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(D->getLocEnd(),
1739 tok::colon, Ctx.getSourceManager(), Ctx.getLangOpts(), true);
1740 if (AfterColon.isInvalid())
1742 Hint = FixItHint::CreateRemoval(CharSourceRange::
1743 getCharRange(D->getLocStart(), AfterColon));
1747 void Sema::DiagnoseUnusedNestedTypedefs(const RecordDecl *D) {
1748 if (D->getTypeForDecl()->isDependentType())
1751 for (auto *TmpD : D->decls()) {
1752 if (const auto *T = dyn_cast<TypedefNameDecl>(TmpD))
1753 DiagnoseUnusedDecl(T);
1754 else if(const auto *R = dyn_cast<RecordDecl>(TmpD))
1755 DiagnoseUnusedNestedTypedefs(R);
1759 /// DiagnoseUnusedDecl - Emit warnings about declarations that are not used
1760 /// unless they are marked attr(unused).
1761 void Sema::DiagnoseUnusedDecl(const NamedDecl *D) {
1762 if (!ShouldDiagnoseUnusedDecl(D))
1765 if (auto *TD = dyn_cast<TypedefNameDecl>(D)) {
1766 // typedefs can be referenced later on, so the diagnostics are emitted
1767 // at end-of-translation-unit.
1768 UnusedLocalTypedefNameCandidates.insert(TD);
1773 GenerateFixForUnusedDecl(D, Context, Hint);
1776 if (isa<VarDecl>(D) && cast<VarDecl>(D)->isExceptionVariable())
1777 DiagID = diag::warn_unused_exception_param;
1778 else if (isa<LabelDecl>(D))
1779 DiagID = diag::warn_unused_label;
1781 DiagID = diag::warn_unused_variable;
1783 Diag(D->getLocation(), DiagID) << D << Hint;
1786 static void CheckPoppedLabel(LabelDecl *L, Sema &S) {
1787 // Verify that we have no forward references left. If so, there was a goto
1788 // or address of a label taken, but no definition of it. Label fwd
1789 // definitions are indicated with a null substmt which is also not a resolved
1790 // MS inline assembly label name.
1791 bool Diagnose = false;
1792 if (L->isMSAsmLabel())
1793 Diagnose = !L->isResolvedMSAsmLabel();
1795 Diagnose = L->getStmt() == nullptr;
1797 S.Diag(L->getLocation(), diag::err_undeclared_label_use) <<L->getDeclName();
1800 void Sema::ActOnPopScope(SourceLocation Loc, Scope *S) {
1801 S->mergeNRVOIntoParent();
1803 if (S->decl_empty()) return;
1804 assert((S->getFlags() & (Scope::DeclScope | Scope::TemplateParamScope)) &&
1805 "Scope shouldn't contain decls!");
1807 for (auto *TmpD : S->decls()) {
1808 assert(TmpD && "This decl didn't get pushed??");
1810 assert(isa<NamedDecl>(TmpD) && "Decl isn't NamedDecl?");
1811 NamedDecl *D = cast<NamedDecl>(TmpD);
1813 // Diagnose unused variables in this scope.
1814 if (!S->hasUnrecoverableErrorOccurred()) {
1815 DiagnoseUnusedDecl(D);
1816 if (const auto *RD = dyn_cast<RecordDecl>(D))
1817 DiagnoseUnusedNestedTypedefs(RD);
1820 if (!D->getDeclName()) continue;
1822 // If this was a forward reference to a label, verify it was defined.
1823 if (LabelDecl *LD = dyn_cast<LabelDecl>(D))
1824 CheckPoppedLabel(LD, *this);
1826 // Remove this name from our lexical scope, and warn on it if we haven't
1828 IdResolver.RemoveDecl(D);
1829 auto ShadowI = ShadowingDecls.find(D);
1830 if (ShadowI != ShadowingDecls.end()) {
1831 if (const auto *FD = dyn_cast<FieldDecl>(ShadowI->second)) {
1832 Diag(D->getLocation(), diag::warn_ctor_parm_shadows_field)
1833 << D << FD << FD->getParent();
1834 Diag(FD->getLocation(), diag::note_previous_declaration);
1836 ShadowingDecls.erase(ShadowI);
1841 /// Look for an Objective-C class in the translation unit.
1843 /// \param Id The name of the Objective-C class we're looking for. If
1844 /// typo-correction fixes this name, the Id will be updated
1845 /// to the fixed name.
1847 /// \param IdLoc The location of the name in the translation unit.
1849 /// \param DoTypoCorrection If true, this routine will attempt typo correction
1850 /// if there is no class with the given name.
1852 /// \returns The declaration of the named Objective-C class, or NULL if the
1853 /// class could not be found.
1854 ObjCInterfaceDecl *Sema::getObjCInterfaceDecl(IdentifierInfo *&Id,
1855 SourceLocation IdLoc,
1856 bool DoTypoCorrection) {
1857 // The third "scope" argument is 0 since we aren't enabling lazy built-in
1858 // creation from this context.
1859 NamedDecl *IDecl = LookupSingleName(TUScope, Id, IdLoc, LookupOrdinaryName);
1861 if (!IDecl && DoTypoCorrection) {
1862 // Perform typo correction at the given location, but only if we
1863 // find an Objective-C class name.
1864 if (TypoCorrection C = CorrectTypo(
1865 DeclarationNameInfo(Id, IdLoc), LookupOrdinaryName, TUScope, nullptr,
1866 llvm::make_unique<DeclFilterCCC<ObjCInterfaceDecl>>(),
1867 CTK_ErrorRecovery)) {
1868 diagnoseTypo(C, PDiag(diag::err_undef_interface_suggest) << Id);
1869 IDecl = C.getCorrectionDeclAs<ObjCInterfaceDecl>();
1870 Id = IDecl->getIdentifier();
1873 ObjCInterfaceDecl *Def = dyn_cast_or_null<ObjCInterfaceDecl>(IDecl);
1874 // This routine must always return a class definition, if any.
1875 if (Def && Def->getDefinition())
1876 Def = Def->getDefinition();
1880 /// getNonFieldDeclScope - Retrieves the innermost scope, starting
1881 /// from S, where a non-field would be declared. This routine copes
1882 /// with the difference between C and C++ scoping rules in structs and
1883 /// unions. For example, the following code is well-formed in C but
1884 /// ill-formed in C++:
1890 /// void test_S6() {
1895 /// For the declaration of BAR, this routine will return a different
1896 /// scope. The scope S will be the scope of the unnamed enumeration
1897 /// within S6. In C++, this routine will return the scope associated
1898 /// with S6, because the enumeration's scope is a transparent
1899 /// context but structures can contain non-field names. In C, this
1900 /// routine will return the translation unit scope, since the
1901 /// enumeration's scope is a transparent context and structures cannot
1902 /// contain non-field names.
1903 Scope *Sema::getNonFieldDeclScope(Scope *S) {
1904 while (((S->getFlags() & Scope::DeclScope) == 0) ||
1905 (S->getEntity() && S->getEntity()->isTransparentContext()) ||
1906 (S->isClassScope() && !getLangOpts().CPlusPlus))
1911 /// Looks up the declaration of "struct objc_super" and
1912 /// saves it for later use in building builtin declaration of
1913 /// objc_msgSendSuper and objc_msgSendSuper_stret. If no such
1914 /// pre-existing declaration exists no action takes place.
1915 static void LookupPredefedObjCSuperType(Sema &ThisSema, Scope *S,
1916 IdentifierInfo *II) {
1917 if (!II->isStr("objc_msgSendSuper"))
1919 ASTContext &Context = ThisSema.Context;
1921 LookupResult Result(ThisSema, &Context.Idents.get("objc_super"),
1922 SourceLocation(), Sema::LookupTagName);
1923 ThisSema.LookupName(Result, S);
1924 if (Result.getResultKind() == LookupResult::Found)
1925 if (const TagDecl *TD = Result.getAsSingle<TagDecl>())
1926 Context.setObjCSuperType(Context.getTagDeclType(TD));
1929 static StringRef getHeaderName(ASTContext::GetBuiltinTypeError Error) {
1931 case ASTContext::GE_None:
1933 case ASTContext::GE_Missing_stdio:
1935 case ASTContext::GE_Missing_setjmp:
1937 case ASTContext::GE_Missing_ucontext:
1938 return "ucontext.h";
1940 llvm_unreachable("unhandled error kind");
1943 /// LazilyCreateBuiltin - The specified Builtin-ID was first used at
1944 /// file scope. lazily create a decl for it. ForRedeclaration is true
1945 /// if we're creating this built-in in anticipation of redeclaring the
1947 NamedDecl *Sema::LazilyCreateBuiltin(IdentifierInfo *II, unsigned ID,
1948 Scope *S, bool ForRedeclaration,
1949 SourceLocation Loc) {
1950 LookupPredefedObjCSuperType(*this, S, II);
1952 ASTContext::GetBuiltinTypeError Error;
1953 QualType R = Context.GetBuiltinType(ID, Error);
1955 if (ForRedeclaration)
1956 Diag(Loc, diag::warn_implicit_decl_requires_sysheader)
1957 << getHeaderName(Error) << Context.BuiltinInfo.getName(ID);
1961 if (!ForRedeclaration &&
1962 (Context.BuiltinInfo.isPredefinedLibFunction(ID) ||
1963 Context.BuiltinInfo.isHeaderDependentFunction(ID))) {
1964 Diag(Loc, diag::ext_implicit_lib_function_decl)
1965 << Context.BuiltinInfo.getName(ID) << R;
1966 if (Context.BuiltinInfo.getHeaderName(ID) &&
1967 !Diags.isIgnored(diag::ext_implicit_lib_function_decl, Loc))
1968 Diag(Loc, diag::note_include_header_or_declare)
1969 << Context.BuiltinInfo.getHeaderName(ID)
1970 << Context.BuiltinInfo.getName(ID);
1976 DeclContext *Parent = Context.getTranslationUnitDecl();
1977 if (getLangOpts().CPlusPlus) {
1978 LinkageSpecDecl *CLinkageDecl =
1979 LinkageSpecDecl::Create(Context, Parent, Loc, Loc,
1980 LinkageSpecDecl::lang_c, false);
1981 CLinkageDecl->setImplicit();
1982 Parent->addDecl(CLinkageDecl);
1983 Parent = CLinkageDecl;
1986 FunctionDecl *New = FunctionDecl::Create(Context,
1988 Loc, Loc, II, R, /*TInfo=*/nullptr,
1991 R->isFunctionProtoType());
1994 // Create Decl objects for each parameter, adding them to the
1996 if (const FunctionProtoType *FT = dyn_cast<FunctionProtoType>(R)) {
1997 SmallVector<ParmVarDecl*, 16> Params;
1998 for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
2000 ParmVarDecl::Create(Context, New, SourceLocation(), SourceLocation(),
2001 nullptr, FT->getParamType(i), /*TInfo=*/nullptr,
2003 parm->setScopeInfo(0, i);
2004 Params.push_back(parm);
2006 New->setParams(Params);
2009 AddKnownFunctionAttributes(New);
2010 RegisterLocallyScopedExternCDecl(New, S);
2012 // TUScope is the translation-unit scope to insert this function into.
2013 // FIXME: This is hideous. We need to teach PushOnScopeChains to
2014 // relate Scopes to DeclContexts, and probably eliminate CurContext
2015 // entirely, but we're not there yet.
2016 DeclContext *SavedContext = CurContext;
2017 CurContext = Parent;
2018 PushOnScopeChains(New, TUScope);
2019 CurContext = SavedContext;
2023 /// Typedef declarations don't have linkage, but they still denote the same
2024 /// entity if their types are the same.
2025 /// FIXME: This is notionally doing the same thing as ASTReaderDecl's
2027 static void filterNonConflictingPreviousTypedefDecls(Sema &S,
2028 TypedefNameDecl *Decl,
2029 LookupResult &Previous) {
2030 // This is only interesting when modules are enabled.
2031 if (!S.getLangOpts().Modules && !S.getLangOpts().ModulesLocalVisibility)
2034 // Empty sets are uninteresting.
2035 if (Previous.empty())
2038 LookupResult::Filter Filter = Previous.makeFilter();
2039 while (Filter.hasNext()) {
2040 NamedDecl *Old = Filter.next();
2042 // Non-hidden declarations are never ignored.
2043 if (S.isVisible(Old))
2046 // Declarations of the same entity are not ignored, even if they have
2047 // different linkages.
2048 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2049 if (S.Context.hasSameType(OldTD->getUnderlyingType(),
2050 Decl->getUnderlyingType()))
2053 // If both declarations give a tag declaration a typedef name for linkage
2054 // purposes, then they declare the same entity.
2055 if (OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true) &&
2056 Decl->getAnonDeclWithTypedefName())
2066 bool Sema::isIncompatibleTypedef(TypeDecl *Old, TypedefNameDecl *New) {
2068 if (TypedefNameDecl *OldTypedef = dyn_cast<TypedefNameDecl>(Old))
2069 OldType = OldTypedef->getUnderlyingType();
2071 OldType = Context.getTypeDeclType(Old);
2072 QualType NewType = New->getUnderlyingType();
2074 if (NewType->isVariablyModifiedType()) {
2075 // Must not redefine a typedef with a variably-modified type.
2076 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2077 Diag(New->getLocation(), diag::err_redefinition_variably_modified_typedef)
2079 if (Old->getLocation().isValid())
2080 notePreviousDefinition(Old, New->getLocation());
2081 New->setInvalidDecl();
2085 if (OldType != NewType &&
2086 !OldType->isDependentType() &&
2087 !NewType->isDependentType() &&
2088 !Context.hasSameType(OldType, NewType)) {
2089 int Kind = isa<TypeAliasDecl>(Old) ? 1 : 0;
2090 Diag(New->getLocation(), diag::err_redefinition_different_typedef)
2091 << Kind << NewType << OldType;
2092 if (Old->getLocation().isValid())
2093 notePreviousDefinition(Old, New->getLocation());
2094 New->setInvalidDecl();
2100 /// MergeTypedefNameDecl - We just parsed a typedef 'New' which has the
2101 /// same name and scope as a previous declaration 'Old'. Figure out
2102 /// how to resolve this situation, merging decls or emitting
2103 /// diagnostics as appropriate. If there was an error, set New to be invalid.
2105 void Sema::MergeTypedefNameDecl(Scope *S, TypedefNameDecl *New,
2106 LookupResult &OldDecls) {
2107 // If the new decl is known invalid already, don't bother doing any
2109 if (New->isInvalidDecl()) return;
2111 // Allow multiple definitions for ObjC built-in typedefs.
2112 // FIXME: Verify the underlying types are equivalent!
2113 if (getLangOpts().ObjC1) {
2114 const IdentifierInfo *TypeID = New->getIdentifier();
2115 switch (TypeID->getLength()) {
2119 if (!TypeID->isStr("id"))
2121 QualType T = New->getUnderlyingType();
2122 if (!T->isPointerType())
2124 if (!T->isVoidPointerType()) {
2125 QualType PT = T->getAs<PointerType>()->getPointeeType();
2126 if (!PT->isStructureType())
2129 Context.setObjCIdRedefinitionType(T);
2130 // Install the built-in type for 'id', ignoring the current definition.
2131 New->setTypeForDecl(Context.getObjCIdType().getTypePtr());
2135 if (!TypeID->isStr("Class"))
2137 Context.setObjCClassRedefinitionType(New->getUnderlyingType());
2138 // Install the built-in type for 'Class', ignoring the current definition.
2139 New->setTypeForDecl(Context.getObjCClassType().getTypePtr());
2142 if (!TypeID->isStr("SEL"))
2144 Context.setObjCSelRedefinitionType(New->getUnderlyingType());
2145 // Install the built-in type for 'SEL', ignoring the current definition.
2146 New->setTypeForDecl(Context.getObjCSelType().getTypePtr());
2149 // Fall through - the typedef name was not a builtin type.
2152 // Verify the old decl was also a type.
2153 TypeDecl *Old = OldDecls.getAsSingle<TypeDecl>();
2155 Diag(New->getLocation(), diag::err_redefinition_different_kind)
2156 << New->getDeclName();
2158 NamedDecl *OldD = OldDecls.getRepresentativeDecl();
2159 if (OldD->getLocation().isValid())
2160 notePreviousDefinition(OldD, New->getLocation());
2162 return New->setInvalidDecl();
2165 // If the old declaration is invalid, just give up here.
2166 if (Old->isInvalidDecl())
2167 return New->setInvalidDecl();
2169 if (auto *OldTD = dyn_cast<TypedefNameDecl>(Old)) {
2170 auto *OldTag = OldTD->getAnonDeclWithTypedefName(/*AnyRedecl*/true);
2171 auto *NewTag = New->getAnonDeclWithTypedefName();
2172 NamedDecl *Hidden = nullptr;
2173 if (OldTag && NewTag &&
2174 OldTag->getCanonicalDecl() != NewTag->getCanonicalDecl() &&
2175 !hasVisibleDefinition(OldTag, &Hidden)) {
2176 // There is a definition of this tag, but it is not visible. Use it
2177 // instead of our tag.
2178 New->setTypeForDecl(OldTD->getTypeForDecl());
2179 if (OldTD->isModed())
2180 New->setModedTypeSourceInfo(OldTD->getTypeSourceInfo(),
2181 OldTD->getUnderlyingType());
2183 New->setTypeSourceInfo(OldTD->getTypeSourceInfo());
2185 // Make the old tag definition visible.
2186 makeMergedDefinitionVisible(Hidden);
2188 // If this was an unscoped enumeration, yank all of its enumerators
2189 // out of the scope.
2190 if (isa<EnumDecl>(NewTag)) {
2191 Scope *EnumScope = getNonFieldDeclScope(S);
2192 for (auto *D : NewTag->decls()) {
2193 auto *ED = cast<EnumConstantDecl>(D);
2194 assert(EnumScope->isDeclScope(ED));
2195 EnumScope->RemoveDecl(ED);
2196 IdResolver.RemoveDecl(ED);
2197 ED->getLexicalDeclContext()->removeDecl(ED);
2203 // If the typedef types are not identical, reject them in all languages and
2204 // with any extensions enabled.
2205 if (isIncompatibleTypedef(Old, New))
2208 // The types match. Link up the redeclaration chain and merge attributes if
2209 // the old declaration was a typedef.
2210 if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old)) {
2211 New->setPreviousDecl(Typedef);
2212 mergeDeclAttributes(New, Old);
2215 if (getLangOpts().MicrosoftExt)
2218 if (getLangOpts().CPlusPlus) {
2219 // C++ [dcl.typedef]p2:
2220 // In a given non-class scope, a typedef specifier can be used to
2221 // redefine the name of any type declared in that scope to refer
2222 // to the type to which it already refers.
2223 if (!isa<CXXRecordDecl>(CurContext))
2226 // C++0x [dcl.typedef]p4:
2227 // In a given class scope, a typedef specifier can be used to redefine
2228 // any class-name declared in that scope that is not also a typedef-name
2229 // to refer to the type to which it already refers.
2231 // This wording came in via DR424, which was a correction to the
2232 // wording in DR56, which accidentally banned code like:
2235 // typedef struct A { } A;
2238 // in the C++03 standard. We implement the C++0x semantics, which
2239 // allow the above but disallow
2246 // since that was the intent of DR56.
2247 if (!isa<TypedefNameDecl>(Old))
2250 Diag(New->getLocation(), diag::err_redefinition)
2251 << New->getDeclName();
2252 notePreviousDefinition(Old, New->getLocation());
2253 return New->setInvalidDecl();
2256 // Modules always permit redefinition of typedefs, as does C11.
2257 if (getLangOpts().Modules || getLangOpts().C11)
2260 // If we have a redefinition of a typedef in C, emit a warning. This warning
2261 // is normally mapped to an error, but can be controlled with
2262 // -Wtypedef-redefinition. If either the original or the redefinition is
2263 // in a system header, don't emit this for compatibility with GCC.
2264 if (getDiagnostics().getSuppressSystemWarnings() &&
2265 // Some standard types are defined implicitly in Clang (e.g. OpenCL).
2266 (Old->isImplicit() ||
2267 Context.getSourceManager().isInSystemHeader(Old->getLocation()) ||
2268 Context.getSourceManager().isInSystemHeader(New->getLocation())))
2271 Diag(New->getLocation(), diag::ext_redefinition_of_typedef)
2272 << New->getDeclName();
2273 notePreviousDefinition(Old, New->getLocation());
2276 /// DeclhasAttr - returns true if decl Declaration already has the target
2278 static bool DeclHasAttr(const Decl *D, const Attr *A) {
2279 const OwnershipAttr *OA = dyn_cast<OwnershipAttr>(A);
2280 const AnnotateAttr *Ann = dyn_cast<AnnotateAttr>(A);
2281 for (const auto *i : D->attrs())
2282 if (i->getKind() == A->getKind()) {
2284 if (Ann->getAnnotation() == cast<AnnotateAttr>(i)->getAnnotation())
2288 // FIXME: Don't hardcode this check
2289 if (OA && isa<OwnershipAttr>(i))
2290 return OA->getOwnKind() == cast<OwnershipAttr>(i)->getOwnKind();
2297 static bool isAttributeTargetADefinition(Decl *D) {
2298 if (VarDecl *VD = dyn_cast<VarDecl>(D))
2299 return VD->isThisDeclarationADefinition();
2300 if (TagDecl *TD = dyn_cast<TagDecl>(D))
2301 return TD->isCompleteDefinition() || TD->isBeingDefined();
2305 /// Merge alignment attributes from \p Old to \p New, taking into account the
2306 /// special semantics of C11's _Alignas specifier and C++11's alignas attribute.
2308 /// \return \c true if any attributes were added to \p New.
2309 static bool mergeAlignedAttrs(Sema &S, NamedDecl *New, Decl *Old) {
2310 // Look for alignas attributes on Old, and pick out whichever attribute
2311 // specifies the strictest alignment requirement.
2312 AlignedAttr *OldAlignasAttr = nullptr;
2313 AlignedAttr *OldStrictestAlignAttr = nullptr;
2314 unsigned OldAlign = 0;
2315 for (auto *I : Old->specific_attrs<AlignedAttr>()) {
2316 // FIXME: We have no way of representing inherited dependent alignments
2318 // template<int A, int B> struct alignas(A) X;
2319 // template<int A, int B> struct alignas(B) X {};
2320 // For now, we just ignore any alignas attributes which are not on the
2321 // definition in such a case.
2322 if (I->isAlignmentDependent())
2328 unsigned Align = I->getAlignment(S.Context);
2329 if (Align > OldAlign) {
2331 OldStrictestAlignAttr = I;
2335 // Look for alignas attributes on New.
2336 AlignedAttr *NewAlignasAttr = nullptr;
2337 unsigned NewAlign = 0;
2338 for (auto *I : New->specific_attrs<AlignedAttr>()) {
2339 if (I->isAlignmentDependent())
2345 unsigned Align = I->getAlignment(S.Context);
2346 if (Align > NewAlign)
2350 if (OldAlignasAttr && NewAlignasAttr && OldAlign != NewAlign) {
2351 // Both declarations have 'alignas' attributes. We require them to match.
2352 // C++11 [dcl.align]p6 and C11 6.7.5/7 both come close to saying this, but
2353 // fall short. (If two declarations both have alignas, they must both match
2354 // every definition, and so must match each other if there is a definition.)
2356 // If either declaration only contains 'alignas(0)' specifiers, then it
2357 // specifies the natural alignment for the type.
2358 if (OldAlign == 0 || NewAlign == 0) {
2360 if (ValueDecl *VD = dyn_cast<ValueDecl>(New))
2363 Ty = S.Context.getTagDeclType(cast<TagDecl>(New));
2366 OldAlign = S.Context.getTypeAlign(Ty);
2368 NewAlign = S.Context.getTypeAlign(Ty);
2371 if (OldAlign != NewAlign) {
2372 S.Diag(NewAlignasAttr->getLocation(), diag::err_alignas_mismatch)
2373 << (unsigned)S.Context.toCharUnitsFromBits(OldAlign).getQuantity()
2374 << (unsigned)S.Context.toCharUnitsFromBits(NewAlign).getQuantity();
2375 S.Diag(OldAlignasAttr->getLocation(), diag::note_previous_declaration);
2379 if (OldAlignasAttr && !NewAlignasAttr && isAttributeTargetADefinition(New)) {
2380 // C++11 [dcl.align]p6:
2381 // if any declaration of an entity has an alignment-specifier,
2382 // every defining declaration of that entity shall specify an
2383 // equivalent alignment.
2385 // If the definition of an object does not have an alignment
2386 // specifier, any other declaration of that object shall also
2387 // have no alignment specifier.
2388 S.Diag(New->getLocation(), diag::err_alignas_missing_on_definition)
2390 S.Diag(OldAlignasAttr->getLocation(), diag::note_alignas_on_declaration)
2394 bool AnyAdded = false;
2396 // Ensure we have an attribute representing the strictest alignment.
2397 if (OldAlign > NewAlign) {
2398 AlignedAttr *Clone = OldStrictestAlignAttr->clone(S.Context);
2399 Clone->setInherited(true);
2400 New->addAttr(Clone);
2404 // Ensure we have an alignas attribute if the old declaration had one.
2405 if (OldAlignasAttr && !NewAlignasAttr &&
2406 !(AnyAdded && OldStrictestAlignAttr->isAlignas())) {
2407 AlignedAttr *Clone = OldAlignasAttr->clone(S.Context);
2408 Clone->setInherited(true);
2409 New->addAttr(Clone);
2416 static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
2417 const InheritableAttr *Attr,
2418 Sema::AvailabilityMergeKind AMK) {
2419 // This function copies an attribute Attr from a previous declaration to the
2420 // new declaration D if the new declaration doesn't itself have that attribute
2421 // yet or if that attribute allows duplicates.
2422 // If you're adding a new attribute that requires logic different from
2423 // "use explicit attribute on decl if present, else use attribute from
2424 // previous decl", for example if the attribute needs to be consistent
2425 // between redeclarations, you need to call a custom merge function here.
2426 InheritableAttr *NewAttr = nullptr;
2427 unsigned AttrSpellingListIndex = Attr->getSpellingListIndex();
2428 if (const auto *AA = dyn_cast<AvailabilityAttr>(Attr))
2429 NewAttr = S.mergeAvailabilityAttr(D, AA->getRange(), AA->getPlatform(),
2430 AA->isImplicit(), AA->getIntroduced(),
2431 AA->getDeprecated(),
2432 AA->getObsoleted(), AA->getUnavailable(),
2433 AA->getMessage(), AA->getStrict(),
2434 AA->getReplacement(), AMK,
2435 AttrSpellingListIndex);
2436 else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
2437 NewAttr = S.mergeVisibilityAttr(D, VA->getRange(), VA->getVisibility(),
2438 AttrSpellingListIndex);
2439 else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
2440 NewAttr = S.mergeTypeVisibilityAttr(D, VA->getRange(), VA->getVisibility(),
2441 AttrSpellingListIndex);
2442 else if (const auto *ImportA = dyn_cast<DLLImportAttr>(Attr))
2443 NewAttr = S.mergeDLLImportAttr(D, ImportA->getRange(),
2444 AttrSpellingListIndex);
2445 else if (const auto *ExportA = dyn_cast<DLLExportAttr>(Attr))
2446 NewAttr = S.mergeDLLExportAttr(D, ExportA->getRange(),
2447 AttrSpellingListIndex);
2448 else if (const auto *FA = dyn_cast<FormatAttr>(Attr))
2449 NewAttr = S.mergeFormatAttr(D, FA->getRange(), FA->getType(),
2450 FA->getFormatIdx(), FA->getFirstArg(),
2451 AttrSpellingListIndex);
2452 else if (const auto *SA = dyn_cast<SectionAttr>(Attr))
2453 NewAttr = S.mergeSectionAttr(D, SA->getRange(), SA->getName(),
2454 AttrSpellingListIndex);
2455 else if (const auto *CSA = dyn_cast<CodeSegAttr>(Attr))
2456 NewAttr = S.mergeCodeSegAttr(D, CSA->getRange(), CSA->getName(),
2457 AttrSpellingListIndex);
2458 else if (const auto *IA = dyn_cast<MSInheritanceAttr>(Attr))
2459 NewAttr = S.mergeMSInheritanceAttr(D, IA->getRange(), IA->getBestCase(),
2460 AttrSpellingListIndex,
2461 IA->getSemanticSpelling());
2462 else if (const auto *AA = dyn_cast<AlwaysInlineAttr>(Attr))
2463 NewAttr = S.mergeAlwaysInlineAttr(D, AA->getRange(),
2464 &S.Context.Idents.get(AA->getSpelling()),
2465 AttrSpellingListIndex);
2466 else if (S.getLangOpts().CUDA && isa<FunctionDecl>(D) &&
2467 (isa<CUDAHostAttr>(Attr) || isa<CUDADeviceAttr>(Attr) ||
2468 isa<CUDAGlobalAttr>(Attr))) {
2469 // CUDA target attributes are part of function signature for
2470 // overloading purposes and must not be merged.
2472 } else if (const auto *MA = dyn_cast<MinSizeAttr>(Attr))
2473 NewAttr = S.mergeMinSizeAttr(D, MA->getRange(), AttrSpellingListIndex);
2474 else if (const auto *OA = dyn_cast<OptimizeNoneAttr>(Attr))
2475 NewAttr = S.mergeOptimizeNoneAttr(D, OA->getRange(), AttrSpellingListIndex);
2476 else if (const auto *InternalLinkageA = dyn_cast<InternalLinkageAttr>(Attr))
2477 NewAttr = S.mergeInternalLinkageAttr(
2478 D, InternalLinkageA->getRange(),
2479 &S.Context.Idents.get(InternalLinkageA->getSpelling()),
2480 AttrSpellingListIndex);
2481 else if (const auto *CommonA = dyn_cast<CommonAttr>(Attr))
2482 NewAttr = S.mergeCommonAttr(D, CommonA->getRange(),
2483 &S.Context.Idents.get(CommonA->getSpelling()),
2484 AttrSpellingListIndex);
2485 else if (isa<AlignedAttr>(Attr))
2486 // AlignedAttrs are handled separately, because we need to handle all
2487 // such attributes on a declaration at the same time.
2489 else if ((isa<DeprecatedAttr>(Attr) || isa<UnavailableAttr>(Attr)) &&
2490 (AMK == Sema::AMK_Override ||
2491 AMK == Sema::AMK_ProtocolImplementation))
2493 else if (const auto *UA = dyn_cast<UuidAttr>(Attr))
2494 NewAttr = S.mergeUuidAttr(D, UA->getRange(), AttrSpellingListIndex,
2496 else if (Attr->shouldInheritEvenIfAlreadyPresent() || !DeclHasAttr(D, Attr))
2497 NewAttr = cast<InheritableAttr>(Attr->clone(S.Context));
2500 NewAttr->setInherited(true);
2501 D->addAttr(NewAttr);
2502 if (isa<MSInheritanceAttr>(NewAttr))
2503 S.Consumer.AssignInheritanceModel(cast<CXXRecordDecl>(D));
2510 static const NamedDecl *getDefinition(const Decl *D) {
2511 if (const TagDecl *TD = dyn_cast<TagDecl>(D))
2512 return TD->getDefinition();
2513 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
2514 const VarDecl *Def = VD->getDefinition();
2517 return VD->getActingDefinition();
2519 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
2520 return FD->getDefinition();
2524 static bool hasAttribute(const Decl *D, attr::Kind Kind) {
2525 for (const auto *Attribute : D->attrs())
2526 if (Attribute->getKind() == Kind)
2531 /// checkNewAttributesAfterDef - If we already have a definition, check that
2532 /// there are no new attributes in this declaration.
2533 static void checkNewAttributesAfterDef(Sema &S, Decl *New, const Decl *Old) {
2534 if (!New->hasAttrs())
2537 const NamedDecl *Def = getDefinition(Old);
2538 if (!Def || Def == New)
2541 AttrVec &NewAttributes = New->getAttrs();
2542 for (unsigned I = 0, E = NewAttributes.size(); I != E;) {
2543 const Attr *NewAttribute = NewAttributes[I];
2545 if (isa<AliasAttr>(NewAttribute) || isa<IFuncAttr>(NewAttribute)) {
2546 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(New)) {
2547 Sema::SkipBodyInfo SkipBody;
2548 S.CheckForFunctionRedefinition(FD, cast<FunctionDecl>(Def), &SkipBody);
2550 // If we're skipping this definition, drop the "alias" attribute.
2551 if (SkipBody.ShouldSkip) {
2552 NewAttributes.erase(NewAttributes.begin() + I);
2557 VarDecl *VD = cast<VarDecl>(New);
2558 unsigned Diag = cast<VarDecl>(Def)->isThisDeclarationADefinition() ==
2559 VarDecl::TentativeDefinition
2560 ? diag::err_alias_after_tentative
2561 : diag::err_redefinition;
2562 S.Diag(VD->getLocation(), Diag) << VD->getDeclName();
2563 if (Diag == diag::err_redefinition)
2564 S.notePreviousDefinition(Def, VD->getLocation());
2566 S.Diag(Def->getLocation(), diag::note_previous_definition);
2567 VD->setInvalidDecl();
2573 if (const VarDecl *VD = dyn_cast<VarDecl>(Def)) {
2574 // Tentative definitions are only interesting for the alias check above.
2575 if (VD->isThisDeclarationADefinition() != VarDecl::Definition) {
2581 if (hasAttribute(Def, NewAttribute->getKind())) {
2583 continue; // regular attr merging will take care of validating this.
2586 if (isa<C11NoReturnAttr>(NewAttribute)) {
2587 // C's _Noreturn is allowed to be added to a function after it is defined.
2590 } else if (const AlignedAttr *AA = dyn_cast<AlignedAttr>(NewAttribute)) {
2591 if (AA->isAlignas()) {
2592 // C++11 [dcl.align]p6:
2593 // if any declaration of an entity has an alignment-specifier,
2594 // every defining declaration of that entity shall specify an
2595 // equivalent alignment.
2597 // If the definition of an object does not have an alignment
2598 // specifier, any other declaration of that object shall also
2599 // have no alignment specifier.
2600 S.Diag(Def->getLocation(), diag::err_alignas_missing_on_definition)
2602 S.Diag(NewAttribute->getLocation(), diag::note_alignas_on_declaration)
2604 NewAttributes.erase(NewAttributes.begin() + I);
2610 S.Diag(NewAttribute->getLocation(),
2611 diag::warn_attribute_precede_definition);
2612 S.Diag(Def->getLocation(), diag::note_previous_definition);
2613 NewAttributes.erase(NewAttributes.begin() + I);
2618 /// mergeDeclAttributes - Copy attributes from the Old decl to the New one.
2619 void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
2620 AvailabilityMergeKind AMK) {
2621 if (UsedAttr *OldAttr = Old->getMostRecentDecl()->getAttr<UsedAttr>()) {
2622 UsedAttr *NewAttr = OldAttr->clone(Context);
2623 NewAttr->setInherited(true);
2624 New->addAttr(NewAttr);
2627 if (!Old->hasAttrs() && !New->hasAttrs())
2630 // Attributes declared post-definition are currently ignored.
2631 checkNewAttributesAfterDef(*this, New, Old);
2633 if (AsmLabelAttr *NewA = New->getAttr<AsmLabelAttr>()) {
2634 if (AsmLabelAttr *OldA = Old->getAttr<AsmLabelAttr>()) {
2635 if (OldA->getLabel() != NewA->getLabel()) {
2636 // This redeclaration changes __asm__ label.
2637 Diag(New->getLocation(), diag::err_different_asm_label);
2638 Diag(OldA->getLocation(), diag::note_previous_declaration);
2640 } else if (Old->isUsed()) {
2641 // This redeclaration adds an __asm__ label to a declaration that has
2642 // already been ODR-used.
2643 Diag(New->getLocation(), diag::err_late_asm_label_name)
2644 << isa<FunctionDecl>(Old) << New->getAttr<AsmLabelAttr>()->getRange();
2648 // Re-declaration cannot add abi_tag's.
2649 if (const auto *NewAbiTagAttr = New->getAttr<AbiTagAttr>()) {
2650 if (const auto *OldAbiTagAttr = Old->getAttr<AbiTagAttr>()) {
2651 for (const auto &NewTag : NewAbiTagAttr->tags()) {
2652 if (std::find(OldAbiTagAttr->tags_begin(), OldAbiTagAttr->tags_end(),
2653 NewTag) == OldAbiTagAttr->tags_end()) {
2654 Diag(NewAbiTagAttr->getLocation(),
2655 diag::err_new_abi_tag_on_redeclaration)
2657 Diag(OldAbiTagAttr->getLocation(), diag::note_previous_declaration);
2661 Diag(NewAbiTagAttr->getLocation(), diag::err_abi_tag_on_redeclaration);
2662 Diag(Old->getLocation(), diag::note_previous_declaration);
2666 // This redeclaration adds a section attribute.
2667 if (New->hasAttr<SectionAttr>() && !Old->hasAttr<SectionAttr>()) {
2668 if (auto *VD = dyn_cast<VarDecl>(New)) {
2669 if (VD->isThisDeclarationADefinition() == VarDecl::DeclarationOnly) {
2670 Diag(New->getLocation(), diag::warn_attribute_section_on_redeclaration);
2671 Diag(Old->getLocation(), diag::note_previous_declaration);
2676 // Redeclaration adds code-seg attribute.
2677 const auto *NewCSA = New->getAttr<CodeSegAttr>();
2678 if (NewCSA && !Old->hasAttr<CodeSegAttr>() &&
2679 !NewCSA->isImplicit() && isa<CXXMethodDecl>(New)) {
2680 Diag(New->getLocation(), diag::warn_mismatched_section)
2682 Diag(Old->getLocation(), diag::note_previous_declaration);
2685 if (!Old->hasAttrs())
2688 bool foundAny = New->hasAttrs();
2690 // Ensure that any moving of objects within the allocated map is done before
2692 if (!foundAny) New->setAttrs(AttrVec());
2694 for (auto *I : Old->specific_attrs<InheritableAttr>()) {
2695 // Ignore deprecated/unavailable/availability attributes if requested.
2696 AvailabilityMergeKind LocalAMK = AMK_None;
2697 if (isa<DeprecatedAttr>(I) ||
2698 isa<UnavailableAttr>(I) ||
2699 isa<AvailabilityAttr>(I)) {
2704 case AMK_Redeclaration:
2706 case AMK_ProtocolImplementation:
2713 if (isa<UsedAttr>(I))
2716 if (mergeDeclAttribute(*this, New, I, LocalAMK))
2720 if (mergeAlignedAttrs(*this, New, Old))
2723 if (!foundAny) New->dropAttrs();
2726 /// mergeParamDeclAttributes - Copy attributes from the old parameter
2728 static void mergeParamDeclAttributes(ParmVarDecl *newDecl,
2729 const ParmVarDecl *oldDecl,
2731 // C++11 [dcl.attr.depend]p2:
2732 // The first declaration of a function shall specify the
2733 // carries_dependency attribute for its declarator-id if any declaration
2734 // of the function specifies the carries_dependency attribute.
2735 const CarriesDependencyAttr *CDA = newDecl->getAttr<CarriesDependencyAttr>();
2736 if (CDA && !oldDecl->hasAttr<CarriesDependencyAttr>()) {
2737 S.Diag(CDA->getLocation(),
2738 diag::err_carries_dependency_missing_on_first_decl) << 1/*Param*/;
2739 // Find the first declaration of the parameter.
2740 // FIXME: Should we build redeclaration chains for function parameters?
2741 const FunctionDecl *FirstFD =
2742 cast<FunctionDecl>(oldDecl->getDeclContext())->getFirstDecl();
2743 const ParmVarDecl *FirstVD =
2744 FirstFD->getParamDecl(oldDecl->getFunctionScopeIndex());
2745 S.Diag(FirstVD->getLocation(),
2746 diag::note_carries_dependency_missing_first_decl) << 1/*Param*/;
2749 if (!oldDecl->hasAttrs())
2752 bool foundAny = newDecl->hasAttrs();
2754 // Ensure that any moving of objects within the allocated map is
2755 // done before we process them.
2756 if (!foundAny) newDecl->setAttrs(AttrVec());
2758 for (const auto *I : oldDecl->specific_attrs<InheritableParamAttr>()) {
2759 if (!DeclHasAttr(newDecl, I)) {
2760 InheritableAttr *newAttr =
2761 cast<InheritableParamAttr>(I->clone(S.Context));
2762 newAttr->setInherited(true);
2763 newDecl->addAttr(newAttr);
2768 if (!foundAny) newDecl->dropAttrs();
2771 static void mergeParamDeclTypes(ParmVarDecl *NewParam,
2772 const ParmVarDecl *OldParam,
2774 if (auto Oldnullability = OldParam->getType()->getNullability(S.Context)) {
2775 if (auto Newnullability = NewParam->getType()->getNullability(S.Context)) {
2776 if (*Oldnullability != *Newnullability) {
2777 S.Diag(NewParam->getLocation(), diag::warn_mismatched_nullability_attr)
2778 << DiagNullabilityKind(
2780 ((NewParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
2782 << DiagNullabilityKind(
2784 ((OldParam->getObjCDeclQualifier() & Decl::OBJC_TQ_CSNullability)
2786 S.Diag(OldParam->getLocation(), diag::note_previous_declaration);
2789 QualType NewT = NewParam->getType();
2790 NewT = S.Context.getAttributedType(
2791 AttributedType::getNullabilityAttrKind(*Oldnullability),
2793 NewParam->setType(NewT);
2800 /// Used in MergeFunctionDecl to keep track of function parameters in
2802 struct GNUCompatibleParamWarning {
2803 ParmVarDecl *OldParm;
2804 ParmVarDecl *NewParm;
2805 QualType PromotedType;
2808 } // end anonymous namespace
2810 /// getSpecialMember - get the special member enum for a method.
2811 Sema::CXXSpecialMember Sema::getSpecialMember(const CXXMethodDecl *MD) {
2812 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
2813 if (Ctor->isDefaultConstructor())
2814 return Sema::CXXDefaultConstructor;
2816 if (Ctor->isCopyConstructor())
2817 return Sema::CXXCopyConstructor;
2819 if (Ctor->isMoveConstructor())
2820 return Sema::CXXMoveConstructor;
2821 } else if (isa<CXXDestructorDecl>(MD)) {
2822 return Sema::CXXDestructor;
2823 } else if (MD->isCopyAssignmentOperator()) {
2824 return Sema::CXXCopyAssignment;
2825 } else if (MD->isMoveAssignmentOperator()) {
2826 return Sema::CXXMoveAssignment;
2829 return Sema::CXXInvalid;
2832 // Determine whether the previous declaration was a definition, implicit
2833 // declaration, or a declaration.
2834 template <typename T>
2835 static std::pair<diag::kind, SourceLocation>
2836 getNoteDiagForInvalidRedeclaration(const T *Old, const T *New) {
2837 diag::kind PrevDiag;
2838 SourceLocation OldLocation = Old->getLocation();
2839 if (Old->isThisDeclarationADefinition())
2840 PrevDiag = diag::note_previous_definition;
2841 else if (Old->isImplicit()) {
2842 PrevDiag = diag::note_previous_implicit_declaration;
2843 if (OldLocation.isInvalid())
2844 OldLocation = New->getLocation();
2846 PrevDiag = diag::note_previous_declaration;
2847 return std::make_pair(PrevDiag, OldLocation);
2850 /// canRedefineFunction - checks if a function can be redefined. Currently,
2851 /// only extern inline functions can be redefined, and even then only in
2853 static bool canRedefineFunction(const FunctionDecl *FD,
2854 const LangOptions& LangOpts) {
2855 return ((FD->hasAttr<GNUInlineAttr>() || LangOpts.GNUInline) &&
2856 !LangOpts.CPlusPlus &&
2857 FD->isInlineSpecified() &&
2858 FD->getStorageClass() == SC_Extern);
2861 const AttributedType *Sema::getCallingConvAttributedType(QualType T) const {
2862 const AttributedType *AT = T->getAs<AttributedType>();
2863 while (AT && !AT->isCallingConv())
2864 AT = AT->getModifiedType()->getAs<AttributedType>();
2868 template <typename T>
2869 static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
2870 const DeclContext *DC = Old->getDeclContext();
2874 LanguageLinkage OldLinkage = Old->getLanguageLinkage();
2875 if (OldLinkage == CXXLanguageLinkage && New->isInExternCContext())
2877 if (OldLinkage == CLanguageLinkage && New->isInExternCXXContext())
2882 template<typename T> static bool isExternC(T *D) { return D->isExternC(); }
2883 static bool isExternC(VarTemplateDecl *) { return false; }
2885 /// Check whether a redeclaration of an entity introduced by a
2886 /// using-declaration is valid, given that we know it's not an overload
2887 /// (nor a hidden tag declaration).
2888 template<typename ExpectedDecl>
2889 static bool checkUsingShadowRedecl(Sema &S, UsingShadowDecl *OldS,
2890 ExpectedDecl *New) {
2891 // C++11 [basic.scope.declarative]p4:
2892 // Given a set of declarations in a single declarative region, each of
2893 // which specifies the same unqualified name,
2894 // -- they shall all refer to the same entity, or all refer to functions
2895 // and function templates; or
2896 // -- exactly one declaration shall declare a class name or enumeration
2897 // name that is not a typedef name and the other declarations shall all
2898 // refer to the same variable or enumerator, or all refer to functions
2899 // and function templates; in this case the class name or enumeration
2900 // name is hidden (3.3.10).
2902 // C++11 [namespace.udecl]p14:
2903 // If a function declaration in namespace scope or block scope has the
2904 // same name and the same parameter-type-list as a function introduced
2905 // by a using-declaration, and the declarations do not declare the same
2906 // function, the program is ill-formed.
2908 auto *Old = dyn_cast<ExpectedDecl>(OldS->getTargetDecl());
2910 !Old->getDeclContext()->getRedeclContext()->Equals(
2911 New->getDeclContext()->getRedeclContext()) &&
2912 !(isExternC(Old) && isExternC(New)))
2916 S.Diag(New->getLocation(), diag::err_using_decl_conflict_reverse);
2917 S.Diag(OldS->getTargetDecl()->getLocation(), diag::note_using_decl_target);
2918 S.Diag(OldS->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
2924 static bool hasIdenticalPassObjectSizeAttrs(const FunctionDecl *A,
2925 const FunctionDecl *B) {
2926 assert(A->getNumParams() == B->getNumParams());
2928 auto AttrEq = [](const ParmVarDecl *A, const ParmVarDecl *B) {
2929 const auto *AttrA = A->getAttr<PassObjectSizeAttr>();
2930 const auto *AttrB = B->getAttr<PassObjectSizeAttr>();
2933 return AttrA && AttrB && AttrA->getType() == AttrB->getType();
2936 return std::equal(A->param_begin(), A->param_end(), B->param_begin(), AttrEq);
2939 /// If necessary, adjust the semantic declaration context for a qualified
2940 /// declaration to name the correct inline namespace within the qualifier.
2941 static void adjustDeclContextForDeclaratorDecl(DeclaratorDecl *NewD,
2942 DeclaratorDecl *OldD) {
2943 // The only case where we need to update the DeclContext is when
2944 // redeclaration lookup for a qualified name finds a declaration
2945 // in an inline namespace within the context named by the qualifier:
2947 // inline namespace N { int f(); }
2948 // int ::f(); // Sema DC needs adjusting from :: to N::.
2950 // For unqualified declarations, the semantic context *can* change
2951 // along the redeclaration chain (for local extern declarations,
2952 // extern "C" declarations, and friend declarations in particular).
2953 if (!NewD->getQualifier())
2956 // NewD is probably already in the right context.
2957 auto *NamedDC = NewD->getDeclContext()->getRedeclContext();
2958 auto *SemaDC = OldD->getDeclContext()->getRedeclContext();
2959 if (NamedDC->Equals(SemaDC))
2962 assert((NamedDC->InEnclosingNamespaceSetOf(SemaDC) ||
2963 NewD->isInvalidDecl() || OldD->isInvalidDecl()) &&
2964 "unexpected context for redeclaration");
2966 auto *LexDC = NewD->getLexicalDeclContext();
2967 auto FixSemaDC = [=](NamedDecl *D) {
2970 D->setDeclContext(SemaDC);
2971 D->setLexicalDeclContext(LexDC);
2975 if (auto *FD = dyn_cast<FunctionDecl>(NewD))
2976 FixSemaDC(FD->getDescribedFunctionTemplate());
2977 else if (auto *VD = dyn_cast<VarDecl>(NewD))
2978 FixSemaDC(VD->getDescribedVarTemplate());
2981 /// MergeFunctionDecl - We just parsed a function 'New' from
2982 /// declarator D which has the same name and scope as a previous
2983 /// declaration 'Old'. Figure out how to resolve this situation,
2984 /// merging decls or emitting diagnostics as appropriate.
2986 /// In C++, New and Old must be declarations that are not
2987 /// overloaded. Use IsOverload to determine whether New and Old are
2988 /// overloaded, and to select the Old declaration that New should be
2991 /// Returns true if there was an error, false otherwise.
2992 bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD,
2993 Scope *S, bool MergeTypeWithOld) {
2994 // Verify the old decl was also a function.
2995 FunctionDecl *Old = OldD->getAsFunction();
2997 if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(OldD)) {
2998 if (New->getFriendObjectKind()) {
2999 Diag(New->getLocation(), diag::err_using_decl_friend);
3000 Diag(Shadow->getTargetDecl()->getLocation(),
3001 diag::note_using_decl_target);
3002 Diag(Shadow->getUsingDecl()->getLocation(),
3003 diag::note_using_decl) << 0;
3007 // Check whether the two declarations might declare the same function.
3008 if (checkUsingShadowRedecl<FunctionDecl>(*this, Shadow, New))
3010 OldD = Old = cast<FunctionDecl>(Shadow->getTargetDecl());
3012 Diag(New->getLocation(), diag::err_redefinition_different_kind)
3013 << New->getDeclName();
3014 notePreviousDefinition(OldD, New->getLocation());
3019 // If the old declaration is invalid, just give up here.
3020 if (Old->isInvalidDecl())
3023 // Disallow redeclaration of some builtins.
3024 if (!getASTContext().canBuiltinBeRedeclared(Old)) {
3025 Diag(New->getLocation(), diag::err_builtin_redeclare) << Old->getDeclName();
3026 Diag(Old->getLocation(), diag::note_previous_builtin_declaration)
3027 << Old << Old->getType();
3031 diag::kind PrevDiag;
3032 SourceLocation OldLocation;
3033 std::tie(PrevDiag, OldLocation) =
3034 getNoteDiagForInvalidRedeclaration(Old, New);
3036 // Don't complain about this if we're in GNU89 mode and the old function
3037 // is an extern inline function.
3038 // Don't complain about specializations. They are not supposed to have
3040 if (!isa<CXXMethodDecl>(New) && !isa<CXXMethodDecl>(Old) &&
3041 New->getStorageClass() == SC_Static &&
3042 Old->hasExternalFormalLinkage() &&
3043 !New->getTemplateSpecializationInfo() &&
3044 !canRedefineFunction(Old, getLangOpts())) {
3045 if (getLangOpts().MicrosoftExt) {
3046 Diag(New->getLocation(), diag::ext_static_non_static) << New;
3047 Diag(OldLocation, PrevDiag);
3049 Diag(New->getLocation(), diag::err_static_non_static) << New;
3050 Diag(OldLocation, PrevDiag);
3055 if (New->hasAttr<InternalLinkageAttr>() &&
3056 !Old->hasAttr<InternalLinkageAttr>()) {
3057 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
3058 << New->getDeclName();
3059 notePreviousDefinition(Old, New->getLocation());
3060 New->dropAttr<InternalLinkageAttr>();
3063 if (CheckRedeclarationModuleOwnership(New, Old))
3066 if (!getLangOpts().CPlusPlus) {
3067 bool OldOvl = Old->hasAttr<OverloadableAttr>();
3068 if (OldOvl != New->hasAttr<OverloadableAttr>() && !Old->isImplicit()) {
3069 Diag(New->getLocation(), diag::err_attribute_overloadable_mismatch)
3072 // Try our best to find a decl that actually has the overloadable
3073 // attribute for the note. In most cases (e.g. programs with only one
3074 // broken declaration/definition), this won't matter.
3076 // FIXME: We could do this if we juggled some extra state in
3077 // OverloadableAttr, rather than just removing it.
3078 const Decl *DiagOld = Old;
3080 auto OldIter = llvm::find_if(Old->redecls(), [](const Decl *D) {
3081 const auto *A = D->getAttr<OverloadableAttr>();
3082 return A && !A->isImplicit();
3084 // If we've implicitly added *all* of the overloadable attrs to this
3085 // chain, emitting a "previous redecl" note is pointless.
3086 DiagOld = OldIter == Old->redecls_end() ? nullptr : *OldIter;
3090 Diag(DiagOld->getLocation(),
3091 diag::note_attribute_overloadable_prev_overload)
3095 New->addAttr(OverloadableAttr::CreateImplicit(Context));
3097 New->dropAttr<OverloadableAttr>();
3101 // If a function is first declared with a calling convention, but is later
3102 // declared or defined without one, all following decls assume the calling
3103 // convention of the first.
3105 // It's OK if a function is first declared without a calling convention,
3106 // but is later declared or defined with the default calling convention.
3108 // To test if either decl has an explicit calling convention, we look for
3109 // AttributedType sugar nodes on the type as written. If they are missing or
3110 // were canonicalized away, we assume the calling convention was implicit.
3112 // Note also that we DO NOT return at this point, because we still have
3113 // other tests to run.
3114 QualType OldQType = Context.getCanonicalType(Old->getType());
3115 QualType NewQType = Context.getCanonicalType(New->getType());
3116 const FunctionType *OldType = cast<FunctionType>(OldQType);
3117 const FunctionType *NewType = cast<FunctionType>(NewQType);
3118 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
3119 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
3120 bool RequiresAdjustment = false;
3122 if (OldTypeInfo.getCC() != NewTypeInfo.getCC()) {
3123 FunctionDecl *First = Old->getFirstDecl();
3124 const FunctionType *FT =
3125 First->getType().getCanonicalType()->castAs<FunctionType>();
3126 FunctionType::ExtInfo FI = FT->getExtInfo();
3127 bool NewCCExplicit = getCallingConvAttributedType(New->getType());
3128 if (!NewCCExplicit) {
3129 // Inherit the CC from the previous declaration if it was specified
3130 // there but not here.
3131 NewTypeInfo = NewTypeInfo.withCallingConv(OldTypeInfo.getCC());
3132 RequiresAdjustment = true;
3134 // Calling conventions aren't compatible, so complain.
3135 bool FirstCCExplicit = getCallingConvAttributedType(First->getType());
3136 Diag(New->getLocation(), diag::err_cconv_change)
3137 << FunctionType::getNameForCallConv(NewTypeInfo.getCC())
3139 << (!FirstCCExplicit ? "" :
3140 FunctionType::getNameForCallConv(FI.getCC()));
3142 // Put the note on the first decl, since it is the one that matters.
3143 Diag(First->getLocation(), diag::note_previous_declaration);
3148 // FIXME: diagnose the other way around?
3149 if (OldTypeInfo.getNoReturn() && !NewTypeInfo.getNoReturn()) {
3150 NewTypeInfo = NewTypeInfo.withNoReturn(true);
3151 RequiresAdjustment = true;
3154 // Merge regparm attribute.
3155 if (OldTypeInfo.getHasRegParm() != NewTypeInfo.getHasRegParm() ||
3156 OldTypeInfo.getRegParm() != NewTypeInfo.getRegParm()) {
3157 if (NewTypeInfo.getHasRegParm()) {
3158 Diag(New->getLocation(), diag::err_regparm_mismatch)
3159 << NewType->getRegParmType()
3160 << OldType->getRegParmType();
3161 Diag(OldLocation, diag::note_previous_declaration);
3165 NewTypeInfo = NewTypeInfo.withRegParm(OldTypeInfo.getRegParm());
3166 RequiresAdjustment = true;
3169 // Merge ns_returns_retained attribute.
3170 if (OldTypeInfo.getProducesResult() != NewTypeInfo.getProducesResult()) {
3171 if (NewTypeInfo.getProducesResult()) {
3172 Diag(New->getLocation(), diag::err_function_attribute_mismatch)
3173 << "'ns_returns_retained'";
3174 Diag(OldLocation, diag::note_previous_declaration);
3178 NewTypeInfo = NewTypeInfo.withProducesResult(true);
3179 RequiresAdjustment = true;
3182 if (OldTypeInfo.getNoCallerSavedRegs() !=
3183 NewTypeInfo.getNoCallerSavedRegs()) {
3184 if (NewTypeInfo.getNoCallerSavedRegs()) {
3185 AnyX86NoCallerSavedRegistersAttr *Attr =
3186 New->getAttr<AnyX86NoCallerSavedRegistersAttr>();
3187 Diag(New->getLocation(), diag::err_function_attribute_mismatch) << Attr;
3188 Diag(OldLocation, diag::note_previous_declaration);
3192 NewTypeInfo = NewTypeInfo.withNoCallerSavedRegs(true);
3193 RequiresAdjustment = true;
3196 if (RequiresAdjustment) {
3197 const FunctionType *AdjustedType = New->getType()->getAs<FunctionType>();
3198 AdjustedType = Context.adjustFunctionType(AdjustedType, NewTypeInfo);
3199 New->setType(QualType(AdjustedType, 0));
3200 NewQType = Context.getCanonicalType(New->getType());
3201 NewType = cast<FunctionType>(NewQType);
3204 // If this redeclaration makes the function inline, we may need to add it to
3205 // UndefinedButUsed.
3206 if (!Old->isInlined() && New->isInlined() &&
3207 !New->hasAttr<GNUInlineAttr>() &&
3208 !getLangOpts().GNUInline &&
3209 Old->isUsed(false) &&
3210 !Old->isDefined() && !New->isThisDeclarationADefinition())
3211 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
3214 // If this redeclaration makes it newly gnu_inline, we don't want to warn
3216 if (New->hasAttr<GNUInlineAttr>() &&
3217 Old->isInlined() && !Old->hasAttr<GNUInlineAttr>()) {
3218 UndefinedButUsed.erase(Old->getCanonicalDecl());
3221 // If pass_object_size params don't match up perfectly, this isn't a valid
3223 if (Old->getNumParams() > 0 && Old->getNumParams() == New->getNumParams() &&
3224 !hasIdenticalPassObjectSizeAttrs(Old, New)) {
3225 Diag(New->getLocation(), diag::err_different_pass_object_size_params)
3226 << New->getDeclName();
3227 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3231 if (getLangOpts().CPlusPlus) {
3232 // C++1z [over.load]p2
3233 // Certain function declarations cannot be overloaded:
3234 // -- Function declarations that differ only in the return type,
3235 // the exception specification, or both cannot be overloaded.
3237 // Check the exception specifications match. This may recompute the type of
3238 // both Old and New if it resolved exception specifications, so grab the
3239 // types again after this. Because this updates the type, we do this before
3240 // any of the other checks below, which may update the "de facto" NewQType
3241 // but do not necessarily update the type of New.
3242 if (CheckEquivalentExceptionSpec(Old, New))
3244 OldQType = Context.getCanonicalType(Old->getType());
3245 NewQType = Context.getCanonicalType(New->getType());
3247 // Go back to the type source info to compare the declared return types,
3248 // per C++1y [dcl.type.auto]p13:
3249 // Redeclarations or specializations of a function or function template
3250 // with a declared return type that uses a placeholder type shall also
3251 // use that placeholder, not a deduced type.
3252 QualType OldDeclaredReturnType = Old->getDeclaredReturnType();
3253 QualType NewDeclaredReturnType = New->getDeclaredReturnType();
3254 if (!Context.hasSameType(OldDeclaredReturnType, NewDeclaredReturnType) &&
3255 canFullyTypeCheckRedeclaration(New, Old, NewDeclaredReturnType,
3256 OldDeclaredReturnType)) {
3258 if (NewDeclaredReturnType->isObjCObjectPointerType() &&
3259 OldDeclaredReturnType->isObjCObjectPointerType())
3260 // FIXME: This does the wrong thing for a deduced return type.
3261 ResQT = Context.mergeObjCGCQualifiers(NewQType, OldQType);
3262 if (ResQT.isNull()) {
3263 if (New->isCXXClassMember() && New->isOutOfLine())
3264 Diag(New->getLocation(), diag::err_member_def_does_not_match_ret_type)
3265 << New << New->getReturnTypeSourceRange();
3267 Diag(New->getLocation(), diag::err_ovl_diff_return_type)
3268 << New->getReturnTypeSourceRange();
3269 Diag(OldLocation, PrevDiag) << Old << Old->getType()
3270 << Old->getReturnTypeSourceRange();
3277 QualType OldReturnType = OldType->getReturnType();
3278 QualType NewReturnType = cast<FunctionType>(NewQType)->getReturnType();
3279 if (OldReturnType != NewReturnType) {
3280 // If this function has a deduced return type and has already been
3281 // defined, copy the deduced value from the old declaration.
3282 AutoType *OldAT = Old->getReturnType()->getContainedAutoType();
3283 if (OldAT && OldAT->isDeduced()) {
3285 SubstAutoType(New->getType(),
3286 OldAT->isDependentType() ? Context.DependentTy
3287 : OldAT->getDeducedType()));
3288 NewQType = Context.getCanonicalType(
3289 SubstAutoType(NewQType,
3290 OldAT->isDependentType() ? Context.DependentTy
3291 : OldAT->getDeducedType()));
3295 const CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old);
3296 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New);
3297 if (OldMethod && NewMethod) {
3298 // Preserve triviality.
3299 NewMethod->setTrivial(OldMethod->isTrivial());
3301 // MSVC allows explicit template specialization at class scope:
3302 // 2 CXXMethodDecls referring to the same function will be injected.
3303 // We don't want a redeclaration error.
3304 bool IsClassScopeExplicitSpecialization =
3305 OldMethod->isFunctionTemplateSpecialization() &&
3306 NewMethod->isFunctionTemplateSpecialization();
3307 bool isFriend = NewMethod->getFriendObjectKind();
3309 if (!isFriend && NewMethod->getLexicalDeclContext()->isRecord() &&
3310 !IsClassScopeExplicitSpecialization) {
3311 // -- Member function declarations with the same name and the
3312 // same parameter types cannot be overloaded if any of them
3313 // is a static member function declaration.
3314 if (OldMethod->isStatic() != NewMethod->isStatic()) {
3315 Diag(New->getLocation(), diag::err_ovl_static_nonstatic_member);
3316 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3320 // C++ [class.mem]p1:
3321 // [...] A member shall not be declared twice in the
3322 // member-specification, except that a nested class or member
3323 // class template can be declared and then later defined.
3324 if (!inTemplateInstantiation()) {
3326 if (isa<CXXConstructorDecl>(OldMethod))
3327 NewDiag = diag::err_constructor_redeclared;
3328 else if (isa<CXXDestructorDecl>(NewMethod))
3329 NewDiag = diag::err_destructor_redeclared;
3330 else if (isa<CXXConversionDecl>(NewMethod))
3331 NewDiag = diag::err_conv_function_redeclared;
3333 NewDiag = diag::err_member_redeclared;
3335 Diag(New->getLocation(), NewDiag);
3337 Diag(New->getLocation(), diag::err_member_redeclared_in_instantiation)
3338 << New << New->getType();
3340 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3343 // Complain if this is an explicit declaration of a special
3344 // member that was initially declared implicitly.
3346 // As an exception, it's okay to befriend such methods in order
3347 // to permit the implicit constructor/destructor/operator calls.
3348 } else if (OldMethod->isImplicit()) {
3350 NewMethod->setImplicit();
3352 Diag(NewMethod->getLocation(),
3353 diag::err_definition_of_implicitly_declared_member)
3354 << New << getSpecialMember(OldMethod);
3357 } else if (OldMethod->getFirstDecl()->isExplicitlyDefaulted() && !isFriend) {
3358 Diag(NewMethod->getLocation(),
3359 diag::err_definition_of_explicitly_defaulted_member)
3360 << getSpecialMember(OldMethod);
3365 // C++11 [dcl.attr.noreturn]p1:
3366 // The first declaration of a function shall specify the noreturn
3367 // attribute if any declaration of that function specifies the noreturn
3369 const CXX11NoReturnAttr *NRA = New->getAttr<CXX11NoReturnAttr>();
3370 if (NRA && !Old->hasAttr<CXX11NoReturnAttr>()) {
3371 Diag(NRA->getLocation(), diag::err_noreturn_missing_on_first_decl);
3372 Diag(Old->getFirstDecl()->getLocation(),
3373 diag::note_noreturn_missing_first_decl);
3376 // C++11 [dcl.attr.depend]p2:
3377 // The first declaration of a function shall specify the
3378 // carries_dependency attribute for its declarator-id if any declaration
3379 // of the function specifies the carries_dependency attribute.
3380 const CarriesDependencyAttr *CDA = New->getAttr<CarriesDependencyAttr>();
3381 if (CDA && !Old->hasAttr<CarriesDependencyAttr>()) {
3382 Diag(CDA->getLocation(),
3383 diag::err_carries_dependency_missing_on_first_decl) << 0/*Function*/;
3384 Diag(Old->getFirstDecl()->getLocation(),
3385 diag::note_carries_dependency_missing_first_decl) << 0/*Function*/;
3389 // All declarations for a function shall agree exactly in both the
3390 // return type and the parameter-type-list.
3391 // We also want to respect all the extended bits except noreturn.
3393 // noreturn should now match unless the old type info didn't have it.
3394 QualType OldQTypeForComparison = OldQType;
3395 if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
3396 auto *OldType = OldQType->castAs<FunctionProtoType>();
3397 const FunctionType *OldTypeForComparison
3398 = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
3399 OldQTypeForComparison = QualType(OldTypeForComparison, 0);
3400 assert(OldQTypeForComparison.isCanonical());
3403 if (haveIncompatibleLanguageLinkages(Old, New)) {
3404 // As a special case, retain the language linkage from previous
3405 // declarations of a friend function as an extension.
3407 // This liberal interpretation of C++ [class.friend]p3 matches GCC/MSVC
3408 // and is useful because there's otherwise no way to specify language
3409 // linkage within class scope.
3411 // Check cautiously as the friend object kind isn't yet complete.
3412 if (New->getFriendObjectKind() != Decl::FOK_None) {
3413 Diag(New->getLocation(), diag::ext_retained_language_linkage) << New;
3414 Diag(OldLocation, PrevDiag);
3416 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
3417 Diag(OldLocation, PrevDiag);
3422 if (OldQTypeForComparison == NewQType)
3423 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3425 // If the types are imprecise (due to dependent constructs in friends or
3426 // local extern declarations), it's OK if they differ. We'll check again
3427 // during instantiation.
3428 if (!canFullyTypeCheckRedeclaration(New, Old, NewQType, OldQType))
3431 // Fall through for conflicting redeclarations and redefinitions.
3434 // C: Function types need to be compatible, not identical. This handles
3435 // duplicate function decls like "void f(int); void f(enum X);" properly.
3436 if (!getLangOpts().CPlusPlus &&
3437 Context.typesAreCompatible(OldQType, NewQType)) {
3438 const FunctionType *OldFuncType = OldQType->getAs<FunctionType>();
3439 const FunctionType *NewFuncType = NewQType->getAs<FunctionType>();
3440 const FunctionProtoType *OldProto = nullptr;
3441 if (MergeTypeWithOld && isa<FunctionNoProtoType>(NewFuncType) &&
3442 (OldProto = dyn_cast<FunctionProtoType>(OldFuncType))) {
3443 // The old declaration provided a function prototype, but the
3444 // new declaration does not. Merge in the prototype.
3445 assert(!OldProto->hasExceptionSpec() && "Exception spec in C");
3446 SmallVector<QualType, 16> ParamTypes(OldProto->param_types());
3448 Context.getFunctionType(NewFuncType->getReturnType(), ParamTypes,
3449 OldProto->getExtProtoInfo());
3450 New->setType(NewQType);
3451 New->setHasInheritedPrototype();
3453 // Synthesize parameters with the same types.
3454 SmallVector<ParmVarDecl*, 16> Params;
3455 for (const auto &ParamType : OldProto->param_types()) {
3456 ParmVarDecl *Param = ParmVarDecl::Create(Context, New, SourceLocation(),
3457 SourceLocation(), nullptr,
3458 ParamType, /*TInfo=*/nullptr,
3460 Param->setScopeInfo(0, Params.size());
3461 Param->setImplicit();
3462 Params.push_back(Param);
3465 New->setParams(Params);
3468 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3471 // GNU C permits a K&R definition to follow a prototype declaration
3472 // if the declared types of the parameters in the K&R definition
3473 // match the types in the prototype declaration, even when the
3474 // promoted types of the parameters from the K&R definition differ
3475 // from the types in the prototype. GCC then keeps the types from
3478 // If a variadic prototype is followed by a non-variadic K&R definition,
3479 // the K&R definition becomes variadic. This is sort of an edge case, but
3480 // it's legal per the standard depending on how you read C99 6.7.5.3p15 and
3482 if (!getLangOpts().CPlusPlus &&
3483 Old->hasPrototype() && !New->hasPrototype() &&
3484 New->getType()->getAs<FunctionProtoType>() &&
3485 Old->getNumParams() == New->getNumParams()) {
3486 SmallVector<QualType, 16> ArgTypes;
3487 SmallVector<GNUCompatibleParamWarning, 16> Warnings;
3488 const FunctionProtoType *OldProto
3489 = Old->getType()->getAs<FunctionProtoType>();
3490 const FunctionProtoType *NewProto
3491 = New->getType()->getAs<FunctionProtoType>();
3493 // Determine whether this is the GNU C extension.
3494 QualType MergedReturn = Context.mergeTypes(OldProto->getReturnType(),
3495 NewProto->getReturnType());
3496 bool LooseCompatible = !MergedReturn.isNull();
3497 for (unsigned Idx = 0, End = Old->getNumParams();
3498 LooseCompatible && Idx != End; ++Idx) {
3499 ParmVarDecl *OldParm = Old->getParamDecl(Idx);
3500 ParmVarDecl *NewParm = New->getParamDecl(Idx);
3501 if (Context.typesAreCompatible(OldParm->getType(),
3502 NewProto->getParamType(Idx))) {
3503 ArgTypes.push_back(NewParm->getType());
3504 } else if (Context.typesAreCompatible(OldParm->getType(),
3506 /*CompareUnqualified=*/true)) {
3507 GNUCompatibleParamWarning Warn = { OldParm, NewParm,
3508 NewProto->getParamType(Idx) };
3509 Warnings.push_back(Warn);
3510 ArgTypes.push_back(NewParm->getType());
3512 LooseCompatible = false;
3515 if (LooseCompatible) {
3516 for (unsigned Warn = 0; Warn < Warnings.size(); ++Warn) {
3517 Diag(Warnings[Warn].NewParm->getLocation(),
3518 diag::ext_param_promoted_not_compatible_with_prototype)
3519 << Warnings[Warn].PromotedType
3520 << Warnings[Warn].OldParm->getType();
3521 if (Warnings[Warn].OldParm->getLocation().isValid())
3522 Diag(Warnings[Warn].OldParm->getLocation(),
3523 diag::note_previous_declaration);
3526 if (MergeTypeWithOld)
3527 New->setType(Context.getFunctionType(MergedReturn, ArgTypes,
3528 OldProto->getExtProtoInfo()));
3529 return MergeCompatibleFunctionDecls(New, Old, S, MergeTypeWithOld);
3532 // Fall through to diagnose conflicting types.
3535 // A function that has already been declared has been redeclared or
3536 // defined with a different type; show an appropriate diagnostic.
3538 // If the previous declaration was an implicitly-generated builtin
3539 // declaration, then at the very least we should use a specialized note.
3541 if (Old->isImplicit() && (BuiltinID = Old->getBuiltinID())) {
3542 // If it's actually a library-defined builtin function like 'malloc'
3543 // or 'printf', just warn about the incompatible redeclaration.
3544 if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
3545 Diag(New->getLocation(), diag::warn_redecl_library_builtin) << New;
3546 Diag(OldLocation, diag::note_previous_builtin_declaration)
3547 << Old << Old->getType();
3549 // If this is a global redeclaration, just forget hereafter
3550 // about the "builtin-ness" of the function.
3552 // Doing this for local extern declarations is problematic. If
3553 // the builtin declaration remains visible, a second invalid
3554 // local declaration will produce a hard error; if it doesn't
3555 // remain visible, a single bogus local redeclaration (which is
3556 // actually only a warning) could break all the downstream code.
3557 if (!New->getLexicalDeclContext()->isFunctionOrMethod())
3558 New->getIdentifier()->revertBuiltin();
3563 PrevDiag = diag::note_previous_builtin_declaration;
3566 Diag(New->getLocation(), diag::err_conflicting_types) << New->getDeclName();
3567 Diag(OldLocation, PrevDiag) << Old << Old->getType();
3571 /// Completes the merge of two function declarations that are
3572 /// known to be compatible.
3574 /// This routine handles the merging of attributes and other
3575 /// properties of function declarations from the old declaration to
3576 /// the new declaration, once we know that New is in fact a
3577 /// redeclaration of Old.
3580 bool Sema::MergeCompatibleFunctionDecls(FunctionDecl *New, FunctionDecl *Old,
3581 Scope *S, bool MergeTypeWithOld) {
3582 // Merge the attributes
3583 mergeDeclAttributes(New, Old);
3585 // Merge "pure" flag.
3589 // Merge "used" flag.
3590 if (Old->getMostRecentDecl()->isUsed(false))
3593 // Merge attributes from the parameters. These can mismatch with K&R
3595 if (New->getNumParams() == Old->getNumParams())
3596 for (unsigned i = 0, e = New->getNumParams(); i != e; ++i) {
3597 ParmVarDecl *NewParam = New->getParamDecl(i);
3598 ParmVarDecl *OldParam = Old->getParamDecl(i);
3599 mergeParamDeclAttributes(NewParam, OldParam, *this);
3600 mergeParamDeclTypes(NewParam, OldParam, *this);
3603 if (getLangOpts().CPlusPlus)
3604 return MergeCXXFunctionDecl(New, Old, S);
3606 // Merge the function types so the we get the composite types for the return
3607 // and argument types. Per C11 6.2.7/4, only update the type if the old decl
3609 QualType Merged = Context.mergeTypes(Old->getType(), New->getType());
3610 if (!Merged.isNull() && MergeTypeWithOld)
3611 New->setType(Merged);
3616 void Sema::mergeObjCMethodDecls(ObjCMethodDecl *newMethod,
3617 ObjCMethodDecl *oldMethod) {
3618 // Merge the attributes, including deprecated/unavailable
3619 AvailabilityMergeKind MergeKind =
3620 isa<ObjCProtocolDecl>(oldMethod->getDeclContext())
3621 ? AMK_ProtocolImplementation
3622 : isa<ObjCImplDecl>(newMethod->getDeclContext()) ? AMK_Redeclaration
3625 mergeDeclAttributes(newMethod, oldMethod, MergeKind);
3627 // Merge attributes from the parameters.
3628 ObjCMethodDecl::param_const_iterator oi = oldMethod->param_begin(),
3629 oe = oldMethod->param_end();
3630 for (ObjCMethodDecl::param_iterator
3631 ni = newMethod->param_begin(), ne = newMethod->param_end();
3632 ni != ne && oi != oe; ++ni, ++oi)
3633 mergeParamDeclAttributes(*ni, *oi, *this);
3635 CheckObjCMethodOverride(newMethod, oldMethod);
3638 static void diagnoseVarDeclTypeMismatch(Sema &S, VarDecl *New, VarDecl* Old) {
3639 assert(!S.Context.hasSameType(New->getType(), Old->getType()));
3641 S.Diag(New->getLocation(), New->isThisDeclarationADefinition()
3642 ? diag::err_redefinition_different_type
3643 : diag::err_redeclaration_different_type)
3644 << New->getDeclName() << New->getType() << Old->getType();
3646 diag::kind PrevDiag;
3647 SourceLocation OldLocation;
3648 std::tie(PrevDiag, OldLocation)
3649 = getNoteDiagForInvalidRedeclaration(Old, New);
3650 S.Diag(OldLocation, PrevDiag);
3651 New->setInvalidDecl();
3654 /// MergeVarDeclTypes - We parsed a variable 'New' which has the same name and
3655 /// scope as a previous declaration 'Old'. Figure out how to merge their types,
3656 /// emitting diagnostics as appropriate.
