActOnStartCXXMemberReference(Scope *S,
                                        Expr *Base,
                                        SourceLocation OpLoc,
                                        tok::TokenKind OpKind,
                                        ParsedType &ObjectType,
                                        bool &MayBePseudoDestructor);

ExprResult BuildPseudoDestructorExpr(Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     const CXXScopeSpec &SS,
                                     TypeSourceInfo *ScopeType,
                                     SourceLocation CCLoc,
                                     SourceLocation TildeLoc,
                                   PseudoDestructorTypeStorage DestroyedType);

ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     CXXScopeSpec &SS,
                                     UnqualifiedId &FirstTypeName,
                                     SourceLocation CCLoc,
                                     SourceLocation TildeLoc,
                                     UnqualifiedId &SecondTypeName);

ExprResult ActOnPseudoDestructorExpr(Scope *S, Expr *Base,
                                     SourceLocation OpLoc,
                                     tok::TokenKind OpKind,
                                     SourceLocation TildeLoc,
                                     const DeclSpec& DS);

/// MaybeCreateExprWithCleanups - If the current full-expression
/// requires any cleanups, surround it with a ExprWithCleanups node.
/// Otherwise, just returns the passed-in expression.
Expr *MaybeCreateExprWithCleanups(Expr *SubExpr);
Stmt *MaybeCreateStmtWithCleanups(Stmt *SubStmt);
ExprResult MaybeCreateExprWithCleanups(ExprResult SubExpr);

MaterializeTemporaryExpr *
CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary,
                               bool BoundToLvalueReference);

ExprResult ActOnFinishFullExpr(Expr *Expr, bool DiscardedValue) {
  return ActOnFinishFullExpr(
      Expr, Expr ? Expr->getExprLoc() : SourceLocation(), DiscardedValue);
}
ExprResult ActOnFinishFullExpr(Expr *Expr, SourceLocation CC,
                               bool DiscardedValue, bool IsConstexpr = false);
StmtResult ActOnFinishFullStmt(Stmt *Stmt);

// Marks SS invalid if it represents an incomplete type.
bool RequireCompleteDeclContext(CXXScopeSpec &SS, DeclContext *DC);
// Complete an enum decl, maybe without a scope spec.
bool RequireCompleteEnumDecl(EnumDecl *D, SourceLocation L,
                             CXXScopeSpec *SS = nullptr);

DeclContext *computeDeclContext(QualType T);
DeclContext *computeDeclContext(const CXXScopeSpec &SS,
                                bool EnteringContext = false);
bool isDependentScopeSpecifier(const CXXScopeSpec &SS);
CXXRecordDecl *getCurrentInstantiationOf(NestedNameSpecifier *NNS);

/// The parser has parsed a global nested-name-specifier '::'.
///
/// \param CCLoc The location of the '::'.
///
/// \param SS The nested-name-specifier, which will be updated in-place
/// to reflect the parsed nested-name-specifier.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXGlobalScopeSpecifier(SourceLocation CCLoc, CXXScopeSpec &SS);

/// The parser has parsed a '__super' nested-name-specifier.
///
/// \param SuperLoc The location of the '__super' keyword.
///
/// \param ColonColonLoc The location of the '::'.
///
/// \param SS The nested-name-specifier, which will be updated in-place
/// to reflect the parsed nested-name-specifier.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnSuperScopeSpecifier(SourceLocation SuperLoc,
                              SourceLocation ColonColonLoc, CXXScopeSpec &SS);

bool isAcceptableNestedNameSpecifier(const NamedDecl *SD,
                                     bool *CanCorrect = nullptr);
NamedDecl *FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS);

/// Keeps information about an identifier in a nested-name-spec.
///
struct NestedNameSpecInfo {
  /// The type of the object, if we're parsing nested-name-specifier in
  /// a member access expression.
  ParsedType ObjectType;

  /// The identifier preceding the '::'.
  IdentifierInfo *Identifier;

  /// The location of the identifier.
  SourceLocation IdentifierLoc;

  /// The location of the '::'.
  SourceLocation CCLoc;

  /// Creates info object for the most typical case.
  NestedNameSpecInfo(IdentifierInfo *II, SourceLocation IdLoc,
           SourceLocation ColonColonLoc, ParsedType ObjectType = ParsedType())
    : ObjectType(ObjectType), Identifier(II), IdentifierLoc(IdLoc),
      CCLoc(ColonColonLoc) {
  }

  NestedNameSpecInfo(IdentifierInfo *II, SourceLocation IdLoc,
                     SourceLocation ColonColonLoc, QualType ObjectType)
    : ObjectType(ParsedType::make(ObjectType)), Identifier(II),
      IdentifierLoc(IdLoc), CCLoc(ColonColonLoc) {
  }
};

bool isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
                                  NestedNameSpecInfo &IdInfo);

bool BuildCXXNestedNameSpecifier(Scope *S,
                                 NestedNameSpecInfo &IdInfo,
                                 bool EnteringContext,
                                 CXXScopeSpec &SS,
                                 NamedDecl *ScopeLookupResult,
                                 bool ErrorRecoveryLookup,
                                 bool *IsCorrectedToColon = nullptr,
                                 bool OnlyNamespace = false);

/// The parser has parsed a nested-name-specifier 'identifier::'.
///
/// \param S The scope in which this nested-name-specifier occurs.
///
/// \param IdInfo Parser information about an identifier in the
/// nested-name-spec.
///
/// \param EnteringContext Whether we're entering the context nominated by
/// this nested-name-specifier.
///
/// \param SS The nested-name-specifier, which is both an input
/// parameter (the nested-name-specifier before this type) and an
/// output parameter (containing the full nested-name-specifier,
/// including this new type).
///
/// \param ErrorRecoveryLookup If true, then this method is called to improve
/// error recovery. In this case do not emit error message.
///
/// \param IsCorrectedToColon If not null, suggestions to replace '::' -> ':'
/// are allowed.  The bool value pointed by this parameter is set to 'true'
/// if the identifier is treated as if it was followed by ':', not '::'.
///
/// \param OnlyNamespace If true, only considers namespaces in lookup.
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXNestedNameSpecifier(Scope *S,
                                 NestedNameSpecInfo &IdInfo,
                                 bool EnteringContext,
                                 CXXScopeSpec &SS,
                                 bool ErrorRecoveryLookup = false,
                                 bool *IsCorrectedToColon = nullptr,
                                 bool OnlyNamespace = false);

ExprResult ActOnDecltypeExpression(Expr *E);

bool ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
                                         const DeclSpec &DS,
                                         SourceLocation ColonColonLoc);

bool IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
                               NestedNameSpecInfo &IdInfo,
                               bool EnteringContext);

/// The parser has parsed a nested-name-specifier
/// 'template[opt] template-name < template-args >::'.
///
/// \param S The scope in which this nested-name-specifier occurs.
///
/// \param SS The nested-name-specifier, which is both an input
/// parameter (the nested-name-specifier before this type) and an
/// output parameter (containing the full nested-name-specifier,
/// including this new type).
///
/// \param TemplateKWLoc the location of the 'template' keyword, if any.
/// \param TemplateName the template name.
/// \param TemplateNameLoc The location of the template name.
/// \param LAngleLoc The location of the opening angle bracket  ('<').
/// \param TemplateArgs The template arguments.
/// \param RAngleLoc The location of the closing angle bracket  ('>').
/// \param CCLoc The location of the '::'.
///
/// \param EnteringContext Whether we're entering the context of the
/// nested-name-specifier.
///
///
/// \returns true if an error occurred, false otherwise.
bool ActOnCXXNestedNameSpecifier(Scope *S,
                                 CXXScopeSpec &SS,
                                 SourceLocation TemplateKWLoc,
                                 TemplateTy TemplateName,
                                 SourceLocation TemplateNameLoc,
                                 SourceLocation LAngleLoc,
                                 ASTTemplateArgsPtr TemplateArgs,
                                 SourceLocation RAngleLoc,
                                 SourceLocation CCLoc,
                                 bool EnteringContext);

/// Given a C++ nested-name-specifier, produce an annotation value
/// that the parser can use later to reconstruct the given
/// nested-name-specifier.
///
/// \param SS A nested-name-specifier.
///
/// \returns A pointer containing all of the information in the
/// nested-name-specifier \p SS.
void *SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS);

/// Given an annotation pointer for a nested-name-specifier, restore
/// the nested-name-specifier structure.
///
/// \param Annotation The annotation pointer, produced by
/// \c SaveNestedNameSpecifierAnnotation().
///
/// \param AnnotationRange The source range corresponding to the annotation.
///
/// \param SS The nested-name-specifier that will be updated with the contents
/// of the annotation pointer.
void RestoreNestedNameSpecifierAnnotation(void *Annotation,
                                          SourceRange AnnotationRange,
                                          CXXScopeSpec &SS);

bool ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS);

/// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
/// scope or nested-name-specifier) is parsed, part of a declarator-id.
/// After this method is called, according to [C++ 3.4.3p3], names should be
/// looked up in the declarator-id's scope, until the declarator is parsed and
/// ActOnCXXExitDeclaratorScope is called.
/// The 'SS' should be a non-empty valid CXXScopeSpec.
bool ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS);

/// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
/// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
/// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
/// Used to indicate that names should revert to being looked up in the
/// defining scope.
void ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS);

/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
/// initializer for the declaration 'Dcl'.
/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
/// static data member of class X, names should be looked up in the scope of
/// class X.
void ActOnCXXEnterDeclInitializer(Scope *S, Decl *Dcl);

/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
/// initializer for the declaration 'Dcl'.
void ActOnCXXExitDeclInitializer(Scope *S, Decl *Dcl);

/// Create a new lambda closure type.
CXXRecordDecl *createLambdaClosureType(SourceRange IntroducerRange,
                                       TypeSourceInfo *Info,
                                       bool KnownDependent,
                                       LambdaCaptureDefault CaptureDefault);

/// Start the definition of a lambda expression.
CXXMethodDecl *startLambdaDefinition(CXXRecordDecl *Class,
                                     SourceRange IntroducerRange,
                                     TypeSourceInfo *MethodType,
                                     SourceLocation EndLoc,
                                     ArrayRef<ParmVarDecl *> Params,
                                     ConstexprSpecKind ConstexprKind,
                                     Expr *TrailingRequiresClause);

/// Number lambda for linkage purposes if necessary.
void handleLambdaNumbering(
    CXXRecordDecl *Class, CXXMethodDecl *Method,
    Optional<std::tuple<bool, unsigned, unsigned, Decl *>> Mangling = None);

/// Endow the lambda scope info with the relevant properties.
void buildLambdaScope(sema::LambdaScopeInfo *LSI,
                      CXXMethodDecl *CallOperator,
                      SourceRange IntroducerRange,
                      LambdaCaptureDefault CaptureDefault,
                      SourceLocation CaptureDefaultLoc,
                      bool ExplicitParams,
                      bool ExplicitResultType,
                      bool Mutable);

/// Perform initialization analysis of the init-capture and perform
/// any implicit conversions such as an lvalue-to-rvalue conversion if
/// not being used to initialize a reference.
ParsedType actOnLambdaInitCaptureInitialization(
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
    IdentifierInfo *Id, LambdaCaptureInitKind InitKind, Expr *&Init) {
  return ParsedType::make(buildLambdaInitCaptureInitialization(
      Loc, ByRef, EllipsisLoc, None, Id,
      InitKind != LambdaCaptureInitKind::CopyInit, Init));
}
QualType buildLambdaInitCaptureInitialization(
    SourceLocation Loc, bool ByRef, SourceLocation EllipsisLoc,
    Optional<unsigned> NumExpansions, IdentifierInfo *Id, bool DirectInit,
    Expr *&Init);

/// Create a dummy variable within the declcontext of the lambda's
///  call operator, for name lookup purposes for a lambda init capture.
///
///  CodeGen handles emission of lambda captures, ignoring these dummy
///  variables appropriately.
VarDecl *createLambdaInitCaptureVarDecl(SourceLocation Loc,
                                        QualType InitCaptureType,
                                        SourceLocation EllipsisLoc,
                                        IdentifierInfo *Id,
                                        unsigned InitStyle, Expr *Init);

/// Add an init-capture to a lambda scope.
void addInitCapture(sema::LambdaScopeInfo *LSI, VarDecl *Var);

/// Note that we have finished the explicit captures for the
/// given lambda.
void finishLambdaExplicitCaptures(sema::LambdaScopeInfo *LSI);

/// \brief This is called after parsing the explicit template parameter list
/// on a lambda (if it exists) in C++2a.
void ActOnLambdaExplicitTemplateParameterList(SourceLocation LAngleLoc,
                                              ArrayRef<NamedDecl *> TParams,
                                              SourceLocation RAngleLoc,
                                              ExprResult RequiresClause);

/// Introduce the lambda parameters into scope.
void addLambdaParameters(
    ArrayRef<LambdaIntroducer::LambdaCapture> Captures,
    CXXMethodDecl *CallOperator, Scope *CurScope);

/// Deduce a block or lambda's return type based on the return
/// statements present in the body.
void deduceClosureReturnType(sema::CapturingScopeInfo &CSI);

/// ActOnStartOfLambdaDefinition - This is called just before we start
/// parsing the body of a lambda; it analyzes the explicit captures and
/// arguments, and sets up various data-structures for the body of the
/// lambda.
void ActOnStartOfLambdaDefinition(LambdaIntroducer &Intro,
                                  Declarator &ParamInfo, Scope *CurScope);

/// ActOnLambdaError - If there is an error parsing a lambda, this callback
/// is invoked to pop the information about the lambda.
void ActOnLambdaError(SourceLocation StartLoc, Scope *CurScope,
                      bool IsInstantiation = false);

/// ActOnLambdaExpr - This is called when the body of a lambda expression
/// was successfully completed.
ExprResult ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body,
                           Scope *CurScope);

/// Does copying/destroying the captured variable have side effects?
bool CaptureHasSideEffects(const sema::Capture &From);

/// Diagnose if an explicit lambda capture is unused. Returns true if a
/// diagnostic is emitted.
bool DiagnoseUnusedLambdaCapture(SourceRange CaptureRange,
                                 const sema::Capture &From);

/// Build a FieldDecl suitable to hold the given capture.
FieldDecl *BuildCaptureField(RecordDecl *RD, const sema::Capture &Capture);

/// Initialize the given capture with a suitable expression.
ExprResult BuildCaptureInit(const sema::Capture &Capture,
                            SourceLocation ImplicitCaptureLoc,
                            bool IsOpenMPMapping = false);

/// Complete a lambda-expression having processed and attached the
/// lambda body.
ExprResult BuildLambdaExpr(SourceLocation StartLoc, SourceLocation EndLoc,
                           sema::LambdaScopeInfo *LSI);

/// Get the return type to use for a lambda's conversion function(s) to
/// function pointer type, given the type of the call operator.
QualType
getLambdaConversionFunctionResultType(const FunctionProtoType *CallOpType,
                                      CallingConv CC);

/// Define the "body" of the conversion from a lambda object to a
/// function pointer.
///
/// This routine doesn't actually define a sensible body; rather, it fills
/// in the initialization expression needed to copy the lambda object into
/// the block, and IR generation actually generates the real body of the
/// block pointer conversion.
void DefineImplicitLambdaToFunctionPointerConversion(
       SourceLocation CurrentLoc, CXXConversionDecl *Conv);

/// Define the "body" of the conversion from a lambda object to a
/// block pointer.
///
/// This routine doesn't actually define a sensible body; rather, it fills
/// in the initialization expression needed to copy the lambda object into
/// the block, and IR generation actually generates the real body of the
/// block pointer conversion.
void DefineImplicitLambdaToBlockPointerConversion(SourceLocation CurrentLoc,
                                                  CXXConversionDecl *Conv);

ExprResult BuildBlockForLambdaConversion(SourceLocation CurrentLocation,
                                         SourceLocation ConvLocation,
                                         CXXConversionDecl *Conv,
                                         Expr *Src);

/// Check whether the given expression is a valid constraint expression.
/// A diagnostic is emitted if it is not, false is returned, and
/// PossibleNonPrimary will be set to true if the failure might be due to a
/// non-primary expression being used as an atomic constraint.
bool CheckConstraintExpression(const Expr *CE, Token NextToken = Token(),
                               bool *PossibleNonPrimary = nullptr,
                               bool IsTrailingRequiresClause = false);

6803private:
/// Caches pairs of template-like decls whose associated constraints were
/// checked for subsumption and whether or not the first's constraints did in
/// fact subsume the second's.
llvm::DenseMap<std::pair<NamedDecl *, NamedDecl *>, bool> SubsumptionCache;
/// Caches the normalized associated constraints of declarations (concepts or
/// constrained declarations). If an error occurred while normalizing the
/// associated constraints of the template or concept, nullptr will be cached
/// here.
llvm::DenseMap<NamedDecl *, NormalizedConstraint *>
    NormalizationCache;

llvm::ContextualFoldingSet<ConstraintSatisfaction, const ASTContext &>
    SatisfactionCache;

6818public:
const NormalizedConstraint *
getNormalizedAssociatedConstraints(
    NamedDecl *ConstrainedDecl, ArrayRef<const Expr *> AssociatedConstraints);

/// \brief Check whether the given declaration's associated constraints are
/// at least as constrained than another declaration's according to the
/// partial ordering of constraints.
///
/// \param Result If no error occurred, receives the result of true if D1 is
/// at least constrained than D2, and false otherwise.
///
/// \returns true if an error occurred, false otherwise.
bool IsAtLeastAsConstrained(NamedDecl *D1, ArrayRef<const Expr *> AC1,
                            NamedDecl *D2, ArrayRef<const Expr *> AC2,
                            bool &Result);

/// If D1 was not at least as constrained as D2, but would've been if a pair
/// of atomic constraints involved had been declared in a concept and not
/// repeated in two separate places in code.
/// \returns true if such a diagnostic was emitted, false otherwise.
bool MaybeEmitAmbiguousAtomicConstraintsDiagnostic(NamedDecl *D1,
    ArrayRef<const Expr *> AC1, NamedDecl *D2, ArrayRef<const Expr *> AC2);

/// \brief Check whether the given list of constraint expressions are
/// satisfied (as if in a 'conjunction') given template arguments.
/// \param Template the template-like entity that triggered the constraints
/// check (either a concept or a constrained entity).
/// \param ConstraintExprs a list of constraint expressions, treated as if
/// they were 'AND'ed together.
/// \param TemplateArgs the list of template arguments to substitute into the
/// constraint expression.
/// \param TemplateIDRange The source range of the template id that
/// caused the constraints check.
/// \param Satisfaction if true is returned, will contain details of the
/// satisfaction, with enough information to diagnose an unsatisfied
/// expression.
/// \returns true if an error occurred and satisfaction could not be checked,
/// false otherwise.
bool CheckConstraintSatisfaction(
    const NamedDecl *Template, ArrayRef<const Expr *> ConstraintExprs,
    ArrayRef<TemplateArgument> TemplateArgs,
    SourceRange TemplateIDRange, ConstraintSatisfaction &Satisfaction);

/// \brief Check whether the given non-dependent constraint expression is
/// satisfied. Returns false and updates Satisfaction with the satisfaction
/// verdict if successful, emits a diagnostic and returns true if an error
/// occured and satisfaction could not be determined.
///
/// \returns true if an error occurred, false otherwise.
bool CheckConstraintSatisfaction(const Expr *ConstraintExpr,
                                 ConstraintSatisfaction &Satisfaction);

/// Check whether the given function decl's trailing requires clause is
/// satisfied, if any. Returns false and updates Satisfaction with the
/// satisfaction verdict if successful, emits a diagnostic and returns true if
/// an error occured and satisfaction could not be determined.
///
/// \returns true if an error occurred, false otherwise.
bool CheckFunctionConstraints(const FunctionDecl *FD,
                              ConstraintSatisfaction &Satisfaction,
                              SourceLocation UsageLoc = SourceLocation());


/// \brief Ensure that the given template arguments satisfy the constraints
/// associated with the given template, emitting a diagnostic if they do not.
///
/// \param Template The template to which the template arguments are being
/// provided.
///
/// \param TemplateArgs The converted, canonicalized template arguments.
///
/// \param TemplateIDRange The source range of the template id that
/// caused the constraints check.
///
/// \returns true if the constrains are not satisfied or could not be checked
/// for satisfaction, false if the constraints are satisfied.
bool EnsureTemplateArgumentListConstraints(TemplateDecl *Template,
                                     ArrayRef<TemplateArgument> TemplateArgs,
                                           SourceRange TemplateIDRange);

/// \brief Emit diagnostics explaining why a constraint expression was deemed
/// unsatisfied.
/// \param First whether this is the first time an unsatisfied constraint is
/// diagnosed for this error.
void
DiagnoseUnsatisfiedConstraint(const ConstraintSatisfaction &Satisfaction,
                              bool First = true);

/// \brief Emit diagnostics explaining why a constraint expression was deemed
/// unsatisfied.
void
DiagnoseUnsatisfiedConstraint(const ASTConstraintSatisfaction &Satisfaction,
                              bool First = true);

// ParseObjCStringLiteral - Parse Objective-C string literals.
ExprResult ParseObjCStringLiteral(SourceLocation *AtLocs,
                                  ArrayRef<Expr *> Strings);

ExprResult BuildObjCStringLiteral(SourceLocation AtLoc, StringLiteral *S);

/// BuildObjCNumericLiteral - builds an ObjCBoxedExpr AST node for the
/// numeric literal expression. Type of the expression will be "NSNumber *"
/// or "id" if NSNumber is unavailable.
ExprResult BuildObjCNumericLiteral(SourceLocation AtLoc, Expr *Number);
ExprResult ActOnObjCBoolLiteral(SourceLocation AtLoc, SourceLocation ValueLoc,
                                bool Value);
ExprResult BuildObjCArrayLiteral(SourceRange SR, MultiExprArg Elements);

/// BuildObjCBoxedExpr - builds an ObjCBoxedExpr AST node for the
/// '@' prefixed parenthesized expression. The type of the expression will
/// either be "NSNumber *", "NSString *" or "NSValue *" depending on the type
/// of ValueType, which is allowed to be a built-in numeric type, "char *",
/// "const char *" or C structure with attribute 'objc_boxable'.
ExprResult BuildObjCBoxedExpr(SourceRange SR, Expr *ValueExpr);

ExprResult BuildObjCSubscriptExpression(SourceLocation RB, Expr *BaseExpr,
                                        Expr *IndexExpr,
                                        ObjCMethodDecl *getterMethod,
                                        ObjCMethodDecl *setterMethod);

ExprResult BuildObjCDictionaryLiteral(SourceRange SR,
                             MutableArrayRef<ObjCDictionaryElement> Elements);

ExprResult BuildObjCEncodeExpression(SourceLocation AtLoc,
                                TypeSourceInfo *EncodedTypeInfo,
                                SourceLocation RParenLoc);
ExprResult BuildCXXMemberCallExpr(Expr *Exp, NamedDecl *FoundDecl,
                                  CXXConversionDecl *Method,
                                  bool HadMultipleCandidates);

ExprResult ParseObjCEncodeExpression(SourceLocation AtLoc,
                                     SourceLocation EncodeLoc,
                                     SourceLocation LParenLoc,
                                     ParsedType Ty,
                                     SourceLocation RParenLoc);

/// ParseObjCSelectorExpression - Build selector expression for \@selector
ExprResult ParseObjCSelectorExpression(Selector Sel,
                                       SourceLocation AtLoc,
                                       SourceLocation SelLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation RParenLoc,
                                       bool WarnMultipleSelectors);

/// ParseObjCProtocolExpression - Build protocol expression for \@protocol
ExprResult ParseObjCProtocolExpression(IdentifierInfo * ProtocolName,
                                       SourceLocation AtLoc,
                                       SourceLocation ProtoLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation ProtoIdLoc,
                                       SourceLocation RParenLoc);

//===--------------------------------------------------------------------===//
// C++ Declarations
//
Decl *ActOnStartLinkageSpecification(Scope *S,
                                     SourceLocation ExternLoc,
                                     Expr *LangStr,
                                     SourceLocation LBraceLoc);
Decl *ActOnFinishLinkageSpecification(Scope *S,
                                      Decl *LinkageSpec,
                                      SourceLocation RBraceLoc);


//===--------------------------------------------------------------------===//
// C++ Classes
//
CXXRecordDecl *getCurrentClass(Scope *S, const CXXScopeSpec *SS);
bool isCurrentClassName(const IdentifierInfo &II, Scope *S,
                        const CXXScopeSpec *SS = nullptr);
bool isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS);

bool ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
                          SourceLocation ColonLoc,
                          const ParsedAttributesView &Attrs);

NamedDecl *ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS,
                               Declarator &D,
                               MultiTemplateParamsArg TemplateParameterLists,
                               Expr *BitfieldWidth, const VirtSpecifiers &VS,
                               InClassInitStyle InitStyle);

void ActOnStartCXXInClassMemberInitializer();
void ActOnFinishCXXInClassMemberInitializer(Decl *VarDecl,
                                            SourceLocation EqualLoc,
                                            Expr *Init);

MemInitResult ActOnMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  SourceLocation LParenLoc,
                                  ArrayRef<Expr *> Args,
                                  SourceLocation RParenLoc,
                                  SourceLocation EllipsisLoc);

MemInitResult ActOnMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  Expr *InitList,
                                  SourceLocation EllipsisLoc);

MemInitResult BuildMemInitializer(Decl *ConstructorD,
                                  Scope *S,
                                  CXXScopeSpec &SS,
                                  IdentifierInfo *MemberOrBase,
                                  ParsedType TemplateTypeTy,
                                  const DeclSpec &DS,
                                  SourceLocation IdLoc,
                                  Expr *Init,
                                  SourceLocation EllipsisLoc);

MemInitResult BuildMemberInitializer(ValueDecl *Member,
                                     Expr *Init,
                                     SourceLocation IdLoc);

MemInitResult BuildBaseInitializer(QualType BaseType,
                                   TypeSourceInfo *BaseTInfo,
                                   Expr *Init,
                                   CXXRecordDecl *ClassDecl,
                                   SourceLocation EllipsisLoc);

MemInitResult BuildDelegatingInitializer(TypeSourceInfo *TInfo,
                                         Expr *Init,
                                         CXXRecordDecl *ClassDecl);

bool SetDelegatingInitializer(CXXConstructorDecl *Constructor,
                              CXXCtorInitializer *Initializer);

bool SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
                         ArrayRef<CXXCtorInitializer *> Initializers = None);

void SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation);


/// MarkBaseAndMemberDestructorsReferenced - Given a record decl,
/// mark all the non-trivial destructors of its members and bases as
/// referenced.
void MarkBaseAndMemberDestructorsReferenced(SourceLocation Loc,
                                            CXXRecordDecl *Record);

/// Mark destructors of virtual bases of this class referenced. In the Itanium
/// C++ ABI, this is done when emitting a destructor for any non-abstract
/// class. In the Microsoft C++ ABI, this is done any time a class's
/// destructor is referenced.
void MarkVirtualBaseDestructorsReferenced(
    SourceLocation Location, CXXRecordDecl *ClassDecl,
    llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases = nullptr);

/// Do semantic checks to allow the complete destructor variant to be emitted
/// when the destructor is defined in another translation unit. In the Itanium
/// C++ ABI, destructor variants are emitted together. In the MS C++ ABI, they
/// can be emitted in separate TUs. To emit the complete variant, run a subset
/// of the checks performed when emitting a regular destructor.
void CheckCompleteDestructorVariant(SourceLocation CurrentLocation,
                                    CXXDestructorDecl *Dtor);

/// The list of classes whose vtables have been used within
/// this translation unit, and the source locations at which the
/// first use occurred.
typedef std::pair<CXXRecordDecl*, SourceLocation> VTableUse;

/// The list of vtables that are required but have not yet been
/// materialized.
SmallVector<VTableUse, 16> VTableUses;

/// The set of classes whose vtables have been used within
/// this translation unit, and a bit that will be true if the vtable is
/// required to be emitted (otherwise, it should be emitted only if needed
/// by code generation).
llvm::DenseMap<CXXRecordDecl *, bool> VTablesUsed;

/// Load any externally-stored vtable uses.
void LoadExternalVTableUses();

/// Note that the vtable for the given class was used at the
/// given location.
void MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
                    bool DefinitionRequired = false);

/// Mark the exception specifications of all virtual member functions
/// in the given class as needed.
void MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
                                           const CXXRecordDecl *RD);

/// MarkVirtualMembersReferenced - Will mark all members of the given
/// CXXRecordDecl referenced.
void MarkVirtualMembersReferenced(SourceLocation Loc, const CXXRecordDecl *RD,
                                  bool ConstexprOnly = false);

/// Define all of the vtables that have been used in this
/// translation unit and reference any virtual members used by those
/// vtables.
///
/// \returns true if any work was done, false otherwise.
bool DefineUsedVTables();

void AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl);

void ActOnMemInitializers(Decl *ConstructorDecl,
                          SourceLocation ColonLoc,
                          ArrayRef<CXXCtorInitializer*> MemInits,
                          bool AnyErrors);

/// Check class-level dllimport/dllexport attribute. The caller must
/// ensure that referenceDLLExportedClassMethods is called some point later
/// when all outer classes of Class are complete.
void checkClassLevelDLLAttribute(CXXRecordDecl *Class);
void checkClassLevelCodeSegAttribute(CXXRecordDecl *Class);

void referenceDLLExportedClassMethods();

void propagateDLLAttrToBaseClassTemplate(
    CXXRecordDecl *Class, Attr *ClassAttr,
    ClassTemplateSpecializationDecl *BaseTemplateSpec,
    SourceLocation BaseLoc);

/// Add gsl::Pointer attribute to std::container::iterator
/// \param ND The declaration that introduces the name
/// std::container::iterator. \param UnderlyingRecord The record named by ND.
void inferGslPointerAttribute(NamedDecl *ND, CXXRecordDecl *UnderlyingRecord);

/// Add [[gsl::Owner]] and [[gsl::Pointer]] attributes for std:: types.
void inferGslOwnerPointerAttribute(CXXRecordDecl *Record);

/// Add [[gsl::Pointer]] attributes for std:: types.
void inferGslPointerAttribute(TypedefNameDecl *TD);

void CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record);

/// Check that the C++ class annoated with "trivial_abi" satisfies all the
/// conditions that are needed for the attribute to have an effect.
void checkIllFormedTrivialABIStruct(CXXRecordDecl &RD);

void ActOnFinishCXXMemberSpecification(Scope *S, SourceLocation RLoc,
                                       Decl *TagDecl, SourceLocation LBrac,
                                       SourceLocation RBrac,
                                       const ParsedAttributesView &AttrList);
void ActOnFinishCXXMemberDecls();
void ActOnFinishCXXNonNestedClass();

void ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param);
unsigned ActOnReenterTemplateScope(Decl *Template,
                                   llvm::function_ref<Scope *()> EnterScope);
void ActOnStartDelayedMemberDeclarations(Scope *S, Decl *Record);
void ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
void ActOnDelayedCXXMethodParameter(Scope *S, Decl *Param);
void ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *Record);
void ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *Method);
void ActOnFinishDelayedMemberInitializers(Decl *Record);
void MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
                              CachedTokens &Toks);
void UnmarkAsLateParsedTemplate(FunctionDecl *FD);
bool IsInsideALocalClassWithinATemplateFunction();

Decl *ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                   Expr *AssertExpr,
                                   Expr *AssertMessageExpr,
                                   SourceLocation RParenLoc);
Decl *BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                   Expr *AssertExpr,
                                   StringLiteral *AssertMessageExpr,
                                   SourceLocation RParenLoc,
                                   bool Failed);

FriendDecl *CheckFriendTypeDecl(SourceLocation LocStart,
                                SourceLocation FriendLoc,
                                TypeSourceInfo *TSInfo);
Decl *ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
                          MultiTemplateParamsArg TemplateParams);
NamedDecl *ActOnFriendFunctionDecl(Scope *S, Declarator &D,
                                   MultiTemplateParamsArg TemplateParams);

QualType CheckConstructorDeclarator(Declarator &D, QualType R,
                                    StorageClass& SC);
void CheckConstructor(CXXConstructorDecl *Constructor);
QualType CheckDestructorDeclarator(Declarator &D, QualType R,
                                   StorageClass& SC);
bool CheckDestructor(CXXDestructorDecl *Destructor);
void CheckConversionDeclarator(Declarator &D, QualType &R,
                               StorageClass& SC);
Decl *ActOnConversionDeclarator(CXXConversionDecl *Conversion);
void CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
                                   StorageClass &SC);
void CheckDeductionGuideTemplate(FunctionTemplateDecl *TD);

void CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *MD);

bool CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
                                           CXXSpecialMember CSM);
void CheckDelayedMemberExceptionSpecs();

bool CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *MD,
                                        DefaultedComparisonKind DCK);
void DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
                                       FunctionDecl *Spaceship);
void DefineDefaultedComparison(SourceLocation Loc, FunctionDecl *FD,
                               DefaultedComparisonKind DCK);

