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

Bug Summary

File:	src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/lib/Sema/SemaDeclCXX.cpp
Warning:	line 15375, column 10 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 SemaDeclCXX.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/SemaDeclCXX.cpp

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

→

1//===------ SemaDeclCXX.cpp - Semantic Analysis for C++ 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 C++ declarations.
10//
11//===----------------------------------------------------------------------===//

13#include "clang/AST/ASTConsumer.h"
14#include "clang/AST/ASTContext.h"
15#include "clang/AST/ASTLambda.h"
16#include "clang/AST/ASTMutationListener.h"
17#include "clang/AST/CXXInheritance.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/ComparisonCategories.h"
20#include "clang/AST/EvaluatedExprVisitor.h"
21#include "clang/AST/ExprCXX.h"
22#include "clang/AST/RecordLayout.h"
23#include "clang/AST/RecursiveASTVisitor.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/AST/TypeLoc.h"
26#include "clang/AST/TypeOrdering.h"
27#include "clang/Basic/AttributeCommonInfo.h"
28#include "clang/Basic/PartialDiagnostic.h"
29#include "clang/Basic/TargetInfo.h"
30#include "clang/Lex/LiteralSupport.h"
31#include "clang/Lex/Preprocessor.h"
32#include "clang/Sema/CXXFieldCollector.h"
33#include "clang/Sema/DeclSpec.h"
34#include "clang/Sema/Initialization.h"
35#include "clang/Sema/Lookup.h"
36#include "clang/Sema/ParsedTemplate.h"
37#include "clang/Sema/Scope.h"
38#include "clang/Sema/ScopeInfo.h"
39#include "clang/Sema/SemaInternal.h"
40#include "clang/Sema/Template.h"
41#include "llvm/ADT/ScopeExit.h"
42#include "llvm/ADT/SmallString.h"
43#include "llvm/ADT/STLExtras.h"
44#include "llvm/ADT/StringExtras.h"
45#include <map>
46#include <set>

48using namespace clang;

50//===----------------------------------------------------------------------===//
51// CheckDefaultArgumentVisitor
52//===----------------------------------------------------------------------===//

54namespace {
55/// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
56/// the default argument of a parameter to determine whether it
57/// contains any ill-formed subexpressions. For example, this will
58/// diagnose the use of local variables or parameters within the
59/// default argument expression.
60class CheckDefaultArgumentVisitor
  : public ConstStmtVisitor<CheckDefaultArgumentVisitor, bool> {
Sema &S;
const Expr *DefaultArg;

65public:
CheckDefaultArgumentVisitor(Sema &S, const Expr *DefaultArg)
    : S(S), DefaultArg(DefaultArg) {}

bool VisitExpr(const Expr *Node);
bool VisitDeclRefExpr(const DeclRefExpr *DRE);
bool VisitCXXThisExpr(const CXXThisExpr *ThisE);
bool VisitLambdaExpr(const LambdaExpr *Lambda);
bool VisitPseudoObjectExpr(const PseudoObjectExpr *POE);
74};

76/// VisitExpr - Visit all of the children of this expression.
77bool CheckDefaultArgumentVisitor::VisitExpr(const Expr *Node) {
bool IsInvalid = false;
for (const Stmt *SubStmt : Node->children())
  IsInvalid |= Visit(SubStmt);
return IsInvalid;
82}

84/// VisitDeclRefExpr - Visit a reference to a declaration, to
85/// determine whether this declaration can be used in the default
86/// argument expression.
87bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(const DeclRefExpr *DRE) {
const NamedDecl *Decl = DRE->getDecl();
if (const auto *Param = dyn_cast<ParmVarDecl>(Decl)) {
  // C++ [dcl.fct.default]p9:
  //   [...] parameters of a function shall not be used in default
  //   argument expressions, even if they are not evaluated. [...]
  //
  // C++17 [dcl.fct.default]p9 (by CWG 2082):
  //   [...] A parameter shall not appear as a potentially-evaluated
  //   expression in a default argument. [...]
  //
  if (DRE->isNonOdrUse() != NOUR_Unevaluated)
    return S.Diag(DRE->getBeginLoc(),
                  diag::err_param_default_argument_references_param)
           << Param->getDeclName() << DefaultArg->getSourceRange();
} else if (const auto *VDecl = dyn_cast<VarDecl>(Decl)) {
  // C++ [dcl.fct.default]p7:
  //   Local variables shall not be used in default argument
  //   expressions.
  //
  // C++17 [dcl.fct.default]p7 (by CWG 2082):
  //   A local variable shall not appear as a potentially-evaluated
  //   expression in a default argument.
  //
  // C++20 [dcl.fct.default]p7 (DR as part of P0588R1, see also CWG 2346):
  //   Note: A local variable cannot be odr-used (6.3) in a default argument.
  //
  if (VDecl->isLocalVarDecl() && !DRE->isNonOdrUse())
    return S.Diag(DRE->getBeginLoc(),
                  diag::err_param_default_argument_references_local)
           << VDecl->getDeclName() << DefaultArg->getSourceRange();
}

return false;
121}

123/// VisitCXXThisExpr - Visit a C++ "this" expression.
124bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(const CXXThisExpr *ThisE) {
// C++ [dcl.fct.default]p8:
//   The keyword this shall not be used in a default argument of a
//   member function.
return S.Diag(ThisE->getBeginLoc(),
              diag::err_param_default_argument_references_this)
       << ThisE->getSourceRange();
131}

133bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(
  const PseudoObjectExpr *POE) {
bool Invalid = false;
for (const Expr *E : POE->semantics()) {
  // Look through bindings.
  if (const auto *OVE = dyn_cast<OpaqueValueExpr>(E)) {
    E = OVE->getSourceExpr();
    assert(E && "pseudo-object binding without source expression?")((void)0);
  }

  Invalid |= Visit(E);
}
return Invalid;
146}

148bool CheckDefaultArgumentVisitor::VisitLambdaExpr(const LambdaExpr *Lambda) {
// C++11 [expr.lambda.prim]p13:
//   A lambda-expression appearing in a default argument shall not
//   implicitly or explicitly capture any entity.
if (Lambda->capture_begin() == Lambda->capture_end())
  return false;

return S.Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
156}
157} // namespace

159void
160Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
                                               const CXXMethodDecl *Method) {
// If we have an MSAny spec already, don't bother.
if (!Method || ComputedEST == EST_MSAny)
  return;

const FunctionProtoType *Proto
  = Method->getType()->getAs<FunctionProtoType>();
Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
if (!Proto)
  return;

ExceptionSpecificationType EST = Proto->getExceptionSpecType();

// If we have a throw-all spec at this point, ignore the function.
if (ComputedEST == EST_None)
  return;

if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
  EST = EST_BasicNoexcept;

switch (EST) {
case EST_Unparsed:
case EST_Uninstantiated:
case EST_Unevaluated:
  llvm_unreachable("should not see unresolved exception specs here")__builtin_unreachable();

// If this function can throw any exceptions, make a note of that.
case EST_MSAny:
case EST_None:
  // FIXME: Whichever we see last of MSAny and None determines our result.
  // We should make a consistent, order-independent choice here.
  ClearExceptions();
  ComputedEST = EST;
  return;
case EST_NoexceptFalse:
  ClearExceptions();
  ComputedEST = EST_None;
  return;
// FIXME: If the call to this decl is using any of its default arguments, we
// need to search them for potentially-throwing calls.
// If this function has a basic noexcept, it doesn't affect the outcome.
case EST_BasicNoexcept:
case EST_NoexceptTrue:
case EST_NoThrow:
  return;
// If we're still at noexcept(true) and there's a throw() callee,
// change to that specification.
case EST_DynamicNone:
  if (ComputedEST == EST_BasicNoexcept)
    ComputedEST = EST_DynamicNone;
  return;
case EST_DependentNoexcept:
  llvm_unreachable(__builtin_unreachable()
      "should not generate implicit declarations for dependent cases")__builtin_unreachable();
case EST_Dynamic:
  break;
}
assert(EST == EST_Dynamic && "EST case not considered earlier.")((void)0);
assert(ComputedEST != EST_None &&((void)0)
       "Shouldn't collect exceptions when throw-all is guaranteed.")((void)0);
ComputedEST = EST_Dynamic;
// Record the exceptions in this function's exception specification.
for (const auto &E : Proto->exceptions())
  if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
    Exceptions.push_back(E);
226}

228void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
if (!S || ComputedEST == EST_MSAny)
  return;

// FIXME:
//
// C++0x [except.spec]p14:
//   [An] implicit exception-specification specifies the type-id T if and
// only if T is allowed by the exception-specification of a function directly
// invoked by f's implicit definition; f shall allow all exceptions if any
// function it directly invokes allows all exceptions, and f shall allow no
// exceptions if every function it directly invokes allows no exceptions.
//
// Note in particular that if an implicit exception-specification is generated
// for a function containing a throw-expression, that specification can still
// be noexcept(true).
//
// Note also that 'directly invoked' is not defined in the standard, and there
// is no indication that we should only consider potentially-evaluated calls.
//
// Ultimately we should implement the intent of the standard: the exception
// specification should be the set of exceptions which can be thrown by the
// implicit definition. For now, we assume that any non-nothrow expression can
// throw any exception.

if (Self->canThrow(S))
  ComputedEST = EST_None;
255}

257ExprResult Sema::ConvertParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
                                           SourceLocation EqualLoc) {
if (RequireCompleteType(Param->getLocation(), Param->getType(),
                        diag::err_typecheck_decl_incomplete_type))
  return true;

// C++ [dcl.fct.default]p5
//   A default argument expression is implicitly converted (clause
//   4) to the parameter type. The default argument expression has
//   the same semantic constraints as the initializer expression in
//   a declaration of a variable of the parameter type, using the
//   copy-initialization semantics (8.5).
InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
                                                                  Param);
InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
                                                         EqualLoc);
InitializationSequence InitSeq(*this, Entity, Kind, Arg);
ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
if (Result.isInvalid())
  return true;
Arg = Result.getAs<Expr>();

CheckCompletedExpr(Arg, EqualLoc);
Arg = MaybeCreateExprWithCleanups(Arg);

return Arg;
283}

285void Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
                                 SourceLocation EqualLoc) {
// Add the default argument to the parameter
Param->setDefaultArg(Arg);

// We have already instantiated this parameter; provide each of the
// instantiations with the uninstantiated default argument.
UnparsedDefaultArgInstantiationsMap::iterator InstPos
  = UnparsedDefaultArgInstantiations.find(Param);
if (InstPos != UnparsedDefaultArgInstantiations.end()) {
  for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
    InstPos->second[I]->setUninstantiatedDefaultArg(Arg);

  // We're done tracking this parameter's instantiations.
  UnparsedDefaultArgInstantiations.erase(InstPos);
}
301}

303/// ActOnParamDefaultArgument - Check whether the default argument
304/// provided for a function parameter is well-formed. If so, attach it
305/// to the parameter declaration.
306void
307Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
                              Expr *DefaultArg) {
if (!param || !DefaultArg)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
UnparsedDefaultArgLocs.erase(Param);

auto Fail = [&] {
  Param->setInvalidDecl();
  Param->setDefaultArg(new (Context) OpaqueValueExpr(
      EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
};

// Default arguments are only permitted in C++
if (!getLangOpts().CPlusPlus) {
  Diag(EqualLoc, diag::err_param_default_argument)
    << DefaultArg->getSourceRange();
  return Fail();
}

// Check for unexpanded parameter packs.
if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
  return Fail();
}

// C++11 [dcl.fct.default]p3
//   A default argument expression [...] shall not be specified for a
//   parameter pack.
if (Param->isParameterPack()) {
  Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
      << DefaultArg->getSourceRange();
  // Recover by discarding the default argument.
  Param->setDefaultArg(nullptr);
  return;
}

ExprResult Result = ConvertParamDefaultArgument(Param, DefaultArg, EqualLoc);
if (Result.isInvalid())
  return Fail();

DefaultArg = Result.getAs<Expr>();

// Check that the default argument is well-formed
CheckDefaultArgumentVisitor DefaultArgChecker(*this, DefaultArg);
if (DefaultArgChecker.Visit(DefaultArg))
  return Fail();

SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
356}

358/// ActOnParamUnparsedDefaultArgument - We've seen a default
359/// argument for a function parameter, but we can't parse it yet
360/// because we're inside a class definition. Note that this default
361/// argument will be parsed later.
362void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
                                           SourceLocation EqualLoc,
                                           SourceLocation ArgLoc) {
if (!param)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setUnparsedDefaultArg();
UnparsedDefaultArgLocs[Param] = ArgLoc;
371}

373/// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
374/// the default argument for the parameter param failed.
375void Sema::ActOnParamDefaultArgumentError(Decl *param,
                                        SourceLocation EqualLoc) {
if (!param)
  return;

ParmVarDecl *Param = cast<ParmVarDecl>(param);
Param->setInvalidDecl();
UnparsedDefaultArgLocs.erase(Param);
Param->setDefaultArg(new (Context) OpaqueValueExpr(
    EqualLoc, Param->getType().getNonReferenceType(), VK_PRValue));
385}

387/// CheckExtraCXXDefaultArguments - Check for any extra default
388/// arguments in the declarator, which is not a function declaration
389/// or definition and therefore is not permitted to have default
390/// arguments. This routine should be invoked for every declarator
391/// that is not a function declaration or definition.
392void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
// C++ [dcl.fct.default]p3
//   A default argument expression shall be specified only in the
//   parameter-declaration-clause of a function declaration or in a
//   template-parameter (14.1). It shall not be specified for a
//   parameter pack. If it is specified in a
//   parameter-declaration-clause, it shall not occur within a
//   declarator or abstract-declarator of a parameter-declaration.
bool MightBeFunction = D.isFunctionDeclarationContext();
for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
  DeclaratorChunk &chunk = D.getTypeObject(i);
  if (chunk.Kind == DeclaratorChunk::Function) {
    if (MightBeFunction) {
      // This is a function declaration. It can have default arguments, but
      // keep looking in case its return type is a function type with default
      // arguments.
      MightBeFunction = false;
      continue;
    }
    for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
         ++argIdx) {
      ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
      if (Param->hasUnparsedDefaultArg()) {
        std::unique_ptr<CachedTokens> Toks =
            std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
        SourceRange SR;
        if (Toks->size() > 1)
          SR = SourceRange((*Toks)[1].getLocation(),
                           Toks->back().getLocation());
        else
          SR = UnparsedDefaultArgLocs[Param];
        Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
          << SR;
      } else if (Param->getDefaultArg()) {
        Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
          << Param->getDefaultArg()->getSourceRange();
        Param->setDefaultArg(nullptr);
      }
    }
  } else if (chunk.Kind != DeclaratorChunk::Paren) {
    MightBeFunction = false;
  }
}
435}

437static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
return std::any_of(FD->param_begin(), FD->param_end(), [](ParmVarDecl *P) {
  return P->hasDefaultArg() && !P->hasInheritedDefaultArg();
});
441}

443/// MergeCXXFunctionDecl - Merge two declarations of the same C++
444/// function, once we already know that they have the same
445/// type. Subroutine of MergeFunctionDecl. Returns true if there was an
446/// error, false otherwise.
447bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
                              Scope *S) {
bool Invalid = false;

// The declaration context corresponding to the scope is the semantic
// parent, unless this is a local function declaration, in which case
// it is that surrounding function.
DeclContext *ScopeDC = New->isLocalExternDecl()
                           ? New->getLexicalDeclContext()
                           : New->getDeclContext();

// Find the previous declaration for the purpose of default arguments.
FunctionDecl *PrevForDefaultArgs = Old;
for (/**/; PrevForDefaultArgs;
     // Don't bother looking back past the latest decl if this is a local
     // extern declaration; nothing else could work.
     PrevForDefaultArgs = New->isLocalExternDecl()
                              ? nullptr
                              : PrevForDefaultArgs->getPreviousDecl()) {
  // Ignore hidden declarations.
  if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
    continue;

  if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
      !New->isCXXClassMember()) {
    // Ignore default arguments of old decl if they are not in
    // the same scope and this is not an out-of-line definition of
    // a member function.
    continue;
  }

  if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
    // If only one of these is a local function declaration, then they are
    // declared in different scopes, even though isDeclInScope may think
    // they're in the same scope. (If both are local, the scope check is
    // sufficient, and if neither is local, then they are in the same scope.)
    continue;
  }

  // We found the right previous declaration.
  break;
}

// C++ [dcl.fct.default]p4:
//   For non-template functions, default arguments can be added in
//   later declarations of a function in the same
//   scope. Declarations in different scopes have completely
//   distinct sets of default arguments. That is, declarations in
//   inner scopes do not acquire default arguments from
//   declarations in outer scopes, and vice versa. In a given
//   function declaration, all parameters subsequent to a
//   parameter with a default argument shall have default
//   arguments supplied in this or previous declarations. A
//   default argument shall not be redefined by a later
//   declaration (not even to the same value).
//
// C++ [dcl.fct.default]p6:
//   Except for member functions of class templates, the default arguments
//   in a member function definition that appears outside of the class
//   definition are added to the set of default arguments provided by the
//   member function declaration in the class definition.
for (unsigned p = 0, NumParams = PrevForDefaultArgs
                                     ? PrevForDefaultArgs->getNumParams()
                                     : 0;
     p < NumParams; ++p) {
  ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
  ParmVarDecl *NewParam = New->getParamDecl(p);

  bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
  bool NewParamHasDfl = NewParam->hasDefaultArg();

  if (OldParamHasDfl && NewParamHasDfl) {
    unsigned DiagDefaultParamID =
      diag::err_param_default_argument_redefinition;

    // MSVC accepts that default parameters be redefined for member functions
    // of template class. The new default parameter's value is ignored.
    Invalid = true;
    if (getLangOpts().MicrosoftExt) {
      CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
      if (MD && MD->getParent()->getDescribedClassTemplate()) {
        // Merge the old default argument into the new parameter.
        NewParam->setHasInheritedDefaultArg();
        if (OldParam->hasUninstantiatedDefaultArg())
          NewParam->setUninstantiatedDefaultArg(
                                    OldParam->getUninstantiatedDefaultArg());
        else
          NewParam->setDefaultArg(OldParam->getInit());
        DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
        Invalid = false;
      }
    }

    // FIXME: If we knew where the '=' was, we could easily provide a fix-it
    // hint here. Alternatively, we could walk the type-source information
    // for NewParam to find the last source location in the type... but it
    // isn't worth the effort right now. This is the kind of test case that
    // is hard to get right:
    //   int f(int);
    //   void g(int (*fp)(int) = f);
    //   void g(int (*fp)(int) = &f);
    Diag(NewParam->getLocation(), DiagDefaultParamID)
      << NewParam->getDefaultArgRange();

    // Look for the function declaration where the default argument was
    // actually written, which may be a declaration prior to Old.
    for (auto Older = PrevForDefaultArgs;
         OldParam->hasInheritedDefaultArg(); /**/) {
      Older = Older->getPreviousDecl();
      OldParam = Older->getParamDecl(p);
    }

    Diag(OldParam->getLocation(), diag::note_previous_definition)
      << OldParam->getDefaultArgRange();
  } else if (OldParamHasDfl) {
    // Merge the old default argument into the new parameter unless the new
    // function is a friend declaration in a template class. In the latter
    // case the default arguments will be inherited when the friend
    // declaration will be instantiated.
    if (New->getFriendObjectKind() == Decl::FOK_None ||
        !New->getLexicalDeclContext()->isDependentContext()) {
      // It's important to use getInit() here;  getDefaultArg()
      // strips off any top-level ExprWithCleanups.
      NewParam->setHasInheritedDefaultArg();
      if (OldParam->hasUnparsedDefaultArg())
        NewParam->setUnparsedDefaultArg();
      else if (OldParam->hasUninstantiatedDefaultArg())
        NewParam->setUninstantiatedDefaultArg(
                                     OldParam->getUninstantiatedDefaultArg());
      else
        NewParam->setDefaultArg(OldParam->getInit());
    }
  } else if (NewParamHasDfl) {
    if (New->getDescribedFunctionTemplate()) {
      // Paragraph 4, quoted above, only applies to non-template functions.
      Diag(NewParam->getLocation(),
           diag::err_param_default_argument_template_redecl)
        << NewParam->getDefaultArgRange();
      Diag(PrevForDefaultArgs->getLocation(),
           diag::note_template_prev_declaration)
          << false;
    } else if (New->getTemplateSpecializationKind()
                 != TSK_ImplicitInstantiation &&
               New->getTemplateSpecializationKind() != TSK_Undeclared) {
      // C++ [temp.expr.spec]p21:
      //   Default function arguments shall not be specified in a declaration
      //   or a definition for one of the following explicit specializations:
      //     - the explicit specialization of a function template;
      //     - the explicit specialization of a member function template;
      //     - the explicit specialization of a member function of a class
      //       template where the class template specialization to which the
      //       member function specialization belongs is implicitly
      //       instantiated.
      Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
        << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
        << New->getDeclName()
        << NewParam->getDefaultArgRange();
    } else if (New->getDeclContext()->isDependentContext()) {
      // C++ [dcl.fct.default]p6 (DR217):
      //   Default arguments for a member function of a class template shall
      //   be specified on the initial declaration of the member function
      //   within the class template.
      //
      // Reading the tea leaves a bit in DR217 and its reference to DR205
      // leads me to the conclusion that one cannot add default function
      // arguments for an out-of-line definition of a member function of a
      // dependent type.
      int WhichKind = 2;
      if (CXXRecordDecl *Record
            = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
        if (Record->getDescribedClassTemplate())
          WhichKind = 0;
        else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
          WhichKind = 1;
        else
          WhichKind = 2;
      }

      Diag(NewParam->getLocation(),
           diag::err_param_default_argument_member_template_redecl)
        << WhichKind
        << NewParam->getDefaultArgRange();
    }
  }
}

// DR1344: If a default argument is added outside a class definition and that
// default argument makes the function a special member function, the program
// is ill-formed. This can only happen for constructors.
if (isa<CXXConstructorDecl>(New) &&
    New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
  CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
                   OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
  if (NewSM != OldSM) {
    ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
    assert(NewParam->hasDefaultArg())((void)0);
    Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
      << NewParam->getDefaultArgRange() << NewSM;
    Diag(Old->getLocation(), diag::note_previous_declaration);
  }
}

const FunctionDecl *Def;
// C++11 [dcl.constexpr]p1: If any declaration of a function or function
// template has a constexpr specifier then all its declarations shall
// contain the constexpr specifier.
if (New->getConstexprKind() != Old->getConstexprKind()) {
  Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
      << New << static_cast<int>(New->getConstexprKind())
      << static_cast<int>(Old->getConstexprKind());
  Diag(Old->getLocation(), diag::note_previous_declaration);
  Invalid = true;
} else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
           Old->isDefined(Def) &&
           // If a friend function is inlined but does not have 'inline'
           // specifier, it is a definition. Do not report attribute conflict
           // in this case, redefinition will be diagnosed later.
           (New->isInlineSpecified() ||
            New->getFriendObjectKind() == Decl::FOK_None)) {
  // C++11 [dcl.fcn.spec]p4:
  //   If the definition of a function 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);
  Invalid = true;
}

// C++17 [temp.deduct.guide]p3:
//   Two deduction guide declarations in the same translation unit
//   for the same class template shall not have equivalent
//   parameter-declaration-clauses.
if (isa<CXXDeductionGuideDecl>(New) &&
    !New->isFunctionTemplateSpecialization() && isVisible(Old)) {
  Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
  Diag(Old->getLocation(), diag::note_previous_declaration);
}

// C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
// argument expression, that declaration shall be a definition and shall be
// the only declaration of the function or function template in the
// translation unit.
if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
    functionDeclHasDefaultArgument(Old)) {
  Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
  Diag(Old->getLocation(), diag::note_previous_declaration);
  Invalid = true;
}

// C++11 [temp.friend]p4 (DR329):
//   When a function is defined in a friend function declaration in a class
//   template, the function is instantiated when the function is odr-used.
//   The same restrictions on multiple declarations and definitions that
//   apply to non-template function declarations and definitions also apply
//   to these implicit definitions.
const FunctionDecl *OldDefinition = nullptr;
if (New->isThisDeclarationInstantiatedFromAFriendDefinition() &&
    Old->isDefined(OldDefinition, true))
  CheckForFunctionRedefinition(New, OldDefinition);

return Invalid;
707}

709NamedDecl *
710Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
                                 MultiTemplateParamsArg TemplateParamLists) {
assert(D.isDecompositionDeclarator())((void)0);
const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();

// The syntax only allows a decomposition declarator as a simple-declaration,
// a for-range-declaration, or a condition in Clang, but we parse it in more
// cases than that.
if (!D.mayHaveDecompositionDeclarator()) {
  Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
    << Decomp.getSourceRange();
  return nullptr;
}

if (!TemplateParamLists.empty()) {
  // FIXME: There's no rule against this, but there are also no rules that
  // would actually make it usable, so we reject it for now.
  Diag(TemplateParamLists.front()->getTemplateLoc(),
       diag::err_decomp_decl_template);
  return nullptr;
}

Diag(Decomp.getLSquareLoc(),
     !getLangOpts().CPlusPlus17
         ? diag::ext_decomp_decl
         : D.getContext() == DeclaratorContext::Condition
               ? diag::ext_decomp_decl_cond
               : diag::warn_cxx14_compat_decomp_decl)
    << Decomp.getSourceRange();

// The semantic context is always just the current context.
DeclContext *const DC = CurContext;

// C++17 [dcl.dcl]/8:
//   The decl-specifier-seq shall contain only the type-specifier auto
//   and cv-qualifiers.
// C++2a [dcl.dcl]/8:
//   If decl-specifier-seq contains any decl-specifier other than static,
//   thread_local, auto, or cv-qualifiers, the program is ill-formed.
auto &DS = D.getDeclSpec();
{
  SmallVector<StringRef, 8> BadSpecifiers;
  SmallVector<SourceLocation, 8> BadSpecifierLocs;
  SmallVector<StringRef, 8> CPlusPlus20Specifiers;
  SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
  if (auto SCS = DS.getStorageClassSpec()) {
    if (SCS == DeclSpec::SCS_static) {
      CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
      CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
    } else {
      BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
      BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
    }
  }
  if (auto TSCS = DS.getThreadStorageClassSpec()) {
    CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
    CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
  }
  if (DS.hasConstexprSpecifier()) {
    BadSpecifiers.push_back(
        DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
    BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
  }
  if (DS.isInlineSpecified()) {
    BadSpecifiers.push_back("inline");
    BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
  }
  if (!BadSpecifiers.empty()) {
    auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
    Err << (int)BadSpecifiers.size()
        << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
    // Don't add FixItHints to remove the specifiers; we do still respect
    // them when building the underlying variable.
    for (auto Loc : BadSpecifierLocs)
      Err << SourceRange(Loc, Loc);
  } else if (!CPlusPlus20Specifiers.empty()) {
    auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
                       getLangOpts().CPlusPlus20
                           ? diag::warn_cxx17_compat_decomp_decl_spec
                           : diag::ext_decomp_decl_spec);
    Warn << (int)CPlusPlus20Specifiers.size()
         << llvm::join(CPlusPlus20Specifiers.begin(),
                       CPlusPlus20Specifiers.end(), " ");
    for (auto Loc : CPlusPlus20SpecifierLocs)
      Warn << SourceRange(Loc, Loc);
  }
  // We can't recover from it being declared as a typedef.
  if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
    return nullptr;
}

// C++2a [dcl.struct.bind]p1:
//   A cv that includes volatile is deprecated
if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
    getLangOpts().CPlusPlus20)
  Diag(DS.getVolatileSpecLoc(),
       diag::warn_deprecated_volatile_structured_binding);

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

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

// The syntax only allows a single ref-qualifier prior to the decomposition
// declarator. No other declarator chunks are permitted. Also check the type
// specifier here.
if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
    D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
    (D.getNumTypeObjects() == 1 &&
     D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
  Diag(Decomp.getLSquareLoc(),
       (D.hasGroupingParens() ||
        (D.getNumTypeObjects() &&
         D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
           ? diag::err_decomp_decl_parens
           : diag::err_decomp_decl_type)
      << R;

  // In most cases, there's no actual problem with an explicitly-specified
  // type, but a function type won't work here, and ActOnVariableDeclarator
  // shouldn't be called for such a type.
  if (R->isFunctionType())
    D.setInvalidType();
}

// Build the BindingDecls.
SmallVector<BindingDecl*, 8> Bindings;

// Build the BindingDecls.
for (auto &B : D.getDecompositionDeclarator().bindings()) {
  // Check for name conflicts.
  DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
  LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                        ForVisibleRedeclaration);
  LookupName(Previous, S,
             /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());

  // It's not permitted to shadow a template parameter name.
  if (Previous.isSingleResult() &&
      Previous.getFoundDecl()->isTemplateParameter()) {
    DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
                                    Previous.getFoundDecl());
    Previous.clear();
  }

  auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);

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

  bool ConsiderLinkage = DC->isFunctionOrMethod() &&
                         DS.getStorageClassSpec() == DeclSpec::SCS_extern;
  FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
                       /*AllowInlineNamespace*/false);

  if (!Previous.empty()) {
    auto *Old = Previous.getRepresentativeDecl();
    Diag(B.NameLoc, diag::err_redefinition) << B.Name;
    Diag(Old->getLocation(), diag::note_previous_definition);
  } else if (ShadowedDecl && !D.isRedeclaration()) {
    CheckShadow(BD, ShadowedDecl, Previous);
  }
  PushOnScopeChains(BD, S, true);
  Bindings.push_back(BD);
  ParsingInitForAutoVars.insert(BD);
}

// There are no prior lookup results for the variable itself, because it
// is unnamed.
DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
                             Decomp.getLSquareLoc());
LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
                      ForVisibleRedeclaration);

// Build the variable that holds the non-decomposed object.
bool AddToScope = true;
NamedDecl *New =
    ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
                            MultiTemplateParamsArg(), AddToScope, Bindings);
if (AddToScope) {
  S->AddDecl(New);
  CurContext->addHiddenDecl(New);
}

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

return New;
902}

904static bool checkSimpleDecomposition(
  Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
  QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
  llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
if ((int64_t)Bindings.size() != NumElems) {
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size()
      << (unsigned)NumElems.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
      << toString(NumElems, 10) << (NumElems < Bindings.size());
  return true;
}

unsigned I = 0;
for (auto *B : Bindings) {
  SourceLocation Loc = B->getLocation();
  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;
  E = GetInit(Loc, E.get(), I++);
  if (E.isInvalid())
    return true;
  B->setBinding(ElemType, E.get());
}

return false;
929}

931static bool checkArrayLikeDecomposition(Sema &S,
                                      ArrayRef<BindingDecl *> Bindings,
                                      ValueDecl *Src, QualType DecompType,
                                      const llvm::APSInt &NumElems,
                                      QualType ElemType) {
return checkSimpleDecomposition(
    S, Bindings, Src, DecompType, NumElems, ElemType,
    [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
      ExprResult E = S.ActOnIntegerConstant(Loc, I);
      if (E.isInvalid())
        return ExprError();
      return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
    });
944}

946static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                  ValueDecl *Src, QualType DecompType,
                                  const ConstantArrayType *CAT) {
return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
                                   llvm::APSInt(CAT->getSize()),
                                   CAT->getElementType());
952}

954static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                   ValueDecl *Src, QualType DecompType,
                                   const VectorType *VT) {
return checkArrayLikeDecomposition(
    S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
    S.Context.getQualifiedType(VT->getElementType(),
                               DecompType.getQualifiers()));
961}

963static bool checkComplexDecomposition(Sema &S,
                                    ArrayRef<BindingDecl *> Bindings,
                                    ValueDecl *Src, QualType DecompType,
                                    const ComplexType *CT) {
return checkSimpleDecomposition(
    S, Bindings, Src, DecompType, llvm::APSInt::get(2),
    S.Context.getQualifiedType(CT->getElementType(),
                               DecompType.getQualifiers()),
    [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
      return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
    });
974}

976static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
                                   TemplateArgumentListInfo &Args,
                                   const TemplateParameterList *Params) {
SmallString<128> SS;
llvm::raw_svector_ostream OS(SS);
bool First = true;
unsigned I = 0;
for (auto &Arg : Args.arguments()) {
  if (!First)
    OS << ", ";
  Arg.getArgument().print(
      PrintingPolicy, OS,
      TemplateParameterList::shouldIncludeTypeForArgument(Params, I));
  First = false;
  I++;
}
return std::string(OS.str());
993}

995static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
                                   SourceLocation Loc, StringRef Trait,
                                   TemplateArgumentListInfo &Args,
                                   unsigned DiagID) {
auto DiagnoseMissing = [&] {
  if (DiagID)
    S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
                                             Args, /*Params*/ nullptr);
  return true;
};

// FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
NamespaceDecl *Std = S.getStdNamespace();
if (!Std)
  return DiagnoseMissing();

// Look up the trait itself, within namespace std. We can diagnose various
// problems with this lookup even if we've been asked to not diagnose a
// missing specialization, because this can only fail if the user has been
// declaring their own names in namespace std or we don't support the
// standard library implementation in use.
LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
                    Loc, Sema::LookupOrdinaryName);
if (!S.LookupQualifiedName(Result, Std))
  return DiagnoseMissing();
if (Result.isAmbiguous())
  return true;

ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
if (!TraitTD) {
  Result.suppressDiagnostics();
  NamedDecl *Found = *Result.begin();
  S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
  S.Diag(Found->getLocation(), diag::note_declared_at);
  return true;
}

// Build the template-id.
QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
if (TraitTy.isNull())
  return true;
if (!S.isCompleteType(Loc, TraitTy)) {
  if (DiagID)
    S.RequireCompleteType(
        Loc, TraitTy, DiagID,
        printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                          TraitTD->getTemplateParameters()));
  return true;
}

CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
assert(RD && "specialization of class template is not a class?")((void)0);

// Look up the member of the trait type.
S.LookupQualifiedName(TraitMemberLookup, RD);
return TraitMemberLookup.isAmbiguous();
1051}

1053static TemplateArgumentLoc
1054getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
                                 uint64_t I) {
TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1058}

1060static TemplateArgumentLoc
1061getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1063}

1065namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }

1067static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
                             llvm::APSInt &Size) {
EnterExpressionEvaluationContext ContextRAII(
    S, Sema::ExpressionEvaluationContext::ConstantEvaluated);

DeclarationName Value = S.PP.getIdentifierInfo("value");
LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);

// Form template argument list for tuple_size<T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));

// If there's no tuple_size specialization or the lookup of 'value' is empty,
// it's not tuple-like.
if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
    R.empty())
  return IsTupleLike::NotTupleLike;

// If we get this far, we've committed to the tuple interpretation, but
// we can still fail if there actually isn't a usable ::value.

struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
  LookupResult &R;
  TemplateArgumentListInfo &Args;
  ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
      : R(R), Args(Args) {}
  Sema::SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
                                             SourceLocation Loc) override {
    return S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
           << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                                /*Params*/ nullptr);
  }
} Diagnoser(R, Args);

ExprResult E =
    S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
if (E.isInvalid())
  return IsTupleLike::Error;

E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser);
if (E.isInvalid())
  return IsTupleLike::Error;

return IsTupleLike::TupleLike;
1111}

1113/// \return std::tuple_element<I, T>::type.
1114static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
                                      unsigned I, QualType T) {
// Form template argument list for tuple_element<I, T>.
TemplateArgumentListInfo Args(Loc, Loc);
Args.addArgument(
    getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));

DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
if (lookupStdTypeTraitMember(
        S, R, Loc, "tuple_element", Args,
        diag::err_decomp_decl_std_tuple_element_not_specialized))
  return QualType();

auto *TD = R.getAsSingle<TypeDecl>();
if (!TD) {
  R.suppressDiagnostics();
  S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
      << printTemplateArgs(S.Context.getPrintingPolicy(), Args,
                           /*Params*/ nullptr);
  if (!R.empty())
    S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
  return QualType();
}

return S.Context.getTypeDeclType(TD);
1141}

1143namespace {
1144struct InitializingBinding {
Sema &S;
InitializingBinding(Sema &S, BindingDecl *BD) : S(S) {
  Sema::CodeSynthesisContext Ctx;
  Ctx.Kind = Sema::CodeSynthesisContext::InitializingStructuredBinding;
  Ctx.PointOfInstantiation = BD->getLocation();
  Ctx.Entity = BD;
  S.pushCodeSynthesisContext(Ctx);
}
~InitializingBinding() {
  S.popCodeSynthesisContext();
}
1156};
1157}

1159static bool checkTupleLikeDecomposition(Sema &S,
                                      ArrayRef<BindingDecl *> Bindings,
                                      VarDecl *Src, QualType DecompType,
                                      const llvm::APSInt &TupleSize) {
if ((int64_t)Bindings.size() != TupleSize) {
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size()
      << (unsigned)TupleSize.getLimitedValue(UINT_MAX(2147483647 *2U +1U))
      << toString(TupleSize, 10) << (TupleSize < Bindings.size());
  return true;
}

if (Bindings.empty())
  return false;

DeclarationName GetDN = S.PP.getIdentifierInfo("get");

// [dcl.decomp]p3:
//   The unqualified-id get is looked up in the scope of E by class member
//   access lookup ...
LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
bool UseMemberGet = false;
if (S.isCompleteType(Src->getLocation(), DecompType)) {
  if (auto *RD = DecompType->getAsCXXRecordDecl())
    S.LookupQualifiedName(MemberGet, RD);
  if (MemberGet.isAmbiguous())
    return true;
  //   ... and if that finds at least one declaration that is a function
  //   template whose first template parameter is a non-type parameter ...
  for (NamedDecl *D : MemberGet) {
    if (FunctionTemplateDecl *FTD =
            dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
      TemplateParameterList *TPL = FTD->getTemplateParameters();
      if (TPL->size() != 0 &&
          isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
        //   ... the initializer is e.get<i>().
        UseMemberGet = true;
        break;
      }
    }
  }
}

unsigned I = 0;
for (auto *B : Bindings) {
  InitializingBinding InitContext(S, B);
  SourceLocation Loc = B->getLocation();

  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;

  //   e is an lvalue if the type of the entity is an lvalue reference and
  //   an xvalue otherwise
  if (!Src->getType()->isLValueReferenceType())
    E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
                                 E.get(), nullptr, VK_XValue,
                                 FPOptionsOverride());

  TemplateArgumentListInfo Args(Loc, Loc);
  Args.addArgument(
      getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));

  if (UseMemberGet) {
    //   if [lookup of member get] finds at least one declaration, the
    //   initializer is e.get<i-1>().
    E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
                                   CXXScopeSpec(), SourceLocation(), nullptr,
                                   MemberGet, &Args, nullptr);
    if (E.isInvalid())
      return true;

    E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
  } else {
    //   Otherwise, the initializer is get<i-1>(e), where get is looked up
    //   in the associated namespaces.
    Expr *Get = UnresolvedLookupExpr::Create(
        S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
        DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
        UnresolvedSetIterator(), UnresolvedSetIterator());

    Expr *Arg = E.get();
    E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
  }
  if (E.isInvalid())
    return true;
  Expr *Init = E.get();

  //   Given the type T designated by std::tuple_element<i - 1, E>::type,
  QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
  if (T.isNull())
    return true;

  //   each vi is a variable of type "reference to T" initialized with the
  //   initializer, where the reference is an lvalue reference if the
  //   initializer is an lvalue and an rvalue reference otherwise
  QualType RefType =
      S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
  if (RefType.isNull())
    return true;
  auto *RefVD = VarDecl::Create(
      S.Context, Src->getDeclContext(), Loc, Loc,
      B->getDeclName().getAsIdentifierInfo(), RefType,
      S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
  RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
  RefVD->setTSCSpec(Src->getTSCSpec());
  RefVD->setImplicit();
  if (Src->isInlineSpecified())
    RefVD->setInlineSpecified();
  RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);

  InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
  InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
  InitializationSequence Seq(S, Entity, Kind, Init);
  E = Seq.Perform(S, Entity, Kind, Init);
  if (E.isInvalid())
    return true;
  E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
  if (E.isInvalid())
    return true;
  RefVD->setInit(E.get());
  S.CheckCompleteVariableDeclaration(RefVD);

  E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
                                 DeclarationNameInfo(B->getDeclName(), Loc),
                                 RefVD);
  if (E.isInvalid())
    return true;

  B->setBinding(T, E.get());
  I++;
}

return false;
1293}

1295/// Find the base class to decompose in a built-in decomposition of a class type.
1296/// This base class search is, unfortunately, not quite like any other that we
1297/// perform anywhere else in C++.
1298static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
                                              const CXXRecordDecl *RD,
                                              CXXCastPath &BasePath) {
auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
                        CXXBasePath &Path) {
  return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
};

const CXXRecordDecl *ClassWithFields = nullptr;
AccessSpecifier AS = AS_public;
if (RD->hasDirectFields())
  // [dcl.decomp]p4:
  //   Otherwise, all of E's non-static data members shall be public direct
  //   members of E ...
  ClassWithFields = RD;
else {
  //   ... or of ...
  CXXBasePaths Paths;
  Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
  if (!RD->lookupInBases(BaseHasFields, Paths)) {
    // If no classes have fields, just decompose RD itself. (This will work
    // if and only if zero bindings were provided.)
    return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
  }

  CXXBasePath *BestPath = nullptr;
  for (auto &P : Paths) {
    if (!BestPath)
      BestPath = &P;
    else if (!S.Context.hasSameType(P.back().Base->getType(),
                                    BestPath->back().Base->getType())) {
      //   ... the same ...
      S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
        << false << RD << BestPath->back().Base->getType()
        << P.back().Base->getType();
      return DeclAccessPair();
    } else if (P.Access < BestPath->Access) {
      BestPath = &P;
    }
  }

  //   ... unambiguous ...
  QualType BaseType = BestPath->back().Base->getType();
  if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
    S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
      << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
    return DeclAccessPair();
  }

  //   ... [accessible, implied by other rules] base class of E.
  S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
                         *BestPath, diag::err_decomp_decl_inaccessible_base);
  AS = BestPath->Access;

  ClassWithFields = BaseType->getAsCXXRecordDecl();
  S.BuildBasePathArray(Paths, BasePath);
}

// The above search did not check whether the selected class itself has base
// classes with fields, so check that now.
CXXBasePaths Paths;
if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
  S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
    << (ClassWithFields == RD) << RD << ClassWithFields
    << Paths.front().back().Base->getType();
  return DeclAccessPair();
}

return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1367}

1369static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
                                   ValueDecl *Src, QualType DecompType,
                                   const CXXRecordDecl *OrigRD) {
if (S.RequireCompleteType(Src->getLocation(), DecompType,
                          diag::err_incomplete_type))
  return true;

CXXCastPath BasePath;
DeclAccessPair BasePair =
    findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
if (!RD)
  return true;
QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
                                               DecompType.getQualifiers());

auto DiagnoseBadNumberOfBindings = [&]() -> bool {
  unsigned NumFields =
      std::count_if(RD->field_begin(), RD->field_end(),
                    [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
  assert(Bindings.size() != NumFields)((void)0);
  S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
      << DecompType << (unsigned)Bindings.size() << NumFields << NumFields
      << (NumFields < Bindings.size());
  return true;
};

//   all of E's non-static data members shall be [...] well-formed
//   when named as e.name in the context of the structured binding,
//   E shall not have an anonymous union member, ...
unsigned I = 0;
for (auto *FD : RD->fields()) {
  if (FD->isUnnamedBitfield())
    continue;

  // All the non-static data members are required to be nameable, so they
  // must all have names.
  if (!FD->getDeclName()) {
    if (RD->isLambda()) {
      S.Diag(Src->getLocation(), diag::err_decomp_decl_lambda);
      S.Diag(RD->getLocation(), diag::note_lambda_decl);
      return true;
    }

    if (FD->isAnonymousStructOrUnion()) {
      S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
        << DecompType << FD->getType()->isUnionType();
      S.Diag(FD->getLocation(), diag::note_declared_at);
      return true;
    }

    // FIXME: Are there any other ways we could have an anonymous member?
  }

  // We have a real field to bind.
  if (I >= Bindings.size())
    return DiagnoseBadNumberOfBindings();
  auto *B = Bindings[I++];
  SourceLocation Loc = B->getLocation();

  // The field must be accessible in the context of the structured binding.
  // We already checked that the base class is accessible.
  // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
  // const_cast here.
  S.CheckStructuredBindingMemberAccess(
      Loc, const_cast<CXXRecordDecl *>(OrigRD),
      DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
                                   BasePair.getAccess(), FD->getAccess())));

  // Initialize the binding to Src.FD.
  ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
  if (E.isInvalid())
    return true;
  E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
                          VK_LValue, &BasePath);
  if (E.isInvalid())
    return true;
  E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
                                CXXScopeSpec(), FD,
                                DeclAccessPair::make(FD, FD->getAccess()),
                                DeclarationNameInfo(FD->getDeclName(), Loc));
  if (E.isInvalid())
    return true;

  // If the type of the member is T, the referenced type is cv T, where cv is
  // the cv-qualification of the decomposition expression.
  //
  // FIXME: We resolve a defect here: if the field is mutable, we do not add
  // 'const' to the type of the field.
  Qualifiers Q = DecompType.getQualifiers();
  if (FD->isMutable())
    Q.removeConst();
  B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
}

if (I != Bindings.size())
  return DiagnoseBadNumberOfBindings();

return false;
1468}

1470void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
QualType DecompType = DD->getType();

// If the type of the decomposition is dependent, then so is the type of
// each binding.
if (DecompType->isDependentType()) {
  for (auto *B : DD->bindings())
    B->setType(Context.DependentTy);
  return;
}

DecompType = DecompType.getNonReferenceType();
ArrayRef<BindingDecl*> Bindings = DD->bindings();

// C++1z [dcl.decomp]/2:
//   If E is an array type [...]
// As an extension, we also support decomposition of built-in complex and
// vector types.
if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
  if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
    DD->setInvalidDecl();
  return;
}
if (auto *VT = DecompType->getAs<VectorType>()) {
  if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
    DD->setInvalidDecl();
  return;
}
if (auto *CT = DecompType->getAs<ComplexType>()) {
  if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
    DD->setInvalidDecl();
  return;
}

// C++1z [dcl.decomp]/3:
//   if the expression std::tuple_size<E>::value is a well-formed integral
//   constant expression, [...]
llvm::APSInt TupleSize(32);
switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
case IsTupleLike::Error:
  DD->setInvalidDecl();
  return;

case IsTupleLike::TupleLike:
  if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
    DD->setInvalidDecl();
  return;

case IsTupleLike::NotTupleLike:
  break;
}

// C++1z [dcl.dcl]/8:
//   [E shall be of array or non-union class type]
CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
if (!RD || RD->isUnion()) {
  Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
      << DD << !RD << DecompType;
  DD->setInvalidDecl();
  return;
}

// C++1z [dcl.decomp]/4:
//   all of E's non-static data members shall be [...] direct members of
//   E or of the same unambiguous public base class of E, ...
if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
  DD->setInvalidDecl();
1537}

1539/// Merge the exception specifications of two variable declarations.
1540///
1541/// This is called when there's a redeclaration of a VarDecl. The function
1542/// checks if the redeclaration might have an exception specification and
1543/// validates compatibility and merges the specs if necessary.
1544void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
// Shortcut if exceptions are disabled.
if (!getLangOpts().CXXExceptions)
  return;

assert(Context.hasSameType(New->getType(), Old->getType()) &&((void)0)
       "Should only be called if types are otherwise the same.")((void)0);

QualType NewType = New->getType();
QualType OldType = Old->getType();

// We're only interested in pointers and references to functions, as well
// as pointers to member functions.
if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
  NewType = R->getPointeeType();
  OldType = OldType->castAs<ReferenceType>()->getPointeeType();
} else if (const PointerType *P = NewType->getAs<PointerType>()) {
  NewType = P->getPointeeType();
  OldType = OldType->castAs<PointerType>()->getPointeeType();
} else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
  NewType = M->getPointeeType();
  OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
}

if (!NewType->isFunctionProtoType())
  return;

// There's lots of special cases for functions. For function pointers, system
// libraries are hopefully not as broken so that we don't need these
// workarounds.
if (CheckEquivalentExceptionSpec(
      OldType->getAs<FunctionProtoType>(), Old->getLocation(),
      NewType->getAs<FunctionProtoType>(), New->getLocation())) {
  New->setInvalidDecl();
}
1579}

1581/// CheckCXXDefaultArguments - Verify that the default arguments for a
1582/// function declaration are well-formed according to C++
1583/// [dcl.fct.default].
1584void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
unsigned NumParams = FD->getNumParams();
unsigned ParamIdx = 0;

// This checking doesn't make sense for explicit specializations; their
// default arguments are determined by the declaration we're specializing,
// not by FD.
if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
  return;
if (auto *FTD = FD->getDescribedFunctionTemplate())
  if (FTD->isMemberSpecialization())
    return;

// Find first parameter with a default argument
for (; ParamIdx < NumParams; ++ParamIdx) {
  ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
  if (Param->hasDefaultArg())
    break;
}

// C++20 [dcl.fct.default]p4:
//   In a given function declaration, each parameter subsequent to a parameter
//   with a default argument shall have a default argument supplied in this or
//   a previous declaration, unless the parameter was expanded from a
//   parameter pack, or shall be a function parameter pack.
for (; ParamIdx < NumParams; ++ParamIdx) {
  ParmVarDecl *Param = FD->getParamDecl(ParamIdx);
  if (!Param->hasDefaultArg() && !Param->isParameterPack() &&
      !(CurrentInstantiationScope &&
        CurrentInstantiationScope->isLocalPackExpansion(Param))) {
    if (Param->isInvalidDecl())
      /* We already complained about this parameter. */;
    else if (Param->getIdentifier())
      Diag(Param->getLocation(),
           diag::err_param_default_argument_missing_name)
        << Param->getIdentifier();
    else
      Diag(Param->getLocation(),
           diag::err_param_default_argument_missing);
  }
}
1625}

1627/// Check that the given type is a literal type. Issue a diagnostic if not,
1628/// if Kind is Diagnose.
1629/// \return \c true if a problem has been found (and optionally diagnosed).
1630template <typename... Ts>
1631static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
                           SourceLocation Loc, QualType T, unsigned DiagID,
                           Ts &&...DiagArgs) {
if (T->isDependentType())
  return false;

switch (Kind) {
case Sema::CheckConstexprKind::Diagnose:
  return SemaRef.RequireLiteralType(Loc, T, DiagID,
                                    std::forward<Ts>(DiagArgs)...);

case Sema::CheckConstexprKind::CheckValid:
  return !T->isLiteralType(SemaRef.Context);
}

llvm_unreachable("unknown CheckConstexprKind")__builtin_unreachable();
1647}

1649/// Determine whether a destructor cannot be constexpr due to
1650static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
                                             const CXXDestructorDecl *DD,
                                             Sema::CheckConstexprKind Kind) {
auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
  const CXXRecordDecl *RD =
      T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
  if (!RD || RD->hasConstexprDestructor())
    return true;

  if (Kind == Sema::CheckConstexprKind::Diagnose) {
    SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
        << static_cast<int>(DD->getConstexprKind()) << !FD
        << (FD ? FD->getDeclName() : DeclarationName()) << T;
    SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
        << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
  }
  return false;
};

const CXXRecordDecl *RD = DD->getParent();
for (const CXXBaseSpecifier &B : RD->bases())
  if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
    return false;
for (const FieldDecl *FD : RD->fields())
  if (!Check(FD->getLocation(), FD->getType(), FD))
    return false;
return true;
1677}

1679/// Check whether a function's parameter types are all literal types. If so,
1680/// return true. If not, produce a suitable diagnostic and return false.
1681static bool CheckConstexprParameterTypes(Sema &SemaRef,
                                       const FunctionDecl *FD,
                                       Sema::CheckConstexprKind Kind) {
unsigned ArgIndex = 0;
const auto *FT = FD->getType()->castAs<FunctionProtoType>();
for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
                                            e = FT->param_type_end();
     i != e; ++i, ++ArgIndex) {
  const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
  SourceLocation ParamLoc = PD->getLocation();
  if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
                       diag::err_constexpr_non_literal_param, ArgIndex + 1,
                       PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
                       FD->isConsteval()))
    return false;
}
return true;
1698}

1700/// Check whether a function's return type is a literal type. If so, return
1701/// true. If not, produce a suitable diagnostic and return false.
1702static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
                                   Sema::CheckConstexprKind Kind) {
if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
                     diag::err_constexpr_non_literal_return,
                     FD->isConsteval()))
  return false;
return true;
1709}

1711/// Get diagnostic %select index for tag kind for
1712/// record diagnostic message.
1713/// WARNING: Indexes apply to particular diagnostics only!
1714///
1715/// \returns diagnostic %select index.
1716static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
switch (Tag) {
case TTK_Struct: return 0;
case TTK_Interface: return 1;
case TTK_Class:  return 2;
default: llvm_unreachable("Invalid tag kind for record diagnostic!")__builtin_unreachable();
}
1723}

1725static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
                                     Stmt *Body,
                                     Sema::CheckConstexprKind Kind);

1729// Check whether a function declaration satisfies the requirements of a
1730// constexpr function definition or a constexpr constructor definition. If so,
1731// return true. If not, produce appropriate diagnostics (unless asked not to by
1732// Kind) and return false.
1733//
1734// This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1735bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
                                          CheckConstexprKind Kind) {
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
if (MD && MD->isInstance()) {
  // C++11 [dcl.constexpr]p4:
  //  The definition of a constexpr constructor shall satisfy the following
  //  constraints:
  //  - the class shall not have any virtual base classes;
  //
  // FIXME: This only applies to constructors and destructors, not arbitrary
  // member functions.
  const CXXRecordDecl *RD = MD->getParent();
  if (RD->getNumVBases()) {
    if (Kind == CheckConstexprKind::CheckValid)
      return false;

    Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
      << isa<CXXConstructorDecl>(NewFD)
      << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
    for (const auto &I : RD->vbases())
      Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
          << I.getSourceRange();
    return false;
  }
}

if (!isa<CXXConstructorDecl>(NewFD)) {
  // C++11 [dcl.constexpr]p3:
  //  The definition of a constexpr function shall satisfy the following
  //  constraints:
  // - it shall not be virtual; (removed in C++20)
  const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
  if (Method && Method->isVirtual()) {
    if (getLangOpts().CPlusPlus20) {
      if (Kind == CheckConstexprKind::Diagnose)
        Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
    } else {
      if (Kind == CheckConstexprKind::CheckValid)
        return false;

      Method = Method->getCanonicalDecl();
      Diag(Method->getLocation(), diag::err_constexpr_virtual);

      // If it's not obvious why this function is virtual, find an overridden
      // function which uses the 'virtual' keyword.
      const CXXMethodDecl *WrittenVirtual = Method;
      while (!WrittenVirtual->isVirtualAsWritten())
        WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
      if (WrittenVirtual != Method)
        Diag(WrittenVirtual->getLocation(),
             diag::note_overridden_virtual_function);
      return false;
    }
  }

  // - its return type shall be a literal type;
  if (!CheckConstexprReturnType(*this, NewFD, Kind))
    return false;
}

if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
  // A destructor can be constexpr only if the defaulted destructor could be;
  // we don't need to check the members and bases if we already know they all
  // have constexpr destructors.
  if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
    if (Kind == CheckConstexprKind::CheckValid)
      return false;
    if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
      return false;
  }
}

// - each of its parameter types shall be a literal type;
if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
  return false;

Stmt *Body = NewFD->getBody();
assert(Body &&((void)0)
       "CheckConstexprFunctionDefinition called on function with no body")((void)0);
return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1815}

1817/// Check the given declaration statement is legal within a constexpr function
1818/// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1819///
1820/// \return true if the body is OK (maybe only as an extension), false if we
1821///         have diagnosed a problem.
1822static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
                                 DeclStmt *DS, SourceLocation &Cxx1yLoc,
                                 Sema::CheckConstexprKind Kind) {
// C++11 [dcl.constexpr]p3 and p4:
//  The definition of a constexpr function(p3) or constructor(p4) [...] shall
//  contain only
for (const auto *DclIt : DS->decls()) {
  switch (DclIt->getKind()) {
  case Decl::StaticAssert:
  case Decl::Using:
  case Decl::UsingShadow:
  case Decl::UsingDirective:
  case Decl::UnresolvedUsingTypename:
  case Decl::UnresolvedUsingValue:
  case Decl::UsingEnum:
    //   - static_assert-declarations
    //   - using-declarations,
    //   - using-directives,
    //   - using-enum-declaration
    continue;

  case Decl::Typedef:
  case Decl::TypeAlias: {
    //   - typedef declarations and alias-declarations that do not define
    //     classes or enumerations,
    const auto *TN = cast<TypedefNameDecl>(DclIt);
    if (TN->getUnderlyingType()->isVariablyModifiedType()) {
      // Don't allow variably-modified types in constexpr functions.
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
        SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
          << TL.getSourceRange() << TL.getType()
          << isa<CXXConstructorDecl>(Dcl);
      }
      return false;
    }
    continue;
  }

  case Decl::Enum:
  case Decl::CXXRecord:
    // C++1y allows types to be defined, not just declared.
    if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        SemaRef.Diag(DS->getBeginLoc(),
                     SemaRef.getLangOpts().CPlusPlus14
                         ? diag::warn_cxx11_compat_constexpr_type_definition
                         : diag::ext_constexpr_type_definition)
            << isa<CXXConstructorDecl>(Dcl);
      } else if (!SemaRef.getLangOpts().CPlusPlus14) {
        return false;
      }
    }
    continue;

  case Decl::EnumConstant:
  case Decl::IndirectField:
  case Decl::ParmVar:
    // These can only appear with other declarations which are banned in
    // C++11 and permitted in C++1y, so ignore them.
    continue;

  case Decl::Var:
  case Decl::Decomposition: {
    // C++1y [dcl.constexpr]p3 allows anything except:
    //   a definition of a variable of non-literal type or of static or
    //   thread storage duration or [before C++2a] for which no
    //   initialization is performed.
    const auto *VD = cast<VarDecl>(DclIt);
    if (VD->isThisDeclarationADefinition()) {
      if (VD->isStaticLocal()) {
        if (Kind == Sema::CheckConstexprKind::Diagnose) {
          SemaRef.Diag(VD->getLocation(),
                       diag::err_constexpr_local_var_static)
            << isa<CXXConstructorDecl>(Dcl)
            << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
        }
        return false;
      }
      if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
                           diag::err_constexpr_local_var_non_literal_type,
                           isa<CXXConstructorDecl>(Dcl)))
        return false;
      if (!VD->getType()->isDependentType() &&
          !VD->hasInit() && !VD->isCXXForRangeDecl()) {
        if (Kind == Sema::CheckConstexprKind::Diagnose) {
          SemaRef.Diag(
              VD->getLocation(),
              SemaRef.getLangOpts().CPlusPlus20
                  ? diag::warn_cxx17_compat_constexpr_local_var_no_init
                  : diag::ext_constexpr_local_var_no_init)
              << isa<CXXConstructorDecl>(Dcl);
        } else if (!SemaRef.getLangOpts().CPlusPlus20) {
          return false;
        }
        continue;
      }
    }
    if (Kind == Sema::CheckConstexprKind::Diagnose) {
      SemaRef.Diag(VD->getLocation(),
                   SemaRef.getLangOpts().CPlusPlus14
                    ? diag::warn_cxx11_compat_constexpr_local_var
                    : diag::ext_constexpr_local_var)
        << isa<CXXConstructorDecl>(Dcl);
    } else if (!SemaRef.getLangOpts().CPlusPlus14) {
      return false;
    }
    continue;
  }

  case Decl::NamespaceAlias:
  case Decl::Function:
    // These are disallowed in C++11 and permitted in C++1y. Allow them
    // everywhere as an extension.
    if (!Cxx1yLoc.isValid())
      Cxx1yLoc = DS->getBeginLoc();
    continue;

  default:
    if (Kind == Sema::CheckConstexprKind::Diagnose) {
      SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
          << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
    }
    return false;
  }
}

return true;
1950}

1952/// Check that the given field is initialized within a constexpr constructor.
1953///
1954/// \param Dcl The constexpr constructor being checked.
1955/// \param Field The field being checked. This may be a member of an anonymous
1956///        struct or union nested within the class being checked.
1957/// \param Inits All declarations, including anonymous struct/union members and
1958///        indirect members, for which any initialization was provided.
1959/// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1960///        multiple notes for different members to the same error.
1961/// \param Kind Whether we're diagnosing a constructor as written or determining
1962///        whether the formal requirements are satisfied.
1963/// \return \c false if we're checking for validity and the constructor does
1964///         not satisfy the requirements on a constexpr constructor.
1965static bool CheckConstexprCtorInitializer(Sema &SemaRef,
                                        const FunctionDecl *Dcl,
                                        FieldDecl *Field,
                                        llvm::SmallSet<Decl*, 16> &Inits,
                                        bool &Diagnosed,
                                        Sema::CheckConstexprKind Kind) {
// In C++20 onwards, there's nothing to check for validity.
if (Kind == Sema::CheckConstexprKind::CheckValid &&
    SemaRef.getLangOpts().CPlusPlus20)
  return true;

if (Field->isInvalidDecl())
  return true;

if (Field->isUnnamedBitfield())
  return true;

// Anonymous unions with no variant members and empty anonymous structs do not
// need to be explicitly initialized. FIXME: Anonymous structs that contain no
// indirect fields don't need initializing.
if (Field->isAnonymousStructOrUnion() &&
    (Field->getType()->isUnionType()
         ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
         : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
  return true;

if (!Inits.count(Field)) {
  if (Kind == Sema::CheckConstexprKind::Diagnose) {
    if (!Diagnosed) {
      SemaRef.Diag(Dcl->getLocation(),
                   SemaRef.getLangOpts().CPlusPlus20
                       ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
                       : diag::ext_constexpr_ctor_missing_init);
      Diagnosed = true;
    }
    SemaRef.Diag(Field->getLocation(),
                 diag::note_constexpr_ctor_missing_init);
  } else if (!SemaRef.getLangOpts().CPlusPlus20) {
    return false;
  }
} else if (Field->isAnonymousStructOrUnion()) {
  const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
  for (auto *I : RD->fields())
    // If an anonymous union contains an anonymous struct of which any member
    // is initialized, all members must be initialized.
    if (!RD->isUnion() || Inits.count(I))
      if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
                                         Kind))
        return false;
}
return true;
2016}

2018/// Check the provided statement is allowed in a constexpr function
2019/// definition.
2020static bool
2021CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
                         SmallVectorImpl<SourceLocation> &ReturnStmts,
                         SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
                         Sema::CheckConstexprKind Kind) {
// - its function-body shall be [...] a compound-statement that contains only
switch (S->getStmtClass()) {
case Stmt::NullStmtClass:
  //   - null statements,
  return true;

case Stmt::DeclStmtClass:
  //   - static_assert-declarations
  //   - using-declarations,
  //   - using-directives,
  //   - typedef declarations and alias-declarations that do not define
  //     classes or enumerations,
  if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
    return false;
  return true;

case Stmt::ReturnStmtClass:
  //   - and exactly one return statement;
  if (isa<CXXConstructorDecl>(Dcl)) {
    // C++1y allows return statements in constexpr constructors.
    if (!Cxx1yLoc.isValid())
      Cxx1yLoc = S->getBeginLoc();
    return true;
  }

  ReturnStmts.push_back(S->getBeginLoc());
  return true;

case Stmt::CompoundStmtClass: {
  // C++1y allows compound-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();

  CompoundStmt *CompStmt = cast<CompoundStmt>(S);
  for (auto *BodyIt : CompStmt->body()) {
    if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  }
  return true;
}

case Stmt::AttributedStmtClass:
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  return true;

case Stmt::IfStmtClass: {
  // C++1y allows if-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();

  IfStmt *If = cast<IfStmt>(S);
  if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  if (If->getElse() &&
      !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  return true;
}

case Stmt::WhileStmtClass:
case Stmt::DoStmtClass:
case Stmt::ForStmtClass:
case Stmt::CXXForRangeStmtClass:
case Stmt::ContinueStmtClass:
  // C++1y allows all of these. We don't allow them as extensions in C++11,
  // because they don't make sense without variable mutation.
  if (!SemaRef.getLangOpts().CPlusPlus14)
    break;
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children())
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  return true;

case Stmt::SwitchStmtClass:
case Stmt::CaseStmtClass:
case Stmt::DefaultStmtClass:
case Stmt::BreakStmtClass:
  // C++1y allows switch-statements, and since they don't need variable
  // mutation, we can reasonably allow them in C++11 as an extension.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children())
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  return true;

case Stmt::GCCAsmStmtClass:
case Stmt::MSAsmStmtClass:
  // C++2a allows inline assembly statements.
case Stmt::CXXTryStmtClass:
  if (Cxx2aLoc.isInvalid())
    Cxx2aLoc = S->getBeginLoc();
  for (Stmt *SubStmt : S->children()) {
    if (SubStmt &&
        !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                    Cxx1yLoc, Cxx2aLoc, Kind))
      return false;
  }
  return true;

case Stmt::CXXCatchStmtClass:
  // Do not bother checking the language mode (already covered by the
  // try block check).
  if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
                                  cast<CXXCatchStmt>(S)->getHandlerBlock(),
                                  ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
  return true;

default:
  if (!isa<Expr>(S))
    break;

  // C++1y allows expression-statements.
  if (!Cxx1yLoc.isValid())
    Cxx1yLoc = S->getBeginLoc();
  return true;
}

if (Kind == Sema::CheckConstexprKind::Diagnose) {
  SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
      << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
}
return false;
2159}

2161/// Check the body for the given constexpr function declaration only contains
2162/// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2163///
2164/// \return true if the body is OK, false if we have found or diagnosed a
2165/// problem.
2166static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
                                     Stmt *Body,
                                     Sema::CheckConstexprKind Kind) {
SmallVector<SourceLocation, 4> ReturnStmts;

if (isa<CXXTryStmt>(Body)) {
  // C++11 [dcl.constexpr]p3:
  //  The definition of a constexpr function shall satisfy the following
  //  constraints: [...]
  // - its function-body shall be = delete, = default, or a
  //   compound-statement
  //
  // C++11 [dcl.constexpr]p4:
  //  In the definition of a constexpr constructor, [...]
  // - its function-body shall not be a function-try-block;
  //
  // This restriction is lifted in C++2a, as long as inner statements also
  // apply the general constexpr rules.
  switch (Kind) {
  case Sema::CheckConstexprKind::CheckValid:
    if (!SemaRef.getLangOpts().CPlusPlus20)
      return false;
    break;

  case Sema::CheckConstexprKind::Diagnose:
    SemaRef.Diag(Body->getBeginLoc(),
         !SemaRef.getLangOpts().CPlusPlus20
             ? diag::ext_constexpr_function_try_block_cxx20
             : diag::warn_cxx17_compat_constexpr_function_try_block)
        << isa<CXXConstructorDecl>(Dcl);
    break;
  }
}

// - its function-body shall be [...] a compound-statement that contains only
//   [... list of cases ...]
//
// Note that walking the children here is enough to properly check for
// CompoundStmt and CXXTryStmt body.
SourceLocation Cxx1yLoc, Cxx2aLoc;
for (Stmt *SubStmt : Body->children()) {
  if (SubStmt &&
      !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
                                  Cxx1yLoc, Cxx2aLoc, Kind))
    return false;
}

if (Kind == Sema::CheckConstexprKind::CheckValid) {
  // If this is only valid as an extension, report that we don't satisfy the
  // constraints of the current language.
  if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus20) ||
      (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
    return false;
} else if (Cxx2aLoc.isValid()) {
  SemaRef.Diag(Cxx2aLoc,
       SemaRef.getLangOpts().CPlusPlus20
         ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
         : diag::ext_constexpr_body_invalid_stmt_cxx20)
    << isa<CXXConstructorDecl>(Dcl);
} else if (Cxx1yLoc.isValid()) {
  SemaRef.Diag(Cxx1yLoc,
       SemaRef.getLangOpts().CPlusPlus14
         ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
         : diag::ext_constexpr_body_invalid_stmt)
    << isa<CXXConstructorDecl>(Dcl);
}

if (const CXXConstructorDecl *Constructor
      = dyn_cast<CXXConstructorDecl>(Dcl)) {
  const CXXRecordDecl *RD = Constructor->getParent();
  // DR1359:
  // - every non-variant non-static data member and base class sub-object
  //   shall be initialized;
  // DR1460:
  // - if the class is a union having variant members, exactly one of them
  //   shall be initialized;
  if (RD->isUnion()) {
    if (Constructor->getNumCtorInitializers() == 0 &&
        RD->hasVariantMembers()) {
      if (Kind == Sema::CheckConstexprKind::Diagnose) {
        SemaRef.Diag(
            Dcl->getLocation(),
            SemaRef.getLangOpts().CPlusPlus20
                ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
                : diag::ext_constexpr_union_ctor_no_init);
      } else if (!SemaRef.getLangOpts().CPlusPlus20) {
        return false;
      }
    }
  } else if (!Constructor->isDependentContext() &&
             !Constructor->isDelegatingConstructor()) {
    assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases")((void)0);

    // Skip detailed checking if we have enough initializers, and we would
    // allow at most one initializer per member.
    bool AnyAnonStructUnionMembers = false;
    unsigned Fields = 0;
    for (CXXRecordDecl::field_iterator I = RD->field_begin(),
         E = RD->field_end(); I != E; ++I, ++Fields) {
      if (I->isAnonymousStructOrUnion()) {
        AnyAnonStructUnionMembers = true;
        break;
      }
    }
    // DR1460:
    // - if the class is a union-like class, but is not a union, for each of
    //   its anonymous union members having variant members, exactly one of
    //   them shall be initialized;
    if (AnyAnonStructUnionMembers ||
        Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
      // Check initialization of non-static data members. Base classes are
      // always initialized so do not need to be checked. Dependent bases
      // might not have initializers in the member initializer list.
      llvm::SmallSet<Decl*, 16> Inits;
      for (const auto *I: Constructor->inits()) {
        if (FieldDecl *FD = I->getMember())
          Inits.insert(FD);
        else if (IndirectFieldDecl *ID = I->getIndirectMember())
          Inits.insert(ID->chain_begin(), ID->chain_end());
      }

      bool Diagnosed = false;
      for (auto *I : RD->fields())
        if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
                                           Kind))
          return false;
    }
  }
} else {
  if (ReturnStmts.empty()) {
    // C++1y doesn't require constexpr functions to contain a 'return'
    // statement. We still do, unless the return type might be void, because
    // otherwise if there's no return statement, the function cannot
    // be used in a core constant expression.
    bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
              (Dcl->getReturnType()->isVoidType() ||
               Dcl->getReturnType()->isDependentType());
    switch (Kind) {
    case Sema::CheckConstexprKind::Diagnose:
      SemaRef.Diag(Dcl->getLocation(),
                   OK ? diag::warn_cxx11_compat_constexpr_body_no_return
                      : diag::err_constexpr_body_no_return)
          << Dcl->isConsteval();
      if (!OK)
        return false;
      break;

    case Sema::CheckConstexprKind::CheckValid:
      // The formal requirements don't include this rule in C++14, even
      // though the "must be able to produce a constant expression" rules
      // still imply it in some cases.
      if (!SemaRef.getLangOpts().CPlusPlus14)
        return false;
      break;
    }
  } else if (ReturnStmts.size() > 1) {
    switch (Kind) {
    case Sema::CheckConstexprKind::Diagnose:
      SemaRef.Diag(
          ReturnStmts.back(),
          SemaRef.getLangOpts().CPlusPlus14
              ? diag::warn_cxx11_compat_constexpr_body_multiple_return
              : diag::ext_constexpr_body_multiple_return);
      for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
        SemaRef.Diag(ReturnStmts[I],
                     diag::note_constexpr_body_previous_return);
      break;

    case Sema::CheckConstexprKind::CheckValid:
      if (!SemaRef.getLangOpts().CPlusPlus14)
        return false;
      break;
    }
  }
}

// C++11 [dcl.constexpr]p5:
//   if no function argument values exist such that the function invocation
//   substitution would produce a constant expression, the program is
//   ill-formed; no diagnostic required.
// C++11 [dcl.constexpr]p3:
//   - every constructor call and implicit conversion used in initializing the
//     return value shall be one of those allowed in a constant expression.
// C++11 [dcl.constexpr]p4:
//   - every constructor involved in initializing non-static data members and
//     base class sub-objects shall be a constexpr constructor.
//
// Note that this rule is distinct from the "requirements for a constexpr
// function", so is not checked in CheckValid mode.
SmallVector<PartialDiagnosticAt, 8> Diags;
if (Kind == Sema::CheckConstexprKind::Diagnose &&
    !Expr::isPotentialConstantExpr(Dcl, Diags)) {
  SemaRef.Diag(Dcl->getLocation(),
               diag::ext_constexpr_function_never_constant_expr)
      << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
  for (size_t I = 0, N = Diags.size(); I != N; ++I)
    SemaRef.Diag(Diags[I].first, Diags[I].second);
  // Don't return false here: we allow this for compatibility in
  // system headers.
}

return true;
2368}

2370/// Get the class that is directly named by the current context. This is the
2371/// class for which an unqualified-id in this scope could name a constructor
2372/// or destructor.
2373///
2374/// If the scope specifier denotes a class, this will be that class.
2375/// If the scope specifier is empty, this will be the class whose
2376/// member-specification we are currently within. Otherwise, there
2377/// is no such class.
2378CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!")((void)0);

if (SS && SS->isInvalid())
  return nullptr;

if (SS && SS->isNotEmpty()) {
  DeclContext *DC = computeDeclContext(*SS, true);
  return dyn_cast_or_null<CXXRecordDecl>(DC);
}

return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2390}

2392/// isCurrentClassName - Determine whether the identifier II is the
2393/// name of the class type currently being defined. In the case of
2394/// nested classes, this will only return true if II is the name of
2395/// the innermost class.
2396bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
                            const CXXScopeSpec *SS) {
CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
return CurDecl && &II == CurDecl->getIdentifier();
2400}

2402/// Determine whether the identifier II is a typo for the name of
2403/// the class type currently being defined. If so, update it to the identifier
2404/// that should have been used.
2405bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
assert(getLangOpts().CPlusPlus && "No class names in C!")((void)0);

if (!getLangOpts().SpellChecking)
  return false;

CXXRecordDecl *CurDecl;
if (SS && SS->isSet() && !SS->isInvalid()) {
  DeclContext *DC = computeDeclContext(*SS, true);
  CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
} else
  CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);

if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
    3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
        < II->getLength()) {
  II = CurDecl->getIdentifier();
  return true;
}

return false;
2426}

2428/// Determine whether the given class is a base class of the given
2429/// class, including looking at dependent bases.
2430static bool findCircularInheritance(const CXXRecordDecl *Class,
                                  const CXXRecordDecl *Current) {
SmallVector<const CXXRecordDecl*, 8> Queue;

Class = Class->getCanonicalDecl();
while (true) {
  for (const auto &I : Current->bases()) {
    CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
    if (!Base)
      continue;

    Base = Base->getDefinition();
    if (!Base)
      continue;

    if (Base->getCanonicalDecl() == Class)
      return true;

    Queue.push_back(Base);
  }

  if (Queue.empty())
    return false;

  Current = Queue.pop_back_val();
}

return false;
2458}

2460/// Check the validity of a C++ base class specifier.
2461///
2462/// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2463/// and returns NULL otherwise.
2464CXXBaseSpecifier *
2465Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
                       SourceRange SpecifierRange,
                       bool Virtual, AccessSpecifier Access,
                       TypeSourceInfo *TInfo,
                       SourceLocation EllipsisLoc) {
QualType BaseType = TInfo->getType();
if (BaseType->containsErrors()) {
  // Already emitted a diagnostic when parsing the error type.
  return nullptr;
}
// C++ [class.union]p1:
//   A union shall not have base classes.
if (Class->isUnion()) {
  Diag(Class->getLocation(), diag::err_base_clause_on_union)
    << SpecifierRange;
  return nullptr;
}

if (EllipsisLoc.isValid() &&
    !TInfo->getType()->containsUnexpandedParameterPack()) {
  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
    << TInfo->getTypeLoc().getSourceRange();
  EllipsisLoc = SourceLocation();
}

SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();

if (BaseType->isDependentType()) {
  // Make sure that we don't have circular inheritance among our dependent
  // bases. For non-dependent bases, the check for completeness below handles
  // this.
  if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
    if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
        ((BaseDecl = BaseDecl->getDefinition()) &&
         findCircularInheritance(Class, BaseDecl))) {
      Diag(BaseLoc, diag::err_circular_inheritance)
        << BaseType << Context.getTypeDeclType(Class);

      if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
        Diag(BaseDecl->getLocation(), diag::note_previous_decl)
          << BaseType;

      return nullptr;
    }
  }

  // Make sure that we don't make an ill-formed AST where the type of the
  // Class is non-dependent and its attached base class specifier is an
  // dependent type, which violates invariants in many clang code paths (e.g.
  // constexpr evaluator). If this case happens (in errory-recovery mode), we
  // explicitly mark the Class decl invalid. The diagnostic was already
  // emitted.
  if (!Class->getTypeForDecl()->isDependentType())
    Class->setInvalidDecl();
  return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
                                        Class->getTagKind() == TTK_Class,
                                        Access, TInfo, EllipsisLoc);
}

// Base specifiers must be record types.
if (!BaseType->isRecordType()) {
  Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
  return nullptr;
}

// C++ [class.union]p1:
//   A union shall not be used as a base class.
if (BaseType->isUnionType()) {
  Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
  return nullptr;
}

// For the MS ABI, propagate DLL attributes to base class templates.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  if (Attr *ClassAttr = getDLLAttr(Class)) {
    if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
            BaseType->getAsCXXRecordDecl())) {
      propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
                                          BaseLoc);
    }
  }
}

// C++ [class.derived]p2:
//   The class-name in a base-specifier shall not be an incompletely
//   defined class.
if (RequireCompleteType(BaseLoc, BaseType,
                        diag::err_incomplete_base_class, SpecifierRange)) {
  Class->setInvalidDecl();
  return nullptr;
}

// If the base class is polymorphic or isn't empty, the new one is/isn't, too.
RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
assert(BaseDecl && "Record type has no declaration")((void)0);
BaseDecl = BaseDecl->getDefinition();
assert(BaseDecl && "Base type is not incomplete, but has no definition")((void)0);
CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
assert(CXXBaseDecl && "Base type is not a C++ type")((void)0);

// Microsoft docs say:
// "If a base-class has a code_seg attribute, derived classes must have the
// same attribute."
const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
if ((DerivedCSA || BaseCSA) &&
    (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
  Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
  Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
    << CXXBaseDecl;
  return nullptr;
}

// A class which contains a flexible array member is not suitable for use as a
// base class:
//   - If the layout determines that a base comes before another base,
//     the flexible array member would index into the subsequent base.
//   - If the layout determines that base comes before the derived class,
//     the flexible array member would index into the derived class.
if (CXXBaseDecl->hasFlexibleArrayMember()) {
  Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
    << CXXBaseDecl->getDeclName();
  return nullptr;
}

// C++ [class]p3:
//   If a class is marked final and it appears as a base-type-specifier in
//   base-clause, the program is ill-formed.
if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
  Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
    << CXXBaseDecl->getDeclName()
    << FA->isSpelledAsSealed();
  Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
      << CXXBaseDecl->getDeclName() << FA->getRange();
  return nullptr;
}

if (BaseDecl->isInvalidDecl())
  Class->setInvalidDecl();

// Create the base specifier.
return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
                                      Class->getTagKind() == TTK_Class,
                                      Access, TInfo, EllipsisLoc);
2609}

2611/// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2612/// one entry in the base class list of a class specifier, for
2613/// example:
2614///    class foo : public bar, virtual private baz {
2615/// 'public bar' and 'virtual private baz' are each base-specifiers.
2616BaseResult
2617Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
                       ParsedAttributes &Attributes,
                       bool Virtual, AccessSpecifier Access,
                       ParsedType basetype, SourceLocation BaseLoc,
                       SourceLocation EllipsisLoc) {
if (!classdecl)
  return true;

AdjustDeclIfTemplate(classdecl);
CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
if (!Class)
  return true;

// We haven't yet attached the base specifiers.
Class->setIsParsingBaseSpecifiers();

// We do not support any C++11 attributes on base-specifiers yet.
// Diagnose any attributes we see.
for (const ParsedAttr &AL : Attributes) {
  if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
    continue;
  Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
                        ? (unsigned)diag::warn_unknown_attribute_ignored
                        : (unsigned)diag::err_base_specifier_attribute)
      << AL << AL.getRange();
}

TypeSourceInfo *TInfo = nullptr;
GetTypeFromParser(basetype, &TInfo);

if (EllipsisLoc.isInvalid() &&
    DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
                                    UPPC_BaseType))
  return true;

if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
                                                    Virtual, Access, TInfo,
                                                    EllipsisLoc))
  return BaseSpec;
else
  Class->setInvalidDecl();

return true;
2660}

2662/// Use small set to collect indirect bases.  As this is only used
2663/// locally, there's no need to abstract the small size parameter.
2664typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;

2666/// Recursively add the bases of Type.  Don't add Type itself.
2667static void
2668NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
                const QualType &Type)
2670{
// Even though the incoming type is a base, it might not be
// a class -- it could be a template parm, for instance.
if (auto Rec = Type->getAs<RecordType>()) {
  auto Decl = Rec->getAsCXXRecordDecl();

  // Iterate over its bases.
  for (const auto &BaseSpec : Decl->bases()) {
    QualType Base = Context.getCanonicalType(BaseSpec.getType())
      .getUnqualifiedType();
    if (Set.insert(Base).second)
      // If we've not already seen it, recurse.
      NoteIndirectBases(Context, Set, Base);
  }
}
2685}

2687/// Performs the actual work of attaching the given base class
2688/// specifiers to a C++ class.
2689bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
                              MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (Bases.empty())
  return false;

// Used to keep track of which base types we have already seen, so
// that we can properly diagnose redundant direct base types. Note
// that the key is always the unqualified canonical type of the base
// class.
std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;

// Used to track indirect bases so we can see if a direct base is
// ambiguous.
IndirectBaseSet IndirectBaseTypes;

// Copy non-redundant base specifiers into permanent storage.
unsigned NumGoodBases = 0;
bool Invalid = false;
for (unsigned idx = 0; idx < Bases.size(); ++idx) {
  QualType NewBaseType
    = Context.getCanonicalType(Bases[idx]->getType());
  NewBaseType = NewBaseType.getLocalUnqualifiedType();

  CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
  if (KnownBase) {
    // C++ [class.mi]p3:
    //   A class shall not be specified as a direct base class of a
    //   derived class more than once.
    Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
        << KnownBase->getType() << Bases[idx]->getSourceRange();

    // Delete the duplicate base class specifier; we're going to
    // overwrite its pointer later.
    Context.Deallocate(Bases[idx]);

    Invalid = true;
  } else {
    // Okay, add this new base class.
    KnownBase = Bases[idx];
    Bases[NumGoodBases++] = Bases[idx];

    // Note this base's direct & indirect bases, if there could be ambiguity.
    if (Bases.size() > 1)
      NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);

    if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
      const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
      if (Class->isInterface() &&
            (!RD->isInterfaceLike() ||
             KnownBase->getAccessSpecifier() != AS_public)) {
        // The Microsoft extension __interface does not permit bases that
        // are not themselves public interfaces.
        Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
            << getRecordDiagFromTagKind(RD->getTagKind()) << RD
            << RD->getSourceRange();
        Invalid = true;
      }
      if (RD->hasAttr<WeakAttr>())
        Class->addAttr(WeakAttr::CreateImplicit(Context));
    }
  }
}

// Attach the remaining base class specifiers to the derived class.
Class->setBases(Bases.data(), NumGoodBases);

// Check that the only base classes that are duplicate are virtual.
for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
  // Check whether this direct base is inaccessible due to ambiguity.
  QualType BaseType = Bases[idx]->getType();

  // Skip all dependent types in templates being used as base specifiers.
  // Checks below assume that the base specifier is a CXXRecord.
  if (BaseType->isDependentType())
    continue;

  CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
    .getUnqualifiedType();

  if (IndirectBaseTypes.count(CanonicalBase)) {
    CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                       /*DetectVirtual=*/true);
    bool found
      = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
    assert(found)((void)0);
    (void)found;

    if (Paths.isAmbiguous(CanonicalBase))
      Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
          << BaseType << getAmbiguousPathsDisplayString(Paths)
          << Bases[idx]->getSourceRange();
    else
      assert(Bases[idx]->isVirtual())((void)0);
  }

  // Delete the base class specifier, since its data has been copied
  // into the CXXRecordDecl.
  Context.Deallocate(Bases[idx]);
}

return Invalid;
2790}

2792/// ActOnBaseSpecifiers - Attach the given base specifiers to the
2793/// class, after checking whether there are any duplicate base
2794/// classes.
2795void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
                             MutableArrayRef<CXXBaseSpecifier *> Bases) {
if (!ClassDecl || Bases.empty())
  return;

AdjustDeclIfTemplate(ClassDecl);
AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2802}

2804/// Determine whether the type \p Derived is a C++ class that is
2805/// derived from the type \p Base.
2806bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
if (!getLangOpts().CPlusPlus)
  return false;

CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
  return false;

CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
  return false;

// If either the base or the derived type is invalid, don't try to
// check whether one is derived from the other.
if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
  return false;

// FIXME: In a modules build, do we need the entire path to be visible for us
// to be able to use the inheritance relationship?
if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
  return false;

return DerivedRD->isDerivedFrom(BaseRD);
2829}

2831/// Determine whether the type \p Derived is a C++ class that is
2832/// derived from the type \p Base.
2833bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
                       CXXBasePaths &Paths) {
if (!getLangOpts().CPlusPlus)
  return false;

CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
if (!DerivedRD)
  return false;

CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
if (!BaseRD)
  return false;

if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
  return false;

return DerivedRD->isDerivedFrom(BaseRD, Paths);
2850}

2852static void BuildBasePathArray(const CXXBasePath &Path,
                             CXXCastPath &BasePathArray) {
// We first go backward and check if we have a virtual base.
// FIXME: It would be better if CXXBasePath had the base specifier for
// the nearest virtual base.
unsigned Start = 0;
for (unsigned I = Path.size(); I != 0; --I) {
  if (Path[I - 1].Base->isVirtual()) {
    Start = I - 1;
    break;
  }
}

// Now add all bases.
for (unsigned I = Start, E = Path.size(); I != E; ++I)
  BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2868}


2871void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
                            CXXCastPath &BasePathArray) {
assert(BasePathArray.empty() && "Base path array must be empty!")((void)0);
assert(Paths.isRecordingPaths() && "Must record paths!")((void)0);
return ::BuildBasePathArray(Paths.front(), BasePathArray);
2876}
2877/// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2878/// conversion (where Derived and Base are class types) is
2879/// well-formed, meaning that the conversion is unambiguous (and
2880/// that all of the base classes are accessible). Returns true
2881/// and emits a diagnostic if the code is ill-formed, returns false
2882/// otherwise. Loc is the location where this routine should point to
2883/// if there is an error, and Range is the source range to highlight
2884/// if there is an error.
2885///
2886/// If either InaccessibleBaseID or AmbiguousBaseConvID are 0, then the
2887/// diagnostic for the respective type of error will be suppressed, but the
2888/// check for ill-formed code will still be performed.
2889bool
2890Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                 unsigned InaccessibleBaseID,
                                 unsigned AmbiguousBaseConvID,
                                 SourceLocation Loc, SourceRange Range,
                                 DeclarationName Name,
                                 CXXCastPath *BasePath,
                                 bool IgnoreAccess) {
// First, determine whether the path from Derived to Base is
// ambiguous. This is slightly more expensive than checking whether
// the Derived to Base conversion exists, because here we need to
// explore multiple paths to determine if there is an ambiguity.
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                   /*DetectVirtual=*/false);
bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
if (!DerivationOkay)
  return true;

const CXXBasePath *Path = nullptr;
if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
  Path = &Paths.front();

// For MSVC compatibility, check if Derived directly inherits from Base. Clang
// warns about this hierarchy under -Winaccessible-base, but MSVC allows the
// user to access such bases.
if (!Path && getLangOpts().MSVCCompat) {
  for (const CXXBasePath &PossiblePath : Paths) {
    if (PossiblePath.size() == 1) {
      Path = &PossiblePath;
      if (AmbiguousBaseConvID)
        Diag(Loc, diag::ext_ms_ambiguous_direct_base)
            << Base << Derived << Range;
      break;
    }
  }
}

if (Path) {
  if (!IgnoreAccess) {
    // Check that the base class can be accessed.
    switch (
        CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
    case AR_inaccessible:
      return true;
    case AR_accessible:
    case AR_dependent:
    case AR_delayed:
      break;
    }
  }

  // Build a base path if necessary.
  if (BasePath)
    ::BuildBasePathArray(*Path, *BasePath);
  return false;
}

if (AmbiguousBaseConvID) {
  // We know that the derived-to-base conversion is ambiguous, and
  // we're going to produce a diagnostic. Perform the derived-to-base
  // search just one more time to compute all of the possible paths so
  // that we can print them out. This is more expensive than any of
  // the previous derived-to-base checks we've done, but at this point
  // performance isn't as much of an issue.
  Paths.clear();
  Paths.setRecordingPaths(true);
  bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
  assert(StillOkay && "Can only be used with a derived-to-base conversion")((void)0);
  (void)StillOkay;

  // Build up a textual representation of the ambiguous paths, e.g.,
  // D -> B -> A, that will be used to illustrate the ambiguous
  // conversions in the diagnostic. We only print one of the paths
  // to each base class subobject.
  std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);

  Diag(Loc, AmbiguousBaseConvID)
  << Derived << Base << PathDisplayStr << Range << Name;
}
return true;
2969}

2971bool
2972Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
                                 SourceLocation Loc, SourceRange Range,
                                 CXXCastPath *BasePath,
                                 bool IgnoreAccess) {
return CheckDerivedToBaseConversion(
    Derived, Base, diag::err_upcast_to_inaccessible_base,
    diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
    BasePath, IgnoreAccess);
2980}


2983/// Builds a string representing ambiguous paths from a
2984/// specific derived class to different subobjects of the same base
2985/// class.
2986///
2987/// This function builds a string that can be used in error messages
2988/// to show the different paths that one can take through the
2989/// inheritance hierarchy to go from the derived class to different
2990/// subobjects of a base class. The result looks something like this:
2991/// @code
2992/// struct D -> struct B -> struct A
2993/// struct D -> struct C -> struct A
2994/// @endcode
2995std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
std::string PathDisplayStr;
std::set<unsigned> DisplayedPaths;
for (CXXBasePaths::paths_iterator Path = Paths.begin();
     Path != Paths.end(); ++Path) {
  if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
    // We haven't displayed a path to this particular base
    // class subobject yet.
    PathDisplayStr += "\n    ";
    PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
    for (CXXBasePath::const_iterator Element = Path->begin();
         Element != Path->end(); ++Element)
      PathDisplayStr += " -> " + Element->Base->getType().getAsString();
  }
}

return PathDisplayStr;
3012}

3014//===----------------------------------------------------------------------===//
3015// C++ class member Handling
3016//===----------------------------------------------------------------------===//

3018/// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
3019bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
                              SourceLocation ColonLoc,
                              const ParsedAttributesView &Attrs) {
assert(Access != AS_none && "Invalid kind for syntactic access specifier!")((void)0);
AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
                                                ASLoc, ColonLoc);
CurContext->addHiddenDecl(ASDecl);
return ProcessAccessDeclAttributeList(ASDecl, Attrs);
3027}

3029/// CheckOverrideControl - Check C++11 override control semantics.
3030void Sema::CheckOverrideControl(NamedDecl *D) {
if (D->isInvalidDecl())
  return;

// We only care about "override" and "final" declarations.
if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
  return;

CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);

// We can't check dependent instance methods.
if (MD && MD->isInstance() &&
    (MD->getParent()->hasAnyDependentBases() ||
     MD->getType()->isDependentType()))
  return;

if (MD && !MD->isVirtual()) {
  // If we have a non-virtual method, check if if hides a virtual method.
  // (In that case, it's most likely the method has the wrong type.)
  SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
  FindHiddenVirtualMethods(MD, OverloadedMethods);

  if (!OverloadedMethods.empty()) {
    if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
      Diag(OA->getLocation(),
           diag::override_keyword_hides_virtual_member_function)
        << "override" << (OverloadedMethods.size() > 1);
    } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
      Diag(FA->getLocation(),
           diag::override_keyword_hides_virtual_member_function)
        << (FA->isSpelledAsSealed() ? "sealed" : "final")
        << (OverloadedMethods.size() > 1);
    }
    NoteHiddenVirtualMethods(MD, OverloadedMethods);
    MD->setInvalidDecl();
    return;
  }
  // Fall through into the general case diagnostic.
  // FIXME: We might want to attempt typo correction here.
}

if (!MD || !MD->isVirtual()) {
  if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
    Diag(OA->getLocation(),
         diag::override_keyword_only_allowed_on_virtual_member_functions)
      << "override" << FixItHint::CreateRemoval(OA->getLocation());
    D->dropAttr<OverrideAttr>();
  }
  if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
    Diag(FA->getLocation(),
         diag::override_keyword_only_allowed_on_virtual_member_functions)
      << (FA->isSpelledAsSealed() ? "sealed" : "final")
      << FixItHint::CreateRemoval(FA->getLocation());
    D->dropAttr<FinalAttr>();
  }
  return;
}

// C++11 [class.virtual]p5:
//   If a function is marked with the virt-specifier override and
//   does not override a member function of a base class, the program is
//   ill-formed.
bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
  Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
    << MD->getDeclName();
3096}

3098void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D, bool Inconsistent) {
if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
  return;
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
  return;

SourceLocation Loc = MD->getLocation();
SourceLocation SpellingLoc = Loc;
if (getSourceManager().isMacroArgExpansion(Loc))
  SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
    return;

if (MD->size_overridden_methods() > 0) {
  auto EmitDiag = [&](unsigned DiagInconsistent, unsigned DiagSuggest) {
    unsigned DiagID =
        Inconsistent && !Diags.isIgnored(DiagInconsistent, MD->getLocation())
            ? DiagInconsistent
            : DiagSuggest;
    Diag(MD->getLocation(), DiagID) << MD->getDeclName();
    const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
    Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
  };
  if (isa<CXXDestructorDecl>(MD))
    EmitDiag(
        diag::warn_inconsistent_destructor_marked_not_override_overriding,
        diag::warn_suggest_destructor_marked_not_override_overriding);
  else
    EmitDiag(diag::warn_inconsistent_function_marked_not_override_overriding,
             diag::warn_suggest_function_marked_not_override_overriding);
}
3131}

3133/// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3134/// function overrides a virtual member function marked 'final', according to
3135/// C++11 [class.virtual]p4.
3136bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
                                                const CXXMethodDecl *Old) {
FinalAttr *FA = Old->getAttr<FinalAttr>();
if (!FA)
  return false;

Diag(New->getLocation(), diag::err_final_function_overridden)
  << New->getDeclName()
  << FA->isSpelledAsSealed();
Diag(Old->getLocation(), diag::note_overridden_virtual_function);
return true;
3147}

3149static bool InitializationHasSideEffects(const FieldDecl &FD) {
const Type *T = FD.getType()->getBaseElementTypeUnsafe();
// FIXME: Destruction of ObjC lifetime types has side-effects.
if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
  return !RD->isCompleteDefinition() ||
         !RD->hasTrivialDefaultConstructor() ||
         !RD->hasTrivialDestructor();
return false;
3157}

3159static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
ParsedAttributesView::const_iterator Itr =
    llvm::find_if(list, [](const ParsedAttr &AL) {
      return AL.isDeclspecPropertyAttribute();
    });
if (Itr != list.end())
  return &*Itr;
return nullptr;
3167}

3169// Check if there is a field shadowing.
3170void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
                                    DeclarationName FieldName,
                                    const CXXRecordDecl *RD,
                                    bool DeclIsField) {
if (Diags.isIgnored(diag::warn_shadow_field, Loc))
  return;

// To record a shadowed field in a base
std::map<CXXRecordDecl*, NamedDecl*> Bases;
auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
                         CXXBasePath &Path) {
  const auto Base = Specifier->getType()->getAsCXXRecordDecl();
  // Record an ambiguous path directly
  if (Bases.find(Base) != Bases.end())
    return true;
  for (const auto Field : Base->lookup(FieldName)) {
    if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
        Field->getAccess() != AS_private) {
      assert(Field->getAccess() != AS_none)((void)0);
      assert(Bases.find(Base) == Bases.end())((void)0);
      Bases[Base] = Field;
      return true;
    }
  }
  return false;
};

CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                   /*DetectVirtual=*/true);
if (!RD->lookupInBases(FieldShadowed, Paths))
  return;

for (const auto &P : Paths) {
  auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
  auto It = Bases.find(Base);
  // Skip duplicated bases
  if (It == Bases.end())
    continue;
  auto BaseField = It->second;
  assert(BaseField->getAccess() != AS_private)((void)0);
  if (AS_none !=
      CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
    Diag(Loc, diag::warn_shadow_field)
      << FieldName << RD << Base << DeclIsField;
    Diag(BaseField->getLocation(), diag::note_shadow_field);
    Bases.erase(It);
  }
}
3218}

3220/// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3221/// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3222/// bitfield width if there is one, 'InitExpr' specifies the initializer if
3223/// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3224/// present (but parsing it has been deferred).
3225NamedDecl *
3226Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
                             MultiTemplateParamsArg TemplateParameterLists,
                             Expr *BW, const VirtSpecifiers &VS,
                             InClassInitStyle InitStyle) {
const DeclSpec &DS = D.getDeclSpec();
DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
DeclarationName Name = NameInfo.getName();
SourceLocation Loc = NameInfo.getLoc();

// For anonymous bitfields, the location should point to the type.
if (Loc.isInvalid())
  Loc = D.getBeginLoc();

Expr *BitWidth = static_cast<Expr*>(BW);

assert(isa<CXXRecordDecl>(CurContext))((void)0);
assert(!DS.isFriendSpecified())((void)0);

bool isFunc = D.isDeclarationOfFunction();
const ParsedAttr *MSPropertyAttr =
    getMSPropertyAttr(D.getDeclSpec().getAttributes());

if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
  // The Microsoft extension __interface only permits public member functions
  // and prohibits constructors, destructors, operators, non-public member
  // functions, static methods and data members.
  unsigned InvalidDecl;
  bool ShowDeclName = true;
  if (!isFunc &&
      (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
    InvalidDecl = 0;
  else if (!isFunc)
    InvalidDecl = 1;
  else if (AS != AS_public)
    InvalidDecl = 2;
  else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
    InvalidDecl = 3;
  else switch (Name.getNameKind()) {
    case DeclarationName::CXXConstructorName:
      InvalidDecl = 4;
      ShowDeclName = false;
      break;

    case DeclarationName::CXXDestructorName:
      InvalidDecl = 5;
      ShowDeclName = false;
      break;

    case DeclarationName::CXXOperatorName:
    case DeclarationName::CXXConversionFunctionName:
      InvalidDecl = 6;
      break;

    default:
      InvalidDecl = 0;
      break;
  }

  if (InvalidDecl) {
    if (ShowDeclName)
      Diag(Loc, diag::err_invalid_member_in_interface)
        << (InvalidDecl-1) << Name;
    else
      Diag(Loc, diag::err_invalid_member_in_interface)
        << (InvalidDecl-1) << "";
    return nullptr;
  }
}

// C++ 9.2p6: A member shall not be declared to have automatic storage
// duration (auto, register) or with the extern storage-class-specifier.
// C++ 7.1.1p8: The mutable specifier can be applied only to names of class
// data members and cannot be applied to names declared const or static,
// and cannot be applied to reference members.
switch (DS.getStorageClassSpec()) {
case DeclSpec::SCS_unspecified:
case DeclSpec::SCS_typedef:
case DeclSpec::SCS_static:
  break;
case DeclSpec::SCS_mutable:
  if (isFunc) {
    Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);

    // FIXME: It would be nicer if the keyword was ignored only for this
    // declarator. Otherwise we could get follow-up errors.
    D.getMutableDeclSpec().ClearStorageClassSpecs();
  }
  break;
default:
  Diag(DS.getStorageClassSpecLoc(),
       diag::err_storageclass_invalid_for_member);
  D.getMutableDeclSpec().ClearStorageClassSpecs();
  break;
}

bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
                     DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
                    !isFunc);

if (DS.hasConstexprSpecifier() && isInstField) {
  SemaDiagnosticBuilder B =
      Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
  SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
  if (InitStyle == ICIS_NoInit) {
    B << 0 << 0;
    if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
      B << FixItHint::CreateRemoval(ConstexprLoc);
    else {
      B << FixItHint::CreateReplacement(ConstexprLoc, "const");
      D.getMutableDeclSpec().ClearConstexprSpec();
      const char *PrevSpec;
      unsigned DiagID;
      bool Failed = D.getMutableDeclSpec().SetTypeQual(
          DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
      (void)Failed;
      assert(!Failed && "Making a constexpr member const shouldn't fail")((void)0);
    }
  } else {
    B << 1;
    const char *PrevSpec;
    unsigned DiagID;
    if (D.getMutableDeclSpec().SetStorageClassSpec(
        *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
        Context.getPrintingPolicy())) {
      assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&((void)0)
             "This is the only DeclSpec that should fail to be applied")((void)0);
      B << 1;
    } else {
      B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
      isInstField = false;
    }
  }
}

NamedDecl *Member;
if (isInstField) {
  CXXScopeSpec &SS = D.getCXXScopeSpec();

