1 //===--- SemaDecl.cpp - Semantic Analysis for Declarations ----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements semantic analysis for declarations.
12 //===----------------------------------------------------------------------===//
14 #include "TypeLocBuilder.h"
15 #include "clang/AST/ASTConsumer.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/ASTLambda.h"
18 #include "clang/AST/CXXInheritance.h"
19 #include "clang/AST/CharUnits.h"
20 #include "clang/AST/CommentDiagnostic.h"
21 #include "clang/AST/DeclCXX.h"
22 #include "clang/AST/DeclObjC.h"
23 #include "clang/AST/DeclTemplate.h"
24 #include "clang/AST/EvaluatedExprVisitor.h"
25 #include "clang/AST/ExprCXX.h"
26 #include "clang/AST/StmtCXX.h"
27 #include "clang/Basic/Builtins.h"
28 #include "clang/Basic/PartialDiagnostic.h"
29 #include "clang/Basic/SourceManager.h"
30 #include "clang/Basic/TargetInfo.h"
31 #include "clang/Lex/HeaderSearch.h" // TODO: Sema shouldn't depend on Lex
32 #include "clang/Lex/Lexer.h" // TODO: Extract static functions to fix layering.
33 #include "clang/Lex/ModuleLoader.h" // TODO: Sema shouldn't depend on Lex
34 #include "clang/Lex/Preprocessor.h" // Included for isCodeCompletionEnabled()
35 #include "clang/Sema/CXXFieldCollector.h"
36 #include "clang/Sema/DeclSpec.h"
37 #include "clang/Sema/DelayedDiagnostic.h"
38 #include "clang/Sema/Initialization.h"
39 #include "clang/Sema/Lookup.h"
40 #include "clang/Sema/ParsedTemplate.h"
41 #include "clang/Sema/Scope.h"
42 #include "clang/Sema/ScopeInfo.h"
43 #include "clang/Sema/SemaInternal.h"
44 #include "clang/Sema/Template.h"
45 #include "llvm/ADT/SmallString.h"
46 #include "llvm/ADT/Triple.h"
51 using namespace clang;
54 Sema::DeclGroupPtrTy Sema::ConvertDeclToDeclGroup(Decl *Ptr, Decl *OwnedType) {
56 Decl *Group[2] = { OwnedType, Ptr };
57 return DeclGroupPtrTy::make(DeclGroupRef::Create(Context, Group, 2));
60 return DeclGroupPtrTy::make(DeclGroupRef(Ptr));
65 class TypeNameValidatorCCC : public CorrectionCandidateCallback {
67 TypeNameValidatorCCC(bool AllowInvalid, bool WantClass = false,
68 bool AllowTemplates = false,
69 bool AllowNonTemplates = true)
70 : AllowInvalidDecl(AllowInvalid), WantClassName(WantClass),
71 AllowTemplates(AllowTemplates), AllowNonTemplates(AllowNonTemplates) {
72 WantExpressionKeywords = false;
73 WantCXXNamedCasts = false;
74 WantRemainingKeywords = false;
77 bool ValidateCandidate(const TypoCorrection &candidate) override {
78 if (NamedDecl *ND = candidate.getCorrectionDecl()) {
79 if (!AllowInvalidDecl && ND->isInvalidDecl())
82 if (getAsTypeTemplateDecl(ND))
83 return AllowTemplates;
85 bool IsType = isa<TypeDecl>(ND) || isa<ObjCInterfaceDecl>(ND);
89 if (AllowNonTemplates)
92 // An injected-class-name of a class template (specialization) is valid
93 // as a template or as a non-template.
95 auto *RD = dyn_cast<CXXRecordDecl>(ND);
96 if (!RD || !RD->isInjectedClassName())
98 RD = cast<CXXRecordDecl>(RD->getDeclContext());
99 return RD->getDescribedClassTemplate() ||
100 isa<ClassTemplateSpecializationDecl>(RD);
106 return !WantClassName && candidate.isKeyword();
110 bool AllowInvalidDecl;
113 bool AllowNonTemplates;
116 } // end anonymous namespace
118 /// Determine whether the token kind starts a simple-type-specifier.
119 bool Sema::isSimpleTypeSpecifier(tok::TokenKind Kind) const {
121 // FIXME: Take into account the current language when deciding whether a
122 // token kind is a valid type specifier
125 case tok::kw___int64:
126 case tok::kw___int128:
128 case tok::kw_unsigned:
135 case tok::kw__Float16:
136 case tok::kw___float128:
137 case tok::kw_wchar_t:
139 case tok::kw___underlying_type:
140 case tok::kw___auto_type:
143 case tok::annot_typename:
144 case tok::kw_char16_t:
145 case tok::kw_char32_t:
147 case tok::annot_decltype:
148 case tok::kw_decltype:
149 return getLangOpts().CPlusPlus;
151 case tok::kw_char8_t:
152 return getLangOpts().Char8;
162 enum class UnqualifiedTypeNameLookupResult {
167 } // end anonymous namespace
169 /// Tries to perform unqualified lookup of the type decls in bases for
171 /// \return \a NotFound if no any decls is found, \a FoundNotType if found not a
172 /// type decl, \a FoundType if only type decls are found.
173 static UnqualifiedTypeNameLookupResult
174 lookupUnqualifiedTypeNameInBase(Sema &S, const IdentifierInfo &II,
175 SourceLocation NameLoc,
176 const CXXRecordDecl *RD) {
177 if (!RD->hasDefinition())
178 return UnqualifiedTypeNameLookupResult::NotFound;
179 // Look for type decls in base classes.
180 UnqualifiedTypeNameLookupResult FoundTypeDecl =
181 UnqualifiedTypeNameLookupResult::NotFound;
182 for (const auto &Base : RD->bases()) {
183 const CXXRecordDecl *BaseRD = nullptr;
184 if (auto *BaseTT = Base.getType()->getAs<TagType>())
185 BaseRD = BaseTT->getAsCXXRecordDecl();
186 else if (auto *TST = Base.getType()->getAs<TemplateSpecializationType>()) {
187 // Look for type decls in dependent base classes that have known primary
189 if (!TST || !TST->isDependentType())
191 auto *TD = TST->getTemplateName().getAsTemplateDecl();
194 if (auto *BasePrimaryTemplate =
195 dyn_cast_or_null<CXXRecordDecl>(TD->getTemplatedDecl())) {
196 if (BasePrimaryTemplate->getCanonicalDecl() != RD->getCanonicalDecl())
197 BaseRD = BasePrimaryTemplate;
198 else if (auto *CTD = dyn_cast<ClassTemplateDecl>(TD)) {
199 if (const ClassTemplatePartialSpecializationDecl *PS =
200 CTD->findPartialSpecialization(Base.getType()))
201 if (PS->getCanonicalDecl() != RD->getCanonicalDecl())
207 for (NamedDecl *ND : BaseRD->lookup(&II)) {
208 if (!isa<TypeDecl>(ND))
209 return UnqualifiedTypeNameLookupResult::FoundNonType;
210 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
212 if (FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound) {
213 switch (lookupUnqualifiedTypeNameInBase(S, II, NameLoc, BaseRD)) {
214 case UnqualifiedTypeNameLookupResult::FoundNonType:
215 return UnqualifiedTypeNameLookupResult::FoundNonType;
216 case UnqualifiedTypeNameLookupResult::FoundType:
217 FoundTypeDecl = UnqualifiedTypeNameLookupResult::FoundType;
219 case UnqualifiedTypeNameLookupResult::NotFound:
226 return FoundTypeDecl;
229 static ParsedType recoverFromTypeInKnownDependentBase(Sema &S,
230 const IdentifierInfo &II,
231 SourceLocation NameLoc) {
232 // Lookup in the parent class template context, if any.
233 const CXXRecordDecl *RD = nullptr;
234 UnqualifiedTypeNameLookupResult FoundTypeDecl =
235 UnqualifiedTypeNameLookupResult::NotFound;
236 for (DeclContext *DC = S.CurContext;
237 DC && FoundTypeDecl == UnqualifiedTypeNameLookupResult::NotFound;
238 DC = DC->getParent()) {
239 // Look for type decls in dependent base classes that have known primary
241 RD = dyn_cast<CXXRecordDecl>(DC);
242 if (RD && RD->getDescribedClassTemplate())
243 FoundTypeDecl = lookupUnqualifiedTypeNameInBase(S, II, NameLoc, RD);
245 if (FoundTypeDecl != UnqualifiedTypeNameLookupResult::FoundType)
248 // We found some types in dependent base classes. Recover as if the user
249 // wrote 'typename MyClass::II' instead of 'II'. We'll fully resolve the
250 // lookup during template instantiation.
251 S.Diag(NameLoc, diag::ext_found_via_dependent_bases_lookup) << &II;
253 ASTContext &Context = S.Context;
254 auto *NNS = NestedNameSpecifier::Create(Context, nullptr, false,
255 cast<Type>(Context.getRecordType(RD)));
256 QualType T = Context.getDependentNameType(ETK_Typename, NNS, &II);
259 SS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
261 TypeLocBuilder Builder;
262 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
263 DepTL.setNameLoc(NameLoc);
264 DepTL.setElaboratedKeywordLoc(SourceLocation());
265 DepTL.setQualifierLoc(SS.getWithLocInContext(Context));
266 return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
269 /// If the identifier refers to a type name within this scope,
270 /// return the declaration of that type.
272 /// This routine performs ordinary name lookup of the identifier II
273 /// within the given scope, with optional C++ scope specifier SS, to
274 /// determine whether the name refers to a type. If so, returns an
275 /// opaque pointer (actually a QualType) corresponding to that
276 /// type. Otherwise, returns NULL.
277 ParsedType Sema::getTypeName(const IdentifierInfo &II, SourceLocation NameLoc,
278 Scope *S, CXXScopeSpec *SS,
279 bool isClassName, bool HasTrailingDot,
280 ParsedType ObjectTypePtr,
281 bool IsCtorOrDtorName,
282 bool WantNontrivialTypeSourceInfo,
283 bool IsClassTemplateDeductionContext,
284 IdentifierInfo **CorrectedII) {
285 // FIXME: Consider allowing this outside C++1z mode as an extension.
286 bool AllowDeducedTemplate = IsClassTemplateDeductionContext &&
287 getLangOpts().CPlusPlus17 && !IsCtorOrDtorName &&
288 !isClassName && !HasTrailingDot;
290 // Determine where we will perform name lookup.
291 DeclContext *LookupCtx = nullptr;
293 QualType ObjectType = ObjectTypePtr.get();
294 if (ObjectType->isRecordType())
295 LookupCtx = computeDeclContext(ObjectType);
296 } else if (SS && SS->isNotEmpty()) {
297 LookupCtx = computeDeclContext(*SS, false);
300 if (isDependentScopeSpecifier(*SS)) {
302 // A qualified-id that refers to a type and in which the
303 // nested-name-specifier depends on a template-parameter (14.6.2)
304 // shall be prefixed by the keyword typename to indicate that the
305 // qualified-id denotes a type, forming an
306 // elaborated-type-specifier (7.1.5.3).
308 // We therefore do not perform any name lookup if the result would
309 // refer to a member of an unknown specialization.
310 if (!isClassName && !IsCtorOrDtorName)
313 // We know from the grammar that this name refers to a type,
314 // so build a dependent node to describe the type.
315 if (WantNontrivialTypeSourceInfo)
316 return ActOnTypenameType(S, SourceLocation(), *SS, II, NameLoc).get();
318 NestedNameSpecifierLoc QualifierLoc = SS->getWithLocInContext(Context);
319 QualType T = CheckTypenameType(ETK_None, SourceLocation(), QualifierLoc,
321 return ParsedType::make(T);
327 if (!LookupCtx->isDependentContext() &&
328 RequireCompleteDeclContext(*SS, LookupCtx))
332 // FIXME: LookupNestedNameSpecifierName isn't the right kind of
333 // lookup for class-names.
334 LookupNameKind Kind = isClassName ? LookupNestedNameSpecifierName :
336 LookupResult Result(*this, &II, NameLoc, Kind);
338 // Perform "qualified" name lookup into the declaration context we
339 // computed, which is either the type of the base of a member access
340 // expression or the declaration context associated with a prior
341 // nested-name-specifier.
342 LookupQualifiedName(Result, LookupCtx);
344 if (ObjectTypePtr && Result.empty()) {
345 // C++ [basic.lookup.classref]p3:
346 // If the unqualified-id is ~type-name, the type-name is looked up
347 // in the context of the entire postfix-expression. If the type T of
348 // the object expression is of a class type C, the type-name is also
349 // looked up in the scope of class C. At least one of the lookups shall
350 // find a name that refers to (possibly cv-qualified) T.
351 LookupName(Result, S);
354 // Perform unqualified name lookup.
355 LookupName(Result, S);
357 // For unqualified lookup in a class template in MSVC mode, look into
358 // dependent base classes where the primary class template is known.
359 if (Result.empty() && getLangOpts().MSVCCompat && (!SS || SS->isEmpty())) {
360 if (ParsedType TypeInBase =
361 recoverFromTypeInKnownDependentBase(*this, II, NameLoc))
366 NamedDecl *IIDecl = nullptr;
367 switch (Result.getResultKind()) {
368 case LookupResult::NotFound:
369 case LookupResult::NotFoundInCurrentInstantiation:
371 TypoCorrection Correction =
372 CorrectTypo(Result.getLookupNameInfo(), Kind, S, SS,
373 llvm::make_unique<TypeNameValidatorCCC>(
374 true, isClassName, AllowDeducedTemplate),
376 IdentifierInfo *NewII = Correction.getCorrectionAsIdentifierInfo();
378 bool MemberOfUnknownSpecialization;
379 UnqualifiedId TemplateName;
380 TemplateName.setIdentifier(NewII, NameLoc);
381 NestedNameSpecifier *NNS = Correction.getCorrectionSpecifier();
382 CXXScopeSpec NewSS, *NewSSPtr = SS;
384 NewSS.MakeTrivial(Context, NNS, SourceRange(NameLoc));
387 if (Correction && (NNS || NewII != &II) &&
388 // Ignore a correction to a template type as the to-be-corrected
389 // identifier is not a template (typo correction for template names
390 // is handled elsewhere).
391 !(getLangOpts().CPlusPlus && NewSSPtr &&
392 isTemplateName(S, *NewSSPtr, false, TemplateName, nullptr, false,
393 Template, MemberOfUnknownSpecialization))) {
394 ParsedType Ty = getTypeName(*NewII, NameLoc, S, NewSSPtr,
395 isClassName, HasTrailingDot, ObjectTypePtr,
397 WantNontrivialTypeSourceInfo,
398 IsClassTemplateDeductionContext);
400 diagnoseTypo(Correction,
401 PDiag(diag::err_unknown_type_or_class_name_suggest)
402 << Result.getLookupName() << isClassName);
404 SS->MakeTrivial(Context, NNS, SourceRange(NameLoc));
405 *CorrectedII = NewII;
410 // If typo correction failed or was not performed, fall through
412 case LookupResult::FoundOverloaded:
413 case LookupResult::FoundUnresolvedValue:
414 Result.suppressDiagnostics();
417 case LookupResult::Ambiguous:
418 // Recover from type-hiding ambiguities by hiding the type. We'll
419 // do the lookup again when looking for an object, and we can
420 // diagnose the error then. If we don't do this, then the error
421 // about hiding the type will be immediately followed by an error
422 // that only makes sense if the identifier was treated like a type.
423 if (Result.getAmbiguityKind() == LookupResult::AmbiguousTagHiding) {
424 Result.suppressDiagnostics();
428 // Look to see if we have a type anywhere in the list of results.
429 for (LookupResult::iterator Res = Result.begin(), ResEnd = Result.end();
430 Res != ResEnd; ++Res) {
431 if (isa<TypeDecl>(*Res) || isa<ObjCInterfaceDecl>(*Res) ||
432 (AllowDeducedTemplate && getAsTypeTemplateDecl(*Res))) {
434 (*Res)->getLocation().getRawEncoding() <
435 IIDecl->getLocation().getRawEncoding())
441 // None of the entities we found is a type, so there is no way
442 // to even assume that the result is a type. In this case, don't
443 // complain about the ambiguity. The parser will either try to
444 // perform this lookup again (e.g., as an object name), which
445 // will produce the ambiguity, or will complain that it expected
447 Result.suppressDiagnostics();
451 // We found a type within the ambiguous lookup; diagnose the
452 // ambiguity and then return that type. This might be the right
453 // answer, or it might not be, but it suppresses any attempt to
454 // perform the name lookup again.
457 case LookupResult::Found:
458 IIDecl = Result.getFoundDecl();
462 assert(IIDecl && "Didn't find decl");
465 if (TypeDecl *TD = dyn_cast<TypeDecl>(IIDecl)) {
466 // C++ [class.qual]p2: A lookup that would find the injected-class-name
467 // instead names the constructors of the class, except when naming a class.
468 // This is ill-formed when we're not actually forming a ctor or dtor name.
469 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
470 auto *FoundRD = dyn_cast<CXXRecordDecl>(TD);
471 if (!isClassName && !IsCtorOrDtorName && LookupRD && FoundRD &&
472 FoundRD->isInjectedClassName() &&
473 declaresSameEntity(LookupRD, cast<Decl>(FoundRD->getParent())))
474 Diag(NameLoc, diag::err_out_of_line_qualified_id_type_names_constructor)
477 DiagnoseUseOfDecl(IIDecl, NameLoc);
479 T = Context.getTypeDeclType(TD);
480 MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
481 } else if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(IIDecl)) {
482 (void)DiagnoseUseOfDecl(IDecl, NameLoc);
484 T = Context.getObjCInterfaceType(IDecl);
485 } else if (AllowDeducedTemplate) {
486 if (auto *TD = getAsTypeTemplateDecl(IIDecl))
487 T = Context.getDeducedTemplateSpecializationType(TemplateName(TD),
492 // If it's not plausibly a type, suppress diagnostics.
493 Result.suppressDiagnostics();
497 // NOTE: avoid constructing an ElaboratedType(Loc) if this is a
498 // constructor or destructor name (in such a case, the scope specifier
499 // will be attached to the enclosing Expr or Decl node).
500 if (SS && SS->isNotEmpty() && !IsCtorOrDtorName &&
501 !isa<ObjCInterfaceDecl>(IIDecl)) {
502 if (WantNontrivialTypeSourceInfo) {
503 // Construct a type with type-source information.
504 TypeLocBuilder Builder;
505 Builder.pushTypeSpec(T).setNameLoc(NameLoc);
507 T = getElaboratedType(ETK_None, *SS, T);
508 ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
509 ElabTL.setElaboratedKeywordLoc(SourceLocation());
510 ElabTL.setQualifierLoc(SS->getWithLocInContext(Context));
511 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
513 T = getElaboratedType(ETK_None, *SS, T);
517 return ParsedType::make(T);
520 // Builds a fake NNS for the given decl context.
521 static NestedNameSpecifier *
522 synthesizeCurrentNestedNameSpecifier(ASTContext &Context, DeclContext *DC) {
523 for (;; DC = DC->getLookupParent()) {
524 DC = DC->getPrimaryContext();
525 auto *ND = dyn_cast<NamespaceDecl>(DC);
526 if (ND && !ND->isInline() && !ND->isAnonymousNamespace())
527 return NestedNameSpecifier::Create(Context, nullptr, ND);
528 else if (auto *RD = dyn_cast<CXXRecordDecl>(DC))
529 return NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
530 RD->getTypeForDecl());
531 else if (isa<TranslationUnitDecl>(DC))
532 return NestedNameSpecifier::GlobalSpecifier(Context);
534 llvm_unreachable("something isn't in TU scope?");
537 /// Find the parent class with dependent bases of the innermost enclosing method
538 /// context. Do not look for enclosing CXXRecordDecls directly, or we will end
539 /// up allowing unqualified dependent type names at class-level, which MSVC
540 /// correctly rejects.
541 static const CXXRecordDecl *
542 findRecordWithDependentBasesOfEnclosingMethod(const DeclContext *DC) {
543 for (; DC && DC->isDependentContext(); DC = DC->getLookupParent()) {
544 DC = DC->getPrimaryContext();
545 if (const auto *MD = dyn_cast<CXXMethodDecl>(DC))
546 if (MD->getParent()->hasAnyDependentBases())
547 return MD->getParent();
552 ParsedType Sema::ActOnMSVCUnknownTypeName(const IdentifierInfo &II,
553 SourceLocation NameLoc,
554 bool IsTemplateTypeArg) {
555 assert(getLangOpts().MSVCCompat && "shouldn't be called in non-MSVC mode");
557 NestedNameSpecifier *NNS = nullptr;
558 if (IsTemplateTypeArg && getCurScope()->isTemplateParamScope()) {
559 // If we weren't able to parse a default template argument, delay lookup
560 // until instantiation time by making a non-dependent DependentTypeName. We
561 // pretend we saw a NestedNameSpecifier referring to the current scope, and
562 // lookup is retried.
563 // FIXME: This hurts our diagnostic quality, since we get errors like "no
564 // type named 'Foo' in 'current_namespace'" when the user didn't write any
566 NNS = synthesizeCurrentNestedNameSpecifier(Context, CurContext);
567 Diag(NameLoc, diag::ext_ms_delayed_template_argument) << &II;
568 } else if (const CXXRecordDecl *RD =
569 findRecordWithDependentBasesOfEnclosingMethod(CurContext)) {
570 // Build a DependentNameType that will perform lookup into RD at
571 // instantiation time.
572 NNS = NestedNameSpecifier::Create(Context, nullptr, RD->isTemplateDecl(),
573 RD->getTypeForDecl());
575 // Diagnose that this identifier was undeclared, and retry the lookup during
576 // template instantiation.
577 Diag(NameLoc, diag::ext_undeclared_unqual_id_with_dependent_base) << &II
580 // This is not a situation that we should recover from.
584 QualType T = Context.getDependentNameType(ETK_None, NNS, &II);
586 // Build type location information. We synthesized the qualifier, so we have
587 // to build a fake NestedNameSpecifierLoc.
588 NestedNameSpecifierLocBuilder NNSLocBuilder;
589 NNSLocBuilder.MakeTrivial(Context, NNS, SourceRange(NameLoc));
590 NestedNameSpecifierLoc QualifierLoc = NNSLocBuilder.getWithLocInContext(Context);
592 TypeLocBuilder Builder;
593 DependentNameTypeLoc DepTL = Builder.push<DependentNameTypeLoc>(T);
594 DepTL.setNameLoc(NameLoc);
595 DepTL.setElaboratedKeywordLoc(SourceLocation());
596 DepTL.setQualifierLoc(QualifierLoc);
597 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
600 /// isTagName() - This method is called *for error recovery purposes only*
601 /// to determine if the specified name is a valid tag name ("struct foo"). If
602 /// so, this returns the TST for the tag corresponding to it (TST_enum,
603 /// TST_union, TST_struct, TST_interface, TST_class). This is used to diagnose
604 /// cases in C where the user forgot to specify the tag.
605 DeclSpec::TST Sema::isTagName(IdentifierInfo &II, Scope *S) {
606 // Do a tag name lookup in this scope.
607 LookupResult R(*this, &II, SourceLocation(), LookupTagName);
608 LookupName(R, S, false);
609 R.suppressDiagnostics();
610 if (R.getResultKind() == LookupResult::Found)
611 if (const TagDecl *TD = R.getAsSingle<TagDecl>()) {
612 switch (TD->getTagKind()) {
613 case TTK_Struct: return DeclSpec::TST_struct;
614 case TTK_Interface: return DeclSpec::TST_interface;
615 case TTK_Union: return DeclSpec::TST_union;
616 case TTK_Class: return DeclSpec::TST_class;
617 case TTK_Enum: return DeclSpec::TST_enum;
621 return DeclSpec::TST_unspecified;
624 /// isMicrosoftMissingTypename - In Microsoft mode, within class scope,
625 /// if a CXXScopeSpec's type is equal to the type of one of the base classes
626 /// then downgrade the missing typename error to a warning.
627 /// This is needed for MSVC compatibility; Example:
629 /// template<class T> class A {
631 /// typedef int TYPE;
633 /// template<class T> class B : public A<T> {
635 /// A<T>::TYPE a; // no typename required because A<T> is a base class.
638 bool Sema::isMicrosoftMissingTypename(const CXXScopeSpec *SS, Scope *S) {
639 if (CurContext->isRecord()) {
640 if (SS->getScopeRep()->getKind() == NestedNameSpecifier::Super)
643 const Type *Ty = SS->getScopeRep()->getAsType();
645 CXXRecordDecl *RD = cast<CXXRecordDecl>(CurContext);
646 for (const auto &Base : RD->bases())
647 if (Ty && Context.hasSameUnqualifiedType(QualType(Ty, 1), Base.getType()))
649 return S->isFunctionPrototypeScope();
651 return CurContext->isFunctionOrMethod() || S->isFunctionPrototypeScope();
654 void Sema::DiagnoseUnknownTypeName(IdentifierInfo *&II,
655 SourceLocation IILoc,
658 ParsedType &SuggestedType,
659 bool IsTemplateName) {
660 // Don't report typename errors for editor placeholders.
661 if (II->isEditorPlaceholder())
663 // We don't have anything to suggest (yet).
664 SuggestedType = nullptr;
666 // There may have been a typo in the name of the type. Look up typo
667 // results, in case we have something that we can suggest.
668 if (TypoCorrection Corrected =
669 CorrectTypo(DeclarationNameInfo(II, IILoc), LookupOrdinaryName, S, SS,
670 llvm::make_unique<TypeNameValidatorCCC>(
671 false, false, IsTemplateName, !IsTemplateName),
672 CTK_ErrorRecovery)) {
673 // FIXME: Support error recovery for the template-name case.
674 bool CanRecover = !IsTemplateName;
675 if (Corrected.isKeyword()) {
676 // We corrected to a keyword.
677 diagnoseTypo(Corrected,
678 PDiag(IsTemplateName ? diag::err_no_template_suggest
679 : diag::err_unknown_typename_suggest)
681 II = Corrected.getCorrectionAsIdentifierInfo();
683 // We found a similarly-named type or interface; suggest that.
684 if (!SS || !SS->isSet()) {
685 diagnoseTypo(Corrected,
686 PDiag(IsTemplateName ? diag::err_no_template_suggest
687 : diag::err_unknown_typename_suggest)
689 } else if (DeclContext *DC = computeDeclContext(*SS, false)) {
690 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
691 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
692 II->getName().equals(CorrectedStr);
693 diagnoseTypo(Corrected,
695 ? diag::err_no_member_template_suggest
696 : diag::err_unknown_nested_typename_suggest)
697 << II << DC << DroppedSpecifier << SS->getRange(),
700 llvm_unreachable("could not have corrected a typo here");
707 if (Corrected.getCorrectionSpecifier())
708 tmpSS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(),
710 // FIXME: Support class template argument deduction here.
712 getTypeName(*Corrected.getCorrectionAsIdentifierInfo(), IILoc, S,
713 tmpSS.isSet() ? &tmpSS : SS, false, false, nullptr,
714 /*IsCtorOrDtorName=*/false,
715 /*NonTrivialTypeSourceInfo=*/true);
720 if (getLangOpts().CPlusPlus && !IsTemplateName) {
721 // See if II is a class template that the user forgot to pass arguments to.
723 Name.setIdentifier(II, IILoc);
724 CXXScopeSpec EmptySS;
725 TemplateTy TemplateResult;
726 bool MemberOfUnknownSpecialization;
727 if (isTemplateName(S, SS ? *SS : EmptySS, /*hasTemplateKeyword=*/false,
728 Name, nullptr, true, TemplateResult,
729 MemberOfUnknownSpecialization) == TNK_Type_template) {
730 diagnoseMissingTemplateArguments(TemplateResult.get(), IILoc);
735 // FIXME: Should we move the logic that tries to recover from a missing tag
736 // (struct, union, enum) from Parser::ParseImplicitInt here, instead?
738 if (!SS || (!SS->isSet() && !SS->isInvalid()))
739 Diag(IILoc, IsTemplateName ? diag::err_no_template
740 : diag::err_unknown_typename)
742 else if (DeclContext *DC = computeDeclContext(*SS, false))
743 Diag(IILoc, IsTemplateName ? diag::err_no_member_template
744 : diag::err_typename_nested_not_found)
745 << II << DC << SS->getRange();
746 else if (isDependentScopeSpecifier(*SS)) {
747 unsigned DiagID = diag::err_typename_missing;
748 if (getLangOpts().MSVCCompat && isMicrosoftMissingTypename(SS, S))
749 DiagID = diag::ext_typename_missing;
751 Diag(SS->getRange().getBegin(), DiagID)
752 << SS->getScopeRep() << II->getName()
753 << SourceRange(SS->getRange().getBegin(), IILoc)
754 << FixItHint::CreateInsertion(SS->getRange().getBegin(), "typename ");
755 SuggestedType = ActOnTypenameType(S, SourceLocation(),
756 *SS, *II, IILoc).get();
758 assert(SS && SS->isInvalid() &&
759 "Invalid scope specifier has already been diagnosed");
763 /// Determine whether the given result set contains either a type name
765 static bool isResultTypeOrTemplate(LookupResult &R, const Token &NextToken) {
766 bool CheckTemplate = R.getSema().getLangOpts().CPlusPlus &&
767 NextToken.is(tok::less);
769 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
770 if (isa<TypeDecl>(*I) || isa<ObjCInterfaceDecl>(*I))
773 if (CheckTemplate && isa<TemplateDecl>(*I))
780 static bool isTagTypeWithMissingTag(Sema &SemaRef, LookupResult &Result,
781 Scope *S, CXXScopeSpec &SS,
782 IdentifierInfo *&Name,
783 SourceLocation NameLoc) {
784 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupTagName);
785 SemaRef.LookupParsedName(R, S, &SS);
786 if (TagDecl *Tag = R.getAsSingle<TagDecl>()) {
787 StringRef FixItTagName;
788 switch (Tag->getTagKind()) {
790 FixItTagName = "class ";
794 FixItTagName = "enum ";
798 FixItTagName = "struct ";
802 FixItTagName = "__interface ";
806 FixItTagName = "union ";
810 StringRef TagName = FixItTagName.drop_back();
811 SemaRef.Diag(NameLoc, diag::err_use_of_tag_name_without_tag)
812 << Name << TagName << SemaRef.getLangOpts().CPlusPlus
813 << FixItHint::CreateInsertion(NameLoc, FixItTagName);
815 for (LookupResult::iterator I = Result.begin(), IEnd = Result.end();
817 SemaRef.Diag((*I)->getLocation(), diag::note_decl_hiding_tag_type)
820 // Replace lookup results with just the tag decl.
821 Result.clear(Sema::LookupTagName);
822 SemaRef.LookupParsedName(Result, S, &SS);
829 /// Build a ParsedType for a simple-type-specifier with a nested-name-specifier.
830 static ParsedType buildNestedType(Sema &S, CXXScopeSpec &SS,
831 QualType T, SourceLocation NameLoc) {
832 ASTContext &Context = S.Context;
834 TypeLocBuilder Builder;
835 Builder.pushTypeSpec(T).setNameLoc(NameLoc);
837 T = S.getElaboratedType(ETK_None, SS, T);
838 ElaboratedTypeLoc ElabTL = Builder.push<ElaboratedTypeLoc>(T);
839 ElabTL.setElaboratedKeywordLoc(SourceLocation());
840 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
841 return S.CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
844 Sema::NameClassification
845 Sema::ClassifyName(Scope *S, CXXScopeSpec &SS, IdentifierInfo *&Name,
846 SourceLocation NameLoc, const Token &NextToken,
847 bool IsAddressOfOperand,
848 std::unique_ptr<CorrectionCandidateCallback> CCC) {
849 DeclarationNameInfo NameInfo(Name, NameLoc);
850 ObjCMethodDecl *CurMethod = getCurMethodDecl();
852 if (NextToken.is(tok::coloncolon)) {
853 NestedNameSpecInfo IdInfo(Name, NameLoc, NextToken.getLocation());
854 BuildCXXNestedNameSpecifier(S, IdInfo, false, SS, nullptr, false);
855 } else if (getLangOpts().CPlusPlus && SS.isSet() &&
856 isCurrentClassName(*Name, S, &SS)) {
857 // Per [class.qual]p2, this names the constructors of SS, not the
858 // injected-class-name. We don't have a classification for that.
859 // There's not much point caching this result, since the parser
860 // will reject it later.
861 return NameClassification::Unknown();
864 LookupResult Result(*this, Name, NameLoc, LookupOrdinaryName);
865 LookupParsedName(Result, S, &SS, !CurMethod);
867 // For unqualified lookup in a class template in MSVC mode, look into
868 // dependent base classes where the primary class template is known.
869 if (Result.empty() && SS.isEmpty() && getLangOpts().MSVCCompat) {
870 if (ParsedType TypeInBase =
871 recoverFromTypeInKnownDependentBase(*this, *Name, NameLoc))
875 // Perform lookup for Objective-C instance variables (including automatically
876 // synthesized instance variables), if we're in an Objective-C method.
877 // FIXME: This lookup really, really needs to be folded in to the normal
878 // unqualified lookup mechanism.
879 if (!SS.isSet() && CurMethod && !isResultTypeOrTemplate(Result, NextToken)) {
880 ExprResult E = LookupInObjCMethod(Result, S, Name, true);
881 if (E.get() || E.isInvalid())
885 bool SecondTry = false;
886 bool IsFilteredTemplateName = false;
889 switch (Result.getResultKind()) {
890 case LookupResult::NotFound:
891 // If an unqualified-id is followed by a '(', then we have a function
893 if (!SS.isSet() && NextToken.is(tok::l_paren)) {
894 // In C++, this is an ADL-only call.
896 if (getLangOpts().CPlusPlus)
897 return BuildDeclarationNameExpr(SS, Result, /*ADL=*/true);
900 // If the expression that precedes the parenthesized argument list in a
901 // function call consists solely of an identifier, and if no
902 // declaration is visible for this identifier, the identifier is
903 // implicitly declared exactly as if, in the innermost block containing
904 // the function call, the declaration
906 // extern int identifier ();
910 // We also allow this in C99 as an extension.
911 if (NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *Name, S)) {
913 Result.resolveKind();
914 return BuildDeclarationNameExpr(SS, Result, /*ADL=*/false);
918 // In C, we first see whether there is a tag type by the same name, in
919 // which case it's likely that the user just forgot to write "enum",
920 // "struct", or "union".
921 if (!getLangOpts().CPlusPlus && !SecondTry &&
922 isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
926 // Perform typo correction to determine if there is another name that is
927 // close to this name.
928 if (!SecondTry && CCC) {
930 if (TypoCorrection Corrected = CorrectTypo(Result.getLookupNameInfo(),
931 Result.getLookupKind(), S,
933 CTK_ErrorRecovery)) {
934 unsigned UnqualifiedDiag = diag::err_undeclared_var_use_suggest;
935 unsigned QualifiedDiag = diag::err_no_member_suggest;
937 NamedDecl *FirstDecl = Corrected.getFoundDecl();
938 NamedDecl *UnderlyingFirstDecl = Corrected.getCorrectionDecl();
939 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
940 UnderlyingFirstDecl && isa<TemplateDecl>(UnderlyingFirstDecl)) {
941 UnqualifiedDiag = diag::err_no_template_suggest;
942 QualifiedDiag = diag::err_no_member_template_suggest;
943 } else if (UnderlyingFirstDecl &&
944 (isa<TypeDecl>(UnderlyingFirstDecl) ||
945 isa<ObjCInterfaceDecl>(UnderlyingFirstDecl) ||
946 isa<ObjCCompatibleAliasDecl>(UnderlyingFirstDecl))) {
947 UnqualifiedDiag = diag::err_unknown_typename_suggest;
948 QualifiedDiag = diag::err_unknown_nested_typename_suggest;
952 diagnoseTypo(Corrected, PDiag(UnqualifiedDiag) << Name);
953 } else {// FIXME: is this even reachable? Test it.
954 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
955 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
956 Name->getName().equals(CorrectedStr);
957 diagnoseTypo(Corrected, PDiag(QualifiedDiag)
958 << Name << computeDeclContext(SS, false)
959 << DroppedSpecifier << SS.getRange());
962 // Update the name, so that the caller has the new name.
963 Name = Corrected.getCorrectionAsIdentifierInfo();
965 // Typo correction corrected to a keyword.
966 if (Corrected.isKeyword())
969 // Also update the LookupResult...
970 // FIXME: This should probably go away at some point
972 Result.setLookupName(Corrected.getCorrection());
974 Result.addDecl(FirstDecl);
976 // If we found an Objective-C instance variable, let
977 // LookupInObjCMethod build the appropriate expression to
978 // reference the ivar.
979 // FIXME: This is a gross hack.
980 if (ObjCIvarDecl *Ivar = Result.getAsSingle<ObjCIvarDecl>()) {
982 ExprResult E(LookupInObjCMethod(Result, S, Ivar->getIdentifier()));
990 // We failed to correct; just fall through and let the parser deal with it.
991 Result.suppressDiagnostics();
992 return NameClassification::Unknown();
994 case LookupResult::NotFoundInCurrentInstantiation: {
995 // We performed name lookup into the current instantiation, and there were
996 // dependent bases, so we treat this result the same way as any other
997 // dependent nested-name-specifier.
1000 // A name used in a template declaration or definition and that is
1001 // dependent on a template-parameter is assumed not to name a type
1002 // unless the applicable name lookup finds a type name or the name is
1003 // qualified by the keyword typename.
1005 // FIXME: If the next token is '<', we might want to ask the parser to
1006 // perform some heroics to see if we actually have a
1007 // template-argument-list, which would indicate a missing 'template'
1009 return ActOnDependentIdExpression(SS, /*TemplateKWLoc=*/SourceLocation(),
1010 NameInfo, IsAddressOfOperand,
1011 /*TemplateArgs=*/nullptr);
1014 case LookupResult::Found:
1015 case LookupResult::FoundOverloaded:
1016 case LookupResult::FoundUnresolvedValue:
1019 case LookupResult::Ambiguous:
1020 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
1021 hasAnyAcceptableTemplateNames(Result)) {
1022 // C++ [temp.local]p3:
1023 // A lookup that finds an injected-class-name (10.2) can result in an
1024 // ambiguity in certain cases (for example, if it is found in more than
1025 // one base class). If all of the injected-class-names that are found
1026 // refer to specializations of the same class template, and if the name
1027 // is followed by a template-argument-list, the reference refers to the
1028 // class template itself and not a specialization thereof, and is not
1031 // This filtering can make an ambiguous result into an unambiguous one,
1032 // so try again after filtering out template names.
1033 FilterAcceptableTemplateNames(Result);
1034 if (!Result.isAmbiguous()) {
1035 IsFilteredTemplateName = true;
1040 // Diagnose the ambiguity and return an error.
1041 return NameClassification::Error();
1044 if (getLangOpts().CPlusPlus && NextToken.is(tok::less) &&
1045 (IsFilteredTemplateName || hasAnyAcceptableTemplateNames(Result))) {
1046 // C++ [temp.names]p3:
1047 // After name lookup (3.4) finds that a name is a template-name or that
1048 // an operator-function-id or a literal- operator-id refers to a set of
1049 // overloaded functions any member of which is a function template if
1050 // this is followed by a <, the < is always taken as the delimiter of a
1051 // template-argument-list and never as the less-than operator.
1052 if (!IsFilteredTemplateName)
1053 FilterAcceptableTemplateNames(Result);
1055 if (!Result.empty()) {
1056 bool IsFunctionTemplate;
1058 TemplateName Template;
1059 if (Result.end() - Result.begin() > 1) {
1060 IsFunctionTemplate = true;
1061 Template = Context.getOverloadedTemplateName(Result.begin(),
1065 = cast<TemplateDecl>((*Result.begin())->getUnderlyingDecl());
1066 IsFunctionTemplate = isa<FunctionTemplateDecl>(TD);
1067 IsVarTemplate = isa<VarTemplateDecl>(TD);
1069 if (SS.isSet() && !SS.isInvalid())
1070 Template = Context.getQualifiedTemplateName(SS.getScopeRep(),
1071 /*TemplateKeyword=*/false,
1074 Template = TemplateName(TD);
1077 if (IsFunctionTemplate) {
1078 // Function templates always go through overload resolution, at which
1079 // point we'll perform the various checks (e.g., accessibility) we need
1080 // to based on which function we selected.
1081 Result.suppressDiagnostics();
1083 return NameClassification::FunctionTemplate(Template);
1086 return IsVarTemplate ? NameClassification::VarTemplate(Template)
1087 : NameClassification::TypeTemplate(Template);
1091 NamedDecl *FirstDecl = (*Result.begin())->getUnderlyingDecl();
1092 if (TypeDecl *Type = dyn_cast<TypeDecl>(FirstDecl)) {
1093 DiagnoseUseOfDecl(Type, NameLoc);
1094 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
1095 QualType T = Context.getTypeDeclType(Type);
1096 if (SS.isNotEmpty())
1097 return buildNestedType(*this, SS, T, NameLoc);
1098 return ParsedType::make(T);
1101 ObjCInterfaceDecl *Class = dyn_cast<ObjCInterfaceDecl>(FirstDecl);
1103 // FIXME: It's unfortunate that we don't have a Type node for handling this.
1104 if (ObjCCompatibleAliasDecl *Alias =
1105 dyn_cast<ObjCCompatibleAliasDecl>(FirstDecl))
1106 Class = Alias->getClassInterface();
1110 DiagnoseUseOfDecl(Class, NameLoc);
1112 if (NextToken.is(tok::period)) {
1113 // Interface. <something> is parsed as a property reference expression.
1114 // Just return "unknown" as a fall-through for now.
1115 Result.suppressDiagnostics();
1116 return NameClassification::Unknown();
1119 QualType T = Context.getObjCInterfaceType(Class);
1120 return ParsedType::make(T);
1123 // We can have a type template here if we're classifying a template argument.
1124 if (isa<TemplateDecl>(FirstDecl) && !isa<FunctionTemplateDecl>(FirstDecl) &&
1125 !isa<VarTemplateDecl>(FirstDecl))
1126 return NameClassification::TypeTemplate(
1127 TemplateName(cast<TemplateDecl>(FirstDecl)));
1129 // Check for a tag type hidden by a non-type decl in a few cases where it
1130 // seems likely a type is wanted instead of the non-type that was found.
1131 bool NextIsOp = NextToken.isOneOf(tok::amp, tok::star);
1132 if ((NextToken.is(tok::identifier) ||
1134 FirstDecl->getUnderlyingDecl()->isFunctionOrFunctionTemplate())) &&
1135 isTagTypeWithMissingTag(*this, Result, S, SS, Name, NameLoc)) {
1136 TypeDecl *Type = Result.getAsSingle<TypeDecl>();
1137 DiagnoseUseOfDecl(Type, NameLoc);
1138 QualType T = Context.getTypeDeclType(Type);
1139 if (SS.isNotEmpty())
1140 return buildNestedType(*this, SS, T, NameLoc);
1141 return ParsedType::make(T);
1144 if (FirstDecl->isCXXClassMember())
1145 return BuildPossibleImplicitMemberExpr(SS, SourceLocation(), Result,
1148 bool ADL = UseArgumentDependentLookup(SS, Result, NextToken.is(tok::l_paren));
1149 return BuildDeclarationNameExpr(SS, Result, ADL);
1152 Sema::TemplateNameKindForDiagnostics
1153 Sema::getTemplateNameKindForDiagnostics(TemplateName Name) {
1154 auto *TD = Name.getAsTemplateDecl();
1156 return TemplateNameKindForDiagnostics::DependentTemplate;
1157 if (isa<ClassTemplateDecl>(TD))
1158 return TemplateNameKindForDiagnostics::ClassTemplate;
1159 if (isa<FunctionTemplateDecl>(TD))
1160 return TemplateNameKindForDiagnostics::FunctionTemplate;
1161 if (isa<VarTemplateDecl>(TD))
1162 return TemplateNameKindForDiagnostics::VarTemplate;
1163 if (isa<TypeAliasTemplateDecl>(TD))
1164 return TemplateNameKindForDiagnostics::AliasTemplate;
1165 if (isa<TemplateTemplateParmDecl>(TD))
1166 return TemplateNameKindForDiagnostics::TemplateTemplateParam;
1167 return TemplateNameKindForDiagnostics::DependentTemplate;
1170 // Determines the context to return to after temporarily entering a
1171 // context. This depends in an unnecessarily complicated way on the
1172 // exact ordering of callbacks from the parser.
1173 DeclContext *Sema::getContainingDC(DeclContext *DC) {
1175 // Functions defined inline within classes aren't parsed until we've
1176 // finished parsing the top-level class, so the top-level class is
1177 // the context we'll need to return to.
1178 // A Lambda call operator whose parent is a class must not be treated
1179 // as an inline member function. A Lambda can be used legally
1180 // either as an in-class member initializer or a default argument. These
1181 // are parsed once the class has been marked complete and so the containing
1182 // context would be the nested class (when the lambda is defined in one);
1183 // If the class is not complete, then the lambda is being used in an
1184 // ill-formed fashion (such as to specify the width of a bit-field, or
1185 // in an array-bound) - in which case we still want to return the
1186 // lexically containing DC (which could be a nested class).
1187 if (isa<FunctionDecl>(DC) && !isLambdaCallOperator(DC)) {
1188 DC = DC->getLexicalParent();
1190 // A function not defined within a class will always return to its
1192 if (!isa<CXXRecordDecl>(DC))
1195 // A C++ inline method/friend is parsed *after* the topmost class
1196 // it was declared in is fully parsed ("complete"); the topmost
1197 // class is the context we need to return to.
1198 while (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC->getLexicalParent()))
1201 // Return the declaration context of the topmost class the inline method is
1206 return DC->getLexicalParent();
1209 void Sema::PushDeclContext(Scope *S, DeclContext *DC) {
1210 assert(getContainingDC(DC) == CurContext &&
1211 "The next DeclContext should be lexically contained in the current one.");
1216 void Sema::PopDeclContext() {
1217 assert(CurContext && "DeclContext imbalance!");
1219 CurContext = getContainingDC(CurContext);
1220 assert(CurContext && "Popped translation unit!");
1223 Sema::SkippedDefinitionContext Sema::ActOnTagStartSkippedDefinition(Scope *S,
1225 // Unlike PushDeclContext, the context to which we return is not necessarily
1226 // the containing DC of TD, because the new context will be some pre-existing
1227 // TagDecl definition instead of a fresh one.
1228 auto Result = static_cast<SkippedDefinitionContext>(CurContext);
1229 CurContext = cast<TagDecl>(D)->getDefinition();
1230 assert(CurContext && "skipping definition of undefined tag");
1231 // Start lookups from the parent of the current context; we don't want to look
1232 // into the pre-existing complete definition.
1233 S->setEntity(CurContext->getLookupParent());
1237 void Sema::ActOnTagFinishSkippedDefinition(SkippedDefinitionContext Context) {
1238 CurContext = static_cast<decltype(CurContext)>(Context);
1241 /// EnterDeclaratorContext - Used when we must lookup names in the context
1242 /// of a declarator's nested name specifier.
1244 void Sema::EnterDeclaratorContext(Scope *S, DeclContext *DC) {
1245 // C++0x [basic.lookup.unqual]p13:
1246 // A name used in the definition of a static data member of class
1247 // X (after the qualified-id of the static member) is looked up as
1248 // if the name was used in a member function of X.
1249 // C++0x [basic.lookup.unqual]p14:
1250 // If a variable member of a namespace is defined outside of the
1251 // scope of its namespace then any name used in the definition of
1252 // the variable member (after the declarator-id) is looked up as
1253 // if the definition of the variable member occurred in its
1255 // Both of these imply that we should push a scope whose context
1256 // is the semantic context of the declaration. We can't use
1257 // PushDeclContext here because that context is not necessarily
1258 // lexically contained in the current context. Fortunately,
1259 // the containing scope should have the appropriate information.
1261 assert(!S->getEntity() && "scope already has entity");
1264 Scope *Ancestor = S->getParent();
1265 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1266 assert(Ancestor->getEntity() == CurContext && "ancestor context mismatch");
1273 void Sema::ExitDeclaratorContext(Scope *S) {
1274 assert(S->getEntity() == CurContext && "Context imbalance!");
1276 // Switch back to the lexical context. The safety of this is
1277 // enforced by an assert in EnterDeclaratorContext.
1278 Scope *Ancestor = S->getParent();
1279 while (!Ancestor->getEntity()) Ancestor = Ancestor->getParent();
1280 CurContext = Ancestor->getEntity();
1282 // We don't need to do anything with the scope, which is going to
1286 void Sema::ActOnReenterFunctionContext(Scope* S, Decl *D) {
1287 // We assume that the caller has already called
1288 // ActOnReenterTemplateScope so getTemplatedDecl() works.
1289 FunctionDecl *FD = D->getAsFunction();
1293 // Same implementation as PushDeclContext, but enters the context
1294 // from the lexical parent, rather than the top-level class.
1295 assert(CurContext == FD->getLexicalParent() &&
1296 "The next DeclContext should be lexically contained in the current one.");
1298 S->setEntity(CurContext);
1300 for (unsigned P = 0, NumParams = FD->getNumParams(); P < NumParams; ++P) {
1301 ParmVarDecl *Param = FD->getParamDecl(P);
1302 // If the parameter has an identifier, then add it to the scope
1303 if (Param->getIdentifier()) {
1305 IdResolver.AddDecl(Param);
1310 void Sema::ActOnExitFunctionContext() {
1311 // Same implementation as PopDeclContext, but returns to the lexical parent,
1312 // rather than the top-level class.
1313 assert(CurContext && "DeclContext imbalance!");
1314 CurContext = CurContext->getLexicalParent();
1315 assert(CurContext && "Popped translation unit!");
1318 /// Determine whether we allow overloading of the function
1319 /// PrevDecl with another declaration.
1321 /// This routine determines whether overloading is possible, not
1322 /// whether some new function is actually an overload. It will return
1323 /// true in C++ (where we can always provide overloads) or, as an
1324 /// extension, in C when the previous function is already an
1325 /// overloaded function declaration or has the "overloadable"
1327 static bool AllowOverloadingOfFunction(LookupResult &Previous,
1328 ASTContext &Context,
1329 const FunctionDecl *New) {
1330 if (Context.getLangOpts().CPlusPlus)
1333 if (Previous.getResultKind() == LookupResult::FoundOverloaded)
1336 return Previous.getResultKind() == LookupResult::Found &&
1337 (Previous.getFoundDecl()->hasAttr<OverloadableAttr>() ||
1338 New->hasAttr<OverloadableAttr>());
1341 /// Add this decl to the scope shadowed decl chains.
1342 void Sema::PushOnScopeChains(NamedDecl *D, Scope *S, bool AddToContext) {
1343 // Move up the scope chain until we find the nearest enclosing
1344 // non-transparent context. The declaration will be introduced into this
1346 while (S->getEntity() && S->getEntity()->isTransparentContext())
1349 // Add scoped declarations into their context, so that they can be
1350 // found later. Declarations without a context won't be inserted
1351 // into any context.
1353 CurContext->addDecl(D);
1355 // Out-of-line definitions shouldn't be pushed into scope in C++, unless they
1356 // are function-local declarations.
1357 if (getLangOpts().CPlusPlus && D->isOutOfLine() &&
1358 !D->getDeclContext()->getRedeclContext()->Equals(
1359 D->getLexicalDeclContext()->getRedeclContext()) &&
1360 !D->getLexicalDeclContext()->isFunctionOrMethod())
1363 // Template instantiations should also not be pushed into scope.
1364 if (isa<FunctionDecl>(D) &&
1365 cast<FunctionDecl>(D)->isFunctionTemplateSpecialization())
1368 // If this replaces anything in the current scope,
1369 IdentifierResolver::iterator I = IdResolver.begin(D->getDeclName()),
1370 IEnd = IdResolver.end();
1371 for (; I != IEnd; ++I) {
1372 if (S->isDeclScope(*I) && D->declarationReplaces(*I)) {
1374 IdResolver.RemoveDecl(*I);
1376 // Should only need to replace one decl.
1383 if (isa<LabelDecl>(D) && !cast<LabelDecl>(D)->isGnuLocal()) {
1384 // Implicitly-generated labels may end up getting generated in an order that
1385 // isn't strictly lexical, which breaks name lookup. Be careful to insert
1386 // the label at the appropriate place in the identifier chain.
1387 for (I = IdResolver.begin(D->getDeclName()); I != IEnd; ++I) {
1388 DeclContext *IDC = (*I)->getLexicalDeclContext()->getRedeclContext();
1389 if (IDC == CurContext) {
1390 if (!S->isDeclScope(*I))
1392 } else if (IDC->Encloses(CurContext))
1396 IdResolver.InsertDeclAfter(I, D);
1398 IdResolver.AddDecl(D);
1402 void Sema::pushExternalDeclIntoScope(NamedDecl *D, DeclarationName Name) {
1403 if (IdResolver.tryAddTopLevelDecl(D, Name) && TUScope)
1404 TUScope->AddDecl(D);
1407 bool Sema::isDeclInScope(NamedDecl *D, DeclContext *Ctx, Scope *S,
1408 bool AllowInlineNamespace) {
1409 return IdResolver.isDeclInScope(D, Ctx, S, AllowInlineNamespace);
1412 Scope *Sema::getScopeForDeclContext(Scope *S, DeclContext *DC) {
1413 DeclContext *TargetDC = DC->getPrimaryContext();
1415 if (DeclContext *ScopeDC = S->getEntity())
1416 if (ScopeDC->getPrimaryContext() == TargetDC)
1418 } while ((S = S->getParent()));
1423 static bool isOutOfScopePreviousDeclaration(NamedDecl *,
1427 /// Filters out lookup results that don't fall within the given scope
1428 /// as determined by isDeclInScope.
1429 void Sema::FilterLookupForScope(LookupResult &R, DeclContext *Ctx, Scope *S,
1430 bool ConsiderLinkage,
1431 bool AllowInlineNamespace) {
1432 LookupResult::Filter F = R.makeFilter();
1433 while (F.hasNext()) {
1434 NamedDecl *D = F.next();
1436 if (isDeclInScope(D, Ctx, S, AllowInlineNamespace))
1439 if (ConsiderLinkage && isOutOfScopePreviousDeclaration(D, Ctx, Context))
1448 /// We've determined that \p New is a redeclaration of \p Old. Check that they
1449 /// have compatible owning modules.
1450 bool Sema::CheckRedeclarationModuleOwnership(NamedDecl *New, NamedDecl *Old) {
1451 // FIXME: The Modules TS is not clear about how friend declarations are
1452 // to be treated. It's not meaningful to have different owning modules for
1453 // linkage in redeclarations of the same entity, so for now allow the
1454 // redeclaration and change the owning modules to match.
1455 if (New->getFriendObjectKind() &&
1456 Old->getOwningModuleForLinkage() != New->getOwningModuleForLinkage()) {
1457 New->setLocalOwningModule(Old->getOwningModule());
1458 makeMergedDefinitionVisible(New);
1462 Module *NewM = New->getOwningModule();
1463 Module *OldM = Old->getOwningModule();
1467 // FIXME: Check proclaimed-ownership-declarations here too.
1468 bool NewIsModuleInterface = NewM && NewM->Kind == Module::ModuleInterfaceUnit;
1469 bool OldIsModuleInterface = OldM && OldM->Kind == Module::ModuleInterfaceUnit;
1470 if (NewIsModuleInterface || OldIsModuleInterface) {
1471 // C++ Modules TS [basic.def.odr] 6.2/6.7 [sic]:
1472 // if a declaration of D [...] appears in the purview of a module, all
1473 // other such declarations shall appear in the purview of the same module
1474 Diag(New->getLocation(), diag::err_mismatched_owning_module)
1476 << NewIsModuleInterface
1477 << (NewIsModuleInterface ? NewM->getFullModuleName() : "")
1478 << OldIsModuleInterface
1479 << (OldIsModuleInterface ? OldM->getFullModuleName() : "");
1480 Diag(Old->getLocation(), diag::note_previous_declaration);
1481 New->setInvalidDecl();
1488 static bool isUsingDecl(NamedDecl *D) {
1489 return isa<UsingShadowDecl>(D) ||
1490 isa<UnresolvedUsingTypenameDecl>(D) ||
1491 isa<UnresolvedUsingValueDecl>(D);
1494 /// Removes using shadow declarations from the lookup results.
1495 static void RemoveUsingDecls(LookupResult &R) {
1496 LookupResult::Filter F = R.makeFilter();
1498 if (isUsingDecl(F.next()))
1504 /// Check for this common pattern:
1507 /// S(const S&); // DO NOT IMPLEMENT
1508 /// void operator=(const S&); // DO NOT IMPLEMENT
1511 static bool IsDisallowedCopyOrAssign(const CXXMethodDecl *D) {
1512 // FIXME: Should check for private access too but access is set after we get
1514 if (D->doesThisDeclarationHaveABody())
1517 if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(D))
1518 return CD->isCopyConstructor();
1519 return D->isCopyAssignmentOperator();
1522 // We need this to handle
1525 // void *foo() { return 0; }
1528 // When we see foo we don't know if after the typedef we will get 'A' or '*A'
1529 // for example. If 'A', foo will have external linkage. If we have '*A',
1530 // foo will have no linkage. Since we can't know until we get to the end
1531 // of the typedef, this function finds out if D might have non-external linkage.
1532 // Callers should verify at the end of the TU if it D has external linkage or
1534 bool Sema::mightHaveNonExternalLinkage(const DeclaratorDecl *D) {
1535 const DeclContext *DC = D->getDeclContext();
1536 while (!DC->isTranslationUnit()) {
1537 if (const RecordDecl *RD = dyn_cast<RecordDecl>(DC)){
1538 if (!RD->hasNameForLinkage())
1541 DC = DC->getParent();
1544 return !D->isExternallyVisible();
1547 // FIXME: This needs to be refactored; some other isInMainFile users want
1549 static bool isMainFileLoc(const Sema &S, SourceLocation Loc) {
1550 if (S.TUKind != TU_Complete)
1552 return S.SourceMgr.isInMainFile(Loc);
1555 bool Sema::ShouldWarnIfUnusedFileScopedDecl(const DeclaratorDecl *D) const {
1558 if (D->isInvalidDecl() || D->isUsed() || D->hasAttr<UnusedAttr>())
1561 // Ignore all entities declared within templates, and out-of-line definitions
1562 // of members of class templates.
1563 if (D->getDeclContext()->isDependentContext() ||
1564 D->getLexicalDeclContext()->isDependentContext())
1567 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1568 if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1570 // A non-out-of-line declaration of a member specialization was implicitly
1571 // instantiated; it's the out-of-line declaration that we're interested in.
1572 if (FD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1573 FD->getMemberSpecializationInfo() && !FD->isOutOfLine())
1576 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
1577 if (MD->isVirtual() || IsDisallowedCopyOrAssign(MD))
1580 // 'static inline' functions are defined in headers; don't warn.
1581 if (FD->isInlined() && !isMainFileLoc(*this, FD->getLocation()))
1585 if (FD->doesThisDeclarationHaveABody() &&
1586 Context.DeclMustBeEmitted(FD))
1588 } else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1589 // Constants and utility variables are defined in headers with internal
1590 // linkage; don't warn. (Unlike functions, there isn't a convenient marker
1592 if (!isMainFileLoc(*this, VD->getLocation()))
1595 if (Context.DeclMustBeEmitted(VD))
1598 if (VD->isStaticDataMember() &&
1599 VD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
1601 if (VD->isStaticDataMember() &&
1602 VD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
1603 VD->getMemberSpecializationInfo() && !VD->isOutOfLine())
1606 if (VD->isInline() && !isMainFileLoc(*this, VD->getLocation()))
1612 // Only warn for unused decls internal to the translation unit.
1613 // FIXME: This seems like a bogus check; it suppresses -Wunused-function
1614 // for inline functions defined in the main source file, for instance.
1615 return mightHaveNonExternalLinkage(D);
1618 void Sema::MarkUnusedFileScopedDecl(const DeclaratorDecl *D) {
1622 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
1623 const FunctionDecl *First = FD->getFirstDecl();
1624 if (FD != First && ShouldWarnIfUnusedFileScopedDecl(First))
1625 return; // First should already be in the vector.
1628 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1629 const VarDecl *First = VD->getFirstDecl();
1630 if (VD != First && ShouldWarnIfUnusedFileScopedDecl(First))
1631 return; // First should already be in the vector.
1634 if (ShouldWarnIfUnusedFileScopedDecl(D))
1635 UnusedFileScopedDecls.push_back(D);
1638 static bool ShouldDiagnoseUnusedDecl(const NamedDecl *D) {
1639 if (D->isInvalidDecl())
1642 bool Referenced = false;
1643 if (auto *DD = dyn_cast<DecompositionDecl>(D)) {
1644 // For a decomposition declaration, warn if none of the bindings are
1645 // referenced, instead of if the variable itself is referenced (which
1646 // it is, by the bindings' expressions).
1647 for (auto *BD : DD->bindings()) {
1648 if (BD->isReferenced()) {
1653 } else if (!D->getDeclName()) {
1655 } else if (D->isReferenced() || D->isUsed()) {
1659 if (Referenced || D->hasAttr<UnusedAttr>() ||
1660 D->hasAttr<ObjCPreciseLifetimeAttr>())
1663 if (isa<LabelDecl>(D))
1666 // Except for labels, we only care about unused decls that are local to
1668 bool WithinFunction = D->getDeclContext()->isFunctionOrMethod();
1669 if (const auto *R = dyn_cast<CXXRecordDecl>(D->getDeclContext()))
1670 // For dependent types, the diagnostic is deferred.
1672 WithinFunction || (R->isLocalClass() && !R->isDependentType());
1673 if (!WithinFunction)
1676 if (isa<TypedefNameDecl>(D))
1679 // White-list anything that isn't a local variable.
1680 if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D) || isa<ImplicitParamDecl>(D))
1683 // Types of valid local variables should be complete, so this should succeed.
1684 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1686 // White-list anything with an __attribute__((unused)) type.
1687 const auto *Ty = VD->getType().getTypePtr();
1689 // Only look at the outermost level of typedef.
1690 if (const TypedefType *TT = Ty->getAs<TypedefType>()) {
1691 if (TT->getDecl()->hasAttr<UnusedAttr>())
1695 // If we failed to complete the type for some reason, or if the type is
1696 // dependent, don't diagnose the variable.
1697 if (Ty->isIncompleteType() || Ty->isDependentType())
1700 // Look at the element type to ensure that the warning behaviour is
1701 // consistent for both scalars and arrays.
1702 Ty = Ty->getBaseElementTypeUnsafe();
1704 if (const TagType *TT = Ty->getAs<TagType>()) {
1705 const TagDecl *Tag = TT->getDecl();
1706 if (Tag->hasAttr<UnusedAttr>())
1709 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Tag)) {
1710 if (!RD->hasTrivialDestructor() && !RD->hasAttr<WarnUnusedAttr>())
1713 if (const Expr *Init = VD->getInit()) {
1714 if (const ExprWithCleanups *Cleanups =
1715 dyn_cast<ExprWithCleanups>(Init))
1716 Init = Cleanups->getSubExpr();
1717 const CXXConstructExpr *Construct =
1718 dyn_cast<CXXConstructExpr>(Init);
1719 if (Construct && !Construct->isElidable()) {
1720 CXXConstructorDecl *CD = Construct->getConstructor();
1721 if (!CD->isTrivial() && !RD->hasAttr<WarnUnusedAttr>() &&
1722 (VD->getInit()->isValueDependent() || !VD->evaluateValue()))
1729 // TODO: __attribute__((unused)) templates?
1735 static void GenerateFixForUnusedDecl(const NamedDecl *D, ASTContext &Ctx,
1737 if (isa<LabelDecl>(D)) {
1738 SourceLocation AfterColon = Lexer::findLocationAfterToken(
1739 D->getEndLoc(), tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(),
1741 if (AfterColon.isInvalid())
1743 Hint = FixItHint::CreateRemoval(
1744 CharSourceRange::getCharRange(D->getBeginLoc(), AfterColon));
1748 void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
1749 if (D->getTypeForDecl()->isDependentType())
1752 for (auto *TmpD : D->decls()) {
1753 if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
1754 DiagnoseUnusedDecl(T);
1755 else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
1756 DiagnoseUnusedNestedTypedefs(R);
1760 /// DiagnoseUnusedDecl - Emit warnings about declarations that are not used
1761 /// unless they are marked attr(unused).
1762 void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
1763 if (!ShouldDiagnoseUnusedDecl(D))
1766 if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
1767 // typedefs can be referenced later on, so the diagnostics are emitted
1768 // at end-of-translation-unit.
1769 UnusedLocalTypedefNameCandidates.insert(TD);
1774 GenerateFixForUnusedDecl(D, Context, Hint);
1777 if (isa<VarDecl>(D) && cast<VarDecl>(D)->isExceptionVariable())
1778 DiagID = diag::warn_unused_exception_param;
1779 else if (isa<LabelDecl>(D))
1780 DiagID = diag::warn_unused_label;
1782 DiagID = diag::warn_unused_variable;
1784 Diag(D->getLocation(), DiagID) << D << Hint;
1787 static void CheckPoppedLabel(LabelDecl *L, Sema &S) {
1788 // Verify that we have no forward references left. If so, there was a goto
1789 // or address of a label taken, but no definition of it. Label fwd
1790 // definitions are indicated with a null substmt which is also not a resolved
1791 // MS inline assembly label name.
1792 bool Diagnose = false;
1793 if (L->isMSAsmLabel())
1794 Diagnose = !L->isResolvedMSAsmLabel();
1796 Diagnose = L->getStmt() == nullptr;
1798 S.Diag(L->getLocation(), diag::err_undeclared_label_use) <<L->getDeclName();
1801 void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
1802 S->mergeNRVOIntoParent();
1804 if (S->decl_empty()) return;
1805 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
1806 "Scope shouldn't contain decls!");
1808 for (auto *TmpD : S->decls()) {
1809 assert(TmpD && "This decl didn't get pushed??");
1811 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?");
1812 NamedDecl *D = cast<NamedDecl>(TmpD);
1814 // Diagnose unused variables in this scope.
1815 if (!S->hasUnrecoverableErrorOccurred()) {
1816 DiagnoseUnusedDecl(D);
1817 if (const auto *RD = dyn_cast<RecordDecl>(D))
1818 DiagnoseUnusedNestedTypedefs(RD);
1821 if (!D->getDeclName()) continue;
1823 // If this was a forward reference to a label, verify it was defined.
1824 if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
1825 CheckPoppedLabel(LD, *this);
1827 // Remove this name from our lexical scope, and warn on it if we haven't
1829 IdResolver.RemoveDecl(D);
1830 auto ShadowI = ShadowingDecls.find(D);
1831 if (ShadowI != ShadowingDecls.end()) {
1832 if (const auto *FD = dyn_cast<FieldDecl>(ShadowI->second)) {
1833 Diag(D->getLocation(), diag::warn_ctor_parm_shadows_field)
1834 << D << FD << FD->getParent();
1835 Diag(FD->getLocation(), diag::note_previous_declaration);
1837 ShadowingDecls.erase(ShadowI);
1842 /// Look for an Objective-C class in the translation unit.
1844 /// \param Id The name of the Objective-C class we're looking for. If
1845 /// typo-correction fixes this name, the Id will be updated
1846 /// to the fixed name.
1848 /// \param IdLoc The location of the name in the translation unit.
1850 /// \param DoTypoCorrection If true, this routine will attempt typo correction
1851 /// if there is no class with the given name.
1853 /// \returns The declaration of the named Objective-C class, or NULL if the
1854 /// class could not be found.
1855 ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id,
1856 SourceLocation IdLoc,
1857 bool DoTypoCorrection) {
1858 // The third "scope" argument is 0 since we aren't enabling lazy built-in
1859 // creation from this context.
1860 NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName);
1862 if (!IDecl && DoTypoCorrection) {
1863 // Perform typo correction at the given location, but only if we
1864 // find an Objective-C class name.
1865 if (TypoCorrection C = CorrectTypo(
1866 DeclarationNameInfo(Id, IdLoc), LookupOrdinaryName, TUScope, nullptr,
1867 llvm::make_unique<DeclFilterCCC<ObjCInterfaceDecl>>(),
1868 CTK_ErrorRecovery)) {
1869 diagnoseTypo(C, PDiag(diag::err_undef_interface_suggest) << Id);
1870 IDecl = C.getCorrectionDeclAs<ObjCInterfaceDecl>();
1871 Id = IDecl->getIdentifier();
1874 ObjCInterfaceDecl *Def = dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
1875 // This routine must always return a class definition, if any.
1876 if (Def && Def->getDefinition())
1877 Def = Def->getDefinition();
1881 /// getNonFieldDeclScope - Retrieves the innermost scope, starting
1882 /// from S, where a non-field would be declared. This routine copes
1883 /// with the difference between C and C++ scoping rules in structs and
1884 /// unions. For example, the following code is well-formed in C but
1885 /// ill-formed in C++:
1891 /// void test_S6() {
1896 /// For the declaration of BAR, this routine will return a different
1897 /// scope. The scope S will be the scope of the unnamed enumeration
1898 /// within S6. In C++, this routine will return the scope associated
1899 /// with S6, because the enumeration's scope is a transparent
1900 /// context but structures can contain non-field names. In C, this
1901 /// routine will return the translation unit scope, since the
1902 /// enumeration's scope is a transparent context and structures cannot
1903 /// contain non-field names.
1904 Scope *Sema::getNonFieldDeclScope(Scope *S) {
1905 while (((S->getFlags() & Scope::DeclScope) == 0) ||
1906 (S->getEntity() && S->getEntity()->isTransparentContext()) ||
1907 (S->isClassScope() && !getLangOpts().CPlusPlus))
1912 /// Looks up the declaration of "struct objc_super" and
1913 /// saves it for later use in building builtin declaration of
1914 /// objc_msgSendSuper and objc_msgSendSuper_stret. If no such
1915 /// pre-existing declaration exists no action takes place.
1916 static void LookupPredefedObjCSuperType(Sema &ThisSema, Scope *S,
1917 IdentifierInfo *II) {
1918 if (!II->isStr("objc_msgSendSuper"))
1920 ASTContext &Context = ThisSema.Context;
1922 LookupResult Result(ThisSema, &Context.Idents.get("objc_super"),
1923 SourceLocation(), Sema::LookupTagName);
1924 ThisSema.LookupName(Result, S);
1925 if (Result.getResultKind() == LookupResult::Found)
1926 if (const TagDecl *TD = Result.getAsSingle<TagDecl>())
1927 Context.setObjCSuperType(Context.getTagDeclType(TD));
1930 static StringRef getHeaderName(ASTContext::GetBuiltinTypeError Error) {
1932 case ASTContext::GE_None:
1934 case ASTContext::GE_Missing_stdio:
1936 case ASTContext::GE_Missing_setjmp:
1938 case ASTContext::GE_Missing_ucontext:
1939 return "ucontext.h";
1941 llvm_unreachable("unhandled error kind");
1944 /// LazilyCreateBuiltin - The specified Builtin-ID was first used at
1945 /// file scope. lazily create a decl for it. ForRedeclaration is true
1946 /// if we're creating this built-in in anticipation of redeclaring the
1948 NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
1949 Scope *S, bool ForRedeclaration,
1950 SourceLocation Loc) {
1951 LookupPredefedObjCSuperType(*this, S, II);
1953 ASTContext::GetBuiltinTypeError Error;
1954 QualType R = Context.GetBuiltinType(ID, Error);
1956 if (ForRedeclaration)
1957 Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
1958 << getHeaderName(Error) << Context.BuiltinInfo.getName(ID);
1962 if (!ForRedeclaration &&
1963 (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
1964 Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
1965 Diag(Loc, diag::ext_implicit_lib_function_decl)
1966 << Context.BuiltinInfo.getName(ID) << R;
1967 if (Context.BuiltinInfo.getHeaderName(ID) &&
1968 !Diags.isIgnored(diag::ext_implicit_lib_function_decl, Loc))
1969 Diag(Loc, diag::note_include_header_or_declare)
1970 << Context.BuiltinInfo.getHeaderName(ID)
1971 << Context.BuiltinInfo.getName(ID);
1977 DeclContext *Parent = Context.getTranslationUnitDecl();
1978 if (getLangOpts().CPlusPlus) {
1979 LinkageSpecDecl *CLinkageDecl =
1980 LinkageSpecDecl::Create(Context, Parent, Loc, Loc,
1981 LinkageSpecDecl::lang_c, false);
1982 CLinkageDecl->setImplicit();
1983 Parent->addDecl(CLinkageDecl);
1984 Parent = CLinkageDecl;
1987 FunctionDecl *New = FunctionDecl::Create(Context,
1989 Loc, Loc, II, R, /*TInfo=*/nullptr,
1992 R->isFunctionProtoType());
1995 // Create Decl objects for each parameter, adding them to the
1997 if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) {
1998 SmallVector<ParmVarDecl*, 16> Params;
1999 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
2001 ParmVarDecl::Create(Context, New, SourceLocation(), SourceLocation(),
2002 nullptr, FT->getParamType(i), /*TInfo=*/nullptr,
2004 parm->setScopeInfo(0, i);
2005 Params.push_back(parm);
2007 New->setParams(Params);
2010 AddKnownFunctionAttributes(New);
2011 RegisterLocallyScopedExternCDecl(New, S);
2013 // TUScope is the translation-unit scope to insert this function into.
2014 // FIXME: This is hideous. We need to teach PushOnScopeChains to
2015 // relate Scopes to DeclContexts, and probably eliminate CurContext
2016 // entirely, but we're not there yet.
2017 DeclContext *SavedContext = CurContext;
2018 CurContext = Parent;
2019 PushOnScopeChains(New, TUScope);
2020 CurContext = SavedContext;
2024 /// Typedef declarations don't have linkage, but they still denote the same
2025 /// entity if their types are the same.
2026 /// FIXME: This is notionally doing the same thing as ASTReaderDecl's
2028 static void filterNonConflictingPreviousTypedefDecls(Sema &S,
2029 TypedefNameDecl *Decl,
2030 LookupResult &Previous) {
2031 // This is only interesting when modules are enabled.
2032 if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
2035 // Empty sets are uninteresting.
2036 if (Previous.empty())
2039 LookupResult::Filter Filter = Previous.makeFilter();
2040 while (Filter.hasNext()) {
2041 NamedDecl *Old = Filter.next();
2043 // Non-hidden declarations are never ignored.
2044 if (S.isVisible(Old))
2047 // Declarations of the same entity are not ignored, even if they have
2048 // different linkages.
2049 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2050 if (S.Context.hasSameType(OldTD->getUnderlyingType(),
2051 Decl->getUnderlyingType()))
2054 // If both declarations give a tag declaration a typedef name for linkage
2055 // purposes, then they declare the same entity.
2056 if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
2057 Decl->getAnonDeclWithTypedefName())
2067 bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
2069 if (TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Old))
2070 OldType = OldTypedef->getUnderlyingType();
2072 OldType = Context.getTypeDeclType(Old);
2073 QualType NewType = New->getUnderlyingType();
2075 if (NewType->isVariablyModifiedType()) {
2076 // Must not redefine a typedef with a variably-modified type.
2077 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2078 Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
2080 if (Old->getLocation().isValid())
2081 notePreviousDefinition(Old, New->getLocation());
2082 New->setInvalidDecl();
2086 if (OldType != NewType &&
2087 !OldType->isDependentType() &&
2088 !NewType->isDependentType() &&
2089 !Context.hasSameType(OldType, NewType)) {
2090 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2091 Diag(New->getLocation(), diag::err_redefinition_different_typedef)
2092 << Kind << NewType << OldType;
2093 if (Old->getLocation().isValid())
2094 notePreviousDefinition(Old, New->getLocation());
2095 New->setInvalidDecl();
2101 /// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the
2102 /// same name and scope as a previous declaration 'Old'. Figure out
2103 /// how to resolve this situation, merging decls or emitting
2104 /// diagnostics as appropriate. If there was an error, set New to be invalid.
