1 //===------ SemaDeclCXX.cpp - Semantic Analysis for C++ Declarations ------===//
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
7 //===----------------------------------------------------------------------===//
9 // This file implements semantic analysis for C++ declarations.
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/STLExtras.h"
42 #include "llvm/ADT/SmallString.h"
43 #include "llvm/ADT/StringExtras.h"
47 using namespace clang;
49 //===----------------------------------------------------------------------===//
50 // CheckDefaultArgumentVisitor
51 //===----------------------------------------------------------------------===//
54 /// CheckDefaultArgumentVisitor - C++ [dcl.fct.default] Traverses
55 /// the default argument of a parameter to determine whether it
56 /// contains any ill-formed subexpressions. For example, this will
57 /// diagnose the use of local variables or parameters within the
58 /// default argument expression.
59 class CheckDefaultArgumentVisitor
60 : public StmtVisitor<CheckDefaultArgumentVisitor, bool> {
65 CheckDefaultArgumentVisitor(Expr *defarg, Sema *s)
66 : DefaultArg(defarg), S(s) {}
68 bool VisitExpr(Expr *Node);
69 bool VisitDeclRefExpr(DeclRefExpr *DRE);
70 bool VisitCXXThisExpr(CXXThisExpr *ThisE);
71 bool VisitLambdaExpr(LambdaExpr *Lambda);
72 bool VisitPseudoObjectExpr(PseudoObjectExpr *POE);
75 /// VisitExpr - Visit all of the children of this expression.
76 bool CheckDefaultArgumentVisitor::VisitExpr(Expr *Node) {
77 bool IsInvalid = false;
78 for (Stmt *SubStmt : Node->children())
79 IsInvalid |= Visit(SubStmt);
83 /// VisitDeclRefExpr - Visit a reference to a declaration, to
84 /// determine whether this declaration can be used in the default
85 /// argument expression.
86 bool CheckDefaultArgumentVisitor::VisitDeclRefExpr(DeclRefExpr *DRE) {
87 NamedDecl *Decl = DRE->getDecl();
88 if (ParmVarDecl *Param = dyn_cast<ParmVarDecl>(Decl)) {
89 // C++ [dcl.fct.default]p9
90 // Default arguments are evaluated each time the function is
91 // called. The order of evaluation of function arguments is
92 // unspecified. Consequently, parameters of a function shall not
93 // be used in default argument expressions, even if they are not
94 // evaluated. Parameters of a function declared before a default
95 // argument expression are in scope and can hide namespace and
96 // class member names.
97 return S->Diag(DRE->getBeginLoc(),
98 diag::err_param_default_argument_references_param)
99 << Param->getDeclName() << DefaultArg->getSourceRange();
100 } else if (VarDecl *VDecl = dyn_cast<VarDecl>(Decl)) {
101 // C++ [dcl.fct.default]p7
102 // Local variables shall not be used in default argument
104 if (VDecl->isLocalVarDecl())
105 return S->Diag(DRE->getBeginLoc(),
106 diag::err_param_default_argument_references_local)
107 << VDecl->getDeclName() << DefaultArg->getSourceRange();
113 /// VisitCXXThisExpr - Visit a C++ "this" expression.
114 bool CheckDefaultArgumentVisitor::VisitCXXThisExpr(CXXThisExpr *ThisE) {
115 // C++ [dcl.fct.default]p8:
116 // The keyword this shall not be used in a default argument of a
118 return S->Diag(ThisE->getBeginLoc(),
119 diag::err_param_default_argument_references_this)
120 << ThisE->getSourceRange();
123 bool CheckDefaultArgumentVisitor::VisitPseudoObjectExpr(PseudoObjectExpr *POE) {
124 bool Invalid = false;
125 for (PseudoObjectExpr::semantics_iterator
126 i = POE->semantics_begin(), e = POE->semantics_end(); i != e; ++i) {
129 // Look through bindings.
130 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
131 E = OVE->getSourceExpr();
132 assert(E && "pseudo-object binding without source expression?");
140 bool CheckDefaultArgumentVisitor::VisitLambdaExpr(LambdaExpr *Lambda) {
141 // C++11 [expr.lambda.prim]p13:
142 // A lambda-expression appearing in a default argument shall not
143 // implicitly or explicitly capture any entity.
144 if (Lambda->capture_begin() == Lambda->capture_end())
147 return S->Diag(Lambda->getBeginLoc(), diag::err_lambda_capture_default_arg);
152 Sema::ImplicitExceptionSpecification::CalledDecl(SourceLocation CallLoc,
153 const CXXMethodDecl *Method) {
154 // If we have an MSAny spec already, don't bother.
155 if (!Method || ComputedEST == EST_MSAny)
158 const FunctionProtoType *Proto
159 = Method->getType()->getAs<FunctionProtoType>();
160 Proto = Self->ResolveExceptionSpec(CallLoc, Proto);
164 ExceptionSpecificationType EST = Proto->getExceptionSpecType();
166 // If we have a throw-all spec at this point, ignore the function.
167 if (ComputedEST == EST_None)
170 if (EST == EST_None && Method->hasAttr<NoThrowAttr>())
171 EST = EST_BasicNoexcept;
175 case EST_Uninstantiated:
176 case EST_Unevaluated:
177 llvm_unreachable("should not see unresolved exception specs here");
179 // If this function can throw any exceptions, make a note of that.
182 // FIXME: Whichever we see last of MSAny and None determines our result.
183 // We should make a consistent, order-independent choice here.
187 case EST_NoexceptFalse:
189 ComputedEST = EST_None;
191 // FIXME: If the call to this decl is using any of its default arguments, we
192 // need to search them for potentially-throwing calls.
193 // If this function has a basic noexcept, it doesn't affect the outcome.
194 case EST_BasicNoexcept:
195 case EST_NoexceptTrue:
198 // If we're still at noexcept(true) and there's a throw() callee,
199 // change to that specification.
200 case EST_DynamicNone:
201 if (ComputedEST == EST_BasicNoexcept)
202 ComputedEST = EST_DynamicNone;
204 case EST_DependentNoexcept:
206 "should not generate implicit declarations for dependent cases");
210 assert(EST == EST_Dynamic && "EST case not considered earlier.");
211 assert(ComputedEST != EST_None &&
212 "Shouldn't collect exceptions when throw-all is guaranteed.");
213 ComputedEST = EST_Dynamic;
214 // Record the exceptions in this function's exception specification.
215 for (const auto &E : Proto->exceptions())
216 if (ExceptionsSeen.insert(Self->Context.getCanonicalType(E)).second)
217 Exceptions.push_back(E);
220 void Sema::ImplicitExceptionSpecification::CalledStmt(Stmt *S) {
221 if (!S || ComputedEST == EST_MSAny)
226 // C++0x [except.spec]p14:
227 // [An] implicit exception-specification specifies the type-id T if and
228 // only if T is allowed by the exception-specification of a function directly
229 // invoked by f's implicit definition; f shall allow all exceptions if any
230 // function it directly invokes allows all exceptions, and f shall allow no
231 // exceptions if every function it directly invokes allows no exceptions.
233 // Note in particular that if an implicit exception-specification is generated
234 // for a function containing a throw-expression, that specification can still
235 // be noexcept(true).
237 // Note also that 'directly invoked' is not defined in the standard, and there
238 // is no indication that we should only consider potentially-evaluated calls.
240 // Ultimately we should implement the intent of the standard: the exception
241 // specification should be the set of exceptions which can be thrown by the
242 // implicit definition. For now, we assume that any non-nothrow expression can
243 // throw any exception.
245 if (Self->canThrow(S))
246 ComputedEST = EST_None;
250 Sema::SetParamDefaultArgument(ParmVarDecl *Param, Expr *Arg,
251 SourceLocation EqualLoc) {
252 if (RequireCompleteType(Param->getLocation(), Param->getType(),
253 diag::err_typecheck_decl_incomplete_type)) {
254 Param->setInvalidDecl();
258 // C++ [dcl.fct.default]p5
259 // A default argument expression is implicitly converted (clause
260 // 4) to the parameter type. The default argument expression has
261 // the same semantic constraints as the initializer expression in
262 // a declaration of a variable of the parameter type, using the
263 // copy-initialization semantics (8.5).
264 InitializedEntity Entity = InitializedEntity::InitializeParameter(Context,
266 InitializationKind Kind = InitializationKind::CreateCopy(Param->getLocation(),
268 InitializationSequence InitSeq(*this, Entity, Kind, Arg);
269 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Arg);
270 if (Result.isInvalid())
272 Arg = Result.getAs<Expr>();
274 CheckCompletedExpr(Arg, EqualLoc);
275 Arg = MaybeCreateExprWithCleanups(Arg);
277 // Okay: add the default argument to the parameter
278 Param->setDefaultArg(Arg);
280 // We have already instantiated this parameter; provide each of the
281 // instantiations with the uninstantiated default argument.
282 UnparsedDefaultArgInstantiationsMap::iterator InstPos
283 = UnparsedDefaultArgInstantiations.find(Param);
284 if (InstPos != UnparsedDefaultArgInstantiations.end()) {
285 for (unsigned I = 0, N = InstPos->second.size(); I != N; ++I)
286 InstPos->second[I]->setUninstantiatedDefaultArg(Arg);
288 // We're done tracking this parameter's instantiations.
289 UnparsedDefaultArgInstantiations.erase(InstPos);
295 /// ActOnParamDefaultArgument - Check whether the default argument
296 /// provided for a function parameter is well-formed. If so, attach it
297 /// to the parameter declaration.
299 Sema::ActOnParamDefaultArgument(Decl *param, SourceLocation EqualLoc,
301 if (!param || !DefaultArg)
304 ParmVarDecl *Param = cast<ParmVarDecl>(param);
305 UnparsedDefaultArgLocs.erase(Param);
307 // Default arguments are only permitted in C++
308 if (!getLangOpts().CPlusPlus) {
309 Diag(EqualLoc, diag::err_param_default_argument)
310 << DefaultArg->getSourceRange();
311 Param->setInvalidDecl();
315 // Check for unexpanded parameter packs.
316 if (DiagnoseUnexpandedParameterPack(DefaultArg, UPPC_DefaultArgument)) {
317 Param->setInvalidDecl();
321 // C++11 [dcl.fct.default]p3
322 // A default argument expression [...] shall not be specified for a
324 if (Param->isParameterPack()) {
325 Diag(EqualLoc, diag::err_param_default_argument_on_parameter_pack)
326 << DefaultArg->getSourceRange();
330 // Check that the default argument is well-formed
331 CheckDefaultArgumentVisitor DefaultArgChecker(DefaultArg, this);
332 if (DefaultArgChecker.Visit(DefaultArg)) {
333 Param->setInvalidDecl();
337 SetParamDefaultArgument(Param, DefaultArg, EqualLoc);
340 /// ActOnParamUnparsedDefaultArgument - We've seen a default
341 /// argument for a function parameter, but we can't parse it yet
342 /// because we're inside a class definition. Note that this default
343 /// argument will be parsed later.
344 void Sema::ActOnParamUnparsedDefaultArgument(Decl *param,
345 SourceLocation EqualLoc,
346 SourceLocation ArgLoc) {
350 ParmVarDecl *Param = cast<ParmVarDecl>(param);
351 Param->setUnparsedDefaultArg();
352 UnparsedDefaultArgLocs[Param] = ArgLoc;
355 /// ActOnParamDefaultArgumentError - Parsing or semantic analysis of
356 /// the default argument for the parameter param failed.
357 void Sema::ActOnParamDefaultArgumentError(Decl *param,
358 SourceLocation EqualLoc) {
362 ParmVarDecl *Param = cast<ParmVarDecl>(param);
363 Param->setInvalidDecl();
364 UnparsedDefaultArgLocs.erase(Param);
365 Param->setDefaultArg(new(Context)
366 OpaqueValueExpr(EqualLoc,
367 Param->getType().getNonReferenceType(),
371 /// CheckExtraCXXDefaultArguments - Check for any extra default
372 /// arguments in the declarator, which is not a function declaration
373 /// or definition and therefore is not permitted to have default
374 /// arguments. This routine should be invoked for every declarator
375 /// that is not a function declaration or definition.
376 void Sema::CheckExtraCXXDefaultArguments(Declarator &D) {
377 // C++ [dcl.fct.default]p3
378 // A default argument expression shall be specified only in the
379 // parameter-declaration-clause of a function declaration or in a
380 // template-parameter (14.1). It shall not be specified for a
381 // parameter pack. If it is specified in a
382 // parameter-declaration-clause, it shall not occur within a
383 // declarator or abstract-declarator of a parameter-declaration.
384 bool MightBeFunction = D.isFunctionDeclarationContext();
385 for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
386 DeclaratorChunk &chunk = D.getTypeObject(i);
387 if (chunk.Kind == DeclaratorChunk::Function) {
388 if (MightBeFunction) {
389 // This is a function declaration. It can have default arguments, but
390 // keep looking in case its return type is a function type with default
392 MightBeFunction = false;
395 for (unsigned argIdx = 0, e = chunk.Fun.NumParams; argIdx != e;
397 ParmVarDecl *Param = cast<ParmVarDecl>(chunk.Fun.Params[argIdx].Param);
398 if (Param->hasUnparsedDefaultArg()) {
399 std::unique_ptr<CachedTokens> Toks =
400 std::move(chunk.Fun.Params[argIdx].DefaultArgTokens);
402 if (Toks->size() > 1)
403 SR = SourceRange((*Toks)[1].getLocation(),
404 Toks->back().getLocation());
406 SR = UnparsedDefaultArgLocs[Param];
407 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
409 } else if (Param->getDefaultArg()) {
410 Diag(Param->getLocation(), diag::err_param_default_argument_nonfunc)
411 << Param->getDefaultArg()->getSourceRange();
412 Param->setDefaultArg(nullptr);
415 } else if (chunk.Kind != DeclaratorChunk::Paren) {
416 MightBeFunction = false;
421 static bool functionDeclHasDefaultArgument(const FunctionDecl *FD) {
422 for (unsigned NumParams = FD->getNumParams(); NumParams > 0; --NumParams) {
423 const ParmVarDecl *PVD = FD->getParamDecl(NumParams-1);
424 if (!PVD->hasDefaultArg())
426 if (!PVD->hasInheritedDefaultArg())
432 /// MergeCXXFunctionDecl - Merge two declarations of the same C++
433 /// function, once we already know that they have the same
434 /// type. Subroutine of MergeFunctionDecl. Returns true if there was an
435 /// error, false otherwise.
436 bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
438 bool Invalid = false;
440 // The declaration context corresponding to the scope is the semantic
441 // parent, unless this is a local function declaration, in which case
442 // it is that surrounding function.
443 DeclContext *ScopeDC = New->isLocalExternDecl()
444 ? New->getLexicalDeclContext()
445 : New->getDeclContext();
447 // Find the previous declaration for the purpose of default arguments.
448 FunctionDecl *PrevForDefaultArgs = Old;
449 for (/**/; PrevForDefaultArgs;
450 // Don't bother looking back past the latest decl if this is a local
451 // extern declaration; nothing else could work.
452 PrevForDefaultArgs = New->isLocalExternDecl()
454 : PrevForDefaultArgs->getPreviousDecl()) {
455 // Ignore hidden declarations.
456 if (!LookupResult::isVisible(*this, PrevForDefaultArgs))
459 if (S && !isDeclInScope(PrevForDefaultArgs, ScopeDC, S) &&
460 !New->isCXXClassMember()) {
461 // Ignore default arguments of old decl if they are not in
462 // the same scope and this is not an out-of-line definition of
463 // a member function.
467 if (PrevForDefaultArgs->isLocalExternDecl() != New->isLocalExternDecl()) {
468 // If only one of these is a local function declaration, then they are
469 // declared in different scopes, even though isDeclInScope may think
470 // they're in the same scope. (If both are local, the scope check is
471 // sufficient, and if neither is local, then they are in the same scope.)
475 // We found the right previous declaration.
479 // C++ [dcl.fct.default]p4:
480 // For non-template functions, default arguments can be added in
481 // later declarations of a function in the same
482 // scope. Declarations in different scopes have completely
483 // distinct sets of default arguments. That is, declarations in
484 // inner scopes do not acquire default arguments from
485 // declarations in outer scopes, and vice versa. In a given
486 // function declaration, all parameters subsequent to a
487 // parameter with a default argument shall have default
488 // arguments supplied in this or previous declarations. A
489 // default argument shall not be redefined by a later
490 // declaration (not even to the same value).
492 // C++ [dcl.fct.default]p6:
493 // Except for member functions of class templates, the default arguments
494 // in a member function definition that appears outside of the class
495 // definition are added to the set of default arguments provided by the
496 // member function declaration in the class definition.
497 for (unsigned p = 0, NumParams = PrevForDefaultArgs
498 ? PrevForDefaultArgs->getNumParams()
500 p < NumParams; ++p) {
501 ParmVarDecl *OldParam = PrevForDefaultArgs->getParamDecl(p);
502 ParmVarDecl *NewParam = New->getParamDecl(p);
504 bool OldParamHasDfl = OldParam ? OldParam->hasDefaultArg() : false;
505 bool NewParamHasDfl = NewParam->hasDefaultArg();
507 if (OldParamHasDfl && NewParamHasDfl) {
508 unsigned DiagDefaultParamID =
509 diag::err_param_default_argument_redefinition;
511 // MSVC accepts that default parameters be redefined for member functions
512 // of template class. The new default parameter's value is ignored.
514 if (getLangOpts().MicrosoftExt) {
515 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(New);
516 if (MD && MD->getParent()->getDescribedClassTemplate()) {
517 // Merge the old default argument into the new parameter.
518 NewParam->setHasInheritedDefaultArg();
519 if (OldParam->hasUninstantiatedDefaultArg())
520 NewParam->setUninstantiatedDefaultArg(
521 OldParam->getUninstantiatedDefaultArg());
523 NewParam->setDefaultArg(OldParam->getInit());
524 DiagDefaultParamID = diag::ext_param_default_argument_redefinition;
529 // FIXME: If we knew where the '=' was, we could easily provide a fix-it
530 // hint here. Alternatively, we could walk the type-source information
531 // for NewParam to find the last source location in the type... but it
532 // isn't worth the effort right now. This is the kind of test case that
533 // is hard to get right:
535 // void g(int (*fp)(int) = f);
536 // void g(int (*fp)(int) = &f);
537 Diag(NewParam->getLocation(), DiagDefaultParamID)
538 << NewParam->getDefaultArgRange();
540 // Look for the function declaration where the default argument was
541 // actually written, which may be a declaration prior to Old.
542 for (auto Older = PrevForDefaultArgs;
543 OldParam->hasInheritedDefaultArg(); /**/) {
544 Older = Older->getPreviousDecl();
545 OldParam = Older->getParamDecl(p);
548 Diag(OldParam->getLocation(), diag::note_previous_definition)
549 << OldParam->getDefaultArgRange();
550 } else if (OldParamHasDfl) {
551 // Merge the old default argument into the new parameter unless the new
552 // function is a friend declaration in a template class. In the latter
553 // case the default arguments will be inherited when the friend
554 // declaration will be instantiated.
555 if (New->getFriendObjectKind() == Decl::FOK_None ||
556 !New->getLexicalDeclContext()->isDependentContext()) {
557 // It's important to use getInit() here; getDefaultArg()
558 // strips off any top-level ExprWithCleanups.
559 NewParam->setHasInheritedDefaultArg();
560 if (OldParam->hasUnparsedDefaultArg())
561 NewParam->setUnparsedDefaultArg();
562 else if (OldParam->hasUninstantiatedDefaultArg())
563 NewParam->setUninstantiatedDefaultArg(
564 OldParam->getUninstantiatedDefaultArg());
566 NewParam->setDefaultArg(OldParam->getInit());
568 } else if (NewParamHasDfl) {
569 if (New->getDescribedFunctionTemplate()) {
570 // Paragraph 4, quoted above, only applies to non-template functions.
571 Diag(NewParam->getLocation(),
572 diag::err_param_default_argument_template_redecl)
573 << NewParam->getDefaultArgRange();
574 Diag(PrevForDefaultArgs->getLocation(),
575 diag::note_template_prev_declaration)
577 } else if (New->getTemplateSpecializationKind()
578 != TSK_ImplicitInstantiation &&
579 New->getTemplateSpecializationKind() != TSK_Undeclared) {
580 // C++ [temp.expr.spec]p21:
581 // Default function arguments shall not be specified in a declaration
582 // or a definition for one of the following explicit specializations:
583 // - the explicit specialization of a function template;
584 // - the explicit specialization of a member function template;
585 // - the explicit specialization of a member function of a class
586 // template where the class template specialization to which the
587 // member function specialization belongs is implicitly
589 Diag(NewParam->getLocation(), diag::err_template_spec_default_arg)
590 << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
591 << New->getDeclName()
592 << NewParam->getDefaultArgRange();
593 } else if (New->getDeclContext()->isDependentContext()) {
594 // C++ [dcl.fct.default]p6 (DR217):
595 // Default arguments for a member function of a class template shall
596 // be specified on the initial declaration of the member function
597 // within the class template.
599 // Reading the tea leaves a bit in DR217 and its reference to DR205
600 // leads me to the conclusion that one cannot add default function
601 // arguments for an out-of-line definition of a member function of a
604 if (CXXRecordDecl *Record
605 = dyn_cast<CXXRecordDecl>(New->getDeclContext())) {
606 if (Record->getDescribedClassTemplate())
608 else if (isa<ClassTemplatePartialSpecializationDecl>(Record))
614 Diag(NewParam->getLocation(),
615 diag::err_param_default_argument_member_template_redecl)
617 << NewParam->getDefaultArgRange();
622 // DR1344: If a default argument is added outside a class definition and that
623 // default argument makes the function a special member function, the program
624 // is ill-formed. This can only happen for constructors.
625 if (isa<CXXConstructorDecl>(New) &&
626 New->getMinRequiredArguments() < Old->getMinRequiredArguments()) {
627 CXXSpecialMember NewSM = getSpecialMember(cast<CXXMethodDecl>(New)),
628 OldSM = getSpecialMember(cast<CXXMethodDecl>(Old));
629 if (NewSM != OldSM) {
630 ParmVarDecl *NewParam = New->getParamDecl(New->getMinRequiredArguments());
631 assert(NewParam->hasDefaultArg());
632 Diag(NewParam->getLocation(), diag::err_default_arg_makes_ctor_special)
633 << NewParam->getDefaultArgRange() << NewSM;
634 Diag(Old->getLocation(), diag::note_previous_declaration);
638 const FunctionDecl *Def;
639 // C++11 [dcl.constexpr]p1: If any declaration of a function or function
640 // template has a constexpr specifier then all its declarations shall
641 // contain the constexpr specifier.
642 if (New->getConstexprKind() != Old->getConstexprKind()) {
643 Diag(New->getLocation(), diag::err_constexpr_redecl_mismatch)
644 << New << New->getConstexprKind() << Old->getConstexprKind();
645 Diag(Old->getLocation(), diag::note_previous_declaration);
647 } else if (!Old->getMostRecentDecl()->isInlined() && New->isInlined() &&
648 Old->isDefined(Def) &&
649 // If a friend function is inlined but does not have 'inline'
650 // specifier, it is a definition. Do not report attribute conflict
651 // in this case, redefinition will be diagnosed later.
652 (New->isInlineSpecified() ||
653 New->getFriendObjectKind() == Decl::FOK_None)) {
654 // C++11 [dcl.fcn.spec]p4:
655 // If the definition of a function appears in a translation unit before its
656 // first declaration as inline, the program is ill-formed.
657 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
658 Diag(Def->getLocation(), diag::note_previous_definition);
662 // C++17 [temp.deduct.guide]p3:
663 // Two deduction guide declarations in the same translation unit
664 // for the same class template shall not have equivalent
665 // parameter-declaration-clauses.
666 if (isa<CXXDeductionGuideDecl>(New) &&
667 !New->isFunctionTemplateSpecialization()) {
668 Diag(New->getLocation(), diag::err_deduction_guide_redeclared);
669 Diag(Old->getLocation(), diag::note_previous_declaration);
672 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a default
673 // argument expression, that declaration shall be a definition and shall be
674 // the only declaration of the function or function template in the
676 if (Old->getFriendObjectKind() == Decl::FOK_Undeclared &&
677 functionDeclHasDefaultArgument(Old)) {
678 Diag(New->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
679 Diag(Old->getLocation(), diag::note_previous_declaration);
687 Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
688 MultiTemplateParamsArg TemplateParamLists) {
689 assert(D.isDecompositionDeclarator());
690 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
692 // The syntax only allows a decomposition declarator as a simple-declaration,
693 // a for-range-declaration, or a condition in Clang, but we parse it in more
695 if (!D.mayHaveDecompositionDeclarator()) {
696 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
697 << Decomp.getSourceRange();
701 if (!TemplateParamLists.empty()) {
702 // FIXME: There's no rule against this, but there are also no rules that
703 // would actually make it usable, so we reject it for now.
704 Diag(TemplateParamLists.front()->getTemplateLoc(),
705 diag::err_decomp_decl_template);
709 Diag(Decomp.getLSquareLoc(),
710 !getLangOpts().CPlusPlus17
711 ? diag::ext_decomp_decl
712 : D.getContext() == DeclaratorContext::ConditionContext
713 ? diag::ext_decomp_decl_cond
714 : diag::warn_cxx14_compat_decomp_decl)
715 << Decomp.getSourceRange();
717 // The semantic context is always just the current context.
718 DeclContext *const DC = CurContext;
720 // C++17 [dcl.dcl]/8:
721 // The decl-specifier-seq shall contain only the type-specifier auto
722 // and cv-qualifiers.
723 // C++2a [dcl.dcl]/8:
724 // If decl-specifier-seq contains any decl-specifier other than static,
725 // thread_local, auto, or cv-qualifiers, the program is ill-formed.
726 auto &DS = D.getDeclSpec();
728 SmallVector<StringRef, 8> BadSpecifiers;
729 SmallVector<SourceLocation, 8> BadSpecifierLocs;
730 SmallVector<StringRef, 8> CPlusPlus20Specifiers;
731 SmallVector<SourceLocation, 8> CPlusPlus20SpecifierLocs;
732 if (auto SCS = DS.getStorageClassSpec()) {
733 if (SCS == DeclSpec::SCS_static) {
734 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(SCS));
735 CPlusPlus20SpecifierLocs.push_back(DS.getStorageClassSpecLoc());
737 BadSpecifiers.push_back(DeclSpec::getSpecifierName(SCS));
738 BadSpecifierLocs.push_back(DS.getStorageClassSpecLoc());
741 if (auto TSCS = DS.getThreadStorageClassSpec()) {
742 CPlusPlus20Specifiers.push_back(DeclSpec::getSpecifierName(TSCS));
743 CPlusPlus20SpecifierLocs.push_back(DS.getThreadStorageClassSpecLoc());
745 if (DS.hasConstexprSpecifier()) {
746 BadSpecifiers.push_back(
747 DeclSpec::getSpecifierName(DS.getConstexprSpecifier()));
748 BadSpecifierLocs.push_back(DS.getConstexprSpecLoc());
750 if (DS.isInlineSpecified()) {
751 BadSpecifiers.push_back("inline");
752 BadSpecifierLocs.push_back(DS.getInlineSpecLoc());
754 if (!BadSpecifiers.empty()) {
755 auto &&Err = Diag(BadSpecifierLocs.front(), diag::err_decomp_decl_spec);
756 Err << (int)BadSpecifiers.size()
757 << llvm::join(BadSpecifiers.begin(), BadSpecifiers.end(), " ");
758 // Don't add FixItHints to remove the specifiers; we do still respect
759 // them when building the underlying variable.
760 for (auto Loc : BadSpecifierLocs)
761 Err << SourceRange(Loc, Loc);
762 } else if (!CPlusPlus20Specifiers.empty()) {
763 auto &&Warn = Diag(CPlusPlus20SpecifierLocs.front(),
764 getLangOpts().CPlusPlus2a
765 ? diag::warn_cxx17_compat_decomp_decl_spec
766 : diag::ext_decomp_decl_spec);
767 Warn << (int)CPlusPlus20Specifiers.size()
768 << llvm::join(CPlusPlus20Specifiers.begin(),
769 CPlusPlus20Specifiers.end(), " ");
770 for (auto Loc : CPlusPlus20SpecifierLocs)
771 Warn << SourceRange(Loc, Loc);
773 // We can't recover from it being declared as a typedef.
774 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
778 // C++2a [dcl.struct.bind]p1:
779 // A cv that includes volatile is deprecated
780 if ((DS.getTypeQualifiers() & DeclSpec::TQ_volatile) &&
781 getLangOpts().CPlusPlus2a)
782 Diag(DS.getVolatileSpecLoc(),
783 diag::warn_deprecated_volatile_structured_binding);
785 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
786 QualType R = TInfo->getType();
788 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
789 UPPC_DeclarationType))
792 // The syntax only allows a single ref-qualifier prior to the decomposition
793 // declarator. No other declarator chunks are permitted. Also check the type
795 if (DS.getTypeSpecType() != DeclSpec::TST_auto ||
796 D.hasGroupingParens() || D.getNumTypeObjects() > 1 ||
797 (D.getNumTypeObjects() == 1 &&
798 D.getTypeObject(0).Kind != DeclaratorChunk::Reference)) {
799 Diag(Decomp.getLSquareLoc(),
800 (D.hasGroupingParens() ||
801 (D.getNumTypeObjects() &&
802 D.getTypeObject(0).Kind == DeclaratorChunk::Paren))
803 ? diag::err_decomp_decl_parens
804 : diag::err_decomp_decl_type)
807 // In most cases, there's no actual problem with an explicitly-specified
808 // type, but a function type won't work here, and ActOnVariableDeclarator
809 // shouldn't be called for such a type.
810 if (R->isFunctionType())
814 // Build the BindingDecls.
815 SmallVector<BindingDecl*, 8> Bindings;
817 // Build the BindingDecls.
818 for (auto &B : D.getDecompositionDeclarator().bindings()) {
819 // Check for name conflicts.
820 DeclarationNameInfo NameInfo(B.Name, B.NameLoc);
821 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
822 ForVisibleRedeclaration);
823 LookupName(Previous, S,
824 /*CreateBuiltins*/DC->getRedeclContext()->isTranslationUnit());
826 // It's not permitted to shadow a template parameter name.
827 if (Previous.isSingleResult() &&
828 Previous.getFoundDecl()->isTemplateParameter()) {
829 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
830 Previous.getFoundDecl());
834 bool ConsiderLinkage = DC->isFunctionOrMethod() &&
835 DS.getStorageClassSpec() == DeclSpec::SCS_extern;
836 FilterLookupForScope(Previous, DC, S, ConsiderLinkage,
837 /*AllowInlineNamespace*/false);
838 if (!Previous.empty()) {
839 auto *Old = Previous.getRepresentativeDecl();
840 Diag(B.NameLoc, diag::err_redefinition) << B.Name;
841 Diag(Old->getLocation(), diag::note_previous_definition);
844 auto *BD = BindingDecl::Create(Context, DC, B.NameLoc, B.Name);
845 PushOnScopeChains(BD, S, true);
846 Bindings.push_back(BD);
847 ParsingInitForAutoVars.insert(BD);
850 // There are no prior lookup results for the variable itself, because it
852 DeclarationNameInfo NameInfo((IdentifierInfo *)nullptr,
853 Decomp.getLSquareLoc());
854 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
855 ForVisibleRedeclaration);
857 // Build the variable that holds the non-decomposed object.
858 bool AddToScope = true;
860 ActOnVariableDeclarator(S, D, DC, TInfo, Previous,
861 MultiTemplateParamsArg(), AddToScope, Bindings);
864 CurContext->addHiddenDecl(New);
867 if (isInOpenMPDeclareTargetContext())
868 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
873 static bool checkSimpleDecomposition(
874 Sema &S, ArrayRef<BindingDecl *> Bindings, ValueDecl *Src,
875 QualType DecompType, const llvm::APSInt &NumElems, QualType ElemType,
876 llvm::function_ref<ExprResult(SourceLocation, Expr *, unsigned)> GetInit) {
877 if ((int64_t)Bindings.size() != NumElems) {
878 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
879 << DecompType << (unsigned)Bindings.size() << NumElems.toString(10)
880 << (NumElems < Bindings.size());
885 for (auto *B : Bindings) {
886 SourceLocation Loc = B->getLocation();
887 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
890 E = GetInit(Loc, E.get(), I++);
893 B->setBinding(ElemType, E.get());
899 static bool checkArrayLikeDecomposition(Sema &S,
900 ArrayRef<BindingDecl *> Bindings,
901 ValueDecl *Src, QualType DecompType,
902 const llvm::APSInt &NumElems,
904 return checkSimpleDecomposition(
905 S, Bindings, Src, DecompType, NumElems, ElemType,
906 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
907 ExprResult E = S.ActOnIntegerConstant(Loc, I);
910 return S.CreateBuiltinArraySubscriptExpr(Base, Loc, E.get(), Loc);
914 static bool checkArrayDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
915 ValueDecl *Src, QualType DecompType,
916 const ConstantArrayType *CAT) {
917 return checkArrayLikeDecomposition(S, Bindings, Src, DecompType,
918 llvm::APSInt(CAT->getSize()),
919 CAT->getElementType());
922 static bool checkVectorDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
923 ValueDecl *Src, QualType DecompType,
924 const VectorType *VT) {
925 return checkArrayLikeDecomposition(
926 S, Bindings, Src, DecompType, llvm::APSInt::get(VT->getNumElements()),
927 S.Context.getQualifiedType(VT->getElementType(),
928 DecompType.getQualifiers()));
931 static bool checkComplexDecomposition(Sema &S,
932 ArrayRef<BindingDecl *> Bindings,
933 ValueDecl *Src, QualType DecompType,
934 const ComplexType *CT) {
935 return checkSimpleDecomposition(
936 S, Bindings, Src, DecompType, llvm::APSInt::get(2),
937 S.Context.getQualifiedType(CT->getElementType(),
938 DecompType.getQualifiers()),
939 [&](SourceLocation Loc, Expr *Base, unsigned I) -> ExprResult {
940 return S.CreateBuiltinUnaryOp(Loc, I ? UO_Imag : UO_Real, Base);
944 static std::string printTemplateArgs(const PrintingPolicy &PrintingPolicy,
945 TemplateArgumentListInfo &Args) {
947 llvm::raw_svector_ostream OS(SS);
949 for (auto &Arg : Args.arguments()) {
952 Arg.getArgument().print(PrintingPolicy, OS);
958 static bool lookupStdTypeTraitMember(Sema &S, LookupResult &TraitMemberLookup,
959 SourceLocation Loc, StringRef Trait,
960 TemplateArgumentListInfo &Args,
962 auto DiagnoseMissing = [&] {
964 S.Diag(Loc, DiagID) << printTemplateArgs(S.Context.getPrintingPolicy(),
969 // FIXME: Factor out duplication with lookupPromiseType in SemaCoroutine.
970 NamespaceDecl *Std = S.getStdNamespace();
972 return DiagnoseMissing();
974 // Look up the trait itself, within namespace std. We can diagnose various
975 // problems with this lookup even if we've been asked to not diagnose a
976 // missing specialization, because this can only fail if the user has been
977 // declaring their own names in namespace std or we don't support the
978 // standard library implementation in use.
979 LookupResult Result(S, &S.PP.getIdentifierTable().get(Trait),
980 Loc, Sema::LookupOrdinaryName);
981 if (!S.LookupQualifiedName(Result, Std))
982 return DiagnoseMissing();
983 if (Result.isAmbiguous())
986 ClassTemplateDecl *TraitTD = Result.getAsSingle<ClassTemplateDecl>();
988 Result.suppressDiagnostics();
989 NamedDecl *Found = *Result.begin();
990 S.Diag(Loc, diag::err_std_type_trait_not_class_template) << Trait;
991 S.Diag(Found->getLocation(), diag::note_declared_at);
995 // Build the template-id.
996 QualType TraitTy = S.CheckTemplateIdType(TemplateName(TraitTD), Loc, Args);
997 if (TraitTy.isNull())
999 if (!S.isCompleteType(Loc, TraitTy)) {
1001 S.RequireCompleteType(
1002 Loc, TraitTy, DiagID,
1003 printTemplateArgs(S.Context.getPrintingPolicy(), Args));
1007 CXXRecordDecl *RD = TraitTy->getAsCXXRecordDecl();
1008 assert(RD && "specialization of class template is not a class?");
1010 // Look up the member of the trait type.
1011 S.LookupQualifiedName(TraitMemberLookup, RD);
1012 return TraitMemberLookup.isAmbiguous();
1015 static TemplateArgumentLoc
1016 getTrivialIntegralTemplateArgument(Sema &S, SourceLocation Loc, QualType T,
1018 TemplateArgument Arg(S.Context, S.Context.MakeIntValue(I, T), T);
1019 return S.getTrivialTemplateArgumentLoc(Arg, T, Loc);
1022 static TemplateArgumentLoc
1023 getTrivialTypeTemplateArgument(Sema &S, SourceLocation Loc, QualType T) {
1024 return S.getTrivialTemplateArgumentLoc(TemplateArgument(T), QualType(), Loc);
1027 namespace { enum class IsTupleLike { TupleLike, NotTupleLike, Error }; }
1029 static IsTupleLike isTupleLike(Sema &S, SourceLocation Loc, QualType T,
1030 llvm::APSInt &Size) {
1031 EnterExpressionEvaluationContext ContextRAII(
1032 S, Sema::ExpressionEvaluationContext::ConstantEvaluated);
1034 DeclarationName Value = S.PP.getIdentifierInfo("value");
1035 LookupResult R(S, Value, Loc, Sema::LookupOrdinaryName);
1037 // Form template argument list for tuple_size<T>.
1038 TemplateArgumentListInfo Args(Loc, Loc);
1039 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1041 // If there's no tuple_size specialization or the lookup of 'value' is empty,
1042 // it's not tuple-like.
1043 if (lookupStdTypeTraitMember(S, R, Loc, "tuple_size", Args, /*DiagID*/ 0) ||
1045 return IsTupleLike::NotTupleLike;
1047 // If we get this far, we've committed to the tuple interpretation, but
1048 // we can still fail if there actually isn't a usable ::value.
1050 struct ICEDiagnoser : Sema::VerifyICEDiagnoser {
1052 TemplateArgumentListInfo &Args;
1053 ICEDiagnoser(LookupResult &R, TemplateArgumentListInfo &Args)
1054 : R(R), Args(Args) {}
1055 void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) {
1056 S.Diag(Loc, diag::err_decomp_decl_std_tuple_size_not_constant)
1057 << printTemplateArgs(S.Context.getPrintingPolicy(), Args);
1059 } Diagnoser(R, Args);
1062 S.BuildDeclarationNameExpr(CXXScopeSpec(), R, /*NeedsADL*/false);
1064 return IsTupleLike::Error;
1066 E = S.VerifyIntegerConstantExpression(E.get(), &Size, Diagnoser, false);
1068 return IsTupleLike::Error;
1070 return IsTupleLike::TupleLike;
1073 /// \return std::tuple_element<I, T>::type.
1074 static QualType getTupleLikeElementType(Sema &S, SourceLocation Loc,
1075 unsigned I, QualType T) {
1076 // Form template argument list for tuple_element<I, T>.
1077 TemplateArgumentListInfo Args(Loc, Loc);
1079 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1080 Args.addArgument(getTrivialTypeTemplateArgument(S, Loc, T));
1082 DeclarationName TypeDN = S.PP.getIdentifierInfo("type");
1083 LookupResult R(S, TypeDN, Loc, Sema::LookupOrdinaryName);
1084 if (lookupStdTypeTraitMember(
1085 S, R, Loc, "tuple_element", Args,
1086 diag::err_decomp_decl_std_tuple_element_not_specialized))
1089 auto *TD = R.getAsSingle<TypeDecl>();
1091 R.suppressDiagnostics();
1092 S.Diag(Loc, diag::err_decomp_decl_std_tuple_element_not_specialized)
1093 << printTemplateArgs(S.Context.getPrintingPolicy(), Args);
1095 S.Diag(R.getRepresentativeDecl()->getLocation(), diag::note_declared_at);
1099 return S.Context.getTypeDeclType(TD);
1103 struct BindingDiagnosticTrap {
1105 DiagnosticErrorTrap Trap;
1108 BindingDiagnosticTrap(Sema &S, BindingDecl *BD)
1109 : S(S), Trap(S.Diags), BD(BD) {}
1110 ~BindingDiagnosticTrap() {
1111 if (Trap.hasErrorOccurred())
1112 S.Diag(BD->getLocation(), diag::note_in_binding_decl_init) << BD;
1117 static bool checkTupleLikeDecomposition(Sema &S,
1118 ArrayRef<BindingDecl *> Bindings,
1119 VarDecl *Src, QualType DecompType,
1120 const llvm::APSInt &TupleSize) {
1121 if ((int64_t)Bindings.size() != TupleSize) {
1122 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1123 << DecompType << (unsigned)Bindings.size() << TupleSize.toString(10)
1124 << (TupleSize < Bindings.size());
1128 if (Bindings.empty())
1131 DeclarationName GetDN = S.PP.getIdentifierInfo("get");
1134 // The unqualified-id get is looked up in the scope of E by class member
1135 // access lookup ...
1136 LookupResult MemberGet(S, GetDN, Src->getLocation(), Sema::LookupMemberName);
1137 bool UseMemberGet = false;
1138 if (S.isCompleteType(Src->getLocation(), DecompType)) {
1139 if (auto *RD = DecompType->getAsCXXRecordDecl())
1140 S.LookupQualifiedName(MemberGet, RD);
1141 if (MemberGet.isAmbiguous())
1143 // ... and if that finds at least one declaration that is a function
1144 // template whose first template parameter is a non-type parameter ...
1145 for (NamedDecl *D : MemberGet) {
1146 if (FunctionTemplateDecl *FTD =
1147 dyn_cast<FunctionTemplateDecl>(D->getUnderlyingDecl())) {
1148 TemplateParameterList *TPL = FTD->getTemplateParameters();
1149 if (TPL->size() != 0 &&
1150 isa<NonTypeTemplateParmDecl>(TPL->getParam(0))) {
1151 // ... the initializer is e.get<i>().
1152 UseMemberGet = true;
1160 for (auto *B : Bindings) {
1161 BindingDiagnosticTrap Trap(S, B);
1162 SourceLocation Loc = B->getLocation();
1164 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1168 // e is an lvalue if the type of the entity is an lvalue reference and
1169 // an xvalue otherwise
1170 if (!Src->getType()->isLValueReferenceType())
1171 E = ImplicitCastExpr::Create(S.Context, E.get()->getType(), CK_NoOp,
1172 E.get(), nullptr, VK_XValue);
1174 TemplateArgumentListInfo Args(Loc, Loc);
1176 getTrivialIntegralTemplateArgument(S, Loc, S.Context.getSizeType(), I));
1179 // if [lookup of member get] finds at least one declaration, the
1180 // initializer is e.get<i-1>().
1181 E = S.BuildMemberReferenceExpr(E.get(), DecompType, Loc, false,
1182 CXXScopeSpec(), SourceLocation(), nullptr,
1183 MemberGet, &Args, nullptr);
1187 E = S.BuildCallExpr(nullptr, E.get(), Loc, None, Loc);
1189 // Otherwise, the initializer is get<i-1>(e), where get is looked up
1190 // in the associated namespaces.
1191 Expr *Get = UnresolvedLookupExpr::Create(
1192 S.Context, nullptr, NestedNameSpecifierLoc(), SourceLocation(),
1193 DeclarationNameInfo(GetDN, Loc), /*RequiresADL*/true, &Args,
1194 UnresolvedSetIterator(), UnresolvedSetIterator());
1196 Expr *Arg = E.get();
1197 E = S.BuildCallExpr(nullptr, Get, Loc, Arg, Loc);
1201 Expr *Init = E.get();
1203 // Given the type T designated by std::tuple_element<i - 1, E>::type,
1204 QualType T = getTupleLikeElementType(S, Loc, I, DecompType);
1208 // each vi is a variable of type "reference to T" initialized with the
1209 // initializer, where the reference is an lvalue reference if the
1210 // initializer is an lvalue and an rvalue reference otherwise
1212 S.BuildReferenceType(T, E.get()->isLValue(), Loc, B->getDeclName());
1213 if (RefType.isNull())
1215 auto *RefVD = VarDecl::Create(
1216 S.Context, Src->getDeclContext(), Loc, Loc,
1217 B->getDeclName().getAsIdentifierInfo(), RefType,
1218 S.Context.getTrivialTypeSourceInfo(T, Loc), Src->getStorageClass());
1219 RefVD->setLexicalDeclContext(Src->getLexicalDeclContext());
1220 RefVD->setTSCSpec(Src->getTSCSpec());
1221 RefVD->setImplicit();
1222 if (Src->isInlineSpecified())
1223 RefVD->setInlineSpecified();
1224 RefVD->getLexicalDeclContext()->addHiddenDecl(RefVD);
1226 InitializedEntity Entity = InitializedEntity::InitializeBinding(RefVD);
1227 InitializationKind Kind = InitializationKind::CreateCopy(Loc, Loc);
1228 InitializationSequence Seq(S, Entity, Kind, Init);
1229 E = Seq.Perform(S, Entity, Kind, Init);
1232 E = S.ActOnFinishFullExpr(E.get(), Loc, /*DiscardedValue*/ false);
1235 RefVD->setInit(E.get());
1236 if (!E.get()->isValueDependent())
1237 RefVD->checkInitIsICE();
1239 E = S.BuildDeclarationNameExpr(CXXScopeSpec(),
1240 DeclarationNameInfo(B->getDeclName(), Loc),
1245 B->setBinding(T, E.get());
1252 /// Find the base class to decompose in a built-in decomposition of a class type.
1253 /// This base class search is, unfortunately, not quite like any other that we
1254 /// perform anywhere else in C++.
1255 static DeclAccessPair findDecomposableBaseClass(Sema &S, SourceLocation Loc,
1256 const CXXRecordDecl *RD,
1257 CXXCastPath &BasePath) {
1258 auto BaseHasFields = [](const CXXBaseSpecifier *Specifier,
1259 CXXBasePath &Path) {
1260 return Specifier->getType()->getAsCXXRecordDecl()->hasDirectFields();
1263 const CXXRecordDecl *ClassWithFields = nullptr;
1264 AccessSpecifier AS = AS_public;
1265 if (RD->hasDirectFields())
1267 // Otherwise, all of E's non-static data members shall be public direct
1269 ClassWithFields = RD;
1273 Paths.setOrigin(const_cast<CXXRecordDecl*>(RD));
1274 if (!RD->lookupInBases(BaseHasFields, Paths)) {
1275 // If no classes have fields, just decompose RD itself. (This will work
1276 // if and only if zero bindings were provided.)
1277 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(RD), AS_public);
1280 CXXBasePath *BestPath = nullptr;
1281 for (auto &P : Paths) {
1284 else if (!S.Context.hasSameType(P.back().Base->getType(),
1285 BestPath->back().Base->getType())) {
1287 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1288 << false << RD << BestPath->back().Base->getType()
1289 << P.back().Base->getType();
1290 return DeclAccessPair();
1291 } else if (P.Access < BestPath->Access) {
1296 // ... unambiguous ...
1297 QualType BaseType = BestPath->back().Base->getType();
1298 if (Paths.isAmbiguous(S.Context.getCanonicalType(BaseType))) {
1299 S.Diag(Loc, diag::err_decomp_decl_ambiguous_base)
1300 << RD << BaseType << S.getAmbiguousPathsDisplayString(Paths);
1301 return DeclAccessPair();
1304 // ... [accessible, implied by other rules] base class of E.
1305 S.CheckBaseClassAccess(Loc, BaseType, S.Context.getRecordType(RD),
1306 *BestPath, diag::err_decomp_decl_inaccessible_base);
1307 AS = BestPath->Access;
1309 ClassWithFields = BaseType->getAsCXXRecordDecl();
1310 S.BuildBasePathArray(Paths, BasePath);
1313 // The above search did not check whether the selected class itself has base
1314 // classes with fields, so check that now.
1316 if (ClassWithFields->lookupInBases(BaseHasFields, Paths)) {
1317 S.Diag(Loc, diag::err_decomp_decl_multiple_bases_with_members)
1318 << (ClassWithFields == RD) << RD << ClassWithFields
1319 << Paths.front().back().Base->getType();
1320 return DeclAccessPair();
1323 return DeclAccessPair::make(const_cast<CXXRecordDecl*>(ClassWithFields), AS);
1326 static bool checkMemberDecomposition(Sema &S, ArrayRef<BindingDecl*> Bindings,
1327 ValueDecl *Src, QualType DecompType,
1328 const CXXRecordDecl *OrigRD) {
1329 if (S.RequireCompleteType(Src->getLocation(), DecompType,
1330 diag::err_incomplete_type))
1333 CXXCastPath BasePath;
1334 DeclAccessPair BasePair =
1335 findDecomposableBaseClass(S, Src->getLocation(), OrigRD, BasePath);
1336 const CXXRecordDecl *RD = cast_or_null<CXXRecordDecl>(BasePair.getDecl());
1339 QualType BaseType = S.Context.getQualifiedType(S.Context.getRecordType(RD),
1340 DecompType.getQualifiers());
1342 auto DiagnoseBadNumberOfBindings = [&]() -> bool {
1343 unsigned NumFields =
1344 std::count_if(RD->field_begin(), RD->field_end(),
1345 [](FieldDecl *FD) { return !FD->isUnnamedBitfield(); });
1346 assert(Bindings.size() != NumFields);
1347 S.Diag(Src->getLocation(), diag::err_decomp_decl_wrong_number_bindings)
1348 << DecompType << (unsigned)Bindings.size() << NumFields
1349 << (NumFields < Bindings.size());
1353 // all of E's non-static data members shall be [...] well-formed
1354 // when named as e.name in the context of the structured binding,
1355 // E shall not have an anonymous union member, ...
1357 for (auto *FD : RD->fields()) {
1358 if (FD->isUnnamedBitfield())
1361 if (FD->isAnonymousStructOrUnion()) {
1362 S.Diag(Src->getLocation(), diag::err_decomp_decl_anon_union_member)
1363 << DecompType << FD->getType()->isUnionType();
1364 S.Diag(FD->getLocation(), diag::note_declared_at);
1368 // We have a real field to bind.
1369 if (I >= Bindings.size())
1370 return DiagnoseBadNumberOfBindings();
1371 auto *B = Bindings[I++];
1372 SourceLocation Loc = B->getLocation();
1374 // The field must be accessible in the context of the structured binding.
1375 // We already checked that the base class is accessible.
1376 // FIXME: Add 'const' to AccessedEntity's classes so we can remove the
1378 S.CheckStructuredBindingMemberAccess(
1379 Loc, const_cast<CXXRecordDecl *>(OrigRD),
1380 DeclAccessPair::make(FD, CXXRecordDecl::MergeAccess(
1381 BasePair.getAccess(), FD->getAccess())));
1383 // Initialize the binding to Src.FD.
1384 ExprResult E = S.BuildDeclRefExpr(Src, DecompType, VK_LValue, Loc);
1387 E = S.ImpCastExprToType(E.get(), BaseType, CK_UncheckedDerivedToBase,
1388 VK_LValue, &BasePath);
1391 E = S.BuildFieldReferenceExpr(E.get(), /*IsArrow*/ false, Loc,
1393 DeclAccessPair::make(FD, FD->getAccess()),
1394 DeclarationNameInfo(FD->getDeclName(), Loc));
1398 // If the type of the member is T, the referenced type is cv T, where cv is
1399 // the cv-qualification of the decomposition expression.
1401 // FIXME: We resolve a defect here: if the field is mutable, we do not add
1402 // 'const' to the type of the field.
1403 Qualifiers Q = DecompType.getQualifiers();
1404 if (FD->isMutable())
1406 B->setBinding(S.BuildQualifiedType(FD->getType(), Loc, Q), E.get());
1409 if (I != Bindings.size())
1410 return DiagnoseBadNumberOfBindings();
1415 void Sema::CheckCompleteDecompositionDeclaration(DecompositionDecl *DD) {
1416 QualType DecompType = DD->getType();
1418 // If the type of the decomposition is dependent, then so is the type of
1420 if (DecompType->isDependentType()) {
1421 for (auto *B : DD->bindings())
1422 B->setType(Context.DependentTy);
1426 DecompType = DecompType.getNonReferenceType();
1427 ArrayRef<BindingDecl*> Bindings = DD->bindings();
1429 // C++1z [dcl.decomp]/2:
1430 // If E is an array type [...]
1431 // As an extension, we also support decomposition of built-in complex and
1433 if (auto *CAT = Context.getAsConstantArrayType(DecompType)) {
1434 if (checkArrayDecomposition(*this, Bindings, DD, DecompType, CAT))
1435 DD->setInvalidDecl();
1438 if (auto *VT = DecompType->getAs<VectorType>()) {
1439 if (checkVectorDecomposition(*this, Bindings, DD, DecompType, VT))
1440 DD->setInvalidDecl();
1443 if (auto *CT = DecompType->getAs<ComplexType>()) {
1444 if (checkComplexDecomposition(*this, Bindings, DD, DecompType, CT))
1445 DD->setInvalidDecl();
1449 // C++1z [dcl.decomp]/3:
1450 // if the expression std::tuple_size<E>::value is a well-formed integral
1451 // constant expression, [...]
1452 llvm::APSInt TupleSize(32);
1453 switch (isTupleLike(*this, DD->getLocation(), DecompType, TupleSize)) {
1454 case IsTupleLike::Error:
1455 DD->setInvalidDecl();
1458 case IsTupleLike::TupleLike:
1459 if (checkTupleLikeDecomposition(*this, Bindings, DD, DecompType, TupleSize))
1460 DD->setInvalidDecl();
1463 case IsTupleLike::NotTupleLike:
1467 // C++1z [dcl.dcl]/8:
1468 // [E shall be of array or non-union class type]
1469 CXXRecordDecl *RD = DecompType->getAsCXXRecordDecl();
1470 if (!RD || RD->isUnion()) {
1471 Diag(DD->getLocation(), diag::err_decomp_decl_unbindable_type)
1472 << DD << !RD << DecompType;
1473 DD->setInvalidDecl();
1477 // C++1z [dcl.decomp]/4:
1478 // all of E's non-static data members shall be [...] direct members of
1479 // E or of the same unambiguous public base class of E, ...
1480 if (checkMemberDecomposition(*this, Bindings, DD, DecompType, RD))
1481 DD->setInvalidDecl();
1484 /// Merge the exception specifications of two variable declarations.
1486 /// This is called when there's a redeclaration of a VarDecl. The function
1487 /// checks if the redeclaration might have an exception specification and
1488 /// validates compatibility and merges the specs if necessary.
1489 void Sema::MergeVarDeclExceptionSpecs(VarDecl *New, VarDecl *Old) {
1490 // Shortcut if exceptions are disabled.
1491 if (!getLangOpts().CXXExceptions)
1494 assert(Context.hasSameType(New->getType(), Old->getType()) &&
1495 "Should only be called if types are otherwise the same.");
1497 QualType NewType = New->getType();
1498 QualType OldType = Old->getType();
1500 // We're only interested in pointers and references to functions, as well
1501 // as pointers to member functions.
1502 if (const ReferenceType *R = NewType->getAs<ReferenceType>()) {
1503 NewType = R->getPointeeType();
1504 OldType = OldType->castAs<ReferenceType>()->getPointeeType();
1505 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1506 NewType = P->getPointeeType();
1507 OldType = OldType->castAs<PointerType>()->getPointeeType();
1508 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1509 NewType = M->getPointeeType();
1510 OldType = OldType->castAs<MemberPointerType>()->getPointeeType();
1513 if (!NewType->isFunctionProtoType())
1516 // There's lots of special cases for functions. For function pointers, system
1517 // libraries are hopefully not as broken so that we don't need these
1519 if (CheckEquivalentExceptionSpec(
1520 OldType->getAs<FunctionProtoType>(), Old->getLocation(),
1521 NewType->getAs<FunctionProtoType>(), New->getLocation())) {
1522 New->setInvalidDecl();
1526 /// CheckCXXDefaultArguments - Verify that the default arguments for a
1527 /// function declaration are well-formed according to C++
1528 /// [dcl.fct.default].
1529 void Sema::CheckCXXDefaultArguments(FunctionDecl *FD) {
1530 unsigned NumParams = FD->getNumParams();
1533 // Find first parameter with a default argument
1534 for (p = 0; p < NumParams; ++p) {
1535 ParmVarDecl *Param = FD->getParamDecl(p);
1536 if (Param->hasDefaultArg())
1540 // C++11 [dcl.fct.default]p4:
1541 // In a given function declaration, each parameter subsequent to a parameter
1542 // with a default argument shall have a default argument supplied in this or
1543 // a previous declaration or shall be a function parameter pack. A default
1544 // argument shall not be redefined by a later declaration (not even to the
1546 unsigned LastMissingDefaultArg = 0;
1547 for (; p < NumParams; ++p) {
1548 ParmVarDecl *Param = FD->getParamDecl(p);
1549 if (!Param->hasDefaultArg() && !Param->isParameterPack()) {
1550 if (Param->isInvalidDecl())
1551 /* We already complained about this parameter. */;
1552 else if (Param->getIdentifier())
1553 Diag(Param->getLocation(),
1554 diag::err_param_default_argument_missing_name)
1555 << Param->getIdentifier();
1557 Diag(Param->getLocation(),
1558 diag::err_param_default_argument_missing);
1560 LastMissingDefaultArg = p;
1564 if (LastMissingDefaultArg > 0) {
1565 // Some default arguments were missing. Clear out all of the
1566 // default arguments up to (and including) the last missing
1567 // default argument, so that we leave the function parameters
1568 // in a semantically valid state.
1569 for (p = 0; p <= LastMissingDefaultArg; ++p) {
1570 ParmVarDecl *Param = FD->getParamDecl(p);
1571 if (Param->hasDefaultArg()) {
1572 Param->setDefaultArg(nullptr);
1578 /// Check that the given type is a literal type. Issue a diagnostic if not,
1579 /// if Kind is Diagnose.
1580 /// \return \c true if a problem has been found (and optionally diagnosed).
1581 template <typename... Ts>
1582 static bool CheckLiteralType(Sema &SemaRef, Sema::CheckConstexprKind Kind,
1583 SourceLocation Loc, QualType T, unsigned DiagID,
1585 if (T->isDependentType())
1589 case Sema::CheckConstexprKind::Diagnose:
1590 return SemaRef.RequireLiteralType(Loc, T, DiagID,
1591 std::forward<Ts>(DiagArgs)...);
1593 case Sema::CheckConstexprKind::CheckValid:
1594 return !T->isLiteralType(SemaRef.Context);
1597 llvm_unreachable("unknown CheckConstexprKind");
1600 /// Determine whether a destructor cannot be constexpr due to
1601 static bool CheckConstexprDestructorSubobjects(Sema &SemaRef,
1602 const CXXDestructorDecl *DD,
1603 Sema::CheckConstexprKind Kind) {
1604 auto Check = [&](SourceLocation Loc, QualType T, const FieldDecl *FD) {
1605 const CXXRecordDecl *RD =
1606 T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl();
1607 if (!RD || RD->hasConstexprDestructor())
1610 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1611 SemaRef.Diag(DD->getLocation(), diag::err_constexpr_dtor_subobject)
1612 << DD->getConstexprKind() << !FD
1613 << (FD ? FD->getDeclName() : DeclarationName()) << T;
1614 SemaRef.Diag(Loc, diag::note_constexpr_dtor_subobject)
1615 << !FD << (FD ? FD->getDeclName() : DeclarationName()) << T;
1620 const CXXRecordDecl *RD = DD->getParent();
1621 for (const CXXBaseSpecifier &B : RD->bases())
1622 if (!Check(B.getBaseTypeLoc(), B.getType(), nullptr))
1624 for (const FieldDecl *FD : RD->fields())
1625 if (!Check(FD->getLocation(), FD->getType(), FD))
1630 /// Check whether a function's parameter types are all literal types. If so,
1631 /// return true. If not, produce a suitable diagnostic and return false.
1632 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1633 const FunctionDecl *FD,
1634 Sema::CheckConstexprKind Kind) {
1635 unsigned ArgIndex = 0;
1636 const auto *FT = FD->getType()->castAs<FunctionProtoType>();
1637 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1638 e = FT->param_type_end();
1639 i != e; ++i, ++ArgIndex) {
1640 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1641 SourceLocation ParamLoc = PD->getLocation();
1642 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1643 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1644 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1651 /// Check whether a function's return type is a literal type. If so, return
1652 /// true. If not, produce a suitable diagnostic and return false.
1653 static bool CheckConstexprReturnType(Sema &SemaRef, const FunctionDecl *FD,
1654 Sema::CheckConstexprKind Kind) {
1655 if (CheckLiteralType(SemaRef, Kind, FD->getLocation(), FD->getReturnType(),
1656 diag::err_constexpr_non_literal_return,
1662 /// Get diagnostic %select index for tag kind for
1663 /// record diagnostic message.
1664 /// WARNING: Indexes apply to particular diagnostics only!
1666 /// \returns diagnostic %select index.
1667 static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1669 case TTK_Struct: return 0;
1670 case TTK_Interface: return 1;
1671 case TTK_Class: return 2;
1672 default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1676 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1678 Sema::CheckConstexprKind Kind);
1680 // Check whether a function declaration satisfies the requirements of a
1681 // constexpr function definition or a constexpr constructor definition. If so,
1682 // return true. If not, produce appropriate diagnostics (unless asked not to by
1683 // Kind) and return false.
1685 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1686 bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1687 CheckConstexprKind Kind) {
1688 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1689 if (MD && MD->isInstance()) {
1690 // C++11 [dcl.constexpr]p4:
1691 // The definition of a constexpr constructor shall satisfy the following
1693 // - the class shall not have any virtual base classes;
1695 // FIXME: This only applies to constructors and destructors, not arbitrary
1696 // member functions.
1697 const CXXRecordDecl *RD = MD->getParent();
1698 if (RD->getNumVBases()) {
1699 if (Kind == CheckConstexprKind::CheckValid)
1702 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1703 << isa<CXXConstructorDecl>(NewFD)
1704 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1705 for (const auto &I : RD->vbases())
1706 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1707 << I.getSourceRange();
1712 if (!isa<CXXConstructorDecl>(NewFD)) {
1713 // C++11 [dcl.constexpr]p3:
1714 // The definition of a constexpr function shall satisfy the following
1716 // - it shall not be virtual; (removed in C++20)
1717 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1718 if (Method && Method->isVirtual()) {
1719 if (getLangOpts().CPlusPlus2a) {
1720 if (Kind == CheckConstexprKind::Diagnose)
1721 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1723 if (Kind == CheckConstexprKind::CheckValid)
1726 Method = Method->getCanonicalDecl();
1727 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1729 // If it's not obvious why this function is virtual, find an overridden
1730 // function which uses the 'virtual' keyword.
1731 const CXXMethodDecl *WrittenVirtual = Method;
1732 while (!WrittenVirtual->isVirtualAsWritten())
1733 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1734 if (WrittenVirtual != Method)
1735 Diag(WrittenVirtual->getLocation(),
1736 diag::note_overridden_virtual_function);
1741 // - its return type shall be a literal type;
1742 if (!CheckConstexprReturnType(*this, NewFD, Kind))
1746 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1747 // A destructor can be constexpr only if the defaulted destructor could be;
1748 // we don't need to check the members and bases if we already know they all
1749 // have constexpr destructors.
1750 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1751 if (Kind == CheckConstexprKind::CheckValid)
1753 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1758 // - each of its parameter types shall be a literal type;
1759 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1762 Stmt *Body = NewFD->getBody();
1764 "CheckConstexprFunctionDefinition called on function with no body");
1765 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1768 /// Check the given declaration statement is legal within a constexpr function
1769 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1771 /// \return true if the body is OK (maybe only as an extension), false if we
1772 /// have diagnosed a problem.
1773 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1774 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1775 Sema::CheckConstexprKind Kind) {
1776 // C++11 [dcl.constexpr]p3 and p4:
1777 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1779 for (const auto *DclIt : DS->decls()) {
1780 switch (DclIt->getKind()) {
1781 case Decl::StaticAssert:
1783 case Decl::UsingShadow:
1784 case Decl::UsingDirective:
1785 case Decl::UnresolvedUsingTypename:
1786 case Decl::UnresolvedUsingValue:
1787 // - static_assert-declarations
1788 // - using-declarations,
1789 // - using-directives,
1793 case Decl::TypeAlias: {
1794 // - typedef declarations and alias-declarations that do not define
1795 // classes or enumerations,
1796 const auto *TN = cast<TypedefNameDecl>(DclIt);
1797 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1798 // Don't allow variably-modified types in constexpr functions.
1799 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1800 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1801 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1802 << TL.getSourceRange() << TL.getType()
1803 << isa<CXXConstructorDecl>(Dcl);
1811 case Decl::CXXRecord:
1812 // C++1y allows types to be defined, not just declared.
1813 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1814 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1815 SemaRef.Diag(DS->getBeginLoc(),
1816 SemaRef.getLangOpts().CPlusPlus14
1817 ? diag::warn_cxx11_compat_constexpr_type_definition
1818 : diag::ext_constexpr_type_definition)
1819 << isa<CXXConstructorDecl>(Dcl);
1820 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1826 case Decl::EnumConstant:
1827 case Decl::IndirectField:
1829 // These can only appear with other declarations which are banned in
1830 // C++11 and permitted in C++1y, so ignore them.
1834 case Decl::Decomposition: {
1835 // C++1y [dcl.constexpr]p3 allows anything except:
1836 // a definition of a variable of non-literal type or of static or
1837 // thread storage duration or [before C++2a] for which no
1838 // initialization is performed.
1839 const auto *VD = cast<VarDecl>(DclIt);
1840 if (VD->isThisDeclarationADefinition()) {
1841 if (VD->isStaticLocal()) {
1842 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1843 SemaRef.Diag(VD->getLocation(),
1844 diag::err_constexpr_local_var_static)
1845 << isa<CXXConstructorDecl>(Dcl)
1846 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1850 if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1851 diag::err_constexpr_local_var_non_literal_type,
1852 isa<CXXConstructorDecl>(Dcl)))
1854 if (!VD->getType()->isDependentType() &&
1855 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1856 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1859 SemaRef.getLangOpts().CPlusPlus2a
1860 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1861 : diag::ext_constexpr_local_var_no_init)
1862 << isa<CXXConstructorDecl>(Dcl);
1863 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
1869 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1870 SemaRef.Diag(VD->getLocation(),
1871 SemaRef.getLangOpts().CPlusPlus14
1872 ? diag::warn_cxx11_compat_constexpr_local_var
1873 : diag::ext_constexpr_local_var)
1874 << isa<CXXConstructorDecl>(Dcl);
1875 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1881 case Decl::NamespaceAlias:
1882 case Decl::Function:
1883 // These are disallowed in C++11 and permitted in C++1y. Allow them
1884 // everywhere as an extension.