3658 /// Declarations using the auto type specifier (C++ [decl.spec.auto]) call back
3659 /// to here in AddInitializerToDecl. We can't check them before the initializer
3661 void Sema::MergeVarDeclTypes(VarDecl *New, VarDecl *Old,
3662 bool MergeTypeWithOld) {
3663 if (New->isInvalidDecl() || Old->isInvalidDecl())
3667 if (getLangOpts().CPlusPlus) {
3668 if (New->getType()->isUndeducedType()) {
3669 // We don't know what the new type is until the initializer is attached.
3671 } else if (Context.hasSameType(New->getType(), Old->getType())) {
3672 // These could still be something that needs exception specs checked.
3673 return MergeVarDeclExceptionSpecs(New, Old);
3675 // C++ [basic.link]p10:
3676 // [...] the types specified by all declarations referring to a given
3677 // object or function shall be identical, except that declarations for an
3678 // array object can specify array types that differ by the presence or
3679 // absence of a major array bound (8.3.4).
3680 else if (Old->getType()->isArrayType() && New->getType()->isArrayType()) {
3681 const ArrayType *OldArray = Context.getAsArrayType(Old->getType());
3682 const ArrayType *NewArray = Context.getAsArrayType(New->getType());
3684 // We are merging a variable declaration New into Old. If it has an array
3685 // bound, and that bound differs from Old's bound, we should diagnose the
3687 if (!NewArray->isIncompleteArrayType() && !NewArray->isDependentType()) {
3688 for (VarDecl *PrevVD = Old->getMostRecentDecl(); PrevVD;
3689 PrevVD = PrevVD->getPreviousDecl()) {
3690 const ArrayType *PrevVDTy = Context.getAsArrayType(PrevVD->getType());
3691 if (PrevVDTy->isIncompleteArrayType() || PrevVDTy->isDependentType())
3694 if (!Context.hasSameType(NewArray, PrevVDTy))
3695 return diagnoseVarDeclTypeMismatch(*this, New, PrevVD);
3699 if (OldArray->isIncompleteArrayType() && NewArray->isArrayType()) {
3700 if (Context.hasSameType(OldArray->getElementType(),
3701 NewArray->getElementType()))
3702 MergedT = New->getType();
3704 // FIXME: Check visibility. New is hidden but has a complete type. If New
3705 // has no array bound, it should not inherit one from Old, if Old is not
3707 else if (OldArray->isArrayType() && NewArray->isIncompleteArrayType()) {
3708 if (Context.hasSameType(OldArray->getElementType(),
3709 NewArray->getElementType()))
3710 MergedT = Old->getType();
3713 else if (New->getType()->isObjCObjectPointerType() &&
3714 Old->getType()->isObjCObjectPointerType()) {
3715 MergedT = Context.mergeObjCGCQualifiers(New->getType(),
3720 // All declarations that refer to the same object or function shall have
3722 MergedT = Context.mergeTypes(New->getType(), Old->getType());
3724 if (MergedT.isNull()) {
3725 // It's OK if we couldn't merge types if either type is dependent, for a
3726 // block-scope variable. In other cases (static data members of class
3727 // templates, variable templates, ...), we require the types to be
3729 // FIXME: The C++ standard doesn't say anything about this.
3730 if ((New->getType()->isDependentType() ||
3731 Old->getType()->isDependentType()) && New->isLocalVarDecl()) {
3732 // If the old type was dependent, we can't merge with it, so the new type
3733 // becomes dependent for now. We'll reproduce the original type when we
3734 // instantiate the TypeSourceInfo for the variable.
3735 if (!New->getType()->isDependentType() && MergeTypeWithOld)
3736 New->setType(Context.DependentTy);
3739 return diagnoseVarDeclTypeMismatch(*this, New, Old);
3742 // Don't actually update the type on the new declaration if the old
3743 // declaration was an extern declaration in a different scope.
3744 if (MergeTypeWithOld)
3745 New->setType(MergedT);
3748 static bool mergeTypeWithPrevious(Sema &S, VarDecl *NewVD, VarDecl *OldVD,
3749 LookupResult &Previous) {
3751 // For an identifier with internal or external linkage declared
3752 // in a scope in which a prior declaration of that identifier is
3753 // visible, if the prior declaration specifies internal or
3754 // external linkage, the type of the identifier at the later
3755 // declaration becomes the composite type.
3757 // If the variable isn't visible, we do not merge with its type.
3758 if (Previous.isShadowed())
3761 if (S.getLangOpts().CPlusPlus) {
3762 // C++11 [dcl.array]p3:
3763 // If there is a preceding declaration of the entity in the same
3764 // scope in which the bound was specified, an omitted array bound
3765 // is taken to be the same as in that earlier declaration.
3766 return NewVD->isPreviousDeclInSameBlockScope() ||
3767 (!OldVD->getLexicalDeclContext()->isFunctionOrMethod() &&
3768 !NewVD->getLexicalDeclContext()->isFunctionOrMethod());
3770 // If the old declaration was function-local, don't merge with its
3771 // type unless we're in the same function.
3772 return !OldVD->getLexicalDeclContext()->isFunctionOrMethod() ||
3773 OldVD->getLexicalDeclContext() == NewVD->getLexicalDeclContext();
3777 /// MergeVarDecl - We just parsed a variable 'New' which has the same name
3778 /// and scope as a previous declaration 'Old'. Figure out how to resolve this
3779 /// situation, merging decls or emitting diagnostics as appropriate.
3781 /// Tentative definition rules (C99 6.9.2p2) are checked by
3782 /// FinalizeDeclaratorGroup. Unfortunately, we can't analyze tentative
3783 /// definitions here, since the initializer hasn't been attached.
3785 void Sema::MergeVarDecl(VarDecl *New, LookupResult &Previous) {
3786 // If the new decl is already invalid, don't do any other checking.
3787 if (New->isInvalidDecl())
3790 if (!shouldLinkPossiblyHiddenDecl(Previous, New))
3793 VarTemplateDecl *NewTemplate = New->getDescribedVarTemplate();
3795 // Verify the old decl was also a variable or variable template.
3796 VarDecl *Old = nullptr;
3797 VarTemplateDecl *OldTemplate = nullptr;
3798 if (Previous.isSingleResult()) {
3800 OldTemplate = dyn_cast<VarTemplateDecl>(Previous.getFoundDecl());
3801 Old = OldTemplate ? OldTemplate->getTemplatedDecl() : nullptr;
3804 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
3805 if (checkUsingShadowRedecl<VarTemplateDecl>(*this, Shadow, NewTemplate))
3806 return New->setInvalidDecl();
3808 Old = dyn_cast<VarDecl>(Previous.getFoundDecl());
3811 dyn_cast<UsingShadowDecl>(Previous.getRepresentativeDecl()))
3812 if (checkUsingShadowRedecl<VarDecl>(*this, Shadow, New))
3813 return New->setInvalidDecl();
3817 Diag(New->getLocation(), diag::err_redefinition_different_kind)
3818 << New->getDeclName();
3819 notePreviousDefinition(Previous.getRepresentativeDecl(),
3820 New->getLocation());
3821 return New->setInvalidDecl();
3824 // Ensure the template parameters are compatible.
3826 !TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(),
3827 OldTemplate->getTemplateParameters(),
3828 /*Complain=*/true, TPL_TemplateMatch))
3829 return New->setInvalidDecl();
3831 // C++ [class.mem]p1:
3832 // A member shall not be declared twice in the member-specification [...]
3834 // Here, we need only consider static data members.
3835 if (Old->isStaticDataMember() && !New->isOutOfLine()) {
3836 Diag(New->getLocation(), diag::err_duplicate_member)
3837 << New->getIdentifier();
3838 Diag(Old->getLocation(), diag::note_previous_declaration);
3839 New->setInvalidDecl();
3842 mergeDeclAttributes(New, Old);
3843 // Warn if an already-declared variable is made a weak_import in a subsequent
3845 if (New->hasAttr<WeakImportAttr>() &&
3846 Old->getStorageClass() == SC_None &&
3847 !Old->hasAttr<WeakImportAttr>()) {
3848 Diag(New->getLocation(), diag::warn_weak_import) << New->getDeclName();
3849 notePreviousDefinition(Old, New->getLocation());
3850 // Remove weak_import attribute on new declaration.
3851 New->dropAttr<WeakImportAttr>();
3854 if (New->hasAttr<InternalLinkageAttr>() &&
3855 !Old->hasAttr<InternalLinkageAttr>()) {
3856 Diag(New->getLocation(), diag::err_internal_linkage_redeclaration)
3857 << New->getDeclName();
3858 notePreviousDefinition(Old, New->getLocation());
3859 New->dropAttr<InternalLinkageAttr>();
3863 VarDecl *MostRecent = Old->getMostRecentDecl();
3864 if (MostRecent != Old) {
3865 MergeVarDeclTypes(New, MostRecent,
3866 mergeTypeWithPrevious(*this, New, MostRecent, Previous));
3867 if (New->isInvalidDecl())
3871 MergeVarDeclTypes(New, Old, mergeTypeWithPrevious(*this, New, Old, Previous));
3872 if (New->isInvalidDecl())
3875 diag::kind PrevDiag;
3876 SourceLocation OldLocation;
3877 std::tie(PrevDiag, OldLocation) =
3878 getNoteDiagForInvalidRedeclaration(Old, New);
3880 // [dcl.stc]p8: Check if we have a non-static decl followed by a static.
3881 if (New->getStorageClass() == SC_Static &&
3882 !New->isStaticDataMember() &&
3883 Old->hasExternalFormalLinkage()) {
3884 if (getLangOpts().MicrosoftExt) {
3885 Diag(New->getLocation(), diag::ext_static_non_static)
3886 << New->getDeclName();
3887 Diag(OldLocation, PrevDiag);
3889 Diag(New->getLocation(), diag::err_static_non_static)
3890 << New->getDeclName();
3891 Diag(OldLocation, PrevDiag);
3892 return New->setInvalidDecl();
3896 // For an identifier declared with the storage-class specifier
3897 // extern in a scope in which a prior declaration of that
3898 // identifier is visible,23) if the prior declaration specifies
3899 // internal or external linkage, the linkage of the identifier at
3900 // the later declaration is the same as the linkage specified at
3901 // the prior declaration. If no prior declaration is visible, or
3902 // if the prior declaration specifies no linkage, then the
3903 // identifier has external linkage.
3904 if (New->hasExternalStorage() && Old->hasLinkage())
3906 else if (New->getCanonicalDecl()->getStorageClass() != SC_Static &&
3907 !New->isStaticDataMember() &&
3908 Old->getCanonicalDecl()->getStorageClass() == SC_Static) {
3909 Diag(New->getLocation(), diag::err_non_static_static) << New->getDeclName();
3910 Diag(OldLocation, PrevDiag);
3911 return New->setInvalidDecl();
3914 // Check if extern is followed by non-extern and vice-versa.
3915 if (New->hasExternalStorage() &&
3916 !Old->hasLinkage() && Old->isLocalVarDeclOrParm()) {
3917 Diag(New->getLocation(), diag::err_extern_non_extern) << New->getDeclName();
3918 Diag(OldLocation, PrevDiag);
3919 return New->setInvalidDecl();
3921 if (Old->hasLinkage() && New->isLocalVarDeclOrParm() &&
3922 !New->hasExternalStorage()) {
3923 Diag(New->getLocation(), diag::err_non_extern_extern) << New->getDeclName();
3924 Diag(OldLocation, PrevDiag);
3925 return New->setInvalidDecl();
3928 if (CheckRedeclarationModuleOwnership(New, Old))
3931 // Variables with external linkage are analyzed in FinalizeDeclaratorGroup.
3933 // FIXME: The test for external storage here seems wrong? We still
3934 // need to check for mismatches.
3935 if (!New->hasExternalStorage() && !New->isFileVarDecl() &&
3936 // Don't complain about out-of-line definitions of static members.
3937 !(Old->getLexicalDeclContext()->isRecord() &&
3938 !New->getLexicalDeclContext()->isRecord())) {
3939 Diag(New->getLocation(), diag::err_redefinition) << New->getDeclName();
3940 Diag(OldLocation, PrevDiag);
3941 return New->setInvalidDecl();
3944 if (New->isInline() && !Old->getMostRecentDecl()->isInline()) {
3945 if (VarDecl *Def = Old->getDefinition()) {
3946 // C++1z [dcl.fcn.spec]p4:
3947 // If the definition of a variable appears in a translation unit before
3948 // its first declaration as inline, the program is ill-formed.
3949 Diag(New->getLocation(), diag::err_inline_decl_follows_def) << New;
3950 Diag(Def->getLocation(), diag::note_previous_definition);
3954 // If this redeclaration makes the variable inline, we may need to add it to
3955 // UndefinedButUsed.
3956 if (!Old->isInline() && New->isInline() && Old->isUsed(false) &&
3957 !Old->getDefinition() && !New->isThisDeclarationADefinition())
3958 UndefinedButUsed.insert(std::make_pair(Old->getCanonicalDecl(),
3961 if (New->getTLSKind() != Old->getTLSKind()) {
3962 if (!Old->getTLSKind()) {
3963 Diag(New->getLocation(), diag::err_thread_non_thread) << New->getDeclName();
3964 Diag(OldLocation, PrevDiag);
3965 } else if (!New->getTLSKind()) {
3966 Diag(New->getLocation(), diag::err_non_thread_thread) << New->getDeclName();
3967 Diag(OldLocation, PrevDiag);
3969 // Do not allow redeclaration to change the variable between requiring
3970 // static and dynamic initialization.
3971 // FIXME: GCC allows this, but uses the TLS keyword on the first
3972 // declaration to determine the kind. Do we need to be compatible here?
3973 Diag(New->getLocation(), diag::err_thread_thread_different_kind)
3974 << New->getDeclName() << (New->getTLSKind() == VarDecl::TLS_Dynamic);
3975 Diag(OldLocation, PrevDiag);
3979 // C++ doesn't have tentative definitions, so go right ahead and check here.
3980 if (getLangOpts().CPlusPlus &&
3981 New->isThisDeclarationADefinition() == VarDecl::Definition) {
3982 if (Old->isStaticDataMember() && Old->getCanonicalDecl()->isInline() &&
3983 Old->getCanonicalDecl()->isConstexpr()) {
3984 // This definition won't be a definition any more once it's been merged.
3985 Diag(New->getLocation(),
3986 diag::warn_deprecated_redundant_constexpr_static_def);
3987 } else if (VarDecl *Def = Old->getDefinition()) {
3988 if (checkVarDeclRedefinition(Def, New))
3993 if (haveIncompatibleLanguageLinkages(Old, New)) {
3994 Diag(New->getLocation(), diag::err_different_language_linkage) << New;
3995 Diag(OldLocation, PrevDiag);
3996 New->setInvalidDecl();
4000 // Merge "used" flag.
4001 if (Old->getMostRecentDecl()->isUsed(false))
4004 // Keep a chain of previous declarations.
4005 New->setPreviousDecl(Old);
4007 NewTemplate->setPreviousDecl(OldTemplate);
4008 adjustDeclContextForDeclaratorDecl(New, Old);
4010 // Inherit access appropriately.
4011 New->setAccess(Old->getAccess());
4013 NewTemplate->setAccess(New->getAccess());
4015 if (Old->isInline())
4016 New->setImplicitlyInline();
4019 void Sema::notePreviousDefinition(const NamedDecl *Old, SourceLocation New) {
4020 SourceManager &SrcMgr = getSourceManager();
4021 auto FNewDecLoc = SrcMgr.getDecomposedLoc(New);
4022 auto FOldDecLoc = SrcMgr.getDecomposedLoc(Old->getLocation());
4023 auto *FNew = SrcMgr.getFileEntryForID(FNewDecLoc.first);
4024 auto *FOld = SrcMgr.getFileEntryForID(FOldDecLoc.first);
4025 auto &HSI = PP.getHeaderSearchInfo();
4026 StringRef HdrFilename =
4027 SrcMgr.getFilename(SrcMgr.getSpellingLoc(Old->getLocation()));
4029 auto noteFromModuleOrInclude = [&](Module *Mod,
4030 SourceLocation IncLoc) -> bool {
4031 // Redefinition errors with modules are common with non modular mapped
4032 // headers, example: a non-modular header H in module A that also gets
4033 // included directly in a TU. Pointing twice to the same header/definition
4034 // is confusing, try to get better diagnostics when modules is on.
4035 if (IncLoc.isValid()) {
4037 Diag(IncLoc, diag::note_redefinition_modules_same_file)
4038 << HdrFilename.str() << Mod->getFullModuleName();
4039 if (!Mod->DefinitionLoc.isInvalid())
4040 Diag(Mod->DefinitionLoc, diag::note_defined_here)
4041 << Mod->getFullModuleName();
4043 Diag(IncLoc, diag::note_redefinition_include_same_file)
4044 << HdrFilename.str();
4052 // Is it the same file and same offset? Provide more information on why
4053 // this leads to a redefinition error.
4054 bool EmittedDiag = false;
4055 if (FNew == FOld && FNewDecLoc.second == FOldDecLoc.second) {
4056 SourceLocation OldIncLoc = SrcMgr.getIncludeLoc(FOldDecLoc.first);
4057 SourceLocation NewIncLoc = SrcMgr.getIncludeLoc(FNewDecLoc.first);
4058 EmittedDiag = noteFromModuleOrInclude(Old->getOwningModule(), OldIncLoc);
4059 EmittedDiag |= noteFromModuleOrInclude(getCurrentModule(), NewIncLoc);
4061 // If the header has no guards, emit a note suggesting one.
4062 if (FOld && !HSI.isFileMultipleIncludeGuarded(FOld))
4063 Diag(Old->getLocation(), diag::note_use_ifdef_guards);
4069 // Redefinition coming from different files or couldn't do better above.
4070 if (Old->getLocation().isValid())
4071 Diag(Old->getLocation(), diag::note_previous_definition);
4074 /// We've just determined that \p Old and \p New both appear to be definitions
4075 /// of the same variable. Either diagnose or fix the problem.
4076 bool Sema::checkVarDeclRedefinition(VarDecl *Old, VarDecl *New) {
4077 if (!hasVisibleDefinition(Old) &&
4078 (New->getFormalLinkage() == InternalLinkage ||
4080 New->getDescribedVarTemplate() ||
4081 New->getNumTemplateParameterLists() ||
4082 New->getDeclContext()->isDependentContext())) {
4083 // The previous definition is hidden, and multiple definitions are
4084 // permitted (in separate TUs). Demote this to a declaration.
4085 New->demoteThisDefinitionToDeclaration();
4087 // Make the canonical definition visible.
4088 if (auto *OldTD = Old->getDescribedVarTemplate())
4089 makeMergedDefinitionVisible(OldTD);
4090 makeMergedDefinitionVisible(Old);
4093 Diag(New->getLocation(), diag::err_redefinition) << New;
4094 notePreviousDefinition(Old, New->getLocation());
4095 New->setInvalidDecl();
4100 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4101 /// no declarator (e.g. "struct foo;") is parsed.
4103 Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4104 RecordDecl *&AnonRecord) {
4105 return ParsedFreeStandingDeclSpec(S, AS, DS, MultiTemplateParamsArg(), false,
4109 // The MS ABI changed between VS2013 and VS2015 with regard to numbers used to
4110 // disambiguate entities defined in different scopes.
4111 // While the VS2015 ABI fixes potential miscompiles, it is also breaks
4113 // We will pick our mangling number depending on which version of MSVC is being
4115 static unsigned getMSManglingNumber(const LangOptions &LO, Scope *S) {
4116 return LO.isCompatibleWithMSVC(LangOptions::MSVC2015)
4117 ? S->getMSCurManglingNumber()
4118 : S->getMSLastManglingNumber();
4121 void Sema::handleTagNumbering(const TagDecl *Tag, Scope *TagScope) {
4122 if (!Context.getLangOpts().CPlusPlus)
4125 if (isa<CXXRecordDecl>(Tag->getParent())) {
4126 // If this tag is the direct child of a class, number it if
4128 if (!Tag->getName().empty() || Tag->getTypedefNameForAnonDecl())
4130 MangleNumberingContext &MCtx =
4131 Context.getManglingNumberContext(Tag->getParent());
4132 Context.setManglingNumber(
4133 Tag, MCtx.getManglingNumber(
4134 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4138 // If this tag isn't a direct child of a class, number it if it is local.
4139 Decl *ManglingContextDecl;
4140 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
4141 Tag->getDeclContext(), ManglingContextDecl)) {
4142 Context.setManglingNumber(
4143 Tag, MCtx->getManglingNumber(
4144 Tag, getMSManglingNumber(getLangOpts(), TagScope)));
4148 void Sema::setTagNameForLinkagePurposes(TagDecl *TagFromDeclSpec,
4149 TypedefNameDecl *NewTD) {
4150 if (TagFromDeclSpec->isInvalidDecl())
4153 // Do nothing if the tag already has a name for linkage purposes.
4154 if (TagFromDeclSpec->hasNameForLinkage())
4157 // A well-formed anonymous tag must always be a TUK_Definition.
4158 assert(TagFromDeclSpec->isThisDeclarationADefinition());
4160 // The type must match the tag exactly; no qualifiers allowed.
4161 if (!Context.hasSameType(NewTD->getUnderlyingType(),
4162 Context.getTagDeclType(TagFromDeclSpec))) {
4163 if (getLangOpts().CPlusPlus)
4164 Context.addTypedefNameForUnnamedTagDecl(TagFromDeclSpec, NewTD);
4168 // If we've already computed linkage for the anonymous tag, then
4169 // adding a typedef name for the anonymous decl can change that
4170 // linkage, which might be a serious problem. Diagnose this as
4171 // unsupported and ignore the typedef name. TODO: we should
4172 // pursue this as a language defect and establish a formal rule
4173 // for how to handle it.
4174 if (TagFromDeclSpec->hasLinkageBeenComputed()) {
4175 Diag(NewTD->getLocation(), diag::err_typedef_changes_linkage);
4177 SourceLocation tagLoc = TagFromDeclSpec->getInnerLocStart();
4178 tagLoc = getLocForEndOfToken(tagLoc);
4180 llvm::SmallString<40> textToInsert;
4181 textToInsert += ' ';
4182 textToInsert += NewTD->getIdentifier()->getName();
4183 Diag(tagLoc, diag::note_typedef_changes_linkage)
4184 << FixItHint::CreateInsertion(tagLoc, textToInsert);
4188 // Otherwise, set this is the anon-decl typedef for the tag.
4189 TagFromDeclSpec->setTypedefNameForAnonDecl(NewTD);
4192 static unsigned GetDiagnosticTypeSpecifierID(DeclSpec::TST T) {
4194 case DeclSpec::TST_class:
4196 case DeclSpec::TST_struct:
4198 case DeclSpec::TST_interface:
4200 case DeclSpec::TST_union:
4202 case DeclSpec::TST_enum:
4205 llvm_unreachable("unexpected type specifier");
4209 /// ParsedFreeStandingDeclSpec - This method is invoked when a declspec with
4210 /// no declarator (e.g. "struct foo;") is parsed. It also accepts template
4211 /// parameters to cope with template friend declarations.
4213 Sema::ParsedFreeStandingDeclSpec(Scope *S, AccessSpecifier AS, DeclSpec &DS,
4214 MultiTemplateParamsArg TemplateParams,
4215 bool IsExplicitInstantiation,
4216 RecordDecl *&AnonRecord) {
4217 Decl *TagD = nullptr;
4218 TagDecl *Tag = nullptr;
4219 if (DS.getTypeSpecType() == DeclSpec::TST_class ||
4220 DS.getTypeSpecType() == DeclSpec::TST_struct ||
4221 DS.getTypeSpecType() == DeclSpec::TST_interface ||
4222 DS.getTypeSpecType() == DeclSpec::TST_union ||
4223 DS.getTypeSpecType() == DeclSpec::TST_enum) {
4224 TagD = DS.getRepAsDecl();
4226 if (!TagD) // We probably had an error
4229 // Note that the above type specs guarantee that the
4230 // type rep is a Decl, whereas in many of the others
4232 if (isa<TagDecl>(TagD))
4233 Tag = cast<TagDecl>(TagD);
4234 else if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(TagD))
4235 Tag = CTD->getTemplatedDecl();
4239 handleTagNumbering(Tag, S);
4240 Tag->setFreeStanding();
4241 if (Tag->isInvalidDecl())
4245 if (unsigned TypeQuals = DS.getTypeQualifiers()) {
4246 // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
4247 // or incomplete types shall not be restrict-qualified."
4248 if (TypeQuals & DeclSpec::TQ_restrict)
4249 Diag(DS.getRestrictSpecLoc(),
4250 diag::err_typecheck_invalid_restrict_not_pointer_noarg)
4251 << DS.getSourceRange();
4254 if (DS.isInlineSpecified())
4255 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
4256 << getLangOpts().CPlusPlus17;
4258 if (DS.isConstexprSpecified()) {
4259 // C++0x [dcl.constexpr]p1: constexpr can only be applied to declarations
4260 // and definitions of functions and variables.
4262 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_tag)
4263 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType());
4265 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_no_declarators);
4266 // Don't emit warnings after this error.
4270 DiagnoseFunctionSpecifiers(DS);
4272 if (DS.isFriendSpecified()) {
4273 // If we're dealing with a decl but not a TagDecl, assume that
4274 // whatever routines created it handled the friendship aspect.
4277 return ActOnFriendTypeDecl(S, DS, TemplateParams);
4280 const CXXScopeSpec &SS = DS.getTypeSpecScope();
4281 bool IsExplicitSpecialization =
4282 !TemplateParams.empty() && TemplateParams.back()->size() == 0;
4283 if (Tag && SS.isNotEmpty() && !Tag->isCompleteDefinition() &&
4284 !IsExplicitInstantiation && !IsExplicitSpecialization &&
4285 !isa<ClassTemplatePartialSpecializationDecl>(Tag)) {
4286 // Per C++ [dcl.type.elab]p1, a class declaration cannot have a
4287 // nested-name-specifier unless it is an explicit instantiation
4288 // or an explicit specialization.
4290 // FIXME: We allow class template partial specializations here too, per the
4291 // obvious intent of DR1819.
4293 // Per C++ [dcl.enum]p1, an opaque-enum-declaration can't either.
4294 Diag(SS.getBeginLoc(), diag::err_standalone_class_nested_name_specifier)
4295 << GetDiagnosticTypeSpecifierID(DS.getTypeSpecType()) << SS.getRange();
4299 // Track whether this decl-specifier declares anything.
4300 bool DeclaresAnything = true;
4302 // Handle anonymous struct definitions.
4303 if (RecordDecl *Record = dyn_cast_or_null<RecordDecl>(Tag)) {
4304 if (!Record->getDeclName() && Record->isCompleteDefinition() &&
4305 DS.getStorageClassSpec() != DeclSpec::SCS_typedef) {
4306 if (getLangOpts().CPlusPlus ||
4307 Record->getDeclContext()->isRecord()) {
4308 // If CurContext is a DeclContext that can contain statements,
4309 // RecursiveASTVisitor won't visit the decls that
4310 // BuildAnonymousStructOrUnion() will put into CurContext.
4311 // Also store them here so that they can be part of the
4312 // DeclStmt that gets created in this case.
4313 // FIXME: Also return the IndirectFieldDecls created by
4314 // BuildAnonymousStructOr union, for the same reason?
4315 if (CurContext->isFunctionOrMethod())
4316 AnonRecord = Record;
4317 return BuildAnonymousStructOrUnion(S, DS, AS, Record,
4318 Context.getPrintingPolicy());
4321 DeclaresAnything = false;
4326 // A struct-declaration that does not declare an anonymous structure or
4327 // anonymous union shall contain a struct-declarator-list.
4329 // This rule also existed in C89 and C99; the grammar for struct-declaration
4330 // did not permit a struct-declaration without a struct-declarator-list.
4331 if (!getLangOpts().CPlusPlus && CurContext->isRecord() &&
4332 DS.getStorageClassSpec() == DeclSpec::SCS_unspecified) {
4333 // Check for Microsoft C extension: anonymous struct/union member.
4334 // Handle 2 kinds of anonymous struct/union:
4338 // STRUCT_TYPE; <- where STRUCT_TYPE is a typedef struct.
4339 // UNION_TYPE; <- where UNION_TYPE is a typedef union.
4340 if ((Tag && Tag->getDeclName()) ||
4341 DS.getTypeSpecType() == DeclSpec::TST_typename) {
4342 RecordDecl *Record = nullptr;
4344 Record = dyn_cast<RecordDecl>(Tag);
4345 else if (const RecordType *RT =
4346 DS.getRepAsType().get()->getAsStructureType())
4347 Record = RT->getDecl();
4348 else if (const RecordType *UT = DS.getRepAsType().get()->getAsUnionType())
4349 Record = UT->getDecl();
4351 if (Record && getLangOpts().MicrosoftExt) {
4352 Diag(DS.getLocStart(), diag::ext_ms_anonymous_record)
4353 << Record->isUnion() << DS.getSourceRange();
4354 return BuildMicrosoftCAnonymousStruct(S, DS, Record);
4357 DeclaresAnything = false;
4361 // Skip all the checks below if we have a type error.
4362 if (DS.getTypeSpecType() == DeclSpec::TST_error ||
4363 (TagD && TagD->isInvalidDecl()))
4366 if (getLangOpts().CPlusPlus &&
4367 DS.getStorageClassSpec() != DeclSpec::SCS_typedef)
4368 if (EnumDecl *Enum = dyn_cast_or_null<EnumDecl>(Tag))
4369 if (Enum->enumerator_begin() == Enum->enumerator_end() &&
4370 !Enum->getIdentifier() && !Enum->isInvalidDecl())
4371 DeclaresAnything = false;
4373 if (!DS.isMissingDeclaratorOk()) {
4374 // Customize diagnostic for a typedef missing a name.
4375 if (DS.getStorageClassSpec() == DeclSpec::SCS_typedef)
4376 Diag(DS.getLocStart(), diag::ext_typedef_without_a_name)
4377 << DS.getSourceRange();
4379 DeclaresAnything = false;
4382 if (DS.isModulePrivateSpecified() &&
4383 Tag && Tag->getDeclContext()->isFunctionOrMethod())
4384 Diag(DS.getModulePrivateSpecLoc(), diag::err_module_private_local_class)
4385 << Tag->getTagKind()
4386 << FixItHint::CreateRemoval(DS.getModulePrivateSpecLoc());
4388 ActOnDocumentableDecl(TagD);
4391 // A declaration [...] shall declare at least a declarator [...], a tag,
4392 // or the members of an enumeration.
4394 // [If there are no declarators], and except for the declaration of an
4395 // unnamed bit-field, the decl-specifier-seq shall introduce one or more
4396 // names into the program, or shall redeclare a name introduced by a
4397 // previous declaration.
4398 if (!DeclaresAnything) {
4399 // In C, we allow this as a (popular) extension / bug. Don't bother
4400 // producing further diagnostics for redundant qualifiers after this.
4401 Diag(DS.getLocStart(), diag::ext_no_declarators) << DS.getSourceRange();
4406 // If a storage-class-specifier appears in a decl-specifier-seq, [...] the
4407 // init-declarator-list of the declaration shall not be empty.
4408 // C++ [dcl.fct.spec]p1:
4409 // If a cv-qualifier appears in a decl-specifier-seq, the
4410 // init-declarator-list of the declaration shall not be empty.
4412 // Spurious qualifiers here appear to be valid in C.
4413 unsigned DiagID = diag::warn_standalone_specifier;
4414 if (getLangOpts().CPlusPlus)
4415 DiagID = diag::ext_standalone_specifier;
4417 // Note that a linkage-specification sets a storage class, but
4418 // 'extern "C" struct foo;' is actually valid and not theoretically
4420 if (DeclSpec::SCS SCS = DS.getStorageClassSpec()) {
4421 if (SCS == DeclSpec::SCS_mutable)
4422 // Since mutable is not a viable storage class specifier in C, there is
4423 // no reason to treat it as an extension. Instead, diagnose as an error.
4424 Diag(DS.getStorageClassSpecLoc(), diag::err_mutable_nonmember);
4425 else if (!DS.isExternInLinkageSpec() && SCS != DeclSpec::SCS_typedef)
4426 Diag(DS.getStorageClassSpecLoc(), DiagID)
4427 << DeclSpec::getSpecifierName(SCS);
4430 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
4431 Diag(DS.getThreadStorageClassSpecLoc(), DiagID)
4432 << DeclSpec::getSpecifierName(TSCS);
4433 if (DS.getTypeQualifiers()) {
4434 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
4435 Diag(DS.getConstSpecLoc(), DiagID) << "const";
4436 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
4437 Diag(DS.getConstSpecLoc(), DiagID) << "volatile";
4438 // Restrict is covered above.
4439 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
4440 Diag(DS.getAtomicSpecLoc(), DiagID) << "_Atomic";
4441 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
4442 Diag(DS.getUnalignedSpecLoc(), DiagID) << "__unaligned";
4445 // Warn about ignored type attributes, for example:
4446 // __attribute__((aligned)) struct A;
4447 // Attributes should be placed after tag to apply to type declaration.
4448 if (!DS.getAttributes().empty()) {
4449 DeclSpec::TST TypeSpecType = DS.getTypeSpecType();
4450 if (TypeSpecType == DeclSpec::TST_class ||
4451 TypeSpecType == DeclSpec::TST_struct ||
4452 TypeSpecType == DeclSpec::TST_interface ||
4453 TypeSpecType == DeclSpec::TST_union ||
4454 TypeSpecType == DeclSpec::TST_enum) {
4455 for (const ParsedAttr &AL : DS.getAttributes())
4456 Diag(AL.getLoc(), diag::warn_declspec_attribute_ignored)
4457 << AL.getName() << GetDiagnosticTypeSpecifierID(TypeSpecType);
4464 /// We are trying to inject an anonymous member into the given scope;
4465 /// check if there's an existing declaration that can't be overloaded.
4467 /// \return true if this is a forbidden redeclaration
4468 static bool CheckAnonMemberRedeclaration(Sema &SemaRef,
4471 DeclarationName Name,
4472 SourceLocation NameLoc,
4474 LookupResult R(SemaRef, Name, NameLoc, Sema::LookupMemberName,
4475 Sema::ForVisibleRedeclaration);
4476 if (!SemaRef.LookupName(R, S)) return false;
4478 // Pick a representative declaration.
4479 NamedDecl *PrevDecl = R.getRepresentativeDecl()->getUnderlyingDecl();
4480 assert(PrevDecl && "Expected a non-null Decl");
4482 if (!SemaRef.isDeclInScope(PrevDecl, Owner, S))
4485 SemaRef.Diag(NameLoc, diag::err_anonymous_record_member_redecl)
4487 SemaRef.Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
4492 /// InjectAnonymousStructOrUnionMembers - Inject the members of the
4493 /// anonymous struct or union AnonRecord into the owning context Owner
4494 /// and scope S. This routine will be invoked just after we realize
4495 /// that an unnamed union or struct is actually an anonymous union or
4502 /// }; // InjectAnonymousStructOrUnionMembers called here to inject i and
4503 /// // f into the surrounding scope.x
4506 /// This routine is recursive, injecting the names of nested anonymous
4507 /// structs/unions into the owning context and scope as well.
4509 InjectAnonymousStructOrUnionMembers(Sema &SemaRef, Scope *S, DeclContext *Owner,
4510 RecordDecl *AnonRecord, AccessSpecifier AS,
4511 SmallVectorImpl<NamedDecl *> &Chaining) {
4512 bool Invalid = false;
4514 // Look every FieldDecl and IndirectFieldDecl with a name.
4515 for (auto *D : AnonRecord->decls()) {
4516 if ((isa<FieldDecl>(D) || isa<IndirectFieldDecl>(D)) &&
4517 cast<NamedDecl>(D)->getDeclName()) {
4518 ValueDecl *VD = cast<ValueDecl>(D);
4519 if (CheckAnonMemberRedeclaration(SemaRef, S, Owner, VD->getDeclName(),
4521 AnonRecord->isUnion())) {
4522 // C++ [class.union]p2:
4523 // The names of the members of an anonymous union shall be
4524 // distinct from the names of any other entity in the
4525 // scope in which the anonymous union is declared.
4528 // C++ [class.union]p2:
4529 // For the purpose of name lookup, after the anonymous union
4530 // definition, the members of the anonymous union are
4531 // considered to have been defined in the scope in which the
4532 // anonymous union is declared.
4533 unsigned OldChainingSize = Chaining.size();
4534 if (IndirectFieldDecl *IF = dyn_cast<IndirectFieldDecl>(VD))
4535 Chaining.append(IF->chain_begin(), IF->chain_end());
4537 Chaining.push_back(VD);
4539 assert(Chaining.size() >= 2);
4540 NamedDecl **NamedChain =
4541 new (SemaRef.Context)NamedDecl*[Chaining.size()];
4542 for (unsigned i = 0; i < Chaining.size(); i++)
4543 NamedChain[i] = Chaining[i];
4545 IndirectFieldDecl *IndirectField = IndirectFieldDecl::Create(
4546 SemaRef.Context, Owner, VD->getLocation(), VD->getIdentifier(),
4547 VD->getType(), {NamedChain, Chaining.size()});
4549 for (const auto *Attr : VD->attrs())
4550 IndirectField->addAttr(Attr->clone(SemaRef.Context));
4552 IndirectField->setAccess(AS);
4553 IndirectField->setImplicit();
4554 SemaRef.PushOnScopeChains(IndirectField, S);
4556 // That includes picking up the appropriate access specifier.
4557 if (AS != AS_none) IndirectField->setAccess(AS);
4559 Chaining.resize(OldChainingSize);
4567 /// StorageClassSpecToVarDeclStorageClass - Maps a DeclSpec::SCS to
4568 /// a VarDecl::StorageClass. Any error reporting is up to the caller:
4569 /// illegal input values are mapped to SC_None.
4571 StorageClassSpecToVarDeclStorageClass(const DeclSpec &DS) {
4572 DeclSpec::SCS StorageClassSpec = DS.getStorageClassSpec();
4573 assert(StorageClassSpec != DeclSpec::SCS_typedef &&
4574 "Parser allowed 'typedef' as storage class VarDecl.");
4575 switch (StorageClassSpec) {
4576 case DeclSpec::SCS_unspecified: return SC_None;
4577 case DeclSpec::SCS_extern:
4578 if (DS.isExternInLinkageSpec())
4581 case DeclSpec::SCS_static: return SC_Static;
4582 case DeclSpec::SCS_auto: return SC_Auto;
4583 case DeclSpec::SCS_register: return SC_Register;
4584 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
4585 // Illegal SCSs map to None: error reporting is up to the caller.
4586 case DeclSpec::SCS_mutable: // Fall through.
4587 case DeclSpec::SCS_typedef: return SC_None;
4589 llvm_unreachable("unknown storage class specifier");
4592 static SourceLocation findDefaultInitializer(const CXXRecordDecl *Record) {
4593 assert(Record->hasInClassInitializer());
4595 for (const auto *I : Record->decls()) {
4596 const auto *FD = dyn_cast<FieldDecl>(I);
4597 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
4598 FD = IFD->getAnonField();
4599 if (FD && FD->hasInClassInitializer())
4600 return FD->getLocation();
4603 llvm_unreachable("couldn't find in-class initializer");
4606 static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4607 SourceLocation DefaultInitLoc) {
4608 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4611 S.Diag(DefaultInitLoc, diag::err_multiple_mem_union_initialization);
4612 S.Diag(findDefaultInitializer(Parent), diag::note_previous_initializer) << 0;
4615 static void checkDuplicateDefaultInit(Sema &S, CXXRecordDecl *Parent,
4616 CXXRecordDecl *AnonUnion) {
4617 if (!Parent->isUnion() || !Parent->hasInClassInitializer())
4620 checkDuplicateDefaultInit(S, Parent, findDefaultInitializer(AnonUnion));
4623 /// BuildAnonymousStructOrUnion - Handle the declaration of an
4624 /// anonymous structure or union. Anonymous unions are a C++ feature
4625 /// (C++ [class.union]) and a C11 feature; anonymous structures
4626 /// are a C11 feature and GNU C++ extension.
4627 Decl *Sema::BuildAnonymousStructOrUnion(Scope *S, DeclSpec &DS,
4630 const PrintingPolicy &Policy) {
4631 DeclContext *Owner = Record->getDeclContext();
4633 // Diagnose whether this anonymous struct/union is an extension.
4634 if (Record->isUnion() && !getLangOpts().CPlusPlus && !getLangOpts().C11)
4635 Diag(Record->getLocation(), diag::ext_anonymous_union);
4636 else if (!Record->isUnion() && getLangOpts().CPlusPlus)
4637 Diag(Record->getLocation(), diag::ext_gnu_anonymous_struct);
4638 else if (!Record->isUnion() && !getLangOpts().C11)
4639 Diag(Record->getLocation(), diag::ext_c11_anonymous_struct);
4641 // C and C++ require different kinds of checks for anonymous
4643 bool Invalid = false;
4644 if (getLangOpts().CPlusPlus) {
4645 const char *PrevSpec = nullptr;
4647 if (Record->isUnion()) {
4648 // C++ [class.union]p6:
4649 // C++17 [class.union.anon]p2:
4650 // Anonymous unions declared in a named namespace or in the
4651 // global namespace shall be declared static.
4652 DeclContext *OwnerScope = Owner->getRedeclContext();
4653 if (DS.getStorageClassSpec() != DeclSpec::SCS_static &&
4654 (OwnerScope->isTranslationUnit() ||
4655 (OwnerScope->isNamespace() &&
4656 !cast<NamespaceDecl>(OwnerScope)->isAnonymousNamespace()))) {
4657 Diag(Record->getLocation(), diag::err_anonymous_union_not_static)
4658 << FixItHint::CreateInsertion(Record->getLocation(), "static ");
4660 // Recover by adding 'static'.
4661 DS.SetStorageClassSpec(*this, DeclSpec::SCS_static, SourceLocation(),
4662 PrevSpec, DiagID, Policy);
4664 // C++ [class.union]p6:
4665 // A storage class is not allowed in a declaration of an
4666 // anonymous union in a class scope.
4667 else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified &&
4668 isa<RecordDecl>(Owner)) {
4669 Diag(DS.getStorageClassSpecLoc(),
4670 diag::err_anonymous_union_with_storage_spec)
4671 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
4673 // Recover by removing the storage specifier.
4674 DS.SetStorageClassSpec(*this, DeclSpec::SCS_unspecified,
4676 PrevSpec, DiagID, Context.getPrintingPolicy());
4680 // Ignore const/volatile/restrict qualifiers.
4681 if (DS.getTypeQualifiers()) {
4682 if (DS.getTypeQualifiers() & DeclSpec::TQ_const)
4683 Diag(DS.getConstSpecLoc(), diag::ext_anonymous_struct_union_qualified)
4684 << Record->isUnion() << "const"
4685 << FixItHint::CreateRemoval(DS.getConstSpecLoc());
4686 if (DS.getTypeQualifiers() & DeclSpec::TQ_volatile)
4687 Diag(DS.getVolatileSpecLoc(),
4688 diag::ext_anonymous_struct_union_qualified)
4689 << Record->isUnion() << "volatile"
4690 << FixItHint::CreateRemoval(DS.getVolatileSpecLoc());
4691 if (DS.getTypeQualifiers() & DeclSpec::TQ_restrict)
4692 Diag(DS.getRestrictSpecLoc(),
4693 diag::ext_anonymous_struct_union_qualified)
4694 << Record->isUnion() << "restrict"
4695 << FixItHint::CreateRemoval(DS.getRestrictSpecLoc());
4696 if (DS.getTypeQualifiers() & DeclSpec::TQ_atomic)
4697 Diag(DS.getAtomicSpecLoc(),
4698 diag::ext_anonymous_struct_union_qualified)
4699 << Record->isUnion() << "_Atomic"
4700 << FixItHint::CreateRemoval(DS.getAtomicSpecLoc());
4701 if (DS.getTypeQualifiers() & DeclSpec::TQ_unaligned)
4702 Diag(DS.getUnalignedSpecLoc(),
4703 diag::ext_anonymous_struct_union_qualified)
4704 << Record->isUnion() << "__unaligned"
4705 << FixItHint::CreateRemoval(DS.getUnalignedSpecLoc());
4707 DS.ClearTypeQualifiers();
4710 // C++ [class.union]p2:
4711 // The member-specification of an anonymous union shall only
4712 // define non-static data members. [Note: nested types and
4713 // functions cannot be declared within an anonymous union. ]
4714 for (auto *Mem : Record->decls()) {
4715 if (auto *FD = dyn_cast<FieldDecl>(Mem)) {
4716 // C++ [class.union]p3:
4717 // An anonymous union shall not have private or protected
4718 // members (clause 11).
4719 assert(FD->getAccess() != AS_none);
4720 if (FD->getAccess() != AS_public) {
4721 Diag(FD->getLocation(), diag::err_anonymous_record_nonpublic_member)
4722 << Record->isUnion() << (FD->getAccess() == AS_protected);
4726 // C++ [class.union]p1
4727 // An object of a class with a non-trivial constructor, a non-trivial
4728 // copy constructor, a non-trivial destructor, or a non-trivial copy
4729 // assignment operator cannot be a member of a union, nor can an
4730 // array of such objects.
4731 if (CheckNontrivialField(FD))
4733 } else if (Mem->isImplicit()) {
4734 // Any implicit members are fine.
4735 } else if (isa<TagDecl>(Mem) && Mem->getDeclContext() != Record) {
4736 // This is a type that showed up in an
4737 // elaborated-type-specifier inside the anonymous struct or
4738 // union, but which actually declares a type outside of the
4739 // anonymous struct or union. It's okay.
4740 } else if (auto *MemRecord = dyn_cast<RecordDecl>(Mem)) {
4741 if (!MemRecord->isAnonymousStructOrUnion() &&
4742 MemRecord->getDeclName()) {
4743 // Visual C++ allows type definition in anonymous struct or union.
4744 if (getLangOpts().MicrosoftExt)
4745 Diag(MemRecord->getLocation(), diag::ext_anonymous_record_with_type)
4746 << Record->isUnion();
4748 // This is a nested type declaration.
4749 Diag(MemRecord->getLocation(), diag::err_anonymous_record_with_type)
4750 << Record->isUnion();
4754 // This is an anonymous type definition within another anonymous type.
4755 // This is a popular extension, provided by Plan9, MSVC and GCC, but
4756 // not part of standard C++.
4757 Diag(MemRecord->getLocation(),
4758 diag::ext_anonymous_record_with_anonymous_type)
4759 << Record->isUnion();
4761 } else if (isa<AccessSpecDecl>(Mem)) {
4762 // Any access specifier is fine.
4763 } else if (isa<StaticAssertDecl>(Mem)) {
4764 // In C++1z, static_assert declarations are also fine.
4766 // We have something that isn't a non-static data
4767 // member. Complain about it.
4768 unsigned DK = diag::err_anonymous_record_bad_member;
4769 if (isa<TypeDecl>(Mem))
4770 DK = diag::err_anonymous_record_with_type;
4771 else if (isa<FunctionDecl>(Mem))
4772 DK = diag::err_anonymous_record_with_function;
4773 else if (isa<VarDecl>(Mem))
4774 DK = diag::err_anonymous_record_with_static;
4776 // Visual C++ allows type definition in anonymous struct or union.
4777 if (getLangOpts().MicrosoftExt &&
4778 DK == diag::err_anonymous_record_with_type)
4779 Diag(Mem->getLocation(), diag::ext_anonymous_record_with_type)
4780 << Record->isUnion();
4782 Diag(Mem->getLocation(), DK) << Record->isUnion();
4788 // C++11 [class.union]p8 (DR1460):
4789 // At most one variant member of a union may have a
4790 // brace-or-equal-initializer.
4791 if (cast<CXXRecordDecl>(Record)->hasInClassInitializer() &&
4793 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Owner),
4794 cast<CXXRecordDecl>(Record));
4797 if (!Record->isUnion() && !Owner->isRecord()) {
4798 Diag(Record->getLocation(), diag::err_anonymous_struct_not_member)
4799 << getLangOpts().CPlusPlus;
4803 // Mock up a declarator.
4804 Declarator Dc(DS, DeclaratorContext::MemberContext);
4805 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
4806 assert(TInfo && "couldn't build declarator info for anonymous struct/union");
4808 // Create a declaration for this anonymous struct/union.
4809 NamedDecl *Anon = nullptr;
4810 if (RecordDecl *OwningClass = dyn_cast<RecordDecl>(Owner)) {
4811 Anon = FieldDecl::Create(Context, OwningClass,
4813 Record->getLocation(),
4814 /*IdentifierInfo=*/nullptr,
4815 Context.getTypeDeclType(Record),
4817 /*BitWidth=*/nullptr, /*Mutable=*/false,
4818 /*InitStyle=*/ICIS_NoInit);
4819 Anon->setAccess(AS);
4820 if (getLangOpts().CPlusPlus)
4821 FieldCollector->Add(cast<FieldDecl>(Anon));
4823 DeclSpec::SCS SCSpec = DS.getStorageClassSpec();
4824 StorageClass SC = StorageClassSpecToVarDeclStorageClass(DS);
4825 if (SCSpec == DeclSpec::SCS_mutable) {
4826 // mutable can only appear on non-static class members, so it's always
4828 Diag(Record->getLocation(), diag::err_mutable_nonmember);
4833 Anon = VarDecl::Create(Context, Owner,
4835 Record->getLocation(), /*IdentifierInfo=*/nullptr,
4836 Context.getTypeDeclType(Record),
4839 // Default-initialize the implicit variable. This initialization will be
4840 // trivial in almost all cases, except if a union member has an in-class
4842 // union { int n = 0; };
4843 ActOnUninitializedDecl(Anon);
4845 Anon->setImplicit();
4847 // Mark this as an anonymous struct/union type.
4848 Record->setAnonymousStructOrUnion(true);
4850 // Add the anonymous struct/union object to the current
4851 // context. We'll be referencing this object when we refer to one of
4853 Owner->addDecl(Anon);
4855 // Inject the members of the anonymous struct/union into the owning
4856 // context and into the identifier resolver chain for name lookup
4858 SmallVector<NamedDecl*, 2> Chain;
4859 Chain.push_back(Anon);
4861 if (InjectAnonymousStructOrUnionMembers(*this, S, Owner, Record, AS, Chain))
4864 if (VarDecl *NewVD = dyn_cast<VarDecl>(Anon)) {
4865 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
4866 Decl *ManglingContextDecl;
4867 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
4868 NewVD->getDeclContext(), ManglingContextDecl)) {
4869 Context.setManglingNumber(
4870 NewVD, MCtx->getManglingNumber(
4871 NewVD, getMSManglingNumber(getLangOpts(), S)));
4872 Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
4878 Anon->setInvalidDecl();
4883 /// BuildMicrosoftCAnonymousStruct - Handle the declaration of an
4884 /// Microsoft C anonymous structure.
4885 /// Ref: http://msdn.microsoft.com/en-us/library/z2cx9y4f.aspx
4888 /// struct A { int a; };
4889 /// struct B { struct A; int b; };
4896 Decl *Sema::BuildMicrosoftCAnonymousStruct(Scope *S, DeclSpec &DS,
4897 RecordDecl *Record) {
4898 assert(Record && "expected a record!");
4900 // Mock up a declarator.
4901 Declarator Dc(DS, DeclaratorContext::TypeNameContext);
4902 TypeSourceInfo *TInfo = GetTypeForDeclarator(Dc, S);
4903 assert(TInfo && "couldn't build declarator info for anonymous struct");
4905 auto *ParentDecl = cast<RecordDecl>(CurContext);
4906 QualType RecTy = Context.getTypeDeclType(Record);
4908 // Create a declaration for this anonymous struct.
4909 NamedDecl *Anon = FieldDecl::Create(Context,
4913 /*IdentifierInfo=*/nullptr,
4916 /*BitWidth=*/nullptr, /*Mutable=*/false,
4917 /*InitStyle=*/ICIS_NoInit);
4918 Anon->setImplicit();
4920 // Add the anonymous struct object to the current context.
4921 CurContext->addDecl(Anon);
4923 // Inject the members of the anonymous struct into the current
4924 // context and into the identifier resolver chain for name lookup
4926 SmallVector<NamedDecl*, 2> Chain;
4927 Chain.push_back(Anon);
4929 RecordDecl *RecordDef = Record->getDefinition();
4930 if (RequireCompleteType(Anon->getLocation(), RecTy,
4931 diag::err_field_incomplete) ||
4932 InjectAnonymousStructOrUnionMembers(*this, S, CurContext, RecordDef,
4934 Anon->setInvalidDecl();
4935 ParentDecl->setInvalidDecl();
4941 /// GetNameForDeclarator - Determine the full declaration name for the
4942 /// given Declarator.
4943 DeclarationNameInfo Sema::GetNameForDeclarator(Declarator &D) {
4944 return GetNameFromUnqualifiedId(D.getName());
4947 /// Retrieves the declaration name from a parsed unqualified-id.
4949 Sema::GetNameFromUnqualifiedId(const UnqualifiedId &Name) {
4950 DeclarationNameInfo NameInfo;
4951 NameInfo.setLoc(Name.StartLocation);
4953 switch (Name.getKind()) {
4955 case UnqualifiedIdKind::IK_ImplicitSelfParam:
4956 case UnqualifiedIdKind::IK_Identifier:
4957 NameInfo.setName(Name.Identifier);
4958 NameInfo.setLoc(Name.StartLocation);
4961 case UnqualifiedIdKind::IK_DeductionGuideName: {
4962 // C++ [temp.deduct.guide]p3:
4963 // The simple-template-id shall name a class template specialization.
4964 // The template-name shall be the same identifier as the template-name
4965 // of the simple-template-id.
4966 // These together intend to imply that the template-name shall name a
4968 // FIXME: template<typename T> struct X {};
4969 // template<typename T> using Y = X<T>;
4970 // Y(int) -> Y<int>;
4971 // satisfies these rules but does not name a class template.
4972 TemplateName TN = Name.TemplateName.get().get();
4973 auto *Template = TN.getAsTemplateDecl();
4974 if (!Template || !isa<ClassTemplateDecl>(Template)) {
4975 Diag(Name.StartLocation,
4976 diag::err_deduction_guide_name_not_class_template)
4977 << (int)getTemplateNameKindForDiagnostics(TN) << TN;
4979 Diag(Template->getLocation(), diag::note_template_decl_here);
4980 return DeclarationNameInfo();
4984 Context.DeclarationNames.getCXXDeductionGuideName(Template));
4985 NameInfo.setLoc(Name.StartLocation);
4989 case UnqualifiedIdKind::IK_OperatorFunctionId:
4990 NameInfo.setName(Context.DeclarationNames.getCXXOperatorName(
4991 Name.OperatorFunctionId.Operator));
4992 NameInfo.setLoc(Name.StartLocation);
4993 NameInfo.getInfo().CXXOperatorName.BeginOpNameLoc
4994 = Name.OperatorFunctionId.SymbolLocations[0];
4995 NameInfo.getInfo().CXXOperatorName.EndOpNameLoc
4996 = Name.EndLocation.getRawEncoding();
4999 case UnqualifiedIdKind::IK_LiteralOperatorId:
5000 NameInfo.setName(Context.DeclarationNames.getCXXLiteralOperatorName(
5002 NameInfo.setLoc(Name.StartLocation);
5003 NameInfo.setCXXLiteralOperatorNameLoc(Name.EndLocation);
5006 case UnqualifiedIdKind::IK_ConversionFunctionId: {
5007 TypeSourceInfo *TInfo;
5008 QualType Ty = GetTypeFromParser(Name.ConversionFunctionId, &TInfo);
5010 return DeclarationNameInfo();
5011 NameInfo.setName(Context.DeclarationNames.getCXXConversionFunctionName(
5012 Context.getCanonicalType(Ty)));
5013 NameInfo.setLoc(Name.StartLocation);
5014 NameInfo.setNamedTypeInfo(TInfo);
5018 case UnqualifiedIdKind::IK_ConstructorName: {
5019 TypeSourceInfo *TInfo;
5020 QualType Ty = GetTypeFromParser(Name.ConstructorName, &TInfo);
5022 return DeclarationNameInfo();
5023 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5024 Context.getCanonicalType(Ty)));
5025 NameInfo.setLoc(Name.StartLocation);
5026 NameInfo.setNamedTypeInfo(TInfo);
5030 case UnqualifiedIdKind::IK_ConstructorTemplateId: {
5031 // In well-formed code, we can only have a constructor
5032 // template-id that refers to the current context, so go there
5033 // to find the actual type being constructed.
5034 CXXRecordDecl *CurClass = dyn_cast<CXXRecordDecl>(CurContext);
5035 if (!CurClass || CurClass->getIdentifier() != Name.TemplateId->Name)
5036 return DeclarationNameInfo();
5038 // Determine the type of the class being constructed.
5039 QualType CurClassType = Context.getTypeDeclType(CurClass);
5041 // FIXME: Check two things: that the template-id names the same type as
5042 // CurClassType, and that the template-id does not occur when the name
5045 NameInfo.setName(Context.DeclarationNames.getCXXConstructorName(
5046 Context.getCanonicalType(CurClassType)));
5047 NameInfo.setLoc(Name.StartLocation);
5048 // FIXME: should we retrieve TypeSourceInfo?
5049 NameInfo.setNamedTypeInfo(nullptr);
5053 case UnqualifiedIdKind::IK_DestructorName: {
5054 TypeSourceInfo *TInfo;
5055 QualType Ty = GetTypeFromParser(Name.DestructorName, &TInfo);
5057 return DeclarationNameInfo();
5058 NameInfo.setName(Context.DeclarationNames.getCXXDestructorName(
5059 Context.getCanonicalType(Ty)));
5060 NameInfo.setLoc(Name.StartLocation);
5061 NameInfo.setNamedTypeInfo(TInfo);
5065 case UnqualifiedIdKind::IK_TemplateId: {
5066 TemplateName TName = Name.TemplateId->Template.get();
5067 SourceLocation TNameLoc = Name.TemplateId->TemplateNameLoc;
5068 return Context.getNameForTemplate(TName, TNameLoc);
5071 } // switch (Name.getKind())
5073 llvm_unreachable("Unknown name kind");
5076 static QualType getCoreType(QualType Ty) {
5078 if (Ty->isPointerType() || Ty->isReferenceType())
5079 Ty = Ty->getPointeeType();
5080 else if (Ty->isArrayType())
5081 Ty = Ty->castAsArrayTypeUnsafe()->getElementType();
5083 return Ty.withoutLocalFastQualifiers();
5087 /// hasSimilarParameters - Determine whether the C++ functions Declaration
5088 /// and Definition have "nearly" matching parameters. This heuristic is
5089 /// used to improve diagnostics in the case where an out-of-line function
5090 /// definition doesn't match any declaration within the class or namespace.
5091 /// Also sets Params to the list of indices to the parameters that differ
5092 /// between the declaration and the definition. If hasSimilarParameters
5093 /// returns true and Params is empty, then all of the parameters match.
5094 static bool hasSimilarParameters(ASTContext &Context,
5095 FunctionDecl *Declaration,
5096 FunctionDecl *Definition,
5097 SmallVectorImpl<unsigned> &Params) {
5099 if (Declaration->param_size() != Definition->param_size())
5101 for (unsigned Idx = 0; Idx < Declaration->param_size(); ++Idx) {
5102 QualType DeclParamTy = Declaration->getParamDecl(Idx)->getType();
5103 QualType DefParamTy = Definition->getParamDecl(Idx)->getType();
5105 // The parameter types are identical
5106 if (Context.hasSameType(DefParamTy, DeclParamTy))
5109 QualType DeclParamBaseTy = getCoreType(DeclParamTy);
5110 QualType DefParamBaseTy = getCoreType(DefParamTy);
5111 const IdentifierInfo *DeclTyName = DeclParamBaseTy.getBaseTypeIdentifier();
5112 const IdentifierInfo *DefTyName = DefParamBaseTy.getBaseTypeIdentifier();
5114 if (Context.hasSameUnqualifiedType(DeclParamBaseTy, DefParamBaseTy) ||
5115 (DeclTyName && DeclTyName == DefTyName))
5116 Params.push_back(Idx);
5117 else // The two parameters aren't even close
5124 /// NeedsRebuildingInCurrentInstantiation - Checks whether the given
5125 /// declarator needs to be rebuilt in the current instantiation.
5126 /// Any bits of declarator which appear before the name are valid for
5127 /// consideration here. That's specifically the type in the decl spec
5128 /// and the base type in any member-pointer chunks.
5129 static bool RebuildDeclaratorInCurrentInstantiation(Sema &S, Declarator &D,
5130 DeclarationName Name) {
5131 // The types we specifically need to rebuild are:
5132 // - typenames, typeofs, and decltypes
5133 // - types which will become injected class names
5134 // Of course, we also need to rebuild any type referencing such a
5135 // type. It's safest to just say "dependent", but we call out a
5138 DeclSpec &DS = D.getMutableDeclSpec();
5139 switch (DS.getTypeSpecType()) {
5140 case DeclSpec::TST_typename:
5141 case DeclSpec::TST_typeofType:
5142 case DeclSpec::TST_underlyingType:
5143 case DeclSpec::TST_atomic: {
5144 // Grab the type from the parser.
5145 TypeSourceInfo *TSI = nullptr;
5146 QualType T = S.GetTypeFromParser(DS.getRepAsType(), &TSI);
5147 if (T.isNull() || !T->isDependentType()) break;
5149 // Make sure there's a type source info. This isn't really much
5150 // of a waste; most dependent types should have type source info
5151 // attached already.
5153 TSI = S.Context.getTrivialTypeSourceInfo(T, DS.getTypeSpecTypeLoc());
5155 // Rebuild the type in the current instantiation.
5156 TSI = S.RebuildTypeInCurrentInstantiation(TSI, D.getIdentifierLoc(), Name);
5157 if (!TSI) return true;
5159 // Store the new type back in the decl spec.
5160 ParsedType LocType = S.CreateParsedType(TSI->getType(), TSI);
5161 DS.UpdateTypeRep(LocType);
5165 case DeclSpec::TST_decltype:
5166 case DeclSpec::TST_typeofExpr: {
5167 Expr *E = DS.getRepAsExpr();
5168 ExprResult Result = S.RebuildExprInCurrentInstantiation(E);
5169 if (Result.isInvalid()) return true;
5170 DS.UpdateExprRep(Result.get());
5175 // Nothing to do for these decl specs.
5179 // It doesn't matter what order we do this in.
5180 for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
5181 DeclaratorChunk &Chunk = D.getTypeObject(I);
5183 // The only type information in the declarator which can come
5184 // before the declaration name is the base type of a member
5186 if (Chunk.Kind != DeclaratorChunk::MemberPointer)
5189 // Rebuild the scope specifier in-place.
5190 CXXScopeSpec &SS = Chunk.Mem.Scope();
5191 if (S.RebuildNestedNameSpecifierInCurrentInstantiation(SS))
5198 Decl *Sema::ActOnDeclarator(Scope *S, Declarator &D) {
5199 D.setFunctionDefinitionKind(FDK_Declaration);
5200 Decl *Dcl = HandleDeclarator(S, D, MultiTemplateParamsArg());
5202 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer() &&
5203 Dcl && Dcl->getDeclContext()->isFileContext())
5204 Dcl->setTopLevelDeclInObjCContainer();
5206 if (getLangOpts().OpenCL)
5207 setCurrentOpenCLExtensionForDecl(Dcl);
5212 /// DiagnoseClassNameShadow - Implement C++ [class.mem]p13:
5213 /// If T is the name of a class, then each of the following shall have a
5214 /// name different from T:
5215 /// - every static data member of class T;
5216 /// - every member function of class T
5217 /// - every member of class T that is itself a type;
5218 /// \returns true if the declaration name violates these rules.
5219 bool Sema::DiagnoseClassNameShadow(DeclContext *DC,
5220 DeclarationNameInfo NameInfo) {
5221 DeclarationName Name = NameInfo.getName();
5223 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(DC);
5224 while (Record && Record->isAnonymousStructOrUnion())
5225 Record = dyn_cast<CXXRecordDecl>(Record->getParent());
5226 if (Record && Record->getIdentifier() && Record->getDeclName() == Name) {
5227 Diag(NameInfo.getLoc(), diag::err_member_name_of_class) << Name;
5234 /// Diagnose a declaration whose declarator-id has the given
5235 /// nested-name-specifier.
5237 /// \param SS The nested-name-specifier of the declarator-id.
5239 /// \param DC The declaration context to which the nested-name-specifier
5242 /// \param Name The name of the entity being declared.
5244 /// \param Loc The location of the name of the entity being declared.
5246 /// \param IsTemplateId Whether the name is a (simple-)template-id, and thus
5247 /// we're declaring an explicit / partial specialization / instantiation.
5249 /// \returns true if we cannot safely recover from this error, false otherwise.
5250 bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
5251 DeclarationName Name,
5252 SourceLocation Loc, bool IsTemplateId) {
5253 DeclContext *Cur = CurContext;
5254 while (isa<LinkageSpecDecl>(Cur) || isa<CapturedDecl>(Cur))
5255 Cur = Cur->getParent();
5257 // If the user provided a superfluous scope specifier that refers back to the
5258 // class in which the entity is already declared, diagnose and ignore it.
5264 // Note, it was once ill-formed to give redundant qualification in all
5265 // contexts, but that rule was removed by DR482.
5266 if (Cur->Equals(DC)) {
5267 if (Cur->isRecord()) {
5268 Diag(Loc, LangOpts.MicrosoftExt ? diag::warn_member_extra_qualification
5269 : diag::err_member_extra_qualification)
5270 << Name << FixItHint::CreateRemoval(SS.getRange());
5273 Diag(Loc, diag::warn_namespace_member_extra_qualification) << Name;
5278 // Check whether the qualifying scope encloses the scope of the original
5279 // declaration. For a template-id, we perform the checks in
5280 // CheckTemplateSpecializationScope.
5281 if (!Cur->Encloses(DC) && !IsTemplateId) {
5282 if (Cur->isRecord())
5283 Diag(Loc, diag::err_member_qualification)
5284 << Name << SS.getRange();
5285 else if (isa<TranslationUnitDecl>(DC))
5286 Diag(Loc, diag::err_invalid_declarator_global_scope)
5287 << Name << SS.getRange();
5288 else if (isa<FunctionDecl>(Cur))
5289 Diag(Loc, diag::err_invalid_declarator_in_function)
5290 << Name << SS.getRange();
5291 else if (isa<BlockDecl>(Cur))
5292 Diag(Loc, diag::err_invalid_declarator_in_block)
5293 << Name << SS.getRange();
5295 Diag(Loc, diag::err_invalid_declarator_scope)
5296 << Name << cast<NamedDecl>(Cur) << cast<NamedDecl>(DC) << SS.getRange();
5301 if (Cur->isRecord()) {
5302 // Cannot qualify members within a class.
5303 Diag(Loc, diag::err_member_qualification)
5304 << Name << SS.getRange();
5307 // C++ constructors and destructors with incorrect scopes can break
5308 // our AST invariants by having the wrong underlying types. If
5309 // that's the case, then drop this declaration entirely.
5310 if ((Name.getNameKind() == DeclarationName::CXXConstructorName ||
5311 Name.getNameKind() == DeclarationName::CXXDestructorName) &&
5312 !Context.hasSameType(Name.getCXXNameType(),
5313 Context.getTypeDeclType(cast<CXXRecordDecl>(Cur))))
5319 // C++11 [dcl.meaning]p1:
5320 // [...] "The nested-name-specifier of the qualified declarator-id shall
5321 // not begin with a decltype-specifer"
5322 NestedNameSpecifierLoc SpecLoc(SS.getScopeRep(), SS.location_data());
5323 while (SpecLoc.getPrefix())
5324 SpecLoc = SpecLoc.getPrefix();
5325 if (dyn_cast_or_null<DecltypeType>(
5326 SpecLoc.getNestedNameSpecifier()->getAsType()))
5327 Diag(Loc, diag::err_decltype_in_declarator)
5328 << SpecLoc.getTypeLoc().getSourceRange();
5333 NamedDecl *Sema::HandleDeclarator(Scope *S, Declarator &D,
5334 MultiTemplateParamsArg TemplateParamLists) {
5335 // TODO: consider using NameInfo for diagnostic.
5336 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
5337 DeclarationName Name = NameInfo.getName();
5339 // All of these full declarators require an identifier. If it doesn't have
5340 // one, the ParsedFreeStandingDeclSpec action should be used.
5341 if (D.isDecompositionDeclarator()) {
5342 return ActOnDecompositionDeclarator(S, D, TemplateParamLists);
5344 if (!D.isInvalidType()) // Reject this if we think it is valid.
5345 Diag(D.getDeclSpec().getLocStart(),
5346 diag::err_declarator_need_ident)
5347 << D.getDeclSpec().getSourceRange() << D.getSourceRange();
5349 } else if (DiagnoseUnexpandedParameterPack(NameInfo, UPPC_DeclarationType))
5352 // The scope passed in may not be a decl scope. Zip up the scope tree until
5353 // we find one that is.
5354 while ((S->getFlags() & Scope::DeclScope) == 0 ||
5355 (S->getFlags() & Scope::TemplateParamScope) != 0)
5358 DeclContext *DC = CurContext;
5359 if (D.getCXXScopeSpec().isInvalid())
5361 else if (D.getCXXScopeSpec().isSet()) {
5362 if (DiagnoseUnexpandedParameterPack(D.getCXXScopeSpec(),
5363 UPPC_DeclarationQualifier))
5366 bool EnteringContext = !D.getDeclSpec().isFriendSpecified();
5367 DC = computeDeclContext(D.getCXXScopeSpec(), EnteringContext);
5368 if (!DC || isa<EnumDecl>(DC)) {
5369 // If we could not compute the declaration context, it's because the
5370 // declaration context is dependent but does not refer to a class,
5371 // class template, or class template partial specialization. Complain
5372 // and return early, to avoid the coming semantic disaster.
5373 Diag(D.getIdentifierLoc(),
5374 diag::err_template_qualified_declarator_no_match)
5375 << D.getCXXScopeSpec().getScopeRep()
5376 << D.getCXXScopeSpec().getRange();
5379 bool IsDependentContext = DC->isDependentContext();
5381 if (!IsDependentContext &&
5382 RequireCompleteDeclContext(D.getCXXScopeSpec(), DC))
5385 // If a class is incomplete, do not parse entities inside it.
5386 if (isa<CXXRecordDecl>(DC) && !cast<CXXRecordDecl>(DC)->hasDefinition()) {
5387 Diag(D.getIdentifierLoc(),
5388 diag::err_member_def_undefined_record)
5389 << Name << DC << D.getCXXScopeSpec().getRange();
5392 if (!D.getDeclSpec().isFriendSpecified()) {
5393 if (diagnoseQualifiedDeclaration(
5394 D.getCXXScopeSpec(), DC, Name, D.getIdentifierLoc(),
5395 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId)) {
5403 // Check whether we need to rebuild the type of the given
5404 // declaration in the current instantiation.
5405 if (EnteringContext && IsDependentContext &&
5406 TemplateParamLists.size() != 0) {
5407 ContextRAII SavedContext(*this, DC);
5408 if (RebuildDeclaratorInCurrentInstantiation(*this, D, Name))
5413 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
5414 QualType R = TInfo->getType();
5416 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
5417 UPPC_DeclarationType))
5420 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
5421 forRedeclarationInCurContext());
5423 // See if this is a redefinition of a variable in the same scope.
5424 if (!D.getCXXScopeSpec().isSet()) {
5425 bool IsLinkageLookup = false;
5426 bool CreateBuiltins = false;
5428 // If the declaration we're planning to build will be a function
5429 // or object with linkage, then look for another declaration with
5430 // linkage (C99 6.2.2p4-5 and C++ [basic.link]p6).
5432 // If the declaration we're planning to build will be declared with
5433 // external linkage in the translation unit, create any builtin with
5435 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
5437 else if (CurContext->isFunctionOrMethod() &&
5438 (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_extern ||
5439 R->isFunctionType())) {
5440 IsLinkageLookup = true;
5442 CurContext->getEnclosingNamespaceContext()->isTranslationUnit();
5443 } else if (CurContext->getRedeclContext()->isTranslationUnit() &&
5444 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static)
5445 CreateBuiltins = true;
5447 if (IsLinkageLookup) {
5448 Previous.clear(LookupRedeclarationWithLinkage);
5449 Previous.setRedeclarationKind(ForExternalRedeclaration);
5452 LookupName(Previous, S, CreateBuiltins);
5453 } else { // Something like "int foo::x;"
5454 LookupQualifiedName(Previous, DC);
5456 // C++ [dcl.meaning]p1:
5457 // When the declarator-id is qualified, the declaration shall refer to a
5458 // previously declared member of the class or namespace to which the
5459 // qualifier refers (or, in the case of a namespace, of an element of the
5460 // inline namespace set of that namespace (7.3.1)) or to a specialization
5463 // Note that we already checked the context above, and that we do not have
5464 // enough information to make sure that Previous contains the declaration
5465 // we want to match. For example, given:
5472 // void X::f(int) { } // ill-formed
5474 // In this case, Previous will point to the overload set
5475 // containing the two f's declared in X, but neither of them
5478 // C++ [dcl.meaning]p1:
5479 // [...] the member shall not merely have been introduced by a
5480 // using-declaration in the scope of the class or namespace nominated by
5481 // the nested-name-specifier of the declarator-id.
5482 RemoveUsingDecls(Previous);
5485 if (Previous.isSingleResult() &&
5486 Previous.getFoundDecl()->isTemplateParameter()) {
5487 // Maybe we will complain about the shadowed template parameter.
5488 if (!D.isInvalidType())
5489 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
5490 Previous.getFoundDecl());
5492 // Just pretend that we didn't see the previous declaration.
5496 if (!R->isFunctionType() && DiagnoseClassNameShadow(DC, NameInfo))
5497 // Forget that the previous declaration is the injected-class-name.
5500 // In C++, the previous declaration we find might be a tag type
5501 // (class or enum). In this case, the new declaration will hide the
5502 // tag type. Note that this applies to functions, function templates, and
5503 // variables, but not to typedefs (C++ [dcl.typedef]p4) or variable templates.
5504 if (Previous.isSingleTagDecl() &&
5505 D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
5506 (TemplateParamLists.size() == 0 || R->isFunctionType()))
5509 // Check that there are no default arguments other than in the parameters
5510 // of a function declaration (C++ only).
5511 if (getLangOpts().CPlusPlus)
5512 CheckExtraCXXDefaultArguments(D);
5516 bool AddToScope = true;
5517 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
5518 if (TemplateParamLists.size()) {
5519 Diag(D.getIdentifierLoc(), diag::err_template_typedef);
5523 New = ActOnTypedefDeclarator(S, D, DC, TInfo, Previous);
5524 } else if (R->isFunctionType()) {
5525 New = ActOnFunctionDeclarator(S, D, DC, TInfo, Previous,
5529 New = ActOnVariableDeclarator(S, D, DC, TInfo, Previous, TemplateParamLists,
5536 // If this has an identifier and is not a function template specialization,
5537 // add it to the scope stack.
5538 if (New->getDeclName() && AddToScope) {
5539 // Only make a locally-scoped extern declaration visible if it is the first
5540 // declaration of this entity. Qualified lookup for such an entity should
5541 // only find this declaration if there is no visible declaration of it.
5542 bool AddToContext = !D.isRedeclaration() || !New->isLocalExternDecl();
5543 PushOnScopeChains(New, S, AddToContext);
5545 CurContext->addHiddenDecl(New);
5548 if (isInOpenMPDeclareTargetContext())
5549 checkDeclIsAllowedInOpenMPTarget(nullptr, New);
5554 /// Helper method to turn variable array types into constant array
5555 /// types in certain situations which would otherwise be errors (for
5556 /// GCC compatibility).
