| //===--- SemaCXXScopeSpec.cpp - Semantic Analysis for C++ scope specifiers-===// | 
 | // | 
 | //                     The LLVM Compiler Infrastructure | 
 | // | 
 | // This file is distributed under the University of Illinois Open Source | 
 | // License. See LICENSE.TXT for details. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 | // | 
 | // This file implements C++ semantic analysis for scope specifiers. | 
 | // | 
 | //===----------------------------------------------------------------------===// | 
 |  | 
 | #include "clang/Sema/SemaInternal.h" | 
 | #include "TypeLocBuilder.h" | 
 | #include "clang/AST/ASTContext.h" | 
 | #include "clang/AST/DeclTemplate.h" | 
 | #include "clang/AST/ExprCXX.h" | 
 | #include "clang/AST/NestedNameSpecifier.h" | 
 | #include "clang/Basic/PartialDiagnostic.h" | 
 | #include "clang/Sema/DeclSpec.h" | 
 | #include "clang/Sema/Lookup.h" | 
 | #include "clang/Sema/Template.h" | 
 | #include "llvm/ADT/STLExtras.h" | 
 | #include "llvm/Support/raw_ostream.h" | 
 | using namespace clang; | 
 |  | 
 | /// \brief Find the current instantiation that associated with the given type. | 
 | static CXXRecordDecl *getCurrentInstantiationOf(QualType T, | 
 |                                                 DeclContext *CurContext) { | 
 |   if (T.isNull()) | 
 |     return 0; | 
 |  | 
 |   const Type *Ty = T->getCanonicalTypeInternal().getTypePtr(); | 
 |   if (const RecordType *RecordTy = dyn_cast<RecordType>(Ty)) { | 
 |     CXXRecordDecl *Record = cast<CXXRecordDecl>(RecordTy->getDecl()); | 
 |     if (!Record->isDependentContext() || | 
 |         Record->isCurrentInstantiation(CurContext)) | 
 |       return Record; | 
 |  | 
 |     return 0; | 
 |   } else if (isa<InjectedClassNameType>(Ty)) | 
 |     return cast<InjectedClassNameType>(Ty)->getDecl(); | 
 |   else | 
 |     return 0; | 
 | } | 
 |  | 
 | /// \brief Compute the DeclContext that is associated with the given type. | 
 | /// | 
 | /// \param T the type for which we are attempting to find a DeclContext. | 
 | /// | 
 | /// \returns the declaration context represented by the type T, | 
 | /// or NULL if the declaration context cannot be computed (e.g., because it is | 
 | /// dependent and not the current instantiation). | 
 | DeclContext *Sema::computeDeclContext(QualType T) { | 
 |   if (!T->isDependentType()) | 
 |     if (const TagType *Tag = T->getAs<TagType>()) | 
 |       return Tag->getDecl(); | 
 |  | 
 |   return ::getCurrentInstantiationOf(T, CurContext); | 
 | } | 
 |  | 
 | /// \brief Compute the DeclContext that is associated with the given | 
 | /// scope specifier. | 
 | /// | 
 | /// \param SS the C++ scope specifier as it appears in the source | 
 | /// | 
 | /// \param EnteringContext when true, we will be entering the context of | 
 | /// this scope specifier, so we can retrieve the declaration context of a | 
 | /// class template or class template partial specialization even if it is | 
 | /// not the current instantiation. | 
 | /// | 
 | /// \returns the declaration context represented by the scope specifier @p SS, | 
 | /// or NULL if the declaration context cannot be computed (e.g., because it is | 
 | /// dependent and not the current instantiation). | 
 | DeclContext *Sema::computeDeclContext(const CXXScopeSpec &SS, | 
 |                                       bool EnteringContext) { | 
 |   if (!SS.isSet() || SS.isInvalid()) | 
 |     return 0; | 
 |  | 
 |   NestedNameSpecifier *NNS | 
 |     = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); | 
 |   if (NNS->isDependent()) { | 
 |     // If this nested-name-specifier refers to the current | 
 |     // instantiation, return its DeclContext. | 
 |     if (CXXRecordDecl *Record = getCurrentInstantiationOf(NNS)) | 
 |       return Record; | 
 |  | 
 |     if (EnteringContext) { | 
 |       const Type *NNSType = NNS->getAsType(); | 
 |       if (!NNSType) { | 
 |         return 0; | 
 |       } | 
 |  | 
 |       // Look through type alias templates, per C++0x [temp.dep.type]p1. | 
 |       NNSType = Context.getCanonicalType(NNSType); | 
 |       if (const TemplateSpecializationType *SpecType | 
 |             = NNSType->getAs<TemplateSpecializationType>()) { | 
 |         // We are entering the context of the nested name specifier, so try to | 
 |         // match the nested name specifier to either a primary class template | 
 |         // or a class template partial specialization. | 
 |         if (ClassTemplateDecl *ClassTemplate | 
 |               = dyn_cast_or_null<ClassTemplateDecl>( | 
 |                             SpecType->getTemplateName().getAsTemplateDecl())) { | 
 |           QualType ContextType | 
 |             = Context.getCanonicalType(QualType(SpecType, 0)); | 
 |  | 
 |           // If the type of the nested name specifier is the same as the | 
 |           // injected class name of the named class template, we're entering | 
 |           // into that class template definition. | 
 |           QualType Injected | 
 |             = ClassTemplate->getInjectedClassNameSpecialization(); | 
 |           if (Context.hasSameType(Injected, ContextType)) | 
 |             return ClassTemplate->getTemplatedDecl(); | 
 |  | 
 |           // If the type of the nested name specifier is the same as the | 
 |           // type of one of the class template's class template partial | 