//===--------------------------------------------------------------------===//
// C++ Derived Classes
//

/// ActOnBaseSpecifier - Parsed a base specifier
CXXBaseSpecifier *CheckBaseSpecifier(CXXRecordDecl *Class,
                                     SourceRange SpecifierRange,
                                     bool Virtual, AccessSpecifier Access,
                                     TypeSourceInfo *TInfo,
                                     SourceLocation EllipsisLoc);

BaseResult ActOnBaseSpecifier(Decl *classdecl,
                              SourceRange SpecifierRange,
                              ParsedAttributes &Attrs,
                              bool Virtual, AccessSpecifier Access,
                              ParsedType basetype,
                              SourceLocation BaseLoc,
                              SourceLocation EllipsisLoc);

bool AttachBaseSpecifiers(CXXRecordDecl *Class,
                          MutableArrayRef<CXXBaseSpecifier *> Bases);
void ActOnBaseSpecifiers(Decl *ClassDecl,
                         MutableArrayRef<CXXBaseSpecifier *> Bases);

bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base);
bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
                   CXXBasePaths &Paths);

// FIXME: I don't like this name.
void BuildBasePathArray(const CXXBasePaths &Paths, CXXCastPath &BasePath);

bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                  SourceLocation Loc, SourceRange Range,
                                  CXXCastPath *BasePath = nullptr,
                                  bool IgnoreAccess = false);
bool CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                  unsigned InaccessibleBaseID,
                                  unsigned AmbiguousBaseConvID,
                                  SourceLocation Loc, SourceRange Range,
                                  DeclarationName Name,
                                  CXXCastPath *BasePath,
                                  bool IgnoreAccess = false);

std::string getAmbiguousPathsDisplayString(CXXBasePaths &Paths);

bool CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
                                       const CXXMethodDecl *Old);

/// CheckOverridingFunctionReturnType - Checks whether the return types are
/// covariant, according to C++ [class.virtual]p5.
bool CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
                                       const CXXMethodDecl *Old);

/// CheckOverridingFunctionExceptionSpec - Checks whether the exception
/// spec is a subset of base spec.
bool CheckOverridingFunctionExceptionSpec(const CXXMethodDecl *New,
                                          const CXXMethodDecl *Old);

bool CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange);

/// CheckOverrideControl - Check C++11 override control semantics.
void CheckOverrideControl(NamedDecl *D);

/// DiagnoseAbsenceOfOverrideControl - Diagnose if 'override' keyword was
/// not used in the declaration of an overriding method.
void DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent);

/// CheckForFunctionMarkedFinal - Checks whether a virtual member function
/// overrides a virtual member function marked 'final', according to
/// C++11 [class.virtual]p4.
bool CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
                                            const CXXMethodDecl *Old);


//===--------------------------------------------------------------------===//
// C++ Access Control
//

enum AccessResult {
  AR_accessible,
  AR_inaccessible,
  AR_dependent,
  AR_delayed
};

bool SetMemberAccessSpecifier(NamedDecl *MemberDecl,
                              NamedDecl *PrevMemberDecl,
                              AccessSpecifier LexicalAS);

AccessResult CheckUnresolvedMemberAccess(UnresolvedMemberExpr *E,
                                         DeclAccessPair FoundDecl);
AccessResult CheckUnresolvedLookupAccess(UnresolvedLookupExpr *E,
                                         DeclAccessPair FoundDecl);
AccessResult CheckAllocationAccess(SourceLocation OperatorLoc,
                                   SourceRange PlacementRange,
                                   CXXRecordDecl *NamingClass,
                                   DeclAccessPair FoundDecl,
                                   bool Diagnose = true);
AccessResult CheckConstructorAccess(SourceLocation Loc,
                                    CXXConstructorDecl *D,
                                    DeclAccessPair FoundDecl,
                                    const InitializedEntity &Entity,
                                    bool IsCopyBindingRefToTemp = false);
AccessResult CheckConstructorAccess(SourceLocation Loc,
                                    CXXConstructorDecl *D,
                                    DeclAccessPair FoundDecl,
                                    const InitializedEntity &Entity,
                                    const PartialDiagnostic &PDiag);
AccessResult CheckDestructorAccess(SourceLocation Loc,
                                   CXXDestructorDecl *Dtor,
                                   const PartialDiagnostic &PDiag,
                                   QualType objectType = QualType());
AccessResult CheckFriendAccess(NamedDecl *D);
AccessResult CheckMemberAccess(SourceLocation UseLoc,
                               CXXRecordDecl *NamingClass,
                               DeclAccessPair Found);
AccessResult
CheckStructuredBindingMemberAccess(SourceLocation UseLoc,
                                   CXXRecordDecl *DecomposedClass,
                                   DeclAccessPair Field);
AccessResult CheckMemberOperatorAccess(SourceLocation Loc,
                                       Expr *ObjectExpr,
                                       Expr *ArgExpr,
                                       DeclAccessPair FoundDecl);
AccessResult CheckAddressOfMemberAccess(Expr *OvlExpr,
                                        DeclAccessPair FoundDecl);
AccessResult CheckBaseClassAccess(SourceLocation AccessLoc,
                                  QualType Base, QualType Derived,
                                  const CXXBasePath &Path,
                                  unsigned DiagID,
                                  bool ForceCheck = false,
                                  bool ForceUnprivileged = false);
void CheckLookupAccess(const LookupResult &R);
bool IsSimplyAccessible(NamedDecl *Decl, CXXRecordDecl *NamingClass,
                        QualType BaseType);
bool isMemberAccessibleForDeletion(CXXRecordDecl *NamingClass,
                                   DeclAccessPair Found, QualType ObjectType,
                                   SourceLocation Loc,
                                   const PartialDiagnostic &Diag);
bool isMemberAccessibleForDeletion(CXXRecordDecl *NamingClass,
                                   DeclAccessPair Found,
                                   QualType ObjectType) {
  return isMemberAccessibleForDeletion(NamingClass, Found, ObjectType,
                                       SourceLocation(), PDiag());
}

void HandleDependentAccessCheck(const DependentDiagnostic &DD,
                       const MultiLevelTemplateArgumentList &TemplateArgs);
void PerformDependentDiagnostics(const DeclContext *Pattern,
                      const MultiLevelTemplateArgumentList &TemplateArgs);

void HandleDelayedAccessCheck(sema::DelayedDiagnostic &DD, Decl *Ctx);

/// When true, access checking violations are treated as SFINAE
/// failures rather than hard errors.
bool AccessCheckingSFINAE;

enum AbstractDiagSelID {
  AbstractNone = -1,
  AbstractReturnType,
  AbstractParamType,
  AbstractVariableType,
  AbstractFieldType,
  AbstractIvarType,
  AbstractSynthesizedIvarType,
  AbstractArrayType
};

bool isAbstractType(SourceLocation Loc, QualType T);
bool RequireNonAbstractType(SourceLocation Loc, QualType T,
                            TypeDiagnoser &Diagnoser);
template <typename... Ts>
bool RequireNonAbstractType(SourceLocation Loc, QualType T, unsigned DiagID,
                            const Ts &...Args) {
  BoundTypeDiagnoser<Ts...> Diagnoser(DiagID, Args...);
  return RequireNonAbstractType(Loc, T, Diagnoser);
}

void DiagnoseAbstractType(const CXXRecordDecl *RD);

//===--------------------------------------------------------------------===//
// C++ Overloaded Operators [C++ 13.5]
//

bool CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl);

bool CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl);

//===--------------------------------------------------------------------===//
// C++ Templates [C++ 14]
//
void FilterAcceptableTemplateNames(LookupResult &R,
                                   bool AllowFunctionTemplates = true,
                                   bool AllowDependent = true);
bool hasAnyAcceptableTemplateNames(LookupResult &R,
                                   bool AllowFunctionTemplates = true,
                                   bool AllowDependent = true,
                                   bool AllowNonTemplateFunctions = false);
/// Try to interpret the lookup result D as a template-name.
///
/// \param D A declaration found by name lookup.
/// \param AllowFunctionTemplates Whether function templates should be
///        considered valid results.
/// \param AllowDependent Whether unresolved using declarations (that might
///        name templates) should be considered valid results.
static NamedDecl *getAsTemplateNameDecl(NamedDecl *D,
                                        bool AllowFunctionTemplates = true,
                                        bool AllowDependent = true);

enum TemplateNameIsRequiredTag { TemplateNameIsRequired };
/// Whether and why a template name is required in this lookup.
class RequiredTemplateKind {
public:
  /// Template name is required if TemplateKWLoc is valid.
  RequiredTemplateKind(SourceLocation TemplateKWLoc = SourceLocation())
      : TemplateKW(TemplateKWLoc) {}
  /// Template name is unconditionally required.
  RequiredTemplateKind(TemplateNameIsRequiredTag) : TemplateKW() {}

  SourceLocation getTemplateKeywordLoc() const {
    return TemplateKW.getValueOr(SourceLocation());
  }
  bool hasTemplateKeyword() const { return getTemplateKeywordLoc().isValid(); }
  bool isRequired() const { return TemplateKW != SourceLocation(); }
  explicit operator bool() const { return isRequired(); }

private:
  llvm::Optional<SourceLocation> TemplateKW;
};

enum class AssumedTemplateKind {
  /// This is not assumed to be a template name.
  None,
  /// This is assumed to be a template name because lookup found nothing.
  FoundNothing,
  /// This is assumed to be a template name because lookup found one or more
  /// functions (but no function templates).
  FoundFunctions,
};
bool LookupTemplateName(
    LookupResult &R, Scope *S, CXXScopeSpec &SS, QualType ObjectType,
    bool EnteringContext, bool &MemberOfUnknownSpecialization,
    RequiredTemplateKind RequiredTemplate = SourceLocation(),
    AssumedTemplateKind *ATK = nullptr, bool AllowTypoCorrection = true);

TemplateNameKind isTemplateName(Scope *S,
                                CXXScopeSpec &SS,
                                bool hasTemplateKeyword,
                                const UnqualifiedId &Name,
                                ParsedType ObjectType,
                                bool EnteringContext,
                                TemplateTy &Template,
                                bool &MemberOfUnknownSpecialization,
                                bool Disambiguation = false);

/// Try to resolve an undeclared template name as a type template.
///
/// Sets II to the identifier corresponding to the template name, and updates
/// Name to a corresponding (typo-corrected) type template name and TNK to
/// the corresponding kind, if possible.
void ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &Name,
                                     TemplateNameKind &TNK,
                                     SourceLocation NameLoc,
                                     IdentifierInfo *&II);

bool resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
                                      SourceLocation NameLoc,
                                      bool Diagnose = true);

/// Determine whether a particular identifier might be the name in a C++1z
/// deduction-guide declaration.
bool isDeductionGuideName(Scope *S, const IdentifierInfo &Name,
                          SourceLocation NameLoc,
                          ParsedTemplateTy *Template = nullptr);

bool DiagnoseUnknownTemplateName(const IdentifierInfo &II,
                                 SourceLocation IILoc,
                                 Scope *S,
                                 const CXXScopeSpec *SS,
                                 TemplateTy &SuggestedTemplate,
                                 TemplateNameKind &SuggestedKind);

bool DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
                                    NamedDecl *Instantiation,
                                    bool InstantiatedFromMember,
                                    const NamedDecl *Pattern,
                                    const NamedDecl *PatternDef,
                                    TemplateSpecializationKind TSK,
                                    bool Complain = true);

void DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl);
TemplateDecl *AdjustDeclIfTemplate(Decl *&Decl);

NamedDecl *ActOnTypeParameter(Scope *S, bool Typename,
                              SourceLocation EllipsisLoc,
                              SourceLocation KeyLoc,
                              IdentifierInfo *ParamName,
                              SourceLocation ParamNameLoc,
                              unsigned Depth, unsigned Position,
                              SourceLocation EqualLoc,
                              ParsedType DefaultArg, bool HasTypeConstraint);

bool ActOnTypeConstraint(const CXXScopeSpec &SS,
                         TemplateIdAnnotation *TypeConstraint,
                         TemplateTypeParmDecl *ConstrainedParameter,
                         SourceLocation EllipsisLoc);
bool BuildTypeConstraint(const CXXScopeSpec &SS,
                         TemplateIdAnnotation *TypeConstraint,
                         TemplateTypeParmDecl *ConstrainedParameter,
                         SourceLocation EllipsisLoc,
                         bool AllowUnexpandedPack);

bool AttachTypeConstraint(NestedNameSpecifierLoc NS,
                          DeclarationNameInfo NameInfo,
                          ConceptDecl *NamedConcept,
                          const TemplateArgumentListInfo *TemplateArgs,
                          TemplateTypeParmDecl *ConstrainedParameter,
                          SourceLocation EllipsisLoc);

bool AttachTypeConstraint(AutoTypeLoc TL,
                          NonTypeTemplateParmDecl *ConstrainedParameter,
                          SourceLocation EllipsisLoc);

bool RequireStructuralType(QualType T, SourceLocation Loc);

QualType CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
                                           SourceLocation Loc);
QualType CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc);

NamedDecl *ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
                                    unsigned Depth,
                                    unsigned Position,
                                    SourceLocation EqualLoc,
                                    Expr *DefaultArg);
NamedDecl *ActOnTemplateTemplateParameter(Scope *S,
                                     SourceLocation TmpLoc,
                                     TemplateParameterList *Params,
                                     SourceLocation EllipsisLoc,
                                     IdentifierInfo *ParamName,
                                     SourceLocation ParamNameLoc,
                                     unsigned Depth,
                                     unsigned Position,
                                     SourceLocation EqualLoc,
                                     ParsedTemplateArgument DefaultArg);

TemplateParameterList *
ActOnTemplateParameterList(unsigned Depth,
                           SourceLocation ExportLoc,
                           SourceLocation TemplateLoc,
                           SourceLocation LAngleLoc,
                           ArrayRef<NamedDecl *> Params,
                           SourceLocation RAngleLoc,
                           Expr *RequiresClause);

/// The context in which we are checking a template parameter list.
enum TemplateParamListContext {
  TPC_ClassTemplate,
  TPC_VarTemplate,
  TPC_FunctionTemplate,
  TPC_ClassTemplateMember,
  TPC_FriendClassTemplate,
  TPC_FriendFunctionTemplate,
  TPC_FriendFunctionTemplateDefinition,
  TPC_TypeAliasTemplate
};

bool CheckTemplateParameterList(TemplateParameterList *NewParams,
                                TemplateParameterList *OldParams,
                                TemplateParamListContext TPC,
                                SkipBodyInfo *SkipBody = nullptr);
TemplateParameterList *MatchTemplateParametersToScopeSpecifier(
    SourceLocation DeclStartLoc, SourceLocation DeclLoc,
    const CXXScopeSpec &SS, TemplateIdAnnotation *TemplateId,
    ArrayRef<TemplateParameterList *> ParamLists,
    bool IsFriend, bool &IsMemberSpecialization, bool &Invalid,
    bool SuppressDiagnostic = false);

DeclResult CheckClassTemplate(
    Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
    CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
    const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
    AccessSpecifier AS, SourceLocation ModulePrivateLoc,
    SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
    TemplateParameterList **OuterTemplateParamLists,
    SkipBodyInfo *SkipBody = nullptr);

TemplateArgumentLoc getTrivialTemplateArgumentLoc(const TemplateArgument &Arg,
                                                  QualType NTTPType,
                                                  SourceLocation Loc);

/// Get a template argument mapping the given template parameter to itself,
/// e.g. for X in \c template<int X>, this would return an expression template
/// argument referencing X.
TemplateArgumentLoc getIdentityTemplateArgumentLoc(NamedDecl *Param,
                                                   SourceLocation Location);

void translateTemplateArguments(const ASTTemplateArgsPtr &In,
                                TemplateArgumentListInfo &Out);

ParsedTemplateArgument ActOnTemplateTypeArgument(TypeResult ParsedType);

void NoteAllFoundTemplates(TemplateName Name);

QualType CheckTemplateIdType(TemplateName Template,
                             SourceLocation TemplateLoc,
                            TemplateArgumentListInfo &TemplateArgs);

TypeResult
ActOnTemplateIdType(Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
                    TemplateTy Template, IdentifierInfo *TemplateII,
                    SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
                    ASTTemplateArgsPtr TemplateArgs, SourceLocation RAngleLoc,
                    bool IsCtorOrDtorName = false, bool IsClassName = false);

/// Parsed an elaborated-type-specifier that refers to a template-id,
/// such as \c class T::template apply<U>.
TypeResult ActOnTagTemplateIdType(TagUseKind TUK,
                                  TypeSpecifierType TagSpec,
                                  SourceLocation TagLoc,
                                  CXXScopeSpec &SS,
                                  SourceLocation TemplateKWLoc,
                                  TemplateTy TemplateD,
                                  SourceLocation TemplateLoc,
                                  SourceLocation LAngleLoc,
                                  ASTTemplateArgsPtr TemplateArgsIn,
                                  SourceLocation RAngleLoc);

DeclResult ActOnVarTemplateSpecialization(
    Scope *S, Declarator &D, TypeSourceInfo *DI,
    SourceLocation TemplateKWLoc, TemplateParameterList *TemplateParams,
    StorageClass SC, bool IsPartialSpecialization);

/// Get the specialization of the given variable template corresponding to
/// the specified argument list, or a null-but-valid result if the arguments
/// are dependent.
DeclResult CheckVarTemplateId(VarTemplateDecl *Template,
                              SourceLocation TemplateLoc,
                              SourceLocation TemplateNameLoc,
                              const TemplateArgumentListInfo &TemplateArgs);

/// Form a reference to the specialization of the given variable template
/// corresponding to the specified argument list, or a null-but-valid result
/// if the arguments are dependent.
ExprResult CheckVarTemplateId(const CXXScopeSpec &SS,
                              const DeclarationNameInfo &NameInfo,
                              VarTemplateDecl *Template,
                              SourceLocation TemplateLoc,
                              const TemplateArgumentListInfo *TemplateArgs);

ExprResult
CheckConceptTemplateId(const CXXScopeSpec &SS,
                       SourceLocation TemplateKWLoc,
                       const DeclarationNameInfo &ConceptNameInfo,
                       NamedDecl *FoundDecl, ConceptDecl *NamedConcept,
                       const TemplateArgumentListInfo *TemplateArgs);

void diagnoseMissingTemplateArguments(TemplateName Name, SourceLocation Loc);

ExprResult BuildTemplateIdExpr(const CXXScopeSpec &SS,
                               SourceLocation TemplateKWLoc,
                               LookupResult &R,
                               bool RequiresADL,
                             const TemplateArgumentListInfo *TemplateArgs);

ExprResult BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
                                        SourceLocation TemplateKWLoc,
                             const DeclarationNameInfo &NameInfo,
                             const TemplateArgumentListInfo *TemplateArgs);

TemplateNameKind ActOnTemplateName(
    Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
    const UnqualifiedId &Name, ParsedType ObjectType, bool EnteringContext,
    TemplateTy &Template, bool AllowInjectedClassName = false);

DeclResult ActOnClassTemplateSpecialization(
    Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
    SourceLocation ModulePrivateLoc, CXXScopeSpec &SS,
    TemplateIdAnnotation &TemplateId, const ParsedAttributesView &Attr,
    MultiTemplateParamsArg TemplateParameterLists,
    SkipBodyInfo *SkipBody = nullptr);

bool CheckTemplatePartialSpecializationArgs(SourceLocation Loc,
                                            TemplateDecl *PrimaryTemplate,
                                            unsigned NumExplicitArgs,
                                            ArrayRef<TemplateArgument> Args);
void CheckTemplatePartialSpecialization(
    ClassTemplatePartialSpecializationDecl *Partial);
void CheckTemplatePartialSpecialization(
    VarTemplatePartialSpecializationDecl *Partial);

Decl *ActOnTemplateDeclarator(Scope *S,
                              MultiTemplateParamsArg TemplateParameterLists,
                              Declarator &D);

bool
CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
                                       TemplateSpecializationKind NewTSK,
                                       NamedDecl *PrevDecl,
                                       TemplateSpecializationKind PrevTSK,
                                       SourceLocation PrevPtOfInstantiation,
                                       bool &SuppressNew);

bool CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
                  const TemplateArgumentListInfo &ExplicitTemplateArgs,
                                                  LookupResult &Previous);

bool CheckFunctionTemplateSpecialization(
    FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
    LookupResult &Previous, bool QualifiedFriend = false);
bool CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous);
void CompleteMemberSpecialization(NamedDecl *Member, LookupResult &Previous);

DeclResult ActOnExplicitInstantiation(
    Scope *S, SourceLocation ExternLoc, SourceLocation TemplateLoc,
    unsigned TagSpec, SourceLocation KWLoc, const CXXScopeSpec &SS,
    TemplateTy Template, SourceLocation TemplateNameLoc,
    SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgs,
    SourceLocation RAngleLoc, const ParsedAttributesView &Attr);

DeclResult ActOnExplicitInstantiation(Scope *S, SourceLocation ExternLoc,
                                      SourceLocation TemplateLoc,
                                      unsigned TagSpec, SourceLocation KWLoc,
                                      CXXScopeSpec &SS, IdentifierInfo *Name,
                                      SourceLocation NameLoc,
                                      const ParsedAttributesView &Attr);

DeclResult ActOnExplicitInstantiation(Scope *S,
                                      SourceLocation ExternLoc,
                                      SourceLocation TemplateLoc,
                                      Declarator &D);

TemplateArgumentLoc
SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
                                        SourceLocation TemplateLoc,
                                        SourceLocation RAngleLoc,
                                        Decl *Param,
                                        SmallVectorImpl<TemplateArgument>
                                          &Converted,
                                        bool &HasDefaultArg);

/// Specifies the context in which a particular template
/// argument is being checked.
enum CheckTemplateArgumentKind {
  /// The template argument was specified in the code or was
  /// instantiated with some deduced template arguments.
  CTAK_Specified,

  /// The template argument was deduced via template argument
  /// deduction.
  CTAK_Deduced,

  /// The template argument was deduced from an array bound
  /// via template argument deduction.
  CTAK_DeducedFromArrayBound
};

bool CheckTemplateArgument(NamedDecl *Param,
                           TemplateArgumentLoc &Arg,
                           NamedDecl *Template,
                           SourceLocation TemplateLoc,
                           SourceLocation RAngleLoc,
                           unsigned ArgumentPackIndex,
                         SmallVectorImpl<TemplateArgument> &Converted,
                           CheckTemplateArgumentKind CTAK = CTAK_Specified);

/// Check that the given template arguments can be be provided to
/// the given template, converting the arguments along the way.
///
/// \param Template The template to which the template arguments are being
/// provided.
///
/// \param TemplateLoc The location of the template name in the source.
///
/// \param TemplateArgs The list of template arguments. If the template is
/// a template template parameter, this function may extend the set of
/// template arguments to also include substituted, defaulted template
/// arguments.
///
/// \param PartialTemplateArgs True if the list of template arguments is
/// intentionally partial, e.g., because we're checking just the initial
/// set of template arguments.
///
/// \param Converted Will receive the converted, canonicalized template
/// arguments.
///
/// \param UpdateArgsWithConversions If \c true, update \p TemplateArgs to
/// contain the converted forms of the template arguments as written.
/// Otherwise, \p TemplateArgs will not be modified.
///
/// \param ConstraintsNotSatisfied If provided, and an error occured, will
/// receive true if the cause for the error is the associated constraints of
/// the template not being satisfied by the template arguments.
///
/// \returns true if an error occurred, false otherwise.
bool CheckTemplateArgumentList(TemplateDecl *Template,
                               SourceLocation TemplateLoc,
                               TemplateArgumentListInfo &TemplateArgs,
                               bool PartialTemplateArgs,
                               SmallVectorImpl<TemplateArgument> &Converted,
                               bool UpdateArgsWithConversions = true,
                               bool *ConstraintsNotSatisfied = nullptr);

bool CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
                               TemplateArgumentLoc &Arg,
                         SmallVectorImpl<TemplateArgument> &Converted);

bool CheckTemplateArgument(TypeSourceInfo *Arg);
ExprResult CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
                                 QualType InstantiatedParamType, Expr *Arg,
                                 TemplateArgument &Converted,
                             CheckTemplateArgumentKind CTAK = CTAK_Specified);
bool CheckTemplateTemplateArgument(TemplateTemplateParmDecl *Param,
                                   TemplateParameterList *Params,
                                   TemplateArgumentLoc &Arg);

ExprResult
BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
                                        QualType ParamType,
                                        SourceLocation Loc);
ExprResult
BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
                                            SourceLocation Loc);

/// Enumeration describing how template parameter lists are compared
/// for equality.
enum TemplateParameterListEqualKind {
  /// We are matching the template parameter lists of two templates
  /// that might be redeclarations.
  ///
  /// \code
  /// template<typename T> struct X;
  /// template<typename T> struct X;
  /// \endcode
  TPL_TemplateMatch,

  /// We are matching the template parameter lists of two template
  /// template parameters as part of matching the template parameter lists
  /// of two templates that might be redeclarations.
  ///
  /// \code
  /// template<template<int I> class TT> struct X;
  /// template<template<int Value> class Other> struct X;
  /// \endcode
  TPL_TemplateTemplateParmMatch,

  /// We are matching the template parameter lists of a template
  /// template argument against the template parameter lists of a template
  /// template parameter.
  ///
  /// \code
  /// template<template<int Value> class Metafun> struct X;
  /// template<int Value> struct integer_c;
  /// X<integer_c> xic;
  /// \endcode
  TPL_TemplateTemplateArgumentMatch
};

bool TemplateParameterListsAreEqual(TemplateParameterList *New,
                                    TemplateParameterList *Old,
                                    bool Complain,
                                    TemplateParameterListEqualKind Kind,
                                    SourceLocation TemplateArgLoc
                                      = SourceLocation());

bool CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams);

/// Called when the parser has parsed a C++ typename
/// specifier, e.g., "typename T::type".
///
/// \param S The scope in which this typename type occurs.
/// \param TypenameLoc the location of the 'typename' keyword
/// \param SS the nested-name-specifier following the typename (e.g., 'T::').
/// \param II the identifier we're retrieving (e.g., 'type' in the example).
/// \param IdLoc the location of the identifier.
TypeResult
ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
                  const CXXScopeSpec &SS, const IdentifierInfo &II,
                  SourceLocation IdLoc);

/// Called when the parser has parsed a C++ typename
/// specifier that ends in a template-id, e.g.,
/// "typename MetaFun::template apply<T1, T2>".
///
/// \param S The scope in which this typename type occurs.
/// \param TypenameLoc the location of the 'typename' keyword
/// \param SS the nested-name-specifier following the typename (e.g., 'T::').
/// \param TemplateLoc the location of the 'template' keyword, if any.
/// \param TemplateName The template name.
/// \param TemplateII The identifier used to name the template.
/// \param TemplateIILoc The location of the template name.
/// \param LAngleLoc The location of the opening angle bracket  ('<').
/// \param TemplateArgs The template arguments.
/// \param RAngleLoc The location of the closing angle bracket  ('>').
TypeResult
ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
                  const CXXScopeSpec &SS,
                  SourceLocation TemplateLoc,
                  TemplateTy TemplateName,
                  IdentifierInfo *TemplateII,
                  SourceLocation TemplateIILoc,
                  SourceLocation LAngleLoc,
                  ASTTemplateArgsPtr TemplateArgs,
                  SourceLocation RAngleLoc);

QualType CheckTypenameType(ElaboratedTypeKeyword Keyword,
                           SourceLocation KeywordLoc,
                           NestedNameSpecifierLoc QualifierLoc,
                           const IdentifierInfo &II,
                           SourceLocation IILoc,
                           TypeSourceInfo **TSI,
                           bool DeducedTSTContext);

QualType CheckTypenameType(ElaboratedTypeKeyword Keyword,
                           SourceLocation KeywordLoc,
                           NestedNameSpecifierLoc QualifierLoc,
                           const IdentifierInfo &II,
                           SourceLocation IILoc,
                           bool DeducedTSTContext = true);


TypeSourceInfo *RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
                                                  SourceLocation Loc,
                                                  DeclarationName Name);
bool RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS);

ExprResult RebuildExprInCurrentInstantiation(Expr *E);
bool RebuildTemplateParamsInCurrentInstantiation(
                                              TemplateParameterList *Params);

std::string
getTemplateArgumentBindingsText(const TemplateParameterList *Params,
                                const TemplateArgumentList &Args);

std::string
getTemplateArgumentBindingsText(const TemplateParameterList *Params,
                                const TemplateArgument *Args,
                                unsigned NumArgs);

//===--------------------------------------------------------------------===//
// C++ Concepts
//===--------------------------------------------------------------------===//
Decl *ActOnConceptDefinition(
    Scope *S, MultiTemplateParamsArg TemplateParameterLists,
    IdentifierInfo *Name, SourceLocation NameLoc, Expr *ConstraintExpr);

RequiresExprBodyDecl *
ActOnStartRequiresExpr(SourceLocation RequiresKWLoc,
                       ArrayRef<ParmVarDecl *> LocalParameters,
                       Scope *BodyScope);
void ActOnFinishRequiresExpr();
concepts::Requirement *ActOnSimpleRequirement(Expr *E);
concepts::Requirement *ActOnTypeRequirement(
    SourceLocation TypenameKWLoc, CXXScopeSpec &SS, SourceLocation NameLoc,
    IdentifierInfo *TypeName, TemplateIdAnnotation *TemplateId);
concepts::Requirement *ActOnCompoundRequirement(Expr *E,
                                                SourceLocation NoexceptLoc);
concepts::Requirement *
ActOnCompoundRequirement(
    Expr *E, SourceLocation NoexceptLoc, CXXScopeSpec &SS,
    TemplateIdAnnotation *TypeConstraint, unsigned Depth);
concepts::Requirement *ActOnNestedRequirement(Expr *Constraint);
concepts::ExprRequirement *
BuildExprRequirement(
    Expr *E, bool IsSatisfied, SourceLocation NoexceptLoc,
    concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement);
concepts::ExprRequirement *
BuildExprRequirement(
    concepts::Requirement::SubstitutionDiagnostic *ExprSubstDiag,
    bool IsSatisfied, SourceLocation NoexceptLoc,
    concepts::ExprRequirement::ReturnTypeRequirement ReturnTypeRequirement);
concepts::TypeRequirement *BuildTypeRequirement(TypeSourceInfo *Type);
concepts::TypeRequirement *
BuildTypeRequirement(
    concepts::Requirement::SubstitutionDiagnostic *SubstDiag);
concepts::NestedRequirement *BuildNestedRequirement(Expr *E);
concepts::NestedRequirement *
BuildNestedRequirement(
    concepts::Requirement::SubstitutionDiagnostic *SubstDiag);
ExprResult ActOnRequiresExpr(SourceLocation RequiresKWLoc,
                             RequiresExprBodyDecl *Body,
                             ArrayRef<ParmVarDecl *> LocalParameters,
                             ArrayRef<concepts::Requirement *> Requirements,
                             SourceLocation ClosingBraceLoc);

//===--------------------------------------------------------------------===//
// C++ Variadic Templates (C++0x [temp.variadic])
//===--------------------------------------------------------------------===//

/// Determine whether an unexpanded parameter pack might be permitted in this
/// location. Useful for error recovery.
bool isUnexpandedParameterPackPermitted();

/// The context in which an unexpanded parameter pack is
/// being diagnosed.
///
/// Note that the values of this enumeration line up with the first
/// argument to the \c err_unexpanded_parameter_pack diagnostic.
enum UnexpandedParameterPackContext {
  /// An arbitrary expression.
  UPPC_Expression = 0,

  /// The base type of a class type.
  UPPC_BaseType,

  /// The type of an arbitrary declaration.
  UPPC_DeclarationType,

  /// The type of a data member.
  UPPC_DataMemberType,

  /// The size of a bit-field.
  UPPC_BitFieldWidth,

  /// The expression in a static assertion.
  UPPC_StaticAssertExpression,

  /// The fixed underlying type of an enumeration.
  UPPC_FixedUnderlyingType,

  /// The enumerator value.
  UPPC_EnumeratorValue,

  /// A using declaration.
  UPPC_UsingDeclaration,

  /// A friend declaration.
  UPPC_FriendDeclaration,

  /// A declaration qualifier.
  UPPC_DeclarationQualifier,

  /// An initializer.
  UPPC_Initializer,

  /// A default argument.
  UPPC_DefaultArgument,

  /// The type of a non-type template parameter.
  UPPC_NonTypeTemplateParameterType,