2106 void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
2107 LookupResult &OldDecls) {
2108 // If the new decl is known invalid already, don't bother doing any
2110 if (New->isInvalidDecl()) return;
2112 // Allow multiple definitions for ObjC built-in typedefs.
2113 // FIXME: Verify the underlying types are equivalent!
2114 if (getLangOpts().ObjC) {
2115 const IdentifierInfo *TypeID = New->getIdentifier();
2116 switch (TypeID->getLength()) {
2120 if (!TypeID->isStr("id"))
2122 QualType T = New->getUnderlyingType();
2123 if (!T->isPointerType())
2125 if (!T->isVoidPointerType()) {
2126 QualType PT = T->getAs<PointerType>()->getPointeeType();
2127 if (!PT->isStructureType())
2130 Context.setObjCIdRedefinitionType(T);
2131 // Install the built-in type for 'id', ignoring the current definition.
2132 New->setTypeForDecl(Context.getObjCIdType().getTypePtr());
2136 if (!TypeID->isStr("Class"))
2138 Context.setObjCClassRedefinitionType(New->getUnderlyingType());
2139 // Install the built-in type for 'Class', ignoring the current definition.
2140 New->setTypeForDecl(Context.getObjCClassType().getTypePtr());
2143 if (!TypeID->isStr("SEL"))
2145 Context.setObjCSelRedefinitionType(New->getUnderlyingType());
2146 // Install the built-in type for 'SEL', ignoring the current definition.
2147 New->setTypeForDecl(Context.getObjCSelType().getTypePtr());
2150 // Fall through - the typedef name was not a builtin type.
2153 // Verify the old decl was also a type.
2154 TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
2156 Diag(New->getLocation(), diag::err_redefinition_different_kind)
2157 << New->getDeclName();
2159 NamedDecl *OldD = OldDecls.getRepresentativeDecl();
2160 if (OldD->getLocation().isValid())
2161 notePreviousDefinition(OldD, New->getLocation());
2163 return New->setInvalidDecl();
2166 // If the old declaration is invalid, just give up here.
2167 if (Old->isInvalidDecl())
2168 return New->setInvalidDecl();
2170 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2171 auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
2172 auto *NewTag = New->getAnonDeclWithTypedefName();
2173 NamedDecl *Hidden = nullptr;
2174 if (OldTag && NewTag &&
2175 OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
2176 !hasVisibleDefinition(OldTag, &Hidden)) {
2177 // There is a definition of this tag, but it is not visible. Use it
2178 // instead of our tag.
2179 New->setTypeForDecl(OldTD->getTypeForDecl());
2180 if (OldTD->isModed())
2181 New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(),
2182 OldTD->getUnderlyingType());
2184 New->setTypeSourceInfo(OldTD->getTypeSourceInfo());
2186 // Make the old tag definition visible.
2187 makeMergedDefinitionVisible(Hidden);
2189 // If this was an unscoped enumeration, yank all of its enumerators
2190 // out of the scope.
2191 if (isa<EnumDecl>(NewTag)) {
2192 Scope *EnumScope = getNonFieldDeclScope(S);
2193 for (auto *D : NewTag->decls()) {
2194 auto *ED = cast<EnumConstantDecl>(D);
2195 assert(EnumScope->isDeclScope(ED));
2196 EnumScope->RemoveDecl(ED);
2197 IdResolver.RemoveDecl(ED);
2198 ED->getLexicalDeclContext()->removeDecl(ED);
2204 // If the typedef types are not identical, reject them in all languages and
2205 // with any extensions enabled.
2206 if (isIncompatibleTypedef(Old, New))
2209 // The types match. Link up the redeclaration chain and merge attributes if
2210 // the old declaration was a typedef.
2211 if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old)) {
2212 New->setPreviousDecl(Typedef);
2213 mergeDeclAttributes(New, Old);
2216 if (getLangOpts().MicrosoftExt)
2219 if (getLangOpts().CPlusPlus) {
2220 // C++ [dcl.typedef]p2:
2221 // In a given non-class scope, a typedef specifier can be used to
2222 // redefine the name of any type declared in that scope to refer
2223 // to the type to which it already refers.
2224 if (!isa<CXXRecordDecl>(CurContext))
2227 // C++0x [dcl.typedef]p4:
2228 // In a given class scope, a typedef specifier can be used to redefine
2229 // any class-name declared in that scope that is not also a typedef-name
2230 // to refer to the type to which it already refers.
2232 // This wording came in via DR424, which was a correction to the
2233 // wording in DR56, which accidentally banned code like:
2236 // typedef struct A { } A;
2239 // in the C++03 standard. We implement the C++0x semantics, which
2240 // allow the above but disallow
2247 // since that was the intent of DR56.
2248 if (!isa<TypedefNameDecl>(Old))
2251 Diag(New->getLocation(), diag::err_redefinition)
2252 << New->getDeclName();
2253 notePreviousDefinition(Old, New->getLocation());
2254 return New->setInvalidDecl();
2257 // Modules always permit redefinition of typedefs, as does C11.
2258 if (getLangOpts().Modules || getLangOpts().C11)
2261 // If we have a redefinition of a typedef in C, emit a warning. This warning
2262 // is normally mapped to an error, but can be controlled with
2263 // -Wtypedef-redefinition. If either the original or the redefinition is
2264 // in a system header, don't emit this for compatibility with GCC.
2265 if (getDiagnostics().getSuppressSystemWarnings() &&
2266 // Some standard types are defined implicitly in Clang (e.g. OpenCL).
2267 (Old->isImplicit() ||
2268 Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
2269 Context.getSourceManager().isInSystemHeader(New->getLocation())))
2272 Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
2273 << New->getDeclName();
2274 notePreviousDefinition(Old, New->getLocation());
2277 /// DeclhasAttr - returns true if decl Declaration already has the target
2279 static bool DeclHasAttr(const Decl *D, const Attr *A) {
2280 const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
2281 const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
2282 for (const auto *i : D->attrs())
2283 if (i->getKind() == A->getKind()) {
2285 if (Ann->getAnnotation() == cast<AnnotateAttr>(i)->getAnnotation())
2289 // FIXME: Don't hardcode this check
2290 if (OA && isa<OwnershipAttr>(i))
2291 return OA->getOwnKind() == cast<OwnershipAttr>(i)->getOwnKind();
2298 static bool isAttributeTargetADefinition(Decl *D) {
2299 if (VarDecl *VD = dyn_cast<VarDecl>(D))
2300 return VD->isThisDeclarationADefinition();
2301 if (TagDecl *TD = dyn_cast<TagDecl>(D))
2302 return TD->isCompleteDefinition() || TD->isBeingDefined();
2306 /// Merge alignment attributes from \p Old to \p New, taking into account the
2307 /// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
2309 /// \return \c true if any attributes were added to \p New.
2310 static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
2311 // Look for alignas attributes on Old, and pick out whichever attribute
2312 // specifies the strictest alignment requirement.
2313 AlignedAttr *OldAlignasAttr = nullptr;
2314 AlignedAttr *OldStrictestAlignAttr = nullptr;
2315 unsigned OldAlign = 0;
2316 for (auto *I : Old->specific_attrs<AlignedAttr>()) {
2317 // FIXME: We have no way of representing inherited dependent alignments
2319 // template<int A, int B> struct alignas(A) X;
2320 // template<int A, int B> struct alignas(B) X {};
2321 // For now, we just ignore any alignas attributes which are not on the
2322 // definition in such a case.
2323 if (I->isAlignmentDependent())
2329 unsigned Align = I->getAlignment(S.Context);
2330 if (Align > OldAlign) {
2332 OldStrictestAlignAttr = I;
2336 // Look for alignas attributes on New.
2337 AlignedAttr *NewAlignasAttr = nullptr;
2338 unsigned NewAlign = 0;
2339 for (auto *I : New->specific_attrs<AlignedAttr>()) {
2340 if (I->isAlignmentDependent())
2346 unsigned Align = I->getAlignment(S.Context);
2347 if (Align > NewAlign)
2351 if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
2352 // Both declarations have 'alignas' attributes. We require them to match.
2353 // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
2354 // fall short. (If two declarations both have alignas, they must both match
2355 // every definition, and so must match each other if there is a definition.)
2357 // If either declaration only contains 'alignas(0)' specifiers, then it
2358 // specifies the natural alignment for the type.
2359 if (OldAlign == 0 || NewAlign == 0) {
2361 if (ValueDecl *VD = dyn_cast<ValueDecl>(New))
2364 Ty = S.Context.getTagDeclType(cast<TagDecl>(New));
2367 OldAlign = S.Context.getTypeAlign(Ty);
2369 NewAlign = S.Context.getTypeAlign(Ty);
2372 if (OldAlign != NewAlign) {
2373 S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch)
2374 << (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity()
2375 << (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity();
2376 S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration);
2380 if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) {
2381 // C++11 [dcl.align]p6:
2382 // if any declaration of an entity has an alignment-specifier,
2383 // every defining declaration of that entity shall specify an
2384 // equivalent alignment.
2386 // If the definition of an object does not have an alignment
2387 // specifier, any other declaration of that object shall also
2388 // have no alignment specifier.
2389 S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition)
2391 S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration)
2395 bool AnyAdded = false;
2397 // Ensure we have an attribute representing the strictest alignment.
2398 if (OldAlign > NewAlign) {
2399 AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context);
2400 Clone->setInherited(true);
2401 New->addAttr(Clone);
2405 // Ensure we have an alignas attribute if the old declaration had one.
2406 if (OldAlignasAttr && !NewAlignasAttr &&
2407 !(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
2408 AlignedAttr *Clone = OldAlignasAttr->clone(S.Context);
2409 Clone->setInherited(true);
2410 New->addAttr(Clone);
2417 static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
2418 const InheritableAttr *Attr,
2419 Sema::AvailabilityMergeKind AMK) {
2420 // This function copies an attribute Attr from a previous declaration to the
2421 // new declaration D if the new declaration doesn't itself have that attribute
2422 // yet or if that attribute allows duplicates.
2423 // If you're adding a new attribute that requires logic different from
2424 // "use explicit attribute on decl if present, else use attribute from
2425 // previous decl", for example if the attribute needs to be consistent
2426 // between redeclarations, you need to call a custom merge function here.
2427 InheritableAttr *NewAttr = nullptr;
2428 unsigned AttrSpellingListIndex = Attr->getSpellingListIndex();
2429 if (const auto *AA = dyn_cast<AvailabilityAttr>(Attr))
2430 NewAttr = S.mergeAvailabilityAttr(D, AA->getRange(), AA->getPlatform(),
2431 AA->isImplicit(), AA->getIntroduced(),
2432 AA->getDeprecated(),
2433 AA->getObsoleted(), AA->getUnavailable(),
2434 AA->getMessage(), AA->getStrict(),
2435 AA->getReplacement(), AMK,
2436 AttrSpellingListIndex);
2437 else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
2438 NewAttr = S.mergeVisibilityAttr(D, VA->getRange(), VA->getVisibility(),
2439 AttrSpellingListIndex);
2440 else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
2441 NewAttr = S.mergeTypeVisibilityAttr(D, VA->getRange(), VA->getVisibility(),
2442 AttrSpellingListIndex);
2443 else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Attr))
2444 NewAttr = S.mergeDLLImportAttr(D, ImportA->getRange(),
2445 AttrSpellingListIndex);
2446 else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Attr))
2447 NewAttr = S.mergeDLLExportAttr(D, ExportA->getRange(),
2448 AttrSpellingListIndex);
2449 else if (const auto *FA = dyn_cast<FormatAttr>(Attr))
2450 NewAttr = S.mergeFormatAttr(D, FA->getRange(), FA->getType(),
2451 FA->getFormatIdx(), FA->getFirstArg(),
2452 AttrSpellingListIndex);
2453 else if (const auto *SA = dyn_cast<SectionAttr>(Attr))
2454 NewAttr = S.mergeSectionAttr(D, SA->getRange(), SA->getName(),
2455 AttrSpellingListIndex);
2456 else if (const auto *CSA = dyn_cast<CodeSegAttr>(Attr))
2457 NewAttr = S.mergeCodeSegAttr(D, CSA->getRange(), CSA->getName(),
2458 AttrSpellingListIndex);
2459 else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Attr))
2460 NewAttr = S.mergeMSInheritanceAttr(D, IA->getRange(), IA->getBestCase(),
2461 AttrSpellingListIndex,
2462 IA->getSemanticSpelling());
2463 else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Attr))
2464 NewAttr = S.mergeAlwaysInlineAttr(D, AA->getRange(),
2465 &S.Context.Idents.get(AA->getSpelling()),
2466 AttrSpellingListIndex);
2467 else if (S.getLangOpts().CUDA && isa<FunctionDecl>(D) &&
2468 (isa<CUDAHostAttr>(Attr) || isa<CUDADeviceAttr>(Attr) ||
2469 isa<CUDAGlobalAttr>(Attr))) {
2470 // CUDA target attributes are part of function signature for
2471 // overloading purposes and must not be merged.
2473 } else if (const auto *MA = dyn_cast<MinSizeAttr>(Attr))
2474 NewAttr = S.mergeMinSizeAttr(D, MA->getRange(), AttrSpellingListIndex);
2475 else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Attr))
2476 NewAttr = S.mergeOptimizeNoneAttr(D, OA->getRange(), AttrSpellingListIndex);
2477 else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Attr))
2478 NewAttr = S.mergeInternalLinkageAttr(D, *InternalLinkageA);
2479 else if (const auto *CommonA = dyn_cast<CommonAttr>(Attr))
2480 NewAttr = S.mergeCommonAttr(D, *CommonA);
2481 else if (isa<AlignedAttr>(Attr))
2482 // AlignedAttrs are handled separately, because we need to handle all
2483 // such attributes on a declaration at the same time.
2485 else if ((isa<DeprecatedAttr>(Attr) || isa<UnavailableAttr>(Attr)) &&
2486 (AMK == Sema::AMK_Override ||
2487 AMK == Sema::AMK_ProtocolImplementation))
2489 else if (const auto *UA = dyn_cast<UuidAttr>(Attr))
2490 NewAttr = S.mergeUuidAttr(D, UA->getRange(), AttrSpellingListIndex,
2492 else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr))
2493 NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));
2496 NewAttr->setInherited(true);
2497 D->addAttr(NewAttr);
2498 if (isa<MSInheritanceAttr>(NewAttr))
2499 S.Consumer.AssignInheritanceModel(cast<CXXRecordDecl>(D));
2506 static const NamedDecl *getDefinition(const Decl *D) {
2507 if (const TagDecl *TD = dyn_cast<TagDecl>(D))
2508 return TD->getDefinition();
2509 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
2510 const VarDecl *Def = VD->getDefinition();
2513 return VD->getActingDefinition();
2515 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
2516 return FD->getDefinition();
2520 static bool hasAttribute(const Decl *D, attr::Kind Kind) {
2521 for (const auto *Attribute : D->attrs())
2522 if (Attribute->getKind() == Kind)
2527 /// checkNewAttributesAfterDef - If we already have a definition, check that
2528 /// there are no new attributes in this declaration.
2529 static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
2530 if (!New->hasAttrs())
2533 const NamedDecl *Def = getDefinition(Old);
2534 if (!Def || Def == New)
2537 AttrVec &NewAttributes = New->getAttrs();
2538 for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
2539 const Attr *NewAttribute = NewAttributes[I];
2541 if (isa<AliasAttr>(NewAttribute) || isa<IFuncAttr>(NewAttribute)) {
2542 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New)) {
2543 Sema::SkipBodyInfo SkipBody;
2544 S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def), &SkipBody);
2546 // If we're skipping this definition, drop the "alias" attribute.
2547 if (SkipBody.ShouldSkip) {
2548 NewAttributes.erase(NewAttributes.begin() + I);
2553 VarDecl *VD = cast<VarDecl>(New);
2554 unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
2555 VarDecl::TentativeDefinition
2556 ? diag::err_alias_after_tentative
2557 : diag::err_redefinition;
2558 S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
2559 if (Diag == diag::err_redefinition)
2560 S.notePreviousDefinition(Def, VD->getLocation());
2562 S.Diag(Def->getLocation(), diag::note_previous_definition);
2563 VD->setInvalidDecl();
2569 if (const VarDecl *VD = dyn_cast<VarDecl>(Def)) {
2570 // Tentative definitions are only interesting for the alias check above.
2571 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
2577 if (hasAttribute(Def, NewAttribute->getKind())) {
2579 continue; // regular attr merging will take care of validating this.
2582 if (isa<C11NoReturnAttr>(NewAttribute)) {
2583 // C's _Noreturn is allowed to be added to a function after it is defined.
2586 } else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(NewAttribute)) {
2587 if (AA->isAlignas()) {
2588 // C++11 [dcl.align]p6:
2589 // if any declaration of an entity has an alignment-specifier,
2590 // every defining declaration of that entity shall specify an
2591 // equivalent alignment.
2593 // If the definition of an object does not have an alignment
2594 // specifier, any other declaration of that object shall also
2595 // have no alignment specifier.
2596 S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition)
2598 S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration)
2600 NewAttributes.erase(NewAttributes.begin() + I);
2606 S.Diag(NewAttribute->getLocation(),
2607 diag::warn_attribute_precede_definition);
2608 S.Diag(Def->getLocation(), diag::note_previous_definition);
2609 NewAttributes.erase(NewAttributes.begin() + I);
2614 /// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
2615 void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
2616 AvailabilityMergeKind AMK) {
2617 if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
2618 UsedAttr *NewAttr = OldAttr->clone(Context);
2619 NewAttr->setInherited(true);
2620 New->addAttr(NewAttr);
2623 if (!Old->hasAttrs() && !New->hasAttrs())
2626 // Attributes declared post-definition are currently ignored.
2627 checkNewAttributesAfterDef(*this, New, Old);
2629 if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
2630 if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
2631 if (OldA->getLabel() != NewA->getLabel()) {
2632 // This redeclaration changes __asm__ label.
2633 Diag(New->getLocation(), diag::err_different_asm_label);
2634 Diag(OldA->getLocation(), diag::note_previous_declaration);
2636 } else if (Old->isUsed()) {
2637 // This redeclaration adds an __asm__ label to a declaration that has
2638 // already been ODR-used.
2639 Diag(New->getLocation(), diag::err_late_asm_label_name)
2640 << isa<FunctionDecl>(Old) << New->getAttr<AsmLabelAttr>()->getRange();
2644 // Re-declaration cannot add abi_tag's.
2645 if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
2646 if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
2647 for (const auto &NewTag : NewAbiTagAttr->tags()) {
2648 if (std::find(OldAbiTagAttr->tags_begin(), OldAbiTagAttr->tags_end(),
2649 NewTag) == OldAbiTagAttr->tags_end()) {
2650 Diag(NewAbiTagAttr->getLocation(),
2651 diag::err_new_abi_tag_on_redeclaration)
2653 Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration);
2657 Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration);
2658 Diag(Old->getLocation(), diag::note_previous_declaration);
2662 // This redeclaration adds a section attribute.
2663 if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
2664 if (auto *VD = dyn_cast<VarDecl>(New)) {
2665 if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
2666 Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
2667 Diag(Old->getLocation(), diag::note_previous_declaration);
2672 // Redeclaration adds code-seg attribute.
2673 const auto *NewCSA = New->getAttr<CodeSegAttr>();
2674 if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
2675 !NewCSA->isImplicit() && isa<CXXMethodDecl>(New)) {
2676 Diag(New->getLocation(), diag::warn_mismatched_section)
2678 Diag(Old->getLocation(), diag::note_previous_declaration);
2681 if (!Old->hasAttrs())
2684 bool foundAny = New->hasAttrs();
2686 // Ensure that any moving of objects within the allocated map is done before
2688 if (!foundAny) New->setAttrs(AttrVec());
2690 for (auto *I : Old->specific_attrs<InheritableAttr>()) {
2691 // Ignore deprecated/unavailable/availability attributes if requested.
2692 AvailabilityMergeKind LocalAMK = AMK_None;
2693 if (isa<DeprecatedAttr>(I) ||
2694 isa<UnavailableAttr>(I) ||
2695 isa<AvailabilityAttr>(I)) {
2700 case AMK_Redeclaration:
2702 case AMK_ProtocolImplementation:
2709 if (isa<UsedAttr>(I))
2712 if (mergeDeclAttribute(*this, New, I, LocalAMK))
2716 if (mergeAlignedAttrs(*this, New, Old))
2719 if (!foundAny) New->dropAttrs();
2722 /// mergeParamDeclAttributes - Copy attributes from the old parameter
2724 static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
2725 const ParmVarDecl *oldDecl,
2727 // C++11 [dcl.attr.depend]p2:
2728 // The first declaration of a function shall specify the
2729 // carries_dependency attribute for its declarator-id if any declaration
2730 // of the function specifies the carries_dependency attribute.
2731 const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
2732 if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
2733 S.Diag(CDA->getLocation(),
2734 diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
2735 // Find the first declaration of the parameter.
2736 // FIXME: Should we build redeclaration chains for function parameters?
2737 const FunctionDecl *FirstFD =
2738 cast<FunctionDecl>(oldDecl->getDeclContext())->getFirstDecl();
2739 const ParmVarDecl *FirstVD =
2740 FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex());
2741 S.Diag(FirstVD->getLocation(),
2742 diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
2745 if (!oldDecl->hasAttrs())
2748 bool foundAny = newDecl->hasAttrs();
2750 // Ensure that any moving of objects within the allocated map is
2751 // done before we process them.
2752 if (!foundAny) newDecl->setAttrs(AttrVec());
2754 for (const auto *I : oldDecl->specific_attrs<InheritableParamAttr>()) {
2755 if (!DeclHasAttr(newDecl, I)) {
2756 InheritableAttr *newAttr =
2757 cast<InheritableParamAttr>(I->clone(S.Context));
2758 newAttr->setInherited(true);
2759 newDecl->addAttr(newAttr);
2764 if (!foundAny) newDecl->dropAttrs();
2767 static void mergeParamDeclTypes(ParmVarDecl *NewParam,
2768 const ParmVarDecl *OldParam,
2770 if (auto Oldnullability = OldParam->getType()->getNullability(S.Context)) {
2771 if (auto Newnullability = NewParam->getType()->getNullability(S.Context)) {
2772 if (*Oldnullability != *Newnullability) {
2773 S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr)
2774 << DiagNullabilityKind(
2776 ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
2778 << DiagNullabilityKind(
2780 ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
2782 S.Diag(OldParam->getLocation(), diag::note_previous_declaration);
2785 QualType NewT = NewParam->getType();
2786 NewT = S.Context.getAttributedType(
2787 AttributedType::getNullabilityAttrKind(*Oldnullability),
2789 NewParam->setType(NewT);
2796 /// Used in MergeFunctionDecl to keep track of function parameters in
2798 struct GNUCompatibleParamWarning {
2799 ParmVarDecl *OldParm;
2800 ParmVarDecl *NewParm;
2801 QualType PromotedType;
2804 } // end anonymous namespace
2806 /// getSpecialMember - get the special member enum for a method.
2807 Sema::CXXSpecialMember Sema::getSpecialMember(const CXXMethodDecl *MD) {
2808 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
2809 if (Ctor->isDefaultConstructor())
2810 return Sema::CXXDefaultConstructor;
2812 if (Ctor->isCopyConstructor())
2813 return Sema::CXXCopyConstructor;
2815 if (Ctor->isMoveConstructor())
2816 return Sema::CXXMoveConstructor;
2817 } else if (isa<CXXDestructorDecl>(MD)) {
2818 return Sema::CXXDestructor;
2819 } else if (MD->isCopyAssignmentOperator()) {
2820 return Sema::CXXCopyAssignment;
2821 } else if (MD->isMoveAssignmentOperator()) {
2822 return Sema::CXXMoveAssignment;
2825 return Sema::CXXInvalid;
2828 // Determine whether the previous declaration was a definition, implicit
2829 // declaration, or a declaration.
2830 template <typename T>
2831 static std::pair<diag::kind, SourceLocation>
2832 getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
2833 diag::kind PrevDiag;
2834 SourceLocation OldLocation = Old->getLocation();
2835 if (Old->isThisDeclarationADefinition())
2836 PrevDiag = diag::note_previous_definition;
2837 else if (Old->isImplicit()) {
2838 PrevDiag = diag::note_previous_implicit_declaration;
2839 if (OldLocation.isInvalid())
2840 OldLocation = New->getLocation();
2842 PrevDiag = diag::note_previous_declaration;
2843 return std::make_pair(PrevDiag, OldLocation);
2846 /// canRedefineFunction - checks if a function can be redefined. Currently,
2847 /// only extern inline functions can be redefined, and even then only in
2849 static bool canRedefineFunction(const FunctionDecl *FD,
2850 const LangOptions& LangOpts) {
2851 return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
2852 !LangOpts.CPlusPlus &&
2853 FD->isInlineSpecified() &&
2854 FD->getStorageClass() == SC_Extern);
2857 const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
2858 const AttributedType *AT = T->getAs<AttributedType>();
2859 while (AT && !AT->isCallingConv())
2860 AT = AT->getModifiedType()->getAs<AttributedType>();
2864 template <typename T>
2865 static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
2866 const DeclContext *DC = Old->getDeclContext();
2870 LanguageLinkage OldLinkage = Old->getLanguageLinkage();
2871 if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
2873 if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
2878 template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
2879 static bool isExternC(VarTemplateDecl *) { return false; }
2881 /// Check whether a redeclaration of an entity introduced by a
2882 /// using-declaration is valid, given that we know it's not an overload
2883 /// (nor a hidden tag declaration).
2884 template<typename ExpectedDecl>
2885 static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
2886 ExpectedDecl *New) {
2887 // C++11 [basic.scope.declarative]p4:
2888 // Given a set of declarations in a single declarative region, each of
2889 // which specifies the same unqualified name,
2890 // -- they shall all refer to the same entity, or all refer to functions
2891 // and function templates; or
2892 // -- exactly one declaration shall declare a class name or enumeration
2893 // name that is not a typedef name and the other declarations shall all
2894 // refer to the same variable or enumerator, or all refer to functions
2895 // and function templates; in this case the class name or enumeration
2896 // name is hidden (3.3.10).
2898 // C++11 [namespace.udecl]p14:
2899 // If a function declaration in namespace scope or block scope has the
2900 // same name and the same parameter-type-list as a function introduced
2901 // by a using-declaration, and the declarations do not declare the same
2902 // function, the program is ill-formed.
2904 auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
2906 !Old->getDeclContext()->getRedeclContext()->Equals(
2907 New->getDeclContext()->getRedeclContext()) &&
2908 !(isExternC(Old) && isExternC(New)))
2912 S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
2913 S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target);
2914 S.Diag(OldS->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
2920 static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
2921 const FunctionDecl *B) {
2922 assert(A->getNumParams() == B->getNumParams());
2924 auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
2925 const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
2926 const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
2929 return AttrA && AttrB && AttrA->getType() == AttrB->getType();
2932 return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
2935 /// If necessary, adjust the semantic declaration context for a qualified
2936 /// declaration to name the correct inline namespace within the qualifier.
2937 static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
2938 DeclaratorDecl *OldD) {
2939 // The only case where we need to update the DeclContext is when
2940 // redeclaration lookup for a qualified name finds a declaration
2941 // in an inline namespace within the context named by the qualifier:
2943 // inline namespace N { int f(); }
2944 // int ::f(); // Sema DC needs adjusting from :: to N::.
2946 // For unqualified declarations, the semantic context *can* change
2947 // along the redeclaration chain (for local extern declarations,
2948 // extern "C" declarations, and friend declarations in particular).
2949 if (!NewD->getQualifier())
2952 // NewD is probably already in the right context.
2953 auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
2954 auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
2955 if (NamedDC->Equals(SemaDC))
2958 assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||
2959 NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&
2960 "unexpected context for redeclaration");
2962 auto *LexDC = NewD->getLexicalDeclContext();
2963 auto FixSemaDC = [=](NamedDecl *D) {
2966 D->setDeclContext(SemaDC);
2967 D->setLexicalDeclContext(LexDC);
2971 if (auto *FD = dyn_cast<FunctionDecl>(NewD))
2972 FixSemaDC(FD->getDescribedFunctionTemplate());
2973 else if (auto *VD = dyn_cast<VarDecl>(NewD))
2974 FixSemaDC(VD->getDescribedVarTemplate());
2977 /// MergeFunctionDecl - We just parsed a function 'New' from
2978 /// declarator D which has the same name and scope as a previous
2979 /// declaration 'Old'. Figure out how to resolve this situation,
2980 /// merging decls or emitting diagnostics as appropriate.
2982 /// In C++, New and Old must be declarations that are not
2983 /// overloaded. Use IsOverload to determine whether New and Old are
2984 /// overloaded, and to select the Old declaration that New should be
2987 /// Returns true if there was an error, false otherwise.
2988 bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
2989 Scope *S, bool MergeTypeWithOld) {
2990 // Verify the old decl was also a function.
2991 FunctionDecl *Old = OldD->getAsFunction();
2993 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) {
2994 if (New->getFriendObjectKind()) {
2995 Diag(New->getLocation(), diag::err_using_decl_friend);
2996 Diag(Shadow->getTargetDecl()->getLocation(),
2997 diag::note_using_decl_target);
2998 Diag(Shadow->getUsingDecl()->getLocation(),
2999 diag::note_using_decl) << 0;
3003 // Check whether the two declarations might declare the same function.
3004 if (checkUsingShadowRedecl<FunctionDecl>(*this, Shadow, New))
3006 OldD = Old = cast<FunctionDecl>(Shadow->getTargetDecl());
3008 Diag(New->getLocation(), diag::err_redefinition_different_kind)
3009 << New->getDeclName();
3010 notePreviousDefinition(OldD, New->getLocation());
3015 // If the old declaration is invalid, just give up here.
3016 if (Old->isInvalidDecl())
3019 // Disallow redeclaration of some builtins.
3020 if (!getASTContext().canBuiltinBeRedeclared(Old)) {
3021 Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName();
3022 Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
3023 << Old << Old->getType();
3027 diag::kind PrevDiag;
3028 SourceLocation OldLocation;
3029 std::tie(PrevDiag, OldLocation) =
3030 getNoteDiagForInvalidRedeclaration(Old, New);
3032 // Don't complain about this if we're in GNU89 mode and the old function
3033 // is an extern inline function.
3034 // Don't complain about specializations. They are not supposed to have
3036 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
3037 New->getStorageClass() == SC_Static &&
3038 Old->hasExternalFormalLinkage() &&
3039 !New->getTemplateSpecializationInfo() &&
3040 !canRedefineFunction(Old, getLangOpts())) {
3041 if (getLangOpts().MicrosoftExt) {
3042 Diag(New->getLocation(), diag::ext_static_non_static) << New;
3043 Diag(OldLocation, PrevDiag);
3045 Diag(New->getLocation(), diag::err_static_non_static) << New;
3046 Diag(OldLocation, PrevDiag);
3051 if (New->hasAttr<InternalLinkageAttr>() &&
3052 !Old->hasAttr<InternalLinkageAttr>()) {
3053 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
3054 << New->getDeclName();
3055 notePreviousDefinition(Old, New->getLocation());
3056 New->dropAttr<InternalLinkageAttr>();
3059 if (CheckRedeclarationModuleOwnership(New, Old))
3062 if (!getLangOpts().CPlusPlus) {
3063 bool OldOvl = Old->hasAttr<OverloadableAttr>();
3064 if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
3065 Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch)
3068 // Try our best to find a decl that actually has the overloadable
3069 // attribute for the note. In most cases (e.g. programs with only one
3070 // broken declaration/definition), this won't matter.
3072 // FIXME: We could do this if we juggled some extra state in
3073 // OverloadableAttr, rather than just removing it.
3074 const Decl *DiagOld = Old;
3076 auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) {
3077 const auto *A = D->getAttr<OverloadableAttr>();
3078 return A && !A->isImplicit();
3080 // If we've implicitly added *all* of the overloadable attrs to this
3081 // chain, emitting a "previous redecl" note is pointless.
3082 DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
3086 Diag(DiagOld->getLocation(),
3087 diag::note_attribute_overloadable_prev_overload)
3091 New->addAttr(OverloadableAttr::CreateImplicit(Context));
3093 New->dropAttr<OverloadableAttr>();
3097 // If a function is first declared with a calling convention, but is later
3098 // declared or defined without one, all following decls assume the calling
3099 // convention of the first.
3101 // It's OK if a function is first declared without a calling convention,
3102 // but is later declared or defined with the default calling convention.
3104 // To test if either decl has an explicit calling convention, we look for
3105 // AttributedType sugar nodes on the type as written. If they are missing or
3106 // were canonicalized away, we assume the calling convention was implicit.
3108 // Note also that we DO NOT return at this point, because we still have
3109 // other tests to run.
3110 QualType OldQType = Context.getCanonicalType(Old->getType());
3111 QualType NewQType = Context.getCanonicalType(New->getType());
3112 const FunctionType *OldType = cast<FunctionType>(OldQType);
3113 const FunctionType *NewType = cast<FunctionType>(NewQType);
3114 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
3115 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
3116 bool RequiresAdjustment = false;
3118 if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
3119 FunctionDecl *First = Old->getFirstDecl();
3120 const FunctionType *FT =
3121 First->getType().getCanonicalType()->castAs<FunctionType>();
3122 FunctionType::ExtInfo FI = FT->getExtInfo();
3123 bool NewCCExplicit = getCallingConvAttributedType(New->getType());
3124 if (!NewCCExplicit) {
3125 // Inherit the CC from the previous declaration if it was specified
3126 // there but not here.
3127 NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
3128 RequiresAdjustment = true;
3130 // Calling conventions aren't compatible, so complain.
3131 bool FirstCCExplicit = getCallingConvAttributedType(First->getType());
3132 Diag(New->getLocation(), diag::err_cconv_change)
3133 << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
3135 << (!FirstCCExplicit ? "" :
3136 FunctionType::getNameForCallConv(FI.getCC()));
3138 // Put the note on the first decl, since it is the one that matters.
3139 Diag(First->getLocation(), diag::note_previous_declaration);
3144 // FIXME: diagnose the other way around?
3145 if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
3146 NewTypeInfo = NewTypeInfo.withNoReturn(true);
3147 RequiresAdjustment = true;
3150 // Merge regparm attribute.
3151 if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
3152 OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
3153 if (NewTypeInfo.getHasRegParm()) {
3154 Diag(New->getLocation(), diag::err_regparm_mismatch)
3155 << NewType->getRegParmType()
3156 << OldType->getRegParmType();
3157 Diag(OldLocation, diag::note_previous_declaration);
3161 NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm());
3162 RequiresAdjustment = true;
3165 // Merge ns_returns_retained attribute.
3166 if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
3167 if (NewTypeInfo.getProducesResult()) {
3168 Diag(New->getLocation(), diag::err_function_attribute_mismatch)
3169 << "'ns_returns_retained'";
3170 Diag(OldLocation, diag::note_previous_declaration);
3174 NewTypeInfo = NewTypeInfo.withProducesResult(true);
3175 RequiresAdjustment = true;
3178 if (OldTypeInfo.getNoCallerSavedRegs() !=
3179 NewTypeInfo.getNoCallerSavedRegs()) {
3180 if (NewTypeInfo.getNoCallerSavedRegs()) {
3181 AnyX86NoCallerSavedRegistersAttr *Attr =
3182 New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
3183 Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr;
3184 Diag(OldLocation, diag::note_previous_declaration);
3188 NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true);
3189 RequiresAdjustment = true;
3192 if (RequiresAdjustment) {
3193 const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
3194 AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo);
3195 New->setType(QualType(AdjustedType, 0));
3196 NewQType = Context.getCanonicalType(New->getType());
3197 NewType = cast<FunctionType>(NewQType);
3200 // If this redeclaration makes the function inline, we may need to add it to
3201 // UndefinedButUsed.
3202 if (!Old->isInlined() && New->isInlined() &&
3203 !New->hasAttr<GNUInlineAttr>() &&
3204 !getLangOpts().GNUInline &&
3205 Old->isUsed(false) &&
3206 !Old->isDefined() && !New->isThisDeclarationADefinition())
3207 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
3210 // If this redeclaration makes it newly gnu_inline, we don't want to warn
3212 if (New->hasAttr<GNUInlineAttr>() &&
3213 Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
3214 UndefinedButUsed.erase(Old->getCanonicalDecl());
3217 // If pass_object_size params don't match up perfectly, this isn't a valid
3219 if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
3220 !hasIdenticalPassObjectSizeAttrs(Old, New)) {
3221 Diag(New->getLocation(), diag::err_different_pass_object_size_params)
3222 << New->getDeclName();
3223 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3227 if (getLangOpts().CPlusPlus) {
3228 // C++1z [over.load]p2
3229 // Certain function declarations cannot be overloaded:
3230 // -- Function declarations that differ only in the return type,
3231 // the exception specification, or both cannot be overloaded.
3233 // Check the exception specifications match. This may recompute the type of
3234 // both Old and New if it resolved exception specifications, so grab the
3235 // types again after this. Because this updates the type, we do this before
3236 // any of the other checks below, which may update the "de facto" NewQType
3237 // but do not necessarily update the type of New.
3238 if (CheckEquivalentExceptionSpec(Old, New))
3240 OldQType = Context.getCanonicalType(Old->getType());
3241 NewQType = Context.getCanonicalType(New->getType());
3243 // Go back to the type source info to compare the declared return types,
3244 // per C++1y [dcl.type.auto]p13:
3245 // Redeclarations or specializations of a function or function template
3246 // with a declared return type that uses a placeholder type shall also
3247 // use that placeholder, not a deduced type.
3248 QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
3249 QualType NewDeclaredReturnType = New->getDeclaredReturnType();
3250 if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) &&
3251 canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType,
3252 OldDeclaredReturnType)) {
3254 if (NewDeclaredReturnType->isObjCObjectPointerType() &&
3255 OldDeclaredReturnType->isObjCObjectPointerType())
3256 // FIXME: This does the wrong thing for a deduced return type.
3257 ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
3258 if (ResQT.isNull()) {
3259 if (New->isCXXClassMember() && New->isOutOfLine())
3260 Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type)
3261 << New << New->getReturnTypeSourceRange();
3263 Diag(New->getLocation(), diag::err_ovl_diff_return_type)
3264 << New->getReturnTypeSourceRange();
3265 Diag(OldLocation, PrevDiag) << Old << Old->getType()
3266 << Old->getReturnTypeSourceRange();
3273 QualType OldReturnType = OldType->getReturnType();
3274 QualType NewReturnType = cast<FunctionType>(NewQType)->getReturnType();
3275 if (OldReturnType != NewReturnType) {
3276 // If this function has a deduced return type and has already been
3277 // defined, copy the deduced value from the old declaration.
3278 AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
3279 if (OldAT && OldAT->isDeduced()) {
3281 SubstAutoType(New->getType(),
3282 OldAT->isDependentType() ? Context.DependentTy
3283 : OldAT->getDeducedType()));
3284 NewQType = Context.getCanonicalType(
3285 SubstAutoType(NewQType,
3286 OldAT->isDependentType() ? Context.DependentTy
3287 : OldAT->getDeducedType()));
3291 const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
3292 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
3293 if (OldMethod && NewMethod) {
3294 // Preserve triviality.
3295 NewMethod->setTrivial(OldMethod->isTrivial());
3297 // MSVC allows explicit template specialization at class scope:
3298 // 2 CXXMethodDecls referring to the same function will be injected.
3299 // We don't want a redeclaration error.
3300 bool IsClassScopeExplicitSpecialization =
3301 OldMethod->isFunctionTemplateSpecialization() &&
3302 NewMethod->isFunctionTemplateSpecialization();
3303 bool isFriend = NewMethod->getFriendObjectKind();
3305 if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
3306 !IsClassScopeExplicitSpecialization) {
3307 // -- Member function declarations with the same name and the
3308 // same parameter types cannot be overloaded if any of them
3309 // is a static member function declaration.
3310 if (OldMethod->isStatic() != NewMethod->isStatic()) {
3311 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
3312 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3316 // C++ [class.mem]p1:
3317 // [...] A member shall not be declared twice in the
3318 // member-specification, except that a nested class or member
3319 // class template can be declared and then later defined.
3320 if (!inTemplateInstantiation()) {
3322 if (isa<CXXConstructorDecl>(OldMethod))
3323 NewDiag = diag::err_constructor_redeclared;
3324 else if (isa<CXXDestructorDecl>(NewMethod))
3325 NewDiag = diag::err_destructor_redeclared;
3326 else if (isa<CXXConversionDecl>(NewMethod))
3327 NewDiag = diag::err_conv_function_redeclared;
3329 NewDiag = diag::err_member_redeclared;
3331 Diag(New->getLocation(), NewDiag);
3333 Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation)
3334 << New << New->getType();
3336 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3339 // Complain if this is an explicit declaration of a special
3340 // member that was initially declared implicitly.
3342 // As an exception, it's okay to befriend such methods in order
3343 // to permit the implicit constructor/destructor/operator calls.
3344 } else if (OldMethod->isImplicit()) {
3346 NewMethod->setImplicit();
3348 Diag(NewMethod->getLocation(),
3349 diag::err_definition_of_implicitly_declared_member)
3350 << New << getSpecialMember(OldMethod);
3353 } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
3354 Diag(NewMethod->getLocation(),
3355 diag::err_definition_of_explicitly_defaulted_member)
3356 << getSpecialMember(OldMethod);
3361 // C++11 [dcl.attr.noreturn]p1:
3362 // The first declaration of a function shall specify the noreturn
3363 // attribute if any declaration of that function specifies the noreturn
3365 const CXX11NoReturnAttr *NRA = New->getAttr<CXX11NoReturnAttr>();
3366 if (NRA && !Old->hasAttr<CXX11NoReturnAttr>()) {
3367 Diag(NRA->getLocation(), diag::err_noreturn_missing_on_first_decl);
3368 Diag(Old->getFirstDecl()->getLocation(),
3369 diag::note_noreturn_missing_first_decl);
3372 // C++11 [dcl.attr.depend]p2:
3373 // The first declaration of a function shall specify the
3374 // carries_dependency attribute for its declarator-id if any declaration
3375 // of the function specifies the carries_dependency attribute.
3376 const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
3377 if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
3378 Diag(CDA->getLocation(),
3379 diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
3380 Diag(Old->getFirstDecl()->getLocation(),
3381 diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
3385 // All declarations for a function shall agree exactly in both the
3386 // return type and the parameter-type-list.
3387 // We also want to respect all the extended bits except noreturn.
3389 // noreturn should now match unless the old type info didn't have it.
3390 QualType OldQTypeForComparison = OldQType;
3391 if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
3392 auto *OldType = OldQType->castAs<FunctionProtoType>();
3393 const FunctionType *OldTypeForComparison
3394 = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
3395 OldQTypeForComparison = QualType(OldTypeForComparison, 0);
3396 assert(OldQTypeForComparison.isCanonical());
3399 if (haveIncompatibleLanguageLinkages(Old, New)) {
3400 // As a special case, retain the language linkage from previous
3401 // declarations of a friend function as an extension.
3403 // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
3404 // and is useful because there's otherwise no way to specify language
3405 // linkage within class scope.
3407 // Check cautiously as the friend object kind isn't yet complete.
3408 if (New->getFriendObjectKind() != Decl::FOK_None) {
3409 Diag(New->getLocation(), diag::ext_retained_language_linkage) << New;
3410 Diag(OldLocation, PrevDiag);
3412 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
3413 Diag(OldLocation, PrevDiag);
3418 if (OldQTypeForComparison == NewQType)
3419 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3421 // If the types are imprecise (due to dependent constructs in friends or
3422 // local extern declarations), it's OK if they differ. We'll check again
3423 // during instantiation.
3424 if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType))
3427 // Fall through for conflicting redeclarations and redefinitions.
3430 // C: Function types need to be compatible, not identical. This handles
3431 // duplicate function decls like "void f(int); void f(enum X);" properly.
3432 if (!getLangOpts().CPlusPlus &&
3433 Context.typesAreCompatible(OldQType, NewQType)) {
3434 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
3435 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
3436 const FunctionProtoType *OldProto = nullptr;
3437 if (MergeTypeWithOld && isa<FunctionNoProtoType>(NewFuncType) &&
3438 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
3439 // The old declaration provided a function prototype, but the
3440 // new declaration does not. Merge in the prototype.
3441 assert(!OldProto->hasExceptionSpec() && "Exception spec in C");
3442 SmallVector<QualType, 16> ParamTypes(OldProto->param_types());
3444 Context.getFunctionType(NewFuncType->getReturnType(), ParamTypes,
3445 OldProto->getExtProtoInfo());
3446 New->setType(NewQType);
3447 New->setHasInheritedPrototype();
3449 // Synthesize parameters with the same types.
3450 SmallVector<ParmVarDecl*, 16> Params;
3451 for (const auto &ParamType : OldProto->param_types()) {
3452 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, SourceLocation(),
3453 SourceLocation(), nullptr,
3454 ParamType, /*TInfo=*/nullptr,
3456 Param->setScopeInfo(0, Params.size());
3457 Param->setImplicit();
3458 Params.push_back(Param);
3461 New->setParams(Params);
3464 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3467 // GNU C permits a K&R definition to follow a prototype declaration
3468 // if the declared types of the parameters in the K&R definition
3469 // match the types in the prototype declaration, even when the
3470 // promoted types of the parameters from the K&R definition differ
3471 // from the types in the prototype. GCC then keeps the types from
3474 // If a variadic prototype is followed by a non-variadic K&R definition,
3475 // the K&R definition becomes variadic. This is sort of an edge case, but
3476 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and
3478 if (!getLangOpts().CPlusPlus &&
3479 Old->hasPrototype() && !New->hasPrototype() &&
3480 New->getType()->getAs<FunctionProtoType>() &&
3481 Old->getNumParams() == New->getNumParams()) {
3482 SmallVector<QualType, 16> ArgTypes;
3483 SmallVector<GNUCompatibleParamWarning, 16> Warnings;
3484 const FunctionProtoType *OldProto
3485 = Old->getType()->getAs<FunctionProtoType>();
3486 const FunctionProtoType *NewProto
3487 = New->getType()->getAs<FunctionProtoType>();
3489 // Determine whether this is the GNU C extension.
3490 QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
3491 NewProto->getReturnType());
3492 bool LooseCompatible = !MergedReturn.isNull();
3493 for (unsigned Idx = 0, End = Old->getNumParams();
3494 LooseCompatible && Idx != End; ++Idx) {
3495 ParmVarDecl *OldParm = Old->getParamDecl(Idx);
3496 ParmVarDecl *NewParm = New->getParamDecl(Idx);
3497 if (Context.typesAreCompatible(OldParm->getType(),
3498 NewProto->getParamType(Idx))) {
3499 ArgTypes.push_back(NewParm->getType());
3500 } else if (Context.typesAreCompatible(OldParm->getType(),
3502 /*CompareUnqualified=*/true)) {
3503 GNUCompatibleParamWarning Warn = { OldParm, NewParm,
3504 NewProto->getParamType(Idx) };
3505 Warnings.push_back(Warn);
3506 ArgTypes.push_back(NewParm->getType());
3508 LooseCompatible = false;
3511 if (LooseCompatible) {
3512 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
3513 Diag(Warnings[Warn].NewParm->getLocation(),
3514 diag::ext_param_promoted_not_compatible_with_prototype)
3515 << Warnings[Warn].PromotedType
3516 << Warnings[Warn].OldParm->getType();
3517 if (Warnings[Warn].OldParm->getLocation().isValid())
3518 Diag(Warnings[Warn].OldParm->getLocation(),
3519 diag::note_previous_declaration);
3522 if (MergeTypeWithOld)
3523 New->setType(Context.getFunctionType(MergedReturn, ArgTypes,
3524 OldProto->getExtProtoInfo()));
3525 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3528 // Fall through to diagnose conflicting types.
3531 // A function that has already been declared has been redeclared or
3532 // defined with a different type; show an appropriate diagnostic.
3534 // If the previous declaration was an implicitly-generated builtin
3535 // declaration, then at the very least we should use a specialized note.
3537 if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
3538 // If it's actually a library-defined builtin function like 'malloc'
3539 // or 'printf', just warn about the incompatible redeclaration.
3540 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
3541 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
3542 Diag(OldLocation, diag::note_previous_builtin_declaration)
3543 << Old << Old->getType();
3545 // If this is a global redeclaration, just forget hereafter
3546 // about the "builtin-ness" of the function.
3548 // Doing this for local extern declarations is problematic. If
3549 // the builtin declaration remains visible, a second invalid
3550 // local declaration will produce a hard error; if it doesn't
3551 // remain visible, a single bogus local redeclaration (which is
3552 // actually only a warning) could break all the downstream code.
3553 if (!New->getLexicalDeclContext()->isFunctionOrMethod())
3554 New->getIdentifier()->revertBuiltin();
3559 PrevDiag = diag::note_previous_builtin_declaration;
3562 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
3563 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3567 /// Completes the merge of two function declarations that are
3568 /// known to be compatible.
3570 /// This routine handles the merging of attributes and other
3571 /// properties of function declarations from the old declaration to
3572 /// the new declaration, once we know that New is in fact a
3573 /// redeclaration of Old.
3576 bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
3577 Scope *S, bool MergeTypeWithOld) {
3578 // Merge the attributes
3579 mergeDeclAttributes(New, Old);
3581 // Merge "pure" flag.
3585 // Merge "used" flag.
3586 if (Old->getMostRecentDecl()->isUsed(false))
3589 // Merge attributes from the parameters. These can mismatch with K&R
3591 if (New->getNumParams() == Old->getNumParams())
3592 for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
3593 ParmVarDecl *NewParam = New->getParamDecl(i);
3594 ParmVarDecl *OldParam = Old->getParamDecl(i);
3595 mergeParamDeclAttributes(NewParam, OldParam, *this);
3596 mergeParamDeclTypes(NewParam, OldParam, *this);
3599 if (getLangOpts().CPlusPlus)
3600 return MergeCXXFunctionDecl(New, Old, S);
3602 // Merge the function types so the we get the composite types for the return
3603 // and argument types. Per C11 6.2.7/4, only update the type if the old decl
3605 QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
3606 if (!Merged.isNull() && MergeTypeWithOld)
3607 New->setType(Merged);
3612 void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
3613 ObjCMethodDecl *oldMethod) {
3614 // Merge the attributes, including deprecated/unavailable
3615 AvailabilityMergeKind MergeKind =
3616 isa<ObjCProtocolDecl>(oldMethod->getDeclContext())
3617 ? AMK_ProtocolImplementation
3618 : isa<ObjCImplDecl>(newMethod->getDeclContext()) ? AMK_Redeclaration
3621 mergeDeclAttributes(newMethod, oldMethod, MergeKind);
3623 // Merge attributes from the parameters.
3624 ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
3625 oe = oldMethod->param_end();
3626 for (ObjCMethodDecl::param_iterator
3627 ni = newMethod->param_begin(), ne = newMethod->param_end();
3628 ni != ne && oi != oe; ++ni, ++oi)
3629 mergeParamDeclAttributes(*ni, *oi, *this);
3631 CheckObjCMethodOverride(newMethod, oldMethod);
3634 static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
3635 assert(!S.Context.hasSameType(New->getType(), Old->getType()));
3637 S.Diag(New->getLocation(), New->isThisDeclarationADefinition()
3638 ? diag::err_redefinition_different_type
3639 : diag::err_redeclaration_different_type)
3640 << New->getDeclName() << New->getType() << Old->getType();
3642 diag::kind PrevDiag;
3643 SourceLocation OldLocation;
3644 std::tie(PrevDiag, OldLocation)
3645 = getNoteDiagForInvalidRedeclaration(Old, New);
3646 S.Diag(OldLocation, PrevDiag);
3647 New->setInvalidDecl();
3650 /// MergeVarDeclTypes - We parsed a variable 'New' which has the same name and
3651 /// scope as a previous declaration 'Old'. Figure out how to merge their types,
3652 /// emitting diagnostics as appropriate.
3654 /// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back
3655 /// to here in AddInitializerToDecl. We can't check them before the initializer
3657 void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
3658 bool MergeTypeWithOld) {
3659 if (New->isInvalidDecl() || Old->isInvalidDecl())
3663 if (getLangOpts().CPlusPlus) {
3664 if (New->getType()->isUndeducedType()) {
3665 // We don't know what the new type is until the initializer is attached.
3667 } else if (Context.hasSameType(New->getType(), Old->getType())) {
3668 // These could still be something that needs exception specs checked.
3669 return MergeVarDeclExceptionSpecs(New, Old);
3671 // C++ [basic.link]p10:
3672 // [...] the types specified by all declarations referring to a given
3673 // object or function shall be identical, except that declarations for an
3674 // array object can specify array types that differ by the presence or
3675 // absence of a major array bound (8.3.4).
3676 else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
3677 const ArrayType *OldArray = Context.getAsArrayType(Old->getType());
3678 const ArrayType *NewArray = Context.getAsArrayType(New->getType());
3680 // We are merging a variable declaration New into Old. If it has an array
3681 // bound, and that bound differs from Old's bound, we should diagnose the
3683 if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
3684 for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
3685 PrevVD = PrevVD->getPreviousDecl()) {
3686 const ArrayType *PrevVDTy = Context.getAsArrayType(PrevVD->getType());
3687 if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
3690 if (!Context.hasSameType(NewArray, PrevVDTy))
3691 return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
3695 if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
3696 if (Context.hasSameType(OldArray->getElementType(),
3697 NewArray->getElementType()))
3698 MergedT = New->getType();
3700 // FIXME: Check visibility. New is hidden but has a complete type. If New
3701 // has no array bound, it should not inherit one from Old, if Old is not
3703 else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
3704 if (Context.hasSameType(OldArray->getElementType(),
3705 NewArray->getElementType()))
3706 MergedT = Old->getType();
3709 else if (New->getType()->isObjCObjectPointerType() &&
3710 Old->getType()->isObjCObjectPointerType()) {
3711 MergedT = Context.mergeObjCGCQualifiers(New->getType(),
3716 // All declarations that refer to the same object or function shall have
3718 MergedT = Context.mergeTypes(New->getType(), Old->getType());
3720 if (MergedT.isNull()) {
3721 // It's OK if we couldn't merge types if either type is dependent, for a
3722 // block-scope variable. In other cases (static data members of class
3723 // templates, variable templates, ...), we require the types to be
3725 // FIXME: The C++ standard doesn't say anything about this.
3726 if ((New->getType()->isDependentType() ||
3727 Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
3728 // If the old type was dependent, we can't merge with it, so the new type
3729 // becomes dependent for now. We'll reproduce the original type when we
3730 // instantiate the TypeSourceInfo for the variable.
3731 if (!New->getType()->isDependentType() && MergeTypeWithOld)
3732 New->setType(Context.DependentTy);
3735 return diagnoseVarDeclTypeMismatch(*this, New, Old);
3738 // Don't actually update the type on the new declaration if the old
3739 // declaration was an extern declaration in a different scope.
3740 if (MergeTypeWithOld)
3741 New->setType(MergedT);
3744 static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
3745 LookupResult &Previous) {
3747 // For an identifier with internal or external linkage declared
3748 // in a scope in which a prior declaration of that identifier is
3749 // visible, if the prior declaration specifies internal or
3750 // external linkage, the type of the identifier at the later
3751 // declaration becomes the composite type.
3753 // If the variable isn't visible, we do not merge with its type.
3754 if (Previous.isShadowed())
3757 if (S.getLangOpts().CPlusPlus) {
3758 // C++11 [dcl.array]p3:
3759 // If there is a preceding declaration of the entity in the same
3760 // scope in which the bound was specified, an omitted array bound
3761 // is taken to be the same as in that earlier declaration.
3762 return NewVD->isPreviousDeclInSameBlockScope() ||
3763 (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
3764 !NewVD->getLexicalDeclContext()->isFunctionOrMethod());
3766 // If the old declaration was function-local, don't merge with its
3767 // type unless we're in the same function.
3768 return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
3769 OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
3773 /// MergeVarDecl - We just parsed a variable 'New' which has the same name
3774 /// and scope as a previous declaration 'Old'. Figure out how to resolve this
3775 /// situation, merging decls or emitting diagnostics as appropriate.
3777 /// Tentative definition rules (C99 6.9.2p2) are checked by
3778 /// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
3779 /// definitions here, since the initializer hasn't been attached.
3781 void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
3782 // If the new decl is already invalid, don't do any other checking.
3783 if (New->isInvalidDecl())
3786 if (!shouldLinkPossiblyHiddenDecl(Previous, New))
3789 VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();
3791 // Verify the old decl was also a variable or variable template.
3792 VarDecl *Old = nullptr;
3793 VarTemplateDecl *OldTemplate = nullptr;
3794 if (Previous.isSingleResult()) {
3796 OldTemplate = dyn_cast<VarTemplateDecl>(Previous.getFoundDecl());
3797 Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;
3800 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
3801 if (checkUsingShadowRedecl<VarTemplateDecl>(*this, Shadow, NewTemplate))
3802 return New->setInvalidDecl();
3804 Old = dyn_cast<VarDecl>(Previous.getFoundDecl());
3807 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
3808 if (checkUsingShadowRedecl<VarDecl>(*this, Shadow, New))
3809 return New->setInvalidDecl();
3813 Diag(New->getLocation(), diag::err_redefinition_different_kind)
3814 << New->getDeclName();
3815 notePreviousDefinition(Previous.getRepresentativeDecl(),
3816 New->getLocation());
3817 return New->setInvalidDecl();
3820 // Ensure the template parameters are compatible.
3822 !TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
3823 OldTemplate->getTemplateParameters(),
3824 /*Complain=*/true, TPL_TemplateMatch))
3825 return New->setInvalidDecl();
3827 // C++ [class.mem]p1:
3828 // A member shall not be declared twice in the member-specification [...]
3830 // Here, we need only consider static data members.
3831 if (Old->isStaticDataMember() && !New->isOutOfLine()) {
3832 Diag(New->getLocation(), diag::err_duplicate_member)
3833 << New->getIdentifier();
3834 Diag(Old->getLocation(), diag::note_previous_declaration);
3835 New->setInvalidDecl();
3838 mergeDeclAttributes(New, Old);
3839 // Warn if an already-declared variable is made a weak_import in a subsequent
3841 if (New->hasAttr<WeakImportAttr>() &&
3842 Old->getStorageClass() == SC_None &&
3843 !Old->hasAttr<WeakImportAttr>()) {
3844 Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
3845 notePreviousDefinition(Old, New->getLocation());
3846 // Remove weak_import attribute on new declaration.
3847 New->dropAttr<WeakImportAttr>();
3850 if (New->hasAttr<InternalLinkageAttr>() &&
3851 !Old->hasAttr<InternalLinkageAttr>()) {
3852 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
3853 << New->getDeclName();
3854 notePreviousDefinition(Old, New->getLocation());
3855 New->dropAttr<InternalLinkageAttr>();
3859 VarDecl *MostRecent = Old->getMostRecentDecl();
3860 if (MostRecent != Old) {
3861 MergeVarDeclTypes(New, MostRecent,
3862 mergeTypeWithPrevious(*this, New, MostRecent, Previous));
3863 if (New->isInvalidDecl())
3867 MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous));
3868 if (New->isInvalidDecl())
3871 diag::kind PrevDiag;
3872 SourceLocation OldLocation;
3873 std::tie(PrevDiag, OldLocation) =
3874 getNoteDiagForInvalidRedeclaration(Old, New);
3876 // [dcl.stc]p8: Check if we have a non-static decl followed by a static.
3877 if (New->getStorageClass() == SC_Static &&
3878 !New->isStaticDataMember() &&
3879 Old->hasExternalFormalLinkage()) {
3880 if (getLangOpts().MicrosoftExt) {
3881 Diag(New->getLocation(), diag::ext_static_non_static)
3882 << New->getDeclName();
3883 Diag(OldLocation, PrevDiag);
3885 Diag(New->getLocation(), diag::err_static_non_static)
3886 << New->getDeclName();
3887 Diag(OldLocation, PrevDiag);
3888 return New->setInvalidDecl();
3892 // For an identifier declared with the storage-class specifier
3893 // extern in a scope in which a prior declaration of that
3894 // identifier is visible,23) if the prior declaration specifies
3895 // internal or external linkage, the linkage of the identifier at
3896 // the later declaration is the same as the linkage specified at
3897 // the prior declaration. If no prior declaration is visible, or
3898 // if the prior declaration specifies no linkage, then the
3899 // identifier has external linkage.
3900 if (New->hasExternalStorage() && Old->hasLinkage())
3902 else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
3903 !New->isStaticDataMember() &&
3904 Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
3905 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
3906 Diag(OldLocation, PrevDiag);
3907 return New->setInvalidDecl();
3910 // Check if extern is followed by non-extern and vice-versa.
3911 if (New->hasExternalStorage() &&
3912 !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
3913 Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName();
3914 Diag(OldLocation, PrevDiag);
3915 return New->setInvalidDecl();
3917 if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
3918 !New->hasExternalStorage()) {
3919 Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName();
3920 Diag(OldLocation, PrevDiag);
3921 return New->setInvalidDecl();
3924 if (CheckRedeclarationModuleOwnership(New, Old))
3927 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
3929 // FIXME: The test for external storage here seems wrong? We still
3930 // need to check for mismatches.
3931 if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
3932 // Don't complain about out-of-line definitions of static members.
3933 !(Old->getLexicalDeclContext()->isRecord() &&
3934 !New->getLexicalDeclContext()->isRecord())) {
3935 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
3936 Diag(OldLocation, PrevDiag);
3937 return New->setInvalidDecl();
3940 if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
3941 if (VarDecl *Def = Old->getDefinition()) {
3942 // C++1z [dcl.fcn.spec]p4:
3943 // If the definition of a variable appears in a translation unit before
3944 // its first declaration as inline, the program is ill-formed.
3945 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
3946 Diag(Def->getLocation(), diag::note_previous_definition);
3950 // If this redeclaration makes the variable inline, we may need to add it to
3951 // UndefinedButUsed.
3952 if (!Old->isInline() && New->isInline() && Old->isUsed(false) &&
3953 !Old->getDefinition() && !New->isThisDeclarationADefinition())
3954 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
3957 if (New->getTLSKind() != Old->getTLSKind()) {
3958 if (!Old->getTLSKind()) {
3959 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
3960 Diag(OldLocation, PrevDiag);
3961 } else if (!New->getTLSKind()) {
3962 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
3963 Diag(OldLocation, PrevDiag);
3965 // Do not allow redeclaration to change the variable between requiring
3966 // static and dynamic initialization.
3967 // FIXME: GCC allows this, but uses the TLS keyword on the first
3968 // declaration to determine the kind. Do we need to be compatible here?
3969 Diag(New->getLocation(), diag::err_thread_thread_different_kind)
3970 << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
3971 Diag(OldLocation, PrevDiag);
3975 // C++ doesn't have tentative definitions, so go right ahead and check here.
3976 if (getLangOpts().CPlusPlus &&
3977 New->isThisDeclarationADefinition() == VarDecl::Definition) {
3978 if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
3979 Old->getCanonicalDecl()->isConstexpr()) {
3980 // This definition won't be a definition any more once it's been merged.
3981 Diag(New->getLocation(),
3982 diag::warn_deprecated_redundant_constexpr_static_def);
3983 } else if (VarDecl *Def = Old->getDefinition()) {
3984 if (checkVarDeclRedefinition(Def, New))
3989 if (haveIncompatibleLanguageLinkages(Old, New)) {
3990 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
3991 Diag(OldLocation, PrevDiag);
3992 New->setInvalidDecl();
3996 // Merge "used" flag.
3997 if (Old->getMostRecentDecl()->isUsed(false))
4000 // Keep a chain of previous declarations.
4001 New->setPreviousDecl(Old);
4003 NewTemplate->setPreviousDecl(OldTemplate);
4004 adjustDeclContextForDeclaratorDecl(New, Old);
4006 // Inherit access appropriately.
4007 New->setAccess(Old->getAccess());
4009 NewTemplate->setAccess(New->getAccess());
4011 if (Old->isInline())
4012 New->setImplicitlyInline();
4015 void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
4016 SourceManager &SrcMgr = getSourceManager();
4017 auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
4018 auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
4019 auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
4020 auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first);
4021 auto &HSI = PP.getHeaderSearchInfo();
4022 StringRef HdrFilename =
4023 SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));
4025 auto noteFromModuleOrInclude = [&](Module *Mod,
4026 SourceLocation IncLoc) -> bool {
4027 // Redefinition errors with modules are common with non modular mapped
4028 // headers, example: a non-modular header H in module A that also gets
4029 // included directly in a TU. Pointing twice to the same header/definition
4030 // is confusing, try to get better diagnostics when modules is on.
4031 if (IncLoc.isValid()) {
4033 Diag(IncLoc, diag::note_redefinition_modules_same_file)
4034 << HdrFilename.str() << Mod->getFullModuleName();
4035 if (!Mod->DefinitionLoc.isInvalid())
4036 Diag(Mod->DefinitionLoc, diag::note_defined_here)
4037 << Mod->getFullModuleName();
4039 Diag(IncLoc, diag::note_redefinition_include_same_file)
4040 << HdrFilename.str();
4048 // Is it the same file and same offset? Provide more information on why
4049 // this leads to a redefinition error.
4050 bool EmittedDiag = false;
4051 if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
4052 SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
4053 SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
4054 EmittedDiag = noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
4055 EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
4057 // If the header has no guards, emit a note suggesting one.
4058 if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld))
4059 Diag(Old->getLocation(), diag::note_use_ifdef_guards);
4065 // Redefinition coming from different files or couldn't do better above.
4066 if (Old->getLocation().isValid())
4067 Diag(Old->getLocation(), diag::note_previous_definition);
4070 /// We've just determined that \p Old and \p New both appear to be definitions
4071 /// of the same variable. Either diagnose or fix the problem.
4072 bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
4073 if (!hasVisibleDefinition(Old) &&
4074 (New->getFormalLinkage() == InternalLinkage ||
4076 New->getDescribedVarTemplate() ||
4077 New->getNumTemplateParameterLists() ||
4078 New->getDeclContext()->isDependentContext())) {
4079 // The previous definition is hidden, and multiple definitions are
4080 // permitted (in separate TUs). Demote this to a declaration.
4081 New->demoteThisDefinitionToDeclaration();
4083 // Make the canonical definition visible.
4084 if (auto *OldTD = Old->getDescribedVarTemplate())
4085 makeMergedDefinitionVisible(OldTD);
4086 makeMergedDefinitionVisible(Old);
4089 Diag(New->getLocation(), diag::err_redefinition) << New;
4090 notePreviousDefinition(Old, New->getLocation());
4091 New->setInvalidDecl();
4096 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4097 /// no declarator (e.g. "struct foo;") is parsed.
4099 Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4100 RecordDecl *&AnonRecord) {
4101 return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg(), false,
4105 // The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
4106 // disambiguate entities defined in different scopes.
4107 // While the VS2015 ABI fixes potential miscompiles, it is also breaks
4109 // We will pick our mangling number depending on which version of MSVC is being
4111 static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
4112 return LO.isCompatibleWithMSVC(LangOptions::MSVC2015)
4113 ? S->getMSCurManglingNumber()
4114 : S->getMSLastManglingNumber();
4117 void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
4118 if (!Context.getLangOpts().CPlusPlus)
4121 if (isa<CXXRecordDecl>(Tag->getParent())) {
4122 // If this tag is the direct child of a class, number it if
4124 if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
4126 MangleNumberingContext &MCtx =
4127 Context.getManglingNumberContext(Tag->getParent());
4128 Context.setManglingNumber(
4129 Tag, MCtx.getManglingNumber(
4130 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4134 // If this tag isn't a direct child of a class, number it if it is local.
4135 Decl *ManglingContextDecl;
4136 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
4137 Tag->getDeclContext(), ManglingContextDecl)) {
4138 Context.setManglingNumber(
4139 Tag, MCtx->getManglingNumber(
4140 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4144 void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
4145 TypedefNameDecl *NewTD) {
4146 if (TagFromDeclSpec->isInvalidDecl())
4149 // Do nothing if the tag already has a name for linkage purposes.
4150 if (TagFromDeclSpec->hasNameForLinkage())
4153 // A well-formed anonymous tag must always be a TUK_Definition.
4154 assert(TagFromDeclSpec->isThisDeclarationADefinition());
4156 // The type must match the tag exactly; no qualifiers allowed.
4157 if (!Context.hasSameType(NewTD->getUnderlyingType(),
4158 Context.getTagDeclType(TagFromDeclSpec))) {
4159 if (getLangOpts().CPlusPlus)
4160 Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD);
4164 // If we've already computed linkage for the anonymous tag, then
4165 // adding a typedef name for the anonymous decl can change that
4166 // linkage, which might be a serious problem. Diagnose this as
4167 // unsupported and ignore the typedef name. TODO: we should
4168 // pursue this as a language defect and establish a formal rule
4169 // for how to handle it.
4170 if (TagFromDeclSpec->hasLinkageBeenComputed()) {
4171 Diag(NewTD->getLocation(), diag::err_typedef_changes_linkage);
4173 SourceLocation tagLoc = TagFromDeclSpec->getInnerLocStart();
4174 tagLoc = getLocForEndOfToken(tagLoc);
4176 llvm::SmallString<40> textToInsert;
4177 textToInsert += ' ';
4178 textToInsert += NewTD->getIdentifier()->getName();
4179 Diag(tagLoc, diag::note_typedef_changes_linkage)
4180 << FixItHint::CreateInsertion(tagLoc, textToInsert);
4184 // Otherwise, set this is the anon-decl typedef for the tag.
4185 TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
4188 static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) {
4190 case DeclSpec::TST_class:
4192 case DeclSpec::TST_struct:
4194 case DeclSpec::TST_interface:
4196 case DeclSpec::TST_union:
4198 case DeclSpec::TST_enum:
4201 llvm_unreachable("unexpected type specifier");
4205 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4206 /// no declarator (e.g. "struct foo;") is parsed. It also accepts template
4207 /// parameters to cope with template friend declarations.
4209 Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4210 MultiTemplateParamsArg TemplateParams,
4211 bool IsExplicitInstantiation,
4212 RecordDecl *&AnonRecord) {
4213 Decl *TagD = nullptr;
4214 TagDecl *Tag = nullptr;
4215 if (DS.getTypeSpecType() == DeclSpec::TST_class ||
4216 DS.getTypeSpecType() == DeclSpec::TST_struct ||
4217 DS.getTypeSpecType() == DeclSpec::TST_interface ||
4218 DS.getTypeSpecType() == DeclSpec::TST_union ||
4219 DS.getTypeSpecType() == DeclSpec::TST_enum) {
4220 TagD = DS.getRepAsDecl();
4222 if (!TagD) // We probably had an error
4225 // Note that the above type specs guarantee that the
4226 // type rep is a Decl, whereas in many of the others
4228 if (isa<TagDecl>(TagD))
4229 Tag = cast<TagDecl>(TagD);
4230 else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(TagD))
4231 Tag = CTD->getTemplatedDecl();
4235 handleTagNumbering(Tag, S);
4236 Tag->setFreeStanding();
4237 if (Tag->isInvalidDecl())
4241 if (unsigned TypeQuals = DS.getTypeQualifiers()) {
4242 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
4243 // or incomplete types shall not be restrict-qualified."
4244 if (TypeQuals & DeclSpec::TQ_restrict)
4245 Diag(DS.getRestrictSpecLoc(),
4246 diag::err_typecheck_invalid_restrict_not_pointer_noarg)
4247 << DS.getSourceRange();
4250 if (DS.isInlineSpecified())
4251 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
4252 << getLangOpts().CPlusPlus17;
4254 if (DS.isConstexprSpecified()) {
4255 // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
4256 // and definitions of functions and variables.
4258 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
4259 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType());
4261 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_no_declarators);
4262 // Don't emit warnings after this error.
4266 DiagnoseFunctionSpecifiers(DS);
4268 if (DS.isFriendSpecified()) {
4269 // If we're dealing with a decl but not a TagDecl, assume that
4270 // whatever routines created it handled the friendship aspect.
4273 return ActOnFriendTypeDecl(S, DS, TemplateParams);
4276 const CXXScopeSpec &SS = DS.getTypeSpecScope();
4277 bool IsExplicitSpecialization =
4278 !TemplateParams.empty() && TemplateParams.back()->size() == 0;
4279 if (Tag && SS.isNotEmpty() && !Tag->isCompleteDefinition() &&
4280 !IsExplicitInstantiation && !IsExplicitSpecialization &&
4281 !isa<ClassTemplatePartialSpecializationDecl>(Tag)) {
4282 // Per C++ [dcl.type.elab]p1, a class declaration cannot have a
4283 // nested-name-specifier unless it is an explicit instantiation
4284 // or an explicit specialization.
4286 // FIXME: We allow class template partial specializations here too, per the
4287 // obvious intent of DR1819.
4289 // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either.
4290 Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
4291 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange();
4295 // Track whether this decl-specifier declares anything.
4296 bool DeclaresAnything = true;
4298 // Handle anonymous struct definitions.
4299 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
4300 if (!Record->getDeclName() && Record->isCompleteDefinition() &&
4301 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
4302 if (getLangOpts().CPlusPlus ||
4303 Record->getDeclContext()->isRecord()) {
4304 // If CurContext is a DeclContext that can contain statements,
4305 // RecursiveASTVisitor won't visit the decls that
4306 // BuildAnonymousStructOrUnion() will put into CurContext.
4307 // Also store them here so that they can be part of the
4308 // DeclStmt that gets created in this case.
4309 // FIXME: Also return the IndirectFieldDecls created by
4310 // BuildAnonymousStructOr union, for the same reason?
4311 if (CurContext->isFunctionOrMethod())
4312 AnonRecord = Record;
4313 return BuildAnonymousStructOrUnion(S, DS, AS, Record,
4314 Context.getPrintingPolicy());
4317 DeclaresAnything = false;
4322 // A struct-declaration that does not declare an anonymous structure or
4323 // anonymous union shall contain a struct-declarator-list.
4325 // This rule also existed in C89 and C99; the grammar for struct-declaration
4326 // did not permit a struct-declaration without a struct-declarator-list.
4327 if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
4328 DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
4329 // Check for Microsoft C extension: anonymous struct/union member.
4330 // Handle 2 kinds of anonymous struct/union:
4334 // STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct.
4335 // UNION_TYPE; <- where UNION_TYPE is a typedef union.
4336 if ((Tag && Tag->getDeclName()) ||
4337 DS.getTypeSpecType() == DeclSpec::TST_typename) {
4338 RecordDecl *Record = nullptr;
4340 Record = dyn_cast<RecordDecl>(Tag);
4341 else if (const RecordType *RT =
4342 DS.getRepAsType().get()->getAsStructureType())
4343 Record = RT->getDecl();
4344 else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType())
4345 Record = UT->getDecl();
4347 if (Record && getLangOpts().MicrosoftExt) {
4348 Diag(DS.getBeginLoc(), diag::ext_ms_anonymous_record)
4349 << Record->isUnion() << DS.getSourceRange();
4350 return BuildMicrosoftCAnonymousStruct(S, DS, Record);
4353 DeclaresAnything = false;
4357 // Skip all the checks below if we have a type error.
