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

Bug Summary

File:	src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaDecl.cpp
Warning:	line 9892, column 19 Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

Show analyzer invocation

clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaDecl.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/SemaDecl.cpp

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

→

1//===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
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 implements semantic analysis for declarations.
10//
11//===----------------------------------------------------------------------===//

13#include "TypeLocBuilder.h"
14#include "clang/AST/ASTConsumer.h"
15#include "clang/AST/ASTContext.h"
16#include "clang/AST/ASTLambda.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/CommentDiagnostic.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/DeclTemplate.h"
23#include "clang/AST/EvaluatedExprVisitor.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/NonTrivialTypeVisitor.h"
27#include "clang/AST/StmtCXX.h"
28#include "clang/Basic/Builtins.h"
29#include "clang/Basic/PartialDiagnostic.h"
30#include "clang/Basic/SourceManager.h"
31#include "clang/Basic/TargetInfo.h"
32#include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex
33#include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
34#include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex
35#include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled()
36#include "clang/Sema/CXXFieldCollector.h"
37#include "clang/Sema/DeclSpec.h"
38#include "clang/Sema/DelayedDiagnostic.h"
39#include "clang/Sema/Initialization.h"
40#include "clang/Sema/Lookup.h"
41#include "clang/Sema/ParsedTemplate.h"
42#include "clang/Sema/Scope.h"
43#include "clang/Sema/ScopeInfo.h"
44#include "clang/Sema/SemaInternal.h"
45#include "clang/Sema/Template.h"
46#include "llvm/ADT/SmallString.h"
47#include "llvm/ADT/Triple.h"
48#include <algorithm>
49#include <cstring>
50#include <functional>
51#include <unordered_map>

53using namespace clang;
54using namespace sema;

56Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) {
if (OwnedType) {
  Decl *Group[2] = { OwnedType, Ptr };
  return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, Group, 2));
}

return DeclGroupPtrTy::make(DeclGroupRef(Ptr));
63}

65namespace {

67class TypeNameValidatorCCC final : public CorrectionCandidateCallback {
public:
 TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false,
                      bool AllowTemplates = false,
                      bool AllowNonTemplates = true)
     : AllowInvalidDecl(AllowInvalid), WantClassName(WantClass),
       AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) {
   WantExpressionKeywords = false;
   WantCXXNamedCasts = false;
   WantRemainingKeywords = false;
}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
    if (!AllowInvalidDecl && ND->isInvalidDecl())
      return false;

    if (getAsTypeTemplateDecl(ND))
      return AllowTemplates;

    bool IsType = isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
    if (!IsType)
      return false;

    if (AllowNonTemplates)
      return true;

    // An injected-class-name of a class template (specialization) is valid
    // as a template or as a non-template.
    if (AllowTemplates) {
      auto *RD = dyn_cast<CXXRecordDecl>(ND);
      if (!RD || !RD->isInjectedClassName())
        return false;
      RD = cast<CXXRecordDecl>(RD->getDeclContext());
      return RD->getDescribedClassTemplate() ||
             isa<ClassTemplateSpecializationDecl>(RD);
    }

    return false;
  }

  return !WantClassName && candidate.isKeyword();
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<TypeNameValidatorCCC>(*this);
}

private:
bool AllowInvalidDecl;
bool WantClassName;
bool AllowTemplates;
bool AllowNonTemplates;
120};

122} // end anonymous namespace

124/// Determine whether the token kind starts a simple-type-specifier.
125bool Sema::isSimpleTypeSpecifier(tok::TokenKind Kind) const {
switch (Kind) {
// FIXME: Take into account the current language when deciding whether a
// token kind is a valid type specifier
case tok::kw_short:
case tok::kw_long:
case tok::kw___int64:
case tok::kw___int128:
case tok::kw_signed:
case tok::kw_unsigned:
case tok::kw_void:
case tok::kw_char:
case tok::kw_int:
case tok::kw_half:
case tok::kw_float:
case tok::kw_double:
case tok::kw___bf16:
case tok::kw__Float16:
case tok::kw___float128:
case tok::kw_wchar_t:
case tok::kw_bool:
case tok::kw___underlying_type:
case tok::kw___auto_type:
  return true;

case tok::annot_typename:
case tok::kw_char16_t:
case tok::kw_char32_t:
case tok::kw_typeof:
case tok::annot_decltype:
case tok::kw_decltype:
  return getLangOpts().CPlusPlus;

case tok::kw_char8_t:
  return getLangOpts().Char8;

default:
  break;
}

return false;
166}

168namespace {
169enum class UnqualifiedTypeNameLookupResult {
NotFound,
FoundNonType,
FoundType
173};
174} // end anonymous namespace

176/// Tries to perform unqualified lookup of the type decls in bases for
177/// dependent class.
178/// \return \a NotFound if no any decls is found, \a FoundNotType if found not a
179/// type decl, \a FoundType if only type decls are found.
180static UnqualifiedTypeNameLookupResult
181lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II,
                              SourceLocation NameLoc,
                              const CXXRecordDecl *RD) {
if (!RD->hasDefinition())
  return UnqualifiedTypeNameLookupResult::NotFound;
// Look for type decls in base classes.
UnqualifiedTypeNameLookupResult FoundTypeDecl =
    UnqualifiedTypeNameLookupResult::NotFound;
for (const auto &Base : RD->bases()) {
  const CXXRecordDecl *BaseRD = nullptr;
  if (auto *BaseTT = Base.getType()->getAs<TagType>())
    BaseRD = BaseTT->getAsCXXRecordDecl();
  else if (auto *TST = Base.getType()->getAs<TemplateSpecializationType>()) {
    // Look for type decls in dependent base classes that have known primary
    // templates.
    if (!TST || !TST->isDependentType())
      continue;
    auto *TD = TST->getTemplateName().getAsTemplateDecl();
    if (!TD)
      continue;
    if (auto *BasePrimaryTemplate =
        dyn_cast_or_null<CXXRecordDecl>(TD->getTemplatedDecl())) {
      if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl())
        BaseRD = BasePrimaryTemplate;
      else if (auto *CTD = dyn_cast<ClassTemplateDecl>(TD)) {
        if (const ClassTemplatePartialSpecializationDecl *PS =
                CTD->findPartialSpecialization(Base.getType()))
          if (PS->getCanonicalDecl() != RD->getCanonicalDecl())
            BaseRD = PS;
      }
    }
  }
  if (BaseRD) {
    for (NamedDecl *ND : BaseRD->lookup(&II)) {
      if (!isa<TypeDecl>(ND))
        return UnqualifiedTypeNameLookupResult::FoundNonType;
      FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
    }
    if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) {
      switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, BaseRD)) {
      case UnqualifiedTypeNameLookupResult::FoundNonType:
        return UnqualifiedTypeNameLookupResult::FoundNonType;
      case UnqualifiedTypeNameLookupResult::FoundType:
        FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
        break;
      case UnqualifiedTypeNameLookupResult::NotFound:
        break;
      }
    }
  }
}

return FoundTypeDecl;
234}

236static ParsedType recoverFromTypeInKnownDependentBase(Sema &S,
                                                    const IdentifierInfo &II,
                                                    SourceLocation NameLoc) {
// Lookup in the parent class template context, if any.
const CXXRecordDecl *RD = nullptr;
UnqualifiedTypeNameLookupResult FoundTypeDecl =
    UnqualifiedTypeNameLookupResult::NotFound;
for (DeclContext *DC = S.CurContext;
     DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound;
     DC = DC->getParent()) {
  // Look for type decls in dependent base classes that have known primary
  // templates.
  RD = dyn_cast<CXXRecordDecl>(DC);
  if (RD && RD->getDescribedClassTemplate())
    FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD);
}
if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType)
  return nullptr;

// We found some types in dependent base classes.  Recover as if the user
// wrote 'typename MyClass::II' instead of 'II'.  We'll fully resolve the
// lookup during template instantiation.
S.Diag(NameLoc, diag::ext_found_in_dependent_base) << &II;

ASTContext &Context = S.Context;
auto *NNS = NestedNameSpecifier::Create(Context, nullptr, false,
                                        cast<Type>(Context.getRecordType(RD)));
QualType T = Context.getDependentNameType(ETK_Typename, NNS, &II);

CXXScopeSpec SS;
SS.MakeTrivial(Context, NNS, SourceRange(NameLoc));

TypeLocBuilder Builder;
DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
DepTL.setNameLoc(NameLoc);
DepTL.setElaboratedKeywordLoc(SourceLocation());
DepTL.setQualifierLoc(SS.getWithLocInContext(Context));
return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
274}

276/// If the identifier refers to a type name within this scope,
277/// return the declaration of that type.
278///
279/// This routine performs ordinary name lookup of the identifier II
280/// within the given scope, with optional C++ scope specifier SS, to
281/// determine whether the name refers to a type. If so, returns an
282/// opaque pointer (actually a QualType) corresponding to that
283/// type. Otherwise, returns NULL.
284ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
                           Scope *S, CXXScopeSpec *SS,
                           bool isClassName, bool HasTrailingDot,
                           ParsedType ObjectTypePtr,
                           bool IsCtorOrDtorName,
                           bool WantNontrivialTypeSourceInfo,
                           bool IsClassTemplateDeductionContext,
                           IdentifierInfo **CorrectedII) {
// FIXME: Consider allowing this outside C++1z mode as an extension.
bool AllowDeducedTemplate = IsClassTemplateDeductionContext &&
                            getLangOpts().CPlusPlus17 && !IsCtorOrDtorName &&
                            !isClassName && !HasTrailingDot;

// Determine where we will perform name lookup.
DeclContext *LookupCtx = nullptr;
if (ObjectTypePtr) {
  QualType ObjectType = ObjectTypePtr.get();
  if (ObjectType->isRecordType())
    LookupCtx = computeDeclContext(ObjectType);
} else if (SS && SS->isNotEmpty()) {
  LookupCtx = computeDeclContext(*SS, false);

  if (!LookupCtx) {
    if (isDependentScopeSpecifier(*SS)) {
      // C++ [temp.res]p3:
      //   A qualified-id that refers to a type and in which the
      //   nested-name-specifier depends on a template-parameter (14.6.2)
      //   shall be prefixed by the keyword typename to indicate that the
      //   qualified-id denotes a type, forming an
      //   elaborated-type-specifier (7.1.5.3).
      //
      // We therefore do not perform any name lookup if the result would
      // refer to a member of an unknown specialization.
      if (!isClassName && !IsCtorOrDtorName)
        return nullptr;

      // We know from the grammar that this name refers to a type,
      // so build a dependent node to describe the type.
      if (WantNontrivialTypeSourceInfo)
        return ActOnTypenameType(S, SourceLocation(), *SS, II, NameLoc).get();

      NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context);
      QualType T = CheckTypenameType(ETK_None, SourceLocation(), QualifierLoc,
                                     II, NameLoc);
      return ParsedType::make(T);
    }

    return nullptr;
  }

  if (!LookupCtx->isDependentContext() &&
      RequireCompleteDeclContext(*SS, LookupCtx))
    return nullptr;
}

// FIXME: LookupNestedNameSpecifierName isn't the right kind of
// lookup for class-names.
LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName :
                                    LookupOrdinaryName;
LookupResult Result(*this, &II, NameLoc, Kind);
if (LookupCtx) {
  // Perform "qualified" name lookup into the declaration context we
  // computed, which is either the type of the base of a member access
  // expression or the declaration context associated with a prior
  // nested-name-specifier.
  LookupQualifiedName(Result, LookupCtx);

  if (ObjectTypePtr && Result.empty()) {
    // 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 (possibly cv-qualified) T.
    LookupName(Result, S);
  }
} else {
  // Perform unqualified name lookup.
  LookupName(Result, S);

  // For unqualified lookup in a class template in MSVC mode, look into
  // dependent base classes where the primary class template is known.
  if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) {
    if (ParsedType TypeInBase =
            recoverFromTypeInKnownDependentBase(*this, II, NameLoc))
      return TypeInBase;
  }
}

NamedDecl *IIDecl = nullptr;
switch (Result.getResultKind()) {
case LookupResult::NotFound:
case LookupResult::NotFoundInCurrentInstantiation:
  if (CorrectedII) {
    TypeNameValidatorCCC CCC(/*AllowInvalid=*/true, isClassName,
                             AllowDeducedTemplate);
    TypoCorrection Correction = CorrectTypo(Result.getLookupNameInfo(), Kind,
                                            S, SS, CCC, CTK_ErrorRecovery);
    IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo();
    TemplateTy Template;
    bool MemberOfUnknownSpecialization;
    UnqualifiedId TemplateName;
    TemplateName.setIdentifier(NewII, NameLoc);
    NestedNameSpecifier *NNS = Correction.getCorrectionSpecifier();
    CXXScopeSpec NewSS, *NewSSPtr = SS;
    if (SS && NNS) {
      NewSS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
      NewSSPtr = &NewSS;
    }
    if (Correction && (NNS || NewII != &II) &&
        // Ignore a correction to a template type as the to-be-corrected
        // identifier is not a template (typo correction for template names
        // is handled elsewhere).
        !(getLangOpts().CPlusPlus && NewSSPtr &&
          isTemplateName(S, *NewSSPtr, false, TemplateName, nullptr, false,
                         Template, MemberOfUnknownSpecialization))) {
      ParsedType Ty = getTypeName(*NewII, NameLoc, S, NewSSPtr,
                                  isClassName, HasTrailingDot, ObjectTypePtr,
                                  IsCtorOrDtorName,
                                  WantNontrivialTypeSourceInfo,
                                  IsClassTemplateDeductionContext);
      if (Ty) {
        diagnoseTypo(Correction,
                     PDiag(diag::err_unknown_type_or_class_name_suggest)
                       << Result.getLookupName() << isClassName);
        if (SS && NNS)
          SS->MakeTrivial(Context, NNS, SourceRange(NameLoc));
        *CorrectedII = NewII;
        return Ty;
      }
    }
  }
  // If typo correction failed or was not performed, fall through
  LLVM_FALLTHROUGH[[gnu::fallthrough]];
case LookupResult::FoundOverloaded:
case LookupResult::FoundUnresolvedValue:
  Result.suppressDiagnostics();
  return nullptr;

case LookupResult::Ambiguous:
  // Recover from type-hiding ambiguities by hiding the type.  We'll
  // do the lookup again when looking for an object, and we can
  // diagnose the error then.  If we don't do this, then the error
  // about hiding the type will be immediately followed by an error
  // that only makes sense if the identifier was treated like a type.
  if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) {
    Result.suppressDiagnostics();
    return nullptr;
  }

  // Look to see if we have a type anywhere in the list of results.
  for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
       Res != ResEnd; ++Res) {
    NamedDecl *RealRes = (*Res)->getUnderlyingDecl();
    if (isa<TypeDecl, ObjCInterfaceDecl, UnresolvedUsingIfExistsDecl>(
            RealRes) ||
        (AllowDeducedTemplate && getAsTypeTemplateDecl(RealRes))) {
      if (!IIDecl ||
          // Make the selection of the recovery decl deterministic.
          RealRes->getLocation() < IIDecl->getLocation())
        IIDecl = RealRes;
    }
  }

  if (!IIDecl) {
    // None of the entities we found is a type, so there is no way
    // to even assume that the result is a type. In this case, don't
    // complain about the ambiguity. The parser will either try to
    // perform this lookup again (e.g., as an object name), which
    // will produce the ambiguity, or will complain that it expected
    // a type name.
    Result.suppressDiagnostics();
    return nullptr;
  }

  // We found a type within the ambiguous lookup; diagnose the
  // ambiguity and then return that type. This might be the right
  // answer, or it might not be, but it suppresses any attempt to
  // perform the name lookup again.
  break;

case LookupResult::Found:
  IIDecl = Result.getFoundDecl();
  break;
}

assert(IIDecl && "Didn't find decl")((void)0);

QualType T;
if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) {
  // C++ [class.qual]p2: A lookup that would find the injected-class-name
  // instead names the constructors of the class, except when naming a class.
  // This is ill-formed when we're not actually forming a ctor or dtor name.
  auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
  auto *FoundRD = dyn_cast<CXXRecordDecl>(TD);
  if (!isClassName && !IsCtorOrDtorName && LookupRD && FoundRD &&
      FoundRD->isInjectedClassName() &&
      declaresSameEntity(LookupRD, cast<Decl>(FoundRD->getParent())))
    Diag(NameLoc, diag::err_out_of_line_qualified_id_type_names_constructor)
        << &II << /*Type*/1;

  DiagnoseUseOfDecl(IIDecl, NameLoc);

  T = Context.getTypeDeclType(TD);
  MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
} else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) {
  (void)DiagnoseUseOfDecl(IDecl, NameLoc);
  if (!HasTrailingDot)
    T = Context.getObjCInterfaceType(IDecl);
} else if (auto *UD = dyn_cast<UnresolvedUsingIfExistsDecl>(IIDecl)) {
  (void)DiagnoseUseOfDecl(UD, NameLoc);
  // Recover with 'int'
  T = Context.IntTy;
} else if (AllowDeducedTemplate) {
  if (auto *TD = getAsTypeTemplateDecl(IIDecl))
    T = Context.getDeducedTemplateSpecializationType(TemplateName(TD),
                                                     QualType(), false);
}

if (T.isNull()) {
  // If it's not plausibly a type, suppress diagnostics.
  Result.suppressDiagnostics();
  return nullptr;
}

// NOTE: avoid constructing an ElaboratedType(Loc) if this is a
// constructor or destructor name (in such a case, the scope specifier
// will be attached to the enclosing Expr or Decl node).
if (SS && SS->isNotEmpty() && !IsCtorOrDtorName &&
    !isa<ObjCInterfaceDecl, UnresolvedUsingIfExistsDecl>(IIDecl)) {
  if (WantNontrivialTypeSourceInfo) {
    // Construct a type with type-source information.
    TypeLocBuilder Builder;
    Builder.pushTypeSpec(T).setNameLoc(NameLoc);

    T = getElaboratedType(ETK_None, *SS, T);
    ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
    ElabTL.setElaboratedKeywordLoc(SourceLocation());
    ElabTL.setQualifierLoc(SS->getWithLocInContext(Context));
    return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
  } else {
    T = getElaboratedType(ETK_None, *SS, T);
  }
}

return ParsedType::make(T);
530}

532// Builds a fake NNS for the given decl context.
533static NestedNameSpecifier *
534synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) {
for (;; DC = DC->getLookupParent()) {
  DC = DC->getPrimaryContext();
  auto *ND = dyn_cast<NamespaceDecl>(DC);
  if (ND && !ND->isInline() && !ND->isAnonymousNamespace())
    return NestedNameSpecifier::Create(Context, nullptr, ND);
  else if (auto *RD = dyn_cast<CXXRecordDecl>(DC))
    return NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
                                       RD->getTypeForDecl());
  else if (isa<TranslationUnitDecl>(DC))
    return NestedNameSpecifier::GlobalSpecifier(Context);
}
llvm_unreachable("something isn't in TU scope?")__builtin_unreachable();
547}

549/// Find the parent class with dependent bases of the innermost enclosing method
550/// context. Do not look for enclosing CXXRecordDecls directly, or we will end
551/// up allowing unqualified dependent type names at class-level, which MSVC
552/// correctly rejects.
553static const CXXRecordDecl *
554findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) {
for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) {
  DC = DC->getPrimaryContext();
  if (const auto *MD = dyn_cast<CXXMethodDecl>(DC))
    if (MD->getParent()->hasAnyDependentBases())
      return MD->getParent();
}
return nullptr;
562}

564ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
                                        SourceLocation NameLoc,
                                        bool IsTemplateTypeArg) {
assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode")((void)0);

NestedNameSpecifier *NNS = nullptr;
if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) {
  // If we weren't able to parse a default template argument, delay lookup
  // until instantiation time by making a non-dependent DependentTypeName. We
  // pretend we saw a NestedNameSpecifier referring to the current scope, and
  // lookup is retried.
  // FIXME: This hurts our diagnostic quality, since we get errors like "no
  // type named 'Foo' in 'current_namespace'" when the user didn't write any
  // name specifiers.
  NNS = synthesizeCurrentNestedNameSpecifier(Context, CurContext);
  Diag(NameLoc, diag::ext_ms_delayed_template_argument) << &II;
} else if (const CXXRecordDecl *RD =
               findRecordWithDependentBasesOfEnclosingMethod(CurContext)) {
  // Build a DependentNameType that will perform lookup into RD at
  // instantiation time.
  NNS = NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
                                    RD->getTypeForDecl());

  // Diagnose that this identifier was undeclared, and retry the lookup during
  // template instantiation.
  Diag(NameLoc, diag::ext_undeclared_unqual_id_with_dependent_base) << &II
                                                                    << RD;
} else {
  // This is not a situation that we should recover from.
  return ParsedType();
}

QualType T = Context.getDependentNameType(ETK_None, NNS, &II);

// Build type location information.  We synthesized the qualifier, so we have
// to build a fake NestedNameSpecifierLoc.
NestedNameSpecifierLocBuilder NNSLocBuilder;
NNSLocBuilder.MakeTrivial(Context, NNS, SourceRange(NameLoc));
NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context);

TypeLocBuilder Builder;
DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
DepTL.setNameLoc(NameLoc);
DepTL.setElaboratedKeywordLoc(SourceLocation());
DepTL.setQualifierLoc(QualifierLoc);
return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
610}

612/// isTagName() - This method is called *for error recovery purposes only*
613/// to determine if the specified name is a valid tag name ("struct foo").  If
614/// so, this returns the TST for the tag corresponding to it (TST_enum,
615/// TST_union, TST_struct, TST_interface, TST_class).  This is used to diagnose
616/// cases in C where the user forgot to specify the tag.
617DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
// Do a tag name lookup in this scope.
LookupResult R(*this, &II, SourceLocation(), LookupTagName);
LookupName(R, S, false);
R.suppressDiagnostics();
if (R.getResultKind() == LookupResult::Found)
  if (const TagDecl *TD = R.getAsSingle<TagDecl>()) {
    switch (TD->getTagKind()) {
    case TTK_Struct: return DeclSpec::TST_struct;
    case TTK_Interface: return DeclSpec::TST_interface;
    case TTK_Union:  return DeclSpec::TST_union;
    case TTK_Class:  return DeclSpec::TST_class;
    case TTK_Enum:   return DeclSpec::TST_enum;
    }
  }

return DeclSpec::TST_unspecified;
634}

636/// isMicrosoftMissingTypename - In Microsoft mode, within class scope,
637/// if a CXXScopeSpec's type is equal to the type of one of the base classes
638/// then downgrade the missing typename error to a warning.
639/// This is needed for MSVC compatibility; Example:
640/// @code
641/// template<class T> class A {
642/// public:
643///   typedef int TYPE;
644/// };
645/// template<class T> class B : public A<T> {
646/// public:
647///   A<T>::TYPE a; // no typename required because A<T> is a base class.
648/// };
649/// @endcode
650bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) {
if (CurContext->isRecord()) {
  if (SS->getScopeRep()->getKind() == NestedNameSpecifier::Super)
    return true;

  const Type *Ty = SS->getScopeRep()->getAsType();

  CXXRecordDecl *RD = cast<CXXRecordDecl>(CurContext);
  for (const auto &Base : RD->bases())
    if (Ty && Context.hasSameUnqualifiedType(QualType(Ty, 1), Base.getType()))
      return true;
  return S->isFunctionPrototypeScope();
}
return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope();
664}

666void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II,
                                 SourceLocation IILoc,
                                 Scope *S,
                                 CXXScopeSpec *SS,
                                 ParsedType &SuggestedType,
                                 bool IsTemplateName) {
// Don't report typename errors for editor placeholders.
if (II->isEditorPlaceholder())
  return;
// We don't have anything to suggest (yet).
SuggestedType = nullptr;

// There may have been a typo in the name of the type. Look up typo
// results, in case we have something that we can suggest.
TypeNameValidatorCCC CCC(/*AllowInvalid=*/false, /*WantClass=*/false,
                         /*AllowTemplates=*/IsTemplateName,
                         /*AllowNonTemplates=*/!IsTemplateName);
if (TypoCorrection Corrected =
        CorrectTypo(DeclarationNameInfo(II, IILoc), LookupOrdinaryName, S, SS,
                    CCC, CTK_ErrorRecovery)) {
  // FIXME: Support error recovery for the template-name case.
  bool CanRecover = !IsTemplateName;
  if (Corrected.isKeyword()) {
    // We corrected to a keyword.
    diagnoseTypo(Corrected,
                 PDiag(IsTemplateName ? diag::err_no_template_suggest
                                      : diag::err_unknown_typename_suggest)
                     << II);
    II = Corrected.getCorrectionAsIdentifierInfo();
  } else {
    // We found a similarly-named type or interface; suggest that.
    if (!SS || !SS->isSet()) {
      diagnoseTypo(Corrected,
                   PDiag(IsTemplateName ? diag::err_no_template_suggest
                                        : diag::err_unknown_typename_suggest)
                       << II, CanRecover);
    } else if (DeclContext *DC = computeDeclContext(*SS, false)) {
      std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
      bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
                              II->getName().equals(CorrectedStr);
      diagnoseTypo(Corrected,
                   PDiag(IsTemplateName
                             ? diag::err_no_member_template_suggest
                             : diag::err_unknown_nested_typename_suggest)
                       << II << DC << DroppedSpecifier << SS->getRange(),
                   CanRecover);
    } else {
      llvm_unreachable("could not have corrected a typo here")__builtin_unreachable();
    }

    if (!CanRecover)
      return;

    CXXScopeSpec tmpSS;
    if (Corrected.getCorrectionSpecifier())
      tmpSS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
                        SourceRange(IILoc));
    // FIXME: Support class template argument deduction here.
    SuggestedType =
        getTypeName(*Corrected.getCorrectionAsIdentifierInfo(), IILoc, S,
                    tmpSS.isSet() ? &tmpSS : SS, false, false, nullptr,
                    /*IsCtorOrDtorName=*/false,
                    /*WantNontrivialTypeSourceInfo=*/true);
  }
  return;
}

if (getLangOpts().CPlusPlus && !IsTemplateName) {
  // See if II is a class template that the user forgot to pass arguments to.
  UnqualifiedId Name;
  Name.setIdentifier(II, IILoc);
  CXXScopeSpec EmptySS;
  TemplateTy TemplateResult;
  bool MemberOfUnknownSpecialization;
  if (isTemplateName(S, SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false,
                     Name, nullptr, true, TemplateResult,
                     MemberOfUnknownSpecialization) == TNK_Type_template) {
    diagnoseMissingTemplateArguments(TemplateResult.get(), IILoc);
    return;
  }
}

// FIXME: Should we move the logic that tries to recover from a missing tag
// (struct, union, enum) from Parser::ParseImplicitInt here, instead?

if (!SS || (!SS->isSet() && !SS->isInvalid()))
  Diag(IILoc, IsTemplateName ? diag::err_no_template
                             : diag::err_unknown_typename)
      << II;
else if (DeclContext *DC = computeDeclContext(*SS, false))
  Diag(IILoc, IsTemplateName ? diag::err_no_member_template
                             : diag::err_typename_nested_not_found)
      << II << DC << SS->getRange();
else if (SS->isValid() && SS->getScopeRep()->containsErrors()) {
  SuggestedType =
      ActOnTypenameType(S, SourceLocation(), *SS, *II, IILoc).get();
} else if (isDependentScopeSpecifier(*SS)) {
  unsigned DiagID = diag::err_typename_missing;
  if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S))
    DiagID = diag::ext_typename_missing;

  Diag(SS->getRange().getBegin(), DiagID)
    << SS->getScopeRep() << II->getName()
    << SourceRange(SS->getRange().getBegin(), IILoc)
    << FixItHint::CreateInsertion(SS->getRange().getBegin(), "typename ");
  SuggestedType = ActOnTypenameType(S, SourceLocation(),
                                    *SS, *II, IILoc).get();
} else {
  assert(SS && SS->isInvalid() &&((void)0)
         "Invalid scope specifier has already been diagnosed")((void)0);
}
777}

779/// Determine whether the given result set contains either a type name
780/// or
781static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) {
bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus &&
                     NextToken.is(tok::less);

for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
  if (isa<TypeDecl>(*I) || isa<ObjCInterfaceDecl>(*I))
    return true;

  if (CheckTemplate && isa<TemplateDecl>(*I))
    return true;
}

return false;
794}

796static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result,
                                  Scope *S, CXXScopeSpec &SS,
                                  IdentifierInfo *&Name,
                                  SourceLocation NameLoc) {
LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName);
SemaRef.LookupParsedName(R, S, &SS);
if (TagDecl *Tag = R.getAsSingle<TagDecl>()) {
  StringRef FixItTagName;
  switch (Tag->getTagKind()) {
    case TTK_Class:
      FixItTagName = "class ";
      break;

    case TTK_Enum:
      FixItTagName = "enum ";
      break;

    case TTK_Struct:
      FixItTagName = "struct ";
      break;

    case TTK_Interface:
      FixItTagName = "__interface ";
      break;

    case TTK_Union:
      FixItTagName = "union ";
      break;
  }

  StringRef TagName = FixItTagName.drop_back();
  SemaRef.Diag(NameLoc, diag::err_use_of_tag_name_without_tag)
    << Name << TagName << SemaRef.getLangOpts().CPlusPlus
    << FixItHint::CreateInsertion(NameLoc, FixItTagName);

  for (LookupResult::iterator I = Result.begin(), IEnd = Result.end();
       I != IEnd; ++I)
    SemaRef.Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type)
      << Name << TagName;

  // Replace lookup results with just the tag decl.
  Result.clear(Sema::LookupTagName);
  SemaRef.LookupParsedName(Result, S, &SS);
  return true;
}

return false;
843}

845/// Build a ParsedType for a simple-type-specifier with a nested-name-specifier.
846static ParsedType buildNestedType(Sema &S, CXXScopeSpec &SS,
                                QualType T, SourceLocation NameLoc) {
ASTContext &Context = S.Context;

TypeLocBuilder Builder;
Builder.pushTypeSpec(T).setNameLoc(NameLoc);

T = S.getElaboratedType(ETK_None, SS, T);
ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
ElabTL.setElaboratedKeywordLoc(SourceLocation());
ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
858}

860Sema::NameClassification Sema::ClassifyName(Scope *S, CXXScopeSpec &SS,
                                          IdentifierInfo *&Name,
                                          SourceLocation NameLoc,
                                          const Token &NextToken,
                                          CorrectionCandidateCallback *CCC) {
DeclarationNameInfo NameInfo(Name, NameLoc);
ObjCMethodDecl *CurMethod = getCurMethodDecl();

assert(NextToken.isNot(tok::coloncolon) &&((void)0)
       "parse nested name specifiers before calling ClassifyName")((void)0);
if (getLangOpts().CPlusPlus && SS.isSet() &&
    isCurrentClassName(*Name, S, &SS)) {
  // Per [class.qual]p2, this names the constructors of SS, not the
  // injected-class-name. We don't have a classification for that.
  // There's not much point caching this result, since the parser
  // will reject it later.
  return NameClassification::Unknown();
}

LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
LookupParsedName(Result, S, &SS, !CurMethod);

if (SS.isInvalid())
  return NameClassification::Error();

// For unqualified lookup in a class template in MSVC mode, look into
// dependent base classes where the primary class template is known.
if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) {
  if (ParsedType TypeInBase =
          recoverFromTypeInKnownDependentBase(*this, *Name, NameLoc))
    return TypeInBase;
}

// Perform lookup for Objective-C instance variables (including automatically
// synthesized instance variables), if we're in an Objective-C method.
// FIXME: This lookup really, really needs to be folded in to the normal
// unqualified lookup mechanism.
if (SS.isEmpty() && CurMethod && !isResultTypeOrTemplate(Result, NextToken)) {
  DeclResult Ivar = LookupIvarInObjCMethod(Result, S, Name);
  if (Ivar.isInvalid())
    return NameClassification::Error();
  if (Ivar.isUsable())
    return NameClassification::NonType(cast<NamedDecl>(Ivar.get()));

  // We defer builtin creation until after ivar lookup inside ObjC methods.
  if (Result.empty())
    LookupBuiltin(Result);
}

bool SecondTry = false;
bool IsFilteredTemplateName = false;

912Corrected:
switch (Result.getResultKind()) {
case LookupResult::NotFound:
  // If an unqualified-id is followed by a '(', then we have a function
  // call.
  if (SS.isEmpty() && NextToken.is(tok::l_paren)) {
    // In C++, this is an ADL-only call.
    // FIXME: Reference?
    if (getLangOpts().CPlusPlus)
      return NameClassification::UndeclaredNonType();

    // C90 6.3.2.2:
    //   If the expression that precedes the parenthesized argument list in a
    //   function call consists solely of an identifier, and if no
    //   declaration is visible for this identifier, the identifier is
    //   implicitly declared exactly as if, in the innermost block containing
    //   the function call, the declaration
    //
    //     extern int identifier ();
    //
    //   appeared.
    //
    // We also allow this in C99 as an extension.
    if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S))
      return NameClassification::NonType(D);
  }

  if (getLangOpts().CPlusPlus20 && SS.isEmpty() && NextToken.is(tok::less)) {
    // In C++20 onwards, this could be an ADL-only call to a function
    // template, and we're required to assume that this is a template name.
    //
    // FIXME: Find a way to still do typo correction in this case.
    TemplateName Template =
        Context.getAssumedTemplateName(NameInfo.getName());
    return NameClassification::UndeclaredTemplate(Template);
  }

  // In C, we first see whether there is a tag type by the same name, in
  // which case it's likely that the user just forgot to write "enum",
  // "struct", or "union".
  if (!getLangOpts().CPlusPlus && !SecondTry &&
      isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
    break;
  }

  // Perform typo correction to determine if there is another name that is
  // close to this name.
  if (!SecondTry && CCC) {
    SecondTry = true;
    if (TypoCorrection Corrected =
            CorrectTypo(Result.getLookupNameInfo(), Result.getLookupKind(), S,
                        &SS, *CCC, CTK_ErrorRecovery)) {
      unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest;
      unsigned QualifiedDiag = diag::err_no_member_suggest;

      NamedDecl *FirstDecl = Corrected.getFoundDecl();
      NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl();
      if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
          UnderlyingFirstDecl && isa<TemplateDecl>(UnderlyingFirstDecl)) {
        UnqualifiedDiag = diag::err_no_template_suggest;
        QualifiedDiag = diag::err_no_member_template_suggest;
      } else if (UnderlyingFirstDecl &&
                 (isa<TypeDecl>(UnderlyingFirstDecl) ||
                  isa<ObjCInterfaceDecl>(UnderlyingFirstDecl) ||
                  isa<ObjCCompatibleAliasDecl>(UnderlyingFirstDecl))) {
        UnqualifiedDiag = diag::err_unknown_typename_suggest;
        QualifiedDiag = diag::err_unknown_nested_typename_suggest;
      }

      if (SS.isEmpty()) {
        diagnoseTypo(Corrected, PDiag(UnqualifiedDiag) << Name);
      } else {// FIXME: is this even reachable? Test it.
        std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
        bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
                                Name->getName().equals(CorrectedStr);
        diagnoseTypo(Corrected, PDiag(QualifiedDiag)
                                  << Name << computeDeclContext(SS, false)
                                  << DroppedSpecifier << SS.getRange());
      }

      // Update the name, so that the caller has the new name.
      Name = Corrected.getCorrectionAsIdentifierInfo();

      // Typo correction corrected to a keyword.
      if (Corrected.isKeyword())
        return Name;

      // Also update the LookupResult...
      // FIXME: This should probably go away at some point
      Result.clear();
      Result.setLookupName(Corrected.getCorrection());
      if (FirstDecl)
        Result.addDecl(FirstDecl);

      // If we found an Objective-C instance variable, let
      // LookupInObjCMethod build the appropriate expression to
      // reference the ivar.
      // FIXME: This is a gross hack.
      if (ObjCIvarDecl *Ivar = Result.getAsSingle<ObjCIvarDecl>()) {
        DeclResult R =
            LookupIvarInObjCMethod(Result, S, Ivar->getIdentifier());
        if (R.isInvalid())
          return NameClassification::Error();
        if (R.isUsable())
          return NameClassification::NonType(Ivar);
      }

      goto Corrected;
    }
  }

  // We failed to correct; just fall through and let the parser deal with it.
  Result.suppressDiagnostics();
  return NameClassification::Unknown();

case LookupResult::NotFoundInCurrentInstantiation: {
  // We performed name lookup into the current instantiation, and there were
  // dependent bases, so we treat this result the same way as any other
  // dependent nested-name-specifier.

  // C++ [temp.res]p2:
  //   A name used in a template declaration or definition and that is
  //   dependent on a template-parameter is assumed not to name a type
  //   unless the applicable name lookup finds a type name or the name is
  //   qualified by the keyword typename.
  //
  // FIXME: If the next token is '<', we might want to ask the parser to
  // perform some heroics to see if we actually have a
  // template-argument-list, which would indicate a missing 'template'
  // keyword here.
  return NameClassification::DependentNonType();
}

case LookupResult::Found:
case LookupResult::FoundOverloaded:
case LookupResult::FoundUnresolvedValue:
  break;

case LookupResult::Ambiguous:
  if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
      hasAnyAcceptableTemplateNames(Result, /*AllowFunctionTemplates=*/true,
                                    /*AllowDependent=*/false)) {
    // C++ [temp.local]p3:
    //   A lookup that finds an injected-class-name (10.2) can result in an
    //   ambiguity in certain cases (for example, if it is found in more than
    //   one base class). If all of the injected-class-names that are found
    //   refer to specializations of the same class template, and if the name
    //   is followed by a template-argument-list, the reference refers to the
    //   class template itself and not a specialization thereof, and is not
    //   ambiguous.
    //
    // This filtering can make an ambiguous result into an unambiguous one,
    // so try again after filtering out template names.
    FilterAcceptableTemplateNames(Result);
    if (!Result.isAmbiguous()) {
      IsFilteredTemplateName = true;
      break;
    }
  }

  // Diagnose the ambiguity and return an error.
  return NameClassification::Error();
}

if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
    (IsFilteredTemplateName ||
     hasAnyAcceptableTemplateNames(
         Result, /*AllowFunctionTemplates=*/true,
         /*AllowDependent=*/false,
         /*AllowNonTemplateFunctions*/ SS.isEmpty() &&
             getLangOpts().CPlusPlus20))) {
  // C++ [temp.names]p3:
  //   After name lookup (3.4) finds that a name is a template-name or that
  //   an operator-function-id or a literal- operator-id refers to a set of
  //   overloaded functions any member of which is a function template if
  //   this is followed by a <, the < is always taken as the delimiter of a
  //   template-argument-list and never as the less-than operator.
  // C++2a [temp.names]p2:
  //   A name is also considered to refer to a template if it is an
  //   unqualified-id followed by a < and name lookup finds either one
  //   or more functions or finds nothing.
  if (!IsFilteredTemplateName)
    FilterAcceptableTemplateNames(Result);

  bool IsFunctionTemplate;
  bool IsVarTemplate;
  TemplateName Template;
  if (Result.end() - Result.begin() > 1) {
    IsFunctionTemplate = true;
    Template = Context.getOverloadedTemplateName(Result.begin(),
                                                 Result.end());
  } else if (!Result.empty()) {
    auto *TD = cast<TemplateDecl>(getAsTemplateNameDecl(
        *Result.begin(), /*AllowFunctionTemplates=*/true,
        /*AllowDependent=*/false));
    IsFunctionTemplate = isa<FunctionTemplateDecl>(TD);
    IsVarTemplate = isa<VarTemplateDecl>(TD);

    if (SS.isNotEmpty())
      Template =
          Context.getQualifiedTemplateName(SS.getScopeRep(),
                                           /*TemplateKeyword=*/false, TD);
    else
      Template = TemplateName(TD);
  } else {
    // All results were non-template functions. This is a function template
    // name.
    IsFunctionTemplate = true;
    Template = Context.getAssumedTemplateName(NameInfo.getName());
  }

  if (IsFunctionTemplate) {
    // Function templates always go through overload resolution, at which
    // point we'll perform the various checks (e.g., accessibility) we need
    // to based on which function we selected.
    Result.suppressDiagnostics();

    return NameClassification::FunctionTemplate(Template);
  }

  return IsVarTemplate ? NameClassification::VarTemplate(Template)
                       : NameClassification::TypeTemplate(Template);
}

NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
if (TypeDecl *Type = dyn_cast<TypeDecl>(FirstDecl)) {
  DiagnoseUseOfDecl(Type, NameLoc);
  MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
  QualType T = Context.getTypeDeclType(Type);
  if (SS.isNotEmpty())
    return buildNestedType(*this, SS, T, NameLoc);
  return ParsedType::make(T);
}

ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(FirstDecl);
if (!Class) {
  // FIXME: It's unfortunate that we don't have a Type node for handling this.
  if (ObjCCompatibleAliasDecl *Alias =
          dyn_cast<ObjCCompatibleAliasDecl>(FirstDecl))
    Class = Alias->getClassInterface();
}

if (Class) {
  DiagnoseUseOfDecl(Class, NameLoc);

  if (NextToken.is(tok::period)) {
    // Interface. <something> is parsed as a property reference expression.
    // Just return "unknown" as a fall-through for now.
    Result.suppressDiagnostics();
    return NameClassification::Unknown();
  }

  QualType T = Context.getObjCInterfaceType(Class);
  return ParsedType::make(T);
}

if (isa<ConceptDecl>(FirstDecl))
  return NameClassification::Concept(
      TemplateName(cast<TemplateDecl>(FirstDecl)));

if (auto *EmptyD = dyn_cast<UnresolvedUsingIfExistsDecl>(FirstDecl)) {
  (void)DiagnoseUseOfDecl(EmptyD, NameLoc);
  return NameClassification::Error();
}

// We can have a type template here if we're classifying a template argument.
if (isa<TemplateDecl>(FirstDecl) && !isa<FunctionTemplateDecl>(FirstDecl) &&
    !isa<VarTemplateDecl>(FirstDecl))
  return NameClassification::TypeTemplate(
      TemplateName(cast<TemplateDecl>(FirstDecl)));

// Check for a tag type hidden by a non-type decl in a few cases where it
// seems likely a type is wanted instead of the non-type that was found.
bool NextIsOp = NextToken.isOneOf(tok::amp, tok::star);
if ((NextToken.is(tok::identifier) ||
     (NextIsOp &&
      FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) &&
    isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
  TypeDecl *Type = Result.getAsSingle<TypeDecl>();
  DiagnoseUseOfDecl(Type, NameLoc);
  QualType T = Context.getTypeDeclType(Type);
  if (SS.isNotEmpty())
    return buildNestedType(*this, SS, T, NameLoc);
  return ParsedType::make(T);
}

// If we already know which single declaration is referenced, just annotate
// that declaration directly. Defer resolving even non-overloaded class
// member accesses, as we need to defer certain access checks until we know
// the context.
bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
if (Result.isSingleResult() && !ADL && !FirstDecl->isCXXClassMember())
  return NameClassification::NonType(Result.getRepresentativeDecl());

// Otherwise, this is an overload set that we will need to resolve later.
Result.suppressDiagnostics();
return NameClassification::OverloadSet(UnresolvedLookupExpr::Create(
    Context, Result.getNamingClass(), SS.getWithLocInContext(Context),
    Result.getLookupNameInfo(), ADL, Result.isOverloadedResult(),
    Result.begin(), Result.end()));
1212}

1214ExprResult
1215Sema::ActOnNameClassifiedAsUndeclaredNonType(IdentifierInfo *Name,
                                           SourceLocation NameLoc) {
assert(getLangOpts().CPlusPlus && "ADL-only call in C?")((void)0);
CXXScopeSpec SS;
LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
return BuildDeclarationNameExpr(SS, Result, /*ADL=*/true);
1221}

1223ExprResult
1224Sema::ActOnNameClassifiedAsDependentNonType(const CXXScopeSpec &SS,
                                          IdentifierInfo *Name,
                                          SourceLocation NameLoc,
                                          bool IsAddressOfOperand) {
DeclarationNameInfo NameInfo(Name, NameLoc);
return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(),
                                  NameInfo, IsAddressOfOperand,
                                  /*TemplateArgs=*/nullptr);
1232}

1234ExprResult Sema::ActOnNameClassifiedAsNonType(Scope *S, const CXXScopeSpec &SS,
                                            NamedDecl *Found,
                                            SourceLocation NameLoc,
                                            const Token &NextToken) {
if (getCurMethodDecl() && SS.isEmpty())
  if (auto *Ivar = dyn_cast<ObjCIvarDecl>(Found->getUnderlyingDecl()))
    return BuildIvarRefExpr(S, NameLoc, Ivar);

// Reconstruct the lookup result.
LookupResult Result(*this, Found->getDeclName(), NameLoc, LookupOrdinaryName);
Result.addDecl(Found);
Result.resolveKind();

bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
return BuildDeclarationNameExpr(SS, Result, ADL);
1249}

1251ExprResult Sema::ActOnNameClassifiedAsOverloadSet(Scope *S, Expr *E) {
// For an implicit class member access, transform the result into a member
// access expression if necessary.
auto *ULE = cast<UnresolvedLookupExpr>(E);
if ((*ULE->decls_begin())->isCXXClassMember()) {
  CXXScopeSpec SS;
  SS.Adopt(ULE->getQualifierLoc());

  // Reconstruct the lookup result.
  LookupResult Result(*this, ULE->getName(), ULE->getNameLoc(),
                      LookupOrdinaryName);
  Result.setNamingClass(ULE->getNamingClass());
  for (auto I = ULE->decls_begin(), E = ULE->decls_end(); I != E; ++I)
    Result.addDecl(*I, I.getAccess());
  Result.resolveKind();
  return BuildPossibleImplicitMemberExpr(SS, SourceLocation(), Result,
                                         nullptr, S);
}

// Otherwise, this is already in the form we needed, and no further checks
// are necessary.
return ULE;
1273}

1275Sema::TemplateNameKindForDiagnostics
1276Sema::getTemplateNameKindForDiagnostics(TemplateName Name) {
auto *TD = Name.getAsTemplateDecl();
if (!TD)
  return TemplateNameKindForDiagnostics::DependentTemplate;
if (isa<ClassTemplateDecl>(TD))
  return TemplateNameKindForDiagnostics::ClassTemplate;
if (isa<FunctionTemplateDecl>(TD))
  return TemplateNameKindForDiagnostics::FunctionTemplate;
if (isa<VarTemplateDecl>(TD))
  return TemplateNameKindForDiagnostics::VarTemplate;
if (isa<TypeAliasTemplateDecl>(TD))
  return TemplateNameKindForDiagnostics::AliasTemplate;
if (isa<TemplateTemplateParmDecl>(TD))
  return TemplateNameKindForDiagnostics::TemplateTemplateParam;
if (isa<ConceptDecl>(TD))
  return TemplateNameKindForDiagnostics::Concept;
return TemplateNameKindForDiagnostics::DependentTemplate;
1293}

1295void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
assert(DC->getLexicalParent() == CurContext &&((void)0)
    "The next DeclContext should be lexically contained in the current one.")((void)0);
CurContext = DC;
S->setEntity(DC);
1300}

1302void Sema::PopDeclContext() {
assert(CurContext && "DeclContext imbalance!")((void)0);

CurContext = CurContext->getLexicalParent();
assert(CurContext && "Popped translation unit!")((void)0);
1307}

1309Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S,
                                                                  Decl *D) {
// Unlike PushDeclContext, the context to which we return is not necessarily
// the containing DC of TD, because the new context will be some pre-existing
// TagDecl definition instead of a fresh one.
auto Result = static_cast<SkippedDefinitionContext>(CurContext);
CurContext = cast<TagDecl>(D)->getDefinition();
assert(CurContext && "skipping definition of undefined tag")((void)0);
// Start lookups from the parent of the current context; we don't want to look
// into the pre-existing complete definition.
S->setEntity(CurContext->getLookupParent());
return Result;
1321}

1323void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) {
CurContext = static_cast<decltype(CurContext)>(Context);
1325}

1327/// EnterDeclaratorContext - Used when we must lookup names in the context
1328/// of a declarator's nested name specifier.
1329///
1330void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) {
// C++0x [basic.lookup.unqual]p13:
//   A name used in the definition of a static data member of class
//   X (after the qualified-id of the static member) is looked up as
//   if the name was used in a member function of X.
// C++0x [basic.lookup.unqual]p14:
//   If a variable member of a namespace is defined outside of the
//   scope of its namespace then any name used in the definition of
//   the variable member (after the declarator-id) is looked up as
//   if the definition of the variable member occurred in its
//   namespace.
// Both of these imply that we should push a scope whose context
// is the semantic context of the declaration.  We can't use
// PushDeclContext here because that context is not necessarily
// lexically contained in the current context.  Fortunately,
// the containing scope should have the appropriate information.

assert(!S->getEntity() && "scope already has entity")((void)0);

1349#ifndef NDEBUG1
Scope *Ancestor = S->getParent();
while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch")((void)0);
1353#endif

CurContext = DC;
S->setEntity(DC);

if (S->getParent()->isTemplateParamScope()) {
  // Also set the corresponding entities for all immediately-enclosing
  // template parameter scopes.
  EnterTemplatedContext(S->getParent(), DC);
}
1363}

1365void Sema::ExitDeclaratorContext(Scope *S) {
assert(S->getEntity() == CurContext && "Context imbalance!")((void)0);

// Switch back to the lexical context.  The safety of this is
// enforced by an assert in EnterDeclaratorContext.
Scope *Ancestor = S->getParent();
while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
CurContext = Ancestor->getEntity();

// We don't need to do anything with the scope, which is going to
// disappear.
1376}

1378void Sema::EnterTemplatedContext(Scope *S, DeclContext *DC) {
assert(S->isTemplateParamScope() &&((void)0)
       "expected to be initializing a template parameter scope")((void)0);

// C++20 [temp.local]p7:
//   In the definition of a member of a class template that appears outside
//   of the class template definition, the name of a member of the class
//   template hides the name of a template-parameter of any enclosing class
//   templates (but not a template-parameter of the member if the member is a
//   class or function template).
// C++20 [temp.local]p9:
//   In the definition of a class template or in the definition of a member
//   of such a template that appears outside of the template definition, for
//   each non-dependent base class (13.8.2.1), if the name of the base class
//   or the name of a member of the base class is the same as the name of a
//   template-parameter, the base class name or member name hides the
//   template-parameter name (6.4.10).
//
// This means that a template parameter scope should be searched immediately
// after searching the DeclContext for which it is a template parameter
// scope. For example, for
//   template<typename T> template<typename U> template<typename V>
//     void N::A<T>::B<U>::f(...)
// we search V then B<U> (and base classes) then U then A<T> (and base
// classes) then T then N then ::.
unsigned ScopeDepth = getTemplateDepth(S);
for (; S && S->isTemplateParamScope(); S = S->getParent(), --ScopeDepth) {
  DeclContext *SearchDCAfterScope = DC;
  for (; DC; DC = DC->getLookupParent()) {
    if (const TemplateParameterList *TPL =
            cast<Decl>(DC)->getDescribedTemplateParams()) {
      unsigned DCDepth = TPL->getDepth() + 1;
      if (DCDepth > ScopeDepth)
        continue;
      if (ScopeDepth == DCDepth)
        SearchDCAfterScope = DC = DC->getLookupParent();
      break;
    }
  }
  S->setLookupEntity(SearchDCAfterScope);
}
1419}

1421void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) {
// We assume that the caller has already called
// ActOnReenterTemplateScope so getTemplatedDecl() works.
FunctionDecl *FD = D->getAsFunction();
if (!FD)
  return;

// Same implementation as PushDeclContext, but enters the context
// from the lexical parent, rather than the top-level class.
assert(CurContext == FD->getLexicalParent() &&((void)0)
  "The next DeclContext should be lexically contained in the current one.")((void)0);
CurContext = FD;
S->setEntity(CurContext);

for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) {
  ParmVarDecl *Param = FD->getParamDecl(P);
  // If the parameter has an identifier, then add it to the scope
  if (Param->getIdentifier()) {
    S->AddDecl(Param);
    IdResolver.AddDecl(Param);
  }
}
1443}

1445void Sema::ActOnExitFunctionContext() {
// Same implementation as PopDeclContext, but returns to the lexical parent,
// rather than the top-level class.
assert(CurContext && "DeclContext imbalance!")((void)0);
CurContext = CurContext->getLexicalParent();
assert(CurContext && "Popped translation unit!")((void)0);
1451}

1453/// Determine whether we allow overloading of the function
1454/// PrevDecl with another declaration.
1455///
1456/// This routine determines whether overloading is possible, not
1457/// whether some new function is actually an overload. It will return
1458/// true in C++ (where we can always provide overloads) or, as an
1459/// extension, in C when the previous function is already an
1460/// overloaded function declaration or has the "overloadable"
1461/// attribute.
1462static bool AllowOverloadingOfFunction(LookupResult &Previous,
                                     ASTContext &Context,
                                     const FunctionDecl *New) {
if (Context.getLangOpts().CPlusPlus)
  return true;

if (Previous.getResultKind() == LookupResult::FoundOverloaded)
  return true;

return Previous.getResultKind() == LookupResult::Found &&
       (Previous.getFoundDecl()->hasAttr<OverloadableAttr>() ||
        New->hasAttr<OverloadableAttr>());
1474}

1476/// Add this decl to the scope shadowed decl chains.
1477void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) {
// Move up the scope chain until we find the nearest enclosing
// non-transparent context. The declaration will be introduced into this
// scope.
while (S->getEntity() && S->getEntity()->isTransparentContext())
  S = S->getParent();

// Add scoped declarations into their context, so that they can be
// found later. Declarations without a context won't be inserted
// into any context.
if (AddToContext)
  CurContext->addDecl(D);

// Out-of-line definitions shouldn't be pushed into scope in C++, unless they
// are function-local declarations.
if (getLangOpts().CPlusPlus && D->isOutOfLine() && !S->getFnParent())
  return;

// Template instantiations should also not be pushed into scope.
if (isa<FunctionDecl>(D) &&
    cast<FunctionDecl>(D)->isFunctionTemplateSpecialization())
  return;

// If this replaces anything in the current scope,
IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()),
                             IEnd = IdResolver.end();
for (; I != IEnd; ++I) {
  if (S->isDeclScope(*I) && D->declarationReplaces(*I)) {
    S->RemoveDecl(*I);
    IdResolver.RemoveDecl(*I);

    // Should only need to replace one decl.
    break;
  }
}

S->AddDecl(D);

if (isa<LabelDecl>(D) && !cast<LabelDecl>(D)->isGnuLocal()) {
  // Implicitly-generated labels may end up getting generated in an order that
  // isn't strictly lexical, which breaks name lookup. Be careful to insert
  // the label at the appropriate place in the identifier chain.
  for (I = IdResolver.begin(D->getDeclName()); I != IEnd; ++I) {
    DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext();
    if (IDC == CurContext) {
      if (!S->isDeclScope(*I))
        continue;
    } else if (IDC->Encloses(CurContext))
      break;
  }

  IdResolver.InsertDeclAfter(I, D);
} else {
  IdResolver.AddDecl(D);
}
warnOnReservedIdentifier(D);
1533}

1535bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S,
                       bool AllowInlineNamespace) {
return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace);
1538}

1540Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) {
DeclContext *TargetDC = DC->getPrimaryContext();
do {
  if (DeclContext *ScopeDC = S->getEntity())
    if (ScopeDC->getPrimaryContext() == TargetDC)
      return S;
} while ((S = S->getParent()));

return nullptr;
1549}

1551static bool isOutOfScopePreviousDeclaration(NamedDecl *,
                                          DeclContext*,
                                          ASTContext&);

1555/// Filters out lookup results that don't fall within the given scope
1556/// as determined by isDeclInScope.
1557void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
                              bool ConsiderLinkage,
                              bool AllowInlineNamespace) {
LookupResult::Filter F = R.makeFilter();
while (F.hasNext()) {
  NamedDecl *D = F.next();

  if (isDeclInScope(D, Ctx, S, AllowInlineNamespace))
    continue;

  if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context))
    continue;

  F.erase();
}

F.done();
1574}

1576/// We've determined that \p New is a redeclaration of \p Old. Check that they
1577/// have compatible owning modules.
1578bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) {
// FIXME: The Modules TS is not clear about how friend declarations are
// to be treated. It's not meaningful to have different owning modules for
// linkage in redeclarations of the same entity, so for now allow the
// redeclaration and change the owning modules to match.
if (New->getFriendObjectKind() &&
    Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) {
  New->setLocalOwningModule(Old->getOwningModule());
  makeMergedDefinitionVisible(New);
  return false;
}

Module *NewM = New->getOwningModule();
Module *OldM = Old->getOwningModule();

if (NewM && NewM->Kind == Module::PrivateModuleFragment)
  NewM = NewM->Parent;
if (OldM && OldM->Kind == Module::PrivateModuleFragment)
  OldM = OldM->Parent;

if (NewM == OldM)
  return false;

bool NewIsModuleInterface = NewM && NewM->isModulePurview();
bool OldIsModuleInterface = OldM && OldM->isModulePurview();
if (NewIsModuleInterface || OldIsModuleInterface) {
  // C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]:
  //   if a declaration of D [...] appears in the purview of a module, all
  //   other such declarations shall appear in the purview of the same module
  Diag(New->getLocation(), diag::err_mismatched_owning_module)
    << New
    << NewIsModuleInterface
    << (NewIsModuleInterface ? NewM->getFullModuleName() : "")
    << OldIsModuleInterface
    << (OldIsModuleInterface ? OldM->getFullModuleName() : "");
  Diag(Old->getLocation(), diag::note_previous_declaration);
  New->setInvalidDecl();
  return true;
}

return false;
1619}

1621static bool isUsingDecl(NamedDecl *D) {
return isa<UsingShadowDecl>(D) ||
       isa<UnresolvedUsingTypenameDecl>(D) ||
       isa<UnresolvedUsingValueDecl>(D);
1625}

1627/// Removes using shadow declarations from the lookup results.
1628static void RemoveUsingDecls(LookupResult &R) {
LookupResult::Filter F = R.makeFilter();
while (F.hasNext())
  if (isUsingDecl(F.next()))
    F.erase();

F.done();
1635}

1637/// Check for this common pattern:
1638/// @code
1639/// class S {
1640///   S(const S&); // DO NOT IMPLEMENT
1641///   void operator=(const S&); // DO NOT IMPLEMENT
1642/// };
1643/// @endcode
1644static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) {
// FIXME: Should check for private access too but access is set after we get
// the decl here.
if (D->doesThisDeclarationHaveABody())
  return false;

if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
  return CD->isCopyConstructor();
return D->isCopyAssignmentOperator();
1653}

1655// We need this to handle
1656//
1657// typedef struct {
1658//   void *foo() { return 0; }
1659// } A;
1660//
1661// When we see foo we don't know if after the typedef we will get 'A' or '*A'
1662// for example. If 'A', foo will have external linkage. If we have '*A',
1663// foo will have no linkage. Since we can't know until we get to the end
1664// of the typedef, this function finds out if D might have non-external linkage.
1665// Callers should verify at the end of the TU if it D has external linkage or
1666// not.
1667bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) {
const DeclContext *DC = D->getDeclContext();
while (!DC->isTranslationUnit()) {
  if (const RecordDecl *RD = dyn_cast<RecordDecl>(DC)){
    if (!RD->hasNameForLinkage())
      return true;
  }
  DC = DC->getParent();
}

return !D->isExternallyVisible();
1678}

1680// FIXME: This needs to be refactored; some other isInMainFile users want
1681// these semantics.
1682static bool isMainFileLoc(const Sema &S, SourceLocation Loc) {
if (S.TUKind != TU_Complete)
  return false;
return S.SourceMgr.isInMainFile(Loc);
1686}

1688bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const {
assert(D)((void)0);

if (D->isInvalidDecl() || D->isUsed() || D->hasAttr<UnusedAttr>())
  return false;

// Ignore all entities declared within templates, and out-of-line definitions
// of members of class templates.
if (D->getDeclContext()->isDependentContext() ||
    D->getLexicalDeclContext()->isDependentContext())
  return false;

if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
  if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
    return false;
  // A non-out-of-line declaration of a member specialization was implicitly
  // instantiated; it's the out-of-line declaration that we're interested in.
  if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
      FD->getMemberSpecializationInfo() && !FD->isOutOfLine())
    return false;

  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
    if (MD->isVirtual() || IsDisallowedCopyOrAssign(MD))
      return false;
  } else {
    // 'static inline' functions are defined in headers; don't warn.
    if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation()))
      return false;
  }

  if (FD->doesThisDeclarationHaveABody() &&
      Context.DeclMustBeEmitted(FD))
    return false;
} else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
  // Constants and utility variables are defined in headers with internal
  // linkage; don't warn.  (Unlike functions, there isn't a convenient marker
  // like "inline".)
  if (!isMainFileLoc(*this, VD->getLocation()))
    return false;

  if (Context.DeclMustBeEmitted(VD))
    return false;

  if (VD->isStaticDataMember() &&
      VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
    return false;
  if (VD->isStaticDataMember() &&
      VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
      VD->getMemberSpecializationInfo() && !VD->isOutOfLine())
    return false;

  if (VD->isInline() && !isMainFileLoc(*this, VD->getLocation()))
    return false;
} else {
  return false;
}

// Only warn for unused decls internal to the translation unit.
// FIXME: This seems like a bogus check; it suppresses -Wunused-function
// for inline functions defined in the main source file, for instance.
return mightHaveNonExternalLinkage(D);
1749}

1751void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) {
if (!D)
  return;

if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
  const FunctionDecl *First = FD->getFirstDecl();
  if (FD != First && ShouldWarnIfUnusedFileScopedDecl(First))
    return; // First should already be in the vector.
}

if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
  const VarDecl *First = VD->getFirstDecl();
  if (VD != First && ShouldWarnIfUnusedFileScopedDecl(First))
    return; // First should already be in the vector.
}

if (ShouldWarnIfUnusedFileScopedDecl(D))
  UnusedFileScopedDecls.push_back(D);
1769}

1771static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) {
if (D->isInvalidDecl())
  return false;

if (auto *DD = dyn_cast<DecompositionDecl>(D)) {
  // For a decomposition declaration, warn if none of the bindings are
  // referenced, instead of if the variable itself is referenced (which
  // it is, by the bindings' expressions).
  for (auto *BD : DD->bindings())
    if (BD->isReferenced())
      return false;
} else if (!D->getDeclName()) {
  return false;
} else if (D->isReferenced() || D->isUsed()) {
  return false;
}

if (D->hasAttr<UnusedAttr>() || D->hasAttr<ObjCPreciseLifetimeAttr>())
  return false;

if (isa<LabelDecl>(D))
  return true;

// Except for labels, we only care about unused decls that are local to
// functions.
bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
  // For dependent types, the diagnostic is deferred.
  WithinFunction =
      WithinFunction || (R->isLocalClass() && !R->isDependentType());
if (!WithinFunction)
  return false;

if (isa<TypedefNameDecl>(D))
  return true;

// White-list anything that isn't a local variable.
if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D))
  return false;

// Types of valid local variables should be complete, so this should succeed.
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {

  // White-list anything with an __attribute__((unused)) type.
  const auto *Ty = VD->getType().getTypePtr();

  // Only look at the outermost level of typedef.
  if (const TypedefType *TT = Ty->getAs<TypedefType>()) {
    if (TT->getDecl()->hasAttr<UnusedAttr>())
      return false;
  }

  // If we failed to complete the type for some reason, or if the type is
  // dependent, don't diagnose the variable.
  if (Ty->isIncompleteType() || Ty->isDependentType())
    return false;

  // Look at the element type to ensure that the warning behaviour is
  // consistent for both scalars and arrays.
  Ty = Ty->getBaseElementTypeUnsafe();

  if (const TagType *TT = Ty->getAs<TagType>()) {
    const TagDecl *Tag = TT->getDecl();
    if (Tag->hasAttr<UnusedAttr>())
      return false;

    if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Tag)) {
      if (!RD->hasTrivialDestructor() && !RD->hasAttr<WarnUnusedAttr>())
        return false;

      if (const Expr *Init = VD->getInit()) {
        if (const ExprWithCleanups *Cleanups =
                dyn_cast<ExprWithCleanups>(Init))
          Init = Cleanups->getSubExpr();
        const CXXConstructExpr *Construct =
          dyn_cast<CXXConstructExpr>(Init);
        if (Construct && !Construct->isElidable()) {
          CXXConstructorDecl *CD = Construct->getConstructor();
          if (!CD->isTrivial() && !RD->hasAttr<WarnUnusedAttr>() &&
              (VD->getInit()->isValueDependent() || !VD->evaluateValue()))
            return false;
        }

        // Suppress the warning if we don't know how this is constructed, and
        // it could possibly be non-trivial constructor.
        if (Init->isTypeDependent())
          for (const CXXConstructorDecl *Ctor : RD->ctors())
            if (!Ctor->isTrivial())
              return false;
      }
    }
  }

  // TODO: __attribute__((unused)) templates?
}

return true;
1868}

1870static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx,
                                   FixItHint &Hint) {
if (isa<LabelDecl>(D)) {
  SourceLocation AfterColon = Lexer::findLocationAfterToken(
      D->getEndLoc(), tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(),
      true);
  if (AfterColon.isInvalid())
    return;
  Hint = FixItHint::CreateRemoval(
      CharSourceRange::getCharRange(D->getBeginLoc(), AfterColon));
}
1881}

1883void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
if (D->getTypeForDecl()->isDependentType())
  return;

for (auto *TmpD : D->decls()) {
  if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
    DiagnoseUnusedDecl(T);
  else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
    DiagnoseUnusedNestedTypedefs(R);
}
1893}

1895/// DiagnoseUnusedDecl - Emit warnings about declarations that are not used
1896/// unless they are marked attr(unused).
1897void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
if (!ShouldDiagnoseUnusedDecl(D))
  return;

if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
  // typedefs can be referenced later on, so the diagnostics are emitted
  // at end-of-translation-unit.
  UnusedLocalTypedefNameCandidates.insert(TD);
  return;
}

FixItHint Hint;
GenerateFixForUnusedDecl(D, Context, Hint);

unsigned DiagID;
if (isa<VarDecl>(D) && cast<VarDecl>(D)->isExceptionVariable())
  DiagID = diag::warn_unused_exception_param;
else if (isa<LabelDecl>(D))
  DiagID = diag::warn_unused_label;
else
  DiagID = diag::warn_unused_variable;

Diag(D->getLocation(), DiagID) << D << Hint;
1920}

1922void Sema::DiagnoseUnusedButSetDecl(const VarDecl *VD) {
// If it's not referenced, it can't be set.
if (!VD->isReferenced() || !VD->getDeclName() || VD->hasAttr<UnusedAttr>())
  return;

const auto *Ty = VD->getType().getTypePtr()->getBaseElementTypeUnsafe();

if (Ty->isReferenceType() || Ty->isDependentType())
  return;

if (const TagType *TT = Ty->getAs<TagType>()) {
  const TagDecl *Tag = TT->getDecl();
  if (Tag->hasAttr<UnusedAttr>())
    return;
  // In C++, don't warn for record types that don't have WarnUnusedAttr, to
  // mimic gcc's behavior.
  if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Tag)) {
    if (!RD->hasAttr<WarnUnusedAttr>())
      return;
  }
}

auto iter = RefsMinusAssignments.find(VD);
if (iter == RefsMinusAssignments.end())
  return;

assert(iter->getSecond() >= 0 &&((void)0)
       "Found a negative number of references to a VarDecl")((void)0);
if (iter->getSecond() != 0)
  return;
unsigned DiagID = isa<ParmVarDecl>(VD) ? diag::warn_unused_but_set_parameter
                                       : diag::warn_unused_but_set_variable;
Diag(VD->getLocation(), DiagID) << VD;
1955}

1957static void CheckPoppedLabel(LabelDecl *L, Sema &S) {
// Verify that we have no forward references left.  If so, there was a goto
// or address of a label taken, but no definition of it.  Label fwd
// definitions are indicated with a null substmt which is also not a resolved
// MS inline assembly label name.
bool Diagnose = false;
if (L->isMSAsmLabel())
  Diagnose = !L->isResolvedMSAsmLabel();
else
  Diagnose = L->getStmt() == nullptr;
if (Diagnose)
  S.Diag(L->getLocation(), diag::err_undeclared_label_use) << L;
1969}

1971void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
S->mergeNRVOIntoParent();

if (S->decl_empty()) return;
assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&((void)0)
       "Scope shouldn't contain decls!")((void)0);

for (auto *TmpD : S->decls()) {
  assert(TmpD && "This decl didn't get pushed??")((void)0);

  assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?")((void)0);
  NamedDecl *D = cast<NamedDecl>(TmpD);

  // Diagnose unused variables in this scope.
  if (!S->hasUnrecoverableErrorOccurred()) {
    DiagnoseUnusedDecl(D);
    if (const auto *RD = dyn_cast<RecordDecl>(D))
      DiagnoseUnusedNestedTypedefs(RD);
    if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
      DiagnoseUnusedButSetDecl(VD);
      RefsMinusAssignments.erase(VD);
    }
  }

  if (!D->getDeclName()) continue;

  // If this was a forward reference to a label, verify it was defined.
  if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
    CheckPoppedLabel(LD, *this);

  // Remove this name from our lexical scope, and warn on it if we haven't
  // already.
  IdResolver.RemoveDecl(D);
  auto ShadowI = ShadowingDecls.find(D);
  if (ShadowI != ShadowingDecls.end()) {
    if (const auto *FD = dyn_cast<FieldDecl>(ShadowI->second)) {
      Diag(D->getLocation(), diag::warn_ctor_parm_shadows_field)
          << D << FD << FD->getParent();
      Diag(FD->getLocation(), diag::note_previous_declaration);
    }
    ShadowingDecls.erase(ShadowI);
  }
}
2014}

2016/// Look for an Objective-C class in the translation unit.
2017///
2018/// \param Id The name of the Objective-C class we're looking for. If
2019/// typo-correction fixes this name, the Id will be updated
2020/// to the fixed name.
2021///
2022/// \param IdLoc The location of the name in the translation unit.
2023///
2024/// \param DoTypoCorrection If true, this routine will attempt typo correction
2025/// if there is no class with the given name.
2026///
2027/// \returns The declaration of the named Objective-C class, or NULL if the
2028/// class could not be found.
2029ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id,
                                            SourceLocation IdLoc,
                                            bool DoTypoCorrection) {
// The third "scope" argument is 0 since we aren't enabling lazy built-in
// creation from this context.
NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName);

if (!IDecl && DoTypoCorrection) {
  // Perform typo correction at the given location, but only if we
  // find an Objective-C class name.
  DeclFilterCCC<ObjCInterfaceDecl> CCC{};
  if (TypoCorrection C =
          CorrectTypo(DeclarationNameInfo(Id, IdLoc), LookupOrdinaryName,
                      TUScope, nullptr, CCC, CTK_ErrorRecovery)) {
    diagnoseTypo(C, PDiag(diag::err_undef_interface_suggest) << Id);
    IDecl = C.getCorrectionDeclAs<ObjCInterfaceDecl>();
    Id = IDecl->getIdentifier();
  }
}
ObjCInterfaceDecl *Def = dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
// This routine must always return a class definition, if any.
if (Def && Def->getDefinition())
    Def = Def->getDefinition();
return Def;
2053}

2055/// getNonFieldDeclScope - Retrieves the innermost scope, starting
2056/// from S, where a non-field would be declared. This routine copes
2057/// with the difference between C and C++ scoping rules in structs and
2058/// unions. For example, the following code is well-formed in C but
2059/// ill-formed in C++:
2060/// @code
2061/// struct S6 {
2062///   enum { BAR } e;
2063/// };
2064///
2065/// void test_S6() {
2066///   struct S6 a;
2067///   a.e = BAR;
2068/// }
2069/// @endcode
2070/// For the declaration of BAR, this routine will return a different
2071/// scope. The scope S will be the scope of the unnamed enumeration
2072/// within S6. In C++, this routine will return the scope associated
2073/// with S6, because the enumeration's scope is a transparent
2074/// context but structures can contain non-field names. In C, this
2075/// routine will return the translation unit scope, since the
2076/// enumeration's scope is a transparent context and structures cannot
2077/// contain non-field names.
2078Scope *Sema::getNonFieldDeclScope(Scope *S) {
while (((S->getFlags() & Scope::DeclScope) == 0) ||
       (S->getEntity() && S->getEntity()->isTransparentContext()) ||
       (S->isClassScope() && !getLangOpts().CPlusPlus))
  S = S->getParent();
return S;
2084}

2086static StringRef getHeaderName(Builtin::Context &BuiltinInfo, unsigned ID,
                             ASTContext::GetBuiltinTypeError Error) {
switch (Error) {
case ASTContext::GE_None:
  return "";
case ASTContext::GE_Missing_type:
  return BuiltinInfo.getHeaderName(ID);
case ASTContext::GE_Missing_stdio:
  return "stdio.h";
case ASTContext::GE_Missing_setjmp:
  return "setjmp.h";
case ASTContext::GE_Missing_ucontext:
  return "ucontext.h";
}
llvm_unreachable("unhandled error kind")__builtin_unreachable();
2101}

2103FunctionDecl *Sema::CreateBuiltin(IdentifierInfo *II, QualType Type,
                                unsigned ID, SourceLocation Loc) {
DeclContext *Parent = Context.getTranslationUnitDecl();

if (getLangOpts().CPlusPlus) {
  LinkageSpecDecl *CLinkageDecl = LinkageSpecDecl::Create(
      Context, Parent, Loc, Loc, LinkageSpecDecl::lang_c, false);
  CLinkageDecl->setImplicit();
  Parent->addDecl(CLinkageDecl);
  Parent = CLinkageDecl;
}

FunctionDecl *New = FunctionDecl::Create(Context, Parent, Loc, Loc, II, Type,
                                         /*TInfo=*/nullptr, SC_Extern, false,
                                         Type->isFunctionProtoType());
New->setImplicit();
New->addAttr(BuiltinAttr::CreateImplicit(Context, ID));

// Create Decl objects for each parameter, adding them to the
// FunctionDecl.
if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(Type)) {
  SmallVector<ParmVarDecl *, 16> Params;
  for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
    ParmVarDecl *parm = ParmVarDecl::Create(
        Context, New, SourceLocation(), SourceLocation(), nullptr,
        FT->getParamType(i), /*TInfo=*/nullptr, SC_None, nullptr);
    parm->setScopeInfo(0, i);
    Params.push_back(parm);
  }
  New->setParams(Params);
}

AddKnownFunctionAttributes(New);
return New;
2137}

2139/// LazilyCreateBuiltin - The specified Builtin-ID was first used at
2140/// file scope.  lazily create a decl for it. ForRedeclaration is true
2141/// if we're creating this built-in in anticipation of redeclaring the
2142/// built-in.
2143NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
                                   Scope *S, bool ForRedeclaration,
                                   SourceLocation Loc) {
LookupNecessaryTypesForBuiltin(S, ID);

ASTContext::GetBuiltinTypeError Error;
QualType R = Context.GetBuiltinType(ID, Error);
if (Error) {
  if (!ForRedeclaration)
    return nullptr;

  // If we have a builtin without an associated type we should not emit a
  // warning when we were not able to find a type for it.
  if (Error == ASTContext::GE_Missing_type ||
      Context.BuiltinInfo.allowTypeMismatch(ID))
    return nullptr;

  // If we could not find a type for setjmp it is because the jmp_buf type was
  // not defined prior to the setjmp declaration.
  if (Error == ASTContext::GE_Missing_setjmp) {
    Diag(Loc, diag::warn_implicit_decl_no_jmp_buf)
        << Context.BuiltinInfo.getName(ID);
    return nullptr;
  }

  // Generally, we emit a warning that the declaration requires the
  // appropriate header.
  Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
      << getHeaderName(Context.BuiltinInfo, ID, Error)
      << Context.BuiltinInfo.getName(ID);
  return nullptr;
}

if (!ForRedeclaration &&
    (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
     Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
  Diag(Loc, diag::ext_implicit_lib_function_decl)
      << Context.BuiltinInfo.getName(ID) << R;
  if (const char *Header = Context.BuiltinInfo.getHeaderName(ID))
    Diag(Loc, diag::note_include_header_or_declare)
        << Header << Context.BuiltinInfo.getName(ID);
}

if (R.isNull())
  return nullptr;

FunctionDecl *New = CreateBuiltin(II, R, ID, Loc);
RegisterLocallyScopedExternCDecl(New, S);

// TUScope is the translation-unit scope to insert this function into.
// FIXME: This is hideous. We need to teach PushOnScopeChains to
// relate Scopes to DeclContexts, and probably eliminate CurContext
// entirely, but we're not there yet.
DeclContext *SavedContext = CurContext;
CurContext = New->getDeclContext();
PushOnScopeChains(New, TUScope);
CurContext = SavedContext;
return New;
2201}

2203/// Typedef declarations don't have linkage, but they still denote the same
2204/// entity if their types are the same.
2205/// FIXME: This is notionally doing the same thing as ASTReaderDecl's
2206/// isSameEntity.
2207static void filterNonConflictingPreviousTypedefDecls(Sema &S,
                                                   TypedefNameDecl *Decl,
                                                   LookupResult &Previous) {
// This is only interesting when modules are enabled.
if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
  return;

// Empty sets are uninteresting.
if (Previous.empty())
  return;

LookupResult::Filter Filter = Previous.makeFilter();
while (Filter.hasNext()) {
  NamedDecl *Old = Filter.next();

  // Non-hidden declarations are never ignored.
  if (S.isVisible(Old))
    continue;

  // Declarations of the same entity are not ignored, even if they have
  // different linkages.
  if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
    if (S.Context.hasSameType(OldTD->getUnderlyingType(),
                              Decl->getUnderlyingType()))
      continue;

    // If both declarations give a tag declaration a typedef name for linkage
    // purposes, then they declare the same entity.
    if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
        Decl->getAnonDeclWithTypedefName())
      continue;
  }

  Filter.erase();
}

Filter.done();
2244}

2246bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
QualType OldType;
if (TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Old))
  OldType = OldTypedef->getUnderlyingType();
else
  OldType = Context.getTypeDeclType(Old);
QualType NewType = New->getUnderlyingType();

if (NewType->isVariablyModifiedType()) {
  // Must not redefine a typedef with a variably-modified type.
  int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
  Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
    << Kind << NewType;
  if (Old->getLocation().isValid())
    notePreviousDefinition(Old, New->getLocation());
  New->setInvalidDecl();
  return true;
}

if (OldType != NewType &&
    !OldType->isDependentType() &&
    !NewType->isDependentType() &&
    !Context.hasSameType(OldType, NewType)) {
  int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
  Diag(New->getLocation(), diag::err_redefinition_different_typedef)
    << Kind << NewType << OldType;
  if (Old->getLocation().isValid())
    notePreviousDefinition(Old, New->getLocation());
  New->setInvalidDecl();
  return true;
}
return false;
2278}

2280/// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the
2281/// same name and scope as a previous declaration 'Old'.  Figure out
2282/// how to resolve this situation, merging decls or emitting
2283/// diagnostics as appropriate. If there was an error, set New to be invalid.
2284///
2285void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
                              LookupResult &OldDecls) {
// If the new decl is known invalid already, don't bother doing any
// merging checks.
if (New->isInvalidDecl()) return;

// Allow multiple definitions for ObjC built-in typedefs.
// FIXME: Verify the underlying types are equivalent!
if (getLangOpts().ObjC) {
  const IdentifierInfo *TypeID = New->getIdentifier();
  switch (TypeID->getLength()) {
  default: break;
  case 2:
    {
      if (!TypeID->isStr("id"))
        break;
      QualType T = New->getUnderlyingType();
      if (!T->isPointerType())
        break;
      if (!T->isVoidPointerType()) {
        QualType PT = T->castAs<PointerType>()->getPointeeType();
        if (!PT->isStructureType())
          break;
      }
      Context.setObjCIdRedefinitionType(T);
      // Install the built-in type for 'id', ignoring the current definition.
      New->setTypeForDecl(Context.getObjCIdType().getTypePtr());
      return;
    }
  case 5:
    if (!TypeID->isStr("Class"))
      break;
    Context.setObjCClassRedefinitionType(New->getUnderlyingType());
    // Install the built-in type for 'Class', ignoring the current definition.
    New->setTypeForDecl(Context.getObjCClassType().getTypePtr());
    return;
  case 3:
    if (!TypeID->isStr("SEL"))
      break;
    Context.setObjCSelRedefinitionType(New->getUnderlyingType());
    // Install the built-in type for 'SEL', ignoring the current definition.
    New->setTypeForDecl(Context.getObjCSelType().getTypePtr());
    return;
  }
  // Fall through - the typedef name was not a builtin type.
}

// Verify the old decl was also a type.
TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
if (!Old) {
  Diag(New->getLocation(), diag::err_redefinition_different_kind)
    << New->getDeclName();

  NamedDecl *OldD = OldDecls.getRepresentativeDecl();
  if (OldD->getLocation().isValid())
    notePreviousDefinition(OldD, New->getLocation());

  return New->setInvalidDecl();
}

// If the old declaration is invalid, just give up here.
if (Old->isInvalidDecl())
  return New->setInvalidDecl();

if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
  auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
  auto *NewTag = New->getAnonDeclWithTypedefName();
  NamedDecl *Hidden = nullptr;
  if (OldTag && NewTag &&
      OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
      !hasVisibleDefinition(OldTag, &Hidden)) {
    // There is a definition of this tag, but it is not visible. Use it
    // instead of our tag.
    New->setTypeForDecl(OldTD->getTypeForDecl());
    if (OldTD->isModed())
      New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(),
                                  OldTD->getUnderlyingType());
    else
      New->setTypeSourceInfo(OldTD->getTypeSourceInfo());

    // Make the old tag definition visible.
    makeMergedDefinitionVisible(Hidden);

    // If this was an unscoped enumeration, yank all of its enumerators
    // out of the scope.
    if (isa<EnumDecl>(NewTag)) {
      Scope *EnumScope = getNonFieldDeclScope(S);
      for (auto *D : NewTag->decls()) {
        auto *ED = cast<EnumConstantDecl>(D);
        assert(EnumScope->isDeclScope(ED))((void)0);
        EnumScope->RemoveDecl(ED);
        IdResolver.RemoveDecl(ED);
        ED->getLexicalDeclContext()->removeDecl(ED);
      }
    }
  }
}

// If the typedef types are not identical, reject them in all languages and
// with any extensions enabled.
if (isIncompatibleTypedef(Old, New))
  return;

// The types match.  Link up the redeclaration chain and merge attributes if
// the old declaration was a typedef.
if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old)) {
  New->setPreviousDecl(Typedef);
  mergeDeclAttributes(New, Old);
}

if (getLangOpts().MicrosoftExt)
  return;

if (getLangOpts().CPlusPlus) {
  // C++ [dcl.typedef]p2:
  //   In a given non-class scope, a typedef specifier can be used to
  //   redefine the name of any type declared in that scope to refer
  //   to the type to which it already refers.
  if (!isa<CXXRecordDecl>(CurContext))
    return;

  // C++0x [dcl.typedef]p4:
  //   In a given class scope, a typedef specifier can be used to redefine
  //   any class-name declared in that scope that is not also a typedef-name
  //   to refer to the type to which it already refers.
  //
  // This wording came in via DR424, which was a correction to the
  // wording in DR56, which accidentally banned code like:
  //
  //   struct S {
  //     typedef struct A { } A;
  //   };
  //
  // in the C++03 standard. We implement the C++0x semantics, which
  // allow the above but disallow
  //
  //   struct S {
  //     typedef int I;
  //     typedef int I;
  //   };
  //
  // since that was the intent of DR56.
  if (!isa<TypedefNameDecl>(Old))
    return;

  Diag(New->getLocation(), diag::err_redefinition)
    << New->getDeclName();
  notePreviousDefinition(Old, New->getLocation());
  return New->setInvalidDecl();
}

// Modules always permit redefinition of typedefs, as does C11.
if (getLangOpts().Modules || getLangOpts().C11)
  return;

// If we have a redefinition of a typedef in C, emit a warning.  This warning
// is normally mapped to an error, but can be controlled with
// -Wtypedef-redefinition.  If either the original or the redefinition is
// in a system header, don't emit this for compatibility with GCC.
if (getDiagnostics().getSuppressSystemWarnings() &&
    // Some standard types are defined implicitly in Clang (e.g. OpenCL).
    (Old->isImplicit() ||
     Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
     Context.getSourceManager().isInSystemHeader(New->getLocation())))
  return;

Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
  << New->getDeclName();
notePreviousDefinition(Old, New->getLocation());
2454}

2456/// DeclhasAttr - returns true if decl Declaration already has the target
2457/// attribute.
2458static bool DeclHasAttr(const Decl *D, const Attr *A) {
const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
for (const auto *i : D->attrs())
  if (i->getKind() == A->getKind()) {
    if (Ann) {
      if (Ann->getAnnotation() == cast<AnnotateAttr>(i)->getAnnotation())
        return true;
      continue;
    }
    // FIXME: Don't hardcode this check
    if (OA && isa<OwnershipAttr>(i))
      return OA->getOwnKind() == cast<OwnershipAttr>(i)->getOwnKind();
    return true;
  }

return false;
2475}

2477static bool isAttributeTargetADefinition(Decl *D) {
if (VarDecl *VD = dyn_cast<VarDecl>(D))
  return VD->isThisDeclarationADefinition();
if (TagDecl *TD = dyn_cast<TagDecl>(D))
  return TD->isCompleteDefinition() || TD->isBeingDefined();
return true;
2483}

2485/// Merge alignment attributes from \p Old to \p New, taking into account the
2486/// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
2487///
2488/// \return \c true if any attributes were added to \p New.
2489static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
// Look for alignas attributes on Old, and pick out whichever attribute
// specifies the strictest alignment requirement.
AlignedAttr *OldAlignasAttr = nullptr;
AlignedAttr *OldStrictestAlignAttr = nullptr;
unsigned OldAlign = 0;
for (auto *I : Old->specific_attrs<AlignedAttr>()) {
  // FIXME: We have no way of representing inherited dependent alignments
  // in a case like:
  //   template<int A, int B> struct alignas(A) X;
  //   template<int A, int B> struct alignas(B) X {};
  // For now, we just ignore any alignas attributes which are not on the
  // definition in such a case.
  if (I->isAlignmentDependent())
    return false;

  if (I->isAlignas())
    OldAlignasAttr = I;

  unsigned Align = I->getAlignment(S.Context);
  if (Align > OldAlign) {
    OldAlign = Align;
    OldStrictestAlignAttr = I;
  }
}

// Look for alignas attributes on New.
AlignedAttr *NewAlignasAttr = nullptr;
unsigned NewAlign = 0;
for (auto *I : New->specific_attrs<AlignedAttr>()) {
  if (I->isAlignmentDependent())
    return false;

  if (I->isAlignas())
    NewAlignasAttr = I;

  unsigned Align = I->getAlignment(S.Context);
  if (Align > NewAlign)
    NewAlign = Align;
}

if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
  // Both declarations have 'alignas' attributes. We require them to match.
  // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
  // fall short. (If two declarations both have alignas, they must both match
  // every definition, and so must match each other if there is a definition.)

  // If either declaration only contains 'alignas(0)' specifiers, then it
  // specifies the natural alignment for the type.
  if (OldAlign == 0 || NewAlign == 0) {
    QualType Ty;
    if (ValueDecl *VD = dyn_cast<ValueDecl>(New))
      Ty = VD->getType();
    else
      Ty = S.Context.getTagDeclType(cast<TagDecl>(New));

    if (OldAlign == 0)
      OldAlign = S.Context.getTypeAlign(Ty);
    if (NewAlign == 0)
      NewAlign = S.Context.getTypeAlign(Ty);
  }

  if (OldAlign != NewAlign) {
    S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch)
      << (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity()
      << (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity();
    S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration);
  }
}

if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) {
  // C++11 [dcl.align]p6:
  //   if any declaration of an entity has an alignment-specifier,
  //   every defining declaration of that entity shall specify an
  //   equivalent alignment.
  // C11 6.7.5/7:
  //   If the definition of an object does not have an alignment
  //   specifier, any other declaration of that object shall also
  //   have no alignment specifier.
  S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition)
    << OldAlignasAttr;
  S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration)
    << OldAlignasAttr;
}

bool AnyAdded = false;

// Ensure we have an attribute representing the strictest alignment.
if (OldAlign > NewAlign) {
  AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context);
  Clone->setInherited(true);
  New->addAttr(Clone);
  AnyAdded = true;
}

// Ensure we have an alignas attribute if the old declaration had one.
if (OldAlignasAttr && !NewAlignasAttr &&
    !(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
  AlignedAttr *Clone = OldAlignasAttr->clone(S.Context);
  Clone->setInherited(true);
  New->addAttr(Clone);
  AnyAdded = true;
}

return AnyAdded;
2594}

2596#define WANT_DECL_MERGE_LOGIC
2597#include "clang/Sema/AttrParsedAttrImpl.inc"
2598#undef WANT_DECL_MERGE_LOGIC

2600static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
                             const InheritableAttr *Attr,
                             Sema::AvailabilityMergeKind AMK) {
// Diagnose any mutual exclusions between the attribute that we want to add
// and attributes that already exist on the declaration.
if (!DiagnoseMutualExclusions(S, D, Attr))
  return false;

// This function copies an attribute Attr from a previous declaration to the
// new declaration D if the new declaration doesn't itself have that attribute
// yet or if that attribute allows duplicates.
// If you're adding a new attribute that requires logic different from
// "use explicit attribute on decl if present, else use attribute from
// previous decl", for example if the attribute needs to be consistent
// between redeclarations, you need to call a custom merge function here.
InheritableAttr *NewAttr = nullptr;
if (const auto *AA = dyn_cast<AvailabilityAttr>(Attr))
  NewAttr = S.mergeAvailabilityAttr(
      D, *AA, AA->getPlatform(), AA->isImplicit(), AA->getIntroduced(),
      AA->getDeprecated(), AA->getObsoleted(), AA->getUnavailable(),
      AA->getMessage(), AA->getStrict(), AA->getReplacement(), AMK,
      AA->getPriority());
else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
  NewAttr = S.mergeVisibilityAttr(D, *VA, VA->getVisibility());
else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
  NewAttr = S.mergeTypeVisibilityAttr(D, *VA, VA->getVisibility());
else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Attr))
  NewAttr = S.mergeDLLImportAttr(D, *ImportA);
else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Attr))
  NewAttr = S.mergeDLLExportAttr(D, *ExportA);
else if (const auto *FA = dyn_cast<FormatAttr>(Attr))
  NewAttr = S.mergeFormatAttr(D, *FA, FA->getType(), FA->getFormatIdx(),
                              FA->getFirstArg());
else if (const auto *SA = dyn_cast<SectionAttr>(Attr))
  NewAttr = S.mergeSectionAttr(D, *SA, SA->getName());
else if (const auto *CSA = dyn_cast<CodeSegAttr>(Attr))
  NewAttr = S.mergeCodeSegAttr(D, *CSA, CSA->getName());
else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Attr))
  NewAttr = S.mergeMSInheritanceAttr(D, *IA, IA->getBestCase(),
                                     IA->getInheritanceModel());
else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Attr))
  NewAttr = S.mergeAlwaysInlineAttr(D, *AA,
                                    &S.Context.Idents.get(AA->getSpelling()));
else if (S.getLangOpts().CUDA && isa<FunctionDecl>(D) &&
         (isa<CUDAHostAttr>(Attr) || isa<CUDADeviceAttr>(Attr) ||
          isa<CUDAGlobalAttr>(Attr))) {
  // CUDA target attributes are part of function signature for
  // overloading purposes and must not be merged.
  return false;
} else if (const auto *MA = dyn_cast<MinSizeAttr>(Attr))
  NewAttr = S.mergeMinSizeAttr(D, *MA);
else if (const auto *SNA = dyn_cast<SwiftNameAttr>(Attr))
  NewAttr = S.mergeSwiftNameAttr(D, *SNA, SNA->getName());
else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Attr))
  NewAttr = S.mergeOptimizeNoneAttr(D, *OA);
else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Attr))
  NewAttr = S.mergeInternalLinkageAttr(D, *InternalLinkageA);
else if (isa<AlignedAttr>(Attr))
  // AlignedAttrs are handled separately, because we need to handle all
  // such attributes on a declaration at the same time.
  NewAttr = nullptr;
else if ((isa<DeprecatedAttr>(Attr) || isa<UnavailableAttr>(Attr)) &&
         (AMK == Sema::AMK_Override ||
          AMK == Sema::AMK_ProtocolImplementation ||
          AMK == Sema::AMK_OptionalProtocolImplementation))
  NewAttr = nullptr;
else if (const auto *UA = dyn_cast<UuidAttr>(Attr))
  NewAttr = S.mergeUuidAttr(D, *UA, UA->getGuid(), UA->getGuidDecl());
else if (const auto *IMA = dyn_cast<WebAssemblyImportModuleAttr>(Attr))
  NewAttr = S.mergeImportModuleAttr(D, *IMA);
else if (const auto *INA = dyn_cast<WebAssemblyImportNameAttr>(Attr))
  NewAttr = S.mergeImportNameAttr(D, *INA);
else if (const auto *TCBA = dyn_cast<EnforceTCBAttr>(Attr))
  NewAttr = S.mergeEnforceTCBAttr(D, *TCBA);
else if (const auto *TCBLA = dyn_cast<EnforceTCBLeafAttr>(Attr))
  NewAttr = S.mergeEnforceTCBLeafAttr(D, *TCBLA);
else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr))
  NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));

if (NewAttr) {
  NewAttr->setInherited(true);
  D->addAttr(NewAttr);
  if (isa<MSInheritanceAttr>(NewAttr))
    S.Consumer.AssignInheritanceModel(cast<CXXRecordDecl>(D));
  return true;
}

return false;
2688}

2690static const NamedDecl *getDefinition(const Decl *D) {
if (const TagDecl *TD = dyn_cast<TagDecl>(D))
  return TD->getDefinition();
if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
  const VarDecl *Def = VD->getDefinition();
  if (Def)
    return Def;
  return VD->getActingDefinition();
}
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
  const FunctionDecl *Def = nullptr;
  if (FD->isDefined(Def, true))
    return Def;
}
return nullptr;
2705}

2707static bool hasAttribute(const Decl *D, attr::Kind Kind) {
for (const auto *Attribute : D->attrs())
  if (Attribute->getKind() == Kind)
    return true;
return false;
2712}

2714/// checkNewAttributesAfterDef - If we already have a definition, check that
2715/// there are no new attributes in this declaration.
2716static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
if (!New->hasAttrs())
  return;

const NamedDecl *Def = getDefinition(Old);
if (!Def || Def == New)
  return;

AttrVec &NewAttributes = New->getAttrs();
for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
  const Attr *NewAttribute = NewAttributes[I];

  if (isa<AliasAttr>(NewAttribute) || isa<IFuncAttr>(NewAttribute)) {
    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New)) {
      Sema::SkipBodyInfo SkipBody;
      S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def), &SkipBody);

      // If we're skipping this definition, drop the "alias" attribute.
      if (SkipBody.ShouldSkip) {
        NewAttributes.erase(NewAttributes.begin() + I);
        --E;
        continue;
      }
    } else {
      VarDecl *VD = cast<VarDecl>(New);
      unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
                              VarDecl::TentativeDefinition
                          ? diag::err_alias_after_tentative
                          : diag::err_redefinition;
      S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
      if (Diag == diag::err_redefinition)
        S.notePreviousDefinition(Def, VD->getLocation());
      else
        S.Diag(Def->getLocation(), diag::note_previous_definition);
      VD->setInvalidDecl();
    }
    ++I;
    continue;
  }

  if (const VarDecl *VD = dyn_cast<VarDecl>(Def)) {
    // Tentative definitions are only interesting for the alias check above.
    if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
      ++I;
      continue;
    }
  }

  if (hasAttribute(Def, NewAttribute->getKind())) {
    ++I;
    continue; // regular attr merging will take care of validating this.
  }

  if (isa<C11NoReturnAttr>(NewAttribute)) {
    // C's _Noreturn is allowed to be added to a function after it is defined.
    ++I;
    continue;
  } else if (isa<UuidAttr>(NewAttribute)) {
    // msvc will allow a subsequent definition to add an uuid to a class
    ++I;
    continue;
  } else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(NewAttribute)) {
    if (AA->isAlignas()) {
      // C++11 [dcl.align]p6:
      //   if any declaration of an entity has an alignment-specifier,
      //   every defining declaration of that entity shall specify an
      //   equivalent alignment.
      // C11 6.7.5/7:
      //   If the definition of an object does not have an alignment
      //   specifier, any other declaration of that object shall also
      //   have no alignment specifier.
      S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition)
        << AA;
      S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration)
        << AA;
      NewAttributes.erase(NewAttributes.begin() + I);
      --E;
      continue;
    }
  } else if (isa<LoaderUninitializedAttr>(NewAttribute)) {
    // If there is a C definition followed by a redeclaration with this
    // attribute then there are two different definitions. In C++, prefer the
    // standard diagnostics.
    if (!S.getLangOpts().CPlusPlus) {
      S.Diag(NewAttribute->getLocation(),
             diag::err_loader_uninitialized_redeclaration);
      S.Diag(Def->getLocation(), diag::note_previous_definition);
      NewAttributes.erase(NewAttributes.begin() + I);
      --E;
      continue;
    }
  } else if (isa<SelectAnyAttr>(NewAttribute) &&
             cast<VarDecl>(New)->isInline() &&
             !cast<VarDecl>(New)->isInlineSpecified()) {
    // Don't warn about applying selectany to implicitly inline variables.
    // Older compilers and language modes would require the use of selectany
    // to make such variables inline, and it would have no effect if we
    // honored it.
    ++I;
    continue;
  } else if (isa<OMPDeclareVariantAttr>(NewAttribute)) {
    // We allow to add OMP[Begin]DeclareVariantAttr to be added to
    // declarations after defintions.
    ++I;
    continue;
  }

  S.Diag(NewAttribute->getLocation(),
         diag::warn_attribute_precede_definition);
  S.Diag(Def->getLocation(), diag::note_previous_definition);
  NewAttributes.erase(NewAttributes.begin() + I);
  --E;
}
2829}

2831static void diagnoseMissingConstinit(Sema &S, const VarDecl *InitDecl,
                                   const ConstInitAttr *CIAttr,
                                   bool AttrBeforeInit) {
SourceLocation InsertLoc = InitDecl->getInnerLocStart();

// Figure out a good way to write this specifier on the old declaration.
// FIXME: We should just use the spelling of CIAttr, but we don't preserve
// enough of the attribute list spelling information to extract that without
// heroics.
std::string SuitableSpelling;
if (S.getLangOpts().CPlusPlus20)
  SuitableSpelling = std::string(
      S.PP.getLastMacroWithSpelling(InsertLoc, {tok::kw_constinit}));
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
  SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
      InsertLoc, {tok::l_square, tok::l_square,
                  S.PP.getIdentifierInfo("clang"), tok::coloncolon,
                  S.PP.getIdentifierInfo("require_constant_initialization"),
                  tok::r_square, tok::r_square}));
if (SuitableSpelling.empty())
  SuitableSpelling = std::string(S.PP.getLastMacroWithSpelling(
      InsertLoc, {tok::kw___attribute, tok::l_paren, tok::r_paren,
                  S.PP.getIdentifierInfo("require_constant_initialization"),
                  tok::r_paren, tok::r_paren}));
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus20)
  SuitableSpelling = "constinit";
if (SuitableSpelling.empty() && S.getLangOpts().CPlusPlus11)
  SuitableSpelling = "[[clang::require_constant_initialization]]";
if (SuitableSpelling.empty())
  SuitableSpelling = "__attribute__((require_constant_initialization))";
SuitableSpelling += " ";

if (AttrBeforeInit) {
  // extern constinit int a;
  // int a = 0; // error (missing 'constinit'), accepted as extension
  assert(CIAttr->isConstinit() && "should not diagnose this for attribute")((void)0);
  S.Diag(InitDecl->getLocation(), diag::ext_constinit_missing)
      << InitDecl << FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
  S.Diag(CIAttr->getLocation(), diag::note_constinit_specified_here);
} else {
  // int a = 0;
  // constinit extern int a; // error (missing 'constinit')
  S.Diag(CIAttr->getLocation(),
         CIAttr->isConstinit() ? diag::err_constinit_added_too_late
                               : diag::warn_require_const_init_added_too_late)
      << FixItHint::CreateRemoval(SourceRange(CIAttr->getLocation()));
  S.Diag(InitDecl->getLocation(), diag::note_constinit_missing_here)
      << CIAttr->isConstinit()
      << FixItHint::CreateInsertion(InsertLoc, SuitableSpelling);
}
2881}

2883/// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
2884void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
                             AvailabilityMergeKind AMK) {
if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
  UsedAttr *NewAttr = OldAttr->clone(Context);
  NewAttr->setInherited(true);
  New->addAttr(NewAttr);
}
if (RetainAttr *OldAttr = Old->getMostRecentDecl()->getAttr<RetainAttr>()) {
  RetainAttr *NewAttr = OldAttr->clone(Context);
  NewAttr->setInherited(true);
  New->addAttr(NewAttr);
}

if (!Old->hasAttrs() && !New->hasAttrs())
  return;

// [dcl.constinit]p1:
//   If the [constinit] specifier is applied to any declaration of a
//   variable, it shall be applied to the initializing declaration.
const auto *OldConstInit = Old->getAttr<ConstInitAttr>();
const auto *NewConstInit = New->getAttr<ConstInitAttr>();
if (bool(OldConstInit) != bool(NewConstInit)) {
  const auto *OldVD = cast<VarDecl>(Old);
  auto *NewVD = cast<VarDecl>(New);

  // Find the initializing declaration. Note that we might not have linked
  // the new declaration into the redeclaration chain yet.
  const VarDecl *InitDecl = OldVD->getInitializingDeclaration();
  if (!InitDecl &&
      (NewVD->hasInit() || NewVD->isThisDeclarationADefinition()))
    InitDecl = NewVD;

  if (InitDecl == NewVD) {
    // This is the initializing declaration. If it would inherit 'constinit',
    // that's ill-formed. (Note that we do not apply this to the attribute
    // form).
    if (OldConstInit && OldConstInit->isConstinit())
      diagnoseMissingConstinit(*this, NewVD, OldConstInit,
                               /*AttrBeforeInit=*/true);
  } else if (NewConstInit) {
    // This is the first time we've been told that this declaration should
    // have a constant initializer. If we already saw the initializing
    // declaration, this is too late.
    if (InitDecl && InitDecl != NewVD) {
      diagnoseMissingConstinit(*this, InitDecl, NewConstInit,
                               /*AttrBeforeInit=*/false);
      NewVD->dropAttr<ConstInitAttr>();
    }
  }
}

// Attributes declared post-definition are currently ignored.
checkNewAttributesAfterDef(*this, New, Old);

if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
  if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
    if (!OldA->isEquivalent(NewA)) {
      // This redeclaration changes __asm__ label.
      Diag(New->getLocation(), diag::err_different_asm_label);
      Diag(OldA->getLocation(), diag::note_previous_declaration);
    }
  } else if (Old->isUsed()) {
    // This redeclaration adds an __asm__ label to a declaration that has
    // already been ODR-used.
    Diag(New->getLocation(), diag::err_late_asm_label_name)
      << isa<FunctionDecl>(Old) << New->getAttr<AsmLabelAttr>()->getRange();
  }
}

// Re-declaration cannot add abi_tag's.
if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
  if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
    for (const auto &NewTag : NewAbiTagAttr->tags()) {
      if (std::find(OldAbiTagAttr->tags_begin(), OldAbiTagAttr->tags_end(),
                    NewTag) == OldAbiTagAttr->tags_end()) {
        Diag(NewAbiTagAttr->getLocation(),
             diag::err_new_abi_tag_on_redeclaration)
            << NewTag;
        Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration);
      }
    }
  } else {
    Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration);
    Diag(Old->getLocation(), diag::note_previous_declaration);
  }
}

// This redeclaration adds a section attribute.
if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
  if (auto *VD = dyn_cast<VarDecl>(New)) {
    if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
      Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
      Diag(Old->getLocation(), diag::note_previous_declaration);
    }
  }
}

// Redeclaration adds code-seg attribute.
const auto *NewCSA = New->getAttr<CodeSegAttr>();
if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
    !NewCSA->isImplicit() && isa<CXXMethodDecl>(New)) {
  Diag(New->getLocation(), diag::warn_mismatched_section)
       << 0 /*codeseg*/;
  Diag(Old->getLocation(), diag::note_previous_declaration);
}

if (!Old->hasAttrs())
  return;

bool foundAny = New->hasAttrs();

// Ensure that any moving of objects within the allocated map is done before
// we process them.
if (!foundAny) New->setAttrs(AttrVec());

for (auto *I : Old->specific_attrs<InheritableAttr>()) {
  // Ignore deprecated/unavailable/availability attributes if requested.
  AvailabilityMergeKind LocalAMK = AMK_None;
  if (isa<DeprecatedAttr>(I) ||
      isa<UnavailableAttr>(I) ||
      isa<AvailabilityAttr>(I)) {
    switch (AMK) {
    case AMK_None:
      continue;

    case AMK_Redeclaration:
    case AMK_Override:
    case AMK_ProtocolImplementation:
    case AMK_OptionalProtocolImplementation:
      LocalAMK = AMK;
      break;
    }
  }

  // Already handled.
  if (isa<UsedAttr>(I) || isa<RetainAttr>(I))
    continue;

  if (mergeDeclAttribute(*this, New, I, LocalAMK))
    foundAny = true;
}

if (mergeAlignedAttrs(*this, New, Old))
  foundAny = true;

if (!foundAny) New->dropAttrs();
3030}

3032/// mergeParamDeclAttributes - Copy attributes from the old parameter
3033/// to the new one.
3034static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
                                   const ParmVarDecl *oldDecl,
                                   Sema &S) {
// C++11 [dcl.attr.depend]p2:
//   The first declaration of a function shall specify the
//   carries_dependency attribute for its declarator-id if any declaration
//   of the function specifies the carries_dependency attribute.
const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
  S.Diag(CDA->getLocation(),
         diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
  // Find the first declaration of the parameter.
  // FIXME: Should we build redeclaration chains for function parameters?
  const FunctionDecl *FirstFD =
    cast<FunctionDecl>(oldDecl->getDeclContext())->getFirstDecl();
  const ParmVarDecl *FirstVD =
    FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex());
  S.Diag(FirstVD->getLocation(),
         diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
}

if (!oldDecl->hasAttrs())
  return;

bool foundAny = newDecl->hasAttrs();

// Ensure that any moving of objects within the allocated map is
// done before we process them.
if (!foundAny) newDecl->setAttrs(AttrVec());

for (const auto *I : oldDecl->specific_attrs<InheritableParamAttr>()) {
  if (!DeclHasAttr(newDecl, I)) {
    InheritableAttr *newAttr =
      cast<InheritableParamAttr>(I->clone(S.Context));
    newAttr->setInherited(true);
    newDecl->addAttr(newAttr);
    foundAny = true;
  }
}

if (!foundAny) newDecl->dropAttrs();
3075}

3077static void mergeParamDeclTypes(ParmVarDecl *NewParam,
                              const ParmVarDecl *OldParam,
                              Sema &S) {
if (auto Oldnullability = OldParam->getType()->getNullability(S.Context)) {
  if (auto Newnullability = NewParam->getType()->getNullability(S.Context)) {
    if (*Oldnullability != *Newnullability) {
      S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr)
        << DiagNullabilityKind(
             *Newnullability,
             ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
              != 0))
        << DiagNullabilityKind(
             *Oldnullability,
             ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
              != 0));
      S.Diag(OldParam->getLocation(), diag::note_previous_declaration);
    }
  } else {
    QualType NewT = NewParam->getType();
    NewT = S.Context.getAttributedType(
                       AttributedType::getNullabilityAttrKind(*Oldnullability),
                       NewT, NewT);
    NewParam->setType(NewT);
  }
}
3102}

3104namespace {

3106/// Used in MergeFunctionDecl to keep track of function parameters in
3107/// C.
3108struct GNUCompatibleParamWarning {
ParmVarDecl *OldParm;
ParmVarDecl *NewParm;
QualType PromotedType;
3112};

3114} // end anonymous namespace

3116// Determine whether the previous declaration was a definition, implicit
3117// declaration, or a declaration.
3118template <typename T>
3119static std::pair<diag::kind, SourceLocation>
3120getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
diag::kind PrevDiag;
SourceLocation OldLocation = Old->getLocation();
if (Old->isThisDeclarationADefinition())
  PrevDiag = diag::note_previous_definition;
else if (Old->isImplicit()) {
  PrevDiag = diag::note_previous_implicit_declaration;
  if (OldLocation.isInvalid())
    OldLocation = New->getLocation();
} else
  PrevDiag = diag::note_previous_declaration;
return std::make_pair(PrevDiag, OldLocation);
3132}

3134/// canRedefineFunction - checks if a function can be redefined. Currently,
3135/// only extern inline functions can be redefined, and even then only in
3136/// GNU89 mode.
3137static bool canRedefineFunction(const FunctionDecl *FD,
                              const LangOptions& LangOpts) {
return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
        !LangOpts.CPlusPlus &&
        FD->isInlineSpecified() &&
        FD->getStorageClass() == SC_Extern);
3143}

3145const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
const AttributedType *AT = T->getAs<AttributedType>();
while (AT && !AT->isCallingConv())
  AT = AT->getModifiedType()->getAs<AttributedType>();
return AT;
3150}

3152template <typename T>
3153static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
const DeclContext *DC = Old->getDeclContext();
if (DC->isRecord())
  return false;

LanguageLinkage OldLinkage = Old->getLanguageLinkage();
if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
  return true;
if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
  return true;
return false;
3164}

3166template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
3167static bool isExternC(VarTemplateDecl *) { return false; }
3168static bool isExternC(FunctionTemplateDecl *) { return false; }

3170/// Check whether a redeclaration of an entity introduced by a
3171/// using-declaration is valid, given that we know it's not an overload
3172/// (nor a hidden tag declaration).
3173template<typename ExpectedDecl>
3174static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
                                 ExpectedDecl *New) {
// C++11 [basic.scope.declarative]p4:
//   Given a set of declarations in a single declarative region, each of
//   which specifies the same unqualified name,
//   -- they shall all refer to the same entity, or all refer to functions
//      and function templates; or
//   -- exactly one declaration shall declare a class name or enumeration
//      name that is not a typedef name and the other declarations shall all
//      refer to the same variable or enumerator, or all refer to functions
//      and function templates; in this case the class name or enumeration
//      name is hidden (3.3.10).