 |           // specializations, we're entering into the definition of that | 
 |           // class template partial specialization. | 
 |           if (ClassTemplatePartialSpecializationDecl *PartialSpec | 
 |                 = ClassTemplate->findPartialSpecialization(ContextType)) | 
 |             return PartialSpec; | 
 |         } | 
 |       } else if (const RecordType *RecordT = NNSType->getAs<RecordType>()) { | 
 |         // The nested name specifier refers to a member of a class template. | 
 |         return RecordT->getDecl(); | 
 |       } | 
 |     } | 
 |  | 
 |     return 0; | 
 |   } | 
 |  | 
 |   switch (NNS->getKind()) { | 
 |   case NestedNameSpecifier::Identifier: | 
 |     llvm_unreachable("Dependent nested-name-specifier has no DeclContext"); | 
 |  | 
 |   case NestedNameSpecifier::Namespace: | 
 |     return NNS->getAsNamespace(); | 
 |  | 
 |   case NestedNameSpecifier::NamespaceAlias: | 
 |     return NNS->getAsNamespaceAlias()->getNamespace(); | 
 |  | 
 |   case NestedNameSpecifier::TypeSpec: | 
 |   case NestedNameSpecifier::TypeSpecWithTemplate: { | 
 |     const TagType *Tag = NNS->getAsType()->getAs<TagType>(); | 
 |     assert(Tag && "Non-tag type in nested-name-specifier"); | 
 |     return Tag->getDecl(); | 
 |   } | 
 |  | 
 |   case NestedNameSpecifier::Global: | 
 |     return Context.getTranslationUnitDecl(); | 
 |   } | 
 |  | 
 |   llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); | 
 | } | 
 |  | 
 | bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { | 
 |   if (!SS.isSet() || SS.isInvalid()) | 
 |     return false; | 
 |  | 
 |   NestedNameSpecifier *NNS | 
 |     = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); | 
 |   return NNS->isDependent(); | 
 | } | 
 |  | 
 | // \brief Determine whether this C++ scope specifier refers to an | 
 | // unknown specialization, i.e., a dependent type that is not the | 
 | // current instantiation. | 
 | bool Sema::isUnknownSpecialization(const CXXScopeSpec &SS) { | 
 |   if (!isDependentScopeSpecifier(SS)) | 
 |     return false; | 
 |  | 
 |   NestedNameSpecifier *NNS | 
 |     = static_cast<NestedNameSpecifier *>(SS.getScopeRep()); | 
 |   return getCurrentInstantiationOf(NNS) == 0; | 
 | } | 
 |  | 
 | /// \brief If the given nested name specifier refers to the current | 
 | /// instantiation, return the declaration that corresponds to that | 
 | /// current instantiation (C++0x [temp.dep.type]p1). | 
 | /// | 
 | /// \param NNS a dependent nested name specifier. | 
 | CXXRecordDecl *Sema::getCurrentInstantiationOf(NestedNameSpecifier *NNS) { | 
 |   assert(getLangOpts().CPlusPlus && "Only callable in C++"); | 
 |   assert(NNS->isDependent() && "Only dependent nested-name-specifier allowed"); | 
 |  | 
 |   if (!NNS->getAsType()) | 
 |     return 0; | 
 |  | 
 |   QualType T = QualType(NNS->getAsType(), 0); | 
 |   return ::getCurrentInstantiationOf(T, CurContext); | 
 | } | 
 |  | 
 | /// \brief Require that the context specified by SS be complete. | 
 | /// | 
 | /// If SS refers to a type, this routine checks whether the type is | 
 | /// complete enough (or can be made complete enough) for name lookup | 
 | /// into the DeclContext. A type that is not yet completed can be | 
 | /// considered "complete enough" if it is a class/struct/union/enum | 
 | /// that is currently being defined. Or, if we have a type that names | 
 | /// a class template specialization that is not a complete type, we | 
 | /// will attempt to instantiate that class template. | 
 | bool Sema::RequireCompleteDeclContext(CXXScopeSpec &SS, | 
 |                                       DeclContext *DC) { | 
 |   assert(DC != 0 && "given null context"); | 
 |  | 
 |   TagDecl *tag = dyn_cast<TagDecl>(DC); | 
 |  | 
 |   // If this is a dependent type, then we consider it complete. | 
 |   if (!tag || tag->isDependentContext()) | 
 |     return false; | 
 |  | 
 |   // If we're currently defining this type, then lookup into the | 
 |   // type is okay: don't complain that it isn't complete yet. | 
 |   QualType type = Context.getTypeDeclType(tag); | 
 |   const TagType *tagType = type->getAs<TagType>(); | 
 |   if (tagType && tagType->isBeingDefined()) | 
 |     return false; | 
 |  | 
 |   SourceLocation loc = SS.getLastQualifierNameLoc(); | 
 |   if (loc.isInvalid()) loc = SS.getRange().getBegin(); | 
 |  | 
 |   // The type must be complete. | 
 |   if (RequireCompleteType(loc, type, diag::err_incomplete_nested_name_spec, | 
 |                           SS.getRange())) { | 
 |     SS.SetInvalid(SS.getRange()); | 
 |     return true; | 
 |   } | 
 |  | 
 |   // Fixed enum types are complete, but they aren't valid as scopes | 
 |   // until we see a definition, so awkwardly pull out this special | 
 |   // case. | 
 |   const EnumType *enumType = dyn_cast_or_null<EnumType>(tagType); | 
 |   if (!enumType || enumType->getDecl()->isCompleteDefinition()) | 
 |     return false; | 
 |  | 
 |   // Try to instantiate the definition, if this is a specialization of an | 
 |   // enumeration temploid. | 
 |   EnumDecl *ED = enumType->getDecl(); | 
 |   if (EnumDecl *Pattern = ED->getInstantiatedFromMemberEnum()) { | 
 |     MemberSpecializationInfo *MSI = ED->getMemberSpecializationInfo(); | 
 |     if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) { | 
 |       if (InstantiateEnum(loc, ED, Pattern, getTemplateInstantiationArgs(ED), | 
