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//===------- SemaTemplateVariadic.cpp - C++ Variadic 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++0x variadic templates. //===----------------------------------------------------------------------===/ #include "clang/Sema/Sema.h" #include "clang/Sema/Lookup.h" #include "clang/Sema/ParsedTemplate.h" #include "clang/Sema/SemaInternal.h" #include "clang/Sema/Template.h" #include "clang/AST/Expr.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/AST/TypeLoc.h" using namespace clang; //---------------------------------------------------------------------------- // Visitor that collects unexpanded parameter packs //---------------------------------------------------------------------------- namespace { /// \brief A class that collects unexpanded parameter packs. class CollectUnexpandedParameterPacksVisitor : public RecursiveASTVisitor<CollectUnexpandedParameterPacksVisitor> { typedef RecursiveASTVisitor<CollectUnexpandedParameterPacksVisitor> inherited; SmallVectorImpl<UnexpandedParameterPack> &Unexpanded; public: explicit CollectUnexpandedParameterPacksVisitor( SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) : Unexpanded(Unexpanded) { } bool shouldWalkTypesOfTypeLocs() const { return false; } //------------------------------------------------------------------------ // Recording occurrences of (unexpanded) parameter packs. //------------------------------------------------------------------------ /// \brief Record occurrences of template type parameter packs. bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) { if (TL.getTypePtr()->isParameterPack()) Unexpanded.push_back(std::make_pair(TL.getTypePtr(), TL.getNameLoc())); return true; } /// \brief Record occurrences of template type parameter packs /// when we don't have proper source-location information for /// them. /// /// Ideally, this routine would never be used. bool VisitTemplateTypeParmType(TemplateTypeParmType *T) { if (T->isParameterPack()) Unexpanded.push_back(std::make_pair(T, SourceLocation())); return true; } /// \brief Record occurrences of function and non-type template /// parameter packs in an expression. bool VisitDeclRefExpr(DeclRefExpr *E) { if (E->getDecl()->isParameterPack()) Unexpanded.push_back(std::make_pair(E->getDecl(), E->getLocation())); return true; } /// \brief Record occurrences of template template parameter packs. bool TraverseTemplateName(TemplateName Template) { if (TemplateTemplateParmDecl *TTP = dyn_cast_or_null<TemplateTemplateParmDecl>( Template.getAsTemplateDecl())) if (TTP->isParameterPack()) Unexpanded.push_back(std::make_pair(TTP, SourceLocation())); return inherited::TraverseTemplateName(Template); } /// \brief Suppress traversal into Objective-C container literal /// elements that are pack expansions. bool TraverseObjCDictionaryLiteral(ObjCDictionaryLiteral *E) { if (!E->containsUnexpandedParameterPack()) return true; for (unsigned I = 0, N = E->getNumElements(); I != N; ++I) { ObjCDictionaryElement Element = E->getKeyValueElement(I); if (Element.isPackExpansion()) continue; TraverseStmt(Element.Key); TraverseStmt(Element.Value); } return true; } //------------------------------------------------------------------------ // Pruning the search for unexpanded parameter packs. //------------------------------------------------------------------------ /// \brief Suppress traversal into statements and expressions that /// do not contain unexpanded parameter packs. bool TraverseStmt(Stmt *S) { if (Expr *E = dyn_cast_or_null<Expr>(S)) if (E->containsUnexpandedParameterPack()) return inherited::TraverseStmt(E); return true; } /// \brief Suppress traversal into types that do not contain /// unexpanded parameter packs. bool TraverseType(QualType T) { if (!T.isNull() && T->containsUnexpandedParameterPack()) return inherited::TraverseType(T); return true; } /// \brief Suppress traversel