// C++11 [namespace.udecl]p14:
//   If a function declaration in namespace scope or block scope has the
//   same name and the same parameter-type-list as a function introduced
//   by a using-declaration, and the declarations do not declare the same
//   function, the program is ill-formed.

auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
if (Old &&
    !Old->getDeclContext()->getRedeclContext()->Equals(
        New->getDeclContext()->getRedeclContext()) &&
    !(isExternC(Old) && isExternC(New)))
  Old = nullptr;

if (!Old) {
  S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
  S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target);
  S.Diag(OldS->getIntroducer()->getLocation(), diag::note_using_decl) << 0;
  return true;
}
return false;
3207}

3209static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
                                          const FunctionDecl *B) {
assert(A->getNumParams() == B->getNumParams())((void)0);

auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
  const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
  const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
  if (AttrA == AttrB)
    return true;
  return AttrA && AttrB && AttrA->getType() == AttrB->getType() &&
         AttrA->isDynamic() == AttrB->isDynamic();
};

return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
3223}

3225/// If necessary, adjust the semantic declaration context for a qualified
3226/// declaration to name the correct inline namespace within the qualifier.
3227static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
                                             DeclaratorDecl *OldD) {
// The only case where we need to update the DeclContext is when
// redeclaration lookup for a qualified name finds a declaration
// in an inline namespace within the context named by the qualifier:
//
//   inline namespace N { int f(); }
//   int ::f(); // Sema DC needs adjusting from :: to N::.
//
// For unqualified declarations, the semantic context *can* change
// along the redeclaration chain (for local extern declarations,
// extern "C" declarations, and friend declarations in particular).
if (!NewD->getQualifier())
  return;

// NewD is probably already in the right context.
auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
if (NamedDC->Equals(SemaDC))
  return;

assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||((void)0)
        NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&((void)0)
       "unexpected context for redeclaration")((void)0);

auto *LexDC = NewD->getLexicalDeclContext();
auto FixSemaDC = [=](NamedDecl *D) {
  if (!D)
    return;
  D->setDeclContext(SemaDC);
  D->setLexicalDeclContext(LexDC);
};

FixSemaDC(NewD);
if (auto *FD = dyn_cast<FunctionDecl>(NewD))
  FixSemaDC(FD->getDescribedFunctionTemplate());
else if (auto *VD = dyn_cast<VarDecl>(NewD))
  FixSemaDC(VD->getDescribedVarTemplate());
3265}

3267/// MergeFunctionDecl - We just parsed a function 'New' from
3268/// declarator D which has the same name and scope as a previous
3269/// declaration 'Old'.  Figure out how to resolve this situation,
3270/// merging decls or emitting diagnostics as appropriate.
3271///
3272/// In C++, New and Old must be declarations that are not
3273/// overloaded. Use IsOverload to determine whether New and Old are
3274/// overloaded, and to select the Old declaration that New should be
3275/// merged with.
3276///
3277/// Returns true if there was an error, false otherwise.
3278bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
                           Scope *S, bool MergeTypeWithOld) {
// Verify the old decl was also a function.
FunctionDecl *Old = OldD->getAsFunction();
if (!Old) {
  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) {
    if (New->getFriendObjectKind()) {
      Diag(New->getLocation(), diag::err_using_decl_friend);
      Diag(Shadow->getTargetDecl()->getLocation(),
           diag::note_using_decl_target);
      Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl)
          << 0;
      return true;
    }

    // Check whether the two declarations might declare the same function or
    // function template.
    if (FunctionTemplateDecl *NewTemplate =
            New->getDescribedFunctionTemplate()) {
      if (checkUsingShadowRedecl<FunctionTemplateDecl>(*this, Shadow,
                                                       NewTemplate))
        return true;
      OldD = Old = cast<FunctionTemplateDecl>(Shadow->getTargetDecl())
                       ->getAsFunction();
    } else {
      if (checkUsingShadowRedecl<FunctionDecl>(*this, Shadow, New))
        return true;
      OldD = Old = cast<FunctionDecl>(Shadow->getTargetDecl());
    }
  } else {
    Diag(New->getLocation(), diag::err_redefinition_different_kind)
      << New->getDeclName();
    notePreviousDefinition(OldD, New->getLocation());
    return true;
  }
}

// If the old declaration was found in an inline namespace and the new
// declaration was qualified, update the DeclContext to match.
adjustDeclContextForDeclaratorDecl(New, Old);

// If the old declaration is invalid, just give up here.
if (Old->isInvalidDecl())
  return true;

// Disallow redeclaration of some builtins.
if (!getASTContext().canBuiltinBeRedeclared(Old)) {
  Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName();
  Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
      << Old << Old->getType();
  return true;
}

diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation) =
    getNoteDiagForInvalidRedeclaration(Old, New);

// Don't complain about this if we're in GNU89 mode and the old function
// is an extern inline function.
// Don't complain about specializations. They are not supposed to have
// storage classes.
if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
    New->getStorageClass() == SC_Static &&
    Old->hasExternalFormalLinkage() &&
    !New->getTemplateSpecializationInfo() &&
    !canRedefineFunction(Old, getLangOpts())) {
  if (getLangOpts().MicrosoftExt) {
    Diag(New->getLocation(), diag::ext_static_non_static) << New;
    Diag(OldLocation, PrevDiag);
  } else {
    Diag(New->getLocation(), diag::err_static_non_static) << New;
    Diag(OldLocation, PrevDiag);
    return true;
  }
}

if (New->hasAttr<InternalLinkageAttr>() &&
    !Old->hasAttr<InternalLinkageAttr>()) {
  Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
      << New->getDeclName();
  notePreviousDefinition(Old, New->getLocation());
  New->dropAttr<InternalLinkageAttr>();
}

if (CheckRedeclarationModuleOwnership(New, Old))
  return true;

if (!getLangOpts().CPlusPlus) {
  bool OldOvl = Old->hasAttr<OverloadableAttr>();
  if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
    Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch)
      << New << OldOvl;

    // Try our best to find a decl that actually has the overloadable
    // attribute for the note. In most cases (e.g. programs with only one
    // broken declaration/definition), this won't matter.
    //
    // FIXME: We could do this if we juggled some extra state in
    // OverloadableAttr, rather than just removing it.
    const Decl *DiagOld = Old;
    if (OldOvl) {
      auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) {
        const auto *A = D->getAttr<OverloadableAttr>();
        return A && !A->isImplicit();
      });
      // If we've implicitly added *all* of the overloadable attrs to this
      // chain, emitting a "previous redecl" note is pointless.
      DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
    }

    if (DiagOld)
      Diag(DiagOld->getLocation(),
           diag::note_attribute_overloadable_prev_overload)
        << OldOvl;

    if (OldOvl)
      New->addAttr(OverloadableAttr::CreateImplicit(Context));
    else
      New->dropAttr<OverloadableAttr>();
  }
}

// If a function is first declared with a calling convention, but is later
// declared or defined without one, all following decls assume the calling
// convention of the first.
//
// It's OK if a function is first declared without a calling convention,
// but is later declared or defined with the default calling convention.
//
// To test if either decl has an explicit calling convention, we look for
// AttributedType sugar nodes on the type as written.  If they are missing or
// were canonicalized away, we assume the calling convention was implicit.
//
// Note also that we DO NOT return at this point, because we still have
// other tests to run.
QualType OldQType = Context.getCanonicalType(Old->getType());
QualType NewQType = Context.getCanonicalType(New->getType());
const FunctionType *OldType = cast<FunctionType>(OldQType);
const FunctionType *NewType = cast<FunctionType>(NewQType);
FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
bool RequiresAdjustment = false;

if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
  FunctionDecl *First = Old->getFirstDecl();
  const FunctionType *FT =
      First->getType().getCanonicalType()->castAs<FunctionType>();
  FunctionType::ExtInfo FI = FT->getExtInfo();
  bool NewCCExplicit = getCallingConvAttributedType(New->getType());
  if (!NewCCExplicit) {
    // Inherit the CC from the previous declaration if it was specified
    // there but not here.
    NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
    RequiresAdjustment = true;
  } else if (Old->getBuiltinID()) {
    // Builtin attribute isn't propagated to the new one yet at this point,
    // so we check if the old one is a builtin.

    // Calling Conventions on a Builtin aren't really useful and setting a
    // default calling convention and cdecl'ing some builtin redeclarations is
    // common, so warn and ignore the calling convention on the redeclaration.
    Diag(New->getLocation(), diag::warn_cconv_unsupported)
        << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
        << (int)CallingConventionIgnoredReason::BuiltinFunction;
    NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
    RequiresAdjustment = true;
  } else {
    // Calling conventions aren't compatible, so complain.
    bool FirstCCExplicit = getCallingConvAttributedType(First->getType());
    Diag(New->getLocation(), diag::err_cconv_change)
      << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
      << !FirstCCExplicit
      << (!FirstCCExplicit ? "" :
          FunctionType::getNameForCallConv(FI.getCC()));

    // Put the note on the first decl, since it is the one that matters.
    Diag(First->getLocation(), diag::note_previous_declaration);
    return true;
  }
}

// FIXME: diagnose the other way around?
if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
  NewTypeInfo = NewTypeInfo.withNoReturn(true);
  RequiresAdjustment = true;
}

// Merge regparm attribute.
if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
    OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
  if (NewTypeInfo.getHasRegParm()) {
    Diag(New->getLocation(), diag::err_regparm_mismatch)
      << NewType->getRegParmType()
      << OldType->getRegParmType();
    Diag(OldLocation, diag::note_previous_declaration);
    return true;
  }

  NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm());
  RequiresAdjustment = true;
}

// Merge ns_returns_retained attribute.
if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
  if (NewTypeInfo.getProducesResult()) {
    Diag(New->getLocation(), diag::err_function_attribute_mismatch)
        << "'ns_returns_retained'";
    Diag(OldLocation, diag::note_previous_declaration);
    return true;
  }

  NewTypeInfo = NewTypeInfo.withProducesResult(true);
  RequiresAdjustment = true;
}

if (OldTypeInfo.getNoCallerSavedRegs() !=
    NewTypeInfo.getNoCallerSavedRegs()) {
  if (NewTypeInfo.getNoCallerSavedRegs()) {
    AnyX86NoCallerSavedRegistersAttr *Attr =
      New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
    Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr;
    Diag(OldLocation, diag::note_previous_declaration);
    return true;
  }

  NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true);
  RequiresAdjustment = true;
}

if (RequiresAdjustment) {
  const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
  AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo);
  New->setType(QualType(AdjustedType, 0));
  NewQType = Context.getCanonicalType(New->getType());
}

// If this redeclaration makes the function inline, we may need to add it to
// UndefinedButUsed.
if (!Old->isInlined() && New->isInlined() &&
    !New->hasAttr<GNUInlineAttr>() &&
    !getLangOpts().GNUInline &&
    Old->isUsed(false) &&
    !Old->isDefined() && !New->isThisDeclarationADefinition())
  UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
                                         SourceLocation()));

// If this redeclaration makes it newly gnu_inline, we don't want to warn
// about it.
if (New->hasAttr<GNUInlineAttr>() &&
    Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
  UndefinedButUsed.erase(Old->getCanonicalDecl());
}

// If pass_object_size params don't match up perfectly, this isn't a valid
// redeclaration.
if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
    !hasIdenticalPassObjectSizeAttrs(Old, New)) {
  Diag(New->getLocation(), diag::err_different_pass_object_size_params)
      << New->getDeclName();
  Diag(OldLocation, PrevDiag) << Old << Old->getType();
  return true;
}

if (getLangOpts().CPlusPlus) {
  // C++1z [over.load]p2
  //   Certain function declarations cannot be overloaded:
  //     -- Function declarations that differ only in the return type,
  //        the exception specification, or both cannot be overloaded.

  // Check the exception specifications match. This may recompute the type of
  // both Old and New if it resolved exception specifications, so grab the
  // types again after this. Because this updates the type, we do this before
  // any of the other checks below, which may update the "de facto" NewQType
  // but do not necessarily update the type of New.
  if (CheckEquivalentExceptionSpec(Old, New))
    return true;
  OldQType = Context.getCanonicalType(Old->getType());
  NewQType = Context.getCanonicalType(New->getType());

  // Go back to the type source info to compare the declared return types,
  // per C++1y [dcl.type.auto]p13:
  //   Redeclarations or specializations of a function or function template
  //   with a declared return type that uses a placeholder type shall also
  //   use that placeholder, not a deduced type.
  QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
  QualType NewDeclaredReturnType = New->getDeclaredReturnType();
  if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) &&
      canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType,
                                     OldDeclaredReturnType)) {
    QualType ResQT;
    if (NewDeclaredReturnType->isObjCObjectPointerType() &&
        OldDeclaredReturnType->isObjCObjectPointerType())
      // FIXME: This does the wrong thing for a deduced return type.
      ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
    if (ResQT.isNull()) {
      if (New->isCXXClassMember() && New->isOutOfLine())
        Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type)
            << New << New->getReturnTypeSourceRange();
      else
        Diag(New->getLocation(), diag::err_ovl_diff_return_type)
            << New->getReturnTypeSourceRange();
      Diag(OldLocation, PrevDiag) << Old << Old->getType()
                                  << Old->getReturnTypeSourceRange();
      return true;
    }
    else
      NewQType = ResQT;
  }

  QualType OldReturnType = OldType->getReturnType();
  QualType NewReturnType = cast<FunctionType>(NewQType)->getReturnType();
  if (OldReturnType != NewReturnType) {
    // If this function has a deduced return type and has already been
    // defined, copy the deduced value from the old declaration.
    AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
    if (OldAT && OldAT->isDeduced()) {
      New->setType(
          SubstAutoType(New->getType(),
                        OldAT->isDependentType() ? Context.DependentTy
                                                 : OldAT->getDeducedType()));
      NewQType = Context.getCanonicalType(
          SubstAutoType(NewQType,
                        OldAT->isDependentType() ? Context.DependentTy
                                                 : OldAT->getDeducedType()));
    }
  }

  const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
  CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
  if (OldMethod && NewMethod) {
    // Preserve triviality.
    NewMethod->setTrivial(OldMethod->isTrivial());

    // MSVC allows explicit template specialization at class scope:
    // 2 CXXMethodDecls referring to the same function will be injected.
    // We don't want a redeclaration error.
    bool IsClassScopeExplicitSpecialization =
                            OldMethod->isFunctionTemplateSpecialization() &&
                            NewMethod->isFunctionTemplateSpecialization();
    bool isFriend = NewMethod->getFriendObjectKind();

    if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
        !IsClassScopeExplicitSpecialization) {
      //    -- Member function declarations with the same name and the
      //       same parameter types cannot be overloaded if any of them
      //       is a static member function declaration.
      if (OldMethod->isStatic() != NewMethod->isStatic()) {
        Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
        Diag(OldLocation, PrevDiag) << Old << Old->getType();
        return true;
      }

      // C++ [class.mem]p1:
      //   [...] A member shall not be declared twice in the
      //   member-specification, except that a nested class or member
      //   class template can be declared and then later defined.
      if (!inTemplateInstantiation()) {
        unsigned NewDiag;
        if (isa<CXXConstructorDecl>(OldMethod))
          NewDiag = diag::err_constructor_redeclared;
        else if (isa<CXXDestructorDecl>(NewMethod))
          NewDiag = diag::err_destructor_redeclared;
        else if (isa<CXXConversionDecl>(NewMethod))
          NewDiag = diag::err_conv_function_redeclared;
        else
          NewDiag = diag::err_member_redeclared;

        Diag(New->getLocation(), NewDiag);
      } else {
        Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation)
          << New << New->getType();
      }
      Diag(OldLocation, PrevDiag) << Old << Old->getType();
      return true;

    // Complain if this is an explicit declaration of a special
    // member that was initially declared implicitly.
    //
    // As an exception, it's okay to befriend such methods in order
    // to permit the implicit constructor/destructor/operator calls.
    } else if (OldMethod->isImplicit()) {
      if (isFriend) {
        NewMethod->setImplicit();
      } else {
        Diag(NewMethod->getLocation(),
             diag::err_definition_of_implicitly_declared_member)
          << New << getSpecialMember(OldMethod);
        return true;
      }
    } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
      Diag(NewMethod->getLocation(),
           diag::err_definition_of_explicitly_defaulted_member)
        << getSpecialMember(OldMethod);
      return true;
    }
  }

  // C++11 [dcl.attr.noreturn]p1:
  //   The first declaration of a function shall specify the noreturn
  //   attribute if any declaration of that function specifies the noreturn
  //   attribute.
  const CXX11NoReturnAttr *NRA = New->getAttr<CXX11NoReturnAttr>();
  if (NRA && !Old->hasAttr<CXX11NoReturnAttr>()) {
    Diag(NRA->getLocation(), diag::err_noreturn_missing_on_first_decl);
    Diag(Old->getFirstDecl()->getLocation(),
         diag::note_noreturn_missing_first_decl);
  }

  // C++11 [dcl.attr.depend]p2:
  //   The first declaration of a function shall specify the
  //   carries_dependency attribute for its declarator-id if any declaration
  //   of the function specifies the carries_dependency attribute.
  const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
  if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
    Diag(CDA->getLocation(),
         diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
    Diag(Old->getFirstDecl()->getLocation(),
         diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
  }

  // (C++98 8.3.5p3):
  //   All declarations for a function shall agree exactly in both the
  //   return type and the parameter-type-list.
  // We also want to respect all the extended bits except noreturn.

  // noreturn should now match unless the old type info didn't have it.
  QualType OldQTypeForComparison = OldQType;
  if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
    auto *OldType = OldQType->castAs<FunctionProtoType>();
    const FunctionType *OldTypeForComparison
      = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
    OldQTypeForComparison = QualType(OldTypeForComparison, 0);
    assert(OldQTypeForComparison.isCanonical())((void)0);
  }

  if (haveIncompatibleLanguageLinkages(Old, New)) {
    // As a special case, retain the language linkage from previous
    // declarations of a friend function as an extension.
    //
    // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
    // and is useful because there's otherwise no way to specify language
    // linkage within class scope.
    //
    // Check cautiously as the friend object kind isn't yet complete.
    if (New->getFriendObjectKind() != Decl::FOK_None) {
      Diag(New->getLocation(), diag::ext_retained_language_linkage) << New;
      Diag(OldLocation, PrevDiag);
    } else {
      Diag(New->getLocation(), diag::err_different_language_linkage) << New;
      Diag(OldLocation, PrevDiag);
      return true;
    }
  }

  // If the function types are compatible, merge the declarations. Ignore the
  // exception specifier because it was already checked above in
  // CheckEquivalentExceptionSpec, and we don't want follow-on diagnostics
  // about incompatible types under -fms-compatibility.
  if (Context.hasSameFunctionTypeIgnoringExceptionSpec(OldQTypeForComparison,
                                                       NewQType))
    return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);

  // If the types are imprecise (due to dependent constructs in friends or
  // local extern declarations), it's OK if they differ. We'll check again
  // during instantiation.
  if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType))
    return false;

  // Fall through for conflicting redeclarations and redefinitions.
}

// C: Function types need to be compatible, not identical. This handles
// duplicate function decls like "void f(int); void f(enum X);" properly.
if (!getLangOpts().CPlusPlus &&
    Context.typesAreCompatible(OldQType, NewQType)) {
  const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
  const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
  const FunctionProtoType *OldProto = nullptr;
  if (MergeTypeWithOld && isa<FunctionNoProtoType>(NewFuncType) &&
      (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
    // The old declaration provided a function prototype, but the
    // new declaration does not. Merge in the prototype.
    assert(!OldProto->hasExceptionSpec() && "Exception spec in C")((void)0);
    SmallVector<QualType, 16> ParamTypes(OldProto->param_types());
    NewQType =
        Context.getFunctionType(NewFuncType->getReturnType(), ParamTypes,
                                OldProto->getExtProtoInfo());
    New->setType(NewQType);
    New->setHasInheritedPrototype();

    // Synthesize parameters with the same types.
    SmallVector<ParmVarDecl*, 16> Params;
    for (const auto &ParamType : OldProto->param_types()) {
      ParmVarDecl *Param = ParmVarDecl::Create(Context, New, SourceLocation(),
                                               SourceLocation(), nullptr,
                                               ParamType, /*TInfo=*/nullptr,
                                               SC_None, nullptr);
      Param->setScopeInfo(0, Params.size());
      Param->setImplicit();
      Params.push_back(Param);
    }

    New->setParams(Params);
  }

  return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
}

// Check if the function types are compatible when pointer size address
// spaces are ignored.
if (Context.hasSameFunctionTypeIgnoringPtrSizes(OldQType, NewQType))
  return false;

// GNU C permits a K&R definition to follow a prototype declaration
// if the declared types of the parameters in the K&R definition
// match the types in the prototype declaration, even when the
// promoted types of the parameters from the K&R definition differ
// from the types in the prototype. GCC then keeps the types from
// the prototype.
//
// If a variadic prototype is followed by a non-variadic K&R definition,
// the K&R definition becomes variadic.  This is sort of an edge case, but
// it's legal per the standard depending on how you read C99 6.7.5.3p15 and
// C99 6.9.1p8.
if (!getLangOpts().CPlusPlus &&
    Old->hasPrototype() && !New->hasPrototype() &&
    New->getType()->getAs<FunctionProtoType>() &&
    Old->getNumParams() == New->getNumParams()) {
  SmallVector<QualType, 16> ArgTypes;
  SmallVector<GNUCompatibleParamWarning, 16> Warnings;
  const FunctionProtoType *OldProto
    = Old->getType()->getAs<FunctionProtoType>();
  const FunctionProtoType *NewProto
    = New->getType()->getAs<FunctionProtoType>();

  // Determine whether this is the GNU C extension.
  QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
                                             NewProto->getReturnType());
  bool LooseCompatible = !MergedReturn.isNull();
  for (unsigned Idx = 0, End = Old->getNumParams();
       LooseCompatible && Idx != End; ++Idx) {
    ParmVarDecl *OldParm = Old->getParamDecl(Idx);
    ParmVarDecl *NewParm = New->getParamDecl(Idx);
    if (Context.typesAreCompatible(OldParm->getType(),
                                   NewProto->getParamType(Idx))) {
      ArgTypes.push_back(NewParm->getType());
    } else if (Context.typesAreCompatible(OldParm->getType(),
                                          NewParm->getType(),
                                          /*CompareUnqualified=*/true)) {
      GNUCompatibleParamWarning Warn = { OldParm, NewParm,
                                         NewProto->getParamType(Idx) };
      Warnings.push_back(Warn);
      ArgTypes.push_back(NewParm->getType());
    } else
      LooseCompatible = false;
  }

  if (LooseCompatible) {
    for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
      Diag(Warnings[Warn].NewParm->getLocation(),
           diag::ext_param_promoted_not_compatible_with_prototype)
        << Warnings[Warn].PromotedType
        << Warnings[Warn].OldParm->getType();
      if (Warnings[Warn].OldParm->getLocation().isValid())
        Diag(Warnings[Warn].OldParm->getLocation(),
             diag::note_previous_declaration);
    }

    if (MergeTypeWithOld)
      New->setType(Context.getFunctionType(MergedReturn, ArgTypes,
                                           OldProto->getExtProtoInfo()));
    return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
  }

  // Fall through to diagnose conflicting types.
}

// A function that has already been declared has been redeclared or
// defined with a different type; show an appropriate diagnostic.

// If the previous declaration was an implicitly-generated builtin
// declaration, then at the very least we should use a specialized note.
unsigned BuiltinID;
if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
  // If it's actually a library-defined builtin function like 'malloc'
  // or 'printf', just warn about the incompatible redeclaration.
  if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
    Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
    Diag(OldLocation, diag::note_previous_builtin_declaration)
      << Old << Old->getType();
    return false;
  }

  PrevDiag = diag::note_previous_builtin_declaration;
}

Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
Diag(OldLocation, PrevDiag) << Old << Old->getType();
return true;
3878}

3880/// Completes the merge of two function declarations that are
3881/// known to be compatible.
3882///
3883/// This routine handles the merging of attributes and other
3884/// properties of function declarations from the old declaration to
3885/// the new declaration, once we know that New is in fact a
3886/// redeclaration of Old.
3887///
3888/// \returns false
3889bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
                                      Scope *S, bool MergeTypeWithOld) {
// Merge the attributes
mergeDeclAttributes(New, Old);

// Merge "pure" flag.
if (Old->isPure())
  New->setPure();

// Merge "used" flag.
if (Old->getMostRecentDecl()->isUsed(false))
  New->setIsUsed();

// Merge attributes from the parameters.  These can mismatch with K&R
// declarations.
if (New->getNumParams() == Old->getNumParams())
    for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
      ParmVarDecl *NewParam = New->getParamDecl(i);
      ParmVarDecl *OldParam = Old->getParamDecl(i);
      mergeParamDeclAttributes(NewParam, OldParam, *this);
      mergeParamDeclTypes(NewParam, OldParam, *this);
    }

if (getLangOpts().CPlusPlus)
  return MergeCXXFunctionDecl(New, Old, S);

// Merge the function types so the we get the composite types for the return
// and argument types. Per C11 6.2.7/4, only update the type if the old decl
// was visible.
QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
if (!Merged.isNull() && MergeTypeWithOld)
  New->setType(Merged);

return false;
3923}

3925void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
                              ObjCMethodDecl *oldMethod) {
// Merge the attributes, including deprecated/unavailable
AvailabilityMergeKind MergeKind =
    isa<ObjCProtocolDecl>(oldMethod->getDeclContext())
        ? (oldMethod->isOptional() ? AMK_OptionalProtocolImplementation
                                   : AMK_ProtocolImplementation)
        : isa<ObjCImplDecl>(newMethod->getDeclContext()) ? AMK_Redeclaration
                                                         : AMK_Override;

mergeDeclAttributes(newMethod, oldMethod, MergeKind);

// Merge attributes from the parameters.
ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
                                     oe = oldMethod->param_end();
for (ObjCMethodDecl::param_iterator
       ni = newMethod->param_begin(), ne = newMethod->param_end();
     ni != ne && oi != oe; ++ni, ++oi)
  mergeParamDeclAttributes(*ni, *oi, *this);

CheckObjCMethodOverride(newMethod, oldMethod);
3946}

3948static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
assert(!S.Context.hasSameType(New->getType(), Old->getType()))((void)0);

S.Diag(New->getLocation(), New->isThisDeclarationADefinition()
       ? diag::err_redefinition_different_type
       : diag::err_redeclaration_different_type)
  << New->getDeclName() << New->getType() << Old->getType();

diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation)
  = getNoteDiagForInvalidRedeclaration(Old, New);
S.Diag(OldLocation, PrevDiag);
New->setInvalidDecl();
3962}

3964/// MergeVarDeclTypes - We parsed a variable 'New' which has the same name and
3965/// scope as a previous declaration 'Old'.  Figure out how to merge their types,
3966/// emitting diagnostics as appropriate.
3967///
3968/// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back
3969/// to here in AddInitializerToDecl. We can't check them before the initializer
3970/// is attached.
3971void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
                           bool MergeTypeWithOld) {
if (New->isInvalidDecl() || Old->isInvalidDecl())
  return;

QualType MergedT;
if (getLangOpts().CPlusPlus) {
  if (New->getType()->isUndeducedType()) {
    // We don't know what the new type is until the initializer is attached.
    return;
  } else if (Context.hasSameType(New->getType(), Old->getType())) {
    // These could still be something that needs exception specs checked.
    return MergeVarDeclExceptionSpecs(New, Old);
  }
  // C++ [basic.link]p10:
  //   [...] the types specified by all declarations referring to a given
  //   object or function shall be identical, except that declarations for an
  //   array object can specify array types that differ by the presence or
  //   absence of a major array bound (8.3.4).
  else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
    const ArrayType *OldArray = Context.getAsArrayType(Old->getType());
    const ArrayType *NewArray = Context.getAsArrayType(New->getType());

    // We are merging a variable declaration New into Old. If it has an array
    // bound, and that bound differs from Old's bound, we should diagnose the
    // mismatch.
    if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
      for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
           PrevVD = PrevVD->getPreviousDecl()) {
        QualType PrevVDTy = PrevVD->getType();
        if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
          continue;

        if (!Context.hasSameType(New->getType(), PrevVDTy))
          return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
      }
    }

    if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
      if (Context.hasSameType(OldArray->getElementType(),
                              NewArray->getElementType()))
        MergedT = New->getType();
    }
    // FIXME: Check visibility. New is hidden but has a complete type. If New
    // has no array bound, it should not inherit one from Old, if Old is not
    // visible.
    else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
      if (Context.hasSameType(OldArray->getElementType(),
                              NewArray->getElementType()))
        MergedT = Old->getType();
    }
  }
  else if (New->getType()->isObjCObjectPointerType() &&
             Old->getType()->isObjCObjectPointerType()) {
    MergedT = Context.mergeObjCGCQualifiers(New->getType(),
                                            Old->getType());
  }
} else {
  // C 6.2.7p2:
  //   All declarations that refer to the same object or function shall have
  //   compatible type.
  MergedT = Context.mergeTypes(New->getType(), Old->getType());
}
if (MergedT.isNull()) {
  // It's OK if we couldn't merge types if either type is dependent, for a
  // block-scope variable. In other cases (static data members of class
  // templates, variable templates, ...), we require the types to be
  // equivalent.
  // FIXME: The C++ standard doesn't say anything about this.
  if ((New->getType()->isDependentType() ||
       Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
    // If the old type was dependent, we can't merge with it, so the new type
    // becomes dependent for now. We'll reproduce the original type when we
    // instantiate the TypeSourceInfo for the variable.
    if (!New->getType()->isDependentType() && MergeTypeWithOld)
      New->setType(Context.DependentTy);
    return;
  }
  return diagnoseVarDeclTypeMismatch(*this, New, Old);
}

// Don't actually update the type on the new declaration if the old
// declaration was an extern declaration in a different scope.
if (MergeTypeWithOld)
  New->setType(MergedT);
4056}

4058static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
                                LookupResult &Previous) {
// C11 6.2.7p4:
//   For an identifier with internal or external linkage declared
//   in a scope in which a prior declaration of that identifier is
//   visible, if the prior declaration specifies internal or
//   external linkage, the type of the identifier at the later
//   declaration becomes the composite type.
//
// If the variable isn't visible, we do not merge with its type.
if (Previous.isShadowed())
  return false;

if (S.getLangOpts().CPlusPlus) {
  // C++11 [dcl.array]p3:
  //   If there is a preceding declaration of the entity in the same
  //   scope in which the bound was specified, an omitted array bound
  //   is taken to be the same as in that earlier declaration.
  return NewVD->isPreviousDeclInSameBlockScope() ||
         (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
          !NewVD->getLexicalDeclContext()->isFunctionOrMethod());
} else {
  // If the old declaration was function-local, don't merge with its
  // type unless we're in the same function.
  return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
         OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
}
4085}

4087/// MergeVarDecl - We just parsed a variable 'New' which has the same name
4088/// and scope as a previous declaration 'Old'.  Figure out how to resolve this
4089/// situation, merging decls or emitting diagnostics as appropriate.
4090///
4091/// Tentative definition rules (C99 6.9.2p2) are checked by
4092/// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
4093/// definitions here, since the initializer hasn't been attached.
4094///
4095void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
// If the new decl is already invalid, don't do any other checking.
if (New->isInvalidDecl())
  return;

if (!shouldLinkPossiblyHiddenDecl(Previous, New))
  return;

VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();

// Verify the old decl was also a variable or variable template.
VarDecl *Old = nullptr;
VarTemplateDecl *OldTemplate = nullptr;
if (Previous.isSingleResult()) {
  if (NewTemplate) {
    OldTemplate = dyn_cast<VarTemplateDecl>(Previous.getFoundDecl());
    Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;

    if (auto *Shadow =
            dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
      if (checkUsingShadowRedecl<VarTemplateDecl>(*this, Shadow, NewTemplate))
        return New->setInvalidDecl();
  } else {
    Old = dyn_cast<VarDecl>(Previous.getFoundDecl());

    if (auto *Shadow =
            dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
      if (checkUsingShadowRedecl<VarDecl>(*this, Shadow, New))
        return New->setInvalidDecl();
  }
}
if (!Old) {
  Diag(New->getLocation(), diag::err_redefinition_different_kind)
      << New->getDeclName();
  notePreviousDefinition(Previous.getRepresentativeDecl(),
                         New->getLocation());
  return New->setInvalidDecl();
}

// If the old declaration was found in an inline namespace and the new
// declaration was qualified, update the DeclContext to match.
adjustDeclContextForDeclaratorDecl(New, Old);

// Ensure the template parameters are compatible.
if (NewTemplate &&
    !TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
                                    OldTemplate->getTemplateParameters(),
                                    /*Complain=*/true, TPL_TemplateMatch))
  return New->setInvalidDecl();

// C++ [class.mem]p1:
//   A member shall not be declared twice in the member-specification [...]
//
// Here, we need only consider static data members.
if (Old->isStaticDataMember() && !New->isOutOfLine()) {
  Diag(New->getLocation(), diag::err_duplicate_member)
    << New->getIdentifier();
  Diag(Old->getLocation(), diag::note_previous_declaration);
  New->setInvalidDecl();
}

mergeDeclAttributes(New, Old);
// Warn if an already-declared variable is made a weak_import in a subsequent
// declaration
if (New->hasAttr<WeakImportAttr>() &&
    Old->getStorageClass() == SC_None &&
    !Old->hasAttr<WeakImportAttr>()) {
  Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
  notePreviousDefinition(Old, New->getLocation());
  // Remove weak_import attribute on new declaration.
  New->dropAttr<WeakImportAttr>();
}

if (New->hasAttr<InternalLinkageAttr>() &&
    !Old->hasAttr<InternalLinkageAttr>()) {
  Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
      << New->getDeclName();
  notePreviousDefinition(Old, New->getLocation());
  New->dropAttr<InternalLinkageAttr>();
}

// Merge the types.
VarDecl *MostRecent = Old->getMostRecentDecl();
if (MostRecent != Old) {
  MergeVarDeclTypes(New, MostRecent,
                    mergeTypeWithPrevious(*this, New, MostRecent, Previous));
  if (New->isInvalidDecl())
    return;
}

MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous));
if (New->isInvalidDecl())
  return;

diag::kind PrevDiag;
SourceLocation OldLocation;
std::tie(PrevDiag, OldLocation) =
    getNoteDiagForInvalidRedeclaration(Old, New);

// [dcl.stc]p8: Check if we have a non-static decl followed by a static.
if (New->getStorageClass() == SC_Static &&
    !New->isStaticDataMember() &&
    Old->hasExternalFormalLinkage()) {
  if (getLangOpts().MicrosoftExt) {
    Diag(New->getLocation(), diag::ext_static_non_static)
        << New->getDeclName();
    Diag(OldLocation, PrevDiag);
  } else {
    Diag(New->getLocation(), diag::err_static_non_static)
        << New->getDeclName();
    Diag(OldLocation, PrevDiag);
    return New->setInvalidDecl();
  }
}
// C99 6.2.2p4:
//   For an identifier declared with the storage-class specifier
//   extern in a scope in which a prior declaration of that
//   identifier is visible,23) if the prior declaration specifies
//   internal or external linkage, the linkage of the identifier at
//   the later declaration is the same as the linkage specified at
//   the prior declaration. If no prior declaration is visible, or
//   if the prior declaration specifies no linkage, then the
//   identifier has external linkage.
if (New->hasExternalStorage() && Old->hasLinkage())
  /* Okay */;
else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
         !New->isStaticDataMember() &&
         Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
  Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
  Diag(OldLocation, PrevDiag);
  return New->setInvalidDecl();
}

// Check if extern is followed by non-extern and vice-versa.
if (New->hasExternalStorage() &&
    !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
  Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName();
  Diag(OldLocation, PrevDiag);
  return New->setInvalidDecl();
}
if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
    !New->hasExternalStorage()) {
  Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName();
  Diag(OldLocation, PrevDiag);
  return New->setInvalidDecl();
}

if (CheckRedeclarationModuleOwnership(New, Old))
  return;

// Variables with external linkage are analyzed in FinalizeDeclaratorGroup.

// FIXME: The test for external storage here seems wrong? We still
// need to check for mismatches.
if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
    // Don't complain about out-of-line definitions of static members.
    !(Old->getLexicalDeclContext()->isRecord() &&
      !New->getLexicalDeclContext()->isRecord())) {
  Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
  Diag(OldLocation, PrevDiag);
  return New->setInvalidDecl();
}

if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
  if (VarDecl *Def = Old->getDefinition()) {
    // C++1z [dcl.fcn.spec]p4:
    //   If the definition of a variable appears in a translation unit before
    //   its first declaration as inline, the program is ill-formed.
    Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
    Diag(Def->getLocation(), diag::note_previous_definition);
  }
}

// If this redeclaration makes the variable inline, we may need to add it to
// UndefinedButUsed.
if (!Old->isInline() && New->isInline() && Old->isUsed(false) &&
    !Old->getDefinition() && !New->isThisDeclarationADefinition())
  UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
                                         SourceLocation()));

if (New->getTLSKind() != Old->getTLSKind()) {
  if (!Old->getTLSKind()) {
    Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
    Diag(OldLocation, PrevDiag);
  } else if (!New->getTLSKind()) {
    Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
    Diag(OldLocation, PrevDiag);
  } else {
    // Do not allow redeclaration to change the variable between requiring
    // static and dynamic initialization.
    // FIXME: GCC allows this, but uses the TLS keyword on the first
    // declaration to determine the kind. Do we need to be compatible here?
    Diag(New->getLocation(), diag::err_thread_thread_different_kind)
      << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
    Diag(OldLocation, PrevDiag);
  }
}

// C++ doesn't have tentative definitions, so go right ahead and check here.
if (getLangOpts().CPlusPlus &&
    New->isThisDeclarationADefinition() == VarDecl::Definition) {
  if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
      Old->getCanonicalDecl()->isConstexpr()) {
    // This definition won't be a definition any more once it's been merged.
    Diag(New->getLocation(),
         diag::warn_deprecated_redundant_constexpr_static_def);
  } else if (VarDecl *Def = Old->getDefinition()) {
    if (checkVarDeclRedefinition(Def, New))
      return;
  }
}

if (haveIncompatibleLanguageLinkages(Old, New)) {
  Diag(New->getLocation(), diag::err_different_language_linkage) << New;
  Diag(OldLocation, PrevDiag);
  New->setInvalidDecl();
  return;
}

// Merge "used" flag.
if (Old->getMostRecentDecl()->isUsed(false))
  New->setIsUsed();

// Keep a chain of previous declarations.
New->setPreviousDecl(Old);
if (NewTemplate)
  NewTemplate->setPreviousDecl(OldTemplate);

// Inherit access appropriately.
New->setAccess(Old->getAccess());
if (NewTemplate)
  NewTemplate->setAccess(New->getAccess());

if (Old->isInline())
  New->setImplicitlyInline();
4330}

4332void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
SourceManager &SrcMgr = getSourceManager();
auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first);
auto &HSI = PP.getHeaderSearchInfo();
StringRef HdrFilename =
    SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));

auto noteFromModuleOrInclude = [&](Module *Mod,
                                   SourceLocation IncLoc) -> bool {
  // Redefinition errors with modules are common with non modular mapped
  // headers, example: a non-modular header H in module A that also gets
  // included directly in a TU. Pointing twice to the same header/definition
  // is confusing, try to get better diagnostics when modules is on.
  if (IncLoc.isValid()) {
    if (Mod) {
      Diag(IncLoc, diag::note_redefinition_modules_same_file)
          << HdrFilename.str() << Mod->getFullModuleName();
      if (!Mod->DefinitionLoc.isInvalid())
        Diag(Mod->DefinitionLoc, diag::note_defined_here)
            << Mod->getFullModuleName();
    } else {
      Diag(IncLoc, diag::note_redefinition_include_same_file)
          << HdrFilename.str();
    }
    return true;
  }

  return false;
};

// Is it the same file and same offset? Provide more information on why
// this leads to a redefinition error.
if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
  SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
  SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
  bool EmittedDiag =
      noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
  EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);

  // If the header has no guards, emit a note suggesting one.
  if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld))
    Diag(Old->getLocation(), diag::note_use_ifdef_guards);

  if (EmittedDiag)
    return;
}

// Redefinition coming from different files or couldn't do better above.
if (Old->getLocation().isValid())
  Diag(Old->getLocation(), diag::note_previous_definition);
4385}

4387/// We've just determined that \p Old and \p New both appear to be definitions
4388/// of the same variable. Either diagnose or fix the problem.
4389bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
if (!hasVisibleDefinition(Old) &&
    (New->getFormalLinkage() == InternalLinkage ||
     New->isInline() ||
     New->getDescribedVarTemplate() ||
     New->getNumTemplateParameterLists() ||
     New->getDeclContext()->isDependentContext())) {
  // The previous definition is hidden, and multiple definitions are
  // permitted (in separate TUs). Demote this to a declaration.
  New->demoteThisDefinitionToDeclaration();

  // Make the canonical definition visible.
  if (auto *OldTD = Old->getDescribedVarTemplate())
    makeMergedDefinitionVisible(OldTD);
  makeMergedDefinitionVisible(Old);
  return false;
} else {
  Diag(New->getLocation(), diag::err_redefinition) << New;
  notePreviousDefinition(Old, New->getLocation());
  New->setInvalidDecl();
  return true;
}
4411}

4413/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4414/// no declarator (e.g. "struct foo;") is parsed.
4415Decl *
4416Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                               RecordDecl *&AnonRecord) {
return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg(), false,
                                  AnonRecord);
4420}

4422// The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
4423// disambiguate entities defined in different scopes.
4424// While the VS2015 ABI fixes potential miscompiles, it is also breaks
4425// compatibility.
4426// We will pick our mangling number depending on which version of MSVC is being
4427// targeted.
4428static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
return LO.isCompatibleWithMSVC(LangOptions::MSVC2015)
           ? S->getMSCurManglingNumber()
           : S->getMSLastManglingNumber();
4432}

4434void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
if (!Context.getLangOpts().CPlusPlus)
  return;

if (isa<CXXRecordDecl>(Tag->getParent())) {
  // If this tag is the direct child of a class, number it if
  // it is anonymous.
  if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
    return;
  MangleNumberingContext &MCtx =
      Context.getManglingNumberContext(Tag->getParent());
  Context.setManglingNumber(
      Tag, MCtx.getManglingNumber(
               Tag, getMSManglingNumber(getLangOpts(), TagScope)));
  return;
}

// If this tag isn't a direct child of a class, number it if it is local.
MangleNumberingContext *MCtx;
Decl *ManglingContextDecl;
std::tie(MCtx, ManglingContextDecl) =
    getCurrentMangleNumberContext(Tag->getDeclContext());
if (MCtx) {
  Context.setManglingNumber(
      Tag, MCtx->getManglingNumber(
               Tag, getMSManglingNumber(getLangOpts(), TagScope)));
}
4461}

4463namespace {
4464struct NonCLikeKind {
enum {
  None,
  BaseClass,
  DefaultMemberInit,
  Lambda,
  Friend,
  OtherMember,
  Invalid,
} Kind = None;
SourceRange Range;

explicit operator bool() { return Kind != None; }
4477};
4478}

4480/// Determine whether a class is C-like, according to the rules of C++
4481/// [dcl.typedef] for anonymous classes with typedef names for linkage.
4482static NonCLikeKind getNonCLikeKindForAnonymousStruct(const CXXRecordDecl *RD) {
if (RD->isInvalidDecl())
  return {NonCLikeKind::Invalid, {}};

// C++ [dcl.typedef]p9: [P1766R1]
//   An unnamed class with a typedef name for linkage purposes shall not
//
//    -- have any base classes
if (RD->getNumBases())
  return {NonCLikeKind::BaseClass,
          SourceRange(RD->bases_begin()->getBeginLoc(),
                      RD->bases_end()[-1].getEndLoc())};
bool Invalid = false;
for (Decl *D : RD->decls()) {
  // Don't complain about things we already diagnosed.
  if (D->isInvalidDecl()) {
    Invalid = true;
    continue;
  }

  //  -- have any [...] default member initializers
  if (auto *FD = dyn_cast<FieldDecl>(D)) {
    if (FD->hasInClassInitializer()) {
      auto *Init = FD->getInClassInitializer();
      return {NonCLikeKind::DefaultMemberInit,
              Init ? Init->getSourceRange() : D->getSourceRange()};
    }
    continue;
  }

  // FIXME: We don't allow friend declarations. This violates the wording of
  // P1766, but not the intent.
  if (isa<FriendDecl>(D))
    return {NonCLikeKind::Friend, D->getSourceRange()};

  //  -- declare any members other than non-static data members, member
  //     enumerations, or member classes,
  if (isa<StaticAssertDecl>(D) || isa<IndirectFieldDecl>(D) ||
      isa<EnumDecl>(D))
    continue;
  auto *MemberRD = dyn_cast<CXXRecordDecl>(D);
  if (!MemberRD) {
    if (D->isImplicit())
      continue;
    return {NonCLikeKind::OtherMember, D->getSourceRange()};
  }

  //  -- contain a lambda-expression,
  if (MemberRD->isLambda())
    return {NonCLikeKind::Lambda, MemberRD->getSourceRange()};

  //  and all member classes shall also satisfy these requirements
  //  (recursively).
  if (MemberRD->isThisDeclarationADefinition()) {
    if (auto Kind = getNonCLikeKindForAnonymousStruct(MemberRD))
      return Kind;
  }
}

return {Invalid ? NonCLikeKind::Invalid : NonCLikeKind::None, {}};
4542}

4544void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
                                      TypedefNameDecl *NewTD) {
if (TagFromDeclSpec->isInvalidDecl())
  return;

// Do nothing if the tag already has a name for linkage purposes.
if (TagFromDeclSpec->hasNameForLinkage())
  return;

// A well-formed anonymous tag must always be a TUK_Definition.
assert(TagFromDeclSpec->isThisDeclarationADefinition())((void)0);

// The type must match the tag exactly;  no qualifiers allowed.
if (!Context.hasSameType(NewTD->getUnderlyingType(),
                         Context.getTagDeclType(TagFromDeclSpec))) {
  if (getLangOpts().CPlusPlus)
    Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD);
  return;
}

// C++ [dcl.typedef]p9: [P1766R1, applied as DR]
//   An unnamed class with a typedef name for linkage purposes shall [be
//   C-like].
//
// FIXME: Also diagnose if we've already computed the linkage. That ideally
// shouldn't happen, but there are constructs that the language rule doesn't
// disallow for which we can't reasonably avoid computing linkage early.
const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TagFromDeclSpec);
NonCLikeKind NonCLike = RD ? getNonCLikeKindForAnonymousStruct(RD)
                           : NonCLikeKind();
bool ChangesLinkage = TagFromDeclSpec->hasLinkageBeenComputed();
if (NonCLike || ChangesLinkage) {
  if (NonCLike.Kind == NonCLikeKind::Invalid)
    return;

  unsigned DiagID = diag::ext_non_c_like_anon_struct_in_typedef;
  if (ChangesLinkage) {
    // If the linkage changes, we can't accept this as an extension.
    if (NonCLike.Kind == NonCLikeKind::None)
      DiagID = diag::err_typedef_changes_linkage;
    else
      DiagID = diag::err_non_c_like_anon_struct_in_typedef;
  }

  SourceLocation FixitLoc =
      getLocForEndOfToken(TagFromDeclSpec->getInnerLocStart());
  llvm::SmallString<40> TextToInsert;
  TextToInsert += ' ';
  TextToInsert += NewTD->getIdentifier()->getName();

  Diag(FixitLoc, DiagID)
    << isa<TypeAliasDecl>(NewTD)
    << FixItHint::CreateInsertion(FixitLoc, TextToInsert);
  if (NonCLike.Kind != NonCLikeKind::None) {
    Diag(NonCLike.Range.getBegin(), diag::note_non_c_like_anon_struct)
      << NonCLike.Kind - 1 << NonCLike.Range;
  }
  Diag(NewTD->getLocation(), diag::note_typedef_for_linkage_here)
    << NewTD << isa<TypeAliasDecl>(NewTD);

  if (ChangesLinkage)
    return;
}

// Otherwise, set this as the anon-decl typedef for the tag.
TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
4610}

4612static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) {
switch (T) {
case DeclSpec::TST_class:
  return 0;
case DeclSpec::TST_struct:
  return 1;
case DeclSpec::TST_interface:
  return 2;
case DeclSpec::TST_union:
  return 3;
case DeclSpec::TST_enum:
  return 4;
default:
  llvm_unreachable("unexpected type specifier")__builtin_unreachable();
}
4627}

4629/// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4630/// no declarator (e.g. "struct foo;") is parsed. It also accepts template
4631/// parameters to cope with template friend declarations.
4632Decl *
4633Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
                               MultiTemplateParamsArg TemplateParams,
                               bool IsExplicitInstantiation,
                               RecordDecl *&AnonRecord) {
Decl *TagD = nullptr;
TagDecl *Tag = nullptr;
if (DS.getTypeSpecType() == DeclSpec::TST_class ||
    DS.getTypeSpecType() == DeclSpec::TST_struct ||
    DS.getTypeSpecType() == DeclSpec::TST_interface ||
    DS.getTypeSpecType() == DeclSpec::TST_union ||
    DS.getTypeSpecType() == DeclSpec::TST_enum) {
  TagD = DS.getRepAsDecl();

  if (!TagD) // We probably had an error
    return nullptr;

  // Note that the above type specs guarantee that the
  // type rep is a Decl, whereas in many of the others
  // it's a Type.
  if (isa<TagDecl>(TagD))
    Tag = cast<TagDecl>(TagD);
  else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(TagD))
    Tag = CTD->getTemplatedDecl();
}

if (Tag) {
  handleTagNumbering(Tag, S);
  Tag->setFreeStanding();
  if (Tag->isInvalidDecl())
    return Tag;
}

if (unsigned TypeQuals = DS.getTypeQualifiers()) {
  // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
  // or incomplete types shall not be restrict-qualified."
  if (TypeQuals & DeclSpec::TQ_restrict)
    Diag(DS.getRestrictSpecLoc(),
         diag::err_typecheck_invalid_restrict_not_pointer_noarg)
         << DS.getSourceRange();
}

if (DS.isInlineSpecified())
  Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
      << getLangOpts().CPlusPlus17;

if (DS.hasConstexprSpecifier()) {
  // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
  // and definitions of functions and variables.
  // C++2a [dcl.constexpr]p1: The consteval specifier shall be applied only to
  // the declaration of a function or function template
  if (Tag)
    Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
        << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType())
        << static_cast<int>(DS.getConstexprSpecifier());
  else
    Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_wrong_decl_kind)
        << static_cast<int>(DS.getConstexprSpecifier());
  // Don't emit warnings after this error.
  return TagD;
}

DiagnoseFunctionSpecifiers(DS);

if (DS.isFriendSpecified()) {
  // If we're dealing with a decl but not a TagDecl, assume that
  // whatever routines created it handled the friendship aspect.
  if (TagD && !Tag)
    return nullptr;
  return ActOnFriendTypeDecl(S, DS, TemplateParams);
}

const CXXScopeSpec &SS = DS.getTypeSpecScope();
bool IsExplicitSpecialization =
  !TemplateParams.empty() && TemplateParams.back()->size() == 0;
if (Tag && SS.isNotEmpty() && !Tag->isCompleteDefinition() &&
    !IsExplicitInstantiation && !IsExplicitSpecialization &&
    !isa<ClassTemplatePartialSpecializationDecl>(Tag)) {
  // Per C++ [dcl.type.elab]p1, a class declaration cannot have a
  // nested-name-specifier unless it is an explicit instantiation
  // or an explicit specialization.
  //
  // FIXME: We allow class template partial specializations here too, per the
  // obvious intent of DR1819.
  //
  // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either.
  Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
      << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange();
  return nullptr;
}

// Track whether this decl-specifier declares anything.
bool DeclaresAnything = true;

// Handle anonymous struct definitions.
if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
  if (!Record->getDeclName() && Record->isCompleteDefinition() &&
      DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
    if (getLangOpts().CPlusPlus ||
        Record->getDeclContext()->isRecord()) {
      // If CurContext is a DeclContext that can contain statements,
      // RecursiveASTVisitor won't visit the decls that
      // BuildAnonymousStructOrUnion() will put into CurContext.
      // Also store them here so that they can be part of the
      // DeclStmt that gets created in this case.
      // FIXME: Also return the IndirectFieldDecls created by
      // BuildAnonymousStructOr union, for the same reason?
      if (CurContext->isFunctionOrMethod())
        AnonRecord = Record;
      return BuildAnonymousStructOrUnion(S, DS, AS, Record,
                                         Context.getPrintingPolicy());
    }

    DeclaresAnything = false;
  }
}

// C11 6.7.2.1p2:
//   A struct-declaration that does not declare an anonymous structure or
//   anonymous union shall contain a struct-declarator-list.
//
// This rule also existed in C89 and C99; the grammar for struct-declaration
// did not permit a struct-declaration without a struct-declarator-list.
if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
    DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
  // Check for Microsoft C extension: anonymous struct/union member.
  // Handle 2 kinds of anonymous struct/union:
  //   struct STRUCT;
  //   union UNION;
  // and
  //   STRUCT_TYPE;  <- where STRUCT_TYPE is a typedef struct.
  //   UNION_TYPE;   <- where UNION_TYPE is a typedef union.
  if ((Tag && Tag->getDeclName()) ||
      DS.getTypeSpecType() == DeclSpec::TST_typename) {
    RecordDecl *Record = nullptr;
    if (Tag)
      Record = dyn_cast<RecordDecl>(Tag);
    else if (const RecordType *RT =
                 DS.getRepAsType().get()->getAsStructureType())
      Record = RT->getDecl();
    else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType())
      Record = UT->getDecl();

    if (Record && getLangOpts().MicrosoftExt) {
      Diag(DS.getBeginLoc(), diag::ext_ms_anonymous_record)
          << Record->isUnion() << DS.getSourceRange();
      return BuildMicrosoftCAnonymousStruct(S, DS, Record);
    }

    DeclaresAnything = false;
  }
}

// Skip all the checks below if we have a type error.
if (DS.getTypeSpecType() == DeclSpec::TST_error ||
    (TagD && TagD->isInvalidDecl()))
  return TagD;

if (getLangOpts().CPlusPlus &&
    DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
  if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
    if (Enum->enumerator_begin() == Enum->enumerator_end() &&
        !Enum->getIdentifier() && !Enum->isInvalidDecl())
      DeclaresAnything = false;

if (!DS.isMissingDeclaratorOk()) {
  // Customize diagnostic for a typedef missing a name.
  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
    Diag(DS.getBeginLoc(), diag::ext_typedef_without_a_name)
        << DS.getSourceRange();
  else
    DeclaresAnything = false;
}

if (DS.isModulePrivateSpecified() &&
    Tag && Tag->getDeclContext()->isFunctionOrMethod())
  Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class)
    << Tag->getTagKind()
    << FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc());

ActOnDocumentableDecl(TagD);

// C 6.7/2:
//   A declaration [...] shall declare at least a declarator [...], a tag,
//   or the members of an enumeration.
// C++ [dcl.dcl]p3:
//   [If there are no declarators], and except for the declaration of an
//   unnamed bit-field, the decl-specifier-seq shall introduce one or more
//   names into the program, or shall redeclare a name introduced by a
//   previous declaration.
if (!DeclaresAnything) {
  // In C, we allow this as a (popular) extension / bug. Don't bother
  // producing further diagnostics for redundant qualifiers after this.
  Diag(DS.getBeginLoc(), (IsExplicitInstantiation || !TemplateParams.empty())
                             ? diag::err_no_declarators
                             : diag::ext_no_declarators)
      << DS.getSourceRange();
  return TagD;
}

// C++ [dcl.stc]p1:
//   If a storage-class-specifier appears in a decl-specifier-seq, [...] the
//   init-declarator-list of the declaration shall not be empty.
// C++ [dcl.fct.spec]p1:
//   If a cv-qualifier appears in a decl-specifier-seq, the
//   init-declarator-list of the declaration shall not be empty.
//
// Spurious qualifiers here appear to be valid in C.
unsigned DiagID = diag::warn_standalone_specifier;
if (getLangOpts().CPlusPlus)
  DiagID = diag::ext_standalone_specifier;

// Note that a linkage-specification sets a storage class, but
// 'extern "C" struct foo;' is actually valid and not theoretically
// useless.
if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
  if (SCS == DeclSpec::SCS_mutable)
    // Since mutable is not a viable storage class specifier in C, there is
    // no reason to treat it as an extension. Instead, diagnose as an error.
    Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember);
  else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
    Diag(DS.getStorageClassSpecLoc(), DiagID)
      << DeclSpec::getSpecifierName(SCS);
}

if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
  Diag(DS.getThreadStorageClassSpecLoc(), DiagID)
    << DeclSpec::getSpecifierName(TSCS);
if (DS.getTypeQualifiers()) {
  if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
    Diag(DS.getConstSpecLoc(), DiagID) << "const";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
    Diag(DS.getConstSpecLoc(), DiagID) << "volatile";
  // Restrict is covered above.
  if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
    Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
  if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
    Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
}

// Warn about ignored type attributes, for example:
// __attribute__((aligned)) struct A;
// Attributes should be placed after tag to apply to type declaration.
if (!DS.getAttributes().empty()) {
  DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
  if (TypeSpecType == DeclSpec::TST_class ||
      TypeSpecType == DeclSpec::TST_struct ||
      TypeSpecType == DeclSpec::TST_interface ||
      TypeSpecType == DeclSpec::TST_union ||
      TypeSpecType == DeclSpec::TST_enum) {
    for (const ParsedAttr &AL : DS.getAttributes())
      Diag(AL.getLoc(), diag::warn_declspec_attribute_ignored)
          << AL << GetDiagnosticTypeSpecifierID(TypeSpecType);
  }
}

return TagD;
4889}

4891/// We are trying to inject an anonymous member into the given scope;
4892/// check if there's an existing declaration that can't be overloaded.
4893///
4894/// \return true if this is a forbidden redeclaration
4895static bool CheckAnonMemberRedeclaration(Sema &SemaRef,
                                       Scope *S,
                                       DeclContext *Owner,
                                       DeclarationName Name,
                                       SourceLocation NameLoc,
                                       bool IsUnion) {
LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName,
               Sema::ForVisibleRedeclaration);
if (!SemaRef.LookupName(R, S)) return false;

// Pick a representative declaration.
NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
assert(PrevDecl && "Expected a non-null Decl")((void)0);

if (!SemaRef.isDeclInScope(PrevDecl, Owner, S))
  return false;

SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl)
  << IsUnion << Name;
SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration);

return true;
4917}

4919/// InjectAnonymousStructOrUnionMembers - Inject the members of the
4920/// anonymous struct or union AnonRecord into the owning context Owner
4921/// and scope S. This routine will be invoked just after we realize
4922/// that an unnamed union or struct is actually an anonymous union or
4923/// struct, e.g.,
4924///
4925/// @code
4926/// union {
4927///   int i;
4928///   float f;
4929/// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
4930///    // f into the surrounding scope.x
4931/// @endcode
4932///
4933/// This routine is recursive, injecting the names of nested anonymous
4934/// structs/unions into the owning context and scope as well.
4935static bool
4936InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
                                  RecordDecl *AnonRecord, AccessSpecifier AS,
                                  SmallVectorImpl<NamedDecl *> &Chaining) {
bool Invalid = false;

// Look every FieldDecl and IndirectFieldDecl with a name.
for (auto *D : AnonRecord->decls()) {
  if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
      cast<NamedDecl>(D)->getDeclName()) {
    ValueDecl *VD = cast<ValueDecl>(D);
    if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(),
                                     VD->getLocation(),
                                     AnonRecord->isUnion())) {
      // C++ [class.union]p2:
      //   The names of the members of an anonymous union shall be
      //   distinct from the names of any other entity in the
      //   scope in which the anonymous union is declared.
      Invalid = true;
    } else {
      // C++ [class.union]p2:
      //   For the purpose of name lookup, after the anonymous union
      //   definition, the members of the anonymous union are
      //   considered to have been defined in the scope in which the
      //   anonymous union is declared.
      unsigned OldChainingSize = Chaining.size();
      if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
        Chaining.append(IF->chain_begin(), IF->chain_end());
      else
        Chaining.push_back(VD);

      assert(Chaining.size() >= 2)((void)0);
      NamedDecl **NamedChain =
        new (SemaRef.Context)NamedDecl*[Chaining.size()];
      for (unsigned i = 0; i < Chaining.size(); i++)
        NamedChain[i] = Chaining[i];

      IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
          SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
          VD->getType(), {NamedChain, Chaining.size()});

      for (const auto *Attr : VD->attrs())
        IndirectField->addAttr(Attr->clone(SemaRef.Context));

      IndirectField->setAccess(AS);
      IndirectField->setImplicit();
      SemaRef.PushOnScopeChains(IndirectField, S);

      // That includes picking up the appropriate access specifier.
      if (AS != AS_none) IndirectField->setAccess(AS);

      Chaining.resize(OldChainingSize);
    }
  }
}

return Invalid;
4992}

4994/// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
4995/// a VarDecl::StorageClass. Any error reporting is up to the caller:
4996/// illegal input values are mapped to SC_None.
4997static StorageClass
4998StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
assert(StorageClassSpec != DeclSpec::SCS_typedef &&((void)0)
       "Parser allowed 'typedef' as storage class VarDecl.")((void)0);
switch (StorageClassSpec) {
case DeclSpec::SCS_unspecified:    return SC_None;
case DeclSpec::SCS_extern:
  if (DS.isExternInLinkageSpec())
    return SC_None;
  return SC_Extern;
case DeclSpec::SCS_static:         return SC_Static;
case DeclSpec::SCS_auto:           return SC_Auto;
case DeclSpec::SCS_register:       return SC_Register;
case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
  // Illegal SCSs map to None: error reporting is up to the caller.
case DeclSpec::SCS_mutable:        // Fall through.
case DeclSpec::SCS_typedef:        return SC_None;
}
llvm_unreachable("unknown storage class specifier")__builtin_unreachable();
5017}

5019static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
assert(Record->hasInClassInitializer())((void)0);

for (const auto *I : Record->decls()) {
  const auto *FD = dyn_cast<FieldDecl>(I);
  if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
    FD = IFD->getAnonField();
  if (FD && FD->hasInClassInitializer())
    return FD->getLocation();
}

llvm_unreachable("couldn't find in-class initializer")__builtin_unreachable();
5031}

5033static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
                                    SourceLocation DefaultInitLoc) {
if (!Parent->isUnion() || !Parent->hasInClassInitializer())
  return;

S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization);
S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0;
5040}

5042static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
                                    CXXRecordDecl *AnonUnion) {
if (!Parent->isUnion() || !Parent->hasInClassInitializer())
  return;

checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion));
5048}

5050/// BuildAnonymousStructOrUnion - Handle the declaration of an
5051/// anonymous structure or union. Anonymous unions are a C++ feature
5052/// (C++ [class.union]) and a C11 feature; anonymous structures
5053/// are a C11 feature and GNU C++ extension.
5054Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
                                      AccessSpecifier AS,
                                      RecordDecl *Record,
                                      const PrintingPolicy &Policy) {
DeclContext *Owner = Record->getDeclContext();

// Diagnose whether this anonymous struct/union is an extension.
if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
  Diag(Record->getLocation(), diag::ext_anonymous_union);
else if (!Record->isUnion() && getLangOpts().CPlusPlus)
  Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
else if (!Record->isUnion() && !getLangOpts().C11)
  Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);

// C and C++ require different kinds of checks for anonymous
// structs/unions.
bool Invalid = false;
if (getLangOpts().CPlusPlus) {
  const char *PrevSpec = nullptr;
  if (Record->isUnion()) {
    // C++ [class.union]p6:
    // C++17 [class.union.anon]p2:
    //   Anonymous unions declared in a named namespace or in the
    //   global namespace shall be declared static.
    unsigned DiagID;
    DeclContext *OwnerScope = Owner->getRedeclContext();
    if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
        (OwnerScope->isTranslationUnit() ||
         (OwnerScope->isNamespace() &&
          !cast<NamespaceDecl>(OwnerScope)->isAnonymousNamespace()))) {
      Diag(Record->getLocation(), diag::err_anonymous_union_not_static)
        << FixItHint::CreateInsertion(Record->getLocation(), "static ");

      // Recover by adding 'static'.
      DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(),
                             PrevSpec, DiagID, Policy);
    }
    // C++ [class.union]p6:
    //   A storage class is not allowed in a declaration of an
    //   anonymous union in a class scope.
    else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
             isa<RecordDecl>(Owner)) {
      Diag(DS.getStorageClassSpecLoc(),
           diag::err_anonymous_union_with_storage_spec)
        << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());

      // Recover by removing the storage specifier.
      DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified,
                             SourceLocation(),
                             PrevSpec, DiagID, Context.getPrintingPolicy());
    }
  }

  // Ignore const/volatile/restrict qualifiers.
  if (DS.getTypeQualifiers()) {
    if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
      Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified)
        << Record->isUnion() << "const"
        << FixItHint::CreateRemoval(DS.getConstSpecLoc());
    if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
      Diag(DS.getVolatileSpecLoc(),
           diag::ext_anonymous_struct_union_qualified)
        << Record->isUnion() << "volatile"
        << FixItHint::CreateRemoval(DS.getVolatileSpecLoc());
    if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
      Diag(DS.getRestrictSpecLoc(),
           diag::ext_anonymous_struct_union_qualified)
        << Record->isUnion() << "restrict"
        << FixItHint::CreateRemoval(DS.getRestrictSpecLoc());
    if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
      Diag(DS.getAtomicSpecLoc(),
           diag::ext_anonymous_struct_union_qualified)
        << Record->isUnion() << "_Atomic"
        << FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
    if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
      Diag(DS.getUnalignedSpecLoc(),
           diag::ext_anonymous_struct_union_qualified)
        << Record->isUnion() << "__unaligned"
        << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());

    DS.ClearTypeQualifiers();
  }

  // C++ [class.union]p2:
  //   The member-specification of an anonymous union shall only
  //   define non-static data members. [Note: nested types and
  //   functions cannot be declared within an anonymous union. ]
  for (auto *Mem : Record->decls()) {
    // Ignore invalid declarations; we already diagnosed them.
    if (Mem->isInvalidDecl())
      continue;

    if (auto *FD = dyn_cast<FieldDecl>(Mem)) {
      // C++ [class.union]p3:
      //   An anonymous union shall not have private or protected
      //   members (clause 11).
      assert(FD->getAccess() != AS_none)((void)0);
      if (FD->getAccess() != AS_public) {
        Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
          << Record->isUnion() << (FD->getAccess() == AS_protected);
        Invalid = true;
      }

      // C++ [class.union]p1
      //   An object of a class with a non-trivial constructor, a non-trivial
      //   copy constructor, a non-trivial destructor, or a non-trivial copy
      //   assignment operator cannot be a member of a union, nor can an
      //   array of such objects.
      if (CheckNontrivialField(FD))
        Invalid = true;
    } else if (Mem->isImplicit()) {
      // Any implicit members are fine.
    } else if (isa<TagDecl>(Mem) && Mem->getDeclContext() != Record) {
      // This is a type that showed up in an
      // elaborated-type-specifier inside the anonymous struct or
      // union, but which actually declares a type outside of the
      // anonymous struct or union. It's okay.
    } else if (auto *MemRecord = dyn_cast<RecordDecl>(Mem)) {
      if (!MemRecord->isAnonymousStructOrUnion() &&
          MemRecord->getDeclName()) {
        // Visual C++ allows type definition in anonymous struct or union.
        if (getLangOpts().MicrosoftExt)
          Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type)
            << Record->isUnion();
        else {
          // This is a nested type declaration.
          Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
            << Record->isUnion();
          Invalid = true;
        }
      } else {
        // This is an anonymous type definition within another anonymous type.
        // This is a popular extension, provided by Plan9, MSVC and GCC, but
        // not part of standard C++.
        Diag(MemRecord->getLocation(),
             diag::ext_anonymous_record_with_anonymous_type)
          << Record->isUnion();
      }
    } else if (isa<AccessSpecDecl>(Mem)) {
      // Any access specifier is fine.
    } else if (isa<StaticAssertDecl>(Mem)) {
      // In C++1z, static_assert declarations are also fine.
    } else {
      // We have something that isn't a non-static data
      // member. Complain about it.
      unsigned DK = diag::err_anonymous_record_bad_member;
      if (isa<TypeDecl>(Mem))
        DK = diag::err_anonymous_record_with_type;
      else if (isa<FunctionDecl>(Mem))
        DK = diag::err_anonymous_record_with_function;
      else if (isa<VarDecl>(Mem))
        DK = diag::err_anonymous_record_with_static;

      // Visual C++ allows type definition in anonymous struct or union.
      if (getLangOpts().MicrosoftExt &&
          DK == diag::err_anonymous_record_with_type)
        Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type)
          << Record->isUnion();
      else {
        Diag(Mem->getLocation(), DK) << Record->isUnion();
        Invalid = true;
      }
    }
  }

  // C++11 [class.union]p8 (DR1460):
  //   At most one variant member of a union may have a
  //   brace-or-equal-initializer.
  if (cast<CXXRecordDecl>(Record)->hasInClassInitializer() &&
      Owner->isRecord())
    checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Owner),
                              cast<CXXRecordDecl>(Record));
}

if (!Record->isUnion() && !Owner->isRecord()) {
  Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
    << getLangOpts().CPlusPlus;
  Invalid = true;
}

// C++ [dcl.dcl]p3:
//   [If there are no declarators], and except for the declaration of an
//   unnamed bit-field, the decl-specifier-seq shall introduce one or more
//   names into the program
// C++ [class.mem]p2:
//   each such member-declaration shall either declare at least one member
//   name of the class or declare at least one unnamed bit-field
//
// For C this is an error even for a named struct, and is diagnosed elsewhere.
if (getLangOpts().CPlusPlus && Record->field_empty())
  Diag(DS.getBeginLoc(), diag::ext_no_declarators) << DS.getSourceRange();

// Mock up a declarator.
Declarator Dc(DS, DeclaratorContext::Member);
TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
assert(TInfo && "couldn't build declarator info for anonymous struct/union")((void)0);

// Create a declaration for this anonymous struct/union.
NamedDecl *Anon = nullptr;
if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
  Anon = FieldDecl::Create(
      Context, OwningClass, DS.getBeginLoc(), Record->getLocation(),
      /*IdentifierInfo=*/nullptr, Context.getTypeDeclType(Record), TInfo,
      /*BitWidth=*/nullptr, /*Mutable=*/false,
      /*InitStyle=*/ICIS_NoInit);
  Anon->setAccess(AS);
  ProcessDeclAttributes(S, Anon, Dc);

  if (getLangOpts().CPlusPlus)
    FieldCollector->Add(cast<FieldDecl>(Anon));
} else {
  DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
  StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
  if (SCSpec == DeclSpec::SCS_mutable) {
    // mutable can only appear on non-static class members, so it's always
    // an error here
    Diag(Record->getLocation(), diag::err_mutable_nonmember);
    Invalid = true;
    SC = SC_None;
  }

  assert(DS.getAttributes().empty() && "No attribute expected")((void)0);
  Anon = VarDecl::Create(Context, Owner, DS.getBeginLoc(),
                         Record->getLocation(), /*IdentifierInfo=*/nullptr,
                         Context.getTypeDeclType(Record), TInfo, SC);

  // Default-initialize the implicit variable. This initialization will be
  // trivial in almost all cases, except if a union member has an in-class
  // initializer:
  //   union { int n = 0; };
  if (!Invalid)
    ActOnUninitializedDecl(Anon);
}
Anon->setImplicit();

// Mark this as an anonymous struct/union type.
Record->setAnonymousStructOrUnion(true);

// Add the anonymous struct/union object to the current
// context. We'll be referencing this object when we refer to one of
// its members.
Owner->addDecl(Anon);

// Inject the members of the anonymous struct/union into the owning
// context and into the identifier resolver chain for name lookup
// purposes.
SmallVector<NamedDecl*, 2> Chain;
Chain.push_back(Anon);

if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, Chain))
  Invalid = true;

if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
  if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
    MangleNumberingContext *MCtx;
    Decl *ManglingContextDecl;
    std::tie(MCtx, ManglingContextDecl) =
        getCurrentMangleNumberContext(NewVD->getDeclContext());
    if (MCtx) {
      Context.setManglingNumber(
          NewVD, MCtx->getManglingNumber(
                     NewVD, getMSManglingNumber(getLangOpts(), S)));
      Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
    }
  }
}

if (Invalid)
  Anon->setInvalidDecl();

return Anon;
5325}

5327/// BuildMicrosoftCAnonymousStruct - Handle the declaration of an
5328/// Microsoft C anonymous structure.
5329/// Ref: http://msdn.microsoft.com/en-us/library/z2cx9y4f.aspx
5330/// Example:
5331///
5332/// struct A { int a; };
5333/// struct B { struct A; int b; };
5334///
5335/// void foo() {
5336///   B var;
5337///   var.a = 3;
5338/// }
5339///
5340Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
                                         RecordDecl *Record) {
assert(Record && "expected a record!")((void)0);

// Mock up a declarator.
Declarator Dc(DS, DeclaratorContext::TypeName);
TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
assert(TInfo && "couldn't build declarator info for anonymous struct")((void)0);

auto *ParentDecl = cast<RecordDecl>(CurContext);
QualType RecTy = Context.getTypeDeclType(Record);

// Create a declaration for this anonymous struct.
NamedDecl *Anon =
    FieldDecl::Create(Context, ParentDecl, DS.getBeginLoc(), DS.getBeginLoc(),
                      /*IdentifierInfo=*/nullptr, RecTy, TInfo,
                      /*BitWidth=*/nullptr, /*Mutable=*/false,
                      /*InitStyle=*/ICIS_NoInit);
Anon->setImplicit();

// Add the anonymous struct object to the current context.
CurContext->addDecl(Anon);

// Inject the members of the anonymous struct into the current
// context and into the identifier resolver chain for name lookup
// purposes.
SmallVector<NamedDecl*, 2> Chain;
Chain.push_back(Anon);

RecordDecl *RecordDef = Record->getDefinition();
if (RequireCompleteSizedType(Anon->getLocation(), RecTy,
                             diag::err_field_incomplete_or_sizeless) ||
    InjectAnonymousStructOrUnionMembers(*this, S, CurContext, RecordDef,
                                        AS_none, Chain)) {
  Anon->setInvalidDecl();
  ParentDecl->setInvalidDecl();
}

return Anon;
5379}

5381/// GetNameForDeclarator - Determine the full declaration name for the
5382/// given Declarator.
5383DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
return GetNameFromUnqualifiedId(D.getName());
8
←
Returning without writing to 'D.Redeclaration', which participates in a condition later→
19
←
Returning without writing to 'D.Redeclaration', which participates in a condition later→
5385}

5387/// Retrieves the declaration name from a parsed unqualified-id.
5388DeclarationNameInfo
5389Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
DeclarationNameInfo NameInfo;
NameInfo.setLoc(Name.StartLocation);

switch (Name.getKind()) {

case UnqualifiedIdKind::IK_ImplicitSelfParam:
case UnqualifiedIdKind::IK_Identifier:
  NameInfo.setName(Name.Identifier);
  return NameInfo;

case UnqualifiedIdKind::IK_DeductionGuideName: {
  // C++ [temp.deduct.guide]p3:
  //   The simple-template-id shall name a class template specialization.
  //   The template-name shall be the same identifier as the template-name
  //   of the simple-template-id.
  // These together intend to imply that the template-name shall name a
  // class template.
  // FIXME: template<typename T> struct X {};
  //        template<typename T> using Y = X<T>;
  //        Y(int) -> Y<int>;
  //   satisfies these rules but does not name a class template.
  TemplateName TN = Name.TemplateName.get().get();
  auto *Template = TN.getAsTemplateDecl();
  if (!Template || !isa<ClassTemplateDecl>(Template)) {
    Diag(Name.StartLocation,
         diag::err_deduction_guide_name_not_class_template)
      << (int)getTemplateNameKindForDiagnostics(TN) << TN;
    if (Template)
      Diag(Template->getLocation(), diag::note_template_decl_here);
    return DeclarationNameInfo();
  }

  NameInfo.setName(
      Context.DeclarationNames.getCXXDeductionGuideName(Template));
  return NameInfo;
}

case UnqualifiedIdKind::IK_OperatorFunctionId:
  NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
                                         Name.OperatorFunctionId.Operator));
  NameInfo.setCXXOperatorNameRange(SourceRange(
      Name.OperatorFunctionId.SymbolLocations[0], Name.EndLocation));
  return NameInfo;

case UnqualifiedIdKind::IK_LiteralOperatorId:
  NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
                                                         Name.Identifier));
  NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
  return NameInfo;

case UnqualifiedIdKind::IK_ConversionFunctionId: {
  TypeSourceInfo *TInfo;
  QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo);
  if (Ty.isNull())
    return DeclarationNameInfo();
  NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
                                             Context.getCanonicalType(Ty)));
  NameInfo.setNamedTypeInfo(TInfo);
  return NameInfo;
}

case UnqualifiedIdKind::IK_ConstructorName: {
  TypeSourceInfo *TInfo;
  QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo);
  if (Ty.isNull())
    return DeclarationNameInfo();
  NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
                                            Context.getCanonicalType(Ty)));
  NameInfo.setNamedTypeInfo(TInfo);
  return NameInfo;
}

case UnqualifiedIdKind::IK_ConstructorTemplateId: {
  // In well-formed code, we can only have a constructor
  // template-id that refers to the current context, so go there
  // to find the actual type being constructed.
  CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext);
  if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
    return DeclarationNameInfo();

  // Determine the type of the class being constructed.
  QualType CurClassType = Context.getTypeDeclType(CurClass);

  // FIXME: Check two things: that the template-id names the same type as
  // CurClassType, and that the template-id does not occur when the name
  // was qualified.

  NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
                                  Context.getCanonicalType(CurClassType)));
  // FIXME: should we retrieve TypeSourceInfo?
  NameInfo.setNamedTypeInfo(nullptr);
  return NameInfo;
}

case UnqualifiedIdKind::IK_DestructorName: {
  TypeSourceInfo *TInfo;
  QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo);
  if (Ty.isNull())
    return DeclarationNameInfo();
  NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
                                            Context.getCanonicalType(Ty)));
  NameInfo.setNamedTypeInfo(TInfo);
  return NameInfo;
}

case UnqualifiedIdKind::IK_TemplateId: {
  TemplateName TName = Name.TemplateId->Template.get();
  SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
  return Context.getNameForTemplate(TName, TNameLoc);
}

} // switch (Name.getKind())

llvm_unreachable("Unknown name kind")__builtin_unreachable();
5504}

5506static QualType getCoreType(QualType Ty) {
do {
  if (Ty->isPointerType() || Ty->isReferenceType())
    Ty = Ty->getPointeeType();
  else if (Ty->isArrayType())
    Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
  else
    return Ty.withoutLocalFastQualifiers();
} while (true);
5515}

5517/// hasSimilarParameters - Determine whether the C++ functions Declaration
5518/// and Definition have "nearly" matching parameters. This heuristic is
5519/// used to improve diagnostics in the case where an out-of-line function
5520/// definition doesn't match any declaration within the class or namespace.
5521/// Also sets Params to the list of indices to the parameters that differ
5522/// between the declaration and the definition. If hasSimilarParameters
5523/// returns true and Params is empty, then all of the parameters match.
5524static bool hasSimilarParameters(ASTContext &Context,
                                   FunctionDecl *Declaration,
                                   FunctionDecl *Definition,
                                   SmallVectorImpl<unsigned> &Params) {
Params.clear();
if (Declaration->param_size() != Definition->param_size())
  return false;
for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
  QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
  QualType DefParamTy = Definition->getParamDecl(Idx)->getType();

  // The parameter types are identical
  if (Context.hasSameUnqualifiedType(DefParamTy, DeclParamTy))
    continue;

  QualType DeclParamBaseTy = getCoreType(DeclParamTy);
  QualType DefParamBaseTy = getCoreType(DefParamTy);
  const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
  const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();

  if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) ||
      (DeclTyName && DeclTyName == DefTyName))
    Params.push_back(Idx);
  else  // The two parameters aren't even close
    return false;
}

return true;
5552}

5554/// NeedsRebuildingInCurrentInstantiation - Checks whether the given
5555/// declarator needs to be rebuilt in the current instantiation.
5556/// Any bits of declarator which appear before the name are valid for
5557/// consideration here.  That's specifically the type in the decl spec
5558/// and the base type in any member-pointer chunks.
5559static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
                                                  DeclarationName Name) {
// The types we specifically need to rebuild are:
//   - typenames, typeofs, and decltypes
//   - types which will become injected class names
// Of course, we also need to rebuild any type referencing such a
// type.  It's safest to just say "dependent", but we call out a
// few cases here.

DeclSpec &DS = D.getMutableDeclSpec();
switch (DS.getTypeSpecType()) {
case DeclSpec::TST_typename:
case DeclSpec::TST_typeofType:
case DeclSpec::TST_underlyingType:
case DeclSpec::TST_atomic: {
  // Grab the type from the parser.
  TypeSourceInfo *TSI = nullptr;
  QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
  if (T.isNull() || !T->isInstantiationDependentType()) break;

  // Make sure there's a type source info.  This isn't really much
  // of a waste; most dependent types should have type source info
  // attached already.
  if (!TSI)
    TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc());

  // Rebuild the type in the current instantiation.
  TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name);
  if (!TSI) return true;

  // Store the new type back in the decl spec.
  ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI);
  DS.UpdateTypeRep(LocType);
  break;
}

case DeclSpec::TST_decltype:
case DeclSpec::TST_typeofExpr: {
  Expr *E = DS.getRepAsExpr();
  ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
  if (Result.isInvalid()) return true;
  DS.UpdateExprRep(Result.get());
  break;
}

default:
  // Nothing to do for these decl specs.
  break;
}

// It doesn't matter what order we do this in.
for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
  DeclaratorChunk &Chunk = D.getTypeObject(I);

  // The only type information in the declarator which can come
  // before the declaration name is the base type of a member
  // pointer.
  if (Chunk.Kind != DeclaratorChunk::MemberPointer)
    continue;

  // Rebuild the scope specifier in-place.
  CXXScopeSpec &SS = Chunk.Mem.Scope();
  if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
    return true;
}

return false;
5626}

5628void Sema::warnOnReservedIdentifier(const NamedDecl *D) {
// Avoid warning twice on the same identifier, and don't warn on redeclaration
// of system decl.
if (D->getPreviousDecl() || D->isImplicit())
  return;
ReservedIdentifierStatus Status = D->isReserved(getLangOpts());
if (Status != ReservedIdentifierStatus::NotReserved &&
    !Context.getSourceManager().isInSystemHeader(D->getLocation()))
  Diag(D->getLocation(), diag::warn_reserved_extern_symbol)
      << D << static_cast<int>(Status);
5638}

5640Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
D.setFunctionDefinitionKind(FunctionDefinitionKind::Declaration);
Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());

if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
    Dcl && Dcl->getDeclContext()->isFileContext())
  Dcl->setTopLevelDeclInObjCContainer();

return Dcl;
5649}

5651/// DiagnoseClassNameShadow - Implement C++ [class.mem]p13:
5652///   If T is the name of a class, then each of the following shall have a
5653///   name different from T:
5654///     - every static data member of class T;
5655///     - every member function of class T
5656///     - every member of class T that is itself a type;
5657/// \returns true if the declaration name violates these rules.
5658bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
                                 DeclarationNameInfo NameInfo) {
DeclarationName Name = NameInfo.getName();

CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC);
while (Record && Record->isAnonymousStructOrUnion())
  Record = dyn_cast<CXXRecordDecl>(Record->getParent());
if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
  Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name;
  return true;
}

return false;
5671}

5673/// Diagnose a declaration whose declarator-id has the given
5674/// nested-name-specifier.
5675///
5676/// \param SS The nested-name-specifier of the declarator-id.
5677///
5678/// \param DC The declaration context to which the nested-name-specifier
5679/// resolves.
5680///
5681/// \param Name The name of the entity being declared.
5682///
5683/// \param Loc The location of the name of the entity being declared.
5684///
5685/// \param IsTemplateId Whether the name is a (simple-)template-id, and thus
5686/// we're declaring an explicit / partial specialization / instantiation.
5687///
5688/// \returns true if we cannot safely recover from this error, false otherwise.
5689bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
                                      DeclarationName Name,
                                      SourceLocation Loc, bool IsTemplateId) {
DeclContext *Cur = CurContext;
while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
  Cur = Cur->getParent();

// If the user provided a superfluous scope specifier that refers back to the
// class in which the entity is already declared, diagnose and ignore it.
//
// class X {
//   void X::f();
// };
//
// Note, it was once ill-formed to give redundant qualification in all
// contexts, but that rule was removed by DR482.
if (Cur->Equals(DC)) {
  if (Cur->isRecord()) {
    Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
                                    : diag::err_member_extra_qualification)
      << Name << FixItHint::CreateRemoval(SS.getRange());
    SS.clear();
  } else {
    Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name;
  }
  return false;
}

// Check whether the qualifying scope encloses the scope of the original
// declaration. For a template-id, we perform the checks in
// CheckTemplateSpecializationScope.
if (!Cur->Encloses(DC) && !IsTemplateId) {
  if (Cur->isRecord())
    Diag(Loc, diag::err_member_qualification)
      << Name << SS.getRange();
  else if (isa<TranslationUnitDecl>(DC))
    Diag(Loc, diag::err_invalid_declarator_global_scope)
      << Name << SS.getRange();
  else if (isa<FunctionDecl>(Cur))
    Diag(Loc, diag::err_invalid_declarator_in_function)
      << Name << SS.getRange();
  else if (isa<BlockDecl>(Cur))
    Diag(Loc, diag::err_invalid_declarator_in_block)
      << Name << SS.getRange();
  else
    Diag(Loc, diag::err_invalid_declarator_scope)
    << Name << cast<NamedDecl>(Cur) << cast<NamedDecl>(DC) << SS.getRange();

  return true;
}

if (Cur->isRecord()) {
  // Cannot qualify members within a class.
  Diag(Loc, diag::err_member_qualification)
    << Name << SS.getRange();
  SS.clear();

  // C++ constructors and destructors with incorrect scopes can break
  // our AST invariants by having the wrong underlying types. If
  // that's the case, then drop this declaration entirely.
  if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
       Name.getNameKind() == DeclarationName::CXXDestructorName) &&
      !Context.hasSameType(Name.getCXXNameType(),
                           Context.getTypeDeclType(cast<CXXRecordDecl>(Cur))))
    return true;

  return false;
}

// C++11 [dcl.meaning]p1:
//   [...] "The nested-name-specifier of the qualified declarator-id shall
//   not begin with a decltype-specifer"
NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
while (SpecLoc.getPrefix())
  SpecLoc = SpecLoc.getPrefix();
if (dyn_cast_or_null<DecltypeType>(
      SpecLoc.getNestedNameSpecifier()->getAsType()))
  Diag(Loc, diag::err_decltype_in_declarator)
    << SpecLoc.getTypeLoc().getSourceRange();

return false;
5770}

5772NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
                                MultiTemplateParamsArg TemplateParamLists) {
// TODO: consider using NameInfo for diagnostic.
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();

// All of these full declarators require an identifier.  If it doesn't have
// one, the ParsedFreeStandingDeclSpec action should be used.
if (D.isDecompositionDeclarator()) {
  return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
} else if (!Name) {
  if (!D.isInvalidType())  // Reject this if we think it is valid.
    Diag(D.getDeclSpec().getBeginLoc(), diag::err_declarator_need_ident)
        << D.getDeclSpec().getSourceRange() << D.getSourceRange();
  return nullptr;
} else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType))
  return nullptr;

// The scope passed in may not be a decl scope.  Zip up the scope tree until
// we find one that is.
while ((S->getFlags() & Scope::DeclScope) == 0 ||
       (S->getFlags() & Scope::TemplateParamScope) != 0)
  S = S->getParent();

DeclContext *DC = CurContext;
if (D.getCXXScopeSpec().isInvalid())
  D.setInvalidType();
else if (D.getCXXScopeSpec().isSet()) {
  if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(),
                                      UPPC_DeclarationQualifier))
    return nullptr;

  bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
  DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext);
  if (!DC || isa<EnumDecl>(DC)) {
    // If we could not compute the declaration context, it's because the
    // declaration context is dependent but does not refer to a class,
    // class template, or class template partial specialization. Complain
    // and return early, to avoid the coming semantic disaster.
    Diag(D.getIdentifierLoc(),
         diag::err_template_qualified_declarator_no_match)
      << D.getCXXScopeSpec().getScopeRep()
      << D.getCXXScopeSpec().getRange();
    return nullptr;
  }
  bool IsDependentContext = DC->isDependentContext();

  if (!IsDependentContext &&
      RequireCompleteDeclContext(D.getCXXScopeSpec(), DC))
    return nullptr;

  // If a class is incomplete, do not parse entities inside it.
  if (isa<CXXRecordDecl>(DC) && !cast<CXXRecordDecl>(DC)->hasDefinition()) {
    Diag(D.getIdentifierLoc(),
         diag::err_member_def_undefined_record)
      << Name << DC << D.getCXXScopeSpec().getRange();
    return nullptr;
  }
  if (!D.getDeclSpec().isFriendSpecified()) {
    if (diagnoseQualifiedDeclaration(
            D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(),
            D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) {
      if (DC->isRecord())
        return nullptr;

      D.setInvalidType();
    }
  }

  // Check whether we need to rebuild the type of the given
  // declaration in the current instantiation.
  if (EnteringContext && IsDependentContext &&
      TemplateParamLists.size() != 0) {
    ContextRAII SavedContext(*this, DC);
    if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name))
      D.setInvalidType();
  }
}

TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
QualType R = TInfo->getType();

if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
                                    UPPC_DeclarationType))
  D.setInvalidType();

LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                      forRedeclarationInCurContext());

// See if this is a redefinition of a variable in the same scope.
if (!D.getCXXScopeSpec().isSet()) {
  bool IsLinkageLookup = false;
  bool CreateBuiltins = false;

  // If the declaration we're planning to build will be a function
  // or object with linkage, then look for another declaration with
  // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
  //
  // If the declaration we're planning to build will be declared with
  // external linkage in the translation unit, create any builtin with
  // the same name.
  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
    /* Do nothing*/;
  else if (CurContext->isFunctionOrMethod() &&
           (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
            R->isFunctionType())) {
    IsLinkageLookup = true;
    CreateBuiltins =
        CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
  } else if (CurContext->getRedeclContext()->isTranslationUnit() &&
             D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
    CreateBuiltins = true;

  if (IsLinkageLookup) {
    Previous.clear(LookupRedeclarationWithLinkage);
    Previous.setRedeclarationKind(ForExternalRedeclaration);
  }

  LookupName(Previous, S, CreateBuiltins);
} else { // Something like "int foo::x;"
  LookupQualifiedName(Previous, DC);

  // C++ [dcl.meaning]p1:
  //   When the declarator-id is qualified, the declaration shall refer to a
  //  previously declared member of the class or namespace to which the
  //  qualifier refers (or, in the case of a namespace, of an element of the
  //  inline namespace set of that namespace (7.3.1)) or to a specialization
  //  thereof; [...]
  //
  // Note that we already checked the context above, and that we do not have
  // enough information to make sure that Previous contains the declaration
  // we want to match. For example, given:
  //
  //   class X {
  //     void f();
  //     void f(float);
  //   };
  //
  //   void X::f(int) { } // ill-formed
  //
  // In this case, Previous will point to the overload set
  // containing the two f's declared in X, but neither of them
  // matches.

