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::CalledExpr(Expr *E) {
221 if (!E || 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(E))
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->getAs<ReferenceType>()->getPointeeType();
1505 } else if (const PointerType *P = NewType->getAs<PointerType>()) {
1506 NewType = P->getPointeeType();
1507 OldType = OldType->getAs<PointerType>()->getPointeeType();
1508 } else if (const MemberPointerType *M = NewType->getAs<MemberPointerType>()) {
1509 NewType = M->getPointeeType();
1510 OldType = OldType->getAs<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 // CheckConstexprParameterTypes - Check whether a function's parameter types
1631 // are all literal types. If so, return true. If not, produce a suitable
1632 // diagnostic and return false.
1633 static bool CheckConstexprParameterTypes(Sema &SemaRef,
1634 const FunctionDecl *FD,
1635 Sema::CheckConstexprKind Kind) {
1636 unsigned ArgIndex = 0;
1637 const FunctionProtoType *FT = FD->getType()->getAs<FunctionProtoType>();
1638 for (FunctionProtoType::param_type_iterator i = FT->param_type_begin(),
1639 e = FT->param_type_end();
1640 i != e; ++i, ++ArgIndex) {
1641 const ParmVarDecl *PD = FD->getParamDecl(ArgIndex);
1642 SourceLocation ParamLoc = PD->getLocation();
1643 if (CheckLiteralType(SemaRef, Kind, ParamLoc, *i,
1644 diag::err_constexpr_non_literal_param, ArgIndex + 1,
1645 PD->getSourceRange(), isa<CXXConstructorDecl>(FD),
1652 /// Get diagnostic %select index for tag kind for
1653 /// record diagnostic message.
1654 /// WARNING: Indexes apply to particular diagnostics only!
1656 /// \returns diagnostic %select index.
1657 static unsigned getRecordDiagFromTagKind(TagTypeKind Tag) {
1659 case TTK_Struct: return 0;
1660 case TTK_Interface: return 1;
1661 case TTK_Class: return 2;
1662 default: llvm_unreachable("Invalid tag kind for record diagnostic!");
1666 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
1668 Sema::CheckConstexprKind Kind);
1670 // Check whether a function declaration satisfies the requirements of a
1671 // constexpr function definition or a constexpr constructor definition. If so,
1672 // return true. If not, produce appropriate diagnostics (unless asked not to by
1673 // Kind) and return false.
1675 // This implements C++11 [dcl.constexpr]p3,4, as amended by DR1360.
1676 bool Sema::CheckConstexprFunctionDefinition(const FunctionDecl *NewFD,
1677 CheckConstexprKind Kind) {
1678 const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
1679 if (MD && MD->isInstance()) {
1680 // C++11 [dcl.constexpr]p4:
1681 // The definition of a constexpr constructor shall satisfy the following
1683 // - the class shall not have any virtual base classes;
1685 // FIXME: This only applies to constructors and destructors, not arbitrary
1686 // member functions.
1687 const CXXRecordDecl *RD = MD->getParent();
1688 if (RD->getNumVBases()) {
1689 if (Kind == CheckConstexprKind::CheckValid)
1692 Diag(NewFD->getLocation(), diag::err_constexpr_virtual_base)
1693 << isa<CXXConstructorDecl>(NewFD)
1694 << getRecordDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
1695 for (const auto &I : RD->vbases())
1696 Diag(I.getBeginLoc(), diag::note_constexpr_virtual_base_here)
1697 << I.getSourceRange();
1702 if (!isa<CXXConstructorDecl>(NewFD)) {
1703 // C++11 [dcl.constexpr]p3:
1704 // The definition of a constexpr function shall satisfy the following
1706 // - it shall not be virtual; (removed in C++20)
1707 const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD);
1708 if (Method && Method->isVirtual()) {
1709 if (getLangOpts().CPlusPlus2a) {
1710 if (Kind == CheckConstexprKind::Diagnose)
1711 Diag(Method->getLocation(), diag::warn_cxx17_compat_constexpr_virtual);
1713 if (Kind == CheckConstexprKind::CheckValid)
1716 Method = Method->getCanonicalDecl();
1717 Diag(Method->getLocation(), diag::err_constexpr_virtual);
1719 // If it's not obvious why this function is virtual, find an overridden
1720 // function which uses the 'virtual' keyword.
1721 const CXXMethodDecl *WrittenVirtual = Method;
1722 while (!WrittenVirtual->isVirtualAsWritten())
1723 WrittenVirtual = *WrittenVirtual->begin_overridden_methods();
1724 if (WrittenVirtual != Method)
1725 Diag(WrittenVirtual->getLocation(),
1726 diag::note_overridden_virtual_function);
1731 // - its return type shall be a literal type;
1732 QualType RT = NewFD->getReturnType();
1733 if (CheckLiteralType(*this, Kind, NewFD->getLocation(), RT,
1734 diag::err_constexpr_non_literal_return,
1735 NewFD->isConsteval()))
1739 if (auto *Dtor = dyn_cast<CXXDestructorDecl>(NewFD)) {
1740 // A destructor can be constexpr only if the defaulted destructor could be;
1741 // we don't need to check the members and bases if we already know they all
1742 // have constexpr destructors.
1743 if (!Dtor->getParent()->defaultedDestructorIsConstexpr()) {
1744 if (Kind == CheckConstexprKind::CheckValid)
1746 if (!CheckConstexprDestructorSubobjects(*this, Dtor, Kind))
1751 // - each of its parameter types shall be a literal type;
1752 if (!CheckConstexprParameterTypes(*this, NewFD, Kind))
1755 Stmt *Body = NewFD->getBody();
1757 "CheckConstexprFunctionDefinition called on function with no body");
1758 return CheckConstexprFunctionBody(*this, NewFD, Body, Kind);
1761 /// Check the given declaration statement is legal within a constexpr function
1762 /// body. C++11 [dcl.constexpr]p3,p4, and C++1y [dcl.constexpr]p3.
1764 /// \return true if the body is OK (maybe only as an extension), false if we
1765 /// have diagnosed a problem.
1766 static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
1767 DeclStmt *DS, SourceLocation &Cxx1yLoc,
1768 Sema::CheckConstexprKind Kind) {
1769 // C++11 [dcl.constexpr]p3 and p4:
1770 // The definition of a constexpr function(p3) or constructor(p4) [...] shall
1772 for (const auto *DclIt : DS->decls()) {
1773 switch (DclIt->getKind()) {
1774 case Decl::StaticAssert:
1776 case Decl::UsingShadow:
1777 case Decl::UsingDirective:
1778 case Decl::UnresolvedUsingTypename:
1779 case Decl::UnresolvedUsingValue:
1780 // - static_assert-declarations
1781 // - using-declarations,
1782 // - using-directives,
1786 case Decl::TypeAlias: {
1787 // - typedef declarations and alias-declarations that do not define
1788 // classes or enumerations,
1789 const auto *TN = cast<TypedefNameDecl>(DclIt);
1790 if (TN->getUnderlyingType()->isVariablyModifiedType()) {
1791 // Don't allow variably-modified types in constexpr functions.
1792 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1793 TypeLoc TL = TN->getTypeSourceInfo()->getTypeLoc();
1794 SemaRef.Diag(TL.getBeginLoc(), diag::err_constexpr_vla)
1795 << TL.getSourceRange() << TL.getType()
1796 << isa<CXXConstructorDecl>(Dcl);
1804 case Decl::CXXRecord:
1805 // C++1y allows types to be defined, not just declared.
1806 if (cast<TagDecl>(DclIt)->isThisDeclarationADefinition()) {
1807 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1808 SemaRef.Diag(DS->getBeginLoc(),
1809 SemaRef.getLangOpts().CPlusPlus14
1810 ? diag::warn_cxx11_compat_constexpr_type_definition
1811 : diag::ext_constexpr_type_definition)
1812 << isa<CXXConstructorDecl>(Dcl);
1813 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1819 case Decl::EnumConstant:
1820 case Decl::IndirectField:
1822 // These can only appear with other declarations which are banned in
1823 // C++11 and permitted in C++1y, so ignore them.
1827 case Decl::Decomposition: {
1828 // C++1y [dcl.constexpr]p3 allows anything except:
1829 // a definition of a variable of non-literal type or of static or
1830 // thread storage duration or [before C++2a] for which no
1831 // initialization is performed.
1832 const auto *VD = cast<VarDecl>(DclIt);
1833 if (VD->isThisDeclarationADefinition()) {
1834 if (VD->isStaticLocal()) {
1835 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1836 SemaRef.Diag(VD->getLocation(),
1837 diag::err_constexpr_local_var_static)
1838 << isa<CXXConstructorDecl>(Dcl)
1839 << (VD->getTLSKind() == VarDecl::TLS_Dynamic);
1843 if (CheckLiteralType(SemaRef, Kind, VD->getLocation(), VD->getType(),
1844 diag::err_constexpr_local_var_non_literal_type,
1845 isa<CXXConstructorDecl>(Dcl)))
1847 if (!VD->getType()->isDependentType() &&
1848 !VD->hasInit() && !VD->isCXXForRangeDecl()) {
1849 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1852 SemaRef.getLangOpts().CPlusPlus2a
1853 ? diag::warn_cxx17_compat_constexpr_local_var_no_init
1854 : diag::ext_constexpr_local_var_no_init)
1855 << isa<CXXConstructorDecl>(Dcl);
1856 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
1862 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1863 SemaRef.Diag(VD->getLocation(),
1864 SemaRef.getLangOpts().CPlusPlus14
1865 ? diag::warn_cxx11_compat_constexpr_local_var
1866 : diag::ext_constexpr_local_var)
1867 << isa<CXXConstructorDecl>(Dcl);
1868 } else if (!SemaRef.getLangOpts().CPlusPlus14) {
1874 case Decl::NamespaceAlias:
1875 case Decl::Function:
1876 // These are disallowed in C++11 and permitted in C++1y. Allow them
1877 // everywhere as an extension.
1878 if (!Cxx1yLoc.isValid())
1879 Cxx1yLoc = DS->getBeginLoc();
1883 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1884 SemaRef.Diag(DS->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
1885 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
1894 /// Check that the given field is initialized within a constexpr constructor.
1896 /// \param Dcl The constexpr constructor being checked.
1897 /// \param Field The field being checked. This may be a member of an anonymous
1898 /// struct or union nested within the class being checked.
1899 /// \param Inits All declarations, including anonymous struct/union members and
1900 /// indirect members, for which any initialization was provided.
1901 /// \param Diagnosed Whether we've emitted the error message yet. Used to attach
1902 /// multiple notes for different members to the same error.
1903 /// \param Kind Whether we're diagnosing a constructor as written or determining
1904 /// whether the formal requirements are satisfied.
1905 /// \return \c false if we're checking for validity and the constructor does
1906 /// not satisfy the requirements on a constexpr constructor.
1907 static bool CheckConstexprCtorInitializer(Sema &SemaRef,
1908 const FunctionDecl *Dcl,
1910 llvm::SmallSet<Decl*, 16> &Inits,
1912 Sema::CheckConstexprKind Kind) {
1913 // In C++20 onwards, there's nothing to check for validity.
1914 if (Kind == Sema::CheckConstexprKind::CheckValid &&
1915 SemaRef.getLangOpts().CPlusPlus2a)
1918 if (Field->isInvalidDecl())
1921 if (Field->isUnnamedBitfield())
1924 // Anonymous unions with no variant members and empty anonymous structs do not
1925 // need to be explicitly initialized. FIXME: Anonymous structs that contain no
1926 // indirect fields don't need initializing.
1927 if (Field->isAnonymousStructOrUnion() &&
1928 (Field->getType()->isUnionType()
1929 ? !Field->getType()->getAsCXXRecordDecl()->hasVariantMembers()
1930 : Field->getType()->getAsCXXRecordDecl()->isEmpty()))
1933 if (!Inits.count(Field)) {
1934 if (Kind == Sema::CheckConstexprKind::Diagnose) {
1936 SemaRef.Diag(Dcl->getLocation(),
1937 SemaRef.getLangOpts().CPlusPlus2a
1938 ? diag::warn_cxx17_compat_constexpr_ctor_missing_init
1939 : diag::ext_constexpr_ctor_missing_init);
1942 SemaRef.Diag(Field->getLocation(),
1943 diag::note_constexpr_ctor_missing_init);
1944 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
1947 } else if (Field->isAnonymousStructOrUnion()) {
1948 const RecordDecl *RD = Field->getType()->castAs<RecordType>()->getDecl();
1949 for (auto *I : RD->fields())
1950 // If an anonymous union contains an anonymous struct of which any member
1951 // is initialized, all members must be initialized.
1952 if (!RD->isUnion() || Inits.count(I))
1953 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
1960 /// Check the provided statement is allowed in a constexpr function
1963 CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
1964 SmallVectorImpl<SourceLocation> &ReturnStmts,
1965 SourceLocation &Cxx1yLoc, SourceLocation &Cxx2aLoc,
1966 Sema::CheckConstexprKind Kind) {
1967 // - its function-body shall be [...] a compound-statement that contains only
1968 switch (S->getStmtClass()) {
1969 case Stmt::NullStmtClass:
1970 // - null statements,
1973 case Stmt::DeclStmtClass:
1974 // - static_assert-declarations
1975 // - using-declarations,
1976 // - using-directives,
1977 // - typedef declarations and alias-declarations that do not define
1978 // classes or enumerations,
1979 if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
1983 case Stmt::ReturnStmtClass:
1984 // - and exactly one return statement;
1985 if (isa<CXXConstructorDecl>(Dcl)) {
1986 // C++1y allows return statements in constexpr constructors.
1987 if (!Cxx1yLoc.isValid())
1988 Cxx1yLoc = S->getBeginLoc();
1992 ReturnStmts.push_back(S->getBeginLoc());
1995 case Stmt::CompoundStmtClass: {
1996 // C++1y allows compound-statements.
1997 if (!Cxx1yLoc.isValid())
1998 Cxx1yLoc = S->getBeginLoc();
2000 CompoundStmt *CompStmt = cast<CompoundStmt>(S);
2001 for (auto *BodyIt : CompStmt->body()) {
2002 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
2003 Cxx1yLoc, Cxx2aLoc, Kind))
2009 case Stmt::AttributedStmtClass:
2010 if (!Cxx1yLoc.isValid())
2011 Cxx1yLoc = S->getBeginLoc();
2014 case Stmt::IfStmtClass: {
2015 // C++1y allows if-statements.
2016 if (!Cxx1yLoc.isValid())
2017 Cxx1yLoc = S->getBeginLoc();
2019 IfStmt *If = cast<IfStmt>(S);
2020 if (!CheckConstexprFunctionStmt(SemaRef, Dcl, If->getThen(), ReturnStmts,
2021 Cxx1yLoc, Cxx2aLoc, Kind))
2023 if (If->getElse() &&
2024 !CheckConstexprFunctionStmt(SemaRef, Dcl, If->getElse(), ReturnStmts,
2025 Cxx1yLoc, Cxx2aLoc, Kind))
2030 case Stmt::WhileStmtClass:
2031 case Stmt::DoStmtClass:
2032 case Stmt::ForStmtClass:
2033 case Stmt::CXXForRangeStmtClass:
2034 case Stmt::ContinueStmtClass:
2035 // C++1y allows all of these. We don't allow them as extensions in C++11,
2036 // because they don't make sense without variable mutation.
2037 if (!SemaRef.getLangOpts().CPlusPlus14)
2039 if (!Cxx1yLoc.isValid())
2040 Cxx1yLoc = S->getBeginLoc();
2041 for (Stmt *SubStmt : S->children())
2043 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2044 Cxx1yLoc, Cxx2aLoc, Kind))
2048 case Stmt::SwitchStmtClass:
2049 case Stmt::CaseStmtClass:
2050 case Stmt::DefaultStmtClass:
2051 case Stmt::BreakStmtClass:
2052 // C++1y allows switch-statements, and since they don't need variable
2053 // mutation, we can reasonably allow them in C++11 as an extension.
2054 if (!Cxx1yLoc.isValid())
2055 Cxx1yLoc = S->getBeginLoc();
2056 for (Stmt *SubStmt : S->children())
2058 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2059 Cxx1yLoc, Cxx2aLoc, Kind))
2063 case Stmt::GCCAsmStmtClass:
2064 case Stmt::MSAsmStmtClass:
2065 // C++2a allows inline assembly statements.
2066 case Stmt::CXXTryStmtClass:
2067 if (Cxx2aLoc.isInvalid())
2068 Cxx2aLoc = S->getBeginLoc();
2069 for (Stmt *SubStmt : S->children()) {
2071 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2072 Cxx1yLoc, Cxx2aLoc, Kind))
2077 case Stmt::CXXCatchStmtClass:
2078 // Do not bother checking the language mode (already covered by the
2079 // try block check).
2080 if (!CheckConstexprFunctionStmt(SemaRef, Dcl,
2081 cast<CXXCatchStmt>(S)->getHandlerBlock(),
2082 ReturnStmts, Cxx1yLoc, Cxx2aLoc, Kind))
2090 // C++1y allows expression-statements.
2091 if (!Cxx1yLoc.isValid())
2092 Cxx1yLoc = S->getBeginLoc();
2096 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2097 SemaRef.Diag(S->getBeginLoc(), diag::err_constexpr_body_invalid_stmt)
2098 << isa<CXXConstructorDecl>(Dcl) << Dcl->isConsteval();
2103 /// Check the body for the given constexpr function declaration only contains
2104 /// the permitted types of statement. C++11 [dcl.constexpr]p3,p4.
2106 /// \return true if the body is OK, false if we have found or diagnosed a
2108 static bool CheckConstexprFunctionBody(Sema &SemaRef, const FunctionDecl *Dcl,
2110 Sema::CheckConstexprKind Kind) {
2111 SmallVector<SourceLocation, 4> ReturnStmts;
2113 if (isa<CXXTryStmt>(Body)) {
2114 // C++11 [dcl.constexpr]p3:
2115 // The definition of a constexpr function shall satisfy the following
2116 // constraints: [...]
2117 // - its function-body shall be = delete, = default, or a
2118 // compound-statement
2120 // C++11 [dcl.constexpr]p4:
2121 // In the definition of a constexpr constructor, [...]
2122 // - its function-body shall not be a function-try-block;
2124 // This restriction is lifted in C++2a, as long as inner statements also
2125 // apply the general constexpr rules.
2127 case Sema::CheckConstexprKind::CheckValid:
2128 if (!SemaRef.getLangOpts().CPlusPlus2a)
2132 case Sema::CheckConstexprKind::Diagnose:
2133 SemaRef.Diag(Body->getBeginLoc(),
2134 !SemaRef.getLangOpts().CPlusPlus2a
2135 ? diag::ext_constexpr_function_try_block_cxx2a
2136 : diag::warn_cxx17_compat_constexpr_function_try_block)
2137 << isa<CXXConstructorDecl>(Dcl);
2142 // - its function-body shall be [...] a compound-statement that contains only
2143 // [... list of cases ...]
2145 // Note that walking the children here is enough to properly check for
2146 // CompoundStmt and CXXTryStmt body.
2147 SourceLocation Cxx1yLoc, Cxx2aLoc;
2148 for (Stmt *SubStmt : Body->children()) {
2150 !CheckConstexprFunctionStmt(SemaRef, Dcl, SubStmt, ReturnStmts,
2151 Cxx1yLoc, Cxx2aLoc, Kind))
2155 if (Kind == Sema::CheckConstexprKind::CheckValid) {
2156 // If this is only valid as an extension, report that we don't satisfy the
2157 // constraints of the current language.
2158 if ((Cxx2aLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus2a) ||
2159 (Cxx1yLoc.isValid() && !SemaRef.getLangOpts().CPlusPlus17))
2161 } else if (Cxx2aLoc.isValid()) {
2162 SemaRef.Diag(Cxx2aLoc,
2163 SemaRef.getLangOpts().CPlusPlus2a
2164 ? diag::warn_cxx17_compat_constexpr_body_invalid_stmt
2165 : diag::ext_constexpr_body_invalid_stmt_cxx2a)
2166 << isa<CXXConstructorDecl>(Dcl);
2167 } else if (Cxx1yLoc.isValid()) {
2168 SemaRef.Diag(Cxx1yLoc,
2169 SemaRef.getLangOpts().CPlusPlus14
2170 ? diag::warn_cxx11_compat_constexpr_body_invalid_stmt
2171 : diag::ext_constexpr_body_invalid_stmt)
2172 << isa<CXXConstructorDecl>(Dcl);
2175 if (const CXXConstructorDecl *Constructor
2176 = dyn_cast<CXXConstructorDecl>(Dcl)) {
2177 const CXXRecordDecl *RD = Constructor->getParent();
2179 // - every non-variant non-static data member and base class sub-object
2180 // shall be initialized;
2182 // - if the class is a union having variant members, exactly one of them
2183 // shall be initialized;
2184 if (RD->isUnion()) {
2185 if (Constructor->getNumCtorInitializers() == 0 &&
2186 RD->hasVariantMembers()) {
2187 if (Kind == Sema::CheckConstexprKind::Diagnose) {
2190 SemaRef.getLangOpts().CPlusPlus2a
2191 ? diag::warn_cxx17_compat_constexpr_union_ctor_no_init
2192 : diag::ext_constexpr_union_ctor_no_init);
2193 } else if (!SemaRef.getLangOpts().CPlusPlus2a) {
2197 } else if (!Constructor->isDependentContext() &&
2198 !Constructor->isDelegatingConstructor()) {
2199 assert(RD->getNumVBases() == 0 && "constexpr ctor with virtual bases");
2201 // Skip detailed checking if we have enough initializers, and we would
2202 // allow at most one initializer per member.
2203 bool AnyAnonStructUnionMembers = false;
2204 unsigned Fields = 0;
2205 for (CXXRecordDecl::field_iterator I = RD->field_begin(),
2206 E = RD->field_end(); I != E; ++I, ++Fields) {
2207 if (I->isAnonymousStructOrUnion()) {
2208 AnyAnonStructUnionMembers = true;
2213 // - if the class is a union-like class, but is not a union, for each of
2214 // its anonymous union members having variant members, exactly one of
2215 // them shall be initialized;
2216 if (AnyAnonStructUnionMembers ||
2217 Constructor->getNumCtorInitializers() != RD->getNumBases() + Fields) {
2218 // Check initialization of non-static data members. Base classes are
2219 // always initialized so do not need to be checked. Dependent bases
2220 // might not have initializers in the member initializer list.
2221 llvm::SmallSet<Decl*, 16> Inits;
2222 for (const auto *I: Constructor->inits()) {
2223 if (FieldDecl *FD = I->getMember())
2225 else if (IndirectFieldDecl *ID = I->getIndirectMember())
2226 Inits.insert(ID->chain_begin(), ID->chain_end());
2229 bool Diagnosed = false;
2230 for (auto *I : RD->fields())
2231 if (!CheckConstexprCtorInitializer(SemaRef, Dcl, I, Inits, Diagnosed,
2237 if (ReturnStmts.empty()) {
2238 // C++1y doesn't require constexpr functions to contain a 'return'
2239 // statement. We still do, unless the return type might be void, because
2240 // otherwise if there's no return statement, the function cannot
2241 // be used in a core constant expression.
2242 bool OK = SemaRef.getLangOpts().CPlusPlus14 &&
2243 (Dcl->getReturnType()->isVoidType() ||
2244 Dcl->getReturnType()->isDependentType());
2246 case Sema::CheckConstexprKind::Diagnose:
2247 SemaRef.Diag(Dcl->getLocation(),
2248 OK ? diag::warn_cxx11_compat_constexpr_body_no_return
2249 : diag::err_constexpr_body_no_return)
2250 << Dcl->isConsteval();
2255 case Sema::CheckConstexprKind::CheckValid:
2256 // The formal requirements don't include this rule in C++14, even
2257 // though the "must be able to produce a constant expression" rules
2258 // still imply it in some cases.
2259 if (!SemaRef.getLangOpts().CPlusPlus14)
2263 } else if (ReturnStmts.size() > 1) {
2265 case Sema::CheckConstexprKind::Diagnose:
2268 SemaRef.getLangOpts().CPlusPlus14
2269 ? diag::warn_cxx11_compat_constexpr_body_multiple_return
2270 : diag::ext_constexpr_body_multiple_return);
2271 for (unsigned I = 0; I < ReturnStmts.size() - 1; ++I)
2272 SemaRef.Diag(ReturnStmts[I],
2273 diag::note_constexpr_body_previous_return);
2276 case Sema::CheckConstexprKind::CheckValid:
2277 if (!SemaRef.getLangOpts().CPlusPlus14)
2284 // C++11 [dcl.constexpr]p5:
2285 // if no function argument values exist such that the function invocation
2286 // substitution would produce a constant expression, the program is
2287 // ill-formed; no diagnostic required.
2288 // C++11 [dcl.constexpr]p3:
2289 // - every constructor call and implicit conversion used in initializing the
2290 // return value shall be one of those allowed in a constant expression.
2291 // C++11 [dcl.constexpr]p4:
2292 // - every constructor involved in initializing non-static data members and
2293 // base class sub-objects shall be a constexpr constructor.
2295 // Note that this rule is distinct from the "requirements for a constexpr
2296 // function", so is not checked in CheckValid mode.
2297 SmallVector<PartialDiagnosticAt, 8> Diags;
2298 if (Kind == Sema::CheckConstexprKind::Diagnose &&
2299 !Expr::isPotentialConstantExpr(Dcl, Diags)) {
2300 SemaRef.Diag(Dcl->getLocation(),
2301 diag::ext_constexpr_function_never_constant_expr)
2302 << isa<CXXConstructorDecl>(Dcl);
2303 for (size_t I = 0, N = Diags.size(); I != N; ++I)
2304 SemaRef.Diag(Diags[I].first, Diags[I].second);
2305 // Don't return false here: we allow this for compatibility in
2312 /// Get the class that is directly named by the current context. This is the
2313 /// class for which an unqualified-id in this scope could name a constructor
2316 /// If the scope specifier denotes a class, this will be that class.
2317 /// If the scope specifier is empty, this will be the class whose
2318 /// member-specification we are currently within. Otherwise, there
2319 /// is no such class.
2320 CXXRecordDecl *Sema::getCurrentClass(Scope *, const CXXScopeSpec *SS) {
2321 assert(getLangOpts().CPlusPlus && "No class names in C!");
2323 if (SS && SS->isInvalid())
2326 if (SS && SS->isNotEmpty()) {
2327 DeclContext *DC = computeDeclContext(*SS, true);
2328 return dyn_cast_or_null<CXXRecordDecl>(DC);
2331 return dyn_cast_or_null<CXXRecordDecl>(CurContext);
2334 /// isCurrentClassName - Determine whether the identifier II is the
2335 /// name of the class type currently being defined. In the case of
2336 /// nested classes, this will only return true if II is the name of
2337 /// the innermost class.
2338 bool Sema::isCurrentClassName(const IdentifierInfo &II, Scope *S,
2339 const CXXScopeSpec *SS) {
2340 CXXRecordDecl *CurDecl = getCurrentClass(S, SS);
2341 return CurDecl && &II == CurDecl->getIdentifier();
2344 /// Determine whether the identifier II is a typo for the name of
2345 /// the class type currently being defined. If so, update it to the identifier
2346 /// that should have been used.
2347 bool Sema::isCurrentClassNameTypo(IdentifierInfo *&II, const CXXScopeSpec *SS) {
2348 assert(getLangOpts().CPlusPlus && "No class names in C!");
2350 if (!getLangOpts().SpellChecking)
2353 CXXRecordDecl *CurDecl;
2354 if (SS && SS->isSet() && !SS->isInvalid()) {
2355 DeclContext *DC = computeDeclContext(*SS, true);
2356 CurDecl = dyn_cast_or_null<CXXRecordDecl>(DC);
2358 CurDecl = dyn_cast_or_null<CXXRecordDecl>(CurContext);
2360 if (CurDecl && CurDecl->getIdentifier() && II != CurDecl->getIdentifier() &&
2361 3 * II->getName().edit_distance(CurDecl->getIdentifier()->getName())
2362 < II->getLength()) {
2363 II = CurDecl->getIdentifier();
2370 /// Determine whether the given class is a base class of the given
2371 /// class, including looking at dependent bases.
2372 static bool findCircularInheritance(const CXXRecordDecl *Class,
2373 const CXXRecordDecl *Current) {
2374 SmallVector<const CXXRecordDecl*, 8> Queue;
2376 Class = Class->getCanonicalDecl();
2378 for (const auto &I : Current->bases()) {
2379 CXXRecordDecl *Base = I.getType()->getAsCXXRecordDecl();
2383 Base = Base->getDefinition();
2387 if (Base->getCanonicalDecl() == Class)
2390 Queue.push_back(Base);
2396 Current = Queue.pop_back_val();
2402 /// Check the validity of a C++ base class specifier.
2404 /// \returns a new CXXBaseSpecifier if well-formed, emits diagnostics
2405 /// and returns NULL otherwise.
2407 Sema::CheckBaseSpecifier(CXXRecordDecl *Class,
2408 SourceRange SpecifierRange,
2409 bool Virtual, AccessSpecifier Access,
2410 TypeSourceInfo *TInfo,
2411 SourceLocation EllipsisLoc) {
2412 QualType BaseType = TInfo->getType();
2414 // C++ [class.union]p1:
2415 // A union shall not have base classes.
2416 if (Class->isUnion()) {
2417 Diag(Class->getLocation(), diag::err_base_clause_on_union)
2422 if (EllipsisLoc.isValid() &&
2423 !TInfo->getType()->containsUnexpandedParameterPack()) {
2424 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
2425 << TInfo->getTypeLoc().getSourceRange();
2426 EllipsisLoc = SourceLocation();
2429 SourceLocation BaseLoc = TInfo->getTypeLoc().getBeginLoc();
2431 if (BaseType->isDependentType()) {
2432 // Make sure that we don't have circular inheritance among our dependent
2433 // bases. For non-dependent bases, the check for completeness below handles
2435 if (CXXRecordDecl *BaseDecl = BaseType->getAsCXXRecordDecl()) {
2436 if (BaseDecl->getCanonicalDecl() == Class->getCanonicalDecl() ||
2437 ((BaseDecl = BaseDecl->getDefinition()) &&
2438 findCircularInheritance(Class, BaseDecl))) {
2439 Diag(BaseLoc, diag::err_circular_inheritance)
2440 << BaseType << Context.getTypeDeclType(Class);
2442 if (BaseDecl->getCanonicalDecl() != Class->getCanonicalDecl())
2443 Diag(BaseDecl->getLocation(), diag::note_previous_decl)
2450 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2451 Class->getTagKind() == TTK_Class,
2452 Access, TInfo, EllipsisLoc);
2455 // Base specifiers must be record types.
2456 if (!BaseType->isRecordType()) {
2457 Diag(BaseLoc, diag::err_base_must_be_class) << SpecifierRange;
2461 // C++ [class.union]p1:
2462 // A union shall not be used as a base class.
2463 if (BaseType->isUnionType()) {
2464 Diag(BaseLoc, diag::err_union_as_base_class) << SpecifierRange;
2468 // For the MS ABI, propagate DLL attributes to base class templates.
2469 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2470 if (Attr *ClassAttr = getDLLAttr(Class)) {
2471 if (auto *BaseTemplate = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
2472 BaseType->getAsCXXRecordDecl())) {
2473 propagateDLLAttrToBaseClassTemplate(Class, ClassAttr, BaseTemplate,
2479 // C++ [class.derived]p2:
2480 // The class-name in a base-specifier shall not be an incompletely
2482 if (RequireCompleteType(BaseLoc, BaseType,
2483 diag::err_incomplete_base_class, SpecifierRange)) {
2484 Class->setInvalidDecl();
2488 // If the base class is polymorphic or isn't empty, the new one is/isn't, too.
2489 RecordDecl *BaseDecl = BaseType->castAs<RecordType>()->getDecl();
2490 assert(BaseDecl && "Record type has no declaration");
2491 BaseDecl = BaseDecl->getDefinition();
2492 assert(BaseDecl && "Base type is not incomplete, but has no definition");
2493 CXXRecordDecl *CXXBaseDecl = cast<CXXRecordDecl>(BaseDecl);
2494 assert(CXXBaseDecl && "Base type is not a C++ type");
2496 // Microsoft docs say:
2497 // "If a base-class has a code_seg attribute, derived classes must have the
2499 const auto *BaseCSA = CXXBaseDecl->getAttr<CodeSegAttr>();
2500 const auto *DerivedCSA = Class->getAttr<CodeSegAttr>();
2501 if ((DerivedCSA || BaseCSA) &&
2502 (!BaseCSA || !DerivedCSA || BaseCSA->getName() != DerivedCSA->getName())) {
2503 Diag(Class->getLocation(), diag::err_mismatched_code_seg_base);
2504 Diag(CXXBaseDecl->getLocation(), diag::note_base_class_specified_here)
2509 // A class which contains a flexible array member is not suitable for use as a
2511 // - If the layout determines that a base comes before another base,
2512 // the flexible array member would index into the subsequent base.
2513 // - If the layout determines that base comes before the derived class,
2514 // the flexible array member would index into the derived class.
2515 if (CXXBaseDecl->hasFlexibleArrayMember()) {
2516 Diag(BaseLoc, diag::err_base_class_has_flexible_array_member)
2517 << CXXBaseDecl->getDeclName();
2522 // If a class is marked final and it appears as a base-type-specifier in
2523 // base-clause, the program is ill-formed.
2524 if (FinalAttr *FA = CXXBaseDecl->getAttr<FinalAttr>()) {
2525 Diag(BaseLoc, diag::err_class_marked_final_used_as_base)
2526 << CXXBaseDecl->getDeclName()
2527 << FA->isSpelledAsSealed();
2528 Diag(CXXBaseDecl->getLocation(), diag::note_entity_declared_at)
2529 << CXXBaseDecl->getDeclName() << FA->getRange();
2533 if (BaseDecl->isInvalidDecl())
2534 Class->setInvalidDecl();
2536 // Create the base specifier.
2537 return new (Context) CXXBaseSpecifier(SpecifierRange, Virtual,
2538 Class->getTagKind() == TTK_Class,
2539 Access, TInfo, EllipsisLoc);
2542 /// ActOnBaseSpecifier - Parsed a base specifier. A base specifier is
2543 /// one entry in the base class list of a class specifier, for
2545 /// class foo : public bar, virtual private baz {
2546 /// 'public bar' and 'virtual private baz' are each base-specifiers.
2548 Sema::ActOnBaseSpecifier(Decl *classdecl, SourceRange SpecifierRange,
2549 ParsedAttributes &Attributes,
2550 bool Virtual, AccessSpecifier Access,
2551 ParsedType basetype, SourceLocation BaseLoc,
2552 SourceLocation EllipsisLoc) {
2556 AdjustDeclIfTemplate(classdecl);
2557 CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(classdecl);
2561 // We haven't yet attached the base specifiers.
2562 Class->setIsParsingBaseSpecifiers();
2564 // We do not support any C++11 attributes on base-specifiers yet.
2565 // Diagnose any attributes we see.
2566 for (const ParsedAttr &AL : Attributes) {
2567 if (AL.isInvalid() || AL.getKind() == ParsedAttr::IgnoredAttribute)
2569 Diag(AL.getLoc(), AL.getKind() == ParsedAttr::UnknownAttribute
2570 ? (unsigned)diag::warn_unknown_attribute_ignored
2571 : (unsigned)diag::err_base_specifier_attribute)
2575 TypeSourceInfo *TInfo = nullptr;
2576 GetTypeFromParser(basetype, &TInfo);
2578 if (EllipsisLoc.isInvalid() &&
2579 DiagnoseUnexpandedParameterPack(SpecifierRange.getBegin(), TInfo,
2583 if (CXXBaseSpecifier *BaseSpec = CheckBaseSpecifier(Class, SpecifierRange,
2584 Virtual, Access, TInfo,
2588 Class->setInvalidDecl();
2593 /// Use small set to collect indirect bases. As this is only used
2594 /// locally, there's no need to abstract the small size parameter.
2595 typedef llvm::SmallPtrSet<QualType, 4> IndirectBaseSet;
2597 /// Recursively add the bases of Type. Don't add Type itself.
2599 NoteIndirectBases(ASTContext &Context, IndirectBaseSet &Set,
2600 const QualType &Type)
2602 // Even though the incoming type is a base, it might not be
2603 // a class -- it could be a template parm, for instance.
2604 if (auto Rec = Type->getAs<RecordType>()) {
2605 auto Decl = Rec->getAsCXXRecordDecl();
2607 // Iterate over its bases.
2608 for (const auto &BaseSpec : Decl->bases()) {
2609 QualType Base = Context.getCanonicalType(BaseSpec.getType())
2610 .getUnqualifiedType();
2611 if (Set.insert(Base).second)
2612 // If we've not already seen it, recurse.
2613 NoteIndirectBases(Context, Set, Base);
2618 /// Performs the actual work of attaching the given base class
2619 /// specifiers to a C++ class.
2620 bool Sema::AttachBaseSpecifiers(CXXRecordDecl *Class,
2621 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2625 // Used to keep track of which base types we have already seen, so
2626 // that we can properly diagnose redundant direct base types. Note
2627 // that the key is always the unqualified canonical type of the base
2629 std::map<QualType, CXXBaseSpecifier*, QualTypeOrdering> KnownBaseTypes;
2631 // Used to track indirect bases so we can see if a direct base is
2633 IndirectBaseSet IndirectBaseTypes;
2635 // Copy non-redundant base specifiers into permanent storage.
2636 unsigned NumGoodBases = 0;
2637 bool Invalid = false;
2638 for (unsigned idx = 0; idx < Bases.size(); ++idx) {
2639 QualType NewBaseType
2640 = Context.getCanonicalType(Bases[idx]->getType());
2641 NewBaseType = NewBaseType.getLocalUnqualifiedType();
2643 CXXBaseSpecifier *&KnownBase = KnownBaseTypes[NewBaseType];
2645 // C++ [class.mi]p3:
2646 // A class shall not be specified as a direct base class of a
2647 // derived class more than once.
2648 Diag(Bases[idx]->getBeginLoc(), diag::err_duplicate_base_class)
2649 << KnownBase->getType() << Bases[idx]->getSourceRange();
2651 // Delete the duplicate base class specifier; we're going to
2652 // overwrite its pointer later.
2653 Context.Deallocate(Bases[idx]);
2657 // Okay, add this new base class.
2658 KnownBase = Bases[idx];
2659 Bases[NumGoodBases++] = Bases[idx];
2661 // Note this base's direct & indirect bases, if there could be ambiguity.
2662 if (Bases.size() > 1)
2663 NoteIndirectBases(Context, IndirectBaseTypes, NewBaseType);
2665 if (const RecordType *Record = NewBaseType->getAs<RecordType>()) {
2666 const CXXRecordDecl *RD = cast<CXXRecordDecl>(Record->getDecl());
2667 if (Class->isInterface() &&
2668 (!RD->isInterfaceLike() ||
2669 KnownBase->getAccessSpecifier() != AS_public)) {
2670 // The Microsoft extension __interface does not permit bases that
2671 // are not themselves public interfaces.
2672 Diag(KnownBase->getBeginLoc(), diag::err_invalid_base_in_interface)
2673 << getRecordDiagFromTagKind(RD->getTagKind()) << RD
2674 << RD->getSourceRange();
2677 if (RD->hasAttr<WeakAttr>())
2678 Class->addAttr(WeakAttr::CreateImplicit(Context));
2683 // Attach the remaining base class specifiers to the derived class.
2684 Class->setBases(Bases.data(), NumGoodBases);
2686 // Check that the only base classes that are duplicate are virtual.
2687 for (unsigned idx = 0; idx < NumGoodBases; ++idx) {
2688 // Check whether this direct base is inaccessible due to ambiguity.
2689 QualType BaseType = Bases[idx]->getType();
2691 // Skip all dependent types in templates being used as base specifiers.
2692 // Checks below assume that the base specifier is a CXXRecord.
2693 if (BaseType->isDependentType())
2696 CanQualType CanonicalBase = Context.getCanonicalType(BaseType)
2697 .getUnqualifiedType();
2699 if (IndirectBaseTypes.count(CanonicalBase)) {
2700 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2701 /*DetectVirtual=*/true);
2703 = Class->isDerivedFrom(CanonicalBase->getAsCXXRecordDecl(), Paths);
2707 if (Paths.isAmbiguous(CanonicalBase))
2708 Diag(Bases[idx]->getBeginLoc(), diag::warn_inaccessible_base_class)
2709 << BaseType << getAmbiguousPathsDisplayString(Paths)
2710 << Bases[idx]->getSourceRange();
2712 assert(Bases[idx]->isVirtual());
2715 // Delete the base class specifier, since its data has been copied
2716 // into the CXXRecordDecl.
2717 Context.Deallocate(Bases[idx]);
2723 /// ActOnBaseSpecifiers - Attach the given base specifiers to the
2724 /// class, after checking whether there are any duplicate base
2726 void Sema::ActOnBaseSpecifiers(Decl *ClassDecl,
2727 MutableArrayRef<CXXBaseSpecifier *> Bases) {
2728 if (!ClassDecl || Bases.empty())
2731 AdjustDeclIfTemplate(ClassDecl);
2732 AttachBaseSpecifiers(cast<CXXRecordDecl>(ClassDecl), Bases);
2735 /// Determine whether the type \p Derived is a C++ class that is
2736 /// derived from the type \p Base.
2737 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base) {
2738 if (!getLangOpts().CPlusPlus)
2741 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2745 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2749 // If either the base or the derived type is invalid, don't try to
2750 // check whether one is derived from the other.
2751 if (BaseRD->isInvalidDecl() || DerivedRD->isInvalidDecl())
2754 // FIXME: In a modules build, do we need the entire path to be visible for us
2755 // to be able to use the inheritance relationship?
2756 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2759 return DerivedRD->isDerivedFrom(BaseRD);
2762 /// Determine whether the type \p Derived is a C++ class that is
2763 /// derived from the type \p Base.
2764 bool Sema::IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base,
2765 CXXBasePaths &Paths) {
2766 if (!getLangOpts().CPlusPlus)
2769 CXXRecordDecl *DerivedRD = Derived->getAsCXXRecordDecl();
2773 CXXRecordDecl *BaseRD = Base->getAsCXXRecordDecl();
2777 if (!isCompleteType(Loc, Derived) && !DerivedRD->isBeingDefined())
2780 return DerivedRD->isDerivedFrom(BaseRD, Paths);
2783 static void BuildBasePathArray(const CXXBasePath &Path,
2784 CXXCastPath &BasePathArray) {
2785 // We first go backward and check if we have a virtual base.
2786 // FIXME: It would be better if CXXBasePath had the base specifier for
2787 // the nearest virtual base.
2789 for (unsigned I = Path.size(); I != 0; --I) {
2790 if (Path[I - 1].Base->isVirtual()) {
2796 // Now add all bases.
2797 for (unsigned I = Start, E = Path.size(); I != E; ++I)
2798 BasePathArray.push_back(const_cast<CXXBaseSpecifier*>(Path[I].Base));
2802 void Sema::BuildBasePathArray(const CXXBasePaths &Paths,
2803 CXXCastPath &BasePathArray) {
2804 assert(BasePathArray.empty() && "Base path array must be empty!");
2805 assert(Paths.isRecordingPaths() && "Must record paths!");
2806 return ::BuildBasePathArray(Paths.front(), BasePathArray);
2808 /// CheckDerivedToBaseConversion - Check whether the Derived-to-Base
2809 /// conversion (where Derived and Base are class types) is
2810 /// well-formed, meaning that the conversion is unambiguous (and
2811 /// that all of the base classes are accessible). Returns true
2812 /// and emits a diagnostic if the code is ill-formed, returns false
2813 /// otherwise. Loc is the location where this routine should point to
2814 /// if there is an error, and Range is the source range to highlight
2815 /// if there is an error.
2817 /// If either InaccessibleBaseID or AmbigiousBaseConvID are 0, then the
2818 /// diagnostic for the respective type of error will be suppressed, but the
2819 /// check for ill-formed code will still be performed.
2821 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2822 unsigned InaccessibleBaseID,
2823 unsigned AmbigiousBaseConvID,
2824 SourceLocation Loc, SourceRange Range,
2825 DeclarationName Name,
2826 CXXCastPath *BasePath,
2827 bool IgnoreAccess) {
2828 // First, determine whether the path from Derived to Base is
2829 // ambiguous. This is slightly more expensive than checking whether
2830 // the Derived to Base conversion exists, because here we need to
2831 // explore multiple paths to determine if there is an ambiguity.
2832 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
2833 /*DetectVirtual=*/false);
2834 bool DerivationOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2835 if (!DerivationOkay)
2838 const CXXBasePath *Path = nullptr;
2839 if (!Paths.isAmbiguous(Context.getCanonicalType(Base).getUnqualifiedType()))
2840 Path = &Paths.front();
2842 // For MSVC compatibility, check if Derived directly inherits from Base. Clang
2843 // warns about this hierarchy under -Winaccessible-base, but MSVC allows the
2844 // user to access such bases.
2845 if (!Path && getLangOpts().MSVCCompat) {
2846 for (const CXXBasePath &PossiblePath : Paths) {
2847 if (PossiblePath.size() == 1) {
2848 Path = &PossiblePath;
2849 if (AmbigiousBaseConvID)
2850 Diag(Loc, diag::ext_ms_ambiguous_direct_base)
2851 << Base << Derived << Range;
2858 if (!IgnoreAccess) {
2859 // Check that the base class can be accessed.
2861 CheckBaseClassAccess(Loc, Base, Derived, *Path, InaccessibleBaseID)) {
2862 case AR_inaccessible:
2871 // Build a base path if necessary.
2873 ::BuildBasePathArray(*Path, *BasePath);
2877 if (AmbigiousBaseConvID) {
2878 // We know that the derived-to-base conversion is ambiguous, and
2879 // we're going to produce a diagnostic. Perform the derived-to-base
2880 // search just one more time to compute all of the possible paths so
2881 // that we can print them out. This is more expensive than any of
2882 // the previous derived-to-base checks we've done, but at this point
2883 // performance isn't as much of an issue.
2885 Paths.setRecordingPaths(true);
2886 bool StillOkay = IsDerivedFrom(Loc, Derived, Base, Paths);
2887 assert(StillOkay && "Can only be used with a derived-to-base conversion");
2890 // Build up a textual representation of the ambiguous paths, e.g.,
2891 // D -> B -> A, that will be used to illustrate the ambiguous
2892 // conversions in the diagnostic. We only print one of the paths
2893 // to each base class subobject.
2894 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths);
2896 Diag(Loc, AmbigiousBaseConvID)
2897 << Derived << Base << PathDisplayStr << Range << Name;
2903 Sema::CheckDerivedToBaseConversion(QualType Derived, QualType Base,
2904 SourceLocation Loc, SourceRange Range,
2905 CXXCastPath *BasePath,
2906 bool IgnoreAccess) {
2907 return CheckDerivedToBaseConversion(
2908 Derived, Base, diag::err_upcast_to_inaccessible_base,
2909 diag::err_ambiguous_derived_to_base_conv, Loc, Range, DeclarationName(),
2910 BasePath, IgnoreAccess);
2914 /// Builds a string representing ambiguous paths from a
2915 /// specific derived class to different subobjects of the same base
2918 /// This function builds a string that can be used in error messages
2919 /// to show the different paths that one can take through the
2920 /// inheritance hierarchy to go from the derived class to different
2921 /// subobjects of a base class. The result looks something like this:
2923 /// struct D -> struct B -> struct A
2924 /// struct D -> struct C -> struct A
2926 std::string Sema::getAmbiguousPathsDisplayString(CXXBasePaths &Paths) {
2927 std::string PathDisplayStr;
2928 std::set<unsigned> DisplayedPaths;
2929 for (CXXBasePaths::paths_iterator Path = Paths.begin();
2930 Path != Paths.end(); ++Path) {
2931 if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
2932 // We haven't displayed a path to this particular base
2933 // class subobject yet.
2934 PathDisplayStr += "\n ";
2935 PathDisplayStr += Context.getTypeDeclType(Paths.getOrigin()).getAsString();
2936 for (CXXBasePath::const_iterator Element = Path->begin();
2937 Element != Path->end(); ++Element)
2938 PathDisplayStr += " -> " + Element->Base->getType().getAsString();
2942 return PathDisplayStr;
2945 //===----------------------------------------------------------------------===//
2946 // C++ class member Handling
2947 //===----------------------------------------------------------------------===//
2949 /// ActOnAccessSpecifier - Parsed an access specifier followed by a colon.
2950 bool Sema::ActOnAccessSpecifier(AccessSpecifier Access, SourceLocation ASLoc,
2951 SourceLocation ColonLoc,
2952 const ParsedAttributesView &Attrs) {
2953 assert(Access != AS_none && "Invalid kind for syntactic access specifier!");
2954 AccessSpecDecl *ASDecl = AccessSpecDecl::Create(Context, Access, CurContext,
2956 CurContext->addHiddenDecl(ASDecl);
2957 return ProcessAccessDeclAttributeList(ASDecl, Attrs);
2960 /// CheckOverrideControl - Check C++11 override control semantics.
2961 void Sema::CheckOverrideControl(NamedDecl *D) {
2962 if (D->isInvalidDecl())
2965 // We only care about "override" and "final" declarations.
2966 if (!D->hasAttr<OverrideAttr>() && !D->hasAttr<FinalAttr>())
2969 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
2971 // We can't check dependent instance methods.
2972 if (MD && MD->isInstance() &&
2973 (MD->getParent()->hasAnyDependentBases() ||
2974 MD->getType()->isDependentType()))
2977 if (MD && !MD->isVirtual()) {
2978 // If we have a non-virtual method, check if if hides a virtual method.
2979 // (In that case, it's most likely the method has the wrong type.)
2980 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
2981 FindHiddenVirtualMethods(MD, OverloadedMethods);
2983 if (!OverloadedMethods.empty()) {
2984 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
2985 Diag(OA->getLocation(),
2986 diag::override_keyword_hides_virtual_member_function)
2987 << "override" << (OverloadedMethods.size() > 1);
2988 } else if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
2989 Diag(FA->getLocation(),
2990 diag::override_keyword_hides_virtual_member_function)
2991 << (FA->isSpelledAsSealed() ? "sealed" : "final")
2992 << (OverloadedMethods.size() > 1);
2994 NoteHiddenVirtualMethods(MD, OverloadedMethods);
2995 MD->setInvalidDecl();
2998 // Fall through into the general case diagnostic.
2999 // FIXME: We might want to attempt typo correction here.
3002 if (!MD || !MD->isVirtual()) {
3003 if (OverrideAttr *OA = D->getAttr<OverrideAttr>()) {
3004 Diag(OA->getLocation(),
3005 diag::override_keyword_only_allowed_on_virtual_member_functions)
3006 << "override" << FixItHint::CreateRemoval(OA->getLocation());
3007 D->dropAttr<OverrideAttr>();
3009 if (FinalAttr *FA = D->getAttr<FinalAttr>()) {
3010 Diag(FA->getLocation(),
3011 diag::override_keyword_only_allowed_on_virtual_member_functions)
3012 << (FA->isSpelledAsSealed() ? "sealed" : "final")
3013 << FixItHint::CreateRemoval(FA->getLocation());
3014 D->dropAttr<FinalAttr>();
3019 // C++11 [class.virtual]p5:
3020 // If a function is marked with the virt-specifier override and
3021 // does not override a member function of a base class, the program is
3023 bool HasOverriddenMethods = MD->size_overridden_methods() != 0;
3024 if (MD->hasAttr<OverrideAttr>() && !HasOverriddenMethods)
3025 Diag(MD->getLocation(), diag::err_function_marked_override_not_overriding)
3026 << MD->getDeclName();
3029 void Sema::DiagnoseAbsenceOfOverrideControl(NamedDecl *D) {
3030 if (D->isInvalidDecl() || D->hasAttr<OverrideAttr>())
3032 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D);
3033 if (!MD || MD->isImplicit() || MD->hasAttr<FinalAttr>())
3036 SourceLocation Loc = MD->getLocation();
3037 SourceLocation SpellingLoc = Loc;
3038 if (getSourceManager().isMacroArgExpansion(Loc))
3039 SpellingLoc = getSourceManager().getImmediateExpansionRange(Loc).getBegin();
3040 SpellingLoc = getSourceManager().getSpellingLoc(SpellingLoc);
3041 if (SpellingLoc.isValid() && getSourceManager().isInSystemHeader(SpellingLoc))
3044 if (MD->size_overridden_methods() > 0) {
3045 unsigned DiagID = isa<CXXDestructorDecl>(MD)
3046 ? diag::warn_destructor_marked_not_override_overriding
3047 : diag::warn_function_marked_not_override_overriding;
3048 Diag(MD->getLocation(), DiagID) << MD->getDeclName();
3049 const CXXMethodDecl *OMD = *MD->begin_overridden_methods();
3050 Diag(OMD->getLocation(), diag::note_overridden_virtual_function);
3054 /// CheckIfOverriddenFunctionIsMarkedFinal - Checks whether a virtual member
3055 /// function overrides a virtual member function marked 'final', according to
3056 /// C++11 [class.virtual]p4.
3057 bool Sema::CheckIfOverriddenFunctionIsMarkedFinal(const CXXMethodDecl *New,
3058 const CXXMethodDecl *Old) {
3059 FinalAttr *FA = Old->getAttr<FinalAttr>();
3063 Diag(New->getLocation(), diag::err_final_function_overridden)
3064 << New->getDeclName()
3065 << FA->isSpelledAsSealed();
3066 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
3070 static bool InitializationHasSideEffects(const FieldDecl &FD) {
3071 const Type *T = FD.getType()->getBaseElementTypeUnsafe();
3072 // FIXME: Destruction of ObjC lifetime types has side-effects.
3073 if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
3074 return !RD->isCompleteDefinition() ||
3075 !RD->hasTrivialDefaultConstructor() ||
3076 !RD->hasTrivialDestructor();
3080 static const ParsedAttr *getMSPropertyAttr(const ParsedAttributesView &list) {
3081 ParsedAttributesView::const_iterator Itr =
3082 llvm::find_if(list, [](const ParsedAttr &AL) {
3083 return AL.isDeclspecPropertyAttribute();
3085 if (Itr != list.end())
3090 // Check if there is a field shadowing.
3091 void Sema::CheckShadowInheritedFields(const SourceLocation &Loc,
3092 DeclarationName FieldName,
3093 const CXXRecordDecl *RD,
3095 if (Diags.isIgnored(diag::warn_shadow_field, Loc))
3098 // To record a shadowed field in a base
3099 std::map<CXXRecordDecl*, NamedDecl*> Bases;
3100 auto FieldShadowed = [&](const CXXBaseSpecifier *Specifier,
3101 CXXBasePath &Path) {
3102 const auto Base = Specifier->getType()->getAsCXXRecordDecl();
3103 // Record an ambiguous path directly
3104 if (Bases.find(Base) != Bases.end())
3106 for (const auto Field : Base->lookup(FieldName)) {
3107 if ((isa<FieldDecl>(Field) || isa<IndirectFieldDecl>(Field)) &&
3108 Field->getAccess() != AS_private) {
3109 assert(Field->getAccess() != AS_none);
3110 assert(Bases.find(Base) == Bases.end());
3111 Bases[Base] = Field;
3118 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3119 /*DetectVirtual=*/true);
3120 if (!RD->lookupInBases(FieldShadowed, Paths))
3123 for (const auto &P : Paths) {
3124 auto Base = P.back().Base->getType()->getAsCXXRecordDecl();
3125 auto It = Bases.find(Base);
3126 // Skip duplicated bases
3127 if (It == Bases.end())
3129 auto BaseField = It->second;
3130 assert(BaseField->getAccess() != AS_private);
3132 CXXRecordDecl::MergeAccess(P.Access, BaseField->getAccess())) {
3133 Diag(Loc, diag::warn_shadow_field)
3134 << FieldName << RD << Base << DeclIsField;
3135 Diag(BaseField->getLocation(), diag::note_shadow_field);
3141 /// ActOnCXXMemberDeclarator - This is invoked when a C++ class member
3142 /// declarator is parsed. 'AS' is the access specifier, 'BW' specifies the
3143 /// bitfield width if there is one, 'InitExpr' specifies the initializer if
3144 /// one has been parsed, and 'InitStyle' is set if an in-class initializer is
3145 /// present (but parsing it has been deferred).
3147 Sema::ActOnCXXMemberDeclarator(Scope *S, AccessSpecifier AS, Declarator &D,
3148 MultiTemplateParamsArg TemplateParameterLists,
3149 Expr *BW, const VirtSpecifiers &VS,
3150 InClassInitStyle InitStyle) {
3151 const DeclSpec &DS = D.getDeclSpec();
3152 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
3153 DeclarationName Name = NameInfo.getName();
3154 SourceLocation Loc = NameInfo.getLoc();
3156 // For anonymous bitfields, the location should point to the type.
3157 if (Loc.isInvalid())
3158 Loc = D.getBeginLoc();
3160 Expr *BitWidth = static_cast<Expr*>(BW);
3162 assert(isa<CXXRecordDecl>(CurContext));
3163 assert(!DS.isFriendSpecified());
3165 bool isFunc = D.isDeclarationOfFunction();
3166 const ParsedAttr *MSPropertyAttr =
3167 getMSPropertyAttr(D.getDeclSpec().getAttributes());
3169 if (cast<CXXRecordDecl>(CurContext)->isInterface()) {
3170 // The Microsoft extension __interface only permits public member functions
3171 // and prohibits constructors, destructors, operators, non-public member
3172 // functions, static methods and data members.
3173 unsigned InvalidDecl;
3174 bool ShowDeclName = true;
3176 (DS.getStorageClassSpec() == DeclSpec::SCS_typedef || MSPropertyAttr))
3180 else if (AS != AS_public)
3182 else if (DS.getStorageClassSpec() == DeclSpec::SCS_static)
3184 else switch (Name.getNameKind()) {
3185 case DeclarationName::CXXConstructorName:
3187 ShowDeclName = false;
3190 case DeclarationName::CXXDestructorName:
3192 ShowDeclName = false;
3195 case DeclarationName::CXXOperatorName:
3196 case DeclarationName::CXXConversionFunctionName:
3207 Diag(Loc, diag::err_invalid_member_in_interface)
3208 << (InvalidDecl-1) << Name;
3210 Diag(Loc, diag::err_invalid_member_in_interface)
3211 << (InvalidDecl-1) << "";
3216 // C++ 9.2p6: A member shall not be declared to have automatic storage
3217 // duration (auto, register) or with the extern storage-class-specifier.
3218 // C++ 7.1.1p8: The mutable specifier can be applied only to names of class
3219 // data members and cannot be applied to names declared const or static,
3220 // and cannot be applied to reference members.
3221 switch (DS.getStorageClassSpec()) {
3222 case DeclSpec::SCS_unspecified:
3223 case DeclSpec::SCS_typedef:
3224 case DeclSpec::SCS_static:
3226 case DeclSpec::SCS_mutable:
3228 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_function);
3230 // FIXME: It would be nicer if the keyword was ignored only for this
3231 // declarator. Otherwise we could get follow-up errors.
3232 D.getMutableDeclSpec().ClearStorageClassSpecs();
3236 Diag(DS.getStorageClassSpecLoc(),
3237 diag::err_storageclass_invalid_for_member);
3238 D.getMutableDeclSpec().ClearStorageClassSpecs();
3242 bool isInstField = ((DS.getStorageClassSpec() == DeclSpec::SCS_unspecified ||
3243 DS.getStorageClassSpec() == DeclSpec::SCS_mutable) &&
3246 if (DS.hasConstexprSpecifier() && isInstField) {
3247 SemaDiagnosticBuilder B =
3248 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr_member);
3249 SourceLocation ConstexprLoc = DS.getConstexprSpecLoc();
3250 if (InitStyle == ICIS_NoInit) {
3252 if (D.getDeclSpec().getTypeQualifiers() & DeclSpec::TQ_const)
3253 B << FixItHint::CreateRemoval(ConstexprLoc);
3255 B << FixItHint::CreateReplacement(ConstexprLoc, "const");
3256 D.getMutableDeclSpec().ClearConstexprSpec();
3257 const char *PrevSpec;
3259 bool Failed = D.getMutableDeclSpec().SetTypeQual(
3260 DeclSpec::TQ_const, ConstexprLoc, PrevSpec, DiagID, getLangOpts());
3262 assert(!Failed && "Making a constexpr member const shouldn't fail");
3266 const char *PrevSpec;
3268 if (D.getMutableDeclSpec().SetStorageClassSpec(
3269 *this, DeclSpec::SCS_static, ConstexprLoc, PrevSpec, DiagID,
3270 Context.getPrintingPolicy())) {
3271 assert(DS.getStorageClassSpec() == DeclSpec::SCS_mutable &&
3272 "This is the only DeclSpec that should fail to be applied");
3275 B << 0 << FixItHint::CreateInsertion(ConstexprLoc, "static ");
3276 isInstField = false;
3283 CXXScopeSpec &SS = D.getCXXScopeSpec();
3285 // Data members must have identifiers for names.
3286 if (!Name.isIdentifier()) {
3287 Diag(Loc, diag::err_bad_variable_name)
3292 IdentifierInfo *II = Name.getAsIdentifierInfo();
3294 // Member field could not be with "template" keyword.
3295 // So TemplateParameterLists should be empty in this case.
3296 if (TemplateParameterLists.size()) {
3297 TemplateParameterList* TemplateParams = TemplateParameterLists[0];
3298 if (TemplateParams->size()) {
3299 // There is no such thing as a member field template.
3300 Diag(D.getIdentifierLoc(), diag::err_template_member)
3302 << SourceRange(TemplateParams->getTemplateLoc(),
3303 TemplateParams->getRAngleLoc());
3305 // There is an extraneous 'template<>' for this member.
3306 Diag(TemplateParams->getTemplateLoc(),
3307 diag::err_template_member_noparams)
3309 << SourceRange(TemplateParams->getTemplateLoc(),
3310 TemplateParams->getRAngleLoc());
3315 if (SS.isSet() && !SS.isInvalid()) {
3316 // The user provided a superfluous scope specifier inside a class
3322 if (DeclContext *DC = computeDeclContext(SS, false))
3323 diagnoseQualifiedDeclaration(SS, DC, Name, D.getIdentifierLoc(),
3324 D.getName().getKind() ==
3325 UnqualifiedIdKind::IK_TemplateId);
3327 Diag(D.getIdentifierLoc(), diag::err_member_qualification)
3328 << Name << SS.getRange();
3333 if (MSPropertyAttr) {
3334 Member = HandleMSProperty(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3335 BitWidth, InitStyle, AS, *MSPropertyAttr);
3338 isInstField = false;
3340 Member = HandleField(S, cast<CXXRecordDecl>(CurContext), Loc, D,
3341 BitWidth, InitStyle, AS);
3346 CheckShadowInheritedFields(Loc, Name, cast<CXXRecordDecl>(CurContext));
3348 Member = HandleDeclarator(S, D, TemplateParameterLists);
3352 // Non-instance-fields can't have a bitfield.
3354 if (Member->isInvalidDecl()) {
3355 // don't emit another diagnostic.
3356 } else if (isa<VarDecl>(Member) || isa<VarTemplateDecl>(Member)) {
3357 // C++ 9.6p3: A bit-field shall not be a static member.
3358 // "static member 'A' cannot be a bit-field"
3359 Diag(Loc, diag::err_static_not_bitfield)
3360 << Name << BitWidth->getSourceRange();
3361 } else if (isa<TypedefDecl>(Member)) {
3362 // "typedef member 'x' cannot be a bit-field"
3363 Diag(Loc, diag::err_typedef_not_bitfield)
3364 << Name << BitWidth->getSourceRange();
3366 // A function typedef ("typedef int f(); f a;").
3367 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
3368 Diag(Loc, diag::err_not_integral_type_bitfield)
3369 << Name << cast<ValueDecl>(Member)->getType()
3370 << BitWidth->getSourceRange();
3374 Member->setInvalidDecl();
3377 NamedDecl *NonTemplateMember = Member;
3378 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Member))
3379 NonTemplateMember = FunTmpl->getTemplatedDecl();
3380 else if (VarTemplateDecl *VarTmpl = dyn_cast<VarTemplateDecl>(Member))
3381 NonTemplateMember = VarTmpl->getTemplatedDecl();
3383 Member->setAccess(AS);
3385 // If we have declared a member function template or static data member
3386 // template, set the access of the templated declaration as well.
3387 if (NonTemplateMember != Member)
3388 NonTemplateMember->setAccess(AS);
3390 // C++ [temp.deduct.guide]p3:
3391 // A deduction guide [...] for a member class template [shall be
3392 // declared] with the same access [as the template].
3393 if (auto *DG = dyn_cast<CXXDeductionGuideDecl>(NonTemplateMember)) {
3394 auto *TD = DG->getDeducedTemplate();
3395 // Access specifiers are only meaningful if both the template and the
3396 // deduction guide are from the same scope.
3397 if (AS != TD->getAccess() &&
3398 TD->getDeclContext()->getRedeclContext()->Equals(
3399 DG->getDeclContext()->getRedeclContext())) {
3400 Diag(DG->getBeginLoc(), diag::err_deduction_guide_wrong_access);
3401 Diag(TD->getBeginLoc(), diag::note_deduction_guide_template_access)
3403 const AccessSpecDecl *LastAccessSpec = nullptr;
3404 for (const auto *D : cast<CXXRecordDecl>(CurContext)->decls()) {
3405 if (const auto *AccessSpec = dyn_cast<AccessSpecDecl>(D))
3406 LastAccessSpec = AccessSpec;
3408 assert(LastAccessSpec && "differing access with no access specifier");
3409 Diag(LastAccessSpec->getBeginLoc(), diag::note_deduction_guide_access)
3415 if (VS.isOverrideSpecified())
3416 Member->addAttr(OverrideAttr::Create(Context, VS.getOverrideLoc(),
3417 AttributeCommonInfo::AS_Keyword));
3418 if (VS.isFinalSpecified())
3419 Member->addAttr(FinalAttr::Create(
3420 Context, VS.getFinalLoc(), AttributeCommonInfo::AS_Keyword,
3421 static_cast<FinalAttr::Spelling>(VS.isFinalSpelledSealed())));
3423 if (VS.getLastLocation().isValid()) {
3424 // Update the end location of a method that has a virt-specifiers.
3425 if (CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Member))
3426 MD->setRangeEnd(VS.getLastLocation());
3429 CheckOverrideControl(Member);
3431 assert((Name || isInstField) && "No identifier for non-field ?");
3434 FieldDecl *FD = cast<FieldDecl>(Member);
3435 FieldCollector->Add(FD);
3437 if (!Diags.isIgnored(diag::warn_unused_private_field, FD->getLocation())) {
3438 // Remember all explicit private FieldDecls that have a name, no side
3439 // effects and are not part of a dependent type declaration.
3440 if (!FD->isImplicit() && FD->getDeclName() &&
3441 FD->getAccess() == AS_private &&
3442 !FD->hasAttr<UnusedAttr>() &&
3443 !FD->getParent()->isDependentContext() &&
3444 !InitializationHasSideEffects(*FD))
3445 UnusedPrivateFields.insert(FD);
3453 class UninitializedFieldVisitor
3454 : public EvaluatedExprVisitor<UninitializedFieldVisitor> {
3456 // List of Decls to generate a warning on. Also remove Decls that become
3458 llvm::SmallPtrSetImpl<ValueDecl*> &Decls;
3459 // List of base classes of the record. Classes are removed after their
3461 llvm::SmallPtrSetImpl<QualType> &BaseClasses;
3462 // Vector of decls to be removed from the Decl set prior to visiting the
3463 // nodes. These Decls may have been initialized in the prior initializer.
3464 llvm::SmallVector<ValueDecl*, 4> DeclsToRemove;
3465 // If non-null, add a note to the warning pointing back to the constructor.
