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5.1.0_r3
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external
clang
lib
Sema
SemaTemplate.cpp
//===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===/ // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. //===----------------------------------------------------------------------===/ // // This file implements semantic analysis for C++ templates. //===----------------------------------------------------------------------===/ #include "TreeTransform.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclFriend.h" #include "clang/AST/DeclTemplate.h" #include "clang/AST/Expr.h" #include "clang/AST/ExprCXX.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/TypeVisitor.h" #include "clang/Basic/LangOptions.h" #include "clang/Basic/PartialDiagnostic.h" #include "clang/Basic/TargetInfo.h" #include "clang/Sema/DeclSpec.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/ParsedTemplate.h" #include "clang/Sema/Scope.h" #include "clang/Sema/SemaInternal.h" #include "clang/Sema/Template.h" #include "clang/Sema/TemplateDeduction.h" #include "llvm/ADT/SmallBitVector.h" #include "llvm/ADT/SmallString.h" #include "llvm/ADT/StringExtras.h" using namespace clang; using namespace sema; // Exported for use by Parser. SourceRange clang::getTemplateParamsRange(TemplateParameterList const * const *Ps, unsigned N) { if (!N) return SourceRange(); return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc()); } /// \brief Determine whether the declaration found is acceptable as the name /// of a template and, if so, return that template declaration. Otherwise, /// returns NULL. static NamedDecl *isAcceptableTemplateName(ASTContext &Context, NamedDecl *Orig, bool AllowFunctionTemplates) { NamedDecl *D = Orig->getUnderlyingDecl(); if (isa
(D)) { if (!AllowFunctionTemplates && isa
(D)) return nullptr; return Orig; } if (CXXRecordDecl *Record = dyn_cast
(D)) { // C++ [temp.local]p1: // Like normal (non-template) classes, class templates have an // injected-class-name (Clause 9). The injected-class-name // can be used with or without a template-argument-list. When // it is used without a template-argument-list, it is // equivalent to the injected-class-name followed by the // template-parameters of the class template enclosed in // <>. When it is used with a template-argument-list, it // refers to the specified class template specialization, // which could be the current specialization or another // specialization. if (Record->isInjectedClassName()) { Record = cast
(Record->getDeclContext()); if (Record->getDescribedClassTemplate()) return Record->getDescribedClassTemplate(); if (ClassTemplateSpecializationDecl *Spec = dyn_cast
(Record)) return Spec->getSpecializedTemplate(); } return nullptr; } return nullptr; } void Sema::FilterAcceptableTemplateNames(LookupResult &R, bool AllowFunctionTemplates) { // The set of class templates we've already seen. llvm::SmallPtrSet
ClassTemplates; LookupResult::Filter filter = R.makeFilter(); while (filter.hasNext()) { NamedDecl *Orig = filter.next(); NamedDecl *Repl = isAcceptableTemplateName(Context, Orig, AllowFunctionTemplates); if (!Repl) filter.erase(); else if (Repl != Orig) { // C++ [temp.local]p3: // A lookup that finds an injected-class-name (10.2) can result in an // ambiguity in certain cases (for example, if it is found in more than // one base class). If all of the injected-class-names that are found // refer to specializations of the same class template, and if the name // is used as a template-name, the reference refers to the class // template itself and not a specialization thereof, and is not // ambiguous. if (ClassTemplateDecl *ClassTmpl = dyn_cast
(Repl)) if (!ClassTemplates.insert(ClassTmpl)) { filter.erase(); continue; } // FIXME: we promote access to public here as a workaround to // the fact that LookupResult doesn't let us remember that we // found this template through a particular injected class name, // which means we end up doing nasty things to the invariants. // Pretending that access is public is *much* safer. filter.replace(Repl, AS_public); } } filter.done(); } bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R, bool AllowFunctionTemplates) { for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) if (isAcceptableTemplateName(Context, *I, AllowFunctionTemplates)) return true; return false; } TemplateNameKind Sema::isTemplateName(Scope *S, CXXScopeSpec &SS, bool hasTemplateKeyword, UnqualifiedId &Name, ParsedType ObjectTypePtr, bool EnteringContext, TemplateTy &TemplateResult, bool &MemberOfUnknownSpecialization) { assert(getLangOpts().CPlusPlus && "No template names in C!"); DeclarationName TName; MemberOfUnknownSpecialization = false; switch (Name.getKind()) { case UnqualifiedId::IK_Identifier: TName = DeclarationName(Name.Identifier); break; case UnqualifiedId::IK_OperatorFunctionId: TName = Context.DeclarationNames.getCXXOperatorName( Name.OperatorFunctionId.Operator); break; case UnqualifiedId::IK_LiteralOperatorId: TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier); break; default: return TNK_Non_template; } QualType ObjectType = ObjectTypePtr.get(); LookupResult R(*this, TName, Name.getLocStart(), LookupOrdinaryName); LookupTemplateName(R, S, SS, ObjectType, EnteringContext, MemberOfUnknownSpecialization); if (R.empty()) return TNK_Non_template; if (R.isAmbiguous()) { // Suppress diagnostics; we'll redo this lookup later. R.suppressDiagnostics(); // FIXME: we might have ambiguous templates, in which case we // should at least parse them properly! return TNK_Non_template; } TemplateName Template; TemplateNameKind TemplateKind; unsigned ResultCount = R.end() - R.begin(); if (ResultCount > 1) { // We assume that we'll preserve the qualifier from a function // template name in other ways. Template = Context.getOverloadedTemplateName(R.begin(), R.end()); TemplateKind = TNK_Function_template; // We'll do this lookup again later. R.suppressDiagnostics(); } else { TemplateDecl *TD = cast
((*R.begin())->getUnderlyingDecl()); if (SS.isSet() && !SS.isInvalid()) { NestedNameSpecifier *Qualifier = SS.getScopeRep(); Template = Context.getQualifiedTemplateName(Qualifier, hasTemplateKeyword, TD); } else { Template = TemplateName(TD); } if (isa
(TD)) { TemplateKind = TNK_Function_template; // We'll do this lookup again later. R.suppressDiagnostics(); } else { assert(isa
(TD) || isa
(TD) || isa
(TD) || isa
(TD)); TemplateKind = isa
(TD) ? TNK_Var_template : TNK_Type_template; } } TemplateResult = TemplateTy::make(Template); return TemplateKind; } bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II, SourceLocation IILoc, Scope *S, const CXXScopeSpec *SS, TemplateTy &SuggestedTemplate, TemplateNameKind &SuggestedKind) { // We can't recover unless there's a dependent scope specifier preceding the // template name. // FIXME: Typo correction? if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) || computeDeclContext(*SS)) return false; // The code is missing a 'template' keyword prior to the dependent template // name. NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep(); Diag(IILoc, diag::err_template_kw_missing) << Qualifier << II.getName() << FixItHint::CreateInsertion(IILoc, "template "); SuggestedTemplate = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II)); SuggestedKind = TNK_Dependent_template_name; return true; } void Sema::LookupTemplateName(LookupResult &Found, Scope *S, CXXScopeSpec &SS, QualType ObjectType, bool EnteringContext, bool &MemberOfUnknownSpecialization) { // Determine where to perform name lookup MemberOfUnknownSpecialization = false; 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(); assert((isDependent || !ObjectType->isIncompleteType() || ObjectType->castAs
()->isBeingDefined()) && "Caller should have completed object type"); // Template names cannot appear inside an Objective-C class or object type. if (ObjectType->isObjCObjectOrInterfaceType()) { Found.clear(); return; } } 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, EnteringContext); isDependent = isDependentScopeSpecifier(SS); // The declaration context must be complete. if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx)) return; } bool ObjectTypeSearchedInScope = false; bool AllowFunctionTemplatesInLookup = true; 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. LookupQualifiedName(Found, LookupCtx); if (!ObjectType.isNull() && Found.empty()) { // C++ [basic.lookup.classref]p1: // In a class member access expression (5.2.5), if the . or -> token is // immediately followed by an identifier followed by a <, the // identifier must be looked up to determine whether the < is the // beginning of a template argument list (14.2) or a less-than operator. // The identifier is first looked up in the class of the object // expression. If the identifier is not found, it is then looked up in // the context of the entire postfix-expression and shall name a class // or function template. if (S) LookupName(Found, S); ObjectTypeSearchedInScope = true; AllowFunctionTemplatesInLookup = false; } } else if (isDependent && (!S || ObjectType.isNull())) { // We cannot look into a dependent object type or nested nme // specifier. MemberOfUnknownSpecialization = true; return; } else { // Perform unqualified name lookup in the current scope. LookupName(Found, S); if (!ObjectType.isNull()) AllowFunctionTemplatesInLookup = false; } if (Found.empty() && !isDependent) { // If we did not find any names, attempt to correct any typos. DeclarationName Name = Found.getLookupName(); Found.clear(); // Simple filter callback that, for keywords, only accepts the C++ *_cast CorrectionCandidateCallback FilterCCC; FilterCCC.WantTypeSpecifiers = false; FilterCCC.WantExpressionKeywords = false; FilterCCC.WantRemainingKeywords = false; FilterCCC.WantCXXNamedCasts = true; if (TypoCorrection Corrected = CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S, &SS, FilterCCC, CTK_ErrorRecovery, LookupCtx)) { Found.setLookupName(Corrected.getCorrection()); if (Corrected.getCorrectionDecl()) Found.addDecl(Corrected.getCorrectionDecl()); FilterAcceptableTemplateNames(Found); if (!Found.empty()) { if (LookupCtx) { std::string CorrectedStr(Corrected.getAsString(getLangOpts())); bool DroppedSpecifier = Corrected.WillReplaceSpecifier() && Name.getAsString() == CorrectedStr; diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest) << Name << LookupCtx << DroppedSpecifier << SS.getRange()); } else { diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name); } } } else { Found.setLookupName(Name); } } FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup); if (Found.empty()) { if (isDependent) MemberOfUnknownSpecialization = true; return; } if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope && !getLangOpts().CPlusPlus11) { // C++03 [basic.lookup.classref]p1: // [...] If the lookup in the class of the object expression finds a // template, the name is also looked up in the context of the entire // postfix-expression and [...] // // Note: C++11 does not perform this second lookup. LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(), LookupOrdinaryName); LookupName(FoundOuter, S); FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false); if (FoundOuter.empty()) { // - if the name is not found, the name found in the class of the // object expression is used, otherwise } else if (!FoundOuter.getAsSingle
() || FoundOuter.isAmbiguous()) { // - if the name is found in the context of the entire // postfix-expression and does not name a class template, the name // found in the class of the object expression is used, otherwise FoundOuter.clear(); } else if (!Found.isSuppressingDiagnostics()) { // - if the name found is a class template, it must refer to the same // entity as the one found in the class of the object expression, // otherwise the program is ill-formed. if (!Found.isSingleResult() || Found.getFoundDecl()->getCanonicalDecl() != FoundOuter.getFoundDecl()->getCanonicalDecl()) { Diag(Found.getNameLoc(), diag::ext_nested_name_member_ref_lookup_ambiguous) << Found.getLookupName() << ObjectType; Diag(Found.getRepresentativeDecl()->getLocation(), diag::note_ambig_member_ref_object_type) << ObjectType; Diag(FoundOuter.getFoundDecl()->getLocation(), diag::note_ambig_member_ref_scope); // Recover by taking the template that we found in the object // expression's type. } } } } /// ActOnDependentIdExpression - Handle a dependent id-expression that /// was just parsed. This is only possible with an explicit scope /// specifier naming a dependent type. ExprResult Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, const DeclarationNameInfo &NameInfo, bool isAddressOfOperand, const TemplateArgumentListInfo *TemplateArgs) { DeclContext *DC = getFunctionLevelDeclContext(); if (!isAddressOfOperand && isa
(DC) && cast
(DC)->isInstance()) { QualType ThisType = cast
(DC)->getThisType(Context); // Since the 'this' expression is synthesized, we don't need to // perform the double-lookup check. NamedDecl *FirstQualifierInScope = nullptr; return CXXDependentScopeMemberExpr::Create( Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true, /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc, FirstQualifierInScope, NameInfo, TemplateArgs); } return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs); } ExprResult Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, const DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *TemplateArgs) { return DependentScopeDeclRefExpr::Create( Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo, TemplateArgs); } /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining /// that the template parameter 'PrevDecl' is being shadowed by a new /// declaration at location Loc. Returns true to indicate that this is /// an error, and false otherwise. void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) { assert(PrevDecl->isTemplateParameter() && "Not a template parameter"); // Microsoft Visual C++ permits template parameters to be shadowed. if (getLangOpts().MicrosoftExt) return; // C++ [temp.local]p4: // A template-parameter shall not be redeclared within its // scope (including nested scopes). Diag(Loc, diag::err_template_param_shadow) << cast
(PrevDecl)->getDeclName(); Diag(PrevDecl->getLocation(), diag::note_template_param_here); return; } /// AdjustDeclIfTemplate - If the given decl happens to be a template, reset /// the parameter D to reference the templated declaration and return a pointer /// to the template declaration. Otherwise, do nothing to D and return null. TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) { if (TemplateDecl *Temp = dyn_cast_or_null
(D)) { D = Temp->getTemplatedDecl(); return Temp; } return nullptr; } ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion( SourceLocation EllipsisLoc) const { assert(Kind == Template && "Only template template arguments can be pack expansions here"); assert(getAsTemplate().get().containsUnexpandedParameterPack() && "Template template argument pack expansion without packs"); ParsedTemplateArgument Result(*this); Result.EllipsisLoc = EllipsisLoc; return Result; } static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef, const ParsedTemplateArgument &Arg) { switch (Arg.getKind()) { case ParsedTemplateArgument::Type: { TypeSourceInfo *DI; QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI); if (!DI) DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation()); return TemplateArgumentLoc(TemplateArgument(T), DI); } case ParsedTemplateArgument::NonType: { Expr *E = static_cast
(Arg.getAsExpr()); return TemplateArgumentLoc(TemplateArgument(E), E); } case ParsedTemplateArgument::Template: { TemplateName Template = Arg.getAsTemplate().get(); TemplateArgument TArg; if (Arg.getEllipsisLoc().isValid()) TArg = TemplateArgument(Template, Optional
()); else TArg = Template; return TemplateArgumentLoc(TArg, Arg.getScopeSpec().getWithLocInContext( SemaRef.Context), Arg.getLocation(), Arg.getEllipsisLoc()); } } llvm_unreachable("Unhandled parsed template argument"); } /// \brief Translates template arguments as provided by the parser /// into template arguments used by semantic analysis. void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn, TemplateArgumentListInfo &TemplateArgs) { for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I) TemplateArgs.addArgument(translateTemplateArgument(*this, TemplateArgsIn[I])); } static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S, SourceLocation Loc, IdentifierInfo *Name) { NamedDecl *PrevDecl = SemaRef.LookupSingleName( S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForRedeclaration); if (PrevDecl && PrevDecl->isTemplateParameter()) SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl); } /// ActOnTypeParameter - Called when a C++ template type parameter /// (e.g., "typename T") has been parsed. Typename specifies whether /// the keyword "typename" was used to declare the type parameter /// (otherwise, "class" was used), and KeyLoc is the location of the /// "class" or "typename" keyword. ParamName is the name of the /// parameter (NULL indicates an unnamed template parameter) and /// ParamNameLoc is the location of the parameter name (if any). /// If the type parameter has a default argument, it will be added /// later via ActOnTypeParameterDefault. Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, SourceLocation EllipsisLoc, SourceLocation KeyLoc, IdentifierInfo *ParamName, SourceLocation ParamNameLoc, unsigned Depth, unsigned Position, SourceLocation EqualLoc, ParsedType DefaultArg) { assert(S->isTemplateParamScope() && "Template type parameter not in template parameter scope!"); bool Invalid = false; SourceLocation Loc = ParamNameLoc; if (!ParamName) Loc = KeyLoc; bool IsParameterPack = EllipsisLoc.isValid(); TemplateTypeParmDecl *Param = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(), KeyLoc, Loc, Depth, Position, ParamName, Typename, IsParameterPack); Param->setAccess(AS_public); if (Invalid) Param->setInvalidDecl(); if (ParamName) { maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName); // Add the template parameter into the current scope. S->AddDecl(Param); IdResolver.AddDecl(Param); } // C++0x [temp.param]p9: // A default template-argument may be specified for any kind of // template-parameter that is not a template parameter pack. if (DefaultArg && IsParameterPack) { Diag(EqualLoc, diag::err_template_param_pack_default_arg); DefaultArg = ParsedType(); } // Handle the default argument, if provided. if (DefaultArg) { TypeSourceInfo *DefaultTInfo; GetTypeFromParser(DefaultArg, &DefaultTInfo); assert(DefaultTInfo && "expected source information for type"); // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo, UPPC_DefaultArgument)) return Param; // Check the template argument itself. if (CheckTemplateArgument(Param, DefaultTInfo)) { Param->setInvalidDecl(); return Param; } Param->setDefaultArgument(DefaultTInfo, false); } return Param; } /// \brief Check that the type of a non-type template parameter is /// well-formed. /// /// \returns the (possibly-promoted) parameter type if valid; /// otherwise, produces a diagnostic and returns a NULL type. QualType Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) { // We don't allow variably-modified types as the type of non-type template // parameters. if (T->isVariablyModifiedType()) { Diag(Loc, diag::err_variably_modified_nontype_template_param) << T; return QualType(); } // C++ [temp.param]p4: // // A non-type template-parameter shall have one of the following // (optionally cv-qualified) types: // // -- integral or enumeration type, if (T->isIntegralOrEnumerationType() || // -- pointer to object or pointer to function, T->isPointerType() || // -- reference to object or reference to function, T->isReferenceType() || // -- pointer to member, T->isMemberPointerType() || // -- std::nullptr_t. T->isNullPtrType() || // If T is a dependent type, we can't do the check now, so we // assume that it is well-formed. T->isDependentType()) { // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter // are ignored when determining its type. return T.getUnqualifiedType(); } // C++ [temp.param]p8: // // A non-type template-parameter of type "array of T" or // "function returning T" is adjusted to be of type "pointer to // T" or "pointer to function returning T", respectively. else if (T->isArrayType()) // FIXME: Keep the type prior to promotion? return Context.getArrayDecayedType(T); else if (T->isFunctionType()) // FIXME: Keep the type prior to promotion? return Context.getPointerType(T); Diag(Loc, diag::err_template_nontype_parm_bad_type) << T; return QualType(); } Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D, unsigned Depth, unsigned Position, SourceLocation EqualLoc, Expr *Default) { TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S); QualType T = TInfo->getType(); assert(S->isTemplateParamScope() && "Non-type template parameter not in template parameter scope!"); bool Invalid = false; T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc()); if (T.isNull()) { T = Context.IntTy; // Recover with an 'int' type. Invalid = true; } IdentifierInfo *ParamName = D.getIdentifier(); bool IsParameterPack = D.hasEllipsis(); NonTypeTemplateParmDecl *Param = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), D.getLocStart(), D.getIdentifierLoc(), Depth, Position, ParamName, T, IsParameterPack, TInfo); Param->setAccess(AS_public); if (Invalid) Param->setInvalidDecl(); if (ParamName) { maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(), ParamName); // Add the template parameter into the current scope. S->AddDecl(Param); IdResolver.AddDecl(Param); } // C++0x [temp.param]p9: // A default template-argument may be specified for any kind of // template-parameter that is not a template parameter pack. if (Default && IsParameterPack) { Diag(EqualLoc, diag::err_template_param_pack_default_arg); Default = nullptr; } // Check the well-formedness of the default template argument, if provided. if (Default) { // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument)) return Param; TemplateArgument Converted; ExprResult DefaultRes = CheckTemplateArgument(Param, Param->getType(), Default, Converted); if (DefaultRes.isInvalid()) { Param->setInvalidDecl(); return Param; } Default = DefaultRes.get(); Param->setDefaultArgument(Default, false); } return Param; } /// ActOnTemplateTemplateParameter - Called when a C++ template template /// parameter (e.g. T in template