  // Data members must have identifiers for names.
  if (!Name.isIdentifier()) {
    Diag(Loc, diag::err_bad_variable_name)
      << Name;
    return nullptr;
  }

  IdentifierInfo *II = Name.getAsIdentifierInfo();

  // Member field could not be with "template" keyword.
  // So TemplateParameterLists should be empty in this case.
  if (TemplateParameterLists.size()) {
    TemplateParameterList* TemplateParams = TemplateParameterLists[0];
    if (TemplateParams->size()) {
      // There is no such thing as a member field template.
      Diag(D.getIdentifierLoc(), diag::err_template_member)
          << II
          << SourceRange(TemplateParams->getTemplateLoc(),
              TemplateParams->getRAngleLoc());
    } else {
      // There is an extraneous 'template<>' for this member.
      Diag(TemplateParams->getTemplateLoc(),
          diag::err_template_member_noparams)
          << II
          << SourceRange(TemplateParams->getTemplateLoc(),
              TemplateParams->getRAngleLoc());
    }
    return nullptr;
  }

  if (SS.isSet() && !SS.isInvalid()) {
    // The user provided a superfluous scope specifier inside a class
    // definition:
    //
    // class X {
    //   int X::member;
    // };
    if (DeclContext *DC = computeDeclContext(SS, false))
      diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
                                   D.getName().getKind() ==
                                       UnqualifiedIdKind::IK_TemplateId);
    else
      Diag(D.getIdentifierLoc(), diag::err_member_qualification)
        << Name << SS.getRange();

    SS.clear();
  }

  if (MSPropertyAttr) {
    Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
                              BitWidth, InitStyle, AS, *MSPropertyAttr);
    if (!Member)
      return nullptr;
    isInstField = false;
  } else {
    Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
                              BitWidth, InitStyle, AS);
    if (!Member)
      return nullptr;
  }

  CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
} else {
  Member = HandleDeclarator(S, D, TemplateParameterLists);
  if (!Member)
    return nullptr;

  // Non-instance-fields can't have a bitfield.
  if (BitWidth) {
    if (Member->isInvalidDecl()) {
      // don't emit another diagnostic.
    } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
      // C++ 9.6p3: A bit-field shall not be a static member.
      // "static member 'A' cannot be a bit-field"
      Diag(Loc, diag::err_static_not_bitfield)
        << Name << BitWidth->getSourceRange();
    } else if (isa<TypedefDecl>(Member)) {
      // "typedef member 'x' cannot be a bit-field"
      Diag(Loc, diag::err_typedef_not_bitfield)
        << Name << BitWidth->getSourceRange();
    } else {
      // A function typedef ("typedef int f(); f a;").
      // C++ 9.6p3: A bit-field shall have integral or enumeration type.
      Diag(Loc, diag::err_not_integral_type_bitfield)
        << Name << cast<ValueDecl>(Member)->getType()
        << BitWidth->getSourceRange();
    }

    BitWidth = nullptr;
    Member->setInvalidDecl();
  }

  NamedDecl *NonTemplateMember = Member;
  if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
    NonTemplateMember = FunTmpl->getTemplatedDecl();
  else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
    NonTemplateMember = VarTmpl->getTemplatedDecl();

  Member->setAccess(AS);

  // If we have declared a member function template or static data member
  // template, set the access of the templated declaration as well.
  if (NonTemplateMember != Member)
    NonTemplateMember->setAccess(AS);

  // C++ [temp.deduct.guide]p3:
  //   A deduction guide [...] for a member class template [shall be
  //   declared] with the same access [as the template].
  if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
    auto *TD = DG->getDeducedTemplate();
    // Access specifiers are only meaningful if both the template and the
    // deduction guide are from the same scope.
    if (AS != TD->getAccess() &&
        TD->getDeclContext()->getRedeclContext()->Equals(
            DG->getDeclContext()->getRedeclContext())) {
      Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
      Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
          << TD->getAccess();
      const AccessSpecDecl *LastAccessSpec = nullptr;
      for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
        if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
          LastAccessSpec = AccessSpec;
      }
      assert(LastAccessSpec && "differing access with no access specifier")((void)0);
      Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
          << AS;
    }
  }
}

if (VS.isOverrideSpecified())
  Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
                                       AttributeCommonInfo::AS_Keyword));
if (VS.isFinalSpecified())
  Member->addAttr(FinalAttr::Create(
      Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
      static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));

if (VS.getLastLocation().isValid()) {
  // Update the end location of a method that has a virt-specifiers.
  if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
    MD->setRangeEnd(VS.getLastLocation());
}

CheckOverrideControl(Member);

assert((Name || isInstField) && "No identifier for non-field ?")((void)0);

if (isInstField) {
  FieldDecl *FD = cast<FieldDecl>(Member);
  FieldCollector->Add(FD);

  if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
    // Remember all explicit private FieldDecls that have a name, no side
    // effects and are not part of a dependent type declaration.
    if (!FD->isImplicit() && FD->getDeclName() &&
        FD->getAccess() == AS_private &&
        !FD->hasAttr<UnusedAttr>() &&
        !FD->getParent()->isDependentContext() &&
        !InitializationHasSideEffects(*FD))
      UnusedPrivateFields.insert(FD);
  }
}

return Member;
3529}

3531namespace {
class UninitializedFieldVisitor
    : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
  Sema &S;
  // List of Decls to generate a warning on.  Also remove Decls that become
  // initialized.
  llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
  // List of base classes of the record.  Classes are removed after their
  // initializers.
  llvm::SmallPtrSetImpl<QualType> &BaseClasses;
  // Vector of decls to be removed from the Decl set prior to visiting the
  // nodes.  These Decls may have been initialized in the prior initializer.
  llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
  // If non-null, add a note to the warning pointing back to the constructor.
  const CXXConstructorDecl *Constructor;
  // Variables to hold state when processing an initializer list.  When
  // InitList is true, special case initialization of FieldDecls matching
  // InitListFieldDecl.
  bool InitList;
  FieldDecl *InitListFieldDecl;
  llvm::SmallVector<unsigned, 4> InitFieldIndex;

public:
  typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
  UninitializedFieldVisitor(Sema &S,
                            llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
                            llvm::SmallPtrSetImpl<QualType> &BaseClasses)
    : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
      Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}

  // Returns true if the use of ME is not an uninitialized use.
  bool IsInitListMemberExprInitialized(MemberExpr *ME,
                                       bool CheckReferenceOnly) {
    llvm::SmallVector<FieldDecl*, 4> Fields;
    bool ReferenceField = false;
    while (ME) {
      FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
      if (!FD)
        return false;
      Fields.push_back(FD);
      if (FD->getType()->isReferenceType())
        ReferenceField = true;
      ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
    }

    // Binding a reference to an uninitialized field is not an
    // uninitialized use.
    if (CheckReferenceOnly && !ReferenceField)
      return true;

    llvm::SmallVector<unsigned, 4> UsedFieldIndex;
    // Discard the first field since it is the field decl that is being
    // initialized.
    for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
      UsedFieldIndex.push_back((*I)->getFieldIndex());
    }

    for (auto UsedIter = UsedFieldIndex.begin(),
              UsedEnd = UsedFieldIndex.end(),
              OrigIter = InitFieldIndex.begin(),
              OrigEnd = InitFieldIndex.end();
         UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
      if (*UsedIter < *OrigIter)
        return true;
      if (*UsedIter > *OrigIter)
        break;
    }

    return false;
  }

  void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
                        bool AddressOf) {
    if (isa<EnumConstantDecl>(ME->getMemberDecl()))
      return;

    // FieldME is the inner-most MemberExpr that is not an anonymous struct
    // or union.
    MemberExpr *FieldME = ME;

    bool AllPODFields = FieldME->getType().isPODType(S.Context);

    Expr *Base = ME;
    while (MemberExpr *SubME =
               dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {

      if (isa<VarDecl>(SubME->getMemberDecl()))
        return;

      if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
        if (!FD->isAnonymousStructOrUnion())
          FieldME = SubME;

      if (!FieldME->getType().isPODType(S.Context))
        AllPODFields = false;

      Base = SubME->getBase();
    }

    if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts())) {
      Visit(Base);
      return;
    }

    if (AddressOf && AllPODFields)
      return;

    ValueDecl* FoundVD = FieldME->getMemberDecl();

    if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
      while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
        BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
      }

      if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
        QualType T = BaseCast->getType();
        if (T->isPointerType() &&
            BaseClasses.count(T->getPointeeType())) {
          S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
              << T->getPointeeType() << FoundVD;
        }
      }
    }

    if (!Decls.count(FoundVD))
      return;

    const bool IsReference = FoundVD->getType()->isReferenceType();

    if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
      // Special checking for initializer lists.
      if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
        return;
      }
    } else {
      // Prevent double warnings on use of unbounded references.
      if (CheckReferenceOnly && !IsReference)
        return;
    }

    unsigned diag = IsReference
        ? diag::warn_reference_field_is_uninit
        : diag::warn_field_is_uninit;
    S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
    if (Constructor)
      S.Diag(Constructor->getLocation(),
             diag::note_uninit_in_this_constructor)
        << (Constructor->isDefaultConstructor() && Constructor->isImplicit());

  }

  void HandleValue(Expr *E, bool AddressOf) {
    E = E->IgnoreParens();

    if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
      HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
                       AddressOf /*AddressOf*/);
      return;
    }

    if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
      Visit(CO->getCond());
      HandleValue(CO->getTrueExpr(), AddressOf);
      HandleValue(CO->getFalseExpr(), AddressOf);
      return;
    }

    if (BinaryConditionalOperator *BCO =
            dyn_cast<BinaryConditionalOperator>(E)) {
      Visit(BCO->getCond());
      HandleValue(BCO->getFalseExpr(), AddressOf);
      return;
    }

    if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
      HandleValue(OVE->getSourceExpr(), AddressOf);
      return;
    }

    if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
      switch (BO->getOpcode()) {
      default:
        break;
      case(BO_PtrMemD):
      case(BO_PtrMemI):
        HandleValue(BO->getLHS(), AddressOf);
        Visit(BO->getRHS());
        return;
      case(BO_Comma):
        Visit(BO->getLHS());
        HandleValue(BO->getRHS(), AddressOf);
        return;
      }
    }

    Visit(E);
  }

  void CheckInitListExpr(InitListExpr *ILE) {
    InitFieldIndex.push_back(0);
    for (auto Child : ILE->children()) {
      if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
        CheckInitListExpr(SubList);
      } else {
        Visit(Child);
      }
      ++InitFieldIndex.back();
    }
    InitFieldIndex.pop_back();
  }

  void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
                        FieldDecl *Field, const Type *BaseClass) {
    // Remove Decls that may have been initialized in the previous
    // initializer.
    for (ValueDecl* VD : DeclsToRemove)
      Decls.erase(VD);
    DeclsToRemove.clear();

    Constructor = FieldConstructor;
    InitListExpr *ILE = dyn_cast<InitListExpr>(E);

    if (ILE && Field) {
      InitList = true;
      InitListFieldDecl = Field;
      InitFieldIndex.clear();
      CheckInitListExpr(ILE);
    } else {
      InitList = false;
      Visit(E);
    }

    if (Field)
      Decls.erase(Field);
    if (BaseClass)
      BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
  }

  void VisitMemberExpr(MemberExpr *ME) {
    // All uses of unbounded reference fields will warn.
    HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
  }

  void VisitImplicitCastExpr(ImplicitCastExpr *E) {
    if (E->getCastKind() == CK_LValueToRValue) {
      HandleValue(E->getSubExpr(), false /*AddressOf*/);
      return;
    }

    Inherited::VisitImplicitCastExpr(E);
  }

  void VisitCXXConstructExpr(CXXConstructExpr *E) {
    if (E->getConstructor()->isCopyConstructor()) {
      Expr *ArgExpr = E->getArg(0);
      if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
        if (ILE->getNumInits() == 1)
          ArgExpr = ILE->getInit(0);
      if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
        if (ICE->getCastKind() == CK_NoOp)
          ArgExpr = ICE->getSubExpr();
      HandleValue(ArgExpr, false /*AddressOf*/);
      return;
    }
    Inherited::VisitCXXConstructExpr(E);
  }

  void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
    Expr *Callee = E->getCallee();
    if (isa<MemberExpr>(Callee)) {
      HandleValue(Callee, false /*AddressOf*/);
      for (auto Arg : E->arguments())
        Visit(Arg);
      return;
    }

    Inherited::VisitCXXMemberCallExpr(E);
  }

  void VisitCallExpr(CallExpr *E) {
    // Treat std::move as a use.
    if (E->isCallToStdMove()) {
      HandleValue(E->getArg(0), /*AddressOf=*/false);
      return;
    }

    Inherited::VisitCallExpr(E);
  }

  void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
    Expr *Callee = E->getCallee();

    if (isa<UnresolvedLookupExpr>(Callee))
      return Inherited::VisitCXXOperatorCallExpr(E);

    Visit(Callee);
    for (auto Arg : E->arguments())
      HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
  }

  void VisitBinaryOperator(BinaryOperator *E) {
    // If a field assignment is detected, remove the field from the
    // uninitiailized field set.
    if (E->getOpcode() == BO_Assign)
      if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
        if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
          if (!FD->getType()->isReferenceType())
            DeclsToRemove.push_back(FD);

    if (E->isCompoundAssignmentOp()) {
      HandleValue(E->getLHS(), false /*AddressOf*/);
      Visit(E->getRHS());
      return;
    }

    Inherited::VisitBinaryOperator(E);
  }

  void VisitUnaryOperator(UnaryOperator *E) {
    if (E->isIncrementDecrementOp()) {
      HandleValue(E->getSubExpr(), false /*AddressOf*/);
      return;
    }
    if (E->getOpcode() == UO_AddrOf) {
      if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
        HandleValue(ME->getBase(), true /*AddressOf*/);
        return;
      }
    }

    Inherited::VisitUnaryOperator(E);
  }
};

// Diagnose value-uses of fields to initialize themselves, e.g.
//   foo(foo)
// where foo is not also a parameter to the constructor.
// Also diagnose across field uninitialized use such as
//   x(y), y(x)
// TODO: implement -Wuninitialized and fold this into that framework.
static void DiagnoseUninitializedFields(
    Sema &SemaRef, const CXXConstructorDecl *Constructor) {

  if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
                                         Constructor->getLocation())) {
    return;
  }

  if (Constructor->isInvalidDecl())
    return;

  const CXXRecordDecl *RD = Constructor->getParent();

  if (RD->isDependentContext())
    return;

  // Holds fields that are uninitialized.
  llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;

  // At the beginning, all fields are uninitialized.
  for (auto *I : RD->decls()) {
    if (auto *FD = dyn_cast<FieldDecl>(I)) {
      UninitializedFields.insert(FD);
    } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
      UninitializedFields.insert(IFD->getAnonField());
    }
  }

  llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
  for (auto I : RD->bases())
    UninitializedBaseClasses.insert(I.getType().getCanonicalType());

  if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
    return;

  UninitializedFieldVisitor UninitializedChecker(SemaRef,
                                                 UninitializedFields,
                                                 UninitializedBaseClasses);

  for (const auto *FieldInit : Constructor->inits()) {
    if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
      break;

    Expr *InitExpr = FieldInit->getInit();
    if (!InitExpr)
      continue;

    if (CXXDefaultInitExpr *Default =
            dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
      InitExpr = Default->getExpr();
      if (!InitExpr)
        continue;
      // In class initializers will point to the constructor.
      UninitializedChecker.CheckInitializer(InitExpr, Constructor,
                                            FieldInit->getAnyMember(),
                                            FieldInit->getBaseClass());
    } else {
      UninitializedChecker.CheckInitializer(InitExpr, nullptr,
                                            FieldInit->getAnyMember(),
                                            FieldInit->getBaseClass());
    }
  }
}
3934} // namespace

3936/// Enter a new C++ default initializer scope. After calling this, the
3937/// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3938/// parsing or instantiating the initializer failed.
3939void Sema::ActOnStartCXXInClassMemberInitializer() {
// Create a synthetic function scope to represent the call to the constructor
// that notionally surrounds a use of this initializer.
PushFunctionScope();
3943}

3945void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
if (!D.isFunctionDeclarator())
  return;
auto &FTI = D.getFunctionTypeInfo();
if (!FTI.Params)
  return;
for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
                                                        FTI.NumParams)) {
  auto *ParamDecl = cast<NamedDecl>(Param.Param);
  if (ParamDecl->getDeclName())
    PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
}
3957}

3959ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
return ActOnRequiresClause(ConstraintExpr);
3961}

3963ExprResult Sema::ActOnRequiresClause(ExprResult ConstraintExpr) {
if (ConstraintExpr.isInvalid())
  return ExprError();

ConstraintExpr = CorrectDelayedTyposInExpr(ConstraintExpr);
if (ConstraintExpr.isInvalid())
  return ExprError();

if (DiagnoseUnexpandedParameterPack(ConstraintExpr.get(),
                                    UPPC_RequiresClause))
  return ExprError();

return ConstraintExpr;
3976}

3978/// This is invoked after parsing an in-class initializer for a
3979/// non-static C++ class member, and after instantiating an in-class initializer
3980/// in a class template. Such actions are deferred until the class is complete.
3981void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
                                                SourceLocation InitLoc,
                                                Expr *InitExpr) {
// Pop the notional constructor scope we created earlier.
PopFunctionScopeInfo(nullptr, D);

FieldDecl *FD = dyn_cast<FieldDecl>(D);
assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&((void)0)
       "must set init style when field is created")((void)0);

if (!InitExpr) {
  D->setInvalidDecl();
  if (FD)
    FD->removeInClassInitializer();
  return;
}

if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
  FD->setInvalidDecl();
  FD->removeInClassInitializer();
  return;
}

ExprResult Init = InitExpr;
if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
  InitializedEntity Entity =
      InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
  InitializationKind Kind =
      FD->getInClassInitStyle() == ICIS_ListInit
          ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
                                                 InitExpr->getBeginLoc(),
                                                 InitExpr->getEndLoc())
          : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
  InitializationSequence Seq(*this, Entity, Kind, InitExpr);
  Init = Seq.Perform(*this, Entity, Kind, InitExpr);
  if (Init.isInvalid()) {
    FD->setInvalidDecl();
    return;
  }
}

// C++11 [class.base.init]p7:
//   The initialization of each base and member constitutes a
//   full-expression.
Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
if (Init.isInvalid()) {
  FD->setInvalidDecl();
  return;
}

InitExpr = Init.get();

FD->setInClassInitializer(InitExpr);
4034}

4036/// Find the direct and/or virtual base specifiers that
4037/// correspond to the given base type, for use in base initialization
4038/// within a constructor.
4039static bool FindBaseInitializer(Sema &SemaRef,
                              CXXRecordDecl *ClassDecl,
                              QualType BaseType,
                              const CXXBaseSpecifier *&DirectBaseSpec,
                              const CXXBaseSpecifier *&VirtualBaseSpec) {
// First, check for a direct base class.
DirectBaseSpec = nullptr;
for (const auto &Base : ClassDecl->bases()) {
  if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
    // We found a direct base of this type. That's what we're
    // initializing.
    DirectBaseSpec = &Base;
    break;
  }
}

// Check for a virtual base class.
// FIXME: We might be able to short-circuit this if we know in advance that
// there are no virtual bases.
VirtualBaseSpec = nullptr;
if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
  // We haven't found a base yet; search the class hierarchy for a
  // virtual base class.
  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
                     /*DetectVirtual=*/false);
  if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
                            SemaRef.Context.getTypeDeclType(ClassDecl),
                            BaseType, Paths)) {
    for (CXXBasePaths::paths_iterator Path = Paths.begin();
         Path != Paths.end(); ++Path) {
      if (Path->back().Base->isVirtual()) {
        VirtualBaseSpec = Path->back().Base;
        break;
      }
    }
  }
}

return DirectBaseSpec || VirtualBaseSpec;
4078}

4080/// Handle a C++ member initializer using braced-init-list syntax.
4081MemInitResult
4082Sema::ActOnMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        Expr *InitList,
                        SourceLocation EllipsisLoc) {
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
                           DS, IdLoc, InitList,
                           EllipsisLoc);
4094}

4096/// Handle a C++ member initializer using parentheses syntax.
4097MemInitResult
4098Sema::ActOnMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        SourceLocation LParenLoc,
                        ArrayRef<Expr *> Args,
                        SourceLocation RParenLoc,
                        SourceLocation EllipsisLoc) {
Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
                           DS, IdLoc, List, EllipsisLoc);
4112}

4114namespace {

4116// Callback to only accept typo corrections that can be a valid C++ member
4117// intializer: either a non-static field member or a base class.
4118class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4119public:
explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
    : ClassDecl(ClassDecl) {}

bool ValidateCandidate(const TypoCorrection &candidate) override {
  if (NamedDecl *ND = candidate.getCorrectionDecl()) {
    if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
      return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
    return isa<TypeDecl>(ND);
  }
  return false;
}

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

4136private:
CXXRecordDecl *ClassDecl;
4138};

4140}

4142ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
                                           CXXScopeSpec &SS,
                                           ParsedType TemplateTypeTy,
                                           IdentifierInfo *MemberOrBase) {
if (SS.getScopeRep() || TemplateTypeTy)
  return nullptr;
for (auto *D : ClassDecl->lookup(MemberOrBase))
  if (isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D))
    return cast<ValueDecl>(D);
return nullptr;
4152}

4154/// Handle a C++ member initializer.
4155MemInitResult
4156Sema::BuildMemInitializer(Decl *ConstructorD,
                        Scope *S,
                        CXXScopeSpec &SS,
                        IdentifierInfo *MemberOrBase,
                        ParsedType TemplateTypeTy,
                        const DeclSpec &DS,
                        SourceLocation IdLoc,
                        Expr *Init,
                        SourceLocation EllipsisLoc) {
ExprResult Res = CorrectDelayedTyposInExpr(Init);
if (!Res.isUsable())
  return true;
Init = Res.get();

if (!ConstructorD)
  return true;

AdjustDeclIfTemplate(ConstructorD);

CXXConstructorDecl *Constructor
  = dyn_cast<CXXConstructorDecl>(ConstructorD);
if (!Constructor) {
  // The user wrote a constructor initializer on a function that is
  // not a C++ constructor. Ignore the error for now, because we may
  // have more member initializers coming; we'll diagnose it just
  // once in ActOnMemInitializers.
  return true;
}

CXXRecordDecl *ClassDecl = Constructor->getParent();

// C++ [class.base.init]p2:
//   Names in a mem-initializer-id are looked up in the scope of the
//   constructor's class and, if not found in that scope, are looked
//   up in the scope containing the constructor's definition.
//   [Note: if the constructor's class contains a member with the
//   same name as a direct or virtual base class of the class, a
//   mem-initializer-id naming the member or base class and composed
//   of a single identifier refers to the class member. A
//   mem-initializer-id for the hidden base class may be specified
//   using a qualified name. ]

// Look for a member, first.
if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
        ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
  if (EllipsisLoc.isValid())
    Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
        << MemberOrBase
        << SourceRange(IdLoc, Init->getSourceRange().getEnd());

  return BuildMemberInitializer(Member, Init, IdLoc);
}
// It didn't name a member, so see if it names a class.
QualType BaseType;
TypeSourceInfo *TInfo = nullptr;

if (TemplateTypeTy) {
  BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
  if (BaseType.isNull())
    return true;
} else if (DS.getTypeSpecType() == TST_decltype) {
  BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
} else if (DS.getTypeSpecType() == TST_decltype_auto) {
  Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
  return true;
} else {
  LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
  LookupParsedName(R, S, &SS);

  TypeDecl *TyD = R.getAsSingle<TypeDecl>();
  if (!TyD) {
    if (R.isAmbiguous()) return true;

    // We don't want access-control diagnostics here.
    R.suppressDiagnostics();

    if (SS.isSet() && isDependentScopeSpecifier(SS)) {
      bool NotUnknownSpecialization = false;
      DeclContext *DC = computeDeclContext(SS, false);
      if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
        NotUnknownSpecialization = !Record->hasAnyDependentBases();

      if (!NotUnknownSpecialization) {
        // When the scope specifier can refer to a member of an unknown
        // specialization, we take it as a type name.
        BaseType = CheckTypenameType(ETK_None, SourceLocation(),
                                     SS.getWithLocInContext(Context),
                                     *MemberOrBase, IdLoc);
        if (BaseType.isNull())
          return true;

        TInfo = Context.CreateTypeSourceInfo(BaseType);
        DependentNameTypeLoc TL =
            TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
        if (!TL.isNull()) {
          TL.setNameLoc(IdLoc);
          TL.setElaboratedKeywordLoc(SourceLocation());
          TL.setQualifierLoc(SS.getWithLocInContext(Context));
        }

        R.clear();
        R.setLookupName(MemberOrBase);
      }
    }

    // If no results were found, try to correct typos.
    TypoCorrection Corr;
    MemInitializerValidatorCCC CCC(ClassDecl);
    if (R.empty() && BaseType.isNull() &&
        (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
                            CCC, CTK_ErrorRecovery, ClassDecl))) {
      if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
        // We have found a non-static data member with a similar
        // name to what was typed; complain and initialize that
        // member.
        diagnoseTypo(Corr,
                     PDiag(diag::err_mem_init_not_member_or_class_suggest)
                       << MemberOrBase << true);
        return BuildMemberInitializer(Member, Init, IdLoc);
      } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
        const CXXBaseSpecifier *DirectBaseSpec;
        const CXXBaseSpecifier *VirtualBaseSpec;
        if (FindBaseInitializer(*this, ClassDecl,
                                Context.getTypeDeclType(Type),
                                DirectBaseSpec, VirtualBaseSpec)) {
          // We have found a direct or virtual base class with a
          // similar name to what was typed; complain and initialize
          // that base class.
          diagnoseTypo(Corr,
                       PDiag(diag::err_mem_init_not_member_or_class_suggest)
                         << MemberOrBase << false,
                       PDiag() /*Suppress note, we provide our own.*/);

          const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
                                                            : VirtualBaseSpec;
          Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
              << BaseSpec->getType() << BaseSpec->getSourceRange();

          TyD = Type;
        }
      }
    }

    if (!TyD && BaseType.isNull()) {
      Diag(IdLoc, diag::err_mem_init_not_member_or_class)
        << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
      return true;
    }
  }

  if (BaseType.isNull()) {
    BaseType = Context.getTypeDeclType(TyD);
    MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
    if (SS.isSet()) {
      BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
                                           BaseType);
      TInfo = Context.CreateTypeSourceInfo(BaseType);
      ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
      TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
      TL.setElaboratedKeywordLoc(SourceLocation());
      TL.setQualifierLoc(SS.getWithLocInContext(Context));
    }
  }
}

if (!TInfo)
  TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);

return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4325}

4327MemInitResult
4328Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
                           SourceLocation IdLoc) {
FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
assert((DirectMember || IndirectMember) &&((void)0)
       "Member must be a FieldDecl or IndirectFieldDecl")((void)0);

if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
  return true;

if (Member->isInvalidDecl())
  return true;

MultiExprArg Args;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
} else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
  Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
} else {
  // Template instantiation doesn't reconstruct ParenListExprs for us.
  Args = Init;
}

SourceRange InitRange = Init->getSourceRange();

if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
  // Can't check initialization for a member of dependent type or when
  // any of the arguments are type-dependent expressions.
  DiscardCleanupsInEvaluationContext();
} else {
  bool InitList = false;
  if (isa<InitListExpr>(Init)) {
    InitList = true;
    Args = Init;
  }

  // Initialize the member.
  InitializedEntity MemberEntity =
    DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
                 : InitializedEntity::InitializeMember(IndirectMember,
                                                       nullptr);
  InitializationKind Kind =
      InitList ? InitializationKind::CreateDirectList(
                     IdLoc, Init->getBeginLoc(), Init->getEndLoc())
               : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
                                                  InitRange.getEnd());

  InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
  ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
                                          nullptr);
  if (MemberInit.isInvalid())
    return true;

  // C++11 [class.base.init]p7:
  //   The initialization of each base and member constitutes a
  //   full-expression.
  MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
                                   /*DiscardedValue*/ false);
  if (MemberInit.isInvalid())
    return true;

  Init = MemberInit.get();
}

if (DirectMember) {
  return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd());
} else {
  return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd());
}
4401}

4403MemInitResult
4404Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
                               CXXRecordDecl *ClassDecl) {
SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
if (!LangOpts.CPlusPlus11)
  return Diag(NameLoc, diag::err_delegating_ctor)
    << TInfo->getTypeLoc().getLocalSourceRange();
Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);

bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  InitList = false;
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}

SourceRange InitRange = Init->getSourceRange();
// Initialize the object.
InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
                                   QualType(ClassDecl->getTypeForDecl(), 0));
InitializationKind Kind =
    InitList ? InitializationKind::CreateDirectList(
                   NameLoc, Init->getBeginLoc(), Init->getEndLoc())
             : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
                                                InitRange.getEnd());
InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
                                            Args, nullptr);
if (DelegationInit.isInvalid())
  return true;

assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&((void)0)
       "Delegating constructor with no target?")((void)0);

// C++11 [class.base.init]p7:
//   The initialization of each base and member constitutes a
//   full-expression.
DelegationInit = ActOnFinishFullExpr(
    DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
if (DelegationInit.isInvalid())
  return true;

// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
  DelegationInit = Init;

return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
                                        DelegationInit.getAs<Expr>(),
                                        InitRange.getEnd());
4458}

4460MemInitResult
4461Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
                         Expr *Init, CXXRecordDecl *ClassDecl,
                         SourceLocation EllipsisLoc) {
SourceLocation BaseLoc
  = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();

if (!BaseType->isDependentType() && !BaseType->isRecordType())
  return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
           << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();

// C++ [class.base.init]p2:
//   [...] Unless the mem-initializer-id names a nonstatic data
//   member of the constructor's class or a direct or virtual base
//   of that class, the mem-initializer is ill-formed. A
//   mem-initializer-list can initialize a base class using any
//   name that denotes that base class type.
bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();

SourceRange InitRange = Init->getSourceRange();
if (EllipsisLoc.isValid()) {
  // This is a pack expansion.
  if (!BaseType->containsUnexpandedParameterPack())  {
    Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
      << SourceRange(BaseLoc, InitRange.getEnd());

    EllipsisLoc = SourceLocation();
  }
} else {
  // Check for any unexpanded parameter packs.
  if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
    return true;

  if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
    return true;
}

// Check for direct and virtual base classes.
const CXXBaseSpecifier *DirectBaseSpec = nullptr;
const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
if (!Dependent) {
  if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
                                     BaseType))
    return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);

  FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
                      VirtualBaseSpec);

  // C++ [base.class.init]p2:
  // Unless the mem-initializer-id names a nonstatic data member of the
  // constructor's class or a direct or virtual base of that class, the
  // mem-initializer is ill-formed.
  if (!DirectBaseSpec && !VirtualBaseSpec) {
    // If the class has any dependent bases, then it's possible that
    // one of those types will resolve to the same type as
    // BaseType. Therefore, just treat this as a dependent base
    // class initialization.  FIXME: Should we try to check the
    // initialization anyway? It seems odd.
    if (ClassDecl->hasAnyDependentBases())
      Dependent = true;
    else
      return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
        << BaseType << Context.getTypeDeclType(ClassDecl)
        << BaseTInfo->getTypeLoc().getLocalSourceRange();
  }
}

if (Dependent) {
  DiscardCleanupsInEvaluationContext();

  return new (Context) CXXCtorInitializer(Context, BaseTInfo,
                                          /*IsVirtual=*/false,
                                          InitRange.getBegin(), Init,
                                          InitRange.getEnd(), EllipsisLoc);
}

// C++ [base.class.init]p2:
//   If a mem-initializer-id is ambiguous because it designates both
//   a direct non-virtual base class and an inherited virtual base
//   class, the mem-initializer is ill-formed.
if (DirectBaseSpec && VirtualBaseSpec)
  return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
    << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();

const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
if (!BaseSpec)
  BaseSpec = VirtualBaseSpec;

// Initialize the base.
bool InitList = true;
MultiExprArg Args = Init;
if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
  InitList = false;
  Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
}

InitializedEntity BaseEntity =
  InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
InitializationKind Kind =
    InitList ? InitializationKind::CreateDirectList(BaseLoc)
             : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
                                                InitRange.getEnd());
InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
if (BaseInit.isInvalid())
  return true;

// C++11 [class.base.init]p7:
//   The initialization of each base and member constitutes a
//   full-expression.
BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
                               /*DiscardedValue*/ false);
if (BaseInit.isInvalid())
  return true;

// If we are in a dependent context, template instantiation will
// perform this type-checking again. Just save the arguments that we
// received in a ParenListExpr.
// FIXME: This isn't quite ideal, since our ASTs don't capture all
// of the information that we have about the base
// initializer. However, deconstructing the ASTs is a dicey process,
// and this approach is far more likely to get the corner cases right.
if (CurContext->isDependentContext())
  BaseInit = Init;

return new (Context) CXXCtorInitializer(Context, BaseTInfo,
                                        BaseSpec->isVirtual(),
                                        InitRange.getBegin(),
                                        BaseInit.getAs<Expr>(),
                                        InitRange.getEnd(), EllipsisLoc);
4590}

4592// Create a static_cast\<T&&>(expr).
4593static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
if (T.isNull()) T = E->getType();
QualType TargetType = SemaRef.BuildReferenceType(
    T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
SourceLocation ExprLoc = E->getBeginLoc();
TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
    TargetType, ExprLoc);

return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
                                 SourceRange(ExprLoc, ExprLoc),
                                 E->getSourceRange()).get();
4604}

4606/// ImplicitInitializerKind - How an implicit base or member initializer should
4607/// initialize its base or member.
4608enum ImplicitInitializerKind {
IIK_Default,
IIK_Copy,
IIK_Move,
IIK_Inherit
4613};

4615static bool
4616BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
                           ImplicitInitializerKind ImplicitInitKind,
                           CXXBaseSpecifier *BaseSpec,
                           bool IsInheritedVirtualBase,
                           CXXCtorInitializer *&CXXBaseInit) {
InitializedEntity InitEntity
  = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
                                      IsInheritedVirtualBase);

ExprResult BaseInit;

switch (ImplicitInitKind) {
case IIK_Inherit:
case IIK_Default: {
  InitializationKind InitKind
    = InitializationKind::CreateDefault(Constructor->getLocation());
  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
  break;
}

case IIK_Move:
case IIK_Copy: {
  bool Moving = ImplicitInitKind == IIK_Move;
  ParmVarDecl *Param = Constructor->getParamDecl(0);
  QualType ParamType = Param->getType().getNonReferenceType();

  Expr *CopyCtorArg =
    DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
                        SourceLocation(), Param, false,
                        Constructor->getLocation(), ParamType,
                        VK_LValue, nullptr);

  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));

  // Cast to the base class to avoid ambiguities.
  QualType ArgTy =
    SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
                                     ParamType.getQualifiers());

  if (Moving) {
    CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
  }

  CXXCastPath BasePath;
  BasePath.push_back(BaseSpec);
  CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
                                          CK_UncheckedDerivedToBase,
                                          Moving ? VK_XValue : VK_LValue,
                                          &BasePath).get();

  InitializationKind InitKind
    = InitializationKind::CreateDirect(Constructor->getLocation(),
                                       SourceLocation(), SourceLocation());
  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
  BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
  break;
}
}

BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
if (BaseInit.isInvalid())
  return true;

CXXBaseInit =
  new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
             SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
                                                      SourceLocation()),
                                           BaseSpec->isVirtual(),
                                           SourceLocation(),
                                           BaseInit.getAs<Expr>(),
                                           SourceLocation(),
                                           SourceLocation());

return false;
4691}

4693static bool RefersToRValueRef(Expr *MemRef) {
ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
return Referenced->getType()->isRValueReferenceType();
4696}

4698static bool
4699BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
                             ImplicitInitializerKind ImplicitInitKind,
                             FieldDecl *Field, IndirectFieldDecl *Indirect,
                             CXXCtorInitializer *&CXXMemberInit) {
if (Field->isInvalidDecl())
  return true;

SourceLocation Loc = Constructor->getLocation();

if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
  bool Moving = ImplicitInitKind == IIK_Move;
  ParmVarDecl *Param = Constructor->getParamDecl(0);
  QualType ParamType = Param->getType().getNonReferenceType();

  // Suppress copying zero-width bitfields.
  if (Field->isZeroLengthBitField(SemaRef.Context))
    return false;

  Expr *MemberExprBase =
    DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
                        SourceLocation(), Param, false,
                        Loc, ParamType, VK_LValue, nullptr);

  SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));

  if (Moving) {
    MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
  }

  // Build a reference to this field within the parameter.
  CXXScopeSpec SS;
  LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
                            Sema::LookupMemberName);
  MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
                                : cast<ValueDecl>(Field), AS_public);
  MemberLookup.resolveKind();
  ExprResult CtorArg
    = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
                                       ParamType, Loc,
                                       /*IsArrow=*/false,
                                       SS,
                                       /*TemplateKWLoc=*/SourceLocation(),
                                       /*FirstQualifierInScope=*/nullptr,
                                       MemberLookup,
                                       /*TemplateArgs=*/nullptr,
                                       /*S*/nullptr);
  if (CtorArg.isInvalid())
    return true;

  // C++11 [class.copy]p15:
  //   - if a member m has rvalue reference type T&&, it is direct-initialized
  //     with static_cast<T&&>(x.m);
  if (RefersToRValueRef(CtorArg.get())) {
    CtorArg = CastForMoving(SemaRef, CtorArg.get());
  }

  InitializedEntity Entity =
      Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
                                                     /*Implicit*/ true)
               : InitializedEntity::InitializeMember(Field, nullptr,
                                                     /*Implicit*/ true);

  // Direct-initialize to use the copy constructor.
  InitializationKind InitKind =
    InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());

  Expr *CtorArgE = CtorArg.getAs<Expr>();
  InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
  ExprResult MemberInit =
      InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
  if (MemberInit.isInvalid())
    return true;

  if (Indirect)
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
        SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
  else
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
        SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
  return false;
}

assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&((void)0)
       "Unhandled implicit init kind!")((void)0);

QualType FieldBaseElementType =
  SemaRef.Context.getBaseElementType(Field->getType());

if (FieldBaseElementType->isRecordType()) {
  InitializedEntity InitEntity =
      Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
                                                     /*Implicit*/ true)
               : InitializedEntity::InitializeMember(Field, nullptr,
                                                     /*Implicit*/ true);
  InitializationKind InitKind =
    InitializationKind::CreateDefault(Loc);

  InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
  ExprResult MemberInit =
    InitSeq.Perform(SemaRef, InitEntity, InitKind, None);

  MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
  if (MemberInit.isInvalid())
    return true;

  if (Indirect)
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
                                                             Indirect, Loc,
                                                             Loc,
                                                             MemberInit.get(),
                                                             Loc);
  else
    CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
                                                             Field, Loc, Loc,
                                                             MemberInit.get(),
                                                             Loc);
  return false;
}

if (!Field->getParent()->isUnion()) {
  if (FieldBaseElementType->isReferenceType()) {
    SemaRef.Diag(Constructor->getLocation(),
                 diag::err_uninitialized_member_in_ctor)
    << (int)Constructor->isImplicit()
    << SemaRef.Context.getTagDeclType(Constructor->getParent())
    << 0 << Field->getDeclName();
    SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
    return true;
  }

  if (FieldBaseElementType.isConstQualified()) {
    SemaRef.Diag(Constructor->getLocation(),
                 diag::err_uninitialized_member_in_ctor)
    << (int)Constructor->isImplicit()
    << SemaRef.Context.getTagDeclType(Constructor->getParent())
    << 1 << Field->getDeclName();
    SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
    return true;
  }
}

if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
  // ARC and Weak:
  //   Default-initialize Objective-C pointers to NULL.
  CXXMemberInit
    = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
                                               Loc, Loc,
               new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
                                               Loc);
  return false;
}

// Nothing to initialize.
CXXMemberInit = nullptr;
return false;
4855}

4857namespace {
4858struct BaseAndFieldInfo {
Sema &S;
CXXConstructorDecl *Ctor;
bool AnyErrorsInInits;
ImplicitInitializerKind IIK;
llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
SmallVector<CXXCtorInitializer*, 8> AllToInit;
llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;

BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
  : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
  bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
  if (Ctor->getInheritedConstructor())
    IIK = IIK_Inherit;
  else if (Generated && Ctor->isCopyConstructor())
    IIK = IIK_Copy;
  else if (Generated && Ctor->isMoveConstructor())
    IIK = IIK_Move;
  else
    IIK = IIK_Default;
}

bool isImplicitCopyOrMove() const {
  switch (IIK) {
  case IIK_Copy:
  case IIK_Move:
    return true;

  case IIK_Default:
  case IIK_Inherit:
    return false;
  }

  llvm_unreachable("Invalid ImplicitInitializerKind!")__builtin_unreachable();
}

bool addFieldInitializer(CXXCtorInitializer *Init) {
  AllToInit.push_back(Init);

  // Check whether this initializer makes the field "used".
  if (Init->getInit()->HasSideEffects(S.Context))
    S.UnusedPrivateFields.remove(Init->getAnyMember());

  return false;
}

bool isInactiveUnionMember(FieldDecl *Field) {
  RecordDecl *Record = Field->getParent();
  if (!Record->isUnion())
    return false;

  if (FieldDecl *Active =
          ActiveUnionMember.lookup(Record->getCanonicalDecl()))
    return Active != Field->getCanonicalDecl();

  // In an implicit copy or move constructor, ignore any in-class initializer.
  if (isImplicitCopyOrMove())
    return true;

  // If there's no explicit initialization, the field is active only if it
  // has an in-class initializer...
  if (Field->hasInClassInitializer())
    return false;
  // ... or it's an anonymous struct or union whose class has an in-class
  // initializer.
  if (!Field->isAnonymousStructOrUnion())
    return true;
  CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
  return !FieldRD->hasInClassInitializer();
}

/// Determine whether the given field is, or is within, a union member
/// that is inactive (because there was an initializer given for a different
/// member of the union, or because the union was not initialized at all).
bool isWithinInactiveUnionMember(FieldDecl *Field,
                                 IndirectFieldDecl *Indirect) {
  if (!Indirect)
    return isInactiveUnionMember(Field);

  for (auto *C : Indirect->chain()) {
    FieldDecl *Field = dyn_cast<FieldDecl>(C);
    if (Field && isInactiveUnionMember(Field))
      return true;
  }
  return false;
}
4944};
4945}

4947/// Determine whether the given type is an incomplete or zero-lenfgth
4948/// array type.
4949static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
if (T->isIncompleteArrayType())
  return true;

while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
  if (!ArrayT->getSize())
    return true;

  T = ArrayT->getElementType();
}

return false;
4961}

4963static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
                                  FieldDecl *Field,
                                  IndirectFieldDecl *Indirect = nullptr) {
if (Field->isInvalidDecl())
20
←
Assuming the condition is false→
21
←
Taking false branch→
  return false;

// Overwhelmingly common case: we have a direct initializer for this field.
if (CXXCtorInitializer *Init =
22
←
Assuming 'Init' is null→
23
←
Taking false branch→
        Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
  return Info.addFieldInitializer(Init);

// C++11 [class.base.init]p8:
//   if the entity is a non-static data member that has a
//   brace-or-equal-initializer and either
//   -- the constructor's class is a union and no other variant member of that
//      union is designated by a mem-initializer-id or
//   -- the constructor's class is not a union, and, if the entity is a member
//      of an anonymous union, no other member of that union is designated by
//      a mem-initializer-id,
//   the entity is initialized as specified in [dcl.init].
//
// We also apply the same rules to handle anonymous structs within anonymous
// unions.
if (Info.isWithinInactiveUnionMember(Field, Indirect))
24
←
Taking false branch→
  return false;

if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
25
←
Taking true branch→
  ExprResult DIE =
      SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
26
←
Calling 'Sema::BuildCXXDefaultInitExpr'→
  if (DIE.isInvalid())
    return true;

  auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
  SemaRef.checkInitializerLifetime(Entity, DIE.get());

  CXXCtorInitializer *Init;
  if (Indirect)
    Init = new (SemaRef.Context)
        CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
                           SourceLocation(), DIE.get(), SourceLocation());
  else
    Init = new (SemaRef.Context)
        CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
                           SourceLocation(), DIE.get(), SourceLocation());
  return Info.addFieldInitializer(Init);
}

// Don't initialize incomplete or zero-length arrays.
if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
  return false;

// Don't try to build an implicit initializer if there were semantic
// errors in any of the initializers (and therefore we might be
// missing some that the user actually wrote).
if (Info.AnyErrorsInInits)
  return false;

CXXCtorInitializer *Init = nullptr;
if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
                                   Indirect, Init))
  return true;

if (!Init)
  return false;

return Info.addFieldInitializer(Init);
5029}

5031bool
5032Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
                             CXXCtorInitializer *Initializer) {
assert(Initializer->isDelegatingInitializer())((void)0);
Constructor->setNumCtorInitializers(1);
CXXCtorInitializer **initializer =
  new (Context) CXXCtorInitializer*[1];
memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
Constructor->setCtorInitializers(initializer);

if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
  MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
  DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
}

DelegatingCtorDecls.push_back(Constructor);

DiagnoseUninitializedFields(*this, Constructor);

return false;
5051}

5053bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
                             ArrayRef<CXXCtorInitializer *> Initializers) {
if (Constructor->isDependentContext()) {
6
←
Assuming the condition is false→
7
←
Taking false branch→
  // Just store the initializers as written, they will be checked during
  // instantiation.
  if (!Initializers.empty()) {
    Constructor->setNumCtorInitializers(Initializers.size());
    CXXCtorInitializer **baseOrMemberInitializers =
      new (Context) CXXCtorInitializer*[Initializers.size()];
    memcpy(baseOrMemberInitializers, Initializers.data(),
           Initializers.size() * sizeof(CXXCtorInitializer*));
    Constructor->setCtorInitializers(baseOrMemberInitializers);
  }

  // Let template instantiation know whether we had errors.
  if (AnyErrors)
    Constructor->setInvalidDecl();

  return false;
}

BaseAndFieldInfo Info(*this, Constructor, AnyErrors);

// We need to build the initializer AST according to order of construction
// and not what user specified in the Initializers list.
CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
if (!ClassDecl)
8
←
Assuming 'ClassDecl' is non-null→
9
←
Taking false branch→
  return true;

bool HadError = false;

for (unsigned i = 0; i < Initializers.size(); i++) {
10
←
Assuming the condition is false→
11
←
Loop condition is false. Execution continues on line 5108→
  CXXCtorInitializer *Member = Initializers[i];

  if (Member->isBaseInitializer())
    Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
  else {
    Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;

    if (IndirectFieldDecl *F = Member->getIndirectMember()) {
      for (auto *C : F->chain()) {
        FieldDecl *FD = dyn_cast<FieldDecl>(C);
        if (FD && FD->getParent()->isUnion())
          Info.ActiveUnionMember.insert(std::make_pair(
              FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
      }
    } else if (FieldDecl *FD = Member->getMember()) {
      if (FD->getParent()->isUnion())
        Info.ActiveUnionMember.insert(std::make_pair(
            FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
    }
  }
}

// Keep track of the direct virtual bases.
llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
for (auto &I : ClassDecl->bases()) {
12
←
Assuming '__begin1' is equal to '__end1'→
  if (I.isVirtual())
    DirectVBases.insert(&I);
}

// Push virtual bases before others.
for (auto &VBase : ClassDecl->vbases()) {
13
←
Assuming '__begin1' is equal to '__end1'→
  if (CXXCtorInitializer *Value
      = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
    // [class.base.init]p7, per DR257:
    //   A mem-initializer where the mem-initializer-id names a virtual base
    //   class is ignored during execution of a constructor of any class that
    //   is not the most derived class.
    if (ClassDecl->isAbstract()) {
      // FIXME: Provide a fixit to remove the base specifier. This requires
      // tracking the location of the associated comma for a base specifier.
      Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
        << VBase.getType() << ClassDecl;
      DiagnoseAbstractType(ClassDecl);
    }

    Info.AllToInit.push_back(Value);
  } else if (!AnyErrors && !ClassDecl->isAbstract()) {
    // [class.base.init]p8, per DR257:
    //   If a given [...] base class is not named by a mem-initializer-id
    //   [...] and the entity is not a virtual base class of an abstract
    //   class, then [...] the entity is default-initialized.
    bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
    CXXCtorInitializer *CXXBaseInit;
    if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
                                     &VBase, IsInheritedVirtualBase,
                                     CXXBaseInit)) {
      HadError = true;
      continue;
    }

    Info.AllToInit.push_back(CXXBaseInit);
  }
}

// Non-virtual bases.
for (auto &Base : ClassDecl->bases()) {
14
←
Assuming '__begin1' is equal to '__end1'→
  // Virtuals are in the virtual base list and already constructed.
  if (Base.isVirtual())
    continue;

  if (CXXCtorInitializer *Value
        = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
    Info.AllToInit.push_back(Value);
  } else if (!AnyErrors) {
    CXXCtorInitializer *CXXBaseInit;
    if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
                                     &Base, /*IsInheritedVirtualBase=*/false,
                                     CXXBaseInit)) {
      HadError = true;
      continue;
    }

    Info.AllToInit.push_back(CXXBaseInit);
  }
}

// Fields.
for (auto *Mem : ClassDecl->decls()) {
  if (auto *F15.1
'F' is non-null
1
'F' is non-null
1
'F' is non-null
 = dyn_cast<FieldDecl>(Mem)) {
15
←
Assuming 'Mem' is a 'FieldDecl'→
16
←
Taking true branch→
    // C++ [class.bit]p2:
    //   A declaration for a bit-field that omits the identifier declares an
    //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
    //   initialized.
    if (F->isUnnamedBitfield())
17
←
Taking false branch→
      continue;

    // If we're not generating the implicit copy/move constructor, then we'll
    // handle anonymous struct/union fields based on their individual
    // indirect fields.
    if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
18
←
Assuming the condition is false→
      continue;

    if (CollectFieldInitializer(*this, Info, F))
19
←
Calling 'CollectFieldInitializer'→
      HadError = true;
    continue;
  }

  // Beyond this point, we only consider default initialization.
  if (Info.isImplicitCopyOrMove())
    continue;

  if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
    if (F->getType()->isIncompleteArrayType()) {
      assert(ClassDecl->hasFlexibleArrayMember() &&((void)0)
             "Incomplete array type is not valid")((void)0);
      continue;
    }

    // Initialize each field of an anonymous struct individually.
    if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
      HadError = true;

    continue;
  }
}

unsigned NumInitializers = Info.AllToInit.size();
if (NumInitializers > 0) {
  Constructor->setNumCtorInitializers(NumInitializers);
  CXXCtorInitializer **baseOrMemberInitializers =
    new (Context) CXXCtorInitializer*[NumInitializers];
  memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
         NumInitializers * sizeof(CXXCtorInitializer*));
  Constructor->setCtorInitializers(baseOrMemberInitializers);

  // Constructors implicitly reference the base and member
  // destructors.
  MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
                                         Constructor->getParent());
}

return HadError;
5227}

5229static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
  const RecordDecl *RD = RT->getDecl();
  if (RD->isAnonymousStructOrUnion()) {
    for (auto *Field : RD->fields())
      PopulateKeysForFields(Field, IdealInits);
    return;
  }
}
IdealInits.push_back(Field->getCanonicalDecl());
5239}

5241static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
return Context.getCanonicalType(BaseType).getTypePtr();
5243}

5245static const void *GetKeyForMember(ASTContext &Context,
                                 CXXCtorInitializer *Member) {
if (!Member->isAnyMemberInitializer())
  return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));

return Member->getAnyMember()->getCanonicalDecl();
5251}

5253static void AddInitializerToDiag(const Sema::SemaDiagnosticBuilder &Diag,
                               const CXXCtorInitializer *Previous,
                               const CXXCtorInitializer *Current) {
if (Previous->isAnyMemberInitializer())
  Diag << 0 << Previous->getAnyMember();
else
  Diag << 1 << Previous->getTypeSourceInfo()->getType();

if (Current->isAnyMemberInitializer())
  Diag << 0 << Current->getAnyMember();
else
  Diag << 1 << Current->getTypeSourceInfo()->getType();
5265}

5267static void DiagnoseBaseOrMemInitializerOrder(
  Sema &SemaRef, const CXXConstructorDecl *Constructor,
  ArrayRef<CXXCtorInitializer *> Inits) {
if (Constructor->getDeclContext()->isDependentContext())
  return;

// Don't check initializers order unless the warning is enabled at the
// location of at least one initializer.
bool ShouldCheckOrder = false;
for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
  CXXCtorInitializer *Init = Inits[InitIndex];
  if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
                               Init->getSourceLocation())) {
    ShouldCheckOrder = true;
    break;
  }
}
if (!ShouldCheckOrder)
  return;

// Build the list of bases and members in the order that they'll
// actually be initialized.  The explicit initializers should be in
// this same order but may be missing things.
SmallVector<const void*, 32> IdealInitKeys;

const CXXRecordDecl *ClassDecl = Constructor->getParent();

// 1. Virtual bases.
for (const auto &VBase : ClassDecl->vbases())
  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));

// 2. Non-virtual bases.
for (const auto &Base : ClassDecl->bases()) {
  if (Base.isVirtual())
    continue;
  IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
}

// 3. Direct fields.
for (auto *Field : ClassDecl->fields()) {
  if (Field->isUnnamedBitfield())
    continue;

  PopulateKeysForFields(Field, IdealInitKeys);
}

unsigned NumIdealInits = IdealInitKeys.size();
unsigned IdealIndex = 0;

// Track initializers that are in an incorrect order for either a warning or
// note if multiple ones occur.
SmallVector<unsigned> WarnIndexes;
// Correlates the index of an initializer in the init-list to the index of
// the field/base in the class.
SmallVector<std::pair<unsigned, unsigned>, 32> CorrelatedInitOrder;

for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
  const void *InitKey = GetKeyForMember(SemaRef.Context, Inits[InitIndex]);

  // Scan forward to try to find this initializer in the idealized
  // initializers list.
  for (; IdealIndex != NumIdealInits; ++IdealIndex)
    if (InitKey == IdealInitKeys[IdealIndex])
      break;

  // If we didn't find this initializer, it must be because we
  // scanned past it on a previous iteration.  That can only
  // happen if we're out of order;  emit a warning.
  if (IdealIndex == NumIdealInits && InitIndex) {
    WarnIndexes.push_back(InitIndex);

    // Move back to the initializer's location in the ideal list.
    for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
      if (InitKey == IdealInitKeys[IdealIndex])
        break;

    assert(IdealIndex < NumIdealInits &&((void)0)
           "initializer not found in initializer list")((void)0);
  }
  CorrelatedInitOrder.emplace_back(IdealIndex, InitIndex);
}

if (WarnIndexes.empty())
  return;

// Sort based on the ideal order, first in the pair.
llvm::sort(CorrelatedInitOrder,
           [](auto &LHS, auto &RHS) { return LHS.first < RHS.first; });

// Introduce a new scope as SemaDiagnosticBuilder needs to be destroyed to
// emit the diagnostic before we can try adding notes.
{
  Sema::SemaDiagnosticBuilder D = SemaRef.Diag(
      Inits[WarnIndexes.front() - 1]->getSourceLocation(),
      WarnIndexes.size() == 1 ? diag::warn_initializer_out_of_order
                              : diag::warn_some_initializers_out_of_order);

  for (unsigned I = 0; I < CorrelatedInitOrder.size(); ++I) {
    if (CorrelatedInitOrder[I].second == I)
      continue;
    // Ideally we would be using InsertFromRange here, but clang doesn't
    // appear to handle InsertFromRange correctly when the source range is
    // modified by another fix-it.
    D << FixItHint::CreateReplacement(
        Inits[I]->getSourceRange(),
        Lexer::getSourceText(
            CharSourceRange::getTokenRange(
                Inits[CorrelatedInitOrder[I].second]->getSourceRange()),
            SemaRef.getSourceManager(), SemaRef.getLangOpts()));
  }

  // If there is only 1 item out of order, the warning expects the name and
  // type of each being added to it.
  if (WarnIndexes.size() == 1) {
    AddInitializerToDiag(D, Inits[WarnIndexes.front() - 1],
                         Inits[WarnIndexes.front()]);
    return;
  }
}
// More than 1 item to warn, create notes letting the user know which ones
// are bad.
for (unsigned WarnIndex : WarnIndexes) {
  const clang::CXXCtorInitializer *PrevInit = Inits[WarnIndex - 1];
  auto D = SemaRef.Diag(PrevInit->getSourceLocation(),
                        diag::note_initializer_out_of_order);
  AddInitializerToDiag(D, PrevInit, Inits[WarnIndex]);
  D << PrevInit->getSourceRange();
}
5395}

5397namespace {
5398bool CheckRedundantInit(Sema &S,
                      CXXCtorInitializer *Init,
                      CXXCtorInitializer *&PrevInit) {
if (!PrevInit) {
  PrevInit = Init;
  return false;
}

if (FieldDecl *Field = Init->getAnyMember())
  S.Diag(Init->getSourceLocation(),
         diag::err_multiple_mem_initialization)
    << Field->getDeclName()
    << Init->getSourceRange();
else {
  const Type *BaseClass = Init->getBaseClass();
  assert(BaseClass && "neither field nor base")((void)0);
  S.Diag(Init->getSourceLocation(),
         diag::err_multiple_base_initialization)
    << QualType(BaseClass, 0)
    << Init->getSourceRange();
}
S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
  << 0 << PrevInit->getSourceRange();

return true;
5423}

5425typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5426typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;

5428bool CheckRedundantUnionInit(Sema &S,
                           CXXCtorInitializer *Init,
                           RedundantUnionMap &Unions) {
FieldDecl *Field = Init->getAnyMember();
RecordDecl *Parent = Field->getParent();
NamedDecl *Child = Field;

while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
  if (Parent->isUnion()) {
    UnionEntry &En = Unions[Parent];
    if (En.first && En.first != Child) {
      S.Diag(Init->getSourceLocation(),
             diag::err_multiple_mem_union_initialization)
        << Field->getDeclName()
        << Init->getSourceRange();
      S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
        << 0 << En.second->getSourceRange();
      return true;
    }
    if (!En.first) {
      En.first = Child;
      En.second = Init;
    }
    if (!Parent->isAnonymousStructOrUnion())
      return false;
  }

  Child = Parent;
  Parent = cast<RecordDecl>(Parent->getDeclContext());
}

return false;
5460}
5461} // namespace

5463/// ActOnMemInitializers - Handle the member initializers for a constructor.
5464void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
                              SourceLocation ColonLoc,
                              ArrayRef<CXXCtorInitializer*> MemInits,
                              bool AnyErrors) {
if (!ConstructorDecl)
  return;

AdjustDeclIfTemplate(ConstructorDecl);

CXXConstructorDecl *Constructor
  = dyn_cast<CXXConstructorDecl>(ConstructorDecl);

if (!Constructor) {
  Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
  return;
}

// Mapping for the duplicate initializers check.
// For member initializers, this is keyed with a FieldDecl*.
// For base initializers, this is keyed with a Type*.
llvm::DenseMap<const void *, CXXCtorInitializer *> Members;

// Mapping for the inconsistent anonymous-union initializers check.
RedundantUnionMap MemberUnions;

bool HadError = false;
for (unsigned i = 0; i < MemInits.size(); i++) {
  CXXCtorInitializer *Init = MemInits[i];

  // Set the source order index.
  Init->setSourceOrder(i);

  if (Init->isAnyMemberInitializer()) {
    const void *Key = GetKeyForMember(Context, Init);
    if (CheckRedundantInit(*this, Init, Members[Key]) ||
        CheckRedundantUnionInit(*this, Init, MemberUnions))
      HadError = true;
  } else if (Init->isBaseInitializer()) {
    const void *Key = GetKeyForMember(Context, Init);
    if (CheckRedundantInit(*this, Init, Members[Key]))
      HadError = true;
  } else {
    assert(Init->isDelegatingInitializer())((void)0);
    // This must be the only initializer
    if (MemInits.size() != 1) {
      Diag(Init->getSourceLocation(),
           diag::err_delegating_initializer_alone)
        << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
      // We will treat this as being the only initializer.
    }
    SetDelegatingInitializer(Constructor, MemInits[i]);
    // Return immediately as the initializer is set.
    return;
  }
}

if (HadError)
  return;

DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);

SetCtorInitializers(Constructor, AnyErrors, MemInits);

DiagnoseUninitializedFields(*this, Constructor);
5528}

5530void
5531Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
                                           CXXRecordDecl *ClassDecl) {
// Ignore dependent contexts. Also ignore unions, since their members never
// have destructors implicitly called.
if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
  return;

// FIXME: all the access-control diagnostics are positioned on the
// field/base declaration.  That's probably good; that said, the
// user might reasonably want to know why the destructor is being
// emitted, and we currently don't say.

// Non-static data members.
for (auto *Field : ClassDecl->fields()) {
  if (Field->isInvalidDecl())
    continue;

  // Don't destroy incomplete or zero-length arrays.
  if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
    continue;

  QualType FieldType = Context.getBaseElementType(Field->getType());

  const RecordType* RT = FieldType->getAs<RecordType>();
  if (!RT)
    continue;

  CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  if (FieldClassDecl->isInvalidDecl())
    continue;
  if (FieldClassDecl->hasIrrelevantDestructor())
    continue;
  // The destructor for an implicit anonymous union member is never invoked.
  if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
  assert(Dtor && "No dtor found for FieldClassDecl!")((void)0);
  CheckDestructorAccess(Field->getLocation(), Dtor,
                        PDiag(diag::err_access_dtor_field)
                          << Field->getDeclName()
                          << FieldType);

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}

// We only potentially invoke the destructors of potentially constructed
// subobjects.
bool VisitVirtualBases = !ClassDecl->isAbstract();

// If the destructor exists and has already been marked used in the MS ABI,
// then virtual base destructors have already been checked and marked used.
// Skip checking them again to avoid duplicate diagnostics.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
  CXXDestructorDecl *Dtor = ClassDecl->getDestructor();
  if (Dtor && Dtor->isUsed())
    VisitVirtualBases = false;
}

llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;

// Bases.
for (const auto &Base : ClassDecl->bases()) {
  const RecordType *RT = Base.getType()->getAs<RecordType>();
  if (!RT)
    continue;

  // Remember direct virtual bases.
  if (Base.isVirtual()) {
    if (!VisitVirtualBases)
      continue;
    DirectVirtualBases.insert(RT);
  }

  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  // If our base class is invalid, we probably can't get its dtor anyway.
  if (BaseClassDecl->isInvalidDecl())
    continue;
  if (BaseClassDecl->hasIrrelevantDestructor())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
  assert(Dtor && "No dtor found for BaseClassDecl!")((void)0);

  // FIXME: caret should be on the start of the class name
  CheckDestructorAccess(Base.getBeginLoc(), Dtor,
                        PDiag(diag::err_access_dtor_base)
                            << Base.getType() << Base.getSourceRange(),
                        Context.getTypeDeclType(ClassDecl));

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}

if (VisitVirtualBases)
  MarkVirtualBaseDestructorsReferenced(Location, ClassDecl,
                                       &DirectVirtualBases);
5629}

5631void Sema::MarkVirtualBaseDestructorsReferenced(
  SourceLocation Location, CXXRecordDecl *ClassDecl,
  llvm::SmallPtrSetImpl<const RecordType *> *DirectVirtualBases) {
// Virtual bases.
for (const auto &VBase : ClassDecl->vbases()) {
  // Bases are always records in a well-formed non-dependent class.
  const RecordType *RT = VBase.getType()->castAs<RecordType>();

  // Ignore already visited direct virtual bases.
  if (DirectVirtualBases && DirectVirtualBases->count(RT))
    continue;

  CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
  // If our base class is invalid, we probably can't get its dtor anyway.
  if (BaseClassDecl->isInvalidDecl())
    continue;
  if (BaseClassDecl->hasIrrelevantDestructor())
    continue;

  CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
  assert(Dtor && "No dtor found for BaseClassDecl!")((void)0);
  if (CheckDestructorAccess(
          ClassDecl->getLocation(), Dtor,
          PDiag(diag::err_access_dtor_vbase)
              << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
          Context.getTypeDeclType(ClassDecl)) ==
      AR_accessible) {
    CheckDerivedToBaseConversion(
        Context.getTypeDeclType(ClassDecl), VBase.getType(),
        diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
        SourceRange(), DeclarationName(), nullptr);
  }

  MarkFunctionReferenced(Location, Dtor);
  DiagnoseUseOfDecl(Dtor, Location);
}
5667}

5669void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
if (!CDtorDecl)
1
Assuming 'CDtorDecl' is non-null→
2
←
Taking false branch→
  return;

if (CXXConstructorDecl *Constructor3.1
'Constructor' is non-null
1
'Constructor' is non-null

3.1	'Constructor' is non-null

←

Taking true branch

→

5674 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {

←

Assuming 'CDtorDecl' is a 'CXXConstructorDecl'

→

5675 SetCtorInitializers(Constructor, /*AnyErrors=*/false);

←

Calling 'Sema::SetCtorInitializers'

