| //===--- SemaCXXScopeSpec.cpp - Semantic Analysis for C++ scope specifiers-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements C++ semantic analysis for scope specifiers. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #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/SemaInternal.h" |
| #include "clang/Sema/Template.h" |
| #include "llvm/ADT/STLExtras.h" |
| using namespace clang; |
| |
| /// Find the current instantiation that associated with the given type. |
| static CXXRecordDecl *getCurrentInstantiationOf(QualType T, |
| DeclContext *CurContext) { |
| if (T.isNull()) |
| return nullptr; |
| |
| 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 nullptr; |
| } else if (isa<InjectedClassNameType>(Ty)) |
| return cast<InjectedClassNameType>(Ty)->getDecl(); |
| else |
| return nullptr; |
| } |
| |
| /// 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); |
| } |
| |
| /// 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 nullptr; |
| |
| NestedNameSpecifier *NNS = 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 nullptr; |
| } |
| |
| // 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)) { |
| // A declaration of the partial specialization must be visible. |
| // We can always recover here, because this only happens when we're |
| // entering the context, and that can't happen in a SFINAE context. |
| assert(!isSFINAEContext() && |
| "partial specialization scope specifier in SFINAE context?"); |
| if (!hasVisibleDeclaration(PartialSpec)) |
| diagnoseMissingImport(SS.getLastQualifierNameLoc(), PartialSpec, |
| MissingImportKind::PartialSpecialization, |
| /*Recover*/true); |
| 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 nullptr; |
| } |
| |
| 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(); |
| |
| case NestedNameSpecifier::Super: |
| return NNS->getAsRecordDecl(); |
| } |
| |
| llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); |
| } |
| |
| bool Sema::isDependentScopeSpecifier(const CXXScopeSpec &SS) { |
| if (!SS.isSet() || SS.isInvalid()) |
| return false; |
| |
| return SS.getScopeRep()->isDependent(); |
| } |
| |
| /// 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 nullptr; |
| |
| QualType T = QualType(NNS->getAsType(), 0); |
| return ::getCurrentInstantiationOf(T, CurContext); |
| } |
| |
| /// 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 && "given null context"); |
| |
| TagDecl *tag = dyn_cast<TagDecl>(DC); |
| |
| // If this is a dependent type, then we consider it complete. |
| // FIXME: This is wrong; we should require a (visible) definition to |
| // exist in this case too. |
| if (!tag || tag->isDependentContext()) |
| return false; |
| |
| // Grab the tag definition, if there is one. |
| QualType type = Context.getTypeDeclType(tag); |
| tag = type->getAsTagDecl(); |
| |
| // If we're currently defining this type, then lookup into the |
| // type is okay: don't complain that it isn't complete yet. |
| if (tag->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; |
| } |
| |
| if (auto *EnumD = dyn_cast<EnumDecl>(tag)) |
| // Fixed enum types and scoped enum instantiations are complete, but they |
| // aren't valid as scopes until we see or instantiate their definition. |
| return RequireCompleteEnumDecl(EnumD, loc, &SS); |
| |
| return false; |
| } |
| |
| /// Require that the EnumDecl is completed with its enumerators defined or |
| /// instantiated. SS, if provided, is the ScopeRef parsed. |
| /// |
| bool Sema::RequireCompleteEnumDecl(EnumDecl *EnumD, SourceLocation L, |
| CXXScopeSpec *SS) { |
| if (EnumD->isCompleteDefinition()) { |