3466 const CXXConstructorDecl *Constructor;
3467 // Variables to hold state when processing an initializer list. When
3468 // InitList is true, special case initialization of FieldDecls matching
3469 // InitListFieldDecl.
3471 FieldDecl *InitListFieldDecl;
3472 llvm::SmallVector<unsigned, 4> InitFieldIndex;
3475 typedef EvaluatedExprVisitor<UninitializedFieldVisitor> Inherited;
3476 UninitializedFieldVisitor(Sema &S,
3477 llvm::SmallPtrSetImpl<ValueDecl*> &Decls,
3478 llvm::SmallPtrSetImpl<QualType> &BaseClasses)
3479 : Inherited(S.Context), S(S), Decls(Decls), BaseClasses(BaseClasses),
3480 Constructor(nullptr), InitList(false), InitListFieldDecl(nullptr) {}
3482 // Returns true if the use of ME is not an uninitialized use.
3483 bool IsInitListMemberExprInitialized(MemberExpr *ME,
3484 bool CheckReferenceOnly) {
3485 llvm::SmallVector<FieldDecl*, 4> Fields;
3486 bool ReferenceField = false;
3488 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
3491 Fields.push_back(FD);
3492 if (FD->getType()->isReferenceType())
3493 ReferenceField = true;
3494 ME = dyn_cast<MemberExpr>(ME->getBase()->IgnoreParenImpCasts());
3497 // Binding a reference to an uninitialized field is not an
3498 // uninitialized use.
3499 if (CheckReferenceOnly && !ReferenceField)
3502 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
3503 // Discard the first field since it is the field decl that is being
3505 for (auto I = Fields.rbegin() + 1, E = Fields.rend(); I != E; ++I) {
3506 UsedFieldIndex.push_back((*I)->getFieldIndex());
3509 for (auto UsedIter = UsedFieldIndex.begin(),
3510 UsedEnd = UsedFieldIndex.end(),
3511 OrigIter = InitFieldIndex.begin(),
3512 OrigEnd = InitFieldIndex.end();
3513 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
3514 if (*UsedIter < *OrigIter)
3516 if (*UsedIter > *OrigIter)
3523 void HandleMemberExpr(MemberExpr *ME, bool CheckReferenceOnly,
3525 if (isa<EnumConstantDecl>(ME->getMemberDecl()))
3528 // FieldME is the inner-most MemberExpr that is not an anonymous struct
3530 MemberExpr *FieldME = ME;
3532 bool AllPODFields = FieldME->getType().isPODType(S.Context);
3535 while (MemberExpr *SubME =
3536 dyn_cast<MemberExpr>(Base->IgnoreParenImpCasts())) {
3538 if (isa<VarDecl>(SubME->getMemberDecl()))
3541 if (FieldDecl *FD = dyn_cast<FieldDecl>(SubME->getMemberDecl()))
3542 if (!FD->isAnonymousStructOrUnion())
3545 if (!FieldME->getType().isPODType(S.Context))
3546 AllPODFields = false;
3548 Base = SubME->getBase();
3551 if (!isa<CXXThisExpr>(Base->IgnoreParenImpCasts()))
3554 if (AddressOf && AllPODFields)
3557 ValueDecl* FoundVD = FieldME->getMemberDecl();
3559 if (ImplicitCastExpr *BaseCast = dyn_cast<ImplicitCastExpr>(Base)) {
3560 while (isa<ImplicitCastExpr>(BaseCast->getSubExpr())) {
3561 BaseCast = cast<ImplicitCastExpr>(BaseCast->getSubExpr());
3564 if (BaseCast->getCastKind() == CK_UncheckedDerivedToBase) {
3565 QualType T = BaseCast->getType();
3566 if (T->isPointerType() &&
3567 BaseClasses.count(T->getPointeeType())) {
3568 S.Diag(FieldME->getExprLoc(), diag::warn_base_class_is_uninit)
3569 << T->getPointeeType() << FoundVD;
3574 if (!Decls.count(FoundVD))
3577 const bool IsReference = FoundVD->getType()->isReferenceType();
3579 if (InitList && !AddressOf && FoundVD == InitListFieldDecl) {
3580 // Special checking for initializer lists.
3581 if (IsInitListMemberExprInitialized(ME, CheckReferenceOnly)) {
3585 // Prevent double warnings on use of unbounded references.
3586 if (CheckReferenceOnly && !IsReference)
3590 unsigned diag = IsReference
3591 ? diag::warn_reference_field_is_uninit
3592 : diag::warn_field_is_uninit;
3593 S.Diag(FieldME->getExprLoc(), diag) << FoundVD;
3595 S.Diag(Constructor->getLocation(),
3596 diag::note_uninit_in_this_constructor)
3597 << (Constructor->isDefaultConstructor() && Constructor->isImplicit());
3601 void HandleValue(Expr *E, bool AddressOf) {
3602 E = E->IgnoreParens();
3604 if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
3605 HandleMemberExpr(ME, false /*CheckReferenceOnly*/,
3606 AddressOf /*AddressOf*/);
3610 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
3611 Visit(CO->getCond());
3612 HandleValue(CO->getTrueExpr(), AddressOf);
3613 HandleValue(CO->getFalseExpr(), AddressOf);
3617 if (BinaryConditionalOperator *BCO =
3618 dyn_cast<BinaryConditionalOperator>(E)) {
3619 Visit(BCO->getCond());
3620 HandleValue(BCO->getFalseExpr(), AddressOf);
3624 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
3625 HandleValue(OVE->getSourceExpr(), AddressOf);
3629 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
3630 switch (BO->getOpcode()) {
3635 HandleValue(BO->getLHS(), AddressOf);
3636 Visit(BO->getRHS());
3639 Visit(BO->getLHS());
3640 HandleValue(BO->getRHS(), AddressOf);
3648 void CheckInitListExpr(InitListExpr *ILE) {
3649 InitFieldIndex.push_back(0);
3650 for (auto Child : ILE->children()) {
3651 if (InitListExpr *SubList = dyn_cast<InitListExpr>(Child)) {
3652 CheckInitListExpr(SubList);
3656 ++InitFieldIndex.back();
3658 InitFieldIndex.pop_back();
3661 void CheckInitializer(Expr *E, const CXXConstructorDecl *FieldConstructor,
3662 FieldDecl *Field, const Type *BaseClass) {
3663 // Remove Decls that may have been initialized in the previous
3665 for (ValueDecl* VD : DeclsToRemove)
3667 DeclsToRemove.clear();
3669 Constructor = FieldConstructor;
3670 InitListExpr *ILE = dyn_cast<InitListExpr>(E);
3674 InitListFieldDecl = Field;
3675 InitFieldIndex.clear();
3676 CheckInitListExpr(ILE);
3685 BaseClasses.erase(BaseClass->getCanonicalTypeInternal());
3688 void VisitMemberExpr(MemberExpr *ME) {
3689 // All uses of unbounded reference fields will warn.
3690 HandleMemberExpr(ME, true /*CheckReferenceOnly*/, false /*AddressOf*/);
3693 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
3694 if (E->getCastKind() == CK_LValueToRValue) {
3695 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3699 Inherited::VisitImplicitCastExpr(E);
3702 void VisitCXXConstructExpr(CXXConstructExpr *E) {
3703 if (E->getConstructor()->isCopyConstructor()) {
3704 Expr *ArgExpr = E->getArg(0);
3705 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
3706 if (ILE->getNumInits() == 1)
3707 ArgExpr = ILE->getInit(0);
3708 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
3709 if (ICE->getCastKind() == CK_NoOp)
3710 ArgExpr = ICE->getSubExpr();
3711 HandleValue(ArgExpr, false /*AddressOf*/);
3714 Inherited::VisitCXXConstructExpr(E);
3717 void VisitCXXMemberCallExpr(CXXMemberCallExpr *E) {
3718 Expr *Callee = E->getCallee();
3719 if (isa<MemberExpr>(Callee)) {
3720 HandleValue(Callee, false /*AddressOf*/);
3721 for (auto Arg : E->arguments())
3726 Inherited::VisitCXXMemberCallExpr(E);
3729 void VisitCallExpr(CallExpr *E) {
3730 // Treat std::move as a use.
3731 if (E->isCallToStdMove()) {
3732 HandleValue(E->getArg(0), /*AddressOf=*/false);
3736 Inherited::VisitCallExpr(E);
3739 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
3740 Expr *Callee = E->getCallee();
3742 if (isa<UnresolvedLookupExpr>(Callee))
3743 return Inherited::VisitCXXOperatorCallExpr(E);
3746 for (auto Arg : E->arguments())
3747 HandleValue(Arg->IgnoreParenImpCasts(), false /*AddressOf*/);
3750 void VisitBinaryOperator(BinaryOperator *E) {
3751 // If a field assignment is detected, remove the field from the
3752 // uninitiailized field set.
3753 if (E->getOpcode() == BO_Assign)
3754 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getLHS()))
3755 if (FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
3756 if (!FD->getType()->isReferenceType())
3757 DeclsToRemove.push_back(FD);
3759 if (E->isCompoundAssignmentOp()) {
3760 HandleValue(E->getLHS(), false /*AddressOf*/);
3765 Inherited::VisitBinaryOperator(E);
3768 void VisitUnaryOperator(UnaryOperator *E) {
3769 if (E->isIncrementDecrementOp()) {
3770 HandleValue(E->getSubExpr(), false /*AddressOf*/);
3773 if (E->getOpcode() == UO_AddrOf) {
3774 if (MemberExpr *ME = dyn_cast<MemberExpr>(E->getSubExpr())) {
3775 HandleValue(ME->getBase(), true /*AddressOf*/);
3780 Inherited::VisitUnaryOperator(E);
3784 // Diagnose value-uses of fields to initialize themselves, e.g.
3786 // where foo is not also a parameter to the constructor.
3787 // Also diagnose across field uninitialized use such as
3789 // TODO: implement -Wuninitialized and fold this into that framework.
3790 static void DiagnoseUninitializedFields(
3791 Sema &SemaRef, const CXXConstructorDecl *Constructor) {
3793 if (SemaRef.getDiagnostics().isIgnored(diag::warn_field_is_uninit,
3794 Constructor->getLocation())) {
3798 if (Constructor->isInvalidDecl())
3801 const CXXRecordDecl *RD = Constructor->getParent();
3803 if (RD->getDescribedClassTemplate())
3806 // Holds fields that are uninitialized.
3807 llvm::SmallPtrSet<ValueDecl*, 4> UninitializedFields;
3809 // At the beginning, all fields are uninitialized.
3810 for (auto *I : RD->decls()) {
3811 if (auto *FD = dyn_cast<FieldDecl>(I)) {
3812 UninitializedFields.insert(FD);
3813 } else if (auto *IFD = dyn_cast<IndirectFieldDecl>(I)) {
3814 UninitializedFields.insert(IFD->getAnonField());
3818 llvm::SmallPtrSet<QualType, 4> UninitializedBaseClasses;
3819 for (auto I : RD->bases())
3820 UninitializedBaseClasses.insert(I.getType().getCanonicalType());
3822 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3825 UninitializedFieldVisitor UninitializedChecker(SemaRef,
3826 UninitializedFields,
3827 UninitializedBaseClasses);
3829 for (const auto *FieldInit : Constructor->inits()) {
3830 if (UninitializedFields.empty() && UninitializedBaseClasses.empty())
3833 Expr *InitExpr = FieldInit->getInit();
3837 if (CXXDefaultInitExpr *Default =
3838 dyn_cast<CXXDefaultInitExpr>(InitExpr)) {
3839 InitExpr = Default->getExpr();
3842 // In class initializers will point to the constructor.
3843 UninitializedChecker.CheckInitializer(InitExpr, Constructor,
3844 FieldInit->getAnyMember(),
3845 FieldInit->getBaseClass());
3847 UninitializedChecker.CheckInitializer(InitExpr, nullptr,
3848 FieldInit->getAnyMember(),
3849 FieldInit->getBaseClass());
3855 /// Enter a new C++ default initializer scope. After calling this, the
3856 /// caller must call \ref ActOnFinishCXXInClassMemberInitializer, even if
3857 /// parsing or instantiating the initializer failed.
3858 void Sema::ActOnStartCXXInClassMemberInitializer() {
3859 // Create a synthetic function scope to represent the call to the constructor
3860 // that notionally surrounds a use of this initializer.
3861 PushFunctionScope();
3864 /// This is invoked after parsing an in-class initializer for a
3865 /// non-static C++ class member, and after instantiating an in-class initializer
3866 /// in a class template. Such actions are deferred until the class is complete.
3867 void Sema::ActOnFinishCXXInClassMemberInitializer(Decl *D,
3868 SourceLocation InitLoc,
3870 // Pop the notional constructor scope we created earlier.
3871 PopFunctionScopeInfo(nullptr, D);
3873 FieldDecl *FD = dyn_cast<FieldDecl>(D);
3874 assert((isa<MSPropertyDecl>(D) || FD->getInClassInitStyle() != ICIS_NoInit) &&
3875 "must set init style when field is created");
3878 D->setInvalidDecl();
3880 FD->removeInClassInitializer();
3884 if (DiagnoseUnexpandedParameterPack(InitExpr, UPPC_Initializer)) {
3885 FD->setInvalidDecl();
3886 FD->removeInClassInitializer();
3890 ExprResult Init = InitExpr;
3891 if (!FD->getType()->isDependentType() && !InitExpr->isTypeDependent()) {
3892 InitializedEntity Entity =
3893 InitializedEntity::InitializeMemberFromDefaultMemberInitializer(FD);
3894 InitializationKind Kind =
3895 FD->getInClassInitStyle() == ICIS_ListInit
3896 ? InitializationKind::CreateDirectList(InitExpr->getBeginLoc(),
3897 InitExpr->getBeginLoc(),
3898 InitExpr->getEndLoc())
3899 : InitializationKind::CreateCopy(InitExpr->getBeginLoc(), InitLoc);
3900 InitializationSequence Seq(*this, Entity, Kind, InitExpr);
3901 Init = Seq.Perform(*this, Entity, Kind, InitExpr);
3902 if (Init.isInvalid()) {
3903 FD->setInvalidDecl();
3908 // C++11 [class.base.init]p7:
3909 // The initialization of each base and member constitutes a
3911 Init = ActOnFinishFullExpr(Init.get(), InitLoc, /*DiscardedValue*/ false);
3912 if (Init.isInvalid()) {
3913 FD->setInvalidDecl();
3917 InitExpr = Init.get();
3919 FD->setInClassInitializer(InitExpr);
3922 /// Find the direct and/or virtual base specifiers that
3923 /// correspond to the given base type, for use in base initialization
3924 /// within a constructor.
3925 static bool FindBaseInitializer(Sema &SemaRef,
3926 CXXRecordDecl *ClassDecl,
3928 const CXXBaseSpecifier *&DirectBaseSpec,
3929 const CXXBaseSpecifier *&VirtualBaseSpec) {
3930 // First, check for a direct base class.
3931 DirectBaseSpec = nullptr;
3932 for (const auto &Base : ClassDecl->bases()) {
3933 if (SemaRef.Context.hasSameUnqualifiedType(BaseType, Base.getType())) {
3934 // We found a direct base of this type. That's what we're
3936 DirectBaseSpec = &Base;
3941 // Check for a virtual base class.
3942 // FIXME: We might be able to short-circuit this if we know in advance that
3943 // there are no virtual bases.
3944 VirtualBaseSpec = nullptr;
3945 if (!DirectBaseSpec || !DirectBaseSpec->isVirtual()) {
3946 // We haven't found a base yet; search the class hierarchy for a
3947 // virtual base class.
3948 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
3949 /*DetectVirtual=*/false);
3950 if (SemaRef.IsDerivedFrom(ClassDecl->getLocation(),
3951 SemaRef.Context.getTypeDeclType(ClassDecl),
3953 for (CXXBasePaths::paths_iterator Path = Paths.begin();
3954 Path != Paths.end(); ++Path) {
3955 if (Path->back().Base->isVirtual()) {
3956 VirtualBaseSpec = Path->back().Base;
3963 return DirectBaseSpec || VirtualBaseSpec;
3966 /// Handle a C++ member initializer using braced-init-list syntax.
3968 Sema::ActOnMemInitializer(Decl *ConstructorD,
3971 IdentifierInfo *MemberOrBase,
3972 ParsedType TemplateTypeTy,
3974 SourceLocation IdLoc,
3976 SourceLocation EllipsisLoc) {
3977 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3978 DS, IdLoc, InitList,
3982 /// Handle a C++ member initializer using parentheses syntax.
3984 Sema::ActOnMemInitializer(Decl *ConstructorD,
3987 IdentifierInfo *MemberOrBase,
3988 ParsedType TemplateTypeTy,
3990 SourceLocation IdLoc,
3991 SourceLocation LParenLoc,
3992 ArrayRef<Expr *> Args,
3993 SourceLocation RParenLoc,
3994 SourceLocation EllipsisLoc) {
3995 Expr *List = ParenListExpr::Create(Context, LParenLoc, Args, RParenLoc);
3996 return BuildMemInitializer(ConstructorD, S, SS, MemberOrBase, TemplateTypeTy,
3997 DS, IdLoc, List, EllipsisLoc);
4002 // Callback to only accept typo corrections that can be a valid C++ member
4003 // intializer: either a non-static field member or a base class.
4004 class MemInitializerValidatorCCC final : public CorrectionCandidateCallback {
4006 explicit MemInitializerValidatorCCC(CXXRecordDecl *ClassDecl)
4007 : ClassDecl(ClassDecl) {}
4009 bool ValidateCandidate(const TypoCorrection &candidate) override {
4010 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
4011 if (FieldDecl *Member = dyn_cast<FieldDecl>(ND))
4012 return Member->getDeclContext()->getRedeclContext()->Equals(ClassDecl);
4013 return isa<TypeDecl>(ND);
4018 std::unique_ptr<CorrectionCandidateCallback> clone() override {
4019 return std::make_unique<MemInitializerValidatorCCC>(*this);
4023 CXXRecordDecl *ClassDecl;
4028 ValueDecl *Sema::tryLookupCtorInitMemberDecl(CXXRecordDecl *ClassDecl,
4030 ParsedType TemplateTypeTy,
4031 IdentifierInfo *MemberOrBase) {
4032 if (SS.getScopeRep() || TemplateTypeTy)
4034 DeclContext::lookup_result Result = ClassDecl->lookup(MemberOrBase);
4038 if ((Member = dyn_cast<FieldDecl>(Result.front())) ||
4039 (Member = dyn_cast<IndirectFieldDecl>(Result.front())))
4044 /// Handle a C++ member initializer.
4046 Sema::BuildMemInitializer(Decl *ConstructorD,
4049 IdentifierInfo *MemberOrBase,
4050 ParsedType TemplateTypeTy,
4052 SourceLocation IdLoc,
4054 SourceLocation EllipsisLoc) {
4055 ExprResult Res = CorrectDelayedTyposInExpr(Init);
4056 if (!Res.isUsable())
4063 AdjustDeclIfTemplate(ConstructorD);
4065 CXXConstructorDecl *Constructor
4066 = dyn_cast<CXXConstructorDecl>(ConstructorD);
4068 // The user wrote a constructor initializer on a function that is
4069 // not a C++ constructor. Ignore the error for now, because we may
4070 // have more member initializers coming; we'll diagnose it just
4071 // once in ActOnMemInitializers.
4075 CXXRecordDecl *ClassDecl = Constructor->getParent();
4077 // C++ [class.base.init]p2:
4078 // Names in a mem-initializer-id are looked up in the scope of the
4079 // constructor's class and, if not found in that scope, are looked
4080 // up in the scope containing the constructor's definition.
4081 // [Note: if the constructor's class contains a member with the
4082 // same name as a direct or virtual base class of the class, a
4083 // mem-initializer-id naming the member or base class and composed
4084 // of a single identifier refers to the class member. A
4085 // mem-initializer-id for the hidden base class may be specified
4086 // using a qualified name. ]
4088 // Look for a member, first.
4089 if (ValueDecl *Member = tryLookupCtorInitMemberDecl(
4090 ClassDecl, SS, TemplateTypeTy, MemberOrBase)) {
4091 if (EllipsisLoc.isValid())
4092 Diag(EllipsisLoc, diag::err_pack_expansion_member_init)
4094 << SourceRange(IdLoc, Init->getSourceRange().getEnd());
4096 return BuildMemberInitializer(Member, Init, IdLoc);
4098 // It didn't name a member, so see if it names a class.
4100 TypeSourceInfo *TInfo = nullptr;
4102 if (TemplateTypeTy) {
4103 BaseType = GetTypeFromParser(TemplateTypeTy, &TInfo);
4104 if (BaseType.isNull())
4106 } else if (DS.getTypeSpecType() == TST_decltype) {
4107 BaseType = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
4108 } else if (DS.getTypeSpecType() == TST_decltype_auto) {
4109 Diag(DS.getTypeSpecTypeLoc(), diag::err_decltype_auto_invalid);
4112 LookupResult R(*this, MemberOrBase, IdLoc, LookupOrdinaryName);
4113 LookupParsedName(R, S, &SS);
4115 TypeDecl *TyD = R.getAsSingle<TypeDecl>();
4117 if (R.isAmbiguous()) return true;
4119 // We don't want access-control diagnostics here.
4120 R.suppressDiagnostics();
4122 if (SS.isSet() && isDependentScopeSpecifier(SS)) {
4123 bool NotUnknownSpecialization = false;
4124 DeclContext *DC = computeDeclContext(SS, false);
4125 if (CXXRecordDecl *Record = dyn_cast_or_null<CXXRecordDecl>(DC))
4126 NotUnknownSpecialization = !Record->hasAnyDependentBases();
4128 if (!NotUnknownSpecialization) {
4129 // When the scope specifier can refer to a member of an unknown
4130 // specialization, we take it as a type name.
4131 BaseType = CheckTypenameType(ETK_None, SourceLocation(),
4132 SS.getWithLocInContext(Context),
4133 *MemberOrBase, IdLoc);
4134 if (BaseType.isNull())
4137 TInfo = Context.CreateTypeSourceInfo(BaseType);
4138 DependentNameTypeLoc TL =
4139 TInfo->getTypeLoc().castAs<DependentNameTypeLoc>();
4141 TL.setNameLoc(IdLoc);
4142 TL.setElaboratedKeywordLoc(SourceLocation());
4143 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4147 R.setLookupName(MemberOrBase);
4151 // If no results were found, try to correct typos.
4152 TypoCorrection Corr;
4153 MemInitializerValidatorCCC CCC(ClassDecl);
4154 if (R.empty() && BaseType.isNull() &&
4155 (Corr = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS,
4156 CCC, CTK_ErrorRecovery, ClassDecl))) {
4157 if (FieldDecl *Member = Corr.getCorrectionDeclAs<FieldDecl>()) {
4158 // We have found a non-static data member with a similar
4159 // name to what was typed; complain and initialize that
4162 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4163 << MemberOrBase << true);
4164 return BuildMemberInitializer(Member, Init, IdLoc);
4165 } else if (TypeDecl *Type = Corr.getCorrectionDeclAs<TypeDecl>()) {
4166 const CXXBaseSpecifier *DirectBaseSpec;
4167 const CXXBaseSpecifier *VirtualBaseSpec;
4168 if (FindBaseInitializer(*this, ClassDecl,
4169 Context.getTypeDeclType(Type),
4170 DirectBaseSpec, VirtualBaseSpec)) {
4171 // We have found a direct or virtual base class with a
4172 // similar name to what was typed; complain and initialize
4175 PDiag(diag::err_mem_init_not_member_or_class_suggest)
4176 << MemberOrBase << false,
4177 PDiag() /*Suppress note, we provide our own.*/);
4179 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec ? DirectBaseSpec
4181 Diag(BaseSpec->getBeginLoc(), diag::note_base_class_specified_here)
4182 << BaseSpec->getType() << BaseSpec->getSourceRange();
4189 if (!TyD && BaseType.isNull()) {
4190 Diag(IdLoc, diag::err_mem_init_not_member_or_class)
4191 << MemberOrBase << SourceRange(IdLoc,Init->getSourceRange().getEnd());
4196 if (BaseType.isNull()) {
4197 BaseType = Context.getTypeDeclType(TyD);
4198 MarkAnyDeclReferenced(TyD->getLocation(), TyD, /*OdrUse=*/false);
4200 BaseType = Context.getElaboratedType(ETK_None, SS.getScopeRep(),
4202 TInfo = Context.CreateTypeSourceInfo(BaseType);
4203 ElaboratedTypeLoc TL = TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>();
4204 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IdLoc);
4205 TL.setElaboratedKeywordLoc(SourceLocation());
4206 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4212 TInfo = Context.getTrivialTypeSourceInfo(BaseType, IdLoc);
4214 return BuildBaseInitializer(BaseType, TInfo, Init, ClassDecl, EllipsisLoc);
4218 Sema::BuildMemberInitializer(ValueDecl *Member, Expr *Init,
4219 SourceLocation IdLoc) {
4220 FieldDecl *DirectMember = dyn_cast<FieldDecl>(Member);
4221 IndirectFieldDecl *IndirectMember = dyn_cast<IndirectFieldDecl>(Member);
4222 assert((DirectMember || IndirectMember) &&
4223 "Member must be a FieldDecl or IndirectFieldDecl");
4225 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4228 if (Member->isInvalidDecl())
4232 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4233 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4234 } else if (InitListExpr *InitList = dyn_cast<InitListExpr>(Init)) {
4235 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits());
4237 // Template instantiation doesn't reconstruct ParenListExprs for us.
4241 SourceRange InitRange = Init->getSourceRange();
4243 if (Member->getType()->isDependentType() || Init->isTypeDependent()) {
4244 // Can't check initialization for a member of dependent type or when
4245 // any of the arguments are type-dependent expressions.
4246 DiscardCleanupsInEvaluationContext();
4248 bool InitList = false;
4249 if (isa<InitListExpr>(Init)) {
4254 // Initialize the member.
4255 InitializedEntity MemberEntity =
4256 DirectMember ? InitializedEntity::InitializeMember(DirectMember, nullptr)
4257 : InitializedEntity::InitializeMember(IndirectMember,
4259 InitializationKind Kind =
4260 InitList ? InitializationKind::CreateDirectList(
4261 IdLoc, Init->getBeginLoc(), Init->getEndLoc())
4262 : InitializationKind::CreateDirect(IdLoc, InitRange.getBegin(),
4263 InitRange.getEnd());
4265 InitializationSequence InitSeq(*this, MemberEntity, Kind, Args);
4266 ExprResult MemberInit = InitSeq.Perform(*this, MemberEntity, Kind, Args,
4268 if (MemberInit.isInvalid())
4271 // C++11 [class.base.init]p7:
4272 // The initialization of each base and member constitutes a
4274 MemberInit = ActOnFinishFullExpr(MemberInit.get(), InitRange.getBegin(),
4275 /*DiscardedValue*/ false);
4276 if (MemberInit.isInvalid())
4279 Init = MemberInit.get();
4283 return new (Context) CXXCtorInitializer(Context, DirectMember, IdLoc,
4284 InitRange.getBegin(), Init,
4285 InitRange.getEnd());
4287 return new (Context) CXXCtorInitializer(Context, IndirectMember, IdLoc,
4288 InitRange.getBegin(), Init,
4289 InitRange.getEnd());
4294 Sema::BuildDelegatingInitializer(TypeSourceInfo *TInfo, Expr *Init,
4295 CXXRecordDecl *ClassDecl) {
4296 SourceLocation NameLoc = TInfo->getTypeLoc().getLocalSourceRange().getBegin();
4297 if (!LangOpts.CPlusPlus11)
4298 return Diag(NameLoc, diag::err_delegating_ctor)
4299 << TInfo->getTypeLoc().getLocalSourceRange();
4300 Diag(NameLoc, diag::warn_cxx98_compat_delegating_ctor);
4302 bool InitList = true;
4303 MultiExprArg Args = Init;
4304 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4306 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4309 SourceRange InitRange = Init->getSourceRange();
4310 // Initialize the object.
4311 InitializedEntity DelegationEntity = InitializedEntity::InitializeDelegation(
4312 QualType(ClassDecl->getTypeForDecl(), 0));
4313 InitializationKind Kind =
4314 InitList ? InitializationKind::CreateDirectList(
4315 NameLoc, Init->getBeginLoc(), Init->getEndLoc())
4316 : InitializationKind::CreateDirect(NameLoc, InitRange.getBegin(),
4317 InitRange.getEnd());
4318 InitializationSequence InitSeq(*this, DelegationEntity, Kind, Args);
4319 ExprResult DelegationInit = InitSeq.Perform(*this, DelegationEntity, Kind,
4321 if (DelegationInit.isInvalid())
4324 assert(cast<CXXConstructExpr>(DelegationInit.get())->getConstructor() &&
4325 "Delegating constructor with no target?");
4327 // C++11 [class.base.init]p7:
4328 // The initialization of each base and member constitutes a
4330 DelegationInit = ActOnFinishFullExpr(
4331 DelegationInit.get(), InitRange.getBegin(), /*DiscardedValue*/ false);
4332 if (DelegationInit.isInvalid())
4335 // If we are in a dependent context, template instantiation will
4336 // perform this type-checking again. Just save the arguments that we
4337 // received in a ParenListExpr.
4338 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4339 // of the information that we have about the base
4340 // initializer. However, deconstructing the ASTs is a dicey process,
4341 // and this approach is far more likely to get the corner cases right.
4342 if (CurContext->isDependentContext())
4343 DelegationInit = Init;
4345 return new (Context) CXXCtorInitializer(Context, TInfo, InitRange.getBegin(),
4346 DelegationInit.getAs<Expr>(),
4347 InitRange.getEnd());
4351 Sema::BuildBaseInitializer(QualType BaseType, TypeSourceInfo *BaseTInfo,
4352 Expr *Init, CXXRecordDecl *ClassDecl,
4353 SourceLocation EllipsisLoc) {
4354 SourceLocation BaseLoc
4355 = BaseTInfo->getTypeLoc().getLocalSourceRange().getBegin();
4357 if (!BaseType->isDependentType() && !BaseType->isRecordType())
4358 return Diag(BaseLoc, diag::err_base_init_does_not_name_class)
4359 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4361 // C++ [class.base.init]p2:
4362 // [...] Unless the mem-initializer-id names a nonstatic data
4363 // member of the constructor's class or a direct or virtual base
4364 // of that class, the mem-initializer is ill-formed. A
4365 // mem-initializer-list can initialize a base class using any
4366 // name that denotes that base class type.
4367 bool Dependent = BaseType->isDependentType() || Init->isTypeDependent();
4369 SourceRange InitRange = Init->getSourceRange();
4370 if (EllipsisLoc.isValid()) {
4371 // This is a pack expansion.
4372 if (!BaseType->containsUnexpandedParameterPack()) {
4373 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
4374 << SourceRange(BaseLoc, InitRange.getEnd());
4376 EllipsisLoc = SourceLocation();
4379 // Check for any unexpanded parameter packs.
4380 if (DiagnoseUnexpandedParameterPack(BaseLoc, BaseTInfo, UPPC_Initializer))
4383 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer))
4387 // Check for direct and virtual base classes.
4388 const CXXBaseSpecifier *DirectBaseSpec = nullptr;
4389 const CXXBaseSpecifier *VirtualBaseSpec = nullptr;
4391 if (Context.hasSameUnqualifiedType(QualType(ClassDecl->getTypeForDecl(),0),
4393 return BuildDelegatingInitializer(BaseTInfo, Init, ClassDecl);
4395 FindBaseInitializer(*this, ClassDecl, BaseType, DirectBaseSpec,
4398 // C++ [base.class.init]p2:
4399 // Unless the mem-initializer-id names a nonstatic data member of the
4400 // constructor's class or a direct or virtual base of that class, the
4401 // mem-initializer is ill-formed.
4402 if (!DirectBaseSpec && !VirtualBaseSpec) {
4403 // If the class has any dependent bases, then it's possible that
4404 // one of those types will resolve to the same type as
4405 // BaseType. Therefore, just treat this as a dependent base
4406 // class initialization. FIXME: Should we try to check the
4407 // initialization anyway? It seems odd.
4408 if (ClassDecl->hasAnyDependentBases())
4411 return Diag(BaseLoc, diag::err_not_direct_base_or_virtual)
4412 << BaseType << Context.getTypeDeclType(ClassDecl)
4413 << BaseTInfo->getTypeLoc().getLocalSourceRange();
4418 DiscardCleanupsInEvaluationContext();
4420 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4421 /*IsVirtual=*/false,
4422 InitRange.getBegin(), Init,
4423 InitRange.getEnd(), EllipsisLoc);
4426 // C++ [base.class.init]p2:
4427 // If a mem-initializer-id is ambiguous because it designates both
4428 // a direct non-virtual base class and an inherited virtual base
4429 // class, the mem-initializer is ill-formed.
4430 if (DirectBaseSpec && VirtualBaseSpec)
4431 return Diag(BaseLoc, diag::err_base_init_direct_and_virtual)
4432 << BaseType << BaseTInfo->getTypeLoc().getLocalSourceRange();
4434 const CXXBaseSpecifier *BaseSpec = DirectBaseSpec;
4436 BaseSpec = VirtualBaseSpec;
4438 // Initialize the base.
4439 bool InitList = true;
4440 MultiExprArg Args = Init;
4441 if (ParenListExpr *ParenList = dyn_cast<ParenListExpr>(Init)) {
4443 Args = MultiExprArg(ParenList->getExprs(), ParenList->getNumExprs());
4446 InitializedEntity BaseEntity =
4447 InitializedEntity::InitializeBase(Context, BaseSpec, VirtualBaseSpec);
4448 InitializationKind Kind =
4449 InitList ? InitializationKind::CreateDirectList(BaseLoc)
4450 : InitializationKind::CreateDirect(BaseLoc, InitRange.getBegin(),
4451 InitRange.getEnd());
4452 InitializationSequence InitSeq(*this, BaseEntity, Kind, Args);
4453 ExprResult BaseInit = InitSeq.Perform(*this, BaseEntity, Kind, Args, nullptr);
4454 if (BaseInit.isInvalid())
4457 // C++11 [class.base.init]p7:
4458 // The initialization of each base and member constitutes a
4460 BaseInit = ActOnFinishFullExpr(BaseInit.get(), InitRange.getBegin(),
4461 /*DiscardedValue*/ false);
4462 if (BaseInit.isInvalid())
4465 // If we are in a dependent context, template instantiation will
4466 // perform this type-checking again. Just save the arguments that we
4467 // received in a ParenListExpr.
4468 // FIXME: This isn't quite ideal, since our ASTs don't capture all
4469 // of the information that we have about the base
4470 // initializer. However, deconstructing the ASTs is a dicey process,
4471 // and this approach is far more likely to get the corner cases right.
4472 if (CurContext->isDependentContext())
4475 return new (Context) CXXCtorInitializer(Context, BaseTInfo,
4476 BaseSpec->isVirtual(),
4477 InitRange.getBegin(),
4478 BaseInit.getAs<Expr>(),
4479 InitRange.getEnd(), EllipsisLoc);
4482 // Create a static_cast\<T&&>(expr).
4483 static Expr *CastForMoving(Sema &SemaRef, Expr *E, QualType T = QualType()) {
4484 if (T.isNull()) T = E->getType();
4485 QualType TargetType = SemaRef.BuildReferenceType(
4486 T, /*SpelledAsLValue*/false, SourceLocation(), DeclarationName());
4487 SourceLocation ExprLoc = E->getBeginLoc();
4488 TypeSourceInfo *TargetLoc = SemaRef.Context.getTrivialTypeSourceInfo(
4489 TargetType, ExprLoc);
4491 return SemaRef.BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
4492 SourceRange(ExprLoc, ExprLoc),
4493 E->getSourceRange()).get();
4496 /// ImplicitInitializerKind - How an implicit base or member initializer should
4497 /// initialize its base or member.
4498 enum ImplicitInitializerKind {
4506 BuildImplicitBaseInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4507 ImplicitInitializerKind ImplicitInitKind,
4508 CXXBaseSpecifier *BaseSpec,
4509 bool IsInheritedVirtualBase,
4510 CXXCtorInitializer *&CXXBaseInit) {
4511 InitializedEntity InitEntity
4512 = InitializedEntity::InitializeBase(SemaRef.Context, BaseSpec,
4513 IsInheritedVirtualBase);
4515 ExprResult BaseInit;
4517 switch (ImplicitInitKind) {
4520 InitializationKind InitKind
4521 = InitializationKind::CreateDefault(Constructor->getLocation());
4522 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4523 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4529 bool Moving = ImplicitInitKind == IIK_Move;
4530 ParmVarDecl *Param = Constructor->getParamDecl(0);
4531 QualType ParamType = Param->getType().getNonReferenceType();
4534 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4535 SourceLocation(), Param, false,
4536 Constructor->getLocation(), ParamType,
4537 VK_LValue, nullptr);
4539 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(CopyCtorArg));
4541 // Cast to the base class to avoid ambiguities.
4543 SemaRef.Context.getQualifiedType(BaseSpec->getType().getUnqualifiedType(),
4544 ParamType.getQualifiers());
4547 CopyCtorArg = CastForMoving(SemaRef, CopyCtorArg);
4550 CXXCastPath BasePath;
4551 BasePath.push_back(BaseSpec);
4552 CopyCtorArg = SemaRef.ImpCastExprToType(CopyCtorArg, ArgTy,
4553 CK_UncheckedDerivedToBase,
4554 Moving ? VK_XValue : VK_LValue,
4557 InitializationKind InitKind
4558 = InitializationKind::CreateDirect(Constructor->getLocation(),
4559 SourceLocation(), SourceLocation());
4560 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, CopyCtorArg);
4561 BaseInit = InitSeq.Perform(SemaRef, InitEntity, InitKind, CopyCtorArg);
4566 BaseInit = SemaRef.MaybeCreateExprWithCleanups(BaseInit);
4567 if (BaseInit.isInvalid())
4571 new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4572 SemaRef.Context.getTrivialTypeSourceInfo(BaseSpec->getType(),
4574 BaseSpec->isVirtual(),
4576 BaseInit.getAs<Expr>(),
4583 static bool RefersToRValueRef(Expr *MemRef) {
4584 ValueDecl *Referenced = cast<MemberExpr>(MemRef)->getMemberDecl();
4585 return Referenced->getType()->isRValueReferenceType();
4589 BuildImplicitMemberInitializer(Sema &SemaRef, CXXConstructorDecl *Constructor,
4590 ImplicitInitializerKind ImplicitInitKind,
4591 FieldDecl *Field, IndirectFieldDecl *Indirect,
4592 CXXCtorInitializer *&CXXMemberInit) {
4593 if (Field->isInvalidDecl())
4596 SourceLocation Loc = Constructor->getLocation();
4598 if (ImplicitInitKind == IIK_Copy || ImplicitInitKind == IIK_Move) {
4599 bool Moving = ImplicitInitKind == IIK_Move;
4600 ParmVarDecl *Param = Constructor->getParamDecl(0);
4601 QualType ParamType = Param->getType().getNonReferenceType();
4603 // Suppress copying zero-width bitfields.
4604 if (Field->isZeroLengthBitField(SemaRef.Context))
4607 Expr *MemberExprBase =
4608 DeclRefExpr::Create(SemaRef.Context, NestedNameSpecifierLoc(),
4609 SourceLocation(), Param, false,
4610 Loc, ParamType, VK_LValue, nullptr);
4612 SemaRef.MarkDeclRefReferenced(cast<DeclRefExpr>(MemberExprBase));
4615 MemberExprBase = CastForMoving(SemaRef, MemberExprBase);
4618 // Build a reference to this field within the parameter.
4620 LookupResult MemberLookup(SemaRef, Field->getDeclName(), Loc,
4621 Sema::LookupMemberName);
4622 MemberLookup.addDecl(Indirect ? cast<ValueDecl>(Indirect)
4623 : cast<ValueDecl>(Field), AS_public);
4624 MemberLookup.resolveKind();
4626 = SemaRef.BuildMemberReferenceExpr(MemberExprBase,
4630 /*TemplateKWLoc=*/SourceLocation(),
4631 /*FirstQualifierInScope=*/nullptr,
4633 /*TemplateArgs=*/nullptr,
4635 if (CtorArg.isInvalid())
4638 // C++11 [class.copy]p15:
4639 // - if a member m has rvalue reference type T&&, it is direct-initialized
4640 // with static_cast<T&&>(x.m);
4641 if (RefersToRValueRef(CtorArg.get())) {
4642 CtorArg = CastForMoving(SemaRef, CtorArg.get());
4645 InitializedEntity Entity =
4646 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4648 : InitializedEntity::InitializeMember(Field, nullptr,
4651 // Direct-initialize to use the copy constructor.
4652 InitializationKind InitKind =
4653 InitializationKind::CreateDirect(Loc, SourceLocation(), SourceLocation());
4655 Expr *CtorArgE = CtorArg.getAs<Expr>();
4656 InitializationSequence InitSeq(SemaRef, Entity, InitKind, CtorArgE);
4657 ExprResult MemberInit =
4658 InitSeq.Perform(SemaRef, Entity, InitKind, MultiExprArg(&CtorArgE, 1));
4659 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4660 if (MemberInit.isInvalid())
4664 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4665 SemaRef.Context, Indirect, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4667 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(
4668 SemaRef.Context, Field, Loc, Loc, MemberInit.getAs<Expr>(), Loc);
4672 assert((ImplicitInitKind == IIK_Default || ImplicitInitKind == IIK_Inherit) &&
4673 "Unhandled implicit init kind!");
4675 QualType FieldBaseElementType =
4676 SemaRef.Context.getBaseElementType(Field->getType());
4678 if (FieldBaseElementType->isRecordType()) {
4679 InitializedEntity InitEntity =
4680 Indirect ? InitializedEntity::InitializeMember(Indirect, nullptr,
4682 : InitializedEntity::InitializeMember(Field, nullptr,
4684 InitializationKind InitKind =
4685 InitializationKind::CreateDefault(Loc);
4687 InitializationSequence InitSeq(SemaRef, InitEntity, InitKind, None);
4688 ExprResult MemberInit =
4689 InitSeq.Perform(SemaRef, InitEntity, InitKind, None);
4691 MemberInit = SemaRef.MaybeCreateExprWithCleanups(MemberInit);
4692 if (MemberInit.isInvalid())
4696 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4702 CXXMemberInit = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context,
4709 if (!Field->getParent()->isUnion()) {
4710 if (FieldBaseElementType->isReferenceType()) {
4711 SemaRef.Diag(Constructor->getLocation(),
4712 diag::err_uninitialized_member_in_ctor)
4713 << (int)Constructor->isImplicit()
4714 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4715 << 0 << Field->getDeclName();
4716 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4720 if (FieldBaseElementType.isConstQualified()) {
4721 SemaRef.Diag(Constructor->getLocation(),
4722 diag::err_uninitialized_member_in_ctor)
4723 << (int)Constructor->isImplicit()
4724 << SemaRef.Context.getTagDeclType(Constructor->getParent())
4725 << 1 << Field->getDeclName();
4726 SemaRef.Diag(Field->getLocation(), diag::note_declared_at);
4731 if (FieldBaseElementType.hasNonTrivialObjCLifetime()) {
4733 // Default-initialize Objective-C pointers to NULL.
4735 = new (SemaRef.Context) CXXCtorInitializer(SemaRef.Context, Field,
4737 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType()),
4742 // Nothing to initialize.
4743 CXXMemberInit = nullptr;
4748 struct BaseAndFieldInfo {
4750 CXXConstructorDecl *Ctor;
4751 bool AnyErrorsInInits;
4752 ImplicitInitializerKind IIK;
4753 llvm::DenseMap<const void *, CXXCtorInitializer*> AllBaseFields;
4754 SmallVector<CXXCtorInitializer*, 8> AllToInit;
4755 llvm::DenseMap<TagDecl*, FieldDecl*> ActiveUnionMember;
4757 BaseAndFieldInfo(Sema &S, CXXConstructorDecl *Ctor, bool ErrorsInInits)
4758 : S(S), Ctor(Ctor), AnyErrorsInInits(ErrorsInInits) {
4759 bool Generated = Ctor->isImplicit() || Ctor->isDefaulted();
4760 if (Ctor->getInheritedConstructor())
4762 else if (Generated && Ctor->isCopyConstructor())
4764 else if (Generated && Ctor->isMoveConstructor())
4770 bool isImplicitCopyOrMove() const {
4781 llvm_unreachable("Invalid ImplicitInitializerKind!");
4784 bool addFieldInitializer(CXXCtorInitializer *Init) {
4785 AllToInit.push_back(Init);
4787 // Check whether this initializer makes the field "used".
4788 if (Init->getInit()->HasSideEffects(S.Context))
4789 S.UnusedPrivateFields.remove(Init->getAnyMember());
4794 bool isInactiveUnionMember(FieldDecl *Field) {
4795 RecordDecl *Record = Field->getParent();
4796 if (!Record->isUnion())
4799 if (FieldDecl *Active =
4800 ActiveUnionMember.lookup(Record->getCanonicalDecl()))
4801 return Active != Field->getCanonicalDecl();
4803 // In an implicit copy or move constructor, ignore any in-class initializer.
4804 if (isImplicitCopyOrMove())
4807 // If there's no explicit initialization, the field is active only if it
4808 // has an in-class initializer...
4809 if (Field->hasInClassInitializer())
4811 // ... or it's an anonymous struct or union whose class has an in-class
4813 if (!Field->isAnonymousStructOrUnion())
4815 CXXRecordDecl *FieldRD = Field->getType()->getAsCXXRecordDecl();
4816 return !FieldRD->hasInClassInitializer();
4819 /// Determine whether the given field is, or is within, a union member
4820 /// that is inactive (because there was an initializer given for a different
4821 /// member of the union, or because the union was not initialized at all).
4822 bool isWithinInactiveUnionMember(FieldDecl *Field,
4823 IndirectFieldDecl *Indirect) {
4825 return isInactiveUnionMember(Field);
4827 for (auto *C : Indirect->chain()) {
4828 FieldDecl *Field = dyn_cast<FieldDecl>(C);
4829 if (Field && isInactiveUnionMember(Field))
4837 /// Determine whether the given type is an incomplete or zero-lenfgth
4839 static bool isIncompleteOrZeroLengthArrayType(ASTContext &Context, QualType T) {
4840 if (T->isIncompleteArrayType())
4843 while (const ConstantArrayType *ArrayT = Context.getAsConstantArrayType(T)) {
4844 if (!ArrayT->getSize())
4847 T = ArrayT->getElementType();
4853 static bool CollectFieldInitializer(Sema &SemaRef, BaseAndFieldInfo &Info,
4855 IndirectFieldDecl *Indirect = nullptr) {
4856 if (Field->isInvalidDecl())
4859 // Overwhelmingly common case: we have a direct initializer for this field.
4860 if (CXXCtorInitializer *Init =
4861 Info.AllBaseFields.lookup(Field->getCanonicalDecl()))
4862 return Info.addFieldInitializer(Init);
4864 // C++11 [class.base.init]p8:
4865 // if the entity is a non-static data member that has a
4866 // brace-or-equal-initializer and either
4867 // -- the constructor's class is a union and no other variant member of that
4868 // union is designated by a mem-initializer-id or
4869 // -- the constructor's class is not a union, and, if the entity is a member
4870 // of an anonymous union, no other member of that union is designated by
4871 // a mem-initializer-id,
4872 // the entity is initialized as specified in [dcl.init].
4874 // We also apply the same rules to handle anonymous structs within anonymous
4876 if (Info.isWithinInactiveUnionMember(Field, Indirect))
4879 if (Field->hasInClassInitializer() && !Info.isImplicitCopyOrMove()) {
4881 SemaRef.BuildCXXDefaultInitExpr(Info.Ctor->getLocation(), Field);
4882 if (DIE.isInvalid())
4885 auto Entity = InitializedEntity::InitializeMember(Field, nullptr, true);
4886 SemaRef.checkInitializerLifetime(Entity, DIE.get());
4888 CXXCtorInitializer *Init;
4890 Init = new (SemaRef.Context)
4891 CXXCtorInitializer(SemaRef.Context, Indirect, SourceLocation(),
4892 SourceLocation(), DIE.get(), SourceLocation());
4894 Init = new (SemaRef.Context)
4895 CXXCtorInitializer(SemaRef.Context, Field, SourceLocation(),
4896 SourceLocation(), DIE.get(), SourceLocation());
4897 return Info.addFieldInitializer(Init);
4900 // Don't initialize incomplete or zero-length arrays.
4901 if (isIncompleteOrZeroLengthArrayType(SemaRef.Context, Field->getType()))
4904 // Don't try to build an implicit initializer if there were semantic
4905 // errors in any of the initializers (and therefore we might be
4906 // missing some that the user actually wrote).
4907 if (Info.AnyErrorsInInits)
4910 CXXCtorInitializer *Init = nullptr;
4911 if (BuildImplicitMemberInitializer(Info.S, Info.Ctor, Info.IIK, Field,
4918 return Info.addFieldInitializer(Init);
4922 Sema::SetDelegatingInitializer(CXXConstructorDecl *Constructor,
4923 CXXCtorInitializer *Initializer) {
4924 assert(Initializer->isDelegatingInitializer());
4925 Constructor->setNumCtorInitializers(1);
4926 CXXCtorInitializer **initializer =
4927 new (Context) CXXCtorInitializer*[1];
4928 memcpy(initializer, &Initializer, sizeof (CXXCtorInitializer*));
4929 Constructor->setCtorInitializers(initializer);
4931 if (CXXDestructorDecl *Dtor = LookupDestructor(Constructor->getParent())) {
4932 MarkFunctionReferenced(Initializer->getSourceLocation(), Dtor);
4933 DiagnoseUseOfDecl(Dtor, Initializer->getSourceLocation());
4936 DelegatingCtorDecls.push_back(Constructor);
4938 DiagnoseUninitializedFields(*this, Constructor);
4943 bool Sema::SetCtorInitializers(CXXConstructorDecl *Constructor, bool AnyErrors,
4944 ArrayRef<CXXCtorInitializer *> Initializers) {
4945 if (Constructor->isDependentContext()) {
4946 // Just store the initializers as written, they will be checked during
4948 if (!Initializers.empty()) {
4949 Constructor->setNumCtorInitializers(Initializers.size());
4950 CXXCtorInitializer **baseOrMemberInitializers =
4951 new (Context) CXXCtorInitializer*[Initializers.size()];
4952 memcpy(baseOrMemberInitializers, Initializers.data(),
4953 Initializers.size() * sizeof(CXXCtorInitializer*));
4954 Constructor->setCtorInitializers(baseOrMemberInitializers);
4957 // Let template instantiation know whether we had errors.
4959 Constructor->setInvalidDecl();
4964 BaseAndFieldInfo Info(*this, Constructor, AnyErrors);
4966 // We need to build the initializer AST according to order of construction
4967 // and not what user specified in the Initializers list.
4968 CXXRecordDecl *ClassDecl = Constructor->getParent()->getDefinition();
4972 bool HadError = false;
4974 for (unsigned i = 0; i < Initializers.size(); i++) {
4975 CXXCtorInitializer *Member = Initializers[i];
4977 if (Member->isBaseInitializer())
4978 Info.AllBaseFields[Member->getBaseClass()->getAs<RecordType>()] = Member;
4980 Info.AllBaseFields[Member->getAnyMember()->getCanonicalDecl()] = Member;
4982 if (IndirectFieldDecl *F = Member->getIndirectMember()) {
4983 for (auto *C : F->chain()) {
4984 FieldDecl *FD = dyn_cast<FieldDecl>(C);
4985 if (FD && FD->getParent()->isUnion())
4986 Info.ActiveUnionMember.insert(std::make_pair(
4987 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4989 } else if (FieldDecl *FD = Member->getMember()) {
4990 if (FD->getParent()->isUnion())
4991 Info.ActiveUnionMember.insert(std::make_pair(
4992 FD->getParent()->getCanonicalDecl(), FD->getCanonicalDecl()));
4997 // Keep track of the direct virtual bases.
4998 llvm::SmallPtrSet<CXXBaseSpecifier *, 16> DirectVBases;
4999 for (auto &I : ClassDecl->bases()) {
5001 DirectVBases.insert(&I);
5004 // Push virtual bases before others.
5005 for (auto &VBase : ClassDecl->vbases()) {
5006 if (CXXCtorInitializer *Value
5007 = Info.AllBaseFields.lookup(VBase.getType()->getAs<RecordType>())) {
5008 // [class.base.init]p7, per DR257:
5009 // A mem-initializer where the mem-initializer-id names a virtual base
5010 // class is ignored during execution of a constructor of any class that
5011 // is not the most derived class.
5012 if (ClassDecl->isAbstract()) {
5013 // FIXME: Provide a fixit to remove the base specifier. This requires
5014 // tracking the location of the associated comma for a base specifier.
5015 Diag(Value->getSourceLocation(), diag::warn_abstract_vbase_init_ignored)
5016 << VBase.getType() << ClassDecl;
5017 DiagnoseAbstractType(ClassDecl);
5020 Info.AllToInit.push_back(Value);
5021 } else if (!AnyErrors && !ClassDecl->isAbstract()) {
5022 // [class.base.init]p8, per DR257:
5023 // If a given [...] base class is not named by a mem-initializer-id
5024 // [...] and the entity is not a virtual base class of an abstract
5025 // class, then [...] the entity is default-initialized.
5026 bool IsInheritedVirtualBase = !DirectVBases.count(&VBase);
5027 CXXCtorInitializer *CXXBaseInit;
5028 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5029 &VBase, IsInheritedVirtualBase,
5035 Info.AllToInit.push_back(CXXBaseInit);
5039 // Non-virtual bases.
5040 for (auto &Base : ClassDecl->bases()) {
5041 // Virtuals are in the virtual base list and already constructed.
5042 if (Base.isVirtual())
5045 if (CXXCtorInitializer *Value
5046 = Info.AllBaseFields.lookup(Base.getType()->getAs<RecordType>())) {
5047 Info.AllToInit.push_back(Value);
5048 } else if (!AnyErrors) {
5049 CXXCtorInitializer *CXXBaseInit;
5050 if (BuildImplicitBaseInitializer(*this, Constructor, Info.IIK,
5051 &Base, /*IsInheritedVirtualBase=*/false,
5057 Info.AllToInit.push_back(CXXBaseInit);
5062 for (auto *Mem : ClassDecl->decls()) {
5063 if (auto *F = dyn_cast<FieldDecl>(Mem)) {
5064 // C++ [class.bit]p2:
5065 // A declaration for a bit-field that omits the identifier declares an
5066 // unnamed bit-field. Unnamed bit-fields are not members and cannot be
5068 if (F->isUnnamedBitfield())
5071 // If we're not generating the implicit copy/move constructor, then we'll
5072 // handle anonymous struct/union fields based on their individual
5074 if (F->isAnonymousStructOrUnion() && !Info.isImplicitCopyOrMove())
5077 if (CollectFieldInitializer(*this, Info, F))
5082 // Beyond this point, we only consider default initialization.
5083 if (Info.isImplicitCopyOrMove())
5086 if (auto *F = dyn_cast<IndirectFieldDecl>(Mem)) {
5087 if (F->getType()->isIncompleteArrayType()) {
5088 assert(ClassDecl->hasFlexibleArrayMember() &&
5089 "Incomplete array type is not valid");
5093 // Initialize each field of an anonymous struct individually.
5094 if (CollectFieldInitializer(*this, Info, F->getAnonField(), F))
5101 unsigned NumInitializers = Info.AllToInit.size();
5102 if (NumInitializers > 0) {
5103 Constructor->setNumCtorInitializers(NumInitializers);
5104 CXXCtorInitializer **baseOrMemberInitializers =
5105 new (Context) CXXCtorInitializer*[NumInitializers];
5106 memcpy(baseOrMemberInitializers, Info.AllToInit.data(),
5107 NumInitializers * sizeof(CXXCtorInitializer*));
5108 Constructor->setCtorInitializers(baseOrMemberInitializers);
5110 // Constructors implicitly reference the base and member
5112 MarkBaseAndMemberDestructorsReferenced(Constructor->getLocation(),
5113 Constructor->getParent());
5119 static void PopulateKeysForFields(FieldDecl *Field, SmallVectorImpl<const void*> &IdealInits) {
5120 if (const RecordType *RT = Field->getType()->getAs<RecordType>()) {
5121 const RecordDecl *RD = RT->getDecl();
5122 if (RD->isAnonymousStructOrUnion()) {
5123 for (auto *Field : RD->fields())
5124 PopulateKeysForFields(Field, IdealInits);
5128 IdealInits.push_back(Field->getCanonicalDecl());
5131 static const void *GetKeyForBase(ASTContext &Context, QualType BaseType) {
5132 return Context.getCanonicalType(BaseType).getTypePtr();
5135 static const void *GetKeyForMember(ASTContext &Context,
5136 CXXCtorInitializer *Member) {
5137 if (!Member->isAnyMemberInitializer())
5138 return GetKeyForBase(Context, QualType(Member->getBaseClass(), 0));
5140 return Member->getAnyMember()->getCanonicalDecl();
5143 static void DiagnoseBaseOrMemInitializerOrder(
5144 Sema &SemaRef, const CXXConstructorDecl *Constructor,
5145 ArrayRef<CXXCtorInitializer *> Inits) {
5146 if (Constructor->getDeclContext()->isDependentContext())
5149 // Don't check initializers order unless the warning is enabled at the
5150 // location of at least one initializer.
5151 bool ShouldCheckOrder = false;
5152 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5153 CXXCtorInitializer *Init = Inits[InitIndex];
5154 if (!SemaRef.Diags.isIgnored(diag::warn_initializer_out_of_order,
5155 Init->getSourceLocation())) {
5156 ShouldCheckOrder = true;
5160 if (!ShouldCheckOrder)
5163 // Build the list of bases and members in the order that they'll
5164 // actually be initialized. The explicit initializers should be in
5165 // this same order but may be missing things.
5166 SmallVector<const void*, 32> IdealInitKeys;
5168 const CXXRecordDecl *ClassDecl = Constructor->getParent();
5170 // 1. Virtual bases.
5171 for (const auto &VBase : ClassDecl->vbases())
5172 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, VBase.getType()));
5174 // 2. Non-virtual bases.
5175 for (const auto &Base : ClassDecl->bases()) {
5176 if (Base.isVirtual())
5178 IdealInitKeys.push_back(GetKeyForBase(SemaRef.Context, Base.getType()));
5181 // 3. Direct fields.
5182 for (auto *Field : ClassDecl->fields()) {
5183 if (Field->isUnnamedBitfield())
5186 PopulateKeysForFields(Field, IdealInitKeys);
5189 unsigned NumIdealInits = IdealInitKeys.size();
5190 unsigned IdealIndex = 0;
5192 CXXCtorInitializer *PrevInit = nullptr;
5193 for (unsigned InitIndex = 0; InitIndex != Inits.size(); ++InitIndex) {
5194 CXXCtorInitializer *Init = Inits[InitIndex];
5195 const void *InitKey = GetKeyForMember(SemaRef.Context, Init);
5197 // Scan forward to try to find this initializer in the idealized
5198 // initializers list.
5199 for (; IdealIndex != NumIdealInits; ++IdealIndex)
5200 if (InitKey == IdealInitKeys[IdealIndex])
5203 // If we didn't find this initializer, it must be because we
5204 // scanned past it on a previous iteration. That can only
5205 // happen if we're out of order; emit a warning.
5206 if (IdealIndex == NumIdealInits && PrevInit) {
5207 Sema::SemaDiagnosticBuilder D =
5208 SemaRef.Diag(PrevInit->getSourceLocation(),
5209 diag::warn_initializer_out_of_order);
5211 if (PrevInit->isAnyMemberInitializer())
5212 D << 0 << PrevInit->getAnyMember()->getDeclName();
5214 D << 1 << PrevInit->getTypeSourceInfo()->getType();
5216 if (Init->isAnyMemberInitializer())
5217 D << 0 << Init->getAnyMember()->getDeclName();
5219 D << 1 << Init->getTypeSourceInfo()->getType();
5221 // Move back to the initializer's location in the ideal list.
5222 for (IdealIndex = 0; IdealIndex != NumIdealInits; ++IdealIndex)
5223 if (InitKey == IdealInitKeys[IdealIndex])
5226 assert(IdealIndex < NumIdealInits &&
5227 "initializer not found in initializer list");
5235 bool CheckRedundantInit(Sema &S,
5236 CXXCtorInitializer *Init,
5237 CXXCtorInitializer *&PrevInit) {
5243 if (FieldDecl *Field = Init->getAnyMember())
5244 S.Diag(Init->getSourceLocation(),
5245 diag::err_multiple_mem_initialization)
5246 << Field->getDeclName()
5247 << Init->getSourceRange();
5249 const Type *BaseClass = Init->getBaseClass();
5250 assert(BaseClass && "neither field nor base");
5251 S.Diag(Init->getSourceLocation(),
5252 diag::err_multiple_base_initialization)
5253 << QualType(BaseClass, 0)
5254 << Init->getSourceRange();
5256 S.Diag(PrevInit->getSourceLocation(), diag::note_previous_initializer)
5257 << 0 << PrevInit->getSourceRange();
5262 typedef std::pair<NamedDecl *, CXXCtorInitializer *> UnionEntry;
5263 typedef llvm::DenseMap<RecordDecl*, UnionEntry> RedundantUnionMap;
5265 bool CheckRedundantUnionInit(Sema &S,
5266 CXXCtorInitializer *Init,
5267 RedundantUnionMap &Unions) {
5268 FieldDecl *Field = Init->getAnyMember();
5269 RecordDecl *Parent = Field->getParent();
5270 NamedDecl *Child = Field;
5272 while (Parent->isAnonymousStructOrUnion() || Parent->isUnion()) {
5273 if (Parent->isUnion()) {
5274 UnionEntry &En = Unions[Parent];
5275 if (En.first && En.first != Child) {
5276 S.Diag(Init->getSourceLocation(),
5277 diag::err_multiple_mem_union_initialization)
5278 << Field->getDeclName()
5279 << Init->getSourceRange();
5280 S.Diag(En.second->getSourceLocation(), diag::note_previous_initializer)
5281 << 0 << En.second->getSourceRange();
5288 if (!Parent->isAnonymousStructOrUnion())
5293 Parent = cast<RecordDecl>(Parent->getDeclContext());
5300 /// ActOnMemInitializers - Handle the member initializers for a constructor.
5301 void Sema::ActOnMemInitializers(Decl *ConstructorDecl,
5302 SourceLocation ColonLoc,
5303 ArrayRef<CXXCtorInitializer*> MemInits,
5305 if (!ConstructorDecl)
5308 AdjustDeclIfTemplate(ConstructorDecl);
5310 CXXConstructorDecl *Constructor
5311 = dyn_cast<CXXConstructorDecl>(ConstructorDecl);
5314 Diag(ColonLoc, diag::err_only_constructors_take_base_inits);
5318 // Mapping for the duplicate initializers check.
5319 // For member initializers, this is keyed with a FieldDecl*.
5320 // For base initializers, this is keyed with a Type*.
5321 llvm::DenseMap<const void *, CXXCtorInitializer *> Members;
5323 // Mapping for the inconsistent anonymous-union initializers check.
5324 RedundantUnionMap MemberUnions;
5326 bool HadError = false;
5327 for (unsigned i = 0; i < MemInits.size(); i++) {
5328 CXXCtorInitializer *Init = MemInits[i];
5330 // Set the source order index.
5331 Init->setSourceOrder(i);
5333 if (Init->isAnyMemberInitializer()) {
5334 const void *Key = GetKeyForMember(Context, Init);
5335 if (CheckRedundantInit(*this, Init, Members[Key]) ||
5336 CheckRedundantUnionInit(*this, Init, MemberUnions))
5338 } else if (Init->isBaseInitializer()) {
5339 const void *Key = GetKeyForMember(Context, Init);
5340 if (CheckRedundantInit(*this, Init, Members[Key]))
5343 assert(Init->isDelegatingInitializer());
5344 // This must be the only initializer
5345 if (MemInits.size() != 1) {
5346 Diag(Init->getSourceLocation(),
5347 diag::err_delegating_initializer_alone)
5348 << Init->getSourceRange() << MemInits[i ? 0 : 1]->getSourceRange();
5349 // We will treat this as being the only initializer.
5351 SetDelegatingInitializer(Constructor, MemInits[i]);
5352 // Return immediately as the initializer is set.
5360 DiagnoseBaseOrMemInitializerOrder(*this, Constructor, MemInits);
5362 SetCtorInitializers(Constructor, AnyErrors, MemInits);
5364 DiagnoseUninitializedFields(*this, Constructor);
5368 Sema::MarkBaseAndMemberDestructorsReferenced(SourceLocation Location,
5369 CXXRecordDecl *ClassDecl) {
5370 // Ignore dependent contexts. Also ignore unions, since their members never
5371 // have destructors implicitly called.
5372 if (ClassDecl->isDependentContext() || ClassDecl->isUnion())
5375 // FIXME: all the access-control diagnostics are positioned on the
5376 // field/base declaration. That's probably good; that said, the
5377 // user might reasonably want to know why the destructor is being
5378 // emitted, and we currently don't say.
5380 // Non-static data members.
5381 for (auto *Field : ClassDecl->fields()) {
5382 if (Field->isInvalidDecl())
5385 // Don't destroy incomplete or zero-length arrays.
5386 if (isIncompleteOrZeroLengthArrayType(Context, Field->getType()))
5389 QualType FieldType = Context.getBaseElementType(Field->getType());
5391 const RecordType* RT = FieldType->getAs<RecordType>();
5395 CXXRecordDecl *FieldClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5396 if (FieldClassDecl->isInvalidDecl())
5398 if (FieldClassDecl->hasIrrelevantDestructor())
5400 // The destructor for an implicit anonymous union member is never invoked.
5401 if (FieldClassDecl->isUnion() && FieldClassDecl->isAnonymousStructOrUnion())
5404 CXXDestructorDecl *Dtor = LookupDestructor(FieldClassDecl);
5405 assert(Dtor && "No dtor found for FieldClassDecl!");
5406 CheckDestructorAccess(Field->getLocation(), Dtor,
5407 PDiag(diag::err_access_dtor_field)
5408 << Field->getDeclName()
5411 MarkFunctionReferenced(Location, Dtor);
5412 DiagnoseUseOfDecl(Dtor, Location);
5415 // We only potentially invoke the destructors of potentially constructed
5417 bool VisitVirtualBases = !ClassDecl->isAbstract();
5419 llvm::SmallPtrSet<const RecordType *, 8> DirectVirtualBases;
5422 for (const auto &Base : ClassDecl->bases()) {
5423 // Bases are always records in a well-formed non-dependent class.
5424 const RecordType *RT = Base.getType()->getAs<RecordType>();
5426 // Remember direct virtual bases.
5427 if (Base.isVirtual()) {
5428 if (!VisitVirtualBases)
5430 DirectVirtualBases.insert(RT);
5433 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5434 // If our base class is invalid, we probably can't get its dtor anyway.
5435 if (BaseClassDecl->isInvalidDecl())
5437 if (BaseClassDecl->hasIrrelevantDestructor())
5440 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5441 assert(Dtor && "No dtor found for BaseClassDecl!");
5443 // FIXME: caret should be on the start of the class name
5444 CheckDestructorAccess(Base.getBeginLoc(), Dtor,
5445 PDiag(diag::err_access_dtor_base)
5446 << Base.getType() << Base.getSourceRange(),
5447 Context.getTypeDeclType(ClassDecl));
5449 MarkFunctionReferenced(Location, Dtor);
5450 DiagnoseUseOfDecl(Dtor, Location);
5453 if (!VisitVirtualBases)
5457 for (const auto &VBase : ClassDecl->vbases()) {
5458 // Bases are always records in a well-formed non-dependent class.
5459 const RecordType *RT = VBase.getType()->castAs<RecordType>();
5461 // Ignore direct virtual bases.
5462 if (DirectVirtualBases.count(RT))
5465 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(RT->getDecl());
5466 // If our base class is invalid, we probably can't get its dtor anyway.