→

5676 DiagnoseUninitializedFields(*this, Constructor); 5677 } 5678} 5679 5680bool Sema::isAbstractType(SourceLocation Loc, QualType T) { 5681 if (!getLangOpts().CPlusPlus) 5682 return false; 5683 5684 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl(); 5685 if (!RD) 5686 return false; 5687 5688 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a 5689 // class template specialization here, but doing so breaks a lot of code. 5690 5691 // We can't answer whether something is abstract until it has a 5692 // definition. If it's currently being defined, we'll walk back 5693 // over all the declarations when we have a full definition. 5694 const CXXRecordDecl *Def = RD->getDefinition(); 5695 if (!Def || Def->isBeingDefined()) 5696 return false; 5697 5698 return RD->isAbstract(); 5699} 5700 5701bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T, 5702 TypeDiagnoser &Diagnoser) { 5703 if (!isAbstractType(Loc, T)) 5704 return false; 5705 5706 T = Context.getBaseElementType(T); 5707 Diagnoser.diagnose(*this, Loc, T); 5708 DiagnoseAbstractType(T->getAsCXXRecordDecl()); 5709 return true; 5710} 5711 5712void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) { 5713 // Check if we've already emitted the list of pure virtual functions 5714 // for this class. 5715 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD)) 5716 return; 5717 5718 // If the diagnostic is suppressed, don't emit the notes. We're only 5719 // going to emit them once, so try to attach them to a diagnostic we're 5720 // actually going to show. 5721 if (Diags.isLastDiagnosticIgnored()) 5722 return; 5723 5724 CXXFinalOverriderMap FinalOverriders; 5725 RD->getFinalOverriders(FinalOverriders); 5726 5727 // Keep a set of seen pure methods so we won't diagnose the same method 5728 // more than once. 5729 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods; 5730 5731 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(), 5732 MEnd = FinalOverriders.end(); 5733 M != MEnd; 5734 ++M) { 5735 for (OverridingMethods::iterator SO = M->second.begin(), 5736 SOEnd = M->second.end(); 5737 SO != SOEnd; ++SO) { 5738 // C++ [class.abstract]p4: 5739 // A class is abstract if it contains or inherits at least one 5740 // pure virtual function for which the final overrider is pure 5741 // virtual. 5742 5743 // 5744 if (SO->second.size() != 1) 5745 continue; 5746 5747 if (!SO->second.front().Method->isPure()) 5748 continue; 5749 5750 if (!SeenPureMethods.insert(SO->second.front().Method).second) 5751 continue; 5752 5753 Diag(SO->second.front().Method->getLocation(), 5754 diag::note_pure_virtual_function) 5755 << SO->second.front().Method->getDeclName() << RD->getDeclName(); 5756 } 5757 } 5758 5759 if (!PureVirtualClassDiagSet) 5760 PureVirtualClassDiagSet.reset(new RecordDeclSetTy); 5761 PureVirtualClassDiagSet->insert(RD); 5762} 5763 5764namespace { 5765struct AbstractUsageInfo { 5766 Sema &S; 5767 CXXRecordDecl *Record; 5768 CanQualType AbstractType; 5769 bool Invalid; 5770 5771 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record) 5772 : S(S), Record(Record), 5773 AbstractType(S.Context.getCanonicalType( 5774 S.Context.getTypeDeclType(Record))), 5775 Invalid(false) {} 5776 5777 void DiagnoseAbstractType() { 5778 if (Invalid) return; 5779 S.DiagnoseAbstractType(Record); 5780 Invalid = true; 5781 } 5782 5783 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel); 5784}; 5785 5786struct CheckAbstractUsage { 5787 AbstractUsageInfo &Info; 5788 const NamedDecl *Ctx; 5789 5790 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx) 5791 : Info(Info), Ctx(Ctx) {} 5792 5793 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) { 5794 switch (TL.getTypeLocClass()) { 5795#define ABSTRACT_TYPELOC(CLASS, PARENT) 5796#define TYPELOC(CLASS, PARENT) \ 5797 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break; 5798#include "clang/AST/TypeLocNodes.def" 5799 } 5800 } 5801 5802 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) { 5803 Visit(TL.getReturnLoc(), Sema::AbstractReturnType); 5804 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) { 5805 if (!TL.getParam(I)) 5806 continue; 5807 5808 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo(); 5809 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType); 5810 } 5811 } 5812 5813 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) { 5814 Visit(TL.getElementLoc(), Sema::AbstractArrayType); 5815 } 5816 5817 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) { 5818 // Visit the type parameters from a permissive context. 5819 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) { 5820 TemplateArgumentLoc TAL = TL.getArgLoc(I); 5821 if (TAL.getArgument().getKind() == TemplateArgument::Type) 5822 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo()) 5823 Visit(TSI->getTypeLoc(), Sema::AbstractNone); 5824 // TODO: other template argument types? 5825 } 5826 } 5827 5828 // Visit pointee types from a permissive context. 5829#define CheckPolymorphic(Type)void Check(Type TL, Sema::AbstractDiagSelID Sel) { Visit(TL.getNextTypeLoc
(), Sema::AbstractNone); } \ 5830 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \ 5831 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \ 5832 } 5833 CheckPolymorphic(PointerTypeLoc)void Check(PointerTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); } 5834 CheckPolymorphic(ReferenceTypeLoc)void Check(ReferenceTypeLoc TL, Sema::AbstractDiagSelID Sel) {
Visit(TL.getNextTypeLoc(), Sema::AbstractNone); } 5835 CheckPolymorphic(MemberPointerTypeLoc)void Check(MemberPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); } 5836 CheckPolymorphic(BlockPointerTypeLoc)void Check(BlockPointerTypeLoc TL, Sema::AbstractDiagSelID Sel
) { Visit(TL.getNextTypeLoc(), Sema::AbstractNone); } 5837 CheckPolymorphic(AtomicTypeLoc)void Check(AtomicTypeLoc TL, Sema::AbstractDiagSelID Sel) { Visit
(TL.getNextTypeLoc(), Sema::AbstractNone); } 5838 5839 /// Handle all the types we haven't given a more specific 5840 /// implementation for above. 5841 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) { 5842 // Every other kind of type that we haven't called out already 5843 // that has an inner type is either (1) sugar or (2) contains that 5844 // inner type in some way as a subobject. 5845 if (TypeLoc Next = TL.getNextTypeLoc()) 5846 return Visit(Next, Sel); 5847 5848 // If there's no inner type and we're in a permissive context, 5849 // don't diagnose. 5850 if (Sel == Sema::AbstractNone) return; 5851 5852 // Check whether the type matches the abstract type. 5853 QualType T = TL.getType(); 5854 if (T->isArrayType()) { 5855 Sel = Sema::AbstractArrayType; 5856 T = Info.S.Context.getBaseElementType(T); 5857 } 5858 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType(); 5859 if (CT != Info.AbstractType) return; 5860 5861 // It matched; do some magic. 5862 if (Sel == Sema::AbstractArrayType) { 5863 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type) 5864 << T << TL.getSourceRange(); 5865 } else { 5866 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl) 5867 << Sel << T << TL.getSourceRange(); 5868 } 5869 Info.DiagnoseAbstractType(); 5870 } 5871}; 5872 5873void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL, 5874 Sema::AbstractDiagSelID Sel) { 5875 CheckAbstractUsage(*this, D).Visit(TL, Sel); 5876} 5877 5878} 5879 5880/// Check for invalid uses of an abstract type in a method declaration. 5881static void CheckAbstractClassUsage(AbstractUsageInfo &Info, 5882 CXXMethodDecl *MD) { 5883 // No need to do the check on definitions, which require that 5884 // the return/param types be complete. 5885 if (MD->doesThisDeclarationHaveABody()) 5886 return; 5887 5888 // For safety's sake, just ignore it if we don't have type source 5889 // information. This should never happen for non-implicit methods, 5890 // but... 5891 if (TypeSourceInfo *TSI = MD->getTypeSourceInfo()) 5892 Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone); 5893} 5894 5895/// Check for invalid uses of an abstract type within a class definition. 5896static void CheckAbstractClassUsage(AbstractUsageInfo &Info, 5897 CXXRecordDecl *RD) { 5898 for (auto *D : RD->decls()) { 5899 if (D->isImplicit()) continue; 5900 5901 // Methods and method templates. 5902 if (isa<CXXMethodDecl>(D)) { 5903 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D)); 5904 } else if (isa<FunctionTemplateDecl>(D)) { 5905 FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl(); 5906 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD)); 5907 5908 // Fields and static variables. 5909 } else if (isa<FieldDecl>(D)) { 5910 FieldDecl *FD = cast<FieldDecl>(D); 5911 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo()) 5912 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType); 5913 } else if (isa<VarDecl>(D)) { 5914 VarDecl *VD = cast<VarDecl>(D); 5915 if (TypeSourceInfo *TSI = VD->getTypeSourceInfo()) 5916 Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType); 5917 5918 // Nested classes and class templates. 5919 } else if (isa<CXXRecordDecl>(D)) { 5920 CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D)); 5921 } else if (isa<ClassTemplateDecl>(D)) { 5922 CheckAbstractClassUsage(Info, 5923 cast<ClassTemplateDecl>(D)->getTemplatedDecl()); 5924 } 5925 } 5926} 5927 5928static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) { 5929 Attr *ClassAttr = getDLLAttr(Class); 5930 if (!ClassAttr) 5931 return; 5932 5933 assert(ClassAttr->getKind() == attr::DLLExport)((void)0); 5934 5935 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); 5936 5937 if (TSK == TSK_ExplicitInstantiationDeclaration) 5938 // Don't go any further if this is just an explicit instantiation 5939 // declaration. 5940 return; 5941 5942 // Add a context note to explain how we got to any diagnostics produced below. 5943 struct MarkingClassDllexported { 5944 Sema &S; 5945 MarkingClassDllexported(Sema &S, CXXRecordDecl *Class, 5946 SourceLocation AttrLoc) 5947 : S(S) { 5948 Sema::CodeSynthesisContext Ctx; 5949 Ctx.Kind = Sema::CodeSynthesisContext::MarkingClassDllexported; 5950 Ctx.PointOfInstantiation = AttrLoc; 5951 Ctx.Entity = Class; 5952 S.pushCodeSynthesisContext(Ctx); 5953 } 5954 ~MarkingClassDllexported() { 5955 S.popCodeSynthesisContext(); 5956 } 5957 } MarkingDllexportedContext(S, Class, ClassAttr->getLocation()); 5958 5959 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) 5960 S.MarkVTableUsed(Class->getLocation(), Class, true); 5961 5962 for (Decl *Member : Class->decls()) { 5963 // Defined static variables that are members of an exported base 5964 // class must be marked export too. 5965 auto *VD = dyn_cast<VarDecl>(Member); 5966 if (VD && Member->getAttr<DLLExportAttr>() && 5967 VD->getStorageClass() == SC_Static && 5968 TSK == TSK_ImplicitInstantiation) 5969 S.MarkVariableReferenced(VD->getLocation(), VD); 5970 5971 auto *MD = dyn_cast<CXXMethodDecl>(Member); 5972 if (!MD) 5973 continue; 5974 5975 if (Member->getAttr<DLLExportAttr>()) { 5976 if (MD->isUserProvided()) { 5977 // Instantiate non-default class member functions ... 5978 5979 // .. except for certain kinds of template specializations. 5980 if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited()) 5981 continue; 5982 5983 S.MarkFunctionReferenced(Class->getLocation(), MD); 5984 5985 // The function will be passed to the consumer when its definition is 5986 // encountered. 5987 } else if (MD->isExplicitlyDefaulted()) { 5988 // Synthesize and instantiate explicitly defaulted methods. 5989 S.MarkFunctionReferenced(Class->getLocation(), MD); 5990 5991 if (TSK != TSK_ExplicitInstantiationDefinition) { 5992 // Except for explicit instantiation defs, we will not see the 5993 // definition again later, so pass it to the consumer now. 5994 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD)); 5995 } 5996 } else if (!MD->isTrivial() || 5997 MD->isCopyAssignmentOperator() || 5998 MD->isMoveAssignmentOperator()) { 5999 // Synthesize and instantiate non-trivial implicit methods, and the copy 6000 // and move assignment operators. The latter are exported even if they 6001 // are trivial, because the address of an operator can be taken and 6002 // should compare equal across libraries. 6003 S.MarkFunctionReferenced(Class->getLocation(), MD); 6004 6005 // There is no later point when we will see the definition of this 6006 // function, so pass it to the consumer now. 6007 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD)); 6008 } 6009 } 6010 } 6011} 6012 6013static void checkForMultipleExportedDefaultConstructors(Sema &S, 6014 CXXRecordDecl *Class) { 6015 // Only the MS ABI has default constructor closures, so we don't need to do 6016 // this semantic checking anywhere else. 6017 if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft()) 6018 return; 6019 6020 CXXConstructorDecl *LastExportedDefaultCtor = nullptr; 6021 for (Decl *Member : Class->decls()) { 6022 // Look for exported default constructors. 6023 auto *CD = dyn_cast<CXXConstructorDecl>(Member); 6024 if (!CD || !CD->isDefaultConstructor()) 6025 continue; 6026 auto *Attr = CD->getAttr<DLLExportAttr>(); 6027 if (!Attr) 6028 continue; 6029 6030 // If the class is non-dependent, mark the default arguments as ODR-used so 6031 // that we can properly codegen the constructor closure. 6032 if (!Class->isDependentContext()) { 6033 for (ParmVarDecl *PD : CD->parameters()) { 6034 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD); 6035 S.DiscardCleanupsInEvaluationContext(); 6036 } 6037 } 6038 6039 if (LastExportedDefaultCtor) { 6040 S.Diag(LastExportedDefaultCtor->getLocation(), 6041 diag::err_attribute_dll_ambiguous_default_ctor) 6042 << Class; 6043 S.Diag(CD->getLocation(), diag::note_entity_declared_at) 6044 << CD->getDeclName(); 6045 return; 6046 } 6047 LastExportedDefaultCtor = CD; 6048 } 6049} 6050 6051static void checkCUDADeviceBuiltinSurfaceClassTemplate(Sema &S, 6052 CXXRecordDecl *Class) { 6053 bool ErrorReported = false; 6054 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S, 6055 ClassTemplateDecl *TD) { 6056 if (ErrorReported) 6057 return; 6058 S.Diag(TD->getLocation(), 6059 diag::err_cuda_device_builtin_surftex_cls_template) 6060 << /*surface*/ 0 << TD; 6061 ErrorReported = true; 6062 }; 6063 6064 ClassTemplateDecl *TD = Class->getDescribedClassTemplate(); 6065 if (!TD) { 6066 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class); 6067 if (!SD) { 6068 S.Diag(Class->getLocation(), 6069 diag::err_cuda_device_builtin_surftex_ref_decl) 6070 << /*surface*/ 0 << Class; 6071 S.Diag(Class->getLocation(), 6072 diag::note_cuda_device_builtin_surftex_should_be_template_class) 6073 << Class; 6074 return; 6075 } 6076 TD = SD->getSpecializedTemplate(); 6077 } 6078 6079 TemplateParameterList *Params = TD->getTemplateParameters(); 6080 unsigned N = Params->size(); 6081 6082 if (N != 2) { 6083 reportIllegalClassTemplate(S, TD); 6084 S.Diag(TD->getLocation(), 6085 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args) 6086 << TD << 2; 6087 } 6088 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) { 6089 reportIllegalClassTemplate(S, TD); 6090 S.Diag(TD->getLocation(), 6091 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) 6092 << TD << /*1st*/ 0 << /*type*/ 0; 6093 } 6094 if (N > 1) { 6095 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1)); 6096 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { 6097 reportIllegalClassTemplate(S, TD); 6098 S.Diag(TD->getLocation(), 6099 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) 6100 << TD << /*2nd*/ 1 << /*integer*/ 1; 6101 } 6102 } 6103} 6104 6105static void checkCUDADeviceBuiltinTextureClassTemplate(Sema &S, 6106 CXXRecordDecl *Class) { 6107 bool ErrorReported = false; 6108 auto reportIllegalClassTemplate = [&ErrorReported](Sema &S, 6109 ClassTemplateDecl *TD) { 6110 if (ErrorReported) 6111 return; 6112 S.Diag(TD->getLocation(), 6113 diag::err_cuda_device_builtin_surftex_cls_template) 6114 << /*texture*/ 1 << TD; 6115 ErrorReported = true; 6116 }; 6117 6118 ClassTemplateDecl *TD = Class->getDescribedClassTemplate(); 6119 if (!TD) { 6120 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(Class); 6121 if (!SD) { 6122 S.Diag(Class->getLocation(), 6123 diag::err_cuda_device_builtin_surftex_ref_decl) 6124 << /*texture*/ 1 << Class; 6125 S.Diag(Class->getLocation(), 6126 diag::note_cuda_device_builtin_surftex_should_be_template_class) 6127 << Class; 6128 return; 6129 } 6130 TD = SD->getSpecializedTemplate(); 6131 } 6132 6133 TemplateParameterList *Params = TD->getTemplateParameters(); 6134 unsigned N = Params->size(); 6135 6136 if (N != 3) { 6137 reportIllegalClassTemplate(S, TD); 6138 S.Diag(TD->getLocation(), 6139 diag::note_cuda_device_builtin_surftex_cls_should_have_n_args) 6140 << TD << 3; 6141 } 6142 if (N > 0 && !isa<TemplateTypeParmDecl>(Params->getParam(0))) { 6143 reportIllegalClassTemplate(S, TD); 6144 S.Diag(TD->getLocation(), 6145 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) 6146 << TD << /*1st*/ 0 << /*type*/ 0; 6147 } 6148 if (N > 1) { 6149 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(1)); 6150 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { 6151 reportIllegalClassTemplate(S, TD); 6152 S.Diag(TD->getLocation(), 6153 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) 6154 << TD << /*2nd*/ 1 << /*integer*/ 1; 6155 } 6156 } 6157 if (N > 2) { 6158 auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(2)); 6159 if (!NTTP || !NTTP->getType()->isIntegralOrEnumerationType()) { 6160 reportIllegalClassTemplate(S, TD); 6161 S.Diag(TD->getLocation(), 6162 diag::note_cuda_device_builtin_surftex_cls_should_have_match_arg) 6163 << TD << /*3rd*/ 2 << /*integer*/ 1; 6164 } 6165 } 6166} 6167 6168void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) { 6169 // Mark any compiler-generated routines with the implicit code_seg attribute. 6170 for (auto *Method : Class->methods()) { 6171 if (Method->isUserProvided()) 6172 continue; 6173 if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true)) 6174 Method->addAttr(A); 6175 } 6176} 6177 6178/// Check class-level dllimport/dllexport attribute. 6179void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) { 6180 Attr *ClassAttr = getDLLAttr(Class); 6181 6182 // MSVC inherits DLL attributes to partial class template specializations. 6183 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && !ClassAttr) { 6184 if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) { 6185 if (Attr *TemplateAttr = 6186 getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) { 6187 auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext())); 6188 A->setInherited(true); 6189 ClassAttr = A; 6190 } 6191 } 6192 } 6193 6194 if (!ClassAttr) 6195 return; 6196 6197 if (!Class->isExternallyVisible()) { 6198 Diag(Class->getLocation(), diag::err_attribute_dll_not_extern) 6199 << Class << ClassAttr; 6200 return; 6201 } 6202 6203 if (Context.getTargetInfo().shouldDLLImportComdatSymbols() && 6204 !ClassAttr->isInherited()) { 6205 // Diagnose dll attributes on members of class with dll attribute. 6206 for (Decl *Member : Class->decls()) { 6207 if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member)) 6208 continue; 6209 InheritableAttr *MemberAttr = getDLLAttr(Member); 6210 if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl()) 6211 continue; 6212 6213 Diag(MemberAttr->getLocation(), 6214 diag::err_attribute_dll_member_of_dll_class) 6215 << MemberAttr << ClassAttr; 6216 Diag(ClassAttr->getLocation(), diag::note_previous_attribute); 6217 Member->setInvalidDecl(); 6218 } 6219 } 6220 6221 if (Class->getDescribedClassTemplate()) 6222 // Don't inherit dll attribute until the template is instantiated. 6223 return; 6224 6225 // The class is either imported or exported. 6226 const bool ClassExported = ClassAttr->getKind() == attr::DLLExport; 6227 6228 // Check if this was a dllimport attribute propagated from a derived class to 6229 // a base class template specialization. We don't apply these attributes to 6230 // static data members. 6231 const bool PropagatedImport = 6232 !ClassExported && 6233 cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate(); 6234 6235 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind(); 6236 6237 // Ignore explicit dllexport on explicit class template instantiation 6238 // declarations, except in MinGW mode. 6239 if (ClassExported && !ClassAttr->isInherited() && 6240 TSK == TSK_ExplicitInstantiationDeclaration && 6241 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) { 6242 Class->dropAttr<DLLExportAttr>(); 6243 return; 6244 } 6245 6246 // Force declaration of implicit members so they can inherit the attribute. 6247 ForceDeclarationOfImplicitMembers(Class); 6248 6249 // FIXME: MSVC's docs say all bases must be exportable, but this doesn't 6250 // seem to be true in practice? 6251 6252 for (Decl *Member : Class->decls()) { 6253 VarDecl *VD = dyn_cast<VarDecl>(Member); 6254 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member); 6255 6256 // Only methods and static fields inherit the attributes. 6257 if (!VD && !MD) 6258 continue; 6259 6260 if (MD) { 6261 // Don't process deleted methods. 6262 if (MD->isDeleted()) 6263 continue; 6264 6265 if (MD->isInlined()) { 6266 // MinGW does not import or export inline methods. But do it for 6267 // template instantiations. 6268 if (!Context.getTargetInfo().shouldDLLImportComdatSymbols() && 6269 TSK != TSK_ExplicitInstantiationDeclaration && 6270 TSK != TSK_ExplicitInstantiationDefinition) 6271 continue; 6272 6273 // MSVC versions before 2015 don't export the move assignment operators 6274 // and move constructor, so don't attempt to import/export them if 6275 // we have a definition. 6276 auto *Ctor = dyn_cast<CXXConstructorDecl>(MD); 6277 if ((MD->isMoveAssignmentOperator() || 6278 (Ctor && Ctor->isMoveConstructor())) && 6279 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015)) 6280 continue; 6281 6282 // MSVC2015 doesn't export trivial defaulted x-tor but copy assign 6283 // operator is exported anyway. 6284 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) && 6285 (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial()) 6286 continue; 6287 } 6288 } 6289 6290 // Don't apply dllimport attributes to static data members of class template 6291 // instantiations when the attribute is propagated from a derived class. 6292 if (VD && PropagatedImport) 6293 continue; 6294 6295 if (!cast<NamedDecl>(Member)->isExternallyVisible()) 6296 continue; 6297 6298 if (!getDLLAttr(Member)) { 6299 InheritableAttr *NewAttr = nullptr; 6300 6301 // Do not export/import inline function when -fno-dllexport-inlines is 6302 // passed. But add attribute for later local static var check. 6303 if (!getLangOpts().DllExportInlines && MD && MD->isInlined() && 6304 TSK != TSK_ExplicitInstantiationDeclaration && 6305 TSK != TSK_ExplicitInstantiationDefinition) { 6306 if (ClassExported) { 6307 NewAttr = ::new (getASTContext()) 6308 DLLExportStaticLocalAttr(getASTContext(), *ClassAttr); 6309 } else { 6310 NewAttr = ::new (getASTContext()) 6311 DLLImportStaticLocalAttr(getASTContext(), *ClassAttr); 6312 } 6313 } else { 6314 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext())); 6315 } 6316 6317 NewAttr->setInherited(true); 6318 Member->addAttr(NewAttr); 6319 6320 if (MD) { 6321 // Propagate DLLAttr to friend re-declarations of MD that have already 6322 // been constructed. 6323 for (FunctionDecl *FD = MD->getMostRecentDecl(); FD; 6324 FD = FD->getPreviousDecl()) { 6325 if (FD->getFriendObjectKind() == Decl::FOK_None) 6326 continue; 6327 assert(!getDLLAttr(FD) &&((void)0) 6328 "friend re-decl should not already have a DLLAttr")((void)0); 6329 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext())); 6330 NewAttr->setInherited(true); 6331 FD->addAttr(NewAttr); 6332 } 6333 } 6334 } 6335 } 6336 6337 if (ClassExported) 6338 DelayedDllExportClasses.push_back(Class); 6339} 6340 6341/// Perform propagation of DLL attributes from a derived class to a 6342/// templated base class for MS compatibility. 6343void Sema::propagateDLLAttrToBaseClassTemplate( 6344 CXXRecordDecl *Class, Attr *ClassAttr, 6345 ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) { 6346 if (getDLLAttr( 6347 BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) { 6348 // If the base class template has a DLL attribute, don't try to change it. 6349 return; 6350 } 6351 6352 auto TSK = BaseTemplateSpec->getSpecializationKind(); 6353 if (!getDLLAttr(BaseTemplateSpec) && 6354 (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration || 6355 TSK == TSK_ImplicitInstantiation)) { 6356 // The template hasn't been instantiated yet (or it has, but only as an 6357 // explicit instantiation declaration or implicit instantiation, which means 6358 // we haven't codegenned any members yet), so propagate the attribute. 6359 auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext())); 6360 NewAttr->setInherited(true); 6361 BaseTemplateSpec->addAttr(NewAttr); 6362 6363 // If this was an import, mark that we propagated it from a derived class to 6364 // a base class template specialization. 6365 if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr)) 6366 ImportAttr->setPropagatedToBaseTemplate(); 6367 6368 // If the template is already instantiated, checkDLLAttributeRedeclaration() 6369 // needs to be run again to work see the new attribute. Otherwise this will 6370 // get run whenever the template is instantiated. 6371 if (TSK != TSK_Undeclared) 6372 checkClassLevelDLLAttribute(BaseTemplateSpec); 6373 6374 return; 6375 } 6376 6377 if (getDLLAttr(BaseTemplateSpec)) { 6378 // The template has already been specialized or instantiated with an 6379 // attribute, explicitly or through propagation. We should not try to change 6380 // it. 6381 return; 6382 } 6383 6384 // The template was previously instantiated or explicitly specialized without 6385 // a dll attribute, It's too late for us to add an attribute, so warn that 6386 // this is unsupported. 6387 Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class) 6388 << BaseTemplateSpec->isExplicitSpecialization(); 6389 Diag(ClassAttr->getLocation(), diag::note_attribute); 6390 if (BaseTemplateSpec->isExplicitSpecialization()) { 6391 Diag(BaseTemplateSpec->getLocation(), 6392 diag::note_template_class_explicit_specialization_was_here) 6393 << BaseTemplateSpec; 6394 } else { 6395 Diag(BaseTemplateSpec->getPointOfInstantiation(), 6396 diag::note_template_class_instantiation_was_here) 6397 << BaseTemplateSpec; 6398 } 6399} 6400 6401/// Determine the kind of defaulting that would be done for a given function. 6402/// 6403/// If the function is both a default constructor and a copy / move constructor 6404/// (due to having a default argument for the first parameter), this picks 6405/// CXXDefaultConstructor. 6406/// 6407/// FIXME: Check that case is properly handled by all callers. 6408Sema::DefaultedFunctionKind 6409Sema::getDefaultedFunctionKind(const FunctionDecl *FD) { 6410 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) { 6411 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) { 6412 if (Ctor->isDefaultConstructor()) 6413 return Sema::CXXDefaultConstructor; 6414 6415 if (Ctor->isCopyConstructor()) 6416 return Sema::CXXCopyConstructor; 6417 6418 if (Ctor->isMoveConstructor()) 6419 return Sema::CXXMoveConstructor; 6420 } 6421 6422 if (MD->isCopyAssignmentOperator()) 6423 return Sema::CXXCopyAssignment; 6424 6425 if (MD->isMoveAssignmentOperator()) 6426 return Sema::CXXMoveAssignment; 6427 6428 if (isa<CXXDestructorDecl>(FD)) 6429 return Sema::CXXDestructor; 6430 } 6431 6432 switch (FD->getDeclName().getCXXOverloadedOperator()) { 6433 case OO_EqualEqual: 6434 return DefaultedComparisonKind::Equal; 6435 6436 case OO_ExclaimEqual: 6437 return DefaultedComparisonKind::NotEqual; 6438 6439 case OO_Spaceship: 6440 // No point allowing this if <=> doesn't exist in the current language mode. 6441 if (!getLangOpts().CPlusPlus20) 6442 break; 6443 return DefaultedComparisonKind::ThreeWay; 6444 6445 case OO_Less: 6446 case OO_LessEqual: 6447 case OO_Greater: 6448 case OO_GreaterEqual: 6449 // No point allowing this if <=> doesn't exist in the current language mode. 6450 if (!getLangOpts().CPlusPlus20) 6451 break; 6452 return DefaultedComparisonKind::Relational; 6453 6454 default: 6455 break; 6456 } 6457 6458 // Not defaultable. 6459 return DefaultedFunctionKind(); 6460} 6461 6462static void DefineDefaultedFunction(Sema &S, FunctionDecl *FD, 6463 SourceLocation DefaultLoc) { 6464 Sema::DefaultedFunctionKind DFK = S.getDefaultedFunctionKind(FD); 6465 if (DFK.isComparison()) 6466 return S.DefineDefaultedComparison(DefaultLoc, FD, DFK.asComparison()); 6467 6468 switch (DFK.asSpecialMember()) { 6469 case Sema::CXXDefaultConstructor: 6470 S.DefineImplicitDefaultConstructor(DefaultLoc, 6471 cast<CXXConstructorDecl>(FD)); 6472 break; 6473 case Sema::CXXCopyConstructor: 6474 S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD)); 6475 break; 6476 case Sema::CXXCopyAssignment: 6477 S.DefineImplicitCopyAssignment(DefaultLoc, cast<CXXMethodDecl>(FD)); 6478 break; 6479 case Sema::CXXDestructor: 6480 S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(FD)); 6481 break; 6482 case Sema::CXXMoveConstructor: 6483 S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(FD)); 6484 break; 6485 case Sema::CXXMoveAssignment: 6486 S.DefineImplicitMoveAssignment(DefaultLoc, cast<CXXMethodDecl>(FD)); 6487 break; 6488 case Sema::CXXInvalid: 6489 llvm_unreachable("Invalid special member.")__builtin_unreachable(); 6490 } 6491} 6492 6493/// Determine whether a type is permitted to be passed or returned in 6494/// registers, per C++ [class.temporary]p3. 6495static bool canPassInRegisters(Sema &S, CXXRecordDecl *D, 6496 TargetInfo::CallingConvKind CCK) { 6497 if (D->isDependentType() || D->isInvalidDecl()) 6498 return false; 6499 6500 // Clang <= 4 used the pre-C++11 rule, which ignores move operations. 6501 // The PS4 platform ABI follows the behavior of Clang 3.2. 6502 if (CCK == TargetInfo::CCK_ClangABI4OrPS4) 6503 return !D->hasNonTrivialDestructorForCall() && 6504 !D->hasNonTrivialCopyConstructorForCall(); 6505 6506 if (CCK == TargetInfo::CCK_MicrosoftWin64) { 6507 bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false; 6508 bool DtorIsTrivialForCall = false; 6509 6510 // If a class has at least one non-deleted, trivial copy constructor, it 6511 // is passed according to the C ABI. Otherwise, it is passed indirectly. 6512 // 6513 // Note: This permits classes with non-trivial copy or move ctors to be 6514 // passed in registers, so long as they *also* have a trivial copy ctor, 6515 // which is non-conforming. 6516 if (D->needsImplicitCopyConstructor()) { 6517 if (!D->defaultedCopyConstructorIsDeleted()) { 6518 if (D->hasTrivialCopyConstructor()) 6519 CopyCtorIsTrivial = true; 6520 if (D->hasTrivialCopyConstructorForCall()) 6521 CopyCtorIsTrivialForCall = true; 6522 } 6523 } else { 6524 for (const CXXConstructorDecl *CD : D->ctors()) { 6525 if (CD->isCopyConstructor() && !CD->isDeleted()) { 6526 if (CD->isTrivial()) 6527 CopyCtorIsTrivial = true; 6528 if (CD->isTrivialForCall()) 6529 CopyCtorIsTrivialForCall = true; 6530 } 6531 } 6532 } 6533 6534 if (D->needsImplicitDestructor()) { 6535 if (!D->defaultedDestructorIsDeleted() && 6536 D->hasTrivialDestructorForCall()) 6537 DtorIsTrivialForCall = true; 6538 } else if (const auto *DD = D->getDestructor()) { 6539 if (!DD->isDeleted() && DD->isTrivialForCall()) 6540 DtorIsTrivialForCall = true; 6541 } 6542 6543 // If the copy ctor and dtor are both trivial-for-calls, pass direct. 6544 if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall) 6545 return true; 6546 6547 // If a class has a destructor, we'd really like to pass it indirectly 6548 // because it allows us to elide copies. Unfortunately, MSVC makes that 6549 // impossible for small types, which it will pass in a single register or 6550 // stack slot. Most objects with dtors are large-ish, so handle that early. 6551 // We can't call out all large objects as being indirect because there are 6552 // multiple x64 calling conventions and the C++ ABI code shouldn't dictate 6553 // how we pass large POD types. 6554 6555 // Note: This permits small classes with nontrivial destructors to be 6556 // passed in registers, which is non-conforming. 6557 bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64(); 6558 uint64_t TypeSize = isAArch64 ? 128 : 64; 6559 6560 if (CopyCtorIsTrivial && 6561 S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize) 6562 return true; 6563 return false; 6564 } 6565 6566 // Per C++ [class.temporary]p3, the relevant condition is: 6567 // each copy constructor, move constructor, and destructor of X is 6568 // either trivial or deleted, and X has at least one non-deleted copy 6569 // or move constructor 6570 bool HasNonDeletedCopyOrMove = false; 6571 6572 if (D->needsImplicitCopyConstructor() && 6573 !D->defaultedCopyConstructorIsDeleted()) { 6574 if (!D->hasTrivialCopyConstructorForCall()) 6575 return false; 6576 HasNonDeletedCopyOrMove = true; 6577 } 6578 6579 if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() && 6580 !D->defaultedMoveConstructorIsDeleted()) { 6581 if (!D->hasTrivialMoveConstructorForCall()) 6582 return false; 6583 HasNonDeletedCopyOrMove = true; 6584 } 6585 6586 if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() && 6587 !D->hasTrivialDestructorForCall()) 6588 return false; 6589 6590 for (const CXXMethodDecl *MD : D->methods()) { 6591 if (MD->isDeleted()) 6592 continue; 6593 6594 auto *CD = dyn_cast<CXXConstructorDecl>(MD); 6595 if (CD && CD->isCopyOrMoveConstructor()) 6596 HasNonDeletedCopyOrMove = true; 6597 else if (!isa<CXXDestructorDecl>(MD)) 6598 continue; 6599 6600 if (!MD->isTrivialForCall()) 6601 return false; 6602 } 6603 6604 return HasNonDeletedCopyOrMove; 6605} 6606 6607/// Report an error regarding overriding, along with any relevant 6608/// overridden methods. 6609/// 6610/// \param DiagID the primary error to report. 6611/// \param MD the overriding method. 6612static bool 6613ReportOverrides(Sema &S, unsigned DiagID, const CXXMethodDecl *MD, 6614 llvm::function_ref<bool(const CXXMethodDecl *)> Report) { 6615 bool IssuedDiagnostic = false; 6616 for (const CXXMethodDecl *O : MD->overridden_methods()) { 6617 if (Report(O)) { 6618 if (!IssuedDiagnostic) { 6619 S.Diag(MD->getLocation(), DiagID) << MD->getDeclName(); 6620 IssuedDiagnostic = true; 6621 } 6622 S.Diag(O->getLocation(), diag::note_overridden_virtual_function); 6623 } 6624 } 6625 return IssuedDiagnostic; 6626} 6627 6628/// Perform semantic checks on a class definition that has been 6629/// completing, introducing implicitly-declared members, checking for 6630/// abstract types, etc. 6631/// 6632/// \param S The scope in which the class was parsed. Null if we didn't just 6633/// parse a class definition. 6634/// \param Record The completed class. 6635void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) { 6636 if (!Record) 6637 return; 6638 6639 if (Record->isAbstract() && !Record->isInvalidDecl()) { 6640 AbstractUsageInfo Info(*this, Record); 6641 CheckAbstractClassUsage(Info, Record); 6642 } 6643 6644 // If this is not an aggregate type and has no user-declared constructor, 6645 // complain about any non-static data members of reference or const scalar 6646 // type, since they will never get initializers. 6647 if (!Record->isInvalidDecl() && !Record->isDependentType() && 6648 !Record->isAggregate() && !Record->hasUserDeclaredConstructor() && 6649 !Record->isLambda()) { 6650 bool Complained = false; 6651 for (const auto *F : Record->fields()) { 6652 if (F->hasInClassInitializer() || F->isUnnamedBitfield()) 6653 continue; 6654 6655 if (F->getType()->isReferenceType() || 6656 (F->getType().isConstQualified() && F->getType()->isScalarType())) { 6657 if (!Complained) { 6658 Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst) 6659 << Record->getTagKind() << Record; 6660 Complained = true; 6661 } 6662 6663 Diag(F->getLocation(), diag::note_refconst_member_not_initialized) 6664 << F->getType()->isReferenceType() 6665 << F->getDeclName(); 6666 } 6667 } 6668 } 6669 6670 if (Record->getIdentifier()) { 6671 // C++ [class.mem]p13: 6672 // If T is the name of a class, then each of the following shall have a 6673 // name different from T: 6674 // - every member of every anonymous union that is a member of class T. 6675 // 6676 // C++ [class.mem]p14: 6677 // In addition, if class T has a user-declared constructor (12.1), every 6678 // non-static data member of class T shall have a name different from T. 6679 DeclContext::lookup_result R = Record->lookup(Record->getDeclName()); 6680 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; 6681 ++I) { 6682 NamedDecl *D = (*I)->getUnderlyingDecl(); 6683 if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) && 6684 Record->hasUserDeclaredConstructor()) || 6685 isa<IndirectFieldDecl>(D)) { 6686 Diag((*I)->getLocation(), diag::err_member_name_of_class) 6687 << D->getDeclName(); 6688 break; 6689 } 6690 } 6691 } 6692 6693 // Warn if the class has virtual methods but non-virtual public destructor. 6694 if (Record->isPolymorphic() && !Record->isDependentType()) { 6695 CXXDestructorDecl *dtor = Record->getDestructor(); 6696 if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) && 6697 !Record->hasAttr<FinalAttr>()) 6698 Diag(dtor ? dtor->getLocation() : Record->getLocation(), 6699 diag::warn_non_virtual_dtor) << Context.getRecordType(Record); 6700 } 6701 6702 if (Record->isAbstract()) { 6703 if (FinalAttr *FA = Record->getAttr<FinalAttr>()) { 6704 Diag(Record->getLocation(), diag::warn_abstract_final_class) 6705 << FA->isSpelledAsSealed(); 6706 DiagnoseAbstractType(Record); 6707 } 6708 } 6709 6710 // Warn if the class has a final destructor but is not itself marked final. 6711 if (!Record->hasAttr<FinalAttr>()) { 6712 if (const CXXDestructorDecl *dtor = Record->getDestructor()) { 6713 if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) { 6714 Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class) 6715 << FA->isSpelledAsSealed() 6716 << FixItHint::CreateInsertion( 6717 getLocForEndOfToken(Record->getLocation()), 6718 (FA->isSpelledAsSealed() ? " sealed" : " final")); 6719 Diag(Record->getLocation(), 6720 diag::note_final_dtor_non_final_class_silence) 6721 << Context.getRecordType(Record) << FA->isSpelledAsSealed(); 6722 } 6723 } 6724 } 6725 6726 // See if trivial_abi has to be dropped. 6727 if (Record->hasAttr<TrivialABIAttr>()) 6728 checkIllFormedTrivialABIStruct(*Record); 6729 6730 // Set HasTrivialSpecialMemberForCall if the record has attribute 6731 // "trivial_abi". 6732 bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>(); 6733 6734 if (HasTrivialABI) 6735 Record->setHasTrivialSpecialMemberForCall(); 6736 6737 // Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=). 6738 // We check these last because they can depend on the properties of the 6739 // primary comparison functions (==, <=>). 6740 llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons; 6741 6742 // Perform checks that can't be done until we know all the properties of a 6743 // member function (whether it's defaulted, deleted, virtual, overriding, 6744 // ...). 6745 auto CheckCompletedMemberFunction = [&](CXXMethodDecl *MD) { 6746 // A static function cannot override anything. 6747 if (MD->getStorageClass() == SC_Static) { 6748 if (ReportOverrides(*this, diag::err_static_overrides_virtual, MD, 6749 [](const CXXMethodDecl *) { return true; })) 6750 return; 6751 } 6752 6753 // A deleted function cannot override a non-deleted function and vice 6754 // versa. 6755 if (ReportOverrides(*this, 6756 MD->isDeleted() ? diag::err_deleted_override 6757 : diag::err_non_deleted_override, 6758 MD, [&](const CXXMethodDecl *V) { 6759 return MD->isDeleted() != V->isDeleted(); 6760 })) { 6761 if (MD->isDefaulted() && MD->isDeleted()) 6762 // Explain why this defaulted function was deleted. 6763 DiagnoseDeletedDefaultedFunction(MD); 6764 return; 6765 } 6766 6767 // A consteval function cannot override a non-consteval function and vice 6768 // versa. 6769 if (ReportOverrides(*this, 6770 MD->isConsteval() ? diag::err_consteval_override 6771 : diag::err_non_consteval_override, 6772 MD, [&](const CXXMethodDecl *V) { 6773 return MD->isConsteval() != V->isConsteval(); 6774 })) { 6775 if (MD->isDefaulted() && MD->isDeleted()) 6776 // Explain why this defaulted function was deleted. 6777 DiagnoseDeletedDefaultedFunction(MD); 6778 return; 6779 } 6780 }; 6781 6782 auto CheckForDefaultedFunction = [&](FunctionDecl *FD) -> bool { 6783 if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted()) 6784 return false; 6785 6786 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD); 6787 if (DFK.asComparison() == DefaultedComparisonKind::NotEqual || 6788 DFK.asComparison() == DefaultedComparisonKind::Relational) { 6789 DefaultedSecondaryComparisons.push_back(FD); 6790 return true; 6791 } 6792 6793 CheckExplicitlyDefaultedFunction(S, FD); 6794 return false; 6795 }; 6796 6797 auto CompleteMemberFunction = [&](CXXMethodDecl *M) { 6798 // Check whether the explicitly-defaulted members are valid. 6799 bool Incomplete = CheckForDefaultedFunction(M); 6800 6801 // Skip the rest of the checks for a member of a dependent class. 6802 if (Record->isDependentType()) 6803 return; 6804 6805 // For an explicitly defaulted or deleted special member, we defer 6806 // determining triviality until the class is complete. That time is now! 6807 CXXSpecialMember CSM = getSpecialMember(M); 6808 if (!M->isImplicit() && !M->isUserProvided()) { 6809 if (CSM != CXXInvalid) { 6810 M->setTrivial(SpecialMemberIsTrivial(M, CSM)); 6811 // Inform the class that we've finished declaring this member. 6812 Record->finishedDefaultedOrDeletedMember(M); 6813 M->setTrivialForCall( 6814 HasTrivialABI || 6815 SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI)); 6816 Record->setTrivialForCallFlags(M); 6817 } 6818 } 6819 6820 // Set triviality for the purpose of calls if this is a user-provided 6821 // copy/move constructor or destructor. 6822 if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor || 6823 CSM == CXXDestructor) && M->isUserProvided()) { 6824 M->setTrivialForCall(HasTrivialABI); 6825 Record->setTrivialForCallFlags(M); 6826 } 6827 6828 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() && 6829 M->hasAttr<DLLExportAttr>()) { 6830 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) && 6831 M->isTrivial() && 6832 (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor || 6833 CSM == CXXDestructor)) 6834 M->dropAttr<DLLExportAttr>(); 6835 6836 if (M->hasAttr<DLLExportAttr>()) { 6837 // Define after any fields with in-class initializers have been parsed. 6838 DelayedDllExportMemberFunctions.push_back(M); 6839 } 6840 } 6841 6842 // Define defaulted constexpr virtual functions that override a base class 6843 // function right away. 6844 // FIXME: We can defer doing this until the vtable is marked as used. 6845 if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods()) 6846 DefineDefaultedFunction(*this, M, M->getLocation()); 6847 6848 if (!Incomplete) 6849 CheckCompletedMemberFunction(M); 6850 }; 6851 6852 // Check the destructor before any other member function. We need to 6853 // determine whether it's trivial in order to determine whether the claas 6854 // type is a literal type, which is a prerequisite for determining whether 6855 // other special member functions are valid and whether they're implicitly 6856 // 'constexpr'. 6857 if (CXXDestructorDecl *Dtor = Record->getDestructor()) 6858 CompleteMemberFunction(Dtor); 6859 6860 bool HasMethodWithOverrideControl = false, 6861 HasOverridingMethodWithoutOverrideControl = false; 6862 for (auto *D : Record->decls()) { 6863 if (auto *M = dyn_cast<CXXMethodDecl>(D)) { 6864 // FIXME: We could do this check for dependent types with non-dependent 6865 // bases. 6866 if (!Record->isDependentType()) { 6867 // See if a method overloads virtual methods in a base 6868 // class without overriding any. 6869 if (!M->isStatic()) 6870 DiagnoseHiddenVirtualMethods(M); 6871 if (M->hasAttr<OverrideAttr>()) 6872 HasMethodWithOverrideControl = true; 6873 else if (M->size_overridden_methods() > 0) 6874 HasOverridingMethodWithoutOverrideControl = true; 6875 } 6876 6877 if (!isa<CXXDestructorDecl>(M)) 6878 CompleteMemberFunction(M); 6879 } else if (auto *F = dyn_cast<FriendDecl>(D)) { 6880 CheckForDefaultedFunction( 6881 dyn_cast_or_null<FunctionDecl>(F->getFriendDecl())); 6882 } 6883 } 6884 6885 if (HasOverridingMethodWithoutOverrideControl) { 6886 bool HasInconsistentOverrideControl = HasMethodWithOverrideControl; 6887 for (auto *M : Record->methods()) 6888 DiagnoseAbsenceOfOverrideControl(M, HasInconsistentOverrideControl); 6889 } 6890 6891 // Check the defaulted secondary comparisons after any other member functions. 6892 for (FunctionDecl *FD : DefaultedSecondaryComparisons) { 6893 CheckExplicitlyDefaultedFunction(S, FD); 6894 6895 // If this is a member function, we deferred checking it until now. 6896 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) 6897 CheckCompletedMemberFunction(MD); 6898 } 6899 6900 // ms_struct is a request to use the same ABI rules as MSVC. Check 6901 // whether this class uses any C++ features that are implemented 6902 // completely differently in MSVC, and if so, emit a diagnostic. 6903 // That diagnostic defaults to an error, but we allow projects to 6904 // map it down to a warning (or ignore it). It's a fairly common 6905 // practice among users of the ms_struct pragma to mass-annotate 6906 // headers, sweeping up a bunch of types that the project doesn't 6907 // really rely on MSVC-compatible layout for. We must therefore 6908 // support "ms_struct except for C++ stuff" as a secondary ABI. 6909 // Don't emit this diagnostic if the feature was enabled as a 6910 // language option (as opposed to via a pragma or attribute), as 6911 // the option -mms-bitfields otherwise essentially makes it impossible 6912 // to build C++ code, unless this diagnostic is turned off. 6913 if (Record->isMsStruct(Context) && !Context.getLangOpts().MSBitfields && 6914 (Record->isPolymorphic() || Record->getNumBases())) { 6915 Diag(Record->getLocation(), diag::warn_cxx_ms_struct); 6916 } 6917 6918 checkClassLevelDLLAttribute(Record); 6919 checkClassLevelCodeSegAttribute(Record); 6920 6921 bool ClangABICompat4 = 6922 Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4; 6923 TargetInfo::CallingConvKind CCK = 6924 Context.getTargetInfo().getCallingConvKind(ClangABICompat4); 6925 bool CanPass = canPassInRegisters(*this, Record, CCK); 6926 6927 // Do not change ArgPassingRestrictions if it has already been set to 6928 // APK_CanNeverPassInRegs. 6929 if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs) 6930 Record->setArgPassingRestrictions(CanPass 6931 ? RecordDecl::APK_CanPassInRegs 6932 : RecordDecl::APK_CannotPassInRegs); 6933 6934 // If canPassInRegisters returns true despite the record having a non-trivial 6935 // destructor, the record is destructed in the callee. This happens only when 6936 // the record or one of its subobjects has a field annotated with trivial_abi 6937 // or a field qualified with ObjC __strong/__weak. 6938 if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee()) 6939 Record->setParamDestroyedInCallee(true); 6940 else if (Record->hasNonTrivialDestructor()) 6941 Record->setParamDestroyedInCallee(CanPass); 6942 6943 if (getLangOpts().ForceEmitVTables) { 6944 // If we want to emit all the vtables, we need to mark it as used. This 6945 // is especially required for cases like vtable assumption loads. 6946 MarkVTableUsed(Record->getInnerLocStart(), Record); 6947 } 6948 6949 if (getLangOpts().CUDA) { 6950 if (Record->hasAttr<CUDADeviceBuiltinSurfaceTypeAttr>()) 6951 checkCUDADeviceBuiltinSurfaceClassTemplate(*this, Record); 6952 else if (Record->hasAttr<CUDADeviceBuiltinTextureTypeAttr>()) 6953 checkCUDADeviceBuiltinTextureClassTemplate(*this, Record); 6954 } 6955} 6956 6957/// Look up the special member function that would be called by a special 6958/// member function for a subobject of class type. 6959/// 6960/// \param Class The class type of the subobject. 6961/// \param CSM The kind of special member function. 6962/// \param FieldQuals If the subobject is a field, its cv-qualifiers. 6963/// \param ConstRHS True if this is a copy operation with a const object 6964/// on its RHS, that is, if the argument to the outer special member 6965/// function is 'const' and this is not a field marked 'mutable'. 6966static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember( 6967 Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM, 6968 unsigned FieldQuals, bool ConstRHS) { 6969 unsigned LHSQuals = 0; 6970 if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment) 6971 LHSQuals = FieldQuals; 6972 6973 unsigned RHSQuals = FieldQuals; 6974 if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor) 6975 RHSQuals = 0; 6976 else if (ConstRHS) 6977 RHSQuals |= Qualifiers::Const; 6978 6979 return S.LookupSpecialMember(Class, CSM, 6980 RHSQuals & Qualifiers::Const, 6981 RHSQuals & Qualifiers::Volatile, 6982 false, 6983 LHSQuals & Qualifiers::Const, 6984 LHSQuals & Qualifiers::Volatile); 6985} 6986 6987class Sema::InheritedConstructorInfo { 6988 Sema &S; 6989 SourceLocation UseLoc; 6990 6991 /// A mapping from the base classes through which the constructor was 6992 /// inherited to the using shadow declaration in that base class (or a null 6993 /// pointer if the constructor was declared in that base class). 6994 llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *> 6995 InheritedFromBases; 6996 6997public: 6998 InheritedConstructorInfo(Sema &S, SourceLocation UseLoc, 6999 ConstructorUsingShadowDecl *Shadow) 7000 : S(S), UseLoc(UseLoc) { 7001 bool DiagnosedMultipleConstructedBases = false; 7002 CXXRecordDecl *ConstructedBase = nullptr; 7003 BaseUsingDecl *ConstructedBaseIntroducer = nullptr; 7004 7005 // Find the set of such base class subobjects and check that there's a 7006 // unique constructed subobject. 7007 for (auto *D : Shadow->redecls()) { 7008 auto *DShadow = cast<ConstructorUsingShadowDecl>(D); 7009 auto *DNominatedBase = DShadow->getNominatedBaseClass(); 7010 auto *DConstructedBase = DShadow->getConstructedBaseClass(); 7011 7012 InheritedFromBases.insert( 7013 std::make_pair(DNominatedBase->getCanonicalDecl(), 7014 DShadow->getNominatedBaseClassShadowDecl())); 7015 if (DShadow->constructsVirtualBase()) 7016 InheritedFromBases.insert( 7017 std::make_pair(DConstructedBase->getCanonicalDecl(), 7018 DShadow->getConstructedBaseClassShadowDecl())); 7019 else 7020 assert(DNominatedBase == DConstructedBase)((void)0); 7021 7022 // [class.inhctor.init]p2: 7023 // If the constructor was inherited from multiple base class subobjects 7024 // of type B, the program is ill-formed. 7025 if (!ConstructedBase) { 7026 ConstructedBase = DConstructedBase; 7027 ConstructedBaseIntroducer = D->getIntroducer(); 7028 } else if (ConstructedBase != DConstructedBase && 7029 !Shadow->isInvalidDecl()) { 7030 if (!DiagnosedMultipleConstructedBases) { 7031 S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor) 7032 << Shadow->getTargetDecl(); 7033 S.Diag(ConstructedBaseIntroducer->getLocation(), 7034 diag::note_ambiguous_inherited_constructor_using) 7035 << ConstructedBase; 7036 DiagnosedMultipleConstructedBases = true; 7037 } 7038 S.Diag(D->getIntroducer()->getLocation(), 7039 diag::note_ambiguous_inherited_constructor_using) 7040 << DConstructedBase; 7041 } 7042 } 7043 7044 if (DiagnosedMultipleConstructedBases) 7045 Shadow->setInvalidDecl(); 7046 } 7047 7048 /// Find the constructor to use for inherited construction of a base class, 7049 /// and whether that base class constructor inherits the constructor from a 7050 /// virtual base class (in which case it won't actually invoke it). 7051 std::pair<CXXConstructorDecl *, bool> 7052 findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const { 7053 auto It = InheritedFromBases.find(Base->getCanonicalDecl()); 7054 if (It == InheritedFromBases.end()) 7055 return std::make_pair(nullptr, false); 7056 7057 // This is an intermediary class. 7058 if (It->second) 7059 return std::make_pair( 7060 S.findInheritingConstructor(UseLoc, Ctor, It->second), 7061 It->second->constructsVirtualBase()); 7062 7063 // This is the base class from which the constructor was inherited. 7064 return std::make_pair(Ctor, false); 7065 } 7066}; 7067 7068/// Is the special member function which would be selected to perform the 7069/// specified operation on the specified class type a constexpr constructor? 7070static bool 7071specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl, 7072 Sema::CXXSpecialMember CSM, unsigned Quals, 7073 bool ConstRHS, 7074 CXXConstructorDecl *InheritedCtor = nullptr, 7075 Sema::InheritedConstructorInfo *Inherited = nullptr) { 7076 // If we're inheriting a constructor, see if we need to call it for this base 7077 // class. 7078 if (InheritedCtor) { 7079 assert(CSM == Sema::CXXDefaultConstructor)((void)0); 7080 auto BaseCtor = 7081 Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first; 7082 if (BaseCtor) 7083 return BaseCtor->isConstexpr(); 7084 } 7085 7086 if (CSM == Sema::CXXDefaultConstructor) 7087 return ClassDecl->hasConstexprDefaultConstructor(); 7088 if (CSM == Sema::CXXDestructor) 7089 return ClassDecl->hasConstexprDestructor(); 7090 7091 Sema::SpecialMemberOverloadResult SMOR = 7092 lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS); 7093 if (!SMOR.getMethod()) 7094 // A constructor we wouldn't select can't be "involved in initializing" 7095 // anything. 7096 return true; 7097 return SMOR.getMethod()->isConstexpr(); 7098} 7099 7100/// Determine whether the specified special member function would be constexpr 7101/// if it were implicitly defined. 7102static bool defaultedSpecialMemberIsConstexpr( 7103 Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM, 7104 bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr, 7105 Sema::InheritedConstructorInfo *Inherited = nullptr) { 7106 if (!S.getLangOpts().CPlusPlus11) 7107 return false; 7108 7109 // C++11 [dcl.constexpr]p4: 7110 // In the definition of a constexpr constructor [...] 7111 bool Ctor = true; 7112 switch (CSM) { 7113 case Sema::CXXDefaultConstructor: 7114 if (Inherited) 7115 break; 7116 // Since default constructor lookup is essentially trivial (and cannot 7117 // involve, for instance, template instantiation), we compute whether a 7118 // defaulted default constructor is constexpr directly within CXXRecordDecl. 7119 // 7120 // This is important for performance; we need to know whether the default 7121 // constructor is constexpr to determine whether the type is a literal type. 7122 return ClassDecl->defaultedDefaultConstructorIsConstexpr(); 7123 7124 case Sema::CXXCopyConstructor: 7125 case Sema::CXXMoveConstructor: 7126 // For copy or move constructors, we need to perform overload resolution. 7127 break; 7128 7129 case Sema::CXXCopyAssignment: 7130 case Sema::CXXMoveAssignment: 7131 if (!S.getLangOpts().CPlusPlus14) 7132 return false; 7133 // In C++1y, we need to perform overload resolution. 7134 Ctor = false; 7135 break; 7136 7137 case Sema::CXXDestructor: 7138 return ClassDecl->defaultedDestructorIsConstexpr(); 7139 7140 case Sema::CXXInvalid: 7141 return false; 7142 } 7143 7144 // -- if the class is a non-empty union, or for each non-empty anonymous 7145 // union member of a non-union class, exactly one non-static data member 7146 // shall be initialized; [DR1359] 7147 // 7148 // If we squint, this is guaranteed, since exactly one non-static data member 7149 // will be initialized (if the constructor isn't deleted), we just don't know 7150 // which one. 7151 if (Ctor && ClassDecl->isUnion()) 7152 return CSM == Sema::CXXDefaultConstructor 7153 ? ClassDecl->hasInClassInitializer() || 7154 !ClassDecl->hasVariantMembers() 7155 : true; 7156 7157 // -- the class shall not have any virtual base classes; 7158 if (Ctor && ClassDecl->getNumVBases()) 7159 return false; 7160 7161 // C++1y [class.copy]p26: 7162 // -- [the class] is a literal type, and 7163 if (!Ctor && !ClassDecl->isLiteral()) 7164 return false; 7165 7166 // -- every constructor involved in initializing [...] base class 7167 // sub-objects shall be a constexpr constructor; 7168 // -- the assignment operator selected to copy/move each direct base 7169 // class is a constexpr function, and 7170 for (const auto &B : ClassDecl->bases()) { 7171 const RecordType *BaseType = B.getType()->getAs<RecordType>(); 7172 if (!BaseType) continue; 7173 7174 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl()); 7175 if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg, 7176 InheritedCtor, Inherited)) 7177 return false; 7178 } 7179 7180 // -- every constructor involved in initializing non-static data members 7181 // [...] shall be a constexpr constructor; 7182 // -- every non-static data member and base class sub-object shall be 7183 // initialized 7184 // -- for each non-static data member of X that is of class type (or array 7185 // thereof), the assignment operator selected to copy/move that member is 7186 // a constexpr function 7187 for (const auto *F : ClassDecl->fields()) { 7188 if (F->isInvalidDecl()) 7189 continue; 7190 if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer()) 7191 continue; 7192 QualType BaseType = S.Context.getBaseElementType(F->getType()); 7193 if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) { 7194 CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); 7195 if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM, 7196 BaseType.getCVRQualifiers(), 7197 ConstArg && !F->isMutable())) 7198 return false; 7199 } else if (CSM == Sema::CXXDefaultConstructor) { 7200 return false; 7201 } 7202 } 7203 7204 // All OK, it's constexpr! 7205 return true; 7206} 7207 7208namespace { 7209/// RAII object to register a defaulted function as having its exception 7210/// specification computed. 7211struct ComputingExceptionSpec { 7212 Sema &S; 7213 7214 ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc) 7215 : S(S) { 7216 Sema::CodeSynthesisContext Ctx; 7217 Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation; 7218 Ctx.PointOfInstantiation = Loc; 7219 Ctx.Entity = FD; 7220 S.pushCodeSynthesisContext(Ctx); 7221 } 7222 ~ComputingExceptionSpec() { 7223 S.popCodeSynthesisContext(); 7224 } 7225}; 7226} 7227 7228static Sema::ImplicitExceptionSpecification 7229ComputeDefaultedSpecialMemberExceptionSpec( 7230 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, 7231 Sema::InheritedConstructorInfo *ICI); 7232 7233static Sema::ImplicitExceptionSpecification 7234ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc, 7235 FunctionDecl *FD, 7236 Sema::DefaultedComparisonKind DCK); 7237 7238static Sema::ImplicitExceptionSpecification 7239computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) { 7240 auto DFK = S.getDefaultedFunctionKind(FD); 7241 if (DFK.isSpecialMember()) 7242 return ComputeDefaultedSpecialMemberExceptionSpec( 7243 S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr); 7244 if (DFK.isComparison()) 7245 return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD, 7246 DFK.asComparison()); 7247 7248 auto *CD = cast<CXXConstructorDecl>(FD); 7249 assert(CD->getInheritedConstructor() &&((void)0) 7250 "only defaulted functions and inherited constructors have implicit "((void)0) 7251 "exception specs")((void)0); 7252 Sema::InheritedConstructorInfo ICI( 7253 S, Loc, CD->getInheritedConstructor().getShadowDecl()); 7254 return ComputeDefaultedSpecialMemberExceptionSpec( 7255 S, Loc, CD, Sema::CXXDefaultConstructor, &ICI); 7256} 7257 7258static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S, 7259 CXXMethodDecl *MD) { 7260 FunctionProtoType::ExtProtoInfo EPI; 7261 7262 // Build an exception specification pointing back at this member. 7263 EPI.ExceptionSpec.Type = EST_Unevaluated; 7264 EPI.ExceptionSpec.SourceDecl = MD; 7265 7266 // Set the calling convention to the default for C++ instance methods. 7267 EPI.ExtInfo = EPI.ExtInfo.withCallingConv( 7268 S.Context.getDefaultCallingConvention(/*IsVariadic=*/false, 7269 /*IsCXXMethod=*/true)); 7270 return EPI; 7271} 7272 7273void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) { 7274 const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>(); 7275 if (FPT->getExceptionSpecType() != EST_Unevaluated) 7276 return; 7277 7278 // Evaluate the exception specification. 7279 auto IES = computeImplicitExceptionSpec(*this, Loc, FD); 7280 auto ESI = IES.getExceptionSpec(); 7281 7282 // Update the type of the special member to use it. 7283 UpdateExceptionSpec(FD, ESI); 7284} 7285 7286void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) { 7287 assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted")((void)0); 7288 7289 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD); 7290 if (!DefKind) { 7291 assert(FD->getDeclContext()->isDependentContext())((void)0); 7292 return; 7293 } 7294 7295 if (DefKind.isComparison()) 7296 UnusedPrivateFields.clear(); 7297 7298 if (DefKind.isSpecialMember() 7299 ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD), 7300 DefKind.asSpecialMember()) 7301 : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison())) 7302 FD->setInvalidDecl(); 7303} 7304 7305bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD, 7306 CXXSpecialMember CSM) { 7307 CXXRecordDecl *RD = MD->getParent(); 7308 7309 assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&((void)0) 7310 "not an explicitly-defaulted special member")((void)0); 7311 7312 // Defer all checking for special members of a dependent type. 7313 if (RD->isDependentType()) 7314 return false; 7315 7316 // Whether this was the first-declared instance of the constructor. 7317 // This affects whether we implicitly add an exception spec and constexpr. 7318 bool First = MD == MD->getCanonicalDecl(); 7319 7320 bool HadError = false; 7321 7322 // C++11 [dcl.fct.def.default]p1: 7323 // A function that is explicitly defaulted shall 7324 // -- be a special member function [...] (checked elsewhere), 7325 // -- have the same type (except for ref-qualifiers, and except that a 7326 // copy operation can take a non-const reference) as an implicit 7327 // declaration, and 7328 // -- not have default arguments. 7329 // C++2a changes the second bullet to instead delete the function if it's 7330 // defaulted on its first declaration, unless it's "an assignment operator, 7331 // and its return type differs or its parameter type is not a reference". 7332 bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus20 && First; 7333 bool ShouldDeleteForTypeMismatch = false; 7334 unsigned ExpectedParams = 1; 7335 if (CSM == CXXDefaultConstructor || CSM == CXXDestructor) 7336 ExpectedParams = 0; 7337 if (MD->getNumParams() != ExpectedParams) { 7338 // This checks for default arguments: a copy or move constructor with a 7339 // default argument is classified as a default constructor, and assignment 7340 // operations and destructors can't have default arguments. 7341 Diag(MD->getLocation(), diag::err_defaulted_special_member_params) 7342 << CSM << MD->getSourceRange(); 7343 HadError = true; 7344 } else if (MD->isVariadic()) { 7345 if (DeleteOnTypeMismatch) 7346 ShouldDeleteForTypeMismatch = true; 7347 else { 7348 Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic) 7349 << CSM << MD->getSourceRange(); 7350 HadError = true; 7351 } 7352 } 7353 7354 const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>(); 7355 7356 bool CanHaveConstParam = false; 7357 if (CSM == CXXCopyConstructor) 7358 CanHaveConstParam = RD->implicitCopyConstructorHasConstParam(); 7359 else if (CSM == CXXCopyAssignment) 7360 CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam(); 7361 7362 QualType ReturnType = Context.VoidTy; 7363 if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) { 7364 // Check for return type matching. 7365 ReturnType = Type->getReturnType(); 7366 7367 QualType DeclType = Context.getTypeDeclType(RD); 7368 DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace()); 7369 QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType); 7370 7371 if (!Context.hasSameType(ReturnType, ExpectedReturnType)) { 7372 Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type) 7373 << (CSM == CXXMoveAssignment) << ExpectedReturnType; 7374 HadError = true; 7375 } 7376 7377 // A defaulted special member cannot have cv-qualifiers. 7378 if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) { 7379 if (DeleteOnTypeMismatch) 7380 ShouldDeleteForTypeMismatch = true; 7381 else { 7382 Diag(MD->getLocation(), diag::err_defaulted_special_member_quals) 7383 << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14; 7384 HadError = true; 7385 } 7386 } 7387 } 7388 7389 // Check for parameter type matching. 7390 QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType(); 7391 bool HasConstParam = false; 7392 if (ExpectedParams && ArgType->isReferenceType()) { 7393 // Argument must be reference to possibly-const T. 7394 QualType ReferentType = ArgType->getPointeeType(); 7395 HasConstParam = ReferentType.isConstQualified(); 7396 7397 if (ReferentType.isVolatileQualified()) { 7398 if (DeleteOnTypeMismatch) 7399 ShouldDeleteForTypeMismatch = true; 7400 else { 7401 Diag(MD->getLocation(), 7402 diag::err_defaulted_special_member_volatile_param) << CSM; 7403 HadError = true; 7404 } 7405 } 7406 7407 if (HasConstParam && !CanHaveConstParam) { 7408 if (DeleteOnTypeMismatch) 7409 ShouldDeleteForTypeMismatch = true; 7410 else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) { 7411 Diag(MD->getLocation(), 7412 diag::err_defaulted_special_member_copy_const_param) 7413 << (CSM == CXXCopyAssignment); 7414 // FIXME: Explain why this special member can't be const. 7415 HadError = true; 7416 } else { 7417 Diag(MD->getLocation(), 7418 diag::err_defaulted_special_member_move_const_param) 7419 << (CSM == CXXMoveAssignment); 7420 HadError = true; 7421 } 7422 } 7423 } else if (ExpectedParams) { 7424 // A copy assignment operator can take its argument by value, but a 7425 // defaulted one cannot. 7426 assert(CSM == CXXCopyAssignment && "unexpected non-ref argument")((void)0); 7427 Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref); 7428 HadError = true; 7429 } 7430 7431 // C++11 [dcl.fct.def.default]p2: 7432 // An explicitly-defaulted function may be declared constexpr only if it 7433 // would have been implicitly declared as constexpr, 7434 // Do not apply this rule to members of class templates, since core issue 1358 7435 // makes such functions always instantiate to constexpr functions. For 7436 // functions which cannot be constexpr (for non-constructors in C++11 and for 7437 // destructors in C++14 and C++17), this is checked elsewhere. 7438 // 7439 // FIXME: This should not apply if the member is deleted. 7440 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM, 7441 HasConstParam); 7442 if ((getLangOpts().CPlusPlus20 || 7443 (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD) 7444 : isa<CXXConstructorDecl>(MD))) && 7445 MD->isConstexpr() && !Constexpr && 7446 MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) { 7447 Diag(MD->getBeginLoc(), MD->isConsteval() 7448 ? diag::err_incorrect_defaulted_consteval 7449 : diag::err_incorrect_defaulted_constexpr) 7450 << CSM; 7451 // FIXME: Explain why the special member can't be constexpr. 7452 HadError = true; 7453 } 7454 7455 if (First) { 7456 // C++2a [dcl.fct.def.default]p3: 7457 // If a function is explicitly defaulted on its first declaration, it is 7458 // implicitly considered to be constexpr if the implicit declaration 7459 // would be. 7460 MD->setConstexprKind(Constexpr ? (MD->isConsteval() 7461 ? ConstexprSpecKind::Consteval 7462 : ConstexprSpecKind::Constexpr) 7463 : ConstexprSpecKind::Unspecified); 7464 7465 if (!Type->hasExceptionSpec()) { 7466 // C++2a [except.spec]p3: 7467 // If a declaration of a function does not have a noexcept-specifier 7468 // [and] is defaulted on its first declaration, [...] the exception 7469 // specification is as specified below 7470 FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo(); 7471 EPI.ExceptionSpec.Type = EST_Unevaluated; 7472 EPI.ExceptionSpec.SourceDecl = MD; 7473 MD->setType(Context.getFunctionType(ReturnType, 7474 llvm::makeArrayRef(&ArgType, 7475 ExpectedParams), 7476 EPI)); 7477 } 7478 } 7479 7480 if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) { 7481 if (First) { 7482 SetDeclDeleted(MD, MD->getLocation()); 7483 if (!inTemplateInstantiation() && !HadError) { 7484 Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM; 7485 if (ShouldDeleteForTypeMismatch) { 7486 Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM; 7487 } else { 7488 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true); 7489 } 7490 } 7491 if (ShouldDeleteForTypeMismatch && !HadError) { 7492 Diag(MD->getLocation(), 7493 diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM; 7494 } 7495 } else { 7496 // C++11 [dcl.fct.def.default]p4: 7497 // [For a] user-provided explicitly-defaulted function [...] if such a 7498 // function is implicitly defined as deleted, the program is ill-formed. 7499 Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM; 7500 assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl")((void)0); 7501 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true); 7502 HadError = true; 7503 } 7504 } 7505 7506 return HadError; 7507} 7508 7509namespace { 7510/// Helper class for building and checking a defaulted comparison. 7511/// 7512/// Defaulted functions are built in two phases: 7513/// 7514/// * First, the set of operations that the function will perform are 7515/// identified, and some of them are checked. If any of the checked 7516/// operations is invalid in certain ways, the comparison function is 7517/// defined as deleted and no body is built. 7518/// * Then, if the function is not defined as deleted, the body is built. 7519/// 7520/// This is accomplished by performing two visitation steps over the eventual 7521/// body of the function. 7522template<typename Derived, typename ResultList, typename Result, 7523 typename Subobject> 7524class DefaultedComparisonVisitor { 7525public: 7526 using DefaultedComparisonKind = Sema::DefaultedComparisonKind; 7527 7528 DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, 7529 DefaultedComparisonKind DCK) 7530 : S(S), RD(RD), FD(FD), DCK(DCK) { 7531 if (auto *Info = FD->getDefaultedFunctionInfo()) { 7532 // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an 7533 // UnresolvedSet to avoid this copy. 7534 Fns.assign(Info->getUnqualifiedLookups().begin(), 7535 Info->getUnqualifiedLookups().end()); 7536 } 7537 } 7538 7539 ResultList visit() { 7540 // The type of an lvalue naming a parameter of this function. 7541 QualType ParamLvalType = 7542 FD->getParamDecl(0)->getType().getNonReferenceType(); 7543 7544 ResultList Results; 7545 7546 switch (DCK) { 7547 case DefaultedComparisonKind::None: 7548 llvm_unreachable("not a defaulted comparison")__builtin_unreachable(); 7549 7550 case DefaultedComparisonKind::Equal: 7551 case DefaultedComparisonKind::ThreeWay: 7552 getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers()); 7553 return Results; 7554 7555 case DefaultedComparisonKind::NotEqual: 7556 case DefaultedComparisonKind::Relational: 7557 Results.add(getDerived().visitExpandedSubobject( 7558 ParamLvalType, getDerived().getCompleteObject())); 7559 return Results; 7560 } 7561 llvm_unreachable("")__builtin_unreachable(); 7562 } 7563 7564protected: 7565 Derived &getDerived() { return static_cast<Derived&>(*this); } 7566 7567 /// Visit the expanded list of subobjects of the given type, as specified in 7568 /// C++2a [class.compare.default]. 7569 /// 7570 /// \return \c true if the ResultList object said we're done, \c false if not. 7571 bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record, 7572 Qualifiers Quals) { 7573 // C++2a [class.compare.default]p4: 7574 // The direct base class subobjects of C 7575 for (CXXBaseSpecifier &Base : Record->bases()) 7576 if (Results.add(getDerived().visitSubobject( 7577 S.Context.getQualifiedType(Base.getType(), Quals), 7578 getDerived().getBase(&Base)))) 7579 return true; 7580 7581 // followed by the non-static data members of C 7582 for (FieldDecl *Field : Record->fields()) { 7583 // Recursively expand anonymous structs. 7584 if (Field->isAnonymousStructOrUnion()) { 7585 if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(), 7586 Quals)) 7587 return true; 7588 continue; 7589 } 7590 7591 // Figure out the type of an lvalue denoting this field. 7592 Qualifiers FieldQuals = Quals; 7593 if (Field->isMutable()) 7594 FieldQuals.removeConst(); 7595 QualType FieldType = 7596 S.Context.getQualifiedType(Field->getType(), FieldQuals); 7597 7598 if (Results.add(getDerived().visitSubobject( 7599 FieldType, getDerived().getField(Field)))) 7600 return true; 7601 } 7602 7603 // form a list of subobjects. 7604 return false; 7605 } 7606 7607 Result visitSubobject(QualType Type, Subobject Subobj) { 7608 // In that list, any subobject of array type is recursively expanded 7609 const ArrayType *AT = S.Context.getAsArrayType(Type); 7610 if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT)) 7611 return getDerived().visitSubobjectArray(CAT->getElementType(), 7612 CAT->getSize(), Subobj); 7613 return getDerived().visitExpandedSubobject(Type, Subobj); 7614 } 7615 7616 Result visitSubobjectArray(QualType Type, const llvm::APInt &Size, 7617 Subobject Subobj) { 7618 return getDerived().visitSubobject(Type, Subobj); 7619 } 7620 7621protected: 7622 Sema &S; 7623 CXXRecordDecl *RD; 7624 FunctionDecl *FD; 7625 DefaultedComparisonKind DCK; 7626 UnresolvedSet<16> Fns; 7627}; 7628 7629/// Information about a defaulted comparison, as determined by 7630/// DefaultedComparisonAnalyzer. 7631struct DefaultedComparisonInfo { 7632 bool Deleted = false; 7633 bool Constexpr = true; 7634 ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering; 7635 7636 static DefaultedComparisonInfo deleted() { 7637 DefaultedComparisonInfo Deleted; 7638 Deleted.Deleted = true; 7639 return Deleted; 7640 } 7641 7642 bool add(const DefaultedComparisonInfo &R) { 7643 Deleted |= R.Deleted; 7644 Constexpr &= R.Constexpr; 7645 Category = commonComparisonType(Category, R.Category); 7646 return Deleted; 7647 } 7648}; 7649 7650/// An element in the expanded list of subobjects of a defaulted comparison, as 7651/// specified in C++2a [class.compare.default]p4. 7652struct DefaultedComparisonSubobject { 7653 enum { CompleteObject, Member, Base } Kind; 7654 NamedDecl *Decl; 7655 SourceLocation Loc; 7656}; 7657 7658/// A visitor over the notional body of a defaulted comparison that determines 7659/// whether that body would be deleted or constexpr. 7660class DefaultedComparisonAnalyzer 7661 : public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer, 7662 DefaultedComparisonInfo, 7663 DefaultedComparisonInfo, 7664 DefaultedComparisonSubobject> { 7665public: 7666 enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr }; 7667 7668private: 7669 DiagnosticKind Diagnose; 7670 7671public: 7672 using Base = DefaultedComparisonVisitor; 7673 using Result = DefaultedComparisonInfo; 7674 using Subobject = DefaultedComparisonSubobject; 7675 7676 friend Base; 7677 7678 DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, 7679 DefaultedComparisonKind DCK, 7680 DiagnosticKind Diagnose = NoDiagnostics) 7681 : Base(S, RD, FD, DCK), Diagnose(Diagnose) {} 7682 7683 Result visit() { 7684 if ((DCK == DefaultedComparisonKind::Equal || 7685 DCK == DefaultedComparisonKind::ThreeWay) && 7686 RD->hasVariantMembers()) { 7687 // C++2a [class.compare.default]p2 [P2002R0]: 7688 // A defaulted comparison operator function for class C is defined as 7689 // deleted if [...] C has variant members. 7690 if (Diagnose == ExplainDeleted) { 7691 S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union) 7692 << FD << RD->isUnion() << RD; 7693 } 7694 return Result::deleted(); 7695 } 7696 7697 return Base::visit(); 7698 } 7699 7700private: 7701 Subobject getCompleteObject() { 7702 return Subobject{Subobject::CompleteObject, RD, FD->getLocation()}; 7703 } 7704 7705 Subobject getBase(CXXBaseSpecifier *Base) { 7706 return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(), 7707 Base->getBaseTypeLoc()}; 7708 } 7709 7710 Subobject getField(FieldDecl *Field) { 7711 return Subobject{Subobject::Member, Field, Field->getLocation()}; 7712 } 7713 7714 Result visitExpandedSubobject(QualType Type, Subobject Subobj) { 7715 // C++2a [class.compare.default]p2 [P2002R0]: 7716 // A defaulted <=> or == operator function for class C is defined as 7717 // deleted if any non-static data member of C is of reference type 7718 if (Type->isReferenceType()) { 7719 if (Diagnose == ExplainDeleted) { 7720 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member) 7721 << FD << RD; 7722 } 7723 return Result::deleted(); 7724 } 7725 7726 // [...] Let xi be an lvalue denoting the ith element [...] 7727 OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue); 7728 Expr *Args[] = {&Xi, &Xi}; 7729 7730 // All operators start by trying to apply that same operator recursively. 7731 OverloadedOperatorKind OO = FD->getOverloadedOperator(); 7732 assert(OO != OO_None && "not an overloaded operator!")((void)0); 7733 return visitBinaryOperator(OO, Args, Subobj); 7734 } 7735 7736 Result 7737 visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args, 7738 Subobject Subobj, 7739 OverloadCandidateSet *SpaceshipCandidates = nullptr) { 7740 // Note that there is no need to consider rewritten candidates here if 7741 // we've already found there is no viable 'operator<=>' candidate (and are 7742 // considering synthesizing a '<=>' from '==' and '<'). 7743 OverloadCandidateSet CandidateSet( 7744 FD->getLocation(), OverloadCandidateSet::CSK_Operator, 7745 OverloadCandidateSet::OperatorRewriteInfo( 7746 OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates)); 7747 7748 /// C++2a [class.compare.default]p1 [P2002R0]: 7749 /// [...] the defaulted function itself is never a candidate for overload 7750 /// resolution [...] 7751 CandidateSet.exclude(FD); 7752 7753 if (Args[0]->getType()->isOverloadableType()) 7754 S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args); 7755 else 7756 // FIXME: We determine whether this is a valid expression by checking to 7757 // see if there's a viable builtin operator candidate for it. That isn't 7758 // really what the rules ask us to do, but should give the right results. 7759 S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet); 7760 7761 Result R; 7762 7763 OverloadCandidateSet::iterator Best; 7764 switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) { 7765 case OR_Success: { 7766 // C++2a [class.compare.secondary]p2 [P2002R0]: 7767 // The operator function [...] is defined as deleted if [...] the 7768 // candidate selected by overload resolution is not a rewritten 7769 // candidate. 7770 if ((DCK == DefaultedComparisonKind::NotEqual || 7771 DCK == DefaultedComparisonKind::Relational) && 7772 !Best->RewriteKind) { 7773 if (Diagnose == ExplainDeleted) { 7774 S.Diag(Best->Function->getLocation(), 7775 diag::note_defaulted_comparison_not_rewritten_callee) 7776 << FD; 7777 } 7778 return Result::deleted(); 7779 } 7780 7781 // Throughout C++2a [class.compare]: if overload resolution does not 7782 // result in a usable function, the candidate function is defined as 7783 // deleted. This requires that we selected an accessible function. 7784 // 7785 // Note that this only considers the access of the function when named 7786 // within the type of the subobject, and not the access path for any 7787 // derived-to-base conversion. 7788 CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl(); 7789 if (ArgClass && Best->FoundDecl.getDecl() && 7790 Best->FoundDecl.getDecl()->isCXXClassMember()) { 7791 QualType ObjectType = Subobj.Kind == Subobject::Member 7792 ? Args[0]->getType() 7793 : S.Context.getRecordType(RD); 7794 if (!S.isMemberAccessibleForDeletion( 7795 ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc, 7796 Diagnose == ExplainDeleted 7797 ? S.PDiag(diag::note_defaulted_comparison_inaccessible) 7798 << FD << Subobj.Kind << Subobj.Decl 7799 : S.PDiag())) 7800 return Result::deleted(); 7801 } 7802 7803 bool NeedsDeducing = 7804 OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType(); 7805 7806 if (FunctionDecl *BestFD = Best->Function) { 7807 // C++2a [class.compare.default]p3 [P2002R0]: 7808 // A defaulted comparison function is constexpr-compatible if 7809 // [...] no overlod resolution performed [...] results in a 7810 // non-constexpr function. 7811 assert(!BestFD->isDeleted() && "wrong overload resolution result")((void)0); 7812 // If it's not constexpr, explain why not. 7813 if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) { 7814 if (Subobj.Kind != Subobject::CompleteObject) 7815 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr) 7816 << Subobj.Kind << Subobj.Decl; 7817 S.Diag(BestFD->getLocation(), 7818 diag::note_defaulted_comparison_not_constexpr_here); 7819 // Bail out after explaining; we don't want any more notes. 7820 return Result::deleted(); 7821 } 7822 R.Constexpr &= BestFD->isConstexpr(); 7823 7824 if (NeedsDeducing) { 7825 // If any callee has an undeduced return type, deduce it now. 7826 // FIXME: It's not clear how a failure here should be handled. For 7827 // now, we produce an eager diagnostic, because that is forward 7828 // compatible with most (all?) other reasonable options. 7829 if (BestFD->getReturnType()->isUndeducedType() && 7830 S.DeduceReturnType(BestFD, FD->getLocation(), 7831 /*Diagnose=*/false)) { 7832 // Don't produce a duplicate error when asked to explain why the 7833 // comparison is deleted: we diagnosed that when initially checking 7834 // the defaulted operator. 7835 if (Diagnose == NoDiagnostics) { 7836 S.Diag( 7837 FD->getLocation(), 7838 diag::err_defaulted_comparison_cannot_deduce_undeduced_auto) 7839 << Subobj.Kind << Subobj.Decl; 7840 S.Diag( 7841 Subobj.Loc, 7842 diag::note_defaulted_comparison_cannot_deduce_undeduced_auto) 7843 << Subobj.Kind << Subobj.Decl; 7844 S.Diag(BestFD->getLocation(), 7845 diag::note_defaulted_comparison_cannot_deduce_callee) 7846 << Subobj.Kind << Subobj.Decl; 7847 } 7848 return Result::deleted(); 7849 } 7850 auto *Info = S.Context.CompCategories.lookupInfoForType( 7851 BestFD->getCallResultType()); 7852 if (!Info) { 7853 if (Diagnose == ExplainDeleted) { 7854 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce) 7855 << Subobj.Kind << Subobj.Decl 7856 << BestFD->getCallResultType().withoutLocalFastQualifiers(); 7857 S.Diag(BestFD->getLocation(), 7858 diag::note_defaulted_comparison_cannot_deduce_callee) 7859 << Subobj.Kind << Subobj.Decl; 7860 } 7861 return Result::deleted(); 7862 } 7863 R.Category = Info->Kind; 7864 } 7865 } else { 7866 QualType T = Best->BuiltinParamTypes[0]; 7867 assert(T == Best->BuiltinParamTypes[1] &&((void)0) 7868 "builtin comparison for different types?")((void)0); 7869 assert(Best->BuiltinParamTypes[2].isNull() &&((void)0) 7870 "invalid builtin comparison")((void)0); 7871 7872 if (NeedsDeducing) { 7873 Optional<ComparisonCategoryType> Cat = 7874 getComparisonCategoryForBuiltinCmp(T); 7875 assert(Cat && "no category for builtin comparison?")((void)0); 7876 R.Category = *Cat; 7877 } 7878 } 7879 7880 // Note that we might be rewriting to a different operator. That call is 7881 // not considered until we come to actually build the comparison function. 7882 break; 7883 } 7884 7885 case OR_Ambiguous: 7886 if (Diagnose == ExplainDeleted) { 7887 unsigned Kind = 0; 7888 if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship) 7889 Kind = OO == OO_EqualEqual ? 1 : 2; 7890 CandidateSet.NoteCandidates( 7891 PartialDiagnosticAt( 7892 Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous) 7893 << FD << Kind << Subobj.Kind << Subobj.Decl), 7894 S, OCD_AmbiguousCandidates, Args); 7895 } 7896 R = Result::deleted(); 7897 break; 7898 7899 case OR_Deleted: 7900 if (Diagnose == ExplainDeleted) { 7901 if ((DCK == DefaultedComparisonKind::NotEqual || 7902 DCK == DefaultedComparisonKind::Relational) && 7903 !Best->RewriteKind) { 7904 S.Diag(Best->Function->getLocation(), 7905 diag::note_defaulted_comparison_not_rewritten_callee) 7906 << FD; 7907 } else { 7908 S.Diag(Subobj.Loc, 7909 diag::note_defaulted_comparison_calls_deleted) 7910 << FD << Subobj.Kind << Subobj.Decl; 7911 S.NoteDeletedFunction(Best->Function); 7912 } 7913 } 7914 R = Result::deleted(); 7915 break; 7916 7917 case OR_No_Viable_Function: 7918 // If there's no usable candidate, we're done unless we can rewrite a 7919 // '<=>' in terms of '==' and '<'. 7920 if (OO == OO_Spaceship && 7921 S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) { 7922 // For any kind of comparison category return type, we need a usable 7923 // '==' and a usable '<'. 7924 if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj, 7925 &CandidateSet))) 7926 R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet)); 7927 break; 7928 } 7929 7930 if (Diagnose == ExplainDeleted) { 7931 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function) 7932 << FD << Subobj.Kind << Subobj.Decl; 7933 7934 // For a three-way comparison, list both the candidates for the 7935 // original operator and the candidates for the synthesized operator. 7936 if (SpaceshipCandidates) { 7937 SpaceshipCandidates->NoteCandidates( 7938 S, Args, 7939 SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates, 7940 Args, FD->getLocation())); 7941 S.Diag(Subobj.Loc, 7942 diag::note_defaulted_comparison_no_viable_function_synthesized) 7943 << (OO == OO_EqualEqual ? 0 : 1); 7944 } 7945 7946 CandidateSet.NoteCandidates( 7947 S, Args, 7948 CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args, 7949 FD->getLocation())); 7950 } 7951 R = Result::deleted(); 7952 break; 7953 } 7954 7955 return R; 7956 } 7957}; 7958 7959/// A list of statements. 7960struct StmtListResult { 7961 bool IsInvalid = false; 7962 llvm::SmallVector<Stmt*, 16> Stmts; 7963 7964 bool add(const StmtResult &S) { 7965 IsInvalid |= S.isInvalid(); 7966 if (IsInvalid) 7967 return true; 7968 Stmts.push_back(S.get()); 7969 return false; 7970 } 7971}; 7972 7973/// A visitor over the notional body of a defaulted comparison that synthesizes 7974/// the actual body. 7975class DefaultedComparisonSynthesizer 7976 : public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer, 7977 StmtListResult, StmtResult, 7978 std::pair<ExprResult, ExprResult>> { 7979 SourceLocation Loc; 7980 unsigned ArrayDepth = 0; 7981 7982public: 7983 using Base = DefaultedComparisonVisitor; 7984 using ExprPair = std::pair<ExprResult, ExprResult>; 7985 7986 friend Base; 7987 7988 DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD, 7989 DefaultedComparisonKind DCK, 7990 SourceLocation BodyLoc) 7991 : Base(S, RD, FD, DCK), Loc(BodyLoc) {} 7992 7993 /// Build a suitable function body for this defaulted comparison operator. 7994 StmtResult build() { 7995 Sema::CompoundScopeRAII CompoundScope(S); 7996 7997 StmtListResult Stmts = visit(); 7998 if (Stmts.IsInvalid) 7999 return StmtError(); 8000 8001 ExprResult RetVal; 8002 switch (DCK) { 8003 case DefaultedComparisonKind::None: 8004 llvm_unreachable("not a defaulted comparison")__builtin_unreachable(); 8005 8006 case DefaultedComparisonKind::Equal: { 8007 // C++2a [class.eq]p3: 8008 // [...] compar[e] the corresponding elements [...] until the first 8009 // index i where xi == yi yields [...] false. If no such index exists, 8010 // V is true. Otherwise, V is false. 8011 // 8012 // Join the comparisons with '&&'s and return the result. Use a right 8013 // fold (traversing the conditions right-to-left), because that 8014 // short-circuits more naturally. 8015 auto OldStmts = std::move(Stmts.Stmts); 8016 Stmts.Stmts.clear(); 8017 ExprResult CmpSoFar; 8018 // Finish a particular comparison chain. 8019 auto FinishCmp = [&] { 8020 if (Expr *Prior = CmpSoFar.get()) { 8021 // Convert the last expression to 'return ...;' 8022 if (RetVal.isUnset() && Stmts.Stmts.empty()) 8023 RetVal = CmpSoFar; 8024 // Convert any prior comparison to 'if (!(...)) return false;' 8025 else if (Stmts.add(buildIfNotCondReturnFalse(Prior))) 8026 return true; 8027 CmpSoFar = ExprResult(); 8028 } 8029 return false; 8030 }; 8031 for (Stmt *EAsStmt : llvm::reverse(OldStmts)) { 8032 Expr *E = dyn_cast<Expr>(EAsStmt); 8033 if (!E) { 8034 // Found an array comparison. 8035 if (FinishCmp() || Stmts.add(EAsStmt)) 8036 return StmtError(); 8037 continue; 8038 } 8039 8040 if (CmpSoFar.isUnset()) { 8041 CmpSoFar = E; 8042 continue; 8043 } 8044 CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get()); 8045 if (CmpSoFar.isInvalid()) 8046 return StmtError(); 8047 } 8048 if (FinishCmp()) 8049 return StmtError(); 8050 std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end()); 8051 // If no such index exists, V is true. 8052 if (RetVal.isUnset()) 8053 RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true); 8054 break; 8055 } 8056 8057 case DefaultedComparisonKind::ThreeWay: { 8058 // Per C++2a [class.spaceship]p3, as a fallback add: 8059 // return static_cast<R>(std::strong_ordering::equal); 8060 QualType StrongOrdering = S.CheckComparisonCategoryType( 8061 ComparisonCategoryType::StrongOrdering, Loc, 8062 Sema::ComparisonCategoryUsage::DefaultedOperator); 8063 if (StrongOrdering.isNull()) 8064 return StmtError(); 8065 VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering) 8066 .getValueInfo(ComparisonCategoryResult::Equal) 8067 ->VD; 8068 RetVal = getDecl(EqualVD); 8069 if (RetVal.isInvalid()) 8070 return StmtError(); 8071 RetVal = buildStaticCastToR(RetVal.get()); 8072 break; 8073 } 8074 8075 case DefaultedComparisonKind::NotEqual: 8076 case DefaultedComparisonKind::Relational: 8077 RetVal = cast<Expr>(Stmts.Stmts.pop_back_val()); 8078 break; 8079 } 8080 8081 // Build the final return statement. 8082 if (RetVal.isInvalid()) 8083 return StmtError(); 8084 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get()); 8085 if (ReturnStmt.isInvalid()) 8086 return StmtError(); 8087 Stmts.Stmts.push_back(ReturnStmt.get()); 8088 8089 return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false); 8090 } 8091 8092private: 8093 ExprResult getDecl(ValueDecl *VD) { 8094 return S.BuildDeclarationNameExpr( 8095 CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD); 8096 } 8097 8098 ExprResult getParam(unsigned I) { 8099 ParmVarDecl *PD = FD->getParamDecl(I); 8100 return getDecl(PD); 8101 } 8102 8103 ExprPair getCompleteObject() { 8104 unsigned Param = 0; 8105 ExprResult LHS; 8106 if (isa<CXXMethodDecl>(FD)) { 8107 // LHS is '*this'. 8108 LHS = S.ActOnCXXThis(Loc); 8109 if (!LHS.isInvalid()) 8110 LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get()); 8111 } else { 8112 LHS = getParam(Param++); 8113 } 8114 ExprResult RHS = getParam(Param++); 8115 assert(Param == FD->getNumParams())((void)0); 8116 return {LHS, RHS}; 8117 } 8118 8119 ExprPair getBase(CXXBaseSpecifier *Base) { 8120 ExprPair Obj = getCompleteObject(); 8121 if (Obj.first.isInvalid() || Obj.second.isInvalid()) 8122 return {ExprError(), ExprError()}; 8123 CXXCastPath Path = {Base}; 8124 return {S.ImpCastExprToType(Obj.first.get(), Base->getType(), 8125 CK_DerivedToBase, VK_LValue, &Path), 8126 S.ImpCastExprToType(Obj.second.get(), Base->getType(), 8127 CK_DerivedToBase, VK_LValue, &Path)}; 8128 } 8129 8130 ExprPair getField(FieldDecl *Field) { 8131 ExprPair Obj = getCompleteObject(); 8132 if (Obj.first.isInvalid() || Obj.second.isInvalid()) 8133 return {ExprError(), ExprError()}; 8134 8135 DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess()); 8136 DeclarationNameInfo NameInfo(Field->getDeclName(), Loc); 8137 return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc, 8138 CXXScopeSpec(), Field, Found, NameInfo), 8139 S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc, 8140 CXXScopeSpec(), Field, Found, NameInfo)}; 8141 } 8142 8143 // FIXME: When expanding a subobject, register a note in the code synthesis 8144 // stack to say which subobject we're comparing. 8145 8146 StmtResult buildIfNotCondReturnFalse(ExprResult Cond) { 8147 if (Cond.isInvalid()) 8148 return StmtError(); 8149 8150 ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get()); 8151 if (NotCond.isInvalid()) 8152 return StmtError(); 8153 8154 ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false); 8155 assert(!False.isInvalid() && "should never fail")((void)0); 8156 StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get()); 8157 if (ReturnFalse.isInvalid()) 8158 return StmtError(); 8159 8160 return S.ActOnIfStmt(Loc, false, Loc, nullptr, 8161 S.ActOnCondition(nullptr, Loc, NotCond.get(), 8162 Sema::ConditionKind::Boolean), 8163 Loc, ReturnFalse.get(), SourceLocation(), nullptr); 8164 } 8165 8166 StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size, 8167 ExprPair Subobj) { 8168 QualType SizeType = S.Context.getSizeType(); 8169 Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType)); 8170 8171 // Build 'size_t i$n = 0'. 8172 IdentifierInfo *IterationVarName = nullptr; 8173 { 8174 SmallString<8> Str; 8175 llvm::raw_svector_ostream OS(Str); 8176 OS << "i" << ArrayDepth; 8177 IterationVarName = &S.Context.Idents.get(OS.str()); 8178 } 8179 VarDecl *IterationVar = VarDecl::Create( 8180 S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType, 8181 S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None); 8182 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0); 8183 IterationVar->setInit( 8184 IntegerLiteral::Create(S.Context, Zero, SizeType, Loc)); 8185 Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc); 8186 8187 auto IterRef = [&] { 8188 ExprResult Ref = S.BuildDeclarationNameExpr( 8189 CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc), 8190 IterationVar); 8191 assert(!Ref.isInvalid() && "can't reference our own variable?")((void)0); 8192 return Ref.get(); 8193 }; 8194 8195 // Build 'i$n != Size'. 8196 ExprResult Cond = S.CreateBuiltinBinOp( 8197 Loc, BO_NE, IterRef(), 8198 IntegerLiteral::Create(S.Context, Size, SizeType, Loc)); 8199 assert(!Cond.isInvalid() && "should never fail")((void)0); 8200 8201 // Build '++i$n'. 8202 ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef()); 8203 assert(!Inc.isInvalid() && "should never fail")((void)0); 8204 8205 // Build 'a[i$n]' and 'b[i$n]'. 8206 auto Index = [&](ExprResult E) { 8207 if (E.isInvalid()) 8208 return ExprError(); 8209 return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc); 8210 }; 8211 Subobj.first = Index(Subobj.first); 8212 Subobj.second = Index(Subobj.second); 8213 8214 // Compare the array elements. 8215 ++ArrayDepth; 8216 StmtResult Substmt = visitSubobject(Type, Subobj); 8217 --ArrayDepth; 8218 8219 if (Substmt.isInvalid()) 8220 return StmtError(); 8221 8222 // For the inner level of an 'operator==', build 'if (!cmp) return false;'. 8223 // For outer levels or for an 'operator<=>' we already have a suitable 8224 // statement that returns as necessary. 8225 if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) { 8226 assert(DCK == DefaultedComparisonKind::Equal &&((void)0) 8227 "should have non-expression statement")((void)0); 8228 Substmt = buildIfNotCondReturnFalse(ElemCmp); 8229 if (Substmt.isInvalid()) 8230 return StmtError(); 8231 } 8232 8233 // Build 'for (...) ...' 8234 return S.ActOnForStmt(Loc, Loc, Init, 8235 S.ActOnCondition(nullptr, Loc, Cond.get(), 8236 Sema::ConditionKind::Boolean), 8237 S.MakeFullDiscardedValueExpr(Inc.get()), Loc, 8238 Substmt.get()); 8239 } 8240 8241 StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) { 8242 if (Obj.first.isInvalid() || Obj.second.isInvalid()) 8243 return StmtError(); 8244 8245 OverloadedOperatorKind OO = FD->getOverloadedOperator(); 8246 BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO); 8247 ExprResult Op; 8248 if (Type->isOverloadableType()) 8249 Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(), 8250 Obj.second.get(), /*PerformADL=*/true, 8251 /*AllowRewrittenCandidates=*/true, FD); 8252 else 8253 Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get()); 8254 if (Op.isInvalid()) 8255 return StmtError(); 8256 8257 switch (DCK) { 8258 case DefaultedComparisonKind::None: 8259 llvm_unreachable("not a defaulted comparison")__builtin_unreachable(); 8260 8261 case DefaultedComparisonKind::Equal: 8262 // Per C++2a [class.eq]p2, each comparison is individually contextually 8263 // converted to bool. 8264 Op = S.PerformContextuallyConvertToBool(Op.get()); 8265 if (Op.isInvalid()) 8266 return StmtError(); 8267 return Op.get(); 8268 8269 case DefaultedComparisonKind::ThreeWay: { 8270 // Per C++2a [class.spaceship]p3, form: 8271 // if (R cmp = static_cast<R>(op); cmp != 0) 8272 // return cmp; 8273 QualType R = FD->getReturnType(); 8274 Op = buildStaticCastToR(Op.get()); 8275 if (Op.isInvalid()) 8276 return StmtError(); 8277 8278 // R cmp = ...; 8279 IdentifierInfo *Name = &S.Context.Idents.get("cmp"); 8280 VarDecl *VD = 8281 VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R, 8282 S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None); 8283 S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false); 8284 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc); 8285 8286 // cmp != 0 8287 ExprResult VDRef = getDecl(VD); 8288 if (VDRef.isInvalid()) 8289 return StmtError(); 8290 llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0); 8291 Expr *Zero = 8292 IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc); 8293 ExprResult Comp; 8294 if (VDRef.get()->getType()->isOverloadableType()) 8295 Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true, 8296 true, FD); 8297 else 8298 Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero); 8299 if (Comp.isInvalid()) 8300 return StmtError(); 8301 Sema::ConditionResult Cond = S.ActOnCondition( 8302 nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean); 8303 if (Cond.isInvalid()) 8304 return StmtError(); 8305 8306 // return cmp; 8307 VDRef = getDecl(VD); 8308 if (VDRef.isInvalid()) 8309 return StmtError(); 8310 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get()); 8311 if (ReturnStmt.isInvalid()) 8312 return StmtError(); 8313 8314 // if (...) 8315 return S.ActOnIfStmt(Loc, /*IsConstexpr=*/false, Loc, InitStmt, Cond, Loc, 8316 ReturnStmt.get(), 8317 /*ElseLoc=*/SourceLocation(), /*Else=*/nullptr); 8318 } 8319 8320 case DefaultedComparisonKind::NotEqual: 8321 case DefaultedComparisonKind::Relational: 8322 // C++2a [class.compare.secondary]p2: 8323 // Otherwise, the operator function yields x @ y. 8324 return Op.get(); 8325 } 8326 llvm_unreachable("")__builtin_unreachable(); 8327 } 8328 8329 /// Build "static_cast<R>(E)". 8330 ExprResult buildStaticCastToR(Expr *E) { 8331 QualType R = FD->getReturnType(); 8332 assert(!R->isUndeducedType() && "type should have been deduced already")((void)0); 8333 8334 // Don't bother forming a no-op cast in the common case. 8335 if (E->isPRValue() && S.Context.hasSameType(E->getType(), R)) 8336 return E; 8337 return S.BuildCXXNamedCast(Loc, tok::kw_static_cast, 8338 S.Context.getTrivialTypeSourceInfo(R, Loc), E, 8339 SourceRange(Loc, Loc), SourceRange(Loc, Loc)); 8340 } 8341}; 8342} 8343 8344/// Perform the unqualified lookups that might be needed to form a defaulted 8345/// comparison function for the given operator. 8346static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S, 8347 UnresolvedSetImpl &Operators, 8348 OverloadedOperatorKind Op) { 8349 auto Lookup = [&](OverloadedOperatorKind OO) { 8350 Self.LookupOverloadedOperatorName(OO, S, Operators); 8351 }; 8352 8353 // Every defaulted operator looks up itself. 8354 Lookup(Op); 8355 // ... and the rewritten form of itself, if any. 8356 if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op)) 8357 Lookup(ExtraOp); 8358 8359 // For 'operator<=>', we also form a 'cmp != 0' expression, and might 8360 // synthesize a three-way comparison from '<' and '=='. In a dependent 8361 // context, we also need to look up '==' in case we implicitly declare a 8362 // defaulted 'operator=='. 8363 if (Op == OO_Spaceship) { 8364 Lookup(OO_ExclaimEqual); 8365 Lookup(OO_Less); 8366 Lookup(OO_EqualEqual); 8367 } 8368} 8369 8370bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD, 8371 DefaultedComparisonKind DCK) { 8372 assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison")((void)0); 8373 8374 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext()); 8375 assert(RD && "defaulted comparison is not defaulted in a class")((void)0); 8376 8377 // Perform any unqualified lookups we're going to need to default this 8378 // function. 8379 if (S) { 8380 UnresolvedSet<32> Operators; 8381 lookupOperatorsForDefaultedComparison(*this, S, Operators, 8382 FD->getOverloadedOperator()); 8383 FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create( 8384 Context, Operators.pairs())); 8385 } 8386 8387 // C++2a [class.compare.default]p1: 8388 // A defaulted comparison operator function for some class C shall be a 8389 // non-template function declared in the member-specification of C that is 8390 // -- a non-static const member of C having one parameter of type 8391 // const C&, or 8392 // -- a friend of C having two parameters of type const C& or two 8393 // parameters of type C. 8394 QualType ExpectedParmType1 = Context.getRecordType(RD); 8395 QualType ExpectedParmType2 = 8396 Context.getLValueReferenceType(ExpectedParmType1.withConst()); 8397 if (isa<CXXMethodDecl>(FD)) 8398 ExpectedParmType1 = ExpectedParmType2; 8399 for (const ParmVarDecl *Param : FD->parameters()) { 8400 if (!Param->getType()->isDependentType() && 8401 !Context.hasSameType(Param->getType(), ExpectedParmType1) && 8402 !Context.hasSameType(Param->getType(), ExpectedParmType2)) { 8403 // Don't diagnose an implicit 'operator=='; we will have diagnosed the 8404 // corresponding defaulted 'operator<=>' already. 8405 if (!FD->isImplicit()) { 8406 Diag(FD->getLocation(), diag::err_defaulted_comparison_param) 8407 << (int)DCK << Param->getType() << ExpectedParmType1 8408 << !isa<CXXMethodDecl>(FD) 8409 << ExpectedParmType2 << Param->getSourceRange(); 8410 } 8411 return true; 8412 } 8413 } 8414 if (FD->getNumParams() == 2 && 8415 !Context.hasSameType(FD->getParamDecl(0)->getType(), 8416 FD->getParamDecl(1)->getType())) { 8417 if (!FD->isImplicit()) { 8418 Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch) 8419 << (int)DCK 8420 << FD->getParamDecl(0)->getType() 8421 << FD->getParamDecl(0)->getSourceRange() 8422 << FD->getParamDecl(1)->getType() 8423 << FD->getParamDecl(1)->getSourceRange(); 8424 } 8425 return true; 8426 } 8427 8428 // ... non-static const member ... 8429 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) { 8430 assert(!MD->isStatic() && "comparison function cannot be a static member")((void)0); 8431 if (!MD->isConst()) { 8432 SourceLocation InsertLoc; 8433 if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc()) 8434 InsertLoc = getLocForEndOfToken(Loc.getRParenLoc()); 8435 // Don't diagnose an implicit 'operator=='; we will have diagnosed the 8436 // corresponding defaulted 'operator<=>' already. 8437 if (!MD->isImplicit()) { 8438 Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const) 8439 << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const"); 8440 } 8441 8442 // Add the 'const' to the type to recover. 8443 const auto *FPT = MD->getType()->castAs<FunctionProtoType>(); 8444 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 8445 EPI.TypeQuals.addConst(); 8446 MD->setType(Context.getFunctionType(FPT->getReturnType(), 8447 FPT->getParamTypes(), EPI)); 8448 } 8449 } else { 8450 // A non-member function declared in a class must be a friend. 8451 assert(FD->getFriendObjectKind() && "expected a friend declaration")((void)0); 8452 } 8453 8454 // C++2a [class.eq]p1, [class.rel]p1: 8455 // A [defaulted comparison other than <=>] shall have a declared return 8456 // type bool. 8457 if (DCK != DefaultedComparisonKind::ThreeWay && 8458 !FD->getDeclaredReturnType()->isDependentType() && 8459 !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) { 8460 Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool) 8461 << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy 8462 << FD->getReturnTypeSourceRange(); 8463 return true; 8464 } 8465 // C++2a [class.spaceship]p2 [P2002R0]: 8466 // Let R be the declared return type [...]. If R is auto, [...]. Otherwise, 8467 // R shall not contain a placeholder type. 8468 if (DCK == DefaultedComparisonKind::ThreeWay && 8469 FD->getDeclaredReturnType()->getContainedDeducedType() && 8470 !Context.hasSameType(FD->getDeclaredReturnType(), 8471 Context.getAutoDeductType())) { 8472 Diag(FD->getLocation(), 8473 diag::err_defaulted_comparison_deduced_return_type_not_auto) 8474 << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy 8475 << FD->getReturnTypeSourceRange(); 8476 return true; 8477 } 8478 8479 // For a defaulted function in a dependent class, defer all remaining checks 8480 // until instantiation. 8481 if (RD->isDependentType()) 8482 return false; 8483 8484 // Determine whether the function should be defined as deleted. 8485 DefaultedComparisonInfo Info = 8486 DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit(); 8487 8488 bool First = FD == FD->getCanonicalDecl(); 8489 8490 // If we want to delete the function, then do so; there's nothing else to 8491 // check in that case. 8492 if (Info.Deleted) { 8493 if (!First) { 8494 // C++11 [dcl.fct.def.default]p4: 8495 // [For a] user-provided explicitly-defaulted function [...] if such a 8496 // function is implicitly defined as deleted, the program is ill-formed. 8497 // 8498 // This is really just a consequence of the general rule that you can 8499 // only delete a function on its first declaration. 8500 Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes) 8501 << FD->isImplicit() << (int)DCK; 8502 DefaultedComparisonAnalyzer(*this, RD, FD, DCK, 8503 DefaultedComparisonAnalyzer::ExplainDeleted) 8504 .visit(); 8505 return true; 8506 } 8507 8508 SetDeclDeleted(FD, FD->getLocation()); 8509 if (!inTemplateInstantiation() && !FD->isImplicit()) { 8510 Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted) 8511 << (int)DCK; 8512 DefaultedComparisonAnalyzer(*this, RD, FD, DCK, 8513 DefaultedComparisonAnalyzer::ExplainDeleted) 8514 .visit(); 8515 } 8516 return false; 8517 } 8518 8519 // C++2a [class.spaceship]p2: 8520 // The return type is deduced as the common comparison type of R0, R1, ... 8521 if (DCK == DefaultedComparisonKind::ThreeWay && 8522 FD->getDeclaredReturnType()->isUndeducedAutoType()) { 8523 SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin(); 8524 if (RetLoc.isInvalid()) 8525 RetLoc = FD->getBeginLoc(); 8526 // FIXME: Should we really care whether we have the complete type and the 8527 // 'enumerator' constants here? A forward declaration seems sufficient. 8528 QualType Cat = CheckComparisonCategoryType( 8529 Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator); 8530 if (Cat.isNull()) 8531 return true; 8532 Context.adjustDeducedFunctionResultType( 8533 FD, SubstAutoType(FD->getDeclaredReturnType(), Cat)); 8534 } 8535 8536 // C++2a [dcl.fct.def.default]p3 [P2002R0]: 8537 // An explicitly-defaulted function that is not defined as deleted may be 8538 // declared constexpr or consteval only if it is constexpr-compatible. 8539 // C++2a [class.compare.default]p3 [P2002R0]: 8540 // A defaulted comparison function is constexpr-compatible if it satisfies 8541 // the requirements for a constexpr function [...] 8542 // The only relevant requirements are that the parameter and return types are 8543 // literal types. The remaining conditions are checked by the analyzer. 8544 if (FD->isConstexpr()) { 8545 if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) && 8546 CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) && 8547 !Info.Constexpr) { 8548 Diag(FD->getBeginLoc(), 8549 diag::err_incorrect_defaulted_comparison_constexpr) 8550 << FD->isImplicit() << (int)DCK << FD->isConsteval(); 8551 DefaultedComparisonAnalyzer(*this, RD, FD, DCK, 8552 DefaultedComparisonAnalyzer::ExplainConstexpr) 8553 .visit(); 8554 } 8555 } 8556 8557 // C++2a [dcl.fct.def.default]p3 [P2002R0]: 8558 // If a constexpr-compatible function is explicitly defaulted on its first 8559 // declaration, it is implicitly considered to be constexpr. 8560 // FIXME: Only applying this to the first declaration seems problematic, as 8561 // simple reorderings can affect the meaning of the program. 8562 if (First && !FD->isConstexpr() && Info.Constexpr) 8563 FD->setConstexprKind(ConstexprSpecKind::Constexpr); 8564 8565 // C++2a [except.spec]p3: 8566 // If a declaration of a function does not have a noexcept-specifier 8567 // [and] is defaulted on its first declaration, [...] the exception 8568 // specification is as specified below 8569 if (FD->getExceptionSpecType() == EST_None) { 8570 auto *FPT = FD->getType()->castAs<FunctionProtoType>(); 8571 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 8572 EPI.ExceptionSpec.Type = EST_Unevaluated; 8573 EPI.ExceptionSpec.SourceDecl = FD; 8574 FD->setType(Context.getFunctionType(FPT->getReturnType(), 8575 FPT->getParamTypes(), EPI)); 8576 } 8577 8578 return false; 8579} 8580 8581void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD, 8582 FunctionDecl *Spaceship) { 8583 Sema::CodeSynthesisContext Ctx; 8584 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison; 8585 Ctx.PointOfInstantiation = Spaceship->getEndLoc(); 8586 Ctx.Entity = Spaceship; 8587 pushCodeSynthesisContext(Ctx); 8588 8589 if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship)) 8590 EqualEqual->setImplicit(); 8591 8592 popCodeSynthesisContext(); 8593} 8594 8595void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD, 8596 DefaultedComparisonKind DCK) { 8597 assert(FD->isDefaulted() && !FD->isDeleted() &&((void)0) 8598 !FD->doesThisDeclarationHaveABody())((void)0); 8599 if (FD->willHaveBody() || FD->isInvalidDecl()) 8600 return; 8601 8602 SynthesizedFunctionScope Scope(*this, FD); 8603 8604 // Add a context note for diagnostics produced after this point. 8605 Scope.addContextNote(UseLoc); 8606 8607 { 8608 // Build and set up the function body. 8609 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent()); 8610 SourceLocation BodyLoc = 8611 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation(); 8612 StmtResult Body = 8613 DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build(); 8614 if (Body.isInvalid()) { 8615 FD->setInvalidDecl(); 8616 return; 8617 } 8618 FD->setBody(Body.get()); 8619 FD->markUsed(Context); 8620 } 8621 8622 // The exception specification is needed because we are defining the 8623 // function. Note that this will reuse the body we just built. 8624 ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>()); 8625 8626 if (ASTMutationListener *L = getASTMutationListener()) 8627 L->CompletedImplicitDefinition(FD); 8628} 8629 8630static Sema::ImplicitExceptionSpecification 8631ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc, 8632 FunctionDecl *FD, 8633 Sema::DefaultedComparisonKind DCK) { 8634 ComputingExceptionSpec CES(S, FD, Loc); 8635 Sema::ImplicitExceptionSpecification ExceptSpec(S); 8636 8637 if (FD->isInvalidDecl()) 8638 return ExceptSpec; 8639 8640 // The common case is that we just defined the comparison function. In that 8641 // case, just look at whether the body can throw. 8642 if (FD->hasBody()) { 8643 ExceptSpec.CalledStmt(FD->getBody()); 8644 } else { 8645 // Otherwise, build a body so we can check it. This should ideally only 8646 // happen when we're not actually marking the function referenced. (This is 8647 // only really important for efficiency: we don't want to build and throw 8648 // away bodies for comparison functions more than we strictly need to.) 8649 8650 // Pretend to synthesize the function body in an unevaluated context. 8651 // Note that we can't actually just go ahead and define the function here: 8652 // we are not permitted to mark its callees as referenced. 8653 Sema::SynthesizedFunctionScope Scope(S, FD); 8654 EnterExpressionEvaluationContext Context( 8655 S, Sema::ExpressionEvaluationContext::Unevaluated); 8656 8657 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent()); 8658 SourceLocation BodyLoc = 8659 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation(); 8660 StmtResult Body = 8661 DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build(); 8662 if (!Body.isInvalid()) 8663 ExceptSpec.CalledStmt(Body.get()); 8664 8665 // FIXME: Can we hold onto this body and just transform it to potentially 8666 // evaluated when we're asked to define the function rather than rebuilding 8667 // it? Either that, or we should only build the bits of the body that we 8668 // need (the expressions, not the statements). 8669 } 8670 8671 return ExceptSpec; 8672} 8673 8674void Sema::CheckDelayedMemberExceptionSpecs() { 8675 decltype(DelayedOverridingExceptionSpecChecks) Overriding; 8676 decltype(DelayedEquivalentExceptionSpecChecks) Equivalent; 8677 8678 std::swap(Overriding, DelayedOverridingExceptionSpecChecks); 8679 std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks); 8680 8681 // Perform any deferred checking of exception specifications for virtual 8682 // destructors. 8683 for (auto &Check : Overriding) 8684 CheckOverridingFunctionExceptionSpec(Check.first, Check.second); 8685 8686 // Perform any deferred checking of exception specifications for befriended 8687 // special members. 8688 for (auto &Check : Equivalent) 8689 CheckEquivalentExceptionSpec(Check.second, Check.first); 8690} 8691 8692namespace { 8693/// CRTP base class for visiting operations performed by a special member 8694/// function (or inherited constructor). 8695template<typename Derived> 8696struct SpecialMemberVisitor { 8697 Sema &S; 8698 CXXMethodDecl *MD; 8699 Sema::CXXSpecialMember CSM; 8700 Sema::InheritedConstructorInfo *ICI; 8701 8702 // Properties of the special member, computed for convenience. 8703 bool IsConstructor = false, IsAssignment = false, ConstArg = false; 8704 8705 SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, 8706 Sema::InheritedConstructorInfo *ICI) 8707 : S(S), MD(MD), CSM(CSM), ICI(ICI) { 8708 switch (CSM) { 8709 case Sema::CXXDefaultConstructor: 8710 case Sema::CXXCopyConstructor: 8711 case Sema::CXXMoveConstructor: 8712 IsConstructor = true; 8713 break; 8714 case Sema::CXXCopyAssignment: 8715 case Sema::CXXMoveAssignment: 8716 IsAssignment = true; 8717 break; 8718 case Sema::CXXDestructor: 8719 break; 8720 case Sema::CXXInvalid: 8721 llvm_unreachable("invalid special member kind")__builtin_unreachable(); 8722 } 8723 8724 if (MD->getNumParams()) { 8725 if (const ReferenceType *RT = 8726 MD->getParamDecl(0)->getType()->getAs<ReferenceType>()) 8727 ConstArg = RT->getPointeeType().isConstQualified(); 8728 } 8729 } 8730 8731 Derived &getDerived() { return static_cast<Derived&>(*this); } 8732 8733 /// Is this a "move" special member? 8734 bool isMove() const { 8735 return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment; 8736 } 8737 8738 /// Look up the corresponding special member in the given class. 8739 Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class, 8740 unsigned Quals, bool IsMutable) { 8741 return lookupCallFromSpecialMember(S, Class, CSM, Quals, 8742 ConstArg && !IsMutable); 8743 } 8744 8745 /// Look up the constructor for the specified base class to see if it's 8746 /// overridden due to this being an inherited constructor. 8747 Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) { 8748 if (!ICI) 8749 return {}; 8750 assert(CSM == Sema::CXXDefaultConstructor)((void)0); 8751 auto *BaseCtor = 8752 cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor(); 8753 if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first) 8754 return MD; 8755 return {}; 8756 } 8757 8758 /// A base or member subobject. 8759 typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject; 8760 8761 /// Get the location to use for a subobject in diagnostics. 8762 static SourceLocation getSubobjectLoc(Subobject Subobj) { 8763 // FIXME: For an indirect virtual base, the direct base leading to 8764 // the indirect virtual base would be a more useful choice. 8765 if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>()) 8766 return B->getBaseTypeLoc(); 8767 else 8768 return Subobj.get<FieldDecl*>()->getLocation(); 8769 } 8770 8771 enum BasesToVisit { 8772 /// Visit all non-virtual (direct) bases. 8773 VisitNonVirtualBases, 8774 /// Visit all direct bases, virtual or not. 8775 VisitDirectBases, 8776 /// Visit all non-virtual bases, and all virtual bases if the class 8777 /// is not abstract. 8778 VisitPotentiallyConstructedBases, 8779 /// Visit all direct or virtual bases. 8780 VisitAllBases 8781 }; 8782 8783 // Visit the bases and members of the class. 8784 bool visit(BasesToVisit Bases) { 8785 CXXRecordDecl *RD = MD->getParent(); 8786 8787 if (Bases == VisitPotentiallyConstructedBases) 8788 Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases; 8789 8790 for (auto &B : RD->bases()) 8791 if ((Bases == VisitDirectBases || !B.isVirtual()) && 8792 getDerived().visitBase(&B)) 8793 return true; 8794 8795 if (Bases == VisitAllBases) 8796 for (auto &B : RD->vbases()) 8797 if (getDerived().visitBase(&B)) 8798 return true; 8799 8800 for (auto *F : RD->fields()) 8801 if (!F->isInvalidDecl() && !F->isUnnamedBitfield() && 8802 getDerived().visitField(F)) 8803 return true; 8804 8805 return false; 8806 } 8807}; 8808} 8809 8810namespace { 8811struct SpecialMemberDeletionInfo 8812 : SpecialMemberVisitor<SpecialMemberDeletionInfo> { 8813 bool Diagnose; 8814 8815 SourceLocation Loc; 8816 8817 bool AllFieldsAreConst; 8818 8819 SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD, 8820 Sema::CXXSpecialMember CSM, 8821 Sema::InheritedConstructorInfo *ICI, bool Diagnose) 8822 : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose), 8823 Loc(MD->getLocation()), AllFieldsAreConst(true) {} 8824 8825 bool inUnion() const { return MD->getParent()->isUnion(); } 8826 8827 Sema::CXXSpecialMember getEffectiveCSM() { 8828 return ICI ? Sema::CXXInvalid : CSM; 8829 } 8830 8831 bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType); 8832 8833 bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); } 8834 bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); } 8835 8836 bool shouldDeleteForBase(CXXBaseSpecifier *Base); 8837 bool shouldDeleteForField(FieldDecl *FD); 8838 bool shouldDeleteForAllConstMembers(); 8839 8840 bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj, 8841 unsigned Quals); 8842 bool shouldDeleteForSubobjectCall(Subobject Subobj, 8843 Sema::SpecialMemberOverloadResult SMOR, 8844 bool IsDtorCallInCtor); 8845 8846 bool isAccessible(Subobject Subobj, CXXMethodDecl *D); 8847}; 8848} 8849 8850/// Is the given special member inaccessible when used on the given 8851/// sub-object. 8852bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj, 8853 CXXMethodDecl *target) { 8854 /// If we're operating on a base class, the object type is the 8855 /// type of this special member. 8856 QualType objectTy; 8857 AccessSpecifier access = target->getAccess(); 8858 if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) { 8859 objectTy = S.Context.getTypeDeclType(MD->getParent()); 8860 access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access); 8861 8862 // If we're operating on a field, the object type is the type of the field. 8863 } else { 8864 objectTy = S.Context.getTypeDeclType(target->getParent()); 8865 } 8866 8867 return S.isMemberAccessibleForDeletion( 8868 target->getParent(), DeclAccessPair::make(target, access), objectTy); 8869} 8870 8871/// Check whether we should delete a special member due to the implicit 8872/// definition containing a call to a special member of a subobject. 8873bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall( 8874 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR, 8875 bool IsDtorCallInCtor) { 8876 CXXMethodDecl *Decl = SMOR.getMethod(); 8877 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>(); 8878 8879 int DiagKind = -1; 8880 8881 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted) 8882 DiagKind = !Decl ? 0 : 1; 8883 else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) 8884 DiagKind = 2; 8885 else if (!isAccessible(Subobj, Decl)) 8886 DiagKind = 3; 8887 else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() && 8888 !Decl->isTrivial()) { 8889 // A member of a union must have a trivial corresponding special member. 8890 // As a weird special case, a destructor call from a union's constructor 8891 // must be accessible and non-deleted, but need not be trivial. Such a 8892 // destructor is never actually called, but is semantically checked as 8893 // if it were. 8894 DiagKind = 4; 8895 } 8896 8897 if (DiagKind == -1) 8898 return false; 8899 8900 if (Diagnose) { 8901 if (Field) { 8902 S.Diag(Field->getLocation(), 8903 diag::note_deleted_special_member_class_subobject) 8904 << getEffectiveCSM() << MD->getParent() << /*IsField*/true 8905 << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false; 8906 } else { 8907 CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>(); 8908 S.Diag(Base->getBeginLoc(), 8909 diag::note_deleted_special_member_class_subobject) 8910 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false 8911 << Base->getType() << DiagKind << IsDtorCallInCtor 8912 << /*IsObjCPtr*/false; 8913 } 8914 8915 if (DiagKind == 1) 8916 S.NoteDeletedFunction(Decl); 8917 // FIXME: Explain inaccessibility if DiagKind == 3. 8918 } 8919 8920 return true; 8921} 8922 8923/// Check whether we should delete a special member function due to having a 8924/// direct or virtual base class or non-static data member of class type M. 8925bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject( 8926 CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) { 8927 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>(); 8928 bool IsMutable = Field && Field->isMutable(); 8929 8930 // C++11 [class.ctor]p5: 8931 // -- any direct or virtual base class, or non-static data member with no 8932 // brace-or-equal-initializer, has class type M (or array thereof) and 8933 // either M has no default constructor or overload resolution as applied 8934 // to M's default constructor results in an ambiguity or in a function 8935 // that is deleted or inaccessible 8936 // C++11 [class.copy]p11, C++11 [class.copy]p23: 8937 // -- a direct or virtual base class B that cannot be copied/moved because 8938 // overload resolution, as applied to B's corresponding special member, 8939 // results in an ambiguity or a function that is deleted or inaccessible 8940 // from the defaulted special member 8941 // C++11 [class.dtor]p5: 8942 // -- any direct or virtual base class [...] has a type with a destructor 8943 // that is deleted or inaccessible 8944 if (!(CSM == Sema::CXXDefaultConstructor && 8945 Field && Field->hasInClassInitializer()) && 8946 shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable), 8947 false)) 8948 return true; 8949 8950 // C++11 [class.ctor]p5, C++11 [class.copy]p11: 8951 // -- any direct or virtual base class or non-static data member has a 8952 // type with a destructor that is deleted or inaccessible 8953 if (IsConstructor) { 8954 Sema::SpecialMemberOverloadResult SMOR = 8955 S.LookupSpecialMember(Class, Sema::CXXDestructor, 8956 false, false, false, false, false); 8957 if (shouldDeleteForSubobjectCall(Subobj, SMOR, true)) 8958 return true; 8959 } 8960 8961 return false; 8962} 8963 8964bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember( 8965 FieldDecl *FD, QualType FieldType) { 8966 // The defaulted special functions are defined as deleted if this is a variant 8967 // member with a non-trivial ownership type, e.g., ObjC __strong or __weak 8968 // type under ARC. 8969 if (!FieldType.hasNonTrivialObjCLifetime()) 8970 return false; 8971 8972 // Don't make the defaulted default constructor defined as deleted if the 8973 // member has an in-class initializer. 