4358 if (DS.getTypeSpecType() == DeclSpec::TST_error ||
4359 (TagD && TagD->isInvalidDecl()))
4362 if (getLangOpts().CPlusPlus &&
4363 DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
4364 if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
4365 if (Enum->enumerator_begin() == Enum->enumerator_end() &&
4366 !Enum->getIdentifier() && !Enum->isInvalidDecl())
4367 DeclaresAnything = false;
4369 if (!DS.isMissingDeclaratorOk()) {
4370 // Customize diagnostic for a typedef missing a name.
4371 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
4372 Diag(DS.getBeginLoc(), diag::ext_typedef_without_a_name)
4373 << DS.getSourceRange();
4375 DeclaresAnything = false;
4378 if (DS.isModulePrivateSpecified() &&
4379 Tag && Tag->getDeclContext()->isFunctionOrMethod())
4380 Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class)
4381 << Tag->getTagKind()
4382 << FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc());
4384 ActOnDocumentableDecl(TagD);
4387 // A declaration [...] shall declare at least a declarator [...], a tag,
4388 // or the members of an enumeration.
4390 // [If there are no declarators], and except for the declaration of an
4391 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
4392 // names into the program, or shall redeclare a name introduced by a
4393 // previous declaration.
4394 if (!DeclaresAnything) {
4395 // In C, we allow this as a (popular) extension / bug. Don't bother
4396 // producing further diagnostics for redundant qualifiers after this.
4397 Diag(DS.getBeginLoc(), diag::ext_no_declarators) << DS.getSourceRange();
4402 // If a storage-class-specifier appears in a decl-specifier-seq, [...] the
4403 // init-declarator-list of the declaration shall not be empty.
4404 // C++ [dcl.fct.spec]p1:
4405 // If a cv-qualifier appears in a decl-specifier-seq, the
4406 // init-declarator-list of the declaration shall not be empty.
4408 // Spurious qualifiers here appear to be valid in C.
4409 unsigned DiagID = diag::warn_standalone_specifier;
4410 if (getLangOpts().CPlusPlus)
4411 DiagID = diag::ext_standalone_specifier;
4413 // Note that a linkage-specification sets a storage class, but
4414 // 'extern "C" struct foo;' is actually valid and not theoretically
4416 if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
4417 if (SCS == DeclSpec::SCS_mutable)
4418 // Since mutable is not a viable storage class specifier in C, there is
4419 // no reason to treat it as an extension. Instead, diagnose as an error.
4420 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember);
4421 else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
4422 Diag(DS.getStorageClassSpecLoc(), DiagID)
4423 << DeclSpec::getSpecifierName(SCS);
4426 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
4427 Diag(DS.getThreadStorageClassSpecLoc(), DiagID)
4428 << DeclSpec::getSpecifierName(TSCS);
4429 if (DS.getTypeQualifiers()) {
4430 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
4431 Diag(DS.getConstSpecLoc(), DiagID) << "const";
4432 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
4433 Diag(DS.getConstSpecLoc(), DiagID) << "volatile";
4434 // Restrict is covered above.
4435 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
4436 Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
4437 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
4438 Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
4441 // Warn about ignored type attributes, for example:
4442 // __attribute__((aligned)) struct A;
4443 // Attributes should be placed after tag to apply to type declaration.
4444 if (!DS.getAttributes().empty()) {
4445 DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
4446 if (TypeSpecType == DeclSpec::TST_class ||
4447 TypeSpecType == DeclSpec::TST_struct ||
4448 TypeSpecType == DeclSpec::TST_interface ||
4449 TypeSpecType == DeclSpec::TST_union ||
4450 TypeSpecType == DeclSpec::TST_enum) {
4451 for (const ParsedAttr &AL : DS.getAttributes())
4452 Diag(AL.getLoc(), diag::warn_declspec_attribute_ignored)
4453 << AL.getName() << GetDiagnosticTypeSpecifierID(TypeSpecType);
4460 /// We are trying to inject an anonymous member into the given scope;
4461 /// check if there's an existing declaration that can't be overloaded.
4463 /// \return true if this is a forbidden redeclaration
4464 static bool CheckAnonMemberRedeclaration(Sema &SemaRef,
4467 DeclarationName Name,
4468 SourceLocation NameLoc,
4470 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName,
4471 Sema::ForVisibleRedeclaration);
4472 if (!SemaRef.LookupName(R, S)) return false;
4474 // Pick a representative declaration.
4475 NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
4476 assert(PrevDecl && "Expected a non-null Decl");
4478 if (!SemaRef.isDeclInScope(PrevDecl, Owner, S))
4481 SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl)
4483 SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
4488 /// InjectAnonymousStructOrUnionMembers - Inject the members of the
4489 /// anonymous struct or union AnonRecord into the owning context Owner
4490 /// and scope S. This routine will be invoked just after we realize
4491 /// that an unnamed union or struct is actually an anonymous union or
4498 /// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
4499 /// // f into the surrounding scope.x
4502 /// This routine is recursive, injecting the names of nested anonymous
4503 /// structs/unions into the owning context and scope as well.
4505 InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
4506 RecordDecl *AnonRecord, AccessSpecifier AS,
4507 SmallVectorImpl<NamedDecl *> &Chaining) {
4508 bool Invalid = false;
4510 // Look every FieldDecl and IndirectFieldDecl with a name.
4511 for (auto *D : AnonRecord->decls()) {
4512 if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
4513 cast<NamedDecl>(D)->getDeclName()) {
4514 ValueDecl *VD = cast<ValueDecl>(D);
4515 if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(),
4517 AnonRecord->isUnion())) {
4518 // C++ [class.union]p2:
4519 // The names of the members of an anonymous union shall be
4520 // distinct from the names of any other entity in the
4521 // scope in which the anonymous union is declared.
4524 // C++ [class.union]p2:
4525 // For the purpose of name lookup, after the anonymous union
4526 // definition, the members of the anonymous union are
4527 // considered to have been defined in the scope in which the
4528 // anonymous union is declared.
4529 unsigned OldChainingSize = Chaining.size();
4530 if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
4531 Chaining.append(IF->chain_begin(), IF->chain_end());
4533 Chaining.push_back(VD);
4535 assert(Chaining.size() >= 2);
4536 NamedDecl **NamedChain =
4537 new (SemaRef.Context)NamedDecl*[Chaining.size()];
4538 for (unsigned i = 0; i < Chaining.size(); i++)
4539 NamedChain[i] = Chaining[i];
4541 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
4542 SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
4543 VD->getType(), {NamedChain, Chaining.size()});
4545 for (const auto *Attr : VD->attrs())
4546 IndirectField->addAttr(Attr->clone(SemaRef.Context));
4548 IndirectField->setAccess(AS);
4549 IndirectField->setImplicit();
4550 SemaRef.PushOnScopeChains(IndirectField, S);
4552 // That includes picking up the appropriate access specifier.
4553 if (AS != AS_none) IndirectField->setAccess(AS);
4555 Chaining.resize(OldChainingSize);
4563 /// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
4564 /// a VarDecl::StorageClass. Any error reporting is up to the caller:
4565 /// illegal input values are mapped to SC_None.
4567 StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
4568 DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
4569 assert(StorageClassSpec != DeclSpec::SCS_typedef &&
4570 "Parser allowed 'typedef' as storage class VarDecl.");
4571 switch (StorageClassSpec) {
4572 case DeclSpec::SCS_unspecified: return SC_None;
4573 case DeclSpec::SCS_extern:
4574 if (DS.isExternInLinkageSpec())
4577 case DeclSpec::SCS_static: return SC_Static;
4578 case DeclSpec::SCS_auto: return SC_Auto;
4579 case DeclSpec::SCS_register: return SC_Register;
4580 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
4581 // Illegal SCSs map to None: error reporting is up to the caller.
4582 case DeclSpec::SCS_mutable: // Fall through.
4583 case DeclSpec::SCS_typedef: return SC_None;
4585 llvm_unreachable("unknown storage class specifier");
4588 static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
4589 assert(Record->hasInClassInitializer());
4591 for (const auto *I : Record->decls()) {
4592 const auto *FD = dyn_cast<FieldDecl>(I);
4593 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
4594 FD = IFD->getAnonField();
4595 if (FD && FD->hasInClassInitializer())
4596 return FD->getLocation();
4599 llvm_unreachable("couldn't find in-class initializer");
4602 static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4603 SourceLocation DefaultInitLoc) {
4604 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4607 S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization);
4608 S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0;
4611 static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4612 CXXRecordDecl *AnonUnion) {
4613 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4616 checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion));
4619 /// BuildAnonymousStructOrUnion - Handle the declaration of an
4620 /// anonymous structure or union. Anonymous unions are a C++ feature
4621 /// (C++ [class.union]) and a C11 feature; anonymous structures
4622 /// are a C11 feature and GNU C++ extension.
4623 Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
4626 const PrintingPolicy &Policy) {
4627 DeclContext *Owner = Record->getDeclContext();
4629 // Diagnose whether this anonymous struct/union is an extension.
4630 if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
4631 Diag(Record->getLocation(), diag::ext_anonymous_union);
4632 else if (!Record->isUnion() && getLangOpts().CPlusPlus)
4633 Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
4634 else if (!Record->isUnion() && !getLangOpts().C11)
4635 Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);
4637 // C and C++ require different kinds of checks for anonymous
4639 bool Invalid = false;
4640 if (getLangOpts().CPlusPlus) {
4641 const char *PrevSpec = nullptr;
4643 if (Record->isUnion()) {
4644 // C++ [class.union]p6:
4645 // C++17 [class.union.anon]p2:
4646 // Anonymous unions declared in a named namespace or in the
4647 // global namespace shall be declared static.
4648 DeclContext *OwnerScope = Owner->getRedeclContext();
4649 if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
4650 (OwnerScope->isTranslationUnit() ||
4651 (OwnerScope->isNamespace() &&
4652 !cast<NamespaceDecl>(OwnerScope)->isAnonymousNamespace()))) {
4653 Diag(Record->getLocation(), diag::err_anonymous_union_not_static)
4654 << FixItHint::CreateInsertion(Record->getLocation(), "static ");
4656 // Recover by adding 'static'.
4657 DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(),
4658 PrevSpec, DiagID, Policy);
4660 // C++ [class.union]p6:
4661 // A storage class is not allowed in a declaration of an
4662 // anonymous union in a class scope.
4663 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
4664 isa<RecordDecl>(Owner)) {
4665 Diag(DS.getStorageClassSpecLoc(),
4666 diag::err_anonymous_union_with_storage_spec)
4667 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
4669 // Recover by removing the storage specifier.
4670 DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified,
4672 PrevSpec, DiagID, Context.getPrintingPolicy());
4676 // Ignore const/volatile/restrict qualifiers.
4677 if (DS.getTypeQualifiers()) {
4678 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
4679 Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified)
4680 << Record->isUnion() << "const"
4681 << FixItHint::CreateRemoval(DS.getConstSpecLoc());
4682 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
4683 Diag(DS.getVolatileSpecLoc(),
4684 diag::ext_anonymous_struct_union_qualified)
4685 << Record->isUnion() << "volatile"
4686 << FixItHint::CreateRemoval(DS.getVolatileSpecLoc());
4687 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
4688 Diag(DS.getRestrictSpecLoc(),
4689 diag::ext_anonymous_struct_union_qualified)
4690 << Record->isUnion() << "restrict"
4691 << FixItHint::CreateRemoval(DS.getRestrictSpecLoc());
4692 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
4693 Diag(DS.getAtomicSpecLoc(),
4694 diag::ext_anonymous_struct_union_qualified)
4695 << Record->isUnion() << "_Atomic"
4696 << FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
4697 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
4698 Diag(DS.getUnalignedSpecLoc(),
4699 diag::ext_anonymous_struct_union_qualified)
4700 << Record->isUnion() << "__unaligned"
4701 << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());
4703 DS.ClearTypeQualifiers();
4706 // C++ [class.union]p2:
4707 // The member-specification of an anonymous union shall only
4708 // define non-static data members. [Note: nested types and
4709 // functions cannot be declared within an anonymous union. ]
4710 for (auto *Mem : Record->decls()) {
4711 if (auto *FD = dyn_cast<FieldDecl>(Mem)) {
4712 // C++ [class.union]p3:
4713 // An anonymous union shall not have private or protected
4714 // members (clause 11).
4715 assert(FD->getAccess() != AS_none);
4716 if (FD->getAccess() != AS_public) {
4717 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
4718 << Record->isUnion() << (FD->getAccess() == AS_protected);
4722 // C++ [class.union]p1
4723 // An object of a class with a non-trivial constructor, a non-trivial
4724 // copy constructor, a non-trivial destructor, or a non-trivial copy
4725 // assignment operator cannot be a member of a union, nor can an
4726 // array of such objects.
4727 if (CheckNontrivialField(FD))
4729 } else if (Mem->isImplicit()) {
4730 // Any implicit members are fine.
4731 } else if (isa<TagDecl>(Mem) && Mem->getDeclContext() != Record) {
4732 // This is a type that showed up in an
4733 // elaborated-type-specifier inside the anonymous struct or
4734 // union, but which actually declares a type outside of the
4735 // anonymous struct or union. It's okay.
4736 } else if (auto *MemRecord = dyn_cast<RecordDecl>(Mem)) {
4737 if (!MemRecord->isAnonymousStructOrUnion() &&
4738 MemRecord->getDeclName()) {
4739 // Visual C++ allows type definition in anonymous struct or union.
4740 if (getLangOpts().MicrosoftExt)
4741 Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type)
4742 << Record->isUnion();
4744 // This is a nested type declaration.
4745 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
4746 << Record->isUnion();
4750 // This is an anonymous type definition within another anonymous type.
4751 // This is a popular extension, provided by Plan9, MSVC and GCC, but
4752 // not part of standard C++.
4753 Diag(MemRecord->getLocation(),
4754 diag::ext_anonymous_record_with_anonymous_type)
4755 << Record->isUnion();
4757 } else if (isa<AccessSpecDecl>(Mem)) {
4758 // Any access specifier is fine.
4759 } else if (isa<StaticAssertDecl>(Mem)) {
4760 // In C++1z, static_assert declarations are also fine.
4762 // We have something that isn't a non-static data
4763 // member. Complain about it.
4764 unsigned DK = diag::err_anonymous_record_bad_member;
4765 if (isa<TypeDecl>(Mem))
4766 DK = diag::err_anonymous_record_with_type;
4767 else if (isa<FunctionDecl>(Mem))
4768 DK = diag::err_anonymous_record_with_function;
4769 else if (isa<VarDecl>(Mem))
4770 DK = diag::err_anonymous_record_with_static;
4772 // Visual C++ allows type definition in anonymous struct or union.
4773 if (getLangOpts().MicrosoftExt &&
4774 DK == diag::err_anonymous_record_with_type)
4775 Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type)
4776 << Record->isUnion();
4778 Diag(Mem->getLocation(), DK) << Record->isUnion();
4784 // C++11 [class.union]p8 (DR1460):
4785 // At most one variant member of a union may have a
4786 // brace-or-equal-initializer.
4787 if (cast<CXXRecordDecl>(Record)->hasInClassInitializer() &&
4789 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Owner),
4790 cast<CXXRecordDecl>(Record));
4793 if (!Record->isUnion() && !Owner->isRecord()) {
4794 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
4795 << getLangOpts().CPlusPlus;
4799 // Mock up a declarator.
4800 Declarator Dc(DS, DeclaratorContext::MemberContext);
4801 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
4802 assert(TInfo && "couldn't build declarator info for anonymous struct/union");
4804 // Create a declaration for this anonymous struct/union.
4805 NamedDecl *Anon = nullptr;
4806 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
4807 Anon = FieldDecl::Create(
4808 Context, OwningClass, DS.getBeginLoc(), Record->getLocation(),
4809 /*IdentifierInfo=*/nullptr, Context.getTypeDeclType(Record), TInfo,
4810 /*BitWidth=*/nullptr, /*Mutable=*/false,
4811 /*InitStyle=*/ICIS_NoInit);
4812 Anon->setAccess(AS);
4813 if (getLangOpts().CPlusPlus)
4814 FieldCollector->Add(cast<FieldDecl>(Anon));
4816 DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
4817 StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
4818 if (SCSpec == DeclSpec::SCS_mutable) {
4819 // mutable can only appear on non-static class members, so it's always
4821 Diag(Record->getLocation(), diag::err_mutable_nonmember);
4826 Anon = VarDecl::Create(Context, Owner, DS.getBeginLoc(),
4827 Record->getLocation(), /*IdentifierInfo=*/nullptr,
4828 Context.getTypeDeclType(Record), TInfo, SC);
4830 // Default-initialize the implicit variable. This initialization will be
4831 // trivial in almost all cases, except if a union member has an in-class
4833 // union { int n = 0; };
4834 ActOnUninitializedDecl(Anon);
4836 Anon->setImplicit();
4838 // Mark this as an anonymous struct/union type.
4839 Record->setAnonymousStructOrUnion(true);
4841 // Add the anonymous struct/union object to the current
4842 // context. We'll be referencing this object when we refer to one of
4844 Owner->addDecl(Anon);
4846 // Inject the members of the anonymous struct/union into the owning
4847 // context and into the identifier resolver chain for name lookup
4849 SmallVector<NamedDecl*, 2> Chain;
4850 Chain.push_back(Anon);
4852 if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, Chain))
4855 if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
4856 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
4857 Decl *ManglingContextDecl;
4858 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
4859 NewVD->getDeclContext(), ManglingContextDecl)) {
4860 Context.setManglingNumber(
4861 NewVD, MCtx->getManglingNumber(
4862 NewVD, getMSManglingNumber(getLangOpts(), S)));
4863 Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
4869 Anon->setInvalidDecl();
4874 /// BuildMicrosoftCAnonymousStruct - Handle the declaration of an
4875 /// Microsoft C anonymous structure.
4876 /// Ref: http://msdn.microsoft.com/en-us/library/z2cx9y4f.aspx
4879 /// struct A { int a; };
4880 /// struct B { struct A; int b; };
4887 Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
4888 RecordDecl *Record) {
4889 assert(Record && "expected a record!");
4891 // Mock up a declarator.
4892 Declarator Dc(DS, DeclaratorContext::TypeNameContext);
4893 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
4894 assert(TInfo && "couldn't build declarator info for anonymous struct");
4896 auto *ParentDecl = cast<RecordDecl>(CurContext);
4897 QualType RecTy = Context.getTypeDeclType(Record);
4899 // Create a declaration for this anonymous struct.
4901 FieldDecl::Create(Context, ParentDecl, DS.getBeginLoc(), DS.getBeginLoc(),
4902 /*IdentifierInfo=*/nullptr, RecTy, TInfo,
4903 /*BitWidth=*/nullptr, /*Mutable=*/false,
4904 /*InitStyle=*/ICIS_NoInit);
4905 Anon->setImplicit();
4907 // Add the anonymous struct object to the current context.
4908 CurContext->addDecl(Anon);
4910 // Inject the members of the anonymous struct into the current
4911 // context and into the identifier resolver chain for name lookup
4913 SmallVector<NamedDecl*, 2> Chain;
4914 Chain.push_back(Anon);
4916 RecordDecl *RecordDef = Record->getDefinition();
4917 if (RequireCompleteType(Anon->getLocation(), RecTy,
4918 diag::err_field_incomplete) ||
4919 InjectAnonymousStructOrUnionMembers(*this, S, CurContext, RecordDef,
4921 Anon->setInvalidDecl();
4922 ParentDecl->setInvalidDecl();
4928 /// GetNameForDeclarator - Determine the full declaration name for the
4929 /// given Declarator.
4930 DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
4931 return GetNameFromUnqualifiedId(D.getName());
4934 /// Retrieves the declaration name from a parsed unqualified-id.
4936 Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
4937 DeclarationNameInfo NameInfo;
4938 NameInfo.setLoc(Name.StartLocation);
4940 switch (Name.getKind()) {
4942 case UnqualifiedIdKind::IK_ImplicitSelfParam:
4943 case UnqualifiedIdKind::IK_Identifier:
4944 NameInfo.setName(Name.Identifier);
4947 case UnqualifiedIdKind::IK_DeductionGuideName: {
4948 // C++ [temp.deduct.guide]p3:
4949 // The simple-template-id shall name a class template specialization.
4950 // The template-name shall be the same identifier as the template-name
4951 // of the simple-template-id.
4952 // These together intend to imply that the template-name shall name a
4954 // FIXME: template<typename T> struct X {};
4955 // template<typename T> using Y = X<T>;
4956 // Y(int) -> Y<int>;
4957 // satisfies these rules but does not name a class template.
4958 TemplateName TN = Name.TemplateName.get().get();
4959 auto *Template = TN.getAsTemplateDecl();
4960 if (!Template || !isa<ClassTemplateDecl>(Template)) {
4961 Diag(Name.StartLocation,
4962 diag::err_deduction_guide_name_not_class_template)
4963 << (int)getTemplateNameKindForDiagnostics(TN) << TN;
4965 Diag(Template->getLocation(), diag::note_template_decl_here);
4966 return DeclarationNameInfo();
4970 Context.DeclarationNames.getCXXDeductionGuideName(Template));
4974 case UnqualifiedIdKind::IK_OperatorFunctionId:
4975 NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
4976 Name.OperatorFunctionId.Operator));
4977 NameInfo.getInfo().CXXOperatorName.BeginOpNameLoc
4978 = Name.OperatorFunctionId.SymbolLocations[0];
4979 NameInfo.getInfo().CXXOperatorName.EndOpNameLoc
4980 = Name.EndLocation.getRawEncoding();
4983 case UnqualifiedIdKind::IK_LiteralOperatorId:
4984 NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
4986 NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
4989 case UnqualifiedIdKind::IK_ConversionFunctionId: {
4990 TypeSourceInfo *TInfo;
4991 QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo);
4993 return DeclarationNameInfo();
4994 NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
4995 Context.getCanonicalType(Ty)));
4996 NameInfo.setNamedTypeInfo(TInfo);
5000 case UnqualifiedIdKind::IK_ConstructorName: {
5001 TypeSourceInfo *TInfo;
5002 QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo);
5004 return DeclarationNameInfo();
5005 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5006 Context.getCanonicalType(Ty)));
5007 NameInfo.setNamedTypeInfo(TInfo);
5011 case UnqualifiedIdKind::IK_ConstructorTemplateId: {
5012 // In well-formed code, we can only have a constructor
5013 // template-id that refers to the current context, so go there
5014 // to find the actual type being constructed.
5015 CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext);
5016 if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
5017 return DeclarationNameInfo();
5019 // Determine the type of the class being constructed.
5020 QualType CurClassType = Context.getTypeDeclType(CurClass);
5022 // FIXME: Check two things: that the template-id names the same type as
5023 // CurClassType, and that the template-id does not occur when the name
5026 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5027 Context.getCanonicalType(CurClassType)));
5028 // FIXME: should we retrieve TypeSourceInfo?
5029 NameInfo.setNamedTypeInfo(nullptr);
5033 case UnqualifiedIdKind::IK_DestructorName: {
5034 TypeSourceInfo *TInfo;
5035 QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo);
5037 return DeclarationNameInfo();
5038 NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
5039 Context.getCanonicalType(Ty)));
5040 NameInfo.setNamedTypeInfo(TInfo);
5044 case UnqualifiedIdKind::IK_TemplateId: {
5045 TemplateName TName = Name.TemplateId->Template.get();
5046 SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
5047 return Context.getNameForTemplate(TName, TNameLoc);
5050 } // switch (Name.getKind())
5052 llvm_unreachable("Unknown name kind");
5055 static QualType getCoreType(QualType Ty) {
5057 if (Ty->isPointerType() || Ty->isReferenceType())
5058 Ty = Ty->getPointeeType();
5059 else if (Ty->isArrayType())
5060 Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
5062 return Ty.withoutLocalFastQualifiers();
5066 /// hasSimilarParameters - Determine whether the C++ functions Declaration
5067 /// and Definition have "nearly" matching parameters. This heuristic is
5068 /// used to improve diagnostics in the case where an out-of-line function
5069 /// definition doesn't match any declaration within the class or namespace.
5070 /// Also sets Params to the list of indices to the parameters that differ
5071 /// between the declaration and the definition. If hasSimilarParameters
5072 /// returns true and Params is empty, then all of the parameters match.
5073 static bool hasSimilarParameters(ASTContext &Context,
5074 FunctionDecl *Declaration,
5075 FunctionDecl *Definition,
5076 SmallVectorImpl<unsigned> &Params) {
5078 if (Declaration->param_size() != Definition->param_size())
5080 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
5081 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
5082 QualType DefParamTy = Definition->getParamDecl(Idx)->getType();
5084 // The parameter types are identical
5085 if (Context.hasSameType(DefParamTy, DeclParamTy))
5088 QualType DeclParamBaseTy = getCoreType(DeclParamTy);
5089 QualType DefParamBaseTy = getCoreType(DefParamTy);
5090 const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
5091 const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();
5093 if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) ||
5094 (DeclTyName && DeclTyName == DefTyName))
5095 Params.push_back(Idx);
5096 else // The two parameters aren't even close
5103 /// NeedsRebuildingInCurrentInstantiation - Checks whether the given
5104 /// declarator needs to be rebuilt in the current instantiation.
5105 /// Any bits of declarator which appear before the name are valid for
5106 /// consideration here. That's specifically the type in the decl spec
5107 /// and the base type in any member-pointer chunks.
5108 static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
5109 DeclarationName Name) {
5110 // The types we specifically need to rebuild are:
5111 // - typenames, typeofs, and decltypes
5112 // - types which will become injected class names
5113 // Of course, we also need to rebuild any type referencing such a
5114 // type. It's safest to just say "dependent", but we call out a
5117 DeclSpec &DS = D.getMutableDeclSpec();
5118 switch (DS.getTypeSpecType()) {
5119 case DeclSpec::TST_typename:
5120 case DeclSpec::TST_typeofType:
5121 case DeclSpec::TST_underlyingType:
5122 case DeclSpec::TST_atomic: {
5123 // Grab the type from the parser.
5124 TypeSourceInfo *TSI = nullptr;
5125 QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
5126 if (T.isNull() || !T->isDependentType()) break;
5128 // Make sure there's a type source info. This isn't really much
5129 // of a waste; most dependent types should have type source info
5130 // attached already.
5132 TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc());
5134 // Rebuild the type in the current instantiation.
5135 TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name);
5136 if (!TSI) return true;
5138 // Store the new type back in the decl spec.
5139 ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI);
5140 DS.UpdateTypeRep(LocType);
5144 case DeclSpec::TST_decltype:
5145 case DeclSpec::TST_typeofExpr: {
5146 Expr *E = DS.getRepAsExpr();
5147 ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
5148 if (Result.isInvalid()) return true;
5149 DS.UpdateExprRep(Result.get());
5154 // Nothing to do for these decl specs.
5158 // It doesn't matter what order we do this in.
5159 for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
5160 DeclaratorChunk &Chunk = D.getTypeObject(I);
5162 // The only type information in the declarator which can come
5163 // before the declaration name is the base type of a member
5165 if (Chunk.Kind != DeclaratorChunk::MemberPointer)
5168 // Rebuild the scope specifier in-place.
5169 CXXScopeSpec &SS = Chunk.Mem.Scope();
5170 if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
5177 Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
5178 D.setFunctionDefinitionKind(FDK_Declaration);
5179 Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());
5181 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
5182 Dcl && Dcl->getDeclContext()->isFileContext())
5183 Dcl->setTopLevelDeclInObjCContainer();
5185 if (getLangOpts().OpenCL)
5186 setCurrentOpenCLExtensionForDecl(Dcl);
5191 /// DiagnoseClassNameShadow - Implement C++ [class.mem]p13:
5192 /// If T is the name of a class, then each of the following shall have a
5193 /// name different from T:
5194 /// - every static data member of class T;
5195 /// - every member function of class T
5196 /// - every member of class T that is itself a type;
5197 /// \returns true if the declaration name violates these rules.
5198 bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
5199 DeclarationNameInfo NameInfo) {
5200 DeclarationName Name = NameInfo.getName();
5202 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC);
5203 while (Record && Record->isAnonymousStructOrUnion())
5204 Record = dyn_cast<CXXRecordDecl>(Record->getParent());
5205 if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
5206 Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name;
5213 /// Diagnose a declaration whose declarator-id has the given
5214 /// nested-name-specifier.
5216 /// \param SS The nested-name-specifier of the declarator-id.
5218 /// \param DC The declaration context to which the nested-name-specifier
5221 /// \param Name The name of the entity being declared.
5223 /// \param Loc The location of the name of the entity being declared.
5225 /// \param IsTemplateId Whether the name is a (simple-)template-id, and thus
5226 /// we're declaring an explicit / partial specialization / instantiation.
5228 /// \returns true if we cannot safely recover from this error, false otherwise.
5229 bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
5230 DeclarationName Name,
5231 SourceLocation Loc, bool IsTemplateId) {
5232 DeclContext *Cur = CurContext;
5233 while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
5234 Cur = Cur->getParent();
5236 // If the user provided a superfluous scope specifier that refers back to the
5237 // class in which the entity is already declared, diagnose and ignore it.
5243 // Note, it was once ill-formed to give redundant qualification in all
5244 // contexts, but that rule was removed by DR482.
5245 if (Cur->Equals(DC)) {
5246 if (Cur->isRecord()) {
5247 Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
5248 : diag::err_member_extra_qualification)
5249 << Name << FixItHint::CreateRemoval(SS.getRange());
5252 Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name;
5257 // Check whether the qualifying scope encloses the scope of the original
5258 // declaration. For a template-id, we perform the checks in
5259 // CheckTemplateSpecializationScope.
5260 if (!Cur->Encloses(DC) && !IsTemplateId) {
5261 if (Cur->isRecord())
5262 Diag(Loc, diag::err_member_qualification)
5263 << Name << SS.getRange();
5264 else if (isa<TranslationUnitDecl>(DC))
5265 Diag(Loc, diag::err_invalid_declarator_global_scope)
5266 << Name << SS.getRange();
5267 else if (isa<FunctionDecl>(Cur))
5268 Diag(Loc, diag::err_invalid_declarator_in_function)
5269 << Name << SS.getRange();
5270 else if (isa<BlockDecl>(Cur))
5271 Diag(Loc, diag::err_invalid_declarator_in_block)
5272 << Name << SS.getRange();
5274 Diag(Loc, diag::err_invalid_declarator_scope)
5275 << Name << cast<NamedDecl>(Cur) << cast<NamedDecl>(DC) << SS.getRange();
5280 if (Cur->isRecord()) {
5281 // Cannot qualify members within a class.
5282 Diag(Loc, diag::err_member_qualification)
5283 << Name << SS.getRange();
5286 // C++ constructors and destructors with incorrect scopes can break
5287 // our AST invariants by having the wrong underlying types. If
5288 // that's the case, then drop this declaration entirely.
5289 if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
5290 Name.getNameKind() == DeclarationName::CXXDestructorName) &&
5291 !Context.hasSameType(Name.getCXXNameType(),
5292 Context.getTypeDeclType(cast<CXXRecordDecl>(Cur))))
5298 // C++11 [dcl.meaning]p1:
5299 // [...] "The nested-name-specifier of the qualified declarator-id shall
5300 // not begin with a decltype-specifer"
5301 NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
5302 while (SpecLoc.getPrefix())
5303 SpecLoc = SpecLoc.getPrefix();
5304 if (dyn_cast_or_null<DecltypeType>(
5305 SpecLoc.getNestedNameSpecifier()->getAsType()))
5306 Diag(Loc, diag::err_decltype_in_declarator)
5307 << SpecLoc.getTypeLoc().getSourceRange();
5312 NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
5313 MultiTemplateParamsArg TemplateParamLists) {
5314 // TODO: consider using NameInfo for diagnostic.
5315 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
5316 DeclarationName Name = NameInfo.getName();
5318 // All of these full declarators require an identifier. If it doesn't have
5319 // one, the ParsedFreeStandingDeclSpec action should be used.
5320 if (D.isDecompositionDeclarator()) {
5321 return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
5323 if (!D.isInvalidType()) // Reject this if we think it is valid.
5324 Diag(D.getDeclSpec().getBeginLoc(), diag::err_declarator_need_ident)
5325 << D.getDeclSpec().getSourceRange() << D.getSourceRange();
5327 } else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType))
5330 // The scope passed in may not be a decl scope. Zip up the scope tree until
5331 // we find one that is.
5332 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5333 (S->getFlags() & Scope::TemplateParamScope) != 0)
5336 DeclContext *DC = CurContext;
5337 if (D.getCXXScopeSpec().isInvalid())
5339 else if (D.getCXXScopeSpec().isSet()) {
5340 if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(),
5341 UPPC_DeclarationQualifier))
5344 bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
5345 DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext);
5346 if (!DC || isa<EnumDecl>(DC)) {
5347 // If we could not compute the declaration context, it's because the
5348 // declaration context is dependent but does not refer to a class,
5349 // class template, or class template partial specialization. Complain
5350 // and return early, to avoid the coming semantic disaster.
5351 Diag(D.getIdentifierLoc(),
5352 diag::err_template_qualified_declarator_no_match)
5353 << D.getCXXScopeSpec().getScopeRep()
5354 << D.getCXXScopeSpec().getRange();
5357 bool IsDependentContext = DC->isDependentContext();
5359 if (!IsDependentContext &&
5360 RequireCompleteDeclContext(D.getCXXScopeSpec(), DC))
5363 // If a class is incomplete, do not parse entities inside it.
5364 if (isa<CXXRecordDecl>(DC) && !cast<CXXRecordDecl>(DC)->hasDefinition()) {
5365 Diag(D.getIdentifierLoc(),
5366 diag::err_member_def_undefined_record)
5367 << Name << DC << D.getCXXScopeSpec().getRange();
5370 if (!D.getDeclSpec().isFriendSpecified()) {
5371 if (diagnoseQualifiedDeclaration(
5372 D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(),
5373 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) {
5381 // Check whether we need to rebuild the type of the given
5382 // declaration in the current instantiation.
5383 if (EnteringContext && IsDependentContext &&
5384 TemplateParamLists.size() != 0) {
5385 ContextRAII SavedContext(*this, DC);
5386 if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name))
5391 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
5392 QualType R = TInfo->getType();
5394 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
5395 UPPC_DeclarationType))
5398 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
5399 forRedeclarationInCurContext());
5401 // See if this is a redefinition of a variable in the same scope.
5402 if (!D.getCXXScopeSpec().isSet()) {
5403 bool IsLinkageLookup = false;
5404 bool CreateBuiltins = false;
5406 // If the declaration we're planning to build will be a function
5407 // or object with linkage, then look for another declaration with
5408 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
5410 // If the declaration we're planning to build will be declared with
5411 // external linkage in the translation unit, create any builtin with
5413 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
5415 else if (CurContext->isFunctionOrMethod() &&
5416 (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
5417 R->isFunctionType())) {
5418 IsLinkageLookup = true;
5420 CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
5421 } else if (CurContext->getRedeclContext()->isTranslationUnit() &&
5422 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
5423 CreateBuiltins = true;
5425 if (IsLinkageLookup) {
5426 Previous.clear(LookupRedeclarationWithLinkage);
5427 Previous.setRedeclarationKind(ForExternalRedeclaration);
5430 LookupName(Previous, S, CreateBuiltins);
5431 } else { // Something like "int foo::x;"
5432 LookupQualifiedName(Previous, DC);
5434 // C++ [dcl.meaning]p1:
5435 // When the declarator-id is qualified, the declaration shall refer to a
5436 // previously declared member of the class or namespace to which the
5437 // qualifier refers (or, in the case of a namespace, of an element of the
5438 // inline namespace set of that namespace (7.3.1)) or to a specialization
5441 // Note that we already checked the context above, and that we do not have
5442 // enough information to make sure that Previous contains the declaration
5443 // we want to match. For example, given:
5450 // void X::f(int) { } // ill-formed
5452 // In this case, Previous will point to the overload set
5453 // containing the two f's declared in X, but neither of them
5456 // C++ [dcl.meaning]p1:
5457 // [...] the member shall not merely have been introduced by a
5458 // using-declaration in the scope of the class or namespace nominated by
5459 // the nested-name-specifier of the declarator-id.
5460 RemoveUsingDecls(Previous);
5463 if (Previous.isSingleResult() &&
5464 Previous.getFoundDecl()->isTemplateParameter()) {
5465 // Maybe we will complain about the shadowed template parameter.
5466 if (!D.isInvalidType())
5467 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
5468 Previous.getFoundDecl());
5470 // Just pretend that we didn't see the previous declaration.
5474 if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
5475 // Forget that the previous declaration is the injected-class-name.
5478 // In C++, the previous declaration we find might be a tag type
5479 // (class or enum). In this case, the new declaration will hide the
5480 // tag type. Note that this applies to functions, function templates, and
5481 // variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
5482 if (Previous.isSingleTagDecl() &&
5483 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
5484 (TemplateParamLists.size() == 0 || R->isFunctionType()))
5487 // Check that there are no default arguments other than in the parameters
5488 // of a function declaration (C++ only).
5489 if (getLangOpts().CPlusPlus)
5490 CheckExtraCXXDefaultArguments(D);
5494 bool AddToScope = true;
5495 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
5496 if (TemplateParamLists.size()) {
5497 Diag(D.getIdentifierLoc(), diag::err_template_typedef);
5501 New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
5502 } else if (R->isFunctionType()) {
5503 New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
5507 New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
5514 // If this has an identifier and is not a function template specialization,
5515 // add it to the scope stack.
5516 if (New->getDeclName() && AddToScope)
5517 PushOnScopeChains(New, S);
5519 if (isInOpenMPDeclareTargetContext())
5520 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
5525 /// Helper method to turn variable array types into constant array
5526 /// types in certain situations which would otherwise be errors (for
5527 /// GCC compatibility).
5528 static QualType TryToFixInvalidVariablyModifiedType(QualType T,
5529 ASTContext &Context,
5530 bool &SizeIsNegative,
5531 llvm::APSInt &Oversized) {
5532 // This method tries to turn a variable array into a constant
5533 // array even when the size isn't an ICE. This is necessary
5534 // for compatibility with code that depends on gcc's buggy
5535 // constant expression folding, like struct {char x[(int)(char*)2];}
5536 SizeIsNegative = false;
5539 if (T->isDependentType())
5542 QualifierCollector Qs;
5543 const Type *Ty = Qs.strip(T);
5545 if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) {
5546 QualType Pointee = PTy->getPointeeType();
5547 QualType FixedType =
5548 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative,
5550 if (FixedType.isNull()) return FixedType;
5551 FixedType = Context.getPointerType(FixedType);
5552 return Qs.apply(Context, FixedType);
5554 if (const ParenType* PTy = dyn_cast<ParenType>(Ty)) {
5555 QualType Inner = PTy->getInnerType();
5556 QualType FixedType =
5557 TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative,
5559 if (FixedType.isNull()) return FixedType;
5560 FixedType = Context.getParenType(FixedType);
5561 return Qs.apply(Context, FixedType);
5564 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
5567 // FIXME: We should probably handle this case
5568 if (VLATy->getElementType()->isVariablyModifiedType())
5571 Expr::EvalResult Result;
5572 if (!VLATy->getSizeExpr() ||
5573 !VLATy->getSizeExpr()->EvaluateAsInt(Result, Context))
5576 llvm::APSInt Res = Result.Val.getInt();
5578 // Check whether the array size is negative.
5579 if (Res.isSigned() && Res.isNegative()) {
5580 SizeIsNegative = true;
5584 // Check whether the array is too large to be addressed.
5585 unsigned ActiveSizeBits
5586 = ConstantArrayType::getNumAddressingBits(Context, VLATy->getElementType(),
5588 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
5593 return Context.getConstantArrayType(VLATy->getElementType(),
5594 Res, ArrayType::Normal, 0);
5598 FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
5599 SrcTL = SrcTL.getUnqualifiedLoc();
5600 DstTL = DstTL.getUnqualifiedLoc();
5601 if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
5602 PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
5603 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(),
5604 DstPTL.getPointeeLoc());
5605 DstPTL.setStarLoc(SrcPTL.getStarLoc());
5608 if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
5609 ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
5610 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(),
5611 DstPTL.getInnerLoc());
5612 DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
5613 DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
5616 ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
5617 ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
5618 TypeLoc SrcElemTL = SrcATL.getElementLoc();
5619 TypeLoc DstElemTL = DstATL.getElementLoc();
5620 DstElemTL.initializeFullCopy(SrcElemTL);
5621 DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
5622 DstATL.setSizeExpr(SrcATL.getSizeExpr());
5623 DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
5626 /// Helper method to turn variable array types into constant array
5627 /// types in certain situations which would otherwise be errors (for
5628 /// GCC compatibility).
5629 static TypeSourceInfo*
5630 TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
5631 ASTContext &Context,
5632 bool &SizeIsNegative,
5633 llvm::APSInt &Oversized) {
5635 = TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context,
5636 SizeIsNegative, Oversized);
5637 if (FixedTy.isNull())
5639 TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy);
5640 FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(),
5641 FixedTInfo->getTypeLoc());
5645 /// Register the given locally-scoped extern "C" declaration so
5646 /// that it can be found later for redeclarations. We include any extern "C"
5647 /// declaration that is not visible in the translation unit here, not just
5648 /// function-scope declarations.
5650 Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) {
5651 if (!getLangOpts().CPlusPlus &&
5652 ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit())
5653 // Don't need to track declarations in the TU in C.
5656 // Note that we have a locally-scoped external with this name.
5657 Context.getExternCContextDecl()->makeDeclVisibleInContext(ND);
5660 NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) {
5661 // FIXME: We can have multiple results via __attribute__((overloadable)).
5662 auto Result = Context.getExternCContextDecl()->lookup(Name);
5663 return Result.empty() ? nullptr : *Result.begin();
5666 /// Diagnose function specifiers on a declaration of an identifier that
5667 /// does not identify a function.
5668 void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) {
5669 // FIXME: We should probably indicate the identifier in question to avoid
5670 // confusion for constructs like "virtual int a(), b;"
5671 if (DS.isVirtualSpecified())
5672 Diag(DS.getVirtualSpecLoc(),
5673 diag::err_virtual_non_function);
5675 if (DS.isExplicitSpecified())
5676 Diag(DS.getExplicitSpecLoc(),
5677 diag::err_explicit_non_function);
5679 if (DS.isNoreturnSpecified())
5680 Diag(DS.getNoreturnSpecLoc(),
5681 diag::err_noreturn_non_function);
5685 Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
5686 TypeSourceInfo *TInfo, LookupResult &Previous) {
5687 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
5688 if (D.getCXXScopeSpec().isSet()) {
5689 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator)
5690 << D.getCXXScopeSpec().getRange();
5692 // Pretend we didn't see the scope specifier.
5697 DiagnoseFunctionSpecifiers(D.getDeclSpec());
5699 if (D.getDeclSpec().isInlineSpecified())
5700 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
5701 << getLangOpts().CPlusPlus17;
5702 if (D.getDeclSpec().isConstexprSpecified())
5703 Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_invalid_constexpr)
5706 if (D.getName().Kind != UnqualifiedIdKind::IK_Identifier) {
5707 if (D.getName().Kind == UnqualifiedIdKind::IK_DeductionGuideName)
5708 Diag(D.getName().StartLocation,
5709 diag::err_deduction_guide_invalid_specifier)
5712 Diag(D.getName().StartLocation, diag::err_typedef_not_identifier)
5713 << D.getName().getSourceRange();
5717 TypedefDecl *NewTD = ParseTypedefDecl(S, D, TInfo->getType(), TInfo);
5718 if (!NewTD) return nullptr;
5720 // Handle attributes prior to checking for duplicates in MergeVarDecl
5721 ProcessDeclAttributes(S, NewTD, D);
5723 CheckTypedefForVariablyModifiedType(S, NewTD);
5725 bool Redeclaration = D.isRedeclaration();
5726 NamedDecl *ND = ActOnTypedefNameDecl(S, DC, NewTD, Previous, Redeclaration);
5727 D.setRedeclaration(Redeclaration);
5732 Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) {
5733 // C99 6.7.7p2: If a typedef name specifies a variably modified type
5734 // then it shall have block scope.
5735 // Note that variably modified types must be fixed before merging the decl so
5736 // that redeclarations will match.
5737 TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo();
5738 QualType T = TInfo->getType();
5739 if (T->isVariablyModifiedType()) {
5740 setFunctionHasBranchProtectedScope();
5742 if (S->getFnParent() == nullptr) {
5743 bool SizeIsNegative;
5744 llvm::APSInt Oversized;
5745 TypeSourceInfo *FixedTInfo =
5746 TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
5750 Diag(NewTD->getLocation(), diag::warn_illegal_constant_array_size);
5751 NewTD->setTypeSourceInfo(FixedTInfo);
5754 Diag(NewTD->getLocation(), diag::err_typecheck_negative_array_size);
5755 else if (T->isVariableArrayType())
5756 Diag(NewTD->getLocation(), diag::err_vla_decl_in_file_scope);
5757 else if (Oversized.getBoolValue())
5758 Diag(NewTD->getLocation(), diag::err_array_too_large)
5759 << Oversized.toString(10);
5761 Diag(NewTD->getLocation(), diag::err_vm_decl_in_file_scope);
5762 NewTD->setInvalidDecl();
5768 /// ActOnTypedefNameDecl - Perform semantic checking for a declaration which
5769 /// declares a typedef-name, either using the 'typedef' type specifier or via
5770 /// a C++0x [dcl.typedef]p2 alias-declaration: 'using T = A;'.
5772 Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
5773 LookupResult &Previous, bool &Redeclaration) {
5775 // Find the shadowed declaration before filtering for scope.
5776 NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous);
5778 // Merge the decl with the existing one if appropriate. If the decl is
5779 // in an outer scope, it isn't the same thing.
5780 FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false,
5781 /*AllowInlineNamespace*/false);
5782 filterNonConflictingPreviousTypedefDecls(*this, NewTD, Previous);
5783 if (!Previous.empty()) {
5784 Redeclaration = true;
5785 MergeTypedefNameDecl(S, NewTD, Previous);
5788 if (ShadowedDecl && !Redeclaration)
5789 CheckShadow(NewTD, ShadowedDecl, Previous);
5791 // If this is the C FILE type, notify the AST context.
5792 if (IdentifierInfo *II = NewTD->getIdentifier())
5793 if (!NewTD->isInvalidDecl() &&
5794 NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
5795 if (II->isStr("FILE"))
5796 Context.setFILEDecl(NewTD);
5797 else if (II->isStr("jmp_buf"))
5798 Context.setjmp_bufDecl(NewTD);
5799 else if (II->isStr("sigjmp_buf"))
5800 Context.setsigjmp_bufDecl(NewTD);
5801 else if (II->isStr("ucontext_t"))
5802 Context.setucontext_tDecl(NewTD);
5808 /// Determines whether the given declaration is an out-of-scope
5809 /// previous declaration.
5811 /// This routine should be invoked when name lookup has found a
5812 /// previous declaration (PrevDecl) that is not in the scope where a
5813 /// new declaration by the same name is being introduced. If the new
5814 /// declaration occurs in a local scope, previous declarations with
5815 /// linkage may still be considered previous declarations (C99
5816 /// 6.2.2p4-5, C++ [basic.link]p6).
5818 /// \param PrevDecl the previous declaration found by name
5821 /// \param DC the context in which the new declaration is being
5824 /// \returns true if PrevDecl is an out-of-scope previous declaration
5825 /// for a new delcaration with the same name.
5827 isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
5828 ASTContext &Context) {
5832 if (!PrevDecl->hasLinkage())
5835 if (Context.getLangOpts().CPlusPlus) {
5836 // C++ [basic.link]p6:
5837 // If there is a visible declaration of an entity with linkage
5838 // having the same name and type, ignoring entities declared
5839 // outside the innermost enclosing namespace scope, the block
5840 // scope declaration declares that same entity and receives the
5841 // linkage of the previous declaration.
5842 DeclContext *OuterContext = DC->getRedeclContext();
5843 if (!OuterContext->isFunctionOrMethod())
5844 // This rule only applies to block-scope declarations.
5847 DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
5848 if (PrevOuterContext->isRecord())
5849 // We found a member function: ignore it.
5852 // Find the innermost enclosing namespace for the new and
5853 // previous declarations.
5854 OuterContext = OuterContext->getEnclosingNamespaceContext();
5855 PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext();
5857 // The previous declaration is in a different namespace, so it
5858 // isn't the same function.
5859 if (!OuterContext->Equals(PrevOuterContext))
5866 static void SetNestedNameSpecifier(Sema &S, DeclaratorDecl *DD, Declarator &D) {
5867 CXXScopeSpec &SS = D.getCXXScopeSpec();
5868 if (!SS.isSet()) return;
5869 DD->setQualifierInfo(SS.getWithLocInContext(S.Context));
5872 bool Sema::inferObjCARCLifetime(ValueDecl *decl) {
5873 QualType type = decl->getType();
5874 Qualifiers::ObjCLifetime lifetime = type.getObjCLifetime();
5875 if (lifetime == Qualifiers::OCL_Autoreleasing) {
5876 // Various kinds of declaration aren't allowed to be __autoreleasing.
5877 unsigned kind = -1U;
5878 if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
5879 if (var->hasAttr<BlocksAttr>())
5880 kind = 0; // __block
5881 else if (!var->hasLocalStorage())
5883 } else if (isa<ObjCIvarDecl>(decl)) {
5885 } else if (isa<FieldDecl>(decl)) {
5890 Diag(decl->getLocation(), diag::err_arc_autoreleasing_var)
5893 } else if (lifetime == Qualifiers::OCL_None) {
5894 // Try to infer lifetime.
5895 if (!type->isObjCLifetimeType())
5898 lifetime = type->getObjCARCImplicitLifetime();
5899 type = Context.getLifetimeQualifiedType(type, lifetime);
5900 decl->setType(type);
5903 if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
5904 // Thread-local variables cannot have lifetime.
5905 if (lifetime && lifetime != Qualifiers::OCL_ExplicitNone &&
5906 var->getTLSKind()) {
5907 Diag(var->getLocation(), diag::err_arc_thread_ownership)
5916 static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
5917 // Ensure that an auto decl is deduced otherwise the checks below might cache
5918 // the wrong linkage.
5919 assert(S.ParsingInitForAutoVars.count(&ND) == 0);
5921 // 'weak' only applies to declarations with external linkage.
5922 if (WeakAttr *Attr = ND.getAttr<WeakAttr>()) {
5923 if (!ND.isExternallyVisible()) {
5924 S.Diag(Attr->getLocation(), diag::err_attribute_weak_static);
5925 ND.dropAttr<WeakAttr>();
5928 if (WeakRefAttr *Attr = ND.getAttr<WeakRefAttr>()) {
5929 if (ND.isExternallyVisible()) {
5930 S.Diag(Attr->getLocation(), diag::err_attribute_weakref_not_static);
5931 ND.dropAttr<WeakRefAttr>();
5932 ND.dropAttr<AliasAttr>();
5936 if (auto *VD = dyn_cast<VarDecl>(&ND)) {
5937 if (VD->hasInit()) {
5938 if (const auto *Attr = VD->getAttr<AliasAttr>()) {
5939 assert(VD->isThisDeclarationADefinition() &&
5940 !VD->isExternallyVisible() && "Broken AliasAttr handled late!");
5941 S.Diag(Attr->getLocation(), diag::err_alias_is_definition) << VD << 0;
5942 VD->dropAttr<AliasAttr>();
5947 // 'selectany' only applies to externally visible variable declarations.
5948 // It does not apply to functions.
5949 if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) {
5950 if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) {
5951 S.Diag(Attr->getLocation(),
5952 diag::err_attribute_selectany_non_extern_data);
5953 ND.dropAttr<SelectAnyAttr>();
5957 if (const InheritableAttr *Attr = getDLLAttr(&ND)) {
5958 // dll attributes require external linkage. Static locals may have external
5959 // linkage but still cannot be explicitly imported or exported.
5960 auto *VD = dyn_cast<VarDecl>(&ND);
5961 if (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())) {
5962 S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
5964 ND.setInvalidDecl();
5968 // Virtual functions cannot be marked as 'notail'.
5969 if (auto *Attr = ND.getAttr<NotTailCalledAttr>())
5970 if (auto *MD = dyn_cast<CXXMethodDecl>(&ND))
5971 if (MD->isVirtual()) {
5972 S.Diag(ND.getLocation(),
5973 diag::err_invalid_attribute_on_virtual_function)
5975 ND.dropAttr<NotTailCalledAttr>();
5978 // Check the attributes on the function type, if any.
5979 if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
5980 // Don't declare this variable in the second operand of the for-statement;
5981 // GCC miscompiles that by ending its lifetime before evaluating the
5982 // third operand. See gcc.gnu.org/PR86769.
5983 AttributedTypeLoc ATL;
5984 for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
5985 (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
5986 TL = ATL.getModifiedLoc()) {
5987 // The [[lifetimebound]] attribute can be applied to the implicit object
5988 // parameter of a non-static member function (other than a ctor or dtor)
5989 // by applying it to the function type.
5990 if (const auto *A = ATL.getAttrAs<LifetimeBoundAttr>()) {
5991 const auto *MD = dyn_cast<CXXMethodDecl>(FD);
5992 if (!MD || MD->isStatic()) {
5993 S.Diag(A->getLocation(), diag::err_lifetimebound_no_object_param)
5994 << !MD << A->getRange();
5995 } else if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD)) {
5996 S.Diag(A->getLocation(), diag::err_lifetimebound_ctor_dtor)
5997 << isa<CXXDestructorDecl>(MD) << A->getRange();
6004 static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
6006 bool IsSpecialization,
6007 bool IsDefinition) {
6008 if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
6011 bool IsTemplate = false;
6012 if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(OldDecl)) {
6013 OldDecl = OldTD->getTemplatedDecl();
6015 if (!IsSpecialization)
6016 IsDefinition = false;
6018 if (TemplateDecl *NewTD = dyn_cast<TemplateDecl>(NewDecl)) {
6019 NewDecl = NewTD->getTemplatedDecl();
6023 if (!OldDecl || !NewDecl)
6026 const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();
6027 const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();
6028 const DLLImportAttr *NewImportAttr = NewDecl->getAttr<DLLImportAttr>();
6029 const DLLExportAttr *NewExportAttr = NewDecl->getAttr<DLLExportAttr>();
6031 // dllimport and dllexport are inheritable attributes so we have to exclude
6032 // inherited attribute instances.
6033 bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) ||
6034 (NewExportAttr && !NewExportAttr->isInherited());
6036 // A redeclaration is not allowed to add a dllimport or dllexport attribute,
6037 // the only exception being explicit specializations.
6038 // Implicitly generated declarations are also excluded for now because there
6039 // is no other way to switch these to use dllimport or dllexport.
6040 bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr;
6042 if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {
6043 // Allow with a warning for free functions and global variables.
6044 bool JustWarn = false;
6045 if (!OldDecl->isCXXClassMember()) {
6046 auto *VD = dyn_cast<VarDecl>(OldDecl);
6047 if (VD && !VD->getDescribedVarTemplate())
6049 auto *FD = dyn_cast<FunctionDecl>(OldDecl);
6050 if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate)
6054 // We cannot change a declaration that's been used because IR has already
6055 // been emitted. Dllimported functions will still work though (modulo
6056 // address equality) as they can use the thunk.
6057 if (OldDecl->isUsed())
6058 if (!isa<FunctionDecl>(OldDecl) || !NewImportAttr)
6061 unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration
6062 : diag::err_attribute_dll_redeclaration;
6063 S.Diag(NewDecl->getLocation(), DiagID)
6065 << (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr);
6066 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6068 NewDecl->setInvalidDecl();
6073 // A redeclaration is not allowed to drop a dllimport attribute, the only
6074 // exceptions being inline function definitions (except for function
6075 // templates), local extern declarations, qualified friend declarations or
6076 // special MSVC extension: in the last case, the declaration is treated as if
6077 // it were marked dllexport.
6078 bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
6079 bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft();
6080 if (const auto *VD = dyn_cast<VarDecl>(NewDecl)) {
6081 // Ignore static data because out-of-line definitions are diagnosed
6083 IsStaticDataMember = VD->isStaticDataMember();
6084 IsDefinition = VD->isThisDeclarationADefinition(S.Context) !=
6085 VarDecl::DeclarationOnly;
6086 } else if (const auto *FD = dyn_cast<FunctionDecl>(NewDecl)) {
6087 IsInline = FD->isInlined();
6088 IsQualifiedFriend = FD->getQualifier() &&
6089 FD->getFriendObjectKind() == Decl::FOK_Declared;
6092 if (OldImportAttr && !HasNewAttr &&
6093 (!IsInline || (IsMicrosoft && IsTemplate)) && !IsStaticDataMember &&
6094 !NewDecl->isLocalExternDecl() && !IsQualifiedFriend) {
6095 if (IsMicrosoft && IsDefinition) {
6096 S.Diag(NewDecl->getLocation(),
6097 diag::warn_redeclaration_without_import_attribute)
6099 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6100 NewDecl->dropAttr<DLLImportAttr>();
6101 NewDecl->addAttr(::new (S.Context) DLLExportAttr(
6102 NewImportAttr->getRange(), S.Context,
6103 NewImportAttr->getSpellingListIndex()));
6105 S.Diag(NewDecl->getLocation(),
6106 diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
6107 << NewDecl << OldImportAttr;
6108 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6109 S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute);
6110 OldDecl->dropAttr<DLLImportAttr>();
6111 NewDecl->dropAttr<DLLImportAttr>();
6113 } else if (IsInline && OldImportAttr && !IsMicrosoft) {
6114 // In MinGW, seeing a function declared inline drops the dllimport
6116 OldDecl->dropAttr<DLLImportAttr>();
6117 NewDecl->dropAttr<DLLImportAttr>();
6118 S.Diag(NewDecl->getLocation(),
6119 diag::warn_dllimport_dropped_from_inline_function)
6120 << NewDecl << OldImportAttr;
6123 // A specialization of a class template member function is processed here
6124 // since it's a redeclaration. If the parent class is dllexport, the
6125 // specialization inherits that attribute. This doesn't happen automatically
6126 // since the parent class isn't instantiated until later.
6127 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDecl)) {
6128 if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
6129 !NewImportAttr && !NewExportAttr) {
6130 if (const DLLExportAttr *ParentExportAttr =
6131 MD->getParent()->getAttr<DLLExportAttr>()) {
6132 DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context);
6133 NewAttr->setInherited(true);
6134 NewDecl->addAttr(NewAttr);
6140 /// Given that we are within the definition of the given function,
6141 /// will that definition behave like C99's 'inline', where the
6142 /// definition is discarded except for optimization purposes?
6143 static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) {
6144 // Try to avoid calling GetGVALinkageForFunction.
6146 // All cases of this require the 'inline' keyword.
6147 if (!FD->isInlined()) return false;
6149 // This is only possible in C++ with the gnu_inline attribute.
6150 if (S.getLangOpts().CPlusPlus && !FD->hasAttr<GNUInlineAttr>())
6153 // Okay, go ahead and call the relatively-more-expensive function.
6154 return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally;
6157 /// Determine whether a variable is extern "C" prior to attaching
6158 /// an initializer. We can't just call isExternC() here, because that
6159 /// will also compute and cache whether the declaration is externally
6160 /// visible, which might change when we attach the initializer.
6162 /// This can only be used if the declaration is known to not be a
6163 /// redeclaration of an internal linkage declaration.
6169 /// Attaching the initializer here makes this declaration not externally
6170 /// visible, because its type has internal linkage.
6172 /// FIXME: This is a hack.
6173 template<typename T>
6174 static bool isIncompleteDeclExternC(Sema &S, const T *D) {
6175 if (S.getLangOpts().CPlusPlus) {
6176 // In C++, the overloadable attribute negates the effects of extern "C".
6177 if (!D->isInExternCContext() || D->template hasAttr<OverloadableAttr>())
6180 // So do CUDA's host/device attributes.
6181 if (S.getLangOpts().CUDA && (D->template hasAttr<CUDADeviceAttr>() ||
6182 D->template hasAttr<CUDAHostAttr>()))
6185 return D->isExternC();
6188 static bool shouldConsiderLinkage(const VarDecl *VD) {
6189 const DeclContext *DC = VD->getDeclContext()->getRedeclContext();
6190 if (DC->isFunctionOrMethod() || isa<OMPDeclareReductionDecl>(DC))
6191 return VD->hasExternalStorage();
6192 if (DC->isFileContext())
6196 llvm_unreachable("Unexpected context");
6199 static bool shouldConsiderLinkage(const FunctionDecl *FD) {
6200 const DeclContext *DC = FD->getDeclContext()->getRedeclContext();
6201 if (DC->isFileContext() || DC->isFunctionOrMethod() ||
6202 isa<OMPDeclareReductionDecl>(DC))
6206 llvm_unreachable("Unexpected context");
6209 static bool hasParsedAttr(Scope *S, const Declarator &PD,
6210 ParsedAttr::Kind Kind) {
6211 // Check decl attributes on the DeclSpec.
6212 if (PD.getDeclSpec().getAttributes().hasAttribute(Kind))
6215 // Walk the declarator structure, checking decl attributes that were in a type
6216 // position to the decl itself.
6217 for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) {
6218 if (PD.getTypeObject(I).getAttrs().hasAttribute(Kind))
6222 // Finally, check attributes on the decl itself.
6223 return PD.getAttributes().hasAttribute(Kind);
6226 /// Adjust the \c DeclContext for a function or variable that might be a
6227 /// function-local external declaration.
6228 bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
6229 if (!DC->isFunctionOrMethod())
6232 // If this is a local extern function or variable declared within a function
6233 // template, don't add it into the enclosing namespace scope until it is
6234 // instantiated; it might have a dependent type right now.
6235 if (DC->isDependentContext())
6238 // C++11 [basic.link]p7:
6239 // When a block scope declaration of an entity with linkage is not found to
6240 // refer to some other declaration, then that entity is a member of the
6241 // innermost enclosing namespace.
6243 // Per C++11 [namespace.def]p6, the innermost enclosing namespace is a
6244 // semantically-enclosing namespace, not a lexically-enclosing one.
6245 while (!DC->isFileContext() && !isa<LinkageSpecDecl>(DC))
6246 DC = DC->getParent();
6250 /// Returns true if given declaration has external C language linkage.
6251 static bool isDeclExternC(const Decl *D) {
6252 if (const auto *FD = dyn_cast<FunctionDecl>(D))
6253 return FD->isExternC();
6254 if (const auto *VD = dyn_cast<VarDecl>(D))
6255 return VD->isExternC();
6257 llvm_unreachable("Unknown type of decl!");
6260 NamedDecl *Sema::ActOnVariableDeclarator(
6261 Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
6262 LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
6263 bool &AddToScope, ArrayRef<BindingDecl *> Bindings) {
6264 QualType R = TInfo->getType();
6265 DeclarationName Name = GetNameForDeclarator(D).getName();
6267 IdentifierInfo *II = Name.getAsIdentifierInfo();
6269 if (D.isDecompositionDeclarator()) {
6270 // Take the name of the first declarator as our name for diagnostic
6272 auto &Decomp = D.getDecompositionDeclarator();
6273 if (!Decomp.bindings().empty()) {
6274 II = Decomp.bindings()[0].Name;
6278 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) << Name;
6282 if (getLangOpts().OpenCL) {
6283 // OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
6284 // OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
6286 if (R->isImageType() || R->isPipeType()) {
6287 Diag(D.getIdentifierLoc(),
6288 diag::err_opencl_type_can_only_be_used_as_function_parameter)
6294 // OpenCL v1.2 s6.9.r:
6295 // The event type cannot be used to declare a program scope variable.
6296 // OpenCL v2.0 s6.9.q:
6297 // The clk_event_t and reserve_id_t types cannot be declared in program scope.
6298 if (NULL == S->getParent()) {
6299 if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) {
6300 Diag(D.getIdentifierLoc(),
6301 diag::err_invalid_type_for_program_scope_var) << R;
6307 // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
6309 while (NR->isPointerType()) {
6310 if (NR->isFunctionPointerType()) {
6311 Diag(D.getIdentifierLoc(), diag::err_opencl_function_pointer);
6315 NR = NR->getPointeeType();
6318 if (!getOpenCLOptions().isEnabled("cl_khr_fp16")) {
6319 // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and
6320 // half array type (unless the cl_khr_fp16 extension is enabled).
6321 if (Context.getBaseElementType(R)->isHalfType()) {
6322 Diag(D.getIdentifierLoc(), diag::err_opencl_half_declaration) << R;
6327 if (R->isSamplerT()) {
6328 // OpenCL v1.2 s6.9.b p4:
6329 // The sampler type cannot be used with the __local and __global address
6330 // space qualifiers.
6331 if (R.getAddressSpace() == LangAS::opencl_local ||
6332 R.getAddressSpace() == LangAS::opencl_global) {
6333 Diag(D.getIdentifierLoc(), diag::err_wrong_sampler_addressspace);
6336 // OpenCL v1.2 s6.12.14.1:
6337 // A global sampler must be declared with either the constant address
6338 // space qualifier or with the const qualifier.
6339 if (DC->isTranslationUnit() &&
6340 !(R.getAddressSpace() == LangAS::opencl_constant ||
6341 R.isConstQualified())) {
6342 Diag(D.getIdentifierLoc(), diag::err_opencl_nonconst_global_sampler);
6347 // OpenCL v1.2 s6.9.r:
6348 // The event type cannot be used with the __local, __constant and __global
6349 // address space qualifiers.
6350 if (R->isEventT()) {
6351 if (R.getAddressSpace() != LangAS::opencl_private) {
6352 Diag(D.getBeginLoc(), diag::err_event_t_addr_space_qual);
6357 // OpenCL C++ 1.0 s2.9: the thread_local storage qualifier is not
6358 // supported. OpenCL C does not support thread_local either, and
6359 // also reject all other thread storage class specifiers.
6360 DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec();
6361 if (TSC != TSCS_unspecified) {
6362 bool IsCXX = getLangOpts().OpenCLCPlusPlus;
6363 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6364 diag::err_opencl_unknown_type_specifier)
6365 << IsCXX << getLangOpts().getOpenCLVersionTuple().getAsString()
6366 << DeclSpec::getSpecifierName(TSC) << 1;
6372 DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec();
6373 StorageClass SC = StorageClassSpecToVarDeclStorageClass(D.getDeclSpec());
6375 // dllimport globals without explicit storage class are treated as extern. We
6376 // have to change the storage class this early to get the right DeclContext.
6377 if (SC == SC_None && !DC->isRecord() &&
6378 hasParsedAttr(S, D, ParsedAttr::AT_DLLImport) &&
6379 !hasParsedAttr(S, D, ParsedAttr::AT_DLLExport))
6382 DeclContext *OriginalDC = DC;
6383 bool IsLocalExternDecl = SC == SC_Extern &&
6384 adjustContextForLocalExternDecl(DC);
6386 if (SCSpec == DeclSpec::SCS_mutable) {
6387 // mutable can only appear on non-static class members, so it's always
6389 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
6394 if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register &&
6395 !D.getAsmLabel() && !getSourceManager().isInSystemMacro(
6396 D.getDeclSpec().getStorageClassSpecLoc())) {
6397 // In C++11, the 'register' storage class specifier is deprecated.
6398 // Suppress the warning in system macros, it's used in macros in some
6399 // popular C system headers, such as in glibc's htonl() macro.
6400 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6401 getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
6402 : diag::warn_deprecated_register)
6403 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6406 DiagnoseFunctionSpecifiers(D.getDeclSpec());
6408 if (!DC->isRecord() && S->getFnParent() == nullptr) {
6409 // C99 6.9p2: The storage-class specifiers auto and register shall not
6410 // appear in the declaration specifiers in an external declaration.
6411 // Global Register+Asm is a GNU extension we support.
6412 if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) {
6413 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope);
6418 bool IsMemberSpecialization = false;
6419 bool IsVariableTemplateSpecialization = false;
6420 bool IsPartialSpecialization = false;
6421 bool IsVariableTemplate = false;
6422 VarDecl *NewVD = nullptr;
6423 VarTemplateDecl *NewTemplate = nullptr;
6424 TemplateParameterList *TemplateParams = nullptr;
6425 if (!getLangOpts().CPlusPlus) {
6426 NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(), D.getIdentifierLoc(),
6429 if (R->getContainedDeducedType())
6430 ParsingInitForAutoVars.insert(NewVD);
6432 if (D.isInvalidType())
6433 NewVD->setInvalidDecl();
6435 bool Invalid = false;
6437 if (DC->isRecord() && !CurContext->isRecord()) {
6438 // This is an out-of-line definition of a static data member.
6443 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6444 diag::err_static_out_of_line)
6445 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6450 // [dcl.stc] p2: The auto or register specifiers shall be applied only
6451 // to names of variables declared in a block or to function parameters.
6452 // [dcl.stc] p6: The extern specifier cannot be used in the declaration
6455 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6456 diag::err_storage_class_for_static_member)
6457 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6459 case SC_PrivateExtern:
6460 llvm_unreachable("C storage class in c++!");
6464 if (SC == SC_Static && CurContext->isRecord()) {
6465 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) {
6466 if (RD->isLocalClass())
6467 Diag(D.getIdentifierLoc(),
6468 diag::err_static_data_member_not_allowed_in_local_class)
6469 << Name << RD->getDeclName();
6471 // C++98 [class.union]p1: If a union contains a static data member,
6472 // the program is ill-formed. C++11 drops this restriction.
6474 Diag(D.getIdentifierLoc(),
6475 getLangOpts().CPlusPlus11
6476 ? diag::warn_cxx98_compat_static_data_member_in_union
6477 : diag::ext_static_data_member_in_union) << Name;
6478 // We conservatively disallow static data members in anonymous structs.
6479 else if (!RD->getDeclName())
6480 Diag(D.getIdentifierLoc(),
6481 diag::err_static_data_member_not_allowed_in_anon_struct)
6482 << Name << RD->isUnion();
6486 // Match up the template parameter lists with the scope specifier, then
6487 // determine whether we have a template or a template specialization.
6488 TemplateParams = MatchTemplateParametersToScopeSpecifier(
6489 D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
6490 D.getCXXScopeSpec(),
6491 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
6492 ? D.getName().TemplateId
6495 /*never a friend*/ false, IsMemberSpecialization, Invalid);
6497 if (TemplateParams) {
6498 if (!TemplateParams->size() &&
6499 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
6500 // There is an extraneous 'template<>' for this variable. Complain
6501 // about it, but allow the declaration of the variable.
6502 Diag(TemplateParams->getTemplateLoc(),
6503 diag::err_template_variable_noparams)
6505 << SourceRange(TemplateParams->getTemplateLoc(),
6506 TemplateParams->getRAngleLoc());
6507 TemplateParams = nullptr;
6509 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
6510 // This is an explicit specialization or a partial specialization.
6511 // FIXME: Check that we can declare a specialization here.
6512 IsVariableTemplateSpecialization = true;
6513 IsPartialSpecialization = TemplateParams->size() > 0;
6514 } else { // if (TemplateParams->size() > 0)
6515 // This is a template declaration.
6516 IsVariableTemplate = true;
6518 // Check that we can declare a template here.
6519 if (CheckTemplateDeclScope(S, TemplateParams))
6522 // Only C++1y supports variable templates (N3651).
6523 Diag(D.getIdentifierLoc(),
6524 getLangOpts().CPlusPlus14
6525 ? diag::warn_cxx11_compat_variable_template
6526 : diag::ext_variable_template);
6531 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) &&
6532 "should have a 'template<>' for this decl");
6535 if (IsVariableTemplateSpecialization) {
6536 SourceLocation TemplateKWLoc =
6537 TemplateParamLists.size() > 0
6538 ? TemplateParamLists[0]->getTemplateLoc()
6540 DeclResult Res = ActOnVarTemplateSpecialization(
6541 S, D, TInfo, TemplateKWLoc, TemplateParams, SC,
6542 IsPartialSpecialization);
6543 if (Res.isInvalid())
6545 NewVD = cast<VarDecl>(Res.get());
6547 } else if (D.isDecompositionDeclarator()) {
6548 NewVD = DecompositionDecl::Create(Context, DC, D.getBeginLoc(),
6549 D.getIdentifierLoc(), R, TInfo, SC,
6552 NewVD = VarDecl::Create(Context, DC, D.getBeginLoc(),
6553 D.getIdentifierLoc(), II, R, TInfo, SC);
6555 // If this is supposed to be a variable template, create it as such.
6556 if (IsVariableTemplate) {
6558 VarTemplateDecl::Create(Context, DC, D.getIdentifierLoc(), Name,
6559 TemplateParams, NewVD);
6560 NewVD->setDescribedVarTemplate(NewTemplate);
6563 // If this decl has an auto type in need of deduction, make a note of the
6564 // Decl so we can diagnose uses of it in its own initializer.
6565 if (R->getContainedDeducedType())
6566 ParsingInitForAutoVars.insert(NewVD);
6568 if (D.isInvalidType() || Invalid) {
6569 NewVD->setInvalidDecl();
6571 NewTemplate->setInvalidDecl();
6574 SetNestedNameSpecifier(*this, NewVD, D);
6576 // If we have any template parameter lists that don't directly belong to
6577 // the variable (matching the scope specifier), store them.
6578 unsigned VDTemplateParamLists = TemplateParams ? 1 : 0;
6579 if (TemplateParamLists.size() > VDTemplateParamLists)
6580 NewVD->setTemplateParameterListsInfo(
6581 Context, TemplateParamLists.drop_back(VDTemplateParamLists));
6583 if (D.getDeclSpec().isConstexprSpecified()) {
6584 NewVD->setConstexpr(true);
6585 // C++1z [dcl.spec.constexpr]p1:
6586 // A static data member declared with the constexpr specifier is
6587 // implicitly an inline variable.
6588 if (NewVD->isStaticDataMember() && getLangOpts().CPlusPlus17)
6589 NewVD->setImplicitlyInline();
6593 if (D.getDeclSpec().isInlineSpecified()) {
6594 if (!getLangOpts().CPlusPlus) {
6595 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
6597 } else if (CurContext->isFunctionOrMethod()) {
6598 // 'inline' is not allowed on block scope variable declaration.
6599 Diag(D.getDeclSpec().getInlineSpecLoc(),
6600 diag::err_inline_declaration_block_scope) << Name
6601 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
6603 Diag(D.getDeclSpec().getInlineSpecLoc(),
6604 getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_inline_variable
6605 : diag::ext_inline_variable);
6606 NewVD->setInlineSpecified();
6610 // Set the lexical context. If the declarator has a C++ scope specifier, the
6611 // lexical context will be different from the semantic context.
6612 NewVD->setLexicalDeclContext(CurContext);
6614 NewTemplate->setLexicalDeclContext(CurContext);
6616 if (IsLocalExternDecl) {
6617 if (D.isDecompositionDeclarator())
6618 for (auto *B : Bindings)
6619 B->setLocalExternDecl();
6621 NewVD->setLocalExternDecl();
6624 bool EmitTLSUnsupportedError = false;
6625 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) {
6626 // C++11 [dcl.stc]p4:
6627 // When thread_local is applied to a variable of block scope the
6628 // storage-class-specifier static is implied if it does not appear
6630 // Core issue: 'static' is not implied if the variable is declared
6632 if (NewVD->hasLocalStorage() &&
6633 (SCSpec != DeclSpec::SCS_unspecified ||
6634 TSCS != DeclSpec::TSCS_thread_local ||
6635 !DC->isFunctionOrMethod()))
6636 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6637 diag::err_thread_non_global)
6638 << DeclSpec::getSpecifierName(TSCS);
6639 else if (!Context.getTargetInfo().isTLSSupported()) {
6640 if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) {
6641 // Postpone error emission until we've collected attributes required to
6642 // figure out whether it's a host or device variable and whether the
6643 // error should be ignored.