5557 static QualType TryToFixInvalidVariablyModifiedType(QualType T,
5558 ASTContext &Context,
5559 bool &SizeIsNegative,
5560 llvm::APSInt &Oversized) {
5561 // This method tries to turn a variable array into a constant
5562 // array even when the size isn't an ICE. This is necessary
5563 // for compatibility with code that depends on gcc's buggy
5564 // constant expression folding, like struct {char x[(int)(char*)2];}
5565 SizeIsNegative = false;
5568 if (T->isDependentType())
5571 QualifierCollector Qs;
5572 const Type *Ty = Qs.strip(T);
5574 if (const PointerType* PTy = dyn_cast<PointerType>(Ty)) {
5575 QualType Pointee = PTy->getPointeeType();
5576 QualType FixedType =
5577 TryToFixInvalidVariablyModifiedType(Pointee, Context, SizeIsNegative,
5579 if (FixedType.isNull()) return FixedType;
5580 FixedType = Context.getPointerType(FixedType);
5581 return Qs.apply(Context, FixedType);
5583 if (const ParenType* PTy = dyn_cast<ParenType>(Ty)) {
5584 QualType Inner = PTy->getInnerType();
5585 QualType FixedType =
5586 TryToFixInvalidVariablyModifiedType(Inner, Context, SizeIsNegative,
5588 if (FixedType.isNull()) return FixedType;
5589 FixedType = Context.getParenType(FixedType);
5590 return Qs.apply(Context, FixedType);
5593 const VariableArrayType* VLATy = dyn_cast<VariableArrayType>(T);
5596 // FIXME: We should probably handle this case
5597 if (VLATy->getElementType()->isVariablyModifiedType())
5601 if (!VLATy->getSizeExpr() ||
5602 !VLATy->getSizeExpr()->EvaluateAsInt(Res, Context))
5605 // Check whether the array size is negative.
5606 if (Res.isSigned() && Res.isNegative()) {
5607 SizeIsNegative = true;
5611 // Check whether the array is too large to be addressed.
5612 unsigned ActiveSizeBits
5613 = ConstantArrayType::getNumAddressingBits(Context, VLATy->getElementType(),
5615 if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
5620 return Context.getConstantArrayType(VLATy->getElementType(),
5621 Res, ArrayType::Normal, 0);
5625 FixInvalidVariablyModifiedTypeLoc(TypeLoc SrcTL, TypeLoc DstTL) {
5626 SrcTL = SrcTL.getUnqualifiedLoc();
5627 DstTL = DstTL.getUnqualifiedLoc();
5628 if (PointerTypeLoc SrcPTL = SrcTL.getAs<PointerTypeLoc>()) {
5629 PointerTypeLoc DstPTL = DstTL.castAs<PointerTypeLoc>();
5630 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getPointeeLoc(),
5631 DstPTL.getPointeeLoc());
5632 DstPTL.setStarLoc(SrcPTL.getStarLoc());
5635 if (ParenTypeLoc SrcPTL = SrcTL.getAs<ParenTypeLoc>()) {
5636 ParenTypeLoc DstPTL = DstTL.castAs<ParenTypeLoc>();
5637 FixInvalidVariablyModifiedTypeLoc(SrcPTL.getInnerLoc(),
5638 DstPTL.getInnerLoc());
5639 DstPTL.setLParenLoc(SrcPTL.getLParenLoc());
5640 DstPTL.setRParenLoc(SrcPTL.getRParenLoc());
5643 ArrayTypeLoc SrcATL = SrcTL.castAs<ArrayTypeLoc>();
5644 ArrayTypeLoc DstATL = DstTL.castAs<ArrayTypeLoc>();
5645 TypeLoc SrcElemTL = SrcATL.getElementLoc();
5646 TypeLoc DstElemTL = DstATL.getElementLoc();
5647 DstElemTL.initializeFullCopy(SrcElemTL);
5648 DstATL.setLBracketLoc(SrcATL.getLBracketLoc());
5649 DstATL.setSizeExpr(SrcATL.getSizeExpr());
5650 DstATL.setRBracketLoc(SrcATL.getRBracketLoc());
5653 /// Helper method to turn variable array types into constant array
5654 /// types in certain situations which would otherwise be errors (for
5655 /// GCC compatibility).
5656 static TypeSourceInfo*
5657 TryToFixInvalidVariablyModifiedTypeSourceInfo(TypeSourceInfo *TInfo,
5658 ASTContext &Context,
5659 bool &SizeIsNegative,
5660 llvm::APSInt &Oversized) {
5662 = TryToFixInvalidVariablyModifiedType(TInfo->getType(), Context,
5663 SizeIsNegative, Oversized);
5664 if (FixedTy.isNull())
5666 TypeSourceInfo *FixedTInfo = Context.getTrivialTypeSourceInfo(FixedTy);
5667 FixInvalidVariablyModifiedTypeLoc(TInfo->getTypeLoc(),
5668 FixedTInfo->getTypeLoc());
5672 /// Register the given locally-scoped extern "C" declaration so
5673 /// that it can be found later for redeclarations. We include any extern "C"
5674 /// declaration that is not visible in the translation unit here, not just
5675 /// function-scope declarations.
5677 Sema::RegisterLocallyScopedExternCDecl(NamedDecl *ND, Scope *S) {
5678 if (!getLangOpts().CPlusPlus &&
5679 ND->getLexicalDeclContext()->getRedeclContext()->isTranslationUnit())
5680 // Don't need to track declarations in the TU in C.
5683 // Note that we have a locally-scoped external with this name.
5684 Context.getExternCContextDecl()->makeDeclVisibleInContext(ND);
5687 NamedDecl *Sema::findLocallyScopedExternCDecl(DeclarationName Name) {
5688 // FIXME: We can have multiple results via __attribute__((overloadable)).
5689 auto Result = Context.getExternCContextDecl()->lookup(Name);
5690 return Result.empty() ? nullptr : *Result.begin();
5693 /// Diagnose function specifiers on a declaration of an identifier that
5694 /// does not identify a function.
5695 void Sema::DiagnoseFunctionSpecifiers(const DeclSpec &DS) {
5696 // FIXME: We should probably indicate the identifier in question to avoid
5697 // confusion for constructs like "virtual int a(), b;"
5698 if (DS.isVirtualSpecified())
5699 Diag(DS.getVirtualSpecLoc(),
5700 diag::err_virtual_non_function);
5702 if (DS.isExplicitSpecified())
5703 Diag(DS.getExplicitSpecLoc(),
5704 diag::err_explicit_non_function);
5706 if (DS.isNoreturnSpecified())
5707 Diag(DS.getNoreturnSpecLoc(),
5708 diag::err_noreturn_non_function);
5712 Sema::ActOnTypedefDeclarator(Scope* S, Declarator& D, DeclContext* DC,
5713 TypeSourceInfo *TInfo, LookupResult &Previous) {
5714 // Typedef declarators cannot be qualified (C++ [dcl.meaning]p1).
5715 if (D.getCXXScopeSpec().isSet()) {
5716 Diag(D.getIdentifierLoc(), diag::err_qualified_typedef_declarator)
5717 << D.getCXXScopeSpec().getRange();
5719 // Pretend we didn't see the scope specifier.
5724 DiagnoseFunctionSpecifiers(D.getDeclSpec());
5726 if (D.getDeclSpec().isInlineSpecified())
5727 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
5728 << getLangOpts().CPlusPlus17;
5729 if (D.getDeclSpec().isConstexprSpecified())
5730 Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_invalid_constexpr)
5733 if (D.getName().Kind != UnqualifiedIdKind::IK_Identifier) {
5734 if (D.getName().Kind == UnqualifiedIdKind::IK_DeductionGuideName)
5735 Diag(D.getName().StartLocation,
5736 diag::err_deduction_guide_invalid_specifier)
5739 Diag(D.getName().StartLocation, diag::err_typedef_not_identifier)
5740 << D.getName().getSourceRange();
5744 TypedefDecl *NewTD = ParseTypedefDecl(S, D, TInfo->getType(), TInfo);
5745 if (!NewTD) return nullptr;
5747 // Handle attributes prior to checking for duplicates in MergeVarDecl
5748 ProcessDeclAttributes(S, NewTD, D);
5750 CheckTypedefForVariablyModifiedType(S, NewTD);
5752 bool Redeclaration = D.isRedeclaration();
5753 NamedDecl *ND = ActOnTypedefNameDecl(S, DC, NewTD, Previous, Redeclaration);
5754 D.setRedeclaration(Redeclaration);
5759 Sema::CheckTypedefForVariablyModifiedType(Scope *S, TypedefNameDecl *NewTD) {
5760 // C99 6.7.7p2: If a typedef name specifies a variably modified type
5761 // then it shall have block scope.
5762 // Note that variably modified types must be fixed before merging the decl so
5763 // that redeclarations will match.
5764 TypeSourceInfo *TInfo = NewTD->getTypeSourceInfo();
5765 QualType T = TInfo->getType();
5766 if (T->isVariablyModifiedType()) {
5767 setFunctionHasBranchProtectedScope();
5769 if (S->getFnParent() == nullptr) {
5770 bool SizeIsNegative;
5771 llvm::APSInt Oversized;
5772 TypeSourceInfo *FixedTInfo =
5773 TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
5777 Diag(NewTD->getLocation(), diag::warn_illegal_constant_array_size);
5778 NewTD->setTypeSourceInfo(FixedTInfo);
5781 Diag(NewTD->getLocation(), diag::err_typecheck_negative_array_size);
5782 else if (T->isVariableArrayType())
5783 Diag(NewTD->getLocation(), diag::err_vla_decl_in_file_scope);
5784 else if (Oversized.getBoolValue())
5785 Diag(NewTD->getLocation(), diag::err_array_too_large)
5786 << Oversized.toString(10);
5788 Diag(NewTD->getLocation(), diag::err_vm_decl_in_file_scope);
5789 NewTD->setInvalidDecl();
5795 /// ActOnTypedefNameDecl - Perform semantic checking for a declaration which
5796 /// declares a typedef-name, either using the 'typedef' type specifier or via
5797 /// a C++0x [dcl.typedef]p2 alias-declaration: 'using T = A;'.
5799 Sema::ActOnTypedefNameDecl(Scope *S, DeclContext *DC, TypedefNameDecl *NewTD,
5800 LookupResult &Previous, bool &Redeclaration) {
5802 // Find the shadowed declaration before filtering for scope.
5803 NamedDecl *ShadowedDecl = getShadowedDeclaration(NewTD, Previous);
5805 // Merge the decl with the existing one if appropriate. If the decl is
5806 // in an outer scope, it isn't the same thing.
5807 FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage*/false,
5808 /*AllowInlineNamespace*/false);
5809 filterNonConflictingPreviousTypedefDecls(*this, NewTD, Previous);
5810 if (!Previous.empty()) {
5811 Redeclaration = true;
5812 MergeTypedefNameDecl(S, NewTD, Previous);
5815 if (ShadowedDecl && !Redeclaration)
5816 CheckShadow(NewTD, ShadowedDecl, Previous);
5818 // If this is the C FILE type, notify the AST context.
5819 if (IdentifierInfo *II = NewTD->getIdentifier())
5820 if (!NewTD->isInvalidDecl() &&
5821 NewTD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
5822 if (II->isStr("FILE"))
5823 Context.setFILEDecl(NewTD);
5824 else if (II->isStr("jmp_buf"))
5825 Context.setjmp_bufDecl(NewTD);
5826 else if (II->isStr("sigjmp_buf"))
5827 Context.setsigjmp_bufDecl(NewTD);
5828 else if (II->isStr("ucontext_t"))
5829 Context.setucontext_tDecl(NewTD);
5835 /// Determines whether the given declaration is an out-of-scope
5836 /// previous declaration.
5838 /// This routine should be invoked when name lookup has found a
5839 /// previous declaration (PrevDecl) that is not in the scope where a
5840 /// new declaration by the same name is being introduced. If the new
5841 /// declaration occurs in a local scope, previous declarations with
5842 /// linkage may still be considered previous declarations (C99
5843 /// 6.2.2p4-5, C++ [basic.link]p6).
5845 /// \param PrevDecl the previous declaration found by name
5848 /// \param DC the context in which the new declaration is being
5851 /// \returns true if PrevDecl is an out-of-scope previous declaration
5852 /// for a new delcaration with the same name.
5854 isOutOfScopePreviousDeclaration(NamedDecl *PrevDecl, DeclContext *DC,
5855 ASTContext &Context) {
5859 if (!PrevDecl->hasLinkage())
5862 if (Context.getLangOpts().CPlusPlus) {
5863 // C++ [basic.link]p6:
5864 // If there is a visible declaration of an entity with linkage
5865 // having the same name and type, ignoring entities declared
5866 // outside the innermost enclosing namespace scope, the block
5867 // scope declaration declares that same entity and receives the
5868 // linkage of the previous declaration.
5869 DeclContext *OuterContext = DC->getRedeclContext();
5870 if (!OuterContext->isFunctionOrMethod())
5871 // This rule only applies to block-scope declarations.
5874 DeclContext *PrevOuterContext = PrevDecl->getDeclContext();
5875 if (PrevOuterContext->isRecord())
5876 // We found a member function: ignore it.
5879 // Find the innermost enclosing namespace for the new and
5880 // previous declarations.
5881 OuterContext = OuterContext->getEnclosingNamespaceContext();
5882 PrevOuterContext = PrevOuterContext->getEnclosingNamespaceContext();
5884 // The previous declaration is in a different namespace, so it
5885 // isn't the same function.
5886 if (!OuterContext->Equals(PrevOuterContext))
5893 static void SetNestedNameSpecifier(DeclaratorDecl *DD, Declarator &D) {
5894 CXXScopeSpec &SS = D.getCXXScopeSpec();
5895 if (!SS.isSet()) return;
5896 DD->setQualifierInfo(SS.getWithLocInContext(DD->getASTContext()));
5899 bool Sema::inferObjCARCLifetime(ValueDecl *decl) {
5900 QualType type = decl->getType();
5901 Qualifiers::ObjCLifetime lifetime = type.getObjCLifetime();
5902 if (lifetime == Qualifiers::OCL_Autoreleasing) {
5903 // Various kinds of declaration aren't allowed to be __autoreleasing.
5904 unsigned kind = -1U;
5905 if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
5906 if (var->hasAttr<BlocksAttr>())
5907 kind = 0; // __block
5908 else if (!var->hasLocalStorage())
5910 } else if (isa<ObjCIvarDecl>(decl)) {
5912 } else if (isa<FieldDecl>(decl)) {
5917 Diag(decl->getLocation(), diag::err_arc_autoreleasing_var)
5920 } else if (lifetime == Qualifiers::OCL_None) {
5921 // Try to infer lifetime.
5922 if (!type->isObjCLifetimeType())
5925 lifetime = type->getObjCARCImplicitLifetime();
5926 type = Context.getLifetimeQualifiedType(type, lifetime);
5927 decl->setType(type);
5930 if (VarDecl *var = dyn_cast<VarDecl>(decl)) {
5931 // Thread-local variables cannot have lifetime.
5932 if (lifetime && lifetime != Qualifiers::OCL_ExplicitNone &&
5933 var->getTLSKind()) {
5934 Diag(var->getLocation(), diag::err_arc_thread_ownership)
5943 static void checkAttributesAfterMerging(Sema &S, NamedDecl &ND) {
5944 // Ensure that an auto decl is deduced otherwise the checks below might cache
5945 // the wrong linkage.
5946 assert(S.ParsingInitForAutoVars.count(&ND) == 0);
5948 // 'weak' only applies to declarations with external linkage.
5949 if (WeakAttr *Attr = ND.getAttr<WeakAttr>()) {
5950 if (!ND.isExternallyVisible()) {
5951 S.Diag(Attr->getLocation(), diag::err_attribute_weak_static);
5952 ND.dropAttr<WeakAttr>();
5955 if (WeakRefAttr *Attr = ND.getAttr<WeakRefAttr>()) {
5956 if (ND.isExternallyVisible()) {
5957 S.Diag(Attr->getLocation(), diag::err_attribute_weakref_not_static);
5958 ND.dropAttr<WeakRefAttr>();
5959 ND.dropAttr<AliasAttr>();
5963 if (auto *VD = dyn_cast<VarDecl>(&ND)) {
5964 if (VD->hasInit()) {
5965 if (const auto *Attr = VD->getAttr<AliasAttr>()) {
5966 assert(VD->isThisDeclarationADefinition() &&
5967 !VD->isExternallyVisible() && "Broken AliasAttr handled late!");
5968 S.Diag(Attr->getLocation(), diag::err_alias_is_definition) << VD << 0;
5969 VD->dropAttr<AliasAttr>();
5974 // 'selectany' only applies to externally visible variable declarations.
5975 // It does not apply to functions.
5976 if (SelectAnyAttr *Attr = ND.getAttr<SelectAnyAttr>()) {
5977 if (isa<FunctionDecl>(ND) || !ND.isExternallyVisible()) {
5978 S.Diag(Attr->getLocation(),
5979 diag::err_attribute_selectany_non_extern_data);
5980 ND.dropAttr<SelectAnyAttr>();
5984 if (const InheritableAttr *Attr = getDLLAttr(&ND)) {
5985 // dll attributes require external linkage. Static locals may have external
5986 // linkage but still cannot be explicitly imported or exported.
5987 auto *VD = dyn_cast<VarDecl>(&ND);
5988 if (!ND.isExternallyVisible() || (VD && VD->isStaticLocal())) {
5989 S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
5991 ND.setInvalidDecl();
5995 // Virtual functions cannot be marked as 'notail'.
5996 if (auto *Attr = ND.getAttr<NotTailCalledAttr>())
5997 if (auto *MD = dyn_cast<CXXMethodDecl>(&ND))
5998 if (MD->isVirtual()) {
5999 S.Diag(ND.getLocation(),
6000 diag::err_invalid_attribute_on_virtual_function)
6002 ND.dropAttr<NotTailCalledAttr>();
6005 // Check the attributes on the function type, if any.
6006 if (const auto *FD = dyn_cast<FunctionDecl>(&ND)) {
6007 // Don't declare this variable in the second operand of the for-statement;
6008 // GCC miscompiles that by ending its lifetime before evaluating the
6009 // third operand. See gcc.gnu.org/PR86769.
6010 AttributedTypeLoc ATL;
6011 for (TypeLoc TL = FD->getTypeSourceInfo()->getTypeLoc();
6012 (ATL = TL.getAsAdjusted<AttributedTypeLoc>());
6013 TL = ATL.getModifiedLoc()) {
6014 // The [[lifetimebound]] attribute can be applied to the implicit object
6015 // parameter of a non-static member function (other than a ctor or dtor)
6016 // by applying it to the function type.
6017 if (ATL.getAttrKind() == AttributedType::attr_lifetimebound) {
6018 const auto *MD = dyn_cast<CXXMethodDecl>(FD);
6019 if (!MD || MD->isStatic()) {
6020 S.Diag(ATL.getAttrNameLoc(), diag::err_lifetimebound_no_object_param)
6021 << !MD << ATL.getLocalSourceRange();
6022 } else if (isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD)) {
6023 S.Diag(ATL.getAttrNameLoc(), diag::err_lifetimebound_ctor_dtor)
6024 << isa<CXXDestructorDecl>(MD) << ATL.getLocalSourceRange();
6031 static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,
6033 bool IsSpecialization,
6034 bool IsDefinition) {
6035 if (OldDecl->isInvalidDecl() || NewDecl->isInvalidDecl())
6038 bool IsTemplate = false;
6039 if (TemplateDecl *OldTD = dyn_cast<TemplateDecl>(OldDecl)) {
6040 OldDecl = OldTD->getTemplatedDecl();
6042 if (!IsSpecialization)
6043 IsDefinition = false;
6045 if (TemplateDecl *NewTD = dyn_cast<TemplateDecl>(NewDecl)) {
6046 NewDecl = NewTD->getTemplatedDecl();
6050 if (!OldDecl || !NewDecl)
6053 const DLLImportAttr *OldImportAttr = OldDecl->getAttr<DLLImportAttr>();
6054 const DLLExportAttr *OldExportAttr = OldDecl->getAttr<DLLExportAttr>();
6055 const DLLImportAttr *NewImportAttr = NewDecl->getAttr<DLLImportAttr>();
6056 const DLLExportAttr *NewExportAttr = NewDecl->getAttr<DLLExportAttr>();
6058 // dllimport and dllexport are inheritable attributes so we have to exclude
6059 // inherited attribute instances.
6060 bool HasNewAttr = (NewImportAttr && !NewImportAttr->isInherited()) ||
6061 (NewExportAttr && !NewExportAttr->isInherited());
6063 // A redeclaration is not allowed to add a dllimport or dllexport attribute,
6064 // the only exception being explicit specializations.
6065 // Implicitly generated declarations are also excluded for now because there
6066 // is no other way to switch these to use dllimport or dllexport.
6067 bool AddsAttr = !(OldImportAttr || OldExportAttr) && HasNewAttr;
6069 if (AddsAttr && !IsSpecialization && !OldDecl->isImplicit()) {
6070 // Allow with a warning for free functions and global variables.
6071 bool JustWarn = false;
6072 if (!OldDecl->isCXXClassMember()) {
6073 auto *VD = dyn_cast<VarDecl>(OldDecl);
6074 if (VD && !VD->getDescribedVarTemplate())
6076 auto *FD = dyn_cast<FunctionDecl>(OldDecl);
6077 if (FD && FD->getTemplatedKind() == FunctionDecl::TK_NonTemplate)
6081 // We cannot change a declaration that's been used because IR has already
6082 // been emitted. Dllimported functions will still work though (modulo
6083 // address equality) as they can use the thunk.
6084 if (OldDecl->isUsed())
6085 if (!isa<FunctionDecl>(OldDecl) || !NewImportAttr)
6088 unsigned DiagID = JustWarn ? diag::warn_attribute_dll_redeclaration
6089 : diag::err_attribute_dll_redeclaration;
6090 S.Diag(NewDecl->getLocation(), DiagID)
6092 << (NewImportAttr ? (const Attr *)NewImportAttr : NewExportAttr);
6093 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6095 NewDecl->setInvalidDecl();
6100 // A redeclaration is not allowed to drop a dllimport attribute, the only
6101 // exceptions being inline function definitions (except for function
6102 // templates), local extern declarations, qualified friend declarations or
6103 // special MSVC extension: in the last case, the declaration is treated as if
6104 // it were marked dllexport.
6105 bool IsInline = false, IsStaticDataMember = false, IsQualifiedFriend = false;
6106 bool IsMicrosoft = S.Context.getTargetInfo().getCXXABI().isMicrosoft();
6107 if (const auto *VD = dyn_cast<VarDecl>(NewDecl)) {
6108 // Ignore static data because out-of-line definitions are diagnosed
6110 IsStaticDataMember = VD->isStaticDataMember();
6111 IsDefinition = VD->isThisDeclarationADefinition(S.Context) !=
6112 VarDecl::DeclarationOnly;
6113 } else if (const auto *FD = dyn_cast<FunctionDecl>(NewDecl)) {
6114 IsInline = FD->isInlined();
6115 IsQualifiedFriend = FD->getQualifier() &&
6116 FD->getFriendObjectKind() == Decl::FOK_Declared;
6119 if (OldImportAttr && !HasNewAttr &&
6120 (!IsInline || (IsMicrosoft && IsTemplate)) && !IsStaticDataMember &&
6121 !NewDecl->isLocalExternDecl() && !IsQualifiedFriend) {
6122 if (IsMicrosoft && IsDefinition) {
6123 S.Diag(NewDecl->getLocation(),
6124 diag::warn_redeclaration_without_import_attribute)
6126 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6127 NewDecl->dropAttr<DLLImportAttr>();
6128 NewDecl->addAttr(::new (S.Context) DLLExportAttr(
6129 NewImportAttr->getRange(), S.Context,
6130 NewImportAttr->getSpellingListIndex()));
6132 S.Diag(NewDecl->getLocation(),
6133 diag::warn_redeclaration_without_attribute_prev_attribute_ignored)
6134 << NewDecl << OldImportAttr;
6135 S.Diag(OldDecl->getLocation(), diag::note_previous_declaration);
6136 S.Diag(OldImportAttr->getLocation(), diag::note_previous_attribute);
6137 OldDecl->dropAttr<DLLImportAttr>();
6138 NewDecl->dropAttr<DLLImportAttr>();
6140 } else if (IsInline && OldImportAttr && !IsMicrosoft) {
6141 // In MinGW, seeing a function declared inline drops the dllimport
6143 OldDecl->dropAttr<DLLImportAttr>();
6144 NewDecl->dropAttr<DLLImportAttr>();
6145 S.Diag(NewDecl->getLocation(),
6146 diag::warn_dllimport_dropped_from_inline_function)
6147 << NewDecl << OldImportAttr;
6150 // A specialization of a class template member function is processed here
6151 // since it's a redeclaration. If the parent class is dllexport, the
6152 // specialization inherits that attribute. This doesn't happen automatically
6153 // since the parent class isn't instantiated until later.
6154 if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDecl)) {
6155 if (MD->getTemplatedKind() == FunctionDecl::TK_MemberSpecialization &&
6156 !NewImportAttr && !NewExportAttr) {
6157 if (const DLLExportAttr *ParentExportAttr =
6158 MD->getParent()->getAttr<DLLExportAttr>()) {
6159 DLLExportAttr *NewAttr = ParentExportAttr->clone(S.Context);
6160 NewAttr->setInherited(true);
6161 NewDecl->addAttr(NewAttr);
6167 /// Given that we are within the definition of the given function,
6168 /// will that definition behave like C99's 'inline', where the
6169 /// definition is discarded except for optimization purposes?
6170 static bool isFunctionDefinitionDiscarded(Sema &S, FunctionDecl *FD) {
6171 // Try to avoid calling GetGVALinkageForFunction.
6173 // All cases of this require the 'inline' keyword.
6174 if (!FD->isInlined()) return false;
6176 // This is only possible in C++ with the gnu_inline attribute.
6177 if (S.getLangOpts().CPlusPlus && !FD->hasAttr<GNUInlineAttr>())
6180 // Okay, go ahead and call the relatively-more-expensive function.
6181 return S.Context.GetGVALinkageForFunction(FD) == GVA_AvailableExternally;
6184 /// Determine whether a variable is extern "C" prior to attaching
6185 /// an initializer. We can't just call isExternC() here, because that
6186 /// will also compute and cache whether the declaration is externally
6187 /// visible, which might change when we attach the initializer.
6189 /// This can only be used if the declaration is known to not be a
6190 /// redeclaration of an internal linkage declaration.
6196 /// Attaching the initializer here makes this declaration not externally
6197 /// visible, because its type has internal linkage.
6199 /// FIXME: This is a hack.
6200 template<typename T>
6201 static bool isIncompleteDeclExternC(Sema &S, const T *D) {
6202 if (S.getLangOpts().CPlusPlus) {
6203 // In C++, the overloadable attribute negates the effects of extern "C".
6204 if (!D->isInExternCContext() || D->template hasAttr<OverloadableAttr>())
6207 // So do CUDA's host/device attributes.
6208 if (S.getLangOpts().CUDA && (D->template hasAttr<CUDADeviceAttr>() ||
6209 D->template hasAttr<CUDAHostAttr>()))
6212 return D->isExternC();
6215 static bool shouldConsiderLinkage(const VarDecl *VD) {
6216 const DeclContext *DC = VD->getDeclContext()->getRedeclContext();
6217 if (DC->isFunctionOrMethod() || isa<OMPDeclareReductionDecl>(DC))
6218 return VD->hasExternalStorage();
6219 if (DC->isFileContext())
6223 llvm_unreachable("Unexpected context");
6226 static bool shouldConsiderLinkage(const FunctionDecl *FD) {
6227 const DeclContext *DC = FD->getDeclContext()->getRedeclContext();
6228 if (DC->isFileContext() || DC->isFunctionOrMethod() ||
6229 isa<OMPDeclareReductionDecl>(DC))
6233 llvm_unreachable("Unexpected context");
6236 static bool hasParsedAttr(Scope *S, const Declarator &PD,
6237 ParsedAttr::Kind Kind) {
6238 // Check decl attributes on the DeclSpec.
6239 if (PD.getDeclSpec().getAttributes().hasAttribute(Kind))
6242 // Walk the declarator structure, checking decl attributes that were in a type
6243 // position to the decl itself.
6244 for (unsigned I = 0, E = PD.getNumTypeObjects(); I != E; ++I) {
6245 if (PD.getTypeObject(I).getAttrs().hasAttribute(Kind))
6249 // Finally, check attributes on the decl itself.
6250 return PD.getAttributes().hasAttribute(Kind);
6253 /// Adjust the \c DeclContext for a function or variable that might be a
6254 /// function-local external declaration.
6255 bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
6256 if (!DC->isFunctionOrMethod())
6259 // If this is a local extern function or variable declared within a function
6260 // template, don't add it into the enclosing namespace scope until it is
6261 // instantiated; it might have a dependent type right now.
6262 if (DC->isDependentContext())
6265 // C++11 [basic.link]p7:
6266 // When a block scope declaration of an entity with linkage is not found to
6267 // refer to some other declaration, then that entity is a member of the
6268 // innermost enclosing namespace.
6270 // Per C++11 [namespace.def]p6, the innermost enclosing namespace is a
6271 // semantically-enclosing namespace, not a lexically-enclosing one.
6272 while (!DC->isFileContext() && !isa<LinkageSpecDecl>(DC))
6273 DC = DC->getParent();
6277 /// Returns true if given declaration has external C language linkage.
6278 static bool isDeclExternC(const Decl *D) {
6279 if (const auto *FD = dyn_cast<FunctionDecl>(D))
6280 return FD->isExternC();
6281 if (const auto *VD = dyn_cast<VarDecl>(D))
6282 return VD->isExternC();
6284 llvm_unreachable("Unknown type of decl!");
6287 NamedDecl *Sema::ActOnVariableDeclarator(
6288 Scope *S, Declarator &D, DeclContext *DC, TypeSourceInfo *TInfo,
6289 LookupResult &Previous, MultiTemplateParamsArg TemplateParamLists,
6290 bool &AddToScope, ArrayRef<BindingDecl *> Bindings) {
6291 QualType R = TInfo->getType();
6292 DeclarationName Name = GetNameForDeclarator(D).getName();
6294 IdentifierInfo *II = Name.getAsIdentifierInfo();
6296 if (D.isDecompositionDeclarator()) {
6297 // Take the name of the first declarator as our name for diagnostic
6299 auto &Decomp = D.getDecompositionDeclarator();
6300 if (!Decomp.bindings().empty()) {
6301 II = Decomp.bindings()[0].Name;
6305 Diag(D.getIdentifierLoc(), diag::err_bad_variable_name) << Name;
6309 if (getLangOpts().OpenCL) {
6310 // OpenCL v2.0 s6.9.b - Image type can only be used as a function argument.
6311 // OpenCL v2.0 s6.13.16.1 - Pipe type can only be used as a function
6313 if (R->isImageType() || R->isPipeType()) {
6314 Diag(D.getIdentifierLoc(),
6315 diag::err_opencl_type_can_only_be_used_as_function_parameter)
6321 // OpenCL v1.2 s6.9.r:
6322 // The event type cannot be used to declare a program scope variable.
6323 // OpenCL v2.0 s6.9.q:
6324 // The clk_event_t and reserve_id_t types cannot be declared in program scope.
6325 if (NULL == S->getParent()) {
6326 if (R->isReserveIDT() || R->isClkEventT() || R->isEventT()) {
6327 Diag(D.getIdentifierLoc(),
6328 diag::err_invalid_type_for_program_scope_var) << R;
6334 // OpenCL v1.0 s6.8.a.3: Pointers to functions are not allowed.
6336 while (NR->isPointerType()) {
6337 if (NR->isFunctionPointerType()) {
6338 Diag(D.getIdentifierLoc(), diag::err_opencl_function_pointer);
6342 NR = NR->getPointeeType();
6345 if (!getOpenCLOptions().isEnabled("cl_khr_fp16")) {
6346 // OpenCL v1.2 s6.1.1.1: reject declaring variables of the half and
6347 // half array type (unless the cl_khr_fp16 extension is enabled).
6348 if (Context.getBaseElementType(R)->isHalfType()) {
6349 Diag(D.getIdentifierLoc(), diag::err_opencl_half_declaration) << R;
6354 if (R->isSamplerT()) {
6355 // OpenCL v1.2 s6.9.b p4:
6356 // The sampler type cannot be used with the __local and __global address
6357 // space qualifiers.
6358 if (R.getAddressSpace() == LangAS::opencl_local ||
6359 R.getAddressSpace() == LangAS::opencl_global) {
6360 Diag(D.getIdentifierLoc(), diag::err_wrong_sampler_addressspace);
6363 // OpenCL v1.2 s6.12.14.1:
6364 // A global sampler must be declared with either the constant address
6365 // space qualifier or with the const qualifier.
6366 if (DC->isTranslationUnit() &&
6367 !(R.getAddressSpace() == LangAS::opencl_constant ||
6368 R.isConstQualified())) {
6369 Diag(D.getIdentifierLoc(), diag::err_opencl_nonconst_global_sampler);
6374 // OpenCL v1.2 s6.9.r:
6375 // The event type cannot be used with the __local, __constant and __global
6376 // address space qualifiers.
6377 if (R->isEventT()) {
6378 if (R.getAddressSpace() != LangAS::opencl_private) {
6379 Diag(D.getLocStart(), diag::err_event_t_addr_space_qual);
6384 // OpenCL C++ 1.0 s2.9: the thread_local storage qualifier is not
6385 // supported. OpenCL C does not support thread_local either, and
6386 // also reject all other thread storage class specifiers.
6387 DeclSpec::TSCS TSC = D.getDeclSpec().getThreadStorageClassSpec();
6388 if (TSC != TSCS_unspecified) {
6389 bool IsCXX = getLangOpts().OpenCLCPlusPlus;
6390 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6391 diag::err_opencl_unknown_type_specifier)
6392 << IsCXX << getLangOpts().getOpenCLVersionTuple().getAsString()
6393 << DeclSpec::getSpecifierName(TSC) << 1;
6399 DeclSpec::SCS SCSpec = D.getDeclSpec().getStorageClassSpec();
6400 StorageClass SC = StorageClassSpecToVarDeclStorageClass(D.getDeclSpec());
6402 // dllimport globals without explicit storage class are treated as extern. We
6403 // have to change the storage class this early to get the right DeclContext.
6404 if (SC == SC_None && !DC->isRecord() &&
6405 hasParsedAttr(S, D, ParsedAttr::AT_DLLImport) &&
6406 !hasParsedAttr(S, D, ParsedAttr::AT_DLLExport))
6409 DeclContext *OriginalDC = DC;
6410 bool IsLocalExternDecl = SC == SC_Extern &&
6411 adjustContextForLocalExternDecl(DC);
6413 if (SCSpec == DeclSpec::SCS_mutable) {
6414 // mutable can only appear on non-static class members, so it's always
6416 Diag(D.getIdentifierLoc(), diag::err_mutable_nonmember);
6421 if (getLangOpts().CPlusPlus11 && SCSpec == DeclSpec::SCS_register &&
6422 !D.getAsmLabel() && !getSourceManager().isInSystemMacro(
6423 D.getDeclSpec().getStorageClassSpecLoc())) {
6424 // In C++11, the 'register' storage class specifier is deprecated.
6425 // Suppress the warning in system macros, it's used in macros in some
6426 // popular C system headers, such as in glibc's htonl() macro.
6427 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6428 getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
6429 : diag::warn_deprecated_register)
6430 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6433 DiagnoseFunctionSpecifiers(D.getDeclSpec());
6435 if (!DC->isRecord() && S->getFnParent() == nullptr) {
6436 // C99 6.9p2: The storage-class specifiers auto and register shall not
6437 // appear in the declaration specifiers in an external declaration.
6438 // Global Register+Asm is a GNU extension we support.
6439 if (SC == SC_Auto || (SC == SC_Register && !D.getAsmLabel())) {
6440 Diag(D.getIdentifierLoc(), diag::err_typecheck_sclass_fscope);
6445 bool IsMemberSpecialization = false;
6446 bool IsVariableTemplateSpecialization = false;
6447 bool IsPartialSpecialization = false;
6448 bool IsVariableTemplate = false;
6449 VarDecl *NewVD = nullptr;
6450 VarTemplateDecl *NewTemplate = nullptr;
6451 TemplateParameterList *TemplateParams = nullptr;
6452 if (!getLangOpts().CPlusPlus) {
6453 NewVD = VarDecl::Create(Context, DC, D.getLocStart(),
6454 D.getIdentifierLoc(), II,
6457 if (R->getContainedDeducedType())
6458 ParsingInitForAutoVars.insert(NewVD);
6460 if (D.isInvalidType())
6461 NewVD->setInvalidDecl();
6463 bool Invalid = false;
6465 if (DC->isRecord() && !CurContext->isRecord()) {
6466 // This is an out-of-line definition of a static data member.
6471 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6472 diag::err_static_out_of_line)
6473 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6478 // [dcl.stc] p2: The auto or register specifiers shall be applied only
6479 // to names of variables declared in a block or to function parameters.
6480 // [dcl.stc] p6: The extern specifier cannot be used in the declaration
6483 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6484 diag::err_storage_class_for_static_member)
6485 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
6487 case SC_PrivateExtern:
6488 llvm_unreachable("C storage class in c++!");
6492 if (SC == SC_Static && CurContext->isRecord()) {
6493 if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(DC)) {
6494 if (RD->isLocalClass())
6495 Diag(D.getIdentifierLoc(),
6496 diag::err_static_data_member_not_allowed_in_local_class)
6497 << Name << RD->getDeclName();
6499 // C++98 [class.union]p1: If a union contains a static data member,
6500 // the program is ill-formed. C++11 drops this restriction.
6502 Diag(D.getIdentifierLoc(),
6503 getLangOpts().CPlusPlus11
6504 ? diag::warn_cxx98_compat_static_data_member_in_union
6505 : diag::ext_static_data_member_in_union) << Name;
6506 // We conservatively disallow static data members in anonymous structs.
6507 else if (!RD->getDeclName())
6508 Diag(D.getIdentifierLoc(),
6509 diag::err_static_data_member_not_allowed_in_anon_struct)
6510 << Name << RD->isUnion();
6514 // Match up the template parameter lists with the scope specifier, then
6515 // determine whether we have a template or a template specialization.
6516 TemplateParams = MatchTemplateParametersToScopeSpecifier(
6517 D.getDeclSpec().getLocStart(), D.getIdentifierLoc(),
6518 D.getCXXScopeSpec(),
6519 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
6520 ? D.getName().TemplateId
6523 /*never a friend*/ false, IsMemberSpecialization, Invalid);
6525 if (TemplateParams) {
6526 if (!TemplateParams->size() &&
6527 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
6528 // There is an extraneous 'template<>' for this variable. Complain
6529 // about it, but allow the declaration of the variable.
6530 Diag(TemplateParams->getTemplateLoc(),
6531 diag::err_template_variable_noparams)
6533 << SourceRange(TemplateParams->getTemplateLoc(),
6534 TemplateParams->getRAngleLoc());
6535 TemplateParams = nullptr;
6537 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
6538 // This is an explicit specialization or a partial specialization.
6539 // FIXME: Check that we can declare a specialization here.
6540 IsVariableTemplateSpecialization = true;
6541 IsPartialSpecialization = TemplateParams->size() > 0;
6542 } else { // if (TemplateParams->size() > 0)
6543 // This is a template declaration.
6544 IsVariableTemplate = true;
6546 // Check that we can declare a template here.
6547 if (CheckTemplateDeclScope(S, TemplateParams))
6550 // Only C++1y supports variable templates (N3651).
6551 Diag(D.getIdentifierLoc(),
6552 getLangOpts().CPlusPlus14
6553 ? diag::warn_cxx11_compat_variable_template
6554 : diag::ext_variable_template);
6559 D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) &&
6560 "should have a 'template<>' for this decl");
6563 if (IsVariableTemplateSpecialization) {
6564 SourceLocation TemplateKWLoc =
6565 TemplateParamLists.size() > 0
6566 ? TemplateParamLists[0]->getTemplateLoc()
6568 DeclResult Res = ActOnVarTemplateSpecialization(
6569 S, D, TInfo, TemplateKWLoc, TemplateParams, SC,
6570 IsPartialSpecialization);
6571 if (Res.isInvalid())
6573 NewVD = cast<VarDecl>(Res.get());
6575 } else if (D.isDecompositionDeclarator()) {
6576 NewVD = DecompositionDecl::Create(Context, DC, D.getLocStart(),
6577 D.getIdentifierLoc(), R, TInfo, SC,
6580 NewVD = VarDecl::Create(Context, DC, D.getLocStart(),
6581 D.getIdentifierLoc(), II, R, TInfo, SC);
6583 // If this is supposed to be a variable template, create it as such.
6584 if (IsVariableTemplate) {
6586 VarTemplateDecl::Create(Context, DC, D.getIdentifierLoc(), Name,
6587 TemplateParams, NewVD);
6588 NewVD->setDescribedVarTemplate(NewTemplate);
6591 // If this decl has an auto type in need of deduction, make a note of the
6592 // Decl so we can diagnose uses of it in its own initializer.
6593 if (R->getContainedDeducedType())
6594 ParsingInitForAutoVars.insert(NewVD);
6596 if (D.isInvalidType() || Invalid) {
6597 NewVD->setInvalidDecl();
6599 NewTemplate->setInvalidDecl();
6602 SetNestedNameSpecifier(NewVD, D);
6604 // If we have any template parameter lists that don't directly belong to
6605 // the variable (matching the scope specifier), store them.
6606 unsigned VDTemplateParamLists = TemplateParams ? 1 : 0;
6607 if (TemplateParamLists.size() > VDTemplateParamLists)
6608 NewVD->setTemplateParameterListsInfo(
6609 Context, TemplateParamLists.drop_back(VDTemplateParamLists));
6611 if (D.getDeclSpec().isConstexprSpecified()) {
6612 NewVD->setConstexpr(true);
6613 // C++1z [dcl.spec.constexpr]p1:
6614 // A static data member declared with the constexpr specifier is
6615 // implicitly an inline variable.
6616 if (NewVD->isStaticDataMember() && getLangOpts().CPlusPlus17)
6617 NewVD->setImplicitlyInline();
6621 if (D.getDeclSpec().isInlineSpecified()) {
6622 if (!getLangOpts().CPlusPlus) {
6623 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
6625 } else if (CurContext->isFunctionOrMethod()) {
6626 // 'inline' is not allowed on block scope variable declaration.
6627 Diag(D.getDeclSpec().getInlineSpecLoc(),
6628 diag::err_inline_declaration_block_scope) << Name
6629 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
6631 Diag(D.getDeclSpec().getInlineSpecLoc(),
6632 getLangOpts().CPlusPlus17 ? diag::warn_cxx14_compat_inline_variable
6633 : diag::ext_inline_variable);
6634 NewVD->setInlineSpecified();
6638 // Set the lexical context. If the declarator has a C++ scope specifier, the
6639 // lexical context will be different from the semantic context.
6640 NewVD->setLexicalDeclContext(CurContext);
6642 NewTemplate->setLexicalDeclContext(CurContext);
6644 if (IsLocalExternDecl) {
6645 if (D.isDecompositionDeclarator())
6646 for (auto *B : Bindings)
6647 B->setLocalExternDecl();
6649 NewVD->setLocalExternDecl();
6652 bool EmitTLSUnsupportedError = false;
6653 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec()) {
6654 // C++11 [dcl.stc]p4:
6655 // When thread_local is applied to a variable of block scope the
6656 // storage-class-specifier static is implied if it does not appear
6658 // Core issue: 'static' is not implied if the variable is declared
6660 if (NewVD->hasLocalStorage() &&
6661 (SCSpec != DeclSpec::SCS_unspecified ||
6662 TSCS != DeclSpec::TSCS_thread_local ||
6663 !DC->isFunctionOrMethod()))
6664 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6665 diag::err_thread_non_global)
6666 << DeclSpec::getSpecifierName(TSCS);
6667 else if (!Context.getTargetInfo().isTLSSupported()) {
6668 if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) {
6669 // Postpone error emission until we've collected attributes required to
6670 // figure out whether it's a host or device variable and whether the
6671 // error should be ignored.
6672 EmitTLSUnsupportedError = true;
6673 // We still need to mark the variable as TLS so it shows up in AST with
6674 // proper storage class for other tools to use even if we're not going
6675 // to emit any code for it.
6676 NewVD->setTSCSpec(TSCS);
6678 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6679 diag::err_thread_unsupported);
6681 NewVD->setTSCSpec(TSCS);
6685 // An inline definition of a function with external linkage shall
6686 // not contain a definition of a modifiable object with static or
6687 // thread storage duration...
6688 // We only apply this when the function is required to be defined
6689 // elsewhere, i.e. when the function is not 'extern inline'. Note
6690 // that a local variable with thread storage duration still has to
6691 // be marked 'static'. Also note that it's possible to get these
6692 // semantics in C++ using __attribute__((gnu_inline)).
6693 if (SC == SC_Static && S->getFnParent() != nullptr &&
6694 !NewVD->getType().isConstQualified()) {
6695 FunctionDecl *CurFD = getCurFunctionDecl();
6696 if (CurFD && isFunctionDefinitionDiscarded(*this, CurFD)) {
6697 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
6698 diag::warn_static_local_in_extern_inline);
6699 MaybeSuggestAddingStaticToDecl(CurFD);
6703 if (D.getDeclSpec().isModulePrivateSpecified()) {
6704 if (IsVariableTemplateSpecialization)
6705 Diag(NewVD->getLocation(), diag::err_module_private_specialization)
6706 << (IsPartialSpecialization ? 1 : 0)
6707 << FixItHint::CreateRemoval(
6708 D.getDeclSpec().getModulePrivateSpecLoc());
6709 else if (IsMemberSpecialization)
6710 Diag(NewVD->getLocation(), diag::err_module_private_specialization)
6712 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
6713 else if (NewVD->hasLocalStorage())
6714 Diag(NewVD->getLocation(), diag::err_module_private_local)
6715 << 0 << NewVD->getDeclName()
6716 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
6717 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
6719 NewVD->setModulePrivate();
6721 NewTemplate->setModulePrivate();
6722 for (auto *B : Bindings)
6723 B->setModulePrivate();
6727 // Handle attributes prior to checking for duplicates in MergeVarDecl
6728 ProcessDeclAttributes(S, NewVD, D);
6730 if (getLangOpts().CUDA || getLangOpts().OpenMPIsDevice) {
6731 if (EmitTLSUnsupportedError &&
6732 ((getLangOpts().CUDA && DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) ||
6733 (getLangOpts().OpenMPIsDevice &&
6734 NewVD->hasAttr<OMPDeclareTargetDeclAttr>())))
6735 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
6736 diag::err_thread_unsupported);
6737 // CUDA B.2.5: "__shared__ and __constant__ variables have implied static
6738 // storage [duration]."
6739 if (SC == SC_None && S->getFnParent() != nullptr &&
6740 (NewVD->hasAttr<CUDASharedAttr>() ||
6741 NewVD->hasAttr<CUDAConstantAttr>())) {
6742 NewVD->setStorageClass(SC_Static);
6746 // Ensure that dllimport globals without explicit storage class are treated as
6747 // extern. The storage class is set above using parsed attributes. Now we can
6748 // check the VarDecl itself.
6749 assert(!NewVD->hasAttr<DLLImportAttr>() ||
6750 NewVD->getAttr<DLLImportAttr>()->isInherited() ||
6751 NewVD->isStaticDataMember() || NewVD->getStorageClass() != SC_None);
6753 // In auto-retain/release, infer strong retension for variables of
6755 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewVD))
6756 NewVD->setInvalidDecl();
6758 // Handle GNU asm-label extension (encoded as an attribute).
6759 if (Expr *E = (Expr*)D.getAsmLabel()) {
6760 // The parser guarantees this is a string.
6761 StringLiteral *SE = cast<StringLiteral>(E);
6762 StringRef Label = SE->getString();
6763 if (S->getFnParent() != nullptr) {
6767 Diag(E->getExprLoc(), diag::warn_asm_label_on_auto_decl) << Label;
6770 // Local Named register
6771 if (!Context.getTargetInfo().isValidGCCRegisterName(Label) &&
6772 DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl()))
6773 Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
6777 case SC_PrivateExtern:
6780 } else if (SC == SC_Register) {
6781 // Global Named register
6782 if (DeclAttrsMatchCUDAMode(getLangOpts(), NewVD)) {
6783 const auto &TI = Context.getTargetInfo();
6784 bool HasSizeMismatch;
6786 if (!TI.isValidGCCRegisterName(Label))
6787 Diag(E->getExprLoc(), diag::err_asm_unknown_register_name) << Label;
6788 else if (!TI.validateGlobalRegisterVariable(Label,
6789 Context.getTypeSize(R),
6791 Diag(E->getExprLoc(), diag::err_asm_invalid_global_var_reg) << Label;
6792 else if (HasSizeMismatch)
6793 Diag(E->getExprLoc(), diag::err_asm_register_size_mismatch) << Label;
6796 if (!R->isIntegralType(Context) && !R->isPointerType()) {
6797 Diag(D.getLocStart(), diag::err_asm_bad_register_type);
6798 NewVD->setInvalidDecl(true);
6802 NewVD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0),
6803 Context, Label, 0));
6804 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
6805 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
6806 ExtnameUndeclaredIdentifiers.find(NewVD->getIdentifier());
6807 if (I != ExtnameUndeclaredIdentifiers.end()) {
6808 if (isDeclExternC(NewVD)) {
6809 NewVD->addAttr(I->second);
6810 ExtnameUndeclaredIdentifiers.erase(I);
6812 Diag(NewVD->getLocation(), diag::warn_redefine_extname_not_applied)
6813 << /*Variable*/1 << NewVD;
6817 // Find the shadowed declaration before filtering for scope.
6818 NamedDecl *ShadowedDecl = D.getCXXScopeSpec().isEmpty()
6819 ? getShadowedDeclaration(NewVD, Previous)
6822 // Don't consider existing declarations that are in a different
6823 // scope and are out-of-semantic-context declarations (if the new
6824 // declaration has linkage).
6825 FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewVD),
6826 D.getCXXScopeSpec().isNotEmpty() ||
6827 IsMemberSpecialization ||
6828 IsVariableTemplateSpecialization);
6830 // Check whether the previous declaration is in the same block scope. This
6831 // affects whether we merge types with it, per C++11 [dcl.array]p3.
6832 if (getLangOpts().CPlusPlus &&
6833 NewVD->isLocalVarDecl() && NewVD->hasExternalStorage())
6834 NewVD->setPreviousDeclInSameBlockScope(
6835 Previous.isSingleResult() && !Previous.isShadowed() &&
6836 isDeclInScope(Previous.getFoundDecl(), OriginalDC, S, false));
6838 if (!getLangOpts().CPlusPlus) {
6839 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
6841 // If this is an explicit specialization of a static data member, check it.
6842 if (IsMemberSpecialization && !NewVD->isInvalidDecl() &&
6843 CheckMemberSpecialization(NewVD, Previous))
6844 NewVD->setInvalidDecl();
6846 // Merge the decl with the existing one if appropriate.
6847 if (!Previous.empty()) {
6848 if (Previous.isSingleResult() &&
6849 isa<FieldDecl>(Previous.getFoundDecl()) &&
6850 D.getCXXScopeSpec().isSet()) {
6851 // The user tried to define a non-static data member
6852 // out-of-line (C++ [dcl.meaning]p1).
6853 Diag(NewVD->getLocation(), diag::err_nonstatic_member_out_of_line)
6854 << D.getCXXScopeSpec().getRange();
6856 NewVD->setInvalidDecl();
6858 } else if (D.getCXXScopeSpec().isSet()) {
6859 // No previous declaration in the qualifying scope.
6860 Diag(D.getIdentifierLoc(), diag::err_no_member)
6861 << Name << computeDeclContext(D.getCXXScopeSpec(), true)
6862 << D.getCXXScopeSpec().getRange();
6863 NewVD->setInvalidDecl();
6866 if (!IsVariableTemplateSpecialization)
6867 D.setRedeclaration(CheckVariableDeclaration(NewVD, Previous));
6870 VarTemplateDecl *PrevVarTemplate =
6871 NewVD->getPreviousDecl()
6872 ? NewVD->getPreviousDecl()->getDescribedVarTemplate()
6875 // Check the template parameter list of this declaration, possibly
6876 // merging in the template parameter list from the previous variable
6877 // template declaration.
6878 if (CheckTemplateParameterList(
6880 PrevVarTemplate ? PrevVarTemplate->getTemplateParameters()
6882 (D.getCXXScopeSpec().isSet() && DC && DC->isRecord() &&
6883 DC->isDependentContext())
6884 ? TPC_ClassTemplateMember
6886 NewVD->setInvalidDecl();
6888 // If we are providing an explicit specialization of a static variable
6889 // template, make a note of that.
6890 if (PrevVarTemplate &&
6891 PrevVarTemplate->getInstantiatedFromMemberTemplate())
6892 PrevVarTemplate->setMemberSpecialization();
6896 // Diagnose shadowed variables iff this isn't a redeclaration.
6897 if (ShadowedDecl && !D.isRedeclaration())
6898 CheckShadow(NewVD, ShadowedDecl, Previous);
6900 ProcessPragmaWeak(S, NewVD);
6902 // If this is the first declaration of an extern C variable, update
6903 // the map of such variables.
6904 if (NewVD->isFirstDecl() && !NewVD->isInvalidDecl() &&
6905 isIncompleteDeclExternC(*this, NewVD))
6906 RegisterLocallyScopedExternCDecl(NewVD, S);
6908 if (getLangOpts().CPlusPlus && NewVD->isStaticLocal()) {
6909 Decl *ManglingContextDecl;
6910 if (MangleNumberingContext *MCtx = getCurrentMangleNumberContext(
6911 NewVD->getDeclContext(), ManglingContextDecl)) {
6912 Context.setManglingNumber(
6913 NewVD, MCtx->getManglingNumber(
6914 NewVD, getMSManglingNumber(getLangOpts(), S)));
6915 Context.setStaticLocalNumber(NewVD, MCtx->getStaticLocalNumber(NewVD));
6919 // Special handling of variable named 'main'.
6920 if (Name.getAsIdentifierInfo() && Name.getAsIdentifierInfo()->isStr("main") &&
6921 NewVD->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
6922 !getLangOpts().Freestanding && !NewVD->getDescribedVarTemplate()) {
6924 // C++ [basic.start.main]p3
6925 // A program that declares a variable main at global scope is ill-formed.
6926 if (getLangOpts().CPlusPlus)
6927 Diag(D.getLocStart(), diag::err_main_global_variable);
6929 // In C, and external-linkage variable named main results in undefined
6931 else if (NewVD->hasExternalFormalLinkage())
6932 Diag(D.getLocStart(), diag::warn_main_redefined);
6935 if (D.isRedeclaration() && !Previous.empty()) {
6936 NamedDecl *Prev = Previous.getRepresentativeDecl();
6937 checkDLLAttributeRedeclaration(*this, Prev, NewVD, IsMemberSpecialization,
6938 D.isFunctionDefinition());
6942 if (NewVD->isInvalidDecl())
6943 NewTemplate->setInvalidDecl();
6944 ActOnDocumentableDecl(NewTemplate);
6948 if (IsMemberSpecialization && !NewVD->isInvalidDecl())
6949 CompleteMemberSpecialization(NewVD, Previous);
6954 /// Enum describing the %select options in diag::warn_decl_shadow.
6955 enum ShadowedDeclKind {
6964 /// Determine what kind of declaration we're shadowing.
6965 static ShadowedDeclKind computeShadowedDeclKind(const NamedDecl *ShadowedDecl,
6966 const DeclContext *OldDC) {
6967 if (isa<TypeAliasDecl>(ShadowedDecl))
6969 else if (isa<TypedefDecl>(ShadowedDecl))
6971 else if (isa<RecordDecl>(OldDC))
6972 return isa<FieldDecl>(ShadowedDecl) ? SDK_Field : SDK_StaticMember;
6974 return OldDC->isFileContext() ? SDK_Global : SDK_Local;
6977 /// Return the location of the capture if the given lambda captures the given
6978 /// variable \p VD, or an invalid source location otherwise.
6979 static SourceLocation getCaptureLocation(const LambdaScopeInfo *LSI,
6980 const VarDecl *VD) {
6981 for (const Capture &Capture : LSI->Captures) {
6982 if (Capture.isVariableCapture() && Capture.getVariable() == VD)
6983 return Capture.getLocation();
6985 return SourceLocation();
6988 static bool shouldWarnIfShadowedDecl(const DiagnosticsEngine &Diags,
6989 const LookupResult &R) {
6990 // Only diagnose if we're shadowing an unambiguous field or variable.
6991 if (R.getResultKind() != LookupResult::Found)
6994 // Return false if warning is ignored.
6995 return !Diags.isIgnored(diag::warn_decl_shadow, R.getNameLoc());
6998 /// Return the declaration shadowed by the given variable \p D, or null
6999 /// if it doesn't shadow any declaration or shadowing warnings are disabled.
7000 NamedDecl *Sema::getShadowedDeclaration(const VarDecl *D,
7001 const LookupResult &R) {
7002 if (!shouldWarnIfShadowedDecl(Diags, R))
7005 // Don't diagnose declarations at file scope.
7006 if (D->hasGlobalStorage())
7009 NamedDecl *ShadowedDecl = R.getFoundDecl();
7010 return isa<VarDecl>(ShadowedDecl) || isa<FieldDecl>(ShadowedDecl)
7015 /// Return the declaration shadowed by the given typedef \p D, or null
7016 /// if it doesn't shadow any declaration or shadowing warnings are disabled.
7017 NamedDecl *Sema::getShadowedDeclaration(const TypedefNameDecl *D,
7018 const LookupResult &R) {
7019 // Don't warn if typedef declaration is part of a class
7020 if (D->getDeclContext()->isRecord())
7023 if (!shouldWarnIfShadowedDecl(Diags, R))
7026 NamedDecl *ShadowedDecl = R.getFoundDecl();
7027 return isa<TypedefNameDecl>(ShadowedDecl) ? ShadowedDecl : nullptr;
7030 /// Diagnose variable or built-in function shadowing. Implements
7033 /// This method is called whenever a VarDecl is added to a "useful"
7036 /// \param ShadowedDecl the declaration that is shadowed by the given variable
7037 /// \param R the lookup of the name
7039 void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
7040 const LookupResult &R) {
7041 DeclContext *NewDC = D->getDeclContext();
7043 if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) {
7044 // Fields are not shadowed by variables in C++ static methods.
7045 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewDC))
7049 // Fields shadowed by constructor parameters are a special case. Usually
7050 // the constructor initializes the field with the parameter.
7051 if (isa<CXXConstructorDecl>(NewDC))
7052 if (const auto PVD = dyn_cast<ParmVarDecl>(D)) {
7053 // Remember that this was shadowed so we can either warn about its
7054 // modification or its existence depending on warning settings.
7055 ShadowingDecls.insert({PVD->getCanonicalDecl(), FD});
7060 if (VarDecl *shadowedVar = dyn_cast<VarDecl>(ShadowedDecl))
7061 if (shadowedVar->isExternC()) {
7062 // For shadowing external vars, make sure that we point to the global
7063 // declaration, not a locally scoped extern declaration.
7064 for (auto I : shadowedVar->redecls())
7065 if (I->isFileVarDecl()) {
7071 DeclContext *OldDC = ShadowedDecl->getDeclContext()->getRedeclContext();
7073 unsigned WarningDiag = diag::warn_decl_shadow;
7074 SourceLocation CaptureLoc;
7075 if (isa<VarDecl>(D) && isa<VarDecl>(ShadowedDecl) && NewDC &&
7076 isa<CXXMethodDecl>(NewDC)) {
7077 if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
7078 if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
7079 if (RD->getLambdaCaptureDefault() == LCD_None) {
7080 // Try to avoid warnings for lambdas with an explicit capture list.
7081 const auto *LSI = cast<LambdaScopeInfo>(getCurFunction());
7082 // Warn only when the lambda captures the shadowed decl explicitly.
7083 CaptureLoc = getCaptureLocation(LSI, cast<VarDecl>(ShadowedDecl));
7084 if (CaptureLoc.isInvalid())
7085 WarningDiag = diag::warn_decl_shadow_uncaptured_local;
7087 // Remember that this was shadowed so we can avoid the warning if the
7088 // shadowed decl isn't captured and the warning settings allow it.
7089 cast<LambdaScopeInfo>(getCurFunction())
7090 ->ShadowingDecls.push_back(
7091 {cast<VarDecl>(D), cast<VarDecl>(ShadowedDecl)});
7096 if (cast<VarDecl>(ShadowedDecl)->hasLocalStorage()) {
7097 // A variable can't shadow a local variable in an enclosing scope, if
7098 // they are separated by a non-capturing declaration context.
7099 for (DeclContext *ParentDC = NewDC;
7100 ParentDC && !ParentDC->Equals(OldDC);
7101 ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) {
7102 // Only block literals, captured statements, and lambda expressions
7103 // can capture; other scopes don't.
7104 if (!isa<BlockDecl>(ParentDC) && !isa<CapturedDecl>(ParentDC) &&
7105 !isLambdaCallOperator(ParentDC)) {
7113 // Only warn about certain kinds of shadowing for class members.
7114 if (NewDC && NewDC->isRecord()) {
7115 // In particular, don't warn about shadowing non-class members.
7116 if (!OldDC->isRecord())
7119 // TODO: should we warn about static data members shadowing
7120 // static data members from base classes?
7122 // TODO: don't diagnose for inaccessible shadowed members.
7123 // This is hard to do perfectly because we might friend the
7124 // shadowing context, but that's just a false negative.
7128 DeclarationName Name = R.getLookupName();
7130 // Emit warning and note.
7131 if (getSourceManager().isInSystemMacro(R.getNameLoc()))
7133 ShadowedDeclKind Kind = computeShadowedDeclKind(ShadowedDecl, OldDC);
7134 Diag(R.getNameLoc(), WarningDiag) << Name << Kind << OldDC;
7135 if (!CaptureLoc.isInvalid())
7136 Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
7137 << Name << /*explicitly*/ 1;
7138 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7141 /// Diagnose shadowing for variables shadowed in the lambda record \p LambdaRD
7142 /// when these variables are captured by the lambda.
7143 void Sema::DiagnoseShadowingLambdaDecls(const LambdaScopeInfo *LSI) {
7144 for (const auto &Shadow : LSI->ShadowingDecls) {
7145 const VarDecl *ShadowedDecl = Shadow.ShadowedDecl;
7146 // Try to avoid the warning when the shadowed decl isn't captured.
7147 SourceLocation CaptureLoc = getCaptureLocation(LSI, ShadowedDecl);
7148 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
7149 Diag(Shadow.VD->getLocation(), CaptureLoc.isInvalid()
7150 ? diag::warn_decl_shadow_uncaptured_local
7151 : diag::warn_decl_shadow)
7152 << Shadow.VD->getDeclName()
7153 << computeShadowedDeclKind(ShadowedDecl, OldDC) << OldDC;
7154 if (!CaptureLoc.isInvalid())
7155 Diag(CaptureLoc, diag::note_var_explicitly_captured_here)
7156 << Shadow.VD->getDeclName() << /*explicitly*/ 0;
7157 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7161 /// Check -Wshadow without the advantage of a previous lookup.
7162 void Sema::CheckShadow(Scope *S, VarDecl *D) {
7163 if (Diags.isIgnored(diag::warn_decl_shadow, D->getLocation()))
7166 LookupResult R(*this, D->getDeclName(), D->getLocation(),
7167 Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
7169 if (NamedDecl *ShadowedDecl = getShadowedDeclaration(D, R))
7170 CheckShadow(D, ShadowedDecl, R);
7173 /// Check if 'E', which is an expression that is about to be modified, refers
7174 /// to a constructor parameter that shadows a field.
7175 void Sema::CheckShadowingDeclModification(Expr *E, SourceLocation Loc) {
7176 // Quickly ignore expressions that can't be shadowing ctor parameters.
7177 if (!getLangOpts().CPlusPlus || ShadowingDecls.empty())
7179 E = E->IgnoreParenImpCasts();
7180 auto *DRE = dyn_cast<DeclRefExpr>(E);
7183 const NamedDecl *D = cast<NamedDecl>(DRE->getDecl()->getCanonicalDecl());
7184 auto I = ShadowingDecls.find(D);
7185 if (I == ShadowingDecls.end())
7187 const NamedDecl *ShadowedDecl = I->second;
7188 const DeclContext *OldDC = ShadowedDecl->getDeclContext();
7189 Diag(Loc, diag::warn_modifying_shadowing_decl) << D << OldDC;
7190 Diag(D->getLocation(), diag::note_var_declared_here) << D;
7191 Diag(ShadowedDecl->getLocation(), diag::note_previous_declaration);
7193 // Avoid issuing multiple warnings about the same decl.
7194 ShadowingDecls.erase(I);
7197 /// Check for conflict between this global or extern "C" declaration and
7198 /// previous global or extern "C" declarations. This is only used in C++.
7199 template<typename T>
7200 static bool checkGlobalOrExternCConflict(
7201 Sema &S, const T *ND, bool IsGlobal, LookupResult &Previous) {
7202 assert(S.getLangOpts().CPlusPlus && "only C++ has extern \"C\"");
7203 NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName());
7205 if (!Prev && IsGlobal && !isIncompleteDeclExternC(S, ND)) {
7206 // The common case: this global doesn't conflict with any extern "C"
7212 if (!IsGlobal || isIncompleteDeclExternC(S, ND)) {
7213 // Both the old and new declarations have C language linkage. This is a
7216 Previous.addDecl(Prev);
7220 // This is a global, non-extern "C" declaration, and there is a previous
7221 // non-global extern "C" declaration. Diagnose if this is a variable
7223 if (!isa<VarDecl>(ND))
7226 // The declaration is extern "C". Check for any declaration in the
7227 // translation unit which might conflict.
7229 // We have already performed the lookup into the translation unit.
7231 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7233 if (isa<VarDecl>(*I)) {
7239 DeclContext::lookup_result R =
7240 S.Context.getTranslationUnitDecl()->lookup(ND->getDeclName());
7241 for (DeclContext::lookup_result::iterator I = R.begin(), E = R.end();
7243 if (isa<VarDecl>(*I)) {
7247 // FIXME: If we have any other entity with this name in global scope,
7248 // the declaration is ill-formed, but that is a defect: it breaks the
7249 // 'stat' hack, for instance. Only variables can have mangled name
7250 // clashes with extern "C" declarations, so only they deserve a
7259 // Use the first declaration's location to ensure we point at something which
7260 // is lexically inside an extern "C" linkage-spec.
7261 assert(Prev && "should have found a previous declaration to diagnose");
7262 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Prev))
7263 Prev = FD->getFirstDecl();
7265 Prev = cast<VarDecl>(Prev)->getFirstDecl();
7267 S.Diag(ND->getLocation(), diag::err_extern_c_global_conflict)
7269 S.Diag(Prev->getLocation(), diag::note_extern_c_global_conflict)
7274 /// Apply special rules for handling extern "C" declarations. Returns \c true
7275 /// if we have found that this is a redeclaration of some prior entity.
7277 /// Per C++ [dcl.link]p6:
7278 /// Two declarations [for a function or variable] with C language linkage
7279 /// with the same name that appear in different scopes refer to the same
7280 /// [entity]. An entity with C language linkage shall not be declared with
7281 /// the same name as an entity in global scope.
7282 template<typename T>
7283 static bool checkForConflictWithNonVisibleExternC(Sema &S, const T *ND,
7284 LookupResult &Previous) {
7285 if (!S.getLangOpts().CPlusPlus) {
7286 // In C, when declaring a global variable, look for a corresponding 'extern'
7287 // variable declared in function scope. We don't need this in C++, because
7288 // we find local extern decls in the surrounding file-scope DeclContext.
7289 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
7290 if (NamedDecl *Prev = S.findLocallyScopedExternCDecl(ND->getDeclName())) {
7292 Previous.addDecl(Prev);
7299 // A declaration in the translation unit can conflict with an extern "C"
7301 if (ND->getDeclContext()->getRedeclContext()->isTranslationUnit())
7302 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/true, Previous);
7304 // An extern "C" declaration can conflict with a declaration in the
7305 // translation unit or can be a redeclaration of an extern "C" declaration
7306 // in another scope.
7307 if (isIncompleteDeclExternC(S,ND))
7308 return checkGlobalOrExternCConflict(S, ND, /*IsGlobal*/false, Previous);
7310 // Neither global nor extern "C": nothing to do.
7314 void Sema::CheckVariableDeclarationType(VarDecl *NewVD) {
7315 // If the decl is already known invalid, don't check it.
7316 if (NewVD->isInvalidDecl())
7319 QualType T = NewVD->getType();
7321 // Defer checking an 'auto' type until its initializer is attached.
7322 if (T->isUndeducedType())
7325 if (NewVD->hasAttrs())
7326 CheckAlignasUnderalignment(NewVD);
7328 if (T->isObjCObjectType()) {
7329 Diag(NewVD->getLocation(), diag::err_statically_allocated_object)
7330 << FixItHint::CreateInsertion(NewVD->getLocation(), "*");
7331 T = Context.getObjCObjectPointerType(T);
7335 // Emit an error if an address space was applied to decl with local storage.
7336 // This includes arrays of objects with address space qualifiers, but not
7337 // automatic variables that point to other address spaces.
7338 // ISO/IEC TR 18037 S5.1.2
7339 if (!getLangOpts().OpenCL && NewVD->hasLocalStorage() &&
7340 T.getAddressSpace() != LangAS::Default) {
7341 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 0;
7342 NewVD->setInvalidDecl();
7346 // OpenCL v1.2 s6.8 - The static qualifier is valid only in program
7348 if (getLangOpts().OpenCLVersion == 120 &&
7349 !getOpenCLOptions().isEnabled("cl_clang_storage_class_specifiers") &&
7350 NewVD->isStaticLocal()) {
7351 Diag(NewVD->getLocation(), diag::err_static_function_scope);
7352 NewVD->setInvalidDecl();
7356 if (getLangOpts().OpenCL) {
7357 // OpenCL v2.0 s6.12.5 - The __block storage type is not supported.
7358 if (NewVD->hasAttr<BlocksAttr>()) {
7359 Diag(NewVD->getLocation(), diag::err_opencl_block_storage_type);
7363 if (T->isBlockPointerType()) {
7364 // OpenCL v2.0 s6.12.5 - Any block declaration must be const qualified and
7365 // can't use 'extern' storage class.
7366 if (!T.isConstQualified()) {
7367 Diag(NewVD->getLocation(), diag::err_opencl_invalid_block_declaration)
7369 NewVD->setInvalidDecl();
7372 if (NewVD->hasExternalStorage()) {
7373 Diag(NewVD->getLocation(), diag::err_opencl_extern_block_declaration);
7374 NewVD->setInvalidDecl();
7378 // OpenCL v1.2 s6.5 - All program scope variables must be declared in the
7379 // __constant address space.
7380 // OpenCL v2.0 s6.5.1 - Variables defined at program scope and static
7381 // variables inside a function can also be declared in the global
7383 if (NewVD->isFileVarDecl() || NewVD->isStaticLocal() ||
7384 NewVD->hasExternalStorage()) {
7385 if (!T->isSamplerT() &&
7386 !(T.getAddressSpace() == LangAS::opencl_constant ||
7387 (T.getAddressSpace() == LangAS::opencl_global &&
7388 getLangOpts().OpenCLVersion == 200))) {
7389 int Scope = NewVD->isStaticLocal() | NewVD->hasExternalStorage() << 1;
7390 if (getLangOpts().OpenCLVersion == 200)
7391 Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
7392 << Scope << "global or constant";
7394 Diag(NewVD->getLocation(), diag::err_opencl_global_invalid_addr_space)
7395 << Scope << "constant";
7396 NewVD->setInvalidDecl();
7400 if (T.getAddressSpace() == LangAS::opencl_global) {
7401 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7402 << 1 /*is any function*/ << "global";
7403 NewVD->setInvalidDecl();
7406 if (T.getAddressSpace() == LangAS::opencl_constant ||
7407 T.getAddressSpace() == LangAS::opencl_local) {
7408 FunctionDecl *FD = getCurFunctionDecl();
7409 // OpenCL v1.1 s6.5.2 and s6.5.3: no local or constant variables
7411 if (FD && !FD->hasAttr<OpenCLKernelAttr>()) {
7412 if (T.getAddressSpace() == LangAS::opencl_constant)
7413 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7414 << 0 /*non-kernel only*/ << "constant";
7416 Diag(NewVD->getLocation(), diag::err_opencl_function_variable)
7417 << 0 /*non-kernel only*/ << "local";
7418 NewVD->setInvalidDecl();
7421 // OpenCL v2.0 s6.5.2 and s6.5.3: local and constant variables must be
7422 // in the outermost scope of a kernel function.
7423 if (FD && FD->hasAttr<OpenCLKernelAttr>()) {
7424 if (!getCurScope()->isFunctionScope()) {
7425 if (T.getAddressSpace() == LangAS::opencl_constant)
7426 Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
7429 Diag(NewVD->getLocation(), diag::err_opencl_addrspace_scope)
7431 NewVD->setInvalidDecl();
7435 } else if (T.getAddressSpace() != LangAS::opencl_private) {
7436 // Do not allow other address spaces on automatic variable.
7437 Diag(NewVD->getLocation(), diag::err_as_qualified_auto_decl) << 1;
7438 NewVD->setInvalidDecl();
7444 if (NewVD->hasLocalStorage() && T.isObjCGCWeak()
7445 && !NewVD->hasAttr<BlocksAttr>()) {
7446 if (getLangOpts().getGC() != LangOptions::NonGC)
7447 Diag(NewVD->getLocation(), diag::warn_gc_attribute_weak_on_local);
7449 assert(!getLangOpts().ObjCAutoRefCount);
7450 Diag(NewVD->getLocation(), diag::warn_attribute_weak_on_local);
7454 bool isVM = T->isVariablyModifiedType();
7455 if (isVM || NewVD->hasAttr<CleanupAttr>() ||
7456 NewVD->hasAttr<BlocksAttr>())
7457 setFunctionHasBranchProtectedScope();
7459 if ((isVM && NewVD->hasLinkage()) ||
7460 (T->isVariableArrayType() && NewVD->hasGlobalStorage())) {
7461 bool SizeIsNegative;
7462 llvm::APSInt Oversized;
7463 TypeSourceInfo *FixedTInfo = TryToFixInvalidVariablyModifiedTypeSourceInfo(
7464 NewVD->getTypeSourceInfo(), Context, SizeIsNegative, Oversized);
7466 if (FixedTInfo && T == NewVD->getTypeSourceInfo()->getType())
7467 FixedT = FixedTInfo->getType();
7468 else if (FixedTInfo) {
7469 // Type and type-as-written are canonically different. We need to fix up
7470 // both types separately.
7471 FixedT = TryToFixInvalidVariablyModifiedType(T, Context, SizeIsNegative,
7474 if ((!FixedTInfo || FixedT.isNull()) && T->isVariableArrayType()) {
7475 const VariableArrayType *VAT = Context.getAsVariableArrayType(T);
7476 // FIXME: This won't give the correct result for
7478 SourceRange SizeRange = VAT->getSizeExpr()->getSourceRange();
7480 if (NewVD->isFileVarDecl())
7481 Diag(NewVD->getLocation(), diag::err_vla_decl_in_file_scope)
7483 else if (NewVD->isStaticLocal())
7484 Diag(NewVD->getLocation(), diag::err_vla_decl_has_static_storage)
7487 Diag(NewVD->getLocation(), diag::err_vla_decl_has_extern_linkage)
7489 NewVD->setInvalidDecl();
7494 if (NewVD->isFileVarDecl())
7495 Diag(NewVD->getLocation(), diag::err_vm_decl_in_file_scope);
7497 Diag(NewVD->getLocation(), diag::err_vm_decl_has_extern_linkage);
7498 NewVD->setInvalidDecl();
7502 Diag(NewVD->getLocation(), diag::warn_illegal_constant_array_size);
7503 NewVD->setType(FixedT);
7504 NewVD->setTypeSourceInfo(FixedTInfo);
7507 if (T->isVoidType()) {
7508 // C++98 [dcl.stc]p5: The extern specifier can be applied only to the names
7509 // of objects and functions.