  // C++ [dcl.meaning]p1:
  //   [...] the member shall not merely have been introduced by a
  //   using-declaration in the scope of the class or namespace nominated by
  //   the nested-name-specifier of the declarator-id.
  RemoveUsingDecls(Previous);
}

if (Previous.isSingleResult() &&
    Previous.getFoundDecl()->isTemplateParameter()) {
  // Maybe we will complain about the shadowed template parameter.
  if (!D.isInvalidType())
    DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
                                    Previous.getFoundDecl());

  // Just pretend that we didn't see the previous declaration.
  Previous.clear();
}

if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
  // Forget that the previous declaration is the injected-class-name.
  Previous.clear();

// In C++, the previous declaration we find might be a tag type
// (class or enum). In this case, the new declaration will hide the
// tag type. Note that this applies to functions, function templates, and
// variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
if (Previous.isSingleTagDecl() &&
    D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
    (TemplateParamLists.size() == 0 || R->isFunctionType()))
  Previous.clear();

// Check that there are no default arguments other than in the parameters
// of a function declaration (C++ only).
if (getLangOpts().CPlusPlus)
  CheckExtraCXXDefaultArguments(D);

NamedDecl *New;

bool AddToScope = true;
if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
  if (TemplateParamLists.size()) {
    Diag(D.getIdentifierLoc(), diag::err_template_typedef);
    return nullptr;
  }

  New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
} else if (R->isFunctionType()) {
  New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
                                TemplateParamLists,
                                AddToScope);
} else {
  New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
                                AddToScope);
}

if (!New)
  return nullptr;

// If this has an identifier and is not a function template specialization,
// add it to the scope stack.
if (New->getDeclName() && AddToScope)
  PushOnScopeChains(New, S);

if (isInOpenMPDeclareTargetContext())
  checkDeclIsAllowedInOpenMPTarget(nullptr, New);

return New;
5983}

5985/// Helper method to turn variable array types into constant array
5986/// types in certain situations which would otherwise be errors (for
5987/// GCC compatibility).
5988static QualType TryToFixInvalidVariablyModifiedType(QualType T,
                                                  ASTContext &Context,
                                                  bool &SizeIsNegative,
                                                  llvm::APSInt &Oversized) {
// This method tries to turn a variable array into a constant
// array even when the size isn't an ICE.  This is necessary
// for compatibility with code that depends on gcc's buggy
// constant expression folding, like struct {char x[(int)(char*)2];}
SizeIsNegative = false;
Oversized = 0;

if (T->isDependentType())
  return QualType();

QualifierCollector Qs;
const Type *Ty = Qs.strip(T);

if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) {
  QualType Pointee = PTy->getPointeeType();
  QualType FixedType =
      TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative,
                                          Oversized);
  if (FixedType.isNull()) return FixedType;
  FixedType = Context.getPointerType(FixedType);
  return Qs.apply(Context, FixedType);
}
if (const ParenType* PTy = dyn_cast<ParenType>(Ty)) {
  QualType Inner = PTy->getInnerType();
  QualType FixedType =
      TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative,
                                          Oversized);
  if (FixedType.isNull()) return FixedType;
  FixedType = Context.getParenType(FixedType);
  return Qs.apply(Context, FixedType);
}

const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
if (!VLATy)
  return QualType();

QualType ElemTy = VLATy->getElementType();
if (ElemTy->isVariablyModifiedType()) {
  ElemTy = TryToFixInvalidVariablyModifiedType(ElemTy, Context,
                                               SizeIsNegative, Oversized);
  if (ElemTy.isNull())
    return QualType();
}

Expr::EvalResult Result;
if (!VLATy->getSizeExpr() ||
    !VLATy->getSizeExpr()->EvaluateAsInt(Result, Context))
  return QualType();

llvm::APSInt Res = Result.Val.getInt();

// Check whether the array size is negative.
if (Res.isSigned() && Res.isNegative()) {
  SizeIsNegative = true;
  return QualType();
}

// Check whether the array is too large to be addressed.
unsigned ActiveSizeBits =
    (!ElemTy->isDependentType() && !ElemTy->isVariablyModifiedType() &&
     !ElemTy->isIncompleteType() && !ElemTy->isUndeducedType())
        ? ConstantArrayType::getNumAddressingBits(Context, ElemTy, Res)
        : Res.getActiveBits();
if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
  Oversized = Res;
  return QualType();
}

QualType FoldedArrayType = Context.getConstantArrayType(
    ElemTy, Res, VLATy->getSizeExpr(), ArrayType::Normal, 0);
return Qs.apply(Context, FoldedArrayType);
6063}

6065static void
6066FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
SrcTL = SrcTL.getUnqualifiedLoc();
DstTL = DstTL.getUnqualifiedLoc();
if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
  PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
  FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(),
                                    DstPTL.getPointeeLoc());
  DstPTL.setStarLoc(SrcPTL.getStarLoc());
  return;
}
if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
  ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
  FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(),
                                    DstPTL.getInnerLoc());
  DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
  DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
  return;
}
ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
TypeLoc SrcElemTL = SrcATL.getElementLoc();
TypeLoc DstElemTL = DstATL.getElementLoc();
if (VariableArrayTypeLoc SrcElemATL =
        SrcElemTL.getAs<VariableArrayTypeLoc>()) {
  ConstantArrayTypeLoc DstElemATL = DstElemTL.castAs<ConstantArrayTypeLoc>();
  FixInvalidVariablyModifiedTypeLoc(SrcElemATL, DstElemATL);
} else {
  DstElemTL.initializeFullCopy(SrcElemTL);
}
DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
DstATL.setSizeExpr(SrcATL.getSizeExpr());
DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
6098}

6100/// Helper method to turn variable array types into constant array
6101/// types in certain situations which would otherwise be errors (for
6102/// GCC compatibility).
6103static TypeSourceInfo*
6104TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
                                            ASTContext &Context,
                                            bool &SizeIsNegative,
                                            llvm::APSInt &Oversized) {
QualType FixedTy
  = TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context,
                                        SizeIsNegative, Oversized);
if (FixedTy.isNull())
  return nullptr;
TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy);
FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(),
                                  FixedTInfo->getTypeLoc());
return FixedTInfo;
6117}

6119/// Attempt to fold a variable-sized type to a constant-sized type, returning
6120/// true if we were successful.
6121bool Sema::tryToFixVariablyModifiedVarType(TypeSourceInfo *&TInfo,
                                         QualType &T, SourceLocation Loc,
                                         unsigned FailedFoldDiagID) {
bool SizeIsNegative;
llvm::APSInt Oversized;
TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
    TInfo, Context, SizeIsNegative, Oversized);
if (FixedTInfo) {
  Diag(Loc, diag::ext_vla_folded_to_constant);
  TInfo = FixedTInfo;
  T = FixedTInfo->getType();
  return true;
}

if (SizeIsNegative)
  Diag(Loc, diag::err_typecheck_negative_array_size);
else if (Oversized.getBoolValue())
  Diag(Loc, diag::err_array_too_large) << toString(Oversized, 10);
else if (FailedFoldDiagID)
  Diag(Loc, FailedFoldDiagID);
return false;
6142}

6144/// Register the given locally-scoped extern "C" declaration so
6145/// that it can be found later for redeclarations. We include any extern "C"
6146/// declaration that is not visible in the translation unit here, not just
6147/// function-scope declarations.
6148void
6149Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) {
if (!getLangOpts().CPlusPlus &&
    ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit())
  // Don't need to track declarations in the TU in C.
  return;

// Note that we have a locally-scoped external with this name.
Context.getExternCContextDecl()->makeDeclVisibleInContext(ND);
6157}

6159NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) {
// FIXME: We can have multiple results via __attribute__((overloadable)).
auto Result = Context.getExternCContextDecl()->lookup(Name);
return Result.empty() ? nullptr : *Result.begin();
6163}

6165/// Diagnose function specifiers on a declaration of an identifier that
6166/// does not identify a function.
6167void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) {
// FIXME: We should probably indicate the identifier in question to avoid
// confusion for constructs like "virtual int a(), b;"
if (DS.isVirtualSpecified())
  Diag(DS.getVirtualSpecLoc(),
       diag::err_virtual_non_function);

if (DS.hasExplicitSpecifier())
  Diag(DS.getExplicitSpecLoc(),
       diag::err_explicit_non_function);

if (DS.isNoreturnSpecified())
  Diag(DS.getNoreturnSpecLoc(),
       diag::err_noreturn_non_function);
6181}

6183NamedDecl*
6184Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
                           TypeSourceInfo *TInfo, LookupResult &Previous) {
// Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
if (D.getCXXScopeSpec().isSet()) {
  Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator)
    << D.getCXXScopeSpec().getRange();
  D.setInvalidType();
  // Pretend we didn't see the scope specifier.
  DC = CurContext;
  Previous.clear();
}

DiagnoseFunctionSpecifiers(D.getDeclSpec());

if (D.getDeclSpec().isInlineSpecified())
  Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
      << getLangOpts().CPlusPlus17;
if (D.getDeclSpec().hasConstexprSpecifier())
  Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_invalid_constexpr)
      << 1 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());

if (D.getName().Kind != UnqualifiedIdKind::IK_Identifier) {
  if (D.getName().Kind == UnqualifiedIdKind::IK_DeductionGuideName)
    Diag(D.getName().StartLocation,
         diag::err_deduction_guide_invalid_specifier)
        << "typedef";
  else
    Diag(D.getName().StartLocation, diag::err_typedef_not_identifier)
        << D.getName().getSourceRange();
  return nullptr;
}

TypedefDecl *NewTD = ParseTypedefDecl(S, D, TInfo->getType(), TInfo);
if (!NewTD) return nullptr;

// Handle attributes prior to checking for duplicates in MergeVarDecl
ProcessDeclAttributes(S, NewTD, D);

CheckTypedefForVariablyModifiedType(S, NewTD);

bool Redeclaration = D.isRedeclaration();
NamedDecl *ND = ActOnTypedefNameDecl(S, DC, NewTD, Previous, Redeclaration);
D.setRedeclaration(Redeclaration);
return ND;
6228}

6230void
6231Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) {
// C99 6.7.7p2: If a typedef name specifies a variably modified type
// then it shall have block scope.
// Note that variably modified types must be fixed before merging the decl so
// that redeclarations will match.
TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo();
QualType T = TInfo->getType();
if (T->isVariablyModifiedType()) {
  setFunctionHasBranchProtectedScope();

  if (S->getFnParent() == nullptr) {
    bool SizeIsNegative;
    llvm::APSInt Oversized;
    TypeSourceInfo *FixedTInfo =
      TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
                                                    SizeIsNegative,
                                                    Oversized);
    if (FixedTInfo) {
      Diag(NewTD->getLocation(), diag::ext_vla_folded_to_constant);
      NewTD->setTypeSourceInfo(FixedTInfo);
    } else {
      if (SizeIsNegative)
        Diag(NewTD->getLocation(), diag::err_typecheck_negative_array_size);
      else if (T->isVariableArrayType())
        Diag(NewTD->getLocation(), diag::err_vla_decl_in_file_scope);
      else if (Oversized.getBoolValue())
        Diag(NewTD->getLocation(), diag::err_array_too_large)
          << toString(Oversized, 10);
      else
        Diag(NewTD->getLocation(), diag::err_vm_decl_in_file_scope);
      NewTD->setInvalidDecl();
    }
  }
}
6265}

6267/// ActOnTypedefNameDecl - Perform semantic checking for a declaration which
6268/// declares a typedef-name, either using the 'typedef' type specifier or via
6269/// a C++0x [dcl.typedef]p2 alias-declaration: 'using T = A;'.
6270NamedDecl*
6271Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
                         LookupResult &Previous, bool &Redeclaration) {

// Find the shadowed declaration before filtering for scope.
NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous);

// Merge the decl with the existing one if appropriate. If the decl is
// in an outer scope, it isn't the same thing.
FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false,
                     /*AllowInlineNamespace*/false);
filterNonConflictingPreviousTypedefDecls(*this, NewTD, Previous);
if (!Previous.empty()) {
  Redeclaration = true;
  MergeTypedefNameDecl(S, NewTD, Previous);
} else {
  inferGslPointerAttribute(NewTD);
}

if (ShadowedDecl && !Redeclaration)
  CheckShadow(NewTD, ShadowedDecl, Previous);

// If this is the C FILE type, notify the AST context.
if (IdentifierInfo *II = NewTD->getIdentifier())
  if (!NewTD->isInvalidDecl() &&
      NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
    if (II->isStr("FILE"))
      Context.setFILEDecl(NewTD);
    else if (II->isStr("jmp_buf"))
      Context.setjmp_bufDecl(NewTD);
    else if (II->isStr("sigjmp_buf"))
      Context.setsigjmp_bufDecl(NewTD);
    else if (II->isStr("ucontext_t"))
      Context.setucontext_tDecl(NewTD);
  }

return NewTD;
6307}

6309/// Determines whether the given declaration is an out-of-scope
6310/// previous declaration.
6311///
6312/// This routine should be invoked when name lookup has found a
6313/// previous declaration (PrevDecl) that is not in the scope where a
6314/// new declaration by the same name is being introduced. If the new
6315/// declaration occurs in a local scope, previous declarations with
6316/// linkage may still be considered previous declarations (C99
6317/// 6.2.2p4-5, C++ [basic.link]p6).
6318///
6319/// \param PrevDecl the previous declaration found by name
6320/// lookup
6321///
6322/// \param DC the context in which the new declaration is being
6323/// declared.
6324///
6325/// \returns true if PrevDecl is an out-of-scope previous declaration
6326/// for a new delcaration with the same name.
6327static bool
6328isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
                              ASTContext &Context) {
if (!PrevDecl)
  return false;

if (!PrevDecl->hasLinkage())
  return false;

if (Context.getLangOpts().CPlusPlus) {
  // C++ [basic.link]p6:
  //   If there is a visible declaration of an entity with linkage
  //   having the same name and type, ignoring entities declared
  //   outside the innermost enclosing namespace scope, the block
  //   scope declaration declares that same entity and receives the
  //   linkage of the previous declaration.
  DeclContext *OuterContext = DC->getRedeclContext();
  if (!OuterContext->isFunctionOrMethod())
    // This rule only applies to block-scope declarations.
    return false;

  DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
  if (PrevOuterContext->isRecord())
    // We found a member function: ignore it.
    return false;

  // Find the innermost enclosing namespace for the new and
  // previous declarations.
  OuterContext = OuterContext->getEnclosingNamespaceContext();
  PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext();

  // The previous declaration is in a different namespace, so it
  // isn't the same function.
  if (!OuterContext->Equals(PrevOuterContext))
    return false;
}

return true;
6365}

6367static void SetNestedNameSpecifier(Sema &S, DeclaratorDecl *DD, Declarator &D) {
CXXScopeSpec &SS = D.getCXXScopeSpec();
if (!SS.isSet()) return;
DD->setQualifierInfo(SS.getWithLocInContext(S.Context));
6371}

6373bool Sema::inferObjCARCLifetime(ValueDecl *decl) {
QualType type = decl->getType();
Qualifiers::ObjCLifetime lifetime = type.getObjCLifetime();
if (lifetime == Qualifiers::OCL_Autoreleasing) {
  // Various kinds of declaration aren't allowed to be __autoreleasing.
  unsigned kind = -1U;
  if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
    if (var->hasAttr<BlocksAttr>())
      kind = 0; // __block
    else if (!var->hasLocalStorage())
      kind = 1; // global
  } else if (isa<ObjCIvarDecl>(decl)) {
    kind = 3; // ivar
  } else if (isa<FieldDecl>(decl)) {
    kind = 2; // field
  }

  if (kind != -1U) {
    Diag(decl->getLocation(), diag::err_arc_autoreleasing_var)
      << kind;
  }
} else if (lifetime == Qualifiers::OCL_None) {
  // Try to infer lifetime.
  if (!type->isObjCLifetimeType())
    return false;

  lifetime = type->getObjCARCImplicitLifetime();
  type = Context.getLifetimeQualifiedType(type, lifetime);
  decl->setType(type);
}

if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
  // Thread-local variables cannot have lifetime.
  if (lifetime && lifetime != Qualifiers::OCL_ExplicitNone &&
      var->getTLSKind()) {
    Diag(var->getLocation(), diag::err_arc_thread_ownership)
      << var->getType();
    return true;
  }
}

return false;
6415}

6417void Sema::deduceOpenCLAddressSpace(ValueDecl *Decl) {
if (Decl->getType().hasAddressSpace())
  return;
if (Decl->getType()->isDependentType())
  return;
if (VarDecl *Var = dyn_cast<VarDecl>(Decl)) {
  QualType Type = Var->getType();
  if (Type->isSamplerT() || Type->isVoidType())
    return;
  LangAS ImplAS = LangAS::opencl_private;
  // OpenCL C v3.0 s6.7.8 - For OpenCL C 2.0 or with the
  // __opencl_c_program_scope_global_variables feature, the address space
  // for a variable at program scope or a static or extern variable inside
  // a function are inferred to be __global.
  if (getOpenCLOptions().areProgramScopeVariablesSupported(getLangOpts()) &&
      Var->hasGlobalStorage())
    ImplAS = LangAS::opencl_global;
  // If the original type from a decayed type is an array type and that array
  // type has no address space yet, deduce it now.
  if (auto DT = dyn_cast<DecayedType>(Type)) {
    auto OrigTy = DT->getOriginalType();
    if (!OrigTy.hasAddressSpace() && OrigTy->isArrayType()) {
      // Add the address space to the original array type and then propagate
      // that to the element type through `getAsArrayType`.
      OrigTy = Context.getAddrSpaceQualType(OrigTy, ImplAS);
      OrigTy = QualType(Context.getAsArrayType(OrigTy), 0);
      // Re-generate the decayed type.
      Type = Context.getDecayedType(OrigTy);
    }
  }
  Type = Context.getAddrSpaceQualType(Type, ImplAS);
  // Apply any qualifiers (including address space) from the array type to
  // the element type. This implements C99 6.7.3p8: "If the specification of
  // an array type includes any type qualifiers, the element type is so
  // qualified, not the array type."
  if (Type->isArrayType())
    Type = QualType(Context.getAsArrayType(Type), 0);
  Decl->setType(Type);
}
6456}

6458static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
// Ensure that an auto decl is deduced otherwise the checks below might cache
// the wrong linkage.
assert(S.ParsingInitForAutoVars.count(&ND) == 0)((void)0);

// 'weak' only applies to declarations with external linkage.
if (WeakAttr *Attr = ND.getAttr<WeakAttr>()) {
  if (!ND.isExternallyVisible()) {
    S.Diag(Attr->getLocation(), diag::err_attribute_weak_static);
    ND.dropAttr<WeakAttr>();
  }
}
if (WeakRefAttr *Attr = ND.getAttr<WeakRefAttr>()) {
  if (ND.isExternallyVisible()) {
    S.Diag(Attr->getLocation(), diag::err_attribute_weakref_not_static);
    ND.dropAttr<WeakRefAttr>();
    ND.dropAttr<AliasAttr>();
  }
}

if (auto *VD = dyn_cast<VarDecl>(&ND)) {
  if (VD->hasInit()) {
    if (const auto *Attr = VD->getAttr<AliasAttr>()) {
      assert(VD->isThisDeclarationADefinition() &&((void)0)
             !VD->isExternallyVisible() && "Broken AliasAttr handled late!")((void)0);
      S.Diag(Attr->getLocation(), diag::err_alias_is_definition) << VD << 0;
      VD->dropAttr<AliasAttr>();
    }
  }
}

// 'selectany' only applies to externally visible variable declarations.
// It does not apply to functions.
if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) {
  if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) {
    S.Diag(Attr->getLocation(),
           diag::err_attribute_selectany_non_extern_data);
    ND.dropAttr<SelectAnyAttr>();
  }
}

if (const InheritableAttr *Attr = getDLLAttr(&ND)) {
  auto *VD = dyn_cast<VarDecl>(&ND);
  bool IsAnonymousNS = false;
  bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft();
  if (VD) {
    const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(VD->getDeclContext());
    while (NS && !IsAnonymousNS) {
      IsAnonymousNS = NS->isAnonymousNamespace();
      NS = dyn_cast<NamespaceDecl>(NS->getParent());
    }
  }
  // dll attributes require external linkage. Static locals may have external
  // linkage but still cannot be explicitly imported or exported.
  // In Microsoft mode, a variable defined in anonymous namespace must have
  // external linkage in order to be exported.
  bool AnonNSInMicrosoftMode = IsAnonymousNS && IsMicrosoft;
  if ((ND.isExternallyVisible() && AnonNSInMicrosoftMode) ||
      (!AnonNSInMicrosoftMode &&
       (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())))) {
    S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
      << &ND << Attr;
    ND.setInvalidDecl();
  }
}

// Check the attributes on the function type, if any.
if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
  // Don't declare this variable in the second operand of the for-statement;
  // GCC miscompiles that by ending its lifetime before evaluating the
  // third operand. See gcc.gnu.org/PR86769.
  AttributedTypeLoc ATL;
  for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
       (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
       TL = ATL.getModifiedLoc()) {
    // The [[lifetimebound]] attribute can be applied to the implicit object
    // parameter of a non-static member function (other than a ctor or dtor)
    // by applying it to the function type.
    if (const auto *A = ATL.getAttrAs<LifetimeBoundAttr>()) {
      const auto *MD = dyn_cast<CXXMethodDecl>(FD);
      if (!MD || MD->isStatic()) {
        S.Diag(A->getLocation(), diag::err_lifetimebound_no_object_param)
            << !MD << A->getRange();
      } else if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD)) {
        S.Diag(A->getLocation(), diag::err_lifetimebound_ctor_dtor)
            << isa<CXXDestructorDecl>(MD) << A->getRange();
      }
    }
  }
}
6548}

6550static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
                                         NamedDecl *NewDecl,
                                         bool IsSpecialization,
                                         bool IsDefinition) {
if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
  return;

bool IsTemplate = false;
if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(OldDecl)) {
  OldDecl = OldTD->getTemplatedDecl();
  IsTemplate = true;
  if (!IsSpecialization)
    IsDefinition = false;
}
if (TemplateDecl *NewTD = dyn_cast<TemplateDecl>(NewDecl)) {
  NewDecl = NewTD->getTemplatedDecl();
  IsTemplate = true;
}

if (!OldDecl || !NewDecl)
  return;

const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();
const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();
const DLLImportAttr *NewImportAttr = NewDecl->getAttr<DLLImportAttr>();
const DLLExportAttr *NewExportAttr = NewDecl->getAttr<DLLExportAttr>();

// dllimport and dllexport are inheritable attributes so we have to exclude
// inherited attribute instances.
bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) ||
                  (NewExportAttr && !NewExportAttr->isInherited());

// A redeclaration is not allowed to add a dllimport or dllexport attribute,
// the only exception being explicit specializations.
// Implicitly generated declarations are also excluded for now because there
// is no other way to switch these to use dllimport or dllexport.
bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr;

if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {
  // Allow with a warning for free functions and global variables.
  bool JustWarn = false;
  if (!OldDecl->isCXXClassMember()) {
    auto *VD = dyn_cast<VarDecl>(OldDecl);
    if (VD && !VD->getDescribedVarTemplate())
      JustWarn = true;
    auto *FD = dyn_cast<FunctionDecl>(OldDecl);
    if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate)
      JustWarn = true;
  }

  // We cannot change a declaration that's been used because IR has already
  // been emitted. Dllimported functions will still work though (modulo
  // address equality) as they can use the thunk.
  if (OldDecl->isUsed())
    if (!isa<FunctionDecl>(OldDecl) || !NewImportAttr)
      JustWarn = false;

  unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration
                             : diag::err_attribute_dll_redeclaration;
  S.Diag(NewDecl->getLocation(), DiagID)
      << NewDecl
      << (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr);
  S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
  if (!JustWarn) {
    NewDecl->setInvalidDecl();
    return;
  }
}

// A redeclaration is not allowed to drop a dllimport attribute, the only
// exceptions being inline function definitions (except for function
// templates), local extern declarations, qualified friend declarations or
// special MSVC extension: in the last case, the declaration is treated as if
// it were marked dllexport.
bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
bool IsMicrosoftABI  = S.Context.getTargetInfo().shouldDLLImportComdatSymbols();
if (const auto *VD = dyn_cast<VarDecl>(NewDecl)) {
  // Ignore static data because out-of-line definitions are diagnosed
  // separately.
  IsStaticDataMember = VD->isStaticDataMember();
  IsDefinition = VD->isThisDeclarationADefinition(S.Context) !=
                 VarDecl::DeclarationOnly;
} else if (const auto *FD = dyn_cast<FunctionDecl>(NewDecl)) {
  IsInline = FD->isInlined();
  IsQualifiedFriend = FD->getQualifier() &&
                      FD->getFriendObjectKind() == Decl::FOK_Declared;
}

if (OldImportAttr && !HasNewAttr &&
    (!IsInline || (IsMicrosoftABI && IsTemplate)) && !IsStaticDataMember &&
    !NewDecl->isLocalExternDecl() && !IsQualifiedFriend) {
  if (IsMicrosoftABI && IsDefinition) {
    S.Diag(NewDecl->getLocation(),
           diag::warn_redeclaration_without_import_attribute)
        << NewDecl;
    S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
    NewDecl->dropAttr<DLLImportAttr>();
    NewDecl->addAttr(
        DLLExportAttr::CreateImplicit(S.Context, NewImportAttr->getRange()));
  } else {
    S.Diag(NewDecl->getLocation(),
           diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
        << NewDecl << OldImportAttr;
    S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
    S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute);
    OldDecl->dropAttr<DLLImportAttr>();
    NewDecl->dropAttr<DLLImportAttr>();
  }
} else if (IsInline && OldImportAttr && !IsMicrosoftABI) {
  // In MinGW, seeing a function declared inline drops the dllimport
  // attribute.
  OldDecl->dropAttr<DLLImportAttr>();
  NewDecl->dropAttr<DLLImportAttr>();
  S.Diag(NewDecl->getLocation(),
         diag::warn_dllimport_dropped_from_inline_function)
      << NewDecl << OldImportAttr;
}

// A specialization of a class template member function is processed here
// since it's a redeclaration. If the parent class is dllexport, the
// specialization inherits that attribute. This doesn't happen automatically
// since the parent class isn't instantiated until later.
if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDecl)) {
  if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
      !NewImportAttr && !NewExportAttr) {
    if (const DLLExportAttr *ParentExportAttr =
            MD->getParent()->getAttr<DLLExportAttr>()) {
      DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context);
      NewAttr->setInherited(true);
      NewDecl->addAttr(NewAttr);
    }
  }
}
6683}

6685/// Given that we are within the definition of the given function,
6686/// will that definition behave like C99's 'inline', where the
6687/// definition is discarded except for optimization purposes?
6688static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) {
// Try to avoid calling GetGVALinkageForFunction.

// All cases of this require the 'inline' keyword.
if (!FD->isInlined()) return false;

// This is only possible in C++ with the gnu_inline attribute.
if (S.getLangOpts().CPlusPlus && !FD->hasAttr<GNUInlineAttr>())
  return false;

// Okay, go ahead and call the relatively-more-expensive function.
return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally;
6700}

6702/// Determine whether a variable is extern "C" prior to attaching
6703/// an initializer. We can't just call isExternC() here, because that
6704/// will also compute and cache whether the declaration is externally
6705/// visible, which might change when we attach the initializer.
6706///
6707/// This can only be used if the declaration is known to not be a
6708/// redeclaration of an internal linkage declaration.
6709///
6710/// For instance:
6711///
6712///   auto x = []{};
6713///
6714/// Attaching the initializer here makes this declaration not externally
6715/// visible, because its type has internal linkage.
6716///
6717/// FIXME: This is a hack.
6718template<typename T>
6719static bool isIncompleteDeclExternC(Sema &S, const T *D) {
if (S.getLangOpts().CPlusPlus) {
  // In C++, the overloadable attribute negates the effects of extern "C".
  if (!D->isInExternCContext() || D->template hasAttr<OverloadableAttr>())
    return false;

  // So do CUDA's host/device attributes.
  if (S.getLangOpts().CUDA && (D->template hasAttr<CUDADeviceAttr>() ||
                               D->template hasAttr<CUDAHostAttr>()))
    return false;
}
return D->isExternC();
6731}

6733static bool shouldConsiderLinkage(const VarDecl *VD) {
const DeclContext *DC = VD->getDeclContext()->getRedeclContext();
if (DC->isFunctionOrMethod() || isa<OMPDeclareReductionDecl>(DC) ||
    isa<OMPDeclareMapperDecl>(DC))
  return VD->hasExternalStorage();
if (DC->isFileContext())
  return true;
if (DC->isRecord())
  return false;
if (isa<RequiresExprBodyDecl>(DC))
  return false;
llvm_unreachable("Unexpected context")__builtin_unreachable();
6745}

6747static bool shouldConsiderLinkage(const FunctionDecl *FD) {
const DeclContext *DC = FD->getDeclContext()->getRedeclContext();
if (DC->isFileContext() || DC->isFunctionOrMethod() ||
    isa<OMPDeclareReductionDecl>(DC) || isa<OMPDeclareMapperDecl>(DC))
  return true;
if (DC->isRecord())
  return false;
llvm_unreachable("Unexpected context")__builtin_unreachable();
6755}

6757static bool hasParsedAttr(Scope *S, const Declarator &PD,
                        ParsedAttr::Kind Kind) {
// Check decl attributes on the DeclSpec.
if (PD.getDeclSpec().getAttributes().hasAttribute(Kind))
  return true;

// Walk the declarator structure, checking decl attributes that were in a type
// position to the decl itself.
for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) {
  if (PD.getTypeObject(I).getAttrs().hasAttribute(Kind))
    return true;
}

// Finally, check attributes on the decl itself.
return PD.getAttributes().hasAttribute(Kind);
6772}

6774/// Adjust the \c DeclContext for a function or variable that might be a
6775/// function-local external declaration.
6776bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
if (!DC->isFunctionOrMethod())
  return false;

// If this is a local extern function or variable declared within a function
// template, don't add it into the enclosing namespace scope until it is
// instantiated; it might have a dependent type right now.
if (DC->isDependentContext())
  return true;

// C++11 [basic.link]p7:
//   When a block scope declaration of an entity with linkage is not found to
//   refer to some other declaration, then that entity is a member of the
//   innermost enclosing namespace.
//
// Per C++11 [namespace.def]p6, the innermost enclosing namespace is a
// semantically-enclosing namespace, not a lexically-enclosing one.
while (!DC->isFileContext() && !isa<LinkageSpecDecl>(DC))
  DC = DC->getParent();
return true;
6796}

6798/// Returns true if given declaration has external C language linkage.
6799static bool isDeclExternC(const Decl *D) {
if (const auto *FD = dyn_cast<FunctionDecl>(D))
  return FD->isExternC();
if (const auto *VD = dyn_cast<VarDecl>(D))
  return VD->isExternC();

llvm_unreachable("Unknown type of decl!")__builtin_unreachable();
6806}

6808/// Returns true if there hasn't been any invalid type diagnosed.
6809static bool diagnoseOpenCLTypes(Sema &Se, VarDecl *NewVD) {
DeclContext *DC = NewVD->getDeclContext();
QualType R = NewVD->getType();

// OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
// OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
// argument.
if (R->isImageType() || R->isPipeType()) {
  Se.Diag(NewVD->getLocation(),
          diag::err_opencl_type_can_only_be_used_as_function_parameter)
      << R;
  NewVD->setInvalidDecl();
  return false;
}

// OpenCL v1.2 s6.9.r:
// The event type cannot be used to declare a program scope variable.
// OpenCL v2.0 s6.9.q:
// The clk_event_t and reserve_id_t types cannot be declared in program
// scope.
if (NewVD->hasGlobalStorage() && !NewVD->isStaticLocal()) {
  if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) {
    Se.Diag(NewVD->getLocation(),
            diag::err_invalid_type_for_program_scope_var)
        << R;
    NewVD->setInvalidDecl();
    return false;
  }
}

// OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
if (!Se.getOpenCLOptions().isAvailableOption("__cl_clang_function_pointers",
                                             Se.getLangOpts())) {
  QualType NR = R.getCanonicalType();
  while (NR->isPointerType() || NR->isMemberFunctionPointerType() ||
         NR->isReferenceType()) {
    if (NR->isFunctionPointerType() || NR->isMemberFunctionPointerType() ||
        NR->isFunctionReferenceType()) {
      Se.Diag(NewVD->getLocation(), diag::err_opencl_function_pointer)
          << NR->isReferenceType();
      NewVD->setInvalidDecl();
      return false;
    }
    NR = NR->getPointeeType();
  }
}

if (!Se.getOpenCLOptions().isAvailableOption("cl_khr_fp16",
                                             Se.getLangOpts())) {
  // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and
  // half array type (unless the cl_khr_fp16 extension is enabled).
  if (Se.Context.getBaseElementType(R)->isHalfType()) {
    Se.Diag(NewVD->getLocation(), diag::err_opencl_half_declaration) << R;
    NewVD->setInvalidDecl();
    return false;
  }
}

// OpenCL v1.2 s6.9.r:
// The event type cannot be used with the __local, __constant and __global
// address space qualifiers.
if (R->isEventT()) {
  if (R.getAddressSpace() != LangAS::opencl_private) {
    Se.Diag(NewVD->getBeginLoc(), diag::err_event_t_addr_space_qual);
    NewVD->setInvalidDecl();
    return false;
  }
}

if (R->isSamplerT()) {
  // OpenCL v1.2 s6.9.b p4:
  // The sampler type cannot be used with the __local and __global address
  // space qualifiers.
  if (R.getAddressSpace() == LangAS::opencl_local ||
      R.getAddressSpace() == LangAS::opencl_global) {
    Se.Diag(NewVD->getLocation(), diag::err_wrong_sampler_addressspace);
    NewVD->setInvalidDecl();
  }

  // OpenCL v1.2 s6.12.14.1:
  // A global sampler must be declared with either the constant address
  // space qualifier or with the const qualifier.
  if (DC->isTranslationUnit() &&
      !(R.getAddressSpace() == LangAS::opencl_constant ||
        R.isConstQualified())) {
    Se.Diag(NewVD->getLocation(), diag::err_opencl_nonconst_global_sampler);
    NewVD->setInvalidDecl();
  }
  if (NewVD->isInvalidDecl())
    return false;
}

return true;
6902}

6904template <typename AttrTy>
6905static void copyAttrFromTypedefToDecl(Sema &S, Decl *D, const TypedefType *TT) {
const TypedefNameDecl *TND = TT->getDecl();
if (const auto *Attribute = TND->getAttr<AttrTy>()) {
  AttrTy *Clone = Attribute->clone(S.Context);
  Clone->setInherited(true);
  D->addAttr(Clone);
}
6912}

6914NamedDecl *Sema::ActOnVariableDeclarator(
  Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
  LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
  bool &AddToScope, ArrayRef<BindingDecl *> Bindings) {
QualType R = TInfo->getType();
DeclarationName Name = GetNameForDeclarator(D).getName();

IdentifierInfo *II = Name.getAsIdentifierInfo();

if (D.isDecompositionDeclarator()) {
  // Take the name of the first declarator as our name for diagnostic
  // purposes.
  auto &Decomp = D.getDecompositionDeclarator();
  if (!Decomp.bindings().empty()) {
    II = Decomp.bindings()[0].Name;
    Name = II;
  }
} else if (!II) {
  Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) << Name;
  return nullptr;
}


DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec();
StorageClass SC = StorageClassSpecToVarDeclStorageClass(D.getDeclSpec());

// dllimport globals without explicit storage class are treated as extern. We
// have to change the storage class this early to get the right DeclContext.
if (SC == SC_None && !DC->isRecord() &&
    hasParsedAttr(S, D, ParsedAttr::AT_DLLImport) &&
    !hasParsedAttr(S, D, ParsedAttr::AT_DLLExport))
  SC = SC_Extern;

DeclContext *OriginalDC = DC;
bool IsLocalExternDecl = SC == SC_Extern &&
                         adjustContextForLocalExternDecl(DC);

if (SCSpec == DeclSpec::SCS_mutable) {
  // mutable can only appear on non-static class members, so it's always
  // an error here
  Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
  D.setInvalidType();
  SC = SC_None;
}

if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register &&
    !D.getAsmLabel() && !getSourceManager().isInSystemMacro(
                            D.getDeclSpec().getStorageClassSpecLoc())) {
  // In C++11, the 'register' storage class specifier is deprecated.
  // Suppress the warning in system macros, it's used in macros in some
  // popular C system headers, such as in glibc's htonl() macro.
  Diag(D.getDeclSpec().getStorageClassSpecLoc(),
       getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
                                 : diag::warn_deprecated_register)
    << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
}

DiagnoseFunctionSpecifiers(D.getDeclSpec());

if (!DC->isRecord() && S->getFnParent() == nullptr) {
  // C99 6.9p2: The storage-class specifiers auto and register shall not
  // appear in the declaration specifiers in an external declaration.
  // Global Register+Asm is a GNU extension we support.
  if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) {
    Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope);
    D.setInvalidType();
  }
}

// If this variable has a VLA type and an initializer, try to
// fold to a constant-sized type. This is otherwise invalid.
if (D.hasInitializer() && R->isVariableArrayType())
  tryToFixVariablyModifiedVarType(TInfo, R, D.getIdentifierLoc(),
                                  /*DiagID=*/0);

bool IsMemberSpecialization = false;
bool IsVariableTemplateSpecialization = false;
bool IsPartialSpecialization = false;
bool IsVariableTemplate = false;
VarDecl *NewVD = nullptr;
VarTemplateDecl *NewTemplate = nullptr;
TemplateParameterList *TemplateParams = nullptr;
if (!getLangOpts().CPlusPlus) {
  NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(), D.getIdentifierLoc(),
                          II, R, TInfo, SC);

  if (R->getContainedDeducedType())
    ParsingInitForAutoVars.insert(NewVD);

  if (D.isInvalidType())
    NewVD->setInvalidDecl();

  if (NewVD->getType().hasNonTrivialToPrimitiveDestructCUnion() &&
      NewVD->hasLocalStorage())
    checkNonTrivialCUnion(NewVD->getType(), NewVD->getLocation(),
                          NTCUC_AutoVar, NTCUK_Destruct);
} else {
  bool Invalid = false;

  if (DC->isRecord() && !CurContext->isRecord()) {
    // This is an out-of-line definition of a static data member.
    switch (SC) {
    case SC_None:
      break;
    case SC_Static:
      Diag(D.getDeclSpec().getStorageClassSpecLoc(),
           diag::err_static_out_of_line)
        << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
      break;
    case SC_Auto:
    case SC_Register:
    case SC_Extern:
      // [dcl.stc] p2: The auto or register specifiers shall be applied only
      // to names of variables declared in a block or to function parameters.
      // [dcl.stc] p6: The extern specifier cannot be used in the declaration
      // of class members

      Diag(D.getDeclSpec().getStorageClassSpecLoc(),
           diag::err_storage_class_for_static_member)
        << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
      break;
    case SC_PrivateExtern:
      llvm_unreachable("C storage class in c++!")__builtin_unreachable();
    }
  }

  if (SC == SC_Static && CurContext->isRecord()) {
    if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) {
      // Walk up the enclosing DeclContexts to check for any that are
      // incompatible with static data members.
      const DeclContext *FunctionOrMethod = nullptr;
      const CXXRecordDecl *AnonStruct = nullptr;
      for (DeclContext *Ctxt = DC; Ctxt; Ctxt = Ctxt->getParent()) {
        if (Ctxt->isFunctionOrMethod()) {
          FunctionOrMethod = Ctxt;
          break;
        }
        const CXXRecordDecl *ParentDecl = dyn_cast<CXXRecordDecl>(Ctxt);
        if (ParentDecl && !ParentDecl->getDeclName()) {
          AnonStruct = ParentDecl;
          break;
        }
      }
      if (FunctionOrMethod) {
        // C++ [class.static.data]p5: A local class shall not have static data
        // members.
        Diag(D.getIdentifierLoc(),
             diag::err_static_data_member_not_allowed_in_local_class)
          << Name << RD->getDeclName() << RD->getTagKind();
      } else if (AnonStruct) {
        // C++ [class.static.data]p4: Unnamed classes and classes contained
        // directly or indirectly within unnamed classes shall not contain
        // static data members.
        Diag(D.getIdentifierLoc(),
             diag::err_static_data_member_not_allowed_in_anon_struct)
          << Name << AnonStruct->getTagKind();
        Invalid = true;
      } else if (RD->isUnion()) {
        // C++98 [class.union]p1: If a union contains a static data member,
        // the program is ill-formed. C++11 drops this restriction.
        Diag(D.getIdentifierLoc(),
             getLangOpts().CPlusPlus11
               ? diag::warn_cxx98_compat_static_data_member_in_union
               : diag::ext_static_data_member_in_union) << Name;
      }
    }
  }

  // Match up the template parameter lists with the scope specifier, then
  // determine whether we have a template or a template specialization.
  bool InvalidScope = false;
  TemplateParams = MatchTemplateParametersToScopeSpecifier(
      D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
      D.getCXXScopeSpec(),
      D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
          ? D.getName().TemplateId
          : nullptr,
      TemplateParamLists,
      /*never a friend*/ false, IsMemberSpecialization, InvalidScope);
  Invalid |= InvalidScope;

  if (TemplateParams) {
    if (!TemplateParams->size() &&
        D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
      // There is an extraneous 'template<>' for this variable. Complain
      // about it, but allow the declaration of the variable.
      Diag(TemplateParams->getTemplateLoc(),
           diag::err_template_variable_noparams)
        << II
        << SourceRange(TemplateParams->getTemplateLoc(),
                       TemplateParams->getRAngleLoc());
      TemplateParams = nullptr;
    } else {
      // Check that we can declare a template here.
      if (CheckTemplateDeclScope(S, TemplateParams))
        return nullptr;

      if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
        // This is an explicit specialization or a partial specialization.
        IsVariableTemplateSpecialization = true;
        IsPartialSpecialization = TemplateParams->size() > 0;
      } else { // if (TemplateParams->size() > 0)
        // This is a template declaration.
        IsVariableTemplate = true;

        // Only C++1y supports variable templates (N3651).
        Diag(D.getIdentifierLoc(),
             getLangOpts().CPlusPlus14
                 ? diag::warn_cxx11_compat_variable_template
                 : diag::ext_variable_template);
      }
    }
  } else {
    // Check that we can declare a member specialization here.
    if (!TemplateParamLists.empty() && IsMemberSpecialization &&
        CheckTemplateDeclScope(S, TemplateParamLists.back()))
      return nullptr;
    assert((Invalid ||((void)0)
            D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) &&((void)0)
           "should have a 'template<>' for this decl")((void)0);
  }

  if (IsVariableTemplateSpecialization) {
    SourceLocation TemplateKWLoc =
        TemplateParamLists.size() > 0
            ? TemplateParamLists[0]->getTemplateLoc()
            : SourceLocation();
    DeclResult Res = ActOnVarTemplateSpecialization(
        S, D, TInfo, TemplateKWLoc, TemplateParams, SC,
        IsPartialSpecialization);
    if (Res.isInvalid())
      return nullptr;
    NewVD = cast<VarDecl>(Res.get());
    AddToScope = false;
  } else if (D.isDecompositionDeclarator()) {
    NewVD = DecompositionDecl::Create(Context, DC, D.getBeginLoc(),
                                      D.getIdentifierLoc(), R, TInfo, SC,
                                      Bindings);
  } else
    NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(),
                            D.getIdentifierLoc(), II, R, TInfo, SC);

  // If this is supposed to be a variable template, create it as such.
  if (IsVariableTemplate) {
    NewTemplate =
        VarTemplateDecl::Create(Context, DC, D.getIdentifierLoc(), Name,
                                TemplateParams, NewVD);
    NewVD->setDescribedVarTemplate(NewTemplate);
  }

  // If this decl has an auto type in need of deduction, make a note of the
  // Decl so we can diagnose uses of it in its own initializer.
  if (R->getContainedDeducedType())
    ParsingInitForAutoVars.insert(NewVD);

  if (D.isInvalidType() || Invalid) {
    NewVD->setInvalidDecl();
    if (NewTemplate)
      NewTemplate->setInvalidDecl();
  }

  SetNestedNameSpecifier(*this, NewVD, D);

  // If we have any template parameter lists that don't directly belong to
  // the variable (matching the scope specifier), store them.
  unsigned VDTemplateParamLists = TemplateParams ? 1 : 0;
  if (TemplateParamLists.size() > VDTemplateParamLists)
    NewVD->setTemplateParameterListsInfo(
        Context, TemplateParamLists.drop_back(VDTemplateParamLists));
}

if (D.getDeclSpec().isInlineSpecified()) {
  if (!getLangOpts().CPlusPlus) {
    Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
        << 0;
  } else if (CurContext->isFunctionOrMethod()) {
    // 'inline' is not allowed on block scope variable declaration.
    Diag(D.getDeclSpec().getInlineSpecLoc(),
         diag::err_inline_declaration_block_scope) << Name
      << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
  } else {
    Diag(D.getDeclSpec().getInlineSpecLoc(),
         getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_inline_variable
                                   : diag::ext_inline_variable);
    NewVD->setInlineSpecified();
  }
}

// Set the lexical context. If the declarator has a C++ scope specifier, the
// lexical context will be different from the semantic context.
NewVD->setLexicalDeclContext(CurContext);
if (NewTemplate)
  NewTemplate->setLexicalDeclContext(CurContext);

if (IsLocalExternDecl) {
  if (D.isDecompositionDeclarator())
    for (auto *B : Bindings)
      B->setLocalExternDecl();
  else
    NewVD->setLocalExternDecl();
}

bool EmitTLSUnsupportedError = false;
if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) {
  // C++11 [dcl.stc]p4:
  //   When thread_local is applied to a variable of block scope the
  //   storage-class-specifier static is implied if it does not appear
  //   explicitly.
  // Core issue: 'static' is not implied if the variable is declared
  //   'extern'.
  if (NewVD->hasLocalStorage() &&
      (SCSpec != DeclSpec::SCS_unspecified ||
       TSCS != DeclSpec::TSCS_thread_local ||
       !DC->isFunctionOrMethod()))
    Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
         diag::err_thread_non_global)
      << DeclSpec::getSpecifierName(TSCS);
  else if (!Context.getTargetInfo().isTLSSupported()) {
    if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice ||
        getLangOpts().SYCLIsDevice) {
      // Postpone error emission until we've collected attributes required to
      // figure out whether it's a host or device variable and whether the
      // error should be ignored.
      EmitTLSUnsupportedError = true;
      // We still need to mark the variable as TLS so it shows up in AST with
      // proper storage class for other tools to use even if we're not going
      // to emit any code for it.
      NewVD->setTSCSpec(TSCS);
    } else
      Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
           diag::err_thread_unsupported);
  } else
    NewVD->setTSCSpec(TSCS);
}

switch (D.getDeclSpec().getConstexprSpecifier()) {
case ConstexprSpecKind::Unspecified:
  break;

case ConstexprSpecKind::Consteval:
  Diag(D.getDeclSpec().getConstexprSpecLoc(),
       diag::err_constexpr_wrong_decl_kind)
      << static_cast<int>(D.getDeclSpec().getConstexprSpecifier());
  LLVM_FALLTHROUGH[[gnu::fallthrough]];

case ConstexprSpecKind::Constexpr:
  NewVD->setConstexpr(true);
  // C++1z [dcl.spec.constexpr]p1:
  //   A static data member declared with the constexpr specifier is
  //   implicitly an inline variable.
  if (NewVD->isStaticDataMember() &&
      (getLangOpts().CPlusPlus17 ||
       Context.getTargetInfo().getCXXABI().isMicrosoft()))
    NewVD->setImplicitlyInline();
  break;

case ConstexprSpecKind::Constinit:
  if (!NewVD->hasGlobalStorage())
    Diag(D.getDeclSpec().getConstexprSpecLoc(),
         diag::err_constinit_local_variable);
  else
    NewVD->addAttr(ConstInitAttr::Create(
        Context, D.getDeclSpec().getConstexprSpecLoc(),
        AttributeCommonInfo::AS_Keyword, ConstInitAttr::Keyword_constinit));
  break;
}

// C99 6.7.4p3
//   An inline definition of a function with external linkage shall
//   not contain a definition of a modifiable object with static or
//   thread storage duration...
// We only apply this when the function is required to be defined
// elsewhere, i.e. when the function is not 'extern inline'.  Note
// that a local variable with thread storage duration still has to
// be marked 'static'.  Also note that it's possible to get these
// semantics in C++ using __attribute__((gnu_inline)).
if (SC == SC_Static && S->getFnParent() != nullptr &&
    !NewVD->getType().isConstQualified()) {
  FunctionDecl *CurFD = getCurFunctionDecl();
  if (CurFD && isFunctionDefinitionDiscarded(*this, CurFD)) {
    Diag(D.getDeclSpec().getStorageClassSpecLoc(),
         diag::warn_static_local_in_extern_inline);
    MaybeSuggestAddingStaticToDecl(CurFD);
  }
}

if (D.getDeclSpec().isModulePrivateSpecified()) {
  if (IsVariableTemplateSpecialization)
    Diag(NewVD->getLocation(), diag::err_module_private_specialization)
        << (IsPartialSpecialization ? 1 : 0)
        << FixItHint::CreateRemoval(
               D.getDeclSpec().getModulePrivateSpecLoc());
  else if (IsMemberSpecialization)
    Diag(NewVD->getLocation(), diag::err_module_private_specialization)
      << 2
      << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
  else if (NewVD->hasLocalStorage())
    Diag(NewVD->getLocation(), diag::err_module_private_local)
        << 0 << NewVD
        << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
        << FixItHint::CreateRemoval(
               D.getDeclSpec().getModulePrivateSpecLoc());
  else {
    NewVD->setModulePrivate();
    if (NewTemplate)
      NewTemplate->setModulePrivate();
    for (auto *B : Bindings)
      B->setModulePrivate();
  }
}

if (getLangOpts().OpenCL) {
  deduceOpenCLAddressSpace(NewVD);

  DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec();
  if (TSC != TSCS_unspecified) {
    bool IsCXX = getLangOpts().OpenCLCPlusPlus;
    Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
         diag::err_opencl_unknown_type_specifier)
        << IsCXX << getLangOpts().getOpenCLVersionTuple().getAsString()
        << DeclSpec::getSpecifierName(TSC) << 1;
    NewVD->setInvalidDecl();
  }
}

// Handle attributes prior to checking for duplicates in MergeVarDecl
ProcessDeclAttributes(S, NewVD, D);

// FIXME: This is probably the wrong location to be doing this and we should
// probably be doing this for more attributes (especially for function
// pointer attributes such as format, warn_unused_result, etc.). Ideally
// the code to copy attributes would be generated by TableGen.
if (R->isFunctionPointerType())
  if (const auto *TT = R->getAs<TypedefType>())
    copyAttrFromTypedefToDecl<AllocSizeAttr>(*this, NewVD, TT);

if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice ||
    getLangOpts().SYCLIsDevice) {
  if (EmitTLSUnsupportedError &&
      ((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) ||
       (getLangOpts().OpenMPIsDevice &&
        OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(NewVD))))
    Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
         diag::err_thread_unsupported);

  if (EmitTLSUnsupportedError &&
      (LangOpts.SYCLIsDevice || (LangOpts.OpenMP && LangOpts.OpenMPIsDevice)))
    targetDiag(D.getIdentifierLoc(), diag::err_thread_unsupported);
  // CUDA B.2.5: "__shared__ and __constant__ variables have implied static
  // storage [duration]."
  if (SC == SC_None && S->getFnParent() != nullptr &&
      (NewVD->hasAttr<CUDASharedAttr>() ||
       NewVD->hasAttr<CUDAConstantAttr>())) {
    NewVD->setStorageClass(SC_Static);
  }
}

// Ensure that dllimport globals without explicit storage class are treated as
// extern. The storage class is set above using parsed attributes. Now we can
// check the VarDecl itself.
assert(!NewVD->hasAttr<DLLImportAttr>() ||((void)0)
       NewVD->getAttr<DLLImportAttr>()->isInherited() ||((void)0)
       NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None)((void)0);

// In auto-retain/release, infer strong retension for variables of
// retainable type.
if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewVD))
  NewVD->setInvalidDecl();

// Handle GNU asm-label extension (encoded as an attribute).
if (Expr *E = (Expr*)D.getAsmLabel()) {
  // The parser guarantees this is a string.
  StringLiteral *SE = cast<StringLiteral>(E);
  StringRef Label = SE->getString();
  if (S->getFnParent() != nullptr) {
    switch (SC) {
    case SC_None:
    case SC_Auto:
      Diag(E->getExprLoc(), diag::warn_asm_label_on_auto_decl) << Label;
      break;
    case SC_Register:
      // Local Named register
      if (!Context.getTargetInfo().isValidGCCRegisterName(Label) &&
          DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl()))
        Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
      break;
    case SC_Static:
    case SC_Extern:
    case SC_PrivateExtern:
      break;
    }
  } else if (SC == SC_Register) {
    // Global Named register
    if (DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) {
      const auto &TI = Context.getTargetInfo();
      bool HasSizeMismatch;

      if (!TI.isValidGCCRegisterName(Label))
        Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
      else if (!TI.validateGlobalRegisterVariable(Label,
                                                  Context.getTypeSize(R),
                                                  HasSizeMismatch))
        Diag(E->getExprLoc(), diag::err_asm_invalid_global_var_reg) << Label;
      else if (HasSizeMismatch)
        Diag(E->getExprLoc(), diag::err_asm_register_size_mismatch) << Label;
    }

    if (!R->isIntegralType(Context) && !R->isPointerType()) {
      Diag(D.getBeginLoc(), diag::err_asm_bad_register_type);
      NewVD->setInvalidDecl(true);
    }
  }

  NewVD->addAttr(AsmLabelAttr::Create(Context, Label,
                                      /*IsLiteralLabel=*/true,
                                      SE->getStrTokenLoc(0)));
} else if (!ExtnameUndeclaredIdentifiers.empty()) {
  llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
    ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
  if (I != ExtnameUndeclaredIdentifiers.end()) {
    if (isDeclExternC(NewVD)) {
      NewVD->addAttr(I->second);
      ExtnameUndeclaredIdentifiers.erase(I);
    } else
      Diag(NewVD->getLocation(), diag::warn_redefine_extname_not_applied)
          << /*Variable*/1 << NewVD;
  }
}

// Find the shadowed declaration before filtering for scope.
NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
                              ? getShadowedDeclaration(NewVD, Previous)
                              : nullptr;

// Don't consider existing declarations that are in a different
// scope and are out-of-semantic-context declarations (if the new
// declaration has linkage).
FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewVD),
                     D.getCXXScopeSpec().isNotEmpty() ||
                     IsMemberSpecialization ||
                     IsVariableTemplateSpecialization);

// Check whether the previous declaration is in the same block scope. This
// affects whether we merge types with it, per C++11 [dcl.array]p3.
if (getLangOpts().CPlusPlus &&
    NewVD->isLocalVarDecl() && NewVD->hasExternalStorage())
  NewVD->setPreviousDeclInSameBlockScope(
      Previous.isSingleResult() && !Previous.isShadowed() &&
      isDeclInScope(Previous.getFoundDecl(), OriginalDC, S, false));

if (!getLangOpts().CPlusPlus) {
  D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
} else {
  // If this is an explicit specialization of a static data member, check it.
  if (IsMemberSpecialization && !NewVD->isInvalidDecl() &&
      CheckMemberSpecialization(NewVD, Previous))
    NewVD->setInvalidDecl();

  // Merge the decl with the existing one if appropriate.
  if (!Previous.empty()) {
    if (Previous.isSingleResult() &&
        isa<FieldDecl>(Previous.getFoundDecl()) &&
        D.getCXXScopeSpec().isSet()) {
      // The user tried to define a non-static data member
      // out-of-line (C++ [dcl.meaning]p1).
      Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line)
        << D.getCXXScopeSpec().getRange();
      Previous.clear();
      NewVD->setInvalidDecl();
    }
  } else if (D.getCXXScopeSpec().isSet()) {
    // No previous declaration in the qualifying scope.
    Diag(D.getIdentifierLoc(), diag::err_no_member)
      << Name << computeDeclContext(D.getCXXScopeSpec(), true)
      << D.getCXXScopeSpec().getRange();
    NewVD->setInvalidDecl();
  }

  if (!IsVariableTemplateSpecialization)
    D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));

  if (NewTemplate) {
    VarTemplateDecl *PrevVarTemplate =
        NewVD->getPreviousDecl()
            ? NewVD->getPreviousDecl()->getDescribedVarTemplate()
            : nullptr;

    // Check the template parameter list of this declaration, possibly
    // merging in the template parameter list from the previous variable
    // template declaration.
    if (CheckTemplateParameterList(
            TemplateParams,
            PrevVarTemplate ? PrevVarTemplate->getTemplateParameters()
                            : nullptr,
            (D.getCXXScopeSpec().isSet() && DC && DC->isRecord() &&
             DC->isDependentContext())
                ? TPC_ClassTemplateMember
                : TPC_VarTemplate))
      NewVD->setInvalidDecl();

    // If we are providing an explicit specialization of a static variable
    // template, make a note of that.
    if (PrevVarTemplate &&
        PrevVarTemplate->getInstantiatedFromMemberTemplate())
      PrevVarTemplate->setMemberSpecialization();
  }
}

// Diagnose shadowed variables iff this isn't a redeclaration.
if (ShadowedDecl && !D.isRedeclaration())
  CheckShadow(NewVD, ShadowedDecl, Previous);

ProcessPragmaWeak(S, NewVD);

// If this is the first declaration of an extern C variable, update
// the map of such variables.
if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() &&
    isIncompleteDeclExternC(*this, NewVD))
  RegisterLocallyScopedExternCDecl(NewVD, S);

if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
  MangleNumberingContext *MCtx;
  Decl *ManglingContextDecl;
  std::tie(MCtx, ManglingContextDecl) =
      getCurrentMangleNumberContext(NewVD->getDeclContext());
  if (MCtx) {
    Context.setManglingNumber(
        NewVD, MCtx->getManglingNumber(
                   NewVD, getMSManglingNumber(getLangOpts(), S)));
    Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
  }
}

// Special handling of variable named 'main'.
if (Name.getAsIdentifierInfo() && Name.getAsIdentifierInfo()->isStr("main") &&
    NewVD->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
    !getLangOpts().Freestanding && !NewVD->getDescribedVarTemplate()) {

  // C++ [basic.start.main]p3
  // A program that declares a variable main at global scope is ill-formed.
  if (getLangOpts().CPlusPlus)
    Diag(D.getBeginLoc(), diag::err_main_global_variable);

  // In C, and external-linkage variable named main results in undefined
  // behavior.
  else if (NewVD->hasExternalFormalLinkage())
    Diag(D.getBeginLoc(), diag::warn_main_redefined);
}

if (D.isRedeclaration() && !Previous.empty()) {
  NamedDecl *Prev = Previous.getRepresentativeDecl();
  checkDLLAttributeRedeclaration(*this, Prev, NewVD, IsMemberSpecialization,
                                 D.isFunctionDefinition());
}

if (NewTemplate) {
  if (NewVD->isInvalidDecl())
    NewTemplate->setInvalidDecl();
  ActOnDocumentableDecl(NewTemplate);
  return NewTemplate;
}

if (IsMemberSpecialization && !NewVD->isInvalidDecl())
  CompleteMemberSpecialization(NewVD, Previous);

return NewVD;
7580}

7582/// Enum describing the %select options in diag::warn_decl_shadow.
7583enum ShadowedDeclKind {
SDK_Local,
SDK_Global,
SDK_StaticMember,
SDK_Field,
SDK_Typedef,
SDK_Using,
SDK_StructuredBinding
7591};

7593/// Determine what kind of declaration we're shadowing.
7594static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
                                              const DeclContext *OldDC) {
if (isa<TypeAliasDecl>(ShadowedDecl))
  return SDK_Using;
else if (isa<TypedefDecl>(ShadowedDecl))
  return SDK_Typedef;
else if (isa<BindingDecl>(ShadowedDecl))
  return SDK_StructuredBinding;
else if (isa<RecordDecl>(OldDC))
  return isa<FieldDecl>(ShadowedDecl) ? SDK_Field : SDK_StaticMember;

return OldDC->isFileContext() ? SDK_Global : SDK_Local;
7606}

7608/// Return the location of the capture if the given lambda captures the given
7609/// variable \p VD, or an invalid source location otherwise.
7610static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI,
                                       const VarDecl *VD) {
for (const Capture &Capture : LSI->Captures) {
  if (Capture.isVariableCapture() && Capture.getVariable() == VD)
    return Capture.getLocation();
}
return SourceLocation();
7617}

7619static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
                                   const LookupResult &R) {
// Only diagnose if we're shadowing an unambiguous field or variable.
if (R.getResultKind() != LookupResult::Found)
  return false;

// Return false if warning is ignored.
return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc());
7627}

7629/// Return the declaration shadowed by the given variable \p D, or null
7630/// if it doesn't shadow any declaration or shadowing warnings are disabled.
7631NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
                                      const LookupResult &R) {
if (!shouldWarnIfShadowedDecl(Diags, R))
  return nullptr;

// Don't diagnose declarations at file scope.
if (D->hasGlobalStorage())
  return nullptr;

NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<VarDecl, FieldDecl, BindingDecl>(ShadowedDecl) ? ShadowedDecl
                                                          : nullptr;
7643}

7645/// Return the declaration shadowed by the given typedef \p D, or null
7646/// if it doesn't shadow any declaration or shadowing warnings are disabled.
7647NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
                                      const LookupResult &R) {
// Don't warn if typedef declaration is part of a class
if (D->getDeclContext()->isRecord())
  return nullptr;

if (!shouldWarnIfShadowedDecl(Diags, R))
  return nullptr;

NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<TypedefNameDecl>(ShadowedDecl) ? ShadowedDecl : nullptr;
7658}

7660/// Return the declaration shadowed by the given variable \p D, or null
7661/// if it doesn't shadow any declaration or shadowing warnings are disabled.
7662NamedDecl *Sema::getShadowedDeclaration(const BindingDecl *D,
                                      const LookupResult &R) {
if (!shouldWarnIfShadowedDecl(Diags, R))
  return nullptr;

NamedDecl *ShadowedDecl = R.getFoundDecl();
return isa<VarDecl, FieldDecl, BindingDecl>(ShadowedDecl) ? ShadowedDecl
                                                          : nullptr;
7670}

7672/// Diagnose variable or built-in function shadowing.  Implements
7673/// -Wshadow.
7674///
7675/// This method is called whenever a VarDecl is added to a "useful"
7676/// scope.
7677///
7678/// \param ShadowedDecl the declaration that is shadowed by the given variable
7679/// \param R the lookup of the name
7680///
7681void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
                     const LookupResult &R) {
DeclContext *NewDC = D->getDeclContext();

if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) {
  // Fields are not shadowed by variables in C++ static methods.
  if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDC))
    if (MD->isStatic())
      return;

  // Fields shadowed by constructor parameters are a special case. Usually
  // the constructor initializes the field with the parameter.
  if (isa<CXXConstructorDecl>(NewDC))
    if (const auto PVD = dyn_cast<ParmVarDecl>(D)) {
      // Remember that this was shadowed so we can either warn about its
      // modification or its existence depending on warning settings.
      ShadowingDecls.insert({PVD->getCanonicalDecl(), FD});
      return;
    }
}

if (VarDecl *shadowedVar = dyn_cast<VarDecl>(ShadowedDecl))
  if (shadowedVar->isExternC()) {
    // For shadowing external vars, make sure that we point to the global
    // declaration, not a locally scoped extern declaration.
    for (auto I : shadowedVar->redecls())
      if (I->isFileVarDecl()) {
        ShadowedDecl = I;
        break;
      }
  }

DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();

unsigned WarningDiag = diag::warn_decl_shadow;
SourceLocation CaptureLoc;
if (isa<VarDecl>(D) && isa<VarDecl>(ShadowedDecl) && NewDC &&
    isa<CXXMethodDecl>(NewDC)) {
  if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
    if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
      if (RD->getLambdaCaptureDefault() == LCD_None) {
        // Try to avoid warnings for lambdas with an explicit capture list.
        const auto *LSI = cast<LambdaScopeInfo>(getCurFunction());
        // Warn only when the lambda captures the shadowed decl explicitly.
        CaptureLoc = getCaptureLocation(LSI, cast<VarDecl>(ShadowedDecl));
        if (CaptureLoc.isInvalid())
          WarningDiag = diag::warn_decl_shadow_uncaptured_local;
      } else {
        // Remember that this was shadowed so we can avoid the warning if the
        // shadowed decl isn't captured and the warning settings allow it.
        cast<LambdaScopeInfo>(getCurFunction())
            ->ShadowingDecls.push_back(
                {cast<VarDecl>(D), cast<VarDecl>(ShadowedDecl)});
        return;
      }
    }

    if (cast<VarDecl>(ShadowedDecl)->hasLocalStorage()) {
      // A variable can't shadow a local variable in an enclosing scope, if
      // they are separated by a non-capturing declaration context.
      for (DeclContext *ParentDC = NewDC;
           ParentDC && !ParentDC->Equals(OldDC);
           ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) {
        // Only block literals, captured statements, and lambda expressions
        // can capture; other scopes don't.
        if (!isa<BlockDecl>(ParentDC) && !isa<CapturedDecl>(ParentDC) &&
            !isLambdaCallOperator(ParentDC)) {
          return;
        }
      }
    }
  }
}

// Only warn about certain kinds of shadowing for class members.
if (NewDC && NewDC->isRecord()) {
  // In particular, don't warn about shadowing non-class members.
  if (!OldDC->isRecord())
    return;

  // TODO: should we warn about static data members shadowing
  // static data members from base classes?

  // TODO: don't diagnose for inaccessible shadowed members.
  // This is hard to do perfectly because we might friend the
  // shadowing context, but that's just a false negative.
}


DeclarationName Name = R.getLookupName();

// Emit warning and note.
if (getSourceManager().isInSystemMacro(R.getNameLoc()))
  return;
ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC);
Diag(R.getNameLoc(), WarningDiag) << Name << Kind << OldDC;
if (!CaptureLoc.isInvalid())
  Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
      << Name << /*explicitly*/ 1;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7781}

7783/// Diagnose shadowing for variables shadowed in the lambda record \p LambdaRD
7784/// when these variables are captured by the lambda.
7785void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) {
for (const auto &Shadow : LSI->ShadowingDecls) {
  const VarDecl *ShadowedDecl = Shadow.ShadowedDecl;
  // Try to avoid the warning when the shadowed decl isn't captured.
  SourceLocation CaptureLoc = getCaptureLocation(LSI, ShadowedDecl);
  const DeclContext *OldDC = ShadowedDecl->getDeclContext();
  Diag(Shadow.VD->getLocation(), CaptureLoc.isInvalid()
                                     ? diag::warn_decl_shadow_uncaptured_local
                                     : diag::warn_decl_shadow)
      << Shadow.VD->getDeclName()
      << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
  if (!CaptureLoc.isInvalid())
    Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
        << Shadow.VD->getDeclName() << /*explicitly*/ 0;
  Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
}
7801}

7803/// Check -Wshadow without the advantage of a previous lookup.
7804void Sema::CheckShadow(Scope *S, VarDecl *D) {
if (Diags.isIgnored(diag::warn_decl_shadow, D->getLocation()))
  return;

LookupResult R(*this, D->getDeclName(), D->getLocation(),
               Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
LookupName(R, S);
if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R))
  CheckShadow(D, ShadowedDecl, R);
7813}

7815/// Check if 'E', which is an expression that is about to be modified, refers
7816/// to a constructor parameter that shadows a field.
7817void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) {
// Quickly ignore expressions that can't be shadowing ctor parameters.
if (!getLangOpts().CPlusPlus || ShadowingDecls.empty())
  return;
E = E->IgnoreParenImpCasts();
auto *DRE = dyn_cast<DeclRefExpr>(E);
if (!DRE)
  return;
const NamedDecl *D = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
auto I = ShadowingDecls.find(D);
if (I == ShadowingDecls.end())
  return;
const NamedDecl *ShadowedDecl = I->second;
const DeclContext *OldDC = ShadowedDecl->getDeclContext();
Diag(Loc, diag::warn_modifying_shadowing_decl) << D << OldDC;
Diag(D->getLocation(), diag::note_var_declared_here) << D;
Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);

// Avoid issuing multiple warnings about the same decl.
ShadowingDecls.erase(I);
7837}

7839/// Check for conflict between this global or extern "C" declaration and
7840/// previous global or extern "C" declarations. This is only used in C++.
7841template<typename T>
7842static bool checkGlobalOrExternCConflict(
  Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) {
assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\"")((void)0);
NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName());

if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) {
  // The common case: this global doesn't conflict with any extern "C"
  // declaration.
  return false;
}

if (Prev) {
  if (!IsGlobal || isIncompleteDeclExternC(S, ND)) {
    // Both the old and new declarations have C language linkage. This is a
    // redeclaration.
    Previous.clear();
    Previous.addDecl(Prev);
    return true;
  }

  // This is a global, non-extern "C" declaration, and there is a previous
  // non-global extern "C" declaration. Diagnose if this is a variable
  // declaration.
  if (!isa<VarDecl>(ND))
    return false;
} else {
  // The declaration is extern "C". Check for any declaration in the
  // translation unit which might conflict.
  if (IsGlobal) {
    // We have already performed the lookup into the translation unit.
    IsGlobal = false;
    for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
         I != E; ++I) {
      if (isa<VarDecl>(*I)) {
        Prev = *I;
        break;
      }
    }
  } else {
    DeclContext::lookup_result R =
        S.Context.getTranslationUnitDecl()->lookup(ND->getDeclName());
    for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end();
         I != E; ++I) {
      if (isa<VarDecl>(*I)) {
        Prev = *I;
        break;
      }
      // FIXME: If we have any other entity with this name in global scope,
      // the declaration is ill-formed, but that is a defect: it breaks the
      // 'stat' hack, for instance. Only variables can have mangled name
      // clashes with extern "C" declarations, so only they deserve a
      // diagnostic.
    }
  }

  if (!Prev)
    return false;
}

// Use the first declaration's location to ensure we point at something which
// is lexically inside an extern "C" linkage-spec.
assert(Prev && "should have found a previous declaration to diagnose")((void)0);
if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Prev))
  Prev = FD->getFirstDecl();
else
  Prev = cast<VarDecl>(Prev)->getFirstDecl();

S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict)
  << IsGlobal << ND;
S.Diag(Prev->getLocation(), diag::note_extern_c_global_conflict)
  << IsGlobal;
return false;
7914}

7916/// Apply special rules for handling extern "C" declarations. Returns \c true
7917/// if we have found that this is a redeclaration of some prior entity.
7918///
7919/// Per C++ [dcl.link]p6:
7920///   Two declarations [for a function or variable] with C language linkage
7921///   with the same name that appear in different scopes refer to the same
7922///   [entity]. An entity with C language linkage shall not be declared with
7923///   the same name as an entity in global scope.
7924template<typename T>
7925static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND,
                                                LookupResult &Previous) {
if (!S.getLangOpts().CPlusPlus) {
  // In C, when declaring a global variable, look for a corresponding 'extern'
  // variable declared in function scope. We don't need this in C++, because
  // we find local extern decls in the surrounding file-scope DeclContext.
  if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
    if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName())) {
      Previous.clear();
      Previous.addDecl(Prev);
      return true;
    }
  }
  return false;
}

// A declaration in the translation unit can conflict with an extern "C"
// declaration.
if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit())
  return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous);

// An extern "C" declaration can conflict with a declaration in the
// translation unit or can be a redeclaration of an extern "C" declaration
// in another scope.
if (isIncompleteDeclExternC(S,ND))
  return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous);

// Neither global nor extern "C": nothing to do.
return false;
7954}

7956void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
// If the decl is already known invalid, don't check it.
if (NewVD->isInvalidDecl())
  return;

QualType T = NewVD->getType();

// Defer checking an 'auto' type until its initializer is attached.
if (T->isUndeducedType())
  return;

if (NewVD->hasAttrs())
  CheckAlignasUnderalignment(NewVD);

if (T->isObjCObjectType()) {
  Diag(NewVD->getLocation(), diag::err_statically_allocated_object)
    << FixItHint::CreateInsertion(NewVD->getLocation(), "*");
  T = Context.getObjCObjectPointerType(T);
  NewVD->setType(T);
}

// Emit an error if an address space was applied to decl with local storage.
// This includes arrays of objects with address space qualifiers, but not
// automatic variables that point to other address spaces.
// ISO/IEC TR 18037 S5.1.2
if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() &&
    T.getAddressSpace() != LangAS::Default) {
  Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 0;
  NewVD->setInvalidDecl();
  return;
}

// OpenCL v1.2 s6.8 - The static qualifier is valid only in program
// scope.
if (getLangOpts().OpenCLVersion == 120 &&
    !getOpenCLOptions().isAvailableOption("cl_clang_storage_class_specifiers",
                                          getLangOpts()) &&
    NewVD->isStaticLocal()) {
  Diag(NewVD->getLocation(), diag::err_static_function_scope);
  NewVD->setInvalidDecl();
  return;
}

if (getLangOpts().OpenCL) {
  if (!diagnoseOpenCLTypes(*this, NewVD))
    return;

  // OpenCL v2.0 s6.12.5 - The __block storage type is not supported.
  if (NewVD->hasAttr<BlocksAttr>()) {
    Diag(NewVD->getLocation(), diag::err_opencl_block_storage_type);
    return;
  }

  if (T->isBlockPointerType()) {
    // OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and
    // can't use 'extern' storage class.
    if (!T.isConstQualified()) {
      Diag(NewVD->getLocation(), diag::err_opencl_invalid_block_declaration)
          << 0 /*const*/;
      NewVD->setInvalidDecl();
      return;
    }
    if (NewVD->hasExternalStorage()) {
      Diag(NewVD->getLocation(), diag::err_opencl_extern_block_declaration);
      NewVD->setInvalidDecl();
      return;
    }
  }

  // FIXME: Adding local AS in C++ for OpenCL might make sense.
  if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() ||
      NewVD->hasExternalStorage()) {
    if (!T->isSamplerT() && !T->isDependentType() &&
        !(T.getAddressSpace() == LangAS::opencl_constant ||
          (T.getAddressSpace() == LangAS::opencl_global &&
           getOpenCLOptions().areProgramScopeVariablesSupported(
               getLangOpts())))) {
      int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1;
      if (getOpenCLOptions().areProgramScopeVariablesSupported(getLangOpts()))
        Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
            << Scope << "global or constant";
      else
        Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
            << Scope << "constant";
      NewVD->setInvalidDecl();
      return;
    }
  } else {
    if (T.getAddressSpace() == LangAS::opencl_global) {
      Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
          << 1 /*is any function*/ << "global";
      NewVD->setInvalidDecl();
      return;
    }
    if (T.getAddressSpace() == LangAS::opencl_constant ||
        T.getAddressSpace() == LangAS::opencl_local) {
      FunctionDecl *FD = getCurFunctionDecl();
      // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
      // in functions.
      if (FD && !FD->hasAttr<OpenCLKernelAttr>()) {
        if (T.getAddressSpace() == LangAS::opencl_constant)
          Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
              << 0 /*non-kernel only*/ << "constant";
        else
          Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
              << 0 /*non-kernel only*/ << "local";
        NewVD->setInvalidDecl();
        return;
      }
      // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
      // in the outermost scope of a kernel function.
      if (FD && FD->hasAttr<OpenCLKernelAttr>()) {
        if (!getCurScope()->isFunctionScope()) {
          if (T.getAddressSpace() == LangAS::opencl_constant)
            Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
                << "constant";
          else
            Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
                << "local";
          NewVD->setInvalidDecl();
          return;
        }
      }
    } else if (T.getAddressSpace() != LangAS::opencl_private &&
               // If we are parsing a template we didn't deduce an addr
               // space yet.
               T.getAddressSpace() != LangAS::Default) {
      // Do not allow other address spaces on automatic variable.
      Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;
      NewVD->setInvalidDecl();
      return;
    }
  }
}

if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
    && !NewVD->hasAttr<BlocksAttr>()) {
  if (getLangOpts().getGC() != LangOptions::NonGC)
    Diag(NewVD->getLocation(), diag::warn_gc_attribute_weak_on_local);
  else {
    assert(!getLangOpts().ObjCAutoRefCount)((void)0);
    Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local);
  }
}

bool isVM = T->isVariablyModifiedType();
if (isVM || NewVD->hasAttr<CleanupAttr>() ||
    NewVD->hasAttr<BlocksAttr>())
  setFunctionHasBranchProtectedScope();

if ((isVM && NewVD->hasLinkage()) ||
    (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
  bool SizeIsNegative;
  llvm::APSInt Oversized;
  TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
      NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
  QualType FixedT;
  if (FixedTInfo &&  T == NewVD->getTypeSourceInfo()->getType())
    FixedT = FixedTInfo->getType();
  else if (FixedTInfo) {
    // Type and type-as-written are canonically different. We need to fix up
    // both types separately.
    FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
                                                 Oversized);
  }
  if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
    const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
    // FIXME: This won't give the correct result for
    // int a[10][n];
    SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();

    if (NewVD->isFileVarDecl())
      Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope)
      << SizeRange;
    else if (NewVD->isStaticLocal())
      Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage)
      << SizeRange;
    else
      Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
      << SizeRange;
    NewVD->setInvalidDecl();
    return;
  }

  if (!FixedTInfo) {
    if (NewVD->isFileVarDecl())
      Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope);
    else
      Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
    NewVD->setInvalidDecl();
    return;
  }

  Diag(NewVD->getLocation(), diag::ext_vla_folded_to_constant);
  NewVD->setType(FixedT);
  NewVD->setTypeSourceInfo(FixedTInfo);
}

if (T->isVoidType()) {
  // C++98 [dcl.stc]p5: The extern specifier can be applied only to the names
  //                    of objects and functions.
  if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) {
    Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
      << T;
    NewVD->setInvalidDecl();
    return;
  }
}

if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
  Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
  NewVD->setInvalidDecl();
  return;
}

if (!NewVD->hasLocalStorage() && T->isSizelessType()) {
  Diag(NewVD->getLocation(), diag::err_sizeless_nonlocal) << T;
  NewVD->setInvalidDecl();
  return;
}

if (isVM && NewVD->hasAttr<BlocksAttr>()) {
  Diag(NewVD->getLocation(), diag::err_block_on_vm);
  NewVD->setInvalidDecl();
  return;
}

if (NewVD->isConstexpr() && !T->isDependentType() &&
    RequireLiteralType(NewVD->getLocation(), T,
                       diag::err_constexpr_var_non_literal)) {
  NewVD->setInvalidDecl();
  return;
}

// PPC MMA non-pointer types are not allowed as non-local variable types.
if (Context.getTargetInfo().getTriple().isPPC64() &&
    !NewVD->isLocalVarDecl() &&
    CheckPPCMMAType(T, NewVD->getLocation())) {
  NewVD->setInvalidDecl();
  return;
}
8197}

8199/// Perform semantic checking on a newly-created variable
8200/// declaration.
8201///
8202/// This routine performs all of the type-checking required for a
8203/// variable declaration once it has been built. It is used both to
8204/// check variables after they have been parsed and their declarators
8205/// have been translated into a declaration, and to check variables
8206/// that have been instantiated from a template.
8207///
8208/// Sets NewVD->isInvalidDecl() if an error was encountered.
8209///
8210/// Returns true if the variable declaration is a redeclaration.
8211bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
CheckVariableDeclarationType(NewVD);

// If the decl is already known invalid, don't check it.
if (NewVD->isInvalidDecl())
  return false;

// If we did not find anything by this name, look for a non-visible
// extern "C" declaration with the same name.
if (Previous.empty() &&
    checkForConflictWithNonVisibleExternC(*this, NewVD, Previous))
  Previous.setShadowed();

if (!Previous.empty()) {
  MergeVarDecl(NewVD, Previous);
  return true;
}
return false;
8229}

8231/// AddOverriddenMethods - See if a method overrides any in the base classes,
8232/// and if so, check that it's a valid override and remember it.
8233bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
llvm::SmallPtrSet<const CXXMethodDecl*, 4> Overridden;

// Look for methods in base classes that this method might override.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
                   /*DetectVirtual=*/false);
auto VisitBase = [&] (const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
  CXXRecordDecl *BaseRecord = Specifier->getType()->getAsCXXRecordDecl();
  DeclarationName Name = MD->getDeclName();

  if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
    // We really want to find the base class destructor here.
    QualType T = Context.getTypeDeclType(BaseRecord);
    CanQualType CT = Context.getCanonicalType(T);
    Name = Context.DeclarationNames.getCXXDestructorName(CT);
  }

  for (NamedDecl *BaseND : BaseRecord->lookup(Name)) {
    CXXMethodDecl *BaseMD =
        dyn_cast<CXXMethodDecl>(BaseND->getCanonicalDecl());
    if (!BaseMD || !BaseMD->isVirtual() ||
        IsOverload(MD, BaseMD, /*UseMemberUsingDeclRules=*/false,
                   /*ConsiderCudaAttrs=*/true,
                   // C++2a [class.virtual]p2 does not consider requires
                   // clauses when overriding.
                   /*ConsiderRequiresClauses=*/false))
      continue;

    if (Overridden.insert(BaseMD).second) {
      MD->addOverriddenMethod(BaseMD);
      CheckOverridingFunctionReturnType(MD, BaseMD);
      CheckOverridingFunctionAttributes(MD, BaseMD);
      CheckOverridingFunctionExceptionSpec(MD, BaseMD);
      CheckIfOverriddenFunctionIsMarkedFinal(MD, BaseMD);
    }

    // A method can only override one function from each base class. We
    // don't track indirectly overridden methods from bases of bases.
    return true;
  }

  return false;
};

DC->lookupInBases(VisitBase, Paths);
return !Overridden.empty();
8279}

8281namespace {
// Struct for holding all of the extra arguments needed by
// DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator.
struct ActOnFDArgs {
  Scope *S;
  Declarator &D;
  MultiTemplateParamsArg TemplateParamLists;
  bool AddToScope;
};
8290} // end anonymous namespace

8292namespace {

8294// Callback to only accept typo corrections that have a non-zero edit distance.
8295// Also only accept corrections that have the same parent decl.
8296class DifferentNameValidatorCCC final : public CorrectionCandidateCallback {
public:
DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD,
                          CXXRecordDecl *Parent)
    : Context(Context), OriginalFD(TypoFD),
      ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  if (candidate.getEditDistance() == 0)
    return false;

  SmallVector<unsigned, 1> MismatchedParams;
  for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(),
                                        CDeclEnd = candidate.end();
       CDecl != CDeclEnd; ++CDecl) {
    FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);

    if (FD && !FD->hasBody() &&
        hasSimilarParameters(Context, FD, OriginalFD, MismatchedParams)) {
      if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
        CXXRecordDecl *Parent = MD->getParent();
        if (Parent && Parent->getCanonicalDecl() == ExpectedParent)
          return true;
      } else if (!ExpectedParent) {
        return true;
      }
    }
  }

  return false;
}

std::unique_ptr<CorrectionCandidateCallback> clone() override {
  return std::make_unique<DifferentNameValidatorCCC>(*this);
}

private:
ASTContext &Context;
FunctionDecl *OriginalFD;
CXXRecordDecl *ExpectedParent;
8336};

8338} // end anonymous namespace

8340void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) {
TypoCorrectedFunctionDefinitions.insert(F);
8342}

8344/// Generate diagnostics for an invalid function redeclaration.
8345///
8346/// This routine handles generating the diagnostic messages for an invalid
8347/// function redeclaration, including finding possible similar declarations
8348/// or performing typo correction if there are no previous declarations with
8349/// the same name.
8350///
8351/// Returns a NamedDecl iff typo correction was performed and substituting in
8352/// the new declaration name does not cause new errors.
8353static NamedDecl *DiagnoseInvalidRedeclaration(
  Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD,
  ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) {
DeclarationName Name = NewFD->getDeclName();
DeclContext *NewDC = NewFD->getDeclContext();
SmallVector<unsigned, 1> MismatchedParams;
SmallVector<std::pair<FunctionDecl *, unsigned>, 1> NearMatches;
TypoCorrection Correction;
bool IsDefinition = ExtraArgs.D.isFunctionDefinition();
unsigned DiagMsg =
  IsLocalFriend ? diag::err_no_matching_local_friend :
  NewFD->getFriendObjectKind() ? diag::err_qualified_friend_no_match :
  diag::err_member_decl_does_not_match;
LookupResult Prev(SemaRef, Name, NewFD->getLocation(),
                  IsLocalFriend ? Sema::LookupLocalFriendName
                                : Sema::LookupOrdinaryName,
                  Sema::ForVisibleRedeclaration);

NewFD->setInvalidDecl();
if (IsLocalFriend)
  SemaRef.LookupName(Prev, S);
else
  SemaRef.LookupQualifiedName(Prev, NewDC);
assert(!Prev.isAmbiguous() &&((void)0)
       "Cannot have an ambiguity in previous-declaration lookup")((void)0);
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
DifferentNameValidatorCCC CCC(SemaRef.Context, NewFD,
                              MD ? MD->getParent() : nullptr);
if (!Prev.empty()) {
  for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
       Func != FuncEnd; ++Func) {
    FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func);
    if (FD &&
        hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
      // Add 1 to the index so that 0 can mean the mismatch didn't
      // involve a parameter
      unsigned ParamNum =
          MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1;
      NearMatches.push_back(std::make_pair(FD, ParamNum));
    }
  }
// If the qualified name lookup yielded nothing, try typo correction
} else if ((Correction = SemaRef.CorrectTypo(
                Prev.getLookupNameInfo(), Prev.getLookupKind(), S,
                &ExtraArgs.D.getCXXScopeSpec(), CCC, Sema::CTK_ErrorRecovery,
                IsLocalFriend ? nullptr : NewDC))) {
  // Set up everything for the call to ActOnFunctionDeclarator
  ExtraArgs.D.SetIdentifier(Correction.getCorrectionAsIdentifierInfo(),
                            ExtraArgs.D.getIdentifierLoc());
  Previous.clear();
  Previous.setLookupName(Correction.getCorrection());
  for (TypoCorrection::decl_iterator CDecl = Correction.begin(),
                                  CDeclEnd = Correction.end();
       CDecl != CDeclEnd; ++CDecl) {
    FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
    if (FD && !FD->hasBody() &&
        hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
      Previous.addDecl(FD);
    }
  }
  bool wasRedeclaration = ExtraArgs.D.isRedeclaration();

  NamedDecl *Result;
  // Retry building the function declaration with the new previous
  // declarations, and with errors suppressed.
  {
    // Trap errors.
    Sema::SFINAETrap Trap(SemaRef);

    // TODO: Refactor ActOnFunctionDeclarator so that we can call only the
    // pieces need to verify the typo-corrected C++ declaration and hopefully
    // eliminate the need for the parameter pack ExtraArgs.
    Result = SemaRef.ActOnFunctionDeclarator(
        ExtraArgs.S, ExtraArgs.D,
        Correction.getCorrectionDecl()->getDeclContext(),
        NewFD->getTypeSourceInfo(), Previous, ExtraArgs.TemplateParamLists,
        ExtraArgs.AddToScope);

    if (Trap.hasErrorOccurred())
      Result = nullptr;
  }

  if (Result) {
    // Determine which correction we picked.
    Decl *Canonical = Result->getCanonicalDecl();
    for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
         I != E; ++I)
      if ((*I)->getCanonicalDecl() == Canonical)
        Correction.setCorrectionDecl(*I);

    // Let Sema know about the correction.
    SemaRef.MarkTypoCorrectedFunctionDefinition(Result);
    SemaRef.diagnoseTypo(
        Correction,
        SemaRef.PDiag(IsLocalFriend
                        ? diag::err_no_matching_local_friend_suggest
                        : diag::err_member_decl_does_not_match_suggest)
          << Name << NewDC << IsDefinition);
    return Result;
  }

  // Pretend the typo correction never occurred
  ExtraArgs.D.SetIdentifier(Name.getAsIdentifierInfo(),
                            ExtraArgs.D.getIdentifierLoc());
  ExtraArgs.D.setRedeclaration(wasRedeclaration);
  Previous.clear();
  Previous.setLookupName(Name);
}

SemaRef.Diag(NewFD->getLocation(), DiagMsg)
    << Name << NewDC << IsDefinition << NewFD->getLocation();

bool NewFDisConst = false;
if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD))
  NewFDisConst = NewMD->isConst();

for (SmallVectorImpl<std::pair<FunctionDecl *, unsigned> >::iterator
     NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end();
     NearMatch != NearMatchEnd; ++NearMatch) {
  FunctionDecl *FD = NearMatch->first;
  CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
  bool FDisConst = MD && MD->isConst();
  bool IsMember = MD || !IsLocalFriend;

  // FIXME: These notes are poorly worded for the local friend case.
  if (unsigned Idx = NearMatch->second) {
    ParmVarDecl *FDParam = FD->getParamDecl(Idx-1);
    SourceLocation Loc = FDParam->getTypeSpecStartLoc();
    if (Loc.isInvalid()) Loc = FD->getLocation();
    SemaRef.Diag(Loc, IsMember ? diag::note_member_def_close_param_match
                               : diag::note_local_decl_close_param_match)
      << Idx << FDParam->getType()
      << NewFD->getParamDecl(Idx - 1)->getType();
  } else if (FDisConst != NewFDisConst) {
    SemaRef.Diag(FD->getLocation(), diag::note_member_def_close_const_match)
        << NewFDisConst << FD->getSourceRange().getEnd();
  } else
    SemaRef.Diag(FD->getLocation(),
                 IsMember ? diag::note_member_def_close_match
                          : diag::note_local_decl_close_match);
}
return nullptr;
8495}

8497static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) {
switch (D.getDeclSpec().getStorageClassSpec()) {
11
←
Control jumps to 'case SCS_private_extern:'  at line 8526→
default: llvm_unreachable("Unknown storage class!")__builtin_unreachable();
case DeclSpec::SCS_auto:
case DeclSpec::SCS_register:
case DeclSpec::SCS_mutable:
  SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
               diag::err_typecheck_sclass_func);
  D.getMutableDeclSpec().ClearStorageClassSpecs();
  D.setInvalidType();
  break;
case DeclSpec::SCS_unspecified: break;
case DeclSpec::SCS_extern:
  if (D.getDeclSpec().isExternInLinkageSpec())
    return SC_None;
  return SC_Extern;
case DeclSpec::SCS_static: {
  if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) {
    // C99 6.7.1p5:
    //   The declaration of an identifier for a function that has
    //   block scope shall have no explicit storage-class specifier
    //   other than extern
    // See also (C++ [dcl.stc]p4).
    SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
                 diag::err_static_block_func);
    break;
  } else
    return SC_Static;
}
case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
12
←
Returning without writing to 'D.Redeclaration', which participates in a condition later→
}

// No explicit storage class has already been returned
return SC_None;
8531}

8533static FunctionDecl *CreateNewFunctionDecl(Sema &SemaRef, Declarator &D,
                                         DeclContext *DC, QualType &R,
                                         TypeSourceInfo *TInfo,
                                         StorageClass SC,
                                         bool &IsVirtualOkay) {
DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D);
18
←
Calling 'Sema::GetNameForDeclarator'→
20
←
Returning from 'Sema::GetNameForDeclarator'→
DeclarationName Name = NameInfo.getName();

FunctionDecl *NewFD = nullptr;
bool isInline = D.getDeclSpec().isInlineSpecified();

if (!SemaRef.getLangOpts().CPlusPlus) {
21
←
Assuming field 'CPlusPlus' is not equal to 0, which participates in a condition later→
22
←
Taking false branch→
  // Determine whether the function was written with a
  // prototype. This true when:
  //   - there is a prototype in the declarator, or
  //   - the type R of the function is some kind of typedef or other non-
  //     attributed reference to a type name (which eventually refers to a
  //     function type).
  bool HasPrototype =
    (D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
    (!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());

  NewFD = FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo,
                               R, TInfo, SC, isInline, HasPrototype,
                               ConstexprSpecKind::Unspecified,
                               /*TrailingRequiresClause=*/nullptr);
  if (D.isInvalidType())
    NewFD->setInvalidDecl();

  return NewFD;
}

ExplicitSpecifier ExplicitSpecifier = D.getDeclSpec().getExplicitSpecifier();

ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
if (ConstexprKind == ConstexprSpecKind::Constinit) {
23
←
Assuming 'ConstexprKind' is not equal to Constinit→
24
←
Taking false branch→
  SemaRef.Diag(D.getDeclSpec().getConstexprSpecLoc(),
               diag::err_constexpr_wrong_decl_kind)
      << static_cast<int>(ConstexprKind);
  ConstexprKind = ConstexprSpecKind::Unspecified;
  D.getMutableDeclSpec().ClearConstexprSpec();
}
Expr *TrailingRequiresClause = D.getTrailingRequiresClause();

// Check that the return type is not an abstract class type.
// For record types, this is done by the AbstractClassUsageDiagnoser once
// the class has been completely parsed.
if (!DC->isRecord() &&
26
←
Assuming the condition is false→
27
←
Taking false branch→
    SemaRef.RequireNonAbstractType(
        D.getIdentifierLoc(), R->castAs<FunctionType>()->getReturnType(),
25
←
The object is a 'FunctionType'→
        diag::err_abstract_type_in_decl, SemaRef.AbstractReturnType))
  D.setInvalidType();

if (Name.getNameKind() == DeclarationName::CXXConstructorName) {
28
←
Taking false branch→
  // This is a C++ constructor declaration.
  assert(DC->isRecord() &&((void)0)
         "Constructors can only be declared in a member context")((void)0);

  R = SemaRef.CheckConstructorDeclarator(D, R, SC);
  return CXXConstructorDecl::Create(
      SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
      TInfo, ExplicitSpecifier, isInline,
      /*isImplicitlyDeclared=*/false, ConstexprKind, InheritedConstructor(),
      TrailingRequiresClause);

} else if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
29
←
Taking false branch→
  // This is a C++ destructor declaration.
  if (DC->isRecord()) {
    R = SemaRef.CheckDestructorDeclarator(D, R, SC);
    CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
    CXXDestructorDecl *NewDD = CXXDestructorDecl::Create(
        SemaRef.Context, Record, D.getBeginLoc(), NameInfo, R, TInfo,
        isInline, /*isImplicitlyDeclared=*/false, ConstexprKind,
        TrailingRequiresClause);

    // If the destructor needs an implicit exception specification, set it
    // now. FIXME: It'd be nice to be able to create the right type to start
    // with, but the type needs to reference the destructor declaration.
    if (SemaRef.getLangOpts().CPlusPlus11)
      SemaRef.AdjustDestructorExceptionSpec(NewDD);

    IsVirtualOkay = true;
    return NewDD;

  } else {
    SemaRef.Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
    D.setInvalidType();

    // Create a FunctionDecl to satisfy the function definition parsing
    // code path.
    return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(),
                                D.getIdentifierLoc(), Name, R, TInfo, SC,
                                isInline,
                                /*hasPrototype=*/true, ConstexprKind,
                                TrailingRequiresClause);
  }

} else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
30
←
Taking false branch→
  if (!DC->isRecord()) {
    SemaRef.Diag(D.getIdentifierLoc(),
         diag::err_conv_function_not_member);
    return nullptr;
  }

  SemaRef.CheckConversionDeclarator(D, R, SC);
  if (D.isInvalidType())
    return nullptr;

  IsVirtualOkay = true;
  return CXXConversionDecl::Create(
      SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
      TInfo, isInline, ExplicitSpecifier, ConstexprKind, SourceLocation(),
      TrailingRequiresClause);

} else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
31
←
Assuming the condition is false→
32
←
Taking false branch→
  if (TrailingRequiresClause)
    SemaRef.Diag(TrailingRequiresClause->getBeginLoc(),
                 diag::err_trailing_requires_clause_on_deduction_guide)
        << TrailingRequiresClause->getSourceRange();
  SemaRef.CheckDeductionGuideDeclarator(D, R, SC);

  return CXXDeductionGuideDecl::Create(SemaRef.Context, DC, D.getBeginLoc(),
                                       ExplicitSpecifier, NameInfo, R, TInfo,
                                       D.getEndLoc());
} else if (DC->isRecord()) {
33
←
Calling 'DeclContext::isRecord'→
35
←
Returning from 'DeclContext::isRecord'→
36
←
Taking false branch→
  // If the name of the function is the same as the name of the record,
  // then this must be an invalid constructor that has a return type.
  // (The parser checks for a return type and makes the declarator a
  // constructor if it has no return type).
  if (Name.getAsIdentifierInfo() &&
      Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){
    SemaRef.Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
      << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
      << SourceRange(D.getIdentifierLoc());
    return nullptr;
  }

  // This is a C++ method declaration.
  CXXMethodDecl *Ret = CXXMethodDecl::Create(
      SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
      TInfo, SC, isInline, ConstexprKind, SourceLocation(),
      TrailingRequiresClause);
  IsVirtualOkay = !Ret->isStatic();
  return Ret;
} else {
  bool isFriend =
      SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified();
37
←
Assuming field 'CPlusPlus' is 0→
  if (!isFriend37.1
'isFriend' is false
1
'isFriend' is false
 && SemaRef.CurContext->isRecord())
38
←
Calling 'DeclContext::isRecord'→
41
←
Returning from 'DeclContext::isRecord'→
42
←
Taking false branch→
    return nullptr;

  // Determine whether the function was written with a
  // prototype. This true when:
  //   - we're in C++ (where every function has a prototype),
  return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo,
43
←
Returning without writing to 'D.Redeclaration', which participates in a condition later→
44
←
Returning pointer, which participates in a condition later→
                              R, TInfo, SC, isInline, true /*HasPrototype*/,
                              ConstexprKind, TrailingRequiresClause);
}
8690}

8692enum OpenCLParamType {
ValidKernelParam,
PtrPtrKernelParam,
PtrKernelParam,
InvalidAddrSpacePtrKernelParam,
InvalidKernelParam,
RecordKernelParam
8699};

8701static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) {
// Size dependent types are just typedefs to normal integer types
// (e.g. unsigned long), so we cannot distinguish them from other typedefs to
// integers other than by their names.
StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"};

// Remove typedefs one by one until we reach a typedef
// for a size dependent type.
QualType DesugaredTy = Ty;
do {
  ArrayRef<StringRef> Names(SizeTypeNames);
  auto Match = llvm::find(Names, DesugaredTy.getUnqualifiedType().getAsString());
  if (Names.end() != Match)
    return true;