1885 if (!Cxx1yLoc.isValid())
1886 Cxx1yLoc = DS->getBeginLoc();
1890 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1891 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1892 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1901 /// Check that the given field is initialized within a constexpr constructor.
1903 /// \param Dcl The constexpr constructor being checked.
1904 /// \param Field The field being checked. This may be a member of an anonymous
1905 /// struct or union nested within the class being checked.
1906 /// \param Inits All declarations, including anonymous struct/union members and
1907 /// indirect members, for which any initialization was provided.
1908 /// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1909 /// multiple notes for different members to the same error.
1910 /// \param Kind Whether we're diagnosing a constructor as written or determining
1911 /// whether the formal requirements are satisfied.
1912 /// \return \c false if we're checking for validity and the constructor does
1913 /// not satisfy the requirements on a constexpr constructor.
1914 static bool CheckConstexprCtorInitializer(Sema &SemaRef,
1915 const FunctionDecl *Dcl,
1917 llvm::SmallSet<Decl*, 16> &Inits,
1919 Sema::CheckConstexprKind Kind) {
1920 // In C++20 onwards, there's nothing to check for validity.
1921 if (Kind == Sema::CheckConstexprKind::CheckValid &&
1922 SemaRef.getLangOpts().CPlusPlus2a)
1925 if (Field->isInvalidDecl())
1928 if (Field->isUnnamedBitfield())
1931 // Anonymous unions with no variant members and empty anonymous structs do not
1932 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1933 // indirect fields don't need initializing.
1934 if (Field->isAnonymousStructOrUnion() &&
1935 (Field->getType()->isUnionType()
1936 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1937 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1940 if (!Inits.count(Field)) {
1941 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1943 SemaRef.Diag(Dcl->getLocation(),
1944 SemaRef.getLangOpts().CPlusPlus2a
1945 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
1946 : diag::ext_constexpr_ctor_missing_init);
1949 SemaRef.Diag(Field->getLocation(),
1950 diag::note_constexpr_ctor_missing_init);
1951 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
1954 } else if (Field->isAnonymousStructOrUnion()) {
1955 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1956 for (auto *I : RD->fields())
1957 // If an anonymous union contains an anonymous struct of which any member
1958 // is initialized, all members must be initialized.
1959 if (!RD->isUnion() || Inits.count(I))
1960 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
1967 /// Check the provided statement is allowed in a constexpr function
1970 CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
1971 SmallVectorImpl<SourceLocation> &ReturnStmts,
1972 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
1973 Sema::CheckConstexprKind Kind) {
1974 // - its function-body shall be [...] a compound-statement that contains only
1975 switch (S->getStmtClass()) {
1976 case Stmt::NullStmtClass:
1977 // - null statements,
1980 case Stmt::DeclStmtClass:
1981 // - static_assert-declarations
1982 // - using-declarations,
1983 // - using-directives,
1984 // - typedef declarations and alias-declarations that do not define
1985 // classes or enumerations,
1986 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
1990 case Stmt::ReturnStmtClass:
1991 // - and exactly one return statement;
1992 if (isa<CXXConstructorDecl>(Dcl)) {
1993 // C++1y allows return statements in constexpr constructors.
1994 if (!Cxx1yLoc.isValid())
1995 Cxx1yLoc = S->getBeginLoc();
1999 ReturnStmts.push_back(S->getBeginLoc());
2002 case Stmt::CompoundStmtClass: {
2003 // C++1y allows compound-statements.
2004 if (!Cxx1yLoc.isValid())
2005 Cxx1yLoc = S->getBeginLoc();
2007 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2008 for (auto *BodyIt : CompStmt->body()) {
2009 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2010 Cxx1yLoc, Cxx2aLoc, Kind))
2016 case Stmt::AttributedStmtClass:
2017 if (!Cxx1yLoc.isValid())
2018 Cxx1yLoc = S->getBeginLoc();
2021 case Stmt::IfStmtClass: {
2022 // C++1y allows if-statements.
2023 if (!Cxx1yLoc.isValid())
2024 Cxx1yLoc = S->getBeginLoc();
2026 IfStmt *If = cast<IfStmt>(S);
2027 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2028 Cxx1yLoc, Cxx2aLoc, Kind))
2030 if (If->getElse() &&
2031 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2032 Cxx1yLoc, Cxx2aLoc, Kind))
2037 case Stmt::WhileStmtClass:
2038 case Stmt::DoStmtClass:
2039 case Stmt::ForStmtClass:
2040 case Stmt::CXXForRangeStmtClass:
2041 case Stmt::ContinueStmtClass:
2042 // C++1y allows all of these. We don't allow them as extensions in C++11,
2043 // because they don't make sense without variable mutation.
2044 if (!SemaRef.getLangOpts().CPlusPlus14)
2046 if (!Cxx1yLoc.isValid())
2047 Cxx1yLoc = S->getBeginLoc();
2048 for (Stmt *SubStmt : S->children())
2050 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2051 Cxx1yLoc, Cxx2aLoc, Kind))
2055 case Stmt::SwitchStmtClass:
2056 case Stmt::CaseStmtClass:
2057 case Stmt::DefaultStmtClass:
2058 case Stmt::BreakStmtClass:
2059 // C++1y allows switch-statements, and since they don't need variable
2060 // mutation, we can reasonably allow them in C++11 as an extension.
2061 if (!Cxx1yLoc.isValid())
2062 Cxx1yLoc = S->getBeginLoc();
2063 for (Stmt *SubStmt : S->children())
2065 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2066 Cxx1yLoc, Cxx2aLoc, Kind))
2070 case Stmt::GCCAsmStmtClass:
2071 case Stmt::MSAsmStmtClass:
2072 // C++2a allows inline assembly statements.
2073 case Stmt::CXXTryStmtClass:
2074 if (Cxx2aLoc.isInvalid())
2075 Cxx2aLoc = S->getBeginLoc();
2076 for (Stmt *SubStmt : S->children()) {
2078 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2079 Cxx1yLoc, Cxx2aLoc, Kind))
2084 case Stmt::CXXCatchStmtClass:
2085 // Do not bother checking the language mode (already covered by the
2086 // try block check).
2087 if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
2088 cast<CXXCatchStmt>(S)->getHandlerBlock(),
2089 ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
2097 // C++1y allows expression-statements.
2098 if (!Cxx1yLoc.isValid())
2099 Cxx1yLoc = S->getBeginLoc();
2103 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2104 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2105 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2110 /// Check the body for the given constexpr function declaration only contains
2111 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2113 /// \return true if the body is OK, false if we have found or diagnosed a
2115 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2117 Sema::CheckConstexprKind Kind) {
2118 SmallVector<SourceLocation, 4> ReturnStmts;
2120 if (isa<CXXTryStmt>(Body)) {
2121 // C++11 [dcl.constexpr]p3:
2122 // The definition of a constexpr function shall satisfy the following
2123 // constraints: [...]
2124 // - its function-body shall be = delete, = default, or a
2125 // compound-statement
2127 // C++11 [dcl.constexpr]p4:
2128 // In the definition of a constexpr constructor, [...]
2129 // - its function-body shall not be a function-try-block;
2131 // This restriction is lifted in C++2a, as long as inner statements also
2132 // apply the general constexpr rules.
2134 case Sema::CheckConstexprKind::CheckValid:
2135 if (!SemaRef.getLangOpts().CPlusPlus2a)
2139 case Sema::CheckConstexprKind::Diagnose:
2140 SemaRef.Diag(Body->getBeginLoc(),
2141 !SemaRef.getLangOpts().CPlusPlus2a
2142 ? diag::ext_constexpr_function_try_block_cxx2a
2143 : diag::warn_cxx17_compat_constexpr_function_try_block)
2144 << isa<CXXConstructorDecl>(Dcl);
2149 // - its function-body shall be [...] a compound-statement that contains only
2150 // [... list of cases ...]
2152 // Note that walking the children here is enough to properly check for
2153 // CompoundStmt and CXXTryStmt body.
2154 SourceLocation Cxx1yLoc, Cxx2aLoc;
2155 for (Stmt *SubStmt : Body->children()) {
2157 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2158 Cxx1yLoc, Cxx2aLoc, Kind))
2162 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2163 // If this is only valid as an extension, report that we don't satisfy the
2164 // constraints of the current language.
2165 if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus2a) ||
2166 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2168 } else if (Cxx2aLoc.isValid()) {
2169 SemaRef.Diag(Cxx2aLoc,
2170 SemaRef.getLangOpts().CPlusPlus2a
2171 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2172 : diag::ext_constexpr_body_invalid_stmt_cxx2a)
2173 << isa<CXXConstructorDecl>(Dcl);
2174 } else if (Cxx1yLoc.isValid()) {
2175 SemaRef.Diag(Cxx1yLoc,
2176 SemaRef.getLangOpts().CPlusPlus14
2177 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2178 : diag::ext_constexpr_body_invalid_stmt)
2179 << isa<CXXConstructorDecl>(Dcl);
2182 if (const CXXConstructorDecl *Constructor
2183 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2184 const CXXRecordDecl *RD = Constructor->getParent();
2186 // - every non-variant non-static data member and base class sub-object
2187 // shall be initialized;
2189 // - if the class is a union having variant members, exactly one of them
2190 // shall be initialized;
2191 if (RD->isUnion()) {
2192 if (Constructor->getNumCtorInitializers() == 0 &&
2193 RD->hasVariantMembers()) {
2194 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2197 SemaRef.getLangOpts().CPlusPlus2a
2198 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2199 : diag::ext_constexpr_union_ctor_no_init);
2200 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
2204 } else if (!Constructor->isDependentContext() &&
2205 !Constructor->isDelegatingConstructor()) {
2206 assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
2208 // Skip detailed checking if we have enough initializers, and we would
2209 // allow at most one initializer per member.
2210 bool AnyAnonStructUnionMembers = false;
2211 unsigned Fields = 0;
2212 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2213 E = RD->field_end(); I != E; ++I, ++Fields) {
2214 if (I->isAnonymousStructOrUnion()) {
2215 AnyAnonStructUnionMembers = true;
2220 // - if the class is a union-like class, but is not a union, for each of
2221 // its anonymous union members having variant members, exactly one of
2222 // them shall be initialized;
2223 if (AnyAnonStructUnionMembers ||
2224 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2225 // Check initialization of non-static data members. Base classes are
2226 // always initialized so do not need to be checked. Dependent bases
2227 // might not have initializers in the member initializer list.
2228 llvm::SmallSet<Decl*, 16> Inits;
2229 for (const auto *I: Constructor->inits()) {
2230 if (FieldDecl *FD = I->getMember())
2232 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2233 Inits.insert(ID->chain_begin(), ID->chain_end());
2236 bool Diagnosed = false;
2237 for (auto *I : RD->fields())
2238 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2244 if (ReturnStmts.empty()) {
2245 // C++1y doesn't require constexpr functions to contain a 'return'
2246 // statement. We still do, unless the return type might be void, because
2247 // otherwise if there's no return statement, the function cannot
2248 // be used in a core constant expression.
2249 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2250 (Dcl->getReturnType()->isVoidType() ||
2251 Dcl->getReturnType()->isDependentType());
2253 case Sema::CheckConstexprKind::Diagnose:
2254 SemaRef.Diag(Dcl->getLocation(),
2255 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2256 : diag::err_constexpr_body_no_return)
2257 << Dcl->isConsteval();
2262 case Sema::CheckConstexprKind::CheckValid:
2263 // The formal requirements don't include this rule in C++14, even
2264 // though the "must be able to produce a constant expression" rules
2265 // still imply it in some cases.
2266 if (!SemaRef.getLangOpts().CPlusPlus14)
2270 } else if (ReturnStmts.size() > 1) {
2272 case Sema::CheckConstexprKind::Diagnose:
2275 SemaRef.getLangOpts().CPlusPlus14
2276 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2277 : diag::ext_constexpr_body_multiple_return);
2278 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2279 SemaRef.Diag(ReturnStmts[I],
2280 diag::note_constexpr_body_previous_return);
2283 case Sema::CheckConstexprKind::CheckValid:
2284 if (!SemaRef.getLangOpts().CPlusPlus14)
2291 // C++11 [dcl.constexpr]p5:
2292 // if no function argument values exist such that the function invocation
2293 // substitution would produce a constant expression, the program is
2294 // ill-formed; no diagnostic required.
2295 // C++11 [dcl.constexpr]p3:
2296 // - every constructor call and implicit conversion used in initializing the
2297 // return value shall be one of those allowed in a constant expression.
2298 // C++11 [dcl.constexpr]p4:
2299 // - every constructor involved in initializing non-static data members and
2300 // base class sub-objects shall be a constexpr constructor.
2302 // Note that this rule is distinct from the "requirements for a constexpr
2303 // function", so is not checked in CheckValid mode.
2304 SmallVector<PartialDiagnosticAt, 8> Diags;
2305 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2306 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2307 SemaRef.Diag(Dcl->getLocation(),
2308 diag::ext_constexpr_function_never_constant_expr)
2309 << isa<CXXConstructorDecl>(Dcl);
2310 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2311 SemaRef.Diag(Diags[I].first, Diags[I].second);
2312 // Don't return false here: we allow this for compatibility in
2319 /// Get the class that is directly named by the current context. This is the
2320 /// class for which an unqualified-id in this scope could name a constructor
2323 /// If the scope specifier denotes a class, this will be that class.
2324 /// If the scope specifier is empty, this will be the class whose
2325 /// member-specification we are currently within. Otherwise, there
2326 /// is no such class.
2327 CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2328 assert(getLangOpts().CPlusPlus && "No class names in C!");
2330 if (SS && SS->isInvalid())
2333 if (SS && SS->isNotEmpty()) {
2334 DeclContext *DC = computeDeclContext(*SS, true);
2335 return dyn_cast_or_null<CXXRecordDecl>(DC);
2338 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2341 /// isCurrentClassName - Determine whether the identifier II is the
2342 /// name of the class type currently being defined. In the case of
2343 /// nested classes, this will only return true if II is the name of
2344 /// the innermost class.
2345 bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2346 const CXXScopeSpec *SS) {
2347 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2348 return CurDecl && &II == CurDecl->getIdentifier();
2351 /// Determine whether the identifier II is a typo for the name of
2352 /// the class type currently being defined. If so, update it to the identifier
2353 /// that should have been used.
2354 bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2355 assert(getLangOpts().CPlusPlus && "No class names in C!");
2357 if (!getLangOpts().SpellChecking)
2360 CXXRecordDecl *CurDecl;
2361 if (SS && SS->isSet() && !SS->isInvalid()) {
2362 DeclContext *DC = computeDeclContext(*SS, true);
2363 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2365 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2367 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2368 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2369 < II->getLength()) {
2370 II = CurDecl->getIdentifier();
2377 /// Determine whether the given class is a base class of the given
2378 /// class, including looking at dependent bases.
2379 static bool findCircularInheritance(const CXXRecordDecl *Class,
2380 const CXXRecordDecl *Current) {
2381 SmallVector<const CXXRecordDecl*, 8> Queue;
2383 Class = Class->getCanonicalDecl();
2385 for (const auto &I : Current->bases()) {
2386 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2390 Base = Base->getDefinition();
2394 if (Base->getCanonicalDecl() == Class)
2397 Queue.push_back(Base);
2403 Current = Queue.pop_back_val();
2409 /// Check the validity of a C++ base class specifier.
2411 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2412 /// and returns NULL otherwise.
2414 Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2415 SourceRange SpecifierRange,
2416 bool Virtual, AccessSpecifier Access,
2417 TypeSourceInfo *TInfo,
2418 SourceLocation EllipsisLoc) {
2419 QualType BaseType = TInfo->getType();
2421 // C++ [class.union]p1:
2422 // A union shall not have base classes.
2423 if (Class->isUnion()) {
2424 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2429 if (EllipsisLoc.isValid() &&
2430 !TInfo->getType()->containsUnexpandedParameterPack()) {
2431 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2432 << TInfo->getTypeLoc().getSourceRange();
2433 EllipsisLoc = SourceLocation();
2436 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2438 if (BaseType->isDependentType()) {
2439 // Make sure that we don't have circular inheritance among our dependent
2440 // bases. For non-dependent bases, the check for completeness below handles
2442 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2443 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2444 ((BaseDecl = BaseDecl->getDefinition()) &&
2445 findCircularInheritance(Class, BaseDecl))) {
2446 Diag(BaseLoc, diag::err_circular_inheritance)
2447 << BaseType << Context.getTypeDeclType(Class);
2449 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2450 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2457 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2458 Class->getTagKind() == TTK_Class,
2459 Access, TInfo, EllipsisLoc);
2462 // Base specifiers must be record types.
2463 if (!BaseType->isRecordType()) {
2464 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2468 // C++ [class.union]p1:
2469 // A union shall not be used as a base class.
2470 if (BaseType->isUnionType()) {
2471 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2475 // For the MS ABI, propagate DLL attributes to base class templates.
2476 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2477 if (Attr *ClassAttr = getDLLAttr(Class)) {
2478 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2479 BaseType->getAsCXXRecordDecl())) {
2480 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2486 // C++ [class.derived]p2:
2487 // The class-name in a base-specifier shall not be an incompletely
2489 if (RequireCompleteType(BaseLoc, BaseType,
2490 diag::err_incomplete_base_class, SpecifierRange)) {
2491 Class->setInvalidDecl();
2495 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2496 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2497 assert(BaseDecl && "Record type has no declaration");
2498 BaseDecl = BaseDecl->getDefinition();
2499 assert(BaseDecl && "Base type is not incomplete, but has no definition");
2500 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2501 assert(CXXBaseDecl && "Base type is not a C++ type");
2503 // Microsoft docs say:
2504 // "If a base-class has a code_seg attribute, derived classes must have the
2506 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2507 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2508 if ((DerivedCSA || BaseCSA) &&
2509 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2510 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2511 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2516 // A class which contains a flexible array member is not suitable for use as a
2518 // - If the layout determines that a base comes before another base,
2519 // the flexible array member would index into the subsequent base.
2520 // - If the layout determines that base comes before the derived class,
2521 // the flexible array member would index into the derived class.
2522 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2523 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2524 << CXXBaseDecl->getDeclName();
2529 // If a class is marked final and it appears as a base-type-specifier in
2530 // base-clause, the program is ill-formed.
2531 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2532 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2533 << CXXBaseDecl->getDeclName()
2534 << FA->isSpelledAsSealed();
2535 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2536 << CXXBaseDecl->getDeclName() << FA->getRange();
2540 if (BaseDecl->isInvalidDecl())
2541 Class->setInvalidDecl();
2543 // Create the base specifier.
2544 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2545 Class->getTagKind() == TTK_Class,
2546 Access, TInfo, EllipsisLoc);
2549 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2550 /// one entry in the base class list of a class specifier, for
2552 /// class foo : public bar, virtual private baz {
2553 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2555 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2556 ParsedAttributes &Attributes,
2557 bool Virtual, AccessSpecifier Access,
2558 ParsedType basetype, SourceLocation BaseLoc,
2559 SourceLocation EllipsisLoc) {
2563 AdjustDeclIfTemplate(classdecl);
2564 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2568 // We haven't yet attached the base specifiers.
2569 Class->setIsParsingBaseSpecifiers();
2571 // We do not support any C++11 attributes on base-specifiers yet.
2572 // Diagnose any attributes we see.
2573 for (const ParsedAttr &AL : Attributes) {
2574 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2576 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2577 ? (unsigned)diag::warn_unknown_attribute_ignored
2578 : (unsigned)diag::err_base_specifier_attribute)
2582 TypeSourceInfo *TInfo = nullptr;
2583 GetTypeFromParser(basetype, &TInfo);
2585 if (EllipsisLoc.isInvalid() &&
2586 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2590 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2591 Virtual, Access, TInfo,
2595 Class->setInvalidDecl();
2600 /// Use small set to collect indirect bases. As this is only used
2601 /// locally, there's no need to abstract the small size parameter.
2602 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2604 /// Recursively add the bases of Type. Don't add Type itself.
2606 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2607 const QualType &Type)
2609 // Even though the incoming type is a base, it might not be
2610 // a class -- it could be a template parm, for instance.
2611 if (auto Rec = Type->getAs<RecordType>()) {
2612 auto Decl = Rec->getAsCXXRecordDecl();
2614 // Iterate over its bases.
2615 for (const auto &BaseSpec : Decl->bases()) {
2616 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2617 .getUnqualifiedType();
2618 if (Set.insert(Base).second)
2619 // If we've not already seen it, recurse.
2620 NoteIndirectBases(Context, Set, Base);
2625 /// Performs the actual work of attaching the given base class
2626 /// specifiers to a C++ class.
2627 bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2628 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2632 // Used to keep track of which base types we have already seen, so
2633 // that we can properly diagnose redundant direct base types. Note
2634 // that the key is always the unqualified canonical type of the base
2636 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2638 // Used to track indirect bases so we can see if a direct base is
2640 IndirectBaseSet IndirectBaseTypes;
2642 // Copy non-redundant base specifiers into permanent storage.
2643 unsigned NumGoodBases = 0;
2644 bool Invalid = false;
2645 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2646 QualType NewBaseType
2647 = Context.getCanonicalType(Bases[idx]->getType());
2648 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2650 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2652 // C++ [class.mi]p3:
2653 // A class shall not be specified as a direct base class of a
2654 // derived class more than once.
2655 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2656 << KnownBase->getType() << Bases[idx]->getSourceRange();
2658 // Delete the duplicate base class specifier; we're going to
2659 // overwrite its pointer later.
2660 Context.Deallocate(Bases[idx]);
2664 // Okay, add this new base class.
2665 KnownBase = Bases[idx];
2666 Bases[NumGoodBases++] = Bases[idx];
2668 // Note this base's direct & indirect bases, if there could be ambiguity.
2669 if (Bases.size() > 1)
2670 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2672 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2673 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2674 if (Class->isInterface() &&
2675 (!RD->isInterfaceLike() ||
2676 KnownBase->getAccessSpecifier() != AS_public)) {
2677 // The Microsoft extension __interface does not permit bases that
2678 // are not themselves public interfaces.
2679 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2680 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2681 << RD->getSourceRange();
2684 if (RD->hasAttr<WeakAttr>())
2685 Class->addAttr(WeakAttr::CreateImplicit(Context));
2690 // Attach the remaining base class specifiers to the derived class.
2691 Class->setBases(Bases.data(), NumGoodBases);
2693 // Check that the only base classes that are duplicate are virtual.
2694 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2695 // Check whether this direct base is inaccessible due to ambiguity.
2696 QualType BaseType = Bases[idx]->getType();
2698 // Skip all dependent types in templates being used as base specifiers.
2699 // Checks below assume that the base specifier is a CXXRecord.
2700 if (BaseType->isDependentType())
2703 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2704 .getUnqualifiedType();
2706 if (IndirectBaseTypes.count(CanonicalBase)) {
2707 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2708 /*DetectVirtual=*/true);
2710 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2714 if (Paths.isAmbiguous(CanonicalBase))
2715 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2716 << BaseType << getAmbiguousPathsDisplayString(Paths)
2717 << Bases[idx]->getSourceRange();
2719 assert(Bases[idx]->isVirtual());
2722 // Delete the base class specifier, since its data has been copied
2723 // into the CXXRecordDecl.
2724 Context.Deallocate(Bases[idx]);
2730 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2731 /// class, after checking whether there are any duplicate base
2733 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2734 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2735 if (!ClassDecl || Bases.empty())
2738 AdjustDeclIfTemplate(ClassDecl);
2739 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2742 /// Determine whether the type \p Derived is a C++ class that is
2743 /// derived from the type \p Base.
2744 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2745 if (!getLangOpts().CPlusPlus)
2748 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2752 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2756 // If either the base or the derived type is invalid, don't try to
2757 // check whether one is derived from the other.
2758 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2761 // FIXME: In a modules build, do we need the entire path to be visible for us
2762 // to be able to use the inheritance relationship?
2763 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2766 return DerivedRD->isDerivedFrom(BaseRD);
2769 /// Determine whether the type \p Derived is a C++ class that is
2770 /// derived from the type \p Base.
2771 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2772 CXXBasePaths &Paths) {
2773 if (!getLangOpts().CPlusPlus)
2776 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2780 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2784 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2787 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2790 static void BuildBasePathArray(const CXXBasePath &Path,
2791 CXXCastPath &BasePathArray) {
2792 // We first go backward and check if we have a virtual base.
2793 // FIXME: It would be better if CXXBasePath had the base specifier for
2794 // the nearest virtual base.
2796 for (unsigned I = Path.size(); I != 0; --I) {
2797 if (Path[I - 1].Base->isVirtual()) {
2803 // Now add all bases.
2804 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2805 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2809 void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2810 CXXCastPath &BasePathArray) {
2811 assert(BasePathArray.empty() && "Base path array must be empty!");
2812 assert(Paths.isRecordingPaths() && "Must record paths!");
2813 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2815 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2816 /// conversion (where Derived and Base are class types) is
2817 /// well-formed, meaning that the conversion is unambiguous (and
2818 /// that all of the base classes are accessible). Returns true
2819 /// and emits a diagnostic if the code is ill-formed, returns false
2820 /// otherwise. Loc is the location where this routine should point to
2821 /// if there is an error, and Range is the source range to highlight
2822 /// if there is an error.
2824 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2825 /// diagnostic for the respective type of error will be suppressed, but the
2826 /// check for ill-formed code will still be performed.
2828 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2829 unsigned InaccessibleBaseID,
2830 unsigned AmbigiousBaseConvID,
2831 SourceLocation Loc, SourceRange Range,
2832 DeclarationName Name,
2833 CXXCastPath *BasePath,
2834 bool IgnoreAccess) {
2835 // First, determine whether the path from Derived to Base is
2836 // ambiguous. This is slightly more expensive than checking whether
2837 // the Derived to Base conversion exists, because here we need to
2838 // explore multiple paths to determine if there is an ambiguity.
2839 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2840 /*DetectVirtual=*/false);
2841 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2842 if (!DerivationOkay)
2845 const CXXBasePath *Path = nullptr;
2846 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2847 Path = &Paths.front();
2849 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2850 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2851 // user to access such bases.
2852 if (!Path && getLangOpts().MSVCCompat) {
2853 for (const CXXBasePath &PossiblePath : Paths) {
2854 if (PossiblePath.size() == 1) {
2855 Path = &PossiblePath;
2856 if (AmbigiousBaseConvID)
2857 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2858 << Base << Derived << Range;
2865 if (!IgnoreAccess) {
2866 // Check that the base class can be accessed.
2868 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2869 case AR_inaccessible:
2878 // Build a base path if necessary.
2880 ::BuildBasePathArray(*Path, *BasePath);
2884 if (AmbigiousBaseConvID) {
2885 // We know that the derived-to-base conversion is ambiguous, and
2886 // we're going to produce a diagnostic. Perform the derived-to-base
2887 // search just one more time to compute all of the possible paths so
2888 // that we can print them out. This is more expensive than any of
2889 // the previous derived-to-base checks we've done, but at this point
2890 // performance isn't as much of an issue.
2892 Paths.setRecordingPaths(true);
2893 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2894 assert(StillOkay && "Can only be used with a derived-to-base conversion");
2897 // Build up a textual representation of the ambiguous paths, e.g.,
2898 // D -> B -> A, that will be used to illustrate the ambiguous
2899 // conversions in the diagnostic. We only print one of the paths
2900 // to each base class subobject.
2901 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2903 Diag(Loc, AmbigiousBaseConvID)
2904 << Derived << Base << PathDisplayStr << Range << Name;
2910 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2911 SourceLocation Loc, SourceRange Range,
2912 CXXCastPath *BasePath,
2913 bool IgnoreAccess) {
2914 return CheckDerivedToBaseConversion(
2915 Derived, Base, diag::err_upcast_to_inaccessible_base,
2916 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2917 BasePath, IgnoreAccess);
2921 /// Builds a string representing ambiguous paths from a
2922 /// specific derived class to different subobjects of the same base
2925 /// This function builds a string that can be used in error messages
2926 /// to show the different paths that one can take through the
2927 /// inheritance hierarchy to go from the derived class to different
2928 /// subobjects of a base class. The result looks something like this:
2930 /// struct D -> struct B -> struct A
2931 /// struct D -> struct C -> struct A
2933 std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
2934 std::string PathDisplayStr;
2935 std::set<unsigned> DisplayedPaths;
2936 for (CXXBasePaths::paths_iterator Path = Paths.begin();
2937 Path != Paths.end(); ++Path) {
2938 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2939 // We haven't displayed a path to this particular base
2940 // class subobject yet.
2941 PathDisplayStr += "\n ";
2942 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2943 for (CXXBasePath::const_iterator Element = Path->begin();
2944 Element != Path->end(); ++Element)
2945 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2949 return PathDisplayStr;
2952 //===----------------------------------------------------------------------===//
2953 // C++ class member Handling
2954 //===----------------------------------------------------------------------===//
2956 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2957 bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
2958 SourceLocation ColonLoc,
2959 const ParsedAttributesView &Attrs) {
2960 assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2961 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2963 CurContext->addHiddenDecl(ASDecl);
2964 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2967 /// CheckOverrideControl - Check C++11 override control semantics.
2968 void Sema::CheckOverrideControl(NamedDecl *D) {
2969 if (D->isInvalidDecl())
2972 // We only care about "override" and "final" declarations.
2973 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2976 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2978 // We can't check dependent instance methods.
2979 if (MD && MD->isInstance() &&
2980 (MD->getParent()->hasAnyDependentBases() ||
2981 MD->getType()->isDependentType()))
2984 if (MD && !MD->isVirtual()) {
2985 // If we have a non-virtual method, check if if hides a virtual method.
2986 // (In that case, it's most likely the method has the wrong type.)
2987 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2988 FindHiddenVirtualMethods(MD, OverloadedMethods);
2990 if (!OverloadedMethods.empty()) {
2991 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2992 Diag(OA->getLocation(),
2993 diag::override_keyword_hides_virtual_member_function)
2994 << "override" << (OverloadedMethods.size() > 1);
2995 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2996 Diag(FA->getLocation(),
2997 diag::override_keyword_hides_virtual_member_function)
2998 << (FA->isSpelledAsSealed() ? "sealed" : "final")
2999 << (OverloadedMethods.size() > 1);
3001 NoteHiddenVirtualMethods(MD, OverloadedMethods);
3002 MD->setInvalidDecl();
3005 // Fall through into the general case diagnostic.
3006 // FIXME: We might want to attempt typo correction here.
3009 if (!MD || !MD->isVirtual()) {
3010 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3011 Diag(OA->getLocation(),
3012 diag::override_keyword_only_allowed_on_virtual_member_functions)
3013 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3014 D->dropAttr<OverrideAttr>();
3016 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3017 Diag(FA->getLocation(),
3018 diag::override_keyword_only_allowed_on_virtual_member_functions)
3019 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3020 << FixItHint::CreateRemoval(FA->getLocation());
3021 D->dropAttr<FinalAttr>();
3026 // C++11 [class.virtual]p5:
3027 // If a function is marked with the virt-specifier override and
3028 // does not override a member function of a base class, the program is
3030 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3031 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3032 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3033 << MD->getDeclName();
3036 void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D) {
3037 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3039 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3040 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3043 SourceLocation Loc = MD->getLocation();
3044 SourceLocation SpellingLoc = Loc;
3045 if (getSourceManager().isMacroArgExpansion(Loc))
3046 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3047 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3048 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3051 if (MD->size_overridden_methods() > 0) {
3052 unsigned DiagID = isa<CXXDestructorDecl>(MD)
3053 ? diag::warn_destructor_marked_not_override_overriding
3054 : diag::warn_function_marked_not_override_overriding;
3055 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3056 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3057 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3061 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3062 /// function overrides a virtual member function marked 'final', according to
3063 /// C++11 [class.virtual]p4.
3064 bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3065 const CXXMethodDecl *Old) {
3066 FinalAttr *FA = Old->getAttr<FinalAttr>();
3070 Diag(New->getLocation(), diag::err_final_function_overridden)
3071 << New->getDeclName()
3072 << FA->isSpelledAsSealed();
3073 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3077 static bool InitializationHasSideEffects(const FieldDecl &FD) {
3078 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3079 // FIXME: Destruction of ObjC lifetime types has side-effects.
3080 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3081 return !RD->isCompleteDefinition() ||
3082 !RD->hasTrivialDefaultConstructor() ||
3083 !RD->hasTrivialDestructor();
3087 static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3088 ParsedAttributesView::const_iterator Itr =
3089 llvm::find_if(list, [](const ParsedAttr &AL) {
3090 return AL.isDeclspecPropertyAttribute();
3092 if (Itr != list.end())
3097 // Check if there is a field shadowing.
3098 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3099 DeclarationName FieldName,
3100 const CXXRecordDecl *RD,
3102 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3105 // To record a shadowed field in a base
3106 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3107 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3108 CXXBasePath &Path) {
3109 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3110 // Record an ambiguous path directly
3111 if (Bases.find(Base) != Bases.end())
3113 for (const auto Field : Base->lookup(FieldName)) {
3114 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3115 Field->getAccess() != AS_private) {
3116 assert(Field->getAccess() != AS_none);
3117 assert(Bases.find(Base) == Bases.end());
3118 Bases[Base] = Field;
3125 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3126 /*DetectVirtual=*/true);
3127 if (!RD->lookupInBases(FieldShadowed, Paths))
3130 for (const auto &P : Paths) {
3131 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3132 auto It = Bases.find(Base);
3133 // Skip duplicated bases
3134 if (It == Bases.end())
3136 auto BaseField = It->second;
3137 assert(BaseField->getAccess() != AS_private);
3139 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3140 Diag(Loc, diag::warn_shadow_field)
3141 << FieldName << RD << Base << DeclIsField;
3142 Diag(BaseField->getLocation(), diag::note_shadow_field);
3148 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3149 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3150 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
3151 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3152 /// present (but parsing it has been deferred).
3154 Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3155 MultiTemplateParamsArg TemplateParameterLists,
3156 Expr *BW, const VirtSpecifiers &VS,
3157 InClassInitStyle InitStyle) {
3158 const DeclSpec &DS = D.getDeclSpec();
3159 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3160 DeclarationName Name = NameInfo.getName();
3161 SourceLocation Loc = NameInfo.getLoc();
3163 // For anonymous bitfields, the location should point to the type.
3164 if (Loc.isInvalid())
3165 Loc = D.getBeginLoc();
3167 Expr *BitWidth = static_cast<Expr*>(BW);
3169 assert(isa<CXXRecordDecl>(CurContext));
3170 assert(!DS.isFriendSpecified());
3172 bool isFunc = D.isDeclarationOfFunction();
3173 const ParsedAttr *MSPropertyAttr =
3174 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3176 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3177 // The Microsoft extension __interface only permits public member functions
3178 // and prohibits constructors, destructors, operators, non-public member
3179 // functions, static methods and data members.
3180 unsigned InvalidDecl;
3181 bool ShowDeclName = true;
3183 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3187 else if (AS != AS_public)
3189 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3191 else switch (Name.getNameKind()) {
3192 case DeclarationName::CXXConstructorName:
3194 ShowDeclName = false;
3197 case DeclarationName::CXXDestructorName:
3199 ShowDeclName = false;
3202 case DeclarationName::CXXOperatorName:
3203 case DeclarationName::CXXConversionFunctionName:
3214 Diag(Loc, diag::err_invalid_member_in_interface)
3215 << (InvalidDecl-1) << Name;
3217 Diag(Loc, diag::err_invalid_member_in_interface)
3218 << (InvalidDecl-1) << "";
3223 // C++ 9.2p6: A member shall not be declared to have automatic storage
3224 // duration (auto, register) or with the extern storage-class-specifier.
3225 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3226 // data members and cannot be applied to names declared const or static,
3227 // and cannot be applied to reference members.
3228 switch (DS.getStorageClassSpec()) {
3229 case DeclSpec::SCS_unspecified:
3230 case DeclSpec::SCS_typedef:
3231 case DeclSpec::SCS_static:
3233 case DeclSpec::SCS_mutable:
3235 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3237 // FIXME: It would be nicer if the keyword was ignored only for this
3238 // declarator. Otherwise we could get follow-up errors.
3239 D.getMutableDeclSpec().ClearStorageClassSpecs();
3243 Diag(DS.getStorageClassSpecLoc(),
3244 diag::err_storageclass_invalid_for_member);
3245 D.getMutableDeclSpec().ClearStorageClassSpecs();
3249 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3250 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3253 if (DS.hasConstexprSpecifier() && isInstField) {
3254 SemaDiagnosticBuilder B =
3255 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3256 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3257 if (InitStyle == ICIS_NoInit) {
3259 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3260 B << FixItHint::CreateRemoval(ConstexprLoc);
3262 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3263 D.getMutableDeclSpec().ClearConstexprSpec();
3264 const char *PrevSpec;
3266 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3267 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3269 assert(!Failed && "Making a constexpr member const shouldn't fail");
3273 const char *PrevSpec;
3275 if (D.getMutableDeclSpec().SetStorageClassSpec(
3276 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3277 Context.getPrintingPolicy())) {
3278 assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3279 "This is the only DeclSpec that should fail to be applied");
3282 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3283 isInstField = false;
3290 CXXScopeSpec &SS = D.getCXXScopeSpec();
3292 // Data members must have identifiers for names.
3293 if (!Name.isIdentifier()) {
3294 Diag(Loc, diag::err_bad_variable_name)
3299 IdentifierInfo *II = Name.getAsIdentifierInfo();
3301 // Member field could not be with "template" keyword.
3302 // So TemplateParameterLists should be empty in this case.
3303 if (TemplateParameterLists.size()) {
3304 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3305 if (TemplateParams->size()) {
3306 // There is no such thing as a member field template.
3307 Diag(D.getIdentifierLoc(), diag::err_template_member)
3309 << SourceRange(TemplateParams->getTemplateLoc(),
3310 TemplateParams->getRAngleLoc());
3312 // There is an extraneous 'template<>' for this member.
3313 Diag(TemplateParams->getTemplateLoc(),
3314 diag::err_template_member_noparams)
3316 << SourceRange(TemplateParams->getTemplateLoc(),
3317 TemplateParams->getRAngleLoc());
3322 if (SS.isSet() && !SS.isInvalid()) {
3323 // The user provided a superfluous scope specifier inside a class
3329 if (DeclContext *DC = computeDeclContext(SS, false))
3330 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3331 D.getName().getKind() ==
3332 UnqualifiedIdKind::IK_TemplateId);
3334 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3335 << Name << SS.getRange();
3340 if (MSPropertyAttr) {
3341 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3342 BitWidth, InitStyle, AS, *MSPropertyAttr);
3345 isInstField = false;
3347 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3348 BitWidth, InitStyle, AS);
3353 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3355 Member = HandleDeclarator(S, D, TemplateParameterLists);
3359 // Non-instance-fields can't have a bitfield.
3361 if (Member->isInvalidDecl()) {
3362 // don't emit another diagnostic.
3363 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3364 // C++ 9.6p3: A bit-field shall not be a static member.
3365 // "static member 'A' cannot be a bit-field"
3366 Diag(Loc, diag::err_static_not_bitfield)
3367 << Name << BitWidth->getSourceRange();
3368 } else if (isa<TypedefDecl>(Member)) {
3369 // "typedef member 'x' cannot be a bit-field"
3370 Diag(Loc, diag::err_typedef_not_bitfield)
3371 << Name << BitWidth->getSourceRange();
3373 // A function typedef ("typedef int f(); f a;").
3374 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3375 Diag(Loc, diag::err_not_integral_type_bitfield)
3376 << Name << cast<ValueDecl>(Member)->getType()
3377 << BitWidth->getSourceRange();
3381 Member->setInvalidDecl();
3384 NamedDecl *NonTemplateMember = Member;
3385 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3386 NonTemplateMember = FunTmpl->getTemplatedDecl();
3387 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3388 NonTemplateMember = VarTmpl->getTemplatedDecl();
3390 Member->setAccess(AS);
3392 // If we have declared a member function template or static data member
3393 // template, set the access of the templated declaration as well.
3394 if (NonTemplateMember != Member)
3395 NonTemplateMember->setAccess(AS);
3397 // C++ [temp.deduct.guide]p3:
3398 // A deduction guide [...] for a member class template [shall be
3399 // declared] with the same access [as the template].
3400 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3401 auto *TD = DG->getDeducedTemplate();
3402 // Access specifiers are only meaningful if both the template and the
3403 // deduction guide are from the same scope.
3404 if (AS != TD->getAccess() &&
3405 TD->getDeclContext()->getRedeclContext()->Equals(
3406 DG->getDeclContext()->getRedeclContext())) {
3407 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3408 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3410 const AccessSpecDecl *LastAccessSpec = nullptr;
3411 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3412 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3413 LastAccessSpec = AccessSpec;
3415 assert(LastAccessSpec && "differing access with no access specifier");
3416 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3422 if (VS.isOverrideSpecified())
3423 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3424 AttributeCommonInfo::AS_Keyword));
3425 if (VS.isFinalSpecified())
3426 Member->addAttr(FinalAttr::Create(
3427 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3428 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3430 if (VS.getLastLocation().isValid()) {
3431 // Update the end location of a method that has a virt-specifiers.
3432 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3433 MD->setRangeEnd(VS.getLastLocation());
3436 CheckOverrideControl(Member);
3438 assert((Name || isInstField) && "No identifier for non-field ?");
3441 FieldDecl *FD = cast<FieldDecl>(Member);
3442 FieldCollector->Add(FD);
3444 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3445 // Remember all explicit private FieldDecls that have a name, no side
3446 // effects and are not part of a dependent type declaration.
3447 if (!FD->isImplicit() && FD->getDeclName() &&
3448 FD->getAccess() == AS_private &&
3449 !FD->hasAttr<UnusedAttr>() &&
3450 !FD->getParent()->isDependentContext() &&
3451 !InitializationHasSideEffects(*FD))
3452 UnusedPrivateFields.insert(FD);
3460 class UninitializedFieldVisitor
3461 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3463 // List of Decls to generate a warning on. Also remove Decls that become
3465 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3466 // List of base classes of the record. Classes are removed after their
3468 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3469 // Vector of decls to be removed from the Decl set prior to visiting the
3470 // nodes. These Decls may have been initialized in the prior initializer.
3471 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3472 // If non-null, add a note to the warning pointing back to the constructor.
3473 const CXXConstructorDecl *Constructor;
3474 // Variables to hold state when processing an initializer list. When
3475 // InitList is true, special case initialization of FieldDecls matching
3476 // InitListFieldDecl.
3478 FieldDecl *InitListFieldDecl;
3479 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3482 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
3483 UninitializedFieldVisitor(Sema &S,
3484 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3485 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3486 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3487 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3489 // Returns true if the use of ME is not an uninitialized use.
3490 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3491 bool CheckReferenceOnly) {
3492 llvm::SmallVector<FieldDecl*, 4> Fields;
3493 bool ReferenceField = false;
3495 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3498 Fields.push_back(FD);
3499 if (FD->getType()->isReferenceType())
3500 ReferenceField = true;
3501 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3504 // Binding a reference to an uninitialized field is not an
3505 // uninitialized use.
3506 if (CheckReferenceOnly && !ReferenceField)
3509 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3510 // Discard the first field since it is the field decl that is being
3512 for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3513 UsedFieldIndex.push_back((*I)->getFieldIndex());
3516 for (auto UsedIter = UsedFieldIndex.begin(),
3517 UsedEnd = UsedFieldIndex.end(),
3518 OrigIter = InitFieldIndex.begin(),
3519 OrigEnd = InitFieldIndex.end();
3520 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3521 if (*UsedIter < *OrigIter)
3523 if (*UsedIter > *OrigIter)
3530 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3532 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3535 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3537 MemberExpr *FieldME = ME;
3539 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3542 while (MemberExpr *SubME =
3543 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3545 if (isa<VarDecl>(SubME->getMemberDecl()))
3548 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3549 if (!FD->isAnonymousStructOrUnion())
3552 if (!FieldME->getType().isPODType(S.Context))
3553 AllPODFields = false;
3555 Base = SubME->getBase();
3558 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3561 if (AddressOf && AllPODFields)
3564 ValueDecl* FoundVD = FieldME->getMemberDecl();
3566 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3567 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3568 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3571 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3572 QualType T = BaseCast->getType();
3573 if (T->isPointerType() &&
3574 BaseClasses.count(T->getPointeeType())) {
3575 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3576 << T->getPointeeType() << FoundVD;
3581 if (!Decls.count(FoundVD))
3584 const bool IsReference = FoundVD->getType()->isReferenceType();
3586 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3587 // Special checking for initializer lists.
3588 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3592 // Prevent double warnings on use of unbounded references.
3593 if (CheckReferenceOnly && !IsReference)
3597 unsigned diag = IsReference
3598 ? diag::warn_reference_field_is_uninit
3599 : diag::warn_field_is_uninit;
3600 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3602 S.Diag(Constructor->getLocation(),
3603 diag::note_uninit_in_this_constructor)
3604 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3608 void HandleValue(Expr *E, bool AddressOf) {
3609 E = E->IgnoreParens();
3611 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3612 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3613 AddressOf /*AddressOf*/);
3617 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3618 Visit(CO->getCond());
3619 HandleValue(CO->getTrueExpr(), AddressOf);
3620 HandleValue(CO->getFalseExpr(), AddressOf);
3624 if (BinaryConditionalOperator *BCO =
3625 dyn_cast<BinaryConditionalOperator>(E)) {
3626 Visit(BCO->getCond());
3627 HandleValue(BCO->getFalseExpr(), AddressOf);
3631 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3632 HandleValue(OVE->getSourceExpr(), AddressOf);
3636 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3637 switch (BO->getOpcode()) {
3642 HandleValue(BO->getLHS(), AddressOf);
3643 Visit(BO->getRHS());
3646 Visit(BO->getLHS());
3647 HandleValue(BO->getRHS(), AddressOf);
3655 void CheckInitListExpr(InitListExpr *ILE) {
3656 InitFieldIndex.push_back(0);
3657 for (auto Child : ILE->children()) {
3658 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3659 CheckInitListExpr(SubList);
3663 ++InitFieldIndex.back();
3665 InitFieldIndex.pop_back();
3668 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3669 FieldDecl *Field, const Type *BaseClass) {
3670 // Remove Decls that may have been initialized in the previous
3672 for (ValueDecl* VD : DeclsToRemove)
3674 DeclsToRemove.clear();
3676 Constructor = FieldConstructor;
3677 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3681 InitListFieldDecl = Field;
3682 InitFieldIndex.clear();
3683 CheckInitListExpr(ILE);
3692 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3695 void VisitMemberExpr(MemberExpr *ME) {
3696 // All uses of unbounded reference fields will warn.
3697 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3700 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3701 if (E->getCastKind() == CK_LValueToRValue) {
3702 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3706 Inherited::VisitImplicitCastExpr(E);
3709 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3710 if (E->getConstructor()->isCopyConstructor()) {
3711 Expr *ArgExpr = E->getArg(0);
3712 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3713 if (ILE->getNumInits() == 1)
3714 ArgExpr = ILE->getInit(0);
3715 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3716 if (ICE->getCastKind() == CK_NoOp)
3717 ArgExpr = ICE->getSubExpr();
3718 HandleValue(ArgExpr, false /*AddressOf*/);
3721 Inherited::VisitCXXConstructExpr(E);
3724 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3725 Expr *Callee = E->getCallee();
3726 if (isa<MemberExpr>(Callee)) {
3727 HandleValue(Callee, false /*AddressOf*/);
3728 for (auto Arg : E->arguments())
3733 Inherited::VisitCXXMemberCallExpr(E);
3736 void VisitCallExpr(CallExpr *E) {
3737 // Treat std::move as a use.
3738 if (E->isCallToStdMove()) {
3739 HandleValue(E->getArg(0), /*AddressOf=*/false);
3743 Inherited::VisitCallExpr(E);
3746 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3747 Expr *Callee = E->getCallee();
3749 if (isa<UnresolvedLookupExpr>(Callee))
3750 return Inherited::VisitCXXOperatorCallExpr(E);
3753 for (auto Arg : E->arguments())
3754 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3757 void VisitBinaryOperator(BinaryOperator *E) {
3758 // If a field assignment is detected, remove the field from the
3759 // uninitiailized field set.
3760 if (E->getOpcode() == BO_Assign)
3761 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3762 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3763 if (!FD->getType()->isReferenceType())
3764 DeclsToRemove.push_back(FD);
3766 if (E->isCompoundAssignmentOp()) {
3767 HandleValue(E->getLHS(), false /*AddressOf*/);
3772 Inherited::VisitBinaryOperator(E);
3775 void VisitUnaryOperator(UnaryOperator *E) {
3776 if (E->isIncrementDecrementOp()) {
3777 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3780 if (E->getOpcode() == UO_AddrOf) {
3781 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3782 HandleValue(ME->getBase(), true /*AddressOf*/);
3787 Inherited::VisitUnaryOperator(E);
3791 // Diagnose value-uses of fields to initialize themselves, e.g.
3793 // where foo is not also a parameter to the constructor.
3794 // Also diagnose across field uninitialized use such as
3796 // TODO: implement -Wuninitialized and fold this into that framework.
3797 static void DiagnoseUninitializedFields(
3798 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3800 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3801 Constructor->getLocation())) {
3805 if (Constructor->isInvalidDecl())
3808 const CXXRecordDecl *RD = Constructor->getParent();
3810 if (RD->isDependentContext())
3813 // Holds fields that are uninitialized.
3814 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3816 // At the beginning, all fields are uninitialized.
3817 for (auto *I : RD->decls()) {
3818 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3819 UninitializedFields.insert(FD);
3820 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3821 UninitializedFields.insert(IFD->getAnonField());
3825 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3826 for (auto I : RD->bases())
3827 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3829 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3832 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3833 UninitializedFields,
3834 UninitializedBaseClasses);
3836 for (const auto *FieldInit : Constructor->inits()) {
3837 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3840 Expr *InitExpr = FieldInit->getInit();
3844 if (CXXDefaultInitExpr *Default =
3845 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3846 InitExpr = Default->getExpr();
3849 // In class initializers will point to the constructor.
3850 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3851 FieldInit->getAnyMember(),
3852 FieldInit->getBaseClass());
3854 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3855 FieldInit->getAnyMember(),
3856 FieldInit->getBaseClass());
3862 /// Enter a new C++ default initializer scope. After calling this, the
3863 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3864 /// parsing or instantiating the initializer failed.
3865 void Sema::ActOnStartCXXInClassMemberInitializer() {
3866 // Create a synthetic function scope to represent the call to the constructor
3867 // that notionally surrounds a use of this initializer.
3868 PushFunctionScope();
3871 void Sema::ActOnStartTrailingRequiresClause(Scope *S, Declarator &D) {
3872 if (!D.isFunctionDeclarator())
3874 auto &FTI = D.getFunctionTypeInfo();
3877 for (auto &Param : ArrayRef<DeclaratorChunk::ParamInfo>(FTI.Params,
3879 auto *ParamDecl = cast<NamedDecl>(Param.Param);
3880 if (ParamDecl->getDeclName())
3881 PushOnScopeChains(ParamDecl, S, /*AddToContext=*/false);
3885 ExprResult Sema::ActOnFinishTrailingRequiresClause(ExprResult ConstraintExpr) {
3886 if (ConstraintExpr.isInvalid())
3888 return CorrectDelayedTyposInExpr(ConstraintExpr);
3891 /// This is invoked after parsing an in-class initializer for a
3892 /// non-static C++ class member, and after instantiating an in-class initializer
3893 /// in a class template. Such actions are deferred until the class is complete.
3894 void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
3895 SourceLocation InitLoc,
3897 // Pop the notional constructor scope we created earlier.
3898 PopFunctionScopeInfo(nullptr, D);
3900 FieldDecl *FD = dyn_cast<FieldDecl>(D);
3901 assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3902 "must set init style when field is created");
3905 D->setInvalidDecl();
3907 FD->removeInClassInitializer();
3911 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3912 FD->setInvalidDecl();
3913 FD->removeInClassInitializer();
3917 ExprResult Init = InitExpr;
3918 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3919 InitializedEntity Entity =
3920 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
3921 InitializationKind Kind =
3922 FD->getInClassInitStyle() == ICIS_ListInit
3923 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
3924 InitExpr->getBeginLoc(),
3925 InitExpr->getEndLoc())
3926 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
3927 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3928 Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3929 if (Init.isInvalid()) {
3930 FD->setInvalidDecl();
3935 // C++11 [class.base.init]p7:
3936 // The initialization of each base and member constitutes a
3938 Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
3939 if (Init.isInvalid()) {
3940 FD->setInvalidDecl();
3944 InitExpr = Init.get();
3946 FD->setInClassInitializer(InitExpr);
3949 /// Find the direct and/or virtual base specifiers that
3950 /// correspond to the given base type, for use in base initialization
3951 /// within a constructor.
3952 static bool FindBaseInitializer(Sema &SemaRef,
3953 CXXRecordDecl *ClassDecl,
3955 const CXXBaseSpecifier *&DirectBaseSpec,
3956 const CXXBaseSpecifier *&VirtualBaseSpec) {
3957 // First, check for a direct base class.
3958 DirectBaseSpec = nullptr;
3959 for (const auto &Base : ClassDecl->bases()) {
3960 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3961 // We found a direct base of this type. That's what we're
3963 DirectBaseSpec = &Base;
3968 // Check for a virtual base class.
3969 // FIXME: We might be able to short-circuit this if we know in advance that
3970 // there are no virtual bases.
3971 VirtualBaseSpec = nullptr;
3972 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3973 // We haven't found a base yet; search the class hierarchy for a
3974 // virtual base class.
3975 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3976 /*DetectVirtual=*/false);
3977 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3978 SemaRef.Context.getTypeDeclType(ClassDecl),
3980 for (CXXBasePaths::paths_iterator Path = Paths.begin();
3981 Path != Paths.end(); ++Path) {
3982 if (Path->back().Base->isVirtual()) {
3983 VirtualBaseSpec = Path->back().Base;
3990 return DirectBaseSpec || VirtualBaseSpec;
3993 /// Handle a C++ member initializer using braced-init-list syntax.
3995 Sema::ActOnMemInitializer(Decl *ConstructorD,
3998 IdentifierInfo *MemberOrBase,
3999 ParsedType TemplateTypeTy,
4001 SourceLocation IdLoc,
4003 SourceLocation EllipsisLoc) {
4004 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4005 DS, IdLoc, InitList,
4009 /// Handle a C++ member initializer using parentheses syntax.
4011 Sema::ActOnMemInitializer(Decl *ConstructorD,
4014 IdentifierInfo *MemberOrBase,
4015 ParsedType TemplateTypeTy,
4017 SourceLocation IdLoc,
4018 SourceLocation LParenLoc,
4019 ArrayRef<Expr *> Args,
4020 SourceLocation RParenLoc,
4021 SourceLocation EllipsisLoc) {
4022 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
4023 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
4024 DS, IdLoc, List, EllipsisLoc);
4029 // Callback to only accept typo corrections that can be a valid C++ member
4030 // intializer: either a non-static field member or a base class.
4031 class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4033 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4034 : ClassDecl(ClassDecl) {}
4036 bool ValidateCandidate(const TypoCorrection &candidate) override {
4037 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4038 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4039 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4040 return isa<TypeDecl>(ND);
4045 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4046 return std::make_unique<MemInitializerValidatorCCC>(*this);
4050 CXXRecordDecl *ClassDecl;
4055 ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4057 ParsedType TemplateTypeTy,
4058 IdentifierInfo *MemberOrBase) {
4059 if (SS.getScopeRep() || TemplateTypeTy)
4061 DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
4065 if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
4066 (Member = dyn_cast<IndirectFieldDecl>(Result.front())))
4071 /// Handle a C++ member initializer.
4073 Sema::BuildMemInitializer(Decl *ConstructorD,
4076 IdentifierInfo *MemberOrBase,
4077 ParsedType TemplateTypeTy,
4079 SourceLocation IdLoc,
4081 SourceLocation EllipsisLoc) {
4082 ExprResult Res = CorrectDelayedTyposInExpr(Init);
4083 if (!Res.isUsable())
4090 AdjustDeclIfTemplate(ConstructorD);
4092 CXXConstructorDecl *Constructor
4093 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4095 // The user wrote a constructor initializer on a function that is
4096 // not a C++ constructor. Ignore the error for now, because we may
4097 // have more member initializers coming; we'll diagnose it just
4098 // once in ActOnMemInitializers.
4102 CXXRecordDecl *ClassDecl = Constructor->getParent();
4104 // C++ [class.base.init]p2:
4105 // Names in a mem-initializer-id are looked up in the scope of the
4106 // constructor's class and, if not found in that scope, are looked
4107 // up in the scope containing the constructor's definition.
4108 // [Note: if the constructor's class contains a member with the
4109 // same name as a direct or virtual base class of the class, a
4110 // mem-initializer-id naming the member or base class and composed
4111 // of a single identifier refers to the class member. A
4112 // mem-initializer-id for the hidden base class may be specified
4113 // using a qualified name. ]
4115 // Look for a member, first.
4116 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4117 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4118 if (EllipsisLoc.isValid())
4119 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4121 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4123 return BuildMemberInitializer(Member, Init, IdLoc);
4125 // It didn't name a member, so see if it names a class.
4127 TypeSourceInfo *TInfo = nullptr;
4129 if (TemplateTypeTy) {
4130 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4131 if (BaseType.isNull())
4133 } else if (DS.getTypeSpecType() == TST_decltype) {
4134 BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
4135 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4136 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4139 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4140 LookupParsedName(R, S, &SS);
4142 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4144 if (R.isAmbiguous()) return true;
4146 // We don't want access-control diagnostics here.
4147 R.suppressDiagnostics();
4149 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4150 bool NotUnknownSpecialization = false;
4151 DeclContext *DC = computeDeclContext(SS, false);
4152 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4153 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4155 if (!NotUnknownSpecialization) {
4156 // When the scope specifier can refer to a member of an unknown
4157 // specialization, we take it as a type name.
4158 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4159 SS.getWithLocInContext(Context),
4160 *MemberOrBase, IdLoc);
4161 if (BaseType.isNull())
4164 TInfo = Context.CreateTypeSourceInfo(BaseType);
4165 DependentNameTypeLoc TL =
4166 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4168 TL.setNameLoc(IdLoc);
4169 TL.setElaboratedKeywordLoc(SourceLocation());
4170 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4174 R.setLookupName(MemberOrBase);
4178 // If no results were found, try to correct typos.
4179 TypoCorrection Corr;
4180 MemInitializerValidatorCCC CCC(ClassDecl);
4181 if (R.empty() && BaseType.isNull() &&
4182 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4183 CCC, CTK_ErrorRecovery, ClassDecl))) {
4184 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4185 // We have found a non-static data member with a similar
4186 // name to what was typed; complain and initialize that
4189 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4190 << MemberOrBase << true);
4191 return BuildMemberInitializer(Member, Init, IdLoc);
4192 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4193 const CXXBaseSpecifier *DirectBaseSpec;
4194 const CXXBaseSpecifier *VirtualBaseSpec;
4195 if (FindBaseInitializer(*this, ClassDecl,
4196 Context.getTypeDeclType(Type),
4197 DirectBaseSpec, VirtualBaseSpec)) {
4198 // We have found a direct or virtual base class with a
4199 // similar name to what was typed; complain and initialize
4202 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4203 << MemberOrBase << false,
4204 PDiag() /*Suppress note, we provide our own.*/);
4206 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4208 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4209 << BaseSpec->getType() << BaseSpec->getSourceRange();
4216 if (!TyD && BaseType.isNull()) {
4217 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4218 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4223 if (BaseType.isNull()) {
4224 BaseType = Context.getTypeDeclType(TyD);
4225 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4227 BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
4229 TInfo = Context.CreateTypeSourceInfo(BaseType);
4230 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4231 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4232 TL.setElaboratedKeywordLoc(SourceLocation());
4233 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4239 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4241 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4245 Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4246 SourceLocation IdLoc) {
4247 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4248 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4249 assert((DirectMember || IndirectMember) &&
4250 "Member must be a FieldDecl or IndirectFieldDecl");
4252 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4255 if (Member->isInvalidDecl())
4259 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4260 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4261 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4262 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4264 // Template instantiation doesn't reconstruct ParenListExprs for us.
4268 SourceRange InitRange = Init->getSourceRange();
4270 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4271 // Can't check initialization for a member of dependent type or when
4272 // any of the arguments are type-dependent expressions.
4273 DiscardCleanupsInEvaluationContext();
4275 bool InitList = false;
4276 if (isa<InitListExpr>(Init)) {
4281 // Initialize the member.
4282 InitializedEntity MemberEntity =
4283 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4284 : InitializedEntity::InitializeMember(IndirectMember,
4286 InitializationKind Kind =
4287 InitList ? InitializationKind::CreateDirectList(
4288 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4289 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4290 InitRange.getEnd());
4292 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4293 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4295 if (MemberInit.isInvalid())
4298 // C++11 [class.base.init]p7:
4299 // The initialization of each base and member constitutes a
4301 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4302 /*DiscardedValue*/ false);
4303 if (MemberInit.isInvalid())
4306 Init = MemberInit.get();
4310 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4311 InitRange.getBegin(), Init,
4312 InitRange.getEnd());
4314 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4315 InitRange.getBegin(), Init,
4316 InitRange.getEnd());
4321 Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4322 CXXRecordDecl *ClassDecl) {
4323 SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4324 if (!LangOpts.CPlusPlus11)
4325 return Diag(NameLoc, diag::err_delegating_ctor)
4326 << TInfo->getTypeLoc().getLocalSourceRange();
4327 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4329 bool InitList = true;
4330 MultiExprArg Args = Init;
4331 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4333 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4336 SourceRange InitRange = Init->getSourceRange();
4337 // Initialize the object.
4338 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4339 QualType(ClassDecl->getTypeForDecl(), 0));
4340 InitializationKind Kind =
4341 InitList ? InitializationKind::CreateDirectList(
4342 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4343 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4344 InitRange.getEnd());
4345 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4346 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4348 if (DelegationInit.isInvalid())
4351 assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4352 "Delegating constructor with no target?");
4354 // C++11 [class.base.init]p7:
4355 // The initialization of each base and member constitutes a
4357 DelegationInit = ActOnFinishFullExpr(
4358 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4359 if (DelegationInit.isInvalid())
4362 // If we are in a dependent context, template instantiation will
4363 // perform this type-checking again. Just save the arguments that we
4364 // received in a ParenListExpr.
4365 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4366 // of the information that we have about the base
4367 // initializer. However, deconstructing the ASTs is a dicey process,
4368 // and this approach is far more likely to get the corner cases right.
4369 if (CurContext->isDependentContext())
4370 DelegationInit = Init;
4372 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4373 DelegationInit.getAs<Expr>(),
4374 InitRange.getEnd());
4378 Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4379 Expr *Init, CXXRecordDecl *ClassDecl,
4380 SourceLocation EllipsisLoc) {
4381 SourceLocation BaseLoc
4382 = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4384 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4385 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4386 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4388 // C++ [class.base.init]p2:
4389 // [...] Unless the mem-initializer-id names a nonstatic data
4390 // member of the constructor's class or a direct or virtual base
4391 // of that class, the mem-initializer is ill-formed. A
4392 // mem-initializer-list can initialize a base class using any
4393 // name that denotes that base class type.
4394 bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4396 SourceRange InitRange = Init->getSourceRange();
4397 if (EllipsisLoc.isValid()) {
4398 // This is a pack expansion.
4399 if (!BaseType->containsUnexpandedParameterPack()) {
4400 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4401 << SourceRange(BaseLoc, InitRange.getEnd());
4403 EllipsisLoc = SourceLocation();
4406 // Check for any unexpanded parameter packs.
4407 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4410 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4414 // Check for direct and virtual base classes.
4415 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4416 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4418 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4420 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4422 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4425 // C++ [base.class.init]p2:
4426 // Unless the mem-initializer-id names a nonstatic data member of the
4427 // constructor's class or a direct or virtual base of that class, the
4428 // mem-initializer is ill-formed.
4429 if (!DirectBaseSpec && !VirtualBaseSpec) {
4430 // If the class has any dependent bases, then it's possible that
4431 // one of those types will resolve to the same type as
4432 // BaseType. Therefore, just treat this as a dependent base
4433 // class initialization. FIXME: Should we try to check the
4434 // initialization anyway? It seems odd.
4435 if (ClassDecl->hasAnyDependentBases())
4438 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4439 << BaseType << Context.getTypeDeclType(ClassDecl)
4440 << BaseTInfo->getTypeLoc().getLocalSourceRange();
4445 DiscardCleanupsInEvaluationContext();
4447 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4448 /*IsVirtual=*/false,
4449 InitRange.getBegin(), Init,
4450 InitRange.getEnd(), EllipsisLoc);
4453 // C++ [base.class.init]p2:
4454 // If a mem-initializer-id is ambiguous because it designates both
4455 // a direct non-virtual base class and an inherited virtual base
4456 // class, the mem-initializer is ill-formed.
4457 if (DirectBaseSpec && VirtualBaseSpec)
4458 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4459 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4461 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4463 BaseSpec = VirtualBaseSpec;
4465 // Initialize the base.
4466 bool InitList = true;
4467 MultiExprArg Args = Init;
4468 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4470 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4473 InitializedEntity BaseEntity =
4474 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4475 InitializationKind Kind =
4476 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4477 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4478 InitRange.getEnd());
4479 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4480 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4481 if (BaseInit.isInvalid())
4484 // C++11 [class.base.init]p7:
4485 // The initialization of each base and member constitutes a
4487 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4488 /*DiscardedValue*/ false);
4489 if (BaseInit.isInvalid())
4492 // If we are in a dependent context, template instantiation will
4493 // perform this type-checking again. Just save the arguments that we
4494 // received in a ParenListExpr.
4495 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4496 // of the information that we have about the base
4497 // initializer. However, deconstructing the ASTs is a dicey process,
4498 // and this approach is far more likely to get the corner cases right.
4499 if (CurContext->isDependentContext())
4502 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4503 BaseSpec->isVirtual(),
4504 InitRange.getBegin(),
4505 BaseInit.getAs<Expr>(),
4506 InitRange.getEnd(), EllipsisLoc);
4509 // Create a static_cast\<T&&>(expr).