  /// The type of an exception.
  UPPC_ExceptionType,

  /// Partial specialization.
  UPPC_PartialSpecialization,

  /// Microsoft __if_exists.
  UPPC_IfExists,

  /// Microsoft __if_not_exists.
  UPPC_IfNotExists,

  /// Lambda expression.
  UPPC_Lambda,

  /// Block expression.
  UPPC_Block,

  /// A type constraint.
  UPPC_TypeConstraint,

  // A requirement in a requires-expression.
  UPPC_Requirement,

  // A requires-clause.
  UPPC_RequiresClause,
};

/// Diagnose unexpanded parameter packs.
///
/// \param Loc The location at which we should emit the diagnostic.
///
/// \param UPPC The context in which we are diagnosing unexpanded
/// parameter packs.
///
/// \param Unexpanded the set of unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPacks(SourceLocation Loc,
                                      UnexpandedParameterPackContext UPPC,
                                ArrayRef<UnexpandedParameterPack> Unexpanded);

/// If the given type contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param Loc The source location where a diagnostc should be emitted.
///
/// \param T The type that is being checked for unexpanded parameter
/// packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(SourceLocation Loc, TypeSourceInfo *T,
                                     UnexpandedParameterPackContext UPPC);

/// If the given expression contains an unexpanded parameter
/// pack, diagnose the error.
///
/// \param E The expression that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(Expr *E,
                     UnexpandedParameterPackContext UPPC = UPPC_Expression);

/// If the given requirees-expression contains an unexpanded reference to one
/// of its own parameter packs, diagnose the error.
///
/// \param RE The requiress-expression that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPackInRequiresExpr(RequiresExpr *RE);

/// If the given nested-name-specifier contains an unexpanded
/// parameter pack, diagnose the error.
///
/// \param SS The nested-name-specifier that is being checked for
/// unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(const CXXScopeSpec &SS,
                                     UnexpandedParameterPackContext UPPC);

/// If the given name contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param NameInfo The name (with source location information) that
/// is being checked for unexpanded parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(const DeclarationNameInfo &NameInfo,
                                     UnexpandedParameterPackContext UPPC);

/// If the given template name contains an unexpanded parameter pack,
/// diagnose the error.
///
/// \param Loc The location of the template name.
///
/// \param Template The template name that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(SourceLocation Loc,
                                     TemplateName Template,
                                     UnexpandedParameterPackContext UPPC);

/// If the given template argument contains an unexpanded parameter
/// pack, diagnose the error.
///
/// \param Arg The template argument that is being checked for unexpanded
/// parameter packs.
///
/// \returns true if an error occurred, false otherwise.
bool DiagnoseUnexpandedParameterPack(TemplateArgumentLoc Arg,
                                     UnexpandedParameterPackContext UPPC);

/// Collect the set of unexpanded parameter packs within the given
/// template argument.
///
/// \param Arg The template argument that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TemplateArgument Arg,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// template argument.
///
/// \param Arg The template argument that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TemplateArgumentLoc Arg,
                  SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// type.
///
/// \param T The type that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(QualType T,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// type.
///
/// \param TL The type that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(TypeLoc TL,
                 SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// nested-name-specifier.
///
/// \param NNS The nested-name-specifier that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(NestedNameSpecifierLoc NNS,
                       SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Collect the set of unexpanded parameter packs within the given
/// name.
///
/// \param NameInfo The name that will be traversed to find
/// unexpanded parameter packs.
void collectUnexpandedParameterPacks(const DeclarationNameInfo &NameInfo,
                       SmallVectorImpl<UnexpandedParameterPack> &Unexpanded);

/// Invoked when parsing a template argument followed by an
/// ellipsis, which creates a pack expansion.
///
/// \param Arg The template argument preceding the ellipsis, which
/// may already be invalid.
///
/// \param EllipsisLoc The location of the ellipsis.
ParsedTemplateArgument ActOnPackExpansion(const ParsedTemplateArgument &Arg,
                                          SourceLocation EllipsisLoc);

/// Invoked when parsing a type followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Type The type preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
TypeResult ActOnPackExpansion(ParsedType Type, SourceLocation EllipsisLoc);

/// Construct a pack expansion type from the pattern of the pack
/// expansion.
TypeSourceInfo *CheckPackExpansion(TypeSourceInfo *Pattern,
                                   SourceLocation EllipsisLoc,
                                   Optional<unsigned> NumExpansions);

/// Construct a pack expansion type from the pattern of the pack
/// expansion.
QualType CheckPackExpansion(QualType Pattern,
                            SourceRange PatternRange,
                            SourceLocation EllipsisLoc,
                            Optional<unsigned> NumExpansions);

/// Invoked when parsing an expression followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Pattern The expression preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
ExprResult ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc);

/// Invoked when parsing an expression followed by an ellipsis, which
/// creates a pack expansion.
///
/// \param Pattern The expression preceding the ellipsis, which will become
/// the pattern of the pack expansion.
///
/// \param EllipsisLoc The location of the ellipsis.
ExprResult CheckPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc,
                              Optional<unsigned> NumExpansions);

/// Determine whether we could expand a pack expansion with the
/// given set of parameter packs into separate arguments by repeatedly
/// transforming the pattern.
///
/// \param EllipsisLoc The location of the ellipsis that identifies the
/// pack expansion.
///
/// \param PatternRange The source range that covers the entire pattern of
/// the pack expansion.
///
/// \param Unexpanded The set of unexpanded parameter packs within the
/// pattern.
///
/// \param ShouldExpand Will be set to \c true if the transformer should
/// expand the corresponding pack expansions into separate arguments. When
/// set, \c NumExpansions must also be set.
///
/// \param RetainExpansion Whether the caller should add an unexpanded
/// pack expansion after all of the expanded arguments. This is used
/// when extending explicitly-specified template argument packs per
/// C++0x [temp.arg.explicit]p9.
///
/// \param NumExpansions The number of separate arguments that will be in
/// the expanded form of the corresponding pack expansion. This is both an
/// input and an output parameter, which can be set by the caller if the
/// number of expansions is known a priori (e.g., due to a prior substitution)
/// and will be set by the callee when the number of expansions is known.
/// The callee must set this value when \c ShouldExpand is \c true; it may
/// set this value in other cases.
///
/// \returns true if an error occurred (e.g., because the parameter packs
/// are to be instantiated with arguments of different lengths), false
/// otherwise. If false, \c ShouldExpand (and possibly \c NumExpansions)
/// must be set.
bool CheckParameterPacksForExpansion(SourceLocation EllipsisLoc,
                                     SourceRange PatternRange,
                           ArrayRef<UnexpandedParameterPack> Unexpanded,
                           const MultiLevelTemplateArgumentList &TemplateArgs,
                                     bool &ShouldExpand,
                                     bool &RetainExpansion,
                                     Optional<unsigned> &NumExpansions);

/// Determine the number of arguments in the given pack expansion
/// type.
///
/// This routine assumes that the number of arguments in the expansion is
/// consistent across all of the unexpanded parameter packs in its pattern.
///
/// Returns an empty Optional if the type can't be expanded.
Optional<unsigned> getNumArgumentsInExpansion(QualType T,
    const MultiLevelTemplateArgumentList &TemplateArgs);

/// Determine whether the given declarator contains any unexpanded
/// parameter packs.
///
/// This routine is used by the parser to disambiguate function declarators
/// with an ellipsis prior to the ')', e.g.,
///
/// \code
///   void f(T...);
/// \endcode
///
/// To determine whether we have an (unnamed) function parameter pack or
/// a variadic function.
///
/// \returns true if the declarator contains any unexpanded parameter packs,
/// false otherwise.
bool containsUnexpandedParameterPacks(Declarator &D);

/// Returns the pattern of the pack expansion for a template argument.
///
/// \param OrigLoc The template argument to expand.
///
/// \param Ellipsis Will be set to the location of the ellipsis.
///
/// \param NumExpansions Will be set to the number of expansions that will
/// be generated from this pack expansion, if known a priori.
TemplateArgumentLoc getTemplateArgumentPackExpansionPattern(
    TemplateArgumentLoc OrigLoc,
    SourceLocation &Ellipsis,
    Optional<unsigned> &NumExpansions) const;

/// Given a template argument that contains an unexpanded parameter pack, but
/// which has already been substituted, attempt to determine the number of
/// elements that will be produced once this argument is fully-expanded.
///
/// This is intended for use when transforming 'sizeof...(Arg)' in order to
/// avoid actually expanding the pack where possible.
Optional<unsigned> getFullyPackExpandedSize(TemplateArgument Arg);

//===--------------------------------------------------------------------===//
// C++ Template Argument Deduction (C++ [temp.deduct])
//===--------------------------------------------------------------------===//

/// Adjust the type \p ArgFunctionType to match the calling convention,
/// noreturn, and optionally the exception specification of \p FunctionType.
/// Deduction often wants to ignore these properties when matching function
/// types.
QualType adjustCCAndNoReturn(QualType ArgFunctionType, QualType FunctionType,
                             bool AdjustExceptionSpec = false);

/// Describes the result of template argument deduction.
///
/// The TemplateDeductionResult enumeration describes the result of
/// template argument deduction, as returned from
/// DeduceTemplateArguments(). The separate TemplateDeductionInfo
/// structure provides additional information about the results of
/// template argument deduction, e.g., the deduced template argument
/// list (if successful) or the specific template parameters or
/// deduced arguments that were involved in the failure.
enum TemplateDeductionResult {
  /// Template argument deduction was successful.
  TDK_Success = 0,
  /// The declaration was invalid; do nothing.
  TDK_Invalid,
  /// Template argument deduction exceeded the maximum template
  /// instantiation depth (which has already been diagnosed).
  TDK_InstantiationDepth,
  /// Template argument deduction did not deduce a value
  /// for every template parameter.
  TDK_Incomplete,
  /// Template argument deduction did not deduce a value for every
  /// expansion of an expanded template parameter pack.
  TDK_IncompletePack,
  /// Template argument deduction produced inconsistent
  /// deduced values for the given template parameter.
  TDK_Inconsistent,
  /// Template argument deduction failed due to inconsistent
  /// cv-qualifiers on a template parameter type that would
  /// otherwise be deduced, e.g., we tried to deduce T in "const T"
  /// but were given a non-const "X".
  TDK_Underqualified,
  /// Substitution of the deduced template argument values
  /// resulted in an error.
  TDK_SubstitutionFailure,
  /// After substituting deduced template arguments, a dependent
  /// parameter type did not match the corresponding argument.
  TDK_DeducedMismatch,
  /// After substituting deduced template arguments, an element of
  /// a dependent parameter type did not match the corresponding element
  /// of the corresponding argument (when deducing from an initializer list).
  TDK_DeducedMismatchNested,
  /// A non-depnedent component of the parameter did not match the
  /// corresponding component of the argument.
  TDK_NonDeducedMismatch,
  /// When performing template argument deduction for a function
  /// template, there were too many call arguments.
  TDK_TooManyArguments,
  /// When performing template argument deduction for a function
  /// template, there were too few call arguments.
  TDK_TooFewArguments,
  /// The explicitly-specified template arguments were not valid
  /// template arguments for the given template.
  TDK_InvalidExplicitArguments,
  /// Checking non-dependent argument conversions failed.
  TDK_NonDependentConversionFailure,
  /// The deduced arguments did not satisfy the constraints associated
  /// with the template.
  TDK_ConstraintsNotSatisfied,
  /// Deduction failed; that's all we know.
  TDK_MiscellaneousDeductionFailure,
  /// CUDA Target attributes do not match.
  TDK_CUDATargetMismatch
};

TemplateDeductionResult
DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
                        const TemplateArgumentList &TemplateArgs,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult
DeduceTemplateArguments(VarTemplatePartialSpecializationDecl *Partial,
                        const TemplateArgumentList &TemplateArgs,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult SubstituteExplicitTemplateArguments(
    FunctionTemplateDecl *FunctionTemplate,
    TemplateArgumentListInfo &ExplicitTemplateArgs,
    SmallVectorImpl<DeducedTemplateArgument> &Deduced,
    SmallVectorImpl<QualType> &ParamTypes, QualType *FunctionType,
    sema::TemplateDeductionInfo &Info);

/// brief A function argument from which we performed template argument
// deduction for a call.
struct OriginalCallArg {
  OriginalCallArg(QualType OriginalParamType, bool DecomposedParam,
                  unsigned ArgIdx, QualType OriginalArgType)
      : OriginalParamType(OriginalParamType),
        DecomposedParam(DecomposedParam), ArgIdx(ArgIdx),
        OriginalArgType(OriginalArgType) {}

  QualType OriginalParamType;
  bool DecomposedParam;
  unsigned ArgIdx;
  QualType OriginalArgType;
};

TemplateDeductionResult FinishTemplateArgumentDeduction(
    FunctionTemplateDecl *FunctionTemplate,
    SmallVectorImpl<DeducedTemplateArgument> &Deduced,
    unsigned NumExplicitlySpecified, FunctionDecl *&Specialization,
    sema::TemplateDeductionInfo &Info,
    SmallVectorImpl<OriginalCallArg> const *OriginalCallArgs = nullptr,
    bool PartialOverloading = false,
    llvm::function_ref<bool()> CheckNonDependent = []{ return false; });

TemplateDeductionResult DeduceTemplateArguments(
    FunctionTemplateDecl *FunctionTemplate,
    TemplateArgumentListInfo *ExplicitTemplateArgs, ArrayRef<Expr *> Args,
    FunctionDecl *&Specialization, sema::TemplateDeductionInfo &Info,
    bool PartialOverloading,
    llvm::function_ref<bool(ArrayRef<QualType>)> CheckNonDependent);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        TemplateArgumentListInfo *ExplicitTemplateArgs,
                        QualType ArgFunctionType,
                        FunctionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info,
                        bool IsAddressOfFunction = false);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        QualType ToType,
                        CXXConversionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info);

TemplateDeductionResult
DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
                        TemplateArgumentListInfo *ExplicitTemplateArgs,
                        FunctionDecl *&Specialization,
                        sema::TemplateDeductionInfo &Info,
                        bool IsAddressOfFunction = false);

/// Substitute Replacement for \p auto in \p TypeWithAuto
QualType SubstAutoType(QualType TypeWithAuto, QualType Replacement);
/// Substitute Replacement for auto in TypeWithAuto
TypeSourceInfo* SubstAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
                                        QualType Replacement);
/// Completely replace the \c auto in \p TypeWithAuto by
/// \p Replacement. This does not retain any \c auto type sugar.
QualType ReplaceAutoType(QualType TypeWithAuto, QualType Replacement);
TypeSourceInfo *ReplaceAutoTypeSourceInfo(TypeSourceInfo *TypeWithAuto,
                                          QualType Replacement);

/// Result type of DeduceAutoType.
enum DeduceAutoResult {
  DAR_Succeeded,
  DAR_Failed,
  DAR_FailedAlreadyDiagnosed
};

DeduceAutoResult
DeduceAutoType(TypeSourceInfo *AutoType, Expr *&Initializer, QualType &Result,
               Optional<unsigned> DependentDeductionDepth = None,
               bool IgnoreConstraints = false);
DeduceAutoResult
DeduceAutoType(TypeLoc AutoTypeLoc, Expr *&Initializer, QualType &Result,
               Optional<unsigned> DependentDeductionDepth = None,
               bool IgnoreConstraints = false);
void DiagnoseAutoDeductionFailure(VarDecl *VDecl, Expr *Init);
bool DeduceReturnType(FunctionDecl *FD, SourceLocation Loc,
                      bool Diagnose = true);

/// Declare implicit deduction guides for a class template if we've
/// not already done so.
void DeclareImplicitDeductionGuides(TemplateDecl *Template,
                                    SourceLocation Loc);

QualType DeduceTemplateSpecializationFromInitializer(
    TypeSourceInfo *TInfo, const InitializedEntity &Entity,
    const InitializationKind &Kind, MultiExprArg Init);

QualType deduceVarTypeFromInitializer(VarDecl *VDecl, DeclarationName Name,
                                      QualType Type, TypeSourceInfo *TSI,
                                      SourceRange Range, bool DirectInit,
                                      Expr *Init);

TypeLoc getReturnTypeLoc(FunctionDecl *FD) const;

bool DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD,
                                      SourceLocation ReturnLoc,
                                      Expr *&RetExpr, AutoType *AT);

FunctionTemplateDecl *getMoreSpecializedTemplate(
    FunctionTemplateDecl *FT1, FunctionTemplateDecl *FT2, SourceLocation Loc,
    TemplatePartialOrderingContext TPOC, unsigned NumCallArguments1,
    unsigned NumCallArguments2, bool Reversed = false);
UnresolvedSetIterator
getMostSpecialized(UnresolvedSetIterator SBegin, UnresolvedSetIterator SEnd,
                   TemplateSpecCandidateSet &FailedCandidates,
                   SourceLocation Loc,
                   const PartialDiagnostic &NoneDiag,
                   const PartialDiagnostic &AmbigDiag,
                   const PartialDiagnostic &CandidateDiag,
                   bool Complain = true, QualType TargetType = QualType());

ClassTemplatePartialSpecializationDecl *
getMoreSpecializedPartialSpecialization(
                                ClassTemplatePartialSpecializationDecl *PS1,
                                ClassTemplatePartialSpecializationDecl *PS2,
                                SourceLocation Loc);

bool isMoreSpecializedThanPrimary(ClassTemplatePartialSpecializationDecl *T,
                                  sema::TemplateDeductionInfo &Info);

VarTemplatePartialSpecializationDecl *getMoreSpecializedPartialSpecialization(
    VarTemplatePartialSpecializationDecl *PS1,
    VarTemplatePartialSpecializationDecl *PS2, SourceLocation Loc);

bool isMoreSpecializedThanPrimary(VarTemplatePartialSpecializationDecl *T,
                                  sema::TemplateDeductionInfo &Info);

bool isTemplateTemplateParameterAtLeastAsSpecializedAs(
    TemplateParameterList *PParam, TemplateDecl *AArg, SourceLocation Loc);

void MarkUsedTemplateParameters(const Expr *E, bool OnlyDeduced,
                                unsigned Depth, llvm::SmallBitVector &Used);

void MarkUsedTemplateParameters(const TemplateArgumentList &TemplateArgs,
                                bool OnlyDeduced,
                                unsigned Depth,
                                llvm::SmallBitVector &Used);
void MarkDeducedTemplateParameters(
                                const FunctionTemplateDecl *FunctionTemplate,
                                llvm::SmallBitVector &Deduced) {
  return MarkDeducedTemplateParameters(Context, FunctionTemplate, Deduced);
}
static void MarkDeducedTemplateParameters(ASTContext &Ctx,
                                const FunctionTemplateDecl *FunctionTemplate,
                                llvm::SmallBitVector &Deduced);

//===--------------------------------------------------------------------===//
// C++ Template Instantiation
//

MultiLevelTemplateArgumentList
getTemplateInstantiationArgs(NamedDecl *D,
                             const TemplateArgumentList *Innermost = nullptr,
                             bool RelativeToPrimary = false,
                             const FunctionDecl *Pattern = nullptr);

/// A context in which code is being synthesized (where a source location
/// alone is not sufficient to identify the context). This covers template
/// instantiation and various forms of implicitly-generated functions.
struct CodeSynthesisContext {
  /// The kind of template instantiation we are performing
  enum SynthesisKind {
    /// We are instantiating a template declaration. The entity is
    /// the declaration we're instantiating (e.g., a CXXRecordDecl).
    TemplateInstantiation,

    /// We are instantiating a default argument for a template
    /// parameter. The Entity is the template parameter whose argument is
    /// being instantiated, the Template is the template, and the
    /// TemplateArgs/NumTemplateArguments provide the template arguments as
    /// specified.
    DefaultTemplateArgumentInstantiation,

    /// We are instantiating a default argument for a function.
    /// The Entity is the ParmVarDecl, and TemplateArgs/NumTemplateArgs
    /// provides the template arguments as specified.
    DefaultFunctionArgumentInstantiation,

    /// We are substituting explicit template arguments provided for
    /// a function template. The entity is a FunctionTemplateDecl.
    ExplicitTemplateArgumentSubstitution,

    /// We are substituting template argument determined as part of
    /// template argument deduction for either a class template
    /// partial specialization or a function template. The
    /// Entity is either a {Class|Var}TemplatePartialSpecializationDecl or
    /// a TemplateDecl.
    DeducedTemplateArgumentSubstitution,

    /// We are substituting prior template arguments into a new
    /// template parameter. The template parameter itself is either a
    /// NonTypeTemplateParmDecl or a TemplateTemplateParmDecl.
    PriorTemplateArgumentSubstitution,

    /// We are checking the validity of a default template argument that
    /// has been used when naming a template-id.
    DefaultTemplateArgumentChecking,

    /// We are computing the exception specification for a defaulted special
    /// member function.
    ExceptionSpecEvaluation,

    /// We are instantiating the exception specification for a function
    /// template which was deferred until it was needed.
    ExceptionSpecInstantiation,

    /// We are instantiating a requirement of a requires expression.
    RequirementInstantiation,

    /// We are checking the satisfaction of a nested requirement of a requires
    /// expression.
    NestedRequirementConstraintsCheck,

    /// We are declaring an implicit special member function.
    DeclaringSpecialMember,

    /// We are declaring an implicit 'operator==' for a defaulted
    /// 'operator<=>'.
    DeclaringImplicitEqualityComparison,

    /// We are defining a synthesized function (such as a defaulted special
    /// member).
    DefiningSynthesizedFunction,

    // We are checking the constraints associated with a constrained entity or
    // the constraint expression of a concept. This includes the checks that
    // atomic constraints have the type 'bool' and that they can be constant
    // evaluated.
    ConstraintsCheck,

    // We are substituting template arguments into a constraint expression.
    ConstraintSubstitution,

    // We are normalizing a constraint expression.
    ConstraintNormalization,

    // We are substituting into the parameter mapping of an atomic constraint
    // during normalization.
    ParameterMappingSubstitution,

    /// We are rewriting a comparison operator in terms of an operator<=>.
    RewritingOperatorAsSpaceship,

    /// We are initializing a structured binding.
    InitializingStructuredBinding,

    /// We are marking a class as __dllexport.
    MarkingClassDllexported,

    /// Added for Template instantiation observation.
    /// Memoization means we are _not_ instantiating a template because
    /// it is already instantiated (but we entered a context where we
    /// would have had to if it was not already instantiated).
    Memoization
  } Kind;

  /// Was the enclosing context a non-instantiation SFINAE context?
  bool SavedInNonInstantiationSFINAEContext;

  /// The point of instantiation or synthesis within the source code.
  SourceLocation PointOfInstantiation;

  /// The entity that is being synthesized.
  Decl *Entity;

  /// The template (or partial specialization) in which we are
  /// performing the instantiation, for substitutions of prior template
  /// arguments.
  NamedDecl *Template;

  /// The list of template arguments we are substituting, if they
  /// are not part of the entity.
  const TemplateArgument *TemplateArgs;

  // FIXME: Wrap this union around more members, or perhaps store the
  // kind-specific members in the RAII object owning the context.
  union {
    /// The number of template arguments in TemplateArgs.
    unsigned NumTemplateArgs;

    /// The special member being declared or defined.
    CXXSpecialMember SpecialMember;
  };

  ArrayRef<TemplateArgument> template_arguments() const {
    assert(Kind != DeclaringSpecialMember)((void)0);
    return {TemplateArgs, NumTemplateArgs};
  }

  /// The template deduction info object associated with the
  /// substitution or checking of explicit or deduced template arguments.
  sema::TemplateDeductionInfo *DeductionInfo;

  /// The source range that covers the construct that cause
  /// the instantiation, e.g., the template-id that causes a class
  /// template instantiation.
  SourceRange InstantiationRange;

  CodeSynthesisContext()
      : Kind(TemplateInstantiation),
        SavedInNonInstantiationSFINAEContext(false), Entity(nullptr),
        Template(nullptr), TemplateArgs(nullptr), NumTemplateArgs(0),
        DeductionInfo(nullptr) {}

  /// Determines whether this template is an actual instantiation
  /// that should be counted toward the maximum instantiation depth.
  bool isInstantiationRecord() const;
};

/// List of active code synthesis contexts.
///
/// This vector is treated as a stack. As synthesis of one entity requires
/// synthesis of another, additional contexts are pushed onto the stack.
SmallVector<CodeSynthesisContext, 16> CodeSynthesisContexts;

/// Specializations whose definitions are currently being instantiated.
llvm::DenseSet<std::pair<Decl *, unsigned>> InstantiatingSpecializations;

/// Non-dependent types used in templates that have already been instantiated
/// by some template instantiation.
llvm::DenseSet<QualType> InstantiatedNonDependentTypes;

/// Extra modules inspected when performing a lookup during a template
/// instantiation. Computed lazily.
SmallVector<Module*, 16> CodeSynthesisContextLookupModules;

/// Cache of additional modules that should be used for name lookup
/// within the current template instantiation. Computed lazily; use
/// getLookupModules() to get a complete set.
llvm::DenseSet<Module*> LookupModulesCache;

/// Get the set of additional modules that should be checked during
/// name lookup. A module and its imports become visible when instanting a
/// template defined within it.
llvm::DenseSet<Module*> &getLookupModules();

/// Map from the most recent declaration of a namespace to the most
/// recent visible declaration of that namespace.
llvm::DenseMap<NamedDecl*, NamedDecl*> VisibleNamespaceCache;

/// Whether we are in a SFINAE context that is not associated with
/// template instantiation.
///
/// This is used when setting up a SFINAE trap (\c see SFINAETrap) outside
/// of a template instantiation or template argument deduction.
bool InNonInstantiationSFINAEContext;

/// The number of \p CodeSynthesisContexts that are not template
/// instantiations and, therefore, should not be counted as part of the
/// instantiation depth.
///
/// When the instantiation depth reaches the user-configurable limit
/// \p LangOptions::InstantiationDepth we will abort instantiation.
// FIXME: Should we have a similar limit for other forms of synthesis?
unsigned NonInstantiationEntries;

/// The depth of the context stack at the point when the most recent
/// error or warning was produced.
///
/// This value is used to suppress printing of redundant context stacks
/// when there are multiple errors or warnings in the same instantiation.
// FIXME: Does this belong in Sema? It's tough to implement it anywhere else.
unsigned LastEmittedCodeSynthesisContextDepth = 0;

/// The template instantiation callbacks to trace or track
/// instantiations (objects can be chained).
///
/// This callbacks is used to print, trace or track template
/// instantiations as they are being constructed.
std::vector<std::unique_ptr<TemplateInstantiationCallback>>
    TemplateInstCallbacks;

/// The current index into pack expansion arguments that will be
/// used for substitution of parameter packs.
///
/// The pack expansion index will be -1 to indicate that parameter packs
/// should be instantiated as themselves. Otherwise, the index specifies
/// which argument within the parameter pack will be used for substitution.
int ArgumentPackSubstitutionIndex;

/// RAII object used to change the argument pack substitution index
/// within a \c Sema object.
///
/// See \c ArgumentPackSubstitutionIndex for more information.
class ArgumentPackSubstitutionIndexRAII {
  Sema &Self;
  int OldSubstitutionIndex;

public:
  ArgumentPackSubstitutionIndexRAII(Sema &Self, int NewSubstitutionIndex)
    : Self(Self), OldSubstitutionIndex(Self.ArgumentPackSubstitutionIndex) {
    Self.ArgumentPackSubstitutionIndex = NewSubstitutionIndex;
  }

  ~ArgumentPackSubstitutionIndexRAII() {
    Self.ArgumentPackSubstitutionIndex = OldSubstitutionIndex;
  }
};

friend class ArgumentPackSubstitutionRAII;

/// For each declaration that involved template argument deduction, the
/// set of diagnostics that were suppressed during that template argument
/// deduction.
///
/// FIXME: Serialize this structure to the AST file.
typedef llvm::DenseMap<Decl *, SmallVector<PartialDiagnosticAt, 1> >
  SuppressedDiagnosticsMap;
SuppressedDiagnosticsMap SuppressedDiagnostics;

/// A stack object to be created when performing template
/// instantiation.
///
/// Construction of an object of type \c InstantiatingTemplate
/// pushes the current instantiation onto the stack of active
/// instantiations. If the size of this stack exceeds the maximum
/// number of recursive template instantiations, construction
/// produces an error and evaluates true.
///
/// Destruction of this object will pop the named instantiation off
/// the stack.
struct InstantiatingTemplate {
  /// Note that we are instantiating a class template,
  /// function template, variable template, alias template,
  /// or a member thereof.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        Decl *Entity,
                        SourceRange InstantiationRange = SourceRange());

  struct ExceptionSpecification {};
  /// Note that we are instantiating an exception specification
  /// of a function template.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        FunctionDecl *Entity, ExceptionSpecification,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating a default argument in a
  /// template-id.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateParameter Param, TemplateDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are substituting either explicitly-specified or
  /// deduced template arguments during function template argument deduction.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        FunctionTemplateDecl *FunctionTemplate,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        CodeSynthesisContext::SynthesisKind Kind,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a class template declaration.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a class template partial
  /// specialization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ClassTemplatePartialSpecializationDecl *PartialSpec,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating as part of template
  /// argument deduction for a variable template partial
  /// specialization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        VarTemplatePartialSpecializationDecl *PartialSpec,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are instantiating a default argument for a function
  /// parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ParmVarDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we are substituting prior template arguments into a
  /// non-type parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        NamedDecl *Template,
                        NonTypeTemplateParmDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  /// Note that we are substituting prior template arguments into a
  /// template template parameter.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        NamedDecl *Template,
                        TemplateTemplateParmDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  /// Note that we are checking the default template argument
  /// against the template parameter for a given template-id.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        TemplateDecl *Template,
                        NamedDecl *Param,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  struct ConstraintsCheck {};
  /// \brief Note that we are checking the constraints associated with some
  /// constrained entity (a concept declaration or a template with associated
  /// constraints).
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintsCheck, NamedDecl *Template,
                        ArrayRef<TemplateArgument> TemplateArgs,
                        SourceRange InstantiationRange);

  struct ConstraintSubstitution {};
  /// \brief Note that we are checking a constraint expression associated
  /// with a template declaration or as part of the satisfaction check of a
  /// concept.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintSubstitution, NamedDecl *Template,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange);

  struct ConstraintNormalization {};
  /// \brief Note that we are normalizing a constraint expression.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ConstraintNormalization, NamedDecl *Template,
                        SourceRange InstantiationRange);

  struct ParameterMappingSubstitution {};
  /// \brief Note that we are subtituting into the parameter mapping of an
  /// atomic constraint during constraint normalization.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        ParameterMappingSubstitution, NamedDecl *Template,
                        SourceRange InstantiationRange);

  /// \brief Note that we are substituting template arguments into a part of
  /// a requirement of a requires expression.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        concepts::Requirement *Req,
                        sema::TemplateDeductionInfo &DeductionInfo,
                        SourceRange InstantiationRange = SourceRange());

  /// \brief Note that we are checking the satisfaction of the constraint
  /// expression inside of a nested requirement.
  InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation,
                        concepts::NestedRequirement *Req, ConstraintsCheck,
                        SourceRange InstantiationRange = SourceRange());

  /// Note that we have finished instantiating this template.
  void Clear();

  ~InstantiatingTemplate() { Clear(); }

  /// Determines whether we have exceeded the maximum
  /// recursive template instantiations.
  bool isInvalid() const { return Invalid; }

  /// Determine whether we are already instantiating this
  /// specialization in some surrounding active instantiation.
  bool isAlreadyInstantiating() const { return AlreadyInstantiating; }

private:
  Sema &SemaRef;
  bool Invalid;
  bool AlreadyInstantiating;
  bool CheckInstantiationDepth(SourceLocation PointOfInstantiation,
                               SourceRange InstantiationRange);

  InstantiatingTemplate(
      Sema &SemaRef, CodeSynthesisContext::SynthesisKind Kind,
      SourceLocation PointOfInstantiation, SourceRange InstantiationRange,
      Decl *Entity, NamedDecl *Template = nullptr,
      ArrayRef<TemplateArgument> TemplateArgs = None,
      sema::TemplateDeductionInfo *DeductionInfo = nullptr);

  InstantiatingTemplate(const InstantiatingTemplate&) = delete;

  InstantiatingTemplate&
  operator=(const InstantiatingTemplate&) = delete;
};

void pushCodeSynthesisContext(CodeSynthesisContext Ctx);
void popCodeSynthesisContext();

/// Determine whether we are currently performing template instantiation.
bool inTemplateInstantiation() const {
  return CodeSynthesisContexts.size() > NonInstantiationEntries;
}

void PrintContextStack() {
  if (!CodeSynthesisContexts.empty() &&
      CodeSynthesisContexts.size() != LastEmittedCodeSynthesisContextDepth) {
    PrintInstantiationStack();
    LastEmittedCodeSynthesisContextDepth = CodeSynthesisContexts.size();
  }
  if (PragmaAttributeCurrentTargetDecl)
    PrintPragmaAttributeInstantiationPoint();
}
void PrintInstantiationStack();

void PrintPragmaAttributeInstantiationPoint();

