1 //===--- SemaCXXScopeSpec.cpp - Semantic Analysis for C++ scope specifiers-===//
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 C++ semantic analysis for scope specifiers.
12 //===----------------------------------------------------------------------===//
14 #include "clang/Sema/SemaInternal.h"
15 #include "TypeLocBuilder.h"
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/DeclTemplate.h"
18 #include "clang/AST/ExprCXX.h"
19 #include "clang/AST/NestedNameSpecifier.h"
20 #include "clang/Basic/PartialDiagnostic.h"
21 #include "clang/Sema/DeclSpec.h"
22 #include "clang/Sema/Lookup.h"
23 #include "clang/Sema/Template.h"
24 #include "llvm/ADT/STLExtras.h"
25 #include "llvm/Support/raw_ostream.h"
26 using namespace clang;
28 /// \brief Find the current instantiation that associated with the given type.
29 static CXXRecordDecl *getCurrentInstantiationOf(QualType T,
30 DeclContext *CurContext) {
34 const Type *Ty = T->getCanonicalTypeInternal().getTypePtr();
35 if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) {
36 CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl());
37 if (!Record->isDependentContext() ||
38 Record->isCurrentInstantiation(CurContext))
42 } else if (isa<InjectedClassNameType>(Ty))
43 return cast<InjectedClassNameType>(Ty)->getDecl();
48 /// \brief Compute the DeclContext that is associated with the given type.
50 /// \param T the type for which we are attempting to find a DeclContext.
52 /// \returns the declaration context represented by the type T,
53 /// or NULL if the declaration context cannot be computed (e.g., because it is
54 /// dependent and not the current instantiation).
55 DeclContext *Sema::computeDeclContext(QualType T) {
56 if (!T->isDependentType())
57 if (const TagType *Tag = T->getAs<TagType>())
58 return Tag->getDecl();
60 return ::getCurrentInstantiationOf(T, CurContext);
63 /// \brief Compute the DeclContext that is associated with the given
66 /// \param SS the C++ scope specifier as it appears in the source
68 /// \param EnteringContext when true, we will be entering the context of
69 /// this scope specifier, so we can retrieve the declaration context of a
70 /// class template or class template partial specialization even if it is
71 /// not the current instantiation.
73 /// \returns the declaration context represented by the scope specifier @p SS,
74 /// or NULL if the declaration context cannot be computed (e.g., because it is
75 /// dependent and not the current instantiation).
76 DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS,
77 bool EnteringContext) {
78 if (!SS.isSet() || SS.isInvalid())
81 NestedNameSpecifier *NNS = SS.getScopeRep();
82 if (NNS->isDependent()) {
83 // If this nested-name-specifier refers to the current
84 // instantiation, return its DeclContext.
85 if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS))
88 if (EnteringContext) {
89 const Type *NNSType = NNS->getAsType();
94 // Look through type alias templates, per C++0x [temp.dep.type]p1.
95 NNSType = Context.getCanonicalType(NNSType);
96 if (const TemplateSpecializationType *SpecType
97 = NNSType->getAs<TemplateSpecializationType>()) {
98 // We are entering the context of the nested name specifier, so try to
99 // match the nested name specifier to either a primary class template
100 // or a class template partial specialization.
101 if (ClassTemplateDecl *ClassTemplate
102 = dyn_cast_or_null<ClassTemplateDecl>(
103 SpecType->getTemplateName().getAsTemplateDecl())) {
105 = Context.getCanonicalType(QualType(SpecType, 0));
107 // If the type of the nested name specifier is the same as the
108 // injected class name of the named class template, we're entering
109 // into that class template definition.
111 = ClassTemplate->getInjectedClassNameSpecialization();
112 if (Context.hasSameType(Injected, ContextType))
113 return ClassTemplate->getTemplatedDecl();
115 // If the type of the nested name specifier is the same as the
116 // type of one of the class template's class template partial
117 // specializations, we're entering into the definition of that
118 // class template partial specialization.
119 if (ClassTemplatePartialSpecializationDecl *PartialSpec
120 = ClassTemplate->findPartialSpecialization(ContextType))
123 } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) {
124 // The nested name specifier refers to a member of a class template.