 |                           TSK_ImplicitInstantiation)) { | 
 |         SS.SetInvalid(SS.getRange()); | 
 |         return true; | 
 |       } | 
 |       return false; | 
 |     } | 
 |   } | 
 |  | 
 |   Diag(loc, diag::err_incomplete_nested_name_spec) | 
 |     << type << SS.getRange(); | 
 |   SS.SetInvalid(SS.getRange()); | 
 |   return true; | 
 | } | 
 |  | 
 | bool Sema::ActOnCXXGlobalScopeSpecifier(Scope *S, SourceLocation CCLoc, | 
 |                                         CXXScopeSpec &SS) { | 
 |   SS.MakeGlobal(Context, CCLoc); | 
 |   return false; | 
 | } | 
 |  | 
 | /// \brief Determines whether the given declaration is an valid acceptable | 
 | /// result for name lookup of a nested-name-specifier. | 
 | bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD) { | 
 |   if (!SD) | 
 |     return false; | 
 |  | 
 |   // Namespace and namespace aliases are fine. | 
 |   if (isa<NamespaceDecl>(SD) || isa<NamespaceAliasDecl>(SD)) | 
 |     return true; | 
 |  | 
 |   if (!isa<TypeDecl>(SD)) | 
 |     return false; | 
 |  | 
 |   // Determine whether we have a class (or, in C++11, an enum) or | 
 |   // a typedef thereof. If so, build the nested-name-specifier. | 
 |   QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); | 
 |   if (T->isDependentType()) | 
 |     return true; | 
 |   else if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { | 
 |     if (TD->getUnderlyingType()->isRecordType() || | 
 |         (Context.getLangOpts().CPlusPlus11 && | 
 |          TD->getUnderlyingType()->isEnumeralType())) | 
 |       return true; | 
 |   } else if (isa<RecordDecl>(SD) || | 
 |              (Context.getLangOpts().CPlusPlus11 && isa<EnumDecl>(SD))) | 
 |     return true; | 
 |  | 
 |   return false; | 
 | } | 
 |  | 
 | /// \brief If the given nested-name-specifier begins with a bare identifier | 
 | /// (e.g., Base::), perform name lookup for that identifier as a | 
 | /// nested-name-specifier within the given scope, and return the result of that | 
 | /// name lookup. | 
 | NamedDecl *Sema::FindFirstQualifierInScope(Scope *S, NestedNameSpecifier *NNS) { | 
 |   if (!S || !NNS) | 
 |     return 0; | 
 |  | 
 |   while (NNS->getPrefix()) | 
 |     NNS = NNS->getPrefix(); | 
 |  | 
 |   if (NNS->getKind() != NestedNameSpecifier::Identifier) | 
 |     return 0; | 
 |  | 
 |   LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), | 
 |                      LookupNestedNameSpecifierName); | 
 |   LookupName(Found, S); | 
 |   assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); | 
 |  | 
 |   if (!Found.isSingleResult()) | 
 |     return 0; | 
 |  | 
 |   NamedDecl *Result = Found.getFoundDecl(); | 
 |   if (isAcceptableNestedNameSpecifier(Result)) | 
 |     return Result; | 
 |  | 
 |   return 0; | 
 | } | 
 |  | 
 | bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, | 
 |                                         SourceLocation IdLoc, | 
 |                                         IdentifierInfo &II, | 
 |                                         ParsedType ObjectTypePtr) { | 
 |   QualType ObjectType = GetTypeFromParser(ObjectTypePtr); | 
 |   LookupResult Found(*this, &II, IdLoc, LookupNestedNameSpecifierName); | 
 |    | 
 |   // Determine where to perform name lookup | 
 |   DeclContext *LookupCtx = 0; | 
 |   bool isDependent = false; | 
 |   if (!ObjectType.isNull()) { | 
 |     // This nested-name-specifier occurs in a member access expression, e.g., | 
 |     // x->B::f, and we are looking into the type of the object. | 
 |     assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); | 
 |     LookupCtx = computeDeclContext(ObjectType); | 
 |     isDependent = ObjectType->isDependentType(); | 
 |   } else if (SS.isSet()) { | 
 |     // This nested-name-specifier occurs after another nested-name-specifier, | 
 |     // so long into the context associated with the prior nested-name-specifier. | 
 |     LookupCtx = computeDeclContext(SS, false); | 
 |     isDependent = isDependentScopeSpecifier(SS); | 
 |     Found.setContextRange(SS.getRange()); | 
 |   } | 
 |    | 
 |   if (LookupCtx) { | 
 |     // Perform "qualified" name lookup into the declaration context we | 
 |     // computed, which is either the type of the base of a member access | 
 |     // expression or the declaration context associated with a prior | 
 |     // nested-name-specifier. | 
 |      | 
 |     // The declaration context must be complete. | 
 |     if (!LookupCtx->isDependentContext() && | 
 |         RequireCompleteDeclContext(SS, LookupCtx)) | 
 |       return false; | 
 |      | 
 |     LookupQualifiedName(Found, LookupCtx); | 
 |   } else if (isDependent) { | 
 |     return false; | 
 |   } else { | 
 |     LookupName(Found, S); | 
 |   } | 
 |   Found.suppressDiagnostics(); | 
 |    | 
 |   if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) | 
 |     return isa<NamespaceDecl>(ND) || isa<NamespaceAliasDecl>(ND); | 
 |    | 
 |   return false; | 
 | } | 
 |  | 
 | namespace { | 
 |  | 
 | // Callback to only accept typo corrections that can be a valid C++ member | 
 | // intializer: either a non-static field member or a base class. | 
 | class NestedNameSpecifierValidatorCCC : public CorrectionCandidateCallback { | 
 |  public: | 
 |   explicit NestedNameSpecifierValidatorCCC(Sema &SRef) | 
 |       : SRef(SRef) {} | 
 |  | 
 |   virtual bool ValidateCandidate(const TypoCorrection &candidate) { | 