4510 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4511 if (T.isNull()) T = E->getType();
4512 QualType TargetType = SemaRef.BuildReferenceType(
4513 T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4514 SourceLocation ExprLoc = E->getBeginLoc();
4515 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4516 TargetType, ExprLoc);
4518 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4519 SourceRange(ExprLoc, ExprLoc),
4520 E->getSourceRange()).get();
4523 /// ImplicitInitializerKind - How an implicit base or member initializer should
4524 /// initialize its base or member.
4525 enum ImplicitInitializerKind {
4533 BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4534 ImplicitInitializerKind ImplicitInitKind,
4535 CXXBaseSpecifier *BaseSpec,
4536 bool IsInheritedVirtualBase,
4537 CXXCtorInitializer *&CXXBaseInit) {
4538 InitializedEntity InitEntity
4539 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4540 IsInheritedVirtualBase);
4542 ExprResult BaseInit;
4544 switch (ImplicitInitKind) {
4547 InitializationKind InitKind
4548 = InitializationKind::CreateDefault(Constructor->getLocation());
4549 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4550 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4556 bool Moving = ImplicitInitKind == IIK_Move;
4557 ParmVarDecl *Param = Constructor->getParamDecl(0);
4558 QualType ParamType = Param->getType().getNonReferenceType();
4561 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4562 SourceLocation(), Param, false,
4563 Constructor->getLocation(), ParamType,
4564 VK_LValue, nullptr);
4566 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4568 // Cast to the base class to avoid ambiguities.
4570 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4571 ParamType.getQualifiers());
4574 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4577 CXXCastPath BasePath;
4578 BasePath.push_back(BaseSpec);
4579 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4580 CK_UncheckedDerivedToBase,
4581 Moving ? VK_XValue : VK_LValue,
4584 InitializationKind InitKind
4585 = InitializationKind::CreateDirect(Constructor->getLocation(),
4586 SourceLocation(), SourceLocation());
4587 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4588 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4593 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4594 if (BaseInit.isInvalid())
4598 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4599 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4601 BaseSpec->isVirtual(),
4603 BaseInit.getAs<Expr>(),
4610 static bool RefersToRValueRef(Expr *MemRef) {
4611 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4612 return Referenced->getType()->isRValueReferenceType();
4616 BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4617 ImplicitInitializerKind ImplicitInitKind,
4618 FieldDecl *Field, IndirectFieldDecl *Indirect,
4619 CXXCtorInitializer *&CXXMemberInit) {
4620 if (Field->isInvalidDecl())
4623 SourceLocation Loc = Constructor->getLocation();
4625 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4626 bool Moving = ImplicitInitKind == IIK_Move;
4627 ParmVarDecl *Param = Constructor->getParamDecl(0);
4628 QualType ParamType = Param->getType().getNonReferenceType();
4630 // Suppress copying zero-width bitfields.
4631 if (Field->isZeroLengthBitField(SemaRef.Context))
4634 Expr *MemberExprBase =
4635 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4636 SourceLocation(), Param, false,
4637 Loc, ParamType, VK_LValue, nullptr);
4639 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4642 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4645 // Build a reference to this field within the parameter.
4647 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4648 Sema::LookupMemberName);
4649 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4650 : cast<ValueDecl>(Field), AS_public);
4651 MemberLookup.resolveKind();
4653 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4657 /*TemplateKWLoc=*/SourceLocation(),
4658 /*FirstQualifierInScope=*/nullptr,
4660 /*TemplateArgs=*/nullptr,
4662 if (CtorArg.isInvalid())
4665 // C++11 [class.copy]p15:
4666 // - if a member m has rvalue reference type T&&, it is direct-initialized
4667 // with static_cast<T&&>(x.m);
4668 if (RefersToRValueRef(CtorArg.get())) {
4669 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4672 InitializedEntity Entity =
4673 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4675 : InitializedEntity::InitializeMember(Field, nullptr,
4678 // Direct-initialize to use the copy constructor.
4679 InitializationKind InitKind =
4680 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4682 Expr *CtorArgE = CtorArg.getAs<Expr>();
4683 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4684 ExprResult MemberInit =
4685 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4686 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4687 if (MemberInit.isInvalid())
4691 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4692 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4694 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4695 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4699 assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4700 "Unhandled implicit init kind!");
4702 QualType FieldBaseElementType =
4703 SemaRef.Context.getBaseElementType(Field->getType());
4705 if (FieldBaseElementType->isRecordType()) {
4706 InitializedEntity InitEntity =
4707 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4709 : InitializedEntity::InitializeMember(Field, nullptr,
4711 InitializationKind InitKind =
4712 InitializationKind::CreateDefault(Loc);
4714 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4715 ExprResult MemberInit =
4716 InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4718 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4719 if (MemberInit.isInvalid())
4723 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4729 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4736 if (!Field->getParent()->isUnion()) {
4737 if (FieldBaseElementType->isReferenceType()) {
4738 SemaRef.Diag(Constructor->getLocation(),
4739 diag::err_uninitialized_member_in_ctor)
4740 << (int)Constructor->isImplicit()
4741 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4742 << 0 << Field->getDeclName();
4743 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4747 if (FieldBaseElementType.isConstQualified()) {
4748 SemaRef.Diag(Constructor->getLocation(),
4749 diag::err_uninitialized_member_in_ctor)
4750 << (int)Constructor->isImplicit()
4751 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4752 << 1 << Field->getDeclName();
4753 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4758 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4760 // Default-initialize Objective-C pointers to NULL.
4762 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4764 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4769 // Nothing to initialize.
4770 CXXMemberInit = nullptr;
4775 struct BaseAndFieldInfo {
4777 CXXConstructorDecl *Ctor;
4778 bool AnyErrorsInInits;
4779 ImplicitInitializerKind IIK;
4780 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4781 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4782 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4784 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4785 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4786 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4787 if (Ctor->getInheritedConstructor())
4789 else if (Generated && Ctor->isCopyConstructor())
4791 else if (Generated && Ctor->isMoveConstructor())
4797 bool isImplicitCopyOrMove() const {
4808 llvm_unreachable("Invalid ImplicitInitializerKind!");
4811 bool addFieldInitializer(CXXCtorInitializer *Init) {
4812 AllToInit.push_back(Init);
4814 // Check whether this initializer makes the field "used".
4815 if (Init->getInit()->HasSideEffects(S.Context))
4816 S.UnusedPrivateFields.remove(Init->getAnyMember());
4821 bool isInactiveUnionMember(FieldDecl *Field) {
4822 RecordDecl *Record = Field->getParent();
4823 if (!Record->isUnion())
4826 if (FieldDecl *Active =
4827 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4828 return Active != Field->getCanonicalDecl();
4830 // In an implicit copy or move constructor, ignore any in-class initializer.
4831 if (isImplicitCopyOrMove())
4834 // If there's no explicit initialization, the field is active only if it
4835 // has an in-class initializer...
4836 if (Field->hasInClassInitializer())
4838 // ... or it's an anonymous struct or union whose class has an in-class
4840 if (!Field->isAnonymousStructOrUnion())
4842 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4843 return !FieldRD->hasInClassInitializer();
4846 /// Determine whether the given field is, or is within, a union member
4847 /// that is inactive (because there was an initializer given for a different
4848 /// member of the union, or because the union was not initialized at all).
4849 bool isWithinInactiveUnionMember(FieldDecl *Field,
4850 IndirectFieldDecl *Indirect) {
4852 return isInactiveUnionMember(Field);
4854 for (auto *C : Indirect->chain()) {
4855 FieldDecl *Field = dyn_cast<FieldDecl>(C);
4856 if (Field && isInactiveUnionMember(Field))
4864 /// Determine whether the given type is an incomplete or zero-lenfgth
4866 static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
4867 if (T->isIncompleteArrayType())
4870 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4871 if (!ArrayT->getSize())
4874 T = ArrayT->getElementType();
4880 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4882 IndirectFieldDecl *Indirect = nullptr) {
4883 if (Field->isInvalidDecl())
4886 // Overwhelmingly common case: we have a direct initializer for this field.
4887 if (CXXCtorInitializer *Init =
4888 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4889 return Info.addFieldInitializer(Init);
4891 // C++11 [class.base.init]p8:
4892 // if the entity is a non-static data member that has a
4893 // brace-or-equal-initializer and either
4894 // -- the constructor's class is a union and no other variant member of that
4895 // union is designated by a mem-initializer-id or
4896 // -- the constructor's class is not a union, and, if the entity is a member
4897 // of an anonymous union, no other member of that union is designated by
4898 // a mem-initializer-id,
4899 // the entity is initialized as specified in [dcl.init].
4901 // We also apply the same rules to handle anonymous structs within anonymous
4903 if (Info.isWithinInactiveUnionMember(Field, Indirect))
4906 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4908 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4909 if (DIE.isInvalid())
4912 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4913 SemaRef.checkInitializerLifetime(Entity, DIE.get());
4915 CXXCtorInitializer *Init;
4917 Init = new (SemaRef.Context)
4918 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4919 SourceLocation(), DIE.get(), SourceLocation());
4921 Init = new (SemaRef.Context)
4922 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4923 SourceLocation(), DIE.get(), SourceLocation());
4924 return Info.addFieldInitializer(Init);
4927 // Don't initialize incomplete or zero-length arrays.
4928 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4931 // Don't try to build an implicit initializer if there were semantic
4932 // errors in any of the initializers (and therefore we might be
4933 // missing some that the user actually wrote).
4934 if (Info.AnyErrorsInInits)
4937 CXXCtorInitializer *Init = nullptr;
4938 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4945 return Info.addFieldInitializer(Init);
4949 Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
4950 CXXCtorInitializer *Initializer) {
4951 assert(Initializer->isDelegatingInitializer());
4952 Constructor->setNumCtorInitializers(1);
4953 CXXCtorInitializer **initializer =
4954 new (Context) CXXCtorInitializer*[1];
4955 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4956 Constructor->setCtorInitializers(initializer);
4958 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4959 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4960 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4963 DelegatingCtorDecls.push_back(Constructor);
4965 DiagnoseUninitializedFields(*this, Constructor);
4970 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4971 ArrayRef<CXXCtorInitializer *> Initializers) {
4972 if (Constructor->isDependentContext()) {
4973 // Just store the initializers as written, they will be checked during
4975 if (!Initializers.empty()) {
4976 Constructor->setNumCtorInitializers(Initializers.size());
4977 CXXCtorInitializer **baseOrMemberInitializers =
4978 new (Context) CXXCtorInitializer*[Initializers.size()];
4979 memcpy(baseOrMemberInitializers, Initializers.data(),
4980 Initializers.size() * sizeof(CXXCtorInitializer*));
4981 Constructor->setCtorInitializers(baseOrMemberInitializers);
4984 // Let template instantiation know whether we had errors.
4986 Constructor->setInvalidDecl();
4991 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4993 // We need to build the initializer AST according to order of construction
4994 // and not what user specified in the Initializers list.
4995 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4999 bool HadError = false;
5001 for (unsigned i = 0; i < Initializers.size(); i++) {
5002 CXXCtorInitializer *Member = Initializers[i];
5004 if (Member->isBaseInitializer())
5005 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
5007 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
5009 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
5010 for (auto *C : F->chain()) {
5011 FieldDecl *FD = dyn_cast<FieldDecl>(C);
5012 if (FD && FD->getParent()->isUnion())
5013 Info.ActiveUnionMember.insert(std::make_pair(
5014 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5016 } else if (FieldDecl *FD = Member->getMember()) {
5017 if (FD->getParent()->isUnion())
5018 Info.ActiveUnionMember.insert(std::make_pair(
5019 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
5024 // Keep track of the direct virtual bases.
5025 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
5026 for (auto &I : ClassDecl->bases()) {
5028 DirectVBases.insert(&I);
5031 // Push virtual bases before others.
5032 for (auto &VBase : ClassDecl->vbases()) {
5033 if (CXXCtorInitializer *Value
5034 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5035 // [class.base.init]p7, per DR257:
5036 // A mem-initializer where the mem-initializer-id names a virtual base
5037 // class is ignored during execution of a constructor of any class that
5038 // is not the most derived class.
5039 if (ClassDecl->isAbstract()) {
5040 // FIXME: Provide a fixit to remove the base specifier. This requires
5041 // tracking the location of the associated comma for a base specifier.
5042 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5043 << VBase.getType() << ClassDecl;
5044 DiagnoseAbstractType(ClassDecl);
5047 Info.AllToInit.push_back(Value);
5048 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5049 // [class.base.init]p8, per DR257:
5050 // If a given [...] base class is not named by a mem-initializer-id
5051 // [...] and the entity is not a virtual base class of an abstract
5052 // class, then [...] the entity is default-initialized.
5053 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5054 CXXCtorInitializer *CXXBaseInit;
5055 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5056 &VBase, IsInheritedVirtualBase,
5062 Info.AllToInit.push_back(CXXBaseInit);
5066 // Non-virtual bases.
5067 for (auto &Base : ClassDecl->bases()) {
5068 // Virtuals are in the virtual base list and already constructed.
5069 if (Base.isVirtual())
5072 if (CXXCtorInitializer *Value
5073 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5074 Info.AllToInit.push_back(Value);
5075 } else if (!AnyErrors) {
5076 CXXCtorInitializer *CXXBaseInit;
5077 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5078 &Base, /*IsInheritedVirtualBase=*/false,
5084 Info.AllToInit.push_back(CXXBaseInit);
5089 for (auto *Mem : ClassDecl->decls()) {
5090 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5091 // C++ [class.bit]p2:
5092 // A declaration for a bit-field that omits the identifier declares an
5093 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5095 if (F->isUnnamedBitfield())
5098 // If we're not generating the implicit copy/move constructor, then we'll
5099 // handle anonymous struct/union fields based on their individual
5101 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5104 if (CollectFieldInitializer(*this, Info, F))
5109 // Beyond this point, we only consider default initialization.
5110 if (Info.isImplicitCopyOrMove())
5113 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5114 if (F->getType()->isIncompleteArrayType()) {
5115 assert(ClassDecl->hasFlexibleArrayMember() &&
5116 "Incomplete array type is not valid");
5120 // Initialize each field of an anonymous struct individually.
5121 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5128 unsigned NumInitializers = Info.AllToInit.size();
5129 if (NumInitializers > 0) {
5130 Constructor->setNumCtorInitializers(NumInitializers);
5131 CXXCtorInitializer **baseOrMemberInitializers =
5132 new (Context) CXXCtorInitializer*[NumInitializers];
5133 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5134 NumInitializers * sizeof(CXXCtorInitializer*));
5135 Constructor->setCtorInitializers(baseOrMemberInitializers);
5137 // Constructors implicitly reference the base and member
5139 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5140 Constructor->getParent());
5146 static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5147 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5148 const RecordDecl *RD = RT->getDecl();
5149 if (RD->isAnonymousStructOrUnion()) {
5150 for (auto *Field : RD->fields())
5151 PopulateKeysForFields(Field, IdealInits);
5155 IdealInits.push_back(Field->getCanonicalDecl());
5158 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5159 return Context.getCanonicalType(BaseType).getTypePtr();
5162 static const void *GetKeyForMember(ASTContext &Context,
5163 CXXCtorInitializer *Member) {
5164 if (!Member->isAnyMemberInitializer())
5165 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5167 return Member->getAnyMember()->getCanonicalDecl();
5170 static void DiagnoseBaseOrMemInitializerOrder(
5171 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5172 ArrayRef<CXXCtorInitializer *> Inits) {
5173 if (Constructor->getDeclContext()->isDependentContext())
5176 // Don't check initializers order unless the warning is enabled at the
5177 // location of at least one initializer.
5178 bool ShouldCheckOrder = false;
5179 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5180 CXXCtorInitializer *Init = Inits[InitIndex];
5181 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5182 Init->getSourceLocation())) {
5183 ShouldCheckOrder = true;
5187 if (!ShouldCheckOrder)
5190 // Build the list of bases and members in the order that they'll
5191 // actually be initialized. The explicit initializers should be in
5192 // this same order but may be missing things.
5193 SmallVector<const void*, 32> IdealInitKeys;
5195 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5197 // 1. Virtual bases.
5198 for (const auto &VBase : ClassDecl->vbases())
5199 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5201 // 2. Non-virtual bases.
5202 for (const auto &Base : ClassDecl->bases()) {
5203 if (Base.isVirtual())
5205 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5208 // 3. Direct fields.
5209 for (auto *Field : ClassDecl->fields()) {
5210 if (Field->isUnnamedBitfield())
5213 PopulateKeysForFields(Field, IdealInitKeys);
5216 unsigned NumIdealInits = IdealInitKeys.size();
5217 unsigned IdealIndex = 0;
5219 CXXCtorInitializer *PrevInit = nullptr;
5220 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5221 CXXCtorInitializer *Init = Inits[InitIndex];
5222 const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
5224 // Scan forward to try to find this initializer in the idealized
5225 // initializers list.
5226 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5227 if (InitKey == IdealInitKeys[IdealIndex])
5230 // If we didn't find this initializer, it must be because we
5231 // scanned past it on a previous iteration. That can only
5232 // happen if we're out of order; emit a warning.
5233 if (IdealIndex == NumIdealInits && PrevInit) {
5234 Sema::SemaDiagnosticBuilder D =
5235 SemaRef.Diag(PrevInit->getSourceLocation(),
5236 diag::warn_initializer_out_of_order);
5238 if (PrevInit->isAnyMemberInitializer())
5239 D << 0 << PrevInit->getAnyMember()->getDeclName();
5241 D << 1 << PrevInit->getTypeSourceInfo()->getType();
5243 if (Init->isAnyMemberInitializer())
5244 D << 0 << Init->getAnyMember()->getDeclName();
5246 D << 1 << Init->getTypeSourceInfo()->getType();
5248 // Move back to the initializer's location in the ideal list.
5249 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5250 if (InitKey == IdealInitKeys[IdealIndex])
5253 assert(IdealIndex < NumIdealInits &&
5254 "initializer not found in initializer list");
5262 bool CheckRedundantInit(Sema &S,
5263 CXXCtorInitializer *Init,
5264 CXXCtorInitializer *&PrevInit) {
5270 if (FieldDecl *Field = Init->getAnyMember())
5271 S.Diag(Init->getSourceLocation(),
5272 diag::err_multiple_mem_initialization)
5273 << Field->getDeclName()
5274 << Init->getSourceRange();
5276 const Type *BaseClass = Init->getBaseClass();
5277 assert(BaseClass && "neither field nor base");
5278 S.Diag(Init->getSourceLocation(),
5279 diag::err_multiple_base_initialization)
5280 << QualType(BaseClass, 0)
5281 << Init->getSourceRange();
5283 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5284 << 0 << PrevInit->getSourceRange();
5289 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5290 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5292 bool CheckRedundantUnionInit(Sema &S,
5293 CXXCtorInitializer *Init,
5294 RedundantUnionMap &Unions) {
5295 FieldDecl *Field = Init->getAnyMember();
5296 RecordDecl *Parent = Field->getParent();
5297 NamedDecl *Child = Field;
5299 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5300 if (Parent->isUnion()) {
5301 UnionEntry &En = Unions[Parent];
5302 if (En.first && En.first != Child) {
5303 S.Diag(Init->getSourceLocation(),
5304 diag::err_multiple_mem_union_initialization)
5305 << Field->getDeclName()
5306 << Init->getSourceRange();
5307 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5308 << 0 << En.second->getSourceRange();
5315 if (!Parent->isAnonymousStructOrUnion())
5320 Parent = cast<RecordDecl>(Parent->getDeclContext());
5327 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5328 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5329 SourceLocation ColonLoc,
5330 ArrayRef<CXXCtorInitializer*> MemInits,
5332 if (!ConstructorDecl)
5335 AdjustDeclIfTemplate(ConstructorDecl);
5337 CXXConstructorDecl *Constructor
5338 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5341 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5345 // Mapping for the duplicate initializers check.
5346 // For member initializers, this is keyed with a FieldDecl*.
5347 // For base initializers, this is keyed with a Type*.
5348 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5350 // Mapping for the inconsistent anonymous-union initializers check.
5351 RedundantUnionMap MemberUnions;
5353 bool HadError = false;
5354 for (unsigned i = 0; i < MemInits.size(); i++) {
5355 CXXCtorInitializer *Init = MemInits[i];
5357 // Set the source order index.
5358 Init->setSourceOrder(i);
5360 if (Init->isAnyMemberInitializer()) {
5361 const void *Key = GetKeyForMember(Context, Init);
5362 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5363 CheckRedundantUnionInit(*this, Init, MemberUnions))
5365 } else if (Init->isBaseInitializer()) {
5366 const void *Key = GetKeyForMember(Context, Init);
5367 if (CheckRedundantInit(*this, Init, Members[Key]))
5370 assert(Init->isDelegatingInitializer());
5371 // This must be the only initializer
5372 if (MemInits.size() != 1) {
5373 Diag(Init->getSourceLocation(),
5374 diag::err_delegating_initializer_alone)
5375 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5376 // We will treat this as being the only initializer.
5378 SetDelegatingInitializer(Constructor, MemInits[i]);
5379 // Return immediately as the initializer is set.
5387 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5389 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5391 DiagnoseUninitializedFields(*this, Constructor);
5395 Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5396 CXXRecordDecl *ClassDecl) {
5397 // Ignore dependent contexts. Also ignore unions, since their members never
5398 // have destructors implicitly called.
5399 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5402 // FIXME: all the access-control diagnostics are positioned on the
5403 // field/base declaration. That's probably good; that said, the
5404 // user might reasonably want to know why the destructor is being
5405 // emitted, and we currently don't say.
5407 // Non-static data members.
5408 for (auto *Field : ClassDecl->fields()) {
5409 if (Field->isInvalidDecl())
5412 // Don't destroy incomplete or zero-length arrays.
5413 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5416 QualType FieldType = Context.getBaseElementType(Field->getType());
5418 const RecordType* RT = FieldType->getAs<RecordType>();
5422 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5423 if (FieldClassDecl->isInvalidDecl())
5425 if (FieldClassDecl->hasIrrelevantDestructor())
5427 // The destructor for an implicit anonymous union member is never invoked.
5428 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5431 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5432 assert(Dtor && "No dtor found for FieldClassDecl!");
5433 CheckDestructorAccess(Field->getLocation(), Dtor,
5434 PDiag(diag::err_access_dtor_field)
5435 << Field->getDeclName()
5438 MarkFunctionReferenced(Location, Dtor);
5439 DiagnoseUseOfDecl(Dtor, Location);
5442 // We only potentially invoke the destructors of potentially constructed
5444 bool VisitVirtualBases = !ClassDecl->isAbstract();
5446 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5449 for (const auto &Base : ClassDecl->bases()) {
5450 // Bases are always records in a well-formed non-dependent class.
5451 const RecordType *RT = Base.getType()->getAs<RecordType>();
5453 // Remember direct virtual bases.
5454 if (Base.isVirtual()) {
5455 if (!VisitVirtualBases)
5457 DirectVirtualBases.insert(RT);
5460 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5461 // If our base class is invalid, we probably can't get its dtor anyway.
5462 if (BaseClassDecl->isInvalidDecl())
5464 if (BaseClassDecl->hasIrrelevantDestructor())
5467 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5468 assert(Dtor && "No dtor found for BaseClassDecl!");
5470 // FIXME: caret should be on the start of the class name
5471 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5472 PDiag(diag::err_access_dtor_base)
5473 << Base.getType() << Base.getSourceRange(),
5474 Context.getTypeDeclType(ClassDecl));
5476 MarkFunctionReferenced(Location, Dtor);
5477 DiagnoseUseOfDecl(Dtor, Location);
5480 if (!VisitVirtualBases)
5484 for (const auto &VBase : ClassDecl->vbases()) {
5485 // Bases are always records in a well-formed non-dependent class.
5486 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5488 // Ignore direct virtual bases.
5489 if (DirectVirtualBases.count(RT))
5492 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5493 // If our base class is invalid, we probably can't get its dtor anyway.
5494 if (BaseClassDecl->isInvalidDecl())
5496 if (BaseClassDecl->hasIrrelevantDestructor())
5499 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5500 assert(Dtor && "No dtor found for BaseClassDecl!");
5501 if (CheckDestructorAccess(
5502 ClassDecl->getLocation(), Dtor,
5503 PDiag(diag::err_access_dtor_vbase)
5504 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5505 Context.getTypeDeclType(ClassDecl)) ==
5507 CheckDerivedToBaseConversion(
5508 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5509 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5510 SourceRange(), DeclarationName(), nullptr);
5513 MarkFunctionReferenced(Location, Dtor);
5514 DiagnoseUseOfDecl(Dtor, Location);
5518 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5522 if (CXXConstructorDecl *Constructor
5523 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5524 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5525 DiagnoseUninitializedFields(*this, Constructor);
5529 bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5530 if (!getLangOpts().CPlusPlus)
5533 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5537 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5538 // class template specialization here, but doing so breaks a lot of code.
5540 // We can't answer whether something is abstract until it has a
5541 // definition. If it's currently being defined, we'll walk back
5542 // over all the declarations when we have a full definition.
5543 const CXXRecordDecl *Def = RD->getDefinition();
5544 if (!Def || Def->isBeingDefined())
5547 return RD->isAbstract();
5550 bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5551 TypeDiagnoser &Diagnoser) {
5552 if (!isAbstractType(Loc, T))
5555 T = Context.getBaseElementType(T);
5556 Diagnoser.diagnose(*this, Loc, T);
5557 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5561 void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5562 // Check if we've already emitted the list of pure virtual functions
5564 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5567 // If the diagnostic is suppressed, don't emit the notes. We're only
5568 // going to emit them once, so try to attach them to a diagnostic we're
5569 // actually going to show.
5570 if (Diags.isLastDiagnosticIgnored())
5573 CXXFinalOverriderMap FinalOverriders;
5574 RD->getFinalOverriders(FinalOverriders);
5576 // Keep a set of seen pure methods so we won't diagnose the same method
5578 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5580 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5581 MEnd = FinalOverriders.end();
5584 for (OverridingMethods::iterator SO = M->second.begin(),
5585 SOEnd = M->second.end();
5586 SO != SOEnd; ++SO) {
5587 // C++ [class.abstract]p4:
5588 // A class is abstract if it contains or inherits at least one
5589 // pure virtual function for which the final overrider is pure
5593 if (SO->second.size() != 1)
5596 if (!SO->second.front().Method->isPure())
5599 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5602 Diag(SO->second.front().Method->getLocation(),
5603 diag::note_pure_virtual_function)
5604 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5608 if (!PureVirtualClassDiagSet)
5609 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5610 PureVirtualClassDiagSet->insert(RD);
5614 struct AbstractUsageInfo {
5616 CXXRecordDecl *Record;
5617 CanQualType AbstractType;
5620 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5621 : S(S), Record(Record),
5622 AbstractType(S.Context.getCanonicalType(
5623 S.Context.getTypeDeclType(Record))),
5626 void DiagnoseAbstractType() {
5627 if (Invalid) return;
5628 S.DiagnoseAbstractType(Record);
5632 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5635 struct CheckAbstractUsage {
5636 AbstractUsageInfo &Info;
5637 const NamedDecl *Ctx;
5639 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5640 : Info(Info), Ctx(Ctx) {}
5642 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5643 switch (TL.getTypeLocClass()) {
5644 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5645 #define TYPELOC(CLASS, PARENT) \
5646 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5647 #include "clang/AST/TypeLocNodes.def"
5651 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5652 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5653 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5654 if (!TL.getParam(I))
5657 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5658 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5662 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5663 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5666 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5667 // Visit the type parameters from a permissive context.
5668 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5669 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5670 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5671 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5672 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5673 // TODO: other template argument types?
5677 // Visit pointee types from a permissive context.
5678 #define CheckPolymorphic(Type) \
5679 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5680 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5682 CheckPolymorphic(PointerTypeLoc)
5683 CheckPolymorphic(ReferenceTypeLoc)
5684 CheckPolymorphic(MemberPointerTypeLoc)
5685 CheckPolymorphic(BlockPointerTypeLoc)
5686 CheckPolymorphic(AtomicTypeLoc)
5688 /// Handle all the types we haven't given a more specific
5689 /// implementation for above.
5690 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5691 // Every other kind of type that we haven't called out already
5692 // that has an inner type is either (1) sugar or (2) contains that
5693 // inner type in some way as a subobject.
5694 if (TypeLoc Next = TL.getNextTypeLoc())
5695 return Visit(Next, Sel);
5697 // If there's no inner type and we're in a permissive context,
5699 if (Sel == Sema::AbstractNone) return;
5701 // Check whether the type matches the abstract type.
5702 QualType T = TL.getType();
5703 if (T->isArrayType()) {
5704 Sel = Sema::AbstractArrayType;
5705 T = Info.S.Context.getBaseElementType(T);
5707 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5708 if (CT != Info.AbstractType) return;
5710 // It matched; do some magic.
5711 if (Sel == Sema::AbstractArrayType) {
5712 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5713 << T << TL.getSourceRange();
5715 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5716 << Sel << T << TL.getSourceRange();
5718 Info.DiagnoseAbstractType();
5722 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5723 Sema::AbstractDiagSelID Sel) {
5724 CheckAbstractUsage(*this, D).Visit(TL, Sel);
5729 /// Check for invalid uses of an abstract type in a method declaration.
5730 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5731 CXXMethodDecl *MD) {
5732 // No need to do the check on definitions, which require that
5733 // the return/param types be complete.
5734 if (MD->doesThisDeclarationHaveABody())
5737 // For safety's sake, just ignore it if we don't have type source
5738 // information. This should never happen for non-implicit methods,
5740 if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5741 Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5744 /// Check for invalid uses of an abstract type within a class definition.
5745 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5746 CXXRecordDecl *RD) {
5747 for (auto *D : RD->decls()) {
5748 if (D->isImplicit()) continue;
5750 // Methods and method templates.
5751 if (isa<CXXMethodDecl>(D)) {
5752 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5753 } else if (isa<FunctionTemplateDecl>(D)) {
5754 FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5755 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5757 // Fields and static variables.
5758 } else if (isa<FieldDecl>(D)) {
5759 FieldDecl *FD = cast<FieldDecl>(D);
5760 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5761 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5762 } else if (isa<VarDecl>(D)) {
5763 VarDecl *VD = cast<VarDecl>(D);
5764 if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5765 Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5767 // Nested classes and class templates.
5768 } else if (isa<CXXRecordDecl>(D)) {
5769 CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5770 } else if (isa<ClassTemplateDecl>(D)) {
5771 CheckAbstractClassUsage(Info,
5772 cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5777 static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
5778 Attr *ClassAttr = getDLLAttr(Class);
5782 assert(ClassAttr->getKind() == attr::DLLExport);
5784 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5786 if (TSK == TSK_ExplicitInstantiationDeclaration)
5787 // Don't go any further if this is just an explicit instantiation
5791 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
5792 S.MarkVTableUsed(Class->getLocation(), Class, true);
5794 for (Decl *Member : Class->decls()) {
5795 // Defined static variables that are members of an exported base
5796 // class must be marked export too.
5797 auto *VD = dyn_cast<VarDecl>(Member);
5798 if (VD && Member->getAttr<DLLExportAttr>() &&
5799 VD->getStorageClass() == SC_Static &&
5800 TSK == TSK_ImplicitInstantiation)
5801 S.MarkVariableReferenced(VD->getLocation(), VD);
5803 auto *MD = dyn_cast<CXXMethodDecl>(Member);
5807 if (Member->getAttr<DLLExportAttr>()) {
5808 if (MD->isUserProvided()) {
5809 // Instantiate non-default class member functions ...
5811 // .. except for certain kinds of template specializations.
5812 if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5815 S.MarkFunctionReferenced(Class->getLocation(), MD);
5817 // The function will be passed to the consumer when its definition is
5819 } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5820 MD->isCopyAssignmentOperator() ||
5821 MD->isMoveAssignmentOperator()) {
5822 // Synthesize and instantiate non-trivial implicit methods, explicitly
5823 // defaulted methods, and the copy and move assignment operators. The
5824 // latter are exported even if they are trivial, because the address of
5825 // an operator can be taken and should compare equal across libraries.
5826 DiagnosticErrorTrap Trap(S.Diags);
5827 S.MarkFunctionReferenced(Class->getLocation(), MD);
5828 if (Trap.hasErrorOccurred()) {
5829 S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5830 << Class << !S.getLangOpts().CPlusPlus11;
5834 // There is no later point when we will see the definition of this
5835 // function, so pass it to the consumer now.
5836 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
5842 static void checkForMultipleExportedDefaultConstructors(Sema &S,
5843 CXXRecordDecl *Class) {
5844 // Only the MS ABI has default constructor closures, so we don't need to do
5845 // this semantic checking anywhere else.
5846 if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
5849 CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5850 for (Decl *Member : Class->decls()) {
5851 // Look for exported default constructors.
5852 auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5853 if (!CD || !CD->isDefaultConstructor())
5855 auto *Attr = CD->getAttr<DLLExportAttr>();
5859 // If the class is non-dependent, mark the default arguments as ODR-used so
5860 // that we can properly codegen the constructor closure.
5861 if (!Class->isDependentContext()) {
5862 for (ParmVarDecl *PD : CD->parameters()) {
5863 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5864 S.DiscardCleanupsInEvaluationContext();
5868 if (LastExportedDefaultCtor) {
5869 S.Diag(LastExportedDefaultCtor->getLocation(),
5870 diag::err_attribute_dll_ambiguous_default_ctor)
5872 S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5873 << CD->getDeclName();
5876 LastExportedDefaultCtor = CD;
5880 void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
5881 // Mark any compiler-generated routines with the implicit code_seg attribute.
5882 for (auto *Method : Class->methods()) {
5883 if (Method->isUserProvided())
5885 if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
5890 /// Check class-level dllimport/dllexport attribute.
5891 void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
5892 Attr *ClassAttr = getDLLAttr(Class);
5894 // MSVC inherits DLL attributes to partial class template specializations.
5895 if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5896 if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5897 if (Attr *TemplateAttr =
5898 getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5899 auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5900 A->setInherited(true);
5909 if (!Class->isExternallyVisible()) {
5910 Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5911 << Class << ClassAttr;
5915 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5916 !ClassAttr->isInherited()) {
5917 // Diagnose dll attributes on members of class with dll attribute.
5918 for (Decl *Member : Class->decls()) {
5919 if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5921 InheritableAttr *MemberAttr = getDLLAttr(Member);
5922 if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5925 Diag(MemberAttr->getLocation(),
5926 diag::err_attribute_dll_member_of_dll_class)
5927 << MemberAttr << ClassAttr;
5928 Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5929 Member->setInvalidDecl();
5933 if (Class->getDescribedClassTemplate())
5934 // Don't inherit dll attribute until the template is instantiated.
5937 // The class is either imported or exported.
5938 const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5940 // Check if this was a dllimport attribute propagated from a derived class to
5941 // a base class template specialization. We don't apply these attributes to
5942 // static data members.
5943 const bool PropagatedImport =
5945 cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
5947 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5949 // Ignore explicit dllexport on explicit class template instantiation
5950 // declarations, except in MinGW mode.
5951 if (ClassExported && !ClassAttr->isInherited() &&
5952 TSK == TSK_ExplicitInstantiationDeclaration &&
5953 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
5954 Class->dropAttr<DLLExportAttr>();
5958 // Force declaration of implicit members so they can inherit the attribute.
5959 ForceDeclarationOfImplicitMembers(Class);
5961 // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
5962 // seem to be true in practice?
5964 for (Decl *Member : Class->decls()) {
5965 VarDecl *VD = dyn_cast<VarDecl>(Member);
5966 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
5968 // Only methods and static fields inherit the attributes.
5973 // Don't process deleted methods.
5974 if (MD->isDeleted())
5977 if (MD->isInlined()) {
5978 // MinGW does not import or export inline methods. But do it for
5979 // template instantiations.
5980 if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5981 !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment() &&
5982 TSK != TSK_ExplicitInstantiationDeclaration &&
5983 TSK != TSK_ExplicitInstantiationDefinition)
5986 // MSVC versions before 2015 don't export the move assignment operators
5987 // and move constructor, so don't attempt to import/export them if
5988 // we have a definition.
5989 auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
5990 if ((MD->isMoveAssignmentOperator() ||
5991 (Ctor && Ctor->isMoveConstructor())) &&
5992 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
5995 // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
5996 // operator is exported anyway.
5997 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
5998 (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
6003 // Don't apply dllimport attributes to static data members of class template
6004 // instantiations when the attribute is propagated from a derived class.
6005 if (VD && PropagatedImport)
6008 if (!cast<NamedDecl>(Member)->isExternallyVisible())
6011 if (!getDLLAttr(Member)) {
6012 InheritableAttr *NewAttr = nullptr;
6014 // Do not export/import inline function when -fno-dllexport-inlines is
6015 // passed. But add attribute for later local static var check.
6016 if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
6017 TSK != TSK_ExplicitInstantiationDeclaration &&
6018 TSK != TSK_ExplicitInstantiationDefinition) {
6019 if (ClassExported) {
6020 NewAttr = ::new (getASTContext())
6021 DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
6023 NewAttr = ::new (getASTContext())
6024 DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
6027 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6030 NewAttr->setInherited(true);
6031 Member->addAttr(NewAttr);
6034 // Propagate DLLAttr to friend re-declarations of MD that have already
6035 // been constructed.
6036 for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
6037 FD = FD->getPreviousDecl()) {
6038 if (FD->getFriendObjectKind() == Decl::FOK_None)
6040 assert(!getDLLAttr(FD) &&
6041 "friend re-decl should not already have a DLLAttr");
6042 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6043 NewAttr->setInherited(true);
6044 FD->addAttr(NewAttr);
6051 DelayedDllExportClasses.push_back(Class);
6054 /// Perform propagation of DLL attributes from a derived class to a
6055 /// templated base class for MS compatibility.
6056 void Sema::propagateDLLAttrToBaseClassTemplate(
6057 CXXRecordDecl *Class, Attr *ClassAttr,
6058 ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
6060 BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
6061 // If the base class template has a DLL attribute, don't try to change it.
6065 auto TSK = BaseTemplateSpec->getSpecializationKind();
6066 if (!getDLLAttr(BaseTemplateSpec) &&
6067 (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
6068 TSK == TSK_ImplicitInstantiation)) {
6069 // The template hasn't been instantiated yet (or it has, but only as an
6070 // explicit instantiation declaration or implicit instantiation, which means
6071 // we haven't codegenned any members yet), so propagate the attribute.
6072 auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6073 NewAttr->setInherited(true);
6074 BaseTemplateSpec->addAttr(NewAttr);
6076 // If this was an import, mark that we propagated it from a derived class to
6077 // a base class template specialization.
6078 if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
6079 ImportAttr->setPropagatedToBaseTemplate();
6081 // If the template is already instantiated, checkDLLAttributeRedeclaration()
6082 // needs to be run again to work see the new attribute. Otherwise this will
6083 // get run whenever the template is instantiated.
6084 if (TSK != TSK_Undeclared)
6085 checkClassLevelDLLAttribute(BaseTemplateSpec);
6090 if (getDLLAttr(BaseTemplateSpec)) {
6091 // The template has already been specialized or instantiated with an
6092 // attribute, explicitly or through propagation. We should not try to change
6097 // The template was previously instantiated or explicitly specialized without
6098 // a dll attribute, It's too late for us to add an attribute, so warn that
6099 // this is unsupported.
6100 Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
6101 << BaseTemplateSpec->isExplicitSpecialization();
6102 Diag(ClassAttr->getLocation(), diag::note_attribute);
6103 if (BaseTemplateSpec->isExplicitSpecialization()) {
6104 Diag(BaseTemplateSpec->getLocation(),
6105 diag::note_template_class_explicit_specialization_was_here)
6106 << BaseTemplateSpec;
6108 Diag(BaseTemplateSpec->getPointOfInstantiation(),
6109 diag::note_template_class_instantiation_was_here)
6110 << BaseTemplateSpec;
6114 /// Determine the kind of defaulting that would be done for a given function.
6116 /// If the function is both a default constructor and a copy / move constructor
6117 /// (due to having a default argument for the first parameter), this picks
6118 /// CXXDefaultConstructor.
6120 /// FIXME: Check that case is properly handled by all callers.
6121 Sema::DefaultedFunctionKind
6122 Sema::getDefaultedFunctionKind(const FunctionDecl *FD) {
6123 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
6124 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
6125 if (Ctor->isDefaultConstructor())
6126 return Sema::CXXDefaultConstructor;
6128 if (Ctor->isCopyConstructor())
6129 return Sema::CXXCopyConstructor;
6131 if (Ctor->isMoveConstructor())
6132 return Sema::CXXMoveConstructor;
6135 if (MD->isCopyAssignmentOperator())
6136 return Sema::CXXCopyAssignment;
6138 if (MD->isMoveAssignmentOperator())
6139 return Sema::CXXMoveAssignment;
6141 if (isa<CXXDestructorDecl>(FD))
6142 return Sema::CXXDestructor;
6145 switch (FD->getDeclName().getCXXOverloadedOperator()) {
6147 return DefaultedComparisonKind::Equal;
6149 case OO_ExclaimEqual:
6150 return DefaultedComparisonKind::NotEqual;
6153 // No point allowing this if <=> doesn't exist in the current language mode.
6154 if (!getLangOpts().CPlusPlus2a)
6156 return DefaultedComparisonKind::ThreeWay;
6161 case OO_GreaterEqual:
6162 // No point allowing this if <=> doesn't exist in the current language mode.
6163 if (!getLangOpts().CPlusPlus2a)
6165 return DefaultedComparisonKind::Relational;
6172 return DefaultedFunctionKind();
6175 static void DefineImplicitSpecialMember(Sema &S, CXXMethodDecl *MD,
6176 SourceLocation DefaultLoc) {
6177 switch (S.getSpecialMember(MD)) {
6178 case Sema::CXXDefaultConstructor:
6179 S.DefineImplicitDefaultConstructor(DefaultLoc,
6180 cast<CXXConstructorDecl>(MD));
6182 case Sema::CXXCopyConstructor:
6183 S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
6185 case Sema::CXXCopyAssignment:
6186 S.DefineImplicitCopyAssignment(DefaultLoc, MD);
6188 case Sema::CXXDestructor:
6189 S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(MD));
6191 case Sema::CXXMoveConstructor:
6192 S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
6194 case Sema::CXXMoveAssignment:
6195 S.DefineImplicitMoveAssignment(DefaultLoc, MD);
6197 case Sema::CXXInvalid:
6198 llvm_unreachable("Invalid special member.");
6202 /// Determine whether a type is permitted to be passed or returned in
6203 /// registers, per C++ [class.temporary]p3.
6204 static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
6205 TargetInfo::CallingConvKind CCK) {
6206 if (D->isDependentType() || D->isInvalidDecl())
6209 // Clang <= 4 used the pre-C++11 rule, which ignores move operations.
6210 // The PS4 platform ABI follows the behavior of Clang 3.2.
6211 if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
6212 return !D->hasNonTrivialDestructorForCall() &&
6213 !D->hasNonTrivialCopyConstructorForCall();
6215 if (CCK == TargetInfo::CCK_MicrosoftWin64) {
6216 bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
6217 bool DtorIsTrivialForCall = false;
6219 // If a class has at least one non-deleted, trivial copy constructor, it
6220 // is passed according to the C ABI. Otherwise, it is passed indirectly.
6222 // Note: This permits classes with non-trivial copy or move ctors to be
6223 // passed in registers, so long as they *also* have a trivial copy ctor,
6224 // which is non-conforming.
6225 if (D->needsImplicitCopyConstructor()) {
6226 if (!D->defaultedCopyConstructorIsDeleted()) {
6227 if (D->hasTrivialCopyConstructor())
6228 CopyCtorIsTrivial = true;
6229 if (D->hasTrivialCopyConstructorForCall())
6230 CopyCtorIsTrivialForCall = true;
6233 for (const CXXConstructorDecl *CD : D->ctors()) {
6234 if (CD->isCopyConstructor() && !CD->isDeleted()) {
6235 if (CD->isTrivial())
6236 CopyCtorIsTrivial = true;
6237 if (CD->isTrivialForCall())
6238 CopyCtorIsTrivialForCall = true;
6243 if (D->needsImplicitDestructor()) {
6244 if (!D->defaultedDestructorIsDeleted() &&
6245 D->hasTrivialDestructorForCall())
6246 DtorIsTrivialForCall = true;
6247 } else if (const auto *DD = D->getDestructor()) {
6248 if (!DD->isDeleted() && DD->isTrivialForCall())
6249 DtorIsTrivialForCall = true;
6252 // If the copy ctor and dtor are both trivial-for-calls, pass direct.
6253 if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
6256 // If a class has a destructor, we'd really like to pass it indirectly
6257 // because it allows us to elide copies. Unfortunately, MSVC makes that
6258 // impossible for small types, which it will pass in a single register or
6259 // stack slot. Most objects with dtors are large-ish, so handle that early.
6260 // We can't call out all large objects as being indirect because there are
6261 // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
6262 // how we pass large POD types.
6264 // Note: This permits small classes with nontrivial destructors to be
6265 // passed in registers, which is non-conforming.
6266 bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
6267 uint64_t TypeSize = isAArch64 ? 128 : 64;
6269 if (CopyCtorIsTrivial &&
6270 S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
6275 // Per C++ [class.temporary]p3, the relevant condition is:
6276 // each copy constructor, move constructor, and destructor of X is
6277 // either trivial or deleted, and X has at least one non-deleted copy
6278 // or move constructor
6279 bool HasNonDeletedCopyOrMove = false;
6281 if (D->needsImplicitCopyConstructor() &&
6282 !D->defaultedCopyConstructorIsDeleted()) {
6283 if (!D->hasTrivialCopyConstructorForCall())
6285 HasNonDeletedCopyOrMove = true;
6288 if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
6289 !D->defaultedMoveConstructorIsDeleted()) {
6290 if (!D->hasTrivialMoveConstructorForCall())
6292 HasNonDeletedCopyOrMove = true;
6295 if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
6296 !D->hasTrivialDestructorForCall())
6299 for (const CXXMethodDecl *MD : D->methods()) {
6300 if (MD->isDeleted())
6303 auto *CD = dyn_cast<CXXConstructorDecl>(MD);
6304 if (CD && CD->isCopyOrMoveConstructor())
6305 HasNonDeletedCopyOrMove = true;
6306 else if (!isa<CXXDestructorDecl>(MD))
6309 if (!MD->isTrivialForCall())
6313 return HasNonDeletedCopyOrMove;
6316 /// Perform semantic checks on a class definition that has been
6317 /// completing, introducing implicitly-declared members, checking for
6318 /// abstract types, etc.
6320 /// \param S The scope in which the class was parsed. Null if we didn't just
6321 /// parse a class definition.
6322 /// \param Record The completed class.
6323 void Sema::CheckCompletedCXXClass(Scope *S, CXXRecordDecl *Record) {
6327 if (Record->isAbstract() && !Record->isInvalidDecl()) {
6328 AbstractUsageInfo Info(*this, Record);
6329 CheckAbstractClassUsage(Info, Record);
6332 // If this is not an aggregate type and has no user-declared constructor,
6333 // complain about any non-static data members of reference or const scalar
6334 // type, since they will never get initializers.
6335 if (!Record->isInvalidDecl() && !Record->isDependentType() &&
6336 !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
6337 !Record->isLambda()) {
6338 bool Complained = false;
6339 for (const auto *F : Record->fields()) {
6340 if (F->hasInClassInitializer() || F->isUnnamedBitfield())
6343 if (F->getType()->isReferenceType() ||
6344 (F->getType().isConstQualified() && F->getType()->isScalarType())) {
6346 Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
6347 << Record->getTagKind() << Record;
6351 Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
6352 << F->getType()->isReferenceType()
6353 << F->getDeclName();
6358 if (Record->getIdentifier()) {
6359 // C++ [class.mem]p13:
6360 // If T is the name of a class, then each of the following shall have a
6361 // name different from T:
6362 // - every member of every anonymous union that is a member of class T.
6364 // C++ [class.mem]p14:
6365 // In addition, if class T has a user-declared constructor (12.1), every
6366 // non-static data member of class T shall have a name different from T.
6367 DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
6368 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
6370 NamedDecl *D = (*I)->getUnderlyingDecl();
6371 if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
6372 Record->hasUserDeclaredConstructor()) ||
6373 isa<IndirectFieldDecl>(D)) {
6374 Diag((*I)->getLocation(), diag::err_member_name_of_class)
6375 << D->getDeclName();
6381 // Warn if the class has virtual methods but non-virtual public destructor.
6382 if (Record->isPolymorphic() && !Record->isDependentType()) {
6383 CXXDestructorDecl *dtor = Record->getDestructor();
6384 if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
6385 !Record->hasAttr<FinalAttr>())
6386 Diag(dtor ? dtor->getLocation() : Record->getLocation(),
6387 diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
6390 if (Record->isAbstract()) {
6391 if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
6392 Diag(Record->getLocation(), diag::warn_abstract_final_class)
6393 << FA->isSpelledAsSealed();
6394 DiagnoseAbstractType(Record);
6398 // Warn if the class has a final destructor but is not itself marked final.
6399 if (!Record->hasAttr<FinalAttr>()) {
6400 if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
6401 if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
6402 Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
6403 << FA->isSpelledAsSealed()
6404 << FixItHint::CreateInsertion(
6405 getLocForEndOfToken(Record->getLocation()),
6406 (FA->isSpelledAsSealed() ? " sealed" : " final"));
6407 Diag(Record->getLocation(),
6408 diag::note_final_dtor_non_final_class_silence)
6409 << Context.getRecordType(Record) << FA->isSpelledAsSealed();
6414 // See if trivial_abi has to be dropped.
6415 if (Record->hasAttr<TrivialABIAttr>())
6416 checkIllFormedTrivialABIStruct(*Record);
6418 // Set HasTrivialSpecialMemberForCall if the record has attribute
6420 bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
6423 Record->setHasTrivialSpecialMemberForCall();
6425 // Explicitly-defaulted secondary comparison functions (!=, <, <=, >, >=).
6426 // We check these last because they can depend on the properties of the
6427 // primary comparison functions (==, <=>).
6428 llvm::SmallVector<FunctionDecl*, 5> DefaultedSecondaryComparisons;
6430 auto CheckForDefaultedFunction = [&](FunctionDecl *FD) {
6431 if (!FD || FD->isInvalidDecl() || !FD->isExplicitlyDefaulted())
6434 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
6435 if (DFK.asComparison() == DefaultedComparisonKind::NotEqual ||
6436 DFK.asComparison() == DefaultedComparisonKind::Relational)
6437 DefaultedSecondaryComparisons.push_back(FD);
6439 CheckExplicitlyDefaultedFunction(S, FD);
6442 auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
6443 // Check whether the explicitly-defaulted members are valid.
6444 CheckForDefaultedFunction(M);
6446 // Skip the rest of the checks for a member of a dependent class.
6447 if (Record->isDependentType())
6450 // For an explicitly defaulted or deleted special member, we defer
6451 // determining triviality until the class is complete. That time is now!
6452 CXXSpecialMember CSM = getSpecialMember(M);
6453 if (!M->isImplicit() && !M->isUserProvided()) {
6454 if (CSM != CXXInvalid) {
6455 M->setTrivial(SpecialMemberIsTrivial(M, CSM));
6456 // Inform the class that we've finished declaring this member.
6457 Record->finishedDefaultedOrDeletedMember(M);
6458 M->setTrivialForCall(
6460 SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
6461 Record->setTrivialForCallFlags(M);
6465 // Set triviality for the purpose of calls if this is a user-provided
6466 // copy/move constructor or destructor.
6467 if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
6468 CSM == CXXDestructor) && M->isUserProvided()) {
6469 M->setTrivialForCall(HasTrivialABI);
6470 Record->setTrivialForCallFlags(M);
6473 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
6474 M->hasAttr<DLLExportAttr>()) {
6475 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6477 (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
6478 CSM == CXXDestructor))
6479 M->dropAttr<DLLExportAttr>();
6481 if (M->hasAttr<DLLExportAttr>()) {
6482 // Define after any fields with in-class initializers have been parsed.
6483 DelayedDllExportMemberFunctions.push_back(M);
6487 // Define defaulted constexpr virtual functions that override a base class
6488 // function right away.
6489 // FIXME: We can defer doing this until the vtable is marked as used.
6490 if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
6491 DefineImplicitSpecialMember(*this, M, M->getLocation());
6494 // Check the destructor before any other member function. We need to
6495 // determine whether it's trivial in order to determine whether the claas
6496 // type is a literal type, which is a prerequisite for determining whether
6497 // other special member functions are valid and whether they're implicitly
6499 if (CXXDestructorDecl *Dtor = Record->getDestructor())
6500 CompleteMemberFunction(Dtor);
6502 bool HasMethodWithOverrideControl = false,
6503 HasOverridingMethodWithoutOverrideControl = false;
6504 for (auto *D : Record->decls()) {
6505 if (auto *M = dyn_cast<CXXMethodDecl>(D)) {
6506 // FIXME: We could do this check for dependent types with non-dependent
6508 if (!Record->isDependentType()) {
6509 // See if a method overloads virtual methods in a base
6510 // class without overriding any.
6512 DiagnoseHiddenVirtualMethods(M);
6513 if (M->hasAttr<OverrideAttr>())
6514 HasMethodWithOverrideControl = true;
6515 else if (M->size_overridden_methods() > 0)
6516 HasOverridingMethodWithoutOverrideControl = true;
6519 if (!isa<CXXDestructorDecl>(M))
6520 CompleteMemberFunction(M);
6521 } else if (auto *F = dyn_cast<FriendDecl>(D)) {
6522 CheckForDefaultedFunction(
6523 dyn_cast_or_null<FunctionDecl>(F->getFriendDecl()));
6527 if (HasMethodWithOverrideControl &&
6528 HasOverridingMethodWithoutOverrideControl) {
6529 // At least one method has the 'override' control declared.
6530 // Diagnose all other overridden methods which do not have 'override'
6531 // specified on them.
6532 for (auto *M : Record->methods())
6533 DiagnoseAbsenceOfOverrideControl(M);
6536 // Check the defaulted secondary comparisons after any other member functions.
6537 for (FunctionDecl *FD : DefaultedSecondaryComparisons)
6538 CheckExplicitlyDefaultedFunction(S, FD);
6540 // ms_struct is a request to use the same ABI rules as MSVC. Check
6541 // whether this class uses any C++ features that are implemented
6542 // completely differently in MSVC, and if so, emit a diagnostic.
6543 // That diagnostic defaults to an error, but we allow projects to
6544 // map it down to a warning (or ignore it). It's a fairly common
6545 // practice among users of the ms_struct pragma to mass-annotate
6546 // headers, sweeping up a bunch of types that the project doesn't
6547 // really rely on MSVC-compatible layout for. We must therefore
6548 // support "ms_struct except for C++ stuff" as a secondary ABI.
6549 if (Record->isMsStruct(Context) &&
6550 (Record->isPolymorphic() || Record->getNumBases())) {
6551 Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
6554 checkClassLevelDLLAttribute(Record);
6555 checkClassLevelCodeSegAttribute(Record);
6557 bool ClangABICompat4 =
6558 Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
6559 TargetInfo::CallingConvKind CCK =
6560 Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
6561 bool CanPass = canPassInRegisters(*this, Record, CCK);
6563 // Do not change ArgPassingRestrictions if it has already been set to
6564 // APK_CanNeverPassInRegs.
6565 if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
6566 Record->setArgPassingRestrictions(CanPass
6567 ? RecordDecl::APK_CanPassInRegs
6568 : RecordDecl::APK_CannotPassInRegs);
6570 // If canPassInRegisters returns true despite the record having a non-trivial
6571 // destructor, the record is destructed in the callee. This happens only when
6572 // the record or one of its subobjects has a field annotated with trivial_abi
6573 // or a field qualified with ObjC __strong/__weak.
6574 if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
6575 Record->setParamDestroyedInCallee(true);
6576 else if (Record->hasNonTrivialDestructor())
6577 Record->setParamDestroyedInCallee(CanPass);
6579 if (getLangOpts().ForceEmitVTables) {
6580 // If we want to emit all the vtables, we need to mark it as used. This
6581 // is especially required for cases like vtable assumption loads.
6582 MarkVTableUsed(Record->getInnerLocStart(), Record);
6586 /// Look up the special member function that would be called by a special
6587 /// member function for a subobject of class type.
6589 /// \param Class The class type of the subobject.
6590 /// \param CSM The kind of special member function.
6591 /// \param FieldQuals If the subobject is a field, its cv-qualifiers.
6592 /// \param ConstRHS True if this is a copy operation with a const object
6593 /// on its RHS, that is, if the argument to the outer special member
6594 /// function is 'const' and this is not a field marked 'mutable'.
6595 static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
6596 Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
6597 unsigned FieldQuals, bool ConstRHS) {
6598 unsigned LHSQuals = 0;
6599 if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
6600 LHSQuals = FieldQuals;
6602 unsigned RHSQuals = FieldQuals;
6603 if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
6606 RHSQuals |= Qualifiers::Const;
6608 return S.LookupSpecialMember(Class, CSM,
6609 RHSQuals & Qualifiers::Const,
6610 RHSQuals & Qualifiers::Volatile,
6612 LHSQuals & Qualifiers::Const,
6613 LHSQuals & Qualifiers::Volatile);
6616 class Sema::InheritedConstructorInfo {
6618 SourceLocation UseLoc;
6620 /// A mapping from the base classes through which the constructor was
6621 /// inherited to the using shadow declaration in that base class (or a null
6622 /// pointer if the constructor was declared in that base class).
6623 llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
6627 InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
6628 ConstructorUsingShadowDecl *Shadow)
6629 : S(S), UseLoc(UseLoc) {
6630 bool DiagnosedMultipleConstructedBases = false;
6631 CXXRecordDecl *ConstructedBase = nullptr;
6632 UsingDecl *ConstructedBaseUsing = nullptr;
6634 // Find the set of such base class subobjects and check that there's a
6635 // unique constructed subobject.
6636 for (auto *D : Shadow->redecls()) {
6637 auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
6638 auto *DNominatedBase = DShadow->getNominatedBaseClass();
6639 auto *DConstructedBase = DShadow->getConstructedBaseClass();
6641 InheritedFromBases.insert(
6642 std::make_pair(DNominatedBase->getCanonicalDecl(),
6643 DShadow->getNominatedBaseClassShadowDecl()));
6644 if (DShadow->constructsVirtualBase())
6645 InheritedFromBases.insert(
6646 std::make_pair(DConstructedBase->getCanonicalDecl(),
6647 DShadow->getConstructedBaseClassShadowDecl()));
6649 assert(DNominatedBase == DConstructedBase);
6651 // [class.inhctor.init]p2:
6652 // If the constructor was inherited from multiple base class subobjects
6653 // of type B, the program is ill-formed.
6654 if (!ConstructedBase) {
6655 ConstructedBase = DConstructedBase;
6656 ConstructedBaseUsing = D->getUsingDecl();
6657 } else if (ConstructedBase != DConstructedBase &&
6658 !Shadow->isInvalidDecl()) {
6659 if (!DiagnosedMultipleConstructedBases) {
6660 S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
6661 << Shadow->getTargetDecl();
6662 S.Diag(ConstructedBaseUsing->getLocation(),
6663 diag::note_ambiguous_inherited_constructor_using)
6665 DiagnosedMultipleConstructedBases = true;
6667 S.Diag(D->getUsingDecl()->getLocation(),
6668 diag::note_ambiguous_inherited_constructor_using)
6669 << DConstructedBase;
6673 if (DiagnosedMultipleConstructedBases)
6674 Shadow->setInvalidDecl();
6677 /// Find the constructor to use for inherited construction of a base class,
6678 /// and whether that base class constructor inherits the constructor from a
6679 /// virtual base class (in which case it won't actually invoke it).
6680 std::pair<CXXConstructorDecl *, bool>
6681 findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
6682 auto It = InheritedFromBases.find(Base->getCanonicalDecl());
6683 if (It == InheritedFromBases.end())
6684 return std::make_pair(nullptr, false);
6686 // This is an intermediary class.
6688 return std::make_pair(
6689 S.findInheritingConstructor(UseLoc, Ctor, It->second),
6690 It->second->constructsVirtualBase());
6692 // This is the base class from which the constructor was inherited.
6693 return std::make_pair(Ctor, false);
6697 /// Is the special member function which would be selected to perform the
6698 /// specified operation on the specified class type a constexpr constructor?
6700 specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
6701 Sema::CXXSpecialMember CSM, unsigned Quals,
6703 CXXConstructorDecl *InheritedCtor = nullptr,
6704 Sema::InheritedConstructorInfo *Inherited = nullptr) {
6705 // If we're inheriting a constructor, see if we need to call it for this base
6707 if (InheritedCtor) {
6708 assert(CSM == Sema::CXXDefaultConstructor);
6710 Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
6712 return BaseCtor->isConstexpr();
6715 if (CSM == Sema::CXXDefaultConstructor)
6716 return ClassDecl->hasConstexprDefaultConstructor();
6717 if (CSM == Sema::CXXDestructor)
6718 return ClassDecl->hasConstexprDestructor();
6720 Sema::SpecialMemberOverloadResult SMOR =
6721 lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
6722 if (!SMOR.getMethod())
6723 // A constructor we wouldn't select can't be "involved in initializing"
6726 return SMOR.getMethod()->isConstexpr();
6729 /// Determine whether the specified special member function would be constexpr
6730 /// if it were implicitly defined.
6731 static bool defaultedSpecialMemberIsConstexpr(
6732 Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
6733 bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
6734 Sema::InheritedConstructorInfo *Inherited = nullptr) {
6735 if (!S.getLangOpts().CPlusPlus11)
6738 // C++11 [dcl.constexpr]p4:
6739 // In the definition of a constexpr constructor [...]
6742 case Sema::CXXDefaultConstructor:
6745 // Since default constructor lookup is essentially trivial (and cannot
6746 // involve, for instance, template instantiation), we compute whether a
6747 // defaulted default constructor is constexpr directly within CXXRecordDecl.
6749 // This is important for performance; we need to know whether the default
6750 // constructor is constexpr to determine whether the type is a literal type.
6751 return ClassDecl->defaultedDefaultConstructorIsConstexpr();
6753 case Sema::CXXCopyConstructor:
6754 case Sema::CXXMoveConstructor:
6755 // For copy or move constructors, we need to perform overload resolution.
6758 case Sema::CXXCopyAssignment:
6759 case Sema::CXXMoveAssignment:
6760 if (!S.getLangOpts().CPlusPlus14)
6762 // In C++1y, we need to perform overload resolution.
6766 case Sema::CXXDestructor:
6767 return ClassDecl->defaultedDestructorIsConstexpr();
6769 case Sema::CXXInvalid:
6773 // -- if the class is a non-empty union, or for each non-empty anonymous
6774 // union member of a non-union class, exactly one non-static data member
6775 // shall be initialized; [DR1359]
6777 // If we squint, this is guaranteed, since exactly one non-static data member
6778 // will be initialized (if the constructor isn't deleted), we just don't know
6780 if (Ctor && ClassDecl->isUnion())
6781 return CSM == Sema::CXXDefaultConstructor
6782 ? ClassDecl->hasInClassInitializer() ||
6783 !ClassDecl->hasVariantMembers()
6786 // -- the class shall not have any virtual base classes;
6787 if (Ctor && ClassDecl->getNumVBases())
6790 // C++1y [class.copy]p26:
6791 // -- [the class] is a literal type, and
6792 if (!Ctor && !ClassDecl->isLiteral())
6795 // -- every constructor involved in initializing [...] base class
6796 // sub-objects shall be a constexpr constructor;
6797 // -- the assignment operator selected to copy/move each direct base
6798 // class is a constexpr function, and
6799 for (const auto &B : ClassDecl->bases()) {
6800 const RecordType *BaseType = B.getType()->getAs<RecordType>();
6801 if (!BaseType) continue;
6803 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6804 if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
6805 InheritedCtor, Inherited))
6809 // -- every constructor involved in initializing non-static data members
6810 // [...] shall be a constexpr constructor;
6811 // -- every non-static data member and base class sub-object shall be
6813 // -- for each non-static data member of X that is of class type (or array
6814 // thereof), the assignment operator selected to copy/move that member is
6815 // a constexpr function
6816 for (const auto *F : ClassDecl->fields()) {
6817 if (F->isInvalidDecl())
6819 if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
6821 QualType BaseType = S.Context.getBaseElementType(F->getType());
6822 if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
6823 CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
6824 if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
6825 BaseType.getCVRQualifiers(),
6826 ConstArg && !F->isMutable()))
6828 } else if (CSM == Sema::CXXDefaultConstructor) {
6833 // All OK, it's constexpr!
6838 /// RAII object to register a defaulted function as having its exception
6839 /// specification computed.
6840 struct ComputingExceptionSpec {
6843 ComputingExceptionSpec(Sema &S, FunctionDecl *FD, SourceLocation Loc)
6845 Sema::CodeSynthesisContext Ctx;
6846 Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
6847 Ctx.PointOfInstantiation = Loc;
6849 S.pushCodeSynthesisContext(Ctx);
6851 ~ComputingExceptionSpec() {
6852 S.popCodeSynthesisContext();
6857 static Sema::ImplicitExceptionSpecification
6858 ComputeDefaultedSpecialMemberExceptionSpec(
6859 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
6860 Sema::InheritedConstructorInfo *ICI);
6862 static Sema::ImplicitExceptionSpecification
6863 ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
6865 Sema::DefaultedComparisonKind DCK);
6867 static Sema::ImplicitExceptionSpecification
6868 computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, FunctionDecl *FD) {
6869 auto DFK = S.getDefaultedFunctionKind(FD);
6870 if (DFK.isSpecialMember())
6871 return ComputeDefaultedSpecialMemberExceptionSpec(
6872 S, Loc, cast<CXXMethodDecl>(FD), DFK.asSpecialMember(), nullptr);
6873 if (DFK.isComparison())
6874 return ComputeDefaultedComparisonExceptionSpec(S, Loc, FD,
6875 DFK.asComparison());
6877 auto *CD = cast<CXXConstructorDecl>(FD);
6878 assert(CD->getInheritedConstructor() &&
6879 "only defaulted functions and inherited constructors have implicit "
6881 Sema::InheritedConstructorInfo ICI(
6882 S, Loc, CD->getInheritedConstructor().getShadowDecl());
6883 return ComputeDefaultedSpecialMemberExceptionSpec(
6884 S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
6887 static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
6888 CXXMethodDecl *MD) {
6889 FunctionProtoType::ExtProtoInfo EPI;
6891 // Build an exception specification pointing back at this member.
6892 EPI.ExceptionSpec.Type = EST_Unevaluated;
6893 EPI.ExceptionSpec.SourceDecl = MD;
6895 // Set the calling convention to the default for C++ instance methods.