  Ty = DesugaredTy;
  DesugaredTy = Ty.getSingleStepDesugaredType(C);
} while (DesugaredTy != Ty);

return false;
8721}

8723static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) {
if (PT->isDependentType())
  return InvalidKernelParam;

if (PT->isPointerType() || PT->isReferenceType()) {
  QualType PointeeType = PT->getPointeeType();
  if (PointeeType.getAddressSpace() == LangAS::opencl_generic ||
      PointeeType.getAddressSpace() == LangAS::opencl_private ||
      PointeeType.getAddressSpace() == LangAS::Default)
    return InvalidAddrSpacePtrKernelParam;

  if (PointeeType->isPointerType()) {
    // This is a pointer to pointer parameter.
    // Recursively check inner type.
    OpenCLParamType ParamKind = getOpenCLKernelParameterType(S, PointeeType);
    if (ParamKind == InvalidAddrSpacePtrKernelParam ||
        ParamKind == InvalidKernelParam)
      return ParamKind;

    return PtrPtrKernelParam;
  }

  // C++ for OpenCL v1.0 s2.4:
  // Moreover the types used in parameters of the kernel functions must be:
  // Standard layout types for pointer parameters. The same applies to
  // reference if an implementation supports them in kernel parameters.
  if (S.getLangOpts().OpenCLCPlusPlus &&
      !S.getOpenCLOptions().isAvailableOption(
          "__cl_clang_non_portable_kernel_param_types", S.getLangOpts()) &&
      !PointeeType->isAtomicType() && !PointeeType->isVoidType() &&
      !PointeeType->isStandardLayoutType())
    return InvalidKernelParam;

  return PtrKernelParam;
}

// OpenCL v1.2 s6.9.k:
// Arguments to kernel functions in a program cannot be declared with the
// built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
// uintptr_t or a struct and/or union that contain fields declared to be one
// of these built-in scalar types.
if (isOpenCLSizeDependentType(S.getASTContext(), PT))
  return InvalidKernelParam;

if (PT->isImageType())
  return PtrKernelParam;

if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT())
  return InvalidKernelParam;

// OpenCL extension spec v1.2 s9.5:
// This extension adds support for half scalar and vector types as built-in
// types that can be used for arithmetic operations, conversions etc.
if (!S.getOpenCLOptions().isAvailableOption("cl_khr_fp16", S.getLangOpts()) &&
    PT->isHalfType())
  return InvalidKernelParam;

// Look into an array argument to check if it has a forbidden type.
if (PT->isArrayType()) {
  const Type *UnderlyingTy = PT->getPointeeOrArrayElementType();
  // Call ourself to check an underlying type of an array. Since the
  // getPointeeOrArrayElementType returns an innermost type which is not an
  // array, this recursive call only happens once.
  return getOpenCLKernelParameterType(S, QualType(UnderlyingTy, 0));
}

// C++ for OpenCL v1.0 s2.4:
// Moreover the types used in parameters of the kernel functions must be:
// Trivial and standard-layout types C++17 [basic.types] (plain old data
// types) for parameters passed by value;
if (S.getLangOpts().OpenCLCPlusPlus &&
    !S.getOpenCLOptions().isAvailableOption(
        "__cl_clang_non_portable_kernel_param_types", S.getLangOpts()) &&
    !PT->isOpenCLSpecificType() && !PT.isPODType(S.Context))
  return InvalidKernelParam;

if (PT->isRecordType())
  return RecordKernelParam;

return ValidKernelParam;
8803}

8805static void checkIsValidOpenCLKernelParameter(
Sema &S,
Declarator &D,
ParmVarDecl *Param,
llvm::SmallPtrSetImpl<const Type *> &ValidTypes) {
QualType PT = Param->getType();

// Cache the valid types we encounter to avoid rechecking structs that are
// used again
if (ValidTypes.count(PT.getTypePtr()))
  return;

switch (getOpenCLKernelParameterType(S, PT)) {
case PtrPtrKernelParam:
  // OpenCL v3.0 s6.11.a:
  // A kernel function argument cannot be declared as a pointer to a pointer
  // type. [...] This restriction only applies to OpenCL C 1.2 or below.
  if (S.getLangOpts().OpenCLVersion <= 120 &&
      !S.getLangOpts().OpenCLCPlusPlus) {
    S.Diag(Param->getLocation(), diag::err_opencl_ptrptr_kernel_param);
    D.setInvalidType();
    return;
  }

  ValidTypes.insert(PT.getTypePtr());
  return;

case InvalidAddrSpacePtrKernelParam:
  // OpenCL v1.0 s6.5:
  // __kernel function arguments declared to be a pointer of a type can point
  // to one of the following address spaces only : __global, __local or
  // __constant.
  S.Diag(Param->getLocation(), diag::err_kernel_arg_address_space);
  D.setInvalidType();
  return;

  // OpenCL v1.2 s6.9.k:
  // Arguments to kernel functions in a program cannot be declared with the
  // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
  // uintptr_t or a struct and/or union that contain fields declared to be
  // one of these built-in scalar types.

case InvalidKernelParam:
  // OpenCL v1.2 s6.8 n:
  // A kernel function argument cannot be declared
  // of event_t type.
  // Do not diagnose half type since it is diagnosed as invalid argument
  // type for any function elsewhere.
  if (!PT->isHalfType()) {
    S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;

    // Explain what typedefs are involved.
    const TypedefType *Typedef = nullptr;
    while ((Typedef = PT->getAs<TypedefType>())) {
      SourceLocation Loc = Typedef->getDecl()->getLocation();
      // SourceLocation may be invalid for a built-in type.
      if (Loc.isValid())
        S.Diag(Loc, diag::note_entity_declared_at) << PT;
      PT = Typedef->desugar();
    }
  }

  D.setInvalidType();
  return;

case PtrKernelParam:
case ValidKernelParam:
  ValidTypes.insert(PT.getTypePtr());
  return;

case RecordKernelParam:
  break;
}

// Track nested structs we will inspect
SmallVector<const Decl *, 4> VisitStack;

// Track where we are in the nested structs. Items will migrate from
// VisitStack to HistoryStack as we do the DFS for bad field.
SmallVector<const FieldDecl *, 4> HistoryStack;
HistoryStack.push_back(nullptr);

// At this point we already handled everything except of a RecordType or
// an ArrayType of a RecordType.
assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type.")((void)0);
const RecordType *RecTy =
    PT->getPointeeOrArrayElementType()->getAs<RecordType>();
const RecordDecl *OrigRecDecl = RecTy->getDecl();

VisitStack.push_back(RecTy->getDecl());
assert(VisitStack.back() && "First decl null?")((void)0);

do {
  const Decl *Next = VisitStack.pop_back_val();
  if (!Next) {
    assert(!HistoryStack.empty())((void)0);
    // Found a marker, we have gone up a level
    if (const FieldDecl *Hist = HistoryStack.pop_back_val())
      ValidTypes.insert(Hist->getType().getTypePtr());

    continue;
  }

  // Adds everything except the original parameter declaration (which is not a
  // field itself) to the history stack.
  const RecordDecl *RD;
  if (const FieldDecl *Field = dyn_cast<FieldDecl>(Next)) {
    HistoryStack.push_back(Field);

    QualType FieldTy = Field->getType();
    // Other field types (known to be valid or invalid) are handled while we
    // walk around RecordDecl::fields().
    assert((FieldTy->isArrayType() || FieldTy->isRecordType()) &&((void)0)
           "Unexpected type.")((void)0);
    const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType();

    RD = FieldRecTy->castAs<RecordType>()->getDecl();
  } else {
    RD = cast<RecordDecl>(Next);
  }

  // Add a null marker so we know when we've gone back up a level
  VisitStack.push_back(nullptr);

  for (const auto *FD : RD->fields()) {
    QualType QT = FD->getType();

    if (ValidTypes.count(QT.getTypePtr()))
      continue;

    OpenCLParamType ParamType = getOpenCLKernelParameterType(S, QT);
    if (ParamType == ValidKernelParam)
      continue;

    if (ParamType == RecordKernelParam) {
      VisitStack.push_back(FD);
      continue;
    }

    // OpenCL v1.2 s6.9.p:
    // Arguments to kernel functions that are declared to be a struct or union
    // do not allow OpenCL objects to be passed as elements of the struct or
    // union.
    if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam ||
        ParamType == InvalidAddrSpacePtrKernelParam) {
      S.Diag(Param->getLocation(),
             diag::err_record_with_pointers_kernel_param)
        << PT->isUnionType()
        << PT;
    } else {
      S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
    }

    S.Diag(OrigRecDecl->getLocation(), diag::note_within_field_of_type)
        << OrigRecDecl->getDeclName();

    // We have an error, now let's go back up through history and show where
    // the offending field came from
    for (ArrayRef<const FieldDecl *>::const_iterator
             I = HistoryStack.begin() + 1,
             E = HistoryStack.end();
         I != E; ++I) {
      const FieldDecl *OuterField = *I;
      S.Diag(OuterField->getLocation(), diag::note_within_field_of_type)
        << OuterField->getType();
    }

    S.Diag(FD->getLocation(), diag::note_illegal_field_declared_here)
      << QT->isPointerType()
      << QT;
    D.setInvalidType();
    return;
  }
} while (!VisitStack.empty());
8979}

8981/// Find the DeclContext in which a tag is implicitly declared if we see an
8982/// elaborated type specifier in the specified context, and lookup finds
8983/// nothing.
8984static DeclContext *getTagInjectionContext(DeclContext *DC) {
while (!DC->isFileContext() && !DC->isFunctionOrMethod())
  DC = DC->getParent();
return DC;
8988}

8990/// Find the Scope in which a tag is implicitly declared if we see an
8991/// elaborated type specifier in the specified context, and lookup finds
8992/// nothing.
8993static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) {
while (S->isClassScope() ||
       (LangOpts.CPlusPlus &&
        S->isFunctionPrototypeScope()) ||
       ((S->getFlags() & Scope::DeclScope) == 0) ||
       (S->getEntity() && S->getEntity()->isTransparentContext()))
  S = S->getParent();
return S;
9001}

9003NamedDecl*
9004Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
                            TypeSourceInfo *TInfo, LookupResult &Previous,
                            MultiTemplateParamsArg TemplateParamListsRef,
                            bool &AddToScope) {
QualType R = TInfo->getType();

assert(R->isFunctionType())((void)0);
if (R.getCanonicalType()->castAs<FunctionType>()->getCmseNSCallAttr())
1
The object is a 'FunctionType'→
2
←
Assuming the condition is false→
3
←
Taking false branch→
  Diag(D.getIdentifierLoc(), diag::err_function_decl_cmse_ns_call);

SmallVector<TemplateParameterList *, 4> TemplateParamLists;
for (TemplateParameterList *TPL : TemplateParamListsRef)
4
←
Assuming '__begin1' is equal to '__end1'→
  TemplateParamLists.push_back(TPL);
if (TemplateParameterList *Invented = D.getInventedTemplateParameterList()) {
5
←
Assuming 'Invented' is null→
6
←
Taking false branch→
  if (!TemplateParamLists.empty() &&
      Invented->getDepth() == TemplateParamLists.back()->getDepth())
    TemplateParamLists.back() = Invented;
  else
    TemplateParamLists.push_back(Invented);
}

// TODO: consider using NameInfo for diagnostic.
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
7
←
Calling 'Sema::GetNameForDeclarator'→
9
←
Returning from 'Sema::GetNameForDeclarator'→
DeclarationName Name = NameInfo.getName();
StorageClass SC = getFunctionStorageClass(*this, D);
10
←
Calling 'getFunctionStorageClass'→
13
←
Returning from 'getFunctionStorageClass'→

if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
14
←
Assuming 'TSCS' is 0→
15
←
Taking false branch→
  Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
       diag::err_invalid_thread)
    << DeclSpec::getSpecifierName(TSCS);

if (D.isFirstDeclarationOfMember())
16
←
Taking false branch→
  adjustMemberFunctionCC(R, D.isStaticMember(), D.isCtorOrDtor(),
                         D.getIdentifierLoc());

bool isFriend = false;
FunctionTemplateDecl *FunctionTemplate = nullptr;
bool isMemberSpecialization = false;
bool isFunctionTemplateSpecialization = false;

bool isDependentClassScopeExplicitSpecialization = false;
bool HasExplicitTemplateArgs = false;
TemplateArgumentListInfo TemplateArgs;

bool isVirtualOkay = false;

DeclContext *OriginalDC = DC;
bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC);

FunctionDecl *NewFD = CreateNewFunctionDecl(*this, D, DC, R, TInfo, SC,
17
←
Calling 'CreateNewFunctionDecl'→
45
←
Returning from 'CreateNewFunctionDecl'→
                                            isVirtualOkay);
if (!NewFD) return nullptr;
46
←
Assuming 'NewFD' is non-null→
47
←
Taking false branch→

if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer())
48
←
Assuming field 'OriginalLexicalContext' is null→
  NewFD->setTopLevelDeclInObjCContainer();

// Set the lexical context. If this is a function-scope declaration, or has a
// C++ scope specifier, or is the object of a friend declaration, the lexical
// context will be different from the semantic context.
NewFD->setLexicalDeclContext(CurContext);

if (IsLocalExternDecl48.1
'IsLocalExternDecl' is false
1
'IsLocalExternDecl' is false
)
49
←
Taking false branch→
  NewFD->setLocalExternDecl();

if (getLangOpts().CPlusPlus49.1
Field 'CPlusPlus' is 0
1
Field 'CPlusPlus' is 0
) {
50
←
Taking false branch→
  bool isInline = D.getDeclSpec().isInlineSpecified();
  bool isVirtual = D.getDeclSpec().isVirtualSpecified();
  bool hasExplicit = D.getDeclSpec().hasExplicitSpecifier();
  isFriend = D.getDeclSpec().isFriendSpecified();
  if (isFriend && !isInline && D.isFunctionDefinition()) {
    // C++ [class.friend]p5
    //   A function can be defined in a friend declaration of a
    //   class . . . . Such a function is implicitly inline.
    NewFD->setImplicitlyInline();
  }

  // If this is a method defined in an __interface, and is not a constructor
  // or an overloaded operator, then set the pure flag (isVirtual will already
  // return true).
  if (const CXXRecordDecl *Parent =
        dyn_cast<CXXRecordDecl>(NewFD->getDeclContext())) {
    if (Parent->isInterface() && cast<CXXMethodDecl>(NewFD)->isUserProvided())
      NewFD->setPure(true);

    // C++ [class.union]p2
    //   A union can have member functions, but not virtual functions.
    if (isVirtual && Parent->isUnion())
      Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_in_union);
  }

  SetNestedNameSpecifier(*this, NewFD, D);
  isMemberSpecialization = false;
  isFunctionTemplateSpecialization = false;
  if (D.isInvalidType())
    NewFD->setInvalidDecl();

  // Match up the template parameter lists with the scope specifier, then
  // determine whether we have a template or a template specialization.
  bool Invalid = false;
  TemplateParameterList *TemplateParams =
      MatchTemplateParametersToScopeSpecifier(
          D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
          D.getCXXScopeSpec(),
          D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
              ? D.getName().TemplateId
              : nullptr,
          TemplateParamLists, isFriend, isMemberSpecialization,
          Invalid);
  if (TemplateParams) {
    // Check that we can declare a template here.
    if (CheckTemplateDeclScope(S, TemplateParams))
      NewFD->setInvalidDecl();

    if (TemplateParams->size() > 0) {
      // This is a function template

      // A destructor cannot be a template.
      if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
        Diag(NewFD->getLocation(), diag::err_destructor_template);
        NewFD->setInvalidDecl();
      }

      // If we're adding a template to a dependent context, we may need to
      // rebuilding some of the types used within the template parameter list,
      // now that we know what the current instantiation is.
      if (DC->isDependentContext()) {
        ContextRAII SavedContext(*this, DC);
        if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
          Invalid = true;
      }

      FunctionTemplate = FunctionTemplateDecl::Create(Context, DC,
                                                      NewFD->getLocation(),
                                                      Name, TemplateParams,
                                                      NewFD);
      FunctionTemplate->setLexicalDeclContext(CurContext);
      NewFD->setDescribedFunctionTemplate(FunctionTemplate);

      // For source fidelity, store the other template param lists.
      if (TemplateParamLists.size() > 1) {
        NewFD->setTemplateParameterListsInfo(Context,
            ArrayRef<TemplateParameterList *>(TemplateParamLists)
                .drop_back(1));
      }
    } else {
      // This is a function template specialization.
      isFunctionTemplateSpecialization = true;
      // For source fidelity, store all the template param lists.
      if (TemplateParamLists.size() > 0)
        NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);

      // C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);".
      if (isFriend) {
        // We want to remove the "template<>", found here.
        SourceRange RemoveRange = TemplateParams->getSourceRange();

        // If we remove the template<> and the name is not a
        // template-id, we're actually silently creating a problem:
        // the friend declaration will refer to an untemplated decl,
        // and clearly the user wants a template specialization.  So
        // we need to insert '<>' after the name.
        SourceLocation InsertLoc;
        if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
          InsertLoc = D.getName().getSourceRange().getEnd();
          InsertLoc = getLocForEndOfToken(InsertLoc);
        }

        Diag(D.getIdentifierLoc(), diag::err_template_spec_decl_friend)
          << Name << RemoveRange
          << FixItHint::CreateRemoval(RemoveRange)
          << FixItHint::CreateInsertion(InsertLoc, "<>");
      }
    }
  } else {
    // Check that we can declare a template here.
    if (!TemplateParamLists.empty() && isMemberSpecialization &&
        CheckTemplateDeclScope(S, TemplateParamLists.back()))
      NewFD->setInvalidDecl();

    // All template param lists were matched against the scope specifier:
    // this is NOT (an explicit specialization of) a template.
    if (TemplateParamLists.size() > 0)
      // For source fidelity, store all the template param lists.
      NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
  }

  if (Invalid) {
    NewFD->setInvalidDecl();
    if (FunctionTemplate)
      FunctionTemplate->setInvalidDecl();
  }

  // C++ [dcl.fct.spec]p5:
  //   The virtual specifier shall only be used in declarations of
  //   nonstatic class member functions that appear within a
  //   member-specification of a class declaration; see 10.3.
  //
  if (isVirtual && !NewFD->isInvalidDecl()) {
    if (!isVirtualOkay) {
      Diag(D.getDeclSpec().getVirtualSpecLoc(),
           diag::err_virtual_non_function);
    } else if (!CurContext->isRecord()) {
      // 'virtual' was specified outside of the class.
      Diag(D.getDeclSpec().getVirtualSpecLoc(),
           diag::err_virtual_out_of_class)
        << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
    } else if (NewFD->getDescribedFunctionTemplate()) {
      // C++ [temp.mem]p3:
      //  A member function template shall not be virtual.
      Diag(D.getDeclSpec().getVirtualSpecLoc(),
           diag::err_virtual_member_function_template)
        << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
    } else {
      // Okay: Add virtual to the method.
      NewFD->setVirtualAsWritten(true);
    }

    if (getLangOpts().CPlusPlus14 &&
        NewFD->getReturnType()->isUndeducedType())
      Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_auto_fn_virtual);
  }

  if (getLangOpts().CPlusPlus14 &&
      (NewFD->isDependentContext() ||
       (isFriend && CurContext->isDependentContext())) &&
      NewFD->getReturnType()->isUndeducedType()) {
    // If the function template is referenced directly (for instance, as a
    // member of the current instantiation), pretend it has a dependent type.
    // This is not really justified by the standard, but is the only sane
    // thing to do.
    // FIXME: For a friend function, we have not marked the function as being
    // a friend yet, so 'isDependentContext' on the FD doesn't work.
    const FunctionProtoType *FPT =
        NewFD->getType()->castAs<FunctionProtoType>();
    QualType Result =
        SubstAutoType(FPT->getReturnType(), Context.DependentTy);
    NewFD->setType(Context.getFunctionType(Result, FPT->getParamTypes(),
                                           FPT->getExtProtoInfo()));
  }

  // C++ [dcl.fct.spec]p3:
  //  The inline specifier shall not appear on a block scope function
  //  declaration.
  if (isInline && !NewFD->isInvalidDecl()) {
    if (CurContext->isFunctionOrMethod()) {
      // 'inline' is not allowed on block scope function declaration.
      Diag(D.getDeclSpec().getInlineSpecLoc(),
           diag::err_inline_declaration_block_scope) << Name
        << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
    }
  }

  // C++ [dcl.fct.spec]p6:
  //  The explicit specifier shall be used only in the declaration of a
  //  constructor or conversion function within its class definition;
  //  see 12.3.1 and 12.3.2.
  if (hasExplicit && !NewFD->isInvalidDecl() &&
      !isa<CXXDeductionGuideDecl>(NewFD)) {
    if (!CurContext->isRecord()) {
      // 'explicit' was specified outside of the class.
      Diag(D.getDeclSpec().getExplicitSpecLoc(),
           diag::err_explicit_out_of_class)
          << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecRange());
    } else if (!isa<CXXConstructorDecl>(NewFD) &&
               !isa<CXXConversionDecl>(NewFD)) {
      // 'explicit' was specified on a function that wasn't a constructor
      // or conversion function.
      Diag(D.getDeclSpec().getExplicitSpecLoc(),
           diag::err_explicit_non_ctor_or_conv_function)
          << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecRange());
    }
  }

  ConstexprSpecKind ConstexprKind = D.getDeclSpec().getConstexprSpecifier();
  if (ConstexprKind != ConstexprSpecKind::Unspecified) {
    // C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors
    // are implicitly inline.
    NewFD->setImplicitlyInline();

    // C++11 [dcl.constexpr]p3: functions declared constexpr are required to
    // be either constructors or to return a literal type. Therefore,
    // destructors cannot be declared constexpr.
    if (isa<CXXDestructorDecl>(NewFD) &&
        (!getLangOpts().CPlusPlus20 ||
         ConstexprKind == ConstexprSpecKind::Consteval)) {
      Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor)
          << static_cast<int>(ConstexprKind);
      NewFD->setConstexprKind(getLangOpts().CPlusPlus20
                                  ? ConstexprSpecKind::Unspecified
                                  : ConstexprSpecKind::Constexpr);
    }
    // C++20 [dcl.constexpr]p2: An allocation function, or a
    // deallocation function shall not be declared with the consteval
    // specifier.
    if (ConstexprKind == ConstexprSpecKind::Consteval &&
        (NewFD->getOverloadedOperator() == OO_New ||
         NewFD->getOverloadedOperator() == OO_Array_New ||
         NewFD->getOverloadedOperator() == OO_Delete ||
         NewFD->getOverloadedOperator() == OO_Array_Delete)) {
      Diag(D.getDeclSpec().getConstexprSpecLoc(),
           diag::err_invalid_consteval_decl_kind)
          << NewFD;
      NewFD->setConstexprKind(ConstexprSpecKind::Constexpr);
    }
  }

  // If __module_private__ was specified, mark the function accordingly.
  if (D.getDeclSpec().isModulePrivateSpecified()) {
    if (isFunctionTemplateSpecialization) {
      SourceLocation ModulePrivateLoc
        = D.getDeclSpec().getModulePrivateSpecLoc();
      Diag(ModulePrivateLoc, diag::err_module_private_specialization)
        << 0
        << FixItHint::CreateRemoval(ModulePrivateLoc);
    } else {
      NewFD->setModulePrivate();
      if (FunctionTemplate)
        FunctionTemplate->setModulePrivate();
    }
  }

  if (isFriend) {
    if (FunctionTemplate) {
      FunctionTemplate->setObjectOfFriendDecl();
      FunctionTemplate->setAccess(AS_public);
    }
    NewFD->setObjectOfFriendDecl();
    NewFD->setAccess(AS_public);
  }

  // If a function is defined as defaulted or deleted, mark it as such now.
  // We'll do the relevant checks on defaulted / deleted functions later.
  switch (D.getFunctionDefinitionKind()) {
  case FunctionDefinitionKind::Declaration:
  case FunctionDefinitionKind::Definition:
    break;

  case FunctionDefinitionKind::Defaulted:
    NewFD->setDefaulted();
    break;

  case FunctionDefinitionKind::Deleted:
    NewFD->setDeletedAsWritten();
    break;
  }

  if (isa<CXXMethodDecl>(NewFD) && DC == CurContext &&
      D.isFunctionDefinition()) {
    // C++ [class.mfct]p2:
    //   A member function may be defined (8.4) in its class definition, in
    //   which case it is an inline member function (7.1.2)
    NewFD->setImplicitlyInline();
  }

  if (SC == SC_Static && isa<CXXMethodDecl>(NewFD) &&
      !CurContext->isRecord()) {
    // C++ [class.static]p1:
    //   A data or function member of a class may be declared static
    //   in a class definition, in which case it is a static member of
    //   the class.

    // Complain about the 'static' specifier if it's on an out-of-line
    // member function definition.

    // MSVC permits the use of a 'static' storage specifier on an out-of-line
    // member function template declaration and class member template
    // declaration (MSVC versions before 2015), warn about this.
    Diag(D.getDeclSpec().getStorageClassSpecLoc(),
         ((!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
           cast<CXXRecordDecl>(DC)->getDescribedClassTemplate()) ||
         (getLangOpts().MSVCCompat && NewFD->getDescribedFunctionTemplate()))
         ? diag::ext_static_out_of_line : diag::err_static_out_of_line)
      << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
  }

  // C++11 [except.spec]p15:
  //   A deallocation function with no exception-specification is treated
  //   as if it were specified with noexcept(true).
  const FunctionProtoType *FPT = R->getAs<FunctionProtoType>();
  if ((Name.getCXXOverloadedOperator() == OO_Delete ||
       Name.getCXXOverloadedOperator() == OO_Array_Delete) &&
      getLangOpts().CPlusPlus11 && FPT && !FPT->hasExceptionSpec())
    NewFD->setType(Context.getFunctionType(
        FPT->getReturnType(), FPT->getParamTypes(),
        FPT->getExtProtoInfo().withExceptionSpec(EST_BasicNoexcept)));
}

// Filter out previous declarations that don't match the scope.
FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD),
                     D.getCXXScopeSpec().isNotEmpty() ||
                     isMemberSpecialization ||
                     isFunctionTemplateSpecialization);

// Handle GNU asm-label extension (encoded as an attribute).
if (Expr *E = (Expr*) D.getAsmLabel()) {
51
←
Assuming 'E' is null→
52
←
Taking false branch→
  // The parser guarantees this is a string.
  StringLiteral *SE = cast<StringLiteral>(E);
  NewFD->addAttr(AsmLabelAttr::Create(Context, SE->getString(),
                                      /*IsLiteralLabel=*/true,
                                      SE->getStrTokenLoc(0)));
} else if (!ExtnameUndeclaredIdentifiers.empty()) {
53
←
Assuming the condition is false→
54
←
Taking false branch→
  llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
    ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
  if (I != ExtnameUndeclaredIdentifiers.end()) {
    if (isDeclExternC(NewFD)) {
      NewFD->addAttr(I->second);
      ExtnameUndeclaredIdentifiers.erase(I);
    } else
      Diag(NewFD->getLocation(), diag::warn_redefine_extname_not_applied)
          << /*Variable*/0 << NewFD;
  }
}

// Copy the parameter declarations from the declarator D to the function
// declaration NewFD, if they are available.  First scavenge them into Params.
SmallVector<ParmVarDecl*, 16> Params;
unsigned FTIIdx;
if (D.isFunctionDeclarator(FTIIdx)) {
55
←
Assuming the condition is false→
56
←
Taking false branch→
  DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(FTIIdx).Fun;

  // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
  // function that takes no arguments, not a function that takes a
  // single void argument.
  // We let through "const void" here because Sema::GetTypeForDeclarator
  // already checks for that case.
  if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) {
    for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
      ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
      assert(Param->getDeclContext() != NewFD && "Was set before ?")((void)0);
      Param->setDeclContext(NewFD);
      Params.push_back(Param);

      if (Param->isInvalidDecl())
        NewFD->setInvalidDecl();
    }
  }

  if (!getLangOpts().CPlusPlus) {
    // In C, find all the tag declarations from the prototype and move them
    // into the function DeclContext. Remove them from the surrounding tag
    // injection context of the function, which is typically but not always
    // the TU.
    DeclContext *PrototypeTagContext =
        getTagInjectionContext(NewFD->getLexicalDeclContext());
    for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) {
      auto *TD = dyn_cast<TagDecl>(NonParmDecl);

      // We don't want to reparent enumerators. Look at their parent enum
      // instead.
      if (!TD) {
        if (auto *ECD = dyn_cast<EnumConstantDecl>(NonParmDecl))
          TD = cast<EnumDecl>(ECD->getDeclContext());
      }
      if (!TD)
        continue;
      DeclContext *TagDC = TD->getLexicalDeclContext();
      if (!TagDC->containsDecl(TD))
        continue;
      TagDC->removeDecl(TD);
      TD->setDeclContext(NewFD);
      NewFD->addDecl(TD);

      // Preserve the lexical DeclContext if it is not the surrounding tag
      // injection context of the FD. In this example, the semantic context of
      // E will be f and the lexical context will be S, while both the
      // semantic and lexical contexts of S will be f:
      //   void f(struct S { enum E { a } f; } s);
      if (TagDC != PrototypeTagContext)
        TD->setLexicalDeclContext(TagDC);
    }
  }
} else if (const FunctionProtoType *FT57.1
'FT' is null
1
'FT' is null
 = R->getAs<FunctionProtoType>()) {
57
←
Assuming the object is not a 'FunctionProtoType'→
58
←
Taking false branch→
  // When we're declaring a function with a typedef, typeof, etc as in the
  // following example, we'll need to synthesize (unnamed)
  // parameters for use in the declaration.
  //
  // @code
  // typedef void fn(int);
  // fn f;
  // @endcode

  // Synthesize a parameter for each argument type.
  for (const auto &AI : FT->param_types()) {
    ParmVarDecl *Param =
        BuildParmVarDeclForTypedef(NewFD, D.getIdentifierLoc(), AI);
    Param->setScopeInfo(0, Params.size());
    Params.push_back(Param);
  }
} else {
  assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&((void)0)
         "Should not need args for typedef of non-prototype fn")((void)0);
}

// Finally, we know we have the right number of parameters, install them.
NewFD->setParams(Params);

if (D.getDeclSpec().isNoreturnSpecified())
59
←
Assuming the condition is false→
60
←
Taking false branch→
  NewFD->addAttr(C11NoReturnAttr::Create(Context,
                                         D.getDeclSpec().getNoreturnSpecLoc(),
                                         AttributeCommonInfo::AS_Keyword));

// Functions returning a variably modified type violate C99 6.7.5.2p2
// because all functions have linkage.
if (!NewFD->isInvalidDecl() &&
61
←
Assuming the condition is false→
62
←
Taking false branch→
    NewFD->getReturnType()->isVariablyModifiedType()) {
  Diag(NewFD->getLocation(), diag::err_vm_func_decl);
  NewFD->setInvalidDecl();
}

// Apply an implicit SectionAttr if '#pragma clang section text' is active
if (PragmaClangTextSection.Valid && D.isFunctionDefinition() &&
63
←
Assuming field 'Valid' is false→
    !NewFD->hasAttr<SectionAttr>())
  NewFD->addAttr(PragmaClangTextSectionAttr::CreateImplicit(
      Context, PragmaClangTextSection.SectionName,
      PragmaClangTextSection.PragmaLocation, AttributeCommonInfo::AS_Pragma));

// Apply an implicit SectionAttr if #pragma code_seg is active.
if (CodeSegStack.CurrentValue && D.isFunctionDefinition() &&
64
←
Assuming field 'CurrentValue' is null→
    !NewFD->hasAttr<SectionAttr>()) {
  NewFD->addAttr(SectionAttr::CreateImplicit(
      Context, CodeSegStack.CurrentValue->getString(),
      CodeSegStack.CurrentPragmaLocation, AttributeCommonInfo::AS_Pragma,
      SectionAttr::Declspec_allocate));
  if (UnifySection(CodeSegStack.CurrentValue->getString(),
                   ASTContext::PSF_Implicit | ASTContext::PSF_Execute |
                       ASTContext::PSF_Read,
                   NewFD))
    NewFD->dropAttr<SectionAttr>();
}

// Apply an implicit CodeSegAttr from class declspec or
// apply an implicit SectionAttr from #pragma code_seg if active.
if (!NewFD->hasAttr<CodeSegAttr>()) {
65
←
Taking true branch→
  if (Attr *SAttr65.1
'SAttr' is null
1
'SAttr' is null
 = getImplicitCodeSegOrSectionAttrForFunction(NewFD,
66
←
Taking false branch→
                                                               D.isFunctionDefinition())) {
    NewFD->addAttr(SAttr);
  }
}

// Handle attributes.
ProcessDeclAttributes(S, NewFD, D);

if (getLangOpts().OpenCL) {
67
←
Assuming field 'OpenCL' is 0→
68
←
Taking false branch→
  // OpenCL v1.1 s6.5: Using an address space qualifier in a function return
  // type declaration will generate a compilation error.
  LangAS AddressSpace = NewFD->getReturnType().getAddressSpace();
  if (AddressSpace != LangAS::Default) {
    Diag(NewFD->getLocation(),
         diag::err_opencl_return_value_with_address_space);
    NewFD->setInvalidDecl();
  }
}

if (LangOpts.SYCLIsDevice || (LangOpts.OpenMP && LangOpts.OpenMPIsDevice))
69
←
Assuming field 'SYCLIsDevice' is 0→
70
←
Assuming field 'OpenMP' is 0→
  checkDeviceDecl(NewFD, D.getBeginLoc());

if (!getLangOpts().CPlusPlus) {
71
←
Assuming field 'CPlusPlus' is not equal to 0→
72
←
Taking false branch→
  // Perform semantic checking on the function declaration.
  if (!NewFD->isInvalidDecl() && NewFD->isMain())
    CheckMain(NewFD, D.getDeclSpec());

  if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
    CheckMSVCRTEntryPoint(NewFD);

  if (!NewFD->isInvalidDecl())
    D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
                                                isMemberSpecialization));
  else if (!Previous.empty())
    // Recover gracefully from an invalid redeclaration.
    D.setRedeclaration(true);
  assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||((void)0)
          Previous.getResultKind() != LookupResult::FoundOverloaded) &&((void)0)
         "previous declaration set still overloaded")((void)0);

  // Diagnose no-prototype function declarations with calling conventions that
  // don't support variadic calls. Only do this in C and do it after merging
  // possibly prototyped redeclarations.
  const FunctionType *FT = NewFD->getType()->castAs<FunctionType>();
  if (isa<FunctionNoProtoType>(FT) && !D.isFunctionDefinition()) {
    CallingConv CC = FT->getExtInfo().getCC();
    if (!supportsVariadicCall(CC)) {
      // Windows system headers sometimes accidentally use stdcall without
      // (void) parameters, so we relax this to a warning.
      int DiagID =
          CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr;
      Diag(NewFD->getLocation(), DiagID)
          << FunctionType::getNameForCallConv(CC);
    }
  }

 if (NewFD->getReturnType().hasNonTrivialToPrimitiveDestructCUnion() ||
     NewFD->getReturnType().hasNonTrivialToPrimitiveCopyCUnion())
   checkNonTrivialCUnion(NewFD->getReturnType(),
                         NewFD->getReturnTypeSourceRange().getBegin(),
                         NTCUC_FunctionReturn, NTCUK_Destruct|NTCUK_Copy);
} else {
  // C++11 [replacement.functions]p3:
  //  The program's definitions shall not be specified as inline.
  //
  // N.B. We diagnose declarations instead of definitions per LWG issue 2340.
  //
  // Suppress the diagnostic if the function is __attribute__((used)), since
  // that forces an external definition to be emitted.
  if (D.getDeclSpec().isInlineSpecified() &&
73
←
Assuming the condition is false→
      NewFD->isReplaceableGlobalAllocationFunction() &&
      !NewFD->hasAttr<UsedAttr>())
    Diag(D.getDeclSpec().getInlineSpecLoc(),
         diag::ext_operator_new_delete_declared_inline)
      << NewFD->getDeclName();

  // If the declarator is a template-id, translate the parser's template
  // argument list into our AST format.
  if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
74
←
Assuming the condition is false→
75
←
Taking false branch→
    TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
    TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
    TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
    ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
                                       TemplateId->NumArgs);
    translateTemplateArguments(TemplateArgsPtr,
                               TemplateArgs);

    HasExplicitTemplateArgs = true;

    if (NewFD->isInvalidDecl()) {
      HasExplicitTemplateArgs = false;
    } else if (FunctionTemplate) {
      // Function template with explicit template arguments.
      Diag(D.getIdentifierLoc(), diag::err_function_template_partial_spec)
        << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc);

      HasExplicitTemplateArgs = false;
    } else {
      assert((isFunctionTemplateSpecialization ||((void)0)
              D.getDeclSpec().isFriendSpecified()) &&((void)0)
             "should have a 'template<>' for this decl")((void)0);
      // "friend void foo<>(int);" is an implicit specialization decl.
      isFunctionTemplateSpecialization = true;
    }
  } else if (isFriend75.1
'isFriend' is false
1
'isFriend' is false
 && isFunctionTemplateSpecialization) {
    // This combination is only possible in a recovery case;  the user
    // wrote something like:
    //   template <> friend void foo(int);
    // which we're recovering from as if the user had written:
    //   friend void foo<>(int);
    // Go ahead and fake up a template id.
    HasExplicitTemplateArgs = true;
    TemplateArgs.setLAngleLoc(D.getIdentifierLoc());
    TemplateArgs.setRAngleLoc(D.getIdentifierLoc());
  }

  // We do not add HD attributes to specializations here because
  // they may have different constexpr-ness compared to their
  // templates and, after maybeAddCUDAHostDeviceAttrs() is applied,
  // may end up with different effective targets. Instead, a
  // specialization inherits its target attributes from its template
  // in the CheckFunctionTemplateSpecialization() call below.
  if (getLangOpts().CUDA && !isFunctionTemplateSpecialization)
76
←
Assuming field 'CUDA' is 0→
    maybeAddCUDAHostDeviceAttrs(NewFD, Previous);

  // If it's a friend (and only if it's a friend), it's possible
  // that either the specialized function type or the specialized
  // template is dependent, and therefore matching will fail.  In
  // this case, don't check the specialization yet.
  if (isFunctionTemplateSpecialization76.1
'isFunctionTemplateSpecialization' is false
1
'isFunctionTemplateSpecialization' is false
 && isFriend &&
77
←
Taking false branch→
      (NewFD->getType()->isDependentType() || DC->isDependentContext() ||
       TemplateSpecializationType::anyInstantiationDependentTemplateArguments(
           TemplateArgs.arguments()))) {
    assert(HasExplicitTemplateArgs &&((void)0)
           "friend function specialization without template args")((void)0);
    if (CheckDependentFunctionTemplateSpecialization(NewFD, TemplateArgs,
                                                     Previous))
      NewFD->setInvalidDecl();
  } else if (isFunctionTemplateSpecialization77.1
'isFunctionTemplateSpecialization' is false
1
'isFunctionTemplateSpecialization' is false
) {
78
←
Taking false branch→
    if (CurContext->isDependentContext() && CurContext->isRecord()
        && !isFriend) {
      isDependentClassScopeExplicitSpecialization = true;
    } else if (!NewFD->isInvalidDecl() &&
               CheckFunctionTemplateSpecialization(
                   NewFD, (HasExplicitTemplateArgs ? &TemplateArgs : nullptr),
                   Previous))
      NewFD->setInvalidDecl();

    // C++ [dcl.stc]p1:
    //   A storage-class-specifier shall not be specified in an explicit
    //   specialization (14.7.3)
    FunctionTemplateSpecializationInfo *Info =
        NewFD->getTemplateSpecializationInfo();
    if (Info && SC != SC_None) {
      if (SC != Info->getTemplate()->getTemplatedDecl()->getStorageClass())
        Diag(NewFD->getLocation(),
             diag::err_explicit_specialization_inconsistent_storage_class)
          << SC
          << FixItHint::CreateRemoval(
                                    D.getDeclSpec().getStorageClassSpecLoc());

      else
        Diag(NewFD->getLocation(),
             diag::ext_explicit_specialization_storage_class)
          << FixItHint::CreateRemoval(
                                    D.getDeclSpec().getStorageClassSpecLoc());
    }
  } else if (isMemberSpecialization78.1
'isMemberSpecialization' is false
1
'isMemberSpecialization' is false
 && isa<CXXMethodDecl>(NewFD)) {
    if (CheckMemberSpecialization(NewFD, Previous))
        NewFD->setInvalidDecl();
  }

  // Perform semantic checking on the function declaration.
  if (!isDependentClassScopeExplicitSpecialization78.2
'isDependentClassScopeExplicitSpecialization' is false
2
'isDependentClassScopeExplicitSpecialization' is false
) {
79
←
Taking true branch→
    if (!NewFD->isInvalidDecl() && NewFD->isMain())
80
←
Assuming the condition is false→
      CheckMain(NewFD, D.getDeclSpec());

    if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
      CheckMSVCRTEntryPoint(NewFD);

    if (!NewFD->isInvalidDecl())
81
←
Taking false branch→
      D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
                                                  isMemberSpecialization));
    else if (!Previous.empty())
82
←
Assuming the condition is false→
83
←
Taking false branch→
      // Recover gracefully from an invalid redeclaration.
      D.setRedeclaration(true);
  }

  assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||((void)0)
          Previous.getResultKind() != LookupResult::FoundOverloaded) &&((void)0)
         "previous declaration set still overloaded")((void)0);

  NamedDecl *PrincipalDecl = (FunctionTemplate83.1
'FunctionTemplate' is null

83.1	'FunctionTemplate' is null

←

'?' condition is false

→

9731 ? cast<NamedDecl>(FunctionTemplate) 9732 : NewFD); 9733 9734 if (isFriend

84.1	'isFriend' is false

84.1	'isFriend' is false

&& NewFD->getPreviousDecl()) { 9735 AccessSpecifier Access = AS_public; 9736 if (!NewFD->isInvalidDecl()) 9737 Access = NewFD->getPreviousDecl()->getAccess(); 9738 9739 NewFD->setAccess(Access); 9740 if (FunctionTemplate) FunctionTemplate->setAccess(Access); 9741 } 9742 9743 if (NewFD->isOverloadedOperator() && !DC->isRecord() && 9744 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary)) 9745 PrincipalDecl->setNonMemberOperator(); 9746 9747 // If we have a function template, check the template parameter 9748 // list. This will check and merge default template arguments. 9749 if (FunctionTemplate

84.2	'FunctionTemplate' is null

84.2	'FunctionTemplate' is null

) {

←

Taking false branch

→

9750 FunctionTemplateDecl *PrevTemplate = 9751 FunctionTemplate->getPreviousDecl(); 9752 CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(), 9753 PrevTemplate ? PrevTemplate->getTemplateParameters() 9754 : nullptr, 9755 D.getDeclSpec().isFriendSpecified() 9756 ? (D.isFunctionDefinition() 9757 ? TPC_FriendFunctionTemplateDefinition 9758 : TPC_FriendFunctionTemplate) 9759 : (D.getCXXScopeSpec().isSet() && 9760 DC && DC->isRecord() && 9761 DC->isDependentContext()) 9762 ? TPC_ClassTemplateMember 9763 : TPC_FunctionTemplate); 9764 } 9765 9766 if (NewFD->isInvalidDecl()) {

←

Assuming the condition is false

→

←

Taking false branch

→

9767 // Ignore all the rest of this. 9768 } else if (!D.isRedeclaration()) {

←

Assuming the condition is false

→

←

Taking false branch

→

9769 struct ActOnFDArgs ExtraArgs = { S, D, TemplateParamLists, 9770 AddToScope }; 9771 // Fake up an access specifier if it's supposed to be a class member. 9772 if (isa<CXXRecordDecl>(NewFD->getDeclContext())) 9773 NewFD->setAccess(AS_public); 9774 9775 // Qualified decls generally require a previous declaration. 9776 if (D.getCXXScopeSpec().isSet()) { 9777 // ...with the major exception of templated-scope or 9778 // dependent-scope friend declarations. 9779 9780 // TODO: we currently also suppress this check in dependent 9781 // contexts because (1) the parameter depth will be off when 9782 // matching friend templates and (2) we might actually be 9783 // selecting a friend based on a dependent factor. But there 9784 // are situations where these conditions don't apply and we 9785 // can actually do this check immediately. 9786 // 9787 // Unless the scope is dependent, it's always an error if qualified 9788 // redeclaration lookup found nothing at all. Diagnose that now; 9789 // nothing will diagnose that error later. 9790 if (isFriend && 9791 (D.getCXXScopeSpec().getScopeRep()->isDependent() || 9792 (!Previous.empty() && CurContext->isDependentContext()))) { 9793 // ignore these 9794 } else if (NewFD->isCPUDispatchMultiVersion() || 9795 NewFD->isCPUSpecificMultiVersion()) { 9796 // ignore this, we allow the redeclaration behavior here to create new 9797 // versions of the function. 9798 } else { 9799 // The user tried to provide an out-of-line definition for a 9800 // function that is a member of a class or namespace, but there 9801 // was no such member function declared (C++ [class.mfct]p2, 9802 // C++ [namespace.memdef]p2). For example: 9803 // 9804 // class X { 9805 // void f() const; 9806 // }; 9807 // 9808 // void X::f() { } // ill-formed 9809 // 9810 // Complain about this problem, and attempt to suggest close 9811 // matches (e.g., those that differ only in cv-qualifiers and 9812 // whether the parameter types are references). 9813 9814 if (NamedDecl *Result = DiagnoseInvalidRedeclaration( 9815 *this, Previous, NewFD, ExtraArgs, false, nullptr)) { 9816 AddToScope = ExtraArgs.AddToScope; 9817 return Result; 9818 } 9819 } 9820 9821 // Unqualified local friend declarations are required to resolve 9822 // to something. 9823 } else if (isFriend && cast<CXXRecordDecl>(CurContext)->isLocalClass()) { 9824 if (NamedDecl *Result = DiagnoseInvalidRedeclaration( 9825 *this, Previous, NewFD, ExtraArgs, true, S)) { 9826 AddToScope = ExtraArgs.AddToScope; 9827 return Result; 9828 } 9829 } 9830 } else if (!D.isFunctionDefinition() && 9831 isa<CXXMethodDecl>(NewFD) && NewFD->isOutOfLine() &&

←

'NewFD' is not a 'CXXMethodDecl'

→

9832 !isFriend && !isFunctionTemplateSpecialization && 9833 !isMemberSpecialization) { 9834 // An out-of-line member function declaration must also be a 9835 // definition (C++ [class.mfct]p2). 9836 // Note that this is not the case for explicit specializations of 9837 // function templates or member functions of class templates, per 9838 // C++ [temp.expl.spec]p2. We also allow these declarations as an 9839 // extension for compatibility with old SWIG code which likes to 9840 // generate them. 9841 Diag(NewFD->getLocation(), diag::ext_out_of_line_declaration) 9842 << D.getCXXScopeSpec().getRange(); 9843 } 9844 } 9845 9846 // If this is the first declaration of a library builtin function, add 9847 // attributes as appropriate. 9848 if (!D.isRedeclaration() && 9849 NewFD->getDeclContext()->getRedeclContext()->isFileContext()) { 9850 if (IdentifierInfo *II = Previous.getLookupName().getAsIdentifierInfo()) { 9851 if (unsigned BuiltinID = II->getBuiltinID()) { 9852 if (NewFD->getLanguageLinkage() == CLanguageLinkage) { 9853 // Validate the type matches unless this builtin is specified as 9854 // matching regardless of its declared type. 9855 if (Context.BuiltinInfo.allowTypeMismatch(BuiltinID)) { 9856 NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID)); 9857 } else { 9858 ASTContext::GetBuiltinTypeError Error; 9859 LookupNecessaryTypesForBuiltin(S, BuiltinID); 9860 QualType BuiltinType = Context.GetBuiltinType(BuiltinID, Error); 9861 9862 if (!Error && !BuiltinType.isNull() && 9863 Context.hasSameFunctionTypeIgnoringExceptionSpec( 9864 NewFD->getType(), BuiltinType)) 9865 NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID)); 9866 } 9867 } else if (BuiltinID == Builtin::BI__GetExceptionInfo && 9868 Context.getTargetInfo().getCXXABI().isMicrosoft()) { 9869 // FIXME: We should consider this a builtin only in the std namespace. 9870 NewFD->addAttr(BuiltinAttr::CreateImplicit(Context, BuiltinID)); 9871 } 9872 } 9873 } 9874 } 9875 9876 ProcessPragmaWeak(S, NewFD); 9877 checkAttributesAfterMerging(*this, *NewFD); 9878 9879 AddKnownFunctionAttributes(NewFD); 9880 9881 if (NewFD->hasAttr<OverloadableAttr>() &&

←

Taking true branch

→

9882 !NewFD->getType()->getAs<FunctionProtoType>()) {

←

Assuming the object is not a 'FunctionProtoType'

→

9883 Diag(NewFD->getLocation(), 9884 diag::err_attribute_overloadable_no_prototype) 9885 << NewFD; 9886 9887 // Turn this into a variadic function with no parameters. 9888 const FunctionType *FT = NewFD->getType()->getAs<FunctionType>();

←

Assuming the object is not a 'FunctionType'

→

←

'FT' initialized to a null pointer value

→

9889 FunctionProtoType::ExtProtoInfo EPI( 9890 Context.getDefaultCallingConvention(true, false)); 9891 EPI.Variadic = true; 9892 EPI.ExtInfo = FT->getExtInfo();