 |     return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl()); | 
 |   } | 
 |  | 
 |  private: | 
 |   Sema &SRef; | 
 | }; | 
 |  | 
 | } | 
 |  | 
 | /// \brief Build a new nested-name-specifier for "identifier::", as described | 
 | /// by ActOnCXXNestedNameSpecifier. | 
 | /// | 
 | /// This routine differs only slightly from ActOnCXXNestedNameSpecifier, in | 
 | /// that it contains an extra parameter \p ScopeLookupResult, which provides | 
 | /// the result of name lookup within the scope of the nested-name-specifier | 
 | /// that was computed at template definition time. | 
 | /// | 
 | /// If ErrorRecoveryLookup is true, then this call is used to improve error | 
 | /// recovery.  This means that it should not emit diagnostics, it should | 
 | /// just return true on failure.  It also means it should only return a valid | 
 | /// scope if it *knows* that the result is correct.  It should not return in a | 
 | /// dependent context, for example. Nor will it extend \p SS with the scope | 
 | /// specifier. | 
 | bool Sema::BuildCXXNestedNameSpecifier(Scope *S, | 
 |                                        IdentifierInfo &Identifier, | 
 |                                        SourceLocation IdentifierLoc, | 
 |                                        SourceLocation CCLoc, | 
 |                                        QualType ObjectType, | 
 |                                        bool EnteringContext, | 
 |                                        CXXScopeSpec &SS, | 
 |                                        NamedDecl *ScopeLookupResult, | 
 |                                        bool ErrorRecoveryLookup) { | 
 |   LookupResult Found(*this, &Identifier, IdentifierLoc,  | 
 |                      LookupNestedNameSpecifierName); | 
 |  | 
 |   // Determine where to perform name lookup | 
 |   DeclContext *LookupCtx = 0; | 
 |   bool isDependent = false; | 
 |   if (!ObjectType.isNull()) { | 
 |     // This nested-name-specifier occurs in a member access expression, e.g., | 
 |     // x->B::f, and we are looking into the type of the object. | 
 |     assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist"); | 
 |     LookupCtx = computeDeclContext(ObjectType); | 
 |     isDependent = ObjectType->isDependentType(); | 
 |   } else if (SS.isSet()) { | 
 |     // This nested-name-specifier occurs after another nested-name-specifier, | 
 |     // so look into the context associated with the prior nested-name-specifier. | 
 |     LookupCtx = computeDeclContext(SS, EnteringContext); | 
 |     isDependent = isDependentScopeSpecifier(SS); | 
 |     Found.setContextRange(SS.getRange()); | 
 |   } | 
 |  | 
 |  | 
 |   bool ObjectTypeSearchedInScope = false; | 
 |   if (LookupCtx) { | 
 |     // Perform "qualified" name lookup into the declaration context we | 
 |     // computed, which is either the type of the base of a member access | 
 |     // expression or the declaration context associated with a prior | 
 |     // nested-name-specifier. | 
 |  | 
 |     // The declaration context must be complete. | 
 |     if (!LookupCtx->isDependentContext() && | 
 |         RequireCompleteDeclContext(SS, LookupCtx)) | 
 |       return true; | 
 |  | 
 |     LookupQualifiedName(Found, LookupCtx); | 
 |  | 
 |     if (!ObjectType.isNull() && Found.empty()) { | 
 |       // C++ [basic.lookup.classref]p4: | 
 |       //   If the id-expression in a class member access is a qualified-id of | 
 |       //   the form | 
 |       // | 
 |       //        class-name-or-namespace-name::... | 
 |       // | 
 |       //   the class-name-or-namespace-name following the . or -> operator is | 
 |       //   looked up both in the context of the entire postfix-expression and in | 
 |       //   the scope of the class of the object expression. If the name is found | 
 |       //   only in the scope of the class of the object expression, the name | 
 |       //   shall refer to a class-name. If the name is found only in the | 
 |       //   context of the entire postfix-expression, the name shall refer to a | 
 |       //   class-name or namespace-name. [...] | 
 |       // | 
 |       // Qualified name lookup into a class will not find a namespace-name, | 
 |       // so we do not need to diagnose that case specifically. However, | 
 |       // this qualified name lookup may find nothing. In that case, perform | 
 |       // unqualified name lookup in the given scope (if available) or | 
 |       // reconstruct the result from when name lookup was performed at template | 
 |       // definition time. | 
 |       if (S) | 
 |         LookupName(Found, S); | 
 |       else if (ScopeLookupResult) | 
 |         Found.addDecl(ScopeLookupResult); | 
 |  | 
 |       ObjectTypeSearchedInScope = true; | 
 |     } | 
 |   } else if (!isDependent) { | 
 |     // Perform unqualified name lookup in the current scope. | 
 |     LookupName(Found, S); | 
 |   } | 
 |  | 
 |   // If we performed lookup into a dependent context and did not find anything, | 
 |   // that's fine: just build a dependent nested-name-specifier. | 
 |   if (Found.empty() && isDependent && | 
 |       !(LookupCtx && LookupCtx->isRecord() && | 
 |         (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() || | 
 |          !cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases()))) { | 
 |     // Don't speculate if we're just trying to improve error recovery. | 