7510 if (NewVD->isThisDeclarationADefinition() || getLangOpts().CPlusPlus) {
7511 Diag(NewVD->getLocation(), diag::err_typecheck_decl_incomplete_type)
7513 NewVD->setInvalidDecl();
7518 if (!NewVD->hasLocalStorage() && NewVD->hasAttr<BlocksAttr>()) {
7519 Diag(NewVD->getLocation(), diag::err_block_on_nonlocal);
7520 NewVD->setInvalidDecl();
7524 if (isVM && NewVD->hasAttr<BlocksAttr>()) {
7525 Diag(NewVD->getLocation(), diag::err_block_on_vm);
7526 NewVD->setInvalidDecl();
7530 if (NewVD->isConstexpr() && !T->isDependentType() &&
7531 RequireLiteralType(NewVD->getLocation(), T,
7532 diag::err_constexpr_var_non_literal)) {
7533 NewVD->setInvalidDecl();
7538 /// Perform semantic checking on a newly-created variable
7541 /// This routine performs all of the type-checking required for a
7542 /// variable declaration once it has been built. It is used both to
7543 /// check variables after they have been parsed and their declarators
7544 /// have been translated into a declaration, and to check variables
7545 /// that have been instantiated from a template.
7547 /// Sets NewVD->isInvalidDecl() if an error was encountered.
7549 /// Returns true if the variable declaration is a redeclaration.
7550 bool Sema::CheckVariableDeclaration(VarDecl *NewVD, LookupResult &Previous) {
7551 CheckVariableDeclarationType(NewVD);
7553 // If the decl is already known invalid, don't check it.
7554 if (NewVD->isInvalidDecl())
7557 // If we did not find anything by this name, look for a non-visible
7558 // extern "C" declaration with the same name.
7559 if (Previous.empty() &&
7560 checkForConflictWithNonVisibleExternC(*this, NewVD, Previous))
7561 Previous.setShadowed();
7563 if (!Previous.empty()) {
7564 MergeVarDecl(NewVD, Previous);
7571 struct FindOverriddenMethod {
7573 CXXMethodDecl *Method;
7575 /// Member lookup function that determines whether a given C++
7576 /// method overrides a method in a base class, to be used with
7577 /// CXXRecordDecl::lookupInBases().
7578 bool operator()(const CXXBaseSpecifier *Specifier, CXXBasePath &Path) {
7579 RecordDecl *BaseRecord =
7580 Specifier->getType()->getAs<RecordType>()->getDecl();
7582 DeclarationName Name = Method->getDeclName();
7584 // FIXME: Do we care about other names here too?
7585 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
7586 // We really want to find the base class destructor here.
7587 QualType T = S->Context.getTypeDeclType(BaseRecord);
7588 CanQualType CT = S->Context.getCanonicalType(T);
7590 Name = S->Context.DeclarationNames.getCXXDestructorName(CT);
7593 for (Path.Decls = BaseRecord->lookup(Name); !Path.Decls.empty();
7594 Path.Decls = Path.Decls.slice(1)) {
7595 NamedDecl *D = Path.Decls.front();
7596 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(D)) {
7597 if (MD->isVirtual() && !S->IsOverload(Method, MD, false))
7606 enum OverrideErrorKind { OEK_All, OEK_NonDeleted, OEK_Deleted };
7607 } // end anonymous namespace
7609 /// Report an error regarding overriding, along with any relevant
7610 /// overridden methods.
7612 /// \param DiagID the primary error to report.
7613 /// \param MD the overriding method.
7614 /// \param OEK which overrides to include as notes.
7615 static void ReportOverrides(Sema& S, unsigned DiagID, const CXXMethodDecl *MD,
7616 OverrideErrorKind OEK = OEK_All) {
7617 S.Diag(MD->getLocation(), DiagID) << MD->getDeclName();
7618 for (const CXXMethodDecl *O : MD->overridden_methods()) {
7619 // This check (& the OEK parameter) could be replaced by a predicate, but
7620 // without lambdas that would be overkill. This is still nicer than writing
7621 // out the diag loop 3 times.
7622 if ((OEK == OEK_All) ||
7623 (OEK == OEK_NonDeleted && !O->isDeleted()) ||
7624 (OEK == OEK_Deleted && O->isDeleted()))
7625 S.Diag(O->getLocation(), diag::note_overridden_virtual_function);
7629 /// AddOverriddenMethods - See if a method overrides any in the base classes,
7630 /// and if so, check that it's a valid override and remember it.
7631 bool Sema::AddOverriddenMethods(CXXRecordDecl *DC, CXXMethodDecl *MD) {
7632 // Look for methods in base classes that this method might override.
7634 FindOverriddenMethod FOM;
7637 bool hasDeletedOverridenMethods = false;
7638 bool hasNonDeletedOverridenMethods = false;
7639 bool AddedAny = false;
7640 if (DC->lookupInBases(FOM, Paths)) {
7641 for (auto *I : Paths.found_decls()) {
7642 if (CXXMethodDecl *OldMD = dyn_cast<CXXMethodDecl>(I)) {
7643 MD->addOverriddenMethod(OldMD->getCanonicalDecl());
7644 if (!CheckOverridingFunctionReturnType(MD, OldMD) &&
7645 !CheckOverridingFunctionAttributes(MD, OldMD) &&
7646 !CheckOverridingFunctionExceptionSpec(MD, OldMD) &&
7647 !CheckIfOverriddenFunctionIsMarkedFinal(MD, OldMD)) {
7648 hasDeletedOverridenMethods |= OldMD->isDeleted();
7649 hasNonDeletedOverridenMethods |= !OldMD->isDeleted();
7656 if (hasDeletedOverridenMethods && !MD->isDeleted()) {
7657 ReportOverrides(*this, diag::err_non_deleted_override, MD, OEK_Deleted);
7659 if (hasNonDeletedOverridenMethods && MD->isDeleted()) {
7660 ReportOverrides(*this, diag::err_deleted_override, MD, OEK_NonDeleted);
7667 // Struct for holding all of the extra arguments needed by
7668 // DiagnoseInvalidRedeclaration to call Sema::ActOnFunctionDeclarator.
7669 struct ActOnFDArgs {
7672 MultiTemplateParamsArg TemplateParamLists;
7675 } // end anonymous namespace
7679 // Callback to only accept typo corrections that have a non-zero edit distance.
7680 // Also only accept corrections that have the same parent decl.
7681 class DifferentNameValidatorCCC : public CorrectionCandidateCallback {
7683 DifferentNameValidatorCCC(ASTContext &Context, FunctionDecl *TypoFD,
7684 CXXRecordDecl *Parent)
7685 : Context(Context), OriginalFD(TypoFD),
7686 ExpectedParent(Parent ? Parent->getCanonicalDecl() : nullptr) {}
7688 bool ValidateCandidate(const TypoCorrection &candidate) override {
7689 if (candidate.getEditDistance() == 0)
7692 SmallVector<unsigned, 1> MismatchedParams;
7693 for (TypoCorrection::const_decl_iterator CDecl = candidate.begin(),
7694 CDeclEnd = candidate.end();
7695 CDecl != CDeclEnd; ++CDecl) {
7696 FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
7698 if (FD && !FD->hasBody() &&
7699 hasSimilarParameters(Context, FD, OriginalFD, MismatchedParams)) {
7700 if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
7701 CXXRecordDecl *Parent = MD->getParent();
7702 if (Parent && Parent->getCanonicalDecl() == ExpectedParent)
7704 } else if (!ExpectedParent) {
7714 ASTContext &Context;
7715 FunctionDecl *OriginalFD;
7716 CXXRecordDecl *ExpectedParent;
7719 } // end anonymous namespace
7721 void Sema::MarkTypoCorrectedFunctionDefinition(const NamedDecl *F) {
7722 TypoCorrectedFunctionDefinitions.insert(F);
7725 /// Generate diagnostics for an invalid function redeclaration.
7727 /// This routine handles generating the diagnostic messages for an invalid
7728 /// function redeclaration, including finding possible similar declarations
7729 /// or performing typo correction if there are no previous declarations with
7732 /// Returns a NamedDecl iff typo correction was performed and substituting in
7733 /// the new declaration name does not cause new errors.
7734 static NamedDecl *DiagnoseInvalidRedeclaration(
7735 Sema &SemaRef, LookupResult &Previous, FunctionDecl *NewFD,
7736 ActOnFDArgs &ExtraArgs, bool IsLocalFriend, Scope *S) {
7737 DeclarationName Name = NewFD->getDeclName();
7738 DeclContext *NewDC = NewFD->getDeclContext();
7739 SmallVector<unsigned, 1> MismatchedParams;
7740 SmallVector<std::pair<FunctionDecl *, unsigned>, 1> NearMatches;
7741 TypoCorrection Correction;
7742 bool IsDefinition = ExtraArgs.D.isFunctionDefinition();
7743 unsigned DiagMsg = IsLocalFriend ? diag::err_no_matching_local_friend
7744 : diag::err_member_decl_does_not_match;
7745 LookupResult Prev(SemaRef, Name, NewFD->getLocation(),
7746 IsLocalFriend ? Sema::LookupLocalFriendName
7747 : Sema::LookupOrdinaryName,
7748 Sema::ForVisibleRedeclaration);
7750 NewFD->setInvalidDecl();
7752 SemaRef.LookupName(Prev, S);
7754 SemaRef.LookupQualifiedName(Prev, NewDC);
7755 assert(!Prev.isAmbiguous() &&
7756 "Cannot have an ambiguity in previous-declaration lookup");
7757 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
7758 if (!Prev.empty()) {
7759 for (LookupResult::iterator Func = Prev.begin(), FuncEnd = Prev.end();
7760 Func != FuncEnd; ++Func) {
7761 FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func);
7763 hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
7764 // Add 1 to the index so that 0 can mean the mismatch didn't
7765 // involve a parameter
7767 MismatchedParams.empty() ? 0 : MismatchedParams.front() + 1;
7768 NearMatches.push_back(std::make_pair(FD, ParamNum));
7771 // If the qualified name lookup yielded nothing, try typo correction
7772 } else if ((Correction = SemaRef.CorrectTypo(
7773 Prev.getLookupNameInfo(), Prev.getLookupKind(), S,
7774 &ExtraArgs.D.getCXXScopeSpec(),
7775 llvm::make_unique<DifferentNameValidatorCCC>(
7776 SemaRef.Context, NewFD, MD ? MD->getParent() : nullptr),
7777 Sema::CTK_ErrorRecovery, IsLocalFriend ? nullptr : NewDC))) {
7778 // Set up everything for the call to ActOnFunctionDeclarator
7779 ExtraArgs.D.SetIdentifier(Correction.getCorrectionAsIdentifierInfo(),
7780 ExtraArgs.D.getIdentifierLoc());
7782 Previous.setLookupName(Correction.getCorrection());
7783 for (TypoCorrection::decl_iterator CDecl = Correction.begin(),
7784 CDeclEnd = Correction.end();
7785 CDecl != CDeclEnd; ++CDecl) {
7786 FunctionDecl *FD = dyn_cast<FunctionDecl>(*CDecl);
7787 if (FD && !FD->hasBody() &&
7788 hasSimilarParameters(SemaRef.Context, FD, NewFD, MismatchedParams)) {
7789 Previous.addDecl(FD);
7792 bool wasRedeclaration = ExtraArgs.D.isRedeclaration();
7795 // Retry building the function declaration with the new previous
7796 // declarations, and with errors suppressed.
7799 Sema::SFINAETrap Trap(SemaRef);
7801 // TODO: Refactor ActOnFunctionDeclarator so that we can call only the
7802 // pieces need to verify the typo-corrected C++ declaration and hopefully
7803 // eliminate the need for the parameter pack ExtraArgs.
7804 Result = SemaRef.ActOnFunctionDeclarator(
7805 ExtraArgs.S, ExtraArgs.D,
7806 Correction.getCorrectionDecl()->getDeclContext(),
7807 NewFD->getTypeSourceInfo(), Previous, ExtraArgs.TemplateParamLists,
7808 ExtraArgs.AddToScope);
7810 if (Trap.hasErrorOccurred())
7815 // Determine which correction we picked.
7816 Decl *Canonical = Result->getCanonicalDecl();
7817 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
7819 if ((*I)->getCanonicalDecl() == Canonical)
7820 Correction.setCorrectionDecl(*I);
7822 // Let Sema know about the correction.
7823 SemaRef.MarkTypoCorrectedFunctionDefinition(Result);
7824 SemaRef.diagnoseTypo(
7826 SemaRef.PDiag(IsLocalFriend
7827 ? diag::err_no_matching_local_friend_suggest
7828 : diag::err_member_decl_does_not_match_suggest)
7829 << Name << NewDC << IsDefinition);
7833 // Pretend the typo correction never occurred
7834 ExtraArgs.D.SetIdentifier(Name.getAsIdentifierInfo(),
7835 ExtraArgs.D.getIdentifierLoc());
7836 ExtraArgs.D.setRedeclaration(wasRedeclaration);
7838 Previous.setLookupName(Name);
7841 SemaRef.Diag(NewFD->getLocation(), DiagMsg)
7842 << Name << NewDC << IsDefinition << NewFD->getLocation();
7844 bool NewFDisConst = false;
7845 if (CXXMethodDecl *NewMD = dyn_cast<CXXMethodDecl>(NewFD))
7846 NewFDisConst = NewMD->isConst();
7848 for (SmallVectorImpl<std::pair<FunctionDecl *, unsigned> >::iterator
7849 NearMatch = NearMatches.begin(), NearMatchEnd = NearMatches.end();
7850 NearMatch != NearMatchEnd; ++NearMatch) {
7851 FunctionDecl *FD = NearMatch->first;
7852 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
7853 bool FDisConst = MD && MD->isConst();
7854 bool IsMember = MD || !IsLocalFriend;
7856 // FIXME: These notes are poorly worded for the local friend case.
7857 if (unsigned Idx = NearMatch->second) {
7858 ParmVarDecl *FDParam = FD->getParamDecl(Idx-1);
7859 SourceLocation Loc = FDParam->getTypeSpecStartLoc();
7860 if (Loc.isInvalid()) Loc = FD->getLocation();
7861 SemaRef.Diag(Loc, IsMember ? diag::note_member_def_close_param_match
7862 : diag::note_local_decl_close_param_match)
7863 << Idx << FDParam->getType()
7864 << NewFD->getParamDecl(Idx - 1)->getType();
7865 } else if (FDisConst != NewFDisConst) {
7866 SemaRef.Diag(FD->getLocation(), diag::note_member_def_close_const_match)
7867 << NewFDisConst << FD->getSourceRange().getEnd();
7869 SemaRef.Diag(FD->getLocation(),
7870 IsMember ? diag::note_member_def_close_match
7871 : diag::note_local_decl_close_match);
7876 static StorageClass getFunctionStorageClass(Sema &SemaRef, Declarator &D) {
7877 switch (D.getDeclSpec().getStorageClassSpec()) {
7878 default: llvm_unreachable("Unknown storage class!");
7879 case DeclSpec::SCS_auto:
7880 case DeclSpec::SCS_register:
7881 case DeclSpec::SCS_mutable:
7882 SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
7883 diag::err_typecheck_sclass_func);
7884 D.getMutableDeclSpec().ClearStorageClassSpecs();
7887 case DeclSpec::SCS_unspecified: break;
7888 case DeclSpec::SCS_extern:
7889 if (D.getDeclSpec().isExternInLinkageSpec())
7892 case DeclSpec::SCS_static: {
7893 if (SemaRef.CurContext->getRedeclContext()->isFunctionOrMethod()) {
7895 // The declaration of an identifier for a function that has
7896 // block scope shall have no explicit storage-class specifier
7897 // other than extern
7898 // See also (C++ [dcl.stc]p4).
7899 SemaRef.Diag(D.getDeclSpec().getStorageClassSpecLoc(),
7900 diag::err_static_block_func);
7905 case DeclSpec::SCS_private_extern: return SC_PrivateExtern;
7908 // No explicit storage class has already been returned
7912 static FunctionDecl* CreateNewFunctionDecl(Sema &SemaRef, Declarator &D,
7913 DeclContext *DC, QualType &R,
7914 TypeSourceInfo *TInfo,
7916 bool &IsVirtualOkay) {
7917 DeclarationNameInfo NameInfo = SemaRef.GetNameForDeclarator(D);
7918 DeclarationName Name = NameInfo.getName();
7920 FunctionDecl *NewFD = nullptr;
7921 bool isInline = D.getDeclSpec().isInlineSpecified();
7923 if (!SemaRef.getLangOpts().CPlusPlus) {
7924 // Determine whether the function was written with a
7925 // prototype. This true when:
7926 // - there is a prototype in the declarator, or
7927 // - the type R of the function is some kind of typedef or other non-
7928 // attributed reference to a type name (which eventually refers to a
7931 (D.isFunctionDeclarator() && D.getFunctionTypeInfo().hasPrototype) ||
7932 (!R->getAsAdjusted<FunctionType>() && R->isFunctionProtoType());
7934 NewFD = FunctionDecl::Create(SemaRef.Context, DC,
7935 D.getLocStart(), NameInfo, R,
7936 TInfo, SC, isInline,
7937 HasPrototype, false);
7938 if (D.isInvalidType())
7939 NewFD->setInvalidDecl();
7944 bool isExplicit = D.getDeclSpec().isExplicitSpecified();
7945 bool isConstexpr = D.getDeclSpec().isConstexprSpecified();
7947 // Check that the return type is not an abstract class type.
7948 // For record types, this is done by the AbstractClassUsageDiagnoser once
7949 // the class has been completely parsed.
7950 if (!DC->isRecord() &&
7951 SemaRef.RequireNonAbstractType(
7952 D.getIdentifierLoc(), R->getAs<FunctionType>()->getReturnType(),
7953 diag::err_abstract_type_in_decl, SemaRef.AbstractReturnType))
7956 if (Name.getNameKind() == DeclarationName::CXXConstructorName) {
7957 // This is a C++ constructor declaration.
7958 assert(DC->isRecord() &&
7959 "Constructors can only be declared in a member context");
7961 R = SemaRef.CheckConstructorDeclarator(D, R, SC);
7962 return CXXConstructorDecl::Create(SemaRef.Context, cast<CXXRecordDecl>(DC),
7963 D.getLocStart(), NameInfo,
7964 R, TInfo, isExplicit, isInline,
7965 /*isImplicitlyDeclared=*/false,
7968 } else if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
7969 // This is a C++ destructor declaration.
7970 if (DC->isRecord()) {
7971 R = SemaRef.CheckDestructorDeclarator(D, R, SC);
7972 CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
7973 CXXDestructorDecl *NewDD = CXXDestructorDecl::Create(
7974 SemaRef.Context, Record,
7976 NameInfo, R, TInfo, isInline,
7977 /*isImplicitlyDeclared=*/false);
7979 // If the class is complete, then we now create the implicit exception
7980 // specification. If the class is incomplete or dependent, we can't do
7982 if (SemaRef.getLangOpts().CPlusPlus11 && !Record->isDependentType() &&
7983 Record->getDefinition() && !Record->isBeingDefined() &&
7984 R->getAs<FunctionProtoType>()->getExceptionSpecType() == EST_None) {
7985 SemaRef.AdjustDestructorExceptionSpec(Record, NewDD);
7988 IsVirtualOkay = true;
7992 SemaRef.Diag(D.getIdentifierLoc(), diag::err_destructor_not_member);
7995 // Create a FunctionDecl to satisfy the function definition parsing
7997 return FunctionDecl::Create(SemaRef.Context, DC,
7999 D.getIdentifierLoc(), Name, R, TInfo,
8001 /*hasPrototype=*/true, isConstexpr);
8004 } else if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName) {
8005 if (!DC->isRecord()) {
8006 SemaRef.Diag(D.getIdentifierLoc(),
8007 diag::err_conv_function_not_member);
8011 SemaRef.CheckConversionDeclarator(D, R, SC);
8012 IsVirtualOkay = true;
8013 return CXXConversionDecl::Create(SemaRef.Context, cast<CXXRecordDecl>(DC),
8014 D.getLocStart(), NameInfo,
8015 R, TInfo, isInline, isExplicit,
8016 isConstexpr, SourceLocation());
8018 } else if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
8019 SemaRef.CheckDeductionGuideDeclarator(D, R, SC);
8021 return CXXDeductionGuideDecl::Create(SemaRef.Context, DC, D.getLocStart(),
8022 isExplicit, NameInfo, R, TInfo,
8024 } else if (DC->isRecord()) {
8025 // If the name of the function is the same as the name of the record,
8026 // then this must be an invalid constructor that has a return type.
8027 // (The parser checks for a return type and makes the declarator a
8028 // constructor if it has no return type).
8029 if (Name.getAsIdentifierInfo() &&
8030 Name.getAsIdentifierInfo() == cast<CXXRecordDecl>(DC)->getIdentifier()){
8031 SemaRef.Diag(D.getIdentifierLoc(), diag::err_constructor_return_type)
8032 << SourceRange(D.getDeclSpec().getTypeSpecTypeLoc())
8033 << SourceRange(D.getIdentifierLoc());
8037 // This is a C++ method declaration.
8038 CXXMethodDecl *Ret = CXXMethodDecl::Create(SemaRef.Context,
8039 cast<CXXRecordDecl>(DC),
8040 D.getLocStart(), NameInfo, R,
8041 TInfo, SC, isInline,
8042 isConstexpr, SourceLocation());
8043 IsVirtualOkay = !Ret->isStatic();
8047 SemaRef.getLangOpts().CPlusPlus && D.getDeclSpec().isFriendSpecified();
8048 if (!isFriend && SemaRef.CurContext->isRecord())
8051 // Determine whether the function was written with a
8052 // prototype. This true when:
8053 // - we're in C++ (where every function has a prototype),
8054 return FunctionDecl::Create(SemaRef.Context, DC,
8056 NameInfo, R, TInfo, SC, isInline,
8057 true/*HasPrototype*/, isConstexpr);
8061 enum OpenCLParamType {
8065 InvalidAddrSpacePtrKernelParam,
8070 static bool isOpenCLSizeDependentType(ASTContext &C, QualType Ty) {
8071 // Size dependent types are just typedefs to normal integer types
8072 // (e.g. unsigned long), so we cannot distinguish them from other typedefs to
8073 // integers other than by their names.
8074 StringRef SizeTypeNames[] = {"size_t", "intptr_t", "uintptr_t", "ptrdiff_t"};
8076 // Remove typedefs one by one until we reach a typedef
8077 // for a size dependent type.
8078 QualType DesugaredTy = Ty;
8080 ArrayRef<StringRef> Names(SizeTypeNames);
8082 std::find(Names.begin(), Names.end(), DesugaredTy.getAsString());
8083 if (Names.end() != Match)
8087 DesugaredTy = Ty.getSingleStepDesugaredType(C);
8088 } while (DesugaredTy != Ty);
8093 static OpenCLParamType getOpenCLKernelParameterType(Sema &S, QualType PT) {
8094 if (PT->isPointerType()) {
8095 QualType PointeeType = PT->getPointeeType();
8096 if (PointeeType->isPointerType())
8097 return PtrPtrKernelParam;
8098 if (PointeeType.getAddressSpace() == LangAS::opencl_generic ||
8099 PointeeType.getAddressSpace() == LangAS::opencl_private ||
8100 PointeeType.getAddressSpace() == LangAS::Default)
8101 return InvalidAddrSpacePtrKernelParam;
8102 return PtrKernelParam;
8105 // OpenCL v1.2 s6.9.k:
8106 // Arguments to kernel functions in a program cannot be declared with the
8107 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
8108 // uintptr_t or a struct and/or union that contain fields declared to be one
8109 // of these built-in scalar types.
8110 if (isOpenCLSizeDependentType(S.getASTContext(), PT))
8111 return InvalidKernelParam;
8113 if (PT->isImageType())
8114 return PtrKernelParam;
8116 if (PT->isBooleanType() || PT->isEventT() || PT->isReserveIDT())
8117 return InvalidKernelParam;
8119 // OpenCL extension spec v1.2 s9.5:
8120 // This extension adds support for half scalar and vector types as built-in
8121 // types that can be used for arithmetic operations, conversions etc.
8122 if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16") && PT->isHalfType())
8123 return InvalidKernelParam;
8125 if (PT->isRecordType())
8126 return RecordKernelParam;
8128 // Look into an array argument to check if it has a forbidden type.
8129 if (PT->isArrayType()) {
8130 const Type *UnderlyingTy = PT->getPointeeOrArrayElementType();
8131 // Call ourself to check an underlying type of an array. Since the
8132 // getPointeeOrArrayElementType returns an innermost type which is not an
8133 // array, this recusive call only happens once.
8134 return getOpenCLKernelParameterType(S, QualType(UnderlyingTy, 0));
8137 return ValidKernelParam;
8140 static void checkIsValidOpenCLKernelParameter(
8144 llvm::SmallPtrSetImpl<const Type *> &ValidTypes) {
8145 QualType PT = Param->getType();
8147 // Cache the valid types we encounter to avoid rechecking structs that are
8149 if (ValidTypes.count(PT.getTypePtr()))
8152 switch (getOpenCLKernelParameterType(S, PT)) {
8153 case PtrPtrKernelParam:
8154 // OpenCL v1.2 s6.9.a:
8155 // A kernel function argument cannot be declared as a
8156 // pointer to a pointer type.
8157 S.Diag(Param->getLocation(), diag::err_opencl_ptrptr_kernel_param);
8161 case InvalidAddrSpacePtrKernelParam:
8162 // OpenCL v1.0 s6.5:
8163 // __kernel function arguments declared to be a pointer of a type can point
8164 // to one of the following address spaces only : __global, __local or
8166 S.Diag(Param->getLocation(), diag::err_kernel_arg_address_space);
8170 // OpenCL v1.2 s6.9.k:
8171 // Arguments to kernel functions in a program cannot be declared with the
8172 // built-in scalar types bool, half, size_t, ptrdiff_t, intptr_t, and
8173 // uintptr_t or a struct and/or union that contain fields declared to be
8174 // one of these built-in scalar types.
8176 case InvalidKernelParam:
8177 // OpenCL v1.2 s6.8 n:
8178 // A kernel function argument cannot be declared
8180 // Do not diagnose half type since it is diagnosed as invalid argument
8181 // type for any function elsewhere.
8182 if (!PT->isHalfType()) {
8183 S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
8185 // Explain what typedefs are involved.
8186 const TypedefType *Typedef = nullptr;
8187 while ((Typedef = PT->getAs<TypedefType>())) {
8188 SourceLocation Loc = Typedef->getDecl()->getLocation();
8189 // SourceLocation may be invalid for a built-in type.
8191 S.Diag(Loc, diag::note_entity_declared_at) << PT;
8192 PT = Typedef->desugar();
8199 case PtrKernelParam:
8200 case ValidKernelParam:
8201 ValidTypes.insert(PT.getTypePtr());
8204 case RecordKernelParam:
8208 // Track nested structs we will inspect
8209 SmallVector<const Decl *, 4> VisitStack;
8211 // Track where we are in the nested structs. Items will migrate from
8212 // VisitStack to HistoryStack as we do the DFS for bad field.
8213 SmallVector<const FieldDecl *, 4> HistoryStack;
8214 HistoryStack.push_back(nullptr);
8216 // At this point we already handled everything except of a RecordType or
8217 // an ArrayType of a RecordType.
8218 assert((PT->isArrayType() || PT->isRecordType()) && "Unexpected type.");
8219 const RecordType *RecTy =
8220 PT->getPointeeOrArrayElementType()->getAs<RecordType>();
8221 const RecordDecl *OrigRecDecl = RecTy->getDecl();
8223 VisitStack.push_back(RecTy->getDecl());
8224 assert(VisitStack.back() && "First decl null?");
8227 const Decl *Next = VisitStack.pop_back_val();
8229 assert(!HistoryStack.empty());
8230 // Found a marker, we have gone up a level
8231 if (const FieldDecl *Hist = HistoryStack.pop_back_val())
8232 ValidTypes.insert(Hist->getType().getTypePtr());
8237 // Adds everything except the original parameter declaration (which is not a
8238 // field itself) to the history stack.
8239 const RecordDecl *RD;
8240 if (const FieldDecl *Field = dyn_cast<FieldDecl>(Next)) {
8241 HistoryStack.push_back(Field);
8243 QualType FieldTy = Field->getType();
8244 // Other field types (known to be valid or invalid) are handled while we
8245 // walk around RecordDecl::fields().
8246 assert((FieldTy->isArrayType() || FieldTy->isRecordType()) &&
8247 "Unexpected type.");
8248 const Type *FieldRecTy = FieldTy->getPointeeOrArrayElementType();
8250 RD = FieldRecTy->castAs<RecordType>()->getDecl();
8252 RD = cast<RecordDecl>(Next);
8255 // Add a null marker so we know when we've gone back up a level
8256 VisitStack.push_back(nullptr);
8258 for (const auto *FD : RD->fields()) {
8259 QualType QT = FD->getType();
8261 if (ValidTypes.count(QT.getTypePtr()))
8264 OpenCLParamType ParamType = getOpenCLKernelParameterType(S, QT);
8265 if (ParamType == ValidKernelParam)
8268 if (ParamType == RecordKernelParam) {
8269 VisitStack.push_back(FD);
8273 // OpenCL v1.2 s6.9.p:
8274 // Arguments to kernel functions that are declared to be a struct or union
8275 // do not allow OpenCL objects to be passed as elements of the struct or
8277 if (ParamType == PtrKernelParam || ParamType == PtrPtrKernelParam ||
8278 ParamType == InvalidAddrSpacePtrKernelParam) {
8279 S.Diag(Param->getLocation(),
8280 diag::err_record_with_pointers_kernel_param)
8281 << PT->isUnionType()
8284 S.Diag(Param->getLocation(), diag::err_bad_kernel_param_type) << PT;
8287 S.Diag(OrigRecDecl->getLocation(), diag::note_within_field_of_type)
8288 << OrigRecDecl->getDeclName();
8290 // We have an error, now let's go back up through history and show where
8291 // the offending field came from
8292 for (ArrayRef<const FieldDecl *>::const_iterator
8293 I = HistoryStack.begin() + 1,
8294 E = HistoryStack.end();
8296 const FieldDecl *OuterField = *I;
8297 S.Diag(OuterField->getLocation(), diag::note_within_field_of_type)
8298 << OuterField->getType();
8301 S.Diag(FD->getLocation(), diag::note_illegal_field_declared_here)
8302 << QT->isPointerType()
8307 } while (!VisitStack.empty());
8310 /// Find the DeclContext in which a tag is implicitly declared if we see an
8311 /// elaborated type specifier in the specified context, and lookup finds
8313 static DeclContext *getTagInjectionContext(DeclContext *DC) {
8314 while (!DC->isFileContext() && !DC->isFunctionOrMethod())
8315 DC = DC->getParent();
8319 /// Find the Scope in which a tag is implicitly declared if we see an
8320 /// elaborated type specifier in the specified context, and lookup finds
8322 static Scope *getTagInjectionScope(Scope *S, const LangOptions &LangOpts) {
8323 while (S->isClassScope() ||
8324 (LangOpts.CPlusPlus &&
8325 S->isFunctionPrototypeScope()) ||
8326 ((S->getFlags() & Scope::DeclScope) == 0) ||
8327 (S->getEntity() && S->getEntity()->isTransparentContext()))
8333 Sema::ActOnFunctionDeclarator(Scope *S, Declarator &D, DeclContext *DC,
8334 TypeSourceInfo *TInfo, LookupResult &Previous,
8335 MultiTemplateParamsArg TemplateParamLists,
8337 QualType R = TInfo->getType();
8339 assert(R->isFunctionType());
8341 // TODO: consider using NameInfo for diagnostic.
8342 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
8343 DeclarationName Name = NameInfo.getName();
8344 StorageClass SC = getFunctionStorageClass(*this, D);
8346 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
8347 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
8348 diag::err_invalid_thread)
8349 << DeclSpec::getSpecifierName(TSCS);
8351 if (D.isFirstDeclarationOfMember())
8352 adjustMemberFunctionCC(R, D.isStaticMember(), D.isCtorOrDtor(),
8353 D.getIdentifierLoc());
8355 bool isFriend = false;
8356 FunctionTemplateDecl *FunctionTemplate = nullptr;
8357 bool isMemberSpecialization = false;
8358 bool isFunctionTemplateSpecialization = false;
8360 bool isDependentClassScopeExplicitSpecialization = false;
8361 bool HasExplicitTemplateArgs = false;
8362 TemplateArgumentListInfo TemplateArgs;
8364 bool isVirtualOkay = false;
8366 DeclContext *OriginalDC = DC;
8367 bool IsLocalExternDecl = adjustContextForLocalExternDecl(DC);
8369 FunctionDecl *NewFD = CreateNewFunctionDecl(*this, D, DC, R, TInfo, SC,
8371 if (!NewFD) return nullptr;
8373 if (OriginalLexicalContext && OriginalLexicalContext->isObjCContainer())
8374 NewFD->setTopLevelDeclInObjCContainer();
8376 // Set the lexical context. If this is a function-scope declaration, or has a
8377 // C++ scope specifier, or is the object of a friend declaration, the lexical
8378 // context will be different from the semantic context.
8379 NewFD->setLexicalDeclContext(CurContext);
8381 if (IsLocalExternDecl)
8382 NewFD->setLocalExternDecl();
8384 if (getLangOpts().CPlusPlus) {
8385 bool isInline = D.getDeclSpec().isInlineSpecified();
8386 bool isVirtual = D.getDeclSpec().isVirtualSpecified();
8387 bool isExplicit = D.getDeclSpec().isExplicitSpecified();
8388 bool isConstexpr = D.getDeclSpec().isConstexprSpecified();
8389 isFriend = D.getDeclSpec().isFriendSpecified();
8390 if (isFriend && !isInline && D.isFunctionDefinition()) {
8391 // C++ [class.friend]p5
8392 // A function can be defined in a friend declaration of a
8393 // class . . . . Such a function is implicitly inline.
8394 NewFD->setImplicitlyInline();
8397 // If this is a method defined in an __interface, and is not a constructor
8398 // or an overloaded operator, then set the pure flag (isVirtual will already
8400 if (const CXXRecordDecl *Parent =
8401 dyn_cast<CXXRecordDecl>(NewFD->getDeclContext())) {
8402 if (Parent->isInterface() && cast<CXXMethodDecl>(NewFD)->isUserProvided())
8403 NewFD->setPure(true);
8405 // C++ [class.union]p2
8406 // A union can have member functions, but not virtual functions.
8407 if (isVirtual && Parent->isUnion())
8408 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_virtual_in_union);
8411 SetNestedNameSpecifier(NewFD, D);
8412 isMemberSpecialization = false;
8413 isFunctionTemplateSpecialization = false;
8414 if (D.isInvalidType())
8415 NewFD->setInvalidDecl();
8417 // Match up the template parameter lists with the scope specifier, then
8418 // determine whether we have a template or a template specialization.
8419 bool Invalid = false;
8420 if (TemplateParameterList *TemplateParams =
8421 MatchTemplateParametersToScopeSpecifier(
8422 D.getDeclSpec().getLocStart(), D.getIdentifierLoc(),
8423 D.getCXXScopeSpec(),
8424 D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId
8425 ? D.getName().TemplateId
8427 TemplateParamLists, isFriend, isMemberSpecialization,
8429 if (TemplateParams->size() > 0) {
8430 // This is a function template
8432 // Check that we can declare a template here.
8433 if (CheckTemplateDeclScope(S, TemplateParams))
8434 NewFD->setInvalidDecl();
8436 // A destructor cannot be a template.
8437 if (Name.getNameKind() == DeclarationName::CXXDestructorName) {
8438 Diag(NewFD->getLocation(), diag::err_destructor_template);
8439 NewFD->setInvalidDecl();
8442 // If we're adding a template to a dependent context, we may need to
8443 // rebuilding some of the types used within the template parameter list,
8444 // now that we know what the current instantiation is.
8445 if (DC->isDependentContext()) {
8446 ContextRAII SavedContext(*this, DC);
8447 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
8451 FunctionTemplate = FunctionTemplateDecl::Create(Context, DC,
8452 NewFD->getLocation(),
8453 Name, TemplateParams,
8455 FunctionTemplate->setLexicalDeclContext(CurContext);
8456 NewFD->setDescribedFunctionTemplate(FunctionTemplate);
8458 // For source fidelity, store the other template param lists.
8459 if (TemplateParamLists.size() > 1) {
8460 NewFD->setTemplateParameterListsInfo(Context,
8461 TemplateParamLists.drop_back(1));
8464 // This is a function template specialization.
8465 isFunctionTemplateSpecialization = true;
8466 // For source fidelity, store all the template param lists.
8467 if (TemplateParamLists.size() > 0)
8468 NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
8470 // C++0x [temp.expl.spec]p20 forbids "template<> friend void foo(int);".
8472 // We want to remove the "template<>", found here.
8473 SourceRange RemoveRange = TemplateParams->getSourceRange();
8475 // If we remove the template<> and the name is not a
8476 // template-id, we're actually silently creating a problem:
8477 // the friend declaration will refer to an untemplated decl,
8478 // and clearly the user wants a template specialization. So
8479 // we need to insert '<>' after the name.
8480 SourceLocation InsertLoc;
8481 if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
8482 InsertLoc = D.getName().getSourceRange().getEnd();
8483 InsertLoc = getLocForEndOfToken(InsertLoc);
8486 Diag(D.getIdentifierLoc(), diag::err_template_spec_decl_friend)
8487 << Name << RemoveRange
8488 << FixItHint::CreateRemoval(RemoveRange)
8489 << FixItHint::CreateInsertion(InsertLoc, "<>");
8494 // All template param lists were matched against the scope specifier:
8495 // this is NOT (an explicit specialization of) a template.
8496 if (TemplateParamLists.size() > 0)
8497 // For source fidelity, store all the template param lists.
8498 NewFD->setTemplateParameterListsInfo(Context, TemplateParamLists);
8502 NewFD->setInvalidDecl();
8503 if (FunctionTemplate)
8504 FunctionTemplate->setInvalidDecl();
8507 // C++ [dcl.fct.spec]p5:
8508 // The virtual specifier shall only be used in declarations of
8509 // nonstatic class member functions that appear within a
8510 // member-specification of a class declaration; see 10.3.
8512 if (isVirtual && !NewFD->isInvalidDecl()) {
8513 if (!isVirtualOkay) {
8514 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8515 diag::err_virtual_non_function);
8516 } else if (!CurContext->isRecord()) {
8517 // 'virtual' was specified outside of the class.
8518 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8519 diag::err_virtual_out_of_class)
8520 << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
8521 } else if (NewFD->getDescribedFunctionTemplate()) {
8522 // C++ [temp.mem]p3:
8523 // A member function template shall not be virtual.
8524 Diag(D.getDeclSpec().getVirtualSpecLoc(),
8525 diag::err_virtual_member_function_template)
8526 << FixItHint::CreateRemoval(D.getDeclSpec().getVirtualSpecLoc());
8528 // Okay: Add virtual to the method.
8529 NewFD->setVirtualAsWritten(true);
8532 if (getLangOpts().CPlusPlus14 &&
8533 NewFD->getReturnType()->isUndeducedType())
8534 Diag(D.getDeclSpec().getVirtualSpecLoc(), diag::err_auto_fn_virtual);
8537 if (getLangOpts().CPlusPlus14 &&
8538 (NewFD->isDependentContext() ||
8539 (isFriend && CurContext->isDependentContext())) &&
8540 NewFD->getReturnType()->isUndeducedType()) {
8541 // If the function template is referenced directly (for instance, as a
8542 // member of the current instantiation), pretend it has a dependent type.
8543 // This is not really justified by the standard, but is the only sane
8545 // FIXME: For a friend function, we have not marked the function as being
8546 // a friend yet, so 'isDependentContext' on the FD doesn't work.
8547 const FunctionProtoType *FPT =
8548 NewFD->getType()->castAs<FunctionProtoType>();
8550 SubstAutoType(FPT->getReturnType(), Context.DependentTy);
8551 NewFD->setType(Context.getFunctionType(Result, FPT->getParamTypes(),
8552 FPT->getExtProtoInfo()));
8555 // C++ [dcl.fct.spec]p3:
8556 // The inline specifier shall not appear on a block scope function
8558 if (isInline && !NewFD->isInvalidDecl()) {
8559 if (CurContext->isFunctionOrMethod()) {
8560 // 'inline' is not allowed on block scope function declaration.
8561 Diag(D.getDeclSpec().getInlineSpecLoc(),
8562 diag::err_inline_declaration_block_scope) << Name
8563 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
8567 // C++ [dcl.fct.spec]p6:
8568 // The explicit specifier shall be used only in the declaration of a
8569 // constructor or conversion function within its class definition;
8570 // see 12.3.1 and 12.3.2.
8571 if (isExplicit && !NewFD->isInvalidDecl() &&
8572 !isa<CXXDeductionGuideDecl>(NewFD)) {
8573 if (!CurContext->isRecord()) {
8574 // 'explicit' was specified outside of the class.
8575 Diag(D.getDeclSpec().getExplicitSpecLoc(),
8576 diag::err_explicit_out_of_class)
8577 << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc());
8578 } else if (!isa<CXXConstructorDecl>(NewFD) &&
8579 !isa<CXXConversionDecl>(NewFD)) {
8580 // 'explicit' was specified on a function that wasn't a constructor
8581 // or conversion function.
8582 Diag(D.getDeclSpec().getExplicitSpecLoc(),
8583 diag::err_explicit_non_ctor_or_conv_function)
8584 << FixItHint::CreateRemoval(D.getDeclSpec().getExplicitSpecLoc());
8589 // C++11 [dcl.constexpr]p2: constexpr functions and constexpr constructors
8590 // are implicitly inline.
8591 NewFD->setImplicitlyInline();
8593 // C++11 [dcl.constexpr]p3: functions declared constexpr are required to
8594 // be either constructors or to return a literal type. Therefore,
8595 // destructors cannot be declared constexpr.
8596 if (isa<CXXDestructorDecl>(NewFD))
8597 Diag(D.getDeclSpec().getConstexprSpecLoc(), diag::err_constexpr_dtor);
8600 // If __module_private__ was specified, mark the function accordingly.
8601 if (D.getDeclSpec().isModulePrivateSpecified()) {
8602 if (isFunctionTemplateSpecialization) {
8603 SourceLocation ModulePrivateLoc
8604 = D.getDeclSpec().getModulePrivateSpecLoc();
8605 Diag(ModulePrivateLoc, diag::err_module_private_specialization)
8607 << FixItHint::CreateRemoval(ModulePrivateLoc);
8609 NewFD->setModulePrivate();
8610 if (FunctionTemplate)
8611 FunctionTemplate->setModulePrivate();
8616 if (FunctionTemplate) {
8617 FunctionTemplate->setObjectOfFriendDecl();
8618 FunctionTemplate->setAccess(AS_public);
8620 NewFD->setObjectOfFriendDecl();
8621 NewFD->setAccess(AS_public);
8624 // If a function is defined as defaulted or deleted, mark it as such now.
8625 // FIXME: Does this ever happen? ActOnStartOfFunctionDef forces the function
8626 // definition kind to FDK_Definition.
8627 switch (D.getFunctionDefinitionKind()) {
8628 case FDK_Declaration:
8629 case FDK_Definition:
8633 NewFD->setDefaulted();
8637 NewFD->setDeletedAsWritten();
8641 if (isa<CXXMethodDecl>(NewFD) && DC == CurContext &&
8642 D.isFunctionDefinition()) {
8643 // C++ [class.mfct]p2:
8644 // A member function may be defined (8.4) in its class definition, in
8645 // which case it is an inline member function (7.1.2)
8646 NewFD->setImplicitlyInline();
8649 if (SC == SC_Static && isa<CXXMethodDecl>(NewFD) &&
8650 !CurContext->isRecord()) {
8651 // C++ [class.static]p1:
8652 // A data or function member of a class may be declared static
8653 // in a class definition, in which case it is a static member of
8656 // Complain about the 'static' specifier if it's on an out-of-line
8657 // member function definition.
8658 Diag(D.getDeclSpec().getStorageClassSpecLoc(),
8659 diag::err_static_out_of_line)
8660 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
8663 // C++11 [except.spec]p15:
8664 // A deallocation function with no exception-specification is treated
8665 // as if it were specified with noexcept(true).
8666 const FunctionProtoType *FPT = R->getAs<FunctionProtoType>();
8667 if ((Name.getCXXOverloadedOperator() == OO_Delete ||
8668 Name.getCXXOverloadedOperator() == OO_Array_Delete) &&
8669 getLangOpts().CPlusPlus11 && FPT && !FPT->hasExceptionSpec())
8670 NewFD->setType(Context.getFunctionType(
8671 FPT->getReturnType(), FPT->getParamTypes(),
8672 FPT->getExtProtoInfo().withExceptionSpec(EST_BasicNoexcept)));
8675 // Filter out previous declarations that don't match the scope.
8676 FilterLookupForScope(Previous, OriginalDC, S, shouldConsiderLinkage(NewFD),
8677 D.getCXXScopeSpec().isNotEmpty() ||
8678 isMemberSpecialization ||
8679 isFunctionTemplateSpecialization);
8681 // Handle GNU asm-label extension (encoded as an attribute).
8682 if (Expr *E = (Expr*) D.getAsmLabel()) {
8683 // The parser guarantees this is a string.
8684 StringLiteral *SE = cast<StringLiteral>(E);
8685 NewFD->addAttr(::new (Context) AsmLabelAttr(SE->getStrTokenLoc(0), Context,
8686 SE->getString(), 0));
8687 } else if (!ExtnameUndeclaredIdentifiers.empty()) {
8688 llvm::DenseMap<IdentifierInfo*,AsmLabelAttr*>::iterator I =
8689 ExtnameUndeclaredIdentifiers.find(NewFD->getIdentifier());
8690 if (I != ExtnameUndeclaredIdentifiers.end()) {
8691 if (isDeclExternC(NewFD)) {
8692 NewFD->addAttr(I->second);
8693 ExtnameUndeclaredIdentifiers.erase(I);
8695 Diag(NewFD->getLocation(), diag::warn_redefine_extname_not_applied)
8696 << /*Variable*/0 << NewFD;
8700 // Copy the parameter declarations from the declarator D to the function
8701 // declaration NewFD, if they are available. First scavenge them into Params.
8702 SmallVector<ParmVarDecl*, 16> Params;
8704 if (D.isFunctionDeclarator(FTIIdx)) {
8705 DeclaratorChunk::FunctionTypeInfo &FTI = D.getTypeObject(FTIIdx).Fun;
8707 // Check for C99 6.7.5.3p10 - foo(void) is a non-varargs
8708 // function that takes no arguments, not a function that takes a
8709 // single void argument.
8710 // We let through "const void" here because Sema::GetTypeForDeclarator
8711 // already checks for that case.
8712 if (FTIHasNonVoidParameters(FTI) && FTI.Params[0].Param) {
8713 for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
8714 ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
8715 assert(Param->getDeclContext() != NewFD && "Was set before ?");
8716 Param->setDeclContext(NewFD);
8717 Params.push_back(Param);
8719 if (Param->isInvalidDecl())
8720 NewFD->setInvalidDecl();
8724 if (!getLangOpts().CPlusPlus) {
8725 // In C, find all the tag declarations from the prototype and move them
8726 // into the function DeclContext. Remove them from the surrounding tag
8727 // injection context of the function, which is typically but not always
8729 DeclContext *PrototypeTagContext =
8730 getTagInjectionContext(NewFD->getLexicalDeclContext());
8731 for (NamedDecl *NonParmDecl : FTI.getDeclsInPrototype()) {
8732 auto *TD = dyn_cast<TagDecl>(NonParmDecl);
8734 // We don't want to reparent enumerators. Look at their parent enum
8737 if (auto *ECD = dyn_cast<EnumConstantDecl>(NonParmDecl))
8738 TD = cast<EnumDecl>(ECD->getDeclContext());
8742 DeclContext *TagDC = TD->getLexicalDeclContext();
8743 if (!TagDC->containsDecl(TD))
8745 TagDC->removeDecl(TD);
8746 TD->setDeclContext(NewFD);
8749 // Preserve the lexical DeclContext if it is not the surrounding tag
8750 // injection context of the FD. In this example, the semantic context of
8751 // E will be f and the lexical context will be S, while both the
8752 // semantic and lexical contexts of S will be f:
8753 // void f(struct S { enum E { a } f; } s);
8754 if (TagDC != PrototypeTagContext)
8755 TD->setLexicalDeclContext(TagDC);
8758 } else if (const FunctionProtoType *FT = R->getAs<FunctionProtoType>()) {
8759 // When we're declaring a function with a typedef, typeof, etc as in the
8760 // following example, we'll need to synthesize (unnamed)
8761 // parameters for use in the declaration.
8764 // typedef void fn(int);
8768 // Synthesize a parameter for each argument type.
8769 for (const auto &AI : FT->param_types()) {
8770 ParmVarDecl *Param =
8771 BuildParmVarDeclForTypedef(NewFD, D.getIdentifierLoc(), AI);
8772 Param->setScopeInfo(0, Params.size());
8773 Params.push_back(Param);
8776 assert(R->isFunctionNoProtoType() && NewFD->getNumParams() == 0 &&
8777 "Should not need args for typedef of non-prototype fn");
8780 // Finally, we know we have the right number of parameters, install them.
8781 NewFD->setParams(Params);
8783 if (D.getDeclSpec().isNoreturnSpecified())
8785 ::new(Context) C11NoReturnAttr(D.getDeclSpec().getNoreturnSpecLoc(),
8788 // Functions returning a variably modified type violate C99 6.7.5.2p2
8789 // because all functions have linkage.
8790 if (!NewFD->isInvalidDecl() &&
8791 NewFD->getReturnType()->isVariablyModifiedType()) {
8792 Diag(NewFD->getLocation(), diag::err_vm_func_decl);
8793 NewFD->setInvalidDecl();
8796 // Apply an implicit SectionAttr if '#pragma clang section text' is active
8797 if (PragmaClangTextSection.Valid && D.isFunctionDefinition() &&
8798 !NewFD->hasAttr<SectionAttr>()) {
8799 NewFD->addAttr(PragmaClangTextSectionAttr::CreateImplicit(Context,
8800 PragmaClangTextSection.SectionName,
8801 PragmaClangTextSection.PragmaLocation));
8804 // Apply an implicit SectionAttr if #pragma code_seg is active.
8805 if (CodeSegStack.CurrentValue && D.isFunctionDefinition() &&
8806 !NewFD->hasAttr<SectionAttr>()) {
8808 SectionAttr::CreateImplicit(Context, SectionAttr::Declspec_allocate,
8809 CodeSegStack.CurrentValue->getString(),
8810 CodeSegStack.CurrentPragmaLocation));
8811 if (UnifySection(CodeSegStack.CurrentValue->getString(),
8812 ASTContext::PSF_Implicit | ASTContext::PSF_Execute |
8813 ASTContext::PSF_Read,
8815 NewFD->dropAttr<SectionAttr>();
8818 // Apply an implicit CodeSegAttr from class declspec or
8819 // apply an implicit SectionAttr from #pragma code_seg if active.
8820 if (!NewFD->hasAttr<CodeSegAttr>()) {
8821 if (Attr *SAttr = getImplicitCodeSegOrSectionAttrForFunction(NewFD,
8822 D.isFunctionDefinition())) {
8823 NewFD->addAttr(SAttr);
8827 // Handle attributes.
8828 ProcessDeclAttributes(S, NewFD, D);
8830 if (getLangOpts().OpenCL) {
8831 // OpenCL v1.1 s6.5: Using an address space qualifier in a function return
8832 // type declaration will generate a compilation error.
8833 LangAS AddressSpace = NewFD->getReturnType().getAddressSpace();
8834 if (AddressSpace != LangAS::Default) {
8835 Diag(NewFD->getLocation(),
8836 diag::err_opencl_return_value_with_address_space);
8837 NewFD->setInvalidDecl();
8841 if (!getLangOpts().CPlusPlus) {
8842 // Perform semantic checking on the function declaration.
8843 if (!NewFD->isInvalidDecl() && NewFD->isMain())
8844 CheckMain(NewFD, D.getDeclSpec());
8846 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
8847 CheckMSVCRTEntryPoint(NewFD);
8849 if (!NewFD->isInvalidDecl())
8850 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
8851 isMemberSpecialization));
8852 else if (!Previous.empty())
8853 // Recover gracefully from an invalid redeclaration.
8854 D.setRedeclaration(true);
8855 assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
8856 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
8857 "previous declaration set still overloaded");
8859 // Diagnose no-prototype function declarations with calling conventions that
8860 // don't support variadic calls. Only do this in C and do it after merging
8861 // possibly prototyped redeclarations.
8862 const FunctionType *FT = NewFD->getType()->castAs<FunctionType>();
8863 if (isa<FunctionNoProtoType>(FT) && !D.isFunctionDefinition()) {
8864 CallingConv CC = FT->getExtInfo().getCC();
8865 if (!supportsVariadicCall(CC)) {
8866 // Windows system headers sometimes accidentally use stdcall without
8867 // (void) parameters, so we relax this to a warning.
8869 CC == CC_X86StdCall ? diag::warn_cconv_knr : diag::err_cconv_knr;
8870 Diag(NewFD->getLocation(), DiagID)
8871 << FunctionType::getNameForCallConv(CC);
8875 // C++11 [replacement.functions]p3:
8876 // The program's definitions shall not be specified as inline.
8878 // N.B. We diagnose declarations instead of definitions per LWG issue 2340.
8880 // Suppress the diagnostic if the function is __attribute__((used)), since
8881 // that forces an external definition to be emitted.
8882 if (D.getDeclSpec().isInlineSpecified() &&
8883 NewFD->isReplaceableGlobalAllocationFunction() &&
8884 !NewFD->hasAttr<UsedAttr>())
8885 Diag(D.getDeclSpec().getInlineSpecLoc(),
8886 diag::ext_operator_new_delete_declared_inline)
8887 << NewFD->getDeclName();
8889 // If the declarator is a template-id, translate the parser's template
8890 // argument list into our AST format.
8891 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
8892 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
8893 TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
8894 TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
8895 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId->getTemplateArgs(),
8896 TemplateId->NumArgs);
8897 translateTemplateArguments(TemplateArgsPtr,
8900 HasExplicitTemplateArgs = true;
8902 if (NewFD->isInvalidDecl()) {
8903 HasExplicitTemplateArgs = false;
8904 } else if (FunctionTemplate) {
8905 // Function template with explicit template arguments.
8906 Diag(D.getIdentifierLoc(), diag::err_function_template_partial_spec)
8907 << SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc);
8909 HasExplicitTemplateArgs = false;
8911 assert((isFunctionTemplateSpecialization ||
8912 D.getDeclSpec().isFriendSpecified()) &&
8913 "should have a 'template<>' for this decl");
8914 // "friend void foo<>(int);" is an implicit specialization decl.
8915 isFunctionTemplateSpecialization = true;
8917 } else if (isFriend && isFunctionTemplateSpecialization) {
8918 // This combination is only possible in a recovery case; the user
8919 // wrote something like:
8920 // template <> friend void foo(int);
8921 // which we're recovering from as if the user had written:
8922 // friend void foo<>(int);
8923 // Go ahead and fake up a template id.
8924 HasExplicitTemplateArgs = true;
8925 TemplateArgs.setLAngleLoc(D.getIdentifierLoc());
8926 TemplateArgs.setRAngleLoc(D.getIdentifierLoc());
8929 // We do not add HD attributes to specializations here because
8930 // they may have different constexpr-ness compared to their
8931 // templates and, after maybeAddCUDAHostDeviceAttrs() is applied,
8932 // may end up with different effective targets. Instead, a
8933 // specialization inherits its target attributes from its template
8934 // in the CheckFunctionTemplateSpecialization() call below.
8935 if (getLangOpts().CUDA & !isFunctionTemplateSpecialization)
8936 maybeAddCUDAHostDeviceAttrs(NewFD, Previous);
8938 // If it's a friend (and only if it's a friend), it's possible
8939 // that either the specialized function type or the specialized
8940 // template is dependent, and therefore matching will fail. In
8941 // this case, don't check the specialization yet.
8942 bool InstantiationDependent = false;
8943 if (isFunctionTemplateSpecialization && isFriend &&
8944 (NewFD->getType()->isDependentType() || DC->isDependentContext() ||
8945 TemplateSpecializationType::anyDependentTemplateArguments(
8947 InstantiationDependent))) {
8948 assert(HasExplicitTemplateArgs &&
8949 "friend function specialization without template args");
8950 if (CheckDependentFunctionTemplateSpecialization(NewFD, TemplateArgs,
8952 NewFD->setInvalidDecl();
8953 } else if (isFunctionTemplateSpecialization) {
8954 if (CurContext->isDependentContext() && CurContext->isRecord()
8956 isDependentClassScopeExplicitSpecialization = true;
8957 } else if (!NewFD->isInvalidDecl() &&
8958 CheckFunctionTemplateSpecialization(
8959 NewFD, (HasExplicitTemplateArgs ? &TemplateArgs : nullptr),
8961 NewFD->setInvalidDecl();
8964 // A storage-class-specifier shall not be specified in an explicit
8965 // specialization (14.7.3)
8966 FunctionTemplateSpecializationInfo *Info =
8967 NewFD->getTemplateSpecializationInfo();
8968 if (Info && SC != SC_None) {
8969 if (SC != Info->getTemplate()->getTemplatedDecl()->getStorageClass())
8970 Diag(NewFD->getLocation(),
8971 diag::err_explicit_specialization_inconsistent_storage_class)
8973 << FixItHint::CreateRemoval(
8974 D.getDeclSpec().getStorageClassSpecLoc());
8977 Diag(NewFD->getLocation(),
8978 diag::ext_explicit_specialization_storage_class)
8979 << FixItHint::CreateRemoval(
8980 D.getDeclSpec().getStorageClassSpecLoc());
8982 } else if (isMemberSpecialization && isa<CXXMethodDecl>(NewFD)) {
8983 if (CheckMemberSpecialization(NewFD, Previous))
8984 NewFD->setInvalidDecl();
8987 // Perform semantic checking on the function declaration.
8988 if (!isDependentClassScopeExplicitSpecialization) {
8989 if (!NewFD->isInvalidDecl() && NewFD->isMain())
8990 CheckMain(NewFD, D.getDeclSpec());
8992 if (!NewFD->isInvalidDecl() && NewFD->isMSVCRTEntryPoint())
8993 CheckMSVCRTEntryPoint(NewFD);
8995 if (!NewFD->isInvalidDecl())
8996 D.setRedeclaration(CheckFunctionDeclaration(S, NewFD, Previous,
8997 isMemberSpecialization));
8998 else if (!Previous.empty())
8999 // Recover gracefully from an invalid redeclaration.
9000 D.setRedeclaration(true);
9003 assert((NewFD->isInvalidDecl() || !D.isRedeclaration() ||
9004 Previous.getResultKind() != LookupResult::FoundOverloaded) &&
9005 "previous declaration set still overloaded");
9007 NamedDecl *PrincipalDecl = (FunctionTemplate
9008 ? cast<NamedDecl>(FunctionTemplate)
9011 if (isFriend && NewFD->getPreviousDecl()) {
9012 AccessSpecifier Access = AS_public;
9013 if (!NewFD->isInvalidDecl())
9014 Access = NewFD->getPreviousDecl()->getAccess();
9016 NewFD->setAccess(Access);
9017 if (FunctionTemplate) FunctionTemplate->setAccess(Access);
9020 if (NewFD->isOverloadedOperator() && !DC->isRecord() &&
9021 PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary))
9022 PrincipalDecl->setNonMemberOperator();
9024 // If we have a function template, check the template parameter
9025 // list. This will check and merge default template arguments.
9026 if (FunctionTemplate) {
9027 FunctionTemplateDecl *PrevTemplate =
9028 FunctionTemplate->getPreviousDecl();
9029 CheckTemplateParameterList(FunctionTemplate->getTemplateParameters(),
9030 PrevTemplate ? PrevTemplate->getTemplateParameters()
9032 D.getDeclSpec().isFriendSpecified()
9033 ? (D.isFunctionDefinition()
9034 ? TPC_FriendFunctionTemplateDefinition
9035 : TPC_FriendFunctionTemplate)
9036 : (D.getCXXScopeSpec().isSet() &&
9037 DC && DC->isRecord() &&
9038 DC->isDependentContext())
9039 ? TPC_ClassTemplateMember
9040 : TPC_FunctionTemplate);
9043 if (NewFD->isInvalidDecl()) {
9044 // Ignore all the rest of this.
9045 } else if (!D.isRedeclaration()) {
9046 struct ActOnFDArgs ExtraArgs = { S, D, TemplateParamLists,
9048 // Fake up an access specifier if it's supposed to be a class member.
9049 if (isa<CXXRecordDecl>(NewFD->getDeclContext()))
9050 NewFD->setAccess(AS_public);
9052 // Qualified decls generally require a previous declaration.
9053 if (D.getCXXScopeSpec().isSet()) {
9054 // ...with the major exception of templated-scope or
9055 // dependent-scope friend declarations.
9057 // TODO: we currently also suppress this check in dependent
9058 // contexts because (1) the parameter depth will be off when
9059 // matching friend templates and (2) we might actually be
9060 // selecting a friend based on a dependent factor. But there
9061 // are situations where these conditions don't apply and we
9062 // can actually do this check immediately.
9064 (TemplateParamLists.size() ||
9065 D.getCXXScopeSpec().getScopeRep()->isDependent() ||
9066 CurContext->isDependentContext())) {
9069 // The user tried to provide an out-of-line definition for a
9070 // function that is a member of a class or namespace, but there
9071 // was no such member function declared (C++ [class.mfct]p2,
9072 // C++ [namespace.memdef]p2). For example:
9078 // void X::f() { } // ill-formed
9080 // Complain about this problem, and attempt to suggest close
9081 // matches (e.g., those that differ only in cv-qualifiers and
9082 // whether the parameter types are references).
9084 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
9085 *this, Previous, NewFD, ExtraArgs, false, nullptr)) {
9086 AddToScope = ExtraArgs.AddToScope;
9091 // Unqualified local friend declarations are required to resolve
9093 } else if (isFriend && cast<CXXRecordDecl>(CurContext)->isLocalClass()) {
9094 if (NamedDecl *Result = DiagnoseInvalidRedeclaration(
9095 *this, Previous, NewFD, ExtraArgs, true, S)) {
9096 AddToScope = ExtraArgs.AddToScope;
9100 } else if (!D.isFunctionDefinition() &&
9101 isa<CXXMethodDecl>(NewFD) && NewFD->isOutOfLine() &&
9102 !isFriend && !isFunctionTemplateSpecialization &&
9103 !isMemberSpecialization) {
9104 // An out-of-line member function declaration must also be a
9105 // definition (C++ [class.mfct]p2).
9106 // Note that this is not the case for explicit specializations of
9107 // function templates or member functions of class templates, per
9108 // C++ [temp.expl.spec]p2. We also allow these declarations as an
9109 // extension for compatibility with old SWIG code which likes to
9111 Diag(NewFD->getLocation(), diag::ext_out_of_line_declaration)
9112 << D.getCXXScopeSpec().getRange();
9116 ProcessPragmaWeak(S, NewFD);
9117 checkAttributesAfterMerging(*this, *NewFD);
9119 AddKnownFunctionAttributes(NewFD);
9121 if (NewFD->hasAttr<OverloadableAttr>() &&
9122 !NewFD->getType()->getAs<FunctionProtoType>()) {
9123 Diag(NewFD->getLocation(),
9124 diag::err_attribute_overloadable_no_prototype)
9127 // Turn this into a variadic function with no parameters.
9128 const FunctionType *FT = NewFD->getType()->getAs<FunctionType>();
9129 FunctionProtoType::ExtProtoInfo EPI(
9130 Context.getDefaultCallingConvention(true, false));
9131 EPI.Variadic = true;
9132 EPI.ExtInfo = FT->getExtInfo();
9134 QualType R = Context.getFunctionType(FT->getReturnType(), None, EPI);
9138 // If there's a #pragma GCC visibility in scope, and this isn't a class
9139 // member, set the visibility of this function.
9140 if (!DC->isRecord() && NewFD->isExternallyVisible())
9141 AddPushedVisibilityAttribute(NewFD);
9143 // If there's a #pragma clang arc_cf_code_audited in scope, consider
9144 // marking the function.
9145 AddCFAuditedAttribute(NewFD);
9147 // If this is a function definition, check if we have to apply optnone due to
9149 if(D.isFunctionDefinition())
9150 AddRangeBasedOptnone(NewFD);
9152 // If this is the first declaration of an extern C variable, update
9153 // the map of such variables.
9154 if (NewFD->isFirstDecl() && !NewFD->isInvalidDecl() &&
9155 isIncompleteDeclExternC(*this, NewFD))
9156 RegisterLocallyScopedExternCDecl(NewFD, S);
9158 // Set this FunctionDecl's range up to the right paren.
9159 NewFD->setRangeEnd(D.getSourceRange().getEnd());
9161 if (D.isRedeclaration() && !Previous.empty()) {
9162 NamedDecl *Prev = Previous.getRepresentativeDecl();
9163 checkDLLAttributeRedeclaration(*this, Prev, NewFD,
9164 isMemberSpecialization ||
9165 isFunctionTemplateSpecialization,
9166 D.isFunctionDefinition());
9169 if (getLangOpts().CUDA) {
9170 IdentifierInfo *II = NewFD->getIdentifier();
9172 II->isStr(getLangOpts().HIP ? "hipConfigureCall"
9173 : "cudaConfigureCall") &&
9174 !NewFD->isInvalidDecl() &&
9175 NewFD->getDeclContext()->getRedeclContext()->isTranslationUnit()) {
9176 if (!R->getAs<FunctionType>()->getReturnType()->isScalarType())
9177 Diag(NewFD->getLocation(), diag::err_config_scalar_return);
9178 Context.setcudaConfigureCallDecl(NewFD);
9181 // Variadic functions, other than a *declaration* of printf, are not allowed
9182 // in device-side CUDA code, unless someone passed
9183 // -fcuda-allow-variadic-functions.
9184 if (!getLangOpts().CUDAAllowVariadicFunctions && NewFD->isVariadic() &&
9185 (NewFD->hasAttr<CUDADeviceAttr>() ||
9186 NewFD->hasAttr<CUDAGlobalAttr>()) &&
9187 !(II && II->isStr("printf") && NewFD->isExternC() &&
9188 !D.isFunctionDefinition())) {
9189 Diag(NewFD->getLocation(), diag::err_variadic_device_fn);
9193 MarkUnusedFileScopedDecl(NewFD);
9195 if (getLangOpts().CPlusPlus) {
9196 if (FunctionTemplate) {
9197 if (NewFD->isInvalidDecl())
9198 FunctionTemplate->setInvalidDecl();
9199 return FunctionTemplate;
9202 if (isMemberSpecialization && !NewFD->isInvalidDecl())
9203 CompleteMemberSpecialization(NewFD, Previous);
9206 if (NewFD->hasAttr<OpenCLKernelAttr>()) {
9207 // OpenCL v1.2 s6.8 static is invalid for kernel functions.
9208 if ((getLangOpts().OpenCLVersion >= 120)
9209 && (SC == SC_Static)) {
9210 Diag(D.getIdentifierLoc(), diag::err_static_kernel);
9214 // OpenCL v1.2, s6.9 -- Kernels can only have return type void.
9215 if (!NewFD->getReturnType()->isVoidType()) {
9216 SourceRange RTRange = NewFD->getReturnTypeSourceRange();
9217 Diag(D.getIdentifierLoc(), diag::err_expected_kernel_void_return_type)
9218 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "void")
9223 llvm::SmallPtrSet<const Type *, 16> ValidTypes;
9224 for (auto Param : NewFD->parameters())
9225 checkIsValidOpenCLKernelParameter(*this, D, Param, ValidTypes);
9227 for (const ParmVarDecl *Param : NewFD->parameters()) {
9228 QualType PT = Param->getType();
9230 // OpenCL 2.0 pipe restrictions forbids pipe packet types to be non-value
9232 if (getLangOpts().OpenCLVersion >= 200) {
9233 if(const PipeType *PipeTy = PT->getAs<PipeType>()) {
9234 QualType ElemTy = PipeTy->getElementType();
9235 if (ElemTy->isReferenceType() || ElemTy->isPointerType()) {
9236 Diag(Param->getTypeSpecStartLoc(), diag::err_reference_pipe_type );
9243 // Here we have an function template explicit specialization at class scope.
9244 // The actual specialization will be postponed to template instatiation
9245 // time via the ClassScopeFunctionSpecializationDecl node.
9246 if (isDependentClassScopeExplicitSpecialization) {
9247 ClassScopeFunctionSpecializationDecl *NewSpec =
9248 ClassScopeFunctionSpecializationDecl::Create(
9249 Context, CurContext, NewFD->getLocation(),
9250 cast<CXXMethodDecl>(NewFD),
9251 HasExplicitTemplateArgs, TemplateArgs);
9252 CurContext->addDecl(NewSpec);
9256 // Diagnose availability attributes. Availability cannot be used on functions
9257 // that are run during load/unload.
9258 if (const auto *attr = NewFD->getAttr<AvailabilityAttr>()) {
9259 if (NewFD->hasAttr<ConstructorAttr>()) {
9260 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
9262 NewFD->dropAttr<AvailabilityAttr>();
9264 if (NewFD->hasAttr<DestructorAttr>()) {
9265 Diag(attr->getLocation(), diag::warn_availability_on_static_initializer)
9267 NewFD->dropAttr<AvailabilityAttr>();
9274 /// Return a CodeSegAttr from a containing class. The Microsoft docs say
9275 /// when __declspec(code_seg) "is applied to a class, all member functions of
9276 /// the class and nested classes -- this includes compiler-generated special
9277 /// member functions -- are put in the specified segment."
9278 /// The actual behavior is a little more complicated. The Microsoft compiler
9279 /// won't check outer classes if there is an active value from #pragma code_seg.
9280 /// The CodeSeg is always applied from the direct parent but only from outer
9281 /// classes when the #pragma code_seg stack is empty. See:
9282 /// https://reviews.llvm.org/D22931, the Microsoft feedback page is no longer
9283 /// available since MS has removed the page.
9284 static Attr *getImplicitCodeSegAttrFromClass(Sema &S, const FunctionDecl *FD) {
9285 const auto *Method = dyn_cast<CXXMethodDecl>(FD);
9288 const CXXRecordDecl *Parent = Method->getParent();
9289 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
9290 Attr *NewAttr = SAttr->clone(S.getASTContext());
9291 NewAttr->setImplicit(true);
9295 // The Microsoft compiler won't check outer classes for the CodeSeg
9296 // when the #pragma code_seg stack is active.
9297 if (S.CodeSegStack.CurrentValue)
9300 while ((Parent = dyn_cast<CXXRecordDecl>(Parent->getParent()))) {
9301 if (const auto *SAttr = Parent->getAttr<CodeSegAttr>()) {
9302 Attr *NewAttr = SAttr->clone(S.getASTContext());
9303 NewAttr->setImplicit(true);
9310 /// Returns an implicit CodeSegAttr if a __declspec(code_seg) is found on a
9311 /// containing class. Otherwise it will return implicit SectionAttr if the
9312 /// function is a definition and there is an active value on CodeSegStack
9313 /// (from the current #pragma code-seg value).
9315 /// \param FD Function being declared.
9316 /// \param IsDefinition Whether it is a definition or just a declarartion.
9317 /// \returns A CodeSegAttr or SectionAttr to apply to the function or
9318 /// nullptr if no attribute should be added.
9319 Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
9320 bool IsDefinition) {
9321 if (Attr *A = getImplicitCodeSegAttrFromClass(*this, FD))
9323 if (!FD->hasAttr<SectionAttr>() && IsDefinition &&
9324 CodeSegStack.CurrentValue) {
9325 return SectionAttr::CreateImplicit(getASTContext(),
9326 SectionAttr::Declspec_allocate,
9327 CodeSegStack.CurrentValue->getString(),
9328 CodeSegStack.CurrentPragmaLocation);
9333 /// Determines if we can perform a correct type check for \p D as a
9334 /// redeclaration of \p PrevDecl. If not, we can generally still perform a
9335 /// best-effort check.
9337 /// \param NewD The new declaration.
9338 /// \param OldD The old declaration.
9339 /// \param NewT The portion of the type of the new declaration to check.
9340 /// \param OldT The portion of the type of the old declaration to check.
9341 bool Sema::canFullyTypeCheckRedeclaration(ValueDecl *NewD, ValueDecl *OldD,
9342 QualType NewT, QualType OldT) {
9343 if (!NewD->getLexicalDeclContext()->isDependentContext())
9346 // For dependently-typed local extern declarations and friends, we can't
9347 // perform a correct type check in general until instantiation:
9350 // template<typename T> void g() { T f(); }
9352 // (valid if g() is only instantiated with T = int).
9353 if (NewT->isDependentType() &&
9354 (NewD->isLocalExternDecl() || NewD->getFriendObjectKind()))
9357 // Similarly, if the previous declaration was a dependent local extern
9358 // declaration, we don't really know its type yet.
9359 if (OldT->isDependentType() && OldD->isLocalExternDecl())
9365 /// Checks if the new declaration declared in dependent context must be
9366 /// put in the same redeclaration chain as the specified declaration.
9368 /// \param D Declaration that is checked.
9369 /// \param PrevDecl Previous declaration found with proper lookup method for the
9370 /// same declaration name.
9371 /// \returns True if D must be added to the redeclaration chain which PrevDecl
9374 bool Sema::shouldLinkDependentDeclWithPrevious(Decl *D, Decl *PrevDecl) {
9375 if (!D->getLexicalDeclContext()->isDependentContext())
9378 // Don't chain dependent friend function definitions until instantiation, to
9379 // permit cases like
9382 // template<typename T> class C1 { friend void func() {} };
9383 // template<typename T> class C2 { friend void func() {} };
9385 // ... which is valid if only one of C1 and C2 is ever instantiated.
9387 // FIXME: This need only apply to function definitions. For now, we proxy
9388 // this by checking for a file-scope function. We do not want this to apply
9389 // to friend declarations nominating member functions, because that gets in
9390 // the way of access checks.
9391 if (D->getFriendObjectKind() && D->getDeclContext()->isFileContext())
9394 auto *VD = dyn_cast<ValueDecl>(D);
9395 auto *PrevVD = dyn_cast<ValueDecl>(PrevDecl);
9396 return !VD || !PrevVD ||
9397 canFullyTypeCheckRedeclaration(VD, PrevVD, VD->getType(),
9401 namespace MultiVersioning {
9402 enum Type { None, Target, CPUSpecific, CPUDispatch};
9403 } // MultiVersionType
9405 static MultiVersioning::Type
9406 getMultiVersionType(const FunctionDecl *FD) {
9407 if (FD->hasAttr<TargetAttr>())
9408 return MultiVersioning::Target;
9409 if (FD->hasAttr<CPUDispatchAttr>())
9410 return MultiVersioning::CPUDispatch;
9411 if (FD->hasAttr<CPUSpecificAttr>())
9412 return MultiVersioning::CPUSpecific;
9413 return MultiVersioning::None;
9415 /// Check the target attribute of the function for MultiVersion
9418 /// Returns true if there was an error, false otherwise.
9419 static bool CheckMultiVersionValue(Sema &S, const FunctionDecl *FD) {
9420 const auto *TA = FD->getAttr<TargetAttr>();
9421 assert(TA && "MultiVersion Candidate requires a target attribute");
9422 TargetAttr::ParsedTargetAttr ParseInfo = TA->parse();
9423 const TargetInfo &TargetInfo = S.Context.getTargetInfo();
9424 enum ErrType { Feature = 0, Architecture = 1 };
9426 if (!ParseInfo.Architecture.empty() &&
9427 !TargetInfo.validateCpuIs(ParseInfo.Architecture)) {
9428 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9429 << Architecture << ParseInfo.Architecture;
9433 for (const auto &Feat : ParseInfo.Features) {
9434 auto BareFeat = StringRef{Feat}.substr(1);
9435 if (Feat[0] == '-') {
9436 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9437 << Feature << ("no-" + BareFeat).str();
9441 if (!TargetInfo.validateCpuSupports(BareFeat) ||
9442 !TargetInfo.isValidFeatureName(BareFeat)) {
9443 S.Diag(FD->getLocation(), diag::err_bad_multiversion_option)
9444 << Feature << BareFeat;
9451 static bool CheckMultiVersionAdditionalRules(Sema &S, const FunctionDecl *OldFD,
9452 const FunctionDecl *NewFD,
9454 MultiVersioning::Type MVType) {
9455 enum DoesntSupport {
9474 bool IsCPUSpecificCPUDispatchMVType =
9475 MVType == MultiVersioning::CPUDispatch ||
9476 MVType == MultiVersioning::CPUSpecific;
9478 if (OldFD && !OldFD->getType()->getAs<FunctionProtoType>()) {
9479 S.Diag(OldFD->getLocation(), diag::err_multiversion_noproto);
9480 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9484 if (!NewFD->getType()->getAs<FunctionProtoType>())
9485 return S.Diag(NewFD->getLocation(), diag::err_multiversion_noproto);
9487 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
9488 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
9490 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9494 // For now, disallow all other attributes. These should be opt-in, but
9495 // an analysis of all of them is a future FIXME.