6644 EmitTLSUnsupportedError = true;
6645 // We still need to mark the variable as TLS so it shows up in AST with
6646 // proper storage class for other tools to use even if we're not going
6647 // to emit any code for it.
6648 NewVD->setTSCSpec(TSCS);
6650 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6651 diag::err_thread_unsupported);
6653 NewVD->setTSCSpec(TSCS);
6657 // An inline definition of a function with external linkage shall
6658 // not contain a definition of a modifiable object with static or
6659 // thread storage duration...
6660 // We only apply this when the function is required to be defined
6661 // elsewhere, i.e. when the function is not 'extern inline'. Note
6662 // that a local variable with thread storage duration still has to
6663 // be marked 'static'. Also note that it's possible to get these
6664 // semantics in C++ using __attribute__((gnu_inline)).
6665 if (SC == SC_Static && S->getFnParent() != nullptr &&
6666 !NewVD->getType().isConstQualified()) {
6667 FunctionDecl *CurFD = getCurFunctionDecl();
6668 if (CurFD && isFunctionDefinitionDiscarded(*this, CurFD)) {
6669 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6670 diag::warn_static_local_in_extern_inline);
6671 MaybeSuggestAddingStaticToDecl(CurFD);
6675 if (D.getDeclSpec().isModulePrivateSpecified()) {
6676 if (IsVariableTemplateSpecialization)
6677 Diag(NewVD->getLocation(), diag::err_module_private_specialization)
6678 << (IsPartialSpecialization ? 1 : 0)
6679 << FixItHint::CreateRemoval(
6680 D.getDeclSpec().getModulePrivateSpecLoc());
6681 else if (IsMemberSpecialization)
6682 Diag(NewVD->getLocation(), diag::err_module_private_specialization)
6684 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
6685 else if (NewVD->hasLocalStorage())
6686 Diag(NewVD->getLocation(), diag::err_module_private_local)
6687 << 0 << NewVD->getDeclName()
6688 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
6689 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
6691 NewVD->setModulePrivate();
6693 NewTemplate->setModulePrivate();
6694 for (auto *B : Bindings)
6695 B->setModulePrivate();
6699 // Handle attributes prior to checking for duplicates in MergeVarDecl
6700 ProcessDeclAttributes(S, NewVD, D);
6702 if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) {
6703 if (EmitTLSUnsupportedError &&
6704 ((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) ||
6705 (getLangOpts().OpenMPIsDevice &&
6706 NewVD->hasAttr<OMPDeclareTargetDeclAttr>())))
6707 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6708 diag::err_thread_unsupported);
6709 // CUDA B.2.5: "__shared__ and __constant__ variables have implied static
6710 // storage [duration]."
6711 if (SC == SC_None && S->getFnParent() != nullptr &&
6712 (NewVD->hasAttr<CUDASharedAttr>() ||
6713 NewVD->hasAttr<CUDAConstantAttr>())) {
6714 NewVD->setStorageClass(SC_Static);
6718 // Ensure that dllimport globals without explicit storage class are treated as
6719 // extern. The storage class is set above using parsed attributes. Now we can
6720 // check the VarDecl itself.
6721 assert(!NewVD->hasAttr<DLLImportAttr>() ||
6722 NewVD->getAttr<DLLImportAttr>()->isInherited() ||
6723 NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None);
6725 // In auto-retain/release, infer strong retension for variables of
6727 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewVD))
6728 NewVD->setInvalidDecl();
6730 // Handle GNU asm-label extension (encoded as an attribute).
6731 if (Expr *E = (Expr*)D.getAsmLabel()) {
6732 // The parser guarantees this is a string.
6733 StringLiteral *SE = cast<StringLiteral>(E);
6734 StringRef Label = SE->getString();
6735 if (S->getFnParent() != nullptr) {
6739 Diag(E->getExprLoc(), diag::warn_asm_label_on_auto_decl) << Label;
6742 // Local Named register
6743 if (!Context.getTargetInfo().isValidGCCRegisterName(Label) &&
6744 DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl()))
6745 Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
6749 case SC_PrivateExtern:
6752 } else if (SC == SC_Register) {
6753 // Global Named register
6754 if (DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) {
6755 const auto &TI = Context.getTargetInfo();
6756 bool HasSizeMismatch;
6758 if (!TI.isValidGCCRegisterName(Label))
6759 Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
6760 else if (!TI.validateGlobalRegisterVariable(Label,
6761 Context.getTypeSize(R),
6763 Diag(E->getExprLoc(), diag::err_asm_invalid_global_var_reg) << Label;
6764 else if (HasSizeMismatch)
6765 Diag(E->getExprLoc(), diag::err_asm_register_size_mismatch) << Label;
6768 if (!R->isIntegralType(Context) && !R->isPointerType()) {
6769 Diag(D.getBeginLoc(), diag::err_asm_bad_register_type);
6770 NewVD->setInvalidDecl(true);
6774 NewVD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0),
6775 Context, Label, 0));
6776 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
6777 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
6778 ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
6779 if (I != ExtnameUndeclaredIdentifiers.end()) {
6780 if (isDeclExternC(NewVD)) {
6781 NewVD->addAttr(I->second);
6782 ExtnameUndeclaredIdentifiers.erase(I);
6784 Diag(NewVD->getLocation(), diag::warn_redefine_extname_not_applied)
6785 << /*Variable*/1 << NewVD;
6789 // Find the shadowed declaration before filtering for scope.
6790 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
6791 ? getShadowedDeclaration(NewVD, Previous)
6794 // Don't consider existing declarations that are in a different
6795 // scope and are out-of-semantic-context declarations (if the new
6796 // declaration has linkage).
6797 FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewVD),
6798 D.getCXXScopeSpec().isNotEmpty() ||
6799 IsMemberSpecialization ||
6800 IsVariableTemplateSpecialization);
6802 // Check whether the previous declaration is in the same block scope. This
6803 // affects whether we merge types with it, per C++11 [dcl.array]p3.
6804 if (getLangOpts().CPlusPlus &&
6805 NewVD->isLocalVarDecl() && NewVD->hasExternalStorage())
6806 NewVD->setPreviousDeclInSameBlockScope(
6807 Previous.isSingleResult() && !Previous.isShadowed() &&
6808 isDeclInScope(Previous.getFoundDecl(), OriginalDC, S, false));
6810 if (!getLangOpts().CPlusPlus) {
6811 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
6813 // If this is an explicit specialization of a static data member, check it.
6814 if (IsMemberSpecialization && !NewVD->isInvalidDecl() &&
6815 CheckMemberSpecialization(NewVD, Previous))
6816 NewVD->setInvalidDecl();
6818 // Merge the decl with the existing one if appropriate.
6819 if (!Previous.empty()) {
6820 if (Previous.isSingleResult() &&
6821 isa<FieldDecl>(Previous.getFoundDecl()) &&
6822 D.getCXXScopeSpec().isSet()) {
6823 // The user tried to define a non-static data member
6824 // out-of-line (C++ [dcl.meaning]p1).
6825 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line)
6826 << D.getCXXScopeSpec().getRange();
6828 NewVD->setInvalidDecl();
6830 } else if (D.getCXXScopeSpec().isSet()) {
6831 // No previous declaration in the qualifying scope.
6832 Diag(D.getIdentifierLoc(), diag::err_no_member)
6833 << Name << computeDeclContext(D.getCXXScopeSpec(), true)
6834 << D.getCXXScopeSpec().getRange();
6835 NewVD->setInvalidDecl();
6838 if (!IsVariableTemplateSpecialization)
6839 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
6842 VarTemplateDecl *PrevVarTemplate =
6843 NewVD->getPreviousDecl()
6844 ? NewVD->getPreviousDecl()->getDescribedVarTemplate()
6847 // Check the template parameter list of this declaration, possibly
6848 // merging in the template parameter list from the previous variable
6849 // template declaration.
6850 if (CheckTemplateParameterList(
6852 PrevVarTemplate ? PrevVarTemplate->getTemplateParameters()
6854 (D.getCXXScopeSpec().isSet() && DC && DC->isRecord() &&
6855 DC->isDependentContext())
6856 ? TPC_ClassTemplateMember
6858 NewVD->setInvalidDecl();
6860 // If we are providing an explicit specialization of a static variable
6861 // template, make a note of that.
6862 if (PrevVarTemplate &&
6863 PrevVarTemplate->getInstantiatedFromMemberTemplate())
6864 PrevVarTemplate->setMemberSpecialization();
6868 // Diagnose shadowed variables iff this isn't a redeclaration.
6869 if (ShadowedDecl && !D.isRedeclaration())
6870 CheckShadow(NewVD, ShadowedDecl, Previous);
6872 ProcessPragmaWeak(S, NewVD);
6874 // If this is the first declaration of an extern C variable, update
6875 // the map of such variables.
6876 if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() &&
6877 isIncompleteDeclExternC(*this, NewVD))
6878 RegisterLocallyScopedExternCDecl(NewVD, S);
6880 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
6881 Decl *ManglingContextDecl;
6882 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
6883 NewVD->getDeclContext(), ManglingContextDecl)) {
6884 Context.setManglingNumber(
6885 NewVD, MCtx->getManglingNumber(
6886 NewVD, getMSManglingNumber(getLangOpts(), S)));
6887 Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
6891 // Special handling of variable named 'main'.
6892 if (Name.getAsIdentifierInfo() && Name.getAsIdentifierInfo()->isStr("main") &&
6893 NewVD->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
6894 !getLangOpts().Freestanding && !NewVD->getDescribedVarTemplate()) {
6896 // C++ [basic.start.main]p3
6897 // A program that declares a variable main at global scope is ill-formed.
6898 if (getLangOpts().CPlusPlus)
6899 Diag(D.getBeginLoc(), diag::err_main_global_variable);
6901 // In C, and external-linkage variable named main results in undefined
6903 else if (NewVD->hasExternalFormalLinkage())
6904 Diag(D.getBeginLoc(), diag::warn_main_redefined);
6907 if (D.isRedeclaration() && !Previous.empty()) {
6908 NamedDecl *Prev = Previous.getRepresentativeDecl();
6909 checkDLLAttributeRedeclaration(*this, Prev, NewVD, IsMemberSpecialization,
6910 D.isFunctionDefinition());
6914 if (NewVD->isInvalidDecl())
6915 NewTemplate->setInvalidDecl();
6916 ActOnDocumentableDecl(NewTemplate);
6920 if (IsMemberSpecialization && !NewVD->isInvalidDecl())
6921 CompleteMemberSpecialization(NewVD, Previous);
6926 /// Enum describing the %select options in diag::warn_decl_shadow.
6927 enum ShadowedDeclKind {
6936 /// Determine what kind of declaration we're shadowing.
6937 static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
6938 const DeclContext *OldDC) {
6939 if (isa<TypeAliasDecl>(ShadowedDecl))
6941 else if (isa<TypedefDecl>(ShadowedDecl))
6943 else if (isa<RecordDecl>(OldDC))
6944 return isa<FieldDecl>(ShadowedDecl) ? SDK_Field : SDK_StaticMember;
6946 return OldDC->isFileContext() ? SDK_Global : SDK_Local;
6949 /// Return the location of the capture if the given lambda captures the given
6950 /// variable \p VD, or an invalid source location otherwise.
6951 static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI,
6952 const VarDecl *VD) {
6953 for (const Capture &Capture : LSI->Captures) {
6954 if (Capture.isVariableCapture() && Capture.getVariable() == VD)
6955 return Capture.getLocation();
6957 return SourceLocation();
6960 static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
6961 const LookupResult &R) {
6962 // Only diagnose if we're shadowing an unambiguous field or variable.
6963 if (R.getResultKind() != LookupResult::Found)
6966 // Return false if warning is ignored.
6967 return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc());
6970 /// Return the declaration shadowed by the given variable \p D, or null
6971 /// if it doesn't shadow any declaration or shadowing warnings are disabled.
6972 NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
6973 const LookupResult &R) {
6974 if (!shouldWarnIfShadowedDecl(Diags, R))
6977 // Don't diagnose declarations at file scope.
6978 if (D->hasGlobalStorage())
6981 NamedDecl *ShadowedDecl = R.getFoundDecl();
6982 return isa<VarDecl>(ShadowedDecl) || isa<FieldDecl>(ShadowedDecl)
6987 /// Return the declaration shadowed by the given typedef \p D, or null
6988 /// if it doesn't shadow any declaration or shadowing warnings are disabled.
6989 NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
6990 const LookupResult &R) {
6991 // Don't warn if typedef declaration is part of a class
6992 if (D->getDeclContext()->isRecord())
6995 if (!shouldWarnIfShadowedDecl(Diags, R))
6998 NamedDecl *ShadowedDecl = R.getFoundDecl();
6999 return isa<TypedefNameDecl>(ShadowedDecl) ? ShadowedDecl : nullptr;
7002 /// Diagnose variable or built-in function shadowing. Implements
7005 /// This method is called whenever a VarDecl is added to a "useful"
7008 /// \param ShadowedDecl the declaration that is shadowed by the given variable
7009 /// \param R the lookup of the name
7011 void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
7012 const LookupResult &R) {
7013 DeclContext *NewDC = D->getDeclContext();
7015 if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) {
7016 // Fields are not shadowed by variables in C++ static methods.
7017 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDC))
7021 // Fields shadowed by constructor parameters are a special case. Usually
7022 // the constructor initializes the field with the parameter.
7023 if (isa<CXXConstructorDecl>(NewDC))
7024 if (const auto PVD = dyn_cast<ParmVarDecl>(D)) {
7025 // Remember that this was shadowed so we can either warn about its
7026 // modification or its existence depending on warning settings.
7027 ShadowingDecls.insert({PVD->getCanonicalDecl(), FD});
7032 if (VarDecl *shadowedVar = dyn_cast<VarDecl>(ShadowedDecl))
7033 if (shadowedVar->isExternC()) {
7034 // For shadowing external vars, make sure that we point to the global
7035 // declaration, not a locally scoped extern declaration.
7036 for (auto I : shadowedVar->redecls())
7037 if (I->isFileVarDecl()) {
7043 DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();
7045 unsigned WarningDiag = diag::warn_decl_shadow;
7046 SourceLocation CaptureLoc;
7047 if (isa<VarDecl>(D) && isa<VarDecl>(ShadowedDecl) && NewDC &&
7048 isa<CXXMethodDecl>(NewDC)) {
7049 if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
7050 if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
7051 if (RD->getLambdaCaptureDefault() == LCD_None) {
7052 // Try to avoid warnings for lambdas with an explicit capture list.
7053 const auto *LSI = cast<LambdaScopeInfo>(getCurFunction());
7054 // Warn only when the lambda captures the shadowed decl explicitly.
7055 CaptureLoc = getCaptureLocation(LSI, cast<VarDecl>(ShadowedDecl));
7056 if (CaptureLoc.isInvalid())
7057 WarningDiag = diag::warn_decl_shadow_uncaptured_local;
7059 // Remember that this was shadowed so we can avoid the warning if the
7060 // shadowed decl isn't captured and the warning settings allow it.
7061 cast<LambdaScopeInfo>(getCurFunction())
7062 ->ShadowingDecls.push_back(
7063 {cast<VarDecl>(D), cast<VarDecl>(ShadowedDecl)});
7068 if (cast<VarDecl>(ShadowedDecl)->hasLocalStorage()) {
7069 // A variable can't shadow a local variable in an enclosing scope, if
7070 // they are separated by a non-capturing declaration context.
7071 for (DeclContext *ParentDC = NewDC;
7072 ParentDC && !ParentDC->Equals(OldDC);
7073 ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) {
7074 // Only block literals, captured statements, and lambda expressions
7075 // can capture; other scopes don't.
7076 if (!isa<BlockDecl>(ParentDC) && !isa<CapturedDecl>(ParentDC) &&
7077 !isLambdaCallOperator(ParentDC)) {
7085 // Only warn about certain kinds of shadowing for class members.
7086 if (NewDC && NewDC->isRecord()) {
7087 // In particular, don't warn about shadowing non-class members.
7088 if (!OldDC->isRecord())
7091 // TODO: should we warn about static data members shadowing
7092 // static data members from base classes?
7094 // TODO: don't diagnose for inaccessible shadowed members.
7095 // This is hard to do perfectly because we might friend the
7096 // shadowing context, but that's just a false negative.
7100 DeclarationName Name = R.getLookupName();
7102 // Emit warning and note.
7103 if (getSourceManager().isInSystemMacro(R.getNameLoc()))
7105 ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC);
7106 Diag(R.getNameLoc(), WarningDiag) << Name << Kind << OldDC;
7107 if (!CaptureLoc.isInvalid())
7108 Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
7109 << Name << /*explicitly*/ 1;
7110 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7113 /// Diagnose shadowing for variables shadowed in the lambda record \p LambdaRD
7114 /// when these variables are captured by the lambda.
7115 void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) {
7116 for (const auto &Shadow : LSI->ShadowingDecls) {
7117 const VarDecl *ShadowedDecl = Shadow.ShadowedDecl;
7118 // Try to avoid the warning when the shadowed decl isn't captured.
7119 SourceLocation CaptureLoc = getCaptureLocation(LSI, ShadowedDecl);
7120 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
7121 Diag(Shadow.VD->getLocation(), CaptureLoc.isInvalid()
7122 ? diag::warn_decl_shadow_uncaptured_local
7123 : diag::warn_decl_shadow)
7124 << Shadow.VD->getDeclName()
7125 << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
7126 if (!CaptureLoc.isInvalid())
7127 Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
7128 << Shadow.VD->getDeclName() << /*explicitly*/ 0;
7129 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7133 /// Check -Wshadow without the advantage of a previous lookup.
7134 void Sema::CheckShadow(Scope *S, VarDecl *D) {
7135 if (Diags.isIgnored(diag::warn_decl_shadow, D->getLocation()))
7138 LookupResult R(*this, D->getDeclName(), D->getLocation(),
7139 Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
7141 if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R))
7142 CheckShadow(D, ShadowedDecl, R);
7145 /// Check if 'E', which is an expression that is about to be modified, refers
7146 /// to a constructor parameter that shadows a field.
7147 void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) {
7148 // Quickly ignore expressions that can't be shadowing ctor parameters.
7149 if (!getLangOpts().CPlusPlus || ShadowingDecls.empty())
7151 E = E->IgnoreParenImpCasts();
7152 auto *DRE = dyn_cast<DeclRefExpr>(E);
7155 const NamedDecl *D = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
7156 auto I = ShadowingDecls.find(D);
7157 if (I == ShadowingDecls.end())
7159 const NamedDecl *ShadowedDecl = I->second;
7160 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
7161 Diag(Loc, diag::warn_modifying_shadowing_decl) << D << OldDC;
7162 Diag(D->getLocation(), diag::note_var_declared_here) << D;
7163 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7165 // Avoid issuing multiple warnings about the same decl.
7166 ShadowingDecls.erase(I);
7169 /// Check for conflict between this global or extern "C" declaration and
7170 /// previous global or extern "C" declarations. This is only used in C++.
7171 template<typename T>
7172 static bool checkGlobalOrExternCConflict(
7173 Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) {
7174 assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\"");
7175 NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName());
7177 if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) {
7178 // The common case: this global doesn't conflict with any extern "C"
7184 if (!IsGlobal || isIncompleteDeclExternC(S, ND)) {
7185 // Both the old and new declarations have C language linkage. This is a
7188 Previous.addDecl(Prev);
7192 // This is a global, non-extern "C" declaration, and there is a previous
7193 // non-global extern "C" declaration. Diagnose if this is a variable
7195 if (!isa<VarDecl>(ND))
7198 // The declaration is extern "C". Check for any declaration in the
7199 // translation unit which might conflict.
7201 // We have already performed the lookup into the translation unit.
7203 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7205 if (isa<VarDecl>(*I)) {
7211 DeclContext::lookup_result R =
7212 S.Context.getTranslationUnitDecl()->lookup(ND->getDeclName());
7213 for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end();
7215 if (isa<VarDecl>(*I)) {
7219 // FIXME: If we have any other entity with this name in global scope,
7220 // the declaration is ill-formed, but that is a defect: it breaks the
7221 // 'stat' hack, for instance. Only variables can have mangled name
7222 // clashes with extern "C" declarations, so only they deserve a
7231 // Use the first declaration's location to ensure we point at something which
7232 // is lexically inside an extern "C" linkage-spec.
7233 assert(Prev && "should have found a previous declaration to diagnose");
7234 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Prev))
7235 Prev = FD->getFirstDecl();
7237 Prev = cast<VarDecl>(Prev)->getFirstDecl();
7239 S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict)
7241 S.Diag(Prev->getLocation(), diag::note_extern_c_global_conflict)
7246 /// Apply special rules for handling extern "C" declarations. Returns \c true
7247 /// if we have found that this is a redeclaration of some prior entity.
7249 /// Per C++ [dcl.link]p6:
7250 /// Two declarations [for a function or variable] with C language linkage
7251 /// with the same name that appear in different scopes refer to the same
7252 /// [entity]. An entity with C language linkage shall not be declared with
7253 /// the same name as an entity in global scope.
7254 template<typename T>
7255 static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND,
7256 LookupResult &Previous) {
7257 if (!S.getLangOpts().CPlusPlus) {
7258 // In C, when declaring a global variable, look for a corresponding 'extern'
7259 // variable declared in function scope. We don't need this in C++, because
7260 // we find local extern decls in the surrounding file-scope DeclContext.
7261 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
7262 if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName())) {
7264 Previous.addDecl(Prev);
7271 // A declaration in the translation unit can conflict with an extern "C"
7273 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit())
7274 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous);
7276 // An extern "C" declaration can conflict with a declaration in the
7277 // translation unit or can be a redeclaration of an extern "C" declaration
7278 // in another scope.
7279 if (isIncompleteDeclExternC(S,ND))
7280 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous);
7282 // Neither global nor extern "C": nothing to do.
7286 void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
7287 // If the decl is already known invalid, don't check it.
7288 if (NewVD->isInvalidDecl())
7291 QualType T = NewVD->getType();
7293 // Defer checking an 'auto' type until its initializer is attached.
7294 if (T->isUndeducedType())
7297 if (NewVD->hasAttrs())
7298 CheckAlignasUnderalignment(NewVD);
7300 if (T->isObjCObjectType()) {
7301 Diag(NewVD->getLocation(), diag::err_statically_allocated_object)
7302 << FixItHint::CreateInsertion(NewVD->getLocation(), "*");
7303 T = Context.getObjCObjectPointerType(T);
7307 // Emit an error if an address space was applied to decl with local storage.
7308 // This includes arrays of objects with address space qualifiers, but not
7309 // automatic variables that point to other address spaces.
7310 // ISO/IEC TR 18037 S5.1.2
7311 if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() &&
7312 T.getAddressSpace() != LangAS::Default) {
7313 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 0;
7314 NewVD->setInvalidDecl();
7318 // OpenCL v1.2 s6.8 - The static qualifier is valid only in program
7320 if (getLangOpts().OpenCLVersion == 120 &&
7321 !getOpenCLOptions().isEnabled("cl_clang_storage_class_specifiers") &&
7322 NewVD->isStaticLocal()) {
7323 Diag(NewVD->getLocation(), diag::err_static_function_scope);
7324 NewVD->setInvalidDecl();
7328 if (getLangOpts().OpenCL) {
7329 // OpenCL v2.0 s6.12.5 - The __block storage type is not supported.
7330 if (NewVD->hasAttr<BlocksAttr>()) {
7331 Diag(NewVD->getLocation(), diag::err_opencl_block_storage_type);
7335 if (T->isBlockPointerType()) {
7336 // OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and
7337 // can't use 'extern' storage class.
7338 if (!T.isConstQualified()) {
7339 Diag(NewVD->getLocation(), diag::err_opencl_invalid_block_declaration)
7341 NewVD->setInvalidDecl();
7344 if (NewVD->hasExternalStorage()) {
7345 Diag(NewVD->getLocation(), diag::err_opencl_extern_block_declaration);
7346 NewVD->setInvalidDecl();
7350 // OpenCL C v1.2 s6.5 - All program scope variables must be declared in the
7351 // __constant address space.
7352 // OpenCL C v2.0 s6.5.1 - Variables defined at program scope and static
7353 // variables inside a function can also be declared in the global
7355 // OpenCL C++ v1.0 s2.5 inherits rule from OpenCL C v2.0 and allows local
7356 // address space additionally.
7357 // FIXME: Add local AS for OpenCL C++.
7358 if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() ||
7359 NewVD->hasExternalStorage()) {
7360 if (!T->isSamplerT() &&
7361 !(T.getAddressSpace() == LangAS::opencl_constant ||
7362 (T.getAddressSpace() == LangAS::opencl_global &&
7363 (getLangOpts().OpenCLVersion == 200 ||
7364 getLangOpts().OpenCLCPlusPlus)))) {
7365 int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1;
7366 if (getLangOpts().OpenCLVersion == 200 || getLangOpts().OpenCLCPlusPlus)
7367 Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
7368 << Scope << "global or constant";
7370 Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
7371 << Scope << "constant";
7372 NewVD->setInvalidDecl();
7376 if (T.getAddressSpace() == LangAS::opencl_global) {
7377 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7378 << 1 /*is any function*/ << "global";
7379 NewVD->setInvalidDecl();
7382 if (T.getAddressSpace() == LangAS::opencl_constant ||
7383 T.getAddressSpace() == LangAS::opencl_local) {
7384 FunctionDecl *FD = getCurFunctionDecl();
7385 // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
7387 if (FD && !FD->hasAttr<OpenCLKernelAttr>()) {
7388 if (T.getAddressSpace() == LangAS::opencl_constant)
7389 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7390 << 0 /*non-kernel only*/ << "constant";
7392 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7393 << 0 /*non-kernel only*/ << "local";
7394 NewVD->setInvalidDecl();
7397 // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
7398 // in the outermost scope of a kernel function.
7399 if (FD && FD->hasAttr<OpenCLKernelAttr>()) {
7400 if (!getCurScope()->isFunctionScope()) {
7401 if (T.getAddressSpace() == LangAS::opencl_constant)
7402 Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
7405 Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
7407 NewVD->setInvalidDecl();
7411 } else if (T.getAddressSpace() != LangAS::opencl_private) {
7412 // Do not allow other address spaces on automatic variable.
7413 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;
7414 NewVD->setInvalidDecl();
7420 if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
7421 && !NewVD->hasAttr<BlocksAttr>()) {
7422 if (getLangOpts().getGC() != LangOptions::NonGC)
7423 Diag(NewVD->getLocation(), diag::warn_gc_attribute_weak_on_local);
7425 assert(!getLangOpts().ObjCAutoRefCount);
7426 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local);
7430 bool isVM = T->isVariablyModifiedType();
7431 if (isVM || NewVD->hasAttr<CleanupAttr>() ||
7432 NewVD->hasAttr<BlocksAttr>())
7433 setFunctionHasBranchProtectedScope();
7435 if ((isVM && NewVD->hasLinkage()) ||
7436 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
7437 bool SizeIsNegative;
7438 llvm::APSInt Oversized;
7439 TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
7440 NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
7442 if (FixedTInfo && T == NewVD->getTypeSourceInfo()->getType())
7443 FixedT = FixedTInfo->getType();
7444 else if (FixedTInfo) {
7445 // Type and type-as-written are canonically different. We need to fix up
7446 // both types separately.
7447 FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
7450 if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
7451 const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
7452 // FIXME: This won't give the correct result for
7454 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();
7456 if (NewVD->isFileVarDecl())
7457 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope)
7459 else if (NewVD->isStaticLocal())
7460 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage)
7463 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
7465 NewVD->setInvalidDecl();
7470 if (NewVD->isFileVarDecl())
7471 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope);
7473 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
7474 NewVD->setInvalidDecl();
7478 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size);
7479 NewVD->setType(FixedT);
7480 NewVD->setTypeSourceInfo(FixedTInfo);
7483 if (T->isVoidType()) {
7484 // C++98 [dcl.stc]p5: The extern specifier can be applied only to the names
7485 // of objects and functions.
7486 if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) {
7487 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
7489 NewVD->setInvalidDecl();
7494 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
7495 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
7496 NewVD->setInvalidDecl();
7500 if (isVM && NewVD->hasAttr<BlocksAttr>()) {
7501 Diag(NewVD->getLocation(), diag::err_block_on_vm);
7502 NewVD->setInvalidDecl();
7506 if (NewVD->isConstexpr() && !T->isDependentType() &&
7507 RequireLiteralType(NewVD->getLocation(), T,
7508 diag::err_constexpr_var_non_literal)) {
7509 NewVD->setInvalidDecl();
7514 /// Perform semantic checking on a newly-created variable
7517 /// This routine performs all of the type-checking required for a
7518 /// variable declaration once it has been built. It is used both to
7519 /// check variables after they have been parsed and their declarators
7520 /// have been translated into a declaration, and to check variables
7521 /// that have been instantiated from a template.
7523 /// Sets NewVD->isInvalidDecl() if an error was encountered.
7525 /// Returns true if the variable declaration is a redeclaration.
7526 bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
7527 CheckVariableDeclarationType(NewVD);
7529 // If the decl is already known invalid, don't check it.
7530 if (NewVD->isInvalidDecl())
7533 // If we did not find anything by this name, look for a non-visible
7534 // extern "C" declaration with the same name.
7535 if (Previous.empty() &&
7536 checkForConflictWithNonVisibleExternC(*this, NewVD, Previous))
7537 Previous.setShadowed();
7539 if (!Previous.empty()) {
7540 MergeVarDecl(NewVD, Previous);
7547 struct FindOverriddenMethod {
7549 CXXMethodDecl *Method;
7551 /// Member lookup function that determines whether a given C++
7552 /// method overrides a method in a base class, to be used with
7553 /// CXXRecordDecl::lookupInBases().
7554 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
7555 RecordDecl *BaseRecord =
7556 Specifier->getType()->getAs<RecordType>()->getDecl();
7558 DeclarationName Name = Method->getDeclName();
7560 // FIXME: Do we care about other names here too?
7561 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
7562 // We really want to find the base class destructor here.
7563 QualType T = S->Context.getTypeDeclType(BaseRecord);
7564 CanQualType CT = S->Context.getCanonicalType(T);
7566 Name = S->Context.DeclarationNames.getCXXDestructorName(CT);
7569 for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty();
7570 Path.Decls = Path.Decls.slice(1)) {
7571 NamedDecl *D = Path.Decls.front();
7572 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
7573 if (MD->isVirtual() && !S->IsOverload(Method, MD, false))
7582 enum OverrideErrorKind { OEK_All, OEK_NonDeleted, OEK_Deleted };
7583 } // end anonymous namespace
7585 /// Report an error regarding overriding, along with any relevant
7586 /// overridden methods.
7588 /// \param DiagID the primary error to report.
7589 /// \param MD the overriding method.
7590 /// \param OEK which overrides to include as notes.
7591 static void ReportOverrides(Sema& S, unsigned DiagID, const CXXMethodDecl *MD,
7592 OverrideErrorKind OEK = OEK_All) {
7593 S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
7594 for (const CXXMethodDecl *O : MD->overridden_methods()) {
7595 // This check (& the OEK parameter) could be replaced by a predicate, but
7596 // without lambdas that would be overkill. This is still nicer than writing
7597 // out the diag loop 3 times.
7598 if ((OEK == OEK_All) ||
7599 (OEK == OEK_NonDeleted && !O->isDeleted()) ||
7600 (OEK == OEK_Deleted && O->isDeleted()))
7601 S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
7605 /// AddOverriddenMethods - See if a method overrides any in the base classes,
7606 /// and if so, check that it's a valid override and remember it.
7607 bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
7608 // Look for methods in base classes that this method might override.
7610 FindOverriddenMethod FOM;
7613 bool hasDeletedOverridenMethods = false;
7614 bool hasNonDeletedOverridenMethods = false;
7615 bool AddedAny = false;
7616 if (DC->lookupInBases(FOM, Paths)) {
7617 for (auto *I : Paths.found_decls()) {
7618 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(I)) {
7619 MD->addOverriddenMethod(OldMD->getCanonicalDecl());
7620 if (!CheckOverridingFunctionReturnType(MD, OldMD) &&
7621 !CheckOverridingFunctionAttributes(MD, OldMD) &&
7622 !CheckOverridingFunctionExceptionSpec(MD, OldMD) &&
7623 !CheckIfOverriddenFunctionIsMarkedFinal(MD, OldMD)) {
7624 hasDeletedOverridenMethods |= OldMD->isDeleted();
7625 hasNonDeletedOverridenMethods |= !OldMD->isDeleted();
7632 if (hasDeletedOverridenMethods && !MD->isDeleted()) {
7633 ReportOverrides(*this, diag::err_non_deleted_override, MD, OEK_Deleted);
7635 if (hasNonDeletedOverridenMethods && MD->isDeleted()) {
7636 ReportOverrides(*this, diag::err_deleted_override, MD, OEK_NonDeleted);
7643 // Struct for holding all of the extra arguments needed by
7644 // DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator.
7645 struct ActOnFDArgs {
7648 MultiTemplateParamsArg TemplateParamLists;
7651 } // end anonymous namespace
7655 // Callback to only accept typo corrections that have a non-zero edit distance.
7656 // Also only accept corrections that have the same parent decl.
7657 class DifferentNameValidatorCCC : public CorrectionCandidateCallback {
7659 DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD,
7660 CXXRecordDecl *Parent)
7661 : Context(Context), OriginalFD(TypoFD),
7662 ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {}
7664 bool ValidateCandidate(const TypoCorrection &candidate) override {
7665 if (candidate.getEditDistance() == 0)
7668 SmallVector<unsigned, 1> MismatchedParams;
7669 for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(),
7670 CDeclEnd = candidate.end();
7671 CDecl != CDeclEnd; ++CDecl) {
7672 FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
7674 if (FD && !FD->hasBody() &&
7675 hasSimilarParameters(Context, FD, OriginalFD, MismatchedParams)) {
7676 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
7677 CXXRecordDecl *Parent = MD->getParent();
7678 if (Parent && Parent->getCanonicalDecl() == ExpectedParent)
7680 } else if (!ExpectedParent) {
7690 ASTContext &Context;
7691 FunctionDecl *OriginalFD;
7692 CXXRecordDecl *ExpectedParent;
7695 } // end anonymous namespace
7697 void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) {
7698 TypoCorrectedFunctionDefinitions.insert(F);
7701 /// Generate diagnostics for an invalid function redeclaration.
7703 /// This routine handles generating the diagnostic messages for an invalid
7704 /// function redeclaration, including finding possible similar declarations
7705 /// or performing typo correction if there are no previous declarations with
7708 /// Returns a NamedDecl iff typo correction was performed and substituting in
7709 /// the new declaration name does not cause new errors.
7710 static NamedDecl *DiagnoseInvalidRedeclaration(
7711 Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD,
7712 ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) {
7713 DeclarationName Name = NewFD->getDeclName();
7714 DeclContext *NewDC = NewFD->getDeclContext();
7715 SmallVector<unsigned, 1> MismatchedParams;
7716 SmallVector<std::pair<FunctionDecl *, unsigned>, 1> NearMatches;
7717 TypoCorrection Correction;
7718 bool IsDefinition = ExtraArgs.D.isFunctionDefinition();
7720 IsLocalFriend ? diag::err_no_matching_local_friend :
7721 NewFD->getFriendObjectKind() ? diag::err_qualified_friend_no_match :
7722 diag::err_member_decl_does_not_match;
7723 LookupResult Prev(SemaRef, Name, NewFD->getLocation(),
7724 IsLocalFriend ? Sema::LookupLocalFriendName
7725 : Sema::LookupOrdinaryName,
7726 Sema::ForVisibleRedeclaration);
7728 NewFD->setInvalidDecl();
7730 SemaRef.LookupName(Prev, S);
7732 SemaRef.LookupQualifiedName(Prev, NewDC);
7733 assert(!Prev.isAmbiguous() &&
7734 "Cannot have an ambiguity in previous-declaration lookup");
7735 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
7736 if (!Prev.empty()) {
7737 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
7738 Func != FuncEnd; ++Func) {
7739 FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func);
7741 hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
7742 // Add 1 to the index so that 0 can mean the mismatch didn't
7743 // involve a parameter
7745 MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1;
7746 NearMatches.push_back(std::make_pair(FD, ParamNum));
7749 // If the qualified name lookup yielded nothing, try typo correction
7750 } else if ((Correction = SemaRef.CorrectTypo(
7751 Prev.getLookupNameInfo(), Prev.getLookupKind(), S,
7752 &ExtraArgs.D.getCXXScopeSpec(),
7753 llvm::make_unique<DifferentNameValidatorCCC>(
7754 SemaRef.Context, NewFD, MD ? MD->getParent() : nullptr),
7755 Sema::CTK_ErrorRecovery, IsLocalFriend ? nullptr : NewDC))) {
7756 // Set up everything for the call to ActOnFunctionDeclarator
7757 ExtraArgs.D.SetIdentifier(Correction.getCorrectionAsIdentifierInfo(),
7758 ExtraArgs.D.getIdentifierLoc());
7760 Previous.setLookupName(Correction.getCorrection());
7761 for (TypoCorrection::decl_iterator CDecl = Correction.begin(),
7762 CDeclEnd = Correction.end();
7763 CDecl != CDeclEnd; ++CDecl) {
7764 FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
7765 if (FD && !FD->hasBody() &&
7766 hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
7767 Previous.addDecl(FD);
7770 bool wasRedeclaration = ExtraArgs.D.isRedeclaration();
7773 // Retry building the function declaration with the new previous
7774 // declarations, and with errors suppressed.
7777 Sema::SFINAETrap Trap(SemaRef);
7779 // TODO: Refactor ActOnFunctionDeclarator so that we can call only the
7780 // pieces need to verify the typo-corrected C++ declaration and hopefully
7781 // eliminate the need for the parameter pack ExtraArgs.
7782 Result = SemaRef.ActOnFunctionDeclarator(
7783 ExtraArgs.S, ExtraArgs.D,
7784 Correction.getCorrectionDecl()->getDeclContext(),
7785 NewFD->getTypeSourceInfo(), Previous, ExtraArgs.TemplateParamLists,
7786 ExtraArgs.AddToScope);
7788 if (Trap.hasErrorOccurred())
7793 // Determine which correction we picked.
7794 Decl *Canonical = Result->getCanonicalDecl();
7795 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7797 if ((*I)->getCanonicalDecl() == Canonical)
7798 Correction.setCorrectionDecl(*I);
7800 // Let Sema know about the correction.
7801 SemaRef.MarkTypoCorrectedFunctionDefinition(Result);
7802 SemaRef.diagnoseTypo(
7804 SemaRef.PDiag(IsLocalFriend
7805 ? diag::err_no_matching_local_friend_suggest
7806 : diag::err_member_decl_does_not_match_suggest)
7807 << Name << NewDC << IsDefinition);
7811 // Pretend the typo correction never occurred
7812 ExtraArgs.D.SetIdentifier(Name.getAsIdentifierInfo(),
7813 ExtraArgs.D.getIdentifierLoc());
7814 ExtraArgs.D.setRedeclaration(wasRedeclaration);
7816 Previous.setLookupName(Name);
7819 SemaRef.Diag(NewFD->getLocation(), DiagMsg)
7820 << Name << NewDC << IsDefinition << NewFD->getLocation();
7822 bool NewFDisConst = false;
7823 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD))
7824 NewFDisConst = NewMD->isConst();
7826 for (SmallVectorImpl<std::pair<FunctionDecl *, unsigned> >::iterator
7827 NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end();
7828 NearMatch != NearMatchEnd; ++NearMatch) {
7829 FunctionDecl *FD = NearMatch->first;
7830 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
7831 bool FDisConst = MD && MD->isConst();
7832 bool IsMember = MD || !IsLocalFriend;
7834 // FIXME: These notes are poorly worded for the local friend case.
7835 if (unsigned Idx = NearMatch->second) {
7836 ParmVarDecl *FDParam = FD->getParamDecl(Idx-1);
7837 SourceLocation Loc = FDParam->getTypeSpecStartLoc();
7838 if (Loc.isInvalid()) Loc = FD->getLocation();
7839 SemaRef.Diag(Loc, IsMember ? diag::note_member_def_close_param_match
7840 : diag::note_local_decl_close_param_match)
7841 << Idx << FDParam->getType()
7842 << NewFD->getParamDecl(Idx - 1)->getType();
7843 } else if (FDisConst != NewFDisConst) {
7844 SemaRef.Diag(FD->getLocation(), diag::note_member_def_close_const_match)
7845 << NewFDisConst << FD->getSourceRange().getEnd();
7847 SemaRef.Diag(FD->getLocation(),
7848 IsMember ? diag::note_member_def_close_match
7849 : diag::note_local_decl_close_match);
7854 static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) {
7855 switch (D.getDeclSpec().getStorageClassSpec()) {
7856 default: llvm_unreachable("Unknown storage class!");
7857 case DeclSpec::SCS_auto:
7858 case DeclSpec::SCS_register:
7859 case DeclSpec::SCS_mutable:
7860 SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
7861 diag::err_typecheck_sclass_func);
7862 D.getMutableDeclSpec().ClearStorageClassSpecs();
7865 case DeclSpec::SCS_unspecified: break;
7866 case DeclSpec::SCS_extern:
7867 if (D.getDeclSpec().isExternInLinkageSpec())
7870 case DeclSpec::SCS_static: {
7871 if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) {
7873 // The declaration of an identifier for a function that has
7874 // block scope shall have no explicit storage-class specifier
7875 // other than extern
7876 // See also (C++ [dcl.stc]p4).
7877 SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
7878 diag::err_static_block_func);
7883 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
7886 // No explicit storage class has already been returned
7890 static FunctionDecl* CreateNewFunctionDecl(Sema &SemaRef, Declarator &D,
7891 DeclContext *DC, QualType &R,
7892 TypeSourceInfo *TInfo,
7894 bool &IsVirtualOkay) {
7895 DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D);
7896 DeclarationName Name = NameInfo.getName();
7898 FunctionDecl *NewFD = nullptr;
7899 bool isInline = D.getDeclSpec().isInlineSpecified();
7901 if (!SemaRef.getLangOpts().CPlusPlus) {
7902 // Determine whether the function was written with a
7903 // prototype. This true when:
7904 // - there is a prototype in the declarator, or
7905 // - the type R of the function is some kind of typedef or other non-
7906 // attributed reference to a type name (which eventually refers to a
7909 (D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
7910 (!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());
7912 NewFD = FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo,
7913 R, TInfo, SC, isInline, HasPrototype, false);
7914 if (D.isInvalidType())
7915 NewFD->setInvalidDecl();
7920 bool isExplicit = D.getDeclSpec().isExplicitSpecified();
7921 bool isConstexpr = D.getDeclSpec().isConstexprSpecified();
7923 // Check that the return type is not an abstract class type.
7924 // For record types, this is done by the AbstractClassUsageDiagnoser once
7925 // the class has been completely parsed.
7926 if (!DC->isRecord() &&
7927 SemaRef.RequireNonAbstractType(
7928 D.getIdentifierLoc(), R->getAs<FunctionType>()->getReturnType(),
7929 diag::err_abstract_type_in_decl, SemaRef.AbstractReturnType))
7932 if (Name.getNameKind() == DeclarationName::CXXConstructorName) {
7933 // This is a C++ constructor declaration.
7934 assert(DC->isRecord() &&
7935 "Constructors can only be declared in a member context");
7937 R = SemaRef.CheckConstructorDeclarator(D, R, SC);
7938 return CXXConstructorDecl::Create(
7939 SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
7940 TInfo, isExplicit, isInline,
7941 /*isImplicitlyDeclared=*/false, isConstexpr);
7943 } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
7944 // This is a C++ destructor declaration.
7945 if (DC->isRecord()) {
7946 R = SemaRef.CheckDestructorDeclarator(D, R, SC);
7947 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
7948 CXXDestructorDecl *NewDD =
7949 CXXDestructorDecl::Create(SemaRef.Context, Record, D.getBeginLoc(),
7950 NameInfo, R, TInfo, isInline,
7951 /*isImplicitlyDeclared=*/false);
7953 // If the destructor needs an implicit exception specification, set it
7954 // now. FIXME: It'd be nice to be able to create the right type to start
7955 // with, but the type needs to reference the destructor declaration.
7956 if (SemaRef.getLangOpts().CPlusPlus11)
7957 SemaRef.AdjustDestructorExceptionSpec(NewDD);
7959 IsVirtualOkay = true;
7963 SemaRef.Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
7966 // Create a FunctionDecl to satisfy the function definition parsing
7968 return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(),
7969 D.getIdentifierLoc(), Name, R, TInfo, SC,
7971 /*hasPrototype=*/true, isConstexpr);
7974 } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
7975 if (!DC->isRecord()) {
7976 SemaRef.Diag(D.getIdentifierLoc(),
7977 diag::err_conv_function_not_member);
7981 SemaRef.CheckConversionDeclarator(D, R, SC);
7982 IsVirtualOkay = true;
7983 return CXXConversionDecl::Create(
7984 SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
7985 TInfo, isInline, isExplicit, isConstexpr, SourceLocation());
7987 } else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
7988 SemaRef.CheckDeductionGuideDeclarator(D, R, SC);
7990 return CXXDeductionGuideDecl::Create(SemaRef.Context, DC, D.getBeginLoc(),
7991 isExplicit, NameInfo, R, TInfo,
7993 } else if (DC->isRecord()) {
7994 // If the name of the function is the same as the name of the record,
7995 // then this must be an invalid constructor that has a return type.
7996 // (The parser checks for a return type and makes the declarator a
7997 // constructor if it has no return type).
7998 if (Name.getAsIdentifierInfo() &&
7999 Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){
8000 SemaRef.Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
8001 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
8002 << SourceRange(D.getIdentifierLoc());
8006 // This is a C++ method declaration.
8007 CXXMethodDecl *Ret = CXXMethodDecl::Create(
8008 SemaRef.Context, cast<CXXRecordDecl>(DC), D.getBeginLoc(), NameInfo, R,
8009 TInfo, SC, isInline, isConstexpr, SourceLocation());
8010 IsVirtualOkay = !Ret->isStatic();
8014 SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified();
8015 if (!isFriend && SemaRef.CurContext->isRecord())
8018 // Determine whether the function was written with a
8019 // prototype. This true when:
8020 // - we're in C++ (where every function has a prototype),
8021 return FunctionDecl::Create(SemaRef.Context, DC, D.getBeginLoc(), NameInfo,
8022 R, TInfo, SC, isInline, true /*HasPrototype*/,
8027 enum OpenCLParamType {
8031 InvalidAddrSpacePtrKernelParam,
8036 static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) {
8037 // Size dependent types are just typedefs to normal integer types
8038 // (e.g. unsigned long), so we cannot distinguish them from other typedefs to
8039 // integers other than by their names.
8040 StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"};
8042 // Remove typedefs one by one until we reach a typedef
8043 // for a size dependent type.
8044 QualType DesugaredTy = Ty;
8046 ArrayRef<StringRef> Names(SizeTypeNames);
8048 std::find(Names.begin(), Names.end(), DesugaredTy.getAsString());
8049 if (Names.end() != Match)
8053 DesugaredTy = Ty.getSingleStepDesugaredType(C);
8054 } while (DesugaredTy != Ty);
8059 static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) {
8060 if (PT->isPointerType()) {
8061 QualType PointeeType = PT->getPointeeType();
8062 if (PointeeType->isPointerType())
8063 return PtrPtrKernelParam;
8064 if (PointeeType.getAddressSpace() == LangAS::opencl_generic ||
8065 PointeeType.getAddressSpace() == LangAS::opencl_private ||
8066 PointeeType.getAddressSpace() == LangAS::Default)
8067 return InvalidAddrSpacePtrKernelParam;
8068 return PtrKernelParam;
8071 // OpenCL v1.2 s6.9.k:
8072 // Arguments to kernel functions in a program cannot be declared with the
8073 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
8074 // uintptr_t or a struct and/or union that contain fields declared to be one
8075 // of these built-in scalar types.
8076 if (isOpenCLSizeDependentType(S.getASTContext(), PT))
8077 return InvalidKernelParam;
8079 if (PT->isImageType())
8080 return PtrKernelParam;
8082 if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT())
8083 return InvalidKernelParam;
8085 // OpenCL extension spec v1.2 s9.5:
8086 // This extension adds support for half scalar and vector types as built-in
8087 // types that can be used for arithmetic operations, conversions etc.
8088 if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16") && PT->isHalfType())
8089 return InvalidKernelParam;
8091 if (PT->isRecordType())
8092 return RecordKernelParam;
8094 // Look into an array argument to check if it has a forbidden type.
8095 if (PT->isArrayType()) {
8096 const Type *UnderlyingTy = PT->getPointeeOrArrayElementType();
8097 // Call ourself to check an underlying type of an array. Since the
8098 // getPointeeOrArrayElementType returns an innermost type which is not an
8099 // array, this recursive call only happens once.
8100 return getOpenCLKernelParameterType(S, QualType(UnderlyingTy, 0));
8103 return ValidKernelParam;
8106 static void checkIsValidOpenCLKernelParameter(
8110 llvm::SmallPtrSetImpl<const Type *> &ValidTypes) {
8111 QualType PT = Param->getType();
8113 // Cache the valid types we encounter to avoid rechecking structs that are
8115 if (ValidTypes.count(PT.getTypePtr()))
8118 switch (getOpenCLKernelParameterType(S, PT)) {
8119 case PtrPtrKernelParam:
8120 // OpenCL v1.2 s6.9.a:
8121 // A kernel function argument cannot be declared as a
8122 // pointer to a pointer type.
8123 S.Diag(Param->getLocation(), diag::err_opencl_ptrptr_kernel_param);
8127 case InvalidAddrSpacePtrKernelParam:
8128 // OpenCL v1.0 s6.5:
8129 // __kernel function arguments declared to be a pointer of a type can point
8130 // to one of the following address spaces only : __global, __local or
8132 S.Diag(Param->getLocation(), diag::err_kernel_arg_address_space);
8136 // OpenCL v1.2 s6.9.k:
8137 // Arguments to kernel functions in a program cannot be declared with the
8138 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
8139 // uintptr_t or a struct and/or union that contain fields declared to be
8140 // one of these built-in scalar types.
8142 case InvalidKernelParam:
8143 // OpenCL v1.2 s6.8 n:
8144 // A kernel function argument cannot be declared
8146 // Do not diagnose half type since it is diagnosed as invalid argument
8147 // type for any function elsewhere.
8148 if (!PT->isHalfType()) {
8149 S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
8151 // Explain what typedefs are involved.
8152 const TypedefType *Typedef = nullptr;
8153 while ((Typedef = PT->getAs<TypedefType>())) {
8154 SourceLocation Loc = Typedef->getDecl()->getLocation();
8155 // SourceLocation may be invalid for a built-in type.
8157 S.Diag(Loc, diag::note_entity_declared_at) << PT;
8158 PT = Typedef->desugar();
8165 case PtrKernelParam:
8166 case ValidKernelParam:
8167 ValidTypes.insert(PT.getTypePtr());
8170 case RecordKernelParam:
8174 // Track nested structs we will inspect
8175 SmallVector<const Decl *, 4> VisitStack;
8177 // Track where we are in the nested structs. Items will migrate from
8178 // VisitStack to HistoryStack as we do the DFS for bad field.
8179 SmallVector<const FieldDecl *, 4> HistoryStack;
8180 HistoryStack.push_back(nullptr);
8182 // At this point we already handled everything except of a RecordType or
8183 // an ArrayType of a RecordType.
8184 assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type.");
8185 const RecordType *RecTy =
8186 PT->getPointeeOrArrayElementType()->getAs<RecordType>();
8187 const RecordDecl *OrigRecDecl = RecTy->getDecl();
8189 VisitStack.push_back(RecTy->getDecl());
8190 assert(VisitStack.back() && "First decl null?");
8193 const Decl *Next = VisitStack.pop_back_val();
8195 assert(!HistoryStack.empty());
8196 // Found a marker, we have gone up a level
8197 if (const FieldDecl *Hist = HistoryStack.pop_back_val())
8198 ValidTypes.insert(Hist->getType().getTypePtr());
8203 // Adds everything except the original parameter declaration (which is not a
8204 // field itself) to the history stack.
8205 const RecordDecl *RD;
8206 if (const FieldDecl *Field = dyn_cast<FieldDecl>(Next)) {
8207 HistoryStack.push_back(Field);
8209 QualType FieldTy = Field->getType();
8210 // Other field types (known to be valid or invalid) are handled while we
8211 // walk around RecordDecl::fields().
8212 assert((FieldTy->isArrayType() || FieldTy->isRecordType()) &&
8213 "Unexpected type.");
8214 const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType();
8216 RD = FieldRecTy->castAs<RecordType>()->getDecl();
8218 RD = cast<RecordDecl>(Next);
8221 // Add a null marker so we know when we've gone back up a level
8222 VisitStack.push_back(nullptr);
8224 for (const auto *FD : RD->fields()) {
8225 QualType QT = FD->getType();
8227 if (ValidTypes.count(QT.getTypePtr()))
8230 OpenCLParamType ParamType = getOpenCLKernelParameterType(S, QT);
8231 if (ParamType == ValidKernelParam)
8234 if (ParamType == RecordKernelParam) {
8235 VisitStack.push_back(FD);
8239 // OpenCL v1.2 s6.9.p:
8240 // Arguments to kernel functions that are declared to be a struct or union
8241 // do not allow OpenCL objects to be passed as elements of the struct or
8243 if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam ||
8244 ParamType == InvalidAddrSpacePtrKernelParam) {
8245 S.Diag(Param->getLocation(),
8246 diag::err_record_with_pointers_kernel_param)
8247 << PT->isUnionType()
8250 S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
8253 S.Diag(OrigRecDecl->getLocation(), diag::note_within_field_of_type)
8254 << OrigRecDecl->getDeclName();
8256 // We have an error, now let's go back up through history and show where
8257 // the offending field came from
8258 for (ArrayRef<const FieldDecl *>::const_iterator
8259 I = HistoryStack.begin() + 1,
8260 E = HistoryStack.end();
8262 const FieldDecl *OuterField = *I;
8263 S.Diag(OuterField->getLocation(), diag::note_within_field_of_type)
8264 << OuterField->getType();
8267 S.Diag(FD->getLocation(), diag::note_illegal_field_declared_here)
8268 << QT->isPointerType()
8273 } while (!VisitStack.empty());
8276 /// Find the DeclContext in which a tag is implicitly declared if we see an
8277 /// elaborated type specifier in the specified context, and lookup finds
8279 static DeclContext *getTagInjectionContext(DeclContext *DC) {
8280 while (!DC->isFileContext() && !DC->isFunctionOrMethod())
8281 DC = DC->getParent();
8285 /// Find the Scope in which a tag is implicitly declared if we see an
8286 /// elaborated type specifier in the specified context, and lookup finds
8288 static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) {
8289 while (S->isClassScope() ||
8290 (LangOpts.CPlusPlus &&
8291 S->isFunctionPrototypeScope()) ||
8292 ((S->getFlags() & Scope::DeclScope) == 0) ||
8293 (S->getEntity() && S->getEntity()->isTransparentContext()))
8299 Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
8300 TypeSourceInfo *TInfo, LookupResult &Previous,
8301 MultiTemplateParamsArg TemplateParamLists,
8303 QualType R = TInfo->getType();
8305 assert(R->isFunctionType());
8307 // TODO: consider using NameInfo for diagnostic.
8308 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
8309 DeclarationName Name = NameInfo.getName();
8310 StorageClass SC = getFunctionStorageClass(*this, D);
8312 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
8313 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
8314 diag::err_invalid_thread)
8315 << DeclSpec::getSpecifierName(TSCS);
8317 if (D.isFirstDeclarationOfMember())
8318 adjustMemberFunctionCC(R, D.isStaticMember(), D.isCtorOrDtor(),
8319 D.getIdentifierLoc());
8321 bool isFriend = false;
8322 FunctionTemplateDecl *FunctionTemplate = nullptr;
8323 bool isMemberSpecialization = false;
8324 bool isFunctionTemplateSpecialization = false;
8326 bool isDependentClassScopeExplicitSpecialization = false;
8327 bool HasExplicitTemplateArgs = false;
8328 TemplateArgumentListInfo TemplateArgs;
8330 bool isVirtualOkay = false;
8332 DeclContext *OriginalDC = DC;
8333 bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC);
8335 FunctionDecl *NewFD = CreateNewFunctionDecl(*this, D, DC, R, TInfo, SC,
8337 if (!NewFD) return nullptr;
8339 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer())
8340 NewFD->setTopLevelDeclInObjCContainer();
8342 // Set the lexical context. If this is a function-scope declaration, or has a
8343 // C++ scope specifier, or is the object of a friend declaration, the lexical
8344 // context will be different from the semantic context.
8345 NewFD->setLexicalDeclContext(CurContext);
8347 if (IsLocalExternDecl)
8348 NewFD->setLocalExternDecl();
8350 if (getLangOpts().CPlusPlus) {
8351 bool isInline = D.getDeclSpec().isInlineSpecified();
8352 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
8353 bool isExplicit = D.getDeclSpec().isExplicitSpecified();
8354 bool isConstexpr = D.getDeclSpec().isConstexprSpecified();
8355 isFriend = D.getDeclSpec().isFriendSpecified();
8356 if (isFriend && !isInline && D.isFunctionDefinition()) {
8357 // C++ [class.friend]p5
8358 // A function can be defined in a friend declaration of a
8359 // class . . . . Such a function is implicitly inline.
8360 NewFD->setImplicitlyInline();
8363 // If this is a method defined in an __interface, and is not a constructor
8364 // or an overloaded operator, then set the pure flag (isVirtual will already
8366 if (const CXXRecordDecl *Parent =
8367 dyn_cast<CXXRecordDecl>(NewFD->getDeclContext())) {
8368 if (Parent->isInterface() && cast<CXXMethodDecl>(NewFD)->isUserProvided())
8369 NewFD->setPure(true);
8371 // C++ [class.union]p2
8372 // A union can have member functions, but not virtual functions.
8373 if (isVirtual && Parent->isUnion())
8374 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_in_union);
8377 SetNestedNameSpecifier(*this, NewFD, D);
8378 isMemberSpecialization = false;
8379 isFunctionTemplateSpecialization = false;
8380 if (D.isInvalidType())
8381 NewFD->setInvalidDecl();
8383 // Match up the template parameter lists with the scope specifier, then
8384 // determine whether we have a template or a template specialization.
8385 bool Invalid = false;
8386 if (TemplateParameterList *TemplateParams =
8387 MatchTemplateParametersToScopeSpecifier(
8388 D.getDeclSpec().getBeginLoc(), D.getIdentifierLoc(),
8389 D.getCXXScopeSpec(),
8390 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
8391 ? D.getName().TemplateId
8393 TemplateParamLists, isFriend, isMemberSpecialization,
8395 if (TemplateParams->size() > 0) {
8396 // This is a function template
8398 // Check that we can declare a template here.
8399 if (CheckTemplateDeclScope(S, TemplateParams))
8400 NewFD->setInvalidDecl();
8402 // A destructor cannot be a template.
8403 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
8404 Diag(NewFD->getLocation(), diag::err_destructor_template);
8405 NewFD->setInvalidDecl();
8408 // If we're adding a template to a dependent context, we may need to
8409 // rebuilding some of the types used within the template parameter list,
8410 // now that we know what the current instantiation is.
8411 if (DC->isDependentContext()) {
8412 ContextRAII SavedContext(*this, DC);
8413 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
8417 FunctionTemplate = FunctionTemplateDecl::Create(Context, DC,
8418 NewFD->getLocation(),
8419 Name, TemplateParams,
8421 FunctionTemplate->setLexicalDeclContext(CurContext);
8422 NewFD->setDescribedFunctionTemplate(FunctionTemplate);
8424 // For source fidelity, store the other template param lists.
8425 if (TemplateParamLists.size() > 1) {
8426 NewFD->setTemplateParameterListsInfo(Context,
8427 TemplateParamLists.drop_back(1));
8430 // This is a function template specialization.
8431 isFunctionTemplateSpecialization = true;
8432 // For source fidelity, store all the template param lists.
8433 if (TemplateParamLists.size() > 0)
8434 NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
8436 // C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);".
8438 // We want to remove the "template<>", found here.
8439 SourceRange RemoveRange = TemplateParams->getSourceRange();
8441 // If we remove the template<> and the name is not a
8442 // template-id, we're actually silently creating a problem:
8443 // the friend declaration will refer to an untemplated decl,
8444 // and clearly the user wants a template specialization. So
8445 // we need to insert '<>' after the name.
8446 SourceLocation InsertLoc;
8447 if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
8448 InsertLoc = D.getName().getSourceRange().getEnd();
8449 InsertLoc = getLocForEndOfToken(InsertLoc);
8452 Diag(D.getIdentifierLoc(), diag::err_template_spec_decl_friend)
8453 << Name << RemoveRange
8454 << FixItHint::CreateRemoval(RemoveRange)
8455 << FixItHint::CreateInsertion(InsertLoc, "<>");
8459 // All template param lists were matched against the scope specifier:
8460 // this is NOT (an explicit specialization of) a template.
8461 if (TemplateParamLists.size() > 0)
8462 // For source fidelity, store all the template param lists.
8463 NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
8467 NewFD->setInvalidDecl();
8468 if (FunctionTemplate)
8469 FunctionTemplate->setInvalidDecl();
8472 // C++ [dcl.fct.spec]p5:
8473 // The virtual specifier shall only be used in declarations of
8474 // nonstatic class member functions that appear within a
8475 // member-specification of a class declaration; see 10.3.
8477 if (isVirtual && !NewFD->isInvalidDecl()) {
8478 if (!isVirtualOkay) {
8479 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8480 diag::err_virtual_non_function);
8481 } else if (!CurContext->isRecord()) {
8482 // 'virtual' was specified outside of the class.
8483 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8484 diag::err_virtual_out_of_class)
8485 << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
8486 } else if (NewFD->getDescribedFunctionTemplate()) {
8487 // C++ [temp.mem]p3:
8488 // A member function template shall not be virtual.
8489 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8490 diag::err_virtual_member_function_template)
8491 << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
8493 // Okay: Add virtual to the method.
8494 NewFD->setVirtualAsWritten(true);
8497 if (getLangOpts().CPlusPlus14 &&
8498 NewFD->getReturnType()->isUndeducedType())
8499 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_auto_fn_virtual);
8502 if (getLangOpts().CPlusPlus14 &&
8503 (NewFD->isDependentContext() ||
8504 (isFriend && CurContext->isDependentContext())) &&
8505 NewFD->getReturnType()->isUndeducedType()) {
8506 // If the function template is referenced directly (for instance, as a
8507 // member of the current instantiation), pretend it has a dependent type.
8508 // This is not really justified by the standard, but is the only sane
8510 // FIXME: For a friend function, we have not marked the function as being
8511 // a friend yet, so 'isDependentContext' on the FD doesn't work.
8512 const FunctionProtoType *FPT =
8513 NewFD->getType()->castAs<FunctionProtoType>();
8515 SubstAutoType(FPT->getReturnType(), Context.DependentTy);
8516 NewFD->setType(Context.getFunctionType(Result, FPT->getParamTypes(),
8517 FPT->getExtProtoInfo()));
8520 // C++ [dcl.fct.spec]p3:
8521 // The inline specifier shall not appear on a block scope function
8523 if (isInline && !NewFD->isInvalidDecl()) {
8524 if (CurContext->isFunctionOrMethod()) {
8525 // 'inline' is not allowed on block scope function declaration.
8526 Diag(D.getDeclSpec().getInlineSpecLoc(),
8527 diag::err_inline_declaration_block_scope) << Name
8528 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
8532 // C++ [dcl.fct.spec]p6:
8533 // The explicit specifier shall be used only in the declaration of a
8534 // constructor or conversion function within its class definition;
8535 // see 12.3.1 and 12.3.2.
8536 if (isExplicit && !NewFD->isInvalidDecl() &&
8537 !isa<CXXDeductionGuideDecl>(NewFD)) {
8538 if (!CurContext->isRecord()) {
8539 // 'explicit' was specified outside of the class.
8540 Diag(D.getDeclSpec().getExplicitSpecLoc(),
8541 diag::err_explicit_out_of_class)
8542 << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc());
8543 } else if (!isa<CXXConstructorDecl>(NewFD) &&
8544 !isa<CXXConversionDecl>(NewFD)) {
8545 // 'explicit' was specified on a function that wasn't a constructor
8546 // or conversion function.
8547 Diag(D.getDeclSpec().getExplicitSpecLoc(),
8548 diag::err_explicit_non_ctor_or_conv_function)
8549 << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc());
8554 // C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors
8555 // are implicitly inline.
8556 NewFD->setImplicitlyInline();
8558 // C++11 [dcl.constexpr]p3: functions declared constexpr are required to
8559 // be either constructors or to return a literal type. Therefore,
8560 // destructors cannot be declared constexpr.
8561 if (isa<CXXDestructorDecl>(NewFD))
8562 Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor);
8565 // If __module_private__ was specified, mark the function accordingly.
8566 if (D.getDeclSpec().isModulePrivateSpecified()) {
8567 if (isFunctionTemplateSpecialization) {
8568 SourceLocation ModulePrivateLoc
8569 = D.getDeclSpec().getModulePrivateSpecLoc();
8570 Diag(ModulePrivateLoc, diag::err_module_private_specialization)
8572 << FixItHint::CreateRemoval(ModulePrivateLoc);
8574 NewFD->setModulePrivate();
8575 if (FunctionTemplate)
8576 FunctionTemplate->setModulePrivate();
8581 if (FunctionTemplate) {
8582 FunctionTemplate->setObjectOfFriendDecl();
8583 FunctionTemplate->setAccess(AS_public);
8585 NewFD->setObjectOfFriendDecl();
8586 NewFD->setAccess(AS_public);
8589 // If a function is defined as defaulted or deleted, mark it as such now.
8590 // FIXME: Does this ever happen? ActOnStartOfFunctionDef forces the function
8591 // definition kind to FDK_Definition.
8592 switch (D.getFunctionDefinitionKind()) {
8593 case FDK_Declaration:
8594 case FDK_Definition:
8598 NewFD->setDefaulted();
8602 NewFD->setDeletedAsWritten();
8606 if (isa<CXXMethodDecl>(NewFD) && DC == CurContext &&
8607 D.isFunctionDefinition()) {
8608 // C++ [class.mfct]p2:
8609 // A member function may be defined (8.4) in its class definition, in
8610 // which case it is an inline member function (7.1.2)
8611 NewFD->setImplicitlyInline();
8614 if (SC == SC_Static && isa<CXXMethodDecl>(NewFD) &&
8615 !CurContext->isRecord()) {
8616 // C++ [class.static]p1:
8617 // A data or function member of a class may be declared static
8618 // in a class definition, in which case it is a static member of
8621 // Complain about the 'static' specifier if it's on an out-of-line
8622 // member function definition.
8623 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
8624 diag::err_static_out_of_line)
8625 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8628 // C++11 [except.spec]p15:
8629 // A deallocation function with no exception-specification is treated
8630 // as if it were specified with noexcept(true).
8631 const FunctionProtoType *FPT = R->getAs<FunctionProtoType>();
8632 if ((Name.getCXXOverloadedOperator() == OO_Delete ||
8633 Name.getCXXOverloadedOperator() == OO_Array_Delete) &&
8634 getLangOpts().CPlusPlus11 && FPT && !FPT->hasExceptionSpec())
8635 NewFD->setType(Context.getFunctionType(
8636 FPT->getReturnType(), FPT->getParamTypes(),
8637 FPT->getExtProtoInfo().withExceptionSpec(EST_BasicNoexcept)));
8640 // Filter out previous declarations that don't match the scope.
8641 FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD),
8642 D.getCXXScopeSpec().isNotEmpty() ||
8643 isMemberSpecialization ||
8644 isFunctionTemplateSpecialization);
8646 // Handle GNU asm-label extension (encoded as an attribute).
8647 if (Expr *E = (Expr*) D.getAsmLabel()) {
8648 // The parser guarantees this is a string.
8649 StringLiteral *SE = cast<StringLiteral>(E);
8650 NewFD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0), Context,
8651 SE->getString(), 0));
8652 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
8653 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
8654 ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
8655 if (I != ExtnameUndeclaredIdentifiers.end()) {
8656 if (isDeclExternC(NewFD)) {
8657 NewFD->addAttr(I->second);
8658 ExtnameUndeclaredIdentifiers.erase(I);
8660 Diag(NewFD->getLocation(), diag::warn_redefine_extname_not_applied)
8661 << /*Variable*/0 << NewFD;
8665 // Copy the parameter declarations from the declarator D to the function
8666 // declaration NewFD, if they are available. First scavenge them into Params.
8667 SmallVector<ParmVarDecl*, 16> Params;
8669 if (D.isFunctionDeclarator(FTIIdx)) {
8670 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(FTIIdx).Fun;
8672 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
8673 // function that takes no arguments, not a function that takes a
8674 // single void argument.
8675 // We let through "const void" here because Sema::GetTypeForDeclarator
8676 // already checks for that case.
8677 if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) {
8678 for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
8679 ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
8680 assert(Param->getDeclContext() != NewFD && "Was set before ?");
8681 Param->setDeclContext(NewFD);
8682 Params.push_back(Param);
8684 if (Param->isInvalidDecl())
8685 NewFD->setInvalidDecl();
8689 if (!getLangOpts().CPlusPlus) {
8690 // In C, find all the tag declarations from the prototype and move them
8691 // into the function DeclContext. Remove them from the surrounding tag
8692 // injection context of the function, which is typically but not always
8694 DeclContext *PrototypeTagContext =
8695 getTagInjectionContext(NewFD->getLexicalDeclContext());
8696 for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) {
8697 auto *TD = dyn_cast<TagDecl>(NonParmDecl);
8699 // We don't want to reparent enumerators. Look at their parent enum
8702 if (auto *ECD = dyn_cast<EnumConstantDecl>(NonParmDecl))
8703 TD = cast<EnumDecl>(ECD->getDeclContext());
8707 DeclContext *TagDC = TD->getLexicalDeclContext();
8708 if (!TagDC->containsDecl(TD))
8710 TagDC->removeDecl(TD);
8711 TD->setDeclContext(NewFD);
8714 // Preserve the lexical DeclContext if it is not the surrounding tag
8715 // injection context of the FD. In this example, the semantic context of
8716 // E will be f and the lexical context will be S, while both the
8717 // semantic and lexical contexts of S will be f:
8718 // void f(struct S { enum E { a } f; } s);
8719 if (TagDC != PrototypeTagContext)
8720 TD->setLexicalDeclContext(TagDC);
8723 } else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) {
8724 // When we're declaring a function with a typedef, typeof, etc as in the
8725 // following example, we'll need to synthesize (unnamed)
8726 // parameters for use in the declaration.
8729 // typedef void fn(int);
8733 // Synthesize a parameter for each argument type.
8734 for (const auto &AI : FT->param_types()) {
8735 ParmVarDecl *Param =
8736 BuildParmVarDeclForTypedef(NewFD, D.getIdentifierLoc(), AI);
8737 Param->setScopeInfo(0, Params.size());
8738 Params.push_back(Param);
8741 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&
8742 "Should not need args for typedef of non-prototype fn");
8745 // Finally, we know we have the right number of parameters, install them.
8746 NewFD->setParams(Params);
8748 if (D.getDeclSpec().isNoreturnSpecified())
8750 ::new(Context) C11NoReturnAttr(D.getDeclSpec().getNoreturnSpecLoc(),
8753 // Functions returning a variably modified type violate C99 6.7.5.2p2
8754 // because all functions have linkage.
8755 if (!NewFD->isInvalidDecl() &&
8756 NewFD->getReturnType()->isVariablyModifiedType()) {
8757 Diag(NewFD->getLocation(), diag::err_vm_func_decl);
8758 NewFD->setInvalidDecl();
8761 // Apply an implicit SectionAttr if '#pragma clang section text' is active
8762 if (PragmaClangTextSection.Valid && D.isFunctionDefinition() &&
8763 !NewFD->hasAttr<SectionAttr>()) {
8764 NewFD->addAttr(PragmaClangTextSectionAttr::CreateImplicit(Context,
8765 PragmaClangTextSection.SectionName,
8766 PragmaClangTextSection.PragmaLocation));
8769 // Apply an implicit SectionAttr if #pragma code_seg is active.
8770 if (CodeSegStack.CurrentValue && D.isFunctionDefinition() &&
8771 !NewFD->hasAttr<SectionAttr>()) {
8773 SectionAttr::CreateImplicit(Context, SectionAttr::Declspec_allocate,
8774 CodeSegStack.CurrentValue->getString(),
8775 CodeSegStack.CurrentPragmaLocation));
8776 if (UnifySection(CodeSegStack.CurrentValue->getString(),
8777 ASTContext::PSF_Implicit | ASTContext::PSF_Execute |
8778 ASTContext::PSF_Read,
8780 NewFD->dropAttr<SectionAttr>();
8783 // Apply an implicit CodeSegAttr from class declspec or
8784 // apply an implicit SectionAttr from #pragma code_seg if active.
8785 if (!NewFD->hasAttr<CodeSegAttr>()) {
8786 if (Attr *SAttr = getImplicitCodeSegOrSectionAttrForFunction(NewFD,
8787 D.isFunctionDefinition())) {
8788 NewFD->addAttr(SAttr);
8792 // Handle attributes.
8793 ProcessDeclAttributes(S, NewFD, D);
8795 if (getLangOpts().OpenCL) {
8796 // OpenCL v1.1 s6.5: Using an address space qualifier in a function return
8797 // type declaration will generate a compilation error.
8798 LangAS AddressSpace = NewFD->getReturnType().getAddressSpace();
8799 if (AddressSpace != LangAS::Default) {
8800 Diag(NewFD->getLocation(),
8801 diag::err_opencl_return_value_with_address_space);
8802 NewFD->setInvalidDecl();
8806 if (!getLangOpts().CPlusPlus) {
8807 // Perform semantic checking on the function declaration.
8808 if (!NewFD->isInvalidDecl() && NewFD->isMain())
8809 CheckMain(NewFD, D.getDeclSpec());
8811 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
8812 CheckMSVCRTEntryPoint(NewFD);
8814 if (!NewFD->isInvalidDecl())
8815 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
8816 isMemberSpecialization));
8817 else if (!Previous.empty())
8818 // Recover gracefully from an invalid redeclaration.
8819 D.setRedeclaration(true);
8820 assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
8821 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
8822 "previous declaration set still overloaded");
8824 // Diagnose no-prototype function declarations with calling conventions that
8825 // don't support variadic calls. Only do this in C and do it after merging
8826 // possibly prototyped redeclarations.
8827 const FunctionType *FT = NewFD->getType()->castAs<FunctionType>();
8828 if (isa<FunctionNoProtoType>(FT) && !D.isFunctionDefinition()) {
8829 CallingConv CC = FT->getExtInfo().getCC();
8830 if (!supportsVariadicCall(CC)) {
8831 // Windows system headers sometimes accidentally use stdcall without
8832 // (void) parameters, so we relax this to a warning.
8834 CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr;
8835 Diag(NewFD->getLocation(), DiagID)
8836 << FunctionType::getNameForCallConv(CC);
8840 // C++11 [replacement.functions]p3:
8841 // The program's definitions shall not be specified as inline.
8843 // N.B. We diagnose declarations instead of definitions per LWG issue 2340.