| // If we know about the definition but it is not visible, complain. |
| NamedDecl *SuggestedDef = nullptr; |
| if (!hasVisibleDefinition(EnumD, &SuggestedDef, |
| /*OnlyNeedComplete*/false)) { |
| // If the user is going to see an error here, recover by making the |
| // definition visible. |
| bool TreatAsComplete = !isSFINAEContext(); |
| diagnoseMissingImport(L, SuggestedDef, MissingImportKind::Definition, |
| /*Recover*/ TreatAsComplete); |
| return !TreatAsComplete; |
| } |
| return false; |
| } |
| |
| // Try to instantiate the definition, if this is a specialization of an |
| // enumeration temploid. |
| if (EnumDecl *Pattern = EnumD->getInstantiatedFromMemberEnum()) { |
| MemberSpecializationInfo *MSI = EnumD->getMemberSpecializationInfo(); |
| if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization) { |
| if (InstantiateEnum(L, EnumD, Pattern, |
| getTemplateInstantiationArgs(EnumD), |
| TSK_ImplicitInstantiation)) { |
| if (SS) |
| SS->SetInvalid(SS->getRange()); |
| return true; |
| } |
| return false; |
| } |
| } |
| |
| if (SS) { |
| Diag(L, diag::err_incomplete_nested_name_spec) |
| << QualType(EnumD->getTypeForDecl(), 0) << SS->getRange(); |
| SS->SetInvalid(SS->getRange()); |
| } else { |
| Diag(L, diag::err_incomplete_enum) << QualType(EnumD->getTypeForDecl(), 0); |
| Diag(EnumD->getLocation(), diag::note_declared_at); |
| } |
| |
| return true; |
| } |
| |
| bool Sema::ActOnCXXGlobalScopeSpecifier(SourceLocation CCLoc, |
| CXXScopeSpec &SS) { |
| SS.MakeGlobal(Context, CCLoc); |
| return false; |
| } |
| |
| bool Sema::ActOnSuperScopeSpecifier(SourceLocation SuperLoc, |
| SourceLocation ColonColonLoc, |
| CXXScopeSpec &SS) { |
| CXXRecordDecl *RD = nullptr; |
| for (Scope *S = getCurScope(); S; S = S->getParent()) { |
| if (S->isFunctionScope()) { |
| if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(S->getEntity())) |
| RD = MD->getParent(); |
| break; |
| } |
| if (S->isClassScope()) { |
| RD = cast<CXXRecordDecl>(S->getEntity()); |
| break; |
| } |
| } |
| |
| if (!RD) { |
| Diag(SuperLoc, diag::err_invalid_super_scope); |
| return true; |
| } else if (RD->isLambda()) { |
| Diag(SuperLoc, diag::err_super_in_lambda_unsupported); |
| return true; |
| } else if (RD->getNumBases() == 0) { |
| Diag(SuperLoc, diag::err_no_base_classes) << RD->getName(); |
| return true; |
| } |
| |
| SS.MakeSuper(Context, RD, SuperLoc, ColonColonLoc); |
| return false; |
| } |
| |
| /// Determines whether the given declaration is an valid acceptable |
| /// result for name lookup of a nested-name-specifier. |
| /// \param SD Declaration checked for nested-name-specifier. |
| /// \param IsExtension If not null and the declaration is accepted as an |
| /// extension, the pointed variable is assigned true. |
| bool Sema::isAcceptableNestedNameSpecifier(const NamedDecl *SD, |
| bool *IsExtension) { |
| if (!SD) |
| return false; |
| |
| SD = SD->getUnderlyingDecl(); |
| |
| // Namespace and namespace aliases are fine. |
| if (isa<NamespaceDecl>(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; |
| if (const TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(SD)) { |
| if (TD->getUnderlyingType()->isRecordType()) |
| return true; |
| if (TD->getUnderlyingType()->isEnumeralType()) { |
| if (Context.getLangOpts().CPlusPlus11) |
| return true; |
| if (IsExtension) |
| *IsExtension = true; |
| } |
| } else if (isa<RecordDecl>(SD)) { |
| return true; |
| } else if (isa<EnumDecl>(SD)) { |
| if (Context.getLangOpts().CPlusPlus11) |
| return true; |
| if (IsExtension) |
| *IsExtension = true; |
| } |
| |
| return false; |
| } |
| |
