//===------- SemaTemplateInstantiate.cpp - C++ Template Instantiation ------===/ // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. //===----------------------------------------------------------------------===/ // // This file implements C++ template instantiation. // //===----------------------------------------------------------------------===/ #include "Sema.h" #include "TreeTransform.h" #include "clang/AST/ASTConsumer.h" #include "clang/AST/ASTContext.h" #include "clang/AST/Expr.h" #include "clang/AST/DeclTemplate.h" #include "clang/Parse/DeclSpec.h" #include "clang/Basic/LangOptions.h" #include "llvm/Support/Compiler.h" using namespace clang; //===----------------------------------------------------------------------===/ // Template Instantiation Support //===----------------------------------------------------------------------===/ /// \brief Retrieve the template argument list(s) that should be used to /// instantiate the definition of the given declaration. MultiLevelTemplateArgumentList Sema::getTemplateInstantiationArgs(NamedDecl *D) { // Accumulate the set of template argument lists in this structure. MultiLevelTemplateArgumentList Result; DeclContext *Ctx = dyn_cast(D); if (!Ctx) Ctx = D->getDeclContext(); while (!Ctx->isFileContext()) { // Add template arguments from a class template instantiation. if (ClassTemplateSpecializationDecl *Spec = dyn_cast(Ctx)) { // We're done when we hit an explicit specialization. if (Spec->getSpecializationKind() == TSK_ExplicitSpecialization) break; Result.addOuterTemplateArguments(&Spec->getTemplateInstantiationArgs()); // If this class template specialization was instantiated from a // specialized member that is a class template, we're done. assert(Spec->getSpecializedTemplate() && "No class template?"); if (Spec->getSpecializedTemplate()->isMemberSpecialization()) break; } // Add template arguments from a function template specialization. else if (FunctionDecl *Function = dyn_cast(Ctx)) { if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) break; if (const TemplateArgumentList *TemplateArgs = Function->getTemplateSpecializationArgs()) { // Add the template arguments for this specialization. Result.addOuterTemplateArguments(TemplateArgs); // If this function was instantiated from a specialized member that is // a function template, we're done. assert(Function->getPrimaryTemplate() && "No function template?"); if (Function->getPrimaryTemplate()->isMemberSpecialization()) break; } // If this is a friend declaration and it declares an entity at // namespace scope, take arguments from its lexical parent // instead of its semantic parent. if (Function->getFriendObjectKind() && Function->getDeclContext()->isFileContext()) { Ctx = Function->getLexicalDeclContext(); continue; } } Ctx = Ctx->getParent(); } return Result; } Sema::InstantiatingTemplate:: InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation, Decl *Entity, SourceRange InstantiationRange) : SemaRef(SemaRef) { Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange); if (!Invalid) { ActiveTemplateInstantiation Inst; Inst.Kind = ActiveTemplateInstantiation::TemplateInstantiation; Inst.PointOfInstantiation = PointOfInstantiation; Inst.Entity = reinterpret_cast(Entity); Inst.TemplateArgs = 0; Inst.NumTemplateArgs = 0; Inst.InstantiationRange = InstantiationRange; SemaRef.ActiveTemplateInstantiations.push_back(Inst); Invalid = false; } } Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation, TemplateDecl *Template, const TemplateArgument *TemplateArgs, unsigned NumTemplateArgs, SourceRange InstantiationRange) : SemaRef(SemaRef) { Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange); if (!Invalid) { ActiveTemplateInstantiation Inst; Inst.Kind = ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation; Inst.PointOfInstantiation = PointOfInstantiation; Inst.Entity = reinterpret_cast(Template); Inst.TemplateArgs = TemplateArgs; Inst.NumTemplateArgs = NumTemplateArgs; Inst.InstantiationRange = InstantiationRange; SemaRef.ActiveTemplateInstantiations.push_back(Inst); Invalid = false; } } Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation, FunctionTemplateDecl *FunctionTemplate, const TemplateArgument *TemplateArgs, unsigned NumTemplateArgs, ActiveTemplateInstantiation::InstantiationKind Kind, SourceRange InstantiationRange) : SemaRef(SemaRef) { Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange); if (!Invalid) { ActiveTemplateInstantiation Inst; Inst.Kind = Kind; Inst.PointOfInstantiation = PointOfInstantiation; Inst.Entity = reinterpret_cast(FunctionTemplate); Inst.TemplateArgs = TemplateArgs; Inst.NumTemplateArgs = NumTemplateArgs; Inst.InstantiationRange = InstantiationRange; SemaRef.ActiveTemplateInstantiations.push_back(Inst); Invalid = false; } } Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantiation, ClassTemplatePartialSpecializationDecl *PartialSpec, const TemplateArgument *TemplateArgs, unsigned NumTemplateArgs, SourceRange InstantiationRange) : SemaRef(SemaRef) { Invalid = CheckInstantiationDepth(PointOfInstantiation, InstantiationRange); if (!Invalid) { ActiveTemplateInstantiation Inst; Inst.Kind = ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution; Inst.PointOfInstantiation = PointOfInstantiation; Inst.Entity = reinterpret_cast(PartialSpec); Inst.TemplateArgs = TemplateArgs; Inst.NumTemplateArgs = NumTemplateArgs; Inst.InstantiationRange = InstantiationRange; SemaRef.ActiveTemplateInstantiations.push_back(Inst); Invalid = false; } } Sema::InstantiatingTemplate::InstantiatingTemplate(Sema &SemaRef, SourceLocation PointOfInstantation, ParmVarDecl *Param, const TemplateArgument *TemplateArgs, unsigned NumTemplateArgs, SourceRange InstantiationRange) : SemaRef(SemaRef) { Invalid = CheckInstantiationDepth(PointOfInstantation, InstantiationRange); if (!Invalid) { ActiveTemplateInstantiation Inst; Inst.Kind = ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation; Inst.PointOfInstantiation = PointOfInstantation; Inst.Entity = reinterpret_cast(Param); Inst.TemplateArgs = TemplateArgs; Inst.NumTemplateArgs = NumTemplateArgs; Inst.InstantiationRange = InstantiationRange; SemaRef.ActiveTemplateInstantiations.push_back(Inst); Invalid = false; } } void Sema::InstantiatingTemplate::Clear() { if (!Invalid) { SemaRef.ActiveTemplateInstantiations.pop_back(); Invalid = true; } } bool Sema::InstantiatingTemplate::CheckInstantiationDepth( SourceLocation PointOfInstantiation, SourceRange InstantiationRange) { if (SemaRef.ActiveTemplateInstantiations.size() <= SemaRef.getLangOptions().InstantiationDepth) return false; SemaRef.Diag(PointOfInstantiation, diag::err_template_recursion_depth_exceeded) << SemaRef.getLangOptions().InstantiationDepth << InstantiationRange; SemaRef.Diag(PointOfInstantiation, diag::note_template_recursion_depth) << SemaRef.getLangOptions().InstantiationDepth; return true; } /// \brief Prints the current instantiation stack through a series of /// notes. void Sema::PrintInstantiationStack() { // FIXME: In all of these cases, we need to show the template arguments for (llvm::SmallVector::reverse_iterator Active = ActiveTemplateInstantiations.rbegin(), ActiveEnd = ActiveTemplateInstantiations.rend(); Active != ActiveEnd; ++Active) { switch (Active->Kind) { case ActiveTemplateInstantiation::TemplateInstantiation: { Decl *D = reinterpret_cast(Active->Entity); if (CXXRecordDecl *Record = dyn_cast(D)) { unsigned DiagID = diag::note_template_member_class_here; if (isa(Record)) DiagID = diag::note_template_class_instantiation_here; Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), DiagID) << Context.getTypeDeclType(Record) << Active->InstantiationRange; } else if (FunctionDecl *Function = dyn_cast(D)) { unsigned DiagID; if (Function->getPrimaryTemplate()) DiagID = diag::note_function_template_spec_here; else DiagID = diag::note_template_member_function_here; Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), DiagID) << Function << Active->InstantiationRange; } else { Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_template_static_data_member_def_here) << cast(D) << Active->InstantiationRange; } break; } case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation: { TemplateDecl *Template = cast((Decl *)Active->Entity); std::string TemplateArgsStr = TemplateSpecializationType::PrintTemplateArgumentList( Active->TemplateArgs, Active->NumTemplateArgs, Context.PrintingPolicy); Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_default_arg_instantiation_here) << (Template->getNameAsString() + TemplateArgsStr) << Active->InstantiationRange; break; } case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution: { FunctionTemplateDecl *FnTmpl = cast((Decl *)Active->Entity); Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_explicit_template_arg_substitution_here) << FnTmpl << Active->InstantiationRange; break; } case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution: if (ClassTemplatePartialSpecializationDecl *PartialSpec = dyn_cast( (Decl *)Active->Entity)) { Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_partial_spec_deduct_instantiation_here) << Context.getTypeDeclType(PartialSpec) << Active->InstantiationRange; } else { FunctionTemplateDecl *FnTmpl = cast((Decl *)Active->Entity); Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_function_template_deduction_instantiation_here) << FnTmpl << Active->InstantiationRange; } break; case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation: { ParmVarDecl *Param = cast((Decl *)Active->Entity); FunctionDecl *FD = cast(Param->getDeclContext()); std::string TemplateArgsStr = TemplateSpecializationType::PrintTemplateArgumentList( Active->TemplateArgs, Active->NumTemplateArgs, Context.PrintingPolicy); Diags.Report(FullSourceLoc(Active->PointOfInstantiation, SourceMgr), diag::note_default_function_arg_instantiation_here) << (FD->getNameAsString() + TemplateArgsStr) << Active->InstantiationRange; break; } } } } bool Sema::isSFINAEContext() const { using llvm::SmallVector; for (SmallVector::const_reverse_iterator Active = ActiveTemplateInstantiations.rbegin(), ActiveEnd = ActiveTemplateInstantiations.rend(); Active != ActiveEnd; ++Active) { switch(Active->Kind) { case ActiveTemplateInstantiation::TemplateInstantiation: case ActiveTemplateInstantiation::DefaultFunctionArgumentInstantiation: // This is a template instantiation, so there is no SFINAE. return false; case ActiveTemplateInstantiation::DefaultTemplateArgumentInstantiation: // A default template argument instantiation may or may not be a // SFINAE context; look further up the stack. break; case ActiveTemplateInstantiation::ExplicitTemplateArgumentSubstitution: case ActiveTemplateInstantiation::DeducedTemplateArgumentSubstitution: // We're either substitution explicitly-specified template arguments // or deduced template arguments, so SFINAE applies. return true; } } return false; } //===----------------------------------------------------------------------===/ // Template Instantiation for Types //===----------------------------------------------------------------------===/ namespace { class VISIBILITY_HIDDEN TemplateInstantiator : public TreeTransform { const MultiLevelTemplateArgumentList &TemplateArgs; SourceLocation Loc; DeclarationName Entity; public: typedef TreeTransform inherited; TemplateInstantiator(Sema &SemaRef, const MultiLevelTemplateArgumentList &TemplateArgs, SourceLocation Loc, DeclarationName Entity) : inherited(SemaRef), TemplateArgs(TemplateArgs), Loc(Loc), Entity(Entity) { } /// \brief Determine whether the given type \p T has already been /// transformed. /// /// For the purposes of template instantiation, a type has already been /// transformed if it is NULL or if it is not dependent. bool AlreadyTransformed(QualType T) { return T.isNull() || !T->isDependentType(); } /// \brief Returns the location of the entity being instantiated, if known. SourceLocation getBaseLocation() { return Loc; } /// \brief Returns the name of the entity being instantiated, if any. DeclarationName getBaseEntity() { return Entity; } /// \brief Transform the given declaration by instantiating a reference to /// this declaration. Decl *TransformDecl(Decl *D); /// \brief Transform the definition of the given declaration by /// instantiating it. Decl *TransformDefinition(Decl *D); /// \bried Transform the first qualifier within a scope by instantiating the /// declaration. NamedDecl *TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc); /// \brief Rebuild the exception declaration and register the declaration /// as an instantiated local. VarDecl *RebuildExceptionDecl(VarDecl *ExceptionDecl, QualType T, DeclaratorInfo *Declarator, IdentifierInfo *Name, SourceLocation Loc, SourceRange TypeRange); /// \brief Check for tag mismatches when instantiating an /// elaborated type. QualType RebuildElaboratedType(QualType T, ElaboratedType::TagKind Tag); Sema::OwningExprResult TransformPredefinedExpr(PredefinedExpr *E); Sema::OwningExprResult TransformDeclRefExpr(DeclRefExpr *E); /// \brief Transforms a template type parameter type by performing /// substitution of the corresponding template type argument. QualType TransformTemplateTypeParmType(TypeLocBuilder &TLB, TemplateTypeParmTypeLoc TL); }; } Decl *TemplateInstantiator::TransformDecl(Decl *D) { if (!D) return 0; if (TemplateTemplateParmDecl *TTP = dyn_cast(D)) { if (TTP->getDepth() < TemplateArgs.getNumLevels()) { assert(TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsDecl() && "Wrong kind of template template argument"); return cast(TemplateArgs(TTP->getDepth(), TTP->getPosition()).getAsDecl()); } // If the corresponding template argument is NULL or non-existent, it's // because we are performing instantiation from explicitly-specified // template arguments in a function template, but there were some // arguments left unspecified. if (!TemplateArgs.hasTemplateArgument(TTP->getDepth(), TTP->getPosition())) return D; // FIXME: Implement depth reduction of template template parameters assert(false && "Reducing depth of template template parameters is not yet implemented"); } return