/// Determines whether we are currently in a context where
/// template argument substitution failures are not considered
/// errors.
///
/// \returns An empty \c Optional if we're not in a SFINAE context.
/// Otherwise, contains a pointer that, if non-NULL, contains the nearest
/// template-deduction context object, which can be used to capture
/// diagnostics that will be suppressed.
Optional<sema::TemplateDeductionInfo *> isSFINAEContext() const;

/// Determines whether we are currently in a context that
/// is not evaluated as per C++ [expr] p5.
bool isUnevaluatedContext() const {
  assert(!ExprEvalContexts.empty() &&((void)0)
         "Must be in an expression evaluation context")((void)0);
  return ExprEvalContexts.back().isUnevaluated();
6
←
Calling 'ExpressionEvaluationContextRecord::isUnevaluated'→
11
←
Returning from 'ExpressionEvaluationContextRecord::isUnevaluated'→
12
←
Returning zero, which participates in a condition later→
}

/// RAII class used to determine whether SFINAE has
/// trapped any errors that occur during template argument
/// deduction.
class SFINAETrap {
  Sema &SemaRef;
  unsigned PrevSFINAEErrors;
  bool PrevInNonInstantiationSFINAEContext;
  bool PrevAccessCheckingSFINAE;
  bool PrevLastDiagnosticIgnored;

public:
  explicit SFINAETrap(Sema &SemaRef, bool AccessCheckingSFINAE = false)
    : SemaRef(SemaRef), PrevSFINAEErrors(SemaRef.NumSFINAEErrors),
      PrevInNonInstantiationSFINAEContext(
                                    SemaRef.InNonInstantiationSFINAEContext),
      PrevAccessCheckingSFINAE(SemaRef.AccessCheckingSFINAE),
      PrevLastDiagnosticIgnored(
          SemaRef.getDiagnostics().isLastDiagnosticIgnored())
  {
    if (!SemaRef.isSFINAEContext())
      SemaRef.InNonInstantiationSFINAEContext = true;
    SemaRef.AccessCheckingSFINAE = AccessCheckingSFINAE;
  }

  ~SFINAETrap() {
    SemaRef.NumSFINAEErrors = PrevSFINAEErrors;
    SemaRef.InNonInstantiationSFINAEContext
      = PrevInNonInstantiationSFINAEContext;
    SemaRef.AccessCheckingSFINAE = PrevAccessCheckingSFINAE;
    SemaRef.getDiagnostics().setLastDiagnosticIgnored(
        PrevLastDiagnosticIgnored);
  }

  /// Determine whether any SFINAE errors have been trapped.
  bool hasErrorOccurred() const {
    return SemaRef.NumSFINAEErrors > PrevSFINAEErrors;
  }
};

/// RAII class used to indicate that we are performing provisional
/// semantic analysis to determine the validity of a construct, so
/// typo-correction and diagnostics in the immediate context (not within
/// implicitly-instantiated templates) should be suppressed.
class TentativeAnalysisScope {
  Sema &SemaRef;
  // FIXME: Using a SFINAETrap for this is a hack.
  SFINAETrap Trap;
  bool PrevDisableTypoCorrection;
public:
  explicit TentativeAnalysisScope(Sema &SemaRef)
      : SemaRef(SemaRef), Trap(SemaRef, true),
        PrevDisableTypoCorrection(SemaRef.DisableTypoCorrection) {
    SemaRef.DisableTypoCorrection = true;
  }
  ~TentativeAnalysisScope() {
    SemaRef.DisableTypoCorrection = PrevDisableTypoCorrection;
  }
};

/// The current instantiation scope used to store local
/// variables.
LocalInstantiationScope *CurrentInstantiationScope;

/// Tracks whether we are in a context where typo correction is
/// disabled.
bool DisableTypoCorrection;

/// The number of typos corrected by CorrectTypo.
unsigned TyposCorrected;

typedef llvm::SmallSet<SourceLocation, 2> SrcLocSet;
typedef llvm::DenseMap<IdentifierInfo *, SrcLocSet> IdentifierSourceLocations;

/// A cache containing identifiers for which typo correction failed and
/// their locations, so that repeated attempts to correct an identifier in a
/// given location are ignored if typo correction already failed for it.
IdentifierSourceLocations TypoCorrectionFailures;

/// Worker object for performing CFG-based warnings.
sema::AnalysisBasedWarnings AnalysisWarnings;
threadSafety::BeforeSet *ThreadSafetyDeclCache;

/// An entity for which implicit template instantiation is required.
///
/// The source location associated with the declaration is the first place in
/// the source code where the declaration was "used". It is not necessarily
/// the point of instantiation (which will be either before or after the
/// namespace-scope declaration that triggered this implicit instantiation),
/// However, it is the location that diagnostics should generally refer to,
/// because users will need to know what code triggered the instantiation.
typedef std::pair<ValueDecl *, SourceLocation> PendingImplicitInstantiation;

/// The queue of implicit template instantiations that are required
/// but have not yet been performed.
std::deque<PendingImplicitInstantiation> PendingInstantiations;

/// Queue of implicit template instantiations that cannot be performed
/// eagerly.
SmallVector<PendingImplicitInstantiation, 1> LateParsedInstantiations;

class GlobalEagerInstantiationScope {
public:
  GlobalEagerInstantiationScope(Sema &S, bool Enabled)
      : S(S), Enabled(Enabled) {
    if (!Enabled) return;

    SavedPendingInstantiations.swap(S.PendingInstantiations);
    SavedVTableUses.swap(S.VTableUses);
  }

  void perform() {
    if (Enabled) {
      S.DefineUsedVTables();
      S.PerformPendingInstantiations();
    }
  }

  ~GlobalEagerInstantiationScope() {
    if (!Enabled) return;

    // Restore the set of pending vtables.
    assert(S.VTableUses.empty() &&((void)0)
           "VTableUses should be empty before it is discarded.")((void)0);
    S.VTableUses.swap(SavedVTableUses);

    // Restore the set of pending implicit instantiations.
    if (S.TUKind != TU_Prefix || !S.LangOpts.PCHInstantiateTemplates) {
      assert(S.PendingInstantiations.empty() &&((void)0)
             "PendingInstantiations should be empty before it is discarded.")((void)0);
      S.PendingInstantiations.swap(SavedPendingInstantiations);
    } else {
      // Template instantiations in the PCH may be delayed until the TU.
      S.PendingInstantiations.swap(SavedPendingInstantiations);
      S.PendingInstantiations.insert(S.PendingInstantiations.end(),
                                     SavedPendingInstantiations.begin(),
                                     SavedPendingInstantiations.end());
    }
  }

private:
  Sema &S;
  SmallVector<VTableUse, 16> SavedVTableUses;
  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
  bool Enabled;
};

/// The queue of implicit template instantiations that are required
/// and must be performed within the current local scope.
///
/// This queue is only used for member functions of local classes in
/// templates, which must be instantiated in the same scope as their
/// enclosing function, so that they can reference function-local
/// types, static variables, enumerators, etc.
std::deque<PendingImplicitInstantiation> PendingLocalImplicitInstantiations;

class LocalEagerInstantiationScope {
public:
  LocalEagerInstantiationScope(Sema &S) : S(S) {
    SavedPendingLocalImplicitInstantiations.swap(
        S.PendingLocalImplicitInstantiations);
  }

  void perform() { S.PerformPendingInstantiations(/*LocalOnly=*/true); }

  ~LocalEagerInstantiationScope() {
    assert(S.PendingLocalImplicitInstantiations.empty() &&((void)0)
           "there shouldn't be any pending local implicit instantiations")((void)0);
    SavedPendingLocalImplicitInstantiations.swap(
        S.PendingLocalImplicitInstantiations);
  }

private:
  Sema &S;
  std::deque<PendingImplicitInstantiation>
      SavedPendingLocalImplicitInstantiations;
};

/// A helper class for building up ExtParameterInfos.
class ExtParameterInfoBuilder {
  SmallVector<FunctionProtoType::ExtParameterInfo, 16> Infos;
  bool HasInteresting = false;

public:
  /// Set the ExtParameterInfo for the parameter at the given index,
  ///
  void set(unsigned index, FunctionProtoType::ExtParameterInfo info) {
    assert(Infos.size() <= index)((void)0);
    Infos.resize(index);
    Infos.push_back(info);

    if (!HasInteresting)
      HasInteresting = (info != FunctionProtoType::ExtParameterInfo());
  }

  /// Return a pointer (suitable for setting in an ExtProtoInfo) to the
  /// ExtParameterInfo array we've built up.
  const FunctionProtoType::ExtParameterInfo *
  getPointerOrNull(unsigned numParams) {
    if (!HasInteresting) return nullptr;
    Infos.resize(numParams);
    return Infos.data();
  }
};

void PerformPendingInstantiations(bool LocalOnly = false);

TypeSourceInfo *SubstType(TypeSourceInfo *T,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                          SourceLocation Loc, DeclarationName Entity,
                          bool AllowDeducedTST = false);

QualType SubstType(QualType T,
                   const MultiLevelTemplateArgumentList &TemplateArgs,
                   SourceLocation Loc, DeclarationName Entity);

TypeSourceInfo *SubstType(TypeLoc TL,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                          SourceLocation Loc, DeclarationName Entity);

TypeSourceInfo *SubstFunctionDeclType(TypeSourceInfo *T,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                                      SourceLocation Loc,
                                      DeclarationName Entity,
                                      CXXRecordDecl *ThisContext,
                                      Qualifiers ThisTypeQuals);
void SubstExceptionSpec(FunctionDecl *New, const FunctionProtoType *Proto,
                        const MultiLevelTemplateArgumentList &Args);
bool SubstExceptionSpec(SourceLocation Loc,
                        FunctionProtoType::ExceptionSpecInfo &ESI,
                        SmallVectorImpl<QualType> &ExceptionStorage,
                        const MultiLevelTemplateArgumentList &Args);
ParmVarDecl *SubstParmVarDecl(ParmVarDecl *D,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                              int indexAdjustment,
                              Optional<unsigned> NumExpansions,
                              bool ExpectParameterPack);
bool SubstParmTypes(SourceLocation Loc, ArrayRef<ParmVarDecl *> Params,
                    const FunctionProtoType::ExtParameterInfo *ExtParamInfos,
                    const MultiLevelTemplateArgumentList &TemplateArgs,
                    SmallVectorImpl<QualType> &ParamTypes,
                    SmallVectorImpl<ParmVarDecl *> *OutParams,
                    ExtParameterInfoBuilder &ParamInfos);
ExprResult SubstExpr(Expr *E,
                     const MultiLevelTemplateArgumentList &TemplateArgs);

/// Substitute the given template arguments into a list of
/// expressions, expanding pack expansions if required.
///
/// \param Exprs The list of expressions to substitute into.
///
/// \param IsCall Whether this is some form of call, in which case
/// default arguments will be dropped.
///
/// \param TemplateArgs The set of template arguments to substitute.
///
/// \param Outputs Will receive all of the substituted arguments.
///
/// \returns true if an error occurred, false otherwise.
bool SubstExprs(ArrayRef<Expr *> Exprs, bool IsCall,
                const MultiLevelTemplateArgumentList &TemplateArgs,
                SmallVectorImpl<Expr *> &Outputs);

StmtResult SubstStmt(Stmt *S,
                     const MultiLevelTemplateArgumentList &TemplateArgs);

TemplateParameterList *
SubstTemplateParams(TemplateParameterList *Params, DeclContext *Owner,
                    const MultiLevelTemplateArgumentList &TemplateArgs);

bool
SubstTemplateArguments(ArrayRef<TemplateArgumentLoc> Args,
                       const MultiLevelTemplateArgumentList &TemplateArgs,
                       TemplateArgumentListInfo &Outputs);


Decl *SubstDecl(Decl *D, DeclContext *Owner,
                const MultiLevelTemplateArgumentList &TemplateArgs);

/// Substitute the name and return type of a defaulted 'operator<=>' to form
/// an implicit 'operator=='.
FunctionDecl *SubstSpaceshipAsEqualEqual(CXXRecordDecl *RD,
                                         FunctionDecl *Spaceship);

ExprResult SubstInitializer(Expr *E,
                     const MultiLevelTemplateArgumentList &TemplateArgs,
                     bool CXXDirectInit);

bool
SubstBaseSpecifiers(CXXRecordDecl *Instantiation,
                    CXXRecordDecl *Pattern,
                    const MultiLevelTemplateArgumentList &TemplateArgs);

bool
InstantiateClass(SourceLocation PointOfInstantiation,
                 CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern,
                 const MultiLevelTemplateArgumentList &TemplateArgs,
                 TemplateSpecializationKind TSK,
                 bool Complain = true);

bool InstantiateEnum(SourceLocation PointOfInstantiation,
                     EnumDecl *Instantiation, EnumDecl *Pattern,
                     const MultiLevelTemplateArgumentList &TemplateArgs,
                     TemplateSpecializationKind TSK);

bool InstantiateInClassInitializer(
    SourceLocation PointOfInstantiation, FieldDecl *Instantiation,
    FieldDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs);

struct LateInstantiatedAttribute {
  const Attr *TmplAttr;
  LocalInstantiationScope *Scope;
  Decl *NewDecl;

  LateInstantiatedAttribute(const Attr *A, LocalInstantiationScope *S,
                            Decl *D)
    : TmplAttr(A), Scope(S), NewDecl(D)
  { }
};
typedef SmallVector<LateInstantiatedAttribute, 16> LateInstantiatedAttrVec;

void InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
                      const Decl *Pattern, Decl *Inst,
                      LateInstantiatedAttrVec *LateAttrs = nullptr,
                      LocalInstantiationScope *OuterMostScope = nullptr);

void
InstantiateAttrsForDecl(const MultiLevelTemplateArgumentList &TemplateArgs,
                        const Decl *Pattern, Decl *Inst,
                        LateInstantiatedAttrVec *LateAttrs = nullptr,
                        LocalInstantiationScope *OuterMostScope = nullptr);

void InstantiateDefaultCtorDefaultArgs(CXXConstructorDecl *Ctor);

bool usesPartialOrExplicitSpecialization(
    SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec);

bool
InstantiateClassTemplateSpecialization(SourceLocation PointOfInstantiation,
                         ClassTemplateSpecializationDecl *ClassTemplateSpec,
                         TemplateSpecializationKind TSK,
                         bool Complain = true);

void InstantiateClassMembers(SourceLocation PointOfInstantiation,
                             CXXRecordDecl *Instantiation,
                          const MultiLevelTemplateArgumentList &TemplateArgs,
                             TemplateSpecializationKind TSK);

void InstantiateClassTemplateSpecializationMembers(
                                        SourceLocation PointOfInstantiation,
                         ClassTemplateSpecializationDecl *ClassTemplateSpec,
                                              TemplateSpecializationKind TSK);

NestedNameSpecifierLoc
SubstNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
                         const MultiLevelTemplateArgumentList &TemplateArgs);

DeclarationNameInfo
SubstDeclarationNameInfo(const DeclarationNameInfo &NameInfo,
                         const MultiLevelTemplateArgumentList &TemplateArgs);
TemplateName
SubstTemplateName(NestedNameSpecifierLoc QualifierLoc, TemplateName Name,
                  SourceLocation Loc,
                  const MultiLevelTemplateArgumentList &TemplateArgs);
bool Subst(const TemplateArgumentLoc *Args, unsigned NumArgs,
           TemplateArgumentListInfo &Result,
           const MultiLevelTemplateArgumentList &TemplateArgs);

bool InstantiateDefaultArgument(SourceLocation CallLoc, FunctionDecl *FD,
                                ParmVarDecl *Param);
void InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
                              FunctionDecl *Function);
bool CheckInstantiatedFunctionTemplateConstraints(
    SourceLocation PointOfInstantiation, FunctionDecl *Decl,
    ArrayRef<TemplateArgument> TemplateArgs,
    ConstraintSatisfaction &Satisfaction);
FunctionDecl *InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
                                             const TemplateArgumentList *Args,
                                             SourceLocation Loc);
void InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
                                   FunctionDecl *Function,
                                   bool Recursive = false,
                                   bool DefinitionRequired = false,
                                   bool AtEndOfTU = false);
VarTemplateSpecializationDecl *BuildVarTemplateInstantiation(
    VarTemplateDecl *VarTemplate, VarDecl *FromVar,
    const TemplateArgumentList &TemplateArgList,
    const TemplateArgumentListInfo &TemplateArgsInfo,
    SmallVectorImpl<TemplateArgument> &Converted,
    SourceLocation PointOfInstantiation,
    LateInstantiatedAttrVec *LateAttrs = nullptr,
    LocalInstantiationScope *StartingScope = nullptr);
VarTemplateSpecializationDecl *CompleteVarTemplateSpecializationDecl(
    VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
    const MultiLevelTemplateArgumentList &TemplateArgs);
void
BuildVariableInstantiation(VarDecl *NewVar, VarDecl *OldVar,
                           const MultiLevelTemplateArgumentList &TemplateArgs,
                           LateInstantiatedAttrVec *LateAttrs,
                           DeclContext *Owner,
                           LocalInstantiationScope *StartingScope,
                           bool InstantiatingVarTemplate = false,
                           VarTemplateSpecializationDecl *PrevVTSD = nullptr);

void InstantiateVariableInitializer(
    VarDecl *Var, VarDecl *OldVar,
    const MultiLevelTemplateArgumentList &TemplateArgs);
void InstantiateVariableDefinition(SourceLocation PointOfInstantiation,
                                   VarDecl *Var, bool Recursive = false,
                                   bool DefinitionRequired = false,
                                   bool AtEndOfTU = false);

void InstantiateMemInitializers(CXXConstructorDecl *New,
                                const CXXConstructorDecl *Tmpl,
                          const MultiLevelTemplateArgumentList &TemplateArgs);

NamedDecl *FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
                        const MultiLevelTemplateArgumentList &TemplateArgs,
                        bool FindingInstantiatedContext = false);
DeclContext *FindInstantiatedContext(SourceLocation Loc, DeclContext *DC,
                        const MultiLevelTemplateArgumentList &TemplateArgs);

// Objective-C declarations.
enum ObjCContainerKind {
  OCK_None = -1,
  OCK_Interface = 0,
  OCK_Protocol,
  OCK_Category,
  OCK_ClassExtension,
  OCK_Implementation,
  OCK_CategoryImplementation
};
ObjCContainerKind getObjCContainerKind() const;

DeclResult actOnObjCTypeParam(Scope *S,
                              ObjCTypeParamVariance variance,
                              SourceLocation varianceLoc,
                              unsigned index,
                              IdentifierInfo *paramName,
                              SourceLocation paramLoc,
                              SourceLocation colonLoc,
                              ParsedType typeBound);

ObjCTypeParamList *actOnObjCTypeParamList(Scope *S, SourceLocation lAngleLoc,
                                          ArrayRef<Decl *> typeParams,
                                          SourceLocation rAngleLoc);
void popObjCTypeParamList(Scope *S, ObjCTypeParamList *typeParamList);

Decl *ActOnStartClassInterface(
    Scope *S, SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
    IdentifierInfo *SuperName, SourceLocation SuperLoc,
    ArrayRef<ParsedType> SuperTypeArgs, SourceRange SuperTypeArgsRange,
    Decl *const *ProtoRefs, unsigned NumProtoRefs,
    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
    const ParsedAttributesView &AttrList);

void ActOnSuperClassOfClassInterface(Scope *S,
                                     SourceLocation AtInterfaceLoc,
                                     ObjCInterfaceDecl *IDecl,
                                     IdentifierInfo *ClassName,
                                     SourceLocation ClassLoc,
                                     IdentifierInfo *SuperName,
                                     SourceLocation SuperLoc,
                                     ArrayRef<ParsedType> SuperTypeArgs,
                                     SourceRange SuperTypeArgsRange);

void ActOnTypedefedProtocols(SmallVectorImpl<Decl *> &ProtocolRefs,
                             SmallVectorImpl<SourceLocation> &ProtocolLocs,
                             IdentifierInfo *SuperName,
                             SourceLocation SuperLoc);

Decl *ActOnCompatibilityAlias(
                  SourceLocation AtCompatibilityAliasLoc,
                  IdentifierInfo *AliasName,  SourceLocation AliasLocation,
                  IdentifierInfo *ClassName, SourceLocation ClassLocation);

bool CheckForwardProtocolDeclarationForCircularDependency(
  IdentifierInfo *PName,
  SourceLocation &PLoc, SourceLocation PrevLoc,
  const ObjCList<ObjCProtocolDecl> &PList);

Decl *ActOnStartProtocolInterface(
    SourceLocation AtProtoInterfaceLoc, IdentifierInfo *ProtocolName,
    SourceLocation ProtocolLoc, Decl *const *ProtoRefNames,
    unsigned NumProtoRefs, const SourceLocation *ProtoLocs,
    SourceLocation EndProtoLoc, const ParsedAttributesView &AttrList);

Decl *ActOnStartCategoryInterface(
    SourceLocation AtInterfaceLoc, IdentifierInfo *ClassName,
    SourceLocation ClassLoc, ObjCTypeParamList *typeParamList,
    IdentifierInfo *CategoryName, SourceLocation CategoryLoc,
    Decl *const *ProtoRefs, unsigned NumProtoRefs,
    const SourceLocation *ProtoLocs, SourceLocation EndProtoLoc,
    const ParsedAttributesView &AttrList);

Decl *ActOnStartClassImplementation(SourceLocation AtClassImplLoc,
                                    IdentifierInfo *ClassName,
                                    SourceLocation ClassLoc,
                                    IdentifierInfo *SuperClassname,
                                    SourceLocation SuperClassLoc,
                                    const ParsedAttributesView &AttrList);

Decl *ActOnStartCategoryImplementation(SourceLocation AtCatImplLoc,
                                       IdentifierInfo *ClassName,
                                       SourceLocation ClassLoc,
                                       IdentifierInfo *CatName,
                                       SourceLocation CatLoc,
                                       const ParsedAttributesView &AttrList);

DeclGroupPtrTy ActOnFinishObjCImplementation(Decl *ObjCImpDecl,
                                             ArrayRef<Decl *> Decls);

DeclGroupPtrTy ActOnForwardClassDeclaration(SourceLocation Loc,
                 IdentifierInfo **IdentList,
                 SourceLocation *IdentLocs,
                 ArrayRef<ObjCTypeParamList *> TypeParamLists,
                 unsigned NumElts);

DeclGroupPtrTy
ActOnForwardProtocolDeclaration(SourceLocation AtProtoclLoc,
                                ArrayRef<IdentifierLocPair> IdentList,
                                const ParsedAttributesView &attrList);

void FindProtocolDeclaration(bool WarnOnDeclarations, bool ForObjCContainer,
                             ArrayRef<IdentifierLocPair> ProtocolId,
                             SmallVectorImpl<Decl *> &Protocols);

void DiagnoseTypeArgsAndProtocols(IdentifierInfo *ProtocolId,
                                  SourceLocation ProtocolLoc,
                                  IdentifierInfo *TypeArgId,
                                  SourceLocation TypeArgLoc,
                                  bool SelectProtocolFirst = false);

/// Given a list of identifiers (and their locations), resolve the
/// names to either Objective-C protocol qualifiers or type
/// arguments, as appropriate.
void actOnObjCTypeArgsOrProtocolQualifiers(
       Scope *S,
       ParsedType baseType,
       SourceLocation lAngleLoc,
       ArrayRef<IdentifierInfo *> identifiers,
       ArrayRef<SourceLocation> identifierLocs,
       SourceLocation rAngleLoc,
       SourceLocation &typeArgsLAngleLoc,
       SmallVectorImpl<ParsedType> &typeArgs,
       SourceLocation &typeArgsRAngleLoc,
       SourceLocation &protocolLAngleLoc,
       SmallVectorImpl<Decl *> &protocols,
       SourceLocation &protocolRAngleLoc,
       bool warnOnIncompleteProtocols);

/// Build a an Objective-C protocol-qualified 'id' type where no
/// base type was specified.
TypeResult actOnObjCProtocolQualifierType(
             SourceLocation lAngleLoc,
             ArrayRef<Decl *> protocols,
             ArrayRef<SourceLocation> protocolLocs,
             SourceLocation rAngleLoc);

/// Build a specialized and/or protocol-qualified Objective-C type.
TypeResult actOnObjCTypeArgsAndProtocolQualifiers(
             Scope *S,
             SourceLocation Loc,
             ParsedType BaseType,
             SourceLocation TypeArgsLAngleLoc,
             ArrayRef<ParsedType> TypeArgs,
             SourceLocation TypeArgsRAngleLoc,
             SourceLocation ProtocolLAngleLoc,
             ArrayRef<Decl *> Protocols,
             ArrayRef<SourceLocation> ProtocolLocs,
             SourceLocation ProtocolRAngleLoc);

/// Build an Objective-C type parameter type.
QualType BuildObjCTypeParamType(const ObjCTypeParamDecl *Decl,
                                SourceLocation ProtocolLAngleLoc,
                                ArrayRef<ObjCProtocolDecl *> Protocols,
                                ArrayRef<SourceLocation> ProtocolLocs,
                                SourceLocation ProtocolRAngleLoc,
                                bool FailOnError = false);

/// Build an Objective-C object pointer type.
QualType BuildObjCObjectType(QualType BaseType,
                             SourceLocation Loc,
                             SourceLocation TypeArgsLAngleLoc,
                             ArrayRef<TypeSourceInfo *> TypeArgs,
                             SourceLocation TypeArgsRAngleLoc,
                             SourceLocation ProtocolLAngleLoc,
                             ArrayRef<ObjCProtocolDecl *> Protocols,
                             ArrayRef<SourceLocation> ProtocolLocs,
                             SourceLocation ProtocolRAngleLoc,
                             bool FailOnError = false);

/// Ensure attributes are consistent with type.
/// \param [in, out] Attributes The attributes to check; they will
/// be modified to be consistent with \p PropertyTy.
void CheckObjCPropertyAttributes(Decl *PropertyPtrTy,
                                 SourceLocation Loc,
                                 unsigned &Attributes,
                                 bool propertyInPrimaryClass);

/// Process the specified property declaration and create decls for the
/// setters and getters as needed.
/// \param property The property declaration being processed
void ProcessPropertyDecl(ObjCPropertyDecl *property);


void DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
                              ObjCPropertyDecl *SuperProperty,
                              const IdentifierInfo *Name,
                              bool OverridingProtocolProperty);

void DiagnoseClassExtensionDupMethods(ObjCCategoryDecl *CAT,
                                      ObjCInterfaceDecl *ID);

Decl *ActOnAtEnd(Scope *S, SourceRange AtEnd,
                 ArrayRef<Decl *> allMethods = None,
                 ArrayRef<DeclGroupPtrTy> allTUVars = None);

Decl *ActOnProperty(Scope *S, SourceLocation AtLoc,
                    SourceLocation LParenLoc,
                    FieldDeclarator &FD, ObjCDeclSpec &ODS,
                    Selector GetterSel, Selector SetterSel,
                    tok::ObjCKeywordKind MethodImplKind,
                    DeclContext *lexicalDC = nullptr);

Decl *ActOnPropertyImplDecl(Scope *S,
                            SourceLocation AtLoc,
                            SourceLocation PropertyLoc,
                            bool ImplKind,
                            IdentifierInfo *PropertyId,
                            IdentifierInfo *PropertyIvar,
                            SourceLocation PropertyIvarLoc,
                            ObjCPropertyQueryKind QueryKind);

enum ObjCSpecialMethodKind {
  OSMK_None,
  OSMK_Alloc,
  OSMK_New,
  OSMK_Copy,
  OSMK_RetainingInit,
  OSMK_NonRetainingInit
};

struct ObjCArgInfo {
  IdentifierInfo *Name;
  SourceLocation NameLoc;
  // The Type is null if no type was specified, and the DeclSpec is invalid
  // in this case.
  ParsedType Type;
  ObjCDeclSpec DeclSpec;

  /// ArgAttrs - Attribute list for this argument.
  ParsedAttributesView ArgAttrs;
};

Decl *ActOnMethodDeclaration(
    Scope *S,
    SourceLocation BeginLoc, // location of the + or -.
    SourceLocation EndLoc,   // location of the ; or {.
    tok::TokenKind MethodType, ObjCDeclSpec &ReturnQT, ParsedType ReturnType,
    ArrayRef<SourceLocation> SelectorLocs, Selector Sel,
    // optional arguments. The number of types/arguments is obtained
    // from the Sel.getNumArgs().
    ObjCArgInfo *ArgInfo, DeclaratorChunk::ParamInfo *CParamInfo,
    unsigned CNumArgs, // c-style args
    const ParsedAttributesView &AttrList, tok::ObjCKeywordKind MethodImplKind,
    bool isVariadic, bool MethodDefinition);

ObjCMethodDecl *LookupMethodInQualifiedType(Selector Sel,
                                            const ObjCObjectPointerType *OPT,
                                            bool IsInstance);
ObjCMethodDecl *LookupMethodInObjectType(Selector Sel, QualType Ty,
                                         bool IsInstance);

bool CheckARCMethodDecl(ObjCMethodDecl *method);
bool inferObjCARCLifetime(ValueDecl *decl);

void deduceOpenCLAddressSpace(ValueDecl *decl);

ExprResult
HandleExprPropertyRefExpr(const ObjCObjectPointerType *OPT,
                          Expr *BaseExpr,
                          SourceLocation OpLoc,
                          DeclarationName MemberName,
                          SourceLocation MemberLoc,
                          SourceLocation SuperLoc, QualType SuperType,
                          bool Super);

ExprResult
ActOnClassPropertyRefExpr(IdentifierInfo &receiverName,
                          IdentifierInfo &propertyName,
                          SourceLocation receiverNameLoc,
                          SourceLocation propertyNameLoc);

ObjCMethodDecl *tryCaptureObjCSelf(SourceLocation Loc);

/// Describes the kind of message expression indicated by a message
/// send that starts with an identifier.
enum ObjCMessageKind {
  /// The message is sent to 'super'.
  ObjCSuperMessage,
  /// The message is an instance message.
  ObjCInstanceMessage,
  /// The message is a class message, and the identifier is a type
  /// name.
  ObjCClassMessage
};

ObjCMessageKind getObjCMessageKind(Scope *S,
                                   IdentifierInfo *Name,
                                   SourceLocation NameLoc,
                                   bool IsSuper,
                                   bool HasTrailingDot,
                                   ParsedType &ReceiverType);

ExprResult ActOnSuperMessage(Scope *S, SourceLocation SuperLoc,
                             Selector Sel,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args);

ExprResult BuildClassMessage(TypeSourceInfo *ReceiverTypeInfo,
                             QualType ReceiverType,
                             SourceLocation SuperLoc,
                             Selector Sel,
                             ObjCMethodDecl *Method,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args,
                             bool isImplicit = false);

ExprResult BuildClassMessageImplicit(QualType ReceiverType,
                                     bool isSuperReceiver,
                                     SourceLocation Loc,
                                     Selector Sel,
                                     ObjCMethodDecl *Method,
                                     MultiExprArg Args);

ExprResult ActOnClassMessage(Scope *S,
                             ParsedType Receiver,
                             Selector Sel,
                             SourceLocation LBracLoc,
                             ArrayRef<SourceLocation> SelectorLocs,
                             SourceLocation RBracLoc,
                             MultiExprArg Args);

ExprResult BuildInstanceMessage(Expr *Receiver,
                                QualType ReceiverType,
                                SourceLocation SuperLoc,
                                Selector Sel,
                                ObjCMethodDecl *Method,
                                SourceLocation LBracLoc,
                                ArrayRef<SourceLocation> SelectorLocs,
                                SourceLocation RBracLoc,
                                MultiExprArg Args,
                                bool isImplicit = false);

ExprResult BuildInstanceMessageImplicit(Expr *Receiver,
                                        QualType ReceiverType,
                                        SourceLocation Loc,
                                        Selector Sel,
                                        ObjCMethodDecl *Method,
                                        MultiExprArg Args);

ExprResult ActOnInstanceMessage(Scope *S,
                                Expr *Receiver,
                                Selector Sel,
                                SourceLocation LBracLoc,
                                ArrayRef<SourceLocation> SelectorLocs,
                                SourceLocation RBracLoc,
                                MultiExprArg Args);

ExprResult BuildObjCBridgedCast(SourceLocation LParenLoc,
                                ObjCBridgeCastKind Kind,
                                SourceLocation BridgeKeywordLoc,
                                TypeSourceInfo *TSInfo,
                                Expr *SubExpr);

