diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp | 3411 | 
1 files changed, 3411 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp new file mode 100644 index 000000000000..8afe7aca9750 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -0,0 +1,3411 @@ +//===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl 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 for declarations. +// +//===----------------------------------------------------------------------===/ +#include "clang/Sema/SemaInternal.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/PrettyDeclStackTrace.h" +#include "clang/Sema/Template.h" +#include "clang/AST/ASTConsumer.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/DeclTemplate.h" +#include "clang/AST/DeclVisitor.h" +#include "clang/AST/DependentDiagnostic.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Lex/Preprocessor.h" + +using namespace clang; + +bool TemplateDeclInstantiator::SubstQualifier(const DeclaratorDecl *OldDecl, +                                              DeclaratorDecl *NewDecl) { +  if (!OldDecl->getQualifierLoc()) +    return false; + +  NestedNameSpecifierLoc NewQualifierLoc +    = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(), +                                          TemplateArgs); + +  if (!NewQualifierLoc) +    return true; + +  NewDecl->setQualifierInfo(NewQualifierLoc); +  return false; +} + +bool TemplateDeclInstantiator::SubstQualifier(const TagDecl *OldDecl, +                                              TagDecl *NewDecl) { +  if (!OldDecl->getQualifierLoc()) +    return false; + +  NestedNameSpecifierLoc NewQualifierLoc +  = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(), +                                        TemplateArgs); + +  if (!NewQualifierLoc) +    return true; + +  NewDecl->setQualifierInfo(NewQualifierLoc); +  return false; +} + +// Include attribute instantiation code. +#include "clang/Sema/AttrTemplateInstantiate.inc" + +void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs, +                            const Decl *Tmpl, Decl *New, +                            LateInstantiatedAttrVec *LateAttrs, +                            LocalInstantiationScope *OuterMostScope) { +  for (AttrVec::const_iterator i = Tmpl->attr_begin(), e = Tmpl->attr_end(); +       i != e; ++i) { +    const Attr *TmplAttr = *i; + +    // FIXME: This should be generalized to more than just the AlignedAttr. +    if (const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr)) { +      if (Aligned->isAlignmentDependent()) { +        if (Aligned->isAlignmentExpr()) { +          // The alignment expression is a constant expression. +          EnterExpressionEvaluationContext Unevaluated(*this, +                                                       Sema::ConstantEvaluated); + +          ExprResult Result = SubstExpr(Aligned->getAlignmentExpr(), +                                        TemplateArgs); +          if (!Result.isInvalid()) +            AddAlignedAttr(Aligned->getLocation(), New, Result.takeAs<Expr>()); +        } else { +          TypeSourceInfo *Result = SubstType(Aligned->getAlignmentType(), +                                             TemplateArgs, +                                             Aligned->getLocation(), +                                             DeclarationName()); +          if (Result) +            AddAlignedAttr(Aligned->getLocation(), New, Result); +        } +        continue; +      } +    } + +    if (TmplAttr->isLateParsed() && LateAttrs) { +      // Late parsed attributes must be instantiated and attached after the +      // enclosing class has been instantiated.  See Sema::InstantiateClass. +      LocalInstantiationScope *Saved = 0; +      if (CurrentInstantiationScope) +        Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope); +      LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New)); +    } else { +      Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context, +                                                         *this, TemplateArgs); +      New->addAttr(NewAttr); +    } +  } +} + +Decl * +TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) { +  llvm_unreachable("Translation units cannot be instantiated"); +} + +Decl * +TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) { +  LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                                      D->getIdentifier()); +  Owner->addDecl(Inst); +  return Inst; +} + +Decl * +TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) { +  llvm_unreachable("Namespaces cannot be instantiated"); +} + +Decl * +TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) { +  NamespaceAliasDecl *Inst +    = NamespaceAliasDecl::Create(SemaRef.Context, Owner, +                                 D->getNamespaceLoc(), +                                 D->getAliasLoc(), +                                 D->getIdentifier(), +                                 D->getQualifierLoc(), +                                 D->getTargetNameLoc(), +                                 D->getNamespace()); +  Owner->addDecl(Inst); +  return Inst; +} + +Decl *TemplateDeclInstantiator::InstantiateTypedefNameDecl(TypedefNameDecl *D, +                                                           bool IsTypeAlias) { +  bool Invalid = false; +  TypeSourceInfo *DI = D->getTypeSourceInfo(); +  if (DI->getType()->isInstantiationDependentType() || +      DI->getType()->isVariablyModifiedType()) { +    DI = SemaRef.SubstType(DI, TemplateArgs, +                           D->getLocation(), D->getDeclName()); +    if (!DI) { +      Invalid = true; +      DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy); +    } +  } else { +    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType()); +  } + +  // Create the new typedef +  TypedefNameDecl *Typedef; +  if (IsTypeAlias) +    Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getLocStart(), +                                    D->getLocation(), D->getIdentifier(), DI); +  else +    Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getLocStart(), +                                  D->getLocation(), D->getIdentifier(), DI); +  if (Invalid) +    Typedef->setInvalidDecl(); + +  // If the old typedef was the name for linkage purposes of an anonymous +  // tag decl, re-establish that relationship for the new typedef. +  if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) { +    TagDecl *oldTag = oldTagType->getDecl(); +    if (oldTag->getTypedefNameForAnonDecl() == D) { +      TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl(); +      assert(!newTag->getIdentifier() && !newTag->getTypedefNameForAnonDecl()); +      newTag->setTypedefNameForAnonDecl(Typedef); +    } +  } + +  if (TypedefNameDecl *Prev = D->getPreviousDecl()) { +    NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev, +                                                       TemplateArgs); +    if (!InstPrev) +      return 0; + +    TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev); + +    // If the typedef types are not identical, reject them. +    SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef); + +    Typedef->setPreviousDeclaration(InstPrevTypedef); +  } + +  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef); + +  Typedef->setAccess(D->getAccess()); + +  return Typedef; +} + +Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) { +  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false); +  Owner->addDecl(Typedef); +  return Typedef; +} + +Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) { +  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true); +  Owner->addDecl(Typedef); +  return Typedef; +} + +Decl * +TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) { +  // Create a local instantiation scope for this type alias template, which +  // will contain the instantiations of the template parameters. +  LocalInstantiationScope Scope(SemaRef); + +  TemplateParameterList *TempParams = D->getTemplateParameters(); +  TemplateParameterList *InstParams = SubstTemplateParams(TempParams); +  if (!InstParams) +    return 0; + +  TypeAliasDecl *Pattern = D->getTemplatedDecl(); + +  TypeAliasTemplateDecl *PrevAliasTemplate = 0; +  if (Pattern->getPreviousDecl()) { +    DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName()); +    if (Found.first != Found.second) { +      PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(*Found.first); +    } +  } + +  TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>( +    InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true)); +  if (!AliasInst) +    return 0; + +  TypeAliasTemplateDecl *Inst +    = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                                    D->getDeclName(), InstParams, AliasInst); +  if (PrevAliasTemplate) +    Inst->setPreviousDeclaration(PrevAliasTemplate); + +  Inst->setAccess(D->getAccess()); + +  if (!PrevAliasTemplate) +    Inst->setInstantiatedFromMemberTemplate(D); + +  Owner->addDecl(Inst); + +  return Inst; +} + +Decl *TemplateDeclInstantiator::VisitVarDecl(VarDecl *D) { +  // If this is the variable for an anonymous struct or union, +  // instantiate the anonymous struct/union type first. +  if (const RecordType *RecordTy = D->getType()->getAs<RecordType>()) +    if (RecordTy->getDecl()->isAnonymousStructOrUnion()) +      if (!VisitCXXRecordDecl(cast<CXXRecordDecl>(RecordTy->getDecl()))) +        return 0; + +  // Do substitution on the type of the declaration +  TypeSourceInfo *DI = SemaRef.SubstType(D->getTypeSourceInfo(), +                                         TemplateArgs, +                                         D->getTypeSpecStartLoc(), +                                         D->getDeclName()); +  if (!DI) +    return 0; + +  if (DI->getType()->isFunctionType()) { +    SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function) +      << D->isStaticDataMember() << DI->getType(); +    return 0; +  } + +  // Build the instantiated declaration +  VarDecl *Var = VarDecl::Create(SemaRef.Context, Owner, +                                 D->getInnerLocStart(), +                                 D->getLocation(), D->getIdentifier(), +                                 DI->getType(), DI, +                                 D->getStorageClass(), +                                 D->getStorageClassAsWritten()); +  Var->setThreadSpecified(D->isThreadSpecified()); +  Var->setInitStyle(D->getInitStyle()); +  Var->setCXXForRangeDecl(D->isCXXForRangeDecl()); +  Var->setConstexpr(D->isConstexpr()); + +  // Substitute the nested name specifier, if any. +  if (SubstQualifier(D, Var)) +    return 0; + +  // If we are instantiating a static data member defined +  // out-of-line, the instantiation will have the same lexical +  // context (which will be a namespace scope) as the template. +  if (D->isOutOfLine()) +    Var->setLexicalDeclContext(D->getLexicalDeclContext()); + +  Var->setAccess(D->getAccess()); + +  if (!D->isStaticDataMember()) { +    Var->setUsed(D->isUsed(false)); +    Var->setReferenced(D->isReferenced()); +  } + +  // FIXME: In theory, we could have a previous declaration for variables that +  // are not static data members. +  // FIXME: having to fake up a LookupResult is dumb. +  LookupResult Previous(SemaRef, Var->getDeclName(), Var->getLocation(), +                        Sema::LookupOrdinaryName, Sema::ForRedeclaration); +  if (D->isStaticDataMember()) +    SemaRef.LookupQualifiedName(Previous, Owner, false); +   +  // In ARC, infer 'retaining' for variables of retainable type. +  if (SemaRef.getLangOpts().ObjCAutoRefCount &&  +      SemaRef.inferObjCARCLifetime(Var)) +    Var->setInvalidDecl(); + +  SemaRef.CheckVariableDeclaration(Var, Previous); + +  if (D->isOutOfLine()) { +    D->getLexicalDeclContext()->addDecl(Var); +    Owner->makeDeclVisibleInContext(Var); +  } else { +    Owner->addDecl(Var); +    if (Owner->isFunctionOrMethod()) +      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Var); +  } +  SemaRef.InstantiateAttrs(TemplateArgs, D, Var, LateAttrs, StartingScope); + +  // Link instantiations of static data members back to the template from +  // which they were instantiated. +  if (Var->isStaticDataMember()) +    SemaRef.Context.setInstantiatedFromStaticDataMember(Var, D, +                                                     TSK_ImplicitInstantiation); + +  if (Var->getAnyInitializer()) { +    // We already have an initializer in the class. +  } else if (D->getInit()) { +    if (Var->isStaticDataMember() && !D->isOutOfLine()) +      SemaRef.PushExpressionEvaluationContext(Sema::ConstantEvaluated); +    else +      SemaRef.PushExpressionEvaluationContext(Sema::PotentiallyEvaluated); + +    // Instantiate the initializer. +    ExprResult Init = SemaRef.SubstInitializer(D->getInit(), TemplateArgs, +                                        D->getInitStyle() == VarDecl::CallInit); +    if (!Init.isInvalid()) { +      bool TypeMayContainAuto = true; +      if (Init.get()) { +        bool DirectInit = D->isDirectInit(); +        SemaRef.AddInitializerToDecl(Var, Init.take(), DirectInit, +                                     TypeMayContainAuto); +      } else +        SemaRef.ActOnUninitializedDecl(Var, TypeMayContainAuto); +    } else { +      // FIXME: Not too happy about invalidating the declaration +      // because of a bogus initializer. +      Var->setInvalidDecl(); +    } + +    SemaRef.PopExpressionEvaluationContext(); +  } else if ((!Var->isStaticDataMember() || Var->isOutOfLine()) && +             !Var->isCXXForRangeDecl()) +    SemaRef.ActOnUninitializedDecl(Var, false); + +  // Diagnose unused local variables with dependent types, where the diagnostic +  // will have been deferred. +  if (!Var->isInvalidDecl() && Owner->isFunctionOrMethod() && !Var->isUsed() && +      D->getType()->isDependentType()) +    SemaRef.DiagnoseUnusedDecl(Var); + +  return Var; +} + +Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) { +  AccessSpecDecl* AD +    = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner, +                             D->getAccessSpecifierLoc(), D->getColonLoc()); +  Owner->addHiddenDecl(AD); +  return AD; +} + +Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) { +  bool Invalid = false; +  TypeSourceInfo *DI = D->getTypeSourceInfo(); +  if (DI->getType()->isInstantiationDependentType() || +      DI->getType()->isVariablyModifiedType())  { +    DI = SemaRef.SubstType(DI, TemplateArgs, +                           D->getLocation(), D->getDeclName()); +    if (!DI) { +      DI = D->getTypeSourceInfo(); +      Invalid = true; +    } else if (DI->getType()->isFunctionType()) { +      // C++ [temp.arg.type]p3: +      //   If a declaration acquires a function type through a type +      //   dependent on a template-parameter and this causes a +      //   declaration that does not use the syntactic form of a +      //   function declarator to have function type, the program is +      //   ill-formed. +      SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function) +        << DI->getType(); +      Invalid = true; +    } +  } else { +    SemaRef.MarkDeclarationsReferencedInType(D->getLocation(), DI->getType()); +  } + +  Expr *BitWidth = D->getBitWidth(); +  if (Invalid) +    BitWidth = 0; +  else if (BitWidth) { +    // The bit-width expression is a constant expression. +    EnterExpressionEvaluationContext Unevaluated(SemaRef, +                                                 Sema::ConstantEvaluated); + +    ExprResult InstantiatedBitWidth +      = SemaRef.SubstExpr(BitWidth, TemplateArgs); +    if (InstantiatedBitWidth.isInvalid()) { +      Invalid = true; +      BitWidth = 0; +    } else +      BitWidth = InstantiatedBitWidth.takeAs<Expr>(); +  } + +  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(), +                                            DI->getType(), DI, +                                            cast<RecordDecl>(Owner), +                                            D->getLocation(), +                                            D->isMutable(), +                                            BitWidth, +                                            D->hasInClassInitializer(), +                                            D->getTypeSpecStartLoc(), +                                            D->getAccess(), +                                            