8845 // Suppress the diagnostic if the function is __attribute__((used)), since
8846 // that forces an external definition to be emitted.
8847 if (D.getDeclSpec().isInlineSpecified() &&
8848 NewFD->isReplaceableGlobalAllocationFunction() &&
8849 !NewFD->hasAttr<UsedAttr>())
8850 Diag(D.getDeclSpec().getInlineSpecLoc(),
8851 diag::ext_operator_new_delete_declared_inline)
8852 << NewFD->getDeclName();
8854 // If the declarator is a template-id, translate the parser's template
8855 // argument list into our AST format.
8856 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
8857 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
8858 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
8859 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
8860 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
8861 TemplateId->NumArgs);
8862 translateTemplateArguments(TemplateArgsPtr,
8865 HasExplicitTemplateArgs = true;
8867 if (NewFD->isInvalidDecl()) {
8868 HasExplicitTemplateArgs = false;
8869 } else if (FunctionTemplate) {
8870 // Function template with explicit template arguments.
8871 Diag(D.getIdentifierLoc(), diag::err_function_template_partial_spec)
8872 << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc);
8874 HasExplicitTemplateArgs = false;
8876 assert((isFunctionTemplateSpecialization ||
8877 D.getDeclSpec().isFriendSpecified()) &&
8878 "should have a 'template<>' for this decl");
8879 // "friend void foo<>(int);" is an implicit specialization decl.
8880 isFunctionTemplateSpecialization = true;
8882 } else if (isFriend && isFunctionTemplateSpecialization) {
8883 // This combination is only possible in a recovery case; the user
8884 // wrote something like:
8885 // template <> friend void foo(int);
8886 // which we're recovering from as if the user had written:
8887 // friend void foo<>(int);
8888 // Go ahead and fake up a template id.
8889 HasExplicitTemplateArgs = true;
8890 TemplateArgs.setLAngleLoc(D.getIdentifierLoc());
8891 TemplateArgs.setRAngleLoc(D.getIdentifierLoc());
8894 // We do not add HD attributes to specializations here because
8895 // they may have different constexpr-ness compared to their
8896 // templates and, after maybeAddCUDAHostDeviceAttrs() is applied,
8897 // may end up with different effective targets. Instead, a
8898 // specialization inherits its target attributes from its template
8899 // in the CheckFunctionTemplateSpecialization() call below.
8900 if (getLangOpts().CUDA & !isFunctionTemplateSpecialization)
8901 maybeAddCUDAHostDeviceAttrs(NewFD, Previous);
8903 // If it's a friend (and only if it's a friend), it's possible
8904 // that either the specialized function type or the specialized
8905 // template is dependent, and therefore matching will fail. In
8906 // this case, don't check the specialization yet.
8907 bool InstantiationDependent = false;
8908 if (isFunctionTemplateSpecialization && isFriend &&
8909 (NewFD->getType()->isDependentType() || DC->isDependentContext() ||
8910 TemplateSpecializationType::anyDependentTemplateArguments(
8912 InstantiationDependent))) {
8913 assert(HasExplicitTemplateArgs &&
8914 "friend function specialization without template args");
8915 if (CheckDependentFunctionTemplateSpecialization(NewFD, TemplateArgs,
8917 NewFD->setInvalidDecl();
8918 } else if (isFunctionTemplateSpecialization) {
8919 if (CurContext->isDependentContext() && CurContext->isRecord()
8921 isDependentClassScopeExplicitSpecialization = true;
8922 } else if (!NewFD->isInvalidDecl() &&
8923 CheckFunctionTemplateSpecialization(
8924 NewFD, (HasExplicitTemplateArgs ? &TemplateArgs : nullptr),
8926 NewFD->setInvalidDecl();
8929 // A storage-class-specifier shall not be specified in an explicit
8930 // specialization (14.7.3)
8931 FunctionTemplateSpecializationInfo *Info =
8932 NewFD->getTemplateSpecializationInfo();
8933 if (Info && SC != SC_None) {
8934 if (SC != Info->getTemplate()->getTemplatedDecl()->getStorageClass())
8935 Diag(NewFD->getLocation(),
8936 diag::err_explicit_specialization_inconsistent_storage_class)
8938 << FixItHint::CreateRemoval(
8939 D.getDeclSpec().getStorageClassSpecLoc());
8942 Diag(NewFD->getLocation(),
8943 diag::ext_explicit_specialization_storage_class)
8944 << FixItHint::CreateRemoval(
8945 D.getDeclSpec().getStorageClassSpecLoc());
8947 } else if (isMemberSpecialization && isa<CXXMethodDecl>(NewFD)) {
8948 if (CheckMemberSpecialization(NewFD, Previous))
8949 NewFD->setInvalidDecl();
8952 // Perform semantic checking on the function declaration.
8953 if (!isDependentClassScopeExplicitSpecialization) {
8954 if (!NewFD->isInvalidDecl() && NewFD->isMain())
8955 CheckMain(NewFD, D.getDeclSpec());
8957 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
8958 CheckMSVCRTEntryPoint(NewFD);
8960 if (!NewFD->isInvalidDecl())
8961 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
8962 isMemberSpecialization));
8963 else if (!Previous.empty())
8964 // Recover gracefully from an invalid redeclaration.
8965 D.setRedeclaration(true);
8968 assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
8969 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
8970 "previous declaration set still overloaded");
8972 NamedDecl *PrincipalDecl = (FunctionTemplate
8973 ? cast<NamedDecl>(FunctionTemplate)
8976 if (isFriend && NewFD->getPreviousDecl()) {
8977 AccessSpecifier Access = AS_public;
8978 if (!NewFD->isInvalidDecl())
8979 Access = NewFD->getPreviousDecl()->getAccess();
8981 NewFD->setAccess(Access);
8982 if (FunctionTemplate) FunctionTemplate->setAccess(Access);
8985 if (NewFD->isOverloadedOperator() && !DC->isRecord() &&
8986 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
8987 PrincipalDecl->setNonMemberOperator();
8989 // If we have a function template, check the template parameter
8990 // list. This will check and merge default template arguments.
8991 if (FunctionTemplate) {
8992 FunctionTemplateDecl *PrevTemplate =
8993 FunctionTemplate->getPreviousDecl();
8994 CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(),
8995 PrevTemplate ? PrevTemplate->getTemplateParameters()
8997 D.getDeclSpec().isFriendSpecified()
8998 ? (D.isFunctionDefinition()
8999 ? TPC_FriendFunctionTemplateDefinition
9000 : TPC_FriendFunctionTemplate)
9001 : (D.getCXXScopeSpec().isSet() &&
9002 DC && DC->isRecord() &&
9003 DC->isDependentContext())
9004 ? TPC_ClassTemplateMember
9005 : TPC_FunctionTemplate);
9008 if (NewFD->isInvalidDecl()) {
9009 // Ignore all the rest of this.
9010 } else if (!D.isRedeclaration()) {
9011 struct ActOnFDArgs ExtraArgs = { S, D, TemplateParamLists,
9013 // Fake up an access specifier if it's supposed to be a class member.
9014 if (isa<CXXRecordDecl>(NewFD->getDeclContext()))
9015 NewFD->setAccess(AS_public);
9017 // Qualified decls generally require a previous declaration.
9018 if (D.getCXXScopeSpec().isSet()) {
9019 // ...with the major exception of templated-scope or
9020 // dependent-scope friend declarations.
9022 // TODO: we currently also suppress this check in dependent
9023 // contexts because (1) the parameter depth will be off when
9024 // matching friend templates and (2) we might actually be
9025 // selecting a friend based on a dependent factor. But there
9026 // are situations where these conditions don't apply and we
9027 // can actually do this check immediately.
9029 // Unless the scope is dependent, it's always an error if qualified
9030 // redeclaration lookup found nothing at all. Diagnose that now;
9031 // nothing will diagnose that error later.
9033 (D.getCXXScopeSpec().getScopeRep()->isDependent() ||
9034 (!Previous.empty() && (TemplateParamLists.size() ||
9035 CurContext->isDependentContext())))) {
9038 // The user tried to provide an out-of-line definition for a
9039 // function that is a member of a class or namespace, but there
9040 // was no such member function declared (C++ [class.mfct]p2,
9041 // C++ [namespace.memdef]p2). For example:
9047 // void X::f() { } // ill-formed
9049 // Complain about this problem, and attempt to suggest close
9050 // matches (e.g., those that differ only in cv-qualifiers and
9051 // whether the parameter types are references).
9053 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
9054 *this, Previous, NewFD, ExtraArgs, false, nullptr)) {
9055 AddToScope = ExtraArgs.AddToScope;
9060 // Unqualified local friend declarations are required to resolve
9062 } else if (isFriend && cast<CXXRecordDecl>(CurContext)->isLocalClass()) {
9063 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
9064 *this, Previous, NewFD, ExtraArgs, true, S)) {
9065 AddToScope = ExtraArgs.AddToScope;
9069 } else if (!D.isFunctionDefinition() &&
9070 isa<CXXMethodDecl>(NewFD) && NewFD->isOutOfLine() &&
9071 !isFriend && !isFunctionTemplateSpecialization &&
9072 !isMemberSpecialization) {
9073 // An out-of-line member function declaration must also be a
9074 // definition (C++ [class.mfct]p2).
9075 // Note that this is not the case for explicit specializations of
9076 // function templates or member functions of class templates, per
9077 // C++ [temp.expl.spec]p2. We also allow these declarations as an
9078 // extension for compatibility with old SWIG code which likes to
9080 Diag(NewFD->getLocation(), diag::ext_out_of_line_declaration)
9081 << D.getCXXScopeSpec().getRange();
9085 ProcessPragmaWeak(S, NewFD);
9086 checkAttributesAfterMerging(*this, *NewFD);
9088 AddKnownFunctionAttributes(NewFD);
9090 if (NewFD->hasAttr<OverloadableAttr>() &&
9091 !NewFD->getType()->getAs<FunctionProtoType>()) {
9092 Diag(NewFD->getLocation(),
9093 diag::err_attribute_overloadable_no_prototype)
9096 // Turn this into a variadic function with no parameters.
9097 const FunctionType *FT = NewFD->getType()->getAs<FunctionType>();
9098 FunctionProtoType::ExtProtoInfo EPI(
9099 Context.getDefaultCallingConvention(true, false));
9100 EPI.Variadic = true;
9101 EPI.ExtInfo = FT->getExtInfo();
9103 QualType R = Context.getFunctionType(FT->getReturnType(), None, EPI);
9107 // If there's a #pragma GCC visibility in scope, and this isn't a class
9108 // member, set the visibility of this function.
9109 if (!DC->isRecord() && NewFD->isExternallyVisible())
9110 AddPushedVisibilityAttribute(NewFD);
9112 // If there's a #pragma clang arc_cf_code_audited in scope, consider
9113 // marking the function.
9114 AddCFAuditedAttribute(NewFD);
9116 // If this is a function definition, check if we have to apply optnone due to
9118 if(D.isFunctionDefinition())
9119 AddRangeBasedOptnone(NewFD);
9121 // If this is the first declaration of an extern C variable, update
9122 // the map of such variables.
9123 if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() &&
9124 isIncompleteDeclExternC(*this, NewFD))
9125 RegisterLocallyScopedExternCDecl(NewFD, S);
9127 // Set this FunctionDecl's range up to the right paren.
9128 NewFD->setRangeEnd(D.getSourceRange().getEnd());
9130 if (D.isRedeclaration() && !Previous.empty()) {
9131 NamedDecl *Prev = Previous.getRepresentativeDecl();
9132 checkDLLAttributeRedeclaration(*this, Prev, NewFD,
9133 isMemberSpecialization ||
9134 isFunctionTemplateSpecialization,
9135 D.isFunctionDefinition());
9138 if (getLangOpts().CUDA) {
9139 IdentifierInfo *II = NewFD->getIdentifier();
9141 II->isStr(getLangOpts().HIP ? "hipConfigureCall"
9142 : "cudaConfigureCall") &&
9143 !NewFD->isInvalidDecl() &&
9144 NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
9145 if (!R->getAs<FunctionType>()->getReturnType()->isScalarType())
9146 Diag(NewFD->getLocation(), diag::err_config_scalar_return);
9147 Context.setcudaConfigureCallDecl(NewFD);
9150 // Variadic functions, other than a *declaration* of printf, are not allowed
9151 // in device-side CUDA code, unless someone passed
9152 // -fcuda-allow-variadic-functions.
9153 if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() &&
9154 (NewFD->hasAttr<CUDADeviceAttr>() ||
9155 NewFD->hasAttr<CUDAGlobalAttr>()) &&
9156 !(II && II->isStr("printf") && NewFD->isExternC() &&
9157 !D.isFunctionDefinition())) {
9158 Diag(NewFD->getLocation(), diag::err_variadic_device_fn);
9162 MarkUnusedFileScopedDecl(NewFD);
9164 if (getLangOpts().CPlusPlus) {
9165 if (FunctionTemplate) {
9166 if (NewFD->isInvalidDecl())
9167 FunctionTemplate->setInvalidDecl();
9168 return FunctionTemplate;
9171 if (isMemberSpecialization && !NewFD->isInvalidDecl())
9172 CompleteMemberSpecialization(NewFD, Previous);
9175 if (NewFD->hasAttr<OpenCLKernelAttr>()) {
9176 // OpenCL v1.2 s6.8 static is invalid for kernel functions.
9177 if ((getLangOpts().OpenCLVersion >= 120)
9178 && (SC == SC_Static)) {
9179 Diag(D.getIdentifierLoc(), diag::err_static_kernel);
9183 // OpenCL v1.2, s6.9 -- Kernels can only have return type void.
9184 if (!NewFD->getReturnType()->isVoidType()) {
9185 SourceRange RTRange = NewFD->getReturnTypeSourceRange();
9186 Diag(D.getIdentifierLoc(), diag::err_expected_kernel_void_return_type)
9187 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "void")
9192 llvm::SmallPtrSet<const Type *, 16> ValidTypes;
9193 for (auto Param : NewFD->parameters())
9194 checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes);
9196 for (const ParmVarDecl *Param : NewFD->parameters()) {
9197 QualType PT = Param->getType();
9199 // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value
9201 if (getLangOpts().OpenCLVersion >= 200) {
9202 if(const PipeType *PipeTy = PT->getAs<PipeType>()) {
9203 QualType ElemTy = PipeTy->getElementType();
9204 if (ElemTy->isReferenceType() || ElemTy->isPointerType()) {
9205 Diag(Param->getTypeSpecStartLoc(), diag::err_reference_pipe_type );
9212 // Here we have an function template explicit specialization at class scope.
9213 // The actual specialization will be postponed to template instatiation
9214 // time via the ClassScopeFunctionSpecializationDecl node.
9215 if (isDependentClassScopeExplicitSpecialization) {
9216 ClassScopeFunctionSpecializationDecl *NewSpec =
9217 ClassScopeFunctionSpecializationDecl::Create(
9218 Context, CurContext, NewFD->getLocation(),
9219 cast<CXXMethodDecl>(NewFD),
9220 HasExplicitTemplateArgs, TemplateArgs);
9221 CurContext->addDecl(NewSpec);
9225 // Diagnose availability attributes. Availability cannot be used on functions
9226 // that are run during load/unload.
9227 if (const auto *attr = NewFD->getAttr<AvailabilityAttr>()) {
9228 if (NewFD->hasAttr<ConstructorAttr>()) {
9229 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
9231 NewFD->dropAttr<AvailabilityAttr>();
9233 if (NewFD->hasAttr<DestructorAttr>()) {
9234 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
9236 NewFD->dropAttr<AvailabilityAttr>();
9243 /// Return a CodeSegAttr from a containing class. The Microsoft docs say
9244 /// when __declspec(code_seg) "is applied to a class, all member functions of
9245 /// the class and nested classes -- this includes compiler-generated special
9246 /// member functions -- are put in the specified segment."
9247 /// The actual behavior is a little more complicated. The Microsoft compiler
9248 /// won't check outer classes if there is an active value from #pragma code_seg.
9249 /// The CodeSeg is always applied from the direct parent but only from outer
9250 /// classes when the #pragma code_seg stack is empty. See:
9251 /// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer
9252 /// available since MS has removed the page.
9253 static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) {
9254 const auto *Method = dyn_cast<CXXMethodDecl>(FD);
9257 const CXXRecordDecl *Parent = Method->getParent();
9258 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
9259 Attr *NewAttr = SAttr->clone(S.getASTContext());
9260 NewAttr->setImplicit(true);
9264 // The Microsoft compiler won't check outer classes for the CodeSeg
9265 // when the #pragma code_seg stack is active.
9266 if (S.CodeSegStack.CurrentValue)
9269 while ((Parent = dyn_cast<CXXRecordDecl>(Parent->getParent()))) {
9270 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
9271 Attr *NewAttr = SAttr->clone(S.getASTContext());
9272 NewAttr->setImplicit(true);
9279 /// Returns an implicit CodeSegAttr if a __declspec(code_seg) is found on a
9280 /// containing class. Otherwise it will return implicit SectionAttr if the
9281 /// function is a definition and there is an active value on CodeSegStack
9282 /// (from the current #pragma code-seg value).
9284 /// \param FD Function being declared.
9285 /// \param IsDefinition Whether it is a definition or just a declarartion.
9286 /// \returns A CodeSegAttr or SectionAttr to apply to the function or
9287 /// nullptr if no attribute should be added.
9288 Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
9289 bool IsDefinition) {
9290 if (Attr *A = getImplicitCodeSegAttrFromClass(*this, FD))
9292 if (!FD->hasAttr<SectionAttr>() && IsDefinition &&
9293 CodeSegStack.CurrentValue) {
9294 return SectionAttr::CreateImplicit(getASTContext(),
9295 SectionAttr::Declspec_allocate,
9296 CodeSegStack.CurrentValue->getString(),
9297 CodeSegStack.CurrentPragmaLocation);
9302 /// Determines if we can perform a correct type check for \p D as a
9303 /// redeclaration of \p PrevDecl. If not, we can generally still perform a
9304 /// best-effort check.
9306 /// \param NewD The new declaration.
9307 /// \param OldD The old declaration.
9308 /// \param NewT The portion of the type of the new declaration to check.
9309 /// \param OldT The portion of the type of the old declaration to check.
9310 bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
9311 QualType NewT, QualType OldT) {
9312 if (!NewD->getLexicalDeclContext()->isDependentContext())
9315 // For dependently-typed local extern declarations and friends, we can't
9316 // perform a correct type check in general until instantiation:
9319 // template<typename T> void g() { T f(); }
9321 // (valid if g() is only instantiated with T = int).
9322 if (NewT->isDependentType() &&
9323 (NewD->isLocalExternDecl() || NewD->getFriendObjectKind()))
9326 // Similarly, if the previous declaration was a dependent local extern
9327 // declaration, we don't really know its type yet.
9328 if (OldT->isDependentType() && OldD->isLocalExternDecl())
9334 /// Checks if the new declaration declared in dependent context must be
9335 /// put in the same redeclaration chain as the specified declaration.
9337 /// \param D Declaration that is checked.
9338 /// \param PrevDecl Previous declaration found with proper lookup method for the
9339 /// same declaration name.
9340 /// \returns True if D must be added to the redeclaration chain which PrevDecl
9343 bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) {
9344 if (!D->getLexicalDeclContext()->isDependentContext())
9347 // Don't chain dependent friend function definitions until instantiation, to
9348 // permit cases like
9351 // template<typename T> class C1 { friend void func() {} };
9352 // template<typename T> class C2 { friend void func() {} };
9354 // ... which is valid if only one of C1 and C2 is ever instantiated.
9356 // FIXME: This need only apply to function definitions. For now, we proxy
9357 // this by checking for a file-scope function. We do not want this to apply
9358 // to friend declarations nominating member functions, because that gets in
9359 // the way of access checks.
9360 if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext())
9363 auto *VD = dyn_cast<ValueDecl>(D);
9364 auto *PrevVD = dyn_cast<ValueDecl>(PrevDecl);
9365 return !VD || !PrevVD ||
9366 canFullyTypeCheckRedeclaration(VD, PrevVD, VD->getType(),
9370 /// Check the target attribute of the function for MultiVersion
9373 /// Returns true if there was an error, false otherwise.
9374 static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
9375 const auto *TA = FD->getAttr<TargetAttr>();
9376 assert(TA && "MultiVersion Candidate requires a target attribute");
9377 TargetAttr::ParsedTargetAttr ParseInfo = TA->parse();
9378 const TargetInfo &TargetInfo = S.Context.getTargetInfo();
9379 enum ErrType { Feature = 0, Architecture = 1 };
9381 if (!ParseInfo.Architecture.empty() &&
9382 !TargetInfo.validateCpuIs(ParseInfo.Architecture)) {
9383 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9384 << Architecture << ParseInfo.Architecture;
9388 for (const auto &Feat : ParseInfo.Features) {
9389 auto BareFeat = StringRef{Feat}.substr(1);
9390 if (Feat[0] == '-') {
9391 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9392 << Feature << ("no-" + BareFeat).str();
9396 if (!TargetInfo.validateCpuSupports(BareFeat) ||
9397 !TargetInfo.isValidFeatureName(BareFeat)) {
9398 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9399 << Feature << BareFeat;
9406 static bool HasNonMultiVersionAttributes(const FunctionDecl *FD,
9407 MultiVersionKind MVType) {
9408 for (const Attr *A : FD->attrs()) {
9409 switch (A->getKind()) {
9410 case attr::CPUDispatch:
9411 case attr::CPUSpecific:
9412 if (MVType != MultiVersionKind::CPUDispatch &&
9413 MVType != MultiVersionKind::CPUSpecific)
9417 if (MVType != MultiVersionKind::Target)
9427 static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD,
9428 const FunctionDecl *NewFD,
9430 MultiVersionKind MVType) {
9431 enum DoesntSupport {
9450 bool IsCPUSpecificCPUDispatchMVType =
9451 MVType == MultiVersionKind::CPUDispatch ||
9452 MVType == MultiVersionKind::CPUSpecific;
9454 if (OldFD && !OldFD->getType()->getAs<FunctionProtoType>()) {
9455 S.Diag(OldFD->getLocation(), diag::err_multiversion_noproto);
9456 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9460 if (!NewFD->getType()->getAs<FunctionProtoType>())
9461 return S.Diag(NewFD->getLocation(), diag::err_multiversion_noproto);
9463 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
9464 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
9466 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9470 // For now, disallow all other attributes. These should be opt-in, but
9471 // an analysis of all of them is a future FIXME.
9472 if (CausesMV && OldFD && HasNonMultiVersionAttributes(OldFD, MVType)) {
9473 S.Diag(OldFD->getLocation(), diag::err_multiversion_no_other_attrs)
9474 << IsCPUSpecificCPUDispatchMVType;
9475 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9479 if (HasNonMultiVersionAttributes(NewFD, MVType))
9480 return S.Diag(NewFD->getLocation(), diag::err_multiversion_no_other_attrs)
9481 << IsCPUSpecificCPUDispatchMVType;
9483 if (NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate)
9484 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9485 << IsCPUSpecificCPUDispatchMVType << FuncTemplates;
9487 if (const auto *NewCXXFD = dyn_cast<CXXMethodDecl>(NewFD)) {
9488 if (NewCXXFD->isVirtual())
9489 return S.Diag(NewCXXFD->getLocation(),
9490 diag::err_multiversion_doesnt_support)
9491 << IsCPUSpecificCPUDispatchMVType << VirtFuncs;
9493 if (const auto *NewCXXCtor = dyn_cast<CXXConstructorDecl>(NewFD))
9494 return S.Diag(NewCXXCtor->getLocation(),
9495 diag::err_multiversion_doesnt_support)
9496 << IsCPUSpecificCPUDispatchMVType << Constructors;
9498 if (const auto *NewCXXDtor = dyn_cast<CXXDestructorDecl>(NewFD))
9499 return S.Diag(NewCXXDtor->getLocation(),
9500 diag::err_multiversion_doesnt_support)
9501 << IsCPUSpecificCPUDispatchMVType << Destructors;
9504 if (NewFD->isDeleted())
9505 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9506 << IsCPUSpecificCPUDispatchMVType << DeletedFuncs;
9508 if (NewFD->isDefaulted())
9509 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9510 << IsCPUSpecificCPUDispatchMVType << DefaultedFuncs;
9512 if (NewFD->isConstexpr() && (MVType == MultiVersionKind::CPUDispatch ||
9513 MVType == MultiVersionKind::CPUSpecific))
9514 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9515 << IsCPUSpecificCPUDispatchMVType << ConstexprFuncs;
9517 QualType NewQType = S.getASTContext().getCanonicalType(NewFD->getType());
9518 const auto *NewType = cast<FunctionType>(NewQType);
9519 QualType NewReturnType = NewType->getReturnType();
9521 if (NewReturnType->isUndeducedType())
9522 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9523 << IsCPUSpecificCPUDispatchMVType << DeducedReturn;
9525 // Only allow transition to MultiVersion if it hasn't been used.
9526 if (OldFD && CausesMV && OldFD->isUsed(false))
9527 return S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used);
9529 // Ensure the return type is identical.
9531 QualType OldQType = S.getASTContext().getCanonicalType(OldFD->getType());
9532 const auto *OldType = cast<FunctionType>(OldQType);
9533 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
9534 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
9536 if (OldTypeInfo.getCC() != NewTypeInfo.getCC())
9537 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9540 QualType OldReturnType = OldType->getReturnType();
9542 if (OldReturnType != NewReturnType)
9543 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9546 if (OldFD->isConstexpr() != NewFD->isConstexpr())
9547 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9550 if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified())
9551 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9554 if (OldFD->getStorageClass() != NewFD->getStorageClass())
9555 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9558 if (OldFD->isExternC() != NewFD->isExternC())
9559 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9562 if (S.CheckEquivalentExceptionSpec(
9563 OldFD->getType()->getAs<FunctionProtoType>(), OldFD->getLocation(),
9564 NewFD->getType()->getAs<FunctionProtoType>(), NewFD->getLocation()))
9570 /// Check the validity of a multiversion function declaration that is the
9571 /// first of its kind. Also sets the multiversion'ness' of the function itself.
9573 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9575 /// Returns true if there was an error, false otherwise.
9576 static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD,
9577 MultiVersionKind MVType,
9578 const TargetAttr *TA,
9579 const CPUDispatchAttr *CPUDisp,
9580 const CPUSpecificAttr *CPUSpec) {
9581 assert(MVType != MultiVersionKind::None &&
9582 "Function lacks multiversion attribute");
9584 // Target only causes MV if it is default, otherwise this is a normal
9586 if (MVType == MultiVersionKind::Target && !TA->isDefaultVersion())
9589 if (MVType == MultiVersionKind::Target && CheckMultiVersionValue(S, FD)) {
9590 FD->setInvalidDecl();
9594 if (CheckMultiVersionAdditionalRules(S, nullptr, FD, true, MVType)) {
9595 FD->setInvalidDecl();
9599 FD->setIsMultiVersion();
9603 static bool PreviousDeclsHaveMultiVersionAttribute(const FunctionDecl *FD) {
9604 for (const Decl *D = FD->getPreviousDecl(); D; D = D->getPreviousDecl()) {
9605 if (D->getAsFunction()->getMultiVersionKind() != MultiVersionKind::None)
9612 static bool CheckTargetCausesMultiVersioning(
9613 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, const TargetAttr *NewTA,
9614 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,
9615 LookupResult &Previous) {
9616 const auto *OldTA = OldFD->getAttr<TargetAttr>();
9617 TargetAttr::ParsedTargetAttr NewParsed = NewTA->parse();
9618 // Sort order doesn't matter, it just needs to be consistent.
9619 llvm::sort(NewParsed.Features);
9621 // If the old decl is NOT MultiVersioned yet, and we don't cause that
9622 // to change, this is a simple redeclaration.
9623 if (!NewTA->isDefaultVersion() &&
9624 (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr()))
9627 // Otherwise, this decl causes MultiVersioning.
9628 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
9629 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
9630 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9631 NewFD->setInvalidDecl();
9635 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true,
9636 MultiVersionKind::Target)) {
9637 NewFD->setInvalidDecl();
9641 if (CheckMultiVersionValue(S, NewFD)) {
9642 NewFD->setInvalidDecl();
9646 // If this is 'default', permit the forward declaration.
9647 if (!OldFD->isMultiVersion() && !OldTA && NewTA->isDefaultVersion()) {
9648 Redeclaration = true;
9650 OldFD->setIsMultiVersion();
9651 NewFD->setIsMultiVersion();
9655 if (CheckMultiVersionValue(S, OldFD)) {
9656 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9657 NewFD->setInvalidDecl();
9661 TargetAttr::ParsedTargetAttr OldParsed =
9662 OldTA->parse(std::less<std::string>());
9664 if (OldParsed == NewParsed) {
9665 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
9666 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9667 NewFD->setInvalidDecl();
9671 for (const auto *FD : OldFD->redecls()) {
9672 const auto *CurTA = FD->getAttr<TargetAttr>();
9673 // We allow forward declarations before ANY multiversioning attributes, but
9674 // nothing after the fact.
9675 if (PreviousDeclsHaveMultiVersionAttribute(FD) &&
9676 (!CurTA || CurTA->isInherited())) {
9677 S.Diag(FD->getLocation(), diag::err_multiversion_required_in_redecl)
9679 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9680 NewFD->setInvalidDecl();
9685 OldFD->setIsMultiVersion();
9686 NewFD->setIsMultiVersion();
9687 Redeclaration = false;
9688 MergeTypeWithPrevious = false;
9694 /// Check the validity of a new function declaration being added to an existing
9695 /// multiversioned declaration collection.
9696 static bool CheckMultiVersionAdditionalDecl(
9697 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD,
9698 MultiVersionKind NewMVType, const TargetAttr *NewTA,
9699 const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec,
9700 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,
9701 LookupResult &Previous) {
9703 MultiVersionKind OldMVType = OldFD->getMultiVersionKind();
9704 // Disallow mixing of multiversioning types.
9705 if ((OldMVType == MultiVersionKind::Target &&
9706 NewMVType != MultiVersionKind::Target) ||
9707 (NewMVType == MultiVersionKind::Target &&
9708 OldMVType != MultiVersionKind::Target)) {
9709 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed);
9710 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9711 NewFD->setInvalidDecl();
9715 TargetAttr::ParsedTargetAttr NewParsed;
9717 NewParsed = NewTA->parse();
9718 llvm::sort(NewParsed.Features);
9721 bool UseMemberUsingDeclRules =
9722 S.CurContext->isRecord() && !NewFD->getFriendObjectKind();
9724 // Next, check ALL non-overloads to see if this is a redeclaration of a
9725 // previous member of the MultiVersion set.
9726 for (NamedDecl *ND : Previous) {
9727 FunctionDecl *CurFD = ND->getAsFunction();
9730 if (S.IsOverload(NewFD, CurFD, UseMemberUsingDeclRules))
9733 if (NewMVType == MultiVersionKind::Target) {
9734 const auto *CurTA = CurFD->getAttr<TargetAttr>();
9735 if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) {
9736 NewFD->setIsMultiVersion();
9737 Redeclaration = true;
9742 TargetAttr::ParsedTargetAttr CurParsed =
9743 CurTA->parse(std::less<std::string>());
9744 if (CurParsed == NewParsed) {
9745 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
9746 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9747 NewFD->setInvalidDecl();
9751 const auto *CurCPUSpec = CurFD->getAttr<CPUSpecificAttr>();
9752 const auto *CurCPUDisp = CurFD->getAttr<CPUDispatchAttr>();
9753 // Handle CPUDispatch/CPUSpecific versions.
9754 // Only 1 CPUDispatch function is allowed, this will make it go through
9755 // the redeclaration errors.
9756 if (NewMVType == MultiVersionKind::CPUDispatch &&
9757 CurFD->hasAttr<CPUDispatchAttr>()) {
9758 if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() &&
9760 CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(),
9761 NewCPUDisp->cpus_begin(),
9762 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
9763 return Cur->getName() == New->getName();
9765 NewFD->setIsMultiVersion();
9766 Redeclaration = true;
9771 // If the declarations don't match, this is an error condition.
9772 S.Diag(NewFD->getLocation(), diag::err_cpu_dispatch_mismatch);
9773 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9774 NewFD->setInvalidDecl();
9777 if (NewMVType == MultiVersionKind::CPUSpecific && CurCPUSpec) {
9779 if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() &&
9781 CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(),
9782 NewCPUSpec->cpus_begin(),
9783 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
9784 return Cur->getName() == New->getName();
9786 NewFD->setIsMultiVersion();
9787 Redeclaration = true;
9792 // Only 1 version of CPUSpecific is allowed for each CPU.
9793 for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) {
9794 for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) {
9795 if (CurII == NewII) {
9796 S.Diag(NewFD->getLocation(), diag::err_cpu_specific_multiple_defs)
9798 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9799 NewFD->setInvalidDecl();
9805 // If the two decls aren't the same MVType, there is no possible error
9810 // Else, this is simply a non-redecl case. Checking the 'value' is only
9811 // necessary in the Target case, since The CPUSpecific/Dispatch cases are
9812 // handled in the attribute adding step.
9813 if (NewMVType == MultiVersionKind::Target &&
9814 CheckMultiVersionValue(S, NewFD)) {
9815 NewFD->setInvalidDecl();
9819 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD,
9820 !OldFD->isMultiVersion(), NewMVType)) {
9821 NewFD->setInvalidDecl();
9825 // Permit forward declarations in the case where these two are compatible.
9826 if (!OldFD->isMultiVersion()) {
9827 OldFD->setIsMultiVersion();
9828 NewFD->setIsMultiVersion();
9829 Redeclaration = true;
9834 NewFD->setIsMultiVersion();
9835 Redeclaration = false;
9836 MergeTypeWithPrevious = false;
9843 /// Check the validity of a mulitversion function declaration.
9844 /// Also sets the multiversion'ness' of the function itself.
9846 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9848 /// Returns true if there was an error, false otherwise.
9849 static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD,
9850 bool &Redeclaration, NamedDecl *&OldDecl,
9851 bool &MergeTypeWithPrevious,
9852 LookupResult &Previous) {
9853 const auto *NewTA = NewFD->getAttr<TargetAttr>();
9854 const auto *NewCPUDisp = NewFD->getAttr<CPUDispatchAttr>();
9855 const auto *NewCPUSpec = NewFD->getAttr<CPUSpecificAttr>();
9857 // Mixing Multiversioning types is prohibited.
9858 if ((NewTA && NewCPUDisp) || (NewTA && NewCPUSpec) ||
9859 (NewCPUDisp && NewCPUSpec)) {
9860 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed);
9861 NewFD->setInvalidDecl();
9865 MultiVersionKind MVType = NewFD->getMultiVersionKind();
9867 // Main isn't allowed to become a multiversion function, however it IS
9868 // permitted to have 'main' be marked with the 'target' optimization hint.
9869 if (NewFD->isMain()) {
9870 if ((MVType == MultiVersionKind::Target && NewTA->isDefaultVersion()) ||
9871 MVType == MultiVersionKind::CPUDispatch ||
9872 MVType == MultiVersionKind::CPUSpecific) {
9873 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_allowed_on_main);
9874 NewFD->setInvalidDecl();
9880 if (!OldDecl || !OldDecl->getAsFunction() ||
9881 OldDecl->getDeclContext()->getRedeclContext() !=
9882 NewFD->getDeclContext()->getRedeclContext()) {
9883 // If there's no previous declaration, AND this isn't attempting to cause
9884 // multiversioning, this isn't an error condition.
9885 if (MVType == MultiVersionKind::None)
9887 return CheckMultiVersionFirstFunction(S, NewFD, MVType, NewTA, NewCPUDisp,
9891 FunctionDecl *OldFD = OldDecl->getAsFunction();
9893 if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::None)
9896 if (OldFD->isMultiVersion() && MVType == MultiVersionKind::None) {
9897 S.Diag(NewFD->getLocation(), diag::err_multiversion_required_in_redecl)
9898 << (OldFD->getMultiVersionKind() != MultiVersionKind::Target);
9899 NewFD->setInvalidDecl();
9903 // Handle the target potentially causes multiversioning case.
9904 if (!OldFD->isMultiVersion() && MVType == MultiVersionKind::Target)
9905 return CheckTargetCausesMultiVersioning(S, OldFD, NewFD, NewTA,
9906 Redeclaration, OldDecl,
9907 MergeTypeWithPrevious, Previous);
9909 // At this point, we have a multiversion function decl (in OldFD) AND an
9910 // appropriate attribute in the current function decl. Resolve that these are
9911 // still compatible with previous declarations.
9912 return CheckMultiVersionAdditionalDecl(
9913 S, OldFD, NewFD, MVType, NewTA, NewCPUDisp, NewCPUSpec, Redeclaration,
9914 OldDecl, MergeTypeWithPrevious, Previous);
9917 /// Perform semantic checking of a new function declaration.
9919 /// Performs semantic analysis of the new function declaration
9920 /// NewFD. This routine performs all semantic checking that does not
9921 /// require the actual declarator involved in the declaration, and is
9922 /// used both for the declaration of functions as they are parsed
9923 /// (called via ActOnDeclarator) and for the declaration of functions
9924 /// that have been instantiated via C++ template instantiation (called
9925 /// via InstantiateDecl).
9927 /// \param IsMemberSpecialization whether this new function declaration is
9928 /// a member specialization (that replaces any definition provided by the
9929 /// previous declaration).
9931 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9933 /// \returns true if the function declaration is a redeclaration.
9934 bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
9935 LookupResult &Previous,
9936 bool IsMemberSpecialization) {
9937 assert(!NewFD->getReturnType()->isVariablyModifiedType() &&
9938 "Variably modified return types are not handled here");
9940 // Determine whether the type of this function should be merged with
9941 // a previous visible declaration. This never happens for functions in C++,
9942 // and always happens in C if the previous declaration was visible.
9943 bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus &&
9944 !Previous.isShadowed();
9946 bool Redeclaration = false;
9947 NamedDecl *OldDecl = nullptr;
9948 bool MayNeedOverloadableChecks = false;
9950 // Merge or overload the declaration with an existing declaration of
9951 // the same name, if appropriate.
9952 if (!Previous.empty()) {
9953 // Determine whether NewFD is an overload of PrevDecl or
9954 // a declaration that requires merging. If it's an overload,
9955 // there's no more work to do here; we'll just add the new
9956 // function to the scope.
9957 if (!AllowOverloadingOfFunction(Previous, Context, NewFD)) {
9958 NamedDecl *Candidate = Previous.getRepresentativeDecl();
9959 if (shouldLinkPossiblyHiddenDecl(Candidate, NewFD)) {
9960 Redeclaration = true;
9961 OldDecl = Candidate;
9964 MayNeedOverloadableChecks = true;
9965 switch (CheckOverload(S, NewFD, Previous, OldDecl,
9966 /*NewIsUsingDecl*/ false)) {
9968 Redeclaration = true;
9971 case Ovl_NonFunction:
9972 Redeclaration = true;
9976 Redeclaration = false;
9982 // Check for a previous extern "C" declaration with this name.
9983 if (!Redeclaration &&
9984 checkForConflictWithNonVisibleExternC(*this, NewFD, Previous)) {
9985 if (!Previous.empty()) {
9986 // This is an extern "C" declaration with the same name as a previous
9987 // declaration, and thus redeclares that entity...
9988 Redeclaration = true;
9989 OldDecl = Previous.getFoundDecl();
9990 MergeTypeWithPrevious = false;
9992 // ... except in the presence of __attribute__((overloadable)).
9993 if (OldDecl->hasAttr<OverloadableAttr>() ||
9994 NewFD->hasAttr<OverloadableAttr>()) {
9995 if (IsOverload(NewFD, cast<FunctionDecl>(OldDecl), false)) {
9996 MayNeedOverloadableChecks = true;
9997 Redeclaration = false;
10004 if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl,
10005 MergeTypeWithPrevious, Previous))
10006 return Redeclaration;
10008 // C++11 [dcl.constexpr]p8:
10009 // A constexpr specifier for a non-static member function that is not
10010 // a constructor declares that member function to be const.
10012 // This needs to be delayed until we know whether this is an out-of-line
10013 // definition of a static member function.
10015 // This rule is not present in C++1y, so we produce a backwards
10016 // compatibility warning whenever it happens in C++11.
10017 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
10018 if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() &&
10019 !MD->isStatic() && !isa<CXXConstructorDecl>(MD) &&
10020 !MD->getTypeQualifiers().hasConst()) {
10021 CXXMethodDecl *OldMD = nullptr;
10023 OldMD = dyn_cast_or_null<CXXMethodDecl>(OldDecl->getAsFunction());
10024 if (!OldMD || !OldMD->isStatic()) {
10025 const FunctionProtoType *FPT =
10026 MD->getType()->castAs<FunctionProtoType>();
10027 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
10028 EPI.TypeQuals.addConst();
10029 MD->setType(Context.getFunctionType(FPT->getReturnType(),
10030 FPT->getParamTypes(), EPI));
10032 // Warn that we did this, if we're not performing template instantiation.
10033 // In that case, we'll have warned already when the template was defined.
10034 if (!inTemplateInstantiation()) {
10035 SourceLocation AddConstLoc;
10036 if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc()
10037 .IgnoreParens().getAs<FunctionTypeLoc>())
10038 AddConstLoc = getLocForEndOfToken(FTL.getRParenLoc());
10040 Diag(MD->getLocation(), diag::warn_cxx14_compat_constexpr_not_const)
10041 << FixItHint::CreateInsertion(AddConstLoc, " const");
10046 if (Redeclaration) {
10047 // NewFD and OldDecl represent declarations that need to be
10049 if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious)) {
10050 NewFD->setInvalidDecl();
10051 return Redeclaration;
10055 Previous.addDecl(OldDecl);
10057 if (FunctionTemplateDecl *OldTemplateDecl =
10058 dyn_cast<FunctionTemplateDecl>(OldDecl)) {
10059 auto *OldFD = OldTemplateDecl->getTemplatedDecl();
10060 FunctionTemplateDecl *NewTemplateDecl
10061 = NewFD->getDescribedFunctionTemplate();
10062 assert(NewTemplateDecl && "Template/non-template mismatch");
10064 // The call to MergeFunctionDecl above may have created some state in
10065 // NewTemplateDecl that needs to be merged with OldTemplateDecl before we
10066 // can add it as a redeclaration.
10067 NewTemplateDecl->mergePrevDecl(OldTemplateDecl);
10069 NewFD->setPreviousDeclaration(OldFD);
10070 adjustDeclContextForDeclaratorDecl(NewFD, OldFD);
10071 if (NewFD->isCXXClassMember()) {
10072 NewFD->setAccess(OldTemplateDecl->getAccess());
10073 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess());
10076 // If this is an explicit specialization of a member that is a function
10077 // template, mark it as a member specialization.
10078 if (IsMemberSpecialization &&
10079 NewTemplateDecl->getInstantiatedFromMemberTemplate()) {
10080 NewTemplateDecl->setMemberSpecialization();
10081 assert(OldTemplateDecl->isMemberSpecialization());
10082 // Explicit specializations of a member template do not inherit deleted
10083 // status from the parent member template that they are specializing.
10084 if (OldFD->isDeleted()) {
10085 // FIXME: This assert will not hold in the presence of modules.
10086 assert(OldFD->getCanonicalDecl() == OldFD);
10087 // FIXME: We need an update record for this AST mutation.
10088 OldFD->setDeletedAsWritten(false);
10093 if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) {
10094 auto *OldFD = cast<FunctionDecl>(OldDecl);
10095 // This needs to happen first so that 'inline' propagates.
10096 NewFD->setPreviousDeclaration(OldFD);
10097 adjustDeclContextForDeclaratorDecl(NewFD, OldFD);
10098 if (NewFD->isCXXClassMember())
10099 NewFD->setAccess(OldFD->getAccess());
10102 } else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks &&
10103 !NewFD->getAttr<OverloadableAttr>()) {
10104 assert((Previous.empty() ||
10105 llvm::any_of(Previous,
10106 [](const NamedDecl *ND) {
10107 return ND->hasAttr<OverloadableAttr>();
10109 "Non-redecls shouldn't happen without overloadable present");
10111 auto OtherUnmarkedIter = llvm::find_if(Previous, [](const NamedDecl *ND) {
10112 const auto *FD = dyn_cast<FunctionDecl>(ND);
10113 return FD && !FD->hasAttr<OverloadableAttr>();
10116 if (OtherUnmarkedIter != Previous.end()) {
10117 Diag(NewFD->getLocation(),
10118 diag::err_attribute_overloadable_multiple_unmarked_overloads);
10119 Diag((*OtherUnmarkedIter)->getLocation(),
10120 diag::note_attribute_overloadable_prev_overload)
10123 NewFD->addAttr(OverloadableAttr::CreateImplicit(Context));
10127 // Semantic checking for this function declaration (in isolation).
10129 if (getLangOpts().CPlusPlus) {
10130 // C++-specific checks.
10131 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) {
10132 CheckConstructor(Constructor);
10133 } else if (CXXDestructorDecl *Destructor =
10134 dyn_cast<CXXDestructorDecl>(NewFD)) {
10135 CXXRecordDecl *Record = Destructor->getParent();
10136 QualType ClassType = Context.getTypeDeclType(Record);
10138 // FIXME: Shouldn't we be able to perform this check even when the class
10139 // type is dependent? Both gcc and edg can handle that.
10140 if (!ClassType->isDependentType()) {
10141 DeclarationName Name
10142 = Context.DeclarationNames.getCXXDestructorName(
10143 Context.getCanonicalType(ClassType));
10144 if (NewFD->getDeclName() != Name) {
10145 Diag(NewFD->getLocation(), diag::err_destructor_name);
10146 NewFD->setInvalidDecl();
10147 return Redeclaration;
10150 } else if (CXXConversionDecl *Conversion
10151 = dyn_cast<CXXConversionDecl>(NewFD)) {
10152 ActOnConversionDeclarator(Conversion);
10153 } else if (auto *Guide = dyn_cast<CXXDeductionGuideDecl>(NewFD)) {
10154 if (auto *TD = Guide->getDescribedFunctionTemplate())
10155 CheckDeductionGuideTemplate(TD);
10157 // A deduction guide is not on the list of entities that can be
10158 // explicitly specialized.
10159 if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
10160 Diag(Guide->getBeginLoc(), diag::err_deduction_guide_specialized)
10161 << /*explicit specialization*/ 1;
10164 // Find any virtual functions that this function overrides.
10165 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) {
10166 if (!Method->isFunctionTemplateSpecialization() &&
10167 !Method->getDescribedFunctionTemplate() &&
10168 Method->isCanonicalDecl()) {
10169 if (AddOverriddenMethods(Method->getParent(), Method)) {
10170 // If the function was marked as "static", we have a problem.
10171 if (NewFD->getStorageClass() == SC_Static) {
10172 ReportOverrides(*this, diag::err_static_overrides_virtual, Method);
10177 if (Method->isStatic())
10178 checkThisInStaticMemberFunctionType(Method);
10181 // Extra checking for C++ overloaded operators (C++ [over.oper]).
10182 if (NewFD->isOverloadedOperator() &&
10183 CheckOverloadedOperatorDeclaration(NewFD)) {
10184 NewFD->setInvalidDecl();
10185 return Redeclaration;
10188 // Extra checking for C++0x literal operators (C++0x [over.literal]).
10189 if (NewFD->getLiteralIdentifier() &&
10190 CheckLiteralOperatorDeclaration(NewFD)) {
10191 NewFD->setInvalidDecl();
10192 return Redeclaration;
10195 // In C++, check default arguments now that we have merged decls. Unless
10196 // the lexical context is the class, because in this case this is done
10197 // during delayed parsing anyway.
10198 if (!CurContext->isRecord())
10199 CheckCXXDefaultArguments(NewFD);
10201 // If this function declares a builtin function, check the type of this
10202 // declaration against the expected type for the builtin.
10203 if (unsigned BuiltinID = NewFD->getBuiltinID()) {
10204 ASTContext::GetBuiltinTypeError Error;
10205 LookupPredefedObjCSuperType(*this, S, NewFD->getIdentifier());
10206 QualType T = Context.GetBuiltinType(BuiltinID, Error);
10207 // If the type of the builtin differs only in its exception
10208 // specification, that's OK.
10209 // FIXME: If the types do differ in this way, it would be better to
10210 // retain the 'noexcept' form of the type.
10212 !Context.hasSameFunctionTypeIgnoringExceptionSpec(T,
10214 // The type of this function differs from the type of the builtin,
10215 // so forget about the builtin entirely.
10216 Context.BuiltinInfo.forgetBuiltin(BuiltinID, Context.Idents);
10219 // If this function is declared as being extern "C", then check to see if
10220 // the function returns a UDT (class, struct, or union type) that is not C
10221 // compatible, and if it does, warn the user.
10222 // But, issue any diagnostic on the first declaration only.
10223 if (Previous.empty() && NewFD->isExternC()) {
10224 QualType R = NewFD->getReturnType();
10225 if (R->isIncompleteType() && !R->isVoidType())
10226 Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete)
10228 else if (!R.isPODType(Context) && !R->isVoidType() &&
10229 !R->isObjCObjectPointerType())
10230 Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R;
10233 // C++1z [dcl.fct]p6:
10234 // [...] whether the function has a non-throwing exception-specification
10235 // [is] part of the function type
10237 // This results in an ABI break between C++14 and C++17 for functions whose
10238 // declared type includes an exception-specification in a parameter or
10239 // return type. (Exception specifications on the function itself are OK in
10240 // most cases, and exception specifications are not permitted in most other
10241 // contexts where they could make it into a mangling.)
10242 if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) {
10243 auto HasNoexcept = [&](QualType T) -> bool {
10244 // Strip off declarator chunks that could be between us and a function
10245 // type. We don't need to look far, exception specifications are very
10246 // restricted prior to C++17.
10247 if (auto *RT = T->getAs<ReferenceType>())
10248 T = RT->getPointeeType();
10249 else if (T->isAnyPointerType())
10250 T = T->getPointeeType();
10251 else if (auto *MPT = T->getAs<MemberPointerType>())
10252 T = MPT->getPointeeType();
10253 if (auto *FPT = T->getAs<FunctionProtoType>())
10254 if (FPT->isNothrow())
10259 auto *FPT = NewFD->getType()->castAs<FunctionProtoType>();
10260 bool AnyNoexcept = HasNoexcept(FPT->getReturnType());
10261 for (QualType T : FPT->param_types())
10262 AnyNoexcept |= HasNoexcept(T);
10264 Diag(NewFD->getLocation(),
10265 diag::warn_cxx17_compat_exception_spec_in_signature)
10269 if (!Redeclaration && LangOpts.CUDA)
10270 checkCUDATargetOverload(NewFD, Previous);
10272 return Redeclaration;
10275 void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) {
10276 // C++11 [basic.start.main]p3:
10277 // A program that [...] declares main to be inline, static or
10278 // constexpr is ill-formed.
10279 // C11 6.7.4p4: In a hosted environment, no function specifier(s) shall
10280 // appear in a declaration of main.
10281 // static main is not an error under C99, but we should warn about it.
10282 // We accept _Noreturn main as an extension.
10283 if (FD->getStorageClass() == SC_Static)
10284 Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus
10285 ? diag::err_static_main : diag::warn_static_main)
10286 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
10287 if (FD->isInlineSpecified())
10288 Diag(DS.getInlineSpecLoc(), diag::err_inline_main)
10289 << FixItHint::CreateRemoval(DS.getInlineSpecLoc());
10290 if (DS.isNoreturnSpecified()) {
10291 SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc();
10292 SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(NoreturnLoc));
10293 Diag(NoreturnLoc, diag::ext_noreturn_main);
10294 Diag(NoreturnLoc, diag::note_main_remove_noreturn)
10295 << FixItHint::CreateRemoval(NoreturnRange);
10297 if (FD->isConstexpr()) {
10298 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main)
10299 << FixItHint::CreateRemoval(DS.getConstexprSpecLoc());
10300 FD->setConstexpr(false);
10303 if (getLangOpts().OpenCL) {
10304 Diag(FD->getLocation(), diag::err_opencl_no_main)
10305 << FD->hasAttr<OpenCLKernelAttr>();
10306 FD->setInvalidDecl();
10310 QualType T = FD->getType();
10311 assert(T->isFunctionType() && "function decl is not of function type");
10312 const FunctionType* FT = T->castAs<FunctionType>();
10314 // Set default calling convention for main()
10315 if (FT->getCallConv() != CC_C) {
10316 FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(CC_C));
10317 FD->setType(QualType(FT, 0));
10318 T = Context.getCanonicalType(FD->getType());
10321 if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) {
10322 // In C with GNU extensions we allow main() to have non-integer return
10323 // type, but we should warn about the extension, and we disable the
10324 // implicit-return-zero rule.
10326 // GCC in C mode accepts qualified 'int'.
10327 if (Context.hasSameUnqualifiedType(FT->getReturnType(), Context.IntTy))
10328 FD->setHasImplicitReturnZero(true);
10330 Diag(FD->getTypeSpecStartLoc(), diag::ext_main_returns_nonint);
10331 SourceRange RTRange = FD->getReturnTypeSourceRange();
10332 if (RTRange.isValid())
10333 Diag(RTRange.getBegin(), diag::note_main_change_return_type)
10334 << FixItHint::CreateReplacement(RTRange, "int");
10337 // In C and C++, main magically returns 0 if you fall off the end;
10338 // set the flag which tells us that.
10339 // This is C++ [basic.start.main]p5 and C99 5.1.2.2.3.
10341 // All the standards say that main() should return 'int'.
10342 if (Context.hasSameType(FT->getReturnType(), Context.IntTy))
10343 FD->setHasImplicitReturnZero(true);
10345 // Otherwise, this is just a flat-out error.
10346 SourceRange RTRange = FD->getReturnTypeSourceRange();
10347 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint)
10348 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "int")
10350 FD->setInvalidDecl(true);
10354 // Treat protoless main() as nullary.
10355 if (isa<FunctionNoProtoType>(FT)) return;
10357 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT);
10358 unsigned nparams = FTP->getNumParams();
10359 assert(FD->getNumParams() == nparams);
10361 bool HasExtraParameters = (nparams > 3);
10363 if (FTP->isVariadic()) {
10364 Diag(FD->getLocation(), diag::ext_variadic_main);
10365 // FIXME: if we had information about the location of the ellipsis, we
10366 // could add a FixIt hint to remove it as a parameter.
10369 // Darwin passes an undocumented fourth argument of type char**. If
10370 // other platforms start sprouting these, the logic below will start
10372 if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin())
10373 HasExtraParameters = false;
10375 if (HasExtraParameters) {
10376 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams;
10377 FD->setInvalidDecl(true);
10381 // FIXME: a lot of the following diagnostics would be improved
10382 // if we had some location information about types.
10385 Context.getPointerType(Context.getPointerType(Context.CharTy));
10386 QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP };
10388 for (unsigned i = 0; i < nparams; ++i) {
10389 QualType AT = FTP->getParamType(i);
10391 bool mismatch = true;
10393 if (Context.hasSameUnqualifiedType(AT, Expected[i]))
10395 else if (Expected[i] == CharPP) {
10396 // As an extension, the following forms are okay:
10398 // char const * const *
10401 QualifierCollector qs;
10402 const PointerType* PT;
10403 if ((PT = qs.strip(AT)->getAs<PointerType>()) &&
10404 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) &&
10405 Context.hasSameType(QualType(qs.strip(PT->getPointeeType()), 0),
10408 mismatch = !qs.empty();
10413 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i];
10414 // TODO: suggest replacing given type with expected type
10415 FD->setInvalidDecl(true);
10419 if (nparams == 1 && !FD->isInvalidDecl()) {
10420 Diag(FD->getLocation(), diag::warn_main_one_arg);
10423 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
10424 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
10425 FD->setInvalidDecl();
10429 void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) {
10430 QualType T = FD->getType();
10431 assert(T->isFunctionType() && "function decl is not of function type");
10432 const FunctionType *FT = T->castAs<FunctionType>();
10434 // Set an implicit return of 'zero' if the function can return some integral,
10435 // enumeration, pointer or nullptr type.
10436 if (FT->getReturnType()->isIntegralOrEnumerationType() ||
10437 FT->getReturnType()->isAnyPointerType() ||
10438 FT->getReturnType()->isNullPtrType())
10439 // DllMain is exempt because a return value of zero means it failed.
10440 if (FD->getName() != "DllMain")
10441 FD->setHasImplicitReturnZero(true);
10443 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
10444 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
10445 FD->setInvalidDecl();
10449 bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
10450 // FIXME: Need strict checking. In C89, we need to check for
10451 // any assignment, increment, decrement, function-calls, or
10452 // commas outside of a sizeof. In C99, it's the same list,
10453 // except that the aforementioned are allowed in unevaluated
10454 // expressions. Everything else falls under the
10455 // "may accept other forms of constant expressions" exception.
10456 // (We never end up here for C++, so the constant expression
10457 // rules there don't matter.)
10458 const Expr *Culprit;
10459 if (Init->isConstantInitializer(Context, false, &Culprit))
10461 Diag(Culprit->getExprLoc(), diag::err_init_element_not_constant)
10462 << Culprit->getSourceRange();
10467 // Visits an initialization expression to see if OrigDecl is evaluated in
10468 // its own initialization and throws a warning if it does.
10469 class SelfReferenceChecker
10470 : public EvaluatedExprVisitor<SelfReferenceChecker> {
10475 bool isReferenceType;
10478 llvm::SmallVector<unsigned, 4> InitFieldIndex;
10481 typedef EvaluatedExprVisitor<SelfReferenceChecker> Inherited;
10483 SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context),
10484 S(S), OrigDecl(OrigDecl) {
10486 isRecordType = false;
10487 isReferenceType = false;
10488 isInitList = false;
10489 if (ValueDecl *VD = dyn_cast<ValueDecl>(OrigDecl)) {
10490 isPODType = VD->getType().isPODType(S.Context);
10491 isRecordType = VD->getType()->isRecordType();
10492 isReferenceType = VD->getType()->isReferenceType();
10496 // For most expressions, just call the visitor. For initializer lists,
10497 // track the index of the field being initialized since fields are
10498 // initialized in order allowing use of previously initialized fields.
10499 void CheckExpr(Expr *E) {
10500 InitListExpr *InitList = dyn_cast<InitListExpr>(E);
10506 // Track and increment the index here.
10508 InitFieldIndex.push_back(0);
10509 for (auto Child : InitList->children()) {
10510 CheckExpr(cast<Expr>(Child));
10511 ++InitFieldIndex.back();
10513 InitFieldIndex.pop_back();
10516 // Returns true if MemberExpr is checked and no further checking is needed.
10517 // Returns false if additional checking is required.
10518 bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) {
10519 llvm::SmallVector<FieldDecl*, 4> Fields;
10521 bool ReferenceField = false;
10523 // Get the field members used.
10524 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10525 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
10528 Fields.push_back(FD);
10529 if (FD->getType()->isReferenceType())
10530 ReferenceField = true;
10531 Base = ME->getBase()->IgnoreParenImpCasts();
10534 // Keep checking only if the base Decl is the same.
10535 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base);
10536 if (!DRE || DRE->getDecl() != OrigDecl)
10539 // A reference field can be bound to an unininitialized field.
10540 if (CheckReference && !ReferenceField)
10543 // Convert FieldDecls to their index number.
10544 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
10545 for (const FieldDecl *I : llvm::reverse(Fields))
10546 UsedFieldIndex.push_back(I->getFieldIndex());
10548 // See if a warning is needed by checking the first difference in index
10549 // numbers. If field being used has index less than the field being
10550 // initialized, then the use is safe.
10551 for (auto UsedIter = UsedFieldIndex.begin(),
10552 UsedEnd = UsedFieldIndex.end(),
10553 OrigIter = InitFieldIndex.begin(),
10554 OrigEnd = InitFieldIndex.end();
10555 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
10556 if (*UsedIter < *OrigIter)
10558 if (*UsedIter > *OrigIter)
10562 // TODO: Add a different warning which will print the field names.
10563 HandleDeclRefExpr(DRE);
10567 // For most expressions, the cast is directly above the DeclRefExpr.
10568 // For conditional operators, the cast can be outside the conditional
10569 // operator if both expressions are DeclRefExpr's.
10570 void HandleValue(Expr *E) {
10571 E = E->IgnoreParens();
10572 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(E)) {
10573 HandleDeclRefExpr(DRE);
10577 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
10578 Visit(CO->getCond());
10579 HandleValue(CO->getTrueExpr());
10580 HandleValue(CO->getFalseExpr());
10584 if (BinaryConditionalOperator *BCO =
10585 dyn_cast<BinaryConditionalOperator>(E)) {
10586 Visit(BCO->getCond());
10587 HandleValue(BCO->getFalseExpr());
10591 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
10592 HandleValue(OVE->getSourceExpr());
10596 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
10597 if (BO->getOpcode() == BO_Comma) {
10598 Visit(BO->getLHS());
10599 HandleValue(BO->getRHS());
10604 if (isa<MemberExpr>(E)) {
10606 if (CheckInitListMemberExpr(cast<MemberExpr>(E),
10607 false /*CheckReference*/))
10611 Expr *Base = E->IgnoreParenImpCasts();
10612 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10613 // Check for static member variables and don't warn on them.
10614 if (!isa<FieldDecl>(ME->getMemberDecl()))
10616 Base = ME->getBase()->IgnoreParenImpCasts();
10618 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base))
10619 HandleDeclRefExpr(DRE);
10626 // Reference types not handled in HandleValue are handled here since all
10627 // uses of references are bad, not just r-value uses.
10628 void VisitDeclRefExpr(DeclRefExpr *E) {
10629 if (isReferenceType)
10630 HandleDeclRefExpr(E);
10633 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
10634 if (E->getCastKind() == CK_LValueToRValue) {
10635 HandleValue(E->getSubExpr());
10639 Inherited::VisitImplicitCastExpr(E);
10642 void VisitMemberExpr(MemberExpr *E) {
10644 if (CheckInitListMemberExpr(E, true /*CheckReference*/))
10648 // Don't warn on arrays since they can be treated as pointers.
10649 if (E->getType()->canDecayToPointerType()) return;
10651 // Warn when a non-static method call is followed by non-static member
10652 // field accesses, which is followed by a DeclRefExpr.
10653 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl());
10654 bool Warn = (MD && !MD->isStatic());
10655 Expr *Base = E->getBase()->IgnoreParenImpCasts();
10656 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10657 if (!isa<FieldDecl>(ME->getMemberDecl()))
10659 Base = ME->getBase()->IgnoreParenImpCasts();
10662 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) {
10664 HandleDeclRefExpr(DRE);
10668 // The base of a MemberExpr is not a MemberExpr or a DeclRefExpr.
10669 // Visit that expression.
10673 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
10674 Expr *Callee = E->getCallee();
10676 if (isa<UnresolvedLookupExpr>(Callee))
10677 return Inherited::VisitCXXOperatorCallExpr(E);
10680 for (auto Arg: E->arguments())
10681 HandleValue(Arg->IgnoreParenImpCasts());
10684 void VisitUnaryOperator(UnaryOperator *E) {
10685 // For POD record types, addresses of its own members are well-defined.
10686 if (E->getOpcode() == UO_AddrOf && isRecordType &&
10687 isa<MemberExpr>(E->getSubExpr()->IgnoreParens())) {
10689 HandleValue(E->getSubExpr());
10693 if (E->isIncrementDecrementOp()) {
10694 HandleValue(E->getSubExpr());
10698 Inherited::VisitUnaryOperator(E);
10701 void VisitObjCMessageExpr(ObjCMessageExpr *E) {}
10703 void VisitCXXConstructExpr(CXXConstructExpr *E) {
10704 if (E->getConstructor()->isCopyConstructor()) {
10705 Expr *ArgExpr = E->getArg(0);
10706 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
10707 if (ILE->getNumInits() == 1)
10708 ArgExpr = ILE->getInit(0);
10709 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
10710 if (ICE->getCastKind() == CK_NoOp)
10711 ArgExpr = ICE->getSubExpr();
10712 HandleValue(ArgExpr);
10715 Inherited::VisitCXXConstructExpr(E);
10718 void VisitCallExpr(CallExpr *E) {
10719 // Treat std::move as a use.
10720 if (E->isCallToStdMove()) {
10721 HandleValue(E->getArg(0));
10725 Inherited::VisitCallExpr(E);
10728 void VisitBinaryOperator(BinaryOperator *E) {
10729 if (E->isCompoundAssignmentOp()) {
10730 HandleValue(E->getLHS());
10731 Visit(E->getRHS());
10735 Inherited::VisitBinaryOperator(E);
10738 // A custom visitor for BinaryConditionalOperator is needed because the
10739 // regular visitor would check the condition and true expression separately
10740 // but both point to the same place giving duplicate diagnostics.
10741 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
10742 Visit(E->getCond());
10743 Visit(E->getFalseExpr());
10746 void HandleDeclRefExpr(DeclRefExpr *DRE) {
10747 Decl* ReferenceDecl = DRE->getDecl();
10748 if (OrigDecl != ReferenceDecl) return;
10750 if (isReferenceType) {
10751 diag = diag::warn_uninit_self_reference_in_reference_init;
10752 } else if (cast<VarDecl>(OrigDecl)->isStaticLocal()) {
10753 diag = diag::warn_static_self_reference_in_init;
10754 } else if (isa<TranslationUnitDecl>(OrigDecl->getDeclContext()) ||
10755 isa<NamespaceDecl>(OrigDecl->getDeclContext()) ||
10756 DRE->getDecl()->getType()->isRecordType()) {
10757 diag = diag::warn_uninit_self_reference_in_init;
10759 // Local variables will be handled by the CFG analysis.
10763 S.DiagRuntimeBehavior(DRE->getBeginLoc(), DRE,
10765 << DRE->getDecl() << OrigDecl->getLocation()
10766 << DRE->getSourceRange());
10770 /// CheckSelfReference - Warns if OrigDecl is used in expression E.
10771 static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E,
10773 // Parameters arguments are occassionially constructed with itself,
10774 // for instance, in recursive functions. Skip them.
10775 if (isa<ParmVarDecl>(OrigDecl))
10778 E = E->IgnoreParens();
10780 // Skip checking T a = a where T is not a record or reference type.
10781 // Doing so is a way to silence uninitialized warnings.
10782 if (!DirectInit && !cast<VarDecl>(OrigDecl)->getType()->isRecordType())
10783 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
10784 if (ICE->getCastKind() == CK_LValueToRValue)
10785 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr()))
10786 if (DRE->getDecl() == OrigDecl)
10789 SelfReferenceChecker(S, OrigDecl).CheckExpr(E);
10791 } // end anonymous namespace
10794 // Simple wrapper to add the name of a variable or (if no variable is
10795 // available) a DeclarationName into a diagnostic.
10796 struct VarDeclOrName {
10798 DeclarationName Name;
10800 friend const Sema::SemaDiagnosticBuilder &
10801 operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) {
10802 return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name;
10805 } // end anonymous namespace
10807 QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl,
10808 DeclarationName Name, QualType Type,
10809 TypeSourceInfo *TSI,
10810 SourceRange Range, bool DirectInit,
10812 bool IsInitCapture = !VDecl;
10813 assert((!VDecl || !VDecl->isInitCapture()) &&
10814 "init captures are expected to be deduced prior to initialization");
10816 VarDeclOrName VN{VDecl, Name};
10818 DeducedType *Deduced = Type->getContainedDeducedType();
10819 assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type");
10821 // C++11 [dcl.spec.auto]p3
10823 assert(VDecl && "no init for init capture deduction?");
10825 // Except for class argument deduction, and then for an initializing
10826 // declaration only, i.e. no static at class scope or extern.
10827 if (!isa<DeducedTemplateSpecializationType>(Deduced) ||
10828 VDecl->hasExternalStorage() ||
10829 VDecl->isStaticDataMember()) {
10830 Diag(VDecl->getLocation(), diag::err_auto_var_requires_init)
10831 << VDecl->getDeclName() << Type;
10836 ArrayRef<Expr*> DeduceInits;
10838 DeduceInits = Init;
10841 if (auto *PL = dyn_cast_or_null<ParenListExpr>(Init))
10842 DeduceInits = PL->exprs();
10845 if (isa<DeducedTemplateSpecializationType>(Deduced)) {
10846 assert(VDecl && "non-auto type for init capture deduction?");
10847 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
10848 InitializationKind Kind = InitializationKind::CreateForInit(
10849 VDecl->getLocation(), DirectInit, Init);
10850 // FIXME: Initialization should not be taking a mutable list of inits.
10851 SmallVector<Expr*, 8> InitsCopy(DeduceInits.begin(), DeduceInits.end());
10852 return DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind,
10857 if (auto *IL = dyn_cast<InitListExpr>(Init))
10858 DeduceInits = IL->inits();
10861 // Deduction only works if we have exactly one source expression.
10862 if (DeduceInits.empty()) {
10863 // It isn't possible to write this directly, but it is possible to
10864 // end up in this situation with "auto x(some_pack...);"
10865 Diag(Init->getBeginLoc(), IsInitCapture
10866 ? diag::err_init_capture_no_expression
10867 : diag::err_auto_var_init_no_expression)
10868 << VN << Type << Range;
10872 if (DeduceInits.size() > 1) {
10873 Diag(DeduceInits[1]->getBeginLoc(),
10874 IsInitCapture ? diag::err_init_capture_multiple_expressions
10875 : diag::err_auto_var_init_multiple_expressions)
10876 << VN << Type << Range;
10880 Expr *DeduceInit = DeduceInits[0];
10881 if (DirectInit && isa<InitListExpr>(DeduceInit)) {
10882 Diag(Init->getBeginLoc(), IsInitCapture
10883 ? diag::err_init_capture_paren_braces
10884 : diag::err_auto_var_init_paren_braces)
10885 << isa<InitListExpr>(Init) << VN << Type << Range;
10889 // Expressions default to 'id' when we're in a debugger.
10890 bool DefaultedAnyToId = false;
10891 if (getLangOpts().DebuggerCastResultToId &&
10892 Init->getType() == Context.UnknownAnyTy && !IsInitCapture) {
10893 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
10894 if (Result.isInvalid()) {
10897 Init = Result.get();
10898 DefaultedAnyToId = true;
10901 // C++ [dcl.decomp]p1:
10902 // If the assignment-expression [...] has array type A and no ref-qualifier
10903 // is present, e has type cv A
10904 if (VDecl && isa<DecompositionDecl>(VDecl) &&
10905 Context.hasSameUnqualifiedType(Type, Context.getAutoDeductType()) &&
10906 DeduceInit->getType()->isConstantArrayType())
10907 return Context.getQualifiedType(DeduceInit->getType(),
10908 Type.getQualifiers());
10910 QualType DeducedType;
10911 if (DeduceAutoType(TSI, DeduceInit, DeducedType) == DAR_Failed) {
10912 if (!IsInitCapture)
10913 DiagnoseAutoDeductionFailure(VDecl, DeduceInit);
10914 else if (isa<InitListExpr>(Init))
10915 Diag(Range.getBegin(),
10916 diag::err_init_capture_deduction_failure_from_init_list)
10918 << (DeduceInit->getType().isNull() ? TSI->getType()
10919 : DeduceInit->getType())
10920 << DeduceInit->getSourceRange();
10922 Diag(Range.getBegin(), diag::err_init_capture_deduction_failure)
10923 << VN << TSI->getType()
10924 << (DeduceInit->getType().isNull() ? TSI->getType()
10925 : DeduceInit->getType())
10926 << DeduceInit->getSourceRange();
10930 // Warn if we deduced 'id'. 'auto' usually implies type-safety, but using
10931 // 'id' instead of a specific object type prevents most of our usual
10933 // We only want to warn outside of template instantiations, though:
10934 // inside a template, the 'id' could have come from a parameter.
10935 if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture &&
10936 !DeducedType.isNull() && DeducedType->isObjCIdType()) {
10937 SourceLocation Loc = TSI->getTypeLoc().getBeginLoc();
10938 Diag(Loc, diag::warn_auto_var_is_id) << VN << Range;
10941 return DeducedType;
10944 bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
10946 QualType DeducedType = deduceVarTypeFromInitializer(
10947 VDecl, VDecl->getDeclName(), VDecl->getType(), VDecl->getTypeSourceInfo(),
10948 VDecl->getSourceRange(), DirectInit, Init);
10949 if (DeducedType.isNull()) {
10950 VDecl->setInvalidDecl();
10954 VDecl->setType(DeducedType);
10955 assert(VDecl->isLinkageValid());
10957 // In ARC, infer lifetime.
10958 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(VDecl))
10959 VDecl->setInvalidDecl();
10961 // If this is a redeclaration, check that the type we just deduced matches
10962 // the previously declared type.
10963 if (VarDecl *Old = VDecl->getPreviousDecl()) {
10964 // We never need to merge the type, because we cannot form an incomplete
10965 // array of auto, nor deduce such a type.
10966 MergeVarDeclTypes(VDecl, Old, /*MergeTypeWithPrevious*/ false);
10969 // Check the deduced type is valid for a variable declaration.
10970 CheckVariableDeclarationType(VDecl);
10971 return VDecl->isInvalidDecl();
10974 /// AddInitializerToDecl - Adds the initializer Init to the
10975 /// declaration dcl. If DirectInit is true, this is C++ direct
10976 /// initialization rather than copy initialization.
10977 void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
10978 // If there is no declaration, there was an error parsing it. Just ignore
10979 // the initializer.
10980 if (!RealDecl || RealDecl->isInvalidDecl()) {
10981 CorrectDelayedTyposInExpr(Init, dyn_cast_or_null<VarDecl>(RealDecl));
10985 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
10986 // Pure-specifiers are handled in ActOnPureSpecifier.
10987 Diag(Method->getLocation(), diag::err_member_function_initialization)
10988 << Method->getDeclName() << Init->getSourceRange();
10989 Method->setInvalidDecl();
10993 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
10995 assert(!isa<FieldDecl>(RealDecl) && "field init shouldn't get here");
10996 Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
10997 RealDecl->setInvalidDecl();
11001 // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
11002 if (VDecl->getType()->isUndeducedType()) {
11003 // Attempt typo correction early so that the type of the init expression can
11004 // be deduced based on the chosen correction if the original init contains a
11006 ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl);
11007 if (!Res.isUsable()) {
11008 RealDecl->setInvalidDecl();
11013 if (DeduceVariableDeclarationType(VDecl, DirectInit, Init))
11017 // dllimport cannot be used on variable definitions.
11018 if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
11019 Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition);
11020 VDecl->setInvalidDecl();
11024 if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
11025 // C99 6.7.8p5. C++ has no such restriction, but that is a defect.
11026 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
11027 VDecl->setInvalidDecl();
11031 if (!VDecl->getType()->isDependentType()) {
11032 // A definition must end up with a complete type, which means it must be
11033 // complete with the restriction that an array type might be completed by
11034 // the initializer; note that later code assumes this restriction.
11035 QualType BaseDeclType = VDecl->getType();
11036 if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType))
11037 BaseDeclType = Array->getElementType();
11038 if (RequireCompleteType(VDecl->getLocation(), BaseDeclType,
11039 diag::err_typecheck_decl_incomplete_type)) {
11040 RealDecl->setInvalidDecl();
11044 // The variable can not have an abstract class type.
11045 if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
11046 diag::err_abstract_type_in_decl,
11047 AbstractVariableType))
11048 VDecl->setInvalidDecl();
11051 // If adding the initializer will turn this declaration into a definition,
11052 // and we already have a definition for this variable, diagnose or otherwise
11053 // handle the situation.