 |     if (ErrorRecoveryLookup) | 
 |       return true; | 
 |      | 
 |     // We were not able to compute the declaration context for a dependent | 
 |     // base object type or prior nested-name-specifier, so this | 
 |     // nested-name-specifier refers to an unknown specialization. Just build | 
 |     // a dependent nested-name-specifier. | 
 |     SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); | 
 |     return false; | 
 |   }  | 
 |    | 
 |   // FIXME: Deal with ambiguities cleanly. | 
 |  | 
 |   if (Found.empty() && !ErrorRecoveryLookup) { | 
 |     // We haven't found anything, and we're not recovering from a | 
 |     // different kind of error, so look for typos. | 
 |     DeclarationName Name = Found.getLookupName(); | 
 |     NestedNameSpecifierValidatorCCC Validator(*this); | 
 |     TypoCorrection Corrected; | 
 |     Found.clear(); | 
 |     if ((Corrected = CorrectTypo(Found.getLookupNameInfo(), | 
 |                                  Found.getLookupKind(), S, &SS, Validator, | 
 |                                  LookupCtx, EnteringContext))) { | 
 |       std::string CorrectedStr(Corrected.getAsString(getLangOpts())); | 
 |       std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOpts())); | 
 |       if (LookupCtx) | 
 |         Diag(Found.getNameLoc(), diag::err_no_member_suggest) | 
 |           << Name << LookupCtx << CorrectedQuotedStr << SS.getRange() | 
 |           << FixItHint::CreateReplacement(Corrected.getCorrectionRange(), | 
 |                                           CorrectedStr); | 
 |       else | 
 |         Diag(Found.getNameLoc(), diag::err_undeclared_var_use_suggest) | 
 |           << Name << CorrectedQuotedStr | 
 |           << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr); | 
 |        | 
 |       if (NamedDecl *ND = Corrected.getCorrectionDecl()) { | 
 |         Diag(ND->getLocation(), diag::note_previous_decl) << CorrectedQuotedStr; | 
 |         Found.addDecl(ND); | 
 |       } | 
 |       Found.setLookupName(Corrected.getCorrection()); | 
 |     } else { | 
 |       Found.setLookupName(&Identifier); | 
 |     } | 
 |   } | 
 |  | 
 |   NamedDecl *SD = Found.getAsSingle<NamedDecl>(); | 
 |   if (isAcceptableNestedNameSpecifier(SD)) { | 
 |     if (!ObjectType.isNull() && !ObjectTypeSearchedInScope && | 
 |         !getLangOpts().CPlusPlus11) { | 
 |       // C++03 [basic.lookup.classref]p4: | 
 |       //   [...] If the name is found in both contexts, the | 
 |       //   class-name-or-namespace-name shall refer to the same entity. | 
 |       // | 
 |       // We already found the name in the scope of the object. Now, look | 
 |       // into the current scope (the scope of the postfix-expression) to | 
 |       // see if we can find the same name there. As above, if there is no | 
 |       // scope, reconstruct the result from the template instantiation itself. | 
 |       // | 
 |       // Note that C++11 does *not* perform this redundant lookup. | 
 |       NamedDecl *OuterDecl; | 
 |       if (S) { | 
 |         LookupResult FoundOuter(*this, &Identifier, IdentifierLoc,  | 
 |                                 LookupNestedNameSpecifierName); | 
 |         LookupName(FoundOuter, S); | 
 |         OuterDecl = FoundOuter.getAsSingle<NamedDecl>(); | 
 |       } else | 
 |         OuterDecl = ScopeLookupResult; | 
 |  | 
 |       if (isAcceptableNestedNameSpecifier(OuterDecl) && | 
 |           OuterDecl->getCanonicalDecl() != SD->getCanonicalDecl() && | 
 |           (!isa<TypeDecl>(OuterDecl) || !isa<TypeDecl>(SD) || | 
 |            !Context.hasSameType( | 
 |                             Context.getTypeDeclType(cast<TypeDecl>(OuterDecl)), | 
 |                                Context.getTypeDeclType(cast<TypeDecl>(SD))))) { | 
 |          if (ErrorRecoveryLookup) | 
 |            return true; | 
 |  | 
 |          Diag(IdentifierLoc,  | 
 |               diag::err_nested_name_member_ref_lookup_ambiguous) | 
 |            << &Identifier; | 
 |          Diag(SD->getLocation(), diag::note_ambig_member_ref_object_type) | 
 |            << ObjectType; | 
 |          Diag(OuterDecl->getLocation(), diag::note_ambig_member_ref_scope); | 
 |  | 
 |          // Fall through so that we'll pick the name we found in the object | 
 |          // type, since that's probably what the user wanted anyway. | 
 |        } | 
 |     } | 
 |  | 
 |     // If we're just performing this lookup for error-recovery purposes,  | 
 |     // don't extend the nested-name-specifier. Just return now. | 
 |     if (ErrorRecoveryLookup) | 
 |       return false; | 
 |      | 
 |     if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { | 
 |       SS.Extend(Context, Namespace, IdentifierLoc, CCLoc); | 
 |       return false; | 
 |     } | 
 |  | 
 |     if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { | 
 |       SS.Extend(Context, Alias, IdentifierLoc, CCLoc); | 
 |       return false; | 
 |     } | 
 |  | 
 |     QualType T = Context.getTypeDeclType(cast<TypeDecl>(SD)); | 
 |     TypeLocBuilder TLB; | 
 |     if (isa<InjectedClassNameType>(T)) { | 
 |       InjectedClassNameTypeLoc InjectedTL | 
 |         = TLB.push<InjectedClassNameTypeLoc>(T); | 
 |       InjectedTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<RecordType>(T)) { | 
 |       RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); | 