8974 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) 8975 return false; 8976 8977 if (Diagnose) { 8978 auto *ParentClass = cast<CXXRecordDecl>(FD->getParent()); 8979 S.Diag(FD->getLocation(), 8980 diag::note_deleted_special_member_class_subobject) 8981 << getEffectiveCSM() << ParentClass << /*IsField*/true 8982 << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true; 8983 } 8984 8985 return true; 8986} 8987 8988/// Check whether we should delete a special member function due to the class 8989/// having a particular direct or virtual base class. 8990bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) { 8991 CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl(); 8992 // If program is correct, BaseClass cannot be null, but if it is, the error 8993 // must be reported elsewhere. 8994 if (!BaseClass) 8995 return false; 8996 // If we have an inheriting constructor, check whether we're calling an 8997 // inherited constructor instead of a default constructor. 8998 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass); 8999 if (auto *BaseCtor = SMOR.getMethod()) { 9000 // Note that we do not check access along this path; other than that, 9001 // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false); 9002 // FIXME: Check that the base has a usable destructor! Sink this into 9003 // shouldDeleteForClassSubobject. 9004 if (BaseCtor->isDeleted() && Diagnose) { 9005 S.Diag(Base->getBeginLoc(), 9006 diag::note_deleted_special_member_class_subobject) 9007 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false 9008 << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false 9009 << /*IsObjCPtr*/false; 9010 S.NoteDeletedFunction(BaseCtor); 9011 } 9012 return BaseCtor->isDeleted(); 9013 } 9014 return shouldDeleteForClassSubobject(BaseClass, Base, 0); 9015} 9016 9017/// Check whether we should delete a special member function due to the class 9018/// having a particular non-static data member. 9019bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) { 9020 QualType FieldType = S.Context.getBaseElementType(FD->getType()); 9021 CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl(); 9022 9023 if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType)) 9024 return true; 9025 9026 if (CSM == Sema::CXXDefaultConstructor) { 9027 // For a default constructor, all references must be initialized in-class 9028 // and, if a union, it must have a non-const member. 9029 if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) { 9030 if (Diagnose) 9031 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) 9032 << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0; 9033 return true; 9034 } 9035 // C++11 [class.ctor]p5: any non-variant non-static data member of 9036 // const-qualified type (or array thereof) with no 9037 // brace-or-equal-initializer does not have a user-provided default 9038 // constructor. 9039 if (!inUnion() && FieldType.isConstQualified() && 9040 !FD->hasInClassInitializer() && 9041 (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) { 9042 if (Diagnose) 9043 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field) 9044 << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1; 9045 return true; 9046 } 9047 9048 if (inUnion() && !FieldType.isConstQualified()) 9049 AllFieldsAreConst = false; 9050 } else if (CSM == Sema::CXXCopyConstructor) { 9051 // For a copy constructor, data members must not be of rvalue reference 9052 // type. 9053 if (FieldType->isRValueReferenceType()) { 9054 if (Diagnose) 9055 S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference) 9056 << MD->getParent() << FD << FieldType; 9057 return true; 9058 } 9059 } else if (IsAssignment) { 9060 // For an assignment operator, data members must not be of reference type. 9061 if (FieldType->isReferenceType()) { 9062 if (Diagnose) 9063 S.Diag(FD->getLocation(), diag::note_deleted_assign_field) 9064 << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0; 9065 return true; 9066 } 9067 if (!FieldRecord && FieldType.isConstQualified()) { 9068 // C++11 [class.copy]p23: 9069 // -- a non-static data member of const non-class type (or array thereof) 9070 if (Diagnose) 9071 S.Diag(FD->getLocation(), diag::note_deleted_assign_field) 9072 << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1; 9073 return true; 9074 } 9075 } 9076 9077 if (FieldRecord) { 9078 // Some additional restrictions exist on the variant members. 9079 if (!inUnion() && FieldRecord->isUnion() && 9080 FieldRecord->isAnonymousStructOrUnion()) { 9081 bool AllVariantFieldsAreConst = true; 9082 9083 // FIXME: Handle anonymous unions declared within anonymous unions. 9084 for (auto *UI : FieldRecord->fields()) { 9085 QualType UnionFieldType = S.Context.getBaseElementType(UI->getType()); 9086 9087 if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType)) 9088 return true; 9089 9090 if (!UnionFieldType.isConstQualified()) 9091 AllVariantFieldsAreConst = false; 9092 9093 CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl(); 9094 if (UnionFieldRecord && 9095 shouldDeleteForClassSubobject(UnionFieldRecord, UI, 9096 UnionFieldType.getCVRQualifiers())) 9097 return true; 9098 } 9099 9100 // At least one member in each anonymous union must be non-const 9101 if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst && 9102 !FieldRecord->field_empty()) { 9103 if (Diagnose) 9104 S.Diag(FieldRecord->getLocation(), 9105 diag::note_deleted_default_ctor_all_const) 9106 << !!ICI << MD->getParent() << /*anonymous union*/1; 9107 return true; 9108 } 9109 9110 // Don't check the implicit member of the anonymous union type. 9111 // This is technically non-conformant, but sanity demands it. 9112 return false; 9113 } 9114 9115 if (shouldDeleteForClassSubobject(FieldRecord, FD, 9116 FieldType.getCVRQualifiers())) 9117 return true; 9118 } 9119 9120 return false; 9121} 9122 9123/// C++11 [class.ctor] p5: 9124/// A defaulted default constructor for a class X is defined as deleted if 9125/// X is a union and all of its variant members are of const-qualified type. 9126bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() { 9127 // This is a silly definition, because it gives an empty union a deleted 9128 // default constructor. Don't do that. 9129 if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) { 9130 bool AnyFields = false; 9131 for (auto *F : MD->getParent()->fields()) 9132 if ((AnyFields = !F->isUnnamedBitfield())) 9133 break; 9134 if (!AnyFields) 9135 return false; 9136 if (Diagnose) 9137 S.Diag(MD->getParent()->getLocation(), 9138 diag::note_deleted_default_ctor_all_const) 9139 << !!ICI << MD->getParent() << /*not anonymous union*/0; 9140 return true; 9141 } 9142 return false; 9143} 9144 9145/// Determine whether a defaulted special member function should be defined as 9146/// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11, 9147/// C++11 [class.copy]p23, and C++11 [class.dtor]p5. 9148bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM, 9149 InheritedConstructorInfo *ICI, 9150 bool Diagnose) { 9151 if (MD->isInvalidDecl()) 9152 return false; 9153 CXXRecordDecl *RD = MD->getParent(); 9154 assert(!RD->isDependentType() && "do deletion after instantiation")((void)0); 9155 if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl()) 9156 return false; 9157 9158 // C++11 [expr.lambda.prim]p19: 9159 // The closure type associated with a lambda-expression has a 9160 // deleted (8.4.3) default constructor and a deleted copy 9161 // assignment operator. 9162 // C++2a adds back these operators if the lambda has no lambda-capture. 9163 if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() && 9164 (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) { 9165 if (Diagnose) 9166 Diag(RD->getLocation(), diag::note_lambda_decl); 9167 return true; 9168 } 9169 9170 // For an anonymous struct or union, the copy and assignment special members 9171 // will never be used, so skip the check. For an anonymous union declared at 9172 // namespace scope, the constructor and destructor are used. 9173 if (CSM != CXXDefaultConstructor && CSM != CXXDestructor && 9174 RD->isAnonymousStructOrUnion()) 9175 return false; 9176 9177 // C++11 [class.copy]p7, p18: 9178 // If the class definition declares a move constructor or move assignment 9179 // operator, an implicitly declared copy constructor or copy assignment 9180 // operator is defined as deleted. 9181 if (MD->isImplicit() && 9182 (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) { 9183 CXXMethodDecl *UserDeclaredMove = nullptr; 9184 9185 // In Microsoft mode up to MSVC 2013, a user-declared move only causes the 9186 // deletion of the corresponding copy operation, not both copy operations. 9187 // MSVC 2015 has adopted the standards conforming behavior. 9188 bool DeletesOnlyMatchingCopy = 9189 getLangOpts().MSVCCompat && 9190 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015); 9191 9192 if (RD->hasUserDeclaredMoveConstructor() && 9193 (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) { 9194 if (!Diagnose) return true; 9195 9196 // Find any user-declared move constructor. 9197 for (auto *I : RD->ctors()) { 9198 if (I->isMoveConstructor()) { 9199 UserDeclaredMove = I; 9200 break; 9201 } 9202 } 9203 assert(UserDeclaredMove)((void)0); 9204 } else if (RD->hasUserDeclaredMoveAssignment() && 9205 (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) { 9206 if (!Diagnose) return true; 9207 9208 // Find any user-declared move assignment operator. 9209 for (auto *I : RD->methods()) { 9210 if (I->isMoveAssignmentOperator()) { 9211 UserDeclaredMove = I; 9212 break; 9213 } 9214 } 9215 assert(UserDeclaredMove)((void)0); 9216 } 9217 9218 if (UserDeclaredMove) { 9219 Diag(UserDeclaredMove->getLocation(), 9220 diag::note_deleted_copy_user_declared_move) 9221 << (CSM == CXXCopyAssignment) << RD 9222 << UserDeclaredMove->isMoveAssignmentOperator(); 9223 return true; 9224 } 9225 } 9226 9227 // Do access control from the special member function 9228 ContextRAII MethodContext(*this, MD); 9229 9230 // C++11 [class.dtor]p5: 9231 // -- for a virtual destructor, lookup of the non-array deallocation function 9232 // results in an ambiguity or in a function that is deleted or inaccessible 9233 if (CSM == CXXDestructor && MD->isVirtual()) { 9234 FunctionDecl *OperatorDelete = nullptr; 9235 DeclarationName Name = 9236 Context.DeclarationNames.getCXXOperatorName(OO_Delete); 9237 if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name, 9238 OperatorDelete, /*Diagnose*/false)) { 9239 if (Diagnose) 9240 Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete); 9241 return true; 9242 } 9243 } 9244 9245 SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose); 9246 9247 // Per DR1611, do not consider virtual bases of constructors of abstract 9248 // classes, since we are not going to construct them. 9249 // Per DR1658, do not consider virtual bases of destructors of abstract 9250 // classes either. 9251 // Per DR2180, for assignment operators we only assign (and thus only 9252 // consider) direct bases. 9253 if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases 9254 : SMI.VisitPotentiallyConstructedBases)) 9255 return true; 9256 9257 if (SMI.shouldDeleteForAllConstMembers()) 9258 return true; 9259 9260 if (getLangOpts().CUDA) { 9261 // We should delete the special member in CUDA mode if target inference 9262 // failed. 9263 // For inherited constructors (non-null ICI), CSM may be passed so that MD 9264 // is treated as certain special member, which may not reflect what special 9265 // member MD really is. However inferCUDATargetForImplicitSpecialMember 9266 // expects CSM to match MD, therefore recalculate CSM. 9267 assert(ICI || CSM == getSpecialMember(MD))((void)0); 9268 auto RealCSM = CSM; 9269 if (ICI) 9270 RealCSM = getSpecialMember(MD); 9271 9272 return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD, 9273 SMI.ConstArg, Diagnose); 9274 } 9275 9276 return false; 9277} 9278 9279void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) { 9280 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD); 9281 assert(DFK && "not a defaultable function")((void)0); 9282 assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted")((void)0); 9283 9284 if (DFK.isSpecialMember()) { 9285 ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), 9286 nullptr, /*Diagnose=*/true); 9287 } else { 9288 DefaultedComparisonAnalyzer( 9289 *this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD, 9290 DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted) 9291 .visit(); 9292 } 9293} 9294 9295/// Perform lookup for a special member of the specified kind, and determine 9296/// whether it is trivial. If the triviality can be determined without the 9297/// lookup, skip it. This is intended for use when determining whether a 9298/// special member of a containing object is trivial, and thus does not ever 9299/// perform overload resolution for default constructors. 9300/// 9301/// If \p Selected is not \c NULL, \c *Selected will be filled in with the 9302/// member that was most likely to be intended to be trivial, if any. 9303/// 9304/// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to 9305/// determine whether the special member is trivial. 9306static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD, 9307 Sema::CXXSpecialMember CSM, unsigned Quals, 9308 bool ConstRHS, 9309 Sema::TrivialABIHandling TAH, 9310 CXXMethodDecl **Selected) { 9311 if (Selected) 9312 *Selected = nullptr; 9313 9314 switch (CSM) { 9315 case Sema::CXXInvalid: 9316 llvm_unreachable("not a special member")__builtin_unreachable(); 9317 9318 case Sema::CXXDefaultConstructor: 9319 // C++11 [class.ctor]p5: 9320 // A default constructor is trivial if: 9321 // - all the [direct subobjects] have trivial default constructors 9322 // 9323 // Note, no overload resolution is performed in this case. 9324 if (RD->hasTrivialDefaultConstructor()) 9325 return true; 9326 9327 if (Selected) { 9328 // If there's a default constructor which could have been trivial, dig it 9329 // out. Otherwise, if there's any user-provided default constructor, point 9330 // to that as an example of why there's not a trivial one. 9331 CXXConstructorDecl *DefCtor = nullptr; 9332 if (RD->needsImplicitDefaultConstructor()) 9333 S.DeclareImplicitDefaultConstructor(RD); 9334 for (auto *CI : RD->ctors()) { 9335 if (!CI->isDefaultConstructor()) 9336 continue; 9337 DefCtor = CI; 9338 if (!DefCtor->isUserProvided()) 9339 break; 9340 } 9341 9342 *Selected = DefCtor; 9343 } 9344 9345 return false; 9346 9347 case Sema::CXXDestructor: 9348 // C++11 [class.dtor]p5: 9349 // A destructor is trivial if: 9350 // - all the direct [subobjects] have trivial destructors 9351 if (RD->hasTrivialDestructor() || 9352 (TAH == Sema::TAH_ConsiderTrivialABI && 9353 RD->hasTrivialDestructorForCall())) 9354 return true; 9355 9356 if (Selected) { 9357 if (RD->needsImplicitDestructor()) 9358 S.DeclareImplicitDestructor(RD); 9359 *Selected = RD->getDestructor(); 9360 } 9361 9362 return false; 9363 9364 case Sema::CXXCopyConstructor: 9365 // C++11 [class.copy]p12: 9366 // A copy constructor is trivial if: 9367 // - the constructor selected to copy each direct [subobject] is trivial 9368 if (RD->hasTrivialCopyConstructor() || 9369 (TAH == Sema::TAH_ConsiderTrivialABI && 9370 RD->hasTrivialCopyConstructorForCall())) { 9371 if (Quals == Qualifiers::Const) 9372 // We must either select the trivial copy constructor or reach an 9373 // ambiguity; no need to actually perform overload resolution. 9374 return true; 9375 } else if (!Selected) { 9376 return false; 9377 } 9378 // In C++98, we are not supposed to perform overload resolution here, but we 9379 // treat that as a language defect, as suggested on cxx-abi-dev, to treat 9380 // cases like B as having a non-trivial copy constructor: 9381 // struct A { template<typename T> A(T&); }; 9382 // struct B { mutable A a; }; 9383 goto NeedOverloadResolution; 9384 9385 case Sema::CXXCopyAssignment: 9386 // C++11 [class.copy]p25: 9387 // A copy assignment operator is trivial if: 9388 // - the assignment operator selected to copy each direct [subobject] is 9389 // trivial 9390 if (RD->hasTrivialCopyAssignment()) { 9391 if (Quals == Qualifiers::Const) 9392 return true; 9393 } else if (!Selected) { 9394 return false; 9395 } 9396 // In C++98, we are not supposed to perform overload resolution here, but we 9397 // treat that as a language defect. 9398 goto NeedOverloadResolution; 9399 9400 case Sema::CXXMoveConstructor: 9401 case Sema::CXXMoveAssignment: 9402 NeedOverloadResolution: 9403 Sema::SpecialMemberOverloadResult SMOR = 9404 lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS); 9405 9406 // The standard doesn't describe how to behave if the lookup is ambiguous. 9407 // We treat it as not making the member non-trivial, just like the standard 9408 // mandates for the default constructor. This should rarely matter, because 9409 // the member will also be deleted. 9410 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous) 9411 return true; 9412 9413 if (!SMOR.getMethod()) { 9414 assert(SMOR.getKind() ==((void)0) 9415 Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)((void)0); 9416 return false; 9417 } 9418 9419 // We deliberately don't check if we found a deleted special member. We're 9420 // not supposed to! 9421 if (Selected) 9422 *Selected = SMOR.getMethod(); 9423 9424 if (TAH == Sema::TAH_ConsiderTrivialABI && 9425 (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor)) 9426 return SMOR.getMethod()->isTrivialForCall(); 9427 return SMOR.getMethod()->isTrivial(); 9428 } 9429 9430 llvm_unreachable("unknown special method kind")__builtin_unreachable(); 9431} 9432 9433static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) { 9434 for (auto *CI : RD->ctors()) 9435 if (!CI->isImplicit()) 9436 return CI; 9437 9438 // Look for constructor templates. 9439 typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter; 9440 for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) { 9441 if (CXXConstructorDecl *CD = 9442 dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl())) 9443 return CD; 9444 } 9445 9446 return nullptr; 9447} 9448 9449/// The kind of subobject we are checking for triviality. The values of this 9450/// enumeration are used in diagnostics. 9451enum TrivialSubobjectKind { 9452 /// The subobject is a base class. 9453 TSK_BaseClass, 9454 /// The subobject is a non-static data member. 9455 TSK_Field, 9456 /// The object is actually the complete object. 9457 TSK_CompleteObject 9458}; 9459 9460/// Check whether the special member selected for a given type would be trivial. 9461static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc, 9462 QualType SubType, bool ConstRHS, 9463 Sema::CXXSpecialMember CSM, 9464 TrivialSubobjectKind Kind, 9465 Sema::TrivialABIHandling TAH, bool Diagnose) { 9466 CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl(); 9467 if (!SubRD) 9468 return true; 9469 9470 CXXMethodDecl *Selected; 9471 if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(), 9472 ConstRHS, TAH, Diagnose ? &Selected : nullptr)) 9473 return true; 9474 9475 if (Diagnose) { 9476 if (ConstRHS) 9477 SubType.addConst(); 9478 9479 if (!Selected && CSM == Sema::CXXDefaultConstructor) { 9480 S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor) 9481 << Kind << SubType.getUnqualifiedType(); 9482 if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD)) 9483 S.Diag(CD->getLocation(), diag::note_user_declared_ctor); 9484 } else if (!Selected) 9485 S.Diag(SubobjLoc, diag::note_nontrivial_no_copy) 9486 << Kind << SubType.getUnqualifiedType() << CSM << SubType; 9487 else if (Selected->isUserProvided()) { 9488 if (Kind == TSK_CompleteObject) 9489 S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided) 9490 << Kind << SubType.getUnqualifiedType() << CSM; 9491 else { 9492 S.Diag(SubobjLoc, diag::note_nontrivial_user_provided) 9493 << Kind << SubType.getUnqualifiedType() << CSM; 9494 S.Diag(Selected->getLocation(), diag::note_declared_at); 9495 } 9496 } else { 9497 if (Kind != TSK_CompleteObject) 9498 S.Diag(SubobjLoc, diag::note_nontrivial_subobject) 9499 << Kind << SubType.getUnqualifiedType() << CSM; 9500 9501 // Explain why the defaulted or deleted special member isn't trivial. 9502 S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI, 9503 Diagnose); 9504 } 9505 } 9506 9507 return false; 9508} 9509 9510/// Check whether the members of a class type allow a special member to be 9511/// trivial. 9512static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD, 9513 Sema::CXXSpecialMember CSM, 9514 bool ConstArg, 9515 Sema::TrivialABIHandling TAH, 9516 bool Diagnose) { 9517 for (const auto *FI : RD->fields()) { 9518 if (FI->isInvalidDecl() || FI->isUnnamedBitfield()) 9519 continue; 9520 9521 QualType FieldType = S.Context.getBaseElementType(FI->getType()); 9522 9523 // Pretend anonymous struct or union members are members of this class. 9524 if (FI->isAnonymousStructOrUnion()) { 9525 if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(), 9526 CSM, ConstArg, TAH, Diagnose)) 9527 return false; 9528 continue; 9529 } 9530 9531 // C++11 [class.ctor]p5: 9532 // A default constructor is trivial if [...] 9533 // -- no non-static data member of its class has a 9534 // brace-or-equal-initializer 9535 if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) { 9536 if (Diagnose) 9537 S.Diag(FI->getLocation(), diag::note_nontrivial_default_member_init) 9538 << FI; 9539 return false; 9540 } 9541 9542 // Objective C ARC 4.3.5: 9543 // [...] nontrivally ownership-qualified types are [...] not trivially 9544 // default constructible, copy constructible, move constructible, copy 9545 // assignable, move assignable, or destructible [...] 9546 if (FieldType.hasNonTrivialObjCLifetime()) { 9547 if (Diagnose) 9548 S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership) 9549 << RD << FieldType.getObjCLifetime(); 9550 return false; 9551 } 9552 9553 bool ConstRHS = ConstArg && !FI->isMutable(); 9554 if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS, 9555 CSM, TSK_Field, TAH, Diagnose)) 9556 return false; 9557 } 9558 9559 return true; 9560} 9561 9562/// Diagnose why the specified class does not have a trivial special member of 9563/// the given kind. 9564void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) { 9565 QualType Ty = Context.getRecordType(RD); 9566 9567 bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment); 9568 checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM, 9569 TSK_CompleteObject, TAH_IgnoreTrivialABI, 9570 /*Diagnose*/true); 9571} 9572 9573/// Determine whether a defaulted or deleted special member function is trivial, 9574/// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12, 9575/// C++11 [class.copy]p25, and C++11 [class.dtor]p5. 9576bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM, 9577 TrivialABIHandling TAH, bool Diagnose) { 9578 assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough")((void)0); 9579 9580 CXXRecordDecl *RD = MD->getParent(); 9581 9582 bool ConstArg = false; 9583 9584 // C++11 [class.copy]p12, p25: [DR1593] 9585 // A [special member] is trivial if [...] its parameter-type-list is 9586 // equivalent to the parameter-type-list of an implicit declaration [...] 9587 switch (CSM) { 9588 case CXXDefaultConstructor: 9589 case CXXDestructor: 9590 // Trivial default constructors and destructors cannot have parameters. 9591 break; 9592 9593 case CXXCopyConstructor: 9594 case CXXCopyAssignment: { 9595 // Trivial copy operations always have const, non-volatile parameter types. 9596 ConstArg = true; 9597 const ParmVarDecl *Param0 = MD->getParamDecl(0); 9598 const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>(); 9599 if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) { 9600 if (Diagnose) 9601 Diag(Param0->getLocation(), diag::note_nontrivial_param_type) 9602 << Param0->getSourceRange() << Param0->getType() 9603 << Context.getLValueReferenceType( 9604 Context.getRecordType(RD).withConst()); 9605 return false; 9606 } 9607 break; 9608 } 9609 9610 case CXXMoveConstructor: 9611 case CXXMoveAssignment: { 9612 // Trivial move operations always have non-cv-qualified parameters. 9613 const ParmVarDecl *Param0 = MD->getParamDecl(0); 9614 const RValueReferenceType *RT = 9615 Param0->getType()->getAs<RValueReferenceType>(); 9616 if (!RT || RT->getPointeeType().getCVRQualifiers()) { 9617 if (Diagnose) 9618 Diag(Param0->getLocation(), diag::note_nontrivial_param_type) 9619 << Param0->getSourceRange() << Param0->getType() 9620 << Context.getRValueReferenceType(Context.getRecordType(RD)); 9621 return false; 9622 } 9623 break; 9624 } 9625 9626 case CXXInvalid: 9627 llvm_unreachable("not a special member")__builtin_unreachable(); 9628 } 9629 9630 if (MD->getMinRequiredArguments() < MD->getNumParams()) { 9631 if (Diagnose) 9632 Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(), 9633 diag::note_nontrivial_default_arg) 9634 << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange(); 9635 return false; 9636 } 9637 if (MD->isVariadic()) { 9638 if (Diagnose) 9639 Diag(MD->getLocation(), diag::note_nontrivial_variadic); 9640 return false; 9641 } 9642 9643 // C++11 [class.ctor]p5, C++11 [class.dtor]p5: 9644 // A copy/move [constructor or assignment operator] is trivial if 9645 // -- the [member] selected to copy/move each direct base class subobject 9646 // is trivial 9647 // 9648 // C++11 [class.copy]p12, C++11 [class.copy]p25: 9649 // A [default constructor or destructor] is trivial if 9650 // -- all the direct base classes have trivial [default constructors or 9651 // destructors] 9652 for (const auto &BI : RD->bases()) 9653 if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(), 9654 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose)) 9655 return false; 9656 9657 // C++11 [class.ctor]p5, C++11 [class.dtor]p5: 9658 // A copy/move [constructor or assignment operator] for a class X is 9659 // trivial if 9660 // -- for each non-static data member of X that is of class type (or array 9661 // thereof), the constructor selected to copy/move that member is 9662 // trivial 9663 // 9664 // C++11 [class.copy]p12, C++11 [class.copy]p25: 9665 // A [default constructor or destructor] is trivial if 9666 // -- for all of the non-static data members of its class that are of class 9667 // type (or array thereof), each such class has a trivial [default 9668 // constructor or destructor] 9669 if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose)) 9670 return false; 9671 9672 // C++11 [class.dtor]p5: 9673 // A destructor is trivial if [...] 9674 // -- the destructor is not virtual 9675 if (CSM == CXXDestructor && MD->isVirtual()) { 9676 if (Diagnose) 9677 Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD; 9678 return false; 9679 } 9680 9681 // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25: 9682 // A [special member] for class X is trivial if [...] 9683 // -- class X has no virtual functions and no virtual base classes 9684 if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) { 9685 if (!Diagnose) 9686 return false; 9687 9688 if (RD->getNumVBases()) { 9689 // Check for virtual bases. We already know that the corresponding 9690 // member in all bases is trivial, so vbases must all be direct. 9691 CXXBaseSpecifier &BS = *RD->vbases_begin(); 9692 assert(BS.isVirtual())((void)0); 9693 Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1; 9694 return false; 9695 } 9696 9697 // Must have a virtual method. 9698 for (const auto *MI : RD->methods()) { 9699 if (MI->isVirtual()) { 9700 SourceLocation MLoc = MI->getBeginLoc(); 9701 Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0; 9702 return false; 9703 } 9704 } 9705 9706 llvm_unreachable("dynamic class with no vbases and no virtual functions")__builtin_unreachable(); 9707 } 9708 9709 // Looks like it's trivial! 9710 return true; 9711} 9712 9713namespace { 9714struct FindHiddenVirtualMethod { 9715 Sema *S; 9716 CXXMethodDecl *Method; 9717 llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods; 9718 SmallVector<CXXMethodDecl *, 8> OverloadedMethods; 9719 9720private: 9721 /// Check whether any most overridden method from MD in Methods 9722 static bool CheckMostOverridenMethods( 9723 const CXXMethodDecl *MD, 9724 const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) { 9725 if (MD->size_overridden_methods() == 0) 9726 return Methods.count(MD->getCanonicalDecl()); 9727 for (const CXXMethodDecl *O : MD->overridden_methods()) 9728 if (CheckMostOverridenMethods(O, Methods)) 9729 return true; 9730 return false; 9731 } 9732 9733public: 9734 /// Member lookup function that determines whether a given C++ 9735 /// method overloads virtual methods in a base class without overriding any, 9736 /// to be used with CXXRecordDecl::lookupInBases(). 9737 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) { 9738 RecordDecl *BaseRecord = 9739 Specifier->getType()->castAs<RecordType>()->getDecl(); 9740 9741 DeclarationName Name = Method->getDeclName(); 9742 assert(Name.getNameKind() == DeclarationName::Identifier)((void)0); 9743 9744 bool foundSameNameMethod = false; 9745 SmallVector<CXXMethodDecl *, 8> overloadedMethods; 9746 for (Path.Decls = BaseRecord->lookup(Name).begin(); 9747 Path.Decls != DeclContext::lookup_iterator(); ++Path.Decls) { 9748 NamedDecl *D = *Path.Decls; 9749 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) { 9750 MD = MD->getCanonicalDecl(); 9751 foundSameNameMethod = true; 9752 // Interested only in hidden virtual methods. 9753 if (!MD->isVirtual()) 9754 continue; 9755 // If the method we are checking overrides a method from its base 9756 // don't warn about the other overloaded methods. Clang deviates from 9757 // GCC by only diagnosing overloads of inherited virtual functions that 9758 // do not override any other virtual functions in the base. GCC's 9759 // -Woverloaded-virtual diagnoses any derived function hiding a virtual 9760 // function from a base class. These cases may be better served by a 9761 // warning (not specific to virtual functions) on call sites when the 9762 // call would select a different function from the base class, were it 9763 // visible. 9764 // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example. 9765 if (!S->IsOverload(Method, MD, false)) 9766 return true; 9767 // Collect the overload only if its hidden. 9768 if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods)) 9769 overloadedMethods.push_back(MD); 9770 } 9771 } 9772 9773 if (foundSameNameMethod) 9774 OverloadedMethods.append(overloadedMethods.begin(), 9775 overloadedMethods.end()); 9776 return foundSameNameMethod; 9777 } 9778}; 9779} // end anonymous namespace 9780 9781/// Add the most overriden methods from MD to Methods 9782static void AddMostOverridenMethods(const CXXMethodDecl *MD, 9783 llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) { 9784 if (MD->size_overridden_methods() == 0) 9785 Methods.insert(MD->getCanonicalDecl()); 9786 else 9787 for (const CXXMethodDecl *O : MD->overridden_methods()) 9788 AddMostOverridenMethods(O, Methods); 9789} 9790 9791/// Check if a method overloads virtual methods in a base class without 9792/// overriding any. 9793void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD, 9794 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) { 9795 if (!MD->getDeclName().isIdentifier()) 9796 return; 9797 9798 CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases. 9799 /*bool RecordPaths=*/false, 9800 /*bool DetectVirtual=*/false); 9801 FindHiddenVirtualMethod FHVM; 9802 FHVM.Method = MD; 9803 FHVM.S = this; 9804 9805 // Keep the base methods that were overridden or introduced in the subclass 9806 // by 'using' in a set. A base method not in this set is hidden. 9807 CXXRecordDecl *DC = MD->getParent(); 9808 DeclContext::lookup_result R = DC->lookup(MD->getDeclName()); 9809 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) { 9810 NamedDecl *ND = *I; 9811 if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I)) 9812 ND = shad->getTargetDecl(); 9813 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND)) 9814 AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods); 9815 } 9816 9817 if (DC->lookupInBases(FHVM, Paths)) 9818 OverloadedMethods = FHVM.OverloadedMethods; 9819} 9820 9821void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD, 9822 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) { 9823 for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) { 9824 CXXMethodDecl *overloadedMD = OverloadedMethods[i]; 9825 PartialDiagnostic PD = PDiag( 9826 diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD; 9827 HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType()); 9828 Diag(overloadedMD->getLocation(), PD); 9829 } 9830} 9831 9832/// Diagnose methods which overload virtual methods in a base class 9833/// without overriding any. 9834void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) { 9835 if (MD->isInvalidDecl()) 9836 return; 9837 9838 if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation())) 9839 return; 9840 9841 SmallVector<CXXMethodDecl *, 8> OverloadedMethods; 9842 FindHiddenVirtualMethods(MD, OverloadedMethods); 9843 if (!OverloadedMethods.empty()) { 9844 Diag(MD->getLocation(), diag::warn_overloaded_virtual) 9845 << MD << (OverloadedMethods.size() > 1); 9846 9847 NoteHiddenVirtualMethods(MD, OverloadedMethods); 9848 } 9849} 9850 9851void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) { 9852 auto PrintDiagAndRemoveAttr = [&](unsigned N) { 9853 // No diagnostics if this is a template instantiation. 9854 if (!isTemplateInstantiation(RD.getTemplateSpecializationKind())) { 9855 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(), 9856 diag::ext_cannot_use_trivial_abi) << &RD; 9857 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(), 9858 diag::note_cannot_use_trivial_abi_reason) << &RD << N; 9859 } 9860 RD.dropAttr<TrivialABIAttr>(); 9861 }; 9862 9863 // Ill-formed if the copy and move constructors are deleted. 9864 auto HasNonDeletedCopyOrMoveConstructor = [&]() { 9865 // If the type is dependent, then assume it might have 9866 // implicit copy or move ctor because we won't know yet at this point. 9867 if (RD.isDependentType()) 9868 return true; 9869 if (RD.needsImplicitCopyConstructor() && 9870 !RD.defaultedCopyConstructorIsDeleted()) 9871 return true; 9872 if (RD.needsImplicitMoveConstructor() && 9873 !RD.defaultedMoveConstructorIsDeleted()) 9874 return true; 9875 for (const CXXConstructorDecl *CD : RD.ctors()) 9876 if (CD->isCopyOrMoveConstructor() && !CD->isDeleted()) 9877 return true; 9878 return false; 9879 }; 9880 9881 if (!HasNonDeletedCopyOrMoveConstructor()) { 9882 PrintDiagAndRemoveAttr(0); 9883 return; 9884 } 9885 9886 // Ill-formed if the struct has virtual functions. 9887 if (RD.isPolymorphic()) { 9888 PrintDiagAndRemoveAttr(1); 9889 return; 9890 } 9891 9892 for (const auto &B : RD.bases()) { 9893 // Ill-formed if the base class is non-trivial for the purpose of calls or a 9894 // virtual base. 9895 if (!B.getType()->isDependentType() && 9896 !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) { 9897 PrintDiagAndRemoveAttr(2); 9898 return; 9899 } 9900 9901 if (B.isVirtual()) { 9902 PrintDiagAndRemoveAttr(3); 9903 return; 9904 } 9905 } 9906 9907 for (const auto *FD : RD.fields()) { 9908 // Ill-formed if the field is an ObjectiveC pointer or of a type that is 9909 // non-trivial for the purpose of calls. 9910 QualType FT = FD->getType(); 9911 if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) { 9912 PrintDiagAndRemoveAttr(4); 9913 return; 9914 } 9915 9916 if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>()) 9917 if (!RT->isDependentType() && 9918 !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) { 9919 PrintDiagAndRemoveAttr(5); 9920 return; 9921 } 9922 } 9923} 9924 9925void Sema::ActOnFinishCXXMemberSpecification( 9926 Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac, 9927 SourceLocation RBrac, const ParsedAttributesView &AttrList) { 9928 if (!TagDecl) 9929 return; 9930 9931 AdjustDeclIfTemplate(TagDecl); 9932 9933 for (const ParsedAttr &AL : AttrList) { 9934 if (AL.getKind() != ParsedAttr::AT_Visibility) 9935 continue; 9936 AL.setInvalid(); 9937 Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL; 9938 } 9939 9940 ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef( 9941 // strict aliasing violation! 9942 reinterpret_cast<Decl**>(FieldCollector->getCurFields()), 9943 FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList); 9944 9945 CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl)); 9946} 9947 9948/// Find the equality comparison functions that should be implicitly declared 9949/// in a given class definition, per C++2a [class.compare.default]p3. 9950static void findImplicitlyDeclaredEqualityComparisons( 9951 ASTContext &Ctx, CXXRecordDecl *RD, 9952 llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) { 9953 DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual); 9954 if (!RD->lookup(EqEq).empty()) 9955 // Member operator== explicitly declared: no implicit operator==s. 9956 return; 9957 9958 // Traverse friends looking for an '==' or a '<=>'. 9959 for (FriendDecl *Friend : RD->friends()) { 9960 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl()); 9961 if (!FD) continue; 9962 9963 if (FD->getOverloadedOperator() == OO_EqualEqual) { 9964 // Friend operator== explicitly declared: no implicit operator==s. 9965 Spaceships.clear(); 9966 return; 9967 } 9968 9969 if (FD->getOverloadedOperator() == OO_Spaceship && 9970 FD->isExplicitlyDefaulted()) 9971 Spaceships.push_back(FD); 9972 } 9973 9974 // Look for members named 'operator<=>'. 9975 DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship); 9976 for (NamedDecl *ND : RD->lookup(Cmp)) { 9977 // Note that we could find a non-function here (either a function template 9978 // or a using-declaration). Neither case results in an implicit 9979 // 'operator=='. 9980 if (auto *FD = dyn_cast<FunctionDecl>(ND)) 9981 if (FD->isExplicitlyDefaulted()) 9982 Spaceships.push_back(FD); 9983 } 9984} 9985 9986/// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared 9987/// special functions, such as the default constructor, copy 9988/// constructor, or destructor, to the given C++ class (C++ 9989/// [special]p1). This routine can only be executed just before the 9990/// definition of the class is complete. 9991void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) { 9992 // Don't add implicit special members to templated classes. 9993 // FIXME: This means unqualified lookups for 'operator=' within a class 9994 // template don't work properly. 9995 if (!ClassDecl->isDependentType()) { 9996 if (ClassDecl->needsImplicitDefaultConstructor()) { 9997 ++getASTContext().NumImplicitDefaultConstructors; 9998 9999 if (ClassDecl->hasInheritedConstructor()) 10000 DeclareImplicitDefaultConstructor(ClassDecl); 10001 } 10002 10003 if (ClassDecl->needsImplicitCopyConstructor()) { 10004 ++getASTContext().NumImplicitCopyConstructors; 10005 10006 // If the properties or semantics of the copy constructor couldn't be 10007 // determined while the class was being declared, force a declaration 10008 // of it now. 10009 if (ClassDecl->needsOverloadResolutionForCopyConstructor() || 10010 ClassDecl->hasInheritedConstructor()) 10011 DeclareImplicitCopyConstructor(ClassDecl); 10012 // For the MS ABI we need to know whether the copy ctor is deleted. A 10013 // prerequisite for deleting the implicit copy ctor is that the class has 10014 // a move ctor or move assignment that is either user-declared or whose 10015 // semantics are inherited from a subobject. FIXME: We should provide a 10016 // more direct way for CodeGen to ask whether the constructor was deleted. 10017 else if (Context.getTargetInfo().getCXXABI().isMicrosoft() && 10018 (ClassDecl->hasUserDeclaredMoveConstructor() || 10019 ClassDecl->needsOverloadResolutionForMoveConstructor() || 10020 ClassDecl->hasUserDeclaredMoveAssignment() || 10021 ClassDecl->needsOverloadResolutionForMoveAssignment())) 10022 DeclareImplicitCopyConstructor(ClassDecl); 10023 } 10024 10025 if (getLangOpts().CPlusPlus11 && 10026 ClassDecl->needsImplicitMoveConstructor()) { 10027 ++getASTContext().NumImplicitMoveConstructors; 10028 10029 if (ClassDecl->needsOverloadResolutionForMoveConstructor() || 10030 ClassDecl->hasInheritedConstructor()) 10031 DeclareImplicitMoveConstructor(ClassDecl); 10032 } 10033 10034 if (ClassDecl->needsImplicitCopyAssignment()) { 10035 ++getASTContext().NumImplicitCopyAssignmentOperators; 10036 10037 // If we have a dynamic class, then the copy assignment operator may be 10038 // virtual, so we have to declare it immediately. This ensures that, e.g., 10039 // it shows up in the right place in the vtable and that we diagnose 10040 // problems with the implicit exception specification. 10041 if (ClassDecl->isDynamicClass() || 10042 ClassDecl->needsOverloadResolutionForCopyAssignment() || 10043 ClassDecl->hasInheritedAssignment()) 10044 DeclareImplicitCopyAssignment(ClassDecl); 10045 } 10046 10047 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) { 10048 ++getASTContext().NumImplicitMoveAssignmentOperators; 10049 10050 // Likewise for the move assignment operator. 10051 if (ClassDecl->isDynamicClass() || 10052 ClassDecl->needsOverloadResolutionForMoveAssignment() || 10053 ClassDecl->hasInheritedAssignment()) 10054 DeclareImplicitMoveAssignment(ClassDecl); 10055 } 10056 10057 if (ClassDecl->needsImplicitDestructor()) { 10058 ++getASTContext().NumImplicitDestructors; 10059 10060 // If we have a dynamic class, then the destructor may be virtual, so we 10061 // have to declare the destructor immediately. This ensures that, e.g., it 10062 // shows up in the right place in the vtable and that we diagnose problems 10063 // with the implicit exception specification. 10064 if (ClassDecl->isDynamicClass() || 10065 ClassDecl->needsOverloadResolutionForDestructor()) 10066 DeclareImplicitDestructor(ClassDecl); 10067 } 10068 } 10069 10070 // C++2a [class.compare.default]p3: 10071 // If the member-specification does not explicitly declare any member or 10072 // friend named operator==, an == operator function is declared implicitly 10073 // for each defaulted three-way comparison operator function defined in 10074 // the member-specification 10075 // FIXME: Consider doing this lazily. 10076 // We do this during the initial parse for a class template, not during 10077 // instantiation, so that we can handle unqualified lookups for 'operator==' 10078 // when parsing the template. 10079 if (getLangOpts().CPlusPlus20 && !inTemplateInstantiation()) { 10080 llvm::SmallVector<FunctionDecl *, 4> DefaultedSpaceships; 10081 findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl, 10082 DefaultedSpaceships); 10083 for (auto *FD : DefaultedSpaceships) 10084 DeclareImplicitEqualityComparison(ClassDecl, FD); 10085 } 10086} 10087 10088unsigned 10089Sema::ActOnReenterTemplateScope(Decl *D, 10090 llvm::function_ref<Scope *()> EnterScope) { 10091 if (!D) 10092 return 0; 10093 AdjustDeclIfTemplate(D); 10094 10095 // In order to get name lookup right, reenter template scopes in order from 10096 // outermost to innermost. 10097 SmallVector<TemplateParameterList *, 4> ParameterLists; 10098 DeclContext *LookupDC = dyn_cast<DeclContext>(D); 10099 10100 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) { 10101 for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i) 10102 ParameterLists.push_back(DD->getTemplateParameterList(i)); 10103 10104 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 10105 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) 10106 ParameterLists.push_back(FTD->getTemplateParameters()); 10107 } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) { 10108 LookupDC = VD->getDeclContext(); 10109 10110 if (VarTemplateDecl *VTD = VD->getDescribedVarTemplate()) 10111 ParameterLists.push_back(VTD->getTemplateParameters()); 10112 else if (auto *PSD = dyn_cast<VarTemplatePartialSpecializationDecl>(D)) 10113 ParameterLists.push_back(PSD->getTemplateParameters()); 10114 } 10115 } else if (TagDecl *TD = dyn_cast<TagDecl>(D)) { 10116 for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i) 10117 ParameterLists.push_back(TD->getTemplateParameterList(i)); 10118 10119 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) { 10120 if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate()) 10121 ParameterLists.push_back(CTD->getTemplateParameters()); 10122 else if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D)) 10123 ParameterLists.push_back(PSD->getTemplateParameters()); 10124 } 10125 } 10126 // FIXME: Alias declarations and concepts. 10127 10128 unsigned Count = 0; 10129 Scope *InnermostTemplateScope = nullptr; 10130 for (TemplateParameterList *Params : ParameterLists) { 10131 // Ignore explicit specializations; they don't contribute to the template 10132 // depth. 10133 if (Params->size() == 0) 10134 continue; 10135 10136 InnermostTemplateScope = EnterScope(); 10137 for (NamedDecl *Param : *Params) { 10138 if (Param->getDeclName()) { 10139 InnermostTemplateScope->AddDecl(Param); 10140 IdResolver.AddDecl(Param); 10141 } 10142 } 10143 ++Count; 10144 } 10145 10146 // Associate the new template scopes with the corresponding entities. 10147 if (InnermostTemplateScope) { 10148 assert(LookupDC && "no enclosing DeclContext for template lookup")((void)0); 10149 EnterTemplatedContext(InnermostTemplateScope, LookupDC); 10150 } 10151 10152 return Count; 10153} 10154 10155void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) { 10156 if (!RecordD) return; 10157 AdjustDeclIfTemplate(RecordD); 10158 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD); 10159 PushDeclContext(S, Record); 10160} 10161 10162void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) { 10163 if (!RecordD) return; 10164 PopDeclContext(); 10165} 10166 10167/// This is used to implement the constant expression evaluation part of the 10168/// attribute enable_if extension. There is nothing in standard C++ which would 10169/// require reentering parameters. 10170void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) { 10171 if (!Param) 10172 return; 10173 10174 S->AddDecl(Param); 10175 if (Param->getDeclName()) 10176 IdResolver.AddDecl(Param); 10177} 10178 10179/// ActOnStartDelayedCXXMethodDeclaration - We have completed 10180/// parsing a top-level (non-nested) C++ class, and we are now 10181/// parsing those parts of the given Method declaration that could 10182/// not be parsed earlier (C++ [class.mem]p2), such as default 10183/// arguments. This action should enter the scope of the given 10184/// Method declaration as if we had just parsed the qualified method 10185/// name. However, it should not bring the parameters into scope; 10186/// that will be performed by ActOnDelayedCXXMethodParameter. 10187void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { 10188} 10189 10190/// ActOnDelayedCXXMethodParameter - We've already started a delayed 10191/// C++ method declaration. We're (re-)introducing the given 10192/// function parameter into scope for use in parsing later parts of 10193/// the method declaration. For example, we could see an 10194/// ActOnParamDefaultArgument event for this parameter. 10195void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) { 10196 if (!ParamD) 10197 return; 10198 10199 ParmVarDecl *Param = cast<ParmVarDecl>(ParamD); 10200 10201 S->AddDecl(Param); 10202 if (Param->getDeclName()) 10203 IdResolver.AddDecl(Param); 10204} 10205 10206/// ActOnFinishDelayedCXXMethodDeclaration - We have finished 10207/// processing the delayed method declaration for Method. The method 10208/// declaration is now considered finished. There may be a separate 10209/// ActOnStartOfFunctionDef action later (not necessarily 10210/// immediately!) for this method, if it was also defined inside the 10211/// class body. 10212void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) { 10213 if (!MethodD) 10214 return; 10215 10216 AdjustDeclIfTemplate(MethodD); 10217 10218 FunctionDecl *Method = cast<FunctionDecl>(MethodD); 10219 10220 // Now that we have our default arguments, check the constructor 10221 // again. It could produce additional diagnostics or affect whether 10222 // the class has implicitly-declared destructors, among other 10223 // things. 10224 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method)) 10225 CheckConstructor(Constructor); 10226 10227 // Check the default arguments, which we may have added. 10228 if (!Method->isInvalidDecl()) 10229 CheckCXXDefaultArguments(Method); 10230} 10231 10232// Emit the given diagnostic for each non-address-space qualifier. 10233// Common part of CheckConstructorDeclarator and CheckDestructorDeclarator. 10234static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) { 10235 const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 10236 if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) { 10237 bool DiagOccured = false; 10238 FTI.MethodQualifiers->forEachQualifier( 10239 [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName, 10240 SourceLocation SL) { 10241 // This diagnostic should be emitted on any qualifier except an addr 10242 // space qualifier. However, forEachQualifier currently doesn't visit 10243 // addr space qualifiers, so there's no way to write this condition 10244 // right now; we just diagnose on everything. 10245 S.Diag(SL, DiagID) << QualName << SourceRange(SL); 10246 DiagOccured = true; 10247 }); 10248 if (DiagOccured) 10249 D.setInvalidType(); 10250 } 10251} 10252 10253/// CheckConstructorDeclarator - Called by ActOnDeclarator to check 10254/// the well-formedness of the constructor declarator @p D with type @p 10255/// R. If there are any errors in the declarator, this routine will 10256/// emit diagnostics and set the invalid bit to true. In any case, the type 10257/// will be updated to reflect a well-formed type for the constructor and 10258/// returned. 10259QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R, 10260 StorageClass &SC) { 10261 bool isVirtual = D.getDeclSpec().isVirtualSpecified(); 10262 10263 // C++ [class.ctor]p3: 10264 // A constructor shall not be virtual (10.3) or static (9.4). A 10265 // constructor can be invoked for a const, volatile or const 10266 // volatile object. A constructor shall not be declared const, 10267 // volatile, or const volatile (9.3.2). 10268 if (isVirtual) { 10269 if (!D.isInvalidType()) 10270 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 10271 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc()) 10272 << SourceRange(D.getIdentifierLoc()); 10273 D.setInvalidType(); 10274 } 10275 if (SC == SC_Static) { 10276 if (!D.isInvalidType()) 10277 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be) 10278 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 10279 << SourceRange(D.getIdentifierLoc()); 10280 D.setInvalidType(); 10281 SC = SC_None; 10282 } 10283 10284 if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { 10285 diagnoseIgnoredQualifiers( 10286 diag::err_constructor_return_type, TypeQuals, SourceLocation(), 10287 D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(), 10288 D.getDeclSpec().getRestrictSpecLoc(), 10289 D.getDeclSpec().getAtomicSpecLoc()); 10290 D.setInvalidType(); 10291 } 10292 10293 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor); 10294 10295 // C++0x [class.ctor]p4: 10296 // A constructor shall not be declared with a ref-qualifier. 10297 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 10298 if (FTI.hasRefQualifier()) { 10299 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor) 10300 << FTI.RefQualifierIsLValueRef 10301 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); 10302 D.setInvalidType(); 10303 } 10304 10305 // Rebuild the function type "R" without any type qualifiers (in 10306 // case any of the errors above fired) and with "void" as the 10307 // return type, since constructors don't have return types. 10308 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>(); 10309 if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType()) 10310 return R; 10311 10312 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); 10313 EPI.TypeQuals = Qualifiers(); 10314 EPI.RefQualifier = RQ_None; 10315 10316 return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI); 10317} 10318 10319/// CheckConstructor - Checks a fully-formed constructor for 10320/// well-formedness, issuing any diagnostics required. Returns true if 10321/// the constructor declarator is invalid. 10322void Sema::CheckConstructor(CXXConstructorDecl *Constructor) { 10323 CXXRecordDecl *ClassDecl 10324 = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext()); 10325 if (!ClassDecl) 10326 return Constructor->setInvalidDecl(); 10327 10328 // C++ [class.copy]p3: 10329 // A declaration of a constructor for a class X is ill-formed if 10330 // its first parameter is of type (optionally cv-qualified) X and 10331 // either there are no other parameters or else all other 10332 // parameters have default arguments. 10333 if (!Constructor->isInvalidDecl() && 10334 Constructor->hasOneParamOrDefaultArgs() && 10335 Constructor->getTemplateSpecializationKind() != 10336 TSK_ImplicitInstantiation) { 10337 QualType ParamType = Constructor->getParamDecl(0)->getType(); 10338 QualType ClassTy = Context.getTagDeclType(ClassDecl); 10339 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) { 10340 SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation(); 10341 const char *ConstRef 10342 = Constructor->getParamDecl(0)->getIdentifier() ? "const &" 10343 : " const &"; 10344 Diag(ParamLoc, diag::err_constructor_byvalue_arg) 10345 << FixItHint::CreateInsertion(ParamLoc, ConstRef); 10346 10347 // FIXME: Rather that making the constructor invalid, we should endeavor 10348 // to fix the type. 10349 Constructor->setInvalidDecl(); 10350 } 10351 } 10352} 10353 10354/// CheckDestructor - Checks a fully-formed destructor definition for 10355/// well-formedness, issuing any diagnostics required. Returns true 10356/// on error. 10357bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) { 10358 CXXRecordDecl *RD = Destructor->getParent(); 10359 10360 if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) { 10361 SourceLocation Loc; 10362 10363 if (!Destructor->isImplicit()) 10364 Loc = Destructor->getLocation(); 10365 else 10366 Loc = RD->getLocation(); 10367 10368 // If we have a virtual destructor, look up the deallocation function 10369 if (FunctionDecl *OperatorDelete = 10370 FindDeallocationFunctionForDestructor(Loc, RD)) { 10371 Expr *ThisArg = nullptr; 10372 10373 // If the notional 'delete this' expression requires a non-trivial 10374 // conversion from 'this' to the type of a destroying operator delete's 10375 // first parameter, perform that conversion now. 10376 if (OperatorDelete->isDestroyingOperatorDelete()) { 10377 QualType ParamType = OperatorDelete->getParamDecl(0)->getType(); 10378 if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) { 10379 // C++ [class.dtor]p13: 10380 // ... as if for the expression 'delete this' appearing in a 10381 // non-virtual destructor of the destructor's class. 10382 ContextRAII SwitchContext(*this, Destructor); 10383 ExprResult This = 10384 ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation()); 10385 assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?")((void)0); 10386 This = PerformImplicitConversion(This.get(), ParamType, AA_Passing); 10387 if (This.isInvalid()) { 10388 // FIXME: Register this as a context note so that it comes out 10389 // in the right order. 10390 Diag(Loc, diag::note_implicit_delete_this_in_destructor_here); 10391 return true; 10392 } 10393 ThisArg = This.get(); 10394 } 10395 } 10396 10397 DiagnoseUseOfDecl(OperatorDelete, Loc); 10398 MarkFunctionReferenced(Loc, OperatorDelete); 10399 Destructor->setOperatorDelete(OperatorDelete, ThisArg); 10400 } 10401 } 10402 10403 return false; 10404} 10405 10406/// CheckDestructorDeclarator - Called by ActOnDeclarator to check 10407/// the well-formednes of the destructor declarator @p D with type @p 10408/// R. If there are any errors in the declarator, this routine will 10409/// emit diagnostics and set the declarator to invalid. Even if this happens, 10410/// will be updated to reflect a well-formed type for the destructor and 10411/// returned. 10412QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R, 10413 StorageClass& SC) { 10414 // C++ [class.dtor]p1: 10415 // [...] A typedef-name that names a class is a class-name 10416 // (7.1.3); however, a typedef-name that names a class shall not 10417 // be used as the identifier in the declarator for a destructor 10418 // declaration. 10419 QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName); 10420 if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>()) 10421 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name) 10422 << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl()); 10423 else if (const TemplateSpecializationType *TST = 10424 DeclaratorType->getAs<TemplateSpecializationType>()) 10425 if (TST->isTypeAlias()) 10426 Diag(D.getIdentifierLoc(), diag::ext_destructor_typedef_name) 10427 << DeclaratorType << 1; 10428 10429 // C++ [class.dtor]p2: 10430 // A destructor is used to destroy objects of its class type. A 10431 // destructor takes no parameters, and no return type can be 10432 // specified for it (not even void). The address of a destructor 10433 // shall not be taken. A destructor shall not be static. A 10434 // destructor can be invoked for a const, volatile or const 10435 // volatile object. A destructor shall not be declared const, 10436 // volatile or const volatile (9.3.2). 10437 if (SC == SC_Static) { 10438 if (!D.isInvalidType()) 10439 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be) 10440 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 10441 << SourceRange(D.getIdentifierLoc()) 10442 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc()); 10443 10444 SC = SC_None; 10445 } 10446 if (!D.isInvalidType()) { 10447 // Destructors don't have return types, but the parser will 10448 // happily parse something like: 10449 // 10450 // class X { 10451 // float ~X(); 10452 // }; 10453 // 10454 // The return type will be eliminated later. 10455 if (D.getDeclSpec().hasTypeSpecifier()) 10456 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type) 10457 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc()) 10458 << SourceRange(D.getIdentifierLoc()); 10459 else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) { 10460 diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals, 10461 SourceLocation(), 10462 D.getDeclSpec().getConstSpecLoc(), 10463 D.getDeclSpec().getVolatileSpecLoc(), 10464 D.getDeclSpec().getRestrictSpecLoc(), 10465 D.getDeclSpec().getAtomicSpecLoc()); 10466 D.setInvalidType(); 10467 } 10468 } 10469 10470 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor); 10471 10472 // C++0x [class.dtor]p2: 10473 // A destructor shall not be declared with a ref-qualifier. 10474 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo(); 10475 if (FTI.hasRefQualifier()) { 10476 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor) 10477 << FTI.RefQualifierIsLValueRef 10478 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc()); 10479 D.setInvalidType(); 10480 } 10481 10482 // Make sure we don't have any parameters. 10483 if (FTIHasNonVoidParameters(FTI)) { 10484 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params); 10485 10486 // Delete the parameters. 10487 FTI.freeParams(); 10488 D.setInvalidType(); 10489 } 10490 10491 // Make sure the destructor isn't variadic. 10492 if (FTI.isVariadic) { 10493 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic); 10494 D.setInvalidType(); 10495 } 10496 10497 // Rebuild the function type "R" without any type qualifiers or 10498 // parameters (in case any of the errors above fired) and with 10499 // "void" as the return type, since destructors don't have return 10500 // types. 10501 if (!D.isInvalidType()) 10502 return R; 10503 10504 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>(); 10505 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); 10506 EPI.Variadic = false; 10507 EPI.TypeQuals = Qualifiers(); 10508 EPI.RefQualifier = RQ_None; 10509 return Context.getFunctionType(Context.VoidTy, None, EPI); 10510} 10511 10512static void extendLeft(SourceRange &R, SourceRange Before) { 10513 if (Before.isInvalid()) 10514 return; 10515 R.setBegin(Before.getBegin()); 10516 if (R.getEnd().isInvalid()) 10517 R.setEnd(Before.getEnd()); 10518} 10519 10520static void extendRight(SourceRange &R, SourceRange After) { 10521 if (After.isInvalid()) 10522 return; 10523 if (R.getBegin().isInvalid()) 10524 R.setBegin(After.getBegin()); 10525 R.setEnd(After.getEnd()); 10526} 10527 10528/// CheckConversionDeclarator - Called by ActOnDeclarator to check the 10529/// well-formednes of the conversion function declarator @p D with 10530/// type @p R. If there are any errors in the declarator, this routine 10531/// will emit diagnostics and return true. Otherwise, it will return 10532/// false. Either way, the type @p R will be updated to reflect a 10533/// well-formed type for the conversion operator. 10534void Sema::CheckConversionDeclarator(Declarator &D, QualType &R, 10535 StorageClass& SC) { 10536 // C++ [class.conv.fct]p1: 10537 // Neither parameter types nor return type can be specified. The 10538 // type of a conversion function (8.3.5) is "function taking no 10539 // parameter returning conversion-type-id." 10540 if (SC == SC_Static) { 10541 if (!D.isInvalidType()) 10542 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member) 10543 << SourceRange(D.getDeclSpec().getStorageClassSpecLoc()) 10544 << D.getName().getSourceRange(); 10545 D.setInvalidType(); 10546 SC = SC_None; 10547 } 10548 10549 TypeSourceInfo *ConvTSI = nullptr; 10550 QualType ConvType = 10551 GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI); 10552 10553 const DeclSpec &DS = D.getDeclSpec(); 10554 if (DS.hasTypeSpecifier() && !D.isInvalidType()) { 10555 // Conversion functions don't have return types, but the parser will 10556 // happily parse something like: 10557 // 10558 // class X { 10559 // float operator bool(); 10560 // }; 10561 // 10562 // The return type will be changed later anyway. 10563 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type) 10564 << SourceRange(DS.getTypeSpecTypeLoc()) 10565 << SourceRange(D.getIdentifierLoc()); 10566 D.setInvalidType(); 10567 } else if (DS.getTypeQualifiers() && !D.isInvalidType()) { 10568 // It's also plausible that the user writes type qualifiers in the wrong 10569 // place, such as: 10570 // struct S { const operator int(); }; 10571 // FIXME: we could provide a fixit to move the qualifiers onto the 10572 // conversion type. 10573 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl) 10574 << SourceRange(D.getIdentifierLoc()) << 0; 10575 D.setInvalidType(); 10576 } 10577 10578 const auto *Proto = R->castAs<FunctionProtoType>(); 10579 10580 // Make sure we don't have any parameters. 10581 if (Proto->getNumParams() > 0) { 10582 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params); 10583 10584 // Delete the parameters. 10585 D.getFunctionTypeInfo().freeParams(); 10586 D.setInvalidType(); 10587 } else if (Proto->isVariadic()) { 10588 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic); 10589 D.setInvalidType(); 10590 } 10591 10592 // Diagnose "&operator bool()" and other such nonsense. This 10593 // is actually a gcc extension which we don't support. 10594 if (Proto->getReturnType() != ConvType) { 10595 bool NeedsTypedef = false; 10596 SourceRange Before, After; 10597 10598 // Walk the chunks and extract information on them for our diagnostic. 10599 bool PastFunctionChunk = false; 10600 for (auto &Chunk : D.type_objects()) { 10601 switch (Chunk.Kind) { 10602 case DeclaratorChunk::Function: 10603 if (!PastFunctionChunk) { 10604 if (Chunk.Fun.HasTrailingReturnType) { 10605 TypeSourceInfo *TRT = nullptr; 10606 GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT); 10607 if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange()); 10608 } 10609 PastFunctionChunk = true; 10610 break; 10611 } 10612 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 10613 case DeclaratorChunk::Array: 10614 NeedsTypedef = true; 10615 extendRight(After, Chunk.getSourceRange()); 10616 break; 10617 10618 case DeclaratorChunk::Pointer: 10619 case DeclaratorChunk::BlockPointer: 10620 case DeclaratorChunk::Reference: 10621 case DeclaratorChunk::MemberPointer: 10622 case DeclaratorChunk::Pipe: 10623 extendLeft(Before, Chunk.getSourceRange()); 10624 break; 10625 10626 case DeclaratorChunk::Paren: 10627 extendLeft(Before, Chunk.Loc); 10628 extendRight(After, Chunk.EndLoc); 10629 break; 10630 } 10631 } 10632 10633 SourceLocation Loc = Before.isValid() ? Before.getBegin() : 10634 After.isValid() ? After.getBegin() : 10635 D.getIdentifierLoc(); 10636 auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl); 10637 DB << Before << After; 10638 10639 if (!NeedsTypedef) { 10640 DB << /*don't need a typedef*/0; 10641 10642 // If we can provide a correct fix-it hint, do so. 10643 if (After.isInvalid() && ConvTSI) { 10644 SourceLocation InsertLoc = 10645 getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc()); 10646 DB << FixItHint::CreateInsertion(InsertLoc, " ") 10647 << FixItHint::CreateInsertionFromRange( 10648 InsertLoc, CharSourceRange::getTokenRange(Before)) 10649 << FixItHint::CreateRemoval(Before); 10650 } 10651 } else if (!Proto->getReturnType()->isDependentType()) { 10652 DB << /*typedef*/1 << Proto->getReturnType(); 10653 } else if (getLangOpts().CPlusPlus11) { 10654 DB << /*alias template*/2 << Proto->getReturnType(); 10655 } else { 10656 DB << /*might not be fixable*/3; 10657 } 10658 10659 // Recover by incorporating the other type chunks into the result type. 10660 // Note, this does *not* change the name of the function. This is compatible 10661 // with the GCC extension: 10662 // struct S { &operator int(); } s; 10663 // int &r = s.operator int(); // ok in GCC 10664 // S::operator int&() {} // error in GCC, function name is 'operator int'. 10665 ConvType = Proto->getReturnType(); 10666 } 10667 10668 // C++ [class.conv.fct]p4: 10669 // The conversion-type-id shall not represent a function type nor 10670 // an array type. 10671 if (ConvType->isArrayType()) { 10672 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array); 10673 ConvType = Context.getPointerType(ConvType); 10674 D.setInvalidType(); 10675 } else if (ConvType->isFunctionType()) { 10676 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function); 10677 ConvType = Context.getPointerType(ConvType); 10678 D.setInvalidType(); 10679 } 10680 10681 // Rebuild the function type "R" without any parameters (in case any 10682 // of the errors above fired) and with the conversion type as the 10683 // return type. 10684 if (D.isInvalidType()) 10685 R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo()); 10686 10687 // C++0x explicit conversion operators. 10688 if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus20) 10689 Diag(DS.getExplicitSpecLoc(), 10690 getLangOpts().CPlusPlus11 10691 ? diag::warn_cxx98_compat_explicit_conversion_functions 10692 : diag::ext_explicit_conversion_functions) 10693 << SourceRange(DS.getExplicitSpecRange()); 10694} 10695 10696/// ActOnConversionDeclarator - Called by ActOnDeclarator to complete 10697/// the declaration of the given C++ conversion function. This routine 10698/// is responsible for recording the conversion function in the C++ 10699/// class, if possible. 10700Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) { 10701 assert(Conversion && "Expected to receive a conversion function declaration")((void)0); 10702 10703 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext()); 10704 10705 // Make sure we aren't redeclaring the conversion function. 10706 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType()); 10707 // C++ [class.conv.fct]p1: 10708 // [...] A conversion function is never used to convert a 10709 // (possibly cv-qualified) object to the (possibly cv-qualified) 10710 // same object type (or a reference to it), to a (possibly 10711 // cv-qualified) base class of that type (or a reference to it), 10712 // or to (possibly cv-qualified) void. 10713 QualType ClassType 10714 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); 10715 if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>()) 10716 ConvType = ConvTypeRef->getPointeeType(); 10717 if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared && 10718 Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) 10719 /* Suppress diagnostics for instantiations. */; 10720 else if (Conversion->size_overridden_methods() != 0) 10721 /* Suppress diagnostics for overriding virtual function in a base class. */; 10722 else if (ConvType->isRecordType()) { 10723 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType(); 10724 if (ConvType == ClassType) 10725 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used) 10726 << ClassType; 10727 else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType)) 10728 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used) 10729 << ClassType << ConvType; 10730 } else if (ConvType->isVoidType()) { 10731 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used) 10732 << ClassType << ConvType; 10733 } 10734 10735 if (FunctionTemplateDecl *ConversionTemplate 10736 = Conversion->getDescribedFunctionTemplate()) 10737 return ConversionTemplate; 10738 10739 return Conversion; 10740} 10741 10742namespace { 10743/// Utility class to accumulate and print a diagnostic listing the invalid 10744/// specifier(s) on a declaration. 10745struct BadSpecifierDiagnoser { 10746 BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID) 10747 : S(S), Diagnostic(S.Diag(Loc, DiagID)) {} 10748 ~BadSpecifierDiagnoser() { 10749 Diagnostic << Specifiers; 10750 } 10751 10752 template<typename T> void check(SourceLocation SpecLoc, T Spec) { 10753 return check(SpecLoc, DeclSpec::getSpecifierName(Spec)); 10754 } 10755 void check(SourceLocation SpecLoc, DeclSpec::TST Spec) { 10756 return check(SpecLoc, 10757 DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy())); 10758 } 10759 void check(SourceLocation SpecLoc, const char *Spec) { 10760 if (SpecLoc.isInvalid()) return; 10761 Diagnostic << SourceRange(SpecLoc, SpecLoc); 10762 if (!Specifiers.empty()) Specifiers += " "; 10763 Specifiers += Spec; 10764 } 10765 10766 Sema &S; 10767 Sema::SemaDiagnosticBuilder Diagnostic; 10768 std::string Specifiers; 10769}; 10770} 10771 10772/// Check the validity of a declarator that we parsed for a deduction-guide. 10773/// These aren't actually declarators in the grammar, so we need to check that 10774/// the user didn't specify any pieces that are not part of the deduction-guide 10775/// grammar. 10776void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R, 10777 StorageClass &SC) { 10778 TemplateName GuidedTemplate = D.getName().TemplateName.get().get(); 10779 TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl(); 10780 assert(GuidedTemplateDecl && "missing template decl for deduction guide")((void)0); 10781 10782 // C++ [temp.deduct.guide]p3: 10783 // A deduction-gide shall be declared in the same scope as the 10784 // corresponding class template. 10785 if (!CurContext->getRedeclContext()->Equals( 10786 GuidedTemplateDecl->getDeclContext()->getRedeclContext())) { 10787 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope) 10788 << GuidedTemplateDecl; 10789 Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here); 10790 } 10791 10792 auto &DS = D.getMutableDeclSpec(); 10793 // We leave 'friend' and 'virtual' to be rejected in the normal way. 10794 if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() || 10795 DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() || 10796 DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) { 10797 BadSpecifierDiagnoser Diagnoser( 10798 *this, D.getIdentifierLoc(), 10799 diag::err_deduction_guide_invalid_specifier); 10800 10801 Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec()); 10802 DS.ClearStorageClassSpecs(); 10803 SC = SC_None; 10804 10805 // 'explicit' is permitted. 10806 Diagnoser.check(DS.getInlineSpecLoc(), "inline"); 10807 Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn"); 10808 Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr"); 10809 DS.ClearConstexprSpec(); 10810 10811 Diagnoser.check(DS.getConstSpecLoc(), "const"); 10812 Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict"); 10813 Diagnoser.check(DS.getVolatileSpecLoc(), "volatile"); 10814 Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic"); 10815 Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned"); 10816 DS.ClearTypeQualifiers(); 10817 10818 Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex()); 10819 Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign()); 10820 Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth()); 10821 Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType()); 10822 DS.ClearTypeSpecType(); 10823 } 10824 10825 if (D.isInvalidType()) 10826 return; 10827 10828 // Check the declarator is simple enough. 10829 bool FoundFunction = false; 10830 for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) { 10831 if (Chunk.Kind == DeclaratorChunk::Paren) 10832 continue; 10833 if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) { 10834 Diag(D.getDeclSpec().getBeginLoc(), 10835 diag::err_deduction_guide_with_complex_decl) 10836 << D.getSourceRange(); 10837 break; 10838 } 10839 if (!Chunk.Fun.hasTrailingReturnType()) { 10840 Diag(D.getName().getBeginLoc(), 10841 diag::err_deduction_guide_no_trailing_return_type); 10842 break; 10843 } 10844 10845 // Check that the return type is written as a specialization of 10846 // the template specified as the deduction-guide's name. 10847 ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType(); 10848 TypeSourceInfo *TSI = nullptr; 10849 QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI); 10850 assert(TSI && "deduction guide has valid type but invalid return type?")((void)0); 10851 bool AcceptableReturnType = false; 10852 bool MightInstantiateToSpecialization = false; 10853 if (auto RetTST = 10854 TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) { 10855 TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName(); 10856 bool TemplateMatches = 10857 Context.hasSameTemplateName(SpecifiedName, GuidedTemplate); 10858 if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches) 10859 AcceptableReturnType = true; 10860 else { 10861 // This could still instantiate to the right type, unless we know it 10862 // names the wrong class template. 10863 auto *TD = SpecifiedName.getAsTemplateDecl(); 10864 MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) && 10865 !TemplateMatches); 10866 } 10867 } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) { 10868 MightInstantiateToSpecialization = true; 10869 } 10870 10871 if (!AcceptableReturnType) { 10872 Diag(TSI->getTypeLoc().getBeginLoc(), 10873 diag::err_deduction_guide_bad_trailing_return_type) 10874 << GuidedTemplate << TSI->getType() 10875 << MightInstantiateToSpecialization 10876 << TSI->getTypeLoc().getSourceRange(); 10877 } 10878 10879 // Keep going to check that we don't have any inner declarator pieces (we 10880 // could still have a function returning a pointer to a function). 10881 FoundFunction = true; 10882 } 10883 10884 if (D.isFunctionDefinition()) 10885 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function); 10886} 10887 10888//===----------------------------------------------------------------------===// 10889// Namespace Handling 10890//===----------------------------------------------------------------------===// 10891 10892/// Diagnose a mismatch in 'inline' qualifiers when a namespace is 10893/// reopened. 10894static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc, 10895 SourceLocation Loc, 10896 IdentifierInfo *II, bool *IsInline, 10897 NamespaceDecl *PrevNS) { 10898 assert(*IsInline != PrevNS->isInline())((void)0); 10899 10900 if (PrevNS->isInline()) 10901 // The user probably just forgot the 'inline', so suggest that it 10902 // be added back. 10903 S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline) 10904 << FixItHint::CreateInsertion(KeywordLoc, "inline "); 10905 else 10906 S.Diag(Loc, diag::err_inline_namespace_mismatch); 10907 10908 S.Diag(PrevNS->getLocation(), diag::note_previous_definition); 10909 *IsInline = PrevNS->isInline(); 10910} 10911 10912/// ActOnStartNamespaceDef - This is called at the start of a namespace 10913/// definition. 10914Decl *Sema::ActOnStartNamespaceDef( 10915 Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc, 10916 SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace, 10917 const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) { 10918 SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc; 10919 // For anonymous namespace, take the location of the left brace. 10920 SourceLocation Loc = II ? IdentLoc : LBrace; 10921 bool IsInline = InlineLoc.isValid(); 10922 bool IsInvalid = false; 10923 bool IsStd = false; 10924 bool AddToKnown = false; 10925 Scope *DeclRegionScope = NamespcScope->getParent(); 10926 10927 NamespaceDecl *PrevNS = nullptr; 10928 if (II) { 10929 // C++ [namespace.def]p2: 10930 // The identifier in an original-namespace-definition shall not 10931 // have been previously defined in the declarative region in 10932 // which the original-namespace-definition appears. The 10933 // identifier in an original-namespace-definition is the name of 10934 // the namespace. Subsequently in that declarative region, it is 10935 // treated as an original-namespace-name. 10936 // 10937 // Since namespace names are unique in their scope, and we don't 10938 // look through using directives, just look for any ordinary names 10939 // as if by qualified name lookup. 10940 LookupResult R(*this, II, IdentLoc, LookupOrdinaryName, 10941 ForExternalRedeclaration); 10942 LookupQualifiedName(R, CurContext->getRedeclContext()); 10943 NamedDecl *PrevDecl = 10944 R.isSingleResult() ? R.getRepresentativeDecl() : nullptr; 10945 PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl); 10946 10947 if (PrevNS) { 10948 // This is an extended namespace definition. 10949 if (IsInline != PrevNS->isInline()) 10950 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II, 10951 &IsInline, PrevNS); 10952 } else if (PrevDecl) { 10953 // This is an invalid name redefinition. 10954 Diag(Loc, diag::err_redefinition_different_kind) 10955 << II; 10956 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 10957 IsInvalid = true; 10958 // Continue on to push Namespc as current DeclContext and return it. 10959 } else if (II->isStr("std") && 10960 CurContext->getRedeclContext()->isTranslationUnit()) { 10961 // This is the first "real" definition of the namespace "std", so update 10962 // our cache of the "std" namespace to point at this definition. 10963 PrevNS = getStdNamespace(); 10964 IsStd = true; 10965 AddToKnown = !IsInline; 10966 } else { 10967 // We've seen this namespace for the first time. 10968 AddToKnown = !IsInline; 10969 } 10970 } else { 10971 // Anonymous namespaces. 10972 10973 // Determine whether the parent already has an anonymous namespace. 10974 DeclContext *Parent = CurContext->getRedeclContext(); 10975 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) { 10976 PrevNS = TU->getAnonymousNamespace(); 10977 } else { 10978 NamespaceDecl *ND = cast<NamespaceDecl>(Parent); 10979 PrevNS = ND->getAnonymousNamespace(); 10980 } 10981 10982 if (PrevNS && IsInline != PrevNS->isInline()) 10983 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II, 10984 &IsInline, PrevNS); 10985 } 10986 10987 NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline, 10988 StartLoc, Loc, II, PrevNS); 10989 if (IsInvalid) 10990 Namespc->setInvalidDecl(); 10991 10992 ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList); 10993 AddPragmaAttributes(DeclRegionScope, Namespc); 10994 10995 // FIXME: Should we be merging attributes? 10996 if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>()) 10997 PushNamespaceVisibilityAttr(Attr, Loc); 10998 10999 if (IsStd) 11000 StdNamespace = Namespc; 11001 if (AddToKnown) 11002 KnownNamespaces[Namespc] = false; 11003 11004 if (II) { 11005 PushOnScopeChains(Namespc, DeclRegionScope); 11006 } else { 11007 // Link the anonymous namespace into its parent. 11008 DeclContext *Parent = CurContext->getRedeclContext(); 11009 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) { 11010 TU->setAnonymousNamespace(Namespc); 11011 } else { 11012 cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc); 11013 } 11014 11015 CurContext->addDecl(Namespc); 11016 11017 // C++ [namespace.unnamed]p1. An unnamed-namespace-definition 11018 // behaves as if it were replaced by 11019 // namespace unique { /* empty body */ } 11020 // using namespace unique; 11021 // namespace unique { namespace-body } 11022 // where all occurrences of 'unique' in a translation unit are 11023 // replaced by the same identifier and this identifier differs 11024 // from all other identifiers in the entire program. 11025 11026 // We just create the namespace with an empty name and then add an 11027 // implicit using declaration, just like the standard suggests. 11028 // 11029 // CodeGen enforces the "universally unique" aspect by giving all 11030 // declarations semantically contained within an anonymous 11031 // namespace internal linkage. 11032 11033 if (!PrevNS) { 11034 UD = UsingDirectiveDecl::Create(Context, Parent, 11035 /* 'using' */ LBrace, 11036 /* 'namespace' */ SourceLocation(), 11037 /* qualifier */ NestedNameSpecifierLoc(), 11038 /* identifier */ SourceLocation(), 11039 Namespc, 11040 /* Ancestor */ Parent); 11041 UD->setImplicit(); 11042 Parent->addDecl(UD); 11043 } 11044 } 11045 11046 ActOnDocumentableDecl(Namespc); 11047 11048 // Although we could have an invalid decl (i.e. the namespace name is a 11049 // redefinition), push it as current DeclContext and try to continue parsing. 11050 // FIXME: We should be able to push Namespc here, so that the each DeclContext 11051 // for the namespace has the declarations that showed up in that particular 11052 // namespace definition. 11053 PushDeclContext(NamespcScope, Namespc); 11054 return Namespc; 11055} 11056 11057/// getNamespaceDecl - Returns the namespace a decl represents. If the decl 11058/// is a namespace alias, returns the namespace it points to. 11059static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) { 11060 if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D)) 11061 return AD->getNamespace(); 11062 return dyn_cast_or_null<NamespaceDecl>(D); 11063} 11064 11065/// ActOnFinishNamespaceDef - This callback is called after a namespace is 11066/// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef. 11067void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) { 11068 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl); 11069 assert(Namespc && "Invalid parameter, expected NamespaceDecl")((void)0); 11070 Namespc->setRBraceLoc(RBrace); 11071 PopDeclContext(); 11072 if (Namespc->hasAttr<VisibilityAttr>()) 11073 PopPragmaVisibility(true, RBrace); 11074 // If this namespace contains an export-declaration, export it now. 11075 if (DeferredExportedNamespaces.erase(Namespc)) 11076 Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported); 11077} 11078 11079CXXRecordDecl *Sema::getStdBadAlloc() const { 11080 return cast_or_null<CXXRecordDecl>( 11081 StdBadAlloc.get(Context.getExternalSource())); 11082} 11083 11084EnumDecl *Sema::getStdAlignValT() const { 11085 return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource())); 11086} 11087 11088NamespaceDecl *Sema::getStdNamespace() const { 11089 return cast_or_null<NamespaceDecl>( 11090 StdNamespace.get(Context.getExternalSource())); 11091} 11092 11093NamespaceDecl *Sema::lookupStdExperimentalNamespace() { 11094 if (!StdExperimentalNamespaceCache) { 11095 if (auto Std = getStdNamespace()) { 11096 LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"), 11097 SourceLocation(), LookupNamespaceName); 11098 if (!LookupQualifiedName(Result, Std) || 11099 !(StdExperimentalNamespaceCache = 11100 Result.getAsSingle<NamespaceDecl>())) 11101 Result.suppressDiagnostics(); 11102 } 11103 } 11104 return StdExperimentalNamespaceCache; 11105} 11106 11107namespace { 11108 11109enum UnsupportedSTLSelect { 11110 USS_InvalidMember, 11111 USS_MissingMember, 11112 USS_NonTrivial, 11113 USS_Other 11114}; 11115 11116struct InvalidSTLDiagnoser { 11117 Sema &S; 11118 SourceLocation Loc; 11119 QualType TyForDiags; 11120 11121 QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "", 11122 const VarDecl *VD = nullptr) { 11123 { 11124 auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported) 11125 << TyForDiags << ((int)Sel); 11126 if (Sel == USS_InvalidMember || Sel == USS_MissingMember) { 11127 assert(!Name.empty())((void)0); 11128 D << Name; 11129 } 11130 } 11131 if (Sel == USS_InvalidMember) { 11132 S.Diag(VD->getLocation(), diag::note_var_declared_here) 11133 << VD << VD->getSourceRange(); 11134 } 11135 return QualType(); 11136 } 11137}; 11138} // namespace 11139 11140QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind, 11141 SourceLocation Loc, 11142 ComparisonCategoryUsage Usage) { 11143 assert(getLangOpts().CPlusPlus &&((void)0) 11144 "Looking for comparison category type outside of C++.")((void)0); 11145 11146 // Use an elaborated type for diagnostics which has a name containing the 11147 // prepended 'std' namespace but not any inline namespace names. 11148 auto TyForDiags = [&](ComparisonCategoryInfo *Info) { 11149 auto *NNS = 11150 NestedNameSpecifier::Create(Context, nullptr, getStdNamespace()); 11151 return Context.getElaboratedType(ETK_None, NNS, Info->getType()); 11152 }; 11153 11154 // Check if we've already successfully checked the comparison category type 11155 // before. If so, skip checking it again. 11156 ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind); 11157 if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) { 11158 // The only thing we need to check is that the type has a reachable 11159 // definition in the current context. 11160 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type)) 11161 return QualType(); 11162 11163 return Info->getType(); 11164 } 11165 11166 // If lookup failed 11167 if (!Info) { 11168 std::string NameForDiags = "std::"; 11169 NameForDiags += ComparisonCategories::getCategoryString(Kind); 11170 Diag(Loc, diag::err_implied_comparison_category_type_not_found) 11171 << NameForDiags << (int)Usage; 11172 return QualType(); 11173 } 11174 11175 assert(Info->Kind == Kind)((void)0); 11176 assert(Info->Record)((void)0); 11177 11178 // Update the Record decl in case we encountered a forward declaration on our 11179 // first pass. FIXME: This is a bit of a hack. 11180 if (Info->Record->hasDefinition()) 11181 Info->Record = Info->Record->getDefinition(); 11182 11183 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type)) 11184 return QualType(); 11185 11186 InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)}; 11187 11188 if (!Info->Record->isTriviallyCopyable()) 11189 return UnsupportedSTLError(USS_NonTrivial); 11190 11191 for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) { 11192 CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl(); 11193 // Tolerate empty base classes. 11194 if (Base->isEmpty()) 11195 continue; 11196 // Reject STL implementations which have at least one non-empty base. 11197 return UnsupportedSTLError(); 11198 } 11199 11200 // Check that the STL has implemented the types using a single integer field. 11201 // This expectation allows better codegen for builtin operators. We require: 11202 // (1) The class has exactly one field. 11203 // (2) The field is an integral or enumeration type. 11204 auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end(); 11205 if (std::distance(FIt, FEnd) != 1 || 11206 !FIt->getType()->isIntegralOrEnumerationType()) { 11207 return UnsupportedSTLError(); 11208 } 11209 11210 // Build each of the require values and store them in Info. 11211 for (ComparisonCategoryResult CCR : 11212 ComparisonCategories::getPossibleResultsForType(Kind)) { 11213 StringRef MemName = ComparisonCategories::getResultString(CCR); 11214 ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR); 11215 11216 if (!ValInfo) 11217 return UnsupportedSTLError(USS_MissingMember, MemName); 11218 11219 VarDecl *VD = ValInfo->VD; 11220 assert(VD && "should not be null!")((void)0); 11221 11222 // Attempt to diagnose reasons why the STL definition of this type 11223 // might be foobar, including it failing to be a constant expression. 11224 // TODO Handle more ways the lookup or result can be invalid. 11225 if (!VD->isStaticDataMember() || 11226 !VD->isUsableInConstantExpressions(Context)) 11227 return UnsupportedSTLError(USS_InvalidMember, MemName, VD); 11228 11229 // Attempt to evaluate the var decl as a constant expression and extract 11230 // the value of its first field as a ICE. If this fails, the STL 11231 // implementation is not supported. 11232 if (!ValInfo->hasValidIntValue()) 11233 return UnsupportedSTLError(); 11234 11235 MarkVariableReferenced(Loc, VD); 11236 } 11237 11238 // We've successfully built the required types and expressions. Update 11239 // the cache and return the newly cached value. 11240 FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true; 11241 return Info->getType(); 11242} 11243 11244/// Retrieve the special "std" namespace, which may require us to 11245/// implicitly define the namespace. 11246NamespaceDecl *Sema::getOrCreateStdNamespace() { 11247 if (!StdNamespace) { 11248 // The "std" namespace has not yet been defined, so build one implicitly. 11249 StdNamespace = NamespaceDecl::Create(Context, 11250 Context.getTranslationUnitDecl(), 11251 /*Inline=*/false, 11252 SourceLocation(), SourceLocation(), 11253 &PP.getIdentifierTable().get("std"), 11254 /*PrevDecl=*/nullptr); 11255 getStdNamespace()->setImplicit(true); 11256 } 11257 11258 return getStdNamespace(); 11259} 11260 11261bool Sema::isStdInitializerList(QualType Ty, QualType *Element) { 11262 assert(getLangOpts().CPlusPlus &&((void)0) 11263 "Looking for std::initializer_list outside of C++.")((void)0); 11264 11265 // We're looking for implicit instantiations of 11266 // template <typename E> class std::initializer_list. 11267 11268 if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it. 11269 return false; 11270 11271 ClassTemplateDecl *Template = nullptr; 11272 const TemplateArgument *Arguments = nullptr; 11273 11274 if (const RecordType *RT = Ty->getAs<RecordType>()) { 11275 11276 ClassTemplateSpecializationDecl *Specialization = 11277 dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl()); 11278 if (!Specialization) 11279 return false; 11280 11281 Template = Specialization->getSpecializedTemplate(); 11282 Arguments = Specialization->getTemplateArgs().data(); 11283 } else if (const TemplateSpecializationType *TST = 11284 Ty->getAs<TemplateSpecializationType>()) { 11285 Template = dyn_cast_or_null<ClassTemplateDecl>( 11286 TST->getTemplateName().getAsTemplateDecl()); 11287 Arguments = TST->getArgs(); 11288 } 11289 if (!Template) 11290 return false; 11291 11292 if (!StdInitializerList) { 11293 // Haven't recognized std::initializer_list yet, maybe this is it. 11294 CXXRecordDecl *TemplateClass = Template->getTemplatedDecl(); 11295 if (TemplateClass->getIdentifier() != 11296 &PP.getIdentifierTable().get("initializer_list") || 11297 !getStdNamespace()->InEnclosingNamespaceSetOf( 11298 TemplateClass->getDeclContext())) 11299 return false; 11300 // This is a template called std::initializer_list, but is it the right 11301 // template? 11302 TemplateParameterList *Params = Template->getTemplateParameters(); 11303 if (Params->getMinRequiredArguments() != 1) 11304 return false; 11305 if (!isa<TemplateTypeParmDecl>(Params->getParam(0))) 11306 return false; 11307 11308 // It's the right template. 11309 StdInitializerList = Template; 11310 } 11311 11312 if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl()) 11313 return false; 11314 11315 // This is an instance of std::initializer_list. Find the argument type. 11316 if (Element) 11317 *Element = Arguments[0].getAsType(); 11318 return true; 11319} 11320 11321static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){ 11322 NamespaceDecl *Std = S.getStdNamespace(); 11323 if (!Std) { 11324 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); 11325 return nullptr; 11326 } 11327 11328 LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"), 11329 Loc, Sema::LookupOrdinaryName); 11330 if (!S.LookupQualifiedName(Result, Std)) { 11331 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found); 11332 return nullptr; 11333 } 11334 ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>(); 11335 if (!Template) { 11336 Result.suppressDiagnostics(); 11337 // We found something weird. Complain about the first thing we found. 11338 NamedDecl *Found = *Result.begin(); 11339 S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list); 11340 return nullptr; 11341 } 11342 11343 // We found some template called std::initializer_list. Now verify that it's 11344 // correct. 11345 TemplateParameterList *Params = Template->getTemplateParameters(); 11346 if (Params->getMinRequiredArguments() != 1 || 11347 !isa<TemplateTypeParmDecl>(Params->getParam(0))) { 11348 S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list); 11349 return nullptr; 11350 } 11351 11352 return Template; 11353} 11354 11355QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) { 11356 if (!StdInitializerList) { 11357 StdInitializerList = LookupStdInitializerList(*this, Loc); 11358 if (!StdInitializerList) 11359 return QualType(); 11360 } 11361 11362 TemplateArgumentListInfo Args(Loc, Loc); 11363 Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element), 11364 Context.getTrivialTypeSourceInfo(Element, 11365 Loc))); 11366 return Context.getCanonicalType( 11367 CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args)); 11368} 11369 11370bool Sema::isInitListConstructor(const FunctionDecl *Ctor) { 11371 // C++ [dcl.init.list]p2: 11372 // A constructor is an initializer-list constructor if its first parameter 11373 // is of type std::initializer_list<E> or reference to possibly cv-qualified 11374 // std::initializer_list<E> for some type E, and either there are no other 11375 // parameters or else all other parameters have default arguments. 11376 if (!Ctor->hasOneParamOrDefaultArgs()) 11377 return false; 11378 11379 QualType ArgType = Ctor->getParamDecl(0)->getType(); 11380 if (const ReferenceType *RT = ArgType->getAs<ReferenceType>()) 11381 ArgType = RT->getPointeeType().getUnqualifiedType(); 11382 11383 return isStdInitializerList(ArgType, nullptr); 11384} 11385 11386/// Determine whether a using statement is in a context where it will be 11387/// apply in all contexts. 11388static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) { 11389 switch (CurContext->getDeclKind()) { 11390 case Decl::TranslationUnit: 11391 return true; 11392 case Decl::LinkageSpec: 11393 return IsUsingDirectiveInToplevelContext(CurContext->getParent()); 11394 default: 11395 return false; 11396 } 11397} 11398 11399namespace { 11400 11401// Callback to only accept typo corrections that are namespaces. 11402class NamespaceValidatorCCC final : public CorrectionCandidateCallback { 11403public: 11404 bool ValidateCandidate(const TypoCorrection &candidate) override { 11405 if (NamedDecl *ND = candidate.getCorrectionDecl()) 11406 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); 11407 return false; 11408 } 11409 11410 std::unique_ptr<CorrectionCandidateCallback> clone() override { 11411 return std::make_unique<NamespaceValidatorCCC>(*this); 11412 } 11413}; 11414 11415} 11416 11417static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc, 11418 CXXScopeSpec &SS, 11419 SourceLocation IdentLoc, 11420 IdentifierInfo *Ident) { 11421 R.clear(); 11422 NamespaceValidatorCCC CCC{}; 11423 if (TypoCorrection Corrected = 11424 S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC, 11425 Sema::CTK_ErrorRecovery)) { 11426 if (DeclContext *DC = S.computeDeclContext(SS, false)) { 11427 std::string CorrectedStr(Corrected.getAsString(S.getLangOpts())); 11428 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && 11429 Ident->getName().equals(CorrectedStr); 11430 S.diagnoseTypo(Corrected, 11431 S.PDiag(diag::err_using_directive_member_suggest) 11432 << Ident << DC << DroppedSpecifier << SS.getRange(), 11433 S.PDiag(diag::note_namespace_defined_here)); 11434 } else { 11435 S.diagnoseTypo(Corrected, 11436 S.PDiag(diag::err_using_directive_suggest) << Ident, 11437 S.PDiag(diag::note_namespace_defined_here)); 11438 } 11439 R.addDecl(Corrected.getFoundDecl()); 11440 return true; 11441 } 11442 return false; 11443} 11444 11445Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc, 11446 SourceLocation NamespcLoc, CXXScopeSpec &SS, 11447 SourceLocation IdentLoc, 11448 IdentifierInfo *NamespcName, 11449 const ParsedAttributesView &AttrList) { 11450 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")((void)0); 11451 assert(NamespcName && "Invalid NamespcName.")((void)0); 11452 assert(IdentLoc.isValid() && "Invalid NamespceName location.")((void)0); 11453 11454 // This can only happen along a recovery path. 11455 while (S->isTemplateParamScope()) 11456 S = S->getParent(); 11457 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")((void)0); 11458 11459 UsingDirectiveDecl *UDir = nullptr; 11460 NestedNameSpecifier *Qualifier = nullptr; 11461 if (SS.isSet()) 11462 Qualifier = SS.getScopeRep(); 11463 11464 // Lookup namespace name. 11465 LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName); 11466 LookupParsedName(R, S, &SS); 11467 if (R.isAmbiguous()) 11468 return nullptr; 11469 11470 if (R.empty()) { 11471 R.clear(); 11472 // Allow "using namespace std;" or "using namespace ::std;" even if 11473 // "std" hasn't been defined yet, for GCC compatibility. 11474 if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) && 11475 NamespcName->isStr("std")) { 11476 Diag(IdentLoc, diag::ext_using_undefined_std); 11477 R.addDecl(getOrCreateStdNamespace()); 11478 R.resolveKind(); 11479 } 11480 // Otherwise, attempt typo correction. 11481 else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName); 11482 } 11483 11484 if (!R.empty()) { 11485 NamedDecl *Named = R.getRepresentativeDecl(); 11486 NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>(); 11487 assert(NS && "expected namespace decl")((void)0); 11488 11489 // The use of a nested name specifier may trigger deprecation warnings. 11490 DiagnoseUseOfDecl(Named, IdentLoc); 11491 11492 // C++ [namespace.udir]p1: 11493 // A using-directive specifies that the names in the nominated 11494 // namespace can be used in the scope in which the 11495 // using-directive appears after the using-directive. During 11496 // unqualified name lookup (3.4.1), the names appear as if they 11497 // were declared in the nearest enclosing namespace which 11498 // contains both the using-directive and the nominated 11499 // namespace. [Note: in this context, "contains" means "contains 11500 // directly or indirectly". ] 11501 11502 // Find enclosing context containing both using-directive and 11503 // nominated namespace. 11504 DeclContext *CommonAncestor = NS; 11505 while (CommonAncestor && !CommonAncestor->Encloses(CurContext)) 11506 CommonAncestor = CommonAncestor->getParent(); 11507 11508 UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc, 11509 SS.getWithLocInContext(Context), 11510 IdentLoc, Named, CommonAncestor); 11511 11512 if (IsUsingDirectiveInToplevelContext(CurContext) && 11513 !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) { 11514 Diag(IdentLoc, diag::warn_using_directive_in_header); 11515 } 11516 11517 PushUsingDirective(S, UDir); 11518 } else { 11519 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); 11520 } 11521 11522 if (UDir) 11523 ProcessDeclAttributeList(S, UDir, AttrList); 11524 11525 return UDir; 11526} 11527 11528void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) { 11529 // If the scope has an associated entity and the using directive is at 11530 // namespace or translation unit scope, add the UsingDirectiveDecl into 11531 // its lookup structure so qualified name lookup can find it. 11532 DeclContext *Ctx = S->getEntity(); 11533 if (Ctx && !Ctx->isFunctionOrMethod()) 11534 Ctx->addDecl(UDir); 11535 else 11536 // Otherwise, it is at block scope. The using-directives will affect lookup 11537 // only to the end of the scope. 11538 S->PushUsingDirective(UDir); 11539} 11540 11541Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS, 11542 SourceLocation UsingLoc, 11543 SourceLocation TypenameLoc, CXXScopeSpec &SS, 11544 UnqualifiedId &Name, 11545 SourceLocation EllipsisLoc, 11546 const ParsedAttributesView &AttrList) { 11547 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.")((void)0); 11548 11549 if (SS.isEmpty()) { 11550 Diag(Name.getBeginLoc(), diag::err_using_requires_qualname); 11551 return nullptr; 11552 } 11553 11554 switch (Name.getKind()) { 11555 case UnqualifiedIdKind::IK_ImplicitSelfParam: 11556 case UnqualifiedIdKind::IK_Identifier: 11557 case UnqualifiedIdKind::IK_OperatorFunctionId: 11558 case UnqualifiedIdKind::IK_LiteralOperatorId: 11559 case UnqualifiedIdKind::IK_ConversionFunctionId: 11560 break; 11561 11562 case UnqualifiedIdKind::IK_ConstructorName: 11563 case UnqualifiedIdKind::IK_ConstructorTemplateId: 11564 // C++11 inheriting constructors. 11565 Diag(Name.getBeginLoc(), 11566 getLangOpts().CPlusPlus11 11567 ? diag::warn_cxx98_compat_using_decl_constructor 11568 : diag::err_using_decl_constructor) 11569 << SS.getRange(); 11570 11571 if (getLangOpts().CPlusPlus11) break; 11572 11573 return nullptr; 11574 11575 case UnqualifiedIdKind::IK_DestructorName: 11576 Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange(); 11577 return nullptr; 11578 11579 case UnqualifiedIdKind::IK_TemplateId: 11580 Diag(Name.getBeginLoc(), diag::err_using_decl_template_id) 11581 << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc); 11582 return nullptr; 11583 11584 case UnqualifiedIdKind::IK_DeductionGuideName: 11585 llvm_unreachable("cannot parse qualified deduction guide name")__builtin_unreachable(); 11586 } 11587 11588 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name); 11589 DeclarationName TargetName = TargetNameInfo.getName(); 11590 if (!TargetName) 11591 return nullptr; 11592 11593 // Warn about access declarations. 11594 if (UsingLoc.isInvalid()) { 11595 Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11 11596 ? diag::err_access_decl 11597 : diag::warn_access_decl_deprecated) 11598 << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using "); 11599 } 11600 11601 if (EllipsisLoc.isInvalid()) { 11602 if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) || 11603 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration)) 11604 return nullptr; 11605 } else { 11606 if (!SS.getScopeRep()->containsUnexpandedParameterPack() && 11607 !TargetNameInfo.containsUnexpandedParameterPack()) { 11608 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) 11609 << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc()); 11610 EllipsisLoc = SourceLocation(); 11611 } 11612 } 11613 11614 NamedDecl *UD = 11615 BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc, 11616 SS, TargetNameInfo, EllipsisLoc, AttrList, 11617 /*IsInstantiation*/ false, 11618 AttrList.hasAttribute(ParsedAttr::AT_UsingIfExists)); 11619 if (UD) 11620 PushOnScopeChains(UD, S, /*AddToContext*/ false); 11621 11622 return UD; 11623} 11624 11625Decl *Sema::ActOnUsingEnumDeclaration(Scope *S, AccessSpecifier AS, 11626 SourceLocation UsingLoc, 11627 SourceLocation EnumLoc, 11628 const DeclSpec &DS) { 11629 switch (DS.getTypeSpecType()) { 11630 case DeclSpec::TST_error: 11631 // This will already have been diagnosed 11632 return nullptr; 11633 11634 case DeclSpec::TST_enum: 11635 break; 11636 11637 case DeclSpec::TST_typename: 11638 Diag(DS.getTypeSpecTypeLoc(), diag::err_using_enum_is_dependent); 11639 return nullptr; 11640 11641 default: 11642 llvm_unreachable("unexpected DeclSpec type")__builtin_unreachable(); 11643 } 11644 11645 // As with enum-decls, we ignore attributes for now. 11646 auto *Enum = cast<EnumDecl>(DS.getRepAsDecl()); 11647 if (auto *Def = Enum->getDefinition()) 11648 Enum = Def; 11649 11650 auto *UD = BuildUsingEnumDeclaration(S, AS, UsingLoc, EnumLoc, 11651 DS.getTypeSpecTypeNameLoc(), Enum); 11652 if (UD) 11653 PushOnScopeChains(UD, S, /*AddToContext*/ false); 11654 11655 return UD; 11656} 11657 11658/// Determine whether a using declaration considers the given 11659/// declarations as "equivalent", e.g., if they are redeclarations of 11660/// the same entity or are both typedefs of the same type. 11661static bool 11662IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) { 11663 if (D1->getCanonicalDecl() == D2->getCanonicalDecl()) 11664 return true; 11665 11666 if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1)) 11667 if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2)) 11668 return Context.hasSameType(TD1->getUnderlyingType(), 11669 TD2->getUnderlyingType()); 11670 11671 // Two using_if_exists using-declarations are equivalent if both are 11672 // unresolved. 11673 if (isa<UnresolvedUsingIfExistsDecl>(D1) && 11674 isa<UnresolvedUsingIfExistsDecl>(D2)) 11675 return true; 11676 11677 return false; 11678} 11679 11680 11681/// Determines whether to create a using shadow decl for a particular 11682/// decl, given the set of decls existing prior to this using lookup. 11683bool Sema::CheckUsingShadowDecl(BaseUsingDecl *BUD, NamedDecl *Orig, 11684 const LookupResult &Previous, 11685 UsingShadowDecl *&PrevShadow) { 11686 // Diagnose finding a decl which is not from a base class of the 11687 // current class. We do this now because there are cases where this 11688 // function will silently decide not to build a shadow decl, which 11689 // will pre-empt further diagnostics. 11690 // 11691 // We don't need to do this in C++11 because we do the check once on 11692 // the qualifier. 11693 // 11694 // FIXME: diagnose the following if we care enough: 11695 // struct A { int foo; }; 11696 // struct B : A { using A::foo; }; 11697 // template <class T> struct C : A {}; 11698 // template <class T> struct D : C<T> { using B::foo; } // <--- 11699 // This is invalid (during instantiation) in C++03 because B::foo 11700 // resolves to the using decl in B, which is not a base class of D<T>. 11701 // We can't diagnose it immediately because C<T> is an unknown 11702 // specialization. The UsingShadowDecl in D<T> then points directly 11703 // to A::foo, which will look well-formed when we instantiate. 11704 // The right solution is to not collapse the shadow-decl chain. 11705 if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) 11706 if (auto *Using = dyn_cast<UsingDecl>(BUD)) { 11707 DeclContext *OrigDC = Orig->getDeclContext(); 11708 11709 // Handle enums and anonymous structs. 11710 if (isa<EnumDecl>(OrigDC)) 11711 OrigDC = OrigDC->getParent(); 11712 CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC); 11713 while (OrigRec->isAnonymousStructOrUnion()) 11714 OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext()); 11715 11716 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) { 11717 if (OrigDC == CurContext) { 11718 Diag(Using->getLocation(), 11719 diag::err_using_decl_nested_name_specifier_is_current_class) 11720 << Using->getQualifierLoc().getSourceRange(); 11721 Diag(Orig->getLocation(), diag::note_using_decl_target); 11722 Using->setInvalidDecl(); 11723 return true; 11724 } 11725 11726 Diag(Using->getQualifierLoc().getBeginLoc(), 11727 diag::err_using_decl_nested_name_specifier_is_not_base_class) 11728 << Using->getQualifier() << cast<CXXRecordDecl>(CurContext) 11729 << Using->getQualifierLoc().getSourceRange(); 11730 Diag(Orig->getLocation(), diag::note_using_decl_target); 11731 Using->setInvalidDecl(); 11732 return true; 11733 } 11734 } 11735 11736 if (Previous.empty()) return false; 11737 11738 NamedDecl *Target = Orig; 11739 if (isa<UsingShadowDecl>(Target)) 11740 Target = cast<UsingShadowDecl>(Target)->getTargetDecl(); 11741 11742 // If the target happens to be one of the previous declarations, we 11743 // don't have a conflict. 11744 // 11745 // FIXME: but we might be increasing its access, in which case we 11746 // should redeclare it. 11747 NamedDecl *NonTag = nullptr, *Tag = nullptr; 11748 bool FoundEquivalentDecl = false; 11749 for (LookupResult::iterator I = Previous.begin(), E = Previous.end(); 11750 I != E; ++I) { 11751 NamedDecl *D = (*I)->getUnderlyingDecl(); 11752 // We can have UsingDecls in our Previous results because we use the same 11753 // LookupResult for checking whether the UsingDecl itself is a valid 11754 // redeclaration. 11755 if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D) || isa<UsingEnumDecl>(D)) 11756 continue; 11757 11758 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) { 11759 // C++ [class.mem]p19: 11760 // If T is the name of a class, then [every named member other than 11761 // a non-static data member] shall have a name different from T 11762 if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) && 11763 !isa<IndirectFieldDecl>(Target) && 11764 !isa<UnresolvedUsingValueDecl>(Target) && 11765 DiagnoseClassNameShadow( 11766 CurContext, 11767 DeclarationNameInfo(BUD->getDeclName(), BUD->getLocation()))) 11768 return true; 11769 } 11770 11771 if (IsEquivalentForUsingDecl(Context, D, Target)) { 11772 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I)) 11773 PrevShadow = Shadow; 11774 FoundEquivalentDecl = true; 11775 } else if (isEquivalentInternalLinkageDeclaration(D, Target)) { 11776 // We don't conflict with an existing using shadow decl of an equivalent 11777 // declaration, but we're not a redeclaration of it. 11778 FoundEquivalentDecl = true; 11779 } 11780 11781 if (isVisible(D)) 11782 (isa<TagDecl>(D) ? Tag : NonTag) = D; 11783 } 11784 11785 if (FoundEquivalentDecl) 11786 return false; 11787 11788 // Always emit a diagnostic for a mismatch between an unresolved 11789 // using_if_exists and a resolved using declaration in either direction. 11790 if (isa<UnresolvedUsingIfExistsDecl>(Target) != 11791 (isa_and_nonnull<UnresolvedUsingIfExistsDecl>(NonTag))) { 11792 if (!NonTag && !Tag) 11793 return false; 11794 Diag(BUD->getLocation(), diag::err_using_decl_conflict); 11795 Diag(Target->getLocation(), diag::note_using_decl_target); 11796 Diag((NonTag ? NonTag : Tag)->getLocation(), 11797 diag::note_using_decl_conflict); 11798 BUD->setInvalidDecl(); 11799 return true; 11800 } 11801 11802 if (FunctionDecl *FD = Target->getAsFunction()) { 11803 NamedDecl *OldDecl = nullptr; 11804 switch (CheckOverload(nullptr, FD, Previous, OldDecl, 11805 /*IsForUsingDecl*/ true)) { 11806 case Ovl_Overload: 11807 return false; 11808 11809 case Ovl_NonFunction: 11810 Diag(BUD->getLocation(), diag::err_using_decl_conflict); 11811 break; 11812 11813 // We found a decl with the exact signature. 11814 case Ovl_Match: 11815 // If we're in a record, we want to hide the target, so we 11816 // return true (without a diagnostic) to tell the caller not to 11817 // build a shadow decl. 11818 if (CurContext->isRecord()) 11819 return true; 11820 11821 // If we're not in a record, this is an error. 11822 Diag(BUD->getLocation(), diag::err_using_decl_conflict); 11823 break; 11824 } 11825 11826 Diag(Target->getLocation(), diag::note_using_decl_target); 11827 Diag(OldDecl->getLocation(), diag::note_using_decl_conflict); 11828 BUD->setInvalidDecl(); 11829 return true; 11830 } 11831 11832 // Target is not a function. 11833 11834 if (isa<TagDecl>(Target)) { 11835 // No conflict between a tag and a non-tag. 11836 if (!Tag) return false; 11837 11838 Diag(BUD->getLocation(), diag::err_using_decl_conflict); 11839 Diag(Target->getLocation(), diag::note_using_decl_target); 11840 Diag(Tag->getLocation(), diag::note_using_decl_conflict); 11841 BUD->setInvalidDecl(); 11842 return true; 11843 } 11844 11845 // No conflict between a tag and a non-tag. 11846 if (!NonTag) return false; 11847 11848 Diag(BUD->getLocation(), diag::err_using_decl_conflict); 11849 Diag(Target->getLocation(), diag::note_using_decl_target); 11850 Diag(NonTag->getLocation(), diag::note_using_decl_conflict); 11851 BUD->setInvalidDecl(); 11852 return true; 11853} 11854 11855/// Determine whether a direct base class is a virtual base class. 11856static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) { 11857 if (!Derived->getNumVBases()) 11858 return false; 11859 for (auto &B : Derived->bases()) 11860 if (B.getType()->getAsCXXRecordDecl() == Base) 11861 return B.isVirtual(); 11862 llvm_unreachable("not a direct base class")__builtin_unreachable(); 11863} 11864 11865/// Builds a shadow declaration corresponding to a 'using' declaration. 11866UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S, BaseUsingDecl *BUD, 11867 NamedDecl *Orig, 11868 UsingShadowDecl *PrevDecl) { 11869 // If we resolved to another shadow declaration, just coalesce them. 11870 NamedDecl *Target = Orig; 11871 if (isa<UsingShadowDecl>(Target)) { 11872 Target = cast<UsingShadowDecl>(Target)->getTargetDecl(); 11873 assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration")((void)0); 11874 } 11875 11876 NamedDecl *NonTemplateTarget = Target; 11877 if (auto *TargetTD = dyn_cast<TemplateDecl>(Target)) 11878 NonTemplateTarget = TargetTD->getTemplatedDecl(); 11879 11880 UsingShadowDecl *Shadow; 11881 if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) { 11882 UsingDecl *Using = cast<UsingDecl>(BUD); 11883 bool IsVirtualBase = 11884 isVirtualDirectBase(cast<CXXRecordDecl>(CurContext), 11885 Using->getQualifier()->getAsRecordDecl()); 11886 Shadow = ConstructorUsingShadowDecl::Create( 11887 Context, CurContext, Using->getLocation(), Using, Orig, IsVirtualBase); 11888 } else { 11889 Shadow = UsingShadowDecl::Create(Context, CurContext, BUD->getLocation(), 11890 Target->getDeclName(), BUD, Target); 11891 } 11892 BUD->addShadowDecl(Shadow); 11893 11894 Shadow->setAccess(BUD->getAccess()); 11895 if (Orig->isInvalidDecl() || BUD->isInvalidDecl()) 11896 Shadow->setInvalidDecl(); 11897 11898 Shadow->setPreviousDecl(PrevDecl); 11899 11900 if (S) 11901 PushOnScopeChains(Shadow, S); 11902 else 11903 CurContext->addDecl(Shadow); 11904 11905 11906 return Shadow; 11907} 11908 11909/// Hides a using shadow declaration. This is required by the current 11910/// using-decl implementation when a resolvable using declaration in a 11911/// class is followed by a declaration which would hide or override 11912/// one or more of the using decl's targets; for example: 11913/// 11914/// struct Base { void foo(int); }; 11915/// struct Derived : Base { 11916/// using Base::foo; 11917/// void foo(int); 11918/// }; 11919/// 11920/// The governing language is C++03 [namespace.udecl]p12: 11921/// 11922/// When a using-declaration brings names from a base class into a 11923/// derived class scope, member functions in the derived class 11924/// override and/or hide member functions with the same name and 11925/// parameter types in a base class (rather than conflicting). 11926/// 11927/// There are two ways to implement this: 11928/// (1) optimistically create shadow decls when they're not hidden 11929/// by existing declarations, or 11930/// (2) don't create any shadow decls (or at least don't make them 11931/// visible) until we've fully parsed/instantiated the class. 11932/// The problem with (1) is that we might have to retroactively remove 11933/// a shadow decl, which requires several O(n) operations because the 11934/// decl structures are (very reasonably) not designed for removal. 11935/// (2) avoids this but is very fiddly and phase-dependent. 11936void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) { 11937 if (Shadow->getDeclName().getNameKind() == 11938 DeclarationName::CXXConversionFunctionName) 11939 cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow); 11940 11941 // Remove it from the DeclContext... 11942 Shadow->getDeclContext()->removeDecl(Shadow); 11943 11944 // ...and the scope, if applicable... 11945 if (S) { 11946 S->RemoveDecl(Shadow); 11947 IdResolver.RemoveDecl(Shadow); 11948 } 11949 11950 // ...and the using decl. 11951 Shadow->getIntroducer()->removeShadowDecl(Shadow); 11952 11953 // TODO: complain somehow if Shadow was used. It shouldn't 11954 // be possible for this to happen, because...? 11955} 11956 11957/// Find the base specifier for a base class with the given type. 11958static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived, 11959 QualType DesiredBase, 11960 bool &AnyDependentBases) { 11961 // Check whether the named type is a direct base class. 11962 CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified() 11963 .getUnqualifiedType(); 11964 for (auto &Base : Derived->bases()) { 11965 CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified(); 11966 if (CanonicalDesiredBase == BaseType) 11967 return &Base; 11968 if (BaseType->isDependentType()) 11969 AnyDependentBases = true; 11970 } 11971 return nullptr; 11972} 11973 11974namespace { 11975class UsingValidatorCCC final : public CorrectionCandidateCallback { 11976public: 11977 UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation, 11978 NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf) 11979 : HasTypenameKeyword(HasTypenameKeyword), 11980 IsInstantiation(IsInstantiation), OldNNS(NNS), 11981 RequireMemberOf(RequireMemberOf) {} 11982 11983 bool ValidateCandidate(const TypoCorrection &Candidate) override { 11984 NamedDecl *ND = Candidate.getCorrectionDecl(); 11985 11986 // Keywords are not valid here. 11987 if (!ND || isa<NamespaceDecl>(ND)) 11988 return false; 11989 11990 // Completely unqualified names are invalid for a 'using' declaration. 11991 if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier()) 11992 return false; 11993 11994 // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would 11995 // reject. 11996 11997 if (RequireMemberOf) { 11998 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND); 11999 if (FoundRecord && FoundRecord->isInjectedClassName()) { 12000 // No-one ever wants a using-declaration to name an injected-class-name 12001 // of a base class, unless they're declaring an inheriting constructor. 12002 ASTContext &Ctx = ND->getASTContext(); 12003 if (!Ctx.getLangOpts().CPlusPlus11) 12004 return false; 12005 QualType FoundType = Ctx.getRecordType(FoundRecord); 12006 12007 // Check that the injected-class-name is named as a member of its own 12008 // type; we don't want to suggest 'using Derived::Base;', since that 12009 // means something else. 12010 NestedNameSpecifier *Specifier = 12011 Candidate.WillReplaceSpecifier() 12012 ? Candidate.getCorrectionSpecifier() 12013 : OldNNS; 12014 if (!Specifier->getAsType() || 12015 !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType)) 12016 return false; 12017 12018 // Check that this inheriting constructor declaration actually names a 12019 // direct base class of the current class. 12020 bool AnyDependentBases = false; 12021 if (!findDirectBaseWithType(RequireMemberOf, 12022 Ctx.getRecordType(FoundRecord), 12023 AnyDependentBases) && 12024 !AnyDependentBases) 12025 return false; 12026 } else { 12027 auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext()); 12028 if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD)) 12029 return false; 12030 12031 // FIXME: Check that the base class member is accessible? 12032 } 12033 } else { 12034 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND); 12035 if (FoundRecord && FoundRecord->isInjectedClassName()) 12036 return false; 12037 } 12038 12039 if (isa<TypeDecl>(ND)) 12040 return HasTypenameKeyword || !IsInstantiation; 12041 12042 return !HasTypenameKeyword; 12043 } 12044 12045 std::unique_ptr<CorrectionCandidateCallback> clone() override { 12046 return std::make_unique<UsingValidatorCCC>(*this); 12047 } 12048 12049private: 12050 bool HasTypenameKeyword; 12051 bool IsInstantiation; 12052 NestedNameSpecifier *OldNNS; 12053 CXXRecordDecl *RequireMemberOf; 12054}; 12055} // end anonymous namespace 12056 12057/// Remove decls we can't actually see from a lookup being used to declare 12058/// shadow using decls. 12059/// 12060/// \param S - The scope of the potential shadow decl 12061/// \param Previous - The lookup of a potential shadow decl's name. 12062void Sema::FilterUsingLookup(Scope *S, LookupResult &Previous) { 12063 // It is really dumb that we have to do this. 12064 LookupResult::Filter F = Previous.makeFilter(); 12065 while (F.hasNext()) { 12066 NamedDecl *D = F.next(); 12067 if (!isDeclInScope(D, CurContext, S)) 12068 F.erase(); 12069 // If we found a local extern declaration that's not ordinarily visible, 12070 // and this declaration is being added to a non-block scope, ignore it. 12071 // We're only checking for scope conflicts here, not also for violations 12072 // of the linkage rules. 12073 else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() && 12074 !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary)) 12075 F.erase(); 12076 } 12077 F.done(); 12078} 12079 12080/// Builds a using declaration. 12081/// 12082/// \param IsInstantiation - Whether this call arises from an 12083/// instantiation of an unresolved using declaration. We treat 12084/// the lookup differently for these declarations. 12085NamedDecl *Sema::BuildUsingDeclaration( 12086 Scope *S, AccessSpecifier AS, SourceLocation UsingLoc, 12087 bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS, 12088 DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc, 12089 const ParsedAttributesView &AttrList, bool IsInstantiation, 12090 bool IsUsingIfExists) { 12091 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.")((void)0); 12092 SourceLocation IdentLoc = NameInfo.getLoc(); 12093 assert(IdentLoc.isValid() && "Invalid TargetName location.")((void)0); 12094 12095 // FIXME: We ignore attributes for now. 12096 12097 // For an inheriting constructor declaration, the name of the using 12098 // declaration is the name of a constructor in this class, not in the 12099 // base class. 12100 DeclarationNameInfo UsingName = NameInfo; 12101 if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName) 12102 if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext)) 12103 UsingName.setName(Context.DeclarationNames.getCXXConstructorName( 12104 Context.getCanonicalType(Context.getRecordType(RD)))); 12105 12106 // Do the redeclaration lookup in the current scope. 12107 LookupResult Previous(*this, UsingName, LookupUsingDeclName, 12108 ForVisibleRedeclaration); 12109 Previous.setHideTags(false); 12110 if (S) { 12111 LookupName(Previous, S); 12112 12113 FilterUsingLookup(S, Previous); 12114 } else { 12115 assert(IsInstantiation && "no scope in non-instantiation")((void)0); 12116 if (CurContext->isRecord()) 12117 LookupQualifiedName(Previous, CurContext); 12118 else { 12119 // No redeclaration check is needed here; in non-member contexts we 12120 // diagnosed all possible conflicts with other using-declarations when 12121 // building the template: 12122 // 12123 // For a dependent non-type using declaration, the only valid case is 12124 // if we instantiate to a single enumerator. We check for conflicts 12125 // between shadow declarations we introduce, and we check in the template 12126 // definition for conflicts between a non-type using declaration and any 12127 // other declaration, which together covers all cases. 12128 // 12129 // A dependent typename using declaration will never successfully 12130 // instantiate, since it will always name a class member, so we reject 12131 // that in the template definition. 12132 } 12133 } 12134 12135 // Check for invalid redeclarations. 12136 if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword, 12137 SS, IdentLoc, Previous)) 12138 return nullptr; 12139 12140 // 'using_if_exists' doesn't make sense on an inherited constructor. 