←

Called C++ object pointer is null

9893 9894 QualType R = Context.getFunctionType(FT->getReturnType(), None, EPI); 9895 NewFD->setType(R); 9896 } 9897 9898 // If there's a #pragma GCC visibility in scope, and this isn't a class 9899 // member, set the visibility of this function. 9900 if (!DC->isRecord() && NewFD->isExternallyVisible()) 9901 AddPushedVisibilityAttribute(NewFD); 9902 9903 // If there's a #pragma clang arc_cf_code_audited in scope, consider 9904 // marking the function. 9905 AddCFAuditedAttribute(NewFD); 9906 9907 // If this is a function definition, check if we have to apply optnone due to 9908 // a pragma. 9909 if(D.isFunctionDefinition()) 9910 AddRangeBasedOptnone(NewFD); 9911 9912 // If this is the first declaration of an extern C variable, update 9913 // the map of such variables. 9914 if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() && 9915 isIncompleteDeclExternC(*this, NewFD)) 9916 RegisterLocallyScopedExternCDecl(NewFD, S); 9917 9918 // Set this FunctionDecl's range up to the right paren. 9919 NewFD->setRangeEnd(D.getSourceRange().getEnd()); 9920 9921 if (D.isRedeclaration() && !Previous.empty()) { 9922 NamedDecl *Prev = Previous.getRepresentativeDecl(); 9923 checkDLLAttributeRedeclaration(*this, Prev, NewFD, 9924 isMemberSpecialization || 9925 isFunctionTemplateSpecialization, 9926 D.isFunctionDefinition()); 9927 } 9928 9929 if (getLangOpts().CUDA) { 9930 IdentifierInfo *II = NewFD->getIdentifier(); 9931 if (II && II->isStr(getCudaConfigureFuncName()) && 9932 !NewFD->isInvalidDecl() && 9933 NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) { 9934 if (!R->castAs<FunctionType>()->getReturnType()->isScalarType()) 9935 Diag(NewFD->getLocation(), diag::err_config_scalar_return) 9936 << getCudaConfigureFuncName(); 9937 Context.setcudaConfigureCallDecl(NewFD); 9938 } 9939 9940 // Variadic functions, other than a *declaration* of printf, are not allowed 9941 // in device-side CUDA code, unless someone passed 9942 // -fcuda-allow-variadic-functions. 9943 if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() && 9944 (NewFD->hasAttr<CUDADeviceAttr>() || 9945 NewFD->hasAttr<CUDAGlobalAttr>()) && 9946 !(II && II->isStr("printf") && NewFD->isExternC() && 9947 !D.isFunctionDefinition())) { 9948 Diag(NewFD->getLocation(), diag::err_variadic_device_fn); 9949 } 9950 } 9951 9952 MarkUnusedFileScopedDecl(NewFD); 9953 9954 9955 9956 if (getLangOpts().OpenCL && NewFD->hasAttr<OpenCLKernelAttr>()) { 9957 // OpenCL v1.2 s6.8 static is invalid for kernel functions. 9958 if ((getLangOpts().OpenCLVersion >= 120) 9959 && (SC == SC_Static)) { 9960 Diag(D.getIdentifierLoc(), diag::err_static_kernel); 9961 D.setInvalidType(); 9962 } 9963 9964 // OpenCL v1.2, s6.9 -- Kernels can only have return type void. 9965 if (!NewFD->getReturnType()->isVoidType()) { 9966 SourceRange RTRange = NewFD->getReturnTypeSourceRange(); 9967 Diag(D.getIdentifierLoc(), diag::err_expected_kernel_void_return_type) 9968 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "void") 9969 : FixItHint()); 9970 D.setInvalidType(); 9971 } 9972 9973 llvm::SmallPtrSet<const Type *, 16> ValidTypes; 9974 for (auto Param : NewFD->parameters()) 9975 checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes); 9976 9977 if (getLangOpts().OpenCLCPlusPlus) { 9978 if (DC->isRecord()) { 9979 Diag(D.getIdentifierLoc(), diag::err_method_kernel); 9980 D.setInvalidType(); 9981 } 9982 if (FunctionTemplate) { 9983 Diag(D.getIdentifierLoc(), diag::err_template_kernel); 9984 D.setInvalidType(); 9985 } 9986 } 9987 } 9988 9989 if (getLangOpts().CPlusPlus) { 9990 if (FunctionTemplate) { 9991 if (NewFD->isInvalidDecl()) 9992 FunctionTemplate->setInvalidDecl(); 9993 return FunctionTemplate; 9994 } 9995 9996 if (isMemberSpecialization && !NewFD->isInvalidDecl()) 9997 CompleteMemberSpecialization(NewFD, Previous); 9998 } 9999 10000 for (const ParmVarDecl *Param : NewFD->parameters()) { 10001 QualType PT = Param->getType(); 10002 10003 // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value 10004 // types. 10005 if (getLangOpts().OpenCLVersion >= 200 || getLangOpts().OpenCLCPlusPlus) { 10006 if(const PipeType *PipeTy = PT->getAs<PipeType>()) { 10007 QualType ElemTy = PipeTy->getElementType(); 10008 if (ElemTy->isReferenceType() || ElemTy->isPointerType()) { 10009 Diag(Param->getTypeSpecStartLoc(), diag::err_reference_pipe_type ); 10010 D.setInvalidType(); 10011 } 10012 } 10013 } 10014 } 10015 10016 // Here we have an function template explicit specialization at class scope. 10017 // The actual specialization will be postponed to template instatiation 10018 // time via the ClassScopeFunctionSpecializationDecl node. 10019 if (isDependentClassScopeExplicitSpecialization) { 10020 ClassScopeFunctionSpecializationDecl *NewSpec = 10021 ClassScopeFunctionSpecializationDecl::Create( 10022 Context, CurContext, NewFD->getLocation(), 10023 cast<CXXMethodDecl>(NewFD), 10024 HasExplicitTemplateArgs, TemplateArgs); 10025 CurContext->addDecl(NewSpec); 10026 AddToScope = false; 10027 } 10028 10029 // Diagnose availability attributes. Availability cannot be used on functions 10030 // that are run during load/unload. 10031 if (const auto *attr = NewFD->getAttr<AvailabilityAttr>()) { 10032 if (NewFD->hasAttr<ConstructorAttr>()) { 10033 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer) 10034 << 1; 10035 NewFD->dropAttr<AvailabilityAttr>(); 10036 } 10037 if (NewFD->hasAttr<DestructorAttr>()) { 10038 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer) 10039 << 2; 10040 NewFD->dropAttr<AvailabilityAttr>(); 10041 } 10042 } 10043 10044 // Diagnose no_builtin attribute on function declaration that are not a 10045 // definition. 10046 // FIXME: We should really be doing this in 10047 // SemaDeclAttr.cpp::handleNoBuiltinAttr, unfortunately we only have access to 10048 // the FunctionDecl and at this point of the code 10049 // FunctionDecl::isThisDeclarationADefinition() which always returns `false` 10050 // because Sema::ActOnStartOfFunctionDef has not been called yet. 10051 if (const auto *NBA = NewFD->getAttr<NoBuiltinAttr>()) 10052 switch (D.getFunctionDefinitionKind()) { 10053 case FunctionDefinitionKind::Defaulted: 10054 case FunctionDefinitionKind::Deleted: 10055 Diag(NBA->getLocation(), 10056 diag::err_attribute_no_builtin_on_defaulted_deleted_function) 10057 << NBA->getSpelling(); 10058 break; 10059 case FunctionDefinitionKind::Declaration: 10060 Diag(NBA->getLocation(), diag::err_attribute_no_builtin_on_non_definition) 10061 << NBA->getSpelling(); 10062 break; 10063 case FunctionDefinitionKind::Definition: 10064 break; 10065 } 10066 10067 return NewFD; 10068} 10069 10070/// Return a CodeSegAttr from a containing class. The Microsoft docs say 10071/// when __declspec(code_seg) "is applied to a class, all member functions of 10072/// the class and nested classes -- this includes compiler-generated special 10073/// member functions -- are put in the specified segment." 10074/// The actual behavior is a little more complicated. The Microsoft compiler 10075/// won't check outer classes if there is an active value from #pragma code_seg. 10076/// The CodeSeg is always applied from the direct parent but only from outer 10077/// classes when the #pragma code_seg stack is empty. See: 10078/// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer 10079/// available since MS has removed the page. 10080static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) { 10081 const auto *Method = dyn_cast<CXXMethodDecl>(FD); 10082 if (!Method) 10083 return nullptr; 10084 const CXXRecordDecl *Parent = Method->getParent(); 10085 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) { 10086 Attr *NewAttr = SAttr->clone(S.getASTContext()); 10087 NewAttr->setImplicit(true); 10088 return NewAttr; 10089 } 10090 10091 // The Microsoft compiler won't check outer classes for the CodeSeg 10092 // when the #pragma code_seg stack is active. 10093 if (S.CodeSegStack.CurrentValue) 10094 return nullptr; 10095 10096 while ((Parent = dyn_cast<CXXRecordDecl>(Parent->getParent()))) { 10097 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) { 10098 Attr *NewAttr = SAttr->clone(S.getASTContext()); 10099 NewAttr->setImplicit(true); 10100 return NewAttr; 10101 } 10102 } 10103 return nullptr; 10104} 10105 10106/// Returns an implicit CodeSegAttr if a __declspec(code_seg) is found on a 10107/// containing class. Otherwise it will return implicit SectionAttr if the 10108/// function is a definition and there is an active value on CodeSegStack 10109/// (from the current #pragma code-seg value). 10110/// 10111/// \param FD Function being declared. 10112/// \param IsDefinition Whether it is a definition or just a declarartion. 10113/// \returns A CodeSegAttr or SectionAttr to apply to the function or 10114/// nullptr if no attribute should be added. 10115Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD, 10116 bool IsDefinition) { 10117 if (Attr *A = getImplicitCodeSegAttrFromClass(*this, FD)) 10118 return A; 10119 if (!FD->hasAttr<SectionAttr>() && IsDefinition && 10120 CodeSegStack.CurrentValue) 10121 return SectionAttr::CreateImplicit( 10122 getASTContext(), CodeSegStack.CurrentValue->getString(), 10123 CodeSegStack.CurrentPragmaLocation, AttributeCommonInfo::AS_Pragma, 10124 SectionAttr::Declspec_allocate); 10125 return nullptr; 10126} 10127 10128/// Determines if we can perform a correct type check for \p D as a 10129/// redeclaration of \p PrevDecl. If not, we can generally still perform a 10130/// best-effort check. 10131/// 10132/// \param NewD The new declaration. 10133/// \param OldD The old declaration. 10134/// \param NewT The portion of the type of the new declaration to check. 10135/// \param OldT The portion of the type of the old declaration to check. 10136bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD, 10137 QualType NewT, QualType OldT) { 10138 if (!NewD->getLexicalDeclContext()->isDependentContext()) 10139 return true; 10140 10141 // For dependently-typed local extern declarations and friends, we can't 10142 // perform a correct type check in general until instantiation: 10143 // 10144 // int f(); 10145 // template<typename T> void g() { T f(); } 10146 // 10147 // (valid if g() is only instantiated with T = int). 10148 if (NewT->isDependentType() && 10149 (NewD->isLocalExternDecl() || NewD->getFriendObjectKind())) 10150 return false; 10151 10152 // Similarly, if the previous declaration was a dependent local extern 10153 // declaration, we don't really know its type yet. 10154 if (OldT->isDependentType() && OldD->isLocalExternDecl()) 10155 return false; 10156 10157 return true; 10158} 10159 10160/// Checks if the new declaration declared in dependent context must be 10161/// put in the same redeclaration chain as the specified declaration. 10162/// 10163/// \param D Declaration that is checked. 10164/// \param PrevDecl Previous declaration found with proper lookup method for the 10165/// same declaration name. 10166/// \returns True if D must be added to the redeclaration chain which PrevDecl 10167/// belongs to. 10168/// 10169bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) { 10170 if (!D->getLexicalDeclContext()->isDependentContext()) 10171 return true; 10172 10173 // Don't chain dependent friend function definitions until instantiation, to 10174 // permit cases like 10175 // 10176 // void func(); 10177 // template<typename T> class C1 { friend void func() {} }; 10178 // template<typename T> class C2 { friend void func() {} }; 10179 // 10180 // ... which is valid if only one of C1 and C2 is ever instantiated. 10181 // 10182 // FIXME: This need only apply to function definitions. For now, we proxy 10183 // this by checking for a file-scope function. We do not want this to apply 10184 // to friend declarations nominating member functions, because that gets in 10185 // the way of access checks. 10186 if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext()) 10187 return false; 10188 10189 auto *VD = dyn_cast<ValueDecl>(D); 10190 auto *PrevVD = dyn_cast<ValueDecl>(PrevDecl); 10191 return !VD || !PrevVD || 10192 canFullyTypeCheckRedeclaration(VD, PrevVD, VD->getType(), 10193 PrevVD->getType()); 10194} 10195 10196/// Check the target attribute of the function for MultiVersion 10197/// validity. 10198/// 10199/// Returns true if there was an error, false otherwise. 10200static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) { 10201 const auto *TA = FD->getAttr<TargetAttr>(); 10202 assert(TA && "MultiVersion Candidate requires a target attribute")((void)0); 10203 ParsedTargetAttr ParseInfo = TA->parse(); 10204 const TargetInfo &TargetInfo = S.Context.getTargetInfo(); 10205 enum ErrType { Feature = 0, Architecture = 1 }; 10206 10207 if (!ParseInfo.Architecture.empty() && 10208 !TargetInfo.validateCpuIs(ParseInfo.Architecture)) { 10209 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) 10210 << Architecture << ParseInfo.Architecture; 10211 return true; 10212 } 10213 10214 for (const auto &Feat : ParseInfo.Features) { 10215 auto BareFeat = StringRef{Feat}.substr(1); 10216 if (Feat[0] == '-') { 10217 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) 10218 << Feature << ("no-" + BareFeat).str(); 10219 return true; 10220 } 10221 10222 if (!TargetInfo.validateCpuSupports(BareFeat) || 10223 !TargetInfo.isValidFeatureName(BareFeat)) { 10224 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option) 10225 << Feature << BareFeat; 10226 return true; 10227 } 10228 } 10229 return false; 10230} 10231 10232// Provide a white-list of attributes that are allowed to be combined with 10233// multiversion functions. 10234static bool AttrCompatibleWithMultiVersion(attr::Kind Kind, 10235 MultiVersionKind MVType) { 10236 // Note: this list/diagnosis must match the list in 10237 // checkMultiversionAttributesAllSame. 10238 switch (Kind) { 10239 default: 10240 return false; 10241 case attr::Used: 10242 return MVType == MultiVersionKind::Target; 10243 case attr::NonNull: 10244 case attr::NoThrow: 10245 return true; 10246 } 10247} 10248 10249static bool checkNonMultiVersionCompatAttributes(Sema &S, 10250 const FunctionDecl *FD, 10251 const FunctionDecl *CausedFD, 10252 MultiVersionKind MVType) { 10253 bool IsCPUSpecificCPUDispatchMVType = 10254 MVType == MultiVersionKind::CPUDispatch || 10255 MVType == MultiVersionKind::CPUSpecific; 10256 const auto Diagnose = [FD, CausedFD, IsCPUSpecificCPUDispatchMVType]( 10257 Sema &S, const Attr *A) { 10258 S.Diag(FD->getLocation(), diag::err_multiversion_disallowed_other_attr) 10259 << IsCPUSpecificCPUDispatchMVType << A; 10260 if (CausedFD) 10261 S.Diag(CausedFD->getLocation(), diag::note_multiversioning_caused_here); 10262 return true; 10263 }; 10264 10265 for (const Attr *A : FD->attrs()) { 10266 switch (A->getKind()) { 10267 case attr::CPUDispatch: 10268 case attr::CPUSpecific: 10269 if (MVType != MultiVersionKind::CPUDispatch && 10270 MVType != MultiVersionKind::CPUSpecific) 10271 return Diagnose(S, A); 10272 break; 10273 case attr::Target: 10274 if (MVType != MultiVersionKind::Target) 10275 return Diagnose(S, A); 10276 break; 10277 default: 10278 if (!AttrCompatibleWithMultiVersion(A->getKind(), MVType)) 10279 return Diagnose(S, A); 10280 break; 10281 } 10282 } 10283 return false; 10284} 10285 10286bool Sema::areMultiversionVariantFunctionsCompatible( 10287 const FunctionDecl *OldFD, const FunctionDecl *NewFD, 10288 const PartialDiagnostic &NoProtoDiagID, 10289 const PartialDiagnosticAt &NoteCausedDiagIDAt, 10290 const PartialDiagnosticAt &NoSupportDiagIDAt, 10291 const PartialDiagnosticAt &DiffDiagIDAt, bool TemplatesSupported, 10292 bool ConstexprSupported, bool CLinkageMayDiffer) { 10293 enum DoesntSupport { 10294 FuncTemplates = 0, 10295 VirtFuncs = 1, 10296 DeducedReturn = 2, 10297 Constructors = 3, 10298 Destructors = 4, 10299 DeletedFuncs = 5, 10300 DefaultedFuncs = 6, 10301 ConstexprFuncs = 7, 10302 ConstevalFuncs = 8, 10303 }; 10304 enum Different { 10305 CallingConv = 0, 10306 ReturnType = 1, 10307 ConstexprSpec = 2, 10308 InlineSpec = 3, 10309 StorageClass = 4, 10310 Linkage = 5, 10311 }; 10312 10313 if (NoProtoDiagID.getDiagID() != 0 && OldFD && 10314 !OldFD->getType()->getAs<FunctionProtoType>()) { 10315 Diag(OldFD->getLocation(), NoProtoDiagID); 10316 Diag(NoteCausedDiagIDAt.first, NoteCausedDiagIDAt.second); 10317 return true; 10318 } 10319 10320 if (NoProtoDiagID.getDiagID() != 0 && 10321 !NewFD->getType()->getAs<FunctionProtoType>()) 10322 return Diag(NewFD->getLocation(), NoProtoDiagID); 10323 10324 if (!TemplatesSupported && 10325 NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate) 10326 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10327 << FuncTemplates; 10328 10329 if (const auto *NewCXXFD = dyn_cast<CXXMethodDecl>(NewFD)) { 10330 if (NewCXXFD->isVirtual()) 10331 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10332 << VirtFuncs; 10333 10334 if (isa<CXXConstructorDecl>(NewCXXFD)) 10335 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10336 << Constructors; 10337 10338 if (isa<CXXDestructorDecl>(NewCXXFD)) 10339 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10340 << Destructors; 10341 } 10342 10343 if (NewFD->isDeleted()) 10344 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10345 << DeletedFuncs; 10346 10347 if (NewFD->isDefaulted()) 10348 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10349 << DefaultedFuncs; 10350 10351 if (!ConstexprSupported && NewFD->isConstexpr()) 10352 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10353 << (NewFD->isConsteval() ? ConstevalFuncs : ConstexprFuncs); 10354 10355 QualType NewQType = Context.getCanonicalType(NewFD->getType()); 10356 const auto *NewType = cast<FunctionType>(NewQType); 10357 QualType NewReturnType = NewType->getReturnType(); 10358 10359 if (NewReturnType->isUndeducedType()) 10360 return Diag(NoSupportDiagIDAt.first, NoSupportDiagIDAt.second) 10361 << DeducedReturn; 10362 10363 // Ensure the return type is identical. 10364 if (OldFD) { 10365 QualType OldQType = Context.getCanonicalType(OldFD->getType()); 10366 const auto *OldType = cast<FunctionType>(OldQType); 10367 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo(); 10368 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo(); 10369 10370 if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) 10371 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << CallingConv; 10372 10373 QualType OldReturnType = OldType->getReturnType(); 10374 10375 if (OldReturnType != NewReturnType) 10376 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << ReturnType; 10377 10378 if (OldFD->getConstexprKind() != NewFD->getConstexprKind()) 10379 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << ConstexprSpec; 10380 10381 if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified()) 10382 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << InlineSpec; 10383 10384 if (OldFD->getStorageClass() != NewFD->getStorageClass()) 10385 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << StorageClass; 10386 10387 if (!CLinkageMayDiffer && OldFD->isExternC() != NewFD->isExternC()) 10388 return Diag(DiffDiagIDAt.first, DiffDiagIDAt.second) << Linkage; 10389 10390 if (CheckEquivalentExceptionSpec( 10391 OldFD->getType()->getAs<FunctionProtoType>(), OldFD->getLocation(), 10392 NewFD->getType()->getAs<FunctionProtoType>(), NewFD->getLocation())) 10393 return true; 10394 } 10395 return false; 10396} 10397 10398static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD, 10399 const FunctionDecl *NewFD, 10400 bool CausesMV, 10401 MultiVersionKind MVType) { 10402 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) { 10403 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported); 10404 if (OldFD) 10405 S.Diag(OldFD->getLocation(), diag::note_previous_declaration); 10406 return true; 10407 } 10408 10409 bool IsCPUSpecificCPUDispatchMVType = 10410 MVType == MultiVersionKind::CPUDispatch || 10411 MVType == MultiVersionKind::CPUSpecific; 10412 10413 if (CausesMV && OldFD && 10414 checkNonMultiVersionCompatAttributes(S, OldFD, NewFD, MVType)) 10415 return true; 10416 10417 if (checkNonMultiVersionCompatAttributes(S, NewFD, nullptr, MVType)) 10418 return true; 10419 10420 // Only allow transition to MultiVersion if it hasn't been used. 10421 if (OldFD && CausesMV && OldFD->isUsed(false)) 10422 return S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used); 10423 10424 return S.areMultiversionVariantFunctionsCompatible( 10425 OldFD, NewFD, S.PDiag(diag::err_multiversion_noproto), 10426 PartialDiagnosticAt(NewFD->getLocation(), 10427 S.PDiag(diag::note_multiversioning_caused_here)), 10428 PartialDiagnosticAt(NewFD->getLocation(), 10429 S.PDiag(diag::err_multiversion_doesnt_support) 10430 << IsCPUSpecificCPUDispatchMVType), 10431 PartialDiagnosticAt(NewFD->getLocation(), 10432 S.PDiag(diag::err_multiversion_diff)), 10433 /*TemplatesSupported=*/false, 10434 /*ConstexprSupported=*/!IsCPUSpecificCPUDispatchMVType, 10435 /*CLinkageMayDiffer=*/false); 10436} 10437 10438/// Check the validity of a multiversion function declaration that is the 10439/// first of its kind. Also sets the multiversion'ness' of the function itself. 10440/// 10441/// This sets NewFD->isInvalidDecl() to true if there was an error. 10442/// 10443/// Returns true if there was an error, false otherwise. 10444static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD, 10445 MultiVersionKind MVType, 10446 const TargetAttr *TA) { 10447 assert(MVType != MultiVersionKind::None &&((void)0) 10448 "Function lacks multiversion attribute")((void)0); 10449 10450 // Target only causes MV if it is default, otherwise this is a normal 10451 // function. 10452 if (MVType == MultiVersionKind::Target && !TA->isDefaultVersion()) 10453 return false; 10454 10455 if (MVType == MultiVersionKind::Target && CheckMultiVersionValue(S, FD)) { 10456 FD->setInvalidDecl(); 10457 return true; 10458 } 10459 10460 if (CheckMultiVersionAdditionalRules(S, nullptr, FD, true, MVType)) { 10461 FD->setInvalidDecl(); 10462 return true; 10463 } 10464 10465 FD->setIsMultiVersion(); 10466 return false; 10467} 10468 10469static bool PreviousDeclsHaveMultiVersionAttribute(const FunctionDecl *FD) { 10470 for (const Decl *D = FD->getPreviousDecl(); D; D = D->getPreviousDecl()) { 10471 if (D->getAsFunction()->getMultiVersionKind() != MultiVersionKind::None) 10472 return true; 10473 } 10474 10475 return false; 10476} 10477 10478static bool CheckTargetCausesMultiVersioning( 10479 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, const TargetAttr *NewTA, 10480 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious, 10481 LookupResult &Previous) { 10482 const auto *OldTA = OldFD->getAttr<TargetAttr>(); 10483 ParsedTargetAttr NewParsed = NewTA->parse(); 10484 // Sort order doesn't matter, it just needs to be consistent. 10485 llvm::sort(NewParsed.Features); 10486 10487 // If the old decl is NOT MultiVersioned yet, and we don't cause that 10488 // to change, this is a simple redeclaration. 10489 if (!NewTA->isDefaultVersion() && 10490 (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr())) 10491 return false; 10492 10493 // Otherwise, this decl causes MultiVersioning. 10494 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) { 10495 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported); 10496 S.Diag(OldFD->getLocation(), diag::note_previous_declaration); 10497 NewFD->setInvalidDecl(); 10498 return true; 10499 } 10500 10501 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true, 10502 MultiVersionKind::Target)) { 10503 NewFD->setInvalidDecl(); 10504 return true; 10505 } 10506 10507 if (CheckMultiVersionValue(S, NewFD)) { 10508 NewFD->setInvalidDecl(); 10509 return true; 10510 } 10511 10512 // If this is 'default', permit the forward declaration. 10513 if (!OldFD->isMultiVersion() && !OldTA && NewTA->isDefaultVersion()) { 10514 Redeclaration = true; 10515 OldDecl = OldFD; 10516 OldFD->setIsMultiVersion(); 10517 NewFD->setIsMultiVersion(); 10518 return false; 10519 } 10520 10521 if (CheckMultiVersionValue(S, OldFD)) { 10522 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); 10523 NewFD->setInvalidDecl(); 10524 return true; 10525 } 10526 10527 ParsedTargetAttr OldParsed = OldTA->parse(std::less<std::string>()); 10528 10529 if (OldParsed == NewParsed) { 10530 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate); 10531 S.Diag(OldFD->getLocation(), diag::note_previous_declaration); 10532 NewFD->setInvalidDecl(); 10533 return true; 10534 } 10535 10536 for (const auto *FD : OldFD->redecls()) { 10537 const auto *CurTA = FD->getAttr<TargetAttr>(); 10538 // We allow forward declarations before ANY multiversioning attributes, but 10539 // nothing after the fact. 10540 if (PreviousDeclsHaveMultiVersionAttribute(FD) && 10541 (!CurTA || CurTA->isInherited())) { 10542 S.Diag(FD->getLocation(), diag::err_multiversion_required_in_redecl) 10543 << 0; 10544 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here); 10545 NewFD->setInvalidDecl(); 10546 return true; 10547 } 10548 } 10549 10550 OldFD->setIsMultiVersion(); 10551 NewFD->setIsMultiVersion(); 10552 Redeclaration = false; 10553 MergeTypeWithPrevious = false; 10554 OldDecl = nullptr; 10555 Previous.clear(); 10556 return false; 10557} 10558 10559/// Check the validity of a new function declaration being added to an existing 10560/// multiversioned declaration collection. 10561static bool CheckMultiVersionAdditionalDecl( 10562 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, 10563 MultiVersionKind NewMVType, const TargetAttr *NewTA, 10564 const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec, 10565 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious, 10566 LookupResult &Previous) { 10567 10568 MultiVersionKind OldMVType = OldFD->getMultiVersionKind(); 10569 // Disallow mixing of multiversioning types. 10570 if ((OldMVType == MultiVersionKind::Target && 10571 NewMVType != MultiVersionKind::Target) || 10572 (NewMVType == MultiVersionKind::Target && 10573 OldMVType != MultiVersionKind::Target)) { 10574 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed); 10575 S.Diag(OldFD->getLocation(), diag::note_previous_declaration); 10576 NewFD->setInvalidDecl(); 10577 return true; 10578 } 10579 10580 ParsedTargetAttr NewParsed; 10581 if (NewTA) { 10582 NewParsed = NewTA->parse(); 10583 llvm::sort(NewParsed.Features); 10584 } 10585 10586 bool UseMemberUsingDeclRules = 10587 S.CurContext->isRecord() && !NewFD->getFriendObjectKind(); 10588 10589 // Next, check ALL non-overloads to see if this is a redeclaration of a 10590 // previous member of the MultiVersion set. 10591 for (NamedDecl *ND : Previous) { 10592 FunctionDecl *CurFD = ND->getAsFunction(); 10593 if (!CurFD) 10594 continue; 10595 if (S.IsOverload(NewFD, CurFD, UseMemberUsingDeclRules)) 10596 continue; 10597 10598 if (NewMVType == MultiVersionKind::Target) { 10599 const auto *CurTA = CurFD->getAttr<TargetAttr>(); 10600 if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) { 10601 NewFD->setIsMultiVersion(); 10602 Redeclaration = true; 10603 OldDecl = ND; 10604 return false; 10605 } 10606 10607 ParsedTargetAttr CurParsed = CurTA->parse(std::less<std::string>()); 10608 if (CurParsed == NewParsed) { 10609 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate); 10610 S.Diag(CurFD->getLocation(), diag::note_previous_declaration); 10611 NewFD->setInvalidDecl(); 10612 return true; 10613 } 10614 } else { 10615 const auto *CurCPUSpec = CurFD->getAttr<CPUSpecificAttr>(); 10616 const auto *CurCPUDisp = CurFD->getAttr<CPUDispatchAttr>(); 10617 // Handle CPUDispatch/CPUSpecific versions. 10618 // Only 1 CPUDispatch function is allowed, this will make it go through 10619 // the redeclaration errors. 10620 if (NewMVType == MultiVersionKind::CPUDispatch && 10621 CurFD->hasAttr<CPUDispatchAttr>()) { 10622 if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() && 10623 std::equal( 10624 CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(), 10625 NewCPUDisp->cpus_begin(), 10626 [](const IdentifierInfo *Cur, const IdentifierInfo *New) { 10627 return Cur->getName() == New->getName(); 10628 })) { 10629 NewFD->setIsMultiVersion(); 10630 Redeclaration = true; 10631 OldDecl = ND; 10632 return false; 10633 } 10634 10635 // If the declarations don't match, this is an error condition. 10636 S.Diag(NewFD->getLocation(), diag::err_cpu_dispatch_mismatch); 10637 S.Diag(CurFD->getLocation(), diag::note_previous_declaration); 10638 NewFD->setInvalidDecl(); 10639 return true; 10640 } 10641 if (NewMVType == MultiVersionKind::CPUSpecific && CurCPUSpec) { 10642 10643 if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() && 10644 std::equal( 10645 CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(), 10646 NewCPUSpec->cpus_begin(), 10647 [](const IdentifierInfo *Cur, const IdentifierInfo *New) { 10648 return Cur->getName() == New->getName(); 10649 })) { 10650 NewFD->setIsMultiVersion(); 10651 Redeclaration = true; 10652 OldDecl = ND; 10653 return false; 10654 } 10655 10656 // Only 1 version of CPUSpecific is allowed for each CPU. 10657 for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) { 10658 for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) { 10659 if (CurII == NewII) { 10660 S.Diag(NewFD->getLocation(), diag::err_cpu_specific_multiple_defs) 10661 << NewII; 10662 S.Diag(CurFD->getLocation(), diag::note_previous_declaration); 10663 NewFD->setInvalidDecl(); 10664 return true; 10665 } 10666 } 10667 } 10668 } 10669 // If the two decls aren't the same MVType, there is no possible error 10670 // condition. 10671 } 10672 } 10673 10674 // Else, this is simply a non-redecl case. Checking the 'value' is only 10675 // necessary in the Target case, since The CPUSpecific/Dispatch cases are 10676 // handled in the attribute adding step. 10677 if (NewMVType == MultiVersionKind::Target && 10678 CheckMultiVersionValue(S, NewFD)) { 10679 NewFD->setInvalidDecl(); 10680 return true; 10681 } 10682 10683 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, 10684 !OldFD->isMultiVersion(), NewMVType)) { 10685 NewFD->setInvalidDecl(); 10686 return true; 10687 } 10688 10689 // Permit forward declarations in the case where these two are compatible. 10690 if (!OldFD->isMultiVersion()) { 10691 OldFD->setIsMultiVersion(); 10692 NewFD->setIsMultiVersion(); 10693 Redeclaration = true; 10694 OldDecl = OldFD; 10695 return false; 10696 } 10697 10698 NewFD->setIsMultiVersion(); 10699 Redeclaration = false; 10700 MergeTypeWithPrevious = false; 10701 OldDecl = nullptr; 10702 Previous.clear(); 10703 return false; 10704} 10705 10706 10707/// Check the validity of a mulitversion function declaration. 10708/// Also sets the multiversion'ness' of the function itself. 10709/// 10710/// This sets NewFD->isInvalidDecl() to true if there was an error. 10711/// 10712/// Returns true if there was an error, false otherwise. 10713static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD, 10714 bool &Redeclaration, NamedDecl *&OldDecl, 10715 bool &MergeTypeWithPrevious, 10716 LookupResult &Previous) { 10717 const auto *NewTA = NewFD->getAttr<TargetAttr>(); 10718 const auto *NewCPUDisp = NewFD->getAttr<CPUDispatchAttr>(); 10719 const auto *NewCPUSpec = NewFD->getAttr<CPUSpecificAttr>(); 10720 10721 // Mixing Multiversioning types is prohibited. 10722 if ((NewTA && NewCPUDisp) || (NewTA && NewCPUSpec) || 10723 (NewCPUDisp && NewCPUSpec)) { 10724 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed); 10725 NewFD->setInvalidDecl(); 10726 return true; 10727 } 10728 10729 MultiVersionKind MVType = NewFD->getMultiVersionKind(); 10730 10731 // Main isn't allowed to become a multiversion function, however it IS 10732 // permitted to have 'main' be marked with the 'target' optimization hint. 10733 if (NewFD->isMain()) { 10734 if ((MVType == MultiVersionKind::Target && NewTA->isDefaultVersion()) || 10735 MVType == MultiVersionKind::CPUDispatch || 10736 MVType == MultiVersionKind::CPUSpecific) { 10737 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_allowed_on_main); 10738 NewFD->setInvalidDecl(); 10739 return true; 10740 } 10741 return false; 10742 } 10743 10744 if (!OldDecl || !OldDecl->getAsFunction() || 10745 OldDecl->getDeclContext()->getRedeclContext() != 10746 NewFD->getDeclContext()->getRedeclContext()) { 10747 // If there's no previous declaration, AND this isn't attempting to cause 10748 // multiversioning, this isn't an error condition. 10749 if (MVType == MultiVersionKind::None) 10750 return false; 10751 return CheckMultiVersionFirstFunction(S, NewFD, MVType, NewTA); 10752 } 10753 10754 FunctionDecl *OldFD = OldDecl->getAsFunction(); 10755 10756 if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::None) 10757 return false; 10758 10759 if (OldFD->isMultiVersion() && MVType == MultiVersionKind::None) { 10760 S.Diag(NewFD->getLocation(), diag::err_multiversion_required_in_redecl) 10761 << (OldFD->getMultiVersionKind() != MultiVersionKind::Target); 10762 NewFD->setInvalidDecl(); 10763 return true; 10764 } 10765 10766 // Handle the target potentially causes multiversioning case. 10767 if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::Target) 10768 return CheckTargetCausesMultiVersioning(S, OldFD, NewFD, NewTA, 10769 Redeclaration, OldDecl, 10770 MergeTypeWithPrevious, Previous); 10771 10772 // At this point, we have a multiversion function decl (in OldFD) AND an 10773 // appropriate attribute in the current function decl. Resolve that these are 10774 // still compatible with previous declarations. 10775 return CheckMultiVersionAdditionalDecl( 10776 S, OldFD, NewFD, MVType, NewTA, NewCPUDisp, NewCPUSpec, Redeclaration, 10777 OldDecl, MergeTypeWithPrevious, Previous); 10778} 10779 10780/// Perform semantic checking of a new function declaration. 10781/// 10782/// Performs semantic analysis of the new function declaration 10783/// NewFD. This routine performs all semantic checking that does not 10784/// require the actual declarator involved in the declaration, and is 10785/// used both for the declaration of functions as they are parsed 10786/// (called via ActOnDeclarator) and for the declaration of functions 10787/// that have been instantiated via C++ template instantiation (called 10788/// via InstantiateDecl). 10789/// 10790/// \param IsMemberSpecialization whether this new function declaration is 10791/// a member specialization (that replaces any definition provided by the 10792/// previous declaration). 10793/// 10794/// This sets NewFD->isInvalidDecl() to true if there was an error. 10795/// 10796/// \returns true if the function declaration is a redeclaration. 10797bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD, 10798 LookupResult &Previous, 10799 bool IsMemberSpecialization) { 10800 assert(!NewFD->getReturnType()->isVariablyModifiedType() &&((void)0) 10801 "Variably modified return types are not handled here")((void)0); 10802 10803 // Determine whether the type of this function should be merged with 10804 // a previous visible declaration. This never happens for functions in C++, 10805 // and always happens in C if the previous declaration was visible. 10806 bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus && 10807 !Previous.isShadowed(); 10808 10809 bool Redeclaration = false; 10810 NamedDecl *OldDecl = nullptr; 10811 bool MayNeedOverloadableChecks = false; 10812 10813 // Merge or overload the declaration with an existing declaration of 10814 // the same name, if appropriate. 10815 if (!Previous.empty()) { 10816 // Determine whether NewFD is an overload of PrevDecl or 10817 // a declaration that requires merging. If it's an overload, 10818 // there's no more work to do here; we'll just add the new 10819 // function to the scope. 10820 if (!AllowOverloadingOfFunction(Previous, Context, NewFD)) { 10821 NamedDecl *Candidate = Previous.getRepresentativeDecl(); 10822 if (shouldLinkPossiblyHiddenDecl(Candidate, NewFD)) { 10823 Redeclaration = true; 10824 OldDecl = Candidate; 10825 } 10826 } else { 10827 MayNeedOverloadableChecks = true; 10828 switch (CheckOverload(S, NewFD, Previous, OldDecl, 10829 /*NewIsUsingDecl*/ false)) { 10830 case Ovl_Match: 10831 Redeclaration = true; 10832 break; 10833 10834 case Ovl_NonFunction: 10835 Redeclaration = true; 10836 break; 10837 10838 case Ovl_Overload: 10839 Redeclaration = false; 10840 break; 10841 } 10842 } 10843 } 10844 10845 // Check for a previous extern "C" declaration with this name. 10846 if (!Redeclaration && 10847 checkForConflictWithNonVisibleExternC(*this, NewFD, Previous)) { 10848 if (!Previous.empty()) { 10849 // This is an extern "C" declaration with the same name as a previous 10850 // declaration, and thus redeclares that entity... 10851 Redeclaration = true; 10852 OldDecl = Previous.getFoundDecl(); 10853 MergeTypeWithPrevious = false; 10854 10855 // ... except in the presence of __attribute__((overloadable)). 10856 if (OldDecl->hasAttr<OverloadableAttr>() || 10857 NewFD->hasAttr<OverloadableAttr>()) { 10858 if (IsOverload(NewFD, cast<FunctionDecl>(OldDecl), false)) { 10859 MayNeedOverloadableChecks = true; 10860 Redeclaration = false; 10861 OldDecl = nullptr; 10862 } 10863 } 10864 } 10865 } 10866 10867 if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl, 10868 MergeTypeWithPrevious, Previous)) 10869 return Redeclaration; 10870 10871 // PPC MMA non-pointer types are not allowed as function return types. 10872 if (Context.getTargetInfo().getTriple().isPPC64() && 10873 CheckPPCMMAType(NewFD->getReturnType(), NewFD->getLocation())) { 10874 NewFD->setInvalidDecl(); 10875 } 10876 10877 // C++11 [dcl.constexpr]p8: 10878 // A constexpr specifier for a non-static member function that is not 10879 // a constructor declares that member function to be const. 10880 // 10881 // This needs to be delayed until we know whether this is an out-of-line 10882 // definition of a static member function. 10883 // 10884 // This rule is not present in C++1y, so we produce a backwards 10885 // compatibility warning whenever it happens in C++11. 10886 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD); 10887 if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() && 10888 !MD->isStatic() && !isa<CXXConstructorDecl>(MD) && 10889 !isa<CXXDestructorDecl>(MD) && !MD->getMethodQualifiers().hasConst()) { 10890 CXXMethodDecl *OldMD = nullptr; 10891 if (OldDecl) 10892 OldMD = dyn_cast_or_null<CXXMethodDecl>(OldDecl->getAsFunction()); 10893 if (!OldMD || !OldMD->isStatic()) { 10894 const FunctionProtoType *FPT = 10895 MD->getType()->castAs<FunctionProtoType>(); 10896 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 10897 EPI.TypeQuals.addConst(); 10898 MD->setType(Context.getFunctionType(FPT->getReturnType(), 10899 FPT->getParamTypes(), EPI)); 10900 10901 // Warn that we did this, if we're not performing template instantiation. 10902 // In that case, we'll have warned already when the template was defined. 10903 if (!inTemplateInstantiation()) { 10904 SourceLocation AddConstLoc; 10905 if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc() 10906 .IgnoreParens().getAs<FunctionTypeLoc>()) 10907 AddConstLoc = getLocForEndOfToken(FTL.getRParenLoc()); 10908 10909 Diag(MD->getLocation(), diag::warn_cxx14_compat_constexpr_not_const) 10910 << FixItHint::CreateInsertion(AddConstLoc, " const"); 10911 } 10912 } 10913 } 10914 10915 if (Redeclaration) { 10916 // NewFD and OldDecl represent declarations that need to be 10917 // merged. 10918 if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious)) { 10919 NewFD->setInvalidDecl(); 10920 return Redeclaration; 10921 } 10922 10923 Previous.clear(); 10924 Previous.addDecl(OldDecl); 10925 10926 if (FunctionTemplateDecl *OldTemplateDecl = 10927 dyn_cast<FunctionTemplateDecl>(OldDecl)) { 10928 auto *OldFD = OldTemplateDecl->getTemplatedDecl(); 10929 FunctionTemplateDecl *NewTemplateDecl 10930 = NewFD->getDescribedFunctionTemplate(); 10931 assert(NewTemplateDecl && "Template/non-template mismatch")((void)0); 10932 10933 // The call to MergeFunctionDecl above may have created some state in 10934 // NewTemplateDecl that needs to be merged with OldTemplateDecl before we 10935 // can add it as a redeclaration. 10936 NewTemplateDecl->mergePrevDecl(OldTemplateDecl); 10937 10938 NewFD->setPreviousDeclaration(OldFD); 10939 if (NewFD->isCXXClassMember()) { 10940 NewFD->setAccess(OldTemplateDecl->getAccess()); 10941 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess()); 10942 } 10943 10944 // If this is an explicit specialization of a member that is a function 10945 // template, mark it as a member specialization. 10946 if (IsMemberSpecialization && 10947 NewTemplateDecl->getInstantiatedFromMemberTemplate()) { 10948 NewTemplateDecl->setMemberSpecialization(); 10949 assert(OldTemplateDecl->isMemberSpecialization())((void)0); 10950 // Explicit specializations of a member template do not inherit deleted 10951 // status from the parent member template that they are specializing. 10952 if (OldFD->isDeleted()) { 10953 // FIXME: This assert will not hold in the presence of modules. 10954 assert(OldFD->getCanonicalDecl() == OldFD)((void)0); 10955 // FIXME: We need an update record for this AST mutation. 10956 OldFD->setDeletedAsWritten(false); 10957 } 10958 } 10959 10960 } else { 10961 if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) { 10962 auto *OldFD = cast<FunctionDecl>(OldDecl); 10963 // This needs to happen first so that 'inline' propagates. 10964 NewFD->setPreviousDeclaration(OldFD); 10965 if (NewFD->isCXXClassMember()) 10966 NewFD->setAccess(OldFD->getAccess()); 10967 } 10968 } 10969 } else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks && 10970 !NewFD->getAttr<OverloadableAttr>()) { 10971 assert((Previous.empty() ||((void)0) 10972 llvm::any_of(Previous,((void)0) 10973 [](const NamedDecl *ND) {((void)0) 10974 return ND->hasAttr<OverloadableAttr>();((void)0) 10975 })) &&((void)0) 10976 "Non-redecls shouldn't happen without overloadable present")((void)0); 10977 10978 auto OtherUnmarkedIter = llvm::find_if(Previous, [](const NamedDecl *ND) { 10979 const auto *FD = dyn_cast<FunctionDecl>(ND); 10980 return FD && !FD->hasAttr<OverloadableAttr>(); 10981 }); 10982 10983 if (OtherUnmarkedIter != Previous.end()) { 10984 Diag(NewFD->getLocation(), 10985 diag::err_attribute_overloadable_multiple_unmarked_overloads); 10986 Diag((*OtherUnmarkedIter)->getLocation(), 10987 diag::note_attribute_overloadable_prev_overload) 10988 << false; 10989 10990 NewFD->addAttr(OverloadableAttr::CreateImplicit(Context)); 10991 } 10992 } 10993 10994 if (LangOpts.OpenMP) 10995 ActOnFinishedFunctionDefinitionInOpenMPAssumeScope(NewFD); 10996 10997 // Semantic checking for this function declaration (in isolation). 10998 10999 if (getLangOpts().CPlusPlus) { 11000 // C++-specific checks. 11001 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) { 11002 CheckConstructor(Constructor); 11003 } else if (CXXDestructorDecl *Destructor = 11004 dyn_cast<CXXDestructorDecl>(NewFD)) { 11005 CXXRecordDecl *Record = Destructor->getParent(); 11006 QualType ClassType = Context.getTypeDeclType(Record); 11007 11008 // FIXME: Shouldn't we be able to perform this check even when the class 11009 // type is dependent? Both gcc and edg can handle that. 11010 if (!ClassType->isDependentType()) { 11011 DeclarationName Name 11012 = Context.DeclarationNames.getCXXDestructorName( 11013 Context.getCanonicalType(ClassType)); 11014 if (NewFD->getDeclName() != Name) { 11015 Diag(NewFD->getLocation(), diag::err_destructor_name); 11016 NewFD->setInvalidDecl(); 11017 return Redeclaration; 11018 } 11019 } 11020 } else if (auto *Guide = dyn_cast<CXXDeductionGuideDecl>(NewFD)) { 11021 if (auto *TD = Guide->getDescribedFunctionTemplate()) 11022 CheckDeductionGuideTemplate(TD); 11023 11024 // A deduction guide is not on the list of entities that can be 11025 // explicitly specialized. 11026 if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) 11027 Diag(Guide->getBeginLoc(), diag::err_deduction_guide_specialized) 11028 << /*explicit specialization*/ 1; 11029 } 11030 11031 // Find any virtual functions that this function overrides. 11032 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) { 11033 if (!Method->isFunctionTemplateSpecialization() && 11034 !Method->getDescribedFunctionTemplate() && 11035 Method->isCanonicalDecl()) { 11036 AddOverriddenMethods(Method->getParent(), Method); 11037 } 11038 if (Method->isVirtual() && NewFD->getTrailingRequiresClause()) 11039 // C++2a [class.virtual]p6 11040 // A virtual method shall not have a requires-clause. 11041 Diag(NewFD->getTrailingRequiresClause()->getBeginLoc(), 11042 diag::err_constrained_virtual_method); 11043 11044 if (Method->isStatic()) 11045 checkThisInStaticMemberFunctionType(Method); 11046 } 11047 11048 if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(NewFD)) 11049 ActOnConversionDeclarator(Conversion); 11050 11051 // Extra checking for C++ overloaded operators (C++ [over.oper]). 11052 if (NewFD->isOverloadedOperator() && 11053 CheckOverloadedOperatorDeclaration(NewFD)) { 11054 NewFD->setInvalidDecl(); 11055 return Redeclaration; 11056 } 11057 11058 // Extra checking for C++0x literal operators (C++0x [over.literal]). 11059 if (NewFD->getLiteralIdentifier() && 11060 CheckLiteralOperatorDeclaration(NewFD)) { 11061 NewFD->setInvalidDecl(); 11062 return Redeclaration; 11063 } 11064 11065 // In C++, check default arguments now that we have merged decls. Unless 11066 // the lexical context is the class, because in this case this is done 11067 // during delayed parsing anyway. 11068 if (!CurContext->isRecord()) 11069 CheckCXXDefaultArguments(NewFD); 11070 11071 // If this function is declared as being extern "C", then check to see if 11072 // the function returns a UDT (class, struct, or union type) that is not C 11073 // compatible, and if it does, warn the user. 11074 // But, issue any diagnostic on the first declaration only. 11075 if (Previous.empty() && NewFD->isExternC()) { 11076 QualType R = NewFD->getReturnType(); 11077 if (R->isIncompleteType() && !R->isVoidType()) 11078 Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete) 11079 << NewFD << R; 11080 else if (!R.isPODType(Context) && !R->isVoidType() && 11081 !R->isObjCObjectPointerType()) 11082 Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R; 11083 } 11084 11085 // C++1z [dcl.fct]p6: 11086 // [...] whether the function has a non-throwing exception-specification 11087 // [is] part of the function type 11088 // 11089 // This results in an ABI break between C++14 and C++17 for functions whose 11090 // declared type includes an exception-specification in a parameter or 11091 // return type. (Exception specifications on the function itself are OK in 11092 // most cases, and exception specifications are not permitted in most other 11093 // contexts where they could make it into a mangling.) 11094 if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) { 11095 auto HasNoexcept = [&](QualType T) -> bool { 11096 // Strip off declarator chunks that could be between us and a function 11097 // type. We don't need to look far, exception specifications are very 11098 // restricted prior to C++17. 11099 if (auto *RT = T->getAs<ReferenceType>()) 11100 T = RT->getPointeeType(); 11101 else if (T->isAnyPointerType()) 11102 T = T->getPointeeType(); 11103 else if (auto *MPT = T->getAs<MemberPointerType>()) 11104 T = MPT->getPointeeType(); 11105 if (auto *FPT = T->getAs<FunctionProtoType>()) 11106 if (FPT->isNothrow()) 11107 return true; 11108 return false; 11109 }; 11110 11111 auto *FPT = NewFD->getType()->castAs<FunctionProtoType>(); 11112 bool AnyNoexcept = HasNoexcept(FPT->getReturnType()); 11113 for (QualType T : FPT->param_types()) 11114 AnyNoexcept |= HasNoexcept(T); 11115 if (AnyNoexcept) 11116 Diag(NewFD->getLocation(), 11117 diag::warn_cxx17_compat_exception_spec_in_signature) 11118 << NewFD; 11119 } 11120 11121 if (!Redeclaration && LangOpts.CUDA) 11122 checkCUDATargetOverload(NewFD, Previous); 11123 } 11124 return Redeclaration; 11125} 11126 11127void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) { 11128 // C++11 [basic.start.main]p3: 11129 // A program that [...] declares main to be inline, static or 11130 // constexpr is ill-formed. 11131 // C11 6.7.4p4: In a hosted environment, no function specifier(s) shall 11132 // appear in a declaration of main. 11133 // static main is not an error under C99, but we should warn about it. 11134 // We accept _Noreturn main as an extension. 11135 if (FD->getStorageClass() == SC_Static) 11136 Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus 11137 ? diag::err_static_main : diag::warn_static_main) 11138 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); 11139 if (FD->isInlineSpecified()) 11140 Diag(DS.getInlineSpecLoc(), diag::err_inline_main) 11141 << FixItHint::CreateRemoval(DS.getInlineSpecLoc()); 11142 if (DS.isNoreturnSpecified()) { 11143 SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc(); 11144 SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(NoreturnLoc)); 11145 Diag(NoreturnLoc, diag::ext_noreturn_main); 11146 Diag(NoreturnLoc, diag::note_main_remove_noreturn) 11147 << FixItHint::CreateRemoval(NoreturnRange); 11148 } 11149 if (FD->isConstexpr()) { 11150 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main) 11151 << FD->isConsteval() 11152 << FixItHint::CreateRemoval(DS.getConstexprSpecLoc()); 11153 FD->setConstexprKind(ConstexprSpecKind::Unspecified); 11154 } 11155 11156 if (getLangOpts().OpenCL) { 11157 Diag(FD->getLocation(), diag::err_opencl_no_main) 11158 << FD->hasAttr<OpenCLKernelAttr>(); 11159 FD->setInvalidDecl(); 11160 return; 11161 } 11162 11163 QualType T = FD->getType(); 11164 assert(T->isFunctionType() && "function decl is not of function type")((void)0); 11165 const FunctionType* FT = T->castAs<FunctionType>(); 11166 11167 // Set default calling convention for main() 11168 if (FT->getCallConv() != CC_C) { 11169 FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(CC_C)); 11170 FD->setType(QualType(FT, 0)); 11171 T = Context.getCanonicalType(FD->getType()); 11172 } 11173 11174 if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) { 11175 // In C with GNU extensions we allow main() to have non-integer return 11176 // type, but we should warn about the extension, and we disable the 11177 // implicit-return-zero rule. 11178 11179 // GCC in C mode accepts qualified 'int'. 11180 if (Context.hasSameUnqualifiedType(FT->getReturnType(), Context.IntTy)) 11181 FD->setHasImplicitReturnZero(true); 11182 else { 11183 Diag(FD->getTypeSpecStartLoc(), diag::ext_main_returns_nonint); 11184 SourceRange RTRange = FD->getReturnTypeSourceRange(); 11185 if (RTRange.isValid()) 11186 Diag(RTRange.getBegin(), diag::note_main_change_return_type) 11187 << FixItHint::CreateReplacement(RTRange, "int"); 11188 } 11189 } else { 11190 // In C and C++, main magically returns 0 if you fall off the end; 11191 // set the flag which tells us that. 11192 // This is C++ [basic.start.main]p5 and C99 5.1.2.2.3. 11193 11194 // All the standards say that main() should return 'int'. 11195 if (Context.hasSameType(FT->getReturnType(), Context.IntTy)) 11196 FD->setHasImplicitReturnZero(true); 11197 else { 11198 // Otherwise, this is just a flat-out error. 11199 SourceRange RTRange = FD->getReturnTypeSourceRange(); 11200 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint) 11201 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "int") 11202 : FixItHint()); 11203 FD->setInvalidDecl(true); 11204 } 11205 } 11206 11207 // Treat protoless main() as nullary. 11208 if (isa<FunctionNoProtoType>(FT)) return; 11209 11210 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT); 11211 unsigned nparams = FTP->getNumParams(); 11212 assert(FD->getNumParams() == nparams)((void)0); 11213 11214 bool HasExtraParameters = (nparams > 3); 11215 11216 if (FTP->isVariadic()) { 11217 Diag(FD->getLocation(), diag::ext_variadic_main); 11218 // FIXME: if we had information about the location of the ellipsis, we 11219 // could add a FixIt hint to remove it as a parameter. 11220 } 11221 11222 // Darwin passes an undocumented fourth argument of type char**. If 11223 // other platforms start sprouting these, the logic below will start 11224 // getting shifty. 11225 if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin()) 11226 HasExtraParameters = false; 11227 11228 if (HasExtraParameters) { 11229 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams; 11230 FD->setInvalidDecl(true); 11231 nparams = 3; 11232 } 11233 11234 // FIXME: a lot of the following diagnostics would be improved 11235 // if we had some location information about types. 11236 11237 QualType CharPP = 11238 Context.getPointerType(Context.getPointerType(Context.CharTy)); 11239 QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP }; 11240 11241 for (unsigned i = 0; i < nparams; ++i) { 11242 QualType AT = FTP->getParamType(i); 11243 11244 bool mismatch = true; 11245 11246 if (Context.hasSameUnqualifiedType(AT, Expected[i])) 11247 mismatch = false; 11248 else if (Expected[i] == CharPP) { 11249 // As an extension, the following forms are okay: 11250 // char const ** 11251 // char const * const * 11252 // char * const * 11253 11254 QualifierCollector qs; 11255 const PointerType* PT; 11256 if ((PT = qs.strip(AT)->getAs<PointerType>()) && 11257 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) && 11258 Context.hasSameType(QualType(qs.strip(PT->getPointeeType()), 0), 11259 Context.CharTy)) { 11260 qs.removeConst(); 11261 mismatch = !qs.empty(); 11262 } 11263 } 11264 11265 if (mismatch) { 11266 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i]; 11267 // TODO: suggest replacing given type with expected type 11268 FD->setInvalidDecl(true); 11269 } 11270 } 11271 11272 if (nparams == 1 && !FD->isInvalidDecl()) { 11273 Diag(FD->getLocation(), diag::warn_main_one_arg); 11274 } 11275 11276 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) { 11277 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD; 11278 FD->setInvalidDecl(); 11279 } 11280} 11281 11282static bool isDefaultStdCall(FunctionDecl *FD, Sema &S) { 11283 11284 // Default calling convention for main and wmain is __cdecl 11285 if (FD->getName() == "main" || FD->getName() == "wmain") 11286 return false; 11287 11288 // Default calling convention for MinGW is __cdecl 11289 const llvm::Triple &T = S.Context.getTargetInfo().getTriple(); 11290 if (T.isWindowsGNUEnvironment()) 11291 return false; 11292 11293 // Default calling convention for WinMain, wWinMain and DllMain 11294 // is __stdcall on 32 bit Windows 11295 if (T.isOSWindows() && T.getArch() == llvm::Triple::x86) 11296 return true; 11297 11298 return false; 11299} 11300 11301void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) { 11302 QualType T = FD->getType(); 11303 assert(T->isFunctionType() && "function decl is not of function type")((void)0); 11304 const FunctionType *FT = T->castAs<FunctionType>(); 11305 11306 // Set an implicit return of 'zero' if the function can return some integral, 11307 // enumeration, pointer or nullptr type. 11308 if (FT->getReturnType()->isIntegralOrEnumerationType() || 11309 FT->getReturnType()->isAnyPointerType() || 11310 FT->getReturnType()->isNullPtrType()) 11311 // DllMain is exempt because a return value of zero means it failed. 11312 if (FD->getName() != "DllMain") 11313 FD->setHasImplicitReturnZero(true); 11314 11315 // Explicity specified calling conventions are applied to MSVC entry points 11316 if (!hasExplicitCallingConv(T)) { 11317 if (isDefaultStdCall(FD, *this)) { 11318 if (FT->getCallConv() != CC_X86StdCall) { 11319 FT = Context.adjustFunctionType( 11320 FT, FT->getExtInfo().withCallingConv(CC_X86StdCall)); 11321 FD->setType(QualType(FT, 0)); 11322 } 11323 } else if (FT->getCallConv() != CC_C) { 11324 FT = Context.adjustFunctionType(FT, 11325 FT->getExtInfo().withCallingConv(CC_C)); 11326 FD->setType(QualType(FT, 0)); 11327 } 11328 } 11329 11330 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) { 11331 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD; 11332 FD->setInvalidDecl(); 11333 } 11334} 11335 11336bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) { 11337 // FIXME: Need strict checking. In C89, we need to check for 11338 // any assignment, increment, decrement, function-calls, or 11339 // commas outside of a sizeof. In C99, it's the same list, 11340 // except that the aforementioned are allowed in unevaluated 11341 // expressions. Everything else falls under the 11342 // "may accept other forms of constant expressions" exception. 11343 // 11344 // Regular C++ code will not end up here (exceptions: language extensions, 11345 // OpenCL C++ etc), so the constant expression rules there don't matter. 11346 if (Init->isValueDependent()) { 11347 assert(Init->containsErrors() &&((void)0) 11348 "Dependent code should only occur in error-recovery path.")((void)0); 11349 return true; 11350 } 11351 const Expr *Culprit; 11352 if (Init->isConstantInitializer(Context, false, &Culprit)) 11353 return false; 11354 Diag(Culprit->getExprLoc(), diag::err_init_element_not_constant) 11355 << Culprit->getSourceRange(); 11356 return true; 11357} 11358 11359namespace { 11360 // Visits an initialization expression to see if OrigDecl is evaluated in 11361 // its own initialization and throws a warning if it does. 11362 class SelfReferenceChecker 11363 : public EvaluatedExprVisitor<SelfReferenceChecker> { 11364 Sema &S; 11365 Decl *OrigDecl; 11366 bool isRecordType; 11367 bool isPODType; 11368 bool isReferenceType; 11369 11370 bool isInitList; 11371 llvm::SmallVector<unsigned, 4> InitFieldIndex; 11372 11373 public: 11374 typedef EvaluatedExprVisitor<SelfReferenceChecker> Inherited; 11375 11376 SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context), 11377 S(S), OrigDecl(OrigDecl) { 11378 isPODType = false; 11379 isRecordType = false; 11380 isReferenceType = false; 11381 isInitList = false; 11382 if (ValueDecl *VD = dyn_cast<ValueDecl>(OrigDecl)) { 11383 isPODType = VD->getType().isPODType(S.Context); 11384 isRecordType = VD->getType()->isRecordType(); 11385 isReferenceType = VD->getType()->isReferenceType(); 11386 } 11387 } 11388 11389 // For most expressions, just call the visitor. For initializer lists, 11390 // track the index of the field being initialized since fields are 11391 // initialized in order allowing use of previously initialized fields. 11392 void CheckExpr(Expr *E) { 11393 InitListExpr *InitList = dyn_cast<InitListExpr>(E); 11394 if (!InitList) { 11395 Visit(E); 11396 return; 11397 } 11398 11399 // Track and increment the index here. 11400 isInitList = true; 11401 InitFieldIndex.push_back(0); 11402 for (auto Child : InitList->children()) { 11403 CheckExpr(cast<Expr>(Child)); 11404 ++InitFieldIndex.back(); 11405 } 11406 InitFieldIndex.pop_back(); 11407 } 11408 11409 // Returns true if MemberExpr is checked and no further checking is needed. 11410 // Returns false if additional checking is required. 11411 bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) { 11412 llvm::SmallVector<FieldDecl*, 4> Fields; 11413 Expr *Base = E; 11414 bool ReferenceField = false; 11415 11416 // Get the field members used. 11417 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) { 11418 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()); 11419 if (!FD) 11420 return false; 11421 Fields.push_back(FD); 11422 if (FD->getType()->isReferenceType()) 11423 ReferenceField = true; 11424 Base = ME->getBase()->IgnoreParenImpCasts(); 11425 } 11426 11427 // Keep checking only if the base Decl is the same. 11428 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base); 11429 if (!DRE || DRE->getDecl() != OrigDecl) 11430 return false; 11431 11432 // A reference field can be bound to an unininitialized field. 11433 if (CheckReference && !ReferenceField) 11434 return true; 11435 11436 // Convert FieldDecls to their index number. 11437 llvm::SmallVector<unsigned, 4> UsedFieldIndex; 11438 for (const FieldDecl *I : llvm::reverse(Fields)) 11439 UsedFieldIndex.push_back(I->getFieldIndex()); 11440 11441 // See if a warning is needed by checking the first difference in index 11442 // numbers. If field being used has index less than the field being 11443 // initialized, then the use is safe. 11444 for (auto UsedIter = UsedFieldIndex.begin(), 11445 UsedEnd = UsedFieldIndex.end(), 11446 OrigIter = InitFieldIndex.begin(), 11447 OrigEnd = InitFieldIndex.end(); 11448 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) { 11449 if (*UsedIter < *OrigIter) 11450 return true; 11451 if (*UsedIter > *OrigIter) 11452 break; 11453 } 11454 11455 // TODO: Add a different warning which will print the field names. 11456 HandleDeclRefExpr(DRE); 11457 return true; 11458 } 11459 11460 // For most expressions, the cast is directly above the DeclRefExpr. 11461 // For conditional operators, the cast can be outside the conditional 11462 // operator if both expressions are DeclRefExpr's. 11463 void HandleValue(Expr *E) { 11464 E = E->IgnoreParens(); 11465 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(E)) { 11466 HandleDeclRefExpr(DRE); 11467 return; 11468 } 11469 11470 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { 11471 Visit(CO->getCond()); 11472 HandleValue(CO->getTrueExpr()); 11473 HandleValue(CO->getFalseExpr()); 11474 return; 11475 } 11476 11477 if (BinaryConditionalOperator *BCO = 11478 dyn_cast<BinaryConditionalOperator>(E)) { 11479 Visit(BCO->getCond()); 11480 HandleValue(BCO->getFalseExpr()); 11481 return; 11482 } 11483 11484 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) { 11485 HandleValue(OVE->getSourceExpr()); 11486 return; 11487 } 11488 11489 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) { 11490 if (BO->getOpcode() == BO_Comma) { 11491 Visit(BO->getLHS()); 11492 HandleValue(BO->getRHS()); 11493 return; 11494 } 11495 } 11496 11497 if (isa<MemberExpr>(E)) { 11498 if (isInitList) { 11499 if (CheckInitListMemberExpr(cast<MemberExpr>(E), 11500 false /*CheckReference*/)) 11501 return; 11502 } 11503 11504 Expr *Base = E->IgnoreParenImpCasts(); 11505 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) { 11506 // Check for static member variables and don't warn on them. 11507 if (!isa<FieldDecl>(ME->getMemberDecl())) 11508 return; 11509 Base = ME->getBase()->IgnoreParenImpCasts(); 11510 } 11511 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) 11512 HandleDeclRefExpr(DRE); 11513 return; 11514 } 11515 11516 Visit(E); 11517 } 11518 11519 // Reference types not handled in HandleValue are handled here since all 11520 // uses of references are bad, not just r-value uses. 11521 void VisitDeclRefExpr(DeclRefExpr *E) { 11522 if (isReferenceType) 11523 HandleDeclRefExpr(E); 11524 } 11525 11526 void VisitImplicitCastExpr(ImplicitCastExpr *E) { 11527 if (E->getCastKind() == CK_LValueToRValue) { 11528 HandleValue(E->getSubExpr()); 11529 return; 11530 } 11531 11532 Inherited::VisitImplicitCastExpr(E); 11533 } 11534 11535 void VisitMemberExpr(MemberExpr *E) { 11536 if (isInitList) { 11537 if (CheckInitListMemberExpr(E, true /*CheckReference*/)) 11538 return; 11539 } 11540 11541 // Don't warn on arrays since they can be treated as pointers. 11542 if (E->getType()->canDecayToPointerType()) return; 11543 11544 // Warn when a non-static method call is followed by non-static member 11545 // field accesses, which is followed by a DeclRefExpr. 11546 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl()); 11547 bool Warn = (MD && !MD->isStatic()); 11548 Expr *Base = E->getBase()->IgnoreParenImpCasts(); 11549 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) { 11550 if (!isa<FieldDecl>(ME->getMemberDecl())) 11551 Warn = false; 11552 Base = ME->getBase()->IgnoreParenImpCasts(); 11553 } 11554 11555 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) { 11556 if (Warn) 11557 HandleDeclRefExpr(DRE); 11558 return; 11559 } 11560 11561 // The base of a MemberExpr is not a MemberExpr or a DeclRefExpr. 11562 // Visit that expression. 11563 Visit(Base); 11564 } 11565 11566 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) { 11567 Expr *Callee = E->getCallee(); 11568 11569 if (isa<UnresolvedLookupExpr>(Callee)) 11570 return Inherited::VisitCXXOperatorCallExpr(E); 11571 11572 Visit(Callee); 11573 for (auto Arg: E->arguments()) 11574 HandleValue(Arg->IgnoreParenImpCasts()); 11575 } 11576 11577 void VisitUnaryOperator(UnaryOperator *E) { 11578 // For POD record types, addresses of its own members are well-defined. 11579 if (E->getOpcode() == UO_AddrOf && isRecordType && 11580 isa<MemberExpr>(E->getSubExpr()->IgnoreParens())) { 11581 if (!isPODType) 11582 HandleValue(E->getSubExpr()); 11583 return; 11584 } 11585 11586 if (E->isIncrementDecrementOp()) { 11587 HandleValue(E->getSubExpr()); 11588 return; 11589 } 11590 11591 Inherited::VisitUnaryOperator(E); 11592 } 11593 11594 void VisitObjCMessageExpr(ObjCMessageExpr *E) {} 11595 11596 void VisitCXXConstructExpr(CXXConstructExpr *E) { 11597 if (E->getConstructor()->isCopyConstructor()) { 11598 Expr *ArgExpr = E->getArg(0); 11599 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr)) 11600 if (ILE->getNumInits() == 1) 11601 ArgExpr = ILE->getInit(0); 11602 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr)) 11603 if (ICE->getCastKind() == CK_NoOp) 11604 ArgExpr = ICE->getSubExpr(); 11605 HandleValue(ArgExpr); 11606 return; 11607 } 11608 Inherited::VisitCXXConstructExpr(E); 11609 } 11610 11611 void VisitCallExpr(CallExpr *E) { 11612 // Treat std::move as a use. 11613 if (E->isCallToStdMove()) { 11614 HandleValue(E->getArg(0)); 11615 return; 11616 } 11617 11618 Inherited::VisitCallExpr(E); 11619 } 11620 11621 void VisitBinaryOperator(BinaryOperator *E) { 11622 if (E->isCompoundAssignmentOp()) { 11623 HandleValue(E->getLHS()); 11624 Visit(E->getRHS()); 11625 return; 11626 } 11627 11628 Inherited::VisitBinaryOperator(E); 11629 } 11630 11631 // A custom visitor for BinaryConditionalOperator is needed because the 11632 // regular visitor would check the condition and true expression separately 11633 // but both point to the same place giving duplicate diagnostics. 11634 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { 11635 Visit(E->getCond()); 11636 Visit(E->getFalseExpr()); 11637 } 11638 11639 void HandleDeclRefExpr(DeclRefExpr *DRE) { 11640 Decl* ReferenceDecl = DRE->getDecl(); 11641 if (OrigDecl != ReferenceDecl) return; 11642 unsigned diag; 11643 if (isReferenceType) { 11644 diag = diag::warn_uninit_self_reference_in_reference_init; 11645 } else if (cast<VarDecl>(OrigDecl)->isStaticLocal()) { 11646 diag = diag::warn_static_self_reference_in_init; 11647 } else if (isa<TranslationUnitDecl>(OrigDecl->getDeclContext()) || 11648 isa<NamespaceDecl>(OrigDecl->getDeclContext()) || 11649 DRE->getDecl()->getType()->isRecordType()) { 11650 diag = diag::warn_uninit_self_reference_in_init; 11651 } else { 11652 // Local variables will be handled by the CFG analysis. 11653 return; 11654 } 11655 11656 S.DiagRuntimeBehavior(DRE->getBeginLoc(), DRE, 11657 S.PDiag(diag) 11658 << DRE->getDecl() << OrigDecl->getLocation() 11659 << DRE->getSourceRange()); 11660 } 11661 }; 11662 11663 /// CheckSelfReference - Warns if OrigDecl is used in expression E. 11664 static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E, 11665 bool DirectInit) { 11666 // Parameters arguments are occassionially constructed with itself, 11667 // for instance, in recursive functions. Skip them. 11668 if (isa<ParmVarDecl>(OrigDecl)) 11669 return; 11670 11671 E = E->IgnoreParens(); 11672 11673 // Skip checking T a = a where T is not a record or reference type. 11674 // Doing so is a way to silence uninitialized warnings. 11675 if (!DirectInit && !cast<VarDecl>(OrigDecl)->getType()->isRecordType()) 11676 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) 11677 if (ICE->getCastKind() == CK_LValueToRValue) 11678 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) 11679 if (DRE->getDecl() == OrigDecl) 11680 return; 11681 11682 SelfReferenceChecker(S, OrigDecl).CheckExpr(E); 11683 } 11684} // end anonymous namespace 11685 11686namespace { 11687 // Simple wrapper to add the name of a variable or (if no variable is 11688 // available) a DeclarationName into a diagnostic. 11689 struct VarDeclOrName { 11690 VarDecl *VDecl; 11691 DeclarationName Name; 11692 11693 friend const Sema::SemaDiagnosticBuilder & 11694 operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) { 11695 return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name; 11696 } 11697 }; 11698} // end anonymous namespace 11699 11700QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl, 11701 DeclarationName Name, QualType Type, 11702 TypeSourceInfo *TSI, 11703 SourceRange Range, bool DirectInit, 11704 Expr *Init) { 11705 bool IsInitCapture = !VDecl; 11706 assert((!VDecl || !VDecl->isInitCapture()) &&((void)0) 11707 "init captures are expected to be deduced prior to initialization")((void)0); 11708 11709 VarDeclOrName VN{VDecl, Name}; 11710 11711 DeducedType *Deduced = Type->getContainedDeducedType(); 11712 assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type")((void)0); 11713 11714 // C++11 [dcl.spec.auto]p3 11715 if (!Init) { 11716 assert(VDecl && "no init for init capture deduction?")((void)0); 11717 11718 // Except for class argument deduction, and then for an initializing 11719 // declaration only, i.e. no static at class scope or extern. 11720 if (!isa<DeducedTemplateSpecializationType>(Deduced) || 11721 VDecl->hasExternalStorage() || 11722 VDecl->isStaticDataMember()) { 11723 Diag(VDecl->getLocation(), diag::err_auto_var_requires_init) 11724 << VDecl->getDeclName() << Type; 11725 return QualType(); 11726 } 11727 } 11728 11729 ArrayRef<Expr*> DeduceInits; 11730 if (Init) 11731 DeduceInits = Init; 11732 11733 if (DirectInit) { 11734 if (auto *PL = dyn_cast_or_null<ParenListExpr>(Init)) 11735 DeduceInits = PL->exprs(); 11736 } 11737 11738 if (isa<DeducedTemplateSpecializationType>(Deduced)) { 11739 assert(VDecl && "non-auto type for init capture deduction?")((void)0); 11740 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); 11741 InitializationKind Kind = InitializationKind::CreateForInit( 11742 VDecl->getLocation(), DirectInit, Init); 11743 // FIXME: Initialization should not be taking a mutable list of inits. 11744 SmallVector<Expr*, 8> InitsCopy(DeduceInits.begin(), DeduceInits.end()); 11745 return DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind, 11746 InitsCopy); 11747 } 11748 11749 if (DirectInit) { 11750 if (auto *IL = dyn_cast<InitListExpr>(Init)) 11751 DeduceInits = IL->inits(); 11752 } 11753 11754 // Deduction only works if we have exactly one source expression. 11755 if (DeduceInits.empty()) { 11756 // It isn't possible to write this directly, but it is possible to 11757 // end up in this situation with "auto x(some_pack...);" 11758 Diag(Init->getBeginLoc(), IsInitCapture 11759 ? diag::err_init_capture_no_expression 11760 : diag::err_auto_var_init_no_expression) 11761 << VN << Type << Range; 11762 return QualType(); 11763 } 11764 11765 if (DeduceInits.size() > 1) { 11766 Diag(DeduceInits[1]->getBeginLoc(), 11767 IsInitCapture ? diag::err_init_capture_multiple_expressions 11768 : diag::err_auto_var_init_multiple_expressions) 11769 << VN << Type << Range; 11770 return QualType(); 11771 } 11772 11773 Expr *DeduceInit = DeduceInits[0]; 11774 if (DirectInit && isa<InitListExpr>(DeduceInit)) { 11775 Diag(Init->getBeginLoc(), IsInitCapture 11776 ? diag::err_init_capture_paren_braces 11777 : diag::err_auto_var_init_paren_braces) 11778 << isa<InitListExpr>(Init) << VN << Type << Range; 11779 return QualType(); 11780 } 11781 11782 // Expressions default to 'id' when we're in a debugger. 11783 bool DefaultedAnyToId = false; 11784 if (getLangOpts().DebuggerCastResultToId && 11785 Init->getType() == Context.UnknownAnyTy && !IsInitCapture) { 11786 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType()); 11787 if (Result.isInvalid()) { 11788 return QualType(); 11789 } 11790 Init = Result.get(); 11791 DefaultedAnyToId = true; 11792 } 11793 11794 // C++ [dcl.decomp]p1: 11795 // If the assignment-expression [...] has array type A and no ref-qualifier 11796 // is present, e has type cv A 11797 if (VDecl && isa<DecompositionDecl>(VDecl) && 11798 Context.hasSameUnqualifiedType(Type, Context.getAutoDeductType()) && 11799 DeduceInit->getType()->isConstantArrayType()) 11800 return Context.getQualifiedType(DeduceInit->getType(), 11801 Type.getQualifiers()); 11802 11803 QualType DeducedType; 11804 if (DeduceAutoType(TSI, DeduceInit, DeducedType) == DAR_Failed) { 11805 if (!IsInitCapture) 11806 DiagnoseAutoDeductionFailure(VDecl, DeduceInit); 11807 else if (isa<InitListExpr>(Init)) 11808 Diag(Range.getBegin(), 11809 diag::err_init_capture_deduction_failure_from_init_list) 11810 << VN 11811 << (DeduceInit->getType().isNull() ? TSI->getType() 11812 : DeduceInit->getType()) 11813 << DeduceInit->getSourceRange(); 11814 else 11815 Diag(Range.getBegin(), diag::err_init_capture_deduction_failure) 11816 << VN << TSI->getType() 11817 << (DeduceInit->getType().isNull() ? TSI->getType() 11818 : DeduceInit->getType()) 11819 << DeduceInit->getSourceRange(); 11820 } 11821 11822 // Warn if we deduced 'id'. 'auto' usually implies type-safety, but using 11823 // 'id' instead of a specific object type prevents most of our usual 11824 // checks. 11825 // We only want to warn outside of template instantiations, though: 11826 // inside a template, the 'id' could have come from a parameter. 11827 if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture && 11828 !DeducedType.isNull() && DeducedType->isObjCIdType()) { 11829 SourceLocation Loc = TSI->getTypeLoc().getBeginLoc(); 11830 Diag(Loc, diag::warn_auto_var_is_id) << VN << Range; 11831 } 11832 11833 return DeducedType; 11834} 11835 11836bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit, 11837 Expr *Init) { 11838 assert(!Init || !Init->containsErrors())((void)0); 11839 QualType DeducedType = deduceVarTypeFromInitializer( 11840 VDecl, VDecl->getDeclName(), VDecl->getType(), VDecl->getTypeSourceInfo(), 11841 VDecl->getSourceRange(), DirectInit, Init); 11842 if (DeducedType.isNull()) { 11843 VDecl->setInvalidDecl(); 11844 return true; 11845 } 11846 11847 VDecl->setType(DeducedType); 11848 assert(VDecl->isLinkageValid())((void)0); 11849 11850 // In ARC, infer lifetime. 11851 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(VDecl)) 11852 VDecl->setInvalidDecl(); 11853 11854 if (getLangOpts().OpenCL) 11855 deduceOpenCLAddressSpace(VDecl); 11856 11857 // If this is a redeclaration, check that the type we just deduced matches 11858 // the previously declared type. 11859 if (VarDecl *Old = VDecl->getPreviousDecl()) { 11860 // We never need to merge the type, because we cannot form an incomplete 11861 // array of auto, nor deduce such a type. 11862 MergeVarDeclTypes(VDecl, Old, /*MergeTypeWithPrevious*/ false); 11863 } 11864 11865 // Check the deduced type is valid for a variable declaration. 11866 CheckVariableDeclarationType(VDecl); 11867 return VDecl->isInvalidDecl(); 11868} 11869 11870void Sema::checkNonTrivialCUnionInInitializer(const Expr *Init, 11871 SourceLocation Loc) { 11872 if (auto *EWC = dyn_cast<ExprWithCleanups>(Init)) 11873 Init = EWC->getSubExpr(); 11874 11875 if (auto *CE = dyn_cast<ConstantExpr>(Init)) 11876 Init = CE->getSubExpr(); 11877 11878 QualType InitType = Init->getType(); 11879 assert((InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||((void)0) 11880 InitType.hasNonTrivialToPrimitiveCopyCUnion()) &&((void)0) 11881 "shouldn't be called if type doesn't have a non-trivial C struct")((void)0); 11882 if (auto *ILE = dyn_cast<InitListExpr>(Init)) { 11883 for (auto I : ILE->inits()) { 11884 if (!I->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion() && 11885 !I->getType().hasNonTrivialToPrimitiveCopyCUnion()) 11886 continue; 11887 SourceLocation SL = I->getExprLoc(); 11888 checkNonTrivialCUnionInInitializer(I, SL.isValid() ? SL : Loc); 11889 } 11890 return; 11891 } 11892 11893 if (isa<ImplicitValueInitExpr>(Init)) { 11894 if (InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion()) 11895 checkNonTrivialCUnion(InitType, Loc, NTCUC_DefaultInitializedObject, 11896 NTCUK_Init); 11897 } else { 11898 // Assume all other explicit initializers involving copying some existing 11899 // object. 11900 // TODO: ignore any explicit initializers where we can guarantee 11901 // copy-elision. 11902 if (InitType.hasNonTrivialToPrimitiveCopyCUnion()) 11903 checkNonTrivialCUnion(InitType, Loc, NTCUC_CopyInit, NTCUK_Copy); 11904 } 11905} 11906 11907namespace { 11908 11909bool shouldIgnoreForRecordTriviality(const FieldDecl *FD) { 11910 // Ignore unavailable fields. A field can be marked as unavailable explicitly 11911 // in the source code or implicitly by the compiler if it is in a union 11912 // defined in a system header and has non-trivial ObjC ownership 11913 // qualifications. We don't want those fields to participate in determining 11914 // whether the containing union is non-trivial. 11915 return FD->hasAttr<UnavailableAttr>(); 11916} 11917 11918struct DiagNonTrivalCUnionDefaultInitializeVisitor 11919 : DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor, 11920 void> { 11921 using Super = 11922 DefaultInitializedTypeVisitor<DiagNonTrivalCUnionDefaultInitializeVisitor, 11923 void>; 11924 11925 DiagNonTrivalCUnionDefaultInitializeVisitor( 11926 QualType OrigTy, SourceLocation OrigLoc, 11927 Sema::NonTrivialCUnionContext UseContext, Sema &S) 11928 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {} 11929 11930 void visitWithKind(QualType::PrimitiveDefaultInitializeKind PDIK, QualType QT, 11931 const FieldDecl *FD, bool InNonTrivialUnion) { 11932 if (const auto *AT = S.Context.getAsArrayType(QT)) 11933 return this->asDerived().visit(S.Context.getBaseElementType(AT), FD, 11934 InNonTrivialUnion); 11935 return Super::visitWithKind(PDIK, QT, FD, InNonTrivialUnion); 11936 } 11937 11938 void visitARCStrong(QualType QT, const FieldDecl *FD, 11939 bool InNonTrivialUnion) { 11940 if (InNonTrivialUnion) 11941 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 11942 << 1 << 0 << QT << FD->getName(); 11943 } 11944 11945 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 11946 if (InNonTrivialUnion) 11947 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 11948 << 1 << 0 << QT << FD->getName(); 11949 } 11950 11951 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 11952 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl(); 11953 if (RD->isUnion()) { 11954 if (OrigLoc.isValid()) { 11955 bool IsUnion = false; 11956 if (auto *OrigRD = OrigTy->getAsRecordDecl()) 11957 IsUnion = OrigRD->isUnion(); 11958 S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context) 11959 << 0 << OrigTy << IsUnion << UseContext; 11960 // Reset OrigLoc so that this diagnostic is emitted only once. 11961 OrigLoc = SourceLocation(); 11962 } 11963 InNonTrivialUnion = true; 11964 } 11965 11966 if (InNonTrivialUnion) 11967 S.Diag(RD->getLocation(), diag::note_non_trivial_c_union) 11968 << 0 << 0 << QT.getUnqualifiedType() << ""; 11969 11970 for (const FieldDecl *FD : RD->fields()) 11971 if (!shouldIgnoreForRecordTriviality(FD)) 11972 asDerived().visit(FD->getType(), FD, InNonTrivialUnion); 11973 } 11974 11975 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {} 11976 11977 // The non-trivial C union type or the struct/union type that contains a 11978 // non-trivial C union. 11979 QualType OrigTy; 11980 SourceLocation OrigLoc; 11981 Sema::NonTrivialCUnionContext UseContext; 11982 Sema &S; 11983}; 11984 11985struct DiagNonTrivalCUnionDestructedTypeVisitor 11986 : DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void> { 11987 using Super = 11988 DestructedTypeVisitor<DiagNonTrivalCUnionDestructedTypeVisitor, void>; 11989 11990 DiagNonTrivalCUnionDestructedTypeVisitor( 11991 QualType OrigTy, SourceLocation OrigLoc, 11992 Sema::NonTrivialCUnionContext UseContext, Sema &S) 11993 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {} 11994 11995 void visitWithKind(QualType::DestructionKind DK, QualType QT, 11996 const FieldDecl *FD, bool InNonTrivialUnion) { 11997 if (const auto *AT = S.Context.getAsArrayType(QT)) 11998 return this->asDerived().visit(S.Context.getBaseElementType(AT), FD, 11999 InNonTrivialUnion); 12000 return Super::visitWithKind(DK, QT, FD, InNonTrivialUnion); 12001 } 12002 12003 void visitARCStrong(QualType QT, const FieldDecl *FD, 12004 bool InNonTrivialUnion) { 12005 if (InNonTrivialUnion) 12006 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 12007 << 1 << 1 << QT << FD->getName(); 12008 } 12009 12010 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 12011 if (InNonTrivialUnion) 12012 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 12013 << 1 << 1 << QT << FD->getName(); 12014 } 12015 12016 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 12017 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl(); 12018 if (RD->isUnion()) { 12019 if (OrigLoc.isValid()) { 12020 bool IsUnion = false; 12021 if (auto *OrigRD = OrigTy->getAsRecordDecl()) 12022 IsUnion = OrigRD->isUnion(); 12023 S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context) 12024 << 1 << OrigTy << IsUnion << UseContext; 12025 // Reset OrigLoc so that this diagnostic is emitted only once. 12026 OrigLoc = SourceLocation(); 12027 } 12028 InNonTrivialUnion = true; 12029 } 12030 12031 if (InNonTrivialUnion) 12032 S.Diag(RD->getLocation(), diag::note_non_trivial_c_union) 12033 << 0 << 1 << QT.getUnqualifiedType() << ""; 12034 12035 for (const FieldDecl *FD : RD->fields()) 12036 if (!shouldIgnoreForRecordTriviality(FD)) 12037 asDerived().visit(FD->getType(), FD, InNonTrivialUnion); 12038 } 12039 12040 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {} 12041 void visitCXXDestructor(QualType QT, const FieldDecl *FD, 12042 bool InNonTrivialUnion) {} 12043 12044 // The non-trivial C union type or the struct/union type that contains a 12045 // non-trivial C union. 12046 QualType OrigTy; 12047 SourceLocation OrigLoc; 12048 Sema::NonTrivialCUnionContext UseContext; 12049 Sema &S; 12050}; 12051 12052struct DiagNonTrivalCUnionCopyVisitor 12053 : CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void> { 12054 using Super = CopiedTypeVisitor<DiagNonTrivalCUnionCopyVisitor, false, void>; 12055 12056 DiagNonTrivalCUnionCopyVisitor(QualType OrigTy, SourceLocation OrigLoc, 12057 Sema::NonTrivialCUnionContext UseContext, 12058 Sema &S) 12059 : OrigTy(OrigTy), OrigLoc(OrigLoc), UseContext(UseContext), S(S) {} 12060 12061 void visitWithKind(QualType::PrimitiveCopyKind PCK, QualType QT, 12062 const FieldDecl *FD, bool InNonTrivialUnion) { 12063 if (const auto *AT = S.Context.getAsArrayType(QT)) 12064 return this->asDerived().visit(S.Context.getBaseElementType(AT), FD, 12065 InNonTrivialUnion); 12066 return Super::visitWithKind(PCK, QT, FD, InNonTrivialUnion); 12067 } 12068 12069 void visitARCStrong(QualType QT, const FieldDecl *FD, 12070 bool InNonTrivialUnion) { 12071 if (InNonTrivialUnion) 12072 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 12073 << 1 << 2 << QT << FD->getName(); 12074 } 12075 12076 void visitARCWeak(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 12077 if (InNonTrivialUnion) 12078 S.Diag(FD->getLocation(), diag::note_non_trivial_c_union) 12079 << 1 << 2 << QT << FD->getName(); 12080 } 12081 12082 void visitStruct(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) { 12083 const RecordDecl *RD = QT->castAs<RecordType>()->getDecl(); 12084 if (RD->isUnion()) { 12085 if (OrigLoc.isValid()) { 12086 bool IsUnion = false; 12087 if (auto *OrigRD = OrigTy->getAsRecordDecl()) 12088 IsUnion = OrigRD->isUnion(); 12089 S.Diag(OrigLoc, diag::err_non_trivial_c_union_in_invalid_context) 12090 << 2 << OrigTy << IsUnion << UseContext; 12091 // Reset OrigLoc so that this diagnostic is emitted only once. 12092 OrigLoc = SourceLocation(); 12093 } 12094 InNonTrivialUnion = true; 12095 } 12096 12097 if (InNonTrivialUnion) 12098 S.Diag(RD->getLocation(), diag::note_non_trivial_c_union) 12099 << 0 << 2 << QT.getUnqualifiedType() << ""; 12100 12101 for (const FieldDecl *FD : RD->fields()) 12102 if (!shouldIgnoreForRecordTriviality(FD)) 12103 asDerived().visit(FD->getType(), FD, InNonTrivialUnion); 12104 } 12105 12106 void preVisit(QualType::PrimitiveCopyKind PCK, QualType QT, 12107 const FieldDecl *FD, bool InNonTrivialUnion) {} 12108 void visitTrivial(QualType QT, const FieldDecl *FD, bool InNonTrivialUnion) {} 12109 void visitVolatileTrivial(QualType QT, const FieldDecl *FD, 12110 bool InNonTrivialUnion) {} 12111 12112 // The non-trivial C union type or the struct/union type that contains a 12113 // non-trivial C union. 12114 QualType OrigTy; 12115 SourceLocation OrigLoc; 12116 Sema::NonTrivialCUnionContext UseContext; 12117 Sema &S; 12118}; 12119 12120} // namespace 12121 12122void Sema::checkNonTrivialCUnion(QualType QT, SourceLocation Loc, 12123 NonTrivialCUnionContext UseContext, 12124 unsigned NonTrivialKind) { 12125 assert((QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() ||((void)0) 12126 QT.hasNonTrivialToPrimitiveDestructCUnion() ||((void)0) 12127 QT.hasNonTrivialToPrimitiveCopyCUnion()) &&((void)0) 12128 "shouldn't be called if type doesn't have a non-trivial C union")((void)0); 12129 12130 if ((NonTrivialKind & NTCUK_Init) && 12131 QT.hasNonTrivialToPrimitiveDefaultInitializeCUnion()) 12132 DiagNonTrivalCUnionDefaultInitializeVisitor(QT, Loc, UseContext, *this) 12133 .visit(QT, nullptr, false); 12134 if ((NonTrivialKind & NTCUK_Destruct) && 12135 QT.hasNonTrivialToPrimitiveDestructCUnion()) 12136 DiagNonTrivalCUnionDestructedTypeVisitor(QT, Loc, UseContext, *this) 12137 .visit(QT, nullptr, false); 12138 if ((NonTrivialKind & NTCUK_Copy) && QT.hasNonTrivialToPrimitiveCopyCUnion()) 12139 DiagNonTrivalCUnionCopyVisitor(QT, Loc, UseContext, *this) 12140 .visit(QT, nullptr, false); 12141} 12142 12143/// AddInitializerToDecl - Adds the initializer Init to the 12144/// declaration dcl. If DirectInit is true, this is C++ direct 12145/// initialization rather than copy initialization. 12146void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) { 12147 // If there is no declaration, there was an error parsing it. Just ignore 12148 // the initializer. 12149 if (!RealDecl || RealDecl->isInvalidDecl()) { 12150 CorrectDelayedTyposInExpr(Init, dyn_cast_or_null<VarDecl>(RealDecl)); 12151 return; 12152 } 12153 12154 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) { 12155 // Pure-specifiers are handled in ActOnPureSpecifier. 12156 Diag(Method->getLocation(), diag::err_member_function_initialization) 12157 << Method->getDeclName() << Init->getSourceRange(); 12158 Method->setInvalidDecl(); 12159 return; 12160 } 12161 12162 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl); 12163 if (!VDecl) { 12164 assert(!isa<FieldDecl>(RealDecl) && "field init shouldn't get here")((void)0); 12165 Diag(RealDecl->getLocation(), diag::err_illegal_initializer); 12166 RealDecl->setInvalidDecl(); 12167 return; 12168 } 12169 12170 // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for. 12171 if (VDecl->getType()->isUndeducedType()) { 12172 // Attempt typo correction early so that the type of the init expression can 12173 // be deduced based on the chosen correction if the original init contains a 12174 // TypoExpr. 12175 ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl); 12176 if (!Res.isUsable()) { 12177 // There are unresolved typos in Init, just drop them. 12178 // FIXME: improve the recovery strategy to preserve the Init. 12179 RealDecl->setInvalidDecl(); 12180 return; 12181 } 12182 if (Res.get()->containsErrors()) { 12183 // Invalidate the decl as we don't know the type for recovery-expr yet. 12184 RealDecl->setInvalidDecl(); 12185 VDecl->setInit(Res.get()); 12186 return; 12187 } 12188 Init = Res.get(); 12189 12190 if (DeduceVariableDeclarationType(VDecl, DirectInit, Init)) 12191 return; 12192 } 12193 12194 // dllimport cannot be used on variable definitions. 12195 if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) { 12196 Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition); 12197 VDecl->setInvalidDecl(); 12198 return; 12199 } 12200 12201 if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) { 12202 // C99 6.7.8p5. C++ has no such restriction, but that is a defect. 12203 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init); 12204 VDecl->setInvalidDecl(); 12205 return; 12206 } 12207 12208 if (!VDecl->getType()->isDependentType()) { 12209 // A definition must end up with a complete type, which means it must be 12210 // complete with the restriction that an array type might be completed by 12211 // the initializer; note that later code assumes this restriction. 12212 QualType BaseDeclType = VDecl->getType(); 12213 if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType)) 12214 BaseDeclType = Array->getElementType(); 12215 if (RequireCompleteType(VDecl->getLocation(), BaseDeclType, 12216 diag::err_typecheck_decl_incomplete_type)) { 12217 RealDecl->setInvalidDecl(); 12218 return; 12219 } 12220 12221 // The variable can not have an abstract class type. 12222 if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(), 12223 diag::err_abstract_type_in_decl, 12224 AbstractVariableType)) 12225 VDecl->setInvalidDecl(); 12226 } 12227 12228 // If adding the initializer will turn this declaration into a definition, 12229 // and we already have a definition for this variable, diagnose or otherwise 12230 // handle the situation. 12231 if (VarDecl *Def = VDecl->getDefinition()) 12232 if (Def != VDecl && 12233 (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) && 12234 !VDecl->isThisDeclarationADemotedDefinition() && 12235 checkVarDeclRedefinition(Def, VDecl)) 12236 return; 12237 12238 if (getLangOpts().CPlusPlus) { 12239 // C++ [class.static.data]p4 12240 // If a static data member is of const integral or const 12241 // enumeration type, its declaration in the class definition can 12242 // specify a constant-initializer which shall be an integral 12243 // constant expression (5.19). In that case, the member can appear 12244 // in integral constant expressions. The member shall still be 12245 // defined in a namespace scope if it is used in the program and the 12246 // namespace scope definition shall not contain an initializer. 12247 // 12248 // We already performed a redefinition check above, but for static 12249 // data members we also need to check whether there was an in-class 12250 // declaration with an initializer. 12251 if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) { 12252 Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization) 12253 << VDecl->getDeclName(); 12254 Diag(VDecl->getCanonicalDecl()->getInit()->getExprLoc(), 12255 diag::note_previous_initializer) 12256 << 0; 12257 return; 12258 } 12259 12260 if (VDecl->hasLocalStorage()) 12261 setFunctionHasBranchProtectedScope(); 12262 12263 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) { 12264 VDecl->setInvalidDecl(); 12265 return; 12266 } 12267 } 12268 12269 // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside 12270 // a kernel function cannot be initialized." 12271 if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) { 12272 Diag(VDecl->getLocation(), diag::err_local_cant_init); 12273 VDecl->setInvalidDecl(); 12274 return; 12275 } 12276 12277 // The LoaderUninitialized attribute acts as a definition (of undef). 12278 if (VDecl->hasAttr<LoaderUninitializedAttr>()) { 12279 Diag(VDecl->getLocation(), diag::err_loader_uninitialized_cant_init); 12280 VDecl->setInvalidDecl(); 12281 return; 12282 } 12283 12284 // Get the decls type and save a reference for later, since 12285 // CheckInitializerTypes may change it. 12286 QualType DclT = VDecl->getType(), SavT = DclT; 12287 12288 // Expressions default to 'id' when we're in a debugger 12289 // and we are assigning it to a variable of Objective-C pointer type. 12290 if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() && 12291 Init->getType() == Context.UnknownAnyTy) { 12292 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType()); 12293 if (Result.isInvalid()) { 12294 VDecl->setInvalidDecl(); 12295 return; 12296 } 12297 Init = Result.get(); 12298 } 12299 12300 // Perform the initialization. 12301 ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init); 12302 if (!VDecl->isInvalidDecl()) { 12303 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl); 12304 InitializationKind Kind = InitializationKind::CreateForInit( 12305 VDecl->getLocation(), DirectInit, Init); 12306 12307 MultiExprArg Args = Init; 12308 if (CXXDirectInit) 12309 Args = MultiExprArg(CXXDirectInit->getExprs(), 12310 CXXDirectInit->getNumExprs()); 12311 12312 // Try to correct any TypoExprs in the initialization arguments. 12313 for (size_t Idx = 0; Idx < Args.size(); ++Idx) { 12314 ExprResult Res = CorrectDelayedTyposInExpr( 12315 Args[Idx], VDecl, /*RecoverUncorrectedTypos=*/true, 12316 [this, Entity, Kind](Expr *E) { 12317 InitializationSequence Init(*this, Entity, Kind, MultiExprArg(E)); 12318 return Init.Failed() ? ExprError() : E; 12319 }); 12320 if (Res.isInvalid()) { 12321 VDecl->setInvalidDecl(); 12322 } else if (Res.get() != Args[Idx]) { 12323 Args[Idx] = Res.get(); 12324 } 12325 } 12326 if (VDecl->isInvalidDecl()) 12327 return; 12328 12329 InitializationSequence InitSeq(*this, Entity, Kind, Args, 12330 /*TopLevelOfInitList=*/false, 12331 /*TreatUnavailableAsInvalid=*/false); 12332 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT); 12333 if (Result.isInvalid()) { 12334 // If the provied initializer fails to initialize the var decl, 12335 // we attach a recovery expr for better recovery. 12336 auto RecoveryExpr = 12337 CreateRecoveryExpr(Init->getBeginLoc(), Init->getEndLoc(), Args); 12338 if (RecoveryExpr.get()) 12339 VDecl->setInit(RecoveryExpr.get()); 12340 return; 12341 } 12342 12343 Init = Result.getAs<Expr>(); 12344 } 12345 12346 // Check for self-references within variable initializers. 12347 // Variables declared within a function/method body (except for references) 12348 // are handled by a dataflow analysis. 12349 // This is undefined behavior in C++, but valid in C. 12350 if (getLangOpts().CPlusPlus) 12351 if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() || 12352 VDecl->getType()->isReferenceType()) 12353 CheckSelfReference(*this, RealDecl, Init, DirectInit); 12354 12355 // If the type changed, it means we had an incomplete type that was 12356 // completed by the initializer. For example: 12357 // int ary[] = { 1, 3, 5 }; 12358 // "ary" transitions from an IncompleteArrayType to a ConstantArrayType. 12359 if (!VDecl->isInvalidDecl() && (DclT != SavT)) 12360 VDecl->setType(DclT); 12361 12362 if (!VDecl->isInvalidDecl()) { 12363 checkUnsafeAssigns(VDecl->getLocation(), VDecl->getType(), Init); 12364 12365 if (VDecl->hasAttr<BlocksAttr>()) 12366 checkRetainCycles(VDecl, Init); 12367 12368 // It is safe to assign a weak reference into a strong variable. 12369 // Although this code can still have problems: 12370 // id x = self.weakProp; 12371 // id y = self.weakProp; 12372 // we do not warn to warn spuriously when 'x' and 'y' are on separate 12373 // paths through the function. This should be revisited if 12374 // -Wrepeated-use-of-weak is made flow-sensitive. 12375 if (FunctionScopeInfo *FSI = getCurFunction()) 12376 if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong || 12377 VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) && 12378 !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak, 12379 Init->getBeginLoc())) 12380 FSI->markSafeWeakUse(Init); 12381 } 12382 12383 // The initialization is usually a full-expression. 12384 // 12385 // FIXME: If this is a braced initialization of an aggregate, it is not 12386 // an expression, and each individual field initializer is a separate 12387 // full-expression. For instance, in: 12388 // 12389 // struct Temp { ~Temp(); }; 12390 // struct S { S(Temp); }; 12391 // struct T { S a, b; } t = { Temp(), Temp() } 12392 // 12393 // we should destroy the first Temp before constructing the second. 12394 ExprResult Result = 12395 ActOnFinishFullExpr(Init, VDecl->getLocation(), 12396 /*DiscardedValue*/ false, VDecl->isConstexpr()); 12397 if (Result.isInvalid()) { 12398 VDecl->setInvalidDecl(); 12399 return; 12400 } 12401 Init = Result.get(); 12402 12403 // Attach the initializer to the decl. 12404 VDecl->setInit(Init); 12405 12406 if (VDecl->isLocalVarDecl()) { 12407 // Don't check the initializer if the declaration is malformed. 12408 if (VDecl->isInvalidDecl()) { 12409 // do nothing 12410 12411 // OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized. 12412 // This is true even in C++ for OpenCL. 12413 } else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) { 12414 CheckForConstantInitializer(Init, DclT); 12415 12416 // Otherwise, C++ does not restrict the initializer. 12417 } else if (getLangOpts().CPlusPlus) { 12418 // do nothing 12419 12420 // C99 6.7.8p4: All the expressions in an initializer for an object that has 12421 // static storage duration shall be constant expressions or string literals. 12422 } else if (VDecl->getStorageClass() == SC_Static) { 12423 CheckForConstantInitializer(Init, DclT); 12424 12425 // C89 is stricter than C99 for aggregate initializers. 12426 // C89 6.5.7p3: All the expressions [...] in an initializer list 12427 // for an object that has aggregate or union type shall be 12428 // constant expressions. 12429 } else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() && 12430 isa<InitListExpr>(Init)) { 12431 const Expr *Culprit; 12432 if (!Init->isConstantInitializer(Context, false, &Culprit)) { 12433 Diag(Culprit->getExprLoc(), 12434 diag::ext_aggregate_init_not_constant) 12435 << Culprit->getSourceRange(); 12436 } 12437 } 12438 12439 if (auto *E = dyn_cast<ExprWithCleanups>(Init)) 12440 if (auto *BE = dyn_cast<BlockExpr>(E->getSubExpr()->IgnoreParens())) 12441 if (VDecl->hasLocalStorage()) 12442 BE->getBlockDecl()->setCanAvoidCopyToHeap(); 12443 } else if (VDecl->isStaticDataMember() && !VDecl->isInline() && 12444 VDecl->getLexicalDeclContext()->isRecord()) { 12445 // This is an in-class initialization for a static data member, e.g., 12446 // 12447 // struct S { 12448 // static const int value = 17; 12449 // }; 12450 12451 // C++ [class.mem]p4: 12452 // A member-declarator can contain a constant-initializer only 12453 // if it declares a static member (9.4) of const integral or 12454 // const enumeration type, see 9.4.2. 12455 // 12456 // C++11 [class.static.data]p3: 12457 // If a non-volatile non-inline const static data member is of integral 12458 // or enumeration type, its declaration in the class definition can 12459 // specify a brace-or-equal-initializer in which every initializer-clause 12460 // that is an assignment-expression is a constant expression. A static 12461 // data member of literal type can be declared in the class definition 12462 // with the constexpr specifier; if so, its declaration shall specify a 12463 // brace-or-equal-initializer in which every initializer-clause that is 12464 // an assignment-expression is a constant expression. 12465 12466 // Do nothing on dependent types. 12467 if (DclT->isDependentType()) { 12468 12469 // Allow any 'static constexpr' members, whether or not they are of literal 12470 // type. We separately check that every constexpr variable is of literal 12471 // type. 12472 } else if (VDecl->isConstexpr()) { 12473 12474 // Require constness. 12475 } else if (!DclT.isConstQualified()) { 12476 Diag(VDecl->getLocation(), diag::err_in_class_initializer_non_const) 12477 << Init->getSourceRange(); 12478 VDecl->setInvalidDecl(); 12479 12480 // We allow integer constant expressions in all cases. 12481 } else if (DclT->isIntegralOrEnumerationType()) { 12482 // Check whether the expression is a constant expression. 12483 SourceLocation Loc; 12484 if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified()) 12485 // In C++11, a non-constexpr const static data member with an 12486 // in-class initializer cannot be volatile. 12487 Diag(VDecl->getLocation(), diag::err_in_class_initializer_volatile); 12488 else if (Init->isValueDependent()) 12489 ; // Nothing to check. 12490 else if (Init->isIntegerConstantExpr(Context, &Loc)) 12491 ; // Ok, it's an ICE! 12492 else if (Init->getType()->isScopedEnumeralType() && 12493 Init->isCXX11ConstantExpr(Context)) 12494 ; // Ok, it is a scoped-enum constant expression. 12495 else if (Init->isEvaluatable(Context)) { 12496 // If we can constant fold the initializer through heroics, accept it, 12497 // but report this as a use of an extension for -pedantic. 12498 Diag(Loc, diag::ext_in_class_initializer_non_constant) 12499 << Init->getSourceRange(); 12500 } else { 12501 // Otherwise, this is some crazy unknown case. Report the issue at the 12502 // location provided by the isIntegerConstantExpr failed check. 12503 Diag(Loc, diag::err_in_class_initializer_non_constant) 12504 << Init->getSourceRange(); 12505 VDecl->setInvalidDecl(); 12506 } 12507 12508 // We allow foldable floating-point constants as an extension. 12509 } else if (DclT->isFloatingType()) { // also permits complex, which is ok 12510 // In C++98, this is a GNU extension. In C++11, it is not, but we support 12511 // it anyway and provide a fixit to add the 'constexpr'. 12512 if (getLangOpts().CPlusPlus11) { 12513 Diag(VDecl->getLocation(), 12514 diag::ext_in_class_initializer_float_type_cxx11) 12515 << DclT << Init->getSourceRange(); 12516 Diag(VDecl->getBeginLoc(), 12517 diag::note_in_class_initializer_float_type_cxx11) 12518 << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr "); 12519 } else { 12520 Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type) 12521 << DclT << Init->getSourceRange(); 12522 12523 if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) { 12524 Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant) 12525 << Init->getSourceRange(); 12526 VDecl->setInvalidDecl(); 12527 } 12528 } 12529 12530 // Suggest adding 'constexpr' in C++11 for literal types. 12531 } else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Context)) { 12532 Diag(VDecl->getLocation(), diag::err_in_class_initializer_literal_type) 12533 << DclT << Init->getSourceRange() 12534 << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr "); 12535 VDecl->setConstexpr(true); 12536 12537 } else { 12538 Diag(VDecl->getLocation(), diag::err_in_class_initializer_bad_type) 12539 << DclT << Init->getSourceRange(); 12540 VDecl->setInvalidDecl(); 12541 } 12542 } else if (VDecl->isFileVarDecl()) { 12543 // In C, extern is typically used to avoid tentative definitions when 12544 // declaring variables in headers, but adding an intializer makes it a 12545 // definition. This is somewhat confusing, so GCC and Clang both warn on it. 12546 // In C++, extern is often used to give implictly static const variables 12547 // external linkage, so don't warn in that case. If selectany is present, 12548 // this might be header code intended for C and C++ inclusion, so apply the 12549 // C++ rules. 12550 if (VDecl->getStorageClass() == SC_Extern && 12551 ((!getLangOpts().CPlusPlus && !VDecl->hasAttr<SelectAnyAttr>()) || 12552 !Context.getBaseElementType(VDecl->getType()).isConstQualified()) && 12553 !(getLangOpts().CPlusPlus && VDecl->isExternC()) && 12554 !isTemplateInstantiation(VDecl->getTemplateSpecializationKind())) 12555 Diag(VDecl->getLocation(), diag::warn_extern_init); 12556 12557 // In Microsoft C++ mode, a const variable defined in namespace scope has 12558 // external linkage by default if the variable is declared with 12559 // __declspec(dllexport). 12560 if (Context.getTargetInfo().getCXXABI().isMicrosoft() && 12561 getLangOpts().CPlusPlus && VDecl->getType().isConstQualified() && 12562 VDecl->hasAttr<DLLExportAttr>() && VDecl->getDefinition()) 12563 VDecl->setStorageClass(SC_Extern); 12564 12565 // C99 6.7.8p4. All file scoped initializers need to be constant. 12566 if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl()) 12567 CheckForConstantInitializer(Init, DclT); 12568 } 12569 12570 QualType InitType = Init->getType(); 12571 if (!InitType.isNull() && 12572 (InitType.hasNonTrivialToPrimitiveDefaultInitializeCUnion() || 12573 InitType.hasNonTrivialToPrimitiveCopyCUnion())) 12574 checkNonTrivialCUnionInInitializer(Init, Init->getExprLoc()); 12575 12576 // We will represent direct-initialization similarly to copy-initialization: 12577 // int x(1); -as-> int x = 1; 12578 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c); 12579 // 12580 // Clients that want to distinguish between the two forms, can check for 12581 // direct initializer using VarDecl::getInitStyle(). 12582 // A major benefit is that clients that don't particularly care about which 12583 // exactly form was it (like the CodeGen) can handle both cases without 12584 // special case code. 12585 12586 // C++ 8.5p11: 12587 // The form of initialization (using parentheses or '=') is generally 12588 // insignificant, but does matter when the entity being initialized has a 12589 // class type. 12590 if (CXXDirectInit) { 12591 assert(DirectInit && "Call-style initializer must be direct init.")((void)0); 12592 VDecl->setInitStyle(VarDecl::CallInit); 12593 } else if (DirectInit) { 12594 // This must be list-initialization. No other way is direct-initialization. 12595 VDecl->setInitStyle(VarDecl::ListInit); 12596 } 12597 12598 if (LangOpts.OpenMP && VDecl->isFileVarDecl()) 12599 DeclsToCheckForDeferredDiags.insert(VDecl); 12600 CheckCompleteVariableDeclaration(VDecl); 12601} 12602 12603/// ActOnInitializerError - Given that there was an error parsing an 12604/// initializer for the given declaration, try to return to some form 12605/// of sanity. 12606void Sema::ActOnInitializerError(Decl *D) { 12607 // Our main concern here is re-establishing invariants like "a 12608 // variable's type is either dependent or complete". 12609 if (!D || D->isInvalidDecl()) return; 12610 12611 VarDecl *VD = dyn_cast<VarDecl>(D); 12612 if (!VD) return; 12613 12614 // Bindings are not usable if we can't make sense of the initializer. 12615 if (auto *DD = dyn_cast<DecompositionDecl>(D)) 12616 for (auto *BD : DD->bindings()) 12617 BD->setInvalidDecl(); 12618 12619 // Auto types are meaningless if we can't make sense of the initializer. 12620 if (VD->getType()->isUndeducedType()) { 12621 D->setInvalidDecl(); 12622 return; 12623 } 12624 12625 QualType Ty = VD->getType(); 12626 if (Ty->isDependentType()) return; 12627 12628 // Require a complete type. 12629 if (RequireCompleteType(VD->getLocation(), 12630 Context.getBaseElementType(Ty), 12631 diag::err_typecheck_decl_incomplete_type)) { 12632 VD->setInvalidDecl(); 12633 return; 12634 } 12635 12636 // Require a non-abstract type. 12637 if (RequireNonAbstractType(VD->getLocation(), Ty, 12638 diag::err_abstract_type_in_decl, 12639 AbstractVariableType)) { 12640 VD->setInvalidDecl(); 12641 return; 12642 } 12643 12644 // Don't bother complaining about constructors or destructors, 12645 // though. 12646} 12647 12648void Sema::ActOnUninitializedDecl(Decl *RealDecl) { 12649 // If there is no declaration, there was an error parsing it. Just ignore it. 12650 if (!RealDecl) 12651 return; 12652 12653 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) { 12654 QualType Type = Var->getType(); 12655 12656 // C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory. 12657 if (isa<DecompositionDecl>(RealDecl)) { 12658 Diag(Var->getLocation(), diag::err_decomp_decl_requires_init) << Var; 12659 Var->setInvalidDecl(); 12660 return; 12661 } 12662 12663 if (Type->isUndeducedType() && 12664 DeduceVariableDeclarationType(Var, false, nullptr)) 12665 return; 12666 12667 // C++11 [class.static.data]p3: A static data member can be declared with 12668 // the constexpr specifier; if so, its declaration shall specify 12669 // a brace-or-equal-initializer. 12670 // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to 12671 // the definition of a variable [...] or the declaration of a static data 12672 // member. 12673 if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() && 12674 !Var->isThisDeclarationADemotedDefinition()) { 12675 if (Var->isStaticDataMember()) { 12676 // C++1z removes the relevant rule; the in-class declaration is always 12677 // a definition there. 12678 if (!getLangOpts().CPlusPlus17 && 12679 !Context.getTargetInfo().getCXXABI().isMicrosoft()) { 12680 Diag(Var->getLocation(), 12681 diag::err_constexpr_static_mem_var_requires_init) 12682 << Var; 12683 Var->setInvalidDecl(); 12684 return; 12685 } 12686 } else { 12687 Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl); 12688 Var->setInvalidDecl(); 12689 return; 12690 } 12691 } 12692 12693 // OpenCL v1.1 s6.5.3: variables declared in the constant address space must 12694 // be initialized. 12695 if (!Var->isInvalidDecl() && 12696 Var->getType().getAddressSpace() == LangAS::opencl_constant && 12697 Var->getStorageClass() != SC_Extern && !Var->getInit()) { 12698 bool HasConstExprDefaultConstructor = false; 12699 if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) { 12700 for (auto *Ctor : RD->ctors()) { 12701 if (Ctor->isConstexpr() && Ctor->getNumParams() == 0 && 12702 Ctor->getMethodQualifiers().getAddressSpace() == 12703 LangAS::opencl_constant) { 12704 HasConstExprDefaultConstructor = true; 12705 } 12706 } 12707 } 12708 if (!HasConstExprDefaultConstructor) { 12709 Diag(Var->getLocation(), diag::err_opencl_constant_no_init); 12710 Var->setInvalidDecl(); 12711 return; 12712 } 12713 } 12714 12715 if (!Var->isInvalidDecl() && RealDecl->hasAttr<LoaderUninitializedAttr>()) { 12716 if (Var->getStorageClass() == SC_Extern) { 12717 Diag(Var->getLocation(), diag::err_loader_uninitialized_extern_decl) 12718 << Var; 12719 Var->setInvalidDecl(); 12720 return; 12721 } 12722 if (RequireCompleteType(Var->getLocation(), Var->getType(), 12723 diag::err_typecheck_decl_incomplete_type)) { 12724 Var->setInvalidDecl(); 12725 return; 12726 } 12727 if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) { 12728 if (!RD->hasTrivialDefaultConstructor()) { 12729 Diag(Var->getLocation(), diag::err_loader_uninitialized_trivial_ctor); 12730 Var->setInvalidDecl(); 12731 return; 12732 } 12733 } 12734 // The declaration is unitialized, no need for further checks. 12735 return; 12736 } 12737 12738 VarDecl::DefinitionKind DefKind = Var->isThisDeclarationADefinition(); 12739 if (!Var->isInvalidDecl() && DefKind != VarDecl::DeclarationOnly && 12740 Var->getType().hasNonTrivialToPrimitiveDefaultInitializeCUnion()) 12741 checkNonTrivialCUnion(Var->getType(), Var->getLocation(), 12742 NTCUC_DefaultInitializedObject, NTCUK_Init); 12743 12744 12745 switch (DefKind) { 12746 case VarDecl::Definition: 12747 if (!Var->isStaticDataMember() || !Var->getAnyInitializer()) 12748 break; 12749 12750 // We have an out-of-line definition of a static data member 12751 // that has an in-class initializer, so we type-check this like 12752 // a declaration. 12753 // 12754 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 12755 12756 case VarDecl::DeclarationOnly: 12757 // It's only a declaration. 12758 12759 // Block scope. C99 6.7p7: If an identifier for an object is 12760 // declared with no linkage (C99 6.2.2p6), the type for the 12761 // object shall be complete. 12762 if (!Type->isDependentType() && Var->isLocalVarDecl() && 12763 !Var->hasLinkage() && !Var->isInvalidDecl() && 12764 RequireCompleteType(Var->getLocation(), Type, 12765 diag::err_typecheck_decl_incomplete_type)) 12766 Var->setInvalidDecl(); 12767 12768 // Make sure that the type is not abstract. 12769 if (!Type->isDependentType() && !Var->isInvalidDecl() && 12770 RequireNonAbstractType(Var->getLocation(), Type, 12771 diag::err_abstract_type_in_decl, 12772 AbstractVariableType)) 12773 Var->setInvalidDecl(); 12774 if (!Type->isDependentType() && !Var->isInvalidDecl() && 12775 Var->getStorageClass() == SC_PrivateExtern) { 12776 Diag(Var->getLocation(), diag::warn_private_extern); 12777 Diag(Var->getLocation(), diag::note_private_extern); 12778 } 12779 12780 if (Context.getTargetInfo().allowDebugInfoForExternalRef() && 12781 !Var->isInvalidDecl() && !getLangOpts().CPlusPlus) 12782 ExternalDeclarations.push_back(Var); 12783 12784 return; 12785 12786 case VarDecl::TentativeDefinition: 12787 // File scope. C99 6.9.2p2: A declaration of an identifier for an 12788 // object that has file scope without an initializer, and without a 12789 // storage-class specifier or with the storage-class specifier "static", 12790 // constitutes a tentative definition. Note: A tentative definition with 12791 // external linkage is valid (C99 6.2.2p5). 12792 if (!Var->isInvalidDecl()) { 12793 if (const IncompleteArrayType *ArrayT 12794 = Context.getAsIncompleteArrayType(Type)) { 12795 if (RequireCompleteSizedType( 12796 Var->getLocation(), ArrayT->getElementType(), 12797 diag::err_array_incomplete_or_sizeless_type)) 12798 Var->setInvalidDecl(); 12799 } else if (Var->getStorageClass() == SC_Static) { 12800 // C99 6.9.2p3: If the declaration of an identifier for an object is 12801 // a tentative definition and has internal linkage (C99 6.2.2p3), the 12802 // declared type shall not be an incomplete type. 12803 // NOTE: code such as the following 12804 // static struct s; 12805 // struct s { int a; }; 12806 // is accepted by gcc. Hence here we issue a warning instead of 12807 // an error and we do not invalidate the static declaration. 12808 // NOTE: to avoid multiple warnings, only check the first declaration. 12809 if (Var->isFirstDecl()) 12810 RequireCompleteType(Var->getLocation(), Type, 12811 diag::ext_typecheck_decl_incomplete_type); 12812 } 12813 } 12814 12815 // Record the tentative definition; we're done. 12816 if (!Var->isInvalidDecl()) 12817 TentativeDefinitions.push_back(Var); 12818 return; 12819 } 12820 12821 // Provide a specific diagnostic for uninitialized variable 12822 // definitions with incomplete array type. 12823 if (Type->isIncompleteArrayType()) { 12824 Diag(Var->getLocation(), 12825 diag::err_typecheck_incomplete_array_needs_initializer); 12826 Var->setInvalidDecl(); 12827 return; 12828 } 12829 12830 // Provide a specific diagnostic for uninitialized variable 12831 // definitions with reference type. 12832 if (Type->isReferenceType()) { 12833 Diag(Var->getLocation(), diag::err_reference_var_requires_init) 12834 << Var << SourceRange(Var->getLocation(), Var->getLocation()); 12835 Var->setInvalidDecl(); 12836 return; 12837 } 12838 12839 // Do not attempt to type-check the default initializer for a 12840 // variable with dependent type. 12841 if (Type->isDependentType()) 12842 return; 12843 12844 if (Var->isInvalidDecl()) 12845 return; 12846 12847 if (!Var->hasAttr<AliasAttr>()) { 12848 if (RequireCompleteType(Var->getLocation(), 12849 Context.getBaseElementType(Type), 12850 diag::err_typecheck_decl_incomplete_type)) { 12851 Var->setInvalidDecl(); 12852 return; 12853 } 12854 } else { 12855 return; 12856 } 12857 12858 // The variable can not have an abstract class type. 12859 if (RequireNonAbstractType(Var->getLocation(), Type, 12860 diag::err_abstract_type_in_decl, 12861 AbstractVariableType)) { 12862 Var->setInvalidDecl(); 12863 return; 12864 } 12865 12866 // Check for jumps past the implicit initializer. C++0x 12867 // clarifies that this applies to a "variable with automatic 12868 // storage duration", not a "local variable". 