11055 if ((Def = VDecl->getDefinition()) && Def != VDecl &&
11056 (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) &&
11057 !VDecl->isThisDeclarationADemotedDefinition() &&
11058 checkVarDeclRedefinition(Def, VDecl))
11061 if (getLangOpts().CPlusPlus) {
11062 // C++ [class.static.data]p4
11063 // If a static data member is of const integral or const
11064 // enumeration type, its declaration in the class definition can
11065 // specify a constant-initializer which shall be an integral
11066 // constant expression (5.19). In that case, the member can appear
11067 // in integral constant expressions. The member shall still be
11068 // defined in a namespace scope if it is used in the program and the
11069 // namespace scope definition shall not contain an initializer.
11071 // We already performed a redefinition check above, but for static
11072 // data members we also need to check whether there was an in-class
11073 // declaration with an initializer.
11074 if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) {
11075 Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization)
11076 << VDecl->getDeclName();
11077 Diag(VDecl->getCanonicalDecl()->getInit()->getExprLoc(),
11078 diag::note_previous_initializer)
11083 if (VDecl->hasLocalStorage())
11084 setFunctionHasBranchProtectedScope();
11086 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) {
11087 VDecl->setInvalidDecl();
11092 // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside
11093 // a kernel function cannot be initialized."
11094 if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) {
11095 Diag(VDecl->getLocation(), diag::err_local_cant_init);
11096 VDecl->setInvalidDecl();
11100 // Get the decls type and save a reference for later, since
11101 // CheckInitializerTypes may change it.
11102 QualType DclT = VDecl->getType(), SavT = DclT;
11104 // Expressions default to 'id' when we're in a debugger
11105 // and we are assigning it to a variable of Objective-C pointer type.
11106 if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() &&
11107 Init->getType() == Context.UnknownAnyTy) {
11108 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
11109 if (Result.isInvalid()) {
11110 VDecl->setInvalidDecl();
11113 Init = Result.get();
11116 // Perform the initialization.
11117 ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
11118 if (!VDecl->isInvalidDecl()) {
11119 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
11120 InitializationKind Kind = InitializationKind::CreateForInit(
11121 VDecl->getLocation(), DirectInit, Init);
11123 MultiExprArg Args = Init;
11125 Args = MultiExprArg(CXXDirectInit->getExprs(),
11126 CXXDirectInit->getNumExprs());
11128 // Try to correct any TypoExprs in the initialization arguments.
11129 for (size_t Idx = 0; Idx < Args.size(); ++Idx) {
11130 ExprResult Res = CorrectDelayedTyposInExpr(
11131 Args[Idx], VDecl, [this, Entity, Kind](Expr *E) {
11132 InitializationSequence Init(*this, Entity, Kind, MultiExprArg(E));
11133 return Init.Failed() ? ExprError() : E;
11135 if (Res.isInvalid()) {
11136 VDecl->setInvalidDecl();
11137 } else if (Res.get() != Args[Idx]) {
11138 Args[Idx] = Res.get();
11141 if (VDecl->isInvalidDecl())
11144 InitializationSequence InitSeq(*this, Entity, Kind, Args,
11145 /*TopLevelOfInitList=*/false,
11146 /*TreatUnavailableAsInvalid=*/false);
11147 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
11148 if (Result.isInvalid()) {
11149 VDecl->setInvalidDecl();
11153 Init = Result.getAs<Expr>();
11156 // Check for self-references within variable initializers.
11157 // Variables declared within a function/method body (except for references)
11158 // are handled by a dataflow analysis.
11159 if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() ||
11160 VDecl->getType()->isReferenceType()) {
11161 CheckSelfReference(*this, RealDecl, Init, DirectInit);
11164 // If the type changed, it means we had an incomplete type that was
11165 // completed by the initializer. For example:
11166 // int ary[] = { 1, 3, 5 };
11167 // "ary" transitions from an IncompleteArrayType to a ConstantArrayType.
11168 if (!VDecl->isInvalidDecl() && (DclT != SavT))
11169 VDecl->setType(DclT);
11171 if (!VDecl->isInvalidDecl()) {
11172 checkUnsafeAssigns(VDecl->getLocation(), VDecl->getType(), Init);
11174 if (VDecl->hasAttr<BlocksAttr>())
11175 checkRetainCycles(VDecl, Init);
11177 // It is safe to assign a weak reference into a strong variable.
11178 // Although this code can still have problems:
11179 // id x = self.weakProp;
11180 // id y = self.weakProp;
11181 // we do not warn to warn spuriously when 'x' and 'y' are on separate
11182 // paths through the function. This should be revisited if
11183 // -Wrepeated-use-of-weak is made flow-sensitive.
11184 if (FunctionScopeInfo *FSI = getCurFunction())
11185 if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
11186 VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) &&
11187 !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak,
11188 Init->getBeginLoc()))
11189 FSI->markSafeWeakUse(Init);
11192 // The initialization is usually a full-expression.
11194 // FIXME: If this is a braced initialization of an aggregate, it is not
11195 // an expression, and each individual field initializer is a separate
11196 // full-expression. For instance, in:
11198 // struct Temp { ~Temp(); };
11199 // struct S { S(Temp); };
11200 // struct T { S a, b; } t = { Temp(), Temp() }
11202 // we should destroy the first Temp before constructing the second.
11203 ExprResult Result = ActOnFinishFullExpr(Init, VDecl->getLocation(),
11205 VDecl->isConstexpr());
11206 if (Result.isInvalid()) {
11207 VDecl->setInvalidDecl();
11210 Init = Result.get();
11212 // Attach the initializer to the decl.
11213 VDecl->setInit(Init);
11215 if (VDecl->isLocalVarDecl()) {
11216 // Don't check the initializer if the declaration is malformed.
11217 if (VDecl->isInvalidDecl()) {
11220 // OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized.
11221 // This is true even in OpenCL C++.
11222 } else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) {
11223 CheckForConstantInitializer(Init, DclT);
11225 // Otherwise, C++ does not restrict the initializer.
11226 } else if (getLangOpts().CPlusPlus) {
11229 // C99 6.7.8p4: All the expressions in an initializer for an object that has
11230 // static storage duration shall be constant expressions or string literals.
11231 } else if (VDecl->getStorageClass() == SC_Static) {
11232 CheckForConstantInitializer(Init, DclT);
11234 // C89 is stricter than C99 for aggregate initializers.
11235 // C89 6.5.7p3: All the expressions [...] in an initializer list
11236 // for an object that has aggregate or union type shall be
11237 // constant expressions.
11238 } else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() &&
11239 isa<InitListExpr>(Init)) {
11240 const Expr *Culprit;
11241 if (!Init->isConstantInitializer(Context, false, &Culprit)) {
11242 Diag(Culprit->getExprLoc(),
11243 diag::ext_aggregate_init_not_constant)
11244 << Culprit->getSourceRange();
11247 } else if (VDecl->isStaticDataMember() && !VDecl->isInline() &&
11248 VDecl->getLexicalDeclContext()->isRecord()) {
11249 // This is an in-class initialization for a static data member, e.g.,
11252 // static const int value = 17;
11255 // C++ [class.mem]p4:
11256 // A member-declarator can contain a constant-initializer only
11257 // if it declares a static member (9.4) of const integral or
11258 // const enumeration type, see 9.4.2.
11260 // C++11 [class.static.data]p3:
11261 // If a non-volatile non-inline const static data member is of integral
11262 // or enumeration type, its declaration in the class definition can
11263 // specify a brace-or-equal-initializer in which every initializer-clause
11264 // that is an assignment-expression is a constant expression. A static
11265 // data member of literal type can be declared in the class definition
11266 // with the constexpr specifier; if so, its declaration shall specify a
11267 // brace-or-equal-initializer in which every initializer-clause that is
11268 // an assignment-expression is a constant expression.
11270 // Do nothing on dependent types.
11271 if (DclT->isDependentType()) {
11273 // Allow any 'static constexpr' members, whether or not they are of literal
11274 // type. We separately check that every constexpr variable is of literal
11276 } else if (VDecl->isConstexpr()) {
11278 // Require constness.
11279 } else if (!DclT.isConstQualified()) {
11280 Diag(VDecl->getLocation(), diag::err_in_class_initializer_non_const)
11281 << Init->getSourceRange();
11282 VDecl->setInvalidDecl();
11284 // We allow integer constant expressions in all cases.
11285 } else if (DclT->isIntegralOrEnumerationType()) {
11286 // Check whether the expression is a constant expression.
11287 SourceLocation Loc;
11288 if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified())
11289 // In C++11, a non-constexpr const static data member with an
11290 // in-class initializer cannot be volatile.
11291 Diag(VDecl->getLocation(), diag::err_in_class_initializer_volatile);
11292 else if (Init->isValueDependent())
11293 ; // Nothing to check.
11294 else if (Init->isIntegerConstantExpr(Context, &Loc))
11295 ; // Ok, it's an ICE!
11296 else if (Init->getType()->isScopedEnumeralType() &&
11297 Init->isCXX11ConstantExpr(Context))
11298 ; // Ok, it is a scoped-enum constant expression.
11299 else if (Init->isEvaluatable(Context)) {
11300 // If we can constant fold the initializer through heroics, accept it,
11301 // but report this as a use of an extension for -pedantic.
11302 Diag(Loc, diag::ext_in_class_initializer_non_constant)
11303 << Init->getSourceRange();
11305 // Otherwise, this is some crazy unknown case. Report the issue at the
11306 // location provided by the isIntegerConstantExpr failed check.
11307 Diag(Loc, diag::err_in_class_initializer_non_constant)
11308 << Init->getSourceRange();
11309 VDecl->setInvalidDecl();
11312 // We allow foldable floating-point constants as an extension.
11313 } else if (DclT->isFloatingType()) { // also permits complex, which is ok
11314 // In C++98, this is a GNU extension. In C++11, it is not, but we support
11315 // it anyway and provide a fixit to add the 'constexpr'.
11316 if (getLangOpts().CPlusPlus11) {
11317 Diag(VDecl->getLocation(),
11318 diag::ext_in_class_initializer_float_type_cxx11)
11319 << DclT << Init->getSourceRange();
11320 Diag(VDecl->getBeginLoc(),
11321 diag::note_in_class_initializer_float_type_cxx11)
11322 << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr ");
11324 Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type)
11325 << DclT << Init->getSourceRange();
11327 if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) {
11328 Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant)
11329 << Init->getSourceRange();
11330 VDecl->setInvalidDecl();
11334 // Suggest adding 'constexpr' in C++11 for literal types.
11335 } else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Context)) {
11336 Diag(VDecl->getLocation(), diag::err_in_class_initializer_literal_type)
11337 << DclT << Init->getSourceRange()
11338 << FixItHint::CreateInsertion(VDecl->getBeginLoc(), "constexpr ");
11339 VDecl->setConstexpr(true);
11342 Diag(VDecl->getLocation(), diag::err_in_class_initializer_bad_type)
11343 << DclT << Init->getSourceRange();
11344 VDecl->setInvalidDecl();
11346 } else if (VDecl->isFileVarDecl()) {
11347 // In C, extern is typically used to avoid tentative definitions when
11348 // declaring variables in headers, but adding an intializer makes it a
11349 // definition. This is somewhat confusing, so GCC and Clang both warn on it.
11350 // In C++, extern is often used to give implictly static const variables
11351 // external linkage, so don't warn in that case. If selectany is present,
11352 // this might be header code intended for C and C++ inclusion, so apply the
11354 if (VDecl->getStorageClass() == SC_Extern &&
11355 ((!getLangOpts().CPlusPlus && !VDecl->hasAttr<SelectAnyAttr>()) ||
11356 !Context.getBaseElementType(VDecl->getType()).isConstQualified()) &&
11357 !(getLangOpts().CPlusPlus && VDecl->isExternC()) &&
11358 !isTemplateInstantiation(VDecl->getTemplateSpecializationKind()))
11359 Diag(VDecl->getLocation(), diag::warn_extern_init);
11361 // C99 6.7.8p4. All file scoped initializers need to be constant.
11362 if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl())
11363 CheckForConstantInitializer(Init, DclT);
11366 // We will represent direct-initialization similarly to copy-initialization:
11367 // int x(1); -as-> int x = 1;
11368 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
11370 // Clients that want to distinguish between the two forms, can check for
11371 // direct initializer using VarDecl::getInitStyle().
11372 // A major benefit is that clients that don't particularly care about which
11373 // exactly form was it (like the CodeGen) can handle both cases without
11374 // special case code.
11377 // The form of initialization (using parentheses or '=') is generally
11378 // insignificant, but does matter when the entity being initialized has a
11380 if (CXXDirectInit) {
11381 assert(DirectInit && "Call-style initializer must be direct init.");
11382 VDecl->setInitStyle(VarDecl::CallInit);
11383 } else if (DirectInit) {
11384 // This must be list-initialization. No other way is direct-initialization.
11385 VDecl->setInitStyle(VarDecl::ListInit);
11388 CheckCompleteVariableDeclaration(VDecl);
11391 /// ActOnInitializerError - Given that there was an error parsing an
11392 /// initializer for the given declaration, try to return to some form
11394 void Sema::ActOnInitializerError(Decl *D) {
11395 // Our main concern here is re-establishing invariants like "a
11396 // variable's type is either dependent or complete".
11397 if (!D || D->isInvalidDecl()) return;
11399 VarDecl *VD = dyn_cast<VarDecl>(D);
11402 // Bindings are not usable if we can't make sense of the initializer.
11403 if (auto *DD = dyn_cast<DecompositionDecl>(D))
11404 for (auto *BD : DD->bindings())
11405 BD->setInvalidDecl();
11407 // Auto types are meaningless if we can't make sense of the initializer.
11408 if (ParsingInitForAutoVars.count(D)) {
11409 D->setInvalidDecl();
11413 QualType Ty = VD->getType();
11414 if (Ty->isDependentType()) return;
11416 // Require a complete type.
11417 if (RequireCompleteType(VD->getLocation(),
11418 Context.getBaseElementType(Ty),
11419 diag::err_typecheck_decl_incomplete_type)) {
11420 VD->setInvalidDecl();
11424 // Require a non-abstract type.
11425 if (RequireNonAbstractType(VD->getLocation(), Ty,
11426 diag::err_abstract_type_in_decl,
11427 AbstractVariableType)) {
11428 VD->setInvalidDecl();
11432 // Don't bother complaining about constructors or destructors,
11436 void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
11437 // If there is no declaration, there was an error parsing it. Just ignore it.
11441 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
11442 QualType Type = Var->getType();
11444 // C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory.
11445 if (isa<DecompositionDecl>(RealDecl)) {
11446 Diag(Var->getLocation(), diag::err_decomp_decl_requires_init) << Var;
11447 Var->setInvalidDecl();
11451 Expr *TmpInit = nullptr;
11452 if (Type->isUndeducedType() &&
11453 DeduceVariableDeclarationType(Var, false, TmpInit))
11456 // C++11 [class.static.data]p3: A static data member can be declared with
11457 // the constexpr specifier; if so, its declaration shall specify
11458 // a brace-or-equal-initializer.
11459 // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
11460 // the definition of a variable [...] or the declaration of a static data
11462 if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() &&
11463 !Var->isThisDeclarationADemotedDefinition()) {
11464 if (Var->isStaticDataMember()) {
11465 // C++1z removes the relevant rule; the in-class declaration is always
11466 // a definition there.
11467 if (!getLangOpts().CPlusPlus17) {
11468 Diag(Var->getLocation(),
11469 diag::err_constexpr_static_mem_var_requires_init)
11470 << Var->getDeclName();
11471 Var->setInvalidDecl();
11475 Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl);
11476 Var->setInvalidDecl();
11481 // OpenCL v1.1 s6.5.3: variables declared in the constant address space must
11483 if (!Var->isInvalidDecl() &&
11484 Var->getType().getAddressSpace() == LangAS::opencl_constant &&
11485 Var->getStorageClass() != SC_Extern && !Var->getInit()) {
11486 Diag(Var->getLocation(), diag::err_opencl_constant_no_init);
11487 Var->setInvalidDecl();
11491 switch (Var->isThisDeclarationADefinition()) {
11492 case VarDecl::Definition:
11493 if (!Var->isStaticDataMember() || !Var->getAnyInitializer())
11496 // We have an out-of-line definition of a static data member
11497 // that has an in-class initializer, so we type-check this like
11502 case VarDecl::DeclarationOnly:
11503 // It's only a declaration.
11505 // Block scope. C99 6.7p7: If an identifier for an object is
11506 // declared with no linkage (C99 6.2.2p6), the type for the
11507 // object shall be complete.
11508 if (!Type->isDependentType() && Var->isLocalVarDecl() &&
11509 !Var->hasLinkage() && !Var->isInvalidDecl() &&
11510 RequireCompleteType(Var->getLocation(), Type,
11511 diag::err_typecheck_decl_incomplete_type))
11512 Var->setInvalidDecl();
11514 // Make sure that the type is not abstract.
11515 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
11516 RequireNonAbstractType(Var->getLocation(), Type,
11517 diag::err_abstract_type_in_decl,
11518 AbstractVariableType))
11519 Var->setInvalidDecl();
11520 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
11521 Var->getStorageClass() == SC_PrivateExtern) {
11522 Diag(Var->getLocation(), diag::warn_private_extern);
11523 Diag(Var->getLocation(), diag::note_private_extern);
11528 case VarDecl::TentativeDefinition:
11529 // File scope. C99 6.9.2p2: A declaration of an identifier for an
11530 // object that has file scope without an initializer, and without a
11531 // storage-class specifier or with the storage-class specifier "static",
11532 // constitutes a tentative definition. Note: A tentative definition with
11533 // external linkage is valid (C99 6.2.2p5).
11534 if (!Var->isInvalidDecl()) {
11535 if (const IncompleteArrayType *ArrayT
11536 = Context.getAsIncompleteArrayType(Type)) {
11537 if (RequireCompleteType(Var->getLocation(),
11538 ArrayT->getElementType(),
11539 diag::err_illegal_decl_array_incomplete_type))
11540 Var->setInvalidDecl();
11541 } else if (Var->getStorageClass() == SC_Static) {
11542 // C99 6.9.2p3: If the declaration of an identifier for an object is
11543 // a tentative definition and has internal linkage (C99 6.2.2p3), the
11544 // declared type shall not be an incomplete type.
11545 // NOTE: code such as the following
11546 // static struct s;
11547 // struct s { int a; };
11548 // is accepted by gcc. Hence here we issue a warning instead of
11549 // an error and we do not invalidate the static declaration.
11550 // NOTE: to avoid multiple warnings, only check the first declaration.
11551 if (Var->isFirstDecl())
11552 RequireCompleteType(Var->getLocation(), Type,
11553 diag::ext_typecheck_decl_incomplete_type);
11557 // Record the tentative definition; we're done.
11558 if (!Var->isInvalidDecl())
11559 TentativeDefinitions.push_back(Var);
11563 // Provide a specific diagnostic for uninitialized variable
11564 // definitions with incomplete array type.
11565 if (Type->isIncompleteArrayType()) {
11566 Diag(Var->getLocation(),
11567 diag::err_typecheck_incomplete_array_needs_initializer);
11568 Var->setInvalidDecl();
11572 // Provide a specific diagnostic for uninitialized variable
11573 // definitions with reference type.
11574 if (Type->isReferenceType()) {
11575 Diag(Var->getLocation(), diag::err_reference_var_requires_init)
11576 << Var->getDeclName()
11577 << SourceRange(Var->getLocation(), Var->getLocation());
11578 Var->setInvalidDecl();
11582 // Do not attempt to type-check the default initializer for a
11583 // variable with dependent type.
11584 if (Type->isDependentType())
11587 if (Var->isInvalidDecl())
11590 if (!Var->hasAttr<AliasAttr>()) {
11591 if (RequireCompleteType(Var->getLocation(),
11592 Context.getBaseElementType(Type),
11593 diag::err_typecheck_decl_incomplete_type)) {
11594 Var->setInvalidDecl();
11601 // The variable can not have an abstract class type.
11602 if (RequireNonAbstractType(Var->getLocation(), Type,
11603 diag::err_abstract_type_in_decl,
11604 AbstractVariableType)) {
11605 Var->setInvalidDecl();
11609 // Check for jumps past the implicit initializer. C++0x
11610 // clarifies that this applies to a "variable with automatic
11611 // storage duration", not a "local variable".
11612 // C++11 [stmt.dcl]p3
11613 // A program that jumps from a point where a variable with automatic
11614 // storage duration is not in scope to a point where it is in scope is
11615 // ill-formed unless the variable has scalar type, class type with a
11616 // trivial default constructor and a trivial destructor, a cv-qualified
11617 // version of one of these types, or an array of one of the preceding
11618 // types and is declared without an initializer.
11619 if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) {
11620 if (const RecordType *Record
11621 = Context.getBaseElementType(Type)->getAs<RecordType>()) {
11622 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record->getDecl());
11623 // Mark the function (if we're in one) for further checking even if the
11624 // looser rules of C++11 do not require such checks, so that we can
11625 // diagnose incompatibilities with C++98.
11626 if (!CXXRecord->isPOD())
11627 setFunctionHasBranchProtectedScope();
11631 // C++03 [dcl.init]p9:
11632 // If no initializer is specified for an object, and the
11633 // object is of (possibly cv-qualified) non-POD class type (or
11634 // array thereof), the object shall be default-initialized; if
11635 // the object is of const-qualified type, the underlying class
11636 // type shall have a user-declared default
11637 // constructor. Otherwise, if no initializer is specified for
11638 // a non- static object, the object and its subobjects, if
11639 // any, have an indeterminate initial value); if the object
11640 // or any of its subobjects are of const-qualified type, the
11641 // program is ill-formed.
11642 // C++0x [dcl.init]p11:
11643 // If no initializer is specified for an object, the object is
11644 // default-initialized; [...].
11645 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var);
11646 InitializationKind Kind
11647 = InitializationKind::CreateDefault(Var->getLocation());
11649 InitializationSequence InitSeq(*this, Entity, Kind, None);
11650 ExprResult Init = InitSeq.Perform(*this, Entity, Kind, None);
11651 if (Init.isInvalid())
11652 Var->setInvalidDecl();
11653 else if (Init.get()) {
11654 Var->setInit(MaybeCreateExprWithCleanups(Init.get()));
11655 // This is important for template substitution.
11656 Var->setInitStyle(VarDecl::CallInit);
11659 CheckCompleteVariableDeclaration(Var);
11663 void Sema::ActOnCXXForRangeDecl(Decl *D) {
11664 // If there is no declaration, there was an error parsing it. Ignore it.
11668 VarDecl *VD = dyn_cast<VarDecl>(D);
11670 Diag(D->getLocation(), diag::err_for_range_decl_must_be_var);
11671 D->setInvalidDecl();
11675 VD->setCXXForRangeDecl(true);
11677 // for-range-declaration cannot be given a storage class specifier.
11679 switch (VD->getStorageClass()) {
11688 case SC_PrivateExtern:
11699 Diag(VD->getOuterLocStart(), diag::err_for_range_storage_class)
11700 << VD->getDeclName() << Error;
11701 D->setInvalidDecl();
11706 Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
11707 IdentifierInfo *Ident,
11708 ParsedAttributes &Attrs,
11709 SourceLocation AttrEnd) {
11710 // C++1y [stmt.iter]p1:
11711 // A range-based for statement of the form
11712 // for ( for-range-identifier : for-range-initializer ) statement
11713 // is equivalent to
11714 // for ( auto&& for-range-identifier : for-range-initializer ) statement
11715 DeclSpec DS(Attrs.getPool().getFactory());
11717 const char *PrevSpec;
11719 DS.SetTypeSpecType(DeclSpec::TST_auto, IdentLoc, PrevSpec, DiagID,
11720 getPrintingPolicy());
11722 Declarator D(DS, DeclaratorContext::ForContext);
11723 D.SetIdentifier(Ident, IdentLoc);
11724 D.takeAttributes(Attrs, AttrEnd);
11726 ParsedAttributes EmptyAttrs(Attrs.getPool().getFactory());
11727 D.AddTypeInfo(DeclaratorChunk::getReference(0, IdentLoc, /*lvalue*/ false),
11729 Decl *Var = ActOnDeclarator(S, D);
11730 cast<VarDecl>(Var)->setCXXForRangeDecl(true);
11731 FinalizeDeclaration(Var);
11732 return ActOnDeclStmt(FinalizeDeclaratorGroup(S, DS, Var), IdentLoc,
11733 AttrEnd.isValid() ? AttrEnd : IdentLoc);
11736 void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
11737 if (var->isInvalidDecl()) return;
11739 if (getLangOpts().OpenCL) {
11740 // OpenCL v2.0 s6.12.5 - Every block variable declaration must have an
11742 if (var->getTypeSourceInfo()->getType()->isBlockPointerType() &&
11744 Diag(var->getLocation(), diag::err_opencl_invalid_block_declaration)
11746 var->setInvalidDecl();
11751 // In Objective-C, don't allow jumps past the implicit initialization of a
11752 // local retaining variable.
11753 if (getLangOpts().ObjC &&
11754 var->hasLocalStorage()) {
11755 switch (var->getType().getObjCLifetime()) {
11756 case Qualifiers::OCL_None:
11757 case Qualifiers::OCL_ExplicitNone:
11758 case Qualifiers::OCL_Autoreleasing:
11761 case Qualifiers::OCL_Weak:
11762 case Qualifiers::OCL_Strong:
11763 setFunctionHasBranchProtectedScope();
11768 if (var->hasLocalStorage() &&
11769 var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
11770 setFunctionHasBranchProtectedScope();
11772 // Warn about externally-visible variables being defined without a
11773 // prior declaration. We only want to do this for global
11774 // declarations, but we also specifically need to avoid doing it for
11775 // class members because the linkage of an anonymous class can
11776 // change if it's later given a typedef name.
11777 if (var->isThisDeclarationADefinition() &&
11778 var->getDeclContext()->getRedeclContext()->isFileContext() &&
11779 var->isExternallyVisible() && var->hasLinkage() &&
11780 !var->isInline() && !var->getDescribedVarTemplate() &&
11781 !isTemplateInstantiation(var->getTemplateSpecializationKind()) &&
11782 !getDiagnostics().isIgnored(diag::warn_missing_variable_declarations,
11783 var->getLocation())) {
11784 // Find a previous declaration that's not a definition.
11785 VarDecl *prev = var->getPreviousDecl();
11786 while (prev && prev->isThisDeclarationADefinition())
11787 prev = prev->getPreviousDecl();
11790 Diag(var->getLocation(), diag::warn_missing_variable_declarations) << var;
11793 // Cache the result of checking for constant initialization.
11794 Optional<bool> CacheHasConstInit;
11795 const Expr *CacheCulprit;
11796 auto checkConstInit = [&]() mutable {
11797 if (!CacheHasConstInit)
11798 CacheHasConstInit = var->getInit()->isConstantInitializer(
11799 Context, var->getType()->isReferenceType(), &CacheCulprit);
11800 return *CacheHasConstInit;
11803 if (var->getTLSKind() == VarDecl::TLS_Static) {
11804 if (var->getType().isDestructedType()) {
11805 // GNU C++98 edits for __thread, [basic.start.term]p3:
11806 // The type of an object with thread storage duration shall not
11807 // have a non-trivial destructor.
11808 Diag(var->getLocation(), diag::err_thread_nontrivial_dtor);
11809 if (getLangOpts().CPlusPlus11)
11810 Diag(var->getLocation(), diag::note_use_thread_local);
11811 } else if (getLangOpts().CPlusPlus && var->hasInit()) {
11812 if (!checkConstInit()) {
11813 // GNU C++98 edits for __thread, [basic.start.init]p4:
11814 // An object of thread storage duration shall not require dynamic
11816 // FIXME: Need strict checking here.
11817 Diag(CacheCulprit->getExprLoc(), diag::err_thread_dynamic_init)
11818 << CacheCulprit->getSourceRange();
11819 if (getLangOpts().CPlusPlus11)
11820 Diag(var->getLocation(), diag::note_use_thread_local);
11825 // Apply section attributes and pragmas to global variables.
11826 bool GlobalStorage = var->hasGlobalStorage();
11827 if (GlobalStorage && var->isThisDeclarationADefinition() &&
11828 !inTemplateInstantiation()) {
11829 PragmaStack<StringLiteral *> *Stack = nullptr;
11830 int SectionFlags = ASTContext::PSF_Implicit | ASTContext::PSF_Read;
11831 if (var->getType().isConstQualified())
11832 Stack = &ConstSegStack;
11833 else if (!var->getInit()) {
11834 Stack = &BSSSegStack;
11835 SectionFlags |= ASTContext::PSF_Write;
11837 Stack = &DataSegStack;
11838 SectionFlags |= ASTContext::PSF_Write;
11840 if (Stack->CurrentValue && !var->hasAttr<SectionAttr>()) {
11841 var->addAttr(SectionAttr::CreateImplicit(
11842 Context, SectionAttr::Declspec_allocate,
11843 Stack->CurrentValue->getString(), Stack->CurrentPragmaLocation));
11845 if (const SectionAttr *SA = var->getAttr<SectionAttr>())
11846 if (UnifySection(SA->getName(), SectionFlags, var))
11847 var->dropAttr<SectionAttr>();
11849 // Apply the init_seg attribute if this has an initializer. If the
11850 // initializer turns out to not be dynamic, we'll end up ignoring this
11852 if (CurInitSeg && var->getInit())
11853 var->addAttr(InitSegAttr::CreateImplicit(Context, CurInitSeg->getString(),
11857 // All the following checks are C++ only.
11858 if (!getLangOpts().CPlusPlus) {
11859 // If this variable must be emitted, add it as an initializer for the
11861 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
11862 Context.addModuleInitializer(ModuleScopes.back().Module, var);
11866 if (auto *DD = dyn_cast<DecompositionDecl>(var))
11867 CheckCompleteDecompositionDeclaration(DD);
11869 QualType type = var->getType();
11870 if (type->isDependentType()) return;
11872 if (var->hasAttr<BlocksAttr>())
11873 getCurFunction()->addByrefBlockVar(var);
11875 Expr *Init = var->getInit();
11876 bool IsGlobal = GlobalStorage && !var->isStaticLocal();
11877 QualType baseType = Context.getBaseElementType(type);
11879 if (Init && !Init->isValueDependent()) {
11880 if (var->isConstexpr()) {
11881 SmallVector<PartialDiagnosticAt, 8> Notes;
11882 if (!var->evaluateValue(Notes) || !var->isInitICE()) {
11883 SourceLocation DiagLoc = var->getLocation();
11884 // If the note doesn't add any useful information other than a source
11885 // location, fold it into the primary diagnostic.
11886 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
11887 diag::note_invalid_subexpr_in_const_expr) {
11888 DiagLoc = Notes[0].first;
11891 Diag(DiagLoc, diag::err_constexpr_var_requires_const_init)
11892 << var << Init->getSourceRange();
11893 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
11894 Diag(Notes[I].first, Notes[I].second);
11896 } else if (var->isUsableInConstantExpressions(Context)) {
11897 // Check whether the initializer of a const variable of integral or
11898 // enumeration type is an ICE now, since we can't tell whether it was
11899 // initialized by a constant expression if we check later.
11900 var->checkInitIsICE();
11903 // Don't emit further diagnostics about constexpr globals since they
11904 // were just diagnosed.
11905 if (!var->isConstexpr() && GlobalStorage &&
11906 var->hasAttr<RequireConstantInitAttr>()) {
11907 // FIXME: Need strict checking in C++03 here.
11908 bool DiagErr = getLangOpts().CPlusPlus11
11909 ? !var->checkInitIsICE() : !checkConstInit();
11911 auto attr = var->getAttr<RequireConstantInitAttr>();
11912 Diag(var->getLocation(), diag::err_require_constant_init_failed)
11913 << Init->getSourceRange();
11914 Diag(attr->getLocation(), diag::note_declared_required_constant_init_here)
11915 << attr->getRange();
11916 if (getLangOpts().CPlusPlus11) {
11918 SmallVector<PartialDiagnosticAt, 8> Notes;
11919 Init->EvaluateAsInitializer(Value, getASTContext(), var, Notes);
11920 for (auto &it : Notes)
11921 Diag(it.first, it.second);
11923 Diag(CacheCulprit->getExprLoc(),
11924 diag::note_invalid_subexpr_in_const_expr)
11925 << CacheCulprit->getSourceRange();
11929 else if (!var->isConstexpr() && IsGlobal &&
11930 !getDiagnostics().isIgnored(diag::warn_global_constructor,
11931 var->getLocation())) {
11932 // Warn about globals which don't have a constant initializer. Don't
11933 // warn about globals with a non-trivial destructor because we already
11934 // warned about them.
11935 CXXRecordDecl *RD = baseType->getAsCXXRecordDecl();
11936 if (!(RD && !RD->hasTrivialDestructor())) {
11937 if (!checkConstInit())
11938 Diag(var->getLocation(), diag::warn_global_constructor)
11939 << Init->getSourceRange();
11944 // Require the destructor.
11945 if (const RecordType *recordType = baseType->getAs<RecordType>())
11946 FinalizeVarWithDestructor(var, recordType);
11948 // If this variable must be emitted, add it as an initializer for the current
11950 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
11951 Context.addModuleInitializer(ModuleScopes.back().Module, var);
11954 /// Determines if a variable's alignment is dependent.
11955 static bool hasDependentAlignment(VarDecl *VD) {
11956 if (VD->getType()->isDependentType())
11958 for (auto *I : VD->specific_attrs<AlignedAttr>())
11959 if (I->isAlignmentDependent())
11964 /// Check if VD needs to be dllexport/dllimport due to being in a
11965 /// dllexport/import function.
11966 void Sema::CheckStaticLocalForDllExport(VarDecl *VD) {
11967 assert(VD->isStaticLocal());
11969 auto *FD = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
11971 // Find outermost function when VD is in lambda function.
11972 while (FD && !getDLLAttr(FD) &&
11973 !FD->hasAttr<DLLExportStaticLocalAttr>() &&
11974 !FD->hasAttr<DLLImportStaticLocalAttr>()) {
11975 FD = dyn_cast_or_null<FunctionDecl>(FD->getParentFunctionOrMethod());
11981 // Static locals inherit dll attributes from their function.
11982 if (Attr *A = getDLLAttr(FD)) {
11983 auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
11984 NewAttr->setInherited(true);
11985 VD->addAttr(NewAttr);
11986 } else if (Attr *A = FD->getAttr<DLLExportStaticLocalAttr>()) {
11987 auto *NewAttr = ::new (getASTContext()) DLLExportAttr(A->getRange(),
11989 A->getSpellingListIndex());
11990 NewAttr->setInherited(true);
11991 VD->addAttr(NewAttr);
11993 // Export this function to enforce exporting this static variable even
11994 // if it is not used in this compilation unit.
11995 if (!FD->hasAttr<DLLExportAttr>())
11996 FD->addAttr(NewAttr);
11998 } else if (Attr *A = FD->getAttr<DLLImportStaticLocalAttr>()) {
11999 auto *NewAttr = ::new (getASTContext()) DLLImportAttr(A->getRange(),
12001 A->getSpellingListIndex());
12002 NewAttr->setInherited(true);
12003 VD->addAttr(NewAttr);
12007 /// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform
12008 /// any semantic actions necessary after any initializer has been attached.
12009 void Sema::FinalizeDeclaration(Decl *ThisDecl) {
12010 // Note that we are no longer parsing the initializer for this declaration.
12011 ParsingInitForAutoVars.erase(ThisDecl);
12013 VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDecl);
12017 // Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active
12018 if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() &&
12019 !inTemplateInstantiation() && !VD->hasAttr<SectionAttr>()) {
12020 if (PragmaClangBSSSection.Valid)
12021 VD->addAttr(PragmaClangBSSSectionAttr::CreateImplicit(Context,
12022 PragmaClangBSSSection.SectionName,
12023 PragmaClangBSSSection.PragmaLocation));
12024 if (PragmaClangDataSection.Valid)
12025 VD->addAttr(PragmaClangDataSectionAttr::CreateImplicit(Context,
12026 PragmaClangDataSection.SectionName,
12027 PragmaClangDataSection.PragmaLocation));
12028 if (PragmaClangRodataSection.Valid)
12029 VD->addAttr(PragmaClangRodataSectionAttr::CreateImplicit(Context,
12030 PragmaClangRodataSection.SectionName,
12031 PragmaClangRodataSection.PragmaLocation));
12034 if (auto *DD = dyn_cast<DecompositionDecl>(ThisDecl)) {
12035 for (auto *BD : DD->bindings()) {
12036 FinalizeDeclaration(BD);
12040 checkAttributesAfterMerging(*this, *VD);
12042 // Perform TLS alignment check here after attributes attached to the variable
12043 // which may affect the alignment have been processed. Only perform the check
12044 // if the target has a maximum TLS alignment (zero means no constraints).
12045 if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
12046 // Protect the check so that it's not performed on dependent types and
12047 // dependent alignments (we can't determine the alignment in that case).
12048 if (VD->getTLSKind() && !hasDependentAlignment(VD) &&
12049 !VD->isInvalidDecl()) {
12050 CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign);
12051 if (Context.getDeclAlign(VD) > MaxAlignChars) {
12052 Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum)
12053 << (unsigned)Context.getDeclAlign(VD).getQuantity() << VD
12054 << (unsigned)MaxAlignChars.getQuantity();
12059 if (VD->isStaticLocal()) {
12060 CheckStaticLocalForDllExport(VD);
12062 if (dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) {
12063 // CUDA 8.0 E.3.9.4: Within the body of a __device__ or __global__
12064 // function, only __shared__ variables or variables without any device
12065 // memory qualifiers may be declared with static storage class.
12066 // Note: It is unclear how a function-scope non-const static variable
12067 // without device memory qualifier is implemented, therefore only static
12068 // const variable without device memory qualifier is allowed.
12070 if (!getLangOpts().CUDA)
12072 if (VD->hasAttr<CUDASharedAttr>())
12074 if (VD->getType().isConstQualified() &&
12075 !(VD->hasAttr<CUDADeviceAttr>() || VD->hasAttr<CUDAConstantAttr>()))
12077 if (CUDADiagIfDeviceCode(VD->getLocation(),
12078 diag::err_device_static_local_var)
12079 << CurrentCUDATarget())
12080 VD->setInvalidDecl();
12085 // Perform check for initializers of device-side global variables.
12086 // CUDA allows empty constructors as initializers (see E.2.3.1, CUDA
12087 // 7.5). We must also apply the same checks to all __shared__
12088 // variables whether they are local or not. CUDA also allows
12089 // constant initializers for __constant__ and __device__ variables.
12090 if (getLangOpts().CUDA)
12091 checkAllowedCUDAInitializer(VD);
12093 // Grab the dllimport or dllexport attribute off of the VarDecl.
12094 const InheritableAttr *DLLAttr = getDLLAttr(VD);
12096 // Imported static data members cannot be defined out-of-line.
12097 if (const auto *IA = dyn_cast_or_null<DLLImportAttr>(DLLAttr)) {
12098 if (VD->isStaticDataMember() && VD->isOutOfLine() &&
12099 VD->isThisDeclarationADefinition()) {
12100 // We allow definitions of dllimport class template static data members
12102 CXXRecordDecl *Context =
12103 cast<CXXRecordDecl>(VD->getFirstDecl()->getDeclContext());
12104 bool IsClassTemplateMember =
12105 isa<ClassTemplatePartialSpecializationDecl>(Context) ||
12106 Context->getDescribedClassTemplate();
12108 Diag(VD->getLocation(),
12109 IsClassTemplateMember
12110 ? diag::warn_attribute_dllimport_static_field_definition
12111 : diag::err_attribute_dllimport_static_field_definition);
12112 Diag(IA->getLocation(), diag::note_attribute);
12113 if (!IsClassTemplateMember)
12114 VD->setInvalidDecl();
12118 // dllimport/dllexport variables cannot be thread local, their TLS index
12119 // isn't exported with the variable.
12120 if (DLLAttr && VD->getTLSKind()) {
12121 auto *F = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
12122 if (F && getDLLAttr(F)) {
12123 assert(VD->isStaticLocal());
12124 // But if this is a static local in a dlimport/dllexport function, the
12125 // function will never be inlined, which means the var would never be
12126 // imported, so having it marked import/export is safe.
12128 Diag(VD->getLocation(), diag::err_attribute_dll_thread_local) << VD
12130 VD->setInvalidDecl();
12134 if (UsedAttr *Attr = VD->getAttr<UsedAttr>()) {
12135 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
12136 Diag(Attr->getLocation(), diag::warn_attribute_ignored) << Attr;
12137 VD->dropAttr<UsedAttr>();
12141 const DeclContext *DC = VD->getDeclContext();
12142 // If there's a #pragma GCC visibility in scope, and this isn't a class
12143 // member, set the visibility of this variable.
12144 if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
12145 AddPushedVisibilityAttribute(VD);
12147 // FIXME: Warn on unused var template partial specializations.
12148 if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(VD))
12149 MarkUnusedFileScopedDecl(VD);
12151 // Now we have parsed the initializer and can update the table of magic
12153 if (!VD->hasAttr<TypeTagForDatatypeAttr>() ||
12154 !VD->getType()->isIntegralOrEnumerationType())
12157 for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) {
12158 const Expr *MagicValueExpr = VD->getInit();
12159 if (!MagicValueExpr) {
12162 llvm::APSInt MagicValueInt;
12163 if (!MagicValueExpr->isIntegerConstantExpr(MagicValueInt, Context)) {
12164 Diag(I->getRange().getBegin(),
12165 diag::err_type_tag_for_datatype_not_ice)
12166 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
12169 if (MagicValueInt.getActiveBits() > 64) {
12170 Diag(I->getRange().getBegin(),
12171 diag::err_type_tag_for_datatype_too_large)
12172 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
12175 uint64_t MagicValue = MagicValueInt.getZExtValue();
12176 RegisterTypeTagForDatatype(I->getArgumentKind(),
12178 I->getMatchingCType(),
12179 I->getLayoutCompatible(),
12180 I->getMustBeNull());
12184 static bool hasDeducedAuto(DeclaratorDecl *DD) {
12185 auto *VD = dyn_cast<VarDecl>(DD);
12186 return VD && !VD->getType()->hasAutoForTrailingReturnType();
12189 Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
12190 ArrayRef<Decl *> Group) {
12191 SmallVector<Decl*, 8> Decls;
12193 if (DS.isTypeSpecOwned())
12194 Decls.push_back(DS.getRepAsDecl());
12196 DeclaratorDecl *FirstDeclaratorInGroup = nullptr;
12197 DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr;
12198 bool DiagnosedMultipleDecomps = false;
12199 DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr;
12200 bool DiagnosedNonDeducedAuto = false;
12202 for (unsigned i = 0, e = Group.size(); i != e; ++i) {
12203 if (Decl *D = Group[i]) {
12204 // For declarators, there are some additional syntactic-ish checks we need
12206 if (auto *DD = dyn_cast<DeclaratorDecl>(D)) {
12207 if (!FirstDeclaratorInGroup)
12208 FirstDeclaratorInGroup = DD;
12209 if (!FirstDecompDeclaratorInGroup)
12210 FirstDecompDeclaratorInGroup = dyn_cast<DecompositionDecl>(D);
12211 if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() &&
12212 !hasDeducedAuto(DD))
12213 FirstNonDeducedAutoInGroup = DD;
12215 if (FirstDeclaratorInGroup != DD) {
12216 // A decomposition declaration cannot be combined with any other
12217 // declaration in the same group.
12218 if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) {
12219 Diag(FirstDecompDeclaratorInGroup->getLocation(),
12220 diag::err_decomp_decl_not_alone)
12221 << FirstDeclaratorInGroup->getSourceRange()
12222 << DD->getSourceRange();
12223 DiagnosedMultipleDecomps = true;
12226 // A declarator that uses 'auto' in any way other than to declare a
12227 // variable with a deduced type cannot be combined with any other
12228 // declarator in the same group.
12229 if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) {
12230 Diag(FirstNonDeducedAutoInGroup->getLocation(),
12231 diag::err_auto_non_deduced_not_alone)
12232 << FirstNonDeducedAutoInGroup->getType()
12233 ->hasAutoForTrailingReturnType()
12234 << FirstDeclaratorInGroup->getSourceRange()
12235 << DD->getSourceRange();
12236 DiagnosedNonDeducedAuto = true;
12241 Decls.push_back(D);
12245 if (DeclSpec::isDeclRep(DS.getTypeSpecType())) {
12246 if (TagDecl *Tag = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl())) {
12247 handleTagNumbering(Tag, S);
12248 if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() &&
12249 getLangOpts().CPlusPlus)
12250 Context.addDeclaratorForUnnamedTagDecl(Tag, FirstDeclaratorInGroup);
12254 return BuildDeclaratorGroup(Decls);
12257 /// BuildDeclaratorGroup - convert a list of declarations into a declaration
12258 /// group, performing any necessary semantic checking.
12259 Sema::DeclGroupPtrTy
12260 Sema::BuildDeclaratorGroup(MutableArrayRef<Decl *> Group) {
12261 // C++14 [dcl.spec.auto]p7: (DR1347)
12262 // If the type that replaces the placeholder type is not the same in each
12263 // deduction, the program is ill-formed.
12264 if (Group.size() > 1) {
12266 VarDecl *DeducedDecl = nullptr;
12267 for (unsigned i = 0, e = Group.size(); i != e; ++i) {
12268 VarDecl *D = dyn_cast<VarDecl>(Group[i]);
12269 if (!D || D->isInvalidDecl())
12271 DeducedType *DT = D->getType()->getContainedDeducedType();
12272 if (!DT || DT->getDeducedType().isNull())
12274 if (Deduced.isNull()) {
12275 Deduced = DT->getDeducedType();
12277 } else if (!Context.hasSameType(DT->getDeducedType(), Deduced)) {
12278 auto *AT = dyn_cast<AutoType>(DT);
12279 Diag(D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
12280 diag::err_auto_different_deductions)
12281 << (AT ? (unsigned)AT->getKeyword() : 3)
12282 << Deduced << DeducedDecl->getDeclName()
12283 << DT->getDeducedType() << D->getDeclName()
12284 << DeducedDecl->getInit()->getSourceRange()
12285 << D->getInit()->getSourceRange();
12286 D->setInvalidDecl();
12292 ActOnDocumentableDecls(Group);
12294 return DeclGroupPtrTy::make(
12295 DeclGroupRef::Create(Context, Group.data(), Group.size()));
12298 void Sema::ActOnDocumentableDecl(Decl *D) {
12299 ActOnDocumentableDecls(D);
12302 void Sema::ActOnDocumentableDecls(ArrayRef<Decl *> Group) {
12303 // Don't parse the comment if Doxygen diagnostics are ignored.
12304 if (Group.empty() || !Group[0])
12307 if (Diags.isIgnored(diag::warn_doc_param_not_found,
12308 Group[0]->getLocation()) &&
12309 Diags.isIgnored(diag::warn_unknown_comment_command_name,
12310 Group[0]->getLocation()))
12313 if (Group.size() >= 2) {
12314 // This is a decl group. Normally it will contain only declarations
12315 // produced from declarator list. But in case we have any definitions or
12316 // additional declaration references:
12317 // 'typedef struct S {} S;'
12318 // 'typedef struct S *S;'
12320 // FinalizeDeclaratorGroup adds these as separate declarations.
12321 Decl *MaybeTagDecl = Group[0];
12322 if (MaybeTagDecl && isa<TagDecl>(MaybeTagDecl)) {
12323 Group = Group.slice(1);
12327 // See if there are any new comments that are not attached to a decl.
12328 ArrayRef<RawComment *> Comments = Context.getRawCommentList().getComments();
12329 if (!Comments.empty() &&
12330 !Comments.back()->isAttached()) {
12331 // There is at least one comment that not attached to a decl.
12332 // Maybe it should be attached to one of these decls?
12334 // Note that this way we pick up not only comments that precede the
12335 // declaration, but also comments that *follow* the declaration -- thanks to
12336 // the lookahead in the lexer: we've consumed the semicolon and looked
12337 // ahead through comments.
12338 for (unsigned i = 0, e = Group.size(); i != e; ++i)
12339 Context.getCommentForDecl(Group[i], &PP);
12343 /// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
12344 /// to introduce parameters into function prototype scope.
12345 Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
12346 const DeclSpec &DS = D.getDeclSpec();
12348 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
12350 // C++03 [dcl.stc]p2 also permits 'auto'.
12351 StorageClass SC = SC_None;
12352 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
12354 // In C++11, the 'register' storage class specifier is deprecated.
12355 // In C++17, it is not allowed, but we tolerate it as an extension.
12356 if (getLangOpts().CPlusPlus11) {
12357 Diag(DS.getStorageClassSpecLoc(),
12358 getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
12359 : diag::warn_deprecated_register)
12360 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
12362 } else if (getLangOpts().CPlusPlus &&
12363 DS.getStorageClassSpec() == DeclSpec::SCS_auto) {
12365 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
12366 Diag(DS.getStorageClassSpecLoc(),
12367 diag::err_invalid_storage_class_in_func_decl);
12368 D.getMutableDeclSpec().ClearStorageClassSpecs();
12371 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
12372 Diag(DS.getThreadStorageClassSpecLoc(), diag::err_invalid_thread)
12373 << DeclSpec::getSpecifierName(TSCS);
12374 if (DS.isInlineSpecified())
12375 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
12376 << getLangOpts().CPlusPlus17;
12377 if (DS.isConstexprSpecified())
12378 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr)
12381 DiagnoseFunctionSpecifiers(DS);
12383 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
12384 QualType parmDeclType = TInfo->getType();
12386 if (getLangOpts().CPlusPlus) {
12387 // Check that there are no default arguments inside the type of this
12389 CheckExtraCXXDefaultArguments(D);
12391 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
12392 if (D.getCXXScopeSpec().isSet()) {
12393 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator)
12394 << D.getCXXScopeSpec().getRange();
12395 D.getCXXScopeSpec().clear();
12399 // Ensure we have a valid name
12400 IdentifierInfo *II = nullptr;
12402 II = D.getIdentifier();
12404 Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name)
12405 << GetNameForDeclarator(D).getName();
12406 D.setInvalidType(true);
12410 // Check for redeclaration of parameters, e.g. int foo(int x, int x);
12412 LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName,
12413 ForVisibleRedeclaration);
12415 if (R.isSingleResult()) {
12416 NamedDecl *PrevDecl = R.getFoundDecl();
12417 if (PrevDecl->isTemplateParameter()) {
12418 // Maybe we will complain about the shadowed template parameter.
12419 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
12420 // Just pretend that we didn't see the previous declaration.
12421 PrevDecl = nullptr;
12422 } else if (S->isDeclScope(PrevDecl)) {
12423 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II;
12424 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
12426 // Recover by removing the name
12428 D.SetIdentifier(nullptr, D.getIdentifierLoc());
12429 D.setInvalidType(true);
12434 // Temporarily put parameter variables in the translation unit, not
12435 // the enclosing context. This prevents them from accidentally
12436 // looking like class members in C++.
12438 CheckParameter(Context.getTranslationUnitDecl(), D.getBeginLoc(),
12439 D.getIdentifierLoc(), II, parmDeclType, TInfo, SC);
12441 if (D.isInvalidType())
12442 New->setInvalidDecl();
12444 assert(S->isFunctionPrototypeScope());
12445 assert(S->getFunctionPrototypeDepth() >= 1);
12446 New->setScopeInfo(S->getFunctionPrototypeDepth() - 1,
12447 S->getNextFunctionPrototypeIndex());
12449 // Add the parameter declaration into this scope.
12452 IdResolver.AddDecl(New);
12454 ProcessDeclAttributes(S, New, D);
12456 if (D.getDeclSpec().isModulePrivateSpecified())
12457 Diag(New->getLocation(), diag::err_module_private_local)
12458 << 1 << New->getDeclName()
12459 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
12460 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
12462 if (New->hasAttr<BlocksAttr>()) {
12463 Diag(New->getLocation(), diag::err_block_on_nonlocal);
12468 /// Synthesizes a variable for a parameter arising from a
12470 ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
12471 SourceLocation Loc,
12473 /* FIXME: setting StartLoc == Loc.
12474 Would it be worth to modify callers so as to provide proper source
12475 location for the unnamed parameters, embedding the parameter's type? */
12476 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, Loc, Loc, nullptr,
12477 T, Context.getTrivialTypeSourceInfo(T, Loc),
12479 Param->setImplicit();
12483 void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) {
12484 // Don't diagnose unused-parameter errors in template instantiations; we
12485 // will already have done so in the template itself.
12486 if (inTemplateInstantiation())
12489 for (const ParmVarDecl *Parameter : Parameters) {
12490 if (!Parameter->isReferenced() && Parameter->getDeclName() &&
12491 !Parameter->hasAttr<UnusedAttr>()) {
12492 Diag(Parameter->getLocation(), diag::warn_unused_parameter)
12493 << Parameter->getDeclName();
12498 void Sema::DiagnoseSizeOfParametersAndReturnValue(
12499 ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) {
12500 if (LangOpts.NumLargeByValueCopy == 0) // No check.
12503 // Warn if the return value is pass-by-value and larger than the specified
12505 if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) {
12506 unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity();
12507 if (Size > LangOpts.NumLargeByValueCopy)
12508 Diag(D->getLocation(), diag::warn_return_value_size)
12509 << D->getDeclName() << Size;
12512 // Warn if any parameter is pass-by-value and larger than the specified
12514 for (const ParmVarDecl *Parameter : Parameters) {
12515 QualType T = Parameter->getType();
12516 if (T->isDependentType() || !T.isPODType(Context))
12518 unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
12519 if (Size > LangOpts.NumLargeByValueCopy)
12520 Diag(Parameter->getLocation(), diag::warn_parameter_size)
12521 << Parameter->getDeclName() << Size;
12525 ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc,
12526 SourceLocation NameLoc, IdentifierInfo *Name,
12527 QualType T, TypeSourceInfo *TSInfo,
12529 // In ARC, infer a lifetime qualifier for appropriate parameter types.
12530 if (getLangOpts().ObjCAutoRefCount &&
12531 T.getObjCLifetime() == Qualifiers::OCL_None &&
12532 T->isObjCLifetimeType()) {
12534 Qualifiers::ObjCLifetime lifetime;
12536 // Special cases for arrays:
12537 // - if it's const, use __unsafe_unretained
12538 // - otherwise, it's an error
12539 if (T->isArrayType()) {
12540 if (!T.isConstQualified()) {
12541 DelayedDiagnostics.add(
12542 sema::DelayedDiagnostic::makeForbiddenType(
12543 NameLoc, diag::err_arc_array_param_no_ownership, T, false));
12545 lifetime = Qualifiers::OCL_ExplicitNone;
12547 lifetime = T->getObjCARCImplicitLifetime();
12549 T = Context.getLifetimeQualifiedType(T, lifetime);
12552 ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name,
12553 Context.getAdjustedParameterType(T),
12554 TSInfo, SC, nullptr);
12556 // Parameters can not be abstract class types.
12557 // For record types, this is done by the AbstractClassUsageDiagnoser once
12558 // the class has been completely parsed.
12559 if (!CurContext->isRecord() &&
12560 RequireNonAbstractType(NameLoc, T, diag::err_abstract_type_in_decl,
12561 AbstractParamType))
12562 New->setInvalidDecl();
12564 // Parameter declarators cannot be interface types. All ObjC objects are
12565 // passed by reference.
12566 if (T->isObjCObjectType()) {
12567 SourceLocation TypeEndLoc =
12568 getLocForEndOfToken(TSInfo->getTypeLoc().getEndLoc());
12570 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T
12571 << FixItHint::CreateInsertion(TypeEndLoc, "*");
12572 T = Context.getObjCObjectPointerType(T);
12576 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
12577 // duration shall not be qualified by an address-space qualifier."
12578 // Since all parameters have automatic store duration, they can not have
12579 // an address space.
12580 if (T.getAddressSpace() != LangAS::Default &&
12581 // OpenCL allows function arguments declared to be an array of a type
12582 // to be qualified with an address space.
12583 !(getLangOpts().OpenCL &&
12584 (T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private))) {
12585 Diag(NameLoc, diag::err_arg_with_address_space);
12586 New->setInvalidDecl();
12592 void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
12593 SourceLocation LocAfterDecls) {
12594 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
12596 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
12597 // for a K&R function.
12598 if (!FTI.hasPrototype) {
12599 for (int i = FTI.NumParams; i != 0; /* decrement in loop */) {
12601 if (FTI.Params[i].Param == nullptr) {
12602 SmallString<256> Code;
12603 llvm::raw_svector_ostream(Code)
12604 << " int " << FTI.Params[i].Ident->getName() << ";\n";
12605 Diag(FTI.Params[i].IdentLoc, diag::ext_param_not_declared)
12606 << FTI.Params[i].Ident
12607 << FixItHint::CreateInsertion(LocAfterDecls, Code);
12609 // Implicitly declare the argument as type 'int' for lack of a better
12611 AttributeFactory attrs;
12612 DeclSpec DS(attrs);
12613 const char* PrevSpec; // unused
12614 unsigned DiagID; // unused
12615 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.Params[i].IdentLoc, PrevSpec,
12616 DiagID, Context.getPrintingPolicy());
12617 // Use the identifier location for the type source range.
12618 DS.SetRangeStart(FTI.Params[i].IdentLoc);
12619 DS.SetRangeEnd(FTI.Params[i].IdentLoc);
12620 Declarator ParamD(DS, DeclaratorContext::KNRTypeListContext);
12621 ParamD.SetIdentifier(FTI.Params[i].Ident, FTI.Params[i].IdentLoc);
12622 FTI.Params[i].Param = ActOnParamDeclarator(S, ParamD);
12629 Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D,
12630 MultiTemplateParamsArg TemplateParameterLists,
12631 SkipBodyInfo *SkipBody) {
12632 assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
12633 assert(D.isFunctionDeclarator() && "Not a function declarator!");
12634 Scope *ParentScope = FnBodyScope->getParent();
12636 D.setFunctionDefinitionKind(FDK_Definition);
12637 Decl *DP = HandleDeclarator(ParentScope, D, TemplateParameterLists);
12638 return ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody);
12641 void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) {
12642 Consumer.HandleInlineFunctionDefinition(D);
12645 static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD,
12646 const FunctionDecl*& PossibleZeroParamPrototype) {
12647 // Don't warn about invalid declarations.
12648 if (FD->isInvalidDecl())
12651 // Or declarations that aren't global.
12652 if (!FD->isGlobal())
12655 // Don't warn about C++ member functions.
12656 if (isa<CXXMethodDecl>(FD))
12659 // Don't warn about 'main'.
12663 // Don't warn about inline functions.
12664 if (FD->isInlined())
12667 // Don't warn about function templates.
12668 if (FD->getDescribedFunctionTemplate())
12671 // Don't warn about function template specializations.
12672 if (FD->isFunctionTemplateSpecialization())
12675 // Don't warn for OpenCL kernels.
12676 if (FD->hasAttr<OpenCLKernelAttr>())
12679 // Don't warn on explicitly deleted functions.
12680 if (FD->isDeleted())
12683 bool MissingPrototype = true;
12684 for (const FunctionDecl *Prev = FD->getPreviousDecl();
12685 Prev; Prev = Prev->getPreviousDecl()) {
12686 // Ignore any declarations that occur in function or method
12687 // scope, because they aren't visible from the header.
12688 if (Prev->getLexicalDeclContext()->isFunctionOrMethod())
12691 MissingPrototype = !Prev->getType()->isFunctionProtoType();
12692 if (FD->getNumParams() == 0)
12693 PossibleZeroParamPrototype = Prev;
12697 return MissingPrototype;
12701 Sema::CheckForFunctionRedefinition(FunctionDecl *FD,
12702 const FunctionDecl *EffectiveDefinition,
12703 SkipBodyInfo *SkipBody) {
12704 const FunctionDecl *Definition = EffectiveDefinition;
12705 if (!Definition && !FD->isDefined(Definition) && !FD->isCXXClassMember()) {
12706 // If this is a friend function defined in a class template, it does not
12707 // have a body until it is used, nevertheless it is a definition, see
12710 // ... for the purpose of determining whether an instantiated redeclaration
12711 // is valid according to [basic.def.odr] and [class.mem], a declaration that
12712 // corresponds to a definition in the template is considered to be a
12715 // The following code must produce redefinition error:
12717 // template<typename T> struct C20 { friend void func_20() {} };
12719 // void func_20() {}
12721 for (auto I : FD->redecls()) {
12722 if (I != FD && !I->isInvalidDecl() &&
12723 I->getFriendObjectKind() != Decl::FOK_None) {
12724 if (FunctionDecl *Original = I->getInstantiatedFromMemberFunction()) {
12725 if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) {
12726 // A merged copy of the same function, instantiated as a member of
12727 // the same class, is OK.
12728 if (declaresSameEntity(OrigFD, Original) &&
12729 declaresSameEntity(cast<Decl>(I->getLexicalDeclContext()),
12730 cast<Decl>(FD->getLexicalDeclContext())))
12734 if (Original->isThisDeclarationADefinition()) {
12744 // Similar to friend functions a friend function template may be a
12745 // definition and do not have a body if it is instantiated in a class
12747 if (FunctionTemplateDecl *FTD = FD->getDescribedFunctionTemplate()) {
12748 for (auto I : FTD->redecls()) {
12749 auto D = cast<FunctionTemplateDecl>(I);
12751 assert(!D->isThisDeclarationADefinition() &&
12752 "More than one definition in redeclaration chain");
12753 if (D->getFriendObjectKind() != Decl::FOK_None)
12754 if (FunctionTemplateDecl *FT =
12755 D->getInstantiatedFromMemberTemplate()) {
12756 if (FT->isThisDeclarationADefinition()) {
12757 Definition = D->getTemplatedDecl();
12768 if (canRedefineFunction(Definition, getLangOpts()))
12771 // Don't emit an error when this is redefinition of a typo-corrected
12773 if (TypoCorrectedFunctionDefinitions.count(Definition))
12776 // If we don't have a visible definition of the function, and it's inline or
12777 // a template, skip the new definition.
12778 if (SkipBody && !hasVisibleDefinition(Definition) &&
12779 (Definition->getFormalLinkage() == InternalLinkage ||
12780 Definition->isInlined() ||
12781 Definition->getDescribedFunctionTemplate() ||
12782 Definition->getNumTemplateParameterLists())) {
12783 SkipBody->ShouldSkip = true;
12784 SkipBody->Previous = const_cast<FunctionDecl*>(Definition);
12785 if (auto *TD = Definition->getDescribedFunctionTemplate())
12786 makeMergedDefinitionVisible(TD);
12787 makeMergedDefinitionVisible(const_cast<FunctionDecl*>(Definition));
12791 if (getLangOpts().GNUMode && Definition->isInlineSpecified() &&
12792 Definition->getStorageClass() == SC_Extern)
12793 Diag(FD->getLocation(), diag::err_redefinition_extern_inline)
12794 << FD->getDeclName() << getLangOpts().CPlusPlus;
12796 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName();
12798 Diag(Definition->getLocation(), diag::note_previous_definition);
12799 FD->setInvalidDecl();
12802 static void RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator,
12804 CXXRecordDecl *const LambdaClass = CallOperator->getParent();
12806 LambdaScopeInfo *LSI = S.PushLambdaScope();
12807 LSI->CallOperator = CallOperator;
12808 LSI->Lambda = LambdaClass;
12809 LSI->ReturnType = CallOperator->getReturnType();
12810 const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault();
12812 if (LCD == LCD_None)
12813 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None;
12814 else if (LCD == LCD_ByCopy)
12815 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval;
12816 else if (LCD == LCD_ByRef)
12817 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref;
12818 DeclarationNameInfo DNI = CallOperator->getNameInfo();
12820 LSI->IntroducerRange = DNI.getCXXOperatorNameRange();
12821 LSI->Mutable = !CallOperator->isConst();
12823 // Add the captures to the LSI so they can be noted as already
12824 // captured within tryCaptureVar.
12825 auto I = LambdaClass->field_begin();
12826 for (const auto &C : LambdaClass->captures()) {
12827 if (C.capturesVariable()) {
12828 VarDecl *VD = C.getCapturedVar();
12829 if (VD->isInitCapture())
12830 S.CurrentInstantiationScope->InstantiatedLocal(VD, VD);
12831 QualType CaptureType = VD->getType();
12832 const bool ByRef = C.getCaptureKind() == LCK_ByRef;
12833 LSI->addCapture(VD, /*IsBlock*/false, ByRef,
12834 /*RefersToEnclosingVariableOrCapture*/true, C.getLocation(),
12835 /*EllipsisLoc*/C.isPackExpansion()
12836 ? C.getEllipsisLoc() : SourceLocation(),
12837 CaptureType, /*Expr*/ nullptr);
12839 } else if (C.capturesThis()) {
12840 LSI->addThisCapture(/*Nested*/ false, C.getLocation(),
12842 C.getCaptureKind() == LCK_StarThis);
12844 LSI->addVLATypeCapture(C.getLocation(), I->getType());
12850 Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
12851 SkipBodyInfo *SkipBody) {
12853 // Parsing the function declaration failed in some way. Push on a fake scope
12854 // anyway so we can try to parse the function body.
12855 PushFunctionScope();
12856 PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
12860 FunctionDecl *FD = nullptr;
12862 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
12863 FD = FunTmpl->getTemplatedDecl();
12865 FD = cast<FunctionDecl>(D);
12867 // Do not push if it is a lambda because one is already pushed when building
12868 // the lambda in ActOnStartOfLambdaDefinition().
12869 if (!isLambdaCallOperator(FD))
12870 PushExpressionEvaluationContext(ExprEvalContexts.back().Context);
12872 // Check for defining attributes before the check for redefinition.
12873 if (const auto *Attr = FD->getAttr<AliasAttr>()) {
12874 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0;
12875 FD->dropAttr<AliasAttr>();
12876 FD->setInvalidDecl();
12878 if (const auto *Attr = FD->getAttr<IFuncAttr>()) {
12879 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 1;
12880 FD->dropAttr<IFuncAttr>();
12881 FD->setInvalidDecl();
12884 // See if this is a redefinition. If 'will have body' is already set, then
12885 // these checks were already performed when it was set.
12886 if (!FD->willHaveBody() && !FD->isLateTemplateParsed()) {
12887 CheckForFunctionRedefinition(FD, nullptr, SkipBody);
12889 // If we're skipping the body, we're done. Don't enter the scope.
12890 if (SkipBody && SkipBody->ShouldSkip)
12894 // Mark this function as "will have a body eventually". This lets users to
12895 // call e.g. isInlineDefinitionExternallyVisible while we're still parsing
12897 FD->setWillHaveBody();
12899 // If we are instantiating a generic lambda call operator, push
12900 // a LambdaScopeInfo onto the function stack. But use the information
12901 // that's already been calculated (ActOnLambdaExpr) to prime the current
12902 // LambdaScopeInfo.
12903 // When the template operator is being specialized, the LambdaScopeInfo,
12904 // has to be properly restored so that tryCaptureVariable doesn't try
12905 // and capture any new variables. In addition when calculating potential
12906 // captures during transformation of nested lambdas, it is necessary to
12907 // have the LSI properly restored.
12908 if (isGenericLambdaCallOperatorSpecialization(FD)) {
12909 assert(inTemplateInstantiation() &&
12910 "There should be an active template instantiation on the stack "
12911 "when instantiating a generic lambda!");
12912 RebuildLambdaScopeInfo(cast<CXXMethodDecl>(D), *this);
12914 // Enter a new function scope
12915 PushFunctionScope();
12918 // Builtin functions cannot be defined.
12919 if (unsigned BuiltinID = FD->getBuiltinID()) {
12920 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID) &&
12921 !Context.BuiltinInfo.isPredefinedRuntimeFunction(BuiltinID)) {
12922 Diag(FD->getLocation(), diag::err_builtin_definition) << FD;
12923 FD->setInvalidDecl();
12927 // The return type of a function definition must be complete
12928 // (C99 6.9.1p3, C++ [dcl.fct]p6).
12929 QualType ResultType = FD->getReturnType();
12930 if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
12931 !FD->isInvalidDecl() &&
12932 RequireCompleteType(FD->getLocation(), ResultType,
12933 diag::err_func_def_incomplete_result))
12934 FD->setInvalidDecl();
12937 PushDeclContext(FnBodyScope, FD);
12939 // Check the validity of our function parameters
12940 CheckParmsForFunctionDef(FD->parameters(),
12941 /*CheckParameterNames=*/true);
12943 // Add non-parameter declarations already in the function to the current
12946 for (Decl *NPD : FD->decls()) {
12947 auto *NonParmDecl = dyn_cast<NamedDecl>(NPD);
12950 assert(!isa<ParmVarDecl>(NonParmDecl) &&
12951 "parameters should not be in newly created FD yet");
12953 // If the decl has a name, make it accessible in the current scope.
12954 if (NonParmDecl->getDeclName())
12955 PushOnScopeChains(NonParmDecl, FnBodyScope, /*AddToContext=*/false);
12957 // Similarly, dive into enums and fish their constants out, making them
12958 // accessible in this scope.
12959 if (auto *ED = dyn_cast<EnumDecl>(NonParmDecl)) {
12960 for (auto *EI : ED->enumerators())
12961 PushOnScopeChains(EI, FnBodyScope, /*AddToContext=*/false);
12966 // Introduce our parameters into the function scope
12967 for (auto Param : FD->parameters()) {
12968 Param->setOwningFunction(FD);
12970 // If this has an identifier, add it to the scope stack.
12971 if (Param->getIdentifier() && FnBodyScope) {
12972 CheckShadow(FnBodyScope, Param);
12974 PushOnScopeChains(Param, FnBodyScope);
12978 // Ensure that the function's exception specification is instantiated.
12979 if (const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>())
12980 ResolveExceptionSpec(D->getLocation(), FPT);
12982 // dllimport cannot be applied to non-inline function definitions.
12983 if (FD->hasAttr<DLLImportAttr>() && !FD->isInlined() &&
12984 !FD->isTemplateInstantiation()) {
12985 assert(!FD->hasAttr<DLLExportAttr>());
12986 Diag(FD->getLocation(), diag::err_attribute_dllimport_function_definition);
12987 FD->setInvalidDecl();
12990 // We want to attach documentation to original Decl (which might be
12991 // a function template).
12992 ActOnDocumentableDecl(D);
12993 if (getCurLexicalContext()->isObjCContainer() &&
12994 getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl &&
12995 getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
12996 Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
13001 /// Given the set of return statements within a function body,
13002 /// compute the variables that are subject to the named return value
13005 /// Each of the variables that is subject to the named return value
13006 /// optimization will be marked as NRVO variables in the AST, and any
13007 /// return statement that has a marked NRVO variable as its NRVO candidate can
13008 /// use the named return value optimization.
13010 /// This function applies a very simplistic algorithm for NRVO: if every return
13011 /// statement in the scope of a variable has the same NRVO candidate, that
13012 /// candidate is an NRVO variable.
13013 void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) {
13014 ReturnStmt **Returns = Scope->Returns.data();
13016 for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) {
13017 if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) {
13018 if (!NRVOCandidate->isNRVOVariable())
13019 Returns[I]->setNRVOCandidate(nullptr);
13024 bool Sema::canDelayFunctionBody(const Declarator &D) {
13025 // We can't delay parsing the body of a constexpr function template (yet).
13026 if (D.getDeclSpec().isConstexprSpecified())
13029 // We can't delay parsing the body of a function template with a deduced
13030 // return type (yet).
13031 if (D.getDeclSpec().hasAutoTypeSpec()) {
13032 // If the placeholder introduces a non-deduced trailing return type,
13033 // we can still delay parsing it.
13034 if (D.getNumTypeObjects()) {
13035 const auto &Outer = D.getTypeObject(D.getNumTypeObjects() - 1);
13036 if (Outer.Kind == DeclaratorChunk::Function &&
13037 Outer.Fun.hasTrailingReturnType()) {
13038 QualType Ty = GetTypeFromParser(Outer.Fun.getTrailingReturnType());
13039 return Ty.isNull() || !Ty->isUndeducedType();
13048 bool Sema::canSkipFunctionBody(Decl *D) {
13049 // We cannot skip the body of a function (or function template) which is
13050 // constexpr, since we may need to evaluate its body in order to parse the
13051 // rest of the file.
13052 // We cannot skip the body of a function with an undeduced return type,
13053 // because any callers of that function need to know the type.
13054 if (const FunctionDecl *FD = D->getAsFunction()) {
13055 if (FD->isConstexpr())
13057 // We can't simply call Type::isUndeducedType here, because inside template
13058 // auto can be deduced to a dependent type, which is not considered
13060 if (FD->getReturnType()->getContainedDeducedType())
13063 return Consumer.shouldSkipFunctionBody(D);
13066 Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) {
13069 if (FunctionDecl *FD = Decl->getAsFunction())
13070 FD->setHasSkippedBody();
13071 else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Decl))
13072 MD->setHasSkippedBody();
13076 Decl *Sema::ActOnFinishFunctionBody(Decl *D, Stmt *BodyArg) {
13077 return ActOnFinishFunctionBody(D, BodyArg, false);
13080 /// RAII object that pops an ExpressionEvaluationContext when exiting a function
13082 class ExitFunctionBodyRAII {
13084 ExitFunctionBodyRAII(Sema &S, bool IsLambda) : S(S), IsLambda(IsLambda) {}
13085 ~ExitFunctionBodyRAII() {
13087 S.PopExpressionEvaluationContext();
13092 bool IsLambda = false;
13095 Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
13096 bool IsInstantiation) {
13097 FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
13099 sema::AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy();
13100 sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr;
13102 if (getLangOpts().CoroutinesTS && getCurFunction()->isCoroutine())
13103 CheckCompletedCoroutineBody(FD, Body);
13105 // Do not call PopExpressionEvaluationContext() if it is a lambda because one
13106 // is already popped when finishing the lambda in BuildLambdaExpr(). This is
13107 // meant to pop the context added in ActOnStartOfFunctionDef().
13108 ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD));
13112 FD->setWillHaveBody(false);
13114 if (getLangOpts().CPlusPlus14) {
13115 if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() &&
13116 FD->getReturnType()->isUndeducedType()) {
13117 // If the function has a deduced result type but contains no 'return'
13118 // statements, the result type as written must be exactly 'auto', and
13119 // the deduced result type is 'void'.
13120 if (!FD->getReturnType()->getAs<AutoType>()) {
13121 Diag(dcl->getLocation(), diag::err_auto_fn_no_return_but_not_auto)
13122 << FD->getReturnType();
13123 FD->setInvalidDecl();
13125 // Substitute 'void' for the 'auto' in the type.
13126 TypeLoc ResultType = getReturnTypeLoc(FD);
13127 Context.adjustDeducedFunctionResultType(
13128 FD, SubstAutoType(ResultType.getType(), Context.VoidTy));
13131 } else if (getLangOpts().CPlusPlus11 && isLambdaCallOperator(FD)) {
13132 // In C++11, we don't use 'auto' deduction rules for lambda call
13133 // operators because we don't support return type deduction.
13134 auto *LSI = getCurLambda();
13135 if (LSI->HasImplicitReturnType) {
13136 deduceClosureReturnType(*LSI);
13138 // C++11 [expr.prim.lambda]p4:
13139 // [...] if there are no return statements in the compound-statement
13140 // [the deduced type is] the type void
13142 LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType;
13144 // Update the return type to the deduced type.
13145 const FunctionProtoType *Proto =
13146 FD->getType()->getAs<FunctionProtoType>();
13147 FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(),
13148 Proto->getExtProtoInfo()));
13152 // If the function implicitly returns zero (like 'main') or is naked,
13153 // don't complain about missing return statements.