6896 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
6897 S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
6898 /*IsCXXMethod=*/true));
6902 void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, FunctionDecl *FD) {
6903 const FunctionProtoType *FPT = FD->getType()->castAs<FunctionProtoType>();
6904 if (FPT->getExceptionSpecType() != EST_Unevaluated)
6907 // Evaluate the exception specification.
6908 auto IES = computeImplicitExceptionSpec(*this, Loc, FD);
6909 auto ESI = IES.getExceptionSpec();
6911 // Update the type of the special member to use it.
6912 UpdateExceptionSpec(FD, ESI);
6915 void Sema::CheckExplicitlyDefaultedFunction(Scope *S, FunctionDecl *FD) {
6916 assert(FD->isExplicitlyDefaulted() && "not explicitly-defaulted");
6918 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
6920 assert(FD->getDeclContext()->isDependentContext());
6924 if (DefKind.isSpecialMember()
6925 ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
6926 DefKind.asSpecialMember())
6927 : CheckExplicitlyDefaultedComparison(S, FD, DefKind.asComparison()))
6928 FD->setInvalidDecl();
6931 bool Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD,
6932 CXXSpecialMember CSM) {
6933 CXXRecordDecl *RD = MD->getParent();
6935 assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
6936 "not an explicitly-defaulted special member");
6938 // Defer all checking for special members of a dependent type.
6939 if (RD->isDependentType())
6942 // Whether this was the first-declared instance of the constructor.
6943 // This affects whether we implicitly add an exception spec and constexpr.
6944 bool First = MD == MD->getCanonicalDecl();
6946 bool HadError = false;
6948 // C++11 [dcl.fct.def.default]p1:
6949 // A function that is explicitly defaulted shall
6950 // -- be a special member function [...] (checked elsewhere),
6951 // -- have the same type (except for ref-qualifiers, and except that a
6952 // copy operation can take a non-const reference) as an implicit
6954 // -- not have default arguments.
6955 // C++2a changes the second bullet to instead delete the function if it's
6956 // defaulted on its first declaration, unless it's "an assignment operator,
6957 // and its return type differs or its parameter type is not a reference".
6958 bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus2a && First;
6959 bool ShouldDeleteForTypeMismatch = false;
6960 unsigned ExpectedParams = 1;
6961 if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
6963 if (MD->getNumParams() != ExpectedParams) {
6964 // This checks for default arguments: a copy or move constructor with a
6965 // default argument is classified as a default constructor, and assignment
6966 // operations and destructors can't have default arguments.
6967 Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
6968 << CSM << MD->getSourceRange();
6970 } else if (MD->isVariadic()) {
6971 if (DeleteOnTypeMismatch)
6972 ShouldDeleteForTypeMismatch = true;
6974 Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
6975 << CSM << MD->getSourceRange();
6980 const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
6982 bool CanHaveConstParam = false;
6983 if (CSM == CXXCopyConstructor)
6984 CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
6985 else if (CSM == CXXCopyAssignment)
6986 CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();
6988 QualType ReturnType = Context.VoidTy;
6989 if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
6990 // Check for return type matching.
6991 ReturnType = Type->getReturnType();
6993 QualType DeclType = Context.getTypeDeclType(RD);
6994 DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
6995 QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);
6997 if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
6998 Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
6999 << (CSM == CXXMoveAssignment) << ExpectedReturnType;
7003 // A defaulted special member cannot have cv-qualifiers.
7004 if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
7005 if (DeleteOnTypeMismatch)
7006 ShouldDeleteForTypeMismatch = true;
7008 Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
7009 << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
7015 // Check for parameter type matching.
7016 QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
7017 bool HasConstParam = false;
7018 if (ExpectedParams && ArgType->isReferenceType()) {
7019 // Argument must be reference to possibly-const T.
7020 QualType ReferentType = ArgType->getPointeeType();
7021 HasConstParam = ReferentType.isConstQualified();
7023 if (ReferentType.isVolatileQualified()) {
7024 if (DeleteOnTypeMismatch)
7025 ShouldDeleteForTypeMismatch = true;
7027 Diag(MD->getLocation(),
7028 diag::err_defaulted_special_member_volatile_param) << CSM;
7033 if (HasConstParam && !CanHaveConstParam) {
7034 if (DeleteOnTypeMismatch)
7035 ShouldDeleteForTypeMismatch = true;
7036 else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
7037 Diag(MD->getLocation(),
7038 diag::err_defaulted_special_member_copy_const_param)
7039 << (CSM == CXXCopyAssignment);
7040 // FIXME: Explain why this special member can't be const.
7043 Diag(MD->getLocation(),
7044 diag::err_defaulted_special_member_move_const_param)
7045 << (CSM == CXXMoveAssignment);
7049 } else if (ExpectedParams) {
7050 // A copy assignment operator can take its argument by value, but a
7051 // defaulted one cannot.
7052 assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
7053 Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
7057 // C++11 [dcl.fct.def.default]p2:
7058 // An explicitly-defaulted function may be declared constexpr only if it
7059 // would have been implicitly declared as constexpr,
7060 // Do not apply this rule to members of class templates, since core issue 1358
7061 // makes such functions always instantiate to constexpr functions. For
7062 // functions which cannot be constexpr (for non-constructors in C++11 and for
7063 // destructors in C++14 and C++17), this is checked elsewhere.
7065 // FIXME: This should not apply if the member is deleted.
7066 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
7068 if ((getLangOpts().CPlusPlus2a ||
7069 (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
7070 : isa<CXXConstructorDecl>(MD))) &&
7071 MD->isConstexpr() && !Constexpr &&
7072 MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
7073 Diag(MD->getBeginLoc(), MD->isConsteval()
7074 ? diag::err_incorrect_defaulted_consteval
7075 : diag::err_incorrect_defaulted_constexpr)
7077 // FIXME: Explain why the special member can't be constexpr.
7082 // C++2a [dcl.fct.def.default]p3:
7083 // If a function is explicitly defaulted on its first declaration, it is
7084 // implicitly considered to be constexpr if the implicit declaration
7086 MD->setConstexprKind(Constexpr ? CSK_constexpr : CSK_unspecified);
7088 if (!Type->hasExceptionSpec()) {
7089 // C++2a [except.spec]p3:
7090 // If a declaration of a function does not have a noexcept-specifier
7091 // [and] is defaulted on its first declaration, [...] the exception
7092 // specification is as specified below
7093 FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
7094 EPI.ExceptionSpec.Type = EST_Unevaluated;
7095 EPI.ExceptionSpec.SourceDecl = MD;
7096 MD->setType(Context.getFunctionType(ReturnType,
7097 llvm::makeArrayRef(&ArgType,
7103 if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
7105 SetDeclDeleted(MD, MD->getLocation());
7106 if (!inTemplateInstantiation() && !HadError) {
7107 Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
7108 if (ShouldDeleteForTypeMismatch) {
7109 Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
7111 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7114 if (ShouldDeleteForTypeMismatch && !HadError) {
7115 Diag(MD->getLocation(),
7116 diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
7119 // C++11 [dcl.fct.def.default]p4:
7120 // [For a] user-provided explicitly-defaulted function [...] if such a
7121 // function is implicitly defined as deleted, the program is ill-formed.
7122 Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
7123 assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl");
7124 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
7133 /// Helper class for building and checking a defaulted comparison.
7135 /// Defaulted functions are built in two phases:
7137 /// * First, the set of operations that the function will perform are
7138 /// identified, and some of them are checked. If any of the checked
7139 /// operations is invalid in certain ways, the comparison function is
7140 /// defined as deleted and no body is built.
7141 /// * Then, if the function is not defined as deleted, the body is built.
7143 /// This is accomplished by performing two visitation steps over the eventual
7144 /// body of the function.
7145 template<typename Derived, typename ResultList, typename Result,
7147 class DefaultedComparisonVisitor {
7149 using DefaultedComparisonKind = Sema::DefaultedComparisonKind;
7151 DefaultedComparisonVisitor(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7152 DefaultedComparisonKind DCK)
7153 : S(S), RD(RD), FD(FD), DCK(DCK) {
7154 if (auto *Info = FD->getDefaultedFunctionInfo()) {
7155 // FIXME: Change CreateOverloadedBinOp to take an ArrayRef instead of an
7156 // UnresolvedSet to avoid this copy.
7157 Fns.assign(Info->getUnqualifiedLookups().begin(),
7158 Info->getUnqualifiedLookups().end());
7162 ResultList visit() {
7163 // The type of an lvalue naming a parameter of this function.
7164 QualType ParamLvalType =
7165 FD->getParamDecl(0)->getType().getNonReferenceType();
7170 case DefaultedComparisonKind::None:
7171 llvm_unreachable("not a defaulted comparison");
7173 case DefaultedComparisonKind::Equal:
7174 case DefaultedComparisonKind::ThreeWay:
7175 getDerived().visitSubobjects(Results, RD, ParamLvalType.getQualifiers());
7178 case DefaultedComparisonKind::NotEqual:
7179 case DefaultedComparisonKind::Relational:
7180 Results.add(getDerived().visitExpandedSubobject(
7181 ParamLvalType, getDerived().getCompleteObject()));
7184 llvm_unreachable("");
7188 Derived &getDerived() { return static_cast<Derived&>(*this); }
7190 /// Visit the expanded list of subobjects of the given type, as specified in
7191 /// C++2a [class.compare.default].
7193 /// \return \c true if the ResultList object said we're done, \c false if not.
7194 bool visitSubobjects(ResultList &Results, CXXRecordDecl *Record,
7196 // C++2a [class.compare.default]p4:
7197 // The direct base class subobjects of C
7198 for (CXXBaseSpecifier &Base : Record->bases())
7199 if (Results.add(getDerived().visitSubobject(
7200 S.Context.getQualifiedType(Base.getType(), Quals),
7201 getDerived().getBase(&Base))))
7204 // followed by the non-static data members of C
7205 for (FieldDecl *Field : Record->fields()) {
7206 // Recursively expand anonymous structs.
7207 if (Field->isAnonymousStructOrUnion()) {
7208 if (visitSubobjects(Results, Field->getType()->getAsCXXRecordDecl(),
7214 // Figure out the type of an lvalue denoting this field.
7215 Qualifiers FieldQuals = Quals;
7216 if (Field->isMutable())
7217 FieldQuals.removeConst();
7218 QualType FieldType =
7219 S.Context.getQualifiedType(Field->getType(), FieldQuals);
7221 if (Results.add(getDerived().visitSubobject(
7222 FieldType, getDerived().getField(Field))))
7226 // form a list of subobjects.
7230 Result visitSubobject(QualType Type, Subobject Subobj) {
7231 // In that list, any subobject of array type is recursively expanded
7232 const ArrayType *AT = S.Context.getAsArrayType(Type);
7233 if (auto *CAT = dyn_cast_or_null<ConstantArrayType>(AT))
7234 return getDerived().visitSubobjectArray(CAT->getElementType(),
7235 CAT->getSize(), Subobj);
7236 return getDerived().visitExpandedSubobject(Type, Subobj);
7239 Result visitSubobjectArray(QualType Type, const llvm::APInt &Size,
7241 return getDerived().visitSubobject(Type, Subobj);
7248 DefaultedComparisonKind DCK;
7249 UnresolvedSet<16> Fns;
7252 /// Information about a defaulted comparison, as determined by
7253 /// DefaultedComparisonAnalyzer.
7254 struct DefaultedComparisonInfo {
7255 bool Deleted = false;
7256 bool Constexpr = true;
7257 ComparisonCategoryType Category = ComparisonCategoryType::StrongOrdering;
7259 static DefaultedComparisonInfo deleted() {
7260 DefaultedComparisonInfo Deleted;
7261 Deleted.Deleted = true;
7265 bool add(const DefaultedComparisonInfo &R) {
7266 Deleted |= R.Deleted;
7267 Constexpr &= R.Constexpr;
7268 Category = commonComparisonType(Category, R.Category);
7273 /// An element in the expanded list of subobjects of a defaulted comparison, as
7274 /// specified in C++2a [class.compare.default]p4.
7275 struct DefaultedComparisonSubobject {
7276 enum { CompleteObject, Member, Base } Kind;
7281 /// A visitor over the notional body of a defaulted comparison that determines
7282 /// whether that body would be deleted or constexpr.
7283 class DefaultedComparisonAnalyzer
7284 : public DefaultedComparisonVisitor<DefaultedComparisonAnalyzer,
7285 DefaultedComparisonInfo,
7286 DefaultedComparisonInfo,
7287 DefaultedComparisonSubobject> {
7289 enum DiagnosticKind { NoDiagnostics, ExplainDeleted, ExplainConstexpr };
7292 DiagnosticKind Diagnose;
7295 using Base = DefaultedComparisonVisitor;
7296 using Result = DefaultedComparisonInfo;
7297 using Subobject = DefaultedComparisonSubobject;
7301 DefaultedComparisonAnalyzer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7302 DefaultedComparisonKind DCK,
7303 DiagnosticKind Diagnose = NoDiagnostics)
7304 : Base(S, RD, FD, DCK), Diagnose(Diagnose) {}
7307 if ((DCK == DefaultedComparisonKind::Equal ||
7308 DCK == DefaultedComparisonKind::ThreeWay) &&
7309 RD->hasVariantMembers()) {
7310 // C++2a [class.compare.default]p2 [P2002R0]:
7311 // A defaulted comparison operator function for class C is defined as
7312 // deleted if [...] C has variant members.
7313 if (Diagnose == ExplainDeleted) {
7314 S.Diag(FD->getLocation(), diag::note_defaulted_comparison_union)
7315 << FD << RD->isUnion() << RD;
7317 return Result::deleted();
7320 return Base::visit();
7324 Subobject getCompleteObject() {
7325 return Subobject{Subobject::CompleteObject, nullptr, FD->getLocation()};
7328 Subobject getBase(CXXBaseSpecifier *Base) {
7329 return Subobject{Subobject::Base, Base->getType()->getAsCXXRecordDecl(),
7330 Base->getBaseTypeLoc()};
7333 Subobject getField(FieldDecl *Field) {
7334 return Subobject{Subobject::Member, Field, Field->getLocation()};
7337 Result visitExpandedSubobject(QualType Type, Subobject Subobj) {
7338 // C++2a [class.compare.default]p2 [P2002R0]:
7339 // A defaulted <=> or == operator function for class C is defined as
7340 // deleted if any non-static data member of C is of reference type
7341 if (Type->isReferenceType()) {
7342 if (Diagnose == ExplainDeleted) {
7343 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_reference_member)
7346 return Result::deleted();
7349 // [...] Let xi be an lvalue denoting the ith element [...]
7350 OpaqueValueExpr Xi(FD->getLocation(), Type, VK_LValue);
7351 Expr *Args[] = {&Xi, &Xi};
7353 // All operators start by trying to apply that same operator recursively.
7354 OverloadedOperatorKind OO = FD->getOverloadedOperator();
7355 assert(OO != OO_None && "not an overloaded operator!");
7356 return visitBinaryOperator(OO, Args, Subobj);
7360 visitBinaryOperator(OverloadedOperatorKind OO, ArrayRef<Expr *> Args,
7362 OverloadCandidateSet *SpaceshipCandidates = nullptr) {
7363 // Note that there is no need to consider rewritten candidates here if
7364 // we've already found there is no viable 'operator<=>' candidate (and are
7365 // considering synthesizing a '<=>' from '==' and '<').
7366 OverloadCandidateSet CandidateSet(
7367 FD->getLocation(), OverloadCandidateSet::CSK_Operator,
7368 OverloadCandidateSet::OperatorRewriteInfo(
7369 OO, /*AllowRewrittenCandidates=*/!SpaceshipCandidates));
7371 /// C++2a [class.compare.default]p1 [P2002R0]:
7372 /// [...] the defaulted function itself is never a candidate for overload
7373 /// resolution [...]
7374 CandidateSet.exclude(FD);
7376 if (Args[0]->getType()->isOverloadableType())
7377 S.LookupOverloadedBinOp(CandidateSet, OO, Fns, Args);
7379 // FIXME: We determine whether this is a valid expression by checking to
7380 // see if there's a viable builtin operator candidate for it. That isn't
7381 // really what the rules ask us to do, but should give the right results.
7382 S.AddBuiltinOperatorCandidates(OO, FD->getLocation(), Args, CandidateSet);
7387 OverloadCandidateSet::iterator Best;
7388 switch (CandidateSet.BestViableFunction(S, FD->getLocation(), Best)) {
7390 // C++2a [class.compare.secondary]p2 [P2002R0]:
7391 // The operator function [...] is defined as deleted if [...] the
7392 // candidate selected by overload resolution is not a rewritten
7394 if ((DCK == DefaultedComparisonKind::NotEqual ||
7395 DCK == DefaultedComparisonKind::Relational) &&
7396 !Best->RewriteKind) {
7397 if (Diagnose == ExplainDeleted) {
7398 S.Diag(Best->Function->getLocation(),
7399 diag::note_defaulted_comparison_not_rewritten_callee)
7402 return Result::deleted();
7405 // Throughout C++2a [class.compare]: if overload resolution does not
7406 // result in a usable function, the candidate function is defined as
7407 // deleted. This requires that we selected an accessible function.
7409 // Note that this only considers the access of the function when named
7410 // within the type of the subobject, and not the access path for any
7411 // derived-to-base conversion.
7412 CXXRecordDecl *ArgClass = Args[0]->getType()->getAsCXXRecordDecl();
7413 if (ArgClass && Best->FoundDecl.getDecl() &&
7414 Best->FoundDecl.getDecl()->isCXXClassMember()) {
7415 QualType ObjectType = Subobj.Kind == Subobject::Member
7416 ? Args[0]->getType()
7417 : S.Context.getRecordType(RD);
7418 if (!S.isMemberAccessibleForDeletion(
7419 ArgClass, Best->FoundDecl, ObjectType, Subobj.Loc,
7420 Diagnose == ExplainDeleted
7421 ? S.PDiag(diag::note_defaulted_comparison_inaccessible)
7422 << FD << Subobj.Kind << Subobj.Decl
7424 return Result::deleted();
7427 // C++2a [class.compare.default]p3 [P2002R0]:
7428 // A defaulted comparison function is constexpr-compatible if [...]
7429 // no overlod resolution performed [...] results in a non-constexpr
7431 if (FunctionDecl *BestFD = Best->Function) {
7432 assert(!BestFD->isDeleted() && "wrong overload resolution result");
7433 // If it's not constexpr, explain why not.
7434 if (Diagnose == ExplainConstexpr && !BestFD->isConstexpr()) {
7435 if (Subobj.Kind != Subobject::CompleteObject)
7436 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_not_constexpr)
7437 << Subobj.Kind << Subobj.Decl;
7438 S.Diag(BestFD->getLocation(),
7439 diag::note_defaulted_comparison_not_constexpr_here);
7440 // Bail out after explaining; we don't want any more notes.
7441 return Result::deleted();
7443 R.Constexpr &= BestFD->isConstexpr();
7446 if (OO == OO_Spaceship && FD->getReturnType()->isUndeducedAutoType()) {
7447 if (auto *BestFD = Best->Function) {
7448 // If any callee has an undeduced return type, deduce it now.
7449 // FIXME: It's not clear how a failure here should be handled. For
7450 // now, we produce an eager diagnostic, because that is forward
7451 // compatible with most (all?) other reasonable options.
7452 if (BestFD->getReturnType()->isUndeducedType() &&
7453 S.DeduceReturnType(BestFD, FD->getLocation(),
7454 /*Diagnose=*/false)) {
7455 // Don't produce a duplicate error when asked to explain why the
7456 // comparison is deleted: we diagnosed that when initially checking
7457 // the defaulted operator.
7458 if (Diagnose == NoDiagnostics) {
7461 diag::err_defaulted_comparison_cannot_deduce_undeduced_auto)
7462 << Subobj.Kind << Subobj.Decl;
7465 diag::note_defaulted_comparison_cannot_deduce_undeduced_auto)
7466 << Subobj.Kind << Subobj.Decl;
7467 S.Diag(BestFD->getLocation(),
7468 diag::note_defaulted_comparison_cannot_deduce_callee)
7469 << Subobj.Kind << Subobj.Decl;
7471 return Result::deleted();
7473 if (auto *Info = S.Context.CompCategories.lookupInfoForType(
7474 BestFD->getCallResultType())) {
7475 R.Category = Info->Kind;
7477 if (Diagnose == ExplainDeleted) {
7478 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_cannot_deduce)
7479 << Subobj.Kind << Subobj.Decl
7480 << BestFD->getCallResultType().withoutLocalFastQualifiers();
7481 S.Diag(BestFD->getLocation(),
7482 diag::note_defaulted_comparison_cannot_deduce_callee)
7483 << Subobj.Kind << Subobj.Decl;
7485 return Result::deleted();
7488 Optional<ComparisonCategoryType> Cat =
7489 getComparisonCategoryForBuiltinCmp(Args[0]->getType());
7490 assert(Cat && "no category for builtin comparison?");
7495 // Note that we might be rewriting to a different operator. That call is
7496 // not considered until we come to actually build the comparison function.
7501 if (Diagnose == ExplainDeleted) {
7503 if (FD->getOverloadedOperator() == OO_Spaceship && OO != OO_Spaceship)
7504 Kind = OO == OO_EqualEqual ? 1 : 2;
7505 CandidateSet.NoteCandidates(
7506 PartialDiagnosticAt(
7507 Subobj.Loc, S.PDiag(diag::note_defaulted_comparison_ambiguous)
7508 << FD << Kind << Subobj.Kind << Subobj.Decl),
7509 S, OCD_AmbiguousCandidates, Args);
7511 R = Result::deleted();
7515 if (Diagnose == ExplainDeleted) {
7516 if ((DCK == DefaultedComparisonKind::NotEqual ||
7517 DCK == DefaultedComparisonKind::Relational) &&
7518 !Best->RewriteKind) {
7519 S.Diag(Best->Function->getLocation(),
7520 diag::note_defaulted_comparison_not_rewritten_callee)
7524 diag::note_defaulted_comparison_calls_deleted)
7525 << FD << Subobj.Kind << Subobj.Decl;
7526 S.NoteDeletedFunction(Best->Function);
7529 R = Result::deleted();
7532 case OR_No_Viable_Function:
7533 // If there's no usable candidate, we're done unless we can rewrite a
7534 // '<=>' in terms of '==' and '<'.
7535 if (OO == OO_Spaceship &&
7536 S.Context.CompCategories.lookupInfoForType(FD->getReturnType())) {
7537 // For any kind of comparison category return type, we need a usable
7538 // '==' and a usable '<'.
7539 if (!R.add(visitBinaryOperator(OO_EqualEqual, Args, Subobj,
7541 R.add(visitBinaryOperator(OO_Less, Args, Subobj, &CandidateSet));
7545 if (Diagnose == ExplainDeleted) {
7546 S.Diag(Subobj.Loc, diag::note_defaulted_comparison_no_viable_function)
7547 << FD << Subobj.Kind << Subobj.Decl;
7549 // For a three-way comparison, list both the candidates for the
7550 // original operator and the candidates for the synthesized operator.
7551 if (SpaceshipCandidates) {
7552 SpaceshipCandidates->NoteCandidates(
7554 SpaceshipCandidates->CompleteCandidates(S, OCD_AllCandidates,
7555 Args, FD->getLocation()));
7557 diag::note_defaulted_comparison_no_viable_function_synthesized)
7558 << (OO == OO_EqualEqual ? 0 : 1);
7561 CandidateSet.NoteCandidates(
7563 CandidateSet.CompleteCandidates(S, OCD_AllCandidates, Args,
7564 FD->getLocation()));
7566 R = Result::deleted();
7574 /// A list of statements.
7575 struct StmtListResult {
7576 bool IsInvalid = false;
7577 llvm::SmallVector<Stmt*, 16> Stmts;
7579 bool add(const StmtResult &S) {
7580 IsInvalid |= S.isInvalid();
7583 Stmts.push_back(S.get());
7588 /// A visitor over the notional body of a defaulted comparison that synthesizes
7589 /// the actual body.
7590 class DefaultedComparisonSynthesizer
7591 : public DefaultedComparisonVisitor<DefaultedComparisonSynthesizer,
7592 StmtListResult, StmtResult,
7593 std::pair<ExprResult, ExprResult>> {
7595 unsigned ArrayDepth = 0;
7598 using Base = DefaultedComparisonVisitor;
7599 using ExprPair = std::pair<ExprResult, ExprResult>;
7603 DefaultedComparisonSynthesizer(Sema &S, CXXRecordDecl *RD, FunctionDecl *FD,
7604 DefaultedComparisonKind DCK,
7605 SourceLocation BodyLoc)
7606 : Base(S, RD, FD, DCK), Loc(BodyLoc) {}
7608 /// Build a suitable function body for this defaulted comparison operator.
7609 StmtResult build() {
7610 Sema::CompoundScopeRAII CompoundScope(S);
7612 StmtListResult Stmts = visit();
7613 if (Stmts.IsInvalid)
7618 case DefaultedComparisonKind::None:
7619 llvm_unreachable("not a defaulted comparison");
7621 case DefaultedComparisonKind::Equal: {
7622 // C++2a [class.eq]p3:
7623 // [...] compar[e] the corresponding elements [...] until the first
7624 // index i where xi == yi yields [...] false. If no such index exists,
7625 // V is true. Otherwise, V is false.
7627 // Join the comparisons with '&&'s and return the result. Use a right
7628 // fold (traversing the conditions right-to-left), because that
7629 // short-circuits more naturally.
7630 auto OldStmts = std::move(Stmts.Stmts);
7631 Stmts.Stmts.clear();
7632 ExprResult CmpSoFar;
7633 // Finish a particular comparison chain.
7634 auto FinishCmp = [&] {
7635 if (Expr *Prior = CmpSoFar.get()) {
7636 // Convert the last expression to 'return ...;'
7637 if (RetVal.isUnset() && Stmts.Stmts.empty())
7639 // Convert any prior comparison to 'if (!(...)) return false;'
7640 else if (Stmts.add(buildIfNotCondReturnFalse(Prior)))
7642 CmpSoFar = ExprResult();
7646 for (Stmt *EAsStmt : llvm::reverse(OldStmts)) {
7647 Expr *E = dyn_cast<Expr>(EAsStmt);
7649 // Found an array comparison.
7650 if (FinishCmp() || Stmts.add(EAsStmt))
7655 if (CmpSoFar.isUnset()) {
7659 CmpSoFar = S.CreateBuiltinBinOp(Loc, BO_LAnd, E, CmpSoFar.get());
7660 if (CmpSoFar.isInvalid())
7665 std::reverse(Stmts.Stmts.begin(), Stmts.Stmts.end());
7666 // If no such index exists, V is true.
7667 if (RetVal.isUnset())
7668 RetVal = S.ActOnCXXBoolLiteral(Loc, tok::kw_true);
7672 case DefaultedComparisonKind::ThreeWay: {
7673 // Per C++2a [class.spaceship]p3, as a fallback add:
7674 // return static_cast<R>(std::strong_ordering::equal);
7675 QualType StrongOrdering = S.CheckComparisonCategoryType(
7676 ComparisonCategoryType::StrongOrdering, Loc,
7677 Sema::ComparisonCategoryUsage::DefaultedOperator);
7678 if (StrongOrdering.isNull())
7680 VarDecl *EqualVD = S.Context.CompCategories.getInfoForType(StrongOrdering)
7681 .getValueInfo(ComparisonCategoryResult::Equal)
7683 RetVal = getDecl(EqualVD);
7684 if (RetVal.isInvalid())
7686 RetVal = buildStaticCastToR(RetVal.get());
7690 case DefaultedComparisonKind::NotEqual:
7691 case DefaultedComparisonKind::Relational:
7692 RetVal = cast<Expr>(Stmts.Stmts.pop_back_val());
7696 // Build the final return statement.
7697 if (RetVal.isInvalid())
7699 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, RetVal.get());
7700 if (ReturnStmt.isInvalid())
7702 Stmts.Stmts.push_back(ReturnStmt.get());
7704 return S.ActOnCompoundStmt(Loc, Loc, Stmts.Stmts, /*IsStmtExpr=*/false);
7708 ExprResult getDecl(ValueDecl *VD) {
7709 return S.BuildDeclarationNameExpr(
7710 CXXScopeSpec(), DeclarationNameInfo(VD->getDeclName(), Loc), VD);
7713 ExprResult getParam(unsigned I) {
7714 ParmVarDecl *PD = FD->getParamDecl(I);
7718 ExprPair getCompleteObject() {
7721 if (isa<CXXMethodDecl>(FD)) {
7723 LHS = S.ActOnCXXThis(Loc);
7724 if (!LHS.isInvalid())
7725 LHS = S.CreateBuiltinUnaryOp(Loc, UO_Deref, LHS.get());
7727 LHS = getParam(Param++);
7729 ExprResult RHS = getParam(Param++);
7730 assert(Param == FD->getNumParams());
7734 ExprPair getBase(CXXBaseSpecifier *Base) {
7735 ExprPair Obj = getCompleteObject();
7736 if (Obj.first.isInvalid() || Obj.second.isInvalid())
7737 return {ExprError(), ExprError()};
7738 CXXCastPath Path = {Base};
7739 return {S.ImpCastExprToType(Obj.first.get(), Base->getType(),
7740 CK_DerivedToBase, VK_LValue, &Path),
7741 S.ImpCastExprToType(Obj.second.get(), Base->getType(),
7742 CK_DerivedToBase, VK_LValue, &Path)};
7745 ExprPair getField(FieldDecl *Field) {
7746 ExprPair Obj = getCompleteObject();
7747 if (Obj.first.isInvalid() || Obj.second.isInvalid())
7748 return {ExprError(), ExprError()};
7750 DeclAccessPair Found = DeclAccessPair::make(Field, Field->getAccess());
7751 DeclarationNameInfo NameInfo(Field->getDeclName(), Loc);
7752 return {S.BuildFieldReferenceExpr(Obj.first.get(), /*IsArrow=*/false, Loc,
7753 CXXScopeSpec(), Field, Found, NameInfo),
7754 S.BuildFieldReferenceExpr(Obj.second.get(), /*IsArrow=*/false, Loc,
7755 CXXScopeSpec(), Field, Found, NameInfo)};
7758 // FIXME: When expanding a subobject, register a note in the code synthesis
7759 // stack to say which subobject we're comparing.
7761 StmtResult buildIfNotCondReturnFalse(ExprResult Cond) {
7762 if (Cond.isInvalid())
7765 ExprResult NotCond = S.CreateBuiltinUnaryOp(Loc, UO_LNot, Cond.get());
7766 if (NotCond.isInvalid())
7769 ExprResult False = S.ActOnCXXBoolLiteral(Loc, tok::kw_false);
7770 assert(!False.isInvalid() && "should never fail");
7771 StmtResult ReturnFalse = S.BuildReturnStmt(Loc, False.get());
7772 if (ReturnFalse.isInvalid())
7775 return S.ActOnIfStmt(Loc, false, nullptr,
7776 S.ActOnCondition(nullptr, Loc, NotCond.get(),
7777 Sema::ConditionKind::Boolean),
7778 ReturnFalse.get(), SourceLocation(), nullptr);
7781 StmtResult visitSubobjectArray(QualType Type, llvm::APInt Size,
7783 QualType SizeType = S.Context.getSizeType();
7784 Size = Size.zextOrTrunc(S.Context.getTypeSize(SizeType));
7786 // Build 'size_t i$n = 0'.
7787 IdentifierInfo *IterationVarName = nullptr;
7790 llvm::raw_svector_ostream OS(Str);
7791 OS << "i" << ArrayDepth;
7792 IterationVarName = &S.Context.Idents.get(OS.str());
7794 VarDecl *IterationVar = VarDecl::Create(
7795 S.Context, S.CurContext, Loc, Loc, IterationVarName, SizeType,
7796 S.Context.getTrivialTypeSourceInfo(SizeType, Loc), SC_None);
7797 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
7798 IterationVar->setInit(
7799 IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
7800 Stmt *Init = new (S.Context) DeclStmt(DeclGroupRef(IterationVar), Loc, Loc);
7802 auto IterRef = [&] {
7803 ExprResult Ref = S.BuildDeclarationNameExpr(
7804 CXXScopeSpec(), DeclarationNameInfo(IterationVarName, Loc),
7806 assert(!Ref.isInvalid() && "can't reference our own variable?");
7810 // Build 'i$n != Size'.
7811 ExprResult Cond = S.CreateBuiltinBinOp(
7812 Loc, BO_NE, IterRef(),
7813 IntegerLiteral::Create(S.Context, Size, SizeType, Loc));
7814 assert(!Cond.isInvalid() && "should never fail");
7817 ExprResult Inc = S.CreateBuiltinUnaryOp(Loc, UO_PreInc, IterRef());
7818 assert(!Inc.isInvalid() && "should never fail");
7820 // Build 'a[i$n]' and 'b[i$n]'.
7821 auto Index = [&](ExprResult E) {
7824 return S.CreateBuiltinArraySubscriptExpr(E.get(), Loc, IterRef(), Loc);
7826 Subobj.first = Index(Subobj.first);
7827 Subobj.second = Index(Subobj.second);
7829 // Compare the array elements.
7831 StmtResult Substmt = visitSubobject(Type, Subobj);
7834 if (Substmt.isInvalid())
7837 // For the inner level of an 'operator==', build 'if (!cmp) return false;'.
7838 // For outer levels or for an 'operator<=>' we already have a suitable
7839 // statement that returns as necessary.
7840 if (Expr *ElemCmp = dyn_cast<Expr>(Substmt.get())) {
7841 assert(DCK == DefaultedComparisonKind::Equal &&
7842 "should have non-expression statement");
7843 Substmt = buildIfNotCondReturnFalse(ElemCmp);
7844 if (Substmt.isInvalid())
7848 // Build 'for (...) ...'
7849 return S.ActOnForStmt(Loc, Loc, Init,
7850 S.ActOnCondition(nullptr, Loc, Cond.get(),
7851 Sema::ConditionKind::Boolean),
7852 S.MakeFullDiscardedValueExpr(Inc.get()), Loc,
7856 StmtResult visitExpandedSubobject(QualType Type, ExprPair Obj) {
7857 if (Obj.first.isInvalid() || Obj.second.isInvalid())
7860 OverloadedOperatorKind OO = FD->getOverloadedOperator();
7861 BinaryOperatorKind Opc = BinaryOperator::getOverloadedOpcode(OO);
7863 if (Type->isOverloadableType())
7864 Op = S.CreateOverloadedBinOp(Loc, Opc, Fns, Obj.first.get(),
7865 Obj.second.get(), /*PerformADL=*/true,
7866 /*AllowRewrittenCandidates=*/true, FD);
7868 Op = S.CreateBuiltinBinOp(Loc, Opc, Obj.first.get(), Obj.second.get());
7873 case DefaultedComparisonKind::None:
7874 llvm_unreachable("not a defaulted comparison");
7876 case DefaultedComparisonKind::Equal:
7877 // Per C++2a [class.eq]p2, each comparison is individually contextually
7878 // converted to bool.
7879 Op = S.PerformContextuallyConvertToBool(Op.get());
7884 case DefaultedComparisonKind::ThreeWay: {
7885 // Per C++2a [class.spaceship]p3, form:
7886 // if (R cmp = static_cast<R>(op); cmp != 0)
7888 QualType R = FD->getReturnType();
7889 Op = buildStaticCastToR(Op.get());
7894 IdentifierInfo *Name = &S.Context.Idents.get("cmp");
7896 VarDecl::Create(S.Context, S.CurContext, Loc, Loc, Name, R,
7897 S.Context.getTrivialTypeSourceInfo(R, Loc), SC_None);
7898 S.AddInitializerToDecl(VD, Op.get(), /*DirectInit=*/false);
7899 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(VD), Loc, Loc);
7902 ExprResult VDRef = getDecl(VD);
7903 if (VDRef.isInvalid())
7905 llvm::APInt ZeroVal(S.Context.getIntWidth(S.Context.IntTy), 0);
7907 IntegerLiteral::Create(S.Context, ZeroVal, S.Context.IntTy, Loc);
7909 if (VDRef.get()->getType()->isOverloadableType())
7910 Comp = S.CreateOverloadedBinOp(Loc, BO_NE, Fns, VDRef.get(), Zero, true,
7913 Comp = S.CreateBuiltinBinOp(Loc, BO_NE, VDRef.get(), Zero);
7914 if (Comp.isInvalid())
7916 Sema::ConditionResult Cond = S.ActOnCondition(
7917 nullptr, Loc, Comp.get(), Sema::ConditionKind::Boolean);
7918 if (Cond.isInvalid())
7922 VDRef = getDecl(VD);
7923 if (VDRef.isInvalid())
7925 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, VDRef.get());
7926 if (ReturnStmt.isInvalid())
7930 return S.ActOnIfStmt(Loc, /*IsConstexpr=*/false, InitStmt, Cond,
7931 ReturnStmt.get(), /*ElseLoc=*/SourceLocation(),
7935 case DefaultedComparisonKind::NotEqual:
7936 case DefaultedComparisonKind::Relational:
7937 // C++2a [class.compare.secondary]p2:
7938 // Otherwise, the operator function yields x @ y.
7941 llvm_unreachable("");
7944 /// Build "static_cast<R>(E)".
7945 ExprResult buildStaticCastToR(Expr *E) {
7946 QualType R = FD->getReturnType();
7947 assert(!R->isUndeducedType() && "type should have been deduced already");
7949 // Don't bother forming a no-op cast in the common case.
7950 if (E->isRValue() && S.Context.hasSameType(E->getType(), R))
7952 return S.BuildCXXNamedCast(Loc, tok::kw_static_cast,
7953 S.Context.getTrivialTypeSourceInfo(R, Loc), E,
7954 SourceRange(Loc, Loc), SourceRange(Loc, Loc));
7959 /// Perform the unqualified lookups that might be needed to form a defaulted
7960 /// comparison function for the given operator.
7961 static void lookupOperatorsForDefaultedComparison(Sema &Self, Scope *S,
7962 UnresolvedSetImpl &Operators,
7963 OverloadedOperatorKind Op) {
7964 auto Lookup = [&](OverloadedOperatorKind OO) {
7965 Self.LookupOverloadedOperatorName(OO, S, QualType(), QualType(), Operators);
7968 // Every defaulted operator looks up itself.
7970 // ... and the rewritten form of itself, if any.
7971 if (OverloadedOperatorKind ExtraOp = getRewrittenOverloadedOperator(Op))
7974 // For 'operator<=>', we also form a 'cmp != 0' expression, and might
7975 // synthesize a three-way comparison from '<' and '=='. In a dependent
7976 // context, we also need to look up '==' in case we implicitly declare a
7977 // defaulted 'operator=='.
7978 if (Op == OO_Spaceship) {
7979 Lookup(OO_ExclaimEqual);
7981 Lookup(OO_EqualEqual);
7985 bool Sema::CheckExplicitlyDefaultedComparison(Scope *S, FunctionDecl *FD,
7986 DefaultedComparisonKind DCK) {
7987 assert(DCK != DefaultedComparisonKind::None && "not a defaulted comparison");
7989 CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(FD->getLexicalDeclContext());
7990 assert(RD && "defaulted comparison is not defaulted in a class");
7992 // Perform any unqualified lookups we're going to need to default this
7995 UnresolvedSet<32> Operators;
7996 lookupOperatorsForDefaultedComparison(*this, S, Operators,
7997 FD->getOverloadedOperator());
7998 FD->setDefaultedFunctionInfo(FunctionDecl::DefaultedFunctionInfo::Create(
7999 Context, Operators.pairs()));
8002 // C++2a [class.compare.default]p1:
8003 // A defaulted comparison operator function for some class C shall be a
8004 // non-template function declared in the member-specification of C that is
8005 // -- a non-static const member of C having one parameter of type
8007 // -- a friend of C having two parameters of type const C& or two
8008 // parameters of type C.
8009 QualType ExpectedParmType1 = Context.getRecordType(RD);
8010 QualType ExpectedParmType2 =
8011 Context.getLValueReferenceType(ExpectedParmType1.withConst());
8012 if (isa<CXXMethodDecl>(FD))
8013 ExpectedParmType1 = ExpectedParmType2;
8014 for (const ParmVarDecl *Param : FD->parameters()) {
8015 if (!Param->getType()->isDependentType() &&
8016 !Context.hasSameType(Param->getType(), ExpectedParmType1) &&
8017 !Context.hasSameType(Param->getType(), ExpectedParmType2)) {
8018 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8019 // corresponding defaulted 'operator<=>' already.
8020 if (!FD->isImplicit()) {
8021 Diag(FD->getLocation(), diag::err_defaulted_comparison_param)
8022 << (int)DCK << Param->getType() << ExpectedParmType1
8023 << !isa<CXXMethodDecl>(FD)
8024 << ExpectedParmType2 << Param->getSourceRange();
8029 if (FD->getNumParams() == 2 &&
8030 !Context.hasSameType(FD->getParamDecl(0)->getType(),
8031 FD->getParamDecl(1)->getType())) {
8032 if (!FD->isImplicit()) {
8033 Diag(FD->getLocation(), diag::err_defaulted_comparison_param_mismatch)
8035 << FD->getParamDecl(0)->getType()
8036 << FD->getParamDecl(0)->getSourceRange()
8037 << FD->getParamDecl(1)->getType()
8038 << FD->getParamDecl(1)->getSourceRange();
8043 // ... non-static const member ...
8044 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
8045 assert(!MD->isStatic() && "comparison function cannot be a static member");
8046 if (!MD->isConst()) {
8047 SourceLocation InsertLoc;
8048 if (FunctionTypeLoc Loc = MD->getFunctionTypeLoc())
8049 InsertLoc = getLocForEndOfToken(Loc.getRParenLoc());
8050 // Don't diagnose an implicit 'operator=='; we will have diagnosed the
8051 // corresponding defaulted 'operator<=>' already.
8052 if (!MD->isImplicit()) {
8053 Diag(MD->getLocation(), diag::err_defaulted_comparison_non_const)
8054 << (int)DCK << FixItHint::CreateInsertion(InsertLoc, " const");
8057 // Add the 'const' to the type to recover.
8058 const auto *FPT = MD->getType()->castAs<FunctionProtoType>();
8059 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8060 EPI.TypeQuals.addConst();
8061 MD->setType(Context.getFunctionType(FPT->getReturnType(),
8062 FPT->getParamTypes(), EPI));
8065 // A non-member function declared in a class must be a friend.
8066 assert(FD->getFriendObjectKind() && "expected a friend declaration");
8069 // C++2a [class.eq]p1, [class.rel]p1:
8070 // A [defaulted comparison other than <=>] shall have a declared return
8072 if (DCK != DefaultedComparisonKind::ThreeWay &&
8073 !FD->getDeclaredReturnType()->isDependentType() &&
8074 !Context.hasSameType(FD->getDeclaredReturnType(), Context.BoolTy)) {
8075 Diag(FD->getLocation(), diag::err_defaulted_comparison_return_type_not_bool)
8076 << (int)DCK << FD->getDeclaredReturnType() << Context.BoolTy
8077 << FD->getReturnTypeSourceRange();
8080 // C++2a [class.spaceship]p2 [P2002R0]:
8081 // Let R be the declared return type [...]. If R is auto, [...]. Otherwise,
8082 // R shall not contain a placeholder type.
8083 if (DCK == DefaultedComparisonKind::ThreeWay &&
8084 FD->getDeclaredReturnType()->getContainedDeducedType() &&
8085 !Context.hasSameType(FD->getDeclaredReturnType(),
8086 Context.getAutoDeductType())) {
8087 Diag(FD->getLocation(),
8088 diag::err_defaulted_comparison_deduced_return_type_not_auto)
8089 << (int)DCK << FD->getDeclaredReturnType() << Context.AutoDeductTy
8090 << FD->getReturnTypeSourceRange();
8094 // For a defaulted function in a dependent class, defer all remaining checks
8095 // until instantiation.
8096 if (RD->isDependentType())
8099 // Determine whether the function should be defined as deleted.
8100 DefaultedComparisonInfo Info =
8101 DefaultedComparisonAnalyzer(*this, RD, FD, DCK).visit();
8103 bool First = FD == FD->getCanonicalDecl();
8105 // If we want to delete the function, then do so; there's nothing else to
8106 // check in that case.
8109 // C++11 [dcl.fct.def.default]p4:
8110 // [For a] user-provided explicitly-defaulted function [...] if such a
8111 // function is implicitly defined as deleted, the program is ill-formed.
8113 // This is really just a consequence of the general rule that you can
8114 // only delete a function on its first declaration.
8115 Diag(FD->getLocation(), diag::err_non_first_default_compare_deletes)
8116 << FD->isImplicit() << (int)DCK;
8117 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8118 DefaultedComparisonAnalyzer::ExplainDeleted)
8123 SetDeclDeleted(FD, FD->getLocation());
8124 if (!inTemplateInstantiation() && !FD->isImplicit()) {
8125 Diag(FD->getLocation(), diag::warn_defaulted_comparison_deleted)
8127 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8128 DefaultedComparisonAnalyzer::ExplainDeleted)
8134 // C++2a [class.spaceship]p2:
8135 // The return type is deduced as the common comparison type of R0, R1, ...
8136 if (DCK == DefaultedComparisonKind::ThreeWay &&
8137 FD->getDeclaredReturnType()->isUndeducedAutoType()) {
8138 SourceLocation RetLoc = FD->getReturnTypeSourceRange().getBegin();
8139 if (RetLoc.isInvalid())
8140 RetLoc = FD->getBeginLoc();
8141 // FIXME: Should we really care whether we have the complete type and the
8142 // 'enumerator' constants here? A forward declaration seems sufficient.
8143 QualType Cat = CheckComparisonCategoryType(
8144 Info.Category, RetLoc, ComparisonCategoryUsage::DefaultedOperator);
8147 Context.adjustDeducedFunctionResultType(
8148 FD, SubstAutoType(FD->getDeclaredReturnType(), Cat));
8151 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8152 // An explicitly-defaulted function that is not defined as deleted may be
8153 // declared constexpr or consteval only if it is constexpr-compatible.
8154 // C++2a [class.compare.default]p3 [P2002R0]:
8155 // A defaulted comparison function is constexpr-compatible if it satisfies
8156 // the requirements for a constexpr function [...]
8157 // The only relevant requirements are that the parameter and return types are
8158 // literal types. The remaining conditions are checked by the analyzer.
8159 if (FD->isConstexpr()) {
8160 if (CheckConstexprReturnType(*this, FD, CheckConstexprKind::Diagnose) &&
8161 CheckConstexprParameterTypes(*this, FD, CheckConstexprKind::Diagnose) &&
8163 Diag(FD->getBeginLoc(),
8164 diag::err_incorrect_defaulted_comparison_constexpr)
8165 << FD->isImplicit() << (int)DCK << FD->isConsteval();
8166 DefaultedComparisonAnalyzer(*this, RD, FD, DCK,
8167 DefaultedComparisonAnalyzer::ExplainConstexpr)
8172 // C++2a [dcl.fct.def.default]p3 [P2002R0]:
8173 // If a constexpr-compatible function is explicitly defaulted on its first
8174 // declaration, it is implicitly considered to be constexpr.
8175 // FIXME: Only applying this to the first declaration seems problematic, as
8176 // simple reorderings can affect the meaning of the program.
8177 if (First && !FD->isConstexpr() && Info.Constexpr)
8178 FD->setConstexprKind(CSK_constexpr);
8180 // C++2a [except.spec]p3:
8181 // If a declaration of a function does not have a noexcept-specifier
8182 // [and] is defaulted on its first declaration, [...] the exception
8183 // specification is as specified below
8184 if (FD->getExceptionSpecType() == EST_None) {
8185 auto *FPT = FD->getType()->castAs<FunctionProtoType>();
8186 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
8187 EPI.ExceptionSpec.Type = EST_Unevaluated;
8188 EPI.ExceptionSpec.SourceDecl = FD;
8189 FD->setType(Context.getFunctionType(FPT->getReturnType(),
8190 FPT->getParamTypes(), EPI));
8196 void Sema::DeclareImplicitEqualityComparison(CXXRecordDecl *RD,
8197 FunctionDecl *Spaceship) {
8198 Sema::CodeSynthesisContext Ctx;
8199 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringImplicitEqualityComparison;
8200 Ctx.PointOfInstantiation = Spaceship->getEndLoc();
8201 Ctx.Entity = Spaceship;
8202 pushCodeSynthesisContext(Ctx);
8204 if (FunctionDecl *EqualEqual = SubstSpaceshipAsEqualEqual(RD, Spaceship))
8205 EqualEqual->setImplicit();
8207 popCodeSynthesisContext();
8210 void Sema::DefineDefaultedComparison(SourceLocation UseLoc, FunctionDecl *FD,
8211 DefaultedComparisonKind DCK) {
8212 assert(FD->isDefaulted() && !FD->isDeleted() &&
8213 !FD->doesThisDeclarationHaveABody());
8214 if (FD->willHaveBody() || FD->isInvalidDecl())
8217 SynthesizedFunctionScope Scope(*this, FD);
8219 // Add a context note for diagnostics produced after this point.
8220 Scope.addContextNote(UseLoc);
8223 // Build and set up the function body.
8224 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8225 SourceLocation BodyLoc =
8226 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8228 DefaultedComparisonSynthesizer(*this, RD, FD, DCK, BodyLoc).build();
8229 if (Body.isInvalid()) {
8230 FD->setInvalidDecl();
8233 FD->setBody(Body.get());
8234 FD->markUsed(Context);
8237 // The exception specification is needed because we are defining the
8238 // function. Note that this will reuse the body we just built.
8239 ResolveExceptionSpec(UseLoc, FD->getType()->castAs<FunctionProtoType>());
8241 if (ASTMutationListener *L = getASTMutationListener())
8242 L->CompletedImplicitDefinition(FD);
8245 static Sema::ImplicitExceptionSpecification
8246 ComputeDefaultedComparisonExceptionSpec(Sema &S, SourceLocation Loc,
8248 Sema::DefaultedComparisonKind DCK) {
8249 ComputingExceptionSpec CES(S, FD, Loc);
8250 Sema::ImplicitExceptionSpecification ExceptSpec(S);
8252 if (FD->isInvalidDecl())
8255 // The common case is that we just defined the comparison function. In that
8256 // case, just look at whether the body can throw.
8257 if (FD->hasBody()) {
8258 ExceptSpec.CalledStmt(FD->getBody());
8260 // Otherwise, build a body so we can check it. This should ideally only
8261 // happen when we're not actually marking the function referenced. (This is
8262 // only really important for efficiency: we don't want to build and throw
8263 // away bodies for comparison functions more than we strictly need to.)
8265 // Pretend to synthesize the function body in an unevaluated context.
8266 // Note that we can't actually just go ahead and define the function here:
8267 // we are not permitted to mark its callees as referenced.
8268 Sema::SynthesizedFunctionScope Scope(S, FD);
8269 EnterExpressionEvaluationContext Context(
8270 S, Sema::ExpressionEvaluationContext::Unevaluated);
8272 CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getLexicalParent());
8273 SourceLocation BodyLoc =
8274 FD->getEndLoc().isValid() ? FD->getEndLoc() : FD->getLocation();
8276 DefaultedComparisonSynthesizer(S, RD, FD, DCK, BodyLoc).build();
8277 if (!Body.isInvalid())
8278 ExceptSpec.CalledStmt(Body.get());
8280 // FIXME: Can we hold onto this body and just transform it to potentially
8281 // evaluated when we're asked to define the function rather than rebuilding
8282 // it? Either that, or we should only build the bits of the body that we
8283 // need (the expressions, not the statements).
8289 void Sema::CheckDelayedMemberExceptionSpecs() {
8290 decltype(DelayedOverridingExceptionSpecChecks) Overriding;
8291 decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;
8293 std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
8294 std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);
8296 // Perform any deferred checking of exception specifications for virtual
8298 for (auto &Check : Overriding)
8299 CheckOverridingFunctionExceptionSpec(Check.first, Check.second);
8301 // Perform any deferred checking of exception specifications for befriended
8303 for (auto &Check : Equivalent)
8304 CheckEquivalentExceptionSpec(Check.second, Check.first);
8308 /// CRTP base class for visiting operations performed by a special member
8309 /// function (or inherited constructor).
8310 template<typename Derived>
8311 struct SpecialMemberVisitor {
8314 Sema::CXXSpecialMember CSM;
8315 Sema::InheritedConstructorInfo *ICI;
8317 // Properties of the special member, computed for convenience.
8318 bool IsConstructor = false, IsAssignment = false, ConstArg = false;
8320 SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
8321 Sema::InheritedConstructorInfo *ICI)
8322 : S(S), MD(MD), CSM(CSM), ICI(ICI) {
8324 case Sema::CXXDefaultConstructor:
8325 case Sema::CXXCopyConstructor:
8326 case Sema::CXXMoveConstructor:
8327 IsConstructor = true;
8329 case Sema::CXXCopyAssignment:
8330 case Sema::CXXMoveAssignment:
8331 IsAssignment = true;
8333 case Sema::CXXDestructor:
8335 case Sema::CXXInvalid:
8336 llvm_unreachable("invalid special member kind");
8339 if (MD->getNumParams()) {
8340 if (const ReferenceType *RT =
8341 MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
8342 ConstArg = RT->getPointeeType().isConstQualified();
8346 Derived &getDerived() { return static_cast<Derived&>(*this); }
8348 /// Is this a "move" special member?
8349 bool isMove() const {
8350 return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
8353 /// Look up the corresponding special member in the given class.
8354 Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
8355 unsigned Quals, bool IsMutable) {
8356 return lookupCallFromSpecialMember(S, Class, CSM, Quals,
8357 ConstArg && !IsMutable);
8360 /// Look up the constructor for the specified base class to see if it's
8361 /// overridden due to this being an inherited constructor.
8362 Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
8365 assert(CSM == Sema::CXXDefaultConstructor);
8367 cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
8368 if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
8373 /// A base or member subobject.
8374 typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
8376 /// Get the location to use for a subobject in diagnostics.
8377 static SourceLocation getSubobjectLoc(Subobject Subobj) {
8378 // FIXME: For an indirect virtual base, the direct base leading to
8379 // the indirect virtual base would be a more useful choice.
8380 if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
8381 return B->getBaseTypeLoc();
8383 return Subobj.get<FieldDecl*>()->getLocation();
8387 /// Visit all non-virtual (direct) bases.
8388 VisitNonVirtualBases,
8389 /// Visit all direct bases, virtual or not.
8391 /// Visit all non-virtual bases, and all virtual bases if the class
8392 /// is not abstract.
8393 VisitPotentiallyConstructedBases,
8394 /// Visit all direct or virtual bases.
8398 // Visit the bases and members of the class.
8399 bool visit(BasesToVisit Bases) {
8400 CXXRecordDecl *RD = MD->getParent();
8402 if (Bases == VisitPotentiallyConstructedBases)
8403 Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;
8405 for (auto &B : RD->bases())
8406 if ((Bases == VisitDirectBases || !B.isVirtual()) &&
8407 getDerived().visitBase(&B))
8410 if (Bases == VisitAllBases)
8411 for (auto &B : RD->vbases())
8412 if (getDerived().visitBase(&B))
8415 for (auto *F : RD->fields())
8416 if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
8417 getDerived().visitField(F))
8426 struct SpecialMemberDeletionInfo
8427 : SpecialMemberVisitor<SpecialMemberDeletionInfo> {
8432 bool AllFieldsAreConst;
8434 SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
8435 Sema::CXXSpecialMember CSM,
8436 Sema::InheritedConstructorInfo *ICI, bool Diagnose)
8437 : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
8438 Loc(MD->getLocation()), AllFieldsAreConst(true) {}
8440 bool inUnion() const { return MD->getParent()->isUnion(); }
8442 Sema::CXXSpecialMember getEffectiveCSM() {
8443 return ICI ? Sema::CXXInvalid : CSM;
8446 bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);
8448 bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
8449 bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }
8451 bool shouldDeleteForBase(CXXBaseSpecifier *Base);
8452 bool shouldDeleteForField(FieldDecl *FD);
8453 bool shouldDeleteForAllConstMembers();
8455 bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
8457 bool shouldDeleteForSubobjectCall(Subobject Subobj,
8458 Sema::SpecialMemberOverloadResult SMOR,
8459 bool IsDtorCallInCtor);
8461 bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
8465 /// Is the given special member inaccessible when used on the given
8467 bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
8468 CXXMethodDecl *target) {
8469 /// If we're operating on a base class, the object type is the
8470 /// type of this special member.
8472 AccessSpecifier access = target->getAccess();
8473 if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
8474 objectTy = S.Context.getTypeDeclType(MD->getParent());
8475 access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
8477 // If we're operating on a field, the object type is the type of the field.
8479 objectTy = S.Context.getTypeDeclType(target->getParent());
8482 return S.isMemberAccessibleForDeletion(
8483 target->getParent(), DeclAccessPair::make(target, access), objectTy);
8486 /// Check whether we should delete a special member due to the implicit
8487 /// definition containing a call to a special member of a subobject.
8488 bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
8489 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
8490 bool IsDtorCallInCtor) {
8491 CXXMethodDecl *Decl = SMOR.getMethod();
8492 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8496 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
8497 DiagKind = !Decl ? 0 : 1;
8498 else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
8500 else if (!isAccessible(Subobj, Decl))
8502 else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
8503 !Decl->isTrivial()) {
8504 // A member of a union must have a trivial corresponding special member.
8505 // As a weird special case, a destructor call from a union's constructor
8506 // must be accessible and non-deleted, but need not be trivial. Such a
8507 // destructor is never actually called, but is semantically checked as
8517 S.Diag(Field->getLocation(),
8518 diag::note_deleted_special_member_class_subobject)
8519 << getEffectiveCSM() << MD->getParent() << /*IsField*/true
8520 << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
8522 CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
8523 S.Diag(Base->getBeginLoc(),
8524 diag::note_deleted_special_member_class_subobject)
8525 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
8526 << Base->getType() << DiagKind << IsDtorCallInCtor
8527 << /*IsObjCPtr*/false;
8531 S.NoteDeletedFunction(Decl);
8532 // FIXME: Explain inaccessibility if DiagKind == 3.
8538 /// Check whether we should delete a special member function due to having a
8539 /// direct or virtual base class or non-static data member of class type M.
8540 bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
8541 CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
8542 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
8543 bool IsMutable = Field && Field->isMutable();
8545 // C++11 [class.ctor]p5:
8546 // -- any direct or virtual base class, or non-static data member with no
8547 // brace-or-equal-initializer, has class type M (or array thereof) and
8548 // either M has no default constructor or overload resolution as applied
8549 // to M's default constructor results in an ambiguity or in a function
8550 // that is deleted or inaccessible
8551 // C++11 [class.copy]p11, C++11 [class.copy]p23:
8552 // -- a direct or virtual base class B that cannot be copied/moved because
8553 // overload resolution, as applied to B's corresponding special member,
8554 // results in an ambiguity or a function that is deleted or inaccessible
8555 // from the defaulted special member
8556 // C++11 [class.dtor]p5:
8557 // -- any direct or virtual base class [...] has a type with a destructor
8558 // that is deleted or inaccessible
8559 if (!(CSM == Sema::CXXDefaultConstructor &&
8560 Field && Field->hasInClassInitializer()) &&
8561 shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
8565 // C++11 [class.ctor]p5, C++11 [class.copy]p11:
8566 // -- any direct or virtual base class or non-static data member has a
8567 // type with a destructor that is deleted or inaccessible
8568 if (IsConstructor) {
8569 Sema::SpecialMemberOverloadResult SMOR =
8570 S.LookupSpecialMember(Class, Sema::CXXDestructor,
8571 false, false, false, false, false);
8572 if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
8579 bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
8580 FieldDecl *FD, QualType FieldType) {
8581 // The defaulted special functions are defined as deleted if this is a variant
8582 // member with a non-trivial ownership type, e.g., ObjC __strong or __weak
8584 if (!FieldType.hasNonTrivialObjCLifetime())
8587 // Don't make the defaulted default constructor defined as deleted if the
8588 // member has an in-class initializer.
8589 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
8593 auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
8594 S.Diag(FD->getLocation(),
8595 diag::note_deleted_special_member_class_subobject)
8596 << getEffectiveCSM() << ParentClass << /*IsField*/true
8597 << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
8603 /// Check whether we should delete a special member function due to the class
8604 /// having a particular direct or virtual base class.
8605 bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
8606 CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
8607 // If program is correct, BaseClass cannot be null, but if it is, the error
8608 // must be reported elsewhere.
8611 // If we have an inheriting constructor, check whether we're calling an
8612 // inherited constructor instead of a default constructor.
8613 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
8614 if (auto *BaseCtor = SMOR.getMethod()) {
8615 // Note that we do not check access along this path; other than that,
8616 // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
8617 // FIXME: Check that the base has a usable destructor! Sink this into
8618 // shouldDeleteForClassSubobject.
8619 if (BaseCtor->isDeleted() && Diagnose) {
8620 S.Diag(Base->getBeginLoc(),
8621 diag::note_deleted_special_member_class_subobject)
8622 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
8623 << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
8624 << /*IsObjCPtr*/false;
8625 S.NoteDeletedFunction(BaseCtor);
8627 return BaseCtor->isDeleted();
8629 return shouldDeleteForClassSubobject(BaseClass, Base, 0);
8632 /// Check whether we should delete a special member function due to the class
8633 /// having a particular non-static data member.
8634 bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
8635 QualType FieldType = S.Context.getBaseElementType(FD->getType());
8636 CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
8638 if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
8641 if (CSM == Sema::CXXDefaultConstructor) {
8642 // For a default constructor, all references must be initialized in-class
8643 // and, if a union, it must have a non-const member.
8644 if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
8646 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
8647 << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
8650 // C++11 [class.ctor]p5: any non-variant non-static data member of
8651 // const-qualified type (or array thereof) with no
8652 // brace-or-equal-initializer does not have a user-provided default
8654 if (!inUnion() && FieldType.isConstQualified() &&
8655 !FD->hasInClassInitializer() &&
8656 (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
8658 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
8659 << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
8663 if (inUnion() && !FieldType.isConstQualified())
8664 AllFieldsAreConst = false;
8665 } else if (CSM == Sema::CXXCopyConstructor) {
8666 // For a copy constructor, data members must not be of rvalue reference
8668 if (FieldType->isRValueReferenceType()) {
8670 S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
8671 << MD->getParent() << FD << FieldType;
8674 } else if (IsAssignment) {
8675 // For an assignment operator, data members must not be of reference type.
8676 if (FieldType->isReferenceType()) {
8678 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
8679 << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
8682 if (!FieldRecord && FieldType.isConstQualified()) {
8683 // C++11 [class.copy]p23:
8684 // -- a non-static data member of const non-class type (or array thereof)
8686 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
8687 << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
8693 // Some additional restrictions exist on the variant members.
8694 if (!inUnion() && FieldRecord->isUnion() &&
8695 FieldRecord->isAnonymousStructOrUnion()) {
8696 bool AllVariantFieldsAreConst = true;
8698 // FIXME: Handle anonymous unions declared within anonymous unions.
8699 for (auto *UI : FieldRecord->fields()) {
8700 QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
8702 if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
8705 if (!UnionFieldType.isConstQualified())
8706 AllVariantFieldsAreConst = false;
8708 CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
8709 if (UnionFieldRecord &&
8710 shouldDeleteForClassSubobject(UnionFieldRecord, UI,
8711 UnionFieldType.getCVRQualifiers()))
8715 // At least one member in each anonymous union must be non-const
8716 if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
8717 !FieldRecord->field_empty()) {
8719 S.Diag(FieldRecord->getLocation(),
8720 diag::note_deleted_default_ctor_all_const)
8721 << !!ICI << MD->getParent() << /*anonymous union*/1;
8725 // Don't check the implicit member of the anonymous union type.
8726 // This is technically non-conformant, but sanity demands it.
8730 if (shouldDeleteForClassSubobject(FieldRecord, FD,
8731 FieldType.getCVRQualifiers()))
8738 /// C++11 [class.ctor] p5:
8739 /// A defaulted default constructor for a class X is defined as deleted if
8740 /// X is a union and all of its variant members are of const-qualified type.
8741 bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
8742 // This is a silly definition, because it gives an empty union a deleted
8743 // default constructor. Don't do that.
8744 if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
8745 bool AnyFields = false;
8746 for (auto *F : MD->getParent()->fields())
8747 if ((AnyFields = !F->isUnnamedBitfield()))
8752 S.Diag(MD->getParent()->getLocation(),
8753 diag::note_deleted_default_ctor_all_const)
8754 << !!ICI << MD->getParent() << /*not anonymous union*/0;
8760 /// Determine whether a defaulted special member function should be defined as
8761 /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
8762 /// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
8763 bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
8764 InheritedConstructorInfo *ICI,
8766 if (MD->isInvalidDecl())
8768 CXXRecordDecl *RD = MD->getParent();
8769 assert(!RD->isDependentType() && "do deletion after instantiation");
8770 if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
8773 // C++11 [expr.lambda.prim]p19:
8774 // The closure type associated with a lambda-expression has a
8775 // deleted (8.4.3) default constructor and a deleted copy
8776 // assignment operator.
8777 // C++2a adds back these operators if the lambda has no lambda-capture.
8778 if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
8779 (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
8781 Diag(RD->getLocation(), diag::note_lambda_decl);
8785 // For an anonymous struct or union, the copy and assignment special members
8786 // will never be used, so skip the check. For an anonymous union declared at
8787 // namespace scope, the constructor and destructor are used.
8788 if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
8789 RD->isAnonymousStructOrUnion())
8792 // C++11 [class.copy]p7, p18:
8793 // If the class definition declares a move constructor or move assignment
8794 // operator, an implicitly declared copy constructor or copy assignment
8795 // operator is defined as deleted.
8796 if (MD->isImplicit() &&
8797 (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
8798 CXXMethodDecl *UserDeclaredMove = nullptr;
8800 // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
8801 // deletion of the corresponding copy operation, not both copy operations.
8802 // MSVC 2015 has adopted the standards conforming behavior.
8803 bool DeletesOnlyMatchingCopy =
8804 getLangOpts().MSVCCompat &&
8805 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
8807 if (RD->hasUserDeclaredMoveConstructor() &&
8808 (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
8809 if (!Diagnose) return true;
8811 // Find any user-declared move constructor.
8812 for (auto *I : RD->ctors()) {
8813 if (I->isMoveConstructor()) {
8814 UserDeclaredMove = I;
8818 assert(UserDeclaredMove);
8819 } else if (RD->hasUserDeclaredMoveAssignment() &&
8820 (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
8821 if (!Diagnose) return true;
8823 // Find any user-declared move assignment operator.