125 return RecordT->getDecl();
132 switch (NNS->getKind()) {
133 case NestedNameSpecifier::Identifier:
134 llvm_unreachable("Dependent nested-name-specifier has no DeclContext");
136 case NestedNameSpecifier::Namespace:
137 return NNS->getAsNamespace();
139 case NestedNameSpecifier::NamespaceAlias:
140 return NNS->getAsNamespaceAlias()->getNamespace();
142 case NestedNameSpecifier::TypeSpec:
143 case NestedNameSpecifier::TypeSpecWithTemplate: {
144 const TagType *Tag = NNS->getAsType()->getAs<TagType>();
145 assert(Tag && "Non-tag type in nested-name-specifier");
146 return Tag->getDecl();
149 case NestedNameSpecifier::Global:
150 return Context.getTranslationUnitDecl();
153 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
156 bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) {
157 if (!SS.isSet() || SS.isInvalid())
160 return SS.getScopeRep()->isDependent();
163 /// \brief If the given nested name specifier refers to the current
164 /// instantiation, return the declaration that corresponds to that
165 /// current instantiation (C++0x [temp.dep.type]p1).
167 /// \param NNS a dependent nested name specifier.
168 CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) {
169 assert(getLangOpts().CPlusPlus && "Only callable in C++");
170 assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed");
172 if (!NNS->getAsType())
175 QualType T = QualType(NNS->getAsType(), 0);
176 return ::getCurrentInstantiationOf(T, CurContext);
179 /// \brief Require that the context specified by SS be complete.
181 /// If SS refers to a type, this routine checks whether the type is
182 /// complete enough (or can be made complete enough) for name lookup
183 /// into the DeclContext. A type that is not yet completed can be
184 /// considered "complete enough" if it is a class/struct/union/enum
185 /// that is currently being defined. Or, if we have a type that names
186 /// a class template specialization that is not a complete type, we
187 /// will attempt to instantiate that class template.
188 bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS,
190 assert(DC != 0 && "given null context");
192 TagDecl *tag = dyn_cast<TagDecl>(DC);
194 // If this is a dependent type, then we consider it complete.
195 if (!tag || tag->isDependentContext())
198 // If we're currently defining this type, then lookup into the
199 // type is okay: don't complain that it isn't complete yet.
200 QualType type = Context.getTypeDeclType(tag);
201 const TagType *tagType = type->getAs<TagType>();
202 if (tagType && tagType->isBeingDefined())
205 SourceLocation loc = SS.getLastQualifierNameLoc();
206 if (loc.isInvalid()) loc = SS.getRange().getBegin();
208 // The type must be complete.
209 if (RequireCompleteType(loc, type, diag::err_incomplete_nested_name_spec,
211 SS.SetInvalid(SS.getRange());
215 // Fixed enum types are complete, but they aren't valid as scopes
216 // until we see a definition, so awkwardly pull out this special
218 const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType);
219 if (!enumType || enumType->getDecl()->isCompleteDefinition())
222 // Try to instantiate the definition, if this is a specialization of an
223 // enumeration temploid.
224 EnumDecl *ED = enumType->getDecl();
225 if (EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) {
226 MemberSpecializationInfo *MSI = ED->getMemberSpecializationInfo();
227 if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) {
228 if (InstantiateEnum(loc, ED, Pattern, getTemplateInstantiationArgs(ED),
229 TSK_ImplicitInstantiation)) {
230 SS.SetInvalid(SS.getRange());
237 Diag(loc, diag::err_incomplete_nested_name_spec)
238 << type << SS.getRange();
239 SS.SetInvalid(SS.getRange());
243 bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc,
245 SS.MakeGlobal(Context, CCLoc);
249 /// \brief Determines whether the given declaration is an valid acceptable
250 /// result for name lookup of a nested-name-specifier.
251 bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD) {
255 // Namespace and namespace aliases are fine.
256 if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD))
259 if (!isa<TypeDecl>(SD))
262 // Determine whether we have a class (or, in C++11, an enum) or
263 // a typedef thereof. If so, build the nested-name-specifier.