class T> class array) /// has been parsed. S is the current scope. Decl *Sema::ActOnTemplateTemplateParameter(Scope* S, SourceLocation TmpLoc, TemplateParameterList *Params, SourceLocation EllipsisLoc, IdentifierInfo *Name, SourceLocation NameLoc, unsigned Depth, unsigned Position, SourceLocation EqualLoc, ParsedTemplateArgument Default) { assert(S->isTemplateParamScope() && "Template template parameter not in template parameter scope!"); // Construct the parameter object. bool IsParameterPack = EllipsisLoc.isValid(); TemplateTemplateParmDecl *Param = TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(), NameLoc.isInvalid()? TmpLoc : NameLoc, Depth, Position, IsParameterPack, Name, Params); Param->setAccess(AS_public); // If the template template parameter has a name, then link the identifier // into the scope and lookup mechanisms. if (Name) { maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name); S->AddDecl(Param); IdResolver.AddDecl(Param); } if (Params->size() == 0) { Diag(Param->getLocation(), diag::err_template_template_parm_no_parms) << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc()); Param->setInvalidDecl(); } // C++0x [temp.param]p9: // A default template-argument may be specified for any kind of // template-parameter that is not a template parameter pack. if (IsParameterPack && !Default.isInvalid()) { Diag(EqualLoc, diag::err_template_param_pack_default_arg); Default = ParsedTemplateArgument(); } if (!Default.isInvalid()) { // Check only that we have a template template argument. We don't want to // try to check well-formedness now, because our template template parameter // might have dependent types in its template parameters, which we wouldn't // be able to match now. // // If none of the template template parameter's template arguments mention // other template parameters, we could actually perform more checking here. // However, it isn't worth doing. TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default); if (DefaultArg.getArgument().getAsTemplate().isNull()) { Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template) << DefaultArg.getSourceRange(); return Param; } // Check for unexpanded parameter packs. if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(), DefaultArg.getArgument().getAsTemplate(), UPPC_DefaultArgument)) return Param; Param->setDefaultArgument(DefaultArg, false); } return Param; } /// ActOnTemplateParameterList - Builds a TemplateParameterList that /// contains the template parameters in Params/NumParams. TemplateParameterList * Sema::ActOnTemplateParameterList(unsigned Depth, SourceLocation ExportLoc, SourceLocation TemplateLoc, SourceLocation LAngleLoc, Decl **Params, unsigned NumParams, SourceLocation RAngleLoc) { if (ExportLoc.isValid()) Diag(ExportLoc, diag::warn_template_export_unsupported); return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc, (NamedDecl**)Params, NumParams, RAngleLoc); } static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) { if (SS.isSet()) T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext())); } DeclResult Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc, CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc, AttributeList *Attr, TemplateParameterList *TemplateParams, AccessSpecifier AS, SourceLocation ModulePrivateLoc, unsigned NumOuterTemplateParamLists, TemplateParameterList** OuterTemplateParamLists) { assert(TemplateParams && TemplateParams->size() > 0 && "No template parameters"); assert(TUK != TUK_Reference && "Can only declare or define class templates"); bool Invalid = false; // Check that we can declare a template here. if (CheckTemplateDeclScope(S, TemplateParams)) return true; TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); assert(Kind != TTK_Enum && "can't build template of enumerated type"); // There is no such thing as an unnamed class template. if (!Name) { Diag(KWLoc, diag::err_template_unnamed_class); return true; } // Find any previous declaration with this name. For a friend with no // scope explicitly specified, we only look for tag declarations (per // C++11 [basic.lookup.elab]p2). DeclContext *SemanticContext; LookupResult Previous(*this, Name, NameLoc, (SS.isEmpty() && TUK == TUK_Friend) ? LookupTagName : LookupOrdinaryName, ForRedeclaration); if (SS.isNotEmpty() && !SS.isInvalid()) { SemanticContext = computeDeclContext(SS, true); if (!SemanticContext) { // FIXME: Horrible, horrible hack! We can't currently represent this // in the AST, and historically we have just ignored such friend // class templates, so don't complain here. Diag(NameLoc, TUK == TUK_Friend ? diag::warn_template_qualified_friend_ignored : diag::err_template_qualified_declarator_no_match) << SS.getScopeRep() << SS.getRange(); return TUK != TUK_Friend; } if (RequireCompleteDeclContext(SS, SemanticContext)) return true; // If we're adding a template to a dependent context, we may need to // rebuilding some of the types used within the template parameter list, // now that we know what the current instantiation is. if (SemanticContext->isDependentContext()) { ContextRAII SavedContext(*this, SemanticContext); if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams)) Invalid = true; } else if (TUK != TUK_Friend && TUK != TUK_Reference) diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc); LookupQualifiedName(Previous, SemanticContext); } else { SemanticContext = CurContext; LookupName(Previous, S); } if (Previous.isAmbiguous()) return true; NamedDecl *PrevDecl = nullptr; if (Previous.begin() != Previous.end()) PrevDecl = (*Previous.begin())->getUnderlyingDecl(); // If there is a previous declaration with the same name, check // whether this is a valid redeclaration. ClassTemplateDecl *PrevClassTemplate = dyn_cast_or_null
(PrevDecl); // We may have found the injected-class-name of a class template, // class template partial specialization, or class template specialization. // In these cases, grab the template that is being defined or specialized. if (!PrevClassTemplate && PrevDecl && isa
(PrevDecl) && cast
(PrevDecl)->isInjectedClassName()) { PrevDecl = cast
(PrevDecl->getDeclContext()); PrevClassTemplate = cast
(PrevDecl)->getDescribedClassTemplate(); if (!PrevClassTemplate && isa
(PrevDecl)) { PrevClassTemplate = cast
(PrevDecl) ->getSpecializedTemplate(); } } if (TUK == TUK_Friend) { // C++ [namespace.memdef]p3: // [...] When looking for a prior declaration of a class or a function // declared as a friend, and when the name of the friend class or // function is neither a qualified name nor a template-id, scopes outside // the innermost enclosing namespace scope are not considered. if (!SS.isSet()) { DeclContext *OutermostContext = CurContext; while (!OutermostContext->isFileContext()) OutermostContext = OutermostContext->getLookupParent(); if (PrevDecl && (OutermostContext->Equals(PrevDecl->getDeclContext()) || OutermostContext->Encloses(PrevDecl->getDeclContext()))) { SemanticContext = PrevDecl->getDeclContext(); } else { // Declarations in outer scopes don't matter. However, the outermost // context we computed is the semantic context for our new // declaration. PrevDecl = PrevClassTemplate = nullptr; SemanticContext = OutermostContext; // Check that the chosen semantic context doesn't already contain a // declaration of this name as a non-tag type. LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName, ForRedeclaration); DeclContext *LookupContext = SemanticContext; while (LookupContext->isTransparentContext()) LookupContext = LookupContext->getLookupParent(); LookupQualifiedName(Previous, LookupContext); if (Previous.isAmbiguous()) return true; if (Previous.begin() != Previous.end()) PrevDecl = (*Previous.begin())->getUnderlyingDecl(); } } } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S, SS.isValid())) PrevDecl = PrevClassTemplate = nullptr; if (PrevClassTemplate) { // Ensure that the template parameter lists are compatible. Skip this check // for a friend in a dependent context: the template parameter list itself // could be dependent. if (!(TUK == TUK_Friend && CurContext->isDependentContext()) && !TemplateParameterListsAreEqual(TemplateParams, PrevClassTemplate->getTemplateParameters(), /*Complain=*/true, TPL_TemplateMatch)) return true; // C++ [temp.class]p4: // In a redeclaration, partial specialization, explicit // specialization or explicit instantiation of a class template, // the class-key shall agree in kind with the original class // template declaration (7.1.5.3). RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl(); if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind, TUK == TUK_Definition, KWLoc, *Name)) { Diag(KWLoc, diag::err_use_with_wrong_tag) << Name << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName()); Diag(PrevRecordDecl->getLocation(), diag::note_previous_use); Kind = PrevRecordDecl->getTagKind(); } // Check for redefinition of this class template. if (TUK == TUK_Definition) { if (TagDecl *Def = PrevRecordDecl->getDefinition()) { Diag(NameLoc, diag::err_redefinition) << Name; Diag(Def->getLocation(), diag::note_previous_definition); // FIXME: Would it make sense to try to "forget" the previous // definition, as part of error recovery? return true; } } } else if (PrevDecl && PrevDecl->isTemplateParameter()) { // Maybe we will complain about the shadowed template parameter. DiagnoseTemplateParameterShadow(NameLoc, PrevDecl); // Just pretend that we didn't see the previous declaration. PrevDecl = nullptr; } else if (PrevDecl) { // C++ [temp]p5: // A class template shall not have the same name as any other // template, class, function, object, enumeration, enumerator, // namespace, or type in the same scope (3.3), except as specified // in (14.5.4). Diag(NameLoc, diag::err_redefinition_different_kind) << Name; Diag(PrevDecl->getLocation(), diag::note_previous_definition); return true; } // Check the template parameter list of this declaration, possibly // merging in the template parameter list from the previous class // template declaration. Skip this check for a friend in a dependent // context, because the template parameter list might be dependent. if (!(TUK == TUK_Friend && CurContext->isDependentContext()) && CheckTemplateParameterList( TemplateParams, PrevClassTemplate ? PrevClassTemplate->getTemplateParameters() : nullptr, (SS.isSet() && SemanticContext && SemanticContext->isRecord() && SemanticContext->isDependentContext()) ? TPC_ClassTemplateMember : TUK == TUK_Friend ? TPC_FriendClassTemplate : TPC_ClassTemplate)) Invalid = true; if (SS.isSet()) { // If the name of the template was qualified, we must be defining the // template out-of-line. if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) { Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match : diag::err_member_decl_does_not_match) << Name << SemanticContext << /*IsDefinition*/true << SS.getRange(); Invalid = true; } } CXXRecordDecl *NewClass = CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name, PrevClassTemplate? PrevClassTemplate->getTemplatedDecl() : nullptr, /*DelayTypeCreation=*/true); SetNestedNameSpecifier(NewClass, SS); if (NumOuterTemplateParamLists > 0) NewClass->setTemplateParameterListsInfo(Context, NumOuterTemplateParamLists, OuterTemplateParamLists); // Add alignment attributes if necessary; these attributes are checked when // the ASTContext lays out the structure. if (TUK == TUK_Definition) { AddAlignmentAttributesForRecord(NewClass); AddMsStructLayoutForRecord(NewClass); } ClassTemplateDecl *NewTemplate = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc, DeclarationName(Name), TemplateParams, NewClass, PrevClassTemplate); NewClass->setDescribedClassTemplate(NewTemplate); if (ModulePrivateLoc.isValid()) NewTemplate->setModulePrivate(); // Build the type for the class template declaration now. QualType T = NewTemplate->getInjectedClassNameSpecialization(); T = Context.getInjectedClassNameType(NewClass, T); assert(T->isDependentType() && "Class template type is not dependent?"); (void)T; // If we are providing an explicit specialization of a member that is a // class template, make a note of that. if (PrevClassTemplate && PrevClassTemplate->getInstantiatedFromMemberTemplate()) PrevClassTemplate->setMemberSpecialization(); // Set the access specifier. if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord()) SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS); // Set the lexical context of these templates NewClass->setLexicalDeclContext(CurContext); NewTemplate->setLexicalDeclContext(CurContext); if (TUK == TUK_Definition) NewClass->startDefinition(); if (Attr) ProcessDeclAttributeList(S, NewClass, Attr); if (PrevClassTemplate) mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl()); AddPushedVisibilityAttribute(NewClass); if (TUK != TUK_Friend) PushOnScopeChains(NewTemplate, S); else { if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) { NewTemplate->setAccess(PrevClassTemplate->getAccess()); NewClass->setAccess(PrevClassTemplate->getAccess()); } NewTemplate->setObjectOfFriendDecl(); // Friend templates are visible in fairly strange ways. if (!CurContext->isDependentContext()) { DeclContext *DC = SemanticContext->getRedeclContext(); DC->makeDeclVisibleInContext(NewTemplate); if (Scope *EnclosingScope = getScopeForDeclContext(S, DC)) PushOnScopeChains(NewTemplate, EnclosingScope, /* AddToContext = */ false); } FriendDecl *Friend = FriendDecl::Create(Context, CurContext, NewClass->getLocation(), NewTemplate, /*FIXME:*/NewClass->getLocation()); Friend->setAccess(AS_public); CurContext->addDecl(Friend); } if (Invalid) { NewTemplate->setInvalidDecl(); NewClass->setInvalidDecl(); } ActOnDocumentableDecl(NewTemplate); return NewTemplate; } /// \brief Diagnose the presence of a default template argument on a /// template parameter, which is ill-formed in certain contexts. /// /// \returns true if the default template argument should be dropped. static bool DiagnoseDefaultTemplateArgument(Sema &S, Sema::TemplateParamListContext TPC, SourceLocation ParamLoc, SourceRange DefArgRange) { switch (TPC) { case Sema::TPC_ClassTemplate: case Sema::TPC_VarTemplate: case Sema::TPC_TypeAliasTemplate: return false; case Sema::TPC_FunctionTemplate: case Sema::TPC_FriendFunctionTemplateDefinition: // C++ [temp.param]p9: // A default template-argument shall not be specified in a // function template declaration or a function template // definition [...] // If a friend function template declaration specifies a default // template-argument, that declaration shall be a definition and shall be // the only declaration of the function template in the translation unit. // (C++98/03 doesn't have this wording; see DR226). S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_parameter_default_in_function_template : diag::ext_template_parameter_default_in_function_template) << DefArgRange; return false; case Sema::TPC_ClassTemplateMember: // C++0x [temp.param]p9: // A default template-argument shall not be specified in the // template-parameter-lists of the definition of a member of a // class template that appears outside of the member's class. S.Diag(ParamLoc, diag::err_template_parameter_default_template_member) << DefArgRange; return true; case Sema::TPC_FriendClassTemplate: case Sema::TPC_FriendFunctionTemplate: // C++ [temp.param]p9: // A default template-argument shall not be specified in a // friend template declaration. S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template) << DefArgRange; return true; // FIXME: C++0x [temp.param]p9 allows default template-arguments // for friend function templates if there is only a single // declaration (and it is a definition). Strange! } llvm_unreachable("Invalid TemplateParamListContext!"); } /// \brief Check for unexpanded parameter packs within the template parameters /// of a template template parameter, recursively. static bool DiagnoseUnexpandedParameterPacks(Sema &S, TemplateTemplateParmDecl *TTP) { // A template template parameter which is a parameter pack is also a pack // expansion. if (TTP->isParameterPack()) return false; TemplateParameterList *Params = TTP->getTemplateParameters(); for (unsigned I = 0, N = Params->size(); I != N; ++I) { NamedDecl *P = Params->getParam(I); if (NonTypeTemplateParmDecl *NTTP = dyn_cast
(P)) { if (!NTTP->isParameterPack() && S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(), NTTP->getTypeSourceInfo(), Sema::UPPC_NonTypeTemplateParameterType)) return true; continue; } if (TemplateTemplateParmDecl *InnerTTP = dyn_cast
(P)) if (DiagnoseUnexpandedParameterPacks(S, InnerTTP)) return true; } return false; } /// \brief Checks the validity of a template parameter list, possibly /// considering the template parameter list from a previous /// declaration. /// /// If an "old" template parameter list is provided, it must be /// equivalent (per TemplateParameterListsAreEqual) to the "new" /// template parameter list. /// /// \param NewParams Template parameter list for a new template /// declaration. This template parameter list will be updated with any /// default arguments that are carried through from the previous /// template parameter list. /// /// \param OldParams If provided, template parameter list from a /// previous declaration of the same template. Default template /// arguments will be merged from the old template parameter list to /// the new template parameter list. /// /// \param TPC Describes the context in which we are checking the given /// template parameter list. /// /// \returns true if an error occurred, false otherwise. bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams, TemplateParameterList *OldParams, TemplateParamListContext TPC) { bool Invalid = false; // C++ [temp.param]p10: // The set of default template-arguments available for use with a // template declaration or definition is obtained by merging the // default arguments from the definition (if in scope) and all // declarations in scope in the same way default function // arguments are (8.3.6). bool SawDefaultArgument = false; SourceLocation PreviousDefaultArgLoc; // Dummy initialization to avoid warnings. TemplateParameterList::iterator OldParam = NewParams->end(); if (OldParams) OldParam = OldParams->begin(); bool RemoveDefaultArguments = false; for (TemplateParameterList::iterator NewParam = NewParams->begin(), NewParamEnd = NewParams->end(); NewParam != NewParamEnd; ++NewParam) { // Variables used to diagnose redundant default arguments bool RedundantDefaultArg = false; SourceLocation OldDefaultLoc; SourceLocation NewDefaultLoc; // Variable used to diagnose missing default arguments bool MissingDefaultArg = false; // Variable used to diagnose non-final parameter packs bool SawParameterPack = false; if (TemplateTypeParmDecl *NewTypeParm = dyn_cast
(*NewParam)) { // Check the presence of a default argument here. if (NewTypeParm->hasDefaultArgument() && DiagnoseDefaultTemplateArgument(*this, TPC, NewTypeParm->getLocation(), NewTypeParm->getDefaultArgumentInfo()->getTypeLoc() .getSourceRange())) NewTypeParm->removeDefaultArgument(); // Merge default arguments for template type parameters. TemplateTypeParmDecl *OldTypeParm = OldParams? cast
(*OldParam) : nullptr; if (NewTypeParm->isParameterPack()) { assert(!NewTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"); SawParameterPack = true; } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() && NewTypeParm->hasDefaultArgument()) { OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc(); NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc(); SawDefaultArgument = true; RedundantDefaultArg = true; PreviousDefaultArgLoc = NewDefaultLoc; } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) { // Merge the default argument from the old declaration to the // new declaration. NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(), true); PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc(); } else if (NewTypeParm->hasDefaultArgument()) { SawDefaultArgument = true; PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc(); } else if (SawDefaultArgument) MissingDefaultArg = true; } else if (NonTypeTemplateParmDecl *NewNonTypeParm = dyn_cast
(*NewParam)) { // Check for unexpanded parameter packs. if (!NewNonTypeParm->isParameterPack() && DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(), NewNonTypeParm->getTypeSourceInfo(), UPPC_NonTypeTemplateParameterType)) { Invalid = true; continue; } // Check the presence of a default argument here. if (NewNonTypeParm->hasDefaultArgument() && DiagnoseDefaultTemplateArgument(*this, TPC, NewNonTypeParm->getLocation(), NewNonTypeParm->getDefaultArgument()->getSourceRange())) { NewNonTypeParm->removeDefaultArgument(); } // Merge default arguments for non-type template parameters NonTypeTemplateParmDecl *OldNonTypeParm = OldParams? cast
(*OldParam) : nullptr; if (NewNonTypeParm->isParameterPack()) { assert(!NewNonTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"); if (!NewNonTypeParm->isPackExpansion()) SawParameterPack = true; } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() && NewNonTypeParm->hasDefaultArgument()) { OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc(); NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc(); SawDefaultArgument = true; RedundantDefaultArg = true; PreviousDefaultArgLoc = NewDefaultLoc; } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) { // Merge the default argument from the old declaration to the // new declaration. // FIXME: We need to create a new kind of "default argument" // expression that points to a previous non-type template // parameter. NewNonTypeParm->setDefaultArgument( OldNonTypeParm->getDefaultArgument(), /*Inherited=*/ true); PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc(); } else if (NewNonTypeParm->hasDefaultArgument()) { SawDefaultArgument = true; PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc(); } else if (SawDefaultArgument) MissingDefaultArg = true; } else { TemplateTemplateParmDecl *NewTemplateParm = cast
(*NewParam); // Check for unexpanded parameter packs, recursively. if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) { Invalid = true; continue; } // Check the presence of a default argument here. if (NewTemplateParm->hasDefaultArgument() && DiagnoseDefaultTemplateArgument(*this, TPC, NewTemplateParm->getLocation(), NewTemplateParm->getDefaultArgument().getSourceRange())) NewTemplateParm->removeDefaultArgument(); // Merge default arguments for template template parameters TemplateTemplateParmDecl *OldTemplateParm = OldParams? cast
(*OldParam) : nullptr; if (NewTemplateParm->isParameterPack()) { assert(!NewTemplateParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"); if (!NewTemplateParm->isPackExpansion()) SawParameterPack = true; } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() && NewTemplateParm->hasDefaultArgument()) { OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation(); NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation(); SawDefaultArgument = true; RedundantDefaultArg = true; PreviousDefaultArgLoc = NewDefaultLoc; } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) { // Merge the default argument from the old declaration to the // new declaration. // FIXME: We need to create a new kind of "default argument" expression // that points to a previous template template parameter. NewTemplateParm->setDefaultArgument( OldTemplateParm->getDefaultArgument(), /*Inherited=*/ true); PreviousDefaultArgLoc = OldTemplateParm->getDefaultArgument().getLocation(); } else if (NewTemplateParm->hasDefaultArgument()) { SawDefaultArgument = true; PreviousDefaultArgLoc = NewTemplateParm->getDefaultArgument().getLocation(); } else if (SawDefaultArgument) MissingDefaultArg = true; } // C++11 [temp.param]p11: // If a template parameter of a primary class template or alias template // is a template parameter pack, it shall be the last template parameter. if (SawParameterPack && (NewParam + 1) != NewParamEnd && (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate || TPC == TPC_TypeAliasTemplate)) { Diag((*NewParam)->getLocation(), diag::err_template_param_pack_must_be_last_template_parameter); Invalid = true; } if (RedundantDefaultArg) { // C++ [temp.param]p12: // A template-parameter shall not be given default arguments // by two different declarations in the same scope. Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition); Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg); Invalid = true; } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) { // C++ [temp.param]p11: // If a template-parameter of a class template has a default // template-argument, each subsequent template-parameter shall either // have a default template-argument supplied or be a template parameter // pack. Diag((*NewParam)->getLocation(), diag::err_template_param_default_arg_missing); Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg); Invalid = true; RemoveDefaultArguments = true; } // If we have an old template parameter list that we're merging // in, move on to the next parameter. if (OldParams) ++OldParam; } // We were missing some default arguments at the end of the list, so remove // all of the default arguments. if (RemoveDefaultArguments) { for (TemplateParameterList::iterator NewParam = NewParams->begin(), NewParamEnd = NewParams->end(); NewParam != NewParamEnd; ++NewParam) { if (TemplateTypeParmDecl *TTP = dyn_cast