into types with location information /// that do not contain unexpanded parameter packs. bool TraverseTypeLoc(TypeLoc TL) { if (!TL.getType().isNull() && TL.getType()->containsUnexpandedParameterPack()) return inherited::TraverseTypeLoc(TL); return true; } /// \brief Suppress traversal of non-parameter declarations, since /// they cannot contain unexpanded parameter packs. bool TraverseDecl(Decl *D) { if (D && isa<ParmVarDecl>(D)) return inherited::TraverseDecl(D); return true; } /// \brief Suppress traversal of template argument pack expansions. bool TraverseTemplateArgument(const TemplateArgument &Arg) { if (Arg.isPackExpansion()) return true; return inherited::TraverseTemplateArgument(Arg); } /// \brief Suppress traversal of template argument pack expansions. bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) { if (ArgLoc.getArgument().isPackExpansion()) return true; return inherited::TraverseTemplateArgumentLoc(ArgLoc); } }; } /// \brief Diagnose all of the unexpanded parameter packs in the given /// vector. void Sema::DiagnoseUnexpandedParameterPacks(SourceLocation Loc, UnexpandedParameterPackContext UPPC, ArrayRef<UnexpandedParameterPack> Unexpanded) { if (Unexpanded.empty()) return; SmallVector<SourceLocation, 4> Locations; SmallVector<IdentifierInfo *, 4> Names; llvm::SmallPtrSet<IdentifierInfo *, 4> NamesKnown; for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) { IdentifierInfo *Name = 0; if (const TemplateTypeParmType *TTP = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>()) Name = TTP->getIdentifier(); else Name = Unexpanded[I].first.get<NamedDecl *>()->getIdentifier(); if (Name && NamesKnown.insert(Name)) Names.push_back(Name); if (Unexpanded[I].second.isValid()) Locations.push_back(Unexpanded[I].second); } DiagnosticBuilder DB = Names.size() == 0? Diag(Loc, diag::err_unexpanded_parameter_pack_0) << (int)UPPC : Names.size() == 1? Diag(Loc, diag::err_unexpanded_parameter_pack_1) << (int)UPPC << Names[0] : Names.size() == 2? Diag(Loc, diag::err_unexpanded_parameter_pack_2) << (int)UPPC << Names[0] << Names[1] : Diag(Loc, diag::err_unexpanded_parameter_pack_3_or_more) << (int)UPPC << Names[0] << Names[1]; for (unsigned I = 0, N = Locations.size(); I != N; ++I) DB << SourceRange(Locations[I]); } bool Sema::DiagnoseUnexpandedParameterPack(SourceLocation Loc, TypeSourceInfo *T, UnexpandedParameterPackContext UPPC) { // C++0x [temp.variadic]p5: // An appearance of a name of a parameter pack that is not expanded is // ill-formed. if (!T->getType()->containsUnexpandedParameterPack()) return false; SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseTypeLoc( T->getTypeLoc()); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded); return true; } bool Sema::DiagnoseUnexpandedParameterPack(Expr *E, UnexpandedParameterPackContext UPPC) { // C++0x [temp.variadic]p5: // An appearance of a name of a parameter pack that is not expanded is // ill-formed. if (!E->containsUnexpandedParameterPack()) return false; SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseStmt(E); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(E->getLocStart(), UPPC, Unexpanded); return true; } bool Sema::DiagnoseUnexpandedParameterPack(const CXXScopeSpec &SS, UnexpandedParameterPackContext UPPC) { // C++0x [temp.variadic]p5: // An appearance of a name of a parameter pack that is not expanded is // ill-formed. if (!SS.getScopeRep() || !SS.getScopeRep()->containsUnexpandedParameterPack()) return false; SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseNestedNameSpecifier(SS.getScopeRep()); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(SS.getRange().getBegin(), UPPC, Unexpanded); return true; } bool Sema::DiagnoseUnexpandedParameterPack(const DeclarationNameInfo &NameInfo, UnexpandedParameterPackContext UPPC) { // C++0x [temp.variadic]p5: // An appearance of a name of a parameter pack that is not expanded is // ill-formed. switch (NameInfo.getName().getNameKind()) { case DeclarationName::Identifier: case DeclarationName::ObjCZeroArgSelector: case DeclarationName::ObjCOneArgSelector: case DeclarationName::ObjCMultiArgSelector: case DeclarationName::CXXOperatorName: case DeclarationName::CXXLiteralOperatorName: case DeclarationName::CXXUsingDirective: return false; case DeclarationName::CXXConstructorName: case DeclarationName::CXXDestructorName: case DeclarationName::CXXConversionFunctionName: // FIXME: We shouldn't need this null check! if (TypeSourceInfo *TSInfo = NameInfo.getNamedTypeInfo()) return DiagnoseUnexpandedParameterPack(NameInfo.getLoc(), TSInfo, UPPC); if (!NameInfo.getName().getCXXNameType()->containsUnexpandedParameterPack()) return false; break; } SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseType(NameInfo.getName().getCXXNameType()); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(NameInfo.getLoc(), UPPC, Unexpanded); return true; } bool Sema::DiagnoseUnexpandedParameterPack(SourceLocation Loc, TemplateName Template, UnexpandedParameterPackContext UPPC) { if (Template.isNull() || !Template.containsUnexpandedParameterPack()) return false; SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseTemplateName(Template); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded); return true; } bool Sema::DiagnoseUnexpandedParameterPack(TemplateArgumentLoc Arg, UnexpandedParameterPackContext UPPC) { if (Arg.getArgument().isNull() || !Arg.getArgument().containsUnexpandedParameterPack()) return false; SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseTemplateArgumentLoc(Arg); assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); DiagnoseUnexpandedParameterPacks(Arg.getLocation(), UPPC, Unexpanded); return true; } void Sema::collectUnexpandedParameterPacks(TemplateArgument Arg, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseTemplateArgument(Arg); } void Sema::collectUnexpandedParameterPacks(TemplateArgumentLoc Arg, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseTemplateArgumentLoc(Arg); } void Sema::collectUnexpandedParameterPacks(QualType T, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(T); } void Sema::collectUnexpandedParameterPacks(TypeLoc TL, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseTypeLoc(TL); } void Sema::collectUnexpandedParameterPacks(CXXScopeSpec &SS, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { NestedNameSpecifier *Qualifier = SS.getScopeRep(); if (!Qualifier) return; NestedNameSpecifierLoc QualifierLoc(Qualifier, SS.location_data()); CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseNestedNameSpecifierLoc(QualifierLoc); } void Sema::collectUnexpandedParameterPacks(const DeclarationNameInfo &NameInfo, SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { CollectUnexpandedParameterPacksVisitor(Unexpanded) .TraverseDeclarationNameInfo(NameInfo); } ParsedTemplateArgument Sema::ActOnPackExpansion(const ParsedTemplateArgument &Arg, SourceLocation EllipsisLoc) { if (Arg.isInvalid()) return Arg; switch (Arg.getKind()) { case ParsedTemplateArgument::Type: { TypeResult Result = ActOnPackExpansion(Arg.getAsType(), EllipsisLoc); if (Result.isInvalid()) return ParsedTemplateArgument(); return ParsedTemplateArgument(Arg.getKind(), Result.get().getAsOpaquePtr(), Arg.getLocation()); } case ParsedTemplateArgument::NonType: { ExprResult Result = ActOnPackExpansion(Arg.getAsExpr(), EllipsisLoc); if (Result.isInvalid()) return ParsedTemplateArgument(); return ParsedTemplateArgument(Arg.getKind(), Result.get(), Arg.getLocation()); } case ParsedTemplateArgument::Template: if (!Arg.getAsTemplate().get().containsUnexpandedParameterPack()) { SourceRange R(Arg.getLocation()); if (Arg.getScopeSpec().isValid()) R.setBegin(Arg.getScopeSpec().getBeginLoc()); Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << R; return ParsedTemplateArgument(); } return Arg.getTemplatePackExpansion(EllipsisLoc); } llvm_unreachable("Unhandled