8824 for (auto *I : RD->methods()) {
8825 if (I->isMoveAssignmentOperator()) {
8826 UserDeclaredMove = I;
8830 assert(UserDeclaredMove);
8833 if (UserDeclaredMove) {
8834 Diag(UserDeclaredMove->getLocation(),
8835 diag::note_deleted_copy_user_declared_move)
8836 << (CSM == CXXCopyAssignment) << RD
8837 << UserDeclaredMove->isMoveAssignmentOperator();
8842 // Do access control from the special member function
8843 ContextRAII MethodContext(*this, MD);
8845 // C++11 [class.dtor]p5:
8846 // -- for a virtual destructor, lookup of the non-array deallocation function
8847 // results in an ambiguity or in a function that is deleted or inaccessible
8848 if (CSM == CXXDestructor && MD->isVirtual()) {
8849 FunctionDecl *OperatorDelete = nullptr;
8850 DeclarationName Name =
8851 Context.DeclarationNames.getCXXOperatorName(OO_Delete);
8852 if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
8853 OperatorDelete, /*Diagnose*/false)) {
8855 Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
8860 SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);
8862 // Per DR1611, do not consider virtual bases of constructors of abstract
8863 // classes, since we are not going to construct them.
8864 // Per DR1658, do not consider virtual bases of destructors of abstract
8866 // Per DR2180, for assignment operators we only assign (and thus only
8867 // consider) direct bases.
8868 if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
8869 : SMI.VisitPotentiallyConstructedBases))
8872 if (SMI.shouldDeleteForAllConstMembers())
8875 if (getLangOpts().CUDA) {
8876 // We should delete the special member in CUDA mode if target inference
8878 // For inherited constructors (non-null ICI), CSM may be passed so that MD
8879 // is treated as certain special member, which may not reflect what special
8880 // member MD really is. However inferCUDATargetForImplicitSpecialMember
8881 // expects CSM to match MD, therefore recalculate CSM.
8882 assert(ICI || CSM == getSpecialMember(MD));
8885 RealCSM = getSpecialMember(MD);
8887 return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
8888 SMI.ConstArg, Diagnose);
8894 void Sema::DiagnoseDeletedDefaultedFunction(FunctionDecl *FD) {
8895 DefaultedFunctionKind DFK = getDefaultedFunctionKind(FD);
8896 assert(DFK && "not a defaultable function");
8897 assert(FD->isDefaulted() && FD->isDeleted() && "not defaulted and deleted");
8899 if (DFK.isSpecialMember()) {
8900 ShouldDeleteSpecialMember(cast<CXXMethodDecl>(FD), DFK.asSpecialMember(),
8901 nullptr, /*Diagnose=*/true);
8903 DefaultedComparisonAnalyzer(
8904 *this, cast<CXXRecordDecl>(FD->getLexicalDeclContext()), FD,
8905 DFK.asComparison(), DefaultedComparisonAnalyzer::ExplainDeleted)
8910 /// Perform lookup for a special member of the specified kind, and determine
8911 /// whether it is trivial. If the triviality can be determined without the
8912 /// lookup, skip it. This is intended for use when determining whether a
8913 /// special member of a containing object is trivial, and thus does not ever
8914 /// perform overload resolution for default constructors.
8916 /// If \p Selected is not \c NULL, \c *Selected will be filled in with the
8917 /// member that was most likely to be intended to be trivial, if any.
8919 /// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
8920 /// determine whether the special member is trivial.
8921 static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
8922 Sema::CXXSpecialMember CSM, unsigned Quals,
8924 Sema::TrivialABIHandling TAH,
8925 CXXMethodDecl **Selected) {
8927 *Selected = nullptr;
8930 case Sema::CXXInvalid:
8931 llvm_unreachable("not a special member");
8933 case Sema::CXXDefaultConstructor:
8934 // C++11 [class.ctor]p5:
8935 // A default constructor is trivial if:
8936 // - all the [direct subobjects] have trivial default constructors
8938 // Note, no overload resolution is performed in this case.
8939 if (RD->hasTrivialDefaultConstructor())
8943 // If there's a default constructor which could have been trivial, dig it
8944 // out. Otherwise, if there's any user-provided default constructor, point
8945 // to that as an example of why there's not a trivial one.
8946 CXXConstructorDecl *DefCtor = nullptr;
8947 if (RD->needsImplicitDefaultConstructor())
8948 S.DeclareImplicitDefaultConstructor(RD);
8949 for (auto *CI : RD->ctors()) {
8950 if (!CI->isDefaultConstructor())
8953 if (!DefCtor->isUserProvided())
8957 *Selected = DefCtor;
8962 case Sema::CXXDestructor:
8963 // C++11 [class.dtor]p5:
8964 // A destructor is trivial if:
8965 // - all the direct [subobjects] have trivial destructors
8966 if (RD->hasTrivialDestructor() ||
8967 (TAH == Sema::TAH_ConsiderTrivialABI &&
8968 RD->hasTrivialDestructorForCall()))
8972 if (RD->needsImplicitDestructor())
8973 S.DeclareImplicitDestructor(RD);
8974 *Selected = RD->getDestructor();
8979 case Sema::CXXCopyConstructor:
8980 // C++11 [class.copy]p12:
8981 // A copy constructor is trivial if:
8982 // - the constructor selected to copy each direct [subobject] is trivial
8983 if (RD->hasTrivialCopyConstructor() ||
8984 (TAH == Sema::TAH_ConsiderTrivialABI &&
8985 RD->hasTrivialCopyConstructorForCall())) {
8986 if (Quals == Qualifiers::Const)
8987 // We must either select the trivial copy constructor or reach an
8988 // ambiguity; no need to actually perform overload resolution.
8990 } else if (!Selected) {
8993 // In C++98, we are not supposed to perform overload resolution here, but we
8994 // treat that as a language defect, as suggested on cxx-abi-dev, to treat
8995 // cases like B as having a non-trivial copy constructor:
8996 // struct A { template<typename T> A(T&); };
8997 // struct B { mutable A a; };
8998 goto NeedOverloadResolution;
9000 case Sema::CXXCopyAssignment:
9001 // C++11 [class.copy]p25:
9002 // A copy assignment operator is trivial if:
9003 // - the assignment operator selected to copy each direct [subobject] is
9005 if (RD->hasTrivialCopyAssignment()) {
9006 if (Quals == Qualifiers::Const)
9008 } else if (!Selected) {
9011 // In C++98, we are not supposed to perform overload resolution here, but we
9012 // treat that as a language defect.
9013 goto NeedOverloadResolution;
9015 case Sema::CXXMoveConstructor:
9016 case Sema::CXXMoveAssignment:
9017 NeedOverloadResolution:
9018 Sema::SpecialMemberOverloadResult SMOR =
9019 lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);
9021 // The standard doesn't describe how to behave if the lookup is ambiguous.
9022 // We treat it as not making the member non-trivial, just like the standard
9023 // mandates for the default constructor. This should rarely matter, because
9024 // the member will also be deleted.
9025 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
9028 if (!SMOR.getMethod()) {
9029 assert(SMOR.getKind() ==
9030 Sema::SpecialMemberOverloadResult::NoMemberOrDeleted);
9034 // We deliberately don't check if we found a deleted special member. We're
9037 *Selected = SMOR.getMethod();
9039 if (TAH == Sema::TAH_ConsiderTrivialABI &&
9040 (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
9041 return SMOR.getMethod()->isTrivialForCall();
9042 return SMOR.getMethod()->isTrivial();
9045 llvm_unreachable("unknown special method kind");
9048 static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
9049 for (auto *CI : RD->ctors())
9050 if (!CI->isImplicit())
9053 // Look for constructor templates.
9054 typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
9055 for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
9056 if (CXXConstructorDecl *CD =
9057 dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
9064 /// The kind of subobject we are checking for triviality. The values of this
9065 /// enumeration are used in diagnostics.
9066 enum TrivialSubobjectKind {
9067 /// The subobject is a base class.
9069 /// The subobject is a non-static data member.
9071 /// The object is actually the complete object.
9075 /// Check whether the special member selected for a given type would be trivial.
9076 static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
9077 QualType SubType, bool ConstRHS,
9078 Sema::CXXSpecialMember CSM,
9079 TrivialSubobjectKind Kind,
9080 Sema::TrivialABIHandling TAH, bool Diagnose) {
9081 CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
9085 CXXMethodDecl *Selected;
9086 if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
9087 ConstRHS, TAH, Diagnose ? &Selected : nullptr))
9094 if (!Selected && CSM == Sema::CXXDefaultConstructor) {
9095 S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
9096 << Kind << SubType.getUnqualifiedType();
9097 if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
9098 S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
9099 } else if (!Selected)
9100 S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
9101 << Kind << SubType.getUnqualifiedType() << CSM << SubType;
9102 else if (Selected->isUserProvided()) {
9103 if (Kind == TSK_CompleteObject)
9104 S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
9105 << Kind << SubType.getUnqualifiedType() << CSM;
9107 S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
9108 << Kind << SubType.getUnqualifiedType() << CSM;
9109 S.Diag(Selected->getLocation(), diag::note_declared_at);
9112 if (Kind != TSK_CompleteObject)
9113 S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
9114 << Kind << SubType.getUnqualifiedType() << CSM;
9116 // Explain why the defaulted or deleted special member isn't trivial.
9117 S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
9125 /// Check whether the members of a class type allow a special member to be
9127 static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
9128 Sema::CXXSpecialMember CSM,
9130 Sema::TrivialABIHandling TAH,
9132 for (const auto *FI : RD->fields()) {
9133 if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
9136 QualType FieldType = S.Context.getBaseElementType(FI->getType());
9138 // Pretend anonymous struct or union members are members of this class.
9139 if (FI->isAnonymousStructOrUnion()) {
9140 if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
9141 CSM, ConstArg, TAH, Diagnose))
9146 // C++11 [class.ctor]p5:
9147 // A default constructor is trivial if [...]
9148 // -- no non-static data member of its class has a
9149 // brace-or-equal-initializer
9150 if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
9152 S.Diag(FI->getLocation(), diag::note_nontrivial_in_class_init) << FI;
9156 // Objective C ARC 4.3.5:
9157 // [...] nontrivally ownership-qualified types are [...] not trivially
9158 // default constructible, copy constructible, move constructible, copy
9159 // assignable, move assignable, or destructible [...]
9160 if (FieldType.hasNonTrivialObjCLifetime()) {
9162 S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
9163 << RD << FieldType.getObjCLifetime();
9167 bool ConstRHS = ConstArg && !FI->isMutable();
9168 if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
9169 CSM, TSK_Field, TAH, Diagnose))
9176 /// Diagnose why the specified class does not have a trivial special member of
9178 void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
9179 QualType Ty = Context.getRecordType(RD);
9181 bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
9182 checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
9183 TSK_CompleteObject, TAH_IgnoreTrivialABI,
9187 /// Determine whether a defaulted or deleted special member function is trivial,
9188 /// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
9189 /// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
9190 bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
9191 TrivialABIHandling TAH, bool Diagnose) {
9192 assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough");
9194 CXXRecordDecl *RD = MD->getParent();
9196 bool ConstArg = false;
9198 // C++11 [class.copy]p12, p25: [DR1593]
9199 // A [special member] is trivial if [...] its parameter-type-list is
9200 // equivalent to the parameter-type-list of an implicit declaration [...]
9202 case CXXDefaultConstructor:
9204 // Trivial default constructors and destructors cannot have parameters.
9207 case CXXCopyConstructor:
9208 case CXXCopyAssignment: {
9209 // Trivial copy operations always have const, non-volatile parameter types.
9211 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9212 const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
9213 if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
9215 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9216 << Param0->getSourceRange() << Param0->getType()
9217 << Context.getLValueReferenceType(
9218 Context.getRecordType(RD).withConst());
9224 case CXXMoveConstructor:
9225 case CXXMoveAssignment: {
9226 // Trivial move operations always have non-cv-qualified parameters.
9227 const ParmVarDecl *Param0 = MD->getParamDecl(0);
9228 const RValueReferenceType *RT =
9229 Param0->getType()->getAs<RValueReferenceType>();
9230 if (!RT || RT->getPointeeType().getCVRQualifiers()) {
9232 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
9233 << Param0->getSourceRange() << Param0->getType()
9234 << Context.getRValueReferenceType(Context.getRecordType(RD));
9241 llvm_unreachable("not a special member");
9244 if (MD->getMinRequiredArguments() < MD->getNumParams()) {
9246 Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
9247 diag::note_nontrivial_default_arg)
9248 << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
9251 if (MD->isVariadic()) {
9253 Diag(MD->getLocation(), diag::note_nontrivial_variadic);
9257 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9258 // A copy/move [constructor or assignment operator] is trivial if
9259 // -- the [member] selected to copy/move each direct base class subobject
9262 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9263 // A [default constructor or destructor] is trivial if
9264 // -- all the direct base classes have trivial [default constructors or
9266 for (const auto &BI : RD->bases())
9267 if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
9268 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
9271 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
9272 // A copy/move [constructor or assignment operator] for a class X is
9274 // -- for each non-static data member of X that is of class type (or array
9275 // thereof), the constructor selected to copy/move that member is
9278 // C++11 [class.copy]p12, C++11 [class.copy]p25:
9279 // A [default constructor or destructor] is trivial if
9280 // -- for all of the non-static data members of its class that are of class
9281 // type (or array thereof), each such class has a trivial [default
9282 // constructor or destructor]
9283 if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
9286 // C++11 [class.dtor]p5:
9287 // A destructor is trivial if [...]
9288 // -- the destructor is not virtual
9289 if (CSM == CXXDestructor && MD->isVirtual()) {
9291 Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
9295 // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
9296 // A [special member] for class X is trivial if [...]
9297 // -- class X has no virtual functions and no virtual base classes
9298 if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
9302 if (RD->getNumVBases()) {
9303 // Check for virtual bases. We already know that the corresponding
9304 // member in all bases is trivial, so vbases must all be direct.
9305 CXXBaseSpecifier &BS = *RD->vbases_begin();
9306 assert(BS.isVirtual());
9307 Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
9311 // Must have a virtual method.
9312 for (const auto *MI : RD->methods()) {
9313 if (MI->isVirtual()) {
9314 SourceLocation MLoc = MI->getBeginLoc();
9315 Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
9320 llvm_unreachable("dynamic class with no vbases and no virtual functions");
9323 // Looks like it's trivial!
9328 struct FindHiddenVirtualMethod {
9330 CXXMethodDecl *Method;
9331 llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
9332 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9335 /// Check whether any most overridden method from MD in Methods
9336 static bool CheckMostOverridenMethods(
9337 const CXXMethodDecl *MD,
9338 const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
9339 if (MD->size_overridden_methods() == 0)
9340 return Methods.count(MD->getCanonicalDecl());
9341 for (const CXXMethodDecl *O : MD->overridden_methods())
9342 if (CheckMostOverridenMethods(O, Methods))
9348 /// Member lookup function that determines whether a given C++
9349 /// method overloads virtual methods in a base class without overriding any,
9350 /// to be used with CXXRecordDecl::lookupInBases().
9351 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
9352 RecordDecl *BaseRecord =
9353 Specifier->getType()->castAs<RecordType>()->getDecl();
9355 DeclarationName Name = Method->getDeclName();
9356 assert(Name.getNameKind() == DeclarationName::Identifier);
9358 bool foundSameNameMethod = false;
9359 SmallVector<CXXMethodDecl *, 8> overloadedMethods;
9360 for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty();
9361 Path.Decls = Path.Decls.slice(1)) {
9362 NamedDecl *D = Path.Decls.front();
9363 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
9364 MD = MD->getCanonicalDecl();
9365 foundSameNameMethod = true;
9366 // Interested only in hidden virtual methods.
9367 if (!MD->isVirtual())
9369 // If the method we are checking overrides a method from its base
9370 // don't warn about the other overloaded methods. Clang deviates from
9371 // GCC by only diagnosing overloads of inherited virtual functions that
9372 // do not override any other virtual functions in the base. GCC's
9373 // -Woverloaded-virtual diagnoses any derived function hiding a virtual
9374 // function from a base class. These cases may be better served by a
9375 // warning (not specific to virtual functions) on call sites when the
9376 // call would select a different function from the base class, were it
9378 // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
9379 if (!S->IsOverload(Method, MD, false))
9381 // Collect the overload only if its hidden.
9382 if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
9383 overloadedMethods.push_back(MD);
9387 if (foundSameNameMethod)
9388 OverloadedMethods.append(overloadedMethods.begin(),
9389 overloadedMethods.end());
9390 return foundSameNameMethod;
9393 } // end anonymous namespace
9395 /// Add the most overriden methods from MD to Methods
9396 static void AddMostOverridenMethods(const CXXMethodDecl *MD,
9397 llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
9398 if (MD->size_overridden_methods() == 0)
9399 Methods.insert(MD->getCanonicalDecl());
9401 for (const CXXMethodDecl *O : MD->overridden_methods())
9402 AddMostOverridenMethods(O, Methods);
9405 /// Check if a method overloads virtual methods in a base class without
9407 void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
9408 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9409 if (!MD->getDeclName().isIdentifier())
9412 CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
9413 /*bool RecordPaths=*/false,
9414 /*bool DetectVirtual=*/false);
9415 FindHiddenVirtualMethod FHVM;
9419 // Keep the base methods that were overridden or introduced in the subclass
9420 // by 'using' in a set. A base method not in this set is hidden.
9421 CXXRecordDecl *DC = MD->getParent();
9422 DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
9423 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
9425 if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
9426 ND = shad->getTargetDecl();
9427 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
9428 AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
9431 if (DC->lookupInBases(FHVM, Paths))
9432 OverloadedMethods = FHVM.OverloadedMethods;
9435 void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
9436 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
9437 for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
9438 CXXMethodDecl *overloadedMD = OverloadedMethods[i];
9439 PartialDiagnostic PD = PDiag(
9440 diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
9441 HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
9442 Diag(overloadedMD->getLocation(), PD);
9446 /// Diagnose methods which overload virtual methods in a base class
9447 /// without overriding any.
9448 void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
9449 if (MD->isInvalidDecl())
9452 if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
9455 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
9456 FindHiddenVirtualMethods(MD, OverloadedMethods);
9457 if (!OverloadedMethods.empty()) {
9458 Diag(MD->getLocation(), diag::warn_overloaded_virtual)
9459 << MD << (OverloadedMethods.size() > 1);
9461 NoteHiddenVirtualMethods(MD, OverloadedMethods);
9465 void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
9466 auto PrintDiagAndRemoveAttr = [&]() {
9467 // No diagnostics if this is a template instantiation.
9468 if (!isTemplateInstantiation(RD.getTemplateSpecializationKind()))
9469 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
9470 diag::ext_cannot_use_trivial_abi) << &RD;
9471 RD.dropAttr<TrivialABIAttr>();
9474 // Ill-formed if the struct has virtual functions.
9475 if (RD.isPolymorphic()) {
9476 PrintDiagAndRemoveAttr();
9480 for (const auto &B : RD.bases()) {
9481 // Ill-formed if the base class is non-trivial for the purpose of calls or a
9483 if ((!B.getType()->isDependentType() &&
9484 !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) ||
9486 PrintDiagAndRemoveAttr();
9491 for (const auto *FD : RD.fields()) {
9492 // Ill-formed if the field is an ObjectiveC pointer or of a type that is
9493 // non-trivial for the purpose of calls.
9494 QualType FT = FD->getType();
9495 if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
9496 PrintDiagAndRemoveAttr();
9500 if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
9501 if (!RT->isDependentType() &&
9502 !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
9503 PrintDiagAndRemoveAttr();
9509 void Sema::ActOnFinishCXXMemberSpecification(
9510 Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
9511 SourceLocation RBrac, const ParsedAttributesView &AttrList) {
9515 AdjustDeclIfTemplate(TagDecl);
9517 for (const ParsedAttr &AL : AttrList) {
9518 if (AL.getKind() != ParsedAttr::AT_Visibility)
9521 Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
9524 ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
9525 // strict aliasing violation!
9526 reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
9527 FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
9529 CheckCompletedCXXClass(S, cast<CXXRecordDecl>(TagDecl));
9532 /// Find the equality comparison functions that should be implicitly declared
9533 /// in a given class definition, per C++2a [class.compare.default]p3.
9534 static void findImplicitlyDeclaredEqualityComparisons(
9535 ASTContext &Ctx, CXXRecordDecl *RD,
9536 llvm::SmallVectorImpl<FunctionDecl *> &Spaceships) {
9537 DeclarationName EqEq = Ctx.DeclarationNames.getCXXOperatorName(OO_EqualEqual);
9538 if (!RD->lookup(EqEq).empty())
9539 // Member operator== explicitly declared: no implicit operator==s.
9542 // Traverse friends looking for an '==' or a '<=>'.
9543 for (FriendDecl *Friend : RD->friends()) {
9544 FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(Friend->getFriendDecl());
9547 if (FD->getOverloadedOperator() == OO_EqualEqual) {
9548 // Friend operator== explicitly declared: no implicit operator==s.
9553 if (FD->getOverloadedOperator() == OO_Spaceship &&
9554 FD->isExplicitlyDefaulted())
9555 Spaceships.push_back(FD);
9558 // Look for members named 'operator<=>'.
9559 DeclarationName Cmp = Ctx.DeclarationNames.getCXXOperatorName(OO_Spaceship);
9560 for (NamedDecl *ND : RD->lookup(Cmp)) {
9561 // Note that we could find a non-function here (either a function template
9562 // or a using-declaration). Neither case results in an implicit
9564 if (auto *FD = dyn_cast<FunctionDecl>(ND))
9565 if (FD->isExplicitlyDefaulted())
9566 Spaceships.push_back(FD);
9570 /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
9571 /// special functions, such as the default constructor, copy
9572 /// constructor, or destructor, to the given C++ class (C++
9573 /// [special]p1). This routine can only be executed just before the
9574 /// definition of the class is complete.
9575 void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
9576 if (ClassDecl->needsImplicitDefaultConstructor()) {
9577 ++getASTContext().NumImplicitDefaultConstructors;
9579 if (ClassDecl->hasInheritedConstructor())
9580 DeclareImplicitDefaultConstructor(ClassDecl);
9583 if (ClassDecl->needsImplicitCopyConstructor()) {
9584 ++getASTContext().NumImplicitCopyConstructors;
9586 // If the properties or semantics of the copy constructor couldn't be
9587 // determined while the class was being declared, force a declaration
9589 if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
9590 ClassDecl->hasInheritedConstructor())
9591 DeclareImplicitCopyConstructor(ClassDecl);
9592 // For the MS ABI we need to know whether the copy ctor is deleted. A
9593 // prerequisite for deleting the implicit copy ctor is that the class has a
9594 // move ctor or move assignment that is either user-declared or whose
9595 // semantics are inherited from a subobject. FIXME: We should provide a more
9596 // direct way for CodeGen to ask whether the constructor was deleted.
9597 else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
9598 (ClassDecl->hasUserDeclaredMoveConstructor() ||
9599 ClassDecl->needsOverloadResolutionForMoveConstructor() ||
9600 ClassDecl->hasUserDeclaredMoveAssignment() ||
9601 ClassDecl->needsOverloadResolutionForMoveAssignment()))
9602 DeclareImplicitCopyConstructor(ClassDecl);
9605 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveConstructor()) {
9606 ++getASTContext().NumImplicitMoveConstructors;
9608 if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
9609 ClassDecl->hasInheritedConstructor())
9610 DeclareImplicitMoveConstructor(ClassDecl);
9613 if (ClassDecl->needsImplicitCopyAssignment()) {
9614 ++getASTContext().NumImplicitCopyAssignmentOperators;
9616 // If we have a dynamic class, then the copy assignment operator may be
9617 // virtual, so we have to declare it immediately. This ensures that, e.g.,
9618 // it shows up in the right place in the vtable and that we diagnose
9619 // problems with the implicit exception specification.
9620 if (ClassDecl->isDynamicClass() ||
9621 ClassDecl->needsOverloadResolutionForCopyAssignment() ||
9622 ClassDecl->hasInheritedAssignment())
9623 DeclareImplicitCopyAssignment(ClassDecl);
9626 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
9627 ++getASTContext().NumImplicitMoveAssignmentOperators;
9629 // Likewise for the move assignment operator.
9630 if (ClassDecl->isDynamicClass() ||
9631 ClassDecl->needsOverloadResolutionForMoveAssignment() ||
9632 ClassDecl->hasInheritedAssignment())
9633 DeclareImplicitMoveAssignment(ClassDecl);
9636 if (ClassDecl->needsImplicitDestructor()) {
9637 ++getASTContext().NumImplicitDestructors;
9639 // If we have a dynamic class, then the destructor may be virtual, so we
9640 // have to declare the destructor immediately. This ensures that, e.g., it
9641 // shows up in the right place in the vtable and that we diagnose problems
9642 // with the implicit exception specification.
9643 if (ClassDecl->isDynamicClass() ||
9644 ClassDecl->needsOverloadResolutionForDestructor())
9645 DeclareImplicitDestructor(ClassDecl);
9648 // C++2a [class.compare.default]p3:
9649 // If the member-specification does not explicitly declare any member or
9650 // friend named operator==, an == operator function is declared implicitly
9651 // for each defaulted three-way comparison operator function defined in the
9652 // member-specification
9653 // FIXME: Consider doing this lazily.
9654 if (getLangOpts().CPlusPlus2a) {
9655 llvm::SmallVector<FunctionDecl*, 4> DefaultedSpaceships;
9656 findImplicitlyDeclaredEqualityComparisons(Context, ClassDecl,
9657 DefaultedSpaceships);
9658 for (auto *FD : DefaultedSpaceships)
9659 DeclareImplicitEqualityComparison(ClassDecl, FD);
9663 unsigned Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) {
9667 // The order of template parameters is not important here. All names
9668 // get added to the same scope.
9669 SmallVector<TemplateParameterList *, 4> ParameterLists;
9671 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
9672 D = TD->getTemplatedDecl();
9674 if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
9675 ParameterLists.push_back(PSD->getTemplateParameters());
9677 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
9678 for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
9679 ParameterLists.push_back(DD->getTemplateParameterList(i));
9681 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
9682 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
9683 ParameterLists.push_back(FTD->getTemplateParameters());
9687 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
9688 for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
9689 ParameterLists.push_back(TD->getTemplateParameterList(i));
9691 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
9692 if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
9693 ParameterLists.push_back(CTD->getTemplateParameters());
9698 for (TemplateParameterList *Params : ParameterLists) {
9699 if (Params->size() > 0)
9700 // Ignore explicit specializations; they don't contribute to the template
9703 for (NamedDecl *Param : *Params) {
9704 if (Param->getDeclName()) {
9706 IdResolver.AddDecl(Param);
9714 void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
9715 if (!RecordD) return;
9716 AdjustDeclIfTemplate(RecordD);
9717 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
9718 PushDeclContext(S, Record);
9721 void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
9722 if (!RecordD) return;
9726 /// This is used to implement the constant expression evaluation part of the
9727 /// attribute enable_if extension. There is nothing in standard C++ which would
9728 /// require reentering parameters.
9729 void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
9734 if (Param->getDeclName())
9735 IdResolver.AddDecl(Param);
9738 /// ActOnStartDelayedCXXMethodDeclaration - We have completed
9739 /// parsing a top-level (non-nested) C++ class, and we are now
9740 /// parsing those parts of the given Method declaration that could
9741 /// not be parsed earlier (C++ [class.mem]p2), such as default
9742 /// arguments. This action should enter the scope of the given
9743 /// Method declaration as if we had just parsed the qualified method
9744 /// name. However, it should not bring the parameters into scope;
9745 /// that will be performed by ActOnDelayedCXXMethodParameter.
9746 void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
9749 /// ActOnDelayedCXXMethodParameter - We've already started a delayed
9750 /// C++ method declaration. We're (re-)introducing the given
9751 /// function parameter into scope for use in parsing later parts of
9752 /// the method declaration. For example, we could see an
9753 /// ActOnParamDefaultArgument event for this parameter.
9754 void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
9758 ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
9760 // If this parameter has an unparsed default argument, clear it out
9761 // to make way for the parsed default argument.
9762 if (Param->hasUnparsedDefaultArg())
9763 Param->setDefaultArg(nullptr);
9766 if (Param->getDeclName())
9767 IdResolver.AddDecl(Param);
9770 /// ActOnFinishDelayedCXXMethodDeclaration - We have finished
9771 /// processing the delayed method declaration for Method. The method
9772 /// declaration is now considered finished. There may be a separate
9773 /// ActOnStartOfFunctionDef action later (not necessarily
9774 /// immediately!) for this method, if it was also defined inside the
9776 void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
9780 AdjustDeclIfTemplate(MethodD);
9782 FunctionDecl *Method = cast<FunctionDecl>(MethodD);
9784 // Now that we have our default arguments, check the constructor
9785 // again. It could produce additional diagnostics or affect whether
9786 // the class has implicitly-declared destructors, among other
9788 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
9789 CheckConstructor(Constructor);
9791 // Check the default arguments, which we may have added.
9792 if (!Method->isInvalidDecl())
9793 CheckCXXDefaultArguments(Method);
9796 // Emit the given diagnostic for each non-address-space qualifier.
9797 // Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
9798 static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
9799 const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
9800 if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
9801 bool DiagOccured = false;
9802 FTI.MethodQualifiers->forEachQualifier(
9803 [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
9804 SourceLocation SL) {
9805 // This diagnostic should be emitted on any qualifier except an addr
9806 // space qualifier. However, forEachQualifier currently doesn't visit
9807 // addr space qualifiers, so there's no way to write this condition
9808 // right now; we just diagnose on everything.
9809 S.Diag(SL, DiagID) << QualName << SourceRange(SL);
9817 /// CheckConstructorDeclarator - Called by ActOnDeclarator to check
9818 /// the well-formedness of the constructor declarator @p D with type @p
9819 /// R. If there are any errors in the declarator, this routine will
9820 /// emit diagnostics and set the invalid bit to true. In any case, the type
9821 /// will be updated to reflect a well-formed type for the constructor and
9823 QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
9825 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
9827 // C++ [class.ctor]p3:
9828 // A constructor shall not be virtual (10.3) or static (9.4). A
9829 // constructor can be invoked for a const, volatile or const
9830 // volatile object. A constructor shall not be declared const,
9831 // volatile, or const volatile (9.3.2).
9833 if (!D.isInvalidType())
9834 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
9835 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
9836 << SourceRange(D.getIdentifierLoc());
9839 if (SC == SC_Static) {
9840 if (!D.isInvalidType())
9841 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
9842 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
9843 << SourceRange(D.getIdentifierLoc());
9848 if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
9849 diagnoseIgnoredQualifiers(
9850 diag::err_constructor_return_type, TypeQuals, SourceLocation(),
9851 D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
9852 D.getDeclSpec().getRestrictSpecLoc(),
9853 D.getDeclSpec().getAtomicSpecLoc());
9857 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);
9859 // C++0x [class.ctor]p4:
9860 // A constructor shall not be declared with a ref-qualifier.
9861 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
9862 if (FTI.hasRefQualifier()) {
9863 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
9864 << FTI.RefQualifierIsLValueRef
9865 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
9869 // Rebuild the function type "R" without any type qualifiers (in
9870 // case any of the errors above fired) and with "void" as the
9871 // return type, since constructors don't have return types.
9872 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
9873 if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
9876 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
9877 EPI.TypeQuals = Qualifiers();
9878 EPI.RefQualifier = RQ_None;
9880 return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
9883 /// CheckConstructor - Checks a fully-formed constructor for
9884 /// well-formedness, issuing any diagnostics required. Returns true if
9885 /// the constructor declarator is invalid.
9886 void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
9887 CXXRecordDecl *ClassDecl
9888 = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
9890 return Constructor->setInvalidDecl();
9892 // C++ [class.copy]p3:
9893 // A declaration of a constructor for a class X is ill-formed if
9894 // its first parameter is of type (optionally cv-qualified) X and
9895 // either there are no other parameters or else all other
9896 // parameters have default arguments.
9897 if (!Constructor->isInvalidDecl() &&
9898 ((Constructor->getNumParams() == 1) ||
9899 (Constructor->getNumParams() > 1 &&
9900 Constructor->getParamDecl(1)->hasDefaultArg())) &&
9901 Constructor->getTemplateSpecializationKind()
9902 != TSK_ImplicitInstantiation) {
9903 QualType ParamType = Constructor->getParamDecl(0)->getType();
9904 QualType ClassTy = Context.getTagDeclType(ClassDecl);
9905 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
9906 SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
9907 const char *ConstRef
9908 = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
9910 Diag(ParamLoc, diag::err_constructor_byvalue_arg)
9911 << FixItHint::CreateInsertion(ParamLoc, ConstRef);
9913 // FIXME: Rather that making the constructor invalid, we should endeavor
9915 Constructor->setInvalidDecl();
9920 /// CheckDestructor - Checks a fully-formed destructor definition for
9921 /// well-formedness, issuing any diagnostics required. Returns true
9923 bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
9924 CXXRecordDecl *RD = Destructor->getParent();
9926 if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
9929 if (!Destructor->isImplicit())
9930 Loc = Destructor->getLocation();
9932 Loc = RD->getLocation();
9934 // If we have a virtual destructor, look up the deallocation function
9935 if (FunctionDecl *OperatorDelete =
9936 FindDeallocationFunctionForDestructor(Loc, RD)) {
9937 Expr *ThisArg = nullptr;
9939 // If the notional 'delete this' expression requires a non-trivial
9940 // conversion from 'this' to the type of a destroying operator delete's
9941 // first parameter, perform that conversion now.
9942 if (OperatorDelete->isDestroyingOperatorDelete()) {
9943 QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
9944 if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
9945 // C++ [class.dtor]p13:
9946 // ... as if for the expression 'delete this' appearing in a
9947 // non-virtual destructor of the destructor's class.
9948 ContextRAII SwitchContext(*this, Destructor);
9950 ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
9951 assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?");
9952 This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
9953 if (This.isInvalid()) {
9954 // FIXME: Register this as a context note so that it comes out
9955 // in the right order.
9956 Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
9959 ThisArg = This.get();
9963 DiagnoseUseOfDecl(OperatorDelete, Loc);
9964 MarkFunctionReferenced(Loc, OperatorDelete);
9965 Destructor->setOperatorDelete(OperatorDelete, ThisArg);
9972 /// CheckDestructorDeclarator - Called by ActOnDeclarator to check
9973 /// the well-formednes of the destructor declarator @p D with type @p
9974 /// R. If there are any errors in the declarator, this routine will
9975 /// emit diagnostics and set the declarator to invalid. Even if this happens,
9976 /// will be updated to reflect a well-formed type for the destructor and
9978 QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
9980 // C++ [class.dtor]p1:
9981 // [...] A typedef-name that names a class is a class-name
9982 // (7.1.3); however, a typedef-name that names a class shall not
9983 // be used as the identifier in the declarator for a destructor
9985 QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
9986 if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
9987 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
9988 << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
9989 else if (const TemplateSpecializationType *TST =
9990 DeclaratorType->getAs<TemplateSpecializationType>())
9991 if (TST->isTypeAlias())
9992 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
9993 << DeclaratorType << 1;
9995 // C++ [class.dtor]p2:
9996 // A destructor is used to destroy objects of its class type. A
9997 // destructor takes no parameters, and no return type can be
9998 // specified for it (not even void). The address of a destructor
9999 // shall not be taken. A destructor shall not be static. A
10000 // destructor can be invoked for a const, volatile or const
10001 // volatile object. A destructor shall not be declared const,
10002 // volatile or const volatile (9.3.2).
10003 if (SC == SC_Static) {
10004 if (!D.isInvalidType())
10005 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
10006 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10007 << SourceRange(D.getIdentifierLoc())
10008 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
10012 if (!D.isInvalidType()) {
10013 // Destructors don't have return types, but the parser will
10014 // happily parse something like:
10020 // The return type will be eliminated later.
10021 if (D.getDeclSpec().hasTypeSpecifier())
10022 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
10023 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
10024 << SourceRange(D.getIdentifierLoc());
10025 else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
10026 diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
10028 D.getDeclSpec().getConstSpecLoc(),
10029 D.getDeclSpec().getVolatileSpecLoc(),
10030 D.getDeclSpec().getRestrictSpecLoc(),
10031 D.getDeclSpec().getAtomicSpecLoc());
10032 D.setInvalidType();
10036 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);
10038 // C++0x [class.dtor]p2:
10039 // A destructor shall not be declared with a ref-qualifier.
10040 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
10041 if (FTI.hasRefQualifier()) {
10042 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
10043 << FTI.RefQualifierIsLValueRef
10044 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
10045 D.setInvalidType();
10048 // Make sure we don't have any parameters.
10049 if (FTIHasNonVoidParameters(FTI)) {
10050 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
10052 // Delete the parameters.
10054 D.setInvalidType();
10057 // Make sure the destructor isn't variadic.
10058 if (FTI.isVariadic) {
10059 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
10060 D.setInvalidType();
10063 // Rebuild the function type "R" without any type qualifiers or
10064 // parameters (in case any of the errors above fired) and with
10065 // "void" as the return type, since destructors don't have return
10067 if (!D.isInvalidType())
10070 const FunctionProtoType *Proto = R->castAs<FunctionProtoType>();
10071 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
10072 EPI.Variadic = false;
10073 EPI.TypeQuals = Qualifiers();
10074 EPI.RefQualifier = RQ_None;
10075 return Context.getFunctionType(Context.VoidTy, None, EPI);
10078 static void extendLeft(SourceRange &R, SourceRange Before) {
10079 if (Before.isInvalid())
10081 R.setBegin(Before.getBegin());
10082 if (R.getEnd().isInvalid())
10083 R.setEnd(Before.getEnd());
10086 static void extendRight(SourceRange &R, SourceRange After) {
10087 if (After.isInvalid())
10089 if (R.getBegin().isInvalid())
10090 R.setBegin(After.getBegin());
10091 R.setEnd(After.getEnd());
10094 /// CheckConversionDeclarator - Called by ActOnDeclarator to check the
10095 /// well-formednes of the conversion function declarator @p D with
10096 /// type @p R. If there are any errors in the declarator, this routine
10097 /// will emit diagnostics and return true. Otherwise, it will return
10098 /// false. Either way, the type @p R will be updated to reflect a
10099 /// well-formed type for the conversion operator.
10100 void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
10101 StorageClass& SC) {
10102 // C++ [class.conv.fct]p1:
10103 // Neither parameter types nor return type can be specified. The
10104 // type of a conversion function (8.3.5) is "function taking no
10105 // parameter returning conversion-type-id."
10106 if (SC == SC_Static) {
10107 if (!D.isInvalidType())
10108 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
10109 << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
10110 << D.getName().getSourceRange();
10111 D.setInvalidType();
10115 TypeSourceInfo *ConvTSI = nullptr;
10116 QualType ConvType =
10117 GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);
10119 const DeclSpec &DS = D.getDeclSpec();
10120 if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
10121 // Conversion functions don't have return types, but the parser will
10122 // happily parse something like:
10125 // float operator bool();
10128 // The return type will be changed later anyway.
10129 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
10130 << SourceRange(DS.getTypeSpecTypeLoc())
10131 << SourceRange(D.getIdentifierLoc());
10132 D.setInvalidType();
10133 } else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
10134 // It's also plausible that the user writes type qualifiers in the wrong
10136 // struct S { const operator int(); };
10137 // FIXME: we could provide a fixit to move the qualifiers onto the
10138 // conversion type.
10139 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
10140 << SourceRange(D.getIdentifierLoc()) << 0;
10141 D.setInvalidType();
10144 const auto *Proto = R->castAs<FunctionProtoType>();
10146 // Make sure we don't have any parameters.
10147 if (Proto->getNumParams() > 0) {
10148 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
10150 // Delete the parameters.
10151 D.getFunctionTypeInfo().freeParams();
10152 D.setInvalidType();
10153 } else if (Proto->isVariadic()) {
10154 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
10155 D.setInvalidType();
10158 // Diagnose "&operator bool()" and other such nonsense. This
10159 // is actually a gcc extension which we don't support.
10160 if (Proto->getReturnType() != ConvType) {
10161 bool NeedsTypedef = false;
10162 SourceRange Before, After;
10164 // Walk the chunks and extract information on them for our diagnostic.
10165 bool PastFunctionChunk = false;
10166 for (auto &Chunk : D.type_objects()) {
10167 switch (Chunk.Kind) {
10168 case DeclaratorChunk::Function:
10169 if (!PastFunctionChunk) {
10170 if (Chunk.Fun.HasTrailingReturnType) {
10171 TypeSourceInfo *TRT = nullptr;
10172 GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
10173 if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
10175 PastFunctionChunk = true;
10179 case DeclaratorChunk::Array:
10180 NeedsTypedef = true;
10181 extendRight(After, Chunk.getSourceRange());
10184 case DeclaratorChunk::Pointer:
10185 case DeclaratorChunk::BlockPointer:
10186 case DeclaratorChunk::Reference:
10187 case DeclaratorChunk::MemberPointer:
10188 case DeclaratorChunk::Pipe:
10189 extendLeft(Before, Chunk.getSourceRange());
10192 case DeclaratorChunk::Paren:
10193 extendLeft(Before, Chunk.Loc);
10194 extendRight(After, Chunk.EndLoc);
10199 SourceLocation Loc = Before.isValid() ? Before.getBegin() :
10200 After.isValid() ? After.getBegin() :
10201 D.getIdentifierLoc();
10202 auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
10203 DB << Before << After;
10205 if (!NeedsTypedef) {
10206 DB << /*don't need a typedef*/0;
10208 // If we can provide a correct fix-it hint, do so.
10209 if (After.isInvalid() && ConvTSI) {
10210 SourceLocation InsertLoc =
10211 getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
10212 DB << FixItHint::CreateInsertion(InsertLoc, " ")
10213 << FixItHint::CreateInsertionFromRange(
10214 InsertLoc, CharSourceRange::getTokenRange(Before))
10215 << FixItHint::CreateRemoval(Before);
10217 } else if (!Proto->getReturnType()->isDependentType()) {
10218 DB << /*typedef*/1 << Proto->getReturnType();
10219 } else if (getLangOpts().CPlusPlus11) {
10220 DB << /*alias template*/2 << Proto->getReturnType();
10222 DB << /*might not be fixable*/3;
10225 // Recover by incorporating the other type chunks into the result type.
10226 // Note, this does *not* change the name of the function. This is compatible
10227 // with the GCC extension:
10228 // struct S { &operator int(); } s;
10229 // int &r = s.operator int(); // ok in GCC
10230 // S::operator int&() {} // error in GCC, function name is 'operator int'.
10231 ConvType = Proto->getReturnType();
10234 // C++ [class.conv.fct]p4:
10235 // The conversion-type-id shall not represent a function type nor
10237 if (ConvType->isArrayType()) {
10238 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
10239 ConvType = Context.getPointerType(ConvType);
10240 D.setInvalidType();
10241 } else if (ConvType->isFunctionType()) {
10242 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
10243 ConvType = Context.getPointerType(ConvType);
10244 D.setInvalidType();
10247 // Rebuild the function type "R" without any parameters (in case any
10248 // of the errors above fired) and with the conversion type as the
10250 if (D.isInvalidType())
10251 R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());
10253 // C++0x explicit conversion operators.
10254 if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus2a)
10255 Diag(DS.getExplicitSpecLoc(),
10256 getLangOpts().CPlusPlus11
10257 ? diag::warn_cxx98_compat_explicit_conversion_functions
10258 : diag::ext_explicit_conversion_functions)
10259 << SourceRange(DS.getExplicitSpecRange());
10262 /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
10263 /// the declaration of the given C++ conversion function. This routine
10264 /// is responsible for recording the conversion function in the C++
10265 /// class, if possible.
10266 Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
10267 assert(Conversion && "Expected to receive a conversion function declaration");
10269 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
10271 // Make sure we aren't redeclaring the conversion function.
10272 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
10274 // C++ [class.conv.fct]p1:
10275 // [...] A conversion function is never used to convert a
10276 // (possibly cv-qualified) object to the (possibly cv-qualified)
10277 // same object type (or a reference to it), to a (possibly
10278 // cv-qualified) base class of that type (or a reference to it),
10279 // or to (possibly cv-qualified) void.
10280 // FIXME: Suppress this warning if the conversion function ends up being a
10281 // virtual function that overrides a virtual function in a base class.
10283 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
10284 if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
10285 ConvType = ConvTypeRef->getPointeeType();
10286 if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
10287 Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
10288 /* Suppress diagnostics for instantiations. */;
10289 else if (ConvType->isRecordType()) {
10290 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
10291 if (ConvType == ClassType)
10292 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
10294 else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
10295 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
10296 << ClassType << ConvType;
10297 } else if (ConvType->isVoidType()) {
10298 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
10299 << ClassType << ConvType;
10302 if (FunctionTemplateDecl *ConversionTemplate
10303 = Conversion->getDescribedFunctionTemplate())
10304 return ConversionTemplate;
10310 /// Utility class to accumulate and print a diagnostic listing the invalid
10311 /// specifier(s) on a declaration.
10312 struct BadSpecifierDiagnoser {
10313 BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
10314 : S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
10315 ~BadSpecifierDiagnoser() {
10316 Diagnostic << Specifiers;
10319 template<typename T> void check(SourceLocation SpecLoc, T Spec) {
10320 return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
10322 void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
10323 return check(SpecLoc,
10324 DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
10326 void check(SourceLocation SpecLoc, const char *Spec) {
10327 if (SpecLoc.isInvalid()) return;
10328 Diagnostic << SourceRange(SpecLoc, SpecLoc);
10329 if (!Specifiers.empty()) Specifiers += " ";
10330 Specifiers += Spec;
10334 Sema::SemaDiagnosticBuilder Diagnostic;
10335 std::string Specifiers;
10339 /// Check the validity of a declarator that we parsed for a deduction-guide.
10340 /// These aren't actually declarators in the grammar, so we need to check that
10341 /// the user didn't specify any pieces that are not part of the deduction-guide
10343 void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
10344 StorageClass &SC) {
10345 TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
10346 TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
10347 assert(GuidedTemplateDecl && "missing template decl for deduction guide");
10349 // C++ [temp.deduct.guide]p3:
10350 // A deduction-gide shall be declared in the same scope as the
10351 // corresponding class template.
10352 if (!CurContext->getRedeclContext()->Equals(
10353 GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
10354 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
10355 << GuidedTemplateDecl;
10356 Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
10359 auto &DS = D.getMutableDeclSpec();
10360 // We leave 'friend' and 'virtual' to be rejected in the normal way.
10361 if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
10362 DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
10363 DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
10364 BadSpecifierDiagnoser Diagnoser(
10365 *this, D.getIdentifierLoc(),
10366 diag::err_deduction_guide_invalid_specifier);
10368 Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
10369 DS.ClearStorageClassSpecs();
10372 // 'explicit' is permitted.
10373 Diagnoser.check(DS.getInlineSpecLoc(), "inline");
10374 Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
10375 Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
10376 DS.ClearConstexprSpec();
10378 Diagnoser.check(DS.getConstSpecLoc(), "const");
10379 Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
10380 Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
10381 Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
10382 Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
10383 DS.ClearTypeQualifiers();
10385 Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
10386 Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
10387 Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
10388 Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
10389 DS.ClearTypeSpecType();
10392 if (D.isInvalidType())
10395 // Check the declarator is simple enough.
10396 bool FoundFunction = false;
10397 for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
10398 if (Chunk.Kind == DeclaratorChunk::Paren)
10400 if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
10401 Diag(D.getDeclSpec().getBeginLoc(),
10402 diag::err_deduction_guide_with_complex_decl)
10403 << D.getSourceRange();
10406 if (!Chunk.Fun.hasTrailingReturnType()) {
10407 Diag(D.getName().getBeginLoc(),
10408 diag::err_deduction_guide_no_trailing_return_type);
10412 // Check that the return type is written as a specialization of
10413 // the template specified as the deduction-guide's name.
10414 ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
10415 TypeSourceInfo *TSI = nullptr;
10416 QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
10417 assert(TSI && "deduction guide has valid type but invalid return type?");
10418 bool AcceptableReturnType = false;
10419 bool MightInstantiateToSpecialization = false;
10421 TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
10422 TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
10423 bool TemplateMatches =
10424 Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
10425 if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
10426 AcceptableReturnType = true;
10428 // This could still instantiate to the right type, unless we know it
10429 // names the wrong class template.
10430 auto *TD = SpecifiedName.getAsTemplateDecl();
10431 MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
10434 } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
10435 MightInstantiateToSpecialization = true;
10438 if (!AcceptableReturnType) {
10439 Diag(TSI->getTypeLoc().getBeginLoc(),
10440 diag::err_deduction_guide_bad_trailing_return_type)
10441 << GuidedTemplate << TSI->getType()
10442 << MightInstantiateToSpecialization
10443 << TSI->getTypeLoc().getSourceRange();
10446 // Keep going to check that we don't have any inner declarator pieces (we
10447 // could still have a function returning a pointer to a function).
10448 FoundFunction = true;
10451 if (D.isFunctionDefinition())
10452 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
10455 //===----------------------------------------------------------------------===//
10456 // Namespace Handling
10457 //===----------------------------------------------------------------------===//
10459 /// Diagnose a mismatch in 'inline' qualifiers when a namespace is
10461 static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
10462 SourceLocation Loc,
10463 IdentifierInfo *II, bool *IsInline,
10464 NamespaceDecl *PrevNS) {
10465 assert(*IsInline != PrevNS->isInline());
10467 // HACK: Work around a bug in libstdc++4.6's <atomic>, where
10468 // std::__atomic[0,1,2] are defined as non-inline namespaces, then reopened as
10469 // inline namespaces, with the intention of bringing names into namespace std.
10471 // We support this just well enough to get that case working; this is not
10472 // sufficient to support reopening namespaces as inline in general.
10473 if (*IsInline && II && II->getName().startswith("__atomic") &&
10474 S.getSourceManager().isInSystemHeader(Loc)) {
10475 // Mark all prior declarations of the namespace as inline.
10476 for (NamespaceDecl *NS = PrevNS->getMostRecentDecl(); NS;
10477 NS = NS->getPreviousDecl())
10478 NS->setInline(*IsInline);
10479 // Patch up the lookup table for the containing namespace. This isn't really
10480 // correct, but it's good enough for this particular case.
10481 for (auto *I : PrevNS->decls())
10482 if (auto *ND = dyn_cast<NamedDecl>(I))
10483 PrevNS->getParent()->makeDeclVisibleInContext(ND);
10487 if (PrevNS->isInline())
10488 // The user probably just forgot the 'inline', so suggest that it
10490 S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
10491 << FixItHint::CreateInsertion(KeywordLoc, "inline ");
10493 S.Diag(Loc, diag::err_inline_namespace_mismatch);
10495 S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
10496 *IsInline = PrevNS->isInline();
10499 /// ActOnStartNamespaceDef - This is called at the start of a namespace
10501 Decl *Sema::ActOnStartNamespaceDef(
10502 Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
10503 SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
10504 const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
10505 SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
10506 // For anonymous namespace, take the location of the left brace.
10507 SourceLocation Loc = II ? IdentLoc : LBrace;
10508 bool IsInline = InlineLoc.isValid();
10509 bool IsInvalid = false;
10510 bool IsStd = false;
10511 bool AddToKnown = false;
10512 Scope *DeclRegionScope = NamespcScope->getParent();
10514 NamespaceDecl *PrevNS = nullptr;
10516 // C++ [namespace.def]p2:
10517 // The identifier in an original-namespace-definition shall not
10518 // have been previously defined in the declarative region in
10519 // which the original-namespace-definition appears. The
10520 // identifier in an original-namespace-definition is the name of
10521 // the namespace. Subsequently in that declarative region, it is
10522 // treated as an original-namespace-name.
10524 // Since namespace names are unique in their scope, and we don't
10525 // look through using directives, just look for any ordinary names
10526 // as if by qualified name lookup.
10527 LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
10528 ForExternalRedeclaration);
10529 LookupQualifiedName(R, CurContext->getRedeclContext());
10530 NamedDecl *PrevDecl =
10531 R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
10532 PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
10535 // This is an extended namespace definition.
10536 if (IsInline != PrevNS->isInline())
10537 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
10538 &IsInline, PrevNS);
10539 } else if (PrevDecl) {
10540 // This is an invalid name redefinition.
10541 Diag(Loc, diag::err_redefinition_different_kind)
10543 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
10545 // Continue on to push Namespc as current DeclContext and return it.
10546 } else if (II->isStr("std") &&
10547 CurContext->getRedeclContext()->isTranslationUnit()) {
10548 // This is the first "real" definition of the namespace "std", so update
10549 // our cache of the "std" namespace to point at this definition.
10550 PrevNS = getStdNamespace();
10552 AddToKnown = !IsInline;
10554 // We've seen this namespace for the first time.
10555 AddToKnown = !IsInline;
10558 // Anonymous namespaces.
10560 // Determine whether the parent already has an anonymous namespace.
10561 DeclContext *Parent = CurContext->getRedeclContext();
10562 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
10563 PrevNS = TU->getAnonymousNamespace();
10565 NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
10566 PrevNS = ND->getAnonymousNamespace();
10569 if (PrevNS && IsInline != PrevNS->isInline())
10570 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
10571 &IsInline, PrevNS);
10574 NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
10575 StartLoc, Loc, II, PrevNS);
10577 Namespc->setInvalidDecl();
10579 ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
10580 AddPragmaAttributes(DeclRegionScope, Namespc);
10582 // FIXME: Should we be merging attributes?
10583 if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
10584 PushNamespaceVisibilityAttr(Attr, Loc);
10587 StdNamespace = Namespc;
10589 KnownNamespaces[Namespc] = false;
10592 PushOnScopeChains(Namespc, DeclRegionScope);
10594 // Link the anonymous namespace into its parent.
10595 DeclContext *Parent = CurContext->getRedeclContext();
10596 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
10597 TU->setAnonymousNamespace(Namespc);
10599 cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
10602 CurContext->addDecl(Namespc);
10604 // C++ [namespace.unnamed]p1. An unnamed-namespace-definition
10605 // behaves as if it were replaced by
10606 // namespace unique { /* empty body */ }
10607 // using namespace unique;
10608 // namespace unique { namespace-body }
10609 // where all occurrences of 'unique' in a translation unit are
10610 // replaced by the same identifier and this identifier differs
10611 // from all other identifiers in the entire program.
10613 // We just create the namespace with an empty name and then add an
10614 // implicit using declaration, just like the standard suggests.
10616 // CodeGen enforces the "universally unique" aspect by giving all
10617 // declarations semantically contained within an anonymous
10618 // namespace internal linkage.
10621 UD = UsingDirectiveDecl::Create(Context, Parent,
10622 /* 'using' */ LBrace,
10623 /* 'namespace' */ SourceLocation(),
10624 /* qualifier */ NestedNameSpecifierLoc(),
10625 /* identifier */ SourceLocation(),
10627 /* Ancestor */ Parent);
10629 Parent->addDecl(UD);
10633 ActOnDocumentableDecl(Namespc);
10635 // Although we could have an invalid decl (i.e. the namespace name is a
10636 // redefinition), push it as current DeclContext and try to continue parsing.
10637 // FIXME: We should be able to push Namespc here, so that the each DeclContext
10638 // for the namespace has the declarations that showed up in that particular
10639 // namespace definition.
10640 PushDeclContext(NamespcScope, Namespc);
10644 /// getNamespaceDecl - Returns the namespace a decl represents. If the decl
10645 /// is a namespace alias, returns the namespace it points to.
10646 static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
10647 if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
10648 return AD->getNamespace();
10649 return dyn_cast_or_null<NamespaceDecl>(D);
10652 /// ActOnFinishNamespaceDef - This callback is called after a namespace is
10653 /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
10654 void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
10655 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
10656 assert(Namespc && "Invalid parameter, expected NamespaceDecl");
10657 Namespc->setRBraceLoc(RBrace);
10659 if (Namespc->hasAttr<VisibilityAttr>())
10660 PopPragmaVisibility(true, RBrace);
10661 // If this namespace contains an export-declaration, export it now.
10662 if (DeferredExportedNamespaces.erase(Namespc))
10663 Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
10666 CXXRecordDecl *Sema::getStdBadAlloc() const {
10667 return cast_or_null<CXXRecordDecl>(
10668 StdBadAlloc.get(Context.getExternalSource()));
10671 EnumDecl *Sema::getStdAlignValT() const {
10672 return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
10675 NamespaceDecl *Sema::getStdNamespace() const {
10676 return cast_or_null<NamespaceDecl>(
10677 StdNamespace.get(Context.getExternalSource()));
10680 NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
10681 if (!StdExperimentalNamespaceCache) {
10682 if (auto Std = getStdNamespace()) {
10683 LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
10684 SourceLocation(), LookupNamespaceName);
10685 if (!LookupQualifiedName(Result, Std) ||
10686 !(StdExperimentalNamespaceCache =
10687 Result.getAsSingle<NamespaceDecl>()))
10688 Result.suppressDiagnostics();
10691 return StdExperimentalNamespaceCache;
10696 enum UnsupportedSTLSelect {
10703 struct InvalidSTLDiagnoser {
10705 SourceLocation Loc;
10706 QualType TyForDiags;
10708 QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
10709 const VarDecl *VD = nullptr) {
10711 auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
10712 << TyForDiags << ((int)Sel);
10713 if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
10714 assert(!Name.empty());
10718 if (Sel == USS_InvalidMember) {
10719 S.Diag(VD->getLocation(), diag::note_var_declared_here)
10720 << VD << VD->getSourceRange();
10727 QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
10728 SourceLocation Loc,
10729 ComparisonCategoryUsage Usage) {
10730 assert(getLangOpts().CPlusPlus &&
10731 "Looking for comparison category type outside of C++.");
10733 // Use an elaborated type for diagnostics which has a name containing the
10734 // prepended 'std' namespace but not any inline namespace names.
10735 auto TyForDiags = [&](ComparisonCategoryInfo *Info) {
10737 NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
10738 return Context.getElaboratedType(ETK_None, NNS, Info->getType());
10741 // Check if we've already successfully checked the comparison category type
10742 // before. If so, skip checking it again.
10743 ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
10744 if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)]) {
10745 // The only thing we need to check is that the type has a reachable
10746 // definition in the current context.
10747 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
10750 return Info->getType();
10753 // If lookup failed
10755 std::string NameForDiags = "std::";
10756 NameForDiags += ComparisonCategories::getCategoryString(Kind);
10757 Diag(Loc, diag::err_implied_comparison_category_type_not_found)
10758 << NameForDiags << (int)Usage;
10762 assert(Info->Kind == Kind);
10763 assert(Info->Record);
10765 // Update the Record decl in case we encountered a forward declaration on our
10766 // first pass. FIXME: This is a bit of a hack.
10767 if (Info->Record->hasDefinition())
10768 Info->Record = Info->Record->getDefinition();
10770 if (RequireCompleteType(Loc, TyForDiags(Info), diag::err_incomplete_type))
10773 InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags(Info)};
10775 if (!Info->Record->isTriviallyCopyable())
10776 return UnsupportedSTLError(USS_NonTrivial);
10778 for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
10779 CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
10780 // Tolerate empty base classes.
10781 if (Base->isEmpty())
10783 // Reject STL implementations which have at least one non-empty base.
10784 return UnsupportedSTLError();
10787 // Check that the STL has implemented the types using a single integer field.
10788 // This expectation allows better codegen for builtin operators. We require:
10789 // (1) The class has exactly one field.
10790 // (2) The field is an integral or enumeration type.
10791 auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
10792 if (std::distance(FIt, FEnd) != 1 ||
10793 !FIt->getType()->isIntegralOrEnumerationType()) {
10794 return UnsupportedSTLError();
10797 // Build each of the require values and store them in Info.
10798 for (ComparisonCategoryResult CCR :
10799 ComparisonCategories::getPossibleResultsForType(Kind)) {
10800 StringRef MemName = ComparisonCategories::getResultString(CCR);
10801 ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);
10804 return UnsupportedSTLError(USS_MissingMember, MemName);
10806 VarDecl *VD = ValInfo->VD;
10807 assert(VD && "should not be null!");
10809 // Attempt to diagnose reasons why the STL definition of this type
10810 // might be foobar, including it failing to be a constant expression.
10811 // TODO Handle more ways the lookup or result can be invalid.
10812 if (!VD->isStaticDataMember() || !VD->isConstexpr() || !VD->hasInit() ||
10813 !VD->checkInitIsICE())
10814 return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
10816 // Attempt to evaluate the var decl as a constant expression and extract
10817 // the value of its first field as a ICE. If this fails, the STL
10818 // implementation is not supported.
10819 if (!ValInfo->hasValidIntValue())
10820 return UnsupportedSTLError();
10822 MarkVariableReferenced(Loc, VD);
10825 // We've successfully built the required types and expressions. Update
10826 // the cache and return the newly cached value.
10827 FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
10828 return Info->getType();
10831 /// Retrieve the special "std" namespace, which may require us to
10832 /// implicitly define the namespace.
10833 NamespaceDecl *Sema::getOrCreateStdNamespace() {
10834 if (!StdNamespace) {
10835 // The "std" namespace has not yet been defined, so build one implicitly.
10836 StdNamespace = NamespaceDecl::Create(Context,
10837 Context.getTranslationUnitDecl(),
10839 SourceLocation(), SourceLocation(),
10840 &PP.getIdentifierTable().get("std"),
10841 /*PrevDecl=*/nullptr);
10842 getStdNamespace()->setImplicit(true);
10845 return getStdNamespace();
10848 bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
10849 assert(getLangOpts().CPlusPlus &&
10850 "Looking for std::initializer_list outside of C++.");
10852 // We're looking for implicit instantiations of
10853 // template <typename E> class std::initializer_list.
10855 if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
10858 ClassTemplateDecl *Template = nullptr;
10859 const TemplateArgument *Arguments = nullptr;
10861 if (const RecordType *RT = Ty->getAs<RecordType>()) {
10863 ClassTemplateSpecializationDecl *Specialization =
10864 dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
10865 if (!Specialization)
10868 Template = Specialization->getSpecializedTemplate();
10869 Arguments = Specialization->getTemplateArgs().data();
10870 } else if (const TemplateSpecializationType *TST =
10871 Ty->getAs<TemplateSpecializationType>()) {
10872 Template = dyn_cast_or_null<ClassTemplateDecl>(
10873 TST->getTemplateName().getAsTemplateDecl());
10874 Arguments = TST->getArgs();
10879 if (!StdInitializerList) {
10880 // Haven't recognized std::initializer_list yet, maybe this is it.
10881 CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
10882 if (TemplateClass->getIdentifier() !=
10883 &PP.getIdentifierTable().get("initializer_list") ||
10884 !getStdNamespace()->InEnclosingNamespaceSetOf(
10885 TemplateClass->getDeclContext()))
10887 // This is a template called std::initializer_list, but is it the right
10889 TemplateParameterList *Params = Template->getTemplateParameters();
10890 if (Params->getMinRequiredArguments() != 1)
10892 if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
10895 // It's the right template.
10896 StdInitializerList = Template;
10899 if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
10902 // This is an instance of std::initializer_list. Find the argument type.
10904 *Element = Arguments[0].getAsType();
10908 static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
10909 NamespaceDecl *Std = S.getStdNamespace();
10911 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
10915 LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
10916 Loc, Sema::LookupOrdinaryName);
10917 if (!S.LookupQualifiedName(Result, Std)) {
10918 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
10921 ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
10923 Result.suppressDiagnostics();
10924 // We found something weird. Complain about the first thing we found.
10925 NamedDecl *Found = *Result.begin();
10926 S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
10930 // We found some template called std::initializer_list. Now verify that it's
10932 TemplateParameterList *Params = Template->getTemplateParameters();
10933 if (Params->getMinRequiredArguments() != 1 ||
10934 !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
10935 S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
10942 QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
10943 if (!StdInitializerList) {
10944 StdInitializerList = LookupStdInitializerList(*this, Loc);
10945 if (!StdInitializerList)
10949 TemplateArgumentListInfo Args(Loc, Loc);
10950 Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
10951 Context.getTrivialTypeSourceInfo(Element,
10953 return Context.getCanonicalType(
10954 CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
10957 bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
10958 // C++ [dcl.init.list]p2:
10959 // A constructor is an initializer-list constructor if its first parameter
10960 // is of type std::initializer_list<E> or reference to possibly cv-qualified
10961 // std::initializer_list<E> for some type E, and either there are no other
10962 // parameters or else all other parameters have default arguments.
10963 if (Ctor->getNumParams() < 1 ||
10964 (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg()))
10967 QualType ArgType = Ctor->getParamDecl(0)->getType();
10968 if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
10969 ArgType = RT->getPointeeType().getUnqualifiedType();
10971 return isStdInitializerList(ArgType, nullptr);
10974 /// Determine whether a using statement is in a context where it will be
10975 /// apply in all contexts.
10976 static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
10977 switch (CurContext->getDeclKind()) {
10978 case Decl::TranslationUnit:
10980 case Decl::LinkageSpec:
10981 return IsUsingDirectiveInToplevelContext(CurContext->getParent());
10989 // Callback to only accept typo corrections that are namespaces.
10990 class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
10992 bool ValidateCandidate(const TypoCorrection &candidate) override {
10993 if (NamedDecl *ND = candidate.getCorrectionDecl())
10994 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
10998 std::unique_ptr<CorrectionCandidateCallback> clone() override {
10999 return std::make_unique<NamespaceValidatorCCC>(*this);
11005 static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
11007 SourceLocation IdentLoc,
11008 IdentifierInfo *Ident) {
11010 NamespaceValidatorCCC CCC{};
11011 if (TypoCorrection Corrected =
11012 S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
11013 Sema::CTK_ErrorRecovery)) {
11014 if (DeclContext *DC = S.computeDeclContext(SS, false)) {
11015 std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
11016 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
11017 Ident->getName().equals(CorrectedStr);
11018 S.diagnoseTypo(Corrected,
11019 S.PDiag(diag::err_using_directive_member_suggest)
11020 << Ident << DC << DroppedSpecifier << SS.getRange(),
11021 S.PDiag(diag::note_namespace_defined_here));
11023 S.diagnoseTypo(Corrected,
11024 S.PDiag(diag::err_using_directive_suggest) << Ident,
11025 S.PDiag(diag::note_namespace_defined_here));
11027 R.addDecl(Corrected.getFoundDecl());
11033 Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
11034 SourceLocation NamespcLoc, CXXScopeSpec &SS,
11035 SourceLocation IdentLoc,
11036 IdentifierInfo *NamespcName,
11037 const ParsedAttributesView &AttrList) {
11038 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
11039 assert(NamespcName && "Invalid NamespcName.");
11040 assert(IdentLoc.isValid() && "Invalid NamespceName location.");
11042 // This can only happen along a recovery path.