| /// 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 nullptr; |
| |
| while (NNS->getPrefix()) |
| NNS = NNS->getPrefix(); |
| |
| if (NNS->getKind() != NestedNameSpecifier::Identifier) |
| return nullptr; |
| |
| LookupResult Found(*this, NNS->getAsIdentifier(), SourceLocation(), |
| LookupNestedNameSpecifierName); |
| LookupName(Found, S); |
| assert(!Found.isAmbiguous() && "Cannot handle ambiguities here yet"); |
| |
| if (!Found.isSingleResult()) |
| return nullptr; |
| |
| NamedDecl *Result = Found.getFoundDecl(); |
| if (isAcceptableNestedNameSpecifier(Result)) |
| return Result; |
| |
| return nullptr; |
| } |
| |
| bool Sema::isNonTypeNestedNameSpecifier(Scope *S, CXXScopeSpec &SS, |
| NestedNameSpecInfo &IdInfo) { |
| QualType ObjectType = GetTypeFromParser(IdInfo.ObjectType); |
| LookupResult Found(*this, IdInfo.Identifier, IdInfo.IdentifierLoc, |
| LookupNestedNameSpecifierName); |
| |
| // Determine where to perform name lookup |
| DeclContext *LookupCtx = nullptr; |
| 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(); |
| |
| return Found.getAsSingle<NamespaceDecl>(); |
| } |
| |
| namespace { |
| |
| // Callback to only accept typo corrections that can be a valid C++ member |
| // initializer: either a non-static field member or a base class. |
| class NestedNameSpecifierValidatorCCC final |
| : public CorrectionCandidateCallback { |
| public: |
| explicit NestedNameSpecifierValidatorCCC(Sema &SRef) |
| : SRef(SRef) {} |
| |
| bool ValidateCandidate(const TypoCorrection &candidate) override { |
| return SRef.isAcceptableNestedNameSpecifier(candidate.getCorrectionDecl()); |
| } |
| |
| std::unique_ptr<CorrectionCandidateCallback> clone() override { |
| return std::make_unique<NestedNameSpecifierValidatorCCC>(*this); |
| } |
| |
| private: |
| Sema &SRef; |
| }; |
| |
| } |
| |
| /// Build a new nested-name-specifier for "identifier::", as described |
| /// by ActOnCXXNestedNameSpecifier. |
| /// |
| /// \param S Scope in which the nested-name-specifier occurs. |
| /// \param IdInfo Parser information about an identifier in the |
| /// nested-name-spec. |
| /// \param EnteringContext If true, enter the context specified by the |
| /// nested-name-specifier. |
| /// \param SS Optional nested name specifier preceding the identifier. |
| /// \param ScopeLookupResult Provides the result of name lookup within the |
| /// scope of the nested-name-specifier that was computed at template |
| /// definition time. |
| /// \param ErrorRecoveryLookup Specifies if the method is called to improve |
| /// error recovery and what kind of recovery is performed. |
| /// \param IsCorrectedToColon If not null, suggestion of replace '::' -> ':' |
| /// are allowed. The bool value pointed by this parameter is set to |
| /// 'true' if the identifier is treated as if it was followed by ':', |
| /// not '::'. |
| /// \param OnlyNamespace If true, only considers namespaces in lookup. |
| /// |
| /// 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, NestedNameSpecInfo &IdInfo, |
| bool EnteringContext, CXXScopeSpec &SS, |
| NamedDecl *ScopeLookupResult, |
| bool ErrorRecoveryLookup, |
| bool *IsCorrectedToColon, |
| bool OnlyNamespace) { |
| if (IdInfo.Identifier->isEditorPlaceholder()) |
| return true; |
| LookupResult Found(*this, IdInfo.Identifier, IdInfo.IdentifierLoc, |
| OnlyNamespace ? LookupNamespaceName |
| : LookupNestedNameSpecifierName); |
| QualType ObjectType = GetTypeFromParser(IdInfo.ObjectType); |
| |
| // Determine where to perform name lookup |
| DeclContext *LookupCtx = nullptr; |
| bool isDependent = false; |
| if (IsCorrectedToColon) |
