| //===------- 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/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; |
| |
| llvm::SmallVectorImpl<UnexpandedParameterPack> &Unexpanded; |
| |
| public: |
| explicit CollectUnexpandedParameterPacksVisitor( |
| llvm::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 (FIXME: function and) non-type template |
| /// parameter packs in an expression. |
| bool VisitDeclRefExpr(DeclRefExpr *E) { |
| if (NonTypeTemplateParmDecl *NTTP |
| = dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) { |
| if (NTTP->isParameterPack()) |
| Unexpanded.push_back(std::make_pair(NTTP, E->getLocation())); |
| } |
| |
| // FIXME: Function parameter packs. |
| |
| return true; |
| } |
| |
| // FIXME: Record occurrences of template template parameter packs. |
| |
| //------------------------------------------------------------------------ |
| // 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 Diagnose all of the unexpanded parameter packs in the given |
| /// vector. |
| static void |
| DiagnoseUnexpandedParameterPacks(Sema &S, SourceLocation Loc, |
| Sema::UnexpandedParameterPackContext UPPC, |
| const llvm::SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { |
| llvm::SmallVector<SourceLocation, 4> Locations; |
| llvm::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->getName(); |
| 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? S.Diag(Loc, diag::err_unexpanded_parameter_pack_0) |
| << (int)UPPC |
| : Names.size() == 1? S.Diag(Loc, diag::err_unexpanded_parameter_pack_1) |
| << (int)UPPC << Names[0] |
| : Names.size() == 2? S.Diag(Loc, diag::err_unexpanded_parameter_pack_2) |
| << (int)UPPC << Names[0] << Names[1] |
| : S.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; |
| |
| llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseTypeLoc( |
| T->getTypeLoc()); |
| assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); |
| DiagnoseUnexpandedParameterPacks(*this, 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; |
| |
| llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseStmt(E); |
| assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); |
| DiagnoseUnexpandedParameterPacks(*this, 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; |
| |
| llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded) |
| .TraverseNestedNameSpecifier(SS.getScopeRep()); |
| assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); |
| DiagnoseUnexpandedParameterPacks(*this, 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; |
| } |
| |
| llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded) |
| .TraverseType(NameInfo.getName().getCXXNameType()); |
| assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); |
| DiagnoseUnexpandedParameterPacks(*this, NameInfo.getLoc(), UPPC, Unexpanded); |
| return true; |
| } |
| |
| bool Sema::DiagnoseUnexpandedParameterPack(SourceLocation Loc, |
| TemplateName Template, |
| UnexpandedParameterPackContext UPPC) { |
| |
| if (Template.isNull() || !Template.containsUnexpandedParameterPack()) |
| return false; |
| |
| llvm::SmallVector<UnexpandedParameterPack, 2> Unexpanded; |
| CollectUnexpandedParameterPacksVisitor(Unexpanded) |
| .TraverseTemplateName(Template); |
| assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs"); |
| DiagnoseUnexpandedParameterPacks(*this, Loc, UPPC, Unexpanded); |
| return true; |
| } |
| |
| void Sema::collectUnexpandedParameterPacks(TemplateArgument Arg, |
| llvm::SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { |
| CollectUnexpandedParameterPacksVisitor(Unexpanded) |
| .TraverseTemplateArgument(Arg); |
| } |
| |
| void Sema::collectUnexpandedParameterPacks(TemplateArgumentLoc Arg, |
| llvm::SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { |
| CollectUnexpandedParameterPacksVisitor(Unexpanded) |
| .TraverseTemplateArgumentLoc(Arg); |
| } |
| |
| void Sema::collectUnexpandedParameterPacks(QualType T, |
| llvm::SmallVectorImpl<UnexpandedParameterPack> &Unexpanded) { |
| CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(T); |
| } |
| |