5467 if (BaseClassDecl->isInvalidDecl())
5469 if (BaseClassDecl->hasIrrelevantDestructor())
5472 CXXDestructorDecl *Dtor = LookupDestructor(BaseClassDecl);
5473 assert(Dtor && "No dtor found for BaseClassDecl!");
5474 if (CheckDestructorAccess(
5475 ClassDecl->getLocation(), Dtor,
5476 PDiag(diag::err_access_dtor_vbase)
5477 << Context.getTypeDeclType(ClassDecl) << VBase.getType(),
5478 Context.getTypeDeclType(ClassDecl)) ==
5480 CheckDerivedToBaseConversion(
5481 Context.getTypeDeclType(ClassDecl), VBase.getType(),
5482 diag::err_access_dtor_vbase, 0, ClassDecl->getLocation(),
5483 SourceRange(), DeclarationName(), nullptr);
5486 MarkFunctionReferenced(Location, Dtor);
5487 DiagnoseUseOfDecl(Dtor, Location);
5491 void Sema::ActOnDefaultCtorInitializers(Decl *CDtorDecl) {
5495 if (CXXConstructorDecl *Constructor
5496 = dyn_cast<CXXConstructorDecl>(CDtorDecl)) {
5497 SetCtorInitializers(Constructor, /*AnyErrors=*/false);
5498 DiagnoseUninitializedFields(*this, Constructor);
5502 bool Sema::isAbstractType(SourceLocation Loc, QualType T) {
5503 if (!getLangOpts().CPlusPlus)
5506 const auto *RD = Context.getBaseElementType(T)->getAsCXXRecordDecl();
5510 // FIXME: Per [temp.inst]p1, we are supposed to trigger instantiation of a
5511 // class template specialization here, but doing so breaks a lot of code.
5513 // We can't answer whether something is abstract until it has a
5514 // definition. If it's currently being defined, we'll walk back
5515 // over all the declarations when we have a full definition.
5516 const CXXRecordDecl *Def = RD->getDefinition();
5517 if (!Def || Def->isBeingDefined())
5520 return RD->isAbstract();
5523 bool Sema::RequireNonAbstractType(SourceLocation Loc, QualType T,
5524 TypeDiagnoser &Diagnoser) {
5525 if (!isAbstractType(Loc, T))
5528 T = Context.getBaseElementType(T);
5529 Diagnoser.diagnose(*this, Loc, T);
5530 DiagnoseAbstractType(T->getAsCXXRecordDecl());
5534 void Sema::DiagnoseAbstractType(const CXXRecordDecl *RD) {
5535 // Check if we've already emitted the list of pure virtual functions
5537 if (PureVirtualClassDiagSet && PureVirtualClassDiagSet->count(RD))
5540 // If the diagnostic is suppressed, don't emit the notes. We're only
5541 // going to emit them once, so try to attach them to a diagnostic we're
5542 // actually going to show.
5543 if (Diags.isLastDiagnosticIgnored())
5546 CXXFinalOverriderMap FinalOverriders;
5547 RD->getFinalOverriders(FinalOverriders);
5549 // Keep a set of seen pure methods so we won't diagnose the same method
5551 llvm::SmallPtrSet<const CXXMethodDecl *, 8> SeenPureMethods;
5553 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
5554 MEnd = FinalOverriders.end();
5557 for (OverridingMethods::iterator SO = M->second.begin(),
5558 SOEnd = M->second.end();
5559 SO != SOEnd; ++SO) {
5560 // C++ [class.abstract]p4:
5561 // A class is abstract if it contains or inherits at least one
5562 // pure virtual function for which the final overrider is pure
5566 if (SO->second.size() != 1)
5569 if (!SO->second.front().Method->isPure())
5572 if (!SeenPureMethods.insert(SO->second.front().Method).second)
5575 Diag(SO->second.front().Method->getLocation(),
5576 diag::note_pure_virtual_function)
5577 << SO->second.front().Method->getDeclName() << RD->getDeclName();
5581 if (!PureVirtualClassDiagSet)
5582 PureVirtualClassDiagSet.reset(new RecordDeclSetTy);
5583 PureVirtualClassDiagSet->insert(RD);
5587 struct AbstractUsageInfo {
5589 CXXRecordDecl *Record;
5590 CanQualType AbstractType;
5593 AbstractUsageInfo(Sema &S, CXXRecordDecl *Record)
5594 : S(S), Record(Record),
5595 AbstractType(S.Context.getCanonicalType(
5596 S.Context.getTypeDeclType(Record))),
5599 void DiagnoseAbstractType() {
5600 if (Invalid) return;
5601 S.DiagnoseAbstractType(Record);
5605 void CheckType(const NamedDecl *D, TypeLoc TL, Sema::AbstractDiagSelID Sel);
5608 struct CheckAbstractUsage {
5609 AbstractUsageInfo &Info;
5610 const NamedDecl *Ctx;
5612 CheckAbstractUsage(AbstractUsageInfo &Info, const NamedDecl *Ctx)
5613 : Info(Info), Ctx(Ctx) {}
5615 void Visit(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5616 switch (TL.getTypeLocClass()) {
5617 #define ABSTRACT_TYPELOC(CLASS, PARENT)
5618 #define TYPELOC(CLASS, PARENT) \
5619 case TypeLoc::CLASS: Check(TL.castAs<CLASS##TypeLoc>(), Sel); break;
5620 #include "clang/AST/TypeLocNodes.def"
5624 void Check(FunctionProtoTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5625 Visit(TL.getReturnLoc(), Sema::AbstractReturnType);
5626 for (unsigned I = 0, E = TL.getNumParams(); I != E; ++I) {
5627 if (!TL.getParam(I))
5630 TypeSourceInfo *TSI = TL.getParam(I)->getTypeSourceInfo();
5631 if (TSI) Visit(TSI->getTypeLoc(), Sema::AbstractParamType);
5635 void Check(ArrayTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5636 Visit(TL.getElementLoc(), Sema::AbstractArrayType);
5639 void Check(TemplateSpecializationTypeLoc TL, Sema::AbstractDiagSelID Sel) {
5640 // Visit the type parameters from a permissive context.
5641 for (unsigned I = 0, E = TL.getNumArgs(); I != E; ++I) {
5642 TemplateArgumentLoc TAL = TL.getArgLoc(I);
5643 if (TAL.getArgument().getKind() == TemplateArgument::Type)
5644 if (TypeSourceInfo *TSI = TAL.getTypeSourceInfo())
5645 Visit(TSI->getTypeLoc(), Sema::AbstractNone);
5646 // TODO: other template argument types?
5650 // Visit pointee types from a permissive context.
5651 #define CheckPolymorphic(Type) \
5652 void Check(Type TL, Sema::AbstractDiagSelID Sel) { \
5653 Visit(TL.getNextTypeLoc(), Sema::AbstractNone); \
5655 CheckPolymorphic(PointerTypeLoc)
5656 CheckPolymorphic(ReferenceTypeLoc)
5657 CheckPolymorphic(MemberPointerTypeLoc)
5658 CheckPolymorphic(BlockPointerTypeLoc)
5659 CheckPolymorphic(AtomicTypeLoc)
5661 /// Handle all the types we haven't given a more specific
5662 /// implementation for above.
5663 void Check(TypeLoc TL, Sema::AbstractDiagSelID Sel) {
5664 // Every other kind of type that we haven't called out already
5665 // that has an inner type is either (1) sugar or (2) contains that
5666 // inner type in some way as a subobject.
5667 if (TypeLoc Next = TL.getNextTypeLoc())
5668 return Visit(Next, Sel);
5670 // If there's no inner type and we're in a permissive context,
5672 if (Sel == Sema::AbstractNone) return;
5674 // Check whether the type matches the abstract type.
5675 QualType T = TL.getType();
5676 if (T->isArrayType()) {
5677 Sel = Sema::AbstractArrayType;
5678 T = Info.S.Context.getBaseElementType(T);
5680 CanQualType CT = T->getCanonicalTypeUnqualified().getUnqualifiedType();
5681 if (CT != Info.AbstractType) return;
5683 // It matched; do some magic.
5684 if (Sel == Sema::AbstractArrayType) {
5685 Info.S.Diag(Ctx->getLocation(), diag::err_array_of_abstract_type)
5686 << T << TL.getSourceRange();
5688 Info.S.Diag(Ctx->getLocation(), diag::err_abstract_type_in_decl)
5689 << Sel << T << TL.getSourceRange();
5691 Info.DiagnoseAbstractType();
5695 void AbstractUsageInfo::CheckType(const NamedDecl *D, TypeLoc TL,
5696 Sema::AbstractDiagSelID Sel) {
5697 CheckAbstractUsage(*this, D).Visit(TL, Sel);
5702 /// Check for invalid uses of an abstract type in a method declaration.
5703 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5704 CXXMethodDecl *MD) {
5705 // No need to do the check on definitions, which require that
5706 // the return/param types be complete.
5707 if (MD->doesThisDeclarationHaveABody())
5710 // For safety's sake, just ignore it if we don't have type source
5711 // information. This should never happen for non-implicit methods,
5713 if (TypeSourceInfo *TSI = MD->getTypeSourceInfo())
5714 Info.CheckType(MD, TSI->getTypeLoc(), Sema::AbstractNone);
5717 /// Check for invalid uses of an abstract type within a class definition.
5718 static void CheckAbstractClassUsage(AbstractUsageInfo &Info,
5719 CXXRecordDecl *RD) {
5720 for (auto *D : RD->decls()) {
5721 if (D->isImplicit()) continue;
5723 // Methods and method templates.
5724 if (isa<CXXMethodDecl>(D)) {
5725 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(D));
5726 } else if (isa<FunctionTemplateDecl>(D)) {
5727 FunctionDecl *FD = cast<FunctionTemplateDecl>(D)->getTemplatedDecl();
5728 CheckAbstractClassUsage(Info, cast<CXXMethodDecl>(FD));
5730 // Fields and static variables.
5731 } else if (isa<FieldDecl>(D)) {
5732 FieldDecl *FD = cast<FieldDecl>(D);
5733 if (TypeSourceInfo *TSI = FD->getTypeSourceInfo())
5734 Info.CheckType(FD, TSI->getTypeLoc(), Sema::AbstractFieldType);
5735 } else if (isa<VarDecl>(D)) {
5736 VarDecl *VD = cast<VarDecl>(D);
5737 if (TypeSourceInfo *TSI = VD->getTypeSourceInfo())
5738 Info.CheckType(VD, TSI->getTypeLoc(), Sema::AbstractVariableType);
5740 // Nested classes and class templates.
5741 } else if (isa<CXXRecordDecl>(D)) {
5742 CheckAbstractClassUsage(Info, cast<CXXRecordDecl>(D));
5743 } else if (isa<ClassTemplateDecl>(D)) {
5744 CheckAbstractClassUsage(Info,
5745 cast<ClassTemplateDecl>(D)->getTemplatedDecl());
5750 static void ReferenceDllExportedMembers(Sema &S, CXXRecordDecl *Class) {
5751 Attr *ClassAttr = getDLLAttr(Class);
5755 assert(ClassAttr->getKind() == attr::DLLExport);
5757 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5759 if (TSK == TSK_ExplicitInstantiationDeclaration)
5760 // Don't go any further if this is just an explicit instantiation
5764 if (S.Context.getTargetInfo().getTriple().isWindowsGNUEnvironment())
5765 S.MarkVTableUsed(Class->getLocation(), Class, true);
5767 for (Decl *Member : Class->decls()) {
5768 // Defined static variables that are members of an exported base
5769 // class must be marked export too.
5770 auto *VD = dyn_cast<VarDecl>(Member);
5771 if (VD && Member->getAttr<DLLExportAttr>() &&
5772 VD->getStorageClass() == SC_Static &&
5773 TSK == TSK_ImplicitInstantiation)
5774 S.MarkVariableReferenced(VD->getLocation(), VD);
5776 auto *MD = dyn_cast<CXXMethodDecl>(Member);
5780 if (Member->getAttr<DLLExportAttr>()) {
5781 if (MD->isUserProvided()) {
5782 // Instantiate non-default class member functions ...
5784 // .. except for certain kinds of template specializations.
5785 if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
5788 S.MarkFunctionReferenced(Class->getLocation(), MD);
5790 // The function will be passed to the consumer when its definition is
5792 } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
5793 MD->isCopyAssignmentOperator() ||
5794 MD->isMoveAssignmentOperator()) {
5795 // Synthesize and instantiate non-trivial implicit methods, explicitly
5796 // defaulted methods, and the copy and move assignment operators. The
5797 // latter are exported even if they are trivial, because the address of
5798 // an operator can be taken and should compare equal across libraries.
5799 DiagnosticErrorTrap Trap(S.Diags);
5800 S.MarkFunctionReferenced(Class->getLocation(), MD);
5801 if (Trap.hasErrorOccurred()) {
5802 S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
5803 << Class << !S.getLangOpts().CPlusPlus11;
5807 // There is no later point when we will see the definition of this
5808 // function, so pass it to the consumer now.
5809 S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
5815 static void checkForMultipleExportedDefaultConstructors(Sema &S,
5816 CXXRecordDecl *Class) {
5817 // Only the MS ABI has default constructor closures, so we don't need to do
5818 // this semantic checking anywhere else.
5819 if (!S.Context.getTargetInfo().getCXXABI().isMicrosoft())
5822 CXXConstructorDecl *LastExportedDefaultCtor = nullptr;
5823 for (Decl *Member : Class->decls()) {
5824 // Look for exported default constructors.
5825 auto *CD = dyn_cast<CXXConstructorDecl>(Member);
5826 if (!CD || !CD->isDefaultConstructor())
5828 auto *Attr = CD->getAttr<DLLExportAttr>();
5832 // If the class is non-dependent, mark the default arguments as ODR-used so
5833 // that we can properly codegen the constructor closure.
5834 if (!Class->isDependentContext()) {
5835 for (ParmVarDecl *PD : CD->parameters()) {
5836 (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), CD, PD);
5837 S.DiscardCleanupsInEvaluationContext();
5841 if (LastExportedDefaultCtor) {
5842 S.Diag(LastExportedDefaultCtor->getLocation(),
5843 diag::err_attribute_dll_ambiguous_default_ctor)
5845 S.Diag(CD->getLocation(), diag::note_entity_declared_at)
5846 << CD->getDeclName();
5849 LastExportedDefaultCtor = CD;
5853 void Sema::checkClassLevelCodeSegAttribute(CXXRecordDecl *Class) {
5854 // Mark any compiler-generated routines with the implicit code_seg attribute.
5855 for (auto *Method : Class->methods()) {
5856 if (Method->isUserProvided())
5858 if (Attr *A = getImplicitCodeSegOrSectionAttrForFunction(Method, /*IsDefinition=*/true))
5863 /// Check class-level dllimport/dllexport attribute.
5864 void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
5865 Attr *ClassAttr = getDLLAttr(Class);
5867 // MSVC inherits DLL attributes to partial class template specializations.
5868 if (Context.getTargetInfo().getCXXABI().isMicrosoft() && !ClassAttr) {
5869 if (auto *Spec = dyn_cast<ClassTemplatePartialSpecializationDecl>(Class)) {
5870 if (Attr *TemplateAttr =
5871 getDLLAttr(Spec->getSpecializedTemplate()->getTemplatedDecl())) {
5872 auto *A = cast<InheritableAttr>(TemplateAttr->clone(getASTContext()));
5873 A->setInherited(true);
5882 if (!Class->isExternallyVisible()) {
5883 Diag(Class->getLocation(), diag::err_attribute_dll_not_extern)
5884 << Class << ClassAttr;
5888 if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5889 !ClassAttr->isInherited()) {
5890 // Diagnose dll attributes on members of class with dll attribute.
5891 for (Decl *Member : Class->decls()) {
5892 if (!isa<VarDecl>(Member) && !isa<CXXMethodDecl>(Member))
5894 InheritableAttr *MemberAttr = getDLLAttr(Member);
5895 if (!MemberAttr || MemberAttr->isInherited() || Member->isInvalidDecl())
5898 Diag(MemberAttr->getLocation(),
5899 diag::err_attribute_dll_member_of_dll_class)
5900 << MemberAttr << ClassAttr;
5901 Diag(ClassAttr->getLocation(), diag::note_previous_attribute);
5902 Member->setInvalidDecl();
5906 if (Class->getDescribedClassTemplate())
5907 // Don't inherit dll attribute until the template is instantiated.
5910 // The class is either imported or exported.
5911 const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
5913 // Check if this was a dllimport attribute propagated from a derived class to
5914 // a base class template specialization. We don't apply these attributes to
5915 // static data members.
5916 const bool PropagatedImport =
5918 cast<DLLImportAttr>(ClassAttr)->wasPropagatedToBaseTemplate();
5920 TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
5922 // Ignore explicit dllexport on explicit class template instantiation
5923 // declarations, except in MinGW mode.
5924 if (ClassExported && !ClassAttr->isInherited() &&
5925 TSK == TSK_ExplicitInstantiationDeclaration &&
5926 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
5927 Class->dropAttr<DLLExportAttr>();
5931 // Force declaration of implicit members so they can inherit the attribute.
5932 ForceDeclarationOfImplicitMembers(Class);
5934 // FIXME: MSVC's docs say all bases must be exportable, but this doesn't
5935 // seem to be true in practice?
5937 for (Decl *Member : Class->decls()) {
5938 VarDecl *VD = dyn_cast<VarDecl>(Member);
5939 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
5941 // Only methods and static fields inherit the attributes.
5946 // Don't process deleted methods.
5947 if (MD->isDeleted())
5950 if (MD->isInlined()) {
5951 // MinGW does not import or export inline methods. But do it for
5952 // template instantiations.
5953 if (!Context.getTargetInfo().getCXXABI().isMicrosoft() &&
5954 !Context.getTargetInfo().getTriple().isWindowsItaniumEnvironment() &&
5955 TSK != TSK_ExplicitInstantiationDeclaration &&
5956 TSK != TSK_ExplicitInstantiationDefinition)
5959 // MSVC versions before 2015 don't export the move assignment operators
5960 // and move constructor, so don't attempt to import/export them if
5961 // we have a definition.
5962 auto *Ctor = dyn_cast<CXXConstructorDecl>(MD);
5963 if ((MD->isMoveAssignmentOperator() ||
5964 (Ctor && Ctor->isMoveConstructor())) &&
5965 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015))
5968 // MSVC2015 doesn't export trivial defaulted x-tor but copy assign
5969 // operator is exported anyway.
5970 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
5971 (Ctor || isa<CXXDestructorDecl>(MD)) && MD->isTrivial())
5976 // Don't apply dllimport attributes to static data members of class template
5977 // instantiations when the attribute is propagated from a derived class.
5978 if (VD && PropagatedImport)
5981 if (!cast<NamedDecl>(Member)->isExternallyVisible())
5984 if (!getDLLAttr(Member)) {
5985 InheritableAttr *NewAttr = nullptr;
5987 // Do not export/import inline function when -fno-dllexport-inlines is
5988 // passed. But add attribute for later local static var check.
5989 if (!getLangOpts().DllExportInlines && MD && MD->isInlined() &&
5990 TSK != TSK_ExplicitInstantiationDeclaration &&
5991 TSK != TSK_ExplicitInstantiationDefinition) {
5992 if (ClassExported) {
5993 NewAttr = ::new (getASTContext())
5994 DLLExportStaticLocalAttr(getASTContext(), *ClassAttr);
5996 NewAttr = ::new (getASTContext())
5997 DLLImportStaticLocalAttr(getASTContext(), *ClassAttr);
6000 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6003 NewAttr->setInherited(true);
6004 Member->addAttr(NewAttr);
6007 // Propagate DLLAttr to friend re-declarations of MD that have already
6008 // been constructed.
6009 for (FunctionDecl *FD = MD->getMostRecentDecl(); FD;
6010 FD = FD->getPreviousDecl()) {
6011 if (FD->getFriendObjectKind() == Decl::FOK_None)
6013 assert(!getDLLAttr(FD) &&
6014 "friend re-decl should not already have a DLLAttr");
6015 NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6016 NewAttr->setInherited(true);
6017 FD->addAttr(NewAttr);
6024 DelayedDllExportClasses.push_back(Class);
6027 /// Perform propagation of DLL attributes from a derived class to a
6028 /// templated base class for MS compatibility.
6029 void Sema::propagateDLLAttrToBaseClassTemplate(
6030 CXXRecordDecl *Class, Attr *ClassAttr,
6031 ClassTemplateSpecializationDecl *BaseTemplateSpec, SourceLocation BaseLoc) {
6033 BaseTemplateSpec->getSpecializedTemplate()->getTemplatedDecl())) {
6034 // If the base class template has a DLL attribute, don't try to change it.
6038 auto TSK = BaseTemplateSpec->getSpecializationKind();
6039 if (!getDLLAttr(BaseTemplateSpec) &&
6040 (TSK == TSK_Undeclared || TSK == TSK_ExplicitInstantiationDeclaration ||
6041 TSK == TSK_ImplicitInstantiation)) {
6042 // The template hasn't been instantiated yet (or it has, but only as an
6043 // explicit instantiation declaration or implicit instantiation, which means
6044 // we haven't codegenned any members yet), so propagate the attribute.
6045 auto *NewAttr = cast<InheritableAttr>(ClassAttr->clone(getASTContext()));
6046 NewAttr->setInherited(true);
6047 BaseTemplateSpec->addAttr(NewAttr);
6049 // If this was an import, mark that we propagated it from a derived class to
6050 // a base class template specialization.
6051 if (auto *ImportAttr = dyn_cast<DLLImportAttr>(NewAttr))
6052 ImportAttr->setPropagatedToBaseTemplate();
6054 // If the template is already instantiated, checkDLLAttributeRedeclaration()
6055 // needs to be run again to work see the new attribute. Otherwise this will
6056 // get run whenever the template is instantiated.
6057 if (TSK != TSK_Undeclared)
6058 checkClassLevelDLLAttribute(BaseTemplateSpec);
6063 if (getDLLAttr(BaseTemplateSpec)) {
6064 // The template has already been specialized or instantiated with an
6065 // attribute, explicitly or through propagation. We should not try to change
6070 // The template was previously instantiated or explicitly specialized without
6071 // a dll attribute, It's too late for us to add an attribute, so warn that
6072 // this is unsupported.
6073 Diag(BaseLoc, diag::warn_attribute_dll_instantiated_base_class)
6074 << BaseTemplateSpec->isExplicitSpecialization();
6075 Diag(ClassAttr->getLocation(), diag::note_attribute);
6076 if (BaseTemplateSpec->isExplicitSpecialization()) {
6077 Diag(BaseTemplateSpec->getLocation(),
6078 diag::note_template_class_explicit_specialization_was_here)
6079 << BaseTemplateSpec;
6081 Diag(BaseTemplateSpec->getPointOfInstantiation(),
6082 diag::note_template_class_instantiation_was_here)
6083 << BaseTemplateSpec;
6087 static void DefineImplicitSpecialMember(Sema &S, CXXMethodDecl *MD,
6088 SourceLocation DefaultLoc) {
6089 switch (S.getSpecialMember(MD)) {
6090 case Sema::CXXDefaultConstructor:
6091 S.DefineImplicitDefaultConstructor(DefaultLoc,
6092 cast<CXXConstructorDecl>(MD));
6094 case Sema::CXXCopyConstructor:
6095 S.DefineImplicitCopyConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
6097 case Sema::CXXCopyAssignment:
6098 S.DefineImplicitCopyAssignment(DefaultLoc, MD);
6100 case Sema::CXXDestructor:
6101 S.DefineImplicitDestructor(DefaultLoc, cast<CXXDestructorDecl>(MD));
6103 case Sema::CXXMoveConstructor:
6104 S.DefineImplicitMoveConstructor(DefaultLoc, cast<CXXConstructorDecl>(MD));
6106 case Sema::CXXMoveAssignment:
6107 S.DefineImplicitMoveAssignment(DefaultLoc, MD);
6109 case Sema::CXXInvalid:
6110 llvm_unreachable("Invalid special member.");
6114 /// Determine whether a type is permitted to be passed or returned in
6115 /// registers, per C++ [class.temporary]p3.
6116 static bool canPassInRegisters(Sema &S, CXXRecordDecl *D,
6117 TargetInfo::CallingConvKind CCK) {
6118 if (D->isDependentType() || D->isInvalidDecl())
6121 // Clang <= 4 used the pre-C++11 rule, which ignores move operations.
6122 // The PS4 platform ABI follows the behavior of Clang 3.2.
6123 if (CCK == TargetInfo::CCK_ClangABI4OrPS4)
6124 return !D->hasNonTrivialDestructorForCall() &&
6125 !D->hasNonTrivialCopyConstructorForCall();
6127 if (CCK == TargetInfo::CCK_MicrosoftWin64) {
6128 bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
6129 bool DtorIsTrivialForCall = false;
6131 // If a class has at least one non-deleted, trivial copy constructor, it
6132 // is passed according to the C ABI. Otherwise, it is passed indirectly.
6134 // Note: This permits classes with non-trivial copy or move ctors to be
6135 // passed in registers, so long as they *also* have a trivial copy ctor,
6136 // which is non-conforming.
6137 if (D->needsImplicitCopyConstructor()) {
6138 if (!D->defaultedCopyConstructorIsDeleted()) {
6139 if (D->hasTrivialCopyConstructor())
6140 CopyCtorIsTrivial = true;
6141 if (D->hasTrivialCopyConstructorForCall())
6142 CopyCtorIsTrivialForCall = true;
6145 for (const CXXConstructorDecl *CD : D->ctors()) {
6146 if (CD->isCopyConstructor() && !CD->isDeleted()) {
6147 if (CD->isTrivial())
6148 CopyCtorIsTrivial = true;
6149 if (CD->isTrivialForCall())
6150 CopyCtorIsTrivialForCall = true;
6155 if (D->needsImplicitDestructor()) {
6156 if (!D->defaultedDestructorIsDeleted() &&
6157 D->hasTrivialDestructorForCall())
6158 DtorIsTrivialForCall = true;
6159 } else if (const auto *DD = D->getDestructor()) {
6160 if (!DD->isDeleted() && DD->isTrivialForCall())
6161 DtorIsTrivialForCall = true;
6164 // If the copy ctor and dtor are both trivial-for-calls, pass direct.
6165 if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
6168 // If a class has a destructor, we'd really like to pass it indirectly
6169 // because it allows us to elide copies. Unfortunately, MSVC makes that
6170 // impossible for small types, which it will pass in a single register or
6171 // stack slot. Most objects with dtors are large-ish, so handle that early.
6172 // We can't call out all large objects as being indirect because there are
6173 // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
6174 // how we pass large POD types.
6176 // Note: This permits small classes with nontrivial destructors to be
6177 // passed in registers, which is non-conforming.
6178 bool isAArch64 = S.Context.getTargetInfo().getTriple().isAArch64();
6179 uint64_t TypeSize = isAArch64 ? 128 : 64;
6181 if (CopyCtorIsTrivial &&
6182 S.getASTContext().getTypeSize(D->getTypeForDecl()) <= TypeSize)
6187 // Per C++ [class.temporary]p3, the relevant condition is:
6188 // each copy constructor, move constructor, and destructor of X is
6189 // either trivial or deleted, and X has at least one non-deleted copy
6190 // or move constructor
6191 bool HasNonDeletedCopyOrMove = false;
6193 if (D->needsImplicitCopyConstructor() &&
6194 !D->defaultedCopyConstructorIsDeleted()) {
6195 if (!D->hasTrivialCopyConstructorForCall())
6197 HasNonDeletedCopyOrMove = true;
6200 if (S.getLangOpts().CPlusPlus11 && D->needsImplicitMoveConstructor() &&
6201 !D->defaultedMoveConstructorIsDeleted()) {
6202 if (!D->hasTrivialMoveConstructorForCall())
6204 HasNonDeletedCopyOrMove = true;
6207 if (D->needsImplicitDestructor() && !D->defaultedDestructorIsDeleted() &&
6208 !D->hasTrivialDestructorForCall())
6211 for (const CXXMethodDecl *MD : D->methods()) {
6212 if (MD->isDeleted())
6215 auto *CD = dyn_cast<CXXConstructorDecl>(MD);
6216 if (CD && CD->isCopyOrMoveConstructor())
6217 HasNonDeletedCopyOrMove = true;
6218 else if (!isa<CXXDestructorDecl>(MD))
6221 if (!MD->isTrivialForCall())
6225 return HasNonDeletedCopyOrMove;
6228 /// Perform semantic checks on a class definition that has been
6229 /// completing, introducing implicitly-declared members, checking for
6230 /// abstract types, etc.
6231 void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
6235 if (Record->isAbstract() && !Record->isInvalidDecl()) {
6236 AbstractUsageInfo Info(*this, Record);
6237 CheckAbstractClassUsage(Info, Record);
6240 // If this is not an aggregate type and has no user-declared constructor,
6241 // complain about any non-static data members of reference or const scalar
6242 // type, since they will never get initializers.
6243 if (!Record->isInvalidDecl() && !Record->isDependentType() &&
6244 !Record->isAggregate() && !Record->hasUserDeclaredConstructor() &&
6245 !Record->isLambda()) {
6246 bool Complained = false;
6247 for (const auto *F : Record->fields()) {
6248 if (F->hasInClassInitializer() || F->isUnnamedBitfield())
6251 if (F->getType()->isReferenceType() ||
6252 (F->getType().isConstQualified() && F->getType()->isScalarType())) {
6254 Diag(Record->getLocation(), diag::warn_no_constructor_for_refconst)
6255 << Record->getTagKind() << Record;
6259 Diag(F->getLocation(), diag::note_refconst_member_not_initialized)
6260 << F->getType()->isReferenceType()
6261 << F->getDeclName();
6266 if (Record->getIdentifier()) {
6267 // C++ [class.mem]p13:
6268 // If T is the name of a class, then each of the following shall have a
6269 // name different from T:
6270 // - every member of every anonymous union that is a member of class T.
6272 // C++ [class.mem]p14:
6273 // In addition, if class T has a user-declared constructor (12.1), every
6274 // non-static data member of class T shall have a name different from T.
6275 DeclContext::lookup_result R = Record->lookup(Record->getDeclName());
6276 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E;
6278 NamedDecl *D = (*I)->getUnderlyingDecl();
6279 if (((isa<FieldDecl>(D) || isa<UnresolvedUsingValueDecl>(D)) &&
6280 Record->hasUserDeclaredConstructor()) ||
6281 isa<IndirectFieldDecl>(D)) {
6282 Diag((*I)->getLocation(), diag::err_member_name_of_class)
6283 << D->getDeclName();
6289 // Warn if the class has virtual methods but non-virtual public destructor.
6290 if (Record->isPolymorphic() && !Record->isDependentType()) {
6291 CXXDestructorDecl *dtor = Record->getDestructor();
6292 if ((!dtor || (!dtor->isVirtual() && dtor->getAccess() == AS_public)) &&
6293 !Record->hasAttr<FinalAttr>())
6294 Diag(dtor ? dtor->getLocation() : Record->getLocation(),
6295 diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
6298 if (Record->isAbstract()) {
6299 if (FinalAttr *FA = Record->getAttr<FinalAttr>()) {
6300 Diag(Record->getLocation(), diag::warn_abstract_final_class)
6301 << FA->isSpelledAsSealed();
6302 DiagnoseAbstractType(Record);
6306 // Warn if the class has a final destructor but is not itself marked final.
6307 if (!Record->hasAttr<FinalAttr>()) {
6308 if (const CXXDestructorDecl *dtor = Record->getDestructor()) {
6309 if (const FinalAttr *FA = dtor->getAttr<FinalAttr>()) {
6310 Diag(FA->getLocation(), diag::warn_final_dtor_non_final_class)
6311 << FA->isSpelledAsSealed()
6312 << FixItHint::CreateInsertion(
6313 getLocForEndOfToken(Record->getLocation()),
6314 (FA->isSpelledAsSealed() ? " sealed" : " final"));
6315 Diag(Record->getLocation(),
6316 diag::note_final_dtor_non_final_class_silence)
6317 << Context.getRecordType(Record) << FA->isSpelledAsSealed();
6322 // See if trivial_abi has to be dropped.
6323 if (Record->hasAttr<TrivialABIAttr>())
6324 checkIllFormedTrivialABIStruct(*Record);
6326 // Set HasTrivialSpecialMemberForCall if the record has attribute
6328 bool HasTrivialABI = Record->hasAttr<TrivialABIAttr>();
6331 Record->setHasTrivialSpecialMemberForCall();
6333 auto CompleteMemberFunction = [&](CXXMethodDecl *M) {
6334 // Check whether the explicitly-defaulted special members are valid.
6335 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted())
6336 CheckExplicitlyDefaultedSpecialMember(M);
6338 // For an explicitly defaulted or deleted special member, we defer
6339 // determining triviality until the class is complete. That time is now!
6340 CXXSpecialMember CSM = getSpecialMember(M);
6341 if (!M->isImplicit() && !M->isUserProvided()) {
6342 if (CSM != CXXInvalid) {
6343 M->setTrivial(SpecialMemberIsTrivial(M, CSM));
6344 // Inform the class that we've finished declaring this member.
6345 Record->finishedDefaultedOrDeletedMember(M);
6346 M->setTrivialForCall(
6348 SpecialMemberIsTrivial(M, CSM, TAH_ConsiderTrivialABI));
6349 Record->setTrivialForCallFlags(M);
6353 // Set triviality for the purpose of calls if this is a user-provided
6354 // copy/move constructor or destructor.
6355 if ((CSM == CXXCopyConstructor || CSM == CXXMoveConstructor ||
6356 CSM == CXXDestructor) && M->isUserProvided()) {
6357 M->setTrivialForCall(HasTrivialABI);
6358 Record->setTrivialForCallFlags(M);
6361 if (!M->isInvalidDecl() && M->isExplicitlyDefaulted() &&
6362 M->hasAttr<DLLExportAttr>()) {
6363 if (getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
6365 (CSM == CXXDefaultConstructor || CSM == CXXCopyConstructor ||
6366 CSM == CXXDestructor))
6367 M->dropAttr<DLLExportAttr>();
6369 if (M->hasAttr<DLLExportAttr>()) {
6370 // Define after any fields with in-class initializers have been parsed.
6371 DelayedDllExportMemberFunctions.push_back(M);
6375 // Define defaulted constexpr virtual functions that override a base class
6376 // function right away.
6377 // FIXME: We can defer doing this until the vtable is marked as used.
6378 if (M->isDefaulted() && M->isConstexpr() && M->size_overridden_methods())
6379 DefineImplicitSpecialMember(*this, M, M->getLocation());
6382 bool HasMethodWithOverrideControl = false,
6383 HasOverridingMethodWithoutOverrideControl = false;
6384 if (!Record->isDependentType()) {
6385 // Check the destructor before any other member function. We need to
6386 // determine whether it's trivial in order to determine whether the claas
6387 // type is a literal type, which is a prerequisite for determining whether
6388 // other special member functions are valid and whether they're implicitly
6390 if (CXXDestructorDecl *Dtor = Record->getDestructor())
6391 CompleteMemberFunction(Dtor);
6393 for (auto *M : Record->methods()) {
6394 // See if a method overloads virtual methods in a base
6395 // class without overriding any.
6397 DiagnoseHiddenVirtualMethods(M);
6398 if (M->hasAttr<OverrideAttr>())
6399 HasMethodWithOverrideControl = true;
6400 else if (M->size_overridden_methods() > 0)
6401 HasOverridingMethodWithoutOverrideControl = true;
6403 if (!isa<CXXDestructorDecl>(M))
6404 CompleteMemberFunction(M);
6408 if (HasMethodWithOverrideControl &&
6409 HasOverridingMethodWithoutOverrideControl) {
6410 // At least one method has the 'override' control declared.
6411 // Diagnose all other overridden methods which do not have 'override' specified on them.
6412 for (auto *M : Record->methods())
6413 DiagnoseAbsenceOfOverrideControl(M);
6416 // ms_struct is a request to use the same ABI rules as MSVC. Check
6417 // whether this class uses any C++ features that are implemented
6418 // completely differently in MSVC, and if so, emit a diagnostic.
6419 // That diagnostic defaults to an error, but we allow projects to
6420 // map it down to a warning (or ignore it). It's a fairly common
6421 // practice among users of the ms_struct pragma to mass-annotate
6422 // headers, sweeping up a bunch of types that the project doesn't
6423 // really rely on MSVC-compatible layout for. We must therefore
6424 // support "ms_struct except for C++ stuff" as a secondary ABI.
6425 if (Record->isMsStruct(Context) &&
6426 (Record->isPolymorphic() || Record->getNumBases())) {
6427 Diag(Record->getLocation(), diag::warn_cxx_ms_struct);
6430 checkClassLevelDLLAttribute(Record);
6431 checkClassLevelCodeSegAttribute(Record);
6433 bool ClangABICompat4 =
6434 Context.getLangOpts().getClangABICompat() <= LangOptions::ClangABI::Ver4;
6435 TargetInfo::CallingConvKind CCK =
6436 Context.getTargetInfo().getCallingConvKind(ClangABICompat4);
6437 bool CanPass = canPassInRegisters(*this, Record, CCK);
6439 // Do not change ArgPassingRestrictions if it has already been set to
6440 // APK_CanNeverPassInRegs.
6441 if (Record->getArgPassingRestrictions() != RecordDecl::APK_CanNeverPassInRegs)
6442 Record->setArgPassingRestrictions(CanPass
6443 ? RecordDecl::APK_CanPassInRegs
6444 : RecordDecl::APK_CannotPassInRegs);
6446 // If canPassInRegisters returns true despite the record having a non-trivial
6447 // destructor, the record is destructed in the callee. This happens only when
6448 // the record or one of its subobjects has a field annotated with trivial_abi
6449 // or a field qualified with ObjC __strong/__weak.
6450 if (Context.getTargetInfo().getCXXABI().areArgsDestroyedLeftToRightInCallee())
6451 Record->setParamDestroyedInCallee(true);
6452 else if (Record->hasNonTrivialDestructor())
6453 Record->setParamDestroyedInCallee(CanPass);
6455 if (getLangOpts().ForceEmitVTables) {
6456 // If we want to emit all the vtables, we need to mark it as used. This
6457 // is especially required for cases like vtable assumption loads.
6458 MarkVTableUsed(Record->getInnerLocStart(), Record);
6462 /// Look up the special member function that would be called by a special
6463 /// member function for a subobject of class type.
6465 /// \param Class The class type of the subobject.
6466 /// \param CSM The kind of special member function.
6467 /// \param FieldQuals If the subobject is a field, its cv-qualifiers.
6468 /// \param ConstRHS True if this is a copy operation with a const object
6469 /// on its RHS, that is, if the argument to the outer special member
6470 /// function is 'const' and this is not a field marked 'mutable'.
6471 static Sema::SpecialMemberOverloadResult lookupCallFromSpecialMember(
6472 Sema &S, CXXRecordDecl *Class, Sema::CXXSpecialMember CSM,
6473 unsigned FieldQuals, bool ConstRHS) {
6474 unsigned LHSQuals = 0;
6475 if (CSM == Sema::CXXCopyAssignment || CSM == Sema::CXXMoveAssignment)
6476 LHSQuals = FieldQuals;
6478 unsigned RHSQuals = FieldQuals;
6479 if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
6482 RHSQuals |= Qualifiers::Const;
6484 return S.LookupSpecialMember(Class, CSM,
6485 RHSQuals & Qualifiers::Const,
6486 RHSQuals & Qualifiers::Volatile,
6488 LHSQuals & Qualifiers::Const,
6489 LHSQuals & Qualifiers::Volatile);
6492 class Sema::InheritedConstructorInfo {
6494 SourceLocation UseLoc;
6496 /// A mapping from the base classes through which the constructor was
6497 /// inherited to the using shadow declaration in that base class (or a null
6498 /// pointer if the constructor was declared in that base class).
6499 llvm::DenseMap<CXXRecordDecl *, ConstructorUsingShadowDecl *>
6503 InheritedConstructorInfo(Sema &S, SourceLocation UseLoc,
6504 ConstructorUsingShadowDecl *Shadow)
6505 : S(S), UseLoc(UseLoc) {
6506 bool DiagnosedMultipleConstructedBases = false;
6507 CXXRecordDecl *ConstructedBase = nullptr;
6508 UsingDecl *ConstructedBaseUsing = nullptr;
6510 // Find the set of such base class subobjects and check that there's a
6511 // unique constructed subobject.
6512 for (auto *D : Shadow->redecls()) {
6513 auto *DShadow = cast<ConstructorUsingShadowDecl>(D);
6514 auto *DNominatedBase = DShadow->getNominatedBaseClass();
6515 auto *DConstructedBase = DShadow->getConstructedBaseClass();
6517 InheritedFromBases.insert(
6518 std::make_pair(DNominatedBase->getCanonicalDecl(),
6519 DShadow->getNominatedBaseClassShadowDecl()));
6520 if (DShadow->constructsVirtualBase())
6521 InheritedFromBases.insert(
6522 std::make_pair(DConstructedBase->getCanonicalDecl(),
6523 DShadow->getConstructedBaseClassShadowDecl()));
6525 assert(DNominatedBase == DConstructedBase);
6527 // [class.inhctor.init]p2:
6528 // If the constructor was inherited from multiple base class subobjects
6529 // of type B, the program is ill-formed.
6530 if (!ConstructedBase) {
6531 ConstructedBase = DConstructedBase;
6532 ConstructedBaseUsing = D->getUsingDecl();
6533 } else if (ConstructedBase != DConstructedBase &&
6534 !Shadow->isInvalidDecl()) {
6535 if (!DiagnosedMultipleConstructedBases) {
6536 S.Diag(UseLoc, diag::err_ambiguous_inherited_constructor)
6537 << Shadow->getTargetDecl();
6538 S.Diag(ConstructedBaseUsing->getLocation(),
6539 diag::note_ambiguous_inherited_constructor_using)
6541 DiagnosedMultipleConstructedBases = true;
6543 S.Diag(D->getUsingDecl()->getLocation(),
6544 diag::note_ambiguous_inherited_constructor_using)
6545 << DConstructedBase;
6549 if (DiagnosedMultipleConstructedBases)
6550 Shadow->setInvalidDecl();
6553 /// Find the constructor to use for inherited construction of a base class,
6554 /// and whether that base class constructor inherits the constructor from a
6555 /// virtual base class (in which case it won't actually invoke it).
6556 std::pair<CXXConstructorDecl *, bool>
6557 findConstructorForBase(CXXRecordDecl *Base, CXXConstructorDecl *Ctor) const {
6558 auto It = InheritedFromBases.find(Base->getCanonicalDecl());
6559 if (It == InheritedFromBases.end())
6560 return std::make_pair(nullptr, false);
6562 // This is an intermediary class.
6564 return std::make_pair(
6565 S.findInheritingConstructor(UseLoc, Ctor, It->second),
6566 It->second->constructsVirtualBase());
6568 // This is the base class from which the constructor was inherited.
6569 return std::make_pair(Ctor, false);
6573 /// Is the special member function which would be selected to perform the
6574 /// specified operation on the specified class type a constexpr constructor?
6576 specialMemberIsConstexpr(Sema &S, CXXRecordDecl *ClassDecl,
6577 Sema::CXXSpecialMember CSM, unsigned Quals,
6579 CXXConstructorDecl *InheritedCtor = nullptr,
6580 Sema::InheritedConstructorInfo *Inherited = nullptr) {
6581 // If we're inheriting a constructor, see if we need to call it for this base
6583 if (InheritedCtor) {
6584 assert(CSM == Sema::CXXDefaultConstructor);
6586 Inherited->findConstructorForBase(ClassDecl, InheritedCtor).first;
6588 return BaseCtor->isConstexpr();
6591 if (CSM == Sema::CXXDefaultConstructor)
6592 return ClassDecl->hasConstexprDefaultConstructor();
6593 if (CSM == Sema::CXXDestructor)
6594 return ClassDecl->hasConstexprDestructor();
6596 Sema::SpecialMemberOverloadResult SMOR =
6597 lookupCallFromSpecialMember(S, ClassDecl, CSM, Quals, ConstRHS);
6598 if (!SMOR.getMethod())
6599 // A constructor we wouldn't select can't be "involved in initializing"
6602 return SMOR.getMethod()->isConstexpr();
6605 /// Determine whether the specified special member function would be constexpr
6606 /// if it were implicitly defined.
6607 static bool defaultedSpecialMemberIsConstexpr(
6608 Sema &S, CXXRecordDecl *ClassDecl, Sema::CXXSpecialMember CSM,
6609 bool ConstArg, CXXConstructorDecl *InheritedCtor = nullptr,
6610 Sema::InheritedConstructorInfo *Inherited = nullptr) {
6611 if (!S.getLangOpts().CPlusPlus11)
6614 // C++11 [dcl.constexpr]p4:
6615 // In the definition of a constexpr constructor [...]
6618 case Sema::CXXDefaultConstructor:
6621 // Since default constructor lookup is essentially trivial (and cannot
6622 // involve, for instance, template instantiation), we compute whether a
6623 // defaulted default constructor is constexpr directly within CXXRecordDecl.
6625 // This is important for performance; we need to know whether the default
6626 // constructor is constexpr to determine whether the type is a literal type.
6627 return ClassDecl->defaultedDefaultConstructorIsConstexpr();
6629 case Sema::CXXCopyConstructor:
6630 case Sema::CXXMoveConstructor:
6631 // For copy or move constructors, we need to perform overload resolution.
6634 case Sema::CXXCopyAssignment:
6635 case Sema::CXXMoveAssignment:
6636 if (!S.getLangOpts().CPlusPlus14)
6638 // In C++1y, we need to perform overload resolution.
6642 case Sema::CXXDestructor:
6643 return ClassDecl->defaultedDestructorIsConstexpr();
6645 case Sema::CXXInvalid:
6649 // -- if the class is a non-empty union, or for each non-empty anonymous
6650 // union member of a non-union class, exactly one non-static data member
6651 // shall be initialized; [DR1359]
6653 // If we squint, this is guaranteed, since exactly one non-static data member
6654 // will be initialized (if the constructor isn't deleted), we just don't know
6656 if (Ctor && ClassDecl->isUnion())
6657 return CSM == Sema::CXXDefaultConstructor
6658 ? ClassDecl->hasInClassInitializer() ||
6659 !ClassDecl->hasVariantMembers()
6662 // -- the class shall not have any virtual base classes;
6663 if (Ctor && ClassDecl->getNumVBases())
6666 // C++1y [class.copy]p26:
6667 // -- [the class] is a literal type, and
6668 if (!Ctor && !ClassDecl->isLiteral())
6671 // -- every constructor involved in initializing [...] base class
6672 // sub-objects shall be a constexpr constructor;
6673 // -- the assignment operator selected to copy/move each direct base
6674 // class is a constexpr function, and
6675 for (const auto &B : ClassDecl->bases()) {
6676 const RecordType *BaseType = B.getType()->getAs<RecordType>();
6677 if (!BaseType) continue;
6679 CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseType->getDecl());
6680 if (!specialMemberIsConstexpr(S, BaseClassDecl, CSM, 0, ConstArg,
6681 InheritedCtor, Inherited))
6685 // -- every constructor involved in initializing non-static data members
6686 // [...] shall be a constexpr constructor;
6687 // -- every non-static data member and base class sub-object shall be
6689 // -- for each non-static data member of X that is of class type (or array
6690 // thereof), the assignment operator selected to copy/move that member is
6691 // a constexpr function
6692 for (const auto *F : ClassDecl->fields()) {
6693 if (F->isInvalidDecl())
6695 if (CSM == Sema::CXXDefaultConstructor && F->hasInClassInitializer())
6697 QualType BaseType = S.Context.getBaseElementType(F->getType());
6698 if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) {
6699 CXXRecordDecl *FieldRecDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
6700 if (!specialMemberIsConstexpr(S, FieldRecDecl, CSM,
6701 BaseType.getCVRQualifiers(),
6702 ConstArg && !F->isMutable()))
6704 } else if (CSM == Sema::CXXDefaultConstructor) {
6709 // All OK, it's constexpr!
6713 static Sema::ImplicitExceptionSpecification
6714 ComputeDefaultedSpecialMemberExceptionSpec(
6715 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
6716 Sema::InheritedConstructorInfo *ICI);
6718 static Sema::ImplicitExceptionSpecification
6719 computeImplicitExceptionSpec(Sema &S, SourceLocation Loc, CXXMethodDecl *MD) {
6720 auto CSM = S.getSpecialMember(MD);
6721 if (CSM != Sema::CXXInvalid)
6722 return ComputeDefaultedSpecialMemberExceptionSpec(S, Loc, MD, CSM, nullptr);
6724 auto *CD = cast<CXXConstructorDecl>(MD);
6725 assert(CD->getInheritedConstructor() &&
6726 "only special members have implicit exception specs");
6727 Sema::InheritedConstructorInfo ICI(
6728 S, Loc, CD->getInheritedConstructor().getShadowDecl());
6729 return ComputeDefaultedSpecialMemberExceptionSpec(
6730 S, Loc, CD, Sema::CXXDefaultConstructor, &ICI);
6733 static FunctionProtoType::ExtProtoInfo getImplicitMethodEPI(Sema &S,
6734 CXXMethodDecl *MD) {
6735 FunctionProtoType::ExtProtoInfo EPI;
6737 // Build an exception specification pointing back at this member.
6738 EPI.ExceptionSpec.Type = EST_Unevaluated;
6739 EPI.ExceptionSpec.SourceDecl = MD;
6741 // Set the calling convention to the default for C++ instance methods.
6742 EPI.ExtInfo = EPI.ExtInfo.withCallingConv(
6743 S.Context.getDefaultCallingConvention(/*IsVariadic=*/false,
6744 /*IsCXXMethod=*/true));
6748 void Sema::EvaluateImplicitExceptionSpec(SourceLocation Loc, CXXMethodDecl *MD) {
6749 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
6750 if (FPT->getExceptionSpecType() != EST_Unevaluated)
6753 // Evaluate the exception specification.
6754 auto IES = computeImplicitExceptionSpec(*this, Loc, MD);
6755 auto ESI = IES.getExceptionSpec();
6757 // Update the type of the special member to use it.
6758 UpdateExceptionSpec(MD, ESI);
6760 // A user-provided destructor can be defined outside the class. When that
6761 // happens, be sure to update the exception specification on both
6763 const FunctionProtoType *CanonicalFPT =
6764 MD->getCanonicalDecl()->getType()->castAs<FunctionProtoType>();
6765 if (CanonicalFPT->getExceptionSpecType() == EST_Unevaluated)
6766 UpdateExceptionSpec(MD->getCanonicalDecl(), ESI);
6769 void Sema::CheckExplicitlyDefaultedSpecialMember(CXXMethodDecl *MD) {
6770 CXXRecordDecl *RD = MD->getParent();
6771 CXXSpecialMember CSM = getSpecialMember(MD);
6773 assert(MD->isExplicitlyDefaulted() && CSM != CXXInvalid &&
6774 "not an explicitly-defaulted special member");
6776 // Whether this was the first-declared instance of the constructor.
6777 // This affects whether we implicitly add an exception spec and constexpr.
6778 bool First = MD == MD->getCanonicalDecl();
6780 bool HadError = false;
6782 // C++11 [dcl.fct.def.default]p1:
6783 // A function that is explicitly defaulted shall
6784 // -- be a special member function (checked elsewhere),
6785 // -- have the same type (except for ref-qualifiers, and except that a
6786 // copy operation can take a non-const reference) as an implicit
6788 // -- not have default arguments.
6789 // C++2a changes the second bullet to instead delete the function if it's
6790 // defaulted on its first declaration, unless it's "an assignment operator,
6791 // and its return type differs or its parameter type is not a reference".
6792 bool DeleteOnTypeMismatch = getLangOpts().CPlusPlus2a && First;
6793 bool ShouldDeleteForTypeMismatch = false;
6794 unsigned ExpectedParams = 1;
6795 if (CSM == CXXDefaultConstructor || CSM == CXXDestructor)
6797 if (MD->getNumParams() != ExpectedParams) {
6798 // This checks for default arguments: a copy or move constructor with a
6799 // default argument is classified as a default constructor, and assignment
6800 // operations and destructors can't have default arguments.
6801 Diag(MD->getLocation(), diag::err_defaulted_special_member_params)
6802 << CSM << MD->getSourceRange();
6804 } else if (MD->isVariadic()) {
6805 if (DeleteOnTypeMismatch)
6806 ShouldDeleteForTypeMismatch = true;
6808 Diag(MD->getLocation(), diag::err_defaulted_special_member_variadic)
6809 << CSM << MD->getSourceRange();
6814 const FunctionProtoType *Type = MD->getType()->getAs<FunctionProtoType>();
6816 bool CanHaveConstParam = false;
6817 if (CSM == CXXCopyConstructor)
6818 CanHaveConstParam = RD->implicitCopyConstructorHasConstParam();
6819 else if (CSM == CXXCopyAssignment)
6820 CanHaveConstParam = RD->implicitCopyAssignmentHasConstParam();
6822 QualType ReturnType = Context.VoidTy;
6823 if (CSM == CXXCopyAssignment || CSM == CXXMoveAssignment) {
6824 // Check for return type matching.
6825 ReturnType = Type->getReturnType();
6827 QualType DeclType = Context.getTypeDeclType(RD);
6828 DeclType = Context.getAddrSpaceQualType(DeclType, MD->getMethodQualifiers().getAddressSpace());
6829 QualType ExpectedReturnType = Context.getLValueReferenceType(DeclType);
6831 if (!Context.hasSameType(ReturnType, ExpectedReturnType)) {
6832 Diag(MD->getLocation(), diag::err_defaulted_special_member_return_type)
6833 << (CSM == CXXMoveAssignment) << ExpectedReturnType;
6837 // A defaulted special member cannot have cv-qualifiers.
6838 if (Type->getMethodQuals().hasConst() || Type->getMethodQuals().hasVolatile()) {
6839 if (DeleteOnTypeMismatch)
6840 ShouldDeleteForTypeMismatch = true;
6842 Diag(MD->getLocation(), diag::err_defaulted_special_member_quals)
6843 << (CSM == CXXMoveAssignment) << getLangOpts().CPlusPlus14;
6849 // Check for parameter type matching.
6850 QualType ArgType = ExpectedParams ? Type->getParamType(0) : QualType();
6851 bool HasConstParam = false;
6852 if (ExpectedParams && ArgType->isReferenceType()) {
6853 // Argument must be reference to possibly-const T.
6854 QualType ReferentType = ArgType->getPointeeType();
6855 HasConstParam = ReferentType.isConstQualified();
6857 if (ReferentType.isVolatileQualified()) {
6858 if (DeleteOnTypeMismatch)
6859 ShouldDeleteForTypeMismatch = true;
6861 Diag(MD->getLocation(),
6862 diag::err_defaulted_special_member_volatile_param) << CSM;
6867 if (HasConstParam && !CanHaveConstParam) {
6868 if (DeleteOnTypeMismatch)
6869 ShouldDeleteForTypeMismatch = true;
6870 else if (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment) {
6871 Diag(MD->getLocation(),
6872 diag::err_defaulted_special_member_copy_const_param)
6873 << (CSM == CXXCopyAssignment);
6874 // FIXME: Explain why this special member can't be const.
6877 Diag(MD->getLocation(),
6878 diag::err_defaulted_special_member_move_const_param)
6879 << (CSM == CXXMoveAssignment);
6883 } else if (ExpectedParams) {
6884 // A copy assignment operator can take its argument by value, but a
6885 // defaulted one cannot.
6886 assert(CSM == CXXCopyAssignment && "unexpected non-ref argument");
6887 Diag(MD->getLocation(), diag::err_defaulted_copy_assign_not_ref);
6891 // C++11 [dcl.fct.def.default]p2:
6892 // An explicitly-defaulted function may be declared constexpr only if it
6893 // would have been implicitly declared as constexpr,
6894 // Do not apply this rule to members of class templates, since core issue 1358
6895 // makes such functions always instantiate to constexpr functions. For
6896 // functions which cannot be constexpr (for non-constructors in C++11 and for
6897 // destructors in C++14 and C++17), this is checked elsewhere.
6899 // FIXME: This should not apply if the member is deleted.
6900 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, RD, CSM,
6902 if ((getLangOpts().CPlusPlus2a ||
6903 (getLangOpts().CPlusPlus14 ? !isa<CXXDestructorDecl>(MD)
6904 : isa<CXXConstructorDecl>(MD))) &&
6905 MD->isConstexpr() && !Constexpr &&
6906 MD->getTemplatedKind() == FunctionDecl::TK_NonTemplate) {
6907 Diag(MD->getBeginLoc(), MD->isConsteval()
6908 ? diag::err_incorrect_defaulted_consteval
6909 : diag::err_incorrect_defaulted_constexpr)
6911 // FIXME: Explain why the special member can't be constexpr.
6916 // C++2a [dcl.fct.def.default]p3:
6917 // If a function is explicitly defaulted on its first declaration, it is
6918 // implicitly considered to be constexpr if the implicit declaration
6920 MD->setConstexprKind(Constexpr ? CSK_constexpr : CSK_unspecified);
6922 if (!Type->hasExceptionSpec()) {
6923 // C++2a [except.spec]p3:
6924 // If a declaration of a function does not have a noexcept-specifier
6925 // [and] is defaulted on its first declaration, [...] the exception
6926 // specification is as specified below
6927 FunctionProtoType::ExtProtoInfo EPI = Type->getExtProtoInfo();
6928 EPI.ExceptionSpec.Type = EST_Unevaluated;
6929 EPI.ExceptionSpec.SourceDecl = MD;
6930 MD->setType(Context.getFunctionType(ReturnType,
6931 llvm::makeArrayRef(&ArgType,
6937 if (ShouldDeleteForTypeMismatch || ShouldDeleteSpecialMember(MD, CSM)) {
6939 SetDeclDeleted(MD, MD->getLocation());
6940 if (!inTemplateInstantiation() && !HadError) {
6941 Diag(MD->getLocation(), diag::warn_defaulted_method_deleted) << CSM;
6942 if (ShouldDeleteForTypeMismatch) {
6943 Diag(MD->getLocation(), diag::note_deleted_type_mismatch) << CSM;
6945 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
6948 if (ShouldDeleteForTypeMismatch && !HadError) {
6949 Diag(MD->getLocation(),
6950 diag::warn_cxx17_compat_defaulted_method_type_mismatch) << CSM;
6953 // C++11 [dcl.fct.def.default]p4:
6954 // [For a] user-provided explicitly-defaulted function [...] if such a
6955 // function is implicitly defined as deleted, the program is ill-formed.
6956 Diag(MD->getLocation(), diag::err_out_of_line_default_deletes) << CSM;
6957 assert(!ShouldDeleteForTypeMismatch && "deleted non-first decl");
6958 ShouldDeleteSpecialMember(MD, CSM, nullptr, /*Diagnose*/true);
6964 MD->setInvalidDecl();
6967 void Sema::CheckDelayedMemberExceptionSpecs() {
6968 decltype(DelayedOverridingExceptionSpecChecks) Overriding;
6969 decltype(DelayedEquivalentExceptionSpecChecks) Equivalent;
6971 std::swap(Overriding, DelayedOverridingExceptionSpecChecks);
6972 std::swap(Equivalent, DelayedEquivalentExceptionSpecChecks);
6974 // Perform any deferred checking of exception specifications for virtual
6976 for (auto &Check : Overriding)
6977 CheckOverridingFunctionExceptionSpec(Check.first, Check.second);
6979 // Perform any deferred checking of exception specifications for befriended
6981 for (auto &Check : Equivalent)
6982 CheckEquivalentExceptionSpec(Check.second, Check.first);
6986 /// CRTP base class for visiting operations performed by a special member
6987 /// function (or inherited constructor).
6988 template<typename Derived>
6989 struct SpecialMemberVisitor {
6992 Sema::CXXSpecialMember CSM;
6993 Sema::InheritedConstructorInfo *ICI;
6995 // Properties of the special member, computed for convenience.
6996 bool IsConstructor = false, IsAssignment = false, ConstArg = false;
6998 SpecialMemberVisitor(Sema &S, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
6999 Sema::InheritedConstructorInfo *ICI)
7000 : S(S), MD(MD), CSM(CSM), ICI(ICI) {
7002 case Sema::CXXDefaultConstructor:
7003 case Sema::CXXCopyConstructor:
7004 case Sema::CXXMoveConstructor:
7005 IsConstructor = true;
7007 case Sema::CXXCopyAssignment:
7008 case Sema::CXXMoveAssignment:
7009 IsAssignment = true;
7011 case Sema::CXXDestructor:
7013 case Sema::CXXInvalid:
7014 llvm_unreachable("invalid special member kind");
7017 if (MD->getNumParams()) {
7018 if (const ReferenceType *RT =
7019 MD->getParamDecl(0)->getType()->getAs<ReferenceType>())
7020 ConstArg = RT->getPointeeType().isConstQualified();
7024 Derived &getDerived() { return static_cast<Derived&>(*this); }
7026 /// Is this a "move" special member?
7027 bool isMove() const {
7028 return CSM == Sema::CXXMoveConstructor || CSM == Sema::CXXMoveAssignment;
7031 /// Look up the corresponding special member in the given class.
7032 Sema::SpecialMemberOverloadResult lookupIn(CXXRecordDecl *Class,
7033 unsigned Quals, bool IsMutable) {
7034 return lookupCallFromSpecialMember(S, Class, CSM, Quals,
7035 ConstArg && !IsMutable);
7038 /// Look up the constructor for the specified base class to see if it's
7039 /// overridden due to this being an inherited constructor.
7040 Sema::SpecialMemberOverloadResult lookupInheritedCtor(CXXRecordDecl *Class) {
7043 assert(CSM == Sema::CXXDefaultConstructor);
7045 cast<CXXConstructorDecl>(MD)->getInheritedConstructor().getConstructor();
7046 if (auto *MD = ICI->findConstructorForBase(Class, BaseCtor).first)
7051 /// A base or member subobject.
7052 typedef llvm::PointerUnion<CXXBaseSpecifier*, FieldDecl*> Subobject;
7054 /// Get the location to use for a subobject in diagnostics.
7055 static SourceLocation getSubobjectLoc(Subobject Subobj) {
7056 // FIXME: For an indirect virtual base, the direct base leading to
7057 // the indirect virtual base would be a more useful choice.
7058 if (auto *B = Subobj.dyn_cast<CXXBaseSpecifier*>())
7059 return B->getBaseTypeLoc();
7061 return Subobj.get<FieldDecl*>()->getLocation();
7065 /// Visit all non-virtual (direct) bases.
7066 VisitNonVirtualBases,
7067 /// Visit all direct bases, virtual or not.
7069 /// Visit all non-virtual bases, and all virtual bases if the class
7070 /// is not abstract.
7071 VisitPotentiallyConstructedBases,
7072 /// Visit all direct or virtual bases.
7076 // Visit the bases and members of the class.
7077 bool visit(BasesToVisit Bases) {
7078 CXXRecordDecl *RD = MD->getParent();
7080 if (Bases == VisitPotentiallyConstructedBases)
7081 Bases = RD->isAbstract() ? VisitNonVirtualBases : VisitAllBases;
7083 for (auto &B : RD->bases())
7084 if ((Bases == VisitDirectBases || !B.isVirtual()) &&
7085 getDerived().visitBase(&B))
7088 if (Bases == VisitAllBases)
7089 for (auto &B : RD->vbases())
7090 if (getDerived().visitBase(&B))
7093 for (auto *F : RD->fields())
7094 if (!F->isInvalidDecl() && !F->isUnnamedBitfield() &&
7095 getDerived().visitField(F))
7104 struct SpecialMemberDeletionInfo
7105 : SpecialMemberVisitor<SpecialMemberDeletionInfo> {
7110 bool AllFieldsAreConst;
7112 SpecialMemberDeletionInfo(Sema &S, CXXMethodDecl *MD,
7113 Sema::CXXSpecialMember CSM,
7114 Sema::InheritedConstructorInfo *ICI, bool Diagnose)
7115 : SpecialMemberVisitor(S, MD, CSM, ICI), Diagnose(Diagnose),
7116 Loc(MD->getLocation()), AllFieldsAreConst(true) {}
7118 bool inUnion() const { return MD->getParent()->isUnion(); }
7120 Sema::CXXSpecialMember getEffectiveCSM() {
7121 return ICI ? Sema::CXXInvalid : CSM;
7124 bool shouldDeleteForVariantObjCPtrMember(FieldDecl *FD, QualType FieldType);
7126 bool visitBase(CXXBaseSpecifier *Base) { return shouldDeleteForBase(Base); }
7127 bool visitField(FieldDecl *Field) { return shouldDeleteForField(Field); }
7129 bool shouldDeleteForBase(CXXBaseSpecifier *Base);
7130 bool shouldDeleteForField(FieldDecl *FD);
7131 bool shouldDeleteForAllConstMembers();
7133 bool shouldDeleteForClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
7135 bool shouldDeleteForSubobjectCall(Subobject Subobj,
7136 Sema::SpecialMemberOverloadResult SMOR,
7137 bool IsDtorCallInCtor);
7139 bool isAccessible(Subobject Subobj, CXXMethodDecl *D);
7143 /// Is the given special member inaccessible when used on the given
7145 bool SpecialMemberDeletionInfo::isAccessible(Subobject Subobj,
7146 CXXMethodDecl *target) {
7147 /// If we're operating on a base class, the object type is the
7148 /// type of this special member.
7150 AccessSpecifier access = target->getAccess();
7151 if (CXXBaseSpecifier *base = Subobj.dyn_cast<CXXBaseSpecifier*>()) {
7152 objectTy = S.Context.getTypeDeclType(MD->getParent());
7153 access = CXXRecordDecl::MergeAccess(base->getAccessSpecifier(), access);
7155 // If we're operating on a field, the object type is the type of the field.
7157 objectTy = S.Context.getTypeDeclType(target->getParent());
7160 return S.isSpecialMemberAccessibleForDeletion(target, access, objectTy);
7163 /// Check whether we should delete a special member due to the implicit
7164 /// definition containing a call to a special member of a subobject.
7165 bool SpecialMemberDeletionInfo::shouldDeleteForSubobjectCall(
7166 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR,
7167 bool IsDtorCallInCtor) {
7168 CXXMethodDecl *Decl = SMOR.getMethod();
7169 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
7173 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::NoMemberOrDeleted)
7174 DiagKind = !Decl ? 0 : 1;
7175 else if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
7177 else if (!isAccessible(Subobj, Decl))
7179 else if (!IsDtorCallInCtor && Field && Field->getParent()->isUnion() &&
7180 !Decl->isTrivial()) {
7181 // A member of a union must have a trivial corresponding special member.
7182 // As a weird special case, a destructor call from a union's constructor
7183 // must be accessible and non-deleted, but need not be trivial. Such a
7184 // destructor is never actually called, but is semantically checked as
7194 S.Diag(Field->getLocation(),
7195 diag::note_deleted_special_member_class_subobject)
7196 << getEffectiveCSM() << MD->getParent() << /*IsField*/true
7197 << Field << DiagKind << IsDtorCallInCtor << /*IsObjCPtr*/false;
7199 CXXBaseSpecifier *Base = Subobj.get<CXXBaseSpecifier*>();
7200 S.Diag(Base->getBeginLoc(),
7201 diag::note_deleted_special_member_class_subobject)
7202 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
7203 << Base->getType() << DiagKind << IsDtorCallInCtor
7204 << /*IsObjCPtr*/false;
7208 S.NoteDeletedFunction(Decl);
7209 // FIXME: Explain inaccessibility if DiagKind == 3.
7215 /// Check whether we should delete a special member function due to having a
7216 /// direct or virtual base class or non-static data member of class type M.