0); +  if (!Field) { +    cast<Decl>(Owner)->setInvalidDecl(); +    return 0; +  } + +  SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope); + +  if (Invalid) +    Field->setInvalidDecl(); + +  if (!Field->getDeclName()) { +    // Keep track of where this decl came from. +    SemaRef.Context.setInstantiatedFromUnnamedFieldDecl(Field, D); +  } +  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) { +    if (Parent->isAnonymousStructOrUnion() && +        Parent->getRedeclContext()->isFunctionOrMethod()) +      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field); +  } + +  Field->setImplicit(D->isImplicit()); +  Field->setAccess(D->getAccess()); +  Owner->addDecl(Field); + +  return Field; +} + +Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) { +  NamedDecl **NamedChain = +    new (SemaRef.Context)NamedDecl*[D->getChainingSize()]; + +  int i = 0; +  for (IndirectFieldDecl::chain_iterator PI = +       D->chain_begin(), PE = D->chain_end(); +       PI != PE; ++PI) { +    NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), *PI, +                                              TemplateArgs); +    if (!Next) +      return 0; + +    NamedChain[i++] = Next; +  } + +  QualType T = cast<FieldDecl>(NamedChain[i-1])->getType(); +  IndirectFieldDecl* IndirectField +    = IndirectFieldDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                                D->getIdentifier(), T, +                                NamedChain, D->getChainingSize()); + + +  IndirectField->setImplicit(D->isImplicit()); +  IndirectField->setAccess(D->getAccess()); +  Owner->addDecl(IndirectField); +  return IndirectField; +} + +Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) { +  // Handle friend type expressions by simply substituting template +  // parameters into the pattern type and checking the result. +  if (TypeSourceInfo *Ty = D->getFriendType()) { +    TypeSourceInfo *InstTy; +    // If this is an unsupported friend, don't bother substituting template +    // arguments into it. The actual type referred to won't be used by any +    // parts of Clang, and may not be valid for instantiating. Just use the +    // same info for the instantiated friend. +    if (D->isUnsupportedFriend()) { +      InstTy = Ty; +    } else { +      InstTy = SemaRef.SubstType(Ty, TemplateArgs, +                                 D->getLocation(), DeclarationName()); +    } +    if (!InstTy) +      return 0; + +    FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getLocation(), +                                                 D->getFriendLoc(), InstTy); +    if (!FD) +      return 0; + +    FD->setAccess(AS_public); +    FD->setUnsupportedFriend(D->isUnsupportedFriend()); +    Owner->addDecl(FD); +    return FD; +  } + +  NamedDecl *ND = D->getFriendDecl(); +  assert(ND && "friend decl must be a decl or a type!"); + +  // All of the Visit implementations for the various potential friend +  // declarations have to be carefully written to work for friend +  // objects, with the most important detail being that the target +  // decl should almost certainly not be placed in Owner. +  Decl *NewND = Visit(ND); +  if (!NewND) return 0; + +  FriendDecl *FD = +    FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                       cast<NamedDecl>(NewND), D->getFriendLoc()); +  FD->setAccess(AS_public); +  FD->setUnsupportedFriend(D->isUnsupportedFriend()); +  Owner->addDecl(FD); +  return FD; +} + +Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) { +  Expr *AssertExpr = D->getAssertExpr(); + +  // The expression in a static assertion is a constant expression. +  EnterExpressionEvaluationContext Unevaluated(SemaRef, +                                               Sema::ConstantEvaluated); + +  ExprResult InstantiatedAssertExpr +    = SemaRef.SubstExpr(AssertExpr, TemplateArgs); +  if (InstantiatedAssertExpr.isInvalid()) +    return 0; + +  ExprResult Message(D->getMessage()); +  D->getMessage(); +  return SemaRef.ActOnStaticAssertDeclaration(D->getLocation(), +                                              InstantiatedAssertExpr.get(), +                                              Message.get(), +                                              D->getRParenLoc()); +} + +Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) { +  EnumDecl *PrevDecl = 0; +  if (D->getPreviousDecl()) { +    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(), +                                                   D->getPreviousDecl(), +                                                   TemplateArgs); +    if (!Prev) return 0; +    PrevDecl = cast<EnumDecl>(Prev); +  } + +  EnumDecl *Enum = EnumDecl::Create(SemaRef.Context, Owner, D->getLocStart(), +                                    D->getLocation(), D->getIdentifier(), +                                    PrevDecl, D->isScoped(), +                                    D->isScopedUsingClassTag(), D->isFixed()); +  if (D->isFixed()) { +    if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) { +      // If we have type source information for the underlying type, it means it +      // has been explicitly set by the user. Perform substitution on it before +      // moving on. +      SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc(); +      TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc, +                                                DeclarationName()); +      if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI)) +        Enum->setIntegerType(SemaRef.Context.IntTy); +      else +        Enum->setIntegerTypeSourceInfo(NewTI); +    } else { +      assert(!D->getIntegerType()->isDependentType() +             && "Dependent type without type source info"); +      Enum->setIntegerType(D->getIntegerType()); +    } +  } + +  SemaRef.InstantiateAttrs(TemplateArgs, D, Enum); + +  Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation); +  Enum->setAccess(D->getAccess()); +  if (SubstQualifier(D, Enum)) return 0; +  Owner->addDecl(Enum); + +  EnumDecl *Def = D->getDefinition(); +  if (Def && Def != D) { +    // If this is an out-of-line definition of an enum member template, check +    // that the underlying types match in the instantiation of both +    // declarations. +    if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) { +      SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc(); +      QualType DefnUnderlying = +        SemaRef.SubstType(TI->getType(), TemplateArgs, +                          UnderlyingLoc, DeclarationName()); +      SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(), +                                     DefnUnderlying, Enum); +    } +  } + +  if (D->getDeclContext()->isFunctionOrMethod()) +    SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum); + +  // C++11 [temp.inst]p1: The implicit instantiation of a class template +  // specialization causes the implicit instantiation of the declarations, but +  // not the definitions of scoped member enumerations. +  // FIXME: There appears to be no wording for what happens for an enum defined +  // within a block scope, but we treat that much like a member template. Only +  // instantiate the definition when visiting the definition in that case, since +  // we will visit all redeclarations. +  if (!Enum->isScoped() && Def && +      (!D->getDeclContext()->isFunctionOrMethod() || D->isCompleteDefinition())) +    InstantiateEnumDefinition(Enum, Def); + +  return Enum; +} + +void TemplateDeclInstantiator::InstantiateEnumDefinition( +    EnumDecl *Enum, EnumDecl *Pattern) { +  Enum->startDefinition(); + +  // Update the location to refer to the definition. +  Enum->setLocation(Pattern->getLocation()); + +  SmallVector<Decl*, 4> Enumerators; + +  EnumConstantDecl *LastEnumConst = 0; +  for (EnumDecl::enumerator_iterator EC = Pattern->enumerator_begin(), +         ECEnd = Pattern->enumerator_end(); +       EC != ECEnd; ++EC) { +    // The specified value for the enumerator. +    ExprResult Value = SemaRef.Owned((Expr *)0); +    if (Expr *UninstValue = EC->getInitExpr()) { +      // The enumerator's value expression is a constant expression. +      EnterExpressionEvaluationContext Unevaluated(SemaRef, +                                                   Sema::ConstantEvaluated); + +      Value = SemaRef.SubstExpr(UninstValue, TemplateArgs); +    } + +    // Drop the initial value and continue. +    bool isInvalid = false; +    if (Value.isInvalid()) { +      Value = SemaRef.Owned((Expr *)0); +      isInvalid = true; +    } + +    EnumConstantDecl *EnumConst +      = SemaRef.CheckEnumConstant(Enum, LastEnumConst, +                                  EC->getLocation(), EC->getIdentifier(), +                                  Value.get()); + +    if (isInvalid) { +      if (EnumConst) +        EnumConst->setInvalidDecl(); +      Enum->setInvalidDecl(); +    } + +    if (EnumConst) { +      SemaRef.InstantiateAttrs(TemplateArgs, *EC, EnumConst); + +      EnumConst->setAccess(Enum->getAccess()); +      Enum->addDecl(EnumConst); +      Enumerators.push_back(EnumConst); +      LastEnumConst = EnumConst; + +      if (Pattern->getDeclContext()->isFunctionOrMethod() && +          !Enum->isScoped()) { +        // If the enumeration is within a function or method, record the enum +        // constant as a local. +        SemaRef.CurrentInstantiationScope->InstantiatedLocal(*EC, EnumConst); +      } +    } +  } + +  // FIXME: Fixup LBraceLoc +  SemaRef.ActOnEnumBody(Enum->getLocation(), SourceLocation(), +                        Enum->getRBraceLoc(), Enum, +                        Enumerators.data(), Enumerators.size(), +                        0, 0); +} + +Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) { +  llvm_unreachable("EnumConstantDecls can only occur within EnumDecls."); +} + +Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) { +  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None); + +  // Create a local instantiation scope for this class template, which +  // will contain the instantiations of the template parameters. +  LocalInstantiationScope Scope(SemaRef); +  TemplateParameterList *TempParams = D->getTemplateParameters(); +  TemplateParameterList *InstParams = SubstTemplateParams(TempParams); +  if (!InstParams) +    return NULL; + +  CXXRecordDecl *Pattern = D->getTemplatedDecl(); + +  // Instantiate the qualifier.  We have to do this first in case +  // we're a friend declaration, because if we are then we need to put +  // the new declaration in the appropriate context. +  NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc(); +  if (QualifierLoc) { +    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, +                                                       TemplateArgs); +    if (!QualifierLoc) +      return 0; +  } + +  CXXRecordDecl *PrevDecl = 0; +  ClassTemplateDecl *PrevClassTemplate = 0; + +  if (!isFriend && Pattern->getPreviousDecl()) { +    DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName()); +    if (Found.first != Found.second) { +      PrevClassTemplate = dyn_cast<ClassTemplateDecl>(*Found.first); +      if (PrevClassTemplate) +        PrevDecl = PrevClassTemplate->getTemplatedDecl(); +    } +  } + +  // If this isn't a friend, then it's a member template, in which +  // case we just want to build the instantiation in the +  // specialization.  If it is a friend, we want to build it in +  // the appropriate context. +  DeclContext *DC = Owner; +  if (isFriend) { +    if (QualifierLoc) { +      CXXScopeSpec SS; +      SS.Adopt(QualifierLoc); +      DC = SemaRef.computeDeclContext(SS); +      if (!DC) return 0; +    } else { +      DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(), +                                           Pattern->getDeclContext(), +                                           TemplateArgs); +    } + +    // Look for a previous declaration of the template in the owning +    // context. +    LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(), +                   Sema::LookupOrdinaryName, Sema::ForRedeclaration); +    SemaRef.LookupQualifiedName(R, DC); + +    if (R.isSingleResult()) { +      PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>(); +      if (PrevClassTemplate) +        PrevDecl = PrevClassTemplate->getTemplatedDecl(); +    } + +    if (!PrevClassTemplate && QualifierLoc) { +      SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope) +        << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC +        << QualifierLoc.getSourceRange(); +      return 0; +    } + +    bool AdoptedPreviousTemplateParams = false; +    if (PrevClassTemplate) { +      bool Complain = true; + +      // HACK: libstdc++ 4.2.1 contains an ill-formed friend class +      // template for struct std::tr1::__detail::_Map_base, where the +      // template parameters of the friend declaration don't match the +      // template parameters of the original declaration. In this one +      // case, we don't complain about the ill-formed friend +      // declaration. +      if (isFriend && Pattern->getIdentifier() && +          Pattern->getIdentifier()->isStr("_Map_base") && +          DC->isNamespace() && +          cast<NamespaceDecl>(DC)->getIdentifier() && +          cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) { +        DeclContext *DCParent = DC->getParent(); +        if (DCParent->isNamespace() && +            cast<NamespaceDecl>(DCParent)->getIdentifier() && +            cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) { +          DeclContext *DCParent2 = DCParent->getParent(); +          if (DCParent2->isNamespace() && +              cast<NamespaceDecl>(DCParent2)->getIdentifier() && +              cast<NamespaceDecl>(DCParent2)->getIdentifier()->isStr("std") && +              DCParent2->getParent()->isTranslationUnit()) +            Complain = false; +        } +      } + +      TemplateParameterList *PrevParams +        = PrevClassTemplate->getTemplateParameters(); + +      // Make sure the parameter lists match. +      if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams, +                                                  Complain, +                                                  Sema::TPL_TemplateMatch)) { +        if (Complain) +          return 0; + +        AdoptedPreviousTemplateParams = true; +        InstParams = PrevParams; +      } + +      // Do some additional validation, then merge default arguments +      // from the existing declarations. +      if (!AdoptedPreviousTemplateParams && +          SemaRef.CheckTemplateParameterList(InstParams, PrevParams, +                                             Sema::TPC_ClassTemplate)) +        return 0; +    } +  } + +  CXXRecordDecl *RecordInst +    = CXXRecordDecl::Create(SemaRef.Context, Pattern->getTagKind(), DC, +                            Pattern->getLocStart(), Pattern->getLocation(), +                            Pattern->getIdentifier(), PrevDecl, +                            /*DelayTypeCreation=*/true); + +  if (QualifierLoc) +    RecordInst->setQualifierInfo(QualifierLoc); + +  ClassTemplateDecl *Inst +    = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(), +                                D->getIdentifier(), InstParams, RecordInst, +                                PrevClassTemplate); +  RecordInst->setDescribedClassTemplate(Inst); + +  if (isFriend) { +    if (PrevClassTemplate) +      Inst->setAccess(PrevClassTemplate->getAccess()); +    else +      Inst->setAccess(D->getAccess()); + +    Inst->setObjectOfFriendDecl(PrevClassTemplate != 0); +    // TODO: do we want to track the instantiation progeny of this +    // friend target decl? +  } else { +    Inst->setAccess(D->getAccess()); +    if (!PrevClassTemplate) +      Inst->setInstantiatedFromMemberTemplate(D); +  } + +  // Trigger creation of the type for the instantiation. +  SemaRef.Context.getInjectedClassNameType(RecordInst, +                                    Inst->getInjectedClassNameSpecialization()); + +  // Finish handling of friends. +  if (isFriend) { +    DC->makeDeclVisibleInContext(Inst); +    Inst->setLexicalDeclContext(Owner); +    RecordInst->setLexicalDeclContext(Owner); +    return Inst; +  } + +  if (D->isOutOfLine()) { +    Inst->setLexicalDeclContext(D->getLexicalDeclContext()); +    RecordInst->setLexicalDeclContext(D->getLexicalDeclContext()); +  } + +  Owner->addDecl(Inst); + +  