| 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: |
| Diag(EllipsisLoc, diag::err_pack_expansion_unsupported); |
| return ParsedTemplateArgument(); |
| } |
| llvm_unreachable("Unhandled template argument kind?"); |
| return ParsedTemplateArgument(); |
| } |
| |
| TypeResult Sema::ActOnPackExpansion(ParsedType Type, |
| SourceLocation EllipsisLoc) { |
| TypeSourceInfo *TSInfo; |
| GetTypeFromParser(Type, &TSInfo); |
| if (!TSInfo) |
| return true; |
| |
| TypeSourceInfo *TSResult = CheckPackExpansion(TSInfo, EllipsisLoc); |
| if (!TSResult) |
| return true; |
| |
| return CreateParsedType(TSResult->getType(), TSResult); |
| } |
| |
| TypeSourceInfo *Sema::CheckPackExpansion(TypeSourceInfo *Pattern, |
| SourceLocation EllipsisLoc) { |
| // 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->getType()->containsUnexpandedParameterPack()) { |
| Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs) |
| << Pattern->getTypeLoc().getSourceRange(); |
| return 0; |
| } |
| |
| // Create the pack expansion type and source-location information. |
| QualType Result = Context.getPackExpansionType(Pattern->getType()); |
| 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; |
| } |
| |
| ExprResult Sema::ActOnPackExpansion(Expr *Pattern, SourceLocation EllipsisLoc) { |
| 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)); |
| } |
| |
| bool Sema::CheckParameterPacksForExpansion(SourceLocation EllipsisLoc, |
| SourceRange PatternRange, |
| const UnexpandedParameterPack *Unexpanded, |
| unsigned NumUnexpanded, |
| const MultiLevelTemplateArgumentList &TemplateArgs, |
| bool &ShouldExpand, |
| unsigned &NumExpansions) { |
| ShouldExpand = true; |
| std::pair<IdentifierInfo *, SourceLocation> FirstPack; |
| bool HaveFirstPack = false; |
| |
| for (unsigned I = 0; I != NumUnexpanded; ++I) { |
| // Compute the depth and index for this parameter pack. |
| unsigned Depth; |
| unsigned Index; |
| IdentifierInfo *Name; |
| |
| if (const TemplateTypeParmType *TTP |
| = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>()) { |
| Depth = TTP->getDepth(); |
| Index = TTP->getIndex(); |
| Name = TTP->getName(); |
| } else { |
| NamedDecl *ND = Unexpanded[I].first.get<NamedDecl *>(); |
| if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ND)) { |
| Depth = TTP->getDepth(); |
| Index = TTP->getIndex(); |
| } else if (NonTypeTemplateParmDecl *NTTP |
| = dyn_cast<NonTypeTemplateParmDecl>(ND)) { |
| Depth = NTTP->getDepth(); |
| Index = NTTP->getIndex(); |
| } else { |
| TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(ND); |
| Depth = TTP->getDepth(); |
| Index = TTP->getIndex(); |
| } |
| // FIXME: Variadic templates function parameter packs? |
| Name = ND->getIdentifier(); |
| } |
| |
| // 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 (!TemplateArgs.hasTemplateArgument(Depth, Index)) { |
| ShouldExpand = false; |
| continue; |
| } |
| |
| // Determine the size of the argument pack. |
| unsigned NewPackSize = TemplateArgs(Depth, Index).pack_size(); |
| if (!HaveFirstPack) { |
| // The is the first pack we've seen for which we have an argument. |
| // Record it. |
| NumExpansions = NewPackSize; |
| FirstPack.first = Name; |
| FirstPack.second = Unexpanded[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. |
| Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict) |
| << FirstPack.first << Name << NumExpansions << NewPackSize |
| << SourceRange(FirstPack.second) << SourceRange(Unexpanded[I].second); |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| bool Sema::containsUnexpandedParameterPacks(Declarator &D) { |
| const DeclSpec &DS = D.getDeclSpec(); |
| switch (DS.getTypeSpecType()) { |
| case TST_typename: |
| case TST_typeofType: { |
| 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_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_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"); |
| break; |
| |
| case DeclaratorChunk::MemberPointer: |
| if (Chunk.Mem.Scope().getScopeRep() && |
| Chunk.Mem.Scope().getScopeRep()->containsUnexpandedParameterPack()) |
| return true; |
| break; |
| } |
| } |
| |
| return false; |
| } |