(*NewParam)) TTP->removeDefaultArgument(); else if (NonTypeTemplateParmDecl *NTTP = dyn_cast
(*NewParam)) NTTP->removeDefaultArgument(); else cast
(*NewParam)->removeDefaultArgument(); } } return Invalid; } namespace { /// A class which looks for a use of a certain level of template /// parameter. struct DependencyChecker : RecursiveASTVisitor
{ typedef RecursiveASTVisitor
super; unsigned Depth; bool Match; SourceLocation MatchLoc; DependencyChecker(unsigned Depth) : Depth(Depth), Match(false) {} DependencyChecker(TemplateParameterList *Params) : Match(false) { NamedDecl *ND = Params->getParam(0); if (TemplateTypeParmDecl *PD = dyn_cast
(ND)) { Depth = PD->getDepth(); } else if (NonTypeTemplateParmDecl *PD = dyn_cast
(ND)) { Depth = PD->getDepth(); } else { Depth = cast
(ND)->getDepth(); } } bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) { if (ParmDepth >= Depth) { Match = true; MatchLoc = Loc; return true; } return false; } bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) { return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc()); } bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) { return !Matches(T->getDepth()); } bool TraverseTemplateName(TemplateName N) { if (TemplateTemplateParmDecl *PD = dyn_cast_or_null
(N.getAsTemplateDecl())) if (Matches(PD->getDepth())) return false; return super::TraverseTemplateName(N); } bool VisitDeclRefExpr(DeclRefExpr *E) { if (NonTypeTemplateParmDecl *PD = dyn_cast
(E->getDecl())) if (Matches(PD->getDepth(), E->getExprLoc())) return false; return super::VisitDeclRefExpr(E); } bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) { return TraverseType(T->getReplacementType()); } bool VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) { return TraverseTemplateArgument(T->getArgumentPack()); } bool TraverseInjectedClassNameType(const InjectedClassNameType *T) { return TraverseType(T->getInjectedSpecializationType()); } }; } /// Determines whether a given type depends on the given parameter /// list. static bool DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) { DependencyChecker Checker(Params); Checker.TraverseType(T); return Checker.Match; } // Find the source range corresponding to the named type in the given // nested-name-specifier, if any. static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context, QualType T, const CXXScopeSpec &SS) { NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data()); while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) { if (const Type *CurType = NNS->getAsType()) { if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0))) return NNSLoc.getTypeLoc().getSourceRange(); } else break; NNSLoc = NNSLoc.getPrefix(); } return SourceRange(); } /// \brief Match the given template parameter lists to the given scope /// specifier, returning the template parameter list that applies to the /// name. /// /// \param DeclStartLoc the start of the declaration that has a scope /// specifier or a template parameter list. /// /// \param DeclLoc The location of the declaration itself. /// /// \param SS the scope specifier that will be matched to the given template /// parameter lists. This scope specifier precedes a qualified name that is /// being declared. /// /// \param TemplateId The template-id following the scope specifier, if there /// is one. Used to check for a missing 'template<>'. /// /// \param ParamLists the template parameter lists, from the outermost to the /// innermost template parameter lists. /// /// \param IsFriend Whether to apply the slightly different rules for /// matching template parameters to scope specifiers in friend /// declarations. /// /// \param IsExplicitSpecialization will be set true if the entity being /// declared is an explicit specialization, false otherwise. /// /// \returns the template parameter list, if any, that corresponds to the /// name that is preceded by the scope specifier @p SS. This template /// parameter list may have template parameters (if we're declaring a /// template) or may have no template parameters (if we're declaring a /// template specialization), or may be NULL (if what we're declaring isn't /// itself a template). TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier( SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS, TemplateIdAnnotation *TemplateId, ArrayRef
ParamLists, bool IsFriend, bool &IsExplicitSpecialization, bool &Invalid) { IsExplicitSpecialization = false; Invalid = false; // The sequence of nested types to which we will match up the template // parameter lists. We first build this list by starting with the type named // by the nested-name-specifier and walking out until we run out of types. SmallVector
NestedTypes; QualType T; if (SS.getScopeRep()) { if (CXXRecordDecl *Record = dyn_cast_or_null
(computeDeclContext(SS, true))) T = Context.getTypeDeclType(Record); else T = QualType(SS.getScopeRep()->getAsType(), 0); } // If we found an explicit specialization that prevents us from needing // 'template<>' headers, this will be set to the location of that // explicit specialization. SourceLocation ExplicitSpecLoc; while (!T.isNull()) { NestedTypes.push_back(T); // Retrieve the parent of a record type. if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) { // If this type is an explicit specialization, we're done. if (ClassTemplateSpecializationDecl *Spec = dyn_cast
(Record)) { if (!isa
(Spec) && Spec->getSpecializationKind() == TSK_ExplicitSpecialization) { ExplicitSpecLoc = Spec->getLocation(); break; } } else if (Record->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) { ExplicitSpecLoc = Record->getLocation(); break; } if (TypeDecl *Parent = dyn_cast
(Record->getParent())) T = Context.getTypeDeclType(Parent); else T = QualType(); continue; } if (const TemplateSpecializationType *TST = T->getAs
()) { if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) { if (TypeDecl *Parent = dyn_cast
(Template->getDeclContext())) T = Context.getTypeDeclType(Parent); else T = QualType(); continue; } } // Look one step prior in a dependent template specialization type. if (const DependentTemplateSpecializationType *DependentTST = T->getAs
()) { if (NestedNameSpecifier *NNS = DependentTST->getQualifier()) T = QualType(NNS->getAsType(), 0); else T = QualType(); continue; } // Look one step prior in a dependent name type. if (const DependentNameType *DependentName = T->getAs
()){ if (NestedNameSpecifier *NNS = DependentName->getQualifier()) T = QualType(NNS->getAsType(), 0); else T = QualType(); continue; } // Retrieve the parent of an enumeration type. if (const EnumType *EnumT = T->getAs
()) { // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization // check here. EnumDecl *Enum = EnumT->getDecl(); // Get to the parent type. if (TypeDecl *Parent = dyn_cast
(Enum->getParent())) T = Context.getTypeDeclType(Parent); else T = QualType(); continue; } T = QualType(); } // Reverse the nested types list, since we want to traverse from the outermost // to the innermost while checking template-parameter-lists. std::reverse(NestedTypes.begin(), NestedTypes.end()); // C++0x [temp.expl.spec]p17: // A member or a member template may be nested within many // enclosing class templates. In an explicit specialization for // such a member, the member declaration shall be preceded by a // template<> for each enclosing class template that is // explicitly specialized. bool SawNonEmptyTemplateParameterList = false; auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) { if (SawNonEmptyTemplateParameterList) { Diag(DeclLoc, diag::err_specialize_member_of_template) << !Recovery << Range; Invalid = true; IsExplicitSpecialization = false; return true; } return false; }; auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) { // Check that we can have an explicit specialization here. if (CheckExplicitSpecialization(Range, true)) return true; // We don't have a template header, but we should. SourceLocation ExpectedTemplateLoc; if (!ParamLists.empty()) ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc(); else ExpectedTemplateLoc = DeclStartLoc; Diag(DeclLoc, diag::err_template_spec_needs_header) << Range << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> "); return false; }; unsigned ParamIdx = 0; for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes; ++TypeIdx) { T = NestedTypes[TypeIdx]; // Whether we expect a 'template<>' header. bool NeedEmptyTemplateHeader = false; // Whether we expect a template header with parameters. bool NeedNonemptyTemplateHeader = false; // For a dependent type, the set of template parameters that we // expect to see. TemplateParameterList *ExpectedTemplateParams = nullptr; // C++0x [temp.expl.spec]p15: // A member or a member template may be nested within many enclosing // class templates. In an explicit specialization for such a member, the // member declaration shall be preceded by a template<> for each // enclosing class template that is explicitly specialized. if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) { if (ClassTemplatePartialSpecializationDecl *Partial = dyn_cast
(Record)) { ExpectedTemplateParams = Partial->getTemplateParameters(); NeedNonemptyTemplateHeader = true; } else if (Record->isDependentType()) { if (Record->getDescribedClassTemplate()) { ExpectedTemplateParams = Record->getDescribedClassTemplate() ->getTemplateParameters(); NeedNonemptyTemplateHeader = true; } } else if (ClassTemplateSpecializationDecl *Spec = dyn_cast
(Record)) { // C++0x [temp.expl.spec]p4: // Members of an explicitly specialized class template are defined // in the same manner as members of normal classes, and not using // the template<> syntax. if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization) NeedEmptyTemplateHeader = true; else continue; } else if (Record->getTemplateSpecializationKind()) { if (Record->getTemplateSpecializationKind() != TSK_ExplicitSpecialization && TypeIdx == NumTypes - 1) IsExplicitSpecialization = true; continue; } } else if (const TemplateSpecializationType *TST = T->getAs
()) { if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) { ExpectedTemplateParams = Template->getTemplateParameters(); NeedNonemptyTemplateHeader = true; } } else if (T->getAs
()) { // FIXME: We actually could/should check the template arguments here // against the corresponding template parameter list. NeedNonemptyTemplateHeader = false; } // C++ [temp.expl.spec]p16: // In an explicit specialization declaration for a member of a class // template or a member template that ap- pears in namespace scope, the // member template and some of its enclosing class templates may remain // unspecialized, except that the declaration shall not explicitly // specialize a class member template if its en- closing class templates // are not explicitly specialized as well. if (ParamIdx < ParamLists.size()) { if (ParamLists[ParamIdx]->size() == 0) { if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(), false)) return nullptr; } else SawNonEmptyTemplateParameterList = true; } if (NeedEmptyTemplateHeader) { // If we're on the last of the types, and we need a 'template<>' header // here, then it's an explicit specialization. if (TypeIdx == NumTypes - 1) IsExplicitSpecialization = true; if (ParamIdx < ParamLists.size()) { if (ParamLists[ParamIdx]->size() > 0) { // The header has template parameters when it shouldn't. Complain. Diag(ParamLists[ParamIdx]->getTemplateLoc(), diag::err_template_param_list_matches_nontemplate) << T << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(), ParamLists[ParamIdx]->getRAngleLoc()) << getRangeOfTypeInNestedNameSpecifier(Context, T, SS); Invalid = true; return nullptr; } // Consume this template header. ++ParamIdx; continue; } if (!IsFriend) if (DiagnoseMissingExplicitSpecialization( getRangeOfTypeInNestedNameSpecifier(Context, T, SS))) return nullptr; continue; } if (NeedNonemptyTemplateHeader) { // In friend declarations we can have template-ids which don't // depend on the corresponding template parameter lists. But // assume that empty parameter lists are supposed to match this // template-id. if (IsFriend && T->isDependentType()) { if (ParamIdx < ParamLists.size() && DependsOnTemplateParameters(T, ParamLists[ParamIdx])) ExpectedTemplateParams = nullptr; else continue; } if (ParamIdx < ParamLists.size()) { // Check the template parameter list, if we can. if (ExpectedTemplateParams && !TemplateParameterListsAreEqual(ParamLists[ParamIdx], ExpectedTemplateParams, true, TPL_TemplateMatch)) Invalid = true; if (!Invalid && CheckTemplateParameterList(ParamLists[ParamIdx], nullptr, TPC_ClassTemplateMember)) Invalid = true; ++ParamIdx; continue; } Diag(DeclLoc, diag::err_template_spec_needs_template_parameters) << T << getRangeOfTypeInNestedNameSpecifier(Context, T, SS); Invalid = true; continue; } } // If there were at least as many template-ids as there were template // parameter lists, then there are no template parameter lists remaining for // the declaration itself. if (ParamIdx >= ParamLists.size()) { if (TemplateId && !IsFriend) { // We don't have a template header for the declaration itself, but we // should. IsExplicitSpecialization = true; DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc, TemplateId->RAngleLoc)); // Fabricate an empty template parameter list for the invented header. return TemplateParameterList::Create(Context, SourceLocation(), SourceLocation(), nullptr, 0, SourceLocation()); } return nullptr; } // If there were too many template parameter lists, complain about that now. if (ParamIdx < ParamLists.size() - 1) { bool HasAnyExplicitSpecHeader = false; bool AllExplicitSpecHeaders = true; for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) { if (ParamLists[I]->size() == 0) HasAnyExplicitSpecHeader = true; else AllExplicitSpecHeaders = false; } Diag(ParamLists[ParamIdx]->getTemplateLoc(), AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers : diag::err_template_spec_extra_headers) << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(), ParamLists[ParamLists.size() - 2]->getRAngleLoc()); // If there was a specialization somewhere, such that 'template<>' is // not required, and there were any 'template<>' headers, note where the // specialization occurred. if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader) Diag(ExplicitSpecLoc, diag::note_explicit_template_spec_does_not_need_header) << NestedTypes.back(); // We have a template parameter list with no corresponding scope, which // means that the resulting template declaration can't be instantiated // properly (we'll end up with dependent nodes when we shouldn't). if (!AllExplicitSpecHeaders) Invalid = true; } // C++ [temp.expl.spec]p16: // In an explicit specialization declaration for a member of a class // template or a member template that ap- pears in namespace scope, the // member template and some of its enclosing class templates may remain // unspecialized, except that the declaration shall not explicitly // specialize a class member template if its en- closing class templates // are not explicitly specialized as well. if (ParamLists.back()->size() == 0 && CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(), false)) return nullptr; // Return the last template parameter list, which corresponds to the // entity being declared. return ParamLists.back(); } void Sema::NoteAllFoundTemplates(TemplateName Name) { if (TemplateDecl *Template = Name.getAsTemplateDecl()) { Diag(Template->getLocation(), diag::note_template_declared_here) << (isa
(Template) ? 0 : isa
(Template) ? 1 : isa
(Template) ? 2 : isa
(Template) ? 3 : 4) << Template->getDeclName(); return; } if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) { for (OverloadedTemplateStorage::iterator I = OST->begin(), IEnd = OST->end(); I != IEnd; ++I) Diag((*I)->getLocation(), diag::note_template_declared_here) << 0 << (*I)->getDeclName(); return; } } QualType Sema::CheckTemplateIdType(TemplateName Name, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs) { DependentTemplateName *DTN = Name.getUnderlying().getAsDependentTemplateName(); if (DTN && DTN->isIdentifier()) // When building a template-id where the template-name is dependent, // assume the template is a type template. Either our assumption is // correct, or the code is ill-formed and will be diagnosed when the // dependent name is substituted. return Context.getDependentTemplateSpecializationType(ETK_None, DTN->getQualifier(), DTN->getIdentifier(), TemplateArgs); TemplateDecl *Template = Name.getAsTemplateDecl(); if (!Template || isa
(Template) || isa
(Template)) { // We might have a substituted template template parameter pack. If so, // build a template specialization type for it. if (Name.getAsSubstTemplateTemplateParmPack()) return Context.getTemplateSpecializationType(Name, TemplateArgs); Diag(TemplateLoc, diag::err_template_id_not_a_type) << Name; NoteAllFoundTemplates(Name); return QualType(); } // Check that the template argument list is well-formed for this // template. SmallVector
Converted; if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs, false, Converted)) return QualType(); QualType CanonType; bool InstantiationDependent = false; if (TypeAliasTemplateDecl *AliasTemplate = dyn_cast
(Template)) { // Find the canonical type for this type alias template specialization. TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl(); if (Pattern->isInvalidDecl()) return QualType(); TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); // Only substitute for the innermost template argument list. MultiLevelTemplateArgumentList TemplateArgLists; TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth(); for (unsigned I = 0; I < Depth; ++I) TemplateArgLists.addOuterTemplateArguments(None); LocalInstantiationScope Scope(*this); InstantiatingTemplate Inst(*this, TemplateLoc, Template); if (Inst.isInvalid()) return QualType(); CanonType = SubstType(Pattern->getUnderlyingType(), TemplateArgLists, AliasTemplate->getLocation(), AliasTemplate->getDeclName()); if (CanonType.isNull()) return QualType(); } else if (Name.isDependent() || TemplateSpecializationType::anyDependentTemplateArguments( TemplateArgs, InstantiationDependent)) { // This class template specialization is a dependent // type. Therefore, its canonical type is another class template // specialization type that contains all of the converted // arguments in canonical form. This ensures that, e.g., A
and // A
have identical types when A is declared as: // // template
struct A; TemplateName CanonName = Context.getCanonicalTemplateName(Name); CanonType = Context.getTemplateSpecializationType(CanonName, Converted.data(), Converted.size()); // FIXME: CanonType is not actually the canonical type, and unfortunately // it is a TemplateSpecializationType that we will never use again. // In the future, we need to teach getTemplateSpecializationType to only // build the canonical type and return that to us. CanonType = Context.getCanonicalType(CanonType); // This might work out to be a current instantiation, in which // case the canonical type needs to be the InjectedClassNameType. // // TODO: in theory this could be a simple hashtable lookup; most // changes to CurContext don't change the set of current // instantiations. if (isa
(Template)) { for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) { // If we get out to a namespace, we're done. if (Ctx->isFileContext()) break; // If this isn't a record, keep looking. CXXRecordDecl *Record = dyn_cast
(Ctx); if (!Record) continue; // Look for one of the two cases with InjectedClassNameTypes // and check whether it's the same template. if (!isa
(Record) && !Record->getDescribedClassTemplate()) continue; // Fetch the injected class name type and check whether its // injected type is equal to the type we just built. QualType ICNT = Context.getTypeDeclType(Record); QualType Injected = cast
(ICNT) ->getInjectedSpecializationType(); if (CanonType != Injected->getCanonicalTypeInternal()) continue; // If so, the canonical type of this TST is the injected // class name type of the record we just found. assert(ICNT.isCanonical()); CanonType = ICNT; break; } } } else if (ClassTemplateDecl *ClassTemplate = dyn_cast
(Template)) { // Find the class template specialization declaration that // corresponds to these arguments. void *InsertPos = nullptr; ClassTemplateSpecializationDecl *Decl = ClassTemplate->findSpecialization(Converted, InsertPos); if (!Decl) { // This is the first time we have referenced this class template // specialization. Create the canonical declaration and add it to // the set of specializations. Decl = ClassTemplateSpecializationDecl::Create(Context, ClassTemplate->getTemplatedDecl()->getTagKind(), ClassTemplate->getDeclContext(), ClassTemplate->getTemplatedDecl()->getLocStart(), ClassTemplate->getLocation(), ClassTemplate, Converted.data(), Converted.size(), nullptr); ClassTemplate->AddSpecialization(Decl, InsertPos); if (ClassTemplate->isOutOfLine()) Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext()); } // Diagnose uses of this specialization. (void)DiagnoseUseOfDecl(Decl, TemplateLoc); CanonType = Context.getTypeDeclType(Decl); assert(isa
(CanonType) && "type of non-dependent specialization is not a RecordType"); } // Build the fully-sugared type for this class template // specialization, which refers back to the class template // specialization we created or found. return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType); } TypeResult Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc, TemplateTy TemplateD, SourceLocation TemplateLoc, SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc, bool IsCtorOrDtorName) { if (SS.isInvalid()) return true; TemplateName Template = TemplateD.get(); // Translate the parser's template argument list in our AST format. TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); translateTemplateArguments(TemplateArgsIn, TemplateArgs); if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) { QualType T = Context.getDependentTemplateSpecializationType(ETK_None, DTN->getQualifier(), DTN->getIdentifier(), TemplateArgs); // Build type-source information. TypeLocBuilder TLB; DependentTemplateSpecializationTypeLoc SpecTL = TLB.push