if (!PrevClassTemplate) { +    // Queue up any out-of-line partial specializations of this member +    // class template; the client will force their instantiation once +    // the enclosing class has been instantiated. +    SmallVector<ClassTemplatePartialSpecializationDecl *, 4> PartialSpecs; +    D->getPartialSpecializations(PartialSpecs); +    for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) +      if (PartialSpecs[I]->isOutOfLine()) +        OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I])); +  } + +  return Inst; +} + +Decl * +TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl( +                                   ClassTemplatePartialSpecializationDecl *D) { +  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate(); + +  // Lookup the already-instantiated declaration in the instantiation +  // of the class template and return that. +  DeclContext::lookup_result Found +    = Owner->lookup(ClassTemplate->getDeclName()); +  if (Found.first == Found.second) +    return 0; + +  ClassTemplateDecl *InstClassTemplate +    = dyn_cast<ClassTemplateDecl>(*Found.first); +  if (!InstClassTemplate) +    return 0; + +  if (ClassTemplatePartialSpecializationDecl *Result +        = InstClassTemplate->findPartialSpecInstantiatedFromMember(D)) +    return Result; + +  return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D); +} + +Decl * +TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) { +  // Create a local instantiation scope for this function template, which +  // will contain the instantiations of the template parameters and then get +  // merged with the local instantiation scope for the function template +  // itself. +  LocalInstantiationScope Scope(SemaRef); + +  TemplateParameterList *TempParams = D->getTemplateParameters(); +  TemplateParameterList *InstParams = SubstTemplateParams(TempParams); +  if (!InstParams) +    return NULL; + +  FunctionDecl *Instantiated = 0; +  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl())) +    Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod, +                                                                 InstParams)); +  else +    Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl( +                                                          D->getTemplatedDecl(), +                                                                InstParams)); + +  if (!Instantiated) +    return 0; + +  Instantiated->setAccess(D->getAccess()); + +  // Link the instantiated function template declaration to the function +  // template from which it was instantiated. +  FunctionTemplateDecl *InstTemplate +    = Instantiated->getDescribedFunctionTemplate(); +  InstTemplate->setAccess(D->getAccess()); +  assert(InstTemplate && +         "VisitFunctionDecl/CXXMethodDecl didn't create a template!"); + +  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None); + +  // Link the instantiation back to the pattern *unless* this is a +  // non-definition friend declaration. +  if (!InstTemplate->getInstantiatedFromMemberTemplate() && +      !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition())) +    InstTemplate->setInstantiatedFromMemberTemplate(D); + +  // Make declarations visible in the appropriate context. +  if (!isFriend) +    Owner->addDecl(InstTemplate); + +  return InstTemplate; +} + +Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) { +  CXXRecordDecl *PrevDecl = 0; +  if (D->isInjectedClassName()) +    PrevDecl = cast<CXXRecordDecl>(Owner); +  else if (D->getPreviousDecl()) { +    NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(), +                                                   D->getPreviousDecl(), +                                                   TemplateArgs); +    if (!Prev) return 0; +    PrevDecl = cast<CXXRecordDecl>(Prev); +  } + +  CXXRecordDecl *Record +    = CXXRecordDecl::Create(SemaRef.Context, D->getTagKind(), Owner, +                            D->getLocStart(), D->getLocation(), +                            D->getIdentifier(), PrevDecl); + +  // Substitute the nested name specifier, if any. +  if (SubstQualifier(D, Record)) +    return 0; + +  Record->setImplicit(D->isImplicit()); +  // FIXME: Check against AS_none is an ugly hack to work around the issue that +  // the tag decls introduced by friend class declarations don't have an access +  // specifier. Remove once this area of the code gets sorted out. +  if (D->getAccess() != AS_none) +    Record->setAccess(D->getAccess()); +  if (!D->isInjectedClassName()) +    Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation); + +  // If the original function was part of a friend declaration, +  // inherit its namespace state. +  if (Decl::FriendObjectKind FOK = D->getFriendObjectKind()) +    Record->setObjectOfFriendDecl(FOK == Decl::FOK_Declared); + +  // Make sure that anonymous structs and unions are recorded. +  if (D->isAnonymousStructOrUnion()) { +    Record->setAnonymousStructOrUnion(true); +    if (Record->getDeclContext()->getRedeclContext()->isFunctionOrMethod()) +      SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record); +  } + +  Owner->addDecl(Record); +  return Record; +} + +/// Normal class members are of more specific types and therefore +/// don't make it here.  This function serves two purposes: +///   1) instantiating function templates +///   2) substituting friend declarations +/// FIXME: preserve function definitions in case #2 +Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D, +                                       TemplateParameterList *TemplateParams) { +  // Check whether there is already a function template specialization for +  // this declaration. +  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate(); +  if (FunctionTemplate && !TemplateParams) { +    std::pair<const TemplateArgument *, unsigned> Innermost +      = TemplateArgs.getInnermost(); + +    void *InsertPos = 0; +    FunctionDecl *SpecFunc +      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second, +                                             InsertPos); + +    // If we already have a function template specialization, return it. +    if (SpecFunc) +      return SpecFunc; +  } + +  bool isFriend; +  if (FunctionTemplate) +    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None); +  else +    isFriend = (D->getFriendObjectKind() != Decl::FOK_None); + +  bool MergeWithParentScope = (TemplateParams != 0) || +    Owner->isFunctionOrMethod() || +    !(isa<Decl>(Owner) && +      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod()); +  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope); + +  SmallVector<ParmVarDecl *, 4> Params; +  TypeSourceInfo *TInfo = SubstFunctionType(D, Params); +  if (!TInfo) +    return 0; +  QualType T = TInfo->getType(); + +  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc(); +  if (QualifierLoc) { +    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, +                                                       TemplateArgs); +    if (!QualifierLoc) +      return 0; +  } + +  // If we're instantiating a local function declaration, put the result +  // in the owner;  otherwise we need to find the instantiated context. +  DeclContext *DC; +  if (D->getDeclContext()->isFunctionOrMethod()) +    DC = Owner; +  else if (isFriend && QualifierLoc) { +    CXXScopeSpec SS; +    SS.Adopt(QualifierLoc); +    DC = SemaRef.computeDeclContext(SS); +    if (!DC) return 0; +  } else { +    DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(), +                                         TemplateArgs); +  } + +  FunctionDecl *Function = +      FunctionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(), +                           D->getLocation(), D->getDeclName(), T, TInfo, +                           D->getStorageClass(), D->getStorageClassAsWritten(), +                           D->isInlineSpecified(), D->hasWrittenPrototype(), +                           D->isConstexpr()); + +  if (QualifierLoc) +    Function->setQualifierInfo(QualifierLoc); + +  DeclContext *LexicalDC = Owner; +  if (!isFriend && D->isOutOfLine()) { +    assert(D->getDeclContext()->isFileContext()); +    LexicalDC = D->getDeclContext(); +  } + +  Function->setLexicalDeclContext(LexicalDC); + +  // Attach the parameters +  if (isa<FunctionProtoType>(Function->getType().IgnoreParens())) { +    // Adopt the already-instantiated parameters into our own context. +    for (unsigned P = 0; P < Params.size(); ++P) +      if (Params[P]) +        Params[P]->setOwningFunction(Function); +  } else { +    // Since we were instantiated via a typedef of a function type, create +    // new parameters. +    const FunctionProtoType *Proto +      = Function->getType()->getAs<FunctionProtoType>(); +    assert(Proto && "No function prototype in template instantiation?"); +    for (FunctionProtoType::arg_type_iterator AI = Proto->arg_type_begin(), +         AE = Proto->arg_type_end(); AI != AE; ++AI) { +      ParmVarDecl *Param +        = SemaRef.BuildParmVarDeclForTypedef(Function, Function->getLocation(), +                                             *AI); +      Param->setScopeInfo(0, Params.size()); +      Params.push_back(Param); +    } +  } +  Function->setParams(Params); + +  SourceLocation InstantiateAtPOI; +  if (TemplateParams) { +    // Our resulting instantiation is actually a function template, since we +    // are substituting only the outer template parameters. For example, given +    // +    //   template<typename T> +    //   struct X { +    //     template<typename U> friend void f(T, U); +    //   }; +    // +    //   X<int> x; +    // +    // We are instantiating the friend function template "f" within X<int>, +    // which means substituting int for T, but leaving "f" as a friend function +    // template. +    // Build the function template itself. +    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC, +                                                    Function->getLocation(), +                                                    Function->getDeclName(), +                                                    TemplateParams, Function); +    Function->setDescribedFunctionTemplate(FunctionTemplate); + +    FunctionTemplate->setLexicalDeclContext(LexicalDC); + +    if (isFriend && D->isThisDeclarationADefinition()) { +      // TODO: should we remember this connection regardless of whether +      // the friend declaration provided a body? +      FunctionTemplate->setInstantiatedFromMemberTemplate( +                                           D->getDescribedFunctionTemplate()); +    } +  } else if (FunctionTemplate) { +    // Record this function template specialization. +    std::pair<const TemplateArgument *, unsigned> Innermost +      = TemplateArgs.getInnermost(); +    Function->setFunctionTemplateSpecialization(FunctionTemplate, +                            TemplateArgumentList::CreateCopy(SemaRef.Context, +                                                             Innermost.first, +                                                             Innermost.second), +                                                /*InsertPos=*/0); +  } else if (isFriend) { +    // Note, we need this connection even if the friend doesn't have a body. +    // Its body may exist but not have been attached yet due to deferred +    // parsing. +    // FIXME: It might be cleaner to set this when attaching the body to the +    // friend function declaration, however that would require finding all the +    // instantiations and modifying them. +    Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation); +  } + +  if (InitFunctionInstantiation(Function, D)) +    Function->setInvalidDecl(); + +  bool isExplicitSpecialization = false; + +  LookupResult Previous(SemaRef, Function->getDeclName(), SourceLocation(), +                        Sema::LookupOrdinaryName, Sema::ForRedeclaration); + +  if (DependentFunctionTemplateSpecializationInfo *Info +        = D->getDependentSpecializationInfo()) { +    assert(isFriend && "non-friend has dependent specialization info?"); + +    // This needs to be set now for future sanity. +    Function->setObjectOfFriendDecl(/*HasPrevious*/ true); + +    // Instantiate the explicit template arguments. +    TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(), +                                          Info->getRAngleLoc()); +    if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(), +                      ExplicitArgs, TemplateArgs)) +      return 0; + +    // Map the candidate templates to their instantiations. +    for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) { +      Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(), +                                                Info->getTemplate(I), +                                                TemplateArgs); +      if (!Temp) return 0; + +      Previous.addDecl(cast<FunctionTemplateDecl>(Temp)); +    } + +    if (SemaRef.CheckFunctionTemplateSpecialization(Function, +                                                    &ExplicitArgs, +                                                    Previous)) +      Function->setInvalidDecl(); + +    isExplicitSpecialization = true; + +  } else if (TemplateParams || !FunctionTemplate) { +    // Look only into the namespace where the friend would be declared to +    // find a previous declaration. This is the innermost enclosing namespace, +    // as described in ActOnFriendFunctionDecl. +    SemaRef.LookupQualifiedName(Previous, DC); + +    // In C++, the previous declaration we find might be a tag type +    // (class or enum). In this case, the new declaration will hide the +    // tag type. Note that this does does not apply if we're declaring a +    // typedef (C++ [dcl.typedef]p4). +    if (Previous.isSingleTagDecl()) +      Previous.clear(); +  } + +  SemaRef.CheckFunctionDeclaration(/*Scope*/ 0, Function, Previous, +                                   isExplicitSpecialization); + +  NamedDecl *PrincipalDecl = (TemplateParams +                              ? cast<NamedDecl>(FunctionTemplate) +                              : Function); + +  // If the original function was part of a friend declaration, +  // inherit its namespace state and add it to the owner. +  if (isFriend) { +    NamedDecl *PrevDecl; +    if (TemplateParams) +      PrevDecl = FunctionTemplate->getPreviousDecl(); +    else +      PrevDecl = Function->getPreviousDecl(); + +    PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0); +    DC->makeDeclVisibleInContext(PrincipalDecl); + +    bool queuedInstantiation = false; + +    // C++98 [temp.friend]p5: When a function is defined in a friend function +    //   declaration in a class template, the function is defined at each +    //   instantiation of the class template. The function is defined even if it +    //   is never used. +    // C++11 [temp.friend]p4: When a function is defined in a friend function +    //   declaration in a class template, the function is instantiated when the +    //   function is odr-used. +    // +    // If -Wc++98-compat is enabled, we go through the motions of checking for a +    // redefinition, but don't instantiate the function. +    if ((!SemaRef.getLangOpts().CPlusPlus0x || +         SemaRef.Diags.getDiagnosticLevel( +             diag::warn_cxx98_compat_friend_redefinition, +             Function->getLocation()) +           != DiagnosticsEngine::Ignored) && +        D->isThisDeclarationADefinition()) { +      // Check for a function body. +      const FunctionDecl *Definition = 0; +      if (Function->isDefined(Definition) && +          Definition->getTemplateSpecializationKind() == TSK_Undeclared) { +        SemaRef.Diag(Function->getLocation(), +                     SemaRef.getLangOpts().CPlusPlus0x ? +                       diag::warn_cxx98_compat_friend_redefinition : +                       diag::err_redefinition) << Function->getDeclName(); +        SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition); +        if (!SemaRef.getLangOpts().CPlusPlus0x) +          Function->setInvalidDecl(); +      } +      // Check for redefinitions due to other instantiations of this or +      // a similar friend function. +      else for (FunctionDecl::redecl_iterator R = Function->redecls_begin(), +                                           REnd = Function->redecls_end(); +                R != REnd; ++R) { +        if (*R == Function) +          continue; +        switch (R->getFriendObjectKind()) { +        case Decl::FOK_None: +          if (!SemaRef.getLangOpts().CPlusPlus0x && +              !queuedInstantiation && R->isUsed(false)) { +            if (MemberSpecializationInfo *MSInfo +                = Function->getMemberSpecializationInfo()) { +              if (MSInfo->getPointOfInstantiation().isInvalid()) { +                SourceLocation Loc = R->getLocation(); // FIXME +                MSInfo->setPointOfInstantiation(Loc); +                SemaRef.PendingLocalImplicitInstantiations.push_back( +                                                 std::make_pair(Function, Loc)); +                queuedInstantiation = true; +              } +            } +          } +          break; +        default: +          if (const FunctionDecl *RPattern +              = R->getTemplateInstantiationPattern()) +            if (RPattern->isDefined(RPattern)) { +              SemaRef.Diag(Function->getLocation(), +                           SemaRef.getLangOpts().CPlusPlus0x ? +                             diag::warn_cxx98_compat_friend_redefinition : +                             diag::err_redefinition) +                << Function->getDeclName(); +              SemaRef.Diag(R->getLocation(), diag::note_previous_definition); +              if (!SemaRef.getLangOpts().CPlusPlus0x) +                Function->setInvalidDecl(); +              break; +            } +        } +      } +    } +  } + +  if (Function->isOverloadedOperator() && !DC->isRecord() && +      PrincipalDecl->isInIdentifierNamespace(Decl::IDNS_Ordinary)) +    PrincipalDecl->setNonMemberOperator(); + +  assert(!D->isDefaulted() && "only methods should be defaulted"); +  return Function; +} + +Decl * +TemplateDeclInstantiator::VisitCXXMethodDecl(CXXMethodDecl *D, +                                      TemplateParameterList *TemplateParams, +                                      bool IsClassScopeSpecialization) { +  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate(); +  if (FunctionTemplate && !TemplateParams) { +    // We are creating a function template specialization from a function +    // template. Check whether there is already a function template +    // specialization for this particular set of template arguments. +    std::pair<const TemplateArgument *, unsigned> Innermost +      = TemplateArgs.getInnermost(); + +    void *InsertPos = 0; +    FunctionDecl *SpecFunc +      = FunctionTemplate->findSpecialization(Innermost.first, Innermost.second, +                                             InsertPos); + +    // If we already have a function template specialization, return it. +    if (SpecFunc) +      return SpecFunc; +  } + +  bool isFriend; +  if (FunctionTemplate) +    isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None); +  else +    isFriend = (D->getFriendObjectKind() != Decl::FOK_None); + +  bool MergeWithParentScope = (TemplateParams != 0) || +    !(isa<Decl>(Owner) && +      cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod()); +  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope); + +  // Instantiate enclosing template arguments for friends. +  SmallVector<TemplateParameterList *, 4> TempParamLists; +  unsigned NumTempParamLists = 0; +  if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) { +    TempParamLists.set_size(NumTempParamLists); +    for (unsigned I = 0; I != NumTempParamLists; ++I) { +      TemplateParameterList *TempParams = D->getTemplateParameterList(I); +      TemplateParameterList *InstParams = SubstTemplateParams(TempParams); +      if (!InstParams) +        return NULL; +      TempParamLists[I] = InstParams; +    } +  } + +  SmallVector<ParmVarDecl *, 4> Params; +  TypeSourceInfo *TInfo = SubstFunctionType(D, Params); +  if (!TInfo) +    return 0; +  QualType T = TInfo->getType(); + +  // \brief If the type of this function, after ignoring parentheses, +  // is not *directly* a function type, then we're instantiating a function +  // that was declared via a typedef, e.g., +  // +  //   typedef int functype(int, int); +  //   functype func; +  // +  // In this case, we'll just go instantiate the ParmVarDecls that we +  // synthesized in the method declaration. +  if (!isa<FunctionProtoType>(T.IgnoreParens())) { +    assert(!Params.size() && "Instantiating type could not yield parameters"); +    SmallVector<QualType, 4> ParamTypes; +    if (SemaRef.SubstParmTypes(D->getLocation(), D->param_begin(), +                               D->getNumParams(), TemplateArgs, ParamTypes, +                               &Params)) +      return 0; +  } + +  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc(); +  if (QualifierLoc) { +    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, +                                                 TemplateArgs); +    if (!QualifierLoc) +      return 0; +  } + +  DeclContext *DC = Owner; +  if (isFriend) { +    if (QualifierLoc) { +      CXXScopeSpec SS; +      SS.Adopt(QualifierLoc); +      DC = SemaRef.computeDeclContext(SS); + +      if (DC && SemaRef.RequireCompleteDeclContext(SS, DC)) +        return 0; +    } else { +      DC = SemaRef.FindInstantiatedContext(D->getLocation(), +                                           D->getDeclContext(), +                                           TemplateArgs); +    } +    if (!DC) return 0; +  } + +  // Build the instantiated method declaration. +  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC); +  CXXMethodDecl *Method = 0; + +  SourceLocation StartLoc = D->getInnerLocStart(); +  DeclarationNameInfo NameInfo +    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs); +  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { +    Method = CXXConstructorDecl::Create(SemaRef.Context, Record, +                                        StartLoc, NameInfo, T, TInfo, +                                        Constructor->isExplicit(), +                                        Constructor->isInlineSpecified(), +                                        false, Constructor->isConstexpr()); +  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { +    Method = CXXDestructorDecl::Create(SemaRef.Context, Record, +                                       StartLoc, NameInfo, T, TInfo, +                                       Destructor->isInlineSpecified(), +                                       false); +  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) { +    Method = CXXConversionDecl::Create(SemaRef.Context, Record, +                                       StartLoc, NameInfo, T, TInfo, +                                       Conversion->isInlineSpecified(), +                                       Conversion->isExplicit(), +                                       Conversion->isConstexpr(), +                                       Conversion->getLocEnd()); +  } else { +    Method = CXXMethodDecl::Create(SemaRef.Context, Record, +                                   StartLoc, NameInfo, T, TInfo, +                                   D->isStatic(), +                                   D->getStorageClassAsWritten(), +                                   D->isInlineSpecified(), +                                   D->isConstexpr(), D->getLocEnd()); +  } + +  if (QualifierLoc) +    Method->setQualifierInfo(QualifierLoc); + +  if (TemplateParams) { +    // Our resulting instantiation is actually a function template, since we +    // are substituting only the outer template parameters. For example, given +    // +    //   template<typename T> +    //   struct X { +    //     template<typename U> void f(T, U); +    //   }; +    // +    //   X<int> x; +    // +    // We are instantiating the member template "f" within X<int>, which means +    // substituting int for T, but leaving "f" as a member function template. +    // Build the function template itself. +    FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record, +                                                    Method->getLocation(), +                                                    Method->getDeclName(), +                                                    TemplateParams, Method); +    if (isFriend) { +      FunctionTemplate->setLexicalDeclContext(Owner); +      FunctionTemplate->setObjectOfFriendDecl(true); +    } else if (D->isOutOfLine()) +      FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext()); +    Method->setDescribedFunctionTemplate(FunctionTemplate); +  } else if (FunctionTemplate) { +    // Record this function template specialization. +    std::pair<const TemplateArgument *, unsigned> Innermost +      = TemplateArgs.getInnermost(); +    Method->setFunctionTemplateSpecialization(FunctionTemplate, +                         TemplateArgumentList::CreateCopy(SemaRef.Context, +                                                          Innermost.first, +                                                          Innermost.second), +                                              /*InsertPos=*/0); +  } else if (!isFriend) { +    // Record that this is an instantiation of a member function. +    Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation); +  } + +  // If we are instantiating a member function defined +  // out-of-line, the instantiation will have the same lexical +  // context (which will be a namespace scope) as the template. +  if (isFriend) { +    if (NumTempParamLists) +      Method->setTemplateParameterListsInfo(SemaRef.Context, +                                            NumTempParamLists, +                                            TempParamLists.data()); + +    Method->setLexicalDeclContext(Owner); +    Method->setObjectOfFriendDecl(true); +  } else if (D->isOutOfLine()) +    Method->setLexicalDeclContext(D->getLexicalDeclContext()); + +  // Attach the parameters +  for (unsigned P = 0; P < Params.size(); ++P) +    Params[P]->setOwningFunction(Method); +  Method->setParams(Params); + +  if (InitMethodInstantiation(Method, D)) +    Method->setInvalidDecl(); + +  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName, +                        Sema::ForRedeclaration); + +  if (!FunctionTemplate || TemplateParams || isFriend) { +    SemaRef.LookupQualifiedName(Previous, Record); + +    // In C++, the previous declaration we find might be a tag type +    // (class or enum). In this case, the new declaration will hide the +    // tag type. Note that this does does not apply if we're declaring a +    // typedef (C++ [dcl.typedef]p4). +    if (Previous.isSingleTagDecl()) +      Previous.clear(); +  } + +  if (!IsClassScopeSpecialization) +    SemaRef.CheckFunctionDeclaration(0, Method, Previous, false); + +  if (D->isPure()) +    SemaRef.CheckPureMethod(Method, SourceRange()); + +  Method->setAccess(D->getAccess()); + +  SemaRef.CheckOverrideControl(Method); + +  // If a function is defined as defaulted or deleted, mark it as such now. +  if (D->isDefaulted()) +    Method->setDefaulted(); +  if (D->isDeletedAsWritten()) +    Method->setDeletedAsWritten(); + +  if (FunctionTemplate) { +    // If there's a function template, let our caller handle it. +  } else if (Method->isInvalidDecl() && !Previous.empty()) { +    // Don't hide a (potentially) valid declaration with an invalid one. +  } else { +    NamedDecl *DeclToAdd = (TemplateParams +                            ? cast<NamedDecl>(FunctionTemplate) +                            : Method); +    if (isFriend) +      Record->makeDeclVisibleInContext(DeclToAdd); +    else if (!IsClassScopeSpecialization) +      Owner->addDecl(DeclToAdd); +  } + +  if (D->isExplicitlyDefaulted()) { +    SemaRef.SetDeclDefaulted(Method, Method->getLocation()); +  } else { +    assert(!D->isDefaulted() && +           "should not implicitly default uninstantiated function"); +  } + +  return Method; +} + +Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) { +  return VisitCXXMethodDecl(D); +} + +Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) { +  return VisitCXXMethodDecl(D); +} + +Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) { +  return VisitCXXMethodDecl(D); +} + +ParmVarDecl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) { +  return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, +                                  llvm::Optional<unsigned>(), +                                  /*ExpectParameterPack=*/false); +} + +Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl( +                                                    TemplateTypeParmDecl *D) { +  // TODO: don't always clone when decls are refcounted. +  assert(D->getTypeForDecl()->isTemplateTypeParmType()); + +  TemplateTypeParmDecl *Inst = +    TemplateTypeParmDecl::Create(SemaRef.Context, Owner, +                                 D->getLocStart(), D->getLocation(), +                                 D->getDepth() - TemplateArgs.getNumLevels(), +                                 D->getIndex(), D->getIdentifier(), +                                 D->wasDeclaredWithTypename(), +                                 D->isParameterPack()); +  Inst->setAccess(AS_public); + +  if (D->hasDefaultArgument()) +    Inst->setDefaultArgument(D->getDefaultArgumentInfo(), false); + +  // Introduce this template parameter's instantiation into the instantiation +  // scope. +  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst); + +  return Inst; +} + +Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl( +                                                 NonTypeTemplateParmDecl *D) { +  // Substitute into the type of the non-type template parameter. +  TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc(); +  SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten; +  SmallVector<QualType, 4> ExpandedParameterPackTypes; +  bool IsExpandedParameterPack = false; +  TypeSourceInfo *DI; +  QualType T; +  bool Invalid = false; + +  if (D->isExpandedParameterPack()) { +    // The non-type template parameter pack is an already-expanded pack +    // expansion of types. Substitute into each of the expanded types. +    ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes()); +    ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes()); +    for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) { +      TypeSourceInfo *NewDI =SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), +                                               TemplateArgs, +                                               D->getLocation(), +                                               D->getDeclName()); +      if (!NewDI) +        return 0; + +      ExpandedParameterPackTypesAsWritten.push_back(NewDI); +      QualType NewT =SemaRef.CheckNonTypeTemplateParameterType(NewDI->getType(), +                                                              D->getLocation()); +      if (NewT.isNull()) +        return 0; +      ExpandedParameterPackTypes.push_back(NewT); +    } + +    IsExpandedParameterPack = true; +    DI = D->getTypeSourceInfo(); +    T = DI->getType(); +  } else if (isa<PackExpansionTypeLoc>(TL)) { +    // The non-type template parameter pack's type is a pack expansion of types. +    // Determine whether we need to expand this parameter pack into separate +    // types. +    PackExpansionTypeLoc Expansion = cast<PackExpansionTypeLoc>(TL); +    TypeLoc Pattern = Expansion.getPatternLoc(); +    SmallVector<UnexpandedParameterPack, 2> Unexpanded; +    SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded); + +    // Determine whether the set of unexpanded parameter packs can and should +    // be expanded. +    bool Expand = true; +    bool RetainExpansion = false; +    llvm::Optional<unsigned> OrigNumExpansions +      = Expansion.getTypePtr()->getNumExpansions(); +    llvm::Optional<unsigned> NumExpansions = OrigNumExpansions; +    if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(), +                                                Pattern.getSourceRange(), +                                                Unexpanded, +                                                TemplateArgs, +                                                Expand, RetainExpansion, +                                                NumExpansions)) +      return 0; + +    if (Expand) { +      for (unsigned I = 0; I != *NumExpansions; ++I) { +        Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I); +        TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs, +                                                  D->getLocation(), +                                                  D->getDeclName()); +        if (!NewDI) +          return 0; + +        ExpandedParameterPackTypesAsWritten.push_back(NewDI); +        QualType NewT = SemaRef.CheckNonTypeTemplateParameterType( +                                                              NewDI->getType(), +                                                              D->getLocation()); +        if (NewT.isNull()) +          return 0; +        ExpandedParameterPackTypes.push_back(NewT); +      } + +      // Note that we have an expanded parameter pack. The "type" of this +      // expanded parameter pack is the original expansion type, but callers +      // will end up using the expanded parameter pack types for type-checking. +      IsExpandedParameterPack = true; +      DI = D->getTypeSourceInfo(); +      T = DI->getType(); +    } else { +      // We cannot fully expand the pack expansion now, so substitute into the +      // pattern and create a new pack expansion type. +      Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1); +      TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs, +                                                     D->getLocation(), +                                                     D->getDeclName()); +      if (!NewPattern) +        return 0; + +      DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(), +                                      NumExpansions); +      if (!DI) +        return 0; + +      T = DI->getType(); +    } +  } else { +    // Simple case: substitution into a parameter that is not a parameter pack. +    DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs, +                           D->getLocation(), D->getDeclName()); +    if (!DI) +      return 0; + +    // Check that this type is acceptable for a non-type template parameter. +    T = SemaRef.CheckNonTypeTemplateParameterType(DI->getType(), +                                                  D->getLocation()); +    if (T.isNull()) { +      T = SemaRef.Context.IntTy; +      Invalid = true; +    } +  } + +  NonTypeTemplateParmDecl *Param; +  if (IsExpandedParameterPack) +    Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, +                                            D->getInnerLocStart(), +                                            D->getLocation(), +                                    D->getDepth() - TemplateArgs.getNumLevels(), +                                            D->getPosition(), +                                            D->getIdentifier(), T, +                                            DI, +                                            ExpandedParameterPackTypes.data(), +                                            ExpandedParameterPackTypes.size(), +                                    ExpandedParameterPackTypesAsWritten.data()); +  else +    Param = NonTypeTemplateParmDecl::Create(SemaRef.Context, Owner, +                                            D->getInnerLocStart(), +                                            D->getLocation(), +                                    D->getDepth() - TemplateArgs.getNumLevels(), +                                            D->getPosition(), +                                            D->getIdentifier(), T, +                                            D->isParameterPack(), DI); + +  Param->setAccess(AS_public); +  if (Invalid) +    Param->setInvalidDecl(); + +  Param->setDefaultArgument(D->getDefaultArgument(), false); + +  // Introduce this template parameter's instantiation into the instantiation +  // scope. +  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param); +  return Param; +} + +Decl * +TemplateDeclInstantiator::VisitTemplateTemplateParmDecl( +                                                  TemplateTemplateParmDecl *D) { +  // Instantiate the template parameter list of the template template parameter. +  TemplateParameterList *TempParams = D->getTemplateParameters(); +  TemplateParameterList *InstParams; +  { +    // Perform the actual substitution of template parameters within a new, +    // local instantiation scope. +    LocalInstantiationScope Scope(SemaRef); +    InstParams = SubstTemplateParams(TempParams); +    if (!InstParams) +      return NULL; +  } + +  // Build the template template parameter. +  TemplateTemplateParmDecl *Param +    = TemplateTemplateParmDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                                   D->getDepth() - TemplateArgs.getNumLevels(), +                                       D->getPosition(), D->isParameterPack(), +                                       D->getIdentifier(), InstParams); +  Param->setDefaultArgument(D->getDefaultArgument(), false); +  Param->setAccess(AS_public); + +  // Introduce this template parameter's instantiation into the instantiation +  // scope. +  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param); + +  return Param; +} + +Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) { +  // Using directives are never dependent (and never contain any types or +  // expressions), so they require no explicit instantiation work. + +  UsingDirectiveDecl *Inst +    = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(), +                                 D->getNamespaceKeyLocation(), +                                 D->getQualifierLoc(), +                                 D->getIdentLocation(), +                                 D->getNominatedNamespace(), +                                 D->getCommonAncestor()); +  Owner->addDecl(Inst); +  return Inst; +} + +Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) { + +  // The nested name specifier may be dependent, for example +  //     template <typename T> struct t { +  //       struct s1 { T f1(); }; +  //       struct s2 : s1 { using s1::f1; }; +  //     }; +  //     template struct t<int>; +  // Here, in using s1::f1, s1 refers to t<T>::s1; +  // we need to substitute for t<int>::s1. +  NestedNameSpecifierLoc QualifierLoc +    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), +                                          TemplateArgs); +  if (!QualifierLoc) +    return 0; + +  // The name info is non-dependent, so no transformation +  // is required. +  DeclarationNameInfo NameInfo = D->getNameInfo(); + +  // We only need to do redeclaration lookups if we're in a class +  // scope (in fact, it's not really even possible in non-class +  // scopes). +  bool CheckRedeclaration = Owner->isRecord(); + +  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName, +                    Sema::ForRedeclaration); + +  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner, +                                       D->getUsingLocation(), +                                       QualifierLoc, +                                       NameInfo, +                                       D->isTypeName()); + +  CXXScopeSpec SS; +  SS.Adopt(QualifierLoc); +  if (CheckRedeclaration) { +    Prev.setHideTags(false); +    SemaRef.LookupQualifiedName(Prev, Owner); + +    // Check for invalid redeclarations. +    if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLocation(), +                                            D->isTypeName(), SS, +                                            D->getLocation(), Prev)) +      NewUD->setInvalidDecl(); + +  } + +  if (!NewUD->isInvalidDecl() && +      SemaRef.CheckUsingDeclQualifier(D->getUsingLocation(), SS, +                                      D->getLocation())) +    NewUD->setInvalidDecl(); + +  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D); +  NewUD->setAccess(D->getAccess()); +  Owner->addDecl(NewUD); + +  // Don't process the shadow decls for an invalid decl. +  if (NewUD->isInvalidDecl()) +    return NewUD; + +  if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName) { +    if (SemaRef.CheckInheritingConstructorUsingDecl(NewUD)) +      NewUD->setInvalidDecl(); +    return NewUD; +  } + +  bool isFunctionScope = Owner->isFunctionOrMethod(); + +  // Process the shadow decls. +  for (UsingDecl::shadow_iterator I = D->shadow_begin(), E = D->shadow_end(); +         I != E; ++I) { +    UsingShadowDecl *Shadow = *I; +    NamedDecl *InstTarget = +      cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl( +                                                          Shadow->getLocation(), +                                                        Shadow->getTargetDecl(), +                                                           TemplateArgs)); +    if (!InstTarget) +      return 0; + +    if (CheckRedeclaration && +        SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev)) +      continue; + +    UsingShadowDecl *InstShadow +      = SemaRef.BuildUsingShadowDecl(/*Scope*/ 0, NewUD, InstTarget); +    SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow); + +    if (isFunctionScope) +      SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow); +  } + +  return NewUD; +} + +Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) { +  // Ignore these;  we handle them in bulk when processing the UsingDecl. +  return 0; +} + +Decl * TemplateDeclInstantiator +    ::VisitUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) { +  NestedNameSpecifierLoc QualifierLoc +    = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), +                                          TemplateArgs); +  if (!QualifierLoc) +    return 0; + +  CXXScopeSpec SS; +  SS.Adopt(QualifierLoc); + +  // Since NameInfo refers to a typename, it cannot be a C++ special name. +  // Hence, no tranformation is required for it. +  DeclarationNameInfo NameInfo(D->getDeclName(), D->getLocation()); +  NamedDecl *UD = +    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(), +                                  D->getUsingLoc(), SS, NameInfo, 0, +                                  /*instantiation*/ true, +                                  /*typename*/ true, D->getTypenameLoc()); +  if (UD) +    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D); + +  return UD; +} + +Decl * TemplateDeclInstantiator +    ::VisitUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) { +  NestedNameSpecifierLoc QualifierLoc +      = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(), TemplateArgs); +  if (!QualifierLoc) +    return 0; + +  CXXScopeSpec SS; +  SS.Adopt(QualifierLoc); + +  DeclarationNameInfo NameInfo +    = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs); + +  NamedDecl *UD = +    SemaRef.BuildUsingDeclaration(/*Scope*/ 0, D->getAccess(), +                                  D->getUsingLoc(), SS, NameInfo, 0, +                                  /*instantiation*/ true, +                                  /*typename*/ false, SourceLocation()); +  if (UD) +    SemaRef.Context.setInstantiatedFromUsingDecl(cast<UsingDecl>(UD), D); + +  return UD; +} + + +Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl( +                                     ClassScopeFunctionSpecializationDecl *Decl) { +  CXXMethodDecl *OldFD = Decl->getSpecialization(); +  CXXMethodDecl *NewFD = cast<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, 0, true)); + +  LookupResult Previous(SemaRef, NewFD->getNameInfo(), Sema::LookupOrdinaryName, +                        Sema::ForRedeclaration); + +  SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext); +  if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, 0, Previous)) { +    NewFD->setInvalidDecl(); +    return NewFD; +  } + +  // Associate the specialization with the pattern. +  FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl()); +  assert(Specialization && "Class scope Specialization is null"); +  SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD); + +  return NewFD; +} + +Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner, +                      const MultiLevelTemplateArgumentList &TemplateArgs) { +  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs); +  if (D->isInvalidDecl()) +    return 0; + +  return Instantiator.Visit(D); +} + +/// \brief Instantiates a nested template parameter list in the current +/// instantiation context. +/// +/// \param L The parameter list to instantiate +/// +/// \returns NULL if there was an error +TemplateParameterList * +TemplateDeclInstantiator::SubstTemplateParams(TemplateParameterList *L) { +  // Get errors for all the parameters before bailing out. +  bool Invalid = false; + +  unsigned N = L->size(); +  typedef SmallVector<NamedDecl *, 8> ParamVector; +  ParamVector Params; +  Params.reserve(N); +  for (TemplateParameterList::iterator PI = L->begin(), PE = L->end(); +       PI != PE; ++PI) { +    NamedDecl *D = cast_or_null<NamedDecl>(Visit(*PI)); +    Params.push_back(D); +    Invalid = Invalid || !D || D->isInvalidDecl(); +  } + +  // Clean up if we had an error. +  if (Invalid) +    return NULL; + +  TemplateParameterList *InstL +    = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(), +                                    L->getLAngleLoc(), &Params.front(), N, +                                    L->getRAngleLoc()); +  return InstL; +} + +/// \brief Instantiate the declaration of a class template partial +/// specialization. +/// +/// \param ClassTemplate the (instantiated) class template that is partially +// specialized by the instantiation of \p PartialSpec. +/// +/// \param PartialSpec the (uninstantiated) class template partial +/// specialization that we are instantiating. +/// +/// \returns The instantiated partial specialization, if successful; otherwise, +/// NULL to indicate an error. +ClassTemplatePartialSpecializationDecl * +TemplateDeclInstantiator::InstantiateClassTemplatePartialSpecialization( +                                            ClassTemplateDecl *ClassTemplate, +                          ClassTemplatePartialSpecializationDecl *PartialSpec) { +  // Create a local instantiation scope for this class template partial +  // specialization, which will contain the instantiations of the template +  // parameters. +  LocalInstantiationScope Scope(SemaRef); + +  // Substitute into the template parameters of the class template partial +  // specialization. +  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters(); +  TemplateParameterList *InstParams = SubstTemplateParams(TempParams); +  if (!InstParams) +    return 0; + +  // Substitute into the template arguments of the class template partial +  // specialization. +  TemplateArgumentListInfo InstTemplateArgs; // no angle locations +  if (SemaRef.Subst(PartialSpec->getTemplateArgsAsWritten(), +                    PartialSpec->getNumTemplateArgsAsWritten(), +                    InstTemplateArgs, TemplateArgs)) +    return 0; + +  // Check that the template argument list is well-formed for this +  // class template. +  SmallVector<TemplateArgument, 4> Converted; +  if (SemaRef.CheckTemplateArgumentList(ClassTemplate, +                                        PartialSpec->getLocation(), +                                        InstTemplateArgs, +                                        false, +                                        Converted)) +    return 0; + +  // Figure out where to insert this class template partial specialization +  // in the member template's set of class template partial specializations. +  void *InsertPos = 0; +  ClassTemplateSpecializationDecl *PrevDecl +    = ClassTemplate->findPartialSpecialization(Converted.data(), +                                               Converted.size(), InsertPos); + +  // Build the canonical type that describes the converted template +  // arguments of the class template partial specialization. +  QualType CanonType +    = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate), +                                                    Converted.data(), +                                                    Converted.size()); + +  // Build the fully-sugared type for this class template +  // specialization as the user wrote in the specialization +  // itself. This means that we'll pretty-print the type retrieved +  // from the specialization's declaration the way that the user +  // actually wrote the specialization, rather than formatting the +  // name based on the "canonical" representation used to store the +  // template arguments in the specialization. +  