12869 // C++11 [stmt.dcl]p3 12870 // A program that jumps from a point where a variable with automatic 12871 // storage duration is not in scope to a point where it is in scope is 12872 // ill-formed unless the variable has scalar type, class type with a 12873 // trivial default constructor and a trivial destructor, a cv-qualified 12874 // version of one of these types, or an array of one of the preceding 12875 // types and is declared without an initializer. 12876 if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) { 12877 if (const RecordType *Record 12878 = Context.getBaseElementType(Type)->getAs<RecordType>()) { 12879 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record->getDecl()); 12880 // Mark the function (if we're in one) for further checking even if the 12881 // looser rules of C++11 do not require such checks, so that we can 12882 // diagnose incompatibilities with C++98. 12883 if (!CXXRecord->isPOD()) 12884 setFunctionHasBranchProtectedScope(); 12885 } 12886 } 12887 // In OpenCL, we can't initialize objects in the __local address space, 12888 // even implicitly, so don't synthesize an implicit initializer. 12889 if (getLangOpts().OpenCL && 12890 Var->getType().getAddressSpace() == LangAS::opencl_local) 12891 return; 12892 // C++03 [dcl.init]p9: 12893 // If no initializer is specified for an object, and the 12894 // object is of (possibly cv-qualified) non-POD class type (or 12895 // array thereof), the object shall be default-initialized; if 12896 // the object is of const-qualified type, the underlying class 12897 // type shall have a user-declared default 12898 // constructor. Otherwise, if no initializer is specified for 12899 // a non- static object, the object and its subobjects, if 12900 // any, have an indeterminate initial value); if the object 12901 // or any of its subobjects are of const-qualified type, the 12902 // program is ill-formed. 12903 // C++0x [dcl.init]p11: 12904 // If no initializer is specified for an object, the object is 12905 // default-initialized; [...]. 12906 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var); 12907 InitializationKind Kind 12908 = InitializationKind::CreateDefault(Var->getLocation()); 12909 12910 InitializationSequence InitSeq(*this, Entity, Kind, None); 12911 ExprResult Init = InitSeq.Perform(*this, Entity, Kind, None); 12912 12913 if (Init.get()) { 12914 Var->setInit(MaybeCreateExprWithCleanups(Init.get())); 12915 // This is important for template substitution. 12916 Var->setInitStyle(VarDecl::CallInit); 12917 } else if (Init.isInvalid()) { 12918 // If default-init fails, attach a recovery-expr initializer to track 12919 // that initialization was attempted and failed. 12920 auto RecoveryExpr = 12921 CreateRecoveryExpr(Var->getLocation(), Var->getLocation(), {}); 12922 if (RecoveryExpr.get()) 12923 Var->setInit(RecoveryExpr.get()); 12924 } 12925 12926 CheckCompleteVariableDeclaration(Var); 12927 } 12928} 12929 12930void Sema::ActOnCXXForRangeDecl(Decl *D) { 12931 // If there is no declaration, there was an error parsing it. Ignore it. 12932 if (!D) 12933 return; 12934 12935 VarDecl *VD = dyn_cast<VarDecl>(D); 12936 if (!VD) { 12937 Diag(D->getLocation(), diag::err_for_range_decl_must_be_var); 12938 D->setInvalidDecl(); 12939 return; 12940 } 12941 12942 VD->setCXXForRangeDecl(true); 12943 12944 // for-range-declaration cannot be given a storage class specifier. 12945 int Error = -1; 12946 switch (VD->getStorageClass()) { 12947 case SC_None: 12948 break; 12949 case SC_Extern: 12950 Error = 0; 12951 break; 12952 case SC_Static: 12953 Error = 1; 12954 break; 12955 case SC_PrivateExtern: 12956 Error = 2; 12957 break; 12958 case SC_Auto: 12959 Error = 3; 12960 break; 12961 case SC_Register: 12962 Error = 4; 12963 break; 12964 } 12965 12966 // for-range-declaration cannot be given a storage class specifier con't. 12967 switch (VD->getTSCSpec()) { 12968 case TSCS_thread_local: 12969 Error = 6; 12970 break; 12971 case TSCS___thread: 12972 case TSCS__Thread_local: 12973 case TSCS_unspecified: 12974 break; 12975 } 12976 12977 if (Error != -1) { 12978 Diag(VD->getOuterLocStart(), diag::err_for_range_storage_class) 12979 << VD << Error; 12980 D->setInvalidDecl(); 12981 } 12982} 12983 12984StmtResult 12985Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc, 12986 IdentifierInfo *Ident, 12987 ParsedAttributes &Attrs, 12988 SourceLocation AttrEnd) { 12989 // C++1y [stmt.iter]p1: 12990 // A range-based for statement of the form 12991 // for ( for-range-identifier : for-range-initializer ) statement 12992 // is equivalent to 12993 // for ( auto&& for-range-identifier : for-range-initializer ) statement 12994 DeclSpec DS(Attrs.getPool().getFactory()); 12995 12996 const char *PrevSpec; 12997 unsigned DiagID; 12998 DS.SetTypeSpecType(DeclSpec::TST_auto, IdentLoc, PrevSpec, DiagID, 12999 getPrintingPolicy()); 13000 13001 Declarator D(DS, DeclaratorContext::ForInit); 13002 D.SetIdentifier(Ident, IdentLoc); 13003 D.takeAttributes(Attrs, AttrEnd); 13004 13005 D.AddTypeInfo(DeclaratorChunk::getReference(0, IdentLoc, /*lvalue*/ false), 13006 IdentLoc); 13007 Decl *Var = ActOnDeclarator(S, D); 13008 cast<VarDecl>(Var)->setCXXForRangeDecl(true); 13009 FinalizeDeclaration(Var); 13010 return ActOnDeclStmt(FinalizeDeclaratorGroup(S, DS, Var), IdentLoc, 13011 AttrEnd.isValid() ? AttrEnd : IdentLoc); 13012} 13013 13014void Sema::CheckCompleteVariableDeclaration(VarDecl *var) { 13015 if (var->isInvalidDecl()) return; 13016 13017 MaybeAddCUDAConstantAttr(var); 13018 13019 if (getLangOpts().OpenCL) { 13020 // OpenCL v2.0 s6.12.5 - Every block variable declaration must have an 13021 // initialiser 13022 if (var->getTypeSourceInfo()->getType()->isBlockPointerType() && 13023 !var->hasInit()) { 13024 Diag(var->getLocation(), diag::err_opencl_invalid_block_declaration) 13025 << 1 /*Init*/; 13026 var->setInvalidDecl(); 13027 return; 13028 } 13029 } 13030 13031 // In Objective-C, don't allow jumps past the implicit initialization of a 13032 // local retaining variable. 13033 if (getLangOpts().ObjC && 13034 var->hasLocalStorage()) { 13035 switch (var->getType().getObjCLifetime()) { 13036 case Qualifiers::OCL_None: 13037 case Qualifiers::OCL_ExplicitNone: 13038 case Qualifiers::OCL_Autoreleasing: 13039 break; 13040 13041 case Qualifiers::OCL_Weak: 13042 case Qualifiers::OCL_Strong: 13043 setFunctionHasBranchProtectedScope(); 13044 break; 13045 } 13046 } 13047 13048 if (var->hasLocalStorage() && 13049 var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct) 13050 setFunctionHasBranchProtectedScope(); 13051 13052 // Warn about externally-visible variables being defined without a 13053 // prior declaration. We only want to do this for global 13054 // declarations, but we also specifically need to avoid doing it for 13055 // class members because the linkage of an anonymous class can 13056 // change if it's later given a typedef name. 13057 if (var->isThisDeclarationADefinition() && 13058 var->getDeclContext()->getRedeclContext()->isFileContext() && 13059 var->isExternallyVisible() && var->hasLinkage() && 13060 !var->isInline() && !var->getDescribedVarTemplate() && 13061 !isa<VarTemplatePartialSpecializationDecl>(var) && 13062 !isTemplateInstantiation(var->getTemplateSpecializationKind()) && 13063 !getDiagnostics().isIgnored(diag::warn_missing_variable_declarations, 13064 var->getLocation())) { 13065 // Find a previous declaration that's not a definition. 13066 VarDecl *prev = var->getPreviousDecl(); 13067 while (prev && prev->isThisDeclarationADefinition()) 13068 prev = prev->getPreviousDecl(); 13069 13070 if (!prev) { 13071 Diag(var->getLocation(), diag::warn_missing_variable_declarations) << var; 13072 Diag(var->getTypeSpecStartLoc(), diag::note_static_for_internal_linkage) 13073 << /* variable */ 0; 13074 } 13075 } 13076 13077 // Cache the result of checking for constant initialization. 13078 Optional<bool> CacheHasConstInit; 13079 const Expr *CacheCulprit = nullptr; 13080 auto checkConstInit = [&]() mutable { 13081 if (!CacheHasConstInit) 13082 CacheHasConstInit = var->getInit()->isConstantInitializer( 13083 Context, var->getType()->isReferenceType(), &CacheCulprit); 13084 return *CacheHasConstInit; 13085 }; 13086 13087 if (var->getTLSKind() == VarDecl::TLS_Static) { 13088 if (var->getType().isDestructedType()) { 13089 // GNU C++98 edits for __thread, [basic.start.term]p3: 13090 // The type of an object with thread storage duration shall not 13091 // have a non-trivial destructor. 13092 Diag(var->getLocation(), diag::err_thread_nontrivial_dtor); 13093 if (getLangOpts().CPlusPlus11) 13094 Diag(var->getLocation(), diag::note_use_thread_local); 13095 } else if (getLangOpts().CPlusPlus && var->hasInit()) { 13096 if (!checkConstInit()) { 13097 // GNU C++98 edits for __thread, [basic.start.init]p4: 13098 // An object of thread storage duration shall not require dynamic 13099 // initialization. 13100 // FIXME: Need strict checking here. 13101 Diag(CacheCulprit->getExprLoc(), diag::err_thread_dynamic_init) 13102 << CacheCulprit->getSourceRange(); 13103 if (getLangOpts().CPlusPlus11) 13104 Diag(var->getLocation(), diag::note_use_thread_local); 13105 } 13106 } 13107 } 13108 13109 13110 if (!var->getType()->isStructureType() && var->hasInit() && 13111 isa<InitListExpr>(var->getInit())) { 13112 const auto *ILE = cast<InitListExpr>(var->getInit()); 13113 unsigned NumInits = ILE->getNumInits(); 13114 if (NumInits > 2) 13115 for (unsigned I = 0; I < NumInits; ++I) { 13116 const auto *Init = ILE->getInit(I); 13117 if (!Init) 13118 break; 13119 const auto *SL = dyn_cast<StringLiteral>(Init->IgnoreImpCasts()); 13120 if (!SL) 13121 break; 13122 13123 unsigned NumConcat = SL->getNumConcatenated(); 13124 // Diagnose missing comma in string array initialization. 13125 // Do not warn when all the elements in the initializer are concatenated 13126 // together. Do not warn for macros too. 13127 if (NumConcat == 2 && !SL->getBeginLoc().isMacroID()) { 13128 bool OnlyOneMissingComma = true; 13129 for (unsigned J = I + 1; J < NumInits; ++J) { 13130 const auto *Init = ILE->getInit(J); 13131 if (!Init) 13132 break; 13133 const auto *SLJ = dyn_cast<StringLiteral>(Init->IgnoreImpCasts()); 13134 if (!SLJ || SLJ->getNumConcatenated() > 1) { 13135 OnlyOneMissingComma = false; 13136 break; 13137 } 13138 } 13139 13140 if (OnlyOneMissingComma) { 13141 SmallVector<FixItHint, 1> Hints; 13142 for (unsigned i = 0; i < NumConcat - 1; ++i) 13143 Hints.push_back(FixItHint::CreateInsertion( 13144 PP.getLocForEndOfToken(SL->getStrTokenLoc(i)), ",")); 13145 13146 Diag(SL->getStrTokenLoc(1), 13147 diag::warn_concatenated_literal_array_init) 13148 << Hints; 13149 Diag(SL->getBeginLoc(), 13150 diag::note_concatenated_string_literal_silence); 13151 } 13152 // In any case, stop now. 13153 break; 13154 } 13155 } 13156 } 13157 13158 13159 QualType type = var->getType(); 13160 13161 if (var->hasAttr<BlocksAttr>()) 13162 getCurFunction()->addByrefBlockVar(var); 13163 13164 Expr *Init = var->getInit(); 13165 bool GlobalStorage = var->hasGlobalStorage(); 13166 bool IsGlobal = GlobalStorage && !var->isStaticLocal(); 13167 QualType baseType = Context.getBaseElementType(type); 13168 bool HasConstInit = true; 13169 13170 // Check whether the initializer is sufficiently constant. 13171 if (getLangOpts().CPlusPlus && !type->isDependentType() && Init && 13172 !Init->isValueDependent() && 13173 (GlobalStorage || var->isConstexpr() || 13174 var->mightBeUsableInConstantExpressions(Context))) { 13175 // If this variable might have a constant initializer or might be usable in 13176 // constant expressions, check whether or not it actually is now. We can't 13177 // do this lazily, because the result might depend on things that change 13178 // later, such as which constexpr functions happen to be defined. 13179 SmallVector<PartialDiagnosticAt, 8> Notes; 13180 if (!getLangOpts().CPlusPlus11) { 13181 // Prior to C++11, in contexts where a constant initializer is required, 13182 // the set of valid constant initializers is described by syntactic rules 13183 // in [expr.const]p2-6. 13184 // FIXME: Stricter checking for these rules would be useful for constinit / 13185 // -Wglobal-constructors. 13186 HasConstInit = checkConstInit(); 13187 13188 // Compute and cache the constant value, and remember that we have a 13189 // constant initializer. 13190 if (HasConstInit) { 13191 (void)var->checkForConstantInitialization(Notes); 13192 Notes.clear(); 13193 } else if (CacheCulprit) { 13194 Notes.emplace_back(CacheCulprit->getExprLoc(), 13195 PDiag(diag::note_invalid_subexpr_in_const_expr)); 13196 Notes.back().second << CacheCulprit->getSourceRange(); 13197 } 13198 } else { 13199 // Evaluate the initializer to see if it's a constant initializer. 13200 HasConstInit = var->checkForConstantInitialization(Notes); 13201 } 13202 13203 if (HasConstInit) { 13204 // FIXME: Consider replacing the initializer with a ConstantExpr. 13205 } else if (var->isConstexpr()) { 13206 SourceLocation DiagLoc = var->getLocation(); 13207 // If the note doesn't add any useful information other than a source 13208 // location, fold it into the primary diagnostic. 13209 if (Notes.size() == 1 && Notes[0].second.getDiagID() == 13210 diag::note_invalid_subexpr_in_const_expr) { 13211 DiagLoc = Notes[0].first; 13212 Notes.clear(); 13213 } 13214 Diag(DiagLoc, diag::err_constexpr_var_requires_const_init) 13215 << var << Init->getSourceRange(); 13216 for (unsigned I = 0, N = Notes.size(); I != N; ++I) 13217 Diag(Notes[I].first, Notes[I].second); 13218 } else if (GlobalStorage && var->hasAttr<ConstInitAttr>()) { 13219 auto *Attr = var->getAttr<ConstInitAttr>(); 13220 Diag(var->getLocation(), diag::err_require_constant_init_failed) 13221 << Init->getSourceRange(); 13222 Diag(Attr->getLocation(), diag::note_declared_required_constant_init_here) 13223 << Attr->getRange() << Attr->isConstinit(); 13224 for (auto &it : Notes) 13225 Diag(it.first, it.second); 13226 } else if (IsGlobal && 13227 !getDiagnostics().isIgnored(diag::warn_global_constructor, 13228 var->getLocation())) { 13229 // Warn about globals which don't have a constant initializer. Don't 13230 // warn about globals with a non-trivial destructor because we already 13231 // warned about them. 13232 CXXRecordDecl *RD = baseType->getAsCXXRecordDecl(); 13233 if (!(RD && !RD->hasTrivialDestructor())) { 13234 // checkConstInit() here permits trivial default initialization even in 13235 // C++11 onwards, where such an initializer is not a constant initializer 13236 // but nonetheless doesn't require a global constructor. 13237 if (!checkConstInit()) 13238 Diag(var->getLocation(), diag::warn_global_constructor) 13239 << Init->getSourceRange(); 13240 } 13241 } 13242 } 13243 13244 // Apply section attributes and pragmas to global variables. 13245 if (GlobalStorage && var->isThisDeclarationADefinition() && 13246 !inTemplateInstantiation()) { 13247 PragmaStack<StringLiteral *> *Stack = nullptr; 13248 int SectionFlags = ASTContext::PSF_Read; 13249 if (var->getType().isConstQualified()) { 13250 if (HasConstInit) 13251 Stack = &ConstSegStack; 13252 else { 13253 Stack = &BSSSegStack; 13254 SectionFlags |= ASTContext::PSF_Write; 13255 } 13256 } else if (var->hasInit() && HasConstInit) { 13257 Stack = &DataSegStack; 13258 SectionFlags |= ASTContext::PSF_Write; 13259 } else { 13260 Stack = &BSSSegStack; 13261 SectionFlags |= ASTContext::PSF_Write; 13262 } 13263 if (const SectionAttr *SA = var->getAttr<SectionAttr>()) { 13264 if (SA->getSyntax() == AttributeCommonInfo::AS_Declspec) 13265 SectionFlags |= ASTContext::PSF_Implicit; 13266 UnifySection(SA->getName(), SectionFlags, var); 13267 } else if (Stack->CurrentValue) { 13268 SectionFlags |= ASTContext::PSF_Implicit; 13269 auto SectionName = Stack->CurrentValue->getString(); 13270 var->addAttr(SectionAttr::CreateImplicit( 13271 Context, SectionName, Stack->CurrentPragmaLocation, 13272 AttributeCommonInfo::AS_Pragma, SectionAttr::Declspec_allocate)); 13273 if (UnifySection(SectionName, SectionFlags, var)) 13274 var->dropAttr<SectionAttr>(); 13275 } 13276 13277 // Apply the init_seg attribute if this has an initializer. If the 13278 // initializer turns out to not be dynamic, we'll end up ignoring this 13279 // attribute. 13280 if (CurInitSeg && var->getInit()) 13281 var->addAttr(InitSegAttr::CreateImplicit(Context, CurInitSeg->getString(), 13282 CurInitSegLoc, 13283 AttributeCommonInfo::AS_Pragma)); 13284 } 13285 13286 // All the following checks are C++ only. 13287 if (!getLangOpts().CPlusPlus) { 13288 // If this variable must be emitted, add it as an initializer for the 13289 // current module. 13290 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty()) 13291 Context.addModuleInitializer(ModuleScopes.back().Module, var); 13292 return; 13293 } 13294 13295 // Require the destructor. 13296 if (!type->isDependentType()) 13297 if (const RecordType *recordType = baseType->getAs<RecordType>()) 13298 FinalizeVarWithDestructor(var, recordType); 13299 13300 // If this variable must be emitted, add it as an initializer for the current 13301 // module. 13302 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty()) 13303 Context.addModuleInitializer(ModuleScopes.back().Module, var); 13304 13305 // Build the bindings if this is a structured binding declaration. 13306 if (auto *DD = dyn_cast<DecompositionDecl>(var)) 13307 CheckCompleteDecompositionDeclaration(DD); 13308} 13309 13310/// Check if VD needs to be dllexport/dllimport due to being in a 13311/// dllexport/import function. 13312void Sema::CheckStaticLocalForDllExport(VarDecl *VD) { 13313 assert(VD->isStaticLocal())((void)0); 13314 13315 auto *FD = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod()); 13316 13317 // Find outermost function when VD is in lambda function. 13318 while (FD && !getDLLAttr(FD) && 13319 !FD->hasAttr<DLLExportStaticLocalAttr>() && 13320 !FD->hasAttr<DLLImportStaticLocalAttr>()) { 13321 FD = dyn_cast_or_null<FunctionDecl>(FD->getParentFunctionOrMethod()); 13322 } 13323 13324 if (!FD) 13325 return; 13326 13327 // Static locals inherit dll attributes from their function. 13328 if (Attr *A = getDLLAttr(FD)) { 13329 auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext())); 13330 NewAttr->setInherited(true); 13331 VD->addAttr(NewAttr); 13332 } else if (Attr *A = FD->getAttr<DLLExportStaticLocalAttr>()) { 13333 auto *NewAttr = DLLExportAttr::CreateImplicit(getASTContext(), *A); 13334 NewAttr->setInherited(true); 13335 VD->addAttr(NewAttr); 13336 13337 // Export this function to enforce exporting this static variable even 13338 // if it is not used in this compilation unit. 13339 if (!FD->hasAttr<DLLExportAttr>()) 13340 FD->addAttr(NewAttr); 13341 13342 } else if (Attr *A = FD->getAttr<DLLImportStaticLocalAttr>()) { 13343 auto *NewAttr = DLLImportAttr::CreateImplicit(getASTContext(), *A); 13344 NewAttr->setInherited(true); 13345 VD->addAttr(NewAttr); 13346 } 13347} 13348 13349/// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform 13350/// any semantic actions necessary after any initializer has been attached. 13351void Sema::FinalizeDeclaration(Decl *ThisDecl) { 13352 // Note that we are no longer parsing the initializer for this declaration. 13353 ParsingInitForAutoVars.erase(ThisDecl); 13354 13355 VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDecl); 13356 if (!VD) 13357 return; 13358 13359 // Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active 13360 if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() && 13361 !inTemplateInstantiation() && !VD->hasAttr<SectionAttr>()) { 13362 if (PragmaClangBSSSection.Valid) 13363 VD->addAttr(PragmaClangBSSSectionAttr::CreateImplicit( 13364 Context, PragmaClangBSSSection.SectionName, 13365 PragmaClangBSSSection.PragmaLocation, 13366 AttributeCommonInfo::AS_Pragma)); 13367 if (PragmaClangDataSection.Valid) 13368 VD->addAttr(PragmaClangDataSectionAttr::CreateImplicit( 13369 Context, PragmaClangDataSection.SectionName, 13370 PragmaClangDataSection.PragmaLocation, 13371 AttributeCommonInfo::AS_Pragma)); 13372 if (PragmaClangRodataSection.Valid) 13373 VD->addAttr(PragmaClangRodataSectionAttr::CreateImplicit( 13374 Context, PragmaClangRodataSection.SectionName, 13375 PragmaClangRodataSection.PragmaLocation, 13376 AttributeCommonInfo::AS_Pragma)); 13377 if (PragmaClangRelroSection.Valid) 13378 VD->addAttr(PragmaClangRelroSectionAttr::CreateImplicit( 13379 Context, PragmaClangRelroSection.SectionName, 13380 PragmaClangRelroSection.PragmaLocation, 13381 AttributeCommonInfo::AS_Pragma)); 13382 } 13383 13384 if (auto *DD = dyn_cast<DecompositionDecl>(ThisDecl)) { 13385 for (auto *BD : DD->bindings()) { 13386 FinalizeDeclaration(BD); 13387 } 13388 } 13389 13390 checkAttributesAfterMerging(*this, *VD); 13391 13392 // Perform TLS alignment check here after attributes attached to the variable 13393 // which may affect the alignment have been processed. Only perform the check 13394 // if the target has a maximum TLS alignment (zero means no constraints). 13395 if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) { 13396 // Protect the check so that it's not performed on dependent types and 13397 // dependent alignments (we can't determine the alignment in that case). 13398 if (VD->getTLSKind() && !VD->hasDependentAlignment()) { 13399 CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign); 13400 if (Context.getDeclAlign(VD) > MaxAlignChars) { 13401 Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum) 13402 << (unsigned)Context.getDeclAlign(VD).getQuantity() << VD 13403 << (unsigned)MaxAlignChars.getQuantity(); 13404 } 13405 } 13406 } 13407 13408 if (VD->isStaticLocal()) 13409 CheckStaticLocalForDllExport(VD); 13410 13411 // Perform check for initializers of device-side global variables. 13412 // CUDA allows empty constructors as initializers (see E.2.3.1, CUDA 13413 // 7.5). We must also apply the same checks to all __shared__ 13414 // variables whether they are local or not. CUDA also allows 13415 // constant initializers for __constant__ and __device__ variables. 13416 if (getLangOpts().CUDA) 13417 checkAllowedCUDAInitializer(VD); 13418 13419 // Grab the dllimport or dllexport attribute off of the VarDecl. 13420 const InheritableAttr *DLLAttr = getDLLAttr(VD); 13421 13422 // Imported static data members cannot be defined out-of-line. 13423 if (const auto *IA = dyn_cast_or_null<DLLImportAttr>(DLLAttr)) { 13424 if (VD->isStaticDataMember() && VD->isOutOfLine() && 13425 VD->isThisDeclarationADefinition()) { 13426 // We allow definitions of dllimport class template static data members 13427 // with a warning. 13428 CXXRecordDecl *Context = 13429 cast<CXXRecordDecl>(VD->getFirstDecl()->getDeclContext()); 13430 bool IsClassTemplateMember = 13431 isa<ClassTemplatePartialSpecializationDecl>(Context) || 13432 Context->getDescribedClassTemplate(); 13433 13434 Diag(VD->getLocation(), 13435 IsClassTemplateMember 13436 ? diag::warn_attribute_dllimport_static_field_definition 13437 : diag::err_attribute_dllimport_static_field_definition); 13438 Diag(IA->getLocation(), diag::note_attribute); 13439 if (!IsClassTemplateMember) 13440 VD->setInvalidDecl(); 13441 } 13442 } 13443 13444 // dllimport/dllexport variables cannot be thread local, their TLS index 13445 // isn't exported with the variable. 13446 if (DLLAttr && VD->getTLSKind()) { 13447 auto *F = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod()); 13448 if (F && getDLLAttr(F)) { 13449 assert(VD->isStaticLocal())((void)0); 13450 // But if this is a static local in a dlimport/dllexport function, the 13451 // function will never be inlined, which means the var would never be 13452 // imported, so having it marked import/export is safe. 13453 } else { 13454 Diag(VD->getLocation(), diag::err_attribute_dll_thread_local) << VD 13455 << DLLAttr; 13456 VD->setInvalidDecl(); 13457 } 13458 } 13459 13460 if (UsedAttr *Attr = VD->getAttr<UsedAttr>()) { 13461 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) { 13462 Diag(Attr->getLocation(), diag::warn_attribute_ignored_on_non_definition) 13463 << Attr; 13464 VD->dropAttr<UsedAttr>(); 13465 } 13466 } 13467 if (RetainAttr *Attr = VD->getAttr<RetainAttr>()) { 13468 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) { 13469 Diag(Attr->getLocation(), diag::warn_attribute_ignored_on_non_definition) 13470 << Attr; 13471 VD->dropAttr<RetainAttr>(); 13472 } 13473 } 13474 13475 const DeclContext *DC = VD->getDeclContext(); 13476 // If there's a #pragma GCC visibility in scope, and this isn't a class 13477 // member, set the visibility of this variable. 13478 if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible()) 13479 AddPushedVisibilityAttribute(VD); 13480 13481 // FIXME: Warn on unused var template partial specializations. 13482 if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(VD)) 13483 MarkUnusedFileScopedDecl(VD); 13484 13485 // Now we have parsed the initializer and can update the table of magic 13486 // tag values. 13487 if (!VD->hasAttr<TypeTagForDatatypeAttr>() || 13488 !VD->getType()->isIntegralOrEnumerationType()) 13489 return; 13490 13491 for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) { 13492 const Expr *MagicValueExpr = VD->getInit(); 13493 if (!MagicValueExpr) { 13494 continue; 13495 } 13496 Optional<llvm::APSInt> MagicValueInt; 13497 if (!(MagicValueInt = MagicValueExpr->getIntegerConstantExpr(Context))) { 13498 Diag(I->getRange().getBegin(), 13499 diag::err_type_tag_for_datatype_not_ice) 13500 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange(); 13501 continue; 13502 } 13503 if (MagicValueInt->getActiveBits() > 64) { 13504 Diag(I->getRange().getBegin(), 13505 diag::err_type_tag_for_datatype_too_large) 13506 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange(); 13507 continue; 13508 } 13509 uint64_t MagicValue = MagicValueInt->getZExtValue(); 13510 RegisterTypeTagForDatatype(I->getArgumentKind(), 13511 MagicValue, 13512 I->getMatchingCType(), 13513 I->getLayoutCompatible(), 13514 I->getMustBeNull()); 13515 } 13516} 13517 13518static bool hasDeducedAuto(DeclaratorDecl *DD) { 13519 auto *VD = dyn_cast<VarDecl>(DD); 13520 return VD && !VD->getType()->hasAutoForTrailingReturnType(); 13521} 13522 13523Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS, 13524 ArrayRef<Decl *> Group) { 13525 SmallVector<Decl*, 8> Decls; 13526 13527 if (DS.isTypeSpecOwned()) 13528 Decls.push_back(DS.getRepAsDecl()); 13529 13530 DeclaratorDecl *FirstDeclaratorInGroup = nullptr; 13531 DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr; 13532 bool DiagnosedMultipleDecomps = false; 13533 DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr; 13534 bool DiagnosedNonDeducedAuto = false; 13535 13536 for (unsigned i = 0, e = Group.size(); i != e; ++i) { 13537 if (Decl *D = Group[i]) { 13538 // For declarators, there are some additional syntactic-ish checks we need 13539 // to perform. 13540 if (auto *DD = dyn_cast<DeclaratorDecl>(D)) { 13541 if (!FirstDeclaratorInGroup) 13542 FirstDeclaratorInGroup = DD; 13543 if (!FirstDecompDeclaratorInGroup) 13544 FirstDecompDeclaratorInGroup = dyn_cast<DecompositionDecl>(D); 13545 if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() && 13546 !hasDeducedAuto(DD)) 13547 FirstNonDeducedAutoInGroup = DD; 13548 13549 if (FirstDeclaratorInGroup != DD) { 13550 // A decomposition declaration cannot be combined with any other 13551 // declaration in the same group. 13552 if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) { 13553 Diag(FirstDecompDeclaratorInGroup->getLocation(), 13554 diag::err_decomp_decl_not_alone) 13555 << FirstDeclaratorInGroup->getSourceRange() 13556 << DD->getSourceRange(); 13557 DiagnosedMultipleDecomps = true; 13558 } 13559 13560 // A declarator that uses 'auto' in any way other than to declare a 13561 // variable with a deduced type cannot be combined with any other 13562 // declarator in the same group. 13563 if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) { 13564 Diag(FirstNonDeducedAutoInGroup->getLocation(), 13565 diag::err_auto_non_deduced_not_alone) 13566 << FirstNonDeducedAutoInGroup->getType() 13567 ->hasAutoForTrailingReturnType() 13568 << FirstDeclaratorInGroup->getSourceRange() 13569 << DD->getSourceRange(); 13570 DiagnosedNonDeducedAuto = true; 13571 } 13572 } 13573 } 13574 13575 Decls.push_back(D); 13576 } 13577 } 13578 13579 if (DeclSpec::isDeclRep(DS.getTypeSpecType())) { 13580 if (TagDecl *Tag = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl())) { 13581 handleTagNumbering(Tag, S); 13582 if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() && 13583 getLangOpts().CPlusPlus) 13584 Context.addDeclaratorForUnnamedTagDecl(Tag, FirstDeclaratorInGroup); 13585 } 13586 } 13587 13588 return BuildDeclaratorGroup(Decls); 13589} 13590 13591/// BuildDeclaratorGroup - convert a list of declarations into a declaration 13592/// group, performing any necessary semantic checking. 13593Sema::DeclGroupPtrTy 13594Sema::BuildDeclaratorGroup(MutableArrayRef<Decl *> Group) { 13595 // C++14 [dcl.spec.auto]p7: (DR1347) 13596 // If the type that replaces the placeholder type is not the same in each 13597 // deduction, the program is ill-formed. 13598 if (Group.size() > 1) { 13599 QualType Deduced; 13600 VarDecl *DeducedDecl = nullptr; 13601 for (unsigned i = 0, e = Group.size(); i != e; ++i) { 13602 VarDecl *D = dyn_cast<VarDecl>(Group[i]); 13603 if (!D || D->isInvalidDecl()) 13604 break; 13605 DeducedType *DT = D->getType()->getContainedDeducedType(); 13606 if (!DT || DT->getDeducedType().isNull()) 13607 continue; 13608 if (Deduced.isNull()) { 13609 Deduced = DT->getDeducedType(); 13610 DeducedDecl = D; 13611 } else if (!Context.hasSameType(DT->getDeducedType(), Deduced)) { 13612 auto *AT = dyn_cast<AutoType>(DT); 13613 auto Dia = Diag(D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(), 13614 diag::err_auto_different_deductions) 13615 << (AT ? (unsigned)AT->getKeyword() : 3) << Deduced 13616 << DeducedDecl->getDeclName() << DT->getDeducedType() 13617 << D->getDeclName(); 13618 if (DeducedDecl->hasInit()) 13619 Dia << DeducedDecl->getInit()->getSourceRange(); 13620 if (D->getInit()) 13621 Dia << D->getInit()->getSourceRange(); 13622 D->setInvalidDecl(); 13623 break; 13624 } 13625 } 13626 } 13627 13628 ActOnDocumentableDecls(Group); 13629 13630 return DeclGroupPtrTy::make( 13631 DeclGroupRef::Create(Context, Group.data(), Group.size())); 13632} 13633 13634void Sema::ActOnDocumentableDecl(Decl *D) { 13635 ActOnDocumentableDecls(D); 13636} 13637 13638void Sema::ActOnDocumentableDecls(ArrayRef<Decl *> Group) { 13639 // Don't parse the comment if Doxygen diagnostics are ignored. 13640 if (Group.empty() || !Group[0]) 13641 return; 13642 13643 if (Diags.isIgnored(diag::warn_doc_param_not_found, 13644 Group[0]->getLocation()) && 13645 Diags.isIgnored(diag::warn_unknown_comment_command_name, 13646 Group[0]->getLocation())) 13647 return; 13648 13649 if (Group.size() >= 2) { 13650 // This is a decl group. Normally it will contain only declarations 13651 // produced from declarator list. But in case we have any definitions or 13652 // additional declaration references: 13653 // 'typedef struct S {} S;' 13654 // 'typedef struct S *S;' 13655 // 'struct S *pS;' 13656 // FinalizeDeclaratorGroup adds these as separate declarations. 13657 Decl *MaybeTagDecl = Group[0]; 13658 if (MaybeTagDecl && isa<TagDecl>(MaybeTagDecl)) { 13659 Group = Group.slice(1); 13660 } 13661 } 13662 13663 // FIMXE: We assume every Decl in the group is in the same file. 13664 // This is false when preprocessor constructs the group from decls in 13665 // different files (e. g. macros or #include). 13666 Context.attachCommentsToJustParsedDecls(Group, &getPreprocessor()); 13667} 13668 13669/// Common checks for a parameter-declaration that should apply to both function 13670/// parameters and non-type template parameters. 13671void Sema::CheckFunctionOrTemplateParamDeclarator(Scope *S, Declarator &D) { 13672 // Check that there are no default arguments inside the type of this 13673 // parameter. 13674 if (getLangOpts().CPlusPlus) 13675 CheckExtraCXXDefaultArguments(D); 13676 13677 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1). 13678 if (D.getCXXScopeSpec().isSet()) { 13679 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator) 13680 << D.getCXXScopeSpec().getRange(); 13681 } 13682 13683 // [dcl.meaning]p1: An unqualified-id occurring in a declarator-id shall be a 13684 // simple identifier except [...irrelevant cases...]. 13685 switch (D.getName().getKind()) { 13686 case UnqualifiedIdKind::IK_Identifier: 13687 break; 13688 13689 case UnqualifiedIdKind::IK_OperatorFunctionId: 13690 case UnqualifiedIdKind::IK_ConversionFunctionId: 13691 case UnqualifiedIdKind::IK_LiteralOperatorId: 13692 case UnqualifiedIdKind::IK_ConstructorName: 13693 case UnqualifiedIdKind::IK_DestructorName: 13694 case UnqualifiedIdKind::IK_ImplicitSelfParam: 13695 case UnqualifiedIdKind::IK_DeductionGuideName: 13696 Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name) 13697 << GetNameForDeclarator(D).getName(); 13698 break; 13699 13700 case UnqualifiedIdKind::IK_TemplateId: 13701 case UnqualifiedIdKind::IK_ConstructorTemplateId: 13702 // GetNameForDeclarator would not produce a useful name in this case. 13703 Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name_template_id); 13704 break; 13705 } 13706} 13707 13708/// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator() 13709/// to introduce parameters into function prototype scope. 13710Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D) { 13711 const DeclSpec &DS = D.getDeclSpec(); 13712 13713 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'. 13714 13715 // C++03 [dcl.stc]p2 also permits 'auto'. 13716 StorageClass SC = SC_None; 13717 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) { 13718 SC = SC_Register; 13719 // In C++11, the 'register' storage class specifier is deprecated. 13720 // In C++17, it is not allowed, but we tolerate it as an extension. 13721 if (getLangOpts().CPlusPlus11) { 13722 Diag(DS.getStorageClassSpecLoc(), 13723 getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class 13724 : diag::warn_deprecated_register) 13725 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc()); 13726 } 13727 } else if (getLangOpts().CPlusPlus && 13728 DS.getStorageClassSpec() == DeclSpec::SCS_auto) { 13729 SC = SC_Auto; 13730 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) { 13731 Diag(DS.getStorageClassSpecLoc(), 13732 diag::err_invalid_storage_class_in_func_decl); 13733 D.getMutableDeclSpec().ClearStorageClassSpecs(); 13734 } 13735 13736 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec()) 13737 Diag(DS.getThreadStorageClassSpecLoc(), diag::err_invalid_thread) 13738 << DeclSpec::getSpecifierName(TSCS); 13739 if (DS.isInlineSpecified()) 13740 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function) 13741 << getLangOpts().CPlusPlus17; 13742 if (DS.hasConstexprSpecifier()) 13743 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr) 13744 << 0 << static_cast<int>(D.getDeclSpec().getConstexprSpecifier()); 13745 13746 DiagnoseFunctionSpecifiers(DS); 13747 13748 CheckFunctionOrTemplateParamDeclarator(S, D); 13749 13750 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 13751 QualType parmDeclType = TInfo->getType(); 13752 13753 // Check for redeclaration of parameters, e.g. int foo(int x, int x); 13754 IdentifierInfo *II = D.getIdentifier(); 13755 if (II) { 13756 LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName, 13757 ForVisibleRedeclaration); 13758 LookupName(R, S); 13759 if (R.isSingleResult()) { 13760 NamedDecl *PrevDecl = R.getFoundDecl(); 13761 if (PrevDecl->isTemplateParameter()) { 13762 // Maybe we will complain about the shadowed template parameter. 13763 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 13764 // Just pretend that we didn't see the previous declaration. 13765 PrevDecl = nullptr; 13766 } else if (S->isDeclScope(PrevDecl)) { 13767 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II; 13768 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 13769 13770 // Recover by removing the name 13771 II = nullptr; 13772 D.SetIdentifier(nullptr, D.getIdentifierLoc()); 13773 D.setInvalidType(true); 13774 } 13775 } 13776 } 13777 13778 // Temporarily put parameter variables in the translation unit, not 13779 // the enclosing context. This prevents them from accidentally 13780 // looking like class members in C++. 13781 ParmVarDecl *New = 13782 CheckParameter(Context.getTranslationUnitDecl(), D.getBeginLoc(), 13783 D.getIdentifierLoc(), II, parmDeclType, TInfo, SC); 13784 13785 if (D.isInvalidType()) 13786 New->setInvalidDecl(); 13787 13788 assert(S->isFunctionPrototypeScope())((void)0); 13789 assert(S->getFunctionPrototypeDepth() >= 1)((void)0); 13790 New->setScopeInfo(S->getFunctionPrototypeDepth() - 1, 13791 S->getNextFunctionPrototypeIndex()); 13792 13793 // Add the parameter declaration into this scope. 13794 S->AddDecl(New); 13795 if (II) 13796 IdResolver.AddDecl(New); 13797 13798 ProcessDeclAttributes(S, New, D); 13799 13800 if (D.getDeclSpec().isModulePrivateSpecified()) 13801 Diag(New->getLocation(), diag::err_module_private_local) 13802 << 1 << New << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc()) 13803 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc()); 13804 13805 if (New->hasAttr<BlocksAttr>()) { 13806 Diag(New->getLocation(), diag::err_block_on_nonlocal); 13807 } 13808 13809 if (getLangOpts().OpenCL) 13810 deduceOpenCLAddressSpace(New); 13811 13812 return New; 13813} 13814 13815/// Synthesizes a variable for a parameter arising from a 13816/// typedef. 13817ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC, 13818 SourceLocation Loc, 13819 QualType T) { 13820 /* FIXME: setting StartLoc == Loc. 13821 Would it be worth to modify callers so as to provide proper source 13822 location for the unnamed parameters, embedding the parameter's type? */ 13823 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, Loc, Loc, nullptr, 13824 T, Context.getTrivialTypeSourceInfo(T, Loc), 13825 SC_None, nullptr); 13826 Param->setImplicit(); 13827 return Param; 13828} 13829 13830void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) { 13831 // Don't diagnose unused-parameter errors in template instantiations; we 13832 // will already have done so in the template itself. 13833 if (inTemplateInstantiation()) 13834 return; 13835 13836 for (const ParmVarDecl *Parameter : Parameters) { 13837 if (!Parameter->isReferenced() && Parameter->getDeclName() && 13838 !Parameter->hasAttr<UnusedAttr>()) { 13839 Diag(Parameter->getLocation(), diag::warn_unused_parameter) 13840 << Parameter->getDeclName(); 13841 } 13842 } 13843} 13844 13845void Sema::DiagnoseSizeOfParametersAndReturnValue( 13846 ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) { 13847 if (LangOpts.NumLargeByValueCopy == 0) // No check. 13848 return; 13849 13850 // Warn if the return value is pass-by-value and larger than the specified 13851 // threshold. 13852 if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) { 13853 unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity(); 13854 if (Size > LangOpts.NumLargeByValueCopy) 13855 Diag(D->getLocation(), diag::warn_return_value_size) << D << Size; 13856 } 13857 13858 // Warn if any parameter is pass-by-value and larger than the specified 13859 // threshold. 13860 for (const ParmVarDecl *Parameter : Parameters) { 13861 QualType T = Parameter->getType(); 13862 if (T->isDependentType() || !T.isPODType(Context)) 13863 continue; 13864 unsigned Size = Context.getTypeSizeInChars(T).getQuantity(); 13865 if (Size > LangOpts.NumLargeByValueCopy) 13866 Diag(Parameter->getLocation(), diag::warn_parameter_size) 13867 << Parameter << Size; 13868 } 13869} 13870 13871ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc, 13872 SourceLocation NameLoc, IdentifierInfo *Name, 13873 QualType T, TypeSourceInfo *TSInfo, 13874 StorageClass SC) { 13875 // In ARC, infer a lifetime qualifier for appropriate parameter types. 13876 if (getLangOpts().ObjCAutoRefCount && 13877 T.getObjCLifetime() == Qualifiers::OCL_None && 13878 T->isObjCLifetimeType()) { 13879 13880 Qualifiers::ObjCLifetime lifetime; 13881 13882 // Special cases for arrays: 13883 // - if it's const, use __unsafe_unretained 13884 // - otherwise, it's an error 13885 if (T->isArrayType()) { 13886 if (!T.isConstQualified()) { 13887 if (DelayedDiagnostics.shouldDelayDiagnostics()) 13888 DelayedDiagnostics.add( 13889 sema::DelayedDiagnostic::makeForbiddenType( 13890 NameLoc, diag::err_arc_array_param_no_ownership, T, false)); 13891 else 13892 Diag(NameLoc, diag::err_arc_array_param_no_ownership) 13893 << TSInfo->getTypeLoc().getSourceRange(); 13894 } 13895 lifetime = Qualifiers::OCL_ExplicitNone; 13896 } else { 13897 lifetime = T->getObjCARCImplicitLifetime(); 13898 } 13899 T = Context.getLifetimeQualifiedType(T, lifetime); 13900 } 13901 13902 ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name, 13903 Context.getAdjustedParameterType(T), 13904 TSInfo, SC, nullptr); 13905 13906 // Make a note if we created a new pack in the scope of a lambda, so that 13907 // we know that references to that pack must also be expanded within the 13908 // lambda scope. 13909 if (New->isParameterPack()) 13910 if (auto *LSI = getEnclosingLambda()) 13911 LSI->LocalPacks.push_back(New); 13912 13913 if (New->getType().hasNonTrivialToPrimitiveDestructCUnion() || 13914 New->getType().hasNonTrivialToPrimitiveCopyCUnion()) 13915 checkNonTrivialCUnion(New->getType(), New->getLocation(), 13916 NTCUC_FunctionParam, NTCUK_Destruct|NTCUK_Copy); 13917 13918 // Parameters can not be abstract class types. 13919 // For record types, this is done by the AbstractClassUsageDiagnoser once 13920 // the class has been completely parsed. 13921 if (!CurContext->isRecord() && 13922 RequireNonAbstractType(NameLoc, T, diag::err_abstract_type_in_decl, 13923 AbstractParamType)) 13924 New->setInvalidDecl(); 13925 13926 // Parameter declarators cannot be interface types. All ObjC objects are 13927 // passed by reference. 13928 if (T->isObjCObjectType()) { 13929 SourceLocation TypeEndLoc = 13930 getLocForEndOfToken(TSInfo->getTypeLoc().getEndLoc()); 13931 Diag(NameLoc, 13932 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T 13933 << FixItHint::CreateInsertion(TypeEndLoc, "*"); 13934 T = Context.getObjCObjectPointerType(T); 13935 New->setType(T); 13936 } 13937 13938 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage 13939 // duration shall not be qualified by an address-space qualifier." 13940 // Since all parameters have automatic store duration, they can not have 13941 // an address space. 13942 if (T.getAddressSpace() != LangAS::Default && 13943 // OpenCL allows function arguments declared to be an array of a type 13944 // to be qualified with an address space. 13945 !(getLangOpts().OpenCL && 13946 (T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private))) { 13947 Diag(NameLoc, diag::err_arg_with_address_space); 13948 New->setInvalidDecl(); 13949 } 13950 13951 // PPC MMA non-pointer types are not allowed as function argument types. 13952 if (Context.getTargetInfo().getTriple().isPPC64() && 13953 CheckPPCMMAType(New->getOriginalType(), New->getLocation())) { 13954 New->setInvalidDecl(); 13955 } 13956 13957 return New; 13958} 13959 13960void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D, 13961 SourceLocation LocAfterDecls) { 13962 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 13963 13964 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared' 13965 // for a K&R function. 13966 if (!FTI.hasPrototype) { 13967 for (int i = FTI.NumParams; i != 0; /* decrement in loop */) { 13968 --i; 13969 if (FTI.Params[i].Param == nullptr) { 13970 SmallString<256> Code; 13971 llvm::raw_svector_ostream(Code) 13972 << " int " << FTI.Params[i].Ident->getName() << ";\n"; 13973 Diag(FTI.Params[i].IdentLoc, diag::ext_param_not_declared) 13974 << FTI.Params[i].Ident 13975 << FixItHint::CreateInsertion(LocAfterDecls, Code); 13976 13977 // Implicitly declare the argument as type 'int' for lack of a better 13978 // type. 13979 AttributeFactory attrs; 13980 DeclSpec DS(attrs); 13981 const char* PrevSpec; // unused 13982 unsigned DiagID; // unused 13983 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.Params[i].IdentLoc, PrevSpec, 13984 DiagID, Context.getPrintingPolicy()); 13985 // Use the identifier location for the type source range. 13986 DS.SetRangeStart(FTI.Params[i].IdentLoc); 13987 DS.SetRangeEnd(FTI.Params[i].IdentLoc); 13988 Declarator ParamD(DS, DeclaratorContext::KNRTypeList); 13989 ParamD.SetIdentifier(FTI.Params[i].Ident, FTI.Params[i].IdentLoc); 13990 FTI.Params[i].Param = ActOnParamDeclarator(S, ParamD); 13991 } 13992 } 13993 } 13994} 13995 13996Decl * 13997Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D, 13998 MultiTemplateParamsArg TemplateParameterLists, 13999 SkipBodyInfo *SkipBody) { 14000 assert(getCurFunctionDecl() == nullptr && "Function parsing confused")((void)0); 14001 assert(D.isFunctionDeclarator() && "Not a function declarator!")((void)0); 14002 Scope *ParentScope = FnBodyScope->getParent(); 14003 14004 // Check if we are in an `omp begin/end declare variant` scope. If we are, and 14005 // we define a non-templated function definition, we will create a declaration 14006 // instead (=BaseFD), and emit the definition with a mangled name afterwards. 14007 // The base function declaration will have the equivalent of an `omp declare 14008 // variant` annotation which specifies the mangled definition as a 14009 // specialization function under the OpenMP context defined as part of the 14010 // `omp begin declare variant`. 14011 SmallVector<FunctionDecl *, 4> Bases; 14012 if (LangOpts.OpenMP && isInOpenMPDeclareVariantScope()) 14013 ActOnStartOfFunctionDefinitionInOpenMPDeclareVariantScope( 14014 ParentScope, D, TemplateParameterLists, Bases); 14015 14016 D.setFunctionDefinitionKind(FunctionDefinitionKind::Definition); 14017 Decl *DP = HandleDeclarator(ParentScope, D, TemplateParameterLists); 14018 Decl *Dcl = ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody); 14019 14020 if (!Bases.empty()) 14021 ActOnFinishedFunctionDefinitionInOpenMPDeclareVariantScope(Dcl, Bases); 14022 14023 return Dcl; 14024} 14025 14026void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) { 14027 Consumer.HandleInlineFunctionDefinition(D); 14028} 14029 14030static bool 14031ShouldWarnAboutMissingPrototype(const FunctionDecl *FD, 14032 const FunctionDecl *&PossiblePrototype) { 14033 // Don't warn about invalid declarations. 14034 if (FD->isInvalidDecl()) 14035 return false; 14036 14037 // Or declarations that aren't global. 14038 if (!FD->isGlobal()) 14039 return false; 14040 14041 // Don't warn about C++ member functions. 14042 if (isa<CXXMethodDecl>(FD)) 14043 return false; 14044 14045 // Don't warn about 'main'. 14046 if (isa<TranslationUnitDecl>(FD->getDeclContext()->getRedeclContext())) 14047 if (IdentifierInfo *II = FD->getIdentifier()) 14048 if (II->isStr("main") || II->isStr("efi_main")) 14049 return false; 14050 14051 // Don't warn about inline functions. 14052 if (FD->isInlined()) 14053 return false; 14054 14055 // Don't warn about function templates. 14056 if (FD->getDescribedFunctionTemplate()) 14057 return false; 14058 14059 // Don't warn about function template specializations. 14060 if (FD->isFunctionTemplateSpecialization()) 14061 return false; 14062 14063 // Don't warn for OpenCL kernels. 14064 if (FD->hasAttr<OpenCLKernelAttr>()) 14065 return false; 14066 14067 // Don't warn on explicitly deleted functions. 14068 if (FD->isDeleted()) 14069 return false; 14070 14071 for (const FunctionDecl *Prev = FD->getPreviousDecl(); 14072 Prev; Prev = Prev->getPreviousDecl()) { 14073 // Ignore any declarations that occur in function or method 14074 // scope, because they aren't visible from the header. 14075 if (Prev->getLexicalDeclContext()->isFunctionOrMethod()) 14076 continue; 14077 14078 PossiblePrototype = Prev; 14079 return Prev->getType()->isFunctionNoProtoType(); 14080 } 14081 14082 return true; 14083} 14084 14085void 14086Sema::CheckForFunctionRedefinition(FunctionDecl *FD, 14087 const FunctionDecl *EffectiveDefinition, 14088 SkipBodyInfo *SkipBody) { 14089 const FunctionDecl *Definition = EffectiveDefinition; 14090 if (!Definition && 14091 !FD->isDefined(Definition, /*CheckForPendingFriendDefinition*/ true)) 14092 return; 14093 14094 if (Definition->getFriendObjectKind() != Decl::FOK_None) { 14095 if (FunctionDecl *OrigDef = Definition->getInstantiatedFromMemberFunction()) { 14096 if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) { 14097 // A merged copy of the same function, instantiated as a member of 14098 // the same class, is OK. 14099 if (declaresSameEntity(OrigFD, OrigDef) && 14100 declaresSameEntity(cast<Decl>(Definition->getLexicalDeclContext()), 14101 cast<Decl>(FD->getLexicalDeclContext()))) 14102 return; 14103 } 14104 } 14105 } 14106 14107 if (canRedefineFunction(Definition, getLangOpts())) 14108 return; 14109 14110 // Don't emit an error when this is redefinition of a typo-corrected 14111 // definition. 14112 if (TypoCorrectedFunctionDefinitions.count(Definition)) 14113 return; 14114 14115 // If we don't have a visible definition of the function, and it's inline or 14116 // a template, skip the new definition. 14117 if (SkipBody && !hasVisibleDefinition(Definition) && 14118 (Definition->getFormalLinkage() == InternalLinkage || 14119 Definition->isInlined() || 14120 Definition->getDescribedFunctionTemplate() || 14121 Definition->getNumTemplateParameterLists())) { 14122 SkipBody->ShouldSkip = true; 14123 SkipBody->Previous = const_cast<FunctionDecl*>(Definition); 14124 if (auto *TD = Definition->getDescribedFunctionTemplate()) 14125 makeMergedDefinitionVisible(TD); 14126 makeMergedDefinitionVisible(const_cast<FunctionDecl*>(Definition)); 14127 return; 14128 } 14129 14130 if (getLangOpts().GNUMode && Definition->isInlineSpecified() && 14131 Definition->getStorageClass() == SC_Extern) 14132 Diag(FD->getLocation(), diag::err_redefinition_extern_inline) 14133 << FD << getLangOpts().CPlusPlus; 14134 else 14135 Diag(FD->getLocation(), diag::err_redefinition) << FD; 14136 14137 Diag(Definition->getLocation(), diag::note_previous_definition); 14138 FD->setInvalidDecl(); 14139} 14140 14141static void RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator, 14142 Sema &S) { 14143 CXXRecordDecl *const LambdaClass = CallOperator->getParent(); 14144 14145 LambdaScopeInfo *LSI = S.PushLambdaScope(); 14146 LSI->CallOperator = CallOperator; 14147 LSI->Lambda = LambdaClass; 14148 LSI->ReturnType = CallOperator->getReturnType(); 14149 const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault(); 14150 14151 if (LCD == LCD_None) 14152 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None; 14153 else if (LCD == LCD_ByCopy) 14154 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval; 14155 else if (LCD == LCD_ByRef) 14156 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref; 14157 DeclarationNameInfo DNI = CallOperator->getNameInfo(); 14158 14159 LSI->IntroducerRange = DNI.getCXXOperatorNameRange(); 14160 LSI->Mutable = !CallOperator->isConst(); 14161 14162 // Add the captures to the LSI so they can be noted as already 14163 // captured within tryCaptureVar. 14164 auto I = LambdaClass->field_begin(); 14165 for (const auto &C : LambdaClass->captures()) { 14166 if (C.capturesVariable()) { 14167 VarDecl *VD = C.getCapturedVar(); 14168 if (VD->isInitCapture()) 14169 S.CurrentInstantiationScope->InstantiatedLocal(VD, VD); 14170 const bool ByRef = C.getCaptureKind() == LCK_ByRef; 14171 LSI->addCapture(VD, /*IsBlock*/false, ByRef, 14172 /*RefersToEnclosingVariableOrCapture*/true, C.getLocation(), 14173 /*EllipsisLoc*/C.isPackExpansion() 14174 ? C.getEllipsisLoc() : SourceLocation(), 14175 I->getType(), /*Invalid*/false); 14176 14177 } else if (C.capturesThis()) { 14178 LSI->addThisCapture(/*Nested*/ false, C.getLocation(), I->getType(), 14179 C.getCaptureKind() == LCK_StarThis); 14180 } else { 14181 LSI->addVLATypeCapture(C.getLocation(), I->getCapturedVLAType(), 14182 I->getType()); 14183 } 14184 ++I; 14185 } 14186} 14187 14188Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D, 14189 SkipBodyInfo *SkipBody) { 14190 if (!D) { 14191 // Parsing the function declaration failed in some way. Push on a fake scope 14192 // anyway so we can try to parse the function body. 14193 PushFunctionScope(); 14194 PushExpressionEvaluationContext(ExprEvalContexts.back().Context); 14195 return D; 14196 } 14197 14198 FunctionDecl *FD = nullptr; 14199 14200 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D)) 14201 FD = FunTmpl->getTemplatedDecl(); 14202 else 14203 FD = cast<FunctionDecl>(D); 14204 14205 // Do not push if it is a lambda because one is already pushed when building 14206 // the lambda in ActOnStartOfLambdaDefinition(). 14207 if (!isLambdaCallOperator(FD)) 14208 PushExpressionEvaluationContext( 14209 FD->isConsteval() ? ExpressionEvaluationContext::ConstantEvaluated 14210 : ExprEvalContexts.back().Context); 14211 14212 // Check for defining attributes before the check for redefinition. 14213 if (const auto *Attr = FD->getAttr<AliasAttr>()) { 14214 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0; 14215 FD->dropAttr<AliasAttr>(); 14216 FD->setInvalidDecl(); 14217 } 14218 if (const auto *Attr = FD->getAttr<IFuncAttr>()) { 14219 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 1; 14220 FD->dropAttr<IFuncAttr>(); 14221 FD->setInvalidDecl(); 14222 } 14223 14224 if (auto *Ctor = dyn_cast<CXXConstructorDecl>(FD)) { 14225 if (Ctor->getTemplateSpecializationKind() == TSK_ExplicitSpecialization && 14226 Ctor->isDefaultConstructor() && 14227 Context.getTargetInfo().getCXXABI().isMicrosoft()) { 14228 // If this is an MS ABI dllexport default constructor, instantiate any 14229 // default arguments. 14230 InstantiateDefaultCtorDefaultArgs(Ctor); 14231 } 14232 } 14233 14234 // See if this is a redefinition. If 'will have body' (or similar) is already 14235 // set, then these checks were already performed when it was set. 14236 if (!FD->willHaveBody() && !FD->isLateTemplateParsed() && 14237 !FD->isThisDeclarationInstantiatedFromAFriendDefinition()) { 14238 CheckForFunctionRedefinition(FD, nullptr, SkipBody); 14239 14240 // If we're skipping the body, we're done. Don't enter the scope. 14241 if (SkipBody && SkipBody->ShouldSkip) 14242 return D; 14243 } 14244 14245 // Mark this function as "will have a body eventually". This lets users to 14246 // call e.g. isInlineDefinitionExternallyVisible while we're still parsing 14247 // this function. 14248 FD->setWillHaveBody(); 14249 14250 // If we are instantiating a generic lambda call operator, push 14251 // a LambdaScopeInfo onto the function stack. But use the information 14252 // that's already been calculated (ActOnLambdaExpr) to prime the current 14253 // LambdaScopeInfo. 14254 // When the template operator is being specialized, the LambdaScopeInfo, 14255 // has to be properly restored so that tryCaptureVariable doesn't try 14256 // and capture any new variables. In addition when calculating potential 14257 // captures during transformation of nested lambdas, it is necessary to 14258 // have the LSI properly restored. 14259 if (isGenericLambdaCallOperatorSpecialization(FD)) { 14260 assert(inTemplateInstantiation() &&((void)0) 14261 "There should be an active template instantiation on the stack "((void)0) 14262 "when instantiating a generic lambda!")((void)0); 14263 RebuildLambdaScopeInfo(cast<CXXMethodDecl>(D), *this); 14264 } else { 14265 // Enter a new function scope 14266 PushFunctionScope(); 14267 } 14268 14269 // Builtin functions cannot be defined. 14270 if (unsigned BuiltinID = FD->getBuiltinID()) { 14271 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID) && 14272 !Context.BuiltinInfo.isPredefinedRuntimeFunction(BuiltinID)) { 14273 Diag(FD->getLocation(), diag::err_builtin_definition) << FD; 14274 FD->setInvalidDecl(); 14275 } 14276 } 14277 14278 // The return type of a function definition must be complete 14279 // (C99 6.9.1p3, C++ [dcl.fct]p6). 14280 QualType ResultType = FD->getReturnType(); 14281 if (!ResultType->isDependentType() && !ResultType->isVoidType() && 14282 !FD->isInvalidDecl() && 14283 RequireCompleteType(FD->getLocation(), ResultType, 14284 diag::err_func_def_incomplete_result)) 14285 FD->setInvalidDecl(); 14286 14287 if (FnBodyScope) 14288 PushDeclContext(FnBodyScope, FD); 14289 14290 // Check the validity of our function parameters 14291 CheckParmsForFunctionDef(FD->parameters(), 14292 /*CheckParameterNames=*/true); 14293 14294 // Add non-parameter declarations already in the function to the current 14295 // scope. 14296 if (FnBodyScope) { 14297 for (Decl *NPD : FD->decls()) { 14298 auto *NonParmDecl = dyn_cast<NamedDecl>(NPD); 14299 if (!NonParmDecl) 14300 continue; 14301 assert(!isa<ParmVarDecl>(NonParmDecl) &&((void)0) 14302 "parameters should not be in newly created FD yet")((void)0); 14303 14304 // If the decl has a name, make it accessible in the current scope. 14305 if (NonParmDecl->getDeclName()) 14306 PushOnScopeChains(NonParmDecl, FnBodyScope, /*AddToContext=*/false); 14307 14308 // Similarly, dive into enums and fish their constants out, making them 14309 // accessible in this scope. 14310 if (auto *ED = dyn_cast<EnumDecl>(NonParmDecl)) { 14311 for (auto *EI : ED->enumerators()) 14312 PushOnScopeChains(EI, FnBodyScope, /*AddToContext=*/false); 14313 } 14314 } 14315 } 14316 14317 // Introduce our parameters into the function scope 14318 for (auto Param : FD->parameters()) { 14319 Param->setOwningFunction(FD); 14320 14321 // If this has an identifier, add it to the scope stack. 14322 if (Param->getIdentifier() && FnBodyScope) { 14323 CheckShadow(FnBodyScope, Param); 14324 14325 PushOnScopeChains(Param, FnBodyScope); 14326 } 14327 } 14328 14329 // Ensure that the function's exception specification is instantiated. 14330 if (const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>()) 14331 ResolveExceptionSpec(D->getLocation(), FPT); 14332 14333 // dllimport cannot be applied to non-inline function definitions. 14334 if (FD->hasAttr<DLLImportAttr>() && !FD->isInlined() && 14335 !FD->isTemplateInstantiation()) { 14336 assert(!FD->hasAttr<DLLExportAttr>())((void)0); 14337 Diag(FD->getLocation(), diag::err_attribute_dllimport_function_definition); 14338 FD->setInvalidDecl(); 14339 return D; 14340 } 14341 // We want to attach documentation to original Decl (which might be 14342 // a function template). 14343 ActOnDocumentableDecl(D); 14344 if (getCurLexicalContext()->isObjCContainer() && 14345 getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl && 14346 getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation) 14347 Diag(FD->getLocation(), diag::warn_function_def_in_objc_container); 14348 14349 return D; 14350} 14351 14352/// Given the set of return statements within a function body, 14353/// compute the variables that are subject to the named return value 14354/// optimization. 14355/// 14356/// Each of the variables that is subject to the named return value 14357/// optimization will be marked as NRVO variables in the AST, and any 14358/// return statement that has a marked NRVO variable as its NRVO candidate can 14359/// use the named return value optimization. 14360/// 14361/// This function applies a very simplistic algorithm for NRVO: if every return 14362/// statement in the scope of a variable has the same NRVO candidate, that 14363/// candidate is an NRVO variable. 14364void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) { 14365 ReturnStmt **Returns = Scope->Returns.data(); 14366 14367 for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) { 14368 if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) { 14369 if (!NRVOCandidate->isNRVOVariable()) 14370 Returns[I]->setNRVOCandidate(nullptr); 14371 } 14372 } 14373} 14374 14375bool Sema::canDelayFunctionBody(const Declarator &D) { 14376 // We can't delay parsing the body of a constexpr function template (yet). 14377 if (D.getDeclSpec().hasConstexprSpecifier()) 14378 return false; 14379 14380 // We can't delay parsing the body of a function template with a deduced 14381 // return type (yet). 14382 if (D.getDeclSpec().hasAutoTypeSpec()) { 14383 // If the placeholder introduces a non-deduced trailing return type, 14384 // we can still delay parsing it. 14385 if (D.getNumTypeObjects()) { 14386 const auto &Outer = D.getTypeObject(D.getNumTypeObjects() - 1); 14387 if (Outer.Kind == DeclaratorChunk::Function && 14388 Outer.Fun.hasTrailingReturnType()) { 14389 QualType Ty = GetTypeFromParser(Outer.Fun.getTrailingReturnType()); 14390 return Ty.isNull() || !Ty->isUndeducedType(); 14391 } 14392 } 14393 return false; 14394 } 14395 14396 return true; 14397} 14398 14399bool Sema::canSkipFunctionBody(Decl *D) { 14400 // We cannot skip the body of a function (or function template) which is 14401 // constexpr, since we may need to evaluate its body in order to parse the 14402 // rest of the file. 14403 // We cannot skip the body of a function with an undeduced return type, 14404 // because any callers of that function need to know the type. 14405 if (const FunctionDecl *FD = D->getAsFunction()) { 14406 if (FD->isConstexpr()) 14407 return false; 14408 // We can't simply call Type::isUndeducedType here, because inside template 14409 // auto can be deduced to a dependent type, which is not considered 14410 // "undeduced". 14411 if (FD->getReturnType()->getContainedDeducedType()) 14412 return false; 14413 } 14414 return Consumer.shouldSkipFunctionBody(D); 14415} 14416 14417Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) { 14418 if (!Decl) 14419 return nullptr; 14420 if (FunctionDecl *FD = Decl->getAsFunction()) 14421 FD->setHasSkippedBody(); 14422 else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Decl)) 14423 MD->setHasSkippedBody(); 14424 return Decl; 14425} 14426 14427Decl *Sema::ActOnFinishFunctionBody(Decl *D, Stmt *BodyArg) { 14428 return ActOnFinishFunctionBody(D, BodyArg, false); 14429} 14430 14431/// RAII object that pops an ExpressionEvaluationContext when exiting a function 14432/// body. 14433class ExitFunctionBodyRAII { 14434public: 14435 ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {} 14436 ~ExitFunctionBodyRAII() { 14437 if (!IsLambda) 14438 S.PopExpressionEvaluationContext(); 14439 } 14440 14441private: 14442 Sema &S; 14443 bool IsLambda = false; 14444}; 14445 14446static void diagnoseImplicitlyRetainedSelf(Sema &S) { 14447 llvm::DenseMap<const BlockDecl *, bool> EscapeInfo; 14448 14449 auto IsOrNestedInEscapingBlock = [&](const BlockDecl *BD) { 14450 if (EscapeInfo.count(BD)) 14451 return EscapeInfo[BD]; 14452 14453 bool R = false; 14454 const BlockDecl *CurBD = BD; 14455 14456 do { 14457 R = !CurBD->doesNotEscape(); 14458 if (R) 14459 break; 14460 CurBD = CurBD->getParent()->getInnermostBlockDecl(); 14461 } while (CurBD); 14462 14463 return EscapeInfo[BD] = R; 14464 }; 14465 14466 // If the location where 'self' is implicitly retained is inside a escaping 14467 // block, emit a diagnostic. 14468 for (const std::pair<SourceLocation, const BlockDecl *> &P : 14469 S.ImplicitlyRetainedSelfLocs) 14470 if (IsOrNestedInEscapingBlock(P.second)) 14471 S.Diag(P.first, diag::warn_implicitly_retains_self) 14472 << FixItHint::CreateInsertion(P.first, "self->"); 14473} 14474 14475Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body, 14476 bool IsInstantiation) { 14477 FunctionScopeInfo *FSI = getCurFunction(); 14478 FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr; 14479 14480 if (FSI->UsesFPIntrin && !FD->hasAttr<StrictFPAttr>()) 14481 FD->addAttr(StrictFPAttr::CreateImplicit(Context)); 14482 14483 sema::AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy(); 14484 sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr; 14485 14486 if (getLangOpts().Coroutines && FSI->isCoroutine()) 14487 CheckCompletedCoroutineBody(FD, Body); 14488 14489 // Do not call PopExpressionEvaluationContext() if it is a lambda because one 14490 // is already popped when finishing the lambda in BuildLambdaExpr(). This is 14491 // meant to pop the context added in ActOnStartOfFunctionDef(). 14492 ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD)); 14493 14494 if (FD) { 14495 FD->setBody(Body); 14496 FD->setWillHaveBody(false); 14497 14498 if (getLangOpts().CPlusPlus14) { 14499 if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() && 14500 FD->getReturnType()->isUndeducedType()) { 14501 // If the function has a deduced result type but contains no 'return' 14502 // statements, the result type as written must be exactly 'auto', and 14503 // the deduced result type is 'void'. 14504 if (!FD->getReturnType()->getAs<AutoType>()) { 14505 Diag(dcl->getLocation(), diag::err_auto_fn_no_return_but_not_auto) 14506 << FD->getReturnType(); 14507 FD->setInvalidDecl(); 14508 } else { 14509 // Substitute 'void' for the 'auto' in the type. 14510 TypeLoc ResultType = getReturnTypeLoc(FD); 14511 Context.adjustDeducedFunctionResultType( 14512 FD, SubstAutoType(ResultType.getType(), Context.VoidTy)); 14513 } 14514 } 14515 } else if (getLangOpts().CPlusPlus11 && isLambdaCallOperator(FD)) { 14516 // In C++11, we don't use 'auto' deduction rules for lambda call 14517 // operators because we don't support return type deduction. 14518 auto *LSI = getCurLambda(); 14519 if (LSI->HasImplicitReturnType) { 14520 deduceClosureReturnType(*LSI); 14521 14522 // C++11 [expr.prim.lambda]p4: 14523 // [...] if there are no return statements in the compound-statement 14524 // [the deduced type is] the type void 14525 QualType RetType = 14526 LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType; 14527 14528 // Update the return type to the deduced type. 14529 const auto *Proto = FD->getType()->castAs<FunctionProtoType>(); 14530 FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(), 14531 Proto->getExtProtoInfo())); 14532 } 14533 } 14534 14535 // If the function implicitly returns zero (like 'main') or is naked, 14536 // don't complain about missing return statements. 14537 if (FD->hasImplicitReturnZero() || FD->hasAttr<NakedAttr>()) 14538 WP.disableCheckFallThrough(); 14539 14540 // MSVC permits the use of pure specifier (=0) on function definition, 14541 // defined at class scope, warn about this non-standard construct. 14542 if (getLangOpts().MicrosoftExt && FD->isPure() && !FD->isOutOfLine()) 14543 Diag(FD->getLocation(), diag::ext_pure_function_definition); 14544 14545 if (!FD->isInvalidDecl()) { 14546 // Don't diagnose unused parameters of defaulted or deleted functions. 14547 if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody()) 14548 DiagnoseUnusedParameters(FD->parameters()); 14549 DiagnoseSizeOfParametersAndReturnValue(FD->parameters(), 14550 FD->getReturnType(), FD); 14551 14552 // If this is a structor, we need a vtable. 14553 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(FD)) 14554 MarkVTableUsed(FD->getLocation(), Constructor->getParent()); 14555 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(FD)) 14556 MarkVTableUsed(FD->getLocation(), Destructor->getParent()); 14557 14558 // Try to apply the named return value optimization. We have to check 14559 // if we can do this here because lambdas keep return statements around 14560 // to deduce an implicit return type. 14561 if (FD->getReturnType()->isRecordType() && 14562 (!getLangOpts().CPlusPlus || !FD->isDependentContext())) 14563 computeNRVO(Body, FSI); 14564 } 14565 14566 // GNU warning -Wmissing-prototypes: 14567 // Warn if a global function is defined without a previous 14568 // prototype declaration. This warning is issued even if the 14569 // definition itself provides a prototype. The aim is to detect 14570 // global functions that fail to be declared in header files. 14571 const FunctionDecl *PossiblePrototype = nullptr; 14572 if (ShouldWarnAboutMissingPrototype(FD, PossiblePrototype)) { 14573 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD; 14574 14575 if (PossiblePrototype) { 14576 // We found a declaration that is not a prototype, 14577 // but that could be a zero-parameter prototype 14578 if (TypeSourceInfo *TI = PossiblePrototype->getTypeSourceInfo()) { 14579 TypeLoc TL = TI->getTypeLoc(); 14580 if (FunctionNoProtoTypeLoc FTL = TL.getAs<FunctionNoProtoTypeLoc>()) 14581 Diag(PossiblePrototype->getLocation(), 14582 diag::note_declaration_not_a_prototype) 14583 << (FD->getNumParams() != 0) 14584 << (FD->getNumParams() == 0 14585 ? FixItHint::CreateInsertion(FTL.getRParenLoc(), "void") 14586 : FixItHint{}); 14587 } 14588 } else { 14589 // Returns true if the token beginning at this Loc is `const`. 14590 auto isLocAtConst = [&](SourceLocation Loc, const SourceManager &SM, 14591 const LangOptions &LangOpts) { 14592 std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc); 14593 if (LocInfo.first.isInvalid()) 14594 return false; 14595 14596 bool Invalid = false; 14597 StringRef Buffer = SM.getBufferData(LocInfo.first, &Invalid); 14598 if (Invalid) 14599 return false; 14600 14601 if (LocInfo.second > Buffer.size()) 14602 return false; 14603 14604 const char *LexStart = Buffer.data() + LocInfo.second; 14605 StringRef StartTok(LexStart, Buffer.size() - LocInfo.second); 14606 14607 return StartTok.consume_front("const") && 14608 (StartTok.empty() || isWhitespace(StartTok[0]) || 14609 StartTok.startswith("/*") || StartTok.startswith("//")); 14610 }; 14611 14612 auto findBeginLoc = [&]() { 14613 // If the return type has `const` qualifier, we want to insert 14614 // `static` before `const` (and not before the typename). 14615 if ((FD->getReturnType()->isAnyPointerType() && 14616 FD->getReturnType()->getPointeeType().isConstQualified()) || 14617 FD->getReturnType().isConstQualified()) { 14618 // But only do this if we can determine where the `const` is. 14619 14620 if (isLocAtConst(FD->getBeginLoc(), getSourceManager(), 14621 getLangOpts())) 14622 14623 return FD->getBeginLoc(); 14624 } 14625 return FD->getTypeSpecStartLoc(); 14626 }; 14627 Diag(FD->getTypeSpecStartLoc(), diag::note_static_for_internal_linkage) 14628 << /* function */ 1 14629 << (FD->getStorageClass() == SC_None 14630 ? FixItHint::CreateInsertion(findBeginLoc(), "static ") 14631 : FixItHint{}); 14632 } 14633 14634 // GNU warning -Wstrict-prototypes 14635 // Warn if K&R function is defined without a previous declaration. 14636 // This warning is issued only if the definition itself does not provide 14637 // a prototype. Only K&R definitions do not provide a prototype. 14638 if (!FD->hasWrittenPrototype()) { 14639 TypeSourceInfo *TI = FD->getTypeSourceInfo(); 14640 TypeLoc TL = TI->getTypeLoc(); 14641 FunctionTypeLoc FTL = TL.getAsAdjusted<FunctionTypeLoc>(); 14642 Diag(FTL.getLParenLoc(), diag::warn_strict_prototypes) << 2; 14643 } 14644 } 14645 14646 // Warn on CPUDispatch with an actual body. 14647 if (FD->isMultiVersion() && FD->hasAttr<CPUDispatchAttr>() && Body) 14648 if (const auto *CmpndBody = dyn_cast<CompoundStmt>(Body)) 14649 if (!CmpndBody->body_empty()) 14650 Diag(CmpndBody->body_front()->getBeginLoc(), 14651 diag::warn_dispatch_body_ignored); 14652 14653 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) { 14654 const CXXMethodDecl *KeyFunction; 14655 if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) && 14656 MD->isVirtual() && 14657 (KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) && 14658 MD == KeyFunction->getCanonicalDecl()) { 14659 // Update the key-function state if necessary for this ABI. 14660 if (FD->isInlined() && 14661 !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) { 14662 Context.setNonKeyFunction(MD); 14663 14664 // If the newly-chosen key function is already defined, then we 14665 // need to mark the vtable as used retroactively. 14666 KeyFunction = Context.getCurrentKeyFunction(MD->getParent()); 14667 const FunctionDecl *Definition; 14668 if (KeyFunction && KeyFunction->isDefined(Definition)) 14669 MarkVTableUsed(Definition->getLocation(), MD->getParent(), true); 14670 } else { 14671 // We just defined they key function; mark the vtable as used. 14672 MarkVTableUsed(FD->getLocation(), MD->getParent(), true); 14673 } 14674 } 14675 } 14676 14677 assert((FD == getCurFunctionDecl() || getCurLambda()->CallOperator == FD) &&((void)0) 14678 "Function parsing confused")((void)0); 14679 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) { 14680 assert(MD == getCurMethodDecl() && "Method parsing confused")((void)0); 14681 MD->setBody(Body); 14682 if (!MD->isInvalidDecl()) { 14683 DiagnoseSizeOfParametersAndReturnValue(MD->parameters(), 14684 MD->getReturnType(), MD); 14685 14686 if (Body) 14687 computeNRVO(Body, FSI); 14688 } 14689 if (FSI->ObjCShouldCallSuper) { 14690 Diag(MD->getEndLoc(), diag::warn_objc_missing_super_call) 14691 << MD->getSelector().getAsString(); 14692 FSI->ObjCShouldCallSuper = false; 14693 } 14694 if (FSI->ObjCWarnForNoDesignatedInitChain) { 14695 const ObjCMethodDecl *InitMethod = nullptr; 14696 bool isDesignated = 14697 MD->isDesignatedInitializerForTheInterface(&InitMethod); 14698 assert(isDesignated && InitMethod)((void)0); 14699 (void)isDesignated; 14700 14701 auto superIsNSObject = [&](const ObjCMethodDecl *MD) { 14702 auto IFace = MD->getClassInterface(); 14703 if (!IFace) 14704 return false; 14705 auto SuperD = IFace->getSuperClass(); 14706 if (!SuperD) 14707 return false; 14708 return SuperD->getIdentifier() == 14709 NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject); 14710 }; 14711 // Don't issue this warning for unavailable inits or direct subclasses 14712 // of NSObject. 14713 if (!MD->isUnavailable() && !superIsNSObject(MD)) { 14714 Diag(MD->getLocation(), 14715 diag::warn_objc_designated_init_missing_super_call); 14716 Diag(InitMethod->getLocation(), 14717 diag::note_objc_designated_init_marked_here); 14718 } 14719 FSI->ObjCWarnForNoDesignatedInitChain = false; 14720 } 14721 if (FSI->ObjCWarnForNoInitDelegation) { 14722 // Don't issue this warning for unavaialable inits. 14723 if (!MD->isUnavailable()) 14724 Diag(MD->getLocation(), 14725 diag::warn_objc_secondary_init_missing_init_call); 14726 FSI->ObjCWarnForNoInitDelegation = false; 14727 } 14728 14729 diagnoseImplicitlyRetainedSelf(*this); 14730 } else { 14731 // Parsing the function declaration failed in some way. Pop the fake scope 14732 // we pushed on. 14733 PopFunctionScopeInfo(ActivePolicy, dcl); 14734 return nullptr; 14735 } 14736 14737 if (Body && FSI->HasPotentialAvailabilityViolations) 14738 DiagnoseUnguardedAvailabilityViolations(dcl); 14739 14740 assert(!FSI->ObjCShouldCallSuper &&((void)0) 14741 "This should only be set for ObjC methods, which should have been "((void)0) 14742 "handled in the block above.")((void)0); 14743 14744 // Verify and clean out per-function state. 14745 if (Body && (!FD || !FD->isDefaulted())) { 14746 // C++ constructors that have function-try-blocks can't have return 14747 // statements in the handlers of that block. (C++ [except.handle]p14) 14748 // Verify this. 14749 if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body)) 14750 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body)); 14751 14752 // Verify that gotos and switch cases don't jump into scopes illegally. 14753 if (FSI->NeedsScopeChecking() && 14754 !PP.isCodeCompletionEnabled()) 14755 DiagnoseInvalidJumps(Body); 14756 14757 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) { 14758 if (!Destructor->getParent()->isDependentType()) 14759 CheckDestructor(Destructor); 14760 14761 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(), 14762 Destructor->getParent()); 14763 } 14764 14765 // If any errors have occurred, clear out any temporaries that may have 14766 // been leftover. This ensures that these temporaries won't be picked up for 14767 // deletion in some later function. 14768 if (hasUncompilableErrorOccurred() || 14769 getDiagnostics().getSuppressAllDiagnostics()) { 14770 DiscardCleanupsInEvaluationContext(); 14771 } 14772 if (!hasUncompilableErrorOccurred() && 14773 !isa<FunctionTemplateDecl>(dcl)) { 14774 // Since the body is valid, issue any analysis-based warnings that are 14775 // enabled. 14776 ActivePolicy = &WP; 14777 } 14778 14779 if (!IsInstantiation && FD && FD->isConstexpr() && !FD->isInvalidDecl() && 14780 !CheckConstexprFunctionDefinition(FD, CheckConstexprKind::Diagnose)) 14781 FD->setInvalidDecl(); 14782 14783 if (FD && FD->hasAttr<NakedAttr>()) { 14784 for (const Stmt *S : Body->children()) { 14785 // Allow local register variables without initializer as they don't 14786 // require prologue. 14787 bool RegisterVariables = false; 14788 if (auto *DS = dyn_cast<DeclStmt>(S)) { 14789 for (const auto *Decl : DS->decls()) { 14790 if (const auto *Var = dyn_cast<VarDecl>(Decl)) { 14791 RegisterVariables = 14792 Var->hasAttr<AsmLabelAttr>() && !Var->hasInit(); 14793 if (!RegisterVariables) 14794 break; 14795 } 14796 } 14797 } 14798 if (RegisterVariables) 14799 continue; 14800 if (!isa<AsmStmt>(S) && !isa<NullStmt>(S)) { 14801 Diag(S->getBeginLoc(), diag::err_non_asm_stmt_in_naked_function); 14802 Diag(FD->getAttr<NakedAttr>()->getLocation(), diag::note_attribute); 14803 FD->setInvalidDecl(); 14804 break; 14805 } 14806 } 14807 } 14808 14809 assert(ExprCleanupObjects.size() ==((void)0) 14810 ExprEvalContexts.back().NumCleanupObjects &&((void)0) 14811 "Leftover temporaries in function")((void)0); 14812 assert(!Cleanup.exprNeedsCleanups() && "Unaccounted cleanups in function")((void)0); 14813 assert(MaybeODRUseExprs.empty() &&((void)0) 14814 "Leftover expressions for odr-use checking")((void)0); 14815 } 14816 14817 if (!IsInstantiation) 14818 PopDeclContext(); 14819 14820 PopFunctionScopeInfo(ActivePolicy, dcl); 14821 // If any errors have occurred, clear out any temporaries that may have 14822 // been leftover. This ensures that these temporaries won't be picked up for 14823 // deletion in some later function. 14824 if (hasUncompilableErrorOccurred()) { 14825 DiscardCleanupsInEvaluationContext(); 14826 } 14827 14828 if (FD && (LangOpts.OpenMP || LangOpts.CUDA || LangOpts.SYCLIsDevice)) { 14829 auto ES = getEmissionStatus(FD); 14830 if (ES == Sema::FunctionEmissionStatus::Emitted || 14831 ES == Sema::FunctionEmissionStatus::Unknown) 14832 DeclsToCheckForDeferredDiags.insert(FD); 14833 } 14834 14835 return dcl; 14836} 14837 14838/// When we finish delayed parsing of an attribute, we must attach it to the 14839/// relevant Decl. 14840void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D, 14841 ParsedAttributes &Attrs) { 14842 // Always attach attributes to the underlying decl. 14843 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D)) 14844 D = TD->getTemplatedDecl(); 14845 ProcessDeclAttributeList(S, D, Attrs); 14846 14847 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(D)) 14848 if (Method->isStatic()) 14849 checkThisInStaticMemberFunctionAttributes(Method); 14850} 14851 14852/// ImplicitlyDefineFunction - An undeclared identifier was used in a function 14853/// call, forming a call to an implicitly defined function (per C99 6.5.1p2). 14854NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc, 14855 IdentifierInfo &II, Scope *S) { 14856 // Find the scope in which the identifier is injected and the corresponding 14857 // DeclContext. 14858 // FIXME: C89 does not say what happens if there is no enclosing block scope. 14859 // In that case, we inject the declaration into the translation unit scope 14860 // instead. 14861 Scope *BlockScope = S; 14862 while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent()) 14863 BlockScope = BlockScope->getParent(); 14864 14865 Scope *ContextScope = BlockScope; 14866 while (!ContextScope->getEntity()) 14867 ContextScope = ContextScope->getParent(); 14868 ContextRAII SavedContext(*this, ContextScope->getEntity()); 14869 14870 // Before we produce a declaration for an implicitly defined 14871 // function, see whether there was a locally-scoped declaration of 14872 // this name as a function or variable. If so, use that 14873 // (non-visible) declaration, and complain about it. 14874 NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(&II); 14875 if (ExternCPrev) { 14876 // We still need to inject the function into the enclosing block scope so 14877 // that later (non-call) uses can see it. 14878 PushOnScopeChains(ExternCPrev, BlockScope, /*AddToContext*/false); 14879 14880 // C89 footnote 38: 14881 // If in fact it is not defined as having type "function returning int", 14882 // the behavior is undefined. 14883 if (!isa<FunctionDecl>(ExternCPrev) || 14884 !Context.typesAreCompatible( 14885 cast<FunctionDecl>(ExternCPrev)->getType(), 14886 Context.getFunctionNoProtoType(Context.IntTy))) { 14887 Diag(Loc, diag::ext_use_out_of_scope_declaration) 14888 << ExternCPrev << !getLangOpts().C99; 14889 Diag(ExternCPrev->getLocation(), diag::note_previous_declaration); 14890 return ExternCPrev; 14891 } 14892 } 14893 14894 // Extension in C99. Legal in C90, but warn about it. 14895 unsigned diag_id; 14896 if (II.getName().startswith("__builtin_")) 14897 diag_id = diag::warn_builtin_unknown; 14898 // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported. 14899 else if (getLangOpts().OpenCL) 14900 diag_id = diag::err_opencl_implicit_function_decl; 14901 else if (getLangOpts().C99) 14902 diag_id = diag::ext_implicit_function_decl; 14903 else 14904 diag_id = diag::warn_implicit_function_decl; 14905 Diag(Loc, diag_id) << &II; 14906 14907 // If we found a prior declaration of this function, don't bother building 14908 // another one. We've already pushed that one into scope, so there's nothing 14909 // more to do. 14910 if (ExternCPrev) 14911 return ExternCPrev; 14912 14913 // Because typo correction is expensive, only do it if the implicit 14914 // function declaration is going to be treated as an error. 14915 if (Diags.getDiagnosticLevel(diag_id, Loc) >= DiagnosticsEngine::Error) { 14916 TypoCorrection Corrected; 14917 DeclFilterCCC<FunctionDecl> CCC{}; 14918 if (S && (Corrected = 14919 CorrectTypo(DeclarationNameInfo(&II, Loc), LookupOrdinaryName, 14920 S, nullptr, CCC, CTK_NonError))) 14921 diagnoseTypo(Corrected, PDiag(diag::note_function_suggestion), 14922 /*ErrorRecovery*/false); 14923 } 14924 14925 // Set a Declarator for the implicit definition: int foo(); 14926 const char *Dummy; 14927 AttributeFactory attrFactory; 14928 DeclSpec DS(attrFactory); 14929 unsigned DiagID; 14930 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID, 14931 Context.getPrintingPolicy()); 14932 (void)Error; // Silence warning. 14933 assert(!Error && "Error setting up implicit decl!")((void)0); 14934 SourceLocation NoLoc; 14935 Declarator D(DS, DeclaratorContext::Block); 14936 D.AddTypeInfo(DeclaratorChunk::getFunction(/*HasProto=*/false, 14937 /*IsAmbiguous=*/false, 14938 /*LParenLoc=*/NoLoc, 14939 /*Params=*/nullptr, 14940 /*NumParams=*/0, 14941 /*EllipsisLoc=*/NoLoc, 14942 /*RParenLoc=*/NoLoc, 14943 /*RefQualifierIsLvalueRef=*/true, 14944 /*RefQualifierLoc=*/NoLoc, 14945 /*MutableLoc=*/NoLoc, EST_None, 14946 /*ESpecRange=*/SourceRange(), 14947 /*Exceptions=*/nullptr, 14948 /*ExceptionRanges=*/nullptr, 14949 /*NumExceptions=*/0, 14950 /*NoexceptExpr=*/nullptr, 14951 /*ExceptionSpecTokens=*/nullptr, 14952 /*DeclsInPrototype=*/None, Loc, 14953 Loc, D), 14954 std::move(DS.getAttributes()), SourceLocation()); 14955 D.SetIdentifier(&II, Loc); 14956 14957 // Insert this function into the enclosing block scope. 14958 FunctionDecl *FD = cast<FunctionDecl>(ActOnDeclarator(BlockScope, D)); 14959 FD->setImplicit(); 14960 14961 AddKnownFunctionAttributes(FD); 14962 14963 return FD; 14964} 14965 14966/// If this function is a C++ replaceable global allocation function 14967/// (C++2a [basic.stc.dynamic.allocation], C++2a [new.delete]), 14968/// adds any function attributes that we know a priori based on the standard. 14969/// 14970/// We need to check for duplicate attributes both here and where user-written 14971/// attributes are applied to declarations. 14972void Sema::AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction( 14973 FunctionDecl *FD) { 14974 if (FD->isInvalidDecl()) 14975 return; 14976 14977 if (FD->getDeclName().getCXXOverloadedOperator() != OO_New && 14978 FD->getDeclName().getCXXOverloadedOperator() != OO_Array_New) 14979 return; 14980 14981 Optional<unsigned> AlignmentParam; 14982 bool IsNothrow = false; 14983 if (!FD->isReplaceableGlobalAllocationFunction(&AlignmentParam, &IsNothrow)) 14984 return; 14985 14986 // C++2a [basic.stc.dynamic.allocation]p4: 14987 // An allocation function that has a non-throwing exception specification 14988 // indicates failure by returning a null pointer value. Any other allocation 14989 // function never returns a null pointer value and indicates failure only by 14990 // throwing an exception [...] 14991 if (!IsNothrow && !FD->hasAttr<ReturnsNonNullAttr>()) 14992 FD->addAttr(ReturnsNonNullAttr::CreateImplicit(Context, FD->getLocation())); 14993 14994 // C++2a [basic.stc.dynamic.allocation]p2: 14995 // An allocation function attempts to allocate the requested amount of 14996 // storage. [...] If the request succeeds, the value returned by a 14997 // replaceable allocation function is a [...] pointer value p0 different 14998 // from any previously returned value p1 [...] 14999 // 15000 // However, this particular information is being added in codegen, 15001 // because there is an opt-out switch for it (-fno-assume-sane-operator-new) 15002 15003 // C++2a [basic.stc.dynamic.allocation]p2: 15004 // An allocation function attempts to allocate the requested amount of 15005 // storage. If it is successful, it returns the address of the start of a 15006 // block of storage whose length in bytes is at least as large as the 15007 // requested size. 15008 if (!FD->hasAttr<AllocSizeAttr>()) { 15009 FD->addAttr(AllocSizeAttr::CreateImplicit( 15010 Context, /*ElemSizeParam=*/ParamIdx(1, FD), 15011 /*NumElemsParam=*/ParamIdx(), FD->getLocation())); 15012 } 15013 15014 // C++2a [basic.stc.dynamic.allocation]p3: 15015 // For an allocation function [...], the pointer returned on a successful 15016 // call shall represent the address of storage that is aligned as follows: 15017 // (3.1) If the allocation function takes an argument of type 15018 // std::align_val_t, the storage will have the alignment 15019 // specified by the value of this argument. 15020 if (AlignmentParam.hasValue() && !FD->hasAttr<AllocAlignAttr>()) { 15021 FD->addAttr(AllocAlignAttr::CreateImplicit( 15022 Context, ParamIdx(AlignmentParam.getValue(), FD), FD->getLocation())); 15023 } 15024 15025 // FIXME: 15026 // C++2a [basic.stc.dynamic.allocation]p3: 15027 // For an allocation function [...], the pointer returned on a successful 15028 // call shall represent the address of storage that is aligned as follows: 15029 // (3.2) Otherwise, if the allocation function is named operator new[], 15030 // the storage is aligned for any object that does not have 15031 // new-extended alignment ([basic.align]) and is no larger than the 15032 // requested size. 15033 // (3.3) Otherwise, the storage is aligned for any object that does not 15034 // have new-extended alignment and is of the requested size. 15035} 15036 15037/// Adds any function attributes that we know a priori based on 15038/// the declaration of this function. 15039/// 15040/// These attributes can apply both to implicitly-declared builtins 15041/// (like __builtin___printf_chk) or to library-declared functions 15042/// like NSLog or printf. 15043/// 15044/// We need to check for duplicate attributes both here and where user-written 15045/// attributes are applied to declarations. 15046void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) { 15047 if (FD->isInvalidDecl()) 15048 return; 15049 15050 // If this is a built-in function, map its builtin attributes to 15051 // actual attributes. 15052 if (unsigned BuiltinID = FD->getBuiltinID()) { 15053 // Handle printf-formatting attributes. 15054 unsigned FormatIdx; 15055 bool HasVAListArg; 15056 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) { 15057 if (!FD->hasAttr<FormatAttr>()) { 15058 const char *fmt = "printf"; 15059 unsigned int NumParams = FD->getNumParams(); 15060 if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf) 15061 FD->getParamDecl(FormatIdx)->getType()->isObjCObjectPointerType()) 15062 fmt = "NSString"; 15063 FD->addAttr(FormatAttr::CreateImplicit(Context, 15064 &Context.Idents.get(fmt), 15065 FormatIdx+1, 15066 HasVAListArg ? 0 : FormatIdx+2, 15067 FD->getLocation())); 15068 } 15069 } 15070 if (Context.BuiltinInfo.isScanfLike(BuiltinID, FormatIdx, 15071 HasVAListArg)) { 15072 if (!FD->hasAttr<FormatAttr>()) 15073 FD->addAttr(FormatAttr::CreateImplicit(Context, 15074 &Context.Idents.get("scanf"), 15075 FormatIdx+1, 15076 HasVAListArg ? 0 : FormatIdx+2, 15077 FD->getLocation())); 15078 } 15079 15080 // Handle automatically recognized callbacks. 15081 SmallVector<int, 4> Encoding; 15082 if (!FD->hasAttr<CallbackAttr>() && 15083 Context.BuiltinInfo.performsCallback(BuiltinID, Encoding)) 15084 FD->addAttr(CallbackAttr::CreateImplicit( 15085 Context, Encoding.data(), Encoding.size(), FD->getLocation())); 15086 15087 // Mark const if we don't care about errno and that is the only thing 15088 // preventing the function from being const. This allows IRgen to use LLVM 15089 // intrinsics for such functions. 15090 if (!getLangOpts().MathErrno && !FD->hasAttr<ConstAttr>() && 15091 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID)) 15092 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); 15093 15094 // We make "fma" on some platforms const because we know it does not set 15095 // errno in those environments even though it could set errno based on the 15096 // C standard. 15097 const llvm::Triple &Trip = Context.getTargetInfo().getTriple(); 15098 if ((Trip.isGNUEnvironment() || Trip.isAndroid() || Trip.isOSMSVCRT()) && 15099 !FD->hasAttr<ConstAttr>()) { 15100 switch (BuiltinID) { 15101 case Builtin::BI__builtin_fma: 15102 case Builtin::BI__builtin_fmaf: 15103 case Builtin::BI__builtin_fmal: 15104 case Builtin::BIfma: 15105 case Builtin::BIfmaf: 15106 case Builtin::BIfmal: 15107 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); 15108 break; 15109 default: 15110 break; 15111 } 15112 } 15113 15114 if (Context.BuiltinInfo.isReturnsTwice(BuiltinID) && 15115 !FD->hasAttr<ReturnsTwiceAttr>()) 15116 FD->addAttr(ReturnsTwiceAttr::CreateImplicit(Context, 15117 FD->getLocation())); 15118 if (Context.BuiltinInfo.isNoThrow(BuiltinID) && !FD->hasAttr<NoThrowAttr>()) 15119 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation())); 15120 if (Context.BuiltinInfo.isPure(BuiltinID) && !FD->hasAttr<PureAttr>()) 15121 FD->addAttr(PureAttr::CreateImplicit(Context, FD->getLocation())); 15122 if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr<ConstAttr>()) 15123 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation())); 15124 if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) && 15125 !FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) { 15126 // Add the appropriate attribute, depending on the CUDA compilation mode 15127 // and which target the builtin belongs to. For example, during host 15128 // compilation, aux builtins are __device__, while the rest are __host__. 15129 if (getLangOpts().CUDAIsDevice != 15130 Context.BuiltinInfo.isAuxBuiltinID(BuiltinID)) 15131 FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation())); 15132 else 15133 FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation())); 15134 } 15135 } 15136 15137 AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction(FD); 15138 15139 // If C++ exceptions are enabled but we are told extern "C" functions cannot 15140 // throw, add an implicit nothrow attribute to any extern "C" function we come 15141 // across. 15142 if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind && 15143 FD->isExternC() && !FD->hasAttr<NoThrowAttr>()) { 15144 const auto *FPT = FD->getType()->getAs<FunctionProtoType>(); 15145 if (!FPT || FPT->getExceptionSpecType() == EST_None) 15146 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation())); 15147 } 15148 15149 IdentifierInfo *Name = FD->getIdentifier(); 15150 if (!Name) 15151 return; 15152 if ((!getLangOpts().CPlusPlus && 15153 FD->getDeclContext()->isTranslationUnit()) || 15154 (isa<LinkageSpecDecl>(FD->getDeclContext()) && 15155 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() == 15156 LinkageSpecDecl::lang_c)) { 15157 // Okay: this could be a libc/libm/Objective-C function we know 15158 // about. 15159 } else 15160 return; 15161 15162 if (Name->isStr("asprintf") || Name->isStr("vasprintf")) { 15163 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be 15164 // target-specific builtins, perhaps? 15165 if (!FD->hasAttr<FormatAttr>()) 15166 FD->addAttr(FormatAttr::CreateImplicit(Context, 15167 &Context.Idents.get("printf"), 2, 15168 Name->isStr("vasprintf") ? 0 : 3, 15169 FD->getLocation())); 15170 } 15171 15172 if (Name->isStr("__CFStringMakeConstantString")) { 15173 // We already have a __builtin___CFStringMakeConstantString, 15174 // but builds that use -fno-constant-cfstrings don't go through that. 15175 if (!FD->hasAttr<FormatArgAttr>()) 15176 FD->addAttr(FormatArgAttr::CreateImplicit(Context, ParamIdx(1, FD), 15177 FD->getLocation())); 15178 } 15179} 15180 15181TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T, 15182 TypeSourceInfo *TInfo) { 15183 assert(D.getIdentifier() && "Wrong callback for declspec without declarator")((void)0); 15184 assert(!T.isNull() && "GetTypeForDeclarator() returned null type")((void)0); 15185 15186 if (!TInfo) { 15187 assert(D.isInvalidType() && "no declarator info for valid type")((void)0); 15188 TInfo = Context.getTrivialTypeSourceInfo(T); 15189 } 15190 15191 // Scope manipulation handled by caller. 15192 TypedefDecl *NewTD = 15193 TypedefDecl::Create(Context, CurContext, D.getBeginLoc(), 15194 D.getIdentifierLoc(), D.getIdentifier(), TInfo); 15195 15196 // Bail out immediately if we have an invalid declaration. 15197 if (D.isInvalidType()) { 15198 NewTD->setInvalidDecl(); 15199 return NewTD; 15200 } 15201 15202 if (D.getDeclSpec().isModulePrivateSpecified()) { 15203 if (CurContext->isFunctionOrMethod()) 15204 Diag(NewTD->getLocation(), diag::err_module_private_local) 15205 << 2 << NewTD 15206 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc()) 15207 << FixItHint::CreateRemoval( 15208 D.getDeclSpec().getModulePrivateSpecLoc()); 15209 else 15210 NewTD->setModulePrivate(); 15211 } 15212 15213 // C++ [dcl.typedef]p8: 15214 // If the typedef declaration defines an unnamed class (or 15215 // enum), the first typedef-name declared by the declaration 15216 // to be that class type (or enum type) is used to denote the 15217 // class type (or enum type) for linkage purposes only. 15218 // We need to check whether the type was declared in the declaration. 15219 switch (D.getDeclSpec().getTypeSpecType()) { 15220 case TST_enum: 15221 case TST_struct: 15222 case TST_interface: 15223 case TST_union: 15224 case TST_class: { 15225 TagDecl *tagFromDeclSpec = cast<TagDecl>(D.getDeclSpec().getRepAsDecl()); 15226 setTagNameForLinkagePurposes(tagFromDeclSpec, NewTD); 15227 break; 15228 } 15229 15230 default: 15231 break; 15232 } 15233 15234 return NewTD; 15235} 15236 15237/// Check that this is a valid underlying type for an enum declaration. 15238bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) { 15239 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc(); 15240 QualType T = TI->getType(); 15241 15242 if (T->isDependentType()) 15243 return false; 15244 15245 // This doesn't use 'isIntegralType' despite the error message mentioning 15246 // integral type because isIntegralType would also allow enum types in C. 15247 if (const BuiltinType *BT = T->getAs<BuiltinType>()) 15248 if (BT->isInteger()) 15249 return false; 15250 15251 if (T->isExtIntType()) 15252 return false; 15253 15254 return Diag(UnderlyingLoc, diag::err_enum_invalid_underlying) << T; 15255} 15256 15257/// Check whether this is a valid redeclaration of a previous enumeration. 15258/// \return true if the redeclaration was invalid. 15259bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped, 15260 QualType EnumUnderlyingTy, bool IsFixed, 15261 const EnumDecl *Prev) { 15262 if (IsScoped != Prev->isScoped()) { 15263 Diag(EnumLoc, diag::err_enum_redeclare_scoped_mismatch) 15264 << Prev->isScoped(); 15265 Diag(Prev->getLocation(), diag::note_previous_declaration); 15266 return true; 15267 } 15268 15269 if (IsFixed && Prev->isFixed()) { 15270 if (!EnumUnderlyingTy->isDependentType() && 15271 !Prev->getIntegerType()->isDependentType() && 15272 !Context.hasSameUnqualifiedType(EnumUnderlyingTy, 15273 Prev->getIntegerType())) { 15274 // TODO: Highlight the underlying type of the redeclaration. 15275 Diag(EnumLoc, diag::err_enum_redeclare_type_mismatch) 15276 << EnumUnderlyingTy << Prev->getIntegerType(); 15277 Diag(Prev->getLocation(), diag::note_previous_declaration) 15278 << Prev->getIntegerTypeRange(); 15279 return true; 15280 } 15281 } else if (IsFixed != Prev->isFixed()) { 15282 Diag(EnumLoc, diag::err_enum_redeclare_fixed_mismatch) 15283 << Prev->isFixed(); 15284 Diag(Prev->getLocation(), diag::note_previous_declaration); 15285 return true; 15286 } 15287 15288 return false; 15289} 15290 15291/// Get diagnostic %select index for tag kind for 15292/// redeclaration diagnostic message. 15293/// WARNING: Indexes apply to particular diagnostics only! 15294/// 15295/// \returns diagnostic %select index. 15296static unsigned getRedeclDiagFromTagKind(TagTypeKind Tag) { 15297 switch (Tag) { 15298 case TTK_Struct: return 0; 15299 case TTK_Interface: return 1; 15300 case TTK_Class: return 2; 15301 default: llvm_unreachable("Invalid tag kind for redecl diagnostic!")__builtin_unreachable(); 15302 } 15303} 15304 15305/// Determine if tag kind is a class-key compatible with 15306/// class for redeclaration (class, struct, or __interface). 15307/// 15308/// \returns true iff the tag kind is compatible. 15309static bool isClassCompatTagKind(TagTypeKind Tag) 15310{ 15311 return Tag == TTK_Struct || Tag == TTK_Class || Tag == TTK_Interface; 15312} 15313 15314Sema::NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl, 15315 TagTypeKind TTK) { 15316 if (isa<TypedefDecl>(PrevDecl)) 15317 return NTK_Typedef; 15318 else if (isa<TypeAliasDecl>(PrevDecl)) 15319 return NTK_TypeAlias; 15320 else if (isa<ClassTemplateDecl>(PrevDecl)) 15321 return NTK_Template; 15322 else if (isa<TypeAliasTemplateDecl>(PrevDecl)) 15323 return NTK_TypeAliasTemplate; 15324 else if (isa<TemplateTemplateParmDecl>(PrevDecl)) 15325 return NTK_TemplateTemplateArgument; 15326 switch (TTK) { 15327 case TTK_Struct: 15328 case TTK_Interface: 15329 case TTK_Class: 15330 return getLangOpts().CPlusPlus ? NTK_NonClass : NTK_NonStruct; 15331 case TTK_Union: 15332 return NTK_NonUnion; 15333 case TTK_Enum: 15334 return NTK_NonEnum; 15335 } 15336 llvm_unreachable("invalid TTK")__builtin_unreachable(); 15337} 15338 15339/// Determine whether a tag with a given kind is acceptable 15340/// as a redeclaration of the given tag declaration. 15341/// 15342/// \returns true if the new tag kind is acceptable, false otherwise. 15343bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous, 15344 TagTypeKind NewTag, bool isDefinition, 15345 SourceLocation NewTagLoc, 15346 const IdentifierInfo *Name) { 15347 // C++ [dcl.type.elab]p3: 15348 // The class-key or enum keyword present in the 15349 // elaborated-type-specifier shall agree in kind with the 15350 // declaration to which the name in the elaborated-type-specifier 15351 // refers. This rule also applies to the form of 15352 // elaborated-type-specifier that declares a class-name or 15353 // friend class since it can be construed as referring to the 15354 // definition of the class. Thus, in any 15355 // elaborated-type-specifier, the enum keyword shall be used to 15356 // refer to an enumeration (7.2), the union class-key shall be 15357 // used to refer to a union (clause 9), and either the class or 15358 // struct class-key shall be used to refer to a class (clause 9) 15359 // declared using the class or struct class-key. 15360 TagTypeKind OldTag = Previous->getTagKind(); 15361 if (OldTag != NewTag && 15362 !(isClassCompatTagKind(OldTag) && isClassCompatTagKind(NewTag))) 15363 return false; 15364 15365 // Tags are compatible, but we might still want to warn on mismatched tags. 15366 // Non-class tags can't be mismatched at this point. 15367 if (!isClassCompatTagKind(NewTag)) 15368 return true; 15369 15370 // Declarations for which -Wmismatched-tags is disabled are entirely ignored 15371 // by our warning analysis. We don't want to warn about mismatches with (eg) 15372 // declarations in system headers that are designed to be specialized, but if 15373 // a user asks us to warn, we should warn if their code contains mismatched 15374 // declarations. 15375 auto IsIgnoredLoc = [&](SourceLocation Loc) { 15376 return getDiagnostics().isIgnored(diag::warn_struct_class_tag_mismatch, 15377 Loc); 15378 }; 15379 if (IsIgnoredLoc(NewTagLoc)) 15380 return true; 15381 15382 auto IsIgnored = [&](const TagDecl *Tag) { 15383 return IsIgnoredLoc(Tag->getLocation()); 15384 }; 15385 while (IsIgnored(Previous)) { 15386 Previous = Previous->getPreviousDecl(); 15387 if (!Previous) 15388 return true; 15389 OldTag = Previous->getTagKind(); 15390 } 15391 15392 bool isTemplate = false; 15393 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous)) 15394 isTemplate = Record->getDescribedClassTemplate(); 15395 15396 if (inTemplateInstantiation()) { 15397 if (OldTag != NewTag) { 15398 // In a template instantiation, do not offer fix-its for tag mismatches 15399 // since they usually mess up the template instead of fixing the problem. 15400 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 15401 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name 15402 << getRedeclDiagFromTagKind(OldTag); 15403 // FIXME: Note previous location? 15404 } 15405 return true; 15406 } 15407 15408 if (isDefinition) { 15409 // On definitions, check all previous tags and issue a fix-it for each 15410 // one that doesn't match the current tag. 15411 if (Previous->getDefinition()) { 15412 // Don't suggest fix-its for redefinitions. 15413 return true; 15414 } 15415 15416 bool previousMismatch = false; 15417 for (const TagDecl *I : Previous->redecls()) { 15418 if (I->getTagKind() != NewTag) { 15419 // Ignore previous declarations for which the warning was disabled. 15420 if (IsIgnored(I)) 15421 continue; 15422 15423 if (!previousMismatch) { 15424 previousMismatch = true; 15425 Diag(NewTagLoc, diag::warn_struct_class_previous_tag_mismatch) 15426 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name 15427 << getRedeclDiagFromTagKind(I->getTagKind()); 15428 } 15429 Diag(I->getInnerLocStart(), diag::note_struct_class_suggestion) 15430 << getRedeclDiagFromTagKind(NewTag) 15431 << FixItHint::CreateReplacement(I->getInnerLocStart(), 15432 TypeWithKeyword::getTagTypeKindName(NewTag)); 15433 } 15434 } 15435 return true; 15436 } 15437 15438 // Identify the prevailing tag kind: this is the kind of the definition (if 15439 // there is a non-ignored definition), or otherwise the kind of the prior 15440 // (non-ignored) declaration. 15441 const TagDecl *PrevDef = Previous->getDefinition(); 15442 if (PrevDef && IsIgnored(PrevDef)) 15443 PrevDef = nullptr; 15444 const TagDecl *Redecl = PrevDef ? PrevDef : Previous; 15445 if (Redecl->getTagKind() != NewTag) { 15446 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch) 15447 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name 15448 << getRedeclDiagFromTagKind(OldTag); 15449 Diag(Redecl->getLocation(), diag::note_previous_use); 15450 15451 // If there is a previous definition, suggest a fix-it. 15452 if (PrevDef) { 15453 Diag(NewTagLoc, diag::note_struct_class_suggestion) 15454 << getRedeclDiagFromTagKind(Redecl->getTagKind()) 15455 << FixItHint::CreateReplacement(SourceRange(NewTagLoc), 15456 TypeWithKeyword::getTagTypeKindName(Redecl->getTagKind())); 15457 } 15458 } 15459 15460 return true; 15461} 15462 15463/// Add a minimal nested name specifier fixit hint to allow lookup of a tag name 15464/// from an outer enclosing namespace or file scope inside a friend declaration. 15465/// This should provide the commented out code in the following snippet: 15466/// namespace N { 15467/// struct X; 15468/// namespace M { 15469/// struct Y { friend struct /*N::*/ X; }; 15470/// } 15471/// } 15472static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S, 15473 SourceLocation NameLoc) { 15474 // While the decl is in a namespace, do repeated lookup of that name and see 15475 // if we get the same namespace back. If we do not, continue until 15476 // translation unit scope, at which point we have a fully qualified NNS. 15477 SmallVector<IdentifierInfo *, 4> Namespaces; 15478 DeclContext *DC = ND->getDeclContext()->getRedeclContext(); 15479 for (; !DC->isTranslationUnit(); DC = DC->getParent()) { 15480 // This tag should be declared in a namespace, which can only be enclosed by 15481 // other namespaces. Bail if there's an anonymous namespace in the chain. 15482 NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(DC); 15483 if (!Namespace || Namespace->isAnonymousNamespace()) 15484 return FixItHint(); 15485 IdentifierInfo *II = Namespace->getIdentifier(); 15486 Namespaces.push_back(II); 15487 NamedDecl *Lookup = SemaRef.LookupSingleName( 15488 S, II, NameLoc, Sema::LookupNestedNameSpecifierName); 15489 if (Lookup == Namespace) 15490 break; 15491 } 15492 15493 // Once we have all the namespaces, reverse them to go outermost first, and 15494 // build an NNS. 15495 SmallString<64> Insertion; 15496 llvm::raw_svector_ostream OS(Insertion); 15497 if (DC->isTranslationUnit()) 15498 OS << "::"; 15499 std::reverse(Namespaces.begin(), Namespaces.end()); 15500 for (auto *II : Namespaces) 15501 OS << II->getName() << "::"; 15502 return FixItHint::CreateInsertion(NameLoc, Insertion); 15503} 15504 15505/// Determine whether a tag originally declared in context \p OldDC can 15506/// be redeclared with an unqualified name in \p NewDC (assuming name lookup 15507/// found a declaration in \p OldDC as a previous decl, perhaps through a 15508/// using-declaration). 15509static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC, 15510 DeclContext *NewDC) { 15511 OldDC = OldDC->getRedeclContext(); 15512 NewDC = NewDC->getRedeclContext(); 15513 15514 if (OldDC->Equals(NewDC)) 15515 return true; 15516 15517 // In MSVC mode, we allow a redeclaration if the contexts are related (either 15518 // encloses the other). 15519 if (S.getLangOpts().MSVCCompat && 15520 (OldDC->Encloses(NewDC) || NewDC->Encloses(OldDC))) 15521 return true; 15522 15523 return false; 15524} 15525 15526/// This is invoked when we see 'struct foo' or 'struct {'. In the 15527/// former case, Name will be non-null. In the later case, Name will be null. 15528/// TagSpec indicates what kind of tag this is. TUK indicates whether this is a 15529/// reference/declaration/definition of a tag. 15530/// 15531/// \param IsTypeSpecifier \c true if this is a type-specifier (or 15532/// trailing-type-specifier) other than one in an alias-declaration. 15533/// 15534/// \param SkipBody If non-null, will be set to indicate if the caller should 15535/// skip the definition of this tag and treat it as if it were a declaration. 15536Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK, 15537 SourceLocation KWLoc, CXXScopeSpec &SS, 15538 IdentifierInfo *Name, SourceLocation NameLoc, 15539 const ParsedAttributesView &Attrs, AccessSpecifier AS, 15540 SourceLocation ModulePrivateLoc, 15541 MultiTemplateParamsArg TemplateParameterLists, 15542 bool &OwnedDecl, bool &IsDependent, 15543 SourceLocation ScopedEnumKWLoc, 15544 bool ScopedEnumUsesClassTag, TypeResult UnderlyingType, 15545 bool IsTypeSpecifier, bool IsTemplateParamOrArg, 15546 SkipBodyInfo *SkipBody) { 15547 // If this is not a definition, it must have a name. 15548 IdentifierInfo *OrigName = Name; 15549 assert((Name != nullptr || TUK == TUK_Definition) &&((void)0) 15550 "Nameless record must be a definition!")((void)0); 15551 assert(TemplateParameterLists.size() == 0 || TUK != TUK_Reference)((void)0); 15552 15553 OwnedDecl = false; 15554 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 15555 bool ScopedEnum = ScopedEnumKWLoc.isValid(); 15556 15557 // FIXME: Check member specializations more carefully. 15558 bool isMemberSpecialization = false; 15559 bool Invalid = false; 15560 15561 // We only need to do this matching if we have template parameters 15562 // or a scope specifier, which also conveniently avoids this work 15563 // for non-C++ cases. 15564 if (TemplateParameterLists.size() > 0 || 15565 (SS.isNotEmpty() && TUK != TUK_Reference)) { 15566 if (TemplateParameterList *TemplateParams = 15567 MatchTemplateParametersToScopeSpecifier( 15568 KWLoc, NameLoc, SS, nullptr, TemplateParameterLists, 15569 TUK == TUK_Friend, isMemberSpecialization, Invalid)) { 15570 if (Kind == TTK_Enum) { 15571 Diag(KWLoc, diag::err_enum_template); 15572 return nullptr; 15573 } 15574 15575 if (TemplateParams->size() > 0) { 15576 // This is a declaration or definition of a class template (which may 15577 // be a member of another template). 15578 15579 if (Invalid) 15580 return nullptr; 15581 15582 OwnedDecl = false; 15583 DeclResult Result = CheckClassTemplate( 15584 S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attrs, TemplateParams, 15585 AS, ModulePrivateLoc, 15586 /*FriendLoc*/ SourceLocation(), TemplateParameterLists.size() - 1, 15587 TemplateParameterLists.data(), SkipBody); 15588 return Result.get(); 15589 } else { 15590 // The "template<>" header is extraneous. 15591 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) 15592 << TypeWithKeyword::getTagTypeKindName(Kind) << Name; 15593 isMemberSpecialization = true; 15594 } 15595 } 15596 15597 if (!TemplateParameterLists.empty() && isMemberSpecialization && 15598 CheckTemplateDeclScope(S, TemplateParameterLists.back())) 15599 return nullptr; 15600 } 15601 15602 // Figure out the underlying type if this a enum declaration. We need to do 15603 // this early, because it's needed to detect if this is an incompatible 15604 // redeclaration. 15605 llvm::PointerUnion<const Type*, TypeSourceInfo*> EnumUnderlying; 15606 bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum; 15607 15608 if (Kind == TTK_Enum) { 15609 if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) { 15610 // No underlying type explicitly specified, or we failed to parse the 15611 // type, default to int. 15612 EnumUnderlying = Context.IntTy.getTypePtr(); 15613 } else if (UnderlyingType.get()) { 15614 // C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an 15615 // integral type; any cv-qualification is ignored. 15616 TypeSourceInfo *TI = nullptr; 15617 GetTypeFromParser(UnderlyingType.get(), &TI); 15618 EnumUnderlying = TI; 15619 15620 if (CheckEnumUnderlyingType(TI)) 15621 // Recover by falling back to int. 15622 EnumUnderlying = Context.IntTy.getTypePtr(); 15623 15624 if (DiagnoseUnexpandedParameterPack(TI->getTypeLoc().getBeginLoc(), TI, 15625 UPPC_FixedUnderlyingType)) 15626 EnumUnderlying = Context.IntTy.getTypePtr(); 15627 15628 } else if (Context.getTargetInfo().getTriple().isWindowsMSVCEnvironment()) { 15629 // For MSVC ABI compatibility, unfixed enums must use an underlying type 15630 // of 'int'. However, if this is an unfixed forward declaration, don't set 15631 // the underlying type unless the user enables -fms-compatibility. This 15632 // makes unfixed forward declared enums incomplete and is more conforming. 15633 if (TUK == TUK_Definition || getLangOpts().MSVCCompat) 15634 EnumUnderlying = Context.IntTy.getTypePtr(); 15635 } 15636 } 15637 15638 DeclContext *SearchDC = CurContext; 15639 DeclContext *DC = CurContext; 15640 bool isStdBadAlloc = false; 15641 bool isStdAlignValT = false; 15642 15643 RedeclarationKind Redecl = forRedeclarationInCurContext(); 15644 if (TUK == TUK_Friend || TUK == TUK_Reference) 15645 Redecl = NotForRedeclaration; 15646 15647 /// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C 15648 /// implemented asks for structural equivalence checking, the returned decl 15649 /// here is passed back to the parser, allowing the tag body to be parsed. 15650 auto createTagFromNewDecl = [&]() -> TagDecl * { 15651 assert(!getLangOpts().CPlusPlus && "not meant for C++ usage")((void)0); 15652 // If there is an identifier, use the location of the identifier as the 15653 // location of the decl, otherwise use the location of the struct/union 15654 // keyword. 15655 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 15656 TagDecl *New = nullptr; 15657 15658 if (Kind == TTK_Enum) { 15659 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, nullptr, 15660 ScopedEnum, ScopedEnumUsesClassTag, IsFixed); 15661 // If this is an undefined enum, bail. 15662 if (TUK != TUK_Definition && !Invalid) 15663 return nullptr; 15664 if (EnumUnderlying) { 15665 EnumDecl *ED = cast<EnumDecl>(New); 15666 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo *>()) 15667 ED->setIntegerTypeSourceInfo(TI); 15668 else 15669 ED->setIntegerType(QualType(EnumUnderlying.get<const Type *>(), 0)); 15670 ED->setPromotionType(ED->getIntegerType()); 15671 } 15672 } else { // struct/union 15673 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, 15674 nullptr); 15675 } 15676 15677 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) { 15678 // Add alignment attributes if necessary; these attributes are checked 15679 // when the ASTContext lays out the structure. 15680 // 15681 // It is important for implementing the correct semantics that this 15682 // happen here (in ActOnTag). The #pragma pack stack is 15683 // maintained as a result of parser callbacks which can occur at 15684 // many points during the parsing of a struct declaration (because 15685 // the #pragma tokens are effectively skipped over during the 15686 // parsing of the struct). 