264 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
265 if (T->isDependentType())
267 else if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) {
268 if (TD->getUnderlyingType()->isRecordType() ||
269 (Context.getLangOpts().CPlusPlus11 &&
270 TD->getUnderlyingType()->isEnumeralType()))
272 } else if (isa<RecordDecl>(SD) ||
273 (Context.getLangOpts().CPlusPlus11 && isa<EnumDecl>(SD)))
279 /// \brief If the given nested-name-specifier begins with a bare identifier
280 /// (e.g., Base::), perform name lookup for that identifier as a
281 /// nested-name-specifier within the given scope, and return the result of that
283 NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) {
287 while (NNS->getPrefix())
288 NNS = NNS->getPrefix();
290 if (NNS->getKind() != NestedNameSpecifier::Identifier)
293 LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(),
294 LookupNestedNameSpecifierName);
295 LookupName(Found, S);
296 assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet");
298 if (!Found.isSingleResult())
301 NamedDecl *Result = Found.getFoundDecl();
302 if (isAcceptableNestedNameSpecifier(Result))
308 bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS,
309 SourceLocation IdLoc,
311 ParsedType ObjectTypePtr) {
312 QualType ObjectType = GetTypeFromParser(ObjectTypePtr);
313 LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName);
315 // Determine where to perform name lookup
316 DeclContext *LookupCtx = 0;
317 bool isDependent = false;
318 if (!ObjectType.isNull()) {
319 // This nested-name-specifier occurs in a member access expression, e.g.,
320 // x->B::f, and we are looking into the type of the object.
321 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
322 LookupCtx = computeDeclContext(ObjectType);
323 isDependent = ObjectType->isDependentType();
324 } else if (SS.isSet()) {
325 // This nested-name-specifier occurs after another nested-name-specifier,
326 // so long into the context associated with the prior nested-name-specifier.
327 LookupCtx = computeDeclContext(SS, false);
328 isDependent = isDependentScopeSpecifier(SS);
329 Found.setContextRange(SS.getRange());
333 // Perform "qualified" name lookup into the declaration context we
334 // computed, which is either the type of the base of a member access
335 // expression or the declaration context associated with a prior
336 // nested-name-specifier.
338 // The declaration context must be complete.
339 if (!LookupCtx->isDependentContext() &&
340 RequireCompleteDeclContext(SS, LookupCtx))
343 LookupQualifiedName(Found, LookupCtx);
344 } else if (isDependent) {
347 LookupName(Found, S);
349 Found.suppressDiagnostics();
351 if (NamedDecl *ND = Found.getAsSingle<NamedDecl>())
352 return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND);
359 // Callback to only accept typo corrections that can be a valid C++ member
360 // intializer: either a non-static field member or a base class.
361 class NestedNameSpecifierValidatorCCC : public CorrectionCandidateCallback {
363 explicit NestedNameSpecifierValidatorCCC(Sema &SRef)
366 virtual bool ValidateCandidate(const TypoCorrection &candidate) {
367 return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl());
376 /// \brief Build a new nested-name-specifier for "identifier::", as described
377 /// by ActOnCXXNestedNameSpecifier.
379 /// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in
380 /// that it contains an extra parameter \p ScopeLookupResult, which provides
381 /// the result of name lookup within the scope of the nested-name-specifier
382 /// that was computed at template definition time.
384 /// If ErrorRecoveryLookup is true, then this call is used to improve error
385 /// recovery. This means that it should not emit diagnostics, it should
386 /// just return true on failure. It also means it should only return a valid
387 /// scope if it *knows* that the result is correct. It should not return in a
388 /// dependent context, for example. Nor will it extend \p SS with the scope
390 bool Sema::BuildCXXNestedNameSpecifier(Scope *S,
391 IdentifierInfo &Identifier,
392 SourceLocation IdentifierLoc,
393 SourceLocation CCLoc,
395 bool EnteringContext,
397 NamedDecl *ScopeLookupResult,
398 bool ErrorRecoveryLookup) {
399 LookupResult Found(*this, &Identifier, IdentifierLoc,
400 LookupNestedNameSpecifierName);
402 // Determine where to perform name lookup
403 DeclContext *LookupCtx = 0;
404 bool isDependent = false;
405 if (!ObjectType.isNull()) {
406 // This nested-name-specifier occurs in a member access expression, e.g.,
407 // x->B::f, and we are looking into the type of the object.