12141 if (IsUsingIfExists && UsingName.getName().getNameKind() == 12142 DeclarationName::CXXConstructorName) { 12143 Diag(UsingLoc, diag::err_using_if_exists_on_ctor); 12144 return nullptr; 12145 } 12146 12147 DeclContext *LookupContext = computeDeclContext(SS); 12148 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); 12149 if (!LookupContext || EllipsisLoc.isValid()) { 12150 NamedDecl *D; 12151 // Dependent scope, or an unexpanded pack 12152 if (!LookupContext && CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, 12153 SS, NameInfo, IdentLoc)) 12154 return nullptr; 12155 12156 if (HasTypenameKeyword) { 12157 // FIXME: not all declaration name kinds are legal here 12158 D = UnresolvedUsingTypenameDecl::Create(Context, CurContext, 12159 UsingLoc, TypenameLoc, 12160 QualifierLoc, 12161 IdentLoc, NameInfo.getName(), 12162 EllipsisLoc); 12163 } else { 12164 D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc, 12165 QualifierLoc, NameInfo, EllipsisLoc); 12166 } 12167 D->setAccess(AS); 12168 CurContext->addDecl(D); 12169 ProcessDeclAttributeList(S, D, AttrList); 12170 return D; 12171 } 12172 12173 auto Build = [&](bool Invalid) { 12174 UsingDecl *UD = 12175 UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc, 12176 UsingName, HasTypenameKeyword); 12177 UD->setAccess(AS); 12178 CurContext->addDecl(UD); 12179 ProcessDeclAttributeList(S, UD, AttrList); 12180 UD->setInvalidDecl(Invalid); 12181 return UD; 12182 }; 12183 auto BuildInvalid = [&]{ return Build(true); }; 12184 auto BuildValid = [&]{ return Build(false); }; 12185 12186 if (RequireCompleteDeclContext(SS, LookupContext)) 12187 return BuildInvalid(); 12188 12189 // Look up the target name. 12190 LookupResult R(*this, NameInfo, LookupOrdinaryName); 12191 12192 // Unlike most lookups, we don't always want to hide tag 12193 // declarations: tag names are visible through the using declaration 12194 // even if hidden by ordinary names, *except* in a dependent context 12195 // where it's important for the sanity of two-phase lookup. 12196 if (!IsInstantiation) 12197 R.setHideTags(false); 12198 12199 // For the purposes of this lookup, we have a base object type 12200 // equal to that of the current context. 12201 if (CurContext->isRecord()) { 12202 R.setBaseObjectType( 12203 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext))); 12204 } 12205 12206 LookupQualifiedName(R, LookupContext); 12207 12208 // Validate the context, now we have a lookup 12209 if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo, 12210 IdentLoc, &R)) 12211 return nullptr; 12212 12213 if (R.empty() && IsUsingIfExists) 12214 R.addDecl(UnresolvedUsingIfExistsDecl::Create(Context, CurContext, UsingLoc, 12215 UsingName.getName()), 12216 AS_public); 12217 12218 // Try to correct typos if possible. If constructor name lookup finds no 12219 // results, that means the named class has no explicit constructors, and we 12220 // suppressed declaring implicit ones (probably because it's dependent or 12221 // invalid). 12222 if (R.empty() && 12223 NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) { 12224 // HACK 2017-01-08: Work around an issue with libstdc++'s detection of 12225 // ::gets. Sometimes it believes that glibc provides a ::gets in cases where 12226 // it does not. The issue was fixed in libstdc++ 6.3 (2016-12-21) and later. 12227 auto *II = NameInfo.getName().getAsIdentifierInfo(); 12228 if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") && 12229 CurContext->isStdNamespace() && 12230 isa<TranslationUnitDecl>(LookupContext) && 12231 getSourceManager().isInSystemHeader(UsingLoc)) 12232 return nullptr; 12233 UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(), 12234 dyn_cast<CXXRecordDecl>(CurContext)); 12235 if (TypoCorrection Corrected = 12236 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC, 12237 CTK_ErrorRecovery)) { 12238 // We reject candidates where DroppedSpecifier == true, hence the 12239 // literal '0' below. 12240 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) 12241 << NameInfo.getName() << LookupContext << 0 12242 << SS.getRange()); 12243 12244 // If we picked a correction with no attached Decl we can't do anything 12245 // useful with it, bail out. 12246 NamedDecl *ND = Corrected.getCorrectionDecl(); 12247 if (!ND) 12248 return BuildInvalid(); 12249 12250 // If we corrected to an inheriting constructor, handle it as one. 12251 auto *RD = dyn_cast<CXXRecordDecl>(ND); 12252 if (RD && RD->isInjectedClassName()) { 12253 // The parent of the injected class name is the class itself. 12254 RD = cast<CXXRecordDecl>(RD->getParent()); 12255 12256 // Fix up the information we'll use to build the using declaration. 12257 if (Corrected.WillReplaceSpecifier()) { 12258 NestedNameSpecifierLocBuilder Builder; 12259 Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), 12260 QualifierLoc.getSourceRange()); 12261 QualifierLoc = Builder.getWithLocInContext(Context); 12262 } 12263 12264 // In this case, the name we introduce is the name of a derived class 12265 // constructor. 12266 auto *CurClass = cast<CXXRecordDecl>(CurContext); 12267 UsingName.setName(Context.DeclarationNames.getCXXConstructorName( 12268 Context.getCanonicalType(Context.getRecordType(CurClass)))); 12269 UsingName.setNamedTypeInfo(nullptr); 12270 for (auto *Ctor : LookupConstructors(RD)) 12271 R.addDecl(Ctor); 12272 R.resolveKind(); 12273 } else { 12274 // FIXME: Pick up all the declarations if we found an overloaded 12275 // function. 12276 UsingName.setName(ND->getDeclName()); 12277 R.addDecl(ND); 12278 } 12279 } else { 12280 Diag(IdentLoc, diag::err_no_member) 12281 << NameInfo.getName() << LookupContext << SS.getRange(); 12282 return BuildInvalid(); 12283 } 12284 } 12285 12286 if (R.isAmbiguous()) 12287 return BuildInvalid(); 12288 12289 if (HasTypenameKeyword) { 12290 // If we asked for a typename and got a non-type decl, error out. 12291 if (!R.getAsSingle<TypeDecl>() && 12292 !R.getAsSingle<UnresolvedUsingIfExistsDecl>()) { 12293 Diag(IdentLoc, diag::err_using_typename_non_type); 12294 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 12295 Diag((*I)->getUnderlyingDecl()->getLocation(), 12296 diag::note_using_decl_target); 12297 return BuildInvalid(); 12298 } 12299 } else { 12300 // If we asked for a non-typename and we got a type, error out, 12301 // but only if this is an instantiation of an unresolved using 12302 // decl. Otherwise just silently find the type name. 12303 if (IsInstantiation && R.getAsSingle<TypeDecl>()) { 12304 Diag(IdentLoc, diag::err_using_dependent_value_is_type); 12305 Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target); 12306 return BuildInvalid(); 12307 } 12308 } 12309 12310 // C++14 [namespace.udecl]p6: 12311 // A using-declaration shall not name a namespace. 12312 if (R.getAsSingle<NamespaceDecl>()) { 12313 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace) 12314 << SS.getRange(); 12315 return BuildInvalid(); 12316 } 12317 12318 UsingDecl *UD = BuildValid(); 12319 12320 // Some additional rules apply to inheriting constructors. 12321 if (UsingName.getName().getNameKind() == 12322 DeclarationName::CXXConstructorName) { 12323 // Suppress access diagnostics; the access check is instead performed at the 12324 // point of use for an inheriting constructor. 12325 R.suppressDiagnostics(); 12326 if (CheckInheritingConstructorUsingDecl(UD)) 12327 return UD; 12328 } 12329 12330 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { 12331 UsingShadowDecl *PrevDecl = nullptr; 12332 if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl)) 12333 BuildUsingShadowDecl(S, UD, *I, PrevDecl); 12334 } 12335 12336 return UD; 12337} 12338 12339NamedDecl *Sema::BuildUsingEnumDeclaration(Scope *S, AccessSpecifier AS, 12340 SourceLocation UsingLoc, 12341 SourceLocation EnumLoc, 12342 SourceLocation NameLoc, 12343 EnumDecl *ED) { 12344 bool Invalid = false; 12345 12346 if (CurContext->getRedeclContext()->isRecord()) { 12347 /// In class scope, check if this is a duplicate, for better a diagnostic. 12348 DeclarationNameInfo UsingEnumName(ED->getDeclName(), NameLoc); 12349 LookupResult Previous(*this, UsingEnumName, LookupUsingDeclName, 12350 ForVisibleRedeclaration); 12351 12352 LookupName(Previous, S); 12353 12354 for (NamedDecl *D : Previous) 12355 if (UsingEnumDecl *UED = dyn_cast<UsingEnumDecl>(D)) 12356 if (UED->getEnumDecl() == ED) { 12357 Diag(UsingLoc, diag::err_using_enum_decl_redeclaration) 12358 << SourceRange(EnumLoc, NameLoc); 12359 Diag(D->getLocation(), diag::note_using_enum_decl) << 1; 12360 Invalid = true; 12361 break; 12362 } 12363 } 12364 12365 if (RequireCompleteEnumDecl(ED, NameLoc)) 12366 Invalid = true; 12367 12368 UsingEnumDecl *UD = UsingEnumDecl::Create(Context, CurContext, UsingLoc, 12369 EnumLoc, NameLoc, ED); 12370 UD->setAccess(AS); 12371 CurContext->addDecl(UD); 12372 12373 if (Invalid) { 12374 UD->setInvalidDecl(); 12375 return UD; 12376 } 12377 12378 // Create the shadow decls for each enumerator 12379 for (EnumConstantDecl *EC : ED->enumerators()) { 12380 UsingShadowDecl *PrevDecl = nullptr; 12381 DeclarationNameInfo DNI(EC->getDeclName(), EC->getLocation()); 12382 LookupResult Previous(*this, DNI, LookupOrdinaryName, 12383 ForVisibleRedeclaration); 12384 LookupName(Previous, S); 12385 FilterUsingLookup(S, Previous); 12386 12387 if (!CheckUsingShadowDecl(UD, EC, Previous, PrevDecl)) 12388 BuildUsingShadowDecl(S, UD, EC, PrevDecl); 12389 } 12390 12391 return UD; 12392} 12393 12394NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom, 12395 ArrayRef<NamedDecl *> Expansions) { 12396 assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||((void)0) 12397 isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||((void)0) 12398 isa<UsingPackDecl>(InstantiatedFrom))((void)0); 12399 12400 auto *UPD = 12401 UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions); 12402 UPD->setAccess(InstantiatedFrom->getAccess()); 12403 CurContext->addDecl(UPD); 12404 return UPD; 12405} 12406 12407/// Additional checks for a using declaration referring to a constructor name. 12408bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) { 12409 assert(!UD->hasTypename() && "expecting a constructor name")((void)0); 12410 12411 const Type *SourceType = UD->getQualifier()->getAsType(); 12412 assert(SourceType &&((void)0) 12413 "Using decl naming constructor doesn't have type in scope spec.")((void)0); 12414 CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext); 12415 12416 // Check whether the named type is a direct base class. 12417 bool AnyDependentBases = false; 12418 auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0), 12419 AnyDependentBases); 12420 if (!Base && !AnyDependentBases) { 12421 Diag(UD->getUsingLoc(), 12422 diag::err_using_decl_constructor_not_in_direct_base) 12423 << UD->getNameInfo().getSourceRange() 12424 << QualType(SourceType, 0) << TargetClass; 12425 UD->setInvalidDecl(); 12426 return true; 12427 } 12428 12429 if (Base) 12430 Base->setInheritConstructors(); 12431 12432 return false; 12433} 12434 12435/// Checks that the given using declaration is not an invalid 12436/// redeclaration. Note that this is checking only for the using decl 12437/// itself, not for any ill-formedness among the UsingShadowDecls. 12438bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc, 12439 bool HasTypenameKeyword, 12440 const CXXScopeSpec &SS, 12441 SourceLocation NameLoc, 12442 const LookupResult &Prev) { 12443 NestedNameSpecifier *Qual = SS.getScopeRep(); 12444 12445 // C++03 [namespace.udecl]p8: 12446 // C++0x [namespace.udecl]p10: 12447 // A using-declaration is a declaration and can therefore be used 12448 // repeatedly where (and only where) multiple declarations are 12449 // allowed. 12450 // 12451 // That's in non-member contexts. 12452 if (!CurContext->getRedeclContext()->isRecord()) { 12453 // A dependent qualifier outside a class can only ever resolve to an 12454 // enumeration type. Therefore it conflicts with any other non-type 12455 // declaration in the same scope. 12456 // FIXME: How should we check for dependent type-type conflicts at block 12457 // scope? 12458 if (Qual->isDependent() && !HasTypenameKeyword) { 12459 for (auto *D : Prev) { 12460 if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) { 12461 bool OldCouldBeEnumerator = 12462 isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D); 12463 Diag(NameLoc, 12464 OldCouldBeEnumerator ? diag::err_redefinition 12465 : diag::err_redefinition_different_kind) 12466 << Prev.getLookupName(); 12467 Diag(D->getLocation(), diag::note_previous_definition); 12468 return true; 12469 } 12470 } 12471 } 12472 return false; 12473 } 12474 12475 const NestedNameSpecifier *CNNS = 12476 Context.getCanonicalNestedNameSpecifier(Qual); 12477 for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) { 12478 NamedDecl *D = *I; 12479 12480 bool DTypename; 12481 NestedNameSpecifier *DQual; 12482 if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) { 12483 DTypename = UD->hasTypename(); 12484 DQual = UD->getQualifier(); 12485 } else if (UnresolvedUsingValueDecl *UD 12486 = dyn_cast<UnresolvedUsingValueDecl>(D)) { 12487 DTypename = false; 12488 DQual = UD->getQualifier(); 12489 } else if (UnresolvedUsingTypenameDecl *UD 12490 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) { 12491 DTypename = true; 12492 DQual = UD->getQualifier(); 12493 } else continue; 12494 12495 // using decls differ if one says 'typename' and the other doesn't. 12496 // FIXME: non-dependent using decls? 12497 if (HasTypenameKeyword != DTypename) continue; 12498 12499 // using decls differ if they name different scopes (but note that 12500 // template instantiation can cause this check to trigger when it 12501 // didn't before instantiation). 12502 if (CNNS != Context.getCanonicalNestedNameSpecifier(DQual)) 12503 continue; 12504 12505 Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange(); 12506 Diag(D->getLocation(), diag::note_using_decl) << 1; 12507 return true; 12508 } 12509 12510 return false; 12511} 12512 12513/// Checks that the given nested-name qualifier used in a using decl 12514/// in the current context is appropriately related to the current 12515/// scope. If an error is found, diagnoses it and returns true. 12516/// R is nullptr, if the caller has not (yet) done a lookup, otherwise it's the 12517/// result of that lookup. UD is likewise nullptr, except when we have an 12518/// already-populated UsingDecl whose shadow decls contain the same information 12519/// (i.e. we're instantiating a UsingDecl with non-dependent scope). 12520bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc, bool HasTypename, 12521 const CXXScopeSpec &SS, 12522 const DeclarationNameInfo &NameInfo, 12523 SourceLocation NameLoc, 12524 const LookupResult *R, const UsingDecl *UD) { 12525 DeclContext *NamedContext = computeDeclContext(SS); 12526 assert(bool(NamedContext) == (R || UD) && !(R && UD) &&((void)0) 12527 "resolvable context must have exactly one set of decls")((void)0); 12528 12529 // C++ 20 permits using an enumerator that does not have a class-hierarchy 12530 // relationship. 12531 bool Cxx20Enumerator = false; 12532 if (NamedContext) { 12533 EnumConstantDecl *EC = nullptr; 12534 if (R) 12535 EC = R->getAsSingle<EnumConstantDecl>(); 12536 else if (UD && UD->shadow_size() == 1) 12537 EC = dyn_cast<EnumConstantDecl>(UD->shadow_begin()->getTargetDecl()); 12538 if (EC) 12539 Cxx20Enumerator = getLangOpts().CPlusPlus20; 12540 12541 if (auto *ED = dyn_cast<EnumDecl>(NamedContext)) { 12542 // C++14 [namespace.udecl]p7: 12543 // A using-declaration shall not name a scoped enumerator. 12544 // C++20 p1099 permits enumerators. 12545 if (EC && R && ED->isScoped()) 12546 Diag(SS.getBeginLoc(), 12547 getLangOpts().CPlusPlus20 12548 ? diag::warn_cxx17_compat_using_decl_scoped_enumerator 12549 : diag::ext_using_decl_scoped_enumerator) 12550 << SS.getRange(); 12551 12552 // We want to consider the scope of the enumerator 12553 NamedContext = ED->getDeclContext(); 12554 } 12555 } 12556 12557 if (!CurContext->isRecord()) { 12558 // C++03 [namespace.udecl]p3: 12559 // C++0x [namespace.udecl]p8: 12560 // A using-declaration for a class member shall be a member-declaration. 12561 // C++20 [namespace.udecl]p7 12562 // ... other than an enumerator ... 12563 12564 // If we weren't able to compute a valid scope, it might validly be a 12565 // dependent class or enumeration scope. If we have a 'typename' keyword, 12566 // the scope must resolve to a class type. 12567 if (NamedContext ? !NamedContext->getRedeclContext()->isRecord() 12568 : !HasTypename) 12569 return false; // OK 12570 12571 Diag(NameLoc, 12572 Cxx20Enumerator 12573 ? diag::warn_cxx17_compat_using_decl_class_member_enumerator 12574 : diag::err_using_decl_can_not_refer_to_class_member) 12575 << SS.getRange(); 12576 12577 if (Cxx20Enumerator) 12578 return false; // OK 12579 12580 auto *RD = NamedContext 12581 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext()) 12582 : nullptr; 12583 if (RD && !RequireCompleteDeclContext(const_cast<CXXScopeSpec &>(SS), RD)) { 12584 // See if there's a helpful fixit 12585 12586 if (!R) { 12587 // We will have already diagnosed the problem on the template 12588 // definition, Maybe we should do so again? 12589 } else if (R->getAsSingle<TypeDecl>()) { 12590 if (getLangOpts().CPlusPlus11) { 12591 // Convert 'using X::Y;' to 'using Y = X::Y;'. 12592 Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround) 12593 << 0 // alias declaration 12594 << FixItHint::CreateInsertion(SS.getBeginLoc(), 12595 NameInfo.getName().getAsString() + 12596 " = "); 12597 } else { 12598 // Convert 'using X::Y;' to 'typedef X::Y Y;'. 12599 SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc()); 12600 Diag(InsertLoc, diag::note_using_decl_class_member_workaround) 12601 << 1 // typedef declaration 12602 << FixItHint::CreateReplacement(UsingLoc, "typedef") 12603 << FixItHint::CreateInsertion( 12604 InsertLoc, " " + NameInfo.getName().getAsString()); 12605 } 12606 } else if (R->getAsSingle<VarDecl>()) { 12607 // Don't provide a fixit outside C++11 mode; we don't want to suggest 12608 // repeating the type of the static data member here. 12609 FixItHint FixIt; 12610 if (getLangOpts().CPlusPlus11) { 12611 // Convert 'using X::Y;' to 'auto &Y = X::Y;'. 12612 FixIt = FixItHint::CreateReplacement( 12613 UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = "); 12614 } 12615 12616 Diag(UsingLoc, diag::note_using_decl_class_member_workaround) 12617 << 2 // reference declaration 12618 << FixIt; 12619 } else if (R->getAsSingle<EnumConstantDecl>()) { 12620 // Don't provide a fixit outside C++11 mode; we don't want to suggest 12621 // repeating the type of the enumeration here, and we can't do so if 12622 // the type is anonymous. 12623 FixItHint FixIt; 12624 if (getLangOpts().CPlusPlus11) { 12625 // Convert 'using X::Y;' to 'auto &Y = X::Y;'. 12626 FixIt = FixItHint::CreateReplacement( 12627 UsingLoc, 12628 "constexpr auto " + NameInfo.getName().getAsString() + " = "); 12629 } 12630 12631 Diag(UsingLoc, diag::note_using_decl_class_member_workaround) 12632 << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable 12633 << FixIt; 12634 } 12635 } 12636 12637 return true; // Fail 12638 } 12639 12640 // If the named context is dependent, we can't decide much. 12641 if (!NamedContext) { 12642 // FIXME: in C++0x, we can diagnose if we can prove that the 12643 // nested-name-specifier does not refer to a base class, which is 12644 // still possible in some cases. 12645 12646 // Otherwise we have to conservatively report that things might be 12647 // okay. 12648 return false; 12649 } 12650 12651 // The current scope is a record. 12652 if (!NamedContext->isRecord()) { 12653 // Ideally this would point at the last name in the specifier, 12654 // but we don't have that level of source info. 12655 Diag(SS.getBeginLoc(), 12656 Cxx20Enumerator 12657 ? diag::warn_cxx17_compat_using_decl_non_member_enumerator 12658 : diag::err_using_decl_nested_name_specifier_is_not_class) 12659 << SS.getScopeRep() << SS.getRange(); 12660 12661 if (Cxx20Enumerator) 12662 return false; // OK 12663 12664 return true; 12665 } 12666 12667 if (!NamedContext->isDependentContext() && 12668 RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext)) 12669 return true; 12670 12671 if (getLangOpts().CPlusPlus11) { 12672 // C++11 [namespace.udecl]p3: 12673 // In a using-declaration used as a member-declaration, the 12674 // nested-name-specifier shall name a base class of the class 12675 // being defined. 12676 12677 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom( 12678 cast<CXXRecordDecl>(NamedContext))) { 12679 12680 if (Cxx20Enumerator) { 12681 Diag(NameLoc, diag::warn_cxx17_compat_using_decl_non_member_enumerator) 12682 << SS.getRange(); 12683 return false; 12684 } 12685 12686 if (CurContext == NamedContext) { 12687 Diag(SS.getBeginLoc(), 12688 diag::err_using_decl_nested_name_specifier_is_current_class) 12689 << SS.getRange(); 12690 return !getLangOpts().CPlusPlus20; 12691 } 12692 12693 if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) { 12694 Diag(SS.getBeginLoc(), 12695 diag::err_using_decl_nested_name_specifier_is_not_base_class) 12696 << SS.getScopeRep() << cast<CXXRecordDecl>(CurContext) 12697 << SS.getRange(); 12698 } 12699 return true; 12700 } 12701 12702 return false; 12703 } 12704 12705 // C++03 [namespace.udecl]p4: 12706 // A using-declaration used as a member-declaration shall refer 12707 // to a member of a base class of the class being defined [etc.]. 12708 12709 // Salient point: SS doesn't have to name a base class as long as 12710 // lookup only finds members from base classes. Therefore we can 12711 // diagnose here only if we can prove that that can't happen, 12712 // i.e. if the class hierarchies provably don't intersect. 12713 12714 // TODO: it would be nice if "definitely valid" results were cached 12715 // in the UsingDecl and UsingShadowDecl so that these checks didn't 12716 // need to be repeated. 12717 12718 llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases; 12719 auto Collect = [&Bases](const CXXRecordDecl *Base) { 12720 Bases.insert(Base); 12721 return true; 12722 }; 12723 12724 // Collect all bases. Return false if we find a dependent base. 12725 if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect)) 12726 return false; 12727 12728 // Returns true if the base is dependent or is one of the accumulated base 12729 // classes. 12730 auto IsNotBase = [&Bases](const CXXRecordDecl *Base) { 12731 return !Bases.count(Base); 12732 }; 12733 12734 // Return false if the class has a dependent base or if it or one 12735 // of its bases is present in the base set of the current context. 12736 if (Bases.count(cast<CXXRecordDecl>(NamedContext)) || 12737 !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase)) 12738 return false; 12739 12740 Diag(SS.getRange().getBegin(), 12741 diag::err_using_decl_nested_name_specifier_is_not_base_class) 12742 << SS.getScopeRep() 12743 << cast<CXXRecordDecl>(CurContext) 12744 << SS.getRange(); 12745 12746 return true; 12747} 12748 12749Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS, 12750 MultiTemplateParamsArg TemplateParamLists, 12751 SourceLocation UsingLoc, UnqualifiedId &Name, 12752 const ParsedAttributesView &AttrList, 12753 TypeResult Type, Decl *DeclFromDeclSpec) { 12754 // Skip up to the relevant declaration scope. 12755 while (S->isTemplateParamScope()) 12756 S = S->getParent(); 12757 assert((S->getFlags() & Scope::DeclScope) &&((void)0) 12758 "got alias-declaration outside of declaration scope")((void)0); 12759 12760 if (Type.isInvalid()) 12761 return nullptr; 12762 12763 bool Invalid = false; 12764 DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name); 12765 TypeSourceInfo *TInfo = nullptr; 12766 GetTypeFromParser(Type.get(), &TInfo); 12767 12768 if (DiagnoseClassNameShadow(CurContext, NameInfo)) 12769 return nullptr; 12770 12771 if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo, 12772 UPPC_DeclarationType)) { 12773 Invalid = true; 12774 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, 12775 TInfo->getTypeLoc().getBeginLoc()); 12776 } 12777 12778 LookupResult Previous(*this, NameInfo, LookupOrdinaryName, 12779 TemplateParamLists.size() 12780 ? forRedeclarationInCurContext() 12781 : ForVisibleRedeclaration); 12782 LookupName(Previous, S); 12783 12784 // Warn about shadowing the name of a template parameter. 12785 if (Previous.isSingleResult() && 12786 Previous.getFoundDecl()->isTemplateParameter()) { 12787 DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl()); 12788 Previous.clear(); 12789 } 12790 12791 assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&((void)0) 12792 "name in alias declaration must be an identifier")((void)0); 12793 TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc, 12794 Name.StartLocation, 12795 Name.Identifier, TInfo); 12796 12797 NewTD->setAccess(AS); 12798 12799 if (Invalid) 12800 NewTD->setInvalidDecl(); 12801 12802 ProcessDeclAttributeList(S, NewTD, AttrList); 12803 AddPragmaAttributes(S, NewTD); 12804 12805 CheckTypedefForVariablyModifiedType(S, NewTD); 12806 Invalid |= NewTD->isInvalidDecl(); 12807 12808 bool Redeclaration = false; 12809 12810 NamedDecl *NewND; 12811 if (TemplateParamLists.size()) { 12812 TypeAliasTemplateDecl *OldDecl = nullptr; 12813 TemplateParameterList *OldTemplateParams = nullptr; 12814 12815 if (TemplateParamLists.size() != 1) { 12816 Diag(UsingLoc, diag::err_alias_template_extra_headers) 12817 << SourceRange(TemplateParamLists[1]->getTemplateLoc(), 12818 TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc()); 12819 } 12820 TemplateParameterList *TemplateParams = TemplateParamLists[0]; 12821 12822 // Check that we can declare a template here. 12823 if (CheckTemplateDeclScope(S, TemplateParams)) 12824 return nullptr; 12825 12826 // Only consider previous declarations in the same scope. 12827 FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false, 12828 /*ExplicitInstantiationOrSpecialization*/false); 12829 if (!Previous.empty()) { 12830 Redeclaration = true; 12831 12832 OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>(); 12833 if (!OldDecl && !Invalid) { 12834 Diag(UsingLoc, diag::err_redefinition_different_kind) 12835 << Name.Identifier; 12836 12837 NamedDecl *OldD = Previous.getRepresentativeDecl(); 12838 if (OldD->getLocation().isValid()) 12839 Diag(OldD->getLocation(), diag::note_previous_definition); 12840 12841 Invalid = true; 12842 } 12843 12844 if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) { 12845 if (TemplateParameterListsAreEqual(TemplateParams, 12846 OldDecl->getTemplateParameters(), 12847 /*Complain=*/true, 12848 TPL_TemplateMatch)) 12849 OldTemplateParams = 12850 OldDecl->getMostRecentDecl()->getTemplateParameters(); 12851 else 12852 Invalid = true; 12853 12854 TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl(); 12855 if (!Invalid && 12856 !Context.hasSameType(OldTD->getUnderlyingType(), 12857 NewTD->getUnderlyingType())) { 12858 // FIXME: The C++0x standard does not clearly say this is ill-formed, 12859 // but we can't reasonably accept it. 12860 Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef) 12861 << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType(); 12862 if (OldTD->getLocation().isValid()) 12863 Diag(OldTD->getLocation(), diag::note_previous_definition); 12864 Invalid = true; 12865 } 12866 } 12867 } 12868 12869 // Merge any previous default template arguments into our parameters, 12870 // and check the parameter list. 12871 if (CheckTemplateParameterList(TemplateParams, OldTemplateParams, 12872 TPC_TypeAliasTemplate)) 12873 return nullptr; 12874 12875 TypeAliasTemplateDecl *NewDecl = 12876 TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc, 12877 Name.Identifier, TemplateParams, 12878 NewTD); 12879 NewTD->setDescribedAliasTemplate(NewDecl); 12880 12881 NewDecl->setAccess(AS); 12882 12883 if (Invalid) 12884 NewDecl->setInvalidDecl(); 12885 else if (OldDecl) { 12886 NewDecl->setPreviousDecl(OldDecl); 12887 CheckRedeclarationModuleOwnership(NewDecl, OldDecl); 12888 } 12889 12890 NewND = NewDecl; 12891 } else { 12892 if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) { 12893 setTagNameForLinkagePurposes(TD, NewTD); 12894 handleTagNumbering(TD, S); 12895 } 12896 ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration); 12897 NewND = NewTD; 12898 } 12899 12900 PushOnScopeChains(NewND, S); 12901 ActOnDocumentableDecl(NewND); 12902 return NewND; 12903} 12904 12905Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc, 12906 SourceLocation AliasLoc, 12907 IdentifierInfo *Alias, CXXScopeSpec &SS, 12908 SourceLocation IdentLoc, 12909 IdentifierInfo *Ident) { 12910 12911 // Lookup the namespace name. 12912 LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName); 12913 LookupParsedName(R, S, &SS); 12914 12915 if (R.isAmbiguous()) 12916 return nullptr; 12917 12918 if (R.empty()) { 12919 if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) { 12920 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange(); 12921 return nullptr; 12922 } 12923 } 12924 assert(!R.isAmbiguous() && !R.empty())((void)0); 12925 NamedDecl *ND = R.getRepresentativeDecl(); 12926 12927 // Check if we have a previous declaration with the same name. 12928 LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName, 12929 ForVisibleRedeclaration); 12930 LookupName(PrevR, S); 12931 12932 // Check we're not shadowing a template parameter. 12933 if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) { 12934 DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl()); 12935 PrevR.clear(); 12936 } 12937 12938 // Filter out any other lookup result from an enclosing scope. 12939 FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false, 12940 /*AllowInlineNamespace*/false); 12941 12942 // Find the previous declaration and check that we can redeclare it. 12943 NamespaceAliasDecl *Prev = nullptr; 12944 if (PrevR.isSingleResult()) { 12945 NamedDecl *PrevDecl = PrevR.getRepresentativeDecl(); 12946 if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) { 12947 // We already have an alias with the same name that points to the same 12948 // namespace; check that it matches. 12949 if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) { 12950 Prev = AD; 12951 } else if (isVisible(PrevDecl)) { 12952 Diag(AliasLoc, diag::err_redefinition_different_namespace_alias) 12953 << Alias; 12954 Diag(AD->getLocation(), diag::note_previous_namespace_alias) 12955 << AD->getNamespace(); 12956 return nullptr; 12957 } 12958 } else if (isVisible(PrevDecl)) { 12959 unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl()) 12960 ? diag::err_redefinition 12961 : diag::err_redefinition_different_kind; 12962 Diag(AliasLoc, DiagID) << Alias; 12963 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 12964 return nullptr; 12965 } 12966 } 12967 12968 // The use of a nested name specifier may trigger deprecation warnings. 12969 DiagnoseUseOfDecl(ND, IdentLoc); 12970 12971 NamespaceAliasDecl *AliasDecl = 12972 NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc, 12973 Alias, SS.getWithLocInContext(Context), 12974 IdentLoc, ND); 12975 if (Prev) 12976 AliasDecl->setPreviousDecl(Prev); 12977 12978 PushOnScopeChains(AliasDecl, S); 12979 return AliasDecl; 12980} 12981 12982namespace { 12983struct SpecialMemberExceptionSpecInfo 12984 : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> { 12985 SourceLocation Loc; 12986 Sema::ImplicitExceptionSpecification ExceptSpec; 12987 12988 SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD, 12989 Sema::CXXSpecialMember CSM, 12990 Sema::InheritedConstructorInfo *ICI, 12991 SourceLocation Loc) 12992 : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {} 12993 12994 bool visitBase(CXXBaseSpecifier *Base); 12995 bool visitField(FieldDecl *FD); 12996 12997 void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj, 12998 unsigned Quals); 12999 13000 void visitSubobjectCall(Subobject Subobj, 13001 Sema::SpecialMemberOverloadResult SMOR); 13002}; 13003} 13004 13005bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) { 13006 auto *RT = Base->getType()->getAs<RecordType>(); 13007 if (!RT) 13008 return false; 13009 13010 auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl()); 13011 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass); 13012 if (auto *BaseCtor = SMOR.getMethod()) { 13013 visitSubobjectCall(Base, BaseCtor); 13014 return false; 13015 } 13016 13017 visitClassSubobject(BaseClass, Base, 0); 13018 return false; 13019} 13020 13021bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) { 13022 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) { 13023 Expr *E = FD->getInClassInitializer(); 13024 if (!E) 13025 // FIXME: It's a little wasteful to build and throw away a 13026 // CXXDefaultInitExpr here. 13027 // FIXME: We should have a single context note pointing at Loc, and 13028 // this location should be MD->getLocation() instead, since that's 13029 // the location where we actually use the default init expression. 13030 E = S.BuildCXXDefaultInitExpr(Loc, FD).get(); 13031 if (E) 13032 ExceptSpec.CalledExpr(E); 13033 } else if (auto *RT = S.Context.getBaseElementType(FD->getType()) 13034 ->getAs<RecordType>()) { 13035 visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD, 13036 FD->getType().getCVRQualifiers()); 13037 } 13038 return false; 13039} 13040 13041void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class, 13042 Subobject Subobj, 13043 unsigned Quals) { 13044 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>(); 13045 bool IsMutable = Field && Field->isMutable(); 13046 visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable)); 13047} 13048 13049void SpecialMemberExceptionSpecInfo::visitSubobjectCall( 13050 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) { 13051 // Note, if lookup fails, it doesn't matter what exception specification we 13052 // choose because the special member will be deleted. 13053 if (CXXMethodDecl *MD = SMOR.getMethod()) 13054 ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD); 13055} 13056 13057bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) { 13058 llvm::APSInt Result; 13059 ExprResult Converted = CheckConvertedConstantExpression( 13060 ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool); 13061 ExplicitSpec.setExpr(Converted.get()); 13062 if (Converted.isUsable() && !Converted.get()->isValueDependent()) { 13063 ExplicitSpec.setKind(Result.getBoolValue() 13064 ? ExplicitSpecKind::ResolvedTrue 13065 : ExplicitSpecKind::ResolvedFalse); 13066 return true; 13067 } 13068 ExplicitSpec.setKind(ExplicitSpecKind::Unresolved); 13069 return false; 13070} 13071 13072ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) { 13073 ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved); 13074 if (!ExplicitExpr->isTypeDependent()) 13075 tryResolveExplicitSpecifier(ES); 13076 return ES; 13077} 13078 13079static Sema::ImplicitExceptionSpecification 13080ComputeDefaultedSpecialMemberExceptionSpec( 13081 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM, 13082 Sema::InheritedConstructorInfo *ICI) { 13083 ComputingExceptionSpec CES(S, MD, Loc); 13084 13085 CXXRecordDecl *ClassDecl = MD->getParent(); 13086 13087 // C++ [except.spec]p14: 13088 // An implicitly declared special member function (Clause 12) shall have an 13089 // exception-specification. [...] 13090 SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation()); 13091 if (ClassDecl->isInvalidDecl()) 13092 return Info.ExceptSpec; 13093 13094 // FIXME: If this diagnostic fires, we're probably missing a check for 13095 // attempting to resolve an exception specification before it's known 13096 // at a higher level. 13097 if (S.RequireCompleteType(MD->getLocation(), 13098 S.Context.getRecordType(ClassDecl), 13099 diag::err_exception_spec_incomplete_type)) 13100 return Info.ExceptSpec; 13101 13102 // C++1z [except.spec]p7: 13103 // [Look for exceptions thrown by] a constructor selected [...] to 13104 // initialize a potentially constructed subobject, 13105 // C++1z [except.spec]p8: 13106 // The exception specification for an implicitly-declared destructor, or a 13107 // destructor without a noexcept-specifier, is potentially-throwing if and 13108 // only if any of the destructors for any of its potentially constructed 13109 // subojects is potentially throwing. 13110 // FIXME: We respect the first rule but ignore the "potentially constructed" 13111 // in the second rule to resolve a core issue (no number yet) that would have 13112 // us reject: 13113 // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; }; 13114 // struct B : A {}; 13115 // struct C : B { void f(); }; 13116 // ... due to giving B::~B() a non-throwing exception specification. 13117 Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases 13118 : Info.VisitAllBases); 13119 13120 return Info.ExceptSpec; 13121} 13122 13123namespace { 13124/// RAII object to register a special member as being currently declared. 13125struct DeclaringSpecialMember { 13126 Sema &S; 13127 Sema::SpecialMemberDecl D; 13128 Sema::ContextRAII SavedContext; 13129 bool WasAlreadyBeingDeclared; 13130 13131 DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM) 13132 : S(S), D(RD, CSM), SavedContext(S, RD) { 13133 WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second; 13134 if (WasAlreadyBeingDeclared) 13135 // This almost never happens, but if it does, ensure that our cache 13136 // doesn't contain a stale result. 13137 S.SpecialMemberCache.clear(); 13138 else { 13139 // Register a note to be produced if we encounter an error while 13140 // declaring the special member. 13141 Sema::CodeSynthesisContext Ctx; 13142 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember; 13143 // FIXME: We don't have a location to use here. Using the class's 13144 // location maintains the fiction that we declare all special members 13145 // with the class, but (1) it's not clear that lying about that helps our 13146 // users understand what's going on, and (2) there may be outer contexts 13147 // on the stack (some of which are relevant) and printing them exposes 13148 // our lies. 13149 Ctx.PointOfInstantiation = RD->getLocation(); 13150 Ctx.Entity = RD; 13151 Ctx.SpecialMember = CSM; 13152 S.pushCodeSynthesisContext(Ctx); 13153 } 13154 } 13155 ~DeclaringSpecialMember() { 13156 if (!WasAlreadyBeingDeclared) { 13157 S.SpecialMembersBeingDeclared.erase(D); 13158 S.popCodeSynthesisContext(); 13159 } 13160 } 13161 13162 /// Are we already trying to declare this special member? 13163 bool isAlreadyBeingDeclared() const { 13164 return WasAlreadyBeingDeclared; 13165 } 13166}; 13167} 13168 13169void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) { 13170 // Look up any existing declarations, but don't trigger declaration of all 13171 // implicit special members with this name. 13172 DeclarationName Name = FD->getDeclName(); 13173 LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName, 13174 ForExternalRedeclaration); 13175 for (auto *D : FD->getParent()->lookup(Name)) 13176 if (auto *Acceptable = R.getAcceptableDecl(D)) 13177 R.addDecl(Acceptable); 13178 R.resolveKind(); 13179 R.suppressDiagnostics(); 13180 13181 CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false); 13182} 13183 13184void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem, 13185 QualType ResultTy, 13186 ArrayRef<QualType> Args) { 13187 // Build an exception specification pointing back at this constructor. 13188 FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem); 13189 13190 LangAS AS = getDefaultCXXMethodAddrSpace(); 13191 if (AS != LangAS::Default) { 13192 EPI.TypeQuals.addAddressSpace(AS); 13193 } 13194 13195 auto QT = Context.getFunctionType(ResultTy, Args, EPI); 13196 SpecialMem->setType(QT); 13197 13198 // During template instantiation of implicit special member functions we need 13199 // a reliable TypeSourceInfo for the function prototype in order to allow 13200 // functions to be substituted. 13201 if (inTemplateInstantiation() && 13202 cast<CXXRecordDecl>(SpecialMem->getParent())->isLambda()) { 13203 TypeSourceInfo *TSI = 13204 Context.getTrivialTypeSourceInfo(SpecialMem->getType()); 13205 SpecialMem->setTypeSourceInfo(TSI); 13206 } 13207} 13208 13209CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor( 13210 CXXRecordDecl *ClassDecl) { 13211 // C++ [class.ctor]p5: 13212 // A default constructor for a class X is a constructor of class X 13213 // that can be called without an argument. If there is no 13214 // user-declared constructor for class X, a default constructor is 13215 // implicitly declared. An implicitly-declared default constructor 13216 // is an inline public member of its class. 13217 assert(ClassDecl->needsImplicitDefaultConstructor() &&((void)0) 13218 "Should not build implicit default constructor!")((void)0); 13219 13220 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor); 13221 if (DSM.isAlreadyBeingDeclared()) 13222 return nullptr; 13223 13224 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 13225 CXXDefaultConstructor, 13226 false); 13227 13228 // Create the actual constructor declaration. 13229 CanQualType ClassType 13230 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); 13231 SourceLocation ClassLoc = ClassDecl->getLocation(); 13232 DeclarationName Name 13233 = Context.DeclarationNames.getCXXConstructorName(ClassType); 13234 DeclarationNameInfo NameInfo(Name, ClassLoc); 13235 CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create( 13236 Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(), 13237 /*TInfo=*/nullptr, ExplicitSpecifier(), 13238 /*isInline=*/true, /*isImplicitlyDeclared=*/true, 13239 Constexpr ? ConstexprSpecKind::Constexpr 13240 : ConstexprSpecKind::Unspecified); 13241 DefaultCon->setAccess(AS_public); 13242 DefaultCon->setDefaulted(); 13243 13244 if (getLangOpts().CUDA) { 13245 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor, 13246 DefaultCon, 13247 /* ConstRHS */ false, 13248 /* Diagnose */ false); 13249 } 13250 13251 setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None); 13252 13253 // We don't need to use SpecialMemberIsTrivial here; triviality for default 13254 // constructors is easy to compute. 13255 DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor()); 13256 13257 // Note that we have declared this constructor. 13258 ++getASTContext().NumImplicitDefaultConstructorsDeclared; 13259 13260 Scope *S = getScopeForContext(ClassDecl); 13261 CheckImplicitSpecialMemberDeclaration(S, DefaultCon); 13262 13263 if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor)) 13264 SetDeclDeleted(DefaultCon, ClassLoc); 13265 13266 if (S) 13267 PushOnScopeChains(DefaultCon, S, false); 13268 ClassDecl->addDecl(DefaultCon); 13269 13270 return DefaultCon; 13271} 13272 13273void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation, 13274 CXXConstructorDecl *Constructor) { 13275 assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&((void)0) 13276 !Constructor->doesThisDeclarationHaveABody() &&((void)0) 13277 !Constructor->isDeleted()) &&((void)0) 13278 "DefineImplicitDefaultConstructor - call it for implicit default ctor")((void)0); 13279 if (Constructor->willHaveBody() || Constructor->isInvalidDecl()) 13280 return; 13281 13282 CXXRecordDecl *ClassDecl = Constructor->getParent(); 13283 assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor")((void)0); 13284 13285 SynthesizedFunctionScope Scope(*this, Constructor); 13286 13287 // The exception specification is needed because we are defining the 13288 // function. 13289 ResolveExceptionSpec(CurrentLocation, 13290 Constructor->getType()->castAs<FunctionProtoType>()); 13291 MarkVTableUsed(CurrentLocation, ClassDecl); 13292 13293 // Add a context note for diagnostics produced after this point. 13294 Scope.addContextNote(CurrentLocation); 13295 13296 if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) { 13297 Constructor->setInvalidDecl(); 13298 return; 13299 } 13300 13301 SourceLocation Loc = Constructor->getEndLoc().isValid() 13302 ? Constructor->getEndLoc() 13303 : Constructor->getLocation(); 13304 Constructor->setBody(new (Context) CompoundStmt(Loc)); 13305 Constructor->markUsed(Context); 13306 13307 if (ASTMutationListener *L = getASTMutationListener()) { 13308 L->CompletedImplicitDefinition(Constructor); 13309 } 13310 13311 DiagnoseUninitializedFields(*this, Constructor); 13312} 13313 13314void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) { 13315 // Perform any delayed checks on exception specifications. 13316 CheckDelayedMemberExceptionSpecs(); 13317} 13318 13319/// Find or create the fake constructor we synthesize to model constructing an 13320/// object of a derived class via a constructor of a base class. 13321CXXConstructorDecl * 13322Sema::findInheritingConstructor(SourceLocation Loc, 13323 CXXConstructorDecl *BaseCtor, 13324 ConstructorUsingShadowDecl *Shadow) { 13325 CXXRecordDecl *Derived = Shadow->getParent(); 13326 SourceLocation UsingLoc = Shadow->getLocation(); 13327 13328 // FIXME: Add a new kind of DeclarationName for an inherited constructor. 13329 // For now we use the name of the base class constructor as a member of the 13330 // derived class to indicate a (fake) inherited constructor name. 13331 DeclarationName Name = BaseCtor->getDeclName(); 13332 13333 // Check to see if we already have a fake constructor for this inherited 13334 // constructor call. 13335 for (NamedDecl *Ctor : Derived->lookup(Name)) 13336 if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor) 13337 ->getInheritedConstructor() 13338 .getConstructor(), 13339 BaseCtor)) 13340 return cast<CXXConstructorDecl>(Ctor); 13341 13342 DeclarationNameInfo NameInfo(Name, UsingLoc); 13343 TypeSourceInfo *TInfo = 13344 Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc); 13345 FunctionProtoTypeLoc ProtoLoc = 13346 TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>(); 13347 13348 // Check the inherited constructor is valid and find the list of base classes 13349 // from which it was inherited. 13350 InheritedConstructorInfo ICI(*this, Loc, Shadow); 13351 13352 bool Constexpr = 13353 BaseCtor->isConstexpr() && 13354 defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor, 13355 false, BaseCtor, &ICI); 13356 13357 CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create( 13358 Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo, 13359 BaseCtor->getExplicitSpecifier(), /*isInline=*/true, 13360 /*isImplicitlyDeclared=*/true, 13361 Constexpr ? BaseCtor->getConstexprKind() : ConstexprSpecKind::Unspecified, 13362 InheritedConstructor(Shadow, BaseCtor), 13363 BaseCtor->getTrailingRequiresClause()); 13364 if (Shadow->isInvalidDecl()) 13365 DerivedCtor->setInvalidDecl(); 13366 13367 // Build an unevaluated exception specification for this fake constructor. 13368 const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>(); 13369 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); 13370 EPI.ExceptionSpec.Type = EST_Unevaluated; 13371 EPI.ExceptionSpec.SourceDecl = DerivedCtor; 13372 DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(), 13373 FPT->getParamTypes(), EPI)); 13374 13375 // Build the parameter declarations. 13376 SmallVector<ParmVarDecl *, 16> ParamDecls; 13377 for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) { 13378 TypeSourceInfo *TInfo = 13379 Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc); 13380 ParmVarDecl *PD = ParmVarDecl::Create( 13381 Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr, 13382 FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr); 13383 PD->setScopeInfo(0, I); 13384 PD->setImplicit(); 13385 // Ensure attributes are propagated onto parameters (this matters for 13386 // format, pass_object_size, ...). 13387 mergeDeclAttributes(PD, BaseCtor->getParamDecl(I)); 13388 ParamDecls.push_back(PD); 13389 ProtoLoc.setParam(I, PD); 13390 } 13391 13392 // Set up the new constructor. 13393 assert(!BaseCtor->isDeleted() && "should not use deleted constructor")((void)0); 13394 DerivedCtor->setAccess(BaseCtor->getAccess()); 13395 DerivedCtor->setParams(ParamDecls); 13396 Derived->addDecl(DerivedCtor); 13397 13398 if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI)) 13399 SetDeclDeleted(DerivedCtor, UsingLoc); 13400 13401 return DerivedCtor; 13402} 13403 13404void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) { 13405 InheritedConstructorInfo ICI(*this, Ctor->getLocation(), 13406 Ctor->getInheritedConstructor().getShadowDecl()); 13407 ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI, 13408 /*Diagnose*/true); 13409} 13410 13411void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation, 13412 CXXConstructorDecl *Constructor) { 13413 CXXRecordDecl *ClassDecl = Constructor->getParent(); 13414 assert(Constructor->getInheritedConstructor() &&((void)0) 13415 !Constructor->doesThisDeclarationHaveABody() &&((void)0) 13416 !Constructor->isDeleted())((void)0); 13417 if (Constructor->willHaveBody() || Constructor->isInvalidDecl()) 13418 return; 13419 13420 // Initializations are performed "as if by a defaulted default constructor", 13421 // so enter the appropriate scope. 13422 SynthesizedFunctionScope Scope(*this, Constructor); 13423 13424 // The exception specification is needed because we are defining the 13425 // function. 13426 ResolveExceptionSpec(CurrentLocation, 13427 Constructor->getType()->castAs<FunctionProtoType>()); 13428 MarkVTableUsed(CurrentLocation, ClassDecl); 13429 13430 // Add a context note for diagnostics produced after this point. 13431 Scope.addContextNote(CurrentLocation); 13432 13433 ConstructorUsingShadowDecl *Shadow = 13434 Constructor->getInheritedConstructor().getShadowDecl(); 13435 CXXConstructorDecl *InheritedCtor = 13436 Constructor->getInheritedConstructor().getConstructor(); 13437 13438 // [class.inhctor.init]p1: 13439 // initialization proceeds as if a defaulted default constructor is used to 13440 // initialize the D object and each base class subobject from which the 13441 // constructor was inherited 13442 13443 InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow); 13444 CXXRecordDecl *RD = Shadow->getParent(); 13445 SourceLocation InitLoc = Shadow->getLocation(); 13446 13447 // Build explicit initializers for all base classes from which the 13448 // constructor was inherited. 13449 SmallVector<CXXCtorInitializer*, 8> Inits; 13450 for (bool VBase : {false, true}) { 13451 for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) { 13452 if (B.isVirtual() != VBase) 13453 continue; 13454 13455 auto *BaseRD = B.getType()->getAsCXXRecordDecl(); 13456 if (!BaseRD) 13457 continue; 13458 13459 auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor); 13460 if (!BaseCtor.first) 13461 continue; 13462 13463 MarkFunctionReferenced(CurrentLocation, BaseCtor.first); 13464 ExprResult Init = new (Context) CXXInheritedCtorInitExpr( 13465 InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second); 13466 13467 auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc); 13468 Inits.push_back(new (Context) CXXCtorInitializer( 13469 Context, TInfo, VBase, InitLoc, Init.get(), InitLoc, 13470 SourceLocation())); 13471 } 13472 } 13473 13474 // We now proceed as if for a defaulted default constructor, with the relevant 13475 // initializers replaced. 13476 13477 if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) { 13478 Constructor->setInvalidDecl(); 13479 return; 13480 } 13481 13482 Constructor->setBody(new (Context) CompoundStmt(InitLoc)); 13483 Constructor->markUsed(Context); 13484 13485 if (ASTMutationListener *L = getASTMutationListener()) { 13486 L->CompletedImplicitDefinition(Constructor); 13487 } 13488 13489 DiagnoseUninitializedFields(*this, Constructor); 13490} 13491 13492CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) { 13493 // C++ [class.dtor]p2: 13494 // If a class has no user-declared destructor, a destructor is 13495 // declared implicitly. An implicitly-declared destructor is an 13496 // inline public member of its class. 13497 assert(ClassDecl->needsImplicitDestructor())((void)0); 13498 13499 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor); 13500 if (DSM.isAlreadyBeingDeclared()) 13501 return nullptr; 13502 13503 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 13504 CXXDestructor, 13505 false); 13506 13507 // Create the actual destructor declaration. 13508 CanQualType ClassType 13509 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl)); 13510 SourceLocation ClassLoc = ClassDecl->getLocation(); 13511 DeclarationName Name 13512 = Context.DeclarationNames.getCXXDestructorName(ClassType); 13513 DeclarationNameInfo NameInfo(Name, ClassLoc); 13514 CXXDestructorDecl *Destructor = 13515 CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo, 13516 QualType(), nullptr, /*isInline=*/true, 13517 /*isImplicitlyDeclared=*/true, 13518 Constexpr ? ConstexprSpecKind::Constexpr 13519 : ConstexprSpecKind::Unspecified); 13520 Destructor->setAccess(AS_public); 13521 Destructor->setDefaulted(); 13522 13523 if (getLangOpts().CUDA) { 13524 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor, 13525 Destructor, 13526 /* ConstRHS */ false, 13527 /* Diagnose */ false); 13528 } 13529 13530 setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None); 13531 13532 // We don't need to use SpecialMemberIsTrivial here; triviality for 13533 // destructors is easy to compute. 13534 Destructor->setTrivial(ClassDecl->hasTrivialDestructor()); 13535 Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() || 13536 ClassDecl->hasTrivialDestructorForCall()); 13537 13538 // Note that we have declared this destructor. 13539 ++getASTContext().NumImplicitDestructorsDeclared; 13540 13541 Scope *S = getScopeForContext(ClassDecl); 13542 CheckImplicitSpecialMemberDeclaration(S, Destructor); 13543 13544 // We can't check whether an implicit destructor is deleted before we complete 13545 // the definition of the class, because its validity depends on the alignment 13546 // of the class. We'll check this from ActOnFields once the class is complete. 13547 if (ClassDecl->isCompleteDefinition() && 13548 ShouldDeleteSpecialMember(Destructor, CXXDestructor)) 13549 SetDeclDeleted(Destructor, ClassLoc); 13550 13551 // Introduce this destructor into its scope. 13552 if (S) 13553 PushOnScopeChains(Destructor, S, false); 13554 ClassDecl->addDecl(Destructor); 13555 13556 return Destructor; 13557} 13558 13559void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation, 13560 CXXDestructorDecl *Destructor) { 13561 assert((Destructor->isDefaulted() &&((void)0) 13562 !Destructor->doesThisDeclarationHaveABody() &&((void)0) 13563 !Destructor->isDeleted()) &&((void)0) 13564 "DefineImplicitDestructor - call it for implicit default dtor")((void)0); 13565 if (Destructor->willHaveBody() || Destructor->isInvalidDecl()) 13566 return; 13567 13568 CXXRecordDecl *ClassDecl = Destructor->getParent(); 13569 assert(ClassDecl && "DefineImplicitDestructor - invalid destructor")((void)0); 13570 13571 SynthesizedFunctionScope Scope(*this, Destructor); 13572 13573 // The exception specification is needed because we are defining the 13574 // function. 13575 ResolveExceptionSpec(CurrentLocation, 13576 Destructor->getType()->castAs<FunctionProtoType>()); 13577 MarkVTableUsed(CurrentLocation, ClassDecl); 13578 13579 // Add a context note for diagnostics produced after this point. 13580 Scope.addContextNote(CurrentLocation); 13581 13582 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(), 13583 Destructor->getParent()); 13584 13585 if (CheckDestructor(Destructor)) { 13586 Destructor->setInvalidDecl(); 13587 return; 13588 } 13589 13590 SourceLocation Loc = Destructor->getEndLoc().isValid() 13591 ? Destructor->getEndLoc() 13592 : Destructor->getLocation(); 13593 Destructor->setBody(new (Context) CompoundStmt(Loc)); 13594 Destructor->markUsed(Context); 13595 13596 if (ASTMutationListener *L = getASTMutationListener()) { 13597 L->CompletedImplicitDefinition(Destructor); 13598 } 13599} 13600 13601void Sema::CheckCompleteDestructorVariant(SourceLocation CurrentLocation, 13602 CXXDestructorDecl *Destructor) { 13603 if (Destructor->isInvalidDecl()) 13604 return; 13605 13606 CXXRecordDecl *ClassDecl = Destructor->getParent(); 13607 assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&((void)0) 13608 "implicit complete dtors unneeded outside MS ABI")((void)0); 13609 assert(ClassDecl->getNumVBases() > 0 &&((void)0) 13610 "complete dtor only exists for classes with vbases")((void)0); 13611 13612 SynthesizedFunctionScope Scope(*this, Destructor); 13613 13614 // Add a context note for diagnostics produced after this point. 13615 Scope.addContextNote(CurrentLocation); 13616 13617 MarkVirtualBaseDestructorsReferenced(Destructor->getLocation(), ClassDecl); 13618} 13619 13620/// Perform any semantic analysis which needs to be delayed until all 13621/// pending class member declarations have been parsed. 13622void Sema::ActOnFinishCXXMemberDecls() { 13623 // If the context is an invalid C++ class, just suppress these checks. 13624 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) { 13625 if (Record->isInvalidDecl()) { 13626 DelayedOverridingExceptionSpecChecks.clear(); 13627 DelayedEquivalentExceptionSpecChecks.clear(); 13628 return; 13629 } 13630 checkForMultipleExportedDefaultConstructors(*this, Record); 13631 } 13632} 13633 13634void Sema::ActOnFinishCXXNonNestedClass() { 13635 referenceDLLExportedClassMethods(); 13636 13637 if (!DelayedDllExportMemberFunctions.empty()) { 13638 SmallVector<CXXMethodDecl*, 4> WorkList; 13639 std::swap(DelayedDllExportMemberFunctions, WorkList); 13640 for (CXXMethodDecl *M : WorkList) { 13641 DefineDefaultedFunction(*this, M, M->getLocation()); 13642 13643 // Pass the method to the consumer to get emitted. This is not necessary 13644 // for explicit instantiation definitions, as they will get emitted 13645 // anyway. 13646 if (M->getParent()->getTemplateSpecializationKind() != 13647 TSK_ExplicitInstantiationDefinition) 13648 ActOnFinishInlineFunctionDef(M); 13649 } 13650 } 13651} 13652 13653void Sema::referenceDLLExportedClassMethods() { 13654 if (!DelayedDllExportClasses.empty()) { 13655 // Calling ReferenceDllExportedMembers might cause the current function to 13656 // be called again, so use a local copy of DelayedDllExportClasses. 13657 SmallVector<CXXRecordDecl *, 4> WorkList; 13658 std::swap(DelayedDllExportClasses, WorkList); 13659 for (CXXRecordDecl *Class : WorkList) 13660 ReferenceDllExportedMembers(*this, Class); 13661 } 13662} 13663 13664void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) { 13665 assert(getLangOpts().CPlusPlus11 &&((void)0) 13666 "adjusting dtor exception specs was introduced in c++11")((void)0); 13667 13668 if (Destructor->isDependentContext()) 13669 return; 13670 13671 // C++11 [class.dtor]p3: 13672 // A declaration of a destructor that does not have an exception- 13673 // specification is implicitly considered to have the same exception- 13674 // specification as an implicit declaration. 13675 const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>(); 13676 if (DtorType->hasExceptionSpec()) 13677 return; 13678 13679 // Replace the destructor's type, building off the existing one. Fortunately, 13680 // the only thing of interest in the destructor type is its extended info. 13681 // The return and arguments are fixed. 13682 FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo(); 13683 EPI.ExceptionSpec.Type = EST_Unevaluated; 13684 EPI.ExceptionSpec.SourceDecl = Destructor; 13685 Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI)); 13686 13687 // FIXME: If the destructor has a body that could throw, and the newly created 13688 // spec doesn't allow exceptions, we should emit a warning, because this 13689 // change in behavior can break conforming C++03 programs at runtime. 13690 // However, we don't have a body or an exception specification yet, so it 13691 // needs to be done somewhere else. 13692} 13693 13694namespace { 13695/// An abstract base class for all helper classes used in building the 13696// copy/move operators. These classes serve as factory functions and help us 13697// avoid using the same Expr* in the AST twice. 13698class ExprBuilder { 13699 ExprBuilder(const ExprBuilder&) = delete; 13700 ExprBuilder &operator=(const ExprBuilder&) = delete; 13701 13702protected: 13703 static Expr *assertNotNull(Expr *E) { 13704 assert(E && "Expression construction must not fail.")((void)0); 13705 return E; 13706 } 13707 13708public: 13709 ExprBuilder() {} 13710 virtual ~ExprBuilder() {} 13711 13712 virtual Expr *build(Sema &S, SourceLocation Loc) const = 0; 13713}; 13714 13715class RefBuilder: public ExprBuilder { 13716 VarDecl *Var; 13717 QualType VarType; 13718 13719public: 13720 Expr *build(Sema &S, SourceLocation Loc) const override { 13721 return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc)); 13722 } 13723 13724 RefBuilder(VarDecl *Var, QualType VarType) 13725 : Var(Var), VarType(VarType) {} 13726}; 13727 13728class ThisBuilder: public ExprBuilder { 13729public: 13730 Expr *build(Sema &S, SourceLocation Loc) const override { 13731 return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>()); 13732 } 13733}; 13734 13735class CastBuilder: public ExprBuilder { 13736 const ExprBuilder &Builder; 13737 QualType Type; 13738 ExprValueKind Kind; 13739 const CXXCastPath &Path; 13740 13741public: 13742 Expr *build(Sema &S, SourceLocation Loc) const override { 13743 return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type, 13744 CK_UncheckedDerivedToBase, Kind, 13745 &Path).get()); 13746 } 13747 13748 CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind, 13749 const CXXCastPath &Path) 13750 : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {} 13751}; 13752 13753class DerefBuilder: public ExprBuilder { 13754 const ExprBuilder &Builder; 13755 13756public: 13757 Expr *build(Sema &S, SourceLocation Loc) const override { 13758 return assertNotNull( 13759 S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get()); 13760 } 13761 13762 DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {} 13763}; 13764 13765class MemberBuilder: public ExprBuilder { 13766 const ExprBuilder &Builder; 13767 QualType Type; 13768 CXXScopeSpec SS; 13769 bool IsArrow; 13770 LookupResult &MemberLookup; 13771 13772public: 13773 Expr *build(Sema &S, SourceLocation Loc) const override { 13774 return assertNotNull(S.BuildMemberReferenceExpr( 13775 Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(), 13776 nullptr, MemberLookup, nullptr, nullptr).get()); 13777 } 13778 13779 MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow, 13780 LookupResult &MemberLookup) 13781 : Builder(Builder), Type(Type), IsArrow(IsArrow), 13782 MemberLookup(MemberLookup) {} 13783}; 13784 13785class MoveCastBuilder: public ExprBuilder { 13786 const ExprBuilder &Builder; 13787 13788public: 13789 Expr *build(Sema &S, SourceLocation Loc) const override { 13790 return assertNotNull(CastForMoving(S, Builder.build(S, Loc))); 13791 } 13792 13793 MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {} 13794}; 13795 13796class LvalueConvBuilder: public ExprBuilder { 13797 const ExprBuilder &Builder; 13798 13799public: 13800 Expr *build(Sema &S, SourceLocation Loc) const override { 13801 return assertNotNull( 13802 S.DefaultLvalueConversion(Builder.build(S, Loc)).get()); 13803 } 13804 13805 LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {} 13806}; 13807 13808class SubscriptBuilder: public ExprBuilder { 13809 const ExprBuilder &Base; 13810 const ExprBuilder &Index; 13811 13812public: 13813 Expr *build(Sema &S, SourceLocation Loc) const override { 13814 return assertNotNull(S.CreateBuiltinArraySubscriptExpr( 13815 Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get()); 13816 } 13817 13818 SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index) 13819 : Base(Base), Index(Index) {} 13820}; 13821 13822} // end anonymous namespace 13823 13824/// When generating a defaulted copy or move assignment operator, if a field 13825/// should be copied with __builtin_memcpy rather than via explicit assignments, 13826/// do so. This optimization only applies for arrays of scalars, and for arrays 13827/// of class type where the selected copy/move-assignment operator is trivial. 13828static StmtResult 13829buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T, 13830 const ExprBuilder &ToB, const ExprBuilder &FromB) { 13831 // Compute the size of the memory buffer to be copied. 13832 QualType SizeType = S.Context.getSizeType(); 13833 llvm::APInt Size(S.Context.getTypeSize(SizeType), 13834 S.Context.getTypeSizeInChars(T).getQuantity()); 13835 13836 // Take the address of the field references for "from" and "to". We 13837 // directly construct UnaryOperators here because semantic analysis 13838 // does not permit us to take the address of an xvalue. 13839 Expr *From = FromB.build(S, Loc); 13840 From = UnaryOperator::Create( 13841 S.Context, From, UO_AddrOf, S.Context.getPointerType(From->getType()), 13842 VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides()); 13843 Expr *To = ToB.build(S, Loc); 13844 To = UnaryOperator::Create( 13845 S.Context, To, UO_AddrOf, S.Context.getPointerType(To->getType()), 13846 VK_PRValue, OK_Ordinary, Loc, false, S.CurFPFeatureOverrides()); 13847 13848 const Type *E = T->getBaseElementTypeUnsafe(); 13849 bool NeedsCollectableMemCpy = 13850 E->isRecordType() && 13851 E->castAs<RecordType>()->getDecl()->hasObjectMember(); 13852 13853 // Create a reference to the __builtin_objc_memmove_collectable function 13854 StringRef MemCpyName = NeedsCollectableMemCpy ? 13855 "__builtin_objc_memmove_collectable" : 13856 "__builtin_memcpy"; 13857 LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc, 13858 Sema::LookupOrdinaryName); 13859 S.LookupName(R, S.TUScope, true); 13860 13861 FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>(); 13862 if (!MemCpy) 13863 // Something went horribly wrong earlier, and we will have complained 13864 // about it. 13865 return StmtError(); 13866 13867 ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy, 13868 VK_PRValue, Loc, nullptr); 13869 assert(MemCpyRef.isUsable() && "Builtin reference cannot fail")((void)0); 13870 13871 Expr *CallArgs[] = { 13872 To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc) 13873 }; 13874 ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(), 13875 Loc, CallArgs, Loc); 13876 13877 assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!")((void)0); 13878 return Call.getAs<Stmt>(); 13879} 13880 13881/// Builds a statement that copies/moves the given entity from \p From to 13882/// \c To. 13883/// 13884/// This routine is used to copy/move the members of a class with an 13885/// implicitly-declared copy/move assignment operator. When the entities being 13886/// copied are arrays, this routine builds for loops to copy them. 13887/// 13888/// \param S The Sema object used for type-checking. 13889/// 13890/// \param Loc The location where the implicit copy/move is being generated. 13891/// 13892/// \param T The type of the expressions being copied/moved. Both expressions 13893/// must have this type. 13894/// 13895/// \param To The expression we are copying/moving to. 13896/// 13897/// \param From The expression we are copying/moving from. 13898/// 13899/// \param CopyingBaseSubobject Whether we're copying/moving a base subobject. 13900/// Otherwise, it's a non-static member subobject. 13901/// 13902/// \param Copying Whether we're copying or moving. 13903/// 13904/// \param Depth Internal parameter recording the depth of the recursion. 13905/// 13906/// \returns A statement or a loop that copies the expressions, or StmtResult(0) 13907/// if a memcpy should be used instead. 13908static StmtResult 13909buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T, 13910 const ExprBuilder &To, const ExprBuilder &From, 13911 bool CopyingBaseSubobject, bool Copying, 13912 unsigned Depth = 0) { 13913 // C++11 [class.copy]p28: 13914 // Each subobject is assigned in the manner appropriate to its type: 13915 // 13916 // - if the subobject is of class type, as if by a call to operator= with 13917 // the subobject as the object expression and the corresponding 13918 // subobject of x as a single function argument (as if by explicit 13919 // qualification; that is, ignoring any possible virtual overriding 13920 // functions in more derived classes); 13921 // 13922 // C++03 [class.copy]p13: 13923 // - if the subobject is of class type, the copy assignment operator for 13924 // the class is used (as if by explicit qualification; that is, 13925 // ignoring any possible virtual overriding functions in more derived 13926 // classes); 13927 if (const RecordType *RecordTy = T->getAs<RecordType>()) { 13928 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl()); 13929 13930 // Look for operator=. 13931 DeclarationName Name 13932 = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal); 13933 LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName); 13934 S.LookupQualifiedName(OpLookup, ClassDecl, false); 13935 13936 // Prior to C++11, filter out any result that isn't a copy/move-assignment 13937 // operator. 13938 if (!S.getLangOpts().CPlusPlus11) { 13939 LookupResult::Filter F = OpLookup.makeFilter(); 13940 while (F.hasNext()) { 13941 NamedDecl *D = F.next(); 13942 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) 13943 if (Method->isCopyAssignmentOperator() || 13944 (!Copying && Method->isMoveAssignmentOperator())) 13945 continue; 13946 13947 F.erase(); 13948 } 13949 F.done(); 13950 } 13951 13952 // Suppress the protected check (C++ [class.protected]) for each of the 13953 // assignment operators we found. This strange dance is required when 13954 // we're assigning via a base classes's copy-assignment operator. To 13955 // ensure that we're getting the right base class subobject (without 13956 // ambiguities), we need to cast "this" to that subobject type; to 13957 // ensure that we don't go through the virtual call mechanism, we need 13958 // to qualify the operator= name with the base class (see below). However, 13959 // this means that if the base class has a protected copy assignment 13960 // operator, the protected member access check will fail. So, we 13961 // rewrite "protected" access to "public" access in this case, since we 13962 // know by construction that we're calling from a derived class. 13963 if (CopyingBaseSubobject) { 13964 for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end(); 13965 L != LEnd; ++L) { 13966 if (L.getAccess() == AS_protected) 13967 L.setAccess(AS_public); 13968 } 13969 } 13970 13971 // Create the nested-name-specifier that will be used to qualify the 13972 // reference to operator=; this is required to suppress the virtual 13973 // call mechanism. 13974 CXXScopeSpec SS; 13975 const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr()); 13976 SS.MakeTrivial(S.Context, 13977 NestedNameSpecifier::Create(S.Context, nullptr, false, 13978 CanonicalT), 13979 Loc); 13980 13981 // Create the reference to operator=. 13982 ExprResult OpEqualRef 13983 = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false, 13984 SS, /*TemplateKWLoc=*/SourceLocation(), 13985 /*FirstQualifierInScope=*/nullptr, 13986 OpLookup, 13987 /*TemplateArgs=*/nullptr, /*S*/nullptr, 13988 /*SuppressQualifierCheck=*/true); 13989 if (OpEqualRef.isInvalid()) 13990 return StmtError(); 13991 13992 // Build the call to the assignment operator. 13993 13994 Expr *FromInst = From.build(S, Loc); 13995 ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr, 13996 OpEqualRef.getAs<Expr>(), 13997 Loc, FromInst, Loc); 13998 if (Call.isInvalid()) 13999 return StmtError(); 14000 14001 // If we built a call to a trivial 'operator=' while copying an array, 14002 // bail out. We'll replace the whole shebang with a memcpy. 14003 CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get()); 14004 if (CE && CE->getMethodDecl()->isTrivial() && Depth) 14005 return StmtResult((Stmt*)nullptr); 14006 14007 // Convert to an expression-statement, and clean up any produced 14008 // temporaries. 14009 return S.ActOnExprStmt(Call); 14010 } 14011 14012 // - if the subobject is of scalar type, the built-in assignment 14013 // operator is used. 14014 const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T); 14015 if (!ArrayTy) { 14016 ExprResult Assignment = S.CreateBuiltinBinOp( 14017 Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc)); 14018 if (Assignment.isInvalid()) 14019 return StmtError(); 14020 return S.ActOnExprStmt(Assignment); 14021 } 14022 14023 // - if the subobject is an array, each element is assigned, in the 14024 // manner appropriate to the element type; 14025 14026 // Construct a loop over the array bounds, e.g., 14027 // 14028 // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0) 14029 // 14030 // that will copy each of the array elements. 14031 QualType SizeType = S.Context.getSizeType(); 14032 14033 // Create the iteration variable. 14034 IdentifierInfo *IterationVarName = nullptr; 14035 { 14036 SmallString<8> Str; 14037 llvm::raw_svector_ostream OS(Str); 14038 OS << "__i" << Depth; 14039 IterationVarName = &S.Context.Idents.get(OS.str()); 14040 } 14041 VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, 14042 IterationVarName, SizeType, 14043 S.Context.getTrivialTypeSourceInfo(SizeType, Loc), 14044 SC_None); 14045 14046 // Initialize the iteration variable to zero. 14047 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0); 14048 IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc)); 14049 14050 // Creates a reference to the iteration variable. 14051 RefBuilder IterationVarRef(IterationVar, SizeType); 14052 LvalueConvBuilder IterationVarRefRVal(IterationVarRef); 14053 14054 // Create the DeclStmt that holds the iteration variable. 14055 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc); 14056 14057 // Subscript the "from" and "to" expressions with the iteration variable. 14058 SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal); 14059 MoveCastBuilder FromIndexMove(FromIndexCopy); 14060 const ExprBuilder *FromIndex; 14061 if (Copying) 14062 FromIndex = &FromIndexCopy; 14063 else 14064 FromIndex = &FromIndexMove; 14065 14066 SubscriptBuilder ToIndex(To, IterationVarRefRVal); 14067 14068 // Build the copy/move for an individual element of the array. 14069 StmtResult Copy = 14070 buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(), 14071 ToIndex, *FromIndex, CopyingBaseSubobject, 14072 Copying, Depth + 1); 14073 // Bail out if copying fails or if we determined that we should use memcpy. 14074 if (Copy.isInvalid() || !Copy.get()) 14075 return Copy; 14076 14077 // Create the comparison against the array bound. 14078 llvm::APInt Upper 14079 = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType)); 14080 Expr *Comparison = BinaryOperator::Create( 14081 S.Context, IterationVarRefRVal.build(S, Loc), 14082 IntegerLiteral::Create(S.Context, Upper, SizeType, Loc), BO_NE, 14083 S.Context.BoolTy, VK_PRValue, OK_Ordinary, Loc, 14084 S.CurFPFeatureOverrides()); 14085 14086 // Create the pre-increment of the iteration variable. We can determine 14087 // whether the increment will overflow based on the value of the array 14088 // bound. 14089 Expr *Increment = UnaryOperator::Create( 14090 S.Context, IterationVarRef.build(S, Loc), UO_PreInc, SizeType, VK_LValue, 14091 OK_Ordinary, Loc, Upper.isMaxValue(), S.CurFPFeatureOverrides()); 14092 14093 // Construct the loop that copies all elements of this array. 14094 return S.ActOnForStmt( 14095 Loc, Loc, InitStmt, 14096 S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean), 14097 S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get()); 14098} 14099 14100static StmtResult 14101buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T, 14102 const ExprBuilder &To, const ExprBuilder &From, 14103 bool CopyingBaseSubobject, bool Copying) { 14104 // Maybe we should use a memcpy? 14105 if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() && 14106 T.isTriviallyCopyableType(S.Context)) 14107 return buildMemcpyForAssignmentOp(S, Loc, T, To, From); 14108 14109 StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From, 14110 CopyingBaseSubobject, 14111 Copying, 0)); 14112 14113 // If we ended up picking a trivial assignment operator for an array of a 14114 // non-trivially-copyable class type, just emit a memcpy. 14115 if (!Result.isInvalid() && !Result.get()) 14116 return buildMemcpyForAssignmentOp(S, Loc, T, To, From); 14117 14118 return Result; 14119} 14120 14121CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) { 14122 // Note: The following rules are largely analoguous to the copy 14123 // constructor rules. Note that virtual bases are not taken into account 14124 // for determining the argument type of the operator. Note also that 14125 // operators taking an object instead of a reference are allowed. 14126 assert(ClassDecl->needsImplicitCopyAssignment())((void)0); 14127 14128 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment); 14129 if (DSM.isAlreadyBeingDeclared()) 14130 return nullptr; 14131 14132 QualType ArgType = Context.getTypeDeclType(ClassDecl); 14133 LangAS AS = getDefaultCXXMethodAddrSpace(); 14134 if (AS != LangAS::Default) 14135 ArgType = Context.getAddrSpaceQualType(ArgType, AS); 14136 QualType RetType = Context.getLValueReferenceType(ArgType); 14137 bool Const = ClassDecl->implicitCopyAssignmentHasConstParam(); 14138 if (Const) 14139 ArgType = ArgType.withConst(); 14140 14141 ArgType = Context.getLValueReferenceType(ArgType); 14142 14143 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 14144 CXXCopyAssignment, 14145 Const); 14146 14147 // An implicitly-declared copy assignment operator is an inline public 14148 // member of its class. 14149 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 14150 SourceLocation ClassLoc = ClassDecl->getLocation(); 14151 DeclarationNameInfo NameInfo(Name, ClassLoc); 14152 CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create( 14153 Context, ClassDecl, ClassLoc, NameInfo, QualType(), 14154 /*TInfo=*/nullptr, /*StorageClass=*/SC_None, 14155 /*isInline=*/true, 14156 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified, 14157 SourceLocation()); 14158 CopyAssignment->setAccess(AS_public); 14159 CopyAssignment->setDefaulted(); 14160 CopyAssignment->setImplicit(); 14161 14162 if (getLangOpts().CUDA) { 14163 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment, 14164 CopyAssignment, 14165 /* ConstRHS */ Const, 14166 /* Diagnose */ false); 14167 } 14168 14169 setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType); 14170 14171 // Add the parameter to the operator. 14172 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment, 14173 ClassLoc, ClassLoc, 14174 /*Id=*/nullptr, ArgType, 14175 /*TInfo=*/nullptr, SC_None, 14176 nullptr); 14177 CopyAssignment->setParams(FromParam); 14178 14179 CopyAssignment->setTrivial( 14180 ClassDecl->needsOverloadResolutionForCopyAssignment() 14181 ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment) 14182 : ClassDecl->hasTrivialCopyAssignment()); 14183 14184 // Note that we have added this copy-assignment operator. 14185 ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared; 14186 14187 Scope *S = getScopeForContext(ClassDecl); 14188 CheckImplicitSpecialMemberDeclaration(S, CopyAssignment); 14189 14190 if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment)) { 14191 ClassDecl->setImplicitCopyAssignmentIsDeleted(); 14192 SetDeclDeleted(CopyAssignment, ClassLoc); 14193 } 14194 14195 if (S) 14196 PushOnScopeChains(CopyAssignment, S, false); 14197 ClassDecl->addDecl(CopyAssignment); 14198 14199 return CopyAssignment; 14200} 14201 14202/// Diagnose an implicit copy operation for a class which is odr-used, but 14203/// which is deprecated because the class has a user-declared copy constructor, 14204/// copy assignment operator, or destructor. 14205static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) { 14206 assert(CopyOp->isImplicit())((void)0); 14207 14208 CXXRecordDecl *RD = CopyOp->getParent(); 14209 CXXMethodDecl *UserDeclaredOperation = nullptr; 14210 14211 // In Microsoft mode, assignment operations don't affect constructors and 14212 // vice versa. 14213 if (RD->hasUserDeclaredDestructor()) { 14214 UserDeclaredOperation = RD->getDestructor(); 14215 } else if (!isa<CXXConstructorDecl>(CopyOp) && 14216 RD->hasUserDeclaredCopyConstructor() && 14217 !S.getLangOpts().MSVCCompat) { 14218 // Find any user-declared copy constructor. 14219 for (auto *I : RD->ctors()) { 14220 if (I->isCopyConstructor()) { 14221 UserDeclaredOperation = I; 14222 break; 14223 } 14224 } 14225 assert(UserDeclaredOperation)((void)0); 14226 } else if (isa<CXXConstructorDecl>(CopyOp) && 14227 RD->hasUserDeclaredCopyAssignment() && 14228 !S.getLangOpts().MSVCCompat) { 14229 // Find any user-declared move assignment operator. 14230 for (auto *I : RD->methods()) { 14231 if (I->isCopyAssignmentOperator()) { 14232 UserDeclaredOperation = I; 14233 break; 14234 } 14235 } 14236 assert(UserDeclaredOperation)((void)0); 14237 } 14238 14239 if (UserDeclaredOperation) { 14240 bool UDOIsUserProvided = UserDeclaredOperation->isUserProvided(); 14241 bool UDOIsDestructor = isa<CXXDestructorDecl>(UserDeclaredOperation); 14242 bool IsCopyAssignment = !isa<CXXConstructorDecl>(CopyOp); 14243 unsigned DiagID = 14244 (UDOIsUserProvided && UDOIsDestructor) 14245 ? diag::warn_deprecated_copy_with_user_provided_dtor 14246 : (UDOIsUserProvided && !UDOIsDestructor) 14247 ? diag::warn_deprecated_copy_with_user_provided_copy 14248 : (!UDOIsUserProvided && UDOIsDestructor) 14249 ? diag::warn_deprecated_copy_with_dtor 14250 : diag::warn_deprecated_copy; 14251 S.Diag(UserDeclaredOperation->getLocation(), DiagID) 14252 << RD << IsCopyAssignment; 14253 } 14254} 14255 14256void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation, 14257 CXXMethodDecl *CopyAssignOperator) { 14258 assert((CopyAssignOperator->isDefaulted() &&((void)0) 14259 CopyAssignOperator->isOverloadedOperator() &&((void)0) 14260 CopyAssignOperator->getOverloadedOperator() == OO_Equal &&((void)0) 14261 !CopyAssignOperator->doesThisDeclarationHaveABody() &&((void)0) 14262 !CopyAssignOperator->isDeleted()) &&((void)0) 14263 "DefineImplicitCopyAssignment called for wrong function")((void)0); 14264 if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl()) 14265 return; 14266 14267 CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent(); 14268 if (ClassDecl->isInvalidDecl()) { 14269 CopyAssignOperator->setInvalidDecl(); 14270 return; 14271 } 14272 14273 SynthesizedFunctionScope Scope(*this, CopyAssignOperator); 14274 14275 // The exception specification is needed because we are defining the 14276 // function. 14277 ResolveExceptionSpec(CurrentLocation, 14278 CopyAssignOperator->getType()->castAs<FunctionProtoType>()); 14279 14280 // Add a context note for diagnostics produced after this point. 14281 Scope.addContextNote(CurrentLocation); 14282 14283 // C++11 [class.copy]p18: 14284 // The [definition of an implicitly declared copy assignment operator] is 14285 // deprecated if the class has a user-declared copy constructor or a 14286 // user-declared destructor. 14287 if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit()) 14288 diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator); 14289 14290 // C++0x [class.copy]p30: 14291 // The implicitly-defined or explicitly-defaulted copy assignment operator 14292 // for a non-union class X performs memberwise copy assignment of its 14293 // subobjects. The direct base classes of X are assigned first, in the 14294 // order of their declaration in the base-specifier-list, and then the 14295 // immediate non-static data members of X are assigned, in the order in 14296 // which they were declared in the class definition. 14297 14298 // The statements that form the synthesized function body. 14299 SmallVector<Stmt*, 8> Statements; 14300 14301 // The parameter for the "other" object, which we are copying from. 14302 ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0); 14303 Qualifiers OtherQuals = Other->getType().getQualifiers(); 14304 QualType OtherRefType = Other->getType(); 14305 if (const LValueReferenceType *OtherRef 14306 = OtherRefType->getAs<LValueReferenceType>()) { 14307 OtherRefType = OtherRef->getPointeeType(); 14308 OtherQuals = OtherRefType.getQualifiers(); 14309 } 14310 14311 // Our location for everything implicitly-generated. 14312 SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid() 14313 ? CopyAssignOperator->getEndLoc() 14314 : CopyAssignOperator->getLocation(); 14315 14316 // Builds a DeclRefExpr for the "other" object. 14317 RefBuilder OtherRef(Other, OtherRefType); 14318 14319 // Builds the "this" pointer. 14320 ThisBuilder This; 14321 14322 // Assign base classes. 14323 bool Invalid = false; 14324 for (auto &Base : ClassDecl->bases()) { 14325 // Form the assignment: 14326 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other)); 14327 QualType BaseType = Base.getType().getUnqualifiedType(); 14328 if (!BaseType->isRecordType()) { 14329 Invalid = true; 14330 continue; 14331 } 14332 14333 CXXCastPath BasePath; 14334 BasePath.push_back(&Base); 14335 14336 // Construct the "from" expression, which is an implicit cast to the 14337 // appropriately-qualified base type. 14338 CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals), 14339 VK_LValue, BasePath); 14340 14341 // Dereference "this". 14342 DerefBuilder DerefThis(This); 14343 CastBuilder To(DerefThis, 14344 Context.getQualifiedType( 14345 BaseType, CopyAssignOperator->getMethodQualifiers()), 14346 VK_LValue, BasePath); 14347 14348 // Build the copy. 14349 StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType, 14350 To, From, 14351 /*CopyingBaseSubobject=*/true, 14352 /*Copying=*/true); 14353 if (Copy.isInvalid()) { 14354 CopyAssignOperator->setInvalidDecl(); 14355 return; 14356 } 14357 14358 // Success! Record the copy. 14359 Statements.push_back(Copy.getAs<Expr>()); 14360 } 14361 14362 // Assign non-static members. 14363 for (auto *Field : ClassDecl->fields()) { 14364 // FIXME: We should form some kind of AST representation for the implied 14365 // memcpy in a union copy operation. 14366 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) 14367 continue; 14368 14369 if (Field->isInvalidDecl()) { 14370 Invalid = true; 14371 continue; 14372 } 14373 14374 // Check for members of reference type; we can't copy those. 14375 if (Field->getType()->isReferenceType()) { 14376 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) 14377 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); 14378 Diag(Field->getLocation(), diag::note_declared_at); 14379 Invalid = true; 14380 continue; 14381 } 14382 14383 // Check for members of const-qualified, non-class type. 14384 QualType BaseType = Context.getBaseElementType(Field->getType()); 14385 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) { 14386 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) 14387 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); 14388 Diag(Field->getLocation(), diag::note_declared_at); 14389 Invalid = true; 14390 continue; 14391 } 14392 14393 // Suppress assigning zero-width bitfields. 14394 if (Field->isZeroLengthBitField(Context)) 14395 continue; 14396 14397 QualType FieldType = Field->getType().getNonReferenceType(); 14398 if (FieldType->isIncompleteArrayType()) { 14399 assert(ClassDecl->hasFlexibleArrayMember() &&((void)0) 14400 "Incomplete array type is not valid")((void)0); 14401 continue; 14402 } 14403 14404 // Build references to the field in the object we're copying from and to. 14405 CXXScopeSpec SS; // Intentionally empty 14406 LookupResult MemberLookup(*this, Field->getDeclName(), Loc, 14407 LookupMemberName); 14408 MemberLookup.addDecl(Field); 14409 MemberLookup.resolveKind(); 14410 14411 MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup); 14412 14413 MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup); 14414 14415 // Build the copy of this field. 14416 StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType, 14417 To, From, 14418 /*CopyingBaseSubobject=*/false, 14419 /*Copying=*/true); 14420 if (Copy.isInvalid()) { 14421 CopyAssignOperator->setInvalidDecl(); 14422 return; 14423 } 14424 14425 // Success! Record the copy. 14426 Statements.push_back(Copy.getAs<Stmt>()); 14427 } 14428 14429 if (!Invalid) { 14430 // Add a "return *this;" 14431 ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); 14432 14433 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get()); 14434 if (Return.isInvalid()) 14435 Invalid = true; 14436 else 14437 Statements.push_back(Return.getAs<Stmt>()); 14438 } 14439 14440 if (Invalid) { 14441 CopyAssignOperator->setInvalidDecl(); 14442 return; 14443 } 14444 14445 StmtResult Body; 14446 { 14447 CompoundScopeRAII CompoundScope(*this); 14448 Body = ActOnCompoundStmt(Loc, Loc, Statements, 14449 /*isStmtExpr=*/false); 14450 assert(!Body.isInvalid() && "Compound statement creation cannot fail")((void)0); 14451 } 14452 CopyAssignOperator->setBody(Body.getAs<Stmt>()); 14453 CopyAssignOperator->markUsed(Context); 14454 14455 if (ASTMutationListener *L = getASTMutationListener()) { 14456 L->CompletedImplicitDefinition(CopyAssignOperator); 14457 } 14458} 14459 14460CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) { 14461 assert(ClassDecl->needsImplicitMoveAssignment())((void)0); 14462 14463 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment); 14464 if (DSM.isAlreadyBeingDeclared()) 14465 return nullptr; 14466 14467 // Note: The following rules are largely analoguous to the move 14468 // constructor rules. 14469 14470 QualType ArgType = Context.getTypeDeclType(ClassDecl); 14471 LangAS AS = getDefaultCXXMethodAddrSpace(); 14472 if (AS != LangAS::Default) 14473 ArgType = Context.getAddrSpaceQualType(ArgType, AS); 14474 QualType RetType = Context.getLValueReferenceType(ArgType); 14475 ArgType = Context.getRValueReferenceType(ArgType); 14476 14477 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 14478 CXXMoveAssignment, 14479 false); 14480 14481 // An implicitly-declared move assignment operator is an inline public 14482 // member of its class. 14483 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal); 14484 SourceLocation ClassLoc = ClassDecl->getLocation(); 14485 DeclarationNameInfo NameInfo(Name, ClassLoc); 14486 CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create( 14487 Context, ClassDecl, ClassLoc, NameInfo, QualType(), 14488 /*TInfo=*/nullptr, /*StorageClass=*/SC_None, 14489 /*isInline=*/true, 14490 Constexpr ? ConstexprSpecKind::Constexpr : ConstexprSpecKind::Unspecified, 14491 SourceLocation()); 14492 MoveAssignment->setAccess(AS_public); 14493 MoveAssignment->setDefaulted(); 14494 MoveAssignment->setImplicit(); 14495 14496 if (getLangOpts().CUDA) { 14497 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment, 14498 MoveAssignment, 14499 /* ConstRHS */ false, 14500 /* Diagnose */ false); 14501 } 14502 14503 setupImplicitSpecialMemberType(MoveAssignment, RetType, ArgType); 14504 14505 // Add the parameter to the operator. 14506 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment, 14507 ClassLoc, ClassLoc, 14508 /*Id=*/nullptr, ArgType, 14509 /*TInfo=*/nullptr, SC_None, 14510 nullptr); 14511 MoveAssignment->setParams(FromParam); 14512 14513 MoveAssignment->setTrivial( 14514 ClassDecl->needsOverloadResolutionForMoveAssignment() 14515 ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment) 14516 : ClassDecl->hasTrivialMoveAssignment()); 14517 14518 // Note that we have added this copy-assignment operator. 14519 ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared; 14520 14521 Scope *S = getScopeForContext(ClassDecl); 14522 CheckImplicitSpecialMemberDeclaration(S, MoveAssignment); 14523 14524 if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) { 14525 ClassDecl->setImplicitMoveAssignmentIsDeleted(); 14526 SetDeclDeleted(MoveAssignment, ClassLoc); 14527 } 14528 14529 if (S) 14530 PushOnScopeChains(MoveAssignment, S, false); 14531 ClassDecl->addDecl(MoveAssignment); 14532 14533 return MoveAssignment; 14534} 14535 14536/// Check if we're implicitly defining a move assignment operator for a class 14537/// with virtual bases. Such a move assignment might move-assign the virtual 14538/// base multiple times. 14539static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class, 14540 SourceLocation CurrentLocation) { 14541 assert(!Class->isDependentContext() && "should not define dependent move")((void)0); 14542 14543 // Only a virtual base could get implicitly move-assigned multiple times. 14544 // Only a non-trivial move assignment can observe this. We only want to 14545 // diagnose if we implicitly define an assignment operator that assigns 14546 // two base classes, both of which move-assign the same virtual base. 14547 if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() || 14548 Class->getNumBases() < 2) 14549 return; 14550 14551 llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist; 14552 typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap; 14553 VBaseMap VBases; 14554 14555 for (auto &BI : Class->bases()) { 14556 Worklist.push_back(&BI); 14557 while (!Worklist.empty()) { 14558 CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val(); 14559 CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl(); 14560 14561 // If the base has no non-trivial move assignment operators, 14562 // we don't care about moves from it. 14563 if (!Base->hasNonTrivialMoveAssignment()) 14564 continue; 14565 14566 // If there's nothing virtual here, skip it. 14567 if (!BaseSpec->isVirtual() && !Base->getNumVBases()) 14568 continue; 14569 14570 // If we're not actually going to call a move assignment for this base, 14571 // or the selected move assignment is trivial, skip it. 14572 Sema::SpecialMemberOverloadResult SMOR = 14573 S.LookupSpecialMember(Base, Sema::CXXMoveAssignment, 14574 /*ConstArg*/false, /*VolatileArg*/false, 14575 /*RValueThis*/true, /*ConstThis*/false, 14576 /*VolatileThis*/false); 14577 if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() || 14578 !SMOR.getMethod()->isMoveAssignmentOperator()) 14579 continue; 14580 14581 if (BaseSpec->isVirtual()) { 14582 // We're going to move-assign this virtual base, and its move 14583 // assignment operator is not trivial. If this can happen for 14584 // multiple distinct direct bases of Class, diagnose it. (If it 14585 // only happens in one base, we'll diagnose it when synthesizing 14586 // that base class's move assignment operator.) 14587 CXXBaseSpecifier *&Existing = 14588 VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI)) 14589 .first->second; 14590 if (Existing && Existing != &BI) { 14591 S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times) 14592 << Class << Base; 14593 S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here) 14594 << (Base->getCanonicalDecl() == 14595 Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl()) 14596 << Base << Existing->getType() << Existing->getSourceRange(); 14597 S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here) 14598 << (Base->getCanonicalDecl() == 14599 BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl()) 14600 << Base << BI.getType() << BaseSpec->getSourceRange(); 14601 14602 // Only diagnose each vbase once. 14603 Existing = nullptr; 14604 } 14605 } else { 14606 // Only walk over bases that have defaulted move assignment operators. 14607 // We assume that any user-provided move assignment operator handles 14608 // the multiple-moves-of-vbase case itself somehow. 14609 if (!SMOR.getMethod()->isDefaulted()) 14610 continue; 14611 14612 // We're going to move the base classes of Base. Add them to the list. 14613 for (auto &BI : Base->bases()) 14614 Worklist.push_back(&BI); 14615 } 14616 } 14617 } 14618} 14619 14620void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation, 14621 CXXMethodDecl *MoveAssignOperator) { 14622 assert((MoveAssignOperator->isDefaulted() &&((void)0) 14623 MoveAssignOperator->isOverloadedOperator() &&((void)0) 14624 MoveAssignOperator->getOverloadedOperator() == OO_Equal &&((void)0) 14625 !MoveAssignOperator->doesThisDeclarationHaveABody() &&((void)0) 14626 !MoveAssignOperator->isDeleted()) &&((void)0) 14627 "DefineImplicitMoveAssignment called for wrong function")((void)0); 14628 if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl()) 14629 return; 14630 14631 CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent(); 14632 if (ClassDecl->isInvalidDecl()) { 14633 MoveAssignOperator->setInvalidDecl(); 14634 return; 14635 } 14636 14637 // C++0x [class.copy]p28: 14638 // The implicitly-defined or move assignment operator for a non-union class 14639 // X performs memberwise move assignment of its subobjects. The direct base 14640 // classes of X are assigned first, in the order of their declaration in the 14641 // base-specifier-list, and then the immediate non-static data members of X 14642 // are assigned, in the order in which they were declared in the class 14643 // definition. 14644 14645 // Issue a warning if our implicit move assignment operator will move 14646 // from a virtual base more than once. 14647 checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation); 14648 14649 SynthesizedFunctionScope Scope(*this, MoveAssignOperator); 14650 14651 // The exception specification is needed because we are defining the 14652 // function. 14653 ResolveExceptionSpec(CurrentLocation, 14654 MoveAssignOperator->getType()->castAs<FunctionProtoType>()); 14655 14656 // Add a context note for diagnostics produced after this point. 14657 Scope.addContextNote(CurrentLocation); 14658 14659 // The statements that form the synthesized function body. 14660 SmallVector<Stmt*, 8> Statements; 14661 14662 // The parameter for the "other" object, which we are move from. 14663 ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0); 14664 QualType OtherRefType = 14665 Other->getType()->castAs<RValueReferenceType>()->getPointeeType(); 14666 14667 // Our location for everything implicitly-generated. 14668 SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid() 14669 ? MoveAssignOperator->getEndLoc() 14670 : MoveAssignOperator->getLocation(); 14671 14672 // Builds a reference to the "other" object. 14673 RefBuilder OtherRef(Other, OtherRefType); 14674 // Cast to rvalue. 14675 MoveCastBuilder MoveOther(OtherRef); 14676 14677 // Builds the "this" pointer. 14678 ThisBuilder This; 14679 14680 // Assign base classes. 14681 bool Invalid = false; 14682 for (auto &Base : ClassDecl->bases()) { 14683 // C++11 [class.copy]p28: 14684 // It is unspecified whether subobjects representing virtual base classes 14685 // are assigned more than once by the implicitly-defined copy assignment 14686 // operator. 14687 // FIXME: Do not assign to a vbase that will be assigned by some other base 14688 // class. For a move-assignment, this can result in the vbase being moved 14689 // multiple times. 14690 14691 // Form the assignment: 14692 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other)); 14693 QualType BaseType = Base.getType().getUnqualifiedType(); 14694 if (!BaseType->isRecordType()) { 14695 Invalid = true; 14696 continue; 14697 } 14698 14699 CXXCastPath BasePath; 14700 BasePath.push_back(&Base); 14701 14702 // Construct the "from" expression, which is an implicit cast to the 14703 // appropriately-qualified base type. 14704 CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath); 14705 14706 // Dereference "this". 14707 DerefBuilder DerefThis(This); 14708 14709 // Implicitly cast "this" to the appropriately-qualified base type. 14710 CastBuilder To(DerefThis, 14711 Context.getQualifiedType( 14712 BaseType, MoveAssignOperator->getMethodQualifiers()), 14713 VK_LValue, BasePath); 14714 14715 // Build the move. 14716 StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType, 14717 To, From, 14718 /*CopyingBaseSubobject=*/true, 14719 /*Copying=*/false); 14720 if (Move.isInvalid()) { 14721 MoveAssignOperator->setInvalidDecl(); 14722 return; 14723 } 14724 14725 // Success! Record the move. 14726 Statements.push_back(Move.getAs<Expr>()); 14727 } 14728 14729 // Assign non-static members. 14730 for (auto *Field : ClassDecl->fields()) { 14731 // FIXME: We should form some kind of AST representation for the implied 14732 // memcpy in a union copy operation. 14733 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion()) 14734 continue; 14735 14736 if (Field->isInvalidDecl()) { 14737 Invalid = true; 14738 continue; 14739 } 14740 14741 // Check for members of reference type; we can't move those. 14742 if (Field->getType()->isReferenceType()) { 14743 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) 14744 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName(); 14745 Diag(Field->getLocation(), diag::note_declared_at); 14746 Invalid = true; 14747 continue; 14748 } 14749 14750 // Check for members of const-qualified, non-class type. 14751 QualType BaseType = Context.getBaseElementType(Field->getType()); 14752 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) { 14753 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign) 14754 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName(); 14755 Diag(Field->getLocation(), diag::note_declared_at); 14756 Invalid = true; 14757 continue; 14758 } 14759 14760 // Suppress assigning zero-width bitfields. 14761 if (Field->isZeroLengthBitField(Context)) 14762 continue; 14763 14764 QualType FieldType = Field->getType().getNonReferenceType(); 14765 if (FieldType->isIncompleteArrayType()) { 14766 assert(ClassDecl->hasFlexibleArrayMember() &&((void)0) 14767 "Incomplete array type is not valid")((void)0); 14768 continue; 14769 } 14770 14771 // Build references to the field in the object we're copying from and to. 14772 LookupResult MemberLookup(*this, Field->getDeclName(), Loc, 14773 LookupMemberName); 14774 MemberLookup.addDecl(Field); 14775 MemberLookup.resolveKind(); 14776 MemberBuilder From(MoveOther, OtherRefType, 14777 /*IsArrow=*/false, MemberLookup); 14778 MemberBuilder To(This, getCurrentThisType(), 14779 /*IsArrow=*/true, MemberLookup); 14780 14781 assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue((void)0) 14782 "Member reference with rvalue base must be rvalue except for reference "((void)0) 14783 "members, which aren't allowed for move assignment.")((void)0); 14784 14785 // Build the move of this field. 14786 StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType, 14787 To, From, 14788 /*CopyingBaseSubobject=*/false, 14789 /*Copying=*/false); 14790 if (Move.isInvalid()) { 14791 MoveAssignOperator->setInvalidDecl(); 14792 return; 14793 } 14794 14795 // Success! Record the copy. 14796 Statements.push_back(Move.getAs<Stmt>()); 14797 } 14798 14799 if (!Invalid) { 14800 // Add a "return *this;" 14801 ExprResult ThisObj = 14802 CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc)); 14803 14804 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get()); 14805 if (Return.isInvalid()) 14806 Invalid = true; 14807 else 14808 Statements.push_back(Return.getAs<Stmt>()); 14809 } 14810 14811 if (Invalid) { 14812 MoveAssignOperator->setInvalidDecl(); 14813 return; 14814 } 14815 14816 StmtResult Body; 14817 { 14818 CompoundScopeRAII CompoundScope(*this); 14819 Body = ActOnCompoundStmt(Loc, Loc, Statements, 14820 /*isStmtExpr=*/false); 14821 assert(!Body.isInvalid() && "Compound statement creation cannot fail")((void)0); 14822 } 14823 MoveAssignOperator->setBody(Body.getAs<Stmt>()); 14824 MoveAssignOperator->markUsed(Context); 14825 14826 if (ASTMutationListener *L = getASTMutationListener()) { 14827 L->CompletedImplicitDefinition(MoveAssignOperator); 14828 } 14829} 14830 14831CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor( 14832 CXXRecordDecl *ClassDecl) { 14833 // C++ [class.copy]p4: 14834 // If the class definition does not explicitly declare a copy 14835 // constructor, one is declared implicitly. 14836 assert(ClassDecl->needsImplicitCopyConstructor())((void)0); 14837 14838 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor); 14839 if (DSM.isAlreadyBeingDeclared()) 14840 return nullptr; 14841 14842 QualType ClassType = Context.getTypeDeclType(ClassDecl); 14843 QualType ArgType = ClassType; 14844 bool Const = ClassDecl->implicitCopyConstructorHasConstParam(); 14845 if (Const) 14846 ArgType = ArgType.withConst(); 14847 14848 LangAS AS = getDefaultCXXMethodAddrSpace(); 14849 if (AS != LangAS::Default) 14850 ArgType = Context.getAddrSpaceQualType(ArgType, AS); 14851 14852 ArgType = Context.getLValueReferenceType(ArgType); 14853 14854 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 14855 CXXCopyConstructor, 14856 Const); 14857 14858 DeclarationName Name 14859 = Context.DeclarationNames.getCXXConstructorName( 14860 Context.getCanonicalType(ClassType)); 14861 SourceLocation ClassLoc = ClassDecl->getLocation(); 14862 DeclarationNameInfo NameInfo(Name, ClassLoc); 14863 14864 // An implicitly-declared copy constructor is an inline public 14865 // member of its class. 14866 CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create( 14867 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, 14868 ExplicitSpecifier(), 14869 /*isInline=*/true, 14870 /*isImplicitlyDeclared=*/true, 14871 Constexpr ? ConstexprSpecKind::Constexpr 14872 : ConstexprSpecKind::Unspecified); 14873 CopyConstructor->setAccess(AS_public); 14874 CopyConstructor->setDefaulted(); 14875 14876 if (getLangOpts().CUDA) { 14877 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor, 14878 CopyConstructor, 14879 /* ConstRHS */ Const, 14880 /* Diagnose */ false); 14881 } 14882 14883 setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType); 14884 14885 // During template instantiation of special member functions we need a 14886 // reliable TypeSourceInfo for the parameter types in order to allow functions 14887 // to be substituted. 14888 TypeSourceInfo *TSI = nullptr; 14889 if (inTemplateInstantiation() && ClassDecl->isLambda()) 14890 TSI = Context.getTrivialTypeSourceInfo(ArgType); 14891 14892 // Add the parameter to the constructor. 14893 ParmVarDecl *FromParam = 14894 ParmVarDecl::Create(Context, CopyConstructor, ClassLoc, ClassLoc, 14895 /*IdentifierInfo=*/nullptr, ArgType, 14896 /*TInfo=*/TSI, SC_None, nullptr); 14897 CopyConstructor->setParams(FromParam); 14898 14899 CopyConstructor->setTrivial( 14900 ClassDecl->needsOverloadResolutionForCopyConstructor() 14901 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor) 14902 : ClassDecl->hasTrivialCopyConstructor()); 14903 14904 CopyConstructor->setTrivialForCall( 14905 ClassDecl->hasAttr<TrivialABIAttr>() || 14906 (ClassDecl->needsOverloadResolutionForCopyConstructor() 14907 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor, 14908 TAH_ConsiderTrivialABI) 14909 : ClassDecl->hasTrivialCopyConstructorForCall())); 14910 14911 // Note that we have declared this constructor. 14912 ++getASTContext().NumImplicitCopyConstructorsDeclared; 14913 14914 Scope *S = getScopeForContext(ClassDecl); 14915 CheckImplicitSpecialMemberDeclaration(S, CopyConstructor); 14916 14917 if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) { 14918 ClassDecl->setImplicitCopyConstructorIsDeleted(); 14919 SetDeclDeleted(CopyConstructor, ClassLoc); 14920 } 14921 14922 if (S) 14923 PushOnScopeChains(CopyConstructor, S, false); 14924 ClassDecl->addDecl(CopyConstructor); 14925 14926 return CopyConstructor; 14927} 14928 14929void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation, 14930 CXXConstructorDecl *CopyConstructor) { 14931 assert((CopyConstructor->isDefaulted() &&((void)0) 14932 CopyConstructor->isCopyConstructor() &&((void)0) 14933 !CopyConstructor->doesThisDeclarationHaveABody() &&((void)0) 14934 !CopyConstructor->isDeleted()) &&((void)0) 14935 "DefineImplicitCopyConstructor - call it for implicit copy ctor")((void)0); 14936 if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl()) 14937 return; 14938 14939 CXXRecordDecl *ClassDecl = CopyConstructor->getParent(); 14940 assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor")((void)0); 14941 14942 SynthesizedFunctionScope Scope(*this, CopyConstructor); 14943 14944 // The exception specification is needed because we are defining the 14945 // function. 14946 ResolveExceptionSpec(CurrentLocation, 14947 CopyConstructor->getType()->castAs<FunctionProtoType>()); 14948 MarkVTableUsed(CurrentLocation, ClassDecl); 14949 14950 // Add a context note for diagnostics produced after this point. 14951 Scope.addContextNote(CurrentLocation); 14952 14953 // C++11 [class.copy]p7: 14954 // The [definition of an implicitly declared copy constructor] is 14955 // deprecated if the class has a user-declared copy assignment operator 14956 // or a user-declared destructor. 14957 if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit()) 14958 diagnoseDeprecatedCopyOperation(*this, CopyConstructor); 14959 14960 if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) { 14961 CopyConstructor->setInvalidDecl(); 14962 } else { 14963 SourceLocation Loc = CopyConstructor->getEndLoc().isValid() 14964 ? CopyConstructor->getEndLoc() 14965 : CopyConstructor->getLocation(); 14966 Sema::CompoundScopeRAII CompoundScope(*this); 14967 CopyConstructor->setBody( 14968 ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>()); 14969 CopyConstructor->markUsed(Context); 14970 } 14971 14972 if (ASTMutationListener *L = getASTMutationListener()) { 14973 L->CompletedImplicitDefinition(CopyConstructor); 14974 } 14975} 14976 14977CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor( 14978 CXXRecordDecl *ClassDecl) { 14979 assert(ClassDecl->needsImplicitMoveConstructor())((void)0); 14980 14981 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor); 14982 if (DSM.isAlreadyBeingDeclared()) 14983 return nullptr; 14984 14985 QualType ClassType = Context.getTypeDeclType(ClassDecl); 14986 14987 QualType ArgType = ClassType; 14988 LangAS AS = getDefaultCXXMethodAddrSpace(); 14989 if (AS != LangAS::Default) 14990 ArgType = Context.getAddrSpaceQualType(ClassType, AS); 14991 ArgType = Context.getRValueReferenceType(ArgType); 14992 14993 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl, 14994 CXXMoveConstructor, 14995 false); 14996 14997 DeclarationName Name 14998 = Context.DeclarationNames.getCXXConstructorName( 14999 Context.getCanonicalType(ClassType)); 15000 SourceLocation ClassLoc = ClassDecl->getLocation(); 15001 DeclarationNameInfo NameInfo(Name, ClassLoc); 15002 15003 // C++11 [class.copy]p11: 15004 // An implicitly-declared copy/move constructor is an inline public 15005 // member of its class. 15006 CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create( 15007 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr, 15008 ExplicitSpecifier(), 15009 /*isInline=*/true, 15010 /*isImplicitlyDeclared=*/true, 15011 Constexpr ? ConstexprSpecKind::Constexpr 15012 : ConstexprSpecKind::Unspecified); 15013 MoveConstructor->setAccess(AS_public); 15014 MoveConstructor->setDefaulted(); 15015 15016 if (getLangOpts().CUDA) { 15017 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor, 15018 MoveConstructor, 15019 /* ConstRHS */ false, 15020 /* Diagnose */ false); 15021 } 15022 15023 setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType); 15024 15025 // Add the parameter to the constructor. 15026 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor, 15027 ClassLoc, ClassLoc, 15028 /*IdentifierInfo=*/nullptr, 15029 ArgType, /*TInfo=*/nullptr, 15030 SC_None, nullptr); 15031 MoveConstructor->setParams(FromParam); 15032 15033 MoveConstructor->setTrivial( 15034 ClassDecl->needsOverloadResolutionForMoveConstructor() 15035 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor) 15036 : ClassDecl->hasTrivialMoveConstructor()); 15037 15038 MoveConstructor->setTrivialForCall( 15039 ClassDecl->hasAttr<TrivialABIAttr>() || 15040 (ClassDecl->needsOverloadResolutionForMoveConstructor() 15041 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor, 15042 TAH_ConsiderTrivialABI) 15043 : ClassDecl->hasTrivialMoveConstructorForCall())); 15044 15045 // Note that we have declared this constructor. 15046 ++getASTContext().NumImplicitMoveConstructorsDeclared; 15047 15048 Scope *S = getScopeForContext(ClassDecl); 15049 CheckImplicitSpecialMemberDeclaration(S, MoveConstructor); 15050 15051 if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) { 15052 ClassDecl->setImplicitMoveConstructorIsDeleted(); 15053 SetDeclDeleted(MoveConstructor, ClassLoc); 15054 } 15055 15056 if (S) 15057 PushOnScopeChains(MoveConstructor, S, false); 15058 ClassDecl->addDecl(MoveConstructor); 15059 15060 return MoveConstructor; 15061} 15062 15063void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation, 15064 CXXConstructorDecl *MoveConstructor) { 15065 assert((MoveConstructor->isDefaulted() &&((void)0) 15066 MoveConstructor->isMoveConstructor() &&((void)0) 15067 !MoveConstructor->doesThisDeclarationHaveABody() &&((void)0) 15068 !MoveConstructor->isDeleted()) &&((void)0) 15069 "DefineImplicitMoveConstructor - call it for implicit move ctor")((void)0); 15070 if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl()) 15071 return; 15072 15073 CXXRecordDecl *ClassDecl = MoveConstructor->getParent(); 15074 assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor")((void)0); 15075 15076 SynthesizedFunctionScope Scope(*this, MoveConstructor); 15077 15078 // The exception specification is needed because we are defining the 15079 // function. 15080 ResolveExceptionSpec(CurrentLocation, 15081 MoveConstructor->getType()->castAs<FunctionProtoType>()); 15082 MarkVTableUsed(CurrentLocation, ClassDecl); 15083 15084 // Add a context note for diagnostics produced after this point. 15085 Scope.addContextNote(CurrentLocation); 15086 15087 if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) { 15088 MoveConstructor->setInvalidDecl(); 15089 } else { 15090 SourceLocation Loc = MoveConstructor->getEndLoc().isValid() 15091 ? MoveConstructor->getEndLoc() 15092 : MoveConstructor->getLocation(); 15093 Sema::CompoundScopeRAII CompoundScope(*this); 15094 MoveConstructor->setBody(ActOnCompoundStmt( 15095 Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>()); 15096 MoveConstructor->markUsed(Context); 15097 } 15098 15099 if (ASTMutationListener *L = getASTMutationListener()) { 15100 L->CompletedImplicitDefinition(MoveConstructor); 15101 } 15102} 15103 15104bool Sema::isImplicitlyDeleted(FunctionDecl *FD) { 15105 return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD); 15106} 15107 15108void Sema::DefineImplicitLambdaToFunctionPointerConversion( 15109 SourceLocation CurrentLocation, 15110 CXXConversionDecl *Conv) { 15111 SynthesizedFunctionScope Scope(*this, Conv); 15112 assert(!Conv->getReturnType()->isUndeducedType())((void)0); 15113 15114 QualType ConvRT = Conv->getType()->castAs<FunctionType>()->getReturnType(); 15115 CallingConv CC = 15116 ConvRT->getPointeeType()->castAs<FunctionType>()->getCallConv(); 15117 15118 CXXRecordDecl *Lambda = Conv->getParent(); 15119 FunctionDecl *CallOp = Lambda->getLambdaCallOperator(); 15120 FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker(CC); 15121 15122 if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) { 15123 CallOp = InstantiateFunctionDeclaration( 15124 CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation); 15125 if (!CallOp) 15126 return; 15127 15128 Invoker = InstantiateFunctionDeclaration( 15129 Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation); 15130 if (!Invoker) 15131 return; 15132 } 15133 15134 if (CallOp->isInvalidDecl()) 15135 return; 15136 15137 // Mark the call operator referenced (and add to pending instantiations 15138 // if necessary). 15139 // For both the conversion and static-invoker template specializations 15140 // we construct their body's in this function, so no need to add them 15141 // to the PendingInstantiations. 15142 MarkFunctionReferenced(CurrentLocation, CallOp); 15143 15144 // Fill in the __invoke function with a dummy implementation. IR generation 15145 // will fill in the actual details. Update its type in case it contained 15146 // an 'auto'. 15147 Invoker->markUsed(Context); 15148 Invoker->setReferenced(); 15149 Invoker->setType(Conv->getReturnType()->getPointeeType()); 15150 Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation())); 15151 15152 // Construct the body of the conversion function { return __invoke; }. 15153 Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(), 15154 VK_LValue, Conv->getLocation()); 15155 assert(FunctionRef && "Can't refer to __invoke function?")((void)0); 15156 Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get(); 15157 Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(), 15158 Conv->getLocation())); 15159 Conv->markUsed(Context); 15160 Conv->setReferenced(); 15161 15162 if (ASTMutationListener *L = getASTMutationListener()) { 15163 L->CompletedImplicitDefinition(Conv); 15164 L->CompletedImplicitDefinition(Invoker); 15165 } 15166} 15167 15168 15169 15170void Sema::DefineImplicitLambdaToBlockPointerConversion( 15171 SourceLocation CurrentLocation, 15172 CXXConversionDecl *Conv) 15173{ 15174 assert(!Conv->getParent()->isGenericLambda())((void)0); 15175 15176 SynthesizedFunctionScope Scope(*this, Conv); 15177 15178 // Copy-initialize the lambda object as needed to capture it. 15179 Expr *This = ActOnCXXThis(CurrentLocation).get(); 15180 Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get(); 15181 15182 ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation, 15183 Conv->getLocation(), 15184 Conv, DerefThis); 15185 15186 // If we're not under ARC, make sure we still get the _Block_copy/autorelease 15187 // behavior. Note that only the general conversion function does this 15188 // (since it's unusable otherwise); in the case where we inline the 15189 // block literal, it has block literal lifetime semantics. 15190 if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount) 15191 BuildBlock = ImplicitCastExpr::Create( 15192 Context, BuildBlock.get()->getType(), CK_CopyAndAutoreleaseBlockObject, 15193 BuildBlock.get(), nullptr, VK_PRValue, FPOptionsOverride()); 15194 15195 if (BuildBlock.isInvalid()) { 15196 Diag(CurrentLocation, diag::note_lambda_to_block_conv); 15197 Conv->setInvalidDecl(); 15198 return; 15199 } 15200 15201 // Create the return statement that returns the block from the conversion 15202 // function. 15203 StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get()); 15204 if (Return.isInvalid()) { 15205 Diag(CurrentLocation, diag::note_lambda_to_block_conv); 15206 Conv->setInvalidDecl(); 15207 return; 15208 } 15209 15210 // Set the body of the conversion function. 15211 Stmt *ReturnS = Return.get(); 15212 Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(), 15213 Conv->getLocation())); 15214 Conv->markUsed(Context); 15215 15216 // We're done; notify the mutation listener, if any. 15217 if (ASTMutationListener *L = getASTMutationListener()) { 15218 L->CompletedImplicitDefinition(Conv); 15219 } 15220} 15221 15222/// Determine whether the given list arguments contains exactly one 15223/// "real" (non-default) argument. 15224static bool hasOneRealArgument(MultiExprArg Args) { 15225 switch (Args.size()) { 15226 case 0: 15227 return false; 15228 15229 default: 15230 if (!Args[1]->isDefaultArgument()) 15231 return false; 15232 15233 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 15234 case 1: 15235 return !Args[0]->isDefaultArgument(); 15236 } 15237 15238 return false; 15239} 15240 15241ExprResult 15242Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, 15243 NamedDecl *FoundDecl, 15244 CXXConstructorDecl *Constructor, 15245 MultiExprArg ExprArgs, 15246 bool HadMultipleCandidates, 15247 bool IsListInitialization, 15248 bool IsStdInitListInitialization, 15249 bool RequiresZeroInit, 15250 unsigned ConstructKind, 15251 SourceRange ParenRange) { 15252 bool Elidable = false; 15253 15254 // C++0x [class.copy]p34: 15255 // When certain criteria are met, an implementation is allowed to 15256 // omit the copy/move construction of a class object, even if the 15257 // copy/move constructor and/or destructor for the object have 15258 // side effects. [...] 15259 // - when a temporary class object that has not been bound to a 15260 // reference (12.2) would be copied/moved to a class object 15261 // with the same cv-unqualified type, the copy/move operation 15262 // can be omitted by constructing the temporary object 15263 // directly into the target of the omitted copy/move 15264 if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor && 15265 // FIXME: Converting constructors should also be accepted. 15266 // But to fix this, the logic that digs down into a CXXConstructExpr 15267 // to find the source object needs to handle it. 15268 // Right now it assumes the source object is passed directly as the 15269 // first argument. 15270 Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) { 15271 Expr *SubExpr = ExprArgs[0]; 15272 // FIXME: Per above, this is also incorrect if we want to accept 15273 // converting constructors, as isTemporaryObject will 15274 // reject temporaries with different type from the 15275 // CXXRecord itself. 15276 Elidable = SubExpr->isTemporaryObject( 15277 Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext())); 15278 } 15279 15280 return BuildCXXConstructExpr(ConstructLoc, DeclInitType, 15281 FoundDecl, Constructor, 15282 Elidable, ExprArgs, HadMultipleCandidates, 15283 IsListInitialization, 15284 IsStdInitListInitialization, RequiresZeroInit, 15285 ConstructKind, ParenRange); 15286} 15287 15288ExprResult 15289Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, 15290 NamedDecl *FoundDecl, 15291 CXXConstructorDecl *Constructor, 15292 bool Elidable, 15293 MultiExprArg ExprArgs, 15294 bool HadMultipleCandidates, 15295 bool IsListInitialization, 15296 bool IsStdInitListInitialization, 15297 bool RequiresZeroInit, 15298 unsigned ConstructKind, 15299 SourceRange ParenRange) { 15300 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) { 15301 Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow); 15302 if (DiagnoseUseOfDecl(Constructor, ConstructLoc)) 15303 return ExprError(); 15304 } 15305 15306 return BuildCXXConstructExpr( 15307 ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs, 15308 HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization, 15309 RequiresZeroInit, ConstructKind, ParenRange); 15310} 15311 15312/// BuildCXXConstructExpr - Creates a complete call to a constructor, 15313/// including handling of its default argument expressions. 15314ExprResult 15315Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType, 15316 CXXConstructorDecl *Constructor, 15317 bool Elidable, 15318 MultiExprArg ExprArgs, 15319 bool HadMultipleCandidates, 15320 bool IsListInitialization, 15321 bool IsStdInitListInitialization, 15322 bool RequiresZeroInit, 15323 unsigned ConstructKind, 15324 SourceRange ParenRange) { 15325 assert(declaresSameEntity(((void)0) 15326 Constructor->getParent(),((void)0) 15327 DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&((void)0) 15328 "given constructor for wrong type")((void)0); 15329 MarkFunctionReferenced(ConstructLoc, Constructor); 15330 if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor)) 15331 return ExprError(); 15332 if (getLangOpts().SYCLIsDevice && 15333 !checkSYCLDeviceFunction(ConstructLoc, Constructor)) 15334 return ExprError(); 15335 15336 return CheckForImmediateInvocation( 15337 CXXConstructExpr::Create( 15338 Context, DeclInitType, ConstructLoc, Constructor, Elidable, ExprArgs, 15339 HadMultipleCandidates, IsListInitialization, 15340 IsStdInitListInitialization, RequiresZeroInit, 15341 static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind), 15342 ParenRange), 15343 Constructor); 15344} 15345 15346ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) { 15347 assert(Field->hasInClassInitializer())((void)0); 15348 15349 // If we already have the in-class initializer nothing needs to be done. 15350 if (Field->getInClassInitializer())