SemaRef.FindInstantiatedDecl(cast(D), TemplateArgs); } Decl *TemplateInstantiator::TransformDefinition(Decl *D) { Decl *Inst = getSema().SubstDecl(D, getSema().CurContext, TemplateArgs); if (!Inst) return 0; getSema().CurrentInstantiationScope->InstantiatedLocal(D, Inst); return Inst; } NamedDecl * TemplateInstantiator::TransformFirstQualifierInScope(NamedDecl *D, SourceLocation Loc) { // If the first part of the nested-name-specifier was a template type // parameter, instantiate that type parameter down to a tag type. if (TemplateTypeParmDecl *TTPD = dyn_cast_or_null(D)) { const TemplateTypeParmType *TTP = cast(getSema().Context.getTypeDeclType(TTPD)); if (TTP->getDepth() < TemplateArgs.getNumLevels()) { QualType T = TemplateArgs(TTP->getDepth(), TTP->getIndex()).getAsType(); if (T.isNull()) return cast_or_null(TransformDecl(D)); if (const TagType *Tag = T->getAs()) return Tag->getDecl(); // The resulting type is not a tag; complain. getSema().Diag(Loc, diag::err_nested_name_spec_non_tag) << T; return 0; } } return cast_or_null(TransformDecl(D)); } VarDecl * TemplateInstantiator::RebuildExceptionDecl(VarDecl *ExceptionDecl, QualType T, DeclaratorInfo *Declarator, IdentifierInfo *Name, SourceLocation Loc, SourceRange TypeRange) { VarDecl *Var = inherited::RebuildExceptionDecl(ExceptionDecl, T, Declarator, Name, Loc, TypeRange); if (Var && !Var->isInvalidDecl()) getSema().CurrentInstantiationScope->InstantiatedLocal(ExceptionDecl, Var); return Var; } QualType TemplateInstantiator::RebuildElaboratedType(QualType T, ElaboratedType::TagKind Tag) { if (const TagType *TT = T->getAs()) { TagDecl* TD = TT->getDecl(); // FIXME: this location is very wrong; we really need typelocs. SourceLocation TagLocation = TD->getTagKeywordLoc(); // FIXME: type might be anonymous. IdentifierInfo *Id = TD->getIdentifier(); // TODO: should we even warn on struct/class mismatches for this? Seems // like it's likely to produce a lot of spurious errors. if (!SemaRef.isAcceptableTagRedeclaration(TD, Tag, TagLocation, *Id)) { SemaRef.Diag(TagLocation, diag::err_use_with_wrong_tag) << Id << CodeModificationHint::CreateReplacement(SourceRange(TagLocation), TD->getKindName()); SemaRef.Diag(TD->getLocation(), diag::note_previous_use); } } return TreeTransform::RebuildElaboratedType(T, Tag); } Sema::OwningExprResult TemplateInstantiator::TransformPredefinedExpr(PredefinedExpr *E) { if (!E->isTypeDependent()) return SemaRef.Owned(E->Retain()); FunctionDecl *currentDecl = getSema().getCurFunctionDecl(); assert(currentDecl && "Must have current function declaration when " "instantiating."); PredefinedExpr::IdentType IT = E->getIdentType(); unsigned Length = PredefinedExpr::ComputeName(getSema().Context, IT, currentDecl).length(); llvm::APInt LengthI(32, Length + 1); QualType ResTy = getSema().Context.CharTy.withConst(); ResTy = getSema().Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); PredefinedExpr *PE = new (getSema().Context) PredefinedExpr(E->getLocation(), ResTy, IT); return getSema().Owned(PE); } Sema::OwningExprResult TemplateInstantiator::TransformDeclRefExpr(DeclRefExpr *E) { // FIXME: Clean this up a bit NamedDecl *D = E->getDecl(); if (NonTypeTemplateParmDecl *NTTP = dyn_cast(D)) { if (NTTP->getDepth() >= TemplateArgs.getNumLevels()) { assert(false && "Cannot reduce non-type template parameter depth yet"); return getSema().ExprError(); } // If the corresponding template argument is NULL or non-existent, it's // because we are performing instantiation from explicitly-specified // template arguments in a function template, but there were some // arguments left unspecified. if (!TemplateArgs.hasTemplateArgument(NTTP->getDepth(), NTTP->getPosition())) return SemaRef.Owned(E->Retain()); const TemplateArgument &Arg = TemplateArgs(NTTP->getDepth(), NTTP->getPosition()); // The template argument itself might be an expression, in which // case we just return that expression. if (Arg.getKind() == TemplateArgument::Expression) return SemaRef.Owned(Arg.getAsExpr()->Retain()); if (Arg.getKind() == TemplateArgument::Declaration) { ValueDecl *VD = cast(Arg.getAsDecl()); VD = cast_or_null( getSema().FindInstantiatedDecl(VD, TemplateArgs)); if (!VD) return SemaRef.ExprError(); return SemaRef.BuildDeclRefExpr(VD, VD->getType(), E->getLocation(), /*FIXME:*/false, /*FIXME:*/false); } assert(Arg.getKind() == TemplateArgument::Integral); QualType T = Arg.getIntegralType(); if (T->isCharType() || T->isWideCharType()) return SemaRef.Owned(new (SemaRef.Context) CharacterLiteral( Arg.getAsIntegral()->getZExtValue(), T->isWideCharType(), T, E->getSourceRange().getBegin())); if (T->isBooleanType()) return SemaRef.Owned(new (SemaRef.Context) CXXBoolLiteralExpr( Arg.getAsIntegral()->getBoolValue(), T, E->getSourceRange().getBegin())); assert(Arg.getAsIntegral()->getBitWidth() == SemaRef.Context.getIntWidth(T)); return SemaRef.Owned(new (SemaRef.Context) IntegerLiteral( *Arg.getAsIntegral(), T, E->getSourceRange().getBegin())); } NamedDecl *InstD = SemaRef.FindInstantiatedDecl(D, TemplateArgs); if (!InstD) return SemaRef.ExprError(); // If we instantiated an UnresolvedUsingDecl and got back an UsingDecl, // we need to get the underlying decl. // FIXME: Is this correct? Maybe FindInstantiatedDecl should do this? InstD = InstD->getUnderlyingDecl(); // FIXME: nested-name-specifier for QualifiedDeclRefExpr return SemaRef.BuildDeclarationNameExpr(E->getLocation(), InstD, /*FIXME:*/false, /*FIXME:*/0, /*FIXME:*/false); } QualType TemplateInstantiator::TransformTemplateTypeParmType(TypeLocBuilder &TLB, TemplateTypeParmTypeLoc TL) { TemplateTypeParmType *T = TL.getTypePtr(); if (T->getDepth() < TemplateArgs.getNumLevels()) { // Replace the template type parameter with its corresponding // template argument. // If the corresponding template argument is NULL or doesn't exist, it's // because we are performing instantiation from explicitly-specified // template arguments in a function template class, but there were some // arguments left unspecified. if (!TemplateArgs.hasTemplateArgument(T->getDepth(), T->getIndex())) { TemplateTypeParmTypeLoc NewTL = TLB.push(TL.getType()); NewTL.setNameLoc(TL.getNameLoc()); return TL.getType(); } assert(TemplateArgs(T->getDepth(), T->getIndex()).getKind() == TemplateArgument::Type && "Template argument kind mismatch"); QualType Replacement = TemplateArgs(T->getDepth(), T->getIndex()).getAsType(); // TODO: only do this uniquing once, at the start of instantiation. QualType Result = getSema().Context.getSubstTemplateTypeParmType(T, Replacement); SubstTemplateTypeParmTypeLoc NewTL = TLB.push(Result); NewTL.setNameLoc(TL.getNameLoc()); return Result; } // The template type parameter comes from an inner template (e.g., // the template parameter list of a member template inside the // template we are instantiating). Create a new template type // parameter with the template "level" reduced by one. QualType Result = getSema().Context.getTemplateTypeParmType(T->getDepth() - TemplateArgs.getNumLevels(), T->getIndex(), T->isParameterPack(), T->getName()); TemplateTypeParmTypeLoc NewTL = TLB.push(Result); NewTL.setNameLoc(TL.getNameLoc()); return Result; } /// \brief Perform substitution on the type T with a given set of template /// arguments. /// /// This routine substitutes the given template arguments into the /// type T and produces the instantiated type. /// /// \param T the type into which the template arguments will be /// substituted. If this type is not dependent, it will be returned /// immediately. /// /// \param TemplateArgs the template arguments that will be /// substituted for the top-level template parameters within T. /// /// \param Loc the location in the source code where this substitution /// is being performed. It will typically be the location of the /// declarator (if we're instantiating the type of some declaration) /// or the location of the type in the source code (if, e.g., we're /// instantiating the type of a cast expression). /// /// \param Entity the name of the entity associated with a declaration /// being instantiated (if any). May be empty to indicate that there /// is no such entity (if, e.g., this is a type that occurs as part of /// a cast expression) or that the entity has no name (e.g., an /// unnamed function parameter). /// /// \returns If the instantiation succeeds, the instantiated /// type. Otherwise, produces diagnostics and returns a NULL type. DeclaratorInfo *Sema::SubstType(DeclaratorInfo *T, const MultiLevelTemplateArgumentList &Args, SourceLocation Loc, DeclarationName Entity) { assert(!ActiveTemplateInstantiations.empty() && "Cannot perform an instantiation without some context on the " "instantiation stack"); if (!T->getType()->isDependentType()) return T; TemplateInstantiator Instantiator(*this, Args, Loc, Entity); return Instantiator.TransformType(T); } /// Deprecated form of the above. QualType Sema::SubstType(QualType T, const MultiLevelTemplateArgumentList &TemplateArgs, SourceLocation Loc, DeclarationName Entity) { assert(!ActiveTemplateInstantiations.empty() && "Cannot perform an instantiation without some context on the " "instantiation stack"); // If T is not a dependent type, there is nothing to do. if (!T->isDependentType()) return T; TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, Entity); return Instantiator.TransformType(T); } /// \brief Perform substitution on the base class specifiers of the /// given class