ExprResult ActOnObjCBridgedCast(Scope *S,
                                SourceLocation LParenLoc,
                                ObjCBridgeCastKind Kind,
                                SourceLocation BridgeKeywordLoc,
                                ParsedType Type,
                                SourceLocation RParenLoc,
                                Expr *SubExpr);

void CheckTollFreeBridgeCast(QualType castType, Expr *castExpr);

void CheckObjCBridgeRelatedCast(QualType castType, Expr *castExpr);

bool CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr,
                                   CastKind &Kind);

bool checkObjCBridgeRelatedComponents(SourceLocation Loc,
                                      QualType DestType, QualType SrcType,
                                      ObjCInterfaceDecl *&RelatedClass,
                                      ObjCMethodDecl *&ClassMethod,
                                      ObjCMethodDecl *&InstanceMethod,
                                      TypedefNameDecl *&TDNDecl,
                                      bool CfToNs, bool Diagnose = true);

bool CheckObjCBridgeRelatedConversions(SourceLocation Loc,
                                       QualType DestType, QualType SrcType,
                                       Expr *&SrcExpr, bool Diagnose = true);

bool CheckConversionToObjCLiteral(QualType DstType, Expr *&SrcExpr,
                                  bool Diagnose = true);

bool checkInitMethod(ObjCMethodDecl *method, QualType receiverTypeIfCall);

/// Check whether the given new method is a valid override of the
/// given overridden method, and set any properties that should be inherited.
void CheckObjCMethodOverride(ObjCMethodDecl *NewMethod,
                             const ObjCMethodDecl *Overridden);

/// Describes the compatibility of a result type with its method.
enum ResultTypeCompatibilityKind {
  RTC_Compatible,
  RTC_Incompatible,
  RTC_Unknown
};

void CheckObjCMethodDirectOverrides(ObjCMethodDecl *method,
                                    ObjCMethodDecl *overridden);

void CheckObjCMethodOverrides(ObjCMethodDecl *ObjCMethod,
                              ObjCInterfaceDecl *CurrentClass,
                              ResultTypeCompatibilityKind RTC);

enum PragmaOptionsAlignKind {
  POAK_Native,  // #pragma options align=native
  POAK_Natural, // #pragma options align=natural
  POAK_Packed,  // #pragma options align=packed
  POAK_Power,   // #pragma options align=power
  POAK_Mac68k,  // #pragma options align=mac68k
  POAK_Reset    // #pragma options align=reset
};

/// ActOnPragmaClangSection - Called on well formed \#pragma clang section
void ActOnPragmaClangSection(SourceLocation PragmaLoc,
                             PragmaClangSectionAction Action,
                             PragmaClangSectionKind SecKind, StringRef SecName);

/// ActOnPragmaOptionsAlign - Called on well formed \#pragma options align.
void ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
                             SourceLocation PragmaLoc);

/// ActOnPragmaPack - Called on well formed \#pragma pack(...).
void ActOnPragmaPack(SourceLocation PragmaLoc, PragmaMsStackAction Action,
                     StringRef SlotLabel, Expr *Alignment);

enum class PragmaAlignPackDiagnoseKind {
  NonDefaultStateAtInclude,
  ChangedStateAtExit
};

void DiagnoseNonDefaultPragmaAlignPack(PragmaAlignPackDiagnoseKind Kind,
                                       SourceLocation IncludeLoc);
void DiagnoseUnterminatedPragmaAlignPack();

/// ActOnPragmaMSStruct - Called on well formed \#pragma ms_struct [on|off].
void ActOnPragmaMSStruct(PragmaMSStructKind Kind);

/// ActOnPragmaMSComment - Called on well formed
/// \#pragma comment(kind, "arg").
void ActOnPragmaMSComment(SourceLocation CommentLoc, PragmaMSCommentKind Kind,
                          StringRef Arg);

/// ActOnPragmaMSPointersToMembers - called on well formed \#pragma
/// pointers_to_members(representation method[, general purpose
/// representation]).
void ActOnPragmaMSPointersToMembers(
    LangOptions::PragmaMSPointersToMembersKind Kind,
    SourceLocation PragmaLoc);

/// Called on well formed \#pragma vtordisp().
void ActOnPragmaMSVtorDisp(PragmaMsStackAction Action,
                           SourceLocation PragmaLoc,
                           MSVtorDispMode Value);

enum PragmaSectionKind {
  PSK_DataSeg,
  PSK_BSSSeg,
  PSK_ConstSeg,
  PSK_CodeSeg,
};

bool UnifySection(StringRef SectionName, int SectionFlags,
                  NamedDecl *TheDecl);
bool UnifySection(StringRef SectionName,
                  int SectionFlags,
                  SourceLocation PragmaSectionLocation);

/// Called on well formed \#pragma bss_seg/data_seg/const_seg/code_seg.
void ActOnPragmaMSSeg(SourceLocation PragmaLocation,
                      PragmaMsStackAction Action,
                      llvm::StringRef StackSlotLabel,
                      StringLiteral *SegmentName,
                      llvm::StringRef PragmaName);

/// Called on well formed \#pragma section().
void ActOnPragmaMSSection(SourceLocation PragmaLocation,
                          int SectionFlags, StringLiteral *SegmentName);

/// Called on well-formed \#pragma init_seg().
void ActOnPragmaMSInitSeg(SourceLocation PragmaLocation,
                          StringLiteral *SegmentName);

/// Called on #pragma clang __debug dump II
void ActOnPragmaDump(Scope *S, SourceLocation Loc, IdentifierInfo *II);

/// ActOnPragmaDetectMismatch - Call on well-formed \#pragma detect_mismatch
void ActOnPragmaDetectMismatch(SourceLocation Loc, StringRef Name,
                               StringRef Value);

/// Are precise floating point semantics currently enabled?
bool isPreciseFPEnabled() {
  return !CurFPFeatures.getAllowFPReassociate() &&
         !CurFPFeatures.getNoSignedZero() &&
         !CurFPFeatures.getAllowReciprocal() &&
         !CurFPFeatures.getAllowApproxFunc();
}

/// ActOnPragmaFloatControl - Call on well-formed \#pragma float_control
void ActOnPragmaFloatControl(SourceLocation Loc, PragmaMsStackAction Action,
                             PragmaFloatControlKind Value);

/// ActOnPragmaUnused - Called on well-formed '\#pragma unused'.
void ActOnPragmaUnused(const Token &Identifier,
                       Scope *curScope,
                       SourceLocation PragmaLoc);

/// ActOnPragmaVisibility - Called on well formed \#pragma GCC visibility... .
void ActOnPragmaVisibility(const IdentifierInfo* VisType,
                           SourceLocation PragmaLoc);

NamedDecl *DeclClonePragmaWeak(NamedDecl *ND, IdentifierInfo *II,
                               SourceLocation Loc);
void DeclApplyPragmaWeak(Scope *S, NamedDecl *ND, WeakInfo &W);

/// ActOnPragmaWeakID - Called on well formed \#pragma weak ident.
void ActOnPragmaWeakID(IdentifierInfo* WeakName,
                       SourceLocation PragmaLoc,
                       SourceLocation WeakNameLoc);

/// ActOnPragmaRedefineExtname - Called on well formed
/// \#pragma redefine_extname oldname newname.
void ActOnPragmaRedefineExtname(IdentifierInfo* WeakName,
                                IdentifierInfo* AliasName,
                                SourceLocation PragmaLoc,
                                SourceLocation WeakNameLoc,
                                SourceLocation AliasNameLoc);

/// ActOnPragmaWeakAlias - Called on well formed \#pragma weak ident = ident.
void ActOnPragmaWeakAlias(IdentifierInfo* WeakName,
                          IdentifierInfo* AliasName,
                          SourceLocation PragmaLoc,
                          SourceLocation WeakNameLoc,
                          SourceLocation AliasNameLoc);

/// ActOnPragmaFPContract - Called on well formed
/// \#pragma {STDC,OPENCL} FP_CONTRACT and
/// \#pragma clang fp contract
void ActOnPragmaFPContract(SourceLocation Loc, LangOptions::FPModeKind FPC);

/// Called on well formed
/// \#pragma clang fp reassociate
void ActOnPragmaFPReassociate(SourceLocation Loc, bool IsEnabled);

/// ActOnPragmaFenvAccess - Called on well formed
/// \#pragma STDC FENV_ACCESS
void ActOnPragmaFEnvAccess(SourceLocation Loc, bool IsEnabled);

/// Called on well formed '\#pragma clang fp' that has option 'exceptions'.
void ActOnPragmaFPExceptions(SourceLocation Loc,
                             LangOptions::FPExceptionModeKind);

/// Called to set constant rounding mode for floating point operations.
void setRoundingMode(SourceLocation Loc, llvm::RoundingMode);

/// Called to set exception behavior for floating point operations.
void setExceptionMode(SourceLocation Loc, LangOptions::FPExceptionModeKind);

/// AddAlignmentAttributesForRecord - Adds any needed alignment attributes to
/// a the record decl, to handle '\#pragma pack' and '\#pragma options align'.
void AddAlignmentAttributesForRecord(RecordDecl *RD);

/// AddMsStructLayoutForRecord - Adds ms_struct layout attribute to record.
void AddMsStructLayoutForRecord(RecordDecl *RD);

/// PushNamespaceVisibilityAttr - Note that we've entered a
/// namespace with a visibility attribute.
void PushNamespaceVisibilityAttr(const VisibilityAttr *Attr,
                                 SourceLocation Loc);

/// AddPushedVisibilityAttribute - If '\#pragma GCC visibility' was used,
/// add an appropriate visibility attribute.
void AddPushedVisibilityAttribute(Decl *RD);

/// PopPragmaVisibility - Pop the top element of the visibility stack; used
/// for '\#pragma GCC visibility' and visibility attributes on namespaces.
void PopPragmaVisibility(bool IsNamespaceEnd, SourceLocation EndLoc);

/// FreeVisContext - Deallocate and null out VisContext.
void FreeVisContext();

/// AddCFAuditedAttribute - Check whether we're currently within
/// '\#pragma clang arc_cf_code_audited' and, if so, consider adding
/// the appropriate attribute.
void AddCFAuditedAttribute(Decl *D);

void ActOnPragmaAttributeAttribute(ParsedAttr &Attribute,
                                   SourceLocation PragmaLoc,
                                   attr::ParsedSubjectMatchRuleSet Rules);
void ActOnPragmaAttributeEmptyPush(SourceLocation PragmaLoc,
                                   const IdentifierInfo *Namespace);

/// Called on well-formed '\#pragma clang attribute pop'.
void ActOnPragmaAttributePop(SourceLocation PragmaLoc,
                             const IdentifierInfo *Namespace);

/// Adds the attributes that have been specified using the
/// '\#pragma clang attribute push' directives to the given declaration.
void AddPragmaAttributes(Scope *S, Decl *D);

void DiagnoseUnterminatedPragmaAttribute();

/// Called on well formed \#pragma clang optimize.
void ActOnPragmaOptimize(bool On, SourceLocation PragmaLoc);

/// Get the location for the currently active "\#pragma clang optimize
/// off". If this location is invalid, then the state of the pragma is "on".
SourceLocation getOptimizeOffPragmaLocation() const {
  return OptimizeOffPragmaLocation;
}

/// Only called on function definitions; if there is a pragma in scope
/// with the effect of a range-based optnone, consider marking the function
/// with attribute optnone.
void AddRangeBasedOptnone(FunctionDecl *FD);

/// Adds the 'optnone' attribute to the function declaration if there
/// are no conflicts; Loc represents the location causing the 'optnone'
/// attribute to be added (usually because of a pragma).
void AddOptnoneAttributeIfNoConflicts(FunctionDecl *FD, SourceLocation Loc);

/// AddAlignedAttr - Adds an aligned attribute to a particular declaration.
void AddAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E,
                    bool IsPackExpansion);
void AddAlignedAttr(Decl *D, const AttributeCommonInfo &CI, TypeSourceInfo *T,
                    bool IsPackExpansion);

/// AddAssumeAlignedAttr - Adds an assume_aligned attribute to a particular
/// declaration.
void AddAssumeAlignedAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E,
                          Expr *OE);

/// AddAllocAlignAttr - Adds an alloc_align attribute to a particular
/// declaration.
void AddAllocAlignAttr(Decl *D, const AttributeCommonInfo &CI,
                       Expr *ParamExpr);

/// AddAlignValueAttr - Adds an align_value attribute to a particular
/// declaration.
void AddAlignValueAttr(Decl *D, const AttributeCommonInfo &CI, Expr *E);

/// AddAnnotationAttr - Adds an annotation Annot with Args arguments to D.
void AddAnnotationAttr(Decl *D, const AttributeCommonInfo &CI,
                       StringRef Annot, MutableArrayRef<Expr *> Args);

/// AddLaunchBoundsAttr - Adds a launch_bounds attribute to a particular
/// declaration.
void AddLaunchBoundsAttr(Decl *D, const AttributeCommonInfo &CI,
                         Expr *MaxThreads, Expr *MinBlocks);

/// AddModeAttr - Adds a mode attribute to a particular declaration.
void AddModeAttr(Decl *D, const AttributeCommonInfo &CI, IdentifierInfo *Name,
                 bool InInstantiation = false);

void AddParameterABIAttr(Decl *D, const AttributeCommonInfo &CI,
                         ParameterABI ABI);

enum class RetainOwnershipKind {NS, CF, OS};
void AddXConsumedAttr(Decl *D, const AttributeCommonInfo &CI,
                      RetainOwnershipKind K, bool IsTemplateInstantiation);

/// addAMDGPUFlatWorkGroupSizeAttr - Adds an amdgpu_flat_work_group_size
/// attribute to a particular declaration.
void addAMDGPUFlatWorkGroupSizeAttr(Decl *D, const AttributeCommonInfo &CI,
                                    Expr *Min, Expr *Max);

/// addAMDGPUWavePersEUAttr - Adds an amdgpu_waves_per_eu attribute to a
/// particular declaration.
void addAMDGPUWavesPerEUAttr(Decl *D, const AttributeCommonInfo &CI,
                             Expr *Min, Expr *Max);

bool checkNSReturnsRetainedReturnType(SourceLocation loc, QualType type);

//===--------------------------------------------------------------------===//
// C++ Coroutines TS
//
bool ActOnCoroutineBodyStart(Scope *S, SourceLocation KwLoc,
                             StringRef Keyword);
ExprResult ActOnCoawaitExpr(Scope *S, SourceLocation KwLoc, Expr *E);
ExprResult ActOnCoyieldExpr(Scope *S, SourceLocation KwLoc, Expr *E);
StmtResult ActOnCoreturnStmt(Scope *S, SourceLocation KwLoc, Expr *E);

ExprResult BuildResolvedCoawaitExpr(SourceLocation KwLoc, Expr *E,
                                    bool IsImplicit = false);
ExprResult BuildUnresolvedCoawaitExpr(SourceLocation KwLoc, Expr *E,
                                      UnresolvedLookupExpr* Lookup);
ExprResult BuildCoyieldExpr(SourceLocation KwLoc, Expr *E);
StmtResult BuildCoreturnStmt(SourceLocation KwLoc, Expr *E,
                             bool IsImplicit = false);
StmtResult BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs);
bool buildCoroutineParameterMoves(SourceLocation Loc);
VarDecl *buildCoroutinePromise(SourceLocation Loc);
void CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body);
ClassTemplateDecl *lookupCoroutineTraits(SourceLocation KwLoc,
                                         SourceLocation FuncLoc);
/// Check that the expression co_await promise.final_suspend() shall not be
/// potentially-throwing.
bool checkFinalSuspendNoThrow(const Stmt *FinalSuspend);

//===--------------------------------------------------------------------===//
// OpenMP directives and clauses.
//
10220private:
void *VarDataSharingAttributesStack;

struct DeclareTargetContextInfo {
  struct MapInfo {
    OMPDeclareTargetDeclAttr::MapTypeTy MT;
    SourceLocation Loc;
  };
  /// Explicitly listed variables and functions in a 'to' or 'link' clause.
  llvm::DenseMap<NamedDecl *, MapInfo> ExplicitlyMapped;

  /// The 'device_type' as parsed from the clause.
  OMPDeclareTargetDeclAttr::DevTypeTy DT = OMPDeclareTargetDeclAttr::DT_Any;

  /// The directive kind, `begin declare target` or `declare target`.
  OpenMPDirectiveKind Kind;

  /// The directive location.
  SourceLocation Loc;

  DeclareTargetContextInfo(OpenMPDirectiveKind Kind, SourceLocation Loc)
      : Kind(Kind), Loc(Loc) {}
};

/// Number of nested '#pragma omp declare target' directives.
SmallVector<DeclareTargetContextInfo, 4> DeclareTargetNesting;

/// Initialization of data-sharing attributes stack.
void InitDataSharingAttributesStack();
void DestroyDataSharingAttributesStack();
ExprResult
VerifyPositiveIntegerConstantInClause(Expr *Op, OpenMPClauseKind CKind,
                                      bool StrictlyPositive = true,
                                      bool SuppressExprDiags = false);
/// Returns OpenMP nesting level for current directive.
unsigned getOpenMPNestingLevel() const;

/// Adjusts the function scopes index for the target-based regions.
void adjustOpenMPTargetScopeIndex(unsigned &FunctionScopesIndex,
                                  unsigned Level) const;

/// Returns the number of scopes associated with the construct on the given
/// OpenMP level.
int getNumberOfConstructScopes(unsigned Level) const;

/// Push new OpenMP function region for non-capturing function.
void pushOpenMPFunctionRegion();

/// Pop OpenMP function region for non-capturing function.
void popOpenMPFunctionRegion(const sema::FunctionScopeInfo *OldFSI);

/// Analyzes and checks a loop nest for use by a loop transformation.
///
/// \param Kind          The loop transformation directive kind.
/// \param NumLoops      How many nested loops the directive is expecting.
/// \param AStmt         Associated statement of the transformation directive.
/// \param LoopHelpers   [out] The loop analysis result.
/// \param Body          [out] The body code nested in \p NumLoops loop.
/// \param OriginalInits [out] Collection of statements and declarations that
///                      must have been executed/declared before entering the
///                      loop.
///
/// \return Whether there was any error.
bool checkTransformableLoopNest(
    OpenMPDirectiveKind Kind, Stmt *AStmt, int NumLoops,
    SmallVectorImpl<OMPLoopBasedDirective::HelperExprs> &LoopHelpers,
    Stmt *&Body,
    SmallVectorImpl<SmallVector<llvm::PointerUnion<Stmt *, Decl *>, 0>>
        &OriginalInits);

/// Helper to keep information about the current `omp begin/end declare
/// variant` nesting.
struct OMPDeclareVariantScope {
  /// The associated OpenMP context selector.
  OMPTraitInfo *TI;

  /// The associated OpenMP context selector mangling.
  std::string NameSuffix;

  OMPDeclareVariantScope(OMPTraitInfo &TI);
};

/// Return the OMPTraitInfo for the surrounding scope, if any.
OMPTraitInfo *getOMPTraitInfoForSurroundingScope() {
  return OMPDeclareVariantScopes.empty() ? nullptr
                                         : OMPDeclareVariantScopes.back().TI;
}

/// The current `omp begin/end declare variant` scopes.
SmallVector<OMPDeclareVariantScope, 4> OMPDeclareVariantScopes;

/// The current `omp begin/end assumes` scopes.
SmallVector<AssumptionAttr *, 4> OMPAssumeScoped;

/// All `omp assumes` we encountered so far.
SmallVector<AssumptionAttr *, 4> OMPAssumeGlobal;

10317public:
/// The declarator \p D defines a function in the scope \p S which is nested
/// in an `omp begin/end declare variant` scope. In this method we create a
/// declaration for \p D and rename \p D according to the OpenMP context
/// selector of the surrounding scope. Return all base functions in \p Bases.
void ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope(
    Scope *S, Declarator &D, MultiTemplateParamsArg TemplateParameterLists,
    SmallVectorImpl<FunctionDecl *> &Bases);

/// Register \p D as specialization of all base functions in \p Bases in the
/// current `omp begin/end declare variant` scope.
void ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(
    Decl *D, SmallVectorImpl<FunctionDecl *> &Bases);

/// Act on \p D, a function definition inside of an `omp [begin/end] assumes`.
void ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(Decl *D);

/// Can we exit an OpenMP declare variant scope at the moment.
bool isInOpenMPDeclareVariantScope() const {
  return !OMPDeclareVariantScopes.empty();
}

/// Given the potential call expression \p Call, determine if there is a
/// specialization via the OpenMP declare variant mechanism available. If
/// there is, return the specialized call expression, otherwise return the
/// original \p Call.
ExprResult ActOnOpenMPCall(ExprResult Call, Scope *Scope,
                           SourceLocation LParenLoc, MultiExprArg ArgExprs,
                           SourceLocation RParenLoc, Expr *ExecConfig);

/// Handle a `omp begin declare variant`.
void ActOnOpenMPBeginDeclareVariant(SourceLocation Loc, OMPTraitInfo &TI);

/// Handle a `omp end declare variant`.
void ActOnOpenMPEndDeclareVariant();

/// Checks if the variant/multiversion functions are compatible.
bool areMultiversionVariantFunctionsCompatible(
    const FunctionDecl *OldFD, const FunctionDecl *NewFD,
    const PartialDiagnostic &NoProtoDiagID,
    const PartialDiagnosticAt &NoteCausedDiagIDAt,
    const PartialDiagnosticAt &NoSupportDiagIDAt,
    const PartialDiagnosticAt &DiffDiagIDAt, bool TemplatesSupported,
    bool ConstexprSupported, bool CLinkageMayDiffer);

/// Function tries to capture lambda's captured variables in the OpenMP region
/// before the original lambda is captured.
void tryCaptureOpenMPLambdas(ValueDecl *V);

/// Return true if the provided declaration \a VD should be captured by
/// reference.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
/// \param OpenMPCaptureLevel Capture level within an OpenMP construct.
bool isOpenMPCapturedByRef(const ValueDecl *D, unsigned Level,
                           unsigned OpenMPCaptureLevel) const;

/// Check if the specified variable is used in one of the private
/// clauses (private, firstprivate, lastprivate, reduction etc.) in OpenMP
/// constructs.
VarDecl *isOpenMPCapturedDecl(ValueDecl *D, bool CheckScopeInfo = false,
                              unsigned StopAt = 0);
ExprResult getOpenMPCapturedExpr(VarDecl *Capture, ExprValueKind VK,
                                 ExprObjectKind OK, SourceLocation Loc);

/// If the current region is a loop-based region, mark the start of the loop
/// construct.
void startOpenMPLoop();

/// If the current region is a range loop-based region, mark the start of the
/// loop construct.
void startOpenMPCXXRangeFor();

/// Check if the specified variable is used in 'private' clause.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
OpenMPClauseKind isOpenMPPrivateDecl(ValueDecl *D, unsigned Level,
                                     unsigned CapLevel) const;

/// Sets OpenMP capture kind (OMPC_private, OMPC_firstprivate, OMPC_map etc.)
/// for \p FD based on DSA for the provided corresponding captured declaration
/// \p D.
void setOpenMPCaptureKind(FieldDecl *FD, const ValueDecl *D, unsigned Level);

/// Check if the specified variable is captured  by 'target' directive.
/// \param Level Relative level of nested OpenMP construct for that the check
/// is performed.
bool isOpenMPTargetCapturedDecl(const ValueDecl *D, unsigned Level,
                                unsigned CaptureLevel) const;

/// Check if the specified global variable must be captured  by outer capture
/// regions.
/// \param Level Relative level of nested OpenMP construct for that
/// the check is performed.
bool isOpenMPGlobalCapturedDecl(ValueDecl *D, unsigned Level,
                                unsigned CaptureLevel) const;

ExprResult PerformOpenMPImplicitIntegerConversion(SourceLocation OpLoc,
                                                  Expr *Op);
/// Called on start of new data sharing attribute block.
void StartOpenMPDSABlock(OpenMPDirectiveKind K,
                         const DeclarationNameInfo &DirName, Scope *CurScope,
                         SourceLocation Loc);
/// Start analysis of clauses.
void StartOpenMPClause(OpenMPClauseKind K);
/// End analysis of clauses.
void EndOpenMPClause();
/// Called on end of data sharing attribute block.
void EndOpenMPDSABlock(Stmt *CurDirective);

/// Check if the current region is an OpenMP loop region and if it is,
/// mark loop control variable, used in \p Init for loop initialization, as
/// private by default.
/// \param Init First part of the for loop.
void ActOnOpenMPLoopInitialization(SourceLocation ForLoc, Stmt *Init);

// OpenMP directives and clauses.
/// Called on correct id-expression from the '#pragma omp
/// threadprivate'.
ExprResult ActOnOpenMPIdExpression(Scope *CurScope, CXXScopeSpec &ScopeSpec,
                                   const DeclarationNameInfo &Id,
                                   OpenMPDirectiveKind Kind);
/// Called on well-formed '#pragma omp threadprivate'.
DeclGroupPtrTy ActOnOpenMPThreadprivateDirective(
                                   SourceLocation Loc,
                                   ArrayRef<Expr *> VarList);
/// Builds a new OpenMPThreadPrivateDecl and checks its correctness.
OMPThreadPrivateDecl *CheckOMPThreadPrivateDecl(SourceLocation Loc,
                                                ArrayRef<Expr *> VarList);
/// Called on well-formed '#pragma omp allocate'.
DeclGroupPtrTy ActOnOpenMPAllocateDirective(SourceLocation Loc,
                                            ArrayRef<Expr *> VarList,
                                            ArrayRef<OMPClause *> Clauses,
                                            DeclContext *Owner = nullptr);

/// Called on well-formed '#pragma omp [begin] assume[s]'.
void ActOnOpenMPAssumesDirective(SourceLocation Loc,
                                 OpenMPDirectiveKind DKind,
                                 ArrayRef<StringRef> Assumptions,
                                 bool SkippedClauses);

/// Check if there is an active global `omp begin assumes` directive.
bool isInOpenMPAssumeScope() const { return !OMPAssumeScoped.empty(); }

/// Check if there is an active global `omp assumes` directive.
bool hasGlobalOpenMPAssumes() const { return !OMPAssumeGlobal.empty(); }

/// Called on well-formed '#pragma omp end assumes'.
void ActOnOpenMPEndAssumesDirective();

/// Called on well-formed '#pragma omp requires'.
DeclGroupPtrTy ActOnOpenMPRequiresDirective(SourceLocation Loc,
                                            ArrayRef<OMPClause *> ClauseList);
/// Check restrictions on Requires directive
OMPRequiresDecl *CheckOMPRequiresDecl(SourceLocation Loc,
                                      ArrayRef<OMPClause *> Clauses);
/// Check if the specified type is allowed to be used in 'omp declare
/// reduction' construct.
QualType ActOnOpenMPDeclareReductionType(SourceLocation TyLoc,
                                         TypeResult ParsedType);
/// Called on start of '#pragma omp declare reduction'.
DeclGroupPtrTy ActOnOpenMPDeclareReductionDirectiveStart(
    Scope *S, DeclContext *DC, DeclarationName Name,
    ArrayRef<std::pair<QualType, SourceLocation>> ReductionTypes,
    AccessSpecifier AS, Decl *PrevDeclInScope = nullptr);
/// Initialize declare reduction construct initializer.
void ActOnOpenMPDeclareReductionCombinerStart(Scope *S, Decl *D);
/// Finish current declare reduction construct initializer.
void ActOnOpenMPDeclareReductionCombinerEnd(Decl *D, Expr *Combiner);
/// Initialize declare reduction construct initializer.
/// \return omp_priv variable.
VarDecl *ActOnOpenMPDeclareReductionInitializerStart(Scope *S, Decl *D);
/// Finish current declare reduction construct initializer.
void ActOnOpenMPDeclareReductionInitializerEnd(Decl *D, Expr *Initializer,
                                               VarDecl *OmpPrivParm);
/// Called at the end of '#pragma omp declare reduction'.
DeclGroupPtrTy ActOnOpenMPDeclareReductionDirectiveEnd(
    Scope *S, DeclGroupPtrTy DeclReductions, bool IsValid);

/// Check variable declaration in 'omp declare mapper' construct.
TypeResult ActOnOpenMPDeclareMapperVarDecl(Scope *S, Declarator &D);
/// Check if the specified type is allowed to be used in 'omp declare
/// mapper' construct.
QualType ActOnOpenMPDeclareMapperType(SourceLocation TyLoc,
                                      TypeResult ParsedType);
/// Called on start of '#pragma omp declare mapper'.
DeclGroupPtrTy ActOnOpenMPDeclareMapperDirective(
    Scope *S, DeclContext *DC, DeclarationName Name, QualType MapperType,
    SourceLocation StartLoc, DeclarationName VN, AccessSpecifier AS,
    Expr *MapperVarRef, ArrayRef<OMPClause *> Clauses,
    Decl *PrevDeclInScope = nullptr);
/// Build the mapper variable of '#pragma omp declare mapper'.
ExprResult ActOnOpenMPDeclareMapperDirectiveVarDecl(Scope *S,
                                                    QualType MapperType,
                                                    SourceLocation StartLoc,
                                                    DeclarationName VN);
bool isOpenMPDeclareMapperVarDeclAllowed(const VarDecl *VD) const;
const ValueDecl *getOpenMPDeclareMapperVarName() const;

/// Called on the start of target region i.e. '#pragma omp declare target'.
bool ActOnStartOpenMPDeclareTargetContext(DeclareTargetContextInfo &DTCI);

/// Called at the end of target region i.e. '#pragma omp end declare target'.
const DeclareTargetContextInfo ActOnOpenMPEndDeclareTargetDirective();

/// Called once a target context is completed, that can be when a
/// '#pragma omp end declare target' was encountered or when a
/// '#pragma omp declare target' without declaration-definition-seq was
/// encountered.
void ActOnFinishedOpenMPDeclareTargetContext(DeclareTargetContextInfo &DTCI);

/// Searches for the provided declaration name for OpenMP declare target
/// directive.
NamedDecl *lookupOpenMPDeclareTargetName(Scope *CurScope,
                                         CXXScopeSpec &ScopeSpec,
                                         const DeclarationNameInfo &Id);

/// Called on correct id-expression from the '#pragma omp declare target'.
void ActOnOpenMPDeclareTargetName(NamedDecl *ND, SourceLocation Loc,
                                  OMPDeclareTargetDeclAttr::MapTypeTy MT,
                                  OMPDeclareTargetDeclAttr::DevTypeTy DT);

/// Check declaration inside target region.
void
checkDeclIsAllowedInOpenMPTarget(Expr *E, Decl *D,
                                 SourceLocation IdLoc = SourceLocation());
/// Finishes analysis of the deferred functions calls that may be declared as
/// host/nohost during device/host compilation.
void finalizeOpenMPDelayedAnalysis(const FunctionDecl *Caller,
                                   const FunctionDecl *Callee,
                                   SourceLocation Loc);
/// Return true inside OpenMP declare target region.
bool isInOpenMPDeclareTargetContext() const {
  return !DeclareTargetNesting.empty();
}
/// Return true inside OpenMP target region.
bool isInOpenMPTargetExecutionDirective() const;

/// Return the number of captured regions created for an OpenMP directive.
static int getOpenMPCaptureLevels(OpenMPDirectiveKind Kind);

/// Initialization of captured region for OpenMP region.
void ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope);

/// Called for syntactical loops (ForStmt or CXXForRangeStmt) associated to
/// an OpenMP loop directive.
StmtResult ActOnOpenMPCanonicalLoop(Stmt *AStmt);