TypeSourceInfo *WrittenTy +    = SemaRef.Context.getTemplateSpecializationTypeInfo( +                                                    TemplateName(ClassTemplate), +                                                    PartialSpec->getLocation(), +                                                    InstTemplateArgs, +                                                    CanonType); + +  if (PrevDecl) { +    // We've already seen a partial specialization with the same template +    // parameters and template arguments. This can happen, for example, when +    // substituting the outer template arguments ends up causing two +    // class template partial specializations of a member class template +    // to have identical forms, e.g., +    // +    //   template<typename T, typename U> +    //   struct Outer { +    //     template<typename X, typename Y> struct Inner; +    //     template<typename Y> struct Inner<T, Y>; +    //     template<typename Y> struct Inner<U, Y>; +    //   }; +    // +    //   Outer<int, int> outer; // error: the partial specializations of Inner +    //                          // have the same signature. +    SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared) +      << WrittenTy->getType(); +    SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here) +      << SemaRef.Context.getTypeDeclType(PrevDecl); +    return 0; +  } + + +  // Create the class template partial specialization declaration. +  ClassTemplatePartialSpecializationDecl *InstPartialSpec +    = ClassTemplatePartialSpecializationDecl::Create(SemaRef.Context, +                                                     PartialSpec->getTagKind(), +                                                     Owner, +                                                     PartialSpec->getLocStart(), +                                                     PartialSpec->getLocation(), +                                                     InstParams, +                                                     ClassTemplate, +                                                     Converted.data(), +                                                     Converted.size(), +                                                     InstTemplateArgs, +                                                     CanonType, +                                                     0, +                             ClassTemplate->getNextPartialSpecSequenceNumber()); +  // Substitute the nested name specifier, if any. +  if (SubstQualifier(PartialSpec, InstPartialSpec)) +    return 0; + +  InstPartialSpec->setInstantiatedFromMember(PartialSpec); +  InstPartialSpec->setTypeAsWritten(WrittenTy); + +  // Add this partial specialization to the set of class template partial +  // specializations. +  ClassTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/0); +  return InstPartialSpec; +} + +TypeSourceInfo* +TemplateDeclInstantiator::SubstFunctionType(FunctionDecl *D, +                              SmallVectorImpl<ParmVarDecl *> &Params) { +  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo(); +  assert(OldTInfo && "substituting function without type source info"); +  assert(Params.empty() && "parameter vector is non-empty at start"); +  TypeSourceInfo *NewTInfo +    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs, +                                    D->getTypeSpecStartLoc(), +                                    D->getDeclName()); +  if (!NewTInfo) +    return 0; + +  if (NewTInfo != OldTInfo) { +    // Get parameters from the new type info. +    TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens(); +    if (FunctionProtoTypeLoc *OldProtoLoc +                                  = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) { +      TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens(); +      FunctionProtoTypeLoc *NewProtoLoc = cast<FunctionProtoTypeLoc>(&NewTL); +      assert(NewProtoLoc && "Missing prototype?"); +      unsigned NewIdx = 0, NumNewParams = NewProtoLoc->getNumArgs(); +      for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc->getNumArgs(); +           OldIdx != NumOldParams; ++OldIdx) { +        ParmVarDecl *OldParam = OldProtoLoc->getArg(OldIdx); +        if (!OldParam->isParameterPack() || +            // FIXME: Is this right? OldParam could expand to an empty parameter +            // pack and the next parameter could be an unexpanded parameter pack +            (NewIdx < NumNewParams && +             NewProtoLoc->getArg(NewIdx)->isParameterPack())) { +          // Simple case: normal parameter, or a parameter pack that's +          // instantiated to a (still-dependent) parameter pack. +          ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++); +          Params.push_back(NewParam); +          SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam, +                                                               NewParam); +          continue; +        } + +        // Parameter pack: make the instantiation an argument pack. +        SemaRef.CurrentInstantiationScope->MakeInstantiatedLocalArgPack( +                                                                      OldParam); +        unsigned NumArgumentsInExpansion +          = SemaRef.getNumArgumentsInExpansion(OldParam->getType(), +                                               TemplateArgs); +        while (NumArgumentsInExpansion--) { +          ParmVarDecl *NewParam = NewProtoLoc->getArg(NewIdx++); +          Params.push_back(NewParam); +          SemaRef.CurrentInstantiationScope->InstantiatedLocalPackArg(OldParam, +                                                                      NewParam); +        } +      } +    } +  } else { +    // The function type itself was not dependent and therefore no +    // substitution occurred. However, we still need to instantiate +    // the function parameters themselves. +    TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens(); +    if (FunctionProtoTypeLoc *OldProtoLoc +                                    = dyn_cast<FunctionProtoTypeLoc>(&OldTL)) { +      for (unsigned i = 0, i_end = OldProtoLoc->getNumArgs(); i != i_end; ++i) { +        ParmVarDecl *Parm = VisitParmVarDecl(OldProtoLoc->getArg(i)); +        if (!Parm) +          return 0; +        Params.push_back(Parm); +      } +    } +  } +  return NewTInfo; +} + +/// \brief Initializes the common fields of an instantiation function +/// declaration (New) from the corresponding fields of its template (Tmpl). +/// +/// \returns true if there was an error +bool +TemplateDeclInstantiator::InitFunctionInstantiation(FunctionDecl *New, +                                                    FunctionDecl *Tmpl) { +  if (Tmpl->isDeletedAsWritten()) +    New->setDeletedAsWritten(); + +  // If we are performing substituting explicitly-specified template arguments +  // or deduced template arguments into a function template and we reach this +  // point, we are now past the point where SFINAE applies and have committed +  // to keeping the new function template specialization. We therefore +  // convert the active template instantiation for the function template +  // into a template instantiation for this specific function template +  // specialization, which is not a SFINAE context, so that we diagnose any +  // further errors in the declaration itself. +  typedef Sema::ActiveTemplateInstantiation ActiveInstType; +  ActiveInstType &ActiveInst = SemaRef.ActiveTemplateInstantiations.back(); +  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution || +      ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) { +    if (FunctionTemplateDecl *FunTmpl +          = dyn_cast<FunctionTemplateDecl>((Decl *)ActiveInst.Entity)) { +      assert(FunTmpl->getTemplatedDecl() == Tmpl && +             "Deduction from the wrong function template?"); +      (void) FunTmpl; +      ActiveInst.Kind = ActiveInstType::TemplateInstantiation; +      ActiveInst.Entity = reinterpret_cast<uintptr_t>(New); +      --SemaRef.NonInstantiationEntries; +    } +  } + +  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>(); +  assert(Proto && "Function template without prototype?"); + +  if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) { +    // The function has an exception specification or a "noreturn" +    // attribute. Substitute into each of the exception types. +    SmallVector<QualType, 4> Exceptions; +    for (unsigned I = 0, N = Proto->getNumExceptions(); I != N; ++I) { +      // FIXME: Poor location information! +      if (const PackExpansionType *PackExpansion +            = Proto->getExceptionType(I)->getAs<PackExpansionType>()) { +        // We have a pack expansion. Instantiate it. +        SmallVector<UnexpandedParameterPack, 2> Unexpanded; +        SemaRef.collectUnexpandedParameterPacks(PackExpansion->getPattern(), +                                                Unexpanded); +        assert(!Unexpanded.empty() && +               "Pack expansion without parameter packs?"); + +        bool Expand = false; +        bool RetainExpansion = false; +        llvm::Optional<unsigned> NumExpansions +                                          = PackExpansion->getNumExpansions(); +        if (SemaRef.CheckParameterPacksForExpansion(New->getLocation(), +                                                    SourceRange(), +                                                    Unexpanded, +                                                    TemplateArgs, +                                                    Expand, +                                                    RetainExpansion, +                                                    NumExpansions)) +          break; + +        if (!Expand) { +          // We can't expand this pack expansion into separate arguments yet; +          // just substitute into the pattern and create a new pack expansion +          // type. +          Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1); +          QualType T = SemaRef.SubstType(PackExpansion->getPattern(), +                                         TemplateArgs, +                                       New->getLocation(), New->getDeclName()); +          if (T.isNull()) +            break; + +          T = SemaRef.Context.getPackExpansionType(T, NumExpansions); +          Exceptions.push_back(T); +          continue; +        } + +        // Substitute into the pack expansion pattern for each template +        bool Invalid = false; +        for (unsigned ArgIdx = 0; ArgIdx != *NumExpansions; ++ArgIdx) { +          Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, ArgIdx); + +          QualType T = SemaRef.SubstType(PackExpansion->getPattern(), +                                         TemplateArgs, +                                       New->getLocation(), New->getDeclName()); +          if (T.isNull()) { +            Invalid = true; +            break; +          } + +          Exceptions.push_back(T); +        } + +        if (Invalid) +          break; + +        continue; +      } + +      QualType T +        = SemaRef.SubstType(Proto->getExceptionType(I), TemplateArgs, +                            New->getLocation(), New->getDeclName()); +      if (T.isNull() || +          SemaRef.CheckSpecifiedExceptionType(T, New->getLocation())) +        continue; + +      Exceptions.push_back(T); +    } +    Expr *NoexceptExpr = 0; +    if (Expr *OldNoexceptExpr = Proto->getNoexceptExpr()) { +      EnterExpressionEvaluationContext Unevaluated(SemaRef, +                                                   Sema::ConstantEvaluated); +      ExprResult E = SemaRef.SubstExpr(OldNoexceptExpr, TemplateArgs); +      if (E.isUsable()) +        E = SemaRef.CheckBooleanCondition(E.get(), E.get()->getLocStart()); + +      if (E.isUsable()) { +        NoexceptExpr = E.take(); +        if (!NoexceptExpr->isTypeDependent() && +            !NoexceptExpr->isValueDependent()) +          NoexceptExpr = SemaRef.VerifyIntegerConstantExpression(NoexceptExpr, +            0, SemaRef.PDiag(diag::err_noexcept_needs_constant_expression), +            /*AllowFold*/ false).take(); +      } +    } + +    // Rebuild the function type + +    FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo(); +    EPI.ExceptionSpecType = Proto->getExceptionSpecType(); +    EPI.NumExceptions = Exceptions.size(); +    EPI.Exceptions = Exceptions.data(); +    EPI.NoexceptExpr = NoexceptExpr; +    EPI.ExtInfo = Proto->getExtInfo(); + +    const FunctionProtoType *NewProto +      = New->getType()->getAs<FunctionProtoType>(); +    assert(NewProto && "Template instantiation without function prototype?"); +    New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(), +                                                 NewProto->arg_type_begin(), +                                                 NewProto->getNumArgs(), +                                                 EPI)); +  } + +  const FunctionDecl* Definition = Tmpl; + +  // Get the definition. Leaves the variable unchanged if undefined. +  Tmpl->isDefined(Definition); + +  SemaRef.InstantiateAttrs(TemplateArgs, Definition, New, +                           LateAttrs, StartingScope); + +  return false; +} + +/// \brief Initializes common fields of an instantiated method +/// declaration (New) from the corresponding fields of its template +/// (Tmpl). +/// +/// \returns true if there was an error +bool +TemplateDeclInstantiator::InitMethodInstantiation(CXXMethodDecl *New, +                                                  CXXMethodDecl *Tmpl) { +  if (InitFunctionInstantiation(New, Tmpl)) +    return true; + +  New->setAccess(Tmpl->getAccess()); +  if (Tmpl->isVirtualAsWritten()) +    New->setVirtualAsWritten(true); + +  // FIXME: attributes +  // FIXME: New needs a pointer to Tmpl +  return false; +} + +/// \brief Instantiate the definition of the given function from its +/// template. +/// +/// \param PointOfInstantiation the point at which the instantiation was +/// required. Note that this is not precisely a "point of instantiation" +/// for the function, but it's close. +/// +/// \param Function the already-instantiated declaration of a +/// function template specialization or member function of a class template +/// specialization. +/// +/// \param Recursive if true, recursively instantiates any functions that +/// are required by this instantiation. +/// +/// \param DefinitionRequired if true, then we are performing an explicit +/// instantiation where the body of the function is required. Complain if +/// there is no such body. +void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation, +                                         FunctionDecl *Function, +                                         bool Recursive, +                                         bool DefinitionRequired) { +  if (Function->isInvalidDecl() || Function->isDefined()) +    return; + +  // Never instantiate an explicit specialization except if it is a class scope +  // explicit specialization. +  if (Function->getTemplateSpecializationKind() == TSK_ExplicitSpecialization && +      !Function->getClassScopeSpecializationPattern()) +    return; + +  // Find the function body that we'll be substituting. +  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern(); +  assert(PatternDecl && "instantiating a non-template"); + +  Stmt *Pattern = PatternDecl->getBody(PatternDecl); +  assert(PatternDecl && "template definition is not a template"); +  if (!Pattern) { +    // Try to find a defaulted definition +    PatternDecl->isDefined(PatternDecl); +  } +  assert(PatternDecl && "template definition is not a template"); + +  // Postpone late parsed template instantiations. +  if (PatternDecl->isLateTemplateParsed() && +      !LateTemplateParser) { +    PendingInstantiations.push_back( +      std::make_pair(Function, PointOfInstantiation)); +    return; +  } + +  // Call the LateTemplateParser callback if there a need to late parse +  // a templated function definition. +  if (!Pattern && PatternDecl->isLateTemplateParsed() && +      LateTemplateParser) { +    LateTemplateParser(OpaqueParser, PatternDecl); +    Pattern = PatternDecl->getBody(PatternDecl); +  } + +  if (!Pattern && !PatternDecl->isDefaulted()) { +    if (DefinitionRequired) { +      if (Function->getPrimaryTemplate()) +        Diag(PointOfInstantiation, +             diag::err_explicit_instantiation_undefined_func_template) +          << Function->getPrimaryTemplate(); +      else +        Diag(PointOfInstantiation, +             diag::err_explicit_instantiation_undefined_member) +          << 1 << Function->getDeclName() << Function->getDeclContext(); + +      if (PatternDecl) +        Diag(PatternDecl->getLocation(), +             diag::note_explicit_instantiation_here); +      Function->setInvalidDecl(); +    } else if (Function->getTemplateSpecializationKind() +                 == TSK_ExplicitInstantiationDefinition) { +      PendingInstantiations.push_back( +        std::make_pair(Function, PointOfInstantiation)); +    } + +    return; +  } + +  // C++0x [temp.explicit]p9: +  //   Except for inline functions, other explicit instantiation declarations +  //   have the effect of suppressing the implicit instantiation of the entity +  //   to which they refer. +  if (Function->getTemplateSpecializationKind() +        == TSK_ExplicitInstantiationDeclaration && +      !PatternDecl->isInlined()) +    return; + +  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function); +  if (Inst) +    return; + +  // Copy the inner loc start from the pattern. +  Function->setInnerLocStart(PatternDecl->getInnerLocStart()); + +  // If we're performing recursive template instantiation, create our own +  // queue of pending implicit instantiations that we will instantiate later, +  // while we're still within our own instantiation context. +  SmallVector<VTableUse, 16> SavedVTableUses; +  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations; +  if (Recursive) { +    VTableUses.swap(SavedVTableUses); +    PendingInstantiations.swap(SavedPendingInstantiations); +  } + +  EnterExpressionEvaluationContext EvalContext(*this, +                                               Sema::PotentiallyEvaluated); +  ActOnStartOfFunctionDef(0, Function); + +  // Introduce a new scope where local variable instantiations will be +  // recorded, unless we're actually a member function within a local +  // class, in which case we need to merge our results with the parent +  // scope (of the enclosing function). +  bool MergeWithParentScope = false; +  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext())) +    MergeWithParentScope = Rec->isLocalClass(); + +  LocalInstantiationScope Scope(*this, MergeWithParentScope); + +  // Enter the scope of this instantiation. We don't use +  // PushDeclContext because we don't have a scope. +  Sema::ContextRAII savedContext(*this, Function); + +  MultiLevelTemplateArgumentList TemplateArgs = +    getTemplateInstantiationArgs(Function, 0, false, PatternDecl); + +  // Introduce the instantiated function parameters into the local +  // instantiation scope, and set the parameter names to those used +  // in the template. +  unsigned FParamIdx = 0; +  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) { +    const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I); +    if (!PatternParam->isParameterPack()) { +      // Simple case: not a parameter pack. +      assert(FParamIdx < Function->getNumParams()); +      ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx); +      FunctionParam->setDeclName(PatternParam->getDeclName()); +      Scope.InstantiatedLocal(PatternParam, FunctionParam); +      ++FParamIdx; +      continue; +    } + +    // Expand the parameter pack. +    Scope.MakeInstantiatedLocalArgPack(PatternParam); +    unsigned NumArgumentsInExpansion +      = getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs); +    for (unsigned Arg = 0; Arg < NumArgumentsInExpansion; ++Arg) { +      ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx); +      FunctionParam->setDeclName(PatternParam->getDeclName()); +      Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam); +      ++FParamIdx; +    } +  } + +  if (PatternDecl->isDefaulted()) { +    ActOnFinishFunctionBody(Function, 0, /*IsInstantiation=*/true); + +    SetDeclDefaulted(Function, PatternDecl->getLocation()); +  } else { +    // If this is a constructor, instantiate the member initializers. +    if (const CXXConstructorDecl *Ctor = +          dyn_cast<CXXConstructorDecl>(PatternDecl)) { +      InstantiateMemInitializers(cast<CXXConstructorDecl>(Function), Ctor, +                                 TemplateArgs); +    } + +    // Instantiate the function body. +    StmtResult Body = SubstStmt(Pattern, TemplateArgs); + +    if (Body.isInvalid()) +      Function->setInvalidDecl(); + +    ActOnFinishFunctionBody(Function, Body.get(), +                            /*IsInstantiation=*/true); +  } + +  PerformDependentDiagnostics(PatternDecl, TemplateArgs); + +  savedContext.pop(); + +  DeclGroupRef DG(Function); +  Consumer.HandleTopLevelDecl(DG); + +  // This class may have local implicit instantiations that need to be +  // instantiation within this scope. +  PerformPendingInstantiations(/*LocalOnly=*/true); +  Scope.Exit(); + +  if (Recursive) { +    // Define any pending vtables. +    DefineUsedVTables(); + +    // Instantiate any pending implicit instantiations found during the +    // instantiation of this template. +    PerformPendingInstantiations(); + +    // Restore the set of pending vtables. +    assert(VTableUses.empty() && +           "VTableUses should be empty before it is discarded."); +    VTableUses.swap(SavedVTableUses); + +    // Restore the set of pending implicit instantiations. +    assert(PendingInstantiations.empty() && +           "PendingInstantiations should be empty before it is discarded."); +    PendingInstantiations.swap(SavedPendingInstantiations); +  } +} + +/// \brief Instantiate the definition of the given variable from its +/// template. +/// +/// \param PointOfInstantiation the point at which the instantiation was +/// required. Note that this is not precisely a "point of instantiation" +/// for the function, but it's close. +/// +/// \param Var the already-instantiated declaration of a static member +/// variable of a class template specialization. +/// +/// \param Recursive if true, recursively instantiates any functions that +/// are required by this instantiation. +/// +/// \param DefinitionRequired if true, then we are performing an explicit +/// instantiation where an out-of-line definition of the member variable +/// is required. Complain if there is no such definition. +void Sema::InstantiateStaticDataMemberDefinition( +                                          SourceLocation PointOfInstantiation, +                                                 VarDecl *Var, +                                                 bool Recursive, +                                                 bool DefinitionRequired) { +  if (Var->isInvalidDecl()) +    return; + +  // Find the out-of-line definition of this static data member. +  VarDecl *Def = Var->getInstantiatedFromStaticDataMember(); +  assert(Def && "This data member was not instantiated from a template?"); +  assert(Def->isStaticDataMember() && "Not a static data member?"); +  Def = Def->getOutOfLineDefinition(); + +  if (!Def) { +    // We did not find an out-of-line definition of this static data member, +    // so we won't perform any instantiation. Rather, we rely on the user to +    // instantiate this definition (or provide a specialization for it) in +    // another translation unit. +    if (DefinitionRequired) { +      Def = Var->getInstantiatedFromStaticDataMember(); +      Diag(PointOfInstantiation, +           diag::err_explicit_instantiation_undefined_member) +        << 2 << Var->getDeclName() << Var->getDeclContext(); +      Diag(Def->getLocation(), diag::note_explicit_instantiation_here); +    } else if (Var->getTemplateSpecializationKind() +                 == TSK_ExplicitInstantiationDefinition) { +      PendingInstantiations.push_back( +        std::make_pair(Var, PointOfInstantiation)); +    } + +    return; +  } + +  TemplateSpecializationKind TSK = Var->getTemplateSpecializationKind(); + +  // Never instantiate an explicit specialization. +  if (TSK == TSK_ExplicitSpecialization) +    return; + +  // C++0x [temp.explicit]p9: +  //   Except for inline functions, other explicit instantiation declarations +  //   have the effect of suppressing the implicit instantiation of the entity +  //   to which they refer. +  if (TSK == TSK_ExplicitInstantiationDeclaration) +    return; + +  Consumer.HandleCXXStaticMemberVarInstantiation(Var); + +  // If we already have a definition, we're done. +  if (VarDecl *Def = Var->getDefinition()) { +    // We may be explicitly instantiating something we've already implicitly +    // instantiated. +    Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(), +                                       PointOfInstantiation); +    return; +  } + +  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var); +  if (Inst) +    return; + +  // If we're performing recursive template instantiation, create our own +  // queue of pending implicit instantiations that we will instantiate later, +  // while we're still within our own instantiation context. +  SmallVector<VTableUse, 16> SavedVTableUses; +  std::deque<PendingImplicitInstantiation> SavedPendingInstantiations; +  if (Recursive) { +    VTableUses.swap(SavedVTableUses); +    PendingInstantiations.swap(SavedPendingInstantiations); +  } + +  // Enter the scope of this instantiation. We don't use +  // PushDeclContext because we don't have a scope. +  ContextRAII previousContext(*this, Var->getDeclContext()); +  LocalInstantiationScope Local(*this); +   +  VarDecl *OldVar = Var; +  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(), +                                        getTemplateInstantiationArgs(Var))); + +  previousContext.pop(); + +  if (Var) { +    MemberSpecializationInfo *MSInfo = OldVar->getMemberSpecializationInfo(); +    assert(MSInfo && "Missing member specialization information?"); +    Var->setTemplateSpecializationKind(MSInfo->getTemplateSpecializationKind(), +                                       MSInfo->getPointOfInstantiation()); +    DeclGroupRef DG(Var); +    Consumer.HandleTopLevelDecl(DG); +  } +  Local.Exit(); +   +  if (Recursive) { +    // Define any newly required vtables. +    DefineUsedVTables(); + +    // Instantiate any pending implicit instantiations found during the +    // instantiation of this template. +    PerformPendingInstantiations(); + +    // Restore the set of pending vtables. +    assert(VTableUses.empty() && +           "VTableUses should be empty before it is discarded, " +           "while instantiating static data member."); +    VTableUses.swap(SavedVTableUses); + +    // Restore the set of pending implicit instantiations. +    assert(PendingInstantiations.empty() && +           "PendingInstantiations should be empty before it is discarded, " +           "while instantiating static data member."); +    PendingInstantiations.swap(SavedPendingInstantiations); +  } +} + +void +Sema::InstantiateMemInitializers(CXXConstructorDecl *New, +                                 const CXXConstructorDecl *Tmpl, +                           const MultiLevelTemplateArgumentList &TemplateArgs) { + +  SmallVector<CXXCtorInitializer*, 4> NewInits; +  bool AnyErrors = false; + +  // Instantiate all the initializers. +  for (CXXConstructorDecl::init_const_iterator Inits = Tmpl->init_begin(), +                                            InitsEnd = Tmpl->init_end(); +       Inits != InitsEnd; ++Inits) { +    CXXCtorInitializer *Init = *Inits; + +    // Only instantiate written initializers, let Sema re-construct implicit +    // ones. +    if (!Init->isWritten()) +      continue; + +    SourceLocation EllipsisLoc; + +    if (Init->isPackExpansion()) { +      // This is a pack expansion. We should expand it now. +      TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc(); +      SmallVector<UnexpandedParameterPack, 2> Unexpanded; +      collectUnexpandedParameterPacks(BaseTL, Unexpanded); +      bool ShouldExpand = false; +      bool RetainExpansion = false; +      llvm::Optional<unsigned> NumExpansions; +      if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(), +                                          BaseTL.getSourceRange(), +                                          Unexpanded, +                                          TemplateArgs, ShouldExpand, +                                          RetainExpansion, +                                          NumExpansions)) { +        AnyErrors = true; +        New->setInvalidDecl(); +        continue; +      } +      assert(ShouldExpand && "Partial instantiation of base initializer?"); + +      // Loop over all of the arguments in the argument pack(s), +      for (unsigned I = 0; I != *NumExpansions; ++I) { +        Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I); + +        // Instantiate the initializer. +        ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs, +                                               /*CXXDirectInit=*/true); +        if (TempInit.isInvalid()) { +          AnyErrors = true; +          break; +        } + +        // Instantiate the base type. +        TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(), +                                              TemplateArgs, +                                              Init->getSourceLocation(), +                                              New->getDeclName()); +        if (!BaseTInfo) { +          AnyErrors = true; +          break; +        } + +        // Build the initializer. +        MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(), +                                                     BaseTInfo, TempInit.take(), +                                                     New->getParent(), +                                                     SourceLocation()); +        if (NewInit.isInvalid()) { +          AnyErrors = true; +          break; +        } + +        NewInits.push_back(NewInit.get()); +      } + +      continue; +    } + +    // Instantiate the initializer. +    ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs, +                                           /*CXXDirectInit=*/true); +    if (TempInit.isInvalid()) { +      AnyErrors = true; +      continue; +    } + +    MemInitResult NewInit; +    if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) { +      TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(), +                                        TemplateArgs, +                                        Init->getSourceLocation(), +                                        New->getDeclName()); +      if (!TInfo) { +        AnyErrors = true; +        New->setInvalidDecl(); +        continue; +      } + +      if (Init->isBaseInitializer()) +        NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.take(), +                                       New->getParent(), EllipsisLoc); +      else +        NewInit = BuildDelegatingInitializer(TInfo, TempInit.take(), +                                  cast<CXXRecordDecl>(CurContext->getParent())); +    } else if (Init->isMemberInitializer()) { +      FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl( +                                                     Init->getMemberLocation(), +                                                     Init->getMember(), +                                                     TemplateArgs)); +      if (!Member) { +        AnyErrors = true; +        New->setInvalidDecl(); +        continue; +      } + +      NewInit = BuildMemberInitializer(Member, TempInit.take(), +                                       Init->getSourceLocation()); +    } else if (Init->isIndirectMemberInitializer()) { +      IndirectFieldDecl *IndirectMember = +         cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl( +                                 Init->getMemberLocation(), +                                 Init->getIndirectMember(), TemplateArgs)); + +      if (!IndirectMember) { +        AnyErrors = true; +        New->setInvalidDecl(); +        continue; +      } + +      NewInit = BuildMemberInitializer(IndirectMember, TempInit.take(), +                                       Init->getSourceLocation()); +    } + +    if (NewInit.isInvalid()) { +      AnyErrors = true; +      New->setInvalidDecl(); +    } else { +      NewInits.push_back(NewInit.get()); +    } +  } + +  // Assign all the initializers to the new constructor. +  ActOnMemInitializers(New, +                       /*FIXME: ColonLoc */ +                       SourceLocation(), +                       NewInits.data(), NewInits.size(), +                       AnyErrors); +} + +ExprResult Sema::SubstInitializer(Expr *Init, +                          const MultiLevelTemplateArgumentList &TemplateArgs, +                          bool CXXDirectInit) { +  // Initializers are instantiated like expressions, except that various outer +  // layers are stripped. +  if (!Init) +    return Owned(Init); + +  if (ExprWithCleanups *ExprTemp = dyn_cast<ExprWithCleanups>(Init)) +    Init = ExprTemp->getSubExpr(); + +  while (CXXBindTemporaryExpr *Binder = dyn_cast<CXXBindTemporaryExpr>(Init)) +    Init = Binder->getSubExpr(); + +  if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Init)) +    Init = ICE->getSubExprAsWritten(); + +  // If this is a direct-initializer, we take apart CXXConstructExprs. +  // Everything else is passed through. +  CXXConstructExpr *Construct; +  if (!CXXDirectInit || !