(T); SpecTL.setElaboratedKeywordLoc(SourceLocation()); SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I) SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T)); } QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); if (Result.isNull()) return true; // Build type-source information. TypeLocBuilder TLB; TemplateSpecializationTypeLoc SpecTL = TLB.push
(Result); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i) SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); // NOTE: avoid constructing an ElaboratedTypeLoc if this is a // constructor or destructor name (in such a case, the scope specifier // will be attached to the enclosing Decl or Expr node). if (SS.isNotEmpty() && !IsCtorOrDtorName) { // Create an elaborated-type-specifier containing the nested-name-specifier. Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result); ElaboratedTypeLoc ElabTL = TLB.push
(Result); ElabTL.setElaboratedKeywordLoc(SourceLocation()); ElabTL.setQualifierLoc(SS.getWithLocInContext(Context)); } return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result)); } TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK, TypeSpecifierType TagSpec, SourceLocation TagLoc, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, TemplateTy TemplateD, SourceLocation TemplateLoc, SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc) { TemplateName Template = TemplateD.get(); // Translate the parser's template argument list in our AST format. TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc); translateTemplateArguments(TemplateArgsIn, TemplateArgs); // Determine the tag kind TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec); ElaboratedTypeKeyword Keyword = TypeWithKeyword::getKeywordForTagTypeKind(TagKind); if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) { QualType T = Context.getDependentTemplateSpecializationType(Keyword, DTN->getQualifier(), DTN->getIdentifier(), TemplateArgs); // Build type-source information. TypeLocBuilder TLB; DependentTemplateSpecializationTypeLoc SpecTL = TLB.push
(T); SpecTL.setElaboratedKeywordLoc(TagLoc); SpecTL.setQualifierLoc(SS.getWithLocInContext(Context)); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I) SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo()); return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T)); } if (TypeAliasTemplateDecl *TAT = dyn_cast_or_null
(Template.getAsTemplateDecl())) { // C++0x [dcl.type.elab]p2: // If the identifier resolves to a typedef-name or the simple-template-id // resolves to an alias template specialization, the // elaborated-type-specifier is ill-formed. Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4; Diag(TAT->getLocation(), diag::note_declared_at); } QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs); if (Result.isNull()) return TypeResult(true); // Check the tag kind if (const RecordType *RT = Result->getAs
()) { RecordDecl *D = RT->getDecl(); IdentifierInfo *Id = D->getIdentifier(); assert(Id && "templated class must have an identifier"); if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition, TagLoc, *Id)) { Diag(TagLoc, diag::err_use_with_wrong_tag) << Result << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName()); Diag(D->getLocation(), diag::note_previous_use); } } // Provide source-location information for the template specialization. TypeLocBuilder TLB; TemplateSpecializationTypeLoc SpecTL = TLB.push
(Result); SpecTL.setTemplateKeywordLoc(TemplateKWLoc); SpecTL.setTemplateNameLoc(TemplateLoc); SpecTL.setLAngleLoc(LAngleLoc); SpecTL.setRAngleLoc(RAngleLoc); for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i) SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo()); // Construct an elaborated type containing the nested-name-specifier (if any) // and tag keyword. Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result); ElaboratedTypeLoc ElabTL = TLB.push
(Result); ElabTL.setElaboratedKeywordLoc(TagLoc); ElabTL.setQualifierLoc(SS.getWithLocInContext(Context)); return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result)); } static bool CheckTemplatePartialSpecializationArgs( Sema &S, SourceLocation NameLoc, TemplateParameterList *TemplateParams, unsigned ExplicitArgs, SmallVectorImpl
&TemplateArgs); static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized, NamedDecl *PrevDecl, SourceLocation Loc, bool IsPartialSpecialization); static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D); static bool isTemplateArgumentTemplateParameter( const TemplateArgument &Arg, unsigned Depth, unsigned Index) { switch (Arg.getKind()) { case TemplateArgument::Null: case TemplateArgument::NullPtr: case TemplateArgument::Integral: case TemplateArgument::Declaration: case TemplateArgument::Pack: case TemplateArgument::TemplateExpansion: return false; case TemplateArgument::Type: { QualType Type = Arg.getAsType(); const TemplateTypeParmType *TPT = Arg.getAsType()->getAs
(); return TPT && !Type.hasQualifiers() && TPT->getDepth() == Depth && TPT->getIndex() == Index; } case TemplateArgument::Expression: { DeclRefExpr *DRE = dyn_cast
(Arg.getAsExpr()); if (!DRE || !DRE->getDecl()) return false; const NonTypeTemplateParmDecl *NTTP = dyn_cast
(DRE->getDecl()); return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index; } case TemplateArgument::Template: const TemplateTemplateParmDecl *TTP = dyn_cast_or_null
( Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl()); return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index; } llvm_unreachable("unexpected kind of template argument"); } static bool isSameAsPrimaryTemplate(TemplateParameterList *Params, ArrayRef
Args) { if (Params->size() != Args.size()) return false; unsigned Depth = Params->getDepth(); for (unsigned I = 0, N = Args.size(); I != N; ++I) { TemplateArgument Arg = Args[I]; // If the parameter is a pack expansion, the argument must be a pack // whose only element is a pack expansion. if (Params->getParam(I)->isParameterPack()) { if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 || !Arg.pack_begin()->isPackExpansion()) return false; Arg = Arg.pack_begin()->getPackExpansionPattern(); } if (!isTemplateArgumentTemplateParameter(Arg, Depth, I)) return false; } return true; } /// Convert the parser's template argument list representation into our form. static TemplateArgumentListInfo makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) { TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc, TemplateId.RAngleLoc); ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(), TemplateId.NumArgs); S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs); return TemplateArgs; } DeclResult Sema::ActOnVarTemplateSpecialization( Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc, TemplateParameterList *TemplateParams, VarDecl::StorageClass SC, bool IsPartialSpecialization) { // D must be variable template id. assert(D.getName().getKind() == UnqualifiedId::IK_TemplateId && "Variable template specialization is declared with a template it."); TemplateIdAnnotation *TemplateId = D.getName().TemplateId; TemplateArgumentListInfo TemplateArgs = makeTemplateArgumentListInfo(*this, *TemplateId); SourceLocation TemplateNameLoc = D.getIdentifierLoc(); SourceLocation LAngleLoc = TemplateId->LAngleLoc; SourceLocation RAngleLoc = TemplateId->RAngleLoc; TemplateName Name = TemplateId->Template.get(); // The template-id must name a variable template. VarTemplateDecl *VarTemplate = dyn_cast_or_null
(Name.getAsTemplateDecl()); if (!VarTemplate) { NamedDecl *FnTemplate; if (auto *OTS = Name.getAsOverloadedTemplate()) FnTemplate = *OTS->begin(); else FnTemplate = dyn_cast_or_null
(Name.getAsTemplateDecl()); if (FnTemplate) return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method) << FnTemplate->getDeclName(); return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template) << IsPartialSpecialization; } // Check for unexpanded parameter packs in any of the template arguments. for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I) if (DiagnoseUnexpandedParameterPack(TemplateArgs[I], UPPC_PartialSpecialization)) return true; // Check that the template argument list is well-formed for this // template. SmallVector
Converted; if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs, false, Converted)) return true; // Check that the type of this variable template specialization // matches the expected type. TypeSourceInfo *ExpectedDI; { // Do substitution on the type of the declaration TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); InstantiatingTemplate Inst(*this, TemplateKWLoc, VarTemplate); if (Inst.isInvalid()) return true; VarDecl *Templated = VarTemplate->getTemplatedDecl(); ExpectedDI = SubstType(Templated->getTypeSourceInfo(), MultiLevelTemplateArgumentList(TemplateArgList), Templated->getTypeSpecStartLoc(), Templated->getDeclName()); } if (!ExpectedDI) return true; // Find the variable template (partial) specialization declaration that // corresponds to these arguments. if (IsPartialSpecialization) { if (CheckTemplatePartialSpecializationArgs( *this, TemplateNameLoc, VarTemplate->getTemplateParameters(), TemplateArgs.size(), Converted)) return true; bool InstantiationDependent; if (!Name.isDependent() && !TemplateSpecializationType::anyDependentTemplateArguments( TemplateArgs.getArgumentArray(), TemplateArgs.size(), InstantiationDependent)) { Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized) << VarTemplate->getDeclName(); IsPartialSpecialization = false; } if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(), Converted)) { // C++ [temp.class.spec]p9b3: // // -- The argument list of the specialization shall not be identical // to the implicit argument list of the primary template. Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template) << /*variable template*/ 1 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord()) << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc)); // FIXME: Recover from this by treating the declaration as a redeclaration // of the primary template. return true; } } void *InsertPos = nullptr; VarTemplateSpecializationDecl *PrevDecl = nullptr; if (IsPartialSpecialization) // FIXME: Template parameter list matters too PrevDecl = VarTemplate->findPartialSpecialization(Converted, InsertPos); else PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos); VarTemplateSpecializationDecl *Specialization = nullptr; // Check whether we can declare a variable template specialization in // the current scope. if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl, TemplateNameLoc, IsPartialSpecialization)) return true; if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) { // Since the only prior variable template specialization with these // arguments was referenced but not declared, reuse that // declaration node as our own, updating its source location and // the list of outer template parameters to reflect our new declaration. Specialization = PrevDecl; Specialization->setLocation(TemplateNameLoc); PrevDecl = nullptr; } else if (IsPartialSpecialization) { // Create a new class template partial specialization declaration node. VarTemplatePartialSpecializationDecl *PrevPartial = cast_or_null
(PrevDecl); VarTemplatePartialSpecializationDecl *Partial = VarTemplatePartialSpecializationDecl::Create( Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC, Converted.data(), Converted.size(), TemplateArgs); if (!PrevPartial) VarTemplate->AddPartialSpecialization(Partial, InsertPos); Specialization = Partial; // If we are providing an explicit specialization of a member variable // template specialization, make a note of that. if (PrevPartial && PrevPartial->getInstantiatedFromMember()) PrevPartial->setMemberSpecialization(); // Check that all of the template parameters of the variable template // partial specialization are deducible from the template // arguments. If not, this variable template partial specialization // will never be used. llvm::SmallBitVector DeducibleParams(TemplateParams->size()); MarkUsedTemplateParameters(Partial->getTemplateArgs(), true, TemplateParams->getDepth(), DeducibleParams); if (!DeducibleParams.all()) { unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count(); Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible) << /*variable template*/ 1 << (NumNonDeducible > 1) << SourceRange(TemplateNameLoc, RAngleLoc); for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) { if (!DeducibleParams[I]) { NamedDecl *Param = cast
(TemplateParams->getParam(I)); if (Param->getDeclName()) Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter) << Param->getDeclName(); else Diag(Param->getLocation(), diag::note_partial_spec_unused_parameter) << "(anonymous)"; } } } } else { // Create a new class template specialization declaration node for // this explicit specialization or friend declaration. Specialization = VarTemplateSpecializationDecl::Create( Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc, VarTemplate, DI->getType(), DI, SC, Converted.data(), Converted.size()); Specialization->setTemplateArgsInfo(TemplateArgs); if (!PrevDecl) VarTemplate->AddSpecialization(Specialization, InsertPos); } // C++ [temp.expl.spec]p6: // If a template, a member template or the member of a class template is // explicitly specialized then that specialization shall be declared // before the first use of that specialization that would cause an implicit // instantiation to take place, in every translation unit in which such a // use occurs; no diagnostic is required. if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) { bool Okay = false; for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) { // Is there any previous explicit specialization declaration? if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) { Okay = true; break; } } if (!Okay) { SourceRange Range(TemplateNameLoc, RAngleLoc); Diag(TemplateNameLoc, diag::err_specialization_after_instantiation) << Name << Range; Diag(PrevDecl->getPointOfInstantiation(), diag::note_instantiation_required_here) << (PrevDecl->getTemplateSpecializationKind() != TSK_ImplicitInstantiation); return true; } } Specialization->setTemplateKeywordLoc(TemplateKWLoc); Specialization->setLexicalDeclContext(CurContext); // Add the specialization into its lexical context, so that it can // be seen when iterating through the list of declarations in that // context. However, specializations are not found by name lookup. CurContext->addDecl(Specialization); // Note that this is an explicit specialization. Specialization->setSpecializationKind(TSK_ExplicitSpecialization); if (PrevDecl) { // Check that this isn't a redefinition of this specialization, // merging with previous declarations. LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName, ForRedeclaration); PrevSpec.addDecl(PrevDecl); D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec)); } else if (Specialization->isStaticDataMember() && Specialization->isOutOfLine()) { Specialization->setAccess(VarTemplate->getAccess()); } // Link instantiations of static data members back to the template from // which they were instantiated. if (Specialization->isStaticDataMember()) Specialization->setInstantiationOfStaticDataMember( VarTemplate->getTemplatedDecl(), Specialization->getSpecializationKind()); return Specialization; } namespace { /// \brief A partial specialization whose template arguments have matched /// a given template-id. struct PartialSpecMatchResult { VarTemplatePartialSpecializationDecl *Partial; TemplateArgumentList *Args; }; } DeclResult Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc, SourceLocation TemplateNameLoc, const TemplateArgumentListInfo &TemplateArgs) { assert(Template && "A variable template id without template?"); // Check that the template argument list is well-formed for this template. SmallVector
Converted; if (CheckTemplateArgumentList( Template, TemplateNameLoc, const_cast
(TemplateArgs), false, Converted)) return true; // Find the variable template specialization declaration that // corresponds to these arguments. void *InsertPos = nullptr; if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization( Converted, InsertPos)) // If we already have a variable template specialization, return it. return Spec; // This is the first time we have referenced this variable template // specialization. Create the canonical declaration and add it to // the set of specializations, based on the closest partial specialization // that it represents. That is, VarDecl *InstantiationPattern = Template->getTemplatedDecl(); TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); TemplateArgumentList *InstantiationArgs = &TemplateArgList; bool AmbiguousPartialSpec = false; typedef PartialSpecMatchResult MatchResult; SmallVector
Matched; SourceLocation PointOfInstantiation = TemplateNameLoc; TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation); // 1. Attempt to find the closest partial specialization that this // specializes, if any. // If any of the template arguments is dependent, then this is probably // a placeholder for an incomplete declarative context; which must be // complete by instantiation time. Thus, do not search through the partial // specializations yet. // TODO: Unify with InstantiateClassTemplateSpecialization()? // Perhaps better after unification of DeduceTemplateArguments() and // getMoreSpecializedPartialSpecialization(). bool InstantiationDependent = false; if (!TemplateSpecializationType::anyDependentTemplateArguments( TemplateArgs, InstantiationDependent)) { SmallVector
PartialSpecs; Template->getPartialSpecializations(PartialSpecs); for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) { VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I]; TemplateDeductionInfo Info(FailedCandidates.getLocation()); if (TemplateDeductionResult Result = DeduceTemplateArguments(Partial, TemplateArgList, Info)) { // Store the failed-deduction information for use in diagnostics, later. // TODO: Actually use the failed-deduction info? FailedCandidates.addCandidate() .set(Partial, MakeDeductionFailureInfo(Context, Result, Info)); (void)Result; } else { Matched.push_back(PartialSpecMatchResult()); Matched.back().Partial = Partial; Matched.back().Args = Info.take(); } } if (Matched.size() >= 1) { SmallVector
::iterator Best = Matched.begin(); if (Matched.size() == 1) { // -- If exactly one matching specialization is found, the // instantiation is generated from that specialization. // We don't need to do anything for this. } else { // -- If more than one matching specialization is found, the // partial order rules (14.5.4.2) are used to determine // whether one of the specializations is more specialized // than the others. If none of the specializations is more // specialized than all of the other matching // specializations, then the use of the variable template is // ambiguous and the program is ill-formed. for (SmallVector
::iterator P = Best + 1, PEnd = Matched.end(); P != PEnd; ++P) { if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial, PointOfInstantiation) == P->Partial) Best = P; } // Determine if the best partial specialization is more specialized than // the others. for (SmallVector
::iterator P = Matched.begin(), PEnd = Matched.end(); P != PEnd; ++P) { if (P != Best && getMoreSpecializedPartialSpecialization( P->Partial, Best->Partial, PointOfInstantiation) != Best->Partial) { AmbiguousPartialSpec = true; break; } } } // Instantiate using the best variable template partial specialization. InstantiationPattern = Best->Partial; InstantiationArgs = Best->Args; } else { // -- If no match is found, the instantiation is generated // from the primary template. // InstantiationPattern = Template->getTemplatedDecl(); } } // 2. Create the canonical declaration. // Note that we do not instantiate the variable just yet, since // instantiation is handled in DoMarkVarDeclReferenced(). // FIXME: LateAttrs et al.? VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation( Template, InstantiationPattern, *InstantiationArgs, TemplateArgs, Converted, TemplateNameLoc, InsertPos /*, LateAttrs, StartingScope*/); if (!Decl) return true; if (AmbiguousPartialSpec) { // Partial ordering did not produce a clear winner. Complain. Decl->setInvalidDecl(); Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous) << Decl; // Print the matching partial specializations. for (SmallVector
::iterator P = Matched.begin(), PEnd = Matched.end(); P != PEnd; ++P) Diag(P->Partial->getLocation(), diag::note_partial_spec_match) << getTemplateArgumentBindingsText( P->Partial->getTemplateParameters(), *P->Args); return true; } if (VarTemplatePartialSpecializationDecl *D = dyn_cast
(InstantiationPattern)) Decl->setInstantiationOf(D, InstantiationArgs); assert(Decl && "No variable template specialization?"); return Decl; } ExprResult Sema::CheckVarTemplateId(const CXXScopeSpec &SS, const DeclarationNameInfo &NameInfo, VarTemplateDecl *Template, SourceLocation TemplateLoc, const TemplateArgumentListInfo *TemplateArgs) { DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(), *TemplateArgs); if (Decl.isInvalid()) return ExprError(); VarDecl *Var = cast
(Decl.get()); if (!Var->getTemplateSpecializationKind()) Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation, NameInfo.getLoc()); // Build an ordinary singleton decl ref. return BuildDeclarationNameExpr(SS, NameInfo, Var, /*FoundD=*/nullptr, TemplateArgs); } ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS, SourceLocation TemplateKWLoc, LookupResult &R, bool RequiresADL, const TemplateArgumentListInfo *TemplateArgs) { // FIXME: Can we do any checking at this point? I guess we could check the // template arguments that we have against the template name, if the template // name refers to a single template. That's not a terribly common case, // though. // foo
could identify a single function unambiguously // This approach does NOT work, since f
(1); // gets resolved prior to resorting to overload resolution // i.e., template
void f(double); // vs template
void f(U); // These should be filtered out by our callers. assert(!R.empty() && "empty lookup results when building templateid"); assert(!R.isAmbiguous() && "ambiguous lookup when building templateid"); // In C++1y, check variable template ids. bool InstantiationDependent; if (R.getAsSingle
() && !TemplateSpecializationType::anyDependentTemplateArguments( *TemplateArgs, InstantiationDependent)) { return CheckVarTemplateId(SS, R.getLookupNameInfo(), R.getAsSingle