15687 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) { 15688 AddAlignmentAttributesForRecord(RD); 15689 AddMsStructLayoutForRecord(RD); 15690 } 15691 } 15692 New->setLexicalDeclContext(CurContext); 15693 return New; 15694 }; 15695 15696 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl); 15697 if (Name && SS.isNotEmpty()) { 15698 // We have a nested-name tag ('struct foo::bar'). 15699 15700 // Check for invalid 'foo::'. 15701 if (SS.isInvalid()) { 15702 Name = nullptr; 15703 goto CreateNewDecl; 15704 } 15705 15706 // If this is a friend or a reference to a class in a dependent 15707 // context, don't try to make a decl for it. 15708 if (TUK == TUK_Friend || TUK == TUK_Reference) { 15709 DC = computeDeclContext(SS, false); 15710 if (!DC) { 15711 IsDependent = true; 15712 return nullptr; 15713 } 15714 } else { 15715 DC = computeDeclContext(SS, true); 15716 if (!DC) { 15717 Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec) 15718 << SS.getRange(); 15719 return nullptr; 15720 } 15721 } 15722 15723 if (RequireCompleteDeclContext(SS, DC)) 15724 return nullptr; 15725 15726 SearchDC = DC; 15727 // Look-up name inside 'foo::'. 15728 LookupQualifiedName(Previous, DC); 15729 15730 if (Previous.isAmbiguous()) 15731 return nullptr; 15732 15733 if (Previous.empty()) { 15734 // Name lookup did not find anything. However, if the 15735 // nested-name-specifier refers to the current instantiation, 15736 // and that current instantiation has any dependent base 15737 // classes, we might find something at instantiation time: treat 15738 // this as a dependent elaborated-type-specifier. 15739 // But this only makes any sense for reference-like lookups. 15740 if (Previous.wasNotFoundInCurrentInstantiation() && 15741 (TUK == TUK_Reference || TUK == TUK_Friend)) { 15742 IsDependent = true; 15743 return nullptr; 15744 } 15745 15746 // A tag 'foo::bar' must already exist. 15747 Diag(NameLoc, diag::err_not_tag_in_scope) 15748 << Kind << Name << DC << SS.getRange(); 15749 Name = nullptr; 15750 Invalid = true; 15751 goto CreateNewDecl; 15752 } 15753 } else if (Name) { 15754 // C++14 [class.mem]p14: 15755 // If T is the name of a class, then each of the following shall have a 15756 // name different from T: 15757 // -- every member of class T that is itself a type 15758 if (TUK != TUK_Reference && TUK != TUK_Friend && 15759 DiagnoseClassNameShadow(SearchDC, DeclarationNameInfo(Name, NameLoc))) 15760 return nullptr; 15761 15762 // If this is a named struct, check to see if there was a previous forward 15763 // declaration or definition. 15764 // FIXME: We're looking into outer scopes here, even when we 15765 // shouldn't be. Doing so can result in ambiguities that we 15766 // shouldn't be diagnosing. 15767 LookupName(Previous, S); 15768 15769 // When declaring or defining a tag, ignore ambiguities introduced 15770 // by types using'ed into this scope. 15771 if (Previous.isAmbiguous() && 15772 (TUK == TUK_Definition || TUK == TUK_Declaration)) { 15773 LookupResult::Filter F = Previous.makeFilter(); 15774 while (F.hasNext()) { 15775 NamedDecl *ND = F.next(); 15776 if (!ND->getDeclContext()->getRedeclContext()->Equals( 15777 SearchDC->getRedeclContext())) 15778 F.erase(); 15779 } 15780 F.done(); 15781 } 15782 15783 // C++11 [namespace.memdef]p3: 15784 // If the name in a friend declaration is neither qualified nor 15785 // a template-id and the declaration is a function or an 15786 // elaborated-type-specifier, the lookup to determine whether 15787 // the entity has been previously declared shall not consider 15788 // any scopes outside the innermost enclosing namespace. 15789 // 15790 // MSVC doesn't implement the above rule for types, so a friend tag 15791 // declaration may be a redeclaration of a type declared in an enclosing 15792 // scope. They do implement this rule for friend functions. 15793 // 15794 // Does it matter that this should be by scope instead of by 15795 // semantic context? 15796 if (!Previous.empty() && TUK == TUK_Friend) { 15797 DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext(); 15798 LookupResult::Filter F = Previous.makeFilter(); 15799 bool FriendSawTagOutsideEnclosingNamespace = false; 15800 while (F.hasNext()) { 15801 NamedDecl *ND = F.next(); 15802 DeclContext *DC = ND->getDeclContext()->getRedeclContext(); 15803 if (DC->isFileContext() && 15804 !EnclosingNS->Encloses(ND->getDeclContext())) { 15805 if (getLangOpts().MSVCCompat) 15806 FriendSawTagOutsideEnclosingNamespace = true; 15807 else 15808 F.erase(); 15809 } 15810 } 15811 F.done(); 15812 15813 // Diagnose this MSVC extension in the easy case where lookup would have 15814 // unambiguously found something outside the enclosing namespace. 15815 if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) { 15816 NamedDecl *ND = Previous.getFoundDecl(); 15817 Diag(NameLoc, diag::ext_friend_tag_redecl_outside_namespace) 15818 << createFriendTagNNSFixIt(*this, ND, S, NameLoc); 15819 } 15820 } 15821 15822 // Note: there used to be some attempt at recovery here. 15823 if (Previous.isAmbiguous()) 15824 return nullptr; 15825 15826 if (!getLangOpts().CPlusPlus && TUK != TUK_Reference) { 15827 // FIXME: This makes sure that we ignore the contexts associated 15828 // with C structs, unions, and enums when looking for a matching 15829 // tag declaration or definition. See the similar lookup tweak 15830 // in Sema::LookupName; is there a better way to deal with this? 15831 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC)) 15832 SearchDC = SearchDC->getParent(); 15833 } 15834 } 15835 15836 if (Previous.isSingleResult() && 15837 Previous.getFoundDecl()->isTemplateParameter()) { 15838 // Maybe we will complain about the shadowed template parameter. 15839 DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl()); 15840 // Just pretend that we didn't see the previous declaration. 15841 Previous.clear(); 15842 } 15843 15844 if (getLangOpts().CPlusPlus && Name && DC && StdNamespace && 15845 DC->Equals(getStdNamespace())) { 15846 if (Name->isStr("bad_alloc")) { 15847 // This is a declaration of or a reference to "std::bad_alloc". 15848 isStdBadAlloc = true; 15849 15850 // If std::bad_alloc has been implicitly declared (but made invisible to 15851 // name lookup), fill in this implicit declaration as the previous 15852 // declaration, so that the declarations get chained appropriately. 15853 if (Previous.empty() && StdBadAlloc) 15854 Previous.addDecl(getStdBadAlloc()); 15855 } else if (Name->isStr("align_val_t")) { 15856 isStdAlignValT = true; 15857 if (Previous.empty() && StdAlignValT) 15858 Previous.addDecl(getStdAlignValT()); 15859 } 15860 } 15861 15862 // If we didn't find a previous declaration, and this is a reference 15863 // (or friend reference), move to the correct scope. In C++, we 15864 // also need to do a redeclaration lookup there, just in case 15865 // there's a shadow friend decl. 15866 if (Name && Previous.empty() && 15867 (TUK == TUK_Reference || TUK == TUK_Friend || IsTemplateParamOrArg)) { 15868 if (Invalid) goto CreateNewDecl; 15869 assert(SS.isEmpty())((void)0); 15870 15871 if (TUK == TUK_Reference || IsTemplateParamOrArg) { 15872 // C++ [basic.scope.pdecl]p5: 15873 // -- for an elaborated-type-specifier of the form 15874 // 15875 // class-key identifier 15876 // 15877 // if the elaborated-type-specifier is used in the 15878 // decl-specifier-seq or parameter-declaration-clause of a 15879 // function defined in namespace scope, the identifier is 15880 // declared as a class-name in the namespace that contains 15881 // the declaration; otherwise, except as a friend 15882 // declaration, the identifier is declared in the smallest 15883 // non-class, non-function-prototype scope that contains the 15884 // declaration. 15885 // 15886 // C99 6.7.2.3p8 has a similar (but not identical!) provision for 15887 // C structs and unions. 15888 // 15889 // It is an error in C++ to declare (rather than define) an enum 15890 // type, including via an elaborated type specifier. We'll 15891 // diagnose that later; for now, declare the enum in the same 15892 // scope as we would have picked for any other tag type. 15893 // 15894 // GNU C also supports this behavior as part of its incomplete 15895 // enum types extension, while GNU C++ does not. 15896 // 15897 // Find the context where we'll be declaring the tag. 15898 // FIXME: We would like to maintain the current DeclContext as the 15899 // lexical context, 15900 SearchDC = getTagInjectionContext(SearchDC); 15901 15902 // Find the scope where we'll be declaring the tag. 15903 S = getTagInjectionScope(S, getLangOpts()); 15904 } else { 15905 assert(TUK == TUK_Friend)((void)0); 15906 // C++ [namespace.memdef]p3: 15907 // If a friend declaration in a non-local class first declares a 15908 // class or function, the friend class or function is a member of 15909 // the innermost enclosing namespace. 15910 SearchDC = SearchDC->getEnclosingNamespaceContext(); 15911 } 15912 15913 // In C++, we need to do a redeclaration lookup to properly 15914 // diagnose some problems. 15915 // FIXME: redeclaration lookup is also used (with and without C++) to find a 15916 // hidden declaration so that we don't get ambiguity errors when using a 15917 // type declared by an elaborated-type-specifier. In C that is not correct 15918 // and we should instead merge compatible types found by lookup. 15919 if (getLangOpts().CPlusPlus) { 15920 // FIXME: This can perform qualified lookups into function contexts, 15921 // which are meaningless. 15922 Previous.setRedeclarationKind(forRedeclarationInCurContext()); 15923 LookupQualifiedName(Previous, SearchDC); 15924 } else { 15925 Previous.setRedeclarationKind(forRedeclarationInCurContext()); 15926 LookupName(Previous, S); 15927 } 15928 } 15929 15930 // If we have a known previous declaration to use, then use it. 15931 if (Previous.empty() && SkipBody && SkipBody->Previous) 15932 Previous.addDecl(SkipBody->Previous); 15933 15934 if (!Previous.empty()) { 15935 NamedDecl *PrevDecl = Previous.getFoundDecl(); 15936 NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl(); 15937 15938 // It's okay to have a tag decl in the same scope as a typedef 15939 // which hides a tag decl in the same scope. Finding this 15940 // insanity with a redeclaration lookup can only actually happen 15941 // in C++. 15942 // 15943 // This is also okay for elaborated-type-specifiers, which is 15944 // technically forbidden by the current standard but which is 15945 // okay according to the likely resolution of an open issue; 15946 // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407 15947 if (getLangOpts().CPlusPlus) { 15948 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(PrevDecl)) { 15949 if (const TagType *TT = TD->getUnderlyingType()->getAs<TagType>()) { 15950 TagDecl *Tag = TT->getDecl(); 15951 if (Tag->getDeclName() == Name && 15952 Tag->getDeclContext()->getRedeclContext() 15953 ->Equals(TD->getDeclContext()->getRedeclContext())) { 15954 PrevDecl = Tag; 15955 Previous.clear(); 15956 Previous.addDecl(Tag); 15957 Previous.resolveKind(); 15958 } 15959 } 15960 } 15961 } 15962 15963 // If this is a redeclaration of a using shadow declaration, it must 15964 // declare a tag in the same context. In MSVC mode, we allow a 15965 // redefinition if either context is within the other. 15966 if (auto *Shadow = dyn_cast<UsingShadowDecl>(DirectPrevDecl)) { 15967 auto *OldTag = dyn_cast<TagDecl>(PrevDecl); 15968 if (SS.isEmpty() && TUK != TUK_Reference && TUK != TUK_Friend && 15969 isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) && 15970 !(OldTag && isAcceptableTagRedeclContext( 15971 *this, OldTag->getDeclContext(), SearchDC))) { 15972 Diag(KWLoc, diag::err_using_decl_conflict_reverse); 15973 Diag(Shadow->getTargetDecl()->getLocation(), 15974 diag::note_using_decl_target); 15975 Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl) 15976 << 0; 15977 // Recover by ignoring the old declaration. 15978 Previous.clear(); 15979 goto CreateNewDecl; 15980 } 15981 } 15982 15983 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) { 15984 // If this is a use of a previous tag, or if the tag is already declared 15985 // in the same scope (so that the definition/declaration completes or 15986 // rementions the tag), reuse the decl. 15987 if (TUK == TUK_Reference || TUK == TUK_Friend || 15988 isDeclInScope(DirectPrevDecl, SearchDC, S, 15989 SS.isNotEmpty() || isMemberSpecialization)) { 15990 // Make sure that this wasn't declared as an enum and now used as a 15991 // struct or something similar. 15992 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind, 15993 TUK == TUK_Definition, KWLoc, 15994 Name)) { 15995 bool SafeToContinue 15996 = (PrevTagDecl->getTagKind() != TTK_Enum && 15997 Kind != TTK_Enum); 15998 if (SafeToContinue) 15999 Diag(KWLoc, diag::err_use_with_wrong_tag) 16000 << Name 16001 << FixItHint::CreateReplacement(SourceRange(KWLoc), 16002 PrevTagDecl->getKindName()); 16003 else 16004 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name; 16005 Diag(PrevTagDecl->getLocation(), diag::note_previous_use); 16006 16007 if (SafeToContinue) 16008 Kind = PrevTagDecl->getTagKind(); 16009 else { 16010 // Recover by making this an anonymous redefinition. 16011 Name = nullptr; 16012 Previous.clear(); 16013 Invalid = true; 16014 } 16015 } 16016 16017 if (Kind == TTK_Enum && PrevTagDecl->getTagKind() == TTK_Enum) { 16018 const EnumDecl *PrevEnum = cast<EnumDecl>(PrevTagDecl); 16019 if (TUK == TUK_Reference || TUK == TUK_Friend) 16020 return PrevTagDecl; 16021 16022 QualType EnumUnderlyingTy; 16023 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>()) 16024 EnumUnderlyingTy = TI->getType().getUnqualifiedType(); 16025 else if (const Type *T = EnumUnderlying.dyn_cast<const Type*>()) 16026 EnumUnderlyingTy = QualType(T, 0); 16027 16028 // All conflicts with previous declarations are recovered by 16029 // returning the previous declaration, unless this is a definition, 16030 // in which case we want the caller to bail out. 16031 if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc, 16032 ScopedEnum, EnumUnderlyingTy, 16033 IsFixed, PrevEnum)) 16034 return TUK == TUK_Declaration ? PrevTagDecl : nullptr; 16035 } 16036 16037 // C++11 [class.mem]p1: 16038 // A member shall not be declared twice in the member-specification, 16039 // except that a nested class or member class template can be declared 16040 // and then later defined. 16041 if (TUK == TUK_Declaration && PrevDecl->isCXXClassMember() && 16042 S->isDeclScope(PrevDecl)) { 16043 Diag(NameLoc, diag::ext_member_redeclared); 16044 Diag(PrevTagDecl->getLocation(), diag::note_previous_declaration); 16045 } 16046 16047 if (!Invalid) { 16048 // If this is a use, just return the declaration we found, unless 16049 // we have attributes. 16050 if (TUK == TUK_Reference || TUK == TUK_Friend) { 16051 if (!Attrs.empty()) { 16052 // FIXME: Diagnose these attributes. For now, we create a new 16053 // declaration to hold them. 16054 } else if (TUK == TUK_Reference && 16055 (PrevTagDecl->getFriendObjectKind() == 16056 Decl::FOK_Undeclared || 16057 PrevDecl->getOwningModule() != getCurrentModule()) && 16058 SS.isEmpty()) { 16059 // This declaration is a reference to an existing entity, but 16060 // has different visibility from that entity: it either makes 16061 // a friend visible or it makes a type visible in a new module. 16062 // In either case, create a new declaration. We only do this if 16063 // the declaration would have meant the same thing if no prior 16064 // declaration were found, that is, if it was found in the same 16065 // scope where we would have injected a declaration. 16066 if (!getTagInjectionContext(CurContext)->getRedeclContext() 16067 ->Equals(PrevDecl->getDeclContext()->getRedeclContext())) 16068 return PrevTagDecl; 16069 // This is in the injected scope, create a new declaration in 16070 // that scope. 16071 S = getTagInjectionScope(S, getLangOpts()); 16072 } else { 16073 return PrevTagDecl; 16074 } 16075 } 16076 16077 // Diagnose attempts to redefine a tag. 16078 if (TUK == TUK_Definition) { 16079 if (NamedDecl *Def = PrevTagDecl->getDefinition()) { 16080 // If we're defining a specialization and the previous definition 16081 // is from an implicit instantiation, don't emit an error 16082 // here; we'll catch this in the general case below. 16083 bool IsExplicitSpecializationAfterInstantiation = false; 16084 if (isMemberSpecialization) { 16085 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Def)) 16086 IsExplicitSpecializationAfterInstantiation = 16087 RD->getTemplateSpecializationKind() != 16088 TSK_ExplicitSpecialization; 16089 else if (EnumDecl *ED = dyn_cast<EnumDecl>(Def)) 16090 IsExplicitSpecializationAfterInstantiation = 16091 ED->getTemplateSpecializationKind() != 16092 TSK_ExplicitSpecialization; 16093 } 16094 16095 // Note that clang allows ODR-like semantics for ObjC/C, i.e., do 16096 // not keep more that one definition around (merge them). However, 16097 // ensure the decl passes the structural compatibility check in 16098 // C11 6.2.7/1 (or 6.1.2.6/1 in C89). 16099 NamedDecl *Hidden = nullptr; 16100 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) { 16101 // There is a definition of this tag, but it is not visible. We 16102 // explicitly make use of C++'s one definition rule here, and 16103 // assume that this definition is identical to the hidden one 16104 // we already have. Make the existing definition visible and 16105 // use it in place of this one. 16106 if (!getLangOpts().CPlusPlus) { 16107 // Postpone making the old definition visible until after we 16108 // complete parsing the new one and do the structural 16109 // comparison. 16110 SkipBody->CheckSameAsPrevious = true; 16111 SkipBody->New = createTagFromNewDecl(); 16112 SkipBody->Previous = Def; 16113 return Def; 16114 } else { 16115 SkipBody->ShouldSkip = true; 16116 SkipBody->Previous = Def; 16117 makeMergedDefinitionVisible(Hidden); 16118 // Carry on and handle it like a normal definition. We'll 16119 // skip starting the definitiion later. 16120 } 16121 } else if (!IsExplicitSpecializationAfterInstantiation) { 16122 // A redeclaration in function prototype scope in C isn't 16123 // visible elsewhere, so merely issue a warning. 16124 if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope()) 16125 Diag(NameLoc, diag::warn_redefinition_in_param_list) << Name; 16126 else 16127 Diag(NameLoc, diag::err_redefinition) << Name; 16128 notePreviousDefinition(Def, 16129 NameLoc.isValid() ? NameLoc : KWLoc); 16130 // If this is a redefinition, recover by making this 16131 // struct be anonymous, which will make any later 16132 // references get the previous definition. 16133 Name = nullptr; 16134 Previous.clear(); 16135 Invalid = true; 16136 } 16137 } else { 16138 // If the type is currently being defined, complain 16139 // about a nested redefinition. 16140 auto *TD = Context.getTagDeclType(PrevTagDecl)->getAsTagDecl(); 16141 if (TD->isBeingDefined()) { 16142 Diag(NameLoc, diag::err_nested_redefinition) << Name; 16143 Diag(PrevTagDecl->getLocation(), 16144 diag::note_previous_definition); 16145 Name = nullptr; 16146 Previous.clear(); 16147 Invalid = true; 16148 } 16149 } 16150 16151 // Okay, this is definition of a previously declared or referenced 16152 // tag. We're going to create a new Decl for it. 16153 } 16154 16155 // Okay, we're going to make a redeclaration. If this is some kind 16156 // of reference, make sure we build the redeclaration in the same DC 16157 // as the original, and ignore the current access specifier. 16158 if (TUK == TUK_Friend || TUK == TUK_Reference) { 16159 SearchDC = PrevTagDecl->getDeclContext(); 16160 AS = AS_none; 16161 } 16162 } 16163 // If we get here we have (another) forward declaration or we 16164 // have a definition. Just create a new decl. 16165 16166 } else { 16167 // If we get here, this is a definition of a new tag type in a nested 16168 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a 16169 // new decl/type. We set PrevDecl to NULL so that the entities 16170 // have distinct types. 16171 Previous.clear(); 16172 } 16173 // If we get here, we're going to create a new Decl. If PrevDecl 16174 // is non-NULL, it's a definition of the tag declared by 16175 // PrevDecl. If it's NULL, we have a new definition. 16176 16177 // Otherwise, PrevDecl is not a tag, but was found with tag 16178 // lookup. This is only actually possible in C++, where a few 16179 // things like templates still live in the tag namespace. 16180 } else { 16181 // Use a better diagnostic if an elaborated-type-specifier 16182 // found the wrong kind of type on the first 16183 // (non-redeclaration) lookup. 16184 if ((TUK == TUK_Reference || TUK == TUK_Friend) && 16185 !Previous.isForRedeclaration()) { 16186 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind); 16187 Diag(NameLoc, diag::err_tag_reference_non_tag) << PrevDecl << NTK 16188 << Kind; 16189 Diag(PrevDecl->getLocation(), diag::note_declared_at); 16190 Invalid = true; 16191 16192 // Otherwise, only diagnose if the declaration is in scope. 16193 } else if (!isDeclInScope(DirectPrevDecl, SearchDC, S, 16194 SS.isNotEmpty() || isMemberSpecialization)) { 16195 // do nothing 16196 16197 // Diagnose implicit declarations introduced by elaborated types. 16198 } else if (TUK == TUK_Reference || TUK == TUK_Friend) { 16199 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind); 16200 Diag(NameLoc, diag::err_tag_reference_conflict) << NTK; 16201 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl; 16202 Invalid = true; 16203 16204 // Otherwise it's a declaration. Call out a particularly common 16205 // case here. 16206 } else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(PrevDecl)) { 16207 unsigned Kind = 0; 16208 if (isa<TypeAliasDecl>(PrevDecl)) Kind = 1; 16209 Diag(NameLoc, diag::err_tag_definition_of_typedef) 16210 << Name << Kind << TND->getUnderlyingType(); 16211 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl; 16212 Invalid = true; 16213 16214 // Otherwise, diagnose. 16215 } else { 16216 // The tag name clashes with something else in the target scope, 16217 // issue an error and recover by making this tag be anonymous. 16218 Diag(NameLoc, diag::err_redefinition_different_kind) << Name; 16219 notePreviousDefinition(PrevDecl, NameLoc); 16220 Name = nullptr; 16221 Invalid = true; 16222 } 16223 16224 // The existing declaration isn't relevant to us; we're in a 16225 // new scope, so clear out the previous declaration. 16226 Previous.clear(); 16227 } 16228 } 16229 16230CreateNewDecl: 16231 16232 TagDecl *PrevDecl = nullptr; 16233 if (Previous.isSingleResult()) 16234 PrevDecl = cast<TagDecl>(Previous.getFoundDecl()); 16235 16236 // If there is an identifier, use the location of the identifier as the 16237 // location of the decl, otherwise use the location of the struct/union 16238 // keyword. 16239 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc; 16240 16241 // Otherwise, create a new declaration. If there is a previous 16242 // declaration of the same entity, the two will be linked via 16243 // PrevDecl. 16244 TagDecl *New; 16245 16246 if (Kind == TTK_Enum) { 16247 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 16248 // enum X { A, B, C } D; D should chain to X. 16249 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, 16250 cast_or_null<EnumDecl>(PrevDecl), ScopedEnum, 16251 ScopedEnumUsesClassTag, IsFixed); 16252 16253 if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit())) 16254 StdAlignValT = cast<EnumDecl>(New); 16255 16256 // If this is an undefined enum, warn. 16257 if (TUK != TUK_Definition && !Invalid) { 16258 TagDecl *Def; 16259 if (IsFixed && cast<EnumDecl>(New)->isFixed()) { 16260 // C++0x: 7.2p2: opaque-enum-declaration. 16261 // Conflicts are diagnosed above. Do nothing. 16262 } 16263 else if (PrevDecl && (Def = cast<EnumDecl>(PrevDecl)->getDefinition())) { 16264 Diag(Loc, diag::ext_forward_ref_enum_def) 16265 << New; 16266 Diag(Def->getLocation(), diag::note_previous_definition); 16267 } else { 16268 unsigned DiagID = diag::ext_forward_ref_enum; 16269 if (getLangOpts().MSVCCompat) 16270 DiagID = diag::ext_ms_forward_ref_enum; 16271 else if (getLangOpts().CPlusPlus) 16272 DiagID = diag::err_forward_ref_enum; 16273 Diag(Loc, DiagID); 16274 } 16275 } 16276 16277 if (EnumUnderlying) { 16278 EnumDecl *ED = cast<EnumDecl>(New); 16279 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>()) 16280 ED->setIntegerTypeSourceInfo(TI); 16281 else 16282 ED->setIntegerType(QualType(EnumUnderlying.get<const Type*>(), 0)); 16283 ED->setPromotionType(ED->getIntegerType()); 16284 assert(ED->isComplete() && "enum with type should be complete")((void)0); 16285 } 16286 } else { 16287 // struct/union/class 16288 16289 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.: 16290 // struct X { int A; } D; D should chain to X. 16291 if (getLangOpts().CPlusPlus) { 16292 // FIXME: Look for a way to use RecordDecl for simple structs. 16293 New = CXXRecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, 16294 cast_or_null<CXXRecordDecl>(PrevDecl)); 16295 16296 if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit())) 16297 StdBadAlloc = cast<CXXRecordDecl>(New); 16298 } else 16299 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name, 16300 cast_or_null<RecordDecl>(PrevDecl)); 16301 } 16302 16303 // C++11 [dcl.type]p3: 16304 // A type-specifier-seq shall not define a class or enumeration [...]. 16305 if (getLangOpts().CPlusPlus && (IsTypeSpecifier || IsTemplateParamOrArg) && 16306 TUK == TUK_Definition) { 16307 Diag(New->getLocation(), diag::err_type_defined_in_type_specifier) 16308 << Context.getTagDeclType(New); 16309 Invalid = true; 16310 } 16311 16312 if (!Invalid && getLangOpts().CPlusPlus && TUK == TUK_Definition && 16313 DC->getDeclKind() == Decl::Enum) { 16314 Diag(New->getLocation(), diag::err_type_defined_in_enum) 16315 << Context.getTagDeclType(New); 16316 Invalid = true; 16317 } 16318 16319 // Maybe add qualifier info. 16320 if (SS.isNotEmpty()) { 16321 if (SS.isSet()) { 16322 // If this is either a declaration or a definition, check the 16323 // nested-name-specifier against the current context. 16324 if ((TUK == TUK_Definition || TUK == TUK_Declaration) && 16325 diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc, 16326 isMemberSpecialization)) 16327 Invalid = true; 16328 16329 New->setQualifierInfo(SS.getWithLocInContext(Context)); 16330 if (TemplateParameterLists.size() > 0) { 16331 New->setTemplateParameterListsInfo(Context, TemplateParameterLists); 16332 } 16333 } 16334 else 16335 Invalid = true; 16336 } 16337 16338 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) { 16339 // Add alignment attributes if necessary; these attributes are checked when 16340 // the ASTContext lays out the structure. 16341 // 16342 // It is important for implementing the correct semantics that this 16343 // happen here (in ActOnTag). The #pragma pack stack is 16344 // maintained as a result of parser callbacks which can occur at 16345 // many points during the parsing of a struct declaration (because 16346 // the #pragma tokens are effectively skipped over during the 16347 // parsing of the struct). 16348 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) { 16349 AddAlignmentAttributesForRecord(RD); 16350 AddMsStructLayoutForRecord(RD); 16351 } 16352 } 16353 16354 if (ModulePrivateLoc.isValid()) { 16355 if (isMemberSpecialization) 16356 Diag(New->getLocation(), diag::err_module_private_specialization) 16357 << 2 16358 << FixItHint::CreateRemoval(ModulePrivateLoc); 16359 // __module_private__ does not apply to local classes. However, we only 16360 // diagnose this as an error when the declaration specifiers are 16361 // freestanding. Here, we just ignore the __module_private__. 16362 else if (!SearchDC->isFunctionOrMethod()) 16363 New->setModulePrivate(); 16364 } 16365 16366 // If this is a specialization of a member class (of a class template), 16367 // check the specialization. 16368 if (isMemberSpecialization && CheckMemberSpecialization(New, Previous)) 16369 Invalid = true; 16370 16371 // If we're declaring or defining a tag in function prototype scope in C, 16372 // note that this type can only be used within the function and add it to 16373 // the list of decls to inject into the function definition scope. 16374 if ((Name || Kind == TTK_Enum) && 16375 getNonFieldDeclScope(S)->isFunctionPrototypeScope()) { 16376 if (getLangOpts().CPlusPlus) { 16377 // C++ [dcl.fct]p6: 16378 // Types shall not be defined in return or parameter types. 16379 if (TUK == TUK_Definition && !IsTypeSpecifier) { 16380 Diag(Loc, diag::err_type_defined_in_param_type) 16381 << Name; 16382 Invalid = true; 16383 } 16384 } else if (!PrevDecl) { 16385 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New); 16386 } 16387 } 16388 16389 if (Invalid) 16390 New->setInvalidDecl(); 16391 16392 // Set the lexical context. If the tag has a C++ scope specifier, the 16393 // lexical context will be different from the semantic context. 16394 New->setLexicalDeclContext(CurContext); 16395 16396 // Mark this as a friend decl if applicable. 16397 // In Microsoft mode, a friend declaration also acts as a forward 16398 // declaration so we always pass true to setObjectOfFriendDecl to make 16399 // the tag name visible. 16400 if (TUK == TUK_Friend) 16401 New->setObjectOfFriendDecl(getLangOpts().MSVCCompat); 16402 16403 // Set the access specifier. 16404 if (!Invalid && SearchDC->isRecord()) 16405 SetMemberAccessSpecifier(New, PrevDecl, AS); 16406 16407 if (PrevDecl) 16408 CheckRedeclarationModuleOwnership(New, PrevDecl); 16409 16410 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) 16411 New->startDefinition(); 16412 16413 ProcessDeclAttributeList(S, New, Attrs); 16414 AddPragmaAttributes(S, New); 16415 16416 // If this has an identifier, add it to the scope stack. 16417 if (TUK == TUK_Friend) { 16418 // We might be replacing an existing declaration in the lookup tables; 16419 // if so, borrow its access specifier. 16420 if (PrevDecl) 16421 New->setAccess(PrevDecl->getAccess()); 16422 16423 DeclContext *DC = New->getDeclContext()->getRedeclContext(); 16424 DC->makeDeclVisibleInContext(New); 16425 if (Name) // can be null along some error paths 16426 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 16427 PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false); 16428 } else if (Name) { 16429 S = getNonFieldDeclScope(S); 16430 PushOnScopeChains(New, S, true); 16431 } else { 16432 CurContext->addDecl(New); 16433 } 16434 16435 // If this is the C FILE type, notify the AST context. 16436 if (IdentifierInfo *II = New->getIdentifier()) 16437 if (!New->isInvalidDecl() && 16438 New->getDeclContext()->getRedeclContext()->isTranslationUnit() && 16439 II->isStr("FILE")) 16440 Context.setFILEDecl(New); 16441 16442 if (PrevDecl) 16443 mergeDeclAttributes(New, PrevDecl); 16444 16445 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(New)) 16446 inferGslOwnerPointerAttribute(CXXRD); 16447 16448 // If there's a #pragma GCC visibility in scope, set the visibility of this 16449 // record. 16450 AddPushedVisibilityAttribute(New); 16451 16452 if (isMemberSpecialization && !New->isInvalidDecl()) 16453 CompleteMemberSpecialization(New, Previous); 16454 16455 OwnedDecl = true; 16456 // In C++, don't return an invalid declaration. We can't recover well from 16457 // the cases where we make the type anonymous. 16458 if (Invalid && getLangOpts().CPlusPlus) { 16459 if (New->isBeingDefined()) 16460 if (auto RD = dyn_cast<RecordDecl>(New)) 16461 RD->completeDefinition(); 16462 return nullptr; 16463 } else if (SkipBody && SkipBody->ShouldSkip) { 16464 return SkipBody->Previous; 16465 } else { 16466 return New; 16467 } 16468} 16469 16470void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) { 16471 AdjustDeclIfTemplate(TagD); 16472 TagDecl *Tag = cast<TagDecl>(TagD); 16473 16474 // Enter the tag context. 16475 PushDeclContext(S, Tag); 16476 16477 ActOnDocumentableDecl(TagD); 16478 16479 // If there's a #pragma GCC visibility in scope, set the visibility of this 16480 // record. 16481 AddPushedVisibilityAttribute(Tag); 16482} 16483 16484bool Sema::ActOnDuplicateDefinition(DeclSpec &DS, Decl *Prev, 16485 SkipBodyInfo &SkipBody) { 16486 if (!hasStructuralCompatLayout(Prev, SkipBody.New)) 16487 return false; 16488 16489 // Make the previous decl visible. 16490 makeMergedDefinitionVisible(SkipBody.Previous); 16491 return true; 16492} 16493 16494Decl *Sema::ActOnObjCContainerStartDefinition(Decl *IDecl) { 16495 assert(isa<ObjCContainerDecl>(IDecl) &&((void)0) 16496 "ActOnObjCContainerStartDefinition - Not ObjCContainerDecl")((void)0); 16497 DeclContext *OCD = cast<DeclContext>(IDecl); 16498 assert(OCD->getLexicalParent() == CurContext &&((void)0) 16499 "The next DeclContext should be lexically contained in the current one.")((void)0); 16500 CurContext = OCD; 16501 return IDecl; 16502} 16503 16504void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD, 16505 SourceLocation FinalLoc, 16506 bool IsFinalSpelledSealed, 16507 bool IsAbstract, 16508 SourceLocation LBraceLoc) { 16509 AdjustDeclIfTemplate(TagD); 16510 CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD); 16511 16512 FieldCollector->StartClass(); 16513 16514 if (!Record->getIdentifier()) 16515 return; 16516 16517 if (IsAbstract) 16518 Record->markAbstract(); 16519 16520 if (FinalLoc.isValid()) { 16521 Record->addAttr(FinalAttr::Create( 16522 Context, FinalLoc, AttributeCommonInfo::AS_Keyword, 16523 static_cast<FinalAttr::Spelling>(IsFinalSpelledSealed))); 16524 } 16525 // C++ [class]p2: 16526 // [...] The class-name is also inserted into the scope of the 16527 // class itself; this is known as the injected-class-name. For 16528 // purposes of access checking, the injected-class-name is treated 16529 // as if it were a public member name. 16530 CXXRecordDecl *InjectedClassName = CXXRecordDecl::Create( 16531 Context, Record->getTagKind(), CurContext, Record->getBeginLoc(), 16532 Record->getLocation(), Record->getIdentifier(), 16533 /*PrevDecl=*/nullptr, 16534 /*DelayTypeCreation=*/true); 16535 Context.getTypeDeclType(InjectedClassName, Record); 16536 InjectedClassName->setImplicit(); 16537 InjectedClassName->setAccess(AS_public); 16538 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate()) 16539 InjectedClassName->setDescribedClassTemplate(Template); 16540 PushOnScopeChains(InjectedClassName, S); 16541 assert(InjectedClassName->isInjectedClassName() &&((void)0) 16542 "Broken injected-class-name")((void)0); 16543} 16544 16545void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD, 16546 SourceRange BraceRange) { 16547 AdjustDeclIfTemplate(TagD); 16548 TagDecl *Tag = cast<TagDecl>(TagD); 16549 Tag->setBraceRange(BraceRange); 16550 16551 // Make sure we "complete" the definition even it is invalid. 16552 if (Tag->isBeingDefined()) { 16553 assert(Tag->isInvalidDecl() && "We should already have completed it")((void)0); 16554 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag)) 16555 RD->completeDefinition(); 16556 } 16557 16558 if (isa<CXXRecordDecl>(Tag)) { 16559 FieldCollector->FinishClass(); 16560 } 16561 16562 // Exit this scope of this tag's definition. 16563 PopDeclContext(); 16564 16565 if (getCurLexicalContext()->isObjCContainer() && 16566 Tag->getDeclContext()->isFileContext()) 16567 Tag->setTopLevelDeclInObjCContainer(); 16568 16569 // Notify the consumer that we've defined a tag. 16570 if (!Tag->isInvalidDecl()) 16571 Consumer.HandleTagDeclDefinition(Tag); 16572} 16573 16574void Sema::ActOnObjCContainerFinishDefinition() { 16575 // Exit this scope of this interface definition. 16576 PopDeclContext(); 16577} 16578 16579void Sema::ActOnObjCTemporaryExitContainerContext(DeclContext *DC) { 16580 assert(DC == CurContext && "Mismatch of container contexts")((void)0); 16581 OriginalLexicalContext = DC; 16582 ActOnObjCContainerFinishDefinition(); 16583} 16584 16585void Sema::ActOnObjCReenterContainerContext(DeclContext *DC) { 16586 ActOnObjCContainerStartDefinition(cast<Decl>(DC)); 16587 OriginalLexicalContext = nullptr; 16588} 16589 16590void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) { 16591 AdjustDeclIfTemplate(TagD); 16592 TagDecl *Tag = cast<TagDecl>(TagD); 16593 Tag->setInvalidDecl(); 16594 16595 // Make sure we "complete" the definition even it is invalid. 16596 if (Tag->isBeingDefined()) { 16597 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag)) 16598 RD->completeDefinition(); 16599 } 16600 16601 // We're undoing ActOnTagStartDefinition here, not 16602 // ActOnStartCXXMemberDeclarations, so we don't have to mess with 16603 // the FieldCollector. 16604 16605 PopDeclContext(); 16606} 16607 16608// Note that FieldName may be null for anonymous bitfields. 16609ExprResult Sema::VerifyBitField(SourceLocation FieldLoc, 16610 IdentifierInfo *FieldName, 16611 QualType FieldTy, bool IsMsStruct, 16612 Expr *BitWidth, bool *ZeroWidth) { 16613 assert(BitWidth)((void)0); 16614 if (BitWidth->containsErrors()) 16615 return ExprError(); 16616 16617 // Default to true; that shouldn't confuse checks for emptiness 16618 if (ZeroWidth) 16619 *ZeroWidth = true; 16620 16621 // C99 6.7.2.1p4 - verify the field type. 16622 // C++ 9.6p3: A bit-field shall have integral or enumeration type. 16623 if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) { 16624 // Handle incomplete and sizeless types with a specific error. 16625 if (RequireCompleteSizedType(FieldLoc, FieldTy, 16626 diag::err_field_incomplete_or_sizeless)) 16627 return ExprError(); 16628 if (FieldName) 16629 return Diag(FieldLoc, diag::err_not_integral_type_bitfield) 16630 << FieldName << FieldTy << BitWidth->getSourceRange(); 16631 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield) 16632 << FieldTy << BitWidth->getSourceRange(); 16633 } else if (DiagnoseUnexpandedParameterPack(const_cast<Expr *>(BitWidth), 16634 UPPC_BitFieldWidth)) 16635 return ExprError(); 16636 16637 // If the bit-width is type- or value-dependent, don't try to check 16638 // it now. 16639 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent()) 16640 return BitWidth; 16641 16642 llvm::APSInt Value; 16643 ExprResult ICE = VerifyIntegerConstantExpression(BitWidth, &Value, AllowFold); 16644 if (ICE.isInvalid()) 16645 return ICE; 16646 BitWidth = ICE.get(); 16647 16648 if (Value != 0 && ZeroWidth) 16649 *ZeroWidth = false; 16650 16651 // Zero-width bitfield is ok for anonymous field. 16652 if (Value == 0 && FieldName) 16653 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName; 16654 16655 if (Value.isSigned() && Value.isNegative()) { 16656 if (FieldName) 16657 return Diag(FieldLoc, diag::err_bitfield_has_negative_width) 16658 << FieldName << toString(Value, 10); 16659 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width) 16660 << toString(Value, 10); 16661 } 16662 16663 // The size of the bit-field must not exceed our maximum permitted object 16664 // size. 16665 if (Value.getActiveBits() > ConstantArrayType::getMaxSizeBits(Context)) { 16666 return Diag(FieldLoc, diag::err_bitfield_too_wide) 16667 << !FieldName << FieldName << toString(Value, 10); 16668 } 16669 16670 if (!FieldTy->isDependentType()) { 16671 uint64_t TypeStorageSize = Context.getTypeSize(FieldTy); 16672 uint64_t TypeWidth = Context.getIntWidth(FieldTy); 16673 bool BitfieldIsOverwide = Value.ugt(TypeWidth); 16674 16675 // Over-wide bitfields are an error in C or when using the MSVC bitfield 16676 // ABI. 16677 bool CStdConstraintViolation = 16678 BitfieldIsOverwide && !getLangOpts().CPlusPlus; 16679 bool MSBitfieldViolation = 16680 Value.ugt(TypeStorageSize) && 16681 (IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft()); 16682 if (CStdConstraintViolation || MSBitfieldViolation) { 16683 unsigned DiagWidth = 16684 CStdConstraintViolation ? TypeWidth : TypeStorageSize; 16685 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width) 16686 << (bool)FieldName << FieldName << toString(Value, 10) 16687 << !CStdConstraintViolation << DiagWidth; 16688 } 16689 16690 // Warn on types where the user might conceivably expect to get all 16691 // specified bits as value bits: that's all integral types other than 16692 // 'bool'. 16693 if (BitfieldIsOverwide && !FieldTy->isBooleanType() && FieldName) { 16694 Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width) 16695 << FieldName << toString(Value, 10) 16696 << (unsigned)TypeWidth; 16697 } 16698 } 16699 16700 return BitWidth; 16701} 16702 16703/// ActOnField - Each field of a C struct/union is passed into this in order 16704/// to create a FieldDecl object for it. 16705Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart, 16706 Declarator &D, Expr *BitfieldWidth) { 16707 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD), 16708 DeclStart, D, static_cast<Expr*>(BitfieldWidth), 16709 /*InitStyle=*/ICIS_NoInit, AS_public); 16710 return Res; 16711} 16712 16713/// HandleField - Analyze a field of a C struct or a C++ data member. 16714/// 16715FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record, 16716 SourceLocation DeclStart, 16717 Declarator &D, Expr *BitWidth, 16718 InClassInitStyle InitStyle, 16719 AccessSpecifier AS) { 16720 if (D.isDecompositionDeclarator()) { 16721 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator(); 16722 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context) 16723 << Decomp.getSourceRange(); 16724 return nullptr; 16725 } 16726 16727 IdentifierInfo *II = D.getIdentifier(); 16728 SourceLocation Loc = DeclStart; 16729 if (II) Loc = D.getIdentifierLoc(); 16730 16731 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 16732 QualType T = TInfo->getType(); 16733 if (getLangOpts().CPlusPlus) { 16734 CheckExtraCXXDefaultArguments(D); 16735 16736 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, 16737 UPPC_DataMemberType)) { 16738 D.setInvalidType(); 16739 T = Context.IntTy; 16740 TInfo = Context.getTrivialTypeSourceInfo(T, Loc); 16741 } 16742 } 16743 16744 DiagnoseFunctionSpecifiers(D.getDeclSpec()); 16745 16746 if (D.getDeclSpec().isInlineSpecified()) 16747 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function) 16748 << getLangOpts().CPlusPlus17; 16749 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) 16750 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), 16751 diag::err_invalid_thread) 16752 << DeclSpec::getSpecifierName(TSCS); 16753 16754 // Check to see if this name was declared as a member previously 16755 NamedDecl *PrevDecl = nullptr; 16756 LookupResult Previous(*this, II, Loc, LookupMemberName, 16757 ForVisibleRedeclaration); 16758 LookupName(Previous, S); 16759 switch (Previous.getResultKind()) { 16760 case LookupResult::Found: 16761 case LookupResult::FoundUnresolvedValue: 16762 PrevDecl = Previous.getAsSingle<NamedDecl>(); 16763 break; 16764 16765 case LookupResult::FoundOverloaded: 16766 PrevDecl = Previous.getRepresentativeDecl(); 16767 break; 16768 16769 case LookupResult::NotFound: 16770 case LookupResult::NotFoundInCurrentInstantiation: 16771 case LookupResult::Ambiguous: 16772 break; 16773 } 16774 Previous.suppressDiagnostics(); 16775 16776 if (PrevDecl && PrevDecl->isTemplateParameter()) { 16777 // Maybe we will complain about the shadowed template parameter. 16778 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 16779 // Just pretend that we didn't see the previous declaration. 16780 PrevDecl = nullptr; 16781 } 16782 16783 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 16784 PrevDecl = nullptr; 16785 16786 bool Mutable 16787 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable); 16788 SourceLocation TSSL = D.getBeginLoc(); 16789 FieldDecl *NewFD 16790 = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, InitStyle, 16791 TSSL, AS, PrevDecl, &D); 16792 16793 if (NewFD->isInvalidDecl()) 16794 Record->setInvalidDecl(); 16795 16796 if (D.getDeclSpec().isModulePrivateSpecified()) 16797 NewFD->setModulePrivate(); 16798 16799 if (NewFD->isInvalidDecl() && PrevDecl) { 16800 // Don't introduce NewFD into scope; there's already something 16801 // with the same name in the same scope. 16802 } else if (II) { 16803 PushOnScopeChains(NewFD, S); 16804 } else 16805 Record->addDecl(NewFD); 16806 16807 return NewFD; 16808} 16809 16810/// Build a new FieldDecl and check its well-formedness. 16811/// 16812/// This routine builds a new FieldDecl given the fields name, type, 16813/// record, etc. \p PrevDecl should refer to any previous declaration 16814/// with the same name and in the same scope as the field to be 16815/// created. 16816/// 16817/// \returns a new FieldDecl. 16818/// 16819/// \todo The Declarator argument is a hack. It will be removed once 16820FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T, 16821 TypeSourceInfo *TInfo, 16822 RecordDecl *Record, SourceLocation Loc, 16823 bool Mutable, Expr *BitWidth, 16824 InClassInitStyle InitStyle, 16825 SourceLocation TSSL, 16826 AccessSpecifier AS, NamedDecl *PrevDecl, 16827 Declarator *D) { 16828 IdentifierInfo *II = Name.getAsIdentifierInfo(); 16829 bool InvalidDecl = false; 16830 if (D) InvalidDecl = D->isInvalidType(); 16831 16832 // If we receive a broken type, recover by assuming 'int' and 16833 // marking this declaration as invalid. 16834 if (T.isNull() || T->containsErrors()) { 16835 InvalidDecl = true; 16836 T = Context.IntTy; 16837 } 16838 16839 QualType EltTy = Context.getBaseElementType(T); 16840 if (!EltTy->isDependentType() && !EltTy->containsErrors()) { 16841 if (RequireCompleteSizedType(Loc, EltTy, 16842 diag::err_field_incomplete_or_sizeless)) { 16843 // Fields of incomplete type force their record to be invalid. 16844 Record->setInvalidDecl(); 16845 InvalidDecl = true; 16846 } else { 16847 NamedDecl *Def; 16848 EltTy->isIncompleteType(&Def); 16849 if (Def && Def->isInvalidDecl()) { 16850 Record->setInvalidDecl(); 16851 InvalidDecl = true; 16852 } 16853 } 16854 } 16855 16856 // TR 18037 does not allow fields to be declared with address space 16857 if (T.hasAddressSpace() || T->isDependentAddressSpaceType() || 16858 T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) { 16859 Diag(Loc, diag::err_field_with_address_space); 16860 Record->setInvalidDecl(); 16861 InvalidDecl = true; 16862 } 16863 16864 if (LangOpts.OpenCL) { 16865 // OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be 16866 // used as structure or union field: image, sampler, event or block types. 16867 if (T->isEventT() || T->isImageType() || T->isSamplerT() || 16868 T->isBlockPointerType()) { 16869 Diag(Loc, diag::err_opencl_type_struct_or_union_field) << T; 16870 Record->setInvalidDecl(); 16871 InvalidDecl = true; 16872 } 16873 // OpenCL v1.2 s6.9.c: bitfields are not supported, unless Clang extension 16874 // is enabled. 16875 if (BitWidth && !getOpenCLOptions().isAvailableOption( 16876 "__cl_clang_bitfields", LangOpts)) { 16877 Diag(Loc, diag::err_opencl_bitfields); 16878 InvalidDecl = true; 16879 } 16880 } 16881 16882 // Anonymous bit-fields cannot be cv-qualified (CWG 2229). 16883 if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth && 16884 T.hasQualifiers()) { 16885 InvalidDecl = true; 16886 Diag(Loc, diag::err_anon_bitfield_qualifiers); 16887 } 16888 16889 // C99 6.7.2.1p8: A member of a structure or union may have any type other 16890 // than a variably modified type. 16891 if (!InvalidDecl && T->isVariablyModifiedType()) { 16892 if (!tryToFixVariablyModifiedVarType( 16893 TInfo, T, Loc, diag::err_typecheck_field_variable_size)) 16894 InvalidDecl = true; 16895 } 16896 16897 // Fields can not have abstract class types 16898 if (!InvalidDecl && RequireNonAbstractType(Loc, T, 16899 diag::err_abstract_type_in_decl, 16900 AbstractFieldType)) 16901 InvalidDecl = true; 16902 16903 bool ZeroWidth = false; 16904 if (InvalidDecl) 16905 BitWidth = nullptr; 16906 // If this is declared as a bit-field, check the bit-field. 16907 if (BitWidth) { 16908 BitWidth = VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth, 16909 &ZeroWidth).get(); 16910 if (!BitWidth) { 16911 InvalidDecl = true; 16912 BitWidth = nullptr; 16913 ZeroWidth = false; 16914 } 16915 } 16916 16917 // Check that 'mutable' is consistent with the type of the declaration. 16918 if (!InvalidDecl && Mutable) { 16919 unsigned DiagID = 0; 16920 if (T->isReferenceType()) 16921 DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference 16922 : diag::err_mutable_reference; 16923 else if (T.isConstQualified()) 16924 DiagID = diag::err_mutable_const; 16925 16926 if (DiagID) { 16927 SourceLocation ErrLoc = Loc; 16928 if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid()) 16929 ErrLoc = D->getDeclSpec().getStorageClassSpecLoc(); 16930 Diag(ErrLoc, DiagID); 16931 if (DiagID != diag::ext_mutable_reference) { 16932 Mutable = false; 16933 InvalidDecl = true; 16934 } 16935 } 16936 } 16937 16938 // C++11 [class.union]p8 (DR1460): 16939 // At most one variant member of a union may have a 16940 // brace-or-equal-initializer. 16941 if (InitStyle != ICIS_NoInit) 16942 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Record), Loc); 16943 16944 FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo, 16945 BitWidth, Mutable, InitStyle); 16946 if (InvalidDecl) 16947 NewFD->setInvalidDecl(); 16948 16949 if (PrevDecl && !isa<TagDecl>(PrevDecl)) { 16950 Diag(Loc, diag::err_duplicate_member) << II; 16951 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 16952 NewFD->setInvalidDecl(); 16953 } 16954 16955 if (!InvalidDecl && getLangOpts().CPlusPlus) { 16956 if (Record->isUnion()) { 16957 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 16958 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl()); 16959 if (RDecl->getDefinition()) { 16960 // C++ [class.union]p1: An object of a class with a non-trivial 16961 // constructor, a non-trivial copy constructor, a non-trivial 16962 // destructor, or a non-trivial copy assignment operator 16963 // cannot be a member of a union, nor can an array of such 16964 // objects. 16965 if (CheckNontrivialField(NewFD)) 16966 NewFD->setInvalidDecl(); 16967 } 16968 } 16969 16970 // C++ [class.union]p1: If a union contains a member of reference type, 16971 // the program is ill-formed, except when compiling with MSVC extensions 16972 // enabled. 16973 if (EltTy->isReferenceType()) { 16974 Diag(NewFD->getLocation(), getLangOpts().MicrosoftExt ? 16975 diag::ext_union_member_of_reference_type : 16976 diag::err_union_member_of_reference_type) 16977 << NewFD->getDeclName() << EltTy; 16978 if (!getLangOpts().MicrosoftExt) 16979 NewFD->setInvalidDecl(); 16980 } 16981 } 16982 } 16983 16984 // FIXME: We need to pass in the attributes given an AST 16985 // representation, not a parser representation. 16986 if (D) { 16987 // FIXME: The current scope is almost... but not entirely... correct here. 16988 ProcessDeclAttributes(getCurScope(), NewFD, *D); 16989 16990 if (NewFD->hasAttrs()) 16991 CheckAlignasUnderalignment(NewFD); 16992 } 16993 16994 // In auto-retain/release, infer strong retension for fields of 16995 // retainable type. 16996 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewFD)) 16997 NewFD->setInvalidDecl(); 16998 16999 if (T.isObjCGCWeak()) 17000 Diag(Loc, diag::warn_attribute_weak_on_field); 17001 17002 // PPC MMA non-pointer types are not allowed as field types. 17003 if (Context.getTargetInfo().getTriple().isPPC64() && 17004 CheckPPCMMAType(T, NewFD->getLocation())) 17005 NewFD->setInvalidDecl(); 17006 17007 NewFD->setAccess(AS); 17008 return NewFD; 17009} 17010 17011bool Sema::CheckNontrivialField(FieldDecl *FD) { 17012 assert(FD)((void)0); 17013 assert(getLangOpts().CPlusPlus && "valid check only for C++")((void)0); 17014 17015 if (FD->isInvalidDecl() || FD->getType()->isDependentType()) 17016 return false; 17017 17018 QualType EltTy = Context.getBaseElementType(FD->getType()); 17019 if (const RecordType *RT = EltTy->getAs<RecordType>()) { 17020 CXXRecordDecl *RDecl = cast<CXXRecordDecl>(RT->getDecl()); 17021 if (RDecl->getDefinition()) { 17022 // We check for copy constructors before constructors 17023 // because otherwise we'll never get complaints about 17024 // copy constructors. 17025 17026 CXXSpecialMember member = CXXInvalid; 17027 // We're required to check for any non-trivial constructors. Since the 17028 // implicit default constructor is suppressed if there are any 17029 // user-declared constructors, we just need to check that there is a 17030 // trivial default constructor and a trivial copy constructor. (We don't 17031 // worry about move constructors here, since this is a C++98 check.) 17032 if (RDecl->hasNonTrivialCopyConstructor()) 17033 member = CXXCopyConstructor; 17034 else if (!RDecl->hasTrivialDefaultConstructor()) 17035 member = CXXDefaultConstructor; 17036 else if (RDecl->hasNonTrivialCopyAssignment()) 17037 member = CXXCopyAssignment; 17038 else if (RDecl->hasNonTrivialDestructor()) 17039 member = CXXDestructor; 17040 17041 if (member != CXXInvalid) { 17042 if (!getLangOpts().CPlusPlus11 && 17043 getLangOpts().ObjCAutoRefCount && RDecl->hasObjectMember()) { 17044 // Objective-C++ ARC: it is an error to have a non-trivial field of 17045 // a union. However, system headers in Objective-C programs 17046 // occasionally have Objective-C lifetime objects within unions, 17047 // and rather than cause the program to fail, we make those 17048 // members unavailable. 17049 SourceLocation Loc = FD->getLocation(); 17050 if (getSourceManager().isInSystemHeader(Loc)) { 17051 if (!FD->hasAttr<UnavailableAttr>()) 17052 FD->addAttr(UnavailableAttr::CreateImplicit(Context, "", 17053 UnavailableAttr::IR_ARCFieldWithOwnership, Loc)); 17054 return false; 17055 } 17056 } 17057 17058 Diag(FD->getLocation(), getLangOpts().CPlusPlus11 ? 17059 diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member : 17060 diag::err_illegal_union_or_anon_struct_member) 17061 << FD->getParent()->isUnion() << FD->getDeclName() << member; 17062 DiagnoseNontrivial(RDecl, member); 17063 return !getLangOpts().CPlusPlus11; 17064 } 17065 } 17066 } 17067 17068 return false; 17069} 17070 17071/// TranslateIvarVisibility - Translate visibility from a token ID to an 17072/// AST enum value. 17073static ObjCIvarDecl::AccessControl 17074TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) { 17075 switch (ivarVisibility) { 17076 default: llvm_unreachable("Unknown visitibility kind")__builtin_unreachable(); 17077 case tok::objc_private: return ObjCIvarDecl::Private; 17078 case tok::objc_public: return ObjCIvarDecl::Public; 17079 case tok::objc_protected: return ObjCIvarDecl::Protected; 17080 case tok::objc_package: return ObjCIvarDecl::Package; 17081 } 17082} 17083 17084/// ActOnIvar - Each ivar field of an objective-c class is passed into this 17085/// in order to create an IvarDecl object for it. 17086Decl *Sema::ActOnIvar(Scope *S, 17087 SourceLocation DeclStart, 17088 Declarator &D, Expr *BitfieldWidth, 17089 tok::ObjCKeywordKind Visibility) { 17090 17091 IdentifierInfo *II = D.getIdentifier(); 17092 Expr *BitWidth = (Expr*)BitfieldWidth; 17093 SourceLocation Loc = DeclStart; 17094 if (II) Loc = D.getIdentifierLoc(); 17095 17096 // FIXME: Unnamed fields can be handled in various different ways, for 17097 // example, unnamed unions inject all members into the struct namespace! 17098 17099 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 17100 QualType T = TInfo->getType(); 17101 17102 if (BitWidth) { 17103 // 6.7.2.1p3, 6.7.2.1p4 17104 BitWidth = VerifyBitField(Loc, II, T, /*IsMsStruct*/false, BitWidth).get(); 17105 if (!BitWidth) 17106 D.setInvalidType(); 17107 } else { 17108 // Not a bitfield. 17109 17110 // validate II. 17111 17112 } 17113 if (T->isReferenceType()) { 17114 Diag(Loc, diag::err_ivar_reference_type); 17115 D.setInvalidType(); 17116 } 17117 // C99 6.7.2.1p8: A member of a structure or union may have any type other 17118 // than a variably modified type. 17119 else if (T->isVariablyModifiedType()) { 17120 if (!tryToFixVariablyModifiedVarType( 17121 TInfo, T, Loc, diag::err_typecheck_ivar_variable_size)) 17122 D.setInvalidType(); 17123 } 17124 17125 // Get the visibility (access control) for this ivar. 17126 ObjCIvarDecl::AccessControl ac = 17127 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility) 17128 : ObjCIvarDecl::None; 17129 // Must set ivar's DeclContext to its enclosing interface. 17130 ObjCContainerDecl *EnclosingDecl = cast<ObjCContainerDecl>(CurContext); 17131 if (!EnclosingDecl || EnclosingDecl->isInvalidDecl()) 17132 return nullptr; 17133 ObjCContainerDecl *EnclosingContext; 17134 if (ObjCImplementationDecl *IMPDecl = 17135 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 17136 if (LangOpts.ObjCRuntime.isFragile()) { 17137 // Case of ivar declared in an implementation. Context is that of its class. 17138 EnclosingContext = IMPDecl->getClassInterface(); 17139 assert(EnclosingContext && "Implementation has no class interface!")((void)0); 17140 } 17141 else 17142 EnclosingContext = EnclosingDecl; 17143 } else { 17144 if (ObjCCategoryDecl *CDecl = 17145 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) { 17146 if (LangOpts.ObjCRuntime.isFragile() || !CDecl->IsClassExtension()) { 17147 Diag(Loc, diag::err_misplaced_ivar) << CDecl->IsClassExtension(); 17148 return nullptr; 17149 } 17150 } 17151 EnclosingContext = EnclosingDecl; 17152 } 17153 17154 // Construct the decl. 17155 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, EnclosingContext, 17156 DeclStart, Loc, II, T, 17157 TInfo, ac, (Expr *)BitfieldWidth); 17158 17159 if (II) { 17160 NamedDecl *PrevDecl = LookupSingleName(S, II, Loc, LookupMemberName, 17161 ForVisibleRedeclaration); 17162 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S) 17163 && !isa<TagDecl>(PrevDecl)) { 17164 Diag(Loc, diag::err_duplicate_member) << II; 17165 Diag(PrevDecl->getLocation(), diag::note_previous_declaration); 17166 NewID->setInvalidDecl(); 17167 } 17168 } 17169 17170 // Process attributes attached to the ivar. 17171 ProcessDeclAttributes(S, NewID, D); 17172 17173 if (D.isInvalidType()) 17174 NewID->setInvalidDecl(); 17175 17176 // In ARC, infer 'retaining' for ivars of retainable type. 17177 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewID)) 17178 NewID->setInvalidDecl(); 17179 17180 if (D.getDeclSpec().isModulePrivateSpecified()) 17181 NewID->setModulePrivate(); 17182 17183 if (II) { 17184 // FIXME: When interfaces are DeclContexts, we'll need to add 17185 // these to the interface. 17186 S->AddDecl(NewID); 17187 IdResolver.AddDecl(NewID); 17188 } 17189 17190 if (LangOpts.ObjCRuntime.isNonFragile() && 17191 !NewID->isInvalidDecl() && isa<ObjCInterfaceDecl>(EnclosingDecl)) 17192 Diag(Loc, diag::warn_ivars_in_interface); 17193 17194 return NewID; 17195} 17196 17197/// ActOnLastBitfield - This routine handles synthesized bitfields rules for 17198/// class and class extensions. For every class \@interface and class 17199/// extension \@interface, if the last ivar is a bitfield of any type, 17200/// then add an implicit `char :0` ivar to the end of that interface. 17201void Sema::ActOnLastBitfield(SourceLocation DeclLoc, 17202 SmallVectorImpl<Decl *> &AllIvarDecls) { 17203 if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty()) 17204 return; 17205 17206 Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1]; 17207 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(ivarDecl); 17208 17209 if (!Ivar->isBitField() || Ivar->isZeroLengthBitField(Context)) 17210 return; 17211 ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CurContext); 17212 if (!ID) { 17213 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(CurContext)) { 17214 if (!CD->IsClassExtension()) 17215 return; 17216 } 17217 // No need to add this to end of @implementation. 17218 else 17219 return; 17220 } 17221 // All conditions are met. Add a new bitfield to the tail end of ivars. 17222 llvm::APInt Zero(Context.getTypeSize(Context.IntTy), 0); 17223 Expr * BW = IntegerLiteral::Create(Context, Zero, Context.IntTy, DeclLoc); 17224 17225 Ivar = ObjCIvarDecl::Create(Context, cast<ObjCContainerDecl>(CurContext), 17226 DeclLoc, DeclLoc, nullptr, 17227 Context.CharTy, 17228 Context.getTrivialTypeSourceInfo(Context.CharTy, 17229 DeclLoc), 17230 ObjCIvarDecl::Private, BW, 17231 true); 17232 AllIvarDecls.push_back(Ivar); 17233} 17234 17235void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl, 17236 ArrayRef<Decl *> Fields, SourceLocation LBrac, 17237 SourceLocation RBrac, 17238 const ParsedAttributesView &Attrs) { 17239 assert(EnclosingDecl && "missing record or interface decl")((void)0); 17240 17241 // If this is an Objective-C @implementation or category and we have 17242 // new fields here we should reset the layout of the interface since 17243 // it will now change. 17244 if (!Fields.empty() && isa<ObjCContainerDecl>(EnclosingDecl)) { 17245 ObjCContainerDecl *DC = cast<ObjCContainerDecl>(EnclosingDecl); 17246 switch (DC->getKind()) { 17247 default: break; 17248 case Decl::ObjCCategory: 17249 Context.ResetObjCLayout(cast<ObjCCategoryDecl>(DC)->getClassInterface()); 17250 break; 17251 case Decl::ObjCImplementation: 17252 Context. 17253 ResetObjCLayout(cast<ObjCImplementationDecl>(DC)->getClassInterface()); 17254 break; 17255 } 17256 } 17257 17258 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl); 17259 CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(EnclosingDecl); 17260 17261 // Start counting up the number of named members; make sure to include 17262 // members of anonymous structs and unions in the total. 17263 unsigned NumNamedMembers = 0; 17264 if (Record) { 17265 for (const auto *I : Record->decls()) { 17266 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I)) 17267 if (IFD->getDeclName()) 17268 ++NumNamedMembers; 17269 } 17270 } 17271 17272 // Verify that all the fields are okay. 17273 SmallVector<FieldDecl*, 32> RecFields; 17274 17275 for (ArrayRef<Decl *>::iterator i = Fields.begin(), end = Fields.end(); 17276 i != end; ++i) { 17277 FieldDecl *FD = cast<FieldDecl>(*i); 17278 17279 // Get the type for the field. 17280 const Type *FDTy = FD->getType().getTypePtr(); 17281 17282 if (!FD->isAnonymousStructOrUnion()) { 17283 // Remember all fields written by the user. 17284 RecFields.push_back(FD); 17285 } 17286 17287 // If the field is already invalid for some reason, don't emit more 17288 // diagnostics about it. 17289 if (FD->isInvalidDecl()) { 17290 EnclosingDecl->setInvalidDecl(); 17291 continue; 17292 } 17293 17294 // C99 6.7.2.1p2: 17295 // A structure or union shall not contain a member with 17296 // incomplete or function type (hence, a structure shall not 17297 // contain an instance of itself, but may contain a pointer to 17298 // an instance of itself), except that the last member of a 17299 // structure with more than one named member may have incomplete 17300 // array type; such a structure (and any union containing, 17301 // possibly recursively, a member that is such a structure) 17302 // shall not be a member of a structure or an element of an 17303 // array. 17304 bool IsLastField = (i + 1 == Fields.end()); 17305 if (FDTy->isFunctionType()) { 17306 // Field declared as a function. 17307 Diag(FD->getLocation(), diag::err_field_declared_as_function) 17308 << FD->getDeclName(); 17309 FD->setInvalidDecl(); 17310 EnclosingDecl->setInvalidDecl(); 17311 continue; 17312 } else if (FDTy->isIncompleteArrayType() && 17313 (Record || isa<ObjCContainerDecl>(EnclosingDecl))) { 17314 if (Record) { 17315 // Flexible array member. 17316 // Microsoft and g++ is more permissive regarding flexible array. 17317 // It will accept flexible array in union and also 17318 // as the sole element of a struct/class. 17319 unsigned DiagID = 0; 17320 if (!Record->isUnion() && !IsLastField) { 17321 Diag(FD->getLocation(), diag::err_flexible_array_not_at_end) 17322 << FD->getDeclName() << FD->getType() << Record->getTagKind(); 17323 Diag((*(i + 1))->getLocation(), diag::note_next_field_declaration); 17324 FD->setInvalidDecl(); 17325 EnclosingDecl->setInvalidDecl(); 17326 continue; 17327 } else if (Record->isUnion()) 17328 DiagID = getLangOpts().MicrosoftExt 17329 ? diag::ext_flexible_array_union_ms 17330 : getLangOpts().CPlusPlus 17331 ? diag::ext_flexible_array_union_gnu 17332 : diag::err_flexible_array_union; 17333 else if (NumNamedMembers < 1) 17334 DiagID = getLangOpts().MicrosoftExt 17335 ? diag::ext_flexible_array_empty_aggregate_ms 17336 : getLangOpts().CPlusPlus 17337 ? diag::ext_flexible_array_empty_aggregate_gnu 17338 : diag::err_flexible_array_empty_aggregate; 17339 17340 if (DiagID) 17341 Diag(FD->getLocation(), DiagID) << FD->getDeclName() 17342 << Record->getTagKind(); 17343 // While the layout of types that contain virtual bases is not specified 17344 // by the C++ standard, both the Itanium and Microsoft C++ ABIs place 17345 // virtual bases after the derived members. This would make a flexible 17346 // array member declared at the end of an object not adjacent to the end 17347 // of the type. 17348 if (CXXRecord && CXXRecord->getNumVBases() != 0) 17349 Diag(FD->getLocation(), diag::err_flexible_array_virtual_base) 17350 << FD->getDeclName() << Record->getTagKind(); 17351 if (!getLangOpts().C99) 17352 Diag(FD->getLocation(), diag::ext_c99_flexible_array_member) 17353 << FD->getDeclName() << Record->getTagKind(); 17354 17355 // If the element type has a non-trivial destructor, we would not 17356 // implicitly destroy the elements, so disallow it for now. 17357 // 17358 // FIXME: GCC allows this. We should probably either implicitly delete 17359 // the destructor of the containing class, or just allow this. 17360 QualType BaseElem = Context.getBaseElementType(FD->getType()); 17361 if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) { 17362 Diag(FD->getLocation(), diag::err_flexible_array_has_nontrivial_dtor) 17363 << FD->getDeclName() << FD->getType(); 17364 FD->setInvalidDecl(); 17365 EnclosingDecl->setInvalidDecl(); 17366 continue; 17367 } 17368 // Okay, we have a legal flexible array member at the end of the struct. 17369 Record->setHasFlexibleArrayMember(true); 17370 } else { 17371 // In ObjCContainerDecl ivars with incomplete array type are accepted, 17372 // unless they are followed by another ivar. That check is done 17373 // elsewhere, after synthesized ivars are known. 17374 } 17375 } else if (!FDTy->isDependentType() && 17376 RequireCompleteSizedType( 17377 FD->getLocation(), FD->getType(), 17378 diag::err_field_incomplete_or_sizeless)) { 17379 // Incomplete type 17380 FD->setInvalidDecl(); 17381 EnclosingDecl->setInvalidDecl(); 17382 continue; 17383 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) { 17384 if (Record && FDTTy->getDecl()->hasFlexibleArrayMember()) { 17385 // A type which contains a flexible array member is considered to be a 17386 // flexible array member. 17387 Record->setHasFlexibleArrayMember(true); 17388 if (!Record->isUnion()) { 17389 // If this is a struct/class and this is not the last element, reject 17390 // it. Note that GCC supports variable sized arrays in the middle of 17391 // structures. 17392 if (!IsLastField) 17393 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct) 17394 << FD->getDeclName() << FD->getType(); 17395 else { 17396 // We support flexible arrays at the end of structs in 17397 // other structs as an extension. 17398 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct) 17399 << FD->getDeclName(); 17400 } 17401 } 17402 } 17403 if (isa<ObjCContainerDecl>(EnclosingDecl) && 17404 RequireNonAbstractType(FD->getLocation(), FD->getType(), 17405 diag::err_abstract_type_in_decl, 17406 AbstractIvarType)) { 17407 // Ivars can not have abstract class types 17408 FD->setInvalidDecl(); 17409 } 17410 if (Record && FDTTy->getDecl()->hasObjectMember()) 17411 Record->setHasObjectMember(true); 17412 if (Record && FDTTy->getDecl()->hasVolatileMember()) 17413 Record->setHasVolatileMember(true); 17414 } else if (FDTy->isObjCObjectType()) { 17415 /// A field cannot be an Objective-c object 17416 Diag(FD->getLocation(), diag::err_statically_allocated_object) 17417 << FixItHint::CreateInsertion(FD->getLocation(), "*"); 17418 QualType T = Context.getObjCObjectPointerType(FD->getType()); 17419 FD->setType(T); 17420 } else if (Record && Record->isUnion() && 17421 FD->getType().hasNonTrivialObjCLifetime() && 17422 getSourceManager().isInSystemHeader(FD->getLocation()) && 17423 !getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>() && 17424 (FD->getType().getObjCLifetime() != Qualifiers::OCL_Strong || 17425 !Context.hasDirectOwnershipQualifier(FD->getType()))) { 17426 // For backward compatibility, fields of C unions declared in system 17427 // headers that have non-trivial ObjC ownership qualifications are marked 17428 // as unavailable unless the qualifier is explicit and __strong. This can 17429 // break ABI compatibility between programs compiled with ARC and MRR, but 17430 // is a better option than rejecting programs using those unions under 17431 // ARC. 17432 FD->addAttr(UnavailableAttr::CreateImplicit( 17433 Context, "", UnavailableAttr::IR_ARCFieldWithOwnership, 17434 FD->getLocation())); 17435 } else if (getLangOpts().ObjC && 17436 getLangOpts().getGC() != LangOptions::NonGC && Record && 17437 !Record->hasObjectMember()) { 17438 if (FD->getType()->isObjCObjectPointerType() || 17439 FD->getType().isObjCGCStrong()) 17440 Record->setHasObjectMember(true); 17441 else if (Context.getAsArrayType(FD->getType())) { 17442 QualType BaseType = Context.getBaseElementType(FD->getType()); 17443 if (BaseType->isRecordType() && 17444 BaseType->castAs<RecordType>()->getDecl()->hasObjectMember()) 17445 Record->setHasObjectMember(true); 17446 else if (BaseType->isObjCObjectPointerType() || 17447 BaseType.isObjCGCStrong()) 17448 Record->setHasObjectMember(true); 17449 } 17450 } 17451 17452 if (Record && !getLangOpts().CPlusPlus && 17453 !shouldIgnoreForRecordTriviality(FD)) { 17454 QualType FT = FD->getType(); 17455 if (FT.isNonTrivialToPrimitiveDefaultInitialize()) { 17456 Record->setNonTrivialToPrimitiveDefaultInitialize(true); 17457 if (FT.hasNonTrivialToPrimitiveDefaultInitializeCUnion() || 17458 Record->isUnion()) 17459 Record->setHasNonTrivialToPrimitiveDefaultInitializeCUnion(true); 17460 } 17461 QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy(); 17462 if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial) { 17463 Record->setNonTrivialToPrimitiveCopy(true); 17464 if (FT.hasNonTrivialToPrimitiveCopyCUnion() || Record->isUnion()) 17465 Record->setHasNonTrivialToPrimitiveCopyCUnion(true); 17466 } 17467 if (FT.isDestructedType()) { 17468 Record->setNonTrivialToPrimitiveDestroy(true); 17469 Record->setParamDestroyedInCallee(true); 17470 if (FT.hasNonTrivialToPrimitiveDestructCUnion() || Record->isUnion()) 17471 Record->setHasNonTrivialToPrimitiveDestructCUnion(true); 17472 } 17473 17474 if (const auto *RT = FT->getAs<RecordType>()) { 17475 if (RT->getDecl()->getArgPassingRestrictions() == 17476 RecordDecl::APK_CanNeverPassInRegs) 17477 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs); 17478 } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak) 17479 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs); 17480 } 17481 17482 if (Record && FD->getType().isVolatileQualified()) 17483 Record->setHasVolatileMember(true); 17484 // Keep track of the number of named members. 17485 if (FD->getIdentifier()) 17486 ++NumNamedMembers; 17487 } 17488 17489 // Okay, we successfully defined 'Record'. 17490 if (Record) { 17491 bool Completed = false; 17492 if (CXXRecord) { 17493 if (!CXXRecord->isInvalidDecl()) { 17494 // Set access bits correctly on the directly-declared conversions. 17495 for (CXXRecordDecl::conversion_iterator 17496 I = CXXRecord->conversion_begin(), 17497 E = CXXRecord->conversion_end(); I != E; ++I) 17498 I.setAccess((*I)->getAccess()); 17499 } 17500 17501 // Add any implicitly-declared members to this class. 17502 AddImplicitlyDeclaredMembersToClass(CXXRecord); 17503 17504 if (!CXXRecord->isDependentType()) { 17505 if (!CXXRecord->isInvalidDecl()) { 17506 // If we have virtual base classes, we may end up finding multiple 17507 // final overriders for a given virtual function. Check for this 17508 // problem now. 17509 if (CXXRecord->getNumVBases()) { 17510 CXXFinalOverriderMap FinalOverriders; 17511 CXXRecord->getFinalOverriders(FinalOverriders); 17512 17513 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), 17514 MEnd = FinalOverriders.end(); 17515 M != MEnd; ++M) { 17516 for (OverridingMethods::iterator SO = M->second.begin(), 17517 SOEnd = M->second.end(); 17518 SO != SOEnd; ++SO) { 17519 assert(SO->second.size() > 0 &&((void)0) 17520 "Virtual function without overriding functions?")((void)0); 17521 if (SO->second.size() == 1) 17522 continue; 17523 17524 // C++ [class.virtual]p2: 17525 // In a derived class, if a virtual member function of a base 17526 // class subobject has more than one final overrider the 17527 // program is ill-formed. 17528 Diag(Record->getLocation(), diag::err_multiple_final_overriders) 17529 << (const NamedDecl *)M->first << Record; 17530 Diag(M->first->getLocation(), 17531 diag::note_overridden_virtual_function); 17532 for (OverridingMethods::overriding_iterator 17533 OM = SO->second.begin(), 17534 OMEnd = SO->second.end(); 17535 OM != OMEnd; ++OM) 17536 Diag(OM->Method->getLocation(), diag::note_final_overrider) 17537 << (const NamedDecl *)M->first << OM->Method->getParent(); 17538 17539 Record->setInvalidDecl(); 17540 } 17541 } 17542 CXXRecord->completeDefinition(&FinalOverriders); 17543 Completed = true; 17544 } 17545 } 17546 } 17547 } 17548 17549 if (!Completed) 17550 Record->completeDefinition(); 17551 17552 // Handle attributes before checking the layout. 17553 ProcessDeclAttributeList(S, Record, Attrs); 17554 17555 // We may have deferred checking for a deleted destructor. Check now. 17556 if (CXXRecord) { 17557 auto *Dtor = CXXRecord->getDestructor(); 17558 if (Dtor && Dtor->isImplicit() && 17559 ShouldDeleteSpecialMember(Dtor, CXXDestructor)) { 17560 CXXRecord->setImplicitDestructorIsDeleted(); 17561 SetDeclDeleted(Dtor, CXXRecord->getLocation()); 17562 } 17563 } 17564 17565 if (Record->hasAttrs()) { 17566 CheckAlignasUnderalignment(Record); 17567 17568 if (const MSInheritanceAttr *IA = Record->getAttr<MSInheritanceAttr>()) 17569 checkMSInheritanceAttrOnDefinition(cast<CXXRecordDecl>(Record), 17570 IA->getRange(), IA->getBestCase(), 17571 IA->getInheritanceModel()); 17572 } 17573 17574 // Check if the structure/union declaration is a type that can have zero 17575 // size in C. For C this is a language extension, for C++ it may cause 17576 // compatibility problems. 17577 bool CheckForZeroSize; 17578 if (!getLangOpts().CPlusPlus) { 17579 CheckForZeroSize = true; 17580 } else { 17581 // For C++ filter out types that cannot be referenced in C code. 17582 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record); 17583 CheckForZeroSize = 17584 CXXRecord->getLexicalDeclContext()->isExternCContext() && 17585 !CXXRecord->isDependentType() && !inTemplateInstantiation() && 17586 CXXRecord->isCLike(); 17587 } 17588 if (CheckForZeroSize) { 17589 bool ZeroSize = true; 17590 bool IsEmpty = true; 17591 unsigned NonBitFields = 0; 17592 for (RecordDecl::field_iterator I = Record->field_begin(), 17593 E = Record->field_end(); 17594 (NonBitFields == 0 || ZeroSize) && I != E; ++I) { 17595 IsEmpty = false; 17596 if (I->isUnnamedBitfield()) { 17597 if (!I->isZeroLengthBitField(Context)) 17598 ZeroSize = false; 17599 } else { 17600 ++NonBitFields; 17601 QualType FieldType = I->getType(); 17602 if (FieldType->isIncompleteType() || 17603 !Context.getTypeSizeInChars(FieldType).isZero()) 17604 ZeroSize = false; 17605 } 17606 } 17607 17608 // Empty structs are an extension in C (C99 6.7.2.1p7). They are 17609 // allowed in C++, but warn if its declaration is inside 17610 // extern "C" block. 17611 if (ZeroSize) { 17612 Diag(RecLoc, getLangOpts().CPlusPlus ? 17613 diag::warn_zero_size_struct_union_in_extern_c : 17614 diag::warn_zero_size_struct_union_compat) 17615 << IsEmpty << Record->isUnion() << (NonBitFields > 1); 17616 } 17617 17618 // Structs without named members are extension in C (C99 6.7.2.1p7), 17619 // but are accepted by GCC. 17620 if (NonBitFields == 0 && !getLangOpts().CPlusPlus) { 17621 Diag(RecLoc, IsEmpty ? diag::ext_empty_struct_union : 17622 diag::ext_no_named_members_in_struct_union) 17623 << Record->isUnion(); 17624 } 17625 } 17626 } else { 17627 ObjCIvarDecl **ClsFields = 17628 reinterpret_cast<ObjCIvarDecl**>(RecFields.data()); 17629 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) { 17630 ID->setEndOfDefinitionLoc(RBrac); 17631 // Add ivar's to class's DeclContext. 17632 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 17633 ClsFields[i]->setLexicalDeclContext(ID); 17634 ID->addDecl(ClsFields[i]); 17635 } 17636 // Must enforce the rule that ivars in the base classes may not be 17637 // duplicates. 17638 if (ID->getSuperClass()) 17639 DiagnoseDuplicateIvars(ID, ID->getSuperClass()); 17640 } else if (ObjCImplementationDecl *IMPDecl = 17641 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) { 17642 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl")((void)0); 17643 for (unsigned I = 0, N = RecFields.size(); I != N; ++I) 17644 // Ivar declared in @implementation never belongs to the implementation. 17645 // Only it is in implementation's lexical context. 17646 ClsFields[I]->setLexicalDeclContext(IMPDecl); 17647 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac); 17648 IMPDecl->setIvarLBraceLoc(LBrac); 17649 IMPDecl->setIvarRBraceLoc(RBrac); 17650 } else if (ObjCCategoryDecl *CDecl = 17651 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) { 17652 // case of ivars in class extension; all other cases have been 17653 // reported as errors elsewhere. 17654 // FIXME. Class extension does not have a LocEnd field. 17655 // CDecl->setLocEnd(RBrac); 17656 // Add ivar's to class extension's DeclContext. 17657 // Diagnose redeclaration of private ivars. 17658 ObjCInterfaceDecl *IDecl = CDecl->getClassInterface(); 17659 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) { 17660 if (IDecl) { 17661 if (const ObjCIvarDecl *ClsIvar = 17662 IDecl->getIvarDecl(ClsFields[i]->getIdentifier())) { 17663 Diag(ClsFields[i]->getLocation(), 17664 diag::err_duplicate_ivar_declaration); 17665 Diag(ClsIvar->getLocation(), diag::note_previous_definition); 17666 continue; 17667 } 17668 for (const auto *Ext : IDecl->known_extensions()) { 17669 if (const ObjCIvarDecl *ClsExtIvar 17670 = Ext->getIvarDecl(ClsFields[i]->getIdentifier())) { 17671 Diag(ClsFields[i]->getLocation(), 17672 diag::err_duplicate_ivar_declaration); 17673 Diag(ClsExtIvar->getLocation(), diag::note_previous_definition); 17674 continue; 17675 } 17676 } 17677 } 17678 ClsFields[i]->setLexicalDeclContext(CDecl); 17679 CDecl->addDecl(ClsFields[i]); 17680 } 17681 CDecl->setIvarLBraceLoc(LBrac); 17682 CDecl->setIvarRBraceLoc(RBrac); 17683 } 17684 } 17685} 17686 17687/// Determine whether the given integral value is representable within 17688/// the given type T. 17689static bool isRepresentableIntegerValue(ASTContext &Context, 17690 llvm::APSInt &Value, 17691 QualType T) { 17692 assert((T->isIntegralType(Context) || T->isEnumeralType()) &&((void)0) 17693 "Integral type required!")((void)0); 17694 unsigned BitWidth = Context.getIntWidth(T); 17695 17696 if (Value.isUnsigned() || Value.isNonNegative()) { 17697 if (T->isSignedIntegerOrEnumerationType()) 17698 --BitWidth; 17699 return Value.getActiveBits() <= BitWidth; 17700 } 17701 return Value.getMinSignedBits() <= BitWidth; 17702} 17703 17704// Given an integral type, return the next larger integral type 17705// (or a NULL type of no such type exists). 17706static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) { 17707 // FIXME: Int128/UInt128 support, which also needs to be introduced into 17708 // enum checking below. 17709 assert((T->isIntegralType(Context) ||((void)0) 17710 T->isEnumeralType()) && "Integral type required!")((void)0); 17711 const unsigned NumTypes = 4; 17712 QualType SignedIntegralTypes[NumTypes] = { 17713 Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy 17714 }; 17715 QualType UnsignedIntegralTypes[NumTypes] = { 17716 Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy, 17717 Context.UnsignedLongLongTy 17718 }; 17719 17720 unsigned BitWidth = Context.getTypeSize(T); 17721 QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes 17722 : UnsignedIntegralTypes; 17723 for (unsigned I = 0; I != NumTypes; ++I) 17724 if (Context.getTypeSize(Types[I]) > BitWidth) 17725 return Types[I]; 17726 17727 return QualType(); 17728} 17729 17730EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum, 17731 EnumConstantDecl *LastEnumConst, 17732 SourceLocation IdLoc, 17733 IdentifierInfo *Id, 17734 Expr *Val) { 17735 unsigned IntWidth = Context.getTargetInfo().getIntWidth(); 17736 llvm::APSInt EnumVal(IntWidth); 17737 QualType EltTy; 17738 17739 if (Val && DiagnoseUnexpandedParameterPack(Val, UPPC_EnumeratorValue)) 17740 Val = nullptr; 17741 17742 if (Val) 17743 Val = DefaultLvalueConversion(Val).get(); 17744 17745 if (Val) { 17746 if (Enum->isDependentType() || Val->isTypeDependent()) 17747 EltTy = Context.DependentTy; 17748 else { 17749 // FIXME: We don't allow folding in C++11 mode for an enum with a fixed 17750 // underlying type, but do allow it in all other contexts. 17751 if (getLangOpts().CPlusPlus11 && Enum->isFixed()) { 17752 // C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the 17753 // constant-expression in the enumerator-definition shall be a converted 17754 // constant expression of the underlying type. 17755 EltTy = Enum->getIntegerType(); 17756 ExprResult Converted = 17757 CheckConvertedConstantExpression(Val, EltTy, EnumVal, 17758 CCEK_Enumerator); 17759 if (Converted.isInvalid()) 17760 Val = nullptr; 17761 else 17762 Val = Converted.get(); 17763 } else if (!Val->isValueDependent() && 17764 !(Val = 17765 VerifyIntegerConstantExpression(Val, &EnumVal, AllowFold) 17766 .get())) { 17767 // C99 6.7.2.2p2: Make sure we have an integer constant expression. 17768 } else { 17769 if (Enum->isComplete()) { 17770 EltTy = Enum->getIntegerType(); 17771 17772 // In Obj-C and Microsoft mode, require the enumeration value to be 17773 // representable in the underlying type of the enumeration. In C++11, 17774 // we perform a non-narrowing conversion as part of converted constant 17775 // expression checking. 17776 if (!isRepresentableIntegerValue(Context, EnumVal, EltTy)) { 17777 if (Context.getTargetInfo() 17778 .getTriple() 17779 .isWindowsMSVCEnvironment()) { 17780 Diag(IdLoc, diag::ext_enumerator_too_large) << EltTy; 17781 } else { 17782 Diag(IdLoc, diag::err_enumerator_too_large) << EltTy; 17783 } 17784 } 17785 17786 // Cast to the underlying type. 17787 Val = ImpCastExprToType(Val, EltTy, 17788 EltTy->isBooleanType() ? CK_IntegralToBoolean 17789 : CK_IntegralCast) 17790 .get(); 17791 } else if (getLangOpts().CPlusPlus) { 17792 // C++11 [dcl.enum]p5: 17793 // If the underlying type is not fixed, the type of each enumerator 17794 // is the type of its initializing value: 17795 // - If an initializer is specified for an enumerator, the 17796 // initializing value has the same type as the expression. 17797 EltTy = Val->getType(); 17798 } else { 17799 // C99 6.7.2.2p2: 17800 // The expression that defines the value of an enumeration constant 17801 // shall be an integer constant expression that has a value 17802 // representable as an int. 17803 17804 // Complain if the value is not representable in an int. 17805 if (!isRepresentableIntegerValue(Context, EnumVal, Context.IntTy)) 17806 Diag(IdLoc, diag::ext_enum_value_not_int) 17807 << toString(EnumVal, 10) << Val->getSourceRange() 17808 << (EnumVal.isUnsigned() || EnumVal.isNonNegative()); 17809 else if (!Context.hasSameType(Val->getType(), Context.IntTy)) { 17810 // Force the type of the expression to 'int'. 17811 Val = ImpCastExprToType(Val, Context.IntTy, CK_IntegralCast).get(); 17812 } 17813 EltTy = Val->getType(); 17814 } 17815 } 17816 } 17817 } 17818 17819 if (!Val) { 17820 if (Enum->isDependentType()) 17821 EltTy = Context.DependentTy; 17822 else if (!LastEnumConst) { 17823 // C++0x [dcl.enum]p5: 17824 // If the underlying type is not fixed, the type of each enumerator 17825 // is the type of its initializing value: 17826 // - If no initializer is specified for the first enumerator, the 17827 // initializing value has an unspecified integral type. 17828 // 17829 // GCC uses 'int' for its unspecified integral type, as does 17830 // C99 6.7.2.2p3. 17831 if (Enum->isFixed()) { 17832 EltTy = Enum->getIntegerType(); 17833 } 17834 else { 17835 EltTy = Context.IntTy; 17836 } 17837 } else { 17838 // Assign the last value + 1. 17839 EnumVal = LastEnumConst->getInitVal(); 17840 ++EnumVal; 17841 EltTy = LastEnumConst->getType(); 17842 17843 // Check for overflow on increment. 17844 if (EnumVal < LastEnumConst->getInitVal()) { 17845 // C++0x [dcl.enum]p5: 17846 // If the underlying type is not fixed, the type of each enumerator 17847 // is the type of its initializing value: 17848 // 17849 // - Otherwise the type of the initializing value is the same as 17850 // the type of the initializing value of the preceding enumerator 17851 // unless the incremented value is not representable in that type, 17852 // in which case the type is an unspecified integral type 17853 // sufficient to contain the incremented value. If no such type 17854 // exists, the program is ill-formed. 17855 QualType T = getNextLargerIntegralType(Context, EltTy); 17856 if (T.isNull() || Enum->isFixed()) { 17857 // There is no integral type larger enough to represent this 17858 // value. Complain, then allow the value to wrap around. 17859 EnumVal = LastEnumConst->getInitVal(); 17860 EnumVal = EnumVal.zext(EnumVal.getBitWidth() * 2); 17861 ++EnumVal; 17862 if (Enum->isFixed()) 17863 // When the underlying type is fixed, this is ill-formed. 17864 Diag(IdLoc, diag::err_enumerator_wrapped) 17865 << toString(EnumVal, 10) 17866 << EltTy; 17867 else 17868 Diag(IdLoc, diag::ext_enumerator_increment_too_large) 17869 << toString(EnumVal, 10); 17870 } else { 17871 EltTy = T; 17872 } 17873 17874 // Retrieve the last enumerator's value, extent that type to the 17875 // type that is supposed to be large enough to represent the incremented 17876 // value, then increment. 17877 EnumVal = LastEnumConst->getInitVal(); 17878 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType()); 17879 EnumVal = EnumVal.zextOrTrunc(Context.getIntWidth(EltTy)); 17880 ++EnumVal; 17881 17882 // If we're not in C++, diagnose the overflow of enumerator values, 17883 // which in C99 means that the enumerator value is not representable in 17884 // an int (C99 6.7.2.2p2). However, we support GCC's extension that 17885 // permits enumerator values that are representable in some larger 17886 // integral type. 17887 if (!getLangOpts().CPlusPlus && !T.isNull()) 17888 Diag(IdLoc, diag::warn_enum_value_overflow); 17889 } else if (!getLangOpts().CPlusPlus && 17890 !isRepresentableIntegerValue(Context, EnumVal, EltTy)) { 17891 // Enforce C99 6.7.2.2p2 even when we compute the next value. 17892 Diag(IdLoc, diag::ext_enum_value_not_int) 17893 << toString(EnumVal, 10) << 1; 17894 } 17895 } 17896 } 17897 17898 if (!EltTy->isDependentType()) { 17899 // Make the enumerator value match the signedness and size of the 17900 // enumerator's type. 17901 EnumVal = EnumVal.extOrTrunc(Context.getIntWidth(EltTy)); 17902 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType()); 17903 } 17904 17905 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy, 17906 Val, EnumVal); 17907} 17908 17909Sema::SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II, 17910 SourceLocation IILoc) { 17911 if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) || 17912 !getLangOpts().CPlusPlus) 17913 return SkipBodyInfo(); 17914 17915 // We have an anonymous enum definition. Look up the first enumerator to 17916 // determine if we should merge the definition with an existing one and 17917 // skip the body. 17918 NamedDecl *PrevDecl = LookupSingleName(S, II, IILoc, LookupOrdinaryName, 17919 forRedeclarationInCurContext()); 17920 auto *PrevECD = dyn_cast_or_null<EnumConstantDecl>(PrevDecl); 17921 if (!PrevECD) 17922 return SkipBodyInfo(); 17923 17924 EnumDecl *PrevED = cast<EnumDecl>(PrevECD->getDeclContext()); 17925 NamedDecl *Hidden; 17926 if (!PrevED->getDeclName() && !hasVisibleDefinition(PrevED, &Hidden)) { 17927 SkipBodyInfo Skip; 17928 Skip.Previous = Hidden; 17929 return Skip; 17930 } 17931 17932 return SkipBodyInfo(); 17933} 17934 17935Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst, 17936 SourceLocation IdLoc, IdentifierInfo *Id, 17937 const ParsedAttributesView &Attrs, 17938 SourceLocation EqualLoc, Expr *Val) { 17939 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl); 17940 EnumConstantDecl *LastEnumConst = 17941 cast_or_null<EnumConstantDecl>(lastEnumConst); 17942 17943 // The scope passed in may not be a decl scope. Zip up the scope tree until 17944 // we find one that is. 17945 S = getNonFieldDeclScope(S); 17946 17947 // Verify that there isn't already something declared with this name in this 17948 // scope. 17949 LookupResult R(*this, Id, IdLoc, LookupOrdinaryName, ForVisibleRedeclaration); 17950 LookupName(R, S); 17951 NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>(); 17952 17953 if (PrevDecl && PrevDecl->isTemplateParameter()) { 17954 // Maybe we will complain about the shadowed template parameter. 17955 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl); 17956 // Just pretend that we didn't see the previous declaration. 17957 PrevDecl = nullptr; 17958 } 17959 17960 // C++ [class.mem]p15: 17961 // If T is the name of a class, then each of the following shall have a name 17962 // different from T: 17963 // - every enumerator of every member of class T that is an unscoped 17964 // enumerated type 17965 if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped()) 17966 DiagnoseClassNameShadow(TheEnumDecl->getDeclContext(), 17967 DeclarationNameInfo(Id, IdLoc)); 17968 17969 EnumConstantDecl *New = 17970 CheckEnumConstant(TheEnumDecl, LastEnumConst, IdLoc, Id, Val); 17971 if (!New) 17972 return nullptr; 17973 17974 if (PrevDecl) { 17975 if (!TheEnumDecl->isScoped() && isa<ValueDecl>(PrevDecl)) { 17976 // Check for other kinds of shadowing not already handled. 17977 CheckShadow(New, PrevDecl, R); 17978 } 17979 17980 // When in C++, we may get a TagDecl with the same name; in this case the 17981 // enum constant will 'hide' the tag. 17982 assert((getLangOpts().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&((void)0) 17983 "Received TagDecl when not in C++!")((void)0); 17984 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) { 17985 if (isa<EnumConstantDecl>(PrevDecl)) 17986 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id; 17987 else 17988 Diag(IdLoc, diag::err_redefinition) << Id; 17989 notePreviousDefinition(PrevDecl, IdLoc); 17990 return nullptr; 17991 } 17992 } 17993 17994 // Process attributes. 17995 ProcessDeclAttributeList(S, New, Attrs); 17996 AddPragmaAttributes(S, New); 17997 17998 // Register this decl in the current scope stack. 17999 New->setAccess(TheEnumDecl->getAccess()); 18000 PushOnScopeChains(New, S); 18001 18002 ActOnDocumentableDecl(New); 18003 18004 return New; 18005} 18006 18007// Returns true when the enum initial expression does not trigger the 18008// duplicate enum warning. A few common cases are exempted as follows: 18009// Element2 = Element1 18010// Element2 = Element1 + 1 18011// Element2 = Element1 - 1 18012// Where Element2 and Element1 are from the same enum. 18013static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) { 18014 Expr *InitExpr = ECD->getInitExpr(); 18015 if (!InitExpr) 18016 return true; 18017 InitExpr = InitExpr->IgnoreImpCasts(); 18018 18019 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(InitExpr)) { 18020 if (!BO->isAdditiveOp()) 18021 return true; 18022 IntegerLiteral *IL = dyn_cast<IntegerLiteral>(BO->getRHS()); 18023 if (!IL) 18024 return true; 18025 if (IL->getValue() != 1) 18026 return true; 18027 18028 InitExpr = BO->getLHS(); 18029 } 18030 18031 // This checks if the elements are from the same enum. 18032 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(InitExpr); 18033 if (!DRE) 18034 return true; 18035 18036 EnumConstantDecl *EnumConstant = dyn_cast<EnumConstantDecl>(DRE->getDecl()); 18037 if (!EnumConstant) 18038 return true; 18039 18040 if (cast<EnumDecl>(TagDecl::castFromDeclContext(ECD->getDeclContext())) != 18041 Enum) 18042 return true; 18043 18044 return false; 18045} 18046 18047// Emits a warning when an element is implicitly set a value that 18048// a previous element has already been set to. 18049static void CheckForDuplicateEnumValues(Sema &S, ArrayRef<Decl *> Elements, 18050 EnumDecl *Enum, QualType EnumType) { 18051 // Avoid anonymous enums 18052 if (!Enum->getIdentifier()) 18053 return; 18054 18055 // Only check for small enums. 18056 if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64) 18057 return; 18058 18059 if (S.Diags.isIgnored(diag::warn_duplicate_enum_values, Enum->getLocation())) 18060 return; 18061 18062 typedef SmallVector<EnumConstantDecl *, 3> ECDVector; 18063 typedef SmallVector<std::unique_ptr<ECDVector>, 3> DuplicatesVector; 18064 18065 typedef llvm::PointerUnion<EnumConstantDecl*, ECDVector*> DeclOrVector; 18066 18067 // DenseMaps cannot contain the all ones int64_t value, so use unordered_map. 18068 typedef std::unordered_map<int64_t, DeclOrVector> ValueToVectorMap; 18069 18070 // Use int64_t as a key to avoid needing special handling for map keys. 18071 auto EnumConstantToKey = [](const EnumConstantDecl *D) { 18072 llvm::APSInt Val = D->getInitVal(); 18073 return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue(); 18074 }; 18075 18076 DuplicatesVector DupVector; 18077 ValueToVectorMap EnumMap; 18078 18079 // Populate the EnumMap with all values represented by enum constants without 18080 // an initializer. 18081 for (auto *Element : Elements) { 18082 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Element); 18083 18084 // Null EnumConstantDecl means a previous diagnostic has been emitted for 18085 // this constant. Skip this enum since it may be ill-formed. 18086 if (!ECD) { 18087 return; 18088 } 18089 18090 // Constants with initalizers are handled in the next loop. 18091 if (ECD->getInitExpr()) 18092 continue; 18093 18094 // Duplicate values are handled in the next loop. 18095 EnumMap.insert({EnumConstantToKey(ECD), ECD}); 18096 } 18097 18098 if (EnumMap.size() == 0) 18099 return; 18100 18101 // Create vectors for any values that has duplicates. 18102 for (auto *Element : Elements) { 18103 // The last loop returned if any constant was null. 18104 EnumConstantDecl *ECD = cast<EnumConstantDecl>(Element); 18105 if (!ValidDuplicateEnum(ECD, Enum)) 18106 continue; 18107 18108 auto Iter = EnumMap.find(EnumConstantToKey(ECD)); 18109 if (Iter == EnumMap.end()) 18110 continue; 18111 18112 DeclOrVector& Entry = Iter->second; 18113 if (EnumConstantDecl *D = Entry.dyn_cast<EnumConstantDecl*>()) { 18114 // Ensure constants are different. 18115 if (D == ECD) 18116 continue; 18117 18118 // Create new vector and push values onto it. 18119 auto Vec = std::make_unique<ECDVector>(); 18120 Vec->push_back(D); 18121 Vec->push_back(ECD); 18122 18123 // Update entry to point to the duplicates vector. 18124 Entry = Vec.get(); 18125 18126 // Store the vector somewhere we can consult later for quick emission of 18127 // diagnostics. 18128 DupVector.emplace_back(std::move(Vec)); 18129 continue; 18130 } 18131 18132 ECDVector *Vec = Entry.get<ECDVector*>(); 18133 // Make sure constants are not added more than once. 18134 if (*Vec->begin() == ECD) 18135 continue; 18136 18137 Vec->push_back(ECD); 18138 } 18139 18140 // Emit diagnostics. 18141 for (const auto &Vec : DupVector) { 18142 assert(Vec->size() > 1 && "ECDVector should have at least 2 elements.")((void)0); 18143 18144 // Emit warning for one enum constant. 18145 auto *FirstECD = Vec->front(); 18146 S.Diag(FirstECD->getLocation(), diag::warn_duplicate_enum_values) 18147 << FirstECD << toString(FirstECD->getInitVal(), 10) 18148 << FirstECD->getSourceRange(); 18149 18150 // Emit one note for each of the remaining enum constants with 18151 // the same value. 18152 for (auto *ECD : llvm::make_range(Vec->begin() + 1, Vec->end())) 18153 S.Diag(ECD->getLocation(), diag::note_duplicate_element) 18154 << ECD << toString(ECD->getInitVal(), 10) 18155 << ECD->getSourceRange(); 18156 } 18157} 18158 18159bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val, 18160 bool AllowMask) const { 18161 assert(ED->isClosedFlag() && "looking for value in non-flag or open enum")((void)0); 18162 assert(ED->isCompleteDefinition() && "expected enum definition")((void)0); 18163 18164 auto R = FlagBitsCache.insert(std::make_pair(ED, llvm::APInt())); 18165 llvm::APInt &FlagBits = R.first->second; 18166 18167 if (R.second) { 18168 for (auto *E : ED->enumerators()) { 18169 const auto &EVal = E->getInitVal(); 18170 // Only single-bit enumerators introduce new flag values. 18171 if (EVal.isPowerOf2()) 18172 FlagBits = FlagBits.zextOrSelf(EVal.getBitWidth()) | EVal; 18173 } 18174 } 18175 18176 // A value is in a flag enum if either its bits are a subset of the enum's 18177 // flag bits (the first condition) or we are allowing masks and the same is 18178 // true of its complement (the second condition). When masks are allowed, we 18179 // allow the common idiom of ~(enum1 | enum2) to be a valid enum value. 18180 // 18181 // While it's true that any value could be used as a mask, the assumption is 18182 // that a mask will have all of the insignificant bits set. Anything else is 18183 // likely a logic error. 18184 llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(Val.getBitWidth()); 18185 return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val)); 18186} 18187 18188void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange, 18189 Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S, 18190 const ParsedAttributesView &Attrs) { 18191 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX); 18192 QualType EnumType = Context.getTypeDeclType(Enum); 18193 18194 ProcessDeclAttributeList(S, Enum, Attrs); 18195 18196 if (Enum->isDependentType()) { 18197 for (unsigned i = 0, e = Elements.size(); i != e; ++i) { 18198 EnumConstantDecl *ECD = 18199 cast_or_null<EnumConstantDecl>(Elements[i]); 18200 if (!ECD) continue; 18201 18202 ECD->setType(EnumType); 18203 } 18204 18205 Enum->completeDefinition(Context.DependentTy, Context.DependentTy, 0, 0); 18206 return; 18207 } 18208 18209 // TODO: If the result value doesn't fit in an int, it must be a long or long 18210 // long value. ISO C does not support this, but GCC does as an extension, 18211 // emit a warning. 18212 unsigned IntWidth = Context.getTargetInfo().getIntWidth(); 18213 unsigned CharWidth = Context.getTargetInfo().getCharWidth(); 18214 unsigned ShortWidth = Context.getTargetInfo().getShortWidth(); 18215 18216 // Verify that all the values are okay, compute the size of the values, and 18217 // reverse the list. 18218 unsigned NumNegativeBits = 0; 18219 unsigned NumPositiveBits = 0; 18220 18221 // Keep track of whether all elements have type int. 18222 bool AllElementsInt = true; 18223 18224 for (unsigned i = 0, e = Elements.size(); i != e; ++i) { 18225 EnumConstantDecl *ECD = 18226 cast_or_null<EnumConstantDecl>(Elements[i]); 18227 if (!ECD) continue; // Already issued a diagnostic. 18228 18229 const llvm::APSInt &InitVal = ECD->getInitVal(); 18230 18231 // Keep track of the size of positive and negative values. 18232 if (InitVal.isUnsigned() || InitVal.isNonNegative()) 18233 NumPositiveBits = std::max(NumPositiveBits, 18234 (unsigned)InitVal.getActiveBits()); 18235 else 18236 NumNegativeBits = std::max(NumNegativeBits, 18237 (unsigned)InitVal.getMinSignedBits()); 18238 18239 // Keep track of whether every enum element has type int (very common). 18240 if (AllElementsInt) 18241 AllElementsInt = ECD->getType() == Context.IntTy; 18242 } 18243 18244 // Figure out the type that should be used for this enum. 18245 QualType BestType; 18246 unsigned BestWidth; 18247 18248 // C++0x N3000 [conv.prom]p3: 18249 // An rvalue of an unscoped enumeration type whose underlying 18250 // type is not fixed can be converted to an rvalue of the first 18251 // of the following types that can represent all the values of 18252 // the enumeration: int, unsigned int, long int, unsigned long 18253 // int, long long int, or unsigned long long int. 18254 // C99 6.4.4.3p2: 18255 // An identifier declared as an enumeration constant has type int. 18256 // The C99 rule is modified by a gcc extension 18257 QualType BestPromotionType; 18258 18259 bool Packed = Enum->hasAttr<PackedAttr>(); 18260 // -fshort-enums is the equivalent to specifying the packed attribute on all 18261 // enum definitions. 18262 if (LangOpts.ShortEnums) 18263 Packed = true; 18264 18265 // If the enum already has a type because it is fixed or dictated by the 18266 // target, promote that type instead of analyzing the enumerators. 18267 if (Enum->isComplete()) { 18268 BestType = Enum->getIntegerType(); 18269 if (BestType->isPromotableIntegerType()) 18270 BestPromotionType = Context.getPromotedIntegerType(BestType); 18271 else 18272 BestPromotionType = BestType; 18273 18274 BestWidth = Context.getIntWidth(BestType); 18275 } 18276 else if (NumNegativeBits) { 18277 // If there is a negative value, figure out the smallest integer type (of 18278 // int/long/longlong) that fits. 18279 // If it's packed, check also if it fits a char or a short. 18280 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) { 18281 BestType = Context.SignedCharTy; 18282 BestWidth = CharWidth; 18283 } else if (Packed && NumNegativeBits <= ShortWidth && 18284 NumPositiveBits < ShortWidth) { 18285 BestType = Context.ShortTy; 18286 BestWidth = ShortWidth; 18287 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) { 18288 BestType = Context.IntTy; 18289 BestWidth = IntWidth; 18290 } else { 18291 BestWidth = Context.getTargetInfo().getLongWidth(); 18292 18293 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) { 18294 BestType = Context.LongTy; 18295 } else { 18296 BestWidth = Context.getTargetInfo().getLongLongWidth(); 18297 18298 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth) 18299 Diag(Enum->getLocation(), diag::ext_enum_too_large); 18300 BestType = Context.LongLongTy; 18301 } 18302 } 18303 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType); 18304 } else { 18305 // If there is no negative value, figure out the smallest type that fits 18306 // all of the enumerator values. 18307 // If it's packed, check also if it fits a char or a short. 18308 if (Packed && NumPositiveBits <= CharWidth) { 18309 BestType = Context.UnsignedCharTy; 18310 BestPromotionType = Context.IntTy; 18311 BestWidth = CharWidth; 18312 } else if (Packed && NumPositiveBits <= ShortWidth) { 18313 BestType = Context.UnsignedShortTy; 18314 BestPromotionType = Context.IntTy; 18315 BestWidth = ShortWidth; 18316 } else if (NumPositiveBits <= IntWidth) { 18317 BestType = Context.UnsignedIntTy; 18318 BestWidth = IntWidth; 18319 BestPromotionType 18320 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) 18321 ? Context.UnsignedIntTy : Context.IntTy; 18322 } else if (NumPositiveBits <= 18323 (BestWidth = Context.getTargetInfo().getLongWidth())) { 18324 BestType = Context.UnsignedLongTy; 18325 BestPromotionType 18326 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) 18327 ? Context.UnsignedLongTy : Context.LongTy; 18328 } else { 18329 BestWidth = Context.getTargetInfo().getLongLongWidth(); 18330 assert(NumPositiveBits <= BestWidth &&((void)0) 18331 "How could an initializer get larger than ULL?")((void)0); 18332 BestType = Context.UnsignedLongLongTy; 18333 BestPromotionType 18334 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus) 18335 ? Context.UnsignedLongLongTy : Context.LongLongTy; 18336 } 18337 } 18338 18339 // Loop over all of the enumerator constants, changing their types to match 18340 // the type of the enum if needed. 18341 for (auto *D : Elements) { 18342 auto *ECD = cast_or_null<EnumConstantDecl>(D); 18343 if (!ECD) continue; // Already issued a diagnostic. 18344 18345 // Standard C says the enumerators have int type, but we allow, as an 18346 // extension, the enumerators to be larger than int size. If each 18347 // enumerator value fits in an int, type it as an int, otherwise type it the 18348 // same as the enumerator decl itself. This means that in "enum { X = 1U }" 18349 // that X has type 'int', not 'unsigned'. 18350 18351 // Determine whether the value fits into an int. 18352 llvm::APSInt InitVal = ECD->getInitVal(); 18353 18354 // If it fits into an integer type, force it. Otherwise force it to match 18355 // the enum decl type. 18356 QualType NewTy; 18357 unsigned NewWidth; 18358 bool NewSign; 18359 if (!getLangOpts().CPlusPlus && 18360 !Enum->isFixed() && 18361 isRepresentableIntegerValue(Context, InitVal, Context.IntTy)) { 18362 NewTy = Context.IntTy; 18363 NewWidth = IntWidth; 18364 NewSign = true; 18365 } else if (ECD->getType() == BestType) { 18366 // Already the right type! 18367 if (getLangOpts().CPlusPlus) 18368 // C++ [dcl.enum]p4: Following the closing brace of an 18369 // enum-specifier, each enumerator has the type of its 18370 // enumeration. 18371 ECD->setType(EnumType); 18372 continue; 18373 } else { 18374 NewTy = BestType; 18375 NewWidth = BestWidth; 18376 NewSign = BestType->isSignedIntegerOrEnumerationType(); 18377 } 18378 18379 // Adjust the APSInt value. 18380 InitVal = InitVal.extOrTrunc(NewWidth); 18381 InitVal.setIsSigned(NewSign); 18382 ECD->setInitVal(InitVal); 18383 18384 // Adjust the Expr initializer and type. 18385 if (ECD->getInitExpr() && 18386 !Context.hasSameType(NewTy, ECD->getInitExpr()->getType())) 18387 ECD->setInitExpr(ImplicitCastExpr::Create( 18388 Context, NewTy, CK_IntegralCast, ECD->getInitExpr(), 18389 /*base paths*/ nullptr, VK_PRValue, FPOptionsOverride())); 18390 if (getLangOpts().CPlusPlus) 18391 // C++ [dcl.enum]p4: Following the closing brace of an 18392 // enum-specifier, each enumerator has the type of its 18393 // enumeration. 18394 ECD->setType(EnumType); 18395 else 18396 ECD->setType(NewTy); 18397 } 18398 18399 Enum->completeDefinition(BestType, BestPromotionType, 18400 NumPositiveBits, NumNegativeBits); 18401 18402 CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType); 18403 18404 if (Enum->isClosedFlag()) { 18405 for (Decl *D : Elements) { 18406 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(D); 18407 if (!ECD) continue; // Already issued a diagnostic. 18408 18409 llvm::APSInt InitVal = ECD->getInitVal(); 18410 if (InitVal != 0 && !InitVal.isPowerOf2() && 18411 !IsValueInFlagEnum(Enum, InitVal, true)) 18412 Diag(ECD->getLocation(), diag::warn_flag_enum_constant_out_of_range) 18413 << ECD << Enum; 18414 } 18415 } 18416 18417 // Now that the enum type is defined, ensure it's not been underaligned. 18418 if (Enum->hasAttrs()) 18419 CheckAlignasUnderalignment(Enum); 18420} 18421 18422Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr, 18423 SourceLocation StartLoc, 18424 SourceLocation EndLoc) { 18425 StringLiteral *AsmString = cast<StringLiteral>(expr); 18426 18427 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext, 18428 AsmString, StartLoc, 18429 EndLoc); 18430 CurContext->addDecl(New); 18431 return New; 18432} 18433 18434void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name, 18435 IdentifierInfo* AliasName, 18436 SourceLocation PragmaLoc, 18437 SourceLocation NameLoc, 18438 SourceLocation AliasNameLoc) { 18439 NamedDecl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, 18440 LookupOrdinaryName); 18441 AttributeCommonInfo Info(AliasName, SourceRange(AliasNameLoc), 18442 AttributeCommonInfo::AS_Pragma); 18443 AsmLabelAttr *Attr = AsmLabelAttr::CreateImplicit( 18444 Context, AliasName->getName(), /*LiteralLabel=*/true, Info); 18445 18446 // If a declaration that: 18447 // 1) declares a function or a variable 18448 // 2) has external linkage 18449 // already exists, add a label attribute to it. 18450 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) { 18451 if (isDeclExternC(PrevDecl)) 18452 PrevDecl->addAttr(Attr); 18453 else 18454 Diag(PrevDecl->getLocation(), diag::warn_redefine_extname_not_applied) 18455 << /*Variable*/(isa<FunctionDecl>(PrevDecl) ? 0 : 1) << PrevDecl; 18456 // Otherwise, add a label atttibute to ExtnameUndeclaredIdentifiers. 18457 } else 18458 (void)ExtnameUndeclaredIdentifiers.insert(std::make_pair(Name, Attr)); 18459} 18460 18461void Sema::ActOnPragmaWeakID(IdentifierInfo* Name, 18462 SourceLocation PragmaLoc, 18463 SourceLocation NameLoc) { 18464 Decl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, LookupOrdinaryName); 18465 18466 if (PrevDecl) { 18467 PrevDecl->addAttr(WeakAttr::CreateImplicit(Context, PragmaLoc, AttributeCommonInfo::AS_Pragma)); 18468 } else { 18469 (void)WeakUndeclaredIdentifiers.insert( 18470 std::pair<IdentifierInfo*,WeakInfo> 18471 (Name, WeakInfo((IdentifierInfo*)nullptr, NameLoc))); 18472 } 18473} 18474 18475void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name, 18476 IdentifierInfo* AliasName, 18477 SourceLocation PragmaLoc, 18478 SourceLocation NameLoc, 18479 SourceLocation AliasNameLoc) { 18480 Decl *PrevDecl = LookupSingleName(TUScope, AliasName, AliasNameLoc, 18481 LookupOrdinaryName); 18482 WeakInfo W = WeakInfo(Name, NameLoc); 18483 18484 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) { 18485 if (!PrevDecl->hasAttr<AliasAttr>()) 18486 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl)) 18487 DeclApplyPragmaWeak(TUScope, ND, W); 18488 } else { 18489 (void)WeakUndeclaredIdentifiers.insert( 18490 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W)); 18491 } 18492} 18493 18494Decl *Sema::getObjCDeclContext() const { 18495 return (dyn_cast_or_null<ObjCContainerDecl>(CurContext)); 18496} 18497 18498Sema::FunctionEmissionStatus Sema::getEmissionStatus(FunctionDecl *FD, 18499 bool Final) { 18500 assert(FD && "Expected non-null FunctionDecl")((void)0); 18501 18502 // SYCL functions can be template, so we check if they have appropriate 18503 // attribute prior to checking if it is a template. 18504 if (LangOpts.SYCLIsDevice && FD->hasAttr<SYCLKernelAttr>()) 18505 return FunctionEmissionStatus::Emitted; 18506 18507 // Templates are emitted when they're instantiated. 18508 if (FD->isDependentContext()) 18509 return FunctionEmissionStatus::TemplateDiscarded; 18510 18511 // Check whether this function is an externally visible definition. 18512 auto IsEmittedForExternalSymbol = [this, FD]() { 18513 // We have to check the GVA linkage of the function's *definition* -- if we 18514 // only have a declaration, we don't know whether or not the function will 18515 // be emitted, because (say) the definition could include "inline". 18516 FunctionDecl *Def = FD->getDefinition(); 18517 18518 return Def && !isDiscardableGVALinkage( 18519 getASTContext().GetGVALinkageForFunction(Def)); 18520 }; 18521 18522 if (LangOpts.OpenMPIsDevice) { 18523 // In OpenMP device mode we will not emit host only functions, or functions 18524 // we don't need due to their linkage. 18525 Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy = 18526 OMPDeclareTargetDeclAttr::getDeviceType(FD->getCanonicalDecl()); 18527 // DevTy may be changed later by 18528 // #pragma omp declare target to(*) device_type(*). 18529 // Therefore DevTy having no value does not imply host. The emission status 18530 // will be checked again at the end of compilation unit with Final = true. 18531 if (DevTy.hasValue()) 18532 if (*DevTy == OMPDeclareTargetDeclAttr::DT_Host) 18533 return FunctionEmissionStatus::OMPDiscarded; 18534 // If we have an explicit value for the device type, or we are in a target 18535 // declare context, we need to emit all extern and used symbols. 18536 if (isInOpenMPDeclareTargetContext() || DevTy.hasValue()) 18537 if (IsEmittedForExternalSymbol()) 18538 return FunctionEmissionStatus::Emitted; 18539 // Device mode only emits what it must, if it wasn't tagged yet and needed, 18540 // we'll omit it. 18541 if (Final) 18542 return FunctionEmissionStatus::OMPDiscarded; 18543 } else if (LangOpts.OpenMP > 45) { 18544 // In OpenMP host compilation prior to 5.0 everything was an emitted host 18545 // function. In 5.0, no_host was introduced which might cause a function to 18546 // be ommitted. 18547 Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy = 18548 OMPDeclareTargetDeclAttr::getDeviceType(FD->getCanonicalDecl()); 18549 if (DevTy.hasValue()) 18550 if (*DevTy == OMPDeclareTargetDeclAttr::DT_NoHost) 18551 return FunctionEmissionStatus::OMPDiscarded; 18552 } 18553 18554 if (Final && LangOpts.OpenMP && !LangOpts.CUDA) 18555 return FunctionEmissionStatus::Emitted; 18556 18557 if (LangOpts.CUDA) { 18558 // When compiling for device, host functions are never emitted. Similarly, 18559 // when compiling for host, device and global functions are never emitted. 18560 // (Technically, we do emit a host-side stub for global functions, but this 18561 // doesn't count for our purposes here.) 18562 Sema::CUDAFunctionTarget T = IdentifyCUDATarget(FD); 18563 if (LangOpts.CUDAIsDevice && T == Sema::CFT_Host) 18564 return FunctionEmissionStatus::CUDADiscarded; 18565 if (!LangOpts.CUDAIsDevice && 18566 (T == Sema::CFT_Device || T == Sema::CFT_Global)) 18567 return FunctionEmissionStatus::CUDADiscarded; 18568 18569 if (IsEmittedForExternalSymbol()) 18570 return FunctionEmissionStatus::Emitted; 18571 } 18572 18573 // Otherwise, the function is known-emitted if it's in our set of 18574 // known-emitted functions. 18575 return FunctionEmissionStatus::Unknown; 18576} 18577 18578bool Sema::shouldIgnoreInHostDeviceCheck(FunctionDecl *Callee) { 18579 // Host-side references to a __global__ function refer to the stub, so the 18580 // function itself is never emitted and therefore should not be marked. 18581 // If we have host fn calls kernel fn calls host+device, the HD function 18582 // does not get instantiated on the host. We model this by omitting at the 18583 // call to the kernel from the callgraph. This ensures that, when compiling 18584 // for host, only HD functions actually called from the host get marked as 18585 // known-emitted. 18586 return LangOpts.CUDA && !LangOpts.CUDAIsDevice && 18587 IdentifyCUDATarget(Callee) == CFT_Global; 18588}