9496 if (CausesMV && OldFD &&
9497 std::distance(OldFD->attr_begin(), OldFD->attr_end()) != 1) {
9498 S.Diag(OldFD->getLocation(), diag::err_multiversion_no_other_attrs)
9499 << IsCPUSpecificCPUDispatchMVType;
9500 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9504 if (std::distance(NewFD->attr_begin(), NewFD->attr_end()) != 1)
9505 return S.Diag(NewFD->getLocation(), diag::err_multiversion_no_other_attrs)
9506 << IsCPUSpecificCPUDispatchMVType;
9508 if (NewFD->getTemplatedKind() == FunctionDecl::TK_FunctionTemplate)
9509 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9510 << IsCPUSpecificCPUDispatchMVType << FuncTemplates;
9512 if (const auto *NewCXXFD = dyn_cast<CXXMethodDecl>(NewFD)) {
9513 if (NewCXXFD->isVirtual())
9514 return S.Diag(NewCXXFD->getLocation(),
9515 diag::err_multiversion_doesnt_support)
9516 << IsCPUSpecificCPUDispatchMVType << VirtFuncs;
9518 if (const auto *NewCXXCtor = dyn_cast<CXXConstructorDecl>(NewFD))
9519 return S.Diag(NewCXXCtor->getLocation(),
9520 diag::err_multiversion_doesnt_support)
9521 << IsCPUSpecificCPUDispatchMVType << Constructors;
9523 if (const auto *NewCXXDtor = dyn_cast<CXXDestructorDecl>(NewFD))
9524 return S.Diag(NewCXXDtor->getLocation(),
9525 diag::err_multiversion_doesnt_support)
9526 << IsCPUSpecificCPUDispatchMVType << Destructors;
9529 if (NewFD->isDeleted())
9530 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9531 << IsCPUSpecificCPUDispatchMVType << DeletedFuncs;
9533 if (NewFD->isDefaulted())
9534 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9535 << IsCPUSpecificCPUDispatchMVType << DefaultedFuncs;
9537 if (NewFD->isConstexpr() && (MVType == MultiVersioning::CPUDispatch ||
9538 MVType == MultiVersioning::CPUSpecific))
9539 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9540 << IsCPUSpecificCPUDispatchMVType << ConstexprFuncs;
9542 QualType NewQType = S.getASTContext().getCanonicalType(NewFD->getType());
9543 const auto *NewType = cast<FunctionType>(NewQType);
9544 QualType NewReturnType = NewType->getReturnType();
9546 if (NewReturnType->isUndeducedType())
9547 return S.Diag(NewFD->getLocation(), diag::err_multiversion_doesnt_support)
9548 << IsCPUSpecificCPUDispatchMVType << DeducedReturn;
9550 // Only allow transition to MultiVersion if it hasn't been used.
9551 if (OldFD && CausesMV && OldFD->isUsed(false))
9552 return S.Diag(NewFD->getLocation(), diag::err_multiversion_after_used);
9554 // Ensure the return type is identical.
9556 QualType OldQType = S.getASTContext().getCanonicalType(OldFD->getType());
9557 const auto *OldType = cast<FunctionType>(OldQType);
9558 FunctionType::ExtInfo OldTypeInfo = OldType->getExtInfo();
9559 FunctionType::ExtInfo NewTypeInfo = NewType->getExtInfo();
9561 if (OldTypeInfo.getCC() != NewTypeInfo.getCC())
9562 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9565 QualType OldReturnType = OldType->getReturnType();
9567 if (OldReturnType != NewReturnType)
9568 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9571 if (OldFD->isConstexpr() != NewFD->isConstexpr())
9572 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9575 if (OldFD->isInlineSpecified() != NewFD->isInlineSpecified())
9576 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9579 if (OldFD->getStorageClass() != NewFD->getStorageClass())
9580 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9583 if (OldFD->isExternC() != NewFD->isExternC())
9584 return S.Diag(NewFD->getLocation(), diag::err_multiversion_diff)
9587 if (S.CheckEquivalentExceptionSpec(
9588 OldFD->getType()->getAs<FunctionProtoType>(), OldFD->getLocation(),
9589 NewFD->getType()->getAs<FunctionProtoType>(), NewFD->getLocation()))
9595 /// Check the validity of a multiversion function declaration that is the
9596 /// first of its kind. Also sets the multiversion'ness' of the function itself.
9598 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9600 /// Returns true if there was an error, false otherwise.
9601 static bool CheckMultiVersionFirstFunction(Sema &S, FunctionDecl *FD,
9602 MultiVersioning::Type MVType,
9603 const TargetAttr *TA,
9604 const CPUDispatchAttr *CPUDisp,
9605 const CPUSpecificAttr *CPUSpec) {
9606 assert(MVType != MultiVersioning::None &&
9607 "Function lacks multiversion attribute");
9609 // Target only causes MV if it is default, otherwise this is a normal
9611 if (MVType == MultiVersioning::Target && !TA->isDefaultVersion())
9614 if (MVType == MultiVersioning::Target && CheckMultiVersionValue(S, FD)) {
9615 FD->setInvalidDecl();
9619 if (CheckMultiVersionAdditionalRules(S, nullptr, FD, true, MVType)) {
9620 FD->setInvalidDecl();
9624 FD->setIsMultiVersion();
9628 static bool CheckTargetCausesMultiVersioning(
9629 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD, const TargetAttr *NewTA,
9630 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,
9631 LookupResult &Previous) {
9632 const auto *OldTA = OldFD->getAttr<TargetAttr>();
9633 TargetAttr::ParsedTargetAttr NewParsed = NewTA->parse();
9634 // Sort order doesn't matter, it just needs to be consistent.
9635 llvm::sort(NewParsed.Features.begin(), NewParsed.Features.end());
9637 // If the old decl is NOT MultiVersioned yet, and we don't cause that
9638 // to change, this is a simple redeclaration.
9639 if (!OldTA || OldTA->getFeaturesStr() == NewTA->getFeaturesStr())
9642 // Otherwise, this decl causes MultiVersioning.
9643 if (!S.getASTContext().getTargetInfo().supportsMultiVersioning()) {
9644 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_supported);
9645 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9646 NewFD->setInvalidDecl();
9650 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, true,
9651 MultiVersioning::Target)) {
9652 NewFD->setInvalidDecl();
9656 if (CheckMultiVersionValue(S, NewFD)) {
9657 NewFD->setInvalidDecl();
9661 if (CheckMultiVersionValue(S, OldFD)) {
9662 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9663 NewFD->setInvalidDecl();
9667 TargetAttr::ParsedTargetAttr OldParsed =
9668 OldTA->parse(std::less<std::string>());
9670 if (OldParsed == NewParsed) {
9671 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
9672 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9673 NewFD->setInvalidDecl();
9677 for (const auto *FD : OldFD->redecls()) {
9678 const auto *CurTA = FD->getAttr<TargetAttr>();
9679 if (!CurTA || CurTA->isInherited()) {
9680 S.Diag(FD->getLocation(), diag::err_multiversion_required_in_redecl)
9682 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9683 NewFD->setInvalidDecl();
9688 OldFD->setIsMultiVersion();
9689 NewFD->setIsMultiVersion();
9690 Redeclaration = false;
9691 MergeTypeWithPrevious = false;
9697 /// Check the validity of a new function declaration being added to an existing
9698 /// multiversioned declaration collection.
9699 static bool CheckMultiVersionAdditionalDecl(
9700 Sema &S, FunctionDecl *OldFD, FunctionDecl *NewFD,
9701 MultiVersioning::Type NewMVType, const TargetAttr *NewTA,
9702 const CPUDispatchAttr *NewCPUDisp, const CPUSpecificAttr *NewCPUSpec,
9703 bool &Redeclaration, NamedDecl *&OldDecl, bool &MergeTypeWithPrevious,
9704 LookupResult &Previous) {
9706 MultiVersioning::Type OldMVType = getMultiVersionType(OldFD);
9707 // Disallow mixing of multiversioning types.
9708 if ((OldMVType == MultiVersioning::Target &&
9709 NewMVType != MultiVersioning::Target) ||
9710 (NewMVType == MultiVersioning::Target &&
9711 OldMVType != MultiVersioning::Target)) {
9712 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed);
9713 S.Diag(OldFD->getLocation(), diag::note_previous_declaration);
9714 NewFD->setInvalidDecl();
9718 TargetAttr::ParsedTargetAttr NewParsed;
9720 NewParsed = NewTA->parse();
9721 llvm::sort(NewParsed.Features.begin(), NewParsed.Features.end());
9724 bool UseMemberUsingDeclRules =
9725 S.CurContext->isRecord() && !NewFD->getFriendObjectKind();
9727 // Next, check ALL non-overloads to see if this is a redeclaration of a
9728 // previous member of the MultiVersion set.
9729 for (NamedDecl *ND : Previous) {
9730 FunctionDecl *CurFD = ND->getAsFunction();
9733 if (S.IsOverload(NewFD, CurFD, UseMemberUsingDeclRules))
9736 if (NewMVType == MultiVersioning::Target) {
9737 const auto *CurTA = CurFD->getAttr<TargetAttr>();
9738 if (CurTA->getFeaturesStr() == NewTA->getFeaturesStr()) {
9739 NewFD->setIsMultiVersion();
9740 Redeclaration = true;
9745 TargetAttr::ParsedTargetAttr CurParsed =
9746 CurTA->parse(std::less<std::string>());
9747 if (CurParsed == NewParsed) {
9748 S.Diag(NewFD->getLocation(), diag::err_multiversion_duplicate);
9749 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9750 NewFD->setInvalidDecl();
9754 const auto *CurCPUSpec = CurFD->getAttr<CPUSpecificAttr>();
9755 const auto *CurCPUDisp = CurFD->getAttr<CPUDispatchAttr>();
9756 // Handle CPUDispatch/CPUSpecific versions.
9757 // Only 1 CPUDispatch function is allowed, this will make it go through
9758 // the redeclaration errors.
9759 if (NewMVType == MultiVersioning::CPUDispatch &&
9760 CurFD->hasAttr<CPUDispatchAttr>()) {
9761 if (CurCPUDisp->cpus_size() == NewCPUDisp->cpus_size() &&
9763 CurCPUDisp->cpus_begin(), CurCPUDisp->cpus_end(),
9764 NewCPUDisp->cpus_begin(),
9765 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
9766 return Cur->getName() == New->getName();
9768 NewFD->setIsMultiVersion();
9769 Redeclaration = true;
9774 // If the declarations don't match, this is an error condition.
9775 S.Diag(NewFD->getLocation(), diag::err_cpu_dispatch_mismatch);
9776 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9777 NewFD->setInvalidDecl();
9780 if (NewMVType == MultiVersioning::CPUSpecific && CurCPUSpec) {
9782 if (CurCPUSpec->cpus_size() == NewCPUSpec->cpus_size() &&
9784 CurCPUSpec->cpus_begin(), CurCPUSpec->cpus_end(),
9785 NewCPUSpec->cpus_begin(),
9786 [](const IdentifierInfo *Cur, const IdentifierInfo *New) {
9787 return Cur->getName() == New->getName();
9789 NewFD->setIsMultiVersion();
9790 Redeclaration = true;
9795 // Only 1 version of CPUSpecific is allowed for each CPU.
9796 for (const IdentifierInfo *CurII : CurCPUSpec->cpus()) {
9797 for (const IdentifierInfo *NewII : NewCPUSpec->cpus()) {
9798 if (CurII == NewII) {
9799 S.Diag(NewFD->getLocation(), diag::err_cpu_specific_multiple_defs)
9801 S.Diag(CurFD->getLocation(), diag::note_previous_declaration);
9802 NewFD->setInvalidDecl();
9808 // If the two decls aren't the same MVType, there is no possible error
9813 // Else, this is simply a non-redecl case. Checking the 'value' is only
9814 // necessary in the Target case, since The CPUSpecific/Dispatch cases are
9815 // handled in the attribute adding step.
9816 if (NewMVType == MultiVersioning::Target &&
9817 CheckMultiVersionValue(S, NewFD)) {
9818 NewFD->setInvalidDecl();
9822 if (CheckMultiVersionAdditionalRules(S, OldFD, NewFD, false, NewMVType)) {
9823 NewFD->setInvalidDecl();
9827 NewFD->setIsMultiVersion();
9828 Redeclaration = false;
9829 MergeTypeWithPrevious = false;
9836 /// Check the validity of a mulitversion function declaration.
9837 /// Also sets the multiversion'ness' of the function itself.
9839 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9841 /// Returns true if there was an error, false otherwise.
9842 static bool CheckMultiVersionFunction(Sema &S, FunctionDecl *NewFD,
9843 bool &Redeclaration, NamedDecl *&OldDecl,
9844 bool &MergeTypeWithPrevious,
9845 LookupResult &Previous) {
9846 const auto *NewTA = NewFD->getAttr<TargetAttr>();
9847 const auto *NewCPUDisp = NewFD->getAttr<CPUDispatchAttr>();
9848 const auto *NewCPUSpec = NewFD->getAttr<CPUSpecificAttr>();
9850 // Mixing Multiversioning types is prohibited.
9851 if ((NewTA && NewCPUDisp) || (NewTA && NewCPUSpec) ||
9852 (NewCPUDisp && NewCPUSpec)) {
9853 S.Diag(NewFD->getLocation(), diag::err_multiversion_types_mixed);
9854 NewFD->setInvalidDecl();
9858 MultiVersioning::Type MVType = getMultiVersionType(NewFD);
9860 // Main isn't allowed to become a multiversion function, however it IS
9861 // permitted to have 'main' be marked with the 'target' optimization hint.
9862 if (NewFD->isMain()) {
9863 if ((MVType == MultiVersioning::Target && NewTA->isDefaultVersion()) ||
9864 MVType == MultiVersioning::CPUDispatch ||
9865 MVType == MultiVersioning::CPUSpecific) {
9866 S.Diag(NewFD->getLocation(), diag::err_multiversion_not_allowed_on_main);
9867 NewFD->setInvalidDecl();
9873 if (!OldDecl || !OldDecl->getAsFunction() ||
9874 OldDecl->getDeclContext()->getRedeclContext() !=
9875 NewFD->getDeclContext()->getRedeclContext()) {
9876 // If there's no previous declaration, AND this isn't attempting to cause
9877 // multiversioning, this isn't an error condition.
9878 if (MVType == MultiVersioning::None)
9880 return CheckMultiVersionFirstFunction(S, NewFD, MVType, NewTA, NewCPUDisp,
9884 FunctionDecl *OldFD = OldDecl->getAsFunction();
9886 if (!OldFD->isMultiVersion() && MVType == MultiVersioning::None)
9889 if (OldFD->isMultiVersion() && MVType == MultiVersioning::None) {
9890 S.Diag(NewFD->getLocation(), diag::err_multiversion_required_in_redecl)
9891 << (getMultiVersionType(OldFD) != MultiVersioning::Target);
9892 NewFD->setInvalidDecl();
9896 // Handle the target potentially causes multiversioning case.
9897 if (!OldFD->isMultiVersion() && MVType == MultiVersioning::Target)
9898 return CheckTargetCausesMultiVersioning(S, OldFD, NewFD, NewTA,
9899 Redeclaration, OldDecl,
9900 MergeTypeWithPrevious, Previous);
9901 // Previous declarations lack CPUDispatch/CPUSpecific.
9902 if (!OldFD->isMultiVersion()) {
9903 S.Diag(OldFD->getLocation(), diag::err_multiversion_required_in_redecl)
9905 S.Diag(NewFD->getLocation(), diag::note_multiversioning_caused_here);
9906 NewFD->setInvalidDecl();
9910 // At this point, we have a multiversion function decl (in OldFD) AND an
9911 // appropriate attribute in the current function decl. Resolve that these are
9912 // still compatible with previous declarations.
9913 return CheckMultiVersionAdditionalDecl(
9914 S, OldFD, NewFD, MVType, NewTA, NewCPUDisp, NewCPUSpec, Redeclaration,
9915 OldDecl, MergeTypeWithPrevious, Previous);
9918 /// Perform semantic checking of a new function declaration.
9920 /// Performs semantic analysis of the new function declaration
9921 /// NewFD. This routine performs all semantic checking that does not
9922 /// require the actual declarator involved in the declaration, and is
9923 /// used both for the declaration of functions as they are parsed
9924 /// (called via ActOnDeclarator) and for the declaration of functions
9925 /// that have been instantiated via C++ template instantiation (called
9926 /// via InstantiateDecl).
9928 /// \param IsMemberSpecialization whether this new function declaration is
9929 /// a member specialization (that replaces any definition provided by the
9930 /// previous declaration).
9932 /// This sets NewFD->isInvalidDecl() to true if there was an error.
9934 /// \returns true if the function declaration is a redeclaration.
9935 bool Sema::CheckFunctionDeclaration(Scope *S, FunctionDecl *NewFD,
9936 LookupResult &Previous,
9937 bool IsMemberSpecialization) {
9938 assert(!NewFD->getReturnType()->isVariablyModifiedType() &&
9939 "Variably modified return types are not handled here");
9941 // Determine whether the type of this function should be merged with
9942 // a previous visible declaration. This never happens for functions in C++,
9943 // and always happens in C if the previous declaration was visible.
9944 bool MergeTypeWithPrevious = !getLangOpts().CPlusPlus &&
9945 !Previous.isShadowed();
9947 bool Redeclaration = false;
9948 NamedDecl *OldDecl = nullptr;
9949 bool MayNeedOverloadableChecks = false;
9951 // Merge or overload the declaration with an existing declaration of
9952 // the same name, if appropriate.
9953 if (!Previous.empty()) {
9954 // Determine whether NewFD is an overload of PrevDecl or
9955 // a declaration that requires merging. If it's an overload,
9956 // there's no more work to do here; we'll just add the new
9957 // function to the scope.
9958 if (!AllowOverloadingOfFunction(Previous, Context, NewFD)) {
9959 NamedDecl *Candidate = Previous.getRepresentativeDecl();
9960 if (shouldLinkPossiblyHiddenDecl(Candidate, NewFD)) {
9961 Redeclaration = true;
9962 OldDecl = Candidate;
9965 MayNeedOverloadableChecks = true;
9966 switch (CheckOverload(S, NewFD, Previous, OldDecl,
9967 /*NewIsUsingDecl*/ false)) {
9969 Redeclaration = true;
9972 case Ovl_NonFunction:
9973 Redeclaration = true;
9977 Redeclaration = false;
9983 // Check for a previous extern "C" declaration with this name.
9984 if (!Redeclaration &&
9985 checkForConflictWithNonVisibleExternC(*this, NewFD, Previous)) {
9986 if (!Previous.empty()) {
9987 // This is an extern "C" declaration with the same name as a previous
9988 // declaration, and thus redeclares that entity...
9989 Redeclaration = true;
9990 OldDecl = Previous.getFoundDecl();
9991 MergeTypeWithPrevious = false;
9993 // ... except in the presence of __attribute__((overloadable)).
9994 if (OldDecl->hasAttr<OverloadableAttr>() ||
9995 NewFD->hasAttr<OverloadableAttr>()) {
9996 if (IsOverload(NewFD, cast<FunctionDecl>(OldDecl), false)) {
9997 MayNeedOverloadableChecks = true;
9998 Redeclaration = false;
10005 if (CheckMultiVersionFunction(*this, NewFD, Redeclaration, OldDecl,
10006 MergeTypeWithPrevious, Previous))
10007 return Redeclaration;
10009 // C++11 [dcl.constexpr]p8:
10010 // A constexpr specifier for a non-static member function that is not
10011 // a constructor declares that member function to be const.
10013 // This needs to be delayed until we know whether this is an out-of-line
10014 // definition of a static member function.
10016 // This rule is not present in C++1y, so we produce a backwards
10017 // compatibility warning whenever it happens in C++11.
10018 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(NewFD);
10019 if (!getLangOpts().CPlusPlus14 && MD && MD->isConstexpr() &&
10020 !MD->isStatic() && !isa<CXXConstructorDecl>(MD) &&
10021 (MD->getTypeQualifiers() & Qualifiers::Const) == 0) {
10022 CXXMethodDecl *OldMD = nullptr;
10024 OldMD = dyn_cast_or_null<CXXMethodDecl>(OldDecl->getAsFunction());
10025 if (!OldMD || !OldMD->isStatic()) {
10026 const FunctionProtoType *FPT =
10027 MD->getType()->castAs<FunctionProtoType>();
10028 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
10029 EPI.TypeQuals |= Qualifiers::Const;
10030 MD->setType(Context.getFunctionType(FPT->getReturnType(),
10031 FPT->getParamTypes(), EPI));
10033 // Warn that we did this, if we're not performing template instantiation.
10034 // In that case, we'll have warned already when the template was defined.
10035 if (!inTemplateInstantiation()) {
10036 SourceLocation AddConstLoc;
10037 if (FunctionTypeLoc FTL = MD->getTypeSourceInfo()->getTypeLoc()
10038 .IgnoreParens().getAs<FunctionTypeLoc>())
10039 AddConstLoc = getLocForEndOfToken(FTL.getRParenLoc());
10041 Diag(MD->getLocation(), diag::warn_cxx14_compat_constexpr_not_const)
10042 << FixItHint::CreateInsertion(AddConstLoc, " const");
10047 if (Redeclaration) {
10048 // NewFD and OldDecl represent declarations that need to be
10050 if (MergeFunctionDecl(NewFD, OldDecl, S, MergeTypeWithPrevious)) {
10051 NewFD->setInvalidDecl();
10052 return Redeclaration;
10056 Previous.addDecl(OldDecl);
10058 if (FunctionTemplateDecl *OldTemplateDecl =
10059 dyn_cast<FunctionTemplateDecl>(OldDecl)) {
10060 auto *OldFD = OldTemplateDecl->getTemplatedDecl();
10061 NewFD->setPreviousDeclaration(OldFD);
10062 adjustDeclContextForDeclaratorDecl(NewFD, OldFD);
10063 FunctionTemplateDecl *NewTemplateDecl
10064 = NewFD->getDescribedFunctionTemplate();
10065 assert(NewTemplateDecl && "Template/non-template mismatch");
10066 if (NewFD->isCXXClassMember()) {
10067 NewFD->setAccess(OldTemplateDecl->getAccess());
10068 NewTemplateDecl->setAccess(OldTemplateDecl->getAccess());
10071 // If this is an explicit specialization of a member that is a function
10072 // template, mark it as a member specialization.
10073 if (IsMemberSpecialization &&
10074 NewTemplateDecl->getInstantiatedFromMemberTemplate()) {
10075 NewTemplateDecl->setMemberSpecialization();
10076 assert(OldTemplateDecl->isMemberSpecialization());
10077 // Explicit specializations of a member template do not inherit deleted
10078 // status from the parent member template that they are specializing.
10079 if (OldFD->isDeleted()) {
10080 // FIXME: This assert will not hold in the presence of modules.
10081 assert(OldFD->getCanonicalDecl() == OldFD);
10082 // FIXME: We need an update record for this AST mutation.
10083 OldFD->setDeletedAsWritten(false);
10088 if (shouldLinkDependentDeclWithPrevious(NewFD, OldDecl)) {
10089 auto *OldFD = cast<FunctionDecl>(OldDecl);
10090 // This needs to happen first so that 'inline' propagates.
10091 NewFD->setPreviousDeclaration(OldFD);
10092 adjustDeclContextForDeclaratorDecl(NewFD, OldFD);
10093 if (NewFD->isCXXClassMember())
10094 NewFD->setAccess(OldFD->getAccess());
10097 } else if (!getLangOpts().CPlusPlus && MayNeedOverloadableChecks &&
10098 !NewFD->getAttr<OverloadableAttr>()) {
10099 assert((Previous.empty() ||
10100 llvm::any_of(Previous,
10101 [](const NamedDecl *ND) {
10102 return ND->hasAttr<OverloadableAttr>();
10104 "Non-redecls shouldn't happen without overloadable present");
10106 auto OtherUnmarkedIter = llvm::find_if(Previous, [](const NamedDecl *ND) {
10107 const auto *FD = dyn_cast<FunctionDecl>(ND);
10108 return FD && !FD->hasAttr<OverloadableAttr>();
10111 if (OtherUnmarkedIter != Previous.end()) {
10112 Diag(NewFD->getLocation(),
10113 diag::err_attribute_overloadable_multiple_unmarked_overloads);
10114 Diag((*OtherUnmarkedIter)->getLocation(),
10115 diag::note_attribute_overloadable_prev_overload)
10118 NewFD->addAttr(OverloadableAttr::CreateImplicit(Context));
10122 // Semantic checking for this function declaration (in isolation).
10124 if (getLangOpts().CPlusPlus) {
10125 // C++-specific checks.
10126 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(NewFD)) {
10127 CheckConstructor(Constructor);
10128 } else if (CXXDestructorDecl *Destructor =
10129 dyn_cast<CXXDestructorDecl>(NewFD)) {
10130 CXXRecordDecl *Record = Destructor->getParent();
10131 QualType ClassType = Context.getTypeDeclType(Record);
10133 // FIXME: Shouldn't we be able to perform this check even when the class
10134 // type is dependent? Both gcc and edg can handle that.
10135 if (!ClassType->isDependentType()) {
10136 DeclarationName Name
10137 = Context.DeclarationNames.getCXXDestructorName(
10138 Context.getCanonicalType(ClassType));
10139 if (NewFD->getDeclName() != Name) {
10140 Diag(NewFD->getLocation(), diag::err_destructor_name);
10141 NewFD->setInvalidDecl();
10142 return Redeclaration;
10145 } else if (CXXConversionDecl *Conversion
10146 = dyn_cast<CXXConversionDecl>(NewFD)) {
10147 ActOnConversionDeclarator(Conversion);
10148 } else if (auto *Guide = dyn_cast<CXXDeductionGuideDecl>(NewFD)) {
10149 if (auto *TD = Guide->getDescribedFunctionTemplate())
10150 CheckDeductionGuideTemplate(TD);
10152 // A deduction guide is not on the list of entities that can be
10153 // explicitly specialized.
10154 if (Guide->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
10155 Diag(Guide->getLocStart(), diag::err_deduction_guide_specialized)
10156 << /*explicit specialization*/ 1;
10159 // Find any virtual functions that this function overrides.
10160 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(NewFD)) {
10161 if (!Method->isFunctionTemplateSpecialization() &&
10162 !Method->getDescribedFunctionTemplate() &&
10163 Method->isCanonicalDecl()) {
10164 if (AddOverriddenMethods(Method->getParent(), Method)) {
10165 // If the function was marked as "static", we have a problem.
10166 if (NewFD->getStorageClass() == SC_Static) {
10167 ReportOverrides(*this, diag::err_static_overrides_virtual, Method);
10172 if (Method->isStatic())
10173 checkThisInStaticMemberFunctionType(Method);
10176 // Extra checking for C++ overloaded operators (C++ [over.oper]).
10177 if (NewFD->isOverloadedOperator() &&
10178 CheckOverloadedOperatorDeclaration(NewFD)) {
10179 NewFD->setInvalidDecl();
10180 return Redeclaration;
10183 // Extra checking for C++0x literal operators (C++0x [over.literal]).
10184 if (NewFD->getLiteralIdentifier() &&
10185 CheckLiteralOperatorDeclaration(NewFD)) {
10186 NewFD->setInvalidDecl();
10187 return Redeclaration;
10190 // In C++, check default arguments now that we have merged decls. Unless
10191 // the lexical context is the class, because in this case this is done
10192 // during delayed parsing anyway.
10193 if (!CurContext->isRecord())
10194 CheckCXXDefaultArguments(NewFD);
10196 // If this function declares a builtin function, check the type of this
10197 // declaration against the expected type for the builtin.
10198 if (unsigned BuiltinID = NewFD->getBuiltinID()) {
10199 ASTContext::GetBuiltinTypeError Error;
10200 LookupPredefedObjCSuperType(*this, S, NewFD->getIdentifier());
10201 QualType T = Context.GetBuiltinType(BuiltinID, Error);
10202 // If the type of the builtin differs only in its exception
10203 // specification, that's OK.
10204 // FIXME: If the types do differ in this way, it would be better to
10205 // retain the 'noexcept' form of the type.
10207 !Context.hasSameFunctionTypeIgnoringExceptionSpec(T,
10209 // The type of this function differs from the type of the builtin,
10210 // so forget about the builtin entirely.
10211 Context.BuiltinInfo.forgetBuiltin(BuiltinID, Context.Idents);
10214 // If this function is declared as being extern "C", then check to see if
10215 // the function returns a UDT (class, struct, or union type) that is not C
10216 // compatible, and if it does, warn the user.
10217 // But, issue any diagnostic on the first declaration only.
10218 if (Previous.empty() && NewFD->isExternC()) {
10219 QualType R = NewFD->getReturnType();
10220 if (R->isIncompleteType() && !R->isVoidType())
10221 Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete)
10223 else if (!R.isPODType(Context) && !R->isVoidType() &&
10224 !R->isObjCObjectPointerType())
10225 Diag(NewFD->getLocation(), diag::warn_return_value_udt) << NewFD << R;
10228 // C++1z [dcl.fct]p6:
10229 // [...] whether the function has a non-throwing exception-specification
10230 // [is] part of the function type
10232 // This results in an ABI break between C++14 and C++17 for functions whose
10233 // declared type includes an exception-specification in a parameter or
10234 // return type. (Exception specifications on the function itself are OK in
10235 // most cases, and exception specifications are not permitted in most other
10236 // contexts where they could make it into a mangling.)
10237 if (!getLangOpts().CPlusPlus17 && !NewFD->getPrimaryTemplate()) {
10238 auto HasNoexcept = [&](QualType T) -> bool {
10239 // Strip off declarator chunks that could be between us and a function
10240 // type. We don't need to look far, exception specifications are very
10241 // restricted prior to C++17.
10242 if (auto *RT = T->getAs<ReferenceType>())
10243 T = RT->getPointeeType();
10244 else if (T->isAnyPointerType())
10245 T = T->getPointeeType();
10246 else if (auto *MPT = T->getAs<MemberPointerType>())
10247 T = MPT->getPointeeType();
10248 if (auto *FPT = T->getAs<FunctionProtoType>())
10249 if (FPT->isNothrow())
10254 auto *FPT = NewFD->getType()->castAs<FunctionProtoType>();
10255 bool AnyNoexcept = HasNoexcept(FPT->getReturnType());
10256 for (QualType T : FPT->param_types())
10257 AnyNoexcept |= HasNoexcept(T);
10259 Diag(NewFD->getLocation(),
10260 diag::warn_cxx17_compat_exception_spec_in_signature)
10264 if (!Redeclaration && LangOpts.CUDA)
10265 checkCUDATargetOverload(NewFD, Previous);
10267 return Redeclaration;
10270 void Sema::CheckMain(FunctionDecl* FD, const DeclSpec& DS) {
10271 // C++11 [basic.start.main]p3:
10272 // A program that [...] declares main to be inline, static or
10273 // constexpr is ill-formed.
10274 // C11 6.7.4p4: In a hosted environment, no function specifier(s) shall
10275 // appear in a declaration of main.
10276 // static main is not an error under C99, but we should warn about it.
10277 // We accept _Noreturn main as an extension.
10278 if (FD->getStorageClass() == SC_Static)
10279 Diag(DS.getStorageClassSpecLoc(), getLangOpts().CPlusPlus
10280 ? diag::err_static_main : diag::warn_static_main)
10281 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
10282 if (FD->isInlineSpecified())
10283 Diag(DS.getInlineSpecLoc(), diag::err_inline_main)
10284 << FixItHint::CreateRemoval(DS.getInlineSpecLoc());
10285 if (DS.isNoreturnSpecified()) {
10286 SourceLocation NoreturnLoc = DS.getNoreturnSpecLoc();
10287 SourceRange NoreturnRange(NoreturnLoc, getLocForEndOfToken(NoreturnLoc));
10288 Diag(NoreturnLoc, diag::ext_noreturn_main);
10289 Diag(NoreturnLoc, diag::note_main_remove_noreturn)
10290 << FixItHint::CreateRemoval(NoreturnRange);
10292 if (FD->isConstexpr()) {
10293 Diag(DS.getConstexprSpecLoc(), diag::err_constexpr_main)
10294 << FixItHint::CreateRemoval(DS.getConstexprSpecLoc());
10295 FD->setConstexpr(false);
10298 if (getLangOpts().OpenCL) {
10299 Diag(FD->getLocation(), diag::err_opencl_no_main)
10300 << FD->hasAttr<OpenCLKernelAttr>();
10301 FD->setInvalidDecl();
10305 QualType T = FD->getType();
10306 assert(T->isFunctionType() && "function decl is not of function type");
10307 const FunctionType* FT = T->castAs<FunctionType>();
10309 // Set default calling convention for main()
10310 if (FT->getCallConv() != CC_C) {
10311 FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(CC_C));
10312 FD->setType(QualType(FT, 0));
10313 T = Context.getCanonicalType(FD->getType());
10316 if (getLangOpts().GNUMode && !getLangOpts().CPlusPlus) {
10317 // In C with GNU extensions we allow main() to have non-integer return
10318 // type, but we should warn about the extension, and we disable the
10319 // implicit-return-zero rule.
10321 // GCC in C mode accepts qualified 'int'.
10322 if (Context.hasSameUnqualifiedType(FT->getReturnType(), Context.IntTy))
10323 FD->setHasImplicitReturnZero(true);
10325 Diag(FD->getTypeSpecStartLoc(), diag::ext_main_returns_nonint);
10326 SourceRange RTRange = FD->getReturnTypeSourceRange();
10327 if (RTRange.isValid())
10328 Diag(RTRange.getBegin(), diag::note_main_change_return_type)
10329 << FixItHint::CreateReplacement(RTRange, "int");
10332 // In C and C++, main magically returns 0 if you fall off the end;
10333 // set the flag which tells us that.
10334 // This is C++ [basic.start.main]p5 and C99 5.1.2.2.3.
10336 // All the standards say that main() should return 'int'.
10337 if (Context.hasSameType(FT->getReturnType(), Context.IntTy))
10338 FD->setHasImplicitReturnZero(true);
10340 // Otherwise, this is just a flat-out error.
10341 SourceRange RTRange = FD->getReturnTypeSourceRange();
10342 Diag(FD->getTypeSpecStartLoc(), diag::err_main_returns_nonint)
10343 << (RTRange.isValid() ? FixItHint::CreateReplacement(RTRange, "int")
10345 FD->setInvalidDecl(true);
10349 // Treat protoless main() as nullary.
10350 if (isa<FunctionNoProtoType>(FT)) return;
10352 const FunctionProtoType* FTP = cast<const FunctionProtoType>(FT);
10353 unsigned nparams = FTP->getNumParams();
10354 assert(FD->getNumParams() == nparams);
10356 bool HasExtraParameters = (nparams > 3);
10358 if (FTP->isVariadic()) {
10359 Diag(FD->getLocation(), diag::ext_variadic_main);
10360 // FIXME: if we had information about the location of the ellipsis, we
10361 // could add a FixIt hint to remove it as a parameter.
10364 // Darwin passes an undocumented fourth argument of type char**. If
10365 // other platforms start sprouting these, the logic below will start
10367 if (nparams == 4 && Context.getTargetInfo().getTriple().isOSDarwin())
10368 HasExtraParameters = false;
10370 if (HasExtraParameters) {
10371 Diag(FD->getLocation(), diag::err_main_surplus_args) << nparams;
10372 FD->setInvalidDecl(true);
10376 // FIXME: a lot of the following diagnostics would be improved
10377 // if we had some location information about types.
10380 Context.getPointerType(Context.getPointerType(Context.CharTy));
10381 QualType Expected[] = { Context.IntTy, CharPP, CharPP, CharPP };
10383 for (unsigned i = 0; i < nparams; ++i) {
10384 QualType AT = FTP->getParamType(i);
10386 bool mismatch = true;
10388 if (Context.hasSameUnqualifiedType(AT, Expected[i]))
10390 else if (Expected[i] == CharPP) {
10391 // As an extension, the following forms are okay:
10393 // char const * const *
10396 QualifierCollector qs;
10397 const PointerType* PT;
10398 if ((PT = qs.strip(AT)->getAs<PointerType>()) &&
10399 (PT = qs.strip(PT->getPointeeType())->getAs<PointerType>()) &&
10400 Context.hasSameType(QualType(qs.strip(PT->getPointeeType()), 0),
10403 mismatch = !qs.empty();
10408 Diag(FD->getLocation(), diag::err_main_arg_wrong) << i << Expected[i];
10409 // TODO: suggest replacing given type with expected type
10410 FD->setInvalidDecl(true);
10414 if (nparams == 1 && !FD->isInvalidDecl()) {
10415 Diag(FD->getLocation(), diag::warn_main_one_arg);
10418 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
10419 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
10420 FD->setInvalidDecl();
10424 void Sema::CheckMSVCRTEntryPoint(FunctionDecl *FD) {
10425 QualType T = FD->getType();
10426 assert(T->isFunctionType() && "function decl is not of function type");
10427 const FunctionType *FT = T->castAs<FunctionType>();
10429 // Set an implicit return of 'zero' if the function can return some integral,
10430 // enumeration, pointer or nullptr type.
10431 if (FT->getReturnType()->isIntegralOrEnumerationType() ||
10432 FT->getReturnType()->isAnyPointerType() ||
10433 FT->getReturnType()->isNullPtrType())
10434 // DllMain is exempt because a return value of zero means it failed.
10435 if (FD->getName() != "DllMain")
10436 FD->setHasImplicitReturnZero(true);
10438 if (!FD->isInvalidDecl() && FD->getDescribedFunctionTemplate()) {
10439 Diag(FD->getLocation(), diag::err_mainlike_template_decl) << FD;
10440 FD->setInvalidDecl();
10444 bool Sema::CheckForConstantInitializer(Expr *Init, QualType DclT) {
10445 // FIXME: Need strict checking. In C89, we need to check for
10446 // any assignment, increment, decrement, function-calls, or
10447 // commas outside of a sizeof. In C99, it's the same list,
10448 // except that the aforementioned are allowed in unevaluated
10449 // expressions. Everything else falls under the
10450 // "may accept other forms of constant expressions" exception.
10451 // (We never end up here for C++, so the constant expression
10452 // rules there don't matter.)
10453 const Expr *Culprit;
10454 if (Init->isConstantInitializer(Context, false, &Culprit))
10456 Diag(Culprit->getExprLoc(), diag::err_init_element_not_constant)
10457 << Culprit->getSourceRange();
10462 // Visits an initialization expression to see if OrigDecl is evaluated in
10463 // its own initialization and throws a warning if it does.
10464 class SelfReferenceChecker
10465 : public EvaluatedExprVisitor<SelfReferenceChecker> {
10470 bool isReferenceType;
10473 llvm::SmallVector<unsigned, 4> InitFieldIndex;
10476 typedef EvaluatedExprVisitor<SelfReferenceChecker> Inherited;
10478 SelfReferenceChecker(Sema &S, Decl *OrigDecl) : Inherited(S.Context),
10479 S(S), OrigDecl(OrigDecl) {
10481 isRecordType = false;
10482 isReferenceType = false;
10483 isInitList = false;
10484 if (ValueDecl *VD = dyn_cast<ValueDecl>(OrigDecl)) {
10485 isPODType = VD->getType().isPODType(S.Context);
10486 isRecordType = VD->getType()->isRecordType();
10487 isReferenceType = VD->getType()->isReferenceType();
10491 // For most expressions, just call the visitor. For initializer lists,
10492 // track the index of the field being initialized since fields are
10493 // initialized in order allowing use of previously initialized fields.
10494 void CheckExpr(Expr *E) {
10495 InitListExpr *InitList = dyn_cast<InitListExpr>(E);
10501 // Track and increment the index here.
10503 InitFieldIndex.push_back(0);
10504 for (auto Child : InitList->children()) {
10505 CheckExpr(cast<Expr>(Child));
10506 ++InitFieldIndex.back();
10508 InitFieldIndex.pop_back();
10511 // Returns true if MemberExpr is checked and no further checking is needed.
10512 // Returns false if additional checking is required.
10513 bool CheckInitListMemberExpr(MemberExpr *E, bool CheckReference) {
10514 llvm::SmallVector<FieldDecl*, 4> Fields;
10516 bool ReferenceField = false;
10518 // Get the field memebers used.
10519 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10520 FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl());
10523 Fields.push_back(FD);
10524 if (FD->getType()->isReferenceType())
10525 ReferenceField = true;
10526 Base = ME->getBase()->IgnoreParenImpCasts();
10529 // Keep checking only if the base Decl is the same.
10530 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base);
10531 if (!DRE || DRE->getDecl() != OrigDecl)
10534 // A reference field can be bound to an unininitialized field.
10535 if (CheckReference && !ReferenceField)
10538 // Convert FieldDecls to their index number.
10539 llvm::SmallVector<unsigned, 4> UsedFieldIndex;
10540 for (const FieldDecl *I : llvm::reverse(Fields))
10541 UsedFieldIndex.push_back(I->getFieldIndex());
10543 // See if a warning is needed by checking the first difference in index
10544 // numbers. If field being used has index less than the field being
10545 // initialized, then the use is safe.
10546 for (auto UsedIter = UsedFieldIndex.begin(),
10547 UsedEnd = UsedFieldIndex.end(),
10548 OrigIter = InitFieldIndex.begin(),
10549 OrigEnd = InitFieldIndex.end();
10550 UsedIter != UsedEnd && OrigIter != OrigEnd; ++UsedIter, ++OrigIter) {
10551 if (*UsedIter < *OrigIter)
10553 if (*UsedIter > *OrigIter)
10557 // TODO: Add a different warning which will print the field names.
10558 HandleDeclRefExpr(DRE);
10562 // For most expressions, the cast is directly above the DeclRefExpr.
10563 // For conditional operators, the cast can be outside the conditional
10564 // operator if both expressions are DeclRefExpr's.
10565 void HandleValue(Expr *E) {
10566 E = E->IgnoreParens();
10567 if (DeclRefExpr* DRE = dyn_cast<DeclRefExpr>(E)) {
10568 HandleDeclRefExpr(DRE);
10572 if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) {
10573 Visit(CO->getCond());
10574 HandleValue(CO->getTrueExpr());
10575 HandleValue(CO->getFalseExpr());
10579 if (BinaryConditionalOperator *BCO =
10580 dyn_cast<BinaryConditionalOperator>(E)) {
10581 Visit(BCO->getCond());
10582 HandleValue(BCO->getFalseExpr());
10586 if (OpaqueValueExpr *OVE = dyn_cast<OpaqueValueExpr>(E)) {
10587 HandleValue(OVE->getSourceExpr());
10591 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(E)) {
10592 if (BO->getOpcode() == BO_Comma) {
10593 Visit(BO->getLHS());
10594 HandleValue(BO->getRHS());
10599 if (isa<MemberExpr>(E)) {
10601 if (CheckInitListMemberExpr(cast<MemberExpr>(E),
10602 false /*CheckReference*/))
10606 Expr *Base = E->IgnoreParenImpCasts();
10607 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10608 // Check for static member variables and don't warn on them.
10609 if (!isa<FieldDecl>(ME->getMemberDecl()))
10611 Base = ME->getBase()->IgnoreParenImpCasts();
10613 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base))
10614 HandleDeclRefExpr(DRE);
10621 // Reference types not handled in HandleValue are handled here since all
10622 // uses of references are bad, not just r-value uses.
10623 void VisitDeclRefExpr(DeclRefExpr *E) {
10624 if (isReferenceType)
10625 HandleDeclRefExpr(E);
10628 void VisitImplicitCastExpr(ImplicitCastExpr *E) {
10629 if (E->getCastKind() == CK_LValueToRValue) {
10630 HandleValue(E->getSubExpr());
10634 Inherited::VisitImplicitCastExpr(E);
10637 void VisitMemberExpr(MemberExpr *E) {
10639 if (CheckInitListMemberExpr(E, true /*CheckReference*/))
10643 // Don't warn on arrays since they can be treated as pointers.
10644 if (E->getType()->canDecayToPointerType()) return;
10646 // Warn when a non-static method call is followed by non-static member
10647 // field accesses, which is followed by a DeclRefExpr.
10648 CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(E->getMemberDecl());
10649 bool Warn = (MD && !MD->isStatic());
10650 Expr *Base = E->getBase()->IgnoreParenImpCasts();
10651 while (MemberExpr *ME = dyn_cast<MemberExpr>(Base)) {
10652 if (!isa<FieldDecl>(ME->getMemberDecl()))
10654 Base = ME->getBase()->IgnoreParenImpCasts();
10657 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) {
10659 HandleDeclRefExpr(DRE);
10663 // The base of a MemberExpr is not a MemberExpr or a DeclRefExpr.
10664 // Visit that expression.
10668 void VisitCXXOperatorCallExpr(CXXOperatorCallExpr *E) {
10669 Expr *Callee = E->getCallee();
10671 if (isa<UnresolvedLookupExpr>(Callee))
10672 return Inherited::VisitCXXOperatorCallExpr(E);
10675 for (auto Arg: E->arguments())
10676 HandleValue(Arg->IgnoreParenImpCasts());
10679 void VisitUnaryOperator(UnaryOperator *E) {
10680 // For POD record types, addresses of its own members are well-defined.
10681 if (E->getOpcode() == UO_AddrOf && isRecordType &&
10682 isa<MemberExpr>(E->getSubExpr()->IgnoreParens())) {
10684 HandleValue(E->getSubExpr());
10688 if (E->isIncrementDecrementOp()) {
10689 HandleValue(E->getSubExpr());
10693 Inherited::VisitUnaryOperator(E);
10696 void VisitObjCMessageExpr(ObjCMessageExpr *E) {}
10698 void VisitCXXConstructExpr(CXXConstructExpr *E) {
10699 if (E->getConstructor()->isCopyConstructor()) {
10700 Expr *ArgExpr = E->getArg(0);
10701 if (InitListExpr *ILE = dyn_cast<InitListExpr>(ArgExpr))
10702 if (ILE->getNumInits() == 1)
10703 ArgExpr = ILE->getInit(0);
10704 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
10705 if (ICE->getCastKind() == CK_NoOp)
10706 ArgExpr = ICE->getSubExpr();
10707 HandleValue(ArgExpr);
10710 Inherited::VisitCXXConstructExpr(E);
10713 void VisitCallExpr(CallExpr *E) {
10714 // Treat std::move as a use.
10715 if (E->isCallToStdMove()) {
10716 HandleValue(E->getArg(0));
10720 Inherited::VisitCallExpr(E);
10723 void VisitBinaryOperator(BinaryOperator *E) {
10724 if (E->isCompoundAssignmentOp()) {
10725 HandleValue(E->getLHS());
10726 Visit(E->getRHS());
10730 Inherited::VisitBinaryOperator(E);
10733 // A custom visitor for BinaryConditionalOperator is needed because the
10734 // regular visitor would check the condition and true expression separately
10735 // but both point to the same place giving duplicate diagnostics.
10736 void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) {
10737 Visit(E->getCond());
10738 Visit(E->getFalseExpr());
10741 void HandleDeclRefExpr(DeclRefExpr *DRE) {
10742 Decl* ReferenceDecl = DRE->getDecl();
10743 if (OrigDecl != ReferenceDecl) return;
10745 if (isReferenceType) {
10746 diag = diag::warn_uninit_self_reference_in_reference_init;
10747 } else if (cast<VarDecl>(OrigDecl)->isStaticLocal()) {
10748 diag = diag::warn_static_self_reference_in_init;
10749 } else if (isa<TranslationUnitDecl>(OrigDecl->getDeclContext()) ||
10750 isa<NamespaceDecl>(OrigDecl->getDeclContext()) ||
10751 DRE->getDecl()->getType()->isRecordType()) {
10752 diag = diag::warn_uninit_self_reference_in_init;
10754 // Local variables will be handled by the CFG analysis.
10758 S.DiagRuntimeBehavior(DRE->getLocStart(), DRE,
10761 << OrigDecl->getLocation()
10762 << DRE->getSourceRange());
10766 /// CheckSelfReference - Warns if OrigDecl is used in expression E.
10767 static void CheckSelfReference(Sema &S, Decl* OrigDecl, Expr *E,
10769 // Parameters arguments are occassionially constructed with itself,
10770 // for instance, in recursive functions. Skip them.
10771 if (isa<ParmVarDecl>(OrigDecl))
10774 E = E->IgnoreParens();
10776 // Skip checking T a = a where T is not a record or reference type.
10777 // Doing so is a way to silence uninitialized warnings.
10778 if (!DirectInit && !cast<VarDecl>(OrigDecl)->getType()->isRecordType())
10779 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
10780 if (ICE->getCastKind() == CK_LValueToRValue)
10781 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr()))
10782 if (DRE->getDecl() == OrigDecl)
10785 SelfReferenceChecker(S, OrigDecl).CheckExpr(E);
10787 } // end anonymous namespace
10790 // Simple wrapper to add the name of a variable or (if no variable is
10791 // available) a DeclarationName into a diagnostic.
10792 struct VarDeclOrName {
10794 DeclarationName Name;
10796 friend const Sema::SemaDiagnosticBuilder &
10797 operator<<(const Sema::SemaDiagnosticBuilder &Diag, VarDeclOrName VN) {
10798 return VN.VDecl ? Diag << VN.VDecl : Diag << VN.Name;
10801 } // end anonymous namespace
10803 QualType Sema::deduceVarTypeFromInitializer(VarDecl *VDecl,
10804 DeclarationName Name, QualType Type,
10805 TypeSourceInfo *TSI,
10806 SourceRange Range, bool DirectInit,
10808 bool IsInitCapture = !VDecl;
10809 assert((!VDecl || !VDecl->isInitCapture()) &&
10810 "init captures are expected to be deduced prior to initialization");
10812 VarDeclOrName VN{VDecl, Name};
10814 DeducedType *Deduced = Type->getContainedDeducedType();
10815 assert(Deduced && "deduceVarTypeFromInitializer for non-deduced type");
10817 // C++11 [dcl.spec.auto]p3
10819 assert(VDecl && "no init for init capture deduction?");
10821 // Except for class argument deduction, and then for an initializing
10822 // declaration only, i.e. no static at class scope or extern.
10823 if (!isa<DeducedTemplateSpecializationType>(Deduced) ||
10824 VDecl->hasExternalStorage() ||
10825 VDecl->isStaticDataMember()) {
10826 Diag(VDecl->getLocation(), diag::err_auto_var_requires_init)
10827 << VDecl->getDeclName() << Type;
10832 ArrayRef<Expr*> DeduceInits;
10834 DeduceInits = Init;
10837 if (auto *PL = dyn_cast_or_null<ParenListExpr>(Init))
10838 DeduceInits = PL->exprs();
10841 if (isa<DeducedTemplateSpecializationType>(Deduced)) {
10842 assert(VDecl && "non-auto type for init capture deduction?");
10843 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
10844 InitializationKind Kind = InitializationKind::CreateForInit(
10845 VDecl->getLocation(), DirectInit, Init);
10846 // FIXME: Initialization should not be taking a mutable list of inits.
10847 SmallVector<Expr*, 8> InitsCopy(DeduceInits.begin(), DeduceInits.end());
10848 return DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind,
10853 if (auto *IL = dyn_cast<InitListExpr>(Init))
10854 DeduceInits = IL->inits();
10857 // Deduction only works if we have exactly one source expression.
10858 if (DeduceInits.empty()) {
10859 // It isn't possible to write this directly, but it is possible to
10860 // end up in this situation with "auto x(some_pack...);"
10861 Diag(Init->getLocStart(), IsInitCapture
10862 ? diag::err_init_capture_no_expression
10863 : diag::err_auto_var_init_no_expression)
10864 << VN << Type << Range;
10868 if (DeduceInits.size() > 1) {
10869 Diag(DeduceInits[1]->getLocStart(),
10870 IsInitCapture ? diag::err_init_capture_multiple_expressions
10871 : diag::err_auto_var_init_multiple_expressions)
10872 << VN << Type << Range;
10876 Expr *DeduceInit = DeduceInits[0];
10877 if (DirectInit && isa<InitListExpr>(DeduceInit)) {
10878 Diag(Init->getLocStart(), IsInitCapture
10879 ? diag::err_init_capture_paren_braces
10880 : diag::err_auto_var_init_paren_braces)
10881 << isa<InitListExpr>(Init) << VN << Type << Range;
10885 // Expressions default to 'id' when we're in a debugger.
10886 bool DefaultedAnyToId = false;
10887 if (getLangOpts().DebuggerCastResultToId &&
10888 Init->getType() == Context.UnknownAnyTy && !IsInitCapture) {
10889 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
10890 if (Result.isInvalid()) {
10893 Init = Result.get();
10894 DefaultedAnyToId = true;
10897 // C++ [dcl.decomp]p1:
10898 // If the assignment-expression [...] has array type A and no ref-qualifier
10899 // is present, e has type cv A
10900 if (VDecl && isa<DecompositionDecl>(VDecl) &&
10901 Context.hasSameUnqualifiedType(Type, Context.getAutoDeductType()) &&
10902 DeduceInit->getType()->isConstantArrayType())
10903 return Context.getQualifiedType(DeduceInit->getType(),
10904 Type.getQualifiers());
10906 QualType DeducedType;
10907 if (DeduceAutoType(TSI, DeduceInit, DeducedType) == DAR_Failed) {
10908 if (!IsInitCapture)
10909 DiagnoseAutoDeductionFailure(VDecl, DeduceInit);
10910 else if (isa<InitListExpr>(Init))
10911 Diag(Range.getBegin(),
10912 diag::err_init_capture_deduction_failure_from_init_list)
10914 << (DeduceInit->getType().isNull() ? TSI->getType()
10915 : DeduceInit->getType())
10916 << DeduceInit->getSourceRange();
10918 Diag(Range.getBegin(), diag::err_init_capture_deduction_failure)
10919 << VN << TSI->getType()
10920 << (DeduceInit->getType().isNull() ? TSI->getType()
10921 : DeduceInit->getType())
10922 << DeduceInit->getSourceRange();
10925 // Warn if we deduced 'id'. 'auto' usually implies type-safety, but using
10926 // 'id' instead of a specific object type prevents most of our usual
10928 // We only want to warn outside of template instantiations, though:
10929 // inside a template, the 'id' could have come from a parameter.
10930 if (!inTemplateInstantiation() && !DefaultedAnyToId && !IsInitCapture &&
10931 !DeducedType.isNull() && DeducedType->isObjCIdType()) {
10932 SourceLocation Loc = TSI->getTypeLoc().getBeginLoc();
10933 Diag(Loc, diag::warn_auto_var_is_id) << VN << Range;
10936 return DeducedType;
10939 bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
10941 QualType DeducedType = deduceVarTypeFromInitializer(
10942 VDecl, VDecl->getDeclName(), VDecl->getType(), VDecl->getTypeSourceInfo(),
10943 VDecl->getSourceRange(), DirectInit, Init);
10944 if (DeducedType.isNull()) {
10945 VDecl->setInvalidDecl();
10949 VDecl->setType(DeducedType);
10950 assert(VDecl->isLinkageValid());
10952 // In ARC, infer lifetime.
10953 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(VDecl))
10954 VDecl->setInvalidDecl();
10956 // If this is a redeclaration, check that the type we just deduced matches
10957 // the previously declared type.
10958 if (VarDecl *Old = VDecl->getPreviousDecl()) {
10959 // We never need to merge the type, because we cannot form an incomplete
10960 // array of auto, nor deduce such a type.
10961 MergeVarDeclTypes(VDecl, Old, /*MergeTypeWithPrevious*/ false);
10964 // Check the deduced type is valid for a variable declaration.
10965 CheckVariableDeclarationType(VDecl);
10966 return VDecl->isInvalidDecl();
10969 /// AddInitializerToDecl - Adds the initializer Init to the
10970 /// declaration dcl. If DirectInit is true, this is C++ direct
10971 /// initialization rather than copy initialization.
10972 void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init, bool DirectInit) {
10973 // If there is no declaration, there was an error parsing it. Just ignore
10974 // the initializer.
10975 if (!RealDecl || RealDecl->isInvalidDecl()) {
10976 CorrectDelayedTyposInExpr(Init, dyn_cast_or_null<VarDecl>(RealDecl));
10980 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(RealDecl)) {
10981 // Pure-specifiers are handled in ActOnPureSpecifier.
10982 Diag(Method->getLocation(), diag::err_member_function_initialization)
10983 << Method->getDeclName() << Init->getSourceRange();
10984 Method->setInvalidDecl();
10988 VarDecl *VDecl = dyn_cast<VarDecl>(RealDecl);
10990 assert(!isa<FieldDecl>(RealDecl) && "field init shouldn't get here");
10991 Diag(RealDecl->getLocation(), diag::err_illegal_initializer);
10992 RealDecl->setInvalidDecl();
10996 // C++11 [decl.spec.auto]p6. Deduce the type which 'auto' stands in for.
10997 if (VDecl->getType()->isUndeducedType()) {
10998 // Attempt typo correction early so that the type of the init expression can
10999 // be deduced based on the chosen correction if the original init contains a
11001 ExprResult Res = CorrectDelayedTyposInExpr(Init, VDecl);
11002 if (!Res.isUsable()) {
11003 RealDecl->setInvalidDecl();
11008 if (DeduceVariableDeclarationType(VDecl, DirectInit, Init))
11012 // dllimport cannot be used on variable definitions.
11013 if (VDecl->hasAttr<DLLImportAttr>() && !VDecl->isStaticDataMember()) {
11014 Diag(VDecl->getLocation(), diag::err_attribute_dllimport_data_definition);
11015 VDecl->setInvalidDecl();
11019 if (VDecl->isLocalVarDecl() && VDecl->hasExternalStorage()) {
11020 // C99 6.7.8p5. C++ has no such restriction, but that is a defect.
11021 Diag(VDecl->getLocation(), diag::err_block_extern_cant_init);
11022 VDecl->setInvalidDecl();
11026 if (!VDecl->getType()->isDependentType()) {
11027 // A definition must end up with a complete type, which means it must be
11028 // complete with the restriction that an array type might be completed by
11029 // the initializer; note that later code assumes this restriction.
11030 QualType BaseDeclType = VDecl->getType();
11031 if (const ArrayType *Array = Context.getAsIncompleteArrayType(BaseDeclType))
11032 BaseDeclType = Array->getElementType();
11033 if (RequireCompleteType(VDecl->getLocation(), BaseDeclType,
11034 diag::err_typecheck_decl_incomplete_type)) {
11035 RealDecl->setInvalidDecl();
11039 // The variable can not have an abstract class type.
11040 if (RequireNonAbstractType(VDecl->getLocation(), VDecl->getType(),
11041 diag::err_abstract_type_in_decl,
11042 AbstractVariableType))
11043 VDecl->setInvalidDecl();
11046 // If adding the initializer will turn this declaration into a definition,
11047 // and we already have a definition for this variable, diagnose or otherwise
11048 // handle the situation.
11050 if ((Def = VDecl->getDefinition()) && Def != VDecl &&
11051 (!VDecl->isStaticDataMember() || VDecl->isOutOfLine()) &&
11052 !VDecl->isThisDeclarationADemotedDefinition() &&
11053 checkVarDeclRedefinition(Def, VDecl))
11056 if (getLangOpts().CPlusPlus) {
11057 // C++ [class.static.data]p4
11058 // If a static data member is of const integral or const
11059 // enumeration type, its declaration in the class definition can
11060 // specify a constant-initializer which shall be an integral
11061 // constant expression (5.19). In that case, the member can appear
11062 // in integral constant expressions. The member shall still be
11063 // defined in a namespace scope if it is used in the program and the
11064 // namespace scope definition shall not contain an initializer.
11066 // We already performed a redefinition check above, but for static
11067 // data members we also need to check whether there was an in-class
11068 // declaration with an initializer.
11069 if (VDecl->isStaticDataMember() && VDecl->getCanonicalDecl()->hasInit()) {
11070 Diag(Init->getExprLoc(), diag::err_static_data_member_reinitialization)
11071 << VDecl->getDeclName();
11072 Diag(VDecl->getCanonicalDecl()->getInit()->getExprLoc(),
11073 diag::note_previous_initializer)
11078 if (VDecl->hasLocalStorage())
11079 setFunctionHasBranchProtectedScope();
11081 if (DiagnoseUnexpandedParameterPack(Init, UPPC_Initializer)) {
11082 VDecl->setInvalidDecl();
11087 // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside
11088 // a kernel function cannot be initialized."
11089 if (VDecl->getType().getAddressSpace() == LangAS::opencl_local) {
11090 Diag(VDecl->getLocation(), diag::err_local_cant_init);
11091 VDecl->setInvalidDecl();
11095 // Get the decls type and save a reference for later, since
11096 // CheckInitializerTypes may change it.
11097 QualType DclT = VDecl->getType(), SavT = DclT;
11099 // Expressions default to 'id' when we're in a debugger
11100 // and we are assigning it to a variable of Objective-C pointer type.
11101 if (getLangOpts().DebuggerCastResultToId && DclT->isObjCObjectPointerType() &&
11102 Init->getType() == Context.UnknownAnyTy) {
11103 ExprResult Result = forceUnknownAnyToType(Init, Context.getObjCIdType());
11104 if (Result.isInvalid()) {
11105 VDecl->setInvalidDecl();
11108 Init = Result.get();
11111 // Perform the initialization.
11112 ParenListExpr *CXXDirectInit = dyn_cast<ParenListExpr>(Init);
11113 if (!VDecl->isInvalidDecl()) {
11114 InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
11115 InitializationKind Kind = InitializationKind::CreateForInit(
11116 VDecl->getLocation(), DirectInit, Init);
11118 MultiExprArg Args = Init;
11120 Args = MultiExprArg(CXXDirectInit->getExprs(),
11121 CXXDirectInit->getNumExprs());
11123 // Try to correct any TypoExprs in the initialization arguments.
11124 for (size_t Idx = 0; Idx < Args.size(); ++Idx) {
11125 ExprResult Res = CorrectDelayedTyposInExpr(
11126 Args[Idx], VDecl, [this, Entity, Kind](Expr *E) {
11127 InitializationSequence Init(*this, Entity, Kind, MultiExprArg(E));
11128 return Init.Failed() ? ExprError() : E;
11130 if (Res.isInvalid()) {
11131 VDecl->setInvalidDecl();
11132 } else if (Res.get() != Args[Idx]) {
11133 Args[Idx] = Res.get();
11136 if (VDecl->isInvalidDecl())
11139 InitializationSequence InitSeq(*this, Entity, Kind, Args,
11140 /*TopLevelOfInitList=*/false,
11141 /*TreatUnavailableAsInvalid=*/false);
11142 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, Args, &DclT);
11143 if (Result.isInvalid()) {
11144 VDecl->setInvalidDecl();
11148 Init = Result.getAs<Expr>();
11151 // Check for self-references within variable initializers.
11152 // Variables declared within a function/method body (except for references)
11153 // are handled by a dataflow analysis.
11154 if (!VDecl->hasLocalStorage() || VDecl->getType()->isRecordType() ||
11155 VDecl->getType()->isReferenceType()) {
11156 CheckSelfReference(*this, RealDecl, Init, DirectInit);
11159 // If the type changed, it means we had an incomplete type that was
11160 // completed by the initializer. For example:
11161 // int ary[] = { 1, 3, 5 };
11162 // "ary" transitions from an IncompleteArrayType to a ConstantArrayType.
11163 if (!VDecl->isInvalidDecl() && (DclT != SavT))
11164 VDecl->setType(DclT);
11166 if (!VDecl->isInvalidDecl()) {
11167 checkUnsafeAssigns(VDecl->getLocation(), VDecl->getType(), Init);
11169 if (VDecl->hasAttr<BlocksAttr>())
11170 checkRetainCycles(VDecl, Init);
11172 // It is safe to assign a weak reference into a strong variable.
11173 // Although this code can still have problems:
11174 // id x = self.weakProp;
11175 // id y = self.weakProp;
11176 // we do not warn to warn spuriously when 'x' and 'y' are on separate
11177 // paths through the function. This should be revisited if
11178 // -Wrepeated-use-of-weak is made flow-sensitive.
11179 if (FunctionScopeInfo *FSI = getCurFunction())
11180 if ((VDecl->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
11181 VDecl->getType().isNonWeakInMRRWithObjCWeak(Context)) &&
11182 !Diags.isIgnored(diag::warn_arc_repeated_use_of_weak,
11183 Init->getLocStart()))
11184 FSI->markSafeWeakUse(Init);
11187 // The initialization is usually a full-expression.
11189 // FIXME: If this is a braced initialization of an aggregate, it is not
11190 // an expression, and each individual field initializer is a separate
11191 // full-expression. For instance, in:
11193 // struct Temp { ~Temp(); };
11194 // struct S { S(Temp); };
11195 // struct T { S a, b; } t = { Temp(), Temp() }
11197 // we should destroy the first Temp before constructing the second.
11198 ExprResult Result = ActOnFinishFullExpr(Init, VDecl->getLocation(),
11200 VDecl->isConstexpr());
11201 if (Result.isInvalid()) {
11202 VDecl->setInvalidDecl();
11205 Init = Result.get();
11207 // Attach the initializer to the decl.
11208 VDecl->setInit(Init);
11210 if (VDecl->isLocalVarDecl()) {
11211 // Don't check the initializer if the declaration is malformed.
11212 if (VDecl->isInvalidDecl()) {
11215 // OpenCL v1.2 s6.5.3: __constant locals must be constant-initialized.
11216 // This is true even in OpenCL C++.
11217 } else if (VDecl->getType().getAddressSpace() == LangAS::opencl_constant) {
11218 CheckForConstantInitializer(Init, DclT);
11220 // Otherwise, C++ does not restrict the initializer.
11221 } else if (getLangOpts().CPlusPlus) {
11224 // C99 6.7.8p4: All the expressions in an initializer for an object that has
11225 // static storage duration shall be constant expressions or string literals.
11226 } else if (VDecl->getStorageClass() == SC_Static) {
11227 CheckForConstantInitializer(Init, DclT);
11229 // C89 is stricter than C99 for aggregate initializers.
11230 // C89 6.5.7p3: All the expressions [...] in an initializer list
11231 // for an object that has aggregate or union type shall be
11232 // constant expressions.
11233 } else if (!getLangOpts().C99 && VDecl->getType()->isAggregateType() &&
11234 isa<InitListExpr>(Init)) {
11235 const Expr *Culprit;
11236 if (!Init->isConstantInitializer(Context, false, &Culprit)) {
11237 Diag(Culprit->getExprLoc(),
11238 diag::ext_aggregate_init_not_constant)
11239 << Culprit->getSourceRange();
11242 } else if (VDecl->isStaticDataMember() && !VDecl->isInline() &&
11243 VDecl->getLexicalDeclContext()->isRecord()) {
11244 // This is an in-class initialization for a static data member, e.g.,
11247 // static const int value = 17;
11250 // C++ [class.mem]p4:
11251 // A member-declarator can contain a constant-initializer only
11252 // if it declares a static member (9.4) of const integral or
11253 // const enumeration type, see 9.4.2.
11255 // C++11 [class.static.data]p3:
11256 // If a non-volatile non-inline const static data member is of integral
11257 // or enumeration type, its declaration in the class definition can
11258 // specify a brace-or-equal-initializer in which every initializer-clause
11259 // that is an assignment-expression is a constant expression. A static
11260 // data member of literal type can be declared in the class definition
11261 // with the constexpr specifier; if so, its declaration shall specify a
11262 // brace-or-equal-initializer in which every initializer-clause that is
11263 // an assignment-expression is a constant expression.
11265 // Do nothing on dependent types.
11266 if (DclT->isDependentType()) {
11268 // Allow any 'static constexpr' members, whether or not they are of literal
11269 // type. We separately check that every constexpr variable is of literal
11271 } else if (VDecl->isConstexpr()) {
11273 // Require constness.
11274 } else if (!DclT.isConstQualified()) {
11275 Diag(VDecl->getLocation(), diag::err_in_class_initializer_non_const)
11276 << Init->getSourceRange();
11277 VDecl->setInvalidDecl();
11279 // We allow integer constant expressions in all cases.
11280 } else if (DclT->isIntegralOrEnumerationType()) {
11281 // Check whether the expression is a constant expression.
11282 SourceLocation Loc;
11283 if (getLangOpts().CPlusPlus11 && DclT.isVolatileQualified())
11284 // In C++11, a non-constexpr const static data member with an
11285 // in-class initializer cannot be volatile.
11286 Diag(VDecl->getLocation(), diag::err_in_class_initializer_volatile);
11287 else if (Init->isValueDependent())
11288 ; // Nothing to check.
11289 else if (Init->isIntegerConstantExpr(Context, &Loc))
11290 ; // Ok, it's an ICE!
11291 else if (Init->getType()->isScopedEnumeralType() &&
11292 Init->isCXX11ConstantExpr(Context))
11293 ; // Ok, it is a scoped-enum constant expression.
11294 else if (Init->isEvaluatable(Context)) {
11295 // If we can constant fold the initializer through heroics, accept it,
11296 // but report this as a use of an extension for -pedantic.
11297 Diag(Loc, diag::ext_in_class_initializer_non_constant)
11298 << Init->getSourceRange();
11300 // Otherwise, this is some crazy unknown case. Report the issue at the
11301 // location provided by the isIntegerConstantExpr failed check.
11302 Diag(Loc, diag::err_in_class_initializer_non_constant)
11303 << Init->getSourceRange();
11304 VDecl->setInvalidDecl();
11307 // We allow foldable floating-point constants as an extension.
11308 } else if (DclT->isFloatingType()) { // also permits complex, which is ok
11309 // In C++98, this is a GNU extension. In C++11, it is not, but we support
11310 // it anyway and provide a fixit to add the 'constexpr'.
11311 if (getLangOpts().CPlusPlus11) {
11312 Diag(VDecl->getLocation(),
11313 diag::ext_in_class_initializer_float_type_cxx11)
11314 << DclT << Init->getSourceRange();
11315 Diag(VDecl->getLocStart(),
11316 diag::note_in_class_initializer_float_type_cxx11)
11317 << FixItHint::CreateInsertion(VDecl->getLocStart(), "constexpr ");
11319 Diag(VDecl->getLocation(), diag::ext_in_class_initializer_float_type)
11320 << DclT << Init->getSourceRange();
11322 if (!Init->isValueDependent() && !Init->isEvaluatable(Context)) {
11323 Diag(Init->getExprLoc(), diag::err_in_class_initializer_non_constant)
11324 << Init->getSourceRange();
11325 VDecl->setInvalidDecl();
11329 // Suggest adding 'constexpr' in C++11 for literal types.
11330 } else if (getLangOpts().CPlusPlus11 && DclT->isLiteralType(Context)) {
11331 Diag(VDecl->getLocation(), diag::err_in_class_initializer_literal_type)
11332 << DclT << Init->getSourceRange()
11333 << FixItHint::CreateInsertion(VDecl->getLocStart(), "constexpr ");
11334 VDecl->setConstexpr(true);
11337 Diag(VDecl->getLocation(), diag::err_in_class_initializer_bad_type)
11338 << DclT << Init->getSourceRange();
11339 VDecl->setInvalidDecl();
11341 } else if (VDecl->isFileVarDecl()) {
11342 // In C, extern is typically used to avoid tentative definitions when
11343 // declaring variables in headers, but adding an intializer makes it a
11344 // definition. This is somewhat confusing, so GCC and Clang both warn on it.
11345 // In C++, extern is often used to give implictly static const variables
11346 // external linkage, so don't warn in that case. If selectany is present,
11347 // this might be header code intended for C and C++ inclusion, so apply the
11349 if (VDecl->getStorageClass() == SC_Extern &&
11350 ((!getLangOpts().CPlusPlus && !VDecl->hasAttr<SelectAnyAttr>()) ||
11351 !Context.getBaseElementType(VDecl->getType()).isConstQualified()) &&
11352 !(getLangOpts().CPlusPlus && VDecl->isExternC()) &&
11353 !isTemplateInstantiation(VDecl->getTemplateSpecializationKind()))
11354 Diag(VDecl->getLocation(), diag::warn_extern_init);
11356 // C99 6.7.8p4. All file scoped initializers need to be constant.
11357 if (!getLangOpts().CPlusPlus && !VDecl->isInvalidDecl())
11358 CheckForConstantInitializer(Init, DclT);
11361 // We will represent direct-initialization similarly to copy-initialization:
11362 // int x(1); -as-> int x = 1;
11363 // ClassType x(a,b,c); -as-> ClassType x = ClassType(a,b,c);
11365 // Clients that want to distinguish between the two forms, can check for
11366 // direct initializer using VarDecl::getInitStyle().
11367 // A major benefit is that clients that don't particularly care about which
11368 // exactly form was it (like the CodeGen) can handle both cases without
11369 // special case code.
11372 // The form of initialization (using parentheses or '=') is generally
11373 // insignificant, but does matter when the entity being initialized has a
11375 if (CXXDirectInit) {
11376 assert(DirectInit && "Call-style initializer must be direct init.");
11377 VDecl->setInitStyle(VarDecl::CallInit);
11378 } else if (DirectInit) {
11379 // This must be list-initialization. No other way is direct-initialization.
11380 VDecl->setInitStyle(VarDecl::ListInit);
11383 CheckCompleteVariableDeclaration(VDecl);
11386 /// ActOnInitializerError - Given that there was an error parsing an
11387 /// initializer for the given declaration, try to return to some form
11389 void Sema::ActOnInitializerError(Decl *D) {
11390 // Our main concern here is re-establishing invariants like "a
11391 // variable's type is either dependent or complete".
11392 if (!D || D->isInvalidDecl()) return;
11394 VarDecl *VD = dyn_cast<VarDecl>(D);
11397 // Bindings are not usable if we can't make sense of the initializer.
11398 if (auto *DD = dyn_cast<DecompositionDecl>(D))
11399 for (auto *BD : DD->bindings())
11400 BD->setInvalidDecl();
11402 // Auto types are meaningless if we can't make sense of the initializer.
11403 if (ParsingInitForAutoVars.count(D)) {
11404 D->setInvalidDecl();
11408 QualType Ty = VD->getType();
11409 if (Ty->isDependentType()) return;
11411 // Require a complete type.
11412 if (RequireCompleteType(VD->getLocation(),
11413 Context.getBaseElementType(Ty),
11414 diag::err_typecheck_decl_incomplete_type)) {
11415 VD->setInvalidDecl();
11419 // Require a non-abstract type.
11420 if (RequireNonAbstractType(VD->getLocation(), Ty,
11421 diag::err_abstract_type_in_decl,
11422 AbstractVariableType)) {
11423 VD->setInvalidDecl();
11427 // Don't bother complaining about constructors or destructors,
11431 void Sema::ActOnUninitializedDecl(Decl *RealDecl) {
11432 // If there is no declaration, there was an error parsing it. Just ignore it.
11436 if (VarDecl *Var = dyn_cast<VarDecl>(RealDecl)) {
11437 QualType Type = Var->getType();
11439 // C++1z [dcl.dcl]p1 grammar implies that an initializer is mandatory.
11440 if (isa<DecompositionDecl>(RealDecl)) {
11441 Diag(Var->getLocation(), diag::err_decomp_decl_requires_init) << Var;
11442 Var->setInvalidDecl();
11446 if (Type->isUndeducedType() &&
11447 DeduceVariableDeclarationType(Var, false, nullptr))
11450 // C++11 [class.static.data]p3: A static data member can be declared with
11451 // the constexpr specifier; if so, its declaration shall specify
11452 // a brace-or-equal-initializer.
11453 // C++11 [dcl.constexpr]p1: The constexpr specifier shall be applied only to
11454 // the definition of a variable [...] or the declaration of a static data
11456 if (Var->isConstexpr() && !Var->isThisDeclarationADefinition() &&
11457 !Var->isThisDeclarationADemotedDefinition()) {
11458 if (Var->isStaticDataMember()) {
11459 // C++1z removes the relevant rule; the in-class declaration is always
11460 // a definition there.