 |       RecordTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<TypedefType>(T)) { | 
 |       TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); | 
 |       TypedefTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<EnumType>(T)) { | 
 |       EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); | 
 |       EnumTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<TemplateTypeParmType>(T)) { | 
 |       TemplateTypeParmTypeLoc TemplateTypeTL | 
 |         = TLB.push<TemplateTypeParmTypeLoc>(T); | 
 |       TemplateTypeTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<UnresolvedUsingType>(T)) { | 
 |       UnresolvedUsingTypeLoc UnresolvedTL | 
 |         = TLB.push<UnresolvedUsingTypeLoc>(T); | 
 |       UnresolvedTL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<SubstTemplateTypeParmType>(T)) { | 
 |       SubstTemplateTypeParmTypeLoc TL  | 
 |         = TLB.push<SubstTemplateTypeParmTypeLoc>(T); | 
 |       TL.setNameLoc(IdentifierLoc); | 
 |     } else if (isa<SubstTemplateTypeParmPackType>(T)) { | 
 |       SubstTemplateTypeParmPackTypeLoc TL | 
 |         = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); | 
 |       TL.setNameLoc(IdentifierLoc); | 
 |     } else { | 
 |       llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); | 
 |     } | 
 |  | 
 |     if (T->isEnumeralType()) | 
 |       Diag(IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec); | 
 |  | 
 |     SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), | 
 |               CCLoc); | 
 |     return false; | 
 |   } | 
 |  | 
 |   // Otherwise, we have an error case.  If we don't want diagnostics, just | 
 |   // return an error now. | 
 |   if (ErrorRecoveryLookup) | 
 |     return true; | 
 |  | 
 |   // If we didn't find anything during our lookup, try again with | 
 |   // ordinary name lookup, which can help us produce better error | 
 |   // messages. | 
 |   if (Found.empty()) { | 
 |     Found.clear(LookupOrdinaryName); | 
 |     LookupName(Found, S); | 
 |   } | 
 |  | 
 |   // In Microsoft mode, if we are within a templated function and we can't | 
 |   // resolve Identifier, then extend the SS with Identifier. This will have  | 
 |   // the effect of resolving Identifier during template instantiation.  | 
 |   // The goal is to be able to resolve a function call whose | 
 |   // nested-name-specifier is located inside a dependent base class. | 
 |   // Example:  | 
 |   // | 
 |   // class C { | 
 |   // public: | 
 |   //    static void foo2() {  } | 
 |   // }; | 
 |   // template <class T> class A { public: typedef C D; }; | 
 |   // | 
 |   // template <class T> class B : public A<T> { | 
 |   // public: | 
 |   //   void foo() { D::foo2(); } | 
 |   // }; | 
 |   if (getLangOpts().MicrosoftExt) { | 
 |     DeclContext *DC = LookupCtx ? LookupCtx : CurContext; | 
 |     if (DC->isDependentContext() && DC->isFunctionOrMethod()) { | 
 |       SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc); | 
 |       return false; | 
 |     } | 
 |   } | 
 |  | 
 |   unsigned DiagID; | 
 |   if (!Found.empty()) | 
 |     DiagID = diag::err_expected_class_or_namespace; | 
 |   else if (SS.isSet()) { | 
 |     Diag(IdentifierLoc, diag::err_no_member)  | 
 |       << &Identifier << LookupCtx << SS.getRange(); | 
 |     return true; | 
 |   } else | 
 |     DiagID = diag::err_undeclared_var_use; | 
 |  | 
 |   if (SS.isSet()) | 
 |     Diag(IdentifierLoc, DiagID) << &Identifier << SS.getRange(); | 
 |   else | 
 |     Diag(IdentifierLoc, DiagID) << &Identifier; | 
 |  | 
 |   return true; | 
 | } | 
 |  | 
 | bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, | 
 |                                        IdentifierInfo &Identifier, | 
 |                                        SourceLocation IdentifierLoc, | 
 |                                        SourceLocation CCLoc, | 
 |                                        ParsedType ObjectType, | 
 |                                        bool EnteringContext, | 
 |                                        CXXScopeSpec &SS) { | 
 |   if (SS.isInvalid()) | 
 |     return true; | 
 |    | 
 |   return BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, CCLoc, | 
 |                                      GetTypeFromParser(ObjectType), | 
 |                                      EnteringContext, SS,  | 
 |                                      /*ScopeLookupResult=*/0, false); | 
 | } | 
 |  | 
 | bool Sema::ActOnCXXNestedNameSpecifierDecltype(CXXScopeSpec &SS, | 
 |                                                const DeclSpec &DS, | 
 |                                                SourceLocation ColonColonLoc) { | 
 |   if (SS.isInvalid() || DS.getTypeSpecType() == DeclSpec::TST_error) | 
 |     return true; | 
 |  | 
 |   assert(DS.getTypeSpecType() == DeclSpec::TST_decltype); | 
 |  | 
 |   QualType T = BuildDecltypeType(DS.getRepAsExpr(), DS.getTypeSpecTypeLoc()); | 
 |   if (!T->isDependentType() && !T->getAs<TagType>()) { | 
 |     Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class)  | 
 |       << T << getLangOpts().CPlusPlus; | 
 |     return true; | 
 |   } | 
 |  | 
 |   TypeLocBuilder TLB; | 
 |   DecltypeTypeLoc DecltypeTL = TLB.push<DecltypeTypeLoc>(T); | 
 |   DecltypeTL.setNameLoc(DS.getTypeSpecTypeLoc()); | 
 |   SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), | 
 |             ColonColonLoc); | 
 |   return false; | 