(), TemplateKWLoc, TemplateArgs); } // We don't want lookup warnings at this point. R.suppressDiagnostics(); UnresolvedLookupExpr *ULE = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), SS.getWithLocInContext(Context), TemplateKWLoc, R.getLookupNameInfo(), RequiresADL, TemplateArgs, R.begin(), R.end()); return ULE; } // We actually only call this from template instantiation. ExprResult Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS, SourceLocation TemplateKWLoc, const DeclarationNameInfo &NameInfo, const TemplateArgumentListInfo *TemplateArgs) { assert(TemplateArgs || TemplateKWLoc.isValid()); DeclContext *DC; if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext() || RequireCompleteDeclContext(SS, DC)) return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs); bool MemberOfUnknownSpecialization; LookupResult R(*this, NameInfo, LookupOrdinaryName); LookupTemplateName(R, (Scope*)nullptr, SS, QualType(), /*Entering*/ false, MemberOfUnknownSpecialization); if (R.isAmbiguous()) return ExprError(); if (R.empty()) { Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template) << NameInfo.getName() << SS.getRange(); return ExprError(); } if (ClassTemplateDecl *Temp = R.getAsSingle
()) { Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template) << SS.getScopeRep() << NameInfo.getName().getAsString() << SS.getRange(); Diag(Temp->getLocation(), diag::note_referenced_class_template); return ExprError(); } return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs); } /// \brief Form a dependent template name. /// /// This action forms a dependent template name given the template /// name and its (presumably dependent) scope specifier. For /// example, given "MetaFun::template apply", the scope specifier \p /// SS will be "MetaFun::", \p TemplateKWLoc contains the location /// of the "template" keyword, and "apply" is the \p Name. TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc, UnqualifiedId &Name, ParsedType ObjectType, bool EnteringContext, TemplateTy &Result) { if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent()) Diag(TemplateKWLoc, getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_outside_of_template : diag::ext_template_outside_of_template) << FixItHint::CreateRemoval(TemplateKWLoc); DeclContext *LookupCtx = nullptr; if (SS.isSet()) LookupCtx = computeDeclContext(SS, EnteringContext); if (!LookupCtx && ObjectType) LookupCtx = computeDeclContext(ObjectType.get()); if (LookupCtx) { // C++0x [temp.names]p5: // If a name prefixed by the keyword template is not the name of // a template, the program is ill-formed. [Note: the keyword // template may not be applied to non-template members of class // templates. -end note ] [ Note: as is the case with the // typename prefix, the template prefix is allowed in cases // where it is not strictly necessary; i.e., when the // nested-name-specifier or the expression on the left of the -> // or . is not dependent on a template-parameter, or the use // does not appear in the scope of a template. -end note] // // Note: C++03 was more strict here, because it banned the use of // the "template" keyword prior to a template-name that was not a // dependent name. C++ DR468 relaxed this requirement (the // "template" keyword is now permitted). We follow the C++0x // rules, even in C++03 mode with a warning, retroactively applying the DR. bool MemberOfUnknownSpecialization; TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name, ObjectType, EnteringContext, Result, MemberOfUnknownSpecialization); if (TNK == TNK_Non_template && LookupCtx->isDependentContext() && isa
(LookupCtx) && (!cast
(LookupCtx)->hasDefinition() || cast
(LookupCtx)->hasAnyDependentBases())) { // This is a dependent template. Handle it below. } else if (TNK == TNK_Non_template) { Diag(Name.getLocStart(), diag::err_template_kw_refers_to_non_template) << GetNameFromUnqualifiedId(Name).getName() << Name.getSourceRange() << TemplateKWLoc; return TNK_Non_template; } else { // We found something; return it. return TNK; } } NestedNameSpecifier *Qualifier = SS.getScopeRep(); switch (Name.getKind()) { case UnqualifiedId::IK_Identifier: Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, Name.Identifier)); return TNK_Dependent_template_name; case UnqualifiedId::IK_OperatorFunctionId: Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier, Name.OperatorFunctionId.Operator)); return TNK_Function_template; case UnqualifiedId::IK_LiteralOperatorId: llvm_unreachable("literal operator id cannot have a dependent scope"); default: break; } Diag(Name.getLocStart(), diag::err_template_kw_refers_to_non_template) << GetNameFromUnqualifiedId(Name).getName() << Name.getSourceRange() << TemplateKWLoc; return TNK_Non_template; } bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param, TemplateArgumentLoc &AL, SmallVectorImpl
&Converted) { const TemplateArgument &Arg = AL.getArgument(); QualType ArgType; TypeSourceInfo *TSI = nullptr; // Check template type parameter. switch(Arg.getKind()) { case TemplateArgument::Type: // C++ [temp.arg.type]p1: // A template-argument for a template-parameter which is a // type shall be a type-id. ArgType = Arg.getAsType(); TSI = AL.getTypeSourceInfo(); break; case TemplateArgument::Template: { // We have a template type parameter but the template argument // is a template without any arguments. SourceRange SR = AL.getSourceRange(); TemplateName Name = Arg.getAsTemplate(); Diag(SR.getBegin(), diag::err_template_missing_args) << Name << SR; if (TemplateDecl *Decl = Name.getAsTemplateDecl()) Diag(Decl->getLocation(), diag::note_template_decl_here); return true; } case TemplateArgument::Expression: { // We have a template type parameter but the template argument is an // expression; see if maybe it is missing the "typename" keyword. CXXScopeSpec SS; DeclarationNameInfo NameInfo; if (DeclRefExpr *ArgExpr = dyn_cast
(Arg.getAsExpr())) { SS.Adopt(ArgExpr->getQualifierLoc()); NameInfo = ArgExpr->getNameInfo(); } else if (DependentScopeDeclRefExpr *ArgExpr = dyn_cast
(Arg.getAsExpr())) { SS.Adopt(ArgExpr->getQualifierLoc()); NameInfo = ArgExpr->getNameInfo(); } else if (CXXDependentScopeMemberExpr *ArgExpr = dyn_cast
(Arg.getAsExpr())) { if (ArgExpr->isImplicitAccess()) { SS.Adopt(ArgExpr->getQualifierLoc()); NameInfo = ArgExpr->getMemberNameInfo(); } } if (auto *II = NameInfo.getName().getAsIdentifierInfo()) { LookupResult Result(*this, NameInfo, LookupOrdinaryName); LookupParsedName(Result, CurScope, &SS); if (Result.getAsSingle
() || Result.getResultKind() == LookupResult::NotFoundInCurrentInstantiation) { // Suggest that the user add 'typename' before the NNS. SourceLocation Loc = AL.getSourceRange().getBegin(); Diag(Loc, getLangOpts().MSVCCompat ? diag::ext_ms_template_type_arg_missing_typename : diag::err_template_arg_must_be_type_suggest) << FixItHint::CreateInsertion(Loc, "typename "); Diag(Param->getLocation(), diag::note_template_param_here); // Recover by synthesizing a type using the location information that we // already have. ArgType = Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II); TypeLocBuilder TLB; DependentNameTypeLoc TL = TLB.push
(ArgType); TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/)); TL.setQualifierLoc(SS.getWithLocInContext(Context)); TL.setNameLoc(NameInfo.getLoc()); TSI = TLB.getTypeSourceInfo(Context, ArgType); // Overwrite our input TemplateArgumentLoc so that we can recover // properly. AL = TemplateArgumentLoc(TemplateArgument(ArgType), TemplateArgumentLocInfo(TSI)); break; } } // fallthrough } default: { // We have a template type parameter but the template argument // is not a type. SourceRange SR = AL.getSourceRange(); Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR; Diag(Param->getLocation(), diag::note_template_param_here); return true; } } if (CheckTemplateArgument(Param, TSI)) return true; // Add the converted template type argument. ArgType = Context.getCanonicalType(ArgType); // Objective-C ARC: // If an explicitly-specified template argument type is a lifetime type // with no lifetime qualifier, the __strong lifetime qualifier is inferred. if (getLangOpts().ObjCAutoRefCount && ArgType->isObjCLifetimeType() && !ArgType.getObjCLifetime()) { Qualifiers Qs; Qs.setObjCLifetime(Qualifiers::OCL_Strong); ArgType = Context.getQualifiedType(ArgType, Qs); } Converted.push_back(TemplateArgument(ArgType)); return false; } /// \brief Substitute template arguments into the default template argument for /// the given template type parameter. /// /// \param SemaRef the semantic analysis object for which we are performing /// the substitution. /// /// \param Template the template that we are synthesizing template arguments /// for. /// /// \param TemplateLoc the location of the template name that started the /// template-id we are checking. /// /// \param RAngleLoc the location of the right angle bracket ('>') that /// terminates the template-id. /// /// \param Param the template template parameter whose default we are /// substituting into. /// /// \param Converted the list of template arguments provided for template /// parameters that precede \p Param in the template parameter list. /// \returns the substituted template argument, or NULL if an error occurred. static TypeSourceInfo * SubstDefaultTemplateArgument(Sema &SemaRef, TemplateDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, TemplateTypeParmDecl *Param, SmallVectorImpl
&Converted) { TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo(); // If the argument type is dependent, instantiate it now based // on the previously-computed template arguments. if (ArgType->getType()->isDependentType()) { Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return nullptr; TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); // Only substitute for the innermost template argument list. MultiLevelTemplateArgumentList TemplateArgLists; TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) TemplateArgLists.addOuterTemplateArguments(None); Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); ArgType = SemaRef.SubstType(ArgType, TemplateArgLists, Param->getDefaultArgumentLoc(), Param->getDeclName()); } return ArgType; } /// \brief Substitute template arguments into the default template argument for /// the given non-type template parameter. /// /// \param SemaRef the semantic analysis object for which we are performing /// the substitution. /// /// \param Template the template that we are synthesizing template arguments /// for. /// /// \param TemplateLoc the location of the template name that started the /// template-id we are checking. /// /// \param RAngleLoc the location of the right angle bracket ('>') that /// terminates the template-id. /// /// \param Param the non-type template parameter whose default we are /// substituting into. /// /// \param Converted the list of template arguments provided for template /// parameters that precede \p Param in the template parameter list. /// /// \returns the substituted template argument, or NULL if an error occurred. static ExprResult SubstDefaultTemplateArgument(Sema &SemaRef, TemplateDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, NonTypeTemplateParmDecl *Param, SmallVectorImpl
&Converted) { Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return ExprError(); TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); // Only substitute for the innermost template argument list. MultiLevelTemplateArgumentList TemplateArgLists; TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) TemplateArgLists.addOuterTemplateArguments(None); Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated); return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists); } /// \brief Substitute template arguments into the default template argument for /// the given template template parameter. /// /// \param SemaRef the semantic analysis object for which we are performing /// the substitution. /// /// \param Template the template that we are synthesizing template arguments /// for. /// /// \param TemplateLoc the location of the template name that started the /// template-id we are checking. /// /// \param RAngleLoc the location of the right angle bracket ('>') that /// terminates the template-id. /// /// \param Param the template template parameter whose default we are /// substituting into. /// /// \param Converted the list of template arguments provided for template /// parameters that precede \p Param in the template parameter list. /// /// \param QualifierLoc Will be set to the nested-name-specifier (with /// source-location information) that precedes the template name. /// /// \returns the substituted template argument, or NULL if an error occurred. static TemplateName SubstDefaultTemplateArgument(Sema &SemaRef, TemplateDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, TemplateTemplateParmDecl *Param, SmallVectorImpl
&Converted, NestedNameSpecifierLoc &QualifierLoc) { Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc, Template, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return TemplateName(); TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); // Only substitute for the innermost template argument list. MultiLevelTemplateArgumentList TemplateArgLists; TemplateArgLists.addOuterTemplateArguments(&TemplateArgs); for (unsigned i = 0, e = Param->getDepth(); i != e; ++i) TemplateArgLists.addOuterTemplateArguments(None); Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext()); // Substitute into the nested-name-specifier first, QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc(); if (QualifierLoc) { QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists); if (!QualifierLoc) return TemplateName(); } return SemaRef.SubstTemplateName( QualifierLoc, Param->getDefaultArgument().getArgument().getAsTemplate(), Param->getDefaultArgument().getTemplateNameLoc(), TemplateArgLists); } /// \brief If the given template parameter has a default template /// argument, substitute into that default template argument and /// return the corresponding template argument. TemplateArgumentLoc Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, Decl *Param, SmallVectorImpl
&Converted, bool &HasDefaultArg) { HasDefaultArg = false; if (TemplateTypeParmDecl *TypeParm = dyn_cast
(Param)) { if (!TypeParm->hasDefaultArgument()) return TemplateArgumentLoc(); HasDefaultArg = true; TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, TypeParm, Converted); if (DI) return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI); return TemplateArgumentLoc(); } if (NonTypeTemplateParmDecl *NonTypeParm = dyn_cast
(Param)) { if (!NonTypeParm->hasDefaultArgument()) return TemplateArgumentLoc(); HasDefaultArg = true; ExprResult Arg = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, NonTypeParm, Converted); if (Arg.isInvalid()) return TemplateArgumentLoc(); Expr *ArgE = Arg.getAs
(); return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE); } TemplateTemplateParmDecl *TempTempParm = cast
(Param); if (!TempTempParm->hasDefaultArgument()) return TemplateArgumentLoc(); HasDefaultArg = true; NestedNameSpecifierLoc QualifierLoc; TemplateName TName = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, TempTempParm, Converted, QualifierLoc); if (TName.isNull()) return TemplateArgumentLoc(); return TemplateArgumentLoc(TemplateArgument(TName), TempTempParm->getDefaultArgument().getTemplateQualifierLoc(), TempTempParm->getDefaultArgument().getTemplateNameLoc()); } /// \brief Check that the given template argument corresponds to the given /// template parameter. /// /// \param Param The template parameter against which the argument will be /// checked. /// /// \param Arg The template argument. /// /// \param Template The template in which the template argument resides. /// /// \param TemplateLoc The location of the template name for the template /// whose argument list we're matching. /// /// \param RAngleLoc The location of the right angle bracket ('>') that closes /// the template argument list. /// /// \param ArgumentPackIndex The index into the argument pack where this /// argument will be placed. Only valid if the parameter is a parameter pack. /// /// \param Converted The checked, converted argument will be added to the /// end of this small vector. /// /// \param CTAK Describes how we arrived at this particular template argument: /// explicitly written, deduced, etc. /// /// \returns true on error, false otherwise. bool Sema::CheckTemplateArgument(NamedDecl *Param, TemplateArgumentLoc &Arg, NamedDecl *Template, SourceLocation TemplateLoc, SourceLocation RAngleLoc, unsigned ArgumentPackIndex, SmallVectorImpl
&Converted, CheckTemplateArgumentKind CTAK) { // Check template type parameters. if (TemplateTypeParmDecl *TTP = dyn_cast
(Param)) return CheckTemplateTypeArgument(TTP, Arg, Converted); // Check non-type template parameters. if (NonTypeTemplateParmDecl *NTTP =dyn_cast
(Param)) { // Do substitution on the type of the non-type template parameter // with the template arguments we've seen thus far. But if the // template has a dependent context then we cannot substitute yet. QualType NTTPType = NTTP->getType(); if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack()) NTTPType = NTTP->getExpansionType(ArgumentPackIndex); if (NTTPType->isDependentType() && !isa
(Template) && !Template->getDeclContext()->isDependentContext()) { // Do substitution on the type of the non-type template parameter. InstantiatingTemplate Inst(*this, TemplateLoc, Template, NTTP, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return true; TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); NTTPType = SubstType(NTTPType, MultiLevelTemplateArgumentList(TemplateArgs), NTTP->getLocation(), NTTP->getDeclName()); // If that worked, check the non-type template parameter type // for validity. if (!NTTPType.isNull()) NTTPType = CheckNonTypeTemplateParameterType(NTTPType, NTTP->getLocation()); if (NTTPType.isNull()) return true; } switch (Arg.getArgument().getKind()) { case TemplateArgument::Null: llvm_unreachable("Should never see a NULL template argument here"); case TemplateArgument::Expression: { TemplateArgument Result; ExprResult Res = CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(), Result, CTAK); if (Res.isInvalid()) return true; Converted.push_back(Result); break; } case TemplateArgument::Declaration: case TemplateArgument::Integral: case TemplateArgument::NullPtr: // We've already checked this template argument, so just copy // it to the list of converted arguments. Converted.push_back(Arg.getArgument()); break; case TemplateArgument::Template: case TemplateArgument::TemplateExpansion: // We were given a template template argument. It may not be ill-formed; // see below. if (DependentTemplateName *DTN = Arg.getArgument().getAsTemplateOrTemplatePattern() .getAsDependentTemplateName()) { // We have a template argument such as \c T::template X, which we // parsed as a template template argument. However, since we now // know that we need a non-type template argument, convert this // template name into an expression. DeclarationNameInfo NameInfo(DTN->getIdentifier(), Arg.getTemplateNameLoc()); CXXScopeSpec SS; SS.Adopt(Arg.getTemplateQualifierLoc()); // FIXME: the template-template arg was a DependentTemplateName, // so it was provided with a template keyword. However, its source // location is not stored in the template argument structure. SourceLocation TemplateKWLoc; ExprResult E = DependentScopeDeclRefExpr::Create( Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo, nullptr); // If we parsed the template argument as a pack expansion, create a // pack expansion expression. if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){ E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc()); if (E.isInvalid()) return true; } TemplateArgument Result; E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result); if (E.isInvalid()) return true; Converted.push_back(Result); break; } // We have a template argument that actually does refer to a class // template, alias template, or template template parameter, and // therefore cannot be a non-type template argument. Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr) << Arg.getSourceRange(); Diag(Param->getLocation(), diag::note_template_param_here); return true; case TemplateArgument::Type: { // We have a non-type template parameter but the template // argument is a type. // C++ [temp.arg]p2: // In a template-argument, an ambiguity between a type-id and // an expression is resolved to a type-id, regardless of the // form of the corresponding template-parameter. // // We warn specifically about this case, since it can be rather // confusing for users. QualType T = Arg.getArgument().getAsType(); SourceRange SR = Arg.getSourceRange(); if (T->isFunctionType()) Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T; else Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR; Diag(Param->getLocation(), diag::note_template_param_here); return true; } case TemplateArgument::Pack: llvm_unreachable("Caller must expand template argument packs"); } return false; } // Check template template parameters. TemplateTemplateParmDecl *TempParm = cast
(Param); // Substitute into the template parameter list of the template // template parameter, since previously-supplied template arguments // may appear within the template template parameter. { // Set up a template instantiation context. LocalInstantiationScope Scope(*this); InstantiatingTemplate Inst(*this, TemplateLoc, Template, TempParm, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return true; TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted.data(), Converted.size()); TempParm = cast_or_null
( SubstDecl(TempParm, CurContext, MultiLevelTemplateArgumentList(TemplateArgs))); if (!TempParm) return true; } switch (Arg.getArgument().getKind()) { case TemplateArgument::Null: llvm_unreachable("Should never see a NULL template argument here"); case TemplateArgument::Template: case TemplateArgument::TemplateExpansion: if (CheckTemplateArgument(TempParm, Arg, ArgumentPackIndex)) return true; Converted.push_back(Arg.getArgument()); break; case TemplateArgument::Expression: case TemplateArgument::Type: // We have a template template parameter but the template // argument does not refer to a template. Diag(Arg.getLocation(), diag::err_template_arg_must_be_template) << getLangOpts().CPlusPlus11; return true; case TemplateArgument::Declaration: llvm_unreachable("Declaration argument with template template parameter"); case TemplateArgument::Integral: llvm_unreachable("Integral argument with template template parameter"); case TemplateArgument::NullPtr: llvm_unreachable("Null pointer argument with template template parameter"); case TemplateArgument::Pack: llvm_unreachable("Caller must expand template argument packs"); } return false; } /// \brief Diagnose an arity mismatch in the static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs) { TemplateParameterList *Params = Template->getTemplateParameters(); unsigned NumParams = Params->size(); unsigned NumArgs = TemplateArgs.size(); SourceRange Range; if (NumArgs > NumParams) Range = SourceRange(TemplateArgs[NumParams].getLocation(), TemplateArgs.getRAngleLoc()); S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity) << (NumArgs > NumParams) << (isa
(Template)? 0 : isa
(Template)? 1 : isa
(Template)? 2 : 3) << Template << Range; S.Diag(Template->getLocation(), diag::note_template_decl_here) << Params->getSourceRange(); return true; } /// \brief Check whether the template parameter is a pack expansion, and if so, /// determine the number of parameters produced by that expansion. For instance: /// /// \code /// template
struct A { /// template
class ...TTs, typename ...Us> struct B; /// }; /// \endcode /// /// In \c A