/// End of OpenMP region.
///
/// \param S Statement associated with the current OpenMP region.
/// \param Clauses List of clauses for the current OpenMP region.
///
/// \returns Statement for finished OpenMP region.
StmtResult ActOnOpenMPRegionEnd(StmtResult S, ArrayRef<OMPClause *> Clauses);
StmtResult ActOnOpenMPExecutableDirective(
    OpenMPDirectiveKind Kind, const DeclarationNameInfo &DirName,
    OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
    Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel' after parsing
/// of the  associated statement.
StmtResult ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt,
                                        SourceLocation StartLoc,
                                        SourceLocation EndLoc);
using VarsWithInheritedDSAType =
    llvm::SmallDenseMap<const ValueDecl *, const Expr *, 4>;
/// Called on well-formed '\#pragma omp simd' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                         SourceLocation StartLoc, SourceLocation EndLoc,
                         VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '#pragma omp tile' after parsing of its clauses and
/// the associated statement.
StmtResult ActOnOpenMPTileDirective(ArrayRef<OMPClause *> Clauses,
                                    Stmt *AStmt, SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '#pragma omp unroll' after parsing of its clauses
/// and the associated statement.
StmtResult ActOnOpenMPUnrollDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp for' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPForDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                        SourceLocation StartLoc, SourceLocation EndLoc,
                        VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp for simd' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPForSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                            SourceLocation StartLoc, SourceLocation EndLoc,
                            VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp sections' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPSectionsDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp section' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPSectionDirective(Stmt *AStmt, SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp single' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPSingleDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp master' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPMasterDirective(Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp critical' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPCriticalDirective(const DeclarationNameInfo &DirName,
                                        ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel for' after parsing
/// of the  associated statement.
StmtResult ActOnOpenMPParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel for simd' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelMasterDirective(ArrayRef<OMPClause *> Clauses,
                                              Stmt *AStmt,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp parallel sections' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPParallelSectionsDirective(ArrayRef<OMPClause *> Clauses,
                                                Stmt *AStmt,
                                                SourceLocation StartLoc,
                                                SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp task' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTaskDirective(ArrayRef<OMPClause *> Clauses,
                                    Stmt *AStmt, SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskyield'.
StmtResult ActOnOpenMPTaskyieldDirective(SourceLocation StartLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp barrier'.
StmtResult ActOnOpenMPBarrierDirective(SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskwait'.
StmtResult ActOnOpenMPTaskwaitDirective(SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp taskgroup'.
StmtResult ActOnOpenMPTaskgroupDirective(ArrayRef<OMPClause *> Clauses,
                                         Stmt *AStmt, SourceLocation StartLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp flush'.
StmtResult ActOnOpenMPFlushDirective(ArrayRef<OMPClause *> Clauses,
                                     SourceLocation StartLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp depobj'.
StmtResult ActOnOpenMPDepobjDirective(ArrayRef<OMPClause *> Clauses,
                                      SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp scan'.
StmtResult ActOnOpenMPScanDirective(ArrayRef<OMPClause *> Clauses,
                                    SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp ordered' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPOrderedDirective(ArrayRef<OMPClause *> Clauses,
                                       Stmt *AStmt, SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp atomic' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPAtomicDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTargetDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target data' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTargetDataDirective(ArrayRef<OMPClause *> Clauses,
                                          Stmt *AStmt, SourceLocation StartLoc,
                                          SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target enter data' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetEnterDataDirective(ArrayRef<OMPClause *> Clauses,
                                               SourceLocation StartLoc,
                                               SourceLocation EndLoc,
                                               Stmt *AStmt);
/// Called on well-formed '\#pragma omp target exit data' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetExitDataDirective(ArrayRef<OMPClause *> Clauses,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc,
                                              Stmt *AStmt);
/// Called on well-formed '\#pragma omp target parallel' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetParallelDirective(ArrayRef<OMPClause *> Clauses,
                                              Stmt *AStmt,
                                              SourceLocation StartLoc,
                                              SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target parallel for' after
/// parsing of the  associated statement.
StmtResult ActOnOpenMPTargetParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTeamsDirective(ArrayRef<OMPClause *> Clauses,
                                     Stmt *AStmt, SourceLocation StartLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp cancellation point'.
StmtResult
ActOnOpenMPCancellationPointDirective(SourceLocation StartLoc,
                                      SourceLocation EndLoc,
                                      OpenMPDirectiveKind CancelRegion);
/// Called on well-formed '\#pragma omp cancel'.
StmtResult ActOnOpenMPCancelDirective(ArrayRef<OMPClause *> Clauses,
                                      SourceLocation StartLoc,
                                      SourceLocation EndLoc,
                                      OpenMPDirectiveKind CancelRegion);
/// Called on well-formed '\#pragma omp taskloop' after parsing of the
/// associated statement.
StmtResult
ActOnOpenMPTaskLoopDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                             SourceLocation StartLoc, SourceLocation EndLoc,
                             VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp taskloop simd' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp master taskloop' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPMasterTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp master taskloop simd' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPMasterTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master taskloop' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMasterTaskLoopDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp parallel master taskloop simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPParallelMasterTaskLoopSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute' after parsing
/// of the associated statement.
StmtResult
ActOnOpenMPDistributeDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                               SourceLocation StartLoc, SourceLocation EndLoc,
                               VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target update'.
StmtResult ActOnOpenMPTargetUpdateDirective(ArrayRef<OMPClause *> Clauses,
                                            SourceLocation StartLoc,
                                            SourceLocation EndLoc,
                                            Stmt *AStmt);
/// Called on well-formed '\#pragma omp distribute parallel for' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute parallel for simd'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp distribute simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target parallel for simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target simd' after parsing of
/// the associated statement.
StmtResult
ActOnOpenMPTargetSimdDirective(ArrayRef<OMPClause *> Clauses, Stmt *AStmt,
                               SourceLocation StartLoc, SourceLocation EndLoc,
                               VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute' after parsing of
/// the associated statement.
StmtResult ActOnOpenMPTeamsDistributeDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute simd' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute parallel for simd'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp teams distribute parallel for'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTeamsDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams' after parsing of the
/// associated statement.
StmtResult ActOnOpenMPTargetTeamsDirective(ArrayRef<OMPClause *> Clauses,
                                           Stmt *AStmt,
                                           SourceLocation StartLoc,
                                           SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp target teams distribute' after parsing
/// of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute parallel for'
/// after parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeParallelForDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute parallel for
/// simd' after parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeParallelForSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp target teams distribute simd' after
/// parsing of the associated statement.
StmtResult ActOnOpenMPTargetTeamsDistributeSimdDirective(
    ArrayRef<OMPClause *> Clauses, Stmt *AStmt, SourceLocation StartLoc,
    SourceLocation EndLoc, VarsWithInheritedDSAType &VarsWithImplicitDSA);
/// Called on well-formed '\#pragma omp interop'.
StmtResult ActOnOpenMPInteropDirective(ArrayRef<OMPClause *> Clauses,
                                       SourceLocation StartLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp dispatch' after parsing of the
// /associated statement.
StmtResult ActOnOpenMPDispatchDirective(ArrayRef<OMPClause *> Clauses,
                                        Stmt *AStmt, SourceLocation StartLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed '\#pragma omp masked' after parsing of the
// /associated statement.
StmtResult ActOnOpenMPMaskedDirective(ArrayRef<OMPClause *> Clauses,
                                      Stmt *AStmt, SourceLocation StartLoc,
                                      SourceLocation EndLoc);

/// Checks correctness of linear modifiers.
bool CheckOpenMPLinearModifier(OpenMPLinearClauseKind LinKind,
                               SourceLocation LinLoc);
/// Checks that the specified declaration matches requirements for the linear
/// decls.
bool CheckOpenMPLinearDecl(const ValueDecl *D, SourceLocation ELoc,
                           OpenMPLinearClauseKind LinKind, QualType Type,
                           bool IsDeclareSimd = false);

/// Called on well-formed '\#pragma omp declare simd' after parsing of
/// the associated method/function.
DeclGroupPtrTy ActOnOpenMPDeclareSimdDirective(
    DeclGroupPtrTy DG, OMPDeclareSimdDeclAttr::BranchStateTy BS,
    Expr *Simdlen, ArrayRef<Expr *> Uniforms, ArrayRef<Expr *> Aligneds,
    ArrayRef<Expr *> Alignments, ArrayRef<Expr *> Linears,
    ArrayRef<unsigned> LinModifiers, ArrayRef<Expr *> Steps, SourceRange SR);

/// Checks '\#pragma omp declare variant' variant function and original
/// functions after parsing of the associated method/function.
/// \param DG Function declaration to which declare variant directive is
/// applied to.
/// \param VariantRef Expression that references the variant function, which
/// must be used instead of the original one, specified in \p DG.
/// \param TI The trait info object representing the match clause.
/// \returns None, if the function/variant function are not compatible with
/// the pragma, pair of original function/variant ref expression otherwise.
Optional<std::pair<FunctionDecl *, Expr *>>
checkOpenMPDeclareVariantFunction(DeclGroupPtrTy DG, Expr *VariantRef,
                                  OMPTraitInfo &TI, SourceRange SR);

/// Called on well-formed '\#pragma omp declare variant' after parsing of
/// the associated method/function.
/// \param FD Function declaration to which declare variant directive is
/// applied to.
/// \param VariantRef Expression that references the variant function, which
/// must be used instead of the original one, specified in \p DG.
/// \param TI The context traits associated with the function variant.
void ActOnOpenMPDeclareVariantDirective(FunctionDecl *FD, Expr *VariantRef,
                                        OMPTraitInfo &TI, SourceRange SR);

OMPClause *ActOnOpenMPSingleExprClause(OpenMPClauseKind Kind,
                                       Expr *Expr,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'allocator' clause.
OMPClause *ActOnOpenMPAllocatorClause(Expr *Allocator,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'if' clause.
OMPClause *ActOnOpenMPIfClause(OpenMPDirectiveKind NameModifier,
                               Expr *Condition, SourceLocation StartLoc,
                               SourceLocation LParenLoc,
                               SourceLocation NameModifierLoc,
                               SourceLocation ColonLoc,
                               SourceLocation EndLoc);
/// Called on well-formed 'final' clause.
OMPClause *ActOnOpenMPFinalClause(Expr *Condition, SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'num_threads' clause.
OMPClause *ActOnOpenMPNumThreadsClause(Expr *NumThreads,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'safelen' clause.
OMPClause *ActOnOpenMPSafelenClause(Expr *Length,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'simdlen' clause.
OMPClause *ActOnOpenMPSimdlenClause(Expr *Length, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-form 'sizes' clause.
OMPClause *ActOnOpenMPSizesClause(ArrayRef<Expr *> SizeExprs,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-form 'full' clauses.
OMPClause *ActOnOpenMPFullClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-form 'partial' clauses.
OMPClause *ActOnOpenMPPartialClause(Expr *FactorExpr, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'collapse' clause.
OMPClause *ActOnOpenMPCollapseClause(Expr *NumForLoops,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'ordered' clause.
OMPClause *
ActOnOpenMPOrderedClause(SourceLocation StartLoc, SourceLocation EndLoc,
                         SourceLocation LParenLoc = SourceLocation(),
                         Expr *NumForLoops = nullptr);
/// Called on well-formed 'grainsize' clause.
OMPClause *ActOnOpenMPGrainsizeClause(Expr *Size, SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'num_tasks' clause.
OMPClause *ActOnOpenMPNumTasksClause(Expr *NumTasks, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'hint' clause.
OMPClause *ActOnOpenMPHintClause(Expr *Hint, SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'detach' clause.
OMPClause *ActOnOpenMPDetachClause(Expr *Evt, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);

OMPClause *ActOnOpenMPSimpleClause(OpenMPClauseKind Kind,
                                   unsigned Argument,
                                   SourceLocation ArgumentLoc,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'default' clause.
OMPClause *ActOnOpenMPDefaultClause(llvm::omp::DefaultKind Kind,
                                    SourceLocation KindLoc,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'proc_bind' clause.
OMPClause *ActOnOpenMPProcBindClause(llvm::omp::ProcBindKind Kind,
                                     SourceLocation KindLoc,
                                     SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'order' clause.
OMPClause *ActOnOpenMPOrderClause(OpenMPOrderClauseKind Kind,
                                  SourceLocation KindLoc,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'update' clause.
OMPClause *ActOnOpenMPUpdateClause(OpenMPDependClauseKind Kind,
                                   SourceLocation KindLoc,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);

OMPClause *ActOnOpenMPSingleExprWithArgClause(
    OpenMPClauseKind Kind, ArrayRef<unsigned> Arguments, Expr *Expr,
    SourceLocation StartLoc, SourceLocation LParenLoc,
    ArrayRef<SourceLocation> ArgumentsLoc, SourceLocation DelimLoc,
    SourceLocation EndLoc);
/// Called on well-formed 'schedule' clause.
OMPClause *ActOnOpenMPScheduleClause(
    OpenMPScheduleClauseModifier M1, OpenMPScheduleClauseModifier M2,
    OpenMPScheduleClauseKind Kind, Expr *ChunkSize, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation M1Loc, SourceLocation M2Loc,
    SourceLocation KindLoc, SourceLocation CommaLoc, SourceLocation EndLoc);

OMPClause *ActOnOpenMPClause(OpenMPClauseKind Kind, SourceLocation StartLoc,
                             SourceLocation EndLoc);
/// Called on well-formed 'nowait' clause.
OMPClause *ActOnOpenMPNowaitClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'untied' clause.
OMPClause *ActOnOpenMPUntiedClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'mergeable' clause.
OMPClause *ActOnOpenMPMergeableClause(SourceLocation StartLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'read' clause.
OMPClause *ActOnOpenMPReadClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'write' clause.
OMPClause *ActOnOpenMPWriteClause(SourceLocation StartLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'update' clause.
OMPClause *ActOnOpenMPUpdateClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'capture' clause.
OMPClause *ActOnOpenMPCaptureClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'seq_cst' clause.
OMPClause *ActOnOpenMPSeqCstClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'acq_rel' clause.
OMPClause *ActOnOpenMPAcqRelClause(SourceLocation StartLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'acquire' clause.
OMPClause *ActOnOpenMPAcquireClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'release' clause.
OMPClause *ActOnOpenMPReleaseClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'relaxed' clause.
OMPClause *ActOnOpenMPRelaxedClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);

/// Called on well-formed 'init' clause.
OMPClause *ActOnOpenMPInitClause(Expr *InteropVar, ArrayRef<Expr *> PrefExprs,
                                 bool IsTarget, bool IsTargetSync,
                                 SourceLocation StartLoc,
                                 SourceLocation LParenLoc,
                                 SourceLocation VarLoc,
                                 SourceLocation EndLoc);

/// Called on well-formed 'use' clause.
OMPClause *ActOnOpenMPUseClause(Expr *InteropVar, SourceLocation StartLoc,
                                SourceLocation LParenLoc,
                                SourceLocation VarLoc, SourceLocation EndLoc);

/// Called on well-formed 'destroy' clause.
OMPClause *ActOnOpenMPDestroyClause(Expr *InteropVar, SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation VarLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'novariants' clause.
OMPClause *ActOnOpenMPNovariantsClause(Expr *Condition,
                                       SourceLocation StartLoc,
                                       SourceLocation LParenLoc,
                                       SourceLocation EndLoc);
/// Called on well-formed 'nocontext' clause.
OMPClause *ActOnOpenMPNocontextClause(Expr *Condition,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'filter' clause.
OMPClause *ActOnOpenMPFilterClause(Expr *ThreadID, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'threads' clause.
OMPClause *ActOnOpenMPThreadsClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'simd' clause.
OMPClause *ActOnOpenMPSIMDClause(SourceLocation StartLoc,
                                 SourceLocation EndLoc);
/// Called on well-formed 'nogroup' clause.
OMPClause *ActOnOpenMPNogroupClause(SourceLocation StartLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'unified_address' clause.
OMPClause *ActOnOpenMPUnifiedAddressClause(SourceLocation StartLoc,
                                           SourceLocation EndLoc);

/// Called on well-formed 'unified_address' clause.
OMPClause *ActOnOpenMPUnifiedSharedMemoryClause(SourceLocation StartLoc,
                                                SourceLocation EndLoc);

/// Called on well-formed 'reverse_offload' clause.
OMPClause *ActOnOpenMPReverseOffloadClause(SourceLocation StartLoc,
                                           SourceLocation EndLoc);

/// Called on well-formed 'dynamic_allocators' clause.
OMPClause *ActOnOpenMPDynamicAllocatorsClause(SourceLocation StartLoc,
                                              SourceLocation EndLoc);

/// Called on well-formed 'atomic_default_mem_order' clause.
OMPClause *ActOnOpenMPAtomicDefaultMemOrderClause(
    OpenMPAtomicDefaultMemOrderClauseKind Kind, SourceLocation KindLoc,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc);

OMPClause *ActOnOpenMPVarListClause(
    OpenMPClauseKind Kind, ArrayRef<Expr *> Vars, Expr *DepModOrTailExpr,
    const OMPVarListLocTy &Locs, SourceLocation ColonLoc,
    CXXScopeSpec &ReductionOrMapperIdScopeSpec,
    DeclarationNameInfo &ReductionOrMapperId, int ExtraModifier,
    ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
    ArrayRef<SourceLocation> MapTypeModifiersLoc, bool IsMapTypeImplicit,
    SourceLocation ExtraModifierLoc,
    ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
    ArrayRef<SourceLocation> MotionModifiersLoc);
/// Called on well-formed 'inclusive' clause.
OMPClause *ActOnOpenMPInclusiveClause(ArrayRef<Expr *> VarList,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'exclusive' clause.
OMPClause *ActOnOpenMPExclusiveClause(ArrayRef<Expr *> VarList,
                                      SourceLocation StartLoc,
                                      SourceLocation LParenLoc,
                                      SourceLocation EndLoc);
/// Called on well-formed 'allocate' clause.
OMPClause *
ActOnOpenMPAllocateClause(Expr *Allocator, ArrayRef<Expr *> VarList,
                          SourceLocation StartLoc, SourceLocation ColonLoc,
                          SourceLocation LParenLoc, SourceLocation EndLoc);
/// Called on well-formed 'private' clause.
OMPClause *ActOnOpenMPPrivateClause(ArrayRef<Expr *> VarList,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'firstprivate' clause.
OMPClause *ActOnOpenMPFirstprivateClause(ArrayRef<Expr *> VarList,
                                         SourceLocation StartLoc,
                                         SourceLocation LParenLoc,
                                         SourceLocation EndLoc);
/// Called on well-formed 'lastprivate' clause.
OMPClause *ActOnOpenMPLastprivateClause(
    ArrayRef<Expr *> VarList, OpenMPLastprivateModifier LPKind,
    SourceLocation LPKindLoc, SourceLocation ColonLoc,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation EndLoc);
/// Called on well-formed 'shared' clause.
OMPClause *ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'reduction' clause.
OMPClause *ActOnOpenMPReductionClause(
    ArrayRef<Expr *> VarList, OpenMPReductionClauseModifier Modifier,
    SourceLocation StartLoc, SourceLocation LParenLoc,
    SourceLocation ModifierLoc, SourceLocation ColonLoc,
    SourceLocation EndLoc, CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = llvm::None);
/// Called on well-formed 'task_reduction' clause.
OMPClause *ActOnOpenMPTaskReductionClause(
    ArrayRef<Expr *> VarList, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc,
    CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = llvm::None);
/// Called on well-formed 'in_reduction' clause.
OMPClause *ActOnOpenMPInReductionClause(
    ArrayRef<Expr *> VarList, SourceLocation StartLoc,
    SourceLocation LParenLoc, SourceLocation ColonLoc, SourceLocation EndLoc,
    CXXScopeSpec &ReductionIdScopeSpec,
    const DeclarationNameInfo &ReductionId,
    ArrayRef<Expr *> UnresolvedReductions = llvm::None);
/// Called on well-formed 'linear' clause.
OMPClause *
ActOnOpenMPLinearClause(ArrayRef<Expr *> VarList, Expr *Step,
                        SourceLocation StartLoc, SourceLocation LParenLoc,
                        OpenMPLinearClauseKind LinKind, SourceLocation LinLoc,
                        SourceLocation ColonLoc, SourceLocation EndLoc);
/// Called on well-formed 'aligned' clause.
OMPClause *ActOnOpenMPAlignedClause(ArrayRef<Expr *> VarList,
                                    Expr *Alignment,
                                    SourceLocation StartLoc,
                                    SourceLocation LParenLoc,
                                    SourceLocation ColonLoc,
                                    SourceLocation EndLoc);
/// Called on well-formed 'copyin' clause.
OMPClause *ActOnOpenMPCopyinClause(ArrayRef<Expr *> VarList,
                                   SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'copyprivate' clause.
OMPClause *ActOnOpenMPCopyprivateClause(ArrayRef<Expr *> VarList,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed 'flush' pseudo clause.
OMPClause *ActOnOpenMPFlushClause(ArrayRef<Expr *> VarList,
                                  SourceLocation StartLoc,
                                  SourceLocation LParenLoc,
                                  SourceLocation EndLoc);
/// Called on well-formed 'depobj' pseudo clause.
OMPClause *ActOnOpenMPDepobjClause(Expr *Depobj, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'depend' clause.
OMPClause *
ActOnOpenMPDependClause(Expr *DepModifier, OpenMPDependClauseKind DepKind,
                        SourceLocation DepLoc, SourceLocation ColonLoc,
                        ArrayRef<Expr *> VarList, SourceLocation StartLoc,
                        SourceLocation LParenLoc, SourceLocation EndLoc);
/// Called on well-formed 'device' clause.
OMPClause *ActOnOpenMPDeviceClause(OpenMPDeviceClauseModifier Modifier,
                                   Expr *Device, SourceLocation StartLoc,
                                   SourceLocation LParenLoc,
                                   SourceLocation ModifierLoc,
                                   SourceLocation EndLoc);
/// Called on well-formed 'map' clause.
OMPClause *
ActOnOpenMPMapClause(ArrayRef<OpenMPMapModifierKind> MapTypeModifiers,
                     ArrayRef<SourceLocation> MapTypeModifiersLoc,
                     CXXScopeSpec &MapperIdScopeSpec,
                     DeclarationNameInfo &MapperId,
                     OpenMPMapClauseKind MapType, bool IsMapTypeImplicit,
                     SourceLocation MapLoc, SourceLocation ColonLoc,
                     ArrayRef<Expr *> VarList, const OMPVarListLocTy &Locs,
                     ArrayRef<Expr *> UnresolvedMappers = llvm::None);
/// Called on well-formed 'num_teams' clause.
OMPClause *ActOnOpenMPNumTeamsClause(Expr *NumTeams, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'thread_limit' clause.
OMPClause *ActOnOpenMPThreadLimitClause(Expr *ThreadLimit,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);
/// Called on well-formed 'priority' clause.
OMPClause *ActOnOpenMPPriorityClause(Expr *Priority, SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation EndLoc);
/// Called on well-formed 'dist_schedule' clause.
OMPClause *ActOnOpenMPDistScheduleClause(
    OpenMPDistScheduleClauseKind Kind, Expr *ChunkSize,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation KindLoc,
    SourceLocation CommaLoc, SourceLocation EndLoc);
/// Called on well-formed 'defaultmap' clause.
OMPClause *ActOnOpenMPDefaultmapClause(
    OpenMPDefaultmapClauseModifier M, OpenMPDefaultmapClauseKind Kind,
    SourceLocation StartLoc, SourceLocation LParenLoc, SourceLocation MLoc,
    SourceLocation KindLoc, SourceLocation EndLoc);
/// Called on well-formed 'to' clause.
OMPClause *
ActOnOpenMPToClause(ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
                    ArrayRef<SourceLocation> MotionModifiersLoc,
                    CXXScopeSpec &MapperIdScopeSpec,
                    DeclarationNameInfo &MapperId, SourceLocation ColonLoc,
                    ArrayRef<Expr *> VarList, const OMPVarListLocTy &Locs,
                    ArrayRef<Expr *> UnresolvedMappers = llvm::None);
/// Called on well-formed 'from' clause.
OMPClause *
ActOnOpenMPFromClause(ArrayRef<OpenMPMotionModifierKind> MotionModifiers,
                      ArrayRef<SourceLocation> MotionModifiersLoc,
                      CXXScopeSpec &MapperIdScopeSpec,
                      DeclarationNameInfo &MapperId, SourceLocation ColonLoc,
                      ArrayRef<Expr *> VarList, const OMPVarListLocTy &Locs,
                      ArrayRef<Expr *> UnresolvedMappers = llvm::None);
/// Called on well-formed 'use_device_ptr' clause.
OMPClause *ActOnOpenMPUseDevicePtrClause(ArrayRef<Expr *> VarList,
                                         const OMPVarListLocTy &Locs);
/// Called on well-formed 'use_device_addr' clause.
OMPClause *ActOnOpenMPUseDeviceAddrClause(ArrayRef<Expr *> VarList,
                                          const OMPVarListLocTy &Locs);
/// Called on well-formed 'is_device_ptr' clause.
OMPClause *ActOnOpenMPIsDevicePtrClause(ArrayRef<Expr *> VarList,
                                        const OMPVarListLocTy &Locs);
/// Called on well-formed 'nontemporal' clause.
OMPClause *ActOnOpenMPNontemporalClause(ArrayRef<Expr *> VarList,
                                        SourceLocation StartLoc,
                                        SourceLocation LParenLoc,
                                        SourceLocation EndLoc);

/// Data for list of allocators.
struct UsesAllocatorsData {
  /// Allocator.
  Expr *Allocator = nullptr;
  /// Allocator traits.
  Expr *AllocatorTraits = nullptr;
  /// Locations of '(' and ')' symbols.
  SourceLocation LParenLoc, RParenLoc;
};
/// Called on well-formed 'uses_allocators' clause.
OMPClause *ActOnOpenMPUsesAllocatorClause(SourceLocation StartLoc,
                                          SourceLocation LParenLoc,
                                          SourceLocation EndLoc,
                                          ArrayRef<UsesAllocatorsData> Data);
/// Called on well-formed 'affinity' clause.
OMPClause *ActOnOpenMPAffinityClause(SourceLocation StartLoc,
                                     SourceLocation LParenLoc,
                                     SourceLocation ColonLoc,
                                     SourceLocation EndLoc, Expr *Modifier,
                                     ArrayRef<Expr *> Locators);

/// The kind of conversion being performed.
enum CheckedConversionKind {
  /// An implicit conversion.
  CCK_ImplicitConversion,
  /// A C-style cast.
  CCK_CStyleCast,
  /// A functional-style cast.
  CCK_FunctionalCast,
  /// A cast other than a C-style cast.
  CCK_OtherCast,
  /// A conversion for an operand of a builtin overloaded operator.
  CCK_ForBuiltinOverloadedOp
};

static bool isCast(CheckedConversionKind CCK) {
  return CCK == CCK_CStyleCast || CCK == CCK_FunctionalCast ||
         CCK == CCK_OtherCast;
}

/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit
/// cast.  If there is already an implicit cast, merge into the existing one.
/// If isLvalue, the result of the cast is an lvalue.
ExprResult
ImpCastExprToType(Expr *E, QualType Type, CastKind CK,
                  ExprValueKind VK = VK_PRValue,
                  const CXXCastPath *BasePath = nullptr,
                  CheckedConversionKind CCK = CCK_ImplicitConversion);

/// ScalarTypeToBooleanCastKind - Returns the cast kind corresponding
/// to the conversion from scalar type ScalarTy to the Boolean type.
static CastKind ScalarTypeToBooleanCastKind(QualType ScalarTy);

/// IgnoredValueConversions - Given that an expression's result is
/// syntactically ignored, perform any conversions that are
/// required.
ExprResult IgnoredValueConversions(Expr *E);

// UsualUnaryConversions - promotes integers (C99 6.3.1.1p2) and converts
// functions and arrays to their respective pointers (C99 6.3.2.1).
ExprResult UsualUnaryConversions(Expr *E);

/// CallExprUnaryConversions - a special case of an unary conversion
/// performed on a function designator of a call expression.
ExprResult CallExprUnaryConversions(Expr *E);

// DefaultFunctionArrayConversion - converts functions and arrays
// to their respective pointers (C99 6.3.2.1).
ExprResult DefaultFunctionArrayConversion(Expr *E, bool Diagnose = true);

// DefaultFunctionArrayLvalueConversion - converts functions and
// arrays to their respective pointers and performs the
// lvalue-to-rvalue conversion.
ExprResult DefaultFunctionArrayLvalueConversion(Expr *E,
                                                bool Diagnose = true);

// DefaultLvalueConversion - performs lvalue-to-rvalue conversion on
// the operand. This function is a no-op if the operand has a function type
// or an array type.
ExprResult DefaultLvalueConversion(Expr *E);

// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that
// do not have a prototype. Integer promotions are performed on each
// argument, and arguments that have type float are promoted to double.
ExprResult DefaultArgumentPromotion(Expr *E);

/// If \p E is a prvalue denoting an unmaterialized temporary, materialize
/// it as an xvalue. In C++98, the result will still be a prvalue, because
/// we don't have xvalues there.
ExprResult TemporaryMaterializationConversion(Expr *E);

// Used for emitting the right warning by DefaultVariadicArgumentPromotion
enum VariadicCallType {
  VariadicFunction,
  VariadicBlock,
  VariadicMethod,
  VariadicConstructor,
  VariadicDoesNotApply
};

VariadicCallType getVariadicCallType(FunctionDecl *FDecl,
                                     const FunctionProtoType *Proto,
                                     Expr *Fn);

// Used for determining in which context a type is allowed to be passed to a
// vararg function.
enum VarArgKind {
  VAK_Valid,
  VAK_ValidInCXX11,
  VAK_Undefined,
  VAK_MSVCUndefined,
  VAK_Invalid
};

// Determines which VarArgKind fits an expression.
VarArgKind isValidVarArgType(const QualType &Ty);

/// Check to see if the given expression is a valid argument to a variadic
/// function, issuing a diagnostic if not.
void checkVariadicArgument(const Expr *E, VariadicCallType CT);

/// Check whether the given statement can have musttail applied to it,
/// issuing a diagnostic and returning false if not. In the success case,
/// the statement is rewritten to remove implicit nodes from the return
/// value.
bool checkAndRewriteMustTailAttr(Stmt *St, const Attr &MTA);

11435private:
/// Check whether the given statement can have musttail applied to it,
/// issuing a diagnostic and returning false if not.
bool checkMustTailAttr(const Stmt *St, const Attr &MTA);

11440public:
/// Check to see if a given expression could have '.c_str()' called on it.
bool hasCStrMethod(const Expr *E);

/// GatherArgumentsForCall - Collector argument expressions for various
/// form of call prototypes.
bool GatherArgumentsForCall(SourceLocation CallLoc, FunctionDecl *FDecl,
                            const FunctionProtoType *Proto,
                            unsigned FirstParam, ArrayRef<Expr *> Args,
                            SmallVectorImpl<Expr *> &AllArgs,
                            VariadicCallType CallType = VariadicDoesNotApply,
                            bool AllowExplicit = false,
                            bool IsListInitialization = false);

// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but
// will create a runtime trap if the resulting type is not a POD type.
ExprResult DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT,
                                            FunctionDecl *FDecl);

/// Context in which we're performing a usual arithmetic conversion.
enum ArithConvKind {
  /// An arithmetic operation.
  ACK_Arithmetic,
  /// A bitwise operation.
  ACK_BitwiseOp,
  /// A comparison.
  ACK_Comparison,
  /// A conditional (?:) operator.
  ACK_Conditional,
  /// A compound assignment expression.
  ACK_CompAssign,
};

// UsualArithmeticConversions - performs the UsualUnaryConversions on it's
// operands and then handles various conversions that are common to binary
// operators (C99 6.3.1.8). If both operands aren't arithmetic, this
// routine returns the first non-arithmetic type found. The client is
// responsible for emitting appropriate error diagnostics.
QualType UsualArithmeticConversions(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc, ArithConvKind ACK);

/// AssignConvertType - All of the 'assignment' semantic checks return this
/// enum to indicate whether the assignment was allowed.  These checks are
/// done for simple assignments, as well as initialization, return from
/// function, argument passing, etc.  The query is phrased in terms of a
/// source and destination type.
enum AssignConvertType {
  /// Compatible - the types are compatible according to the standard.
  Compatible,

  /// PointerToInt - The assignment converts a pointer to an int, which we
  /// accept as an extension.
  PointerToInt,

  /// IntToPointer - The assignment converts an int to a pointer, which we
  /// accept as an extension.
  IntToPointer,

  /// FunctionVoidPointer - The assignment is between a function pointer and
  /// void*, which the standard doesn't allow, but we accept as an extension.
  FunctionVoidPointer,

  /// IncompatiblePointer - The assignment is between two pointers types that
  /// are not compatible, but we accept them as an extension.
  IncompatiblePointer,

  /// IncompatibleFunctionPointer - The assignment is between two function
  /// pointers types that are not compatible, but we accept them as an
  /// extension.
  IncompatibleFunctionPointer,

  /// IncompatiblePointerSign - The assignment is between two pointers types
  /// which point to integers which have a different sign, but are otherwise
  /// identical. This is a subset of the above, but broken out because it's by
  /// far the most common case of incompatible pointers.
  IncompatiblePointerSign,

  /// CompatiblePointerDiscardsQualifiers - The assignment discards
  /// c/v/r qualifiers, which we accept as an extension.
  CompatiblePointerDiscardsQualifiers,

  /// IncompatiblePointerDiscardsQualifiers - The assignment
  /// discards qualifiers that we don't permit to be discarded,
  /// like address spaces.
  IncompatiblePointerDiscardsQualifiers,

  /// IncompatibleNestedPointerAddressSpaceMismatch - The assignment
  /// changes address spaces in nested pointer types which is not allowed.
  /// For instance, converting __private int ** to __generic int ** is
  /// illegal even though __private could be converted to __generic.
  IncompatibleNestedPointerAddressSpaceMismatch,

  /// IncompatibleNestedPointerQualifiers - The assignment is between two
  /// nested pointer types, and the qualifiers other than the first two
  /// levels differ e.g. char ** -> const char **, but we accept them as an
  /// extension.
  IncompatibleNestedPointerQualifiers,

  /// IncompatibleVectors - The assignment is between two vector types that
  /// have the same size, which we accept as an extension.
  IncompatibleVectors,

  /// IntToBlockPointer - The assignment converts an int to a block
  /// pointer. We disallow this.
  IntToBlockPointer,

  /// IncompatibleBlockPointer - The assignment is between two block
  /// pointers types that are not compatible.
  IncompatibleBlockPointer,

  /// IncompatibleObjCQualifiedId - The assignment is between a qualified
  /// id type and something else (that is incompatible with it). For example,
  /// "id <XXX>" = "Foo *", where "Foo *" doesn't implement the XXX protocol.
  IncompatibleObjCQualifiedId,

  /// IncompatibleObjCWeakRef - Assigning a weak-unavailable object to an
  /// object with __weak qualifier.
  IncompatibleObjCWeakRef,

  /// Incompatible - We reject this conversion outright, it is invalid to
  /// represent it in the AST.
  Incompatible
};

/// DiagnoseAssignmentResult - Emit a diagnostic, if required, for the
/// assignment conversion type specified by ConvTy.  This returns true if the
/// conversion was invalid or false if the conversion was accepted.
bool DiagnoseAssignmentResult(AssignConvertType ConvTy,
                              SourceLocation Loc,
                              QualType DstType, QualType SrcType,
                              Expr *SrcExpr, AssignmentAction Action,
                              bool *Complained = nullptr);

/// IsValueInFlagEnum - Determine if a value is allowed as part of a flag
/// enum. If AllowMask is true, then we also allow the complement of a valid
/// value, to be used as a mask.
bool IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
                       bool AllowMask) const;

/// DiagnoseAssignmentEnum - Warn if assignment to enum is a constant
/// integer not in the range of enum values.
void DiagnoseAssignmentEnum(QualType DstType, QualType SrcType,
                            Expr *SrcExpr);

/// CheckAssignmentConstraints - Perform type checking for assignment,
/// argument passing, variable initialization, and function return values.
/// C99 6.5.16.
AssignConvertType CheckAssignmentConstraints(SourceLocation Loc,
                                             QualType LHSType,
                                             QualType RHSType);

/// Check assignment constraints and optionally prepare for a conversion of
/// the RHS to the LHS type. The conversion is prepared for if ConvertRHS
/// is true.
AssignConvertType CheckAssignmentConstraints(QualType LHSType,
                                             ExprResult &RHS,
                                             CastKind &Kind,
                                             bool ConvertRHS = true);

/// Check assignment constraints for an assignment of RHS to LHSType.
///
/// \param LHSType The destination type for the assignment.
/// \param RHS The source expression for the assignment.
/// \param Diagnose If \c true, diagnostics may be produced when checking
///        for assignability. If a diagnostic is produced, \p RHS will be
///        set to ExprError(). Note that this function may still return
///        without producing a diagnostic, even for an invalid assignment.
/// \param DiagnoseCFAudited If \c true, the target is a function parameter
///        in an audited Core Foundation API and does not need to be checked
///        for ARC retain issues.
/// \param ConvertRHS If \c true, \p RHS will be updated to model the
///        conversions necessary to perform the assignment. If \c false,
///        \p Diagnose must also be \c false.
AssignConvertType CheckSingleAssignmentConstraints(
    QualType LHSType, ExprResult &RHS, bool Diagnose = true,
    bool DiagnoseCFAudited = false, bool ConvertRHS = true);

// If the lhs type is a transparent union, check whether we
// can initialize the transparent union with the given expression.
AssignConvertType CheckTransparentUnionArgumentConstraints(QualType ArgType,
                                                           ExprResult &RHS);

bool IsStringLiteralToNonConstPointerConversion(Expr *From, QualType ToType);

bool CheckExceptionSpecCompatibility(Expr *From, QualType ToType);

ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     AssignmentAction Action,
                                     bool AllowExplicit = false);
ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     const ImplicitConversionSequence& ICS,
                                     AssignmentAction Action,
                                     CheckedConversionKind CCK
                                        = CCK_ImplicitConversion);
ExprResult PerformImplicitConversion(Expr *From, QualType ToType,
                                     const StandardConversionSequence& SCS,
                                     AssignmentAction Action,
                                     CheckedConversionKind CCK);

ExprResult PerformQualificationConversion(
    Expr *E, QualType Ty, ExprValueKind VK = VK_PRValue,
    CheckedConversionKind CCK = CCK_ImplicitConversion);

/// the following "Check" methods will return a valid/converted QualType
/// or a null QualType (indicating an error diagnostic was issued).