 | } | 
 |  | 
 | /// IsInvalidUnlessNestedName - This method is used for error recovery | 
 | /// purposes to determine whether the specified identifier is only valid as | 
 | /// a nested name specifier, for example a namespace name.  It is | 
 | /// conservatively correct to always return false from this method. | 
 | /// | 
 | /// The arguments are the same as those passed to ActOnCXXNestedNameSpecifier. | 
 | bool Sema::IsInvalidUnlessNestedName(Scope *S, CXXScopeSpec &SS, | 
 |                                      IdentifierInfo &Identifier,  | 
 |                                      SourceLocation IdentifierLoc, | 
 |                                      SourceLocation ColonLoc, | 
 |                                      ParsedType ObjectType, | 
 |                                      bool EnteringContext) { | 
 |   if (SS.isInvalid()) | 
 |     return false; | 
 |    | 
 |   return !BuildCXXNestedNameSpecifier(S, Identifier, IdentifierLoc, ColonLoc, | 
 |                                       GetTypeFromParser(ObjectType), | 
 |                                       EnteringContext, SS,  | 
 |                                       /*ScopeLookupResult=*/0, true); | 
 | } | 
 |  | 
 | bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, | 
 |                                        CXXScopeSpec &SS, | 
 |                                        SourceLocation TemplateKWLoc, | 
 |                                        TemplateTy Template, | 
 |                                        SourceLocation TemplateNameLoc, | 
 |                                        SourceLocation LAngleLoc, | 
 |                                        ASTTemplateArgsPtr TemplateArgsIn, | 
 |                                        SourceLocation RAngleLoc, | 
 |                                        SourceLocation CCLoc, | 
 |                                        bool EnteringContext) { | 
 |   if (SS.isInvalid()) | 
 |     return true; | 
 |    | 
 |   // Translate the parser's template argument list in our AST format. | 
 |   TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); | 
 |   translateTemplateArguments(TemplateArgsIn, TemplateArgs); | 
 |  | 
 |   if (DependentTemplateName *DTN = Template.get().getAsDependentTemplateName()){ | 
 |     // Handle a dependent template specialization for which we cannot resolve | 
 |     // the template name. | 
 |     assert(DTN->getQualifier() | 
 |              == static_cast<NestedNameSpecifier*>(SS.getScopeRep())); | 
 |     QualType T = Context.getDependentTemplateSpecializationType(ETK_None, | 
 |                                                           DTN->getQualifier(), | 
 |                                                           DTN->getIdentifier(), | 
 |                                                                 TemplateArgs); | 
 |      | 
 |     // Create source-location information for this type. | 
 |     TypeLocBuilder Builder; | 
 |     DependentTemplateSpecializationTypeLoc SpecTL | 
 |       = Builder.push<DependentTemplateSpecializationTypeLoc>(T); | 
 |     SpecTL.setElaboratedKeywordLoc(SourceLocation()); | 
 |     SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); | 
 |     SpecTL.setTemplateKeywordLoc(TemplateKWLoc); | 
 |     SpecTL.setTemplateNameLoc(TemplateNameLoc); | 
 |     SpecTL.setLAngleLoc(LAngleLoc); | 
 |     SpecTL.setRAngleLoc(RAngleLoc); | 
 |     for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) | 
 |       SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); | 
 |      | 
 |     SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), | 
 |               CCLoc); | 
 |     return false; | 
 |   } | 
 |    | 
 |    | 
 |   if (Template.get().getAsOverloadedTemplate() || | 
 |       isa<FunctionTemplateDecl>(Template.get().getAsTemplateDecl())) { | 
 |     SourceRange R(TemplateNameLoc, RAngleLoc); | 
 |     if (SS.getRange().isValid()) | 
 |       R.setBegin(SS.getRange().getBegin()); | 
 |        | 
 |     Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) | 
 |       << Template.get() << R; | 
 |     NoteAllFoundTemplates(Template.get()); | 
 |     return true; | 
 |   } | 
 |                                  | 
 |   // We were able to resolve the template name to an actual template.  | 
 |   // Build an appropriate nested-name-specifier. | 
 |   QualType T = CheckTemplateIdType(Template.get(), TemplateNameLoc,  | 
 |                                    TemplateArgs); | 
 |   if (T.isNull()) | 
 |     return true; | 
 |  | 
 |   // Alias template specializations can produce types which are not valid | 
 |   // nested name specifiers. | 
 |   if (!T->isDependentType() && !T->getAs<TagType>()) { | 
 |     Diag(TemplateNameLoc, diag::err_nested_name_spec_non_tag) << T; | 
 |     NoteAllFoundTemplates(Template.get()); | 
 |     return true; | 
 |   } | 
 |  | 
 |   // Provide source-location information for the template specialization type. | 
 |   TypeLocBuilder Builder; | 
 |   TemplateSpecializationTypeLoc SpecTL | 
 |     = Builder.push<TemplateSpecializationTypeLoc>(T); | 
 |   SpecTL.setTemplateKeywordLoc(TemplateKWLoc); | 
 |   SpecTL.setTemplateNameLoc(TemplateNameLoc); | 
 |   SpecTL.setLAngleLoc(LAngleLoc); | 
 |   SpecTL.setRAngleLoc(RAngleLoc); | 
 |   for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) | 
 |     SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); | 
 |  | 