::B, \c NTs and \c TTs have expanded pack size 2, and \c Us /// is not a pack expansion, so returns an empty Optional. static Optional
getExpandedPackSize(NamedDecl *Param) { if (NonTypeTemplateParmDecl *NTTP = dyn_cast
(Param)) { if (NTTP->isExpandedParameterPack()) return NTTP->getNumExpansionTypes(); } if (TemplateTemplateParmDecl *TTP = dyn_cast
(Param)) { if (TTP->isExpandedParameterPack()) return TTP->getNumExpansionTemplateParameters(); } return None; } /// \brief Check that the given template argument list is well-formed /// for specializing the given template. bool Sema::CheckTemplateArgumentList(TemplateDecl *Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs, SmallVectorImpl
&Converted) { TemplateParameterList *Params = Template->getTemplateParameters(); SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc(); // C++ [temp.arg]p1: // [...] The type and form of each template-argument specified in // a template-id shall match the type and form specified for the // corresponding parameter declared by the template in its // template-parameter-list. bool isTemplateTemplateParameter = isa
(Template); SmallVector
ArgumentPack; unsigned ArgIdx = 0, NumArgs = TemplateArgs.size(); LocalInstantiationScope InstScope(*this, true); for (TemplateParameterList::iterator Param = Params->begin(), ParamEnd = Params->end(); Param != ParamEnd; /* increment in loop */) { // If we have an expanded parameter pack, make sure we don't have too // many arguments. if (Optional
Expansions = getExpandedPackSize(*Param)) { if (*Expansions == ArgumentPack.size()) { // We're done with this parameter pack. Pack up its arguments and add // them to the list. Converted.push_back( TemplateArgument::CreatePackCopy(Context, ArgumentPack.data(), ArgumentPack.size())); ArgumentPack.clear(); // This argument is assigned to the next parameter. ++Param; continue; } else if (ArgIdx == NumArgs && !PartialTemplateArgs) { // Not enough arguments for this parameter pack. Diag(TemplateLoc, diag::err_template_arg_list_different_arity) << false << (isa
(Template)? 0 : isa
(Template)? 1 : isa
(Template)? 2 : 3) << Template; Diag(Template->getLocation(), diag::note_template_decl_here) << Params->getSourceRange(); return true; } } if (ArgIdx < NumArgs) { // Check the template argument we were given. if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template, TemplateLoc, RAngleLoc, ArgumentPack.size(), Converted)) return true; if (TemplateArgs[ArgIdx].getArgument().isPackExpansion() && isa
(Template) && !(Param + 1 == ParamEnd && (*Param)->isTemplateParameterPack() && !getExpandedPackSize(*Param))) { // Core issue 1430: we have a pack expansion as an argument to an // alias template, and it's not part of a final parameter pack. This // can't be canonicalized, so reject it now. Diag(TemplateArgs[ArgIdx].getLocation(), diag::err_alias_template_expansion_into_fixed_list) << TemplateArgs[ArgIdx].getSourceRange(); Diag((*Param)->getLocation(), diag::note_template_param_here); return true; } // We're now done with this argument. ++ArgIdx; if ((*Param)->isTemplateParameterPack()) { // The template parameter was a template parameter pack, so take the // deduced argument and place it on the argument pack. Note that we // stay on the same template parameter so that we can deduce more // arguments. ArgumentPack.push_back(Converted.pop_back_val()); } else { // Move to the next template parameter. ++Param; } // If we just saw a pack expansion, then directly convert the remaining // arguments, because we don't know what parameters they'll match up // with. if (TemplateArgs[ArgIdx-1].getArgument().isPackExpansion()) { bool InFinalParameterPack = Param != ParamEnd && Param + 1 == ParamEnd && (*Param)->isTemplateParameterPack() && !getExpandedPackSize(*Param); if (!InFinalParameterPack && !ArgumentPack.empty()) { // If we were part way through filling in an expanded parameter pack, // fall back to just producing individual arguments. Converted.insert(Converted.end(), ArgumentPack.begin(), ArgumentPack.end()); ArgumentPack.clear(); } while (ArgIdx < NumArgs) { if (InFinalParameterPack) ArgumentPack.push_back(TemplateArgs[ArgIdx].getArgument()); else Converted.push_back(TemplateArgs[ArgIdx].getArgument()); ++ArgIdx; } // Push the argument pack onto the list of converted arguments. if (InFinalParameterPack) { Converted.push_back( TemplateArgument::CreatePackCopy(Context, ArgumentPack.data(), ArgumentPack.size())); ArgumentPack.clear(); } return false; } continue; } // If we're checking a partial template argument list, we're done. if (PartialTemplateArgs) { if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty()) Converted.push_back(TemplateArgument::CreatePackCopy(Context, ArgumentPack.data(), ArgumentPack.size())); return false; } // If we have a template parameter pack with no more corresponding // arguments, just break out now and we'll fill in the argument pack below. if ((*Param)->isTemplateParameterPack()) { assert(!getExpandedPackSize(*Param) && "Should have dealt with this already"); // A non-expanded parameter pack before the end of the parameter list // only occurs for an ill-formed template parameter list, unless we've // got a partial argument list for a function template, so just bail out. if (Param + 1 != ParamEnd) return true; Converted.push_back(TemplateArgument::CreatePackCopy(Context, ArgumentPack.data(), ArgumentPack.size())); ArgumentPack.clear(); ++Param; continue; } // Check whether we have a default argument. TemplateArgumentLoc Arg; // Retrieve the default template argument from the template // parameter. For each kind of template parameter, we substitute the // template arguments provided thus far and any "outer" template arguments // (when the template parameter was part of a nested template) into // the default argument. if (TemplateTypeParmDecl *TTP = dyn_cast
(*Param)) { if (!TTP->hasDefaultArgument()) return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs); TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, TTP, Converted); if (!ArgType) return true; Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()), ArgType); } else if (NonTypeTemplateParmDecl *NTTP = dyn_cast
(*Param)) { if (!NTTP->hasDefaultArgument()) return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs); ExprResult E = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, NTTP, Converted); if (E.isInvalid()) return true; Expr *Ex = E.getAs
(); Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex); } else { TemplateTemplateParmDecl *TempParm = cast
(*Param); if (!TempParm->hasDefaultArgument()) return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs); NestedNameSpecifierLoc QualifierLoc; TemplateName Name = SubstDefaultTemplateArgument(*this, Template, TemplateLoc, RAngleLoc, TempParm, Converted, QualifierLoc); if (Name.isNull()) return true; Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc, TempParm->getDefaultArgument().getTemplateNameLoc()); } // Introduce an instantiation record that describes where we are using // the default template argument. InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted, SourceRange(TemplateLoc, RAngleLoc)); if (Inst.isInvalid()) return true; // Check the default template argument. if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc, RAngleLoc, 0, Converted)) return true; // Core issue 150 (assumed resolution): if this is a template template // parameter, keep track of the default template arguments from the // template definition. if (isTemplateTemplateParameter) TemplateArgs.addArgument(Arg); // Move to the next template parameter and argument. ++Param; ++ArgIdx; } // If we're performing a partial argument substitution, allow any trailing // pack expansions; they might be empty. This can happen even if // PartialTemplateArgs is false (the list of arguments is complete but // still dependent). if (ArgIdx < NumArgs && CurrentInstantiationScope && CurrentInstantiationScope->getPartiallySubstitutedPack()) { while (ArgIdx < NumArgs && TemplateArgs[ArgIdx].getArgument().isPackExpansion()) Converted.push_back(TemplateArgs[ArgIdx++].getArgument()); } // If we have any leftover arguments, then there were too many arguments. // Complain and fail. if (ArgIdx < NumArgs) return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs); return false; } namespace { class UnnamedLocalNoLinkageFinder : public TypeVisitor
{ Sema &S; SourceRange SR; typedef TypeVisitor
inherited; public: UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { } bool Visit(QualType T) { return inherited::Visit(T.getTypePtr()); } #define TYPE(Class, Parent) \ bool Visit##Class##Type(const Class##Type *); #define ABSTRACT_TYPE(Class, Parent) \ bool Visit##Class##Type(const Class##Type *) { return false; } #define NON_CANONICAL_TYPE(Class, Parent) \ bool Visit##Class##Type(const Class##Type *) { return false; } #include "clang/AST/TypeNodes.def" bool VisitTagDecl(const TagDecl *Tag); bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS); }; } bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) { return Visit(T->getPointeeType()); } bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType( const BlockPointerType* T) { return Visit(T->getPointeeType()); } bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType( const LValueReferenceType* T) { return Visit(T->getPointeeType()); } bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType( const RValueReferenceType* T) { return Visit(T->getPointeeType()); } bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType( const MemberPointerType* T) { return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0)); } bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType( const ConstantArrayType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType( const IncompleteArrayType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType( const VariableArrayType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType( const DependentSizedArrayType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType( const DependentSizedExtVectorType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) { return Visit(T->getElementType()); } bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType( const FunctionProtoType* T) { for (const auto &A : T->param_types()) { if (Visit(A)) return true; } return Visit(T->getReturnType()); } bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType( const FunctionNoProtoType* T) { return Visit(T->getReturnType()); } bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType( const UnresolvedUsingType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) { return Visit(T->getUnderlyingType()); } bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType( const UnaryTransformType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) { return Visit(T->getDeducedType()); } bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) { return VisitTagDecl(T->getDecl()); } bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) { return VisitTagDecl(T->getDecl()); } bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType( const TemplateTypeParmType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType( const SubstTemplateTypeParmPackType *) { return false; } bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType( const TemplateSpecializationType*) { return false; } bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType( const InjectedClassNameType* T) { return VisitTagDecl(T->getDecl()); } bool UnnamedLocalNoLinkageFinder::VisitDependentNameType( const DependentNameType* T) { return VisitNestedNameSpecifier(T->getQualifier()); } bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType( const DependentTemplateSpecializationType* T) { return VisitNestedNameSpecifier(T->getQualifier()); } bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType( const PackExpansionType* T) { return Visit(T->getPattern()); } bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) { return false; } bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType( const ObjCInterfaceType *) { return false; } bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType( const ObjCObjectPointerType *) { return false; } bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) { return Visit(T->getValueType()); } bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) { if (Tag->getDeclContext()->isFunctionOrMethod()) { S.Diag(SR.getBegin(), S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_arg_local_type : diag::ext_template_arg_local_type) << S.Context.getTypeDeclType(Tag) << SR; return true; } if (!Tag->hasNameForLinkage()) { S.Diag(SR.getBegin(), S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_arg_unnamed_type : diag::ext_template_arg_unnamed_type) << SR; S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here); return true; } return false; } bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier( NestedNameSpecifier *NNS) { if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix())) return true; switch (NNS->getKind()) { case NestedNameSpecifier::Identifier: case NestedNameSpecifier::Namespace: case NestedNameSpecifier::NamespaceAlias: case NestedNameSpecifier::Global: return false; case NestedNameSpecifier::TypeSpec: case NestedNameSpecifier::TypeSpecWithTemplate: return Visit(QualType(NNS->getAsType(), 0)); } llvm_unreachable("Invalid NestedNameSpecifier::Kind!"); } /// \brief Check a template argument against its corresponding /// template type parameter. /// /// This routine implements the semantics of C++ [temp.arg.type]. It /// returns true if an error occurred, and false otherwise. bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param, TypeSourceInfo *ArgInfo) { assert(ArgInfo && "invalid TypeSourceInfo"); QualType Arg = ArgInfo->getType(); SourceRange SR = ArgInfo->getTypeLoc().getSourceRange(); if (Arg->isVariablyModifiedType()) { return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg; } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) { return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR; } // C++03 [temp.arg.type]p2: // A local type, a type with no linkage, an unnamed type or a type // compounded from any of these types shall not be used as a // template-argument for a template type-parameter. // // C++11 allows these, and even in C++03 we allow them as an extension with // a warning. bool NeedsCheck; if (LangOpts.CPlusPlus11) NeedsCheck = !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_unnamed_type, SR.getBegin()) || !Diags.isIgnored(diag::warn_cxx98_compat_template_arg_local_type, SR.getBegin()); else NeedsCheck = Arg->hasUnnamedOrLocalType(); if (NeedsCheck) { UnnamedLocalNoLinkageFinder Finder(*this, SR); (void)Finder.Visit(Context.getCanonicalType(Arg)); } return false; } enum NullPointerValueKind { NPV_NotNullPointer, NPV_NullPointer, NPV_Error }; /// \brief Determine whether the given template argument is a null pointer /// value of the appropriate type. static NullPointerValueKind isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *Arg) { if (Arg->isValueDependent() || Arg->isTypeDependent()) return NPV_NotNullPointer; if (!S.getLangOpts().CPlusPlus11 || S.getLangOpts().MSVCCompat) return NPV_NotNullPointer; // Determine whether we have a constant expression. ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg); if (ArgRV.isInvalid()) return NPV_Error; Arg = ArgRV.get(); Expr::EvalResult EvalResult; SmallVector
Notes; EvalResult.Diag = &Notes; if (!Arg->EvaluateAsRValue(EvalResult, S.Context) || EvalResult.HasSideEffects) { SourceLocation DiagLoc = Arg->getExprLoc(); // If our only note is the usual "invalid subexpression" note, just point // the caret at its location rather than producing an essentially // redundant note. if (Notes.size() == 1 && Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) { DiagLoc = Notes[0].first; Notes.clear(); } S.Diag(DiagLoc, diag::err_template_arg_not_address_constant) << Arg->getType() << Arg->getSourceRange(); for (unsigned I = 0, N = Notes.size(); I != N; ++I) S.Diag(Notes[I].first, Notes[I].second); S.Diag(Param->getLocation(), diag::note_template_param_here); return NPV_Error; } // C++11 [temp.arg.nontype]p1: // - an address constant expression of type std::nullptr_t if (Arg->getType()->isNullPtrType()) return NPV_NullPointer; // - a constant expression that evaluates to a null pointer value (4.10); or // - a constant expression that evaluates to a null member pointer value // (4.11); or if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) || (EvalResult.Val.isMemberPointer() && !EvalResult.Val.getMemberPointerDecl())) { // If our expression has an appropriate type, we've succeeded. bool ObjCLifetimeConversion; if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) || S.IsQualificationConversion(Arg->getType(), ParamType, false, ObjCLifetimeConversion)) return NPV_NullPointer; // The types didn't match, but we know we got a null pointer; complain, // then recover as if the types were correct. S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant) << Arg->getType() << ParamType << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return NPV_NullPointer; } // If we don't have a null pointer value, but we do have a NULL pointer // constant, suggest a cast to the appropriate type. if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) { std::string Code = "static_cast<" + ParamType.getAsString() + ">("; S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant) << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), Code) << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getLocEnd()), ")"); S.Diag(Param->getLocation(), diag::note_template_param_here); return NPV_NullPointer; } // FIXME: If we ever want to support general, address-constant expressions // as non-type template arguments, we should return the ExprResult here to // be interpreted by the caller. return NPV_NotNullPointer; } /// \brief Checks whether the given template argument is compatible with its /// template parameter. static bool CheckTemplateArgumentIsCompatibleWithParameter( Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn, Expr *Arg, QualType ArgType) { bool ObjCLifetimeConversion; if (ParamType->isPointerType() && !ParamType->getAs
()->getPointeeType()->isFunctionType() && S.IsQualificationConversion(ArgType, ParamType, false, ObjCLifetimeConversion)) { // For pointer-to-object types, qualification conversions are // permitted. } else { if (const ReferenceType *ParamRef = ParamType->getAs
()) { if (!ParamRef->getPointeeType()->isFunctionType()) { // C++ [temp.arg.nontype]p5b3: // For a non-type template-parameter of type reference to // object, no conversions apply. The type referred to by the // reference may be more cv-qualified than the (otherwise // identical) type of the template- argument. The // template-parameter is bound directly to the // template-argument, which shall be an lvalue. // FIXME: Other qualifiers? unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers(); unsigned ArgQuals = ArgType.getCVRQualifiers(); if ((ParamQuals | ArgQuals) != ParamQuals) { S.Diag(Arg->getLocStart(), diag::err_template_arg_ref_bind_ignores_quals) << ParamType << Arg->getType() << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } } } // At this point, the template argument refers to an object or // function with external linkage. We now need to check whether the // argument and parameter types are compatible. if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType.getNonReferenceType())) { // We can't perform this conversion or binding. if (ParamType->isReferenceType()) S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind) << ParamType << ArgIn->getType() << Arg->getSourceRange(); else S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) << ArgIn->getType() << ParamType << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } } return false; } /// \brief Checks whether the given template argument is the address /// of an object or function according to C++ [temp.arg.nontype]p1. static bool CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn, TemplateArgument &Converted) { bool Invalid = false; Expr *Arg = ArgIn; QualType ArgType = Arg->getType(); bool AddressTaken = false; SourceLocation AddrOpLoc; if (S.getLangOpts().MicrosoftExt) { // Microsoft Visual C++ strips all casts, allows an arbitrary number of // dereference and address-of operators. Arg = Arg->IgnoreParenCasts(); bool ExtWarnMSTemplateArg = false; UnaryOperatorKind FirstOpKind; SourceLocation FirstOpLoc; while (UnaryOperator *UnOp = dyn_cast
(Arg)) { UnaryOperatorKind UnOpKind = UnOp->getOpcode(); if (UnOpKind == UO_Deref) ExtWarnMSTemplateArg = true; if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) { Arg = UnOp->getSubExpr()->IgnoreParenCasts(); if (!AddrOpLoc.isValid()) { FirstOpKind = UnOpKind; FirstOpLoc = UnOp->getOperatorLoc(); } } else break; } if (FirstOpLoc.isValid()) { if (ExtWarnMSTemplateArg) S.Diag(ArgIn->getLocStart(), diag::ext_ms_deref_template_argument) << ArgIn->getSourceRange(); if (FirstOpKind == UO_AddrOf) AddressTaken = true; else if (Arg->getType()->isPointerType()) { // We cannot let pointers get dereferenced here, that is obviously not a // constant expression. assert(FirstOpKind == UO_Deref); S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) << Arg->getSourceRange(); } } } else { // See through any implicit casts we added to fix the type. Arg = Arg->IgnoreImpCasts(); // C++ [temp.arg.nontype]p1: // // A template-argument for a non-type, non-template // template-parameter shall be one of: [...] // // -- the address of an object or function with external // linkage, including function templates and function // template-ids but excluding non-static class members, // expressed as & id-expression where the & is optional if // the name refers to a function or array, or if the // corresponding template-parameter is a reference; or // In C++98/03 mode, give an extension warning on any extra parentheses. // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 bool ExtraParens = false; while (ParenExpr *Parens = dyn_cast
(Arg)) { if (!Invalid && !ExtraParens) { S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_arg_extra_parens : diag::ext_template_arg_extra_parens) << Arg->getSourceRange(); ExtraParens = true; } Arg = Parens->getSubExpr(); } while (SubstNonTypeTemplateParmExpr *subst = dyn_cast
(Arg)) Arg = subst->getReplacement()->IgnoreImpCasts(); if (UnaryOperator *UnOp = dyn_cast
(Arg)) { if (UnOp->getOpcode() == UO_AddrOf) { Arg = UnOp->getSubExpr(); AddressTaken = true; AddrOpLoc = UnOp->getOperatorLoc(); } } while (SubstNonTypeTemplateParmExpr *subst = dyn_cast
(Arg)) Arg = subst->getReplacement()->IgnoreImpCasts(); } DeclRefExpr *DRE = dyn_cast
(Arg); ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr; // If our parameter has pointer type, check for a null template value. if (ParamType->isPointerType() || ParamType->isNullPtrType()) { NullPointerValueKind NPV; // dllimport'd entities aren't constant but are available inside of template // arguments. if (Entity && Entity->hasAttr