13154 if (FD->hasImplicitReturnZero() || FD->hasAttr<NakedAttr>())
13155 WP.disableCheckFallThrough();
13157 // MSVC permits the use of pure specifier (=0) on function definition,
13158 // defined at class scope, warn about this non-standard construct.
13159 if (getLangOpts().MicrosoftExt && FD->isPure() && FD->isCanonicalDecl())
13160 Diag(FD->getLocation(), diag::ext_pure_function_definition);
13162 if (!FD->isInvalidDecl()) {
13163 // Don't diagnose unused parameters of defaulted or deleted functions.
13164 if (!FD->isDeleted() && !FD->isDefaulted() && !FD->hasSkippedBody())
13165 DiagnoseUnusedParameters(FD->parameters());
13166 DiagnoseSizeOfParametersAndReturnValue(FD->parameters(),
13167 FD->getReturnType(), FD);
13169 // If this is a structor, we need a vtable.
13170 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(FD))
13171 MarkVTableUsed(FD->getLocation(), Constructor->getParent());
13172 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(FD))
13173 MarkVTableUsed(FD->getLocation(), Destructor->getParent());
13175 // Try to apply the named return value optimization. We have to check
13176 // if we can do this here because lambdas keep return statements around
13177 // to deduce an implicit return type.
13178 if (FD->getReturnType()->isRecordType() &&
13179 (!getLangOpts().CPlusPlus || !FD->isDependentContext()))
13180 computeNRVO(Body, getCurFunction());
13183 // GNU warning -Wmissing-prototypes:
13184 // Warn if a global function is defined without a previous
13185 // prototype declaration. This warning is issued even if the
13186 // definition itself provides a prototype. The aim is to detect
13187 // global functions that fail to be declared in header files.
13188 const FunctionDecl *PossibleZeroParamPrototype = nullptr;
13189 if (ShouldWarnAboutMissingPrototype(FD, PossibleZeroParamPrototype)) {
13190 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD;
13192 if (PossibleZeroParamPrototype) {
13193 // We found a declaration that is not a prototype,
13194 // but that could be a zero-parameter prototype
13195 if (TypeSourceInfo *TI =
13196 PossibleZeroParamPrototype->getTypeSourceInfo()) {
13197 TypeLoc TL = TI->getTypeLoc();
13198 if (FunctionNoProtoTypeLoc FTL = TL.getAs<FunctionNoProtoTypeLoc>())
13199 Diag(PossibleZeroParamPrototype->getLocation(),
13200 diag::note_declaration_not_a_prototype)
13201 << PossibleZeroParamPrototype
13202 << FixItHint::CreateInsertion(FTL.getRParenLoc(), "void");
13206 // GNU warning -Wstrict-prototypes
13207 // Warn if K&R function is defined without a previous declaration.
13208 // This warning is issued only if the definition itself does not provide
13209 // a prototype. Only K&R definitions do not provide a prototype.
13210 // An empty list in a function declarator that is part of a definition
13211 // of that function specifies that the function has no parameters
13212 // (C99 6.7.5.3p14)
13213 if (!FD->hasWrittenPrototype() && FD->getNumParams() > 0 &&
13214 !LangOpts.CPlusPlus) {
13215 TypeSourceInfo *TI = FD->getTypeSourceInfo();
13216 TypeLoc TL = TI->getTypeLoc();
13217 FunctionTypeLoc FTL = TL.getAsAdjusted<FunctionTypeLoc>();
13218 Diag(FTL.getLParenLoc(), diag::warn_strict_prototypes) << 2;
13222 // Warn on CPUDispatch with an actual body.
13223 if (FD->isMultiVersion() && FD->hasAttr<CPUDispatchAttr>() && Body)
13224 if (const auto *CmpndBody = dyn_cast<CompoundStmt>(Body))
13225 if (!CmpndBody->body_empty())
13226 Diag(CmpndBody->body_front()->getBeginLoc(),
13227 diag::warn_dispatch_body_ignored);
13229 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
13230 const CXXMethodDecl *KeyFunction;
13231 if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) &&
13233 (KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) &&
13234 MD == KeyFunction->getCanonicalDecl()) {
13235 // Update the key-function state if necessary for this ABI.
13236 if (FD->isInlined() &&
13237 !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
13238 Context.setNonKeyFunction(MD);
13240 // If the newly-chosen key function is already defined, then we
13241 // need to mark the vtable as used retroactively.
13242 KeyFunction = Context.getCurrentKeyFunction(MD->getParent());
13243 const FunctionDecl *Definition;
13244 if (KeyFunction && KeyFunction->isDefined(Definition))
13245 MarkVTableUsed(Definition->getLocation(), MD->getParent(), true);
13247 // We just defined they key function; mark the vtable as used.
13248 MarkVTableUsed(FD->getLocation(), MD->getParent(), true);
13253 assert((FD == getCurFunctionDecl() || getCurLambda()->CallOperator == FD) &&
13254 "Function parsing confused");
13255 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
13256 assert(MD == getCurMethodDecl() && "Method parsing confused");
13258 if (!MD->isInvalidDecl()) {
13259 if (!MD->hasSkippedBody())
13260 DiagnoseUnusedParameters(MD->parameters());
13261 DiagnoseSizeOfParametersAndReturnValue(MD->parameters(),
13262 MD->getReturnType(), MD);
13265 computeNRVO(Body, getCurFunction());
13267 if (getCurFunction()->ObjCShouldCallSuper) {
13268 Diag(MD->getEndLoc(), diag::warn_objc_missing_super_call)
13269 << MD->getSelector().getAsString();
13270 getCurFunction()->ObjCShouldCallSuper = false;
13272 if (getCurFunction()->ObjCWarnForNoDesignatedInitChain) {
13273 const ObjCMethodDecl *InitMethod = nullptr;
13274 bool isDesignated =
13275 MD->isDesignatedInitializerForTheInterface(&InitMethod);
13276 assert(isDesignated && InitMethod);
13277 (void)isDesignated;
13279 auto superIsNSObject = [&](const ObjCMethodDecl *MD) {
13280 auto IFace = MD->getClassInterface();
13283 auto SuperD = IFace->getSuperClass();
13286 return SuperD->getIdentifier() ==
13287 NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject);
13289 // Don't issue this warning for unavailable inits or direct subclasses
13291 if (!MD->isUnavailable() && !superIsNSObject(MD)) {
13292 Diag(MD->getLocation(),
13293 diag::warn_objc_designated_init_missing_super_call);
13294 Diag(InitMethod->getLocation(),
13295 diag::note_objc_designated_init_marked_here);
13297 getCurFunction()->ObjCWarnForNoDesignatedInitChain = false;
13299 if (getCurFunction()->ObjCWarnForNoInitDelegation) {
13300 // Don't issue this warning for unavaialable inits.
13301 if (!MD->isUnavailable())
13302 Diag(MD->getLocation(),
13303 diag::warn_objc_secondary_init_missing_init_call);
13304 getCurFunction()->ObjCWarnForNoInitDelegation = false;
13307 // Parsing the function declaration failed in some way. Pop the fake scope
13309 PopFunctionScopeInfo(ActivePolicy, dcl);
13313 if (Body && getCurFunction()->HasPotentialAvailabilityViolations)
13314 DiagnoseUnguardedAvailabilityViolations(dcl);
13316 assert(!getCurFunction()->ObjCShouldCallSuper &&
13317 "This should only be set for ObjC methods, which should have been "
13318 "handled in the block above.");
13320 // Verify and clean out per-function state.
13321 if (Body && (!FD || !FD->isDefaulted())) {
13322 // C++ constructors that have function-try-blocks can't have return
13323 // statements in the handlers of that block. (C++ [except.handle]p14)
13325 if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body))
13326 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body));
13328 // Verify that gotos and switch cases don't jump into scopes illegally.
13329 if (getCurFunction()->NeedsScopeChecking() &&
13330 !PP.isCodeCompletionEnabled())
13331 DiagnoseInvalidJumps(Body);
13333 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) {
13334 if (!Destructor->getParent()->isDependentType())
13335 CheckDestructor(Destructor);
13337 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
13338 Destructor->getParent());
13341 // If any errors have occurred, clear out any temporaries that may have
13342 // been leftover. This ensures that these temporaries won't be picked up for
13343 // deletion in some later function.
13344 if (getDiagnostics().hasErrorOccurred() ||
13345 getDiagnostics().getSuppressAllDiagnostics()) {
13346 DiscardCleanupsInEvaluationContext();
13348 if (!getDiagnostics().hasUncompilableErrorOccurred() &&
13349 !isa<FunctionTemplateDecl>(dcl)) {
13350 // Since the body is valid, issue any analysis-based warnings that are
13352 ActivePolicy = &WP;
13355 if (!IsInstantiation && FD && FD->isConstexpr() && !FD->isInvalidDecl() &&
13356 (!CheckConstexprFunctionDecl(FD) ||
13357 !CheckConstexprFunctionBody(FD, Body)))
13358 FD->setInvalidDecl();
13360 if (FD && FD->hasAttr<NakedAttr>()) {
13361 for (const Stmt *S : Body->children()) {
13362 // Allow local register variables without initializer as they don't
13363 // require prologue.
13364 bool RegisterVariables = false;
13365 if (auto *DS = dyn_cast<DeclStmt>(S)) {
13366 for (const auto *Decl : DS->decls()) {
13367 if (const auto *Var = dyn_cast<VarDecl>(Decl)) {
13368 RegisterVariables =
13369 Var->hasAttr<AsmLabelAttr>() && !Var->hasInit();
13370 if (!RegisterVariables)
13375 if (RegisterVariables)
13377 if (!isa<AsmStmt>(S) && !isa<NullStmt>(S)) {
13378 Diag(S->getBeginLoc(), diag::err_non_asm_stmt_in_naked_function);
13379 Diag(FD->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
13380 FD->setInvalidDecl();
13386 assert(ExprCleanupObjects.size() ==
13387 ExprEvalContexts.back().NumCleanupObjects &&
13388 "Leftover temporaries in function");
13389 assert(!Cleanup.exprNeedsCleanups() && "Unaccounted cleanups in function");
13390 assert(MaybeODRUseExprs.empty() &&
13391 "Leftover expressions for odr-use checking");
13394 if (!IsInstantiation)
13397 PopFunctionScopeInfo(ActivePolicy, dcl);
13398 // If any errors have occurred, clear out any temporaries that may have
13399 // been leftover. This ensures that these temporaries won't be picked up for
13400 // deletion in some later function.
13401 if (getDiagnostics().hasErrorOccurred()) {
13402 DiscardCleanupsInEvaluationContext();
13408 /// When we finish delayed parsing of an attribute, we must attach it to the
13410 void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
13411 ParsedAttributes &Attrs) {
13412 // Always attach attributes to the underlying decl.
13413 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
13414 D = TD->getTemplatedDecl();
13415 ProcessDeclAttributeList(S, D, Attrs);
13417 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(D))
13418 if (Method->isStatic())
13419 checkThisInStaticMemberFunctionAttributes(Method);
13422 /// ImplicitlyDefineFunction - An undeclared identifier was used in a function
13423 /// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
13424 NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
13425 IdentifierInfo &II, Scope *S) {
13426 // Find the scope in which the identifier is injected and the corresponding
13428 // FIXME: C89 does not say what happens if there is no enclosing block scope.
13429 // In that case, we inject the declaration into the translation unit scope
13431 Scope *BlockScope = S;
13432 while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent())
13433 BlockScope = BlockScope->getParent();
13435 Scope *ContextScope = BlockScope;
13436 while (!ContextScope->getEntity())
13437 ContextScope = ContextScope->getParent();
13438 ContextRAII SavedContext(*this, ContextScope->getEntity());
13440 // Before we produce a declaration for an implicitly defined
13441 // function, see whether there was a locally-scoped declaration of
13442 // this name as a function or variable. If so, use that
13443 // (non-visible) declaration, and complain about it.
13444 NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(&II);
13446 // We still need to inject the function into the enclosing block scope so
13447 // that later (non-call) uses can see it.
13448 PushOnScopeChains(ExternCPrev, BlockScope, /*AddToContext*/false);
13450 // C89 footnote 38:
13451 // If in fact it is not defined as having type "function returning int",
13452 // the behavior is undefined.
13453 if (!isa<FunctionDecl>(ExternCPrev) ||
13454 !Context.typesAreCompatible(
13455 cast<FunctionDecl>(ExternCPrev)->getType(),
13456 Context.getFunctionNoProtoType(Context.IntTy))) {
13457 Diag(Loc, diag::ext_use_out_of_scope_declaration)
13458 << ExternCPrev << !getLangOpts().C99;
13459 Diag(ExternCPrev->getLocation(), diag::note_previous_declaration);
13460 return ExternCPrev;
13464 // Extension in C99. Legal in C90, but warn about it.
13466 if (II.getName().startswith("__builtin_"))
13467 diag_id = diag::warn_builtin_unknown;
13468 // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported.
13469 else if (getLangOpts().OpenCL)
13470 diag_id = diag::err_opencl_implicit_function_decl;
13471 else if (getLangOpts().C99)
13472 diag_id = diag::ext_implicit_function_decl;
13474 diag_id = diag::warn_implicit_function_decl;
13475 Diag(Loc, diag_id) << &II;
13477 // If we found a prior declaration of this function, don't bother building
13478 // another one. We've already pushed that one into scope, so there's nothing
13481 return ExternCPrev;
13483 // Because typo correction is expensive, only do it if the implicit
13484 // function declaration is going to be treated as an error.
13485 if (Diags.getDiagnosticLevel(diag_id, Loc) >= DiagnosticsEngine::Error) {
13486 TypoCorrection Corrected;
13488 (Corrected = CorrectTypo(
13489 DeclarationNameInfo(&II, Loc), LookupOrdinaryName, S, nullptr,
13490 llvm::make_unique<DeclFilterCCC<FunctionDecl>>(), CTK_NonError)))
13491 diagnoseTypo(Corrected, PDiag(diag::note_function_suggestion),
13492 /*ErrorRecovery*/false);
13495 // Set a Declarator for the implicit definition: int foo();
13497 AttributeFactory attrFactory;
13498 DeclSpec DS(attrFactory);
13500 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID,
13501 Context.getPrintingPolicy());
13502 (void)Error; // Silence warning.
13503 assert(!Error && "Error setting up implicit decl!");
13504 SourceLocation NoLoc;
13505 Declarator D(DS, DeclaratorContext::BlockContext);
13506 D.AddTypeInfo(DeclaratorChunk::getFunction(/*HasProto=*/false,
13507 /*IsAmbiguous=*/false,
13508 /*LParenLoc=*/NoLoc,
13509 /*Params=*/nullptr,
13511 /*EllipsisLoc=*/NoLoc,
13512 /*RParenLoc=*/NoLoc,
13513 /*RefQualifierIsLvalueRef=*/true,
13514 /*RefQualifierLoc=*/NoLoc,
13515 /*MutableLoc=*/NoLoc, EST_None,
13516 /*ESpecRange=*/SourceRange(),
13517 /*Exceptions=*/nullptr,
13518 /*ExceptionRanges=*/nullptr,
13519 /*NumExceptions=*/0,
13520 /*NoexceptExpr=*/nullptr,
13521 /*ExceptionSpecTokens=*/nullptr,
13522 /*DeclsInPrototype=*/None, Loc,
13524 std::move(DS.getAttributes()), SourceLocation());
13525 D.SetIdentifier(&II, Loc);
13527 // Insert this function into the enclosing block scope.
13528 FunctionDecl *FD = cast<FunctionDecl>(ActOnDeclarator(BlockScope, D));
13531 AddKnownFunctionAttributes(FD);
13536 /// Adds any function attributes that we know a priori based on
13537 /// the declaration of this function.
13539 /// These attributes can apply both to implicitly-declared builtins
13540 /// (like __builtin___printf_chk) or to library-declared functions
13541 /// like NSLog or printf.
13543 /// We need to check for duplicate attributes both here and where user-written
13544 /// attributes are applied to declarations.
13545 void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
13546 if (FD->isInvalidDecl())
13549 // If this is a built-in function, map its builtin attributes to
13550 // actual attributes.
13551 if (unsigned BuiltinID = FD->getBuiltinID()) {
13552 // Handle printf-formatting attributes.
13553 unsigned FormatIdx;
13555 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) {
13556 if (!FD->hasAttr<FormatAttr>()) {
13557 const char *fmt = "printf";
13558 unsigned int NumParams = FD->getNumParams();
13559 if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf)
13560 FD->getParamDecl(FormatIdx)->getType()->isObjCObjectPointerType())
13562 FD->addAttr(FormatAttr::CreateImplicit(Context,
13563 &Context.Idents.get(fmt),
13565 HasVAListArg ? 0 : FormatIdx+2,
13566 FD->getLocation()));
13569 if (Context.BuiltinInfo.isScanfLike(BuiltinID, FormatIdx,
13571 if (!FD->hasAttr<FormatAttr>())
13572 FD->addAttr(FormatAttr::CreateImplicit(Context,
13573 &Context.Idents.get("scanf"),
13575 HasVAListArg ? 0 : FormatIdx+2,
13576 FD->getLocation()));
13579 // Mark const if we don't care about errno and that is the only thing
13580 // preventing the function from being const. This allows IRgen to use LLVM
13581 // intrinsics for such functions.
13582 if (!getLangOpts().MathErrno && !FD->hasAttr<ConstAttr>() &&
13583 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID))
13584 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13586 // We make "fma" on some platforms const because we know it does not set
13587 // errno in those environments even though it could set errno based on the
13589 const llvm::Triple &Trip = Context.getTargetInfo().getTriple();
13590 if ((Trip.isGNUEnvironment() || Trip.isAndroid() || Trip.isOSMSVCRT()) &&
13591 !FD->hasAttr<ConstAttr>()) {
13592 switch (BuiltinID) {
13593 case Builtin::BI__builtin_fma:
13594 case Builtin::BI__builtin_fmaf:
13595 case Builtin::BI__builtin_fmal:
13596 case Builtin::BIfma:
13597 case Builtin::BIfmaf:
13598 case Builtin::BIfmal:
13599 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13606 if (Context.BuiltinInfo.isReturnsTwice(BuiltinID) &&
13607 !FD->hasAttr<ReturnsTwiceAttr>())
13608 FD->addAttr(ReturnsTwiceAttr::CreateImplicit(Context,
13609 FD->getLocation()));
13610 if (Context.BuiltinInfo.isNoThrow(BuiltinID) && !FD->hasAttr<NoThrowAttr>())
13611 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
13612 if (Context.BuiltinInfo.isPure(BuiltinID) && !FD->hasAttr<PureAttr>())
13613 FD->addAttr(PureAttr::CreateImplicit(Context, FD->getLocation()));
13614 if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr<ConstAttr>())
13615 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13616 if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) &&
13617 !FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) {
13618 // Add the appropriate attribute, depending on the CUDA compilation mode
13619 // and which target the builtin belongs to. For example, during host
13620 // compilation, aux builtins are __device__, while the rest are __host__.
13621 if (getLangOpts().CUDAIsDevice !=
13622 Context.BuiltinInfo.isAuxBuiltinID(BuiltinID))
13623 FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation()));
13625 FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation()));
13629 // If C++ exceptions are enabled but we are told extern "C" functions cannot
13630 // throw, add an implicit nothrow attribute to any extern "C" function we come
13632 if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind &&
13633 FD->isExternC() && !FD->hasAttr<NoThrowAttr>()) {
13634 const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
13635 if (!FPT || FPT->getExceptionSpecType() == EST_None)
13636 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
13639 IdentifierInfo *Name = FD->getIdentifier();
13642 if ((!getLangOpts().CPlusPlus &&
13643 FD->getDeclContext()->isTranslationUnit()) ||
13644 (isa<LinkageSpecDecl>(FD->getDeclContext()) &&
13645 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() ==
13646 LinkageSpecDecl::lang_c)) {
13647 // Okay: this could be a libc/libm/Objective-C function we know
13652 if (Name->isStr("asprintf") || Name->isStr("vasprintf")) {
13653 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be
13654 // target-specific builtins, perhaps?
13655 if (!FD->hasAttr<FormatAttr>())
13656 FD->addAttr(FormatAttr::CreateImplicit(Context,
13657 &Context.Idents.get("printf"), 2,
13658 Name->isStr("vasprintf") ? 0 : 3,
13659 FD->getLocation()));
13662 if (Name->isStr("__CFStringMakeConstantString")) {
13663 // We already have a __builtin___CFStringMakeConstantString,
13664 // but builds that use -fno-constant-cfstrings don't go through that.
13665 if (!FD->hasAttr<FormatArgAttr>())
13666 FD->addAttr(FormatArgAttr::CreateImplicit(Context, ParamIdx(1, FD),
13667 FD->getLocation()));
13671 TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
13672 TypeSourceInfo *TInfo) {
13673 assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
13674 assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
13677 assert(D.isInvalidType() && "no declarator info for valid type");
13678 TInfo = Context.getTrivialTypeSourceInfo(T);
13681 // Scope manipulation handled by caller.
13682 TypedefDecl *NewTD =
13683 TypedefDecl::Create(Context, CurContext, D.getBeginLoc(),
13684 D.getIdentifierLoc(), D.getIdentifier(), TInfo);
13686 // Bail out immediately if we have an invalid declaration.
13687 if (D.isInvalidType()) {
13688 NewTD->setInvalidDecl();
13692 if (D.getDeclSpec().isModulePrivateSpecified()) {
13693 if (CurContext->isFunctionOrMethod())
13694 Diag(NewTD->getLocation(), diag::err_module_private_local)
13695 << 2 << NewTD->getDeclName()
13696 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
13697 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
13699 NewTD->setModulePrivate();
13702 // C++ [dcl.typedef]p8:
13703 // If the typedef declaration defines an unnamed class (or
13704 // enum), the first typedef-name declared by the declaration
13705 // to be that class type (or enum type) is used to denote the
13706 // class type (or enum type) for linkage purposes only.
13707 // We need to check whether the type was declared in the declaration.
13708 switch (D.getDeclSpec().getTypeSpecType()) {
13711 case TST_interface:
13714 TagDecl *tagFromDeclSpec = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
13715 setTagNameForLinkagePurposes(tagFromDeclSpec, NewTD);
13726 /// Check that this is a valid underlying type for an enum declaration.
13727 bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) {
13728 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
13729 QualType T = TI->getType();
13731 if (T->isDependentType())
13734 if (const BuiltinType *BT = T->getAs<BuiltinType>())
13735 if (BT->isInteger())
13738 Diag(UnderlyingLoc, diag::err_enum_invalid_underlying) << T;
13742 /// Check whether this is a valid redeclaration of a previous enumeration.
13743 /// \return true if the redeclaration was invalid.
13744 bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
13745 QualType EnumUnderlyingTy, bool IsFixed,
13746 const EnumDecl *Prev) {
13747 if (IsScoped != Prev->isScoped()) {
13748 Diag(EnumLoc, diag::err_enum_redeclare_scoped_mismatch)
13749 << Prev->isScoped();
13750 Diag(Prev->getLocation(), diag::note_previous_declaration);
13754 if (IsFixed && Prev->isFixed()) {
13755 if (!EnumUnderlyingTy->isDependentType() &&
13756 !Prev->getIntegerType()->isDependentType() &&
13757 !Context.hasSameUnqualifiedType(EnumUnderlyingTy,
13758 Prev->getIntegerType())) {
13759 // TODO: Highlight the underlying type of the redeclaration.
13760 Diag(EnumLoc, diag::err_enum_redeclare_type_mismatch)
13761 << EnumUnderlyingTy << Prev->getIntegerType();
13762 Diag(Prev->getLocation(), diag::note_previous_declaration)
13763 << Prev->getIntegerTypeRange();
13766 } else if (IsFixed != Prev->isFixed()) {
13767 Diag(EnumLoc, diag::err_enum_redeclare_fixed_mismatch)
13768 << Prev->isFixed();
13769 Diag(Prev->getLocation(), diag::note_previous_declaration);
13776 /// Get diagnostic %select index for tag kind for
13777 /// redeclaration diagnostic message.
13778 /// WARNING: Indexes apply to particular diagnostics only!
13780 /// \returns diagnostic %select index.
13781 static unsigned getRedeclDiagFromTagKind(TagTypeKind Tag) {
13783 case TTK_Struct: return 0;
13784 case TTK_Interface: return 1;
13785 case TTK_Class: return 2;
13786 default: llvm_unreachable("Invalid tag kind for redecl diagnostic!");
13790 /// Determine if tag kind is a class-key compatible with
13791 /// class for redeclaration (class, struct, or __interface).
13793 /// \returns true iff the tag kind is compatible.
13794 static bool isClassCompatTagKind(TagTypeKind Tag)
13796 return Tag == TTK_Struct || Tag == TTK_Class || Tag == TTK_Interface;
13799 Sema::NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl,
13801 if (isa<TypedefDecl>(PrevDecl))
13802 return NTK_Typedef;
13803 else if (isa<TypeAliasDecl>(PrevDecl))
13804 return NTK_TypeAlias;
13805 else if (isa<ClassTemplateDecl>(PrevDecl))
13806 return NTK_Template;
13807 else if (isa<TypeAliasTemplateDecl>(PrevDecl))
13808 return NTK_TypeAliasTemplate;
13809 else if (isa<TemplateTemplateParmDecl>(PrevDecl))
13810 return NTK_TemplateTemplateArgument;
13813 case TTK_Interface:
13815 return getLangOpts().CPlusPlus ? NTK_NonClass : NTK_NonStruct;
13817 return NTK_NonUnion;
13819 return NTK_NonEnum;
13821 llvm_unreachable("invalid TTK");
13824 /// Determine whether a tag with a given kind is acceptable
13825 /// as a redeclaration of the given tag declaration.
13827 /// \returns true if the new tag kind is acceptable, false otherwise.
13828 bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
13829 TagTypeKind NewTag, bool isDefinition,
13830 SourceLocation NewTagLoc,
13831 const IdentifierInfo *Name) {
13832 // C++ [dcl.type.elab]p3:
13833 // The class-key or enum keyword present in the
13834 // elaborated-type-specifier shall agree in kind with the
13835 // declaration to which the name in the elaborated-type-specifier
13836 // refers. This rule also applies to the form of
13837 // elaborated-type-specifier that declares a class-name or
13838 // friend class since it can be construed as referring to the
13839 // definition of the class. Thus, in any
13840 // elaborated-type-specifier, the enum keyword shall be used to
13841 // refer to an enumeration (7.2), the union class-key shall be
13842 // used to refer to a union (clause 9), and either the class or
13843 // struct class-key shall be used to refer to a class (clause 9)
13844 // declared using the class or struct class-key.
13845 TagTypeKind OldTag = Previous->getTagKind();
13846 if (OldTag != NewTag &&
13847 !(isClassCompatTagKind(OldTag) && isClassCompatTagKind(NewTag)))
13850 // Tags are compatible, but we might still want to warn on mismatched tags.
13851 // Non-class tags can't be mismatched at this point.
13852 if (!isClassCompatTagKind(NewTag))
13855 // Declarations for which -Wmismatched-tags is disabled are entirely ignored
13856 // by our warning analysis. We don't want to warn about mismatches with (eg)
13857 // declarations in system headers that are designed to be specialized, but if
13858 // a user asks us to warn, we should warn if their code contains mismatched
13860 auto IsIgnoredLoc = [&](SourceLocation Loc) {
13861 return getDiagnostics().isIgnored(diag::warn_struct_class_tag_mismatch,
13864 if (IsIgnoredLoc(NewTagLoc))
13867 auto IsIgnored = [&](const TagDecl *Tag) {
13868 return IsIgnoredLoc(Tag->getLocation());
13870 while (IsIgnored(Previous)) {
13871 Previous = Previous->getPreviousDecl();
13874 OldTag = Previous->getTagKind();
13877 bool isTemplate = false;
13878 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous))
13879 isTemplate = Record->getDescribedClassTemplate();
13881 if (inTemplateInstantiation()) {
13882 if (OldTag != NewTag) {
13883 // In a template instantiation, do not offer fix-its for tag mismatches
13884 // since they usually mess up the template instead of fixing the problem.
13885 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
13886 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13887 << getRedeclDiagFromTagKind(OldTag);
13888 // FIXME: Note previous location?
13893 if (isDefinition) {
13894 // On definitions, check all previous tags and issue a fix-it for each
13895 // one that doesn't match the current tag.
13896 if (Previous->getDefinition()) {
13897 // Don't suggest fix-its for redefinitions.
13901 bool previousMismatch = false;
13902 for (const TagDecl *I : Previous->redecls()) {
13903 if (I->getTagKind() != NewTag) {
13904 // Ignore previous declarations for which the warning was disabled.
13908 if (!previousMismatch) {
13909 previousMismatch = true;
13910 Diag(NewTagLoc, diag::warn_struct_class_previous_tag_mismatch)
13911 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13912 << getRedeclDiagFromTagKind(I->getTagKind());
13914 Diag(I->getInnerLocStart(), diag::note_struct_class_suggestion)
13915 << getRedeclDiagFromTagKind(NewTag)
13916 << FixItHint::CreateReplacement(I->getInnerLocStart(),
13917 TypeWithKeyword::getTagTypeKindName(NewTag));
13923 // Identify the prevailing tag kind: this is the kind of the definition (if
13924 // there is a non-ignored definition), or otherwise the kind of the prior
13925 // (non-ignored) declaration.
13926 const TagDecl *PrevDef = Previous->getDefinition();
13927 if (PrevDef && IsIgnored(PrevDef))
13929 const TagDecl *Redecl = PrevDef ? PrevDef : Previous;
13930 if (Redecl->getTagKind() != NewTag) {
13931 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
13932 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13933 << getRedeclDiagFromTagKind(OldTag);
13934 Diag(Redecl->getLocation(), diag::note_previous_use);
13936 // If there is a previous definition, suggest a fix-it.
13938 Diag(NewTagLoc, diag::note_struct_class_suggestion)
13939 << getRedeclDiagFromTagKind(Redecl->getTagKind())
13940 << FixItHint::CreateReplacement(SourceRange(NewTagLoc),
13941 TypeWithKeyword::getTagTypeKindName(Redecl->getTagKind()));
13948 /// Add a minimal nested name specifier fixit hint to allow lookup of a tag name
13949 /// from an outer enclosing namespace or file scope inside a friend declaration.
13950 /// This should provide the commented out code in the following snippet:
13954 /// struct Y { friend struct /*N::*/ X; };
13957 static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S,
13958 SourceLocation NameLoc) {
13959 // While the decl is in a namespace, do repeated lookup of that name and see
13960 // if we get the same namespace back. If we do not, continue until
13961 // translation unit scope, at which point we have a fully qualified NNS.
13962 SmallVector<IdentifierInfo *, 4> Namespaces;
13963 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
13964 for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
13965 // This tag should be declared in a namespace, which can only be enclosed by
13966 // other namespaces. Bail if there's an anonymous namespace in the chain.
13967 NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(DC);
13968 if (!Namespace || Namespace->isAnonymousNamespace())
13969 return FixItHint();
13970 IdentifierInfo *II = Namespace->getIdentifier();
13971 Namespaces.push_back(II);
13972 NamedDecl *Lookup = SemaRef.LookupSingleName(
13973 S, II, NameLoc, Sema::LookupNestedNameSpecifierName);
13974 if (Lookup == Namespace)
13978 // Once we have all the namespaces, reverse them to go outermost first, and
13980 SmallString<64> Insertion;
13981 llvm::raw_svector_ostream OS(Insertion);
13982 if (DC->isTranslationUnit())
13984 std::reverse(Namespaces.begin(), Namespaces.end());
13985 for (auto *II : Namespaces)
13986 OS << II->getName() << "::";
13987 return FixItHint::CreateInsertion(NameLoc, Insertion);
13990 /// Determine whether a tag originally declared in context \p OldDC can
13991 /// be redeclared with an unqualified name in \p NewDC (assuming name lookup
13992 /// found a declaration in \p OldDC as a previous decl, perhaps through a
13993 /// using-declaration).
13994 static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC,
13995 DeclContext *NewDC) {
13996 OldDC = OldDC->getRedeclContext();
13997 NewDC = NewDC->getRedeclContext();
13999 if (OldDC->Equals(NewDC))
14002 // In MSVC mode, we allow a redeclaration if the contexts are related (either
14003 // encloses the other).
14004 if (S.getLangOpts().MSVCCompat &&
14005 (OldDC->Encloses(NewDC) || NewDC->Encloses(OldDC)))
14011 /// This is invoked when we see 'struct foo' or 'struct {'. In the
14012 /// former case, Name will be non-null. In the later case, Name will be null.
14013 /// TagSpec indicates what kind of tag this is. TUK indicates whether this is a
14014 /// reference/declaration/definition of a tag.
14016 /// \param IsTypeSpecifier \c true if this is a type-specifier (or
14017 /// trailing-type-specifier) other than one in an alias-declaration.
14019 /// \param SkipBody If non-null, will be set to indicate if the caller should
14020 /// skip the definition of this tag and treat it as if it were a declaration.
14021 Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
14022 SourceLocation KWLoc, CXXScopeSpec &SS,
14023 IdentifierInfo *Name, SourceLocation NameLoc,
14024 const ParsedAttributesView &Attrs, AccessSpecifier AS,
14025 SourceLocation ModulePrivateLoc,
14026 MultiTemplateParamsArg TemplateParameterLists,
14027 bool &OwnedDecl, bool &IsDependent,
14028 SourceLocation ScopedEnumKWLoc,
14029 bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
14030 bool IsTypeSpecifier, bool IsTemplateParamOrArg,
14031 SkipBodyInfo *SkipBody) {
14032 // If this is not a definition, it must have a name.
14033 IdentifierInfo *OrigName = Name;
14034 assert((Name != nullptr || TUK == TUK_Definition) &&
14035 "Nameless record must be a definition!");
14036 assert(TemplateParameterLists.size() == 0 || TUK != TUK_Reference);
14039 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
14040 bool ScopedEnum = ScopedEnumKWLoc.isValid();
14042 // FIXME: Check member specializations more carefully.
14043 bool isMemberSpecialization = false;
14044 bool Invalid = false;
14046 // We only need to do this matching if we have template parameters
14047 // or a scope specifier, which also conveniently avoids this work
14048 // for non-C++ cases.
14049 if (TemplateParameterLists.size() > 0 ||
14050 (SS.isNotEmpty() && TUK != TUK_Reference)) {
14051 if (TemplateParameterList *TemplateParams =
14052 MatchTemplateParametersToScopeSpecifier(
14053 KWLoc, NameLoc, SS, nullptr, TemplateParameterLists,
14054 TUK == TUK_Friend, isMemberSpecialization, Invalid)) {
14055 if (Kind == TTK_Enum) {
14056 Diag(KWLoc, diag::err_enum_template);
14060 if (TemplateParams->size() > 0) {
14061 // This is a declaration or definition of a class template (which may
14062 // be a member of another template).
14068 DeclResult Result = CheckClassTemplate(
14069 S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attrs, TemplateParams,
14070 AS, ModulePrivateLoc,
14071 /*FriendLoc*/ SourceLocation(), TemplateParameterLists.size() - 1,
14072 TemplateParameterLists.data(), SkipBody);
14073 return Result.get();
14075 // The "template<>" header is extraneous.
14076 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
14077 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
14078 isMemberSpecialization = true;
14083 // Figure out the underlying type if this a enum declaration. We need to do
14084 // this early, because it's needed to detect if this is an incompatible
14086 llvm::PointerUnion<const Type*, TypeSourceInfo*> EnumUnderlying;
14087 bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum;
14089 if (Kind == TTK_Enum) {
14090 if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) {
14091 // No underlying type explicitly specified, or we failed to parse the
14092 // type, default to int.
14093 EnumUnderlying = Context.IntTy.getTypePtr();
14094 } else if (UnderlyingType.get()) {
14095 // C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an
14096 // integral type; any cv-qualification is ignored.
14097 TypeSourceInfo *TI = nullptr;
14098 GetTypeFromParser(UnderlyingType.get(), &TI);
14099 EnumUnderlying = TI;
14101 if (CheckEnumUnderlyingType(TI))
14102 // Recover by falling back to int.
14103 EnumUnderlying = Context.IntTy.getTypePtr();
14105 if (DiagnoseUnexpandedParameterPack(TI->getTypeLoc().getBeginLoc(), TI,
14106 UPPC_FixedUnderlyingType))
14107 EnumUnderlying = Context.IntTy.getTypePtr();
14109 } else if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
14110 // For MSVC ABI compatibility, unfixed enums must use an underlying type
14111 // of 'int'. However, if this is an unfixed forward declaration, don't set
14112 // the underlying type unless the user enables -fms-compatibility. This
14113 // makes unfixed forward declared enums incomplete and is more conforming.
14114 if (TUK == TUK_Definition || getLangOpts().MSVCCompat)
14115 EnumUnderlying = Context.IntTy.getTypePtr();
14119 DeclContext *SearchDC = CurContext;
14120 DeclContext *DC = CurContext;
14121 bool isStdBadAlloc = false;
14122 bool isStdAlignValT = false;
14124 RedeclarationKind Redecl = forRedeclarationInCurContext();
14125 if (TUK == TUK_Friend || TUK == TUK_Reference)
14126 Redecl = NotForRedeclaration;
14128 /// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C
14129 /// implemented asks for structural equivalence checking, the returned decl
14130 /// here is passed back to the parser, allowing the tag body to be parsed.
14131 auto createTagFromNewDecl = [&]() -> TagDecl * {
14132 assert(!getLangOpts().CPlusPlus && "not meant for C++ usage");
14133 // If there is an identifier, use the location of the identifier as the
14134 // location of the decl, otherwise use the location of the struct/union
14136 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
14137 TagDecl *New = nullptr;
14139 if (Kind == TTK_Enum) {
14140 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, nullptr,
14141 ScopedEnum, ScopedEnumUsesClassTag, IsFixed);
14142 // If this is an undefined enum, bail.
14143 if (TUK != TUK_Definition && !Invalid)
14145 if (EnumUnderlying) {
14146 EnumDecl *ED = cast<EnumDecl>(New);
14147 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo *>())
14148 ED->setIntegerTypeSourceInfo(TI);
14150 ED->setIntegerType(QualType(EnumUnderlying.get<const Type *>(), 0));
14151 ED->setPromotionType(ED->getIntegerType());
14153 } else { // struct/union
14154 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14158 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
14159 // Add alignment attributes if necessary; these attributes are checked
14160 // when the ASTContext lays out the structure.
14162 // It is important for implementing the correct semantics that this
14163 // happen here (in ActOnTag). The #pragma pack stack is
14164 // maintained as a result of parser callbacks which can occur at
14165 // many points during the parsing of a struct declaration (because
14166 // the #pragma tokens are effectively skipped over during the
14167 // parsing of the struct).
14168 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
14169 AddAlignmentAttributesForRecord(RD);
14170 AddMsStructLayoutForRecord(RD);
14173 New->setLexicalDeclContext(CurContext);
14177 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl);
14178 if (Name && SS.isNotEmpty()) {
14179 // We have a nested-name tag ('struct foo::bar').
14181 // Check for invalid 'foo::'.
14182 if (SS.isInvalid()) {
14184 goto CreateNewDecl;
14187 // If this is a friend or a reference to a class in a dependent
14188 // context, don't try to make a decl for it.
14189 if (TUK == TUK_Friend || TUK == TUK_Reference) {
14190 DC = computeDeclContext(SS, false);
14192 IsDependent = true;
14196 DC = computeDeclContext(SS, true);
14198 Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec)
14204 if (RequireCompleteDeclContext(SS, DC))
14208 // Look-up name inside 'foo::'.
14209 LookupQualifiedName(Previous, DC);
14211 if (Previous.isAmbiguous())
14214 if (Previous.empty()) {
14215 // Name lookup did not find anything. However, if the
14216 // nested-name-specifier refers to the current instantiation,
14217 // and that current instantiation has any dependent base
14218 // classes, we might find something at instantiation time: treat
14219 // this as a dependent elaborated-type-specifier.
14220 // But this only makes any sense for reference-like lookups.
14221 if (Previous.wasNotFoundInCurrentInstantiation() &&
14222 (TUK == TUK_Reference || TUK == TUK_Friend)) {
14223 IsDependent = true;
14227 // A tag 'foo::bar' must already exist.
14228 Diag(NameLoc, diag::err_not_tag_in_scope)
14229 << Kind << Name << DC << SS.getRange();
14232 goto CreateNewDecl;
14235 // C++14 [class.mem]p14:
14236 // If T is the name of a class, then each of the following shall have a
14237 // name different from T:
14238 // -- every member of class T that is itself a type
14239 if (TUK != TUK_Reference && TUK != TUK_Friend &&
14240 DiagnoseClassNameShadow(SearchDC, DeclarationNameInfo(Name, NameLoc)))
14243 // If this is a named struct, check to see if there was a previous forward
14244 // declaration or definition.
14245 // FIXME: We're looking into outer scopes here, even when we
14246 // shouldn't be. Doing so can result in ambiguities that we
14247 // shouldn't be diagnosing.
14248 LookupName(Previous, S);
14250 // When declaring or defining a tag, ignore ambiguities introduced
14251 // by types using'ed into this scope.
14252 if (Previous.isAmbiguous() &&
14253 (TUK == TUK_Definition || TUK == TUK_Declaration)) {
14254 LookupResult::Filter F = Previous.makeFilter();
14255 while (F.hasNext()) {
14256 NamedDecl *ND = F.next();
14257 if (!ND->getDeclContext()->getRedeclContext()->Equals(
14258 SearchDC->getRedeclContext()))
14264 // C++11 [namespace.memdef]p3:
14265 // If the name in a friend declaration is neither qualified nor
14266 // a template-id and the declaration is a function or an
14267 // elaborated-type-specifier, the lookup to determine whether
14268 // the entity has been previously declared shall not consider
14269 // any scopes outside the innermost enclosing namespace.
14271 // MSVC doesn't implement the above rule for types, so a friend tag
14272 // declaration may be a redeclaration of a type declared in an enclosing
14273 // scope. They do implement this rule for friend functions.
14275 // Does it matter that this should be by scope instead of by
14276 // semantic context?
14277 if (!Previous.empty() && TUK == TUK_Friend) {
14278 DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext();
14279 LookupResult::Filter F = Previous.makeFilter();
14280 bool FriendSawTagOutsideEnclosingNamespace = false;
14281 while (F.hasNext()) {
14282 NamedDecl *ND = F.next();
14283 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
14284 if (DC->isFileContext() &&
14285 !EnclosingNS->Encloses(ND->getDeclContext())) {
14286 if (getLangOpts().MSVCCompat)
14287 FriendSawTagOutsideEnclosingNamespace = true;
14294 // Diagnose this MSVC extension in the easy case where lookup would have
14295 // unambiguously found something outside the enclosing namespace.
14296 if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) {
14297 NamedDecl *ND = Previous.getFoundDecl();
14298 Diag(NameLoc, diag::ext_friend_tag_redecl_outside_namespace)
14299 << createFriendTagNNSFixIt(*this, ND, S, NameLoc);
14303 // Note: there used to be some attempt at recovery here.
14304 if (Previous.isAmbiguous())
14307 if (!getLangOpts().CPlusPlus && TUK != TUK_Reference) {
14308 // FIXME: This makes sure that we ignore the contexts associated
14309 // with C structs, unions, and enums when looking for a matching
14310 // tag declaration or definition. See the similar lookup tweak
14311 // in Sema::LookupName; is there a better way to deal with this?
14312 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC))
14313 SearchDC = SearchDC->getParent();
14317 if (Previous.isSingleResult() &&
14318 Previous.getFoundDecl()->isTemplateParameter()) {
14319 // Maybe we will complain about the shadowed template parameter.
14320 DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl());
14321 // Just pretend that we didn't see the previous declaration.
14325 if (getLangOpts().CPlusPlus && Name && DC && StdNamespace &&
14326 DC->Equals(getStdNamespace())) {
14327 if (Name->isStr("bad_alloc")) {
14328 // This is a declaration of or a reference to "std::bad_alloc".
14329 isStdBadAlloc = true;
14331 // If std::bad_alloc has been implicitly declared (but made invisible to
14332 // name lookup), fill in this implicit declaration as the previous
14333 // declaration, so that the declarations get chained appropriately.
14334 if (Previous.empty() && StdBadAlloc)
14335 Previous.addDecl(getStdBadAlloc());
14336 } else if (Name->isStr("align_val_t")) {
14337 isStdAlignValT = true;
14338 if (Previous.empty() && StdAlignValT)
14339 Previous.addDecl(getStdAlignValT());
14343 // If we didn't find a previous declaration, and this is a reference
14344 // (or friend reference), move to the correct scope. In C++, we
14345 // also need to do a redeclaration lookup there, just in case
14346 // there's a shadow friend decl.
14347 if (Name && Previous.empty() &&
14348 (TUK == TUK_Reference || TUK == TUK_Friend || IsTemplateParamOrArg)) {
14349 if (Invalid) goto CreateNewDecl;
14350 assert(SS.isEmpty());
14352 if (TUK == TUK_Reference || IsTemplateParamOrArg) {
14353 // C++ [basic.scope.pdecl]p5:
14354 // -- for an elaborated-type-specifier of the form
14356 // class-key identifier
14358 // if the elaborated-type-specifier is used in the
14359 // decl-specifier-seq or parameter-declaration-clause of a
14360 // function defined in namespace scope, the identifier is
14361 // declared as a class-name in the namespace that contains
14362 // the declaration; otherwise, except as a friend
14363 // declaration, the identifier is declared in the smallest
14364 // non-class, non-function-prototype scope that contains the
14367 // C99 6.7.2.3p8 has a similar (but not identical!) provision for
14368 // C structs and unions.
14370 // It is an error in C++ to declare (rather than define) an enum
14371 // type, including via an elaborated type specifier. We'll
14372 // diagnose that later; for now, declare the enum in the same
14373 // scope as we would have picked for any other tag type.
14375 // GNU C also supports this behavior as part of its incomplete
14376 // enum types extension, while GNU C++ does not.
14378 // Find the context where we'll be declaring the tag.
14379 // FIXME: We would like to maintain the current DeclContext as the
14380 // lexical context,
14381 SearchDC = getTagInjectionContext(SearchDC);
14383 // Find the scope where we'll be declaring the tag.
14384 S = getTagInjectionScope(S, getLangOpts());
14386 assert(TUK == TUK_Friend);
14387 // C++ [namespace.memdef]p3:
14388 // If a friend declaration in a non-local class first declares a
14389 // class or function, the friend class or function is a member of
14390 // the innermost enclosing namespace.
14391 SearchDC = SearchDC->getEnclosingNamespaceContext();
14394 // In C++, we need to do a redeclaration lookup to properly
14395 // diagnose some problems.
14396 // FIXME: redeclaration lookup is also used (with and without C++) to find a
14397 // hidden declaration so that we don't get ambiguity errors when using a
14398 // type declared by an elaborated-type-specifier. In C that is not correct
14399 // and we should instead merge compatible types found by lookup.
14400 if (getLangOpts().CPlusPlus) {
14401 Previous.setRedeclarationKind(forRedeclarationInCurContext());
14402 LookupQualifiedName(Previous, SearchDC);
14404 Previous.setRedeclarationKind(forRedeclarationInCurContext());
14405 LookupName(Previous, S);
14409 // If we have a known previous declaration to use, then use it.
14410 if (Previous.empty() && SkipBody && SkipBody->Previous)
14411 Previous.addDecl(SkipBody->Previous);
14413 if (!Previous.empty()) {
14414 NamedDecl *PrevDecl = Previous.getFoundDecl();
14415 NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl();
14417 // It's okay to have a tag decl in the same scope as a typedef
14418 // which hides a tag decl in the same scope. Finding this
14419 // insanity with a redeclaration lookup can only actually happen
14422 // This is also okay for elaborated-type-specifiers, which is
14423 // technically forbidden by the current standard but which is
14424 // okay according to the likely resolution of an open issue;
14425 // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407
14426 if (getLangOpts().CPlusPlus) {
14427 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(PrevDecl)) {
14428 if (const TagType *TT = TD->getUnderlyingType()->getAs<TagType>()) {
14429 TagDecl *Tag = TT->getDecl();
14430 if (Tag->getDeclName() == Name &&
14431 Tag->getDeclContext()->getRedeclContext()
14432 ->Equals(TD->getDeclContext()->getRedeclContext())) {
14435 Previous.addDecl(Tag);
14436 Previous.resolveKind();
14442 // If this is a redeclaration of a using shadow declaration, it must
14443 // declare a tag in the same context. In MSVC mode, we allow a
14444 // redefinition if either context is within the other.
14445 if (auto *Shadow = dyn_cast<UsingShadowDecl>(DirectPrevDecl)) {
14446 auto *OldTag = dyn_cast<TagDecl>(PrevDecl);
14447 if (SS.isEmpty() && TUK != TUK_Reference && TUK != TUK_Friend &&
14448 isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) &&
14449 !(OldTag && isAcceptableTagRedeclContext(
14450 *this, OldTag->getDeclContext(), SearchDC))) {
14451 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
14452 Diag(Shadow->getTargetDecl()->getLocation(),
14453 diag::note_using_decl_target);
14454 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl)
14456 // Recover by ignoring the old declaration.
14458 goto CreateNewDecl;
14462 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
14463 // If this is a use of a previous tag, or if the tag is already declared
14464 // in the same scope (so that the definition/declaration completes or
14465 // rementions the tag), reuse the decl.
14466 if (TUK == TUK_Reference || TUK == TUK_Friend ||
14467 isDeclInScope(DirectPrevDecl, SearchDC, S,
14468 SS.isNotEmpty() || isMemberSpecialization)) {
14469 // Make sure that this wasn't declared as an enum and now used as a
14470 // struct or something similar.
14471 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind,
14472 TUK == TUK_Definition, KWLoc,
14474 bool SafeToContinue
14475 = (PrevTagDecl->getTagKind() != TTK_Enum &&
14477 if (SafeToContinue)
14478 Diag(KWLoc, diag::err_use_with_wrong_tag)
14480 << FixItHint::CreateReplacement(SourceRange(KWLoc),
14481 PrevTagDecl->getKindName());
14483 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
14484 Diag(PrevTagDecl->getLocation(), diag::note_previous_use);
14486 if (SafeToContinue)
14487 Kind = PrevTagDecl->getTagKind();
14489 // Recover by making this an anonymous redefinition.
14496 if (Kind == TTK_Enum && PrevTagDecl->getTagKind() == TTK_Enum) {
14497 const EnumDecl *PrevEnum = cast<EnumDecl>(PrevTagDecl);
14499 // If this is an elaborated-type-specifier for a scoped enumeration,
14500 // the 'class' keyword is not necessary and not permitted.
14501 if (TUK == TUK_Reference || TUK == TUK_Friend) {
14503 Diag(ScopedEnumKWLoc, diag::err_enum_class_reference)
14504 << PrevEnum->isScoped()
14505 << FixItHint::CreateRemoval(ScopedEnumKWLoc);
14506 return PrevTagDecl;
14509 QualType EnumUnderlyingTy;
14510 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
14511 EnumUnderlyingTy = TI->getType().getUnqualifiedType();
14512 else if (const Type *T = EnumUnderlying.dyn_cast<const Type*>())
14513 EnumUnderlyingTy = QualType(T, 0);
14515 // All conflicts with previous declarations are recovered by
14516 // returning the previous declaration, unless this is a definition,
14517 // in which case we want the caller to bail out.
14518 if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc,
14519 ScopedEnum, EnumUnderlyingTy,
14520 IsFixed, PrevEnum))
14521 return TUK == TUK_Declaration ? PrevTagDecl : nullptr;
14524 // C++11 [class.mem]p1:
14525 // A member shall not be declared twice in the member-specification,
14526 // except that a nested class or member class template can be declared
14527 // and then later defined.
14528 if (TUK == TUK_Declaration && PrevDecl->isCXXClassMember() &&
14529 S->isDeclScope(PrevDecl)) {
14530 Diag(NameLoc, diag::ext_member_redeclared);
14531 Diag(PrevTagDecl->getLocation(), diag::note_previous_declaration);
14535 // If this is a use, just return the declaration we found, unless
14536 // we have attributes.
14537 if (TUK == TUK_Reference || TUK == TUK_Friend) {
14538 if (!Attrs.empty()) {
14539 // FIXME: Diagnose these attributes. For now, we create a new
14540 // declaration to hold them.
14541 } else if (TUK == TUK_Reference &&
14542 (PrevTagDecl->getFriendObjectKind() ==
14543 Decl::FOK_Undeclared ||
14544 PrevDecl->getOwningModule() != getCurrentModule()) &&
14546 // This declaration is a reference to an existing entity, but
14547 // has different visibility from that entity: it either makes
14548 // a friend visible or it makes a type visible in a new module.
14549 // In either case, create a new declaration. We only do this if
14550 // the declaration would have meant the same thing if no prior
14551 // declaration were found, that is, if it was found in the same
14552 // scope where we would have injected a declaration.
14553 if (!getTagInjectionContext(CurContext)->getRedeclContext()
14554 ->Equals(PrevDecl->getDeclContext()->getRedeclContext()))
14555 return PrevTagDecl;
14556 // This is in the injected scope, create a new declaration in
14558 S = getTagInjectionScope(S, getLangOpts());
14560 return PrevTagDecl;
14564 // Diagnose attempts to redefine a tag.
14565 if (TUK == TUK_Definition) {
14566 if (NamedDecl *Def = PrevTagDecl->getDefinition()) {
14567 // If we're defining a specialization and the previous definition
14568 // is from an implicit instantiation, don't emit an error
14569 // here; we'll catch this in the general case below.
14570 bool IsExplicitSpecializationAfterInstantiation = false;
14571 if (isMemberSpecialization) {
14572 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Def))
14573 IsExplicitSpecializationAfterInstantiation =
14574 RD->getTemplateSpecializationKind() !=
14575 TSK_ExplicitSpecialization;
14576 else if (EnumDecl *ED = dyn_cast<EnumDecl>(Def))
14577 IsExplicitSpecializationAfterInstantiation =
14578 ED->getTemplateSpecializationKind() !=
14579 TSK_ExplicitSpecialization;
14582 // Note that clang allows ODR-like semantics for ObjC/C, i.e., do
14583 // not keep more that one definition around (merge them). However,
14584 // ensure the decl passes the structural compatibility check in
14585 // C11 6.2.7/1 (or 6.1.2.6/1 in C89).
14586 NamedDecl *Hidden = nullptr;
14587 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
14588 // There is a definition of this tag, but it is not visible. We
14589 // explicitly make use of C++'s one definition rule here, and
14590 // assume that this definition is identical to the hidden one
14591 // we already have. Make the existing definition visible and
14592 // use it in place of this one.
14593 if (!getLangOpts().CPlusPlus) {
14594 // Postpone making the old definition visible until after we
14595 // complete parsing the new one and do the structural
14597 SkipBody->CheckSameAsPrevious = true;
14598 SkipBody->New = createTagFromNewDecl();
14599 SkipBody->Previous = Def;
14602 SkipBody->ShouldSkip = true;
14603 SkipBody->Previous = Def;
14604 makeMergedDefinitionVisible(Hidden);
14605 // Carry on and handle it like a normal definition. We'll
14606 // skip starting the definitiion later.
14608 } else if (!IsExplicitSpecializationAfterInstantiation) {
14609 // A redeclaration in function prototype scope in C isn't
14610 // visible elsewhere, so merely issue a warning.
14611 if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope())
14612 Diag(NameLoc, diag::warn_redefinition_in_param_list) << Name;
14614 Diag(NameLoc, diag::err_redefinition) << Name;
14615 notePreviousDefinition(Def,
14616 NameLoc.isValid() ? NameLoc : KWLoc);
14617 // If this is a redefinition, recover by making this
14618 // struct be anonymous, which will make any later
14619 // references get the previous definition.
14625 // If the type is currently being defined, complain
14626 // about a nested redefinition.
14627 auto *TD = Context.getTagDeclType(PrevTagDecl)->getAsTagDecl();
14628 if (TD->isBeingDefined()) {
14629 Diag(NameLoc, diag::err_nested_redefinition) << Name;
14630 Diag(PrevTagDecl->getLocation(),
14631 diag::note_previous_definition);
14638 // Okay, this is definition of a previously declared or referenced
14639 // tag. We're going to create a new Decl for it.
14642 // Okay, we're going to make a redeclaration. If this is some kind
14643 // of reference, make sure we build the redeclaration in the same DC
14644 // as the original, and ignore the current access specifier.
14645 if (TUK == TUK_Friend || TUK == TUK_Reference) {
14646 SearchDC = PrevTagDecl->getDeclContext();
14650 // If we get here we have (another) forward declaration or we
14651 // have a definition. Just create a new decl.
14654 // If we get here, this is a definition of a new tag type in a nested
14655 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
14656 // new decl/type. We set PrevDecl to NULL so that the entities
14657 // have distinct types.
14660 // If we get here, we're going to create a new Decl. If PrevDecl
14661 // is non-NULL, it's a definition of the tag declared by
14662 // PrevDecl. If it's NULL, we have a new definition.
14664 // Otherwise, PrevDecl is not a tag, but was found with tag
14665 // lookup. This is only actually possible in C++, where a few
14666 // things like templates still live in the tag namespace.
14668 // Use a better diagnostic if an elaborated-type-specifier
14669 // found the wrong kind of type on the first
14670 // (non-redeclaration) lookup.
14671 if ((TUK == TUK_Reference || TUK == TUK_Friend) &&
14672 !Previous.isForRedeclaration()) {
14673 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
14674 Diag(NameLoc, diag::err_tag_reference_non_tag) << PrevDecl << NTK
14676 Diag(PrevDecl->getLocation(), diag::note_declared_at);
14679 // Otherwise, only diagnose if the declaration is in scope.
14680 } else if (!isDeclInScope(DirectPrevDecl, SearchDC, S,
14681 SS.isNotEmpty() || isMemberSpecialization)) {
14684 // Diagnose implicit declarations introduced by elaborated types.
14685 } else if (TUK == TUK_Reference || TUK == TUK_Friend) {
14686 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
14687 Diag(NameLoc, diag::err_tag_reference_conflict) << NTK;
14688 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
14691 // Otherwise it's a declaration. Call out a particularly common
14693 } else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(PrevDecl)) {
14695 if (isa<TypeAliasDecl>(PrevDecl)) Kind = 1;
14696 Diag(NameLoc, diag::err_tag_definition_of_typedef)
14697 << Name << Kind << TND->getUnderlyingType();
14698 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
14701 // Otherwise, diagnose.
14703 // The tag name clashes with something else in the target scope,
14704 // issue an error and recover by making this tag be anonymous.
14705 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
14706 notePreviousDefinition(PrevDecl, NameLoc);
14711 // The existing declaration isn't relevant to us; we're in a
14712 // new scope, so clear out the previous declaration.
14719 TagDecl *PrevDecl = nullptr;
14720 if (Previous.isSingleResult())
14721 PrevDecl = cast<TagDecl>(Previous.getFoundDecl());
14723 // If there is an identifier, use the location of the identifier as the
14724 // location of the decl, otherwise use the location of the struct/union
14726 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
14728 // Otherwise, create a new declaration. If there is a previous
14729 // declaration of the same entity, the two will be linked via
14733 if (Kind == TTK_Enum) {
14734 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
14735 // enum X { A, B, C } D; D should chain to X.
14736 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name,
14737 cast_or_null<EnumDecl>(PrevDecl), ScopedEnum,
14738 ScopedEnumUsesClassTag, IsFixed);
14740 if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit()))
14741 StdAlignValT = cast<EnumDecl>(New);
14743 // If this is an undefined enum, warn.
14744 if (TUK != TUK_Definition && !Invalid) {
14746 if (IsFixed && (getLangOpts().CPlusPlus11 || getLangOpts().ObjC) &&
14747 cast<EnumDecl>(New)->isFixed()) {
14748 // C++0x: 7.2p2: opaque-enum-declaration.
14749 // Conflicts are diagnosed above. Do nothing.
14751 else if (PrevDecl && (Def = cast<EnumDecl>(PrevDecl)->getDefinition())) {
14752 Diag(Loc, diag::ext_forward_ref_enum_def)
14754 Diag(Def->getLocation(), diag::note_previous_definition);
14756 unsigned DiagID = diag::ext_forward_ref_enum;
14757 if (getLangOpts().MSVCCompat)
14758 DiagID = diag::ext_ms_forward_ref_enum;
14759 else if (getLangOpts().CPlusPlus)
14760 DiagID = diag::err_forward_ref_enum;
14765 if (EnumUnderlying) {
14766 EnumDecl *ED = cast<EnumDecl>(New);
14767 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
14768 ED->setIntegerTypeSourceInfo(TI);
14770 ED->setIntegerType(QualType(EnumUnderlying.get<const Type*>(), 0));
14771 ED->setPromotionType(ED->getIntegerType());
14772 assert(ED->isComplete() && "enum with type should be complete");
14775 // struct/union/class
14777 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
14778 // struct X { int A; } D; D should chain to X.
14779 if (getLangOpts().CPlusPlus) {
14780 // FIXME: Look for a way to use RecordDecl for simple structs.
14781 New = CXXRecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14782 cast_or_null<CXXRecordDecl>(PrevDecl));
14784 if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit()))
14785 StdBadAlloc = cast<CXXRecordDecl>(New);
14787 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14788 cast_or_null<RecordDecl>(PrevDecl));
14791 // C++11 [dcl.type]p3:
14792 // A type-specifier-seq shall not define a class or enumeration [...].
14793 if (getLangOpts().CPlusPlus && (IsTypeSpecifier || IsTemplateParamOrArg) &&
14794 TUK == TUK_Definition) {
14795 Diag(New->getLocation(), diag::err_type_defined_in_type_specifier)
14796 << Context.getTagDeclType(New);
14800 if (!Invalid && getLangOpts().CPlusPlus && TUK == TUK_Definition &&
14801 DC->getDeclKind() == Decl::Enum) {
14802 Diag(New->getLocation(), diag::err_type_defined_in_enum)
14803 << Context.getTagDeclType(New);
14807 // Maybe add qualifier info.
14808 if (SS.isNotEmpty()) {
14810 // If this is either a declaration or a definition, check the
14811 // nested-name-specifier against the current context.
14812 if ((TUK == TUK_Definition || TUK == TUK_Declaration) &&
14813 diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc,
14814 isMemberSpecialization))
14817 New->setQualifierInfo(SS.getWithLocInContext(Context));
14818 if (TemplateParameterLists.size() > 0) {
14819 New->setTemplateParameterListsInfo(Context, TemplateParameterLists);
14826 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
14827 // Add alignment attributes if necessary; these attributes are checked when
14828 // the ASTContext lays out the structure.
14830 // It is important for implementing the correct semantics that this
14831 // happen here (in ActOnTag). The #pragma pack stack is
14832 // maintained as a result of parser callbacks which can occur at
14833 // many points during the parsing of a struct declaration (because
14834 // the #pragma tokens are effectively skipped over during the
14835 // parsing of the struct).
14836 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
14837 AddAlignmentAttributesForRecord(RD);
14838 AddMsStructLayoutForRecord(RD);
14842 if (ModulePrivateLoc.isValid()) {
14843 if (isMemberSpecialization)
14844 Diag(New->getLocation(), diag::err_module_private_specialization)
14846 << FixItHint::CreateRemoval(ModulePrivateLoc);
14847 // __module_private__ does not apply to local classes. However, we only
14848 // diagnose this as an error when the declaration specifiers are
14849 // freestanding. Here, we just ignore the __module_private__.
14850 else if (!SearchDC->isFunctionOrMethod())
14851 New->setModulePrivate();
14854 // If this is a specialization of a member class (of a class template),
14855 // check the specialization.
14856 if (isMemberSpecialization && CheckMemberSpecialization(New, Previous))
14859 // If we're declaring or defining a tag in function prototype scope in C,
14860 // note that this type can only be used within the function and add it to
14861 // the list of decls to inject into the function definition scope.
14862 if ((Name || Kind == TTK_Enum) &&
14863 getNonFieldDeclScope(S)->isFunctionPrototypeScope()) {
14864 if (getLangOpts().CPlusPlus) {
14865 // C++ [dcl.fct]p6:
14866 // Types shall not be defined in return or parameter types.
14867 if (TUK == TUK_Definition && !IsTypeSpecifier) {
14868 Diag(Loc, diag::err_type_defined_in_param_type)
14872 } else if (!PrevDecl) {
14873 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New);
14878 New->setInvalidDecl();
14880 // Set the lexical context. If the tag has a C++ scope specifier, the
14881 // lexical context will be different from the semantic context.
14882 New->setLexicalDeclContext(CurContext);
14884 // Mark this as a friend decl if applicable.
14885 // In Microsoft mode, a friend declaration also acts as a forward
14886 // declaration so we always pass true to setObjectOfFriendDecl to make
14887 // the tag name visible.
14888 if (TUK == TUK_Friend)
14889 New->setObjectOfFriendDecl(getLangOpts().MSVCCompat);
14891 // Set the access specifier.
14892 if (!Invalid && SearchDC->isRecord())
14893 SetMemberAccessSpecifier(New, PrevDecl, AS);
14896 CheckRedeclarationModuleOwnership(New, PrevDecl);
14898 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip))
14899 New->startDefinition();
14901 ProcessDeclAttributeList(S, New, Attrs);
14902 AddPragmaAttributes(S, New);
14904 // If this has an identifier, add it to the scope stack.
14905 if (TUK == TUK_Friend) {
14906 // We might be replacing an existing declaration in the lookup tables;
14907 // if so, borrow its access specifier.
14909 New->setAccess(PrevDecl->getAccess());
14911 DeclContext *DC = New->getDeclContext()->getRedeclContext();
14912 DC->makeDeclVisibleInContext(New);
14913 if (Name) // can be null along some error paths
14914 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
14915 PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false);
14917 S = getNonFieldDeclScope(S);
14918 PushOnScopeChains(New, S, true);
14920 CurContext->addDecl(New);
14923 // If this is the C FILE type, notify the AST context.
14924 if (IdentifierInfo *II = New->getIdentifier())
14925 if (!New->isInvalidDecl() &&
14926 New->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
14928 Context.setFILEDecl(New);
14931 mergeDeclAttributes(New, PrevDecl);
14933 // If there's a #pragma GCC visibility in scope, set the visibility of this
14935 AddPushedVisibilityAttribute(New);
14937 if (isMemberSpecialization && !New->isInvalidDecl())
14938 CompleteMemberSpecialization(New, Previous);
14941 // In C++, don't return an invalid declaration. We can't recover well from
14942 // the cases where we make the type anonymous.
14943 if (Invalid && getLangOpts().CPlusPlus) {
14944 if (New->isBeingDefined())
14945 if (auto RD = dyn_cast<RecordDecl>(New))
14946 RD->completeDefinition();
14948 } else if (SkipBody && SkipBody->ShouldSkip) {
14949 return SkipBody->Previous;
14955 void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) {
14956 AdjustDeclIfTemplate(TagD);
14957 TagDecl *Tag = cast<TagDecl>(TagD);
14959 // Enter the tag context.
14960 PushDeclContext(S, Tag);
14962 ActOnDocumentableDecl(TagD);
14964 // If there's a #pragma GCC visibility in scope, set the visibility of this
14966 AddPushedVisibilityAttribute(Tag);
14969 bool Sema::ActOnDuplicateDefinition(DeclSpec &DS, Decl *Prev,
14970 SkipBodyInfo &SkipBody) {
14971 if (!hasStructuralCompatLayout(Prev, SkipBody.New))
14974 // Make the previous decl visible.
14975 makeMergedDefinitionVisible(SkipBody.Previous);
14979 Decl *Sema::ActOnObjCContainerStartDefinition(Decl *IDecl) {
14980 assert(isa<ObjCContainerDecl>(IDecl) &&
14981 "ActOnObjCContainerStartDefinition - Not ObjCContainerDecl");
14982 DeclContext *OCD = cast<DeclContext>(IDecl);
14983 assert(getContainingDC(OCD) == CurContext &&
14984 "The next DeclContext should be lexically contained in the current one.");
14989 void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD,
14990 SourceLocation FinalLoc,
14991 bool IsFinalSpelledSealed,
14992 SourceLocation LBraceLoc) {
14993 AdjustDeclIfTemplate(TagD);
14994 CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD);
14996 FieldCollector->StartClass();
14998 if (!Record->getIdentifier())
15001 if (FinalLoc.isValid())
15002 Record->addAttr(new (Context)
15003 FinalAttr(FinalLoc, Context, IsFinalSpelledSealed));
15006 // [...] The class-name is also inserted into the scope of the
15007 // class itself; this is known as the injected-class-name. For
15008 // purposes of access checking, the injected-class-name is treated
15009 // as if it were a public member name.
15010 CXXRecordDecl *InjectedClassName = CXXRecordDecl::Create(
15011 Context, Record->getTagKind(), CurContext, Record->getBeginLoc(),
15012 Record->getLocation(), Record->getIdentifier(),
15013 /*PrevDecl=*/nullptr,
15014 /*DelayTypeCreation=*/true);
15015 Context.getTypeDeclType(InjectedClassName, Record);
15016 InjectedClassName->setImplicit();
15017 InjectedClassName->setAccess(AS_public);
15018 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate())
15019 InjectedClassName->setDescribedClassTemplate(Template);
15020 PushOnScopeChains(InjectedClassName, S);
15021 assert(InjectedClassName->isInjectedClassName() &&
15022 "Broken injected-class-name");
15025 void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
15026 SourceRange BraceRange) {
15027 AdjustDeclIfTemplate(TagD);
15028 TagDecl *Tag = cast<TagDecl>(TagD);
15029 Tag->setBraceRange(BraceRange);
15031 // Make sure we "complete" the definition even it is invalid.
15032 if (Tag->isBeingDefined()) {
15033 assert(Tag->isInvalidDecl() && "We should already have completed it");
15034 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
15035 RD->completeDefinition();
15038 if (isa<CXXRecordDecl>(Tag)) {
15039 FieldCollector->FinishClass();
15042 // Exit this scope of this tag's definition.
15045 if (getCurLexicalContext()->isObjCContainer() &&
15046 Tag->getDeclContext()->isFileContext())
15047 Tag->setTopLevelDeclInObjCContainer();
15049 // Notify the consumer that we've defined a tag.
15050 if (!Tag->isInvalidDecl())
15051 Consumer.HandleTagDeclDefinition(Tag);
15054 void Sema::ActOnObjCContainerFinishDefinition() {
15055 // Exit this scope of this interface definition.
15059 void Sema::ActOnObjCTemporaryExitContainerContext(DeclContext *DC) {
15060 assert(DC == CurContext && "Mismatch of container contexts");
15061 OriginalLexicalContext = DC;
15062 ActOnObjCContainerFinishDefinition();
15065 void Sema::ActOnObjCReenterContainerContext(DeclContext *DC) {
15066 ActOnObjCContainerStartDefinition(cast<Decl>(DC));
15067 OriginalLexicalContext = nullptr;
15070 void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) {
15071 AdjustDeclIfTemplate(TagD);
15072 TagDecl *Tag = cast<TagDecl>(TagD);
15073 Tag->setInvalidDecl();
15075 // Make sure we "complete" the definition even it is invalid.
15076 if (Tag->isBeingDefined()) {
15077 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
15078 RD->completeDefinition();
15081 // We're undoing ActOnTagStartDefinition here, not
15082 // ActOnStartCXXMemberDeclarations, so we don't have to mess with
15083 // the FieldCollector.
15088 // Note that FieldName may be null for anonymous bitfields.
15089 ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
15090 IdentifierInfo *FieldName,
15091 QualType FieldTy, bool IsMsStruct,
15092 Expr *BitWidth, bool *ZeroWidth) {
15093 // Default to true; that shouldn't confuse checks for emptiness
15097 // C99 6.7.2.1p4 - verify the field type.
15098 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
15099 if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) {
15100 // Handle incomplete types with specific error.
15101 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete))
15102 return ExprError();
15104 return Diag(FieldLoc, diag::err_not_integral_type_bitfield)
15105 << FieldName << FieldTy << BitWidth->getSourceRange();
15106 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield)
15107 << FieldTy << BitWidth->getSourceRange();
15108 } else if (DiagnoseUnexpandedParameterPack(const_cast<Expr *>(BitWidth),
15109 UPPC_BitFieldWidth))
15110 return ExprError();
15112 // If the bit-width is type- or value-dependent, don't try to check
15114 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent())
15117 llvm::APSInt Value;
15118 ExprResult ICE = VerifyIntegerConstantExpression(BitWidth, &Value);
15119 if (ICE.isInvalid())
15121 BitWidth = ICE.get();
15123 if (Value != 0 && ZeroWidth)
15124 *ZeroWidth = false;
15126 // Zero-width bitfield is ok for anonymous field.
15127 if (Value == 0 && FieldName)
15128 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName;
15130 if (Value.isSigned() && Value.isNegative()) {
15132 return Diag(FieldLoc, diag::err_bitfield_has_negative_width)
15133 << FieldName << Value.toString(10);
15134 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width)
15135 << Value.toString(10);
15138 if (!FieldTy->isDependentType()) {
15139 uint64_t TypeStorageSize = Context.getTypeSize(FieldTy);
15140 uint64_t TypeWidth = Context.getIntWidth(FieldTy);
15141 bool BitfieldIsOverwide = Value.ugt(TypeWidth);
15143 // Over-wide bitfields are an error in C or when using the MSVC bitfield
15145 bool CStdConstraintViolation =
15146 BitfieldIsOverwide && !getLangOpts().CPlusPlus;
15147 bool MSBitfieldViolation =
15148 Value.ugt(TypeStorageSize) &&
15149 (IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft());
15150 if (CStdConstraintViolation || MSBitfieldViolation) {
15151 unsigned DiagWidth =
15152 CStdConstraintViolation ? TypeWidth : TypeStorageSize;
15154 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width)
15155 << FieldName << (unsigned)Value.getZExtValue()
15156 << !CStdConstraintViolation << DiagWidth;
15158 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_width)
15159 << (unsigned)Value.getZExtValue() << !CStdConstraintViolation
15163 // Warn on types where the user might conceivably expect to get all
15164 // specified bits as value bits: that's all integral types other than
15166 if (BitfieldIsOverwide && !FieldTy->isBooleanType()) {
15168 Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width)
15169 << FieldName << (unsigned)Value.getZExtValue()
15170 << (unsigned)TypeWidth;
15172 Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_width)
15173 << (unsigned)Value.getZExtValue() << (unsigned)TypeWidth;
15180 /// ActOnField - Each field of a C struct/union is passed into this in order
15181 /// to create a FieldDecl object for it.
15182 Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
15183 Declarator &D, Expr *BitfieldWidth) {
15184 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD),
15185 DeclStart, D, static_cast<Expr*>(BitfieldWidth),
15186 /*InitStyle=*/ICIS_NoInit, AS_public);
15190 /// HandleField - Analyze a field of a C struct or a C++ data member.