 |  | 
 |   SS.Extend(Context, TemplateKWLoc, Builder.getTypeLocInContext(Context, T), | 
 |             CCLoc); | 
 |   return false; | 
 | } | 
 |  | 
 | namespace { | 
 |   /// \brief A structure that stores a nested-name-specifier annotation, | 
 |   /// including both the nested-name-specifier  | 
 |   struct NestedNameSpecifierAnnotation { | 
 |     NestedNameSpecifier *NNS; | 
 |   }; | 
 | } | 
 |  | 
 | void *Sema::SaveNestedNameSpecifierAnnotation(CXXScopeSpec &SS) { | 
 |   if (SS.isEmpty() || SS.isInvalid()) | 
 |     return 0; | 
 |    | 
 |   void *Mem = Context.Allocate((sizeof(NestedNameSpecifierAnnotation) + | 
 |                                                         SS.location_size()), | 
 |                                llvm::alignOf<NestedNameSpecifierAnnotation>()); | 
 |   NestedNameSpecifierAnnotation *Annotation | 
 |     = new (Mem) NestedNameSpecifierAnnotation; | 
 |   Annotation->NNS = SS.getScopeRep(); | 
 |   memcpy(Annotation + 1, SS.location_data(), SS.location_size()); | 
 |   return Annotation; | 
 | } | 
 |  | 
 | void Sema::RestoreNestedNameSpecifierAnnotation(void *AnnotationPtr,  | 
 |                                                 SourceRange AnnotationRange, | 
 |                                                 CXXScopeSpec &SS) { | 
 |   if (!AnnotationPtr) { | 
 |     SS.SetInvalid(AnnotationRange); | 
 |     return; | 
 |   } | 
 |    | 
 |   NestedNameSpecifierAnnotation *Annotation | 
 |     = static_cast<NestedNameSpecifierAnnotation *>(AnnotationPtr); | 
 |   SS.Adopt(NestedNameSpecifierLoc(Annotation->NNS, Annotation + 1)); | 
 | } | 
 |  | 
 | bool Sema::ShouldEnterDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { | 
 |   assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); | 
 |  | 
 |   NestedNameSpecifier *Qualifier = | 
 |     static_cast<NestedNameSpecifier*>(SS.getScopeRep()); | 
 |  | 
 |   // There are only two places a well-formed program may qualify a | 
 |   // declarator: first, when defining a namespace or class member | 
 |   // out-of-line, and second, when naming an explicitly-qualified | 
 |   // friend function.  The latter case is governed by | 
 |   // C++03 [basic.lookup.unqual]p10: | 
 |   //   In a friend declaration naming a member function, a name used | 
 |   //   in the function declarator and not part of a template-argument | 
 |   //   in a template-id is first looked up in the scope of the member | 
 |   //   function's class. If it is not found, or if the name is part of | 
 |   //   a template-argument in a template-id, the look up is as | 
 |   //   described for unqualified names in the definition of the class | 
 |   //   granting friendship. | 
 |   // i.e. we don't push a scope unless it's a class member. | 
 |  | 
 |   switch (Qualifier->getKind()) { | 
 |   case NestedNameSpecifier::Global: | 
 |   case NestedNameSpecifier::Namespace: | 
 |   case NestedNameSpecifier::NamespaceAlias: | 
 |     // These are always namespace scopes.  We never want to enter a | 
 |     // namespace scope from anything but a file context. | 
 |     return CurContext->getRedeclContext()->isFileContext(); | 
 |  | 
 |   case NestedNameSpecifier::Identifier: | 
 |   case NestedNameSpecifier::TypeSpec: | 
 |   case NestedNameSpecifier::TypeSpecWithTemplate: | 
 |     // These are never namespace scopes. | 
 |     return true; | 
 |   } | 
 |  | 
 |   llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); | 
 | } | 
 |  | 
 | /// ActOnCXXEnterDeclaratorScope - Called when a C++ scope specifier (global | 
 | /// scope or nested-name-specifier) is parsed, part of a declarator-id. | 
 | /// After this method is called, according to [C++ 3.4.3p3], names should be | 
 | /// looked up in the declarator-id's scope, until the declarator is parsed and | 
 | /// ActOnCXXExitDeclaratorScope is called. | 
 | /// The 'SS' should be a non-empty valid CXXScopeSpec. | 
 | bool Sema::ActOnCXXEnterDeclaratorScope(Scope *S, CXXScopeSpec &SS) { | 
 |   assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); | 
 |  | 
 |   if (SS.isInvalid()) return true; | 
 |  | 
 |   DeclContext *DC = computeDeclContext(SS, true); | 
 |   if (!DC) return true; | 
 |  | 
 |   // Before we enter a declarator's context, we need to make sure that | 
 |   // it is a complete declaration context. | 
 |   if (!DC->isDependentContext() && RequireCompleteDeclContext(SS, DC)) | 
 |     return true; | 
 |      | 
 |   EnterDeclaratorContext(S, DC); | 
 |  | 
 |   // Rebuild the nested name specifier for the new scope. | 
 |   if (DC->isDependentContext()) | 
 |     RebuildNestedNameSpecifierInCurrentInstantiation(SS); | 
 |  | 
 |   return false; | 
 | } | 
 |  | 
 | /// ActOnCXXExitDeclaratorScope - Called when a declarator that previously | 
 | /// invoked ActOnCXXEnterDeclaratorScope(), is finished. 'SS' is the same | 
 | /// CXXScopeSpec that was passed to ActOnCXXEnterDeclaratorScope as well. | 
 | /// Used to indicate that names should revert to being looked up in the | 
 | /// defining scope. | 
 | void Sema::ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) { | 
 |   assert(SS.isSet() && "Parser passed invalid CXXScopeSpec."); | 
 |   if (SS.isInvalid()) | 
 |     return; | 
 |   assert(!SS.isInvalid() && computeDeclContext(SS, true) && | 
 |          "exiting declarator scope we never really entered"); | 
 |   ExitDeclaratorContext(S); | 
 | } |