11461 if (!getLangOpts().CPlusPlus17) {
11462 Diag(Var->getLocation(),
11463 diag::err_constexpr_static_mem_var_requires_init)
11464 << Var->getDeclName();
11465 Var->setInvalidDecl();
11469 Diag(Var->getLocation(), diag::err_invalid_constexpr_var_decl);
11470 Var->setInvalidDecl();
11475 // OpenCL v1.1 s6.5.3: variables declared in the constant address space must
11477 if (!Var->isInvalidDecl() &&
11478 Var->getType().getAddressSpace() == LangAS::opencl_constant &&
11479 Var->getStorageClass() != SC_Extern && !Var->getInit()) {
11480 Diag(Var->getLocation(), diag::err_opencl_constant_no_init);
11481 Var->setInvalidDecl();
11485 switch (Var->isThisDeclarationADefinition()) {
11486 case VarDecl::Definition:
11487 if (!Var->isStaticDataMember() || !Var->getAnyInitializer())
11490 // We have an out-of-line definition of a static data member
11491 // that has an in-class initializer, so we type-check this like
11496 case VarDecl::DeclarationOnly:
11497 // It's only a declaration.
11499 // Block scope. C99 6.7p7: If an identifier for an object is
11500 // declared with no linkage (C99 6.2.2p6), the type for the
11501 // object shall be complete.
11502 if (!Type->isDependentType() && Var->isLocalVarDecl() &&
11503 !Var->hasLinkage() && !Var->isInvalidDecl() &&
11504 RequireCompleteType(Var->getLocation(), Type,
11505 diag::err_typecheck_decl_incomplete_type))
11506 Var->setInvalidDecl();
11508 // Make sure that the type is not abstract.
11509 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
11510 RequireNonAbstractType(Var->getLocation(), Type,
11511 diag::err_abstract_type_in_decl,
11512 AbstractVariableType))
11513 Var->setInvalidDecl();
11514 if (!Type->isDependentType() && !Var->isInvalidDecl() &&
11515 Var->getStorageClass() == SC_PrivateExtern) {
11516 Diag(Var->getLocation(), diag::warn_private_extern);
11517 Diag(Var->getLocation(), diag::note_private_extern);
11522 case VarDecl::TentativeDefinition:
11523 // File scope. C99 6.9.2p2: A declaration of an identifier for an
11524 // object that has file scope without an initializer, and without a
11525 // storage-class specifier or with the storage-class specifier "static",
11526 // constitutes a tentative definition. Note: A tentative definition with
11527 // external linkage is valid (C99 6.2.2p5).
11528 if (!Var->isInvalidDecl()) {
11529 if (const IncompleteArrayType *ArrayT
11530 = Context.getAsIncompleteArrayType(Type)) {
11531 if (RequireCompleteType(Var->getLocation(),
11532 ArrayT->getElementType(),
11533 diag::err_illegal_decl_array_incomplete_type))
11534 Var->setInvalidDecl();
11535 } else if (Var->getStorageClass() == SC_Static) {
11536 // C99 6.9.2p3: If the declaration of an identifier for an object is
11537 // a tentative definition and has internal linkage (C99 6.2.2p3), the
11538 // declared type shall not be an incomplete type.
11539 // NOTE: code such as the following
11540 // static struct s;
11541 // struct s { int a; };
11542 // is accepted by gcc. Hence here we issue a warning instead of
11543 // an error and we do not invalidate the static declaration.
11544 // NOTE: to avoid multiple warnings, only check the first declaration.
11545 if (Var->isFirstDecl())
11546 RequireCompleteType(Var->getLocation(), Type,
11547 diag::ext_typecheck_decl_incomplete_type);
11551 // Record the tentative definition; we're done.
11552 if (!Var->isInvalidDecl())
11553 TentativeDefinitions.push_back(Var);
11557 // Provide a specific diagnostic for uninitialized variable
11558 // definitions with incomplete array type.
11559 if (Type->isIncompleteArrayType()) {
11560 Diag(Var->getLocation(),
11561 diag::err_typecheck_incomplete_array_needs_initializer);
11562 Var->setInvalidDecl();
11566 // Provide a specific diagnostic for uninitialized variable
11567 // definitions with reference type.
11568 if (Type->isReferenceType()) {
11569 Diag(Var->getLocation(), diag::err_reference_var_requires_init)
11570 << Var->getDeclName()
11571 << SourceRange(Var->getLocation(), Var->getLocation());
11572 Var->setInvalidDecl();
11576 // Do not attempt to type-check the default initializer for a
11577 // variable with dependent type.
11578 if (Type->isDependentType())
11581 if (Var->isInvalidDecl())
11584 if (!Var->hasAttr<AliasAttr>()) {
11585 if (RequireCompleteType(Var->getLocation(),
11586 Context.getBaseElementType(Type),
11587 diag::err_typecheck_decl_incomplete_type)) {
11588 Var->setInvalidDecl();
11595 // The variable can not have an abstract class type.
11596 if (RequireNonAbstractType(Var->getLocation(), Type,
11597 diag::err_abstract_type_in_decl,
11598 AbstractVariableType)) {
11599 Var->setInvalidDecl();
11603 // Check for jumps past the implicit initializer. C++0x
11604 // clarifies that this applies to a "variable with automatic
11605 // storage duration", not a "local variable".
11606 // C++11 [stmt.dcl]p3
11607 // A program that jumps from a point where a variable with automatic
11608 // storage duration is not in scope to a point where it is in scope is
11609 // ill-formed unless the variable has scalar type, class type with a
11610 // trivial default constructor and a trivial destructor, a cv-qualified
11611 // version of one of these types, or an array of one of the preceding
11612 // types and is declared without an initializer.
11613 if (getLangOpts().CPlusPlus && Var->hasLocalStorage()) {
11614 if (const RecordType *Record
11615 = Context.getBaseElementType(Type)->getAs<RecordType>()) {
11616 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record->getDecl());
11617 // Mark the function (if we're in one) for further checking even if the
11618 // looser rules of C++11 do not require such checks, so that we can
11619 // diagnose incompatibilities with C++98.
11620 if (!CXXRecord->isPOD())
11621 setFunctionHasBranchProtectedScope();
11625 // C++03 [dcl.init]p9:
11626 // If no initializer is specified for an object, and the
11627 // object is of (possibly cv-qualified) non-POD class type (or
11628 // array thereof), the object shall be default-initialized; if
11629 // the object is of const-qualified type, the underlying class
11630 // type shall have a user-declared default
11631 // constructor. Otherwise, if no initializer is specified for
11632 // a non- static object, the object and its subobjects, if
11633 // any, have an indeterminate initial value); if the object
11634 // or any of its subobjects are of const-qualified type, the
11635 // program is ill-formed.
11636 // C++0x [dcl.init]p11:
11637 // If no initializer is specified for an object, the object is
11638 // default-initialized; [...].
11639 InitializedEntity Entity = InitializedEntity::InitializeVariable(Var);
11640 InitializationKind Kind
11641 = InitializationKind::CreateDefault(Var->getLocation());
11643 InitializationSequence InitSeq(*this, Entity, Kind, None);
11644 ExprResult Init = InitSeq.Perform(*this, Entity, Kind, None);
11645 if (Init.isInvalid())
11646 Var->setInvalidDecl();
11647 else if (Init.get()) {
11648 Var->setInit(MaybeCreateExprWithCleanups(Init.get()));
11649 // This is important for template substitution.
11650 Var->setInitStyle(VarDecl::CallInit);
11653 CheckCompleteVariableDeclaration(Var);
11657 void Sema::ActOnCXXForRangeDecl(Decl *D) {
11658 // If there is no declaration, there was an error parsing it. Ignore it.
11662 VarDecl *VD = dyn_cast<VarDecl>(D);
11664 Diag(D->getLocation(), diag::err_for_range_decl_must_be_var);
11665 D->setInvalidDecl();
11669 VD->setCXXForRangeDecl(true);
11671 // for-range-declaration cannot be given a storage class specifier.
11673 switch (VD->getStorageClass()) {
11682 case SC_PrivateExtern:
11693 Diag(VD->getOuterLocStart(), diag::err_for_range_storage_class)
11694 << VD->getDeclName() << Error;
11695 D->setInvalidDecl();
11700 Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
11701 IdentifierInfo *Ident,
11702 ParsedAttributes &Attrs,
11703 SourceLocation AttrEnd) {
11704 // C++1y [stmt.iter]p1:
11705 // A range-based for statement of the form
11706 // for ( for-range-identifier : for-range-initializer ) statement
11707 // is equivalent to
11708 // for ( auto&& for-range-identifier : for-range-initializer ) statement
11709 DeclSpec DS(Attrs.getPool().getFactory());
11711 const char *PrevSpec;
11713 DS.SetTypeSpecType(DeclSpec::TST_auto, IdentLoc, PrevSpec, DiagID,
11714 getPrintingPolicy());
11716 Declarator D(DS, DeclaratorContext::ForContext);
11717 D.SetIdentifier(Ident, IdentLoc);
11718 D.takeAttributes(Attrs, AttrEnd);
11720 ParsedAttributes EmptyAttrs(Attrs.getPool().getFactory());
11721 D.AddTypeInfo(DeclaratorChunk::getReference(0, IdentLoc, /*lvalue*/ false),
11723 Decl *Var = ActOnDeclarator(S, D);
11724 cast<VarDecl>(Var)->setCXXForRangeDecl(true);
11725 FinalizeDeclaration(Var);
11726 return ActOnDeclStmt(FinalizeDeclaratorGroup(S, DS, Var), IdentLoc,
11727 AttrEnd.isValid() ? AttrEnd : IdentLoc);
11730 void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
11731 if (var->isInvalidDecl()) return;
11733 if (getLangOpts().OpenCL) {
11734 // OpenCL v2.0 s6.12.5 - Every block variable declaration must have an
11736 if (var->getTypeSourceInfo()->getType()->isBlockPointerType() &&
11738 Diag(var->getLocation(), diag::err_opencl_invalid_block_declaration)
11740 var->setInvalidDecl();
11745 // In Objective-C, don't allow jumps past the implicit initialization of a
11746 // local retaining variable.
11747 if (getLangOpts().ObjC1 &&
11748 var->hasLocalStorage()) {
11749 switch (var->getType().getObjCLifetime()) {
11750 case Qualifiers::OCL_None:
11751 case Qualifiers::OCL_ExplicitNone:
11752 case Qualifiers::OCL_Autoreleasing:
11755 case Qualifiers::OCL_Weak:
11756 case Qualifiers::OCL_Strong:
11757 setFunctionHasBranchProtectedScope();
11762 if (var->hasLocalStorage() &&
11763 var->getType().isDestructedType() == QualType::DK_nontrivial_c_struct)
11764 setFunctionHasBranchProtectedScope();
11766 // Warn about externally-visible variables being defined without a
11767 // prior declaration. We only want to do this for global
11768 // declarations, but we also specifically need to avoid doing it for
11769 // class members because the linkage of an anonymous class can
11770 // change if it's later given a typedef name.
11771 if (var->isThisDeclarationADefinition() &&
11772 var->getDeclContext()->getRedeclContext()->isFileContext() &&
11773 var->isExternallyVisible() && var->hasLinkage() &&
11774 !var->isInline() && !var->getDescribedVarTemplate() &&
11775 !isTemplateInstantiation(var->getTemplateSpecializationKind()) &&
11776 !getDiagnostics().isIgnored(diag::warn_missing_variable_declarations,
11777 var->getLocation())) {
11778 // Find a previous declaration that's not a definition.
11779 VarDecl *prev = var->getPreviousDecl();
11780 while (prev && prev->isThisDeclarationADefinition())
11781 prev = prev->getPreviousDecl();
11784 Diag(var->getLocation(), diag::warn_missing_variable_declarations) << var;
11787 // Cache the result of checking for constant initialization.
11788 Optional<bool> CacheHasConstInit;
11789 const Expr *CacheCulprit;
11790 auto checkConstInit = [&]() mutable {
11791 if (!CacheHasConstInit)
11792 CacheHasConstInit = var->getInit()->isConstantInitializer(
11793 Context, var->getType()->isReferenceType(), &CacheCulprit);
11794 return *CacheHasConstInit;
11797 if (var->getTLSKind() == VarDecl::TLS_Static) {
11798 if (var->getType().isDestructedType()) {
11799 // GNU C++98 edits for __thread, [basic.start.term]p3:
11800 // The type of an object with thread storage duration shall not
11801 // have a non-trivial destructor.
11802 Diag(var->getLocation(), diag::err_thread_nontrivial_dtor);
11803 if (getLangOpts().CPlusPlus11)
11804 Diag(var->getLocation(), diag::note_use_thread_local);
11805 } else if (getLangOpts().CPlusPlus && var->hasInit()) {
11806 if (!checkConstInit()) {
11807 // GNU C++98 edits for __thread, [basic.start.init]p4:
11808 // An object of thread storage duration shall not require dynamic
11810 // FIXME: Need strict checking here.
11811 Diag(CacheCulprit->getExprLoc(), diag::err_thread_dynamic_init)
11812 << CacheCulprit->getSourceRange();
11813 if (getLangOpts().CPlusPlus11)
11814 Diag(var->getLocation(), diag::note_use_thread_local);
11819 // Apply section attributes and pragmas to global variables.
11820 bool GlobalStorage = var->hasGlobalStorage();
11821 if (GlobalStorage && var->isThisDeclarationADefinition() &&
11822 !inTemplateInstantiation()) {
11823 PragmaStack<StringLiteral *> *Stack = nullptr;
11824 int SectionFlags = ASTContext::PSF_Implicit | ASTContext::PSF_Read;
11825 if (var->getType().isConstQualified())
11826 Stack = &ConstSegStack;
11827 else if (!var->getInit()) {
11828 Stack = &BSSSegStack;
11829 SectionFlags |= ASTContext::PSF_Write;
11831 Stack = &DataSegStack;
11832 SectionFlags |= ASTContext::PSF_Write;
11834 if (Stack->CurrentValue && !var->hasAttr<SectionAttr>()) {
11835 var->addAttr(SectionAttr::CreateImplicit(
11836 Context, SectionAttr::Declspec_allocate,
11837 Stack->CurrentValue->getString(), Stack->CurrentPragmaLocation));
11839 if (const SectionAttr *SA = var->getAttr<SectionAttr>())
11840 if (UnifySection(SA->getName(), SectionFlags, var))
11841 var->dropAttr<SectionAttr>();
11843 // Apply the init_seg attribute if this has an initializer. If the
11844 // initializer turns out to not be dynamic, we'll end up ignoring this
11846 if (CurInitSeg && var->getInit())
11847 var->addAttr(InitSegAttr::CreateImplicit(Context, CurInitSeg->getString(),
11851 // All the following checks are C++ only.
11852 if (!getLangOpts().CPlusPlus) {
11853 // If this variable must be emitted, add it as an initializer for the
11855 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
11856 Context.addModuleInitializer(ModuleScopes.back().Module, var);
11860 if (auto *DD = dyn_cast<DecompositionDecl>(var))
11861 CheckCompleteDecompositionDeclaration(DD);
11863 QualType type = var->getType();
11864 if (type->isDependentType()) return;
11866 // __block variables might require us to capture a copy-initializer.
11867 if (var->hasAttr<BlocksAttr>()) {
11868 // It's currently invalid to ever have a __block variable with an
11869 // array type; should we diagnose that here?
11871 // Regardless, we don't want to ignore array nesting when
11872 // constructing this copy.
11873 if (type->isStructureOrClassType()) {
11874 EnterExpressionEvaluationContext scope(
11875 *this, ExpressionEvaluationContext::PotentiallyEvaluated);
11876 SourceLocation poi = var->getLocation();
11877 Expr *varRef =new (Context) DeclRefExpr(var, false, type, VK_LValue, poi);
11879 = PerformMoveOrCopyInitialization(
11880 InitializedEntity::InitializeBlock(poi, type, false),
11881 var, var->getType(), varRef, /*AllowNRVO=*/true);
11882 if (!result.isInvalid()) {
11883 result = MaybeCreateExprWithCleanups(result);
11884 Expr *init = result.getAs<Expr>();
11885 Context.setBlockVarCopyInits(var, init);
11890 Expr *Init = var->getInit();
11891 bool IsGlobal = GlobalStorage && !var->isStaticLocal();
11892 QualType baseType = Context.getBaseElementType(type);
11894 if (Init && !Init->isValueDependent()) {
11895 if (var->isConstexpr()) {
11896 SmallVector<PartialDiagnosticAt, 8> Notes;
11897 if (!var->evaluateValue(Notes) || !var->isInitICE()) {
11898 SourceLocation DiagLoc = var->getLocation();
11899 // If the note doesn't add any useful information other than a source
11900 // location, fold it into the primary diagnostic.
11901 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
11902 diag::note_invalid_subexpr_in_const_expr) {
11903 DiagLoc = Notes[0].first;
11906 Diag(DiagLoc, diag::err_constexpr_var_requires_const_init)
11907 << var << Init->getSourceRange();
11908 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
11909 Diag(Notes[I].first, Notes[I].second);
11911 } else if (var->isUsableInConstantExpressions(Context)) {
11912 // Check whether the initializer of a const variable of integral or
11913 // enumeration type is an ICE now, since we can't tell whether it was
11914 // initialized by a constant expression if we check later.
11915 var->checkInitIsICE();
11918 // Don't emit further diagnostics about constexpr globals since they
11919 // were just diagnosed.
11920 if (!var->isConstexpr() && GlobalStorage &&
11921 var->hasAttr<RequireConstantInitAttr>()) {
11922 // FIXME: Need strict checking in C++03 here.
11923 bool DiagErr = getLangOpts().CPlusPlus11
11924 ? !var->checkInitIsICE() : !checkConstInit();
11926 auto attr = var->getAttr<RequireConstantInitAttr>();
11927 Diag(var->getLocation(), diag::err_require_constant_init_failed)
11928 << Init->getSourceRange();
11929 Diag(attr->getLocation(), diag::note_declared_required_constant_init_here)
11930 << attr->getRange();
11931 if (getLangOpts().CPlusPlus11) {
11933 SmallVector<PartialDiagnosticAt, 8> Notes;
11934 Init->EvaluateAsInitializer(Value, getASTContext(), var, Notes);
11935 for (auto &it : Notes)
11936 Diag(it.first, it.second);
11938 Diag(CacheCulprit->getExprLoc(),
11939 diag::note_invalid_subexpr_in_const_expr)
11940 << CacheCulprit->getSourceRange();
11944 else if (!var->isConstexpr() && IsGlobal &&
11945 !getDiagnostics().isIgnored(diag::warn_global_constructor,
11946 var->getLocation())) {
11947 // Warn about globals which don't have a constant initializer. Don't
11948 // warn about globals with a non-trivial destructor because we already
11949 // warned about them.
11950 CXXRecordDecl *RD = baseType->getAsCXXRecordDecl();
11951 if (!(RD && !RD->hasTrivialDestructor())) {
11952 if (!checkConstInit())
11953 Diag(var->getLocation(), diag::warn_global_constructor)
11954 << Init->getSourceRange();
11959 // Require the destructor.
11960 if (const RecordType *recordType = baseType->getAs<RecordType>())
11961 FinalizeVarWithDestructor(var, recordType);
11963 // If this variable must be emitted, add it as an initializer for the current
11965 if (Context.DeclMustBeEmitted(var) && !ModuleScopes.empty())
11966 Context.addModuleInitializer(ModuleScopes.back().Module, var);
11969 /// Determines if a variable's alignment is dependent.
11970 static bool hasDependentAlignment(VarDecl *VD) {
11971 if (VD->getType()->isDependentType())
11973 for (auto *I : VD->specific_attrs<AlignedAttr>())
11974 if (I->isAlignmentDependent())
11979 /// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform
11980 /// any semantic actions necessary after any initializer has been attached.
11981 void Sema::FinalizeDeclaration(Decl *ThisDecl) {
11982 // Note that we are no longer parsing the initializer for this declaration.
11983 ParsingInitForAutoVars.erase(ThisDecl);
11985 VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDecl);
11989 // Apply an implicit SectionAttr if '#pragma clang section bss|data|rodata' is active
11990 if (VD->hasGlobalStorage() && VD->isThisDeclarationADefinition() &&
11991 !inTemplateInstantiation() && !VD->hasAttr<SectionAttr>()) {
11992 if (PragmaClangBSSSection.Valid)
11993 VD->addAttr(PragmaClangBSSSectionAttr::CreateImplicit(Context,
11994 PragmaClangBSSSection.SectionName,
11995 PragmaClangBSSSection.PragmaLocation));
11996 if (PragmaClangDataSection.Valid)
11997 VD->addAttr(PragmaClangDataSectionAttr::CreateImplicit(Context,
11998 PragmaClangDataSection.SectionName,
11999 PragmaClangDataSection.PragmaLocation));
12000 if (PragmaClangRodataSection.Valid)
12001 VD->addAttr(PragmaClangRodataSectionAttr::CreateImplicit(Context,
12002 PragmaClangRodataSection.SectionName,
12003 PragmaClangRodataSection.PragmaLocation));
12006 if (auto *DD = dyn_cast<DecompositionDecl>(ThisDecl)) {
12007 for (auto *BD : DD->bindings()) {
12008 FinalizeDeclaration(BD);
12012 checkAttributesAfterMerging(*this, *VD);
12014 // Perform TLS alignment check here after attributes attached to the variable
12015 // which may affect the alignment have been processed. Only perform the check
12016 // if the target has a maximum TLS alignment (zero means no constraints).
12017 if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
12018 // Protect the check so that it's not performed on dependent types and
12019 // dependent alignments (we can't determine the alignment in that case).
12020 if (VD->getTLSKind() && !hasDependentAlignment(VD) &&
12021 !VD->isInvalidDecl()) {
12022 CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign);
12023 if (Context.getDeclAlign(VD) > MaxAlignChars) {
12024 Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum)
12025 << (unsigned)Context.getDeclAlign(VD).getQuantity() << VD
12026 << (unsigned)MaxAlignChars.getQuantity();
12031 if (VD->isStaticLocal()) {
12032 if (FunctionDecl *FD =
12033 dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod())) {
12034 // Static locals inherit dll attributes from their function.
12035 if (Attr *A = getDLLAttr(FD)) {
12036 auto *NewAttr = cast<InheritableAttr>(A->clone(getASTContext()));
12037 NewAttr->setInherited(true);
12038 VD->addAttr(NewAttr);
12040 // CUDA 8.0 E.3.9.4: Within the body of a __device__ or __global__
12041 // function, only __shared__ variables or variables without any device
12042 // memory qualifiers may be declared with static storage class.
12043 // Note: It is unclear how a function-scope non-const static variable
12044 // without device memory qualifier is implemented, therefore only static
12045 // const variable without device memory qualifier is allowed.
12047 if (!getLangOpts().CUDA)
12049 if (VD->hasAttr<CUDASharedAttr>())
12051 if (VD->getType().isConstQualified() &&
12052 !(VD->hasAttr<CUDADeviceAttr>() || VD->hasAttr<CUDAConstantAttr>()))
12054 if (CUDADiagIfDeviceCode(VD->getLocation(),
12055 diag::err_device_static_local_var)
12056 << CurrentCUDATarget())
12057 VD->setInvalidDecl();
12062 // Perform check for initializers of device-side global variables.
12063 // CUDA allows empty constructors as initializers (see E.2.3.1, CUDA
12064 // 7.5). We must also apply the same checks to all __shared__
12065 // variables whether they are local or not. CUDA also allows
12066 // constant initializers for __constant__ and __device__ variables.
12067 if (getLangOpts().CUDA)
12068 checkAllowedCUDAInitializer(VD);
12070 // Grab the dllimport or dllexport attribute off of the VarDecl.
12071 const InheritableAttr *DLLAttr = getDLLAttr(VD);
12073 // Imported static data members cannot be defined out-of-line.
12074 if (const auto *IA = dyn_cast_or_null<DLLImportAttr>(DLLAttr)) {
12075 if (VD->isStaticDataMember() && VD->isOutOfLine() &&
12076 VD->isThisDeclarationADefinition()) {
12077 // We allow definitions of dllimport class template static data members
12079 CXXRecordDecl *Context =
12080 cast<CXXRecordDecl>(VD->getFirstDecl()->getDeclContext());
12081 bool IsClassTemplateMember =
12082 isa<ClassTemplatePartialSpecializationDecl>(Context) ||
12083 Context->getDescribedClassTemplate();
12085 Diag(VD->getLocation(),
12086 IsClassTemplateMember
12087 ? diag::warn_attribute_dllimport_static_field_definition
12088 : diag::err_attribute_dllimport_static_field_definition);
12089 Diag(IA->getLocation(), diag::note_attribute);
12090 if (!IsClassTemplateMember)
12091 VD->setInvalidDecl();
12095 // dllimport/dllexport variables cannot be thread local, their TLS index
12096 // isn't exported with the variable.
12097 if (DLLAttr && VD->getTLSKind()) {
12098 auto *F = dyn_cast_or_null<FunctionDecl>(VD->getParentFunctionOrMethod());
12099 if (F && getDLLAttr(F)) {
12100 assert(VD->isStaticLocal());
12101 // But if this is a static local in a dlimport/dllexport function, the
12102 // function will never be inlined, which means the var would never be
12103 // imported, so having it marked import/export is safe.
12105 Diag(VD->getLocation(), diag::err_attribute_dll_thread_local) << VD
12107 VD->setInvalidDecl();
12111 if (UsedAttr *Attr = VD->getAttr<UsedAttr>()) {
12112 if (!Attr->isInherited() && !VD->isThisDeclarationADefinition()) {
12113 Diag(Attr->getLocation(), diag::warn_attribute_ignored) << Attr;
12114 VD->dropAttr<UsedAttr>();
12118 const DeclContext *DC = VD->getDeclContext();
12119 // If there's a #pragma GCC visibility in scope, and this isn't a class
12120 // member, set the visibility of this variable.
12121 if (DC->getRedeclContext()->isFileContext() && VD->isExternallyVisible())
12122 AddPushedVisibilityAttribute(VD);
12124 // FIXME: Warn on unused var template partial specializations.
12125 if (VD->isFileVarDecl() && !isa<VarTemplatePartialSpecializationDecl>(VD))
12126 MarkUnusedFileScopedDecl(VD);
12128 // Now we have parsed the initializer and can update the table of magic
12130 if (!VD->hasAttr<TypeTagForDatatypeAttr>() ||
12131 !VD->getType()->isIntegralOrEnumerationType())
12134 for (const auto *I : ThisDecl->specific_attrs<TypeTagForDatatypeAttr>()) {
12135 const Expr *MagicValueExpr = VD->getInit();
12136 if (!MagicValueExpr) {
12139 llvm::APSInt MagicValueInt;
12140 if (!MagicValueExpr->isIntegerConstantExpr(MagicValueInt, Context)) {
12141 Diag(I->getRange().getBegin(),
12142 diag::err_type_tag_for_datatype_not_ice)
12143 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
12146 if (MagicValueInt.getActiveBits() > 64) {
12147 Diag(I->getRange().getBegin(),
12148 diag::err_type_tag_for_datatype_too_large)
12149 << LangOpts.CPlusPlus << MagicValueExpr->getSourceRange();
12152 uint64_t MagicValue = MagicValueInt.getZExtValue();
12153 RegisterTypeTagForDatatype(I->getArgumentKind(),
12155 I->getMatchingCType(),
12156 I->getLayoutCompatible(),
12157 I->getMustBeNull());
12161 static bool hasDeducedAuto(DeclaratorDecl *DD) {
12162 auto *VD = dyn_cast<VarDecl>(DD);
12163 return VD && !VD->getType()->hasAutoForTrailingReturnType();
12166 Sema::DeclGroupPtrTy Sema::FinalizeDeclaratorGroup(Scope *S, const DeclSpec &DS,
12167 ArrayRef<Decl *> Group) {
12168 SmallVector<Decl*, 8> Decls;
12170 if (DS.isTypeSpecOwned())
12171 Decls.push_back(DS.getRepAsDecl());
12173 DeclaratorDecl *FirstDeclaratorInGroup = nullptr;
12174 DecompositionDecl *FirstDecompDeclaratorInGroup = nullptr;
12175 bool DiagnosedMultipleDecomps = false;
12176 DeclaratorDecl *FirstNonDeducedAutoInGroup = nullptr;
12177 bool DiagnosedNonDeducedAuto = false;
12179 for (unsigned i = 0, e = Group.size(); i != e; ++i) {
12180 if (Decl *D = Group[i]) {
12181 // For declarators, there are some additional syntactic-ish checks we need
12183 if (auto *DD = dyn_cast<DeclaratorDecl>(D)) {
12184 if (!FirstDeclaratorInGroup)
12185 FirstDeclaratorInGroup = DD;
12186 if (!FirstDecompDeclaratorInGroup)
12187 FirstDecompDeclaratorInGroup = dyn_cast<DecompositionDecl>(D);
12188 if (!FirstNonDeducedAutoInGroup && DS.hasAutoTypeSpec() &&
12189 !hasDeducedAuto(DD))
12190 FirstNonDeducedAutoInGroup = DD;
12192 if (FirstDeclaratorInGroup != DD) {
12193 // A decomposition declaration cannot be combined with any other
12194 // declaration in the same group.
12195 if (FirstDecompDeclaratorInGroup && !DiagnosedMultipleDecomps) {
12196 Diag(FirstDecompDeclaratorInGroup->getLocation(),
12197 diag::err_decomp_decl_not_alone)
12198 << FirstDeclaratorInGroup->getSourceRange()
12199 << DD->getSourceRange();
12200 DiagnosedMultipleDecomps = true;
12203 // A declarator that uses 'auto' in any way other than to declare a
12204 // variable with a deduced type cannot be combined with any other
12205 // declarator in the same group.
12206 if (FirstNonDeducedAutoInGroup && !DiagnosedNonDeducedAuto) {
12207 Diag(FirstNonDeducedAutoInGroup->getLocation(),
12208 diag::err_auto_non_deduced_not_alone)
12209 << FirstNonDeducedAutoInGroup->getType()
12210 ->hasAutoForTrailingReturnType()
12211 << FirstDeclaratorInGroup->getSourceRange()
12212 << DD->getSourceRange();
12213 DiagnosedNonDeducedAuto = true;
12218 Decls.push_back(D);
12222 if (DeclSpec::isDeclRep(DS.getTypeSpecType())) {
12223 if (TagDecl *Tag = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl())) {
12224 handleTagNumbering(Tag, S);
12225 if (FirstDeclaratorInGroup && !Tag->hasNameForLinkage() &&
12226 getLangOpts().CPlusPlus)
12227 Context.addDeclaratorForUnnamedTagDecl(Tag, FirstDeclaratorInGroup);
12231 return BuildDeclaratorGroup(Decls);
12234 /// BuildDeclaratorGroup - convert a list of declarations into a declaration
12235 /// group, performing any necessary semantic checking.
12236 Sema::DeclGroupPtrTy
12237 Sema::BuildDeclaratorGroup(MutableArrayRef<Decl *> Group) {
12238 // C++14 [dcl.spec.auto]p7: (DR1347)
12239 // If the type that replaces the placeholder type is not the same in each
12240 // deduction, the program is ill-formed.
12241 if (Group.size() > 1) {
12243 VarDecl *DeducedDecl = nullptr;
12244 for (unsigned i = 0, e = Group.size(); i != e; ++i) {
12245 VarDecl *D = dyn_cast<VarDecl>(Group[i]);
12246 if (!D || D->isInvalidDecl())
12248 DeducedType *DT = D->getType()->getContainedDeducedType();
12249 if (!DT || DT->getDeducedType().isNull())
12251 if (Deduced.isNull()) {
12252 Deduced = DT->getDeducedType();
12254 } else if (!Context.hasSameType(DT->getDeducedType(), Deduced)) {
12255 auto *AT = dyn_cast<AutoType>(DT);
12256 Diag(D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
12257 diag::err_auto_different_deductions)
12258 << (AT ? (unsigned)AT->getKeyword() : 3)
12259 << Deduced << DeducedDecl->getDeclName()
12260 << DT->getDeducedType() << D->getDeclName()
12261 << DeducedDecl->getInit()->getSourceRange()
12262 << D->getInit()->getSourceRange();
12263 D->setInvalidDecl();
12269 ActOnDocumentableDecls(Group);
12271 return DeclGroupPtrTy::make(
12272 DeclGroupRef::Create(Context, Group.data(), Group.size()));
12275 void Sema::ActOnDocumentableDecl(Decl *D) {
12276 ActOnDocumentableDecls(D);
12279 void Sema::ActOnDocumentableDecls(ArrayRef<Decl *> Group) {
12280 // Don't parse the comment if Doxygen diagnostics are ignored.
12281 if (Group.empty() || !Group[0])
12284 if (Diags.isIgnored(diag::warn_doc_param_not_found,
12285 Group[0]->getLocation()) &&
12286 Diags.isIgnored(diag::warn_unknown_comment_command_name,
12287 Group[0]->getLocation()))
12290 if (Group.size() >= 2) {
12291 // This is a decl group. Normally it will contain only declarations
12292 // produced from declarator list. But in case we have any definitions or
12293 // additional declaration references:
12294 // 'typedef struct S {} S;'
12295 // 'typedef struct S *S;'
12297 // FinalizeDeclaratorGroup adds these as separate declarations.
12298 Decl *MaybeTagDecl = Group[0];
12299 if (MaybeTagDecl && isa<TagDecl>(MaybeTagDecl)) {
12300 Group = Group.slice(1);
12304 // See if there are any new comments that are not attached to a decl.
12305 ArrayRef<RawComment *> Comments = Context.getRawCommentList().getComments();
12306 if (!Comments.empty() &&
12307 !Comments.back()->isAttached()) {
12308 // There is at least one comment that not attached to a decl.
12309 // Maybe it should be attached to one of these decls?
12311 // Note that this way we pick up not only comments that precede the
12312 // declaration, but also comments that *follow* the declaration -- thanks to
12313 // the lookahead in the lexer: we've consumed the semicolon and looked
12314 // ahead through comments.
12315 for (unsigned i = 0, e = Group.size(); i != e; ++i)
12316 Context.getCommentForDecl(Group[i], &PP);
12320 /// ActOnParamDeclarator - Called from Parser::ParseFunctionDeclarator()
12321 /// to introduce parameters into function prototype scope.
12322 Decl *Sema::ActOnParamDeclarator(Scope *S, Declarator &D) {
12323 const DeclSpec &DS = D.getDeclSpec();
12325 // Verify C99 6.7.5.3p2: The only SCS allowed is 'register'.
12327 // C++03 [dcl.stc]p2 also permits 'auto'.
12328 StorageClass SC = SC_None;
12329 if (DS.getStorageClassSpec() == DeclSpec::SCS_register) {
12331 // In C++11, the 'register' storage class specifier is deprecated.
12332 // In C++17, it is not allowed, but we tolerate it as an extension.
12333 if (getLangOpts().CPlusPlus11) {
12334 Diag(DS.getStorageClassSpecLoc(),
12335 getLangOpts().CPlusPlus17 ? diag::ext_register_storage_class
12336 : diag::warn_deprecated_register)
12337 << FixItHint::CreateRemoval(DS.getStorageClassSpecLoc());
12339 } else if (getLangOpts().CPlusPlus &&
12340 DS.getStorageClassSpec() == DeclSpec::SCS_auto) {
12342 } else if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified) {
12343 Diag(DS.getStorageClassSpecLoc(),
12344 diag::err_invalid_storage_class_in_func_decl);
12345 D.getMutableDeclSpec().ClearStorageClassSpecs();
12348 if (DeclSpec::TSCS TSCS = DS.getThreadStorageClassSpec())
12349 Diag(DS.getThreadStorageClassSpecLoc(), diag::err_invalid_thread)
12350 << DeclSpec::getSpecifierName(TSCS);
12351 if (DS.isInlineSpecified())
12352 Diag(DS.getInlineSpecLoc(), diag::err_inline_non_function)
12353 << getLangOpts().CPlusPlus17;
12354 if (DS.isConstexprSpecified())
12355 Diag(DS.getConstexprSpecLoc(), diag::err_invalid_constexpr)
12358 DiagnoseFunctionSpecifiers(DS);
12360 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
12361 QualType parmDeclType = TInfo->getType();
12363 if (getLangOpts().CPlusPlus) {
12364 // Check that there are no default arguments inside the type of this
12366 CheckExtraCXXDefaultArguments(D);
12368 // Parameter declarators cannot be qualified (C++ [dcl.meaning]p1).
12369 if (D.getCXXScopeSpec().isSet()) {
12370 Diag(D.getIdentifierLoc(), diag::err_qualified_param_declarator)
12371 << D.getCXXScopeSpec().getRange();
12372 D.getCXXScopeSpec().clear();
12376 // Ensure we have a valid name
12377 IdentifierInfo *II = nullptr;
12379 II = D.getIdentifier();
12381 Diag(D.getIdentifierLoc(), diag::err_bad_parameter_name)
12382 << GetNameForDeclarator(D).getName();
12383 D.setInvalidType(true);
12387 // Check for redeclaration of parameters, e.g. int foo(int x, int x);
12389 LookupResult R(*this, II, D.getIdentifierLoc(), LookupOrdinaryName,
12390 ForVisibleRedeclaration);
12392 if (R.isSingleResult()) {
12393 NamedDecl *PrevDecl = R.getFoundDecl();
12394 if (PrevDecl->isTemplateParameter()) {
12395 // Maybe we will complain about the shadowed template parameter.
12396 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
12397 // Just pretend that we didn't see the previous declaration.
12398 PrevDecl = nullptr;
12399 } else if (S->isDeclScope(PrevDecl)) {
12400 Diag(D.getIdentifierLoc(), diag::err_param_redefinition) << II;
12401 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
12403 // Recover by removing the name
12405 D.SetIdentifier(nullptr, D.getIdentifierLoc());
12406 D.setInvalidType(true);
12411 // Temporarily put parameter variables in the translation unit, not
12412 // the enclosing context. This prevents them from accidentally
12413 // looking like class members in C++.
12414 ParmVarDecl *New = CheckParameter(Context.getTranslationUnitDecl(),
12416 D.getIdentifierLoc(), II,
12417 parmDeclType, TInfo,
12420 if (D.isInvalidType())
12421 New->setInvalidDecl();
12423 assert(S->isFunctionPrototypeScope());
12424 assert(S->getFunctionPrototypeDepth() >= 1);
12425 New->setScopeInfo(S->getFunctionPrototypeDepth() - 1,
12426 S->getNextFunctionPrototypeIndex());
12428 // Add the parameter declaration into this scope.
12431 IdResolver.AddDecl(New);
12433 ProcessDeclAttributes(S, New, D);
12435 if (D.getDeclSpec().isModulePrivateSpecified())
12436 Diag(New->getLocation(), diag::err_module_private_local)
12437 << 1 << New->getDeclName()
12438 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
12439 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
12441 if (New->hasAttr<BlocksAttr>()) {
12442 Diag(New->getLocation(), diag::err_block_on_nonlocal);
12447 /// Synthesizes a variable for a parameter arising from a
12449 ParmVarDecl *Sema::BuildParmVarDeclForTypedef(DeclContext *DC,
12450 SourceLocation Loc,
12452 /* FIXME: setting StartLoc == Loc.
12453 Would it be worth to modify callers so as to provide proper source
12454 location for the unnamed parameters, embedding the parameter's type? */
12455 ParmVarDecl *Param = ParmVarDecl::Create(Context, DC, Loc, Loc, nullptr,
12456 T, Context.getTrivialTypeSourceInfo(T, Loc),
12458 Param->setImplicit();
12462 void Sema::DiagnoseUnusedParameters(ArrayRef<ParmVarDecl *> Parameters) {
12463 // Don't diagnose unused-parameter errors in template instantiations; we
12464 // will already have done so in the template itself.
12465 if (inTemplateInstantiation())
12468 for (const ParmVarDecl *Parameter : Parameters) {
12469 if (!Parameter->isReferenced() && Parameter->getDeclName() &&
12470 !Parameter->hasAttr<UnusedAttr>()) {
12471 Diag(Parameter->getLocation(), diag::warn_unused_parameter)
12472 << Parameter->getDeclName();
12477 void Sema::DiagnoseSizeOfParametersAndReturnValue(
12478 ArrayRef<ParmVarDecl *> Parameters, QualType ReturnTy, NamedDecl *D) {
12479 if (LangOpts.NumLargeByValueCopy == 0) // No check.
12482 // Warn if the return value is pass-by-value and larger than the specified
12484 if (!ReturnTy->isDependentType() && ReturnTy.isPODType(Context)) {
12485 unsigned Size = Context.getTypeSizeInChars(ReturnTy).getQuantity();
12486 if (Size > LangOpts.NumLargeByValueCopy)
12487 Diag(D->getLocation(), diag::warn_return_value_size)
12488 << D->getDeclName() << Size;
12491 // Warn if any parameter is pass-by-value and larger than the specified
12493 for (const ParmVarDecl *Parameter : Parameters) {
12494 QualType T = Parameter->getType();
12495 if (T->isDependentType() || !T.isPODType(Context))
12497 unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
12498 if (Size > LangOpts.NumLargeByValueCopy)
12499 Diag(Parameter->getLocation(), diag::warn_parameter_size)
12500 << Parameter->getDeclName() << Size;
12504 ParmVarDecl *Sema::CheckParameter(DeclContext *DC, SourceLocation StartLoc,
12505 SourceLocation NameLoc, IdentifierInfo *Name,
12506 QualType T, TypeSourceInfo *TSInfo,
12508 // In ARC, infer a lifetime qualifier for appropriate parameter types.
12509 if (getLangOpts().ObjCAutoRefCount &&
12510 T.getObjCLifetime() == Qualifiers::OCL_None &&
12511 T->isObjCLifetimeType()) {
12513 Qualifiers::ObjCLifetime lifetime;
12515 // Special cases for arrays:
12516 // - if it's const, use __unsafe_unretained
12517 // - otherwise, it's an error
12518 if (T->isArrayType()) {
12519 if (!T.isConstQualified()) {
12520 DelayedDiagnostics.add(
12521 sema::DelayedDiagnostic::makeForbiddenType(
12522 NameLoc, diag::err_arc_array_param_no_ownership, T, false));
12524 lifetime = Qualifiers::OCL_ExplicitNone;
12526 lifetime = T->getObjCARCImplicitLifetime();
12528 T = Context.getLifetimeQualifiedType(T, lifetime);
12531 ParmVarDecl *New = ParmVarDecl::Create(Context, DC, StartLoc, NameLoc, Name,
12532 Context.getAdjustedParameterType(T),
12533 TSInfo, SC, nullptr);
12535 // Parameters can not be abstract class types.
12536 // For record types, this is done by the AbstractClassUsageDiagnoser once
12537 // the class has been completely parsed.
12538 if (!CurContext->isRecord() &&
12539 RequireNonAbstractType(NameLoc, T, diag::err_abstract_type_in_decl,
12540 AbstractParamType))
12541 New->setInvalidDecl();
12543 // Parameter declarators cannot be interface types. All ObjC objects are
12544 // passed by reference.
12545 if (T->isObjCObjectType()) {
12546 SourceLocation TypeEndLoc =
12547 getLocForEndOfToken(TSInfo->getTypeLoc().getLocEnd());
12549 diag::err_object_cannot_be_passed_returned_by_value) << 1 << T
12550 << FixItHint::CreateInsertion(TypeEndLoc, "*");
12551 T = Context.getObjCObjectPointerType(T);
12555 // ISO/IEC TR 18037 S6.7.3: "The type of an object with automatic storage
12556 // duration shall not be qualified by an address-space qualifier."
12557 // Since all parameters have automatic store duration, they can not have
12558 // an address space.
12559 if (T.getAddressSpace() != LangAS::Default &&
12560 // OpenCL allows function arguments declared to be an array of a type
12561 // to be qualified with an address space.
12562 !(getLangOpts().OpenCL &&
12563 (T->isArrayType() || T.getAddressSpace() == LangAS::opencl_private))) {
12564 Diag(NameLoc, diag::err_arg_with_address_space);
12565 New->setInvalidDecl();
12571 void Sema::ActOnFinishKNRParamDeclarations(Scope *S, Declarator &D,
12572 SourceLocation LocAfterDecls) {
12573 DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
12575 // Verify 6.9.1p6: 'every identifier in the identifier list shall be declared'
12576 // for a K&R function.
12577 if (!FTI.hasPrototype) {
12578 for (int i = FTI.NumParams; i != 0; /* decrement in loop */) {
12580 if (FTI.Params[i].Param == nullptr) {
12581 SmallString<256> Code;
12582 llvm::raw_svector_ostream(Code)
12583 << " int " << FTI.Params[i].Ident->getName() << ";\n";
12584 Diag(FTI.Params[i].IdentLoc, diag::ext_param_not_declared)
12585 << FTI.Params[i].Ident
12586 << FixItHint::CreateInsertion(LocAfterDecls, Code);
12588 // Implicitly declare the argument as type 'int' for lack of a better
12590 AttributeFactory attrs;
12591 DeclSpec DS(attrs);
12592 const char* PrevSpec; // unused
12593 unsigned DiagID; // unused
12594 DS.SetTypeSpecType(DeclSpec::TST_int, FTI.Params[i].IdentLoc, PrevSpec,
12595 DiagID, Context.getPrintingPolicy());
12596 // Use the identifier location for the type source range.
12597 DS.SetRangeStart(FTI.Params[i].IdentLoc);
12598 DS.SetRangeEnd(FTI.Params[i].IdentLoc);
12599 Declarator ParamD(DS, DeclaratorContext::KNRTypeListContext);
12600 ParamD.SetIdentifier(FTI.Params[i].Ident, FTI.Params[i].IdentLoc);
12601 FTI.Params[i].Param = ActOnParamDeclarator(S, ParamD);
12608 Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Declarator &D,
12609 MultiTemplateParamsArg TemplateParameterLists,
12610 SkipBodyInfo *SkipBody) {
12611 assert(getCurFunctionDecl() == nullptr && "Function parsing confused");
12612 assert(D.isFunctionDeclarator() && "Not a function declarator!");
12613 Scope *ParentScope = FnBodyScope->getParent();
12615 D.setFunctionDefinitionKind(FDK_Definition);
12616 Decl *DP = HandleDeclarator(ParentScope, D, TemplateParameterLists);
12617 return ActOnStartOfFunctionDef(FnBodyScope, DP, SkipBody);
12620 void Sema::ActOnFinishInlineFunctionDef(FunctionDecl *D) {
12621 Consumer.HandleInlineFunctionDefinition(D);
12624 static bool ShouldWarnAboutMissingPrototype(const FunctionDecl *FD,
12625 const FunctionDecl*& PossibleZeroParamPrototype) {
12626 // Don't warn about invalid declarations.
12627 if (FD->isInvalidDecl())
12630 // Or declarations that aren't global.
12631 if (!FD->isGlobal())
12634 // Don't warn about C++ member functions.
12635 if (isa<CXXMethodDecl>(FD))
12638 // Don't warn about 'main'.
12642 // Don't warn about inline functions.
12643 if (FD->isInlined())
12646 // Don't warn about function templates.
12647 if (FD->getDescribedFunctionTemplate())
12650 // Don't warn about function template specializations.
12651 if (FD->isFunctionTemplateSpecialization())
12654 // Don't warn for OpenCL kernels.
12655 if (FD->hasAttr<OpenCLKernelAttr>())
12658 // Don't warn on explicitly deleted functions.
12659 if (FD->isDeleted())
12662 bool MissingPrototype = true;
12663 for (const FunctionDecl *Prev = FD->getPreviousDecl();
12664 Prev; Prev = Prev->getPreviousDecl()) {
12665 // Ignore any declarations that occur in function or method
12666 // scope, because they aren't visible from the header.
12667 if (Prev->getLexicalDeclContext()->isFunctionOrMethod())
12670 MissingPrototype = !Prev->getType()->isFunctionProtoType();
12671 if (FD->getNumParams() == 0)
12672 PossibleZeroParamPrototype = Prev;
12676 return MissingPrototype;
12680 Sema::CheckForFunctionRedefinition(FunctionDecl *FD,
12681 const FunctionDecl *EffectiveDefinition,
12682 SkipBodyInfo *SkipBody) {
12683 const FunctionDecl *Definition = EffectiveDefinition;
12684 if (!Definition && !FD->isDefined(Definition) && !FD->isCXXClassMember()) {
12685 // If this is a friend function defined in a class template, it does not
12686 // have a body until it is used, nevertheless it is a definition, see
12689 // ... for the purpose of determining whether an instantiated redeclaration
12690 // is valid according to [basic.def.odr] and [class.mem], a declaration that
12691 // corresponds to a definition in the template is considered to be a
12694 // The following code must produce redefinition error:
12696 // template<typename T> struct C20 { friend void func_20() {} };
12698 // void func_20() {}
12700 for (auto I : FD->redecls()) {
12701 if (I != FD && !I->isInvalidDecl() &&
12702 I->getFriendObjectKind() != Decl::FOK_None) {
12703 if (FunctionDecl *Original = I->getInstantiatedFromMemberFunction()) {
12704 if (FunctionDecl *OrigFD = FD->getInstantiatedFromMemberFunction()) {
12705 // A merged copy of the same function, instantiated as a member of
12706 // the same class, is OK.
12707 if (declaresSameEntity(OrigFD, Original) &&
12708 declaresSameEntity(cast<Decl>(I->getLexicalDeclContext()),
12709 cast<Decl>(FD->getLexicalDeclContext())))
12713 if (Original->isThisDeclarationADefinition()) {
12724 if (canRedefineFunction(Definition, getLangOpts()))
12727 // Don't emit an error when this is redefinition of a typo-corrected
12729 if (TypoCorrectedFunctionDefinitions.count(Definition))
12732 // If we don't have a visible definition of the function, and it's inline or
12733 // a template, skip the new definition.
12734 if (SkipBody && !hasVisibleDefinition(Definition) &&
12735 (Definition->getFormalLinkage() == InternalLinkage ||
12736 Definition->isInlined() ||
12737 Definition->getDescribedFunctionTemplate() ||
12738 Definition->getNumTemplateParameterLists())) {
12739 SkipBody->ShouldSkip = true;
12740 if (auto *TD = Definition->getDescribedFunctionTemplate())
12741 makeMergedDefinitionVisible(TD);
12742 makeMergedDefinitionVisible(const_cast<FunctionDecl*>(Definition));
12746 if (getLangOpts().GNUMode && Definition->isInlineSpecified() &&
12747 Definition->getStorageClass() == SC_Extern)
12748 Diag(FD->getLocation(), diag::err_redefinition_extern_inline)
12749 << FD->getDeclName() << getLangOpts().CPlusPlus;
12751 Diag(FD->getLocation(), diag::err_redefinition) << FD->getDeclName();
12753 Diag(Definition->getLocation(), diag::note_previous_definition);
12754 FD->setInvalidDecl();
12757 static void RebuildLambdaScopeInfo(CXXMethodDecl *CallOperator,
12759 CXXRecordDecl *const LambdaClass = CallOperator->getParent();
12761 LambdaScopeInfo *LSI = S.PushLambdaScope();
12762 LSI->CallOperator = CallOperator;
12763 LSI->Lambda = LambdaClass;
12764 LSI->ReturnType = CallOperator->getReturnType();
12765 const LambdaCaptureDefault LCD = LambdaClass->getLambdaCaptureDefault();
12767 if (LCD == LCD_None)
12768 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_None;
12769 else if (LCD == LCD_ByCopy)
12770 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByval;
12771 else if (LCD == LCD_ByRef)
12772 LSI->ImpCaptureStyle = CapturingScopeInfo::ImpCap_LambdaByref;
12773 DeclarationNameInfo DNI = CallOperator->getNameInfo();
12775 LSI->IntroducerRange = DNI.getCXXOperatorNameRange();
12776 LSI->Mutable = !CallOperator->isConst();
12778 // Add the captures to the LSI so they can be noted as already
12779 // captured within tryCaptureVar.
12780 auto I = LambdaClass->field_begin();
12781 for (const auto &C : LambdaClass->captures()) {
12782 if (C.capturesVariable()) {
12783 VarDecl *VD = C.getCapturedVar();
12784 if (VD->isInitCapture())
12785 S.CurrentInstantiationScope->InstantiatedLocal(VD, VD);
12786 QualType CaptureType = VD->getType();
12787 const bool ByRef = C.getCaptureKind() == LCK_ByRef;
12788 LSI->addCapture(VD, /*IsBlock*/false, ByRef,
12789 /*RefersToEnclosingVariableOrCapture*/true, C.getLocation(),
12790 /*EllipsisLoc*/C.isPackExpansion()
12791 ? C.getEllipsisLoc() : SourceLocation(),
12792 CaptureType, /*Expr*/ nullptr);
12794 } else if (C.capturesThis()) {
12795 LSI->addThisCapture(/*Nested*/ false, C.getLocation(),
12797 C.getCaptureKind() == LCK_StarThis);
12799 LSI->addVLATypeCapture(C.getLocation(), I->getType());
12805 Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
12806 SkipBodyInfo *SkipBody) {
12808 // Parsing the function declaration failed in some way. Push on a fake scope
12809 // anyway so we can try to parse the function body.
12810 PushFunctionScope();
12814 FunctionDecl *FD = nullptr;
12816 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(D))
12817 FD = FunTmpl->getTemplatedDecl();
12819 FD = cast<FunctionDecl>(D);
12821 // Check for defining attributes before the check for redefinition.
12822 if (const auto *Attr = FD->getAttr<AliasAttr>()) {
12823 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 0;
12824 FD->dropAttr<AliasAttr>();
12825 FD->setInvalidDecl();
12827 if (const auto *Attr = FD->getAttr<IFuncAttr>()) {
12828 Diag(Attr->getLocation(), diag::err_alias_is_definition) << FD << 1;
12829 FD->dropAttr<IFuncAttr>();
12830 FD->setInvalidDecl();
12833 // See if this is a redefinition. If 'will have body' is already set, then
12834 // these checks were already performed when it was set.
12835 if (!FD->willHaveBody() && !FD->isLateTemplateParsed()) {
12836 CheckForFunctionRedefinition(FD, nullptr, SkipBody);
12838 // If we're skipping the body, we're done. Don't enter the scope.
12839 if (SkipBody && SkipBody->ShouldSkip)
12843 // Mark this function as "will have a body eventually". This lets users to
12844 // call e.g. isInlineDefinitionExternallyVisible while we're still parsing
12846 FD->setWillHaveBody();
12848 // If we are instantiating a generic lambda call operator, push
12849 // a LambdaScopeInfo onto the function stack. But use the information
12850 // that's already been calculated (ActOnLambdaExpr) to prime the current
12851 // LambdaScopeInfo.
12852 // When the template operator is being specialized, the LambdaScopeInfo,
12853 // has to be properly restored so that tryCaptureVariable doesn't try
12854 // and capture any new variables. In addition when calculating potential
12855 // captures during transformation of nested lambdas, it is necessary to
12856 // have the LSI properly restored.
12857 if (isGenericLambdaCallOperatorSpecialization(FD)) {
12858 assert(inTemplateInstantiation() &&
12859 "There should be an active template instantiation on the stack "
12860 "when instantiating a generic lambda!");
12861 RebuildLambdaScopeInfo(cast<CXXMethodDecl>(D), *this);
12863 // Enter a new function scope
12864 PushFunctionScope();
12867 // Builtin functions cannot be defined.
12868 if (unsigned BuiltinID = FD->getBuiltinID()) {
12869 if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID) &&
12870 !Context.BuiltinInfo.isPredefinedRuntimeFunction(BuiltinID)) {
12871 Diag(FD->getLocation(), diag::err_builtin_definition) << FD;
12872 FD->setInvalidDecl();
12876 // The return type of a function definition must be complete
12877 // (C99 6.9.1p3, C++ [dcl.fct]p6).
12878 QualType ResultType = FD->getReturnType();
12879 if (!ResultType->isDependentType() && !ResultType->isVoidType() &&
12880 !FD->isInvalidDecl() &&
12881 RequireCompleteType(FD->getLocation(), ResultType,
12882 diag::err_func_def_incomplete_result))
12883 FD->setInvalidDecl();
12886 PushDeclContext(FnBodyScope, FD);
12888 // Check the validity of our function parameters
12889 CheckParmsForFunctionDef(FD->parameters(),
12890 /*CheckParameterNames=*/true);
12892 // Add non-parameter declarations already in the function to the current
12895 for (Decl *NPD : FD->decls()) {
12896 auto *NonParmDecl = dyn_cast<NamedDecl>(NPD);
12899 assert(!isa<ParmVarDecl>(NonParmDecl) &&
12900 "parameters should not be in newly created FD yet");
12902 // If the decl has a name, make it accessible in the current scope.
12903 if (NonParmDecl->getDeclName())
12904 PushOnScopeChains(NonParmDecl, FnBodyScope, /*AddToContext=*/false);
12906 // Similarly, dive into enums and fish their constants out, making them
12907 // accessible in this scope.
12908 if (auto *ED = dyn_cast<EnumDecl>(NonParmDecl)) {
12909 for (auto *EI : ED->enumerators())
12910 PushOnScopeChains(EI, FnBodyScope, /*AddToContext=*/false);
12915 // Introduce our parameters into the function scope
12916 for (auto Param : FD->parameters()) {
12917 Param->setOwningFunction(FD);
12919 // If this has an identifier, add it to the scope stack.
12920 if (Param->getIdentifier() && FnBodyScope) {
12921 CheckShadow(FnBodyScope, Param);
12923 PushOnScopeChains(Param, FnBodyScope);
12927 // Ensure that the function's exception specification is instantiated.
12928 if (const FunctionProtoType *FPT = FD->getType()->getAs<FunctionProtoType>())
12929 ResolveExceptionSpec(D->getLocation(), FPT);
12931 // dllimport cannot be applied to non-inline function definitions.
12932 if (FD->hasAttr<DLLImportAttr>() && !FD->isInlined() &&
12933 !FD->isTemplateInstantiation()) {
12934 assert(!FD->hasAttr<DLLExportAttr>());
12935 Diag(FD->getLocation(), diag::err_attribute_dllimport_function_definition);
12936 FD->setInvalidDecl();
12939 // We want to attach documentation to original Decl (which might be
12940 // a function template).
12941 ActOnDocumentableDecl(D);
12942 if (getCurLexicalContext()->isObjCContainer() &&
12943 getCurLexicalContext()->getDeclKind() != Decl::ObjCCategoryImpl &&
12944 getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
12945 Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
12950 /// Given the set of return statements within a function body,
12951 /// compute the variables that are subject to the named return value
12954 /// Each of the variables that is subject to the named return value
12955 /// optimization will be marked as NRVO variables in the AST, and any
12956 /// return statement that has a marked NRVO variable as its NRVO candidate can
12957 /// use the named return value optimization.
12959 /// This function applies a very simplistic algorithm for NRVO: if every return
12960 /// statement in the scope of a variable has the same NRVO candidate, that
12961 /// candidate is an NRVO variable.
12962 void Sema::computeNRVO(Stmt *Body, FunctionScopeInfo *Scope) {
12963 ReturnStmt **Returns = Scope->Returns.data();
12965 for (unsigned I = 0, E = Scope->Returns.size(); I != E; ++I) {
12966 if (const VarDecl *NRVOCandidate = Returns[I]->getNRVOCandidate()) {
12967 if (!NRVOCandidate->isNRVOVariable())
12968 Returns[I]->setNRVOCandidate(nullptr);
12973 bool Sema::canDelayFunctionBody(const Declarator &D) {
12974 // We can't delay parsing the body of a constexpr function template (yet).
12975 if (D.getDeclSpec().isConstexprSpecified())
12978 // We can't delay parsing the body of a function template with a deduced
12979 // return type (yet).
12980 if (D.getDeclSpec().hasAutoTypeSpec()) {
12981 // If the placeholder introduces a non-deduced trailing return type,
12982 // we can still delay parsing it.
12983 if (D.getNumTypeObjects()) {
12984 const auto &Outer = D.getTypeObject(D.getNumTypeObjects() - 1);
12985 if (Outer.Kind == DeclaratorChunk::Function &&
12986 Outer.Fun.hasTrailingReturnType()) {
12987 QualType Ty = GetTypeFromParser(Outer.Fun.getTrailingReturnType());
12988 return Ty.isNull() || !Ty->isUndeducedType();
12997 bool Sema::canSkipFunctionBody(Decl *D) {
12998 // We cannot skip the body of a function (or function template) which is
12999 // constexpr, since we may need to evaluate its body in order to parse the
13000 // rest of the file.
13001 // We cannot skip the body of a function with an undeduced return type,
13002 // because any callers of that function need to know the type.
13003 if (const FunctionDecl *FD = D->getAsFunction()) {
13004 if (FD->isConstexpr())
13006 // We can't simply call Type::isUndeducedType here, because inside template
13007 // auto can be deduced to a dependent type, which is not considered
13009 if (FD->getReturnType()->getContainedDeducedType())
13012 return Consumer.shouldSkipFunctionBody(D);
13015 Decl *Sema::ActOnSkippedFunctionBody(Decl *Decl) {
13018 if (FunctionDecl *FD = Decl->getAsFunction())
13019 FD->setHasSkippedBody();
13020 else if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Decl))
13021 MD->setHasSkippedBody();
13025 Decl *Sema::ActOnFinishFunctionBody(Decl *D, Stmt *BodyArg) {
13026 return ActOnFinishFunctionBody(D, BodyArg, false);
13029 Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt *Body,
13030 bool IsInstantiation) {
13031 FunctionDecl *FD = dcl ? dcl->getAsFunction() : nullptr;
13033 sema::AnalysisBasedWarnings::Policy WP = AnalysisWarnings.getDefaultPolicy();
13034 sema::AnalysisBasedWarnings::Policy *ActivePolicy = nullptr;
13036 if (getLangOpts().CoroutinesTS && getCurFunction()->isCoroutine())
13037 CheckCompletedCoroutineBody(FD, Body);
13041 FD->setWillHaveBody(false);
13043 if (getLangOpts().CPlusPlus14) {
13044 if (!FD->isInvalidDecl() && Body && !FD->isDependentContext() &&
13045 FD->getReturnType()->isUndeducedType()) {
13046 // If the function has a deduced result type but contains no 'return'
13047 // statements, the result type as written must be exactly 'auto', and
13048 // the deduced result type is 'void'.
13049 if (!FD->getReturnType()->getAs<AutoType>()) {
13050 Diag(dcl->getLocation(), diag::err_auto_fn_no_return_but_not_auto)
13051 << FD->getReturnType();
13052 FD->setInvalidDecl();
13054 // Substitute 'void' for the 'auto' in the type.
13055 TypeLoc ResultType = getReturnTypeLoc(FD);
13056 Context.adjustDeducedFunctionResultType(
13057 FD, SubstAutoType(ResultType.getType(), Context.VoidTy));
13060 } else if (getLangOpts().CPlusPlus11 && isLambdaCallOperator(FD)) {
13061 // In C++11, we don't use 'auto' deduction rules for lambda call
13062 // operators because we don't support return type deduction.
13063 auto *LSI = getCurLambda();
13064 if (LSI->HasImplicitReturnType) {
13065 deduceClosureReturnType(*LSI);
13067 // C++11 [expr.prim.lambda]p4:
13068 // [...] if there are no return statements in the compound-statement
13069 // [the deduced type is] the type void
13071 LSI->ReturnType.isNull() ? Context.VoidTy : LSI->ReturnType;
13073 // Update the return type to the deduced type.
13074 const FunctionProtoType *Proto =
13075 FD->getType()->getAs<FunctionProtoType>();
13076 FD->setType(Context.getFunctionType(RetType, Proto->getParamTypes(),
13077 Proto->getExtProtoInfo()));
13081 // If the function implicitly returns zero (like 'main') or is naked,
13082 // don't complain about missing return statements.
13083 if (FD->hasImplicitReturnZero() || FD->hasAttr<NakedAttr>())
13084 WP.disableCheckFallThrough();
13086 // MSVC permits the use of pure specifier (=0) on function definition,
13087 // defined at class scope, warn about this non-standard construct.
13088 if (getLangOpts().MicrosoftExt && FD->isPure() && FD->isCanonicalDecl())
13089 Diag(FD->getLocation(), diag::ext_pure_function_definition);
13091 if (!FD->isInvalidDecl()) {
13092 // Don't diagnose unused parameters of defaulted or deleted functions.
13093 if (!FD->isDeleted() && !FD->isDefaulted())
13094 DiagnoseUnusedParameters(FD->parameters());
13095 DiagnoseSizeOfParametersAndReturnValue(FD->parameters(),
13096 FD->getReturnType(), FD);
13098 // If this is a structor, we need a vtable.
13099 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(FD))
13100 MarkVTableUsed(FD->getLocation(), Constructor->getParent());
13101 else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(FD))
13102 MarkVTableUsed(FD->getLocation(), Destructor->getParent());
13104 // Try to apply the named return value optimization. We have to check
13105 // if we can do this here because lambdas keep return statements around
13106 // to deduce an implicit return type.
13107 if (FD->getReturnType()->isRecordType() &&
13108 (!getLangOpts().CPlusPlus || !FD->isDependentContext()))
13109 computeNRVO(Body, getCurFunction());
13112 // GNU warning -Wmissing-prototypes:
13113 // Warn if a global function is defined without a previous
13114 // prototype declaration. This warning is issued even if the
13115 // definition itself provides a prototype. The aim is to detect
13116 // global functions that fail to be declared in header files.
13117 const FunctionDecl *PossibleZeroParamPrototype = nullptr;
13118 if (ShouldWarnAboutMissingPrototype(FD, PossibleZeroParamPrototype)) {
13119 Diag(FD->getLocation(), diag::warn_missing_prototype) << FD;
13121 if (PossibleZeroParamPrototype) {
13122 // We found a declaration that is not a prototype,
13123 // but that could be a zero-parameter prototype
13124 if (TypeSourceInfo *TI =
13125 PossibleZeroParamPrototype->getTypeSourceInfo()) {
13126 TypeLoc TL = TI->getTypeLoc();
13127 if (FunctionNoProtoTypeLoc FTL = TL.getAs<FunctionNoProtoTypeLoc>())
13128 Diag(PossibleZeroParamPrototype->getLocation(),
13129 diag::note_declaration_not_a_prototype)
13130 << PossibleZeroParamPrototype
13131 << FixItHint::CreateInsertion(FTL.getRParenLoc(), "void");
13135 // GNU warning -Wstrict-prototypes
13136 // Warn if K&R function is defined without a previous declaration.
13137 // This warning is issued only if the definition itself does not provide
13138 // a prototype. Only K&R definitions do not provide a prototype.
13139 // An empty list in a function declarator that is part of a definition
13140 // of that function specifies that the function has no parameters
13141 // (C99 6.7.5.3p14)
13142 if (!FD->hasWrittenPrototype() && FD->getNumParams() > 0 &&
13143 !LangOpts.CPlusPlus) {
13144 TypeSourceInfo *TI = FD->getTypeSourceInfo();
13145 TypeLoc TL = TI->getTypeLoc();
13146 FunctionTypeLoc FTL = TL.getAsAdjusted<FunctionTypeLoc>();
13147 Diag(FTL.getLParenLoc(), diag::warn_strict_prototypes) << 2;
13151 // Warn on CPUDispatch with an actual body.
13152 if (FD->isMultiVersion() && FD->hasAttr<CPUDispatchAttr>() && Body)
13153 if (const auto *CmpndBody = dyn_cast<CompoundStmt>(Body))
13154 if (!CmpndBody->body_empty())
13155 Diag(CmpndBody->body_front()->getLocStart(),
13156 diag::warn_dispatch_body_ignored);
13158 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
13159 const CXXMethodDecl *KeyFunction;
13160 if (MD->isOutOfLine() && (MD = MD->getCanonicalDecl()) &&
13162 (KeyFunction = Context.getCurrentKeyFunction(MD->getParent())) &&
13163 MD == KeyFunction->getCanonicalDecl()) {
13164 // Update the key-function state if necessary for this ABI.
13165 if (FD->isInlined() &&
13166 !Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline()) {
13167 Context.setNonKeyFunction(MD);
13169 // If the newly-chosen key function is already defined, then we
13170 // need to mark the vtable as used retroactively.
13171 KeyFunction = Context.getCurrentKeyFunction(MD->getParent());
13172 const FunctionDecl *Definition;
13173 if (KeyFunction && KeyFunction->isDefined(Definition))
13174 MarkVTableUsed(Definition->getLocation(), MD->getParent(), true);
13176 // We just defined they key function; mark the vtable as used.
13177 MarkVTableUsed(FD->getLocation(), MD->getParent(), true);
13182 assert((FD == getCurFunctionDecl() || getCurLambda()->CallOperator == FD) &&
13183 "Function parsing confused");
13184 } else if (ObjCMethodDecl *MD = dyn_cast_or_null<ObjCMethodDecl>(dcl)) {
13185 assert(MD == getCurMethodDecl() && "Method parsing confused");
13187 if (!MD->isInvalidDecl()) {
13188 DiagnoseUnusedParameters(MD->parameters());
13189 DiagnoseSizeOfParametersAndReturnValue(MD->parameters(),
13190 MD->getReturnType(), MD);
13193 computeNRVO(Body, getCurFunction());
13195 if (getCurFunction()->ObjCShouldCallSuper) {
13196 Diag(MD->getLocEnd(), diag::warn_objc_missing_super_call)
13197 << MD->getSelector().getAsString();
13198 getCurFunction()->ObjCShouldCallSuper = false;
13200 if (getCurFunction()->ObjCWarnForNoDesignatedInitChain) {
13201 const ObjCMethodDecl *InitMethod = nullptr;
13202 bool isDesignated =
13203 MD->isDesignatedInitializerForTheInterface(&InitMethod);
13204 assert(isDesignated && InitMethod);
13205 (void)isDesignated;
13207 auto superIsNSObject = [&](const ObjCMethodDecl *MD) {
13208 auto IFace = MD->getClassInterface();
13211 auto SuperD = IFace->getSuperClass();
13214 return SuperD->getIdentifier() ==
13215 NSAPIObj->getNSClassId(NSAPI::ClassId_NSObject);
13217 // Don't issue this warning for unavailable inits or direct subclasses
13219 if (!MD->isUnavailable() && !superIsNSObject(MD)) {
13220 Diag(MD->getLocation(),
13221 diag::warn_objc_designated_init_missing_super_call);
13222 Diag(InitMethod->getLocation(),
13223 diag::note_objc_designated_init_marked_here);
13225 getCurFunction()->ObjCWarnForNoDesignatedInitChain = false;
13227 if (getCurFunction()->ObjCWarnForNoInitDelegation) {
13228 // Don't issue this warning for unavaialable inits.
13229 if (!MD->isUnavailable())
13230 Diag(MD->getLocation(),
13231 diag::warn_objc_secondary_init_missing_init_call);
13232 getCurFunction()->ObjCWarnForNoInitDelegation = false;
13235 // Parsing the function declaration failed in some way. Pop the fake scope
13237 PopFunctionScopeInfo(ActivePolicy, dcl);
13241 if (Body && getCurFunction()->HasPotentialAvailabilityViolations)
13242 DiagnoseUnguardedAvailabilityViolations(dcl);
13244 assert(!getCurFunction()->ObjCShouldCallSuper &&
13245 "This should only be set for ObjC methods, which should have been "
13246 "handled in the block above.");
13248 // Verify and clean out per-function state.
13249 if (Body && (!FD || !FD->isDefaulted())) {
13250 // C++ constructors that have function-try-blocks can't have return
13251 // statements in the handlers of that block. (C++ [except.handle]p14)
13253 if (FD && isa<CXXConstructorDecl>(FD) && isa<CXXTryStmt>(Body))
13254 DiagnoseReturnInConstructorExceptionHandler(cast<CXXTryStmt>(Body));
13256 // Verify that gotos and switch cases don't jump into scopes illegally.
13257 if (getCurFunction()->NeedsScopeChecking() &&
13258 !PP.isCodeCompletionEnabled())
13259 DiagnoseInvalidJumps(Body);
13261 if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(dcl)) {
13262 if (!Destructor->getParent()->isDependentType())
13263 CheckDestructor(Destructor);
13265 MarkBaseAndMemberDestructorsReferenced(Destructor->getLocation(),
13266 Destructor->getParent());
13269 // If any errors have occurred, clear out any temporaries that may have
13270 // been leftover. This ensures that these temporaries won't be picked up for
13271 // deletion in some later function.
13272 if (getDiagnostics().hasErrorOccurred() ||
13273 getDiagnostics().getSuppressAllDiagnostics()) {
13274 DiscardCleanupsInEvaluationContext();
13276 if (!getDiagnostics().hasUncompilableErrorOccurred() &&
13277 !isa<FunctionTemplateDecl>(dcl)) {
13278 // Since the body is valid, issue any analysis-based warnings that are
13280 ActivePolicy = &WP;
13283 if (!IsInstantiation && FD && FD->isConstexpr() && !FD->isInvalidDecl() &&
13284 (!CheckConstexprFunctionDecl(FD) ||
13285 !CheckConstexprFunctionBody(FD, Body)))
13286 FD->setInvalidDecl();
13288 if (FD && FD->hasAttr<NakedAttr>()) {
13289 for (const Stmt *S : Body->children()) {
13290 // Allow local register variables without initializer as they don't
13291 // require prologue.
13292 bool RegisterVariables = false;
13293 if (auto *DS = dyn_cast<DeclStmt>(S)) {
13294 for (const auto *Decl : DS->decls()) {
13295 if (const auto *Var = dyn_cast<VarDecl>(Decl)) {
13296 RegisterVariables =
13297 Var->hasAttr<AsmLabelAttr>() && !Var->hasInit();
13298 if (!RegisterVariables)
13303 if (RegisterVariables)
13305 if (!isa<AsmStmt>(S) && !isa<NullStmt>(S)) {
13306 Diag(S->getLocStart(), diag::err_non_asm_stmt_in_naked_function);
13307 Diag(FD->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
13308 FD->setInvalidDecl();
13314 assert(ExprCleanupObjects.size() ==
13315 ExprEvalContexts.back().NumCleanupObjects &&
13316 "Leftover temporaries in function");
13317 assert(!Cleanup.exprNeedsCleanups() && "Unaccounted cleanups in function");
13318 assert(MaybeODRUseExprs.empty() &&
13319 "Leftover expressions for odr-use checking");
13322 if (!IsInstantiation)
13325 PopFunctionScopeInfo(ActivePolicy, dcl);
13326 // If any errors have occurred, clear out any temporaries that may have
13327 // been leftover. This ensures that these temporaries won't be picked up for
13328 // deletion in some later function.
13329 if (getDiagnostics().hasErrorOccurred()) {
13330 DiscardCleanupsInEvaluationContext();
13336 /// When we finish delayed parsing of an attribute, we must attach it to the
13338 void Sema::ActOnFinishDelayedAttribute(Scope *S, Decl *D,
13339 ParsedAttributes &Attrs) {
13340 // Always attach attributes to the underlying decl.
13341 if (TemplateDecl *TD = dyn_cast<TemplateDecl>(D))
13342 D = TD->getTemplatedDecl();
13343 ProcessDeclAttributeList(S, D, Attrs);
13345 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(D))
13346 if (Method->isStatic())
13347 checkThisInStaticMemberFunctionAttributes(Method);
13350 /// ImplicitlyDefineFunction - An undeclared identifier was used in a function
13351 /// call, forming a call to an implicitly defined function (per C99 6.5.1p2).
13352 NamedDecl *Sema::ImplicitlyDefineFunction(SourceLocation Loc,
13353 IdentifierInfo &II, Scope *S) {
13354 // Find the scope in which the identifier is injected and the corresponding
13356 // FIXME: C89 does not say what happens if there is no enclosing block scope.
13357 // In that case, we inject the declaration into the translation unit scope
13359 Scope *BlockScope = S;
13360 while (!BlockScope->isCompoundStmtScope() && BlockScope->getParent())
13361 BlockScope = BlockScope->getParent();
13363 Scope *ContextScope = BlockScope;
13364 while (!ContextScope->getEntity())
13365 ContextScope = ContextScope->getParent();
13366 ContextRAII SavedContext(*this, ContextScope->getEntity());
13368 // Before we produce a declaration for an implicitly defined
13369 // function, see whether there was a locally-scoped declaration of
13370 // this name as a function or variable. If so, use that
13371 // (non-visible) declaration, and complain about it.