7217 bool SpecialMemberDeletionInfo::shouldDeleteForClassSubobject(
7218 CXXRecordDecl *Class, Subobject Subobj, unsigned Quals) {
7219 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
7220 bool IsMutable = Field && Field->isMutable();
7222 // C++11 [class.ctor]p5:
7223 // -- any direct or virtual base class, or non-static data member with no
7224 // brace-or-equal-initializer, has class type M (or array thereof) and
7225 // either M has no default constructor or overload resolution as applied
7226 // to M's default constructor results in an ambiguity or in a function
7227 // that is deleted or inaccessible
7228 // C++11 [class.copy]p11, C++11 [class.copy]p23:
7229 // -- a direct or virtual base class B that cannot be copied/moved because
7230 // overload resolution, as applied to B's corresponding special member,
7231 // results in an ambiguity or a function that is deleted or inaccessible
7232 // from the defaulted special member
7233 // C++11 [class.dtor]p5:
7234 // -- any direct or virtual base class [...] has a type with a destructor
7235 // that is deleted or inaccessible
7236 if (!(CSM == Sema::CXXDefaultConstructor &&
7237 Field && Field->hasInClassInitializer()) &&
7238 shouldDeleteForSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable),
7242 // C++11 [class.ctor]p5, C++11 [class.copy]p11:
7243 // -- any direct or virtual base class or non-static data member has a
7244 // type with a destructor that is deleted or inaccessible
7245 if (IsConstructor) {
7246 Sema::SpecialMemberOverloadResult SMOR =
7247 S.LookupSpecialMember(Class, Sema::CXXDestructor,
7248 false, false, false, false, false);
7249 if (shouldDeleteForSubobjectCall(Subobj, SMOR, true))
7256 bool SpecialMemberDeletionInfo::shouldDeleteForVariantObjCPtrMember(
7257 FieldDecl *FD, QualType FieldType) {
7258 // The defaulted special functions are defined as deleted if this is a variant
7259 // member with a non-trivial ownership type, e.g., ObjC __strong or __weak
7261 if (!FieldType.hasNonTrivialObjCLifetime())
7264 // Don't make the defaulted default constructor defined as deleted if the
7265 // member has an in-class initializer.
7266 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer())
7270 auto *ParentClass = cast<CXXRecordDecl>(FD->getParent());
7271 S.Diag(FD->getLocation(),
7272 diag::note_deleted_special_member_class_subobject)
7273 << getEffectiveCSM() << ParentClass << /*IsField*/true
7274 << FD << 4 << /*IsDtorCallInCtor*/false << /*IsObjCPtr*/true;
7280 /// Check whether we should delete a special member function due to the class
7281 /// having a particular direct or virtual base class.
7282 bool SpecialMemberDeletionInfo::shouldDeleteForBase(CXXBaseSpecifier *Base) {
7283 CXXRecordDecl *BaseClass = Base->getType()->getAsCXXRecordDecl();
7284 // If program is correct, BaseClass cannot be null, but if it is, the error
7285 // must be reported elsewhere.
7288 // If we have an inheriting constructor, check whether we're calling an
7289 // inherited constructor instead of a default constructor.
7290 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
7291 if (auto *BaseCtor = SMOR.getMethod()) {
7292 // Note that we do not check access along this path; other than that,
7293 // this is the same as shouldDeleteForSubobjectCall(Base, BaseCtor, false);
7294 // FIXME: Check that the base has a usable destructor! Sink this into
7295 // shouldDeleteForClassSubobject.
7296 if (BaseCtor->isDeleted() && Diagnose) {
7297 S.Diag(Base->getBeginLoc(),
7298 diag::note_deleted_special_member_class_subobject)
7299 << getEffectiveCSM() << MD->getParent() << /*IsField*/ false
7300 << Base->getType() << /*Deleted*/ 1 << /*IsDtorCallInCtor*/ false
7301 << /*IsObjCPtr*/false;
7302 S.NoteDeletedFunction(BaseCtor);
7304 return BaseCtor->isDeleted();
7306 return shouldDeleteForClassSubobject(BaseClass, Base, 0);
7309 /// Check whether we should delete a special member function due to the class
7310 /// having a particular non-static data member.
7311 bool SpecialMemberDeletionInfo::shouldDeleteForField(FieldDecl *FD) {
7312 QualType FieldType = S.Context.getBaseElementType(FD->getType());
7313 CXXRecordDecl *FieldRecord = FieldType->getAsCXXRecordDecl();
7315 if (inUnion() && shouldDeleteForVariantObjCPtrMember(FD, FieldType))
7318 if (CSM == Sema::CXXDefaultConstructor) {
7319 // For a default constructor, all references must be initialized in-class
7320 // and, if a union, it must have a non-const member.
7321 if (FieldType->isReferenceType() && !FD->hasInClassInitializer()) {
7323 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
7324 << !!ICI << MD->getParent() << FD << FieldType << /*Reference*/0;
7327 // C++11 [class.ctor]p5: any non-variant non-static data member of
7328 // const-qualified type (or array thereof) with no
7329 // brace-or-equal-initializer does not have a user-provided default
7331 if (!inUnion() && FieldType.isConstQualified() &&
7332 !FD->hasInClassInitializer() &&
7333 (!FieldRecord || !FieldRecord->hasUserProvidedDefaultConstructor())) {
7335 S.Diag(FD->getLocation(), diag::note_deleted_default_ctor_uninit_field)
7336 << !!ICI << MD->getParent() << FD << FD->getType() << /*Const*/1;
7340 if (inUnion() && !FieldType.isConstQualified())
7341 AllFieldsAreConst = false;
7342 } else if (CSM == Sema::CXXCopyConstructor) {
7343 // For a copy constructor, data members must not be of rvalue reference
7345 if (FieldType->isRValueReferenceType()) {
7347 S.Diag(FD->getLocation(), diag::note_deleted_copy_ctor_rvalue_reference)
7348 << MD->getParent() << FD << FieldType;
7351 } else if (IsAssignment) {
7352 // For an assignment operator, data members must not be of reference type.
7353 if (FieldType->isReferenceType()) {
7355 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
7356 << isMove() << MD->getParent() << FD << FieldType << /*Reference*/0;
7359 if (!FieldRecord && FieldType.isConstQualified()) {
7360 // C++11 [class.copy]p23:
7361 // -- a non-static data member of const non-class type (or array thereof)
7363 S.Diag(FD->getLocation(), diag::note_deleted_assign_field)
7364 << isMove() << MD->getParent() << FD << FD->getType() << /*Const*/1;
7370 // Some additional restrictions exist on the variant members.
7371 if (!inUnion() && FieldRecord->isUnion() &&
7372 FieldRecord->isAnonymousStructOrUnion()) {
7373 bool AllVariantFieldsAreConst = true;
7375 // FIXME: Handle anonymous unions declared within anonymous unions.
7376 for (auto *UI : FieldRecord->fields()) {
7377 QualType UnionFieldType = S.Context.getBaseElementType(UI->getType());
7379 if (shouldDeleteForVariantObjCPtrMember(&*UI, UnionFieldType))
7382 if (!UnionFieldType.isConstQualified())
7383 AllVariantFieldsAreConst = false;
7385 CXXRecordDecl *UnionFieldRecord = UnionFieldType->getAsCXXRecordDecl();
7386 if (UnionFieldRecord &&
7387 shouldDeleteForClassSubobject(UnionFieldRecord, UI,
7388 UnionFieldType.getCVRQualifiers()))
7392 // At least one member in each anonymous union must be non-const
7393 if (CSM == Sema::CXXDefaultConstructor && AllVariantFieldsAreConst &&
7394 !FieldRecord->field_empty()) {
7396 S.Diag(FieldRecord->getLocation(),
7397 diag::note_deleted_default_ctor_all_const)
7398 << !!ICI << MD->getParent() << /*anonymous union*/1;
7402 // Don't check the implicit member of the anonymous union type.
7403 // This is technically non-conformant, but sanity demands it.
7407 if (shouldDeleteForClassSubobject(FieldRecord, FD,
7408 FieldType.getCVRQualifiers()))
7415 /// C++11 [class.ctor] p5:
7416 /// A defaulted default constructor for a class X is defined as deleted if
7417 /// X is a union and all of its variant members are of const-qualified type.
7418 bool SpecialMemberDeletionInfo::shouldDeleteForAllConstMembers() {
7419 // This is a silly definition, because it gives an empty union a deleted
7420 // default constructor. Don't do that.
7421 if (CSM == Sema::CXXDefaultConstructor && inUnion() && AllFieldsAreConst) {
7422 bool AnyFields = false;
7423 for (auto *F : MD->getParent()->fields())
7424 if ((AnyFields = !F->isUnnamedBitfield()))
7429 S.Diag(MD->getParent()->getLocation(),
7430 diag::note_deleted_default_ctor_all_const)
7431 << !!ICI << MD->getParent() << /*not anonymous union*/0;
7437 /// Determine whether a defaulted special member function should be defined as
7438 /// deleted, as specified in C++11 [class.ctor]p5, C++11 [class.copy]p11,
7439 /// C++11 [class.copy]p23, and C++11 [class.dtor]p5.
7440 bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
7441 InheritedConstructorInfo *ICI,
7443 if (MD->isInvalidDecl())
7445 CXXRecordDecl *RD = MD->getParent();
7446 assert(!RD->isDependentType() && "do deletion after instantiation");
7447 if (!LangOpts.CPlusPlus11 || RD->isInvalidDecl())
7450 // C++11 [expr.lambda.prim]p19:
7451 // The closure type associated with a lambda-expression has a
7452 // deleted (8.4.3) default constructor and a deleted copy
7453 // assignment operator.
7454 // C++2a adds back these operators if the lambda has no lambda-capture.
7455 if (RD->isLambda() && !RD->lambdaIsDefaultConstructibleAndAssignable() &&
7456 (CSM == CXXDefaultConstructor || CSM == CXXCopyAssignment)) {
7458 Diag(RD->getLocation(), diag::note_lambda_decl);
7462 // For an anonymous struct or union, the copy and assignment special members
7463 // will never be used, so skip the check. For an anonymous union declared at
7464 // namespace scope, the constructor and destructor are used.
7465 if (CSM != CXXDefaultConstructor && CSM != CXXDestructor &&
7466 RD->isAnonymousStructOrUnion())
7469 // C++11 [class.copy]p7, p18:
7470 // If the class definition declares a move constructor or move assignment
7471 // operator, an implicitly declared copy constructor or copy assignment
7472 // operator is defined as deleted.
7473 if (MD->isImplicit() &&
7474 (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
7475 CXXMethodDecl *UserDeclaredMove = nullptr;
7477 // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
7478 // deletion of the corresponding copy operation, not both copy operations.
7479 // MSVC 2015 has adopted the standards conforming behavior.
7480 bool DeletesOnlyMatchingCopy =
7481 getLangOpts().MSVCCompat &&
7482 !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
7484 if (RD->hasUserDeclaredMoveConstructor() &&
7485 (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
7486 if (!Diagnose) return true;
7488 // Find any user-declared move constructor.
7489 for (auto *I : RD->ctors()) {
7490 if (I->isMoveConstructor()) {
7491 UserDeclaredMove = I;
7495 assert(UserDeclaredMove);
7496 } else if (RD->hasUserDeclaredMoveAssignment() &&
7497 (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
7498 if (!Diagnose) return true;
7500 // Find any user-declared move assignment operator.
7501 for (auto *I : RD->methods()) {
7502 if (I->isMoveAssignmentOperator()) {
7503 UserDeclaredMove = I;
7507 assert(UserDeclaredMove);
7510 if (UserDeclaredMove) {
7511 Diag(UserDeclaredMove->getLocation(),
7512 diag::note_deleted_copy_user_declared_move)
7513 << (CSM == CXXCopyAssignment) << RD
7514 << UserDeclaredMove->isMoveAssignmentOperator();
7519 // Do access control from the special member function
7520 ContextRAII MethodContext(*this, MD);
7522 // C++11 [class.dtor]p5:
7523 // -- for a virtual destructor, lookup of the non-array deallocation function
7524 // results in an ambiguity or in a function that is deleted or inaccessible
7525 if (CSM == CXXDestructor && MD->isVirtual()) {
7526 FunctionDecl *OperatorDelete = nullptr;
7527 DeclarationName Name =
7528 Context.DeclarationNames.getCXXOperatorName(OO_Delete);
7529 if (FindDeallocationFunction(MD->getLocation(), MD->getParent(), Name,
7530 OperatorDelete, /*Diagnose*/false)) {
7532 Diag(RD->getLocation(), diag::note_deleted_dtor_no_operator_delete);
7537 SpecialMemberDeletionInfo SMI(*this, MD, CSM, ICI, Diagnose);
7539 // Per DR1611, do not consider virtual bases of constructors of abstract
7540 // classes, since we are not going to construct them.
7541 // Per DR1658, do not consider virtual bases of destructors of abstract
7543 // Per DR2180, for assignment operators we only assign (and thus only
7544 // consider) direct bases.
7545 if (SMI.visit(SMI.IsAssignment ? SMI.VisitDirectBases
7546 : SMI.VisitPotentiallyConstructedBases))
7549 if (SMI.shouldDeleteForAllConstMembers())
7552 if (getLangOpts().CUDA) {
7553 // We should delete the special member in CUDA mode if target inference
7555 // For inherited constructors (non-null ICI), CSM may be passed so that MD
7556 // is treated as certain special member, which may not reflect what special
7557 // member MD really is. However inferCUDATargetForImplicitSpecialMember
7558 // expects CSM to match MD, therefore recalculate CSM.
7559 assert(ICI || CSM == getSpecialMember(MD));
7562 RealCSM = getSpecialMember(MD);
7564 return inferCUDATargetForImplicitSpecialMember(RD, RealCSM, MD,
7565 SMI.ConstArg, Diagnose);
7571 /// Perform lookup for a special member of the specified kind, and determine
7572 /// whether it is trivial. If the triviality can be determined without the
7573 /// lookup, skip it. This is intended for use when determining whether a
7574 /// special member of a containing object is trivial, and thus does not ever
7575 /// perform overload resolution for default constructors.
7577 /// If \p Selected is not \c NULL, \c *Selected will be filled in with the
7578 /// member that was most likely to be intended to be trivial, if any.
7580 /// If \p ForCall is true, look at CXXRecord::HasTrivialSpecialMembersForCall to
7581 /// determine whether the special member is trivial.
7582 static bool findTrivialSpecialMember(Sema &S, CXXRecordDecl *RD,
7583 Sema::CXXSpecialMember CSM, unsigned Quals,
7585 Sema::TrivialABIHandling TAH,
7586 CXXMethodDecl **Selected) {
7588 *Selected = nullptr;
7591 case Sema::CXXInvalid:
7592 llvm_unreachable("not a special member");
7594 case Sema::CXXDefaultConstructor:
7595 // C++11 [class.ctor]p5:
7596 // A default constructor is trivial if:
7597 // - all the [direct subobjects] have trivial default constructors
7599 // Note, no overload resolution is performed in this case.
7600 if (RD->hasTrivialDefaultConstructor())
7604 // If there's a default constructor which could have been trivial, dig it
7605 // out. Otherwise, if there's any user-provided default constructor, point
7606 // to that as an example of why there's not a trivial one.
7607 CXXConstructorDecl *DefCtor = nullptr;
7608 if (RD->needsImplicitDefaultConstructor())
7609 S.DeclareImplicitDefaultConstructor(RD);
7610 for (auto *CI : RD->ctors()) {
7611 if (!CI->isDefaultConstructor())
7614 if (!DefCtor->isUserProvided())
7618 *Selected = DefCtor;
7623 case Sema::CXXDestructor:
7624 // C++11 [class.dtor]p5:
7625 // A destructor is trivial if:
7626 // - all the direct [subobjects] have trivial destructors
7627 if (RD->hasTrivialDestructor() ||
7628 (TAH == Sema::TAH_ConsiderTrivialABI &&
7629 RD->hasTrivialDestructorForCall()))
7633 if (RD->needsImplicitDestructor())
7634 S.DeclareImplicitDestructor(RD);
7635 *Selected = RD->getDestructor();
7640 case Sema::CXXCopyConstructor:
7641 // C++11 [class.copy]p12:
7642 // A copy constructor is trivial if:
7643 // - the constructor selected to copy each direct [subobject] is trivial
7644 if (RD->hasTrivialCopyConstructor() ||
7645 (TAH == Sema::TAH_ConsiderTrivialABI &&
7646 RD->hasTrivialCopyConstructorForCall())) {
7647 if (Quals == Qualifiers::Const)
7648 // We must either select the trivial copy constructor or reach an
7649 // ambiguity; no need to actually perform overload resolution.
7651 } else if (!Selected) {
7654 // In C++98, we are not supposed to perform overload resolution here, but we
7655 // treat that as a language defect, as suggested on cxx-abi-dev, to treat
7656 // cases like B as having a non-trivial copy constructor:
7657 // struct A { template<typename T> A(T&); };
7658 // struct B { mutable A a; };
7659 goto NeedOverloadResolution;
7661 case Sema::CXXCopyAssignment:
7662 // C++11 [class.copy]p25:
7663 // A copy assignment operator is trivial if:
7664 // - the assignment operator selected to copy each direct [subobject] is
7666 if (RD->hasTrivialCopyAssignment()) {
7667 if (Quals == Qualifiers::Const)
7669 } else if (!Selected) {
7672 // In C++98, we are not supposed to perform overload resolution here, but we
7673 // treat that as a language defect.
7674 goto NeedOverloadResolution;
7676 case Sema::CXXMoveConstructor:
7677 case Sema::CXXMoveAssignment:
7678 NeedOverloadResolution:
7679 Sema::SpecialMemberOverloadResult SMOR =
7680 lookupCallFromSpecialMember(S, RD, CSM, Quals, ConstRHS);
7682 // The standard doesn't describe how to behave if the lookup is ambiguous.
7683 // We treat it as not making the member non-trivial, just like the standard
7684 // mandates for the default constructor. This should rarely matter, because
7685 // the member will also be deleted.
7686 if (SMOR.getKind() == Sema::SpecialMemberOverloadResult::Ambiguous)
7689 if (!SMOR.getMethod()) {
7690 assert(SMOR.getKind() ==
7691 Sema::SpecialMemberOverloadResult::NoMemberOrDeleted);
7695 // We deliberately don't check if we found a deleted special member. We're
7698 *Selected = SMOR.getMethod();
7700 if (TAH == Sema::TAH_ConsiderTrivialABI &&
7701 (CSM == Sema::CXXCopyConstructor || CSM == Sema::CXXMoveConstructor))
7702 return SMOR.getMethod()->isTrivialForCall();
7703 return SMOR.getMethod()->isTrivial();
7706 llvm_unreachable("unknown special method kind");
7709 static CXXConstructorDecl *findUserDeclaredCtor(CXXRecordDecl *RD) {
7710 for (auto *CI : RD->ctors())
7711 if (!CI->isImplicit())
7714 // Look for constructor templates.
7715 typedef CXXRecordDecl::specific_decl_iterator<FunctionTemplateDecl> tmpl_iter;
7716 for (tmpl_iter TI(RD->decls_begin()), TE(RD->decls_end()); TI != TE; ++TI) {
7717 if (CXXConstructorDecl *CD =
7718 dyn_cast<CXXConstructorDecl>(TI->getTemplatedDecl()))
7725 /// The kind of subobject we are checking for triviality. The values of this
7726 /// enumeration are used in diagnostics.
7727 enum TrivialSubobjectKind {
7728 /// The subobject is a base class.
7730 /// The subobject is a non-static data member.
7732 /// The object is actually the complete object.
7736 /// Check whether the special member selected for a given type would be trivial.
7737 static bool checkTrivialSubobjectCall(Sema &S, SourceLocation SubobjLoc,
7738 QualType SubType, bool ConstRHS,
7739 Sema::CXXSpecialMember CSM,
7740 TrivialSubobjectKind Kind,
7741 Sema::TrivialABIHandling TAH, bool Diagnose) {
7742 CXXRecordDecl *SubRD = SubType->getAsCXXRecordDecl();
7746 CXXMethodDecl *Selected;
7747 if (findTrivialSpecialMember(S, SubRD, CSM, SubType.getCVRQualifiers(),
7748 ConstRHS, TAH, Diagnose ? &Selected : nullptr))
7755 if (!Selected && CSM == Sema::CXXDefaultConstructor) {
7756 S.Diag(SubobjLoc, diag::note_nontrivial_no_def_ctor)
7757 << Kind << SubType.getUnqualifiedType();
7758 if (CXXConstructorDecl *CD = findUserDeclaredCtor(SubRD))
7759 S.Diag(CD->getLocation(), diag::note_user_declared_ctor);
7760 } else if (!Selected)
7761 S.Diag(SubobjLoc, diag::note_nontrivial_no_copy)
7762 << Kind << SubType.getUnqualifiedType() << CSM << SubType;
7763 else if (Selected->isUserProvided()) {
7764 if (Kind == TSK_CompleteObject)
7765 S.Diag(Selected->getLocation(), diag::note_nontrivial_user_provided)
7766 << Kind << SubType.getUnqualifiedType() << CSM;
7768 S.Diag(SubobjLoc, diag::note_nontrivial_user_provided)
7769 << Kind << SubType.getUnqualifiedType() << CSM;
7770 S.Diag(Selected->getLocation(), diag::note_declared_at);
7773 if (Kind != TSK_CompleteObject)
7774 S.Diag(SubobjLoc, diag::note_nontrivial_subobject)
7775 << Kind << SubType.getUnqualifiedType() << CSM;
7777 // Explain why the defaulted or deleted special member isn't trivial.
7778 S.SpecialMemberIsTrivial(Selected, CSM, Sema::TAH_IgnoreTrivialABI,
7786 /// Check whether the members of a class type allow a special member to be
7788 static bool checkTrivialClassMembers(Sema &S, CXXRecordDecl *RD,
7789 Sema::CXXSpecialMember CSM,
7791 Sema::TrivialABIHandling TAH,
7793 for (const auto *FI : RD->fields()) {
7794 if (FI->isInvalidDecl() || FI->isUnnamedBitfield())
7797 QualType FieldType = S.Context.getBaseElementType(FI->getType());
7799 // Pretend anonymous struct or union members are members of this class.
7800 if (FI->isAnonymousStructOrUnion()) {
7801 if (!checkTrivialClassMembers(S, FieldType->getAsCXXRecordDecl(),
7802 CSM, ConstArg, TAH, Diagnose))
7807 // C++11 [class.ctor]p5:
7808 // A default constructor is trivial if [...]
7809 // -- no non-static data member of its class has a
7810 // brace-or-equal-initializer
7811 if (CSM == Sema::CXXDefaultConstructor && FI->hasInClassInitializer()) {
7813 S.Diag(FI->getLocation(), diag::note_nontrivial_in_class_init) << FI;
7817 // Objective C ARC 4.3.5:
7818 // [...] nontrivally ownership-qualified types are [...] not trivially
7819 // default constructible, copy constructible, move constructible, copy
7820 // assignable, move assignable, or destructible [...]
7821 if (FieldType.hasNonTrivialObjCLifetime()) {
7823 S.Diag(FI->getLocation(), diag::note_nontrivial_objc_ownership)
7824 << RD << FieldType.getObjCLifetime();
7828 bool ConstRHS = ConstArg && !FI->isMutable();
7829 if (!checkTrivialSubobjectCall(S, FI->getLocation(), FieldType, ConstRHS,
7830 CSM, TSK_Field, TAH, Diagnose))
7837 /// Diagnose why the specified class does not have a trivial special member of
7839 void Sema::DiagnoseNontrivial(const CXXRecordDecl *RD, CXXSpecialMember CSM) {
7840 QualType Ty = Context.getRecordType(RD);
7842 bool ConstArg = (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment);
7843 checkTrivialSubobjectCall(*this, RD->getLocation(), Ty, ConstArg, CSM,
7844 TSK_CompleteObject, TAH_IgnoreTrivialABI,
7848 /// Determine whether a defaulted or deleted special member function is trivial,
7849 /// as specified in C++11 [class.ctor]p5, C++11 [class.copy]p12,
7850 /// C++11 [class.copy]p25, and C++11 [class.dtor]p5.
7851 bool Sema::SpecialMemberIsTrivial(CXXMethodDecl *MD, CXXSpecialMember CSM,
7852 TrivialABIHandling TAH, bool Diagnose) {
7853 assert(!MD->isUserProvided() && CSM != CXXInvalid && "not special enough");
7855 CXXRecordDecl *RD = MD->getParent();
7857 bool ConstArg = false;
7859 // C++11 [class.copy]p12, p25: [DR1593]
7860 // A [special member] is trivial if [...] its parameter-type-list is
7861 // equivalent to the parameter-type-list of an implicit declaration [...]
7863 case CXXDefaultConstructor:
7865 // Trivial default constructors and destructors cannot have parameters.
7868 case CXXCopyConstructor:
7869 case CXXCopyAssignment: {
7870 // Trivial copy operations always have const, non-volatile parameter types.
7872 const ParmVarDecl *Param0 = MD->getParamDecl(0);
7873 const ReferenceType *RT = Param0->getType()->getAs<ReferenceType>();
7874 if (!RT || RT->getPointeeType().getCVRQualifiers() != Qualifiers::Const) {
7876 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
7877 << Param0->getSourceRange() << Param0->getType()
7878 << Context.getLValueReferenceType(
7879 Context.getRecordType(RD).withConst());
7885 case CXXMoveConstructor:
7886 case CXXMoveAssignment: {
7887 // Trivial move operations always have non-cv-qualified parameters.
7888 const ParmVarDecl *Param0 = MD->getParamDecl(0);
7889 const RValueReferenceType *RT =
7890 Param0->getType()->getAs<RValueReferenceType>();
7891 if (!RT || RT->getPointeeType().getCVRQualifiers()) {
7893 Diag(Param0->getLocation(), diag::note_nontrivial_param_type)
7894 << Param0->getSourceRange() << Param0->getType()
7895 << Context.getRValueReferenceType(Context.getRecordType(RD));
7902 llvm_unreachable("not a special member");
7905 if (MD->getMinRequiredArguments() < MD->getNumParams()) {
7907 Diag(MD->getParamDecl(MD->getMinRequiredArguments())->getLocation(),
7908 diag::note_nontrivial_default_arg)
7909 << MD->getParamDecl(MD->getMinRequiredArguments())->getSourceRange();
7912 if (MD->isVariadic()) {
7914 Diag(MD->getLocation(), diag::note_nontrivial_variadic);
7918 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
7919 // A copy/move [constructor or assignment operator] is trivial if
7920 // -- the [member] selected to copy/move each direct base class subobject
7923 // C++11 [class.copy]p12, C++11 [class.copy]p25:
7924 // A [default constructor or destructor] is trivial if
7925 // -- all the direct base classes have trivial [default constructors or
7927 for (const auto &BI : RD->bases())
7928 if (!checkTrivialSubobjectCall(*this, BI.getBeginLoc(), BI.getType(),
7929 ConstArg, CSM, TSK_BaseClass, TAH, Diagnose))
7932 // C++11 [class.ctor]p5, C++11 [class.dtor]p5:
7933 // A copy/move [constructor or assignment operator] for a class X is
7935 // -- for each non-static data member of X that is of class type (or array
7936 // thereof), the constructor selected to copy/move that member is
7939 // C++11 [class.copy]p12, C++11 [class.copy]p25:
7940 // A [default constructor or destructor] is trivial if
7941 // -- for all of the non-static data members of its class that are of class
7942 // type (or array thereof), each such class has a trivial [default
7943 // constructor or destructor]
7944 if (!checkTrivialClassMembers(*this, RD, CSM, ConstArg, TAH, Diagnose))
7947 // C++11 [class.dtor]p5:
7948 // A destructor is trivial if [...]
7949 // -- the destructor is not virtual
7950 if (CSM == CXXDestructor && MD->isVirtual()) {
7952 Diag(MD->getLocation(), diag::note_nontrivial_virtual_dtor) << RD;
7956 // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
7957 // A [special member] for class X is trivial if [...]
7958 // -- class X has no virtual functions and no virtual base classes
7959 if (CSM != CXXDestructor && MD->getParent()->isDynamicClass()) {
7963 if (RD->getNumVBases()) {
7964 // Check for virtual bases. We already know that the corresponding
7965 // member in all bases is trivial, so vbases must all be direct.
7966 CXXBaseSpecifier &BS = *RD->vbases_begin();
7967 assert(BS.isVirtual());
7968 Diag(BS.getBeginLoc(), diag::note_nontrivial_has_virtual) << RD << 1;
7972 // Must have a virtual method.
7973 for (const auto *MI : RD->methods()) {
7974 if (MI->isVirtual()) {
7975 SourceLocation MLoc = MI->getBeginLoc();
7976 Diag(MLoc, diag::note_nontrivial_has_virtual) << RD << 0;
7981 llvm_unreachable("dynamic class with no vbases and no virtual functions");
7984 // Looks like it's trivial!
7989 struct FindHiddenVirtualMethod {
7991 CXXMethodDecl *Method;
7992 llvm::SmallPtrSet<const CXXMethodDecl *, 8> OverridenAndUsingBaseMethods;
7993 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
7996 /// Check whether any most overridden method from MD in Methods
7997 static bool CheckMostOverridenMethods(
7998 const CXXMethodDecl *MD,
7999 const llvm::SmallPtrSetImpl<const CXXMethodDecl *> &Methods) {
8000 if (MD->size_overridden_methods() == 0)
8001 return Methods.count(MD->getCanonicalDecl());
8002 for (const CXXMethodDecl *O : MD->overridden_methods())
8003 if (CheckMostOverridenMethods(O, Methods))
8009 /// Member lookup function that determines whether a given C++
8010 /// method overloads virtual methods in a base class without overriding any,
8011 /// to be used with CXXRecordDecl::lookupInBases().
8012 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
8013 RecordDecl *BaseRecord =
8014 Specifier->getType()->castAs<RecordType>()->getDecl();
8016 DeclarationName Name = Method->getDeclName();
8017 assert(Name.getNameKind() == DeclarationName::Identifier);
8019 bool foundSameNameMethod = false;
8020 SmallVector<CXXMethodDecl *, 8> overloadedMethods;
8021 for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty();
8022 Path.Decls = Path.Decls.slice(1)) {
8023 NamedDecl *D = Path.Decls.front();
8024 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
8025 MD = MD->getCanonicalDecl();
8026 foundSameNameMethod = true;
8027 // Interested only in hidden virtual methods.
8028 if (!MD->isVirtual())
8030 // If the method we are checking overrides a method from its base
8031 // don't warn about the other overloaded methods. Clang deviates from
8032 // GCC by only diagnosing overloads of inherited virtual functions that
8033 // do not override any other virtual functions in the base. GCC's
8034 // -Woverloaded-virtual diagnoses any derived function hiding a virtual
8035 // function from a base class. These cases may be better served by a
8036 // warning (not specific to virtual functions) on call sites when the
8037 // call would select a different function from the base class, were it
8039 // See FIXME in test/SemaCXX/warn-overload-virtual.cpp for an example.
8040 if (!S->IsOverload(Method, MD, false))
8042 // Collect the overload only if its hidden.
8043 if (!CheckMostOverridenMethods(MD, OverridenAndUsingBaseMethods))
8044 overloadedMethods.push_back(MD);
8048 if (foundSameNameMethod)
8049 OverloadedMethods.append(overloadedMethods.begin(),
8050 overloadedMethods.end());
8051 return foundSameNameMethod;
8054 } // end anonymous namespace
8056 /// Add the most overriden methods from MD to Methods
8057 static void AddMostOverridenMethods(const CXXMethodDecl *MD,
8058 llvm::SmallPtrSetImpl<const CXXMethodDecl *>& Methods) {
8059 if (MD->size_overridden_methods() == 0)
8060 Methods.insert(MD->getCanonicalDecl());
8062 for (const CXXMethodDecl *O : MD->overridden_methods())
8063 AddMostOverridenMethods(O, Methods);
8066 /// Check if a method overloads virtual methods in a base class without
8068 void Sema::FindHiddenVirtualMethods(CXXMethodDecl *MD,
8069 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
8070 if (!MD->getDeclName().isIdentifier())
8073 CXXBasePaths Paths(/*FindAmbiguities=*/true, // true to look in all bases.
8074 /*bool RecordPaths=*/false,
8075 /*bool DetectVirtual=*/false);
8076 FindHiddenVirtualMethod FHVM;
8080 // Keep the base methods that were overridden or introduced in the subclass
8081 // by 'using' in a set. A base method not in this set is hidden.
8082 CXXRecordDecl *DC = MD->getParent();
8083 DeclContext::lookup_result R = DC->lookup(MD->getDeclName());
8084 for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
8086 if (UsingShadowDecl *shad = dyn_cast<UsingShadowDecl>(*I))
8087 ND = shad->getTargetDecl();
8088 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(ND))
8089 AddMostOverridenMethods(MD, FHVM.OverridenAndUsingBaseMethods);
8092 if (DC->lookupInBases(FHVM, Paths))
8093 OverloadedMethods = FHVM.OverloadedMethods;
8096 void Sema::NoteHiddenVirtualMethods(CXXMethodDecl *MD,
8097 SmallVectorImpl<CXXMethodDecl*> &OverloadedMethods) {
8098 for (unsigned i = 0, e = OverloadedMethods.size(); i != e; ++i) {
8099 CXXMethodDecl *overloadedMD = OverloadedMethods[i];
8100 PartialDiagnostic PD = PDiag(
8101 diag::note_hidden_overloaded_virtual_declared_here) << overloadedMD;
8102 HandleFunctionTypeMismatch(PD, MD->getType(), overloadedMD->getType());
8103 Diag(overloadedMD->getLocation(), PD);
8107 /// Diagnose methods which overload virtual methods in a base class
8108 /// without overriding any.
8109 void Sema::DiagnoseHiddenVirtualMethods(CXXMethodDecl *MD) {
8110 if (MD->isInvalidDecl())
8113 if (Diags.isIgnored(diag::warn_overloaded_virtual, MD->getLocation()))
8116 SmallVector<CXXMethodDecl *, 8> OverloadedMethods;
8117 FindHiddenVirtualMethods(MD, OverloadedMethods);
8118 if (!OverloadedMethods.empty()) {
8119 Diag(MD->getLocation(), diag::warn_overloaded_virtual)
8120 << MD << (OverloadedMethods.size() > 1);
8122 NoteHiddenVirtualMethods(MD, OverloadedMethods);
8126 void Sema::checkIllFormedTrivialABIStruct(CXXRecordDecl &RD) {
8127 auto PrintDiagAndRemoveAttr = [&]() {
8128 // No diagnostics if this is a template instantiation.
8129 if (!isTemplateInstantiation(RD.getTemplateSpecializationKind()))
8130 Diag(RD.getAttr<TrivialABIAttr>()->getLocation(),
8131 diag::ext_cannot_use_trivial_abi) << &RD;
8132 RD.dropAttr<TrivialABIAttr>();
8135 // Ill-formed if the struct has virtual functions.
8136 if (RD.isPolymorphic()) {
8137 PrintDiagAndRemoveAttr();
8141 for (const auto &B : RD.bases()) {
8142 // Ill-formed if the base class is non-trivial for the purpose of calls or a
8144 if ((!B.getType()->isDependentType() &&
8145 !B.getType()->getAsCXXRecordDecl()->canPassInRegisters()) ||
8147 PrintDiagAndRemoveAttr();
8152 for (const auto *FD : RD.fields()) {
8153 // Ill-formed if the field is an ObjectiveC pointer or of a type that is
8154 // non-trivial for the purpose of calls.
8155 QualType FT = FD->getType();
8156 if (FT.getObjCLifetime() == Qualifiers::OCL_Weak) {
8157 PrintDiagAndRemoveAttr();
8161 if (const auto *RT = FT->getBaseElementTypeUnsafe()->getAs<RecordType>())
8162 if (!RT->isDependentType() &&
8163 !cast<CXXRecordDecl>(RT->getDecl())->canPassInRegisters()) {
8164 PrintDiagAndRemoveAttr();
8170 void Sema::ActOnFinishCXXMemberSpecification(
8171 Scope *S, SourceLocation RLoc, Decl *TagDecl, SourceLocation LBrac,
8172 SourceLocation RBrac, const ParsedAttributesView &AttrList) {
8176 AdjustDeclIfTemplate(TagDecl);
8178 for (const ParsedAttr &AL : AttrList) {
8179 if (AL.getKind() != ParsedAttr::AT_Visibility)
8182 Diag(AL.getLoc(), diag::warn_attribute_after_definition_ignored) << AL;
8185 ActOnFields(S, RLoc, TagDecl, llvm::makeArrayRef(
8186 // strict aliasing violation!
8187 reinterpret_cast<Decl**>(FieldCollector->getCurFields()),
8188 FieldCollector->getCurNumFields()), LBrac, RBrac, AttrList);
8190 CheckCompletedCXXClass(cast<CXXRecordDecl>(TagDecl));
8193 /// AddImplicitlyDeclaredMembersToClass - Adds any implicitly-declared
8194 /// special functions, such as the default constructor, copy
8195 /// constructor, or destructor, to the given C++ class (C++
8196 /// [special]p1). This routine can only be executed just before the
8197 /// definition of the class is complete.
8198 void Sema::AddImplicitlyDeclaredMembersToClass(CXXRecordDecl *ClassDecl) {
8199 if (ClassDecl->needsImplicitDefaultConstructor()) {
8200 ++getASTContext().NumImplicitDefaultConstructors;
8202 if (ClassDecl->hasInheritedConstructor())
8203 DeclareImplicitDefaultConstructor(ClassDecl);
8206 if (ClassDecl->needsImplicitCopyConstructor()) {
8207 ++getASTContext().NumImplicitCopyConstructors;
8209 // If the properties or semantics of the copy constructor couldn't be
8210 // determined while the class was being declared, force a declaration
8212 if (ClassDecl->needsOverloadResolutionForCopyConstructor() ||
8213 ClassDecl->hasInheritedConstructor())
8214 DeclareImplicitCopyConstructor(ClassDecl);
8215 // For the MS ABI we need to know whether the copy ctor is deleted. A
8216 // prerequisite for deleting the implicit copy ctor is that the class has a
8217 // move ctor or move assignment that is either user-declared or whose
8218 // semantics are inherited from a subobject. FIXME: We should provide a more
8219 // direct way for CodeGen to ask whether the constructor was deleted.
8220 else if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
8221 (ClassDecl->hasUserDeclaredMoveConstructor() ||
8222 ClassDecl->needsOverloadResolutionForMoveConstructor() ||
8223 ClassDecl->hasUserDeclaredMoveAssignment() ||
8224 ClassDecl->needsOverloadResolutionForMoveAssignment()))
8225 DeclareImplicitCopyConstructor(ClassDecl);
8228 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveConstructor()) {
8229 ++getASTContext().NumImplicitMoveConstructors;
8231 if (ClassDecl->needsOverloadResolutionForMoveConstructor() ||
8232 ClassDecl->hasInheritedConstructor())
8233 DeclareImplicitMoveConstructor(ClassDecl);
8236 if (ClassDecl->needsImplicitCopyAssignment()) {
8237 ++getASTContext().NumImplicitCopyAssignmentOperators;
8239 // If we have a dynamic class, then the copy assignment operator may be
8240 // virtual, so we have to declare it immediately. This ensures that, e.g.,
8241 // it shows up in the right place in the vtable and that we diagnose
8242 // problems with the implicit exception specification.
8243 if (ClassDecl->isDynamicClass() ||
8244 ClassDecl->needsOverloadResolutionForCopyAssignment() ||
8245 ClassDecl->hasInheritedAssignment())
8246 DeclareImplicitCopyAssignment(ClassDecl);
8249 if (getLangOpts().CPlusPlus11 && ClassDecl->needsImplicitMoveAssignment()) {
8250 ++getASTContext().NumImplicitMoveAssignmentOperators;
8252 // Likewise for the move assignment operator.
8253 if (ClassDecl->isDynamicClass() ||
8254 ClassDecl->needsOverloadResolutionForMoveAssignment() ||
8255 ClassDecl->hasInheritedAssignment())
8256 DeclareImplicitMoveAssignment(ClassDecl);
8259 if (ClassDecl->needsImplicitDestructor()) {
8260 ++getASTContext().NumImplicitDestructors;
8262 // If we have a dynamic class, then the destructor may be virtual, so we
8263 // have to declare the destructor immediately. This ensures that, e.g., it
8264 // shows up in the right place in the vtable and that we diagnose problems
8265 // with the implicit exception specification.
8266 if (ClassDecl->isDynamicClass() ||
8267 ClassDecl->needsOverloadResolutionForDestructor())
8268 DeclareImplicitDestructor(ClassDecl);
8272 unsigned Sema::ActOnReenterTemplateScope(Scope *S, Decl *D) {
8276 // The order of template parameters is not important here. All names
8277 // get added to the same scope.
8278 SmallVector<TemplateParameterList *, 4> ParameterLists;
8280 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
8281 D = TD->getTemplatedDecl();
8283 if (auto *PSD = dyn_cast<ClassTemplatePartialSpecializationDecl>(D))
8284 ParameterLists.push_back(PSD->getTemplateParameters());
8286 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
8287 for (unsigned i = 0; i < DD->getNumTemplateParameterLists(); ++i)
8288 ParameterLists.push_back(DD->getTemplateParameterList(i));
8290 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
8291 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate())
8292 ParameterLists.push_back(FTD->getTemplateParameters());
8296 if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
8297 for (unsigned i = 0; i < TD->getNumTemplateParameterLists(); ++i)
8298 ParameterLists.push_back(TD->getTemplateParameterList(i));
8300 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(TD)) {
8301 if (ClassTemplateDecl *CTD = RD->getDescribedClassTemplate())
8302 ParameterLists.push_back(CTD->getTemplateParameters());
8307 for (TemplateParameterList *Params : ParameterLists) {
8308 if (Params->size() > 0)
8309 // Ignore explicit specializations; they don't contribute to the template
8312 for (NamedDecl *Param : *Params) {
8313 if (Param->getDeclName()) {
8315 IdResolver.AddDecl(Param);
8323 void Sema::ActOnStartDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
8324 if (!RecordD) return;
8325 AdjustDeclIfTemplate(RecordD);
8326 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordD);
8327 PushDeclContext(S, Record);
8330 void Sema::ActOnFinishDelayedMemberDeclarations(Scope *S, Decl *RecordD) {
8331 if (!RecordD) return;
8335 /// This is used to implement the constant expression evaluation part of the
8336 /// attribute enable_if extension. There is nothing in standard C++ which would
8337 /// require reentering parameters.
8338 void Sema::ActOnReenterCXXMethodParameter(Scope *S, ParmVarDecl *Param) {
8343 if (Param->getDeclName())
8344 IdResolver.AddDecl(Param);
8347 /// ActOnStartDelayedCXXMethodDeclaration - We have completed
8348 /// parsing a top-level (non-nested) C++ class, and we are now
8349 /// parsing those parts of the given Method declaration that could
8350 /// not be parsed earlier (C++ [class.mem]p2), such as default
8351 /// arguments. This action should enter the scope of the given
8352 /// Method declaration as if we had just parsed the qualified method
8353 /// name. However, it should not bring the parameters into scope;
8354 /// that will be performed by ActOnDelayedCXXMethodParameter.
8355 void Sema::ActOnStartDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
8358 /// ActOnDelayedCXXMethodParameter - We've already started a delayed
8359 /// C++ method declaration. We're (re-)introducing the given
8360 /// function parameter into scope for use in parsing later parts of
8361 /// the method declaration. For example, we could see an
8362 /// ActOnParamDefaultArgument event for this parameter.
8363 void Sema::ActOnDelayedCXXMethodParameter(Scope *S, Decl *ParamD) {
8367 ParmVarDecl *Param = cast<ParmVarDecl>(ParamD);
8369 // If this parameter has an unparsed default argument, clear it out
8370 // to make way for the parsed default argument.
8371 if (Param->hasUnparsedDefaultArg())
8372 Param->setDefaultArg(nullptr);
8375 if (Param->getDeclName())
8376 IdResolver.AddDecl(Param);
8379 /// ActOnFinishDelayedCXXMethodDeclaration - We have finished
8380 /// processing the delayed method declaration for Method. The method
8381 /// declaration is now considered finished. There may be a separate
8382 /// ActOnStartOfFunctionDef action later (not necessarily
8383 /// immediately!) for this method, if it was also defined inside the
8385 void Sema::ActOnFinishDelayedCXXMethodDeclaration(Scope *S, Decl *MethodD) {
8389 AdjustDeclIfTemplate(MethodD);
8391 FunctionDecl *Method = cast<FunctionDecl>(MethodD);
8393 // Now that we have our default arguments, check the constructor
8394 // again. It could produce additional diagnostics or affect whether
8395 // the class has implicitly-declared destructors, among other
8397 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Method))
8398 CheckConstructor(Constructor);
8400 // Check the default arguments, which we may have added.
8401 if (!Method->isInvalidDecl())
8402 CheckCXXDefaultArguments(Method);
8405 // Emit the given diagnostic for each non-address-space qualifier.
8406 // Common part of CheckConstructorDeclarator and CheckDestructorDeclarator.
8407 static void checkMethodTypeQualifiers(Sema &S, Declarator &D, unsigned DiagID) {
8408 const DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
8409 if (FTI.hasMethodTypeQualifiers() && !D.isInvalidType()) {
8410 bool DiagOccured = false;
8411 FTI.MethodQualifiers->forEachQualifier(
8412 [DiagID, &S, &DiagOccured](DeclSpec::TQ, StringRef QualName,
8413 SourceLocation SL) {
8414 // This diagnostic should be emitted on any qualifier except an addr
8415 // space qualifier. However, forEachQualifier currently doesn't visit
8416 // addr space qualifiers, so there's no way to write this condition
8417 // right now; we just diagnose on everything.
8418 S.Diag(SL, DiagID) << QualName << SourceRange(SL);
8426 /// CheckConstructorDeclarator - Called by ActOnDeclarator to check
8427 /// the well-formedness of the constructor declarator @p D with type @p
8428 /// R. If there are any errors in the declarator, this routine will
8429 /// emit diagnostics and set the invalid bit to true. In any case, the type
8430 /// will be updated to reflect a well-formed type for the constructor and
8432 QualType Sema::CheckConstructorDeclarator(Declarator &D, QualType R,
8434 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
8436 // C++ [class.ctor]p3:
8437 // A constructor shall not be virtual (10.3) or static (9.4). A
8438 // constructor can be invoked for a const, volatile or const
8439 // volatile object. A constructor shall not be declared const,
8440 // volatile, or const volatile (9.3.2).
8442 if (!D.isInvalidType())
8443 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
8444 << "virtual" << SourceRange(D.getDeclSpec().getVirtualSpecLoc())
8445 << SourceRange(D.getIdentifierLoc());
8448 if (SC == SC_Static) {
8449 if (!D.isInvalidType())
8450 Diag(D.getIdentifierLoc(), diag::err_constructor_cannot_be)
8451 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
8452 << SourceRange(D.getIdentifierLoc());
8457 if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
8458 diagnoseIgnoredQualifiers(
8459 diag::err_constructor_return_type, TypeQuals, SourceLocation(),
8460 D.getDeclSpec().getConstSpecLoc(), D.getDeclSpec().getVolatileSpecLoc(),
8461 D.getDeclSpec().getRestrictSpecLoc(),
8462 D.getDeclSpec().getAtomicSpecLoc());
8466 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_constructor);
8468 // C++0x [class.ctor]p4:
8469 // A constructor shall not be declared with a ref-qualifier.
8470 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
8471 if (FTI.hasRefQualifier()) {
8472 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_constructor)
8473 << FTI.RefQualifierIsLValueRef
8474 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
8478 // Rebuild the function type "R" without any type qualifiers (in
8479 // case any of the errors above fired) and with "void" as the
8480 // return type, since constructors don't have return types.
8481 const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
8482 if (Proto->getReturnType() == Context.VoidTy && !D.isInvalidType())
8485 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
8486 EPI.TypeQuals = Qualifiers();
8487 EPI.RefQualifier = RQ_None;
8489 return Context.getFunctionType(Context.VoidTy, Proto->getParamTypes(), EPI);
8492 /// CheckConstructor - Checks a fully-formed constructor for
8493 /// well-formedness, issuing any diagnostics required. Returns true if
8494 /// the constructor declarator is invalid.
8495 void Sema::CheckConstructor(CXXConstructorDecl *Constructor) {
8496 CXXRecordDecl *ClassDecl
8497 = dyn_cast<CXXRecordDecl>(Constructor->getDeclContext());
8499 return Constructor->setInvalidDecl();
8501 // C++ [class.copy]p3:
8502 // A declaration of a constructor for a class X is ill-formed if
8503 // its first parameter is of type (optionally cv-qualified) X and
8504 // either there are no other parameters or else all other
8505 // parameters have default arguments.
8506 if (!Constructor->isInvalidDecl() &&
8507 ((Constructor->getNumParams() == 1) ||
8508 (Constructor->getNumParams() > 1 &&
8509 Constructor->getParamDecl(1)->hasDefaultArg())) &&
8510 Constructor->getTemplateSpecializationKind()
8511 != TSK_ImplicitInstantiation) {
8512 QualType ParamType = Constructor->getParamDecl(0)->getType();
8513 QualType ClassTy = Context.getTagDeclType(ClassDecl);
8514 if (Context.getCanonicalType(ParamType).getUnqualifiedType() == ClassTy) {
8515 SourceLocation ParamLoc = Constructor->getParamDecl(0)->getLocation();
8516 const char *ConstRef
8517 = Constructor->getParamDecl(0)->getIdentifier() ? "const &"
8519 Diag(ParamLoc, diag::err_constructor_byvalue_arg)
8520 << FixItHint::CreateInsertion(ParamLoc, ConstRef);
8522 // FIXME: Rather that making the constructor invalid, we should endeavor
8524 Constructor->setInvalidDecl();
8529 /// CheckDestructor - Checks a fully-formed destructor definition for
8530 /// well-formedness, issuing any diagnostics required. Returns true
8532 bool Sema::CheckDestructor(CXXDestructorDecl *Destructor) {
8533 CXXRecordDecl *RD = Destructor->getParent();
8535 if (!Destructor->getOperatorDelete() && Destructor->isVirtual()) {
8538 if (!Destructor->isImplicit())
8539 Loc = Destructor->getLocation();
8541 Loc = RD->getLocation();
8543 // If we have a virtual destructor, look up the deallocation function
8544 if (FunctionDecl *OperatorDelete =
8545 FindDeallocationFunctionForDestructor(Loc, RD)) {
8546 Expr *ThisArg = nullptr;
8548 // If the notional 'delete this' expression requires a non-trivial
8549 // conversion from 'this' to the type of a destroying operator delete's
8550 // first parameter, perform that conversion now.
8551 if (OperatorDelete->isDestroyingOperatorDelete()) {
8552 QualType ParamType = OperatorDelete->getParamDecl(0)->getType();
8553 if (!declaresSameEntity(ParamType->getAsCXXRecordDecl(), RD)) {
8554 // C++ [class.dtor]p13:
8555 // ... as if for the expression 'delete this' appearing in a
8556 // non-virtual destructor of the destructor's class.
8557 ContextRAII SwitchContext(*this, Destructor);
8559 ActOnCXXThis(OperatorDelete->getParamDecl(0)->getLocation());
8560 assert(!This.isInvalid() && "couldn't form 'this' expr in dtor?");
8561 This = PerformImplicitConversion(This.get(), ParamType, AA_Passing);
8562 if (This.isInvalid()) {
8563 // FIXME: Register this as a context note so that it comes out
8564 // in the right order.
8565 Diag(Loc, diag::note_implicit_delete_this_in_destructor_here);
8568 ThisArg = This.get();
8572 DiagnoseUseOfDecl(OperatorDelete, Loc);
8573 MarkFunctionReferenced(Loc, OperatorDelete);
8574 Destructor->setOperatorDelete(OperatorDelete, ThisArg);
8581 /// CheckDestructorDeclarator - Called by ActOnDeclarator to check
8582 /// the well-formednes of the destructor declarator @p D with type @p
8583 /// R. If there are any errors in the declarator, this routine will
8584 /// emit diagnostics and set the declarator to invalid. Even if this happens,
8585 /// will be updated to reflect a well-formed type for the destructor and
8587 QualType Sema::CheckDestructorDeclarator(Declarator &D, QualType R,
8589 // C++ [class.dtor]p1:
8590 // [...] A typedef-name that names a class is a class-name
8591 // (7.1.3); however, a typedef-name that names a class shall not
8592 // be used as the identifier in the declarator for a destructor
8594 QualType DeclaratorType = GetTypeFromParser(D.getName().DestructorName);
8595 if (const TypedefType *TT = DeclaratorType->getAs<TypedefType>())
8596 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
8597 << DeclaratorType << isa<TypeAliasDecl>(TT->getDecl());
8598 else if (const TemplateSpecializationType *TST =
8599 DeclaratorType->getAs<TemplateSpecializationType>())
8600 if (TST->isTypeAlias())
8601 Diag(D.getIdentifierLoc(), diag::err_destructor_typedef_name)
8602 << DeclaratorType << 1;
8604 // C++ [class.dtor]p2:
8605 // A destructor is used to destroy objects of its class type. A
8606 // destructor takes no parameters, and no return type can be
8607 // specified for it (not even void). The address of a destructor
8608 // shall not be taken. A destructor shall not be static. A
8609 // destructor can be invoked for a const, volatile or const
8610 // volatile object. A destructor shall not be declared const,
8611 // volatile or const volatile (9.3.2).
8612 if (SC == SC_Static) {
8613 if (!D.isInvalidType())
8614 Diag(D.getIdentifierLoc(), diag::err_destructor_cannot_be)
8615 << "static" << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
8616 << SourceRange(D.getIdentifierLoc())
8617 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8621 if (!D.isInvalidType()) {
8622 // Destructors don't have return types, but the parser will
8623 // happily parse something like:
8629 // The return type will be eliminated later.
8630 if (D.getDeclSpec().hasTypeSpecifier())
8631 Diag(D.getIdentifierLoc(), diag::err_destructor_return_type)
8632 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
8633 << SourceRange(D.getIdentifierLoc());
8634 else if (unsigned TypeQuals = D.getDeclSpec().getTypeQualifiers()) {
8635 diagnoseIgnoredQualifiers(diag::err_destructor_return_type, TypeQuals,
8637 D.getDeclSpec().getConstSpecLoc(),
8638 D.getDeclSpec().getVolatileSpecLoc(),
8639 D.getDeclSpec().getRestrictSpecLoc(),
8640 D.getDeclSpec().getAtomicSpecLoc());
8645 checkMethodTypeQualifiers(*this, D, diag::err_invalid_qualified_destructor);
8647 // C++0x [class.dtor]p2:
8648 // A destructor shall not be declared with a ref-qualifier.
8649 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
8650 if (FTI.hasRefQualifier()) {
8651 Diag(FTI.getRefQualifierLoc(), diag::err_ref_qualifier_destructor)
8652 << FTI.RefQualifierIsLValueRef
8653 << FixItHint::CreateRemoval(FTI.getRefQualifierLoc());
8657 // Make sure we don't have any parameters.
8658 if (FTIHasNonVoidParameters(FTI)) {
8659 Diag(D.getIdentifierLoc(), diag::err_destructor_with_params);
8661 // Delete the parameters.
8666 // Make sure the destructor isn't variadic.
8667 if (FTI.isVariadic) {
8668 Diag(D.getIdentifierLoc(), diag::err_destructor_variadic);
8672 // Rebuild the function type "R" without any type qualifiers or
8673 // parameters (in case any of the errors above fired) and with
8674 // "void" as the return type, since destructors don't have return
8676 if (!D.isInvalidType())
8679 const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
8680 FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
8681 EPI.Variadic = false;
8682 EPI.TypeQuals = Qualifiers();
8683 EPI.RefQualifier = RQ_None;
8684 return Context.getFunctionType(Context.VoidTy, None, EPI);
8687 static void extendLeft(SourceRange &R, SourceRange Before) {
8688 if (Before.isInvalid())
8690 R.setBegin(Before.getBegin());
8691 if (R.getEnd().isInvalid())
8692 R.setEnd(Before.getEnd());
8695 static void extendRight(SourceRange &R, SourceRange After) {
8696 if (After.isInvalid())
8698 if (R.getBegin().isInvalid())
8699 R.setBegin(After.getBegin());
8700 R.setEnd(After.getEnd());
8703 /// CheckConversionDeclarator - Called by ActOnDeclarator to check the
8704 /// well-formednes of the conversion function declarator @p D with
8705 /// type @p R. If there are any errors in the declarator, this routine
8706 /// will emit diagnostics and return true. Otherwise, it will return
8707 /// false. Either way, the type @p R will be updated to reflect a
8708 /// well-formed type for the conversion operator.
8709 void Sema::CheckConversionDeclarator(Declarator &D, QualType &R,
8711 // C++ [class.conv.fct]p1:
8712 // Neither parameter types nor return type can be specified. The
8713 // type of a conversion function (8.3.5) is "function taking no
8714 // parameter returning conversion-type-id."
8715 if (SC == SC_Static) {
8716 if (!D.isInvalidType())
8717 Diag(D.getIdentifierLoc(), diag::err_conv_function_not_member)
8718 << SourceRange(D.getDeclSpec().getStorageClassSpecLoc())
8719 << D.getName().getSourceRange();
8724 TypeSourceInfo *ConvTSI = nullptr;
8726 GetTypeFromParser(D.getName().ConversionFunctionId, &ConvTSI);
8728 const DeclSpec &DS = D.getDeclSpec();
8729 if (DS.hasTypeSpecifier() && !D.isInvalidType()) {
8730 // Conversion functions don't have return types, but the parser will
8731 // happily parse something like:
8734 // float operator bool();
8737 // The return type will be changed later anyway.
8738 Diag(D.getIdentifierLoc(), diag::err_conv_function_return_type)
8739 << SourceRange(DS.getTypeSpecTypeLoc())
8740 << SourceRange(D.getIdentifierLoc());
8742 } else if (DS.getTypeQualifiers() && !D.isInvalidType()) {
8743 // It's also plausible that the user writes type qualifiers in the wrong
8745 // struct S { const operator int(); };
8746 // FIXME: we could provide a fixit to move the qualifiers onto the
8748 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_complex_decl)
8749 << SourceRange(D.getIdentifierLoc()) << 0;
8753 const FunctionProtoType *Proto = R->getAs<FunctionProtoType>();
8755 // Make sure we don't have any parameters.
8756 if (Proto->getNumParams() > 0) {
8757 Diag(D.getIdentifierLoc(), diag::err_conv_function_with_params);
8759 // Delete the parameters.
8760 D.getFunctionTypeInfo().freeParams();
8762 } else if (Proto->isVariadic()) {
8763 Diag(D.getIdentifierLoc(), diag::err_conv_function_variadic);
8767 // Diagnose "&operator bool()" and other such nonsense. This
8768 // is actually a gcc extension which we don't support.
8769 if (Proto->getReturnType() != ConvType) {
8770 bool NeedsTypedef = false;
8771 SourceRange Before, After;
8773 // Walk the chunks and extract information on them for our diagnostic.
8774 bool PastFunctionChunk = false;
8775 for (auto &Chunk : D.type_objects()) {
8776 switch (Chunk.Kind) {
8777 case DeclaratorChunk::Function:
8778 if (!PastFunctionChunk) {
8779 if (Chunk.Fun.HasTrailingReturnType) {
8780 TypeSourceInfo *TRT = nullptr;
8781 GetTypeFromParser(Chunk.Fun.getTrailingReturnType(), &TRT);
8782 if (TRT) extendRight(After, TRT->getTypeLoc().getSourceRange());
8784 PastFunctionChunk = true;
8788 case DeclaratorChunk::Array:
8789 NeedsTypedef = true;
8790 extendRight(After, Chunk.getSourceRange());
8793 case DeclaratorChunk::Pointer:
8794 case DeclaratorChunk::BlockPointer:
8795 case DeclaratorChunk::Reference:
8796 case DeclaratorChunk::MemberPointer:
8797 case DeclaratorChunk::Pipe:
8798 extendLeft(Before, Chunk.getSourceRange());
8801 case DeclaratorChunk::Paren:
8802 extendLeft(Before, Chunk.Loc);
8803 extendRight(After, Chunk.EndLoc);
8808 SourceLocation Loc = Before.isValid() ? Before.getBegin() :
8809 After.isValid() ? After.getBegin() :
8810 D.getIdentifierLoc();
8811 auto &&DB = Diag(Loc, diag::err_conv_function_with_complex_decl);
8812 DB << Before << After;
8814 if (!NeedsTypedef) {
8815 DB << /*don't need a typedef*/0;
8817 // If we can provide a correct fix-it hint, do so.
8818 if (After.isInvalid() && ConvTSI) {
8819 SourceLocation InsertLoc =
8820 getLocForEndOfToken(ConvTSI->getTypeLoc().getEndLoc());
8821 DB << FixItHint::CreateInsertion(InsertLoc, " ")
8822 << FixItHint::CreateInsertionFromRange(
8823 InsertLoc, CharSourceRange::getTokenRange(Before))
8824 << FixItHint::CreateRemoval(Before);
8826 } else if (!Proto->getReturnType()->isDependentType()) {
8827 DB << /*typedef*/1 << Proto->getReturnType();
8828 } else if (getLangOpts().CPlusPlus11) {
8829 DB << /*alias template*/2 << Proto->getReturnType();
8831 DB << /*might not be fixable*/3;
8834 // Recover by incorporating the other type chunks into the result type.
8835 // Note, this does *not* change the name of the function. This is compatible
8836 // with the GCC extension:
8837 // struct S { &operator int(); } s;
8838 // int &r = s.operator int(); // ok in GCC
8839 // S::operator int&() {} // error in GCC, function name is 'operator int'.
8840 ConvType = Proto->getReturnType();
8843 // C++ [class.conv.fct]p4:
8844 // The conversion-type-id shall not represent a function type nor
8846 if (ConvType->isArrayType()) {
8847 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_array);
8848 ConvType = Context.getPointerType(ConvType);
8850 } else if (ConvType->isFunctionType()) {
8851 Diag(D.getIdentifierLoc(), diag::err_conv_function_to_function);
8852 ConvType = Context.getPointerType(ConvType);
8856 // Rebuild the function type "R" without any parameters (in case any
8857 // of the errors above fired) and with the conversion type as the
8859 if (D.isInvalidType())
8860 R = Context.getFunctionType(ConvType, None, Proto->getExtProtoInfo());
8862 // C++0x explicit conversion operators.
8863 if (DS.hasExplicitSpecifier() && !getLangOpts().CPlusPlus2a)
8864 Diag(DS.getExplicitSpecLoc(),
8865 getLangOpts().CPlusPlus11
8866 ? diag::warn_cxx98_compat_explicit_conversion_functions
8867 : diag::ext_explicit_conversion_functions)
8868 << SourceRange(DS.getExplicitSpecRange());
8871 /// ActOnConversionDeclarator - Called by ActOnDeclarator to complete
8872 /// the declaration of the given C++ conversion function. This routine
8873 /// is responsible for recording the conversion function in the C++
8874 /// class, if possible.
8875 Decl *Sema::ActOnConversionDeclarator(CXXConversionDecl *Conversion) {
8876 assert(Conversion && "Expected to receive a conversion function declaration");
8878 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Conversion->getDeclContext());
8880 // Make sure we aren't redeclaring the conversion function.
8881 QualType ConvType = Context.getCanonicalType(Conversion->getConversionType());
8883 // C++ [class.conv.fct]p1:
8884 // [...] A conversion function is never used to convert a
8885 // (possibly cv-qualified) object to the (possibly cv-qualified)
8886 // same object type (or a reference to it), to a (possibly
8887 // cv-qualified) base class of that type (or a reference to it),
8888 // or to (possibly cv-qualified) void.
8889 // FIXME: Suppress this warning if the conversion function ends up being a
8890 // virtual function that overrides a virtual function in a base class.
8892 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
8893 if (const ReferenceType *ConvTypeRef = ConvType->getAs<ReferenceType>())
8894 ConvType = ConvTypeRef->getPointeeType();
8895 if (Conversion->getTemplateSpecializationKind() != TSK_Undeclared &&
8896 Conversion->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
8897 /* Suppress diagnostics for instantiations. */;
8898 else if (ConvType->isRecordType()) {
8899 ConvType = Context.getCanonicalType(ConvType).getUnqualifiedType();
8900 if (ConvType == ClassType)
8901 Diag(Conversion->getLocation(), diag::warn_conv_to_self_not_used)
8903 else if (IsDerivedFrom(Conversion->getLocation(), ClassType, ConvType))
8904 Diag(Conversion->getLocation(), diag::warn_conv_to_base_not_used)
8905 << ClassType << ConvType;
8906 } else if (ConvType->isVoidType()) {
8907 Diag(Conversion->getLocation(), diag::warn_conv_to_void_not_used)
8908 << ClassType << ConvType;
8911 if (FunctionTemplateDecl *ConversionTemplate
8912 = Conversion->getDescribedFunctionTemplate())
8913 return ConversionTemplate;
8919 /// Utility class to accumulate and print a diagnostic listing the invalid
8920 /// specifier(s) on a declaration.
8921 struct BadSpecifierDiagnoser {
8922 BadSpecifierDiagnoser(Sema &S, SourceLocation Loc, unsigned DiagID)
8923 : S(S), Diagnostic(S.Diag(Loc, DiagID)) {}
8924 ~BadSpecifierDiagnoser() {
8925 Diagnostic << Specifiers;
8928 template<typename T> void check(SourceLocation SpecLoc, T Spec) {
8929 return check(SpecLoc, DeclSpec::getSpecifierName(Spec));
8931 void check(SourceLocation SpecLoc, DeclSpec::TST Spec) {
8932 return check(SpecLoc,
8933 DeclSpec::getSpecifierName(Spec, S.getPrintingPolicy()));
8935 void check(SourceLocation SpecLoc, const char *Spec) {
8936 if (SpecLoc.isInvalid()) return;
8937 Diagnostic << SourceRange(SpecLoc, SpecLoc);
8938 if (!Specifiers.empty()) Specifiers += " ";
8943 Sema::SemaDiagnosticBuilder Diagnostic;
8944 std::string Specifiers;
8948 /// Check the validity of a declarator that we parsed for a deduction-guide.
8949 /// These aren't actually declarators in the grammar, so we need to check that
8950 /// the user didn't specify any pieces that are not part of the deduction-guide
8952 void Sema::CheckDeductionGuideDeclarator(Declarator &D, QualType &R,
8954 TemplateName GuidedTemplate = D.getName().TemplateName.get().get();
8955 TemplateDecl *GuidedTemplateDecl = GuidedTemplate.getAsTemplateDecl();
8956 assert(GuidedTemplateDecl && "missing template decl for deduction guide");
8958 // C++ [temp.deduct.guide]p3:
8959 // A deduction-gide shall be declared in the same scope as the
8960 // corresponding class template.
8961 if (!CurContext->getRedeclContext()->Equals(
8962 GuidedTemplateDecl->getDeclContext()->getRedeclContext())) {
8963 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_wrong_scope)
8964 << GuidedTemplateDecl;
8965 Diag(GuidedTemplateDecl->getLocation(), diag::note_template_decl_here);
8968 auto &DS = D.getMutableDeclSpec();
8969 // We leave 'friend' and 'virtual' to be rejected in the normal way.
8970 if (DS.hasTypeSpecifier() || DS.getTypeQualifiers() ||
8971 DS.getStorageClassSpecLoc().isValid() || DS.isInlineSpecified() ||
8972 DS.isNoreturnSpecified() || DS.hasConstexprSpecifier()) {
8973 BadSpecifierDiagnoser Diagnoser(
8974 *this, D.getIdentifierLoc(),
8975 diag::err_deduction_guide_invalid_specifier);
8977 Diagnoser.check(DS.getStorageClassSpecLoc(), DS.getStorageClassSpec());
8978 DS.ClearStorageClassSpecs();
8981 // 'explicit' is permitted.