11043 while (S->isTemplateParamScope())
11044 S = S->getParent();
11045 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
11047 UsingDirectiveDecl *UDir = nullptr;
11048 NestedNameSpecifier *Qualifier = nullptr;
11050 Qualifier = SS.getScopeRep();
11052 // Lookup namespace name.
11053 LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
11054 LookupParsedName(R, S, &SS);
11055 if (R.isAmbiguous())
11060 // Allow "using namespace std;" or "using namespace ::std;" even if
11061 // "std" hasn't been defined yet, for GCC compatibility.
11062 if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
11063 NamespcName->isStr("std")) {
11064 Diag(IdentLoc, diag::ext_using_undefined_std);
11065 R.addDecl(getOrCreateStdNamespace());
11068 // Otherwise, attempt typo correction.
11069 else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
11073 NamedDecl *Named = R.getRepresentativeDecl();
11074 NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
11075 assert(NS && "expected namespace decl");
11077 // The use of a nested name specifier may trigger deprecation warnings.
11078 DiagnoseUseOfDecl(Named, IdentLoc);
11080 // C++ [namespace.udir]p1:
11081 // A using-directive specifies that the names in the nominated
11082 // namespace can be used in the scope in which the
11083 // using-directive appears after the using-directive. During
11084 // unqualified name lookup (3.4.1), the names appear as if they
11085 // were declared in the nearest enclosing namespace which
11086 // contains both the using-directive and the nominated
11087 // namespace. [Note: in this context, "contains" means "contains
11088 // directly or indirectly". ]
11090 // Find enclosing context containing both using-directive and
11091 // nominated namespace.
11092 DeclContext *CommonAncestor = NS;
11093 while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
11094 CommonAncestor = CommonAncestor->getParent();
11096 UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
11097 SS.getWithLocInContext(Context),
11098 IdentLoc, Named, CommonAncestor);
11100 if (IsUsingDirectiveInToplevelContext(CurContext) &&
11101 !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
11102 Diag(IdentLoc, diag::warn_using_directive_in_header);
11105 PushUsingDirective(S, UDir);
11107 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
11111 ProcessDeclAttributeList(S, UDir, AttrList);
11116 void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
11117 // If the scope has an associated entity and the using directive is at
11118 // namespace or translation unit scope, add the UsingDirectiveDecl into
11119 // its lookup structure so qualified name lookup can find it.
11120 DeclContext *Ctx = S->getEntity();
11121 if (Ctx && !Ctx->isFunctionOrMethod())
11122 Ctx->addDecl(UDir);
11124 // Otherwise, it is at block scope. The using-directives will affect lookup
11125 // only to the end of the scope.
11126 S->PushUsingDirective(UDir);
11129 Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
11130 SourceLocation UsingLoc,
11131 SourceLocation TypenameLoc, CXXScopeSpec &SS,
11132 UnqualifiedId &Name,
11133 SourceLocation EllipsisLoc,
11134 const ParsedAttributesView &AttrList) {
11135 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
11137 if (SS.isEmpty()) {
11138 Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
11142 switch (Name.getKind()) {
11143 case UnqualifiedIdKind::IK_ImplicitSelfParam:
11144 case UnqualifiedIdKind::IK_Identifier:
11145 case UnqualifiedIdKind::IK_OperatorFunctionId:
11146 case UnqualifiedIdKind::IK_LiteralOperatorId:
11147 case UnqualifiedIdKind::IK_ConversionFunctionId:
11150 case UnqualifiedIdKind::IK_ConstructorName:
11151 case UnqualifiedIdKind::IK_ConstructorTemplateId:
11152 // C++11 inheriting constructors.
11153 Diag(Name.getBeginLoc(),
11154 getLangOpts().CPlusPlus11
11155 ? diag::warn_cxx98_compat_using_decl_constructor
11156 : diag::err_using_decl_constructor)
11159 if (getLangOpts().CPlusPlus11) break;
11163 case UnqualifiedIdKind::IK_DestructorName:
11164 Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
11167 case UnqualifiedIdKind::IK_TemplateId:
11168 Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
11169 << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
11172 case UnqualifiedIdKind::IK_DeductionGuideName:
11173 llvm_unreachable("cannot parse qualified deduction guide name");
11176 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
11177 DeclarationName TargetName = TargetNameInfo.getName();
11181 // Warn about access declarations.
11182 if (UsingLoc.isInvalid()) {
11183 Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
11184 ? diag::err_access_decl
11185 : diag::warn_access_decl_deprecated)
11186 << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
11189 if (EllipsisLoc.isInvalid()) {
11190 if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
11191 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
11194 if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
11195 !TargetNameInfo.containsUnexpandedParameterPack()) {
11196 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
11197 << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
11198 EllipsisLoc = SourceLocation();
11203 BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
11204 SS, TargetNameInfo, EllipsisLoc, AttrList,
11205 /*IsInstantiation*/false);
11207 PushOnScopeChains(UD, S, /*AddToContext*/ false);
11212 /// Determine whether a using declaration considers the given
11213 /// declarations as "equivalent", e.g., if they are redeclarations of
11214 /// the same entity or are both typedefs of the same type.
11216 IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
11217 if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
11220 if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
11221 if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
11222 return Context.hasSameType(TD1->getUnderlyingType(),
11223 TD2->getUnderlyingType());
11229 /// Determines whether to create a using shadow decl for a particular
11230 /// decl, given the set of decls existing prior to this using lookup.
11231 bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
11232 const LookupResult &Previous,
11233 UsingShadowDecl *&PrevShadow) {
11234 // Diagnose finding a decl which is not from a base class of the
11235 // current class. We do this now because there are cases where this
11236 // function will silently decide not to build a shadow decl, which
11237 // will pre-empt further diagnostics.
11239 // We don't need to do this in C++11 because we do the check once on
11242 // FIXME: diagnose the following if we care enough:
11243 // struct A { int foo; };
11244 // struct B : A { using A::foo; };
11245 // template <class T> struct C : A {};
11246 // template <class T> struct D : C<T> { using B::foo; } // <---
11247 // This is invalid (during instantiation) in C++03 because B::foo
11248 // resolves to the using decl in B, which is not a base class of D<T>.
11249 // We can't diagnose it immediately because C<T> is an unknown
11250 // specialization. The UsingShadowDecl in D<T> then points directly
11251 // to A::foo, which will look well-formed when we instantiate.
11252 // The right solution is to not collapse the shadow-decl chain.
11253 if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) {
11254 DeclContext *OrigDC = Orig->getDeclContext();
11256 // Handle enums and anonymous structs.
11257 if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
11258 CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
11259 while (OrigRec->isAnonymousStructOrUnion())
11260 OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
11262 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
11263 if (OrigDC == CurContext) {
11264 Diag(Using->getLocation(),
11265 diag::err_using_decl_nested_name_specifier_is_current_class)
11266 << Using->getQualifierLoc().getSourceRange();
11267 Diag(Orig->getLocation(), diag::note_using_decl_target);
11268 Using->setInvalidDecl();
11272 Diag(Using->getQualifierLoc().getBeginLoc(),
11273 diag::err_using_decl_nested_name_specifier_is_not_base_class)
11274 << Using->getQualifier()
11275 << cast<CXXRecordDecl>(CurContext)
11276 << Using->getQualifierLoc().getSourceRange();
11277 Diag(Orig->getLocation(), diag::note_using_decl_target);
11278 Using->setInvalidDecl();
11283 if (Previous.empty()) return false;
11285 NamedDecl *Target = Orig;
11286 if (isa<UsingShadowDecl>(Target))
11287 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11289 // If the target happens to be one of the previous declarations, we
11290 // don't have a conflict.
11292 // FIXME: but we might be increasing its access, in which case we
11293 // should redeclare it.
11294 NamedDecl *NonTag = nullptr, *Tag = nullptr;
11295 bool FoundEquivalentDecl = false;
11296 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
11298 NamedDecl *D = (*I)->getUnderlyingDecl();
11299 // We can have UsingDecls in our Previous results because we use the same
11300 // LookupResult for checking whether the UsingDecl itself is a valid
11302 if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D))
11305 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
11306 // C++ [class.mem]p19:
11307 // If T is the name of a class, then [every named member other than
11308 // a non-static data member] shall have a name different from T
11309 if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
11310 !isa<IndirectFieldDecl>(Target) &&
11311 !isa<UnresolvedUsingValueDecl>(Target) &&
11312 DiagnoseClassNameShadow(
11314 DeclarationNameInfo(Using->getDeclName(), Using->getLocation())))
11318 if (IsEquivalentForUsingDecl(Context, D, Target)) {
11319 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
11320 PrevShadow = Shadow;
11321 FoundEquivalentDecl = true;
11322 } else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
11323 // We don't conflict with an existing using shadow decl of an equivalent
11324 // declaration, but we're not a redeclaration of it.
11325 FoundEquivalentDecl = true;
11329 (isa<TagDecl>(D) ? Tag : NonTag) = D;
11332 if (FoundEquivalentDecl)
11335 if (FunctionDecl *FD = Target->getAsFunction()) {
11336 NamedDecl *OldDecl = nullptr;
11337 switch (CheckOverload(nullptr, FD, Previous, OldDecl,
11338 /*IsForUsingDecl*/ true)) {
11342 case Ovl_NonFunction:
11343 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11346 // We found a decl with the exact signature.
11348 // If we're in a record, we want to hide the target, so we
11349 // return true (without a diagnostic) to tell the caller not to
11350 // build a shadow decl.
11351 if (CurContext->isRecord())
11354 // If we're not in a record, this is an error.
11355 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11359 Diag(Target->getLocation(), diag::note_using_decl_target);
11360 Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
11361 Using->setInvalidDecl();
11365 // Target is not a function.
11367 if (isa<TagDecl>(Target)) {
11368 // No conflict between a tag and a non-tag.
11369 if (!Tag) return false;
11371 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11372 Diag(Target->getLocation(), diag::note_using_decl_target);
11373 Diag(Tag->getLocation(), diag::note_using_decl_conflict);
11374 Using->setInvalidDecl();
11378 // No conflict between a tag and a non-tag.
11379 if (!NonTag) return false;
11381 Diag(Using->getLocation(), diag::err_using_decl_conflict);
11382 Diag(Target->getLocation(), diag::note_using_decl_target);
11383 Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
11384 Using->setInvalidDecl();
11388 /// Determine whether a direct base class is a virtual base class.
11389 static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
11390 if (!Derived->getNumVBases())
11392 for (auto &B : Derived->bases())
11393 if (B.getType()->getAsCXXRecordDecl() == Base)
11394 return B.isVirtual();
11395 llvm_unreachable("not a direct base class");
11398 /// Builds a shadow declaration corresponding to a 'using' declaration.
11399 UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
11402 UsingShadowDecl *PrevDecl) {
11403 // If we resolved to another shadow declaration, just coalesce them.
11404 NamedDecl *Target = Orig;
11405 if (isa<UsingShadowDecl>(Target)) {
11406 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
11407 assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
11410 NamedDecl *NonTemplateTarget = Target;
11411 if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
11412 NonTemplateTarget = TargetTD->getTemplatedDecl();
11414 UsingShadowDecl *Shadow;
11415 if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
11416 bool IsVirtualBase =
11417 isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
11418 UD->getQualifier()->getAsRecordDecl());
11419 Shadow = ConstructorUsingShadowDecl::Create(
11420 Context, CurContext, UD->getLocation(), UD, Orig, IsVirtualBase);
11422 Shadow = UsingShadowDecl::Create(Context, CurContext, UD->getLocation(), UD,
11425 UD->addShadowDecl(Shadow);
11427 Shadow->setAccess(UD->getAccess());
11428 if (Orig->isInvalidDecl() || UD->isInvalidDecl())
11429 Shadow->setInvalidDecl();
11431 Shadow->setPreviousDecl(PrevDecl);
11434 PushOnScopeChains(Shadow, S);
11436 CurContext->addDecl(Shadow);
11442 /// Hides a using shadow declaration. This is required by the current
11443 /// using-decl implementation when a resolvable using declaration in a
11444 /// class is followed by a declaration which would hide or override
11445 /// one or more of the using decl's targets; for example:
11447 /// struct Base { void foo(int); };
11448 /// struct Derived : Base {
11449 /// using Base::foo;
11453 /// The governing language is C++03 [namespace.udecl]p12:
11455 /// When a using-declaration brings names from a base class into a
11456 /// derived class scope, member functions in the derived class
11457 /// override and/or hide member functions with the same name and
11458 /// parameter types in a base class (rather than conflicting).
11460 /// There are two ways to implement this:
11461 /// (1) optimistically create shadow decls when they're not hidden
11462 /// by existing declarations, or
11463 /// (2) don't create any shadow decls (or at least don't make them
11464 /// visible) until we've fully parsed/instantiated the class.
11465 /// The problem with (1) is that we might have to retroactively remove
11466 /// a shadow decl, which requires several O(n) operations because the
11467 /// decl structures are (very reasonably) not designed for removal.
11468 /// (2) avoids this but is very fiddly and phase-dependent.
11469 void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
11470 if (Shadow->getDeclName().getNameKind() ==
11471 DeclarationName::CXXConversionFunctionName)
11472 cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
11474 // Remove it from the DeclContext...
11475 Shadow->getDeclContext()->removeDecl(Shadow);
11477 // ...and the scope, if applicable...
11479 S->RemoveDecl(Shadow);
11480 IdResolver.RemoveDecl(Shadow);
11483 // ...and the using decl.
11484 Shadow->getUsingDecl()->removeShadowDecl(Shadow);
11486 // TODO: complain somehow if Shadow was used. It shouldn't
11487 // be possible for this to happen, because...?
11490 /// Find the base specifier for a base class with the given type.
11491 static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
11492 QualType DesiredBase,
11493 bool &AnyDependentBases) {
11494 // Check whether the named type is a direct base class.
11495 CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
11496 .getUnqualifiedType();
11497 for (auto &Base : Derived->bases()) {
11498 CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
11499 if (CanonicalDesiredBase == BaseType)
11501 if (BaseType->isDependentType())
11502 AnyDependentBases = true;
11508 class UsingValidatorCCC final : public CorrectionCandidateCallback {
11510 UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
11511 NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
11512 : HasTypenameKeyword(HasTypenameKeyword),
11513 IsInstantiation(IsInstantiation), OldNNS(NNS),
11514 RequireMemberOf(RequireMemberOf) {}
11516 bool ValidateCandidate(const TypoCorrection &Candidate) override {
11517 NamedDecl *ND = Candidate.getCorrectionDecl();
11519 // Keywords are not valid here.
11520 if (!ND || isa<NamespaceDecl>(ND))
11523 // Completely unqualified names are invalid for a 'using' declaration.
11524 if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
11527 // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
11530 if (RequireMemberOf) {
11531 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
11532 if (FoundRecord && FoundRecord->isInjectedClassName()) {
11533 // No-one ever wants a using-declaration to name an injected-class-name
11534 // of a base class, unless they're declaring an inheriting constructor.
11535 ASTContext &Ctx = ND->getASTContext();
11536 if (!Ctx.getLangOpts().CPlusPlus11)
11538 QualType FoundType = Ctx.getRecordType(FoundRecord);
11540 // Check that the injected-class-name is named as a member of its own
11541 // type; we don't want to suggest 'using Derived::Base;', since that
11542 // means something else.
11543 NestedNameSpecifier *Specifier =
11544 Candidate.WillReplaceSpecifier()
11545 ? Candidate.getCorrectionSpecifier()
11547 if (!Specifier->getAsType() ||
11548 !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
11551 // Check that this inheriting constructor declaration actually names a
11552 // direct base class of the current class.
11553 bool AnyDependentBases = false;
11554 if (!findDirectBaseWithType(RequireMemberOf,
11555 Ctx.getRecordType(FoundRecord),
11556 AnyDependentBases) &&
11557 !AnyDependentBases)
11560 auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
11561 if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
11564 // FIXME: Check that the base class member is accessible?
11567 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
11568 if (FoundRecord && FoundRecord->isInjectedClassName())
11572 if (isa<TypeDecl>(ND))
11573 return HasTypenameKeyword || !IsInstantiation;
11575 return !HasTypenameKeyword;
11578 std::unique_ptr<CorrectionCandidateCallback> clone() override {
11579 return std::make_unique<UsingValidatorCCC>(*this);
11583 bool HasTypenameKeyword;
11584 bool IsInstantiation;
11585 NestedNameSpecifier *OldNNS;
11586 CXXRecordDecl *RequireMemberOf;
11588 } // end anonymous namespace
11590 /// Builds a using declaration.
11592 /// \param IsInstantiation - Whether this call arises from an
11593 /// instantiation of an unresolved using declaration. We treat
11594 /// the lookup differently for these declarations.
11595 NamedDecl *Sema::BuildUsingDeclaration(
11596 Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
11597 bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
11598 DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
11599 const ParsedAttributesView &AttrList, bool IsInstantiation) {
11600 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
11601 SourceLocation IdentLoc = NameInfo.getLoc();
11602 assert(IdentLoc.isValid() && "Invalid TargetName location.");
11604 // FIXME: We ignore attributes for now.
11606 // For an inheriting constructor declaration, the name of the using
11607 // declaration is the name of a constructor in this class, not in the
11609 DeclarationNameInfo UsingName = NameInfo;
11610 if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
11611 if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
11612 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
11613 Context.getCanonicalType(Context.getRecordType(RD))));
11615 // Do the redeclaration lookup in the current scope.
11616 LookupResult Previous(*this, UsingName, LookupUsingDeclName,
11617 ForVisibleRedeclaration);
11618 Previous.setHideTags(false);
11620 LookupName(Previous, S);
11622 // It is really dumb that we have to do this.
11623 LookupResult::Filter F = Previous.makeFilter();
11624 while (F.hasNext()) {
11625 NamedDecl *D = F.next();
11626 if (!isDeclInScope(D, CurContext, S))
11628 // If we found a local extern declaration that's not ordinarily visible,
11629 // and this declaration is being added to a non-block scope, ignore it.
11630 // We're only checking for scope conflicts here, not also for violations
11631 // of the linkage rules.
11632 else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
11633 !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
11638 assert(IsInstantiation && "no scope in non-instantiation");
11639 if (CurContext->isRecord())
11640 LookupQualifiedName(Previous, CurContext);
11642 // No redeclaration check is needed here; in non-member contexts we
11643 // diagnosed all possible conflicts with other using-declarations when
11644 // building the template:
11646 // For a dependent non-type using declaration, the only valid case is
11647 // if we instantiate to a single enumerator. We check for conflicts
11648 // between shadow declarations we introduce, and we check in the template
11649 // definition for conflicts between a non-type using declaration and any
11650 // other declaration, which together covers all cases.
11652 // A dependent typename using declaration will never successfully
11653 // instantiate, since it will always name a class member, so we reject
11654 // that in the template definition.
11658 // Check for invalid redeclarations.
11659 if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
11660 SS, IdentLoc, Previous))
11663 // Check for bad qualifiers.
11664 if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
11668 DeclContext *LookupContext = computeDeclContext(SS);
11670 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
11671 if (!LookupContext || EllipsisLoc.isValid()) {
11672 if (HasTypenameKeyword) {
11673 // FIXME: not all declaration name kinds are legal here
11674 D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
11675 UsingLoc, TypenameLoc,
11677 IdentLoc, NameInfo.getName(),
11680 D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
11681 QualifierLoc, NameInfo, EllipsisLoc);
11684 CurContext->addDecl(D);
11688 auto Build = [&](bool Invalid) {
11690 UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
11691 UsingName, HasTypenameKeyword);
11693 CurContext->addDecl(UD);
11694 UD->setInvalidDecl(Invalid);
11697 auto BuildInvalid = [&]{ return Build(true); };
11698 auto BuildValid = [&]{ return Build(false); };
11700 if (RequireCompleteDeclContext(SS, LookupContext))
11701 return BuildInvalid();
11703 // Look up the target name.
11704 LookupResult R(*this, NameInfo, LookupOrdinaryName);
11706 // Unlike most lookups, we don't always want to hide tag
11707 // declarations: tag names are visible through the using declaration
11708 // even if hidden by ordinary names, *except* in a dependent context
11709 // where it's important for the sanity of two-phase lookup.
11710 if (!IsInstantiation)
11711 R.setHideTags(false);
11713 // For the purposes of this lookup, we have a base object type
11714 // equal to that of the current context.
11715 if (CurContext->isRecord()) {
11716 R.setBaseObjectType(
11717 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
11720 LookupQualifiedName(R, LookupContext);
11722 // Try to correct typos if possible. If constructor name lookup finds no
11723 // results, that means the named class has no explicit constructors, and we
11724 // suppressed declaring implicit ones (probably because it's dependent or
11727 NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
11728 // HACK: Work around a bug in libstdc++'s detection of ::gets. Sometimes
11729 // it will believe that glibc provides a ::gets in cases where it does not,
11730 // and will try to pull it into namespace std with a using-declaration.
11731 // Just ignore the using-declaration in that case.
11732 auto *II = NameInfo.getName().getAsIdentifierInfo();
11733 if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
11734 CurContext->isStdNamespace() &&
11735 isa<TranslationUnitDecl>(LookupContext) &&
11736 getSourceManager().isInSystemHeader(UsingLoc))
11738 UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
11739 dyn_cast<CXXRecordDecl>(CurContext));
11740 if (TypoCorrection Corrected =
11741 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
11742 CTK_ErrorRecovery)) {
11743 // We reject candidates where DroppedSpecifier == true, hence the
11744 // literal '0' below.
11745 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
11746 << NameInfo.getName() << LookupContext << 0
11749 // If we picked a correction with no attached Decl we can't do anything
11750 // useful with it, bail out.
11751 NamedDecl *ND = Corrected.getCorrectionDecl();
11753 return BuildInvalid();
11755 // If we corrected to an inheriting constructor, handle it as one.
11756 auto *RD = dyn_cast<CXXRecordDecl>(ND);
11757 if (RD && RD->isInjectedClassName()) {
11758 // The parent of the injected class name is the class itself.
11759 RD = cast<CXXRecordDecl>(RD->getParent());
11761 // Fix up the information we'll use to build the using declaration.
11762 if (Corrected.WillReplaceSpecifier()) {
11763 NestedNameSpecifierLocBuilder Builder;
11764 Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
11765 QualifierLoc.getSourceRange());
11766 QualifierLoc = Builder.getWithLocInContext(Context);
11769 // In this case, the name we introduce is the name of a derived class
11771 auto *CurClass = cast<CXXRecordDecl>(CurContext);
11772 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
11773 Context.getCanonicalType(Context.getRecordType(CurClass))));
11774 UsingName.setNamedTypeInfo(nullptr);
11775 for (auto *Ctor : LookupConstructors(RD))
11779 // FIXME: Pick up all the declarations if we found an overloaded
11781 UsingName.setName(ND->getDeclName());
11785 Diag(IdentLoc, diag::err_no_member)
11786 << NameInfo.getName() << LookupContext << SS.getRange();
11787 return BuildInvalid();
11791 if (R.isAmbiguous())
11792 return BuildInvalid();
11794 if (HasTypenameKeyword) {
11795 // If we asked for a typename and got a non-type decl, error out.
11796 if (!R.getAsSingle<TypeDecl>()) {
11797 Diag(IdentLoc, diag::err_using_typename_non_type);
11798 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
11799 Diag((*I)->getUnderlyingDecl()->getLocation(),
11800 diag::note_using_decl_target);
11801 return BuildInvalid();
11804 // If we asked for a non-typename and we got a type, error out,
11805 // but only if this is an instantiation of an unresolved using
11806 // decl. Otherwise just silently find the type name.
11807 if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
11808 Diag(IdentLoc, diag::err_using_dependent_value_is_type);
11809 Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
11810 return BuildInvalid();
11814 // C++14 [namespace.udecl]p6:
11815 // A using-declaration shall not name a namespace.
11816 if (R.getAsSingle<NamespaceDecl>()) {
11817 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
11819 return BuildInvalid();
11822 // C++14 [namespace.udecl]p7:
11823 // A using-declaration shall not name a scoped enumerator.
11824 if (auto *ED = R.getAsSingle<EnumConstantDecl>()) {
11825 if (cast<EnumDecl>(ED->getDeclContext())->isScoped()) {
11826 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_scoped_enum)
11828 return BuildInvalid();
11832 UsingDecl *UD = BuildValid();
11834 // Some additional rules apply to inheriting constructors.
11835 if (UsingName.getName().getNameKind() ==
11836 DeclarationName::CXXConstructorName) {
11837 // Suppress access diagnostics; the access check is instead performed at the
11838 // point of use for an inheriting constructor.
11839 R.suppressDiagnostics();
11840 if (CheckInheritingConstructorUsingDecl(UD))
11844 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
11845 UsingShadowDecl *PrevDecl = nullptr;
11846 if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
11847 BuildUsingShadowDecl(S, UD, *I, PrevDecl);
11853 NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
11854 ArrayRef<NamedDecl *> Expansions) {
11855 assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||
11856 isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||
11857 isa<UsingPackDecl>(InstantiatedFrom));
11860 UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
11861 UPD->setAccess(InstantiatedFrom->getAccess());
11862 CurContext->addDecl(UPD);
11866 /// Additional checks for a using declaration referring to a constructor name.
11867 bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
11868 assert(!UD->hasTypename() && "expecting a constructor name");
11870 const Type *SourceType = UD->getQualifier()->getAsType();
11871 assert(SourceType &&
11872 "Using decl naming constructor doesn't have type in scope spec.");
11873 CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
11875 // Check whether the named type is a direct base class.
11876 bool AnyDependentBases = false;
11877 auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
11878 AnyDependentBases);
11879 if (!Base && !AnyDependentBases) {
11880 Diag(UD->getUsingLoc(),
11881 diag::err_using_decl_constructor_not_in_direct_base)
11882 << UD->getNameInfo().getSourceRange()
11883 << QualType(SourceType, 0) << TargetClass;
11884 UD->setInvalidDecl();
11889 Base->setInheritConstructors();
11894 /// Checks that the given using declaration is not an invalid
11895 /// redeclaration. Note that this is checking only for the using decl
11896 /// itself, not for any ill-formedness among the UsingShadowDecls.
11897 bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
11898 bool HasTypenameKeyword,
11899 const CXXScopeSpec &SS,
11900 SourceLocation NameLoc,
11901 const LookupResult &Prev) {
11902 NestedNameSpecifier *Qual = SS.getScopeRep();
11904 // C++03 [namespace.udecl]p8:
11905 // C++0x [namespace.udecl]p10:
11906 // A using-declaration is a declaration and can therefore be used
11907 // repeatedly where (and only where) multiple declarations are
11910 // That's in non-member contexts.
11911 if (!CurContext->getRedeclContext()->isRecord()) {
11912 // A dependent qualifier outside a class can only ever resolve to an
11913 // enumeration type. Therefore it conflicts with any other non-type
11914 // declaration in the same scope.
11915 // FIXME: How should we check for dependent type-type conflicts at block
11917 if (Qual->isDependent() && !HasTypenameKeyword) {
11918 for (auto *D : Prev) {
11919 if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
11920 bool OldCouldBeEnumerator =
11921 isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
11923 OldCouldBeEnumerator ? diag::err_redefinition
11924 : diag::err_redefinition_different_kind)
11925 << Prev.getLookupName();
11926 Diag(D->getLocation(), diag::note_previous_definition);
11934 for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
11938 NestedNameSpecifier *DQual;
11939 if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
11940 DTypename = UD->hasTypename();
11941 DQual = UD->getQualifier();
11942 } else if (UnresolvedUsingValueDecl *UD
11943 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
11945 DQual = UD->getQualifier();
11946 } else if (UnresolvedUsingTypenameDecl *UD
11947 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
11949 DQual = UD->getQualifier();
11952 // using decls differ if one says 'typename' and the other doesn't.
11953 // FIXME: non-dependent using decls?
11954 if (HasTypenameKeyword != DTypename) continue;
11956 // using decls differ if they name different scopes (but note that
11957 // template instantiation can cause this check to trigger when it
11958 // didn't before instantiation).
11959 if (Context.getCanonicalNestedNameSpecifier(Qual) !=
11960 Context.getCanonicalNestedNameSpecifier(DQual))
11963 Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
11964 Diag(D->getLocation(), diag::note_using_decl) << 1;
11972 /// Checks that the given nested-name qualifier used in a using decl
11973 /// in the current context is appropriately related to the current
11974 /// scope. If an error is found, diagnoses it and returns true.
11975 bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
11977 const CXXScopeSpec &SS,
11978 const DeclarationNameInfo &NameInfo,
11979 SourceLocation NameLoc) {
11980 DeclContext *NamedContext = computeDeclContext(SS);
11982 if (!CurContext->isRecord()) {
11983 // C++03 [namespace.udecl]p3:
11984 // C++0x [namespace.udecl]p8:
11985 // A using-declaration for a class member shall be a member-declaration.
11987 // If we weren't able to compute a valid scope, it might validly be a
11988 // dependent class scope or a dependent enumeration unscoped scope. If
11989 // we have a 'typename' keyword, the scope must resolve to a class type.
11990 if ((HasTypename && !NamedContext) ||
11991 (NamedContext && NamedContext->getRedeclContext()->isRecord())) {
11992 auto *RD = NamedContext
11993 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
11995 if (RD && RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), RD))
11998 Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
12001 // If we have a complete, non-dependent source type, try to suggest a
12002 // way to get the same effect.
12006 // Find what this using-declaration was referring to.
12007 LookupResult R(*this, NameInfo, LookupOrdinaryName);
12008 R.setHideTags(false);
12009 R.suppressDiagnostics();
12010 LookupQualifiedName(R, RD);
12012 if (R.getAsSingle<TypeDecl>()) {
12013 if (getLangOpts().CPlusPlus11) {
12014 // Convert 'using X::Y;' to 'using Y = X::Y;'.
12015 Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
12016 << 0 // alias declaration
12017 << FixItHint::CreateInsertion(SS.getBeginLoc(),
12018 NameInfo.getName().getAsString() +
12021 // Convert 'using X::Y;' to 'typedef X::Y Y;'.
12022 SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
12023 Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
12024 << 1 // typedef declaration
12025 << FixItHint::CreateReplacement(UsingLoc, "typedef")
12026 << FixItHint::CreateInsertion(
12027 InsertLoc, " " + NameInfo.getName().getAsString());
12029 } else if (R.getAsSingle<VarDecl>()) {
12030 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12031 // repeating the type of the static data member here.
12033 if (getLangOpts().CPlusPlus11) {
12034 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12035 FixIt = FixItHint::CreateReplacement(
12036 UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
12039 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12040 << 2 // reference declaration
12042 } else if (R.getAsSingle<EnumConstantDecl>()) {
12043 // Don't provide a fixit outside C++11 mode; we don't want to suggest
12044 // repeating the type of the enumeration here, and we can't do so if
12045 // the type is anonymous.
12047 if (getLangOpts().CPlusPlus11) {
12048 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
12049 FixIt = FixItHint::CreateReplacement(
12051 "constexpr auto " + NameInfo.getName().getAsString() + " = ");
12054 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
12055 << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
12061 // Otherwise, this might be valid.
12065 // The current scope is a record.
12067 // If the named context is dependent, we can't decide much.
12068 if (!NamedContext) {
12069 // FIXME: in C++0x, we can diagnose if we can prove that the
12070 // nested-name-specifier does not refer to a base class, which is
12071 // still possible in some cases.
12073 // Otherwise we have to conservatively report that things might be
12078 if (!NamedContext->isRecord()) {
12079 // Ideally this would point at the last name in the specifier,
12080 // but we don't have that level of source info.
12081 Diag(SS.getRange().getBegin(),
12082 diag::err_using_decl_nested_name_specifier_is_not_class)
12083 << SS.getScopeRep() << SS.getRange();
12087 if (!NamedContext->isDependentContext() &&
12088 RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
12091 if (getLangOpts().CPlusPlus11) {
12092 // C++11 [namespace.udecl]p3:
12093 // In a using-declaration used as a member-declaration, the
12094 // nested-name-specifier shall name a base class of the class
12097 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
12098 cast<CXXRecordDecl>(NamedContext))) {
12099 if (CurContext == NamedContext) {
12101 diag::err_using_decl_nested_name_specifier_is_current_class)
12106 if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
12107 Diag(SS.getRange().getBegin(),
12108 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12109 << SS.getScopeRep()
12110 << cast<CXXRecordDecl>(CurContext)
12119 // C++03 [namespace.udecl]p4:
12120 // A using-declaration used as a member-declaration shall refer
12121 // to a member of a base class of the class being defined [etc.].
12123 // Salient point: SS doesn't have to name a base class as long as
12124 // lookup only finds members from base classes. Therefore we can
12125 // diagnose here only if we can prove that that can't happen,
12126 // i.e. if the class hierarchies provably don't intersect.
12128 // TODO: it would be nice if "definitely valid" results were cached
12129 // in the UsingDecl and UsingShadowDecl so that these checks didn't
12130 // need to be repeated.
12132 llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
12133 auto Collect = [&Bases](const CXXRecordDecl *Base) {
12134 Bases.insert(Base);
12138 // Collect all bases. Return false if we find a dependent base.
12139 if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
12142 // Returns true if the base is dependent or is one of the accumulated base
12144 auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
12145 return !Bases.count(Base);
12148 // Return false if the class has a dependent base or if it or one
12149 // of its bases is present in the base set of the current context.
12150 if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
12151 !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
12154 Diag(SS.getRange().getBegin(),
12155 diag::err_using_decl_nested_name_specifier_is_not_base_class)
12156 << SS.getScopeRep()
12157 << cast<CXXRecordDecl>(CurContext)
12163 Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
12164 MultiTemplateParamsArg TemplateParamLists,
12165 SourceLocation UsingLoc, UnqualifiedId &Name,
12166 const ParsedAttributesView &AttrList,
12167 TypeResult Type, Decl *DeclFromDeclSpec) {
12168 // Skip up to the relevant declaration scope.
12169 while (S->isTemplateParamScope())
12170 S = S->getParent();
12171 assert((S->getFlags() & Scope::DeclScope) &&
12172 "got alias-declaration outside of declaration scope");
12174 if (Type.isInvalid())
12177 bool Invalid = false;
12178 DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
12179 TypeSourceInfo *TInfo = nullptr;
12180 GetTypeFromParser(Type.get(), &TInfo);
12182 if (DiagnoseClassNameShadow(CurContext, NameInfo))
12185 if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
12186 UPPC_DeclarationType)) {
12188 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
12189 TInfo->getTypeLoc().getBeginLoc());
12192 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
12193 TemplateParamLists.size()
12194 ? forRedeclarationInCurContext()
12195 : ForVisibleRedeclaration);
12196 LookupName(Previous, S);
12198 // Warn about shadowing the name of a template parameter.
12199 if (Previous.isSingleResult() &&
12200 Previous.getFoundDecl()->isTemplateParameter()) {
12201 DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
12205 assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&
12206 "name in alias declaration must be an identifier");
12207 TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
12208 Name.StartLocation,
12209 Name.Identifier, TInfo);
12211 NewTD->setAccess(AS);
12214 NewTD->setInvalidDecl();
12216 ProcessDeclAttributeList(S, NewTD, AttrList);
12217 AddPragmaAttributes(S, NewTD);
12219 CheckTypedefForVariablyModifiedType(S, NewTD);
12220 Invalid |= NewTD->isInvalidDecl();
12222 bool Redeclaration = false;
12225 if (TemplateParamLists.size()) {
12226 TypeAliasTemplateDecl *OldDecl = nullptr;
12227 TemplateParameterList *OldTemplateParams = nullptr;
12229 if (TemplateParamLists.size() != 1) {
12230 Diag(UsingLoc, diag::err_alias_template_extra_headers)
12231 << SourceRange(TemplateParamLists[1]->getTemplateLoc(),
12232 TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
12234 TemplateParameterList *TemplateParams = TemplateParamLists[0];
12236 // Check that we can declare a template here.
12237 if (CheckTemplateDeclScope(S, TemplateParams))
12240 // Only consider previous declarations in the same scope.
12241 FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
12242 /*ExplicitInstantiationOrSpecialization*/false);
12243 if (!Previous.empty()) {
12244 Redeclaration = true;
12246 OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
12247 if (!OldDecl && !Invalid) {
12248 Diag(UsingLoc, diag::err_redefinition_different_kind)
12249 << Name.Identifier;
12251 NamedDecl *OldD = Previous.getRepresentativeDecl();
12252 if (OldD->getLocation().isValid())
12253 Diag(OldD->getLocation(), diag::note_previous_definition);
12258 if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
12259 if (TemplateParameterListsAreEqual(TemplateParams,
12260 OldDecl->getTemplateParameters(),
12262 TPL_TemplateMatch))
12263 OldTemplateParams =
12264 OldDecl->getMostRecentDecl()->getTemplateParameters();
12268 TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
12270 !Context.hasSameType(OldTD->getUnderlyingType(),
12271 NewTD->getUnderlyingType())) {
12272 // FIXME: The C++0x standard does not clearly say this is ill-formed,
12273 // but we can't reasonably accept it.
12274 Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
12275 << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
12276 if (OldTD->getLocation().isValid())
12277 Diag(OldTD->getLocation(), diag::note_previous_definition);
12283 // Merge any previous default template arguments into our parameters,
12284 // and check the parameter list.
12285 if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
12286 TPC_TypeAliasTemplate))
12289 TypeAliasTemplateDecl *NewDecl =
12290 TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
12291 Name.Identifier, TemplateParams,
12293 NewTD->setDescribedAliasTemplate(NewDecl);
12295 NewDecl->setAccess(AS);
12298 NewDecl->setInvalidDecl();
12299 else if (OldDecl) {
12300 NewDecl->setPreviousDecl(OldDecl);
12301 CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
12306 if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
12307 setTagNameForLinkagePurposes(TD, NewTD);
12308 handleTagNumbering(TD, S);
12310 ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
12314 PushOnScopeChains(NewND, S);
12315 ActOnDocumentableDecl(NewND);
12319 Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
12320 SourceLocation AliasLoc,
12321 IdentifierInfo *Alias, CXXScopeSpec &SS,
12322 SourceLocation IdentLoc,
12323 IdentifierInfo *Ident) {
12325 // Lookup the namespace name.
12326 LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
12327 LookupParsedName(R, S, &SS);
12329 if (R.isAmbiguous())
12333 if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
12334 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
12338 assert(!R.isAmbiguous() && !R.empty());
12339 NamedDecl *ND = R.getRepresentativeDecl();
12341 // Check if we have a previous declaration with the same name.
12342 LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
12343 ForVisibleRedeclaration);
12344 LookupName(PrevR, S);
12346 // Check we're not shadowing a template parameter.
12347 if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
12348 DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
12352 // Filter out any other lookup result from an enclosing scope.
12353 FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
12354 /*AllowInlineNamespace*/false);
12356 // Find the previous declaration and check that we can redeclare it.
12357 NamespaceAliasDecl *Prev = nullptr;
12358 if (PrevR.isSingleResult()) {
12359 NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
12360 if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
12361 // We already have an alias with the same name that points to the same
12362 // namespace; check that it matches.
12363 if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
12365 } else if (isVisible(PrevDecl)) {
12366 Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
12368 Diag(AD->getLocation(), diag::note_previous_namespace_alias)
12369 << AD->getNamespace();
12372 } else if (isVisible(PrevDecl)) {
12373 unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
12374 ? diag::err_redefinition
12375 : diag::err_redefinition_different_kind;
12376 Diag(AliasLoc, DiagID) << Alias;
12377 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
12382 // The use of a nested name specifier may trigger deprecation warnings.
12383 DiagnoseUseOfDecl(ND, IdentLoc);
12385 NamespaceAliasDecl *AliasDecl =
12386 NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
12387 Alias, SS.getWithLocInContext(Context),
12390 AliasDecl->setPreviousDecl(Prev);
12392 PushOnScopeChains(AliasDecl, S);
12397 struct SpecialMemberExceptionSpecInfo
12398 : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
12399 SourceLocation Loc;
12400 Sema::ImplicitExceptionSpecification ExceptSpec;
12402 SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
12403 Sema::CXXSpecialMember CSM,
12404 Sema::InheritedConstructorInfo *ICI,
12405 SourceLocation Loc)
12406 : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}
12408 bool visitBase(CXXBaseSpecifier *Base);
12409 bool visitField(FieldDecl *FD);
12411 void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
12414 void visitSubobjectCall(Subobject Subobj,
12415 Sema::SpecialMemberOverloadResult SMOR);
12419 bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
12420 auto *RT = Base->getType()->getAs<RecordType>();
12424 auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
12425 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
12426 if (auto *BaseCtor = SMOR.getMethod()) {
12427 visitSubobjectCall(Base, BaseCtor);
12431 visitClassSubobject(BaseClass, Base, 0);
12435 bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
12436 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
12437 Expr *E = FD->getInClassInitializer();
12439 // FIXME: It's a little wasteful to build and throw away a
12440 // CXXDefaultInitExpr here.
12441 // FIXME: We should have a single context note pointing at Loc, and
12442 // this location should be MD->getLocation() instead, since that's
12443 // the location where we actually use the default init expression.
12444 E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
12446 ExceptSpec.CalledExpr(E);
12447 } else if (auto *RT = S.Context.getBaseElementType(FD->getType())
12448 ->getAs<RecordType>()) {
12449 visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
12450 FD->getType().getCVRQualifiers());
12455 void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
12458 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
12459 bool IsMutable = Field && Field->isMutable();
12460 visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
12463 void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
12464 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
12465 // Note, if lookup fails, it doesn't matter what exception specification we
12466 // choose because the special member will be deleted.
12467 if (CXXMethodDecl *MD = SMOR.getMethod())
12468 ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
12471 bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
12472 llvm::APSInt Result;
12473 ExprResult Converted = CheckConvertedConstantExpression(
12474 ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
12475 ExplicitSpec.setExpr(Converted.get());
12476 if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
12477 ExplicitSpec.setKind(Result.getBoolValue()
12478 ? ExplicitSpecKind::ResolvedTrue
12479 : ExplicitSpecKind::ResolvedFalse);
12482 ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
12486 ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
12487 ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
12488 if (!ExplicitExpr->isTypeDependent())
12489 tryResolveExplicitSpecifier(ES);
12493 static Sema::ImplicitExceptionSpecification
12494 ComputeDefaultedSpecialMemberExceptionSpec(
12495 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
12496 Sema::InheritedConstructorInfo *ICI) {
12497 ComputingExceptionSpec CES(S, MD, Loc);
12499 CXXRecordDecl *ClassDecl = MD->getParent();
12501 // C++ [except.spec]p14:
12502 // An implicitly declared special member function (Clause 12) shall have an
12503 // exception-specification. [...]
12504 SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
12505 if (ClassDecl->isInvalidDecl())
12506 return Info.ExceptSpec;
12508 // FIXME: If this diagnostic fires, we're probably missing a check for
12509 // attempting to resolve an exception specification before it's known
12510 // at a higher level.
12511 if (S.RequireCompleteType(MD->getLocation(),
12512 S.Context.getRecordType(ClassDecl),
12513 diag::err_exception_spec_incomplete_type))
12514 return Info.ExceptSpec;
12516 // C++1z [except.spec]p7:
12517 // [Look for exceptions thrown by] a constructor selected [...] to
12518 // initialize a potentially constructed subobject,
12519 // C++1z [except.spec]p8:
12520 // The exception specification for an implicitly-declared destructor, or a
12521 // destructor without a noexcept-specifier, is potentially-throwing if and
12522 // only if any of the destructors for any of its potentially constructed
12523 // subojects is potentially throwing.
12524 // FIXME: We respect the first rule but ignore the "potentially constructed"
12525 // in the second rule to resolve a core issue (no number yet) that would have
12527 // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
12528 // struct B : A {};
12529 // struct C : B { void f(); };
12530 // ... due to giving B::~B() a non-throwing exception specification.
12531 Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
12532 : Info.VisitAllBases);
12534 return Info.ExceptSpec;
12538 /// RAII object to register a special member as being currently declared.
12539 struct DeclaringSpecialMember {
12541 Sema::SpecialMemberDecl D;
12542 Sema::ContextRAII SavedContext;
12543 bool WasAlreadyBeingDeclared;
12545 DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
12546 : S(S), D(RD, CSM), SavedContext(S, RD) {
12547 WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
12548 if (WasAlreadyBeingDeclared)
12549 // This almost never happens, but if it does, ensure that our cache
12550 // doesn't contain a stale result.
12551 S.SpecialMemberCache.clear();
12553 // Register a note to be produced if we encounter an error while
12554 // declaring the special member.
12555 Sema::CodeSynthesisContext Ctx;
12556 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
12557 // FIXME: We don't have a location to use here. Using the class's
12558 // location maintains the fiction that we declare all special members
12559 // with the class, but (1) it's not clear that lying about that helps our
12560 // users understand what's going on, and (2) there may be outer contexts
12561 // on the stack (some of which are relevant) and printing them exposes
12563 Ctx.PointOfInstantiation = RD->getLocation();
12565 Ctx.SpecialMember = CSM;
12566 S.pushCodeSynthesisContext(Ctx);
12569 ~DeclaringSpecialMember() {
12570 if (!WasAlreadyBeingDeclared) {
12571 S.SpecialMembersBeingDeclared.erase(D);
12572 S.popCodeSynthesisContext();
12576 /// Are we already trying to declare this special member?
12577 bool isAlreadyBeingDeclared() const {
12578 return WasAlreadyBeingDeclared;
12583 void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
12584 // Look up any existing declarations, but don't trigger declaration of all
12585 // implicit special members with this name.
12586 DeclarationName Name = FD->getDeclName();
12587 LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
12588 ForExternalRedeclaration);
12589 for (auto *D : FD->getParent()->lookup(Name))
12590 if (auto *Acceptable = R.getAcceptableDecl(D))
12591 R.addDecl(Acceptable);
12593 R.suppressDiagnostics();
12595 CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
12598 void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
12600 ArrayRef<QualType> Args) {
12601 // Build an exception specification pointing back at this constructor.
12602 FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);
12604 LangAS AS = getDefaultCXXMethodAddrSpace();
12605 if (AS != LangAS::Default) {
12606 EPI.TypeQuals.addAddressSpace(AS);
12609 auto QT = Context.getFunctionType(ResultTy, Args, EPI);
12610 SpecialMem->setType(QT);
12613 CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
12614 CXXRecordDecl *ClassDecl) {
12615 // C++ [class.ctor]p5:
12616 // A default constructor for a class X is a constructor of class X
12617 // that can be called without an argument. If there is no
12618 // user-declared constructor for class X, a default constructor is
12619 // implicitly declared. An implicitly-declared default constructor
12620 // is an inline public member of its class.
12621 assert(ClassDecl->needsImplicitDefaultConstructor() &&
12622 "Should not build implicit default constructor!");
12624 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
12625 if (DSM.isAlreadyBeingDeclared())
12628 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12629 CXXDefaultConstructor,
12632 // Create the actual constructor declaration.
12633 CanQualType ClassType
12634 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
12635 SourceLocation ClassLoc = ClassDecl->getLocation();
12636 DeclarationName Name
12637 = Context.DeclarationNames.getCXXConstructorName(ClassType);
12638 DeclarationNameInfo NameInfo(Name, ClassLoc);
12639 CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
12640 Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
12641 /*TInfo=*/nullptr, ExplicitSpecifier(),
12642 /*isInline=*/true, /*isImplicitlyDeclared=*/true,
12643 Constexpr ? CSK_constexpr : CSK_unspecified);
12644 DefaultCon->setAccess(AS_public);
12645 DefaultCon->setDefaulted();
12647 if (getLangOpts().CUDA) {
12648 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
12650 /* ConstRHS */ false,
12651 /* Diagnose */ false);
12654 setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);
12656 // We don't need to use SpecialMemberIsTrivial here; triviality for default
12657 // constructors is easy to compute.
12658 DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
12660 // Note that we have declared this constructor.
12661 ++getASTContext().NumImplicitDefaultConstructorsDeclared;
12663 Scope *S = getScopeForContext(ClassDecl);
12664 CheckImplicitSpecialMemberDeclaration(S, DefaultCon);
12666 if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
12667 SetDeclDeleted(DefaultCon, ClassLoc);
12670 PushOnScopeChains(DefaultCon, S, false);
12671 ClassDecl->addDecl(DefaultCon);
12676 void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
12677 CXXConstructorDecl *Constructor) {
12678 assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
12679 !Constructor->doesThisDeclarationHaveABody() &&
12680 !Constructor->isDeleted()) &&
12681 "DefineImplicitDefaultConstructor - call it for implicit default ctor");
12682 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
12685 CXXRecordDecl *ClassDecl = Constructor->getParent();
12686 assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
12688 SynthesizedFunctionScope Scope(*this, Constructor);
12690 // The exception specification is needed because we are defining the
12692 ResolveExceptionSpec(CurrentLocation,
12693 Constructor->getType()->castAs<FunctionProtoType>());
12694 MarkVTableUsed(CurrentLocation, ClassDecl);
12696 // Add a context note for diagnostics produced after this point.
12697 Scope.addContextNote(CurrentLocation);
12699 if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
12700 Constructor->setInvalidDecl();
12704 SourceLocation Loc = Constructor->getEndLoc().isValid()
12705 ? Constructor->getEndLoc()
12706 : Constructor->getLocation();
12707 Constructor->setBody(new (Context) CompoundStmt(Loc));
12708 Constructor->markUsed(Context);
12710 if (ASTMutationListener *L = getASTMutationListener()) {
12711 L->CompletedImplicitDefinition(Constructor);
12714 DiagnoseUninitializedFields(*this, Constructor);
12717 void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
12718 // Perform any delayed checks on exception specifications.
12719 CheckDelayedMemberExceptionSpecs();
12722 /// Find or create the fake constructor we synthesize to model constructing an
12723 /// object of a derived class via a constructor of a base class.
12724 CXXConstructorDecl *
12725 Sema::findInheritingConstructor(SourceLocation Loc,
12726 CXXConstructorDecl *BaseCtor,
12727 ConstructorUsingShadowDecl *Shadow) {
12728 CXXRecordDecl *Derived = Shadow->getParent();
12729 SourceLocation UsingLoc = Shadow->getLocation();
12731 // FIXME: Add a new kind of DeclarationName for an inherited constructor.
12732 // For now we use the name of the base class constructor as a member of the
12733 // derived class to indicate a (fake) inherited constructor name.
12734 DeclarationName Name = BaseCtor->getDeclName();
12736 // Check to see if we already have a fake constructor for this inherited
12737 // constructor call.
12738 for (NamedDecl *Ctor : Derived->lookup(Name))
12739 if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
12740 ->getInheritedConstructor()
12743 return cast<CXXConstructorDecl>(Ctor);
12745 DeclarationNameInfo NameInfo(Name, UsingLoc);
12746 TypeSourceInfo *TInfo =
12747 Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
12748 FunctionProtoTypeLoc ProtoLoc =
12749 TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();
12751 // Check the inherited constructor is valid and find the list of base classes
12752 // from which it was inherited.
12753 InheritedConstructorInfo ICI(*this, Loc, Shadow);
12756 BaseCtor->isConstexpr() &&
12757 defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
12758 false, BaseCtor, &ICI);
12760 CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
12761 Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
12762 BaseCtor->getExplicitSpecifier(), /*isInline=*/true,
12763 /*isImplicitlyDeclared=*/true,
12764 Constexpr ? BaseCtor->getConstexprKind() : CSK_unspecified,
12765 InheritedConstructor(Shadow, BaseCtor),
12766 BaseCtor->getTrailingRequiresClause());
12767 if (Shadow->isInvalidDecl())
12768 DerivedCtor->setInvalidDecl();
12770 // Build an unevaluated exception specification for this fake constructor.
12771 const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
12772 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
12773 EPI.ExceptionSpec.Type = EST_Unevaluated;
12774 EPI.ExceptionSpec.SourceDecl = DerivedCtor;
12775 DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
12776 FPT->getParamTypes(), EPI));
12778 // Build the parameter declarations.
12779 SmallVector<ParmVarDecl *, 16> ParamDecls;
12780 for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
12781 TypeSourceInfo *TInfo =
12782 Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
12783 ParmVarDecl *PD = ParmVarDecl::Create(
12784 Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
12785 FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
12786 PD->setScopeInfo(0, I);
12788 // Ensure attributes are propagated onto parameters (this matters for
12789 // format, pass_object_size, ...).
12790 mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
12791 ParamDecls.push_back(PD);
12792 ProtoLoc.setParam(I, PD);
12795 // Set up the new constructor.
12796 assert(!BaseCtor->isDeleted() && "should not use deleted constructor");
12797 DerivedCtor->setAccess(BaseCtor->getAccess());
12798 DerivedCtor->setParams(ParamDecls);
12799 Derived->addDecl(DerivedCtor);
12801 if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
12802 SetDeclDeleted(DerivedCtor, UsingLoc);
12804 return DerivedCtor;
12807 void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
12808 InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
12809 Ctor->getInheritedConstructor().getShadowDecl());
12810 ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
12814 void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
12815 CXXConstructorDecl *Constructor) {
12816 CXXRecordDecl *ClassDecl = Constructor->getParent();
12817 assert(Constructor->getInheritedConstructor() &&
12818 !Constructor->doesThisDeclarationHaveABody() &&
12819 !Constructor->isDeleted());
12820 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
12823 // Initializations are performed "as if by a defaulted default constructor",
12824 // so enter the appropriate scope.
12825 SynthesizedFunctionScope Scope(*this, Constructor);
12827 // The exception specification is needed because we are defining the
12829 ResolveExceptionSpec(CurrentLocation,
12830 Constructor->getType()->castAs<FunctionProtoType>());
12831 MarkVTableUsed(CurrentLocation, ClassDecl);
12833 // Add a context note for diagnostics produced after this point.
12834 Scope.addContextNote(CurrentLocation);
12836 ConstructorUsingShadowDecl *Shadow =
12837 Constructor->getInheritedConstructor().getShadowDecl();
12838 CXXConstructorDecl *InheritedCtor =
12839 Constructor->getInheritedConstructor().getConstructor();
12841 // [class.inhctor.init]p1:
12842 // initialization proceeds as if a defaulted default constructor is used to
12843 // initialize the D object and each base class subobject from which the
12844 // constructor was inherited
12846 InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
12847 CXXRecordDecl *RD = Shadow->getParent();
12848 SourceLocation InitLoc = Shadow->getLocation();
12850 // Build explicit initializers for all base classes from which the
12851 // constructor was inherited.
12852 SmallVector<CXXCtorInitializer*, 8> Inits;
12853 for (bool VBase : {false, true}) {
12854 for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
12855 if (B.isVirtual() != VBase)
12858 auto *BaseRD = B.getType()->getAsCXXRecordDecl();
12862 auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
12863 if (!BaseCtor.first)
12866 MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
12867 ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
12868 InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);
12870 auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
12871 Inits.push_back(new (Context) CXXCtorInitializer(
12872 Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
12873 SourceLocation()));
12877 // We now proceed as if for a defaulted default constructor, with the relevant
12878 // initializers replaced.
12880 if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
12881 Constructor->setInvalidDecl();
12885 Constructor->setBody(new (Context) CompoundStmt(InitLoc));
12886 Constructor->markUsed(Context);
12888 if (ASTMutationListener *L = getASTMutationListener()) {
12889 L->CompletedImplicitDefinition(Constructor);
12892 DiagnoseUninitializedFields(*this, Constructor);
12895 CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
12896 // C++ [class.dtor]p2:
12897 // If a class has no user-declared destructor, a destructor is
12898 // declared implicitly. An implicitly-declared destructor is an
12899 // inline public member of its class.
12900 assert(ClassDecl->needsImplicitDestructor());
12902 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
12903 if (DSM.isAlreadyBeingDeclared())
12906 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12910 // Create the actual destructor declaration.
12911 CanQualType ClassType
12912 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
12913 SourceLocation ClassLoc = ClassDecl->getLocation();
12914 DeclarationName Name
12915 = Context.DeclarationNames.getCXXDestructorName(ClassType);
12916 DeclarationNameInfo NameInfo(Name, ClassLoc);
12917 CXXDestructorDecl *Destructor =
12918 CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
12919 QualType(), nullptr, /*isInline=*/true,
12920 /*isImplicitlyDeclared=*/true,
12921 Constexpr ? CSK_constexpr : CSK_unspecified);
12922 Destructor->setAccess(AS_public);
12923 Destructor->setDefaulted();
12925 if (getLangOpts().CUDA) {
12926 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
12928 /* ConstRHS */ false,
12929 /* Diagnose */ false);
12932 setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);
12934 // We don't need to use SpecialMemberIsTrivial here; triviality for
12935 // destructors is easy to compute.
12936 Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
12937 Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
12938 ClassDecl->hasTrivialDestructorForCall());
12940 // Note that we have declared this destructor.
12941 ++getASTContext().NumImplicitDestructorsDeclared;
12943 Scope *S = getScopeForContext(ClassDecl);
12944 CheckImplicitSpecialMemberDeclaration(S, Destructor);
12946 // We can't check whether an implicit destructor is deleted before we complete
12947 // the definition of the class, because its validity depends on the alignment
12948 // of the class. We'll check this from ActOnFields once the class is complete.
12949 if (ClassDecl->isCompleteDefinition() &&
12950 ShouldDeleteSpecialMember(Destructor, CXXDestructor))
12951 SetDeclDeleted(Destructor, ClassLoc);
12953 // Introduce this destructor into its scope.
12955 PushOnScopeChains(Destructor, S, false);
12956 ClassDecl->addDecl(Destructor);
12961 void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
12962 CXXDestructorDecl *Destructor) {
12963 assert((Destructor->isDefaulted() &&
12964 !Destructor->doesThisDeclarationHaveABody() &&
12965 !Destructor->isDeleted()) &&
12966 "DefineImplicitDestructor - call it for implicit default dtor");
12967 if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
12970 CXXRecordDecl *ClassDecl = Destructor->getParent();
12971 assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
12973 SynthesizedFunctionScope Scope(*this, Destructor);
12975 // The exception specification is needed because we are defining the
12977 ResolveExceptionSpec(CurrentLocation,
12978 Destructor->getType()->castAs<FunctionProtoType>());
12979 MarkVTableUsed(CurrentLocation, ClassDecl);
12981 // Add a context note for diagnostics produced after this point.
12982 Scope.addContextNote(CurrentLocation);
12984 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
12985 Destructor->getParent());
12987 if (CheckDestructor(Destructor)) {
12988 Destructor->setInvalidDecl();
12992 SourceLocation Loc = Destructor->getEndLoc().isValid()
12993 ? Destructor->getEndLoc()
12994 : Destructor->getLocation();
12995 Destructor->setBody(new (Context) CompoundStmt(Loc));
12996 Destructor->markUsed(Context);
12998 if (ASTMutationListener *L = getASTMutationListener()) {
12999 L->CompletedImplicitDefinition(Destructor);
13003 /// Perform any semantic analysis which needs to be delayed until all
13004 /// pending class member declarations have been parsed.
13005 void Sema::ActOnFinishCXXMemberDecls() {
13006 // If the context is an invalid C++ class, just suppress these checks.
13007 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
13008 if (Record->isInvalidDecl()) {
13009 DelayedOverridingExceptionSpecChecks.clear();
13010 DelayedEquivalentExceptionSpecChecks.clear();
13013 checkForMultipleExportedDefaultConstructors(*this, Record);
13017 void Sema::ActOnFinishCXXNonNestedClass() {
13018 referenceDLLExportedClassMethods();
13020 if (!DelayedDllExportMemberFunctions.empty()) {
13021 SmallVector<CXXMethodDecl*, 4> WorkList;
13022 std::swap(DelayedDllExportMemberFunctions, WorkList);
13023 for (CXXMethodDecl *M : WorkList) {
13024 DefineImplicitSpecialMember(*this, M, M->getLocation());
13026 // Pass the method to the consumer to get emitted. This is not necessary
13027 // for explicit instantiation definitions, as they will get emitted
13029 if (M->getParent()->getTemplateSpecializationKind() !=
13030 TSK_ExplicitInstantiationDefinition)
13031 ActOnFinishInlineFunctionDef(M);
13036 void Sema::referenceDLLExportedClassMethods() {
13037 if (!DelayedDllExportClasses.empty()) {
13038 // Calling ReferenceDllExportedMembers might cause the current function to
13039 // be called again, so use a local copy of DelayedDllExportClasses.
13040 SmallVector<CXXRecordDecl *, 4> WorkList;
13041 std::swap(DelayedDllExportClasses, WorkList);
13042 for (CXXRecordDecl *Class : WorkList)
13043 ReferenceDllExportedMembers(*this, Class);
13047 void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
13048 assert(getLangOpts().CPlusPlus11 &&
13049 "adjusting dtor exception specs was introduced in c++11");
13051 if (Destructor->isDependentContext())
13054 // C++11 [class.dtor]p3:
13055 // A declaration of a destructor that does not have an exception-
13056 // specification is implicitly considered to have the same exception-
13057 // specification as an implicit declaration.
13058 const auto *DtorType = Destructor->getType()->castAs<FunctionProtoType>();
13059 if (DtorType->hasExceptionSpec())
13062 // Replace the destructor's type, building off the existing one. Fortunately,
13063 // the only thing of interest in the destructor type is its extended info.
13064 // The return and arguments are fixed.
13065 FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
13066 EPI.ExceptionSpec.Type = EST_Unevaluated;
13067 EPI.ExceptionSpec.SourceDecl = Destructor;
13068 Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI));
13070 // FIXME: If the destructor has a body that could throw, and the newly created
13071 // spec doesn't allow exceptions, we should emit a warning, because this
13072 // change in behavior can break conforming C++03 programs at runtime.
13073 // However, we don't have a body or an exception specification yet, so it
13074 // needs to be done somewhere else.
13078 /// An abstract base class for all helper classes used in building the
13079 // copy/move operators. These classes serve as factory functions and help us
13080 // avoid using the same Expr* in the AST twice.
13081 class ExprBuilder {
13082 ExprBuilder(const ExprBuilder&) = delete;
13083 ExprBuilder &operator=(const ExprBuilder&) = delete;
13086 static Expr *assertNotNull(Expr *E) {
13087 assert(E && "Expression construction must not fail.");
13093 virtual ~ExprBuilder() {}
13095 virtual Expr *build(Sema &S, SourceLocation Loc) const = 0;
13098 class RefBuilder: public ExprBuilder {
13103 Expr *build(Sema &S, SourceLocation Loc) const override {
13104 return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc));
13107 RefBuilder(VarDecl *Var, QualType VarType)
13108 : Var(Var), VarType(VarType) {}
13111 class ThisBuilder: public ExprBuilder {
13113 Expr *build(Sema &S, SourceLocation Loc) const override {
13114 return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>());
13118 class CastBuilder: public ExprBuilder {
13119 const ExprBuilder &Builder;
13121 ExprValueKind Kind;
13122 const CXXCastPath &Path;
13125 Expr *build(Sema &S, SourceLocation Loc) const override {
13126 return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type,
13127 CK_UncheckedDerivedToBase, Kind,
13131 CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind,
13132 const CXXCastPath &Path)
13133 : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {}
13136 class DerefBuilder: public ExprBuilder {
13137 const ExprBuilder &Builder;
13140 Expr *build(Sema &S, SourceLocation Loc) const override {
13141 return assertNotNull(
13142 S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get());
13145 DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13148 class MemberBuilder: public ExprBuilder {
13149 const ExprBuilder &Builder;
13153 LookupResult &MemberLookup;
13156 Expr *build(Sema &S, SourceLocation Loc) const override {
13157 return assertNotNull(S.BuildMemberReferenceExpr(
13158 Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(),
13159 nullptr, MemberLookup, nullptr, nullptr).get());
13162 MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow,
13163 LookupResult &MemberLookup)
13164 : Builder(Builder), Type(Type), IsArrow(IsArrow),
13165 MemberLookup(MemberLookup) {}
13168 class MoveCastBuilder: public ExprBuilder {
13169 const ExprBuilder &Builder;
13172 Expr *build(Sema &S, SourceLocation Loc) const override {
13173 return assertNotNull(CastForMoving(S, Builder.build(S, Loc)));
13176 MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13179 class LvalueConvBuilder: public ExprBuilder {
13180 const ExprBuilder &Builder;
13183 Expr *build(Sema &S, SourceLocation Loc) const override {
13184 return assertNotNull(
13185 S.DefaultLvalueConversion(Builder.build(S, Loc)).get());
13188 LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
13191 class SubscriptBuilder: public ExprBuilder {
13192 const ExprBuilder &Base;
13193 const ExprBuilder &Index;
13196 Expr *build(Sema &S, SourceLocation Loc) const override {
13197 return assertNotNull(S.CreateBuiltinArraySubscriptExpr(
13198 Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get());
13201 SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index)
13202 : Base(Base), Index(Index) {}
13205 } // end anonymous namespace
13207 /// When generating a defaulted copy or move assignment operator, if a field
13208 /// should be copied with __builtin_memcpy rather than via explicit assignments,
13209 /// do so. This optimization only applies for arrays of scalars, and for arrays
13210 /// of class type where the selected copy/move-assignment operator is trivial.
13212 buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T,
13213 const ExprBuilder &ToB, const ExprBuilder &FromB) {
13214 // Compute the size of the memory buffer to be copied.
13215 QualType SizeType = S.Context.getSizeType();
13216 llvm::APInt Size(S.Context.getTypeSize(SizeType),
13217 S.Context.getTypeSizeInChars(T).getQuantity());
13219 // Take the address of the field references for "from" and "to". We
13220 // directly construct UnaryOperators here because semantic analysis
13221 // does not permit us to take the address of an xvalue.
13222 Expr *From = FromB.build(S, Loc);
13223 From = new (S.Context) UnaryOperator(From, UO_AddrOf,
13224 S.Context.getPointerType(From->getType()),
13225 VK_RValue, OK_Ordinary, Loc, false);
13226 Expr *To = ToB.build(S, Loc);
13227 To = new (S.Context) UnaryOperator(To, UO_AddrOf,
13228 S.Context.getPointerType(To->getType()),
13229 VK_RValue, OK_Ordinary, Loc, false);
13231 const Type *E = T->getBaseElementTypeUnsafe();
13232 bool NeedsCollectableMemCpy =
13233 E->isRecordType() &&
13234 E->castAs<RecordType>()->getDecl()->hasObjectMember();
13236 // Create a reference to the __builtin_objc_memmove_collectable function
13237 StringRef MemCpyName = NeedsCollectableMemCpy ?
13238 "__builtin_objc_memmove_collectable" :
13239 "__builtin_memcpy";
13240 LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
13241 Sema::LookupOrdinaryName);
13242 S.LookupName(R, S.TUScope, true);
13244 FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
13246 // Something went horribly wrong earlier, and we will have complained
13248 return StmtError();
13250 ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
13251 VK_RValue, Loc, nullptr);
13252 assert(MemCpyRef.isUsable() && "Builtin reference cannot fail");
13254 Expr *CallArgs[] = {
13255 To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
13257 ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(),
13258 Loc, CallArgs, Loc);
13260 assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
13261 return Call.getAs<Stmt>();
13264 /// Builds a statement that copies/moves the given entity from \p From to
13267 /// This routine is used to copy/move the members of a class with an
13268 /// implicitly-declared copy/move assignment operator. When the entities being
13269 /// copied are arrays, this routine builds for loops to copy them.