←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/AST/DeclBase.h

1//===- DeclBase.h - Base Classes for representing declarations --*- 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 Decl and DeclContext interfaces.
10//
11//===----------------------------------------------------------------------===//

13#ifndef LLVM_CLANG_AST_DECLBASE_H
14#define LLVM_CLANG_AST_DECLBASE_H

16#include "clang/AST/ASTDumperUtils.h"
17#include "clang/AST/AttrIterator.h"
18#include "clang/AST/DeclarationName.h"
19#include "clang/Basic/IdentifierTable.h"
20#include "clang/Basic/LLVM.h"
21#include "clang/Basic/SourceLocation.h"
22#include "clang/Basic/Specifiers.h"
23#include "llvm/ADT/ArrayRef.h"
24#include "llvm/ADT/PointerIntPair.h"
25#include "llvm/ADT/PointerUnion.h"
26#include "llvm/ADT/iterator.h"
27#include "llvm/ADT/iterator_range.h"
28#include "llvm/Support/Casting.h"
29#include "llvm/Support/Compiler.h"
30#include "llvm/Support/PrettyStackTrace.h"
31#include "llvm/Support/VersionTuple.h"
32#include <algorithm>
33#include <cassert>
34#include <cstddef>
35#include <iterator>
36#include <string>
37#include <type_traits>
38#include <utility>

40namespace clang {

42class ASTContext;
43class ASTMutationListener;
44class Attr;
45class BlockDecl;
46class DeclContext;
47class ExternalSourceSymbolAttr;
48class FunctionDecl;
49class FunctionType;
50class IdentifierInfo;
51enum Linkage : unsigned char;
52class LinkageSpecDecl;
53class Module;
54class NamedDecl;
55class ObjCCategoryDecl;
56class ObjCCategoryImplDecl;
57class ObjCContainerDecl;
58class ObjCImplDecl;
59class ObjCImplementationDecl;
60class ObjCInterfaceDecl;
61class ObjCMethodDecl;
62class ObjCProtocolDecl;
63struct PrintingPolicy;
64class RecordDecl;
65class SourceManager;
66class Stmt;
67class StoredDeclsMap;
68class TemplateDecl;
69class TemplateParameterList;
70class TranslationUnitDecl;
71class UsingDirectiveDecl;

73/// Captures the result of checking the availability of a
74/// declaration.
75enum AvailabilityResult {
AR_Available = 0,
AR_NotYetIntroduced,
AR_Deprecated,
AR_Unavailable
80};

82/// Decl - This represents one declaration (or definition), e.g. a variable,
83/// typedef, function, struct, etc.
84///
85/// Note: There are objects tacked on before the *beginning* of Decl
86/// (and its subclasses) in its Decl::operator new(). Proper alignment
87/// of all subclasses (not requiring more than the alignment of Decl) is
88/// asserted in DeclBase.cpp.
89class alignas(8) Decl {
90public:
/// Lists the kind of concrete classes of Decl.
enum Kind {
93#define DECL(DERIVED, BASE) DERIVED,
94#define ABSTRACT_DECL(DECL)
95#define DECL_RANGE(BASE, START, END) \
      first##BASE = START, last##BASE = END,
97#define LAST_DECL_RANGE(BASE, START, END) \
      first##BASE = START, last##BASE = END
99#include "clang/AST/DeclNodes.inc"
};

/// A placeholder type used to construct an empty shell of a
/// decl-derived type that will be filled in later (e.g., by some
/// deserialization method).
struct EmptyShell {};

/// IdentifierNamespace - The different namespaces in which
/// declarations may appear.  According to C99 6.2.3, there are
/// four namespaces, labels, tags, members and ordinary
/// identifiers.  C++ describes lookup completely differently:
/// certain lookups merely "ignore" certain kinds of declarations,
/// usually based on whether the declaration is of a type, etc.
///
/// These are meant as bitmasks, so that searches in
/// C++ can look into the "tag" namespace during ordinary lookup.
///
/// Decl currently provides 15 bits of IDNS bits.
enum IdentifierNamespace {
  /// Labels, declared with 'x:' and referenced with 'goto x'.
  IDNS_Label               = 0x0001,

  /// Tags, declared with 'struct foo;' and referenced with
  /// 'struct foo'.  All tags are also types.  This is what
  /// elaborated-type-specifiers look for in C.
  /// This also contains names that conflict with tags in the
  /// same scope but that are otherwise ordinary names (non-type
  /// template parameters and indirect field declarations).
  IDNS_Tag                 = 0x0002,

  /// Types, declared with 'struct foo', typedefs, etc.
  /// This is what elaborated-type-specifiers look for in C++,
  /// but note that it's ill-formed to find a non-tag.
  IDNS_Type                = 0x0004,

  /// Members, declared with object declarations within tag
  /// definitions.  In C, these can only be found by "qualified"
  /// lookup in member expressions.  In C++, they're found by
  /// normal lookup.
  IDNS_Member              = 0x0008,

  /// Namespaces, declared with 'namespace foo {}'.
  /// Lookup for nested-name-specifiers find these.
  IDNS_Namespace           = 0x0010,

  /// Ordinary names.  In C, everything that's not a label, tag,
  /// member, or function-local extern ends up here.
  IDNS_Ordinary            = 0x0020,

  /// Objective C \@protocol.
  IDNS_ObjCProtocol        = 0x0040,

  /// This declaration is a friend function.  A friend function
  /// declaration is always in this namespace but may also be in
  /// IDNS_Ordinary if it was previously declared.
  IDNS_OrdinaryFriend      = 0x0080,

  /// This declaration is a friend class.  A friend class
  /// declaration is always in this namespace but may also be in
  /// IDNS_Tag|IDNS_Type if it was previously declared.
  IDNS_TagFriend           = 0x0100,

  /// This declaration is a using declaration.  A using declaration
  /// *introduces* a number of other declarations into the current
  /// scope, and those declarations use the IDNS of their targets,
  /// but the actual using declarations go in this namespace.
  IDNS_Using               = 0x0200,

  /// This declaration is a C++ operator declared in a non-class
  /// context.  All such operators are also in IDNS_Ordinary.
  /// C++ lexical operator lookup looks for these.
  IDNS_NonMemberOperator   = 0x0400,

  /// This declaration is a function-local extern declaration of a
  /// variable or function. This may also be IDNS_Ordinary if it
  /// has been declared outside any function. These act mostly like
  /// invisible friend declarations, but are also visible to unqualified
  /// lookup within the scope of the declaring function.
  IDNS_LocalExtern         = 0x0800,

  /// This declaration is an OpenMP user defined reduction construction.
  IDNS_OMPReduction        = 0x1000,

  /// This declaration is an OpenMP user defined mapper.
  IDNS_OMPMapper           = 0x2000,
};

/// ObjCDeclQualifier - 'Qualifiers' written next to the return and
/// parameter types in method declarations.  Other than remembering
/// them and mangling them into the method's signature string, these
/// are ignored by the compiler; they are consumed by certain
/// remote-messaging frameworks.
///
/// in, inout, and out are mutually exclusive and apply only to
/// method parameters.  bycopy and byref are mutually exclusive and
/// apply only to method parameters (?).  oneway applies only to
/// results.  All of these expect their corresponding parameter to
/// have a particular type.  None of this is currently enforced by
/// clang.
///
/// This should be kept in sync with ObjCDeclSpec::ObjCDeclQualifier.
enum ObjCDeclQualifier {
  OBJC_TQ_None = 0x0,
  OBJC_TQ_In = 0x1,
  OBJC_TQ_Inout = 0x2,
  OBJC_TQ_Out = 0x4,
  OBJC_TQ_Bycopy = 0x8,
  OBJC_TQ_Byref = 0x10,
  OBJC_TQ_Oneway = 0x20,

  /// The nullability qualifier is set when the nullability of the
  /// result or parameter was expressed via a context-sensitive
  /// keyword.
  OBJC_TQ_CSNullability = 0x40
};

/// The kind of ownership a declaration has, for visibility purposes.
/// This enumeration is designed such that higher values represent higher
/// levels of name hiding.
enum class ModuleOwnershipKind : unsigned {
  /// This declaration is not owned by a module.
  Unowned,

  /// This declaration has an owning module, but is globally visible
  /// (typically because its owning module is visible and we know that
  /// modules cannot later become hidden in this compilation).
  /// After serialization and deserialization, this will be converted
  /// to VisibleWhenImported.
  Visible,

  /// This declaration has an owning module, and is visible when that
  /// module is imported.
  VisibleWhenImported,

  /// This declaration has an owning module, but is only visible to
  /// lookups that occur within that module.
  ModulePrivate
};

239protected:
/// The next declaration within the same lexical
/// DeclContext. These pointers form the linked list that is
/// traversed via DeclContext's decls_begin()/decls_end().
///
/// The extra two bits are used for the ModuleOwnershipKind.
llvm::PointerIntPair<Decl *, 2, ModuleOwnershipKind> NextInContextAndBits;

247private:
friend class DeclContext;

struct MultipleDC {
  DeclContext *SemanticDC;
  DeclContext *LexicalDC;
};

/// DeclCtx - Holds either a DeclContext* or a MultipleDC*.
/// For declarations that don't contain C++ scope specifiers, it contains
/// the DeclContext where the Decl was declared.
/// For declarations with C++ scope specifiers, it contains a MultipleDC*
/// with the context where it semantically belongs (SemanticDC) and the
/// context where it was lexically declared (LexicalDC).
/// e.g.:
///
///   namespace A {
///      void f(); // SemanticDC == LexicalDC == 'namespace A'
///   }
///   void A::f(); // SemanticDC == namespace 'A'
///                // LexicalDC == global namespace
llvm::PointerUnion<DeclContext*, MultipleDC*> DeclCtx;

bool isInSemaDC() const { return DeclCtx.is<DeclContext*>(); }
bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }

MultipleDC *getMultipleDC() const {
  return DeclCtx.get<MultipleDC*>();
}

DeclContext *getSemanticDC() const {
  return DeclCtx.get<DeclContext*>();
}

/// Loc - The location of this decl.
SourceLocation Loc;

/// DeclKind - This indicates which class this is.
unsigned DeclKind : 7;

/// InvalidDecl - This indicates a semantic error occurred.
unsigned InvalidDecl :  1;

/// HasAttrs - This indicates whether the decl has attributes or not.
unsigned HasAttrs : 1;

/// Implicit - Whether this declaration was implicitly generated by
/// the implementation rather than explicitly written by the user.
unsigned Implicit : 1;

/// Whether this declaration was "used", meaning that a definition is
/// required.
unsigned Used : 1;

/// Whether this declaration was "referenced".
/// The difference with 'Used' is whether the reference appears in a
/// evaluated context or not, e.g. functions used in uninstantiated templates
/// are regarded as "referenced" but not "used".
unsigned Referenced : 1;

/// Whether this declaration is a top-level declaration (function,
/// global variable, etc.) that is lexically inside an objc container
/// definition.
unsigned TopLevelDeclInObjCContainer : 1;

/// Whether statistic collection is enabled.
static bool StatisticsEnabled;

315protected:
friend class ASTDeclReader;
friend class ASTDeclWriter;
friend class ASTNodeImporter;
friend class ASTReader;
friend class CXXClassMemberWrapper;
friend class LinkageComputer;
template<typename decl_type> friend class Redeclarable;

/// Access - Used by C++ decls for the access specifier.
// NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
unsigned Access : 2;

/// Whether this declaration was loaded from an AST file.
unsigned FromASTFile : 1;

/// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
unsigned IdentifierNamespace : 14;

/// If 0, we have not computed the linkage of this declaration.
/// Otherwise, it is the linkage + 1.
mutable unsigned CacheValidAndLinkage : 3;

/// Allocate memory for a deserialized declaration.
///
/// This routine must be used to allocate memory for any declaration that is
/// deserialized from a module file.
///
/// \param Size The size of the allocated object.
/// \param Ctx The context in which we will allocate memory.
/// \param ID The global ID of the deserialized declaration.
/// \param Extra The amount of extra space to allocate after the object.
void *operator new(std::size_t Size, const ASTContext &Ctx, unsigned ID,
                   std::size_t Extra = 0);

/// Allocate memory for a non-deserialized declaration.
void *operator new(std::size_t Size, const ASTContext &Ctx,
                   DeclContext *Parent, std::size_t Extra = 0);

354private:
bool AccessDeclContextSanity() const;

/// Get the module ownership kind to use for a local lexical child of \p DC,
/// which may be either a local or (rarely) an imported declaration.
static ModuleOwnershipKind getModuleOwnershipKindForChildOf(DeclContext *DC) {
  if (DC) {
    auto *D = cast<Decl>(DC);
    auto MOK = D->getModuleOwnershipKind();
    if (MOK != ModuleOwnershipKind::Unowned &&
        (!D->isFromASTFile() || D->hasLocalOwningModuleStorage()))
      return MOK;
    // If D is not local and we have no local module storage, then we don't
    // need to track module ownership at all.
  }
  return ModuleOwnershipKind::Unowned;
}

372public:
Decl() = delete;
Decl(const Decl&) = delete;
Decl(Decl &&) = delete;
Decl &operator=(const Decl&) = delete;
Decl &operator=(Decl&&) = delete;

379protected:
Decl(Kind DK, DeclContext *DC, SourceLocation L)
    : NextInContextAndBits(nullptr, getModuleOwnershipKindForChildOf(DC)),
      DeclCtx(DC), Loc(L), DeclKind(DK), InvalidDecl(false), HasAttrs(false),
      Implicit(false), Used(false), Referenced(false),
      TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(0),
      IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
      CacheValidAndLinkage(0) {
  if (StatisticsEnabled) add(DK);
}

Decl(Kind DK, EmptyShell Empty)
    : DeclKind(DK), InvalidDecl(false), HasAttrs(false), Implicit(false),
      Used(false), Referenced(false), TopLevelDeclInObjCContainer(false),
      Access(AS_none), FromASTFile(0),
      IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
      CacheValidAndLinkage(0) {
  if (StatisticsEnabled) add(DK);
}

virtual ~Decl();

/// Update a potentially out-of-date declaration.
void updateOutOfDate(IdentifierInfo &II) const;

Linkage getCachedLinkage() const {
  return Linkage(CacheValidAndLinkage - 1);
}

void setCachedLinkage(Linkage L) const {
  CacheValidAndLinkage = L + 1;
}

bool hasCachedLinkage() const {
  return CacheValidAndLinkage;
}

416public:
/// Source range that this declaration covers.
virtual SourceRange getSourceRange() const LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(getLocation(), getLocation());
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getSourceRange().getBegin();
}

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getSourceRange().getEnd();
}

SourceLocation getLocation() const { return Loc; }
void setLocation(SourceLocation L) { Loc = L; }

Kind getKind() const { return static_cast<Kind>(DeclKind); }
const char *getDeclKindName() const;

Decl *getNextDeclInContext() { return NextInContextAndBits.getPointer(); }
const Decl *getNextDeclInContext() const {return NextInContextAndBits.getPointer();}

DeclContext *getDeclContext() {
  if (isInSemaDC())
    return getSemanticDC();
  return getMultipleDC()->SemanticDC;
}
const DeclContext *getDeclContext() const {
  return const_cast<Decl*>(this)->getDeclContext();
}

/// Find the innermost non-closure ancestor of this declaration,
/// walking up through blocks, lambdas, etc.  If that ancestor is
/// not a code context (!isFunctionOrMethod()), returns null.
///
/// A declaration may be its own non-closure context.
Decl *getNonClosureContext();
const Decl *getNonClosureContext() const {
  return const_cast<Decl*>(this)->getNonClosureContext();
}

TranslationUnitDecl *getTranslationUnitDecl();
const TranslationUnitDecl *getTranslationUnitDecl() const {
  return const_cast<Decl*>(this)->getTranslationUnitDecl();
}

bool isInAnonymousNamespace() const;

bool isInStdNamespace() const;

ASTContext &getASTContext() const LLVM_READONLY__attribute__((__pure__));

/// Helper to get the language options from the ASTContext.
/// Defined out of line to avoid depending on ASTContext.h.
const LangOptions &getLangOpts() const LLVM_READONLY__attribute__((__pure__));

void setAccess(AccessSpecifier AS) {
  Access = AS;
  assert(AccessDeclContextSanity())((void)0);
}

AccessSpecifier getAccess() const {
  assert(AccessDeclContextSanity())((void)0);
  return AccessSpecifier(Access);
}

/// Retrieve the access specifier for this declaration, even though
/// it may not yet have been properly set.
AccessSpecifier getAccessUnsafe() const {
  return AccessSpecifier(Access);
}

bool hasAttrs() const { return HasAttrs; }

void setAttrs(const AttrVec& Attrs) {
  return setAttrsImpl(Attrs, getASTContext());
}

AttrVec &getAttrs() {
  return const_cast<AttrVec&>(const_cast<const Decl*>(this)->getAttrs());
}

const AttrVec &getAttrs() const;
void dropAttrs();
void addAttr(Attr *A);

using attr_iterator = AttrVec::const_iterator;
using attr_range = llvm::iterator_range<attr_iterator>;

attr_range attrs() const {
  return attr_range(attr_begin(), attr_end());
}

attr_iterator attr_begin() const {
  return hasAttrs() ? getAttrs().begin() : nullptr;
}
attr_iterator attr_end() const {
  return hasAttrs() ? getAttrs().end() : nullptr;
}

template <typename T>
void dropAttr() {
  if (!HasAttrs) return;

  AttrVec &Vec = getAttrs();
  llvm::erase_if(Vec, [](Attr *A) { return isa<T>(A); });

  if (Vec.empty())
    HasAttrs = false;
}

template <typename T>
llvm::iterator_range<specific_attr_iterator<T>> specific_attrs() const {
  return llvm::make_range(specific_attr_begin<T>(), specific_attr_end<T>());
}

template <typename T>
specific_attr_iterator<T> specific_attr_begin() const {
  return specific_attr_iterator<T>(attr_begin());
}

template <typename T>
specific_attr_iterator<T> specific_attr_end() const {
  return specific_attr_iterator<T>(attr_end());
}

template<typename T> T *getAttr() const {
  return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : nullptr;
}

template<typename T> bool hasAttr() const {
  return hasAttrs() && hasSpecificAttr<T>(getAttrs());
}

/// getMaxAlignment - return the maximum alignment specified by attributes
/// on this decl, 0 if there are none.
unsigned getMaxAlignment() const;

/// setInvalidDecl - Indicates the Decl had a semantic error. This
/// allows for graceful error recovery.
void setInvalidDecl(bool Invalid = true);
bool isInvalidDecl() const { return (bool) InvalidDecl; }

/// isImplicit - Indicates whether the declaration was implicitly
/// generated by the implementation. If false, this declaration
/// was written explicitly in the source code.
bool isImplicit() const { return Implicit; }
void setImplicit(bool I = true) { Implicit = I; }

/// Whether *any* (re-)declaration of the entity was used, meaning that
/// a definition is required.
///
/// \param CheckUsedAttr When true, also consider the "used" attribute
/// (in addition to the "used" bit set by \c setUsed()) when determining
/// whether the function is used.
bool isUsed(bool CheckUsedAttr = true) const;

/// Set whether the declaration is used, in the sense of odr-use.
///
/// This should only be used immediately after creating a declaration.
/// It intentionally doesn't notify any listeners.
void setIsUsed() { getCanonicalDecl()->Used = true; }

/// Mark the declaration used, in the sense of odr-use.
///
/// This notifies any mutation listeners in addition to setting a bit
/// indicating the declaration is used.
void markUsed(ASTContext &C);

/// Whether any declaration of this entity was referenced.
bool isReferenced() const;

/// Whether this declaration was referenced. This should not be relied
/// upon for anything other than debugging.
bool isThisDeclarationReferenced() const { return Referenced; }

void setReferenced(bool R = true) { Referenced = R; }

/// Whether this declaration is a top-level declaration (function,
/// global variable, etc.) that is lexically inside an objc container
/// definition.
bool isTopLevelDeclInObjCContainer() const {
  return TopLevelDeclInObjCContainer;
}

void setTopLevelDeclInObjCContainer(bool V = true) {
  TopLevelDeclInObjCContainer = V;
}

/// Looks on this and related declarations for an applicable
/// external source symbol attribute.
ExternalSourceSymbolAttr *getExternalSourceSymbolAttr() const;

/// Whether this declaration was marked as being private to the
/// module in which it was defined.
bool isModulePrivate() const {
  return getModuleOwnershipKind() == ModuleOwnershipKind::ModulePrivate;
}

/// Return true if this declaration has an attribute which acts as
/// definition of the entity, such as 'alias' or 'ifunc'.
bool hasDefiningAttr() const;

/// Return this declaration's defining attribute if it has one.
const Attr *getDefiningAttr() const;

623protected:
/// Specify that this declaration was marked as being private
/// to the module in which it was defined.
void setModulePrivate() {
  // The module-private specifier has no effect on unowned declarations.
  // FIXME: We should track this in some way for source fidelity.
  if (getModuleOwnershipKind() == ModuleOwnershipKind::Unowned)
    return;
  setModuleOwnershipKind(ModuleOwnershipKind::ModulePrivate);
}

634public:
/// Set the FromASTFile flag. This indicates that this declaration
/// was deserialized and not parsed from source code and enables
/// features such as module ownership information.
void setFromASTFile() {
  FromASTFile = true;
}

/// Set the owning module ID.  This may only be called for
/// deserialized Decls.
void setOwningModuleID(unsigned ID) {
  assert(isFromASTFile() && "Only works on a deserialized declaration")((void)0);
  *((unsigned*)this - 2) = ID;
}

649public:
/// Determine the availability of the given declaration.
///
/// This routine will determine the most restrictive availability of
/// the given declaration (e.g., preferring 'unavailable' to
/// 'deprecated').
///
/// \param Message If non-NULL and the result is not \c
/// AR_Available, will be set to a (possibly empty) message
/// describing why the declaration has not been introduced, is
/// deprecated, or is unavailable.
///
/// \param EnclosingVersion The version to compare with. If empty, assume the
/// deployment target version.
///
/// \param RealizedPlatform If non-NULL and the availability result is found
/// in an available attribute it will set to the platform which is written in
/// the available attribute.
AvailabilityResult
getAvailability(std::string *Message = nullptr,
                VersionTuple EnclosingVersion = VersionTuple(),
                StringRef *RealizedPlatform = nullptr) const;

/// Retrieve the version of the target platform in which this
/// declaration was introduced.
///
/// \returns An empty version tuple if this declaration has no 'introduced'
/// availability attributes, or the version tuple that's specified in the
/// attribute otherwise.
VersionTuple getVersionIntroduced() const;

/// Determine whether this declaration is marked 'deprecated'.
///
/// \param Message If non-NULL and the declaration is deprecated,
/// this will be set to the message describing why the declaration
/// was deprecated (which may be empty).
bool isDeprecated(std::string *Message = nullptr) const {
  return getAvailability(Message) == AR_Deprecated;
}

/// Determine whether this declaration is marked 'unavailable'.
///
/// \param Message If non-NULL and the declaration is unavailable,
/// this will be set to the message describing why the declaration
/// was made unavailable (which may be empty).
bool isUnavailable(std::string *Message = nullptr) const {
  return getAvailability(Message) == AR_Unavailable;
}

/// Determine whether this is a weak-imported symbol.
///
/// Weak-imported symbols are typically marked with the
/// 'weak_import' attribute, but may also be marked with an
/// 'availability' attribute where we're targing a platform prior to
/// the introduction of this feature.
bool isWeakImported() const;

/// Determines whether this symbol can be weak-imported,
/// e.g., whether it would be well-formed to add the weak_import
/// attribute.
///
/// \param IsDefinition Set to \c true to indicate that this
/// declaration cannot be weak-imported because it has a definition.
bool canBeWeakImported(bool &IsDefinition) const;

/// Determine whether this declaration came from an AST file (such as
/// a precompiled header or module) rather than having been parsed.
bool isFromASTFile() const { return FromASTFile; }

/// Retrieve the global declaration ID associated with this
/// declaration, which specifies where this Decl was loaded from.
unsigned getGlobalID() const {
  if (isFromASTFile())
    return *((const unsigned*)this - 1);
  return 0;
}

/// Retrieve the global ID of the module that owns this particular
/// declaration.
unsigned getOwningModuleID() const {
  if (isFromASTFile())
    return *((const unsigned*)this - 2);
  return 0;
}

734private:
Module *getOwningModuleSlow() const;

737protected:
bool hasLocalOwningModuleStorage() const;

740public:
/// Get the imported owning module, if this decl is from an imported
/// (non-local) module.
Module *getImportedOwningModule() const {
  if (!isFromASTFile() || !hasOwningModule())
    return nullptr;

  return getOwningModuleSlow();
}

/// Get the local owning module, if known. Returns nullptr if owner is
/// not yet known or declaration is not from a module.
Module *getLocalOwningModule() const {
  if (isFromASTFile() || !hasOwningModule())
    return nullptr;

  assert(hasLocalOwningModuleStorage() &&((void)0)
         "owned local decl but no local module storage")((void)0);
  return reinterpret_cast<Module *const *>(this)[-1];
}
void setLocalOwningModule(Module *M) {
  assert(!isFromASTFile() && hasOwningModule() &&((void)0)
         hasLocalOwningModuleStorage() &&((void)0)
         "should not have a cached owning module")((void)0);
  reinterpret_cast<Module **>(this)[-1] = M;
}

/// Is this declaration owned by some module?
bool hasOwningModule() const {
  return getModuleOwnershipKind() != ModuleOwnershipKind::Unowned;
}

/// Get the module that owns this declaration (for visibility purposes).
Module *getOwningModule() const {
  return isFromASTFile() ? getImportedOwningModule() : getLocalOwningModule();
}

/// Get the module that owns this declaration for linkage purposes.
/// There only ever is such a module under the C++ Modules TS.
///
/// \param IgnoreLinkage Ignore the linkage of the entity; assume that
/// all declarations in a global module fragment are unowned.
Module *getOwningModuleForLinkage(bool IgnoreLinkage = false) const;

/// Determine whether this declaration is definitely visible to name lookup,
/// independent of whether the owning module is visible.
/// Note: The declaration may be visible even if this returns \c false if the
/// owning module is visible within the query context. This is a low-level
/// helper function; most code should be calling Sema::isVisible() instead.
bool isUnconditionallyVisible() const {
  return (int)getModuleOwnershipKind() <= (int)ModuleOwnershipKind::Visible;
}

/// Set that this declaration is globally visible, even if it came from a
/// module that is not visible.
void setVisibleDespiteOwningModule() {
  if (!isUnconditionallyVisible())
    setModuleOwnershipKind(ModuleOwnershipKind::Visible);
}

/// Get the kind of module ownership for this declaration.
ModuleOwnershipKind getModuleOwnershipKind() const {
  return NextInContextAndBits.getInt();
}

/// Set whether this declaration is hidden from name lookup.
void setModuleOwnershipKind(ModuleOwnershipKind MOK) {
  assert(!(getModuleOwnershipKind() == ModuleOwnershipKind::Unowned &&((void)0)
           MOK != ModuleOwnershipKind::Unowned && !isFromASTFile() &&((void)0)
           !hasLocalOwningModuleStorage()) &&((void)0)
         "no storage available for owning module for this declaration")((void)0);
  NextInContextAndBits.setInt(MOK);
}

unsigned getIdentifierNamespace() const {
  return IdentifierNamespace;
}

bool isInIdentifierNamespace(unsigned NS) const {
  return getIdentifierNamespace() & NS;
}

static unsigned getIdentifierNamespaceForKind(Kind DK);

bool hasTagIdentifierNamespace() const {
  return isTagIdentifierNamespace(getIdentifierNamespace());
}

static bool isTagIdentifierNamespace(unsigned NS) {
  // TagDecls have Tag and Type set and may also have TagFriend.
  return (NS & ~IDNS_TagFriend) == (IDNS_Tag | IDNS_Type);
}

/// getLexicalDeclContext - The declaration context where this Decl was
/// lexically declared (LexicalDC). May be different from
/// getDeclContext() (SemanticDC).
/// e.g.:
///
///   namespace A {
///      void f(); // SemanticDC == LexicalDC == 'namespace A'
///   }
///   void A::f(); // SemanticDC == namespace 'A'
///                // LexicalDC == global namespace
DeclContext *getLexicalDeclContext() {
  if (isInSemaDC())
    return getSemanticDC();
  return getMultipleDC()->LexicalDC;
}
const DeclContext *getLexicalDeclContext() const {
  return const_cast<Decl*>(this)->getLexicalDeclContext();
}

/// Determine whether this declaration is declared out of line (outside its
/// semantic context).
virtual bool isOutOfLine() const;

/// setDeclContext - Set both the semantic and lexical DeclContext
/// to DC.
void setDeclContext(DeclContext *DC);

void setLexicalDeclContext(DeclContext *DC);

/// Determine whether this declaration is a templated entity (whether it is
// within the scope of a template parameter).
bool isTemplated() const;

/// Determine the number of levels of template parameter surrounding this
/// declaration.
unsigned getTemplateDepth() const;

/// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
/// scoped decl is defined outside the current function or method.  This is
/// roughly global variables and functions, but also handles enums (which
/// could be defined inside or outside a function etc).
bool isDefinedOutsideFunctionOrMethod() const {
  return getParentFunctionOrMethod() == nullptr;
}

/// Determine whether a substitution into this declaration would occur as
/// part of a substitution into a dependent local scope. Such a substitution
/// transitively substitutes into all constructs nested within this
/// declaration.
///
/// This recognizes non-defining declarations as well as members of local
/// classes and lambdas:
/// \code
///     template<typename T> void foo() { void bar(); }
///     template<typename T> void foo2() { class ABC { void bar(); }; }
///     template<typename T> inline int x = [](){ return 0; }();
/// \endcode
bool isInLocalScopeForInstantiation() const;

/// If this decl is defined inside a function/method/block it returns
/// the corresponding DeclContext, otherwise it returns null.
const DeclContext *getParentFunctionOrMethod() const;
DeclContext *getParentFunctionOrMethod() {
  return const_cast<DeclContext*>(
                  const_cast<const Decl*>(this)->getParentFunctionOrMethod());
}

/// Retrieves the "canonical" declaration of the given declaration.
virtual Decl *getCanonicalDecl() { return this; }
const Decl *getCanonicalDecl() const {
  return const_cast<Decl*>(this)->getCanonicalDecl();
}

/// Whether this particular Decl is a canonical one.
bool isCanonicalDecl() const { return getCanonicalDecl() == this; }

909protected:
/// Returns the next redeclaration or itself if this is the only decl.
///
/// Decl subclasses that can be redeclared should override this method so that
/// Decl::redecl_iterator can iterate over them.
virtual Decl *getNextRedeclarationImpl() { return this; }

/// Implementation of getPreviousDecl(), to be overridden by any
/// subclass that has a redeclaration chain.
virtual Decl *getPreviousDeclImpl() { return nullptr; }

/// Implementation of getMostRecentDecl(), to be overridden by any
/// subclass that has a redeclaration chain.
virtual Decl *getMostRecentDeclImpl() { return this; }

924public:
/// Iterates through all the redeclarations of the same decl.
class redecl_iterator {
  /// Current - The current declaration.
  Decl *Current = nullptr;
  Decl *Starter;

public:
  using value_type = Decl *;
  using reference = const value_type &;
  using pointer = const value_type *;
  using iterator_category = std::forward_iterator_tag;
  using difference_type = std::ptrdiff_t;

  redecl_iterator() = default;
  explicit redecl_iterator(Decl *C) : Current(C), Starter(C) {}

  reference operator*() const { return Current; }
  value_type operator->() const { return Current; }

  redecl_iterator& operator++() {
    assert(Current && "Advancing while iterator has reached end")((void)0);
    // Get either previous decl or latest decl.
    Decl *Next = Current->getNextRedeclarationImpl();
    assert(Next && "Should return next redeclaration or itself, never null!")((void)0);
    Current = (Next != Starter) ? Next : nullptr;
    return *this;
  }

  redecl_iterator operator++(int) {
    redecl_iterator tmp(*this);
    ++(*this);
    return tmp;
  }

  friend bool operator==(redecl_iterator x, redecl_iterator y) {
    return x.Current == y.Current;
  }

  friend bool operator!=(redecl_iterator x, redecl_iterator y) {
    return x.Current != y.Current;
  }
};

using redecl_range = llvm::iterator_range<redecl_iterator>;

/// Returns an iterator range for all the redeclarations of the same
/// decl. It will iterate at least once (when this decl is the only one).
redecl_range redecls() const {
  return redecl_range(redecls_begin(), redecls_end());
}

redecl_iterator redecls_begin() const {
  return redecl_iterator(const_cast<Decl *>(this));
}

redecl_iterator redecls_end() const { return redecl_iterator(); }

/// Retrieve the previous declaration that declares the same entity
/// as this declaration, or NULL if there is no previous declaration.
Decl *getPreviousDecl() { return getPreviousDeclImpl(); }

/// Retrieve the previous declaration that declares the same entity
/// as this declaration, or NULL if there is no previous declaration.
const Decl *getPreviousDecl() const {
  return const_cast<Decl *>(this)->getPreviousDeclImpl();
}

/// True if this is the first declaration in its redeclaration chain.
bool isFirstDecl() const {
  return getPreviousDecl() == nullptr;
}

/// Retrieve the most recent declaration that declares the same entity
/// as this declaration (which may be this declaration).
Decl *getMostRecentDecl() { return getMostRecentDeclImpl(); }

/// Retrieve the most recent declaration that declares the same entity
/// as this declaration (which may be this declaration).
const Decl *getMostRecentDecl() const {
  return const_cast<Decl *>(this)->getMostRecentDeclImpl();
}

/// getBody - If this Decl represents a declaration for a body of code,
///  such as a function or method definition, this method returns the
///  top-level Stmt* of that body.  Otherwise this method returns null.
virtual Stmt* getBody() const { return nullptr; }

/// Returns true if this \c Decl represents a declaration for a body of
/// code, such as a function or method definition.
/// Note that \c hasBody can also return true if any redeclaration of this
/// \c Decl represents a declaration for a body of code.
virtual bool hasBody() const { return getBody() != nullptr; }

/// getBodyRBrace - Gets the right brace of the body, if a body exists.
/// This works whether the body is a CompoundStmt or a CXXTryStmt.
SourceLocation getBodyRBrace() const;

// global temp stats (until we have a per-module visitor)
static void add(Kind k);
static void EnableStatistics();
static void PrintStats();

/// isTemplateParameter - Determines whether this declaration is a
/// template parameter.
bool isTemplateParameter() const;

/// isTemplateParameter - Determines whether this declaration is a
/// template parameter pack.
bool isTemplateParameterPack() const;

/// Whether this declaration is a parameter pack.
bool isParameterPack() const;

/// returns true if this declaration is a template
bool isTemplateDecl() const;

/// Whether this declaration is a function or function template.
bool isFunctionOrFunctionTemplate() const {
  return (DeclKind >= Decl::firstFunction &&
          DeclKind <= Decl::lastFunction) ||
         DeclKind == FunctionTemplate;
}

/// If this is a declaration that describes some template, this
/// method returns that template declaration.
///
/// Note that this returns nullptr for partial specializations, because they
/// are not modeled as TemplateDecls. Use getDescribedTemplateParams to handle
/// those cases.
TemplateDecl *getDescribedTemplate() const;

/// If this is a declaration that describes some template or partial
/// specialization, this returns the corresponding template parameter list.
const TemplateParameterList *getDescribedTemplateParams() const;

/// Returns the function itself, or the templated function if this is a
/// function template.
FunctionDecl *getAsFunction() LLVM_READONLY__attribute__((__pure__));

const FunctionDecl *getAsFunction() const {
  return const_cast<Decl *>(this)->getAsFunction();
}

/// Changes the namespace of this declaration to reflect that it's
/// a function-local extern declaration.
///
/// These declarations appear in the lexical context of the extern
/// declaration, but in the semantic context of the enclosing namespace
/// scope.
void setLocalExternDecl() {
  Decl *Prev = getPreviousDecl();
  IdentifierNamespace &= ~IDNS_Ordinary;

  // It's OK for the declaration to still have the "invisible friend" flag or
  // the "conflicts with tag declarations in this scope" flag for the outer
  // scope.
  assert((IdentifierNamespace & ~(IDNS_OrdinaryFriend | IDNS_Tag)) == 0 &&((void)0)
         "namespace is not ordinary")((void)0);

  IdentifierNamespace |= IDNS_LocalExtern;
  if (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary)
    IdentifierNamespace |= IDNS_Ordinary;
}

/// Determine whether this is a block-scope declaration with linkage.
/// This will either be a local variable declaration declared 'extern', or a
/// local function declaration.
bool isLocalExternDecl() {
  return IdentifierNamespace & IDNS_LocalExtern;
}

/// Changes the namespace of this declaration to reflect that it's
/// the object of a friend declaration.
///
/// These declarations appear in the lexical context of the friending
/// class, but in the semantic context of the actual entity.  This property
/// applies only to a specific decl object;  other redeclarations of the
/// same entity may not (and probably don't) share this property.
void setObjectOfFriendDecl(bool PerformFriendInjection = false) {
  unsigned OldNS = IdentifierNamespace;
  assert((OldNS & (IDNS_Tag | IDNS_Ordinary |((void)0)
                   IDNS_TagFriend | IDNS_OrdinaryFriend |((void)0)
                   IDNS_LocalExtern | IDNS_NonMemberOperator)) &&((void)0)
         "namespace includes neither ordinary nor tag")((void)0);
  assert(!(OldNS & ~(IDNS_Tag | IDNS_Ordinary | IDNS_Type |((void)0)
                     IDNS_TagFriend | IDNS_OrdinaryFriend |((void)0)
                     IDNS_LocalExtern | IDNS_NonMemberOperator)) &&((void)0)
         "namespace includes other than ordinary or tag")((void)0);

  Decl *Prev = getPreviousDecl();
  IdentifierNamespace &= ~(IDNS_Ordinary | IDNS_Tag | IDNS_Type);

  if (OldNS & (IDNS_Tag | IDNS_TagFriend)) {
    IdentifierNamespace |= IDNS_TagFriend;
    if (PerformFriendInjection ||
        (Prev && Prev->getIdentifierNamespace() & IDNS_Tag))
      IdentifierNamespace |= IDNS_Tag | IDNS_Type;
  }

  if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend |
               IDNS_LocalExtern | IDNS_NonMemberOperator)) {
    IdentifierNamespace |= IDNS_OrdinaryFriend;
    if (PerformFriendInjection ||
        (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
      IdentifierNamespace |= IDNS_Ordinary;
  }
}

enum FriendObjectKind {
  FOK_None,      ///< Not a friend object.
  FOK_Declared,  ///< A friend of a previously-declared entity.
  FOK_Undeclared ///< A friend of a previously-undeclared entity.
};

/// Determines whether this declaration is the object of a
/// friend declaration and, if so, what kind.
///
/// There is currently no direct way to find the associated FriendDecl.
FriendObjectKind getFriendObjectKind() const {
  unsigned mask =
      (IdentifierNamespace & (IDNS_TagFriend | IDNS_OrdinaryFriend));
  if (!mask) return FOK_None;
  return (IdentifierNamespace & (IDNS_Tag | IDNS_Ordinary) ? FOK_Declared
                                                           : FOK_Undeclared);
}

/// Specifies that this declaration is a C++ overloaded non-member.
void setNonMemberOperator() {
  assert(getKind() == Function || getKind() == FunctionTemplate)((void)0);
  assert((IdentifierNamespace & IDNS_Ordinary) &&((void)0)
         "visible non-member operators should be in ordinary namespace")((void)0);
  IdentifierNamespace |= IDNS_NonMemberOperator;
}

static bool classofKind(Kind K) { return true; }
static DeclContext *castToDeclContext(const Decl *);
static Decl *castFromDeclContext(const DeclContext *);

void print(raw_ostream &Out, unsigned Indentation = 0,
           bool PrintInstantiation = false) const;
void print(raw_ostream &Out, const PrintingPolicy &Policy,
           unsigned Indentation = 0, bool PrintInstantiation = false) const;
static void printGroup(Decl** Begin, unsigned NumDecls,
                       raw_ostream &Out, const PrintingPolicy &Policy,
                       unsigned Indentation = 0);

// Debuggers don't usually respect default arguments.
void dump() const;

// Same as dump(), but forces color printing.
void dumpColor() const;

void dump(raw_ostream &Out, bool Deserialize = false,
          ASTDumpOutputFormat OutputFormat = ADOF_Default) const;

/// \return Unique reproducible object identifier
int64_t getID() const;

/// Looks through the Decl's underlying type to extract a FunctionType
/// when possible. Will return null if the type underlying the Decl does not
/// have a FunctionType.
const FunctionType *getFunctionType(bool BlocksToo = true) const;

1188private:
void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);
void setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
                         ASTContext &Ctx);

1193protected:
ASTMutationListener *getASTMutationListener() const;
1195};

1197/// Determine whether two declarations declare the same entity.
1198inline bool declaresSameEntity(const Decl *D1, const Decl *D2) {
if (!D1 || !D2)
  return false;

if (D1 == D2)
  return true;

return D1->getCanonicalDecl() == D2->getCanonicalDecl();
1206}

1208/// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
1209/// doing something to a specific decl.
1210class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
const Decl *TheDecl;
SourceLocation Loc;
SourceManager &SM;
const char *Message;

1216public:
PrettyStackTraceDecl(const Decl *theDecl, SourceLocation L,
                     SourceManager &sm, const char *Msg)
    : TheDecl(theDecl), Loc(L), SM(sm), Message(Msg) {}

void print(raw_ostream &OS) const override;
1222};
1223} // namespace clang

1225// Required to determine the layout of the PointerUnion<NamedDecl*> before
1226// seeing the NamedDecl definition being first used in DeclListNode::operator*.
1227namespace llvm {
template <> struct PointerLikeTypeTraits<::clang::NamedDecl *> {
  static inline void *getAsVoidPointer(::clang::NamedDecl *P) { return P; }
  static inline ::clang::NamedDecl *getFromVoidPointer(void *P) {
    return static_cast<::clang::NamedDecl *>(P);
  }
  static constexpr int NumLowBitsAvailable = 3;
};
1235}

1237namespace clang {
1238/// A list storing NamedDecls in the lookup tables.
1239class DeclListNode {
friend class ASTContext; // allocate, deallocate nodes.
friend class StoredDeclsList;
1242public:
using Decls = llvm::PointerUnion<NamedDecl*, DeclListNode*>;
class iterator {
  friend class DeclContextLookupResult;
  friend class StoredDeclsList;

  Decls Ptr;
  iterator(Decls Node) : Ptr(Node) { }
public:
  using difference_type = ptrdiff_t;
  using value_type = NamedDecl*;
  using pointer = void;
  using reference = value_type;
  using iterator_category = std::forward_iterator_tag;

  iterator() = default;

  reference operator*() const {
    assert(Ptr && "dereferencing end() iterator")((void)0);
    if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
      return CurNode->D;
    return Ptr.get<NamedDecl*>();
  }
  void operator->() const { } // Unsupported.
  bool operator==(const iterator &X) const { return Ptr == X.Ptr; }
  bool operator!=(const iterator &X) const { return Ptr != X.Ptr; }
  inline iterator &operator++() { // ++It
    assert(!Ptr.isNull() && "Advancing empty iterator")((void)0);

    if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
      Ptr = CurNode->Rest;
    else
      Ptr = nullptr;
    return *this;
  }
  iterator operator++(int) { // It++
    iterator temp = *this;
    ++(*this);
    return temp;
  }
  // Enables the pattern for (iterator I =..., E = I.end(); I != E; ++I)
  iterator end() { return iterator(); }
};
1285private:
NamedDecl *D = nullptr;
Decls Rest = nullptr;
DeclListNode(NamedDecl *ND) : D(ND) {}
1289};

1291/// The results of name lookup within a DeclContext.
1292class DeclContextLookupResult {
using Decls = DeclListNode::Decls;

/// When in collection form, this is what the Data pointer points to.
Decls Result;

1298public:
DeclContextLookupResult() = default;
DeclContextLookupResult(Decls Result) : Result(Result) {}

using iterator = DeclListNode::iterator;
using const_iterator = iterator;
using reference = iterator::reference;

iterator begin() { return iterator(Result); }
iterator end() { return iterator(); }
const_iterator begin() const {
  return const_cast<DeclContextLookupResult*>(this)->begin();
}
const_iterator end() const { return iterator(); }

bool empty() const { return Result.isNull();  }
bool isSingleResult() const { return Result.dyn_cast<NamedDecl*>(); }
reference front() const { return *begin(); }

// Find the first declaration of the given type in the list. Note that this
// is not in general the earliest-declared declaration, and should only be
// used when it's not possible for there to be more than one match or where
// it doesn't matter which one is found.
template<class T> T *find_first() const {
  for (auto *D : *this)
    if (T *Decl = dyn_cast<T>(D))
      return Decl;

  return nullptr;
}
1328};

1330/// DeclContext - This is used only as base class of specific decl types that
1331/// can act as declaration contexts. These decls are (only the top classes
1332/// that directly derive from DeclContext are mentioned, not their subclasses):
1333///
1334///   TranslationUnitDecl
1335///   ExternCContext
1336///   NamespaceDecl
1337///   TagDecl
1338///   OMPDeclareReductionDecl
1339///   OMPDeclareMapperDecl
1340///   FunctionDecl
1341///   ObjCMethodDecl
1342///   ObjCContainerDecl
1343///   LinkageSpecDecl
1344///   ExportDecl
1345///   BlockDecl
1346///   CapturedDecl
1347class DeclContext {
/// For makeDeclVisibleInContextImpl
friend class ASTDeclReader;
/// For reconcileExternalVisibleStorage, CreateStoredDeclsMap,
/// hasNeedToReconcileExternalVisibleStorage
friend class ExternalASTSource;
/// For CreateStoredDeclsMap
friend class DependentDiagnostic;
/// For hasNeedToReconcileExternalVisibleStorage,
/// hasLazyLocalLexicalLookups, hasLazyExternalLexicalLookups
friend class ASTWriter;

// We use uint64_t in the bit-fields below since some bit-fields
// cross the unsigned boundary and this breaks the packing.

/// Stores the bits used by DeclContext.
/// If modified NumDeclContextBit, the ctor of DeclContext and the accessor
/// methods in DeclContext should be updated appropriately.
class DeclContextBitfields {
  friend class DeclContext;
  /// DeclKind - This indicates which class this is.
  uint64_t DeclKind : 7;

  /// Whether this declaration context also has some external
  /// storage that contains additional declarations that are lexically
  /// part of this context.
  mutable uint64_t ExternalLexicalStorage : 1;

  /// Whether this declaration context also has some external
  /// storage that contains additional declarations that are visible
  /// in this context.
  mutable uint64_t ExternalVisibleStorage : 1;

  /// Whether this declaration context has had externally visible
  /// storage added since the last lookup. In this case, \c LookupPtr's
  /// invariant may not hold and needs to be fixed before we perform
  /// another lookup.
  mutable uint64_t NeedToReconcileExternalVisibleStorage : 1;

  /// If \c true, this context may have local lexical declarations
  /// that are missing from the lookup table.
  mutable uint64_t HasLazyLocalLexicalLookups : 1;

  /// If \c true, the external source may have lexical declarations
  /// that are missing from the lookup table.
  mutable uint64_t HasLazyExternalLexicalLookups : 1;

  /// If \c true, lookups should only return identifier from
  /// DeclContext scope (for example TranslationUnit). Used in
  /// LookupQualifiedName()
  mutable uint64_t UseQualifiedLookup : 1;
};

/// Number of bits in DeclContextBitfields.
enum { NumDeclContextBits = 13 };

/// Stores the bits used by TagDecl.
/// If modified NumTagDeclBits and the accessor
/// methods in TagDecl should be updated appropriately.
class TagDeclBitfields {
  friend class TagDecl;
  /// For the bits in DeclContextBitfields
  uint64_t : NumDeclContextBits;

  /// The TagKind enum.
  uint64_t TagDeclKind : 3;

  /// True if this is a definition ("struct foo {};"), false if it is a
  /// declaration ("struct foo;").  It is not considered a definition
  /// until the definition has been fully processed.
  uint64_t IsCompleteDefinition : 1;

  /// True if this is currently being defined.
  uint64_t IsBeingDefined : 1;

  /// True if this tag declaration is "embedded" (i.e., defined or declared
  /// for the very first time) in the syntax of a declarator.
  uint64_t IsEmbeddedInDeclarator : 1;

  /// True if this tag is free standing, e.g. "struct foo;".
  uint64_t IsFreeStanding : 1;

  /// Indicates whether it is possible for declarations of this kind
  /// to have an out-of-date definition.
  ///
  /// This option is only enabled when modules are enabled.
  uint64_t MayHaveOutOfDateDef : 1;

  /// Has the full definition of this type been required by a use somewhere in
  /// the TU.
  uint64_t IsCompleteDefinitionRequired : 1;
};

/// Number of non-inherited bits in TagDeclBitfields.
enum { NumTagDeclBits = 9 };

/// Stores the bits used by EnumDecl.
/// If modified NumEnumDeclBit and the accessor
/// methods in EnumDecl should be updated appropriately.
class EnumDeclBitfields {
  friend class EnumDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;
  /// For the bits in TagDeclBitfields.
  uint64_t : NumTagDeclBits;

  /// Width in bits required to store all the non-negative
  /// enumerators of this enum.
  uint64_t NumPositiveBits : 8;

  /// Width in bits required to store all the negative
  /// enumerators of this enum.
  uint64_t NumNegativeBits : 8;

  /// True if this tag declaration is a scoped enumeration. Only
  /// possible in C++11 mode.
  uint64_t IsScoped : 1;

  /// If this tag declaration is a scoped enum,
  /// then this is true if the scoped enum was declared using the class
  /// tag, false if it was declared with the struct tag. No meaning is
  /// associated if this tag declaration is not a scoped enum.
  uint64_t IsScopedUsingClassTag : 1;

  /// True if this is an enumeration with fixed underlying type. Only
  /// possible in C++11, Microsoft extensions, or Objective C mode.
  uint64_t IsFixed : 1;

  /// True if a valid hash is stored in ODRHash.
  uint64_t HasODRHash : 1;
};

/// Number of non-inherited bits in EnumDeclBitfields.
enum { NumEnumDeclBits = 20 };

/// Stores the bits used by RecordDecl.
/// If modified NumRecordDeclBits and the accessor
/// methods in RecordDecl should be updated appropriately.
class RecordDeclBitfields {
  friend class RecordDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;
  /// For the bits in TagDeclBitfields.
  uint64_t : NumTagDeclBits;

  /// This is true if this struct ends with a flexible
  /// array member (e.g. int X[]) or if this union contains a struct that does.
  /// If so, this cannot be contained in arrays or other structs as a member.
  uint64_t HasFlexibleArrayMember : 1;

  /// Whether this is the type of an anonymous struct or union.
  uint64_t AnonymousStructOrUnion : 1;

  /// This is true if this struct has at least one member
  /// containing an Objective-C object pointer type.
  uint64_t HasObjectMember : 1;

  /// This is true if struct has at least one member of
  /// 'volatile' type.
  uint64_t HasVolatileMember : 1;

  /// Whether the field declarations of this record have been loaded
  /// from external storage. To avoid unnecessary deserialization of
  /// methods/nested types we allow deserialization of just the fields
  /// when needed.
  mutable uint64_t LoadedFieldsFromExternalStorage : 1;

  /// Basic properties of non-trivial C structs.
  uint64_t NonTrivialToPrimitiveDefaultInitialize : 1;
  uint64_t NonTrivialToPrimitiveCopy : 1;
  uint64_t NonTrivialToPrimitiveDestroy : 1;

  /// The following bits indicate whether this is or contains a C union that
  /// is non-trivial to default-initialize, destruct, or copy. These bits
  /// imply the associated basic non-triviality predicates declared above.
  uint64_t HasNonTrivialToPrimitiveDefaultInitializeCUnion : 1;
  uint64_t HasNonTrivialToPrimitiveDestructCUnion : 1;
  uint64_t HasNonTrivialToPrimitiveCopyCUnion : 1;

  /// Indicates whether this struct is destroyed in the callee.
  uint64_t ParamDestroyedInCallee : 1;

  /// Represents the way this type is passed to a function.
  uint64_t ArgPassingRestrictions : 2;
};

/// Number of non-inherited bits in RecordDeclBitfields.
enum { NumRecordDeclBits = 14 };

/// Stores the bits used by OMPDeclareReductionDecl.
/// If modified NumOMPDeclareReductionDeclBits and the accessor
/// methods in OMPDeclareReductionDecl should be updated appropriately.
class OMPDeclareReductionDeclBitfields {
  friend class OMPDeclareReductionDecl;
  /// For the bits in DeclContextBitfields
  uint64_t : NumDeclContextBits;

  /// Kind of initializer,
  /// function call or omp_priv<init_expr> initializtion.
  uint64_t InitializerKind : 2;
};

/// Number of non-inherited bits in OMPDeclareReductionDeclBitfields.
enum { NumOMPDeclareReductionDeclBits = 2 };

/// Stores the bits used by FunctionDecl.
/// If modified NumFunctionDeclBits and the accessor
/// methods in FunctionDecl and CXXDeductionGuideDecl
/// (for IsCopyDeductionCandidate) should be updated appropriately.
class FunctionDeclBitfields {
  friend class FunctionDecl;
  /// For IsCopyDeductionCandidate
  friend class CXXDeductionGuideDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;

  uint64_t SClass : 3;
  uint64_t IsInline : 1;
  uint64_t IsInlineSpecified : 1;

  uint64_t IsVirtualAsWritten : 1;
  uint64_t IsPure : 1;
  uint64_t HasInheritedPrototype : 1;
  uint64_t HasWrittenPrototype : 1;
  uint64_t IsDeleted : 1;
  /// Used by CXXMethodDecl
  uint64_t IsTrivial : 1;

  /// This flag indicates whether this function is trivial for the purpose of
  /// calls. This is meaningful only when this function is a copy/move
  /// constructor or a destructor.
  uint64_t IsTrivialForCall : 1;

  uint64_t IsDefaulted : 1;
  uint64_t IsExplicitlyDefaulted : 1;
  uint64_t HasDefaultedFunctionInfo : 1;
  uint64_t HasImplicitReturnZero : 1;
  uint64_t IsLateTemplateParsed : 1;

  /// Kind of contexpr specifier as defined by ConstexprSpecKind.
  uint64_t ConstexprKind : 2;
  uint64_t InstantiationIsPending : 1;

  /// Indicates if the function uses __try.
  uint64_t UsesSEHTry : 1;

  /// Indicates if the function was a definition
  /// but its body was skipped.
  uint64_t HasSkippedBody : 1;

  /// Indicates if the function declaration will
  /// have a body, once we're done parsing it.
  uint64_t WillHaveBody : 1;

  /// Indicates that this function is a multiversioned
  /// function using attribute 'target'.
  uint64_t IsMultiVersion : 1;

  /// [C++17] Only used by CXXDeductionGuideDecl. Indicates that
  /// the Deduction Guide is the implicitly generated 'copy
  /// deduction candidate' (is used during overload resolution).
  uint64_t IsCopyDeductionCandidate : 1;

  /// Store the ODRHash after first calculation.
  uint64_t HasODRHash : 1;

  /// Indicates if the function uses Floating Point Constrained Intrinsics
  uint64_t UsesFPIntrin : 1;
};

/// Number of non-inherited bits in FunctionDeclBitfields.
enum { NumFunctionDeclBits = 27 };

/// Stores the bits used by CXXConstructorDecl. If modified
/// NumCXXConstructorDeclBits and the accessor
/// methods in CXXConstructorDecl should be updated appropriately.
class CXXConstructorDeclBitfields {
  friend class CXXConstructorDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;
  /// For the bits in FunctionDeclBitfields.
  uint64_t : NumFunctionDeclBits;

  /// 24 bits to fit in the remaining available space.
  /// Note that this makes CXXConstructorDeclBitfields take
  /// exactly 64 bits and thus the width of NumCtorInitializers
  /// will need to be shrunk if some bit is added to NumDeclContextBitfields,
  /// NumFunctionDeclBitfields or CXXConstructorDeclBitfields.
  uint64_t NumCtorInitializers : 21;
  uint64_t IsInheritingConstructor : 1;

  /// Whether this constructor has a trail-allocated explicit specifier.
  uint64_t HasTrailingExplicitSpecifier : 1;
  /// If this constructor does't have a trail-allocated explicit specifier.
  /// Whether this constructor is explicit specified.
  uint64_t IsSimpleExplicit : 1;
};

/// Number of non-inherited bits in CXXConstructorDeclBitfields.
enum {
  NumCXXConstructorDeclBits = 64 - NumDeclContextBits - NumFunctionDeclBits
};

/// Stores the bits used by ObjCMethodDecl.
/// If modified NumObjCMethodDeclBits and the accessor
/// methods in ObjCMethodDecl should be updated appropriately.
class ObjCMethodDeclBitfields {
  friend class ObjCMethodDecl;

  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;

  /// The conventional meaning of this method; an ObjCMethodFamily.
  /// This is not serialized; instead, it is computed on demand and
  /// cached.
  mutable uint64_t Family : ObjCMethodFamilyBitWidth;

  /// instance (true) or class (false) method.
  uint64_t IsInstance : 1;
  uint64_t IsVariadic : 1;

  /// True if this method is the getter or setter for an explicit property.
  uint64_t IsPropertyAccessor : 1;

  /// True if this method is a synthesized property accessor stub.
  uint64_t IsSynthesizedAccessorStub : 1;

  /// Method has a definition.
  uint64_t IsDefined : 1;

  /// Method redeclaration in the same interface.
  uint64_t IsRedeclaration : 1;

  /// Is redeclared in the same interface.
  mutable uint64_t HasRedeclaration : 1;

  /// \@required/\@optional
  uint64_t DeclImplementation : 2;

  /// in, inout, etc.
  uint64_t objcDeclQualifier : 7;

  /// Indicates whether this method has a related result type.
  uint64_t RelatedResultType : 1;

  /// Whether the locations of the selector identifiers are in a
  /// "standard" position, a enum SelectorLocationsKind.
  uint64_t SelLocsKind : 2;

  /// Whether this method overrides any other in the class hierarchy.
  ///
  /// A method is said to override any method in the class's
  /// base classes, its protocols, or its categories' protocols, that has
  /// the same selector and is of the same kind (class or instance).
  /// A method in an implementation is not considered as overriding the same
  /// method in the interface or its categories.
  uint64_t IsOverriding : 1;

  /// Indicates if the method was a definition but its body was skipped.
  uint64_t HasSkippedBody : 1;
};

/// Number of non-inherited bits in ObjCMethodDeclBitfields.
enum { NumObjCMethodDeclBits = 24 };

/// Stores the bits used by ObjCContainerDecl.
/// If modified NumObjCContainerDeclBits and the accessor
/// methods in ObjCContainerDecl should be updated appropriately.
class ObjCContainerDeclBitfields {
  friend class ObjCContainerDecl;
  /// For the bits in DeclContextBitfields
  uint32_t : NumDeclContextBits;

  // Not a bitfield but this saves space.
  // Note that ObjCContainerDeclBitfields is full.
  SourceLocation AtStart;
};

/// Number of non-inherited bits in ObjCContainerDeclBitfields.
/// Note that here we rely on the fact that SourceLocation is 32 bits
/// wide. We check this with the static_assert in the ctor of DeclContext.
enum { NumObjCContainerDeclBits = 64 - NumDeclContextBits };

/// Stores the bits used by LinkageSpecDecl.
/// If modified NumLinkageSpecDeclBits and the accessor
/// methods in LinkageSpecDecl should be updated appropriately.
class LinkageSpecDeclBitfields {
  friend class LinkageSpecDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;

  /// The language for this linkage specification with values
  /// in the enum LinkageSpecDecl::LanguageIDs.
  uint64_t Language : 3;

  /// True if this linkage spec has braces.
  /// This is needed so that hasBraces() returns the correct result while the
  /// linkage spec body is being parsed.  Once RBraceLoc has been set this is
  /// not used, so it doesn't need to be serialized.
  uint64_t HasBraces : 1;
};

/// Number of non-inherited bits in LinkageSpecDeclBitfields.
enum { NumLinkageSpecDeclBits = 4 };

/// Stores the bits used by BlockDecl.
/// If modified NumBlockDeclBits and the accessor
/// methods in BlockDecl should be updated appropriately.
class BlockDeclBitfields {
  friend class BlockDecl;
  /// For the bits in DeclContextBitfields.
  uint64_t : NumDeclContextBits;

  uint64_t IsVariadic : 1;
  uint64_t CapturesCXXThis : 1;
  uint64_t BlockMissingReturnType : 1;
  uint64_t IsConversionFromLambda : 1;

  /// A bit that indicates this block is passed directly to a function as a
  /// non-escaping parameter.
  uint64_t DoesNotEscape : 1;

  /// A bit that indicates whether it's possible to avoid coying this block to
  /// the heap when it initializes or is assigned to a local variable with
  /// automatic storage.
  uint64_t CanAvoidCopyToHeap : 1;
};

/// Number of non-inherited bits in BlockDeclBitfields.
enum { NumBlockDeclBits = 5 };

/// Pointer to the data structure used to lookup declarations
/// within this context (or a DependentStoredDeclsMap if this is a
/// dependent context). We maintain the invariant that, if the map
/// contains an entry for a DeclarationName (and we haven't lazily
/// omitted anything), then it contains all relevant entries for that
/// name (modulo the hasExternalDecls() flag).
mutable StoredDeclsMap *LookupPtr = nullptr;

1786protected:
/// This anonymous union stores the bits belonging to DeclContext and classes
/// deriving from it. The goal is to use otherwise wasted
/// space in DeclContext to store data belonging to derived classes.
/// The space saved is especially significient when pointers are aligned
/// to 8 bytes. In this case due to alignment requirements we have a
/// little less than 8 bytes free in DeclContext which we can use.
/// We check that none of the classes in this union is larger than
/// 8 bytes with static_asserts in the ctor of DeclContext.
union {
  DeclContextBitfields DeclContextBits;
  TagDeclBitfields TagDeclBits;
  EnumDeclBitfields EnumDeclBits;
  RecordDeclBitfields RecordDeclBits;
  OMPDeclareReductionDeclBitfields OMPDeclareReductionDeclBits;
  FunctionDeclBitfields FunctionDeclBits;
  CXXConstructorDeclBitfields CXXConstructorDeclBits;
  ObjCMethodDeclBitfields ObjCMethodDeclBits;
  ObjCContainerDeclBitfields ObjCContainerDeclBits;
  LinkageSpecDeclBitfields LinkageSpecDeclBits;
  BlockDeclBitfields BlockDeclBits;

  static_assert(sizeof(DeclContextBitfields) <= 8,
                "DeclContextBitfields is larger than 8 bytes!");
  static_assert(sizeof(TagDeclBitfields) <= 8,
                "TagDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(EnumDeclBitfields) <= 8,
                "EnumDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(RecordDeclBitfields) <= 8,
                "RecordDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(OMPDeclareReductionDeclBitfields) <= 8,
                "OMPDeclareReductionDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(FunctionDeclBitfields) <= 8,
                "FunctionDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(CXXConstructorDeclBitfields) <= 8,
                "CXXConstructorDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(ObjCMethodDeclBitfields) <= 8,
                "ObjCMethodDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(ObjCContainerDeclBitfields) <= 8,
                "ObjCContainerDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(LinkageSpecDeclBitfields) <= 8,
                "LinkageSpecDeclBitfields is larger than 8 bytes!");
  static_assert(sizeof(BlockDeclBitfields) <= 8,
                "BlockDeclBitfields is larger than 8 bytes!");
};

/// FirstDecl - The first declaration stored within this declaration
/// context.
mutable Decl *FirstDecl = nullptr;

/// LastDecl - The last declaration stored within this declaration
/// context. FIXME: We could probably cache this value somewhere
/// outside of the DeclContext, to reduce the size of DeclContext by
/// another pointer.
mutable Decl *LastDecl = nullptr;

/// Build up a chain of declarations.
///
/// \returns the first/last pair of declarations.
static std::pair<Decl *, Decl *>
BuildDeclChain(ArrayRef<Decl*> Decls, bool FieldsAlreadyLoaded);

DeclContext(Decl::Kind K);

1850public:
~DeclContext();

Decl::Kind getDeclKind() const {
  return static_cast<Decl::Kind>(DeclContextBits.DeclKind);
}

const char *getDeclKindName() const;

/// getParent - Returns the containing DeclContext.
DeclContext *getParent() {
  return cast<Decl>(this)->getDeclContext();
}
const DeclContext *getParent() const {
  return const_cast<DeclContext*>(this)->getParent();
}

/// getLexicalParent - Returns the containing lexical DeclContext. May be
/// different from getParent, e.g.:
///
///   namespace A {
///      struct S;
///   }
///   struct A::S {}; // getParent() == namespace 'A'
///                   // getLexicalParent() == translation unit
///
DeclContext *getLexicalParent() {
  return cast<Decl>(this)->getLexicalDeclContext();
}
const DeclContext *getLexicalParent() const {
  return const_cast<DeclContext*>(this)->getLexicalParent();
}

DeclContext *getLookupParent();

const DeclContext *getLookupParent() const {
  return const_cast<DeclContext*>(this)->getLookupParent();
}

ASTContext &getParentASTContext() const {
  return cast<Decl>(this)->getASTContext();
}

bool isClosure() const { return getDeclKind() == Decl::Block; }

/// Return this DeclContext if it is a BlockDecl. Otherwise, return the
/// innermost enclosing BlockDecl or null if there are no enclosing blocks.
const BlockDecl *getInnermostBlockDecl() const;

bool isObjCContainer() const {
  switch (getDeclKind()) {
  case Decl::ObjCCategory:
  case Decl::ObjCCategoryImpl:
  case Decl::ObjCImplementation:
  case Decl::ObjCInterface:
  case Decl::ObjCProtocol:
    return true;
  default:
    return false;
  }
}

bool isFunctionOrMethod() const {
  switch (getDeclKind()) {
  case Decl::Block:
  case Decl::Captured:
  case Decl::ObjCMethod:
    return true;
  default:
    return getDeclKind() >= Decl::firstFunction &&
           getDeclKind() <= Decl::lastFunction;
  }
}

/// Test whether the context supports looking up names.
bool isLookupContext() const {
  return !isFunctionOrMethod() && getDeclKind() != Decl::LinkageSpec &&
         getDeclKind() != Decl::Export;
}

bool isFileContext() const {
  return getDeclKind() == Decl::TranslationUnit ||
         getDeclKind() == Decl::Namespace;
}

bool isTranslationUnit() const {
  return getDeclKind() == Decl::TranslationUnit;
}

bool isRecord() const {
  return getDeclKind() >= Decl::firstRecord &&
34
←
Returning zero, which participates in a condition later→
39
←
Assuming the condition is false→
40
←
Returning zero, which participates in a condition later→
         getDeclKind() <= Decl::lastRecord;
}

bool isNamespace() const { return getDeclKind() == Decl::Namespace; }

bool isStdNamespace() const;

bool isInlineNamespace() const;

/// Determines whether this context is dependent on a
/// template parameter.
bool isDependentContext() const;

/// isTransparentContext - Determines whether this context is a
/// "transparent" context, meaning that the members declared in this
/// context are semantically declared in the nearest enclosing
/// non-transparent (opaque) context but are lexically declared in
/// this context. For example, consider the enumerators of an
/// enumeration type:
/// @code
/// enum E {
///   Val1
/// };
/// @endcode
/// Here, E is a transparent context, so its enumerator (Val1) will
/// appear (semantically) that it is in the same context of E.
/// Examples of transparent contexts include: enumerations (except for
/// C++0x scoped enums), and C++ linkage specifications.
bool isTransparentContext() const;

/// Determines whether this context or some of its ancestors is a
/// linkage specification context that specifies C linkage.
bool isExternCContext() const;

/// Retrieve the nearest enclosing C linkage specification context.
const LinkageSpecDecl *getExternCContext() const;

/// Determines whether this context or some of its ancestors is a
/// linkage specification context that specifies C++ linkage.
bool isExternCXXContext() const;

/// Determine whether this declaration context is equivalent
/// to the declaration context DC.
bool Equals(const DeclContext *DC) const {
  return DC && this->getPrimaryContext() == DC->getPrimaryContext();
}

/// Determine whether this declaration context encloses the
/// declaration context DC.
bool Encloses(const DeclContext *DC) const;

/// Find the nearest non-closure ancestor of this context,
/// i.e. the innermost semantic parent of this context which is not
/// a closure.  A context may be its own non-closure ancestor.
Decl *getNonClosureAncestor();
const Decl *getNonClosureAncestor() const {
  return const_cast<DeclContext*>(this)->getNonClosureAncestor();
}

/// getPrimaryContext - There may be many different
/// declarations of the same entity (including forward declarations
/// of classes, multiple definitions of namespaces, etc.), each with
/// a different set of declarations. This routine returns the
/// "primary" DeclContext structure, which will contain the
/// information needed to perform name lookup into this context.
DeclContext *getPrimaryContext();
const DeclContext *getPrimaryContext() const {
  return const_cast<DeclContext*>(this)->getPrimaryContext();
}

/// getRedeclContext - Retrieve the context in which an entity conflicts with
/// other entities of the same name, or where it is a redeclaration if the
/// two entities are compatible. This skips through transparent contexts.
DeclContext *getRedeclContext();
const DeclContext *getRedeclContext() const {
  return const_cast<DeclContext *>(this)->getRedeclContext();
}

/// Retrieve the nearest enclosing namespace context.
DeclContext *getEnclosingNamespaceContext();
const DeclContext *getEnclosingNamespaceContext() const {
  return const_cast<DeclContext *>(this)->getEnclosingNamespaceContext();
}

/// Retrieve the outermost lexically enclosing record context.
RecordDecl *getOuterLexicalRecordContext();
const RecordDecl *getOuterLexicalRecordContext() const {
  return const_cast<DeclContext *>(this)->getOuterLexicalRecordContext();
}

/// Test if this context is part of the enclosing namespace set of
/// the context NS, as defined in C++0x [namespace.def]p9. If either context
/// isn't a namespace, this is equivalent to Equals().
///
/// The enclosing namespace set of a namespace is the namespace and, if it is
/// inline, its enclosing namespace, recursively.
bool InEnclosingNamespaceSetOf(const DeclContext *NS) const;

/// Collects all of the declaration contexts that are semantically
/// connected to this declaration context.
///
/// For declaration contexts that have multiple semantically connected but
/// syntactically distinct contexts, such as C++ namespaces, this routine
/// retrieves the complete set of such declaration contexts in source order.
/// For example, given:
///
/// \code
/// namespace N {
///   int x;
/// }
/// namespace N {
///   int y;
/// }
/// \endcode
///
/// The \c Contexts parameter will contain both definitions of N.
///
/// \param Contexts Will be cleared and set to the set of declaration
/// contexts that are semanticaly connected to this declaration context,
/// in source order, including this context (which may be the only result,
/// for non-namespace contexts).
void collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts);

/// decl_iterator - Iterates through the declarations stored
/// within this context.
class decl_iterator {
  /// Current - The current declaration.
  Decl *Current = nullptr;

public:
  using value_type = Decl *;
  using reference = const value_type &;
  using pointer = const value_type *;
  using iterator_category = std::forward_iterator_tag;
  using difference_type = std::ptrdiff_t;

  decl_iterator() = default;
  explicit decl_iterator(Decl *C) : Current(C) {}

  reference operator*() const { return Current; }

  // This doesn't meet the iterator requirements, but it's convenient
  value_type operator->() const { return Current; }

  decl_iterator& operator++() {
    Current = Current->getNextDeclInContext();
    return *this;
  }

  decl_iterator operator++(int) {
    decl_iterator tmp(*this);
    ++(*this);
    return tmp;
  }

  friend bool operator==(decl_iterator x, decl_iterator y) {
    return x.Current == y.Current;
  }

  friend bool operator!=(decl_iterator x, decl_iterator y) {
    return x.Current != y.Current;
  }
};

using decl_range = llvm::iterator_range<decl_iterator>;

/// decls_begin/decls_end - Iterate over the declarations stored in
/// this context.
decl_range decls() const { return decl_range(decls_begin(), decls_end()); }
decl_iterator decls_begin() const;
decl_iterator decls_end() const { return decl_iterator(); }
bool decls_empty() const;

/// noload_decls_begin/end - Iterate over the declarations stored in this
/// context that are currently loaded; don't attempt to retrieve anything
/// from an external source.
decl_range noload_decls() const {
  return decl_range(noload_decls_begin(), noload_decls_end());
}
decl_iterator noload_decls_begin() const { return decl_iterator(FirstDecl); }
decl_iterator noload_decls_end() const { return decl_iterator(); }

/// specific_decl_iterator - Iterates over a subrange of
/// declarations stored in a DeclContext, providing only those that
/// are of type SpecificDecl (or a class derived from it). This
/// iterator is used, for example, to provide iteration over just
/// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
template<typename SpecificDecl>
class specific_decl_iterator {
  /// Current - The current, underlying declaration iterator, which
  /// will either be NULL or will point to a declaration of
  /// type SpecificDecl.
  DeclContext::decl_iterator Current;

  /// SkipToNextDecl - Advances the current position up to the next
  /// declaration of type SpecificDecl that also meets the criteria
  /// required by Acceptable.
  void SkipToNextDecl() {
    while (*Current && !isa<SpecificDecl>(*Current))
      ++Current;
  }

public:
  using value_type = SpecificDecl *;
  // TODO: Add reference and pointer types (with some appropriate proxy type)
  // if we ever have a need for them.
  using reference = void;
  using pointer = void;
  using difference_type =
      std::iterator_traits<DeclContext::decl_iterator>::difference_type;
  using iterator_category = std::forward_iterator_tag;

  specific_decl_iterator() = default;

  /// specific_decl_iterator - Construct a new iterator over a
  /// subset of the declarations the range [C,
  /// end-of-declarations). If A is non-NULL, it is a pointer to a
  /// member function of SpecificDecl that should return true for
  /// all of the SpecificDecl instances that will be in the subset
  /// of iterators. For example, if you want Objective-C instance
  /// methods, SpecificDecl will be ObjCMethodDecl and A will be
  /// &ObjCMethodDecl::isInstanceMethod.
  explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
    SkipToNextDecl();
  }

  value_type operator*() const { return cast<SpecificDecl>(*Current); }

  // This doesn't meet the iterator requirements, but it's convenient
  value_type operator->() const { return **this; }

  specific_decl_iterator& operator++() {
    ++Current;
    SkipToNextDecl();
    return *this;
  }

  specific_decl_iterator operator++(int) {
    specific_decl_iterator tmp(*this);
    ++(*this);
    return tmp;
  }

  friend bool operator==(const specific_decl_iterator& x,
                         const specific_decl_iterator& y) {
    return x.Current == y.Current;
  }

  friend bool operator!=(const specific_decl_iterator& x,
                         const specific_decl_iterator& y) {
    return x.Current != y.Current;
  }
};

/// Iterates over a filtered subrange of declarations stored
/// in a DeclContext.
///
/// This iterator visits only those declarations that are of type
/// SpecificDecl (or a class derived from it) and that meet some
/// additional run-time criteria. This iterator is used, for
/// example, to provide access to the instance methods within an
/// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
/// Acceptable = ObjCMethodDecl::isInstanceMethod).
template<typename SpecificDecl, bool (SpecificDecl::*Acceptable)() const>
class filtered_decl_iterator {
  /// Current - The current, underlying declaration iterator, which
  /// will either be NULL or will point to a declaration of
  /// type SpecificDecl.
  DeclContext::decl_iterator Current;

  /// SkipToNextDecl - Advances the current position up to the next
  /// declaration of type SpecificDecl that also meets the criteria
  /// required by Acceptable.
  void SkipToNextDecl() {
    while (*Current &&
           (!isa<SpecificDecl>(*Current) ||
            (Acceptable && !(cast<SpecificDecl>(*Current)->*Acceptable)())))
      ++Current;
  }

public:
  using value_type = SpecificDecl *;
  // TODO: Add reference and pointer types (with some appropriate proxy type)
  // if we ever have a need for them.
  using reference = void;
  using pointer = void;
  using difference_type =
      std::iterator_traits<DeclContext::decl_iterator>::difference_type;
  using iterator_category = std::forward_iterator_tag;

  filtered_decl_iterator() = default;

  /// filtered_decl_iterator - Construct a new iterator over a
  /// subset of the declarations the range [C,
  /// end-of-declarations). If A is non-NULL, it is a pointer to a
  /// member function of SpecificDecl that should return true for
  /// all of the SpecificDecl instances that will be in the subset
  /// of iterators. For example, if you want Objective-C instance
  /// methods, SpecificDecl will be ObjCMethodDecl and A will be
  /// &ObjCMethodDecl::isInstanceMethod.
  explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
    SkipToNextDecl();
  }

  value_type operator*() const { return cast<SpecificDecl>(*Current); }
  value_type operator->() const { return cast<SpecificDecl>(*Current); }

  filtered_decl_iterator& operator++() {
    ++Current;
    SkipToNextDecl();
    return *this;
  }

  filtered_decl_iterator operator++(int) {
    filtered_decl_iterator tmp(*this);
    ++(*this);
    return tmp;
  }

  friend bool operator==(const filtered_decl_iterator& x,
                         const filtered_decl_iterator& y) {
    return x.Current == y.Current;
  }

  friend bool operator!=(const filtered_decl_iterator& x,
                         const filtered_decl_iterator& y) {
    return x.Current != y.Current;
  }
};

/// Add the declaration D into this context.
///
/// This routine should be invoked when the declaration D has first
/// been declared, to place D into the context where it was
/// (lexically) defined. Every declaration must be added to one
/// (and only one!) context, where it can be visited via
/// [decls_begin(), decls_end()). Once a declaration has been added
/// to its lexical context, the corresponding DeclContext owns the
/// declaration.
///
/// If D is also a NamedDecl, it will be made visible within its
/// semantic context via makeDeclVisibleInContext.
void addDecl(Decl *D);

/// Add the declaration D into this context, but suppress
/// searches for external declarations with the same name.
///
/// Although analogous in function to addDecl, this removes an
/// important check.  This is only useful if the Decl is being
/// added in response to an external search; in all other cases,
/// addDecl() is the right function to use.
/// See the ASTImporter for use cases.
void addDeclInternal(Decl *D);

/// Add the declaration D to this context without modifying
/// any lookup tables.
///
/// This is useful for some operations in dependent contexts where
/// the semantic context might not be dependent;  this basically
/// only happens with friends.
void addHiddenDecl(Decl *D);

/// Removes a declaration from this context.
void removeDecl(Decl *D);

/// Checks whether a declaration is in this context.
bool containsDecl(Decl *D) const;

/// Checks whether a declaration is in this context.
/// This also loads the Decls from the external source before the check.
bool containsDeclAndLoad(Decl *D) const;

using lookup_result = DeclContextLookupResult;
using lookup_iterator = lookup_result::iterator;

/// lookup - Find the declarations (if any) with the given Name in
/// this context. Returns a range of iterators that contains all of
/// the declarations with this name, with object, function, member,
/// and enumerator names preceding any tag name. Note that this
/// routine will not look into parent contexts.
lookup_result lookup(DeclarationName Name) const;

/// Find the declarations with the given name that are visible
/// within this context; don't attempt to retrieve anything from an
/// external source.
lookup_result noload_lookup(DeclarationName Name);

/// A simplistic name lookup mechanism that performs name lookup
/// into this declaration context without consulting the external source.
///
/// This function should almost never be used, because it subverts the
/// usual relationship between a DeclContext and the external source.
/// See the ASTImporter for the (few, but important) use cases.
///
/// FIXME: This is very inefficient; replace uses of it with uses of
/// noload_lookup.
void localUncachedLookup(DeclarationName Name,
                         SmallVectorImpl<NamedDecl *> &Results);

/// Makes a declaration visible within this context.
///
/// This routine makes the declaration D visible to name lookup
/// within this context and, if this is a transparent context,
/// within its parent contexts up to the first enclosing
/// non-transparent context. Making a declaration visible within a
/// context does not transfer ownership of a declaration, and a
/// declaration can be visible in many contexts that aren't its
/// lexical context.
///
/// If D is a redeclaration of an existing declaration that is
/// visible from this context, as determined by
/// NamedDecl::declarationReplaces, the previous declaration will be
/// replaced with D.
void makeDeclVisibleInContext(NamedDecl *D);

/// all_lookups_iterator - An iterator that provides a view over the results
/// of looking up every possible name.
class all_lookups_iterator;

using lookups_range = llvm::iterator_range<all_lookups_iterator>;

lookups_range lookups() const;
// Like lookups(), but avoids loading external declarations.
// If PreserveInternalState, avoids building lookup data structures too.
lookups_range noload_lookups(bool PreserveInternalState) const;

/// Iterators over all possible lookups within this context.
all_lookups_iterator lookups_begin() const;
all_lookups_iterator lookups_end() const;

/// Iterators over all possible lookups within this context that are
/// currently loaded; don't attempt to retrieve anything from an external
/// source.
all_lookups_iterator noload_lookups_begin() const;
all_lookups_iterator noload_lookups_end() const;

struct udir_iterator;

using udir_iterator_base =
    llvm::iterator_adaptor_base<udir_iterator, lookup_iterator,
                                typename lookup_iterator::iterator_category,
                                UsingDirectiveDecl *>;

struct udir_iterator : udir_iterator_base {
  udir_iterator(lookup_iterator I) : udir_iterator_base(I) {}

  UsingDirectiveDecl *operator*() const;
};

using udir_range = llvm::iterator_range<udir_iterator>;

udir_range using_directives() const;

// These are all defined in DependentDiagnostic.h.
class ddiag_iterator;

using ddiag_range = llvm::iterator_range<DeclContext::ddiag_iterator>;

inline ddiag_range ddiags() const;

// Low-level accessors

/// Mark that there are external lexical declarations that we need
/// to include in our lookup table (and that are not available as external
/// visible lookups). These extra lookup results will be found by walking
/// the lexical declarations of this context. This should be used only if
/// setHasExternalLexicalStorage() has been called on any decl context for
/// which this is the primary context.
void setMustBuildLookupTable() {
  assert(this == getPrimaryContext() &&((void)0)
         "should only be called on primary context")((void)0);
  DeclContextBits.HasLazyExternalLexicalLookups = true;
}

/// Retrieve the internal representation of the lookup structure.
/// This may omit some names if we are lazily building the structure.
StoredDeclsMap *getLookupPtr() const { return LookupPtr; }

/// Ensure the lookup structure is fully-built and return it.
StoredDeclsMap *buildLookup();

/// Whether this DeclContext has external storage containing
/// additional declarations that are lexically in this context.
bool hasExternalLexicalStorage() const {
  return DeclContextBits.ExternalLexicalStorage;
}

/// State whether this DeclContext has external storage for
/// declarations lexically in this context.
void setHasExternalLexicalStorage(bool ES = true) const {
  DeclContextBits.ExternalLexicalStorage = ES;
}

/// Whether this DeclContext has external storage containing
/// additional declarations that are visible in this context.
bool hasExternalVisibleStorage() const {
  return DeclContextBits.ExternalVisibleStorage;
}

/// State whether this DeclContext has external storage for
/// declarations visible in this context.
void setHasExternalVisibleStorage(bool ES = true) const {
  DeclContextBits.ExternalVisibleStorage = ES;
  if (ES && LookupPtr)
    DeclContextBits.NeedToReconcileExternalVisibleStorage = true;
}

/// Determine whether the given declaration is stored in the list of
/// declarations lexically within this context.
bool isDeclInLexicalTraversal(const Decl *D) const {
  return D && (D->NextInContextAndBits.getPointer() || D == FirstDecl ||
               D == LastDecl);
}

bool setUseQualifiedLookup(bool use = true) const {
  bool old_value = DeclContextBits.UseQualifiedLookup;
  DeclContextBits.UseQualifiedLookup = use;
  return old_value;
}

bool shouldUseQualifiedLookup() const {
  return DeclContextBits.UseQualifiedLookup;
}

static bool classof(const Decl *D);
static bool classof(const DeclContext *D) { return true; }

void dumpDeclContext() const;
void dumpLookups() const;
void dumpLookups(llvm::raw_ostream &OS, bool DumpDecls = false,
                 bool Deserialize = false) const;

2473private:
/// Whether this declaration context has had externally visible
/// storage added since the last lookup. In this case, \c LookupPtr's
/// invariant may not hold and needs to be fixed before we perform
/// another lookup.
bool hasNeedToReconcileExternalVisibleStorage() const {
  return DeclContextBits.NeedToReconcileExternalVisibleStorage;
}

/// State that this declaration context has had externally visible
/// storage added since the last lookup. In this case, \c LookupPtr's
/// invariant may not hold and needs to be fixed before we perform
/// another lookup.
void setNeedToReconcileExternalVisibleStorage(bool Need = true) const {
  DeclContextBits.NeedToReconcileExternalVisibleStorage = Need;
}

/// If \c true, this context may have local lexical declarations
/// that are missing from the lookup table.
bool hasLazyLocalLexicalLookups() const {
  return DeclContextBits.HasLazyLocalLexicalLookups;
}

/// If \c true, this context may have local lexical declarations
/// that are missing from the lookup table.
void setHasLazyLocalLexicalLookups(bool HasLLLL = true) const {
  DeclContextBits.HasLazyLocalLexicalLookups = HasLLLL;
}

/// If \c true, the external source may have lexical declarations
/// that are missing from the lookup table.
bool hasLazyExternalLexicalLookups() const {
  return DeclContextBits.HasLazyExternalLexicalLookups;
}

/// If \c true, the external source may have lexical declarations
/// that are missing from the lookup table.
void setHasLazyExternalLexicalLookups(bool HasLELL = true) const {
  DeclContextBits.HasLazyExternalLexicalLookups = HasLELL;
}

void reconcileExternalVisibleStorage() const;
bool LoadLexicalDeclsFromExternalStorage() const;

/// Makes a declaration visible within this context, but
/// suppresses searches for external declarations with the same
/// name.
///
/// Analogous to makeDeclVisibleInContext, but for the exclusive
/// use of addDeclInternal().
void makeDeclVisibleInContextInternal(NamedDecl *D);

StoredDeclsMap *CreateStoredDeclsMap(ASTContext &C) const;

void loadLazyLocalLexicalLookups();
void buildLookupImpl(DeclContext *DCtx, bool Internal);
void makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
                                       bool Rediscoverable);
void makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal);
2532};

2534inline bool Decl::isTemplateParameter() const {
return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm ||
       getKind() == TemplateTemplateParm;
2537}

2539// Specialization selected when ToTy is not a known subclass of DeclContext.
2540template <class ToTy,
        bool IsKnownSubtype = ::std::is_base_of<DeclContext, ToTy>::value>
2542struct cast_convert_decl_context {
static const ToTy *doit(const DeclContext *Val) {
  return static_cast<const ToTy*>(Decl::castFromDeclContext(Val));
}

static ToTy *doit(DeclContext *Val) {
  return static_cast<ToTy*>(Decl::castFromDeclContext(Val));
}
2550};

2552// Specialization selected when ToTy is a known subclass of DeclContext.
2553template <class ToTy>
2554struct cast_convert_decl_context<ToTy, true> {
static const ToTy *doit(const DeclContext *Val) {
  return static_cast<const ToTy*>(Val);
}

static ToTy *doit(DeclContext *Val) {
  return static_cast<ToTy*>(Val);
}
2562};

2564} // namespace clang

2566namespace llvm {

2568/// isa<T>(DeclContext*)
2569template <typename To>
2570struct isa_impl<To, ::clang::DeclContext> {
static bool doit(const ::clang::DeclContext &Val) {
  return To::classofKind(Val.getDeclKind());
}
2574};

2576/// cast<T>(DeclContext*)
2577template<class ToTy>
2578struct cast_convert_val<ToTy,
                      const ::clang::DeclContext,const ::clang::DeclContext> {
static const ToTy &doit(const ::clang::DeclContext &Val) {
  return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
}
2583};

2585template<class ToTy>
2586struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
static ToTy &doit(::clang::DeclContext &Val) {
  return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
}
2590};

2592template<class ToTy>
2593struct cast_convert_val<ToTy,
                   const ::clang::DeclContext*, const ::clang::DeclContext*> {
static const ToTy *doit(const ::clang::DeclContext *Val) {
  return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
}
2598};

2600template<class ToTy>
2601struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*> {
static ToTy *doit(::clang::DeclContext *Val) {
  return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
}
2605};

2607/// Implement cast_convert_val for Decl -> DeclContext conversions.
2608template<class FromTy>
2609struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
static ::clang::DeclContext &doit(const FromTy &Val) {
  return *FromTy::castToDeclContext(&Val);
}
2613};

2615template<class FromTy>
2616struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
static ::clang::DeclContext *doit(const FromTy *Val) {
  return FromTy::castToDeclContext(Val);
}
2620};

2622template<class FromTy>
2623struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
static const ::clang::DeclContext &doit(const FromTy &Val) {
  return *FromTy::castToDeclContext(&Val);
}
2627};

2629template<class FromTy>
2630struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
static const ::clang::DeclContext *doit(const FromTy *Val) {
  return FromTy::castToDeclContext(Val);
}
2634};

2636} // namespace llvm

2638#endif // LLVM_CLANG_AST_DECLBASE_H