←

Calling 'FieldDecl::getInClassInitializer'

→

←

Returning from 'FieldDecl::getInClassInitializer'

→

←

Taking false branch

→

15351 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext); 15352 15353 // If we might have already tried and failed to instantiate, don't try again. 15354 if (Field->isInvalidDecl())

←

Assuming the condition is false

→

←

Taking false branch

→

15355 return ExprError(); 15356 15357 // Maybe we haven't instantiated the in-class initializer. Go check the 15358 // pattern FieldDecl to see if it has one. 15359 CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent()); 15360 15361 if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {

←

Calling 'isTemplateInstantiation'

→

←

Returning from 'isTemplateInstantiation'

→

←

Taking true branch

→

15362 CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern(); 15363 DeclContext::lookup_result Lookup = 15364 ClassPattern->lookup(Field->getDeclName()); 15365 15366 FieldDecl *Pattern = nullptr;

←

'Pattern' initialized to a null pointer value

→

15367 for (auto L : Lookup) { 15368 if (isa<FieldDecl>(L)) { 15369 Pattern = cast<FieldDecl>(L); 15370 break; 15371 } 15372 } 15373 assert(Pattern && "We must have set the Pattern!")((void)0); 15374 15375 if (!Pattern->hasInClassInitializer() ||

←

Called C++ object pointer is null

15376 InstantiateInClassInitializer(Loc, Field, Pattern, 15377 getTemplateInstantiationArgs(Field))) { 15378 // Don't diagnose this again. 15379 Field->setInvalidDecl(); 15380 return ExprError(); 15381 } 15382 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext); 15383 } 15384 15385 // DR1351: 15386 // If the brace-or-equal-initializer of a non-static data member 15387 // invokes a defaulted default constructor of its class or of an 15388 // enclosing class in a potentially evaluated subexpression, the 15389 // program is ill-formed. 15390 // 15391 // This resolution is unworkable: the exception specification of the 15392 // default constructor can be needed in an unevaluated context, in 15393 // particular, in the operand of a noexcept-expression, and we can be 15394 // unable to compute an exception specification for an enclosed class. 15395 // 15396 // Any attempt to resolve the exception specification of a defaulted default 15397 // constructor before the initializer is lexically complete will ultimately 15398 // come here at which point we can diagnose it. 15399 RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext(); 15400 Diag(Loc, diag::err_default_member_initializer_not_yet_parsed) 15401 << OutermostClass << Field; 15402 Diag(Field->getEndLoc(), 15403 diag::note_default_member_initializer_not_yet_parsed); 15404 // Recover by marking the field invalid, unless we're in a SFINAE context. 15405 if (!isSFINAEContext()) 15406 Field->setInvalidDecl(); 15407 return ExprError(); 15408} 15409 15410void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) { 15411 if (VD->isInvalidDecl()) return; 15412 // If initializing the variable failed, don't also diagnose problems with 15413 // the desctructor, they're likely related. 15414 if (VD->getInit() && VD->getInit()->containsErrors()) 15415 return; 15416 15417 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl()); 15418 if (ClassDecl->isInvalidDecl()) return; 15419 if (ClassDecl->hasIrrelevantDestructor()) return; 15420 if (ClassDecl->isDependentContext()) return; 15421 15422 if (VD->isNoDestroy(getASTContext())) 15423 return; 15424 15425 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl); 15426 15427 // If this is an array, we'll require the destructor during initialization, so 15428 // we can skip over this. We still want to emit exit-time destructor warnings 15429 // though. 15430 if (!VD->getType()->isArrayType()) { 15431 MarkFunctionReferenced(VD->getLocation(), Destructor); 15432 CheckDestructorAccess(VD->getLocation(), Destructor, 15433 PDiag(diag::err_access_dtor_var) 15434 << VD->getDeclName() << VD->getType()); 15435 DiagnoseUseOfDecl(Destructor, VD->getLocation()); 15436 } 15437 15438 if (Destructor->isTrivial()) return; 15439 15440 // If the destructor is constexpr, check whether the variable has constant 15441 // destruction now. 15442 if (Destructor->isConstexpr()) { 15443 bool HasConstantInit = false; 15444 if (VD->getInit() && !VD->getInit()->isValueDependent()) 15445 HasConstantInit = VD->evaluateValue(); 15446 SmallVector<PartialDiagnosticAt, 8> Notes; 15447 if (!VD->evaluateDestruction(Notes) && VD->isConstexpr() && 15448 HasConstantInit) { 15449 Diag(VD->getLocation(), 15450 diag::err_constexpr_var_requires_const_destruction) << VD; 15451 for (unsigned I = 0, N = Notes.size(); I != N; ++I) 15452 Diag(Notes[I].first, Notes[I].second); 15453 } 15454 } 15455 15456 if (!VD->hasGlobalStorage()) return; 15457 15458 // Emit warning for non-trivial dtor in global scope (a real global, 15459 // class-static, function-static). 15460 Diag(VD->getLocation(), diag::warn_exit_time_destructor); 15461 15462 // TODO: this should be re-enabled for static locals by !CXAAtExit 15463 if (!VD->isStaticLocal()) 15464 Diag(VD->getLocation(), diag::warn_global_destructor); 15465} 15466 15467/// Given a constructor and the set of arguments provided for the 15468/// constructor, convert the arguments and add any required default arguments 15469/// to form a proper call to this constructor. 15470/// 15471/// \returns true if an error occurred, false otherwise. 15472bool Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor, 15473 QualType DeclInitType, MultiExprArg ArgsPtr, 15474 SourceLocation Loc, 15475 SmallVectorImpl<Expr *> &ConvertedArgs, 15476 bool AllowExplicit, 15477 bool IsListInitialization) { 15478 // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall. 15479 unsigned NumArgs = ArgsPtr.size(); 15480 Expr **Args = ArgsPtr.data(); 15481 15482 const auto *Proto = Constructor->getType()->castAs<FunctionProtoType>(); 15483 unsigned NumParams = Proto->getNumParams(); 15484 15485 // If too few arguments are available, we'll fill in the rest with defaults. 15486 if (NumArgs < NumParams) 15487 ConvertedArgs.reserve(NumParams); 15488 else 15489 ConvertedArgs.reserve(NumArgs); 15490 15491 VariadicCallType CallType = 15492 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply; 15493 SmallVector<Expr *, 8> AllArgs; 15494 bool Invalid = GatherArgumentsForCall(Loc, Constructor, 15495 Proto, 0, 15496 llvm::makeArrayRef(Args, NumArgs), 15497 AllArgs, 15498 CallType, AllowExplicit, 15499 IsListInitialization); 15500 ConvertedArgs.append(AllArgs.begin(), AllArgs.end()); 15501 15502 DiagnoseSentinelCalls(Constructor, Loc, AllArgs); 15503 15504 CheckConstructorCall(Constructor, DeclInitType, 15505 llvm::makeArrayRef(AllArgs.data(), AllArgs.size()), 15506 Proto, Loc); 15507 15508 return Invalid; 15509} 15510 15511static inline bool 15512CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef, 15513 const FunctionDecl *FnDecl) { 15514 const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext(); 15515 if (isa<NamespaceDecl>(DC)) { 15516 return SemaRef.Diag(FnDecl->getLocation(), 15517 diag::err_operator_new_delete_declared_in_namespace) 15518 << FnDecl->getDeclName(); 15519 } 15520 15521 if (isa<TranslationUnitDecl>(DC) && 15522 FnDecl->getStorageClass() == SC_Static) { 15523 return SemaRef.Diag(FnDecl->getLocation(), 15524 diag::err_operator_new_delete_declared_static) 15525 << FnDecl->getDeclName(); 15526 } 15527 15528 return false; 15529} 15530 15531static CanQualType RemoveAddressSpaceFromPtr(Sema &SemaRef, 15532 const PointerType *PtrTy) { 15533 auto &Ctx = SemaRef.Context; 15534 Qualifiers PtrQuals = PtrTy->getPointeeType().getQualifiers(); 15535 PtrQuals.removeAddressSpace(); 15536 return Ctx.getPointerType(Ctx.getCanonicalType(Ctx.getQualifiedType( 15537 PtrTy->getPointeeType().getUnqualifiedType(), PtrQuals))); 15538} 15539 15540static inline bool 15541CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl, 15542 CanQualType ExpectedResultType, 15543 CanQualType ExpectedFirstParamType, 15544 unsigned DependentParamTypeDiag, 15545 unsigned InvalidParamTypeDiag) { 15546 QualType ResultType = 15547 FnDecl->getType()->castAs<FunctionType>()->getReturnType(); 15548 15549 if (SemaRef.getLangOpts().OpenCLCPlusPlus) { 15550 // The operator is valid on any address space for OpenCL. 15551 // Drop address space from actual and expected result types. 15552 if (const auto *PtrTy = ResultType->getAs<PointerType>()) 15553 ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy); 15554 15555 if (auto ExpectedPtrTy = ExpectedResultType->getAs<PointerType>()) 15556 ExpectedResultType = RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy); 15557 } 15558 15559 // Check that the result type is what we expect. 15560 if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType) { 15561 // Reject even if the type is dependent; an operator delete function is 15562 // required to have a non-dependent result type. 15563 return SemaRef.Diag( 15564 FnDecl->getLocation(), 15565 ResultType->isDependentType() 15566 ? diag::err_operator_new_delete_dependent_result_type 15567 : diag::err_operator_new_delete_invalid_result_type) 15568 << FnDecl->getDeclName() << ExpectedResultType; 15569 } 15570 15571 // A function template must have at least 2 parameters. 15572 if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2) 15573 return SemaRef.Diag(FnDecl->getLocation(), 15574 diag::err_operator_new_delete_template_too_few_parameters) 15575 << FnDecl->getDeclName(); 15576 15577 // The function decl must have at least 1 parameter. 15578 if (FnDecl->getNumParams() == 0) 15579 return SemaRef.Diag(FnDecl->getLocation(), 15580 diag::err_operator_new_delete_too_few_parameters) 15581 << FnDecl->getDeclName(); 15582 15583 QualType FirstParamType = FnDecl->getParamDecl(0)->getType(); 15584 if (SemaRef.getLangOpts().OpenCLCPlusPlus) { 15585 // The operator is valid on any address space for OpenCL. 15586 // Drop address space from actual and expected first parameter types. 15587 if (const auto *PtrTy = 15588 FnDecl->getParamDecl(0)->getType()->getAs<PointerType>()) 15589 FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy); 15590 15591 if (auto ExpectedPtrTy = ExpectedFirstParamType->getAs<PointerType>()) 15592 ExpectedFirstParamType = 15593 RemoveAddressSpaceFromPtr(SemaRef, ExpectedPtrTy); 15594 } 15595 15596 // Check that the first parameter type is what we expect. 15597 if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() != 15598 ExpectedFirstParamType) { 15599 // The first parameter type is not allowed to be dependent. As a tentative 15600 // DR resolution, we allow a dependent parameter type if it is the right 15601 // type anyway, to allow destroying operator delete in class templates. 15602 return SemaRef.Diag(FnDecl->getLocation(), FirstParamType->isDependentType() 15603 ? DependentParamTypeDiag 15604 : InvalidParamTypeDiag) 15605 << FnDecl->getDeclName() << ExpectedFirstParamType; 15606 } 15607 15608 return false; 15609} 15610 15611static bool 15612CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) { 15613 // C++ [basic.stc.dynamic.allocation]p1: 15614 // A program is ill-formed if an allocation function is declared in a 15615 // namespace scope other than global scope or declared static in global 15616 // scope. 15617 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) 15618 return true; 15619 15620 CanQualType SizeTy = 15621 SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType()); 15622 15623 // C++ [basic.stc.dynamic.allocation]p1: 15624 // The return type shall be void*. The first parameter shall have type 15625 // std::size_t. 15626 if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy, 15627 SizeTy, 15628 diag::err_operator_new_dependent_param_type, 15629 diag::err_operator_new_param_type)) 15630 return true; 15631 15632 // C++ [basic.stc.dynamic.allocation]p1: 15633 // The first parameter shall not have an associated default argument. 15634 if (FnDecl->getParamDecl(0)->hasDefaultArg()) 15635 return SemaRef.Diag(FnDecl->getLocation(), 15636 diag::err_operator_new_default_arg) 15637 << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange(); 15638 15639 return false; 15640} 15641 15642static bool 15643CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) { 15644 // C++ [basic.stc.dynamic.deallocation]p1: 15645 // A program is ill-formed if deallocation functions are declared in a 15646 // namespace scope other than global scope or declared static in global 15647 // scope. 15648 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl)) 15649 return true; 15650 15651 auto *MD = dyn_cast<CXXMethodDecl>(FnDecl); 15652 15653 // C++ P0722: 15654 // Within a class C, the first parameter of a destroying operator delete 15655 // shall be of type C *. The first parameter of any other deallocation 15656 // function shall be of type void *. 15657 CanQualType ExpectedFirstParamType = 15658 MD && MD->isDestroyingOperatorDelete() 15659 ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType( 15660 SemaRef.Context.getRecordType(MD->getParent()))) 15661 : SemaRef.Context.VoidPtrTy; 15662 15663 // C++ [basic.stc.dynamic.deallocation]p2: 15664 // Each deallocation function shall return void 15665 if (CheckOperatorNewDeleteTypes( 15666 SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType, 15667 diag::err_operator_delete_dependent_param_type, 15668 diag::err_operator_delete_param_type)) 15669 return true; 15670 15671 // C++ P0722: 15672 // A destroying operator delete shall be a usual deallocation function. 15673 if (MD && !MD->getParent()->isDependentContext() && 15674 MD->isDestroyingOperatorDelete() && 15675 !SemaRef.isUsualDeallocationFunction(MD)) { 15676 SemaRef.Diag(MD->getLocation(), 15677 diag::err_destroying_operator_delete_not_usual); 15678 return true; 15679 } 15680 15681 return false; 15682} 15683 15684/// CheckOverloadedOperatorDeclaration - Check whether the declaration 15685/// of this overloaded operator is well-formed. If so, returns false; 15686/// otherwise, emits appropriate diagnostics and returns true. 15687bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) { 15688 assert(FnDecl && FnDecl->isOverloadedOperator() &&((void)0) 15689 "Expected an overloaded operator declaration")((void)0); 15690 15691 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator(); 15692 15693 // C++ [over.oper]p5: 15694 // The allocation and deallocation functions, operator new, 15695 // operator new[], operator delete and operator delete[], are 15696 // described completely in 3.7.3. The attributes and restrictions 15697 // found in the rest of this subclause do not apply to them unless 15698 // explicitly stated in 3.7.3. 15699 if (Op == OO_Delete || Op == OO_Array_Delete) 15700 return CheckOperatorDeleteDeclaration(*this, FnDecl); 15701 15702 if (Op == OO_New || Op == OO_Array_New) 15703 return CheckOperatorNewDeclaration(*this, FnDecl); 15704 15705 // C++ [over.oper]p6: 15706 // An operator function shall either be a non-static member 15707 // function or be a non-member function and have at least one 15708 // parameter whose type is a class, a reference to a class, an 15709 // enumeration, or a reference to an enumeration. 15710 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) { 15711 if (MethodDecl->isStatic()) 15712 return Diag(FnDecl->getLocation(), 15713 diag::err_operator_overload_static) << FnDecl->getDeclName(); 15714 } else { 15715 bool ClassOrEnumParam = false; 15716 for (auto Param : FnDecl->parameters()) { 15717 QualType ParamType = Param->getType().getNonReferenceType(); 15718 if (ParamType->isDependentType() || ParamType->isRecordType() || 15719 ParamType->isEnumeralType()) { 15720 ClassOrEnumParam = true; 15721 break; 15722 } 15723 } 15724 15725 if (!ClassOrEnumParam) 15726 return Diag(FnDecl->getLocation(), 15727 diag::err_operator_overload_needs_class_or_enum) 15728 << FnDecl->getDeclName(); 15729 } 15730 15731 // C++ [over.oper]p8: 15732 // An operator function cannot have default arguments (8.3.6), 15733 // except where explicitly stated below. 15734 // 15735 // Only the function-call operator allows default arguments 15736 // (C++ [over.call]p1). 15737 if (Op != OO_Call) { 15738 for (auto Param : FnDecl->parameters()) { 15739 if (Param->hasDefaultArg()) 15740 return Diag(Param->getLocation(), 15741 diag::err_operator_overload_default_arg) 15742 << FnDecl->getDeclName() << Param->getDefaultArgRange(); 15743 } 15744 } 15745 15746 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = { 15747 { false, false, false } 15748#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \ 15749 , { Unary, Binary, MemberOnly } 15750#include "clang/Basic/OperatorKinds.def" 15751 }; 15752 15753 bool CanBeUnaryOperator = OperatorUses[Op][0]; 15754 bool CanBeBinaryOperator = OperatorUses[Op][1]; 15755 bool MustBeMemberOperator = OperatorUses[Op][2]; 15756 15757 // C++ [over.oper]p8: 15758 // [...] Operator functions cannot have more or fewer parameters 15759 // than the number required for the corresponding operator, as 15760 // described in the rest of this subclause. 15761 unsigned NumParams = FnDecl->getNumParams() 15762 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0); 15763 if (Op != OO_Call && 15764 ((NumParams == 1 && !CanBeUnaryOperator) || 15765 (NumParams == 2 && !CanBeBinaryOperator) || 15766 (NumParams < 1) || (NumParams > 2))) { 15767 // We have the wrong number of parameters. 15768 unsigned ErrorKind; 15769 if (CanBeUnaryOperator && CanBeBinaryOperator) { 15770 ErrorKind = 2; // 2 -> unary or binary. 15771 } else if (CanBeUnaryOperator) { 15772 ErrorKind = 0; // 0 -> unary 15773 } else { 15774 assert(CanBeBinaryOperator &&((void)0) 15775 "All non-call overloaded operators are unary or binary!")((void)0); 15776 ErrorKind = 1; // 1 -> binary 15777 } 15778 15779 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be) 15780 << FnDecl->getDeclName() << NumParams << ErrorKind; 15781 } 15782 15783 // Overloaded operators other than operator() cannot be variadic. 15784 if (Op != OO_Call && 15785 FnDecl->getType()->castAs<FunctionProtoType>()->isVariadic()) { 15786 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic) 15787 << FnDecl->getDeclName(); 15788 } 15789 15790 // Some operators must be non-static member functions. 15791 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) { 15792 return Diag(FnDecl->getLocation(), 15793 diag::err_operator_overload_must_be_member) 15794 << FnDecl->getDeclName(); 15795 } 15796 15797 // C++ [over.inc]p1: 15798 // The user-defined function called operator++ implements the 15799 // prefix and postfix ++ operator. If this function is a member 15800 // function with no parameters, or a non-member function with one 15801 // parameter of class or enumeration type, it defines the prefix 15802 // increment operator ++ for objects of that type. If the function 15803 // is a member function with one parameter (which shall be of type 15804 // int) or a non-member function with two parameters (the second 15805 // of which shall be of type int), it defines the postfix 15806 // increment operator ++ for objects of that type. 15807 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) { 15808 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1); 15809 QualType ParamType = LastParam->getType(); 15810 15811 if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) && 15812 !ParamType->isDependentType()) 15813 return Diag(LastParam->getLocation(), 15814 diag::err_operator_overload_post_incdec_must_be_int) 15815 << LastParam->getType() << (Op == OO_MinusMinus); 15816 } 15817 15818 return false; 15819} 15820 15821static bool 15822checkLiteralOperatorTemplateParameterList(Sema &SemaRef, 15823 FunctionTemplateDecl *TpDecl) { 15824 TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters(); 15825 15826 // Must have one or two template parameters. 15827 if (TemplateParams->size() == 1) { 15828 NonTypeTemplateParmDecl *PmDecl = 15829 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0)); 15830 15831 // The template parameter must be a char parameter pack. 15832 if (PmDecl && PmDecl->isTemplateParameterPack() && 15833 SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy)) 15834 return false; 15835 15836 // C++20 [over.literal]p5: 15837 // A string literal operator template is a literal operator template 15838 // whose template-parameter-list comprises a single non-type 15839 // template-parameter of class type. 15840 // 15841 // As a DR resolution, we also allow placeholders for deduced class 15842 // template specializations. 15843 if (SemaRef.getLangOpts().CPlusPlus20 && 15844 !PmDecl->isTemplateParameterPack() && 15845 (PmDecl->getType()->isRecordType() || 15846 PmDecl->getType()->getAs<DeducedTemplateSpecializationType>())) 15847 return false; 15848 } else if (TemplateParams->size() == 2) { 15849 TemplateTypeParmDecl *PmType = 15850 dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0)); 15851 NonTypeTemplateParmDecl *PmArgs = 15852 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1)); 15853 15854 // The second template parameter must be a parameter pack with the 15855 // first template parameter as its type. 15856 if (PmType && PmArgs && !PmType->isTemplateParameterPack() && 15857 PmArgs->isTemplateParameterPack()) { 15858 const TemplateTypeParmType *TArgs = 15859 PmArgs->getType()->getAs<TemplateTypeParmType>(); 15860 if (TArgs && TArgs->getDepth() == PmType->getDepth() && 15861 TArgs->getIndex() == PmType->getIndex()) { 15862 if (!SemaRef.inTemplateInstantiation()) 15863 SemaRef.Diag(TpDecl->getLocation(), 15864 diag::ext_string_literal_operator_template); 15865 return false; 15866 } 15867 } 15868 } 15869 15870 SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(), 15871 diag::err_literal_operator_template) 15872 << TpDecl->getTemplateParameters()->getSourceRange(); 15873 return true; 15874} 15875 15876/// CheckLiteralOperatorDeclaration - Check whether the declaration 15877/// of this literal operator function is well-formed. If so, returns 15878/// false; otherwise, emits appropriate diagnostics and returns true. 15879bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) { 15880 if (isa<CXXMethodDecl>(FnDecl)) { 15881 Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace) 15882 << FnDecl->getDeclName(); 15883 return true; 15884 } 15885 15886 if (FnDecl->isExternC()) { 15887 Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c); 15888 if (const LinkageSpecDecl *LSD = 15889 FnDecl->getDeclContext()->getExternCContext()) 15890 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here); 15891 return true; 15892 } 15893 15894 // This might be the definition of a literal operator template. 15895 FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate(); 15896 15897 // This might be a specialization of a literal operator template. 15898 if (!TpDecl) 15899 TpDecl = FnDecl->getPrimaryTemplate(); 15900 15901 // template <char...> type operator "" name() and 15902 // template <class T, T...> type operator "" name() are the only valid 15903 // template signatures, and the only valid signatures with no parameters. 15904 // 15905 // C++20 also allows template <SomeClass T> type operator "" name(). 15906 if (TpDecl) { 15907 if (FnDecl->param_size() != 0) { 15908 Diag(FnDecl->getLocation(), 15909 diag::err_literal_operator_template_with_params); 15910 return true; 15911 } 15912 15913 if (checkLiteralOperatorTemplateParameterList(*this, TpDecl)) 15914 return true; 15915 15916 } else if (FnDecl->param_size() == 1) { 15917 const ParmVarDecl *Param = FnDecl->getParamDecl(0); 15918 15919 QualType ParamType = Param->getType().getUnqualifiedType(); 15920 15921 // Only unsigned long long int, long double, any character type, and const 15922 // char * are allowed as the only parameters. 15923 if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) || 15924 ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) || 15925 Context.hasSameType(ParamType, Context.CharTy) || 15926 Context.hasSameType(ParamType, Context.WideCharTy) || 15927 Context.hasSameType(ParamType, Context.Char8Ty) || 15928 Context.hasSameType(ParamType, Context.Char16Ty) || 15929 Context.hasSameType(ParamType, Context.Char32Ty)) { 15930 } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) { 15931 QualType InnerType = Ptr->getPointeeType(); 15932 15933 // Pointer parameter must be a const char *. 15934 if (!(Context.hasSameType(InnerType.getUnqualifiedType(), 15935 Context.CharTy) && 15936 InnerType.isConstQualified() && !InnerType.isVolatileQualified())) { 15937 Diag(Param->getSourceRange().getBegin(), 15938 diag::err_literal_operator_param) 15939 << ParamType << "'const char *'" << Param->getSourceRange(); 15940 return true; 15941 } 15942 15943 } else if (ParamType->isRealFloatingType()) { 15944 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param) 15945 << ParamType << Context.LongDoubleTy << Param->getSourceRange(); 15946 return true; 15947 15948 } else if (ParamType->isIntegerType()) { 15949 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param) 15950 << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange(); 15951 return true; 15952 15953 } else { 15954 Diag(Param->getSourceRange().getBegin(), 15955 diag::err_literal_operator_invalid_param) 15956 << ParamType << Param->getSourceRange(); 15957 return true; 15958 } 15959 15960 } else if (FnDecl->param_size() == 2) { 15961 FunctionDecl::param_iterator Param = FnDecl->param_begin(); 15962 15963 // First, verify that the first parameter is correct. 15964 15965 QualType FirstParamType = (*Param)->getType().getUnqualifiedType(); 15966 15967 // Two parameter function must have a pointer to const as a 15968 // first parameter; let's strip those qualifiers. 15969 const PointerType *PT = FirstParamType->getAs<PointerType>(); 15970 15971 if (!PT) { 15972 Diag((*Param)->getSourceRange().getBegin(), 15973 diag::err_literal_operator_param) 15974 << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); 15975 return true; 15976 } 15977 15978 QualType PointeeType = PT->getPointeeType(); 15979 // First parameter must be const 15980 if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) { 15981 Diag((*Param)->getSourceRange().getBegin(), 15982 diag::err_literal_operator_param) 15983 << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); 15984 return true; 15985 } 15986 15987 QualType InnerType = PointeeType.getUnqualifiedType(); 15988 // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and 15989 // const char32_t* are allowed as the first parameter to a two-parameter 15990 // function 15991 if (!(Context.hasSameType(InnerType, Context.CharTy) || 15992 Context.hasSameType(InnerType, Context.WideCharTy) || 15993 Context.hasSameType(InnerType, Context.Char8Ty) || 15994 Context.hasSameType(InnerType, Context.Char16Ty) || 15995 Context.hasSameType(InnerType, Context.Char32Ty))) { 15996 Diag((*Param)->getSourceRange().getBegin(), 15997 diag::err_literal_operator_param) 15998 << FirstParamType << "'const char *'" << (*Param)->getSourceRange(); 15999 return true; 16000 } 16001 16002 // Move on to the second and final parameter. 16003 ++Param; 16004 16005 // The second parameter must be a std::size_t. 16006 QualType SecondParamType = (*Param)->getType().getUnqualifiedType(); 16007 if (!Context.hasSameType(SecondParamType, Context.getSizeType())) { 16008 Diag((*Param)->getSourceRange().getBegin(), 16009 diag::err_literal_operator_param) 16010 << SecondParamType << Context.getSizeType() 16011 << (*Param)->getSourceRange(); 16012 return true; 16013 } 16014 } else { 16015 Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count); 16016 return true; 16017 } 16018 16019 // Parameters are good. 16020 16021 // A parameter-declaration-clause containing a default argument is not 16022 // equivalent to any of the permitted forms. 16023 for (auto Param : FnDecl->parameters()) { 16024 if (Param->hasDefaultArg()) { 16025 Diag(Param->getDefaultArgRange().getBegin(), 16026 diag::err_literal_operator_default_argument) 16027 << Param->getDefaultArgRange(); 16028 break; 16029 } 16030 } 16031 16032 StringRef LiteralName 16033 = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName(); 16034 if (LiteralName[0] != '_' && 16035 !getSourceManager().isInSystemHeader(FnDecl->getLocation())) { 16036 // C++11 [usrlit.suffix]p1: 16037 // Literal suffix identifiers that do not start with an underscore 16038 // are reserved for future standardization. 16039 Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved) 16040 << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName); 16041 } 16042 16043 return false; 16044} 16045 16046/// ActOnStartLinkageSpecification - Parsed the beginning of a C++ 16047/// linkage specification, including the language and (if present) 16048/// the '{'. ExternLoc is the location of the 'extern', Lang is the 16049/// language string literal. LBraceLoc, if valid, provides the location of 16050/// the '{' brace. Otherwise, this linkage specification does not 16051/// have any braces. 16052Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc, 16053 Expr *LangStr, 16054 SourceLocation LBraceLoc) { 16055 StringLiteral *Lit = cast<StringLiteral>(LangStr); 16056 if (!Lit->isAscii()) { 16057 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii) 16058 << LangStr->getSourceRange(); 16059 return nullptr; 16060 } 16061 16062 StringRef Lang = Lit->getString(); 16063 LinkageSpecDecl::LanguageIDs Language; 16064 if (Lang == "C") 16065 Language = LinkageSpecDecl::lang_c; 16066 else if (Lang == "C++") 16067 Language = LinkageSpecDecl::lang_cxx; 16068 else { 16069 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown) 16070 << LangStr->getSourceRange(); 16071 return nullptr; 16072 } 16073 16074 // FIXME: Add all the various semantics of linkage specifications 16075 16076 LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc, 16077 LangStr->getExprLoc(), Language, 16078 LBraceLoc.isValid()); 16079 CurContext->addDecl(D); 16080 PushDeclContext(S, D); 16081 return D; 16082} 16083 16084/// ActOnFinishLinkageSpecification - Complete the definition of 16085/// the C++ linkage specification LinkageSpec. If RBraceLoc is 16086/// valid, it's the position of the closing '}' brace in a linkage 16087/// specification that uses braces. 16088Decl *Sema::ActOnFinishLinkageSpecification(Scope *S, 16089 Decl *LinkageSpec, 16090 SourceLocation RBraceLoc) { 16091 if (RBraceLoc.isValid()) { 16092 LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec); 16093 LSDecl->setRBraceLoc(RBraceLoc); 16094 } 16095 PopDeclContext(); 16096 return LinkageSpec; 16097} 16098 16099Decl *Sema::ActOnEmptyDeclaration(Scope *S, 16100 const ParsedAttributesView &AttrList, 16101 SourceLocation SemiLoc) { 16102 Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc); 16103 // Attribute declarations appertain to empty declaration so we handle 16104 // them here. 16105 ProcessDeclAttributeList(S, ED, AttrList); 16106 16107 CurContext->addDecl(ED); 16108 return ED; 16109} 16110 16111/// Perform semantic analysis for the variable declaration that 16112/// occurs within a C++ catch clause, returning the newly-created 16113/// variable. 16114VarDecl *Sema::BuildExceptionDeclaration(Scope *S, 16115 TypeSourceInfo *TInfo, 16116 SourceLocation StartLoc, 16117 SourceLocation Loc, 16118 IdentifierInfo *Name) { 16119 bool Invalid = false; 16120 QualType ExDeclType = TInfo->getType(); 16121 16122 // Arrays and functions decay. 16123 if (ExDeclType->isArrayType()) 16124 ExDeclType = Context.getArrayDecayedType(ExDeclType); 16125 else if (ExDeclType->isFunctionType()) 16126 ExDeclType = Context.getPointerType(ExDeclType); 16127 16128 // C++ 15.3p1: The exception-declaration shall not denote an incomplete type. 16129 // The exception-declaration shall not denote a pointer or reference to an 16130 // incomplete type, other than [cv] void*. 16131 // N2844 forbids rvalue references. 16132 if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) { 16133 Diag(Loc, diag::err_catch_rvalue_ref); 16134 Invalid = true; 16135 } 16136 16137 if (ExDeclType->isVariablyModifiedType()) { 16138 Diag(Loc, diag::err_catch_variably_modified) << ExDeclType; 16139 Invalid = true; 16140 } 16141 16142 QualType BaseType = ExDeclType; 16143 int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference 16144 unsigned DK = diag::err_catch_incomplete; 16145 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { 16146 BaseType = Ptr->getPointeeType(); 16147 Mode = 1; 16148 DK = diag::err_catch_incomplete_ptr; 16149 } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) { 16150 // For the purpose of error recovery, we treat rvalue refs like lvalue refs. 16151 BaseType = Ref->getPointeeType(); 16152 Mode = 2; 16153 DK = diag::err_catch_incomplete_ref; 16154 } 16155 if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) && 16156 !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK)) 16157 Invalid = true; 16158 16159 if (!Invalid && Mode != 1 && BaseType->isSizelessType()) { 16160 Diag(Loc, diag::err_catch_sizeless) << (Mode == 2 ? 1 : 0) << BaseType; 16161 Invalid = true; 16162 } 16163 16164 if (!Invalid && !ExDeclType->isDependentType() && 16165 RequireNonAbstractType(Loc, ExDeclType, 16166 diag::err_abstract_type_in_decl, 16167 AbstractVariableType)) 16168 Invalid = true; 16169 16170 // Only the non-fragile NeXT runtime currently supports C++ catches 16171 // of ObjC types, and no runtime supports catching ObjC types by value. 16172 if (!Invalid && getLangOpts().ObjC) { 16173 QualType T = ExDeclType; 16174 if (const ReferenceType *RT = T->getAs<ReferenceType>()) 16175 T = RT->getPointeeType(); 16176 16177 if (T->isObjCObjectType()) { 16178 Diag(Loc, diag::err_objc_object_catch); 16179 Invalid = true; 16180 } else if (T->isObjCObjectPointerType()) { 16181 // FIXME: should this be a test for macosx-fragile specifically? 16182 if (getLangOpts().ObjCRuntime.isFragile()) 16183 Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile); 16184 } 16185 } 16186 16187 VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name, 16188 ExDeclType, TInfo, SC_None); 16189 ExDecl->setExceptionVariable(true); 16190 16191 // In ARC, infer 'retaining' for variables of retainable type. 16192 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl)) 16193 Invalid = true; 16194 16195 if (!Invalid && !ExDeclType->isDependentType()) { 16196 if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) { 16197 // Insulate this from anything else we might currently be parsing. 16198 EnterExpressionEvaluationContext scope( 16199 *this, ExpressionEvaluationContext::PotentiallyEvaluated); 16200 16201 // C++ [except.handle]p16: 16202 // The object declared in an exception-declaration or, if the 16203 // exception-declaration does not specify a name, a temporary (12.2) is 16204 // copy-initialized (8.5) from the exception object. [...] 16205 // The object is destroyed when the handler exits, after the destruction 16206 // of any automatic objects initialized within the handler. 16207 // 16208 // We just pretend to initialize the object with itself, then make sure 16209 // it can be destroyed later. 16210 QualType initType = Context.getExceptionObjectType(ExDeclType); 16211 16212 InitializedEntity entity = 16213 InitializedEntity::InitializeVariable(ExDecl); 16214 InitializationKind initKind = 16215 InitializationKind::CreateCopy(Loc, SourceLocation()); 16216 16217 Expr *opaqueValue = 16218 new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary); 16219 InitializationSequence sequence(*this, entity, initKind, opaqueValue); 16220 ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue); 16221 if (result.isInvalid()) 16222 Invalid = true; 16223 else { 16224 // If the constructor used was non-trivial, set this as the 16225 // "initializer". 16226 CXXConstructExpr *construct = result.getAs<CXXConstructExpr>(); 16227 if (!construct->getConstructor()->isTrivial()) { 16228 Expr *init = MaybeCreateExprWithCleanups(construct); 16229 ExDecl->setInit(init); 16230 } 16231 16232 // And make sure it's destructable. 16233 FinalizeVarWithDestructor(ExDecl, recordType); 16234 } 16235 } 16236 } 16237 16238 if (Invalid) 16239 ExDecl->setInvalidDecl(); 16240 16241 return ExDecl; 16242} 16243 16244/// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch 16245/// handler. 16246Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) { 16247 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 16248 bool Invalid = D.isInvalidType(); 16249 16250 // Check for unexpanded parameter packs. 16251 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, 16252 UPPC_ExceptionType)) { 16253 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy, 16254 D.getIdentifierLoc()); 16255 Invalid = true; 16256 } 16257 16258 IdentifierInfo *II = D.getIdentifier(); 16259 if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(), 16260 LookupOrdinaryName, 16261 ForVisibleRedeclaration)) { 16262 // The scope should be freshly made just for us. There is just no way 16263 // it contains any previous declaration, except for function parameters in 16264 // a function-try-block's catch statement. 16265 assert(!S->isDeclScope(PrevDecl))((void)0); 16266 if (isDeclInScope(PrevDecl, CurContext, S)) { 16267 Diag(D.getIdentifierLoc(), diag::err_redefinition) 16268 << D.getIdentifier(); 16269 Diag(PrevDecl->getLocation(), diag::note_previous_definition); 16270 Invalid = true; 16271 } else if (PrevDecl->isTemplateParameter()) 16272 // Maybe we will complain about the shadowed template parameter. 16273 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 16274 } 16275 16276 if (D.getCXXScopeSpec().isSet() && !Invalid) { 16277 Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator) 16278 << D.getCXXScopeSpec().getRange(); 16279 Invalid = true; 16280 } 16281 16282 VarDecl *ExDecl = BuildExceptionDeclaration( 16283 S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier()); 16284 if (Invalid) 16285 ExDecl->setInvalidDecl(); 16286 16287 // Add the exception declaration into this scope. 16288 if (II) 16289 PushOnScopeChains(ExDecl, S); 16290 else 16291 CurContext->addDecl(ExDecl); 16292 16293 ProcessDeclAttributes(S, ExDecl, D); 16294 return ExDecl; 16295} 16296 16297Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc, 16298 Expr *AssertExpr, 16299 Expr *AssertMessageExpr, 16300 SourceLocation RParenLoc) { 16301 StringLiteral *AssertMessage = 16302 AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr; 16303 16304 if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression)) 16305 return nullptr; 16306 16307 return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr, 16308 AssertMessage, RParenLoc, false); 16309} 16310 16311Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc, 16312 Expr *AssertExpr, 16313 StringLiteral *AssertMessage, 16314 SourceLocation RParenLoc, 16315 bool Failed) { 16316 assert(AssertExpr != nullptr && "Expected non-null condition")((void)0); 16317 if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() && 16318 !Failed) { 16319 // In a static_assert-declaration, the constant-expression shall be a 16320 // constant expression that can be contextually converted to bool. 16321 ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr); 16322 if (Converted.isInvalid()) 16323 Failed = true; 16324 16325 ExprResult FullAssertExpr = 16326 ActOnFinishFullExpr(Converted.get(), StaticAssertLoc, 16327 /*DiscardedValue*/ false, 16328 /*IsConstexpr*/ true); 16329 if (FullAssertExpr.isInvalid()) 16330 Failed = true; 16331 else 16332 AssertExpr = FullAssertExpr.get(); 16333 16334 llvm::APSInt Cond; 16335 if (!Failed && VerifyIntegerConstantExpression( 16336 AssertExpr, &Cond, 16337 diag::err_static_assert_expression_is_not_constant) 16338 .isInvalid()) 16339 Failed = true; 16340 16341 if (!Failed && !Cond) { 16342 SmallString<256> MsgBuffer; 16343 llvm::raw_svector_ostream Msg(MsgBuffer); 16344 if (AssertMessage) 16345 AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy()); 16346 16347 Expr *InnerCond = nullptr; 16348 std::string InnerCondDescription; 16349 std::tie(InnerCond, InnerCondDescription) = 16350 findFailedBooleanCondition(Converted.get()); 16351 if (InnerCond && isa<ConceptSpecializationExpr>(InnerCond)) { 16352 // Drill down into concept specialization expressions to see why they 16353 // weren't satisfied. 16354 Diag(StaticAssertLoc, diag::err_static_assert_failed) 16355 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange(); 16356 ConstraintSatisfaction Satisfaction; 16357 if (!CheckConstraintSatisfaction(InnerCond, Satisfaction)) 16358 DiagnoseUnsatisfiedConstraint(Satisfaction); 16359 } else if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond) 16360 && !isa<IntegerLiteral>(InnerCond)) { 16361 Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed) 16362 << InnerCondDescription << !AssertMessage 16363 << Msg.str() << InnerCond->getSourceRange(); 16364 } else { 16365 Diag(StaticAssertLoc, diag::err_static_assert_failed) 16366 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange(); 16367 } 16368 Failed = true; 16369 } 16370 } else { 16371 ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc, 16372 /*DiscardedValue*/false, 16373 /*IsConstexpr*/true); 16374 if (FullAssertExpr.isInvalid()) 16375 Failed = true; 16376 else 16377 AssertExpr = FullAssertExpr.get(); 16378 } 16379 16380 Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc, 16381 AssertExpr, AssertMessage, RParenLoc, 16382 Failed); 16383 16384 CurContext->addDecl(Decl); 16385 return Decl; 16386} 16387 16388/// Perform semantic analysis of the given friend type declaration. 16389/// 16390/// \returns A friend declaration that. 16391FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart, 16392 SourceLocation FriendLoc, 16393 TypeSourceInfo *TSInfo) { 16394 assert(TSInfo && "NULL TypeSourceInfo for friend type declaration")((void)0); 16395 16396 QualType T = TSInfo->getType(); 16397 SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange(); 16398 16399 // C++03 [class.friend]p2: 16400 // An elaborated-type-specifier shall be used in a friend declaration 16401 // for a class.* 16402 // 16403 // * The class-key of the elaborated-type-specifier is required. 16404 if (!CodeSynthesisContexts.empty()) { 16405 // Do not complain about the form of friend template types during any kind 16406 // of code synthesis. For template instantiation, we will have complained 16407 // when the template was defined. 16408 } else { 16409 if (!T->isElaboratedTypeSpecifier()) { 16410 // If we evaluated the type to a record type, suggest putting 16411 // a tag in front. 16412 if (const RecordType *RT = T->getAs<RecordType>()) { 16413 RecordDecl *RD = RT->getDecl(); 16414 16415 SmallString<16> InsertionText(" "); 16416 InsertionText += RD->getKindName(); 16417 16418 Diag(TypeRange.getBegin(), 16419 getLangOpts().CPlusPlus11 ? 16420 diag::warn_cxx98_compat_unelaborated_friend_type : 16421 diag::ext_unelaborated_friend_type) 16422 << (unsigned) RD->getTagKind() 16423 << T 16424 << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc), 16425 InsertionText); 16426 } else { 16427 Diag(FriendLoc, 16428 getLangOpts().CPlusPlus11 ? 16429 diag::warn_cxx98_compat_nonclass_type_friend : 16430 diag::ext_nonclass_type_friend) 16431 << T 16432 << TypeRange; 16433 } 16434 } else if (T->getAs<EnumType>()) { 16435 Diag(FriendLoc, 16436 getLangOpts().CPlusPlus11 ? 16437 diag::warn_cxx98_compat_enum_friend : 16438 diag::ext_enum_friend) 16439 << T 16440 << TypeRange; 16441 } 16442 16443 // C++11 [class.friend]p3: 16444 // A friend declaration that does not declare a function shall have one 16445 // of the following forms: 16446 // friend elaborated-type-specifier ; 16447 // friend simple-type-specifier ; 16448 // friend typename-specifier ; 16449 if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc) 16450 Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T; 16451 } 16452 16453 // If the type specifier in a friend declaration designates a (possibly 16454 // cv-qualified) class type, that class is declared as a friend; otherwise, 16455 // the friend declaration is ignored. 16456 return FriendDecl::Create(Context, CurContext, 16457 TSInfo->getTypeLoc().getBeginLoc(), TSInfo, 16458 FriendLoc); 16459} 16460 16461/// Handle a friend tag declaration where the scope specifier was 16462/// templated. 16463Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc, 16464 unsigned TagSpec, SourceLocation TagLoc, 16465 CXXScopeSpec &SS, IdentifierInfo *Name, 16466 SourceLocation NameLoc, 16467 const ParsedAttributesView &Attr, 16468 MultiTemplateParamsArg TempParamLists) { 16469 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); 16470 16471 bool IsMemberSpecialization = false; 16472 bool Invalid = false; 16473 16474 if (TemplateParameterList *TemplateParams = 16475 MatchTemplateParametersToScopeSpecifier( 16476 TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true, 16477 IsMemberSpecialization, Invalid)) { 16478 if (TemplateParams->size() > 0) { 16479 // This is a declaration of a class template. 16480 if (Invalid) 16481 return nullptr; 16482 16483 return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name, 16484 NameLoc, Attr, TemplateParams, AS_public, 16485 /*ModulePrivateLoc=*/SourceLocation(), 16486 FriendLoc, TempParamLists.size() - 1, 16487 TempParamLists.data()).get(); 16488 } else { 16489 // The "template<>" header is extraneous. 16490 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams) 16491 << TypeWithKeyword::getTagTypeKindName(Kind) << Name; 16492 IsMemberSpecialization = true; 16493 } 16494 } 16495 16496 if (Invalid) return nullptr; 16497 16498 bool isAllExplicitSpecializations = true; 16499 for (unsigned I = TempParamLists.size(); I-- > 0; ) { 16500 if (TempParamLists[I]->size()) { 16501 isAllExplicitSpecializations = false; 16502 break; 16503 } 16504 } 16505 16506 // FIXME: don't ignore attributes. 16507 16508 // If it's explicit specializations all the way down, just forget 16509 // about the template header and build an appropriate non-templated 16510 // friend. TODO: for source fidelity, remember the headers. 16511 if (isAllExplicitSpecializations) { 16512 if (SS.isEmpty()) { 16513 bool Owned = false; 16514 bool IsDependent = false; 16515 return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc, 16516 Attr, AS_public, 16517 /*ModulePrivateLoc=*/SourceLocation(), 16518 MultiTemplateParamsArg(), Owned, IsDependent, 16519 /*ScopedEnumKWLoc=*/SourceLocation(), 16520 /*ScopedEnumUsesClassTag=*/false, 16521 /*UnderlyingType=*/TypeResult(), 16522 /*IsTypeSpecifier=*/false, 16523 /*IsTemplateParamOrArg=*/false); 16524 } 16525 16526 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context); 16527 ElaboratedTypeKeyword Keyword 16528 = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 16529 QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc, 16530 *Name, NameLoc); 16531 if (T.isNull()) 16532 return nullptr; 16533 16534 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 16535 if (isa<DependentNameType>(T)) { 16536 DependentNameTypeLoc TL = 16537 TSI->getTypeLoc().castAs<DependentNameTypeLoc>(); 16538 TL.setElaboratedKeywordLoc(TagLoc); 16539 TL.setQualifierLoc(QualifierLoc); 16540 TL.setNameLoc(NameLoc); 16541 } else { 16542 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>(); 16543 TL.setElaboratedKeywordLoc(TagLoc); 16544 TL.setQualifierLoc(QualifierLoc); 16545 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc); 16546 } 16547 16548 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, 16549 TSI, FriendLoc, TempParamLists); 16550 Friend->setAccess(AS_public); 16551 CurContext->addDecl(Friend); 16552 return Friend; 16553 } 16554 16555 assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?")((void)0); 16556 16557 16558 16559 // Handle the case of a templated-scope friend class. e.g. 16560 // template <class T> class A<T>::B; 16561 // FIXME: we don't support these right now. 16562 Diag(NameLoc, diag::warn_template_qualified_friend_unsupported) 16563 << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext); 16564 ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind); 16565 QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name); 16566 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T); 16567 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>(); 16568 TL.setElaboratedKeywordLoc(TagLoc); 16569 TL.setQualifierLoc(SS.getWithLocInContext(Context)); 16570 TL.setNameLoc(NameLoc); 16571 16572 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc, 16573 TSI, FriendLoc, TempParamLists); 16574 Friend->setAccess(AS_public); 16575 Friend->setUnsupportedFriend(true); 16576 CurContext->addDecl(Friend); 16577 return Friend; 16578} 16579 16580/// Handle a friend type declaration. This works in tandem with 16581/// ActOnTag. 16582/// 16583/// Notes on friend class templates: 16584/// 16585/// We generally treat friend class declarations as if they were 16586/// declaring a class. So, for example, the elaborated type specifier 16587/// in a friend declaration is required to obey the restrictions of a 16588/// class-head (i.e. no typedefs in the scope chain), template 16589/// parameters are required to match up with simple template-ids, &c. 16590/// However, unlike when declaring a template specialization, it's 16591/// okay to refer to a template specialization without an empty 16592/// template parameter declaration, e.g. 16593/// friend class A<T>::B<unsigned>; 16594/// We permit this as a special case; if there are any template 16595/// parameters present at all, require proper matching, i.e. 16596/// template <> template \<class T> friend class A<int>::B; 16597Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS, 16598 MultiTemplateParamsArg TempParams) { 16599 SourceLocation Loc = DS.getBeginLoc(); 16600 16601 assert(DS.isFriendSpecified())((void)0); 16602 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)((void)0); 16603 16604 // C++ [class.friend]p3: 16605 // A friend declaration that does not declare a function shall have one of 16606 // the following forms: 16607 // friend elaborated-type-specifier ; 16608 // friend simple-type-specifier ; 16609 // friend typename-specifier ; 16610 // 16611 // Any declaration with a type qualifier does not have that form. (It's 16612 // legal to specify a qualified type as a friend, you just can't write the 16613 // keywords.) 16614 if (DS.getTypeQualifiers()) { 16615 if (DS.getTypeQualifiers() & DeclSpec::TQ_const) 16616 Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const"; 16617 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile) 16618 Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile"; 16619 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict) 16620 Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict"; 16621 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic) 16622 Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic"; 16623 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned) 16624 Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned"; 16625 } 16626 16627 // Try to convert the decl specifier to a type. This works for 16628 // friend templates because ActOnTag never produces a ClassTemplateDecl 16629 // for a TUK_Friend. 16630 Declarator TheDeclarator(DS, DeclaratorContext::Member); 16631 TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S); 16632 QualType T = TSI->getType(); 16633 if (TheDeclarator.isInvalidType()) 16634 return nullptr; 16635 16636 if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration)) 16637 return nullptr; 16638 16639 // This is definitely an error in C++98. It's probably meant to 16640 // be forbidden in C++0x, too, but the specification is just 16641 // poorly written. 16642 // 16643 // The problem is with declarations like the following: 16644 // template <T> friend A<T>::foo; 16645 // where deciding whether a class C is a friend or not now hinges 16646 // on whether there exists an instantiation of A that causes 16647 // 'foo' to equal C. There are restrictions on class-heads 16648 // (which we declare (by fiat) elaborated friend declarations to 16649 // be) that makes this tractable. 16650 // 16651 // FIXME: handle "template <> friend class A<T>;", which 16652 // is possibly well-formed? Who even knows? 16653 if (TempParams.size() && !T->isElaboratedTypeSpecifier()) { 16654 Diag(Loc, diag::err_tagless_friend_type_template) 16655 << DS.getSourceRange(); 16656 return nullptr; 16657 } 16658 16659 // C++98 [class.friend]p1: A friend of a class is a function 16660 // or class that is not a member of the class . . . 16661 // This is fixed in DR77, which just barely didn't make the C++03 16662 // deadline. It's also a very silly restriction that seriously 16663 // affects inner classes and which nobody else seems to implement; 16664 // thus we never diagnose it, not even in -pedantic. 16665 // 16666 // But note that we could warn about it: it's always useless to 16667 // friend one of your own members (it's not, however, worthless to 16668 // friend a member of an arbitrary specialization of your template). 16669 16670 Decl *D; 16671 if (!TempParams.empty()) 16672 D = FriendTemplateDecl::Create(Context, CurContext, Loc, 16673 TempParams, 16674 TSI, 16675 DS.getFriendSpecLoc()); 16676 else 16677 D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI); 16678 16679 if (!D) 16680 return nullptr; 16681 16682 D->setAccess(AS_public); 16683 CurContext->addDecl(D); 16684 16685 return D; 16686} 16687 16688NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D, 16689 MultiTemplateParamsArg TemplateParams) { 16690 const DeclSpec &DS = D.getDeclSpec(); 16691 16692 assert(DS.isFriendSpecified())((void)0); 16693 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified)((void)0); 16694 16695 SourceLocation Loc = D.getIdentifierLoc(); 16696 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 16697 16698 // C++ [class.friend]p1 16699 // A friend of a class is a function or class.... 16700 // Note that this sees through typedefs, which is intended. 16701 // It *doesn't* see through dependent types, which is correct 16702 // according to [temp.arg.type]p3: 16703 // If a declaration acquires a function type through a 16704 // type dependent on a template-parameter and this causes 16705 // a declaration that does not use the syntactic form of a 16706 // function declarator to have a function type, the program 16707 // is ill-formed. 16708 if (!TInfo->getType()->isFunctionType()) { 16709 Diag(Loc, diag::err_unexpected_friend); 16710 16711 // It might be worthwhile to try to recover by creating an 16712 // appropriate declaration. 16713 return nullptr; 16714 } 16715 16716 // C++ [namespace.memdef]p3 16717 // - If a friend declaration in a non-local class first declares a 16718 // class or function, the friend class or function is a member 16719 // of the innermost enclosing namespace. 16720 // - The name of the friend is not found by simple name lookup 16721 // until a matching declaration is provided in that namespace 16722 // scope (either before or after the class declaration granting 16723 // friendship). 16724 // - If a friend function is called, its name may be found by the 16725 // name lookup that considers functions from namespaces and 16726 // classes associated with the types of the function arguments. 16727 // - When looking for a prior declaration of a class or a function 16728 // declared as a friend, scopes outside the innermost enclosing 16729 // namespace scope are not considered. 16730 16731 CXXScopeSpec &SS = D.getCXXScopeSpec(); 16732 DeclarationNameInfo NameInfo = GetNameForDeclarator(D); 16733 assert(NameInfo.getName())((void)0); 16734 16735 // Check for unexpanded parameter packs. 16736 if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) || 16737 DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) || 16738 DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration)) 16739 return nullptr; 16740 16741 // The context we found the declaration in, or in which we should 16742 // create the declaration. 16743 DeclContext *DC; 16744 Scope *DCScope = S; 16745 LookupResult Previous(*this, NameInfo, LookupOrdinaryName, 16746 ForExternalRedeclaration); 16747 16748 // There are five cases here. 16749 // - There's no scope specifier and we're in a local class. Only look 16750 // for functions declared in the immediately-enclosing block scope. 16751 // We recover from invalid scope qualifiers as if they just weren't there. 16752 FunctionDecl *FunctionContainingLocalClass = nullptr; 16753 if ((SS.isInvalid() || !SS.isSet()) && 16754 (FunctionContainingLocalClass = 16755 cast<CXXRecordDecl>(CurContext)->isLocalClass())) { 16756 // C++11 [class.friend]p11: 16757 // If a friend declaration appears in a local class and the name 16758 // specified is an unqualified name, a prior declaration is 16759 // looked up without considering scopes that are outside the 16760 // innermost enclosing non-class scope. For a friend function 16761 // declaration, if there is no prior declaration, the program is 16762 // ill-formed. 16763 16764 // Find the innermost enclosing non-class scope. This is the block 16765 // scope containing the local class definition (or for a nested class, 16766 // the outer local class). 16767 DCScope = S->getFnParent(); 16768 16769 // Look up the function name in the scope. 16770 Previous.clear(LookupLocalFriendName); 16771 LookupName(Previous, S, /*AllowBuiltinCreation*/false); 16772 16773 if (!Previous.empty()) { 16774 // All possible previous declarations must have the same context: 16775 // either they were declared at block scope or they are members of 16776 // one of the enclosing local classes. 16777 DC = Previous.getRepresentativeDecl()->getDeclContext(); 16778 } else { 16779 // This is ill-formed, but provide the context that we would have 16780 // declared the function in, if we were permitted to, for error recovery. 16781 DC = FunctionContainingLocalClass; 16782 } 16783 adjustContextForLocalExternDecl(DC); 16784 16785 // C++ [class.friend]p6: 16786 // A function can be defined in a friend declaration of a class if and 16787 // only if the class is a non-local class (9.8), the function name is 16788 // unqualified, and the function has namespace scope. 16789 if (D.isFunctionDefinition()) { 16790 Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class); 16791 } 16792 16793 // - There's no scope specifier, in which case we just go to the 16794 // appropriate scope and look for a function or function template 16795 // there as appropriate. 16796 } else if (SS.isInvalid() || !SS.isSet()) { 16797 // C++11 [namespace.memdef]p3: 16798 // If the name in a friend declaration is neither qualified nor 16799 // a template-id and the declaration is a function or an 16800 // elaborated-type-specifier, the lookup to determine whether 16801 // the entity has been previously declared shall not consider 16802 // any scopes outside the innermost enclosing namespace. 16803 bool isTemplateId = 16804 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId; 16805 16806 // Find the appropriate context according to the above. 16807 DC = CurContext; 16808 16809 // Skip class contexts. If someone can cite chapter and verse 16810 // for this behavior, that would be nice --- it's what GCC and 16811 // EDG do, and it seems like a reasonable intent, but the spec 16812 // really only says that checks for unqualified existing 16813 // declarations should stop at the nearest enclosing namespace, 16814 // not that they should only consider the nearest enclosing 16815 // namespace. 16816 while (DC->isRecord()) 16817 DC = DC->getParent(); 16818 16819 DeclContext *LookupDC = DC; 16820 while (LookupDC->isTransparentContext()) 16821 LookupDC = LookupDC->getParent(); 16822 16823 while (true) { 16824 LookupQualifiedName(Previous, LookupDC); 16825 16826 if (!Previous.empty()) { 16827 DC = LookupDC; 16828 break; 16829 } 16830 16831 if (isTemplateId) { 16832 if (isa<TranslationUnitDecl>(LookupDC)) break; 16833 } else { 16834 if (LookupDC->isFileContext()) break; 16835 } 16836 LookupDC = LookupDC->getParent(); 16837 } 16838 16839 DCScope = getScopeForDeclContext(S, DC); 16840 16841 // - There's a non-dependent scope specifier, in which case we 16842 // compute it and do a previous lookup there for a function 16843 // or function template. 16844 } else if (!SS.getScopeRep()->isDependent()) { 16845 DC = computeDeclContext(SS); 16846 if (!DC) return nullptr; 16847 16848 if (RequireCompleteDeclContext(SS, DC)) return nullptr; 16849 16850 LookupQualifiedName(Previous, DC); 16851 16852 // C++ [class.friend]p1: A friend of a class is a function or 16853 // class that is not a member of the class . . . 16854 if (DC->Equals(CurContext)) 16855 Diag(DS.getFriendSpecLoc(), 16856 getLangOpts().CPlusPlus11 ? 16857 diag::warn_cxx98_compat_friend_is_member : 16858 diag::err_friend_is_member); 16859 16860 if (D.isFunctionDefinition()) { 16861 // C++ [class.friend]p6: 16862 // A function can be defined in a friend declaration of a class if and 16863 // only if the class is a non-local class (9.8), the function name is 16864 // unqualified, and the function has namespace scope. 16865 // 16866 // FIXME: We should only do this if the scope specifier names the 16867 // innermost enclosing namespace; otherwise the fixit changes the 16868 // meaning of the code. 16869 SemaDiagnosticBuilder DB 16870 = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def); 16871 16872 DB << SS.getScopeRep(); 16873 if (DC->isFileContext()) 16874 DB << FixItHint::CreateRemoval(SS.getRange()); 16875 SS.clear(); 16876 } 16877 16878 // - There's a scope specifier that does not match any template 16879 // parameter lists, in which case we use some arbitrary context, 16880 // create a method or method template, and wait for instantiation. 16881 // - There's a scope specifier that does match some template 16882 // parameter lists, which we don't handle right now. 16883 } else { 16884 if (D.isFunctionDefinition()) { 16885 // C++ [class.friend]p6: 16886 // A function can be defined in a friend declaration of a class if and 16887 // only if the class is a non-local class (9.8), the function name is 16888 // unqualified, and the function has namespace scope. 16889 Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def) 16890 << SS.getScopeRep(); 16891 } 16892 16893 DC = CurContext; 16894 assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?")((void)0); 16895 } 16896 16897 if (!DC->isRecord()) { 16898 int DiagArg = -1; 16899 switch (D.getName().getKind()) { 16900 case UnqualifiedIdKind::IK_ConstructorTemplateId: 16901 case UnqualifiedIdKind::IK_ConstructorName: 16902 DiagArg = 0; 16903 break; 16904 case UnqualifiedIdKind::IK_DestructorName: 16905 DiagArg = 1; 16906 break; 16907 case UnqualifiedIdKind::IK_ConversionFunctionId: 16908 DiagArg = 2; 16909 break; 16910 case UnqualifiedIdKind::IK_DeductionGuideName: 16911 DiagArg = 3; 16912 break; 16913 case UnqualifiedIdKind::IK_Identifier: 16914 case UnqualifiedIdKind::IK_ImplicitSelfParam: 16915 case UnqualifiedIdKind::IK_LiteralOperatorId: 16916 case UnqualifiedIdKind::IK_OperatorFunctionId: 16917 case UnqualifiedIdKind::IK_TemplateId: 16918 break; 16919 } 16920 // This implies that it has to be an operator or function. 16921 if (DiagArg >= 0) { 16922 Diag(Loc, diag::err_introducing_special_friend) << DiagArg; 16923 return nullptr; 16924 } 16925 } 16926 16927 // FIXME: This is an egregious hack to cope with cases where the scope stack 16928 // does not contain the declaration context, i.e., in an out-of-line 16929 // definition of a class. 16930 Scope FakeDCScope(S, Scope::DeclScope, Diags); 16931 if (!DCScope) { 16932 FakeDCScope.setEntity(DC); 16933 DCScope = &FakeDCScope; 16934 } 16935 16936 bool AddToScope = true; 16937 NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous, 16938 TemplateParams, AddToScope); 16939 if (!ND) return nullptr; 16940 16941 assert(ND->getLexicalDeclContext() == CurContext)((void)0); 16942 16943 // If we performed typo correction, we might have added a scope specifier 16944 // and changed the decl context. 16945 DC = ND->getDeclContext(); 16946 16947 // Add the function declaration to the appropriate lookup tables, 16948 // adjusting the redeclarations list as necessary. We don't 16949 // want to do this yet if the friending class is dependent. 16950 // 16951 // Also update the scope-based lookup if the target context's 16952 // lookup context is in lexical scope. 16953 if (!CurContext->isDependentContext()) { 16954 DC = DC->getRedeclContext(); 16955 DC->makeDeclVisibleInContext(ND); 16956 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) 16957 PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false); 16958 } 16959 16960 FriendDecl *FrD = FriendDecl::Create(Context, CurContext, 16961 D.getIdentifierLoc(), ND, 16962 DS.getFriendSpecLoc()); 16963 FrD->setAccess(AS_public); 16964 CurContext->addDecl(FrD); 16965 16966 if (ND->isInvalidDecl()) { 16967 FrD->setInvalidDecl(); 16968 } else { 16969 if (DC->isRecord()) CheckFriendAccess(ND); 16970 16971 FunctionDecl *FD; 16972 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 16973 FD = FTD->getTemplatedDecl(); 16974 else 16975 FD = cast<FunctionDecl>(ND); 16976 16977 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a 16978 // default argument expression, that declaration shall be a definition 16979 // and shall be the only declaration of the function or function 16980 // template in the translation unit. 16981 if (functionDeclHasDefaultArgument(FD)) { 16982 // We can't look at FD->getPreviousDecl() because it may not have been set 16983 // if we're in a dependent context. If the function is known to be a 16984 // redeclaration, we will have narrowed Previous down to the right decl. 16985 if (D.isRedeclaration()) { 16986 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared); 16987 Diag(Previous.getRepresentativeDecl()->getLocation(), 16988 diag::note_previous_declaration); 16989 } else if (!D.isFunctionDefinition()) 16990 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def); 16991 } 16992 16993 // Mark templated-scope function declarations as unsupported. 16994 if (FD->getNumTemplateParameterLists() && SS.isValid()) { 16995 Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported) 16996 << SS.getScopeRep() << SS.getRange() 16997 << cast<CXXRecordDecl>(CurContext); 16998 FrD->setUnsupportedFriend(true); 16999 } 17000 } 17001 17002 warnOnReservedIdentifier(ND); 17003 17004 return ND; 17005} 17006 17007void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) { 17008 AdjustDeclIfTemplate(Dcl); 17009 17010 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl); 17011 if (!Fn) { 17012 Diag(DelLoc, diag::err_deleted_non_function); 17013 return; 17014 } 17015 17016 // Deleted function does not have a body. 17017 Fn->setWillHaveBody(false); 17018 17019 if (const FunctionDecl *Prev = Fn->getPreviousDecl()) { 17020 // Don't consider the implicit declaration we generate for explicit 17021 // specializations. FIXME: Do not generate these implicit declarations. 17022 if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization || 17023 Prev->getPreviousDecl()) && 17024 !Prev->isDefined()) { 17025 Diag(DelLoc, diag::err_deleted_decl_not_first); 17026 Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(), 17027 Prev->isImplicit() ? diag::note_previous_implicit_declaration 17028 : diag::note_previous_declaration); 17029 // We can't recover from this; the declaration might have already 17030 // been used. 17031 Fn->setInvalidDecl(); 17032 return; 17033 } 17034 17035 // To maintain the invariant that functions are only deleted on their first 17036 // declaration, mark the implicitly-instantiated declaration of the 17037 // explicitly-specialized function as deleted instead of marking the 17038 // instantiated redeclaration. 17039 Fn = Fn->getCanonicalDecl(); 17040 } 17041 17042 // dllimport/dllexport cannot be deleted. 17043 if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) { 17044 Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr; 17045 Fn->setInvalidDecl(); 17046 } 17047 17048 // C++11 [basic.start.main]p3: 17049 // A program that defines main as deleted [...] is ill-formed. 17050 if (Fn->isMain()) 17051 Diag(DelLoc, diag::err_deleted_main); 17052 17053 // C++11 [dcl.fct.def.delete]p4: 17054 // A deleted function is implicitly inline. 17055 Fn->setImplicitlyInline(); 17056 Fn->setDeletedAsWritten(); 17057} 17058 17059void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) { 17060 if (!Dcl || Dcl->isInvalidDecl()) 17061 return; 17062 17063 auto *FD = dyn_cast<FunctionDecl>(Dcl); 17064 if (!FD) { 17065 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(Dcl)) { 17066 if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) { 17067 Diag(DefaultLoc, diag::err_defaulted_comparison_template); 17068 return; 17069 } 17070 } 17071 17072 Diag(DefaultLoc, diag::err_default_special_members) 17073 << getLangOpts().CPlusPlus20; 17074 return; 17075 } 17076 17077 // Reject if this can't possibly be a defaultable function. 17078 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD); 17079 if (!DefKind && 17080 // A dependent function that doesn't locally look defaultable can 17081 // still instantiate to a defaultable function if it's a constructor 17082 // or assignment operator. 17083 (!FD->isDependentContext() || 17084 (!isa<CXXConstructorDecl>(FD) && 17085 FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) { 17086 Diag(DefaultLoc, diag::err_default_special_members) 17087 << getLangOpts().CPlusPlus20; 17088 return; 17089 } 17090 17091 if (DefKind.isComparison() && 17092 !isa<CXXRecordDecl>(FD->getLexicalDeclContext())) { 17093 Diag(FD->getLocation(), diag::err_defaulted_comparison_out_of_class) 17094 << (int)DefKind.asComparison(); 17095 return; 17096 } 17097 17098 // Issue compatibility warning. We already warned if the operator is 17099 // 'operator<=>' when parsing the '<=>' token. 17100 if (DefKind.isComparison() && 17101 DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) { 17102 Diag(DefaultLoc, getLangOpts().CPlusPlus20 17103 ? diag::warn_cxx17_compat_defaulted_comparison 17104 : diag::ext_defaulted_comparison); 17105 } 17106 17107 FD->setDefaulted(); 17108 FD->setExplicitlyDefaulted(); 17109 17110 // Defer checking functions that are defaulted in a dependent context. 17111 if (FD->isDependentContext()) 17112 return; 17113 17114 // Unset that we will have a body for this function. We might not, 17115 // if it turns out to be trivial, and we don't need this marking now 17116 // that we've marked it as defaulted. 17117 FD->setWillHaveBody(false); 17118 17119 // If this definition appears within the record, do the checking when 17120 // the record is complete. This is always the case for a defaulted 17121 // comparison. 17122 if (DefKind.isComparison()) 17123 return; 17124 auto *MD = cast<CXXMethodDecl>(FD); 17125 17126 const FunctionDecl *Primary = FD; 17127 if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern()) 17128 // Ask the template instantiation pattern that actually had the 17129 // '= default' on it. 17130 Primary = Pattern; 17131 17132 // If the method was defaulted on its first declaration, we will have 17133 // already performed the checking in CheckCompletedCXXClass. Such a 17134 // declaration doesn't trigger an implicit definition. 17135 if (Primary->getCanonicalDecl()->isDefaulted()) 17136 return; 17137 17138 // FIXME: Once we support defining comparisons out of class, check for a 17139 // defaulted comparison here. 17140 if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember())) 17141 MD->setInvalidDecl(); 17142 else 17143 DefineDefaultedFunction(*this, MD, DefaultLoc); 17144} 17145 17146static void SearchForReturnInStmt(Sema &Self, Stmt *S) { 17147 for (Stmt *SubStmt : S->children()) { 17148 if (!SubStmt) 17149 continue; 17150 if (isa<ReturnStmt>(SubStmt)) 17151 Self.Diag(SubStmt->getBeginLoc(), 17152 diag::err_return_in_constructor_handler); 17153 if (!isa<Expr>(SubStmt)) 17154 SearchForReturnInStmt(Self, SubStmt); 17155 } 17156} 17157 17158void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) { 17159 for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) { 17160 CXXCatchStmt *Handler = TryBlock->getHandler(I); 17161 SearchForReturnInStmt(*this, Handler); 17162 } 17163} 17164 17165bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New, 17166 const CXXMethodDecl *Old) { 17167 const auto *NewFT = New->getType()->castAs<FunctionProtoType>(); 17168 const auto *OldFT = Old->getType()->castAs<FunctionProtoType>(); 17169 17170 if (OldFT->hasExtParameterInfos()) { 17171 for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I) 17172 // A parameter of the overriding method should be annotated with noescape 17173 // if the corresponding parameter of the overridden method is annotated. 17174 if (OldFT->getExtParameterInfo(I).isNoEscape() && 17175 !NewFT->getExtParameterInfo(I).isNoEscape()) { 17176 Diag(New->getParamDecl(I)->getLocation(), 17177 diag::warn_overriding_method_missing_noescape); 17178 Diag(Old->getParamDecl(I)->getLocation(), 17179 diag::note_overridden_marked_noescape); 17180 } 17181 } 17182 17183 // Virtual overrides must have the same code_seg. 17184 const auto *OldCSA = Old->getAttr<CodeSegAttr>(); 17185 const auto *NewCSA = New->getAttr<CodeSegAttr>(); 17186 if ((NewCSA || OldCSA) && 17187 (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) { 17188 Diag(New->getLocation(), diag::err_mismatched_code_seg_override); 17189 Diag(Old->getLocation(), diag::note_previous_declaration); 17190 return true; 17191 } 17192 17193 CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv(); 17194 17195 // If the calling conventions match, everything is fine 17196 if (NewCC == OldCC) 17197 return false; 17198 17199 // If the calling conventions mismatch because the new function is static, 17200 // suppress the calling convention mismatch error; the error about static 17201 // function override (err_static_overrides_virtual from 17202 // Sema::CheckFunctionDeclaration) is more clear. 17203 if (New->getStorageClass() == SC_Static) 17204 return false; 17205 17206 Diag(New->getLocation(), 17207 diag::err_conflicting_overriding_cc_attributes) 17208 << New->getDeclName() << New->getType() << Old->getType(); 17209 Diag(Old->getLocation(), diag::note_overridden_virtual_function); 17210 return true; 17211} 17212 17213bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New, 17214 const CXXMethodDecl *Old) { 17215 QualType NewTy = New->getType()->castAs<FunctionType>()->getReturnType(); 17216 QualType OldTy = Old->getType()->castAs<FunctionType>()->getReturnType(); 17217 17218 if (Context.hasSameType(NewTy, OldTy) || 17219 NewTy->isDependentType() || OldTy->isDependentType()) 17220 return false; 17221 17222 // Check if the return types are covariant 17223 QualType NewClassTy, OldClassTy; 17224 17225 /// Both types must be pointers or references to classes. 17226 if (const PointerType *NewPT = NewTy->getAs<PointerType>()) { 17227 if (const PointerType *OldPT = OldTy->getAs<PointerType>()) { 17228 NewClassTy = NewPT->getPointeeType(); 17229 OldClassTy = OldPT->getPointeeType(); 17230 } 17231 } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) { 17232 if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) { 17233 if (NewRT->getTypeClass() == OldRT->getTypeClass()) { 17234 NewClassTy = NewRT->getPointeeType(); 17235 OldClassTy = OldRT->getPointeeType(); 17236 } 17237 } 17238 } 17239 17240 // The return types aren't either both pointers or references to a class type. 17241 if (NewClassTy.isNull()) { 17242 Diag(New->getLocation(), 17243 diag::err_different_return_type_for_overriding_virtual_function) 17244 << New->getDeclName() << NewTy << OldTy 17245 << New->getReturnTypeSourceRange(); 17246 Diag(Old->getLocation(), diag::note_overridden_virtual_function) 17247 << Old->getReturnTypeSourceRange(); 17248 17249 return true; 17250 } 17251 17252 if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) { 17253 // C++14 [class.virtual]p8: 17254 // If the class type in the covariant return type of D::f differs from 17255 // that of B::f, the class type in the return type of D::f shall be 17256 // complete at the point of declaration of D::f or shall be the class 17257 // type D. 17258 if (const RecordType *RT = NewClassTy->getAs<RecordType>()) { 17259 if (!RT->isBeingDefined() && 17260 RequireCompleteType(New->getLocation(), NewClassTy, 17261 diag::err_covariant_return_incomplete, 17262 New->getDeclName())) 17263 return true; 17264 } 17265 17266 // Check if the new class derives from the old class. 17267 if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) { 17268 Diag(New->getLocation(), diag::err_covariant_return_not_derived) 17269 << New->getDeclName() << NewTy << OldTy 17270 << New->getReturnTypeSourceRange(); 17271 Diag(Old->getLocation(), diag::note_overridden_virtual_function) 17272 << Old->getReturnTypeSourceRange(); 17273 return true; 17274 } 17275 17276 // Check if we the conversion from derived to base is valid. 17277 if (CheckDerivedToBaseConversion( 17278 NewClassTy, OldClassTy, 17279 diag::err_covariant_return_inaccessible_base, 17280 diag::err_covariant_return_ambiguous_derived_to_base_conv, 17281 New->getLocation(), New->getReturnTypeSourceRange(), 17282 New->getDeclName(), nullptr)) { 17283 // FIXME: this note won't trigger for delayed access control 17284 // diagnostics, and it's impossible to get an undelayed error 17285 // here from access control during the original parse because 17286 // the ParsingDeclSpec/ParsingDeclarator are still in scope. 17287 Diag(Old->getLocation(), diag::note_overridden_virtual_function) 17288 << Old->getReturnTypeSourceRange(); 17289 return true; 17290 } 17291 } 17292 17293 // The qualifiers of the return types must be the same. 17294 if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) { 17295 Diag(New->getLocation(), 17296 diag::err_covariant_return_type_different_qualifications) 17297 << New->getDeclName() << NewTy << OldTy 17298 << New->getReturnTypeSourceRange(); 17299 Diag(Old->getLocation(), diag::note_overridden_virtual_function) 17300 << Old->getReturnTypeSourceRange(); 17301 return true; 17302 } 17303 17304 17305 // The new class type must have the same or less qualifiers as the old type. 17306 if (NewClassTy.isMoreQualifiedThan(OldClassTy)) { 17307 Diag(New->getLocation(), 17308 diag::err_covariant_return_type_class_type_more_qualified) 17309 << New->getDeclName() << NewTy << OldTy 17310 << New->getReturnTypeSourceRange(); 17311 Diag(Old->getLocation(), diag::note_overridden_virtual_function) 17312 << Old->getReturnTypeSourceRange(); 17313 return true; 17314 } 17315 17316 return false; 17317} 17318 17319/// Mark the given method pure. 17320/// 17321/// \param Method the method to be marked pure. 17322/// 17323/// \param InitRange the source range that covers the "0" initializer. 17324bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) { 17325 SourceLocation EndLoc = InitRange.getEnd(); 17326 if (EndLoc.isValid()) 17327 Method->setRangeEnd(EndLoc); 17328 17329 if (Method->isVirtual() || Method->getParent()->isDependentContext()) { 17330 Method->setPure(); 17331 return false; 17332 } 17333 17334 if (!Method->isInvalidDecl()) 17335 Diag(Method->getLocation(), diag::err_non_virtual_pure) 17336 << Method->getDeclName() << InitRange; 17337 return true; 17338} 17339 17340void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) { 17341 if (D->getFriendObjectKind()) 17342 Diag(D->getLocation(), diag::err_pure_friend); 17343 else if (auto *M = dyn_cast<CXXMethodDecl>(D)) 17344 CheckPureMethod(M, ZeroLoc); 17345 else 17346 Diag(D->getLocation(), diag::err_illegal_initializer); 17347} 17348 17349/// Determine whether the given declaration is a global variable or 17350/// static data member. 17351static bool isNonlocalVariable(const Decl *D) { 17352 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D)) 17353 return Var->hasGlobalStorage(); 17354 17355 return false; 17356} 17357 17358/// Invoked when we are about to parse an initializer for the declaration 17359/// 'Dcl'. 17360/// 17361/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a 17362/// static data member of class X, names should be looked up in the scope of 17363/// class X. If the declaration had a scope specifier, a scope will have 17364/// been created and passed in for this purpose. Otherwise, S will be null. 17365void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) { 17366 // If there is no declaration, there was an error parsing it. 17367 if (!D || D->isInvalidDecl()) 17368 return; 17369 17370 // We will always have a nested name specifier here, but this declaration 17371 // might not be out of line if the specifier names the current namespace: 17372 // extern int n; 17373 // int ::n = 0; 17374 if (S && D->isOutOfLine()) 17375 EnterDeclaratorContext(S, D->getDeclContext()); 17376 17377 // If we are parsing the initializer for a static data member, push a 17378 // new expression evaluation context that is associated with this static 17379 // data member. 17380 if (isNonlocalVariable(D)) 17381 PushExpressionEvaluationContext( 17382 ExpressionEvaluationContext::PotentiallyEvaluated, D); 17383} 17384 17385/// Invoked after we are finished parsing an initializer for the declaration D. 17386void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) { 17387 // If there is no declaration, there was an error parsing it. 17388 if (!D || D->isInvalidDecl()) 17389 return; 17390 17391 if (isNonlocalVariable(D)) 17392 PopExpressionEvaluationContext(); 17393 17394 if (S && D->isOutOfLine()) 17395 ExitDeclaratorContext(S); 17396} 17397 17398/// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a 17399/// C++ if/switch/while/for statement. 17400/// e.g: "if (int x = f()) {...}" 17401DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) { 17402 // C++ 6.4p2: 17403 // The declarator shall not specify a function or an array. 17404 // The type-specifier-seq shall not contain typedef and shall not declare a 17405 // new class or enumeration. 17406 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&((void)0) 17407 "Parser allowed 'typedef' as storage class of condition decl.")((void)0); 17408 17409 Decl *Dcl = ActOnDeclarator(S, D); 17410 if (!Dcl) 17411 return true; 17412 17413 if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function. 17414 Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type) 17415 << D.getSourceRange(); 17416 return true; 17417 } 17418 17419 return Dcl; 17420} 17421 17422void Sema::LoadExternalVTableUses() { 17423 if (!ExternalSource) 17424 return; 17425 17426 SmallVector<ExternalVTableUse, 4> VTables; 17427 ExternalSource->ReadUsedVTables(VTables); 17428 SmallVector<VTableUse, 4> NewUses; 17429 for (unsigned I = 0, N = VTables.size(); I != N; ++I) { 17430 llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos 17431 = VTablesUsed.find(VTables[I].Record); 17432 // Even if a definition wasn't required before, it may be required now. 17433 if (Pos != VTablesUsed.end()) { 17434 if (!Pos->second && VTables[I].DefinitionRequired) 17435 Pos->second = true; 17436 continue; 17437 } 17438 17439 VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired; 17440 NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location)); 17441 } 17442 17443 VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end()); 17444} 17445 17446void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class, 17447 bool DefinitionRequired) { 17448 // Ignore any vtable uses in unevaluated operands or for classes that do 17449 // not have a vtable. 17450 if (!Class->isDynamicClass() || Class->isDependentContext() || 17451 CurContext->isDependentContext() || isUnevaluatedContext()) 17452 return; 17453 // Do not mark as used if compiling for the device outside of the target 17454 // region. 17455 if (TUKind != TU_Prefix && LangOpts.OpenMP && LangOpts.OpenMPIsDevice && 17456 !isInOpenMPDeclareTargetContext() && 17457 !isInOpenMPTargetExecutionDirective()) { 17458 if (!DefinitionRequired) 17459 MarkVirtualMembersReferenced(Loc, Class); 17460 return; 17461 } 17462 17463 // Try to insert this class into the map. 17464 LoadExternalVTableUses(); 17465 Class = Class->getCanonicalDecl(); 17466 std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool> 17467 Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired)); 17468 if (!Pos.second) { 17469 // If we already had an entry, check to see if we are promoting this vtable 17470 // to require a definition. If so, we need to reappend to the VTableUses 17471 // list, since we may have already processed the first entry. 17472 if (DefinitionRequired && !Pos.first->second) { 17473 Pos.first->second = true; 17474 } else { 17475 // Otherwise, we can early exit. 17476 return; 17477 } 17478 } else { 17479 // The Microsoft ABI requires that we perform the destructor body 17480 // checks (i.e. operator delete() lookup) when the vtable is marked used, as 17481 // the deleting destructor is emitted with the vtable, not with the 17482 // destructor definition as in the Itanium ABI. 17483 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) { 17484 CXXDestructorDecl *DD = Class->getDestructor(); 17485 if (DD && DD->isVirtual() && !DD->isDeleted()) { 17486 if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) { 17487 // If this is an out-of-line declaration, marking it referenced will 17488 // not do anything. Manually call CheckDestructor to look up operator 17489 // delete(). 17490 ContextRAII SavedContext(*this, DD); 17491 CheckDestructor(DD); 17492 } else { 17493 MarkFunctionReferenced(Loc, Class->getDestructor()); 17494 } 17495 } 17496 } 17497 } 17498 17499 // Local classes need to have their virtual members marked 17500 // immediately. For all other classes, we mark their virtual members 17501 // at the end of the translation unit. 17502 if (Class->isLocalClass()) 17503 MarkVirtualMembersReferenced(Loc, Class); 17504 else 17505 VTableUses.push_back(std::make_pair(Class, Loc)); 17506} 17507 17508bool Sema::DefineUsedVTables() { 17509 LoadExternalVTableUses(); 17510 if (VTableUses.empty()) 17511 return false; 17512 17513 // Note: The VTableUses vector could grow as a result of marking 17514 // the members of a class as "used", so we check the size each 17515 // time through the loop and prefer indices (which are stable) to 17516 // iterators (which are not). 17517 bool DefinedAnything = false; 17518 for (unsigned I = 0; I != VTableUses.size(); ++I) { 17519 CXXRecordDecl *Class = VTableUses[I].first->getDefinition(); 17520 if (!Class) 17521 continue; 17522 TemplateSpecializationKind ClassTSK = 17523 Class->getTemplateSpecializationKind(); 17524 17525 SourceLocation Loc = VTableUses[I].second; 17526 17527 bool DefineVTable = true; 17528 17529 // If this class has a key function, but that key function is 17530 // defined in another translation unit, we don't need to emit the 17531 // vtable even though we're using it. 17532 const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class); 17533 if (KeyFunction && !KeyFunction->hasBody()) { 17534 // The key function is in another translation unit. 17535 DefineVTable = false; 17536 TemplateSpecializationKind TSK = 17537 KeyFunction->getTemplateSpecializationKind(); 17538 assert(TSK != TSK_ExplicitInstantiationDefinition &&((void)0) 17539 TSK != TSK_ImplicitInstantiation &&((void)0) 17540 "Instantiations don't have key functions")((void)0); 17541 (void)TSK; 17542 } else if (!KeyFunction) { 17543 // If we have a class with no key function that is the subject 17544 // of an explicit instantiation declaration, suppress the 17545 // vtable; it will live with the explicit instantiation 17546 // definition. 17547 bool IsExplicitInstantiationDeclaration = 17548 ClassTSK == TSK_ExplicitInstantiationDeclaration; 17549 for (auto R : Class->redecls()) { 17550 TemplateSpecializationKind TSK 17551 = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind(); 17552 if (TSK == TSK_ExplicitInstantiationDeclaration) 17553 IsExplicitInstantiationDeclaration = true; 17554 else if (TSK == TSK_ExplicitInstantiationDefinition) { 17555 IsExplicitInstantiationDeclaration = false; 17556 break; 17557 } 17558 } 17559 17560 if (IsExplicitInstantiationDeclaration) 17561 DefineVTable = false; 17562 } 17563 17564 // The exception specifications for all virtual members may be needed even 17565 // if we are not providing an authoritative form of the vtable in this TU. 17566 // We may choose to emit it available_externally anyway. 17567 if (!DefineVTable) { 17568 MarkVirtualMemberExceptionSpecsNeeded(Loc, Class); 17569 continue; 17570 } 17571 17572 // Mark all of the virtual members of this class as referenced, so 17573 // that we can build a vtable. Then, tell the AST consumer that a 17574 // vtable for this class is required. 17575 DefinedAnything = true; 17576 MarkVirtualMembersReferenced(Loc, Class); 17577 CXXRecordDecl *Canonical = Class->getCanonicalDecl(); 17578 if (VTablesUsed[Canonical]) 17579 Consumer.HandleVTable(Class); 17580 17581 // Warn if we're emitting a weak vtable. The vtable will be weak if there is 17582 // no key function or the key function is inlined. Don't warn in C++ ABIs 17583 // that lack key functions, since the user won't be able to make one. 17584 if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() && 17585 Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) { 17586 const FunctionDecl *KeyFunctionDef = nullptr; 17587 if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) && 17588 KeyFunctionDef->isInlined())) { 17589 Diag(Class->getLocation(), 17590 ClassTSK == TSK_ExplicitInstantiationDefinition 17591 ? diag::warn_weak_template_vtable 17592 : diag::warn_weak_vtable) 17593 << Class; 17594 } 17595 } 17596 } 17597 VTableUses.clear(); 17598 17599 return DefinedAnything; 17600} 17601 17602void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc, 17603 const CXXRecordDecl *RD) { 17604 for (const auto *I : RD->methods()) 17605 if (I->isVirtual() && !I->isPure()) 17606 ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>()); 17607} 17608 17609void Sema::MarkVirtualMembersReferenced(SourceLocation Loc, 17610 const CXXRecordDecl *RD, 17611 bool ConstexprOnly) { 17612 // Mark all functions which will appear in RD's vtable as used. 17613 CXXFinalOverriderMap FinalOverriders; 17614 RD->getFinalOverriders(FinalOverriders); 17615 for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(), 17616 E = FinalOverriders.end(); 17617 I != E; ++I) { 17618 for (OverridingMethods::const_iterator OI = I->second.begin(), 17619 OE = I->second.end(); 17620 OI != OE; ++OI) { 17621 assert(OI->second.size() > 0 && "no final overrider")((void)0); 17622 CXXMethodDecl *Overrider = OI->second.front().Method; 17623 17624 // C++ [basic.def.odr]p2: 17625 // [...] A virtual member function is used if it is not pure. [...] 17626 if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr())) 17627 MarkFunctionReferenced(Loc, Overrider); 17628 } 17629 } 17630 17631 // Only classes that have virtual bases need a VTT. 17632 if (RD->getNumVBases() == 0) 17633 return; 17634 17635 for (const auto &I : RD->bases()) { 17636 const auto *Base = 17637 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl()); 17638 if (Base->getNumVBases() == 0) 17639 continue; 17640 MarkVirtualMembersReferenced(Loc, Base); 17641 } 17642} 17643 17644/// SetIvarInitializers - This routine builds initialization ASTs for the 17645/// Objective-C implementation whose ivars need be initialized. 17646void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) { 17647 if (!getLangOpts().CPlusPlus) 17648 return; 17649 if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) { 17650 SmallVector<ObjCIvarDecl*, 8> ivars; 17651 CollectIvarsToConstructOrDestruct(OID, ivars); 17652 if (ivars.empty()) 17653 return; 17654 SmallVector<CXXCtorInitializer*, 32> AllToInit; 17655 for (unsigned i = 0; i < ivars.size(); i++) { 17656 FieldDecl *Field = ivars[i]; 17657 if (Field->isInvalidDecl()) 17658 continue; 17659 17660 CXXCtorInitializer *Member; 17661 InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field); 17662 InitializationKind InitKind = 17663 InitializationKind::CreateDefault(ObjCImplementation->getLocation()); 17664 17665 InitializationSequence InitSeq(*this, InitEntity, InitKind, None); 17666 ExprResult MemberInit = 17667 InitSeq.Perform(*this, InitEntity, InitKind, None); 17668 MemberInit = MaybeCreateExprWithCleanups(MemberInit); 17669 // Note, MemberInit could actually come back empty if no initialization 17670 // is required (e.g., because it would call a trivial default constructor) 17671 if (!MemberInit.get() || MemberInit.isInvalid()) 17672 continue; 17673 17674 Member = 17675 new (Context) CXXCtorInitializer(Context, Field, SourceLocation(), 17676 SourceLocation(), 17677 MemberInit.getAs<Expr>(), 17678 SourceLocation()); 17679 AllToInit.push_back(Member); 17680 17681 // Be sure that the destructor is accessible and is marked as referenced. 17682 if (const RecordType *RecordTy = 17683 Context.getBaseElementType(Field->getType()) 17684 ->getAs<RecordType>()) { 17685 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl()); 17686 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) { 17687 MarkFunctionReferenced(Field->getLocation(), Destructor); 17688 CheckDestructorAccess(Field->getLocation(), Destructor, 17689 PDiag(diag::err_access_dtor_ivar) 17690 << Context.getBaseElementType(Field->getType())); 17691 } 17692 } 17693 } 17694 ObjCImplementation->setIvarInitializers(Context, 17695 AllToInit.data(), AllToInit.size()); 17696 } 17697} 17698 17699static 17700void DelegatingCycleHelper(CXXConstructorDecl* Ctor, 17701 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid, 17702 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid, 17703 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current, 17704 Sema &S) { 17705 if (Ctor->isInvalidDecl()) 17706 return; 17707 17708 CXXConstructorDecl *Target = Ctor->getTargetConstructor(); 17709 17710 // Target may not be determinable yet, for instance if this is a dependent 17711 // call in an uninstantiated template. 17712 if (Target) { 17713 const FunctionDecl *FNTarget = nullptr; 17714 (void)Target->hasBody(FNTarget); 17715 Target = const_cast<CXXConstructorDecl*>( 17716 cast_or_null<CXXConstructorDecl>(FNTarget)); 17717 } 17718 17719 CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(), 17720 // Avoid dereferencing a null pointer here. 17721 *TCanonical = Target? Target->getCanonicalDecl() : nullptr; 17722 17723 if (!Current.insert(Canonical).second) 17724 return; 17725 17726 // We know that beyond here, we aren't chaining into a cycle. 17727 if (!Target || !Target->isDelegatingConstructor() || 17728 Target->isInvalidDecl() || Valid.count(TCanonical)) { 17729 Valid.insert(Current.begin(), Current.end()); 17730 Current.clear(); 17731 // We've hit a cycle. 17732 } else if (TCanonical == Canonical || Invalid.count(TCanonical) || 17733 Current.count(TCanonical)) { 17734 // If we haven't diagnosed this cycle yet, do so now. 17735 if (!Invalid.count(TCanonical)) { 17736 S.Diag((*Ctor->init_begin())->getSourceLocation(), 17737 diag::warn_delegating_ctor_cycle) 17738 << Ctor; 17739 17740 // Don't add a note for a function delegating directly to itself. 17741 if (TCanonical != Canonical) 17742 S.Diag(Target->getLocation(), diag::note_it_delegates_to); 17743 17744 CXXConstructorDecl *C = Target; 17745 while (C->getCanonicalDecl() != Canonical) { 17746 const FunctionDecl *FNTarget = nullptr; 17747 (void)C->getTargetConstructor()->hasBody(FNTarget); 17748 assert(FNTarget && "Ctor cycle through bodiless function")((void)0); 17749 17750 C = const_cast<CXXConstructorDecl*>( 17751 cast<CXXConstructorDecl>(FNTarget)); 17752 S.Diag(C->getLocation(), diag::note_which_delegates_to); 17753 } 17754 } 17755 17756 Invalid.insert(Current.begin(), Current.end()); 17757 Current.clear(); 17758 } else { 17759 DelegatingCycleHelper(Target, Valid, Invalid, Current, S); 17760 } 17761} 17762 17763 17764void Sema::CheckDelegatingCtorCycles() { 17765 llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current; 17766 17767 for (DelegatingCtorDeclsType::iterator 17768 I = DelegatingCtorDecls.begin(ExternalSource), 17769 E = DelegatingCtorDecls.end(); 17770 I != E; ++I) 17771 DelegatingCycleHelper(*I, Valid, Invalid, Current, *this); 17772 17773 for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI) 17774 (*CI)->setInvalidDecl(); 17775} 17776 17777namespace { 17778 /// AST visitor that finds references to the 'this' expression. 17779 class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> { 17780 Sema &S; 17781 17782 public: 17783 explicit FindCXXThisExpr(Sema &S) : S(S) { } 17784 17785 bool VisitCXXThisExpr(CXXThisExpr *E) { 17786 S.Diag(E->getLocation(), diag::err_this_static_member_func) 17787 << E->isImplicit(); 17788 return false; 17789 } 17790 }; 17791} 17792 17793bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) { 17794 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); 17795 if (!TSInfo) 17796 return false; 17797 17798 TypeLoc TL = TSInfo->getTypeLoc(); 17799 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>(); 17800 if (!ProtoTL) 17801 return false; 17802 17803 // C++11 [expr.prim.general]p3: 17804 // [The expression this] shall not appear before the optional 17805 // cv-qualifier-seq and it shall not appear within the declaration of a 17806 // static member function (although its type and value category are defined 17807 // within a static member function as they are within a non-static member 17808 // function). [ Note: this is because declaration matching does not occur 17809 // until the complete declarator is known. - end note ] 17810 const FunctionProtoType *Proto = ProtoTL.getTypePtr(); 17811 FindCXXThisExpr Finder(*this); 17812 17813 // If the return type came after the cv-qualifier-seq, check it now. 17814 if (Proto->hasTrailingReturn() && 17815 !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc())) 17816 return true; 17817 17818 // Check the exception specification. 17819 if (checkThisInStaticMemberFunctionExceptionSpec(Method)) 17820 return true; 17821 17822 // Check the trailing requires clause 17823 if (Expr *E = Method->getTrailingRequiresClause()) 17824 if (!Finder.TraverseStmt(E)) 17825 return true; 17826 17827 return checkThisInStaticMemberFunctionAttributes(Method); 17828} 17829 17830bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) { 17831 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo(); 17832 if (!TSInfo) 17833 return false; 17834 17835 TypeLoc TL = TSInfo->getTypeLoc(); 17836 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>(); 17837 if (!ProtoTL) 17838 return false; 17839 17840 const FunctionProtoType *Proto = ProtoTL.getTypePtr(); 17841 FindCXXThisExpr Finder(*this); 17842 17843 switch (Proto->getExceptionSpecType()) { 17844 case EST_Unparsed: 17845 case EST_Uninstantiated: 17846 case EST_Unevaluated: 17847 case EST_BasicNoexcept: 17848 case EST_NoThrow: 17849 case EST_DynamicNone: 17850 case EST_MSAny: 17851 case EST_None: 17852 break; 17853 17854 case EST_DependentNoexcept: 17855 case EST_NoexceptFalse: 17856 case EST_NoexceptTrue: 17857 if (!Finder.TraverseStmt(Proto->getNoexceptExpr())) 17858 return true; 17859 LLVM_FALLTHROUGH[[gnu::fallthrough]]; 17860 17861 case EST_Dynamic: 17862 for (const auto &E : Proto->exceptions()) { 17863 if (!Finder.TraverseType(E)) 17864 return true; 17865 } 17866 break; 17867 } 17868 17869 return false; 17870} 17871 17872bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) { 17873 FindCXXThisExpr Finder(*this); 17874 17875 // Check attributes. 17876 for (const auto *A : Method->attrs()) { 17877 // FIXME: This should be emitted by tblgen. 17878 Expr *Arg = nullptr; 17879 ArrayRef<Expr *> Args; 17880 if (const auto *G = dyn_cast<GuardedByAttr>(A)) 17881 Arg = G->getArg(); 17882 else if (const auto *G = dyn_cast<PtGuardedByAttr>(A)) 17883 Arg = G->getArg(); 17884 else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A)) 17885 Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size()); 17886 else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A)) 17887 Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size()); 17888 else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) { 17889 Arg = ETLF->getSuccessValue(); 17890 Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size()); 17891 } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) { 17892 Arg = STLF->getSuccessValue(); 17893 Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size()); 17894 } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A)) 17895 Arg = LR->getArg(); 17896 else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A)) 17897 Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size()); 17898 else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A)) 17899 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size()); 17900 else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A)) 17901 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size()); 17902 else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A)) 17903 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size()); 17904 else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A)) 17905 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size()); 17906 17907 if (Arg && !Finder.TraverseStmt(Arg)) 17908 return true; 17909 17910 for (unsigned I = 0, N = Args.size(); I != N; ++I) { 17911 if (!Finder.TraverseStmt(Args[I])) 17912 return true; 17913 } 17914 } 17915 17916 return false; 17917} 17918 17919void Sema::checkExceptionSpecification( 17920 bool IsTopLevel, ExceptionSpecificationType EST, 17921 ArrayRef<ParsedType> DynamicExceptions, 17922 ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr, 17923 SmallVectorImpl<QualType> &Exceptions, 17924 FunctionProtoType::ExceptionSpecInfo &ESI) { 17925 Exceptions.clear(); 17926 ESI.Type = EST; 17927 if (EST == EST_Dynamic) { 17928 Exceptions.reserve(DynamicExceptions.size()); 17929 for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) { 17930 // FIXME: Preserve type source info. 17931 QualType ET = GetTypeFromParser(DynamicExceptions[ei]); 17932 17933 if (IsTopLevel) { 17934 SmallVector<UnexpandedParameterPack, 2> Unexpanded; 17935 collectUnexpandedParameterPacks(ET, Unexpanded); 17936 if (!Unexpanded.empty()) { 17937 DiagnoseUnexpandedParameterPacks( 17938 DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType, 17939 Unexpanded); 17940 continue; 17941 } 17942 } 17943 17944 // Check that the type is valid for an exception spec, and 17945 // drop it if not. 17946 if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei])) 17947 Exceptions.push_back(ET); 17948 } 17949 ESI.Exceptions = Exceptions; 17950 return; 17951 } 17952 17953 if (isComputedNoexcept(EST)) { 17954 assert((NoexceptExpr->isTypeDependent() ||((void)0) 17955 NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==((void)0) 17956 Context.BoolTy) &&((void)0) 17957 "Parser should have made sure that the expression is boolean")((void)0); 17958 if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) { 17959 ESI.Type = EST_BasicNoexcept; 17960 return; 17961 } 17962 17963 ESI.NoexceptExpr = NoexceptExpr; 17964 return; 17965 } 17966} 17967 17968void Sema::actOnDelayedExceptionSpecification(Decl *MethodD, 17969 ExceptionSpecificationType EST, 17970 SourceRange SpecificationRange, 17971 ArrayRef<ParsedType> DynamicExceptions, 17972 ArrayRef<SourceRange> DynamicExceptionRanges, 17973 Expr *NoexceptExpr) { 17974 if (!MethodD) 17975 return; 17976 17977 // Dig out the method we're referring to. 17978 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD)) 17979 MethodD = FunTmpl->getTemplatedDecl(); 17980 17981 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD); 17982 if (!Method) 17983 return; 17984 17985 // Check the exception specification. 17986 llvm::SmallVector<QualType, 4> Exceptions; 17987 FunctionProtoType::ExceptionSpecInfo ESI; 17988 checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions, 17989 DynamicExceptionRanges, NoexceptExpr, Exceptions, 17990 ESI); 17991 17992 // Update the exception specification on the function type. 17993 Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true); 17994 17995 if (Method->isStatic()) 17996 checkThisInStaticMemberFunctionExceptionSpec(Method); 17997 17998 if (Method->isVirtual()) { 17999 // Check overrides, which we previously had to delay. 18000 for (const CXXMethodDecl *O : Method->overridden_methods()) 18001 CheckOverridingFunctionExceptionSpec(Method, O); 18002 } 18003} 18004 18005/// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class. 18006/// 18007MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record, 18008 SourceLocation DeclStart, Declarator &D, 18009 Expr *BitWidth, 18010 InClassInitStyle InitStyle, 18011 AccessSpecifier AS, 18012 const ParsedAttr &MSPropertyAttr) { 18013 IdentifierInfo *II = D.getIdentifier(); 18014 if (!II) { 18015 Diag(DeclStart, diag::err_anonymous_property); 18016 return nullptr; 18017 } 18018 SourceLocation Loc = D.getIdentifierLoc(); 18019 18020 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); 18021 QualType T = TInfo->getType(); 18022 if (getLangOpts().CPlusPlus) { 18023 CheckExtraCXXDefaultArguments(D); 18024 18025 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo, 18026 UPPC_DataMemberType)) { 18027 D.setInvalidType(); 18028 T = Context.IntTy; 18029 TInfo = Context.getTrivialTypeSourceInfo(T, Loc); 18030 } 18031 } 18032 18033 DiagnoseFunctionSpecifiers(D.getDeclSpec()); 18034 18035 if (D.getDeclSpec().isInlineSpecified()) 18036 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function) 18037 << getLangOpts().CPlusPlus17; 18038 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) 18039 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(), 18040 diag::err_invalid_thread) 18041 << DeclSpec::getSpecifierName(TSCS); 18042 18043 // Check to see if this name was declared as a member previously 18044 NamedDecl *PrevDecl = nullptr; 18045 LookupResult Previous(*this, II, Loc, LookupMemberName, 18046 ForVisibleRedeclaration); 18047 LookupName(Previous, S); 18048 switch (Previous.getResultKind()) { 18049 case LookupResult::Found: 18050 case LookupResult::FoundUnresolvedValue: 18051 PrevDecl = Previous.getAsSingle<NamedDecl>(); 18052 break; 18053 18054 case LookupResult::FoundOverloaded: 18055 PrevDecl = Previous.getRepresentativeDecl(); 18056 break; 18057 18058 case LookupResult::NotFound: 18059 case LookupResult::NotFoundInCurrentInstantiation: 18060 case LookupResult::Ambiguous: 18061 break; 18062 } 18063 18064 if (PrevDecl && PrevDecl->isTemplateParameter()) { 18065 // Maybe we will complain about the shadowed template parameter. 18066 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl); 18067 // Just pretend that we didn't see the previous declaration. 18068 PrevDecl = nullptr; 18069 } 18070 18071 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S)) 18072 PrevDecl = nullptr; 18073 18074 SourceLocation TSSL = D.getBeginLoc(); 18075 MSPropertyDecl *NewPD = 18076 MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL, 18077 MSPropertyAttr.getPropertyDataGetter(), 18078 MSPropertyAttr.getPropertyDataSetter()); 18079 ProcessDeclAttributes(TUScope, NewPD, D); 18080 NewPD->setAccess(AS); 18081 18082 if (NewPD->isInvalidDecl()) 18083 Record->setInvalidDecl(); 18084 18085 if (D.getDeclSpec().isModulePrivateSpecified()) 18086 NewPD->setModulePrivate(); 18087 18088 if (NewPD->isInvalidDecl() && PrevDecl) { 18089 // Don't introduce NewFD into scope; there's already something 18090 // with the same name in the same scope. 18091 } else if (II) { 18092 PushOnScopeChains(NewPD, S); 18093 } else 18094 Record->addDecl(NewPD); 18095 18096 return NewPD; 18097} 18098 18099void Sema::ActOnStartFunctionDeclarationDeclarator( 18100 Declarator &Declarator, unsigned TemplateParameterDepth) { 18101 auto &Info = InventedParameterInfos.emplace_back(); 18102 TemplateParameterList *ExplicitParams = nullptr; 18103 ArrayRef<TemplateParameterList *> ExplicitLists = 18104 Declarator.getTemplateParameterLists(); 18105 if (!ExplicitLists.empty()) { 18106 bool IsMemberSpecialization, IsInvalid; 18107 ExplicitParams = MatchTemplateParametersToScopeSpecifier( 18108 Declarator.getBeginLoc(), Declarator.getIdentifierLoc(), 18109 Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr, 18110 ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid, 18111 /*SuppressDiagnostic=*/true); 18112 } 18113 if (ExplicitParams) { 18114 Info.AutoTemplateParameterDepth = ExplicitParams->getDepth(); 18115 for (NamedDecl *Param : *ExplicitParams) 18116 Info.TemplateParams.push_back(Param); 18117 Info.NumExplicitTemplateParams = ExplicitParams->size(); 18118 } else { 18119 Info.AutoTemplateParameterDepth = TemplateParameterDepth; 18120 Info.NumExplicitTemplateParams = 0; 18121 } 18122} 18123 18124void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) { 18125 auto &FSI = InventedParameterInfos.back(); 18126 if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) { 18127 if (FSI.NumExplicitTemplateParams != 0) { 18128 TemplateParameterList *ExplicitParams = 18129 Declarator.getTemplateParameterLists().back(); 18130 Declarator.setInventedTemplateParameterList( 18131 TemplateParameterList::Create( 18132 Context, ExplicitParams->getTemplateLoc(), 18133 ExplicitParams->getLAngleLoc(), FSI.TemplateParams, 18134 ExplicitParams->getRAngleLoc(), 18135 ExplicitParams->getRequiresClause())); 18136 } else { 18137 Declarator.setInventedTemplateParameterList( 18138 TemplateParameterList::Create( 18139 Context, SourceLocation(), SourceLocation(), FSI.TemplateParams, 18140 SourceLocation(), /*RequiresClause=*/nullptr)); 18141 } 18142 } 18143 InventedParameterInfos.pop_back(); 18144}