| *IsCorrectedToColon = 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 (Found.isAmbiguous()) |
| return true; |
| |
| // 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, IdInfo.Identifier, IdInfo.IdentifierLoc, IdInfo.CCLoc); |
| return false; |
| } |
| |
| if (Found.empty() && !ErrorRecoveryLookup) { |
| // If identifier is not found as class-name-or-namespace-name, but is found |
| // as other entity, don't look for typos. |
| LookupResult R(*this, Found.getLookupNameInfo(), LookupOrdinaryName); |
| if (LookupCtx) |
| LookupQualifiedName(R, LookupCtx); |
| else if (S && !isDependent) |
| LookupName(R, S); |
| if (!R.empty()) { |
| // Don't diagnose problems with this speculative lookup. |
| R.suppressDiagnostics(); |
| // The identifier is found in ordinary lookup. If correction to colon is |
| // allowed, suggest replacement to ':'. |
| if (IsCorrectedToColon) { |
| *IsCorrectedToColon = true; |
| Diag(IdInfo.CCLoc, diag::err_nested_name_spec_is_not_class) |
| << IdInfo.Identifier << getLangOpts().CPlusPlus |
| << FixItHint::CreateReplacement(IdInfo.CCLoc, ":"); |
| if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) |
| Diag(ND->getLocation(), diag::note_declared_at); |
| return true; |
| } |
| // Replacement '::' -> ':' is not allowed, just issue respective error. |
| Diag(R.getNameLoc(), OnlyNamespace |
| ? unsigned(diag::err_expected_namespace_name) |
| : unsigned(diag::err_expected_class_or_namespace)) |
| << IdInfo.Identifier << getLangOpts().CPlusPlus; |
| if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) |
| Diag(ND->getLocation(), diag::note_entity_declared_at) |
| << IdInfo.Identifier; |
| return true; |
| } |
| } |
| |
| if (Found.empty() && !ErrorRecoveryLookup && !getLangOpts().MSVCCompat) { |
| // We haven't found anything, and we're not recovering from a |
| // different kind of error, so look for typos. |
| DeclarationName Name = Found.getLookupName(); |
| Found.clear(); |
| NestedNameSpecifierValidatorCCC CCC(*this); |
| if (TypoCorrection Corrected = CorrectTypo( |
| Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, CCC, |
| CTK_ErrorRecovery, LookupCtx, EnteringContext)) { |
| if (LookupCtx) { |
| bool DroppedSpecifier = |
| Corrected.WillReplaceSpecifier() && |
| Name.getAsString() == Corrected.getAsString(getLangOpts()); |
| if (DroppedSpecifier) |
| SS.clear(); |
| diagnoseTypo(Corrected, PDiag(diag::err_no_member_suggest) |
| << Name << LookupCtx << DroppedSpecifier |
| << SS.getRange()); |
| } else |
| diagnoseTypo(Corrected, PDiag(diag::err_undeclared_var_use_suggest) |
| << Name); |
| |
| if (Corrected.getCorrectionSpecifier()) |
| SS.MakeTrivial(Context, Corrected.getCorrectionSpecifier(), |
| SourceRange(Found.getNameLoc())); |
| |
| if (NamedDecl *ND = Corrected.getFoundDecl()) |
| Found.addDecl(ND); |
| Found.setLookupName(Corrected.getCorrection()); |
| } else { |
| Found.setLookupName(IdInfo.Identifier); |
| } |
| } |
| |
| NamedDecl *SD = |
| Found.isSingleResult() ? Found.getRepresentativeDecl() : nullptr; |
| bool IsExtension = false; |
| bool AcceptSpec = isAcceptableNestedNameSpecifier(SD, &IsExtension); |
| if (!AcceptSpec && IsExtension) { |
| AcceptSpec = true; |
| Diag(IdInfo.IdentifierLoc, diag::ext_nested_name_spec_is_enum); |
| } |
| if (AcceptSpec) { |
| 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, IdInfo.Identifier, IdInfo.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(IdInfo.IdentifierLoc, |
| diag::err_nested_name_member_ref_lookup_ambiguous) |
| << IdInfo.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 (auto *TD = dyn_cast_or_null<TypedefNameDecl>(SD)) |
| MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false); |
| |
| // 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; |
| |
| // The use of a nested name specifier may trigger deprecation warnings. |
| DiagnoseUseOfDecl(SD, IdInfo.CCLoc); |
| |
| if (NamespaceDecl *Namespace = dyn_cast<NamespaceDecl>(SD)) { |
| SS.Extend(Context, Namespace, IdInfo.IdentifierLoc, IdInfo.CCLoc); |
| return false; |
| } |
| |
| if (NamespaceAliasDecl *Alias = dyn_cast<NamespaceAliasDecl>(SD)) { |
| SS.Extend(Context, Alias, IdInfo.IdentifierLoc, IdInfo.CCLoc); |
| return false; |
| } |
| |
| QualType T = |
| Context.getTypeDeclType(cast<TypeDecl>(SD->getUnderlyingDecl())); |
| TypeLocBuilder TLB; |
| if (isa<InjectedClassNameType>(T)) { |
| InjectedClassNameTypeLoc InjectedTL |
| = TLB.push<InjectedClassNameTypeLoc>(T); |
| InjectedTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<RecordType>(T)) { |
| RecordTypeLoc RecordTL = TLB.push<RecordTypeLoc>(T); |
| RecordTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<TypedefType>(T)) { |
| TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(T); |
| TypedefTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<EnumType>(T)) { |
| EnumTypeLoc EnumTL = TLB.push<EnumTypeLoc>(T); |
| EnumTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<TemplateTypeParmType>(T)) { |
| TemplateTypeParmTypeLoc TemplateTypeTL |
| = TLB.push<TemplateTypeParmTypeLoc>(T); |
| TemplateTypeTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<UnresolvedUsingType>(T)) { |
| UnresolvedUsingTypeLoc UnresolvedTL |
| = TLB.push<UnresolvedUsingTypeLoc>(T); |
| UnresolvedTL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<SubstTemplateTypeParmType>(T)) { |
| SubstTemplateTypeParmTypeLoc TL |
| = TLB.push<SubstTemplateTypeParmTypeLoc>(T); |
| TL.setNameLoc(IdInfo.IdentifierLoc); |
| } else if (isa<SubstTemplateTypeParmPackType>(T)) { |
| SubstTemplateTypeParmPackTypeLoc TL |
| = TLB.push<SubstTemplateTypeParmPackTypeLoc>(T); |
| TL.setNameLoc(IdInfo.IdentifierLoc); |
| } else { |
| llvm_unreachable("Unhandled TypeDecl node in nested-name-specifier"); |
| } |
| |
| if (T->isEnumeralType()) |
| Diag(IdInfo.IdentifierLoc, diag::warn_cxx98_compat_enum_nested_name_spec); |
| |
| SS.Extend(Context, SourceLocation(), TLB.getTypeLocInContext(Context, T), |
| IdInfo.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().MSVCCompat) { |
| DeclContext *DC = LookupCtx ? LookupCtx : CurContext; |
| if (DC->isDependentContext() && DC->isFunctionOrMethod()) { |
| CXXRecordDecl *ContainingClass = dyn_cast<CXXRecordDecl>(DC->getParent()); |
| if (ContainingClass && ContainingClass->hasAnyDependentBases()) { |
| Diag(IdInfo.IdentifierLoc, |
| diag::ext_undeclared_unqual_id_with_dependent_base) |
| << IdInfo.Identifier << ContainingClass; |
| SS.Extend(Context, IdInfo.Identifier, IdInfo.IdentifierLoc, |
| IdInfo.CCLoc); |
| return false; |
| } |
| } |
| } |
| |
| if (!Found.empty()) { |
| if (TypeDecl *TD = Found.getAsSingle<TypeDecl>()) |
| Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace) |
| << Context.getTypeDeclType(TD) << getLangOpts().CPlusPlus; |
| else { |
| Diag(IdInfo.IdentifierLoc, diag::err_expected_class_or_namespace) |
| << IdInfo.Identifier << getLangOpts().CPlusPlus; |
| if (NamedDecl *ND = Found.getAsSingle<NamedDecl>()) |
| Diag(ND->getLocation(), diag::note_entity_declared_at) |
| << IdInfo.Identifier; |
| } |
| } else if (SS.isSet()) |
| Diag(IdInfo.IdentifierLoc, diag::err_no_member) << IdInfo.Identifier |
| << LookupCtx << SS.getRange(); |
| else |
| Diag(IdInfo.IdentifierLoc, diag::err_undeclared_var_use) |
