| //===------- 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/AST/Expr.h" |
| #include "clang/AST/RecursiveASTVisitor.h" |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/Sema/Lookup.h" |
| #include "clang/Sema/ParsedTemplate.h" |
| #include "clang/Sema/ScopeInfo.h" |
| #include "clang/Sema/SemaInternal.h" |
| #include "clang/Sema/Template.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; |
| |
| bool InLambda; |
| |
| public: |
| explicit CollectUnexpandedParameterPacksVisitor( |
| SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) |
| : Unexpanded(Unexpanded), InLambda(false) { } |
| |
| 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) { |
| Expr *E = dyn_cast_or_null<Expr>(S); |
| if ((E && E->containsUnexpandedParameterPack()) || InLambda) |
| return inherited::TraverseStmt(S); |
| |
| return true; |
| } |
| |
| /// \brief Suppress traversal into types that do not contain |
| /// unexpanded parameter packs. |
| bool TraverseType(QualType T) { |
| if ((!T.isNull() && T->containsUnexpandedParameterPack()) || InLambda) |
| 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()) || |
| InLambda) |
| 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)) || InLambda) |
| 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 Note whether we're traversing a lambda containing an unexpanded |
| /// parameter pack. In this case, the unexpanded pack can occur anywhere, |
| /// including all the places where we normally wouldn't look. Within a |
| /// lambda, we don't propagate the 'contains unexpanded parameter pack' bit |
| /// outside an expression. |
| bool TraverseLambdaExpr(LambdaExpr *Lambda) { |
| // The ContainsUnexpandedParameterPack bit on a lambda is always correct, |
| // even if it's contained within another lambda. |
| if (!Lambda->containsUnexpandedParameterPack()) |
| return true; |
| |
| bool WasInLambda = InLambda; |
| InLambda = true; |
| |
| // If any capture names a function parameter pack, that pack is expanded |
| // when the lambda is expanded. |
| for (LambdaExpr::capture_iterator I = Lambda->capture_begin(), |
| E = Lambda->capture_end(); I != E; ++I) |
| if (VarDecl *VD = I->getCapturedVar()) |
| if (VD->isParameterPack()) |
| Unexpanded.push_back(std::make_pair(VD, I->getLocation())); |
| |
| inherited::TraverseLambdaExpr(Lambda); |
| |
| InLambda = WasInLambda; |
| return true; |
| } |
| }; |
| } |
| |
| /// \brief Diagnose all of the unexpanded parameter packs in the given |
| /// vector. |
| bool |
| Sema::DiagnoseUnexpandedParameterPacks(SourceLocation Loc, |
| UnexpandedParameterPackContext UPPC, |
| ArrayRef<UnexpandedParameterPack> Unexpanded) { |
| if (Unexpanded.empty()) |
| return false; |
| |
| // If we are within a lambda expression, that lambda contains an unexpanded |
| // parameter pack, and we are done. |
| // FIXME: Store 'Unexpanded' on the lambda so we don't need to recompute it |
| // later. |
| for (unsigned N = FunctionScopes.size(); N; --N) { |
| if (sema::LambdaScopeInfo *LSI = |
| dyn_cast<sema::LambdaScopeInfo>(FunctionScopes[N-1])) { |
| LSI->ContainsUnexpandedParameterPack = true; |
| return false; |
| } |
| } |
| |
| 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]); |
| return true; |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded); |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(E->getLocStart(), UPPC, Unexpanded); |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(SS.getRange().getBegin(), |
| UPPC, Unexpanded); |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(NameInfo.getLoc(), UPPC, Unexpanded); |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded); |
| } |
| |
| 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"); |
| return DiagnoseUnexpandedParameterPacks(Arg.getLocation(), UPPC, Unexpanded); |
| } |
| |
| 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, None); |
| if (!TSResult) |
| return true; |
| |
| return CreateParsedType(TSResult->getType(), TSResult); |
| } |
| |
| TypeSourceInfo * |
| Sema::CheckPackExpansion(TypeSourceInfo *Pattern, SourceLocation EllipsisLoc, |
| 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 = |
| TSResult->getTypeLoc().castAs<PackExpansionTypeLoc>(); |
| 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, |
| 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, None); |
| } |
| |
| ExprResult Sema::CheckPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc, |
| 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, 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; |
| } |
| |
| Optional<unsigned> Sema::getNumArgumentsInExpansion(QualType T, |
| const MultiLevelTemplateArgumentList &TemplateArgs) { |
| QualType Pattern = cast<PackExpansionType>(T)->getPattern(); |
| SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(Pattern); |
| |
| Optional<unsigned> Result; |
| 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<Decl*>()) |
| // The pattern refers to an unexpanded pack. We're not ready to expand |
| // this pack yet. |
| return None; |
| |
| unsigned Size = Instantiation->get<DeclArgumentPack *>()->size(); |
| assert((!Result || *Result == Size) && "inconsistent pack sizes"); |
| Result = Size; |
| continue; |
| } |
| |
| llvm::tie(Depth, Index) = getDepthAndIndex(ND); |
| } |
| if (Depth >= TemplateArgs.getNumLevels() || |
| !TemplateArgs.hasTemplateArgument(Depth, Index)) |
| // The pattern refers to an unknown template argument. We're not ready to |
| // expand this pack yet. |
| return None; |
| |
| // Determine the size of the argument pack. |
| unsigned Size = TemplateArgs(Depth, Index).pack_size(); |
| assert((!Result || *Result == Size) && "inconsistent pack sizes"); |
| Result = Size; |
| } |
| |
| return Result; |
| } |
| |
| 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_interface: |
| case TST_class: |
| case TST_auto: |
| case TST_unknown_anytype: |
| case TST_image1d_t: |
| case TST_image1d_array_t: |
| case TST_image1d_buffer_t: |
| case TST_image2d_t: |
| case TST_image2d_array_t: |
| case TST_image3d_t: |
| case TST_sampler_t: |
| case TST_event_t: |
| 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, true); |
| |
| return new (Context) SizeOfPackExpr(Context.getSizeType(), OpLoc, |
| ParameterPack, NameLoc, RParenLoc); |
| } |