13372 NamedDecl *ExternCPrev = findLocallyScopedExternCDecl(&II);
13374 // We still need to inject the function into the enclosing block scope so
13375 // that later (non-call) uses can see it.
13376 PushOnScopeChains(ExternCPrev, BlockScope, /*AddToContext*/false);
13378 // C89 footnote 38:
13379 // If in fact it is not defined as having type "function returning int",
13380 // the behavior is undefined.
13381 if (!isa<FunctionDecl>(ExternCPrev) ||
13382 !Context.typesAreCompatible(
13383 cast<FunctionDecl>(ExternCPrev)->getType(),
13384 Context.getFunctionNoProtoType(Context.IntTy))) {
13385 Diag(Loc, diag::ext_use_out_of_scope_declaration)
13386 << ExternCPrev << !getLangOpts().C99;
13387 Diag(ExternCPrev->getLocation(), diag::note_previous_declaration);
13388 return ExternCPrev;
13392 // Extension in C99. Legal in C90, but warn about it.
13393 // OpenCL v2.0 s6.9.u - Implicit function declaration is not supported.
13395 if (II.getName().startswith("__builtin_"))
13396 diag_id = diag::warn_builtin_unknown;
13397 else if (getLangOpts().C99 || getLangOpts().OpenCL)
13398 diag_id = diag::ext_implicit_function_decl;
13400 diag_id = diag::warn_implicit_function_decl;
13401 Diag(Loc, diag_id) << &II << getLangOpts().OpenCL;
13403 // If we found a prior declaration of this function, don't bother building
13404 // another one. We've already pushed that one into scope, so there's nothing
13407 return ExternCPrev;
13409 // Because typo correction is expensive, only do it if the implicit
13410 // function declaration is going to be treated as an error.
13411 if (Diags.getDiagnosticLevel(diag_id, Loc) >= DiagnosticsEngine::Error) {
13412 TypoCorrection Corrected;
13414 (Corrected = CorrectTypo(
13415 DeclarationNameInfo(&II, Loc), LookupOrdinaryName, S, nullptr,
13416 llvm::make_unique<DeclFilterCCC<FunctionDecl>>(), CTK_NonError)))
13417 diagnoseTypo(Corrected, PDiag(diag::note_function_suggestion),
13418 /*ErrorRecovery*/false);
13421 // Set a Declarator for the implicit definition: int foo();
13423 AttributeFactory attrFactory;
13424 DeclSpec DS(attrFactory);
13426 bool Error = DS.SetTypeSpecType(DeclSpec::TST_int, Loc, Dummy, DiagID,
13427 Context.getPrintingPolicy());
13428 (void)Error; // Silence warning.
13429 assert(!Error && "Error setting up implicit decl!");
13430 SourceLocation NoLoc;
13431 Declarator D(DS, DeclaratorContext::BlockContext);
13432 D.AddTypeInfo(DeclaratorChunk::getFunction(/*HasProto=*/false,
13433 /*IsAmbiguous=*/false,
13434 /*LParenLoc=*/NoLoc,
13435 /*Params=*/nullptr,
13437 /*EllipsisLoc=*/NoLoc,
13438 /*RParenLoc=*/NoLoc,
13440 /*RefQualifierIsLvalueRef=*/true,
13441 /*RefQualifierLoc=*/NoLoc,
13442 /*ConstQualifierLoc=*/NoLoc,
13443 /*VolatileQualifierLoc=*/NoLoc,
13444 /*RestrictQualifierLoc=*/NoLoc,
13445 /*MutableLoc=*/NoLoc, EST_None,
13446 /*ESpecRange=*/SourceRange(),
13447 /*Exceptions=*/nullptr,
13448 /*ExceptionRanges=*/nullptr,
13449 /*NumExceptions=*/0,
13450 /*NoexceptExpr=*/nullptr,
13451 /*ExceptionSpecTokens=*/nullptr,
13452 /*DeclsInPrototype=*/None, Loc,
13454 std::move(DS.getAttributes()), SourceLocation());
13455 D.SetIdentifier(&II, Loc);
13457 // Insert this function into the enclosing block scope.
13458 FunctionDecl *FD = cast<FunctionDecl>(ActOnDeclarator(BlockScope, D));
13461 AddKnownFunctionAttributes(FD);
13466 /// Adds any function attributes that we know a priori based on
13467 /// the declaration of this function.
13469 /// These attributes can apply both to implicitly-declared builtins
13470 /// (like __builtin___printf_chk) or to library-declared functions
13471 /// like NSLog or printf.
13473 /// We need to check for duplicate attributes both here and where user-written
13474 /// attributes are applied to declarations.
13475 void Sema::AddKnownFunctionAttributes(FunctionDecl *FD) {
13476 if (FD->isInvalidDecl())
13479 // If this is a built-in function, map its builtin attributes to
13480 // actual attributes.
13481 if (unsigned BuiltinID = FD->getBuiltinID()) {
13482 // Handle printf-formatting attributes.
13483 unsigned FormatIdx;
13485 if (Context.BuiltinInfo.isPrintfLike(BuiltinID, FormatIdx, HasVAListArg)) {
13486 if (!FD->hasAttr<FormatAttr>()) {
13487 const char *fmt = "printf";
13488 unsigned int NumParams = FD->getNumParams();
13489 if (FormatIdx < NumParams && // NumParams may be 0 (e.g. vfprintf)
13490 FD->getParamDecl(FormatIdx)->getType()->isObjCObjectPointerType())
13492 FD->addAttr(FormatAttr::CreateImplicit(Context,
13493 &Context.Idents.get(fmt),
13495 HasVAListArg ? 0 : FormatIdx+2,
13496 FD->getLocation()));
13499 if (Context.BuiltinInfo.isScanfLike(BuiltinID, FormatIdx,
13501 if (!FD->hasAttr<FormatAttr>())
13502 FD->addAttr(FormatAttr::CreateImplicit(Context,
13503 &Context.Idents.get("scanf"),
13505 HasVAListArg ? 0 : FormatIdx+2,
13506 FD->getLocation()));
13509 // Mark const if we don't care about errno and that is the only thing
13510 // preventing the function from being const. This allows IRgen to use LLVM
13511 // intrinsics for such functions.
13512 if (!getLangOpts().MathErrno && !FD->hasAttr<ConstAttr>() &&
13513 Context.BuiltinInfo.isConstWithoutErrno(BuiltinID))
13514 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13516 // We make "fma" on some platforms const because we know it does not set
13517 // errno in those environments even though it could set errno based on the
13519 const llvm::Triple &Trip = Context.getTargetInfo().getTriple();
13520 if ((Trip.isGNUEnvironment() || Trip.isAndroid() || Trip.isOSMSVCRT()) &&
13521 !FD->hasAttr<ConstAttr>()) {
13522 switch (BuiltinID) {
13523 case Builtin::BI__builtin_fma:
13524 case Builtin::BI__builtin_fmaf:
13525 case Builtin::BI__builtin_fmal:
13526 case Builtin::BIfma:
13527 case Builtin::BIfmaf:
13528 case Builtin::BIfmal:
13529 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13536 if (Context.BuiltinInfo.isReturnsTwice(BuiltinID) &&
13537 !FD->hasAttr<ReturnsTwiceAttr>())
13538 FD->addAttr(ReturnsTwiceAttr::CreateImplicit(Context,
13539 FD->getLocation()));
13540 if (Context.BuiltinInfo.isNoThrow(BuiltinID) && !FD->hasAttr<NoThrowAttr>())
13541 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
13542 if (Context.BuiltinInfo.isPure(BuiltinID) && !FD->hasAttr<PureAttr>())
13543 FD->addAttr(PureAttr::CreateImplicit(Context, FD->getLocation()));
13544 if (Context.BuiltinInfo.isConst(BuiltinID) && !FD->hasAttr<ConstAttr>())
13545 FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
13546 if (getLangOpts().CUDA && Context.BuiltinInfo.isTSBuiltin(BuiltinID) &&
13547 !FD->hasAttr<CUDADeviceAttr>() && !FD->hasAttr<CUDAHostAttr>()) {
13548 // Add the appropriate attribute, depending on the CUDA compilation mode
13549 // and which target the builtin belongs to. For example, during host
13550 // compilation, aux builtins are __device__, while the rest are __host__.
13551 if (getLangOpts().CUDAIsDevice !=
13552 Context.BuiltinInfo.isAuxBuiltinID(BuiltinID))
13553 FD->addAttr(CUDADeviceAttr::CreateImplicit(Context, FD->getLocation()));
13555 FD->addAttr(CUDAHostAttr::CreateImplicit(Context, FD->getLocation()));
13559 // If C++ exceptions are enabled but we are told extern "C" functions cannot
13560 // throw, add an implicit nothrow attribute to any extern "C" function we come
13562 if (getLangOpts().CXXExceptions && getLangOpts().ExternCNoUnwind &&
13563 FD->isExternC() && !FD->hasAttr<NoThrowAttr>()) {
13564 const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
13565 if (!FPT || FPT->getExceptionSpecType() == EST_None)
13566 FD->addAttr(NoThrowAttr::CreateImplicit(Context, FD->getLocation()));
13569 IdentifierInfo *Name = FD->getIdentifier();
13572 if ((!getLangOpts().CPlusPlus &&
13573 FD->getDeclContext()->isTranslationUnit()) ||
13574 (isa<LinkageSpecDecl>(FD->getDeclContext()) &&
13575 cast<LinkageSpecDecl>(FD->getDeclContext())->getLanguage() ==
13576 LinkageSpecDecl::lang_c)) {
13577 // Okay: this could be a libc/libm/Objective-C function we know
13582 if (Name->isStr("asprintf") || Name->isStr("vasprintf")) {
13583 // FIXME: asprintf and vasprintf aren't C99 functions. Should they be
13584 // target-specific builtins, perhaps?
13585 if (!FD->hasAttr<FormatAttr>())
13586 FD->addAttr(FormatAttr::CreateImplicit(Context,
13587 &Context.Idents.get("printf"), 2,
13588 Name->isStr("vasprintf") ? 0 : 3,
13589 FD->getLocation()));
13592 if (Name->isStr("__CFStringMakeConstantString")) {
13593 // We already have a __builtin___CFStringMakeConstantString,
13594 // but builds that use -fno-constant-cfstrings don't go through that.
13595 if (!FD->hasAttr<FormatArgAttr>())
13596 FD->addAttr(FormatArgAttr::CreateImplicit(Context, ParamIdx(1, FD),
13597 FD->getLocation()));
13601 TypedefDecl *Sema::ParseTypedefDecl(Scope *S, Declarator &D, QualType T,
13602 TypeSourceInfo *TInfo) {
13603 assert(D.getIdentifier() && "Wrong callback for declspec without declarator");
13604 assert(!T.isNull() && "GetTypeForDeclarator() returned null type");
13607 assert(D.isInvalidType() && "no declarator info for valid type");
13608 TInfo = Context.getTrivialTypeSourceInfo(T);
13611 // Scope manipulation handled by caller.
13612 TypedefDecl *NewTD = TypedefDecl::Create(Context, CurContext,
13614 D.getIdentifierLoc(),
13618 // Bail out immediately if we have an invalid declaration.
13619 if (D.isInvalidType()) {
13620 NewTD->setInvalidDecl();
13624 if (D.getDeclSpec().isModulePrivateSpecified()) {
13625 if (CurContext->isFunctionOrMethod())
13626 Diag(NewTD->getLocation(), diag::err_module_private_local)
13627 << 2 << NewTD->getDeclName()
13628 << SourceRange(D.getDeclSpec().getModulePrivateSpecLoc())
13629 << FixItHint::CreateRemoval(D.getDeclSpec().getModulePrivateSpecLoc());
13631 NewTD->setModulePrivate();
13634 // C++ [dcl.typedef]p8:
13635 // If the typedef declaration defines an unnamed class (or
13636 // enum), the first typedef-name declared by the declaration
13637 // to be that class type (or enum type) is used to denote the
13638 // class type (or enum type) for linkage purposes only.
13639 // We need to check whether the type was declared in the declaration.
13640 switch (D.getDeclSpec().getTypeSpecType()) {
13643 case TST_interface:
13646 TagDecl *tagFromDeclSpec = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
13647 setTagNameForLinkagePurposes(tagFromDeclSpec, NewTD);
13658 /// Check that this is a valid underlying type for an enum declaration.
13659 bool Sema::CheckEnumUnderlyingType(TypeSourceInfo *TI) {
13660 SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
13661 QualType T = TI->getType();
13663 if (T->isDependentType())
13666 if (const BuiltinType *BT = T->getAs<BuiltinType>())
13667 if (BT->isInteger())
13670 Diag(UnderlyingLoc, diag::err_enum_invalid_underlying) << T;
13674 /// Check whether this is a valid redeclaration of a previous enumeration.
13675 /// \return true if the redeclaration was invalid.
13676 bool Sema::CheckEnumRedeclaration(SourceLocation EnumLoc, bool IsScoped,
13677 QualType EnumUnderlyingTy, bool IsFixed,
13678 const EnumDecl *Prev) {
13679 if (IsScoped != Prev->isScoped()) {
13680 Diag(EnumLoc, diag::err_enum_redeclare_scoped_mismatch)
13681 << Prev->isScoped();
13682 Diag(Prev->getLocation(), diag::note_previous_declaration);
13686 if (IsFixed && Prev->isFixed()) {
13687 if (!EnumUnderlyingTy->isDependentType() &&
13688 !Prev->getIntegerType()->isDependentType() &&
13689 !Context.hasSameUnqualifiedType(EnumUnderlyingTy,
13690 Prev->getIntegerType())) {
13691 // TODO: Highlight the underlying type of the redeclaration.
13692 Diag(EnumLoc, diag::err_enum_redeclare_type_mismatch)
13693 << EnumUnderlyingTy << Prev->getIntegerType();
13694 Diag(Prev->getLocation(), diag::note_previous_declaration)
13695 << Prev->getIntegerTypeRange();
13698 } else if (IsFixed != Prev->isFixed()) {
13699 Diag(EnumLoc, diag::err_enum_redeclare_fixed_mismatch)
13700 << Prev->isFixed();
13701 Diag(Prev->getLocation(), diag::note_previous_declaration);
13708 /// Get diagnostic %select index for tag kind for
13709 /// redeclaration diagnostic message.
13710 /// WARNING: Indexes apply to particular diagnostics only!
13712 /// \returns diagnostic %select index.
13713 static unsigned getRedeclDiagFromTagKind(TagTypeKind Tag) {
13715 case TTK_Struct: return 0;
13716 case TTK_Interface: return 1;
13717 case TTK_Class: return 2;
13718 default: llvm_unreachable("Invalid tag kind for redecl diagnostic!");
13722 /// Determine if tag kind is a class-key compatible with
13723 /// class for redeclaration (class, struct, or __interface).
13725 /// \returns true iff the tag kind is compatible.
13726 static bool isClassCompatTagKind(TagTypeKind Tag)
13728 return Tag == TTK_Struct || Tag == TTK_Class || Tag == TTK_Interface;
13731 Sema::NonTagKind Sema::getNonTagTypeDeclKind(const Decl *PrevDecl,
13733 if (isa<TypedefDecl>(PrevDecl))
13734 return NTK_Typedef;
13735 else if (isa<TypeAliasDecl>(PrevDecl))
13736 return NTK_TypeAlias;
13737 else if (isa<ClassTemplateDecl>(PrevDecl))
13738 return NTK_Template;
13739 else if (isa<TypeAliasTemplateDecl>(PrevDecl))
13740 return NTK_TypeAliasTemplate;
13741 else if (isa<TemplateTemplateParmDecl>(PrevDecl))
13742 return NTK_TemplateTemplateArgument;
13745 case TTK_Interface:
13747 return getLangOpts().CPlusPlus ? NTK_NonClass : NTK_NonStruct;
13749 return NTK_NonUnion;
13751 return NTK_NonEnum;
13753 llvm_unreachable("invalid TTK");
13756 /// Determine whether a tag with a given kind is acceptable
13757 /// as a redeclaration of the given tag declaration.
13759 /// \returns true if the new tag kind is acceptable, false otherwise.
13760 bool Sema::isAcceptableTagRedeclaration(const TagDecl *Previous,
13761 TagTypeKind NewTag, bool isDefinition,
13762 SourceLocation NewTagLoc,
13763 const IdentifierInfo *Name) {
13764 // C++ [dcl.type.elab]p3:
13765 // The class-key or enum keyword present in the
13766 // elaborated-type-specifier shall agree in kind with the
13767 // declaration to which the name in the elaborated-type-specifier
13768 // refers. This rule also applies to the form of
13769 // elaborated-type-specifier that declares a class-name or
13770 // friend class since it can be construed as referring to the
13771 // definition of the class. Thus, in any
13772 // elaborated-type-specifier, the enum keyword shall be used to
13773 // refer to an enumeration (7.2), the union class-key shall be
13774 // used to refer to a union (clause 9), and either the class or
13775 // struct class-key shall be used to refer to a class (clause 9)
13776 // declared using the class or struct class-key.
13777 TagTypeKind OldTag = Previous->getTagKind();
13778 if (!isDefinition || !isClassCompatTagKind(NewTag))
13779 if (OldTag == NewTag)
13782 if (isClassCompatTagKind(OldTag) && isClassCompatTagKind(NewTag)) {
13783 // Warn about the struct/class tag mismatch.
13784 bool isTemplate = false;
13785 if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Previous))
13786 isTemplate = Record->getDescribedClassTemplate();
13788 if (inTemplateInstantiation()) {
13789 // In a template instantiation, do not offer fix-its for tag mismatches
13790 // since they usually mess up the template instead of fixing the problem.
13791 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
13792 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13793 << getRedeclDiagFromTagKind(OldTag);
13797 if (isDefinition) {
13798 // On definitions, check previous tags and issue a fix-it for each
13799 // one that doesn't match the current tag.
13800 if (Previous->getDefinition()) {
13801 // Don't suggest fix-its for redefinitions.
13805 bool previousMismatch = false;
13806 for (auto I : Previous->redecls()) {
13807 if (I->getTagKind() != NewTag) {
13808 if (!previousMismatch) {
13809 previousMismatch = true;
13810 Diag(NewTagLoc, diag::warn_struct_class_previous_tag_mismatch)
13811 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13812 << getRedeclDiagFromTagKind(I->getTagKind());
13814 Diag(I->getInnerLocStart(), diag::note_struct_class_suggestion)
13815 << getRedeclDiagFromTagKind(NewTag)
13816 << FixItHint::CreateReplacement(I->getInnerLocStart(),
13817 TypeWithKeyword::getTagTypeKindName(NewTag));
13823 // Check for a previous definition. If current tag and definition
13824 // are same type, do nothing. If no definition, but disagree with
13825 // with previous tag type, give a warning, but no fix-it.
13826 const TagDecl *Redecl = Previous->getDefinition() ?
13827 Previous->getDefinition() : Previous;
13828 if (Redecl->getTagKind() == NewTag) {
13832 Diag(NewTagLoc, diag::warn_struct_class_tag_mismatch)
13833 << getRedeclDiagFromTagKind(NewTag) << isTemplate << Name
13834 << getRedeclDiagFromTagKind(OldTag);
13835 Diag(Redecl->getLocation(), diag::note_previous_use);
13837 // If there is a previous definition, suggest a fix-it.
13838 if (Previous->getDefinition()) {
13839 Diag(NewTagLoc, diag::note_struct_class_suggestion)
13840 << getRedeclDiagFromTagKind(Redecl->getTagKind())
13841 << FixItHint::CreateReplacement(SourceRange(NewTagLoc),
13842 TypeWithKeyword::getTagTypeKindName(Redecl->getTagKind()));
13850 /// Add a minimal nested name specifier fixit hint to allow lookup of a tag name
13851 /// from an outer enclosing namespace or file scope inside a friend declaration.
13852 /// This should provide the commented out code in the following snippet:
13856 /// struct Y { friend struct /*N::*/ X; };
13859 static FixItHint createFriendTagNNSFixIt(Sema &SemaRef, NamedDecl *ND, Scope *S,
13860 SourceLocation NameLoc) {
13861 // While the decl is in a namespace, do repeated lookup of that name and see
13862 // if we get the same namespace back. If we do not, continue until
13863 // translation unit scope, at which point we have a fully qualified NNS.
13864 SmallVector<IdentifierInfo *, 4> Namespaces;
13865 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
13866 for (; !DC->isTranslationUnit(); DC = DC->getParent()) {
13867 // This tag should be declared in a namespace, which can only be enclosed by
13868 // other namespaces. Bail if there's an anonymous namespace in the chain.
13869 NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(DC);
13870 if (!Namespace || Namespace->isAnonymousNamespace())
13871 return FixItHint();
13872 IdentifierInfo *II = Namespace->getIdentifier();
13873 Namespaces.push_back(II);
13874 NamedDecl *Lookup = SemaRef.LookupSingleName(
13875 S, II, NameLoc, Sema::LookupNestedNameSpecifierName);
13876 if (Lookup == Namespace)
13880 // Once we have all the namespaces, reverse them to go outermost first, and
13882 SmallString<64> Insertion;
13883 llvm::raw_svector_ostream OS(Insertion);
13884 if (DC->isTranslationUnit())
13886 std::reverse(Namespaces.begin(), Namespaces.end());
13887 for (auto *II : Namespaces)
13888 OS << II->getName() << "::";
13889 return FixItHint::CreateInsertion(NameLoc, Insertion);
13892 /// Determine whether a tag originally declared in context \p OldDC can
13893 /// be redeclared with an unqualified name in \p NewDC (assuming name lookup
13894 /// found a declaration in \p OldDC as a previous decl, perhaps through a
13895 /// using-declaration).
13896 static bool isAcceptableTagRedeclContext(Sema &S, DeclContext *OldDC,
13897 DeclContext *NewDC) {
13898 OldDC = OldDC->getRedeclContext();
13899 NewDC = NewDC->getRedeclContext();
13901 if (OldDC->Equals(NewDC))
13904 // In MSVC mode, we allow a redeclaration if the contexts are related (either
13905 // encloses the other).
13906 if (S.getLangOpts().MSVCCompat &&
13907 (OldDC->Encloses(NewDC) || NewDC->Encloses(OldDC)))
13913 /// This is invoked when we see 'struct foo' or 'struct {'. In the
13914 /// former case, Name will be non-null. In the later case, Name will be null.
13915 /// TagSpec indicates what kind of tag this is. TUK indicates whether this is a
13916 /// reference/declaration/definition of a tag.
13918 /// \param IsTypeSpecifier \c true if this is a type-specifier (or
13919 /// trailing-type-specifier) other than one in an alias-declaration.
13921 /// \param SkipBody If non-null, will be set to indicate if the caller should
13922 /// skip the definition of this tag and treat it as if it were a declaration.
13923 Decl *Sema::ActOnTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
13924 SourceLocation KWLoc, CXXScopeSpec &SS,
13925 IdentifierInfo *Name, SourceLocation NameLoc,
13926 const ParsedAttributesView &Attrs, AccessSpecifier AS,
13927 SourceLocation ModulePrivateLoc,
13928 MultiTemplateParamsArg TemplateParameterLists,
13929 bool &OwnedDecl, bool &IsDependent,
13930 SourceLocation ScopedEnumKWLoc,
13931 bool ScopedEnumUsesClassTag, TypeResult UnderlyingType,
13932 bool IsTypeSpecifier, bool IsTemplateParamOrArg,
13933 SkipBodyInfo *SkipBody) {
13934 // If this is not a definition, it must have a name.
13935 IdentifierInfo *OrigName = Name;
13936 assert((Name != nullptr || TUK == TUK_Definition) &&
13937 "Nameless record must be a definition!");
13938 assert(TemplateParameterLists.size() == 0 || TUK != TUK_Reference);
13941 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
13942 bool ScopedEnum = ScopedEnumKWLoc.isValid();
13944 // FIXME: Check member specializations more carefully.
13945 bool isMemberSpecialization = false;
13946 bool Invalid = false;
13948 // We only need to do this matching if we have template parameters
13949 // or a scope specifier, which also conveniently avoids this work
13950 // for non-C++ cases.
13951 if (TemplateParameterLists.size() > 0 ||
13952 (SS.isNotEmpty() && TUK != TUK_Reference)) {
13953 if (TemplateParameterList *TemplateParams =
13954 MatchTemplateParametersToScopeSpecifier(
13955 KWLoc, NameLoc, SS, nullptr, TemplateParameterLists,
13956 TUK == TUK_Friend, isMemberSpecialization, Invalid)) {
13957 if (Kind == TTK_Enum) {
13958 Diag(KWLoc, diag::err_enum_template);
13962 if (TemplateParams->size() > 0) {
13963 // This is a declaration or definition of a class template (which may
13964 // be a member of another template).
13970 DeclResult Result = CheckClassTemplate(
13971 S, TagSpec, TUK, KWLoc, SS, Name, NameLoc, Attrs, TemplateParams,
13972 AS, ModulePrivateLoc,
13973 /*FriendLoc*/ SourceLocation(), TemplateParameterLists.size() - 1,
13974 TemplateParameterLists.data(), SkipBody);
13975 return Result.get();
13977 // The "template<>" header is extraneous.
13978 Diag(TemplateParams->getTemplateLoc(), diag::err_template_tag_noparams)
13979 << TypeWithKeyword::getTagTypeKindName(Kind) << Name;
13980 isMemberSpecialization = true;
13985 // Figure out the underlying type if this a enum declaration. We need to do
13986 // this early, because it's needed to detect if this is an incompatible
13988 llvm::PointerUnion<const Type*, TypeSourceInfo*> EnumUnderlying;
13989 bool IsFixed = !UnderlyingType.isUnset() || ScopedEnum;
13991 if (Kind == TTK_Enum) {
13992 if (UnderlyingType.isInvalid() || (!UnderlyingType.get() && ScopedEnum)) {
13993 // No underlying type explicitly specified, or we failed to parse the
13994 // type, default to int.
13995 EnumUnderlying = Context.IntTy.getTypePtr();
13996 } else if (UnderlyingType.get()) {
13997 // C++0x 7.2p2: The type-specifier-seq of an enum-base shall name an
13998 // integral type; any cv-qualification is ignored.
13999 TypeSourceInfo *TI = nullptr;
14000 GetTypeFromParser(UnderlyingType.get(), &TI);
14001 EnumUnderlying = TI;
14003 if (CheckEnumUnderlyingType(TI))
14004 // Recover by falling back to int.
14005 EnumUnderlying = Context.IntTy.getTypePtr();
14007 if (DiagnoseUnexpandedParameterPack(TI->getTypeLoc().getBeginLoc(), TI,
14008 UPPC_FixedUnderlyingType))
14009 EnumUnderlying = Context.IntTy.getTypePtr();
14011 } else if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
14012 // For MSVC ABI compatibility, unfixed enums must use an underlying type
14013 // of 'int'. However, if this is an unfixed forward declaration, don't set
14014 // the underlying type unless the user enables -fms-compatibility. This
14015 // makes unfixed forward declared enums incomplete and is more conforming.
14016 if (TUK == TUK_Definition || getLangOpts().MSVCCompat)
14017 EnumUnderlying = Context.IntTy.getTypePtr();
14021 DeclContext *SearchDC = CurContext;
14022 DeclContext *DC = CurContext;
14023 bool isStdBadAlloc = false;
14024 bool isStdAlignValT = false;
14026 RedeclarationKind Redecl = forRedeclarationInCurContext();
14027 if (TUK == TUK_Friend || TUK == TUK_Reference)
14028 Redecl = NotForRedeclaration;
14030 /// Create a new tag decl in C/ObjC. Since the ODR-like semantics for ObjC/C
14031 /// implemented asks for structural equivalence checking, the returned decl
14032 /// here is passed back to the parser, allowing the tag body to be parsed.
14033 auto createTagFromNewDecl = [&]() -> TagDecl * {
14034 assert(!getLangOpts().CPlusPlus && "not meant for C++ usage");
14035 // If there is an identifier, use the location of the identifier as the
14036 // location of the decl, otherwise use the location of the struct/union
14038 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
14039 TagDecl *New = nullptr;
14041 if (Kind == TTK_Enum) {
14042 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name, nullptr,
14043 ScopedEnum, ScopedEnumUsesClassTag, IsFixed);
14044 // If this is an undefined enum, bail.
14045 if (TUK != TUK_Definition && !Invalid)
14047 if (EnumUnderlying) {
14048 EnumDecl *ED = cast<EnumDecl>(New);
14049 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo *>())
14050 ED->setIntegerTypeSourceInfo(TI);
14052 ED->setIntegerType(QualType(EnumUnderlying.get<const Type *>(), 0));
14053 ED->setPromotionType(ED->getIntegerType());
14055 } else { // struct/union
14056 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14060 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
14061 // Add alignment attributes if necessary; these attributes are checked
14062 // when the ASTContext lays out the structure.
14064 // It is important for implementing the correct semantics that this
14065 // happen here (in ActOnTag). The #pragma pack stack is
14066 // maintained as a result of parser callbacks which can occur at
14067 // many points during the parsing of a struct declaration (because
14068 // the #pragma tokens are effectively skipped over during the
14069 // parsing of the struct).
14070 if (TUK == TUK_Definition) {
14071 AddAlignmentAttributesForRecord(RD);
14072 AddMsStructLayoutForRecord(RD);
14075 New->setLexicalDeclContext(CurContext);
14079 LookupResult Previous(*this, Name, NameLoc, LookupTagName, Redecl);
14080 if (Name && SS.isNotEmpty()) {
14081 // We have a nested-name tag ('struct foo::bar').
14083 // Check for invalid 'foo::'.
14084 if (SS.isInvalid()) {
14086 goto CreateNewDecl;
14089 // If this is a friend or a reference to a class in a dependent
14090 // context, don't try to make a decl for it.
14091 if (TUK == TUK_Friend || TUK == TUK_Reference) {
14092 DC = computeDeclContext(SS, false);
14094 IsDependent = true;
14098 DC = computeDeclContext(SS, true);
14100 Diag(SS.getRange().getBegin(), diag::err_dependent_nested_name_spec)
14106 if (RequireCompleteDeclContext(SS, DC))
14110 // Look-up name inside 'foo::'.
14111 LookupQualifiedName(Previous, DC);
14113 if (Previous.isAmbiguous())
14116 if (Previous.empty()) {
14117 // Name lookup did not find anything. However, if the
14118 // nested-name-specifier refers to the current instantiation,
14119 // and that current instantiation has any dependent base
14120 // classes, we might find something at instantiation time: treat
14121 // this as a dependent elaborated-type-specifier.
14122 // But this only makes any sense for reference-like lookups.
14123 if (Previous.wasNotFoundInCurrentInstantiation() &&
14124 (TUK == TUK_Reference || TUK == TUK_Friend)) {
14125 IsDependent = true;
14129 // A tag 'foo::bar' must already exist.
14130 Diag(NameLoc, diag::err_not_tag_in_scope)
14131 << Kind << Name << DC << SS.getRange();
14134 goto CreateNewDecl;
14137 // C++14 [class.mem]p14:
14138 // If T is the name of a class, then each of the following shall have a
14139 // name different from T:
14140 // -- every member of class T that is itself a type
14141 if (TUK != TUK_Reference && TUK != TUK_Friend &&
14142 DiagnoseClassNameShadow(SearchDC, DeclarationNameInfo(Name, NameLoc)))
14145 // If this is a named struct, check to see if there was a previous forward
14146 // declaration or definition.
14147 // FIXME: We're looking into outer scopes here, even when we
14148 // shouldn't be. Doing so can result in ambiguities that we
14149 // shouldn't be diagnosing.
14150 LookupName(Previous, S);
14152 // When declaring or defining a tag, ignore ambiguities introduced
14153 // by types using'ed into this scope.
14154 if (Previous.isAmbiguous() &&
14155 (TUK == TUK_Definition || TUK == TUK_Declaration)) {
14156 LookupResult::Filter F = Previous.makeFilter();
14157 while (F.hasNext()) {
14158 NamedDecl *ND = F.next();
14159 if (!ND->getDeclContext()->getRedeclContext()->Equals(
14160 SearchDC->getRedeclContext()))
14166 // C++11 [namespace.memdef]p3:
14167 // If the name in a friend declaration is neither qualified nor
14168 // a template-id and the declaration is a function or an
14169 // elaborated-type-specifier, the lookup to determine whether
14170 // the entity has been previously declared shall not consider
14171 // any scopes outside the innermost enclosing namespace.
14173 // MSVC doesn't implement the above rule for types, so a friend tag
14174 // declaration may be a redeclaration of a type declared in an enclosing
14175 // scope. They do implement this rule for friend functions.
14177 // Does it matter that this should be by scope instead of by
14178 // semantic context?
14179 if (!Previous.empty() && TUK == TUK_Friend) {
14180 DeclContext *EnclosingNS = SearchDC->getEnclosingNamespaceContext();
14181 LookupResult::Filter F = Previous.makeFilter();
14182 bool FriendSawTagOutsideEnclosingNamespace = false;
14183 while (F.hasNext()) {
14184 NamedDecl *ND = F.next();
14185 DeclContext *DC = ND->getDeclContext()->getRedeclContext();
14186 if (DC->isFileContext() &&
14187 !EnclosingNS->Encloses(ND->getDeclContext())) {
14188 if (getLangOpts().MSVCCompat)
14189 FriendSawTagOutsideEnclosingNamespace = true;
14196 // Diagnose this MSVC extension in the easy case where lookup would have
14197 // unambiguously found something outside the enclosing namespace.
14198 if (Previous.isSingleResult() && FriendSawTagOutsideEnclosingNamespace) {
14199 NamedDecl *ND = Previous.getFoundDecl();
14200 Diag(NameLoc, diag::ext_friend_tag_redecl_outside_namespace)
14201 << createFriendTagNNSFixIt(*this, ND, S, NameLoc);
14205 // Note: there used to be some attempt at recovery here.
14206 if (Previous.isAmbiguous())
14209 if (!getLangOpts().CPlusPlus && TUK != TUK_Reference) {
14210 // FIXME: This makes sure that we ignore the contexts associated
14211 // with C structs, unions, and enums when looking for a matching
14212 // tag declaration or definition. See the similar lookup tweak
14213 // in Sema::LookupName; is there a better way to deal with this?
14214 while (isa<RecordDecl>(SearchDC) || isa<EnumDecl>(SearchDC))
14215 SearchDC = SearchDC->getParent();
14219 if (Previous.isSingleResult() &&
14220 Previous.getFoundDecl()->isTemplateParameter()) {
14221 // Maybe we will complain about the shadowed template parameter.
14222 DiagnoseTemplateParameterShadow(NameLoc, Previous.getFoundDecl());
14223 // Just pretend that we didn't see the previous declaration.
14227 if (getLangOpts().CPlusPlus && Name && DC && StdNamespace &&
14228 DC->Equals(getStdNamespace())) {
14229 if (Name->isStr("bad_alloc")) {
14230 // This is a declaration of or a reference to "std::bad_alloc".
14231 isStdBadAlloc = true;
14233 // If std::bad_alloc has been implicitly declared (but made invisible to
14234 // name lookup), fill in this implicit declaration as the previous
14235 // declaration, so that the declarations get chained appropriately.
14236 if (Previous.empty() && StdBadAlloc)
14237 Previous.addDecl(getStdBadAlloc());
14238 } else if (Name->isStr("align_val_t")) {
14239 isStdAlignValT = true;
14240 if (Previous.empty() && StdAlignValT)
14241 Previous.addDecl(getStdAlignValT());
14245 // If we didn't find a previous declaration, and this is a reference
14246 // (or friend reference), move to the correct scope. In C++, we
14247 // also need to do a redeclaration lookup there, just in case
14248 // there's a shadow friend decl.
14249 if (Name && Previous.empty() &&
14250 (TUK == TUK_Reference || TUK == TUK_Friend || IsTemplateParamOrArg)) {
14251 if (Invalid) goto CreateNewDecl;
14252 assert(SS.isEmpty());
14254 if (TUK == TUK_Reference || IsTemplateParamOrArg) {
14255 // C++ [basic.scope.pdecl]p5:
14256 // -- for an elaborated-type-specifier of the form
14258 // class-key identifier
14260 // if the elaborated-type-specifier is used in the
14261 // decl-specifier-seq or parameter-declaration-clause of a
14262 // function defined in namespace scope, the identifier is
14263 // declared as a class-name in the namespace that contains
14264 // the declaration; otherwise, except as a friend
14265 // declaration, the identifier is declared in the smallest
14266 // non-class, non-function-prototype scope that contains the
14269 // C99 6.7.2.3p8 has a similar (but not identical!) provision for
14270 // C structs and unions.
14272 // It is an error in C++ to declare (rather than define) an enum
14273 // type, including via an elaborated type specifier. We'll
14274 // diagnose that later; for now, declare the enum in the same
14275 // scope as we would have picked for any other tag type.
14277 // GNU C also supports this behavior as part of its incomplete
14278 // enum types extension, while GNU C++ does not.
14280 // Find the context where we'll be declaring the tag.
14281 // FIXME: We would like to maintain the current DeclContext as the
14282 // lexical context,
14283 SearchDC = getTagInjectionContext(SearchDC);
14285 // Find the scope where we'll be declaring the tag.
14286 S = getTagInjectionScope(S, getLangOpts());
14288 assert(TUK == TUK_Friend);
14289 // C++ [namespace.memdef]p3:
14290 // If a friend declaration in a non-local class first declares a
14291 // class or function, the friend class or function is a member of
14292 // the innermost enclosing namespace.
14293 SearchDC = SearchDC->getEnclosingNamespaceContext();
14296 // In C++, we need to do a redeclaration lookup to properly
14297 // diagnose some problems.
14298 // FIXME: redeclaration lookup is also used (with and without C++) to find a
14299 // hidden declaration so that we don't get ambiguity errors when using a
14300 // type declared by an elaborated-type-specifier. In C that is not correct
14301 // and we should instead merge compatible types found by lookup.
14302 if (getLangOpts().CPlusPlus) {
14303 Previous.setRedeclarationKind(forRedeclarationInCurContext());
14304 LookupQualifiedName(Previous, SearchDC);
14306 Previous.setRedeclarationKind(forRedeclarationInCurContext());
14307 LookupName(Previous, S);
14311 // If we have a known previous declaration to use, then use it.
14312 if (Previous.empty() && SkipBody && SkipBody->Previous)
14313 Previous.addDecl(SkipBody->Previous);
14315 if (!Previous.empty()) {
14316 NamedDecl *PrevDecl = Previous.getFoundDecl();
14317 NamedDecl *DirectPrevDecl = Previous.getRepresentativeDecl();
14319 // It's okay to have a tag decl in the same scope as a typedef
14320 // which hides a tag decl in the same scope. Finding this
14321 // insanity with a redeclaration lookup can only actually happen
14324 // This is also okay for elaborated-type-specifiers, which is
14325 // technically forbidden by the current standard but which is
14326 // okay according to the likely resolution of an open issue;
14327 // see http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#407
14328 if (getLangOpts().CPlusPlus) {
14329 if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(PrevDecl)) {
14330 if (const TagType *TT = TD->getUnderlyingType()->getAs<TagType>()) {
14331 TagDecl *Tag = TT->getDecl();
14332 if (Tag->getDeclName() == Name &&
14333 Tag->getDeclContext()->getRedeclContext()
14334 ->Equals(TD->getDeclContext()->getRedeclContext())) {
14337 Previous.addDecl(Tag);
14338 Previous.resolveKind();
14344 // If this is a redeclaration of a using shadow declaration, it must
14345 // declare a tag in the same context. In MSVC mode, we allow a
14346 // redefinition if either context is within the other.
14347 if (auto *Shadow = dyn_cast<UsingShadowDecl>(DirectPrevDecl)) {
14348 auto *OldTag = dyn_cast<TagDecl>(PrevDecl);
14349 if (SS.isEmpty() && TUK != TUK_Reference && TUK != TUK_Friend &&
14350 isDeclInScope(Shadow, SearchDC, S, isMemberSpecialization) &&
14351 !(OldTag && isAcceptableTagRedeclContext(
14352 *this, OldTag->getDeclContext(), SearchDC))) {
14353 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
14354 Diag(Shadow->getTargetDecl()->getLocation(),
14355 diag::note_using_decl_target);
14356 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl)
14358 // Recover by ignoring the old declaration.
14360 goto CreateNewDecl;
14364 if (TagDecl *PrevTagDecl = dyn_cast<TagDecl>(PrevDecl)) {
14365 // If this is a use of a previous tag, or if the tag is already declared
14366 // in the same scope (so that the definition/declaration completes or
14367 // rementions the tag), reuse the decl.
14368 if (TUK == TUK_Reference || TUK == TUK_Friend ||
14369 isDeclInScope(DirectPrevDecl, SearchDC, S,
14370 SS.isNotEmpty() || isMemberSpecialization)) {
14371 // Make sure that this wasn't declared as an enum and now used as a
14372 // struct or something similar.
14373 if (!isAcceptableTagRedeclaration(PrevTagDecl, Kind,
14374 TUK == TUK_Definition, KWLoc,
14376 bool SafeToContinue
14377 = (PrevTagDecl->getTagKind() != TTK_Enum &&
14379 if (SafeToContinue)
14380 Diag(KWLoc, diag::err_use_with_wrong_tag)
14382 << FixItHint::CreateReplacement(SourceRange(KWLoc),
14383 PrevTagDecl->getKindName());
14385 Diag(KWLoc, diag::err_use_with_wrong_tag) << Name;
14386 Diag(PrevTagDecl->getLocation(), diag::note_previous_use);
14388 if (SafeToContinue)
14389 Kind = PrevTagDecl->getTagKind();
14391 // Recover by making this an anonymous redefinition.
14398 if (Kind == TTK_Enum && PrevTagDecl->getTagKind() == TTK_Enum) {
14399 const EnumDecl *PrevEnum = cast<EnumDecl>(PrevTagDecl);
14401 // If this is an elaborated-type-specifier for a scoped enumeration,
14402 // the 'class' keyword is not necessary and not permitted.
14403 if (TUK == TUK_Reference || TUK == TUK_Friend) {
14405 Diag(ScopedEnumKWLoc, diag::err_enum_class_reference)
14406 << PrevEnum->isScoped()
14407 << FixItHint::CreateRemoval(ScopedEnumKWLoc);
14408 return PrevTagDecl;
14411 QualType EnumUnderlyingTy;
14412 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
14413 EnumUnderlyingTy = TI->getType().getUnqualifiedType();
14414 else if (const Type *T = EnumUnderlying.dyn_cast<const Type*>())
14415 EnumUnderlyingTy = QualType(T, 0);
14417 // All conflicts with previous declarations are recovered by
14418 // returning the previous declaration, unless this is a definition,
14419 // in which case we want the caller to bail out.
14420 if (CheckEnumRedeclaration(NameLoc.isValid() ? NameLoc : KWLoc,
14421 ScopedEnum, EnumUnderlyingTy,
14422 IsFixed, PrevEnum))
14423 return TUK == TUK_Declaration ? PrevTagDecl : nullptr;
14426 // C++11 [class.mem]p1:
14427 // A member shall not be declared twice in the member-specification,
14428 // except that a nested class or member class template can be declared
14429 // and then later defined.
14430 if (TUK == TUK_Declaration && PrevDecl->isCXXClassMember() &&
14431 S->isDeclScope(PrevDecl)) {
14432 Diag(NameLoc, diag::ext_member_redeclared);
14433 Diag(PrevTagDecl->getLocation(), diag::note_previous_declaration);
14437 // If this is a use, just return the declaration we found, unless
14438 // we have attributes.
14439 if (TUK == TUK_Reference || TUK == TUK_Friend) {
14440 if (!Attrs.empty()) {
14441 // FIXME: Diagnose these attributes. For now, we create a new
14442 // declaration to hold them.
14443 } else if (TUK == TUK_Reference &&
14444 (PrevTagDecl->getFriendObjectKind() ==
14445 Decl::FOK_Undeclared ||
14446 PrevDecl->getOwningModule() != getCurrentModule()) &&
14448 // This declaration is a reference to an existing entity, but
14449 // has different visibility from that entity: it either makes
14450 // a friend visible or it makes a type visible in a new module.
14451 // In either case, create a new declaration. We only do this if
14452 // the declaration would have meant the same thing if no prior
14453 // declaration were found, that is, if it was found in the same
14454 // scope where we would have injected a declaration.
14455 if (!getTagInjectionContext(CurContext)->getRedeclContext()
14456 ->Equals(PrevDecl->getDeclContext()->getRedeclContext()))
14457 return PrevTagDecl;
14458 // This is in the injected scope, create a new declaration in
14460 S = getTagInjectionScope(S, getLangOpts());
14462 return PrevTagDecl;
14466 // Diagnose attempts to redefine a tag.
14467 if (TUK == TUK_Definition) {
14468 if (NamedDecl *Def = PrevTagDecl->getDefinition()) {
14469 // If we're defining a specialization and the previous definition
14470 // is from an implicit instantiation, don't emit an error
14471 // here; we'll catch this in the general case below.
14472 bool IsExplicitSpecializationAfterInstantiation = false;
14473 if (isMemberSpecialization) {
14474 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Def))
14475 IsExplicitSpecializationAfterInstantiation =
14476 RD->getTemplateSpecializationKind() !=
14477 TSK_ExplicitSpecialization;
14478 else if (EnumDecl *ED = dyn_cast<EnumDecl>(Def))
14479 IsExplicitSpecializationAfterInstantiation =
14480 ED->getTemplateSpecializationKind() !=
14481 TSK_ExplicitSpecialization;
14484 // Note that clang allows ODR-like semantics for ObjC/C, i.e., do
14485 // not keep more that one definition around (merge them). However,
14486 // ensure the decl passes the structural compatibility check in
14487 // C11 6.2.7/1 (or 6.1.2.6/1 in C89).
14488 NamedDecl *Hidden = nullptr;
14489 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
14490 // There is a definition of this tag, but it is not visible. We
14491 // explicitly make use of C++'s one definition rule here, and
14492 // assume that this definition is identical to the hidden one
14493 // we already have. Make the existing definition visible and
14494 // use it in place of this one.
14495 if (!getLangOpts().CPlusPlus) {
14496 // Postpone making the old definition visible until after we
14497 // complete parsing the new one and do the structural
14499 SkipBody->CheckSameAsPrevious = true;
14500 SkipBody->New = createTagFromNewDecl();
14501 SkipBody->Previous = Hidden;
14503 SkipBody->ShouldSkip = true;
14504 makeMergedDefinitionVisible(Hidden);
14507 } else if (!IsExplicitSpecializationAfterInstantiation) {
14508 // A redeclaration in function prototype scope in C isn't
14509 // visible elsewhere, so merely issue a warning.
14510 if (!getLangOpts().CPlusPlus && S->containedInPrototypeScope())
14511 Diag(NameLoc, diag::warn_redefinition_in_param_list) << Name;
14513 Diag(NameLoc, diag::err_redefinition) << Name;
14514 notePreviousDefinition(Def,
14515 NameLoc.isValid() ? NameLoc : KWLoc);
14516 // If this is a redefinition, recover by making this
14517 // struct be anonymous, which will make any later
14518 // references get the previous definition.
14524 // If the type is currently being defined, complain
14525 // about a nested redefinition.
14526 auto *TD = Context.getTagDeclType(PrevTagDecl)->getAsTagDecl();
14527 if (TD->isBeingDefined()) {
14528 Diag(NameLoc, diag::err_nested_redefinition) << Name;
14529 Diag(PrevTagDecl->getLocation(),
14530 diag::note_previous_definition);
14537 // Okay, this is definition of a previously declared or referenced
14538 // tag. We're going to create a new Decl for it.
14541 // Okay, we're going to make a redeclaration. If this is some kind
14542 // of reference, make sure we build the redeclaration in the same DC
14543 // as the original, and ignore the current access specifier.
14544 if (TUK == TUK_Friend || TUK == TUK_Reference) {
14545 SearchDC = PrevTagDecl->getDeclContext();
14549 // If we get here we have (another) forward declaration or we
14550 // have a definition. Just create a new decl.
14553 // If we get here, this is a definition of a new tag type in a nested
14554 // scope, e.g. "struct foo; void bar() { struct foo; }", just create a
14555 // new decl/type. We set PrevDecl to NULL so that the entities
14556 // have distinct types.
14559 // If we get here, we're going to create a new Decl. If PrevDecl
14560 // is non-NULL, it's a definition of the tag declared by
14561 // PrevDecl. If it's NULL, we have a new definition.
14563 // Otherwise, PrevDecl is not a tag, but was found with tag
14564 // lookup. This is only actually possible in C++, where a few
14565 // things like templates still live in the tag namespace.
14567 // Use a better diagnostic if an elaborated-type-specifier
14568 // found the wrong kind of type on the first
14569 // (non-redeclaration) lookup.
14570 if ((TUK == TUK_Reference || TUK == TUK_Friend) &&
14571 !Previous.isForRedeclaration()) {
14572 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
14573 Diag(NameLoc, diag::err_tag_reference_non_tag) << PrevDecl << NTK
14575 Diag(PrevDecl->getLocation(), diag::note_declared_at);
14578 // Otherwise, only diagnose if the declaration is in scope.
14579 } else if (!isDeclInScope(DirectPrevDecl, SearchDC, S,
14580 SS.isNotEmpty() || isMemberSpecialization)) {
14583 // Diagnose implicit declarations introduced by elaborated types.
14584 } else if (TUK == TUK_Reference || TUK == TUK_Friend) {
14585 NonTagKind NTK = getNonTagTypeDeclKind(PrevDecl, Kind);
14586 Diag(NameLoc, diag::err_tag_reference_conflict) << NTK;
14587 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
14590 // Otherwise it's a declaration. Call out a particularly common
14592 } else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(PrevDecl)) {
14594 if (isa<TypeAliasDecl>(PrevDecl)) Kind = 1;
14595 Diag(NameLoc, diag::err_tag_definition_of_typedef)
14596 << Name << Kind << TND->getUnderlyingType();
14597 Diag(PrevDecl->getLocation(), diag::note_previous_decl) << PrevDecl;
14600 // Otherwise, diagnose.
14602 // The tag name clashes with something else in the target scope,
14603 // issue an error and recover by making this tag be anonymous.
14604 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
14605 notePreviousDefinition(PrevDecl, NameLoc);
14610 // The existing declaration isn't relevant to us; we're in a
14611 // new scope, so clear out the previous declaration.
14618 TagDecl *PrevDecl = nullptr;
14619 if (Previous.isSingleResult())
14620 PrevDecl = cast<TagDecl>(Previous.getFoundDecl());
14622 // If there is an identifier, use the location of the identifier as the
14623 // location of the decl, otherwise use the location of the struct/union
14625 SourceLocation Loc = NameLoc.isValid() ? NameLoc : KWLoc;
14627 // Otherwise, create a new declaration. If there is a previous
14628 // declaration of the same entity, the two will be linked via
14632 if (Kind == TTK_Enum) {
14633 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
14634 // enum X { A, B, C } D; D should chain to X.
14635 New = EnumDecl::Create(Context, SearchDC, KWLoc, Loc, Name,
14636 cast_or_null<EnumDecl>(PrevDecl), ScopedEnum,
14637 ScopedEnumUsesClassTag, IsFixed);
14639 if (isStdAlignValT && (!StdAlignValT || getStdAlignValT()->isImplicit()))
14640 StdAlignValT = cast<EnumDecl>(New);
14642 // If this is an undefined enum, warn.
14643 if (TUK != TUK_Definition && !Invalid) {
14645 if (IsFixed && (getLangOpts().CPlusPlus11 || getLangOpts().ObjC2) &&
14646 cast<EnumDecl>(New)->isFixed()) {
14647 // C++0x: 7.2p2: opaque-enum-declaration.
14648 // Conflicts are diagnosed above. Do nothing.
14650 else if (PrevDecl && (Def = cast<EnumDecl>(PrevDecl)->getDefinition())) {
14651 Diag(Loc, diag::ext_forward_ref_enum_def)
14653 Diag(Def->getLocation(), diag::note_previous_definition);
14655 unsigned DiagID = diag::ext_forward_ref_enum;
14656 if (getLangOpts().MSVCCompat)
14657 DiagID = diag::ext_ms_forward_ref_enum;
14658 else if (getLangOpts().CPlusPlus)
14659 DiagID = diag::err_forward_ref_enum;
14664 if (EnumUnderlying) {
14665 EnumDecl *ED = cast<EnumDecl>(New);
14666 if (TypeSourceInfo *TI = EnumUnderlying.dyn_cast<TypeSourceInfo*>())
14667 ED->setIntegerTypeSourceInfo(TI);
14669 ED->setIntegerType(QualType(EnumUnderlying.get<const Type*>(), 0));
14670 ED->setPromotionType(ED->getIntegerType());
14671 assert(ED->isComplete() && "enum with type should be complete");
14674 // struct/union/class
14676 // FIXME: Tag decls should be chained to any simultaneous vardecls, e.g.:
14677 // struct X { int A; } D; D should chain to X.
14678 if (getLangOpts().CPlusPlus) {
14679 // FIXME: Look for a way to use RecordDecl for simple structs.
14680 New = CXXRecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14681 cast_or_null<CXXRecordDecl>(PrevDecl));
14683 if (isStdBadAlloc && (!StdBadAlloc || getStdBadAlloc()->isImplicit()))
14684 StdBadAlloc = cast<CXXRecordDecl>(New);
14686 New = RecordDecl::Create(Context, Kind, SearchDC, KWLoc, Loc, Name,
14687 cast_or_null<RecordDecl>(PrevDecl));
14690 // C++11 [dcl.type]p3:
14691 // A type-specifier-seq shall not define a class or enumeration [...].
14692 if (getLangOpts().CPlusPlus && (IsTypeSpecifier || IsTemplateParamOrArg) &&
14693 TUK == TUK_Definition) {
14694 Diag(New->getLocation(), diag::err_type_defined_in_type_specifier)
14695 << Context.getTagDeclType(New);
14699 if (!Invalid && getLangOpts().CPlusPlus && TUK == TUK_Definition &&
14700 DC->getDeclKind() == Decl::Enum) {
14701 Diag(New->getLocation(), diag::err_type_defined_in_enum)
14702 << Context.getTagDeclType(New);
14706 // Maybe add qualifier info.
14707 if (SS.isNotEmpty()) {
14709 // If this is either a declaration or a definition, check the
14710 // nested-name-specifier against the current context.
14711 if ((TUK == TUK_Definition || TUK == TUK_Declaration) &&
14712 diagnoseQualifiedDeclaration(SS, DC, OrigName, Loc,
14713 isMemberSpecialization))
14716 New->setQualifierInfo(SS.getWithLocInContext(Context));
14717 if (TemplateParameterLists.size() > 0) {
14718 New->setTemplateParameterListsInfo(Context, TemplateParameterLists);
14725 if (RecordDecl *RD = dyn_cast<RecordDecl>(New)) {
14726 // Add alignment attributes if necessary; these attributes are checked when
14727 // the ASTContext lays out the structure.
14729 // It is important for implementing the correct semantics that this
14730 // happen here (in ActOnTag). The #pragma pack stack is
14731 // maintained as a result of parser callbacks which can occur at
14732 // many points during the parsing of a struct declaration (because
14733 // the #pragma tokens are effectively skipped over during the
14734 // parsing of the struct).
14735 if (TUK == TUK_Definition) {
14736 AddAlignmentAttributesForRecord(RD);
14737 AddMsStructLayoutForRecord(RD);
14741 if (ModulePrivateLoc.isValid()) {
14742 if (isMemberSpecialization)
14743 Diag(New->getLocation(), diag::err_module_private_specialization)
14745 << FixItHint::CreateRemoval(ModulePrivateLoc);
14746 // __module_private__ does not apply to local classes. However, we only
14747 // diagnose this as an error when the declaration specifiers are
14748 // freestanding. Here, we just ignore the __module_private__.
14749 else if (!SearchDC->isFunctionOrMethod())
14750 New->setModulePrivate();
14753 // If this is a specialization of a member class (of a class template),
14754 // check the specialization.
14755 if (isMemberSpecialization && CheckMemberSpecialization(New, Previous))
14758 // If we're declaring or defining a tag in function prototype scope in C,
14759 // note that this type can only be used within the function and add it to
14760 // the list of decls to inject into the function definition scope.
14761 if ((Name || Kind == TTK_Enum) &&
14762 getNonFieldDeclScope(S)->isFunctionPrototypeScope()) {
14763 if (getLangOpts().CPlusPlus) {
14764 // C++ [dcl.fct]p6:
14765 // Types shall not be defined in return or parameter types.
14766 if (TUK == TUK_Definition && !IsTypeSpecifier) {
14767 Diag(Loc, diag::err_type_defined_in_param_type)
14771 } else if (!PrevDecl) {
14772 Diag(Loc, diag::warn_decl_in_param_list) << Context.getTagDeclType(New);
14777 New->setInvalidDecl();
14779 // Set the lexical context. If the tag has a C++ scope specifier, the
14780 // lexical context will be different from the semantic context.
14781 New->setLexicalDeclContext(CurContext);
14783 // Mark this as a friend decl if applicable.
14784 // In Microsoft mode, a friend declaration also acts as a forward
14785 // declaration so we always pass true to setObjectOfFriendDecl to make
14786 // the tag name visible.
14787 if (TUK == TUK_Friend)
14788 New->setObjectOfFriendDecl(getLangOpts().MSVCCompat);
14790 // Set the access specifier.
14791 if (!Invalid && SearchDC->isRecord())
14792 SetMemberAccessSpecifier(New, PrevDecl, AS);
14795 CheckRedeclarationModuleOwnership(New, PrevDecl);
14797 if (TUK == TUK_Definition)
14798 New->startDefinition();
14800 ProcessDeclAttributeList(S, New, Attrs);
14801 AddPragmaAttributes(S, New);
14803 // If this has an identifier, add it to the scope stack.
14804 if (TUK == TUK_Friend) {
14805 // We might be replacing an existing declaration in the lookup tables;
14806 // if so, borrow its access specifier.
14808 New->setAccess(PrevDecl->getAccess());
14810 DeclContext *DC = New->getDeclContext()->getRedeclContext();
14811 DC->makeDeclVisibleInContext(New);
14812 if (Name) // can be null along some error paths
14813 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
14814 PushOnScopeChains(New, EnclosingScope, /* AddToContext = */ false);
14816 S = getNonFieldDeclScope(S);
14817 PushOnScopeChains(New, S, true);
14819 CurContext->addDecl(New);
14822 // If this is the C FILE type, notify the AST context.
14823 if (IdentifierInfo *II = New->getIdentifier())
14824 if (!New->isInvalidDecl() &&
14825 New->getDeclContext()->getRedeclContext()->isTranslationUnit() &&
14827 Context.setFILEDecl(New);
14830 mergeDeclAttributes(New, PrevDecl);
14832 // If there's a #pragma GCC visibility in scope, set the visibility of this
14834 AddPushedVisibilityAttribute(New);
14836 if (isMemberSpecialization && !New->isInvalidDecl())
14837 CompleteMemberSpecialization(New, Previous);
14840 // In C++, don't return an invalid declaration. We can't recover well from
14841 // the cases where we make the type anonymous.
14842 if (Invalid && getLangOpts().CPlusPlus) {
14843 if (New->isBeingDefined())
14844 if (auto RD = dyn_cast<RecordDecl>(New))
14845 RD->completeDefinition();
14852 void Sema::ActOnTagStartDefinition(Scope *S, Decl *TagD) {
14853 AdjustDeclIfTemplate(TagD);
14854 TagDecl *Tag = cast<TagDecl>(TagD);
14856 // Enter the tag context.
14857 PushDeclContext(S, Tag);
14859 ActOnDocumentableDecl(TagD);
14861 // If there's a #pragma GCC visibility in scope, set the visibility of this
14863 AddPushedVisibilityAttribute(Tag);
14866 bool Sema::ActOnDuplicateDefinition(DeclSpec &DS, Decl *Prev,
14867 SkipBodyInfo &SkipBody) {
14868 if (!hasStructuralCompatLayout(Prev, SkipBody.New))
14871 // Make the previous decl visible.
14872 makeMergedDefinitionVisible(SkipBody.Previous);
14876 Decl *Sema::ActOnObjCContainerStartDefinition(Decl *IDecl) {
14877 assert(isa<ObjCContainerDecl>(IDecl) &&
14878 "ActOnObjCContainerStartDefinition - Not ObjCContainerDecl");
14879 DeclContext *OCD = cast<DeclContext>(IDecl);
14880 assert(getContainingDC(OCD) == CurContext &&
14881 "The next DeclContext should be lexically contained in the current one.");
14886 void Sema::ActOnStartCXXMemberDeclarations(Scope *S, Decl *TagD,
14887 SourceLocation FinalLoc,
14888 bool IsFinalSpelledSealed,
14889 SourceLocation LBraceLoc) {
14890 AdjustDeclIfTemplate(TagD);
14891 CXXRecordDecl *Record = cast<CXXRecordDecl>(TagD);
14893 FieldCollector->StartClass();
14895 if (!Record->getIdentifier())
14898 if (FinalLoc.isValid())
14899 Record->addAttr(new (Context)
14900 FinalAttr(FinalLoc, Context, IsFinalSpelledSealed));
14903 // [...] The class-name is also inserted into the scope of the
14904 // class itself; this is known as the injected-class-name. For
14905 // purposes of access checking, the injected-class-name is treated
14906 // as if it were a public member name.
14907 CXXRecordDecl *InjectedClassName
14908 = CXXRecordDecl::Create(Context, Record->getTagKind(), CurContext,
14909 Record->getLocStart(), Record->getLocation(),
14910 Record->getIdentifier(),
14911 /*PrevDecl=*/nullptr,
14912 /*DelayTypeCreation=*/true);
14913 Context.getTypeDeclType(InjectedClassName, Record);
14914 InjectedClassName->setImplicit();
14915 InjectedClassName->setAccess(AS_public);
14916 if (ClassTemplateDecl *Template = Record->getDescribedClassTemplate())
14917 InjectedClassName->setDescribedClassTemplate(Template);
14918 PushOnScopeChains(InjectedClassName, S);
14919 assert(InjectedClassName->isInjectedClassName() &&
14920 "Broken injected-class-name");
14923 void Sema::ActOnTagFinishDefinition(Scope *S, Decl *TagD,
14924 SourceRange BraceRange) {
14925 AdjustDeclIfTemplate(TagD);
14926 TagDecl *Tag = cast<TagDecl>(TagD);
14927 Tag->setBraceRange(BraceRange);
14929 // Make sure we "complete" the definition even it is invalid.
14930 if (Tag->isBeingDefined()) {
14931 assert(Tag->isInvalidDecl() && "We should already have completed it");
14932 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
14933 RD->completeDefinition();
14936 if (isa<CXXRecordDecl>(Tag)) {
14937 FieldCollector->FinishClass();
14940 // Exit this scope of this tag's definition.
14943 if (getCurLexicalContext()->isObjCContainer() &&
14944 Tag->getDeclContext()->isFileContext())
14945 Tag->setTopLevelDeclInObjCContainer();
14947 // Notify the consumer that we've defined a tag.
14948 if (!Tag->isInvalidDecl())
14949 Consumer.HandleTagDeclDefinition(Tag);
14952 void Sema::ActOnObjCContainerFinishDefinition() {
14953 // Exit this scope of this interface definition.
14957 void Sema::ActOnObjCTemporaryExitContainerContext(DeclContext *DC) {
14958 assert(DC == CurContext && "Mismatch of container contexts");
14959 OriginalLexicalContext = DC;
14960 ActOnObjCContainerFinishDefinition();
14963 void Sema::ActOnObjCReenterContainerContext(DeclContext *DC) {
14964 ActOnObjCContainerStartDefinition(cast<Decl>(DC));
14965 OriginalLexicalContext = nullptr;
14968 void Sema::ActOnTagDefinitionError(Scope *S, Decl *TagD) {
14969 AdjustDeclIfTemplate(TagD);
14970 TagDecl *Tag = cast<TagDecl>(TagD);
14971 Tag->setInvalidDecl();
14973 // Make sure we "complete" the definition even it is invalid.
14974 if (Tag->isBeingDefined()) {
14975 if (RecordDecl *RD = dyn_cast<RecordDecl>(Tag))
14976 RD->completeDefinition();
14979 // We're undoing ActOnTagStartDefinition here, not
14980 // ActOnStartCXXMemberDeclarations, so we don't have to mess with
14981 // the FieldCollector.
14986 // Note that FieldName may be null for anonymous bitfields.
14987 ExprResult Sema::VerifyBitField(SourceLocation FieldLoc,
14988 IdentifierInfo *FieldName,
14989 QualType FieldTy, bool IsMsStruct,
14990 Expr *BitWidth, bool *ZeroWidth) {
14991 // Default to true; that shouldn't confuse checks for emptiness
14995 // C99 6.7.2.1p4 - verify the field type.
14996 // C++ 9.6p3: A bit-field shall have integral or enumeration type.
14997 if (!FieldTy->isDependentType() && !FieldTy->isIntegralOrEnumerationType()) {
14998 // Handle incomplete types with specific error.
14999 if (RequireCompleteType(FieldLoc, FieldTy, diag::err_field_incomplete))
15000 return ExprError();
15002 return Diag(FieldLoc, diag::err_not_integral_type_bitfield)
15003 << FieldName << FieldTy << BitWidth->getSourceRange();
15004 return Diag(FieldLoc, diag::err_not_integral_type_anon_bitfield)
15005 << FieldTy << BitWidth->getSourceRange();
15006 } else if (DiagnoseUnexpandedParameterPack(const_cast<Expr *>(BitWidth),
15007 UPPC_BitFieldWidth))
15008 return ExprError();
15010 // If the bit-width is type- or value-dependent, don't try to check
15012 if (BitWidth->isValueDependent() || BitWidth->isTypeDependent())
15015 llvm::APSInt Value;
15016 ExprResult ICE = VerifyIntegerConstantExpression(BitWidth, &Value);
15017 if (ICE.isInvalid())
15019 BitWidth = ICE.get();
15021 if (Value != 0 && ZeroWidth)
15022 *ZeroWidth = false;
15024 // Zero-width bitfield is ok for anonymous field.
15025 if (Value == 0 && FieldName)
15026 return Diag(FieldLoc, diag::err_bitfield_has_zero_width) << FieldName;
15028 if (Value.isSigned() && Value.isNegative()) {
15030 return Diag(FieldLoc, diag::err_bitfield_has_negative_width)
15031 << FieldName << Value.toString(10);
15032 return Diag(FieldLoc, diag::err_anon_bitfield_has_negative_width)
15033 << Value.toString(10);
15036 if (!FieldTy->isDependentType()) {
15037 uint64_t TypeStorageSize = Context.getTypeSize(FieldTy);
15038 uint64_t TypeWidth = Context.getIntWidth(FieldTy);
15039 bool BitfieldIsOverwide = Value.ugt(TypeWidth);
15041 // Over-wide bitfields are an error in C or when using the MSVC bitfield
15043 bool CStdConstraintViolation =
15044 BitfieldIsOverwide && !getLangOpts().CPlusPlus;
15045 bool MSBitfieldViolation =
15046 Value.ugt(TypeStorageSize) &&
15047 (IsMsStruct || Context.getTargetInfo().getCXXABI().isMicrosoft());
15048 if (CStdConstraintViolation || MSBitfieldViolation) {
15049 unsigned DiagWidth =
15050 CStdConstraintViolation ? TypeWidth : TypeStorageSize;
15052 return Diag(FieldLoc, diag::err_bitfield_width_exceeds_type_width)
15053 << FieldName << (unsigned)Value.getZExtValue()
15054 << !CStdConstraintViolation << DiagWidth;
15056 return Diag(FieldLoc, diag::err_anon_bitfield_width_exceeds_type_width)
15057 << (unsigned)Value.getZExtValue() << !CStdConstraintViolation
15061 // Warn on types where the user might conceivably expect to get all
15062 // specified bits as value bits: that's all integral types other than
15064 if (BitfieldIsOverwide && !FieldTy->isBooleanType()) {
15066 Diag(FieldLoc, diag::warn_bitfield_width_exceeds_type_width)
15067 << FieldName << (unsigned)Value.getZExtValue()
15068 << (unsigned)TypeWidth;
15070 Diag(FieldLoc, diag::warn_anon_bitfield_width_exceeds_type_width)
15071 << (unsigned)Value.getZExtValue() << (unsigned)TypeWidth;
15078 /// ActOnField - Each field of a C struct/union is passed into this in order
15079 /// to create a FieldDecl object for it.
15080 Decl *Sema::ActOnField(Scope *S, Decl *TagD, SourceLocation DeclStart,
15081 Declarator &D, Expr *BitfieldWidth) {
15082 FieldDecl *Res = HandleField(S, cast_or_null<RecordDecl>(TagD),
15083 DeclStart, D, static_cast<Expr*>(BitfieldWidth),
15084 /*InitStyle=*/ICIS_NoInit, AS_public);
15088 /// HandleField - Analyze a field of a C struct or a C++ data member.
15090 FieldDecl *Sema::HandleField(Scope *S, RecordDecl *Record,
15091 SourceLocation DeclStart,
15092 Declarator &D, Expr *BitWidth,
15093 InClassInitStyle InitStyle,
15094 AccessSpecifier AS) {
15095 if (D.isDecompositionDeclarator()) {
15096 const DecompositionDeclarator &Decomp = D.getDecompositionDeclarator();
15097 Diag(Decomp.getLSquareLoc(), diag::err_decomp_decl_context)
15098 << Decomp.getSourceRange();
15102 IdentifierInfo *II = D.getIdentifier();
15103 SourceLocation Loc = DeclStart;
15104 if (II) Loc = D.getIdentifierLoc();
15106 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15107 QualType T = TInfo->getType();
15108 if (getLangOpts().CPlusPlus) {
15109 CheckExtraCXXDefaultArguments(D);
15111 if (DiagnoseUnexpandedParameterPack(D.getIdentifierLoc(), TInfo,
15112 UPPC_DataMemberType)) {
15113 D.setInvalidType();
15115 TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
15119 // TR 18037 does not allow fields to be declared with address spaces.
15120 if (T.getQualifiers().hasAddressSpace() ||
15121 T->isDependentAddressSpaceType() ||
15122 T->getBaseElementTypeUnsafe()->isDependentAddressSpaceType()) {
15123 Diag(Loc, diag::err_field_with_address_space);
15124 D.setInvalidType();
15127 // OpenCL v1.2 s6.9b,r & OpenCL v2.0 s6.12.5 - The following types cannot be
15128 // used as structure or union field: image, sampler, event or block types.
15129 if (LangOpts.OpenCL && (T->isEventT() || T->isImageType() ||
15130 T->isSamplerT() || T->isBlockPointerType())) {
15131 Diag(Loc, diag::err_opencl_type_struct_or_union_field) << T;
15132 D.setInvalidType();
15135 DiagnoseFunctionSpecifiers(D.getDeclSpec());
15137 if (D.getDeclSpec().isInlineSpecified())
15138 Diag(D.getDeclSpec().getInlineSpecLoc(), diag::err_inline_non_function)
15139 << getLangOpts().CPlusPlus17;
15140 if (DeclSpec::TSCS TSCS = D.getDeclSpec().getThreadStorageClassSpec())
15141 Diag(D.getDeclSpec().getThreadStorageClassSpecLoc(),
15142 diag::err_invalid_thread)
15143 << DeclSpec::getSpecifierName(TSCS);
15145 // Check to see if this name was declared as a member previously
15146 NamedDecl *PrevDecl = nullptr;
15147 LookupResult Previous(*this, II, Loc, LookupMemberName,
15148 ForVisibleRedeclaration);
15149 LookupName(Previous, S);
15150 switch (Previous.getResultKind()) {
15151 case LookupResult::Found:
15152 case LookupResult::FoundUnresolvedValue:
15153 PrevDecl = Previous.getAsSingle<NamedDecl>();
15156 case LookupResult::FoundOverloaded:
15157 PrevDecl = Previous.getRepresentativeDecl();
15160 case LookupResult::NotFound:
15161 case LookupResult::NotFoundInCurrentInstantiation:
15162 case LookupResult::Ambiguous:
15165 Previous.suppressDiagnostics();
15167 if (PrevDecl && PrevDecl->isTemplateParameter()) {
15168 // Maybe we will complain about the shadowed template parameter.
15169 DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
15170 // Just pretend that we didn't see the previous declaration.
15171 PrevDecl = nullptr;
15174 if (PrevDecl && !isDeclInScope(PrevDecl, Record, S))
15175 PrevDecl = nullptr;
15178 = (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_mutable);
15179 SourceLocation TSSL = D.getLocStart();
15181 = CheckFieldDecl(II, T, TInfo, Record, Loc, Mutable, BitWidth, InitStyle,
15182 TSSL, AS, PrevDecl, &D);
15184 if (NewFD->isInvalidDecl())
15185 Record->setInvalidDecl();
15187 if (D.getDeclSpec().isModulePrivateSpecified())
15188 NewFD->setModulePrivate();
15190 if (NewFD->isInvalidDecl() && PrevDecl) {
15191 // Don't introduce NewFD into scope; there's already something
15192 // with the same name in the same scope.
15194 PushOnScopeChains(NewFD, S);
15196 Record->addDecl(NewFD);
15201 /// Build a new FieldDecl and check its well-formedness.
15203 /// This routine builds a new FieldDecl given the fields name, type,
15204 /// record, etc. \p PrevDecl should refer to any previous declaration
15205 /// with the same name and in the same scope as the field to be
15208 /// \returns a new FieldDecl.
15210 /// \todo The Declarator argument is a hack. It will be removed once
15211 FieldDecl *Sema::CheckFieldDecl(DeclarationName Name, QualType T,
15212 TypeSourceInfo *TInfo,
15213 RecordDecl *Record, SourceLocation Loc,
15214 bool Mutable, Expr *BitWidth,
15215 InClassInitStyle InitStyle,
15216 SourceLocation TSSL,
15217 AccessSpecifier AS, NamedDecl *PrevDecl,
15219 IdentifierInfo *II = Name.getAsIdentifierInfo();
15220 bool InvalidDecl = false;
15221 if (D) InvalidDecl = D->isInvalidType();
15223 // If we receive a broken type, recover by assuming 'int' and
15224 // marking this declaration as invalid.
15226 InvalidDecl = true;
15230 QualType EltTy = Context.getBaseElementType(T);
15231 if (!EltTy->isDependentType()) {
15232 if (RequireCompleteType(Loc, EltTy, diag::err_field_incomplete)) {
15233 // Fields of incomplete type force their record to be invalid.
15234 Record->setInvalidDecl();
15235 InvalidDecl = true;
15238 EltTy->isIncompleteType(&Def);
15239 if (Def && Def->isInvalidDecl()) {
15240 Record->setInvalidDecl();
15241 InvalidDecl = true;
15246 // OpenCL v1.2 s6.9.c: bitfields are not supported.
15247 if (BitWidth && getLangOpts().OpenCL) {
15248 Diag(Loc, diag::err_opencl_bitfields);
15249 InvalidDecl = true;
15252 // Anonymous bit-fields cannot be cv-qualified (CWG 2229).
15253 if (!InvalidDecl && getLangOpts().CPlusPlus && !II && BitWidth &&
15254 T.hasQualifiers()) {
15255 InvalidDecl = true;
15256 Diag(Loc, diag::err_anon_bitfield_qualifiers);
15259 // C99 6.7.2.1p8: A member of a structure or union may have any type other
15260 // than a variably modified type.
15261 if (!InvalidDecl && T->isVariablyModifiedType()) {
15262 bool SizeIsNegative;
15263 llvm::APSInt Oversized;
15265 TypeSourceInfo *FixedTInfo =
15266 TryToFixInvalidVariablyModifiedTypeSourceInfo(TInfo, Context,
15270 Diag(Loc, diag::warn_illegal_constant_array_size);
15271 TInfo = FixedTInfo;
15272 T = FixedTInfo->getType();
15274 if (SizeIsNegative)
15275 Diag(Loc, diag::err_typecheck_negative_array_size);
15276 else if (Oversized.getBoolValue())
15277 Diag(Loc, diag::err_array_too_large)
15278 << Oversized.toString(10);
15280 Diag(Loc, diag::err_typecheck_field_variable_size);
15281 InvalidDecl = true;
15285 // Fields can not have abstract class types
15286 if (!InvalidDecl && RequireNonAbstractType(Loc, T,
15287 diag::err_abstract_type_in_decl,
15288 AbstractFieldType))
15289 InvalidDecl = true;
15291 bool ZeroWidth = false;
15293 BitWidth = nullptr;
15294 // If this is declared as a bit-field, check the bit-field.