| << IdInfo.Identifier; |
| |
| return true; |
| } |
| |
| bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, NestedNameSpecInfo &IdInfo, |
| bool EnteringContext, CXXScopeSpec &SS, |
| bool ErrorRecoveryLookup, |
| bool *IsCorrectedToColon, |
| bool OnlyNamespace) { |
| if (SS.isInvalid()) |
| return true; |
| |
| return BuildCXXNestedNameSpecifier(S, IdInfo, EnteringContext, SS, |
| /*ScopeLookupResult=*/nullptr, false, |
| IsCorrectedToColon, OnlyNamespace); |
| } |
| |
| 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()); |
| if (T.isNull()) |
| return true; |
| |
| if (!T->isDependentType() && !T->getAs<TagType>()) { |
| Diag(DS.getTypeSpecTypeLoc(), diag::err_expected_class_or_namespace) |
| << 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, |
| NestedNameSpecInfo &IdInfo, |
| bool EnteringContext) { |
| if (SS.isInvalid()) |
| return false; |
| |
| return !BuildCXXNestedNameSpecifier(S, IdInfo, EnteringContext, SS, |
| /*ScopeLookupResult=*/nullptr, true); |
| } |
| |
| bool Sema::ActOnCXXNestedNameSpecifier(Scope *S, |
| CXXScopeSpec &SS, |
| SourceLocation TemplateKWLoc, |
| TemplateTy OpaqueTemplate, |
| SourceLocation TemplateNameLoc, |
| SourceLocation LAngleLoc, |
| ASTTemplateArgsPtr TemplateArgsIn, |
| SourceLocation RAngleLoc, |
| SourceLocation CCLoc, |
| bool EnteringContext) { |
| if (SS.isInvalid()) |
| return true; |
| |
| TemplateName Template = OpaqueTemplate.get(); |
| |
| // Translate the parser's template argument list in our AST format. |
| TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); |
| translateTemplateArguments(TemplateArgsIn, TemplateArgs); |
| |
| DependentTemplateName *DTN = Template.getAsDependentTemplateName(); |
| if (DTN && DTN->isIdentifier()) { |
| // Handle a dependent template specialization for which we cannot resolve |
| // the template name. |
| assert(DTN->getQualifier() == 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 we assumed an undeclared identifier was a template name, try to |
| // typo-correct it now. |
| if (Template.getAsAssumedTemplateName() && |
| resolveAssumedTemplateNameAsType(S, Template, TemplateNameLoc)) |
| return true; |
| |
| TemplateDecl *TD = Template.getAsTemplateDecl(); |
| if (Template.getAsOverloadedTemplate() || DTN || |
| isa<FunctionTemplateDecl>(TD) || isa<VarTemplateDecl>(TD)) { |
| SourceRange R(TemplateNameLoc, RAngleLoc); |
| if (SS.getRange().isValid()) |
| R.setBegin(SS.getRange().getBegin()); |
| |
| Diag(CCLoc, diag::err_non_type_template_in_nested_name_specifier) |
| << (TD && isa<VarTemplateDecl>(TD)) << Template << R; |
| NoteAllFoundTemplates(Template); |
| return true; |
| } |
| |
| // We were able to resolve the template name to an actual template. |
| // Build an appropriate nested-name-specifier. |
| QualType T = CheckTemplateIdType(Template, 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); |
| 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 { |
| /// 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 nullptr; |
| |
| void *Mem = Context.Allocate( |
| (sizeof(NestedNameSpecifierAnnotation) + SS.location_size()), |
| 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."); |
| |
| // Don't enter a declarator context when the current context is an Objective-C |
| // declaration. |
| if (isa<ObjCContainerDecl>(CurContext) || isa<ObjCMethodDecl>(CurContext)) |
| return false; |
| |
| NestedNameSpecifier *Qualifier = 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: |
| case NestedNameSpecifier::Super: |
| // 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); |
| } |