←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/AST/Decl.h

→

1//===- Decl.h - 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 subclasses.
10//
11//===----------------------------------------------------------------------===//

13#ifndef LLVM_CLANG_AST_DECL_H
14#define LLVM_CLANG_AST_DECL_H

16#include "clang/AST/APValue.h"
17#include "clang/AST/ASTContextAllocate.h"
18#include "clang/AST/DeclAccessPair.h"
19#include "clang/AST/DeclBase.h"
20#include "clang/AST/DeclarationName.h"
21#include "clang/AST/ExternalASTSource.h"
22#include "clang/AST/NestedNameSpecifier.h"
23#include "clang/AST/Redeclarable.h"
24#include "clang/AST/Type.h"
25#include "clang/Basic/AddressSpaces.h"
26#include "clang/Basic/Diagnostic.h"
27#include "clang/Basic/IdentifierTable.h"
28#include "clang/Basic/LLVM.h"
29#include "clang/Basic/Linkage.h"
30#include "clang/Basic/OperatorKinds.h"
31#include "clang/Basic/PartialDiagnostic.h"
32#include "clang/Basic/PragmaKinds.h"
33#include "clang/Basic/SourceLocation.h"
34#include "clang/Basic/Specifiers.h"
35#include "clang/Basic/Visibility.h"
36#include "llvm/ADT/APSInt.h"
37#include "llvm/ADT/ArrayRef.h"
38#include "llvm/ADT/Optional.h"
39#include "llvm/ADT/PointerIntPair.h"
40#include "llvm/ADT/PointerUnion.h"
41#include "llvm/ADT/StringRef.h"
42#include "llvm/ADT/iterator_range.h"
43#include "llvm/Support/Casting.h"
44#include "llvm/Support/Compiler.h"
45#include "llvm/Support/TrailingObjects.h"
46#include <cassert>
47#include <cstddef>
48#include <cstdint>
49#include <string>
50#include <utility>

52namespace clang {

54class ASTContext;
55struct ASTTemplateArgumentListInfo;
56class Attr;
57class CompoundStmt;
58class DependentFunctionTemplateSpecializationInfo;
59class EnumDecl;
60class Expr;
61class FunctionTemplateDecl;
62class FunctionTemplateSpecializationInfo;
63class FunctionTypeLoc;
64class LabelStmt;
65class MemberSpecializationInfo;
66class Module;
67class NamespaceDecl;
68class ParmVarDecl;
69class RecordDecl;
70class Stmt;
71class StringLiteral;
72class TagDecl;
73class TemplateArgumentList;
74class TemplateArgumentListInfo;
75class TemplateParameterList;
76class TypeAliasTemplateDecl;
77class TypeLoc;
78class UnresolvedSetImpl;
79class VarTemplateDecl;

81/// The top declaration context.
82class TranslationUnitDecl : public Decl,
                          public DeclContext,
                          public Redeclarable<TranslationUnitDecl> {
using redeclarable_base = Redeclarable<TranslationUnitDecl>;

TranslationUnitDecl *getNextRedeclarationImpl() override {
  return getNextRedeclaration();
}

TranslationUnitDecl *getPreviousDeclImpl() override {
  return getPreviousDecl();
}

TranslationUnitDecl *getMostRecentDeclImpl() override {
  return getMostRecentDecl();
}

ASTContext &Ctx;

/// The (most recently entered) anonymous namespace for this
/// translation unit, if one has been created.
NamespaceDecl *AnonymousNamespace = nullptr;

explicit TranslationUnitDecl(ASTContext &ctx);

virtual void anchor();

109public:
using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::getMostRecentDecl;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::isFirstDecl;
using redeclarable_base::redecls;
using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;

ASTContext &getASTContext() const { return Ctx; }

NamespaceDecl *getAnonymousNamespace() const { return AnonymousNamespace; }
void setAnonymousNamespace(NamespaceDecl *D) { AnonymousNamespace = D; }

static TranslationUnitDecl *Create(ASTContext &C);

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == TranslationUnit; }
static DeclContext *castToDeclContext(const TranslationUnitDecl *D) {
  return static_cast<DeclContext *>(const_cast<TranslationUnitDecl*>(D));
}
static TranslationUnitDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<TranslationUnitDecl *>(const_cast<DeclContext*>(DC));
}
136};

138/// Represents a `#pragma comment` line. Always a child of
139/// TranslationUnitDecl.
140class PragmaCommentDecl final
  : public Decl,
    private llvm::TrailingObjects<PragmaCommentDecl, char> {
friend class ASTDeclReader;
friend class ASTDeclWriter;
friend TrailingObjects;

PragmaMSCommentKind CommentKind;

PragmaCommentDecl(TranslationUnitDecl *TU, SourceLocation CommentLoc,
                  PragmaMSCommentKind CommentKind)
    : Decl(PragmaComment, TU, CommentLoc), CommentKind(CommentKind) {}

virtual void anchor();

155public:
static PragmaCommentDecl *Create(const ASTContext &C, TranslationUnitDecl *DC,
                                 SourceLocation CommentLoc,
                                 PragmaMSCommentKind CommentKind,
                                 StringRef Arg);
static PragmaCommentDecl *CreateDeserialized(ASTContext &C, unsigned ID,
                                             unsigned ArgSize);

PragmaMSCommentKind getCommentKind() const { return CommentKind; }

StringRef getArg() const { return getTrailingObjects<char>(); }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == PragmaComment; }
170};

172/// Represents a `#pragma detect_mismatch` line. Always a child of
173/// TranslationUnitDecl.
174class PragmaDetectMismatchDecl final
  : public Decl,
    private llvm::TrailingObjects<PragmaDetectMismatchDecl, char> {
friend class ASTDeclReader;
friend class ASTDeclWriter;
friend TrailingObjects;

size_t ValueStart;

PragmaDetectMismatchDecl(TranslationUnitDecl *TU, SourceLocation Loc,
                         size_t ValueStart)
    : Decl(PragmaDetectMismatch, TU, Loc), ValueStart(ValueStart) {}

virtual void anchor();

189public:
static PragmaDetectMismatchDecl *Create(const ASTContext &C,
                                        TranslationUnitDecl *DC,
                                        SourceLocation Loc, StringRef Name,
                                        StringRef Value);
static PragmaDetectMismatchDecl *
CreateDeserialized(ASTContext &C, unsigned ID, unsigned NameValueSize);

StringRef getName() const { return getTrailingObjects<char>(); }
StringRef getValue() const { return getTrailingObjects<char>() + ValueStart; }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == PragmaDetectMismatch; }
203};

205/// Declaration context for names declared as extern "C" in C++. This
206/// is neither the semantic nor lexical context for such declarations, but is
207/// used to check for conflicts with other extern "C" declarations. Example:
208///
209/// \code
210///   namespace N { extern "C" void f(); } // #1
211///   void N::f() {}                       // #2
212///   namespace M { extern "C" void f(); } // #3
213/// \endcode
214///
215/// The semantic context of #1 is namespace N and its lexical context is the
216/// LinkageSpecDecl; the semantic context of #2 is namespace N and its lexical
217/// context is the TU. However, both declarations are also visible in the
218/// extern "C" context.
219///
220/// The declaration at #3 finds it is a redeclaration of \c N::f through
221/// lookup in the extern "C" context.
222class ExternCContextDecl : public Decl, public DeclContext {
explicit ExternCContextDecl(TranslationUnitDecl *TU)
  : Decl(ExternCContext, TU, SourceLocation()),
    DeclContext(ExternCContext) {}

virtual void anchor();

229public:
static ExternCContextDecl *Create(const ASTContext &C,
                                  TranslationUnitDecl *TU);

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == ExternCContext; }
static DeclContext *castToDeclContext(const ExternCContextDecl *D) {
  return static_cast<DeclContext *>(const_cast<ExternCContextDecl*>(D));
}
static ExternCContextDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<ExternCContextDecl *>(const_cast<DeclContext*>(DC));
}
242};

244/// This represents a decl that may have a name.  Many decls have names such
245/// as ObjCMethodDecl, but not \@class, etc.
246///
247/// Note that not every NamedDecl is actually named (e.g., a struct might
248/// be anonymous), and not every name is an identifier.
249class NamedDecl : public Decl {
/// The name of this declaration, which is typically a normal
/// identifier but may also be a special kind of name (C++
/// constructor, Objective-C selector, etc.)
DeclarationName Name;

virtual void anchor();

257private:
NamedDecl *getUnderlyingDeclImpl() LLVM_READONLY__attribute__((__pure__));

260protected:
NamedDecl(Kind DK, DeclContext *DC, SourceLocation L, DeclarationName N)
    : Decl(DK, DC, L), Name(N) {}

264public:
/// Get the identifier that names this declaration, if there is one.
///
/// This will return NULL if this declaration has no name (e.g., for
/// an unnamed class) or if the name is a special name (C++ constructor,
/// Objective-C selector, etc.).
IdentifierInfo *getIdentifier() const { return Name.getAsIdentifierInfo(); }

/// Get the name of identifier for this declaration as a StringRef.
///
/// This requires that the declaration have a name and that it be a simple
/// identifier.
StringRef getName() const {
  assert(Name.isIdentifier() && "Name is not a simple identifier")((void)0);
  return getIdentifier() ? getIdentifier()->getName() : "";
}

/// Get a human-readable name for the declaration, even if it is one of the
/// special kinds of names (C++ constructor, Objective-C selector, etc).
///
/// Creating this name requires expensive string manipulation, so it should
/// be called only when performance doesn't matter. For simple declarations,
/// getNameAsCString() should suffice.
//
// FIXME: This function should be renamed to indicate that it is not just an
// alternate form of getName(), and clients should move as appropriate.
//
// FIXME: Deprecated, move clients to getName().
std::string getNameAsString() const { return Name.getAsString(); }

/// Pretty-print the unqualified name of this declaration. Can be overloaded
/// by derived classes to provide a more user-friendly name when appropriate.
virtual void printName(raw_ostream &os) const;

/// Get the actual, stored name of the declaration, which may be a special
/// name.
///
/// Note that generally in diagnostics, the non-null \p NamedDecl* itself
/// should be sent into the diagnostic instead of using the result of
/// \p getDeclName().
///
/// A \p DeclarationName in a diagnostic will just be streamed to the output,
/// which will directly result in a call to \p DeclarationName::print.
///
/// A \p NamedDecl* in a diagnostic will also ultimately result in a call to
/// \p DeclarationName::print, but with two customisation points along the
/// way (\p getNameForDiagnostic and \p printName). These are used to print
/// the template arguments if any, and to provide a user-friendly name for
/// some entities (such as unnamed variables and anonymous records).
DeclarationName getDeclName() const { return Name; }

/// Set the name of this declaration.
void setDeclName(DeclarationName N) { Name = N; }

/// Returns a human-readable qualified name for this declaration, like
/// A::B::i, for i being member of namespace A::B.
///
/// If the declaration is not a member of context which can be named (record,
/// namespace), it will return the same result as printName().
///
/// Creating this name is expensive, so it should be called only when
/// performance doesn't matter.
void printQualifiedName(raw_ostream &OS) const;
void printQualifiedName(raw_ostream &OS, const PrintingPolicy &Policy) const;

/// Print only the nested name specifier part of a fully-qualified name,
/// including the '::' at the end. E.g.
///    when `printQualifiedName(D)` prints "A::B::i",
///    this function prints "A::B::".
void printNestedNameSpecifier(raw_ostream &OS) const;
void printNestedNameSpecifier(raw_ostream &OS,
                              const PrintingPolicy &Policy) const;

// FIXME: Remove string version.
std::string getQualifiedNameAsString() const;

/// Appends a human-readable name for this declaration into the given stream.
///
/// This is the method invoked by Sema when displaying a NamedDecl
/// in a diagnostic.  It does not necessarily produce the same
/// result as printName(); for example, class template
/// specializations are printed with their template arguments.
virtual void getNameForDiagnostic(raw_ostream &OS,
                                  const PrintingPolicy &Policy,
                                  bool Qualified) const;

/// Determine whether this declaration, if known to be well-formed within
/// its context, will replace the declaration OldD if introduced into scope.
///
/// A declaration will replace another declaration if, for example, it is
/// a redeclaration of the same variable or function, but not if it is a
/// declaration of a different kind (function vs. class) or an overloaded
/// function.
///
/// \param IsKnownNewer \c true if this declaration is known to be newer
/// than \p OldD (for instance, if this declaration is newly-created).
bool declarationReplaces(NamedDecl *OldD, bool IsKnownNewer = true) const;

/// Determine whether this declaration has linkage.
bool hasLinkage() const;

using Decl::isModulePrivate;
using Decl::setModulePrivate;

/// Determine whether this declaration is a C++ class member.
bool isCXXClassMember() const {
  const DeclContext *DC = getDeclContext();

  // C++0x [class.mem]p1:
  //   The enumerators of an unscoped enumeration defined in
  //   the class are members of the class.
  if (isa<EnumDecl>(DC))
    DC = DC->getRedeclContext();

  return DC->isRecord();
}

/// Determine whether the given declaration is an instance member of
/// a C++ class.
bool isCXXInstanceMember() const;

/// Determine if the declaration obeys the reserved identifier rules of the
/// given language.
ReservedIdentifierStatus isReserved(const LangOptions &LangOpts) const;

/// Determine what kind of linkage this entity has.
///
/// This is not the linkage as defined by the standard or the codegen notion
/// of linkage. It is just an implementation detail that is used to compute
/// those.
Linkage getLinkageInternal() const;

/// Get the linkage from a semantic point of view. Entities in
/// anonymous namespaces are external (in c++98).
Linkage getFormalLinkage() const {
  return clang::getFormalLinkage(getLinkageInternal());
}

/// True if this decl has external linkage.
bool hasExternalFormalLinkage() const {
  return isExternalFormalLinkage(getLinkageInternal());
}

bool isExternallyVisible() const {
  return clang::isExternallyVisible(getLinkageInternal());
}

/// Determine whether this declaration can be redeclared in a
/// different translation unit.
bool isExternallyDeclarable() const {
  return isExternallyVisible() && !getOwningModuleForLinkage();
}

/// Determines the visibility of this entity.
Visibility getVisibility() const {
  return getLinkageAndVisibility().getVisibility();
}

/// Determines the linkage and visibility of this entity.
LinkageInfo getLinkageAndVisibility() const;

/// Kinds of explicit visibility.
enum ExplicitVisibilityKind {
  /// Do an LV computation for, ultimately, a type.
  /// Visibility may be restricted by type visibility settings and
  /// the visibility of template arguments.
  VisibilityForType,

  /// Do an LV computation for, ultimately, a non-type declaration.
  /// Visibility may be restricted by value visibility settings and
  /// the visibility of template arguments.
  VisibilityForValue
};

/// If visibility was explicitly specified for this
/// declaration, return that visibility.
Optional<Visibility>
getExplicitVisibility(ExplicitVisibilityKind kind) const;

/// True if the computed linkage is valid. Used for consistency
/// checking. Should always return true.
bool isLinkageValid() const;

/// True if something has required us to compute the linkage
/// of this declaration.
///
/// Language features which can retroactively change linkage (like a
/// typedef name for linkage purposes) may need to consider this,
/// but hopefully only in transitory ways during parsing.
bool hasLinkageBeenComputed() const {
  return hasCachedLinkage();
}

/// Looks through UsingDecls and ObjCCompatibleAliasDecls for
/// the underlying named decl.
NamedDecl *getUnderlyingDecl() {
  // Fast-path the common case.
  if (this->getKind() != UsingShadow &&
      this->getKind() != ConstructorUsingShadow &&
      this->getKind() != ObjCCompatibleAlias &&
      this->getKind() != NamespaceAlias)
    return this;

  return getUnderlyingDeclImpl();
}
const NamedDecl *getUnderlyingDecl() const {
  return const_cast<NamedDecl*>(this)->getUnderlyingDecl();
}

NamedDecl *getMostRecentDecl() {
  return cast<NamedDecl>(static_cast<Decl *>(this)->getMostRecentDecl());
}
const NamedDecl *getMostRecentDecl() const {
  return const_cast<NamedDecl*>(this)->getMostRecentDecl();
}

ObjCStringFormatFamily getObjCFStringFormattingFamily() const;

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstNamed && K <= lastNamed; }
484};

486inline raw_ostream &operator<<(raw_ostream &OS, const NamedDecl &ND) {
ND.printName(OS);
return OS;
489}

491/// Represents the declaration of a label.  Labels also have a
492/// corresponding LabelStmt, which indicates the position that the label was
493/// defined at.  For normal labels, the location of the decl is the same as the
494/// location of the statement.  For GNU local labels (__label__), the decl
495/// location is where the __label__ is.
496class LabelDecl : public NamedDecl {
LabelStmt *TheStmt;
StringRef MSAsmName;
bool MSAsmNameResolved = false;

/// For normal labels, this is the same as the main declaration
/// label, i.e., the location of the identifier; for GNU local labels,
/// this is the location of the __label__ keyword.
SourceLocation LocStart;

LabelDecl(DeclContext *DC, SourceLocation IdentL, IdentifierInfo *II,
          LabelStmt *S, SourceLocation StartL)
    : NamedDecl(Label, DC, IdentL, II), TheStmt(S), LocStart(StartL) {}

void anchor() override;

512public:
static LabelDecl *Create(ASTContext &C, DeclContext *DC,
                         SourceLocation IdentL, IdentifierInfo *II);
static LabelDecl *Create(ASTContext &C, DeclContext *DC,
                         SourceLocation IdentL, IdentifierInfo *II,
                         SourceLocation GnuLabelL);
static LabelDecl *CreateDeserialized(ASTContext &C, unsigned ID);

LabelStmt *getStmt() const { return TheStmt; }
void setStmt(LabelStmt *T) { TheStmt = T; }

bool isGnuLocal() const { return LocStart != getLocation(); }
void setLocStart(SourceLocation L) { LocStart = L; }

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(LocStart, getLocation());
}

bool isMSAsmLabel() const { return !MSAsmName.empty(); }
bool isResolvedMSAsmLabel() const { return isMSAsmLabel() && MSAsmNameResolved; }
void setMSAsmLabel(StringRef Name);
StringRef getMSAsmLabel() const { return MSAsmName; }
void setMSAsmLabelResolved() { MSAsmNameResolved = true; }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Label; }
539};

541/// Represent a C++ namespace.
542class NamespaceDecl : public NamedDecl, public DeclContext,
                    public Redeclarable<NamespaceDecl>
544{
/// The starting location of the source range, pointing
/// to either the namespace or the inline keyword.
SourceLocation LocStart;

/// The ending location of the source range.
SourceLocation RBraceLoc;

/// A pointer to either the anonymous namespace that lives just inside
/// this namespace or to the first namespace in the chain (the latter case
/// only when this is not the first in the chain), along with a
/// boolean value indicating whether this is an inline namespace.
llvm::PointerIntPair<NamespaceDecl *, 1, bool> AnonOrFirstNamespaceAndInline;

NamespaceDecl(ASTContext &C, DeclContext *DC, bool Inline,
              SourceLocation StartLoc, SourceLocation IdLoc,
              IdentifierInfo *Id, NamespaceDecl *PrevDecl);

using redeclarable_base = Redeclarable<NamespaceDecl>;

NamespaceDecl *getNextRedeclarationImpl() override;
NamespaceDecl *getPreviousDeclImpl() override;
NamespaceDecl *getMostRecentDeclImpl() override;

568public:
friend class ASTDeclReader;
friend class ASTDeclWriter;

static NamespaceDecl *Create(ASTContext &C, DeclContext *DC,
                             bool Inline, SourceLocation StartLoc,
                             SourceLocation IdLoc, IdentifierInfo *Id,
                             NamespaceDecl *PrevDecl);

static NamespaceDecl *CreateDeserialized(ASTContext &C, unsigned ID);

using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;
using redeclarable_base::redecls;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::getMostRecentDecl;
using redeclarable_base::isFirstDecl;

/// Returns true if this is an anonymous namespace declaration.
///
/// For example:
/// \code
///   namespace {
///     ...
///   };
/// \endcode
/// q.v. C++ [namespace.unnamed]
bool isAnonymousNamespace() const {
  return !getIdentifier();
}

/// Returns true if this is an inline namespace declaration.
bool isInline() const {
  return AnonOrFirstNamespaceAndInline.getInt();
}

/// Set whether this is an inline namespace declaration.
void setInline(bool Inline) {
  AnonOrFirstNamespaceAndInline.setInt(Inline);
}

/// Returns true if the inline qualifier for \c Name is redundant.
bool isRedundantInlineQualifierFor(DeclarationName Name) const {
  if (!isInline())
    return false;
  auto X = lookup(Name);
  auto Y = getParent()->lookup(Name);
  return std::distance(X.begin(), X.end()) ==
    std::distance(Y.begin(), Y.end());
}

/// Get the original (first) namespace declaration.
NamespaceDecl *getOriginalNamespace();

/// Get the original (first) namespace declaration.
const NamespaceDecl *getOriginalNamespace() const;

/// Return true if this declaration is an original (first) declaration
/// of the namespace. This is false for non-original (subsequent) namespace
/// declarations and anonymous namespaces.
bool isOriginalNamespace() const;

/// Retrieve the anonymous namespace nested inside this namespace,
/// if any.
NamespaceDecl *getAnonymousNamespace() const {
  return getOriginalNamespace()->AnonOrFirstNamespaceAndInline.getPointer();
}

void setAnonymousNamespace(NamespaceDecl *D) {
  getOriginalNamespace()->AnonOrFirstNamespaceAndInline.setPointer(D);
}

/// Retrieves the canonical declaration of this namespace.
NamespaceDecl *getCanonicalDecl() override {
  return getOriginalNamespace();
}
const NamespaceDecl *getCanonicalDecl() const {
  return getOriginalNamespace();
}

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(LocStart, RBraceLoc);
}

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return LocStart; }
SourceLocation getRBraceLoc() const { return RBraceLoc; }
void setLocStart(SourceLocation L) { LocStart = L; }
void setRBraceLoc(SourceLocation L) { RBraceLoc = L; }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Namespace; }
static DeclContext *castToDeclContext(const NamespaceDecl *D) {
  return static_cast<DeclContext *>(const_cast<NamespaceDecl*>(D));
}
static NamespaceDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<NamespaceDecl *>(const_cast<DeclContext*>(DC));
}
669};

671/// Represent the declaration of a variable (in which case it is
672/// an lvalue) a function (in which case it is a function designator) or
673/// an enum constant.
674class ValueDecl : public NamedDecl {
QualType DeclType;

void anchor() override;

679protected:
ValueDecl(Kind DK, DeclContext *DC, SourceLocation L,
          DeclarationName N, QualType T)
  : NamedDecl(DK, DC, L, N), DeclType(T) {}

684public:
QualType getType() const { return DeclType; }
void setType(QualType newType) { DeclType = newType; }

/// Determine whether this symbol is weakly-imported,
///        or declared with the weak or weak-ref attr.
bool isWeak() const;

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstValue && K <= lastValue; }
695};

697/// A struct with extended info about a syntactic
698/// name qualifier, to be used for the case of out-of-line declarations.
699struct QualifierInfo {
NestedNameSpecifierLoc QualifierLoc;

/// The number of "outer" template parameter lists.
/// The count includes all of the template parameter lists that were matched
/// against the template-ids occurring into the NNS and possibly (in the
/// case of an explicit specialization) a final "template <>".
unsigned NumTemplParamLists = 0;

/// A new-allocated array of size NumTemplParamLists,
/// containing pointers to the "outer" template parameter lists.
/// It includes all of the template parameter lists that were matched
/// against the template-ids occurring into the NNS and possibly (in the
/// case of an explicit specialization) a final "template <>".
TemplateParameterList** TemplParamLists = nullptr;

QualifierInfo() = default;
QualifierInfo(const QualifierInfo &) = delete;
QualifierInfo& operator=(const QualifierInfo &) = delete;

/// Sets info about "outer" template parameter lists.
void setTemplateParameterListsInfo(ASTContext &Context,
                                   ArrayRef<TemplateParameterList *> TPLists);
722};

724/// Represents a ValueDecl that came out of a declarator.
725/// Contains type source information through TypeSourceInfo.
726class DeclaratorDecl : public ValueDecl {
// A struct representing a TInfo, a trailing requires-clause and a syntactic
// qualifier, to be used for the (uncommon) case of out-of-line declarations
// and constrained function decls.
struct ExtInfo : public QualifierInfo {
  TypeSourceInfo *TInfo;
  Expr *TrailingRequiresClause = nullptr;
};

llvm::PointerUnion<TypeSourceInfo *, ExtInfo *> DeclInfo;

/// The start of the source range for this declaration,
/// ignoring outer template declarations.
SourceLocation InnerLocStart;

bool hasExtInfo() const { return DeclInfo.is<ExtInfo*>(); }
ExtInfo *getExtInfo() { return DeclInfo.get<ExtInfo*>(); }
const ExtInfo *getExtInfo() const { return DeclInfo.get<ExtInfo*>(); }

745protected:
DeclaratorDecl(Kind DK, DeclContext *DC, SourceLocation L,
               DeclarationName N, QualType T, TypeSourceInfo *TInfo,
               SourceLocation StartL)
    : ValueDecl(DK, DC, L, N, T), DeclInfo(TInfo), InnerLocStart(StartL) {}

751public:
friend class ASTDeclReader;
friend class ASTDeclWriter;

TypeSourceInfo *getTypeSourceInfo() const {
  return hasExtInfo()
    ? getExtInfo()->TInfo
    : DeclInfo.get<TypeSourceInfo*>();
}

void setTypeSourceInfo(TypeSourceInfo *TI) {
  if (hasExtInfo())
    getExtInfo()->TInfo = TI;
  else
    DeclInfo = TI;
}

/// Return start of source range ignoring outer template declarations.
SourceLocation getInnerLocStart() const { return InnerLocStart; }
void setInnerLocStart(SourceLocation L) { InnerLocStart = L; }

/// Return start of source range taking into account any outer template
/// declarations.
SourceLocation getOuterLocStart() const;

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) {
  return getOuterLocStart();
}

/// Retrieve the nested-name-specifier that qualifies the name of this
/// declaration, if it was present in the source.
NestedNameSpecifier *getQualifier() const {
  return hasExtInfo() ? getExtInfo()->QualifierLoc.getNestedNameSpecifier()
                      : nullptr;
}

/// Retrieve the nested-name-specifier (with source-location
/// information) that qualifies the name of this declaration, if it was
/// present in the source.
NestedNameSpecifierLoc getQualifierLoc() const {
  return hasExtInfo() ? getExtInfo()->QualifierLoc
                      : NestedNameSpecifierLoc();
}

void setQualifierInfo(NestedNameSpecifierLoc QualifierLoc);

/// \brief Get the constraint-expression introduced by the trailing
/// requires-clause in the function/member declaration, or null if no
/// requires-clause was provided.
Expr *getTrailingRequiresClause() {
  return hasExtInfo() ? getExtInfo()->TrailingRequiresClause
                      : nullptr;
}

const Expr *getTrailingRequiresClause() const {
  return hasExtInfo() ? getExtInfo()->TrailingRequiresClause
                      : nullptr;
}

void setTrailingRequiresClause(Expr *TrailingRequiresClause);

unsigned getNumTemplateParameterLists() const {
  return hasExtInfo() ? getExtInfo()->NumTemplParamLists : 0;
}

TemplateParameterList *getTemplateParameterList(unsigned index) const {
  assert(index < getNumTemplateParameterLists())((void)0);
  return getExtInfo()->TemplParamLists[index];
}

void setTemplateParameterListsInfo(ASTContext &Context,
                                   ArrayRef<TemplateParameterList *> TPLists);

SourceLocation getTypeSpecStartLoc() const;
SourceLocation getTypeSpecEndLoc() const;

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) {
  return K >= firstDeclarator && K <= lastDeclarator;
}
834};

836/// Structure used to store a statement, the constant value to
837/// which it was evaluated (if any), and whether or not the statement
838/// is an integral constant expression (if known).
839struct EvaluatedStmt {
/// Whether this statement was already evaluated.
bool WasEvaluated : 1;

/// Whether this statement is being evaluated.
bool IsEvaluating : 1;

/// Whether this variable is known to have constant initialization. This is
/// currently only computed in C++, for static / thread storage duration
/// variables that might have constant initialization and for variables that
/// are usable in constant expressions.
bool HasConstantInitialization : 1;

/// Whether this variable is known to have constant destruction. That is,
/// whether running the destructor on the initial value is a side-effect
/// (and doesn't inspect any state that might have changed during program
/// execution). This is currently only computed if the destructor is
/// non-trivial.
bool HasConstantDestruction : 1;

/// In C++98, whether the initializer is an ICE. This affects whether the
/// variable is usable in constant expressions.
bool HasICEInit : 1;
bool CheckedForICEInit : 1;

Stmt *Value;
APValue Evaluated;

EvaluatedStmt()
    : WasEvaluated(false), IsEvaluating(false),
      HasConstantInitialization(false), HasConstantDestruction(false),
      HasICEInit(false), CheckedForICEInit(false) {}
871};

873/// Represents a variable declaration or definition.
874class VarDecl : public DeclaratorDecl, public Redeclarable<VarDecl> {
875public:
/// Initialization styles.
enum InitializationStyle {
  /// C-style initialization with assignment
  CInit,

  /// Call-style initialization (C++98)
  CallInit,

  /// Direct list-initialization (C++11)
  ListInit
};

/// Kinds of thread-local storage.
enum TLSKind {
  /// Not a TLS variable.
  TLS_None,

  /// TLS with a known-constant initializer.
  TLS_Static,

  /// TLS with a dynamic initializer.
  TLS_Dynamic
};

/// Return the string used to specify the storage class \p SC.
///
/// It is illegal to call this function with SC == None.
static const char *getStorageClassSpecifierString(StorageClass SC);

905protected:
// A pointer union of Stmt * and EvaluatedStmt *. When an EvaluatedStmt, we
// have allocated the auxiliary struct of information there.
//
// TODO: It is a bit unfortunate to use a PointerUnion inside the VarDecl for
// this as *many* VarDecls are ParmVarDecls that don't have default
// arguments. We could save some space by moving this pointer union to be
// allocated in trailing space when necessary.
using InitType = llvm::PointerUnion<Stmt *, EvaluatedStmt *>;

/// The initializer for this variable or, for a ParmVarDecl, the
/// C++ default argument.
mutable InitType Init;

919private:
friend class ASTDeclReader;
friend class ASTNodeImporter;
friend class StmtIteratorBase;

class VarDeclBitfields {
  friend class ASTDeclReader;
  friend class VarDecl;

  unsigned SClass : 3;
  unsigned TSCSpec : 2;
  unsigned InitStyle : 2;

  /// Whether this variable is an ARC pseudo-__strong variable; see
  /// isARCPseudoStrong() for details.
  unsigned ARCPseudoStrong : 1;
};
enum { NumVarDeclBits = 8 };

938protected:
enum { NumParameterIndexBits = 8 };

enum DefaultArgKind {
  DAK_None,
  DAK_Unparsed,
  DAK_Uninstantiated,
  DAK_Normal
};

enum { NumScopeDepthOrObjCQualsBits = 7 };

class ParmVarDeclBitfields {
  friend class ASTDeclReader;
  friend class ParmVarDecl;

  unsigned : NumVarDeclBits;

  /// Whether this parameter inherits a default argument from a
  /// prior declaration.
  unsigned HasInheritedDefaultArg : 1;

  /// Describes the kind of default argument for this parameter. By default
  /// this is none. If this is normal, then the default argument is stored in
  /// the \c VarDecl initializer expression unless we were unable to parse
  /// (even an invalid) expression for the default argument.
  unsigned DefaultArgKind : 2;

  /// Whether this parameter undergoes K&R argument promotion.
  unsigned IsKNRPromoted : 1;

  /// Whether this parameter is an ObjC method parameter or not.
  unsigned IsObjCMethodParam : 1;

  /// If IsObjCMethodParam, a Decl::ObjCDeclQualifier.
  /// Otherwise, the number of function parameter scopes enclosing
  /// the function parameter scope in which this parameter was
  /// declared.
  unsigned ScopeDepthOrObjCQuals : NumScopeDepthOrObjCQualsBits;

  /// The number of parameters preceding this parameter in the
  /// function parameter scope in which it was declared.
  unsigned ParameterIndex : NumParameterIndexBits;
};

class NonParmVarDeclBitfields {
  friend class ASTDeclReader;
  friend class ImplicitParamDecl;
  friend class VarDecl;

  unsigned : NumVarDeclBits;

  // FIXME: We need something similar to CXXRecordDecl::DefinitionData.
  /// Whether this variable is a definition which was demoted due to
  /// module merge.
  unsigned IsThisDeclarationADemotedDefinition : 1;

  /// Whether this variable is the exception variable in a C++ catch
  /// or an Objective-C @catch statement.
  unsigned ExceptionVar : 1;

  /// Whether this local variable could be allocated in the return
  /// slot of its function, enabling the named return value optimization
  /// (NRVO).
  unsigned NRVOVariable : 1;

  /// Whether this variable is the for-range-declaration in a C++0x
  /// for-range statement.
  unsigned CXXForRangeDecl : 1;

  /// Whether this variable is the for-in loop declaration in Objective-C.
  unsigned ObjCForDecl : 1;

  /// Whether this variable is (C++1z) inline.
  unsigned IsInline : 1;

  /// Whether this variable has (C++1z) inline explicitly specified.
  unsigned IsInlineSpecified : 1;

  /// Whether this variable is (C++0x) constexpr.
  unsigned IsConstexpr : 1;

  /// Whether this variable is the implicit variable for a lambda
  /// init-capture.
  unsigned IsInitCapture : 1;

  /// Whether this local extern variable's previous declaration was
  /// declared in the same block scope. This controls whether we should merge
  /// the type of this declaration with its previous declaration.
  unsigned PreviousDeclInSameBlockScope : 1;

  /// Defines kind of the ImplicitParamDecl: 'this', 'self', 'vtt', '_cmd' or
  /// something else.
  unsigned ImplicitParamKind : 3;

  unsigned EscapingByref : 1;
};

union {
  unsigned AllBits;
  VarDeclBitfields VarDeclBits;
  ParmVarDeclBitfields ParmVarDeclBits;
  NonParmVarDeclBitfields NonParmVarDeclBits;
};

VarDecl(Kind DK, ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
        SourceLocation IdLoc, IdentifierInfo *Id, QualType T,
        TypeSourceInfo *TInfo, StorageClass SC);

using redeclarable_base = Redeclarable<VarDecl>;

VarDecl *getNextRedeclarationImpl() override {
  return getNextRedeclaration();
}

VarDecl *getPreviousDeclImpl() override {
  return getPreviousDecl();
}

VarDecl *getMostRecentDeclImpl() override {
  return getMostRecentDecl();
}

1061public:
using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;
using redeclarable_base::redecls;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::getMostRecentDecl;
using redeclarable_base::isFirstDecl;

static VarDecl *Create(ASTContext &C, DeclContext *DC,
                       SourceLocation StartLoc, SourceLocation IdLoc,
                       IdentifierInfo *Id, QualType T, TypeSourceInfo *TInfo,
                       StorageClass S);

static VarDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

/// Returns the storage class as written in the source. For the
/// computed linkage of symbol, see getLinkage.
StorageClass getStorageClass() const {
  return (StorageClass) VarDeclBits.SClass;
}
void setStorageClass(StorageClass SC);

void setTSCSpec(ThreadStorageClassSpecifier TSC) {
  VarDeclBits.TSCSpec = TSC;
  assert(VarDeclBits.TSCSpec == TSC && "truncation")((void)0);
}
ThreadStorageClassSpecifier getTSCSpec() const {
  return static_cast<ThreadStorageClassSpecifier>(VarDeclBits.TSCSpec);
}
TLSKind getTLSKind() const;

/// Returns true if a variable with function scope is a non-static local
/// variable.
bool hasLocalStorage() const {
  if (getStorageClass() == SC_None) {
    // OpenCL v1.2 s6.5.3: The __constant or constant address space name is
    // used to describe variables allocated in global memory and which are
    // accessed inside a kernel(s) as read-only variables. As such, variables
    // in constant address space cannot have local storage.
    if (getType().getAddressSpace() == LangAS::opencl_constant)
      return false;
    // Second check is for C++11 [dcl.stc]p4.
    return !isFileVarDecl() && getTSCSpec() == TSCS_unspecified;
  }

  // Global Named Register (GNU extension)
  if (getStorageClass() == SC_Register && !isLocalVarDeclOrParm())
    return false;

  // Return true for:  Auto, Register.
  // Return false for: Extern, Static, PrivateExtern, OpenCLWorkGroupLocal.

  return getStorageClass() >= SC_Auto;
}

/// Returns true if a variable with function scope is a static local
/// variable.
bool isStaticLocal() const {
  return (getStorageClass() == SC_Static ||
          // C++11 [dcl.stc]p4
          (getStorageClass() == SC_None && getTSCSpec() == TSCS_thread_local))
    && !isFileVarDecl();
}

/// Returns true if a variable has extern or __private_extern__
/// storage.
bool hasExternalStorage() const {
  return getStorageClass() == SC_Extern ||
         getStorageClass() == SC_PrivateExtern;
}

/// Returns true for all variables that do not have local storage.
///
/// This includes all global variables as well as static variables declared
/// within a function.
bool hasGlobalStorage() const { return !hasLocalStorage(); }

/// Get the storage duration of this variable, per C++ [basic.stc].
StorageDuration getStorageDuration() const {
  return hasLocalStorage() ? SD_Automatic :
         getTSCSpec() ? SD_Thread : SD_Static;
}

/// Compute the language linkage.
LanguageLinkage getLanguageLinkage() const;

/// Determines whether this variable is a variable with external, C linkage.
bool isExternC() const;

/// Determines whether this variable's context is, or is nested within,
/// a C++ extern "C" linkage spec.
bool isInExternCContext() const;

/// Determines whether this variable's context is, or is nested within,
/// a C++ extern "C++" linkage spec.
bool isInExternCXXContext() const;

/// Returns true for local variable declarations other than parameters.
/// Note that this includes static variables inside of functions. It also
/// includes variables inside blocks.
///
///   void foo() { int x; static int y; extern int z; }
bool isLocalVarDecl() const {
  if (getKind() != Decl::Var && getKind() != Decl::Decomposition)
    return false;
  if (const DeclContext *DC = getLexicalDeclContext())
    return DC->getRedeclContext()->isFunctionOrMethod();
  return false;
}

/// Similar to isLocalVarDecl but also includes parameters.
bool isLocalVarDeclOrParm() const {
  return isLocalVarDecl() || getKind() == Decl::ParmVar;
}

/// Similar to isLocalVarDecl, but excludes variables declared in blocks.
bool isFunctionOrMethodVarDecl() const {
  if (getKind() != Decl::Var && getKind() != Decl::Decomposition)
    return false;
  const DeclContext *DC = getLexicalDeclContext()->getRedeclContext();
  return DC->isFunctionOrMethod() && DC->getDeclKind() != Decl::Block;
}

/// Determines whether this is a static data member.
///
/// This will only be true in C++, and applies to, e.g., the
/// variable 'x' in:
/// \code
/// struct S {
///   static int x;
/// };
/// \endcode
bool isStaticDataMember() const {
  // If it wasn't static, it would be a FieldDecl.
  return getKind() != Decl::ParmVar && getDeclContext()->isRecord();
}

VarDecl *getCanonicalDecl() override;
const VarDecl *getCanonicalDecl() const {
  return const_cast<VarDecl*>(this)->getCanonicalDecl();
}

enum DefinitionKind {
  /// This declaration is only a declaration.
  DeclarationOnly,

  /// This declaration is a tentative definition.
  TentativeDefinition,

  /// This declaration is definitely a definition.
  Definition
};

/// Check whether this declaration is a definition. If this could be
/// a tentative definition (in C), don't check whether there's an overriding
/// definition.
DefinitionKind isThisDeclarationADefinition(ASTContext &) const;
DefinitionKind isThisDeclarationADefinition() const {
  return isThisDeclarationADefinition(getASTContext());
}

/// Check whether this variable is defined in this translation unit.
DefinitionKind hasDefinition(ASTContext &) const;
DefinitionKind hasDefinition() const {
  return hasDefinition(getASTContext());
}

/// Get the tentative definition that acts as the real definition in a TU.
/// Returns null if there is a proper definition available.
VarDecl *getActingDefinition();
const VarDecl *getActingDefinition() const {
  return const_cast<VarDecl*>(this)->getActingDefinition();
}

/// Get the real (not just tentative) definition for this declaration.
VarDecl *getDefinition(ASTContext &);
const VarDecl *getDefinition(ASTContext &C) const {
  return const_cast<VarDecl*>(this)->getDefinition(C);
}
VarDecl *getDefinition() {
  return getDefinition(getASTContext());
}
const VarDecl *getDefinition() const {
  return const_cast<VarDecl*>(this)->getDefinition();
}

/// Determine whether this is or was instantiated from an out-of-line
/// definition of a static data member.
bool isOutOfLine() const override;

/// Returns true for file scoped variable declaration.
bool isFileVarDecl() const {
  Kind K = getKind();
  if (K == ParmVar || K == ImplicitParam)
    return false;

  if (getLexicalDeclContext()->getRedeclContext()->isFileContext())
    return true;

  if (isStaticDataMember())
    return true;

  return false;
}

/// Get the initializer for this variable, no matter which
/// declaration it is attached to.
const Expr *getAnyInitializer() const {
  const VarDecl *D;
  return getAnyInitializer(D);
}

/// Get the initializer for this variable, no matter which
/// declaration it is attached to. Also get that declaration.
const Expr *getAnyInitializer(const VarDecl *&D) const;

bool hasInit() const;
const Expr *getInit() const {
  return const_cast<VarDecl *>(this)->getInit();
}
Expr *getInit();

/// Retrieve the address of the initializer expression.
Stmt **getInitAddress();

void setInit(Expr *I);

/// Get the initializing declaration of this variable, if any. This is
/// usually the definition, except that for a static data member it can be
/// the in-class declaration.
VarDecl *getInitializingDeclaration();
const VarDecl *getInitializingDeclaration() const {
  return const_cast<VarDecl *>(this)->getInitializingDeclaration();
}

/// Determine whether this variable's value might be usable in a
/// constant expression, according to the relevant language standard.
/// This only checks properties of the declaration, and does not check
/// whether the initializer is in fact a constant expression.
///
/// This corresponds to C++20 [expr.const]p3's notion of a
/// "potentially-constant" variable.
bool mightBeUsableInConstantExpressions(const ASTContext &C) const;

/// Determine whether this variable's value can be used in a
/// constant expression, according to the relevant language standard,
/// including checking whether it was initialized by a constant expression.
bool isUsableInConstantExpressions(const ASTContext &C) const;

EvaluatedStmt *ensureEvaluatedStmt() const;
EvaluatedStmt *getEvaluatedStmt() const;

/// Attempt to evaluate the value of the initializer attached to this
/// declaration, and produce notes explaining why it cannot be evaluated.
/// Returns a pointer to the value if evaluation succeeded, 0 otherwise.
APValue *evaluateValue() const;

1323private:
APValue *evaluateValueImpl(SmallVectorImpl<PartialDiagnosticAt> &Notes,
                           bool IsConstantInitialization) const;

1327public:
/// Return the already-evaluated value of this variable's
/// initializer, or NULL if the value is not yet known. Returns pointer
/// to untyped APValue if the value could not be evaluated.
APValue *getEvaluatedValue() const;

/// Evaluate the destruction of this variable to determine if it constitutes
/// constant destruction.
///
/// \pre hasConstantInitialization()
/// \return \c true if this variable has constant destruction, \c false if
///         not.
bool evaluateDestruction(SmallVectorImpl<PartialDiagnosticAt> &Notes) const;

/// Determine whether this variable has constant initialization.
///
/// This is only set in two cases: when the language semantics require
/// constant initialization (globals in C and some globals in C++), and when
/// the variable is usable in constant expressions (constexpr, const int, and
/// reference variables in C++).
bool hasConstantInitialization() const;

/// Determine whether the initializer of this variable is an integer constant
/// expression. For use in C++98, where this affects whether the variable is
/// usable in constant expressions.
bool hasICEInitializer(const ASTContext &Context) const;

/// Evaluate the initializer of this variable to determine whether it's a
/// constant initializer. Should only be called once, after completing the
/// definition of the variable.
bool checkForConstantInitialization(
    SmallVectorImpl<PartialDiagnosticAt> &Notes) const;

void setInitStyle(InitializationStyle Style) {
  VarDeclBits.InitStyle = Style;
}

/// The style of initialization for this declaration.
///
/// C-style initialization is "int x = 1;". Call-style initialization is
/// a C++98 direct-initializer, e.g. "int x(1);". The Init expression will be
/// the expression inside the parens or a "ClassType(a,b,c)" class constructor
/// expression for class types. List-style initialization is C++11 syntax,
/// e.g. "int x{1};". Clients can distinguish between different forms of
/// initialization by checking this value. In particular, "int x = {1};" is
/// C-style, "int x({1})" is call-style, and "int x{1};" is list-style; the
/// Init expression in all three cases is an InitListExpr.
InitializationStyle getInitStyle() const {
  return static_cast<InitializationStyle>(VarDeclBits.InitStyle);
}

/// Whether the initializer is a direct-initializer (list or call).
bool isDirectInit() const {
  return getInitStyle() != CInit;
}

/// If this definition should pretend to be a declaration.
bool isThisDeclarationADemotedDefinition() const {
  return isa<ParmVarDecl>(this) ? false :
    NonParmVarDeclBits.IsThisDeclarationADemotedDefinition;
}

/// This is a definition which should be demoted to a declaration.
///
/// In some cases (mostly module merging) we can end up with two visible
/// definitions one of which needs to be demoted to a declaration to keep
/// the AST invariants.
void demoteThisDefinitionToDeclaration() {
  assert(isThisDeclarationADefinition() && "Not a definition!")((void)0);
  assert(!isa<ParmVarDecl>(this) && "Cannot demote ParmVarDecls!")((void)0);
  NonParmVarDeclBits.IsThisDeclarationADemotedDefinition = 1;
}

/// Determine whether this variable is the exception variable in a
/// C++ catch statememt or an Objective-C \@catch statement.
bool isExceptionVariable() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.ExceptionVar;
}
void setExceptionVariable(bool EV) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.ExceptionVar = EV;
}

/// Determine whether this local variable can be used with the named
/// return value optimization (NRVO).
///
/// The named return value optimization (NRVO) works by marking certain
/// non-volatile local variables of class type as NRVO objects. These
/// locals can be allocated within the return slot of their containing
/// function, in which case there is no need to copy the object to the
/// return slot when returning from the function. Within the function body,
/// each return that returns the NRVO object will have this variable as its
/// NRVO candidate.
bool isNRVOVariable() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.NRVOVariable;
}
void setNRVOVariable(bool NRVO) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.NRVOVariable = NRVO;
}

/// Determine whether this variable is the for-range-declaration in
/// a C++0x for-range statement.
bool isCXXForRangeDecl() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.CXXForRangeDecl;
}
void setCXXForRangeDecl(bool FRD) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.CXXForRangeDecl = FRD;
}

/// Determine whether this variable is a for-loop declaration for a
/// for-in statement in Objective-C.
bool isObjCForDecl() const {
  return NonParmVarDeclBits.ObjCForDecl;
}

void setObjCForDecl(bool FRD) {
  NonParmVarDeclBits.ObjCForDecl = FRD;
}

/// Determine whether this variable is an ARC pseudo-__strong variable. A
/// pseudo-__strong variable has a __strong-qualified type but does not
/// actually retain the object written into it. Generally such variables are
/// also 'const' for safety. There are 3 cases where this will be set, 1) if
/// the variable is annotated with the objc_externally_retained attribute, 2)
/// if its 'self' in a non-init method, or 3) if its the variable in an for-in
/// loop.
bool isARCPseudoStrong() const { return VarDeclBits.ARCPseudoStrong; }
void setARCPseudoStrong(bool PS) { VarDeclBits.ARCPseudoStrong = PS; }

/// Whether this variable is (C++1z) inline.
bool isInline() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.IsInline;
}
bool isInlineSpecified() const {
  return isa<ParmVarDecl>(this) ? false
                                : NonParmVarDeclBits.IsInlineSpecified;
}
void setInlineSpecified() {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.IsInline = true;
  NonParmVarDeclBits.IsInlineSpecified = true;
}
void setImplicitlyInline() {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.IsInline = true;
}

/// Whether this variable is (C++11) constexpr.
bool isConstexpr() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.IsConstexpr;
}
void setConstexpr(bool IC) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.IsConstexpr = IC;
}

/// Whether this variable is the implicit variable for a lambda init-capture.
bool isInitCapture() const {
  return isa<ParmVarDecl>(this) ? false : NonParmVarDeclBits.IsInitCapture;
}
void setInitCapture(bool IC) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.IsInitCapture = IC;
}

/// Determine whether this variable is actually a function parameter pack or
/// init-capture pack.
bool isParameterPack() const;

/// Whether this local extern variable declaration's previous declaration
/// was declared in the same block scope. Only correct in C++.
bool isPreviousDeclInSameBlockScope() const {
  return isa<ParmVarDecl>(this)
             ? false
             : NonParmVarDeclBits.PreviousDeclInSameBlockScope;
}
void setPreviousDeclInSameBlockScope(bool Same) {
  assert(!isa<ParmVarDecl>(this))((void)0);
  NonParmVarDeclBits.PreviousDeclInSameBlockScope = Same;
}

/// Indicates the capture is a __block variable that is captured by a block
/// that can potentially escape (a block for which BlockDecl::doesNotEscape
/// returns false).
bool isEscapingByref() const;

/// Indicates the capture is a __block variable that is never captured by an
/// escaping block.
bool isNonEscapingByref() const;

void setEscapingByref() {
  NonParmVarDeclBits.EscapingByref = true;
}

/// Determines if this variable's alignment is dependent.
bool hasDependentAlignment() const;

/// Retrieve the variable declaration from which this variable could
/// be instantiated, if it is an instantiation (rather than a non-template).
VarDecl *getTemplateInstantiationPattern() const;

/// If this variable is an instantiated static data member of a
/// class template specialization, returns the templated static data member
/// from which it was instantiated.
VarDecl *getInstantiatedFromStaticDataMember() const;

/// If this variable is an instantiation of a variable template or a
/// static data member of a class template, determine what kind of
/// template specialization or instantiation this is.
TemplateSpecializationKind getTemplateSpecializationKind() const;

/// Get the template specialization kind of this variable for the purposes of
/// template instantiation. This differs from getTemplateSpecializationKind()
/// for an instantiation of a class-scope explicit specialization.
TemplateSpecializationKind
getTemplateSpecializationKindForInstantiation() const;

/// If this variable is an instantiation of a variable template or a
/// static data member of a class template, determine its point of
/// instantiation.
SourceLocation getPointOfInstantiation() const;

/// If this variable is an instantiation of a static data member of a
/// class template specialization, retrieves the member specialization
/// information.
MemberSpecializationInfo *getMemberSpecializationInfo() const;

/// For a static data member that was instantiated from a static
/// data member of a class template, set the template specialiation kind.
void setTemplateSpecializationKind(TemplateSpecializationKind TSK,
                      SourceLocation PointOfInstantiation = SourceLocation());

/// Specify that this variable is an instantiation of the
/// static data member VD.
void setInstantiationOfStaticDataMember(VarDecl *VD,
                                        TemplateSpecializationKind TSK);

/// Retrieves the variable template that is described by this
/// variable declaration.
///
/// Every variable template is represented as a VarTemplateDecl and a
/// VarDecl. The former contains template properties (such as
/// the template parameter lists) while the latter contains the
/// actual description of the template's
/// contents. VarTemplateDecl::getTemplatedDecl() retrieves the
/// VarDecl that from a VarTemplateDecl, while
/// getDescribedVarTemplate() retrieves the VarTemplateDecl from
/// a VarDecl.
VarTemplateDecl *getDescribedVarTemplate() const;

void setDescribedVarTemplate(VarTemplateDecl *Template);

// Is this variable known to have a definition somewhere in the complete
// program? This may be true even if the declaration has internal linkage and
// has no definition within this source file.
bool isKnownToBeDefined() const;

/// Is destruction of this variable entirely suppressed? If so, the variable
/// need not have a usable destructor at all.
bool isNoDestroy(const ASTContext &) const;

/// Would the destruction of this variable have any effect, and if so, what
/// kind?
QualType::DestructionKind needsDestruction(const ASTContext &Ctx) const;

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstVar && K <= lastVar; }
1597};

1599class ImplicitParamDecl : public VarDecl {
void anchor() override;

1602public:
/// Defines the kind of the implicit parameter: is this an implicit parameter
/// with pointer to 'this', 'self', '_cmd', virtual table pointers, captured
/// context or something else.
enum ImplicitParamKind : unsigned {
  /// Parameter for Objective-C 'self' argument
  ObjCSelf,

  /// Parameter for Objective-C '_cmd' argument
  ObjCCmd,

  /// Parameter for C++ 'this' argument
  CXXThis,

  /// Parameter for C++ virtual table pointers
  CXXVTT,

  /// Parameter for captured context
  CapturedContext,

  /// Other implicit parameter
  Other,
};

/// Create implicit parameter.
static ImplicitParamDecl *Create(ASTContext &C, DeclContext *DC,
                                 SourceLocation IdLoc, IdentifierInfo *Id,
                                 QualType T, ImplicitParamKind ParamKind);
static ImplicitParamDecl *Create(ASTContext &C, QualType T,
                                 ImplicitParamKind ParamKind);

static ImplicitParamDecl *CreateDeserialized(ASTContext &C, unsigned ID);

ImplicitParamDecl(ASTContext &C, DeclContext *DC, SourceLocation IdLoc,
                  IdentifierInfo *Id, QualType Type,
                  ImplicitParamKind ParamKind)
    : VarDecl(ImplicitParam, C, DC, IdLoc, IdLoc, Id, Type,
              /*TInfo=*/nullptr, SC_None) {
  NonParmVarDeclBits.ImplicitParamKind = ParamKind;
  setImplicit();
}

ImplicitParamDecl(ASTContext &C, QualType Type, ImplicitParamKind ParamKind)
    : VarDecl(ImplicitParam, C, /*DC=*/nullptr, SourceLocation(),
              SourceLocation(), /*Id=*/nullptr, Type,
              /*TInfo=*/nullptr, SC_None) {
  NonParmVarDeclBits.ImplicitParamKind = ParamKind;
  setImplicit();
}

/// Returns the implicit parameter kind.
ImplicitParamKind getParameterKind() const {
  return static_cast<ImplicitParamKind>(NonParmVarDeclBits.ImplicitParamKind);
}

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == ImplicitParam; }
1660};

1662/// Represents a parameter to a function.
1663class ParmVarDecl : public VarDecl {
1664public:
enum { MaxFunctionScopeDepth = 255 };
enum { MaxFunctionScopeIndex = 255 };

1668protected:
ParmVarDecl(Kind DK, ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
            SourceLocation IdLoc, IdentifierInfo *Id, QualType T,
            TypeSourceInfo *TInfo, StorageClass S, Expr *DefArg)
    : VarDecl(DK, C, DC, StartLoc, IdLoc, Id, T, TInfo, S) {
  assert(ParmVarDeclBits.HasInheritedDefaultArg == false)((void)0);
  assert(ParmVarDeclBits.DefaultArgKind == DAK_None)((void)0);
  assert(ParmVarDeclBits.IsKNRPromoted == false)((void)0);
  assert(ParmVarDeclBits.IsObjCMethodParam == false)((void)0);
  setDefaultArg(DefArg);
}

1680public:
static ParmVarDecl *Create(ASTContext &C, DeclContext *DC,
                           SourceLocation StartLoc,
                           SourceLocation IdLoc, IdentifierInfo *Id,
                           QualType T, TypeSourceInfo *TInfo,
                           StorageClass S, Expr *DefArg);

static ParmVarDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

void setObjCMethodScopeInfo(unsigned parameterIndex) {
  ParmVarDeclBits.IsObjCMethodParam = true;
  setParameterIndex(parameterIndex);
}

void setScopeInfo(unsigned scopeDepth, unsigned parameterIndex) {
  assert(!ParmVarDeclBits.IsObjCMethodParam)((void)0);

  ParmVarDeclBits.ScopeDepthOrObjCQuals = scopeDepth;
  assert(ParmVarDeclBits.ScopeDepthOrObjCQuals == scopeDepth((void)0)
         && "truncation!")((void)0);

  setParameterIndex(parameterIndex);
}

bool isObjCMethodParameter() const {
  return ParmVarDeclBits.IsObjCMethodParam;
}

/// Determines whether this parameter is destroyed in the callee function.
bool isDestroyedInCallee() const;

unsigned getFunctionScopeDepth() const {
  if (ParmVarDeclBits.IsObjCMethodParam) return 0;
  return ParmVarDeclBits.ScopeDepthOrObjCQuals;
}

static constexpr unsigned getMaxFunctionScopeDepth() {
  return (1u << NumScopeDepthOrObjCQualsBits) - 1;
}

/// Returns the index of this parameter in its prototype or method scope.
unsigned getFunctionScopeIndex() const {
  return getParameterIndex();
}

ObjCDeclQualifier getObjCDeclQualifier() const {
  if (!ParmVarDeclBits.IsObjCMethodParam) return OBJC_TQ_None;
  return ObjCDeclQualifier(ParmVarDeclBits.ScopeDepthOrObjCQuals);
}
void setObjCDeclQualifier(ObjCDeclQualifier QTVal) {
  assert(ParmVarDeclBits.IsObjCMethodParam)((void)0);
  ParmVarDeclBits.ScopeDepthOrObjCQuals = QTVal;
}

/// True if the value passed to this parameter must undergo
/// K&R-style default argument promotion:
///
/// C99 6.5.2.2.
///   If the expression that denotes the called function has a type
///   that does not include a prototype, the integer promotions are
///   performed on each argument, and arguments that have type float
///   are promoted to double.
bool isKNRPromoted() const {
  return ParmVarDeclBits.IsKNRPromoted;
}
void setKNRPromoted(bool promoted) {
  ParmVarDeclBits.IsKNRPromoted = promoted;
}

Expr *getDefaultArg();
const Expr *getDefaultArg() const {
  return const_cast<ParmVarDecl *>(this)->getDefaultArg();
}

void setDefaultArg(Expr *defarg);

/// Retrieve the source range that covers the entire default
/// argument.
SourceRange getDefaultArgRange() const;
void setUninstantiatedDefaultArg(Expr *arg);
Expr *getUninstantiatedDefaultArg();
const Expr *getUninstantiatedDefaultArg() const {
  return const_cast<ParmVarDecl *>(this)->getUninstantiatedDefaultArg();
}

/// Determines whether this parameter has a default argument,
/// either parsed or not.
bool hasDefaultArg() const;

/// Determines whether this parameter has a default argument that has not
/// yet been parsed. This will occur during the processing of a C++ class
/// whose member functions have default arguments, e.g.,
/// @code
///   class X {
///   public:
///     void f(int x = 17); // x has an unparsed default argument now
///   }; // x has a regular default argument now
/// @endcode
bool hasUnparsedDefaultArg() const {
  return ParmVarDeclBits.DefaultArgKind == DAK_Unparsed;
}

bool hasUninstantiatedDefaultArg() const {
  return ParmVarDeclBits.DefaultArgKind == DAK_Uninstantiated;
}

/// Specify that this parameter has an unparsed default argument.
/// The argument will be replaced with a real default argument via
/// setDefaultArg when the class definition enclosing the function
/// declaration that owns this default argument is completed.
void setUnparsedDefaultArg() {
  ParmVarDeclBits.DefaultArgKind = DAK_Unparsed;
}

bool hasInheritedDefaultArg() const {
  return ParmVarDeclBits.HasInheritedDefaultArg;
}

void setHasInheritedDefaultArg(bool I = true) {
  ParmVarDeclBits.HasInheritedDefaultArg = I;
}

QualType getOriginalType() const;

/// Sets the function declaration that owns this
/// ParmVarDecl. Since ParmVarDecls are often created before the
/// FunctionDecls that own them, this routine is required to update
/// the DeclContext appropriately.
void setOwningFunction(DeclContext *FD) { setDeclContext(FD); }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == ParmVar; }

1816private:
enum { ParameterIndexSentinel = (1 << NumParameterIndexBits) - 1 };

void setParameterIndex(unsigned parameterIndex) {
  if (parameterIndex >= ParameterIndexSentinel) {
    setParameterIndexLarge(parameterIndex);
    return;
  }

  ParmVarDeclBits.ParameterIndex = parameterIndex;
  assert(ParmVarDeclBits.ParameterIndex == parameterIndex && "truncation!")((void)0);
}
unsigned getParameterIndex() const {
  unsigned d = ParmVarDeclBits.ParameterIndex;
  return d == ParameterIndexSentinel ? getParameterIndexLarge() : d;
}

void setParameterIndexLarge(unsigned parameterIndex);
unsigned getParameterIndexLarge() const;
1835};

1837enum class MultiVersionKind {
None,
Target,
CPUSpecific,
CPUDispatch
1842};

1844/// Represents a function declaration or definition.
1845///
1846/// Since a given function can be declared several times in a program,
1847/// there may be several FunctionDecls that correspond to that
1848/// function. Only one of those FunctionDecls will be found when
1849/// traversing the list of declarations in the context of the
1850/// FunctionDecl (e.g., the translation unit); this FunctionDecl
1851/// contains all of the information known about the function. Other,
1852/// previous declarations of the function are available via the
1853/// getPreviousDecl() chain.
1854class FunctionDecl : public DeclaratorDecl,
                   public DeclContext,
                   public Redeclarable<FunctionDecl> {
// This class stores some data in DeclContext::FunctionDeclBits
// to save some space. Use the provided accessors to access it.
1859public:
/// The kind of templated function a FunctionDecl can be.
enum TemplatedKind {
  // Not templated.
  TK_NonTemplate,
  // The pattern in a function template declaration.
  TK_FunctionTemplate,
  // A non-template function that is an instantiation or explicit
  // specialization of a member of a templated class.
  TK_MemberSpecialization,
  // An instantiation or explicit specialization of a function template.
  // Note: this might have been instantiated from a templated class if it
  // is a class-scope explicit specialization.
  TK_FunctionTemplateSpecialization,
  // A function template specialization that hasn't yet been resolved to a
  // particular specialized function template.
  TK_DependentFunctionTemplateSpecialization
};

/// Stashed information about a defaulted function definition whose body has
/// not yet been lazily generated.
class DefaultedFunctionInfo final
    : llvm::TrailingObjects<DefaultedFunctionInfo, DeclAccessPair> {
  friend TrailingObjects;
  unsigned NumLookups;

public:
  static DefaultedFunctionInfo *Create(ASTContext &Context,
                                       ArrayRef<DeclAccessPair> Lookups);
  /// Get the unqualified lookup results that should be used in this
  /// defaulted function definition.
  ArrayRef<DeclAccessPair> getUnqualifiedLookups() const {
    return {getTrailingObjects<DeclAccessPair>(), NumLookups};
  }
};

1895private:
/// A new[]'d array of pointers to VarDecls for the formal
/// parameters of this function.  This is null if a prototype or if there are
/// no formals.
ParmVarDecl **ParamInfo = nullptr;

/// The active member of this union is determined by
/// FunctionDeclBits.HasDefaultedFunctionInfo.
union {
  /// The body of the function.
  LazyDeclStmtPtr Body;
  /// Information about a future defaulted function definition.
  DefaultedFunctionInfo *DefaultedInfo;
};

unsigned ODRHash;

/// End part of this FunctionDecl's source range.
///
/// We could compute the full range in getSourceRange(). However, when we're
/// dealing with a function definition deserialized from a PCH/AST file,
/// we can only compute the full range once the function body has been
/// de-serialized, so it's far better to have the (sometimes-redundant)
/// EndRangeLoc.
SourceLocation EndRangeLoc;

/// The template or declaration that this declaration
/// describes or was instantiated from, respectively.
///
/// For non-templates, this value will be NULL. For function
/// declarations that describe a function template, this will be a
/// pointer to a FunctionTemplateDecl. For member functions
/// of class template specializations, this will be a MemberSpecializationInfo
/// pointer containing information about the specialization.
/// For function template specializations, this will be a
/// FunctionTemplateSpecializationInfo, which contains information about
/// the template being specialized and the template arguments involved in
/// that specialization.
llvm::PointerUnion<FunctionTemplateDecl *,
                   MemberSpecializationInfo *,
                   FunctionTemplateSpecializationInfo *,
                   DependentFunctionTemplateSpecializationInfo *>
  TemplateOrSpecialization;

/// Provides source/type location info for the declaration name embedded in
/// the DeclaratorDecl base class.
DeclarationNameLoc DNLoc;

/// Specify that this function declaration is actually a function
/// template specialization.
///
/// \param C the ASTContext.
///
/// \param Template the function template that this function template
/// specialization specializes.
///
/// \param TemplateArgs the template arguments that produced this
/// function template specialization from the template.
///
/// \param InsertPos If non-NULL, the position in the function template
/// specialization set where the function template specialization data will
/// be inserted.
///
/// \param TSK the kind of template specialization this is.
///
/// \param TemplateArgsAsWritten location info of template arguments.
///
/// \param PointOfInstantiation point at which the function template
/// specialization was first instantiated.
void setFunctionTemplateSpecialization(ASTContext &C,
                                       FunctionTemplateDecl *Template,
                                     const TemplateArgumentList *TemplateArgs,
                                       void *InsertPos,
                                       TemplateSpecializationKind TSK,
                        const TemplateArgumentListInfo *TemplateArgsAsWritten,
                                       SourceLocation PointOfInstantiation);

/// Specify that this record is an instantiation of the
/// member function FD.
void setInstantiationOfMemberFunction(ASTContext &C, FunctionDecl *FD,
                                      TemplateSpecializationKind TSK);

void setParams(ASTContext &C, ArrayRef<ParmVarDecl *> NewParamInfo);

// This is unfortunately needed because ASTDeclWriter::VisitFunctionDecl
// need to access this bit but we want to avoid making ASTDeclWriter
// a friend of FunctionDeclBitfields just for this.
bool isDeletedBit() const { return FunctionDeclBits.IsDeleted; }

/// Whether an ODRHash has been stored.
bool hasODRHash() const { return FunctionDeclBits.HasODRHash; }

/// State that an ODRHash has been stored.
void setHasODRHash(bool B = true) { FunctionDeclBits.HasODRHash = B; }

1990protected:
FunctionDecl(Kind DK, ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
             const DeclarationNameInfo &NameInfo, QualType T,
             TypeSourceInfo *TInfo, StorageClass S, bool isInlineSpecified,
             ConstexprSpecKind ConstexprKind,
             Expr *TrailingRequiresClause = nullptr);

using redeclarable_base = Redeclarable<FunctionDecl>;

FunctionDecl *getNextRedeclarationImpl() override {
  return getNextRedeclaration();
}

FunctionDecl *getPreviousDeclImpl() override {
  return getPreviousDecl();
}

FunctionDecl *getMostRecentDeclImpl() override {
  return getMostRecentDecl();
}

2011public:
friend class ASTDeclReader;
friend class ASTDeclWriter;

using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;
using redeclarable_base::redecls;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::getMostRecentDecl;
using redeclarable_base::isFirstDecl;

static FunctionDecl *
Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
       SourceLocation NLoc, DeclarationName N, QualType T,
       TypeSourceInfo *TInfo, StorageClass SC, bool isInlineSpecified = false,
       bool hasWrittenPrototype = true,
       ConstexprSpecKind ConstexprKind = ConstexprSpecKind::Unspecified,
       Expr *TrailingRequiresClause = nullptr) {
  DeclarationNameInfo NameInfo(N, NLoc);
  return FunctionDecl::Create(C, DC, StartLoc, NameInfo, T, TInfo, SC,
                              isInlineSpecified, hasWrittenPrototype,
                              ConstexprKind, TrailingRequiresClause);
}

static FunctionDecl *Create(ASTContext &C, DeclContext *DC,
                            SourceLocation StartLoc,
                            const DeclarationNameInfo &NameInfo, QualType T,
                            TypeSourceInfo *TInfo, StorageClass SC,
                            bool isInlineSpecified, bool hasWrittenPrototype,
                            ConstexprSpecKind ConstexprKind,
                            Expr *TrailingRequiresClause);

static FunctionDecl *CreateDeserialized(ASTContext &C, unsigned ID);

DeclarationNameInfo getNameInfo() const {
  return DeclarationNameInfo(getDeclName(), getLocation(), DNLoc);
}

void getNameForDiagnostic(raw_ostream &OS, const PrintingPolicy &Policy,
                          bool Qualified) const override;

void setRangeEnd(SourceLocation E) { EndRangeLoc = E; }

/// Returns the location of the ellipsis of a variadic function.
SourceLocation getEllipsisLoc() const {
  const auto *FPT = getType()->getAs<FunctionProtoType>();
  if (FPT && FPT->isVariadic())
    return FPT->getEllipsisLoc();
  return SourceLocation();
}

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

// Function definitions.
//
// A function declaration may be:
// - a non defining declaration,
// - a definition. A function may be defined because:
//   - it has a body, or will have it in the case of late parsing.
//   - it has an uninstantiated body. The body does not exist because the
//     function is not used yet, but the declaration is considered a
//     definition and does not allow other definition of this function.
//   - it does not have a user specified body, but it does not allow
//     redefinition, because it is deleted/defaulted or is defined through
//     some other mechanism (alias, ifunc).