8982 Diagnoser.check(DS.getInlineSpecLoc(), "inline");
8983 Diagnoser.check(DS.getNoreturnSpecLoc(), "_Noreturn");
8984 Diagnoser.check(DS.getConstexprSpecLoc(), "constexpr");
8985 DS.ClearConstexprSpec();
8987 Diagnoser.check(DS.getConstSpecLoc(), "const");
8988 Diagnoser.check(DS.getRestrictSpecLoc(), "__restrict");
8989 Diagnoser.check(DS.getVolatileSpecLoc(), "volatile");
8990 Diagnoser.check(DS.getAtomicSpecLoc(), "_Atomic");
8991 Diagnoser.check(DS.getUnalignedSpecLoc(), "__unaligned");
8992 DS.ClearTypeQualifiers();
8994 Diagnoser.check(DS.getTypeSpecComplexLoc(), DS.getTypeSpecComplex());
8995 Diagnoser.check(DS.getTypeSpecSignLoc(), DS.getTypeSpecSign());
8996 Diagnoser.check(DS.getTypeSpecWidthLoc(), DS.getTypeSpecWidth());
8997 Diagnoser.check(DS.getTypeSpecTypeLoc(), DS.getTypeSpecType());
8998 DS.ClearTypeSpecType();
9001 if (D.isInvalidType())
9004 // Check the declarator is simple enough.
9005 bool FoundFunction = false;
9006 for (const DeclaratorChunk &Chunk : llvm::reverse(D.type_objects())) {
9007 if (Chunk.Kind == DeclaratorChunk::Paren)
9009 if (Chunk.Kind != DeclaratorChunk::Function || FoundFunction) {
9010 Diag(D.getDeclSpec().getBeginLoc(),
9011 diag::err_deduction_guide_with_complex_decl)
9012 << D.getSourceRange();
9015 if (!Chunk.Fun.hasTrailingReturnType()) {
9016 Diag(D.getName().getBeginLoc(),
9017 diag::err_deduction_guide_no_trailing_return_type);
9021 // Check that the return type is written as a specialization of
9022 // the template specified as the deduction-guide's name.
9023 ParsedType TrailingReturnType = Chunk.Fun.getTrailingReturnType();
9024 TypeSourceInfo *TSI = nullptr;
9025 QualType RetTy = GetTypeFromParser(TrailingReturnType, &TSI);
9026 assert(TSI && "deduction guide has valid type but invalid return type?");
9027 bool AcceptableReturnType = false;
9028 bool MightInstantiateToSpecialization = false;
9030 TSI->getTypeLoc().getAs<TemplateSpecializationTypeLoc>()) {
9031 TemplateName SpecifiedName = RetTST.getTypePtr()->getTemplateName();
9032 bool TemplateMatches =
9033 Context.hasSameTemplateName(SpecifiedName, GuidedTemplate);
9034 if (SpecifiedName.getKind() == TemplateName::Template && TemplateMatches)
9035 AcceptableReturnType = true;
9037 // This could still instantiate to the right type, unless we know it
9038 // names the wrong class template.
9039 auto *TD = SpecifiedName.getAsTemplateDecl();
9040 MightInstantiateToSpecialization = !(TD && isa<ClassTemplateDecl>(TD) &&
9043 } else if (!RetTy.hasQualifiers() && RetTy->isDependentType()) {
9044 MightInstantiateToSpecialization = true;
9047 if (!AcceptableReturnType) {
9048 Diag(TSI->getTypeLoc().getBeginLoc(),
9049 diag::err_deduction_guide_bad_trailing_return_type)
9050 << GuidedTemplate << TSI->getType()
9051 << MightInstantiateToSpecialization
9052 << TSI->getTypeLoc().getSourceRange();
9055 // Keep going to check that we don't have any inner declarator pieces (we
9056 // could still have a function returning a pointer to a function).
9057 FoundFunction = true;
9060 if (D.isFunctionDefinition())
9061 Diag(D.getIdentifierLoc(), diag::err_deduction_guide_defines_function);
9064 //===----------------------------------------------------------------------===//
9065 // Namespace Handling
9066 //===----------------------------------------------------------------------===//
9068 /// Diagnose a mismatch in 'inline' qualifiers when a namespace is
9070 static void DiagnoseNamespaceInlineMismatch(Sema &S, SourceLocation KeywordLoc,
9072 IdentifierInfo *II, bool *IsInline,
9073 NamespaceDecl *PrevNS) {
9074 assert(*IsInline != PrevNS->isInline());
9076 // HACK: Work around a bug in libstdc++4.6's <atomic>, where
9077 // std::__atomic[0,1,2] are defined as non-inline namespaces, then reopened as
9078 // inline namespaces, with the intention of bringing names into namespace std.
9080 // We support this just well enough to get that case working; this is not
9081 // sufficient to support reopening namespaces as inline in general.
9082 if (*IsInline && II && II->getName().startswith("__atomic") &&
9083 S.getSourceManager().isInSystemHeader(Loc)) {
9084 // Mark all prior declarations of the namespace as inline.
9085 for (NamespaceDecl *NS = PrevNS->getMostRecentDecl(); NS;
9086 NS = NS->getPreviousDecl())
9087 NS->setInline(*IsInline);
9088 // Patch up the lookup table for the containing namespace. This isn't really
9089 // correct, but it's good enough for this particular case.
9090 for (auto *I : PrevNS->decls())
9091 if (auto *ND = dyn_cast<NamedDecl>(I))
9092 PrevNS->getParent()->makeDeclVisibleInContext(ND);
9096 if (PrevNS->isInline())
9097 // The user probably just forgot the 'inline', so suggest that it
9099 S.Diag(Loc, diag::warn_inline_namespace_reopened_noninline)
9100 << FixItHint::CreateInsertion(KeywordLoc, "inline ");
9102 S.Diag(Loc, diag::err_inline_namespace_mismatch);
9104 S.Diag(PrevNS->getLocation(), diag::note_previous_definition);
9105 *IsInline = PrevNS->isInline();
9108 /// ActOnStartNamespaceDef - This is called at the start of a namespace
9110 Decl *Sema::ActOnStartNamespaceDef(
9111 Scope *NamespcScope, SourceLocation InlineLoc, SourceLocation NamespaceLoc,
9112 SourceLocation IdentLoc, IdentifierInfo *II, SourceLocation LBrace,
9113 const ParsedAttributesView &AttrList, UsingDirectiveDecl *&UD) {
9114 SourceLocation StartLoc = InlineLoc.isValid() ? InlineLoc : NamespaceLoc;
9115 // For anonymous namespace, take the location of the left brace.
9116 SourceLocation Loc = II ? IdentLoc : LBrace;
9117 bool IsInline = InlineLoc.isValid();
9118 bool IsInvalid = false;
9120 bool AddToKnown = false;
9121 Scope *DeclRegionScope = NamespcScope->getParent();
9123 NamespaceDecl *PrevNS = nullptr;
9125 // C++ [namespace.def]p2:
9126 // The identifier in an original-namespace-definition shall not
9127 // have been previously defined in the declarative region in
9128 // which the original-namespace-definition appears. The
9129 // identifier in an original-namespace-definition is the name of
9130 // the namespace. Subsequently in that declarative region, it is
9131 // treated as an original-namespace-name.
9133 // Since namespace names are unique in their scope, and we don't
9134 // look through using directives, just look for any ordinary names
9135 // as if by qualified name lookup.
9136 LookupResult R(*this, II, IdentLoc, LookupOrdinaryName,
9137 ForExternalRedeclaration);
9138 LookupQualifiedName(R, CurContext->getRedeclContext());
9139 NamedDecl *PrevDecl =
9140 R.isSingleResult() ? R.getRepresentativeDecl() : nullptr;
9141 PrevNS = dyn_cast_or_null<NamespaceDecl>(PrevDecl);
9144 // This is an extended namespace definition.
9145 if (IsInline != PrevNS->isInline())
9146 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, Loc, II,
9148 } else if (PrevDecl) {
9149 // This is an invalid name redefinition.
9150 Diag(Loc, diag::err_redefinition_different_kind)
9152 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
9154 // Continue on to push Namespc as current DeclContext and return it.
9155 } else if (II->isStr("std") &&
9156 CurContext->getRedeclContext()->isTranslationUnit()) {
9157 // This is the first "real" definition of the namespace "std", so update
9158 // our cache of the "std" namespace to point at this definition.
9159 PrevNS = getStdNamespace();
9161 AddToKnown = !IsInline;
9163 // We've seen this namespace for the first time.
9164 AddToKnown = !IsInline;
9167 // Anonymous namespaces.
9169 // Determine whether the parent already has an anonymous namespace.
9170 DeclContext *Parent = CurContext->getRedeclContext();
9171 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
9172 PrevNS = TU->getAnonymousNamespace();
9174 NamespaceDecl *ND = cast<NamespaceDecl>(Parent);
9175 PrevNS = ND->getAnonymousNamespace();
9178 if (PrevNS && IsInline != PrevNS->isInline())
9179 DiagnoseNamespaceInlineMismatch(*this, NamespaceLoc, NamespaceLoc, II,
9183 NamespaceDecl *Namespc = NamespaceDecl::Create(Context, CurContext, IsInline,
9184 StartLoc, Loc, II, PrevNS);
9186 Namespc->setInvalidDecl();
9188 ProcessDeclAttributeList(DeclRegionScope, Namespc, AttrList);
9189 AddPragmaAttributes(DeclRegionScope, Namespc);
9191 // FIXME: Should we be merging attributes?
9192 if (const VisibilityAttr *Attr = Namespc->getAttr<VisibilityAttr>())
9193 PushNamespaceVisibilityAttr(Attr, Loc);
9196 StdNamespace = Namespc;
9198 KnownNamespaces[Namespc] = false;
9201 PushOnScopeChains(Namespc, DeclRegionScope);
9203 // Link the anonymous namespace into its parent.
9204 DeclContext *Parent = CurContext->getRedeclContext();
9205 if (TranslationUnitDecl *TU = dyn_cast<TranslationUnitDecl>(Parent)) {
9206 TU->setAnonymousNamespace(Namespc);
9208 cast<NamespaceDecl>(Parent)->setAnonymousNamespace(Namespc);
9211 CurContext->addDecl(Namespc);
9213 // C++ [namespace.unnamed]p1. An unnamed-namespace-definition
9214 // behaves as if it were replaced by
9215 // namespace unique { /* empty body */ }
9216 // using namespace unique;
9217 // namespace unique { namespace-body }
9218 // where all occurrences of 'unique' in a translation unit are
9219 // replaced by the same identifier and this identifier differs
9220 // from all other identifiers in the entire program.
9222 // We just create the namespace with an empty name and then add an
9223 // implicit using declaration, just like the standard suggests.
9225 // CodeGen enforces the "universally unique" aspect by giving all
9226 // declarations semantically contained within an anonymous
9227 // namespace internal linkage.
9230 UD = UsingDirectiveDecl::Create(Context, Parent,
9231 /* 'using' */ LBrace,
9232 /* 'namespace' */ SourceLocation(),
9233 /* qualifier */ NestedNameSpecifierLoc(),
9234 /* identifier */ SourceLocation(),
9236 /* Ancestor */ Parent);
9238 Parent->addDecl(UD);
9242 ActOnDocumentableDecl(Namespc);
9244 // Although we could have an invalid decl (i.e. the namespace name is a
9245 // redefinition), push it as current DeclContext and try to continue parsing.
9246 // FIXME: We should be able to push Namespc here, so that the each DeclContext
9247 // for the namespace has the declarations that showed up in that particular
9248 // namespace definition.
9249 PushDeclContext(NamespcScope, Namespc);
9253 /// getNamespaceDecl - Returns the namespace a decl represents. If the decl
9254 /// is a namespace alias, returns the namespace it points to.
9255 static inline NamespaceDecl *getNamespaceDecl(NamedDecl *D) {
9256 if (NamespaceAliasDecl *AD = dyn_cast_or_null<NamespaceAliasDecl>(D))
9257 return AD->getNamespace();
9258 return dyn_cast_or_null<NamespaceDecl>(D);
9261 /// ActOnFinishNamespaceDef - This callback is called after a namespace is
9262 /// exited. Decl is the DeclTy returned by ActOnStartNamespaceDef.
9263 void Sema::ActOnFinishNamespaceDef(Decl *Dcl, SourceLocation RBrace) {
9264 NamespaceDecl *Namespc = dyn_cast_or_null<NamespaceDecl>(Dcl);
9265 assert(Namespc && "Invalid parameter, expected NamespaceDecl");
9266 Namespc->setRBraceLoc(RBrace);
9268 if (Namespc->hasAttr<VisibilityAttr>())
9269 PopPragmaVisibility(true, RBrace);
9270 // If this namespace contains an export-declaration, export it now.
9271 if (DeferredExportedNamespaces.erase(Namespc))
9272 Dcl->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
9275 CXXRecordDecl *Sema::getStdBadAlloc() const {
9276 return cast_or_null<CXXRecordDecl>(
9277 StdBadAlloc.get(Context.getExternalSource()));
9280 EnumDecl *Sema::getStdAlignValT() const {
9281 return cast_or_null<EnumDecl>(StdAlignValT.get(Context.getExternalSource()));
9284 NamespaceDecl *Sema::getStdNamespace() const {
9285 return cast_or_null<NamespaceDecl>(
9286 StdNamespace.get(Context.getExternalSource()));
9289 NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
9290 if (!StdExperimentalNamespaceCache) {
9291 if (auto Std = getStdNamespace()) {
9292 LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
9293 SourceLocation(), LookupNamespaceName);
9294 if (!LookupQualifiedName(Result, Std) ||
9295 !(StdExperimentalNamespaceCache =
9296 Result.getAsSingle<NamespaceDecl>()))
9297 Result.suppressDiagnostics();
9300 return StdExperimentalNamespaceCache;
9305 enum UnsupportedSTLSelect {
9312 struct InvalidSTLDiagnoser {
9315 QualType TyForDiags;
9317 QualType operator()(UnsupportedSTLSelect Sel = USS_Other, StringRef Name = "",
9318 const VarDecl *VD = nullptr) {
9320 auto D = S.Diag(Loc, diag::err_std_compare_type_not_supported)
9321 << TyForDiags << ((int)Sel);
9322 if (Sel == USS_InvalidMember || Sel == USS_MissingMember) {
9323 assert(!Name.empty());
9327 if (Sel == USS_InvalidMember) {
9328 S.Diag(VD->getLocation(), diag::note_var_declared_here)
9329 << VD << VD->getSourceRange();
9336 QualType Sema::CheckComparisonCategoryType(ComparisonCategoryType Kind,
9337 SourceLocation Loc) {
9338 assert(getLangOpts().CPlusPlus &&
9339 "Looking for comparison category type outside of C++.");
9341 // Check if we've already successfully checked the comparison category type
9342 // before. If so, skip checking it again.
9343 ComparisonCategoryInfo *Info = Context.CompCategories.lookupInfo(Kind);
9344 if (Info && FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)])
9345 return Info->getType();
9349 std::string NameForDiags = "std::";
9350 NameForDiags += ComparisonCategories::getCategoryString(Kind);
9351 Diag(Loc, diag::err_implied_comparison_category_type_not_found)
9356 assert(Info->Kind == Kind);
9357 assert(Info->Record);
9359 // Update the Record decl in case we encountered a forward declaration on our
9360 // first pass. FIXME: This is a bit of a hack.
9361 if (Info->Record->hasDefinition())
9362 Info->Record = Info->Record->getDefinition();
9364 // Use an elaborated type for diagnostics which has a name containing the
9365 // prepended 'std' namespace but not any inline namespace names.
9366 QualType TyForDiags = [&]() {
9368 NestedNameSpecifier::Create(Context, nullptr, getStdNamespace());
9369 return Context.getElaboratedType(ETK_None, NNS, Info->getType());
9372 if (RequireCompleteType(Loc, TyForDiags, diag::err_incomplete_type))
9375 InvalidSTLDiagnoser UnsupportedSTLError{*this, Loc, TyForDiags};
9377 if (!Info->Record->isTriviallyCopyable())
9378 return UnsupportedSTLError(USS_NonTrivial);
9380 for (const CXXBaseSpecifier &BaseSpec : Info->Record->bases()) {
9381 CXXRecordDecl *Base = BaseSpec.getType()->getAsCXXRecordDecl();
9382 // Tolerate empty base classes.
9383 if (Base->isEmpty())
9385 // Reject STL implementations which have at least one non-empty base.
9386 return UnsupportedSTLError();
9389 // Check that the STL has implemented the types using a single integer field.
9390 // This expectation allows better codegen for builtin operators. We require:
9391 // (1) The class has exactly one field.
9392 // (2) The field is an integral or enumeration type.
9393 auto FIt = Info->Record->field_begin(), FEnd = Info->Record->field_end();
9394 if (std::distance(FIt, FEnd) != 1 ||
9395 !FIt->getType()->isIntegralOrEnumerationType()) {
9396 return UnsupportedSTLError();
9399 // Build each of the require values and store them in Info.
9400 for (ComparisonCategoryResult CCR :
9401 ComparisonCategories::getPossibleResultsForType(Kind)) {
9402 StringRef MemName = ComparisonCategories::getResultString(CCR);
9403 ComparisonCategoryInfo::ValueInfo *ValInfo = Info->lookupValueInfo(CCR);
9406 return UnsupportedSTLError(USS_MissingMember, MemName);
9408 VarDecl *VD = ValInfo->VD;
9409 assert(VD && "should not be null!");
9411 // Attempt to diagnose reasons why the STL definition of this type
9412 // might be foobar, including it failing to be a constant expression.
9413 // TODO Handle more ways the lookup or result can be invalid.
9414 if (!VD->isStaticDataMember() || !VD->isConstexpr() || !VD->hasInit() ||
9415 !VD->checkInitIsICE())
9416 return UnsupportedSTLError(USS_InvalidMember, MemName, VD);
9418 // Attempt to evaluate the var decl as a constant expression and extract
9419 // the value of its first field as a ICE. If this fails, the STL
9420 // implementation is not supported.
9421 if (!ValInfo->hasValidIntValue())
9422 return UnsupportedSTLError();
9424 MarkVariableReferenced(Loc, VD);
9427 // We've successfully built the required types and expressions. Update
9428 // the cache and return the newly cached value.
9429 FullyCheckedComparisonCategories[static_cast<unsigned>(Kind)] = true;
9430 return Info->getType();
9433 /// Retrieve the special "std" namespace, which may require us to
9434 /// implicitly define the namespace.
9435 NamespaceDecl *Sema::getOrCreateStdNamespace() {
9436 if (!StdNamespace) {
9437 // The "std" namespace has not yet been defined, so build one implicitly.
9438 StdNamespace = NamespaceDecl::Create(Context,
9439 Context.getTranslationUnitDecl(),
9441 SourceLocation(), SourceLocation(),
9442 &PP.getIdentifierTable().get("std"),
9443 /*PrevDecl=*/nullptr);
9444 getStdNamespace()->setImplicit(true);
9447 return getStdNamespace();
9450 bool Sema::isStdInitializerList(QualType Ty, QualType *Element) {
9451 assert(getLangOpts().CPlusPlus &&
9452 "Looking for std::initializer_list outside of C++.");
9454 // We're looking for implicit instantiations of
9455 // template <typename E> class std::initializer_list.
9457 if (!StdNamespace) // If we haven't seen namespace std yet, this can't be it.
9460 ClassTemplateDecl *Template = nullptr;
9461 const TemplateArgument *Arguments = nullptr;
9463 if (const RecordType *RT = Ty->getAs<RecordType>()) {
9465 ClassTemplateSpecializationDecl *Specialization =
9466 dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
9467 if (!Specialization)
9470 Template = Specialization->getSpecializedTemplate();
9471 Arguments = Specialization->getTemplateArgs().data();
9472 } else if (const TemplateSpecializationType *TST =
9473 Ty->getAs<TemplateSpecializationType>()) {
9474 Template = dyn_cast_or_null<ClassTemplateDecl>(
9475 TST->getTemplateName().getAsTemplateDecl());
9476 Arguments = TST->getArgs();
9481 if (!StdInitializerList) {
9482 // Haven't recognized std::initializer_list yet, maybe this is it.
9483 CXXRecordDecl *TemplateClass = Template->getTemplatedDecl();
9484 if (TemplateClass->getIdentifier() !=
9485 &PP.getIdentifierTable().get("initializer_list") ||
9486 !getStdNamespace()->InEnclosingNamespaceSetOf(
9487 TemplateClass->getDeclContext()))
9489 // This is a template called std::initializer_list, but is it the right
9491 TemplateParameterList *Params = Template->getTemplateParameters();
9492 if (Params->getMinRequiredArguments() != 1)
9494 if (!isa<TemplateTypeParmDecl>(Params->getParam(0)))
9497 // It's the right template.
9498 StdInitializerList = Template;
9501 if (Template->getCanonicalDecl() != StdInitializerList->getCanonicalDecl())
9504 // This is an instance of std::initializer_list. Find the argument type.
9506 *Element = Arguments[0].getAsType();
9510 static ClassTemplateDecl *LookupStdInitializerList(Sema &S, SourceLocation Loc){
9511 NamespaceDecl *Std = S.getStdNamespace();
9513 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
9517 LookupResult Result(S, &S.PP.getIdentifierTable().get("initializer_list"),
9518 Loc, Sema::LookupOrdinaryName);
9519 if (!S.LookupQualifiedName(Result, Std)) {
9520 S.Diag(Loc, diag::err_implied_std_initializer_list_not_found);
9523 ClassTemplateDecl *Template = Result.getAsSingle<ClassTemplateDecl>();
9525 Result.suppressDiagnostics();
9526 // We found something weird. Complain about the first thing we found.
9527 NamedDecl *Found = *Result.begin();
9528 S.Diag(Found->getLocation(), diag::err_malformed_std_initializer_list);
9532 // We found some template called std::initializer_list. Now verify that it's
9534 TemplateParameterList *Params = Template->getTemplateParameters();
9535 if (Params->getMinRequiredArguments() != 1 ||
9536 !isa<TemplateTypeParmDecl>(Params->getParam(0))) {
9537 S.Diag(Template->getLocation(), diag::err_malformed_std_initializer_list);
9544 QualType Sema::BuildStdInitializerList(QualType Element, SourceLocation Loc) {
9545 if (!StdInitializerList) {
9546 StdInitializerList = LookupStdInitializerList(*this, Loc);
9547 if (!StdInitializerList)
9551 TemplateArgumentListInfo Args(Loc, Loc);
9552 Args.addArgument(TemplateArgumentLoc(TemplateArgument(Element),
9553 Context.getTrivialTypeSourceInfo(Element,
9555 return Context.getCanonicalType(
9556 CheckTemplateIdType(TemplateName(StdInitializerList), Loc, Args));
9559 bool Sema::isInitListConstructor(const FunctionDecl *Ctor) {
9560 // C++ [dcl.init.list]p2:
9561 // A constructor is an initializer-list constructor if its first parameter
9562 // is of type std::initializer_list<E> or reference to possibly cv-qualified
9563 // std::initializer_list<E> for some type E, and either there are no other
9564 // parameters or else all other parameters have default arguments.
9565 if (Ctor->getNumParams() < 1 ||
9566 (Ctor->getNumParams() > 1 && !Ctor->getParamDecl(1)->hasDefaultArg()))
9569 QualType ArgType = Ctor->getParamDecl(0)->getType();
9570 if (const ReferenceType *RT = ArgType->getAs<ReferenceType>())
9571 ArgType = RT->getPointeeType().getUnqualifiedType();
9573 return isStdInitializerList(ArgType, nullptr);
9576 /// Determine whether a using statement is in a context where it will be
9577 /// apply in all contexts.
9578 static bool IsUsingDirectiveInToplevelContext(DeclContext *CurContext) {
9579 switch (CurContext->getDeclKind()) {
9580 case Decl::TranslationUnit:
9582 case Decl::LinkageSpec:
9583 return IsUsingDirectiveInToplevelContext(CurContext->getParent());
9591 // Callback to only accept typo corrections that are namespaces.
9592 class NamespaceValidatorCCC final : public CorrectionCandidateCallback {
9594 bool ValidateCandidate(const TypoCorrection &candidate) override {
9595 if (NamedDecl *ND = candidate.getCorrectionDecl())
9596 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
9600 std::unique_ptr<CorrectionCandidateCallback> clone() override {
9601 return std::make_unique<NamespaceValidatorCCC>(*this);
9607 static bool TryNamespaceTypoCorrection(Sema &S, LookupResult &R, Scope *Sc,
9609 SourceLocation IdentLoc,
9610 IdentifierInfo *Ident) {
9612 NamespaceValidatorCCC CCC{};
9613 if (TypoCorrection Corrected =
9614 S.CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), Sc, &SS, CCC,
9615 Sema::CTK_ErrorRecovery)) {
9616 if (DeclContext *DC = S.computeDeclContext(SS, false)) {
9617 std::string CorrectedStr(Corrected.getAsString(S.getLangOpts()));
9618 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
9619 Ident->getName().equals(CorrectedStr);
9620 S.diagnoseTypo(Corrected,
9621 S.PDiag(diag::err_using_directive_member_suggest)
9622 << Ident << DC << DroppedSpecifier << SS.getRange(),
9623 S.PDiag(diag::note_namespace_defined_here));
9625 S.diagnoseTypo(Corrected,
9626 S.PDiag(diag::err_using_directive_suggest) << Ident,
9627 S.PDiag(diag::note_namespace_defined_here));
9629 R.addDecl(Corrected.getFoundDecl());
9635 Decl *Sema::ActOnUsingDirective(Scope *S, SourceLocation UsingLoc,
9636 SourceLocation NamespcLoc, CXXScopeSpec &SS,
9637 SourceLocation IdentLoc,
9638 IdentifierInfo *NamespcName,
9639 const ParsedAttributesView &AttrList) {
9640 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
9641 assert(NamespcName && "Invalid NamespcName.");
9642 assert(IdentLoc.isValid() && "Invalid NamespceName location.");
9644 // This can only happen along a recovery path.
9645 while (S->isTemplateParamScope())
9647 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
9649 UsingDirectiveDecl *UDir = nullptr;
9650 NestedNameSpecifier *Qualifier = nullptr;
9652 Qualifier = SS.getScopeRep();
9654 // Lookup namespace name.
9655 LookupResult R(*this, NamespcName, IdentLoc, LookupNamespaceName);
9656 LookupParsedName(R, S, &SS);
9657 if (R.isAmbiguous())
9662 // Allow "using namespace std;" or "using namespace ::std;" even if
9663 // "std" hasn't been defined yet, for GCC compatibility.
9664 if ((!Qualifier || Qualifier->getKind() == NestedNameSpecifier::Global) &&
9665 NamespcName->isStr("std")) {
9666 Diag(IdentLoc, diag::ext_using_undefined_std);
9667 R.addDecl(getOrCreateStdNamespace());
9670 // Otherwise, attempt typo correction.
9671 else TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, NamespcName);
9675 NamedDecl *Named = R.getRepresentativeDecl();
9676 NamespaceDecl *NS = R.getAsSingle<NamespaceDecl>();
9677 assert(NS && "expected namespace decl");
9679 // The use of a nested name specifier may trigger deprecation warnings.
9680 DiagnoseUseOfDecl(Named, IdentLoc);
9682 // C++ [namespace.udir]p1:
9683 // A using-directive specifies that the names in the nominated
9684 // namespace can be used in the scope in which the
9685 // using-directive appears after the using-directive. During
9686 // unqualified name lookup (3.4.1), the names appear as if they
9687 // were declared in the nearest enclosing namespace which
9688 // contains both the using-directive and the nominated
9689 // namespace. [Note: in this context, "contains" means "contains
9690 // directly or indirectly". ]
9692 // Find enclosing context containing both using-directive and
9693 // nominated namespace.
9694 DeclContext *CommonAncestor = NS;
9695 while (CommonAncestor && !CommonAncestor->Encloses(CurContext))
9696 CommonAncestor = CommonAncestor->getParent();
9698 UDir = UsingDirectiveDecl::Create(Context, CurContext, UsingLoc, NamespcLoc,
9699 SS.getWithLocInContext(Context),
9700 IdentLoc, Named, CommonAncestor);
9702 if (IsUsingDirectiveInToplevelContext(CurContext) &&
9703 !SourceMgr.isInMainFile(SourceMgr.getExpansionLoc(IdentLoc))) {
9704 Diag(IdentLoc, diag::warn_using_directive_in_header);
9707 PushUsingDirective(S, UDir);
9709 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
9713 ProcessDeclAttributeList(S, UDir, AttrList);
9718 void Sema::PushUsingDirective(Scope *S, UsingDirectiveDecl *UDir) {
9719 // If the scope has an associated entity and the using directive is at
9720 // namespace or translation unit scope, add the UsingDirectiveDecl into
9721 // its lookup structure so qualified name lookup can find it.
9722 DeclContext *Ctx = S->getEntity();
9723 if (Ctx && !Ctx->isFunctionOrMethod())
9726 // Otherwise, it is at block scope. The using-directives will affect lookup
9727 // only to the end of the scope.
9728 S->PushUsingDirective(UDir);
9731 Decl *Sema::ActOnUsingDeclaration(Scope *S, AccessSpecifier AS,
9732 SourceLocation UsingLoc,
9733 SourceLocation TypenameLoc, CXXScopeSpec &SS,
9734 UnqualifiedId &Name,
9735 SourceLocation EllipsisLoc,
9736 const ParsedAttributesView &AttrList) {
9737 assert(S->getFlags() & Scope::DeclScope && "Invalid Scope.");
9740 Diag(Name.getBeginLoc(), diag::err_using_requires_qualname);
9744 switch (Name.getKind()) {
9745 case UnqualifiedIdKind::IK_ImplicitSelfParam:
9746 case UnqualifiedIdKind::IK_Identifier:
9747 case UnqualifiedIdKind::IK_OperatorFunctionId:
9748 case UnqualifiedIdKind::IK_LiteralOperatorId:
9749 case UnqualifiedIdKind::IK_ConversionFunctionId:
9752 case UnqualifiedIdKind::IK_ConstructorName:
9753 case UnqualifiedIdKind::IK_ConstructorTemplateId:
9754 // C++11 inheriting constructors.
9755 Diag(Name.getBeginLoc(),
9756 getLangOpts().CPlusPlus11
9757 ? diag::warn_cxx98_compat_using_decl_constructor
9758 : diag::err_using_decl_constructor)
9761 if (getLangOpts().CPlusPlus11) break;
9765 case UnqualifiedIdKind::IK_DestructorName:
9766 Diag(Name.getBeginLoc(), diag::err_using_decl_destructor) << SS.getRange();
9769 case UnqualifiedIdKind::IK_TemplateId:
9770 Diag(Name.getBeginLoc(), diag::err_using_decl_template_id)
9771 << SourceRange(Name.TemplateId->LAngleLoc, Name.TemplateId->RAngleLoc);
9774 case UnqualifiedIdKind::IK_DeductionGuideName:
9775 llvm_unreachable("cannot parse qualified deduction guide name");
9778 DeclarationNameInfo TargetNameInfo = GetNameFromUnqualifiedId(Name);
9779 DeclarationName TargetName = TargetNameInfo.getName();
9783 // Warn about access declarations.
9784 if (UsingLoc.isInvalid()) {
9785 Diag(Name.getBeginLoc(), getLangOpts().CPlusPlus11
9786 ? diag::err_access_decl
9787 : diag::warn_access_decl_deprecated)
9788 << FixItHint::CreateInsertion(SS.getRange().getBegin(), "using ");
9791 if (EllipsisLoc.isInvalid()) {
9792 if (DiagnoseUnexpandedParameterPack(SS, UPPC_UsingDeclaration) ||
9793 DiagnoseUnexpandedParameterPack(TargetNameInfo, UPPC_UsingDeclaration))
9796 if (!SS.getScopeRep()->containsUnexpandedParameterPack() &&
9797 !TargetNameInfo.containsUnexpandedParameterPack()) {
9798 Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
9799 << SourceRange(SS.getBeginLoc(), TargetNameInfo.getEndLoc());
9800 EllipsisLoc = SourceLocation();
9805 BuildUsingDeclaration(S, AS, UsingLoc, TypenameLoc.isValid(), TypenameLoc,
9806 SS, TargetNameInfo, EllipsisLoc, AttrList,
9807 /*IsInstantiation*/false);
9809 PushOnScopeChains(UD, S, /*AddToContext*/ false);
9814 /// Determine whether a using declaration considers the given
9815 /// declarations as "equivalent", e.g., if they are redeclarations of
9816 /// the same entity or are both typedefs of the same type.
9818 IsEquivalentForUsingDecl(ASTContext &Context, NamedDecl *D1, NamedDecl *D2) {
9819 if (D1->getCanonicalDecl() == D2->getCanonicalDecl())
9822 if (TypedefNameDecl *TD1 = dyn_cast<TypedefNameDecl>(D1))
9823 if (TypedefNameDecl *TD2 = dyn_cast<TypedefNameDecl>(D2))
9824 return Context.hasSameType(TD1->getUnderlyingType(),
9825 TD2->getUnderlyingType());
9831 /// Determines whether to create a using shadow decl for a particular
9832 /// decl, given the set of decls existing prior to this using lookup.
9833 bool Sema::CheckUsingShadowDecl(UsingDecl *Using, NamedDecl *Orig,
9834 const LookupResult &Previous,
9835 UsingShadowDecl *&PrevShadow) {
9836 // Diagnose finding a decl which is not from a base class of the
9837 // current class. We do this now because there are cases where this
9838 // function will silently decide not to build a shadow decl, which
9839 // will pre-empt further diagnostics.
9841 // We don't need to do this in C++11 because we do the check once on
9844 // FIXME: diagnose the following if we care enough:
9845 // struct A { int foo; };
9846 // struct B : A { using A::foo; };
9847 // template <class T> struct C : A {};
9848 // template <class T> struct D : C<T> { using B::foo; } // <---
9849 // This is invalid (during instantiation) in C++03 because B::foo
9850 // resolves to the using decl in B, which is not a base class of D<T>.
9851 // We can't diagnose it immediately because C<T> is an unknown
9852 // specialization. The UsingShadowDecl in D<T> then points directly
9853 // to A::foo, which will look well-formed when we instantiate.
9854 // The right solution is to not collapse the shadow-decl chain.
9855 if (!getLangOpts().CPlusPlus11 && CurContext->isRecord()) {
9856 DeclContext *OrigDC = Orig->getDeclContext();
9858 // Handle enums and anonymous structs.
9859 if (isa<EnumDecl>(OrigDC)) OrigDC = OrigDC->getParent();
9860 CXXRecordDecl *OrigRec = cast<CXXRecordDecl>(OrigDC);
9861 while (OrigRec->isAnonymousStructOrUnion())
9862 OrigRec = cast<CXXRecordDecl>(OrigRec->getDeclContext());
9864 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(OrigRec)) {
9865 if (OrigDC == CurContext) {
9866 Diag(Using->getLocation(),
9867 diag::err_using_decl_nested_name_specifier_is_current_class)
9868 << Using->getQualifierLoc().getSourceRange();
9869 Diag(Orig->getLocation(), diag::note_using_decl_target);
9870 Using->setInvalidDecl();
9874 Diag(Using->getQualifierLoc().getBeginLoc(),
9875 diag::err_using_decl_nested_name_specifier_is_not_base_class)
9876 << Using->getQualifier()
9877 << cast<CXXRecordDecl>(CurContext)
9878 << Using->getQualifierLoc().getSourceRange();
9879 Diag(Orig->getLocation(), diag::note_using_decl_target);
9880 Using->setInvalidDecl();
9885 if (Previous.empty()) return false;
9887 NamedDecl *Target = Orig;
9888 if (isa<UsingShadowDecl>(Target))
9889 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
9891 // If the target happens to be one of the previous declarations, we
9892 // don't have a conflict.
9894 // FIXME: but we might be increasing its access, in which case we
9895 // should redeclare it.
9896 NamedDecl *NonTag = nullptr, *Tag = nullptr;
9897 bool FoundEquivalentDecl = false;
9898 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
9900 NamedDecl *D = (*I)->getUnderlyingDecl();
9901 // We can have UsingDecls in our Previous results because we use the same
9902 // LookupResult for checking whether the UsingDecl itself is a valid
9904 if (isa<UsingDecl>(D) || isa<UsingPackDecl>(D))
9907 if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
9908 // C++ [class.mem]p19:
9909 // If T is the name of a class, then [every named member other than
9910 // a non-static data member] shall have a name different from T
9911 if (RD->isInjectedClassName() && !isa<FieldDecl>(Target) &&
9912 !isa<IndirectFieldDecl>(Target) &&
9913 !isa<UnresolvedUsingValueDecl>(Target) &&
9914 DiagnoseClassNameShadow(
9916 DeclarationNameInfo(Using->getDeclName(), Using->getLocation())))
9920 if (IsEquivalentForUsingDecl(Context, D, Target)) {
9921 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(*I))
9922 PrevShadow = Shadow;
9923 FoundEquivalentDecl = true;
9924 } else if (isEquivalentInternalLinkageDeclaration(D, Target)) {
9925 // We don't conflict with an existing using shadow decl of an equivalent
9926 // declaration, but we're not a redeclaration of it.
9927 FoundEquivalentDecl = true;
9931 (isa<TagDecl>(D) ? Tag : NonTag) = D;
9934 if (FoundEquivalentDecl)
9937 if (FunctionDecl *FD = Target->getAsFunction()) {
9938 NamedDecl *OldDecl = nullptr;
9939 switch (CheckOverload(nullptr, FD, Previous, OldDecl,
9940 /*IsForUsingDecl*/ true)) {
9944 case Ovl_NonFunction:
9945 Diag(Using->getLocation(), diag::err_using_decl_conflict);
9948 // We found a decl with the exact signature.
9950 // If we're in a record, we want to hide the target, so we
9951 // return true (without a diagnostic) to tell the caller not to
9952 // build a shadow decl.
9953 if (CurContext->isRecord())
9956 // If we're not in a record, this is an error.
9957 Diag(Using->getLocation(), diag::err_using_decl_conflict);
9961 Diag(Target->getLocation(), diag::note_using_decl_target);
9962 Diag(OldDecl->getLocation(), diag::note_using_decl_conflict);
9963 Using->setInvalidDecl();
9967 // Target is not a function.
9969 if (isa<TagDecl>(Target)) {
9970 // No conflict between a tag and a non-tag.
9971 if (!Tag) return false;
9973 Diag(Using->getLocation(), diag::err_using_decl_conflict);
9974 Diag(Target->getLocation(), diag::note_using_decl_target);
9975 Diag(Tag->getLocation(), diag::note_using_decl_conflict);
9976 Using->setInvalidDecl();
9980 // No conflict between a tag and a non-tag.
9981 if (!NonTag) return false;
9983 Diag(Using->getLocation(), diag::err_using_decl_conflict);
9984 Diag(Target->getLocation(), diag::note_using_decl_target);
9985 Diag(NonTag->getLocation(), diag::note_using_decl_conflict);
9986 Using->setInvalidDecl();
9990 /// Determine whether a direct base class is a virtual base class.
9991 static bool isVirtualDirectBase(CXXRecordDecl *Derived, CXXRecordDecl *Base) {
9992 if (!Derived->getNumVBases())
9994 for (auto &B : Derived->bases())
9995 if (B.getType()->getAsCXXRecordDecl() == Base)
9996 return B.isVirtual();
9997 llvm_unreachable("not a direct base class");
10000 /// Builds a shadow declaration corresponding to a 'using' declaration.
10001 UsingShadowDecl *Sema::BuildUsingShadowDecl(Scope *S,
10004 UsingShadowDecl *PrevDecl) {
10005 // If we resolved to another shadow declaration, just coalesce them.
10006 NamedDecl *Target = Orig;
10007 if (isa<UsingShadowDecl>(Target)) {
10008 Target = cast<UsingShadowDecl>(Target)->getTargetDecl();
10009 assert(!isa<UsingShadowDecl>(Target) && "nested shadow declaration");
10012 NamedDecl *NonTemplateTarget = Target;
10013 if (auto *TargetTD = dyn_cast<TemplateDecl>(Target))
10014 NonTemplateTarget = TargetTD->getTemplatedDecl();
10016 UsingShadowDecl *Shadow;
10017 if (NonTemplateTarget && isa<CXXConstructorDecl>(NonTemplateTarget)) {
10018 bool IsVirtualBase =
10019 isVirtualDirectBase(cast<CXXRecordDecl>(CurContext),
10020 UD->getQualifier()->getAsRecordDecl());
10021 Shadow = ConstructorUsingShadowDecl::Create(
10022 Context, CurContext, UD->getLocation(), UD, Orig, IsVirtualBase);
10024 Shadow = UsingShadowDecl::Create(Context, CurContext, UD->getLocation(), UD,
10027 UD->addShadowDecl(Shadow);
10029 Shadow->setAccess(UD->getAccess());
10030 if (Orig->isInvalidDecl() || UD->isInvalidDecl())
10031 Shadow->setInvalidDecl();
10033 Shadow->setPreviousDecl(PrevDecl);
10036 PushOnScopeChains(Shadow, S);
10038 CurContext->addDecl(Shadow);
10044 /// Hides a using shadow declaration. This is required by the current
10045 /// using-decl implementation when a resolvable using declaration in a
10046 /// class is followed by a declaration which would hide or override
10047 /// one or more of the using decl's targets; for example:
10049 /// struct Base { void foo(int); };
10050 /// struct Derived : Base {
10051 /// using Base::foo;
10055 /// The governing language is C++03 [namespace.udecl]p12:
10057 /// When a using-declaration brings names from a base class into a
10058 /// derived class scope, member functions in the derived class
10059 /// override and/or hide member functions with the same name and
10060 /// parameter types in a base class (rather than conflicting).
10062 /// There are two ways to implement this:
10063 /// (1) optimistically create shadow decls when they're not hidden
10064 /// by existing declarations, or
10065 /// (2) don't create any shadow decls (or at least don't make them
10066 /// visible) until we've fully parsed/instantiated the class.
10067 /// The problem with (1) is that we might have to retroactively remove
10068 /// a shadow decl, which requires several O(n) operations because the
10069 /// decl structures are (very reasonably) not designed for removal.
10070 /// (2) avoids this but is very fiddly and phase-dependent.
10071 void Sema::HideUsingShadowDecl(Scope *S, UsingShadowDecl *Shadow) {
10072 if (Shadow->getDeclName().getNameKind() ==
10073 DeclarationName::CXXConversionFunctionName)
10074 cast<CXXRecordDecl>(Shadow->getDeclContext())->removeConversion(Shadow);
10076 // Remove it from the DeclContext...
10077 Shadow->getDeclContext()->removeDecl(Shadow);
10079 // ...and the scope, if applicable...
10081 S->RemoveDecl(Shadow);
10082 IdResolver.RemoveDecl(Shadow);
10085 // ...and the using decl.
10086 Shadow->getUsingDecl()->removeShadowDecl(Shadow);
10088 // TODO: complain somehow if Shadow was used. It shouldn't
10089 // be possible for this to happen, because...?
10092 /// Find the base specifier for a base class with the given type.
10093 static CXXBaseSpecifier *findDirectBaseWithType(CXXRecordDecl *Derived,
10094 QualType DesiredBase,
10095 bool &AnyDependentBases) {
10096 // Check whether the named type is a direct base class.
10097 CanQualType CanonicalDesiredBase = DesiredBase->getCanonicalTypeUnqualified()
10098 .getUnqualifiedType();
10099 for (auto &Base : Derived->bases()) {
10100 CanQualType BaseType = Base.getType()->getCanonicalTypeUnqualified();
10101 if (CanonicalDesiredBase == BaseType)
10103 if (BaseType->isDependentType())
10104 AnyDependentBases = true;
10110 class UsingValidatorCCC final : public CorrectionCandidateCallback {
10112 UsingValidatorCCC(bool HasTypenameKeyword, bool IsInstantiation,
10113 NestedNameSpecifier *NNS, CXXRecordDecl *RequireMemberOf)
10114 : HasTypenameKeyword(HasTypenameKeyword),
10115 IsInstantiation(IsInstantiation), OldNNS(NNS),
10116 RequireMemberOf(RequireMemberOf) {}
10118 bool ValidateCandidate(const TypoCorrection &Candidate) override {
10119 NamedDecl *ND = Candidate.getCorrectionDecl();
10121 // Keywords are not valid here.
10122 if (!ND || isa<NamespaceDecl>(ND))
10125 // Completely unqualified names are invalid for a 'using' declaration.
10126 if (Candidate.WillReplaceSpecifier() && !Candidate.getCorrectionSpecifier())
10129 // FIXME: Don't correct to a name that CheckUsingDeclRedeclaration would
10132 if (RequireMemberOf) {
10133 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
10134 if (FoundRecord && FoundRecord->isInjectedClassName()) {
10135 // No-one ever wants a using-declaration to name an injected-class-name
10136 // of a base class, unless they're declaring an inheriting constructor.
10137 ASTContext &Ctx = ND->getASTContext();
10138 if (!Ctx.getLangOpts().CPlusPlus11)
10140 QualType FoundType = Ctx.getRecordType(FoundRecord);
10142 // Check that the injected-class-name is named as a member of its own
10143 // type; we don't want to suggest 'using Derived::Base;', since that
10144 // means something else.
10145 NestedNameSpecifier *Specifier =
10146 Candidate.WillReplaceSpecifier()
10147 ? Candidate.getCorrectionSpecifier()
10149 if (!Specifier->getAsType() ||
10150 !Ctx.hasSameType(QualType(Specifier->getAsType(), 0), FoundType))
10153 // Check that this inheriting constructor declaration actually names a
10154 // direct base class of the current class.
10155 bool AnyDependentBases = false;
10156 if (!findDirectBaseWithType(RequireMemberOf,
10157 Ctx.getRecordType(FoundRecord),
10158 AnyDependentBases) &&
10159 !AnyDependentBases)
10162 auto *RD = dyn_cast<CXXRecordDecl>(ND->getDeclContext());
10163 if (!RD || RequireMemberOf->isProvablyNotDerivedFrom(RD))
10166 // FIXME: Check that the base class member is accessible?
10169 auto *FoundRecord = dyn_cast<CXXRecordDecl>(ND);
10170 if (FoundRecord && FoundRecord->isInjectedClassName())
10174 if (isa<TypeDecl>(ND))
10175 return HasTypenameKeyword || !IsInstantiation;
10177 return !HasTypenameKeyword;
10180 std::unique_ptr<CorrectionCandidateCallback> clone() override {
10181 return std::make_unique<UsingValidatorCCC>(*this);
10185 bool HasTypenameKeyword;
10186 bool IsInstantiation;
10187 NestedNameSpecifier *OldNNS;
10188 CXXRecordDecl *RequireMemberOf;
10190 } // end anonymous namespace
10192 /// Builds a using declaration.
10194 /// \param IsInstantiation - Whether this call arises from an
10195 /// instantiation of an unresolved using declaration. We treat
10196 /// the lookup differently for these declarations.
10197 NamedDecl *Sema::BuildUsingDeclaration(
10198 Scope *S, AccessSpecifier AS, SourceLocation UsingLoc,
10199 bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS,
10200 DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc,
10201 const ParsedAttributesView &AttrList, bool IsInstantiation) {
10202 assert(!SS.isInvalid() && "Invalid CXXScopeSpec.");
10203 SourceLocation IdentLoc = NameInfo.getLoc();
10204 assert(IdentLoc.isValid() && "Invalid TargetName location.");
10206 // FIXME: We ignore attributes for now.
10208 // For an inheriting constructor declaration, the name of the using
10209 // declaration is the name of a constructor in this class, not in the
10211 DeclarationNameInfo UsingName = NameInfo;
10212 if (UsingName.getName().getNameKind() == DeclarationName::CXXConstructorName)
10213 if (auto *RD = dyn_cast<CXXRecordDecl>(CurContext))
10214 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
10215 Context.getCanonicalType(Context.getRecordType(RD))));
10217 // Do the redeclaration lookup in the current scope.
10218 LookupResult Previous(*this, UsingName, LookupUsingDeclName,
10219 ForVisibleRedeclaration);
10220 Previous.setHideTags(false);
10222 LookupName(Previous, S);
10224 // It is really dumb that we have to do this.
10225 LookupResult::Filter F = Previous.makeFilter();
10226 while (F.hasNext()) {
10227 NamedDecl *D = F.next();
10228 if (!isDeclInScope(D, CurContext, S))
10230 // If we found a local extern declaration that's not ordinarily visible,
10231 // and this declaration is being added to a non-block scope, ignore it.
10232 // We're only checking for scope conflicts here, not also for violations
10233 // of the linkage rules.
10234 else if (!CurContext->isFunctionOrMethod() && D->isLocalExternDecl() &&
10235 !(D->getIdentifierNamespace() & Decl::IDNS_Ordinary))
10240 assert(IsInstantiation && "no scope in non-instantiation");
10241 if (CurContext->isRecord())
10242 LookupQualifiedName(Previous, CurContext);
10244 // No redeclaration check is needed here; in non-member contexts we
10245 // diagnosed all possible conflicts with other using-declarations when
10246 // building the template:
10248 // For a dependent non-type using declaration, the only valid case is
10249 // if we instantiate to a single enumerator. We check for conflicts
10250 // between shadow declarations we introduce, and we check in the template
10251 // definition for conflicts between a non-type using declaration and any
10252 // other declaration, which together covers all cases.
10254 // A dependent typename using declaration will never successfully
10255 // instantiate, since it will always name a class member, so we reject
10256 // that in the template definition.
10260 // Check for invalid redeclarations.
10261 if (CheckUsingDeclRedeclaration(UsingLoc, HasTypenameKeyword,
10262 SS, IdentLoc, Previous))
10265 // Check for bad qualifiers.
10266 if (CheckUsingDeclQualifier(UsingLoc, HasTypenameKeyword, SS, NameInfo,
10270 DeclContext *LookupContext = computeDeclContext(SS);
10272 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
10273 if (!LookupContext || EllipsisLoc.isValid()) {
10274 if (HasTypenameKeyword) {
10275 // FIXME: not all declaration name kinds are legal here
10276 D = UnresolvedUsingTypenameDecl::Create(Context, CurContext,
10277 UsingLoc, TypenameLoc,
10279 IdentLoc, NameInfo.getName(),
10282 D = UnresolvedUsingValueDecl::Create(Context, CurContext, UsingLoc,
10283 QualifierLoc, NameInfo, EllipsisLoc);
10286 CurContext->addDecl(D);
10290 auto Build = [&](bool Invalid) {
10292 UsingDecl::Create(Context, CurContext, UsingLoc, QualifierLoc,
10293 UsingName, HasTypenameKeyword);
10295 CurContext->addDecl(UD);
10296 UD->setInvalidDecl(Invalid);
10299 auto BuildInvalid = [&]{ return Build(true); };
10300 auto BuildValid = [&]{ return Build(false); };
10302 if (RequireCompleteDeclContext(SS, LookupContext))
10303 return BuildInvalid();
10305 // Look up the target name.
10306 LookupResult R(*this, NameInfo, LookupOrdinaryName);
10308 // Unlike most lookups, we don't always want to hide tag
10309 // declarations: tag names are visible through the using declaration
10310 // even if hidden by ordinary names, *except* in a dependent context
10311 // where it's important for the sanity of two-phase lookup.
10312 if (!IsInstantiation)
10313 R.setHideTags(false);
10315 // For the purposes of this lookup, we have a base object type
10316 // equal to that of the current context.
10317 if (CurContext->isRecord()) {
10318 R.setBaseObjectType(
10319 Context.getTypeDeclType(cast<CXXRecordDecl>(CurContext)));
10322 LookupQualifiedName(R, LookupContext);
10324 // Try to correct typos if possible. If constructor name lookup finds no
10325 // results, that means the named class has no explicit constructors, and we
10326 // suppressed declaring implicit ones (probably because it's dependent or
10329 NameInfo.getName().getNameKind() != DeclarationName::CXXConstructorName) {
10330 // HACK: Work around a bug in libstdc++'s detection of ::gets. Sometimes
10331 // it will believe that glibc provides a ::gets in cases where it does not,
10332 // and will try to pull it into namespace std with a using-declaration.
10333 // Just ignore the using-declaration in that case.
10334 auto *II = NameInfo.getName().getAsIdentifierInfo();
10335 if (getLangOpts().CPlusPlus14 && II && II->isStr("gets") &&
10336 CurContext->isStdNamespace() &&
10337 isa<TranslationUnitDecl>(LookupContext) &&
10338 getSourceManager().isInSystemHeader(UsingLoc))
10340 UsingValidatorCCC CCC(HasTypenameKeyword, IsInstantiation, SS.getScopeRep(),
10341 dyn_cast<CXXRecordDecl>(CurContext));
10342 if (TypoCorrection Corrected =
10343 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, &SS, CCC,
10344 CTK_ErrorRecovery)) {
10345 // We reject candidates where DroppedSpecifier == true, hence the
10346 // literal '0' below.
10347 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
10348 << NameInfo.getName() << LookupContext << 0
10351 // If we picked a correction with no attached Decl we can't do anything
10352 // useful with it, bail out.
10353 NamedDecl *ND = Corrected.getCorrectionDecl();
10355 return BuildInvalid();
10357 // If we corrected to an inheriting constructor, handle it as one.
10358 auto *RD = dyn_cast<CXXRecordDecl>(ND);
10359 if (RD && RD->isInjectedClassName()) {
10360 // The parent of the injected class name is the class itself.
10361 RD = cast<CXXRecordDecl>(RD->getParent());
10363 // Fix up the information we'll use to build the using declaration.
10364 if (Corrected.WillReplaceSpecifier()) {
10365 NestedNameSpecifierLocBuilder Builder;
10366 Builder.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
10367 QualifierLoc.getSourceRange());
10368 QualifierLoc = Builder.getWithLocInContext(Context);
10371 // In this case, the name we introduce is the name of a derived class
10373 auto *CurClass = cast<CXXRecordDecl>(CurContext);
10374 UsingName.setName(Context.DeclarationNames.getCXXConstructorName(
10375 Context.getCanonicalType(Context.getRecordType(CurClass))));
10376 UsingName.setNamedTypeInfo(nullptr);
10377 for (auto *Ctor : LookupConstructors(RD))
10381 // FIXME: Pick up all the declarations if we found an overloaded
10383 UsingName.setName(ND->getDeclName());
10387 Diag(IdentLoc, diag::err_no_member)
10388 << NameInfo.getName() << LookupContext << SS.getRange();
10389 return BuildInvalid();
10393 if (R.isAmbiguous())
10394 return BuildInvalid();
10396 if (HasTypenameKeyword) {
10397 // If we asked for a typename and got a non-type decl, error out.
10398 if (!R.getAsSingle<TypeDecl>()) {
10399 Diag(IdentLoc, diag::err_using_typename_non_type);
10400 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I)
10401 Diag((*I)->getUnderlyingDecl()->getLocation(),
10402 diag::note_using_decl_target);
10403 return BuildInvalid();
10406 // If we asked for a non-typename and we got a type, error out,
10407 // but only if this is an instantiation of an unresolved using
10408 // decl. Otherwise just silently find the type name.
10409 if (IsInstantiation && R.getAsSingle<TypeDecl>()) {
10410 Diag(IdentLoc, diag::err_using_dependent_value_is_type);
10411 Diag(R.getFoundDecl()->getLocation(), diag::note_using_decl_target);
10412 return BuildInvalid();
10416 // C++14 [namespace.udecl]p6:
10417 // A using-declaration shall not name a namespace.
10418 if (R.getAsSingle<NamespaceDecl>()) {
10419 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_namespace)
10421 return BuildInvalid();
10424 // C++14 [namespace.udecl]p7:
10425 // A using-declaration shall not name a scoped enumerator.
10426 if (auto *ED = R.getAsSingle<EnumConstantDecl>()) {
10427 if (cast<EnumDecl>(ED->getDeclContext())->isScoped()) {
10428 Diag(IdentLoc, diag::err_using_decl_can_not_refer_to_scoped_enum)
10430 return BuildInvalid();
10434 UsingDecl *UD = BuildValid();
10436 // Some additional rules apply to inheriting constructors.
10437 if (UsingName.getName().getNameKind() ==
10438 DeclarationName::CXXConstructorName) {
10439 // Suppress access diagnostics; the access check is instead performed at the
10440 // point of use for an inheriting constructor.
10441 R.suppressDiagnostics();
10442 if (CheckInheritingConstructorUsingDecl(UD))
10446 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) {
10447 UsingShadowDecl *PrevDecl = nullptr;
10448 if (!CheckUsingShadowDecl(UD, *I, Previous, PrevDecl))
10449 BuildUsingShadowDecl(S, UD, *I, PrevDecl);
10455 NamedDecl *Sema::BuildUsingPackDecl(NamedDecl *InstantiatedFrom,
10456 ArrayRef<NamedDecl *> Expansions) {
10457 assert(isa<UnresolvedUsingValueDecl>(InstantiatedFrom) ||
10458 isa<UnresolvedUsingTypenameDecl>(InstantiatedFrom) ||
10459 isa<UsingPackDecl>(InstantiatedFrom));
10462 UsingPackDecl::Create(Context, CurContext, InstantiatedFrom, Expansions);
10463 UPD->setAccess(InstantiatedFrom->getAccess());
10464 CurContext->addDecl(UPD);
10468 /// Additional checks for a using declaration referring to a constructor name.
10469 bool Sema::CheckInheritingConstructorUsingDecl(UsingDecl *UD) {
10470 assert(!UD->hasTypename() && "expecting a constructor name");
10472 const Type *SourceType = UD->getQualifier()->getAsType();
10473 assert(SourceType &&
10474 "Using decl naming constructor doesn't have type in scope spec.");
10475 CXXRecordDecl *TargetClass = cast<CXXRecordDecl>(CurContext);
10477 // Check whether the named type is a direct base class.
10478 bool AnyDependentBases = false;
10479 auto *Base = findDirectBaseWithType(TargetClass, QualType(SourceType, 0),
10480 AnyDependentBases);
10481 if (!Base && !AnyDependentBases) {
10482 Diag(UD->getUsingLoc(),
10483 diag::err_using_decl_constructor_not_in_direct_base)
10484 << UD->getNameInfo().getSourceRange()
10485 << QualType(SourceType, 0) << TargetClass;
10486 UD->setInvalidDecl();
10491 Base->setInheritConstructors();
10496 /// Checks that the given using declaration is not an invalid
10497 /// redeclaration. Note that this is checking only for the using decl
10498 /// itself, not for any ill-formedness among the UsingShadowDecls.
10499 bool Sema::CheckUsingDeclRedeclaration(SourceLocation UsingLoc,
10500 bool HasTypenameKeyword,
10501 const CXXScopeSpec &SS,
10502 SourceLocation NameLoc,
10503 const LookupResult &Prev) {
10504 NestedNameSpecifier *Qual = SS.getScopeRep();
10506 // C++03 [namespace.udecl]p8:
10507 // C++0x [namespace.udecl]p10:
10508 // A using-declaration is a declaration and can therefore be used
10509 // repeatedly where (and only where) multiple declarations are
10512 // That's in non-member contexts.
10513 if (!CurContext->getRedeclContext()->isRecord()) {
10514 // A dependent qualifier outside a class can only ever resolve to an
10515 // enumeration type. Therefore it conflicts with any other non-type
10516 // declaration in the same scope.
10517 // FIXME: How should we check for dependent type-type conflicts at block
10519 if (Qual->isDependent() && !HasTypenameKeyword) {
10520 for (auto *D : Prev) {
10521 if (!isa<TypeDecl>(D) && !isa<UsingDecl>(D) && !isa<UsingPackDecl>(D)) {
10522 bool OldCouldBeEnumerator =
10523 isa<UnresolvedUsingValueDecl>(D) || isa<EnumConstantDecl>(D);
10525 OldCouldBeEnumerator ? diag::err_redefinition
10526 : diag::err_redefinition_different_kind)
10527 << Prev.getLookupName();
10528 Diag(D->getLocation(), diag::note_previous_definition);
10536 for (LookupResult::iterator I = Prev.begin(), E = Prev.end(); I != E; ++I) {
10540 NestedNameSpecifier *DQual;
10541 if (UsingDecl *UD = dyn_cast<UsingDecl>(D)) {
10542 DTypename = UD->hasTypename();
10543 DQual = UD->getQualifier();
10544 } else if (UnresolvedUsingValueDecl *UD
10545 = dyn_cast<UnresolvedUsingValueDecl>(D)) {
10547 DQual = UD->getQualifier();
10548 } else if (UnresolvedUsingTypenameDecl *UD
10549 = dyn_cast<UnresolvedUsingTypenameDecl>(D)) {
10551 DQual = UD->getQualifier();
10554 // using decls differ if one says 'typename' and the other doesn't.
10555 // FIXME: non-dependent using decls?
10556 if (HasTypenameKeyword != DTypename) continue;
10558 // using decls differ if they name different scopes (but note that
10559 // template instantiation can cause this check to trigger when it
10560 // didn't before instantiation).
10561 if (Context.getCanonicalNestedNameSpecifier(Qual) !=
10562 Context.getCanonicalNestedNameSpecifier(DQual))
10565 Diag(NameLoc, diag::err_using_decl_redeclaration) << SS.getRange();
10566 Diag(D->getLocation(), diag::note_using_decl) << 1;
10574 /// Checks that the given nested-name qualifier used in a using decl
10575 /// in the current context is appropriately related to the current
10576 /// scope. If an error is found, diagnoses it and returns true.
10577 bool Sema::CheckUsingDeclQualifier(SourceLocation UsingLoc,
10579 const CXXScopeSpec &SS,
10580 const DeclarationNameInfo &NameInfo,
10581 SourceLocation NameLoc) {
10582 DeclContext *NamedContext = computeDeclContext(SS);
10584 if (!CurContext->isRecord()) {
10585 // C++03 [namespace.udecl]p3:
10586 // C++0x [namespace.udecl]p8:
10587 // A using-declaration for a class member shall be a member-declaration.
10589 // If we weren't able to compute a valid scope, it might validly be a
10590 // dependent class scope or a dependent enumeration unscoped scope. If
10591 // we have a 'typename' keyword, the scope must resolve to a class type.
10592 if ((HasTypename && !NamedContext) ||
10593 (NamedContext && NamedContext->getRedeclContext()->isRecord())) {
10594 auto *RD = NamedContext
10595 ? cast<CXXRecordDecl>(NamedContext->getRedeclContext())
10597 if (RD && RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), RD))
10600 Diag(NameLoc, diag::err_using_decl_can_not_refer_to_class_member)
10603 // If we have a complete, non-dependent source type, try to suggest a
10604 // way to get the same effect.
10608 // Find what this using-declaration was referring to.
10609 LookupResult R(*this, NameInfo, LookupOrdinaryName);
10610 R.setHideTags(false);
10611 R.suppressDiagnostics();
10612 LookupQualifiedName(R, RD);
10614 if (R.getAsSingle<TypeDecl>()) {
10615 if (getLangOpts().CPlusPlus11) {
10616 // Convert 'using X::Y;' to 'using Y = X::Y;'.
10617 Diag(SS.getBeginLoc(), diag::note_using_decl_class_member_workaround)
10618 << 0 // alias declaration
10619 << FixItHint::CreateInsertion(SS.getBeginLoc(),
10620 NameInfo.getName().getAsString() +
10623 // Convert 'using X::Y;' to 'typedef X::Y Y;'.
10624 SourceLocation InsertLoc = getLocForEndOfToken(NameInfo.getEndLoc());
10625 Diag(InsertLoc, diag::note_using_decl_class_member_workaround)
10626 << 1 // typedef declaration
10627 << FixItHint::CreateReplacement(UsingLoc, "typedef")
10628 << FixItHint::CreateInsertion(
10629 InsertLoc, " " + NameInfo.getName().getAsString());
10631 } else if (R.getAsSingle<VarDecl>()) {
10632 // Don't provide a fixit outside C++11 mode; we don't want to suggest
10633 // repeating the type of the static data member here.
10635 if (getLangOpts().CPlusPlus11) {
10636 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
10637 FixIt = FixItHint::CreateReplacement(
10638 UsingLoc, "auto &" + NameInfo.getName().getAsString() + " = ");
10641 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
10642 << 2 // reference declaration
10644 } else if (R.getAsSingle<EnumConstantDecl>()) {
10645 // Don't provide a fixit outside C++11 mode; we don't want to suggest
10646 // repeating the type of the enumeration here, and we can't do so if
10647 // the type is anonymous.
10649 if (getLangOpts().CPlusPlus11) {
10650 // Convert 'using X::Y;' to 'auto &Y = X::Y;'.
10651 FixIt = FixItHint::CreateReplacement(
10653 "constexpr auto " + NameInfo.getName().getAsString() + " = ");
10656 Diag(UsingLoc, diag::note_using_decl_class_member_workaround)
10657 << (getLangOpts().CPlusPlus11 ? 4 : 3) // const[expr] variable
10663 // Otherwise, this might be valid.
10667 // The current scope is a record.
10669 // If the named context is dependent, we can't decide much.
10670 if (!NamedContext) {
10671 // FIXME: in C++0x, we can diagnose if we can prove that the
10672 // nested-name-specifier does not refer to a base class, which is
10673 // still possible in some cases.
10675 // Otherwise we have to conservatively report that things might be
10680 if (!NamedContext->isRecord()) {
10681 // Ideally this would point at the last name in the specifier,
10682 // but we don't have that level of source info.
10683 Diag(SS.getRange().getBegin(),
10684 diag::err_using_decl_nested_name_specifier_is_not_class)
10685 << SS.getScopeRep() << SS.getRange();
10689 if (!NamedContext->isDependentContext() &&
10690 RequireCompleteDeclContext(const_cast<CXXScopeSpec&>(SS), NamedContext))
10693 if (getLangOpts().CPlusPlus11) {
10694 // C++11 [namespace.udecl]p3:
10695 // In a using-declaration used as a member-declaration, the
10696 // nested-name-specifier shall name a base class of the class
10699 if (cast<CXXRecordDecl>(CurContext)->isProvablyNotDerivedFrom(
10700 cast<CXXRecordDecl>(NamedContext))) {
10701 if (CurContext == NamedContext) {
10703 diag::err_using_decl_nested_name_specifier_is_current_class)
10708 if (!cast<CXXRecordDecl>(NamedContext)->isInvalidDecl()) {
10709 Diag(SS.getRange().getBegin(),
10710 diag::err_using_decl_nested_name_specifier_is_not_base_class)
10711 << SS.getScopeRep()
10712 << cast<CXXRecordDecl>(CurContext)
10721 // C++03 [namespace.udecl]p4:
10722 // A using-declaration used as a member-declaration shall refer
10723 // to a member of a base class of the class being defined [etc.].
10725 // Salient point: SS doesn't have to name a base class as long as
10726 // lookup only finds members from base classes. Therefore we can
10727 // diagnose here only if we can prove that that can't happen,
10728 // i.e. if the class hierarchies provably don't intersect.
10730 // TODO: it would be nice if "definitely valid" results were cached
10731 // in the UsingDecl and UsingShadowDecl so that these checks didn't
10732 // need to be repeated.
10734 llvm::SmallPtrSet<const CXXRecordDecl *, 4> Bases;
10735 auto Collect = [&Bases](const CXXRecordDecl *Base) {
10736 Bases.insert(Base);
10740 // Collect all bases. Return false if we find a dependent base.
10741 if (!cast<CXXRecordDecl>(CurContext)->forallBases(Collect))
10744 // Returns true if the base is dependent or is one of the accumulated base
10746 auto IsNotBase = [&Bases](const CXXRecordDecl *Base) {
10747 return !Bases.count(Base);
10750 // Return false if the class has a dependent base or if it or one
10751 // of its bases is present in the base set of the current context.
10752 if (Bases.count(cast<CXXRecordDecl>(NamedContext)) ||
10753 !cast<CXXRecordDecl>(NamedContext)->forallBases(IsNotBase))
10756 Diag(SS.getRange().getBegin(),
10757 diag::err_using_decl_nested_name_specifier_is_not_base_class)
10758 << SS.getScopeRep()
10759 << cast<CXXRecordDecl>(CurContext)
10765 Decl *Sema::ActOnAliasDeclaration(Scope *S, AccessSpecifier AS,
10766 MultiTemplateParamsArg TemplateParamLists,
10767 SourceLocation UsingLoc, UnqualifiedId &Name,
10768 const ParsedAttributesView &AttrList,
10769 TypeResult Type, Decl *DeclFromDeclSpec) {
10770 // Skip up to the relevant declaration scope.