408 assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
409 LookupCtx = computeDeclContext(ObjectType);
410 isDependent = ObjectType->isDependentType();
411 } else if (SS.isSet()) {
412 // This nested-name-specifier occurs after another nested-name-specifier,
413 // so look into the context associated with the prior nested-name-specifier.
414 LookupCtx = computeDeclContext(SS, EnteringContext);
415 isDependent = isDependentScopeSpecifier(SS);
416 Found.setContextRange(SS.getRange());
420 bool ObjectTypeSearchedInScope = false;
422 // Perform "qualified" name lookup into the declaration context we
423 // computed, which is either the type of the base of a member access
424 // expression or the declaration context associated with a prior
425 // nested-name-specifier.
427 // The declaration context must be complete.
428 if (!LookupCtx->isDependentContext() &&
429 RequireCompleteDeclContext(SS, LookupCtx))
432 LookupQualifiedName(Found, LookupCtx);
434 if (!ObjectType.isNull() && Found.empty()) {
435 // C++ [basic.lookup.classref]p4:
436 // If the id-expression in a class member access is a qualified-id of
439 // class-name-or-namespace-name::...
441 // the class-name-or-namespace-name following the . or -> operator is
442 // looked up both in the context of the entire postfix-expression and in
443 // the scope of the class of the object expression. If the name is found
444 // only in the scope of the class of the object expression, the name
445 // shall refer to a class-name. If the name is found only in the
446 // context of the entire postfix-expression, the name shall refer to a
447 // class-name or namespace-name. [...]
449 // Qualified name lookup into a class will not find a namespace-name,
450 // so we do not need to diagnose that case specifically. However,
451 // this qualified name lookup may find nothing. In that case, perform
452 // unqualified name lookup in the given scope (if available) or
453 // reconstruct the result from when name lookup was performed at template
456 LookupName(Found, S);
457 else if (ScopeLookupResult)
458 Found.addDecl(ScopeLookupResult);
460 ObjectTypeSearchedInScope = true;
462 } else if (!isDependent) {
463 // Perform unqualified name lookup in the current scope.
464 LookupName(Found, S);
467 // If we performed lookup into a dependent context and did not find anything,
468 // that's fine: just build a dependent nested-name-specifier.
469 if (Found.empty() && isDependent &&
470 !(LookupCtx && LookupCtx->isRecord() &&
471 (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
472 !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) {
473 // Don't speculate if we're just trying to improve error recovery.
474 if (ErrorRecoveryLookup)
477 // We were not able to compute the declaration context for a dependent
478 // base object type or prior nested-name-specifier, so this
479 // nested-name-specifier refers to an unknown specialization. Just build
480 // a dependent nested-name-specifier.
481 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
485 // FIXME: Deal with ambiguities cleanly.
487 if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MicrosoftMode) {
488 // We haven't found anything, and we're not recovering from a
489 // different kind of error, so look for typos.
490 DeclarationName Name = Found.getLookupName();
491 NestedNameSpecifierValidatorCCC Validator(*this);
493 if (TypoCorrection Corrected =
494 CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S,
495 &SS, Validator, LookupCtx, EnteringContext)) {
497 bool DroppedSpecifier =
498 Corrected.WillReplaceSpecifier() &&
499 Name.getAsString() == Corrected.getAsString(getLangOpts());
500 if (DroppedSpecifier)
502 diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest)
503 << Name << LookupCtx << DroppedSpecifier
506 diagnoseTypo(Corrected, PDiag(diag::err_undeclared_var_use_suggest)
509 if (NamedDecl *ND = Corrected.getCorrectionDecl())
511 Found.setLookupName(Corrected.getCorrection());
513 Found.setLookupName(&Identifier);
517 NamedDecl *SD = Found.getAsSingle<NamedDecl>();
518 if (isAcceptableNestedNameSpecifier(SD)) {
519 if (!ObjectType.isNull() && !ObjectTypeSearchedInScope &&
520 !getLangOpts().CPlusPlus11) {
521 // C++03 [basic.lookup.classref]p4:
522 // [...] If the name is found in both contexts, the
523 // class-name-or-namespace-name shall refer to the same entity.