/// type checking binary operators (subroutines of CreateBuiltinBinOp).
QualType InvalidOperands(SourceLocation Loc, ExprResult &LHS,
                         ExprResult &RHS);
QualType InvalidLogicalVectorOperands(SourceLocation Loc, ExprResult &LHS,
                               ExprResult &RHS);
QualType CheckPointerToMemberOperands( // C++ 5.5
  ExprResult &LHS, ExprResult &RHS, ExprValueKind &VK,
  SourceLocation OpLoc, bool isIndirect);
QualType CheckMultiplyDivideOperands( // C99 6.5.5
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc, bool IsCompAssign,
  bool IsDivide);
QualType CheckRemainderOperands( // C99 6.5.5
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  bool IsCompAssign = false);
QualType CheckAdditionOperands( // C99 6.5.6
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc, QualType* CompLHSTy = nullptr);
QualType CheckSubtractionOperands( // C99 6.5.6
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  QualType* CompLHSTy = nullptr);
QualType CheckShiftOperands( // C99 6.5.7
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc, bool IsCompAssign = false);
void CheckPtrComparisonWithNullChar(ExprResult &E, ExprResult &NullE);
QualType CheckCompareOperands( // C99 6.5.8/9
    ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
    BinaryOperatorKind Opc);
QualType CheckBitwiseOperands( // C99 6.5.[10...12]
    ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
    BinaryOperatorKind Opc);
QualType CheckLogicalOperands( // C99 6.5.[13,14]
  ExprResult &LHS, ExprResult &RHS, SourceLocation Loc,
  BinaryOperatorKind Opc);
// CheckAssignmentOperands is used for both simple and compound assignment.
// For simple assignment, pass both expressions and a null converted type.
// For compound assignment, pass both expressions and the converted type.
QualType CheckAssignmentOperands( // C99 6.5.16.[1,2]
  Expr *LHSExpr, ExprResult &RHS, SourceLocation Loc, QualType CompoundType);

ExprResult checkPseudoObjectIncDec(Scope *S, SourceLocation OpLoc,
                                   UnaryOperatorKind Opcode, Expr *Op);
ExprResult checkPseudoObjectAssignment(Scope *S, SourceLocation OpLoc,
                                       BinaryOperatorKind Opcode,
                                       Expr *LHS, Expr *RHS);
ExprResult checkPseudoObjectRValue(Expr *E);
Expr *recreateSyntacticForm(PseudoObjectExpr *E);

QualType CheckConditionalOperands( // C99 6.5.15
  ExprResult &Cond, ExprResult &LHS, ExprResult &RHS,
  ExprValueKind &VK, ExprObjectKind &OK, SourceLocation QuestionLoc);
QualType CXXCheckConditionalOperands( // C++ 5.16
  ExprResult &cond, ExprResult &lhs, ExprResult &rhs,
  ExprValueKind &VK, ExprObjectKind &OK, SourceLocation questionLoc);
QualType CheckVectorConditionalTypes(ExprResult &Cond, ExprResult &LHS,
                                     ExprResult &RHS,
                                     SourceLocation QuestionLoc);
QualType FindCompositePointerType(SourceLocation Loc, Expr *&E1, Expr *&E2,
                                  bool ConvertArgs = true);
QualType FindCompositePointerType(SourceLocation Loc,
                                  ExprResult &E1, ExprResult &E2,
                                  bool ConvertArgs = true) {
  Expr *E1Tmp = E1.get(), *E2Tmp = E2.get();
  QualType Composite =
      FindCompositePointerType(Loc, E1Tmp, E2Tmp, ConvertArgs);
  E1 = E1Tmp;
  E2 = E2Tmp;
  return Composite;
}

QualType FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS,
                                      SourceLocation QuestionLoc);

bool DiagnoseConditionalForNull(Expr *LHSExpr, Expr *RHSExpr,
                                SourceLocation QuestionLoc);

void DiagnoseAlwaysNonNullPointer(Expr *E,
                                  Expr::NullPointerConstantKind NullType,
                                  bool IsEqual, SourceRange Range);

/// type checking for vector binary operators.
QualType CheckVectorOperands(ExprResult &LHS, ExprResult &RHS,
                             SourceLocation Loc, bool IsCompAssign,
                             bool AllowBothBool, bool AllowBoolConversion);
QualType GetSignedVectorType(QualType V);
QualType CheckVectorCompareOperands(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc,
                                    BinaryOperatorKind Opc);
QualType CheckVectorLogicalOperands(ExprResult &LHS, ExprResult &RHS,
                                    SourceLocation Loc);

/// Type checking for matrix binary operators.
QualType CheckMatrixElementwiseOperands(ExprResult &LHS, ExprResult &RHS,
                                        SourceLocation Loc,
                                        bool IsCompAssign);
QualType CheckMatrixMultiplyOperands(ExprResult &LHS, ExprResult &RHS,
                                     SourceLocation Loc, bool IsCompAssign);

bool isValidSveBitcast(QualType srcType, QualType destType);

bool areMatrixTypesOfTheSameDimension(QualType srcTy, QualType destTy);

bool areVectorTypesSameSize(QualType srcType, QualType destType);
bool areLaxCompatibleVectorTypes(QualType srcType, QualType destType);
bool isLaxVectorConversion(QualType srcType, QualType destType);

/// type checking declaration initializers (C99 6.7.8)
bool CheckForConstantInitializer(Expr *e, QualType t);

// type checking C++ declaration initializers (C++ [dcl.init]).

/// ReferenceCompareResult - Expresses the result of comparing two
/// types (cv1 T1 and cv2 T2) to determine their compatibility for the
/// purposes of initialization by reference (C++ [dcl.init.ref]p4).
enum ReferenceCompareResult {
  /// Ref_Incompatible - The two types are incompatible, so direct
  /// reference binding is not possible.
  Ref_Incompatible = 0,
  /// Ref_Related - The two types are reference-related, which means
  /// that their unqualified forms (T1 and T2) are either the same
  /// or T1 is a base class of T2.
  Ref_Related,
  /// Ref_Compatible - The two types are reference-compatible.
  Ref_Compatible
};

// Fake up a scoped enumeration that still contextually converts to bool.
struct ReferenceConversionsScope {
  /// The conversions that would be performed on an lvalue of type T2 when
  /// binding a reference of type T1 to it, as determined when evaluating
  /// whether T1 is reference-compatible with T2.
  enum ReferenceConversions {
    Qualification = 0x1,
    NestedQualification = 0x2,
    Function = 0x4,
    DerivedToBase = 0x8,
    ObjC = 0x10,
    ObjCLifetime = 0x20,

    LLVM_MARK_AS_BITMASK_ENUM(/*LargestValue=*/ObjCLifetime)LLVM_BITMASK_LARGEST_ENUMERATOR = ObjCLifetime
  };
};
using ReferenceConversions = ReferenceConversionsScope::ReferenceConversions;

ReferenceCompareResult
CompareReferenceRelationship(SourceLocation Loc, QualType T1, QualType T2,
                             ReferenceConversions *Conv = nullptr);

ExprResult checkUnknownAnyCast(SourceRange TypeRange, QualType CastType,
                               Expr *CastExpr, CastKind &CastKind,
                               ExprValueKind &VK, CXXCastPath &Path);

/// Force an expression with unknown-type to an expression of the
/// given type.
ExprResult forceUnknownAnyToType(Expr *E, QualType ToType);

/// Type-check an expression that's being passed to an
/// __unknown_anytype parameter.
ExprResult checkUnknownAnyArg(SourceLocation callLoc,
                              Expr *result, QualType &paramType);

// CheckMatrixCast - Check type constraints for matrix casts.
// We allow casting between matrixes of the same dimensions i.e. when they
// have the same number of rows and column. Returns true if the cast is
// invalid.
bool CheckMatrixCast(SourceRange R, QualType DestTy, QualType SrcTy,
                     CastKind &Kind);

// CheckVectorCast - check type constraints for vectors.
// Since vectors are an extension, there are no C standard reference for this.
// We allow casting between vectors and integer datatypes of the same size.
// returns true if the cast is invalid
bool CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty,
                     CastKind &Kind);

/// Prepare `SplattedExpr` for a vector splat operation, adding
/// implicit casts if necessary.
ExprResult prepareVectorSplat(QualType VectorTy, Expr *SplattedExpr);

// CheckExtVectorCast - check type constraints for extended vectors.
// Since vectors are an extension, there are no C standard reference for this.
// We allow casting between vectors and integer datatypes of the same size,
// or vectors and the element type of that vector.
// returns the cast expr
ExprResult CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr,
                              CastKind &Kind);

ExprResult BuildCXXFunctionalCastExpr(TypeSourceInfo *TInfo, QualType Type,
                                      SourceLocation LParenLoc,
                                      Expr *CastExpr,
                                      SourceLocation RParenLoc);

enum ARCConversionResult { ACR_okay, ACR_unbridged, ACR_error };

/// Checks for invalid conversions and casts between
/// retainable pointers and other pointer kinds for ARC and Weak.
ARCConversionResult CheckObjCConversion(SourceRange castRange,
                                        QualType castType, Expr *&op,
                                        CheckedConversionKind CCK,
                                        bool Diagnose = true,
                                        bool DiagnoseCFAudited = false,
                                        BinaryOperatorKind Opc = BO_PtrMemD
                                        );

Expr *stripARCUnbridgedCast(Expr *e);
void diagnoseARCUnbridgedCast(Expr *e);

bool CheckObjCARCUnavailableWeakConversion(QualType castType,
                                           QualType ExprType);

/// checkRetainCycles - Check whether an Objective-C message send
/// might create an obvious retain cycle.
void checkRetainCycles(ObjCMessageExpr *msg);
void checkRetainCycles(Expr *receiver, Expr *argument);
void checkRetainCycles(VarDecl *Var, Expr *Init);

/// checkUnsafeAssigns - Check whether +1 expr is being assigned
/// to weak/__unsafe_unretained type.
bool checkUnsafeAssigns(SourceLocation Loc, QualType LHS, Expr *RHS);

/// checkUnsafeExprAssigns - Check whether +1 expr is being assigned
/// to weak/__unsafe_unretained expression.
void checkUnsafeExprAssigns(SourceLocation Loc, Expr *LHS, Expr *RHS);

/// CheckMessageArgumentTypes - Check types in an Obj-C message send.
/// \param Method - May be null.
/// \param [out] ReturnType - The return type of the send.
/// \return true iff there were any incompatible types.
bool CheckMessageArgumentTypes(const Expr *Receiver, QualType ReceiverType,
                               MultiExprArg Args, Selector Sel,
                               ArrayRef<SourceLocation> SelectorLocs,
                               ObjCMethodDecl *Method, bool isClassMessage,
                               bool isSuperMessage, SourceLocation lbrac,
                               SourceLocation rbrac, SourceRange RecRange,
                               QualType &ReturnType, ExprValueKind &VK);

/// Determine the result of a message send expression based on
/// the type of the receiver, the method expected to receive the message,
/// and the form of the message send.
QualType getMessageSendResultType(const Expr *Receiver, QualType ReceiverType,
                                  ObjCMethodDecl *Method, bool isClassMessage,
                                  bool isSuperMessage);

/// If the given expression involves a message send to a method
/// with a related result type, emit a note describing what happened.
void EmitRelatedResultTypeNote(const Expr *E);

/// Given that we had incompatible pointer types in a return
/// statement, check whether we're in a method with a related result
/// type, and if so, emit a note describing what happened.
void EmitRelatedResultTypeNoteForReturn(QualType destType);

class ConditionResult {
  Decl *ConditionVar;
  FullExprArg Condition;
  bool Invalid;
  bool HasKnownValue;
  bool KnownValue;

  friend class Sema;
  ConditionResult(Sema &S, Decl *ConditionVar, FullExprArg Condition,
                  bool IsConstexpr)
      : ConditionVar(ConditionVar), Condition(Condition), Invalid(false),
        HasKnownValue(IsConstexpr && Condition.get() &&
                      !Condition.get()->isValueDependent()),
        KnownValue(HasKnownValue &&
                   !!Condition.get()->EvaluateKnownConstInt(S.Context)) {}
  explicit ConditionResult(bool Invalid)
      : ConditionVar(nullptr), Condition(nullptr), Invalid(Invalid),
        HasKnownValue(false), KnownValue(false) {}

public:
  ConditionResult() : ConditionResult(false) {}
  bool isInvalid() const { return Invalid; }
  std::pair<VarDecl *, Expr *> get() const {
    return std::make_pair(cast_or_null<VarDecl>(ConditionVar),
                          Condition.get());
  }
  llvm::Optional<bool> getKnownValue() const {
    if (!HasKnownValue)
      return None;
    return KnownValue;
  }
};
static ConditionResult ConditionError() { return ConditionResult(true); }

enum class ConditionKind {
  Boolean,     ///< A boolean condition, from 'if', 'while', 'for', or 'do'.
  ConstexprIf, ///< A constant boolean condition from 'if constexpr'.
  Switch       ///< An integral condition for a 'switch' statement.
};

ConditionResult ActOnCondition(Scope *S, SourceLocation Loc,
                               Expr *SubExpr, ConditionKind CK);

ConditionResult ActOnConditionVariable(Decl *ConditionVar,
                                       SourceLocation StmtLoc,
                                       ConditionKind CK);

DeclResult ActOnCXXConditionDeclaration(Scope *S, Declarator &D);

ExprResult CheckConditionVariable(VarDecl *ConditionVar,
                                  SourceLocation StmtLoc,
                                  ConditionKind CK);
ExprResult CheckSwitchCondition(SourceLocation SwitchLoc, Expr *Cond);

/// CheckBooleanCondition - Diagnose problems involving the use of
/// the given expression as a boolean condition (e.g. in an if
/// statement).  Also performs the standard function and array
/// decays, possibly changing the input variable.
///
/// \param Loc - A location associated with the condition, e.g. the
/// 'if' keyword.
/// \return true iff there were any errors
ExprResult CheckBooleanCondition(SourceLocation Loc, Expr *E,
                                 bool IsConstexpr = false);

/// ActOnExplicitBoolSpecifier - Build an ExplicitSpecifier from an expression
/// found in an explicit(bool) specifier.
ExplicitSpecifier ActOnExplicitBoolSpecifier(Expr *E);

/// tryResolveExplicitSpecifier - Attempt to resolve the explict specifier.
/// Returns true if the explicit specifier is now resolved.
bool tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec);

/// DiagnoseAssignmentAsCondition - Given that an expression is
/// being used as a boolean condition, warn if it's an assignment.
void DiagnoseAssignmentAsCondition(Expr *E);

/// Redundant parentheses over an equality comparison can indicate
/// that the user intended an assignment used as condition.
void DiagnoseEqualityWithExtraParens(ParenExpr *ParenE);

/// CheckCXXBooleanCondition - Returns true if conversion to bool is invalid.
ExprResult CheckCXXBooleanCondition(Expr *CondExpr, bool IsConstexpr = false);

/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
/// the specified width and sign.  If an overflow occurs, detect it and emit
/// the specified diagnostic.
void ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &OldVal,
                                        unsigned NewWidth, bool NewSign,
                                        SourceLocation Loc, unsigned DiagID);

/// Checks that the Objective-C declaration is declared in the global scope.
/// Emits an error and marks the declaration as invalid if it's not declared
/// in the global scope.
bool CheckObjCDeclScope(Decl *D);

/// Abstract base class used for diagnosing integer constant
/// expression violations.
class VerifyICEDiagnoser {
public:
  bool Suppress;

  VerifyICEDiagnoser(bool Suppress = false) : Suppress(Suppress) { }

  virtual SemaDiagnosticBuilder
  diagnoseNotICEType(Sema &S, SourceLocation Loc, QualType T);
  virtual SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
                                               SourceLocation Loc) = 0;
  virtual SemaDiagnosticBuilder diagnoseFold(Sema &S, SourceLocation Loc);
  virtual ~VerifyICEDiagnoser() {}
};

enum AllowFoldKind {
  NoFold,
  AllowFold,
};

/// VerifyIntegerConstantExpression - Verifies that an expression is an ICE,
/// and reports the appropriate diagnostics. Returns false on success.
/// Can optionally return the value of the expression.
ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
                                           VerifyICEDiagnoser &Diagnoser,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E, llvm::APSInt *Result,
                                           unsigned DiagID,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E,
                                           llvm::APSInt *Result = nullptr,
                                           AllowFoldKind CanFold = NoFold);
ExprResult VerifyIntegerConstantExpression(Expr *E,
                                           AllowFoldKind CanFold = NoFold) {
  return VerifyIntegerConstantExpression(E, nullptr, CanFold);
}

/// VerifyBitField - verifies that a bit field expression is an ICE and has
/// the correct width, and that the field type is valid.
/// Returns false on success.
/// Can optionally return whether the bit-field is of width 0
ExprResult VerifyBitField(SourceLocation FieldLoc, IdentifierInfo *FieldName,
                          QualType FieldTy, bool IsMsStruct,
                          Expr *BitWidth, bool *ZeroWidth = nullptr);

12039private:
unsigned ForceCUDAHostDeviceDepth = 0;

12042public:
/// Increments our count of the number of times we've seen a pragma forcing
/// functions to be __host__ __device__.  So long as this count is greater
/// than zero, all functions encountered will be __host__ __device__.
void PushForceCUDAHostDevice();

/// Decrements our count of the number of times we've seen a pragma forcing
/// functions to be __host__ __device__.  Returns false if the count is 0
/// before incrementing, so you can emit an error.
bool PopForceCUDAHostDevice();

/// Diagnostics that are emitted only if we discover that the given function
/// must be codegen'ed.  Because handling these correctly adds overhead to
/// compilation, this is currently only enabled for CUDA compilations.
llvm::DenseMap<CanonicalDeclPtr<FunctionDecl>,
               std::vector<PartialDiagnosticAt>>
    DeviceDeferredDiags;

/// A pair of a canonical FunctionDecl and a SourceLocation.  When used as the
/// key in a hashtable, both the FD and location are hashed.
struct FunctionDeclAndLoc {
  CanonicalDeclPtr<FunctionDecl> FD;
  SourceLocation Loc;
};

/// FunctionDecls and SourceLocations for which CheckCUDACall has emitted a
/// (maybe deferred) "bad call" diagnostic.  We use this to avoid emitting the
/// same deferred diag twice.
llvm::DenseSet<FunctionDeclAndLoc> LocsWithCUDACallDiags;

/// An inverse call graph, mapping known-emitted functions to one of their
/// known-emitted callers (plus the location of the call).
///
/// Functions that we can tell a priori must be emitted aren't added to this
/// map.
llvm::DenseMap</* Callee = */ CanonicalDeclPtr<FunctionDecl>,
               /* Caller = */ FunctionDeclAndLoc>
    DeviceKnownEmittedFns;

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurContext is a __host__ function, does not emit any diagnostics
///   unless \p EmitOnBothSides is true.
/// - If CurContext is a __device__ or __global__ function, emits the
///   diagnostics immediately.
/// - If CurContext is a __host__ __device__ function and we are compiling for
///   the device, creates a diagnostic which is emitted if and when we realize
///   that the function will be codegen'ed.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in CUDA device code.
///  if (CUDADiagIfDeviceCode(Loc, diag::err_cuda_vla) << CurrentCUDATarget())
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder CUDADiagIfDeviceCode(SourceLocation Loc,
                                           unsigned DiagID);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as host code".
///
/// Same as CUDADiagIfDeviceCode, with "host" and "device" switched.
SemaDiagnosticBuilder CUDADiagIfHostCode(SourceLocation Loc, unsigned DiagID);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurContext is a `declare target` function or it is known that the
/// function is emitted for the device, emits the diagnostics immediately.
/// - If CurContext is a non-`declare target` function and we are compiling
///   for the device, creates a diagnostic which is emitted if and when we
///   realize that the function will be codegen'ed.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in NVPTX device code.
///  if (diagIfOpenMPDeviceCode(Loc, diag::err_vla_unsupported))
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder
diagIfOpenMPDeviceCode(SourceLocation Loc, unsigned DiagID, FunctionDecl *FD);

/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as host code".
///
/// - If CurContext is a `declare target` function or it is known that the
/// function is emitted for the host, emits the diagnostics immediately.
/// - If CurContext is a non-host function, just ignore it.
///
/// Example usage:
///
///  // Variable-length arrays are not allowed in NVPTX device code.
///  if (diagIfOpenMPHostode(Loc, diag::err_vla_unsupported))
///    return ExprError();
///  // Otherwise, continue parsing as normal.
SemaDiagnosticBuilder diagIfOpenMPHostCode(SourceLocation Loc,
                                           unsigned DiagID, FunctionDecl *FD);

SemaDiagnosticBuilder targetDiag(SourceLocation Loc, unsigned DiagID,
                                 FunctionDecl *FD = nullptr);
SemaDiagnosticBuilder targetDiag(SourceLocation Loc,
                                 const PartialDiagnostic &PD,
                                 FunctionDecl *FD = nullptr) {
  return targetDiag(Loc, PD.getDiagID(), FD) << PD;
}

/// Check if the expression is allowed to be used in expressions for the
/// offloading devices.
void checkDeviceDecl(ValueDecl *D, SourceLocation Loc);

enum CUDAFunctionTarget {
  CFT_Device,
  CFT_Global,
  CFT_Host,
  CFT_HostDevice,
  CFT_InvalidTarget
};

/// Determines whether the given function is a CUDA device/host/kernel/etc.
/// function.
///
/// Use this rather than examining the function's attributes yourself -- you
/// will get it wrong.  Returns CFT_Host if D is null.
CUDAFunctionTarget IdentifyCUDATarget(const FunctionDecl *D,
                                      bool IgnoreImplicitHDAttr = false);
CUDAFunctionTarget IdentifyCUDATarget(const ParsedAttributesView &Attrs);

enum CUDAVariableTarget {
  CVT_Device,  /// Emitted on device side with a shadow variable on host side
  CVT_Host,    /// Emitted on host side only
  CVT_Both,    /// Emitted on both sides with different addresses
  CVT_Unified, /// Emitted as a unified address, e.g. managed variables
};
/// Determines whether the given variable is emitted on host or device side.
CUDAVariableTarget IdentifyCUDATarget(const VarDecl *D);

/// Gets the CUDA target for the current context.
CUDAFunctionTarget CurrentCUDATarget() {
  return IdentifyCUDATarget(dyn_cast<FunctionDecl>(CurContext));
}

static bool isCUDAImplicitHostDeviceFunction(const FunctionDecl *D);

// CUDA function call preference. Must be ordered numerically from
// worst to best.
enum CUDAFunctionPreference {
  CFP_Never,      // Invalid caller/callee combination.
  CFP_WrongSide,  // Calls from host-device to host or device
                  // function that do not match current compilation
                  // mode.
  CFP_HostDevice, // Any calls to host/device functions.
  CFP_SameSide,   // Calls from host-device to host or device
                  // function matching current compilation mode.
  CFP_Native,     // host-to-host or device-to-device calls.
};

/// Identifies relative preference of a given Caller/Callee
/// combination, based on their host/device attributes.
/// \param Caller function which needs address of \p Callee.
///               nullptr in case of global context.
/// \param Callee target function
///
/// \returns preference value for particular Caller/Callee combination.
CUDAFunctionPreference IdentifyCUDAPreference(const FunctionDecl *Caller,
                                              const FunctionDecl *Callee);

/// Determines whether Caller may invoke Callee, based on their CUDA
/// host/device attributes.  Returns false if the call is not allowed.
///
/// Note: Will return true for CFP_WrongSide calls.  These may appear in
/// semantically correct CUDA programs, but only if they're never codegen'ed.
bool IsAllowedCUDACall(const FunctionDecl *Caller,
                       const FunctionDecl *Callee) {
  return IdentifyCUDAPreference(Caller, Callee) != CFP_Never;
}

/// May add implicit CUDAHostAttr and CUDADeviceAttr attributes to FD,
/// depending on FD and the current compilation settings.
void maybeAddCUDAHostDeviceAttrs(FunctionDecl *FD,
                                 const LookupResult &Previous);

/// May add implicit CUDAConstantAttr attribute to VD, depending on VD
/// and current compilation settings.
void MaybeAddCUDAConstantAttr(VarDecl *VD);

12228public:
/// Check whether we're allowed to call Callee from the current context.
///
/// - If the call is never allowed in a semantically-correct program
///   (CFP_Never), emits an error and returns false.
///
/// - If the call is allowed in semantically-correct programs, but only if
///   it's never codegen'ed (CFP_WrongSide), creates a deferred diagnostic to
///   be emitted if and when the caller is codegen'ed, and returns true.
///
///   Will only create deferred diagnostics for a given SourceLocation once,
///   so you can safely call this multiple times without generating duplicate
///   deferred errors.
///
/// - Otherwise, returns true without emitting any diagnostics.
bool CheckCUDACall(SourceLocation Loc, FunctionDecl *Callee);

void CUDACheckLambdaCapture(CXXMethodDecl *D, const sema::Capture &Capture);

/// Set __device__ or __host__ __device__ attributes on the given lambda
/// operator() method.
///
/// CUDA lambdas by default is host device function unless it has explicit
/// host or device attribute.
void CUDASetLambdaAttrs(CXXMethodDecl *Method);

/// Finds a function in \p Matches with highest calling priority
/// from \p Caller context and erases all functions with lower
/// calling priority.
void EraseUnwantedCUDAMatches(
    const FunctionDecl *Caller,
    SmallVectorImpl<std::pair<DeclAccessPair, FunctionDecl *>> &Matches);

/// Given a implicit special member, infer its CUDA target from the
/// calls it needs to make to underlying base/field special members.
/// \param ClassDecl the class for which the member is being created.
/// \param CSM the kind of special member.
/// \param MemberDecl the special member itself.
/// \param ConstRHS true if this is a copy operation with a const object on
///        its RHS.
/// \param Diagnose true if this call should emit diagnostics.
/// \return true if there was an error inferring.
/// The result of this call is implicit CUDA target attribute(s) attached to
/// the member declaration.
bool inferCUDATargetForImplicitSpecialMember(CXXRecordDecl *ClassDecl,
                                             CXXSpecialMember CSM,
                                             CXXMethodDecl *MemberDecl,
                                             bool ConstRHS,
                                             bool Diagnose);

/// \return true if \p CD can be considered empty according to CUDA
/// (E.2.3.1 in CUDA 7.5 Programming guide).
bool isEmptyCudaConstructor(SourceLocation Loc, CXXConstructorDecl *CD);
bool isEmptyCudaDestructor(SourceLocation Loc, CXXDestructorDecl *CD);

// \brief Checks that initializers of \p Var satisfy CUDA restrictions. In
// case of error emits appropriate diagnostic and invalidates \p Var.
//
// \details CUDA allows only empty constructors as initializers for global
// variables (see E.2.3.1, CUDA 7.5). The same restriction also applies to all
// __shared__ variables whether they are local or not (they all are implicitly
// static in CUDA). One exception is that CUDA allows constant initializers
// for __constant__ and __device__ variables.
void checkAllowedCUDAInitializer(VarDecl *VD);

/// Check whether NewFD is a valid overload for CUDA. Emits
/// diagnostics and invalidates NewFD if not.
void checkCUDATargetOverload(FunctionDecl *NewFD,
                             const LookupResult &Previous);
/// Copies target attributes from the template TD to the function FD.
void inheritCUDATargetAttrs(FunctionDecl *FD, const FunctionTemplateDecl &TD);

/// Returns the name of the launch configuration function.  This is the name
/// of the function that will be called to configure kernel call, with the
/// parameters specified via <<<>>>.
std::string getCudaConfigureFuncName() const;