10771 while (S->isTemplateParamScope())
10772 S = S->getParent();
10773 assert((S->getFlags() & Scope::DeclScope) &&
10774 "got alias-declaration outside of declaration scope");
10776 if (Type.isInvalid())
10779 bool Invalid = false;
10780 DeclarationNameInfo NameInfo = GetNameFromUnqualifiedId(Name);
10781 TypeSourceInfo *TInfo = nullptr;
10782 GetTypeFromParser(Type.get(), &TInfo);
10784 if (DiagnoseClassNameShadow(CurContext, NameInfo))
10787 if (DiagnoseUnexpandedParameterPack(Name.StartLocation, TInfo,
10788 UPPC_DeclarationType)) {
10790 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
10791 TInfo->getTypeLoc().getBeginLoc());
10794 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
10795 TemplateParamLists.size()
10796 ? forRedeclarationInCurContext()
10797 : ForVisibleRedeclaration);
10798 LookupName(Previous, S);
10800 // Warn about shadowing the name of a template parameter.
10801 if (Previous.isSingleResult() &&
10802 Previous.getFoundDecl()->isTemplateParameter()) {
10803 DiagnoseTemplateParameterShadow(Name.StartLocation,Previous.getFoundDecl());
10807 assert(Name.Kind == UnqualifiedIdKind::IK_Identifier &&
10808 "name in alias declaration must be an identifier");
10809 TypeAliasDecl *NewTD = TypeAliasDecl::Create(Context, CurContext, UsingLoc,
10810 Name.StartLocation,
10811 Name.Identifier, TInfo);
10813 NewTD->setAccess(AS);
10816 NewTD->setInvalidDecl();
10818 ProcessDeclAttributeList(S, NewTD, AttrList);
10819 AddPragmaAttributes(S, NewTD);
10821 CheckTypedefForVariablyModifiedType(S, NewTD);
10822 Invalid |= NewTD->isInvalidDecl();
10824 bool Redeclaration = false;
10827 if (TemplateParamLists.size()) {
10828 TypeAliasTemplateDecl *OldDecl = nullptr;
10829 TemplateParameterList *OldTemplateParams = nullptr;
10831 if (TemplateParamLists.size() != 1) {
10832 Diag(UsingLoc, diag::err_alias_template_extra_headers)
10833 << SourceRange(TemplateParamLists[1]->getTemplateLoc(),
10834 TemplateParamLists[TemplateParamLists.size()-1]->getRAngleLoc());
10836 TemplateParameterList *TemplateParams = TemplateParamLists[0];
10838 // Check that we can declare a template here.
10839 if (CheckTemplateDeclScope(S, TemplateParams))
10842 // Only consider previous declarations in the same scope.
10843 FilterLookupForScope(Previous, CurContext, S, /*ConsiderLinkage*/false,
10844 /*ExplicitInstantiationOrSpecialization*/false);
10845 if (!Previous.empty()) {
10846 Redeclaration = true;
10848 OldDecl = Previous.getAsSingle<TypeAliasTemplateDecl>();
10849 if (!OldDecl && !Invalid) {
10850 Diag(UsingLoc, diag::err_redefinition_different_kind)
10851 << Name.Identifier;
10853 NamedDecl *OldD = Previous.getRepresentativeDecl();
10854 if (OldD->getLocation().isValid())
10855 Diag(OldD->getLocation(), diag::note_previous_definition);
10860 if (!Invalid && OldDecl && !OldDecl->isInvalidDecl()) {
10861 if (TemplateParameterListsAreEqual(TemplateParams,
10862 OldDecl->getTemplateParameters(),
10864 TPL_TemplateMatch))
10865 OldTemplateParams =
10866 OldDecl->getMostRecentDecl()->getTemplateParameters();
10870 TypeAliasDecl *OldTD = OldDecl->getTemplatedDecl();
10872 !Context.hasSameType(OldTD->getUnderlyingType(),
10873 NewTD->getUnderlyingType())) {
10874 // FIXME: The C++0x standard does not clearly say this is ill-formed,
10875 // but we can't reasonably accept it.
10876 Diag(NewTD->getLocation(), diag::err_redefinition_different_typedef)
10877 << 2 << NewTD->getUnderlyingType() << OldTD->getUnderlyingType();
10878 if (OldTD->getLocation().isValid())
10879 Diag(OldTD->getLocation(), diag::note_previous_definition);
10885 // Merge any previous default template arguments into our parameters,
10886 // and check the parameter list.
10887 if (CheckTemplateParameterList(TemplateParams, OldTemplateParams,
10888 TPC_TypeAliasTemplate))
10891 TypeAliasTemplateDecl *NewDecl =
10892 TypeAliasTemplateDecl::Create(Context, CurContext, UsingLoc,
10893 Name.Identifier, TemplateParams,
10895 NewTD->setDescribedAliasTemplate(NewDecl);
10897 NewDecl->setAccess(AS);
10900 NewDecl->setInvalidDecl();
10901 else if (OldDecl) {
10902 NewDecl->setPreviousDecl(OldDecl);
10903 CheckRedeclarationModuleOwnership(NewDecl, OldDecl);
10908 if (auto *TD = dyn_cast_or_null<TagDecl>(DeclFromDeclSpec)) {
10909 setTagNameForLinkagePurposes(TD, NewTD);
10910 handleTagNumbering(TD, S);
10912 ActOnTypedefNameDecl(S, CurContext, NewTD, Previous, Redeclaration);
10916 PushOnScopeChains(NewND, S);
10917 ActOnDocumentableDecl(NewND);
10921 Decl *Sema::ActOnNamespaceAliasDef(Scope *S, SourceLocation NamespaceLoc,
10922 SourceLocation AliasLoc,
10923 IdentifierInfo *Alias, CXXScopeSpec &SS,
10924 SourceLocation IdentLoc,
10925 IdentifierInfo *Ident) {
10927 // Lookup the namespace name.
10928 LookupResult R(*this, Ident, IdentLoc, LookupNamespaceName);
10929 LookupParsedName(R, S, &SS);
10931 if (R.isAmbiguous())
10935 if (!TryNamespaceTypoCorrection(*this, R, S, SS, IdentLoc, Ident)) {
10936 Diag(IdentLoc, diag::err_expected_namespace_name) << SS.getRange();
10940 assert(!R.isAmbiguous() && !R.empty());
10941 NamedDecl *ND = R.getRepresentativeDecl();
10943 // Check if we have a previous declaration with the same name.
10944 LookupResult PrevR(*this, Alias, AliasLoc, LookupOrdinaryName,
10945 ForVisibleRedeclaration);
10946 LookupName(PrevR, S);
10948 // Check we're not shadowing a template parameter.
10949 if (PrevR.isSingleResult() && PrevR.getFoundDecl()->isTemplateParameter()) {
10950 DiagnoseTemplateParameterShadow(AliasLoc, PrevR.getFoundDecl());
10954 // Filter out any other lookup result from an enclosing scope.
10955 FilterLookupForScope(PrevR, CurContext, S, /*ConsiderLinkage*/false,
10956 /*AllowInlineNamespace*/false);
10958 // Find the previous declaration and check that we can redeclare it.
10959 NamespaceAliasDecl *Prev = nullptr;
10960 if (PrevR.isSingleResult()) {
10961 NamedDecl *PrevDecl = PrevR.getRepresentativeDecl();
10962 if (NamespaceAliasDecl *AD = dyn_cast<NamespaceAliasDecl>(PrevDecl)) {
10963 // We already have an alias with the same name that points to the same
10964 // namespace; check that it matches.
10965 if (AD->getNamespace()->Equals(getNamespaceDecl(ND))) {
10967 } else if (isVisible(PrevDecl)) {
10968 Diag(AliasLoc, diag::err_redefinition_different_namespace_alias)
10970 Diag(AD->getLocation(), diag::note_previous_namespace_alias)
10971 << AD->getNamespace();
10974 } else if (isVisible(PrevDecl)) {
10975 unsigned DiagID = isa<NamespaceDecl>(PrevDecl->getUnderlyingDecl())
10976 ? diag::err_redefinition
10977 : diag::err_redefinition_different_kind;
10978 Diag(AliasLoc, DiagID) << Alias;
10979 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
10984 // The use of a nested name specifier may trigger deprecation warnings.
10985 DiagnoseUseOfDecl(ND, IdentLoc);
10987 NamespaceAliasDecl *AliasDecl =
10988 NamespaceAliasDecl::Create(Context, CurContext, NamespaceLoc, AliasLoc,
10989 Alias, SS.getWithLocInContext(Context),
10992 AliasDecl->setPreviousDecl(Prev);
10994 PushOnScopeChains(AliasDecl, S);
10999 struct SpecialMemberExceptionSpecInfo
11000 : SpecialMemberVisitor<SpecialMemberExceptionSpecInfo> {
11001 SourceLocation Loc;
11002 Sema::ImplicitExceptionSpecification ExceptSpec;
11004 SpecialMemberExceptionSpecInfo(Sema &S, CXXMethodDecl *MD,
11005 Sema::CXXSpecialMember CSM,
11006 Sema::InheritedConstructorInfo *ICI,
11007 SourceLocation Loc)
11008 : SpecialMemberVisitor(S, MD, CSM, ICI), Loc(Loc), ExceptSpec(S) {}
11010 bool visitBase(CXXBaseSpecifier *Base);
11011 bool visitField(FieldDecl *FD);
11013 void visitClassSubobject(CXXRecordDecl *Class, Subobject Subobj,
11016 void visitSubobjectCall(Subobject Subobj,
11017 Sema::SpecialMemberOverloadResult SMOR);
11021 bool SpecialMemberExceptionSpecInfo::visitBase(CXXBaseSpecifier *Base) {
11022 auto *RT = Base->getType()->getAs<RecordType>();
11026 auto *BaseClass = cast<CXXRecordDecl>(RT->getDecl());
11027 Sema::SpecialMemberOverloadResult SMOR = lookupInheritedCtor(BaseClass);
11028 if (auto *BaseCtor = SMOR.getMethod()) {
11029 visitSubobjectCall(Base, BaseCtor);
11033 visitClassSubobject(BaseClass, Base, 0);
11037 bool SpecialMemberExceptionSpecInfo::visitField(FieldDecl *FD) {
11038 if (CSM == Sema::CXXDefaultConstructor && FD->hasInClassInitializer()) {
11039 Expr *E = FD->getInClassInitializer();
11041 // FIXME: It's a little wasteful to build and throw away a
11042 // CXXDefaultInitExpr here.
11043 // FIXME: We should have a single context note pointing at Loc, and
11044 // this location should be MD->getLocation() instead, since that's
11045 // the location where we actually use the default init expression.
11046 E = S.BuildCXXDefaultInitExpr(Loc, FD).get();
11048 ExceptSpec.CalledExpr(E);
11049 } else if (auto *RT = S.Context.getBaseElementType(FD->getType())
11050 ->getAs<RecordType>()) {
11051 visitClassSubobject(cast<CXXRecordDecl>(RT->getDecl()), FD,
11052 FD->getType().getCVRQualifiers());
11057 void SpecialMemberExceptionSpecInfo::visitClassSubobject(CXXRecordDecl *Class,
11060 FieldDecl *Field = Subobj.dyn_cast<FieldDecl*>();
11061 bool IsMutable = Field && Field->isMutable();
11062 visitSubobjectCall(Subobj, lookupIn(Class, Quals, IsMutable));
11065 void SpecialMemberExceptionSpecInfo::visitSubobjectCall(
11066 Subobject Subobj, Sema::SpecialMemberOverloadResult SMOR) {
11067 // Note, if lookup fails, it doesn't matter what exception specification we
11068 // choose because the special member will be deleted.
11069 if (CXXMethodDecl *MD = SMOR.getMethod())
11070 ExceptSpec.CalledDecl(getSubobjectLoc(Subobj), MD);
11074 /// RAII object to register a special member as being currently declared.
11075 struct ComputingExceptionSpec {
11078 ComputingExceptionSpec(Sema &S, CXXMethodDecl *MD, SourceLocation Loc)
11080 Sema::CodeSynthesisContext Ctx;
11081 Ctx.Kind = Sema::CodeSynthesisContext::ExceptionSpecEvaluation;
11082 Ctx.PointOfInstantiation = Loc;
11084 S.pushCodeSynthesisContext(Ctx);
11086 ~ComputingExceptionSpec() {
11087 S.popCodeSynthesisContext();
11092 bool Sema::tryResolveExplicitSpecifier(ExplicitSpecifier &ExplicitSpec) {
11093 llvm::APSInt Result;
11094 ExprResult Converted = CheckConvertedConstantExpression(
11095 ExplicitSpec.getExpr(), Context.BoolTy, Result, CCEK_ExplicitBool);
11096 ExplicitSpec.setExpr(Converted.get());
11097 if (Converted.isUsable() && !Converted.get()->isValueDependent()) {
11098 ExplicitSpec.setKind(Result.getBoolValue()
11099 ? ExplicitSpecKind::ResolvedTrue
11100 : ExplicitSpecKind::ResolvedFalse);
11103 ExplicitSpec.setKind(ExplicitSpecKind::Unresolved);
11107 ExplicitSpecifier Sema::ActOnExplicitBoolSpecifier(Expr *ExplicitExpr) {
11108 ExplicitSpecifier ES(ExplicitExpr, ExplicitSpecKind::Unresolved);
11109 if (!ExplicitExpr->isTypeDependent())
11110 tryResolveExplicitSpecifier(ES);
11114 static Sema::ImplicitExceptionSpecification
11115 ComputeDefaultedSpecialMemberExceptionSpec(
11116 Sema &S, SourceLocation Loc, CXXMethodDecl *MD, Sema::CXXSpecialMember CSM,
11117 Sema::InheritedConstructorInfo *ICI) {
11118 ComputingExceptionSpec CES(S, MD, Loc);
11120 CXXRecordDecl *ClassDecl = MD->getParent();
11122 // C++ [except.spec]p14:
11123 // An implicitly declared special member function (Clause 12) shall have an
11124 // exception-specification. [...]
11125 SpecialMemberExceptionSpecInfo Info(S, MD, CSM, ICI, MD->getLocation());
11126 if (ClassDecl->isInvalidDecl())
11127 return Info.ExceptSpec;
11129 // FIXME: If this diagnostic fires, we're probably missing a check for
11130 // attempting to resolve an exception specification before it's known
11131 // at a higher level.
11132 if (S.RequireCompleteType(MD->getLocation(),
11133 S.Context.getRecordType(ClassDecl),
11134 diag::err_exception_spec_incomplete_type))
11135 return Info.ExceptSpec;
11137 // C++1z [except.spec]p7:
11138 // [Look for exceptions thrown by] a constructor selected [...] to
11139 // initialize a potentially constructed subobject,
11140 // C++1z [except.spec]p8:
11141 // The exception specification for an implicitly-declared destructor, or a
11142 // destructor without a noexcept-specifier, is potentially-throwing if and
11143 // only if any of the destructors for any of its potentially constructed
11144 // subojects is potentially throwing.
11145 // FIXME: We respect the first rule but ignore the "potentially constructed"
11146 // in the second rule to resolve a core issue (no number yet) that would have
11148 // struct A { virtual void f() = 0; virtual ~A() noexcept(false) = 0; };
11149 // struct B : A {};
11150 // struct C : B { void f(); };
11151 // ... due to giving B::~B() a non-throwing exception specification.
11152 Info.visit(Info.IsConstructor ? Info.VisitPotentiallyConstructedBases
11153 : Info.VisitAllBases);
11155 return Info.ExceptSpec;
11159 /// RAII object to register a special member as being currently declared.
11160 struct DeclaringSpecialMember {
11162 Sema::SpecialMemberDecl D;
11163 Sema::ContextRAII SavedContext;
11164 bool WasAlreadyBeingDeclared;
11166 DeclaringSpecialMember(Sema &S, CXXRecordDecl *RD, Sema::CXXSpecialMember CSM)
11167 : S(S), D(RD, CSM), SavedContext(S, RD) {
11168 WasAlreadyBeingDeclared = !S.SpecialMembersBeingDeclared.insert(D).second;
11169 if (WasAlreadyBeingDeclared)
11170 // This almost never happens, but if it does, ensure that our cache
11171 // doesn't contain a stale result.
11172 S.SpecialMemberCache.clear();
11174 // Register a note to be produced if we encounter an error while
11175 // declaring the special member.
11176 Sema::CodeSynthesisContext Ctx;
11177 Ctx.Kind = Sema::CodeSynthesisContext::DeclaringSpecialMember;
11178 // FIXME: We don't have a location to use here. Using the class's
11179 // location maintains the fiction that we declare all special members
11180 // with the class, but (1) it's not clear that lying about that helps our
11181 // users understand what's going on, and (2) there may be outer contexts
11182 // on the stack (some of which are relevant) and printing them exposes
11184 Ctx.PointOfInstantiation = RD->getLocation();
11186 Ctx.SpecialMember = CSM;
11187 S.pushCodeSynthesisContext(Ctx);
11190 ~DeclaringSpecialMember() {
11191 if (!WasAlreadyBeingDeclared) {
11192 S.SpecialMembersBeingDeclared.erase(D);
11193 S.popCodeSynthesisContext();
11197 /// Are we already trying to declare this special member?
11198 bool isAlreadyBeingDeclared() const {
11199 return WasAlreadyBeingDeclared;
11204 void Sema::CheckImplicitSpecialMemberDeclaration(Scope *S, FunctionDecl *FD) {
11205 // Look up any existing declarations, but don't trigger declaration of all
11206 // implicit special members with this name.
11207 DeclarationName Name = FD->getDeclName();
11208 LookupResult R(*this, Name, SourceLocation(), LookupOrdinaryName,
11209 ForExternalRedeclaration);
11210 for (auto *D : FD->getParent()->lookup(Name))
11211 if (auto *Acceptable = R.getAcceptableDecl(D))
11212 R.addDecl(Acceptable);
11214 R.suppressDiagnostics();
11216 CheckFunctionDeclaration(S, FD, R, /*IsMemberSpecialization*/false);
11219 void Sema::setupImplicitSpecialMemberType(CXXMethodDecl *SpecialMem,
11221 ArrayRef<QualType> Args) {
11222 // Build an exception specification pointing back at this constructor.
11223 FunctionProtoType::ExtProtoInfo EPI = getImplicitMethodEPI(*this, SpecialMem);
11225 if (getLangOpts().OpenCLCPlusPlus) {
11226 // OpenCL: Implicitly defaulted special member are of the generic address
11228 EPI.TypeQuals.addAddressSpace(LangAS::opencl_generic);
11231 auto QT = Context.getFunctionType(ResultTy, Args, EPI);
11232 SpecialMem->setType(QT);
11235 CXXConstructorDecl *Sema::DeclareImplicitDefaultConstructor(
11236 CXXRecordDecl *ClassDecl) {
11237 // C++ [class.ctor]p5:
11238 // A default constructor for a class X is a constructor of class X
11239 // that can be called without an argument. If there is no
11240 // user-declared constructor for class X, a default constructor is
11241 // implicitly declared. An implicitly-declared default constructor
11242 // is an inline public member of its class.
11243 assert(ClassDecl->needsImplicitDefaultConstructor() &&
11244 "Should not build implicit default constructor!");
11246 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDefaultConstructor);
11247 if (DSM.isAlreadyBeingDeclared())
11250 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
11251 CXXDefaultConstructor,
11254 // Create the actual constructor declaration.
11255 CanQualType ClassType
11256 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
11257 SourceLocation ClassLoc = ClassDecl->getLocation();
11258 DeclarationName Name
11259 = Context.DeclarationNames.getCXXConstructorName(ClassType);
11260 DeclarationNameInfo NameInfo(Name, ClassLoc);
11261 CXXConstructorDecl *DefaultCon = CXXConstructorDecl::Create(
11262 Context, ClassDecl, ClassLoc, NameInfo, /*Type*/ QualType(),
11263 /*TInfo=*/nullptr, ExplicitSpecifier(),
11264 /*isInline=*/true, /*isImplicitlyDeclared=*/true,
11265 Constexpr ? CSK_constexpr : CSK_unspecified);
11266 DefaultCon->setAccess(AS_public);
11267 DefaultCon->setDefaulted();
11269 if (getLangOpts().CUDA) {
11270 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDefaultConstructor,
11272 /* ConstRHS */ false,
11273 /* Diagnose */ false);
11276 setupImplicitSpecialMemberType(DefaultCon, Context.VoidTy, None);
11278 // We don't need to use SpecialMemberIsTrivial here; triviality for default
11279 // constructors is easy to compute.
11280 DefaultCon->setTrivial(ClassDecl->hasTrivialDefaultConstructor());
11282 // Note that we have declared this constructor.
11283 ++getASTContext().NumImplicitDefaultConstructorsDeclared;
11285 Scope *S = getScopeForContext(ClassDecl);
11286 CheckImplicitSpecialMemberDeclaration(S, DefaultCon);
11288 if (ShouldDeleteSpecialMember(DefaultCon, CXXDefaultConstructor))
11289 SetDeclDeleted(DefaultCon, ClassLoc);
11292 PushOnScopeChains(DefaultCon, S, false);
11293 ClassDecl->addDecl(DefaultCon);
11298 void Sema::DefineImplicitDefaultConstructor(SourceLocation CurrentLocation,
11299 CXXConstructorDecl *Constructor) {
11300 assert((Constructor->isDefaulted() && Constructor->isDefaultConstructor() &&
11301 !Constructor->doesThisDeclarationHaveABody() &&
11302 !Constructor->isDeleted()) &&
11303 "DefineImplicitDefaultConstructor - call it for implicit default ctor");
11304 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
11307 CXXRecordDecl *ClassDecl = Constructor->getParent();
11308 assert(ClassDecl && "DefineImplicitDefaultConstructor - invalid constructor");
11310 SynthesizedFunctionScope Scope(*this, Constructor);
11312 // The exception specification is needed because we are defining the
11314 ResolveExceptionSpec(CurrentLocation,
11315 Constructor->getType()->castAs<FunctionProtoType>());
11316 MarkVTableUsed(CurrentLocation, ClassDecl);
11318 // Add a context note for diagnostics produced after this point.
11319 Scope.addContextNote(CurrentLocation);
11321 if (SetCtorInitializers(Constructor, /*AnyErrors=*/false)) {
11322 Constructor->setInvalidDecl();
11326 SourceLocation Loc = Constructor->getEndLoc().isValid()
11327 ? Constructor->getEndLoc()
11328 : Constructor->getLocation();
11329 Constructor->setBody(new (Context) CompoundStmt(Loc));
11330 Constructor->markUsed(Context);
11332 if (ASTMutationListener *L = getASTMutationListener()) {
11333 L->CompletedImplicitDefinition(Constructor);
11336 DiagnoseUninitializedFields(*this, Constructor);
11339 void Sema::ActOnFinishDelayedMemberInitializers(Decl *D) {
11340 // Perform any delayed checks on exception specifications.
11341 CheckDelayedMemberExceptionSpecs();
11344 /// Find or create the fake constructor we synthesize to model constructing an
11345 /// object of a derived class via a constructor of a base class.
11346 CXXConstructorDecl *
11347 Sema::findInheritingConstructor(SourceLocation Loc,
11348 CXXConstructorDecl *BaseCtor,
11349 ConstructorUsingShadowDecl *Shadow) {
11350 CXXRecordDecl *Derived = Shadow->getParent();
11351 SourceLocation UsingLoc = Shadow->getLocation();
11353 // FIXME: Add a new kind of DeclarationName for an inherited constructor.
11354 // For now we use the name of the base class constructor as a member of the
11355 // derived class to indicate a (fake) inherited constructor name.
11356 DeclarationName Name = BaseCtor->getDeclName();
11358 // Check to see if we already have a fake constructor for this inherited
11359 // constructor call.
11360 for (NamedDecl *Ctor : Derived->lookup(Name))
11361 if (declaresSameEntity(cast<CXXConstructorDecl>(Ctor)
11362 ->getInheritedConstructor()
11365 return cast<CXXConstructorDecl>(Ctor);
11367 DeclarationNameInfo NameInfo(Name, UsingLoc);
11368 TypeSourceInfo *TInfo =
11369 Context.getTrivialTypeSourceInfo(BaseCtor->getType(), UsingLoc);
11370 FunctionProtoTypeLoc ProtoLoc =
11371 TInfo->getTypeLoc().IgnoreParens().castAs<FunctionProtoTypeLoc>();
11373 // Check the inherited constructor is valid and find the list of base classes
11374 // from which it was inherited.
11375 InheritedConstructorInfo ICI(*this, Loc, Shadow);
11378 BaseCtor->isConstexpr() &&
11379 defaultedSpecialMemberIsConstexpr(*this, Derived, CXXDefaultConstructor,
11380 false, BaseCtor, &ICI);
11382 CXXConstructorDecl *DerivedCtor = CXXConstructorDecl::Create(
11383 Context, Derived, UsingLoc, NameInfo, TInfo->getType(), TInfo,
11384 BaseCtor->getExplicitSpecifier(), /*isInline=*/true,
11385 /*isImplicitlyDeclared=*/true,
11386 Constexpr ? BaseCtor->getConstexprKind() : CSK_unspecified,
11387 InheritedConstructor(Shadow, BaseCtor));
11388 if (Shadow->isInvalidDecl())
11389 DerivedCtor->setInvalidDecl();
11391 // Build an unevaluated exception specification for this fake constructor.
11392 const FunctionProtoType *FPT = TInfo->getType()->castAs<FunctionProtoType>();
11393 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
11394 EPI.ExceptionSpec.Type = EST_Unevaluated;
11395 EPI.ExceptionSpec.SourceDecl = DerivedCtor;
11396 DerivedCtor->setType(Context.getFunctionType(FPT->getReturnType(),
11397 FPT->getParamTypes(), EPI));
11399 // Build the parameter declarations.
11400 SmallVector<ParmVarDecl *, 16> ParamDecls;
11401 for (unsigned I = 0, N = FPT->getNumParams(); I != N; ++I) {
11402 TypeSourceInfo *TInfo =
11403 Context.getTrivialTypeSourceInfo(FPT->getParamType(I), UsingLoc);
11404 ParmVarDecl *PD = ParmVarDecl::Create(
11405 Context, DerivedCtor, UsingLoc, UsingLoc, /*IdentifierInfo=*/nullptr,
11406 FPT->getParamType(I), TInfo, SC_None, /*DefArg=*/nullptr);
11407 PD->setScopeInfo(0, I);
11409 // Ensure attributes are propagated onto parameters (this matters for
11410 // format, pass_object_size, ...).
11411 mergeDeclAttributes(PD, BaseCtor->getParamDecl(I));
11412 ParamDecls.push_back(PD);
11413 ProtoLoc.setParam(I, PD);
11416 // Set up the new constructor.
11417 assert(!BaseCtor->isDeleted() && "should not use deleted constructor");
11418 DerivedCtor->setAccess(BaseCtor->getAccess());
11419 DerivedCtor->setParams(ParamDecls);
11420 Derived->addDecl(DerivedCtor);
11422 if (ShouldDeleteSpecialMember(DerivedCtor, CXXDefaultConstructor, &ICI))
11423 SetDeclDeleted(DerivedCtor, UsingLoc);
11425 return DerivedCtor;
11428 void Sema::NoteDeletedInheritingConstructor(CXXConstructorDecl *Ctor) {
11429 InheritedConstructorInfo ICI(*this, Ctor->getLocation(),
11430 Ctor->getInheritedConstructor().getShadowDecl());
11431 ShouldDeleteSpecialMember(Ctor, CXXDefaultConstructor, &ICI,
11435 void Sema::DefineInheritingConstructor(SourceLocation CurrentLocation,
11436 CXXConstructorDecl *Constructor) {
11437 CXXRecordDecl *ClassDecl = Constructor->getParent();
11438 assert(Constructor->getInheritedConstructor() &&
11439 !Constructor->doesThisDeclarationHaveABody() &&
11440 !Constructor->isDeleted());
11441 if (Constructor->willHaveBody() || Constructor->isInvalidDecl())
11444 // Initializations are performed "as if by a defaulted default constructor",
11445 // so enter the appropriate scope.
11446 SynthesizedFunctionScope Scope(*this, Constructor);
11448 // The exception specification is needed because we are defining the
11450 ResolveExceptionSpec(CurrentLocation,
11451 Constructor->getType()->castAs<FunctionProtoType>());
11452 MarkVTableUsed(CurrentLocation, ClassDecl);
11454 // Add a context note for diagnostics produced after this point.
11455 Scope.addContextNote(CurrentLocation);
11457 ConstructorUsingShadowDecl *Shadow =
11458 Constructor->getInheritedConstructor().getShadowDecl();
11459 CXXConstructorDecl *InheritedCtor =
11460 Constructor->getInheritedConstructor().getConstructor();
11462 // [class.inhctor.init]p1:
11463 // initialization proceeds as if a defaulted default constructor is used to
11464 // initialize the D object and each base class subobject from which the
11465 // constructor was inherited
11467 InheritedConstructorInfo ICI(*this, CurrentLocation, Shadow);
11468 CXXRecordDecl *RD = Shadow->getParent();
11469 SourceLocation InitLoc = Shadow->getLocation();
11471 // Build explicit initializers for all base classes from which the
11472 // constructor was inherited.
11473 SmallVector<CXXCtorInitializer*, 8> Inits;
11474 for (bool VBase : {false, true}) {
11475 for (CXXBaseSpecifier &B : VBase ? RD->vbases() : RD->bases()) {
11476 if (B.isVirtual() != VBase)
11479 auto *BaseRD = B.getType()->getAsCXXRecordDecl();
11483 auto BaseCtor = ICI.findConstructorForBase(BaseRD, InheritedCtor);
11484 if (!BaseCtor.first)
11487 MarkFunctionReferenced(CurrentLocation, BaseCtor.first);
11488 ExprResult Init = new (Context) CXXInheritedCtorInitExpr(
11489 InitLoc, B.getType(), BaseCtor.first, VBase, BaseCtor.second);
11491 auto *TInfo = Context.getTrivialTypeSourceInfo(B.getType(), InitLoc);
11492 Inits.push_back(new (Context) CXXCtorInitializer(
11493 Context, TInfo, VBase, InitLoc, Init.get(), InitLoc,
11494 SourceLocation()));
11498 // We now proceed as if for a defaulted default constructor, with the relevant
11499 // initializers replaced.
11501 if (SetCtorInitializers(Constructor, /*AnyErrors*/false, Inits)) {
11502 Constructor->setInvalidDecl();
11506 Constructor->setBody(new (Context) CompoundStmt(InitLoc));
11507 Constructor->markUsed(Context);
11509 if (ASTMutationListener *L = getASTMutationListener()) {
11510 L->CompletedImplicitDefinition(Constructor);
11513 DiagnoseUninitializedFields(*this, Constructor);
11516 CXXDestructorDecl *Sema::DeclareImplicitDestructor(CXXRecordDecl *ClassDecl) {
11517 // C++ [class.dtor]p2:
11518 // If a class has no user-declared destructor, a destructor is
11519 // declared implicitly. An implicitly-declared destructor is an
11520 // inline public member of its class.
11521 assert(ClassDecl->needsImplicitDestructor());
11523 DeclaringSpecialMember DSM(*this, ClassDecl, CXXDestructor);
11524 if (DSM.isAlreadyBeingDeclared())
11527 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
11531 // Create the actual destructor declaration.
11532 CanQualType ClassType
11533 = Context.getCanonicalType(Context.getTypeDeclType(ClassDecl));
11534 SourceLocation ClassLoc = ClassDecl->getLocation();
11535 DeclarationName Name
11536 = Context.DeclarationNames.getCXXDestructorName(ClassType);
11537 DeclarationNameInfo NameInfo(Name, ClassLoc);
11538 CXXDestructorDecl *Destructor =
11539 CXXDestructorDecl::Create(Context, ClassDecl, ClassLoc, NameInfo,
11540 QualType(), nullptr, /*isInline=*/true,
11541 /*isImplicitlyDeclared=*/true,
11542 Constexpr ? CSK_constexpr : CSK_unspecified);
11543 Destructor->setAccess(AS_public);
11544 Destructor->setDefaulted();
11546 if (getLangOpts().CUDA) {
11547 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXDestructor,
11549 /* ConstRHS */ false,
11550 /* Diagnose */ false);
11553 setupImplicitSpecialMemberType(Destructor, Context.VoidTy, None);
11555 // We don't need to use SpecialMemberIsTrivial here; triviality for
11556 // destructors is easy to compute.
11557 Destructor->setTrivial(ClassDecl->hasTrivialDestructor());
11558 Destructor->setTrivialForCall(ClassDecl->hasAttr<TrivialABIAttr>() ||
11559 ClassDecl->hasTrivialDestructorForCall());
11561 // Note that we have declared this destructor.
11562 ++getASTContext().NumImplicitDestructorsDeclared;
11564 Scope *S = getScopeForContext(ClassDecl);
11565 CheckImplicitSpecialMemberDeclaration(S, Destructor);
11567 // We can't check whether an implicit destructor is deleted before we complete
11568 // the definition of the class, because its validity depends on the alignment
11569 // of the class. We'll check this from ActOnFields once the class is complete.
11570 if (ClassDecl->isCompleteDefinition() &&
11571 ShouldDeleteSpecialMember(Destructor, CXXDestructor))
11572 SetDeclDeleted(Destructor, ClassLoc);
11574 // Introduce this destructor into its scope.
11576 PushOnScopeChains(Destructor, S, false);
11577 ClassDecl->addDecl(Destructor);
11582 void Sema::DefineImplicitDestructor(SourceLocation CurrentLocation,
11583 CXXDestructorDecl *Destructor) {
11584 assert((Destructor->isDefaulted() &&
11585 !Destructor->doesThisDeclarationHaveABody() &&
11586 !Destructor->isDeleted()) &&
11587 "DefineImplicitDestructor - call it for implicit default dtor");
11588 if (Destructor->willHaveBody() || Destructor->isInvalidDecl())
11591 CXXRecordDecl *ClassDecl = Destructor->getParent();
11592 assert(ClassDecl && "DefineImplicitDestructor - invalid destructor");
11594 SynthesizedFunctionScope Scope(*this, Destructor);
11596 // The exception specification is needed because we are defining the
11598 ResolveExceptionSpec(CurrentLocation,
11599 Destructor->getType()->castAs<FunctionProtoType>());
11600 MarkVTableUsed(CurrentLocation, ClassDecl);
11602 // Add a context note for diagnostics produced after this point.
11603 Scope.addContextNote(CurrentLocation);
11605 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
11606 Destructor->getParent());
11608 if (CheckDestructor(Destructor)) {
11609 Destructor->setInvalidDecl();
11613 SourceLocation Loc = Destructor->getEndLoc().isValid()
11614 ? Destructor->getEndLoc()
11615 : Destructor->getLocation();
11616 Destructor->setBody(new (Context) CompoundStmt(Loc));
11617 Destructor->markUsed(Context);
11619 if (ASTMutationListener *L = getASTMutationListener()) {
11620 L->CompletedImplicitDefinition(Destructor);
11624 /// Perform any semantic analysis which needs to be delayed until all
11625 /// pending class member declarations have been parsed.
11626 void Sema::ActOnFinishCXXMemberDecls() {
11627 // If the context is an invalid C++ class, just suppress these checks.
11628 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(CurContext)) {
11629 if (Record->isInvalidDecl()) {
11630 DelayedOverridingExceptionSpecChecks.clear();
11631 DelayedEquivalentExceptionSpecChecks.clear();
11634 checkForMultipleExportedDefaultConstructors(*this, Record);
11638 void Sema::ActOnFinishCXXNonNestedClass(Decl *D) {
11639 referenceDLLExportedClassMethods();
11641 if (!DelayedDllExportMemberFunctions.empty()) {
11642 SmallVector<CXXMethodDecl*, 4> WorkList;
11643 std::swap(DelayedDllExportMemberFunctions, WorkList);
11644 for (CXXMethodDecl *M : WorkList) {
11645 DefineImplicitSpecialMember(*this, M, M->getLocation());
11647 // Pass the method to the consumer to get emitted. This is not necessary
11648 // for explicit instantiation definitions, as they will get emitted
11650 if (M->getParent()->getTemplateSpecializationKind() !=
11651 TSK_ExplicitInstantiationDefinition)
11652 ActOnFinishInlineFunctionDef(M);
11657 void Sema::referenceDLLExportedClassMethods() {
11658 if (!DelayedDllExportClasses.empty()) {
11659 // Calling ReferenceDllExportedMembers might cause the current function to
11660 // be called again, so use a local copy of DelayedDllExportClasses.
11661 SmallVector<CXXRecordDecl *, 4> WorkList;
11662 std::swap(DelayedDllExportClasses, WorkList);
11663 for (CXXRecordDecl *Class : WorkList)
11664 ReferenceDllExportedMembers(*this, Class);
11668 void Sema::AdjustDestructorExceptionSpec(CXXDestructorDecl *Destructor) {
11669 assert(getLangOpts().CPlusPlus11 &&
11670 "adjusting dtor exception specs was introduced in c++11");
11672 if (Destructor->isDependentContext())
11675 // C++11 [class.dtor]p3:
11676 // A declaration of a destructor that does not have an exception-
11677 // specification is implicitly considered to have the same exception-
11678 // specification as an implicit declaration.
11679 const FunctionProtoType *DtorType = Destructor->getType()->
11680 getAs<FunctionProtoType>();
11681 if (DtorType->hasExceptionSpec())
11684 // Replace the destructor's type, building off the existing one. Fortunately,
11685 // the only thing of interest in the destructor type is its extended info.
11686 // The return and arguments are fixed.
11687 FunctionProtoType::ExtProtoInfo EPI = DtorType->getExtProtoInfo();
11688 EPI.ExceptionSpec.Type = EST_Unevaluated;
11689 EPI.ExceptionSpec.SourceDecl = Destructor;
11690 Destructor->setType(Context.getFunctionType(Context.VoidTy, None, EPI));
11692 // FIXME: If the destructor has a body that could throw, and the newly created
11693 // spec doesn't allow exceptions, we should emit a warning, because this
11694 // change in behavior can break conforming C++03 programs at runtime.
11695 // However, we don't have a body or an exception specification yet, so it
11696 // needs to be done somewhere else.
11700 /// An abstract base class for all helper classes used in building the
11701 // copy/move operators. These classes serve as factory functions and help us
11702 // avoid using the same Expr* in the AST twice.
11703 class ExprBuilder {
11704 ExprBuilder(const ExprBuilder&) = delete;
11705 ExprBuilder &operator=(const ExprBuilder&) = delete;
11708 static Expr *assertNotNull(Expr *E) {
11709 assert(E && "Expression construction must not fail.");
11715 virtual ~ExprBuilder() {}
11717 virtual Expr *build(Sema &S, SourceLocation Loc) const = 0;
11720 class RefBuilder: public ExprBuilder {
11725 Expr *build(Sema &S, SourceLocation Loc) const override {
11726 return assertNotNull(S.BuildDeclRefExpr(Var, VarType, VK_LValue, Loc));
11729 RefBuilder(VarDecl *Var, QualType VarType)
11730 : Var(Var), VarType(VarType) {}
11733 class ThisBuilder: public ExprBuilder {
11735 Expr *build(Sema &S, SourceLocation Loc) const override {
11736 return assertNotNull(S.ActOnCXXThis(Loc).getAs<Expr>());
11740 class CastBuilder: public ExprBuilder {
11741 const ExprBuilder &Builder;
11743 ExprValueKind Kind;
11744 const CXXCastPath &Path;
11747 Expr *build(Sema &S, SourceLocation Loc) const override {
11748 return assertNotNull(S.ImpCastExprToType(Builder.build(S, Loc), Type,
11749 CK_UncheckedDerivedToBase, Kind,
11753 CastBuilder(const ExprBuilder &Builder, QualType Type, ExprValueKind Kind,
11754 const CXXCastPath &Path)
11755 : Builder(Builder), Type(Type), Kind(Kind), Path(Path) {}
11758 class DerefBuilder: public ExprBuilder {
11759 const ExprBuilder &Builder;
11762 Expr *build(Sema &S, SourceLocation Loc) const override {
11763 return assertNotNull(
11764 S.CreateBuiltinUnaryOp(Loc, UO_Deref, Builder.build(S, Loc)).get());
11767 DerefBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
11770 class MemberBuilder: public ExprBuilder {
11771 const ExprBuilder &Builder;
11775 LookupResult &MemberLookup;
11778 Expr *build(Sema &S, SourceLocation Loc) const override {
11779 return assertNotNull(S.BuildMemberReferenceExpr(
11780 Builder.build(S, Loc), Type, Loc, IsArrow, SS, SourceLocation(),
11781 nullptr, MemberLookup, nullptr, nullptr).get());
11784 MemberBuilder(const ExprBuilder &Builder, QualType Type, bool IsArrow,
11785 LookupResult &MemberLookup)
11786 : Builder(Builder), Type(Type), IsArrow(IsArrow),
11787 MemberLookup(MemberLookup) {}
11790 class MoveCastBuilder: public ExprBuilder {
11791 const ExprBuilder &Builder;
11794 Expr *build(Sema &S, SourceLocation Loc) const override {
11795 return assertNotNull(CastForMoving(S, Builder.build(S, Loc)));
11798 MoveCastBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
11801 class LvalueConvBuilder: public ExprBuilder {
11802 const ExprBuilder &Builder;
11805 Expr *build(Sema &S, SourceLocation Loc) const override {
11806 return assertNotNull(
11807 S.DefaultLvalueConversion(Builder.build(S, Loc)).get());
11810 LvalueConvBuilder(const ExprBuilder &Builder) : Builder(Builder) {}
11813 class SubscriptBuilder: public ExprBuilder {
11814 const ExprBuilder &Base;
11815 const ExprBuilder &Index;
11818 Expr *build(Sema &S, SourceLocation Loc) const override {
11819 return assertNotNull(S.CreateBuiltinArraySubscriptExpr(
11820 Base.build(S, Loc), Loc, Index.build(S, Loc), Loc).get());
11823 SubscriptBuilder(const ExprBuilder &Base, const ExprBuilder &Index)
11824 : Base(Base), Index(Index) {}
11827 } // end anonymous namespace
11829 /// When generating a defaulted copy or move assignment operator, if a field
11830 /// should be copied with __builtin_memcpy rather than via explicit assignments,
11831 /// do so. This optimization only applies for arrays of scalars, and for arrays
11832 /// of class type where the selected copy/move-assignment operator is trivial.
11834 buildMemcpyForAssignmentOp(Sema &S, SourceLocation Loc, QualType T,
11835 const ExprBuilder &ToB, const ExprBuilder &FromB) {
11836 // Compute the size of the memory buffer to be copied.
11837 QualType SizeType = S.Context.getSizeType();
11838 llvm::APInt Size(S.Context.getTypeSize(SizeType),
11839 S.Context.getTypeSizeInChars(T).getQuantity());
11841 // Take the address of the field references for "from" and "to". We
11842 // directly construct UnaryOperators here because semantic analysis
11843 // does not permit us to take the address of an xvalue.
11844 Expr *From = FromB.build(S, Loc);
11845 From = new (S.Context) UnaryOperator(From, UO_AddrOf,
11846 S.Context.getPointerType(From->getType()),
11847 VK_RValue, OK_Ordinary, Loc, false);
11848 Expr *To = ToB.build(S, Loc);
11849 To = new (S.Context) UnaryOperator(To, UO_AddrOf,
11850 S.Context.getPointerType(To->getType()),
11851 VK_RValue, OK_Ordinary, Loc, false);
11853 const Type *E = T->getBaseElementTypeUnsafe();
11854 bool NeedsCollectableMemCpy =
11855 E->isRecordType() &&
11856 E->castAs<RecordType>()->getDecl()->hasObjectMember();
11858 // Create a reference to the __builtin_objc_memmove_collectable function
11859 StringRef MemCpyName = NeedsCollectableMemCpy ?
11860 "__builtin_objc_memmove_collectable" :
11861 "__builtin_memcpy";
11862 LookupResult R(S, &S.Context.Idents.get(MemCpyName), Loc,
11863 Sema::LookupOrdinaryName);
11864 S.LookupName(R, S.TUScope, true);
11866 FunctionDecl *MemCpy = R.getAsSingle<FunctionDecl>();
11868 // Something went horribly wrong earlier, and we will have complained
11870 return StmtError();
11872 ExprResult MemCpyRef = S.BuildDeclRefExpr(MemCpy, S.Context.BuiltinFnTy,
11873 VK_RValue, Loc, nullptr);
11874 assert(MemCpyRef.isUsable() && "Builtin reference cannot fail");
11876 Expr *CallArgs[] = {
11877 To, From, IntegerLiteral::Create(S.Context, Size, SizeType, Loc)
11879 ExprResult Call = S.BuildCallExpr(/*Scope=*/nullptr, MemCpyRef.get(),
11880 Loc, CallArgs, Loc);
11882 assert(!Call.isInvalid() && "Call to __builtin_memcpy cannot fail!");
11883 return Call.getAs<Stmt>();
11886 /// Builds a statement that copies/moves the given entity from \p From to
11889 /// This routine is used to copy/move the members of a class with an
11890 /// implicitly-declared copy/move assignment operator. When the entities being
11891 /// copied are arrays, this routine builds for loops to copy them.
11893 /// \param S The Sema object used for type-checking.
11895 /// \param Loc The location where the implicit copy/move is being generated.
11897 /// \param T The type of the expressions being copied/moved. Both expressions
11898 /// must have this type.
11900 /// \param To The expression we are copying/moving to.
11902 /// \param From The expression we are copying/moving from.
11904 /// \param CopyingBaseSubobject Whether we're copying/moving a base subobject.
11905 /// Otherwise, it's a non-static member subobject.
11907 /// \param Copying Whether we're copying or moving.
11909 /// \param Depth Internal parameter recording the depth of the recursion.
11911 /// \returns A statement or a loop that copies the expressions, or StmtResult(0)
11912 /// if a memcpy should be used instead.
11914 buildSingleCopyAssignRecursively(Sema &S, SourceLocation Loc, QualType T,
11915 const ExprBuilder &To, const ExprBuilder &From,
11916 bool CopyingBaseSubobject, bool Copying,
11917 unsigned Depth = 0) {
11918 // C++11 [class.copy]p28:
11919 // Each subobject is assigned in the manner appropriate to its type:
11921 // - if the subobject is of class type, as if by a call to operator= with
11922 // the subobject as the object expression and the corresponding
11923 // subobject of x as a single function argument (as if by explicit
11924 // qualification; that is, ignoring any possible virtual overriding
11925 // functions in more derived classes);
11927 // C++03 [class.copy]p13:
11928 // - if the subobject is of class type, the copy assignment operator for
11929 // the class is used (as if by explicit qualification; that is,
11930 // ignoring any possible virtual overriding functions in more derived
11932 if (const RecordType *RecordTy = T->getAs<RecordType>()) {
11933 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RecordTy->getDecl());
11935 // Look for operator=.
11936 DeclarationName Name
11937 = S.Context.DeclarationNames.getCXXOperatorName(OO_Equal);
11938 LookupResult OpLookup(S, Name, Loc, Sema::LookupOrdinaryName);
11939 S.LookupQualifiedName(OpLookup, ClassDecl, false);
11941 // Prior to C++11, filter out any result that isn't a copy/move-assignment
11943 if (!S.getLangOpts().CPlusPlus11) {
11944 LookupResult::Filter F = OpLookup.makeFilter();
11945 while (F.hasNext()) {
11946 NamedDecl *D = F.next();
11947 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D))
11948 if (Method->isCopyAssignmentOperator() ||
11949 (!Copying && Method->isMoveAssignmentOperator()))
11957 // Suppress the protected check (C++ [class.protected]) for each of the
11958 // assignment operators we found. This strange dance is required when
11959 // we're assigning via a base classes's copy-assignment operator. To
11960 // ensure that we're getting the right base class subobject (without
11961 // ambiguities), we need to cast "this" to that subobject type; to
11962 // ensure that we don't go through the virtual call mechanism, we need
11963 // to qualify the operator= name with the base class (see below). However,
11964 // this means that if the base class has a protected copy assignment
11965 // operator, the protected member access check will fail. So, we
11966 // rewrite "protected" access to "public" access in this case, since we
11967 // know by construction that we're calling from a derived class.
11968 if (CopyingBaseSubobject) {
11969 for (LookupResult::iterator L = OpLookup.begin(), LEnd = OpLookup.end();
11971 if (L.getAccess() == AS_protected)
11972 L.setAccess(AS_public);
11976 // Create the nested-name-specifier that will be used to qualify the
11977 // reference to operator=; this is required to suppress the virtual
11980 const Type *CanonicalT = S.Context.getCanonicalType(T.getTypePtr());
11981 SS.MakeTrivial(S.Context,
11982 NestedNameSpecifier::Create(S.Context, nullptr, false,
11986 // Create the reference to operator=.
11987 ExprResult OpEqualRef
11988 = S.BuildMemberReferenceExpr(To.build(S, Loc), T, Loc, /*IsArrow=*/false,
11989 SS, /*TemplateKWLoc=*/SourceLocation(),
11990 /*FirstQualifierInScope=*/nullptr,
11992 /*TemplateArgs=*/nullptr, /*S*/nullptr,
11993 /*SuppressQualifierCheck=*/true);
11994 if (OpEqualRef.isInvalid())
11995 return StmtError();
11997 // Build the call to the assignment operator.
11999 Expr *FromInst = From.build(S, Loc);
12000 ExprResult Call = S.BuildCallToMemberFunction(/*Scope=*/nullptr,
12001 OpEqualRef.getAs<Expr>(),
12002 Loc, FromInst, Loc);
12003 if (Call.isInvalid())
12004 return StmtError();
12006 // If we built a call to a trivial 'operator=' while copying an array,
12007 // bail out. We'll replace the whole shebang with a memcpy.
12008 CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(Call.get());
12009 if (CE && CE->getMethodDecl()->isTrivial() && Depth)
12010 return StmtResult((Stmt*)nullptr);
12012 // Convert to an expression-statement, and clean up any produced
12014 return S.ActOnExprStmt(Call);
12017 // - if the subobject is of scalar type, the built-in assignment
12018 // operator is used.
12019 const ConstantArrayType *ArrayTy = S.Context.getAsConstantArrayType(T);
12021 ExprResult Assignment = S.CreateBuiltinBinOp(
12022 Loc, BO_Assign, To.build(S, Loc), From.build(S, Loc));
12023 if (Assignment.isInvalid())
12024 return StmtError();
12025 return S.ActOnExprStmt(Assignment);
12028 // - if the subobject is an array, each element is assigned, in the
12029 // manner appropriate to the element type;
12031 // Construct a loop over the array bounds, e.g.,
12033 // for (__SIZE_TYPE__ i0 = 0; i0 != array-size; ++i0)
12035 // that will copy each of the array elements.
12036 QualType SizeType = S.Context.getSizeType();
12038 // Create the iteration variable.
12039 IdentifierInfo *IterationVarName = nullptr;
12041 SmallString<8> Str;
12042 llvm::raw_svector_ostream OS(Str);
12043 OS << "__i" << Depth;
12044 IterationVarName = &S.Context.Idents.get(OS.str());
12046 VarDecl *IterationVar = VarDecl::Create(S.Context, S.CurContext, Loc, Loc,
12047 IterationVarName, SizeType,
12048 S.Context.getTrivialTypeSourceInfo(SizeType, Loc),
12051 // Initialize the iteration variable to zero.
12052 llvm::APInt Zero(S.Context.getTypeSize(SizeType), 0);
12053 IterationVar->setInit(IntegerLiteral::Create(S.Context, Zero, SizeType, Loc));
12055 // Creates a reference to the iteration variable.
12056 RefBuilder IterationVarRef(IterationVar, SizeType);
12057 LvalueConvBuilder IterationVarRefRVal(IterationVarRef);
12059 // Create the DeclStmt that holds the iteration variable.
12060 Stmt *InitStmt = new (S.Context) DeclStmt(DeclGroupRef(IterationVar),Loc,Loc);
12062 // Subscript the "from" and "to" expressions with the iteration variable.
12063 SubscriptBuilder FromIndexCopy(From, IterationVarRefRVal);
12064 MoveCastBuilder FromIndexMove(FromIndexCopy);
12065 const ExprBuilder *FromIndex;
12067 FromIndex = &FromIndexCopy;
12069 FromIndex = &FromIndexMove;
12071 SubscriptBuilder ToIndex(To, IterationVarRefRVal);
12073 // Build the copy/move for an individual element of the array.
12075 buildSingleCopyAssignRecursively(S, Loc, ArrayTy->getElementType(),
12076 ToIndex, *FromIndex, CopyingBaseSubobject,
12077 Copying, Depth + 1);
12078 // Bail out if copying fails or if we determined that we should use memcpy.
12079 if (Copy.isInvalid() || !Copy.get())
12082 // Create the comparison against the array bound.
12084 = ArrayTy->getSize().zextOrTrunc(S.Context.getTypeSize(SizeType));
12086 = new (S.Context) BinaryOperator(IterationVarRefRVal.build(S, Loc),
12087 IntegerLiteral::Create(S.Context, Upper, SizeType, Loc),
12088 BO_NE, S.Context.BoolTy,
12089 VK_RValue, OK_Ordinary, Loc, FPOptions());
12091 // Create the pre-increment of the iteration variable. We can determine
12092 // whether the increment will overflow based on the value of the array
12094 Expr *Increment = new (S.Context)
12095 UnaryOperator(IterationVarRef.build(S, Loc), UO_PreInc, SizeType,
12096 VK_LValue, OK_Ordinary, Loc, Upper.isMaxValue());
12098 // Construct the loop that copies all elements of this array.
12099 return S.ActOnForStmt(
12100 Loc, Loc, InitStmt,
12101 S.ActOnCondition(nullptr, Loc, Comparison, Sema::ConditionKind::Boolean),
12102 S.MakeFullDiscardedValueExpr(Increment), Loc, Copy.get());
12106 buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
12107 const ExprBuilder &To, const ExprBuilder &From,
12108 bool CopyingBaseSubobject, bool Copying) {
12109 // Maybe we should use a memcpy?
12110 if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
12111 T.isTriviallyCopyableType(S.Context))
12112 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
12114 StmtResult Result(buildSingleCopyAssignRecursively(S, Loc, T, To, From,
12115 CopyingBaseSubobject,
12118 // If we ended up picking a trivial assignment operator for an array of a
12119 // non-trivially-copyable class type, just emit a memcpy.
12120 if (!Result.isInvalid() && !Result.get())
12121 return buildMemcpyForAssignmentOp(S, Loc, T, To, From);
12126 CXXMethodDecl *Sema::DeclareImplicitCopyAssignment(CXXRecordDecl *ClassDecl) {
12127 // Note: The following rules are largely analoguous to the copy
12128 // constructor rules. Note that virtual bases are not taken into account
12129 // for determining the argument type of the operator. Note also that
12130 // operators taking an object instead of a reference are allowed.
12131 assert(ClassDecl->needsImplicitCopyAssignment());
12133 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyAssignment);
12134 if (DSM.isAlreadyBeingDeclared())
12137 QualType ArgType = Context.getTypeDeclType(ClassDecl);
12138 if (Context.getLangOpts().OpenCLCPlusPlus)
12139 ArgType = Context.getAddrSpaceQualType(ArgType, LangAS::opencl_generic);
12140 QualType RetType = Context.getLValueReferenceType(ArgType);
12141 bool Const = ClassDecl->implicitCopyAssignmentHasConstParam();
12143 ArgType = ArgType.withConst();
12145 ArgType = Context.getLValueReferenceType(ArgType);
12147 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12151 // An implicitly-declared copy assignment operator is an inline public
12152 // member of its class.
12153 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
12154 SourceLocation ClassLoc = ClassDecl->getLocation();
12155 DeclarationNameInfo NameInfo(Name, ClassLoc);
12156 CXXMethodDecl *CopyAssignment = CXXMethodDecl::Create(
12157 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
12158 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
12159 /*isInline=*/true, Constexpr ? CSK_constexpr : CSK_unspecified,
12161 CopyAssignment->setAccess(AS_public);
12162 CopyAssignment->setDefaulted();
12163 CopyAssignment->setImplicit();
12165 if (getLangOpts().CUDA) {
12166 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyAssignment,
12168 /* ConstRHS */ Const,
12169 /* Diagnose */ false);
12172 setupImplicitSpecialMemberType(CopyAssignment, RetType, ArgType);
12174 // Add the parameter to the operator.
12175 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyAssignment,
12176 ClassLoc, ClassLoc,
12177 /*Id=*/nullptr, ArgType,
12178 /*TInfo=*/nullptr, SC_None,
12180 CopyAssignment->setParams(FromParam);
12182 CopyAssignment->setTrivial(
12183 ClassDecl->needsOverloadResolutionForCopyAssignment()
12184 ? SpecialMemberIsTrivial(CopyAssignment, CXXCopyAssignment)
12185 : ClassDecl->hasTrivialCopyAssignment());
12187 // Note that we have added this copy-assignment operator.
12188 ++getASTContext().NumImplicitCopyAssignmentOperatorsDeclared;
12190 Scope *S = getScopeForContext(ClassDecl);
12191 CheckImplicitSpecialMemberDeclaration(S, CopyAssignment);
12193 if (ShouldDeleteSpecialMember(CopyAssignment, CXXCopyAssignment))
12194 SetDeclDeleted(CopyAssignment, ClassLoc);
12197 PushOnScopeChains(CopyAssignment, S, false);
12198 ClassDecl->addDecl(CopyAssignment);
12200 return CopyAssignment;
12203 /// Diagnose an implicit copy operation for a class which is odr-used, but
12204 /// which is deprecated because the class has a user-declared copy constructor,
12205 /// copy assignment operator, or destructor.
12206 static void diagnoseDeprecatedCopyOperation(Sema &S, CXXMethodDecl *CopyOp) {
12207 assert(CopyOp->isImplicit());
12209 CXXRecordDecl *RD = CopyOp->getParent();
12210 CXXMethodDecl *UserDeclaredOperation = nullptr;
12212 // In Microsoft mode, assignment operations don't affect constructors and
12214 if (RD->hasUserDeclaredDestructor()) {
12215 UserDeclaredOperation = RD->getDestructor();
12216 } else if (!isa<CXXConstructorDecl>(CopyOp) &&
12217 RD->hasUserDeclaredCopyConstructor() &&
12218 !S.getLangOpts().MSVCCompat) {
12219 // Find any user-declared copy constructor.
12220 for (auto *I : RD->ctors()) {
12221 if (I->isCopyConstructor()) {
12222 UserDeclaredOperation = I;
12226 assert(UserDeclaredOperation);
12227 } else if (isa<CXXConstructorDecl>(CopyOp) &&
12228 RD->hasUserDeclaredCopyAssignment() &&
12229 !S.getLangOpts().MSVCCompat) {
12230 // Find any user-declared move assignment operator.
12231 for (auto *I : RD->methods()) {
12232 if (I->isCopyAssignmentOperator()) {
12233 UserDeclaredOperation = I;
12237 assert(UserDeclaredOperation);
12240 if (UserDeclaredOperation) {
12241 S.Diag(UserDeclaredOperation->getLocation(),
12242 diag::warn_deprecated_copy_operation)
12243 << RD << /*copy assignment*/!isa<CXXConstructorDecl>(CopyOp)
12244 << /*destructor*/isa<CXXDestructorDecl>(UserDeclaredOperation);
12248 void Sema::DefineImplicitCopyAssignment(SourceLocation CurrentLocation,
12249 CXXMethodDecl *CopyAssignOperator) {
12250 assert((CopyAssignOperator->isDefaulted() &&
12251 CopyAssignOperator->isOverloadedOperator() &&
12252 CopyAssignOperator->getOverloadedOperator() == OO_Equal &&
12253 !CopyAssignOperator->doesThisDeclarationHaveABody() &&
12254 !CopyAssignOperator->isDeleted()) &&
12255 "DefineImplicitCopyAssignment called for wrong function");
12256 if (CopyAssignOperator->willHaveBody() || CopyAssignOperator->isInvalidDecl())
12259 CXXRecordDecl *ClassDecl = CopyAssignOperator->getParent();
12260 if (ClassDecl->isInvalidDecl()) {
12261 CopyAssignOperator->setInvalidDecl();
12265 SynthesizedFunctionScope Scope(*this, CopyAssignOperator);
12267 // The exception specification is needed because we are defining the
12269 ResolveExceptionSpec(CurrentLocation,
12270 CopyAssignOperator->getType()->castAs<FunctionProtoType>());
12272 // Add a context note for diagnostics produced after this point.
12273 Scope.addContextNote(CurrentLocation);
12275 // C++11 [class.copy]p18:
12276 // The [definition of an implicitly declared copy assignment operator] is
12277 // deprecated if the class has a user-declared copy constructor or a
12278 // user-declared destructor.
12279 if (getLangOpts().CPlusPlus11 && CopyAssignOperator->isImplicit())
12280 diagnoseDeprecatedCopyOperation(*this, CopyAssignOperator);
12282 // C++0x [class.copy]p30:
12283 // The implicitly-defined or explicitly-defaulted copy assignment operator
12284 // for a non-union class X performs memberwise copy assignment of its
12285 // subobjects. The direct base classes of X are assigned first, in the
12286 // order of their declaration in the base-specifier-list, and then the
12287 // immediate non-static data members of X are assigned, in the order in
12288 // which they were declared in the class definition.
12290 // The statements that form the synthesized function body.
12291 SmallVector<Stmt*, 8> Statements;
12293 // The parameter for the "other" object, which we are copying from.
12294 ParmVarDecl *Other = CopyAssignOperator->getParamDecl(0);
12295 Qualifiers OtherQuals = Other->getType().getQualifiers();
12296 QualType OtherRefType = Other->getType();
12297 if (const LValueReferenceType *OtherRef
12298 = OtherRefType->getAs<LValueReferenceType>()) {
12299 OtherRefType = OtherRef->getPointeeType();
12300 OtherQuals = OtherRefType.getQualifiers();
12303 // Our location for everything implicitly-generated.
12304 SourceLocation Loc = CopyAssignOperator->getEndLoc().isValid()
12305 ? CopyAssignOperator->getEndLoc()
12306 : CopyAssignOperator->getLocation();
12308 // Builds a DeclRefExpr for the "other" object.
12309 RefBuilder OtherRef(Other, OtherRefType);
12311 // Builds the "this" pointer.
12314 // Assign base classes.
12315 bool Invalid = false;
12316 for (auto &Base : ClassDecl->bases()) {
12317 // Form the assignment:
12318 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&>(other));
12319 QualType BaseType = Base.getType().getUnqualifiedType();
12320 if (!BaseType->isRecordType()) {
12325 CXXCastPath BasePath;
12326 BasePath.push_back(&Base);
12328 // Construct the "from" expression, which is an implicit cast to the
12329 // appropriately-qualified base type.
12330 CastBuilder From(OtherRef, Context.getQualifiedType(BaseType, OtherQuals),
12331 VK_LValue, BasePath);
12333 // Dereference "this".
12334 DerefBuilder DerefThis(This);
12335 CastBuilder To(DerefThis,
12336 Context.getQualifiedType(
12337 BaseType, CopyAssignOperator->getMethodQualifiers()),
12338 VK_LValue, BasePath);
12341 StmtResult Copy = buildSingleCopyAssign(*this, Loc, BaseType,
12343 /*CopyingBaseSubobject=*/true,
12345 if (Copy.isInvalid()) {
12346 CopyAssignOperator->setInvalidDecl();
12350 // Success! Record the copy.
12351 Statements.push_back(Copy.getAs<Expr>());
12354 // Assign non-static members.
12355 for (auto *Field : ClassDecl->fields()) {
12356 // FIXME: We should form some kind of AST representation for the implied
12357 // memcpy in a union copy operation.
12358 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
12361 if (Field->isInvalidDecl()) {
12366 // Check for members of reference type; we can't copy those.
12367 if (Field->getType()->isReferenceType()) {
12368 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
12369 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
12370 Diag(Field->getLocation(), diag::note_declared_at);
12375 // Check for members of const-qualified, non-class type.
12376 QualType BaseType = Context.getBaseElementType(Field->getType());
12377 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
12378 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
12379 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
12380 Diag(Field->getLocation(), diag::note_declared_at);
12385 // Suppress assigning zero-width bitfields.
12386 if (Field->isZeroLengthBitField(Context))
12389 QualType FieldType = Field->getType().getNonReferenceType();
12390 if (FieldType->isIncompleteArrayType()) {
12391 assert(ClassDecl->hasFlexibleArrayMember() &&
12392 "Incomplete array type is not valid");
12396 // Build references to the field in the object we're copying from and to.
12397 CXXScopeSpec SS; // Intentionally empty
12398 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
12400 MemberLookup.addDecl(Field);
12401 MemberLookup.resolveKind();
12403 MemberBuilder From(OtherRef, OtherRefType, /*IsArrow=*/false, MemberLookup);
12405 MemberBuilder To(This, getCurrentThisType(), /*IsArrow=*/true, MemberLookup);
12407 // Build the copy of this field.
12408 StmtResult Copy = buildSingleCopyAssign(*this, Loc, FieldType,
12410 /*CopyingBaseSubobject=*/false,
12412 if (Copy.isInvalid()) {
12413 CopyAssignOperator->setInvalidDecl();
12417 // Success! Record the copy.
12418 Statements.push_back(Copy.getAs<Stmt>());
12422 // Add a "return *this;"
12423 ExprResult ThisObj = CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
12425 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
12426 if (Return.isInvalid())
12429 Statements.push_back(Return.getAs<Stmt>());
12433 CopyAssignOperator->setInvalidDecl();
12439 CompoundScopeRAII CompoundScope(*this);
12440 Body = ActOnCompoundStmt(Loc, Loc, Statements,
12441 /*isStmtExpr=*/false);
12442 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
12444 CopyAssignOperator->setBody(Body.getAs<Stmt>());
12445 CopyAssignOperator->markUsed(Context);
12447 if (ASTMutationListener *L = getASTMutationListener()) {
12448 L->CompletedImplicitDefinition(CopyAssignOperator);
12452 CXXMethodDecl *Sema::DeclareImplicitMoveAssignment(CXXRecordDecl *ClassDecl) {
12453 assert(ClassDecl->needsImplicitMoveAssignment());
12455 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveAssignment);
12456 if (DSM.isAlreadyBeingDeclared())
12459 // Note: The following rules are largely analoguous to the move
12460 // constructor rules.
12462 QualType ArgType = Context.getTypeDeclType(ClassDecl);
12463 if (Context.getLangOpts().OpenCLCPlusPlus)
12464 ArgType = Context.getAddrSpaceQualType(ArgType, LangAS::opencl_generic);
12465 QualType RetType = Context.getLValueReferenceType(ArgType);
12466 ArgType = Context.getRValueReferenceType(ArgType);
12468 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12472 // An implicitly-declared move assignment operator is an inline public
12473 // member of its class.
12474 DeclarationName Name = Context.DeclarationNames.getCXXOperatorName(OO_Equal);
12475 SourceLocation ClassLoc = ClassDecl->getLocation();
12476 DeclarationNameInfo NameInfo(Name, ClassLoc);
12477 CXXMethodDecl *MoveAssignment = CXXMethodDecl::Create(
12478 Context, ClassDecl, ClassLoc, NameInfo, QualType(),
12479 /*TInfo=*/nullptr, /*StorageClass=*/SC_None,
12480 /*isInline=*/true, Constexpr ? CSK_constexpr : CSK_unspecified,
12482 MoveAssignment->setAccess(AS_public);
12483 MoveAssignment->setDefaulted();
12484 MoveAssignment->setImplicit();
12486 if (getLangOpts().CUDA) {
12487 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveAssignment,
12489 /* ConstRHS */ false,
12490 /* Diagnose */ false);
12493 // Build an exception specification pointing back at this member.