525 // We already found the name in the scope of the object. Now, look
526 // into the current scope (the scope of the postfix-expression) to
527 // see if we can find the same name there. As above, if there is no
528 // scope, reconstruct the result from the template instantiation itself.
530 // Note that C++11 does *not* perform this redundant lookup.
531 NamedDecl *OuterDecl;
533 LookupResult FoundOuter(*this, &Identifier, IdentifierLoc,
534 LookupNestedNameSpecifierName);
535 LookupName(FoundOuter, S);
536 OuterDecl = FoundOuter.getAsSingle<NamedDecl>();
538 OuterDecl = ScopeLookupResult;
540 if (isAcceptableNestedNameSpecifier(OuterDecl) &&
541 OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() &&
542 (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) ||
543 !Context.hasSameType(
544 Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)),
545 Context.getTypeDeclType(cast<TypeDecl>(SD))))) {
546 if (ErrorRecoveryLookup)
550 diag::err_nested_name_member_ref_lookup_ambiguous)
552 Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type)
554 Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope);
556 // Fall through so that we'll pick the name we found in the object
557 // type, since that's probably what the user wanted anyway.
561 // If we're just performing this lookup for error-recovery purposes,
562 // don't extend the nested-name-specifier. Just return now.
563 if (ErrorRecoveryLookup)
566 if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) {
567 SS.Extend(Context, Namespace, IdentifierLoc, CCLoc);
571 if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) {
572 SS.Extend(Context, Alias, IdentifierLoc, CCLoc);
576 QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD));
578 if (isa<InjectedClassNameType>(T)) {
579 InjectedClassNameTypeLoc InjectedTL
580 = TLB.push<InjectedClassNameTypeLoc>(T);
581 InjectedTL.setNameLoc(IdentifierLoc);
582 } else if (isa<RecordType>(T)) {
583 RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T);
584 RecordTL.setNameLoc(IdentifierLoc);
585 } else if (isa<TypedefType>(T)) {
586 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T);
587 TypedefTL.setNameLoc(IdentifierLoc);
588 } else if (isa<EnumType>(T)) {
589 EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T);
590 EnumTL.setNameLoc(IdentifierLoc);
591 } else if (isa<TemplateTypeParmType>(T)) {
592 TemplateTypeParmTypeLoc TemplateTypeTL
593 = TLB.push<TemplateTypeParmTypeLoc>(T);
594 TemplateTypeTL.setNameLoc(IdentifierLoc);
595 } else if (isa<UnresolvedUsingType>(T)) {
596 UnresolvedUsingTypeLoc UnresolvedTL
597 = TLB.push<UnresolvedUsingTypeLoc>(T);
598 UnresolvedTL.setNameLoc(IdentifierLoc);
599 } else if (isa<SubstTemplateTypeParmType>(T)) {
600 SubstTemplateTypeParmTypeLoc TL
601 = TLB.push<SubstTemplateTypeParmTypeLoc>(T);
602 TL.setNameLoc(IdentifierLoc);
603 } else if (isa<SubstTemplateTypeParmPackType>(T)) {
604 SubstTemplateTypeParmPackTypeLoc TL
605 = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T);
606 TL.setNameLoc(IdentifierLoc);
608 llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier");
611 if (T->isEnumeralType())
612 Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec);
614 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
619 // Otherwise, we have an error case. If we don't want diagnostics, just
620 // return an error now.
621 if (ErrorRecoveryLookup)
624 // If we didn't find anything during our lookup, try again with
625 // ordinary name lookup, which can help us produce better error
628 Found.clear(LookupOrdinaryName);
629 LookupName(Found, S);
632 // In Microsoft mode, if we are within a templated function and we can't
633 // resolve Identifier, then extend the SS with Identifier. This will have
634 // the effect of resolving Identifier during template instantiation.