()) NPV = NPV_NotNullPointer; else NPV = isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn); switch (NPV) { case NPV_NullPointer: S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); Converted = TemplateArgument(ParamType, /*isNullPtr=*/true); return false; case NPV_Error: return true; case NPV_NotNullPointer: break; } } // Stop checking the precise nature of the argument if it is value dependent, // it should be checked when instantiated. if (Arg->isValueDependent()) { Converted = TemplateArgument(ArgIn); return false; } if (isa
(Arg)) { if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn, Arg, ArgType)) return true; Converted = TemplateArgument(ArgIn); return false; } if (!DRE) { S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref) << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } // Cannot refer to non-static data members if (isa
(Entity) || isa
(Entity)) { S.Diag(Arg->getLocStart(), diag::err_template_arg_field) << Entity << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } // Cannot refer to non-static member functions if (CXXMethodDecl *Method = dyn_cast
(Entity)) { if (!Method->isStatic()) { S.Diag(Arg->getLocStart(), diag::err_template_arg_method) << Method << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } } FunctionDecl *Func = dyn_cast
(Entity); VarDecl *Var = dyn_cast
(Entity); // A non-type template argument must refer to an object or function. if (!Func && !Var) { // We found something, but we don't know specifically what it is. S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func) << Arg->getSourceRange(); S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); return true; } // Address / reference template args must have external linkage in C++98. if (Entity->getFormalLinkage() == InternalLinkage) { S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_arg_object_internal : diag::ext_template_arg_object_internal) << !Func << Entity << Arg->getSourceRange(); S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object) << !Func; } else if (!Entity->hasLinkage()) { S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage) << !Func << Entity << Arg->getSourceRange(); S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object) << !Func; return true; } if (Func) { // If the template parameter has pointer type, the function decays. if (ParamType->isPointerType() && !AddressTaken) ArgType = S.Context.getPointerType(Func->getType()); else if (AddressTaken && ParamType->isReferenceType()) { // If we originally had an address-of operator, but the // parameter has reference type, complain and (if things look // like they will work) drop the address-of operator. if (!S.Context.hasSameUnqualifiedType(Func->getType(), ParamType.getNonReferenceType())) { S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) << ParamType; S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) << ParamType << FixItHint::CreateRemoval(AddrOpLoc); S.Diag(Param->getLocation(), diag::note_template_param_here); ArgType = Func->getType(); } } else { // A value of reference type is not an object. if (Var->getType()->isReferenceType()) { S.Diag(Arg->getLocStart(), diag::err_template_arg_reference_var) << Var->getType() << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } // A template argument must have static storage duration. if (Var->getTLSKind()) { S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local) << Arg->getSourceRange(); S.Diag(Var->getLocation(), diag::note_template_arg_refers_here); return true; } // If the template parameter has pointer type, we must have taken // the address of this object. if (ParamType->isReferenceType()) { if (AddressTaken) { // If we originally had an address-of operator, but the // parameter has reference type, complain and (if things look // like they will work) drop the address-of operator. if (!S.Context.hasSameUnqualifiedType(Var->getType(), ParamType.getNonReferenceType())) { S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) << ParamType; S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer) << ParamType << FixItHint::CreateRemoval(AddrOpLoc); S.Diag(Param->getLocation(), diag::note_template_param_here); ArgType = Var->getType(); } } else if (!AddressTaken && ParamType->isPointerType()) { if (Var->getType()->isArrayType()) { // Array-to-pointer decay. ArgType = S.Context.getArrayDecayedType(Var->getType()); } else { // If the template parameter has pointer type but the address of // this object was not taken, complain and (possibly) recover by // taking the address of the entity. ArgType = S.Context.getPointerType(Var->getType()); if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) { S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) << ParamType; S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of) << ParamType << FixItHint::CreateInsertion(Arg->getLocStart(), "&"); S.Diag(Param->getLocation(), diag::note_template_param_here); } } } if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn, Arg, ArgType)) return true; // Create the template argument. Converted = TemplateArgument(cast
(Entity->getCanonicalDecl()), ParamType->isReferenceType()); S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity, false); return false; } /// \brief Checks whether the given template argument is a pointer to /// member constant according to C++ [temp.arg.nontype]p1. static bool CheckTemplateArgumentPointerToMember(Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *&ResultArg, TemplateArgument &Converted) { bool Invalid = false; // Check for a null pointer value. Expr *Arg = ResultArg; switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) { case NPV_Error: return true; case NPV_NullPointer: S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); Converted = TemplateArgument(ParamType, /*isNullPtr*/true); if (S.Context.getTargetInfo().getCXXABI().isMicrosoft()) S.RequireCompleteType(Arg->getExprLoc(), ParamType, 0); return false; case NPV_NotNullPointer: break; } bool ObjCLifetimeConversion; if (S.IsQualificationConversion(Arg->getType(), ParamType.getNonReferenceType(), false, ObjCLifetimeConversion)) { Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp, Arg->getValueKind()).get(); ResultArg = Arg; } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType.getNonReferenceType())) { // We can't perform this conversion. S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) << Arg->getType() << ParamType << Arg->getSourceRange(); S.Diag(Param->getLocation(), diag::note_template_param_here); return true; } // See through any implicit casts we added to fix the type. while (ImplicitCastExpr *Cast = dyn_cast
(Arg)) Arg = Cast->getSubExpr(); // C++ [temp.arg.nontype]p1: // // A template-argument for a non-type, non-template // template-parameter shall be one of: [...] // // -- a pointer to member expressed as described in 5.3.1. DeclRefExpr *DRE = nullptr; // In C++98/03 mode, give an extension warning on any extra parentheses. // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773 bool ExtraParens = false; while (ParenExpr *Parens = dyn_cast
(Arg)) { if (!Invalid && !ExtraParens) { S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus11 ? diag::warn_cxx98_compat_template_arg_extra_parens : diag::ext_template_arg_extra_parens) << Arg->getSourceRange(); ExtraParens = true; } Arg = Parens->getSubExpr(); } while (SubstNonTypeTemplateParmExpr *subst = dyn_cast
(Arg)) Arg = subst->getReplacement()->IgnoreImpCasts(); // A pointer-to-member constant written &Class::member. if (UnaryOperator *UnOp = dyn_cast
(Arg)) { if (UnOp->getOpcode() == UO_AddrOf) { DRE = dyn_cast
(UnOp->getSubExpr()); if (DRE && !DRE->getQualifier()) DRE = nullptr; } } // A constant of pointer-to-member type. else if ((DRE = dyn_cast
(Arg))) { if (ValueDecl *VD = dyn_cast
(DRE->getDecl())) { if (VD->getType()->isMemberPointerType()) { if (isa
(VD)) { if (Arg->isTypeDependent() || Arg->isValueDependent()) { Converted = TemplateArgument(Arg); } else { VD = cast
(VD->getCanonicalDecl()); Converted = TemplateArgument(VD, /*isReferenceParam*/false); } return Invalid; } } } DRE = nullptr; } if (!DRE) return S.Diag(Arg->getLocStart(), diag::err_template_arg_not_pointer_to_member_form) << Arg->getSourceRange(); if (isa
(DRE->getDecl()) || isa
(DRE->getDecl()) || isa
(DRE->getDecl())) { assert((isa
(DRE->getDecl()) || isa
(DRE->getDecl()) || !cast
(DRE->getDecl())->isStatic()) && "Only non-static member pointers can make it here"); // Okay: this is the address of a non-static member, and therefore // a member pointer constant. if (Arg->isTypeDependent() || Arg->isValueDependent()) { Converted = TemplateArgument(Arg); } else { ValueDecl *D = cast
(DRE->getDecl()->getCanonicalDecl()); Converted = TemplateArgument(D, /*isReferenceParam*/false); } return Invalid; } // We found something else, but we don't know specifically what it is. S.Diag(Arg->getLocStart(), diag::err_template_arg_not_pointer_to_member_form) << Arg->getSourceRange(); S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here); return true; } /// \brief Check a template argument against its corresponding /// non-type template parameter. /// /// This routine implements the semantics of C++ [temp.arg.nontype]. /// If an error occurred, it returns ExprError(); otherwise, it /// returns the converted template argument. \p /// InstantiatedParamType is the type of the non-type template /// parameter after it has been instantiated. ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param, QualType InstantiatedParamType, Expr *Arg, TemplateArgument &Converted, CheckTemplateArgumentKind CTAK) { SourceLocation StartLoc = Arg->getLocStart(); // If either the parameter has a dependent type or the argument is // type-dependent, there's nothing we can check now. if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) { // FIXME: Produce a cloned, canonical expression? Converted = TemplateArgument(Arg); return Arg; } // C++ [temp.arg.nontype]p5: // The following conversions are performed on each expression used // as a non-type template-argument. If a non-type // template-argument cannot be converted to the type of the // corresponding template-parameter then the program is // ill-formed. QualType ParamType = InstantiatedParamType; if (ParamType->isIntegralOrEnumerationType()) { // C++11: // -- for a non-type template-parameter of integral or // enumeration type, conversions permitted in a converted // constant expression are applied. // // C++98: // -- for a non-type template-parameter of integral or // enumeration type, integral promotions (4.5) and integral // conversions (4.7) are applied. if (CTAK == CTAK_Deduced && !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) { // C++ [temp.deduct.type]p17: // If, in the declaration of a function template with a non-type // template-parameter, the non-type template-parameter is used // in an expression in the function parameter-list and, if the // corresponding template-argument is deduced, the // template-argument type shall match the type of the // template-parameter exactly, except that a template-argument // deduced from an array bound may be of any integral type. Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch) << Arg->getType().getUnqualifiedType() << ParamType.getUnqualifiedType(); Diag(Param->getLocation(), diag::note_template_param_here); return ExprError(); } if (getLangOpts().CPlusPlus11) { // We can't check arbitrary value-dependent arguments. // FIXME: If there's no viable conversion to the template parameter type, // we should be able to diagnose that prior to instantiation. if (Arg->isValueDependent()) { Converted = TemplateArgument(Arg); return Arg; } // C++ [temp.arg.nontype]p1: // A template-argument for a non-type, non-template template-parameter // shall be one of: // // -- for a non-type template-parameter of integral or enumeration // type, a converted constant expression of the type of the // template-parameter; or llvm::APSInt Value; ExprResult ArgResult = CheckConvertedConstantExpression(Arg, ParamType, Value, CCEK_TemplateArg); if (ArgResult.isInvalid()) return ExprError(); // Widen the argument value to sizeof(parameter type). This is almost // always a no-op, except when the parameter type is bool. In // that case, this may extend the argument from 1 bit to 8 bits. QualType IntegerType = ParamType; if (const EnumType *Enum = IntegerType->getAs
()) IntegerType = Enum->getDecl()->getIntegerType(); Value = Value.extOrTrunc(Context.getTypeSize(IntegerType)); Converted = TemplateArgument(Context, Value, Context.getCanonicalType(ParamType)); return ArgResult; } ExprResult ArgResult = DefaultLvalueConversion(Arg); if (ArgResult.isInvalid()) return ExprError(); Arg = ArgResult.get(); QualType ArgType = Arg->getType(); // C++ [temp.arg.nontype]p1: // A template-argument for a non-type, non-template // template-parameter shall be one of: // // -- an integral constant-expression of integral or enumeration // type; or // -- the name of a non-type template-parameter; or SourceLocation NonConstantLoc; llvm::APSInt Value; if (!ArgType->isIntegralOrEnumerationType()) { Diag(Arg->getLocStart(), diag::err_template_arg_not_integral_or_enumeral) << ArgType << Arg->getSourceRange(); Diag(Param->getLocation(), diag::note_template_param_here); return ExprError(); } else if (!Arg->isValueDependent()) { class TmplArgICEDiagnoser : public VerifyICEDiagnoser { QualType T; public: TmplArgICEDiagnoser(QualType T) : T(T) { } void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override { S.Diag(Loc, diag::err_template_arg_not_ice) << T << SR; } } Diagnoser(ArgType); Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser, false).get(); if (!Arg) return ExprError(); } // From here on out, all we care about are the unqualified forms // of the parameter and argument types. ParamType = ParamType.getUnqualifiedType(); ArgType = ArgType.getUnqualifiedType(); // Try to convert the argument to the parameter's type. if (Context.hasSameType(ParamType, ArgType)) { // Okay: no conversion necessary } else if (ParamType->isBooleanType()) { // This is an integral-to-boolean conversion. Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get(); } else if (IsIntegralPromotion(Arg, ArgType, ParamType) || !ParamType->isEnumeralType()) { // This is an integral promotion or conversion. Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get(); } else { // We can't perform this conversion. Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible) << Arg->getType() << InstantiatedParamType << Arg->getSourceRange(); Diag(Param->getLocation(), diag::note_template_param_here); return ExprError(); } // Add the value of this argument to the list of converted // arguments. We use the bitwidth and signedness of the template // parameter. if (Arg->isValueDependent()) { // The argument is value-dependent. Create a new // TemplateArgument with the converted expression. Converted = TemplateArgument(Arg); return Arg; } QualType IntegerType = Context.getCanonicalType(ParamType); if (const EnumType *Enum = IntegerType->getAs
()) IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType()); if (ParamType->isBooleanType()) { // Value must be zero or one. Value = Value != 0; unsigned AllowedBits = Context.getTypeSize(IntegerType); if (Value.getBitWidth() != AllowedBits) Value = Value.extOrTrunc(AllowedBits); Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType()); } else { llvm::APSInt OldValue = Value; // Coerce the template argument's value to the value it will have // based on the template parameter's type. unsigned AllowedBits = Context.getTypeSize(IntegerType); if (Value.getBitWidth() != AllowedBits) Value = Value.extOrTrunc(AllowedBits); Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType()); // Complain if an unsigned parameter received a negative value. if (IntegerType->isUnsignedIntegerOrEnumerationType() && (OldValue.isSigned() && OldValue.isNegative())) { Diag(Arg->getLocStart(), diag::warn_template_arg_negative) << OldValue.toString(10) << Value.toString(10) << Param->getType() << Arg->getSourceRange(); Diag(Param->getLocation(), diag::note_template_param_here); } // Complain if we overflowed the template parameter's type. unsigned RequiredBits; if (IntegerType->isUnsignedIntegerOrEnumerationType()) RequiredBits = OldValue.getActiveBits(); else if (OldValue.isUnsigned()) RequiredBits = OldValue.getActiveBits() + 1; else RequiredBits = OldValue.getMinSignedBits(); if (RequiredBits > AllowedBits) { Diag(Arg->getLocStart(), diag::warn_template_arg_too_large) << OldValue.toString(10) << Value.toString(10) << Param->getType() << Arg->getSourceRange(); Diag(Param->getLocation(), diag::note_template_param_here); } } Converted = TemplateArgument(Context, Value, ParamType->isEnumeralType() ? Context.getCanonicalType(ParamType) : IntegerType); return Arg; } QualType ArgType = Arg->getType(); DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction // Handle pointer-to-function, reference-to-function, and // pointer-to-member-function all in (roughly) the same way. if (// -- For a non-type template-parameter of type pointer to // function, only the function-to-pointer conversion (4.3) is // applied. If the template-argument represents a set of // overloaded functions (or a pointer to such), the matching // function is selected from the set (13.4). (ParamType->isPointerType() && ParamType->getAs
()->getPointeeType()->isFunctionType()) || // -- For a non-type template-parameter of type reference to // function, no conversions apply. If the template-argument // represents a set of overloaded functions, the matching // function is selected from the set (13.4). (ParamType->isReferenceType() && ParamType->getAs
()->getPointeeType()->isFunctionType()) || // -- For a non-type template-parameter of type pointer to // member function, no conversions apply. If the // template-argument represents a set of overloaded member // functions, the matching member function is selected from // the set (13.4). (ParamType->isMemberPointerType() && ParamType->getAs
()->getPointeeType() ->isFunctionType())) { if (Arg->getType() == Context.OverloadTy) { if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType, true, FoundResult)) { if (DiagnoseUseOfDecl(Fn, Arg->getLocStart())) return ExprError(); Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); ArgType = Arg->getType(); } else return ExprError(); } if (!ParamType->isMemberPointerType()) { if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, ParamType, Arg, Converted)) return ExprError(); return Arg; } if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg, Converted)) return ExprError(); return Arg; } if (ParamType->isPointerType()) { // -- for a non-type template-parameter of type pointer to // object, qualification conversions (4.4) and the // array-to-pointer conversion (4.2) are applied. // C++0x also allows a value of std::nullptr_t. assert(ParamType->getPointeeType()->isIncompleteOrObjectType() && "Only object pointers allowed here"); if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, ParamType, Arg, Converted)) return ExprError(); return Arg; } if (const ReferenceType *ParamRefType = ParamType->getAs
()) { // -- For a non-type template-parameter of type reference to // object, no conversions apply. The type referred to by the // reference may be more cv-qualified than the (otherwise // identical) type of the template-argument. The // template-parameter is bound directly to the // template-argument, which must be an lvalue. assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() && "Only object references allowed here"); if (Arg->getType() == Context.OverloadTy) { if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamRefType->getPointeeType(), true, FoundResult)) { if (DiagnoseUseOfDecl(Fn, Arg->getLocStart())) return ExprError(); Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn); ArgType = Arg->getType(); } else return ExprError(); } if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param, ParamType, Arg, Converted)) return ExprError(); return Arg; } // Deal with parameters of type std::nullptr_t. if (ParamType->isNullPtrType()) { if (Arg->isTypeDependent() || Arg->isValueDependent()) { Converted = TemplateArgument(Arg); return Arg; } switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) { case NPV_NotNullPointer: Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible) << Arg->getType() << ParamType; Diag(Param->getLocation(), diag::note_template_param_here); return ExprError(); case NPV_Error: return ExprError(); case NPV_NullPointer: Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null); Converted = TemplateArgument(ParamType, /*isNullPtr*/true); return Arg; } } // -- For a non-type template-parameter of type pointer to data // member, qualification conversions (4.4) are applied. assert(ParamType->isMemberPointerType() && "Only pointers to members remain"); if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg, Converted)) return ExprError(); return Arg; } /// \brief Check a template argument against its corresponding /// template template parameter. /// /// This routine implements the semantics of C++ [temp.arg.template]. /// It returns true if an error occurred, and false otherwise. bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param, TemplateArgumentLoc &Arg, unsigned ArgumentPackIndex) { TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern(); TemplateDecl *Template = Name.getAsTemplateDecl(); if (!Template) { // Any dependent template name is fine. assert(Name.isDependent() && "Non-dependent template isn't a declaration?"); return false; } // C++0x [temp.arg.template]p1: // A template-argument for a template template-parameter shall be // the name of a class template or an alias template, expressed as an // id-expression. When the template-argument names a class template, only // primary class templates are considered when matching the // template template argument with the corresponding parameter; // partial specializations are not considered even if their // parameter lists match that of the template template parameter. // // Note that we also allow template template parameters here, which // will happen when we are dealing with, e.g., class template // partial specializations. if (!isa
(Template) && !isa
(Template) && !isa
(Template)) { assert(isa
(Template) && "Only function templates are possible here"); Diag(Arg.getLocation(), diag::err_template_arg_not_class_template); Diag(Template->getLocation(), diag::note_template_arg_refers_here_func) << Template; } TemplateParameterList *Params = Param->getTemplateParameters(); if (Param->isExpandedParameterPack()) Params = Param->getExpansionTemplateParameters(ArgumentPackIndex); return !TemplateParameterListsAreEqual(Template->getTemplateParameters(), Params, true, TPL_TemplateTemplateArgumentMatch, Arg.getLocation()); } /// \brief Given a non-type template argument that refers to a /// declaration and the type of its corresponding non-type template /// parameter, produce an expression that properly refers to that /// declaration. ExprResult Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg, QualType ParamType, SourceLocation Loc) { // C++ [temp.param]p8: // // A non-type template-parameter of type "array of T" or // "function returning T" is adjusted to be of type "pointer to // T" or "pointer to function returning T", respectively. if (ParamType->isArrayType()) ParamType = Context.getArrayDecayedType(ParamType); else if (ParamType->isFunctionType()) ParamType = Context.getPointerType(ParamType); // For a NULL non-type template argument, return nullptr casted to the // parameter's type. if (Arg.getKind() == TemplateArgument::NullPtr) { return ImpCastExprToType( new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc), ParamType, ParamType->getAs