12494 FunctionProtoType::ExtProtoInfo EPI =
12495 getImplicitMethodEPI(*this, MoveAssignment);
12496 MoveAssignment->setType(Context.getFunctionType(RetType, ArgType, EPI));
12498 // Add the parameter to the operator.
12499 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveAssignment,
12500 ClassLoc, ClassLoc,
12501 /*Id=*/nullptr, ArgType,
12502 /*TInfo=*/nullptr, SC_None,
12504 MoveAssignment->setParams(FromParam);
12506 MoveAssignment->setTrivial(
12507 ClassDecl->needsOverloadResolutionForMoveAssignment()
12508 ? SpecialMemberIsTrivial(MoveAssignment, CXXMoveAssignment)
12509 : ClassDecl->hasTrivialMoveAssignment());
12511 // Note that we have added this copy-assignment operator.
12512 ++getASTContext().NumImplicitMoveAssignmentOperatorsDeclared;
12514 Scope *S = getScopeForContext(ClassDecl);
12515 CheckImplicitSpecialMemberDeclaration(S, MoveAssignment);
12517 if (ShouldDeleteSpecialMember(MoveAssignment, CXXMoveAssignment)) {
12518 ClassDecl->setImplicitMoveAssignmentIsDeleted();
12519 SetDeclDeleted(MoveAssignment, ClassLoc);
12523 PushOnScopeChains(MoveAssignment, S, false);
12524 ClassDecl->addDecl(MoveAssignment);
12526 return MoveAssignment;
12529 /// Check if we're implicitly defining a move assignment operator for a class
12530 /// with virtual bases. Such a move assignment might move-assign the virtual
12531 /// base multiple times.
12532 static void checkMoveAssignmentForRepeatedMove(Sema &S, CXXRecordDecl *Class,
12533 SourceLocation CurrentLocation) {
12534 assert(!Class->isDependentContext() && "should not define dependent move");
12536 // Only a virtual base could get implicitly move-assigned multiple times.
12537 // Only a non-trivial move assignment can observe this. We only want to
12538 // diagnose if we implicitly define an assignment operator that assigns
12539 // two base classes, both of which move-assign the same virtual base.
12540 if (Class->getNumVBases() == 0 || Class->hasTrivialMoveAssignment() ||
12541 Class->getNumBases() < 2)
12544 llvm::SmallVector<CXXBaseSpecifier *, 16> Worklist;
12545 typedef llvm::DenseMap<CXXRecordDecl*, CXXBaseSpecifier*> VBaseMap;
12548 for (auto &BI : Class->bases()) {
12549 Worklist.push_back(&BI);
12550 while (!Worklist.empty()) {
12551 CXXBaseSpecifier *BaseSpec = Worklist.pop_back_val();
12552 CXXRecordDecl *Base = BaseSpec->getType()->getAsCXXRecordDecl();
12554 // If the base has no non-trivial move assignment operators,
12555 // we don't care about moves from it.
12556 if (!Base->hasNonTrivialMoveAssignment())
12559 // If there's nothing virtual here, skip it.
12560 if (!BaseSpec->isVirtual() && !Base->getNumVBases())
12563 // If we're not actually going to call a move assignment for this base,
12564 // or the selected move assignment is trivial, skip it.
12565 Sema::SpecialMemberOverloadResult SMOR =
12566 S.LookupSpecialMember(Base, Sema::CXXMoveAssignment,
12567 /*ConstArg*/false, /*VolatileArg*/false,
12568 /*RValueThis*/true, /*ConstThis*/false,
12569 /*VolatileThis*/false);
12570 if (!SMOR.getMethod() || SMOR.getMethod()->isTrivial() ||
12571 !SMOR.getMethod()->isMoveAssignmentOperator())
12574 if (BaseSpec->isVirtual()) {
12575 // We're going to move-assign this virtual base, and its move
12576 // assignment operator is not trivial. If this can happen for
12577 // multiple distinct direct bases of Class, diagnose it. (If it
12578 // only happens in one base, we'll diagnose it when synthesizing
12579 // that base class's move assignment operator.)
12580 CXXBaseSpecifier *&Existing =
12581 VBases.insert(std::make_pair(Base->getCanonicalDecl(), &BI))
12583 if (Existing && Existing != &BI) {
12584 S.Diag(CurrentLocation, diag::warn_vbase_moved_multiple_times)
12586 S.Diag(Existing->getBeginLoc(), diag::note_vbase_moved_here)
12587 << (Base->getCanonicalDecl() ==
12588 Existing->getType()->getAsCXXRecordDecl()->getCanonicalDecl())
12589 << Base << Existing->getType() << Existing->getSourceRange();
12590 S.Diag(BI.getBeginLoc(), diag::note_vbase_moved_here)
12591 << (Base->getCanonicalDecl() ==
12592 BI.getType()->getAsCXXRecordDecl()->getCanonicalDecl())
12593 << Base << BI.getType() << BaseSpec->getSourceRange();
12595 // Only diagnose each vbase once.
12596 Existing = nullptr;
12599 // Only walk over bases that have defaulted move assignment operators.
12600 // We assume that any user-provided move assignment operator handles
12601 // the multiple-moves-of-vbase case itself somehow.
12602 if (!SMOR.getMethod()->isDefaulted())
12605 // We're going to move the base classes of Base. Add them to the list.
12606 for (auto &BI : Base->bases())
12607 Worklist.push_back(&BI);
12613 void Sema::DefineImplicitMoveAssignment(SourceLocation CurrentLocation,
12614 CXXMethodDecl *MoveAssignOperator) {
12615 assert((MoveAssignOperator->isDefaulted() &&
12616 MoveAssignOperator->isOverloadedOperator() &&
12617 MoveAssignOperator->getOverloadedOperator() == OO_Equal &&
12618 !MoveAssignOperator->doesThisDeclarationHaveABody() &&
12619 !MoveAssignOperator->isDeleted()) &&
12620 "DefineImplicitMoveAssignment called for wrong function");
12621 if (MoveAssignOperator->willHaveBody() || MoveAssignOperator->isInvalidDecl())
12624 CXXRecordDecl *ClassDecl = MoveAssignOperator->getParent();
12625 if (ClassDecl->isInvalidDecl()) {
12626 MoveAssignOperator->setInvalidDecl();
12630 // C++0x [class.copy]p28:
12631 // The implicitly-defined or move assignment operator for a non-union class
12632 // X performs memberwise move assignment of its subobjects. The direct base
12633 // classes of X are assigned first, in the order of their declaration in the
12634 // base-specifier-list, and then the immediate non-static data members of X
12635 // are assigned, in the order in which they were declared in the class
12638 // Issue a warning if our implicit move assignment operator will move
12639 // from a virtual base more than once.
12640 checkMoveAssignmentForRepeatedMove(*this, ClassDecl, CurrentLocation);
12642 SynthesizedFunctionScope Scope(*this, MoveAssignOperator);
12644 // The exception specification is needed because we are defining the
12646 ResolveExceptionSpec(CurrentLocation,
12647 MoveAssignOperator->getType()->castAs<FunctionProtoType>());
12649 // Add a context note for diagnostics produced after this point.
12650 Scope.addContextNote(CurrentLocation);
12652 // The statements that form the synthesized function body.
12653 SmallVector<Stmt*, 8> Statements;
12655 // The parameter for the "other" object, which we are move from.
12656 ParmVarDecl *Other = MoveAssignOperator->getParamDecl(0);
12657 QualType OtherRefType = Other->getType()->
12658 getAs<RValueReferenceType>()->getPointeeType();
12660 // Our location for everything implicitly-generated.
12661 SourceLocation Loc = MoveAssignOperator->getEndLoc().isValid()
12662 ? MoveAssignOperator->getEndLoc()
12663 : MoveAssignOperator->getLocation();
12665 // Builds a reference to the "other" object.
12666 RefBuilder OtherRef(Other, OtherRefType);
12668 MoveCastBuilder MoveOther(OtherRef);
12670 // Builds the "this" pointer.
12673 // Assign base classes.
12674 bool Invalid = false;
12675 for (auto &Base : ClassDecl->bases()) {
12676 // C++11 [class.copy]p28:
12677 // It is unspecified whether subobjects representing virtual base classes
12678 // are assigned more than once by the implicitly-defined copy assignment
12680 // FIXME: Do not assign to a vbase that will be assigned by some other base
12681 // class. For a move-assignment, this can result in the vbase being moved
12684 // Form the assignment:
12685 // static_cast<Base*>(this)->Base::operator=(static_cast<Base&&>(other));
12686 QualType BaseType = Base.getType().getUnqualifiedType();
12687 if (!BaseType->isRecordType()) {
12692 CXXCastPath BasePath;
12693 BasePath.push_back(&Base);
12695 // Construct the "from" expression, which is an implicit cast to the
12696 // appropriately-qualified base type.
12697 CastBuilder From(OtherRef, BaseType, VK_XValue, BasePath);
12699 // Dereference "this".
12700 DerefBuilder DerefThis(This);
12702 // Implicitly cast "this" to the appropriately-qualified base type.
12703 CastBuilder To(DerefThis,
12704 Context.getQualifiedType(
12705 BaseType, MoveAssignOperator->getMethodQualifiers()),
12706 VK_LValue, BasePath);
12709 StmtResult Move = buildSingleCopyAssign(*this, Loc, BaseType,
12711 /*CopyingBaseSubobject=*/true,
12712 /*Copying=*/false);
12713 if (Move.isInvalid()) {
12714 MoveAssignOperator->setInvalidDecl();
12718 // Success! Record the move.
12719 Statements.push_back(Move.getAs<Expr>());
12722 // Assign non-static members.
12723 for (auto *Field : ClassDecl->fields()) {
12724 // FIXME: We should form some kind of AST representation for the implied
12725 // memcpy in a union copy operation.
12726 if (Field->isUnnamedBitfield() || Field->getParent()->isUnion())
12729 if (Field->isInvalidDecl()) {
12734 // Check for members of reference type; we can't move those.
12735 if (Field->getType()->isReferenceType()) {
12736 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
12737 << Context.getTagDeclType(ClassDecl) << 0 << Field->getDeclName();
12738 Diag(Field->getLocation(), diag::note_declared_at);
12743 // Check for members of const-qualified, non-class type.
12744 QualType BaseType = Context.getBaseElementType(Field->getType());
12745 if (!BaseType->getAs<RecordType>() && BaseType.isConstQualified()) {
12746 Diag(ClassDecl->getLocation(), diag::err_uninitialized_member_for_assign)
12747 << Context.getTagDeclType(ClassDecl) << 1 << Field->getDeclName();
12748 Diag(Field->getLocation(), diag::note_declared_at);
12753 // Suppress assigning zero-width bitfields.
12754 if (Field->isZeroLengthBitField(Context))
12757 QualType FieldType = Field->getType().getNonReferenceType();
12758 if (FieldType->isIncompleteArrayType()) {
12759 assert(ClassDecl->hasFlexibleArrayMember() &&
12760 "Incomplete array type is not valid");
12764 // Build references to the field in the object we're copying from and to.
12765 LookupResult MemberLookup(*this, Field->getDeclName(), Loc,
12767 MemberLookup.addDecl(Field);
12768 MemberLookup.resolveKind();
12769 MemberBuilder From(MoveOther, OtherRefType,
12770 /*IsArrow=*/false, MemberLookup);
12771 MemberBuilder To(This, getCurrentThisType(),
12772 /*IsArrow=*/true, MemberLookup);
12774 assert(!From.build(*this, Loc)->isLValue() && // could be xvalue or prvalue
12775 "Member reference with rvalue base must be rvalue except for reference "
12776 "members, which aren't allowed for move assignment.");
12778 // Build the move of this field.
12779 StmtResult Move = buildSingleCopyAssign(*this, Loc, FieldType,
12781 /*CopyingBaseSubobject=*/false,
12782 /*Copying=*/false);
12783 if (Move.isInvalid()) {
12784 MoveAssignOperator->setInvalidDecl();
12788 // Success! Record the copy.
12789 Statements.push_back(Move.getAs<Stmt>());
12793 // Add a "return *this;"
12794 ExprResult ThisObj =
12795 CreateBuiltinUnaryOp(Loc, UO_Deref, This.build(*this, Loc));
12797 StmtResult Return = BuildReturnStmt(Loc, ThisObj.get());
12798 if (Return.isInvalid())
12801 Statements.push_back(Return.getAs<Stmt>());
12805 MoveAssignOperator->setInvalidDecl();
12811 CompoundScopeRAII CompoundScope(*this);
12812 Body = ActOnCompoundStmt(Loc, Loc, Statements,
12813 /*isStmtExpr=*/false);
12814 assert(!Body.isInvalid() && "Compound statement creation cannot fail");
12816 MoveAssignOperator->setBody(Body.getAs<Stmt>());
12817 MoveAssignOperator->markUsed(Context);
12819 if (ASTMutationListener *L = getASTMutationListener()) {
12820 L->CompletedImplicitDefinition(MoveAssignOperator);
12824 CXXConstructorDecl *Sema::DeclareImplicitCopyConstructor(
12825 CXXRecordDecl *ClassDecl) {
12826 // C++ [class.copy]p4:
12827 // If the class definition does not explicitly declare a copy
12828 // constructor, one is declared implicitly.
12829 assert(ClassDecl->needsImplicitCopyConstructor());
12831 DeclaringSpecialMember DSM(*this, ClassDecl, CXXCopyConstructor);
12832 if (DSM.isAlreadyBeingDeclared())
12835 QualType ClassType = Context.getTypeDeclType(ClassDecl);
12836 QualType ArgType = ClassType;
12837 bool Const = ClassDecl->implicitCopyConstructorHasConstParam();
12839 ArgType = ArgType.withConst();
12841 if (Context.getLangOpts().OpenCLCPlusPlus)
12842 ArgType = Context.getAddrSpaceQualType(ArgType, LangAS::opencl_generic);
12844 ArgType = Context.getLValueReferenceType(ArgType);
12846 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12847 CXXCopyConstructor,
12850 DeclarationName Name
12851 = Context.DeclarationNames.getCXXConstructorName(
12852 Context.getCanonicalType(ClassType));
12853 SourceLocation ClassLoc = ClassDecl->getLocation();
12854 DeclarationNameInfo NameInfo(Name, ClassLoc);
12856 // An implicitly-declared copy constructor is an inline public
12857 // member of its class.
12858 CXXConstructorDecl *CopyConstructor = CXXConstructorDecl::Create(
12859 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
12860 ExplicitSpecifier(),
12862 /*isImplicitlyDeclared=*/true,
12863 Constexpr ? CSK_constexpr : CSK_unspecified);
12864 CopyConstructor->setAccess(AS_public);
12865 CopyConstructor->setDefaulted();
12867 if (getLangOpts().CUDA) {
12868 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXCopyConstructor,
12870 /* ConstRHS */ Const,
12871 /* Diagnose */ false);
12874 setupImplicitSpecialMemberType(CopyConstructor, Context.VoidTy, ArgType);
12876 // Add the parameter to the constructor.
12877 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, CopyConstructor,
12878 ClassLoc, ClassLoc,
12879 /*IdentifierInfo=*/nullptr,
12880 ArgType, /*TInfo=*/nullptr,
12882 CopyConstructor->setParams(FromParam);
12884 CopyConstructor->setTrivial(
12885 ClassDecl->needsOverloadResolutionForCopyConstructor()
12886 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor)
12887 : ClassDecl->hasTrivialCopyConstructor());
12889 CopyConstructor->setTrivialForCall(
12890 ClassDecl->hasAttr<TrivialABIAttr>() ||
12891 (ClassDecl->needsOverloadResolutionForCopyConstructor()
12892 ? SpecialMemberIsTrivial(CopyConstructor, CXXCopyConstructor,
12893 TAH_ConsiderTrivialABI)
12894 : ClassDecl->hasTrivialCopyConstructorForCall()));
12896 // Note that we have declared this constructor.
12897 ++getASTContext().NumImplicitCopyConstructorsDeclared;
12899 Scope *S = getScopeForContext(ClassDecl);
12900 CheckImplicitSpecialMemberDeclaration(S, CopyConstructor);
12902 if (ShouldDeleteSpecialMember(CopyConstructor, CXXCopyConstructor)) {
12903 ClassDecl->setImplicitCopyConstructorIsDeleted();
12904 SetDeclDeleted(CopyConstructor, ClassLoc);
12908 PushOnScopeChains(CopyConstructor, S, false);
12909 ClassDecl->addDecl(CopyConstructor);
12911 return CopyConstructor;
12914 void Sema::DefineImplicitCopyConstructor(SourceLocation CurrentLocation,
12915 CXXConstructorDecl *CopyConstructor) {
12916 assert((CopyConstructor->isDefaulted() &&
12917 CopyConstructor->isCopyConstructor() &&
12918 !CopyConstructor->doesThisDeclarationHaveABody() &&
12919 !CopyConstructor->isDeleted()) &&
12920 "DefineImplicitCopyConstructor - call it for implicit copy ctor");
12921 if (CopyConstructor->willHaveBody() || CopyConstructor->isInvalidDecl())
12924 CXXRecordDecl *ClassDecl = CopyConstructor->getParent();
12925 assert(ClassDecl && "DefineImplicitCopyConstructor - invalid constructor");
12927 SynthesizedFunctionScope Scope(*this, CopyConstructor);
12929 // The exception specification is needed because we are defining the
12931 ResolveExceptionSpec(CurrentLocation,
12932 CopyConstructor->getType()->castAs<FunctionProtoType>());
12933 MarkVTableUsed(CurrentLocation, ClassDecl);
12935 // Add a context note for diagnostics produced after this point.
12936 Scope.addContextNote(CurrentLocation);
12938 // C++11 [class.copy]p7:
12939 // The [definition of an implicitly declared copy constructor] is
12940 // deprecated if the class has a user-declared copy assignment operator
12941 // or a user-declared destructor.
12942 if (getLangOpts().CPlusPlus11 && CopyConstructor->isImplicit())
12943 diagnoseDeprecatedCopyOperation(*this, CopyConstructor);
12945 if (SetCtorInitializers(CopyConstructor, /*AnyErrors=*/false)) {
12946 CopyConstructor->setInvalidDecl();
12948 SourceLocation Loc = CopyConstructor->getEndLoc().isValid()
12949 ? CopyConstructor->getEndLoc()
12950 : CopyConstructor->getLocation();
12951 Sema::CompoundScopeRAII CompoundScope(*this);
12952 CopyConstructor->setBody(
12953 ActOnCompoundStmt(Loc, Loc, None, /*isStmtExpr=*/false).getAs<Stmt>());
12954 CopyConstructor->markUsed(Context);
12957 if (ASTMutationListener *L = getASTMutationListener()) {
12958 L->CompletedImplicitDefinition(CopyConstructor);
12962 CXXConstructorDecl *Sema::DeclareImplicitMoveConstructor(
12963 CXXRecordDecl *ClassDecl) {
12964 assert(ClassDecl->needsImplicitMoveConstructor());
12966 DeclaringSpecialMember DSM(*this, ClassDecl, CXXMoveConstructor);
12967 if (DSM.isAlreadyBeingDeclared())
12970 QualType ClassType = Context.getTypeDeclType(ClassDecl);
12972 QualType ArgType = ClassType;
12973 if (Context.getLangOpts().OpenCLCPlusPlus)
12974 ArgType = Context.getAddrSpaceQualType(ClassType, LangAS::opencl_generic);
12975 ArgType = Context.getRValueReferenceType(ArgType);
12977 bool Constexpr = defaultedSpecialMemberIsConstexpr(*this, ClassDecl,
12978 CXXMoveConstructor,
12981 DeclarationName Name
12982 = Context.DeclarationNames.getCXXConstructorName(
12983 Context.getCanonicalType(ClassType));
12984 SourceLocation ClassLoc = ClassDecl->getLocation();
12985 DeclarationNameInfo NameInfo(Name, ClassLoc);
12987 // C++11 [class.copy]p11:
12988 // An implicitly-declared copy/move constructor is an inline public
12989 // member of its class.
12990 CXXConstructorDecl *MoveConstructor = CXXConstructorDecl::Create(
12991 Context, ClassDecl, ClassLoc, NameInfo, QualType(), /*TInfo=*/nullptr,
12992 ExplicitSpecifier(),
12994 /*isImplicitlyDeclared=*/true,
12995 Constexpr ? CSK_constexpr : CSK_unspecified);
12996 MoveConstructor->setAccess(AS_public);
12997 MoveConstructor->setDefaulted();
12999 if (getLangOpts().CUDA) {
13000 inferCUDATargetForImplicitSpecialMember(ClassDecl, CXXMoveConstructor,
13002 /* ConstRHS */ false,
13003 /* Diagnose */ false);
13006 setupImplicitSpecialMemberType(MoveConstructor, Context.VoidTy, ArgType);
13008 // Add the parameter to the constructor.
13009 ParmVarDecl *FromParam = ParmVarDecl::Create(Context, MoveConstructor,
13010 ClassLoc, ClassLoc,
13011 /*IdentifierInfo=*/nullptr,
13012 ArgType, /*TInfo=*/nullptr,
13014 MoveConstructor->setParams(FromParam);
13016 MoveConstructor->setTrivial(
13017 ClassDecl->needsOverloadResolutionForMoveConstructor()
13018 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor)
13019 : ClassDecl->hasTrivialMoveConstructor());
13021 MoveConstructor->setTrivialForCall(
13022 ClassDecl->hasAttr<TrivialABIAttr>() ||
13023 (ClassDecl->needsOverloadResolutionForMoveConstructor()
13024 ? SpecialMemberIsTrivial(MoveConstructor, CXXMoveConstructor,
13025 TAH_ConsiderTrivialABI)
13026 : ClassDecl->hasTrivialMoveConstructorForCall()));
13028 // Note that we have declared this constructor.
13029 ++getASTContext().NumImplicitMoveConstructorsDeclared;
13031 Scope *S = getScopeForContext(ClassDecl);
13032 CheckImplicitSpecialMemberDeclaration(S, MoveConstructor);
13034 if (ShouldDeleteSpecialMember(MoveConstructor, CXXMoveConstructor)) {
13035 ClassDecl->setImplicitMoveConstructorIsDeleted();
13036 SetDeclDeleted(MoveConstructor, ClassLoc);
13040 PushOnScopeChains(MoveConstructor, S, false);
13041 ClassDecl->addDecl(MoveConstructor);
13043 return MoveConstructor;
13046 void Sema::DefineImplicitMoveConstructor(SourceLocation CurrentLocation,
13047 CXXConstructorDecl *MoveConstructor) {
13048 assert((MoveConstructor->isDefaulted() &&
13049 MoveConstructor->isMoveConstructor() &&
13050 !MoveConstructor->doesThisDeclarationHaveABody() &&
13051 !MoveConstructor->isDeleted()) &&
13052 "DefineImplicitMoveConstructor - call it for implicit move ctor");
13053 if (MoveConstructor->willHaveBody() || MoveConstructor->isInvalidDecl())
13056 CXXRecordDecl *ClassDecl = MoveConstructor->getParent();
13057 assert(ClassDecl && "DefineImplicitMoveConstructor - invalid constructor");
13059 SynthesizedFunctionScope Scope(*this, MoveConstructor);
13061 // The exception specification is needed because we are defining the
13063 ResolveExceptionSpec(CurrentLocation,
13064 MoveConstructor->getType()->castAs<FunctionProtoType>());
13065 MarkVTableUsed(CurrentLocation, ClassDecl);
13067 // Add a context note for diagnostics produced after this point.
13068 Scope.addContextNote(CurrentLocation);
13070 if (SetCtorInitializers(MoveConstructor, /*AnyErrors=*/false)) {
13071 MoveConstructor->setInvalidDecl();
13073 SourceLocation Loc = MoveConstructor->getEndLoc().isValid()
13074 ? MoveConstructor->getEndLoc()
13075 : MoveConstructor->getLocation();
13076 Sema::CompoundScopeRAII CompoundScope(*this);
13077 MoveConstructor->setBody(ActOnCompoundStmt(
13078 Loc, Loc, None, /*isStmtExpr=*/ false).getAs<Stmt>());
13079 MoveConstructor->markUsed(Context);
13082 if (ASTMutationListener *L = getASTMutationListener()) {
13083 L->CompletedImplicitDefinition(MoveConstructor);
13087 bool Sema::isImplicitlyDeleted(FunctionDecl *FD) {
13088 return FD->isDeleted() && FD->isDefaulted() && isa<CXXMethodDecl>(FD);
13091 void Sema::DefineImplicitLambdaToFunctionPointerConversion(
13092 SourceLocation CurrentLocation,
13093 CXXConversionDecl *Conv) {
13094 SynthesizedFunctionScope Scope(*this, Conv);
13095 assert(!Conv->getReturnType()->isUndeducedType());
13097 CXXRecordDecl *Lambda = Conv->getParent();
13098 FunctionDecl *CallOp = Lambda->getLambdaCallOperator();
13099 FunctionDecl *Invoker = Lambda->getLambdaStaticInvoker();
13101 if (auto *TemplateArgs = Conv->getTemplateSpecializationArgs()) {
13102 CallOp = InstantiateFunctionDeclaration(
13103 CallOp->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
13107 Invoker = InstantiateFunctionDeclaration(
13108 Invoker->getDescribedFunctionTemplate(), TemplateArgs, CurrentLocation);
13113 if (CallOp->isInvalidDecl())
13116 // Mark the call operator referenced (and add to pending instantiations
13118 // For both the conversion and static-invoker template specializations
13119 // we construct their body's in this function, so no need to add them
13120 // to the PendingInstantiations.
13121 MarkFunctionReferenced(CurrentLocation, CallOp);
13123 // Fill in the __invoke function with a dummy implementation. IR generation
13124 // will fill in the actual details. Update its type in case it contained
13126 Invoker->markUsed(Context);
13127 Invoker->setReferenced();
13128 Invoker->setType(Conv->getReturnType()->getPointeeType());
13129 Invoker->setBody(new (Context) CompoundStmt(Conv->getLocation()));
13131 // Construct the body of the conversion function { return __invoke; }.
13132 Expr *FunctionRef = BuildDeclRefExpr(Invoker, Invoker->getType(),
13133 VK_LValue, Conv->getLocation());
13134 assert(FunctionRef && "Can't refer to __invoke function?");
13135 Stmt *Return = BuildReturnStmt(Conv->getLocation(), FunctionRef).get();
13136 Conv->setBody(CompoundStmt::Create(Context, Return, Conv->getLocation(),
13137 Conv->getLocation()));
13138 Conv->markUsed(Context);
13139 Conv->setReferenced();
13141 if (ASTMutationListener *L = getASTMutationListener()) {
13142 L->CompletedImplicitDefinition(Conv);
13143 L->CompletedImplicitDefinition(Invoker);
13149 void Sema::DefineImplicitLambdaToBlockPointerConversion(
13150 SourceLocation CurrentLocation,
13151 CXXConversionDecl *Conv)
13153 assert(!Conv->getParent()->isGenericLambda());
13155 SynthesizedFunctionScope Scope(*this, Conv);
13157 // Copy-initialize the lambda object as needed to capture it.
13158 Expr *This = ActOnCXXThis(CurrentLocation).get();
13159 Expr *DerefThis =CreateBuiltinUnaryOp(CurrentLocation, UO_Deref, This).get();
13161 ExprResult BuildBlock = BuildBlockForLambdaConversion(CurrentLocation,
13162 Conv->getLocation(),
13165 // If we're not under ARC, make sure we still get the _Block_copy/autorelease
13166 // behavior. Note that only the general conversion function does this
13167 // (since it's unusable otherwise); in the case where we inline the
13168 // block literal, it has block literal lifetime semantics.
13169 if (!BuildBlock.isInvalid() && !getLangOpts().ObjCAutoRefCount)
13170 BuildBlock = ImplicitCastExpr::Create(Context, BuildBlock.get()->getType(),
13171 CK_CopyAndAutoreleaseBlockObject,
13172 BuildBlock.get(), nullptr, VK_RValue);
13174 if (BuildBlock.isInvalid()) {
13175 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
13176 Conv->setInvalidDecl();
13180 // Create the return statement that returns the block from the conversion
13182 StmtResult Return = BuildReturnStmt(Conv->getLocation(), BuildBlock.get());
13183 if (Return.isInvalid()) {
13184 Diag(CurrentLocation, diag::note_lambda_to_block_conv);
13185 Conv->setInvalidDecl();
13189 // Set the body of the conversion function.
13190 Stmt *ReturnS = Return.get();
13191 Conv->setBody(CompoundStmt::Create(Context, ReturnS, Conv->getLocation(),
13192 Conv->getLocation()));
13193 Conv->markUsed(Context);
13195 // We're done; notify the mutation listener, if any.
13196 if (ASTMutationListener *L = getASTMutationListener()) {
13197 L->CompletedImplicitDefinition(Conv);
13201 /// Determine whether the given list arguments contains exactly one
13202 /// "real" (non-default) argument.
13203 static bool hasOneRealArgument(MultiExprArg Args) {
13204 switch (Args.size()) {
13209 if (!Args[1]->isDefaultArgument())
13214 return !Args[0]->isDefaultArgument();
13221 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
13222 NamedDecl *FoundDecl,
13223 CXXConstructorDecl *Constructor,
13224 MultiExprArg ExprArgs,
13225 bool HadMultipleCandidates,
13226 bool IsListInitialization,
13227 bool IsStdInitListInitialization,
13228 bool RequiresZeroInit,
13229 unsigned ConstructKind,
13230 SourceRange ParenRange) {
13231 bool Elidable = false;
13233 // C++0x [class.copy]p34:
13234 // When certain criteria are met, an implementation is allowed to
13235 // omit the copy/move construction of a class object, even if the
13236 // copy/move constructor and/or destructor for the object have
13237 // side effects. [...]
13238 // - when a temporary class object that has not been bound to a
13239 // reference (12.2) would be copied/moved to a class object
13240 // with the same cv-unqualified type, the copy/move operation
13241 // can be omitted by constructing the temporary object
13242 // directly into the target of the omitted copy/move
13243 if (ConstructKind == CXXConstructExpr::CK_Complete && Constructor &&
13244 Constructor->isCopyOrMoveConstructor() && hasOneRealArgument(ExprArgs)) {
13245 Expr *SubExpr = ExprArgs[0];
13246 Elidable = SubExpr->isTemporaryObject(
13247 Context, cast<CXXRecordDecl>(FoundDecl->getDeclContext()));
13250 return BuildCXXConstructExpr(ConstructLoc, DeclInitType,
13251 FoundDecl, Constructor,
13252 Elidable, ExprArgs, HadMultipleCandidates,
13253 IsListInitialization,
13254 IsStdInitListInitialization, RequiresZeroInit,
13255 ConstructKind, ParenRange);
13259 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
13260 NamedDecl *FoundDecl,
13261 CXXConstructorDecl *Constructor,
13263 MultiExprArg ExprArgs,
13264 bool HadMultipleCandidates,
13265 bool IsListInitialization,
13266 bool IsStdInitListInitialization,
13267 bool RequiresZeroInit,
13268 unsigned ConstructKind,
13269 SourceRange ParenRange) {
13270 if (auto *Shadow = dyn_cast<ConstructorUsingShadowDecl>(FoundDecl)) {
13271 Constructor = findInheritingConstructor(ConstructLoc, Constructor, Shadow);
13272 if (DiagnoseUseOfDecl(Constructor, ConstructLoc))
13273 return ExprError();
13276 return BuildCXXConstructExpr(
13277 ConstructLoc, DeclInitType, Constructor, Elidable, ExprArgs,
13278 HadMultipleCandidates, IsListInitialization, IsStdInitListInitialization,
13279 RequiresZeroInit, ConstructKind, ParenRange);
13282 /// BuildCXXConstructExpr - Creates a complete call to a constructor,
13283 /// including handling of its default argument expressions.
13285 Sema::BuildCXXConstructExpr(SourceLocation ConstructLoc, QualType DeclInitType,
13286 CXXConstructorDecl *Constructor,
13288 MultiExprArg ExprArgs,
13289 bool HadMultipleCandidates,
13290 bool IsListInitialization,
13291 bool IsStdInitListInitialization,
13292 bool RequiresZeroInit,
13293 unsigned ConstructKind,
13294 SourceRange ParenRange) {
13295 assert(declaresSameEntity(
13296 Constructor->getParent(),
13297 DeclInitType->getBaseElementTypeUnsafe()->getAsCXXRecordDecl()) &&
13298 "given constructor for wrong type");
13299 MarkFunctionReferenced(ConstructLoc, Constructor);
13300 if (getLangOpts().CUDA && !CheckCUDACall(ConstructLoc, Constructor))
13301 return ExprError();
13303 return CXXConstructExpr::Create(
13304 Context, DeclInitType, ConstructLoc, Constructor, Elidable,
13305 ExprArgs, HadMultipleCandidates, IsListInitialization,
13306 IsStdInitListInitialization, RequiresZeroInit,
13307 static_cast<CXXConstructExpr::ConstructionKind>(ConstructKind),
13311 ExprResult Sema::BuildCXXDefaultInitExpr(SourceLocation Loc, FieldDecl *Field) {
13312 assert(Field->hasInClassInitializer());
13314 // If we already have the in-class initializer nothing needs to be done.
13315 if (Field->getInClassInitializer())
13316 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
13318 // If we might have already tried and failed to instantiate, don't try again.
13319 if (Field->isInvalidDecl())
13320 return ExprError();
13322 // Maybe we haven't instantiated the in-class initializer. Go check the
13323 // pattern FieldDecl to see if it has one.
13324 CXXRecordDecl *ParentRD = cast<CXXRecordDecl>(Field->getParent());
13326 if (isTemplateInstantiation(ParentRD->getTemplateSpecializationKind())) {
13327 CXXRecordDecl *ClassPattern = ParentRD->getTemplateInstantiationPattern();
13328 DeclContext::lookup_result Lookup =
13329 ClassPattern->lookup(Field->getDeclName());
13331 // Lookup can return at most two results: the pattern for the field, or the
13332 // injected class name of the parent record. No other member can have the
13333 // same name as the field.
13334 // In modules mode, lookup can return multiple results (coming from
13335 // different modules).
13336 assert((getLangOpts().Modules || (!Lookup.empty() && Lookup.size() <= 2)) &&
13337 "more than two lookup results for field name");
13338 FieldDecl *Pattern = dyn_cast<FieldDecl>(Lookup[0]);
13340 assert(isa<CXXRecordDecl>(Lookup[0]) &&
13341 "cannot have other non-field member with same name");
13342 for (auto L : Lookup)
13343 if (isa<FieldDecl>(L)) {
13344 Pattern = cast<FieldDecl>(L);
13347 assert(Pattern && "We must have set the Pattern!");
13350 if (!Pattern->hasInClassInitializer() ||
13351 InstantiateInClassInitializer(Loc, Field, Pattern,
13352 getTemplateInstantiationArgs(Field))) {
13353 // Don't diagnose this again.
13354 Field->setInvalidDecl();
13355 return ExprError();
13357 return CXXDefaultInitExpr::Create(Context, Loc, Field, CurContext);
13361 // If the brace-or-equal-initializer of a non-static data member
13362 // invokes a defaulted default constructor of its class or of an
13363 // enclosing class in a potentially evaluated subexpression, the
13364 // program is ill-formed.
13366 // This resolution is unworkable: the exception specification of the
13367 // default constructor can be needed in an unevaluated context, in
13368 // particular, in the operand of a noexcept-expression, and we can be
13369 // unable to compute an exception specification for an enclosed class.
13371 // Any attempt to resolve the exception specification of a defaulted default
13372 // constructor before the initializer is lexically complete will ultimately
13373 // come here at which point we can diagnose it.
13374 RecordDecl *OutermostClass = ParentRD->getOuterLexicalRecordContext();
13375 Diag(Loc, diag::err_in_class_initializer_not_yet_parsed)
13376 << OutermostClass << Field;
13377 Diag(Field->getEndLoc(), diag::note_in_class_initializer_not_yet_parsed);
13378 // Recover by marking the field invalid, unless we're in a SFINAE context.
13379 if (!isSFINAEContext())
13380 Field->setInvalidDecl();
13381 return ExprError();
13384 void Sema::FinalizeVarWithDestructor(VarDecl *VD, const RecordType *Record) {
13385 if (VD->isInvalidDecl()) return;
13387 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Record->getDecl());
13388 if (ClassDecl->isInvalidDecl()) return;
13389 if (ClassDecl->hasIrrelevantDestructor()) return;
13390 if (ClassDecl->isDependentContext()) return;
13392 if (VD->isNoDestroy(getASTContext()))
13395 CXXDestructorDecl *Destructor = LookupDestructor(ClassDecl);
13397 // If this is an array, we'll require the destructor during initialization, so
13398 // we can skip over this. We still want to emit exit-time destructor warnings
13400 if (!VD->getType()->isArrayType()) {
13401 MarkFunctionReferenced(VD->getLocation(), Destructor);
13402 CheckDestructorAccess(VD->getLocation(), Destructor,
13403 PDiag(diag::err_access_dtor_var)
13404 << VD->getDeclName() << VD->getType());
13405 DiagnoseUseOfDecl(Destructor, VD->getLocation());
13408 if (Destructor->isTrivial()) return;
13410 // If the destructor is constexpr, check whether the variable has constant
13411 // destruction now.
13412 if (Destructor->isConstexpr() && VD->getInit() &&
13413 !VD->getInit()->isValueDependent() && VD->evaluateValue()) {
13414 SmallVector<PartialDiagnosticAt, 8> Notes;
13415 if (!VD->evaluateDestruction(Notes) && VD->isConstexpr()) {
13416 Diag(VD->getLocation(),
13417 diag::err_constexpr_var_requires_const_destruction) << VD;
13418 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
13419 Diag(Notes[I].first, Notes[I].second);
13423 if (!VD->hasGlobalStorage()) return;
13425 // Emit warning for non-trivial dtor in global scope (a real global,
13426 // class-static, function-static).
13427 Diag(VD->getLocation(), diag::warn_exit_time_destructor);
13429 // TODO: this should be re-enabled for static locals by !CXAAtExit
13430 if (!VD->isStaticLocal())
13431 Diag(VD->getLocation(), diag::warn_global_destructor);
13434 /// Given a constructor and the set of arguments provided for the
13435 /// constructor, convert the arguments and add any required default arguments
13436 /// to form a proper call to this constructor.
13438 /// \returns true if an error occurred, false otherwise.
13440 Sema::CompleteConstructorCall(CXXConstructorDecl *Constructor,
13441 MultiExprArg ArgsPtr,
13442 SourceLocation Loc,
13443 SmallVectorImpl<Expr*> &ConvertedArgs,
13444 bool AllowExplicit,
13445 bool IsListInitialization) {
13446 // FIXME: This duplicates a lot of code from Sema::ConvertArgumentsForCall.
13447 unsigned NumArgs = ArgsPtr.size();
13448 Expr **Args = ArgsPtr.data();
13450 const FunctionProtoType *Proto
13451 = Constructor->getType()->getAs<FunctionProtoType>();
13452 assert(Proto && "Constructor without a prototype?");
13453 unsigned NumParams = Proto->getNumParams();
13455 // If too few arguments are available, we'll fill in the rest with defaults.
13456 if (NumArgs < NumParams)
13457 ConvertedArgs.reserve(NumParams);
13459 ConvertedArgs.reserve(NumArgs);
13461 VariadicCallType CallType =
13462 Proto->isVariadic() ? VariadicConstructor : VariadicDoesNotApply;
13463 SmallVector<Expr *, 8> AllArgs;
13464 bool Invalid = GatherArgumentsForCall(Loc, Constructor,
13466 llvm::makeArrayRef(Args, NumArgs),
13468 CallType, AllowExplicit,
13469 IsListInitialization);
13470 ConvertedArgs.append(AllArgs.begin(), AllArgs.end());
13472 DiagnoseSentinelCalls(Constructor, Loc, AllArgs);
13474 CheckConstructorCall(Constructor,
13475 llvm::makeArrayRef(AllArgs.data(), AllArgs.size()),
13482 CheckOperatorNewDeleteDeclarationScope(Sema &SemaRef,
13483 const FunctionDecl *FnDecl) {
13484 const DeclContext *DC = FnDecl->getDeclContext()->getRedeclContext();
13485 if (isa<NamespaceDecl>(DC)) {
13486 return SemaRef.Diag(FnDecl->getLocation(),
13487 diag::err_operator_new_delete_declared_in_namespace)
13488 << FnDecl->getDeclName();
13491 if (isa<TranslationUnitDecl>(DC) &&
13492 FnDecl->getStorageClass() == SC_Static) {
13493 return SemaRef.Diag(FnDecl->getLocation(),
13494 diag::err_operator_new_delete_declared_static)
13495 << FnDecl->getDeclName();
13502 RemoveAddressSpaceFromPtr(Sema &SemaRef, const PointerType *PtrTy) {
13503 QualType QTy = PtrTy->getPointeeType();
13504 QTy = SemaRef.Context.removeAddrSpaceQualType(QTy);
13505 return SemaRef.Context.getPointerType(QTy);
13509 CheckOperatorNewDeleteTypes(Sema &SemaRef, const FunctionDecl *FnDecl,
13510 CanQualType ExpectedResultType,
13511 CanQualType ExpectedFirstParamType,
13512 unsigned DependentParamTypeDiag,
13513 unsigned InvalidParamTypeDiag) {
13514 QualType ResultType =
13515 FnDecl->getType()->getAs<FunctionType>()->getReturnType();
13517 // Check that the result type is not dependent.
13518 if (ResultType->isDependentType())
13519 return SemaRef.Diag(FnDecl->getLocation(),
13520 diag::err_operator_new_delete_dependent_result_type)
13521 << FnDecl->getDeclName() << ExpectedResultType;
13523 // The operator is valid on any address space for OpenCL.
13524 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
13525 if (auto *PtrTy = ResultType->getAs<PointerType>()) {
13526 ResultType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
13530 // Check that the result type is what we expect.
13531 if (SemaRef.Context.getCanonicalType(ResultType) != ExpectedResultType)
13532 return SemaRef.Diag(FnDecl->getLocation(),
13533 diag::err_operator_new_delete_invalid_result_type)
13534 << FnDecl->getDeclName() << ExpectedResultType;
13536 // A function template must have at least 2 parameters.
13537 if (FnDecl->getDescribedFunctionTemplate() && FnDecl->getNumParams() < 2)
13538 return SemaRef.Diag(FnDecl->getLocation(),
13539 diag::err_operator_new_delete_template_too_few_parameters)
13540 << FnDecl->getDeclName();
13542 // The function decl must have at least 1 parameter.
13543 if (FnDecl->getNumParams() == 0)
13544 return SemaRef.Diag(FnDecl->getLocation(),
13545 diag::err_operator_new_delete_too_few_parameters)
13546 << FnDecl->getDeclName();
13548 // Check the first parameter type is not dependent.
13549 QualType FirstParamType = FnDecl->getParamDecl(0)->getType();
13550 if (FirstParamType->isDependentType())
13551 return SemaRef.Diag(FnDecl->getLocation(), DependentParamTypeDiag)
13552 << FnDecl->getDeclName() << ExpectedFirstParamType;
13554 // Check that the first parameter type is what we expect.
13555 if (SemaRef.getLangOpts().OpenCLCPlusPlus) {
13556 // The operator is valid on any address space for OpenCL.
13558 FnDecl->getParamDecl(0)->getType()->getAs<PointerType>()) {
13559 FirstParamType = RemoveAddressSpaceFromPtr(SemaRef, PtrTy);
13562 if (SemaRef.Context.getCanonicalType(FirstParamType).getUnqualifiedType() !=
13563 ExpectedFirstParamType)
13564 return SemaRef.Diag(FnDecl->getLocation(), InvalidParamTypeDiag)
13565 << FnDecl->getDeclName() << ExpectedFirstParamType;
13571 CheckOperatorNewDeclaration(Sema &SemaRef, const FunctionDecl *FnDecl) {
13572 // C++ [basic.stc.dynamic.allocation]p1:
13573 // A program is ill-formed if an allocation function is declared in a
13574 // namespace scope other than global scope or declared static in global
13576 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
13579 CanQualType SizeTy =
13580 SemaRef.Context.getCanonicalType(SemaRef.Context.getSizeType());
13582 // C++ [basic.stc.dynamic.allocation]p1:
13583 // The return type shall be void*. The first parameter shall have type
13585 if (CheckOperatorNewDeleteTypes(SemaRef, FnDecl, SemaRef.Context.VoidPtrTy,
13587 diag::err_operator_new_dependent_param_type,
13588 diag::err_operator_new_param_type))
13591 // C++ [basic.stc.dynamic.allocation]p1:
13592 // The first parameter shall not have an associated default argument.
13593 if (FnDecl->getParamDecl(0)->hasDefaultArg())
13594 return SemaRef.Diag(FnDecl->getLocation(),
13595 diag::err_operator_new_default_arg)
13596 << FnDecl->getDeclName() << FnDecl->getParamDecl(0)->getDefaultArgRange();
13602 CheckOperatorDeleteDeclaration(Sema &SemaRef, FunctionDecl *FnDecl) {
13603 // C++ [basic.stc.dynamic.deallocation]p1:
13604 // A program is ill-formed if deallocation functions are declared in a
13605 // namespace scope other than global scope or declared static in global
13607 if (CheckOperatorNewDeleteDeclarationScope(SemaRef, FnDecl))
13610 auto *MD = dyn_cast<CXXMethodDecl>(FnDecl);
13613 // Within a class C, the first parameter of a destroying operator delete
13614 // shall be of type C *. The first parameter of any other deallocation
13615 // function shall be of type void *.
13616 CanQualType ExpectedFirstParamType =
13617 MD && MD->isDestroyingOperatorDelete()
13618 ? SemaRef.Context.getCanonicalType(SemaRef.Context.getPointerType(
13619 SemaRef.Context.getRecordType(MD->getParent())))
13620 : SemaRef.Context.VoidPtrTy;
13622 // C++ [basic.stc.dynamic.deallocation]p2:
13623 // Each deallocation function shall return void
13624 if (CheckOperatorNewDeleteTypes(
13625 SemaRef, FnDecl, SemaRef.Context.VoidTy, ExpectedFirstParamType,
13626 diag::err_operator_delete_dependent_param_type,
13627 diag::err_operator_delete_param_type))
13631 // A destroying operator delete shall be a usual deallocation function.
13632 if (MD && !MD->getParent()->isDependentContext() &&
13633 MD->isDestroyingOperatorDelete() &&
13634 !SemaRef.isUsualDeallocationFunction(MD)) {
13635 SemaRef.Diag(MD->getLocation(),
13636 diag::err_destroying_operator_delete_not_usual);
13643 /// CheckOverloadedOperatorDeclaration - Check whether the declaration
13644 /// of this overloaded operator is well-formed. If so, returns false;
13645 /// otherwise, emits appropriate diagnostics and returns true.
13646 bool Sema::CheckOverloadedOperatorDeclaration(FunctionDecl *FnDecl) {
13647 assert(FnDecl && FnDecl->isOverloadedOperator() &&
13648 "Expected an overloaded operator declaration");
13650 OverloadedOperatorKind Op = FnDecl->getOverloadedOperator();
13652 // C++ [over.oper]p5:
13653 // The allocation and deallocation functions, operator new,
13654 // operator new[], operator delete and operator delete[], are
13655 // described completely in 3.7.3. The attributes and restrictions
13656 // found in the rest of this subclause do not apply to them unless
13657 // explicitly stated in 3.7.3.
13658 if (Op == OO_Delete || Op == OO_Array_Delete)
13659 return CheckOperatorDeleteDeclaration(*this, FnDecl);
13661 if (Op == OO_New || Op == OO_Array_New)
13662 return CheckOperatorNewDeclaration(*this, FnDecl);
13664 // C++ [over.oper]p6:
13665 // An operator function shall either be a non-static member
13666 // function or be a non-member function and have at least one
13667 // parameter whose type is a class, a reference to a class, an
13668 // enumeration, or a reference to an enumeration.
13669 if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(FnDecl)) {
13670 if (MethodDecl->isStatic())
13671 return Diag(FnDecl->getLocation(),
13672 diag::err_operator_overload_static) << FnDecl->getDeclName();
13674 bool ClassOrEnumParam = false;
13675 for (auto Param : FnDecl->parameters()) {
13676 QualType ParamType = Param->getType().getNonReferenceType();
13677 if (ParamType->isDependentType() || ParamType->isRecordType() ||
13678 ParamType->isEnumeralType()) {
13679 ClassOrEnumParam = true;
13684 if (!ClassOrEnumParam)
13685 return Diag(FnDecl->getLocation(),
13686 diag::err_operator_overload_needs_class_or_enum)
13687 << FnDecl->getDeclName();
13690 // C++ [over.oper]p8:
13691 // An operator function cannot have default arguments (8.3.6),
13692 // except where explicitly stated below.
13694 // Only the function-call operator allows default arguments
13695 // (C++ [over.call]p1).
13696 if (Op != OO_Call) {
13697 for (auto Param : FnDecl->parameters()) {
13698 if (Param->hasDefaultArg())
13699 return Diag(Param->getLocation(),
13700 diag::err_operator_overload_default_arg)
13701 << FnDecl->getDeclName() << Param->getDefaultArgRange();
13705 static const bool OperatorUses[NUM_OVERLOADED_OPERATORS][3] = {
13706 { false, false, false }
13707 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
13708 , { Unary, Binary, MemberOnly }
13709 #include "clang/Basic/OperatorKinds.def"
13712 bool CanBeUnaryOperator = OperatorUses[Op][0];
13713 bool CanBeBinaryOperator = OperatorUses[Op][1];
13714 bool MustBeMemberOperator = OperatorUses[Op][2];
13716 // C++ [over.oper]p8:
13717 // [...] Operator functions cannot have more or fewer parameters
13718 // than the number required for the corresponding operator, as
13719 // described in the rest of this subclause.
13720 unsigned NumParams = FnDecl->getNumParams()
13721 + (isa<CXXMethodDecl>(FnDecl)? 1 : 0);
13722 if (Op != OO_Call &&
13723 ((NumParams == 1 && !CanBeUnaryOperator) ||
13724 (NumParams == 2 && !CanBeBinaryOperator) ||
13725 (NumParams < 1) || (NumParams > 2))) {
13726 // We have the wrong number of parameters.
13727 unsigned ErrorKind;
13728 if (CanBeUnaryOperator && CanBeBinaryOperator) {
13729 ErrorKind = 2; // 2 -> unary or binary.
13730 } else if (CanBeUnaryOperator) {
13731 ErrorKind = 0; // 0 -> unary
13733 assert(CanBeBinaryOperator &&
13734 "All non-call overloaded operators are unary or binary!");
13735 ErrorKind = 1; // 1 -> binary
13738 return Diag(FnDecl->getLocation(), diag::err_operator_overload_must_be)
13739 << FnDecl->getDeclName() << NumParams << ErrorKind;
13742 // Overloaded operators other than operator() cannot be variadic.
13743 if (Op != OO_Call &&
13744 FnDecl->getType()->getAs<FunctionProtoType>()->isVariadic()) {
13745 return Diag(FnDecl->getLocation(), diag::err_operator_overload_variadic)
13746 << FnDecl->getDeclName();
13749 // Some operators must be non-static member functions.
13750 if (MustBeMemberOperator && !isa<CXXMethodDecl>(FnDecl)) {
13751 return Diag(FnDecl->getLocation(),
13752 diag::err_operator_overload_must_be_member)
13753 << FnDecl->getDeclName();
13756 // C++ [over.inc]p1:
13757 // The user-defined function called operator++ implements the
13758 // prefix and postfix ++ operator. If this function is a member
13759 // function with no parameters, or a non-member function with one
13760 // parameter of class or enumeration type, it defines the prefix
13761 // increment operator ++ for objects of that type. If the function
13762 // is a member function with one parameter (which shall be of type
13763 // int) or a non-member function with two parameters (the second
13764 // of which shall be of type int), it defines the postfix
13765 // increment operator ++ for objects of that type.
13766 if ((Op == OO_PlusPlus || Op == OO_MinusMinus) && NumParams == 2) {
13767 ParmVarDecl *LastParam = FnDecl->getParamDecl(FnDecl->getNumParams() - 1);
13768 QualType ParamType = LastParam->getType();
13770 if (!ParamType->isSpecificBuiltinType(BuiltinType::Int) &&
13771 !ParamType->isDependentType())
13772 return Diag(LastParam->getLocation(),
13773 diag::err_operator_overload_post_incdec_must_be_int)
13774 << LastParam->getType() << (Op == OO_MinusMinus);
13781 checkLiteralOperatorTemplateParameterList(Sema &SemaRef,
13782 FunctionTemplateDecl *TpDecl) {
13783 TemplateParameterList *TemplateParams = TpDecl->getTemplateParameters();
13785 // Must have one or two template parameters.
13786 if (TemplateParams->size() == 1) {
13787 NonTypeTemplateParmDecl *PmDecl =
13788 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(0));
13790 // The template parameter must be a char parameter pack.
13791 if (PmDecl && PmDecl->isTemplateParameterPack() &&
13792 SemaRef.Context.hasSameType(PmDecl->getType(), SemaRef.Context.CharTy))
13795 } else if (TemplateParams->size() == 2) {
13796 TemplateTypeParmDecl *PmType =
13797 dyn_cast<TemplateTypeParmDecl>(TemplateParams->getParam(0));
13798 NonTypeTemplateParmDecl *PmArgs =
13799 dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(1));
13801 // The second template parameter must be a parameter pack with the
13802 // first template parameter as its type.
13803 if (PmType && PmArgs && !PmType->isTemplateParameterPack() &&
13804 PmArgs->isTemplateParameterPack()) {
13805 const TemplateTypeParmType *TArgs =
13806 PmArgs->getType()->getAs<TemplateTypeParmType>();
13807 if (TArgs && TArgs->getDepth() == PmType->getDepth() &&
13808 TArgs->getIndex() == PmType->getIndex()) {
13809 if (!SemaRef.inTemplateInstantiation())
13810 SemaRef.Diag(TpDecl->getLocation(),
13811 diag::ext_string_literal_operator_template);
13817 SemaRef.Diag(TpDecl->getTemplateParameters()->getSourceRange().getBegin(),
13818 diag::err_literal_operator_template)
13819 << TpDecl->getTemplateParameters()->getSourceRange();
13823 /// CheckLiteralOperatorDeclaration - Check whether the declaration
13824 /// of this literal operator function is well-formed. If so, returns
13825 /// false; otherwise, emits appropriate diagnostics and returns true.
13826 bool Sema::CheckLiteralOperatorDeclaration(FunctionDecl *FnDecl) {
13827 if (isa<CXXMethodDecl>(FnDecl)) {
13828 Diag(FnDecl->getLocation(), diag::err_literal_operator_outside_namespace)
13829 << FnDecl->getDeclName();
13833 if (FnDecl->isExternC()) {
13834 Diag(FnDecl->getLocation(), diag::err_literal_operator_extern_c);
13835 if (const LinkageSpecDecl *LSD =
13836 FnDecl->getDeclContext()->getExternCContext())
13837 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
13841 // This might be the definition of a literal operator template.
13842 FunctionTemplateDecl *TpDecl = FnDecl->getDescribedFunctionTemplate();
13844 // This might be a specialization of a literal operator template.
13846 TpDecl = FnDecl->getPrimaryTemplate();
13848 // template <char...> type operator "" name() and
13849 // template <class T, T...> type operator "" name() are the only valid
13850 // template signatures, and the only valid signatures with no parameters.
13852 if (FnDecl->param_size() != 0) {
13853 Diag(FnDecl->getLocation(),
13854 diag::err_literal_operator_template_with_params);
13858 if (checkLiteralOperatorTemplateParameterList(*this, TpDecl))
13861 } else if (FnDecl->param_size() == 1) {
13862 const ParmVarDecl *Param = FnDecl->getParamDecl(0);
13864 QualType ParamType = Param->getType().getUnqualifiedType();
13866 // Only unsigned long long int, long double, any character type, and const
13867 // char * are allowed as the only parameters.
13868 if (ParamType->isSpecificBuiltinType(BuiltinType::ULongLong) ||
13869 ParamType->isSpecificBuiltinType(BuiltinType::LongDouble) ||
13870 Context.hasSameType(ParamType, Context.CharTy) ||
13871 Context.hasSameType(ParamType, Context.WideCharTy) ||
13872 Context.hasSameType(ParamType, Context.Char8Ty) ||
13873 Context.hasSameType(ParamType, Context.Char16Ty) ||
13874 Context.hasSameType(ParamType, Context.Char32Ty)) {
13875 } else if (const PointerType *Ptr = ParamType->getAs<PointerType>()) {
13876 QualType InnerType = Ptr->getPointeeType();
13878 // Pointer parameter must be a const char *.
13879 if (!(Context.hasSameType(InnerType.getUnqualifiedType(),
13881 InnerType.isConstQualified() && !InnerType.isVolatileQualified())) {
13882 Diag(Param->getSourceRange().getBegin(),
13883 diag::err_literal_operator_param)
13884 << ParamType << "'const char *'" << Param->getSourceRange();
13888 } else if (ParamType->isRealFloatingType()) {
13889 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
13890 << ParamType << Context.LongDoubleTy << Param->getSourceRange();
13893 } else if (ParamType->isIntegerType()) {
13894 Diag(Param->getSourceRange().getBegin(), diag::err_literal_operator_param)
13895 << ParamType << Context.UnsignedLongLongTy << Param->getSourceRange();
13899 Diag(Param->getSourceRange().getBegin(),
13900 diag::err_literal_operator_invalid_param)
13901 << ParamType << Param->getSourceRange();
13905 } else if (FnDecl->param_size() == 2) {
13906 FunctionDecl::param_iterator Param = FnDecl->param_begin();
13908 // First, verify that the first parameter is correct.
13910 QualType FirstParamType = (*Param)->getType().getUnqualifiedType();
13912 // Two parameter function must have a pointer to const as a
13913 // first parameter; let's strip those qualifiers.
13914 const PointerType *PT = FirstParamType->getAs<PointerType>();
13917 Diag((*Param)->getSourceRange().getBegin(),
13918 diag::err_literal_operator_param)
13919 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
13923 QualType PointeeType = PT->getPointeeType();
13924 // First parameter must be const
13925 if (!PointeeType.isConstQualified() || PointeeType.isVolatileQualified()) {
13926 Diag((*Param)->getSourceRange().getBegin(),
13927 diag::err_literal_operator_param)
13928 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
13932 QualType InnerType = PointeeType.getUnqualifiedType();
13933 // Only const char *, const wchar_t*, const char8_t*, const char16_t*, and
13934 // const char32_t* are allowed as the first parameter to a two-parameter
13936 if (!(Context.hasSameType(InnerType, Context.CharTy) ||
13937 Context.hasSameType(InnerType, Context.WideCharTy) ||
13938 Context.hasSameType(InnerType, Context.Char8Ty) ||
13939 Context.hasSameType(InnerType, Context.Char16Ty) ||
13940 Context.hasSameType(InnerType, Context.Char32Ty))) {
13941 Diag((*Param)->getSourceRange().getBegin(),
13942 diag::err_literal_operator_param)
13943 << FirstParamType << "'const char *'" << (*Param)->getSourceRange();
13947 // Move on to the second and final parameter.
13950 // The second parameter must be a std::size_t.
13951 QualType SecondParamType = (*Param)->getType().getUnqualifiedType();
13952 if (!Context.hasSameType(SecondParamType, Context.getSizeType())) {
13953 Diag((*Param)->getSourceRange().getBegin(),
13954 diag::err_literal_operator_param)
13955 << SecondParamType << Context.getSizeType()
13956 << (*Param)->getSourceRange();
13960 Diag(FnDecl->getLocation(), diag::err_literal_operator_bad_param_count);
13964 // Parameters are good.
13966 // A parameter-declaration-clause containing a default argument is not
13967 // equivalent to any of the permitted forms.
13968 for (auto Param : FnDecl->parameters()) {
13969 if (Param->hasDefaultArg()) {
13970 Diag(Param->getDefaultArgRange().getBegin(),
13971 diag::err_literal_operator_default_argument)
13972 << Param->getDefaultArgRange();
13977 StringRef LiteralName
13978 = FnDecl->getDeclName().getCXXLiteralIdentifier()->getName();
13979 if (LiteralName[0] != '_' &&
13980 !getSourceManager().isInSystemHeader(FnDecl->getLocation())) {
13981 // C++11 [usrlit.suffix]p1:
13982 // Literal suffix identifiers that do not start with an underscore
13983 // are reserved for future standardization.
13984 Diag(FnDecl->getLocation(), diag::warn_user_literal_reserved)
13985 << StringLiteralParser::isValidUDSuffix(getLangOpts(), LiteralName);
13991 /// ActOnStartLinkageSpecification - Parsed the beginning of a C++
13992 /// linkage specification, including the language and (if present)
13993 /// the '{'. ExternLoc is the location of the 'extern', Lang is the
13994 /// language string literal. LBraceLoc, if valid, provides the location of
13995 /// the '{' brace. Otherwise, this linkage specification does not
13996 /// have any braces.
13997 Decl *Sema::ActOnStartLinkageSpecification(Scope *S, SourceLocation ExternLoc,
13999 SourceLocation LBraceLoc) {
14000 StringLiteral *Lit = cast<StringLiteral>(LangStr);
14001 if (!Lit->isAscii()) {
14002 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_not_ascii)
14003 << LangStr->getSourceRange();
14007 StringRef Lang = Lit->getString();
14008 LinkageSpecDecl::LanguageIDs Language;
14010 Language = LinkageSpecDecl::lang_c;
14011 else if (Lang == "C++")
14012 Language = LinkageSpecDecl::lang_cxx;
14013 else if (Lang == "C++11")
14014 Language = LinkageSpecDecl::lang_cxx_11;
14015 else if (Lang == "C++14")
14016 Language = LinkageSpecDecl::lang_cxx_14;
14018 Diag(LangStr->getExprLoc(), diag::err_language_linkage_spec_unknown)
14019 << LangStr->getSourceRange();
14023 // FIXME: Add all the various semantics of linkage specifications
14025 LinkageSpecDecl *D = LinkageSpecDecl::Create(Context, CurContext, ExternLoc,
14026 LangStr->getExprLoc(), Language,
14027 LBraceLoc.isValid());
14028 CurContext->addDecl(D);
14029 PushDeclContext(S, D);
14033 /// ActOnFinishLinkageSpecification - Complete the definition of
14034 /// the C++ linkage specification LinkageSpec. If RBraceLoc is
14035 /// valid, it's the position of the closing '}' brace in a linkage
14036 /// specification that uses braces.
14037 Decl *Sema::ActOnFinishLinkageSpecification(Scope *S,
14039 SourceLocation RBraceLoc) {
14040 if (RBraceLoc.isValid()) {
14041 LinkageSpecDecl* LSDecl = cast<LinkageSpecDecl>(LinkageSpec);
14042 LSDecl->setRBraceLoc(RBraceLoc);
14045 return LinkageSpec;
14048 Decl *Sema::ActOnEmptyDeclaration(Scope *S,
14049 const ParsedAttributesView &AttrList,
14050 SourceLocation SemiLoc) {
14051 Decl *ED = EmptyDecl::Create(Context, CurContext, SemiLoc);
14052 // Attribute declarations appertain to empty declaration so we handle
14054 ProcessDeclAttributeList(S, ED, AttrList);
14056 CurContext->addDecl(ED);
14060 /// Perform semantic analysis for the variable declaration that
14061 /// occurs within a C++ catch clause, returning the newly-created
14063 VarDecl *Sema::BuildExceptionDeclaration(Scope *S,
14064 TypeSourceInfo *TInfo,
14065 SourceLocation StartLoc,
14066 SourceLocation Loc,
14067 IdentifierInfo *Name) {
14068 bool Invalid = false;
14069 QualType ExDeclType = TInfo->getType();
14071 // Arrays and functions decay.
14072 if (ExDeclType->isArrayType())
14073 ExDeclType = Context.getArrayDecayedType(ExDeclType);
14074 else if (ExDeclType->isFunctionType())
14075 ExDeclType = Context.getPointerType(ExDeclType);
14077 // C++ 15.3p1: The exception-declaration shall not denote an incomplete type.
14078 // The exception-declaration shall not denote a pointer or reference to an
14079 // incomplete type, other than [cv] void*.
14080 // N2844 forbids rvalue references.
14081 if (!ExDeclType->isDependentType() && ExDeclType->isRValueReferenceType()) {
14082 Diag(Loc, diag::err_catch_rvalue_ref);
14086 if (ExDeclType->isVariablyModifiedType()) {
14087 Diag(Loc, diag::err_catch_variably_modified) << ExDeclType;
14091 QualType BaseType = ExDeclType;
14092 int Mode = 0; // 0 for direct type, 1 for pointer, 2 for reference
14093 unsigned DK = diag::err_catch_incomplete;
14094 if (const PointerType *Ptr = BaseType->getAs<PointerType>()) {
14095 BaseType = Ptr->getPointeeType();
14097 DK = diag::err_catch_incomplete_ptr;
14098 } else if (const ReferenceType *Ref = BaseType->getAs<ReferenceType>()) {
14099 // For the purpose of error recovery, we treat rvalue refs like lvalue refs.
14100 BaseType = Ref->getPointeeType();
14102 DK = diag::err_catch_incomplete_ref;
14104 if (!Invalid && (Mode == 0 || !BaseType->isVoidType()) &&
14105 !BaseType->isDependentType() && RequireCompleteType(Loc, BaseType, DK))
14108 if (!Invalid && !ExDeclType->isDependentType() &&
14109 RequireNonAbstractType(Loc, ExDeclType,
14110 diag::err_abstract_type_in_decl,
14111 AbstractVariableType))
14114 // Only the non-fragile NeXT runtime currently supports C++ catches
14115 // of ObjC types, and no runtime supports catching ObjC types by value.
14116 if (!Invalid && getLangOpts().ObjC) {
14117 QualType T = ExDeclType;
14118 if (const ReferenceType *RT = T->getAs<ReferenceType>())
14119 T = RT->getPointeeType();
14121 if (T->isObjCObjectType()) {
14122 Diag(Loc, diag::err_objc_object_catch);
14124 } else if (T->isObjCObjectPointerType()) {
14125 // FIXME: should this be a test for macosx-fragile specifically?
14126 if (getLangOpts().ObjCRuntime.isFragile())
14127 Diag(Loc, diag::warn_objc_pointer_cxx_catch_fragile);
14131 VarDecl *ExDecl = VarDecl::Create(Context, CurContext, StartLoc, Loc, Name,
14132 ExDeclType, TInfo, SC_None);
14133 ExDecl->setExceptionVariable(true);
14135 // In ARC, infer 'retaining' for variables of retainable type.
14136 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(ExDecl))
14139 if (!Invalid && !ExDeclType->isDependentType()) {
14140 if (const RecordType *recordType = ExDeclType->getAs<RecordType>()) {
14141 // Insulate this from anything else we might currently be parsing.
14142 EnterExpressionEvaluationContext scope(
14143 *this, ExpressionEvaluationContext::PotentiallyEvaluated);
14145 // C++ [except.handle]p16:
14146 // The object declared in an exception-declaration or, if the
14147 // exception-declaration does not specify a name, a temporary (12.2) is
14148 // copy-initialized (8.5) from the exception object. [...]
14149 // The object is destroyed when the handler exits, after the destruction
14150 // of any automatic objects initialized within the handler.
14152 // We just pretend to initialize the object with itself, then make sure
14153 // it can be destroyed later.