template argument kind?"); } TypeResult Sema::ActOnPackExpansion(ParsedType Type, SourceLocation EllipsisLoc) { TypeSourceInfo *TSInfo; GetTypeFromParser(Type, &TSInfo); if (!TSInfo) return true; TypeSourceInfo *TSResult = CheckPackExpansion(TSInfo, EllipsisLoc, llvm::Optional<unsigned>()); if (!TSResult) return true; return CreateParsedType(TSResult->getType(), TSResult); } TypeSourceInfo *Sema::CheckPackExpansion(TypeSourceInfo *Pattern, SourceLocation EllipsisLoc, llvm::Optional<unsigned> NumExpansions) { // Create the pack expansion type and source-location information. QualType Result = CheckPackExpansion(Pattern->getType(), Pattern->getTypeLoc().getSourceRange(), EllipsisLoc, NumExpansions); if (Result.isNull()) return 0; TypeSourceInfo *TSResult = Context.CreateTypeSourceInfo(Result); PackExpansionTypeLoc TL = cast<PackExpansionTypeLoc>(TSResult->getTypeLoc()); TL.setEllipsisLoc(EllipsisLoc); // Copy over the source-location information from the type. memcpy(TL.getNextTypeLoc().getOpaqueData(), Pattern->getTypeLoc().getOpaqueData(), Pattern->getTypeLoc().getFullDataSize()); return TSResult; } QualType Sema::CheckPackExpansion(QualType Pattern, SourceRange PatternRange, SourceLocation EllipsisLoc, llvm::Optional<unsigned> NumExpansions) { // C++0x [temp.variadic]p5: // The pattern of a pack expansion shall name one or more // parameter packs that are not expanded by a nested pack // expansion. if (!Pattern->containsUnexpandedParameterPack()) { Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << PatternRange; return QualType(); } return Context.getPackExpansionType(Pattern, NumExpansions); } ExprResult Sema::ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc) { return CheckPackExpansion(Pattern, EllipsisLoc, llvm::Optional<unsigned>()); } ExprResult Sema::CheckPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc, llvm::Optional<unsigned> NumExpansions) { if (!Pattern) return ExprError(); // C++0x [temp.variadic]p5: // The pattern of a pack expansion shall name one or more // parameter packs that are not expanded by a nested pack // expansion. if (!Pattern->containsUnexpandedParameterPack()) { Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) << Pattern->getSourceRange(); return ExprError(); } // Create the pack expansion expression and source-location information. return Owned(new (Context) PackExpansionExpr(Context.DependentTy, Pattern, EllipsisLoc, NumExpansions)); } /// \brief Retrieve the depth and index of a parameter pack. static std::pair<unsigned, unsigned> getDepthAndIndex(NamedDecl *ND) { if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ND)) return std::make_pair(TTP->getDepth(), TTP->getIndex()); if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(ND)) return std::make_pair(NTTP->getDepth(), NTTP->getIndex()); TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(ND); return std::make_pair(TTP->getDepth(), TTP->getIndex()); } bool Sema::CheckParameterPacksForExpansion(SourceLocation EllipsisLoc, SourceRange PatternRange, ArrayRef<UnexpandedParameterPack> Unexpanded, const MultiLevelTemplateArgumentList &TemplateArgs, bool &ShouldExpand, bool &RetainExpansion, llvm::Optional<unsigned> &NumExpansions) { ShouldExpand = true; RetainExpansion = false; std::pair<IdentifierInfo *, SourceLocation> FirstPack; bool HaveFirstPack = false; for (ArrayRef<UnexpandedParameterPack>::iterator i = Unexpanded.begin(), end = Unexpanded.end(); i != end; ++i) { // Compute the depth and index for this parameter pack. unsigned Depth = 0, Index = 0; IdentifierInfo *Name; bool IsFunctionParameterPack = false; if (const TemplateTypeParmType *TTP = i->first.dyn_cast<const TemplateTypeParmType *>()) { Depth = TTP->getDepth(); Index = TTP->getIndex(); Name = TTP->getIdentifier(); } else { NamedDecl *ND = i->first.get<NamedDecl *>(); if (isa<ParmVarDecl>(ND)) IsFunctionParameterPack = true; else