13271 /// \param S The Sema object used for type-checking.
13273 /// \param Loc The location where the implicit copy/move is being generated.
13275 /// \param T The type of the expressions being copied/moved. Both expressions
13276 /// must have this type.
13278 /// \param To The expression we are copying/moving to.
13280 /// \param From The expression we are copying/moving from.
13282 /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
13283 /// Otherwise, it's a non-static member subobject.
13285 /// \param Copying Whether we're copying or moving.
13287 /// \param Depth Internal parameter recording the depth of the recursion.
13289 /// \returns A statement or a loop that copies the expressions, or StmtResult(0)
13290 /// if a memcpy should be used instead.
13292 buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T,
13293 const ExprBuilder &To, const ExprBuilder &From,
13294 bool CopyingBaseSubobject, bool Copying,
13295 unsigned Depth = 0) {
13296 // C++11 [class.copy]p28:
13297 // Each subobject is assigned in the manner appropriate to its type:
13299 // - if the subobject is of class type, as if by a call to operator= with
13300 // the subobject as the object expression and the corresponding
13301 // subobject of x as a single function argument (as if by explicit
13302 // qualification; that is, ignoring any possible virtual overriding
13303 // functions in more derived classes);
13305 // C++03 [class.copy]p13:
13306 // - if the subobject is of class type, the copy assignment operator for
13307 // the class is used (as if by explicit qualification; that is,
13308 // ignoring any possible virtual overriding functions in more derived
13310 if (const RecordType *RecordTy = T->getAs<RecordType>()) {
13311 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
13313 // Look for operator=.
13314 DeclarationName Name
13315 = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13316 LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
13317 S.LookupQualifiedName(OpLookup, ClassDecl, false);
13319 // Prior to C++11, filter out any result that isn't a copy/move-assignment
13321 if (!S.getLangOpts().CPlusPlus11) {
13322 LookupResult::Filter F = OpLookup.makeFilter();
13323 while (F.hasNext()) {
13324 NamedDecl *D = F.next();
13325 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
13326 if (Method->isCopyAssignmentOperator() ||
13327 (!Copying && Method->isMoveAssignmentOperator()))
13335 // Suppress the protected check (C++ [class.protected]) for each of the
13336 // assignment operators we found. This strange dance is required when
13337 // we're assigning via a base classes's copy-assignment operator. To
13338 // ensure that we're getting the right base class subobject (without
13339 // ambiguities), we need to cast "this" to that subobject type; to
13340 // ensure that we don't go through the virtual call mechanism, we need
13341 // to qualify the operator= name with the base class (see below). However,
13342 // this means that if the base class has a protected copy assignment
13343 // operator, the protected member access check will fail. So, we
13344 // rewrite "protected" access to "public" access in this case, since we
13345 // know by construction that we're calling from a derived class.
13346 if (CopyingBaseSubobject) {
13347 for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
13349 if (L.getAccess() == AS_protected)
13350 L.setAccess(AS_public);
13354 // Create the nested-name-specifier that will be used to qualify the
13355 // reference to operator=; this is required to suppress the virtual
13358 const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
13359 SS.MakeTrivial(S.Context,
13360 NestedNameSpecifier::Create(S.Context, nullptr, false,
13364 // Create the reference to operator=.
13365 ExprResult OpEqualRef
13366 = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false,
13367 SS, /*TemplateKWLoc=*/SourceLocation(),
13368 /*FirstQualifierInScope=*/nullptr,
13370 /*TemplateArgs=*/nullptr, /*S*/nullptr,
13371 /*SuppressQualifierCheck=*/true);
13372 if (OpEqualRef.isInvalid())
13373 return StmtError();
13375 // Build the call to the assignment operator.
13377 Expr *FromInst = From.build(S, Loc);
13378 ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr,
13379 OpEqualRef.getAs<Expr>(),
13380 Loc, FromInst, Loc);
13381 if (Call.isInvalid())
13382 return StmtError();
13384 // If we built a call to a trivial 'operator=' while copying an array,
13385 // bail out. We'll replace the whole shebang with a memcpy.
13386 CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get());
13387 if (CE && CE->getMethodDecl()->isTrivial() && Depth)
13388 return StmtResult((Stmt*)nullptr);
13390 // Convert to an expression-statement, and clean up any produced
13392 return S.ActOnExprStmt(Call);
13395 // - if the subobject is of scalar type, the built-in assignment
13396 // operator is used.
13397 const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
13399 ExprResult Assignment = S.CreateBuiltinBinOp(
13400 Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc));
13401 if (Assignment.isInvalid())
13402 return StmtError();
13403 return S.ActOnExprStmt(Assignment);
13406 // - if the subobject is an array, each element is assigned, in the
13407 // manner appropriate to the element type;
13409 // Construct a loop over the array bounds, e.g.,
13411 // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
13413 // that will copy each of the array elements.
13414 QualType SizeType = S.Context.getSizeType();
13416 // Create the iteration variable.
13417 IdentifierInfo *IterationVarName = nullptr;
13419 SmallString<8> Str;
13420 llvm::raw_svector_ostream OS(Str);
13421 OS << "__i" << Depth;
13422 IterationVarName = &S.Context.Idents.get(OS.str());
13424 VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
13425 IterationVarName, SizeType,
13426 S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
13429 // Initialize the iteration variable to zero.
13430 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
13431 IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
13433 // Creates a reference to the iteration variable.
13434 RefBuilder IterationVarRef(IterationVar, SizeType);
13435 LvalueConvBuilder IterationVarRefRVal(IterationVarRef);
13437 // Create the DeclStmt that holds the iteration variable.
13438 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
13440 // Subscript the "from" and "to" expressions with the iteration variable.
13441 SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal);
13442 MoveCastBuilder FromIndexMove(FromIndexCopy);
13443 const ExprBuilder *FromIndex;
13445 FromIndex = &FromIndexCopy;
13447 FromIndex = &FromIndexMove;
13449 SubscriptBuilder ToIndex(To, IterationVarRefRVal);
13451 // Build the copy/move for an individual element of the array.
13453 buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(),
13454 ToIndex, *FromIndex, CopyingBaseSubobject,
13455 Copying, Depth + 1);
13456 // Bail out if copying fails or if we determined that we should use memcpy.
13457 if (Copy.isInvalid() || !Copy.get())
13460 // Create the comparison against the array bound.
13462 = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
13464 = new (S.Context) BinaryOperator(IterationVarRefRVal.build(S, Loc),
13465 IntegerLiteral::Create(S.Context, Upper, SizeType, Loc),
13466 BO_NE, S.Context.BoolTy,
13467 VK_RValue, OK_Ordinary, Loc, FPOptions());
13469 // Create the pre-increment of the iteration variable. We can determine
13470 // whether the increment will overflow based on the value of the array
13472 Expr *Increment = new (S.Context)
13473 UnaryOperator(IterationVarRef.build(S, Loc), UO_PreInc, SizeType,
13474 VK_LValue, OK_Ordinary, Loc, Upper.isMaxValue());
13476 // Construct the loop that copies all elements of this array.
13477 return S.ActOnForStmt(
13478 Loc, Loc, InitStmt,
13479 S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean),
13480 S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get());
13484 buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
13485 const ExprBuilder &To, const ExprBuilder &From,
13486 bool CopyingBaseSubobject, bool Copying) {
13487 // Maybe we should use a memcpy?
13488 if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
13489 T.isTriviallyCopyableType(S.Context))
13490 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
13492 StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From,
13493 CopyingBaseSubobject,
13496 // If we ended up picking a trivial assignment operator for an array of a
13497 // non-trivially-copyable class type, just emit a memcpy.
13498 if (!Result.isInvalid() && !Result.get())
13499 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
13504 CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
13505 // Note: The following rules are largely analoguous to the copy
13506 // constructor rules. Note that virtual bases are not taken into account
13507 // for determining the argument type of the operator. Note also that
13508 // operators taking an object instead of a reference are allowed.
13509 assert(ClassDecl->needsImplicitCopyAssignment());
13511 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment);
13512 if (DSM.isAlreadyBeingDeclared())
13515 QualType ArgType = Context.getTypeDeclType(ClassDecl);
13516 LangAS AS = getDefaultCXXMethodAddrSpace();
13517 if (AS != LangAS::Default)
13518 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
13519 QualType RetType = Context.getLValueReferenceType(ArgType);
13520 bool Const = ClassDecl->implicitCopyAssignmentHasConstParam();
13522 ArgType = ArgType.withConst();
13524 ArgType = Context.getLValueReferenceType(ArgType);
13526 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13530 // An implicitly-declared copy assignment operator is an inline public
13531 // member of its class.
13532 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13533 SourceLocation ClassLoc = ClassDecl->getLocation();
13534 DeclarationNameInfo NameInfo(Name, ClassLoc);
13535 CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(
13536 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
13537 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
13538 /*isInline=*/true, Constexpr ? CSK_constexpr : CSK_unspecified,
13540 CopyAssignment->setAccess(AS_public);
13541 CopyAssignment->setDefaulted();
13542 CopyAssignment->setImplicit();
13544 if (getLangOpts().CUDA) {
13545 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment,
13547 /* ConstRHS */ Const,
13548 /* Diagnose */ false);
13551 setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType);
13553 // Add the parameter to the operator.
13554 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
13555 ClassLoc, ClassLoc,
13556 /*Id=*/nullptr, ArgType,
13557 /*TInfo=*/nullptr, SC_None,
13559 CopyAssignment->setParams(FromParam);
13561 CopyAssignment->setTrivial(
13562 ClassDecl->needsOverloadResolutionForCopyAssignment()
13563 ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment)
13564 : ClassDecl->hasTrivialCopyAssignment());
13566 // Note that we have added this copy-assignment operator.
13567 ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared;
13569 Scope *S = getScopeForContext(ClassDecl);
13570 CheckImplicitSpecialMemberDeclaration(S, CopyAssignment);
13572 if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment))
13573 SetDeclDeleted(CopyAssignment, ClassLoc);
13576 PushOnScopeChains(CopyAssignment, S, false);
13577 ClassDecl->addDecl(CopyAssignment);
13579 return CopyAssignment;
13582 /// Diagnose an implicit copy operation for a class which is odr-used, but
13583 /// which is deprecated because the class has a user-declared copy constructor,
13584 /// copy assignment operator, or destructor.
13585 static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) {
13586 assert(CopyOp->isImplicit());
13588 CXXRecordDecl *RD = CopyOp->getParent();
13589 CXXMethodDecl *UserDeclaredOperation = nullptr;
13591 // In Microsoft mode, assignment operations don't affect constructors and
13593 if (RD->hasUserDeclaredDestructor()) {
13594 UserDeclaredOperation = RD->getDestructor();
13595 } else if (!isa<CXXConstructorDecl>(CopyOp) &&
13596 RD->hasUserDeclaredCopyConstructor() &&
13597 !S.getLangOpts().MSVCCompat) {
13598 // Find any user-declared copy constructor.
13599 for (auto *I : RD->ctors()) {
13600 if (I->isCopyConstructor()) {
13601 UserDeclaredOperation = I;
13605 assert(UserDeclaredOperation);
13606 } else if (isa<CXXConstructorDecl>(CopyOp) &&
13607 RD->hasUserDeclaredCopyAssignment() &&
13608 !S.getLangOpts().MSVCCompat) {
13609 // Find any user-declared move assignment operator.
13610 for (auto *I : RD->methods()) {
13611 if (I->isCopyAssignmentOperator()) {
13612 UserDeclaredOperation = I;
13616 assert(UserDeclaredOperation);
13619 if (UserDeclaredOperation && UserDeclaredOperation->isUserProvided()) {
13620 S.Diag(UserDeclaredOperation->getLocation(),
13621 isa<CXXDestructorDecl>(UserDeclaredOperation)
13622 ? diag::warn_deprecated_copy_dtor_operation
13623 : diag::warn_deprecated_copy_operation)
13624 << RD << /*copy assignment*/ !isa<CXXConstructorDecl>(CopyOp);
13628 void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
13629 CXXMethodDecl *CopyAssignOperator) {
13630 assert((CopyAssignOperator->isDefaulted() &&
13631 CopyAssignOperator->isOverloadedOperator() &&
13632 CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
13633 !CopyAssignOperator->doesThisDeclarationHaveABody() &&
13634 !CopyAssignOperator->isDeleted()) &&
13635 "DefineImplicitCopyAssignment called for wrong function");
13636 if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl())
13639 CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
13640 if (ClassDecl->isInvalidDecl()) {
13641 CopyAssignOperator->setInvalidDecl();
13645 SynthesizedFunctionScope Scope(*this, CopyAssignOperator);
13647 // The exception specification is needed because we are defining the
13649 ResolveExceptionSpec(CurrentLocation,
13650 CopyAssignOperator->getType()->castAs<FunctionProtoType>());
13652 // Add a context note for diagnostics produced after this point.
13653 Scope.addContextNote(CurrentLocation);
13655 // C++11 [class.copy]p18:
13656 // The [definition of an implicitly declared copy assignment operator] is
13657 // deprecated if the class has a user-declared copy constructor or a
13658 // user-declared destructor.
13659 if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit())
13660 diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator);
13662 // C++0x [class.copy]p30:
13663 // The implicitly-defined or explicitly-defaulted copy assignment operator
13664 // for a non-union class X performs memberwise copy assignment of its
13665 // subobjects. The direct base classes of X are assigned first, in the
13666 // order of their declaration in the base-specifier-list, and then the
13667 // immediate non-static data members of X are assigned, in the order in
13668 // which they were declared in the class definition.
13670 // The statements that form the synthesized function body.
13671 SmallVector<Stmt*, 8> Statements;
13673 // The parameter for the "other" object, which we are copying from.
13674 ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
13675 Qualifiers OtherQuals = Other->getType().getQualifiers();
13676 QualType OtherRefType = Other->getType();
13677 if (const LValueReferenceType *OtherRef
13678 = OtherRefType->getAs<LValueReferenceType>()) {
13679 OtherRefType = OtherRef->getPointeeType();
13680 OtherQuals = OtherRefType.getQualifiers();
13683 // Our location for everything implicitly-generated.
13684 SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid()
13685 ? CopyAssignOperator->getEndLoc()
13686 : CopyAssignOperator->getLocation();
13688 // Builds a DeclRefExpr for the "other" object.
13689 RefBuilder OtherRef(Other, OtherRefType);
13691 // Builds the "this" pointer.
13694 // Assign base classes.
13695 bool Invalid = false;
13696 for (auto &Base : ClassDecl->bases()) {
13697 // Form the assignment:
13698 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
13699 QualType BaseType = Base.getType().getUnqualifiedType();
13700 if (!BaseType->isRecordType()) {
13705 CXXCastPath BasePath;
13706 BasePath.push_back(&Base);
13708 // Construct the "from" expression, which is an implicit cast to the
13709 // appropriately-qualified base type.
13710 CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals),
13711 VK_LValue, BasePath);
13713 // Dereference "this".
13714 DerefBuilder DerefThis(This);
13715 CastBuilder To(DerefThis,
13716 Context.getQualifiedType(
13717 BaseType, CopyAssignOperator->getMethodQualifiers()),
13718 VK_LValue, BasePath);
13721 StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType,
13723 /*CopyingBaseSubobject=*/true,
13725 if (Copy.isInvalid()) {
13726 CopyAssignOperator->setInvalidDecl();
13730 // Success! Record the copy.
13731 Statements.push_back(Copy.getAs<Expr>());
13734 // Assign non-static members.
13735 for (auto *Field : ClassDecl->fields()) {
13736 // FIXME: We should form some kind of AST representation for the implied
13737 // memcpy in a union copy operation.
13738 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
13741 if (Field->isInvalidDecl()) {
13746 // Check for members of reference type; we can't copy those.
13747 if (Field->getType()->isReferenceType()) {
13748 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
13749 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
13750 Diag(Field->getLocation(), diag::note_declared_at);
13755 // Check for members of const-qualified, non-class type.
13756 QualType BaseType = Context.getBaseElementType(Field->getType());
13757 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
13758 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
13759 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
13760 Diag(Field->getLocation(), diag::note_declared_at);
13765 // Suppress assigning zero-width bitfields.
13766 if (Field->isZeroLengthBitField(Context))
13769 QualType FieldType = Field->getType().getNonReferenceType();
13770 if (FieldType->isIncompleteArrayType()) {
13771 assert(ClassDecl->hasFlexibleArrayMember() &&
13772 "Incomplete array type is not valid");
13776 // Build references to the field in the object we're copying from and to.
13777 CXXScopeSpec SS; // Intentionally empty
13778 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
13780 MemberLookup.addDecl(Field);
13781 MemberLookup.resolveKind();
13783 MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup);
13785 MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup);
13787 // Build the copy of this field.
13788 StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType,
13790 /*CopyingBaseSubobject=*/false,
13792 if (Copy.isInvalid()) {
13793 CopyAssignOperator->setInvalidDecl();
13797 // Success! Record the copy.
13798 Statements.push_back(Copy.getAs<Stmt>());
13802 // Add a "return *this;"
13803 ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
13805 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
13806 if (Return.isInvalid())
13809 Statements.push_back(Return.getAs<Stmt>());
13813 CopyAssignOperator->setInvalidDecl();
13819 CompoundScopeRAII CompoundScope(*this);
13820 Body = ActOnCompoundStmt(Loc, Loc, Statements,
13821 /*isStmtExpr=*/false);
13822 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
13824 CopyAssignOperator->setBody(Body.getAs<Stmt>());
13825 CopyAssignOperator->markUsed(Context);
13827 if (ASTMutationListener *L = getASTMutationListener()) {
13828 L->CompletedImplicitDefinition(CopyAssignOperator);
13832 CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
13833 assert(ClassDecl->needsImplicitMoveAssignment());
13835 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment);
13836 if (DSM.isAlreadyBeingDeclared())
13839 // Note: The following rules are largely analoguous to the move
13840 // constructor rules.
13842 QualType ArgType = Context.getTypeDeclType(ClassDecl);
13843 LangAS AS = getDefaultCXXMethodAddrSpace();
13844 if (AS != LangAS::Default)
13845 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
13846 QualType RetType = Context.getLValueReferenceType(ArgType);
13847 ArgType = Context.getRValueReferenceType(ArgType);
13849 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
13853 // An implicitly-declared move assignment operator is an inline public
13854 // member of its class.
13855 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
13856 SourceLocation ClassLoc = ClassDecl->getLocation();
13857 DeclarationNameInfo NameInfo(Name, ClassLoc);
13858 CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(
13859 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
13860 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
13861 /*isInline=*/true, Constexpr ? CSK_constexpr : CSK_unspecified,
13863 MoveAssignment->setAccess(AS_public);
13864 MoveAssignment->setDefaulted();
13865 MoveAssignment->setImplicit();
13867 if (getLangOpts().CUDA) {
13868 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment,
13870 /* ConstRHS */ false,
13871 /* Diagnose */ false);
13874 // Build an exception specification pointing back at this member.
13875 FunctionProtoType::ExtProtoInfo EPI =
13876 getImplicitMethodEPI(*this, MoveAssignment);
13877 MoveAssignment->setType(Context.getFunctionType(RetType, ArgType, EPI));
13879 // Add the parameter to the operator.
13880 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
13881 ClassLoc, ClassLoc,
13882 /*Id=*/nullptr, ArgType,
13883 /*TInfo=*/nullptr, SC_None,
13885 MoveAssignment->setParams(FromParam);
13887 MoveAssignment->setTrivial(
13888 ClassDecl->needsOverloadResolutionForMoveAssignment()
13889 ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment)
13890 : ClassDecl->hasTrivialMoveAssignment());
13892 // Note that we have added this copy-assignment operator.
13893 ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared;
13895 Scope *S = getScopeForContext(ClassDecl);
13896 CheckImplicitSpecialMemberDeclaration(S, MoveAssignment);
13898 if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
13899 ClassDecl->setImplicitMoveAssignmentIsDeleted();
13900 SetDeclDeleted(MoveAssignment, ClassLoc);
13904 PushOnScopeChains(MoveAssignment, S, false);
13905 ClassDecl->addDecl(MoveAssignment);
13907 return MoveAssignment;
13910 /// Check if we're implicitly defining a move assignment operator for a class
13911 /// with virtual bases. Such a move assignment might move-assign the virtual
13912 /// base multiple times.
13913 static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class,
13914 SourceLocation CurrentLocation) {
13915 assert(!Class->isDependentContext() && "should not define dependent move");
13917 // Only a virtual base could get implicitly move-assigned multiple times.
13918 // Only a non-trivial move assignment can observe this. We only want to
13919 // diagnose if we implicitly define an assignment operator that assigns
13920 // two base classes, both of which move-assign the same virtual base.
13921 if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() ||
13922 Class->getNumBases() < 2)
13925 llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist;
13926 typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap;
13929 for (auto &BI : Class->bases()) {
13930 Worklist.push_back(&BI);
13931 while (!Worklist.empty()) {
13932 CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val();
13933 CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl();
13935 // If the base has no non-trivial move assignment operators,
13936 // we don't care about moves from it.
13937 if (!Base->hasNonTrivialMoveAssignment())
13940 // If there's nothing virtual here, skip it.
13941 if (!BaseSpec->isVirtual() && !Base->getNumVBases())
13944 // If we're not actually going to call a move assignment for this base,
13945 // or the selected move assignment is trivial, skip it.
13946 Sema::SpecialMemberOverloadResult SMOR =
13947 S.LookupSpecialMember(Base, Sema::CXXMoveAssignment,
13948 /*ConstArg*/false, /*VolatileArg*/false,
13949 /*RValueThis*/true, /*ConstThis*/false,
13950 /*VolatileThis*/false);
13951 if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() ||
13952 !SMOR.getMethod()->isMoveAssignmentOperator())
13955 if (BaseSpec->isVirtual()) {
13956 // We're going to move-assign this virtual base, and its move
13957 // assignment operator is not trivial. If this can happen for
13958 // multiple distinct direct bases of Class, diagnose it. (If it
13959 // only happens in one base, we'll diagnose it when synthesizing
13960 // that base class's move assignment operator.)
13961 CXXBaseSpecifier *&Existing =
13962 VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI))
13964 if (Existing && Existing != &BI) {
13965 S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times)
13967 S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here)
13968 << (Base->getCanonicalDecl() ==
13969 Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl())
13970 << Base << Existing->getType() << Existing->getSourceRange();
13971 S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here)
13972 << (Base->getCanonicalDecl() ==
13973 BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl())
13974 << Base << BI.getType() << BaseSpec->getSourceRange();
13976 // Only diagnose each vbase once.
13977 Existing = nullptr;
13980 // Only walk over bases that have defaulted move assignment operators.
13981 // We assume that any user-provided move assignment operator handles
13982 // the multiple-moves-of-vbase case itself somehow.
13983 if (!SMOR.getMethod()->isDefaulted())
13986 // We're going to move the base classes of Base. Add them to the list.
13987 for (auto &BI : Base->bases())
13988 Worklist.push_back(&BI);
13994 void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
13995 CXXMethodDecl *MoveAssignOperator) {
13996 assert((MoveAssignOperator->isDefaulted() &&
13997 MoveAssignOperator->isOverloadedOperator() &&
13998 MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
13999 !MoveAssignOperator->doesThisDeclarationHaveABody() &&
14000 !MoveAssignOperator->isDeleted()) &&
14001 "DefineImplicitMoveAssignment called for wrong function");
14002 if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl())
14005 CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
14006 if (ClassDecl->isInvalidDecl()) {
14007 MoveAssignOperator->setInvalidDecl();
14011 // C++0x [class.copy]p28:
14012 // The implicitly-defined or move assignment operator for a non-union class
14013 // X performs memberwise move assignment of its subobjects. The direct base
14014 // classes of X are assigned first, in the order of their declaration in the
14015 // base-specifier-list, and then the immediate non-static data members of X
14016 // are assigned, in the order in which they were declared in the class
14019 // Issue a warning if our implicit move assignment operator will move
14020 // from a virtual base more than once.
14021 checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation);
14023 SynthesizedFunctionScope Scope(*this, MoveAssignOperator);
14025 // The exception specification is needed because we are defining the
14027 ResolveExceptionSpec(CurrentLocation,
14028 MoveAssignOperator->getType()->castAs<FunctionProtoType>());
14030 // Add a context note for diagnostics produced after this point.
14031 Scope.addContextNote(CurrentLocation);
14033 // The statements that form the synthesized function body.
14034 SmallVector<Stmt*, 8> Statements;
14036 // The parameter for the "other" object, which we are move from.
14037 ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
14038 QualType OtherRefType =
14039 Other->getType()->castAs<RValueReferenceType>()->getPointeeType();
14041 // Our location for everything implicitly-generated.
14042 SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid()
14043 ? MoveAssignOperator->getEndLoc()
14044 : MoveAssignOperator->getLocation();
14046 // Builds a reference to the "other" object.
14047 RefBuilder OtherRef(Other, OtherRefType);
14049 MoveCastBuilder MoveOther(OtherRef);
14051 // Builds the "this" pointer.
14054 // Assign base classes.
14055 bool Invalid = false;
14056 for (auto &Base : ClassDecl->bases()) {
14057 // C++11 [class.copy]p28:
14058 // It is unspecified whether subobjects representing virtual base classes
14059 // are assigned more than once by the implicitly-defined copy assignment
14061 // FIXME: Do not assign to a vbase that will be assigned by some other base
14062 // class. For a move-assignment, this can result in the vbase being moved
14065 // Form the assignment:
14066 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
14067 QualType BaseType = Base.getType().getUnqualifiedType();
14068 if (!BaseType->isRecordType()) {
14073 CXXCastPath BasePath;
14074 BasePath.push_back(&Base);
14076 // Construct the "from" expression, which is an implicit cast to the
14077 // appropriately-qualified base type.
14078 CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath);
14080 // Dereference "this".
14081 DerefBuilder DerefThis(This);
14083 // Implicitly cast "this" to the appropriately-qualified base type.
14084 CastBuilder To(DerefThis,
14085 Context.getQualifiedType(
14086 BaseType, MoveAssignOperator->getMethodQualifiers()),
14087 VK_LValue, BasePath);
14090 StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType,
14092 /*CopyingBaseSubobject=*/true,
14093 /*Copying=*/false);
14094 if (Move.isInvalid()) {
14095 MoveAssignOperator->setInvalidDecl();
14099 // Success! Record the move.
14100 Statements.push_back(Move.getAs<Expr>());
14103 // Assign non-static members.
14104 for (auto *Field : ClassDecl->fields()) {
14105 // FIXME: We should form some kind of AST representation for the implied
14106 // memcpy in a union copy operation.
14107 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
14110 if (Field->isInvalidDecl()) {
14115 // Check for members of reference type; we can't move those.
14116 if (Field->getType()->isReferenceType()) {
14117 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14118 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
14119 Diag(Field->getLocation(), diag::note_declared_at);
14124 // Check for members of const-qualified, non-class type.
14125 QualType BaseType = Context.getBaseElementType(Field->getType());
14126 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
14127 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
14128 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
14129 Diag(Field->getLocation(), diag::note_declared_at);
14134 // Suppress assigning zero-width bitfields.
14135 if (Field->isZeroLengthBitField(Context))
14138 QualType FieldType = Field->getType().getNonReferenceType();
14139 if (FieldType->isIncompleteArrayType()) {
14140 assert(ClassDecl->hasFlexibleArrayMember() &&
14141 "Incomplete array type is not valid");
14145 // Build references to the field in the object we're copying from and to.
14146 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
14148 MemberLookup.addDecl(Field);
14149 MemberLookup.resolveKind();
14150 MemberBuilder From(MoveOther, OtherRefType,
14151 /*IsArrow=*/false, MemberLookup);
14152 MemberBuilder To(This, getCurrentThisType(),
14153 /*IsArrow=*/true, MemberLookup);
14155 assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue
14156 "Member reference with rvalue base must be rvalue except for reference "
14157 "members, which aren't allowed for move assignment.");
14159 // Build the move of this field.
14160 StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType,
14162 /*CopyingBaseSubobject=*/false,
14163 /*Copying=*/false);
14164 if (Move.isInvalid()) {
14165 MoveAssignOperator->setInvalidDecl();
14169 // Success! Record the copy.
14170 Statements.push_back(Move.getAs<Stmt>());
14174 // Add a "return *this;"
14175 ExprResult ThisObj =
14176 CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
14178 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
14179 if (Return.isInvalid())
14182 Statements.push_back(Return.getAs<Stmt>());
14186 MoveAssignOperator->setInvalidDecl();
14192 CompoundScopeRAII CompoundScope(*this);
14193 Body = ActOnCompoundStmt(Loc, Loc, Statements,
14194 /*isStmtExpr=*/false);
14195 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
14197 MoveAssignOperator->setBody(Body.getAs<Stmt>());
14198 MoveAssignOperator->markUsed(Context);
14200 if (ASTMutationListener *L = getASTMutationListener()) {
14201 L->CompletedImplicitDefinition(MoveAssignOperator);
14205 CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
14206 CXXRecordDecl *ClassDecl) {
14207 // C++ [class.copy]p4:
14208 // If the class definition does not explicitly declare a copy
14209 // constructor, one is declared implicitly.
14210 assert(ClassDecl->needsImplicitCopyConstructor());
14212 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor);
14213 if (DSM.isAlreadyBeingDeclared())
14216 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14217 QualType ArgType = ClassType;
14218 bool Const = ClassDecl->implicitCopyConstructorHasConstParam();
14220 ArgType = ArgType.withConst();
14222 LangAS AS = getDefaultCXXMethodAddrSpace();
14223 if (AS != LangAS::Default)
14224 ArgType = Context.getAddrSpaceQualType(ArgType, AS);
14226 ArgType = Context.getLValueReferenceType(ArgType);
14228 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14229 CXXCopyConstructor,
14232 DeclarationName Name
14233 = Context.DeclarationNames.getCXXConstructorName(
14234 Context.getCanonicalType(ClassType));
14235 SourceLocation ClassLoc = ClassDecl->getLocation();
14236 DeclarationNameInfo NameInfo(Name, ClassLoc);
14238 // An implicitly-declared copy constructor is an inline public
14239 // member of its class.
14240 CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
14241 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
14242 ExplicitSpecifier(),
14244 /*isImplicitlyDeclared=*/true,
14245 Constexpr ? CSK_constexpr : CSK_unspecified);
14246 CopyConstructor->setAccess(AS_public);
14247 CopyConstructor->setDefaulted();
14249 if (getLangOpts().CUDA) {
14250 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor,
14252 /* ConstRHS */ Const,
14253 /* Diagnose */ false);
14256 setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType);
14258 // Add the parameter to the constructor.
14259 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
14260 ClassLoc, ClassLoc,
14261 /*IdentifierInfo=*/nullptr,
14262 ArgType, /*TInfo=*/nullptr,
14264 CopyConstructor->setParams(FromParam);
14266 CopyConstructor->setTrivial(
14267 ClassDecl->needsOverloadResolutionForCopyConstructor()
14268 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor)
14269 : ClassDecl->hasTrivialCopyConstructor());
14271 CopyConstructor->setTrivialForCall(
14272 ClassDecl->hasAttr<TrivialABIAttr>() ||
14273 (ClassDecl->needsOverloadResolutionForCopyConstructor()
14274 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor,
14275 TAH_ConsiderTrivialABI)
14276 : ClassDecl->hasTrivialCopyConstructorForCall()));
14278 // Note that we have declared this constructor.
14279 ++getASTContext().NumImplicitCopyConstructorsDeclared;
14281 Scope *S = getScopeForContext(ClassDecl);
14282 CheckImplicitSpecialMemberDeclaration(S, CopyConstructor);
14284 if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) {
14285 ClassDecl->setImplicitCopyConstructorIsDeleted();
14286 SetDeclDeleted(CopyConstructor, ClassLoc);
14290 PushOnScopeChains(CopyConstructor, S, false);
14291 ClassDecl->addDecl(CopyConstructor);
14293 return CopyConstructor;
14296 void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
14297 CXXConstructorDecl *CopyConstructor) {
14298 assert((CopyConstructor->isDefaulted() &&
14299 CopyConstructor->isCopyConstructor() &&
14300 !CopyConstructor->doesThisDeclarationHaveABody() &&
14301 !CopyConstructor->isDeleted()) &&
14302 "DefineImplicitCopyConstructor - call it for implicit copy ctor");
14303 if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl())
14306 CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
14307 assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
14309 SynthesizedFunctionScope Scope(*this, CopyConstructor);
14311 // The exception specification is needed because we are defining the
14313 ResolveExceptionSpec(CurrentLocation,
14314 CopyConstructor->getType()->castAs<FunctionProtoType>());
14315 MarkVTableUsed(CurrentLocation, ClassDecl);
14317 // Add a context note for diagnostics produced after this point.
14318 Scope.addContextNote(CurrentLocation);
14320 // C++11 [class.copy]p7:
14321 // The [definition of an implicitly declared copy constructor] is
14322 // deprecated if the class has a user-declared copy assignment operator
14323 // or a user-declared destructor.
14324 if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit())
14325 diagnoseDeprecatedCopyOperation(*this, CopyConstructor);
14327 if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) {
14328 CopyConstructor->setInvalidDecl();
14330 SourceLocation Loc = CopyConstructor->getEndLoc().isValid()
14331 ? CopyConstructor->getEndLoc()
14332 : CopyConstructor->getLocation();
14333 Sema::CompoundScopeRAII CompoundScope(*this);
14334 CopyConstructor->setBody(
14335 ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>());
14336 CopyConstructor->markUsed(Context);
14339 if (ASTMutationListener *L = getASTMutationListener()) {
14340 L->CompletedImplicitDefinition(CopyConstructor);
14344 CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
14345 CXXRecordDecl *ClassDecl) {
14346 assert(ClassDecl->needsImplicitMoveConstructor());
14348 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor);
14349 if (DSM.isAlreadyBeingDeclared())
14352 QualType ClassType = Context.getTypeDeclType(ClassDecl);
14354 QualType ArgType = ClassType;
14355 LangAS AS = getDefaultCXXMethodAddrSpace();
14356 if (AS != LangAS::Default)
14357 ArgType = Context.getAddrSpaceQualType(ClassType, AS);
14358 ArgType = Context.getRValueReferenceType(ArgType);
14360 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
14361 CXXMoveConstructor,
14364 DeclarationName Name
14365 = Context.DeclarationNames.getCXXConstructorName(
14366 Context.getCanonicalType(ClassType));
14367 SourceLocation ClassLoc = ClassDecl->getLocation();
14368 DeclarationNameInfo NameInfo(Name, ClassLoc);
14370 // C++11 [class.copy]p11:
14371 // An implicitly-declared copy/move constructor is an inline public
14372 // member of its class.
14373 CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
14374 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
14375 ExplicitSpecifier(),
14377 /*isImplicitlyDeclared=*/true,
14378 Constexpr ? CSK_constexpr : CSK_unspecified);
14379 MoveConstructor->setAccess(AS_public);
14380 MoveConstructor->setDefaulted();
14382 if (getLangOpts().CUDA) {
14383 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor,
14385 /* ConstRHS */ false,
14386 /* Diagnose */ false);
14389 setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType);
14391 // Add the parameter to the constructor.
14392 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
14393 ClassLoc, ClassLoc,
14394 /*IdentifierInfo=*/nullptr,
14395 ArgType, /*TInfo=*/nullptr,
14397 MoveConstructor->setParams(FromParam);
14399 MoveConstructor->setTrivial(
14400 ClassDecl->needsOverloadResolutionForMoveConstructor()
14401 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor)
14402 : ClassDecl->hasTrivialMoveConstructor());
14404 MoveConstructor->setTrivialForCall(
14405 ClassDecl->hasAttr<TrivialABIAttr>() ||
14406 (ClassDecl->needsOverloadResolutionForMoveConstructor()
14407 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor,
14408 TAH_ConsiderTrivialABI)
14409 : ClassDecl->hasTrivialMoveConstructorForCall()));
14411 // Note that we have declared this constructor.
14412 ++getASTContext().NumImplicitMoveConstructorsDeclared;
14414 Scope *S = getScopeForContext(ClassDecl);
14415 CheckImplicitSpecialMemberDeclaration(S, MoveConstructor);
14417 if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
14418 ClassDecl->setImplicitMoveConstructorIsDeleted();
14419 SetDeclDeleted(MoveConstructor, ClassLoc);
14423 PushOnScopeChains(MoveConstructor, S, false);
14424 ClassDecl->addDecl(MoveConstructor);
14426 return MoveConstructor;
14429 void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
14430 CXXConstructorDecl *MoveConstructor) {
14431 assert((MoveConstructor->isDefaulted() &&
14432 MoveConstructor->isMoveConstructor() &&
14433 !MoveConstructor->doesThisDeclarationHaveABody() &&
14434 !MoveConstructor->isDeleted()) &&
14435 "DefineImplicitMoveConstructor - call it for implicit move ctor");
14436 if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl())
14439 CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
14440 assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
14442 SynthesizedFunctionScope Scope(*this, MoveConstructor);
14444 // The exception specification is needed because we are defining the
14446 ResolveExceptionSpec(CurrentLocation,
14447 MoveConstructor->getType()->castAs<FunctionProtoType>());
14448 MarkVTableUsed(CurrentLocation, ClassDecl);
14450 // Add a context note for diagnostics produced after this point.
14451 Scope.addContextNote(CurrentLocation);
14453 if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) {
14454 MoveConstructor->setInvalidDecl();
14456 SourceLocation Loc = MoveConstructor->getEndLoc().isValid()
14457 ? MoveConstructor->getEndLoc()
14458 : MoveConstructor->getLocation();
14459 Sema::CompoundScopeRAII CompoundScope(*this);
14460 MoveConstructor->setBody(ActOnCompoundStmt(
14461 Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>());
14462 MoveConstructor->markUsed(Context);
14465 if (ASTMutationListener *L = getASTMutationListener()) {
14466 L->CompletedImplicitDefinition(MoveConstructor);
14470 bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
14471 return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD);
14474 void Sema::DefineImplicitLambdaToFunctionPointerConversion(
14475 SourceLocation CurrentLocation,
14476 CXXConversionDecl *Conv) {
14477 SynthesizedFunctionScope Scope(*this, Conv);
14478 assert(!Conv->getReturnType()->isUndeducedType());
14480 CXXRecordDecl *Lambda = Conv->getParent();
14481 FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
14482 FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker();
14484 if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) {
14485 CallOp = InstantiateFunctionDeclaration(
14486 CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
14490 Invoker = InstantiateFunctionDeclaration(
14491 Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
14496 if (CallOp->isInvalidDecl())
14499 // Mark the call operator referenced (and add to pending instantiations
14501 // For both the conversion and static-invoker template specializations
14502 // we construct their body's in this function, so no need to add them
14503 // to the PendingInstantiations.
14504 MarkFunctionReferenced(CurrentLocation, CallOp);
14506 // Fill in the __invoke function with a dummy implementation. IR generation
14507 // will fill in the actual details. Update its type in case it contained
14509 Invoker->markUsed(Context);
14510 Invoker->setReferenced();
14511 Invoker->setType(Conv->getReturnType()->getPointeeType());
14512 Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation()));
14514 // Construct the body of the conversion function { return __invoke; }.
14515 Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(),
14516 VK_LValue, Conv->getLocation());
14517 assert(FunctionRef && "Can't refer to __invoke function?");
14518 Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get();
14519 Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(),
14520 Conv->getLocation()));
14521 Conv->markUsed(Context);
14522 Conv->setReferenced();
14524 if (ASTMutationListener *L = getASTMutationListener()) {
14525 L->CompletedImplicitDefinition(Conv);
14526 L->CompletedImplicitDefinition(Invoker);
14532 void Sema::DefineImplicitLambdaToBlockPointerConversion(
14533 SourceLocation CurrentLocation,
14534 CXXConversionDecl *Conv)
14536 assert(!Conv->getParent()->isGenericLambda());
14538 SynthesizedFunctionScope Scope(*this, Conv);
14540 // Copy-initialize the lambda object as needed to capture it.
14541 Expr *This = ActOnCXXThis(CurrentLocation).get();
14542 Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get();
14544 ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
14545 Conv->getLocation(),
14548 // If we're not under ARC, make sure we still get the _Block_copy/autorelease
14549 // behavior. Note that only the general conversion function does this
14550 // (since it's unusable otherwise); in the case where we inline the
14551 // block literal, it has block literal lifetime semantics.
14552 if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
14553 BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(),
14554 CK_CopyAndAutoreleaseBlockObject,
14555 BuildBlock.get(), nullptr, VK_RValue);
14557 if (BuildBlock.isInvalid()) {
14558 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
14559 Conv->setInvalidDecl();
14563 // Create the return statement that returns the block from the conversion
14565 StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get());
14566 if (Return.isInvalid()) {
14567 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
14568 Conv->setInvalidDecl();
14572 // Set the body of the conversion function.
14573 Stmt *ReturnS = Return.get();
14574 Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(),
14575 Conv->getLocation()));
14576 Conv->markUsed(Context);
14578 // We're done; notify the mutation listener, if any.
14579 if (ASTMutationListener *L = getASTMutationListener()) {
14580 L->CompletedImplicitDefinition(Conv);
14584 /// Determine whether the given list arguments contains exactly one
14585 /// "real" (non-default) argument.
14586 static bool hasOneRealArgument(MultiExprArg Args) {
14587 switch (Args.size()) {
14592 if (!Args[1]->isDefaultArgument())
14597 return !Args[0]->isDefaultArgument();
14604 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
14605 NamedDecl *FoundDecl,
14606 CXXConstructorDecl *Constructor,
14607 MultiExprArg ExprArgs,
14608 bool HadMultipleCandidates,
14609 bool IsListInitialization,
14610 bool IsStdInitListInitialization,
14611 bool RequiresZeroInit,
14612 unsigned ConstructKind,
14613 SourceRange ParenRange) {
14614 bool Elidable = false;
14616 // C++0x [class.copy]p34:
14617 // When certain criteria are met, an implementation is allowed to
14618 // omit the copy/move construction of a class object, even if the
14619 // copy/move constructor and/or destructor for the object have
14620 // side effects. [...]
14621 // - when a temporary class object that has not been bound to a
14622 // reference (12.2) would be copied/moved to a class object
14623 // with the same cv-unqualified type, the copy/move operation
14624 // can be omitted by constructing the temporary object
14625 // directly into the target of the omitted copy/move
14626 if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor &&
14627 Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
14628 Expr *SubExpr = ExprArgs[0];
14629 Elidable = SubExpr->isTemporaryObject(
14630 Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext()));
14633 return BuildCXXConstructExpr(ConstructLoc, DeclInitType,
14634 FoundDecl, Constructor,
14635 Elidable, ExprArgs, HadMultipleCandidates,
14636 IsListInitialization,
14637 IsStdInitListInitialization, RequiresZeroInit,
14638 ConstructKind, ParenRange);
14642 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
14643 NamedDecl *FoundDecl,
14644 CXXConstructorDecl *Constructor,
14646 MultiExprArg ExprArgs,
14647 bool HadMultipleCandidates,
14648 bool IsListInitialization,
14649 bool IsStdInitListInitialization,
14650 bool RequiresZeroInit,
14651 unsigned ConstructKind,
14652 SourceRange ParenRange) {
14653 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) {
14654 Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow);
14655 if (DiagnoseUseOfDecl(Constructor, ConstructLoc))
14656 return ExprError();
14659 return BuildCXXConstructExpr(
14660 ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs,
14661 HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization,
14662 RequiresZeroInit, ConstructKind, ParenRange);
14665 /// BuildCXXConstructExpr - Creates a complete call to a constructor,
14666 /// including handling of its default argument expressions.
14668 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
14669 CXXConstructorDecl *Constructor,
14671 MultiExprArg ExprArgs,
14672 bool HadMultipleCandidates,
14673 bool IsListInitialization,
14674 bool IsStdInitListInitialization,
14675 bool RequiresZeroInit,
14676 unsigned ConstructKind,
14677 SourceRange ParenRange) {
14678 assert(declaresSameEntity(
14679 Constructor->getParent(),
14680 DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&
14681 "given constructor for wrong type");
14682 MarkFunctionReferenced(ConstructLoc, Constructor);
14683 if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor))
14684 return ExprError();
14686 return CXXConstructExpr::Create(
14687 Context, DeclInitType, ConstructLoc, Constructor, Elidable,
14688 ExprArgs, HadMultipleCandidates, IsListInitialization,
14689 IsStdInitListInitialization, RequiresZeroInit,
14690 static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
14694 ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
14695 assert(Field->hasInClassInitializer());
14697 // If we already have the in-class initializer nothing needs to be done.
14698 if (Field->getInClassInitializer())
14699 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
14701 // If we might have already tried and failed to instantiate, don't try again.
14702 if (Field->isInvalidDecl())
14703 return ExprError();
14705 // Maybe we haven't instantiated the in-class initializer. Go check the
14706 // pattern FieldDecl to see if it has one.
14707 CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent());
14709 if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {
14710 CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern();
14711 DeclContext::lookup_result Lookup =
14712 ClassPattern->lookup(Field->getDeclName());
14714 // Lookup can return at most two results: the pattern for the field, or the
14715 // injected class name of the parent record. No other member can have the
14716 // same name as the field.
14717 // In modules mode, lookup can return multiple results (coming from
14718 // different modules).
14719 assert((getLangOpts().Modules || (!Lookup.empty() && Lookup.size() <= 2)) &&
14720 "more than two lookup results for field name");
14721 FieldDecl *Pattern = dyn_cast<FieldDecl>(Lookup[0]);
14723 assert(isa<CXXRecordDecl>(Lookup[0]) &&
14724 "cannot have other non-field member with same name");
14725 for (auto L : Lookup)
14726 if (isa<FieldDecl>(L)) {
14727 Pattern = cast<FieldDecl>(L);
14730 assert(Pattern && "We must have set the Pattern!");
14733 if (!Pattern->hasInClassInitializer() ||
14734 InstantiateInClassInitializer(Loc, Field, Pattern,
14735 getTemplateInstantiationArgs(Field))) {
14736 // Don't diagnose this again.
14737 Field->setInvalidDecl();
14738 return ExprError();
14740 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
14744 // If the brace-or-equal-initializer of a non-static data member
14745 // invokes a defaulted default constructor of its class or of an
14746 // enclosing class in a potentially evaluated subexpression, the
14747 // program is ill-formed.
14749 // This resolution is unworkable: the exception specification of the
14750 // default constructor can be needed in an unevaluated context, in
14751 // particular, in the operand of a noexcept-expression, and we can be
14752 // unable to compute an exception specification for an enclosed class.
14754 // Any attempt to resolve the exception specification of a defaulted default
14755 // constructor before the initializer is lexically complete will ultimately
14756 // come here at which point we can diagnose it.
14757 RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext();
14758 Diag(Loc, diag::err_in_class_initializer_not_yet_parsed)
14759 << OutermostClass << Field;
14760 Diag(Field->getEndLoc(), diag::note_in_class_initializer_not_yet_parsed);
14761 // Recover by marking the field invalid, unless we're in a SFINAE context.
14762 if (!isSFINAEContext())
14763 Field->setInvalidDecl();
14764 return ExprError();
14767 void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
14768 if (VD->isInvalidDecl()) return;
14770 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
14771 if (ClassDecl->isInvalidDecl()) return;
14772 if (ClassDecl->hasIrrelevantDestructor()) return;
14773 if (ClassDecl->isDependentContext()) return;
14775 if (VD->isNoDestroy(getASTContext()))
14778 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
14780 // If this is an array, we'll require the destructor during initialization, so
14781 // we can skip over this. We still want to emit exit-time destructor warnings
14783 if (!VD->getType()->isArrayType()) {
14784 MarkFunctionReferenced(VD->getLocation(), Destructor);
14785 CheckDestructorAccess(VD->getLocation(), Destructor,
14786 PDiag(diag::err_access_dtor_var)
14787 << VD->getDeclName() << VD->getType());
14788 DiagnoseUseOfDecl(Destructor, VD->getLocation());
14791 if (Destructor->isTrivial()) return;
14793 // If the destructor is constexpr, check whether the variable has constant
14794 // destruction now.
14795 if (Destructor->isConstexpr() && VD->getInit() &&
14796 !VD->getInit()->isValueDependent() && VD->evaluateValue()) {
14797 SmallVector<PartialDiagnosticAt, 8> Notes;
14798 if (!VD->evaluateDestruction(Notes) && VD->isConstexpr()) {
14799 Diag(VD->getLocation(),
14800 diag::err_constexpr_var_requires_const_destruction) << VD;
14801 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
14802 Diag(Notes[I].first, Notes[I].second);
14806 if (!VD->hasGlobalStorage()) return;
14808 // Emit warning for non-trivial dtor in global scope (a real global,
14809 // class-static, function-static).
14810 Diag(VD->getLocation(), diag::warn_exit_time_destructor);
14812 // TODO: this should be re-enabled for static locals by !CXAAtExit
14813 if (!VD->isStaticLocal())
14814 Diag(VD->getLocation(), diag::warn_global_destructor);
14817 /// Given a constructor and the set of arguments provided for the
14818 /// constructor, convert the arguments and add any required default arguments
14819 /// to form a proper call to this constructor.
14821 /// \returns true if an error occurred, false otherwise.
14823 Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
14824 MultiExprArg ArgsPtr,
14825 SourceLocation Loc,
14826 SmallVectorImpl<Expr*> &ConvertedArgs,
14827 bool AllowExplicit,
14828 bool IsListInitialization) {
14829 // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
14830 unsigned NumArgs = ArgsPtr.size();
14831 Expr **Args = ArgsPtr.data();
14833 const auto *Proto = Constructor->getType()->castAs<FunctionProtoType>();
14834 unsigned NumParams = Proto->getNumParams();
14836 // If too few arguments are available, we'll fill in the rest with defaults.
14837 if (NumArgs < NumParams)
14838 ConvertedArgs.reserve(NumParams);
14840 ConvertedArgs.reserve(NumArgs);
14842 VariadicCallType CallType =
14843 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
14844 SmallVector<Expr *, 8> AllArgs;
14845 bool Invalid = GatherArgumentsForCall(Loc, Constructor,
14847 llvm::makeArrayRef(Args, NumArgs),
14849 CallType, AllowExplicit,
14850 IsListInitialization);
14851 ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
14853 DiagnoseSentinelCalls(Constructor, Loc, AllArgs);
14855 CheckConstructorCall(Constructor,
14856 llvm::makeArrayRef(AllArgs.data(), AllArgs.size()),
14863 CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
14864 const FunctionDecl *FnDecl) {
14865 const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
14866 if (isa<NamespaceDecl>(DC)) {
14867 return SemaRef.Diag(FnDecl->getLocation(),
14868 diag::err_operator_new_delete_declared_in_namespace)
14869 << FnDecl->getDeclName();
14872 if (isa<TranslationUnitDecl>(DC) &&
14873 FnDecl->getStorageClass() == SC_Static) {
14874 return SemaRef.Diag(FnDecl->getLocation(),
14875 diag::err_operator_new_delete_declared_static)
14876 << FnDecl->getDeclName();
14883 RemoveAddressSpaceFromPtr(Sema &SemaRef, const PointerType *PtrTy) {
14884 QualType QTy = PtrTy->getPointeeType();
14885 QTy = SemaRef.Context.removeAddrSpaceQualType(QTy);
14886 return SemaRef.Context.getPointerType(QTy);
14890 CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
14891 CanQualType ExpectedResultType,
14892 CanQualType ExpectedFirstParamType,
14893 unsigned DependentParamTypeDiag,
14894 unsigned InvalidParamTypeDiag) {
14895 QualType ResultType =
14896 FnDecl->getType()->castAs<FunctionType>()->getReturnType();
14898 // Check that the result type is not dependent.
14899 if (ResultType->isDependentType())
14900 return SemaRef.Diag(FnDecl->getLocation(),
14901 diag::err_operator_new_delete_dependent_result_type)
14902 << FnDecl->getDeclName() << ExpectedResultType;
14904 // The operator is valid on any address space for OpenCL.
14905 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
14906 if (auto *PtrTy = ResultType->getAs<PointerType>()) {
14907 ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
14911 // Check that the result type is what we expect.
14912 if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
14913 return SemaRef.Diag(FnDecl->getLocation(),
14914 diag::err_operator_new_delete_invalid_result_type)
14915 << FnDecl->getDeclName() << ExpectedResultType;
14917 // A function template must have at least 2 parameters.
14918 if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
14919 return SemaRef.Diag(FnDecl->getLocation(),
14920 diag::err_operator_new_delete_template_too_few_parameters)
14921 << FnDecl->getDeclName();
14923 // The function decl must have at least 1 parameter.
14924 if (FnDecl->getNumParams() == 0)
14925 return SemaRef.Diag(FnDecl->getLocation(),
14926 diag::err_operator_new_delete_too_few_parameters)
14927 << FnDecl->getDeclName();
14929 // Check the first parameter type is not dependent.
14930 QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
14931 if (FirstParamType->isDependentType())
14932 return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
14933 << FnDecl->getDeclName() << ExpectedFirstParamType;
14935 // Check that the first parameter type is what we expect.
14936 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
14937 // The operator is valid on any address space for OpenCL.
14939 FnDecl->getParamDecl(0)->getType()->getAs<PointerType>()) {
14940 FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
14943 if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
14944 ExpectedFirstParamType)
14945 return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
14946 << FnDecl->getDeclName() << ExpectedFirstParamType;
14952 CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
14953 // C++ [basic.stc.dynamic.allocation]p1:
14954 // A program is ill-formed if an allocation function is declared in a
14955 // namespace scope other than global scope or declared static in global
14957 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
14960 CanQualType SizeTy =
14961 SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
14963 // C++ [basic.stc.dynamic.allocation]p1:
14964 // The return type shall be void*. The first parameter shall have type
14966 if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
14968 diag::err_operator_new_dependent_param_type,
14969 diag::err_operator_new_param_type))
14972 // C++ [basic.stc.dynamic.allocation]p1:
14973 // The first parameter shall not have an associated default argument.
14974 if (FnDecl->getParamDecl(0)->hasDefaultArg())
14975 return SemaRef.Diag(FnDecl->getLocation(),
14976 diag::err_operator_new_default_arg)
14977 << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
14983 CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) {
14984 // C++ [basic.stc.dynamic.deallocation]p1:
14985 // A program is ill-formed if deallocation functions are declared in a
14986 // namespace scope other than global scope or declared static in global
14988 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
14991 auto *MD = dyn_cast<CXXMethodDecl>(FnDecl);
14994 // Within a class C, the first parameter of a destroying operator delete
14995 // shall be of type C *. The first parameter of any other deallocation
14996 // function shall be of type void *.
14997 CanQualType ExpectedFirstParamType =
14998 MD && MD->isDestroyingOperatorDelete()
14999 ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType(
15000 SemaRef.Context.getRecordType(MD->getParent())))
15001 : SemaRef.Context.VoidPtrTy;
15003 // C++ [basic.stc.dynamic.deallocation]p2:
15004 // Each deallocation function shall return void
15005 if (CheckOperatorNewDeleteTypes(
15006 SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType,
15007 diag::err_operator_delete_dependent_param_type,
15008 diag::err_operator_delete_param_type))
15012 // A destroying operator delete shall be a usual deallocation function.
15013 if (MD && !MD->getParent()->isDependentContext() &&
15014 MD->isDestroyingOperatorDelete() &&
15015 !SemaRef.isUsualDeallocationFunction(MD)) {
15016 SemaRef.Diag(MD->getLocation(),
15017 diag::err_destroying_operator_delete_not_usual);
15024 /// CheckOverloadedOperatorDeclaration - Check whether the declaration
15025 /// of this overloaded operator is well-formed. If so, returns false;
15026 /// otherwise, emits appropriate diagnostics and returns true.
15027 bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
15028 assert(FnDecl && FnDecl->isOverloadedOperator() &&
15029 "Expected an overloaded operator declaration");
15031 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
15033 // C++ [over.oper]p5:
15034 // The allocation and deallocation functions, operator new,
15035 // operator new[], operator delete and operator delete[], are
15036 // described completely in 3.7.3. The attributes and restrictions
15037 // found in the rest of this subclause do not apply to them unless
15038 // explicitly stated in 3.7.3.
15039 if (Op == OO_Delete || Op == OO_Array_Delete)
15040 return CheckOperatorDeleteDeclaration(*this, FnDecl);
15042 if (Op == OO_New || Op == OO_Array_New)
15043 return CheckOperatorNewDeclaration(*this, FnDecl);
15045 // C++ [over.oper]p6:
15046 // An operator function shall either be a non-static member
15047 // function or be a non-member function and have at least one
15048 // parameter whose type is a class, a reference to a class, an
15049 // enumeration, or a reference to an enumeration.
15050 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
15051 if (MethodDecl->isStatic())
15052 return Diag(FnDecl->getLocation(),
15053 diag::err_operator_overload_static) << FnDecl->getDeclName();
15055 bool ClassOrEnumParam = false;
15056 for (auto Param : FnDecl->parameters()) {
15057 QualType ParamType = Param->getType().getNonReferenceType();
15058 if (ParamType->isDependentType() || ParamType->isRecordType() ||
15059 ParamType->isEnumeralType()) {
15060 ClassOrEnumParam = true;
15065 if (!ClassOrEnumParam)
15066 return Diag(FnDecl->getLocation(),
15067 diag::err_operator_overload_needs_class_or_enum)
15068 << FnDecl->getDeclName();
15071 // C++ [over.oper]p8:
15072 // An operator function cannot have default arguments (8.3.6),
15073 // except where explicitly stated below.
15075 // Only the function-call operator allows default arguments
15076 // (C++ [over.call]p1).
15077 if (Op != OO_Call) {
15078 for (auto Param : FnDecl->parameters()) {
15079 if (Param->hasDefaultArg())
15080 return Diag(Param->getLocation(),
15081 diag::err_operator_overload_default_arg)
15082 << FnDecl->getDeclName() << Param->getDefaultArgRange();
15086 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
15087 { false, false, false }
15088 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
15089 , { Unary, Binary, MemberOnly }
15090 #include "clang/Basic/OperatorKinds.def"
15093 bool CanBeUnaryOperator = OperatorUses[Op][0];
15094 bool CanBeBinaryOperator = OperatorUses[Op][1];
15095 bool MustBeMemberOperator = OperatorUses[Op][2];
15097 // C++ [over.oper]p8:
15098 // [...] Operator functions cannot have more or fewer parameters
15099 // than the number required for the corresponding operator, as
15100 // described in the rest of this subclause.
15101 unsigned NumParams = FnDecl->getNumParams()
15102 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
15103 if (Op != OO_Call &&
15104 ((NumParams == 1 && !CanBeUnaryOperator) ||
15105 (NumParams == 2 && !CanBeBinaryOperator) ||
15106 (NumParams < 1) || (NumParams > 2))) {
15107 // We have the wrong number of parameters.
15108 unsigned ErrorKind;
15109 if (CanBeUnaryOperator && CanBeBinaryOperator) {
15110 ErrorKind = 2; // 2 -> unary or binary.
15111 } else if (CanBeUnaryOperator) {
15112 ErrorKind = 0; // 0 -> unary
15114 assert(CanBeBinaryOperator &&
15115 "All non-call overloaded operators are unary or binary!");
15116 ErrorKind = 1; // 1 -> binary
15119 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
15120 << FnDecl->getDeclName() << NumParams << ErrorKind;
15123 // Overloaded operators other than operator() cannot be variadic.
15124 if (Op != OO_Call &&
15125 FnDecl->getType()->castAs<FunctionProtoType>()->isVariadic()) {
15126 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
15127 << FnDecl->getDeclName();
15130 // Some operators must be non-static member functions.
15131 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
15132 return Diag(FnDecl->getLocation(),
15133 diag::err_operator_overload_must_be_member)
15134 << FnDecl->getDeclName();
15137 // C++ [over.inc]p1:
15138 // The user-defined function called operator++ implements the
15139 // prefix and postfix ++ operator. If this function is a member
15140 // function with no parameters, or a non-member function with one
15141 // parameter of class or enumeration type, it defines the prefix
15142 // increment operator ++ for objects of that type. If the function
15143 // is a member function with one parameter (which shall be of type
15144 // int) or a non-member function with two parameters (the second
15145 // of which shall be of type int), it defines the postfix
15146 // increment operator ++ for objects of that type.
15147 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
15148 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
15149 QualType ParamType = LastParam->getType();
15151 if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) &&
15152 !ParamType->isDependentType())
15153 return Diag(LastParam->getLocation(),
15154 diag::err_operator_overload_post_incdec_must_be_int)
15155 << LastParam->getType() << (Op == OO_MinusMinus);
15162 checkLiteralOperatorTemplateParameterList(Sema &SemaRef,
15163 FunctionTemplateDecl *TpDecl) {
15164 TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters();
15166 // Must have one or two template parameters.
15167 if (TemplateParams->size() == 1) {
15168 NonTypeTemplateParmDecl *PmDecl =
15169 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0));
15171 // The template parameter must be a char parameter pack.
15172 if (PmDecl && PmDecl->isTemplateParameterPack() &&
15173 SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy))
15176 } else if (TemplateParams->size() == 2) {
15177 TemplateTypeParmDecl *PmType =
15178 dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0));
15179 NonTypeTemplateParmDecl *PmArgs =
15180 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1));
15182 // The second template parameter must be a parameter pack with the
15183 // first template parameter as its type.
15184 if (PmType && PmArgs && !PmType->isTemplateParameterPack() &&
15185 PmArgs->isTemplateParameterPack()) {
15186 const TemplateTypeParmType *TArgs =
15187 PmArgs->getType()->getAs<TemplateTypeParmType>();
15188 if (TArgs && TArgs->getDepth() == PmType->getDepth() &&
15189 TArgs->getIndex() == PmType->getIndex()) {
15190 if (!SemaRef.inTemplateInstantiation())
15191 SemaRef.Diag(TpDecl->getLocation(),
15192 diag::ext_string_literal_operator_template);
15198 SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(),
15199 diag::err_literal_operator_template)
15200 << TpDecl->getTemplateParameters()->getSourceRange();
15204 /// CheckLiteralOperatorDeclaration - Check whether the declaration
15205 /// of this literal operator function is well-formed. If so, returns
15206 /// false; otherwise, emits appropriate diagnostics and returns true.
15207 bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
15208 if (isa<CXXMethodDecl>(FnDecl)) {
15209 Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
15210 << FnDecl->getDeclName();
15214 if (FnDecl->isExternC()) {
15215 Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
15216 if (const LinkageSpecDecl *LSD =
15217 FnDecl->getDeclContext()->getExternCContext())
15218 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
15222 // This might be the definition of a literal operator template.
15223 FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
15225 // This might be a specialization of a literal operator template.
15227 TpDecl = FnDecl->getPrimaryTemplate();
15229 // template <char...> type operator "" name() and
15230 // template <class T, T...> type operator "" name() are the only valid
15231 // template signatures, and the only valid signatures with no parameters.
15233 if (FnDecl->param_size() != 0) {
15234 Diag(FnDecl->getLocation(),
15235 diag::err_literal_operator_template_with_params);
15239 if (checkLiteralOperatorTemplateParameterList(*this, TpDecl))
15242 } else if (FnDecl->param_size() == 1) {
15243 const ParmVarDecl *Param = FnDecl->getParamDecl(0);
15245 QualType ParamType = Param->getType().getUnqualifiedType();
15247 // Only unsigned long long int, long double, any character type, and const
15248 // char * are allowed as the only parameters.
15249 if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) ||
15250 ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) ||
15251 Context.hasSameType(ParamType, Context.CharTy) ||
15252 Context.hasSameType(ParamType, Context.WideCharTy) ||
15253 Context.hasSameType(ParamType, Context.Char8Ty) ||
15254 Context.hasSameType(ParamType, Context.Char16Ty) ||
15255 Context.hasSameType(ParamType, Context.Char32Ty)) {
15256 } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) {
15257 QualType InnerType = Ptr->getPointeeType();
15259 // Pointer parameter must be a const char *.
15260 if (!(Context.hasSameType(InnerType.getUnqualifiedType(),
15262 InnerType.isConstQualified() && !InnerType.isVolatileQualified())) {
15263 Diag(Param->getSourceRange().getBegin(),
15264 diag::err_literal_operator_param)
15265 << ParamType << "'const char *'" << Param->getSourceRange();
15269 } else if (ParamType->isRealFloatingType()) {
15270 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15271 << ParamType << Context.LongDoubleTy << Param->getSourceRange();
15274 } else if (ParamType->isIntegerType()) {
15275 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
15276 << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange();
15280 Diag(Param->getSourceRange().getBegin(),
15281 diag::err_literal_operator_invalid_param)
15282 << ParamType << Param->getSourceRange();
15286 } else if (FnDecl->param_size() == 2) {
15287 FunctionDecl::param_iterator Param = FnDecl->param_begin();
15289 // First, verify that the first parameter is correct.
15291 QualType FirstParamType = (*Param)->getType().getUnqualifiedType();
15293 // Two parameter function must have a pointer to const as a
15294 // first parameter; let's strip those qualifiers.
15295 const PointerType *PT = FirstParamType->getAs<PointerType>();
15298 Diag((*Param)->getSourceRange().getBegin(),
15299 diag::err_literal_operator_param)
15300 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15304 QualType PointeeType = PT->getPointeeType();
15305 // First parameter must be const
15306 if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) {
15307 Diag((*Param)->getSourceRange().getBegin(),
15308 diag::err_literal_operator_param)
15309 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15313 QualType InnerType = PointeeType.getUnqualifiedType();
15314 // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and
15315 // const char32_t* are allowed as the first parameter to a two-parameter
15317 if (!(Context.hasSameType(InnerType, Context.CharTy) ||
15318 Context.hasSameType(InnerType, Context.WideCharTy) ||
15319 Context.hasSameType(InnerType, Context.Char8Ty) ||
15320 Context.hasSameType(InnerType, Context.Char16Ty) ||
15321 Context.hasSameType(InnerType, Context.Char32Ty))) {
15322 Diag((*Param)->getSourceRange().getBegin(),
15323 diag::err_literal_operator_param)
15324 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
15328 // Move on to the second and final parameter.