635 // The goal is to be able to resolve a function call whose
636 // nested-name-specifier is located inside a dependent base class.
641 // static void foo2() { }
643 // template <class T> class A { public: typedef C D; };
645 // template <class T> class B : public A<T> {
647 // void foo() { D::foo2(); }
649 if (getLangOpts().MicrosoftMode) {
650 DeclContext *DC = LookupCtx ? LookupCtx : CurContext;
651 if (DC->isDependentContext() && DC->isFunctionOrMethod()) {
652 SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
659 DiagID = diag::err_expected_class_or_namespace;
660 else if (SS.isSet()) {
661 Diag(IdentifierLoc, diag::err_no_member)
662 << &Identifier << LookupCtx << SS.getRange();
665 DiagID = diag::err_undeclared_var_use;
668 Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange();
670 Diag(IdentifierLoc, DiagID) << &Identifier;
675 bool Sema::ActOnCXXNestedNameSpecifier(Scope *S,
676 IdentifierInfo &Identifier,
677 SourceLocation IdentifierLoc,
678 SourceLocation CCLoc,
679 ParsedType ObjectType,
680 bool EnteringContext,
685 return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc,
686 GetTypeFromParser(ObjectType),
688 /*ScopeLookupResult=*/0, false);
691 bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS,
693 SourceLocation ColonColonLoc) {
694 if (SS.isInvalid() || DS.getTypeSpecType() == DeclSpec::TST_error)
697 assert(DS.getTypeSpecType() == DeclSpec::TST_decltype);
699 QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc());
700 if (!T->isDependentType() && !T->getAs<TagType>()) {
701 Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class)
702 << T << getLangOpts().CPlusPlus;
707 DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T);
708 DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc());
709 SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T),
714 /// IsInvalidUnlessNestedName - This method is used for error recovery
715 /// purposes to determine whether the specified identifier is only valid as
716 /// a nested name specifier, for example a namespace name. It is
717 /// conservatively correct to always return false from this method.
719 /// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier.
720 bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS,
721 IdentifierInfo &Identifier,
722 SourceLocation IdentifierLoc,
723 SourceLocation ColonLoc,
724 ParsedType ObjectType,
725 bool EnteringContext) {
729 return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc,
730 GetTypeFromParser(ObjectType),
732 /*ScopeLookupResult=*/0, true);
735 bool Sema::ActOnCXXNestedNameSpecifier(Scope *S,
737 SourceLocation TemplateKWLoc,
739 SourceLocation TemplateNameLoc,
740 SourceLocation LAngleLoc,
741 ASTTemplateArgsPtr TemplateArgsIn,
742 SourceLocation RAngleLoc,
743 SourceLocation CCLoc,
744 bool EnteringContext) {
748 // Translate the parser's template argument list in our AST format.
749 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
750 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
752 if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){
753 // Handle a dependent template specialization for which we cannot resolve
754 // the template name.
755 assert(DTN->getQualifier() == SS.getScopeRep());
756 QualType T = Context.getDependentTemplateSpecializationType(ETK_None,
758 DTN->getIdentifier(),
761 // Create source-location information for this type.
762 TypeLocBuilder Builder;
763 DependentTemplateSpecializationTypeLoc SpecTL
764 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
765 SpecTL.setElaboratedKeywordLoc(SourceLocation());
766 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
767 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
768 SpecTL.setTemplateNameLoc(TemplateNameLoc);
769 SpecTL.setLAngleLoc(LAngleLoc);
770 SpecTL.setRAngleLoc(RAngleLoc);
771 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
772 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
774 SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T),
780 if (Template.get().getAsOverloadedTemplate() ||
781 isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) {
782 SourceRange R(TemplateNameLoc, RAngleLoc);
783 if (SS.getRange().isValid())
784 R.setBegin(SS.getRange().getBegin());
786 Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier)
787 << Template.get() << R;
788 NoteAllFoundTemplates(Template.get());
792 // We were able to resolve the template name to an actual template.
793 // Build an appropriate nested-name-specifier.
794 QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc,
799 // Alias template specializations can produce types which are not valid
800 // nested name specifiers.