15192 FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
15193 SourceLocation DeclStart,
15194 Declarator &D, Expr *BitWidth,
15195 InClassInitStyle InitStyle,
15196 AccessSpecifier AS) {
15197 if (D.isDecompositionDeclarator()) {
15198 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
15199 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
15200 << Decomp.getSourceRange();
15204 IdentifierInfo *II = D.getIdentifier();
15205 SourceLocation Loc = DeclStart;
15206 if (II) Loc = D.getIdentifierLoc();
15208 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15209 QualType T = TInfo->getType();
15210 if (getLangOpts().CPlusPlus) {
15211 CheckExtraCXXDefaultArguments(D);
15213 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
15214 UPPC_DataMemberType)) {
15215 D.setInvalidType();
15217 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
15221 DiagnoseFunctionSpecifiers(D.getDeclSpec());
15223 if (D.getDeclSpec().isInlineSpecified())
15224 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
15225 << getLangOpts().CPlusPlus17;
15226 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
15227 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
15228 diag::err_invalid_thread)
15229 << DeclSpec::getSpecifierName(TSCS);
15231 // Check to see if this name was declared as a member previously
15232 NamedDecl *PrevDecl = nullptr;
15233 LookupResult Previous(*this, II, Loc, LookupMemberName,
15234 ForVisibleRedeclaration);
15235 LookupName(Previous, S);
15236 switch (Previous.getResultKind()) {
15237 case LookupResult::Found:
15238 case LookupResult::FoundUnresolvedValue:
15239 PrevDecl = Previous.getAsSingle<NamedDecl>();
15242 case LookupResult::FoundOverloaded:
15243 PrevDecl = Previous.getRepresentativeDecl();
15246 case LookupResult::NotFound:
15247 case LookupResult::NotFoundInCurrentInstantiation:
15248 case LookupResult::Ambiguous:
15251 Previous.suppressDiagnostics();
15253 if (PrevDecl && PrevDecl->isTemplateParameter()) {
15254 // Maybe we will complain about the shadowed template parameter.
15255 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
15256 // Just pretend that we didn't see the previous declaration.
15257 PrevDecl = nullptr;
15260 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
15261 PrevDecl = nullptr;
15264 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable);
15265 SourceLocation TSSL = D.getBeginLoc();
15267 = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, InitStyle,
15268 TSSL, AS, PrevDecl, &D);
15270 if (NewFD->isInvalidDecl())
15271 Record->setInvalidDecl();
15273 if (D.getDeclSpec().isModulePrivateSpecified())
15274 NewFD->setModulePrivate();
15276 if (NewFD->isInvalidDecl() && PrevDecl) {
15277 // Don't introduce NewFD into scope; there's already something
15278 // with the same name in the same scope.
15280 PushOnScopeChains(NewFD, S);
15282 Record->addDecl(NewFD);
15287 /// Build a new FieldDecl and check its well-formedness.
15289 /// This routine builds a new FieldDecl given the fields name, type,
15290 /// record, etc. \p PrevDecl should refer to any previous declaration
15291 /// with the same name and in the same scope as the field to be
15294 /// \returns a new FieldDecl.
15296 /// \todo The Declarator argument is a hack. It will be removed once
15297 FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
15298 TypeSourceInfo *TInfo,
15299 RecordDecl *Record, SourceLocation Loc,
15300 bool Mutable, Expr *BitWidth,
15301 InClassInitStyle InitStyle,
15302 SourceLocation TSSL,
15303 AccessSpecifier AS, NamedDecl *PrevDecl,
15305 IdentifierInfo *II = Name.getAsIdentifierInfo();
15306 bool InvalidDecl = false;
15307 if (D) InvalidDecl = D->isInvalidType();
15309 // If we receive a broken type, recover by assuming 'int' and
15310 // marking this declaration as invalid.
15312 InvalidDecl = true;
15316 QualType EltTy = Context.getBaseElementType(T);
15317 if (!EltTy->isDependentType()) {
15318 if (RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) {
15319 // Fields of incomplete type force their record to be invalid.
15320 Record->setInvalidDecl();
15321 InvalidDecl = true;
15324 EltTy->isIncompleteType(&Def);
15325 if (Def && Def->isInvalidDecl()) {
15326 Record->setInvalidDecl();
15327 InvalidDecl = true;
15332 // TR 18037 does not allow fields to be declared with address space
15333 if (T.getQualifiers().hasAddressSpace() || T->isDependentAddressSpaceType() ||
15334 T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) {
15335 Diag(Loc, diag::err_field_with_address_space);
15336 Record->setInvalidDecl();
15337 InvalidDecl = true;
15340 if (LangOpts.OpenCL) {
15341 // OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be
15342 // used as structure or union field: image, sampler, event or block types.
15343 if (T->isEventT() || T->isImageType() || T->isSamplerT() ||
15344 T->isBlockPointerType()) {
15345 Diag(Loc, diag::err_opencl_type_struct_or_union_field) << T;
15346 Record->setInvalidDecl();
15347 InvalidDecl = true;
15349 // OpenCL v1.2 s6.9.c: bitfields are not supported.
15351 Diag(Loc, diag::err_opencl_bitfields);
15352 InvalidDecl = true;
15356 // Anonymous bit-fields cannot be cv-qualified (CWG 2229).
15357 if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth &&
15358 T.hasQualifiers()) {
15359 InvalidDecl = true;
15360 Diag(Loc, diag::err_anon_bitfield_qualifiers);
15363 // C99 6.7.2.1p8: A member of a structure or union may have any type other
15364 // than a variably modified type.
15365 if (!InvalidDecl && T->isVariablyModifiedType()) {
15366 bool SizeIsNegative;
15367 llvm::APSInt Oversized;
15369 TypeSourceInfo *FixedTInfo =
15370 TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
15374 Diag(Loc, diag::warn_illegal_constant_array_size);
15375 TInfo = FixedTInfo;
15376 T = FixedTInfo->getType();
15378 if (SizeIsNegative)
15379 Diag(Loc, diag::err_typecheck_negative_array_size);
15380 else if (Oversized.getBoolValue())
15381 Diag(Loc, diag::err_array_too_large)
15382 << Oversized.toString(10);
15384 Diag(Loc, diag::err_typecheck_field_variable_size);
15385 InvalidDecl = true;
15389 // Fields can not have abstract class types
15390 if (!InvalidDecl && RequireNonAbstractType(Loc, T,
15391 diag::err_abstract_type_in_decl,
15392 AbstractFieldType))
15393 InvalidDecl = true;
15395 bool ZeroWidth = false;
15397 BitWidth = nullptr;
15398 // If this is declared as a bit-field, check the bit-field.
15400 BitWidth = VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth,
15403 InvalidDecl = true;
15404 BitWidth = nullptr;
15409 // Check that 'mutable' is consistent with the type of the declaration.
15410 if (!InvalidDecl && Mutable) {
15411 unsigned DiagID = 0;
15412 if (T->isReferenceType())
15413 DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference
15414 : diag::err_mutable_reference;
15415 else if (T.isConstQualified())
15416 DiagID = diag::err_mutable_const;
15419 SourceLocation ErrLoc = Loc;
15420 if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid())
15421 ErrLoc = D->getDeclSpec().getStorageClassSpecLoc();
15422 Diag(ErrLoc, DiagID);
15423 if (DiagID != diag::ext_mutable_reference) {
15425 InvalidDecl = true;
15430 // C++11 [class.union]p8 (DR1460):
15431 // At most one variant member of a union may have a
15432 // brace-or-equal-initializer.
15433 if (InitStyle != ICIS_NoInit)
15434 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Record), Loc);
15436 FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo,
15437 BitWidth, Mutable, InitStyle);
15439 NewFD->setInvalidDecl();
15441 if (PrevDecl && !isa<TagDecl>(PrevDecl)) {
15442 Diag(Loc, diag::err_duplicate_member) << II;
15443 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
15444 NewFD->setInvalidDecl();
15447 if (!InvalidDecl && getLangOpts().CPlusPlus) {
15448 if (Record->isUnion()) {
15449 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
15450 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl());
15451 if (RDecl->getDefinition()) {
15452 // C++ [class.union]p1: An object of a class with a non-trivial
15453 // constructor, a non-trivial copy constructor, a non-trivial
15454 // destructor, or a non-trivial copy assignment operator
15455 // cannot be a member of a union, nor can an array of such
15457 if (CheckNontrivialField(NewFD))
15458 NewFD->setInvalidDecl();
15462 // C++ [class.union]p1: If a union contains a member of reference type,
15463 // the program is ill-formed, except when compiling with MSVC extensions
15465 if (EltTy->isReferenceType()) {
15466 Diag(NewFD->getLocation(), getLangOpts().MicrosoftExt ?
15467 diag::ext_union_member_of_reference_type :
15468 diag::err_union_member_of_reference_type)
15469 << NewFD->getDeclName() << EltTy;
15470 if (!getLangOpts().MicrosoftExt)
15471 NewFD->setInvalidDecl();
15476 // FIXME: We need to pass in the attributes given an AST
15477 // representation, not a parser representation.
15479 // FIXME: The current scope is almost... but not entirely... correct here.
15480 ProcessDeclAttributes(getCurScope(), NewFD, *D);
15482 if (NewFD->hasAttrs())
15483 CheckAlignasUnderalignment(NewFD);
15486 // In auto-retain/release, infer strong retension for fields of
15487 // retainable type.
15488 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewFD))
15489 NewFD->setInvalidDecl();
15491 if (T.isObjCGCWeak())
15492 Diag(Loc, diag::warn_attribute_weak_on_field);
15494 NewFD->setAccess(AS);
15498 bool Sema::CheckNontrivialField(FieldDecl *FD) {
15500 assert(getLangOpts().CPlusPlus && "valid check only for C++");
15502 if (FD->isInvalidDecl() || FD->getType()->isDependentType())
15505 QualType EltTy = Context.getBaseElementType(FD->getType());
15506 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
15507 CXXRecordDecl *RDecl = cast<CXXRecordDecl>(RT->getDecl());
15508 if (RDecl->getDefinition()) {
15509 // We check for copy constructors before constructors
15510 // because otherwise we'll never get complaints about
15511 // copy constructors.
15513 CXXSpecialMember member = CXXInvalid;
15514 // We're required to check for any non-trivial constructors. Since the
15515 // implicit default constructor is suppressed if there are any
15516 // user-declared constructors, we just need to check that there is a
15517 // trivial default constructor and a trivial copy constructor. (We don't
15518 // worry about move constructors here, since this is a C++98 check.)
15519 if (RDecl->hasNonTrivialCopyConstructor())
15520 member = CXXCopyConstructor;
15521 else if (!RDecl->hasTrivialDefaultConstructor())
15522 member = CXXDefaultConstructor;
15523 else if (RDecl->hasNonTrivialCopyAssignment())
15524 member = CXXCopyAssignment;
15525 else if (RDecl->hasNonTrivialDestructor())
15526 member = CXXDestructor;
15528 if (member != CXXInvalid) {
15529 if (!getLangOpts().CPlusPlus11 &&
15530 getLangOpts().ObjCAutoRefCount && RDecl->hasObjectMember()) {
15531 // Objective-C++ ARC: it is an error to have a non-trivial field of
15532 // a union. However, system headers in Objective-C programs
15533 // occasionally have Objective-C lifetime objects within unions,
15534 // and rather than cause the program to fail, we make those
15535 // members unavailable.
15536 SourceLocation Loc = FD->getLocation();
15537 if (getSourceManager().isInSystemHeader(Loc)) {
15538 if (!FD->hasAttr<UnavailableAttr>())
15539 FD->addAttr(UnavailableAttr::CreateImplicit(Context, "",
15540 UnavailableAttr::IR_ARCFieldWithOwnership, Loc));
15545 Diag(FD->getLocation(), getLangOpts().CPlusPlus11 ?
15546 diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member :
15547 diag::err_illegal_union_or_anon_struct_member)
15548 << FD->getParent()->isUnion() << FD->getDeclName() << member;
15549 DiagnoseNontrivial(RDecl, member);
15550 return !getLangOpts().CPlusPlus11;
15558 /// TranslateIvarVisibility - Translate visibility from a token ID to an
15559 /// AST enum value.
15560 static ObjCIvarDecl::AccessControl
15561 TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) {
15562 switch (ivarVisibility) {
15563 default: llvm_unreachable("Unknown visitibility kind");
15564 case tok::objc_private: return ObjCIvarDecl::Private;
15565 case tok::objc_public: return ObjCIvarDecl::Public;
15566 case tok::objc_protected: return ObjCIvarDecl::Protected;
15567 case tok::objc_package: return ObjCIvarDecl::Package;
15571 /// ActOnIvar - Each ivar field of an objective-c class is passed into this
15572 /// in order to create an IvarDecl object for it.
15573 Decl *Sema::ActOnIvar(Scope *S,
15574 SourceLocation DeclStart,
15575 Declarator &D, Expr *BitfieldWidth,
15576 tok::ObjCKeywordKind Visibility) {
15578 IdentifierInfo *II = D.getIdentifier();
15579 Expr *BitWidth = (Expr*)BitfieldWidth;
15580 SourceLocation Loc = DeclStart;
15581 if (II) Loc = D.getIdentifierLoc();
15583 // FIXME: Unnamed fields can be handled in various different ways, for
15584 // example, unnamed unions inject all members into the struct namespace!
15586 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15587 QualType T = TInfo->getType();
15590 // 6.7.2.1p3, 6.7.2.1p4
15591 BitWidth = VerifyBitField(Loc, II, T, /*IsMsStruct*/false, BitWidth).get();
15593 D.setInvalidType();
15600 if (T->isReferenceType()) {
15601 Diag(Loc, diag::err_ivar_reference_type);
15602 D.setInvalidType();
15604 // C99 6.7.2.1p8: A member of a structure or union may have any type other
15605 // than a variably modified type.
15606 else if (T->isVariablyModifiedType()) {
15607 Diag(Loc, diag::err_typecheck_ivar_variable_size);
15608 D.setInvalidType();
15611 // Get the visibility (access control) for this ivar.
15612 ObjCIvarDecl::AccessControl ac =
15613 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility)
15614 : ObjCIvarDecl::None;
15615 // Must set ivar's DeclContext to its enclosing interface.
15616 ObjCContainerDecl *EnclosingDecl = cast<ObjCContainerDecl>(CurContext);
15617 if (!EnclosingDecl || EnclosingDecl->isInvalidDecl())
15619 ObjCContainerDecl *EnclosingContext;
15620 if (ObjCImplementationDecl *IMPDecl =
15621 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
15622 if (LangOpts.ObjCRuntime.isFragile()) {
15623 // Case of ivar declared in an implementation. Context is that of its class.
15624 EnclosingContext = IMPDecl->getClassInterface();
15625 assert(EnclosingContext && "Implementation has no class interface!");
15628 EnclosingContext = EnclosingDecl;
15630 if (ObjCCategoryDecl *CDecl =
15631 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) {
15632 if (LangOpts.ObjCRuntime.isFragile() || !CDecl->IsClassExtension()) {
15633 Diag(Loc, diag::err_misplaced_ivar) << CDecl->IsClassExtension();
15637 EnclosingContext = EnclosingDecl;
15640 // Construct the decl.
15641 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, EnclosingContext,
15642 DeclStart, Loc, II, T,
15643 TInfo, ac, (Expr *)BitfieldWidth);
15646 NamedDecl *PrevDecl = LookupSingleName(S, II, Loc, LookupMemberName,
15647 ForVisibleRedeclaration);
15648 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S)
15649 && !isa<TagDecl>(PrevDecl)) {
15650 Diag(Loc, diag::err_duplicate_member) << II;
15651 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
15652 NewID->setInvalidDecl();
15656 // Process attributes attached to the ivar.
15657 ProcessDeclAttributes(S, NewID, D);
15659 if (D.isInvalidType())
15660 NewID->setInvalidDecl();
15662 // In ARC, infer 'retaining' for ivars of retainable type.
15663 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewID))
15664 NewID->setInvalidDecl();
15666 if (D.getDeclSpec().isModulePrivateSpecified())
15667 NewID->setModulePrivate();
15670 // FIXME: When interfaces are DeclContexts, we'll need to add
15671 // these to the interface.
15673 IdResolver.AddDecl(NewID);
15676 if (LangOpts.ObjCRuntime.isNonFragile() &&
15677 !NewID->isInvalidDecl() && isa<ObjCInterfaceDecl>(EnclosingDecl))
15678 Diag(Loc, diag::warn_ivars_in_interface);
15683 /// ActOnLastBitfield - This routine handles synthesized bitfields rules for
15684 /// class and class extensions. For every class \@interface and class
15685 /// extension \@interface, if the last ivar is a bitfield of any type,
15686 /// then add an implicit `char :0` ivar to the end of that interface.
15687 void Sema::ActOnLastBitfield(SourceLocation DeclLoc,
15688 SmallVectorImpl<Decl *> &AllIvarDecls) {
15689 if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty())
15692 Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1];
15693 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(ivarDecl);
15695 if (!Ivar->isBitField() || Ivar->isZeroLengthBitField(Context))
15697 ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CurContext);
15699 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(CurContext)) {
15700 if (!CD->IsClassExtension())
15703 // No need to add this to end of @implementation.
15707 // All conditions are met. Add a new bitfield to the tail end of ivars.
15708 llvm::APInt Zero(Context.getTypeSize(Context.IntTy), 0);
15709 Expr * BW = IntegerLiteral::Create(Context, Zero, Context.IntTy, DeclLoc);
15711 Ivar = ObjCIvarDecl::Create(Context, cast<ObjCContainerDecl>(CurContext),
15712 DeclLoc, DeclLoc, nullptr,
15714 Context.getTrivialTypeSourceInfo(Context.CharTy,
15716 ObjCIvarDecl::Private, BW,
15718 AllIvarDecls.push_back(Ivar);
15721 void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
15722 ArrayRef<Decl *> Fields, SourceLocation LBrac,
15723 SourceLocation RBrac,
15724 const ParsedAttributesView &Attrs) {
15725 assert(EnclosingDecl && "missing record or interface decl");
15727 // If this is an Objective-C @implementation or category and we have
15728 // new fields here we should reset the layout of the interface since
15729 // it will now change.
15730 if (!Fields.empty() && isa<ObjCContainerDecl>(EnclosingDecl)) {
15731 ObjCContainerDecl *DC = cast<ObjCContainerDecl>(EnclosingDecl);
15732 switch (DC->getKind()) {
15734 case Decl::ObjCCategory:
15735 Context.ResetObjCLayout(cast<ObjCCategoryDecl>(DC)->getClassInterface());
15737 case Decl::ObjCImplementation:
15739 ResetObjCLayout(cast<ObjCImplementationDecl>(DC)->getClassInterface());
15744 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
15745 CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(EnclosingDecl);
15747 // Start counting up the number of named members; make sure to include
15748 // members of anonymous structs and unions in the total.
15749 unsigned NumNamedMembers = 0;
15751 for (const auto *I : Record->decls()) {
15752 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
15753 if (IFD->getDeclName())
15758 // Verify that all the fields are okay.
15759 SmallVector<FieldDecl*, 32> RecFields;
15761 bool ObjCFieldLifetimeErrReported = false;
15762 for (ArrayRef<Decl *>::iterator i = Fields.begin(), end = Fields.end();
15764 FieldDecl *FD = cast<FieldDecl>(*i);
15766 // Get the type for the field.
15767 const Type *FDTy = FD->getType().getTypePtr();
15769 if (!FD->isAnonymousStructOrUnion()) {
15770 // Remember all fields written by the user.
15771 RecFields.push_back(FD);
15774 // If the field is already invalid for some reason, don't emit more
15775 // diagnostics about it.
15776 if (FD->isInvalidDecl()) {
15777 EnclosingDecl->setInvalidDecl();
15782 // A structure or union shall not contain a member with
15783 // incomplete or function type (hence, a structure shall not
15784 // contain an instance of itself, but may contain a pointer to
15785 // an instance of itself), except that the last member of a
15786 // structure with more than one named member may have incomplete
15787 // array type; such a structure (and any union containing,
15788 // possibly recursively, a member that is such a structure)
15789 // shall not be a member of a structure or an element of an
15791 bool IsLastField = (i + 1 == Fields.end());
15792 if (FDTy->isFunctionType()) {
15793 // Field declared as a function.
15794 Diag(FD->getLocation(), diag::err_field_declared_as_function)
15795 << FD->getDeclName();
15796 FD->setInvalidDecl();
15797 EnclosingDecl->setInvalidDecl();
15799 } else if (FDTy->isIncompleteArrayType() &&
15800 (Record || isa<ObjCContainerDecl>(EnclosingDecl))) {
15802 // Flexible array member.
15803 // Microsoft and g++ is more permissive regarding flexible array.
15804 // It will accept flexible array in union and also
15805 // as the sole element of a struct/class.
15806 unsigned DiagID = 0;
15807 if (!Record->isUnion() && !IsLastField) {
15808 Diag(FD->getLocation(), diag::err_flexible_array_not_at_end)
15809 << FD->getDeclName() << FD->getType() << Record->getTagKind();
15810 Diag((*(i + 1))->getLocation(), diag::note_next_field_declaration);
15811 FD->setInvalidDecl();
15812 EnclosingDecl->setInvalidDecl();
15814 } else if (Record->isUnion())
15815 DiagID = getLangOpts().MicrosoftExt
15816 ? diag::ext_flexible_array_union_ms
15817 : getLangOpts().CPlusPlus
15818 ? diag::ext_flexible_array_union_gnu
15819 : diag::err_flexible_array_union;
15820 else if (NumNamedMembers < 1)
15821 DiagID = getLangOpts().MicrosoftExt
15822 ? diag::ext_flexible_array_empty_aggregate_ms
15823 : getLangOpts().CPlusPlus
15824 ? diag::ext_flexible_array_empty_aggregate_gnu
15825 : diag::err_flexible_array_empty_aggregate;
15828 Diag(FD->getLocation(), DiagID) << FD->getDeclName()
15829 << Record->getTagKind();
15830 // While the layout of types that contain virtual bases is not specified
15831 // by the C++ standard, both the Itanium and Microsoft C++ ABIs place
15832 // virtual bases after the derived members. This would make a flexible
15833 // array member declared at the end of an object not adjacent to the end
15835 if (CXXRecord && CXXRecord->getNumVBases() != 0)
15836 Diag(FD->getLocation(), diag::err_flexible_array_virtual_base)
15837 << FD->getDeclName() << Record->getTagKind();
15838 if (!getLangOpts().C99)
15839 Diag(FD->getLocation(), diag::ext_c99_flexible_array_member)
15840 << FD->getDeclName() << Record->getTagKind();
15842 // If the element type has a non-trivial destructor, we would not
15843 // implicitly destroy the elements, so disallow it for now.
15845 // FIXME: GCC allows this. We should probably either implicitly delete
15846 // the destructor of the containing class, or just allow this.
15847 QualType BaseElem = Context.getBaseElementType(FD->getType());
15848 if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) {
15849 Diag(FD->getLocation(), diag::err_flexible_array_has_nontrivial_dtor)
15850 << FD->getDeclName() << FD->getType();
15851 FD->setInvalidDecl();
15852 EnclosingDecl->setInvalidDecl();
15855 // Okay, we have a legal flexible array member at the end of the struct.
15856 Record->setHasFlexibleArrayMember(true);
15858 // In ObjCContainerDecl ivars with incomplete array type are accepted,
15859 // unless they are followed by another ivar. That check is done
15860 // elsewhere, after synthesized ivars are known.
15862 } else if (!FDTy->isDependentType() &&
15863 RequireCompleteType(FD->getLocation(), FD->getType(),
15864 diag::err_field_incomplete)) {
15866 FD->setInvalidDecl();
15867 EnclosingDecl->setInvalidDecl();
15869 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) {
15870 if (Record && FDTTy->getDecl()->hasFlexibleArrayMember()) {
15871 // A type which contains a flexible array member is considered to be a
15872 // flexible array member.
15873 Record->setHasFlexibleArrayMember(true);
15874 if (!Record->isUnion()) {
15875 // If this is a struct/class and this is not the last element, reject
15876 // it. Note that GCC supports variable sized arrays in the middle of
15879 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct)
15880 << FD->getDeclName() << FD->getType();
15882 // We support flexible arrays at the end of structs in
15883 // other structs as an extension.
15884 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct)
15885 << FD->getDeclName();
15889 if (isa<ObjCContainerDecl>(EnclosingDecl) &&
15890 RequireNonAbstractType(FD->getLocation(), FD->getType(),
15891 diag::err_abstract_type_in_decl,
15892 AbstractIvarType)) {
15893 // Ivars can not have abstract class types
15894 FD->setInvalidDecl();
15896 if (Record && FDTTy->getDecl()->hasObjectMember())
15897 Record->setHasObjectMember(true);
15898 if (Record && FDTTy->getDecl()->hasVolatileMember())
15899 Record->setHasVolatileMember(true);
15900 } else if (FDTy->isObjCObjectType()) {
15901 /// A field cannot be an Objective-c object
15902 Diag(FD->getLocation(), diag::err_statically_allocated_object)
15903 << FixItHint::CreateInsertion(FD->getLocation(), "*");
15904 QualType T = Context.getObjCObjectPointerType(FD->getType());
15906 } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
15907 Record && !ObjCFieldLifetimeErrReported && Record->isUnion()) {
15908 // It's an error in ARC or Weak if a field has lifetime.
15909 // We don't want to report this in a system header, though,
15910 // so we just make the field unavailable.
15911 // FIXME: that's really not sufficient; we need to make the type
15912 // itself invalid to, say, initialize or copy.
15913 QualType T = FD->getType();
15914 if (T.hasNonTrivialObjCLifetime()) {
15915 SourceLocation loc = FD->getLocation();
15916 if (getSourceManager().isInSystemHeader(loc)) {
15917 if (!FD->hasAttr<UnavailableAttr>()) {
15918 FD->addAttr(UnavailableAttr::CreateImplicit(Context, "",
15919 UnavailableAttr::IR_ARCFieldWithOwnership, loc));
15922 Diag(FD->getLocation(), diag::err_arc_objc_object_in_tag)
15923 << T->isBlockPointerType() << Record->getTagKind();
15925 ObjCFieldLifetimeErrReported = true;
15927 } else if (getLangOpts().ObjC &&
15928 getLangOpts().getGC() != LangOptions::NonGC &&
15929 Record && !Record->hasObjectMember()) {
15930 if (FD->getType()->isObjCObjectPointerType() ||
15931 FD->getType().isObjCGCStrong())
15932 Record->setHasObjectMember(true);
15933 else if (Context.getAsArrayType(FD->getType())) {
15934 QualType BaseType = Context.getBaseElementType(FD->getType());
15935 if (BaseType->isRecordType() &&
15936 BaseType->getAs<RecordType>()->getDecl()->hasObjectMember())
15937 Record->setHasObjectMember(true);
15938 else if (BaseType->isObjCObjectPointerType() ||
15939 BaseType.isObjCGCStrong())
15940 Record->setHasObjectMember(true);
15944 if (Record && !getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>()) {
15945 QualType FT = FD->getType();
15946 if (FT.isNonTrivialToPrimitiveDefaultInitialize())
15947 Record->setNonTrivialToPrimitiveDefaultInitialize(true);
15948 QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy();
15949 if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial)
15950 Record->setNonTrivialToPrimitiveCopy(true);
15951 if (FT.isDestructedType()) {
15952 Record->setNonTrivialToPrimitiveDestroy(true);
15953 Record->setParamDestroyedInCallee(true);
15956 if (const auto *RT = FT->getAs<RecordType>()) {
15957 if (RT->getDecl()->getArgPassingRestrictions() ==
15958 RecordDecl::APK_CanNeverPassInRegs)
15959 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
15960 } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak)
15961 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
15964 if (Record && FD->getType().isVolatileQualified())
15965 Record->setHasVolatileMember(true);
15966 // Keep track of the number of named members.
15967 if (FD->getIdentifier())
15971 // Okay, we successfully defined 'Record'.
15973 bool Completed = false;
15975 if (!CXXRecord->isInvalidDecl()) {
15976 // Set access bits correctly on the directly-declared conversions.
15977 for (CXXRecordDecl::conversion_iterator
15978 I = CXXRecord->conversion_begin(),
15979 E = CXXRecord->conversion_end(); I != E; ++I)
15980 I.setAccess((*I)->getAccess());
15983 if (!CXXRecord->isDependentType()) {
15984 // Add any implicitly-declared members to this class.
15985 AddImplicitlyDeclaredMembersToClass(CXXRecord);
15987 if (!CXXRecord->isInvalidDecl()) {
15988 // If we have virtual base classes, we may end up finding multiple
15989 // final overriders for a given virtual function. Check for this
15991 if (CXXRecord->getNumVBases()) {
15992 CXXFinalOverriderMap FinalOverriders;
15993 CXXRecord->getFinalOverriders(FinalOverriders);
15995 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
15996 MEnd = FinalOverriders.end();
15998 for (OverridingMethods::iterator SO = M->second.begin(),
15999 SOEnd = M->second.end();
16000 SO != SOEnd; ++SO) {
16001 assert(SO->second.size() > 0 &&
16002 "Virtual function without overriding functions?");
16003 if (SO->second.size() == 1)
16006 // C++ [class.virtual]p2:
16007 // In a derived class, if a virtual member function of a base
16008 // class subobject has more than one final overrider the
16009 // program is ill-formed.
16010 Diag(Record->getLocation(), diag::err_multiple_final_overriders)
16011 << (const NamedDecl *)M->first << Record;
16012 Diag(M->first->getLocation(),
16013 diag::note_overridden_virtual_function);
16014 for (OverridingMethods::overriding_iterator
16015 OM = SO->second.begin(),
16016 OMEnd = SO->second.end();
16018 Diag(OM->Method->getLocation(), diag::note_final_overrider)
16019 << (const NamedDecl *)M->first << OM->Method->getParent();
16021 Record->setInvalidDecl();
16024 CXXRecord->completeDefinition(&FinalOverriders);
16032 Record->completeDefinition();
16034 // Handle attributes before checking the layout.
16035 ProcessDeclAttributeList(S, Record, Attrs);
16037 // We may have deferred checking for a deleted destructor. Check now.
16039 auto *Dtor = CXXRecord->getDestructor();
16040 if (Dtor && Dtor->isImplicit() &&
16041 ShouldDeleteSpecialMember(Dtor, CXXDestructor)) {
16042 CXXRecord->setImplicitDestructorIsDeleted();
16043 SetDeclDeleted(Dtor, CXXRecord->getLocation());
16047 if (Record->hasAttrs()) {
16048 CheckAlignasUnderalignment(Record);
16050 if (const MSInheritanceAttr *IA = Record->getAttr<MSInheritanceAttr>())
16051 checkMSInheritanceAttrOnDefinition(cast<CXXRecordDecl>(Record),
16052 IA->getRange(), IA->getBestCase(),
16053 IA->getSemanticSpelling());
16056 // Check if the structure/union declaration is a type that can have zero
16057 // size in C. For C this is a language extension, for C++ it may cause
16058 // compatibility problems.
16059 bool CheckForZeroSize;
16060 if (!getLangOpts().CPlusPlus) {
16061 CheckForZeroSize = true;
16063 // For C++ filter out types that cannot be referenced in C code.
16064 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record);
16066 CXXRecord->getLexicalDeclContext()->isExternCContext() &&
16067 !CXXRecord->isDependentType() &&
16068 CXXRecord->isCLike();
16070 if (CheckForZeroSize) {
16071 bool ZeroSize = true;
16072 bool IsEmpty = true;
16073 unsigned NonBitFields = 0;
16074 for (RecordDecl::field_iterator I = Record->field_begin(),
16075 E = Record->field_end();
16076 (NonBitFields == 0 || ZeroSize) && I != E; ++I) {
16078 if (I->isUnnamedBitfield()) {
16079 if (!I->isZeroLengthBitField(Context))
16083 QualType FieldType = I->getType();
16084 if (FieldType->isIncompleteType() ||
16085 !Context.getTypeSizeInChars(FieldType).isZero())
16090 // Empty structs are an extension in C (C99 6.7.2.1p7). They are
16091 // allowed in C++, but warn if its declaration is inside
16092 // extern "C" block.
16094 Diag(RecLoc, getLangOpts().CPlusPlus ?
16095 diag::warn_zero_size_struct_union_in_extern_c :
16096 diag::warn_zero_size_struct_union_compat)
16097 << IsEmpty << Record->isUnion() << (NonBitFields > 1);
16100 // Structs without named members are extension in C (C99 6.7.2.1p7),
16101 // but are accepted by GCC.
16102 if (NonBitFields == 0 && !getLangOpts().CPlusPlus) {
16103 Diag(RecLoc, IsEmpty ? diag::ext_empty_struct_union :
16104 diag::ext_no_named_members_in_struct_union)
16105 << Record->isUnion();
16109 ObjCIvarDecl **ClsFields =
16110 reinterpret_cast<ObjCIvarDecl**>(RecFields.data());
16111 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) {
16112 ID->setEndOfDefinitionLoc(RBrac);
16113 // Add ivar's to class's DeclContext.
16114 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
16115 ClsFields[i]->setLexicalDeclContext(ID);
16116 ID->addDecl(ClsFields[i]);
16118 // Must enforce the rule that ivars in the base classes may not be
16120 if (ID->getSuperClass())
16121 DiagnoseDuplicateIvars(ID, ID->getSuperClass());
16122 } else if (ObjCImplementationDecl *IMPDecl =
16123 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
16124 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
16125 for (unsigned I = 0, N = RecFields.size(); I != N; ++I)
16126 // Ivar declared in @implementation never belongs to the implementation.
16127 // Only it is in implementation's lexical context.
16128 ClsFields[I]->setLexicalDeclContext(IMPDecl);
16129 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
16130 IMPDecl->setIvarLBraceLoc(LBrac);
16131 IMPDecl->setIvarRBraceLoc(RBrac);
16132 } else if (ObjCCategoryDecl *CDecl =
16133 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) {
16134 // case of ivars in class extension; all other cases have been
16135 // reported as errors elsewhere.
16136 // FIXME. Class extension does not have a LocEnd field.
16137 // CDecl->setLocEnd(RBrac);
16138 // Add ivar's to class extension's DeclContext.
16139 // Diagnose redeclaration of private ivars.
16140 ObjCInterfaceDecl *IDecl = CDecl->getClassInterface();
16141 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
16143 if (const ObjCIvarDecl *ClsIvar =
16144 IDecl->getIvarDecl(ClsFields[i]->getIdentifier())) {
16145 Diag(ClsFields[i]->getLocation(),
16146 diag::err_duplicate_ivar_declaration);
16147 Diag(ClsIvar->getLocation(), diag::note_previous_definition);
16150 for (const auto *Ext : IDecl->known_extensions()) {
16151 if (const ObjCIvarDecl *ClsExtIvar
16152 = Ext->getIvarDecl(ClsFields[i]->getIdentifier())) {
16153 Diag(ClsFields[i]->getLocation(),
16154 diag::err_duplicate_ivar_declaration);
16155 Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
16160 ClsFields[i]->setLexicalDeclContext(CDecl);
16161 CDecl->addDecl(ClsFields[i]);
16163 CDecl->setIvarLBraceLoc(LBrac);
16164 CDecl->setIvarRBraceLoc(RBrac);
16169 /// Determine whether the given integral value is representable within
16170 /// the given type T.
16171 static bool isRepresentableIntegerValue(ASTContext &Context,
16172 llvm::APSInt &Value,
16174 assert((T->isIntegralType(Context) || T->isEnumeralType()) &&
16175 "Integral type required!");
16176 unsigned BitWidth = Context.getIntWidth(T);
16178 if (Value.isUnsigned() || Value.isNonNegative()) {
16179 if (T->isSignedIntegerOrEnumerationType())
16181 return Value.getActiveBits() <= BitWidth;
16183 return Value.getMinSignedBits() <= BitWidth;
16186 // Given an integral type, return the next larger integral type
16187 // (or a NULL type of no such type exists).
16188 static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) {
16189 // FIXME: Int128/UInt128 support, which also needs to be introduced into
16190 // enum checking below.
16191 assert((T->isIntegralType(Context) ||
16192 T->isEnumeralType()) && "Integral type required!");
16193 const unsigned NumTypes = 4;
16194 QualType SignedIntegralTypes[NumTypes] = {
16195 Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy
16197 QualType UnsignedIntegralTypes[NumTypes] = {
16198 Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy,
16199 Context.UnsignedLongLongTy
16202 unsigned BitWidth = Context.getTypeSize(T);
16203 QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes
16204 : UnsignedIntegralTypes;
16205 for (unsigned I = 0; I != NumTypes; ++I)
16206 if (Context.getTypeSize(Types[I]) > BitWidth)
16212 EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum,
16213 EnumConstantDecl *LastEnumConst,
16214 SourceLocation IdLoc,
16215 IdentifierInfo *Id,
16217 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
16218 llvm::APSInt EnumVal(IntWidth);
16221 if (Val && DiagnoseUnexpandedParameterPack(Val, UPPC_EnumeratorValue))
16225 Val = DefaultLvalueConversion(Val).get();
16228 if (Enum->isDependentType() || Val->isTypeDependent())
16229 EltTy = Context.DependentTy;
16231 if (getLangOpts().CPlusPlus11 && Enum->isFixed() &&
16232 !getLangOpts().MSVCCompat) {
16233 // C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the
16234 // constant-expression in the enumerator-definition shall be a converted
16235 // constant expression of the underlying type.
16236 EltTy = Enum->getIntegerType();
16237 ExprResult Converted =
16238 CheckConvertedConstantExpression(Val, EltTy, EnumVal,
16240 if (Converted.isInvalid())
16243 Val = Converted.get();
16244 } else if (!Val->isValueDependent() &&
16245 !(Val = VerifyIntegerConstantExpression(Val,
16246 &EnumVal).get())) {
16247 // C99 6.7.2.2p2: Make sure we have an integer constant expression.
16249 if (Enum->isComplete()) {
16250 EltTy = Enum->getIntegerType();
16252 // In Obj-C and Microsoft mode, require the enumeration value to be
16253 // representable in the underlying type of the enumeration. In C++11,
16254 // we perform a non-narrowing conversion as part of converted constant
16255 // expression checking.
16256 if (!isRepresentableIntegerValue(Context, EnumVal, EltTy)) {
16257 if (getLangOpts().MSVCCompat) {
16258 Diag(IdLoc, diag::ext_enumerator_too_large) << EltTy;
16259 Val = ImpCastExprToType(Val, EltTy, CK_IntegralCast).get();
16261 Diag(IdLoc, diag::err_enumerator_too_large) << EltTy;
16263 Val = ImpCastExprToType(Val, EltTy,
16264 EltTy->isBooleanType() ?
16265 CK_IntegralToBoolean : CK_IntegralCast)
16267 } else if (getLangOpts().CPlusPlus) {
16268 // C++11 [dcl.enum]p5:
16269 // If the underlying type is not fixed, the type of each enumerator
16270 // is the type of its initializing value:
16271 // - If an initializer is specified for an enumerator, the
16272 // initializing value has the same type as the expression.
16273 EltTy = Val->getType();
16276 // The expression that defines the value of an enumeration constant
16277 // shall be an integer constant expression that has a value
16278 // representable as an int.
16280 // Complain if the value is not representable in an int.
16281 if (!isRepresentableIntegerValue(Context, EnumVal, Context.IntTy))
16282 Diag(IdLoc, diag::ext_enum_value_not_int)
16283 << EnumVal.toString(10) << Val->getSourceRange()
16284 << (EnumVal.isUnsigned() || EnumVal.isNonNegative());
16285 else if (!Context.hasSameType(Val->getType(), Context.IntTy)) {
16286 // Force the type of the expression to 'int'.
16287 Val = ImpCastExprToType(Val, Context.IntTy, CK_IntegralCast).get();
16289 EltTy = Val->getType();
16296 if (Enum->isDependentType())
16297 EltTy = Context.DependentTy;
16298 else if (!LastEnumConst) {
16299 // C++0x [dcl.enum]p5:
16300 // If the underlying type is not fixed, the type of each enumerator
16301 // is the type of its initializing value:
16302 // - If no initializer is specified for the first enumerator, the
16303 // initializing value has an unspecified integral type.
16305 // GCC uses 'int' for its unspecified integral type, as does
16307 if (Enum->isFixed()) {
16308 EltTy = Enum->getIntegerType();
16311 EltTy = Context.IntTy;
16314 // Assign the last value + 1.
16315 EnumVal = LastEnumConst->getInitVal();
16317 EltTy = LastEnumConst->getType();
16319 // Check for overflow on increment.
16320 if (EnumVal < LastEnumConst->getInitVal()) {
16321 // C++0x [dcl.enum]p5:
16322 // If the underlying type is not fixed, the type of each enumerator
16323 // is the type of its initializing value:
16325 // - Otherwise the type of the initializing value is the same as
16326 // the type of the initializing value of the preceding enumerator
16327 // unless the incremented value is not representable in that type,
16328 // in which case the type is an unspecified integral type
16329 // sufficient to contain the incremented value. If no such type
16330 // exists, the program is ill-formed.
16331 QualType T = getNextLargerIntegralType(Context, EltTy);
16332 if (T.isNull() || Enum->isFixed()) {
16333 // There is no integral type larger enough to represent this
16334 // value. Complain, then allow the value to wrap around.
16335 EnumVal = LastEnumConst->getInitVal();
16336 EnumVal = EnumVal.zext(EnumVal.getBitWidth() * 2);
16338 if (Enum->isFixed())
16339 // When the underlying type is fixed, this is ill-formed.
16340 Diag(IdLoc, diag::err_enumerator_wrapped)
16341 << EnumVal.toString(10)
16344 Diag(IdLoc, diag::ext_enumerator_increment_too_large)
16345 << EnumVal.toString(10);
16350 // Retrieve the last enumerator's value, extent that type to the
16351 // type that is supposed to be large enough to represent the incremented
16352 // value, then increment.
16353 EnumVal = LastEnumConst->getInitVal();
16354 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
16355 EnumVal = EnumVal.zextOrTrunc(Context.getIntWidth(EltTy));
16358 // If we're not in C++, diagnose the overflow of enumerator values,
16359 // which in C99 means that the enumerator value is not representable in
16360 // an int (C99 6.7.2.2p2). However, we support GCC's extension that
16361 // permits enumerator values that are representable in some larger
16363 if (!getLangOpts().CPlusPlus && !T.isNull())
16364 Diag(IdLoc, diag::warn_enum_value_overflow);
16365 } else if (!getLangOpts().CPlusPlus &&
16366 !isRepresentableIntegerValue(Context, EnumVal, EltTy)) {
16367 // Enforce C99 6.7.2.2p2 even when we compute the next value.
16368 Diag(IdLoc, diag::ext_enum_value_not_int)
16369 << EnumVal.toString(10) << 1;
16374 if (!EltTy->isDependentType()) {
16375 // Make the enumerator value match the signedness and size of the
16376 // enumerator's type.
16377 EnumVal = EnumVal.extOrTrunc(Context.getIntWidth(EltTy));
16378 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
16381 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy,
16385 Sema::SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
16386 SourceLocation IILoc) {
16387 if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) ||
16388 !getLangOpts().CPlusPlus)
16389 return SkipBodyInfo();
16391 // We have an anonymous enum definition. Look up the first enumerator to
16392 // determine if we should merge the definition with an existing one and
16394 NamedDecl *PrevDecl = LookupSingleName(S, II, IILoc, LookupOrdinaryName,
16395 forRedeclarationInCurContext());
16396 auto *PrevECD = dyn_cast_or_null<EnumConstantDecl>(PrevDecl);
16398 return SkipBodyInfo();
16400 EnumDecl *PrevED = cast<EnumDecl>(PrevECD->getDeclContext());
16402 if (!PrevED->getDeclName() && !hasVisibleDefinition(PrevED, &Hidden)) {
16404 Skip.Previous = Hidden;
16408 return SkipBodyInfo();
16411 Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
16412 SourceLocation IdLoc, IdentifierInfo *Id,
16413 const ParsedAttributesView &Attrs,
16414 SourceLocation EqualLoc, Expr *Val) {
16415 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl);
16416 EnumConstantDecl *LastEnumConst =
16417 cast_or_null<EnumConstantDecl>(lastEnumConst);
16419 // The scope passed in may not be a decl scope. Zip up the scope tree until
16420 // we find one that is.
16421 S = getNonFieldDeclScope(S);
16423 // Verify that there isn't already something declared with this name in this
16425 LookupResult R(*this, Id, IdLoc, LookupOrdinaryName, ForVisibleRedeclaration);
16427 NamedDecl *PrevDecl = R.getAsSingle<NamedDecl>();
16429 if (PrevDecl && PrevDecl->isTemplateParameter()) {
16430 // Maybe we will complain about the shadowed template parameter.
16431 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl);
16432 // Just pretend that we didn't see the previous declaration.
16433 PrevDecl = nullptr;
16436 // C++ [class.mem]p15:
16437 // If T is the name of a class, then each of the following shall have a name
16438 // different from T:
16439 // - every enumerator of every member of class T that is an unscoped
16441 if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped())
16442 DiagnoseClassNameShadow(TheEnumDecl->getDeclContext(),
16443 DeclarationNameInfo(Id, IdLoc));
16445 EnumConstantDecl *New =
16446 CheckEnumConstant(TheEnumDecl, LastEnumConst, IdLoc, Id, Val);
16451 if (!TheEnumDecl->isScoped() && isa<ValueDecl>(PrevDecl)) {
16452 // Check for other kinds of shadowing not already handled.
16453 CheckShadow(New, PrevDecl, R);
16456 // When in C++, we may get a TagDecl with the same name; in this case the
16457 // enum constant will 'hide' the tag.
16458 assert((getLangOpts().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
16459 "Received TagDecl when not in C++!");
16460 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) {
16461 if (isa<EnumConstantDecl>(PrevDecl))
16462 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
16464 Diag(IdLoc, diag::err_redefinition) << Id;
16465 notePreviousDefinition(PrevDecl, IdLoc);
16470 // Process attributes.
16471 ProcessDeclAttributeList(S, New, Attrs);
16472 AddPragmaAttributes(S, New);
16474 // Register this decl in the current scope stack.
16475 New->setAccess(TheEnumDecl->getAccess());
16476 PushOnScopeChains(New, S);
16478 ActOnDocumentableDecl(New);
16483 // Returns true when the enum initial expression does not trigger the
16484 // duplicate enum warning. A few common cases are exempted as follows:
16485 // Element2 = Element1
16486 // Element2 = Element1 + 1
16487 // Element2 = Element1 - 1
16488 // Where Element2 and Element1 are from the same enum.
16489 static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) {
16490 Expr *InitExpr = ECD->getInitExpr();
16493 InitExpr = InitExpr->IgnoreImpCasts();
16495 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(InitExpr)) {
16496 if (!BO->isAdditiveOp())
16498 IntegerLiteral *IL = dyn_cast<IntegerLiteral>(BO->getRHS());
16501 if (IL->getValue() != 1)
16504 InitExpr = BO->getLHS();
16507 // This checks if the elements are from the same enum.
16508 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(InitExpr);
16512 EnumConstantDecl *EnumConstant = dyn_cast<EnumConstantDecl>(DRE->getDecl());
16516 if (cast<EnumDecl>(TagDecl::castFromDeclContext(ECD->getDeclContext())) !=
16523 // Emits a warning when an element is implicitly set a value that
16524 // a previous element has already been set to.
16525 static void CheckForDuplicateEnumValues(Sema &S, ArrayRef<Decl *> Elements,
16526 EnumDecl *Enum, QualType EnumType) {
16527 // Avoid anonymous enums
16528 if (!Enum->getIdentifier())
16531 // Only check for small enums.
16532 if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64)
16535 if (S.Diags.isIgnored(diag::warn_duplicate_enum_values, Enum->getLocation()))
16538 typedef SmallVector<EnumConstantDecl *, 3> ECDVector;
16539 typedef SmallVector<std::unique_ptr<ECDVector>, 3> DuplicatesVector;
16541 typedef llvm::PointerUnion<EnumConstantDecl*, ECDVector*> DeclOrVector;
16542 typedef std::unordered_map<int64_t, DeclOrVector> ValueToVectorMap;
16544 // Use int64_t as a key to avoid needing special handling for DenseMap keys.
16545 auto EnumConstantToKey = [](const EnumConstantDecl *D) {
16546 llvm::APSInt Val = D->getInitVal();
16547 return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue();
16550 DuplicatesVector DupVector;
16551 ValueToVectorMap EnumMap;
16553 // Populate the EnumMap with all values represented by enum constants without
16555 for (auto *Element : Elements) {
16556 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Element);
16558 // Null EnumConstantDecl means a previous diagnostic has been emitted for
16559 // this constant. Skip this enum since it may be ill-formed.
16564 // Constants with initalizers are handled in the next loop.
16565 if (ECD->getInitExpr())
16568 // Duplicate values are handled in the next loop.
16569 EnumMap.insert({EnumConstantToKey(ECD), ECD});
16572 if (EnumMap.size() == 0)
16575 // Create vectors for any values that has duplicates.
16576 for (auto *Element : Elements) {
16577 // The last loop returned if any constant was null.
16578 EnumConstantDecl *ECD = cast<EnumConstantDecl>(Element);
16579 if (!ValidDuplicateEnum(ECD, Enum))
16582 auto Iter = EnumMap.find(EnumConstantToKey(ECD));
16583 if (Iter == EnumMap.end())
16586 DeclOrVector& Entry = Iter->second;
16587 if (EnumConstantDecl *D = Entry.dyn_cast<EnumConstantDecl*>()) {
16588 // Ensure constants are different.
16592 // Create new vector and push values onto it.
16593 auto Vec = llvm::make_unique<ECDVector>();
16595 Vec->push_back(ECD);
16597 // Update entry to point to the duplicates vector.
16600 // Store the vector somewhere we can consult later for quick emission of
16602 DupVector.emplace_back(std::move(Vec));
16606 ECDVector *Vec = Entry.get<ECDVector*>();
16607 // Make sure constants are not added more than once.
16608 if (*Vec->begin() == ECD)
16611 Vec->push_back(ECD);
16614 // Emit diagnostics.
16615 for (const auto &Vec : DupVector) {
16616 assert(Vec->size() > 1 && "ECDVector should have at least 2 elements.");
16618 // Emit warning for one enum constant.
16619 auto *FirstECD = Vec->front();
16620 S.Diag(FirstECD->getLocation(), diag::warn_duplicate_enum_values)
16621 << FirstECD << FirstECD->getInitVal().toString(10)
16622 << FirstECD->getSourceRange();
16624 // Emit one note for each of the remaining enum constants with
16626 for (auto *ECD : llvm::make_range(Vec->begin() + 1, Vec->end()))
16627 S.Diag(ECD->getLocation(), diag::note_duplicate_element)
16628 << ECD << ECD->getInitVal().toString(10)
16629 << ECD->getSourceRange();
16633 bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
16634 bool AllowMask) const {
16635 assert(ED->isClosedFlag() && "looking for value in non-flag or open enum");
16636 assert(ED->isCompleteDefinition() && "expected enum definition");
16638 auto R = FlagBitsCache.insert(std::make_pair(ED, llvm::APInt()));
16639 llvm::APInt &FlagBits = R.first->second;
16642 for (auto *E : ED->enumerators()) {
16643 const auto &EVal = E->getInitVal();
16644 // Only single-bit enumerators introduce new flag values.
16645 if (EVal.isPowerOf2())
16646 FlagBits = FlagBits.zextOrSelf(EVal.getBitWidth()) | EVal;
16650 // A value is in a flag enum if either its bits are a subset of the enum's
16651 // flag bits (the first condition) or we are allowing masks and the same is
16652 // true of its complement (the second condition). When masks are allowed, we
16653 // allow the common idiom of ~(enum1 | enum2) to be a valid enum value.
16655 // While it's true that any value could be used as a mask, the assumption is
16656 // that a mask will have all of the insignificant bits set. Anything else is
16657 // likely a logic error.
16658 llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(Val.getBitWidth());
16659 return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
16662 void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
16663 Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S,
16664 const ParsedAttributesView &Attrs) {
16665 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX);
16666 QualType EnumType = Context.getTypeDeclType(Enum);
16668 ProcessDeclAttributeList(S, Enum, Attrs);
16670 if (Enum->isDependentType()) {
16671 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
16672 EnumConstantDecl *ECD =
16673 cast_or_null<EnumConstantDecl>(Elements[i]);
16674 if (!ECD) continue;
16676 ECD->setType(EnumType);
16679 Enum->completeDefinition(Context.DependentTy, Context.DependentTy, 0, 0);
16683 // TODO: If the result value doesn't fit in an int, it must be a long or long
16684 // long value. ISO C does not support this, but GCC does as an extension,
16686 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
16687 unsigned CharWidth = Context.getTargetInfo().getCharWidth();
16688 unsigned ShortWidth = Context.getTargetInfo().getShortWidth();
16690 // Verify that all the values are okay, compute the size of the values, and
16691 // reverse the list.
16692 unsigned NumNegativeBits = 0;
16693 unsigned NumPositiveBits = 0;
16695 // Keep track of whether all elements have type int.
16696 bool AllElementsInt = true;
16698 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
16699 EnumConstantDecl *ECD =
16700 cast_or_null<EnumConstantDecl>(Elements[i]);
16701 if (!ECD) continue; // Already issued a diagnostic.
16703 const llvm::APSInt &InitVal = ECD->getInitVal();
16705 // Keep track of the size of positive and negative values.
16706 if (InitVal.isUnsigned() || InitVal.isNonNegative())
16707 NumPositiveBits = std::max(NumPositiveBits,
16708 (unsigned)InitVal.getActiveBits());
16710 NumNegativeBits = std::max(NumNegativeBits,
16711 (unsigned)InitVal.getMinSignedBits());
16713 // Keep track of whether every enum element has type int (very common).
16714 if (AllElementsInt)
16715 AllElementsInt = ECD->getType() == Context.IntTy;
16718 // Figure out the type that should be used for this enum.
16720 unsigned BestWidth;
16722 // C++0x N3000 [conv.prom]p3:
16723 // An rvalue of an unscoped enumeration type whose underlying
16724 // type is not fixed can be converted to an rvalue of the first
16725 // of the following types that can represent all the values of
16726 // the enumeration: int, unsigned int, long int, unsigned long
16727 // int, long long int, or unsigned long long int.
16729 // An identifier declared as an enumeration constant has type int.
16730 // The C99 rule is modified by a gcc extension
16731 QualType BestPromotionType;
16733 bool Packed = Enum->hasAttr<PackedAttr>();
16734 // -fshort-enums is the equivalent to specifying the packed attribute on all
16735 // enum definitions.
16736 if (LangOpts.ShortEnums)
16739 // If the enum already has a type because it is fixed or dictated by the
16740 // target, promote that type instead of analyzing the enumerators.
16741 if (Enum->isComplete()) {
16742 BestType = Enum->getIntegerType();
16743 if (BestType->isPromotableIntegerType())
16744 BestPromotionType = Context.getPromotedIntegerType(BestType);
16746 BestPromotionType = BestType;
16748 BestWidth = Context.getIntWidth(BestType);
16750 else if (NumNegativeBits) {
16751 // If there is a negative value, figure out the smallest integer type (of
16752 // int/long/longlong) that fits.
16753 // If it's packed, check also if it fits a char or a short.
16754 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) {
16755 BestType = Context.SignedCharTy;
16756 BestWidth = CharWidth;
16757 } else if (Packed && NumNegativeBits <= ShortWidth &&
16758 NumPositiveBits < ShortWidth) {
16759 BestType = Context.ShortTy;
16760 BestWidth = ShortWidth;
16761 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
16762 BestType = Context.IntTy;
16763 BestWidth = IntWidth;
16765 BestWidth = Context.getTargetInfo().getLongWidth();
16767 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) {
16768 BestType = Context.LongTy;
16770 BestWidth = Context.getTargetInfo().getLongLongWidth();
16772 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
16773 Diag(Enum->getLocation(), diag::ext_enum_too_large);
16774 BestType = Context.LongLongTy;
16777 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
16779 // If there is no negative value, figure out the smallest type that fits
16780 // all of the enumerator values.
16781 // If it's packed, check also if it fits a char or a short.
16782 if (Packed && NumPositiveBits <= CharWidth) {
16783 BestType = Context.UnsignedCharTy;
16784 BestPromotionType = Context.IntTy;
16785 BestWidth = CharWidth;
16786 } else if (Packed && NumPositiveBits <= ShortWidth) {
16787 BestType = Context.UnsignedShortTy;
16788 BestPromotionType = Context.IntTy;
16789 BestWidth = ShortWidth;
16790 } else if (NumPositiveBits <= IntWidth) {
16791 BestType = Context.UnsignedIntTy;
16792 BestWidth = IntWidth;
16794 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16795 ? Context.UnsignedIntTy : Context.IntTy;
16796 } else if (NumPositiveBits <=
16797 (BestWidth = Context.getTargetInfo().getLongWidth())) {
16798 BestType = Context.UnsignedLongTy;
16800 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16801 ? Context.UnsignedLongTy : Context.LongTy;
16803 BestWidth = Context.getTargetInfo().getLongLongWidth();
16804 assert(NumPositiveBits <= BestWidth &&
16805 "How could an initializer get larger than ULL?");
16806 BestType = Context.UnsignedLongLongTy;
16808 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16809 ? Context.UnsignedLongLongTy : Context.LongLongTy;
16813 // Loop over all of the enumerator constants, changing their types to match
16814 // the type of the enum if needed.
16815 for (auto *D : Elements) {
16816 auto *ECD = cast_or_null<EnumConstantDecl>(D);
16817 if (!ECD) continue; // Already issued a diagnostic.
16819 // Standard C says the enumerators have int type, but we allow, as an
16820 // extension, the enumerators to be larger than int size. If each
16821 // enumerator value fits in an int, type it as an int, otherwise type it the
16822 // same as the enumerator decl itself. This means that in "enum { X = 1U }"
16823 // that X has type 'int', not 'unsigned'.
16825 // Determine whether the value fits into an int.
16826 llvm::APSInt InitVal = ECD->getInitVal();
16828 // If it fits into an integer type, force it. Otherwise force it to match
16829 // the enum decl type.
16833 if (!getLangOpts().CPlusPlus &&
16834 !Enum->isFixed() &&
16835 isRepresentableIntegerValue(Context, InitVal, Context.IntTy)) {
16836 NewTy = Context.IntTy;
16837 NewWidth = IntWidth;
16839 } else if (ECD->getType() == BestType) {
16840 // Already the right type!
16841 if (getLangOpts().CPlusPlus)
16842 // C++ [dcl.enum]p4: Following the closing brace of an
16843 // enum-specifier, each enumerator has the type of its
16845 ECD->setType(EnumType);
16849 NewWidth = BestWidth;
16850 NewSign = BestType->isSignedIntegerOrEnumerationType();
16853 // Adjust the APSInt value.
16854 InitVal = InitVal.extOrTrunc(NewWidth);
16855 InitVal.setIsSigned(NewSign);
16856 ECD->setInitVal(InitVal);
16858 // Adjust the Expr initializer and type.
16859 if (ECD->getInitExpr() &&
16860 !Context.hasSameType(NewTy, ECD->getInitExpr()->getType()))
16861 ECD->setInitExpr(ImplicitCastExpr::Create(Context, NewTy,
16863 ECD->getInitExpr(),
16864 /*base paths*/ nullptr,
16866 if (getLangOpts().CPlusPlus)
16867 // C++ [dcl.enum]p4: Following the closing brace of an
16868 // enum-specifier, each enumerator has the type of its
16870 ECD->setType(EnumType);
16872 ECD->setType(NewTy);
16875 Enum->completeDefinition(BestType, BestPromotionType,
16876 NumPositiveBits, NumNegativeBits);
16878 CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType);
16880 if (Enum->isClosedFlag()) {
16881 for (Decl *D : Elements) {
16882 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(D);
16883 if (!ECD) continue; // Already issued a diagnostic.
16885 llvm::APSInt InitVal = ECD->getInitVal();
16886 if (InitVal != 0 && !InitVal.isPowerOf2() &&
16887 !IsValueInFlagEnum(Enum, InitVal, true))
16888 Diag(ECD->getLocation(), diag::warn_flag_enum_constant_out_of_range)
16893 // Now that the enum type is defined, ensure it's not been underaligned.
16894 if (Enum->hasAttrs())
16895 CheckAlignasUnderalignment(Enum);
16898 Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr,
16899 SourceLocation StartLoc,
16900 SourceLocation EndLoc) {
16901 StringLiteral *AsmString = cast<StringLiteral>(expr);
16903 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext,
16904 AsmString, StartLoc,
16906 CurContext->addDecl(New);
16910 static void checkModuleImportContext(Sema &S, Module *M,
16911 SourceLocation ImportLoc, DeclContext *DC,
16912 bool FromInclude = false) {
16913 SourceLocation ExternCLoc;
16915 if (auto *LSD = dyn_cast<LinkageSpecDecl>(DC)) {
16916 switch (LSD->getLanguage()) {
16917 case LinkageSpecDecl::lang_c:
16918 if (ExternCLoc.isInvalid())
16919 ExternCLoc = LSD->getBeginLoc();
16921 case LinkageSpecDecl::lang_cxx:
16924 DC = LSD->getParent();
16927 while (isa<LinkageSpecDecl>(DC) || isa<ExportDecl>(DC))
16928 DC = DC->getParent();
16930 if (!isa<TranslationUnitDecl>(DC)) {
16931 S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M))
16932 ? diag::ext_module_import_not_at_top_level_noop
16933 : diag::err_module_import_not_at_top_level_fatal)
16934 << M->getFullModuleName() << DC;
16935 S.Diag(cast<Decl>(DC)->getBeginLoc(),
16936 diag::note_module_import_not_at_top_level)
16938 } else if (!M->IsExternC && ExternCLoc.isValid()) {
16939 S.Diag(ImportLoc, diag::ext_module_import_in_extern_c)
16940 << M->getFullModuleName();
16941 S.Diag(ExternCLoc, diag::note_extern_c_begins_here);
16945 Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc,
16946 SourceLocation ModuleLoc,
16947 ModuleDeclKind MDK,
16948 ModuleIdPath Path) {
16949 assert(getLangOpts().ModulesTS &&
16950 "should only have module decl in modules TS");
16952 // A module implementation unit requires that we are not compiling a module
16953 // of any kind. A module interface unit requires that we are not compiling a
16955 switch (getLangOpts().getCompilingModule()) {
16956 case LangOptions::CMK_None:
16957 // It's OK to compile a module interface as a normal translation unit.
16960 case LangOptions::CMK_ModuleInterface:
16961 if (MDK != ModuleDeclKind::Implementation)
16964 // We were asked to compile a module interface unit but this is a module
16965 // implementation unit. That indicates the 'export' is missing.
16966 Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch)
16967 << FixItHint::CreateInsertion(ModuleLoc, "export ");
16968 MDK = ModuleDeclKind::Interface;
16971 case LangOptions::CMK_ModuleMap:
16972 Diag(ModuleLoc, diag::err_module_decl_in_module_map_module);
16975 case LangOptions::CMK_HeaderModule:
16976 Diag(ModuleLoc, diag::err_module_decl_in_header_module);
16980 assert(ModuleScopes.size() == 1 && "expected to be at global module scope");
16982 // FIXME: Most of this work should be done by the preprocessor rather than
16983 // here, in order to support macro import.
16985 // Only one module-declaration is permitted per source file.
16986 if (ModuleScopes.back().Module->Kind == Module::ModuleInterfaceUnit) {
16987 Diag(ModuleLoc, diag::err_module_redeclaration);
16988 Diag(VisibleModules.getImportLoc(ModuleScopes.back().Module),
16989 diag::note_prev_module_declaration);
16993 // Flatten the dots in a module name. Unlike Clang's hierarchical module map
16994 // modules, the dots here are just another character that can appear in a
16996 std::string ModuleName;
16997 for (auto &Piece : Path) {
16998 if (!ModuleName.empty())
17000 ModuleName += Piece.first->getName();
17003 // If a module name was explicitly specified on the command line, it must be
17005 if (!getLangOpts().CurrentModule.empty() &&
17006 getLangOpts().CurrentModule != ModuleName) {
17007 Diag(Path.front().second, diag::err_current_module_name_mismatch)
17008 << SourceRange(Path.front().second, Path.back().second)
17009 << getLangOpts().CurrentModule;
17012 const_cast<LangOptions&>(getLangOpts()).CurrentModule = ModuleName;
17014 auto &Map = PP.getHeaderSearchInfo().getModuleMap();
17018 case ModuleDeclKind::Interface: {
17019 // We can't have parsed or imported a definition of this module or parsed a
17020 // module map defining it already.
17021 if (auto *M = Map.findModule(ModuleName)) {
17022 Diag(Path[0].second, diag::err_module_redefinition) << ModuleName;
17023 if (M->DefinitionLoc.isValid())
17024 Diag(M->DefinitionLoc, diag::note_prev_module_definition);
17025 else if (const auto *FE = M->getASTFile())
17026 Diag(M->DefinitionLoc, diag::note_prev_module_definition_from_ast_file)
17032 // Create a Module for the module that we're defining.
17033 Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName,
17034 ModuleScopes.front().Module);
17035 assert(Mod && "module creation should not fail");
17039 case ModuleDeclKind::Partition:
17040 // FIXME: Check we are in a submodule of the named module.
17043 case ModuleDeclKind::Implementation:
17044 std::pair<IdentifierInfo *, SourceLocation> ModuleNameLoc(
17045 PP.getIdentifierInfo(ModuleName), Path[0].second);
17046 Mod = getModuleLoader().loadModule(ModuleLoc, {ModuleNameLoc},
17047 Module::AllVisible,
17048 /*IsIncludeDirective=*/false);
17050 Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName;
17051 // Create an empty module interface unit for error recovery.
17052 Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName,
17053 ModuleScopes.front().Module);
17058 // Switch from the global module to the named module.
17059 ModuleScopes.back().Module = Mod;
17060 ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation;
17061 VisibleModules.setVisible(Mod, ModuleLoc);
17063 // From now on, we have an owning module for all declarations we see.
17064 // However, those declarations are module-private unless explicitly
17066 auto *TU = Context.getTranslationUnitDecl();
17067 TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate);
17068 TU->setLocalOwningModule(Mod);
17070 // FIXME: Create a ModuleDecl.
17074 DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc,
17075 SourceLocation ImportLoc,
17076 ModuleIdPath Path) {
17077 // Flatten the module path for a Modules TS module name.
17078 std::pair<IdentifierInfo *, SourceLocation> ModuleNameLoc;
17079 if (getLangOpts().ModulesTS) {
17080 std::string ModuleName;
17081 for (auto &Piece : Path) {
17082 if (!ModuleName.empty())
17084 ModuleName += Piece.first->getName();
17086 ModuleNameLoc = {PP.getIdentifierInfo(ModuleName), Path[0].second};
17087 Path = ModuleIdPath(ModuleNameLoc);
17091 getModuleLoader().loadModule(ImportLoc, Path, Module::AllVisible,
17092 /*IsIncludeDirective=*/false);
17096 VisibleModules.setVisible(Mod, ImportLoc);
17098 checkModuleImportContext(*this, Mod, ImportLoc, CurContext);
17100 // FIXME: we should support importing a submodule within a different submodule
17101 // of the same top-level module. Until we do, make it an error rather than
17102 // silently ignoring the import.
17103 // Import-from-implementation is valid in the Modules TS. FIXME: Should we
17104 // warn on a redundant import of the current module?
17105 if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule &&
17106 (getLangOpts().isCompilingModule() || !getLangOpts().ModulesTS))
17107 Diag(ImportLoc, getLangOpts().isCompilingModule()
17108 ? diag::err_module_self_import
17109 : diag::err_module_import_in_implementation)
17110 << Mod->getFullModuleName() << getLangOpts().CurrentModule;
17112 SmallVector<SourceLocation, 2> IdentifierLocs;
17113 Module *ModCheck = Mod;
17114 for (unsigned I = 0, N = Path.size(); I != N; ++I) {
17115 // If we've run out of module parents, just drop the remaining identifiers.
17116 // We need the length to be consistent.
17119 ModCheck = ModCheck->Parent;
17121 IdentifierLocs.push_back(Path[I].second);
17124 ImportDecl *Import = ImportDecl::Create(Context, CurContext, StartLoc,
17125 Mod, IdentifierLocs);
17126 if (!ModuleScopes.empty())
17127 Context.addModuleInitializer(ModuleScopes.back().Module, Import);
17128 CurContext->addDecl(Import);
17130 // Re-export the module if needed.
17131 if (Import->isExported() &&
17132 !ModuleScopes.empty() && ModuleScopes.back().ModuleInterface)
17133 getCurrentModule()->Exports.emplace_back(Mod, false);
17138 void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
17139 checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
17140 BuildModuleInclude(DirectiveLoc, Mod);
17143 void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
17144 // Determine whether we're in the #include buffer for a module. The #includes
17145 // in that buffer do not qualify as module imports; they're just an
17146 // implementation detail of us building the module.
17148 // FIXME: Should we even get ActOnModuleInclude calls for those?
17149 bool IsInModuleIncludes =
17150 TUKind == TU_Module &&
17151 getSourceManager().isWrittenInMainFile(DirectiveLoc);
17153 bool ShouldAddImport = !IsInModuleIncludes;
17155 // If this module import was due to an inclusion directive, create an
17156 // implicit import declaration to capture it in the AST.
17157 if (ShouldAddImport) {
17158 TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
17159 ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
17162 if (!ModuleScopes.empty())
17163 Context.addModuleInitializer(ModuleScopes.back().Module, ImportD);
17164 TU->addDecl(ImportD);
17165 Consumer.HandleImplicitImportDecl(ImportD);
17168 getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, DirectiveLoc);
17169 VisibleModules.setVisible(Mod, DirectiveLoc);
17172 void Sema::ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod) {
17173 checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
17175 ModuleScopes.push_back({});
17176 ModuleScopes.back().Module = Mod;
17177 if (getLangOpts().ModulesLocalVisibility)
17178 ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules);
17180 VisibleModules.setVisible(Mod, DirectiveLoc);
17182 // The enclosing context is now part of this module.
17183 // FIXME: Consider creating a child DeclContext to hold the entities
17184 // lexically within the module.
17185 if (getLangOpts().trackLocalOwningModule()) {
17186 for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) {
17187 cast<Decl>(DC)->setModuleOwnershipKind(
17188 getLangOpts().ModulesLocalVisibility
17189 ? Decl::ModuleOwnershipKind::VisibleWhenImported
17190 : Decl::ModuleOwnershipKind::Visible);
17191 cast<Decl>(DC)->setLocalOwningModule(Mod);
17196 void Sema::ActOnModuleEnd(SourceLocation EomLoc, Module *Mod) {
17197 if (getLangOpts().ModulesLocalVisibility) {
17198 VisibleModules = std::move(ModuleScopes.back().OuterVisibleModules);
17199 // Leaving a module hides namespace names, so our visible namespace cache
17200 // is now out of date.
17201 VisibleNamespaceCache.clear();
17204 assert(!ModuleScopes.empty() && ModuleScopes.back().Module == Mod &&
17205 "left the wrong module scope");
17206 ModuleScopes.pop_back();
17208 // We got to the end of processing a local module. Create an
17209 // ImportDecl as we would for an imported module.
17210 FileID File = getSourceManager().getFileID(EomLoc);
17211 SourceLocation DirectiveLoc;
17212 if (EomLoc == getSourceManager().getLocForEndOfFile(File)) {
17213 // We reached the end of a #included module header. Use the #include loc.
17214 assert(File != getSourceManager().getMainFileID() &&
17215 "end of submodule in main source file");
17216 DirectiveLoc = getSourceManager().getIncludeLoc(File);
17218 // We reached an EOM pragma. Use the pragma location.
17219 DirectiveLoc = EomLoc;
17221 BuildModuleInclude(DirectiveLoc, Mod);
17223 // Any further declarations are in whatever module we returned to.
17224 if (getLangOpts().trackLocalOwningModule()) {
17225 // The parser guarantees that this is the same context that we entered
17226 // the module within.
17227 for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) {
17228 cast<Decl>(DC)->setLocalOwningModule(getCurrentModule());
17229 if (!getCurrentModule())
17230 cast<Decl>(DC)->setModuleOwnershipKind(
17231 Decl::ModuleOwnershipKind::Unowned);
17236 void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
17238 // Bail if we're not allowed to implicitly import a module here.
17239 if (isSFINAEContext() || !getLangOpts().ModulesErrorRecovery ||
17240 VisibleModules.isVisible(Mod))
17243 // Create the implicit import declaration.
17244 TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
17245 ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
17247 TU->addDecl(ImportD);
17248 Consumer.HandleImplicitImportDecl(ImportD);
17250 // Make the module visible.
17251 getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, Loc);
17252 VisibleModules.setVisible(Mod, Loc);
17255 /// We have parsed the start of an export declaration, including the '{'
17257 Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
17258 SourceLocation LBraceLoc) {
17259 ExportDecl *D = ExportDecl::Create(Context, CurContext, ExportLoc);
17261 // C++ Modules TS draft:
17262 // An export-declaration shall appear in the purview of a module other than
17263 // the global module.
17264 if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface)
17265 Diag(ExportLoc, diag::err_export_not_in_module_interface);
17267 // An export-declaration [...] shall not contain more than one
17270 // The intent here is that an export-declaration cannot appear within another
17271 // export-declaration.
17272 if (D->isExported())
17273 Diag(ExportLoc, diag::err_export_within_export);
17275 CurContext->addDecl(D);
17276 PushDeclContext(S, D);
17277 D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
17281 /// Complete the definition of an export declaration.
17282 Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) {
17283 auto *ED = cast<ExportDecl>(D);
17284 if (RBraceLoc.isValid())
17285 ED->setRBraceLoc(RBraceLoc);
17287 // FIXME: Diagnose export of internal-linkage declaration (including
17288 // anonymous namespace).
17294 void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
17295 IdentifierInfo* AliasName,
17296 SourceLocation PragmaLoc,
17297 SourceLocation NameLoc,
17298 SourceLocation AliasNameLoc) {
17299 NamedDecl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc,
17300 LookupOrdinaryName);
17301 AsmLabelAttr *Attr =
17302 AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), AliasNameLoc);
17304 // If a declaration that:
17305 // 1) declares a function or a variable
17306 // 2) has external linkage
17307 // already exists, add a label attribute to it.
17308 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
17309 if (isDeclExternC(PrevDecl))
17310 PrevDecl->addAttr(Attr);
17312 Diag(PrevDecl->getLocation(), diag::warn_redefine_extname_not_applied)
17313 << /*Variable*/(isa<FunctionDecl>(PrevDecl) ? 0 : 1) << PrevDecl;
17314 // Otherwise, add a label atttibute to ExtnameUndeclaredIdentifiers.
17316 (void)ExtnameUndeclaredIdentifiers.insert(std::make_pair(Name, Attr));
17319 void Sema::ActOnPragmaWeakID(IdentifierInfo* Name,
17320 SourceLocation PragmaLoc,
17321 SourceLocation NameLoc) {
17322 Decl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, LookupOrdinaryName);
17325 PrevDecl->addAttr(WeakAttr::CreateImplicit(Context, PragmaLoc));
17327 (void)WeakUndeclaredIdentifiers.insert(
17328 std::pair<IdentifierInfo*,WeakInfo>
17329 (Name, WeakInfo((IdentifierInfo*)nullptr, NameLoc)));
17333 void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name,
17334 IdentifierInfo* AliasName,
17335 SourceLocation PragmaLoc,
17336 SourceLocation NameLoc,
17337 SourceLocation AliasNameLoc) {
17338 Decl *PrevDecl = LookupSingleName(TUScope, AliasName, AliasNameLoc,
17339 LookupOrdinaryName);
17340 WeakInfo W = WeakInfo(Name, NameLoc);
17342 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
17343 if (!PrevDecl->hasAttr<AliasAttr>())
17344 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl))
17345 DeclApplyPragmaWeak(TUScope, ND, W);
17347 (void)WeakUndeclaredIdentifiers.insert(
17348 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W));
17352 Decl *Sema::getObjCDeclContext() const {
17353 return (dyn_cast_or_null<ObjCContainerDecl>(CurContext));