/// \name Code completion
//@{
/// Describes the context in which code completion occurs.
enum ParserCompletionContext {
  /// Code completion occurs at top-level or namespace context.
  PCC_Namespace,
  /// Code completion occurs within a class, struct, or union.
  PCC_Class,
  /// Code completion occurs within an Objective-C interface, protocol,
  /// or category.
  PCC_ObjCInterface,
  /// Code completion occurs within an Objective-C implementation or
  /// category implementation
  PCC_ObjCImplementation,
  /// Code completion occurs within the list of instance variables
  /// in an Objective-C interface, protocol, category, or implementation.
  PCC_ObjCInstanceVariableList,
  /// Code completion occurs following one or more template
  /// headers.
  PCC_Template,
  /// Code completion occurs following one or more template
  /// headers within a class.
  PCC_MemberTemplate,
  /// Code completion occurs within an expression.
  PCC_Expression,
  /// Code completion occurs within a statement, which may
  /// also be an expression or a declaration.
  PCC_Statement,
  /// Code completion occurs at the beginning of the
  /// initialization statement (or expression) in a for loop.
  PCC_ForInit,
  /// Code completion occurs within the condition of an if,
  /// while, switch, or for statement.
  PCC_Condition,
  /// Code completion occurs within the body of a function on a
  /// recovery path, where we do not have a specific handle on our position
  /// in the grammar.
  PCC_RecoveryInFunction,
  /// Code completion occurs where only a type is permitted.
  PCC_Type,
  /// Code completion occurs in a parenthesized expression, which
  /// might also be a type cast.
  PCC_ParenthesizedExpression,
  /// Code completion occurs within a sequence of declaration
  /// specifiers within a function, method, or block.
  PCC_LocalDeclarationSpecifiers
};

void CodeCompleteModuleImport(SourceLocation ImportLoc, ModuleIdPath Path);
void CodeCompleteOrdinaryName(Scope *S,
                              ParserCompletionContext CompletionContext);
void CodeCompleteDeclSpec(Scope *S, DeclSpec &DS,
                          bool AllowNonIdentifiers,
                          bool AllowNestedNameSpecifiers);

struct CodeCompleteExpressionData;
void CodeCompleteExpression(Scope *S,
                            const CodeCompleteExpressionData &Data);
void CodeCompleteExpression(Scope *S, QualType PreferredType,
                            bool IsParenthesized = false);
void CodeCompleteMemberReferenceExpr(Scope *S, Expr *Base, Expr *OtherOpBase,
                                     SourceLocation OpLoc, bool IsArrow,
                                     bool IsBaseExprStatement,
                                     QualType PreferredType);
void CodeCompletePostfixExpression(Scope *S, ExprResult LHS,
                                   QualType PreferredType);
void CodeCompleteTag(Scope *S, unsigned TagSpec);
void CodeCompleteTypeQualifiers(DeclSpec &DS);
void CodeCompleteFunctionQualifiers(DeclSpec &DS, Declarator &D,
                                    const VirtSpecifiers *VS = nullptr);
void CodeCompleteBracketDeclarator(Scope *S);
void CodeCompleteCase(Scope *S);
/// Determines the preferred type of the current function argument, by
/// examining the signatures of all possible overloads.
/// Returns null if unknown or ambiguous, or if code completion is off.
///
/// If the code completion point has been reached, also reports the function
/// signatures that were considered.
///
/// FIXME: rename to GuessCallArgumentType to reduce confusion.
QualType ProduceCallSignatureHelp(Scope *S, Expr *Fn, ArrayRef<Expr *> Args,
                                  SourceLocation OpenParLoc);
QualType ProduceConstructorSignatureHelp(Scope *S, QualType Type,
                                         SourceLocation Loc,
                                         ArrayRef<Expr *> Args,
                                         SourceLocation OpenParLoc);
QualType ProduceCtorInitMemberSignatureHelp(Scope *S, Decl *ConstructorDecl,
                                            CXXScopeSpec SS,
                                            ParsedType TemplateTypeTy,
                                            ArrayRef<Expr *> ArgExprs,
                                            IdentifierInfo *II,
                                            SourceLocation OpenParLoc);
void CodeCompleteInitializer(Scope *S, Decl *D);
/// Trigger code completion for a record of \p BaseType. \p InitExprs are
/// expressions in the initializer list seen so far and \p D is the current
/// Designation being parsed.
void CodeCompleteDesignator(const QualType BaseType,
                            llvm::ArrayRef<Expr *> InitExprs,
                            const Designation &D);
void CodeCompleteAfterIf(Scope *S, bool IsBracedThen);

void CodeCompleteQualifiedId(Scope *S, CXXScopeSpec &SS, bool EnteringContext,
                             bool IsUsingDeclaration, QualType BaseType,
                             QualType PreferredType);
void CodeCompleteUsing(Scope *S);
void CodeCompleteUsingDirective(Scope *S);
void CodeCompleteNamespaceDecl(Scope *S);
void CodeCompleteNamespaceAliasDecl(Scope *S);
void CodeCompleteOperatorName(Scope *S);
void CodeCompleteConstructorInitializer(
                              Decl *Constructor,
                              ArrayRef<CXXCtorInitializer *> Initializers);

void CodeCompleteLambdaIntroducer(Scope *S, LambdaIntroducer &Intro,
                                  bool AfterAmpersand);
void CodeCompleteAfterFunctionEquals(Declarator &D);

void CodeCompleteObjCAtDirective(Scope *S);
void CodeCompleteObjCAtVisibility(Scope *S);
void CodeCompleteObjCAtStatement(Scope *S);
void CodeCompleteObjCAtExpression(Scope *S);
void CodeCompleteObjCPropertyFlags(Scope *S, ObjCDeclSpec &ODS);
void CodeCompleteObjCPropertyGetter(Scope *S);
void CodeCompleteObjCPropertySetter(Scope *S);
void CodeCompleteObjCPassingType(Scope *S, ObjCDeclSpec &DS,
                                 bool IsParameter);
void CodeCompleteObjCMessageReceiver(Scope *S);
void CodeCompleteObjCSuperMessage(Scope *S, SourceLocation SuperLoc,
                                  ArrayRef<IdentifierInfo *> SelIdents,
                                  bool AtArgumentExpression);
void CodeCompleteObjCClassMessage(Scope *S, ParsedType Receiver,
                                  ArrayRef<IdentifierInfo *> SelIdents,
                                  bool AtArgumentExpression,
                                  bool IsSuper = false);
void CodeCompleteObjCInstanceMessage(Scope *S, Expr *Receiver,
                                     ArrayRef<IdentifierInfo *> SelIdents,
                                     bool AtArgumentExpression,
                                     ObjCInterfaceDecl *Super = nullptr);
void CodeCompleteObjCForCollection(Scope *S,
                                   DeclGroupPtrTy IterationVar);
void CodeCompleteObjCSelector(Scope *S,
                              ArrayRef<IdentifierInfo *> SelIdents);
void CodeCompleteObjCProtocolReferences(
                                       ArrayRef<IdentifierLocPair> Protocols);
void CodeCompleteObjCProtocolDecl(Scope *S);
void CodeCompleteObjCInterfaceDecl(Scope *S);
void CodeCompleteObjCSuperclass(Scope *S,
                                IdentifierInfo *ClassName,
                                SourceLocation ClassNameLoc);
void CodeCompleteObjCImplementationDecl(Scope *S);
void CodeCompleteObjCInterfaceCategory(Scope *S,
                                       IdentifierInfo *ClassName,
                                       SourceLocation ClassNameLoc);
void CodeCompleteObjCImplementationCategory(Scope *S,
                                            IdentifierInfo *ClassName,
                                            SourceLocation ClassNameLoc);
void CodeCompleteObjCPropertyDefinition(Scope *S);
void CodeCompleteObjCPropertySynthesizeIvar(Scope *S,
                                            IdentifierInfo *PropertyName);
void CodeCompleteObjCMethodDecl(Scope *S, Optional<bool> IsInstanceMethod,
                                ParsedType ReturnType);
void CodeCompleteObjCMethodDeclSelector(Scope *S,
                                        bool IsInstanceMethod,
                                        bool AtParameterName,
                                        ParsedType ReturnType,
                                        ArrayRef<IdentifierInfo *> SelIdents);
void CodeCompleteObjCClassPropertyRefExpr(Scope *S, IdentifierInfo &ClassName,
                                          SourceLocation ClassNameLoc,
                                          bool IsBaseExprStatement);
void CodeCompletePreprocessorDirective(bool InConditional);
void CodeCompleteInPreprocessorConditionalExclusion(Scope *S);
void CodeCompletePreprocessorMacroName(bool IsDefinition);
void CodeCompletePreprocessorExpression();
void CodeCompletePreprocessorMacroArgument(Scope *S,
                                           IdentifierInfo *Macro,
                                           MacroInfo *MacroInfo,
                                           unsigned Argument);
void CodeCompleteIncludedFile(llvm::StringRef Dir, bool IsAngled);
void CodeCompleteNaturalLanguage();
void CodeCompleteAvailabilityPlatformName();
void GatherGlobalCodeCompletions(CodeCompletionAllocator &Allocator,
                                 CodeCompletionTUInfo &CCTUInfo,
                SmallVectorImpl<CodeCompletionResult> &Results);
//@}

//===--------------------------------------------------------------------===//
// Extra semantic analysis beyond the C type system

12493public:
SourceLocation getLocationOfStringLiteralByte(const StringLiteral *SL,
                                              unsigned ByteNo) const;

12497private:
void CheckArrayAccess(const Expr *BaseExpr, const Expr *IndexExpr,
                      const ArraySubscriptExpr *ASE=nullptr,
                      bool AllowOnePastEnd=true, bool IndexNegated=false);
void CheckArrayAccess(const Expr *E);
// Used to grab the relevant information from a FormatAttr and a
// FunctionDeclaration.
struct FormatStringInfo {
  unsigned FormatIdx;
  unsigned FirstDataArg;
  bool HasVAListArg;
};

static bool getFormatStringInfo(const FormatAttr *Format, bool IsCXXMember,
                                FormatStringInfo *FSI);
bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
                       const FunctionProtoType *Proto);
bool CheckObjCMethodCall(ObjCMethodDecl *Method, SourceLocation loc,
                         ArrayRef<const Expr *> Args);
bool CheckPointerCall(NamedDecl *NDecl, CallExpr *TheCall,
                      const FunctionProtoType *Proto);
bool CheckOtherCall(CallExpr *TheCall, const FunctionProtoType *Proto);
void CheckConstructorCall(FunctionDecl *FDecl, QualType ThisType,
                          ArrayRef<const Expr *> Args,
                          const FunctionProtoType *Proto, SourceLocation Loc);

void CheckArgAlignment(SourceLocation Loc, NamedDecl *FDecl,
                       StringRef ParamName, QualType ArgTy, QualType ParamTy);

void checkCall(NamedDecl *FDecl, const FunctionProtoType *Proto,
               const Expr *ThisArg, ArrayRef<const Expr *> Args,
               bool IsMemberFunction, SourceLocation Loc, SourceRange Range,
               VariadicCallType CallType);

bool CheckObjCString(Expr *Arg);
ExprResult CheckOSLogFormatStringArg(Expr *Arg);

ExprResult CheckBuiltinFunctionCall(FunctionDecl *FDecl,
                                    unsigned BuiltinID, CallExpr *TheCall);

bool CheckTSBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                CallExpr *TheCall);

void checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, CallExpr *TheCall);

bool CheckARMBuiltinExclusiveCall(unsigned BuiltinID, CallExpr *TheCall,
                                  unsigned MaxWidth);
bool CheckNeonBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                  CallExpr *TheCall);
bool CheckMVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckSVEBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckCDEBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckARMCoprocessorImmediate(const TargetInfo &TI, const Expr *CoprocArg,
                                  bool WantCDE);
bool CheckARMBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);

bool CheckAArch64BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                     CallExpr *TheCall);
bool CheckBPFBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckHexagonBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckHexagonBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);
bool CheckMipsBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                  CallExpr *TheCall);
bool CheckMipsBuiltinCpu(const TargetInfo &TI, unsigned BuiltinID,
                         CallExpr *TheCall);
bool CheckMipsBuiltinArgument(unsigned BuiltinID, CallExpr *TheCall);
bool CheckSystemZBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinRoundingOrSAE(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinGatherScatterScale(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinTileArguments(unsigned BuiltinID, CallExpr *TheCall);
bool CheckX86BuiltinTileArgumentsRange(CallExpr *TheCall,
                                       ArrayRef<int> ArgNums);
bool CheckX86BuiltinTileDuplicate(CallExpr *TheCall, ArrayRef<int> ArgNums);
bool CheckX86BuiltinTileRangeAndDuplicate(CallExpr *TheCall,
                                          ArrayRef<int> ArgNums);
bool CheckX86BuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckPPCBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                 CallExpr *TheCall);
bool CheckAMDGCNBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
bool CheckRISCVLMUL(CallExpr *TheCall, unsigned ArgNum);
bool CheckRISCVBuiltinFunctionCall(const TargetInfo &TI, unsigned BuiltinID,
                                   CallExpr *TheCall);

bool SemaBuiltinVAStart(unsigned BuiltinID, CallExpr *TheCall);
bool SemaBuiltinVAStartARMMicrosoft(CallExpr *Call);
bool SemaBuiltinUnorderedCompare(CallExpr *TheCall);
bool SemaBuiltinFPClassification(CallExpr *TheCall, unsigned NumArgs);
bool SemaBuiltinComplex(CallExpr *TheCall);
bool SemaBuiltinVSX(CallExpr *TheCall);
bool SemaBuiltinOSLogFormat(CallExpr *TheCall);
bool SemaValueIsRunOfOnes(CallExpr *TheCall, unsigned ArgNum);

12592public:
// Used by C++ template instantiation.
ExprResult SemaBuiltinShuffleVector(CallExpr *TheCall);
ExprResult SemaConvertVectorExpr(Expr *E, TypeSourceInfo *TInfo,
                                 SourceLocation BuiltinLoc,
                                 SourceLocation RParenLoc);

12599private:
bool SemaBuiltinPrefetch(CallExpr *TheCall);
bool SemaBuiltinAllocaWithAlign(CallExpr *TheCall);
bool SemaBuiltinArithmeticFence(CallExpr *TheCall);
bool SemaBuiltinAssume(CallExpr *TheCall);
bool SemaBuiltinAssumeAligned(CallExpr *TheCall);
bool SemaBuiltinLongjmp(CallExpr *TheCall);
bool SemaBuiltinSetjmp(CallExpr *TheCall);
ExprResult SemaBuiltinAtomicOverloaded(ExprResult TheCallResult);
ExprResult SemaBuiltinNontemporalOverloaded(ExprResult TheCallResult);
ExprResult SemaAtomicOpsOverloaded(ExprResult TheCallResult,
                                   AtomicExpr::AtomicOp Op);
ExprResult SemaBuiltinOperatorNewDeleteOverloaded(ExprResult TheCallResult,
                                                  bool IsDelete);
bool SemaBuiltinConstantArg(CallExpr *TheCall, int ArgNum,
                            llvm::APSInt &Result);
bool SemaBuiltinConstantArgRange(CallExpr *TheCall, int ArgNum, int Low,
                                 int High, bool RangeIsError = true);
bool SemaBuiltinConstantArgMultiple(CallExpr *TheCall, int ArgNum,
                                    unsigned Multiple);
bool SemaBuiltinConstantArgPower2(CallExpr *TheCall, int ArgNum);
bool SemaBuiltinConstantArgShiftedByte(CallExpr *TheCall, int ArgNum,
                                       unsigned ArgBits);
bool SemaBuiltinConstantArgShiftedByteOrXXFF(CallExpr *TheCall, int ArgNum,
                                             unsigned ArgBits);
bool SemaBuiltinARMSpecialReg(unsigned BuiltinID, CallExpr *TheCall,
                              int ArgNum, unsigned ExpectedFieldNum,
                              bool AllowName);
bool SemaBuiltinARMMemoryTaggingCall(unsigned BuiltinID, CallExpr *TheCall);
bool SemaBuiltinPPCMMACall(CallExpr *TheCall, const char *TypeDesc);

bool CheckPPCMMAType(QualType Type, SourceLocation TypeLoc);

// Matrix builtin handling.
ExprResult SemaBuiltinMatrixTranspose(CallExpr *TheCall,
                                      ExprResult CallResult);
ExprResult SemaBuiltinMatrixColumnMajorLoad(CallExpr *TheCall,
                                            ExprResult CallResult);
ExprResult SemaBuiltinMatrixColumnMajorStore(CallExpr *TheCall,
                                             ExprResult CallResult);

12640public:
enum FormatStringType {
  FST_Scanf,
  FST_Printf,
  FST_NSString,
  FST_Strftime,
  FST_Strfmon,
  FST_Kprintf,
  FST_FreeBSDKPrintf,
  FST_OSTrace,
  FST_OSLog,
  FST_Syslog,
  FST_Unknown
};
static FormatStringType GetFormatStringType(const FormatAttr *Format);

bool FormatStringHasSArg(const StringLiteral *FExpr);

static bool GetFormatNSStringIdx(const FormatAttr *Format, unsigned &Idx);

12660private:
bool CheckFormatArguments(const FormatAttr *Format,
                          ArrayRef<const Expr *> Args,
                          bool IsCXXMember,
                          VariadicCallType CallType,
                          SourceLocation Loc, SourceRange Range,
                          llvm::SmallBitVector &CheckedVarArgs);
bool CheckFormatArguments(ArrayRef<const Expr *> Args,
                          bool HasVAListArg, unsigned format_idx,
                          unsigned firstDataArg, FormatStringType Type,
                          VariadicCallType CallType,
                          SourceLocation Loc, SourceRange range,
                          llvm::SmallBitVector &CheckedVarArgs);

void CheckAbsoluteValueFunction(const CallExpr *Call,
                                const FunctionDecl *FDecl);

void CheckMaxUnsignedZero(const CallExpr *Call, const FunctionDecl *FDecl);

void CheckMemaccessArguments(const CallExpr *Call,
                             unsigned BId,
                             IdentifierInfo *FnName);

void CheckStrlcpycatArguments(const CallExpr *Call,
                              IdentifierInfo *FnName);

void CheckStrncatArguments(const CallExpr *Call,
                           IdentifierInfo *FnName);

void CheckFreeArguments(const CallExpr *E);

void CheckReturnValExpr(Expr *RetValExp, QualType lhsType,
                        SourceLocation ReturnLoc,
                        bool isObjCMethod = false,
                        const AttrVec *Attrs = nullptr,
                        const FunctionDecl *FD = nullptr);

12697public:
void CheckFloatComparison(SourceLocation Loc, Expr *LHS, Expr *RHS);

12700private:
void CheckImplicitConversions(Expr *E, SourceLocation CC = SourceLocation());
void CheckBoolLikeConversion(Expr *E, SourceLocation CC);
void CheckForIntOverflow(Expr *E);
void CheckUnsequencedOperations(const Expr *E);

/// Perform semantic checks on a completed expression. This will either
/// be a full-expression or a default argument expression.
void CheckCompletedExpr(Expr *E, SourceLocation CheckLoc = SourceLocation(),
                        bool IsConstexpr = false);

void CheckBitFieldInitialization(SourceLocation InitLoc, FieldDecl *Field,
                                 Expr *Init);

/// Check if there is a field shadowing.
void CheckShadowInheritedFields(const SourceLocation &Loc,
                                DeclarationName FieldName,
                                const CXXRecordDecl *RD,
                                bool DeclIsField = true);

/// Check if the given expression contains 'break' or 'continue'
/// statement that produces control flow different from GCC.
void CheckBreakContinueBinding(Expr *E);

/// Check whether receiver is mutable ObjC container which
/// attempts to add itself into the container
void CheckObjCCircularContainer(ObjCMessageExpr *Message);

void CheckTCBEnforcement(const CallExpr *TheCall, const FunctionDecl *Callee);

void AnalyzeDeleteExprMismatch(const CXXDeleteExpr *DE);
void AnalyzeDeleteExprMismatch(FieldDecl *Field, SourceLocation DeleteLoc,
                               bool DeleteWasArrayForm);
12733public:
/// Register a magic integral constant to be used as a type tag.
void RegisterTypeTagForDatatype(const IdentifierInfo *ArgumentKind,
                                uint64_t MagicValue, QualType Type,
                                bool LayoutCompatible, bool MustBeNull);

struct TypeTagData {
  TypeTagData() {}

  TypeTagData(QualType Type, bool LayoutCompatible, bool MustBeNull) :
      Type(Type), LayoutCompatible(LayoutCompatible),
      MustBeNull(MustBeNull)
  {}

  QualType Type;

  /// If true, \c Type should be compared with other expression's types for
  /// layout-compatibility.
  unsigned LayoutCompatible : 1;
  unsigned MustBeNull : 1;
};

/// A pair of ArgumentKind identifier and magic value.  This uniquely
/// identifies the magic value.
typedef std::pair<const IdentifierInfo *, uint64_t> TypeTagMagicValue;

12759private:
/// A map from magic value to type information.
std::unique_ptr<llvm::DenseMap<TypeTagMagicValue, TypeTagData>>
    TypeTagForDatatypeMagicValues;

/// Peform checks on a call of a function with argument_with_type_tag
/// or pointer_with_type_tag attributes.
void CheckArgumentWithTypeTag(const ArgumentWithTypeTagAttr *Attr,
                              const ArrayRef<const Expr *> ExprArgs,
                              SourceLocation CallSiteLoc);

/// Check if we are taking the address of a packed field
/// as this may be a problem if the pointer value is dereferenced.
void CheckAddressOfPackedMember(Expr *rhs);

/// The parser's current scope.
///
/// The parser maintains this state here.
Scope *CurScope;

mutable IdentifierInfo *Ident_super;
mutable IdentifierInfo *Ident___float128;

/// Nullability type specifiers.
IdentifierInfo *Ident__Nonnull = nullptr;
IdentifierInfo *Ident__Nullable = nullptr;
IdentifierInfo *Ident__Nullable_result = nullptr;
IdentifierInfo *Ident__Null_unspecified = nullptr;

IdentifierInfo *Ident_NSError = nullptr;

/// The handler for the FileChanged preprocessor events.
///
/// Used for diagnostics that implement custom semantic analysis for #include
/// directives, like -Wpragma-pack.
sema::SemaPPCallbacks *SemaPPCallbackHandler;

12796protected:
friend class Parser;
friend class InitializationSequence;
friend class ASTReader;
friend class ASTDeclReader;
friend class ASTWriter;

12803public:
/// Retrieve the keyword associated
IdentifierInfo *getNullabilityKeyword(NullabilityKind nullability);

/// The struct behind the CFErrorRef pointer.
RecordDecl *CFError = nullptr;
bool isCFError(RecordDecl *D);

/// Retrieve the identifier "NSError".
IdentifierInfo *getNSErrorIdent();

/// Retrieve the parser's current scope.
///
/// This routine must only be used when it is certain that semantic analysis
/// and the parser are in precisely the same context, which is not the case
/// when, e.g., we are performing any kind of template instantiation.
/// Therefore, the only safe places to use this scope are in the parser
/// itself and in routines directly invoked from the parser and *never* from
/// template substitution or instantiation.
Scope *getCurScope() const { return CurScope; }

void incrementMSManglingNumber() const {
  return CurScope->incrementMSManglingNumber();
}

IdentifierInfo *getSuperIdentifier() const;
IdentifierInfo *getFloat128Identifier() const;

Decl *getObjCDeclContext() const;

DeclContext *getCurLexicalContext() const {
  return OriginalLexicalContext ? OriginalLexicalContext : CurContext;
}

const DeclContext *getCurObjCLexicalContext() const {
  const DeclContext *DC = getCurLexicalContext();
  // A category implicitly has the attribute of the interface.
  if (const ObjCCategoryDecl *CatD = dyn_cast<ObjCCategoryDecl>(DC))
    DC = CatD->getClassInterface();
  return DC;
}

/// Determine the number of levels of enclosing template parameters. This is
/// only usable while parsing. Note that this does not include dependent
/// contexts in which no template parameters have yet been declared, such as
/// in a terse function template or generic lambda before the first 'auto' is
/// encountered.
unsigned getTemplateDepth(Scope *S) const;

/// To be used for checking whether the arguments being passed to
/// function exceeds the number of parameters expected for it.
static bool TooManyArguments(size_t NumParams, size_t NumArgs,
                             bool PartialOverloading = false) {
  // We check whether we're just after a comma in code-completion.
  if (NumArgs > 0 && PartialOverloading)
    return NumArgs + 1 > NumParams; // If so, we view as an extra argument.
  return NumArgs > NumParams;
}

// Emitting members of dllexported classes is delayed until the class
// (including field initializers) is fully parsed.
SmallVector<CXXRecordDecl*, 4> DelayedDllExportClasses;
SmallVector<CXXMethodDecl*, 4> DelayedDllExportMemberFunctions;

12867private:
int ParsingClassDepth = 0;

class SavePendingParsedClassStateRAII {
public:
  SavePendingParsedClassStateRAII(Sema &S) : S(S) { swapSavedState(); }

  ~SavePendingParsedClassStateRAII() {
    assert(S.DelayedOverridingExceptionSpecChecks.empty() &&((void)0)
           "there shouldn't be any pending delayed exception spec checks")((void)0);
    assert(S.DelayedEquivalentExceptionSpecChecks.empty() &&((void)0)
           "there shouldn't be any pending delayed exception spec checks")((void)0);
    swapSavedState();
  }

private:
  Sema &S;
  decltype(DelayedOverridingExceptionSpecChecks)
      SavedOverridingExceptionSpecChecks;
  decltype(DelayedEquivalentExceptionSpecChecks)
      SavedEquivalentExceptionSpecChecks;

  void swapSavedState() {
    SavedOverridingExceptionSpecChecks.swap(
        S.DelayedOverridingExceptionSpecChecks);
    SavedEquivalentExceptionSpecChecks.swap(
        S.DelayedEquivalentExceptionSpecChecks);
  }
};

/// Helper class that collects misaligned member designations and
/// their location info for delayed diagnostics.
struct MisalignedMember {
  Expr *E;
  RecordDecl *RD;
  ValueDecl *MD;
  CharUnits Alignment;

  MisalignedMember() : E(), RD(), MD(), Alignment() {}
  MisalignedMember(Expr *E, RecordDecl *RD, ValueDecl *MD,
                   CharUnits Alignment)
      : E(E), RD(RD), MD(MD), Alignment(Alignment) {}
  explicit MisalignedMember(Expr *E)
      : MisalignedMember(E, nullptr, nullptr, CharUnits()) {}

  bool operator==(const MisalignedMember &m) { return this->E == m.E; }
};
/// Small set of gathered accesses to potentially misaligned members
/// due to the packed attribute.
SmallVector<MisalignedMember, 4> MisalignedMembers;

/// Adds an expression to the set of gathered misaligned members.
void AddPotentialMisalignedMembers(Expr *E, RecordDecl *RD, ValueDecl *MD,
                                   CharUnits Alignment);

12922public:
/// Diagnoses the current set of gathered accesses. This typically
/// happens at full expression level. The set is cleared after emitting the
/// diagnostics.
void DiagnoseMisalignedMembers();

/// This function checks if the expression is in the sef of potentially
/// misaligned members and it is converted to some pointer type T with lower
/// or equal alignment requirements. If so it removes it. This is used when
/// we do not want to diagnose such misaligned access (e.g. in conversions to
/// void*).
void DiscardMisalignedMemberAddress(const Type *T, Expr *E);

/// This function calls Action when it determines that E designates a
/// misaligned member due to the packed attribute. This is used to emit
/// local diagnostics like in reference binding.
void RefersToMemberWithReducedAlignment(
    Expr *E,
    llvm::function_ref<void(Expr *, RecordDecl *, FieldDecl *, CharUnits)>
        Action);

/// Describes the reason a calling convention specification was ignored, used
/// for diagnostics.
enum class CallingConventionIgnoredReason {
  ForThisTarget = 0,
  VariadicFunction,
  ConstructorDestructor,
  BuiltinFunction
};
/// Creates a SemaDiagnosticBuilder that emits the diagnostic if the current
/// context is "used as device code".
///
/// - If CurLexicalContext is a kernel function or it is known that the
///   function will be emitted for the device, emits the diagnostics
///   immediately.
/// - If CurLexicalContext is a function and we are compiling
///   for the device, but we don't know that this function will be codegen'ed
///   for devive yet, creates a diagnostic which is emitted if and when we
///   realize that the function will be codegen'ed.
///
/// Example usage:
///
/// Diagnose __float128 type usage only from SYCL device code if the current
/// target doesn't support it
/// if (!S.Context.getTargetInfo().hasFloat128Type() &&
///     S.getLangOpts().SYCLIsDevice)
///   SYCLDiagIfDeviceCode(Loc, diag::err_type_unsupported) << "__float128";
SemaDiagnosticBuilder SYCLDiagIfDeviceCode(SourceLocation Loc,
                                           unsigned DiagID);

/// Check whether we're allowed to call Callee from the current context.
///
/// - If the call is never allowed in a semantically-correct program
///   emits an error and returns false.
///
/// - If the call is allowed in semantically-correct programs, but only if
///   it's never codegen'ed, creates a deferred diagnostic to be emitted if
///   and when the caller is codegen'ed, and returns true.
///
/// - Otherwise, returns true without emitting any diagnostics.
///
/// Adds Callee to DeviceCallGraph if we don't know if its caller will be
/// codegen'ed yet.
bool checkSYCLDeviceFunction(SourceLocation Loc, FunctionDecl *Callee);
12986};

12988/// RAII object that enters a new expression evaluation context.
12989class EnterExpressionEvaluationContext {
Sema &Actions;
bool Entered = true;

12993public:
EnterExpressionEvaluationContext(
    Sema &Actions, Sema::ExpressionEvaluationContext NewContext,
    Decl *LambdaContextDecl = nullptr,
    Sema::ExpressionEvaluationContextRecord::ExpressionKind ExprContext =
        Sema::ExpressionEvaluationContextRecord::EK_Other,
    bool ShouldEnter = true)
    : Actions(Actions), Entered(ShouldEnter) {
  if (Entered)
    Actions.PushExpressionEvaluationContext(NewContext, LambdaContextDecl,
                                            ExprContext);
}
EnterExpressionEvaluationContext(
    Sema &Actions, Sema::ExpressionEvaluationContext NewContext,
    Sema::ReuseLambdaContextDecl_t,
    Sema::ExpressionEvaluationContextRecord::ExpressionKind ExprContext =
        Sema::ExpressionEvaluationContextRecord::EK_Other)
    : Actions(Actions) {
  Actions.PushExpressionEvaluationContext(
      NewContext, Sema::ReuseLambdaContextDecl, ExprContext);
}

enum InitListTag { InitList };
EnterExpressionEvaluationContext(Sema &Actions, InitListTag,
                                 bool ShouldEnter = true)
    : Actions(Actions), Entered(false) {
  // In C++11 onwards, narrowing checks are performed on the contents of
  // braced-init-lists, even when they occur within unevaluated operands.
  // Therefore we still need to instantiate constexpr functions used in such
  // a context.
  if (ShouldEnter && Actions.isUnevaluatedContext() &&
      Actions.getLangOpts().CPlusPlus11) {
    Actions.PushExpressionEvaluationContext(
        Sema::ExpressionEvaluationContext::UnevaluatedList);
    Entered = true;
  }
}

~EnterExpressionEvaluationContext() {
  if (Entered)
    Actions.PopExpressionEvaluationContext();
}
13035};

13037DeductionFailureInfo
13038MakeDeductionFailureInfo(ASTContext &Context, Sema::TemplateDeductionResult TDK,
                       sema::TemplateDeductionInfo &Info);

13041/// Contains a late templated function.
13042/// Will be parsed at the end of the translation unit, used by Sema & Parser.
13043struct LateParsedTemplate {
CachedTokens Toks;
/// The template function declaration to be late parsed.
Decl *D;
13047};

13049template <>
13050void Sema::PragmaStack<Sema::AlignPackInfo>::Act(SourceLocation PragmaLocation,
                                               PragmaMsStackAction Action,
                                               llvm::StringRef StackSlotLabel,
                                               AlignPackInfo Value);

13055} // end namespace clang

13057namespace llvm {
13058// Hash a FunctionDeclAndLoc by looking at both its FunctionDecl and its
13059// SourceLocation.
13060template <> struct DenseMapInfo<clang::Sema::FunctionDeclAndLoc> {
using FunctionDeclAndLoc = clang::Sema::FunctionDeclAndLoc;
using FDBaseInfo = DenseMapInfo<clang::CanonicalDeclPtr<clang::FunctionDecl>>;

static FunctionDeclAndLoc getEmptyKey() {
  return {FDBaseInfo::getEmptyKey(), clang::SourceLocation()};
}

static FunctionDeclAndLoc getTombstoneKey() {
  return {FDBaseInfo::getTombstoneKey(), clang::SourceLocation()};
}

static unsigned getHashValue(const FunctionDeclAndLoc &FDL) {
  return hash_combine(FDBaseInfo::getHashValue(FDL.FD),
                      FDL.Loc.getHashValue());
}

static bool isEqual(const FunctionDeclAndLoc &LHS,
                    const FunctionDeclAndLoc &RHS) {
  return LHS.FD == RHS.FD && LHS.Loc == RHS.Loc;
}
13081};
13082} // namespace llvm

13084#endif