15331 // The second parameter must be a std::size_t.
15332 QualType SecondParamType = (*Param)->getType().getUnqualifiedType();
15333 if (!Context.hasSameType(SecondParamType, Context.getSizeType())) {
15334 Diag((*Param)->getSourceRange().getBegin(),
15335 diag::err_literal_operator_param)
15336 << SecondParamType << Context.getSizeType()
15337 << (*Param)->getSourceRange();
15341 Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count);
15345 // Parameters are good.
15347 // A parameter-declaration-clause containing a default argument is not
15348 // equivalent to any of the permitted forms.
15349 for (auto Param : FnDecl->parameters()) {
15350 if (Param->hasDefaultArg()) {
15351 Diag(Param->getDefaultArgRange().getBegin(),
15352 diag::err_literal_operator_default_argument)
15353 << Param->getDefaultArgRange();
15358 StringRef LiteralName
15359 = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
15360 if (LiteralName[0] != '_' &&
15361 !getSourceManager().isInSystemHeader(FnDecl->getLocation())) {
15362 // C++11 [usrlit.suffix]p1:
15363 // Literal suffix identifiers that do not start with an underscore
15364 // are reserved for future standardization.
15365 Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved)
15366 << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName);
15372 /// ActOnStartLinkageSpecification - Parsed the beginning of a C++
15373 /// linkage specification, including the language and (if present)
15374 /// the '{'. ExternLoc is the location of the 'extern', Lang is the
15375 /// language string literal. LBraceLoc, if valid, provides the location of
15376 /// the '{' brace. Otherwise, this linkage specification does not
15377 /// have any braces.
15378 Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
15380 SourceLocation LBraceLoc) {
15381 StringLiteral *Lit = cast<StringLiteral>(LangStr);
15382 if (!Lit->isAscii()) {
15383 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii)
15384 << LangStr->getSourceRange();
15388 StringRef Lang = Lit->getString();
15389 LinkageSpecDecl::LanguageIDs Language;
15391 Language = LinkageSpecDecl::lang_c;
15392 else if (Lang == "C++")
15393 Language = LinkageSpecDecl::lang_cxx;
15395 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown)
15396 << LangStr->getSourceRange();
15400 // FIXME: Add all the various semantics of linkage specifications
15402 LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc,
15403 LangStr->getExprLoc(), Language,
15404 LBraceLoc.isValid());
15405 CurContext->addDecl(D);
15406 PushDeclContext(S, D);
15410 /// ActOnFinishLinkageSpecification - Complete the definition of
15411 /// the C++ linkage specification LinkageSpec. If RBraceLoc is
15412 /// valid, it's the position of the closing '}' brace in a linkage
15413 /// specification that uses braces.
15414 Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
15416 SourceLocation RBraceLoc) {
15417 if (RBraceLoc.isValid()) {
15418 LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
15419 LSDecl->setRBraceLoc(RBraceLoc);
15422 return LinkageSpec;
15425 Decl *Sema::ActOnEmptyDeclaration(Scope *S,
15426 const ParsedAttributesView &AttrList,
15427 SourceLocation SemiLoc) {
15428 Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc);
15429 // Attribute declarations appertain to empty declaration so we handle
15431 ProcessDeclAttributeList(S, ED, AttrList);
15433 CurContext->addDecl(ED);
15437 /// Perform semantic analysis for the variable declaration that
15438 /// occurs within a C++ catch clause, returning the newly-created
15440 VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
15441 TypeSourceInfo *TInfo,
15442 SourceLocation StartLoc,
15443 SourceLocation Loc,
15444 IdentifierInfo *Name) {
15445 bool Invalid = false;
15446 QualType ExDeclType = TInfo->getType();
15448 // Arrays and functions decay.
15449 if (ExDeclType->isArrayType())
15450 ExDeclType = Context.getArrayDecayedType(ExDeclType);
15451 else if (ExDeclType->isFunctionType())
15452 ExDeclType = Context.getPointerType(ExDeclType);
15454 // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
15455 // The exception-declaration shall not denote a pointer or reference to an
15456 // incomplete type, other than [cv] void*.
15457 // N2844 forbids rvalue references.
15458 if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
15459 Diag(Loc, diag::err_catch_rvalue_ref);
15463 if (ExDeclType->isVariablyModifiedType()) {
15464 Diag(Loc, diag::err_catch_variably_modified) << ExDeclType;
15468 QualType BaseType = ExDeclType;
15469 int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
15470 unsigned DK = diag::err_catch_incomplete;
15471 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
15472 BaseType = Ptr->getPointeeType();
15474 DK = diag::err_catch_incomplete_ptr;
15475 } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
15476 // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
15477 BaseType = Ref->getPointeeType();
15479 DK = diag::err_catch_incomplete_ref;
15481 if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
15482 !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
15485 if (!Invalid && !ExDeclType->isDependentType() &&
15486 RequireNonAbstractType(Loc, ExDeclType,
15487 diag::err_abstract_type_in_decl,
15488 AbstractVariableType))
15491 // Only the non-fragile NeXT runtime currently supports C++ catches
15492 // of ObjC types, and no runtime supports catching ObjC types by value.
15493 if (!Invalid && getLangOpts().ObjC) {
15494 QualType T = ExDeclType;
15495 if (const ReferenceType *RT = T->getAs<ReferenceType>())
15496 T = RT->getPointeeType();
15498 if (T->isObjCObjectType()) {
15499 Diag(Loc, diag::err_objc_object_catch);
15501 } else if (T->isObjCObjectPointerType()) {
15502 // FIXME: should this be a test for macosx-fragile specifically?
15503 if (getLangOpts().ObjCRuntime.isFragile())
15504 Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
15508 VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
15509 ExDeclType, TInfo, SC_None);
15510 ExDecl->setExceptionVariable(true);
15512 // In ARC, infer 'retaining' for variables of retainable type.
15513 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
15516 if (!Invalid && !ExDeclType->isDependentType()) {
15517 if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
15518 // Insulate this from anything else we might currently be parsing.
15519 EnterExpressionEvaluationContext scope(
15520 *this, ExpressionEvaluationContext::PotentiallyEvaluated);
15522 // C++ [except.handle]p16:
15523 // The object declared in an exception-declaration or, if the
15524 // exception-declaration does not specify a name, a temporary (12.2) is
15525 // copy-initialized (8.5) from the exception object. [...]
15526 // The object is destroyed when the handler exits, after the destruction
15527 // of any automatic objects initialized within the handler.
15529 // We just pretend to initialize the object with itself, then make sure
15530 // it can be destroyed later.
15531 QualType initType = Context.getExceptionObjectType(ExDeclType);
15533 InitializedEntity entity =
15534 InitializedEntity::InitializeVariable(ExDecl);
15535 InitializationKind initKind =
15536 InitializationKind::CreateCopy(Loc, SourceLocation());
15538 Expr *opaqueValue =
15539 new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
15540 InitializationSequence sequence(*this, entity, initKind, opaqueValue);
15541 ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue);
15542 if (result.isInvalid())
15545 // If the constructor used was non-trivial, set this as the
15547 CXXConstructExpr *construct = result.getAs<CXXConstructExpr>();
15548 if (!construct->getConstructor()->isTrivial()) {
15549 Expr *init = MaybeCreateExprWithCleanups(construct);
15550 ExDecl->setInit(init);
15553 // And make sure it's destructable.
15554 FinalizeVarWithDestructor(ExDecl, recordType);
15560 ExDecl->setInvalidDecl();
15565 /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
15567 Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
15568 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15569 bool Invalid = D.isInvalidType();
15571 // Check for unexpanded parameter packs.
15572 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
15573 UPPC_ExceptionType)) {
15574 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
15575 D.getIdentifierLoc());
15579 IdentifierInfo *II = D.getIdentifier();
15580 if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
15581 LookupOrdinaryName,
15582 ForVisibleRedeclaration)) {
15583 // The scope should be freshly made just for us. There is just no way
15584 // it contains any previous declaration, except for function parameters in
15585 // a function-try-block's catch statement.
15586 assert(!S->isDeclScope(PrevDecl));
15587 if (isDeclInScope(PrevDecl, CurContext, S)) {
15588 Diag(D.getIdentifierLoc(), diag::err_redefinition)
15589 << D.getIdentifier();
15590 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
15592 } else if (PrevDecl->isTemplateParameter())
15593 // Maybe we will complain about the shadowed template parameter.
15594 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
15597 if (D.getCXXScopeSpec().isSet() && !Invalid) {
15598 Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
15599 << D.getCXXScopeSpec().getRange();
15603 VarDecl *ExDecl = BuildExceptionDeclaration(
15604 S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier());
15606 ExDecl->setInvalidDecl();
15608 // Add the exception declaration into this scope.
15610 PushOnScopeChains(ExDecl, S);
15612 CurContext->addDecl(ExDecl);
15614 ProcessDeclAttributes(S, ExDecl, D);
15618 Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
15620 Expr *AssertMessageExpr,
15621 SourceLocation RParenLoc) {
15622 StringLiteral *AssertMessage =
15623 AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr;
15625 if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
15628 return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
15629 AssertMessage, RParenLoc, false);
15632 Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
15634 StringLiteral *AssertMessage,
15635 SourceLocation RParenLoc,
15637 assert(AssertExpr != nullptr && "Expected non-null condition");
15638 if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
15640 // In a static_assert-declaration, the constant-expression shall be a
15641 // constant expression that can be contextually converted to bool.
15642 ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
15643 if (Converted.isInvalid())
15646 ExprResult FullAssertExpr =
15647 ActOnFinishFullExpr(Converted.get(), StaticAssertLoc,
15648 /*DiscardedValue*/ false,
15649 /*IsConstexpr*/ true);
15650 if (FullAssertExpr.isInvalid())
15653 AssertExpr = FullAssertExpr.get();
15656 if (!Failed && VerifyIntegerConstantExpression(AssertExpr, &Cond,
15657 diag::err_static_assert_expression_is_not_constant,
15658 /*AllowFold=*/false).isInvalid())
15661 if (!Failed && !Cond) {
15662 SmallString<256> MsgBuffer;
15663 llvm::raw_svector_ostream Msg(MsgBuffer);
15665 AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy());
15667 Expr *InnerCond = nullptr;
15668 std::string InnerCondDescription;
15669 std::tie(InnerCond, InnerCondDescription) =
15670 findFailedBooleanCondition(Converted.get());
15671 if (InnerCond && isa<ConceptSpecializationExpr>(InnerCond)) {
15672 // Drill down into concept specialization expressions to see why they
15673 // weren't satisfied.
15674 Diag(StaticAssertLoc, diag::err_static_assert_failed)
15675 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
15676 ConstraintSatisfaction Satisfaction;
15677 if (!CheckConstraintSatisfaction(InnerCond, Satisfaction))
15678 DiagnoseUnsatisfiedConstraint(Satisfaction);
15679 } else if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond)
15680 && !isa<IntegerLiteral>(InnerCond)) {
15681 Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed)
15682 << InnerCondDescription << !AssertMessage
15683 << Msg.str() << InnerCond->getSourceRange();
15685 Diag(StaticAssertLoc, diag::err_static_assert_failed)
15686 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
15691 ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc,
15692 /*DiscardedValue*/false,
15693 /*IsConstexpr*/true);
15694 if (FullAssertExpr.isInvalid())
15697 AssertExpr = FullAssertExpr.get();
15700 Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
15701 AssertExpr, AssertMessage, RParenLoc,
15704 CurContext->addDecl(Decl);
15708 /// Perform semantic analysis of the given friend type declaration.
15710 /// \returns A friend declaration that.
15711 FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
15712 SourceLocation FriendLoc,
15713 TypeSourceInfo *TSInfo) {
15714 assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
15716 QualType T = TSInfo->getType();
15717 SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
15719 // C++03 [class.friend]p2:
15720 // An elaborated-type-specifier shall be used in a friend declaration
15723 // * The class-key of the elaborated-type-specifier is required.
15724 if (!CodeSynthesisContexts.empty()) {
15725 // Do not complain about the form of friend template types during any kind
15726 // of code synthesis. For template instantiation, we will have complained
15727 // when the template was defined.
15729 if (!T->isElaboratedTypeSpecifier()) {
15730 // If we evaluated the type to a record type, suggest putting
15732 if (const RecordType *RT = T->getAs<RecordType>()) {
15733 RecordDecl *RD = RT->getDecl();
15735 SmallString<16> InsertionText(" ");
15736 InsertionText += RD->getKindName();
15738 Diag(TypeRange.getBegin(),
15739 getLangOpts().CPlusPlus11 ?
15740 diag::warn_cxx98_compat_unelaborated_friend_type :
15741 diag::ext_unelaborated_friend_type)
15742 << (unsigned) RD->getTagKind()
15744 << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc),
15748 getLangOpts().CPlusPlus11 ?
15749 diag::warn_cxx98_compat_nonclass_type_friend :
15750 diag::ext_nonclass_type_friend)
15754 } else if (T->getAs<EnumType>()) {
15756 getLangOpts().CPlusPlus11 ?
15757 diag::warn_cxx98_compat_enum_friend :
15758 diag::ext_enum_friend)
15763 // C++11 [class.friend]p3:
15764 // A friend declaration that does not declare a function shall have one
15765 // of the following forms:
15766 // friend elaborated-type-specifier ;
15767 // friend simple-type-specifier ;
15768 // friend typename-specifier ;
15769 if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc)
15770 Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T;
15773 // If the type specifier in a friend declaration designates a (possibly
15774 // cv-qualified) class type, that class is declared as a friend; otherwise,
15775 // the friend declaration is ignored.
15776 return FriendDecl::Create(Context, CurContext,
15777 TSInfo->getTypeLoc().getBeginLoc(), TSInfo,
15781 /// Handle a friend tag declaration where the scope specifier was
15783 Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
15784 unsigned TagSpec, SourceLocation TagLoc,
15785 CXXScopeSpec &SS, IdentifierInfo *Name,
15786 SourceLocation NameLoc,
15787 const ParsedAttributesView &Attr,
15788 MultiTemplateParamsArg TempParamLists) {
15789 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
15791 bool IsMemberSpecialization = false;
15792 bool Invalid = false;
15794 if (TemplateParameterList *TemplateParams =
15795 MatchTemplateParametersToScopeSpecifier(
15796 TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true,
15797 IsMemberSpecialization, Invalid)) {
15798 if (TemplateParams->size() > 0) {
15799 // This is a declaration of a class template.
15803 return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name,
15804 NameLoc, Attr, TemplateParams, AS_public,
15805 /*ModulePrivateLoc=*/SourceLocation(),
15806 FriendLoc, TempParamLists.size() - 1,
15807 TempParamLists.data()).get();
15809 // The "template<>" header is extraneous.
15810 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
15811 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
15812 IsMemberSpecialization = true;
15816 if (Invalid) return nullptr;
15818 bool isAllExplicitSpecializations = true;
15819 for (unsigned I = TempParamLists.size(); I-- > 0; ) {
15820 if (TempParamLists[I]->size()) {
15821 isAllExplicitSpecializations = false;
15826 // FIXME: don't ignore attributes.
15828 // If it's explicit specializations all the way down, just forget
15829 // about the template header and build an appropriate non-templated
15830 // friend. TODO: for source fidelity, remember the headers.
15831 if (isAllExplicitSpecializations) {
15832 if (SS.isEmpty()) {
15833 bool Owned = false;
15834 bool IsDependent = false;
15835 return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
15837 /*ModulePrivateLoc=*/SourceLocation(),
15838 MultiTemplateParamsArg(), Owned, IsDependent,
15839 /*ScopedEnumKWLoc=*/SourceLocation(),
15840 /*ScopedEnumUsesClassTag=*/false,
15841 /*UnderlyingType=*/TypeResult(),
15842 /*IsTypeSpecifier=*/false,
15843 /*IsTemplateParamOrArg=*/false);
15846 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
15847 ElaboratedTypeKeyword Keyword
15848 = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
15849 QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
15854 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
15855 if (isa<DependentNameType>(T)) {
15856 DependentNameTypeLoc TL =
15857 TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
15858 TL.setElaboratedKeywordLoc(TagLoc);
15859 TL.setQualifierLoc(QualifierLoc);
15860 TL.setNameLoc(NameLoc);
15862 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
15863 TL.setElaboratedKeywordLoc(TagLoc);
15864 TL.setQualifierLoc(QualifierLoc);
15865 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc);
15868 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
15869 TSI, FriendLoc, TempParamLists);
15870 Friend->setAccess(AS_public);
15871 CurContext->addDecl(Friend);
15875 assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
15879 // Handle the case of a templated-scope friend class. e.g.
15880 // template <class T> class A<T>::B;
15881 // FIXME: we don't support these right now.
15882 Diag(NameLoc, diag::warn_template_qualified_friend_unsupported)
15883 << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext);
15884 ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
15885 QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
15886 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
15887 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
15888 TL.setElaboratedKeywordLoc(TagLoc);
15889 TL.setQualifierLoc(SS.getWithLocInContext(Context));
15890 TL.setNameLoc(NameLoc);
15892 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
15893 TSI, FriendLoc, TempParamLists);
15894 Friend->setAccess(AS_public);
15895 Friend->setUnsupportedFriend(true);
15896 CurContext->addDecl(Friend);
15900 /// Handle a friend type declaration. This works in tandem with
15903 /// Notes on friend class templates:
15905 /// We generally treat friend class declarations as if they were
15906 /// declaring a class. So, for example, the elaborated type specifier
15907 /// in a friend declaration is required to obey the restrictions of a
15908 /// class-head (i.e. no typedefs in the scope chain), template
15909 /// parameters are required to match up with simple template-ids, &c.
15910 /// However, unlike when declaring a template specialization, it's
15911 /// okay to refer to a template specialization without an empty
15912 /// template parameter declaration, e.g.
15913 /// friend class A<T>::B<unsigned>;
15914 /// We permit this as a special case; if there are any template
15915 /// parameters present at all, require proper matching, i.e.
15916 /// template <> template \<class T> friend class A<int>::B;
15917 Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
15918 MultiTemplateParamsArg TempParams) {
15919 SourceLocation Loc = DS.getBeginLoc();
15921 assert(DS.isFriendSpecified());
15922 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
15924 // C++ [class.friend]p3:
15925 // A friend declaration that does not declare a function shall have one of
15926 // the following forms:
15927 // friend elaborated-type-specifier ;
15928 // friend simple-type-specifier ;
15929 // friend typename-specifier ;
15931 // Any declaration with a type qualifier does not have that form. (It's
15932 // legal to specify a qualified type as a friend, you just can't write the
15934 if (DS.getTypeQualifiers()) {
15935 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
15936 Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const";
15937 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
15938 Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile";
15939 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
15940 Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict";
15941 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
15942 Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic";
15943 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
15944 Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned";
15947 // Try to convert the decl specifier to a type. This works for
15948 // friend templates because ActOnTag never produces a ClassTemplateDecl
15949 // for a TUK_Friend.
15950 Declarator TheDeclarator(DS, DeclaratorContext::MemberContext);
15951 TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
15952 QualType T = TSI->getType();
15953 if (TheDeclarator.isInvalidType())
15956 if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
15959 // This is definitely an error in C++98. It's probably meant to
15960 // be forbidden in C++0x, too, but the specification is just
15963 // The problem is with declarations like the following:
15964 // template <T> friend A<T>::foo;
15965 // where deciding whether a class C is a friend or not now hinges
15966 // on whether there exists an instantiation of A that causes
15967 // 'foo' to equal C. There are restrictions on class-heads
15968 // (which we declare (by fiat) elaborated friend declarations to
15969 // be) that makes this tractable.
15971 // FIXME: handle "template <> friend class A<T>;", which
15972 // is possibly well-formed? Who even knows?
15973 if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
15974 Diag(Loc, diag::err_tagless_friend_type_template)
15975 << DS.getSourceRange();
15979 // C++98 [class.friend]p1: A friend of a class is a function
15980 // or class that is not a member of the class . . .
15981 // This is fixed in DR77, which just barely didn't make the C++03
15982 // deadline. It's also a very silly restriction that seriously
15983 // affects inner classes and which nobody else seems to implement;
15984 // thus we never diagnose it, not even in -pedantic.
15986 // But note that we could warn about it: it's always useless to
15987 // friend one of your own members (it's not, however, worthless to
15988 // friend a member of an arbitrary specialization of your template).
15991 if (!TempParams.empty())
15992 D = FriendTemplateDecl::Create(Context, CurContext, Loc,
15995 DS.getFriendSpecLoc());
15997 D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
16002 D->setAccess(AS_public);
16003 CurContext->addDecl(D);
16008 NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
16009 MultiTemplateParamsArg TemplateParams) {
16010 const DeclSpec &DS = D.getDeclSpec();
16012 assert(DS.isFriendSpecified());
16013 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
16015 SourceLocation Loc = D.getIdentifierLoc();
16016 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
16018 // C++ [class.friend]p1
16019 // A friend of a class is a function or class....
16020 // Note that this sees through typedefs, which is intended.
16021 // It *doesn't* see through dependent types, which is correct
16022 // according to [temp.arg.type]p3:
16023 // If a declaration acquires a function type through a
16024 // type dependent on a template-parameter and this causes
16025 // a declaration that does not use the syntactic form of a
16026 // function declarator to have a function type, the program
16028 if (!TInfo->getType()->isFunctionType()) {
16029 Diag(Loc, diag::err_unexpected_friend);
16031 // It might be worthwhile to try to recover by creating an
16032 // appropriate declaration.
16036 // C++ [namespace.memdef]p3
16037 // - If a friend declaration in a non-local class first declares a
16038 // class or function, the friend class or function is a member
16039 // of the innermost enclosing namespace.
16040 // - The name of the friend is not found by simple name lookup
16041 // until a matching declaration is provided in that namespace
16042 // scope (either before or after the class declaration granting
16044 // - If a friend function is called, its name may be found by the
16045 // name lookup that considers functions from namespaces and
16046 // classes associated with the types of the function arguments.
16047 // - When looking for a prior declaration of a class or a function
16048 // declared as a friend, scopes outside the innermost enclosing
16049 // namespace scope are not considered.
16051 CXXScopeSpec &SS = D.getCXXScopeSpec();
16052 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
16053 assert(NameInfo.getName());
16055 // Check for unexpanded parameter packs.
16056 if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
16057 DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
16058 DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
16061 // The context we found the declaration in, or in which we should
16062 // create the declaration.
16064 Scope *DCScope = S;
16065 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
16066 ForExternalRedeclaration);
16068 // There are five cases here.
16069 // - There's no scope specifier and we're in a local class. Only look
16070 // for functions declared in the immediately-enclosing block scope.
16071 // We recover from invalid scope qualifiers as if they just weren't there.
16072 FunctionDecl *FunctionContainingLocalClass = nullptr;
16073 if ((SS.isInvalid() || !SS.isSet()) &&
16074 (FunctionContainingLocalClass =
16075 cast<CXXRecordDecl>(CurContext)->isLocalClass())) {
16076 // C++11 [class.friend]p11:
16077 // If a friend declaration appears in a local class and the name
16078 // specified is an unqualified name, a prior declaration is
16079 // looked up without considering scopes that are outside the
16080 // innermost enclosing non-class scope. For a friend function
16081 // declaration, if there is no prior declaration, the program is
16084 // Find the innermost enclosing non-class scope. This is the block
16085 // scope containing the local class definition (or for a nested class,
16086 // the outer local class).
16087 DCScope = S->getFnParent();
16089 // Look up the function name in the scope.
16090 Previous.clear(LookupLocalFriendName);
16091 LookupName(Previous, S, /*AllowBuiltinCreation*/false);
16093 if (!Previous.empty()) {
16094 // All possible previous declarations must have the same context:
16095 // either they were declared at block scope or they are members of
16096 // one of the enclosing local classes.
16097 DC = Previous.getRepresentativeDecl()->getDeclContext();
16099 // This is ill-formed, but provide the context that we would have
16100 // declared the function in, if we were permitted to, for error recovery.
16101 DC = FunctionContainingLocalClass;
16103 adjustContextForLocalExternDecl(DC);
16105 // C++ [class.friend]p6:
16106 // A function can be defined in a friend declaration of a class if and
16107 // only if the class is a non-local class (9.8), the function name is
16108 // unqualified, and the function has namespace scope.
16109 if (D.isFunctionDefinition()) {
16110 Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
16113 // - There's no scope specifier, in which case we just go to the
16114 // appropriate scope and look for a function or function template
16115 // there as appropriate.
16116 } else if (SS.isInvalid() || !SS.isSet()) {
16117 // C++11 [namespace.memdef]p3:
16118 // If the name in a friend declaration is neither qualified nor
16119 // a template-id and the declaration is a function or an
16120 // elaborated-type-specifier, the lookup to determine whether
16121 // the entity has been previously declared shall not consider
16122 // any scopes outside the innermost enclosing namespace.
16123 bool isTemplateId =
16124 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId;
16126 // Find the appropriate context according to the above.
16129 // Skip class contexts. If someone can cite chapter and verse
16130 // for this behavior, that would be nice --- it's what GCC and
16131 // EDG do, and it seems like a reasonable intent, but the spec
16132 // really only says that checks for unqualified existing
16133 // declarations should stop at the nearest enclosing namespace,
16134 // not that they should only consider the nearest enclosing
16136 while (DC->isRecord())
16137 DC = DC->getParent();
16139 DeclContext *LookupDC = DC;
16140 while (LookupDC->isTransparentContext())
16141 LookupDC = LookupDC->getParent();
16144 LookupQualifiedName(Previous, LookupDC);
16146 if (!Previous.empty()) {
16151 if (isTemplateId) {
16152 if (isa<TranslationUnitDecl>(LookupDC)) break;
16154 if (LookupDC->isFileContext()) break;
16156 LookupDC = LookupDC->getParent();
16159 DCScope = getScopeForDeclContext(S, DC);
16161 // - There's a non-dependent scope specifier, in which case we
16162 // compute it and do a previous lookup there for a function
16163 // or function template.
16164 } else if (!SS.getScopeRep()->isDependent()) {
16165 DC = computeDeclContext(SS);
16166 if (!DC) return nullptr;
16168 if (RequireCompleteDeclContext(SS, DC)) return nullptr;
16170 LookupQualifiedName(Previous, DC);
16172 // C++ [class.friend]p1: A friend of a class is a function or
16173 // class that is not a member of the class . . .
16174 if (DC->Equals(CurContext))
16175 Diag(DS.getFriendSpecLoc(),
16176 getLangOpts().CPlusPlus11 ?
16177 diag::warn_cxx98_compat_friend_is_member :
16178 diag::err_friend_is_member);
16180 if (D.isFunctionDefinition()) {
16181 // C++ [class.friend]p6:
16182 // A function can be defined in a friend declaration of a class if and
16183 // only if the class is a non-local class (9.8), the function name is
16184 // unqualified, and the function has namespace scope.
16186 // FIXME: We should only do this if the scope specifier names the
16187 // innermost enclosing namespace; otherwise the fixit changes the
16188 // meaning of the code.
16189 SemaDiagnosticBuilder DB
16190 = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
16192 DB << SS.getScopeRep();
16193 if (DC->isFileContext())
16194 DB << FixItHint::CreateRemoval(SS.getRange());
16198 // - There's a scope specifier that does not match any template
16199 // parameter lists, in which case we use some arbitrary context,
16200 // create a method or method template, and wait for instantiation.
16201 // - There's a scope specifier that does match some template
16202 // parameter lists, which we don't handle right now.
16204 if (D.isFunctionDefinition()) {
16205 // C++ [class.friend]p6:
16206 // A function can be defined in a friend declaration of a class if and
16207 // only if the class is a non-local class (9.8), the function name is
16208 // unqualified, and the function has namespace scope.
16209 Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
16210 << SS.getScopeRep();
16214 assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
16217 if (!DC->isRecord()) {
16219 switch (D.getName().getKind()) {
16220 case UnqualifiedIdKind::IK_ConstructorTemplateId:
16221 case UnqualifiedIdKind::IK_ConstructorName:
16224 case UnqualifiedIdKind::IK_DestructorName:
16227 case UnqualifiedIdKind::IK_ConversionFunctionId:
16230 case UnqualifiedIdKind::IK_DeductionGuideName:
16233 case UnqualifiedIdKind::IK_Identifier:
16234 case UnqualifiedIdKind::IK_ImplicitSelfParam:
16235 case UnqualifiedIdKind::IK_LiteralOperatorId:
16236 case UnqualifiedIdKind::IK_OperatorFunctionId:
16237 case UnqualifiedIdKind::IK_TemplateId:
16240 // This implies that it has to be an operator or function.
16241 if (DiagArg >= 0) {
16242 Diag(Loc, diag::err_introducing_special_friend) << DiagArg;
16247 // FIXME: This is an egregious hack to cope with cases where the scope stack
16248 // does not contain the declaration context, i.e., in an out-of-line
16249 // definition of a class.
16250 Scope FakeDCScope(S, Scope::DeclScope, Diags);
16252 FakeDCScope.setEntity(DC);
16253 DCScope = &FakeDCScope;
16256 bool AddToScope = true;
16257 NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
16258 TemplateParams, AddToScope);
16259 if (!ND) return nullptr;
16261 assert(ND->getLexicalDeclContext() == CurContext);
16263 // If we performed typo correction, we might have added a scope specifier
16264 // and changed the decl context.
16265 DC = ND->getDeclContext();
16267 // Add the function declaration to the appropriate lookup tables,
16268 // adjusting the redeclarations list as necessary. We don't
16269 // want to do this yet if the friending class is dependent.
16271 // Also update the scope-based lookup if the target context's
16272 // lookup context is in lexical scope.
16273 if (!CurContext->isDependentContext()) {
16274 DC = DC->getRedeclContext();
16275 DC->makeDeclVisibleInContext(ND);
16276 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
16277 PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
16280 FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
16281 D.getIdentifierLoc(), ND,
16282 DS.getFriendSpecLoc());
16283 FrD->setAccess(AS_public);
16284 CurContext->addDecl(FrD);
16286 if (ND->isInvalidDecl()) {
16287 FrD->setInvalidDecl();
16289 if (DC->isRecord()) CheckFriendAccess(ND);
16292 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
16293 FD = FTD->getTemplatedDecl();
16295 FD = cast<FunctionDecl>(ND);
16297 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a
16298 // default argument expression, that declaration shall be a definition
16299 // and shall be the only declaration of the function or function
16300 // template in the translation unit.
16301 if (functionDeclHasDefaultArgument(FD)) {
16302 // We can't look at FD->getPreviousDecl() because it may not have been set
16303 // if we're in a dependent context. If the function is known to be a
16304 // redeclaration, we will have narrowed Previous down to the right decl.
16305 if (D.isRedeclaration()) {
16306 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
16307 Diag(Previous.getRepresentativeDecl()->getLocation(),
16308 diag::note_previous_declaration);
16309 } else if (!D.isFunctionDefinition())
16310 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
16313 // Mark templated-scope function declarations as unsupported.
16314 if (FD->getNumTemplateParameterLists() && SS.isValid()) {
16315 Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported)
16316 << SS.getScopeRep() << SS.getRange()
16317 << cast<CXXRecordDecl>(CurContext);
16318 FrD->setUnsupportedFriend(true);
16325 void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
16326 AdjustDeclIfTemplate(Dcl);
16328 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl);
16330 Diag(DelLoc, diag::err_deleted_non_function);
16334 // Deleted function does not have a body.
16335 Fn->setWillHaveBody(false);
16337 if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
16338 // Don't consider the implicit declaration we generate for explicit
16339 // specializations. FIXME: Do not generate these implicit declarations.
16340 if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization ||
16341 Prev->getPreviousDecl()) &&
16342 !Prev->isDefined()) {
16343 Diag(DelLoc, diag::err_deleted_decl_not_first);
16344 Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(),
16345 Prev->isImplicit() ? diag::note_previous_implicit_declaration
16346 : diag::note_previous_declaration);
16348 // If the declaration wasn't the first, we delete the function anyway for
16350 Fn = Fn->getCanonicalDecl();
16353 // dllimport/dllexport cannot be deleted.
16354 if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) {
16355 Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr;
16356 Fn->setInvalidDecl();
16359 if (Fn->isDeleted())
16362 // C++11 [basic.start.main]p3:
16363 // A program that defines main as deleted [...] is ill-formed.
16365 Diag(DelLoc, diag::err_deleted_main);
16367 // C++11 [dcl.fct.def.delete]p4:
16368 // A deleted function is implicitly inline.
16369 Fn->setImplicitlyInline();
16370 Fn->setDeletedAsWritten();
16372 // See if we're deleting a function which is already known to override a
16373 // non-deleted virtual function.
16374 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn)) {
16375 bool IssuedDiagnostic = false;
16376 for (const CXXMethodDecl *O : MD->overridden_methods()) {
16377 if (!(*MD->begin_overridden_methods())->isDeleted()) {
16378 if (!IssuedDiagnostic) {
16379 Diag(DelLoc, diag::err_deleted_override) << MD->getDeclName();
16380 IssuedDiagnostic = true;
16382 Diag(O->getLocation(), diag::note_overridden_virtual_function);
16385 // If this function was implicitly deleted because it was defaulted,
16386 // explain why it was deleted.
16387 if (IssuedDiagnostic && MD->isDefaulted())
16388 DiagnoseDeletedDefaultedFunction(MD);
16392 void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
16393 if (!Dcl || Dcl->isInvalidDecl())
16396 auto *FD = dyn_cast<FunctionDecl>(Dcl);
16398 if (auto *FTD = dyn_cast<FunctionTemplateDecl>(Dcl)) {
16399 if (getDefaultedFunctionKind(FTD->getTemplatedDecl()).isComparison()) {
16400 Diag(DefaultLoc, diag::err_defaulted_comparison_template);
16405 Diag(DefaultLoc, diag::err_default_special_members)
16406 << getLangOpts().CPlusPlus2a;
16410 // Reject if this can't possibly be a defaultable function.
16411 DefaultedFunctionKind DefKind = getDefaultedFunctionKind(FD);
16413 // A dependent function that doesn't locally look defaultable can
16414 // still instantiate to a defaultable function if it's a constructor
16415 // or assignment operator.
16416 (!FD->isDependentContext() ||
16417 (!isa<CXXConstructorDecl>(FD) &&
16418 FD->getDeclName().getCXXOverloadedOperator() != OO_Equal))) {
16419 Diag(DefaultLoc, diag::err_default_special_members)
16420 << getLangOpts().CPlusPlus2a;
16424 if (DefKind.isComparison() &&
16425 !isa<CXXRecordDecl>(FD->getLexicalDeclContext())) {
16426 Diag(FD->getLocation(), diag::err_defaulted_comparison_out_of_class)
16427 << (int)DefKind.asComparison();
16431 // Issue compatibility warning. We already warned if the operator is
16432 // 'operator<=>' when parsing the '<=>' token.
16433 if (DefKind.isComparison() &&
16434 DefKind.asComparison() != DefaultedComparisonKind::ThreeWay) {
16435 Diag(DefaultLoc, getLangOpts().CPlusPlus2a
16436 ? diag::warn_cxx17_compat_defaulted_comparison
16437 : diag::ext_defaulted_comparison);
16440 FD->setDefaulted();
16441 FD->setExplicitlyDefaulted();
16443 // Defer checking functions that are defaulted in a dependent context.
16444 if (FD->isDependentContext())
16447 // Unset that we will have a body for this function. We might not,
16448 // if it turns out to be trivial, and we don't need this marking now
16449 // that we've marked it as defaulted.
16450 FD->setWillHaveBody(false);
16452 // If this definition appears within the record, do the checking when
16453 // the record is complete. This is always the case for a defaulted
16455 if (DefKind.isComparison())
16457 auto *MD = cast<CXXMethodDecl>(FD);
16459 const FunctionDecl *Primary = FD;
16460 if (const FunctionDecl *Pattern = FD->getTemplateInstantiationPattern())
16461 // Ask the template instantiation pattern that actually had the
16462 // '= default' on it.
16465 // If the method was defaulted on its first declaration, we will have
16466 // already performed the checking in CheckCompletedCXXClass. Such a
16467 // declaration doesn't trigger an implicit definition.
16468 if (Primary->getCanonicalDecl()->isDefaulted())
16471 if (CheckExplicitlyDefaultedSpecialMember(MD, DefKind.asSpecialMember()))
16472 MD->setInvalidDecl();
16474 DefineImplicitSpecialMember(*this, MD, DefaultLoc);
16477 static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
16478 for (Stmt *SubStmt : S->children()) {
16481 if (isa<ReturnStmt>(SubStmt))
16482 Self.Diag(SubStmt->getBeginLoc(),
16483 diag::err_return_in_constructor_handler);
16484 if (!isa<Expr>(SubStmt))
16485 SearchForReturnInStmt(Self, SubStmt);
16489 void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
16490 for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
16491 CXXCatchStmt *Handler = TryBlock->getHandler(I);
16492 SearchForReturnInStmt(*this, Handler);
16496 bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
16497 const CXXMethodDecl *Old) {
16498 const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
16499 const auto *OldFT = Old->getType()->castAs<FunctionProtoType>();
16501 if (OldFT->hasExtParameterInfos()) {
16502 for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
16503 // A parameter of the overriding method should be annotated with noescape
16504 // if the corresponding parameter of the overridden method is annotated.
16505 if (OldFT->getExtParameterInfo(I).isNoEscape() &&
16506 !NewFT->getExtParameterInfo(I).isNoEscape()) {
16507 Diag(New->getParamDecl(I)->getLocation(),
16508 diag::warn_overriding_method_missing_noescape);
16509 Diag(Old->getParamDecl(I)->getLocation(),
16510 diag::note_overridden_marked_noescape);
16514 // Virtual overrides must have the same code_seg.
16515 const auto *OldCSA = Old->getAttr<CodeSegAttr>();
16516 const auto *NewCSA = New->getAttr<CodeSegAttr>();
16517 if ((NewCSA || OldCSA) &&
16518 (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) {
16519 Diag(New->getLocation(), diag::err_mismatched_code_seg_override);
16520 Diag(Old->getLocation(), diag::note_previous_declaration);
16524 CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
16526 // If the calling conventions match, everything is fine
16527 if (NewCC == OldCC)
16530 // If the calling conventions mismatch because the new function is static,
16531 // suppress the calling convention mismatch error; the error about static
16532 // function override (err_static_overrides_virtual from
16533 // Sema::CheckFunctionDeclaration) is more clear.
16534 if (New->getStorageClass() == SC_Static)
16537 Diag(New->getLocation(),
16538 diag::err_conflicting_overriding_cc_attributes)
16539 << New->getDeclName() << New->getType() << Old->getType();
16540 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
16544 bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
16545 const CXXMethodDecl *Old) {
16546 QualType NewTy = New->getType()->castAs<FunctionType>()->getReturnType();
16547 QualType OldTy = Old->getType()->castAs<FunctionType>()->getReturnType();
16549 if (Context.hasSameType(NewTy, OldTy) ||
16550 NewTy->isDependentType() || OldTy->isDependentType())
16553 // Check if the return types are covariant
16554 QualType NewClassTy, OldClassTy;
16556 /// Both types must be pointers or references to classes.
16557 if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
16558 if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
16559 NewClassTy = NewPT->getPointeeType();
16560 OldClassTy = OldPT->getPointeeType();
16562 } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
16563 if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
16564 if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
16565 NewClassTy = NewRT->getPointeeType();
16566 OldClassTy = OldRT->getPointeeType();
16571 // The return types aren't either both pointers or references to a class type.
16572 if (NewClassTy.isNull()) {
16573 Diag(New->getLocation(),
16574 diag::err_different_return_type_for_overriding_virtual_function)
16575 << New->getDeclName() << NewTy << OldTy
16576 << New->getReturnTypeSourceRange();
16577 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
16578 << Old->getReturnTypeSourceRange();
16583 if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
16584 // C++14 [class.virtual]p8:
16585 // If the class type in the covariant return type of D::f differs from
16586 // that of B::f, the class type in the return type of D::f shall be
16587 // complete at the point of declaration of D::f or shall be the class
16589 if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
16590 if (!RT->isBeingDefined() &&
16591 RequireCompleteType(New->getLocation(), NewClassTy,
16592 diag::err_covariant_return_incomplete,
16593 New->getDeclName()))
16597 // Check if the new class derives from the old class.
16598 if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
16599 Diag(New->getLocation(), diag::err_covariant_return_not_derived)
16600 << New->getDeclName() << NewTy << OldTy
16601 << New->getReturnTypeSourceRange();
16602 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
16603 << Old->getReturnTypeSourceRange();
16607 // Check if we the conversion from derived to base is valid.
16608 if (CheckDerivedToBaseConversion(
16609 NewClassTy, OldClassTy,
16610 diag::err_covariant_return_inaccessible_base,
16611 diag::err_covariant_return_ambiguous_derived_to_base_conv,
16612 New->getLocation(), New->getReturnTypeSourceRange(),
16613 New->getDeclName(), nullptr)) {
16614 // FIXME: this note won't trigger for delayed access control
16615 // diagnostics, and it's impossible to get an undelayed error
16616 // here from access control during the original parse because
16617 // the ParsingDeclSpec/ParsingDeclarator are still in scope.
16618 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
16619 << Old->getReturnTypeSourceRange();
16624 // The qualifiers of the return types must be the same.
16625 if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
16626 Diag(New->getLocation(),
16627 diag::err_covariant_return_type_different_qualifications)
16628 << New->getDeclName() << NewTy << OldTy
16629 << New->getReturnTypeSourceRange();
16630 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
16631 << Old->getReturnTypeSourceRange();
16636 // The new class type must have the same or less qualifiers as the old type.
16637 if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
16638 Diag(New->getLocation(),
16639 diag::err_covariant_return_type_class_type_more_qualified)
16640 << New->getDeclName() << NewTy << OldTy
16641 << New->getReturnTypeSourceRange();
16642 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
16643 << Old->getReturnTypeSourceRange();
16650 /// Mark the given method pure.
16652 /// \param Method the method to be marked pure.
16654 /// \param InitRange the source range that covers the "0" initializer.
16655 bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
16656 SourceLocation EndLoc = InitRange.getEnd();
16657 if (EndLoc.isValid())
16658 Method->setRangeEnd(EndLoc);
16660 if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
16665 if (!Method->isInvalidDecl())
16666 Diag(Method->getLocation(), diag::err_non_virtual_pure)
16667 << Method->getDeclName() << InitRange;
16671 void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) {
16672 if (D->getFriendObjectKind())
16673 Diag(D->getLocation(), diag::err_pure_friend);
16674 else if (auto *M = dyn_cast<CXXMethodDecl>(D))
16675 CheckPureMethod(M, ZeroLoc);
16677 Diag(D->getLocation(), diag::err_illegal_initializer);
16680 /// Determine whether the given declaration is a global variable or
16681 /// static data member.
16682 static bool isNonlocalVariable(const Decl *D) {
16683 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
16684 return Var->hasGlobalStorage();
16689 /// Invoked when we are about to parse an initializer for the declaration
16692 /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
16693 /// static data member of class X, names should be looked up in the scope of
16694 /// class X. If the declaration had a scope specifier, a scope will have
16695 /// been created and passed in for this purpose. Otherwise, S will be null.
16696 void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
16697 // If there is no declaration, there was an error parsing it.
16698 if (!D || D->isInvalidDecl())
16701 // We will always have a nested name specifier here, but this declaration
16702 // might not be out of line if the specifier names the current namespace:
16705 if (S && D->isOutOfLine())
16706 EnterDeclaratorContext(S, D->getDeclContext());
16708 // If we are parsing the initializer for a static data member, push a
16709 // new expression evaluation context that is associated with this static
16711 if (isNonlocalVariable(D))
16712 PushExpressionEvaluationContext(
16713 ExpressionEvaluationContext::PotentiallyEvaluated, D);
16716 /// Invoked after we are finished parsing an initializer for the declaration D.
16717 void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
16718 // If there is no declaration, there was an error parsing it.
16719 if (!D || D->isInvalidDecl())
16722 if (isNonlocalVariable(D))
16723 PopExpressionEvaluationContext();
16725 if (S && D->isOutOfLine())
16726 ExitDeclaratorContext(S);
16729 /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
16730 /// C++ if/switch/while/for statement.
16731 /// e.g: "if (int x = f()) {...}"
16732 DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
16734 // The declarator shall not specify a function or an array.
16735 // The type-specifier-seq shall not contain typedef and shall not declare a
16736 // new class or enumeration.
16737 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
16738 "Parser allowed 'typedef' as storage class of condition decl.");
16740 Decl *Dcl = ActOnDeclarator(S, D);
16744 if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
16745 Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
16746 << D.getSourceRange();
16753 void Sema::LoadExternalVTableUses() {
16754 if (!ExternalSource)
16757 SmallVector<ExternalVTableUse, 4> VTables;
16758 ExternalSource->ReadUsedVTables(VTables);
16759 SmallVector<VTableUse, 4> NewUses;
16760 for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
16761 llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
16762 = VTablesUsed.find(VTables[I].Record);
16763 // Even if a definition wasn't required before, it may be required now.
16764 if (Pos != VTablesUsed.end()) {
16765 if (!Pos->second && VTables[I].DefinitionRequired)
16766 Pos->second = true;
16770 VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
16771 NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
16774 VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
16777 void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
16778 bool DefinitionRequired) {
16779 // Ignore any vtable uses in unevaluated operands or for classes that do
16780 // not have a vtable.
16781 if (!Class->isDynamicClass() || Class->isDependentContext() ||
16782 CurContext->isDependentContext() || isUnevaluatedContext())
16784 // Do not mark as used if compiling for the device outside of the target
16786 if (LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
16787 !isInOpenMPDeclareTargetContext() &&
16788 !isInOpenMPTargetExecutionDirective()) {
16789 if (!DefinitionRequired)
16790 MarkVirtualMembersReferenced(Loc, Class);
16794 // Try to insert this class into the map.
16795 LoadExternalVTableUses();
16796 Class = Class->getCanonicalDecl();
16797 std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
16798 Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
16800 // If we already had an entry, check to see if we are promoting this vtable
16801 // to require a definition. If so, we need to reappend to the VTableUses
16802 // list, since we may have already processed the first entry.
16803 if (DefinitionRequired && !Pos.first->second) {
16804 Pos.first->second = true;
16806 // Otherwise, we can early exit.
16810 // The Microsoft ABI requires that we perform the destructor body
16811 // checks (i.e. operator delete() lookup) when the vtable is marked used, as
16812 // the deleting destructor is emitted with the vtable, not with the
16813 // destructor definition as in the Itanium ABI.
16814 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
16815 CXXDestructorDecl *DD = Class->getDestructor();
16816 if (DD && DD->isVirtual() && !DD->isDeleted()) {
16817 if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
16818 // If this is an out-of-line declaration, marking it referenced will
16819 // not do anything. Manually call CheckDestructor to look up operator
16821 ContextRAII SavedContext(*this, DD);
16822 CheckDestructor(DD);
16824 MarkFunctionReferenced(Loc, Class->getDestructor());
16830 // Local classes need to have their virtual members marked
16831 // immediately. For all other classes, we mark their virtual members
16832 // at the end of the translation unit.
16833 if (Class->isLocalClass())
16834 MarkVirtualMembersReferenced(Loc, Class);
16836 VTableUses.push_back(std::make_pair(Class, Loc));
16839 bool Sema::DefineUsedVTables() {
16840 LoadExternalVTableUses();
16841 if (VTableUses.empty())
16844 // Note: The VTableUses vector could grow as a result of marking
16845 // the members of a class as "used", so we check the size each
16846 // time through the loop and prefer indices (which are stable) to
16847 // iterators (which are not).
16848 bool DefinedAnything = false;
16849 for (unsigned I = 0; I != VTableUses.size(); ++I) {
16850 CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
16853 TemplateSpecializationKind ClassTSK =
16854 Class->getTemplateSpecializationKind();
16856 SourceLocation Loc = VTableUses[I].second;
16858 bool DefineVTable = true;
16860 // If this class has a key function, but that key function is
16861 // defined in another translation unit, we don't need to emit the
16862 // vtable even though we're using it.
16863 const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
16864 if (KeyFunction && !KeyFunction->hasBody()) {
16865 // The key function is in another translation unit.
16866 DefineVTable = false;
16867 TemplateSpecializationKind TSK =
16868 KeyFunction->getTemplateSpecializationKind();
16869 assert(TSK != TSK_ExplicitInstantiationDefinition &&
16870 TSK != TSK_ImplicitInstantiation &&
16871 "Instantiations don't have key functions");
16873 } else if (!KeyFunction) {
16874 // If we have a class with no key function that is the subject
16875 // of an explicit instantiation declaration, suppress the
16876 // vtable; it will live with the explicit instantiation
16878 bool IsExplicitInstantiationDeclaration =
16879 ClassTSK == TSK_ExplicitInstantiationDeclaration;
16880 for (auto R : Class->redecls()) {
16881 TemplateSpecializationKind TSK
16882 = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind();
16883 if (TSK == TSK_ExplicitInstantiationDeclaration)
16884 IsExplicitInstantiationDeclaration = true;
16885 else if (TSK == TSK_ExplicitInstantiationDefinition) {
16886 IsExplicitInstantiationDeclaration = false;
16891 if (IsExplicitInstantiationDeclaration)
16892 DefineVTable = false;
16895 // The exception specifications for all virtual members may be needed even
16896 // if we are not providing an authoritative form of the vtable in this TU.
16897 // We may choose to emit it available_externally anyway.
16898 if (!DefineVTable) {
16899 MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
16903 // Mark all of the virtual members of this class as referenced, so
16904 // that we can build a vtable. Then, tell the AST consumer that a
16905 // vtable for this class is required.
16906 DefinedAnything = true;
16907 MarkVirtualMembersReferenced(Loc, Class);
16908 CXXRecordDecl *Canonical = Class->getCanonicalDecl();
16909 if (VTablesUsed[Canonical])
16910 Consumer.HandleVTable(Class);
16912 // Warn if we're emitting a weak vtable. The vtable will be weak if there is
16913 // no key function or the key function is inlined. Don't warn in C++ ABIs
16914 // that lack key functions, since the user won't be able to make one.
16915 if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() &&
16916 Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) {
16917 const FunctionDecl *KeyFunctionDef = nullptr;
16918 if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) &&
16919 KeyFunctionDef->isInlined())) {
16920 Diag(Class->getLocation(),
16921 ClassTSK == TSK_ExplicitInstantiationDefinition
16922 ? diag::warn_weak_template_vtable
16923 : diag::warn_weak_vtable)
16928 VTableUses.clear();
16930 return DefinedAnything;
16933 void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
16934 const CXXRecordDecl *RD) {
16935 for (const auto *I : RD->methods())
16936 if (I->isVirtual() && !I->isPure())
16937 ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>());
16940 void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
16941 const CXXRecordDecl *RD,
16942 bool ConstexprOnly) {
16943 // Mark all functions which will appear in RD's vtable as used.
16944 CXXFinalOverriderMap FinalOverriders;
16945 RD->getFinalOverriders(FinalOverriders);
16946 for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
16947 E = FinalOverriders.end();
16949 for (OverridingMethods::const_iterator OI = I->second.begin(),
16950 OE = I->second.end();
16952 assert(OI->second.size() > 0 && "no final overrider");
16953 CXXMethodDecl *Overrider = OI->second.front().Method;
16955 // C++ [basic.def.odr]p2:
16956 // [...] A virtual member function is used if it is not pure. [...]
16957 if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr()))
16958 MarkFunctionReferenced(Loc, Overrider);
16962 // Only classes that have virtual bases need a VTT.
16963 if (RD->getNumVBases() == 0)
16966 for (const auto &I : RD->bases()) {
16968 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
16969 if (Base->getNumVBases() == 0)
16971 MarkVirtualMembersReferenced(Loc, Base);
16975 /// SetIvarInitializers - This routine builds initialization ASTs for the
16976 /// Objective-C implementation whose ivars need be initialized.
16977 void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
16978 if (!getLangOpts().CPlusPlus)
16980 if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
16981 SmallVector<ObjCIvarDecl*, 8> ivars;
16982 CollectIvarsToConstructOrDestruct(OID, ivars);
16985 SmallVector<CXXCtorInitializer*, 32> AllToInit;
16986 for (unsigned i = 0; i < ivars.size(); i++) {
16987 FieldDecl *Field = ivars[i];
16988 if (Field->isInvalidDecl())
16991 CXXCtorInitializer *Member;
16992 InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
16993 InitializationKind InitKind =
16994 InitializationKind::CreateDefault(ObjCImplementation->getLocation());
16996 InitializationSequence InitSeq(*this, InitEntity, InitKind, None);
16997 ExprResult MemberInit =
16998 InitSeq.Perform(*this, InitEntity, InitKind, None);
16999 MemberInit = MaybeCreateExprWithCleanups(MemberInit);
17000 // Note, MemberInit could actually come back empty if no initialization
17001 // is required (e.g., because it would call a trivial default constructor)
17002 if (!MemberInit.get() || MemberInit.isInvalid())
17006 new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
17008 MemberInit.getAs<Expr>(),
17010 AllToInit.push_back(Member);
17012 // Be sure that the destructor is accessible and is marked as referenced.
17013 if (const RecordType *RecordTy =
17014 Context.getBaseElementType(Field->getType())
17015 ->getAs<RecordType>()) {
17016 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
17017 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
17018 MarkFunctionReferenced(Field->getLocation(), Destructor);
17019 CheckDestructorAccess(Field->getLocation(), Destructor,
17020 PDiag(diag::err_access_dtor_ivar)
17021 << Context.getBaseElementType(Field->getType()));
17025 ObjCImplementation->setIvarInitializers(Context,
17026 AllToInit.data(), AllToInit.size());
17031 void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
17032 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid,
17033 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid,
17034 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current,
17036 if (Ctor->isInvalidDecl())
17039 CXXConstructorDecl *Target = Ctor->getTargetConstructor();
17041 // Target may not be determinable yet, for instance if this is a dependent
17042 // call in an uninstantiated template.
17044 const FunctionDecl *FNTarget = nullptr;
17045 (void)Target->hasBody(FNTarget);
17046 Target = const_cast<CXXConstructorDecl*>(
17047 cast_or_null<CXXConstructorDecl>(FNTarget));
17050 CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
17051 // Avoid dereferencing a null pointer here.
17052 *TCanonical = Target? Target->getCanonicalDecl() : nullptr;
17054 if (!Current.insert(Canonical).second)
17057 // We know that beyond here, we aren't chaining into a cycle.
17058 if (!Target || !Target->isDelegatingConstructor() ||
17059 Target->isInvalidDecl() || Valid.count(TCanonical)) {
17060 Valid.insert(Current.begin(), Current.end());
17062 // We've hit a cycle.
17063 } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
17064 Current.count(TCanonical)) {
17065 // If we haven't diagnosed this cycle yet, do so now.
17066 if (!Invalid.count(TCanonical)) {
17067 S.Diag((*Ctor->init_begin())->getSourceLocation(),
17068 diag::warn_delegating_ctor_cycle)
17071 // Don't add a note for a function delegating directly to itself.
17072 if (TCanonical != Canonical)
17073 S.Diag(Target->getLocation(), diag::note_it_delegates_to);
17075 CXXConstructorDecl *C = Target;
17076 while (C->getCanonicalDecl() != Canonical) {
17077 const FunctionDecl *FNTarget = nullptr;
17078 (void)C->getTargetConstructor()->hasBody(FNTarget);
17079 assert(FNTarget && "Ctor cycle through bodiless function");
17081 C = const_cast<CXXConstructorDecl*>(
17082 cast<CXXConstructorDecl>(FNTarget));
17083 S.Diag(C->getLocation(), diag::note_which_delegates_to);
17087 Invalid.insert(Current.begin(), Current.end());
17090 DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
17095 void Sema::CheckDelegatingCtorCycles() {
17096 llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
17098 for (DelegatingCtorDeclsType::iterator
17099 I = DelegatingCtorDecls.begin(ExternalSource),
17100 E = DelegatingCtorDecls.end();
17102 DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
17104 for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
17105 (*CI)->setInvalidDecl();
17109 /// AST visitor that finds references to the 'this' expression.
17110 class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
17114 explicit FindCXXThisExpr(Sema &S) : S(S) { }
17116 bool VisitCXXThisExpr(CXXThisExpr *E) {
17117 S.Diag(E->getLocation(), diag::err_this_static_member_func)
17118 << E->isImplicit();
17124 bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
17125 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17129 TypeLoc TL = TSInfo->getTypeLoc();
17130 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17134 // C++11 [expr.prim.general]p3:
17135 // [The expression this] shall not appear before the optional
17136 // cv-qualifier-seq and it shall not appear within the declaration of a
17137 // static member function (although its type and value category are defined
17138 // within a static member function as they are within a non-static member
17139 // function). [ Note: this is because declaration matching does not occur
17140 // until the complete declarator is known. - end note ]
17141 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17142 FindCXXThisExpr Finder(*this);
17144 // If the return type came after the cv-qualifier-seq, check it now.
17145 if (Proto->hasTrailingReturn() &&
17146 !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc()))
17149 // Check the exception specification.
17150 if (checkThisInStaticMemberFunctionExceptionSpec(Method))
17153 // Check the trailing requires clause
17154 if (Expr *E = Method->getTrailingRequiresClause())
17155 if (!Finder.TraverseStmt(E))
17158 return checkThisInStaticMemberFunctionAttributes(Method);
17161 bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
17162 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
17166 TypeLoc TL = TSInfo->getTypeLoc();
17167 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
17171 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
17172 FindCXXThisExpr Finder(*this);
17174 switch (Proto->getExceptionSpecType()) {
17176 case EST_Uninstantiated:
17177 case EST_Unevaluated:
17178 case EST_BasicNoexcept:
17180 case EST_DynamicNone:
17185 case EST_DependentNoexcept:
17186 case EST_NoexceptFalse:
17187 case EST_NoexceptTrue:
17188 if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
17193 for (const auto &E : Proto->exceptions()) {
17194 if (!Finder.TraverseType(E))
17203 bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
17204 FindCXXThisExpr Finder(*this);
17206 // Check attributes.
17207 for (const auto *A : Method->attrs()) {
17208 // FIXME: This should be emitted by tblgen.
17209 Expr *Arg = nullptr;
17210 ArrayRef<Expr *> Args;
17211 if (const auto *G = dyn_cast<GuardedByAttr>(A))
17213 else if (const auto *G = dyn_cast<PtGuardedByAttr>(A))
17215 else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A))
17216 Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size());
17217 else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A))
17218 Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size());
17219 else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) {
17220 Arg = ETLF->getSuccessValue();
17221 Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size());
17222 } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) {
17223 Arg = STLF->getSuccessValue();
17224 Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size());
17225 } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A))
17226 Arg = LR->getArg();
17227 else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A))
17228 Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size());
17229 else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A))
17230 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17231 else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A))
17232 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17233 else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A))
17234 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
17235 else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A))
17236 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
17238 if (Arg && !Finder.TraverseStmt(Arg))
17241 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
17242 if (!Finder.TraverseStmt(Args[I]))
17250 void Sema::checkExceptionSpecification(
17251 bool IsTopLevel, ExceptionSpecificationType EST,
17252 ArrayRef<ParsedType> DynamicExceptions,
17253 ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr,
17254 SmallVectorImpl<QualType> &Exceptions,
17255 FunctionProtoType::ExceptionSpecInfo &ESI) {
17256 Exceptions.clear();
17258 if (EST == EST_Dynamic) {
17259 Exceptions.reserve(DynamicExceptions.size());
17260 for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
17261 // FIXME: Preserve type source info.
17262 QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
17265 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
17266 collectUnexpandedParameterPacks(ET, Unexpanded);
17267 if (!Unexpanded.empty()) {
17268 DiagnoseUnexpandedParameterPacks(
17269 DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType,
17275 // Check that the type is valid for an exception spec, and
17277 if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
17278 Exceptions.push_back(ET);
17280 ESI.Exceptions = Exceptions;
17284 if (isComputedNoexcept(EST)) {
17285 assert((NoexceptExpr->isTypeDependent() ||
17286 NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
17288 "Parser should have made sure that the expression is boolean");
17289 if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
17290 ESI.Type = EST_BasicNoexcept;
17294 ESI.NoexceptExpr = NoexceptExpr;
17299 void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
17300 ExceptionSpecificationType EST,
17301 SourceRange SpecificationRange,
17302 ArrayRef<ParsedType> DynamicExceptions,
17303 ArrayRef<SourceRange> DynamicExceptionRanges,
17304 Expr *NoexceptExpr) {
17308 // Dig out the method we're referring to.
17309 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
17310 MethodD = FunTmpl->getTemplatedDecl();
17312 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD);
17316 // Check the exception specification.
17317 llvm::SmallVector<QualType, 4> Exceptions;
17318 FunctionProtoType::ExceptionSpecInfo ESI;
17319 checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions,
17320 DynamicExceptionRanges, NoexceptExpr, Exceptions,
17323 // Update the exception specification on the function type.
17324 Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true);
17326 if (Method->isStatic())
17327 checkThisInStaticMemberFunctionExceptionSpec(Method);
17329 if (Method->isVirtual()) {
17330 // Check overrides, which we previously had to delay.
17331 for (const CXXMethodDecl *O : Method->overridden_methods())
17332 CheckOverridingFunctionExceptionSpec(Method, O);
17336 /// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class.
17338 MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record,
17339 SourceLocation DeclStart, Declarator &D,
17341 InClassInitStyle InitStyle,
17342 AccessSpecifier AS,
17343 const ParsedAttr &MSPropertyAttr) {
17344 IdentifierInfo *II = D.getIdentifier();
17346 Diag(DeclStart, diag::err_anonymous_property);
17349 SourceLocation Loc = D.getIdentifierLoc();
17351 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
17352 QualType T = TInfo->getType();
17353 if (getLangOpts().CPlusPlus) {
17354 CheckExtraCXXDefaultArguments(D);
17356 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
17357 UPPC_DataMemberType)) {
17358 D.setInvalidType();
17360 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
17364 DiagnoseFunctionSpecifiers(D.getDeclSpec());
17366 if (D.getDeclSpec().isInlineSpecified())
17367 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
17368 << getLangOpts().CPlusPlus17;
17369 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
17370 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
17371 diag::err_invalid_thread)
17372 << DeclSpec::getSpecifierName(TSCS);
17374 // Check to see if this name was declared as a member previously
17375 NamedDecl *PrevDecl = nullptr;
17376 LookupResult Previous(*this, II, Loc, LookupMemberName,
17377 ForVisibleRedeclaration);
17378 LookupName(Previous, S);
17379 switch (Previous.getResultKind()) {
17380 case LookupResult::Found:
17381 case LookupResult::FoundUnresolvedValue:
17382 PrevDecl = Previous.getAsSingle<NamedDecl>();
17385 case LookupResult::FoundOverloaded:
17386 PrevDecl = Previous.getRepresentativeDecl();
17389 case LookupResult::NotFound:
17390 case LookupResult::NotFoundInCurrentInstantiation:
17391 case LookupResult::Ambiguous:
17395 if (PrevDecl && PrevDecl->isTemplateParameter()) {
17396 // Maybe we will complain about the shadowed template parameter.
17397 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
17398 // Just pretend that we didn't see the previous declaration.
17399 PrevDecl = nullptr;
17402 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
17403 PrevDecl = nullptr;
17405 SourceLocation TSSL = D.getBeginLoc();
17406 MSPropertyDecl *NewPD =
17407 MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL,
17408 MSPropertyAttr.getPropertyDataGetter(),
17409 MSPropertyAttr.getPropertyDataSetter());
17410 ProcessDeclAttributes(TUScope, NewPD, D);
17411 NewPD->setAccess(AS);
17413 if (NewPD->isInvalidDecl())
17414 Record->setInvalidDecl();
17416 if (D.getDeclSpec().isModulePrivateSpecified())
17417 NewPD->setModulePrivate();
17419 if (NewPD->isInvalidDecl() && PrevDecl) {
17420 // Don't introduce NewFD into scope; there's already something
17421 // with the same name in the same scope.
17423 PushOnScopeChains(NewPD, S);
17425 Record->addDecl(NewPD);
17430 void Sema::ActOnStartFunctionDeclarationDeclarator(
17431 Declarator &Declarator, unsigned TemplateParameterDepth) {
17432 auto &Info = InventedParameterInfos.emplace_back();
17433 TemplateParameterList *ExplicitParams = nullptr;
17434 ArrayRef<TemplateParameterList *> ExplicitLists =
17435 Declarator.getTemplateParameterLists();
17436 if (!ExplicitLists.empty()) {
17437 bool IsMemberSpecialization, IsInvalid;
17438 ExplicitParams = MatchTemplateParametersToScopeSpecifier(
17439 Declarator.getBeginLoc(), Declarator.getIdentifierLoc(),
17440 Declarator.getCXXScopeSpec(), /*TemplateId=*/nullptr,
17441 ExplicitLists, /*IsFriend=*/false, IsMemberSpecialization, IsInvalid,
17442 /*SuppressDiagnostic=*/true);
17444 if (ExplicitParams) {
17445 Info.AutoTemplateParameterDepth = ExplicitParams->getDepth();
17446 for (NamedDecl *Param : *ExplicitParams)
17447 Info.TemplateParams.push_back(Param);
17448 Info.NumExplicitTemplateParams = ExplicitParams->size();
17450 Info.AutoTemplateParameterDepth = TemplateParameterDepth;
17451 Info.NumExplicitTemplateParams = 0;
17455 void Sema::ActOnFinishFunctionDeclarationDeclarator(Declarator &Declarator) {
17456 auto &FSI = InventedParameterInfos.back();
17457 if (FSI.TemplateParams.size() > FSI.NumExplicitTemplateParams) {
17458 if (FSI.NumExplicitTemplateParams != 0) {
17459 TemplateParameterList *ExplicitParams =
17460 Declarator.getTemplateParameterLists().back();
17461 Declarator.setInventedTemplateParameterList(
17462 TemplateParameterList::Create(
17463 Context, ExplicitParams->getTemplateLoc(),
17464 ExplicitParams->getLAngleLoc(), FSI.TemplateParams,
17465 ExplicitParams->getRAngleLoc(),
17466 ExplicitParams->getRequiresClause()));
17468 Declarator.setInventedTemplateParameterList(
17469 TemplateParameterList::Create(
17470 Context, SourceLocation(), SourceLocation(), FSI.TemplateParams,
17471 SourceLocation(), /*RequiresClause=*/nullptr));
17474 InventedParameterInfos.pop_back();