llvm::tie(Depth, Index) = getDepthAndIndex(ND); Name = ND->getIdentifier(); } // Determine the size of this argument pack. unsigned NewPackSize; if (IsFunctionParameterPack) { // Figure out whether we're instantiating to an argument pack or not. typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack; llvm::PointerUnion<Decl *, DeclArgumentPack *> *Instantiation = CurrentInstantiationScope->findInstantiationOf( i->first.get<NamedDecl *>()); if (Instantiation->is<DeclArgumentPack *>()) { // We could expand this function parameter pack. NewPackSize = Instantiation->get<DeclArgumentPack *>()->size(); } else { // We can't expand this function parameter pack, so we can't expand // the pack expansion. ShouldExpand = false; continue; } } else { // If we don't have a template argument at this depth/index, then we // cannot expand the pack expansion. Make a note of this, but we still // want to check any parameter packs we *do* have arguments for. if (Depth >= TemplateArgs.getNumLevels() || !TemplateArgs.hasTemplateArgument(Depth, Index)) { ShouldExpand = false; continue; } // Determine the size of the argument pack. NewPackSize = TemplateArgs(Depth, Index).pack_size(); } // C++0x [temp.arg.explicit]p9: // Template argument deduction can extend the sequence of template // arguments corresponding to a template parameter pack, even when the // sequence contains explicitly specified template arguments. if (!IsFunctionParameterPack) { if (NamedDecl *PartialPack = CurrentInstantiationScope->getPartiallySubstitutedPack()){ unsigned PartialDepth, PartialIndex; llvm::tie(PartialDepth, PartialIndex) = getDepthAndIndex(PartialPack); if (PartialDepth == Depth && PartialIndex == Index) RetainExpansion = true; } } if (!NumExpansions) { // The is the first pack we've seen for which we have an argument. // Record it. NumExpansions = NewPackSize; FirstPack.first = Name; FirstPack.second = i->second; HaveFirstPack = true; continue; } if (NewPackSize != *NumExpansions) { // C++0x [temp.variadic]p5: // All of the parameter packs expanded by a pack expansion shall have // the same number of arguments specified. if (HaveFirstPack) Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict) << FirstPack.first << Name << *NumExpansions << NewPackSize << SourceRange(FirstPack.second) << SourceRange(i->second); else Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict_multilevel) << Name << *NumExpansions << NewPackSize << SourceRange(i->second); return true; } } return false; } unsigned Sema::getNumArgumentsInExpansion(QualType T, const MultiLevelTemplateArgumentList &TemplateArgs) { QualType Pattern = cast<PackExpansionType>(T)->getPattern(); SmallVector<UnexpandedParameterPack, 2> Unexpanded; CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(Pattern); for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) { // Compute the depth and index for this parameter pack. unsigned Depth; unsigned Index; if (const TemplateTypeParmType *TTP = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>()) { Depth = TTP->getDepth(); Index = TTP->getIndex(); } else { NamedDecl *ND = Unexpanded[I].first.get<NamedDecl *>(); if (isa<ParmVarDecl>(ND)) { // Function parameter pack. typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack; llvm::PointerUnion<Decl *, DeclArgumentPack *> *Instantiation = CurrentInstantiationScope->findInstantiationOf( Unexpanded[I].first.get<NamedDecl *>()); if (Instantiation->is<DeclArgumentPack *>()) return Instantiation->get<DeclArgumentPack *>()->size(); continue; } llvm::tie(Depth, Index) = getDepthAndIndex(ND); } if (Depth >= TemplateArgs.getNumLevels() || !TemplateArgs.hasTemplateArgument(Depth, Index)) continue; // Determine the size of the argument pack. return TemplateArgs(Depth, Index).pack_size(); } llvm_unreachable("No unexpanded parameter packs in type expansion."); } bool Sema::containsUnexpandedParameterPacks(Declarator &D) { const DeclSpec &DS = D.getDeclSpec(); switch (DS.getTypeSpecType()) { case TST_typename: case TST_typeofType: case TST_underlyingType: case TST_atomic: { QualType T = DS.getRepAsType().get(); if (!T.isNull() && T->containsUnexpandedParameterPack()) return true; break; } case TST_typeofExpr: case TST_decltype: if (DS.getRepAsExpr() && DS.getRepAsExpr()->containsUnexpandedParameterPack()) return true; break; case TST_unspecified: case TST_void: case TST_char: case TST_wchar: case TST_char16: case TST_char32: case TST_int: case TST_int128: case TST_half: case TST_float: case TST_double: case TST_bool: case TST_decimal32: case TST_decimal64: case TST_decimal128: case TST_enum: case TST_union: case TST_struct: case TST_class: case TST_auto: case TST_unknown_anytype: case TST_error: break; } for (unsigned I = 0, N = D.getNumTypeObjects(); I != N; ++I) { const DeclaratorChunk &Chunk = D.getTypeObject(I); switch (Chunk.Kind) { case DeclaratorChunk::Pointer: case DeclaratorChunk::Reference: case DeclaratorChunk::Paren: // These declarator chunks cannot contain any parameter packs. break; case DeclaratorChunk::Array: case DeclaratorChunk::Function: case DeclaratorChunk::BlockPointer: // Syntactically, these kinds of declarator chunks all come after the // declarator-id (conceptually), so the parser should not invoke this // routine at this time. llvm_unreachable("Could not have seen this kind of declarator chunk"); case DeclaratorChunk::MemberPointer: if (Chunk.Mem.Scope().getScopeRep() && Chunk.Mem.Scope().getScopeRep()->containsUnexpandedParameterPack()) return true; break; } } return false; } namespace { // Callback to only accept typo corrections that refer to parameter packs. class ParameterPackValidatorCCC : public CorrectionCandidateCallback { public: virtual bool ValidateCandidate(const TypoCorrection &candidate) { NamedDecl *ND = candidate.getCorrectionDecl(); return ND && ND->isParameterPack(); } }; } /// \brief Called when an expression computing the size of a parameter pack /// is parsed. /// /// \code /// template<typename ...Types> struct count { /// static const unsigned value = sizeof...(Types); /// }; /// \endcode /// // /// \param OpLoc The location of the "sizeof" keyword. /// \param Name The name of the parameter pack whose size will be determined. /// \param NameLoc The source location of the name of the parameter pack. /// \param RParenLoc The location of the closing parentheses. ExprResult Sema::ActOnSizeofParameterPackExpr(Scope *S, SourceLocation OpLoc, IdentifierInfo &Name, SourceLocation NameLoc, SourceLocation RParenLoc) { // C++0x [expr.sizeof]p5: // The identifier in a sizeof... expression shall name a parameter pack. LookupResult R(*this, &Name, NameLoc, LookupOrdinaryName); LookupName(R, S); NamedDecl *ParameterPack = 0; ParameterPackValidatorCCC Validator; switch (R.getResultKind()) { case LookupResult::Found: ParameterPack = R.getFoundDecl(); break; case LookupResult::NotFound: case LookupResult::NotFoundInCurrentInstantiation: if (TypoCorrection Corrected = CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, 0, Validator)) { std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOpts())); ParameterPack = Corrected.getCorrectionDecl(); Diag(NameLoc, diag::err_sizeof_pack_no_pack_name_suggest) << &Name << CorrectedQuotedStr << FixItHint::CreateReplacement( NameLoc, Corrected.getAsString(getLangOpts())); Diag(ParameterPack->getLocation(), diag::note_parameter_pack_here) << CorrectedQuotedStr; } case LookupResult::FoundOverloaded: case LookupResult::FoundUnresolvedValue: break; case LookupResult::Ambiguous: DiagnoseAmbiguousLookup(R); return ExprError(); } if (!ParameterPack || !ParameterPack->isParameterPack()) { Diag(NameLoc, diag::err_sizeof_pack_no_pack_name) << &Name; return ExprError(); } MarkAnyDeclReferenced(OpLoc, ParameterPack); return new (Context) SizeOfPackExpr(Context.getSizeType(), OpLoc, ParameterPack, NameLoc, RParenLoc); }