template specialization. /// /// Produces a diagnostic and returns true on error, returns false and /// attaches the instantiated base classes to the class template /// specialization if successful. bool Sema::SubstBaseSpecifiers(CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs) { bool Invalid = false; llvm::SmallVector InstantiatedBases; for (ClassTemplateSpecializationDecl::base_class_iterator Base = Pattern->bases_begin(), BaseEnd = Pattern->bases_end(); Base != BaseEnd; ++Base) { if (!Base->getType()->isDependentType()) { InstantiatedBases.push_back(new (Context) CXXBaseSpecifier(*Base)); continue; } QualType BaseType = SubstType(Base->getType(), TemplateArgs, Base->getSourceRange().getBegin(), DeclarationName()); if (BaseType.isNull()) { Invalid = true; continue; } if (CXXBaseSpecifier *InstantiatedBase = CheckBaseSpecifier(Instantiation, Base->getSourceRange(), Base->isVirtual(), Base->getAccessSpecifierAsWritten(), BaseType, /*FIXME: Not totally accurate */ Base->getSourceRange().getBegin())) InstantiatedBases.push_back(InstantiatedBase); else Invalid = true; } if (!Invalid && AttachBaseSpecifiers(Instantiation, InstantiatedBases.data(), InstantiatedBases.size())) Invalid = true; return Invalid; } /// \brief Instantiate the definition of a class from a given pattern. /// /// \param PointOfInstantiation The point of instantiation within the /// source code. /// /// \param Instantiation is the declaration whose definition is being /// instantiated. This will be either a class template specialization /// or a member class of a class template specialization. /// /// \param Pattern is the pattern from which the instantiation /// occurs. This will be either the declaration of a class template or /// the declaration of a member class of a class template. /// /// \param TemplateArgs The template arguments to be substituted into /// the pattern. /// /// \param TSK the kind of implicit or explicit instantiation to perform. /// /// \param Complain whether to complain if the class cannot be instantiated due /// to the lack of a definition. /// /// \returns true if an error occurred, false otherwise. bool Sema::InstantiateClass(SourceLocation PointOfInstantiation, CXXRecordDecl *Instantiation, CXXRecordDecl *Pattern, const MultiLevelTemplateArgumentList &TemplateArgs, TemplateSpecializationKind TSK, bool Complain) { bool Invalid = false; CXXRecordDecl *PatternDef = cast_or_null(Pattern->getDefinition(Context)); if (!PatternDef) { if (!Complain) { // Say nothing } else if (Pattern == Instantiation->getInstantiatedFromMemberClass()) { Diag(PointOfInstantiation, diag::err_implicit_instantiate_member_undefined) << Context.getTypeDeclType(Instantiation); Diag(Pattern->getLocation(), diag::note_member_of_template_here); } else { Diag(PointOfInstantiation, diag::err_template_instantiate_undefined) << (TSK != TSK_ImplicitInstantiation) << Context.getTypeDeclType(Instantiation); Diag(Pattern->getLocation(), diag::note_template_decl_here); } return true; } Pattern = PatternDef; // \brief Record the point of instantiation. if (MemberSpecializationInfo *MSInfo = Instantiation->getMemberSpecializationInfo()) { MSInfo->setTemplateSpecializationKind(TSK); MSInfo->setPointOfInstantiation(PointOfInstantiation); } InstantiatingTemplate Inst(*this, PointOfInstantiation, Instantiation); if (Inst) return true; // Enter the scope of this instantiation. We don't use // PushDeclContext because we don't have a scope. DeclContext *PreviousContext = CurContext; CurContext = Instantiation; // Start the definition of this instantiation. Instantiation->startDefinition(); // Do substitution on the base class specifiers. if (SubstBaseSpecifiers(Instantiation, Pattern, TemplateArgs)) Invalid = true; llvm::SmallVector Fields; for (RecordDecl::decl_iterator Member = Pattern->decls_begin(), MemberEnd = Pattern->decls_end(); Member != MemberEnd; ++Member) { Decl *NewMember = SubstDecl(*Member, Instantiation, TemplateArgs); if (NewMember) { if (NewMember->isInvalidDecl()) Invalid = true; else if (FieldDecl *Field = dyn_cast(NewMember)) Fields.push_back(DeclPtrTy::make(Field)); else if (UsingDecl *UD = dyn_cast(NewMember)) Instantiation->addDecl(UD); } else { // FIXME: Eventually, a NULL return will mean that one of the // instantiations was a semantic disaster, and we'll want to set Invalid = // true. For now, we expect to skip some members that we can't yet handle. } } // Finish checking fields. ActOnFields(0, Instantiation->getLocation(), DeclPtrTy::make(Instantiation), Fields.data(), Fields.size(), SourceLocation(), SourceLocation(), 0); if (Instantiation->isInvalidDecl()) Invalid = true; // Add any implicitly-declared members that we might need. if (!Invalid) AddImplicitlyDeclaredMembersToClass(Instantiation); // Exit the scope of this instantiation. CurContext = PreviousContext; if (!Invalid) Consumer.HandleTagDeclDefinition(Instantiation); // If this is an explicit instantiation, instantiate our members, too. if (!Invalid && TSK != TSK_ImplicitInstantiation) { Inst.Clear(); InstantiateClassMembers(PointOfInstantiation, Instantiation, TemplateArgs, TSK); } return Invalid; } bool Sema::InstantiateClassTemplateSpecialization( ClassTemplateSpecializationDecl *ClassTemplateSpec, TemplateSpecializationKind TSK, bool Complain) { // Perform the actual instantiation on the canonical declaration. ClassTemplateSpec = cast( ClassTemplateSpec->getCanonicalDecl()); // Check whether we have already instantiated or specialized this class // template specialization. if (ClassTemplateSpec->getSpecializationKind() != TSK_Undeclared) { if (ClassTemplateSpec->getSpecializationKind() == TSK_ExplicitInstantiationDeclaration && TSK == TSK_ExplicitInstantiationDefinition) { // An explicit instantiation definition follows an explicit instantiation // declaration (C++0x [temp.explicit]p10); go ahead and perform the // explicit instantiation. ClassTemplateSpec->setSpecializationKind(TSK); InstantiateClassTemplateSpecializationMembers( /*FIXME?*/ClassTemplateSpec->getPointOfInstantiation(), ClassTemplateSpec, TSK); return false; } // We can only instantiate something that hasn't already been // instantiated or specialized. Fail without any diagnostics: our // caller will provide an error message. return true; } if (ClassTemplateSpec->isInvalidDecl()) return true; ClassTemplateDecl *Template = ClassTemplateSpec->getSpecializedTemplate(); CXXRecordDecl *Pattern = 0; // C++ [temp.class.spec.match]p1: // When a class template is used in a context that requires an // instantiation of the class, it is necessary to determine // whether the instantiation is to be generated using the primary // template or one of the partial specializations. This is done by // matching the template arguments of the class template // specialization with the template argument lists of the partial // specializations. typedef std::pair MatchResult; llvm::SmallVector Matched; for (llvm::FoldingSet::iterator Partial = Template->getPartialSpecializations().begin(), PartialEnd = Template->getPartialSpecializations().end(); Partial != PartialEnd; ++Partial) { TemplateDeductionInfo Info(Context); if (TemplateDeductionResult Result = DeduceTemplateArguments(&*Partial, ClassTemplateSpec->getTemplateArgs(), Info)) { // FIXME: Store the failed-deduction information for use in // diagnostics, later. (void)Result; } else { Matched.push_back(std::make_pair(&*Partial, Info.take())); } } if (Matched.size() == 1) { // -- If exactly one matching specialization is found, the // instantiation is generated from that specialization. Pattern = Matched[0].first; ClassTemplateSpec->setInstantiationOf(Matched[0].first, Matched[0].second); } else if (Matched.size() > 1) { // -- 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 class template is // ambiguous and the program is ill-formed. llvm::SmallVector::iterator Best = Matched.begin(); for (llvm::SmallVector::iterator P = Best + 1, PEnd = Matched.end(); P != PEnd; ++P) { if (getMoreSpecializedPartialSpecialization(P->first, Best->first) == P->first) Best = P; } // Determine if the best partial specialization is more specialized than // the others. bool Ambiguous = false; for (llvm::SmallVector::iterator P = Matched.begin(), PEnd = Matched.end(); P != PEnd; ++P) { if (P != Best && getMoreSpecializedPartialSpecialization(P->first, Best->first) != Best->first) { Ambiguous = true; break; } } if (Ambiguous) { // Partial ordering did not produce a clear winner. Complain. ClassTemplateSpec->setInvalidDecl(); Diag(ClassTemplateSpec->getPointOfInstantiation(), diag::err_partial_spec_ordering_ambiguous) << ClassTemplateSpec; // Print the matching partial specializations. for (llvm::SmallVector::iterator P = Matched.begin(), PEnd = Matched.end(); P != PEnd; ++P) Diag(P->first->getLocation(), diag::note_partial_spec_match) << getTemplateArgumentBindingsText(P->first->getTemplateParameters(), *P->second); return true; } // Instantiate using the best class template partial specialization. Pattern = Best->first; ClassTemplateSpec->setInstantiationOf(Best->first, Best->second); } else { // -- If no matches are found, the instantiation is generated // from the primary template. ClassTemplateDecl *OrigTemplate = Template; while (OrigTemplate->getInstantiatedFromMemberTemplate()) { // If we've found an explicit specialization of this class template, // stop here and use that as the pattern. if (OrigTemplate->isMemberSpecialization()) break; OrigTemplate = OrigTemplate->getInstantiatedFromMemberTemplate(); } Pattern = OrigTemplate->getTemplatedDecl(); } // Note that this is an instantiation. ClassTemplateSpec->setSpecializationKind(TSK); bool Result = InstantiateClass(ClassTemplateSpec->getPointOfInstantiation(), ClassTemplateSpec, Pattern, getTemplateInstantiationArgs(ClassTemplateSpec), TSK, Complain); for (unsigned I = 0, N = Matched.size(); I != N; ++I) { // FIXME: Implement TemplateArgumentList::Destroy! // if (Matched[I].first != Pattern) // Matched[I].second->Destroy(Context); } return Result; } /// \brief Instantiates the definitions of all of the member /// of the given class, which is an instantiation of a class template /// or a member class of a template. void Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation, CXXRecordDecl *Instantiation, const MultiLevelTemplateArgumentList &TemplateArgs, TemplateSpecializationKind TSK) { for (DeclContext::decl_iterator D = Instantiation->decls_begin(), DEnd = Instantiation->decls_end(); D != DEnd; ++D) { if (FunctionDecl *Function = dyn_cast(*D)) { if (Function->getInstantiatedFromMemberFunction()) { // If this member was explicitly specialized, do nothing. if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) continue; Function->setTemplateSpecializationKind(TSK, PointOfInstantiation); } if (!Function->getBody() && TSK == TSK_ExplicitInstantiationDefinition) InstantiateFunctionDefinition(PointOfInstantiation, Function); } else if (VarDecl *Var = dyn_cast(*D)) { if (Var->isStaticDataMember()) { // If this member was explicitly specialized, do nothing. if (Var->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) continue; Var->setTemplateSpecializationKind(TSK, PointOfInstantiation); if (TSK == TSK_ExplicitInstantiationDefinition) InstantiateStaticDataMemberDefinition(PointOfInstantiation, Var); } } else if (CXXRecordDecl *Record = dyn_cast(*D)) { if (Record->isInjectedClassName()) continue; assert(Record->getInstantiatedFromMemberClass() && "Missing instantiated-from-template information"); // If this member was explicitly specialized, do nothing. if (Record->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) continue; if (!Record->getDefinition(Context)) InstantiateClass(PointOfInstantiation, Record, Record->getInstantiatedFromMemberClass(), TemplateArgs, TSK); InstantiateClassMembers(PointOfInstantiation, Record, TemplateArgs, TSK); } } } /// \brief Instantiate the definitions of all of the members of the /// given class template specialization, which was named as part of an /// explicit instantiation. void Sema::InstantiateClassTemplateSpecializationMembers( SourceLocation PointOfInstantiation, ClassTemplateSpecializationDecl *ClassTemplateSpec, TemplateSpecializationKind TSK) { // C++0x [temp.explicit]p7: // An explicit instantiation that names a class template // specialization is an explicit instantion of the same kind // (declaration or definition) of each of its members (not // including members inherited from base classes) that has not // been previously explicitly specialized in the translation unit // containing the explicit instantiation, except as described // below. InstantiateClassMembers(PointOfInstantiation, ClassTemplateSpec, getTemplateInstantiationArgs(ClassTemplateSpec), TSK); } Sema::OwningStmtResult Sema::SubstStmt(Stmt *S, const MultiLevelTemplateArgumentList &TemplateArgs) { if (!S) return Owned(S); TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(), DeclarationName()); return Instantiator.TransformStmt(S); } Sema::OwningExprResult Sema::SubstExpr(Expr *E, const MultiLevelTemplateArgumentList &TemplateArgs) { if (!E) return Owned(E); TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(), DeclarationName()); return Instantiator.TransformExpr(E); } /// \brief Do template substitution on a nested-name-specifier. NestedNameSpecifier * Sema::SubstNestedNameSpecifier(NestedNameSpecifier *NNS, SourceRange Range, const MultiLevelTemplateArgumentList &TemplateArgs) { TemplateInstantiator Instantiator(*this, TemplateArgs, Range.getBegin(), DeclarationName()); return Instantiator.TransformNestedNameSpecifier(NNS, Range); } TemplateName Sema::SubstTemplateName(TemplateName Name, SourceLocation Loc, const MultiLevelTemplateArgumentList &TemplateArgs) { TemplateInstantiator Instantiator(*this, TemplateArgs, Loc, DeclarationName()); return Instantiator.TransformTemplateName(Name); } TemplateArgument Sema::Subst(TemplateArgument Arg, const MultiLevelTemplateArgumentList &TemplateArgs) { TemplateInstantiator Instantiator(*this, TemplateArgs, SourceLocation(), DeclarationName()); return Instantiator.TransformTemplateArgument(Arg); }