801 if (!T->isDependentType() && !T->getAs<TagType>()) {
802 Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T;
803 NoteAllFoundTemplates(Template.get());
807 // Provide source-location information for the template specialization type.
808 TypeLocBuilder Builder;
809 TemplateSpecializationTypeLoc SpecTL
810 = Builder.push<TemplateSpecializationTypeLoc>(T);
811 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
812 SpecTL.setTemplateNameLoc(TemplateNameLoc);
813 SpecTL.setLAngleLoc(LAngleLoc);
814 SpecTL.setRAngleLoc(RAngleLoc);
815 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
816 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
819 SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T),
825 /// \brief A structure that stores a nested-name-specifier annotation,
826 /// including both the nested-name-specifier
827 struct NestedNameSpecifierAnnotation {
828 NestedNameSpecifier *NNS;
832 void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) {
833 if (SS.isEmpty() || SS.isInvalid())
836 void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) +
838 llvm::alignOf<NestedNameSpecifierAnnotation>());
839 NestedNameSpecifierAnnotation *Annotation
840 = new (Mem) NestedNameSpecifierAnnotation;
841 Annotation->NNS = SS.getScopeRep();
842 memcpy(Annotation + 1, SS.location_data(), SS.location_size());
846 void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr,
847 SourceRange AnnotationRange,
849 if (!AnnotationPtr) {
850 SS.SetInvalid(AnnotationRange);
854 NestedNameSpecifierAnnotation *Annotation
855 = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr);
856 SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1));
859 bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
860 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
862 NestedNameSpecifier *Qualifier = SS.getScopeRep();
864 // There are only two places a well-formed program may qualify a
865 // declarator: first, when defining a namespace or class member
866 // out-of-line, and second, when naming an explicitly-qualified
867 // friend function. The latter case is governed by
868 // C++03 [basic.lookup.unqual]p10:
869 // In a friend declaration naming a member function, a name used
870 // in the function declarator and not part of a template-argument
871 // in a template-id is first looked up in the scope of the member
872 // function's class. If it is not found, or if the name is part of
873 // a template-argument in a template-id, the look up is as
874 // described for unqualified names in the definition of the class
875 // granting friendship.
876 // i.e. we don't push a scope unless it's a class member.
878 switch (Qualifier->getKind()) {
879 case NestedNameSpecifier::Global:
880 case NestedNameSpecifier::Namespace:
881 case NestedNameSpecifier::NamespaceAlias:
882 // These are always namespace scopes. We never want to enter a
883 // namespace scope from anything but a file context.
884 return CurContext->getRedeclContext()->isFileContext();
886 case NestedNameSpecifier::Identifier:
887 case NestedNameSpecifier::TypeSpec:
888 case NestedNameSpecifier::TypeSpecWithTemplate:
889 // These are never namespace scopes.
893 llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
896 /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global
897 /// scope or nested-name-specifier) is parsed, part of a declarator-id.
898 /// After this method is called, according to [C++ 3.4.3p3], names should be
899 /// looked up in the declarator-id's scope, until the declarator is parsed and
900 /// ActOnCXXExitDeclaratorScope is called.
901 /// The 'SS' should be a non-empty valid CXXScopeSpec.
902 bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) {
903 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
905 if (SS.isInvalid()) return true;
907 DeclContext *DC = computeDeclContext(SS, true);
908 if (!DC) return true;
910 // Before we enter a declarator's context, we need to make sure that
911 // it is a complete declaration context.
912 if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC))
915 EnterDeclaratorContext(S, DC);
917 // Rebuild the nested name specifier for the new scope.
918 if (DC->isDependentContext())
919 RebuildNestedNameSpecifierInCurrentInstantiation(SS);
924 /// ActOnCXXExitDeclaratorScope - Called when a declarator that previously
925 /// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same
926 /// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well.
927 /// Used to indicate that names should revert to being looked up in the
929 void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
930 assert(SS.isSet() && "Parser passed invalid CXXScopeSpec.");
933 assert(!SS.isInvalid() && computeDeclContext(SS, true) &&
934 "exiting declarator scope we never really entered");
935 ExitDeclaratorContext(S);