/// Returns true if the function has a body.
///
/// The function body might be in any of the (re-)declarations of this
/// function. The variant that accepts a FunctionDecl pointer will set that
/// function declaration to the actual declaration containing the body (if
/// there is one).
bool hasBody(const FunctionDecl *&Definition) const;

bool hasBody() const override {
  const FunctionDecl* Definition;
  return hasBody(Definition);
}

/// Returns whether the function has a trivial body that does not require any
/// specific codegen.
bool hasTrivialBody() const;

/// Returns true if the function has a definition that does not need to be
/// instantiated.
///
/// The variant that accepts a FunctionDecl pointer will set that function
/// declaration to the declaration that is a definition (if there is one).
///
/// \param CheckForPendingFriendDefinition If \c true, also check for friend
///        declarations that were instantiataed from function definitions.
///        Such a declaration behaves as if it is a definition for the
///        purpose of redefinition checking, but isn't actually a "real"
///        definition until its body is instantiated.
bool isDefined(const FunctionDecl *&Definition,
               bool CheckForPendingFriendDefinition = false) const;

bool isDefined() const {
  const FunctionDecl* Definition;
  return isDefined(Definition);
}

/// Get the definition for this declaration.
FunctionDecl *getDefinition() {
  const FunctionDecl *Definition;
  if (isDefined(Definition))
    return const_cast<FunctionDecl *>(Definition);
  return nullptr;
}
const FunctionDecl *getDefinition() const {
  return const_cast<FunctionDecl *>(this)->getDefinition();
}

/// Retrieve the body (definition) of the function. The function body might be
/// in any of the (re-)declarations of this function. The variant that accepts
/// a FunctionDecl pointer will set that function declaration to the actual
/// declaration containing the body (if there is one).
/// NOTE: For checking if there is a body, use hasBody() instead, to avoid
/// unnecessary AST de-serialization of the body.
Stmt *getBody(const FunctionDecl *&Definition) const;

Stmt *getBody() const override {
  const FunctionDecl* Definition;
  return getBody(Definition);
}

/// Returns whether this specific declaration of the function is also a
/// definition that does not contain uninstantiated body.
///
/// This does not determine whether the function has been defined (e.g., in a
/// previous definition); for that information, use isDefined.
///
/// Note: the function declaration does not become a definition until the
/// parser reaches the definition, if called before, this function will return
/// `false`.
bool isThisDeclarationADefinition() const {
  return isDeletedAsWritten() || isDefaulted() ||
         doesThisDeclarationHaveABody() || hasSkippedBody() ||
         willHaveBody() || hasDefiningAttr();
}

/// Determine whether this specific declaration of the function is a friend
/// declaration that was instantiated from a function definition. Such
/// declarations behave like definitions in some contexts.
bool isThisDeclarationInstantiatedFromAFriendDefinition() const;

/// Returns whether this specific declaration of the function has a body.
bool doesThisDeclarationHaveABody() const {
  return (!FunctionDeclBits.HasDefaultedFunctionInfo && Body) ||
         isLateTemplateParsed();
}

void setBody(Stmt *B);
void setLazyBody(uint64_t Offset) {
  FunctionDeclBits.HasDefaultedFunctionInfo = false;
  Body = LazyDeclStmtPtr(Offset);
}

void setDefaultedFunctionInfo(DefaultedFunctionInfo *Info);
DefaultedFunctionInfo *getDefaultedFunctionInfo() const;

/// Whether this function is variadic.
bool isVariadic() const;

/// Whether this function is marked as virtual explicitly.
bool isVirtualAsWritten() const {
  return FunctionDeclBits.IsVirtualAsWritten;
}

/// State that this function is marked as virtual explicitly.
void setVirtualAsWritten(bool V) { FunctionDeclBits.IsVirtualAsWritten = V; }

/// Whether this virtual function is pure, i.e. makes the containing class
/// abstract.
bool isPure() const { return FunctionDeclBits.IsPure; }
void setPure(bool P = true);

/// Whether this templated function will be late parsed.
bool isLateTemplateParsed() const {
  return FunctionDeclBits.IsLateTemplateParsed;
}

/// State that this templated function will be late parsed.
void setLateTemplateParsed(bool ILT = true) {
  FunctionDeclBits.IsLateTemplateParsed = ILT;
}

/// Whether this function is "trivial" in some specialized C++ senses.
/// Can only be true for default constructors, copy constructors,
/// copy assignment operators, and destructors.  Not meaningful until
/// the class has been fully built by Sema.
bool isTrivial() const { return FunctionDeclBits.IsTrivial; }
void setTrivial(bool IT) { FunctionDeclBits.IsTrivial = IT; }

bool isTrivialForCall() const { return FunctionDeclBits.IsTrivialForCall; }
void setTrivialForCall(bool IT) { FunctionDeclBits.IsTrivialForCall = IT; }

/// Whether this function is defaulted. Valid for e.g.
/// special member functions, defaulted comparisions (not methods!).
bool isDefaulted() const { return FunctionDeclBits.IsDefaulted; }
void setDefaulted(bool D = true) { FunctionDeclBits.IsDefaulted = D; }

/// Whether this function is explicitly defaulted.
bool isExplicitlyDefaulted() const {
  return FunctionDeclBits.IsExplicitlyDefaulted;
}

/// State that this function is explicitly defaulted.
void setExplicitlyDefaulted(bool ED = true) {
  FunctionDeclBits.IsExplicitlyDefaulted = ED;
}

/// True if this method is user-declared and was not
/// deleted or defaulted on its first declaration.
bool isUserProvided() const {
  auto *DeclAsWritten = this;
  if (FunctionDecl *Pattern = getTemplateInstantiationPattern())
    DeclAsWritten = Pattern;
  return !(DeclAsWritten->isDeleted() ||
           DeclAsWritten->getCanonicalDecl()->isDefaulted());
}

/// Whether falling off this function implicitly returns null/zero.
/// If a more specific implicit return value is required, front-ends
/// should synthesize the appropriate return statements.
bool hasImplicitReturnZero() const {
  return FunctionDeclBits.HasImplicitReturnZero;
}

/// State that falling off this function implicitly returns null/zero.
/// If a more specific implicit return value is required, front-ends
/// should synthesize the appropriate return statements.
void setHasImplicitReturnZero(bool IRZ) {
  FunctionDeclBits.HasImplicitReturnZero = IRZ;
}

/// Whether this function has a prototype, either because one
/// was explicitly written or because it was "inherited" by merging
/// a declaration without a prototype with a declaration that has a
/// prototype.
bool hasPrototype() const {
  return hasWrittenPrototype() || hasInheritedPrototype();
}

/// Whether this function has a written prototype.
bool hasWrittenPrototype() const {
  return FunctionDeclBits.HasWrittenPrototype;
}

/// State that this function has a written prototype.
void setHasWrittenPrototype(bool P = true) {
  FunctionDeclBits.HasWrittenPrototype = P;
}

/// Whether this function inherited its prototype from a
/// previous declaration.
bool hasInheritedPrototype() const {
  return FunctionDeclBits.HasInheritedPrototype;
}

/// State that this function inherited its prototype from a
/// previous declaration.
void setHasInheritedPrototype(bool P = true) {
  FunctionDeclBits.HasInheritedPrototype = P;
}

/// Whether this is a (C++11) constexpr function or constexpr constructor.
bool isConstexpr() const {
  return getConstexprKind() != ConstexprSpecKind::Unspecified;
}
void setConstexprKind(ConstexprSpecKind CSK) {
  FunctionDeclBits.ConstexprKind = static_cast<uint64_t>(CSK);
}
ConstexprSpecKind getConstexprKind() const {
  return static_cast<ConstexprSpecKind>(FunctionDeclBits.ConstexprKind);
}
bool isConstexprSpecified() const {
  return getConstexprKind() == ConstexprSpecKind::Constexpr;
}
bool isConsteval() const {
  return getConstexprKind() == ConstexprSpecKind::Consteval;
}

/// Whether the instantiation of this function is pending.
/// This bit is set when the decision to instantiate this function is made
/// and unset if and when the function body is created. That leaves out
/// cases where instantiation did not happen because the template definition
/// was not seen in this TU. This bit remains set in those cases, under the
/// assumption that the instantiation will happen in some other TU.
bool instantiationIsPending() const {
  return FunctionDeclBits.InstantiationIsPending;
}

/// State that the instantiation of this function is pending.
/// (see instantiationIsPending)
void setInstantiationIsPending(bool IC) {
  FunctionDeclBits.InstantiationIsPending = IC;
}

/// Indicates the function uses __try.
bool usesSEHTry() const { return FunctionDeclBits.UsesSEHTry; }
void setUsesSEHTry(bool UST) { FunctionDeclBits.UsesSEHTry = UST; }

/// Whether this function has been deleted.
///
/// A function that is "deleted" (via the C++0x "= delete" syntax)
/// acts like a normal function, except that it cannot actually be
/// called or have its address taken. Deleted functions are
/// typically used in C++ overload resolution to attract arguments
/// whose type or lvalue/rvalue-ness would permit the use of a
/// different overload that would behave incorrectly. For example,
/// one might use deleted functions to ban implicit conversion from
/// a floating-point number to an Integer type:
///
/// @code
/// struct Integer {
///   Integer(long); // construct from a long
///   Integer(double) = delete; // no construction from float or double
///   Integer(long double) = delete; // no construction from long double
/// };
/// @endcode
// If a function is deleted, its first declaration must be.
bool isDeleted() const {
  return getCanonicalDecl()->FunctionDeclBits.IsDeleted;
}

bool isDeletedAsWritten() const {
  return FunctionDeclBits.IsDeleted && !isDefaulted();
}

void setDeletedAsWritten(bool D = true) { FunctionDeclBits.IsDeleted = D; }

/// Determines whether this function is "main", which is the
/// entry point into an executable program.
bool isMain() const;

/// Determines whether this function is a MSVCRT user defined entry
/// point.
bool isMSVCRTEntryPoint() const;

/// Determines whether this operator new or delete is one
/// of the reserved global placement operators:
///    void *operator new(size_t, void *);
///    void *operator new[](size_t, void *);
///    void operator delete(void *, void *);
///    void operator delete[](void *, void *);
/// These functions have special behavior under [new.delete.placement]:
///    These functions are reserved, a C++ program may not define
///    functions that displace the versions in the Standard C++ library.
///    The provisions of [basic.stc.dynamic] do not apply to these
///    reserved placement forms of operator new and operator delete.
///
/// This function must be an allocation or deallocation function.
bool isReservedGlobalPlacementOperator() const;

/// Determines whether this function is one of the replaceable
/// global allocation functions:
///    void *operator new(size_t);
///    void *operator new(size_t, const std::nothrow_t &) noexcept;
///    void *operator new[](size_t);
///    void *operator new[](size_t, const std::nothrow_t &) noexcept;
///    void operator delete(void *) noexcept;
///    void operator delete(void *, std::size_t) noexcept;      [C++1y]
///    void operator delete(void *, const std::nothrow_t &) noexcept;
///    void operator delete[](void *) noexcept;
///    void operator delete[](void *, std::size_t) noexcept;    [C++1y]
///    void operator delete[](void *, const std::nothrow_t &) noexcept;
/// These functions have special behavior under C++1y [expr.new]:
///    An implementation is allowed to omit a call to a replaceable global
///    allocation function. [...]
///
/// If this function is an aligned allocation/deallocation function, return
/// the parameter number of the requested alignment through AlignmentParam.
///
/// If this function is an allocation/deallocation function that takes
/// the `std::nothrow_t` tag, return true through IsNothrow,
bool isReplaceableGlobalAllocationFunction(
    Optional<unsigned> *AlignmentParam = nullptr,
    bool *IsNothrow = nullptr) const;

/// Determine if this function provides an inline implementation of a builtin.
bool isInlineBuiltinDeclaration() const;

/// Determine whether this is a destroying operator delete.
bool isDestroyingOperatorDelete() const;

/// Compute the language linkage.
LanguageLinkage getLanguageLinkage() const;

/// Determines whether this function is a function with
/// external, C linkage.
bool isExternC() const;

/// Determines whether this function's context is, or is nested within,
/// a C++ extern "C" linkage spec.
bool isInExternCContext() const;

/// Determines whether this function's context is, or is nested within,
/// a C++ extern "C++" linkage spec.
bool isInExternCXXContext() const;

/// Determines whether this is a global function.
bool isGlobal() const;

/// Determines whether this function is known to be 'noreturn', through
/// an attribute on its declaration or its type.
bool isNoReturn() const;

/// True if the function was a definition but its body was skipped.
bool hasSkippedBody() const { return FunctionDeclBits.HasSkippedBody; }
void setHasSkippedBody(bool Skipped = true) {
  FunctionDeclBits.HasSkippedBody = Skipped;
}

/// True if this function will eventually have a body, once it's fully parsed.
bool willHaveBody() const { return FunctionDeclBits.WillHaveBody; }
void setWillHaveBody(bool V = true) { FunctionDeclBits.WillHaveBody = V; }

/// True if this function is considered a multiversioned function.
bool isMultiVersion() const {
  return getCanonicalDecl()->FunctionDeclBits.IsMultiVersion;
}

/// Sets the multiversion state for this declaration and all of its
/// redeclarations.
void setIsMultiVersion(bool V = true) {
  getCanonicalDecl()->FunctionDeclBits.IsMultiVersion = V;
}

/// Gets the kind of multiversioning attribute this declaration has. Note that
/// this can return a value even if the function is not multiversion, such as
/// the case of 'target'.
MultiVersionKind getMultiVersionKind() const;


/// True if this function is a multiversioned dispatch function as a part of
/// the cpu_specific/cpu_dispatch functionality.
bool isCPUDispatchMultiVersion() const;
/// True if this function is a multiversioned processor specific function as a
/// part of the cpu_specific/cpu_dispatch functionality.
bool isCPUSpecificMultiVersion() const;

/// True if this function is a multiversioned dispatch function as a part of
/// the target functionality.
bool isTargetMultiVersion() const;

/// \brief Get the associated-constraints of this function declaration.
/// Currently, this will either be a vector of size 1 containing the
/// trailing-requires-clause or an empty vector.
///
/// Use this instead of getTrailingRequiresClause for concepts APIs that
/// accept an ArrayRef of constraint expressions.
void getAssociatedConstraints(SmallVectorImpl<const Expr *> &AC) const {
  if (auto *TRC = getTrailingRequiresClause())
    AC.push_back(TRC);
}

void setPreviousDeclaration(FunctionDecl * PrevDecl);

FunctionDecl *getCanonicalDecl() override;
const FunctionDecl *getCanonicalDecl() const {
  return const_cast<FunctionDecl*>(this)->getCanonicalDecl();
}

unsigned getBuiltinID(bool ConsiderWrapperFunctions = false) const;

// ArrayRef interface to parameters.
ArrayRef<ParmVarDecl *> parameters() const {
  return {ParamInfo, getNumParams()};
}
MutableArrayRef<ParmVarDecl *> parameters() {
  return {ParamInfo, getNumParams()};
}

// Iterator access to formal parameters.
using param_iterator = MutableArrayRef<ParmVarDecl *>::iterator;
using param_const_iterator = ArrayRef<ParmVarDecl *>::const_iterator;

bool param_empty() const { return parameters().empty(); }
param_iterator param_begin() { return parameters().begin(); }
param_iterator param_end() { return parameters().end(); }
param_const_iterator param_begin() const { return parameters().begin(); }
param_const_iterator param_end() const { return parameters().end(); }
size_t param_size() const { return parameters().size(); }

/// Return the number of parameters this function must have based on its
/// FunctionType.  This is the length of the ParamInfo array after it has been
/// created.
unsigned getNumParams() const;

const ParmVarDecl *getParamDecl(unsigned i) const {
  assert(i < getNumParams() && "Illegal param #")((void)0);
  return ParamInfo[i];
}
ParmVarDecl *getParamDecl(unsigned i) {
  assert(i < getNumParams() && "Illegal param #")((void)0);
  return ParamInfo[i];
}
void setParams(ArrayRef<ParmVarDecl *> NewParamInfo) {
  setParams(getASTContext(), NewParamInfo);
}

/// Returns the minimum number of arguments needed to call this function. This
/// may be fewer than the number of function parameters, if some of the
/// parameters have default arguments (in C++).
unsigned getMinRequiredArguments() const;

/// Determine whether this function has a single parameter, or multiple
/// parameters where all but the first have default arguments.
///
/// This notion is used in the definition of copy/move constructors and
/// initializer list constructors. Note that, unlike getMinRequiredArguments,
/// parameter packs are not treated specially here.
bool hasOneParamOrDefaultArgs() const;

/// Find the source location information for how the type of this function
/// was written. May be absent (for example if the function was declared via
/// a typedef) and may contain a different type from that of the function
/// (for example if the function type was adjusted by an attribute).
FunctionTypeLoc getFunctionTypeLoc() const;

QualType getReturnType() const {
  return getType()->castAs<FunctionType>()->getReturnType();
}

/// Attempt to compute an informative source range covering the
/// function return type. This may omit qualifiers and other information with
/// limited representation in the AST.
SourceRange getReturnTypeSourceRange() const;

/// Attempt to compute an informative source range covering the
/// function parameters, including the ellipsis of a variadic function.
/// The source range excludes the parentheses, and is invalid if there are
/// no parameters and no ellipsis.
SourceRange getParametersSourceRange() const;

/// Get the declared return type, which may differ from the actual return
/// type if the return type is deduced.
QualType getDeclaredReturnType() const {
  auto *TSI = getTypeSourceInfo();
  QualType T = TSI ? TSI->getType() : getType();
  return T->castAs<FunctionType>()->getReturnType();
}

/// Gets the ExceptionSpecificationType as declared.
ExceptionSpecificationType getExceptionSpecType() const {
  auto *TSI = getTypeSourceInfo();
  QualType T = TSI ? TSI->getType() : getType();
  const auto *FPT = T->getAs<FunctionProtoType>();
  return FPT ? FPT->getExceptionSpecType() : EST_None;
}

/// Attempt to compute an informative source range covering the
/// function exception specification, if any.
SourceRange getExceptionSpecSourceRange() const;

/// Determine the type of an expression that calls this function.
QualType getCallResultType() const {
  return getType()->castAs<FunctionType>()->getCallResultType(
      getASTContext());
}

/// Returns the storage class as written in the source. For the
/// computed linkage of symbol, see getLinkage.
StorageClass getStorageClass() const {
  return static_cast<StorageClass>(FunctionDeclBits.SClass);
}

/// Sets the storage class as written in the source.
void setStorageClass(StorageClass SClass) {
  FunctionDeclBits.SClass = SClass;
}

/// Determine whether the "inline" keyword was specified for this
/// function.
bool isInlineSpecified() const { return FunctionDeclBits.IsInlineSpecified; }

/// Set whether the "inline" keyword was specified for this function.
void setInlineSpecified(bool I) {
  FunctionDeclBits.IsInlineSpecified = I;
  FunctionDeclBits.IsInline = I;
}

/// Flag that this function is implicitly inline.
void setImplicitlyInline(bool I = true) { FunctionDeclBits.IsInline = I; }

/// Determine whether this function should be inlined, because it is
/// either marked "inline" or "constexpr" or is a member function of a class
/// that was defined in the class body.
bool isInlined() const { return FunctionDeclBits.IsInline; }

bool isInlineDefinitionExternallyVisible() const;

bool isMSExternInline() const;

bool doesDeclarationForceExternallyVisibleDefinition() const;

bool isStatic() const { return getStorageClass() == SC_Static; }

/// Whether this function declaration represents an C++ overloaded
/// operator, e.g., "operator+".
bool isOverloadedOperator() const {
  return getOverloadedOperator() != OO_None;
}

OverloadedOperatorKind getOverloadedOperator() const;

const IdentifierInfo *getLiteralIdentifier() const;

/// If this function is an instantiation of a member function
/// of a class template specialization, retrieves the function from
/// which it was instantiated.
///
/// This routine will return non-NULL for (non-templated) member
/// functions of class templates and for instantiations of function
/// templates. For example, given:
///
/// \code
/// template<typename T>
/// struct X {
///   void f(T);
/// };
/// \endcode
///
/// The declaration for X<int>::f is a (non-templated) FunctionDecl
/// whose parent is the class template specialization X<int>. For
/// this declaration, getInstantiatedFromFunction() will return
/// the FunctionDecl X<T>::A. When a complete definition of
/// X<int>::A is required, it will be instantiated from the
/// declaration returned by getInstantiatedFromMemberFunction().
FunctionDecl *getInstantiatedFromMemberFunction() const;

/// What kind of templated function this is.
TemplatedKind getTemplatedKind() const;

/// If this function is an instantiation of a member function of a
/// class template specialization, retrieves the member specialization
/// information.
MemberSpecializationInfo *getMemberSpecializationInfo() const;

/// Specify that this record is an instantiation of the
/// member function FD.
void setInstantiationOfMemberFunction(FunctionDecl *FD,
                                      TemplateSpecializationKind TSK) {
  setInstantiationOfMemberFunction(getASTContext(), FD, TSK);
}

/// Retrieves the function template that is described by this
/// function declaration.
///
/// Every function template is represented as a FunctionTemplateDecl
/// and a FunctionDecl (or something derived from FunctionDecl). The
/// former contains template properties (such as the template
/// parameter lists) while the latter contains the actual
/// description of the template's
/// contents. FunctionTemplateDecl::getTemplatedDecl() retrieves the
/// FunctionDecl that describes the function template,
/// getDescribedFunctionTemplate() retrieves the
/// FunctionTemplateDecl from a FunctionDecl.
FunctionTemplateDecl *getDescribedFunctionTemplate() const;

void setDescribedFunctionTemplate(FunctionTemplateDecl *Template);

/// Determine whether this function is a function template
/// specialization.
bool isFunctionTemplateSpecialization() const {
  return getPrimaryTemplate() != nullptr;
}

/// If this function is actually a function template specialization,
/// retrieve information about this function template specialization.
/// Otherwise, returns NULL.
FunctionTemplateSpecializationInfo *getTemplateSpecializationInfo() const;

/// Determines whether this function is a function template
/// specialization or a member of a class template specialization that can
/// be implicitly instantiated.
bool isImplicitlyInstantiable() const;

/// Determines if the given function was instantiated from a
/// function template.
bool isTemplateInstantiation() const;

/// Retrieve the function declaration from which this function could
/// be instantiated, if it is an instantiation (rather than a non-template
/// or a specialization, for example).
///
/// If \p ForDefinition is \c false, explicit specializations will be treated
/// as if they were implicit instantiations. This will then find the pattern
/// corresponding to non-definition portions of the declaration, such as
/// default arguments and the exception specification.
FunctionDecl *
getTemplateInstantiationPattern(bool ForDefinition = true) const;

/// Retrieve the primary template that this function template
/// specialization either specializes or was instantiated from.
///
/// If this function declaration is not a function template specialization,
/// returns NULL.
FunctionTemplateDecl *getPrimaryTemplate() const;

/// Retrieve the template arguments used to produce this function
/// template specialization from the primary template.
///
/// If this function declaration is not a function template specialization,
/// returns NULL.
const TemplateArgumentList *getTemplateSpecializationArgs() const;

/// Retrieve the template argument list as written in the sources,
/// if any.
///
/// If this function declaration is not a function template specialization
/// or if it had no explicit template argument list, returns NULL.
/// Note that it an explicit template argument list may be written empty,
/// e.g., template<> void foo<>(char* s);
const ASTTemplateArgumentListInfo*
getTemplateSpecializationArgsAsWritten() const;

/// Specify that this function declaration is actually a function
/// template specialization.
///
/// \param Template the function template that this function template
/// specialization specializes.
///
/// \param TemplateArgs the template arguments that produced this
/// function template specialization from the template.
///
/// \param InsertPos If non-NULL, the position in the function template
/// specialization set where the function template specialization data will
/// be inserted.
///
/// \param TSK the kind of template specialization this is.
///
/// \param TemplateArgsAsWritten location info of template arguments.
///
/// \param PointOfInstantiation point at which the function template
/// specialization was first instantiated.
void setFunctionTemplateSpecialization(FunctionTemplateDecl *Template,
              const TemplateArgumentList *TemplateArgs,
              void *InsertPos,
              TemplateSpecializationKind TSK = TSK_ImplicitInstantiation,
              const TemplateArgumentListInfo *TemplateArgsAsWritten = nullptr,
              SourceLocation PointOfInstantiation = SourceLocation()) {
  setFunctionTemplateSpecialization(getASTContext(), Template, TemplateArgs,
                                    InsertPos, TSK, TemplateArgsAsWritten,
                                    PointOfInstantiation);
}

/// Specifies that this function declaration is actually a
/// dependent function template specialization.
void setDependentTemplateSpecialization(ASTContext &Context,
                           const UnresolvedSetImpl &Templates,
                    const TemplateArgumentListInfo &TemplateArgs);

DependentFunctionTemplateSpecializationInfo *
getDependentSpecializationInfo() const;

/// Determine what kind of template instantiation this function
/// represents.
TemplateSpecializationKind getTemplateSpecializationKind() const;

/// Determine the kind of template specialization this function represents
/// for the purpose of template instantiation.
TemplateSpecializationKind
getTemplateSpecializationKindForInstantiation() const;

/// Determine what kind of template instantiation this function
/// represents.
void setTemplateSpecializationKind(TemplateSpecializationKind TSK,
                      SourceLocation PointOfInstantiation = SourceLocation());

/// Retrieve the (first) point of instantiation of a function template
/// specialization or a member of a class template specialization.
///
/// \returns the first point of instantiation, if this function was
/// instantiated from a template; otherwise, returns an invalid source
/// location.
SourceLocation getPointOfInstantiation() const;

/// Determine whether this is or was instantiated from an out-of-line
/// definition of a member function.
bool isOutOfLine() const override;

/// Identify a memory copying or setting function.
/// If the given function is a memory copy or setting function, returns
/// the corresponding Builtin ID. If the function is not a memory function,
/// returns 0.
unsigned getMemoryFunctionKind() const;

/// Returns ODRHash of the function.  This value is calculated and
/// stored on first call, then the stored value returned on the other calls.
unsigned getODRHash();

/// Returns cached ODRHash of the function.  This must have been previously
/// computed and stored.
unsigned getODRHash() const;

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) {
  return K >= firstFunction && K <= lastFunction;
}
static DeclContext *castToDeclContext(const FunctionDecl *D) {
  return static_cast<DeclContext *>(const_cast<FunctionDecl*>(D));
}
static FunctionDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<FunctionDecl *>(const_cast<DeclContext*>(DC));
}
2822};

2824/// Represents a member of a struct/union/class.
2825class FieldDecl : public DeclaratorDecl, public Mergeable<FieldDecl> {
unsigned BitField : 1;
unsigned Mutable : 1;
mutable unsigned CachedFieldIndex : 30;

/// The kinds of value we can store in InitializerOrBitWidth.
///
/// Note that this is compatible with InClassInitStyle except for
/// ISK_CapturedVLAType.
enum InitStorageKind {
  /// If the pointer is null, there's nothing special.  Otherwise,
  /// this is a bitfield and the pointer is the Expr* storing the
  /// bit-width.
  ISK_NoInit = (unsigned) ICIS_NoInit,

  /// The pointer is an (optional due to delayed parsing) Expr*
  /// holding the copy-initializer.
  ISK_InClassCopyInit = (unsigned) ICIS_CopyInit,

  /// The pointer is an (optional due to delayed parsing) Expr*
  /// holding the list-initializer.
  ISK_InClassListInit = (unsigned) ICIS_ListInit,

  /// The pointer is a VariableArrayType* that's been captured;
  /// the enclosing context is a lambda or captured statement.
  ISK_CapturedVLAType,
};

/// If this is a bitfield with a default member initializer, this
/// structure is used to represent the two expressions.
struct InitAndBitWidth {
  Expr *Init;
  Expr *BitWidth;
};

/// Storage for either the bit-width, the in-class initializer, or
/// both (via InitAndBitWidth), or the captured variable length array bound.
///
/// If the storage kind is ISK_InClassCopyInit or
/// ISK_InClassListInit, but the initializer is null, then this
/// field has an in-class initializer that has not yet been parsed
/// and attached.
// FIXME: Tail-allocate this to reduce the size of FieldDecl in the
// overwhelmingly common case that we have none of these things.
llvm::PointerIntPair<void *, 2, InitStorageKind> InitStorage;

2871protected:
FieldDecl(Kind DK, DeclContext *DC, SourceLocation StartLoc,
          SourceLocation IdLoc, IdentifierInfo *Id,
          QualType T, TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
          InClassInitStyle InitStyle)
  : DeclaratorDecl(DK, DC, IdLoc, Id, T, TInfo, StartLoc),
    BitField(false), Mutable(Mutable), CachedFieldIndex(0),
    InitStorage(nullptr, (InitStorageKind) InitStyle) {
  if (BW)
    setBitWidth(BW);
}

2883public:
friend class ASTDeclReader;
friend class ASTDeclWriter;

static FieldDecl *Create(const ASTContext &C, DeclContext *DC,
                         SourceLocation StartLoc, SourceLocation IdLoc,
                         IdentifierInfo *Id, QualType T,
                         TypeSourceInfo *TInfo, Expr *BW, bool Mutable,
                         InClassInitStyle InitStyle);

static FieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);

/// Returns the index of this field within its record,
/// as appropriate for passing to ASTRecordLayout::getFieldOffset.
unsigned getFieldIndex() const;

/// Determines whether this field is mutable (C++ only).
bool isMutable() const { return Mutable; }

/// Determines whether this field is a bitfield.
bool isBitField() const { return BitField; }

/// Determines whether this is an unnamed bitfield.
bool isUnnamedBitfield() const { return isBitField() && !getDeclName(); }

/// Determines whether this field is a
/// representative for an anonymous struct or union. Such fields are
/// unnamed and are implicitly generated by the implementation to
/// store the data for the anonymous union or struct.
bool isAnonymousStructOrUnion() const;

Expr *getBitWidth() const {
  if (!BitField)
    return nullptr;
  void *Ptr = InitStorage.getPointer();
  if (getInClassInitStyle())
    return static_cast<InitAndBitWidth*>(Ptr)->BitWidth;
  return static_cast<Expr*>(Ptr);
}

unsigned getBitWidthValue(const ASTContext &Ctx) const;

/// Set the bit-field width for this member.
// Note: used by some clients (i.e., do not remove it).
void setBitWidth(Expr *Width) {
  assert(!hasCapturedVLAType() && !BitField &&((void)0)
         "bit width or captured type already set")((void)0);
  assert(Width && "no bit width specified")((void)0);
  InitStorage.setPointer(
      InitStorage.getInt()
          ? new (getASTContext())
                InitAndBitWidth{getInClassInitializer(), Width}
          : static_cast<void*>(Width));
  BitField = true;
}

/// Remove the bit-field width from this member.
// Note: used by some clients (i.e., do not remove it).
void removeBitWidth() {
  assert(isBitField() && "no bitfield width to remove")((void)0);
  InitStorage.setPointer(getInClassInitializer());
  BitField = false;
}

/// Is this a zero-length bit-field? Such bit-fields aren't really bit-fields
/// at all and instead act as a separator between contiguous runs of other
/// bit-fields.
bool isZeroLengthBitField(const ASTContext &Ctx) const;

/// Determine if this field is a subobject of zero size, that is, either a
/// zero-length bit-field or a field of empty class type with the
/// [[no_unique_address]] attribute.
bool isZeroSize(const ASTContext &Ctx) const;

/// Get the kind of (C++11) default member initializer that this field has.
InClassInitStyle getInClassInitStyle() const {
  InitStorageKind storageKind = InitStorage.getInt();
  return (storageKind == ISK_CapturedVLAType
            ? ICIS_NoInit : (InClassInitStyle) storageKind);
}

/// Determine whether this member has a C++11 default member initializer.
bool hasInClassInitializer() const {
  return getInClassInitStyle() != ICIS_NoInit;
29
←
Assuming the condition is false→
30
←
Returning zero, which participates in a condition later→
}

/// Get the C++11 default member initializer for this member, or null if one
/// has not been set. If a valid declaration has a default member initializer,
/// but this returns null, then we have not parsed and attached it yet.
Expr *getInClassInitializer() const {
  if (!hasInClassInitializer())
28
←
Calling 'FieldDecl::hasInClassInitializer'→
31
←
Returning from 'FieldDecl::hasInClassInitializer'→
32
←
Taking true branch→
    return nullptr;
33
←
Returning null pointer, which participates in a condition later→
  void *Ptr = InitStorage.getPointer();
  if (BitField)
    return static_cast<InitAndBitWidth*>(Ptr)->Init;
  return static_cast<Expr*>(Ptr);
}

/// Set the C++11 in-class initializer for this member.
void setInClassInitializer(Expr *Init) {
  assert(hasInClassInitializer() && !getInClassInitializer())((void)0);
  if (BitField)
    static_cast<InitAndBitWidth*>(InitStorage.getPointer())->Init = Init;
  else
    InitStorage.setPointer(Init);
}

/// Remove the C++11 in-class initializer from this member.
void removeInClassInitializer() {
  assert(hasInClassInitializer() && "no initializer to remove")((void)0);
  InitStorage.setPointerAndInt(getBitWidth(), ISK_NoInit);
}

/// Determine whether this member captures the variable length array
/// type.
bool hasCapturedVLAType() const {
  return InitStorage.getInt() == ISK_CapturedVLAType;
}

/// Get the captured variable length array type.
const VariableArrayType *getCapturedVLAType() const {
  return hasCapturedVLAType() ? static_cast<const VariableArrayType *>(
                                    InitStorage.getPointer())
                              : nullptr;
}

/// Set the captured variable length array type for this field.
void setCapturedVLAType(const VariableArrayType *VLAType);

/// Returns the parent of this field declaration, which
/// is the struct in which this field is defined.
///
/// Returns null if this is not a normal class/struct field declaration, e.g.
/// ObjCAtDefsFieldDecl, ObjCIvarDecl.
const RecordDecl *getParent() const {
  return dyn_cast<RecordDecl>(getDeclContext());
}

RecordDecl *getParent() {
  return dyn_cast<RecordDecl>(getDeclContext());
}

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

/// Retrieves the canonical declaration of this field.
FieldDecl *getCanonicalDecl() override { return getFirstDecl(); }
const FieldDecl *getCanonicalDecl() const { return getFirstDecl(); }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstField && K <= lastField; }
3034};

3036/// An instance of this object exists for each enum constant
3037/// that is defined.  For example, in "enum X {a,b}", each of a/b are
3038/// EnumConstantDecl's, X is an instance of EnumDecl, and the type of a/b is a
3039/// TagType for the X EnumDecl.
3040class EnumConstantDecl : public ValueDecl, public Mergeable<EnumConstantDecl> {
Stmt *Init; // an integer constant expression
llvm::APSInt Val; // The value.

3044protected:
EnumConstantDecl(DeclContext *DC, SourceLocation L,
                 IdentifierInfo *Id, QualType T, Expr *E,
                 const llvm::APSInt &V)
  : ValueDecl(EnumConstant, DC, L, Id, T), Init((Stmt*)E), Val(V) {}

3050public:
friend class StmtIteratorBase;

static EnumConstantDecl *Create(ASTContext &C, EnumDecl *DC,
                                SourceLocation L, IdentifierInfo *Id,
                                QualType T, Expr *E,
                                const llvm::APSInt &V);
static EnumConstantDecl *CreateDeserialized(ASTContext &C, unsigned ID);

const Expr *getInitExpr() const { return (const Expr*) Init; }
Expr *getInitExpr() { return (Expr*) Init; }
const llvm::APSInt &getInitVal() const { return Val; }

void setInitExpr(Expr *E) { Init = (Stmt*) E; }
void setInitVal(const llvm::APSInt &V) { Val = V; }

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

/// Retrieves the canonical declaration of this enumerator.
EnumConstantDecl *getCanonicalDecl() override { return getFirstDecl(); }
const EnumConstantDecl *getCanonicalDecl() const { return getFirstDecl(); }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == EnumConstant; }
3075};

3077/// Represents a field injected from an anonymous union/struct into the parent
3078/// scope. These are always implicit.
3079class IndirectFieldDecl : public ValueDecl,
                        public Mergeable<IndirectFieldDecl> {
NamedDecl **Chaining;
unsigned ChainingSize;

IndirectFieldDecl(ASTContext &C, DeclContext *DC, SourceLocation L,
                  DeclarationName N, QualType T,
                  MutableArrayRef<NamedDecl *> CH);

void anchor() override;

3090public:
friend class ASTDeclReader;

static IndirectFieldDecl *Create(ASTContext &C, DeclContext *DC,
                                 SourceLocation L, IdentifierInfo *Id,
                                 QualType T, llvm::MutableArrayRef<NamedDecl *> CH);

static IndirectFieldDecl *CreateDeserialized(ASTContext &C, unsigned ID);

using chain_iterator = ArrayRef<NamedDecl *>::const_iterator;

ArrayRef<NamedDecl *> chain() const {
  return llvm::makeArrayRef(Chaining, ChainingSize);
}
chain_iterator chain_begin() const { return chain().begin(); }
chain_iterator chain_end() const { return chain().end(); }

unsigned getChainingSize() const { return ChainingSize; }

FieldDecl *getAnonField() const {
  assert(chain().size() >= 2)((void)0);
  return cast<FieldDecl>(chain().back());
}

VarDecl *getVarDecl() const {
  assert(chain().size() >= 2)((void)0);
  return dyn_cast<VarDecl>(chain().front());
}

IndirectFieldDecl *getCanonicalDecl() override { return getFirstDecl(); }
const IndirectFieldDecl *getCanonicalDecl() const { return getFirstDecl(); }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == IndirectField; }
3125};

3127/// Represents a declaration of a type.
3128class TypeDecl : public NamedDecl {
friend class ASTContext;

/// This indicates the Type object that represents
/// this TypeDecl.  It is a cache maintained by
/// ASTContext::getTypedefType, ASTContext::getTagDeclType, and
/// ASTContext::getTemplateTypeParmType, and TemplateTypeParmDecl.
mutable const Type *TypeForDecl = nullptr;

/// The start of the source range for this declaration.
SourceLocation LocStart;

void anchor() override;

3142protected:
TypeDecl(Kind DK, DeclContext *DC, SourceLocation L, IdentifierInfo *Id,
         SourceLocation StartL = SourceLocation())
  : NamedDecl(DK, DC, L, Id), LocStart(StartL) {}

3147public:
// Low-level accessor. If you just want the type defined by this node,
// check out ASTContext::getTypeDeclType or one of
// ASTContext::getTypedefType, ASTContext::getRecordType, etc. if you
// already know the specific kind of node this is.
const Type *getTypeForDecl() const { return TypeForDecl; }
void setTypeForDecl(const Type *TD) { TypeForDecl = TD; }

SourceLocation getBeginLoc() const LLVM_READONLY__attribute__((__pure__)) { return LocStart; }
void setLocStart(SourceLocation L) { LocStart = L; }
SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__)) {
  if (LocStart.isValid())
    return SourceRange(LocStart, getLocation());
  else
    return SourceRange(getLocation());
}

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstType && K <= lastType; }
3167};

3169/// Base class for declarations which introduce a typedef-name.
3170class TypedefNameDecl : public TypeDecl, public Redeclarable<TypedefNameDecl> {
struct alignas(8) ModedTInfo {
  TypeSourceInfo *first;
  QualType second;
};

/// If int part is 0, we have not computed IsTransparentTag.
/// Otherwise, IsTransparentTag is (getInt() >> 1).
mutable llvm::PointerIntPair<
    llvm::PointerUnion<TypeSourceInfo *, ModedTInfo *>, 2>
    MaybeModedTInfo;

void anchor() override;

3184protected:
TypedefNameDecl(Kind DK, ASTContext &C, DeclContext *DC,
                SourceLocation StartLoc, SourceLocation IdLoc,
                IdentifierInfo *Id, TypeSourceInfo *TInfo)
    : TypeDecl(DK, DC, IdLoc, Id, StartLoc), redeclarable_base(C),
      MaybeModedTInfo(TInfo, 0) {}

using redeclarable_base = Redeclarable<TypedefNameDecl>;

TypedefNameDecl *getNextRedeclarationImpl() override {
  return getNextRedeclaration();
}

TypedefNameDecl *getPreviousDeclImpl() override {
  return getPreviousDecl();
}

TypedefNameDecl *getMostRecentDeclImpl() override {
  return getMostRecentDecl();
}

3205public:
using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;
using redeclarable_base::redecls;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::getMostRecentDecl;
using redeclarable_base::isFirstDecl;

bool isModed() const {
  return MaybeModedTInfo.getPointer().is<ModedTInfo *>();
}

TypeSourceInfo *getTypeSourceInfo() const {
  return isModed() ? MaybeModedTInfo.getPointer().get<ModedTInfo *>()->first
                   : MaybeModedTInfo.getPointer().get<TypeSourceInfo *>();
}

QualType getUnderlyingType() const {
  return isModed() ? MaybeModedTInfo.getPointer().get<ModedTInfo *>()->second
                   : MaybeModedTInfo.getPointer()
                         .get<TypeSourceInfo *>()
                         ->getType();
}

void setTypeSourceInfo(TypeSourceInfo *newType) {
  MaybeModedTInfo.setPointer(newType);
}

void setModedTypeSourceInfo(TypeSourceInfo *unmodedTSI, QualType modedTy) {
  MaybeModedTInfo.setPointer(new (getASTContext(), 8)
                                 ModedTInfo({unmodedTSI, modedTy}));
}

/// Retrieves the canonical declaration of this typedef-name.
TypedefNameDecl *getCanonicalDecl() override { return getFirstDecl(); }
const TypedefNameDecl *getCanonicalDecl() const { return getFirstDecl(); }

/// Retrieves the tag declaration for which this is the typedef name for
/// linkage purposes, if any.
///
/// \param AnyRedecl Look for the tag declaration in any redeclaration of
/// this typedef declaration.
TagDecl *getAnonDeclWithTypedefName(bool AnyRedecl = false) const;

/// Determines if this typedef shares a name and spelling location with its
/// underlying tag type, as is the case with the NS_ENUM macro.
bool isTransparentTag() const {
  if (MaybeModedTInfo.getInt())
    return MaybeModedTInfo.getInt() & 0x2;
  return isTransparentTagSlow();
}

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) {
  return K >= firstTypedefName && K <= lastTypedefName;
}

3266private:
bool isTransparentTagSlow() const;
3268};

3270/// Represents the declaration of a typedef-name via the 'typedef'
3271/// type specifier.
3272class TypedefDecl : public TypedefNameDecl {
TypedefDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
            SourceLocation IdLoc, IdentifierInfo *Id, TypeSourceInfo *TInfo)
    : TypedefNameDecl(Typedef, C, DC, StartLoc, IdLoc, Id, TInfo) {}

3277public:
static TypedefDecl *Create(ASTContext &C, DeclContext *DC,
                           SourceLocation StartLoc, SourceLocation IdLoc,
                           IdentifierInfo *Id, TypeSourceInfo *TInfo);
static TypedefDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Typedef; }
3288};

3290/// Represents the declaration of a typedef-name via a C++11
3291/// alias-declaration.
3292class TypeAliasDecl : public TypedefNameDecl {
/// The template for which this is the pattern, if any.
TypeAliasTemplateDecl *Template;

TypeAliasDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
              SourceLocation IdLoc, IdentifierInfo *Id, TypeSourceInfo *TInfo)
    : TypedefNameDecl(TypeAlias, C, DC, StartLoc, IdLoc, Id, TInfo),
      Template(nullptr) {}

3301public:
static TypeAliasDecl *Create(ASTContext &C, DeclContext *DC,
                             SourceLocation StartLoc, SourceLocation IdLoc,
                             IdentifierInfo *Id, TypeSourceInfo *TInfo);
static TypeAliasDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

TypeAliasTemplateDecl *getDescribedAliasTemplate() const { return Template; }
void setDescribedAliasTemplate(TypeAliasTemplateDecl *TAT) { Template = TAT; }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == TypeAlias; }
3315};

3317/// Represents the declaration of a struct/union/class/enum.
3318class TagDecl : public TypeDecl,
              public DeclContext,
              public Redeclarable<TagDecl> {
// This class stores some data in DeclContext::TagDeclBits
// to save some space. Use the provided accessors to access it.
3323public:
// This is really ugly.
using TagKind = TagTypeKind;

3327private:
SourceRange BraceRange;

// A struct representing syntactic qualifier info,
// to be used for the (uncommon) case of out-of-line declarations.
using ExtInfo = QualifierInfo;

/// If the (out-of-line) tag declaration name
/// is qualified, it points to the qualifier info (nns and range);
/// otherwise, if the tag declaration is anonymous and it is part of
/// a typedef or alias, it points to the TypedefNameDecl (used for mangling);
/// otherwise, if the tag declaration is anonymous and it is used as a
/// declaration specifier for variables, it points to the first VarDecl (used
/// for mangling);
/// otherwise, it is a null (TypedefNameDecl) pointer.
llvm::PointerUnion<TypedefNameDecl *, ExtInfo *> TypedefNameDeclOrQualifier;

bool hasExtInfo() const { return TypedefNameDeclOrQualifier.is<ExtInfo *>(); }
ExtInfo *getExtInfo() { return TypedefNameDeclOrQualifier.get<ExtInfo *>(); }
const ExtInfo *getExtInfo() const {
  return TypedefNameDeclOrQualifier.get<ExtInfo *>();
}

3350protected:
TagDecl(Kind DK, TagKind TK, const ASTContext &C, DeclContext *DC,
        SourceLocation L, IdentifierInfo *Id, TagDecl *PrevDecl,
        SourceLocation StartL);

using redeclarable_base = Redeclarable<TagDecl>;

TagDecl *getNextRedeclarationImpl() override {
  return getNextRedeclaration();
}

TagDecl *getPreviousDeclImpl() override {
  return getPreviousDecl();
}

TagDecl *getMostRecentDeclImpl() override {
  return getMostRecentDecl();
}

/// Completes the definition of this tag declaration.
///
/// This is a helper function for derived classes.
void completeDefinition();

/// True if this decl is currently being defined.
void setBeingDefined(bool V = true) { TagDeclBits.IsBeingDefined = V; }

/// 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.
void setMayHaveOutOfDateDef(bool V = true) {
  TagDeclBits.MayHaveOutOfDateDef = V;
}

3385public:
friend class ASTDeclReader;
friend class ASTDeclWriter;

using redecl_range = redeclarable_base::redecl_range;
using redecl_iterator = redeclarable_base::redecl_iterator;

using redeclarable_base::redecls_begin;
using redeclarable_base::redecls_end;
using redeclarable_base::redecls;
using redeclarable_base::getPreviousDecl;
using redeclarable_base::getMostRecentDecl;
using redeclarable_base::isFirstDecl;

SourceRange getBraceRange() const { return BraceRange; }
void setBraceRange(SourceRange R) { BraceRange = R; }

/// Return SourceLocation representing start of source
/// range ignoring outer template declarations.
SourceLocation getInnerLocStart() const { return getBeginLoc(); }

/// Return SourceLocation representing start of source
/// range taking into account any outer template declarations.
SourceLocation getOuterLocStart() const;
SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

TagDecl *getCanonicalDecl() override;
const TagDecl *getCanonicalDecl() const {
  return const_cast<TagDecl*>(this)->getCanonicalDecl();
}

/// Return true if this declaration is a completion definition of the type.
/// Provided for consistency.
bool isThisDeclarationADefinition() const {
  return isCompleteDefinition();
}

/// Return true if this decl has its body fully specified.
bool isCompleteDefinition() const { return TagDeclBits.IsCompleteDefinition; }

/// True if this decl has its body fully specified.
void setCompleteDefinition(bool V = true) {
  TagDeclBits.IsCompleteDefinition = V;
}

/// Return true if this complete decl is
/// required to be complete for some existing use.
bool isCompleteDefinitionRequired() const {
  return TagDeclBits.IsCompleteDefinitionRequired;
}

/// True if this complete decl is
/// required to be complete for some existing use.
void setCompleteDefinitionRequired(bool V = true) {
  TagDeclBits.IsCompleteDefinitionRequired = V;
}

/// Return true if this decl is currently being defined.
bool isBeingDefined() const { return TagDeclBits.IsBeingDefined; }

/// True if this tag declaration is "embedded" (i.e., defined or declared
/// for the very first time) in the syntax of a declarator.
bool isEmbeddedInDeclarator() const {
  return TagDeclBits.IsEmbeddedInDeclarator;
}

/// True if this tag declaration is "embedded" (i.e., defined or declared
/// for the very first time) in the syntax of a declarator.
void setEmbeddedInDeclarator(bool isInDeclarator) {
  TagDeclBits.IsEmbeddedInDeclarator = isInDeclarator;
}

/// True if this tag is free standing, e.g. "struct foo;".
bool isFreeStanding() const { return TagDeclBits.IsFreeStanding; }

/// True if this tag is free standing, e.g. "struct foo;".
void setFreeStanding(bool isFreeStanding = true) {
  TagDeclBits.IsFreeStanding = isFreeStanding;
}

/// 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.
bool mayHaveOutOfDateDef() const { return TagDeclBits.MayHaveOutOfDateDef; }

/// Whether this declaration declares a type that is
/// dependent, i.e., a type that somehow depends on template
/// parameters.
bool isDependentType() const { return isDependentContext(); }

/// Starts the definition of this tag declaration.
///
/// This method should be invoked at the beginning of the definition
/// of this tag declaration. It will set the tag type into a state
/// where it is in the process of being defined.
void startDefinition();

/// Returns the TagDecl that actually defines this
///  struct/union/class/enum.  When determining whether or not a
///  struct/union/class/enum has a definition, one should use this
///  method as opposed to 'isDefinition'.  'isDefinition' indicates
///  whether or not a specific TagDecl is defining declaration, not
///  whether or not the struct/union/class/enum type is defined.
///  This method returns NULL if there is no TagDecl that defines
///  the struct/union/class/enum.
TagDecl *getDefinition() const;

StringRef getKindName() const {
  return TypeWithKeyword::getTagTypeKindName(getTagKind());
}

TagKind getTagKind() const {
  return static_cast<TagKind>(TagDeclBits.TagDeclKind);
}

void setTagKind(TagKind TK) { TagDeclBits.TagDeclKind = TK; }

bool isStruct() const { return getTagKind() == TTK_Struct; }
bool isInterface() const { return getTagKind() == TTK_Interface; }
bool isClass()  const { return getTagKind() == TTK_Class; }
bool isUnion()  const { return getTagKind() == TTK_Union; }
bool isEnum()   const { return getTagKind() == TTK_Enum; }

/// Is this tag type named, either directly or via being defined in
/// a typedef of this type?
///
/// C++11 [basic.link]p8:
///   A type is said to have linkage if and only if:
///     - it is a class or enumeration type that is named (or has a
///       name for linkage purposes) and the name has linkage; ...
/// C++11 [dcl.typedef]p9:
///   If the typedef declaration defines an unnamed class (or enum),
///   the first typedef-name declared by the declaration to be that
///   class type (or enum type) is used to denote the class type (or
///   enum type) for linkage purposes only.
///
/// C does not have an analogous rule, but the same concept is
/// nonetheless useful in some places.
bool hasNameForLinkage() const {
  return (getDeclName() || getTypedefNameForAnonDecl());
}

TypedefNameDecl *getTypedefNameForAnonDecl() const {
  return hasExtInfo() ? nullptr
                      : TypedefNameDeclOrQualifier.get<TypedefNameDecl *>();
}

void setTypedefNameForAnonDecl(TypedefNameDecl *TDD);

/// Retrieve the nested-name-specifier that qualifies the name of this
/// declaration, if it was present in the source.
NestedNameSpecifier *getQualifier() const {
  return hasExtInfo() ? getExtInfo()->QualifierLoc.getNestedNameSpecifier()
                      : nullptr;
}

/// Retrieve the nested-name-specifier (with source-location
/// information) that qualifies the name of this declaration, if it was
/// present in the source.
NestedNameSpecifierLoc getQualifierLoc() const {
  return hasExtInfo() ? getExtInfo()->QualifierLoc
                      : NestedNameSpecifierLoc();
}

void setQualifierInfo(NestedNameSpecifierLoc QualifierLoc);

unsigned getNumTemplateParameterLists() const {
  return hasExtInfo() ? getExtInfo()->NumTemplParamLists : 0;
}

TemplateParameterList *getTemplateParameterList(unsigned i) const {
  assert(i < getNumTemplateParameterLists())((void)0);
  return getExtInfo()->TemplParamLists[i];
}

void setTemplateParameterListsInfo(ASTContext &Context,
                                   ArrayRef<TemplateParameterList *> TPLists);

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K >= firstTag && K <= lastTag; }

static DeclContext *castToDeclContext(const TagDecl *D) {
  return static_cast<DeclContext *>(const_cast<TagDecl*>(D));
}

static TagDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<TagDecl *>(const_cast<DeclContext*>(DC));
}
3575};

3577/// Represents an enum.  In C++11, enums can be forward-declared
3578/// with a fixed underlying type, and in C we allow them to be forward-declared
3579/// with no underlying type as an extension.
3580class EnumDecl : public TagDecl {
// This class stores some data in DeclContext::EnumDeclBits
// to save some space. Use the provided accessors to access it.

/// This represent the integer type that the enum corresponds
/// to for code generation purposes.  Note that the enumerator constants may
/// have a different type than this does.
///
/// If the underlying integer type was explicitly stated in the source
/// code, this is a TypeSourceInfo* for that type. Otherwise this type
/// was automatically deduced somehow, and this is a Type*.
///
/// Normally if IsFixed(), this would contain a TypeSourceInfo*, but in
/// some cases it won't.
///
/// The underlying type of an enumeration never has any qualifiers, so
/// we can get away with just storing a raw Type*, and thus save an
/// extra pointer when TypeSourceInfo is needed.
llvm::PointerUnion<const Type *, TypeSourceInfo *> IntegerType;

/// The integer type that values of this type should
/// promote to.  In C, enumerators are generally of an integer type
/// directly, but gcc-style large enumerators (and all enumerators
/// in C++) are of the enum type instead.
QualType PromotionType;

/// If this enumeration is an instantiation of a member enumeration
/// of a class template specialization, this is the member specialization
/// information.
MemberSpecializationInfo *SpecializationInfo = nullptr;

/// Store the ODRHash after first calculation.
/// The corresponding flag HasODRHash is in EnumDeclBits
/// and can be accessed with the provided accessors.
unsigned ODRHash;

EnumDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
         SourceLocation IdLoc, IdentifierInfo *Id, EnumDecl *PrevDecl,
         bool Scoped, bool ScopedUsingClassTag, bool Fixed);

void anchor() override;

void setInstantiationOfMemberEnum(ASTContext &C, EnumDecl *ED,
                                  TemplateSpecializationKind TSK);

/// Sets the width in bits required to store all the
/// non-negative enumerators of this enum.
void setNumPositiveBits(unsigned Num) {
  EnumDeclBits.NumPositiveBits = Num;
  assert(EnumDeclBits.NumPositiveBits == Num && "can't store this bitcount")((void)0);
}

/// Returns the width in bits required to store all the
/// negative enumerators of this enum. (see getNumNegativeBits)
void setNumNegativeBits(unsigned Num) { EnumDeclBits.NumNegativeBits = Num; }

3636public:
/// True if this tag declaration is a scoped enumeration. Only
/// possible in C++11 mode.
void setScoped(bool Scoped = true) { EnumDeclBits.IsScoped = Scoped; }

/// 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.
void setScopedUsingClassTag(bool ScopedUCT = true) {
  EnumDeclBits.IsScopedUsingClassTag = ScopedUCT;
}

/// True if this is an Objective-C, C++11, or
/// Microsoft-style enumeration with a fixed underlying type.
void setFixed(bool Fixed = true) { EnumDeclBits.IsFixed = Fixed; }

3653private:
/// True if a valid hash is stored in ODRHash.
bool hasODRHash() const { return EnumDeclBits.HasODRHash; }
void setHasODRHash(bool Hash = true) { EnumDeclBits.HasODRHash = Hash; }

3658public:
friend class ASTDeclReader;

EnumDecl *getCanonicalDecl() override {
  return cast<EnumDecl>(TagDecl::getCanonicalDecl());
}
const EnumDecl *getCanonicalDecl() const {
  return const_cast<EnumDecl*>(this)->getCanonicalDecl();
}

EnumDecl *getPreviousDecl() {
  return cast_or_null<EnumDecl>(
          static_cast<TagDecl *>(this)->getPreviousDecl());
}
const EnumDecl *getPreviousDecl() const {
  return const_cast<EnumDecl*>(this)->getPreviousDecl();
}

EnumDecl *getMostRecentDecl() {
  return cast<EnumDecl>(static_cast<TagDecl *>(this)->getMostRecentDecl());
}
const EnumDecl *getMostRecentDecl() const {
  return const_cast<EnumDecl*>(this)->getMostRecentDecl();
}

EnumDecl *getDefinition() const {
  return cast_or_null<EnumDecl>(TagDecl::getDefinition());
}

static EnumDecl *Create(ASTContext &C, DeclContext *DC,
                        SourceLocation StartLoc, SourceLocation IdLoc,
                        IdentifierInfo *Id, EnumDecl *PrevDecl,
                        bool IsScoped, bool IsScopedUsingClassTag,
                        bool IsFixed);
static EnumDecl *CreateDeserialized(ASTContext &C, unsigned ID);

/// When created, the EnumDecl corresponds to a
/// forward-declared enum. This method is used to mark the
/// declaration as being defined; its enumerators have already been
/// added (via DeclContext::addDecl). NewType is the new underlying
/// type of the enumeration type.
void completeDefinition(QualType NewType,
                        QualType PromotionType,
                        unsigned NumPositiveBits,
                        unsigned NumNegativeBits);

// Iterates through the enumerators of this enumeration.
using enumerator_iterator = specific_decl_iterator<EnumConstantDecl>;
using enumerator_range =
    llvm::iterator_range<specific_decl_iterator<EnumConstantDecl>>;

enumerator_range enumerators() const {
  return enumerator_range(enumerator_begin(), enumerator_end());
}

enumerator_iterator enumerator_begin() const {
  const EnumDecl *E = getDefinition();
  if (!E)
    E = this;
  return enumerator_iterator(E->decls_begin());
}

enumerator_iterator enumerator_end() const {
  const EnumDecl *E = getDefinition();
  if (!E)
    E = this;
  return enumerator_iterator(E->decls_end());
}

/// Return the integer type that enumerators should promote to.
QualType getPromotionType() const { return PromotionType; }

/// Set the promotion type.
void setPromotionType(QualType T) { PromotionType = T; }

/// Return the integer type this enum decl corresponds to.
/// This returns a null QualType for an enum forward definition with no fixed
/// underlying type.
QualType getIntegerType() const {
  if (!IntegerType)
    return QualType();
  if (const Type *T = IntegerType.dyn_cast<const Type*>())
    return QualType(T, 0);
  return IntegerType.get<TypeSourceInfo*>()->getType().getUnqualifiedType();
}

/// Set the underlying integer type.
void setIntegerType(QualType T) { IntegerType = T.getTypePtrOrNull(); }

/// Set the underlying integer type source info.
void setIntegerTypeSourceInfo(TypeSourceInfo *TInfo) { IntegerType = TInfo; }

/// Return the type source info for the underlying integer type,
/// if no type source info exists, return 0.
TypeSourceInfo *getIntegerTypeSourceInfo() const {
  return IntegerType.dyn_cast<TypeSourceInfo*>();
}

/// Retrieve the source range that covers the underlying type if
/// specified.
SourceRange getIntegerTypeRange() const LLVM_READONLY__attribute__((__pure__));

/// Returns the width in bits required to store all the
/// non-negative enumerators of this enum.
unsigned getNumPositiveBits() const { return EnumDeclBits.NumPositiveBits; }

/// Returns the width in bits required to store all the
/// negative enumerators of this enum.  These widths include
/// the rightmost leading 1;  that is:
///
/// MOST NEGATIVE ENUMERATOR     PATTERN     NUM NEGATIVE BITS
/// ------------------------     -------     -----------------
///                       -1     1111111                     1
///                      -10     1110110                     5
///                     -101     1001011                     8
unsigned getNumNegativeBits() const { return EnumDeclBits.NumNegativeBits; }

/// Returns true if this is a C++11 scoped enumeration.
bool isScoped() const { return EnumDeclBits.IsScoped; }

/// Returns true if this is a C++11 scoped enumeration.
bool isScopedUsingClassTag() const {
  return EnumDeclBits.IsScopedUsingClassTag;
}

/// Returns true if this is an Objective-C, C++11, or
/// Microsoft-style enumeration with a fixed underlying type.
bool isFixed() const { return EnumDeclBits.IsFixed; }

unsigned getODRHash();

/// Returns true if this can be considered a complete type.
bool isComplete() const {
  // IntegerType is set for fixed type enums and non-fixed but implicitly
  // int-sized Microsoft enums.
  return isCompleteDefinition() || IntegerType;
}

/// Returns true if this enum is either annotated with
/// enum_extensibility(closed) or isn't annotated with enum_extensibility.
bool isClosed() const;

/// Returns true if this enum is annotated with flag_enum and isn't annotated
/// with enum_extensibility(open).
bool isClosedFlag() const;

/// Returns true if this enum is annotated with neither flag_enum nor
/// enum_extensibility(open).
bool isClosedNonFlag() const;

/// Retrieve the enum definition from which this enumeration could
/// be instantiated, if it is an instantiation (rather than a non-template).
EnumDecl *getTemplateInstantiationPattern() const;

/// Returns the enumeration (declared within the template)
/// from which this enumeration type was instantiated, or NULL if
/// this enumeration was not instantiated from any template.
EnumDecl *getInstantiatedFromMemberEnum() const;

/// If this enumeration is a member of a specialization of a
/// templated class, determine what kind of template specialization
/// or instantiation this is.
TemplateSpecializationKind getTemplateSpecializationKind() const;

/// For an enumeration member that was instantiated from a member
/// enumeration of a templated class, set the template specialiation kind.
void setTemplateSpecializationKind(TemplateSpecializationKind TSK,
                      SourceLocation PointOfInstantiation = SourceLocation());

/// If this enumeration is an instantiation of a member enumeration of
/// a class template specialization, retrieves the member specialization
/// information.
MemberSpecializationInfo *getMemberSpecializationInfo() const {
  return SpecializationInfo;
}

/// Specify that this enumeration is an instantiation of the
/// member enumeration ED.
void setInstantiationOfMemberEnum(EnumDecl *ED,
                                  TemplateSpecializationKind TSK) {
  setInstantiationOfMemberEnum(getASTContext(), ED, TSK);
}

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Enum; }
3843};

3845/// Represents a struct/union/class.  For example:
3846///   struct X;                  // Forward declaration, no "body".
3847///   union Y { int A, B; };     // Has body with members A and B (FieldDecls).
3848/// This decl will be marked invalid if *any* members are invalid.
3849class RecordDecl : public TagDecl {
// This class stores some data in DeclContext::RecordDeclBits
// to save some space. Use the provided accessors to access it.
3852public:
friend class DeclContext;
/// Enum that represents the different ways arguments are passed to and
/// returned from function calls. This takes into account the target-specific
/// and version-specific rules along with the rules determined by the
/// language.
enum ArgPassingKind : unsigned {
  /// The argument of this type can be passed directly in registers.
  APK_CanPassInRegs,

  /// The argument of this type cannot be passed directly in registers.
  /// Records containing this type as a subobject are not forced to be passed
  /// indirectly. This value is used only in C++. This value is required by
  /// C++ because, in uncommon situations, it is possible for a class to have
  /// only trivial copy/move constructors even when one of its subobjects has
  /// a non-trivial copy/move constructor (if e.g. the corresponding copy/move
  /// constructor in the derived class is deleted).
  APK_CannotPassInRegs,

  /// The argument of this type cannot be passed directly in registers.
  /// Records containing this type as a subobject are forced to be passed
  /// indirectly.
  APK_CanNeverPassInRegs
};

3877protected:
RecordDecl(Kind DK, TagKind TK, const ASTContext &C, DeclContext *DC,
           SourceLocation StartLoc, SourceLocation IdLoc,
           IdentifierInfo *Id, RecordDecl *PrevDecl);

3882public:
static RecordDecl *Create(const ASTContext &C, TagKind TK, DeclContext *DC,
                          SourceLocation StartLoc, SourceLocation IdLoc,
                          IdentifierInfo *Id, RecordDecl* PrevDecl = nullptr);
static RecordDecl *CreateDeserialized(const ASTContext &C, unsigned ID);

RecordDecl *getPreviousDecl() {
  return cast_or_null<RecordDecl>(
          static_cast<TagDecl *>(this)->getPreviousDecl());
}
const RecordDecl *getPreviousDecl() const {
  return const_cast<RecordDecl*>(this)->getPreviousDecl();
}

RecordDecl *getMostRecentDecl() {
  return cast<RecordDecl>(static_cast<TagDecl *>(this)->getMostRecentDecl());
}
const RecordDecl *getMostRecentDecl() const {
  return const_cast<RecordDecl*>(this)->getMostRecentDecl();
}

bool hasFlexibleArrayMember() const {
  return RecordDeclBits.HasFlexibleArrayMember;
}

void setHasFlexibleArrayMember(bool V) {
  RecordDeclBits.HasFlexibleArrayMember = V;
}

/// Whether this is an anonymous struct or union. To be an anonymous
/// struct or union, it must have been declared without a name and
/// there must be no objects of this type declared, e.g.,
/// @code
///   union { int i; float f; };
/// @endcode
/// is an anonymous union but neither of the following are:
/// @code
///  union X { int i; float f; };
///  union { int i; float f; } obj;
/// @endcode
bool isAnonymousStructOrUnion() const {
  return RecordDeclBits.AnonymousStructOrUnion;
}

void setAnonymousStructOrUnion(bool Anon) {
  RecordDeclBits.AnonymousStructOrUnion = Anon;
}

bool hasObjectMember() const { return RecordDeclBits.HasObjectMember; }
void setHasObjectMember(bool val) { RecordDeclBits.HasObjectMember = val; }

bool hasVolatileMember() const { return RecordDeclBits.HasVolatileMember; }

void setHasVolatileMember(bool val) {
  RecordDeclBits.HasVolatileMember = val;
}

bool hasLoadedFieldsFromExternalStorage() const {
  return RecordDeclBits.LoadedFieldsFromExternalStorage;
}

void setHasLoadedFieldsFromExternalStorage(bool val) const {
  RecordDeclBits.LoadedFieldsFromExternalStorage = val;
}

/// Functions to query basic properties of non-trivial C structs.
bool isNonTrivialToPrimitiveDefaultInitialize() const {
  return RecordDeclBits.NonTrivialToPrimitiveDefaultInitialize;
}

void setNonTrivialToPrimitiveDefaultInitialize(bool V) {
  RecordDeclBits.NonTrivialToPrimitiveDefaultInitialize = V;
}

bool isNonTrivialToPrimitiveCopy() const {
  return RecordDeclBits.NonTrivialToPrimitiveCopy;
}

void setNonTrivialToPrimitiveCopy(bool V) {
  RecordDeclBits.NonTrivialToPrimitiveCopy = V;
}

bool isNonTrivialToPrimitiveDestroy() const {
  return RecordDeclBits.NonTrivialToPrimitiveDestroy;
}

void setNonTrivialToPrimitiveDestroy(bool V) {
  RecordDeclBits.NonTrivialToPrimitiveDestroy = V;
}

bool hasNonTrivialToPrimitiveDefaultInitializeCUnion() const {
  return RecordDeclBits.HasNonTrivialToPrimitiveDefaultInitializeCUnion;
}

void setHasNonTrivialToPrimitiveDefaultInitializeCUnion(bool V) {
  RecordDeclBits.HasNonTrivialToPrimitiveDefaultInitializeCUnion = V;
}

bool hasNonTrivialToPrimitiveDestructCUnion() const {
  return RecordDeclBits.HasNonTrivialToPrimitiveDestructCUnion;
}

void setHasNonTrivialToPrimitiveDestructCUnion(bool V) {
  RecordDeclBits.HasNonTrivialToPrimitiveDestructCUnion = V;
}

bool hasNonTrivialToPrimitiveCopyCUnion() const {
  return RecordDeclBits.HasNonTrivialToPrimitiveCopyCUnion;
}

void setHasNonTrivialToPrimitiveCopyCUnion(bool V) {
  RecordDeclBits.HasNonTrivialToPrimitiveCopyCUnion = V;
}

/// Determine whether this class can be passed in registers. In C++ mode,
/// it must have at least one trivial, non-deleted copy or move constructor.
/// FIXME: This should be set as part of completeDefinition.
bool canPassInRegisters() const {
  return getArgPassingRestrictions() == APK_CanPassInRegs;
}

ArgPassingKind getArgPassingRestrictions() const {
  return static_cast<ArgPassingKind>(RecordDeclBits.ArgPassingRestrictions);
}

void setArgPassingRestrictions(ArgPassingKind Kind) {
  RecordDeclBits.ArgPassingRestrictions = Kind;
}

bool isParamDestroyedInCallee() const {
  return RecordDeclBits.ParamDestroyedInCallee;
}

void setParamDestroyedInCallee(bool V) {
  RecordDeclBits.ParamDestroyedInCallee = V;
}

/// Determines whether this declaration represents the
/// injected class name.
///
/// The injected class name in C++ is the name of the class that
/// appears inside the class itself. For example:
///
/// \code
/// struct C {
///   // C is implicitly declared here as a synonym for the class name.
/// };
///
/// C::C c; // same as "C c;"
/// \endcode
bool isInjectedClassName() const;

/// Determine whether this record is a class describing a lambda
/// function object.
bool isLambda() const;

/// Determine whether this record is a record for captured variables in
/// CapturedStmt construct.
bool isCapturedRecord() const;

/// Mark the record as a record for captured variables in CapturedStmt
/// construct.
void setCapturedRecord();

/// Returns the RecordDecl that actually defines
///  this struct/union/class.  When determining whether or not a
///  struct/union/class is completely defined, one should use this
///  method as opposed to 'isCompleteDefinition'.
///  'isCompleteDefinition' indicates whether or not a specific
///  RecordDecl is a completed definition, not whether or not the
///  record type is defined.  This method returns NULL if there is
///  no RecordDecl that defines the struct/union/tag.
RecordDecl *getDefinition() const {
  return cast_or_null<RecordDecl>(TagDecl::getDefinition());
}

/// Returns whether this record is a union, or contains (at any nesting level)
/// a union member. This is used by CMSE to warn about possible information
/// leaks.
bool isOrContainsUnion() const;

// Iterator access to field members. The field iterator only visits
// the non-static data members of this class, ignoring any static
// data members, functions, constructors, destructors, etc.
using field_iterator = specific_decl_iterator<FieldDecl>;
using field_range = llvm::iterator_range<specific_decl_iterator<FieldDecl>>;

field_range fields() const { return field_range(field_begin(), field_end()); }
field_iterator field_begin() const;

field_iterator field_end() const {
  return field_iterator(decl_iterator());
}

// Whether there are any fields (non-static data members) in this record.
bool field_empty() const {
  return field_begin() == field_end();
}

/// Note that the definition of this type is now complete.
virtual void completeDefinition();

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) {
  return K >= firstRecord && K <= lastRecord;
}

/// Get whether or not this is an ms_struct which can
/// be turned on with an attribute, pragma, or -mms-bitfields
/// commandline option.
bool isMsStruct(const ASTContext &C) const;

/// Whether we are allowed to insert extra padding between fields.
/// These padding are added to help AddressSanitizer detect
/// intra-object-overflow bugs.
bool mayInsertExtraPadding(bool EmitRemark = false) const;

/// Finds the first data member which has a name.
/// nullptr is returned if no named data member exists.
const FieldDecl *findFirstNamedDataMember() const;

4103private:
/// Deserialize just the fields.
void LoadFieldsFromExternalStorage() const;
4106};

4108class FileScopeAsmDecl : public Decl {
StringLiteral *AsmString;
SourceLocation RParenLoc;

FileScopeAsmDecl(DeclContext *DC, StringLiteral *asmstring,
                 SourceLocation StartL, SourceLocation EndL)
  : Decl(FileScopeAsm, DC, StartL), AsmString(asmstring), RParenLoc(EndL) {}

virtual void anchor();

4118public:
static FileScopeAsmDecl *Create(ASTContext &C, DeclContext *DC,
                                StringLiteral *Str, SourceLocation AsmLoc,
                                SourceLocation RParenLoc);

static FileScopeAsmDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceLocation getAsmLoc() const { return getLocation(); }
SourceLocation getRParenLoc() const { return RParenLoc; }
void setRParenLoc(SourceLocation L) { RParenLoc = L; }
SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(getAsmLoc(), getRParenLoc());
}

const StringLiteral *getAsmString() const { return AsmString; }
StringLiteral *getAsmString() { return AsmString; }
void setAsmString(StringLiteral *Asm) { AsmString = Asm; }

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == FileScopeAsm; }
4138};

4140/// Represents a block literal declaration, which is like an
4141/// unnamed FunctionDecl.  For example:
4142/// ^{ statement-body }   or   ^(int arg1, float arg2){ statement-body }
4143class BlockDecl : public Decl, public DeclContext {
// This class stores some data in DeclContext::BlockDeclBits
// to save some space. Use the provided accessors to access it.
4146public:
/// A class which contains all the information about a particular
/// captured value.
class Capture {
  enum {
    flag_isByRef = 0x1,
    flag_isNested = 0x2
  };

  /// The variable being captured.
  llvm::PointerIntPair<VarDecl*, 2> VariableAndFlags;

  /// The copy expression, expressed in terms of a DeclRef (or
  /// BlockDeclRef) to the captured variable.  Only required if the
  /// variable has a C++ class type.
  Expr *CopyExpr;

public:
  Capture(VarDecl *variable, bool byRef, bool nested, Expr *copy)
    : VariableAndFlags(variable,
                (byRef ? flag_isByRef : 0) | (nested ? flag_isNested : 0)),
      CopyExpr(copy) {}

  /// The variable being captured.
  VarDecl *getVariable() const { return VariableAndFlags.getPointer(); }

  /// Whether this is a "by ref" capture, i.e. a capture of a __block
  /// variable.
  bool isByRef() const { return VariableAndFlags.getInt() & flag_isByRef; }

  bool isEscapingByref() const {
    return getVariable()->isEscapingByref();
  }

  bool isNonEscapingByref() const {
    return getVariable()->isNonEscapingByref();
  }

  /// Whether this is a nested capture, i.e. the variable captured
  /// is not from outside the immediately enclosing function/block.
  bool isNested() const { return VariableAndFlags.getInt() & flag_isNested; }

  bool hasCopyExpr() const { return CopyExpr != nullptr; }
  Expr *getCopyExpr() const { return CopyExpr; }
  void setCopyExpr(Expr *e) { CopyExpr = e; }
};

4193private:
/// A new[]'d array of pointers to ParmVarDecls for the formal
/// parameters of this function.  This is null if a prototype or if there are
/// no formals.
ParmVarDecl **ParamInfo = nullptr;
unsigned NumParams = 0;

Stmt *Body = nullptr;
TypeSourceInfo *SignatureAsWritten = nullptr;

const Capture *Captures = nullptr;
unsigned NumCaptures = 0;

unsigned ManglingNumber = 0;
Decl *ManglingContextDecl = nullptr;

4209protected:
BlockDecl(DeclContext *DC, SourceLocation CaretLoc);

4212public:
static BlockDecl *Create(ASTContext &C, DeclContext *DC, SourceLocation L);
static BlockDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceLocation getCaretLocation() const { return getLocation(); }

bool isVariadic() const { return BlockDeclBits.IsVariadic; }
void setIsVariadic(bool value) { BlockDeclBits.IsVariadic = value; }

CompoundStmt *getCompoundBody() const { return (CompoundStmt*) Body; }
Stmt *getBody() const override { return (Stmt*) Body; }
void setBody(CompoundStmt *B) { Body = (Stmt*) B; }

void setSignatureAsWritten(TypeSourceInfo *Sig) { SignatureAsWritten = Sig; }
TypeSourceInfo *getSignatureAsWritten() const { return SignatureAsWritten; }

// ArrayRef access to formal parameters.
ArrayRef<ParmVarDecl *> parameters() const {
  return {ParamInfo, getNumParams()};
}
MutableArrayRef<ParmVarDecl *> parameters() {
  return {ParamInfo, getNumParams()};
}

// Iterator access to formal parameters.
using param_iterator = MutableArrayRef<ParmVarDecl *>::iterator;
using param_const_iterator = ArrayRef<ParmVarDecl *>::const_iterator;

bool param_empty() const { return parameters().empty(); }
param_iterator param_begin() { return parameters().begin(); }
param_iterator param_end() { return parameters().end(); }
param_const_iterator param_begin() const { return parameters().begin(); }
param_const_iterator param_end() const { return parameters().end(); }
size_t param_size() const { return parameters().size(); }

unsigned getNumParams() const { return NumParams; }

const ParmVarDecl *getParamDecl(unsigned i) const {
  assert(i < getNumParams() && "Illegal param #")((void)0);
  return ParamInfo[i];
}
ParmVarDecl *getParamDecl(unsigned i) {
  assert(i < getNumParams() && "Illegal param #")((void)0);
  return ParamInfo[i];
}

void setParams(ArrayRef<ParmVarDecl *> NewParamInfo);

/// True if this block (or its nested blocks) captures
/// anything of local storage from its enclosing scopes.
bool hasCaptures() const { return NumCaptures || capturesCXXThis(); }

/// Returns the number of captured variables.
/// Does not include an entry for 'this'.
unsigned getNumCaptures() const { return NumCaptures; }

using capture_const_iterator = ArrayRef<Capture>::const_iterator;

ArrayRef<Capture> captures() const { return {Captures, NumCaptures}; }

capture_const_iterator capture_begin() const { return captures().begin(); }
capture_const_iterator capture_end() const { return captures().end(); }

bool capturesCXXThis() const { return BlockDeclBits.CapturesCXXThis; }
void setCapturesCXXThis(bool B = true) { BlockDeclBits.CapturesCXXThis = B; }

bool blockMissingReturnType() const {
  return BlockDeclBits.BlockMissingReturnType;
}

void setBlockMissingReturnType(bool val = true) {
  BlockDeclBits.BlockMissingReturnType = val;
}

bool isConversionFromLambda() const {
  return BlockDeclBits.IsConversionFromLambda;
}

void setIsConversionFromLambda(bool val = true) {
  BlockDeclBits.IsConversionFromLambda = val;
}

bool doesNotEscape() const { return BlockDeclBits.DoesNotEscape; }
void setDoesNotEscape(bool B = true) { BlockDeclBits.DoesNotEscape = B; }

bool canAvoidCopyToHeap() const {
  return BlockDeclBits.CanAvoidCopyToHeap;
}
void setCanAvoidCopyToHeap(bool B = true) {
  BlockDeclBits.CanAvoidCopyToHeap = B;
}

bool capturesVariable(const VarDecl *var) const;

void setCaptures(ASTContext &Context, ArrayRef<Capture> Captures,
                 bool CapturesCXXThis);

unsigned getBlockManglingNumber() const { return ManglingNumber; }

Decl *getBlockManglingContextDecl() const { return ManglingContextDecl; }

void setBlockMangling(unsigned Number, Decl *Ctx) {
  ManglingNumber = Number;
  ManglingContextDecl = Ctx;
}

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Block; }
static DeclContext *castToDeclContext(const BlockDecl *D) {
  return static_cast<DeclContext *>(const_cast<BlockDecl*>(D));
}
static BlockDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<BlockDecl *>(const_cast<DeclContext*>(DC));
}
4329};

4331/// Represents the body of a CapturedStmt, and serves as its DeclContext.
4332class CapturedDecl final
  : public Decl,
    public DeclContext,
    private llvm::TrailingObjects<CapturedDecl, ImplicitParamDecl *> {
4336protected:
size_t numTrailingObjects(OverloadToken<ImplicitParamDecl>) {
  return NumParams;
}

4341private:
/// The number of parameters to the outlined function.
unsigned NumParams;

/// The position of context parameter in list of parameters.
unsigned ContextParam;

/// The body of the outlined function.
llvm::PointerIntPair<Stmt *, 1, bool> BodyAndNothrow;

explicit CapturedDecl(DeclContext *DC, unsigned NumParams);

ImplicitParamDecl *const *getParams() const {
  return getTrailingObjects<ImplicitParamDecl *>();
}

ImplicitParamDecl **getParams() {
  return getTrailingObjects<ImplicitParamDecl *>();
}

4361public:
friend class ASTDeclReader;
friend class ASTDeclWriter;
friend TrailingObjects;

static CapturedDecl *Create(ASTContext &C, DeclContext *DC,
                            unsigned NumParams);
static CapturedDecl *CreateDeserialized(ASTContext &C, unsigned ID,
                                        unsigned NumParams);

Stmt *getBody() const override;
void setBody(Stmt *B);

bool isNothrow() const;
void setNothrow(bool Nothrow = true);

unsigned getNumParams() const { return NumParams; }

ImplicitParamDecl *getParam(unsigned i) const {
  assert(i < NumParams)((void)0);
  return getParams()[i];
}
void setParam(unsigned i, ImplicitParamDecl *P) {
  assert(i < NumParams)((void)0);
  getParams()[i] = P;
}

// ArrayRef interface to parameters.
ArrayRef<ImplicitParamDecl *> parameters() const {
  return {getParams(), getNumParams()};
}
MutableArrayRef<ImplicitParamDecl *> parameters() {
  return {getParams(), getNumParams()};
}

/// Retrieve the parameter containing captured variables.
ImplicitParamDecl *getContextParam() const {
  assert(ContextParam < NumParams)((void)0);
  return getParam(ContextParam);
}
void setContextParam(unsigned i, ImplicitParamDecl *P) {
  assert(i < NumParams)((void)0);
  ContextParam = i;
  setParam(i, P);
}
unsigned getContextParamPosition() const { return ContextParam; }

using param_iterator = ImplicitParamDecl *const *;
using param_range = llvm::iterator_range<param_iterator>;

/// Retrieve an iterator pointing to the first parameter decl.
param_iterator param_begin() const { return getParams(); }
/// Retrieve an iterator one past the last parameter decl.
param_iterator param_end() const { return getParams() + NumParams; }

// Implement isa/cast/dyncast/etc.
static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Captured; }
static DeclContext *castToDeclContext(const CapturedDecl *D) {
  return static_cast<DeclContext *>(const_cast<CapturedDecl *>(D));
}
static CapturedDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<CapturedDecl *>(const_cast<DeclContext *>(DC));
}
4425};

4427/// Describes a module import declaration, which makes the contents
4428/// of the named module visible in the current translation unit.
4429///
4430/// An import declaration imports the named module (or submodule). For example:
4431/// \code
4432///   @import std.vector;
4433/// \endcode
4434///
4435/// Import declarations can also be implicitly generated from
4436/// \#include/\#import directives.
4437class ImportDecl final : public Decl,
                       llvm::TrailingObjects<ImportDecl, SourceLocation> {
friend class ASTContext;
friend class ASTDeclReader;
friend class ASTReader;
friend TrailingObjects;

/// The imported module.
Module *ImportedModule = nullptr;

/// The next import in the list of imports local to the translation
/// unit being parsed (not loaded from an AST file).
///
/// Includes a bit that indicates whether we have source-location information
/// for each identifier in the module name.
///
/// When the bit is false, we only have a single source location for the
/// end of the import declaration.
llvm::PointerIntPair<ImportDecl *, 1, bool> NextLocalImportAndComplete;

ImportDecl(DeclContext *DC, SourceLocation StartLoc, Module *Imported,
           ArrayRef<SourceLocation> IdentifierLocs);

ImportDecl(DeclContext *DC, SourceLocation StartLoc, Module *Imported,
           SourceLocation EndLoc);

ImportDecl(EmptyShell Empty) : Decl(Import, Empty) {}

bool isImportComplete() const { return NextLocalImportAndComplete.getInt(); }

void setImportComplete(bool C) { NextLocalImportAndComplete.setInt(C); }

/// The next import in the list of imports local to the translation
/// unit being parsed (not loaded from an AST file).
ImportDecl *getNextLocalImport() const {
  return NextLocalImportAndComplete.getPointer();
}

void setNextLocalImport(ImportDecl *Import) {
  NextLocalImportAndComplete.setPointer(Import);
}

4479public:
/// Create a new module import declaration.
static ImportDecl *Create(ASTContext &C, DeclContext *DC,
                          SourceLocation StartLoc, Module *Imported,
                          ArrayRef<SourceLocation> IdentifierLocs);

/// Create a new module import declaration for an implicitly-generated
/// import.
static ImportDecl *CreateImplicit(ASTContext &C, DeclContext *DC,
                                  SourceLocation StartLoc, Module *Imported,
                                  SourceLocation EndLoc);

/// Create a new, deserialized module import declaration.
static ImportDecl *CreateDeserialized(ASTContext &C, unsigned ID,
                                      unsigned NumLocations);

/// Retrieve the module that was imported by the import declaration.
Module *getImportedModule() const { return ImportedModule; }

/// Retrieves the locations of each of the identifiers that make up
/// the complete module name in the import declaration.
///
/// This will return an empty array if the locations of the individual
/// identifiers aren't available.
ArrayRef<SourceLocation> getIdentifierLocs() const;

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__));

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Import; }
4509};

4511/// Represents a C++ Modules TS module export declaration.
4512///
4513/// For example:
4514/// \code
4515///   export void foo();
4516/// \endcode
4517class ExportDecl final : public Decl, public DeclContext {
virtual void anchor();

4520private:
friend class ASTDeclReader;

/// The source location for the right brace (if valid).
SourceLocation RBraceLoc;

ExportDecl(DeclContext *DC, SourceLocation ExportLoc)
    : Decl(Export, DC, ExportLoc), DeclContext(Export),
      RBraceLoc(SourceLocation()) {}

4530public:
static ExportDecl *Create(ASTContext &C, DeclContext *DC,
                          SourceLocation ExportLoc);
static ExportDecl *CreateDeserialized(ASTContext &C, unsigned ID);

SourceLocation getExportLoc() const { return getLocation(); }
SourceLocation getRBraceLoc() const { return RBraceLoc; }
void setRBraceLoc(SourceLocation L) { RBraceLoc = L; }

bool hasBraces() const { return RBraceLoc.isValid(); }

SourceLocation getEndLoc() const LLVM_READONLY__attribute__((__pure__)) {
  if (hasBraces())
    return RBraceLoc;
  // No braces: get the end location of the (only) declaration in context
  // (if present).
  return decls_empty() ? getLocation() : decls_begin()->getEndLoc();
}

SourceRange getSourceRange() const override LLVM_READONLY__attribute__((__pure__)) {
  return SourceRange(getLocation(), getEndLoc());
}

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Export; }
static DeclContext *castToDeclContext(const ExportDecl *D) {
  return static_cast<DeclContext *>(const_cast<ExportDecl*>(D));
}
static ExportDecl *castFromDeclContext(const DeclContext *DC) {
  return static_cast<ExportDecl *>(const_cast<DeclContext*>(DC));
}
4561};

4563/// Represents an empty-declaration.
4564class EmptyDecl : public Decl {
EmptyDecl(DeclContext *DC, SourceLocation L) : Decl(Empty, DC, L) {}

virtual void anchor();

4569public:
static EmptyDecl *Create(ASTContext &C, DeclContext *DC,
                         SourceLocation L);
static EmptyDecl *CreateDeserialized(ASTContext &C, unsigned ID);

static bool classof(const Decl *D) { return classofKind(D->getKind()); }
static bool classofKind(Kind K) { return K == Empty; }
4576};

4578/// Insertion operator for diagnostics.  This allows sending NamedDecl's
4579/// into a diagnostic with <<.
4580inline const StreamingDiagnostic &operator<<(const StreamingDiagnostic &PD,
                                           const NamedDecl *ND) {
PD.AddTaggedVal(reinterpret_cast<intptr_t>(ND),
                DiagnosticsEngine::ak_nameddecl);
return PD;
4585}

4587template<typename decl_type>
4588void Redeclarable<decl_type>::setPreviousDecl(decl_type *PrevDecl) {
// Note: This routine is implemented here because we need both NamedDecl
// and Redeclarable to be defined.
assert(RedeclLink.isFirst() &&((void)0)
       "setPreviousDecl on a decl already in a redeclaration chain")((void)0);

if (PrevDecl) {
  // Point to previous. Make sure that this is actually the most recent
  // redeclaration, or we can build invalid chains. If the most recent
  // redeclaration is invalid, it won't be PrevDecl, but we want it anyway.
  First = PrevDecl->getFirstDecl();
  assert(First->RedeclLink.isFirst() && "Expected first")((void)0);
  decl_type *MostRecent = First->getNextRedeclaration();
  RedeclLink = PreviousDeclLink(cast<decl_type>(MostRecent));

  // If the declaration was previously visible, a redeclaration of it remains
  // visible even if it wouldn't be visible by itself.
  static_cast<decl_type*>(this)->IdentifierNamespace |=
    MostRecent->getIdentifierNamespace() &
    (Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Type);
} else {
  // Make this first.
  First = static_cast<decl_type*>(this);
}

// First one will point to this one as latest.
First->RedeclLink.setLatest(static_cast<decl_type*>(this));

assert(!isa<NamedDecl>(static_cast<decl_type*>(this)) ||((void)0)
       cast<NamedDecl>(static_cast<decl_type*>(this))->isLinkageValid())((void)0);
4618}

4620// Inline function definitions.

4622/// Check if the given decl is complete.
4623///
4624/// We use this function to break a cycle between the inline definitions in
4625/// Type.h and Decl.h.
4626inline bool IsEnumDeclComplete(EnumDecl *ED) {
return ED->isComplete();
4628}

4630/// Check if the given decl is scoped.
4631///
4632/// We use this function to break a cycle between the inline definitions in
4633/// Type.h and Decl.h.
4634inline bool IsEnumDeclScoped(EnumDecl *ED) {
return ED->isScoped();
4636}

4638/// OpenMP variants are mangled early based on their OpenMP context selector.
4639/// The new name looks likes this:
4640///  <name> + OpenMPVariantManglingSeparatorStr + <mangled OpenMP context>
4641static constexpr StringRef getOpenMPVariantManglingSeparatorStr() {
return "$ompvariant";
4643}

4645} // namespace clang

4647#endif // LLVM_CLANG_AST_DECL_H

←

/usr/src/gnu/usr.bin/clang/libclangSema/../../../llvm/clang/include/clang/Basic/Specifiers.h

1//===--- Specifiers.h - Declaration and Type Specifiers ---------*- 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/// \file
10/// Defines various enumerations that describe declaration and
11/// type specifiers.
12///
13//===----------------------------------------------------------------------===//

15#ifndef LLVM_CLANG_BASIC_SPECIFIERS_H
16#define LLVM_CLANG_BASIC_SPECIFIERS_H

18#include "llvm/ADT/StringRef.h"
19#include "llvm/Support/DataTypes.h"
20#include "llvm/Support/ErrorHandling.h"

22namespace clang {

/// Define the meaning of possible values of the kind in ExplicitSpecifier.
enum class ExplicitSpecKind : unsigned {
  ResolvedFalse,
  ResolvedTrue,
  Unresolved,
};

/// Define the kind of constexpr specifier.
enum class ConstexprSpecKind { Unspecified, Constexpr, Consteval, Constinit };

/// Specifies the width of a type, e.g., short, long, or long long.
enum class TypeSpecifierWidth { Unspecified, Short, Long, LongLong };

/// Specifies the signedness of a type, e.g., signed or unsigned.
enum class TypeSpecifierSign { Unspecified, Signed, Unsigned };

enum class TypeSpecifiersPipe { Unspecified, Pipe };

/// Specifies the kind of type.
enum TypeSpecifierType {
  TST_unspecified,
  TST_void,
  TST_char,
  TST_wchar,        // C++ wchar_t
  TST_char8,        // C++20 char8_t (proposed)
  TST_char16,       // C++11 char16_t
  TST_char32,       // C++11 char32_t
  TST_int,
  TST_int128,
  TST_extint,       // Extended Int types.
  TST_half,         // OpenCL half, ARM NEON __fp16
  TST_Float16,      // C11 extension ISO/IEC TS 18661-3
  TST_Accum,        // ISO/IEC JTC1 SC22 WG14 N1169 Extension
  TST_Fract,
  TST_BFloat16,
  TST_float,
  TST_double,
  TST_float128,
  TST_bool,         // _Bool
  TST_decimal32,    // _Decimal32
  TST_decimal64,    // _Decimal64
  TST_decimal128,   // _Decimal128
  TST_enum,
  TST_union,
  TST_struct,
  TST_class,        // C++ class type
  TST_interface,    // C++ (Microsoft-specific) __interface type
  TST_typename,     // Typedef, C++ class-name or enum name, etc.
  TST_typeofType,
  TST_typeofExpr,
  TST_decltype,         // C++11 decltype
  TST_underlyingType,   // __underlying_type for C++11
  TST_auto,             // C++11 auto
  TST_decltype_auto,    // C++1y decltype(auto)
  TST_auto_type,        // __auto_type extension
  TST_unknown_anytype,  // __unknown_anytype extension
  TST_atomic,           // C11 _Atomic
81#define GENERIC_IMAGE_TYPE(ImgType, Id) TST_##ImgType##_t, // OpenCL image types
82#include "clang/Basic/OpenCLImageTypes.def"
  TST_error // erroneous type
};

/// Structure that packs information about the type specifiers that
/// were written in a particular type specifier sequence.
struct WrittenBuiltinSpecs {
  static_assert(TST_error < 1 << 6, "Type bitfield not wide enough for TST");
  /*DeclSpec::TST*/ unsigned Type  : 6;
  /*DeclSpec::TSS*/ unsigned Sign  : 2;
  /*TypeSpecifierWidth*/ unsigned Width : 2;
  unsigned ModeAttr : 1;
};

/// A C++ access specifier (public, private, protected), plus the
/// special value "none" which means different things in different contexts.
enum AccessSpecifier {
  AS_public,
  AS_protected,
  AS_private,
  AS_none
};

/// The categorization of expression values, currently following the
/// C++11 scheme.
enum ExprValueKind {
  /// A pr-value expression (in the C++11 taxonomy)
  /// produces a temporary value.
  VK_PRValue,

  /// An l-value expression is a reference to an object with
  /// independent storage.
  VK_LValue,

  /// An x-value expression is a reference to an object with
  /// independent storage but which can be "moved", i.e.
  /// efficiently cannibalized for its resources.
  VK_XValue
};

/// A further classification of the kind of object referenced by an
/// l-value or x-value.
enum ExprObjectKind {
  /// An ordinary object is located at an address in memory.
  OK_Ordinary,

  /// A bitfield object is a bitfield on a C or C++ record.
  OK_BitField,

  /// A vector component is an element or range of elements on a vector.
  OK_VectorComponent,

  /// An Objective-C property is a logical field of an Objective-C
  /// object which is read and written via Objective-C method calls.
  OK_ObjCProperty,

  /// An Objective-C array/dictionary subscripting which reads an
  /// object or writes at the subscripted array/dictionary element via
  /// Objective-C method calls.
  OK_ObjCSubscript,

  /// A matrix component is a single element of a matrix.
  OK_MatrixComponent
};

/// The reason why a DeclRefExpr does not constitute an odr-use.
enum NonOdrUseReason {
  /// This is an odr-use.
  NOUR_None = 0,
  /// This name appears in an unevaluated operand.
  NOUR_Unevaluated,
  /// This name appears as a potential result of an lvalue-to-rvalue
  /// conversion that is a constant expression.
  NOUR_Constant,
  /// This name appears as a potential result of a discarded value
  /// expression.
  NOUR_Discarded,
};

/// Describes the kind of template specialization that a
/// particular template specialization declaration represents.
enum TemplateSpecializationKind {
  /// This template specialization was formed from a template-id but
  /// has not yet been declared, defined, or instantiated.
  TSK_Undeclared = 0,
  /// This template specialization was implicitly instantiated from a
  /// template. (C++ [temp.inst]).
  TSK_ImplicitInstantiation,
  /// This template specialization was declared or defined by an
  /// explicit specialization (C++ [temp.expl.spec]) or partial
  /// specialization (C++ [temp.class.spec]).
  TSK_ExplicitSpecialization,
  /// This template specialization was instantiated from a template
  /// due to an explicit instantiation declaration request
  /// (C++11 [temp.explicit]).
  TSK_ExplicitInstantiationDeclaration,
  /// This template specialization was instantiated from a template
  /// due to an explicit instantiation definition request
  /// (C++ [temp.explicit]).
  TSK_ExplicitInstantiationDefinition
};

/// Determine whether this template specialization kind refers
/// to an instantiation of an entity (as opposed to a non-template or
/// an explicit specialization).
inline bool isTemplateInstantiation(TemplateSpecializationKind Kind) {
  return Kind != TSK_Undeclared && Kind != TSK_ExplicitSpecialization;
39
←
Assuming 'Kind' is not equal to TSK_Undeclared→
40
←
Assuming 'Kind' is not equal to TSK_ExplicitSpecialization→
41
←
Returning the value 1, which participates in a condition later→
}

/// True if this template specialization kind is an explicit
/// specialization, explicit instantiation declaration, or explicit
/// instantiation definition.
inline bool isTemplateExplicitInstantiationOrSpecialization(
    TemplateSpecializationKind Kind) {
  switch (Kind) {
  case TSK_ExplicitSpecialization:
  case TSK_ExplicitInstantiationDeclaration:
  case TSK_ExplicitInstantiationDefinition:
    return true;

  case TSK_Undeclared:
  case TSK_ImplicitInstantiation:
    return false;
  }
  llvm_unreachable("bad template specialization kind")__builtin_unreachable();
}

/// Thread storage-class-specifier.
enum ThreadStorageClassSpecifier {
  TSCS_unspecified,
  /// GNU __thread.
  TSCS___thread,
  /// C++11 thread_local. Implies 'static' at block scope, but not at
  /// class scope.
  TSCS_thread_local,
  /// C11 _Thread_local. Must be combined with either 'static' or 'extern'
  /// if used at block scope.
  TSCS__Thread_local
};

/// Storage classes.
enum StorageClass {
  // These are legal on both functions and variables.
  SC_None,
  SC_Extern,
  SC_Static,
  SC_PrivateExtern,

  // These are only legal on variables.
  SC_Auto,
  SC_Register
};

/// Checks whether the given storage class is legal for functions.
inline bool isLegalForFunction(StorageClass SC) {
  return SC <= SC_PrivateExtern;
}

/// Checks whether the given storage class is legal for variables.
inline bool isLegalForVariable(StorageClass SC) {
  return true;
}

/// In-class initialization styles for non-static data members.
enum InClassInitStyle {
  ICIS_NoInit,   ///< No in-class initializer.
  ICIS_CopyInit, ///< Copy initialization.
  ICIS_ListInit  ///< Direct list-initialization.
};

/// CallingConv - Specifies the calling convention that a function uses.
enum CallingConv {
  CC_C,           // __attribute__((cdecl))
  CC_X86StdCall,  // __attribute__((stdcall))
  CC_X86FastCall, // __attribute__((fastcall))
  CC_X86ThisCall, // __attribute__((thiscall))
  CC_X86VectorCall, // __attribute__((vectorcall))
  CC_X86Pascal,   // __attribute__((pascal))
  CC_Win64,       // __attribute__((ms_abi))
  CC_X86_64SysV,  // __attribute__((sysv_abi))
  CC_X86RegCall, // __attribute__((regcall))
  CC_AAPCS,       // __attribute__((pcs("aapcs")))
  CC_AAPCS_VFP,   // __attribute__((pcs("aapcs-vfp")))
  CC_IntelOclBicc, // __attribute__((intel_ocl_bicc))
  CC_SpirFunction, // default for OpenCL functions on SPIR target
  CC_OpenCLKernel, // inferred for OpenCL kernels
  CC_Swift,        // __attribute__((swiftcall))
  CC_SwiftAsync,        // __attribute__((swiftasynccall))
  CC_PreserveMost, // __attribute__((preserve_most))
  CC_PreserveAll,  // __attribute__((preserve_all))
  CC_AArch64VectorCall, // __attribute__((aarch64_vector_pcs))
};

/// Checks whether the given calling convention supports variadic
/// calls. Unprototyped calls also use the variadic call rules.
inline bool supportsVariadicCall(CallingConv CC) {
  switch (CC) {
  case CC_X86StdCall:
  case CC_X86FastCall:
  case CC_X86ThisCall:
  case CC_X86RegCall:
  case CC_X86Pascal:
  case CC_X86VectorCall:
  case CC_SpirFunction:
  case CC_OpenCLKernel:
  case CC_Swift:
  case CC_SwiftAsync:
    return false;
  default:
    return true;
  }
}

/// The storage duration for an object (per C++ [basic.stc]).
enum StorageDuration {
  SD_FullExpression, ///< Full-expression storage duration (for temporaries).
  SD_Automatic,      ///< Automatic storage duration (most local variables).
  SD_Thread,         ///< Thread storage duration.
  SD_Static,         ///< Static storage duration.
  SD_Dynamic         ///< Dynamic storage duration.
};

/// Describes the nullability of a particular type.
enum class NullabilityKind : uint8_t {
  /// Values of this type can never be null.
  NonNull = 0,
  /// Values of this type can be null.
  Nullable,
  /// Whether values of this type can be null is (explicitly)
  /// unspecified. This captures a (fairly rare) case where we
  /// can't conclude anything about the nullability of the type even
  /// though it has been considered.
  Unspecified,
  // Generally behaves like Nullable, except when used in a block parameter
  // that was imported into a swift async method. There, swift will assume
  // that the parameter can get null even if no error occured. _Nullable
  // parameters are assumed to only get null on error.
  NullableResult,
};

/// Return true if \p L has a weaker nullability annotation than \p R. The
/// ordering is: Unspecified < Nullable < NonNull.
inline bool hasWeakerNullability(NullabilityKind L, NullabilityKind R) {
  return uint8_t(L) > uint8_t(R);
}

/// Retrieve the spelling of the given nullability kind.
llvm::StringRef getNullabilitySpelling(NullabilityKind kind,
                                       bool isContextSensitive = false);

/// Kinds of parameter ABI.
enum class ParameterABI {
  /// This parameter uses ordinary ABI rules for its type.
  Ordinary,

  /// This parameter (which must have pointer type) is a Swift
  /// indirect result parameter.
  SwiftIndirectResult,

  /// This parameter (which must have pointer-to-pointer type) uses
  /// the special Swift error-result ABI treatment.  There can be at
  /// most one parameter on a given function that uses this treatment.
  SwiftErrorResult,

  /// This parameter (which must have pointer type) uses the special
  /// Swift context-pointer ABI treatment.  There can be at
  /// most one parameter on a given function that uses this treatment.
  SwiftContext,

  /// This parameter (which must have pointer type) uses the special
  /// Swift asynchronous context-pointer ABI treatment.  There can be at
  /// most one parameter on a given function that uses this treatment.
  SwiftAsyncContext,
};

/// Assigned inheritance model for a class in the MS C++ ABI. Must match order
/// of spellings in MSInheritanceAttr.
enum class MSInheritanceModel {
  Single = 0,
  Multiple = 1,
  Virtual = 2,
  Unspecified = 3,
};

llvm::StringRef getParameterABISpelling(ParameterABI kind);

inline llvm::StringRef getAccessSpelling(AccessSpecifier AS) {
  switch (AS) {
  case AccessSpecifier::AS_public:
    return "public";
  case AccessSpecifier::AS_protected:
    return "protected";
  case AccessSpecifier::AS_private:
    return "private";
  case AccessSpecifier::AS_none:
    return {};
  }
  llvm_unreachable("Unknown AccessSpecifier")__builtin_unreachable();
}
381} // end namespace clang

383#endif // LLVM_CLANG_BASIC_SPECIFIERS_H