() ? CK_NullToMemberPointer : CK_NullToPointer); } assert(Arg.getKind() == TemplateArgument::Declaration && "Only declaration template arguments permitted here"); ValueDecl *VD = cast
(Arg.getAsDecl()); if (VD->getDeclContext()->isRecord() && (isa
(VD) || isa
(VD) || isa
(VD))) { // If the value is a class member, we might have a pointer-to-member. // Determine whether the non-type template template parameter is of // pointer-to-member type. If so, we need to build an appropriate // expression for a pointer-to-member, since a "normal" DeclRefExpr // would refer to the member itself. if (ParamType->isMemberPointerType()) { QualType ClassType = Context.getTypeDeclType(cast
(VD->getDeclContext())); NestedNameSpecifier *Qualifier = NestedNameSpecifier::Create(Context, nullptr, false, ClassType.getTypePtr()); CXXScopeSpec SS; SS.MakeTrivial(Context, Qualifier, Loc); // The actual value-ness of this is unimportant, but for // internal consistency's sake, references to instance methods // are r-values. ExprValueKind VK = VK_LValue; if (isa
(VD) && cast
(VD)->isInstance()) VK = VK_RValue; ExprResult RefExpr = BuildDeclRefExpr(VD, VD->getType().getNonReferenceType(), VK, Loc, &SS); if (RefExpr.isInvalid()) return ExprError(); RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); // We might need to perform a trailing qualification conversion, since // the element type on the parameter could be more qualified than the // element type in the expression we constructed. bool ObjCLifetimeConversion; if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(), ParamType.getUnqualifiedType(), false, ObjCLifetimeConversion)) RefExpr = ImpCastExprToType(RefExpr.get(), ParamType.getUnqualifiedType(), CK_NoOp); assert(!RefExpr.isInvalid() && Context.hasSameType(((Expr*) RefExpr.get())->getType(), ParamType.getUnqualifiedType())); return RefExpr; } } QualType T = VD->getType().getNonReferenceType(); if (ParamType->isPointerType()) { // When the non-type template parameter is a pointer, take the // address of the declaration. ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc); if (RefExpr.isInvalid()) return ExprError(); if (T->isFunctionType() || T->isArrayType()) { // Decay functions and arrays. RefExpr = DefaultFunctionArrayConversion(RefExpr.get()); if (RefExpr.isInvalid()) return ExprError(); return RefExpr; } // Take the address of everything else return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get()); } ExprValueKind VK = VK_RValue; // If the non-type template parameter has reference type, qualify the // resulting declaration reference with the extra qualifiers on the // type that the reference refers to. if (const ReferenceType *TargetRef = ParamType->getAs
()) { VK = VK_LValue; T = Context.getQualifiedType(T, TargetRef->getPointeeType().getQualifiers()); } else if (isa
(VD)) { // References to functions are always lvalues. VK = VK_LValue; } return BuildDeclRefExpr(VD, T, VK, Loc); } /// \brief Construct a new expression that refers to the given /// integral template argument with the given source-location /// information. /// /// This routine takes care of the mapping from an integral template /// argument (which may have any integral type) to the appropriate /// literal value. ExprResult Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg, SourceLocation Loc) { assert(Arg.getKind() == TemplateArgument::Integral && "Operation is only valid for integral template arguments"); QualType OrigT = Arg.getIntegralType(); // If this is an enum type that we're instantiating, we need to use an integer // type the same size as the enumerator. We don't want to build an // IntegerLiteral with enum type. The integer type of an enum type can be of // any integral type with C++11 enum classes, make sure we create the right // type of literal for it. QualType T = OrigT; if (const EnumType *ET = OrigT->getAs
()) T = ET->getDecl()->getIntegerType(); Expr *E; if (T->isAnyCharacterType()) { CharacterLiteral::CharacterKind Kind; if (T->isWideCharType()) Kind = CharacterLiteral::Wide; else if (T->isChar16Type()) Kind = CharacterLiteral::UTF16; else if (T->isChar32Type()) Kind = CharacterLiteral::UTF32; else Kind = CharacterLiteral::Ascii; E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(), Kind, T, Loc); } else if (T->isBooleanType()) { E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(), T, Loc); } else if (T->isNullPtrType()) { E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc); } else { E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc); } if (OrigT->isEnumeralType()) { // FIXME: This is a hack. We need a better way to handle substituted // non-type template parameters. E = CStyleCastExpr::Create(Context, OrigT, VK_RValue, CK_IntegralCast, E, nullptr, Context.getTrivialTypeSourceInfo(OrigT, Loc), Loc, Loc); } return E; } /// \brief Match two template parameters within template parameter lists. static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old, bool Complain, Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc) { // Check the actual kind (type, non-type, template). if (Old->getKind() != New->getKind()) { if (Complain) { unsigned NextDiag = diag::err_template_param_different_kind; if (TemplateArgLoc.isValid()) { S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); NextDiag = diag::note_template_param_different_kind; } S.Diag(New->getLocation(), NextDiag) << (Kind != Sema::TPL_TemplateMatch); S.Diag(Old->getLocation(), diag::note_template_prev_declaration) << (Kind != Sema::TPL_TemplateMatch); } return false; } // Check that both are parameter packs are neither are parameter packs. // However, if we are matching a template template argument to a // template template parameter, the template template parameter can have // a parameter pack where the template template argument does not. if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() && !(Kind == Sema::TPL_TemplateTemplateArgumentMatch && Old->isTemplateParameterPack())) { if (Complain) { unsigned NextDiag = diag::err_template_parameter_pack_non_pack; if (TemplateArgLoc.isValid()) { S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); NextDiag = diag::note_template_parameter_pack_non_pack; } unsigned ParamKind = isa
(New)? 0 : isa
(New)? 1 : 2; S.Diag(New->getLocation(), NextDiag) << ParamKind << New->isParameterPack(); S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here) << ParamKind << Old->isParameterPack(); } return false; } // For non-type template parameters, check the type of the parameter. if (NonTypeTemplateParmDecl *OldNTTP = dyn_cast
(Old)) { NonTypeTemplateParmDecl *NewNTTP = cast
(New); // If we are matching a template template argument to a template // template parameter and one of the non-type template parameter types // is dependent, then we must wait until template instantiation time // to actually compare the arguments. if (Kind == Sema::TPL_TemplateTemplateArgumentMatch && (OldNTTP->getType()->isDependentType() || NewNTTP->getType()->isDependentType())) return true; if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) { if (Complain) { unsigned NextDiag = diag::err_template_nontype_parm_different_type; if (TemplateArgLoc.isValid()) { S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); NextDiag = diag::note_template_nontype_parm_different_type; } S.Diag(NewNTTP->getLocation(), NextDiag) << NewNTTP->getType() << (Kind != Sema::TPL_TemplateMatch); S.Diag(OldNTTP->getLocation(), diag::note_template_nontype_parm_prev_declaration) << OldNTTP->getType(); } return false; } return true; } // For template template parameters, check the template parameter types. // The template parameter lists of template template // parameters must agree. if (TemplateTemplateParmDecl *OldTTP = dyn_cast
(Old)) { TemplateTemplateParmDecl *NewTTP = cast
(New); return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(), OldTTP->getTemplateParameters(), Complain, (Kind == Sema::TPL_TemplateMatch ? Sema::TPL_TemplateTemplateParmMatch : Kind), TemplateArgLoc); } return true; } /// \brief Diagnose a known arity mismatch when comparing template argument /// lists. static void DiagnoseTemplateParameterListArityMismatch(Sema &S, TemplateParameterList *New, TemplateParameterList *Old, Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc) { unsigned NextDiag = diag::err_template_param_list_different_arity; if (TemplateArgLoc.isValid()) { S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch); NextDiag = diag::note_template_param_list_different_arity; } S.Diag(New->getTemplateLoc(), NextDiag) << (New->size() > Old->size()) << (Kind != Sema::TPL_TemplateMatch) << SourceRange(New->getTemplateLoc(), New->getRAngleLoc()); S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration) << (Kind != Sema::TPL_TemplateMatch) << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc()); } /// \brief Determine whether the given template parameter lists are /// equivalent. /// /// \param New The new template parameter list, typically written in the /// source code as part of a new template declaration. /// /// \param Old The old template parameter list, typically found via /// name lookup of the template declared with this template parameter /// list. /// /// \param Complain If true, this routine will produce a diagnostic if /// the template parameter lists are not equivalent. /// /// \param Kind describes how we are to match the template parameter lists. /// /// \param TemplateArgLoc If this source location is valid, then we /// are actually checking the template parameter list of a template /// argument (New) against the template parameter list of its /// corresponding template template parameter (Old). We produce /// slightly different diagnostics in this scenario. /// /// \returns True if the template parameter lists are equal, false /// otherwise. bool Sema::TemplateParameterListsAreEqual(TemplateParameterList *New, TemplateParameterList *Old, bool Complain, TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc) { if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) { if (Complain) DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, TemplateArgLoc); return false; } // C++0x [temp.arg.template]p3: // A template-argument matches a template template-parameter (call it P) // when each of the template parameters in the template-parameter-list of // the template-argument's corresponding class template or alias template // (call it A) matches the corresponding template parameter in the // template-parameter-list of P. [...] TemplateParameterList::iterator NewParm = New->begin(); TemplateParameterList::iterator NewParmEnd = New->end(); for (TemplateParameterList::iterator OldParm = Old->begin(), OldParmEnd = Old->end(); OldParm != OldParmEnd; ++OldParm) { if (Kind != TPL_TemplateTemplateArgumentMatch || !(*OldParm)->isTemplateParameterPack()) { if (NewParm == NewParmEnd) { if (Complain) DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, TemplateArgLoc); return false; } if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, Kind, TemplateArgLoc)) return false; ++NewParm; continue; } // C++0x [temp.arg.template]p3: // [...] When P's template- parameter-list contains a template parameter // pack (14.5.3), the template parameter pack will match zero or more // template parameters or template parameter packs in the // template-parameter-list of A with the same type and form as the // template parameter pack in P (ignoring whether those template // parameters are template parameter packs). for (; NewParm != NewParmEnd; ++NewParm) { if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain, Kind, TemplateArgLoc)) return false; } } // Make sure we exhausted all of the arguments. if (NewParm != NewParmEnd) { if (Complain) DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind, TemplateArgLoc); return false; } return true; } /// \brief Check whether a template can be declared within this scope. /// /// If the template declaration is valid in this scope, returns /// false. Otherwise, issues a diagnostic and returns true. bool Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) { if (!S) return false; // Find the nearest enclosing declaration scope. while ((S->getFlags() & Scope::DeclScope) == 0 || (S->getFlags() & Scope::TemplateParamScope) != 0) S = S->getParent(); // C++ [temp]p4: // A template [...] shall not have C linkage. DeclContext *Ctx = S->getEntity(); if (Ctx && Ctx->isExternCContext()) return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage) << TemplateParams->getSourceRange(); while (Ctx && isa
(Ctx)) Ctx = Ctx->getParent(); // C++ [temp]p2: // A template-declaration can appear only as a namespace scope or // class scope declaration. if (Ctx) { if (Ctx->isFileContext()) return false; if (CXXRecordDecl *RD = dyn_cast
(Ctx)) { // C++ [temp.mem]p2: // A local class shall not have member templates. if (RD->isLocalClass()) return Diag(TemplateParams->getTemplateLoc(), diag::err_template_inside_local_class) << TemplateParams->getSourceRange(); else return false; } } return Diag(TemplateParams->getTemplateLoc(), diag::err_template_outside_namespace_or_class_scope) << TemplateParams->getSourceRange(); } /// \brief Determine what kind of template specialization the given declaration /// is. static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) { if (!D) return TSK_Undeclared; if (CXXRecordDecl *Record = dyn_cast
(D)) return Record->getTemplateSpecializationKind(); if (FunctionDecl *Function = dyn_cast
(D)) return Function->getTemplateSpecializationKind(); if (VarDecl *Var = dyn_cast
(D)) return Var->getTemplateSpecializationKind(); return TSK_Undeclared; } /// \brief Check whether a specialization is well-formed in the current /// context. /// /// This routine determines whether a template specialization can be declared /// in the current context (C++ [temp.expl.spec]p2). /// /// \param S the semantic analysis object for which this check is being /// performed. /// /// \param Specialized the entity being specialized or instantiated, which /// may be a kind of template (class template, function template, etc.) or /// a member of a class template (member function, static data member, /// member class). /// /// \param PrevDecl the previous declaration of this entity, if any. /// /// \param Loc the location of the explicit specialization or instantiation of /// this entity. /// /// \param IsPartialSpecialization whether this is a partial specialization of /// a class template. /// /// \returns true if there was an error that we cannot recover from, false /// otherwise. static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized, NamedDecl *PrevDecl, SourceLocation Loc, bool IsPartialSpecialization) { // Keep these "kind" numbers in sync with the %select statements in the // various diagnostics emitted by this routine. int EntityKind = 0; if (isa
(Specialized)) EntityKind = IsPartialSpecialization? 1 : 0; else if (isa
(Specialized)) EntityKind = IsPartialSpecialization ? 3 : 2; else if (isa
(Specialized)) EntityKind = 4; else if (isa
(Specialized)) EntityKind = 5; else if (isa
(Specialized)) EntityKind = 6; else if (isa
(Specialized)) EntityKind = 7; else if (isa
(Specialized) && S.getLangOpts().CPlusPlus11) EntityKind = 8; else { S.Diag(Loc, diag::err_template_spec_unknown_kind) << S.getLangOpts().CPlusPlus11; S.Diag(Specialized->getLocation(), diag::note_specialized_entity); return true; } // C++ [temp.expl.spec]p2: // An explicit specialization shall be declared in the namespace // of which the template is a member, or, for member templates, in // the namespace of which the enclosing class or enclosing class // template is a member. An explicit specialization of a member // function, member class or static data member of a class // template shall be declared in the namespace of which the class // template is a member. Such a declaration may also be a // definition. If the declaration is not a definition, the // specialization may be defined later in the name- space in which // the explicit specialization was declared, or in a namespace // that encloses the one in which the explicit specialization was // declared. if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) { S.Diag(Loc, diag::err_template_spec_decl_function_scope) << Specialized; return true; } if (S.CurContext->isRecord() && !IsPartialSpecialization) { if (S.getLangOpts().MicrosoftExt) { // Do not warn for class scope explicit specialization during // instantiation, warning was already emitted during pattern // semantic analysis. if (!S.ActiveTemplateInstantiations.size()) S.Diag(Loc, diag::ext_function_specialization_in_class) << Specialized; } else { S.Diag(Loc, diag::err_template_spec_decl_class_scope) << Specialized; return true; } } if (S.CurContext->isRecord() && !S.CurContext->Equals(Specialized->getDeclContext())) { // Make sure that we're specializing in the right record context. // Otherwise, things can go horribly wrong. S.Diag(Loc, diag::err_template_spec_decl_class_scope) << Specialized; return true; } // C++ [temp.class.spec]p6: // A class template partial specialization may be declared or redeclared // in any namespace scope in which its definition may be defined (14.5.1 // and 14.5.2). DeclContext *SpecializedContext = Specialized->getDeclContext()->getEnclosingNamespaceContext(); DeclContext *DC = S.CurContext->getEnclosingNamespaceContext(); // Make sure that this redeclaration (or definition) occurs in an enclosing // namespace. // Note that HandleDeclarator() performs this check for explicit // specializations of function templates, static data members, and member // functions, so we skip the check here for those kinds of entities. // FIXME: HandleDeclarator's diagnostics aren't quite as good, though. // Should we refactor that check, so that it occurs later? if (!DC->Encloses(SpecializedContext) && !(isa
(Specialized) || isa
(Specialized) || isa
(Specialized) || isa
(Specialized))) { if (isa
(SpecializedContext)) S.Diag(Loc, diag::err_template_spec_redecl_global_scope) << EntityKind << Specialized; else if (isa
(SpecializedContext)) S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope) << EntityKind << Specialized << cast
(SpecializedContext); else llvm_unreachable("unexpected namespace context for specialization"); S.Diag(Specialized->getLocation(), diag::note_specialized_entity); } else if ((!PrevDecl || getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared || getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)) { // C++ [temp.exp.spec]p2: // An explicit specialization shall be declared in the namespace of which // the template is a member, or, for member templates, in the namespace // of which the enclosing class or enclosing class template is a member. // An explicit specialization of a member function, member class or // static data member of a class template shall be declared in the // namespace of which the class template is a member. // // C++11 [temp.expl.spec]p2: // An explicit specialization shall be declared in a namespace enclosing // the specialized template. // C++11 [temp.explicit]p3: // An explicit instantiation shall appear in an enclosing namespace of its // template. if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) { bool IsCPlusPlus11Extension = DC->Encloses(SpecializedContext); if (isa
(SpecializedContext)) { assert(!IsCPlusPlus11Extension && "DC encloses TU but isn't in enclosing namespace set"); S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global) << EntityKind << Specialized; } else if (isa
(SpecializedContext)) { int Diag; if (!IsCPlusPlus11Extension) Diag = diag::err_template_spec_decl_out_of_scope; else if (!S.getLangOpts().CPlusPlus11) Diag = diag::ext_template_spec_decl_out_of_scope; else Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope; S.Diag(Loc, Diag) << EntityKind << Specialized << cast
(SpecializedContext); } S.Diag(Specialized->getLocation(), diag::note_specialized_entity); } } return false; } static SourceRange findTemplateParameter(unsigned Depth, Expr *E) { if (!E->isInstantiationDependent()) return SourceLocation(); DependencyChecker Checker(Depth); Checker.TraverseStmt(E); if (Checker.Match && Checker.MatchLoc.isInvalid()) return E->getSourceRange(); return Checker.MatchLoc; } static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) { if (!TL.getType()->isDependentType()) return SourceLocation(); DependencyChecker Checker(Depth); Checker.TraverseTypeLoc(TL); if (Checker.Match && Checker.MatchLoc.isInvalid()) return TL.getSourceRange(); return Checker.MatchLoc; } /// \brief Subroutine of Sema::CheckTemplatePartialSpecializationArgs /// that checks non-type template partial specialization arguments. static bool CheckNonTypeTemplatePartialSpecializationArgs( Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param, const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) { for (unsigned I = 0; I != NumArgs; ++I) { if (Args[I].getKind() == TemplateArgument::Pack) { if (CheckNonTypeTemplatePartialSpecializationArgs( S, TemplateNameLoc, Param, Args[I].pack_begin(), Args[I].pack_size(), IsDefaultArgument)) return true; continue; } if (Args[I].getKind() != TemplateArgument::Expression) continue; Expr *ArgExpr = Args[I].getAsExpr(); // We can have a pack expansion of any of the bullets below. if (PackExpansionExpr *Expansion = dyn_cast
(ArgExpr)) ArgExpr = Expansion->getPattern(); // Strip off any implicit casts we added as part of type checking. while (ImplicitCastExpr *ICE = dyn_cast
(ArgExpr)) ArgExpr = ICE->getSubExpr(); // C++ [temp.class.spec]p8: // A non-type argument is non-specialized if it is the name of a // non-type parameter. All other non-type arguments are // specialized. // // Below, we check the two conditions that only apply to // specialized non-type arguments, so skip any non-specialized // arguments. if (DeclRefExpr *DRE = dyn_cast
(ArgExpr)) if (isa
(DRE->getDecl())) continue; // C++ [temp.class.spec]p9: // Within the argument list of a class template partial // specialization, the following restrictions apply: // -- A partially specialized non-type argument expression // shall not involve a template parameter of the partial // specialization except when the argument expression is a // simple identifier. SourceRange ParamUseRange = findTemplateParameter(Param->getDepth(), ArgExpr); if (ParamUseRange.isValid()) { if (IsDefaultArgument) { S.Diag(TemplateNameLoc, diag::err_dependent_non_type_arg_in_partial_spec); S.Diag(ParamUseRange.getBegin(), diag::note_dependent_non_type_default_arg_in_partial_spec) << ParamUseRange; } else { S.Diag(ParamUseRange.getBegin(), diag::err_dependent_non_type_arg_in_partial_spec) << ParamUseRange; } return true; } // -- The type of a template parameter corresponding to a // specialized non-type argument shall not be dependent on a // parameter of the specialization. // // FIXME: We need to delay this check until instantiation in some cases: // // template
class X> struct A { // template
N> struct B; // template
struct B