15296 BitWidth = VerifyBitField(Loc, II, T, Record->isMsStruct(Context), BitWidth,
15299 InvalidDecl = true;
15300 BitWidth = nullptr;
15305 // Check that 'mutable' is consistent with the type of the declaration.
15306 if (!InvalidDecl && Mutable) {
15307 unsigned DiagID = 0;
15308 if (T->isReferenceType())
15309 DiagID = getLangOpts().MSVCCompat ? diag::ext_mutable_reference
15310 : diag::err_mutable_reference;
15311 else if (T.isConstQualified())
15312 DiagID = diag::err_mutable_const;
15315 SourceLocation ErrLoc = Loc;
15316 if (D && D->getDeclSpec().getStorageClassSpecLoc().isValid())
15317 ErrLoc = D->getDeclSpec().getStorageClassSpecLoc();
15318 Diag(ErrLoc, DiagID);
15319 if (DiagID != diag::ext_mutable_reference) {
15321 InvalidDecl = true;
15326 // C++11 [class.union]p8 (DR1460):
15327 // At most one variant member of a union may have a
15328 // brace-or-equal-initializer.
15329 if (InitStyle != ICIS_NoInit)
15330 checkDuplicateDefaultInit(*this, cast<CXXRecordDecl>(Record), Loc);
15332 FieldDecl *NewFD = FieldDecl::Create(Context, Record, TSSL, Loc, II, T, TInfo,
15333 BitWidth, Mutable, InitStyle);
15335 NewFD->setInvalidDecl();
15337 if (PrevDecl && !isa<TagDecl>(PrevDecl)) {
15338 Diag(Loc, diag::err_duplicate_member) << II;
15339 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
15340 NewFD->setInvalidDecl();
15343 if (!InvalidDecl && getLangOpts().CPlusPlus) {
15344 if (Record->isUnion()) {
15345 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
15346 CXXRecordDecl* RDecl = cast<CXXRecordDecl>(RT->getDecl());
15347 if (RDecl->getDefinition()) {
15348 // C++ [class.union]p1: An object of a class with a non-trivial
15349 // constructor, a non-trivial copy constructor, a non-trivial
15350 // destructor, or a non-trivial copy assignment operator
15351 // cannot be a member of a union, nor can an array of such
15353 if (CheckNontrivialField(NewFD))
15354 NewFD->setInvalidDecl();
15358 // C++ [class.union]p1: If a union contains a member of reference type,
15359 // the program is ill-formed, except when compiling with MSVC extensions
15361 if (EltTy->isReferenceType()) {
15362 Diag(NewFD->getLocation(), getLangOpts().MicrosoftExt ?
15363 diag::ext_union_member_of_reference_type :
15364 diag::err_union_member_of_reference_type)
15365 << NewFD->getDeclName() << EltTy;
15366 if (!getLangOpts().MicrosoftExt)
15367 NewFD->setInvalidDecl();
15372 // FIXME: We need to pass in the attributes given an AST
15373 // representation, not a parser representation.
15375 // FIXME: The current scope is almost... but not entirely... correct here.
15376 ProcessDeclAttributes(getCurScope(), NewFD, *D);
15378 if (NewFD->hasAttrs())
15379 CheckAlignasUnderalignment(NewFD);
15382 // In auto-retain/release, infer strong retension for fields of
15383 // retainable type.
15384 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewFD))
15385 NewFD->setInvalidDecl();
15387 if (T.isObjCGCWeak())
15388 Diag(Loc, diag::warn_attribute_weak_on_field);
15390 NewFD->setAccess(AS);
15394 bool Sema::CheckNontrivialField(FieldDecl *FD) {
15396 assert(getLangOpts().CPlusPlus && "valid check only for C++");
15398 if (FD->isInvalidDecl() || FD->getType()->isDependentType())
15401 QualType EltTy = Context.getBaseElementType(FD->getType());
15402 if (const RecordType *RT = EltTy->getAs<RecordType>()) {
15403 CXXRecordDecl *RDecl = cast<CXXRecordDecl>(RT->getDecl());
15404 if (RDecl->getDefinition()) {
15405 // We check for copy constructors before constructors
15406 // because otherwise we'll never get complaints about
15407 // copy constructors.
15409 CXXSpecialMember member = CXXInvalid;
15410 // We're required to check for any non-trivial constructors. Since the
15411 // implicit default constructor is suppressed if there are any
15412 // user-declared constructors, we just need to check that there is a
15413 // trivial default constructor and a trivial copy constructor. (We don't
15414 // worry about move constructors here, since this is a C++98 check.)
15415 if (RDecl->hasNonTrivialCopyConstructor())
15416 member = CXXCopyConstructor;
15417 else if (!RDecl->hasTrivialDefaultConstructor())
15418 member = CXXDefaultConstructor;
15419 else if (RDecl->hasNonTrivialCopyAssignment())
15420 member = CXXCopyAssignment;
15421 else if (RDecl->hasNonTrivialDestructor())
15422 member = CXXDestructor;
15424 if (member != CXXInvalid) {
15425 if (!getLangOpts().CPlusPlus11 &&
15426 getLangOpts().ObjCAutoRefCount && RDecl->hasObjectMember()) {
15427 // Objective-C++ ARC: it is an error to have a non-trivial field of
15428 // a union. However, system headers in Objective-C programs
15429 // occasionally have Objective-C lifetime objects within unions,
15430 // and rather than cause the program to fail, we make those
15431 // members unavailable.
15432 SourceLocation Loc = FD->getLocation();
15433 if (getSourceManager().isInSystemHeader(Loc)) {
15434 if (!FD->hasAttr<UnavailableAttr>())
15435 FD->addAttr(UnavailableAttr::CreateImplicit(Context, "",
15436 UnavailableAttr::IR_ARCFieldWithOwnership, Loc));
15441 Diag(FD->getLocation(), getLangOpts().CPlusPlus11 ?
15442 diag::warn_cxx98_compat_nontrivial_union_or_anon_struct_member :
15443 diag::err_illegal_union_or_anon_struct_member)
15444 << FD->getParent()->isUnion() << FD->getDeclName() << member;
15445 DiagnoseNontrivial(RDecl, member);
15446 return !getLangOpts().CPlusPlus11;
15454 /// TranslateIvarVisibility - Translate visibility from a token ID to an
15455 /// AST enum value.
15456 static ObjCIvarDecl::AccessControl
15457 TranslateIvarVisibility(tok::ObjCKeywordKind ivarVisibility) {
15458 switch (ivarVisibility) {
15459 default: llvm_unreachable("Unknown visitibility kind");
15460 case tok::objc_private: return ObjCIvarDecl::Private;
15461 case tok::objc_public: return ObjCIvarDecl::Public;
15462 case tok::objc_protected: return ObjCIvarDecl::Protected;
15463 case tok::objc_package: return ObjCIvarDecl::Package;
15467 /// ActOnIvar - Each ivar field of an objective-c class is passed into this
15468 /// in order to create an IvarDecl object for it.
15469 Decl *Sema::ActOnIvar(Scope *S,
15470 SourceLocation DeclStart,
15471 Declarator &D, Expr *BitfieldWidth,
15472 tok::ObjCKeywordKind Visibility) {
15474 IdentifierInfo *II = D.getIdentifier();
15475 Expr *BitWidth = (Expr*)BitfieldWidth;
15476 SourceLocation Loc = DeclStart;
15477 if (II) Loc = D.getIdentifierLoc();
15479 // FIXME: Unnamed fields can be handled in various different ways, for
15480 // example, unnamed unions inject all members into the struct namespace!
15482 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
15483 QualType T = TInfo->getType();
15486 // 6.7.2.1p3, 6.7.2.1p4
15487 BitWidth = VerifyBitField(Loc, II, T, /*IsMsStruct*/false, BitWidth).get();
15489 D.setInvalidType();
15496 if (T->isReferenceType()) {
15497 Diag(Loc, diag::err_ivar_reference_type);
15498 D.setInvalidType();
15500 // C99 6.7.2.1p8: A member of a structure or union may have any type other
15501 // than a variably modified type.
15502 else if (T->isVariablyModifiedType()) {
15503 Diag(Loc, diag::err_typecheck_ivar_variable_size);
15504 D.setInvalidType();
15507 // Get the visibility (access control) for this ivar.
15508 ObjCIvarDecl::AccessControl ac =
15509 Visibility != tok::objc_not_keyword ? TranslateIvarVisibility(Visibility)
15510 : ObjCIvarDecl::None;
15511 // Must set ivar's DeclContext to its enclosing interface.
15512 ObjCContainerDecl *EnclosingDecl = cast<ObjCContainerDecl>(CurContext);
15513 if (!EnclosingDecl || EnclosingDecl->isInvalidDecl())
15515 ObjCContainerDecl *EnclosingContext;
15516 if (ObjCImplementationDecl *IMPDecl =
15517 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
15518 if (LangOpts.ObjCRuntime.isFragile()) {
15519 // Case of ivar declared in an implementation. Context is that of its class.
15520 EnclosingContext = IMPDecl->getClassInterface();
15521 assert(EnclosingContext && "Implementation has no class interface!");
15524 EnclosingContext = EnclosingDecl;
15526 if (ObjCCategoryDecl *CDecl =
15527 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) {
15528 if (LangOpts.ObjCRuntime.isFragile() || !CDecl->IsClassExtension()) {
15529 Diag(Loc, diag::err_misplaced_ivar) << CDecl->IsClassExtension();
15533 EnclosingContext = EnclosingDecl;
15536 // Construct the decl.
15537 ObjCIvarDecl *NewID = ObjCIvarDecl::Create(Context, EnclosingContext,
15538 DeclStart, Loc, II, T,
15539 TInfo, ac, (Expr *)BitfieldWidth);
15542 NamedDecl *PrevDecl = LookupSingleName(S, II, Loc, LookupMemberName,
15543 ForVisibleRedeclaration);
15544 if (PrevDecl && isDeclInScope(PrevDecl, EnclosingContext, S)
15545 && !isa<TagDecl>(PrevDecl)) {
15546 Diag(Loc, diag::err_duplicate_member) << II;
15547 Diag(PrevDecl->getLocation(), diag::note_previous_declaration);
15548 NewID->setInvalidDecl();
15552 // Process attributes attached to the ivar.
15553 ProcessDeclAttributes(S, NewID, D);
15555 if (D.isInvalidType())
15556 NewID->setInvalidDecl();
15558 // In ARC, infer 'retaining' for ivars of retainable type.
15559 if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(NewID))
15560 NewID->setInvalidDecl();
15562 if (D.getDeclSpec().isModulePrivateSpecified())
15563 NewID->setModulePrivate();
15566 // FIXME: When interfaces are DeclContexts, we'll need to add
15567 // these to the interface.
15569 IdResolver.AddDecl(NewID);
15572 if (LangOpts.ObjCRuntime.isNonFragile() &&
15573 !NewID->isInvalidDecl() && isa<ObjCInterfaceDecl>(EnclosingDecl))
15574 Diag(Loc, diag::warn_ivars_in_interface);
15579 /// ActOnLastBitfield - This routine handles synthesized bitfields rules for
15580 /// class and class extensions. For every class \@interface and class
15581 /// extension \@interface, if the last ivar is a bitfield of any type,
15582 /// then add an implicit `char :0` ivar to the end of that interface.
15583 void Sema::ActOnLastBitfield(SourceLocation DeclLoc,
15584 SmallVectorImpl<Decl *> &AllIvarDecls) {
15585 if (LangOpts.ObjCRuntime.isFragile() || AllIvarDecls.empty())
15588 Decl *ivarDecl = AllIvarDecls[AllIvarDecls.size()-1];
15589 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(ivarDecl);
15591 if (!Ivar->isBitField() || Ivar->isZeroLengthBitField(Context))
15593 ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CurContext);
15595 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(CurContext)) {
15596 if (!CD->IsClassExtension())
15599 // No need to add this to end of @implementation.
15603 // All conditions are met. Add a new bitfield to the tail end of ivars.
15604 llvm::APInt Zero(Context.getTypeSize(Context.IntTy), 0);
15605 Expr * BW = IntegerLiteral::Create(Context, Zero, Context.IntTy, DeclLoc);
15607 Ivar = ObjCIvarDecl::Create(Context, cast<ObjCContainerDecl>(CurContext),
15608 DeclLoc, DeclLoc, nullptr,
15610 Context.getTrivialTypeSourceInfo(Context.CharTy,
15612 ObjCIvarDecl::Private, BW,
15614 AllIvarDecls.push_back(Ivar);
15617 void Sema::ActOnFields(Scope *S, SourceLocation RecLoc, Decl *EnclosingDecl,
15618 ArrayRef<Decl *> Fields, SourceLocation LBrac,
15619 SourceLocation RBrac,
15620 const ParsedAttributesView &Attrs) {
15621 assert(EnclosingDecl && "missing record or interface decl");
15623 // If this is an Objective-C @implementation or category and we have
15624 // new fields here we should reset the layout of the interface since
15625 // it will now change.
15626 if (!Fields.empty() && isa<ObjCContainerDecl>(EnclosingDecl)) {
15627 ObjCContainerDecl *DC = cast<ObjCContainerDecl>(EnclosingDecl);
15628 switch (DC->getKind()) {
15630 case Decl::ObjCCategory:
15631 Context.ResetObjCLayout(cast<ObjCCategoryDecl>(DC)->getClassInterface());
15633 case Decl::ObjCImplementation:
15635 ResetObjCLayout(cast<ObjCImplementationDecl>(DC)->getClassInterface());
15640 RecordDecl *Record = dyn_cast<RecordDecl>(EnclosingDecl);
15642 // Start counting up the number of named members; make sure to include
15643 // members of anonymous structs and unions in the total.
15644 unsigned NumNamedMembers = 0;
15646 for (const auto *I : Record->decls()) {
15647 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(I))
15648 if (IFD->getDeclName())
15653 // Verify that all the fields are okay.
15654 SmallVector<FieldDecl*, 32> RecFields;
15656 bool ObjCFieldLifetimeErrReported = false;
15657 for (ArrayRef<Decl *>::iterator i = Fields.begin(), end = Fields.end();
15659 FieldDecl *FD = cast<FieldDecl>(*i);
15661 // Get the type for the field.
15662 const Type *FDTy = FD->getType().getTypePtr();
15664 if (!FD->isAnonymousStructOrUnion()) {
15665 // Remember all fields written by the user.
15666 RecFields.push_back(FD);
15669 // If the field is already invalid for some reason, don't emit more
15670 // diagnostics about it.
15671 if (FD->isInvalidDecl()) {
15672 EnclosingDecl->setInvalidDecl();
15677 // A structure or union shall not contain a member with
15678 // incomplete or function type (hence, a structure shall not
15679 // contain an instance of itself, but may contain a pointer to
15680 // an instance of itself), except that the last member of a
15681 // structure with more than one named member may have incomplete
15682 // array type; such a structure (and any union containing,
15683 // possibly recursively, a member that is such a structure)
15684 // shall not be a member of a structure or an element of an
15686 bool IsLastField = (i + 1 == Fields.end());
15687 if (FDTy->isFunctionType()) {
15688 // Field declared as a function.
15689 Diag(FD->getLocation(), diag::err_field_declared_as_function)
15690 << FD->getDeclName();
15691 FD->setInvalidDecl();
15692 EnclosingDecl->setInvalidDecl();
15694 } else if (FDTy->isIncompleteArrayType() &&
15695 (Record || isa<ObjCContainerDecl>(EnclosingDecl))) {
15697 // Flexible array member.
15698 // Microsoft and g++ is more permissive regarding flexible array.
15699 // It will accept flexible array in union and also
15700 // as the sole element of a struct/class.
15701 unsigned DiagID = 0;
15702 if (!Record->isUnion() && !IsLastField) {
15703 Diag(FD->getLocation(), diag::err_flexible_array_not_at_end)
15704 << FD->getDeclName() << FD->getType() << Record->getTagKind();
15705 Diag((*(i + 1))->getLocation(), diag::note_next_field_declaration);
15706 FD->setInvalidDecl();
15707 EnclosingDecl->setInvalidDecl();
15709 } else if (Record->isUnion())
15710 DiagID = getLangOpts().MicrosoftExt
15711 ? diag::ext_flexible_array_union_ms
15712 : getLangOpts().CPlusPlus
15713 ? diag::ext_flexible_array_union_gnu
15714 : diag::err_flexible_array_union;
15715 else if (NumNamedMembers < 1)
15716 DiagID = getLangOpts().MicrosoftExt
15717 ? diag::ext_flexible_array_empty_aggregate_ms
15718 : getLangOpts().CPlusPlus
15719 ? diag::ext_flexible_array_empty_aggregate_gnu
15720 : diag::err_flexible_array_empty_aggregate;
15723 Diag(FD->getLocation(), DiagID) << FD->getDeclName()
15724 << Record->getTagKind();
15725 // While the layout of types that contain virtual bases is not specified
15726 // by the C++ standard, both the Itanium and Microsoft C++ ABIs place
15727 // virtual bases after the derived members. This would make a flexible
15728 // array member declared at the end of an object not adjacent to the end
15730 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Record))
15731 if (RD->getNumVBases() != 0)
15732 Diag(FD->getLocation(), diag::err_flexible_array_virtual_base)
15733 << FD->getDeclName() << Record->getTagKind();
15734 if (!getLangOpts().C99)
15735 Diag(FD->getLocation(), diag::ext_c99_flexible_array_member)
15736 << FD->getDeclName() << Record->getTagKind();
15738 // If the element type has a non-trivial destructor, we would not
15739 // implicitly destroy the elements, so disallow it for now.
15741 // FIXME: GCC allows this. We should probably either implicitly delete
15742 // the destructor of the containing class, or just allow this.
15743 QualType BaseElem = Context.getBaseElementType(FD->getType());
15744 if (!BaseElem->isDependentType() && BaseElem.isDestructedType()) {
15745 Diag(FD->getLocation(), diag::err_flexible_array_has_nontrivial_dtor)
15746 << FD->getDeclName() << FD->getType();
15747 FD->setInvalidDecl();
15748 EnclosingDecl->setInvalidDecl();
15751 // Okay, we have a legal flexible array member at the end of the struct.
15752 Record->setHasFlexibleArrayMember(true);
15754 // In ObjCContainerDecl ivars with incomplete array type are accepted,
15755 // unless they are followed by another ivar. That check is done
15756 // elsewhere, after synthesized ivars are known.
15758 } else if (!FDTy->isDependentType() &&
15759 RequireCompleteType(FD->getLocation(), FD->getType(),
15760 diag::err_field_incomplete)) {
15762 FD->setInvalidDecl();
15763 EnclosingDecl->setInvalidDecl();
15765 } else if (const RecordType *FDTTy = FDTy->getAs<RecordType>()) {
15766 if (Record && FDTTy->getDecl()->hasFlexibleArrayMember()) {
15767 // A type which contains a flexible array member is considered to be a
15768 // flexible array member.
15769 Record->setHasFlexibleArrayMember(true);
15770 if (!Record->isUnion()) {
15771 // If this is a struct/class and this is not the last element, reject
15772 // it. Note that GCC supports variable sized arrays in the middle of
15775 Diag(FD->getLocation(), diag::ext_variable_sized_type_in_struct)
15776 << FD->getDeclName() << FD->getType();
15778 // We support flexible arrays at the end of structs in
15779 // other structs as an extension.
15780 Diag(FD->getLocation(), diag::ext_flexible_array_in_struct)
15781 << FD->getDeclName();
15785 if (isa<ObjCContainerDecl>(EnclosingDecl) &&
15786 RequireNonAbstractType(FD->getLocation(), FD->getType(),
15787 diag::err_abstract_type_in_decl,
15788 AbstractIvarType)) {
15789 // Ivars can not have abstract class types
15790 FD->setInvalidDecl();
15792 if (Record && FDTTy->getDecl()->hasObjectMember())
15793 Record->setHasObjectMember(true);
15794 if (Record && FDTTy->getDecl()->hasVolatileMember())
15795 Record->setHasVolatileMember(true);
15796 } else if (FDTy->isObjCObjectType()) {
15797 /// A field cannot be an Objective-c object
15798 Diag(FD->getLocation(), diag::err_statically_allocated_object)
15799 << FixItHint::CreateInsertion(FD->getLocation(), "*");
15800 QualType T = Context.getObjCObjectPointerType(FD->getType());
15802 } else if (getLangOpts().allowsNonTrivialObjCLifetimeQualifiers() &&
15803 Record && !ObjCFieldLifetimeErrReported && Record->isUnion()) {
15804 // It's an error in ARC or Weak if a field has lifetime.
15805 // We don't want to report this in a system header, though,
15806 // so we just make the field unavailable.
15807 // FIXME: that's really not sufficient; we need to make the type
15808 // itself invalid to, say, initialize or copy.
15809 QualType T = FD->getType();
15810 if (T.hasNonTrivialObjCLifetime()) {
15811 SourceLocation loc = FD->getLocation();
15812 if (getSourceManager().isInSystemHeader(loc)) {
15813 if (!FD->hasAttr<UnavailableAttr>()) {
15814 FD->addAttr(UnavailableAttr::CreateImplicit(Context, "",
15815 UnavailableAttr::IR_ARCFieldWithOwnership, loc));
15818 Diag(FD->getLocation(), diag::err_arc_objc_object_in_tag)
15819 << T->isBlockPointerType() << Record->getTagKind();
15821 ObjCFieldLifetimeErrReported = true;
15823 } else if (getLangOpts().ObjC1 &&
15824 getLangOpts().getGC() != LangOptions::NonGC &&
15825 Record && !Record->hasObjectMember()) {
15826 if (FD->getType()->isObjCObjectPointerType() ||
15827 FD->getType().isObjCGCStrong())
15828 Record->setHasObjectMember(true);
15829 else if (Context.getAsArrayType(FD->getType())) {
15830 QualType BaseType = Context.getBaseElementType(FD->getType());
15831 if (BaseType->isRecordType() &&
15832 BaseType->getAs<RecordType>()->getDecl()->hasObjectMember())
15833 Record->setHasObjectMember(true);
15834 else if (BaseType->isObjCObjectPointerType() ||
15835 BaseType.isObjCGCStrong())
15836 Record->setHasObjectMember(true);
15840 if (Record && !getLangOpts().CPlusPlus && !FD->hasAttr<UnavailableAttr>()) {
15841 QualType FT = FD->getType();
15842 if (FT.isNonTrivialToPrimitiveDefaultInitialize())
15843 Record->setNonTrivialToPrimitiveDefaultInitialize(true);
15844 QualType::PrimitiveCopyKind PCK = FT.isNonTrivialToPrimitiveCopy();
15845 if (PCK != QualType::PCK_Trivial && PCK != QualType::PCK_VolatileTrivial)
15846 Record->setNonTrivialToPrimitiveCopy(true);
15847 if (FT.isDestructedType()) {
15848 Record->setNonTrivialToPrimitiveDestroy(true);
15849 Record->setParamDestroyedInCallee(true);
15852 if (const auto *RT = FT->getAs<RecordType>()) {
15853 if (RT->getDecl()->getArgPassingRestrictions() ==
15854 RecordDecl::APK_CanNeverPassInRegs)
15855 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
15856 } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak)
15857 Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
15860 if (Record && FD->getType().isVolatileQualified())
15861 Record->setHasVolatileMember(true);
15862 // Keep track of the number of named members.
15863 if (FD->getIdentifier())
15867 // Okay, we successfully defined 'Record'.
15869 bool Completed = false;
15870 if (CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(Record)) {
15871 if (!CXXRecord->isInvalidDecl()) {
15872 // Set access bits correctly on the directly-declared conversions.
15873 for (CXXRecordDecl::conversion_iterator
15874 I = CXXRecord->conversion_begin(),
15875 E = CXXRecord->conversion_end(); I != E; ++I)
15876 I.setAccess((*I)->getAccess());
15879 if (!CXXRecord->isDependentType()) {
15880 if (CXXRecord->hasUserDeclaredDestructor()) {
15881 // Adjust user-defined destructor exception spec.
15882 if (getLangOpts().CPlusPlus11)
15883 AdjustDestructorExceptionSpec(CXXRecord,
15884 CXXRecord->getDestructor());
15887 // Add any implicitly-declared members to this class.
15888 AddImplicitlyDeclaredMembersToClass(CXXRecord);
15890 if (!CXXRecord->isInvalidDecl()) {
15891 // If we have virtual base classes, we may end up finding multiple
15892 // final overriders for a given virtual function. Check for this
15894 if (CXXRecord->getNumVBases()) {
15895 CXXFinalOverriderMap FinalOverriders;
15896 CXXRecord->getFinalOverriders(FinalOverriders);
15898 for (CXXFinalOverriderMap::iterator M = FinalOverriders.begin(),
15899 MEnd = FinalOverriders.end();
15901 for (OverridingMethods::iterator SO = M->second.begin(),
15902 SOEnd = M->second.end();
15903 SO != SOEnd; ++SO) {
15904 assert(SO->second.size() > 0 &&
15905 "Virtual function without overriding functions?");
15906 if (SO->second.size() == 1)
15909 // C++ [class.virtual]p2:
15910 // In a derived class, if a virtual member function of a base
15911 // class subobject has more than one final overrider the
15912 // program is ill-formed.
15913 Diag(Record->getLocation(), diag::err_multiple_final_overriders)
15914 << (const NamedDecl *)M->first << Record;
15915 Diag(M->first->getLocation(),
15916 diag::note_overridden_virtual_function);
15917 for (OverridingMethods::overriding_iterator
15918 OM = SO->second.begin(),
15919 OMEnd = SO->second.end();
15921 Diag(OM->Method->getLocation(), diag::note_final_overrider)
15922 << (const NamedDecl *)M->first << OM->Method->getParent();
15924 Record->setInvalidDecl();
15927 CXXRecord->completeDefinition(&FinalOverriders);
15935 Record->completeDefinition();
15937 // Handle attributes before checking the layout.
15938 ProcessDeclAttributeList(S, Record, Attrs);
15940 // We may have deferred checking for a deleted destructor. Check now.
15941 if (CXXRecordDecl *CXXRecord = dyn_cast<CXXRecordDecl>(Record)) {
15942 auto *Dtor = CXXRecord->getDestructor();
15943 if (Dtor && Dtor->isImplicit() &&
15944 ShouldDeleteSpecialMember(Dtor, CXXDestructor)) {
15945 CXXRecord->setImplicitDestructorIsDeleted();
15946 SetDeclDeleted(Dtor, CXXRecord->getLocation());
15950 if (Record->hasAttrs()) {
15951 CheckAlignasUnderalignment(Record);
15953 if (const MSInheritanceAttr *IA = Record->getAttr<MSInheritanceAttr>())
15954 checkMSInheritanceAttrOnDefinition(cast<CXXRecordDecl>(Record),
15955 IA->getRange(), IA->getBestCase(),
15956 IA->getSemanticSpelling());
15959 // Check if the structure/union declaration is a type that can have zero
15960 // size in C. For C this is a language extension, for C++ it may cause
15961 // compatibility problems.
15962 bool CheckForZeroSize;
15963 if (!getLangOpts().CPlusPlus) {
15964 CheckForZeroSize = true;
15966 // For C++ filter out types that cannot be referenced in C code.
15967 CXXRecordDecl *CXXRecord = cast<CXXRecordDecl>(Record);
15969 CXXRecord->getLexicalDeclContext()->isExternCContext() &&
15970 !CXXRecord->isDependentType() &&
15971 CXXRecord->isCLike();
15973 if (CheckForZeroSize) {
15974 bool ZeroSize = true;
15975 bool IsEmpty = true;
15976 unsigned NonBitFields = 0;
15977 for (RecordDecl::field_iterator I = Record->field_begin(),
15978 E = Record->field_end();
15979 (NonBitFields == 0 || ZeroSize) && I != E; ++I) {
15981 if (I->isUnnamedBitfield()) {
15982 if (!I->isZeroLengthBitField(Context))
15986 QualType FieldType = I->getType();
15987 if (FieldType->isIncompleteType() ||
15988 !Context.getTypeSizeInChars(FieldType).isZero())
15993 // Empty structs are an extension in C (C99 6.7.2.1p7). They are
15994 // allowed in C++, but warn if its declaration is inside
15995 // extern "C" block.
15997 Diag(RecLoc, getLangOpts().CPlusPlus ?
15998 diag::warn_zero_size_struct_union_in_extern_c :
15999 diag::warn_zero_size_struct_union_compat)
16000 << IsEmpty << Record->isUnion() << (NonBitFields > 1);
16003 // Structs without named members are extension in C (C99 6.7.2.1p7),
16004 // but are accepted by GCC.
16005 if (NonBitFields == 0 && !getLangOpts().CPlusPlus) {
16006 Diag(RecLoc, IsEmpty ? diag::ext_empty_struct_union :
16007 diag::ext_no_named_members_in_struct_union)
16008 << Record->isUnion();
16012 ObjCIvarDecl **ClsFields =
16013 reinterpret_cast<ObjCIvarDecl**>(RecFields.data());
16014 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(EnclosingDecl)) {
16015 ID->setEndOfDefinitionLoc(RBrac);
16016 // Add ivar's to class's DeclContext.
16017 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
16018 ClsFields[i]->setLexicalDeclContext(ID);
16019 ID->addDecl(ClsFields[i]);
16021 // Must enforce the rule that ivars in the base classes may not be
16023 if (ID->getSuperClass())
16024 DiagnoseDuplicateIvars(ID, ID->getSuperClass());
16025 } else if (ObjCImplementationDecl *IMPDecl =
16026 dyn_cast<ObjCImplementationDecl>(EnclosingDecl)) {
16027 assert(IMPDecl && "ActOnFields - missing ObjCImplementationDecl");
16028 for (unsigned I = 0, N = RecFields.size(); I != N; ++I)
16029 // Ivar declared in @implementation never belongs to the implementation.
16030 // Only it is in implementation's lexical context.
16031 ClsFields[I]->setLexicalDeclContext(IMPDecl);
16032 CheckImplementationIvars(IMPDecl, ClsFields, RecFields.size(), RBrac);
16033 IMPDecl->setIvarLBraceLoc(LBrac);
16034 IMPDecl->setIvarRBraceLoc(RBrac);
16035 } else if (ObjCCategoryDecl *CDecl =
16036 dyn_cast<ObjCCategoryDecl>(EnclosingDecl)) {
16037 // case of ivars in class extension; all other cases have been
16038 // reported as errors elsewhere.
16039 // FIXME. Class extension does not have a LocEnd field.
16040 // CDecl->setLocEnd(RBrac);
16041 // Add ivar's to class extension's DeclContext.
16042 // Diagnose redeclaration of private ivars.
16043 ObjCInterfaceDecl *IDecl = CDecl->getClassInterface();
16044 for (unsigned i = 0, e = RecFields.size(); i != e; ++i) {
16046 if (const ObjCIvarDecl *ClsIvar =
16047 IDecl->getIvarDecl(ClsFields[i]->getIdentifier())) {
16048 Diag(ClsFields[i]->getLocation(),
16049 diag::err_duplicate_ivar_declaration);
16050 Diag(ClsIvar->getLocation(), diag::note_previous_definition);
16053 for (const auto *Ext : IDecl->known_extensions()) {
16054 if (const ObjCIvarDecl *ClsExtIvar
16055 = Ext->getIvarDecl(ClsFields[i]->getIdentifier())) {
16056 Diag(ClsFields[i]->getLocation(),
16057 diag::err_duplicate_ivar_declaration);
16058 Diag(ClsExtIvar->getLocation(), diag::note_previous_definition);
16063 ClsFields[i]->setLexicalDeclContext(CDecl);
16064 CDecl->addDecl(ClsFields[i]);
16066 CDecl->setIvarLBraceLoc(LBrac);
16067 CDecl->setIvarRBraceLoc(RBrac);
16072 /// Determine whether the given integral value is representable within
16073 /// the given type T.
16074 static bool isRepresentableIntegerValue(ASTContext &Context,
16075 llvm::APSInt &Value,
16077 assert((T->isIntegralType(Context) || T->isEnumeralType()) &&
16078 "Integral type required!");
16079 unsigned BitWidth = Context.getIntWidth(T);
16081 if (Value.isUnsigned() || Value.isNonNegative()) {
16082 if (T->isSignedIntegerOrEnumerationType())
16084 return Value.getActiveBits() <= BitWidth;
16086 return Value.getMinSignedBits() <= BitWidth;
16089 // Given an integral type, return the next larger integral type
16090 // (or a NULL type of no such type exists).
16091 static QualType getNextLargerIntegralType(ASTContext &Context, QualType T) {
16092 // FIXME: Int128/UInt128 support, which also needs to be introduced into
16093 // enum checking below.
16094 assert((T->isIntegralType(Context) ||
16095 T->isEnumeralType()) && "Integral type required!");
16096 const unsigned NumTypes = 4;
16097 QualType SignedIntegralTypes[NumTypes] = {
16098 Context.ShortTy, Context.IntTy, Context.LongTy, Context.LongLongTy
16100 QualType UnsignedIntegralTypes[NumTypes] = {
16101 Context.UnsignedShortTy, Context.UnsignedIntTy, Context.UnsignedLongTy,
16102 Context.UnsignedLongLongTy
16105 unsigned BitWidth = Context.getTypeSize(T);
16106 QualType *Types = T->isSignedIntegerOrEnumerationType()? SignedIntegralTypes
16107 : UnsignedIntegralTypes;
16108 for (unsigned I = 0; I != NumTypes; ++I)
16109 if (Context.getTypeSize(Types[I]) > BitWidth)
16115 EnumConstantDecl *Sema::CheckEnumConstant(EnumDecl *Enum,
16116 EnumConstantDecl *LastEnumConst,
16117 SourceLocation IdLoc,
16118 IdentifierInfo *Id,
16120 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
16121 llvm::APSInt EnumVal(IntWidth);
16124 if (Val && DiagnoseUnexpandedParameterPack(Val, UPPC_EnumeratorValue))
16128 Val = DefaultLvalueConversion(Val).get();
16131 if (Enum->isDependentType() || Val->isTypeDependent())
16132 EltTy = Context.DependentTy;
16134 if (getLangOpts().CPlusPlus11 && Enum->isFixed() &&
16135 !getLangOpts().MSVCCompat) {
16136 // C++11 [dcl.enum]p5: If the underlying type is fixed, [...] the
16137 // constant-expression in the enumerator-definition shall be a converted
16138 // constant expression of the underlying type.
16139 EltTy = Enum->getIntegerType();
16140 ExprResult Converted =
16141 CheckConvertedConstantExpression(Val, EltTy, EnumVal,
16143 if (Converted.isInvalid())
16146 Val = Converted.get();
16147 } else if (!Val->isValueDependent() &&
16148 !(Val = VerifyIntegerConstantExpression(Val,
16149 &EnumVal).get())) {
16150 // C99 6.7.2.2p2: Make sure we have an integer constant expression.
16152 if (Enum->isComplete()) {
16153 EltTy = Enum->getIntegerType();
16155 // In Obj-C and Microsoft mode, require the enumeration value to be
16156 // representable in the underlying type of the enumeration. In C++11,
16157 // we perform a non-narrowing conversion as part of converted constant
16158 // expression checking.
16159 if (!isRepresentableIntegerValue(Context, EnumVal, EltTy)) {
16160 if (getLangOpts().MSVCCompat) {
16161 Diag(IdLoc, diag::ext_enumerator_too_large) << EltTy;
16162 Val = ImpCastExprToType(Val, EltTy, CK_IntegralCast).get();
16164 Diag(IdLoc, diag::err_enumerator_too_large) << EltTy;
16166 Val = ImpCastExprToType(Val, EltTy,
16167 EltTy->isBooleanType() ?
16168 CK_IntegralToBoolean : CK_IntegralCast)
16170 } else if (getLangOpts().CPlusPlus) {
16171 // C++11 [dcl.enum]p5:
16172 // If the underlying type is not fixed, the type of each enumerator
16173 // is the type of its initializing value:
16174 // - If an initializer is specified for an enumerator, the
16175 // initializing value has the same type as the expression.
16176 EltTy = Val->getType();
16179 // The expression that defines the value of an enumeration constant
16180 // shall be an integer constant expression that has a value
16181 // representable as an int.
16183 // Complain if the value is not representable in an int.
16184 if (!isRepresentableIntegerValue(Context, EnumVal, Context.IntTy))
16185 Diag(IdLoc, diag::ext_enum_value_not_int)
16186 << EnumVal.toString(10) << Val->getSourceRange()
16187 << (EnumVal.isUnsigned() || EnumVal.isNonNegative());
16188 else if (!Context.hasSameType(Val->getType(), Context.IntTy)) {
16189 // Force the type of the expression to 'int'.
16190 Val = ImpCastExprToType(Val, Context.IntTy, CK_IntegralCast).get();
16192 EltTy = Val->getType();
16199 if (Enum->isDependentType())
16200 EltTy = Context.DependentTy;
16201 else if (!LastEnumConst) {
16202 // C++0x [dcl.enum]p5:
16203 // If the underlying type is not fixed, the type of each enumerator
16204 // is the type of its initializing value:
16205 // - If no initializer is specified for the first enumerator, the
16206 // initializing value has an unspecified integral type.
16208 // GCC uses 'int' for its unspecified integral type, as does
16210 if (Enum->isFixed()) {
16211 EltTy = Enum->getIntegerType();
16214 EltTy = Context.IntTy;
16217 // Assign the last value + 1.
16218 EnumVal = LastEnumConst->getInitVal();
16220 EltTy = LastEnumConst->getType();
16222 // Check for overflow on increment.
16223 if (EnumVal < LastEnumConst->getInitVal()) {
16224 // C++0x [dcl.enum]p5:
16225 // If the underlying type is not fixed, the type of each enumerator
16226 // is the type of its initializing value:
16228 // - Otherwise the type of the initializing value is the same as
16229 // the type of the initializing value of the preceding enumerator
16230 // unless the incremented value is not representable in that type,
16231 // in which case the type is an unspecified integral type
16232 // sufficient to contain the incremented value. If no such type
16233 // exists, the program is ill-formed.
16234 QualType T = getNextLargerIntegralType(Context, EltTy);
16235 if (T.isNull() || Enum->isFixed()) {
16236 // There is no integral type larger enough to represent this
16237 // value. Complain, then allow the value to wrap around.
16238 EnumVal = LastEnumConst->getInitVal();
16239 EnumVal = EnumVal.zext(EnumVal.getBitWidth() * 2);
16241 if (Enum->isFixed())
16242 // When the underlying type is fixed, this is ill-formed.
16243 Diag(IdLoc, diag::err_enumerator_wrapped)
16244 << EnumVal.toString(10)
16247 Diag(IdLoc, diag::ext_enumerator_increment_too_large)
16248 << EnumVal.toString(10);
16253 // Retrieve the last enumerator's value, extent that type to the
16254 // type that is supposed to be large enough to represent the incremented
16255 // value, then increment.
16256 EnumVal = LastEnumConst->getInitVal();
16257 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
16258 EnumVal = EnumVal.zextOrTrunc(Context.getIntWidth(EltTy));
16261 // If we're not in C++, diagnose the overflow of enumerator values,
16262 // which in C99 means that the enumerator value is not representable in
16263 // an int (C99 6.7.2.2p2). However, we support GCC's extension that
16264 // permits enumerator values that are representable in some larger
16266 if (!getLangOpts().CPlusPlus && !T.isNull())
16267 Diag(IdLoc, diag::warn_enum_value_overflow);
16268 } else if (!getLangOpts().CPlusPlus &&
16269 !isRepresentableIntegerValue(Context, EnumVal, EltTy)) {
16270 // Enforce C99 6.7.2.2p2 even when we compute the next value.
16271 Diag(IdLoc, diag::ext_enum_value_not_int)
16272 << EnumVal.toString(10) << 1;
16277 if (!EltTy->isDependentType()) {
16278 // Make the enumerator value match the signedness and size of the
16279 // enumerator's type.
16280 EnumVal = EnumVal.extOrTrunc(Context.getIntWidth(EltTy));
16281 EnumVal.setIsSigned(EltTy->isSignedIntegerOrEnumerationType());
16284 return EnumConstantDecl::Create(Context, Enum, IdLoc, Id, EltTy,
16288 Sema::SkipBodyInfo Sema::shouldSkipAnonEnumBody(Scope *S, IdentifierInfo *II,
16289 SourceLocation IILoc) {
16290 if (!(getLangOpts().Modules || getLangOpts().ModulesLocalVisibility) ||
16291 !getLangOpts().CPlusPlus)
16292 return SkipBodyInfo();
16294 // We have an anonymous enum definition. Look up the first enumerator to
16295 // determine if we should merge the definition with an existing one and
16297 NamedDecl *PrevDecl = LookupSingleName(S, II, IILoc, LookupOrdinaryName,
16298 forRedeclarationInCurContext());
16299 auto *PrevECD = dyn_cast_or_null<EnumConstantDecl>(PrevDecl);
16301 return SkipBodyInfo();
16303 EnumDecl *PrevED = cast<EnumDecl>(PrevECD->getDeclContext());
16305 if (!PrevED->getDeclName() && !hasVisibleDefinition(PrevED, &Hidden)) {
16307 Skip.Previous = Hidden;
16311 return SkipBodyInfo();
16314 Decl *Sema::ActOnEnumConstant(Scope *S, Decl *theEnumDecl, Decl *lastEnumConst,
16315 SourceLocation IdLoc, IdentifierInfo *Id,
16316 const ParsedAttributesView &Attrs,
16317 SourceLocation EqualLoc, Expr *Val) {
16318 EnumDecl *TheEnumDecl = cast<EnumDecl>(theEnumDecl);
16319 EnumConstantDecl *LastEnumConst =
16320 cast_or_null<EnumConstantDecl>(lastEnumConst);
16322 // The scope passed in may not be a decl scope. Zip up the scope tree until
16323 // we find one that is.
16324 S = getNonFieldDeclScope(S);
16326 // Verify that there isn't already something declared with this name in this
16328 NamedDecl *PrevDecl = LookupSingleName(S, Id, IdLoc, LookupOrdinaryName,
16329 ForVisibleRedeclaration);
16330 if (PrevDecl && PrevDecl->isTemplateParameter()) {
16331 // Maybe we will complain about the shadowed template parameter.
16332 DiagnoseTemplateParameterShadow(IdLoc, PrevDecl);
16333 // Just pretend that we didn't see the previous declaration.
16334 PrevDecl = nullptr;
16337 // C++ [class.mem]p15:
16338 // If T is the name of a class, then each of the following shall have a name
16339 // different from T:
16340 // - every enumerator of every member of class T that is an unscoped
16342 if (getLangOpts().CPlusPlus && !TheEnumDecl->isScoped())
16343 DiagnoseClassNameShadow(TheEnumDecl->getDeclContext(),
16344 DeclarationNameInfo(Id, IdLoc));
16346 EnumConstantDecl *New =
16347 CheckEnumConstant(TheEnumDecl, LastEnumConst, IdLoc, Id, Val);
16352 // When in C++, we may get a TagDecl with the same name; in this case the
16353 // enum constant will 'hide' the tag.
16354 assert((getLangOpts().CPlusPlus || !isa<TagDecl>(PrevDecl)) &&
16355 "Received TagDecl when not in C++!");
16356 if (!isa<TagDecl>(PrevDecl) && isDeclInScope(PrevDecl, CurContext, S)) {
16357 if (isa<EnumConstantDecl>(PrevDecl))
16358 Diag(IdLoc, diag::err_redefinition_of_enumerator) << Id;
16360 Diag(IdLoc, diag::err_redefinition) << Id;
16361 notePreviousDefinition(PrevDecl, IdLoc);
16366 // Process attributes.
16367 ProcessDeclAttributeList(S, New, Attrs);
16368 AddPragmaAttributes(S, New);
16370 // Register this decl in the current scope stack.
16371 New->setAccess(TheEnumDecl->getAccess());
16372 PushOnScopeChains(New, S);
16374 ActOnDocumentableDecl(New);
16379 // Returns true when the enum initial expression does not trigger the
16380 // duplicate enum warning. A few common cases are exempted as follows:
16381 // Element2 = Element1
16382 // Element2 = Element1 + 1
16383 // Element2 = Element1 - 1
16384 // Where Element2 and Element1 are from the same enum.
16385 static bool ValidDuplicateEnum(EnumConstantDecl *ECD, EnumDecl *Enum) {
16386 Expr *InitExpr = ECD->getInitExpr();
16389 InitExpr = InitExpr->IgnoreImpCasts();
16391 if (BinaryOperator *BO = dyn_cast<BinaryOperator>(InitExpr)) {
16392 if (!BO->isAdditiveOp())
16394 IntegerLiteral *IL = dyn_cast<IntegerLiteral>(BO->getRHS());
16397 if (IL->getValue() != 1)
16400 InitExpr = BO->getLHS();
16403 // This checks if the elements are from the same enum.
16404 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(InitExpr);
16408 EnumConstantDecl *EnumConstant = dyn_cast<EnumConstantDecl>(DRE->getDecl());
16412 if (cast<EnumDecl>(TagDecl::castFromDeclContext(ECD->getDeclContext())) !=
16419 // Emits a warning when an element is implicitly set a value that
16420 // a previous element has already been set to.
16421 static void CheckForDuplicateEnumValues(Sema &S, ArrayRef<Decl *> Elements,
16422 EnumDecl *Enum, QualType EnumType) {
16423 // Avoid anonymous enums
16424 if (!Enum->getIdentifier())
16427 // Only check for small enums.
16428 if (Enum->getNumPositiveBits() > 63 || Enum->getNumNegativeBits() > 64)
16431 if (S.Diags.isIgnored(diag::warn_duplicate_enum_values, Enum->getLocation()))
16434 typedef SmallVector<EnumConstantDecl *, 3> ECDVector;
16435 typedef SmallVector<std::unique_ptr<ECDVector>, 3> DuplicatesVector;
16437 typedef llvm::PointerUnion<EnumConstantDecl*, ECDVector*> DeclOrVector;
16438 typedef llvm::DenseMap<int64_t, DeclOrVector> ValueToVectorMap;
16440 // Use int64_t as a key to avoid needing special handling for DenseMap keys.
16441 auto EnumConstantToKey = [](const EnumConstantDecl *D) {
16442 llvm::APSInt Val = D->getInitVal();
16443 return Val.isSigned() ? Val.getSExtValue() : Val.getZExtValue();
16446 DuplicatesVector DupVector;
16447 ValueToVectorMap EnumMap;
16449 // Populate the EnumMap with all values represented by enum constants without
16451 for (auto *Element : Elements) {
16452 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(Element);
16454 // Null EnumConstantDecl means a previous diagnostic has been emitted for
16455 // this constant. Skip this enum since it may be ill-formed.
16460 // Constants with initalizers are handled in the next loop.
16461 if (ECD->getInitExpr())
16464 // Duplicate values are handled in the next loop.
16465 EnumMap.insert({EnumConstantToKey(ECD), ECD});
16468 if (EnumMap.size() == 0)
16471 // Create vectors for any values that has duplicates.
16472 for (auto *Element : Elements) {
16473 // The last loop returned if any constant was null.
16474 EnumConstantDecl *ECD = cast<EnumConstantDecl>(Element);
16475 if (!ValidDuplicateEnum(ECD, Enum))
16478 auto Iter = EnumMap.find(EnumConstantToKey(ECD));
16479 if (Iter == EnumMap.end())
16482 DeclOrVector& Entry = Iter->second;
16483 if (EnumConstantDecl *D = Entry.dyn_cast<EnumConstantDecl*>()) {
16484 // Ensure constants are different.
16488 // Create new vector and push values onto it.
16489 auto Vec = llvm::make_unique<ECDVector>();
16491 Vec->push_back(ECD);
16493 // Update entry to point to the duplicates vector.
16496 // Store the vector somewhere we can consult later for quick emission of
16498 DupVector.emplace_back(std::move(Vec));
16502 ECDVector *Vec = Entry.get<ECDVector*>();
16503 // Make sure constants are not added more than once.
16504 if (*Vec->begin() == ECD)
16507 Vec->push_back(ECD);
16510 // Emit diagnostics.
16511 for (const auto &Vec : DupVector) {
16512 assert(Vec->size() > 1 && "ECDVector should have at least 2 elements.");
16514 // Emit warning for one enum constant.
16515 auto *FirstECD = Vec->front();
16516 S.Diag(FirstECD->getLocation(), diag::warn_duplicate_enum_values)
16517 << FirstECD << FirstECD->getInitVal().toString(10)
16518 << FirstECD->getSourceRange();
16520 // Emit one note for each of the remaining enum constants with
16522 for (auto *ECD : llvm::make_range(Vec->begin() + 1, Vec->end()))
16523 S.Diag(ECD->getLocation(), diag::note_duplicate_element)
16524 << ECD << ECD->getInitVal().toString(10)
16525 << ECD->getSourceRange();
16529 bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
16530 bool AllowMask) const {
16531 assert(ED->isClosedFlag() && "looking for value in non-flag or open enum");
16532 assert(ED->isCompleteDefinition() && "expected enum definition");
16534 auto R = FlagBitsCache.insert(std::make_pair(ED, llvm::APInt()));
16535 llvm::APInt &FlagBits = R.first->second;
16538 for (auto *E : ED->enumerators()) {
16539 const auto &EVal = E->getInitVal();
16540 // Only single-bit enumerators introduce new flag values.
16541 if (EVal.isPowerOf2())
16542 FlagBits = FlagBits.zextOrSelf(EVal.getBitWidth()) | EVal;
16546 // A value is in a flag enum if either its bits are a subset of the enum's
16547 // flag bits (the first condition) or we are allowing masks and the same is
16548 // true of its complement (the second condition). When masks are allowed, we
16549 // allow the common idiom of ~(enum1 | enum2) to be a valid enum value.
16551 // While it's true that any value could be used as a mask, the assumption is
16552 // that a mask will have all of the insignificant bits set. Anything else is
16553 // likely a logic error.
16554 llvm::APInt FlagMask = ~FlagBits.zextOrTrunc(Val.getBitWidth());
16555 return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
16558 void Sema::ActOnEnumBody(SourceLocation EnumLoc, SourceRange BraceRange,
16559 Decl *EnumDeclX, ArrayRef<Decl *> Elements, Scope *S,
16560 const ParsedAttributesView &Attrs) {
16561 EnumDecl *Enum = cast<EnumDecl>(EnumDeclX);
16562 QualType EnumType = Context.getTypeDeclType(Enum);
16564 ProcessDeclAttributeList(S, Enum, Attrs);
16566 if (Enum->isDependentType()) {
16567 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
16568 EnumConstantDecl *ECD =
16569 cast_or_null<EnumConstantDecl>(Elements[i]);
16570 if (!ECD) continue;
16572 ECD->setType(EnumType);
16575 Enum->completeDefinition(Context.DependentTy, Context.DependentTy, 0, 0);
16579 // TODO: If the result value doesn't fit in an int, it must be a long or long
16580 // long value. ISO C does not support this, but GCC does as an extension,
16582 unsigned IntWidth = Context.getTargetInfo().getIntWidth();
16583 unsigned CharWidth = Context.getTargetInfo().getCharWidth();
16584 unsigned ShortWidth = Context.getTargetInfo().getShortWidth();
16586 // Verify that all the values are okay, compute the size of the values, and
16587 // reverse the list.
16588 unsigned NumNegativeBits = 0;
16589 unsigned NumPositiveBits = 0;
16591 // Keep track of whether all elements have type int.
16592 bool AllElementsInt = true;
16594 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
16595 EnumConstantDecl *ECD =
16596 cast_or_null<EnumConstantDecl>(Elements[i]);
16597 if (!ECD) continue; // Already issued a diagnostic.
16599 const llvm::APSInt &InitVal = ECD->getInitVal();
16601 // Keep track of the size of positive and negative values.
16602 if (InitVal.isUnsigned() || InitVal.isNonNegative())
16603 NumPositiveBits = std::max(NumPositiveBits,
16604 (unsigned)InitVal.getActiveBits());
16606 NumNegativeBits = std::max(NumNegativeBits,
16607 (unsigned)InitVal.getMinSignedBits());
16609 // Keep track of whether every enum element has type int (very commmon).
16610 if (AllElementsInt)
16611 AllElementsInt = ECD->getType() == Context.IntTy;
16614 // Figure out the type that should be used for this enum.
16616 unsigned BestWidth;
16618 // C++0x N3000 [conv.prom]p3:
16619 // An rvalue of an unscoped enumeration type whose underlying
16620 // type is not fixed can be converted to an rvalue of the first
16621 // of the following types that can represent all the values of
16622 // the enumeration: int, unsigned int, long int, unsigned long
16623 // int, long long int, or unsigned long long int.
16625 // An identifier declared as an enumeration constant has type int.
16626 // The C99 rule is modified by a gcc extension
16627 QualType BestPromotionType;
16629 bool Packed = Enum->hasAttr<PackedAttr>();
16630 // -fshort-enums is the equivalent to specifying the packed attribute on all
16631 // enum definitions.
16632 if (LangOpts.ShortEnums)
16635 // If the enum already has a type because it is fixed or dictated by the
16636 // target, promote that type instead of analyzing the enumerators.
16637 if (Enum->isComplete()) {
16638 BestType = Enum->getIntegerType();
16639 if (BestType->isPromotableIntegerType())
16640 BestPromotionType = Context.getPromotedIntegerType(BestType);
16642 BestPromotionType = BestType;
16644 BestWidth = Context.getIntWidth(BestType);
16646 else if (NumNegativeBits) {
16647 // If there is a negative value, figure out the smallest integer type (of
16648 // int/long/longlong) that fits.
16649 // If it's packed, check also if it fits a char or a short.
16650 if (Packed && NumNegativeBits <= CharWidth && NumPositiveBits < CharWidth) {
16651 BestType = Context.SignedCharTy;
16652 BestWidth = CharWidth;
16653 } else if (Packed && NumNegativeBits <= ShortWidth &&
16654 NumPositiveBits < ShortWidth) {
16655 BestType = Context.ShortTy;
16656 BestWidth = ShortWidth;
16657 } else if (NumNegativeBits <= IntWidth && NumPositiveBits < IntWidth) {
16658 BestType = Context.IntTy;
16659 BestWidth = IntWidth;
16661 BestWidth = Context.getTargetInfo().getLongWidth();
16663 if (NumNegativeBits <= BestWidth && NumPositiveBits < BestWidth) {
16664 BestType = Context.LongTy;
16666 BestWidth = Context.getTargetInfo().getLongLongWidth();
16668 if (NumNegativeBits > BestWidth || NumPositiveBits >= BestWidth)
16669 Diag(Enum->getLocation(), diag::ext_enum_too_large);
16670 BestType = Context.LongLongTy;
16673 BestPromotionType = (BestWidth <= IntWidth ? Context.IntTy : BestType);
16675 // If there is no negative value, figure out the smallest type that fits
16676 // all of the enumerator values.
16677 // If it's packed, check also if it fits a char or a short.
16678 if (Packed && NumPositiveBits <= CharWidth) {
16679 BestType = Context.UnsignedCharTy;
16680 BestPromotionType = Context.IntTy;
16681 BestWidth = CharWidth;
16682 } else if (Packed && NumPositiveBits <= ShortWidth) {
16683 BestType = Context.UnsignedShortTy;
16684 BestPromotionType = Context.IntTy;
16685 BestWidth = ShortWidth;
16686 } else if (NumPositiveBits <= IntWidth) {
16687 BestType = Context.UnsignedIntTy;
16688 BestWidth = IntWidth;
16690 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16691 ? Context.UnsignedIntTy : Context.IntTy;
16692 } else if (NumPositiveBits <=
16693 (BestWidth = Context.getTargetInfo().getLongWidth())) {
16694 BestType = Context.UnsignedLongTy;
16696 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16697 ? Context.UnsignedLongTy : Context.LongTy;
16699 BestWidth = Context.getTargetInfo().getLongLongWidth();
16700 assert(NumPositiveBits <= BestWidth &&
16701 "How could an initializer get larger than ULL?");
16702 BestType = Context.UnsignedLongLongTy;
16704 = (NumPositiveBits == BestWidth || !getLangOpts().CPlusPlus)
16705 ? Context.UnsignedLongLongTy : Context.LongLongTy;
16709 // Loop over all of the enumerator constants, changing their types to match
16710 // the type of the enum if needed.
16711 for (auto *D : Elements) {
16712 auto *ECD = cast_or_null<EnumConstantDecl>(D);
16713 if (!ECD) continue; // Already issued a diagnostic.
16715 // Standard C says the enumerators have int type, but we allow, as an
16716 // extension, the enumerators to be larger than int size. If each
16717 // enumerator value fits in an int, type it as an int, otherwise type it the
16718 // same as the enumerator decl itself. This means that in "enum { X = 1U }"
16719 // that X has type 'int', not 'unsigned'.
16721 // Determine whether the value fits into an int.
16722 llvm::APSInt InitVal = ECD->getInitVal();
16724 // If it fits into an integer type, force it. Otherwise force it to match
16725 // the enum decl type.
16729 if (!getLangOpts().CPlusPlus &&
16730 !Enum->isFixed() &&
16731 isRepresentableIntegerValue(Context, InitVal, Context.IntTy)) {
16732 NewTy = Context.IntTy;
16733 NewWidth = IntWidth;
16735 } else if (ECD->getType() == BestType) {
16736 // Already the right type!
16737 if (getLangOpts().CPlusPlus)
16738 // C++ [dcl.enum]p4: Following the closing brace of an
16739 // enum-specifier, each enumerator has the type of its
16741 ECD->setType(EnumType);
16745 NewWidth = BestWidth;
16746 NewSign = BestType->isSignedIntegerOrEnumerationType();
16749 // Adjust the APSInt value.
16750 InitVal = InitVal.extOrTrunc(NewWidth);
16751 InitVal.setIsSigned(NewSign);
16752 ECD->setInitVal(InitVal);
16754 // Adjust the Expr initializer and type.
16755 if (ECD->getInitExpr() &&
16756 !Context.hasSameType(NewTy, ECD->getInitExpr()->getType()))
16757 ECD->setInitExpr(ImplicitCastExpr::Create(Context, NewTy,
16759 ECD->getInitExpr(),
16760 /*base paths*/ nullptr,
16762 if (getLangOpts().CPlusPlus)
16763 // C++ [dcl.enum]p4: Following the closing brace of an
16764 // enum-specifier, each enumerator has the type of its
16766 ECD->setType(EnumType);
16768 ECD->setType(NewTy);
16771 Enum->completeDefinition(BestType, BestPromotionType,
16772 NumPositiveBits, NumNegativeBits);
16774 CheckForDuplicateEnumValues(*this, Elements, Enum, EnumType);
16776 if (Enum->isClosedFlag()) {
16777 for (Decl *D : Elements) {
16778 EnumConstantDecl *ECD = cast_or_null<EnumConstantDecl>(D);
16779 if (!ECD) continue; // Already issued a diagnostic.
16781 llvm::APSInt InitVal = ECD->getInitVal();
16782 if (InitVal != 0 && !InitVal.isPowerOf2() &&
16783 !IsValueInFlagEnum(Enum, InitVal, true))
16784 Diag(ECD->getLocation(), diag::warn_flag_enum_constant_out_of_range)
16789 // Now that the enum type is defined, ensure it's not been underaligned.
16790 if (Enum->hasAttrs())
16791 CheckAlignasUnderalignment(Enum);
16794 Decl *Sema::ActOnFileScopeAsmDecl(Expr *expr,
16795 SourceLocation StartLoc,
16796 SourceLocation EndLoc) {
16797 StringLiteral *AsmString = cast<StringLiteral>(expr);
16799 FileScopeAsmDecl *New = FileScopeAsmDecl::Create(Context, CurContext,
16800 AsmString, StartLoc,
16802 CurContext->addDecl(New);
16806 static void checkModuleImportContext(Sema &S, Module *M,
16807 SourceLocation ImportLoc, DeclContext *DC,
16808 bool FromInclude = false) {
16809 SourceLocation ExternCLoc;
16811 if (auto *LSD = dyn_cast<LinkageSpecDecl>(DC)) {
16812 switch (LSD->getLanguage()) {
16813 case LinkageSpecDecl::lang_c:
16814 if (ExternCLoc.isInvalid())
16815 ExternCLoc = LSD->getLocStart();
16817 case LinkageSpecDecl::lang_cxx:
16820 DC = LSD->getParent();
16823 while (isa<LinkageSpecDecl>(DC) || isa<ExportDecl>(DC))
16824 DC = DC->getParent();
16826 if (!isa<TranslationUnitDecl>(DC)) {
16827 S.Diag(ImportLoc, (FromInclude && S.isModuleVisible(M))
16828 ? diag::ext_module_import_not_at_top_level_noop
16829 : diag::err_module_import_not_at_top_level_fatal)
16830 << M->getFullModuleName() << DC;
16831 S.Diag(cast<Decl>(DC)->getLocStart(),
16832 diag::note_module_import_not_at_top_level) << DC;
16833 } else if (!M->IsExternC && ExternCLoc.isValid()) {
16834 S.Diag(ImportLoc, diag::ext_module_import_in_extern_c)
16835 << M->getFullModuleName();
16836 S.Diag(ExternCLoc, diag::note_extern_c_begins_here);
16840 Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc,
16841 SourceLocation ModuleLoc,
16842 ModuleDeclKind MDK,
16843 ModuleIdPath Path) {
16844 assert(getLangOpts().ModulesTS &&
16845 "should only have module decl in modules TS");
16847 // A module implementation unit requires that we are not compiling a module
16848 // of any kind. A module interface unit requires that we are not compiling a
16850 switch (getLangOpts().getCompilingModule()) {
16851 case LangOptions::CMK_None:
16852 // It's OK to compile a module interface as a normal translation unit.
16855 case LangOptions::CMK_ModuleInterface:
16856 if (MDK != ModuleDeclKind::Implementation)
16859 // We were asked to compile a module interface unit but this is a module
16860 // implementation unit. That indicates the 'export' is missing.
16861 Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch)
16862 << FixItHint::CreateInsertion(ModuleLoc, "export ");
16863 MDK = ModuleDeclKind::Interface;
16866 case LangOptions::CMK_ModuleMap:
16867 Diag(ModuleLoc, diag::err_module_decl_in_module_map_module);
16871 assert(ModuleScopes.size() == 1 && "expected to be at global module scope");
16873 // FIXME: Most of this work should be done by the preprocessor rather than
16874 // here, in order to support macro import.
16876 // Only one module-declaration is permitted per source file.
16877 if (ModuleScopes.back().Module->Kind == Module::ModuleInterfaceUnit) {
16878 Diag(ModuleLoc, diag::err_module_redeclaration);
16879 Diag(VisibleModules.getImportLoc(ModuleScopes.back().Module),
16880 diag::note_prev_module_declaration);
16884 // Flatten the dots in a module name. Unlike Clang's hierarchical module map
16885 // modules, the dots here are just another character that can appear in a
16887 std::string ModuleName;
16888 for (auto &Piece : Path) {
16889 if (!ModuleName.empty())
16891 ModuleName += Piece.first->getName();
16894 // If a module name was explicitly specified on the command line, it must be
16896 if (!getLangOpts().CurrentModule.empty() &&
16897 getLangOpts().CurrentModule != ModuleName) {
16898 Diag(Path.front().second, diag::err_current_module_name_mismatch)
16899 << SourceRange(Path.front().second, Path.back().second)
16900 << getLangOpts().CurrentModule;
16903 const_cast<LangOptions&>(getLangOpts()).CurrentModule = ModuleName;
16905 auto &Map = PP.getHeaderSearchInfo().getModuleMap();
16909 case ModuleDeclKind::Interface: {
16910 // We can't have parsed or imported a definition of this module or parsed a
16911 // module map defining it already.
16912 if (auto *M = Map.findModule(ModuleName)) {
16913 Diag(Path[0].second, diag::err_module_redefinition) << ModuleName;
16914 if (M->DefinitionLoc.isValid())
16915 Diag(M->DefinitionLoc, diag::note_prev_module_definition);
16916 else if (const auto *FE = M->getASTFile())
16917 Diag(M->DefinitionLoc, diag::note_prev_module_definition_from_ast_file)
16923 // Create a Module for the module that we're defining.
16924 Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName,
16925 ModuleScopes.front().Module);
16926 assert(Mod && "module creation should not fail");
16930 case ModuleDeclKind::Partition:
16931 // FIXME: Check we are in a submodule of the named module.
16934 case ModuleDeclKind::Implementation:
16935 std::pair<IdentifierInfo *, SourceLocation> ModuleNameLoc(
16936 PP.getIdentifierInfo(ModuleName), Path[0].second);
16937 Mod = getModuleLoader().loadModule(ModuleLoc, Path, Module::AllVisible,
16938 /*IsIncludeDirective=*/false);
16940 Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName;
16941 // Create an empty module interface unit for error recovery.
16942 Mod = Map.createModuleForInterfaceUnit(ModuleLoc, ModuleName,
16943 ModuleScopes.front().Module);
16948 // Switch from the global module to the named module.
16949 ModuleScopes.back().Module = Mod;
16950 ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation;
16951 VisibleModules.setVisible(Mod, ModuleLoc);
16953 // From now on, we have an owning module for all declarations we see.
16954 // However, those declarations are module-private unless explicitly
16956 auto *TU = Context.getTranslationUnitDecl();
16957 TU->setModuleOwnershipKind(Decl::ModuleOwnershipKind::ModulePrivate);
16958 TU->setLocalOwningModule(Mod);
16960 // FIXME: Create a ModuleDecl.
16964 DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc,
16965 SourceLocation ImportLoc,
16966 ModuleIdPath Path) {
16968 getModuleLoader().loadModule(ImportLoc, Path, Module::AllVisible,
16969 /*IsIncludeDirective=*/false);
16973 VisibleModules.setVisible(Mod, ImportLoc);
16975 checkModuleImportContext(*this, Mod, ImportLoc, CurContext);
16977 // FIXME: we should support importing a submodule within a different submodule
16978 // of the same top-level module. Until we do, make it an error rather than
16979 // silently ignoring the import.
16980 // Import-from-implementation is valid in the Modules TS. FIXME: Should we
16981 // warn on a redundant import of the current module?
16982 if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule &&
16983 (getLangOpts().isCompilingModule() || !getLangOpts().ModulesTS))
16984 Diag(ImportLoc, getLangOpts().isCompilingModule()
16985 ? diag::err_module_self_import
16986 : diag::err_module_import_in_implementation)
16987 << Mod->getFullModuleName() << getLangOpts().CurrentModule;
16989 SmallVector<SourceLocation, 2> IdentifierLocs;
16990 Module *ModCheck = Mod;
16991 for (unsigned I = 0, N = Path.size(); I != N; ++I) {
16992 // If we've run out of module parents, just drop the remaining identifiers.
16993 // We need the length to be consistent.
16996 ModCheck = ModCheck->Parent;
16998 IdentifierLocs.push_back(Path[I].second);
17001 ImportDecl *Import = ImportDecl::Create(Context, CurContext, StartLoc,
17002 Mod, IdentifierLocs);
17003 if (!ModuleScopes.empty())
17004 Context.addModuleInitializer(ModuleScopes.back().Module, Import);
17005 CurContext->addDecl(Import);
17007 // Re-export the module if needed.
17008 if (Import->isExported() &&
17009 !ModuleScopes.empty() && ModuleScopes.back().ModuleInterface)
17010 getCurrentModule()->Exports.emplace_back(Mod, false);
17015 void Sema::ActOnModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
17016 checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
17017 BuildModuleInclude(DirectiveLoc, Mod);
17020 void Sema::BuildModuleInclude(SourceLocation DirectiveLoc, Module *Mod) {
17021 // Determine whether we're in the #include buffer for a module. The #includes
17022 // in that buffer do not qualify as module imports; they're just an
17023 // implementation detail of us building the module.
17025 // FIXME: Should we even get ActOnModuleInclude calls for those?
17026 bool IsInModuleIncludes =
17027 TUKind == TU_Module &&
17028 getSourceManager().isWrittenInMainFile(DirectiveLoc);
17030 bool ShouldAddImport = !IsInModuleIncludes;
17032 // If this module import was due to an inclusion directive, create an
17033 // implicit import declaration to capture it in the AST.
17034 if (ShouldAddImport) {
17035 TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
17036 ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
17039 if (!ModuleScopes.empty())
17040 Context.addModuleInitializer(ModuleScopes.back().Module, ImportD);
17041 TU->addDecl(ImportD);
17042 Consumer.HandleImplicitImportDecl(ImportD);
17045 getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, DirectiveLoc);
17046 VisibleModules.setVisible(Mod, DirectiveLoc);
17049 void Sema::ActOnModuleBegin(SourceLocation DirectiveLoc, Module *Mod) {
17050 checkModuleImportContext(*this, Mod, DirectiveLoc, CurContext, true);
17052 ModuleScopes.push_back({});
17053 ModuleScopes.back().Module = Mod;
17054 if (getLangOpts().ModulesLocalVisibility)
17055 ModuleScopes.back().OuterVisibleModules = std::move(VisibleModules);
17057 VisibleModules.setVisible(Mod, DirectiveLoc);
17059 // The enclosing context is now part of this module.
17060 // FIXME: Consider creating a child DeclContext to hold the entities
17061 // lexically within the module.
17062 if (getLangOpts().trackLocalOwningModule()) {
17063 for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) {
17064 cast<Decl>(DC)->setModuleOwnershipKind(
17065 getLangOpts().ModulesLocalVisibility
17066 ? Decl::ModuleOwnershipKind::VisibleWhenImported
17067 : Decl::ModuleOwnershipKind::Visible);
17068 cast<Decl>(DC)->setLocalOwningModule(Mod);
17073 void Sema::ActOnModuleEnd(SourceLocation EomLoc, Module *Mod) {
17074 if (getLangOpts().ModulesLocalVisibility) {
17075 VisibleModules = std::move(ModuleScopes.back().OuterVisibleModules);
17076 // Leaving a module hides namespace names, so our visible namespace cache
17077 // is now out of date.
17078 VisibleNamespaceCache.clear();
17081 assert(!ModuleScopes.empty() && ModuleScopes.back().Module == Mod &&
17082 "left the wrong module scope");
17083 ModuleScopes.pop_back();
17085 // We got to the end of processing a local module. Create an
17086 // ImportDecl as we would for an imported module.
17087 FileID File = getSourceManager().getFileID(EomLoc);
17088 SourceLocation DirectiveLoc;
17089 if (EomLoc == getSourceManager().getLocForEndOfFile(File)) {
17090 // We reached the end of a #included module header. Use the #include loc.
17091 assert(File != getSourceManager().getMainFileID() &&
17092 "end of submodule in main source file");
17093 DirectiveLoc = getSourceManager().getIncludeLoc(File);
17095 // We reached an EOM pragma. Use the pragma location.
17096 DirectiveLoc = EomLoc;
17098 BuildModuleInclude(DirectiveLoc, Mod);
17100 // Any further declarations are in whatever module we returned to.
17101 if (getLangOpts().trackLocalOwningModule()) {
17102 // The parser guarantees that this is the same context that we entered
17103 // the module within.
17104 for (auto *DC = CurContext; DC; DC = DC->getLexicalParent()) {
17105 cast<Decl>(DC)->setLocalOwningModule(getCurrentModule());
17106 if (!getCurrentModule())
17107 cast<Decl>(DC)->setModuleOwnershipKind(
17108 Decl::ModuleOwnershipKind::Unowned);
17113 void Sema::createImplicitModuleImportForErrorRecovery(SourceLocation Loc,
17115 // Bail if we're not allowed to implicitly import a module here.
17116 if (isSFINAEContext() || !getLangOpts().ModulesErrorRecovery ||
17117 VisibleModules.isVisible(Mod))
17120 // Create the implicit import declaration.
17121 TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
17122 ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
17124 TU->addDecl(ImportD);
17125 Consumer.HandleImplicitImportDecl(ImportD);
17127 // Make the module visible.
17128 getModuleLoader().makeModuleVisible(Mod, Module::AllVisible, Loc);
17129 VisibleModules.setVisible(Mod, Loc);
17132 /// We have parsed the start of an export declaration, including the '{'
17134 Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
17135 SourceLocation LBraceLoc) {
17136 ExportDecl *D = ExportDecl::Create(Context, CurContext, ExportLoc);
17138 // C++ Modules TS draft:
17139 // An export-declaration shall appear in the purview of a module other than
17140 // the global module.
17141 if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface)
17142 Diag(ExportLoc, diag::err_export_not_in_module_interface);
17144 // An export-declaration [...] shall not contain more than one
17147 // The intent here is that an export-declaration cannot appear within another
17148 // export-declaration.
17149 if (D->isExported())
17150 Diag(ExportLoc, diag::err_export_within_export);
17152 CurContext->addDecl(D);
17153 PushDeclContext(S, D);
17154 D->setModuleOwnershipKind(Decl::ModuleOwnershipKind::VisibleWhenImported);
17158 /// Complete the definition of an export declaration.
17159 Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) {
17160 auto *ED = cast<ExportDecl>(D);
17161 if (RBraceLoc.isValid())
17162 ED->setRBraceLoc(RBraceLoc);
17164 // FIXME: Diagnose export of internal-linkage declaration (including
17165 // anonymous namespace).
17171 void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
17172 IdentifierInfo* AliasName,
17173 SourceLocation PragmaLoc,
17174 SourceLocation NameLoc,
17175 SourceLocation AliasNameLoc) {
17176 NamedDecl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc,
17177 LookupOrdinaryName);
17178 AsmLabelAttr *Attr =
17179 AsmLabelAttr::CreateImplicit(Context, AliasName->getName(), AliasNameLoc);
17181 // If a declaration that:
17182 // 1) declares a function or a variable
17183 // 2) has external linkage
17184 // already exists, add a label attribute to it.
17185 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
17186 if (isDeclExternC(PrevDecl))
17187 PrevDecl->addAttr(Attr);
17189 Diag(PrevDecl->getLocation(), diag::warn_redefine_extname_not_applied)
17190 << /*Variable*/(isa<FunctionDecl>(PrevDecl) ? 0 : 1) << PrevDecl;
17191 // Otherwise, add a label atttibute to ExtnameUndeclaredIdentifiers.
17193 (void)ExtnameUndeclaredIdentifiers.insert(std::make_pair(Name, Attr));
17196 void Sema::ActOnPragmaWeakID(IdentifierInfo* Name,
17197 SourceLocation PragmaLoc,
17198 SourceLocation NameLoc) {
17199 Decl *PrevDecl = LookupSingleName(TUScope, Name, NameLoc, LookupOrdinaryName);
17202 PrevDecl->addAttr(WeakAttr::CreateImplicit(Context, PragmaLoc));
17204 (void)WeakUndeclaredIdentifiers.insert(
17205 std::pair<IdentifierInfo*,WeakInfo>
17206 (Name, WeakInfo((IdentifierInfo*)nullptr, NameLoc)));
17210 void Sema::ActOnPragmaWeakAlias(IdentifierInfo* Name,
17211 IdentifierInfo* AliasName,
17212 SourceLocation PragmaLoc,
17213 SourceLocation NameLoc,
17214 SourceLocation AliasNameLoc) {
17215 Decl *PrevDecl = LookupSingleName(TUScope, AliasName, AliasNameLoc,
17216 LookupOrdinaryName);
17217 WeakInfo W = WeakInfo(Name, NameLoc);
17219 if (PrevDecl && (isa<FunctionDecl>(PrevDecl) || isa<VarDecl>(PrevDecl))) {
17220 if (!PrevDecl->hasAttr<AliasAttr>())
17221 if (NamedDecl *ND = dyn_cast<NamedDecl>(PrevDecl))
17222 DeclApplyPragmaWeak(TUScope, ND, W);
17224 (void)WeakUndeclaredIdentifiers.insert(
17225 std::pair<IdentifierInfo*,WeakInfo>(AliasName, W));
17229 Decl *Sema::getObjCDeclContext() const {
17230 return (dyn_cast_or_null<ObjCContainerDecl>(CurContext));