14154 QualType initType = Context.getExceptionObjectType(ExDeclType);
14156 InitializedEntity entity =
14157 InitializedEntity::InitializeVariable(ExDecl);
14158 InitializationKind initKind =
14159 InitializationKind::CreateCopy(Loc, SourceLocation());
14161 Expr *opaqueValue =
14162 new (Context) OpaqueValueExpr(Loc, initType, VK_LValue, OK_Ordinary);
14163 InitializationSequence sequence(*this, entity, initKind, opaqueValue);
14164 ExprResult result = sequence.Perform(*this, entity, initKind, opaqueValue);
14165 if (result.isInvalid())
14168 // If the constructor used was non-trivial, set this as the
14170 CXXConstructExpr *construct = result.getAs<CXXConstructExpr>();
14171 if (!construct->getConstructor()->isTrivial()) {
14172 Expr *init = MaybeCreateExprWithCleanups(construct);
14173 ExDecl->setInit(init);
14176 // And make sure it's destructable.
14177 FinalizeVarWithDestructor(ExDecl, recordType);
14183 ExDecl->setInvalidDecl();
14188 /// ActOnExceptionDeclarator - Parsed the exception-declarator in a C++ catch
14190 Decl *Sema::ActOnExceptionDeclarator(Scope *S, Declarator &D) {
14191 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
14192 bool Invalid = D.isInvalidType();
14194 // Check for unexpanded parameter packs.
14195 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
14196 UPPC_ExceptionType)) {
14197 TInfo = Context.getTrivialTypeSourceInfo(Context.IntTy,
14198 D.getIdentifierLoc());
14202 IdentifierInfo *II = D.getIdentifier();
14203 if (NamedDecl *PrevDecl = LookupSingleName(S, II, D.getIdentifierLoc(),
14204 LookupOrdinaryName,
14205 ForVisibleRedeclaration)) {
14206 // The scope should be freshly made just for us. There is just no way
14207 // it contains any previous declaration, except for function parameters in
14208 // a function-try-block's catch statement.
14209 assert(!S->isDeclScope(PrevDecl));
14210 if (isDeclInScope(PrevDecl, CurContext, S)) {
14211 Diag(D.getIdentifierLoc(), diag::err_redefinition)
14212 << D.getIdentifier();
14213 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
14215 } else if (PrevDecl->isTemplateParameter())
14216 // Maybe we will complain about the shadowed template parameter.
14217 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
14220 if (D.getCXXScopeSpec().isSet() && !Invalid) {
14221 Diag(D.getIdentifierLoc(), diag::err_qualified_catch_declarator)
14222 << D.getCXXScopeSpec().getRange();
14226 VarDecl *ExDecl = BuildExceptionDeclaration(
14227 S, TInfo, D.getBeginLoc(), D.getIdentifierLoc(), D.getIdentifier());
14229 ExDecl->setInvalidDecl();
14231 // Add the exception declaration into this scope.
14233 PushOnScopeChains(ExDecl, S);
14235 CurContext->addDecl(ExDecl);
14237 ProcessDeclAttributes(S, ExDecl, D);
14241 Decl *Sema::ActOnStaticAssertDeclaration(SourceLocation StaticAssertLoc,
14243 Expr *AssertMessageExpr,
14244 SourceLocation RParenLoc) {
14245 StringLiteral *AssertMessage =
14246 AssertMessageExpr ? cast<StringLiteral>(AssertMessageExpr) : nullptr;
14248 if (DiagnoseUnexpandedParameterPack(AssertExpr, UPPC_StaticAssertExpression))
14251 return BuildStaticAssertDeclaration(StaticAssertLoc, AssertExpr,
14252 AssertMessage, RParenLoc, false);
14255 Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
14257 StringLiteral *AssertMessage,
14258 SourceLocation RParenLoc,
14260 assert(AssertExpr != nullptr && "Expected non-null condition");
14261 if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
14263 // In a static_assert-declaration, the constant-expression shall be a
14264 // constant expression that can be contextually converted to bool.
14265 ExprResult Converted = PerformContextuallyConvertToBool(AssertExpr);
14266 if (Converted.isInvalid())
14269 ExprResult FullAssertExpr =
14270 ActOnFinishFullExpr(Converted.get(), StaticAssertLoc,
14271 /*DiscardedValue*/ false,
14272 /*IsConstexpr*/ true);
14273 if (FullAssertExpr.isInvalid())
14276 AssertExpr = FullAssertExpr.get();
14279 if (!Failed && VerifyIntegerConstantExpression(AssertExpr, &Cond,
14280 diag::err_static_assert_expression_is_not_constant,
14281 /*AllowFold=*/false).isInvalid())
14284 if (!Failed && !Cond) {
14285 SmallString<256> MsgBuffer;
14286 llvm::raw_svector_ostream Msg(MsgBuffer);
14288 AssertMessage->printPretty(Msg, nullptr, getPrintingPolicy());
14290 Expr *InnerCond = nullptr;
14291 std::string InnerCondDescription;
14292 std::tie(InnerCond, InnerCondDescription) =
14293 findFailedBooleanCondition(Converted.get());
14294 if (InnerCond && !isa<CXXBoolLiteralExpr>(InnerCond)
14295 && !isa<IntegerLiteral>(InnerCond)) {
14296 Diag(StaticAssertLoc, diag::err_static_assert_requirement_failed)
14297 << InnerCondDescription << !AssertMessage
14298 << Msg.str() << InnerCond->getSourceRange();
14300 Diag(StaticAssertLoc, diag::err_static_assert_failed)
14301 << !AssertMessage << Msg.str() << AssertExpr->getSourceRange();
14306 ExprResult FullAssertExpr = ActOnFinishFullExpr(AssertExpr, StaticAssertLoc,
14307 /*DiscardedValue*/false,
14308 /*IsConstexpr*/true);
14309 if (FullAssertExpr.isInvalid())
14312 AssertExpr = FullAssertExpr.get();
14315 Decl *Decl = StaticAssertDecl::Create(Context, CurContext, StaticAssertLoc,
14316 AssertExpr, AssertMessage, RParenLoc,
14319 CurContext->addDecl(Decl);
14323 /// Perform semantic analysis of the given friend type declaration.
14325 /// \returns A friend declaration that.
14326 FriendDecl *Sema::CheckFriendTypeDecl(SourceLocation LocStart,
14327 SourceLocation FriendLoc,
14328 TypeSourceInfo *TSInfo) {
14329 assert(TSInfo && "NULL TypeSourceInfo for friend type declaration");
14331 QualType T = TSInfo->getType();
14332 SourceRange TypeRange = TSInfo->getTypeLoc().getLocalSourceRange();
14334 // C++03 [class.friend]p2:
14335 // An elaborated-type-specifier shall be used in a friend declaration
14338 // * The class-key of the elaborated-type-specifier is required.
14339 if (!CodeSynthesisContexts.empty()) {
14340 // Do not complain about the form of friend template types during any kind
14341 // of code synthesis. For template instantiation, we will have complained
14342 // when the template was defined.
14344 if (!T->isElaboratedTypeSpecifier()) {
14345 // If we evaluated the type to a record type, suggest putting
14347 if (const RecordType *RT = T->getAs<RecordType>()) {
14348 RecordDecl *RD = RT->getDecl();
14350 SmallString<16> InsertionText(" ");
14351 InsertionText += RD->getKindName();
14353 Diag(TypeRange.getBegin(),
14354 getLangOpts().CPlusPlus11 ?
14355 diag::warn_cxx98_compat_unelaborated_friend_type :
14356 diag::ext_unelaborated_friend_type)
14357 << (unsigned) RD->getTagKind()
14359 << FixItHint::CreateInsertion(getLocForEndOfToken(FriendLoc),
14363 getLangOpts().CPlusPlus11 ?
14364 diag::warn_cxx98_compat_nonclass_type_friend :
14365 diag::ext_nonclass_type_friend)
14369 } else if (T->getAs<EnumType>()) {
14371 getLangOpts().CPlusPlus11 ?
14372 diag::warn_cxx98_compat_enum_friend :
14373 diag::ext_enum_friend)
14378 // C++11 [class.friend]p3:
14379 // A friend declaration that does not declare a function shall have one
14380 // of the following forms:
14381 // friend elaborated-type-specifier ;
14382 // friend simple-type-specifier ;
14383 // friend typename-specifier ;
14384 if (getLangOpts().CPlusPlus11 && LocStart != FriendLoc)
14385 Diag(FriendLoc, diag::err_friend_not_first_in_declaration) << T;
14388 // If the type specifier in a friend declaration designates a (possibly
14389 // cv-qualified) class type, that class is declared as a friend; otherwise,
14390 // the friend declaration is ignored.
14391 return FriendDecl::Create(Context, CurContext,
14392 TSInfo->getTypeLoc().getBeginLoc(), TSInfo,
14396 /// Handle a friend tag declaration where the scope specifier was
14398 Decl *Sema::ActOnTemplatedFriendTag(Scope *S, SourceLocation FriendLoc,
14399 unsigned TagSpec, SourceLocation TagLoc,
14400 CXXScopeSpec &SS, IdentifierInfo *Name,
14401 SourceLocation NameLoc,
14402 const ParsedAttributesView &Attr,
14403 MultiTemplateParamsArg TempParamLists) {
14404 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
14406 bool IsMemberSpecialization = false;
14407 bool Invalid = false;
14409 if (TemplateParameterList *TemplateParams =
14410 MatchTemplateParametersToScopeSpecifier(
14411 TagLoc, NameLoc, SS, nullptr, TempParamLists, /*friend*/ true,
14412 IsMemberSpecialization, Invalid)) {
14413 if (TemplateParams->size() > 0) {
14414 // This is a declaration of a class template.
14418 return CheckClassTemplate(S, TagSpec, TUK_Friend, TagLoc, SS, Name,
14419 NameLoc, Attr, TemplateParams, AS_public,
14420 /*ModulePrivateLoc=*/SourceLocation(),
14421 FriendLoc, TempParamLists.size() - 1,
14422 TempParamLists.data()).get();
14424 // The "template<>" header is extraneous.
14425 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
14426 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
14427 IsMemberSpecialization = true;
14431 if (Invalid) return nullptr;
14433 bool isAllExplicitSpecializations = true;
14434 for (unsigned I = TempParamLists.size(); I-- > 0; ) {
14435 if (TempParamLists[I]->size()) {
14436 isAllExplicitSpecializations = false;
14441 // FIXME: don't ignore attributes.
14443 // If it's explicit specializations all the way down, just forget
14444 // about the template header and build an appropriate non-templated
14445 // friend. TODO: for source fidelity, remember the headers.
14446 if (isAllExplicitSpecializations) {
14447 if (SS.isEmpty()) {
14448 bool Owned = false;
14449 bool IsDependent = false;
14450 return ActOnTag(S, TagSpec, TUK_Friend, TagLoc, SS, Name, NameLoc,
14452 /*ModulePrivateLoc=*/SourceLocation(),
14453 MultiTemplateParamsArg(), Owned, IsDependent,
14454 /*ScopedEnumKWLoc=*/SourceLocation(),
14455 /*ScopedEnumUsesClassTag=*/false,
14456 /*UnderlyingType=*/TypeResult(),
14457 /*IsTypeSpecifier=*/false,
14458 /*IsTemplateParamOrArg=*/false);
14461 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
14462 ElaboratedTypeKeyword Keyword
14463 = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
14464 QualType T = CheckTypenameType(Keyword, TagLoc, QualifierLoc,
14469 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
14470 if (isa<DependentNameType>(T)) {
14471 DependentNameTypeLoc TL =
14472 TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
14473 TL.setElaboratedKeywordLoc(TagLoc);
14474 TL.setQualifierLoc(QualifierLoc);
14475 TL.setNameLoc(NameLoc);
14477 ElaboratedTypeLoc TL = TSI->getTypeLoc().castAs<ElaboratedTypeLoc>();
14478 TL.setElaboratedKeywordLoc(TagLoc);
14479 TL.setQualifierLoc(QualifierLoc);
14480 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(NameLoc);
14483 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
14484 TSI, FriendLoc, TempParamLists);
14485 Friend->setAccess(AS_public);
14486 CurContext->addDecl(Friend);
14490 assert(SS.isNotEmpty() && "valid templated tag with no SS and no direct?");
14494 // Handle the case of a templated-scope friend class. e.g.
14495 // template <class T> class A<T>::B;
14496 // FIXME: we don't support these right now.
14497 Diag(NameLoc, diag::warn_template_qualified_friend_unsupported)
14498 << SS.getScopeRep() << SS.getRange() << cast<CXXRecordDecl>(CurContext);
14499 ElaboratedTypeKeyword ETK = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
14500 QualType T = Context.getDependentNameType(ETK, SS.getScopeRep(), Name);
14501 TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
14502 DependentNameTypeLoc TL = TSI->getTypeLoc().castAs<DependentNameTypeLoc>();
14503 TL.setElaboratedKeywordLoc(TagLoc);
14504 TL.setQualifierLoc(SS.getWithLocInContext(Context));
14505 TL.setNameLoc(NameLoc);
14507 FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NameLoc,
14508 TSI, FriendLoc, TempParamLists);
14509 Friend->setAccess(AS_public);
14510 Friend->setUnsupportedFriend(true);
14511 CurContext->addDecl(Friend);
14515 /// Handle a friend type declaration. This works in tandem with
14518 /// Notes on friend class templates:
14520 /// We generally treat friend class declarations as if they were
14521 /// declaring a class. So, for example, the elaborated type specifier
14522 /// in a friend declaration is required to obey the restrictions of a
14523 /// class-head (i.e. no typedefs in the scope chain), template
14524 /// parameters are required to match up with simple template-ids, &c.
14525 /// However, unlike when declaring a template specialization, it's
14526 /// okay to refer to a template specialization without an empty
14527 /// template parameter declaration, e.g.
14528 /// friend class A<T>::B<unsigned>;
14529 /// We permit this as a special case; if there are any template
14530 /// parameters present at all, require proper matching, i.e.
14531 /// template <> template \<class T> friend class A<int>::B;
14532 Decl *Sema::ActOnFriendTypeDecl(Scope *S, const DeclSpec &DS,
14533 MultiTemplateParamsArg TempParams) {
14534 SourceLocation Loc = DS.getBeginLoc();
14536 assert(DS.isFriendSpecified());
14537 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
14539 // C++ [class.friend]p3:
14540 // A friend declaration that does not declare a function shall have one of
14541 // the following forms:
14542 // friend elaborated-type-specifier ;
14543 // friend simple-type-specifier ;
14544 // friend typename-specifier ;
14546 // Any declaration with a type qualifier does not have that form. (It's
14547 // legal to specify a qualified type as a friend, you just can't write the
14549 if (DS.getTypeQualifiers()) {
14550 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
14551 Diag(DS.getConstSpecLoc(), diag::err_friend_decl_spec) << "const";
14552 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
14553 Diag(DS.getVolatileSpecLoc(), diag::err_friend_decl_spec) << "volatile";
14554 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
14555 Diag(DS.getRestrictSpecLoc(), diag::err_friend_decl_spec) << "restrict";
14556 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
14557 Diag(DS.getAtomicSpecLoc(), diag::err_friend_decl_spec) << "_Atomic";
14558 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
14559 Diag(DS.getUnalignedSpecLoc(), diag::err_friend_decl_spec) << "__unaligned";
14562 // Try to convert the decl specifier to a type. This works for
14563 // friend templates because ActOnTag never produces a ClassTemplateDecl
14564 // for a TUK_Friend.
14565 Declarator TheDeclarator(DS, DeclaratorContext::MemberContext);
14566 TypeSourceInfo *TSI = GetTypeForDeclarator(TheDeclarator, S);
14567 QualType T = TSI->getType();
14568 if (TheDeclarator.isInvalidType())
14571 if (DiagnoseUnexpandedParameterPack(Loc, TSI, UPPC_FriendDeclaration))
14574 // This is definitely an error in C++98. It's probably meant to
14575 // be forbidden in C++0x, too, but the specification is just
14578 // The problem is with declarations like the following:
14579 // template <T> friend A<T>::foo;
14580 // where deciding whether a class C is a friend or not now hinges
14581 // on whether there exists an instantiation of A that causes
14582 // 'foo' to equal C. There are restrictions on class-heads
14583 // (which we declare (by fiat) elaborated friend declarations to
14584 // be) that makes this tractable.
14586 // FIXME: handle "template <> friend class A<T>;", which
14587 // is possibly well-formed? Who even knows?
14588 if (TempParams.size() && !T->isElaboratedTypeSpecifier()) {
14589 Diag(Loc, diag::err_tagless_friend_type_template)
14590 << DS.getSourceRange();
14594 // C++98 [class.friend]p1: A friend of a class is a function
14595 // or class that is not a member of the class . . .
14596 // This is fixed in DR77, which just barely didn't make the C++03
14597 // deadline. It's also a very silly restriction that seriously
14598 // affects inner classes and which nobody else seems to implement;
14599 // thus we never diagnose it, not even in -pedantic.
14601 // But note that we could warn about it: it's always useless to
14602 // friend one of your own members (it's not, however, worthless to
14603 // friend a member of an arbitrary specialization of your template).
14606 if (!TempParams.empty())
14607 D = FriendTemplateDecl::Create(Context, CurContext, Loc,
14610 DS.getFriendSpecLoc());
14612 D = CheckFriendTypeDecl(Loc, DS.getFriendSpecLoc(), TSI);
14617 D->setAccess(AS_public);
14618 CurContext->addDecl(D);
14623 NamedDecl *Sema::ActOnFriendFunctionDecl(Scope *S, Declarator &D,
14624 MultiTemplateParamsArg TemplateParams) {
14625 const DeclSpec &DS = D.getDeclSpec();
14627 assert(DS.isFriendSpecified());
14628 assert(DS.getStorageClassSpec() == DeclSpec::SCS_unspecified);
14630 SourceLocation Loc = D.getIdentifierLoc();
14631 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
14633 // C++ [class.friend]p1
14634 // A friend of a class is a function or class....
14635 // Note that this sees through typedefs, which is intended.
14636 // It *doesn't* see through dependent types, which is correct
14637 // according to [temp.arg.type]p3:
14638 // If a declaration acquires a function type through a
14639 // type dependent on a template-parameter and this causes
14640 // a declaration that does not use the syntactic form of a
14641 // function declarator to have a function type, the program
14643 if (!TInfo->getType()->isFunctionType()) {
14644 Diag(Loc, diag::err_unexpected_friend);
14646 // It might be worthwhile to try to recover by creating an
14647 // appropriate declaration.
14651 // C++ [namespace.memdef]p3
14652 // - If a friend declaration in a non-local class first declares a
14653 // class or function, the friend class or function is a member
14654 // of the innermost enclosing namespace.
14655 // - The name of the friend is not found by simple name lookup
14656 // until a matching declaration is provided in that namespace
14657 // scope (either before or after the class declaration granting
14659 // - If a friend function is called, its name may be found by the
14660 // name lookup that considers functions from namespaces and
14661 // classes associated with the types of the function arguments.
14662 // - When looking for a prior declaration of a class or a function
14663 // declared as a friend, scopes outside the innermost enclosing
14664 // namespace scope are not considered.
14666 CXXScopeSpec &SS = D.getCXXScopeSpec();
14667 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
14668 assert(NameInfo.getName());
14670 // Check for unexpanded parameter packs.
14671 if (DiagnoseUnexpandedParameterPack(Loc, TInfo, UPPC_FriendDeclaration) ||
14672 DiagnoseUnexpandedParameterPack(NameInfo, UPPC_FriendDeclaration) ||
14673 DiagnoseUnexpandedParameterPack(SS, UPPC_FriendDeclaration))
14676 // The context we found the declaration in, or in which we should
14677 // create the declaration.
14679 Scope *DCScope = S;
14680 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
14681 ForExternalRedeclaration);
14683 // There are five cases here.
14684 // - There's no scope specifier and we're in a local class. Only look
14685 // for functions declared in the immediately-enclosing block scope.
14686 // We recover from invalid scope qualifiers as if they just weren't there.
14687 FunctionDecl *FunctionContainingLocalClass = nullptr;
14688 if ((SS.isInvalid() || !SS.isSet()) &&
14689 (FunctionContainingLocalClass =
14690 cast<CXXRecordDecl>(CurContext)->isLocalClass())) {
14691 // C++11 [class.friend]p11:
14692 // If a friend declaration appears in a local class and the name
14693 // specified is an unqualified name, a prior declaration is
14694 // looked up without considering scopes that are outside the
14695 // innermost enclosing non-class scope. For a friend function
14696 // declaration, if there is no prior declaration, the program is
14699 // Find the innermost enclosing non-class scope. This is the block
14700 // scope containing the local class definition (or for a nested class,
14701 // the outer local class).
14702 DCScope = S->getFnParent();
14704 // Look up the function name in the scope.
14705 Previous.clear(LookupLocalFriendName);
14706 LookupName(Previous, S, /*AllowBuiltinCreation*/false);
14708 if (!Previous.empty()) {
14709 // All possible previous declarations must have the same context:
14710 // either they were declared at block scope or they are members of
14711 // one of the enclosing local classes.
14712 DC = Previous.getRepresentativeDecl()->getDeclContext();
14714 // This is ill-formed, but provide the context that we would have
14715 // declared the function in, if we were permitted to, for error recovery.
14716 DC = FunctionContainingLocalClass;
14718 adjustContextForLocalExternDecl(DC);
14720 // C++ [class.friend]p6:
14721 // A function can be defined in a friend declaration of a class if and
14722 // only if the class is a non-local class (9.8), the function name is
14723 // unqualified, and the function has namespace scope.
14724 if (D.isFunctionDefinition()) {
14725 Diag(NameInfo.getBeginLoc(), diag::err_friend_def_in_local_class);
14728 // - There's no scope specifier, in which case we just go to the
14729 // appropriate scope and look for a function or function template
14730 // there as appropriate.
14731 } else if (SS.isInvalid() || !SS.isSet()) {
14732 // C++11 [namespace.memdef]p3:
14733 // If the name in a friend declaration is neither qualified nor
14734 // a template-id and the declaration is a function or an
14735 // elaborated-type-specifier, the lookup to determine whether
14736 // the entity has been previously declared shall not consider
14737 // any scopes outside the innermost enclosing namespace.
14738 bool isTemplateId =
14739 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId;
14741 // Find the appropriate context according to the above.
14744 // Skip class contexts. If someone can cite chapter and verse
14745 // for this behavior, that would be nice --- it's what GCC and
14746 // EDG do, and it seems like a reasonable intent, but the spec
14747 // really only says that checks for unqualified existing
14748 // declarations should stop at the nearest enclosing namespace,
14749 // not that they should only consider the nearest enclosing
14751 while (DC->isRecord())
14752 DC = DC->getParent();
14754 DeclContext *LookupDC = DC;
14755 while (LookupDC->isTransparentContext())
14756 LookupDC = LookupDC->getParent();
14759 LookupQualifiedName(Previous, LookupDC);
14761 if (!Previous.empty()) {
14766 if (isTemplateId) {
14767 if (isa<TranslationUnitDecl>(LookupDC)) break;
14769 if (LookupDC->isFileContext()) break;
14771 LookupDC = LookupDC->getParent();
14774 DCScope = getScopeForDeclContext(S, DC);
14776 // - There's a non-dependent scope specifier, in which case we
14777 // compute it and do a previous lookup there for a function
14778 // or function template.
14779 } else if (!SS.getScopeRep()->isDependent()) {
14780 DC = computeDeclContext(SS);
14781 if (!DC) return nullptr;
14783 if (RequireCompleteDeclContext(SS, DC)) return nullptr;
14785 LookupQualifiedName(Previous, DC);
14787 // C++ [class.friend]p1: A friend of a class is a function or
14788 // class that is not a member of the class . . .
14789 if (DC->Equals(CurContext))
14790 Diag(DS.getFriendSpecLoc(),
14791 getLangOpts().CPlusPlus11 ?
14792 diag::warn_cxx98_compat_friend_is_member :
14793 diag::err_friend_is_member);
14795 if (D.isFunctionDefinition()) {
14796 // C++ [class.friend]p6:
14797 // A function can be defined in a friend declaration of a class if and
14798 // only if the class is a non-local class (9.8), the function name is
14799 // unqualified, and the function has namespace scope.
14801 // FIXME: We should only do this if the scope specifier names the
14802 // innermost enclosing namespace; otherwise the fixit changes the
14803 // meaning of the code.
14804 SemaDiagnosticBuilder DB
14805 = Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def);
14807 DB << SS.getScopeRep();
14808 if (DC->isFileContext())
14809 DB << FixItHint::CreateRemoval(SS.getRange());
14813 // - There's a scope specifier that does not match any template
14814 // parameter lists, in which case we use some arbitrary context,
14815 // create a method or method template, and wait for instantiation.
14816 // - There's a scope specifier that does match some template
14817 // parameter lists, which we don't handle right now.
14819 if (D.isFunctionDefinition()) {
14820 // C++ [class.friend]p6:
14821 // A function can be defined in a friend declaration of a class if and
14822 // only if the class is a non-local class (9.8), the function name is
14823 // unqualified, and the function has namespace scope.
14824 Diag(SS.getRange().getBegin(), diag::err_qualified_friend_def)
14825 << SS.getScopeRep();
14829 assert(isa<CXXRecordDecl>(DC) && "friend declaration not in class?");
14832 if (!DC->isRecord()) {
14834 switch (D.getName().getKind()) {
14835 case UnqualifiedIdKind::IK_ConstructorTemplateId:
14836 case UnqualifiedIdKind::IK_ConstructorName:
14839 case UnqualifiedIdKind::IK_DestructorName:
14842 case UnqualifiedIdKind::IK_ConversionFunctionId:
14845 case UnqualifiedIdKind::IK_DeductionGuideName:
14848 case UnqualifiedIdKind::IK_Identifier:
14849 case UnqualifiedIdKind::IK_ImplicitSelfParam:
14850 case UnqualifiedIdKind::IK_LiteralOperatorId:
14851 case UnqualifiedIdKind::IK_OperatorFunctionId:
14852 case UnqualifiedIdKind::IK_TemplateId:
14855 // This implies that it has to be an operator or function.
14856 if (DiagArg >= 0) {
14857 Diag(Loc, diag::err_introducing_special_friend) << DiagArg;
14862 // FIXME: This is an egregious hack to cope with cases where the scope stack
14863 // does not contain the declaration context, i.e., in an out-of-line
14864 // definition of a class.
14865 Scope FakeDCScope(S, Scope::DeclScope, Diags);
14867 FakeDCScope.setEntity(DC);
14868 DCScope = &FakeDCScope;
14871 bool AddToScope = true;
14872 NamedDecl *ND = ActOnFunctionDeclarator(DCScope, D, DC, TInfo, Previous,
14873 TemplateParams, AddToScope);
14874 if (!ND) return nullptr;
14876 assert(ND->getLexicalDeclContext() == CurContext);
14878 // If we performed typo correction, we might have added a scope specifier
14879 // and changed the decl context.
14880 DC = ND->getDeclContext();
14882 // Add the function declaration to the appropriate lookup tables,
14883 // adjusting the redeclarations list as necessary. We don't
14884 // want to do this yet if the friending class is dependent.
14886 // Also update the scope-based lookup if the target context's
14887 // lookup context is in lexical scope.
14888 if (!CurContext->isDependentContext()) {
14889 DC = DC->getRedeclContext();
14890 DC->makeDeclVisibleInContext(ND);
14891 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
14892 PushOnScopeChains(ND, EnclosingScope, /*AddToContext=*/ false);
14895 FriendDecl *FrD = FriendDecl::Create(Context, CurContext,
14896 D.getIdentifierLoc(), ND,
14897 DS.getFriendSpecLoc());
14898 FrD->setAccess(AS_public);
14899 CurContext->addDecl(FrD);
14901 if (ND->isInvalidDecl()) {
14902 FrD->setInvalidDecl();
14904 if (DC->isRecord()) CheckFriendAccess(ND);
14907 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
14908 FD = FTD->getTemplatedDecl();
14910 FD = cast<FunctionDecl>(ND);
14912 // C++11 [dcl.fct.default]p4: If a friend declaration specifies a
14913 // default argument expression, that declaration shall be a definition
14914 // and shall be the only declaration of the function or function
14915 // template in the translation unit.
14916 if (functionDeclHasDefaultArgument(FD)) {
14917 // We can't look at FD->getPreviousDecl() because it may not have been set
14918 // if we're in a dependent context. If the function is known to be a
14919 // redeclaration, we will have narrowed Previous down to the right decl.
14920 if (D.isRedeclaration()) {
14921 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_redeclared);
14922 Diag(Previous.getRepresentativeDecl()->getLocation(),
14923 diag::note_previous_declaration);
14924 } else if (!D.isFunctionDefinition())
14925 Diag(FD->getLocation(), diag::err_friend_decl_with_def_arg_must_be_def);
14928 // Mark templated-scope function declarations as unsupported.
14929 if (FD->getNumTemplateParameterLists() && SS.isValid()) {
14930 Diag(FD->getLocation(), diag::warn_template_qualified_friend_unsupported)
14931 << SS.getScopeRep() << SS.getRange()
14932 << cast<CXXRecordDecl>(CurContext);
14933 FrD->setUnsupportedFriend(true);
14940 void Sema::SetDeclDeleted(Decl *Dcl, SourceLocation DelLoc) {
14941 AdjustDeclIfTemplate(Dcl);
14943 FunctionDecl *Fn = dyn_cast_or_null<FunctionDecl>(Dcl);
14945 Diag(DelLoc, diag::err_deleted_non_function);
14949 // Deleted function does not have a body.
14950 Fn->setWillHaveBody(false);
14952 if (const FunctionDecl *Prev = Fn->getPreviousDecl()) {
14953 // Don't consider the implicit declaration we generate for explicit
14954 // specializations. FIXME: Do not generate these implicit declarations.
14955 if ((Prev->getTemplateSpecializationKind() != TSK_ExplicitSpecialization ||
14956 Prev->getPreviousDecl()) &&
14957 !Prev->isDefined()) {
14958 Diag(DelLoc, diag::err_deleted_decl_not_first);
14959 Diag(Prev->getLocation().isInvalid() ? DelLoc : Prev->getLocation(),
14960 Prev->isImplicit() ? diag::note_previous_implicit_declaration
14961 : diag::note_previous_declaration);
14963 // If the declaration wasn't the first, we delete the function anyway for
14965 Fn = Fn->getCanonicalDecl();
14968 // dllimport/dllexport cannot be deleted.
14969 if (const InheritableAttr *DLLAttr = getDLLAttr(Fn)) {
14970 Diag(Fn->getLocation(), diag::err_attribute_dll_deleted) << DLLAttr;
14971 Fn->setInvalidDecl();
14974 if (Fn->isDeleted())
14977 // See if we're deleting a function which is already known to override a
14978 // non-deleted virtual function.
14979 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn)) {
14980 bool IssuedDiagnostic = false;
14981 for (const CXXMethodDecl *O : MD->overridden_methods()) {
14982 if (!(*MD->begin_overridden_methods())->isDeleted()) {
14983 if (!IssuedDiagnostic) {
14984 Diag(DelLoc, diag::err_deleted_override) << MD->getDeclName();
14985 IssuedDiagnostic = true;
14987 Diag(O->getLocation(), diag::note_overridden_virtual_function);
14990 // If this function was implicitly deleted because it was defaulted,
14991 // explain why it was deleted.
14992 if (IssuedDiagnostic && MD->isDefaulted())
14993 ShouldDeleteSpecialMember(MD, getSpecialMember(MD), nullptr,
14997 // C++11 [basic.start.main]p3:
14998 // A program that defines main as deleted [...] is ill-formed.
15000 Diag(DelLoc, diag::err_deleted_main);
15002 // C++11 [dcl.fct.def.delete]p4:
15003 // A deleted function is implicitly inline.
15004 Fn->setImplicitlyInline();
15005 Fn->setDeletedAsWritten();
15008 void Sema::SetDeclDefaulted(Decl *Dcl, SourceLocation DefaultLoc) {
15009 CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(Dcl);
15012 if (MD->getParent()->isDependentType()) {
15013 MD->setDefaulted();
15014 MD->setExplicitlyDefaulted();
15018 CXXSpecialMember Member = getSpecialMember(MD);
15019 if (Member == CXXInvalid) {
15020 if (!MD->isInvalidDecl())
15021 Diag(DefaultLoc, diag::err_default_special_members);
15025 MD->setDefaulted();
15026 MD->setExplicitlyDefaulted();
15028 // Unset that we will have a body for this function. We might not,
15029 // if it turns out to be trivial, and we don't need this marking now
15030 // that we've marked it as defaulted.
15031 MD->setWillHaveBody(false);
15033 // If this definition appears within the record, do the checking when
15034 // the record is complete.
15035 const FunctionDecl *Primary = MD;
15036 if (const FunctionDecl *Pattern = MD->getTemplateInstantiationPattern())
15037 // Ask the template instantiation pattern that actually had the
15038 // '= default' on it.
15041 // If the method was defaulted on its first declaration, we will have
15042 // already performed the checking in CheckCompletedCXXClass. Such a
15043 // declaration doesn't trigger an implicit definition.
15044 if (Primary->getCanonicalDecl()->isDefaulted())
15047 CheckExplicitlyDefaultedSpecialMember(MD);
15049 if (!MD->isInvalidDecl())
15050 DefineImplicitSpecialMember(*this, MD, DefaultLoc);
15052 Diag(DefaultLoc, diag::err_default_special_members);
15056 static void SearchForReturnInStmt(Sema &Self, Stmt *S) {
15057 for (Stmt *SubStmt : S->children()) {
15060 if (isa<ReturnStmt>(SubStmt))
15061 Self.Diag(SubStmt->getBeginLoc(),
15062 diag::err_return_in_constructor_handler);
15063 if (!isa<Expr>(SubStmt))
15064 SearchForReturnInStmt(Self, SubStmt);
15068 void Sema::DiagnoseReturnInConstructorExceptionHandler(CXXTryStmt *TryBlock) {
15069 for (unsigned I = 0, E = TryBlock->getNumHandlers(); I != E; ++I) {
15070 CXXCatchStmt *Handler = TryBlock->getHandler(I);
15071 SearchForReturnInStmt(*this, Handler);
15075 bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
15076 const CXXMethodDecl *Old) {
15077 const auto *NewFT = New->getType()->getAs<FunctionProtoType>();
15078 const auto *OldFT = Old->getType()->getAs<FunctionProtoType>();
15080 if (OldFT->hasExtParameterInfos()) {
15081 for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
15082 // A parameter of the overriding method should be annotated with noescape
15083 // if the corresponding parameter of the overridden method is annotated.
15084 if (OldFT->getExtParameterInfo(I).isNoEscape() &&
15085 !NewFT->getExtParameterInfo(I).isNoEscape()) {
15086 Diag(New->getParamDecl(I)->getLocation(),
15087 diag::warn_overriding_method_missing_noescape);
15088 Diag(Old->getParamDecl(I)->getLocation(),
15089 diag::note_overridden_marked_noescape);
15093 // Virtual overrides must have the same code_seg.
15094 const auto *OldCSA = Old->getAttr<CodeSegAttr>();
15095 const auto *NewCSA = New->getAttr<CodeSegAttr>();
15096 if ((NewCSA || OldCSA) &&
15097 (!OldCSA || !NewCSA || NewCSA->getName() != OldCSA->getName())) {
15098 Diag(New->getLocation(), diag::err_mismatched_code_seg_override);
15099 Diag(Old->getLocation(), diag::note_previous_declaration);
15103 CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
15105 // If the calling conventions match, everything is fine
15106 if (NewCC == OldCC)
15109 // If the calling conventions mismatch because the new function is static,
15110 // suppress the calling convention mismatch error; the error about static
15111 // function override (err_static_overrides_virtual from
15112 // Sema::CheckFunctionDeclaration) is more clear.
15113 if (New->getStorageClass() == SC_Static)
15116 Diag(New->getLocation(),
15117 diag::err_conflicting_overriding_cc_attributes)
15118 << New->getDeclName() << New->getType() << Old->getType();
15119 Diag(Old->getLocation(), diag::note_overridden_virtual_function);
15123 bool Sema::CheckOverridingFunctionReturnType(const CXXMethodDecl *New,
15124 const CXXMethodDecl *Old) {
15125 QualType NewTy = New->getType()->getAs<FunctionType>()->getReturnType();
15126 QualType OldTy = Old->getType()->getAs<FunctionType>()->getReturnType();
15128 if (Context.hasSameType(NewTy, OldTy) ||
15129 NewTy->isDependentType() || OldTy->isDependentType())
15132 // Check if the return types are covariant
15133 QualType NewClassTy, OldClassTy;
15135 /// Both types must be pointers or references to classes.
15136 if (const PointerType *NewPT = NewTy->getAs<PointerType>()) {
15137 if (const PointerType *OldPT = OldTy->getAs<PointerType>()) {
15138 NewClassTy = NewPT->getPointeeType();
15139 OldClassTy = OldPT->getPointeeType();
15141 } else if (const ReferenceType *NewRT = NewTy->getAs<ReferenceType>()) {
15142 if (const ReferenceType *OldRT = OldTy->getAs<ReferenceType>()) {
15143 if (NewRT->getTypeClass() == OldRT->getTypeClass()) {
15144 NewClassTy = NewRT->getPointeeType();
15145 OldClassTy = OldRT->getPointeeType();
15150 // The return types aren't either both pointers or references to a class type.
15151 if (NewClassTy.isNull()) {
15152 Diag(New->getLocation(),
15153 diag::err_different_return_type_for_overriding_virtual_function)
15154 << New->getDeclName() << NewTy << OldTy
15155 << New->getReturnTypeSourceRange();
15156 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
15157 << Old->getReturnTypeSourceRange();
15162 if (!Context.hasSameUnqualifiedType(NewClassTy, OldClassTy)) {
15163 // C++14 [class.virtual]p8:
15164 // If the class type in the covariant return type of D::f differs from
15165 // that of B::f, the class type in the return type of D::f shall be
15166 // complete at the point of declaration of D::f or shall be the class
15168 if (const RecordType *RT = NewClassTy->getAs<RecordType>()) {
15169 if (!RT->isBeingDefined() &&
15170 RequireCompleteType(New->getLocation(), NewClassTy,
15171 diag::err_covariant_return_incomplete,
15172 New->getDeclName()))
15176 // Check if the new class derives from the old class.
15177 if (!IsDerivedFrom(New->getLocation(), NewClassTy, OldClassTy)) {
15178 Diag(New->getLocation(), diag::err_covariant_return_not_derived)
15179 << New->getDeclName() << NewTy << OldTy
15180 << New->getReturnTypeSourceRange();
15181 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
15182 << Old->getReturnTypeSourceRange();
15186 // Check if we the conversion from derived to base is valid.
15187 if (CheckDerivedToBaseConversion(
15188 NewClassTy, OldClassTy,
15189 diag::err_covariant_return_inaccessible_base,
15190 diag::err_covariant_return_ambiguous_derived_to_base_conv,
15191 New->getLocation(), New->getReturnTypeSourceRange(),
15192 New->getDeclName(), nullptr)) {
15193 // FIXME: this note won't trigger for delayed access control
15194 // diagnostics, and it's impossible to get an undelayed error
15195 // here from access control during the original parse because
15196 // the ParsingDeclSpec/ParsingDeclarator are still in scope.
15197 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
15198 << Old->getReturnTypeSourceRange();
15203 // The qualifiers of the return types must be the same.
15204 if (NewTy.getLocalCVRQualifiers() != OldTy.getLocalCVRQualifiers()) {
15205 Diag(New->getLocation(),
15206 diag::err_covariant_return_type_different_qualifications)
15207 << New->getDeclName() << NewTy << OldTy
15208 << New->getReturnTypeSourceRange();
15209 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
15210 << Old->getReturnTypeSourceRange();
15215 // The new class type must have the same or less qualifiers as the old type.
15216 if (NewClassTy.isMoreQualifiedThan(OldClassTy)) {
15217 Diag(New->getLocation(),
15218 diag::err_covariant_return_type_class_type_more_qualified)
15219 << New->getDeclName() << NewTy << OldTy
15220 << New->getReturnTypeSourceRange();
15221 Diag(Old->getLocation(), diag::note_overridden_virtual_function)
15222 << Old->getReturnTypeSourceRange();
15229 /// Mark the given method pure.
15231 /// \param Method the method to be marked pure.
15233 /// \param InitRange the source range that covers the "0" initializer.
15234 bool Sema::CheckPureMethod(CXXMethodDecl *Method, SourceRange InitRange) {
15235 SourceLocation EndLoc = InitRange.getEnd();
15236 if (EndLoc.isValid())
15237 Method->setRangeEnd(EndLoc);
15239 if (Method->isVirtual() || Method->getParent()->isDependentContext()) {
15244 if (!Method->isInvalidDecl())
15245 Diag(Method->getLocation(), diag::err_non_virtual_pure)
15246 << Method->getDeclName() << InitRange;
15250 void Sema::ActOnPureSpecifier(Decl *D, SourceLocation ZeroLoc) {
15251 if (D->getFriendObjectKind())
15252 Diag(D->getLocation(), diag::err_pure_friend);
15253 else if (auto *M = dyn_cast<CXXMethodDecl>(D))
15254 CheckPureMethod(M, ZeroLoc);
15256 Diag(D->getLocation(), diag::err_illegal_initializer);
15259 /// Determine whether the given declaration is a global variable or
15260 /// static data member.
15261 static bool isNonlocalVariable(const Decl *D) {
15262 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(D))
15263 return Var->hasGlobalStorage();
15268 /// Invoked when we are about to parse an initializer for the declaration
15271 /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
15272 /// static data member of class X, names should be looked up in the scope of
15273 /// class X. If the declaration had a scope specifier, a scope will have
15274 /// been created and passed in for this purpose. Otherwise, S will be null.
15275 void Sema::ActOnCXXEnterDeclInitializer(Scope *S, Decl *D) {
15276 // If there is no declaration, there was an error parsing it.
15277 if (!D || D->isInvalidDecl())
15280 // We will always have a nested name specifier here, but this declaration
15281 // might not be out of line if the specifier names the current namespace:
15284 if (S && D->isOutOfLine())
15285 EnterDeclaratorContext(S, D->getDeclContext());
15287 // If we are parsing the initializer for a static data member, push a
15288 // new expression evaluation context that is associated with this static
15290 if (isNonlocalVariable(D))
15291 PushExpressionEvaluationContext(
15292 ExpressionEvaluationContext::PotentiallyEvaluated, D);
15295 /// Invoked after we are finished parsing an initializer for the declaration D.
15296 void Sema::ActOnCXXExitDeclInitializer(Scope *S, Decl *D) {
15297 // If there is no declaration, there was an error parsing it.
15298 if (!D || D->isInvalidDecl())
15301 if (isNonlocalVariable(D))
15302 PopExpressionEvaluationContext();
15304 if (S && D->isOutOfLine())
15305 ExitDeclaratorContext(S);
15308 /// ActOnCXXConditionDeclarationExpr - Parsed a condition declaration of a
15309 /// C++ if/switch/while/for statement.
15310 /// e.g: "if (int x = f()) {...}"
15311 DeclResult Sema::ActOnCXXConditionDeclaration(Scope *S, Declarator &D) {
15313 // The declarator shall not specify a function or an array.
15314 // The type-specifier-seq shall not contain typedef and shall not declare a
15315 // new class or enumeration.
15316 assert(D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
15317 "Parser allowed 'typedef' as storage class of condition decl.");
15319 Decl *Dcl = ActOnDeclarator(S, D);
15323 if (isa<FunctionDecl>(Dcl)) { // The declarator shall not specify a function.
15324 Diag(Dcl->getLocation(), diag::err_invalid_use_of_function_type)
15325 << D.getSourceRange();
15332 void Sema::LoadExternalVTableUses() {
15333 if (!ExternalSource)
15336 SmallVector<ExternalVTableUse, 4> VTables;
15337 ExternalSource->ReadUsedVTables(VTables);
15338 SmallVector<VTableUse, 4> NewUses;
15339 for (unsigned I = 0, N = VTables.size(); I != N; ++I) {
15340 llvm::DenseMap<CXXRecordDecl *, bool>::iterator Pos
15341 = VTablesUsed.find(VTables[I].Record);
15342 // Even if a definition wasn't required before, it may be required now.
15343 if (Pos != VTablesUsed.end()) {
15344 if (!Pos->second && VTables[I].DefinitionRequired)
15345 Pos->second = true;
15349 VTablesUsed[VTables[I].Record] = VTables[I].DefinitionRequired;
15350 NewUses.push_back(VTableUse(VTables[I].Record, VTables[I].Location));
15353 VTableUses.insert(VTableUses.begin(), NewUses.begin(), NewUses.end());
15356 void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
15357 bool DefinitionRequired) {
15358 // Ignore any vtable uses in unevaluated operands or for classes that do
15359 // not have a vtable.
15360 if (!Class->isDynamicClass() || Class->isDependentContext() ||
15361 CurContext->isDependentContext() || isUnevaluatedContext())
15363 // Do not mark as used if compiling for the device outside of the target
15365 if (LangOpts.OpenMP && LangOpts.OpenMPIsDevice &&
15366 !isInOpenMPDeclareTargetContext() &&
15367 !isInOpenMPTargetExecutionDirective()) {
15368 if (!DefinitionRequired)
15369 MarkVirtualMembersReferenced(Loc, Class);
15373 // Try to insert this class into the map.
15374 LoadExternalVTableUses();
15375 Class = Class->getCanonicalDecl();
15376 std::pair<llvm::DenseMap<CXXRecordDecl *, bool>::iterator, bool>
15377 Pos = VTablesUsed.insert(std::make_pair(Class, DefinitionRequired));
15379 // If we already had an entry, check to see if we are promoting this vtable
15380 // to require a definition. If so, we need to reappend to the VTableUses
15381 // list, since we may have already processed the first entry.
15382 if (DefinitionRequired && !Pos.first->second) {
15383 Pos.first->second = true;
15385 // Otherwise, we can early exit.
15389 // The Microsoft ABI requires that we perform the destructor body
15390 // checks (i.e. operator delete() lookup) when the vtable is marked used, as
15391 // the deleting destructor is emitted with the vtable, not with the
15392 // destructor definition as in the Itanium ABI.
15393 if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
15394 CXXDestructorDecl *DD = Class->getDestructor();
15395 if (DD && DD->isVirtual() && !DD->isDeleted()) {
15396 if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
15397 // If this is an out-of-line declaration, marking it referenced will
15398 // not do anything. Manually call CheckDestructor to look up operator
15400 ContextRAII SavedContext(*this, DD);
15401 CheckDestructor(DD);
15403 MarkFunctionReferenced(Loc, Class->getDestructor());
15409 // Local classes need to have their virtual members marked
15410 // immediately. For all other classes, we mark their virtual members
15411 // at the end of the translation unit.
15412 if (Class->isLocalClass())
15413 MarkVirtualMembersReferenced(Loc, Class);
15415 VTableUses.push_back(std::make_pair(Class, Loc));
15418 bool Sema::DefineUsedVTables() {
15419 LoadExternalVTableUses();
15420 if (VTableUses.empty())
15423 // Note: The VTableUses vector could grow as a result of marking
15424 // the members of a class as "used", so we check the size each
15425 // time through the loop and prefer indices (which are stable) to
15426 // iterators (which are not).
15427 bool DefinedAnything = false;
15428 for (unsigned I = 0; I != VTableUses.size(); ++I) {
15429 CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
15432 TemplateSpecializationKind ClassTSK =
15433 Class->getTemplateSpecializationKind();
15435 SourceLocation Loc = VTableUses[I].second;
15437 bool DefineVTable = true;
15439 // If this class has a key function, but that key function is
15440 // defined in another translation unit, we don't need to emit the
15441 // vtable even though we're using it.
15442 const CXXMethodDecl *KeyFunction = Context.getCurrentKeyFunction(Class);
15443 if (KeyFunction && !KeyFunction->hasBody()) {
15444 // The key function is in another translation unit.
15445 DefineVTable = false;
15446 TemplateSpecializationKind TSK =
15447 KeyFunction->getTemplateSpecializationKind();
15448 assert(TSK != TSK_ExplicitInstantiationDefinition &&
15449 TSK != TSK_ImplicitInstantiation &&
15450 "Instantiations don't have key functions");
15452 } else if (!KeyFunction) {
15453 // If we have a class with no key function that is the subject
15454 // of an explicit instantiation declaration, suppress the
15455 // vtable; it will live with the explicit instantiation
15457 bool IsExplicitInstantiationDeclaration =
15458 ClassTSK == TSK_ExplicitInstantiationDeclaration;
15459 for (auto R : Class->redecls()) {
15460 TemplateSpecializationKind TSK
15461 = cast<CXXRecordDecl>(R)->getTemplateSpecializationKind();
15462 if (TSK == TSK_ExplicitInstantiationDeclaration)
15463 IsExplicitInstantiationDeclaration = true;
15464 else if (TSK == TSK_ExplicitInstantiationDefinition) {
15465 IsExplicitInstantiationDeclaration = false;
15470 if (IsExplicitInstantiationDeclaration)
15471 DefineVTable = false;
15474 // The exception specifications for all virtual members may be needed even
15475 // if we are not providing an authoritative form of the vtable in this TU.
15476 // We may choose to emit it available_externally anyway.
15477 if (!DefineVTable) {
15478 MarkVirtualMemberExceptionSpecsNeeded(Loc, Class);
15482 // Mark all of the virtual members of this class as referenced, so
15483 // that we can build a vtable. Then, tell the AST consumer that a
15484 // vtable for this class is required.
15485 DefinedAnything = true;
15486 MarkVirtualMembersReferenced(Loc, Class);
15487 CXXRecordDecl *Canonical = Class->getCanonicalDecl();
15488 if (VTablesUsed[Canonical])
15489 Consumer.HandleVTable(Class);
15491 // Warn if we're emitting a weak vtable. The vtable will be weak if there is
15492 // no key function or the key function is inlined. Don't warn in C++ ABIs
15493 // that lack key functions, since the user won't be able to make one.
15494 if (Context.getTargetInfo().getCXXABI().hasKeyFunctions() &&
15495 Class->isExternallyVisible() && ClassTSK != TSK_ImplicitInstantiation) {
15496 const FunctionDecl *KeyFunctionDef = nullptr;
15497 if (!KeyFunction || (KeyFunction->hasBody(KeyFunctionDef) &&
15498 KeyFunctionDef->isInlined())) {
15499 Diag(Class->getLocation(),
15500 ClassTSK == TSK_ExplicitInstantiationDefinition
15501 ? diag::warn_weak_template_vtable
15502 : diag::warn_weak_vtable)
15507 VTableUses.clear();
15509 return DefinedAnything;
15512 void Sema::MarkVirtualMemberExceptionSpecsNeeded(SourceLocation Loc,
15513 const CXXRecordDecl *RD) {
15514 for (const auto *I : RD->methods())
15515 if (I->isVirtual() && !I->isPure())
15516 ResolveExceptionSpec(Loc, I->getType()->castAs<FunctionProtoType>());
15519 void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
15520 const CXXRecordDecl *RD,
15521 bool ConstexprOnly) {
15522 // Mark all functions which will appear in RD's vtable as used.
15523 CXXFinalOverriderMap FinalOverriders;
15524 RD->getFinalOverriders(FinalOverriders);
15525 for (CXXFinalOverriderMap::const_iterator I = FinalOverriders.begin(),
15526 E = FinalOverriders.end();
15528 for (OverridingMethods::const_iterator OI = I->second.begin(),
15529 OE = I->second.end();
15531 assert(OI->second.size() > 0 && "no final overrider");
15532 CXXMethodDecl *Overrider = OI->second.front().Method;
15534 // C++ [basic.def.odr]p2:
15535 // [...] A virtual member function is used if it is not pure. [...]
15536 if (!Overrider->isPure() && (!ConstexprOnly || Overrider->isConstexpr()))
15537 MarkFunctionReferenced(Loc, Overrider);
15541 // Only classes that have virtual bases need a VTT.
15542 if (RD->getNumVBases() == 0)
15545 for (const auto &I : RD->bases()) {
15547 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
15548 if (Base->getNumVBases() == 0)
15550 MarkVirtualMembersReferenced(Loc, Base);
15554 /// SetIvarInitializers - This routine builds initialization ASTs for the
15555 /// Objective-C implementation whose ivars need be initialized.
15556 void Sema::SetIvarInitializers(ObjCImplementationDecl *ObjCImplementation) {
15557 if (!getLangOpts().CPlusPlus)
15559 if (ObjCInterfaceDecl *OID = ObjCImplementation->getClassInterface()) {
15560 SmallVector<ObjCIvarDecl*, 8> ivars;
15561 CollectIvarsToConstructOrDestruct(OID, ivars);
15564 SmallVector<CXXCtorInitializer*, 32> AllToInit;
15565 for (unsigned i = 0; i < ivars.size(); i++) {
15566 FieldDecl *Field = ivars[i];
15567 if (Field->isInvalidDecl())
15570 CXXCtorInitializer *Member;
15571 InitializedEntity InitEntity = InitializedEntity::InitializeMember(Field);
15572 InitializationKind InitKind =
15573 InitializationKind::CreateDefault(ObjCImplementation->getLocation());
15575 InitializationSequence InitSeq(*this, InitEntity, InitKind, None);
15576 ExprResult MemberInit =
15577 InitSeq.Perform(*this, InitEntity, InitKind, None);
15578 MemberInit = MaybeCreateExprWithCleanups(MemberInit);
15579 // Note, MemberInit could actually come back empty if no initialization
15580 // is required (e.g., because it would call a trivial default constructor)
15581 if (!MemberInit.get() || MemberInit.isInvalid())
15585 new (Context) CXXCtorInitializer(Context, Field, SourceLocation(),
15587 MemberInit.getAs<Expr>(),
15589 AllToInit.push_back(Member);
15591 // Be sure that the destructor is accessible and is marked as referenced.
15592 if (const RecordType *RecordTy =
15593 Context.getBaseElementType(Field->getType())
15594 ->getAs<RecordType>()) {
15595 CXXRecordDecl *RD = cast<CXXRecordDecl>(RecordTy->getDecl());
15596 if (CXXDestructorDecl *Destructor = LookupDestructor(RD)) {
15597 MarkFunctionReferenced(Field->getLocation(), Destructor);
15598 CheckDestructorAccess(Field->getLocation(), Destructor,
15599 PDiag(diag::err_access_dtor_ivar)
15600 << Context.getBaseElementType(Field->getType()));
15604 ObjCImplementation->setIvarInitializers(Context,
15605 AllToInit.data(), AllToInit.size());
15610 void DelegatingCycleHelper(CXXConstructorDecl* Ctor,
15611 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Valid,
15612 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Invalid,
15613 llvm::SmallPtrSet<CXXConstructorDecl*, 4> &Current,
15615 if (Ctor->isInvalidDecl())
15618 CXXConstructorDecl *Target = Ctor->getTargetConstructor();
15620 // Target may not be determinable yet, for instance if this is a dependent
15621 // call in an uninstantiated template.
15623 const FunctionDecl *FNTarget = nullptr;
15624 (void)Target->hasBody(FNTarget);
15625 Target = const_cast<CXXConstructorDecl*>(
15626 cast_or_null<CXXConstructorDecl>(FNTarget));
15629 CXXConstructorDecl *Canonical = Ctor->getCanonicalDecl(),
15630 // Avoid dereferencing a null pointer here.
15631 *TCanonical = Target? Target->getCanonicalDecl() : nullptr;
15633 if (!Current.insert(Canonical).second)
15636 // We know that beyond here, we aren't chaining into a cycle.
15637 if (!Target || !Target->isDelegatingConstructor() ||
15638 Target->isInvalidDecl() || Valid.count(TCanonical)) {
15639 Valid.insert(Current.begin(), Current.end());
15641 // We've hit a cycle.
15642 } else if (TCanonical == Canonical || Invalid.count(TCanonical) ||
15643 Current.count(TCanonical)) {
15644 // If we haven't diagnosed this cycle yet, do so now.
15645 if (!Invalid.count(TCanonical)) {
15646 S.Diag((*Ctor->init_begin())->getSourceLocation(),
15647 diag::warn_delegating_ctor_cycle)
15650 // Don't add a note for a function delegating directly to itself.
15651 if (TCanonical != Canonical)
15652 S.Diag(Target->getLocation(), diag::note_it_delegates_to);
15654 CXXConstructorDecl *C = Target;
15655 while (C->getCanonicalDecl() != Canonical) {
15656 const FunctionDecl *FNTarget = nullptr;
15657 (void)C->getTargetConstructor()->hasBody(FNTarget);
15658 assert(FNTarget && "Ctor cycle through bodiless function");
15660 C = const_cast<CXXConstructorDecl*>(
15661 cast<CXXConstructorDecl>(FNTarget));
15662 S.Diag(C->getLocation(), diag::note_which_delegates_to);
15666 Invalid.insert(Current.begin(), Current.end());
15669 DelegatingCycleHelper(Target, Valid, Invalid, Current, S);
15674 void Sema::CheckDelegatingCtorCycles() {
15675 llvm::SmallPtrSet<CXXConstructorDecl*, 4> Valid, Invalid, Current;
15677 for (DelegatingCtorDeclsType::iterator
15678 I = DelegatingCtorDecls.begin(ExternalSource),
15679 E = DelegatingCtorDecls.end();
15681 DelegatingCycleHelper(*I, Valid, Invalid, Current, *this);
15683 for (auto CI = Invalid.begin(), CE = Invalid.end(); CI != CE; ++CI)
15684 (*CI)->setInvalidDecl();
15688 /// AST visitor that finds references to the 'this' expression.
15689 class FindCXXThisExpr : public RecursiveASTVisitor<FindCXXThisExpr> {
15693 explicit FindCXXThisExpr(Sema &S) : S(S) { }
15695 bool VisitCXXThisExpr(CXXThisExpr *E) {
15696 S.Diag(E->getLocation(), diag::err_this_static_member_func)
15697 << E->isImplicit();
15703 bool Sema::checkThisInStaticMemberFunctionType(CXXMethodDecl *Method) {
15704 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
15708 TypeLoc TL = TSInfo->getTypeLoc();
15709 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
15713 // C++11 [expr.prim.general]p3:
15714 // [The expression this] shall not appear before the optional
15715 // cv-qualifier-seq and it shall not appear within the declaration of a
15716 // static member function (although its type and value category are defined
15717 // within a static member function as they are within a non-static member
15718 // function). [ Note: this is because declaration matching does not occur
15719 // until the complete declarator is known. - end note ]
15720 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
15721 FindCXXThisExpr Finder(*this);
15723 // If the return type came after the cv-qualifier-seq, check it now.
15724 if (Proto->hasTrailingReturn() &&
15725 !Finder.TraverseTypeLoc(ProtoTL.getReturnLoc()))
15728 // Check the exception specification.
15729 if (checkThisInStaticMemberFunctionExceptionSpec(Method))
15732 return checkThisInStaticMemberFunctionAttributes(Method);
15735 bool Sema::checkThisInStaticMemberFunctionExceptionSpec(CXXMethodDecl *Method) {
15736 TypeSourceInfo *TSInfo = Method->getTypeSourceInfo();
15740 TypeLoc TL = TSInfo->getTypeLoc();
15741 FunctionProtoTypeLoc ProtoTL = TL.getAs<FunctionProtoTypeLoc>();
15745 const FunctionProtoType *Proto = ProtoTL.getTypePtr();
15746 FindCXXThisExpr Finder(*this);
15748 switch (Proto->getExceptionSpecType()) {
15750 case EST_Uninstantiated:
15751 case EST_Unevaluated:
15752 case EST_BasicNoexcept:
15754 case EST_DynamicNone:
15759 case EST_DependentNoexcept:
15760 case EST_NoexceptFalse:
15761 case EST_NoexceptTrue:
15762 if (!Finder.TraverseStmt(Proto->getNoexceptExpr()))
15767 for (const auto &E : Proto->exceptions()) {
15768 if (!Finder.TraverseType(E))
15777 bool Sema::checkThisInStaticMemberFunctionAttributes(CXXMethodDecl *Method) {
15778 FindCXXThisExpr Finder(*this);
15780 // Check attributes.
15781 for (const auto *A : Method->attrs()) {
15782 // FIXME: This should be emitted by tblgen.
15783 Expr *Arg = nullptr;
15784 ArrayRef<Expr *> Args;
15785 if (const auto *G = dyn_cast<GuardedByAttr>(A))
15787 else if (const auto *G = dyn_cast<PtGuardedByAttr>(A))
15789 else if (const auto *AA = dyn_cast<AcquiredAfterAttr>(A))
15790 Args = llvm::makeArrayRef(AA->args_begin(), AA->args_size());
15791 else if (const auto *AB = dyn_cast<AcquiredBeforeAttr>(A))
15792 Args = llvm::makeArrayRef(AB->args_begin(), AB->args_size());
15793 else if (const auto *ETLF = dyn_cast<ExclusiveTrylockFunctionAttr>(A)) {
15794 Arg = ETLF->getSuccessValue();
15795 Args = llvm::makeArrayRef(ETLF->args_begin(), ETLF->args_size());
15796 } else if (const auto *STLF = dyn_cast<SharedTrylockFunctionAttr>(A)) {
15797 Arg = STLF->getSuccessValue();
15798 Args = llvm::makeArrayRef(STLF->args_begin(), STLF->args_size());
15799 } else if (const auto *LR = dyn_cast<LockReturnedAttr>(A))
15800 Arg = LR->getArg();
15801 else if (const auto *LE = dyn_cast<LocksExcludedAttr>(A))
15802 Args = llvm::makeArrayRef(LE->args_begin(), LE->args_size());
15803 else if (const auto *RC = dyn_cast<RequiresCapabilityAttr>(A))
15804 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
15805 else if (const auto *AC = dyn_cast<AcquireCapabilityAttr>(A))
15806 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
15807 else if (const auto *AC = dyn_cast<TryAcquireCapabilityAttr>(A))
15808 Args = llvm::makeArrayRef(AC->args_begin(), AC->args_size());
15809 else if (const auto *RC = dyn_cast<ReleaseCapabilityAttr>(A))
15810 Args = llvm::makeArrayRef(RC->args_begin(), RC->args_size());
15812 if (Arg && !Finder.TraverseStmt(Arg))
15815 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
15816 if (!Finder.TraverseStmt(Args[I]))
15824 void Sema::checkExceptionSpecification(
15825 bool IsTopLevel, ExceptionSpecificationType EST,
15826 ArrayRef<ParsedType> DynamicExceptions,
15827 ArrayRef<SourceRange> DynamicExceptionRanges, Expr *NoexceptExpr,
15828 SmallVectorImpl<QualType> &Exceptions,
15829 FunctionProtoType::ExceptionSpecInfo &ESI) {
15830 Exceptions.clear();
15832 if (EST == EST_Dynamic) {
15833 Exceptions.reserve(DynamicExceptions.size());
15834 for (unsigned ei = 0, ee = DynamicExceptions.size(); ei != ee; ++ei) {
15835 // FIXME: Preserve type source info.
15836 QualType ET = GetTypeFromParser(DynamicExceptions[ei]);
15839 SmallVector<UnexpandedParameterPack, 2> Unexpanded;
15840 collectUnexpandedParameterPacks(ET, Unexpanded);
15841 if (!Unexpanded.empty()) {
15842 DiagnoseUnexpandedParameterPacks(
15843 DynamicExceptionRanges[ei].getBegin(), UPPC_ExceptionType,
15849 // Check that the type is valid for an exception spec, and
15851 if (!CheckSpecifiedExceptionType(ET, DynamicExceptionRanges[ei]))
15852 Exceptions.push_back(ET);
15854 ESI.Exceptions = Exceptions;
15858 if (isComputedNoexcept(EST)) {
15859 assert((NoexceptExpr->isTypeDependent() ||
15860 NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
15862 "Parser should have made sure that the expression is boolean");
15863 if (IsTopLevel && DiagnoseUnexpandedParameterPack(NoexceptExpr)) {
15864 ESI.Type = EST_BasicNoexcept;
15868 ESI.NoexceptExpr = NoexceptExpr;
15873 void Sema::actOnDelayedExceptionSpecification(Decl *MethodD,
15874 ExceptionSpecificationType EST,
15875 SourceRange SpecificationRange,
15876 ArrayRef<ParsedType> DynamicExceptions,
15877 ArrayRef<SourceRange> DynamicExceptionRanges,
15878 Expr *NoexceptExpr) {
15882 // Dig out the method we're referring to.
15883 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(MethodD))
15884 MethodD = FunTmpl->getTemplatedDecl();
15886 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(MethodD);
15890 // Check the exception specification.
15891 llvm::SmallVector<QualType, 4> Exceptions;
15892 FunctionProtoType::ExceptionSpecInfo ESI;
15893 checkExceptionSpecification(/*IsTopLevel*/true, EST, DynamicExceptions,
15894 DynamicExceptionRanges, NoexceptExpr, Exceptions,
15897 // Update the exception specification on the function type.
15898 Context.adjustExceptionSpec(Method, ESI, /*AsWritten*/true);
15900 if (Method->isStatic())
15901 checkThisInStaticMemberFunctionExceptionSpec(Method);
15903 if (Method->isVirtual()) {
15904 // Check overrides, which we previously had to delay.
15905 for (const CXXMethodDecl *O : Method->overridden_methods())
15906 CheckOverridingFunctionExceptionSpec(Method, O);
15910 /// HandleMSProperty - Analyze a __delcspec(property) field of a C++ class.
15912 MSPropertyDecl *Sema::HandleMSProperty(Scope *S, RecordDecl *Record,
15913 SourceLocation DeclStart, Declarator &D,
15915 InClassInitStyle InitStyle,
15916 AccessSpecifier AS,
15917 const ParsedAttr &MSPropertyAttr) {
15918 IdentifierInfo *II = D.getIdentifier();
15920 Diag(DeclStart, diag::err_anonymous_property);
15923 SourceLocation Loc = D.getIdentifierLoc();
15925 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15926 QualType T = TInfo->getType();
15927 if (getLangOpts().CPlusPlus) {
15928 CheckExtraCXXDefaultArguments(D);
15930 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
15931 UPPC_DataMemberType)) {
15932 D.setInvalidType();
15934 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
15938 DiagnoseFunctionSpecifiers(D.getDeclSpec());
15940 if (D.getDeclSpec().isInlineSpecified())
15941 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
15942 << getLangOpts().CPlusPlus17;
15943 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
15944 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
15945 diag::err_invalid_thread)
15946 << DeclSpec::getSpecifierName(TSCS);
15948 // Check to see if this name was declared as a member previously
15949 NamedDecl *PrevDecl = nullptr;
15950 LookupResult Previous(*this, II, Loc, LookupMemberName,
15951 ForVisibleRedeclaration);
15952 LookupName(Previous, S);
15953 switch (Previous.getResultKind()) {
15954 case LookupResult::Found:
15955 case LookupResult::FoundUnresolvedValue:
15956 PrevDecl = Previous.getAsSingle<NamedDecl>();
15959 case LookupResult::FoundOverloaded:
15960 PrevDecl = Previous.getRepresentativeDecl();
15963 case LookupResult::NotFound:
15964 case LookupResult::NotFoundInCurrentInstantiation:
15965 case LookupResult::Ambiguous:
15969 if (PrevDecl && PrevDecl->isTemplateParameter()) {
15970 // Maybe we will complain about the shadowed template parameter.
15971 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
15972 // Just pretend that we didn't see the previous declaration.
15973 PrevDecl = nullptr;
15976 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
15977 PrevDecl = nullptr;
15979 SourceLocation TSSL = D.getBeginLoc();
15980 MSPropertyDecl *NewPD =
15981 MSPropertyDecl::Create(Context, Record, Loc, II, T, TInfo, TSSL,
15982 MSPropertyAttr.getPropertyDataGetter(),
15983 MSPropertyAttr.getPropertyDataSetter());
15984 ProcessDeclAttributes(TUScope, NewPD, D);
15985 NewPD->setAccess(AS);
15987 if (NewPD->isInvalidDecl())
15988 Record->setInvalidDecl();
15990 if (D.getDeclSpec().isModulePrivateSpecified())
15991 NewPD->setModulePrivate();
15993 if (NewPD->isInvalidDecl() && PrevDecl) {
15994 // Don't introduce NewFD into scope; there's already something
15995 // with the same name in the same scope.
15997 PushOnScopeChains(NewPD, S);
15999 Record->addDecl(NewPD);