(Construct = dyn_cast<CXXConstructExpr>(Init)) || +      isa<CXXTemporaryObjectExpr>(Construct)) +    return SubstExpr(Init, TemplateArgs); + +  ASTOwningVector<Expr*> NewArgs(*this); +  if (SubstExprs(Construct->getArgs(), Construct->getNumArgs(), true, +                 TemplateArgs, NewArgs)) +    return ExprError(); + +  // Treat an empty initializer like none. +  if (NewArgs.empty()) +    return Owned((Expr*)0); + +  // Build a ParenListExpr to represent anything else. +  // FIXME: Fake locations! +  SourceLocation Loc = PP.getLocForEndOfToken(Init->getLocStart()); +  return ActOnParenListExpr(Loc, Loc, move_arg(NewArgs)); +} + +// TODO: this could be templated if the various decl types used the +// same method name. +static bool isInstantiationOf(ClassTemplateDecl *Pattern, +                              ClassTemplateDecl *Instance) { +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromMemberTemplate(); +  } while (Instance); + +  return false; +} + +static bool isInstantiationOf(FunctionTemplateDecl *Pattern, +                              FunctionTemplateDecl *Instance) { +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromMemberTemplate(); +  } while (Instance); + +  return false; +} + +static bool +isInstantiationOf(ClassTemplatePartialSpecializationDecl *Pattern, +                  ClassTemplatePartialSpecializationDecl *Instance) { +  Pattern +    = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl()); +  do { +    Instance = cast<ClassTemplatePartialSpecializationDecl>( +                                                Instance->getCanonicalDecl()); +    if (Pattern == Instance) +      return true; +    Instance = Instance->getInstantiatedFromMember(); +  } while (Instance); + +  return false; +} + +static bool isInstantiationOf(CXXRecordDecl *Pattern, +                              CXXRecordDecl *Instance) { +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromMemberClass(); +  } while (Instance); + +  return false; +} + +static bool isInstantiationOf(FunctionDecl *Pattern, +                              FunctionDecl *Instance) { +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromMemberFunction(); +  } while (Instance); + +  return false; +} + +static bool isInstantiationOf(EnumDecl *Pattern, +                              EnumDecl *Instance) { +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromMemberEnum(); +  } while (Instance); + +  return false; +} + +static bool isInstantiationOf(UsingShadowDecl *Pattern, +                              UsingShadowDecl *Instance, +                              ASTContext &C) { +  return C.getInstantiatedFromUsingShadowDecl(Instance) == Pattern; +} + +static bool isInstantiationOf(UsingDecl *Pattern, +                              UsingDecl *Instance, +                              ASTContext &C) { +  return C.getInstantiatedFromUsingDecl(Instance) == Pattern; +} + +static bool isInstantiationOf(UnresolvedUsingValueDecl *Pattern, +                              UsingDecl *Instance, +                              ASTContext &C) { +  return C.getInstantiatedFromUsingDecl(Instance) == Pattern; +} + +static bool isInstantiationOf(UnresolvedUsingTypenameDecl *Pattern, +                              UsingDecl *Instance, +                              ASTContext &C) { +  return C.getInstantiatedFromUsingDecl(Instance) == Pattern; +} + +static bool isInstantiationOfStaticDataMember(VarDecl *Pattern, +                                              VarDecl *Instance) { +  assert(Instance->isStaticDataMember()); + +  Pattern = Pattern->getCanonicalDecl(); + +  do { +    Instance = Instance->getCanonicalDecl(); +    if (Pattern == Instance) return true; +    Instance = Instance->getInstantiatedFromStaticDataMember(); +  } while (Instance); + +  return false; +} + +// Other is the prospective instantiation +// D is the prospective pattern +static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) { +  if (D->getKind() != Other->getKind()) { +    if (UnresolvedUsingTypenameDecl *UUD +          = dyn_cast<UnresolvedUsingTypenameDecl>(D)) { +      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) { +        return isInstantiationOf(UUD, UD, Ctx); +      } +    } + +    if (UnresolvedUsingValueDecl *UUD +          = dyn_cast<UnresolvedUsingValueDecl>(D)) { +      if (UsingDecl *UD = dyn_cast<UsingDecl>(Other)) { +        return isInstantiationOf(UUD, UD, Ctx); +      } +    } + +    return false; +  } + +  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Other)) +    return isInstantiationOf(cast<CXXRecordDecl>(D), Record); + +  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Other)) +    return isInstantiationOf(cast<FunctionDecl>(D), Function); + +  if (EnumDecl *Enum = dyn_cast<EnumDecl>(Other)) +    return isInstantiationOf(cast<EnumDecl>(D), Enum); + +  if (VarDecl *Var = dyn_cast<VarDecl>(Other)) +    if (Var->isStaticDataMember()) +      return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var); + +  if (ClassTemplateDecl *Temp = dyn_cast<ClassTemplateDecl>(Other)) +    return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp); + +  if (FunctionTemplateDecl *Temp = dyn_cast<FunctionTemplateDecl>(Other)) +    return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp); + +  if (ClassTemplatePartialSpecializationDecl *PartialSpec +        = dyn_cast<ClassTemplatePartialSpecializationDecl>(Other)) +    return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D), +                             PartialSpec); + +  if (FieldDecl *Field = dyn_cast<FieldDecl>(Other)) { +    if (!Field->getDeclName()) { +      // This is an unnamed field. +      return Ctx.getInstantiatedFromUnnamedFieldDecl(Field) == +        cast<FieldDecl>(D); +    } +  } + +  if (UsingDecl *Using = dyn_cast<UsingDecl>(Other)) +    return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx); + +  if (UsingShadowDecl *Shadow = dyn_cast<UsingShadowDecl>(Other)) +    return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx); + +  return D->getDeclName() && isa<NamedDecl>(Other) && +    D->getDeclName() == cast<NamedDecl>(Other)->getDeclName(); +} + +template<typename ForwardIterator> +static NamedDecl *findInstantiationOf(ASTContext &Ctx, +                                      NamedDecl *D, +                                      ForwardIterator first, +                                      ForwardIterator last) { +  for (; first != last; ++first) +    if (isInstantiationOf(Ctx, D, *first)) +      return cast<NamedDecl>(*first); + +  return 0; +} + +/// \brief Finds the instantiation of the given declaration context +/// within the current instantiation. +/// +/// \returns NULL if there was an error +DeclContext *Sema::FindInstantiatedContext(SourceLocation Loc, DeclContext* DC, +                          const MultiLevelTemplateArgumentList &TemplateArgs) { +  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) { +    Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs); +    return cast_or_null<DeclContext>(ID); +  } else return DC; +} + +/// \brief Find the instantiation of the given declaration within the +/// current instantiation. +/// +/// This routine is intended to be used when \p D is a declaration +/// referenced from within a template, that needs to mapped into the +/// corresponding declaration within an instantiation. For example, +/// given: +/// +/// \code +/// template<typename T> +/// struct X { +///   enum Kind { +///     KnownValue = sizeof(T) +///   }; +/// +///   bool getKind() const { return KnownValue; } +/// }; +/// +/// template struct X<int>; +/// \endcode +/// +/// In the instantiation of X<int>::getKind(), we need to map the +/// EnumConstantDecl for KnownValue (which refers to +/// X<T>::<Kind>::KnownValue) to its instantiation +/// (X<int>::<Kind>::KnownValue). InstantiateCurrentDeclRef() performs +/// this mapping from within the instantiation of X<int>. +NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D, +                          const MultiLevelTemplateArgumentList &TemplateArgs) { +  DeclContext *ParentDC = D->getDeclContext(); +  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) || +      isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) || +      (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) || +      (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) { +    // D is a local of some kind. Look into the map of local +    // declarations to their instantiations. +    typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack; +    llvm::PointerUnion<Decl *, DeclArgumentPack *> *Found +      = CurrentInstantiationScope->findInstantiationOf(D); + +    if (Found) { +      if (Decl *FD = Found->dyn_cast<Decl *>()) +        return cast<NamedDecl>(FD); + +      unsigned PackIdx = ArgumentPackSubstitutionIndex; +      return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]); +    } + +    // If we didn't find the decl, then we must have a label decl that hasn't +    // been found yet.  Lazily instantiate it and return it now. +    assert(isa<LabelDecl>(D)); + +    Decl *Inst = SubstDecl(D, CurContext, TemplateArgs); +    assert(Inst && "Failed to instantiate label??"); + +    CurrentInstantiationScope->InstantiatedLocal(D, Inst); +    return cast<LabelDecl>(Inst); +  } + +  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) { +    if (!Record->isDependentContext()) +      return D; + +    // Determine whether this record is the "templated" declaration describing +    // a class template or class template partial specialization. +    ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate(); +    if (ClassTemplate) +      ClassTemplate = ClassTemplate->getCanonicalDecl(); +    else if (ClassTemplatePartialSpecializationDecl *PartialSpec +               = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) +      ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl(); +     +    // Walk the current context to find either the record or an instantiation of +    // it. +    DeclContext *DC = CurContext; +    while (!DC->isFileContext()) { +      // If we're performing substitution while we're inside the template +      // definition, we'll find our own context. We're done. +      if (DC->Equals(Record)) +        return Record; +       +      if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) { +        // Check whether we're in the process of instantiating a class template +        // specialization of the template we're mapping. +        if (ClassTemplateSpecializationDecl *InstSpec +                      = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){ +          ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate(); +          if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate)) +            return InstRecord; +        } +       +        // Check whether we're in the process of instantiating a member class. +        if (isInstantiationOf(Record, InstRecord)) +          return InstRecord; +      } +       +       +      // Move to the outer template scope. +      if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) { +        if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){ +          DC = FD->getLexicalDeclContext(); +          continue; +        } +      } +       +      DC = DC->getParent(); +    } + +    // Fall through to deal with other dependent record types (e.g., +    // anonymous unions in class templates). +  } + +  if (!ParentDC->isDependentContext()) +    return D; + +  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs); +  if (!ParentDC) +    return 0; + +  if (ParentDC != D->getDeclContext()) { +    // We performed some kind of instantiation in the parent context, +    // so now we need to look into the instantiated parent context to +    // find the instantiation of the declaration D. + +    // If our context used to be dependent, we may need to instantiate +    // it before performing lookup into that context. +    bool IsBeingInstantiated = false; +    if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) { +      if (!Spec->isDependentContext()) { +        QualType T = Context.getTypeDeclType(Spec); +        const RecordType *Tag = T->getAs<RecordType>(); +        assert(Tag && "type of non-dependent record is not a RecordType"); +        if (Tag->isBeingDefined()) +          IsBeingInstantiated = true; +        if (!Tag->isBeingDefined() && +            RequireCompleteType(Loc, T, diag::err_incomplete_type)) +          return 0; + +        ParentDC = Tag->getDecl(); +      } +    } + +    NamedDecl *Result = 0; +    if (D->getDeclName()) { +      DeclContext::lookup_result Found = ParentDC->lookup(D->getDeclName()); +      Result = findInstantiationOf(Context, D, Found.first, Found.second); +    } else { +      // Since we don't have a name for the entity we're looking for, +      // our only option is to walk through all of the declarations to +      // find that name. This will occur in a few cases: +      // +      //   - anonymous struct/union within a template +      //   - unnamed class/struct/union/enum within a template +      // +      // FIXME: Find a better way to find these instantiations! +      Result = findInstantiationOf(Context, D, +                                   ParentDC->decls_begin(), +                                   ParentDC->decls_end()); +    } + +    if (!Result) { +      if (isa<UsingShadowDecl>(D)) { +        // UsingShadowDecls can instantiate to nothing because of using hiding. +      } else if (Diags.hasErrorOccurred()) { +        // We've already complained about something, so most likely this +        // declaration failed to instantiate. There's no point in complaining +        // further, since this is normal in invalid code. +      } else if (IsBeingInstantiated) { +        // The class in which this member exists is currently being +        // instantiated, and we haven't gotten around to instantiating this +        // member yet. This can happen when the code uses forward declarations +        // of member classes, and introduces ordering dependencies via +        // template instantiation. +        Diag(Loc, diag::err_member_not_yet_instantiated) +          << D->getDeclName() +          << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC)); +        Diag(D->getLocation(), diag::note_non_instantiated_member_here); +      } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) { +        // This enumeration constant was found when the template was defined, +        // but can't be found in the instantiation. This can happen if an +        // unscoped enumeration member is explicitly specialized. +        EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext()); +        EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum, +                                                             TemplateArgs)); +        assert(Spec->getTemplateSpecializationKind() == +                 TSK_ExplicitSpecialization); +        Diag(Loc, diag::err_enumerator_does_not_exist) +          << D->getDeclName() +          << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext())); +        Diag(Spec->getLocation(), diag::note_enum_specialized_here) +          << Context.getTypeDeclType(Spec); +      } else { +        // We should have found something, but didn't. +        llvm_unreachable("Unable to find instantiation of declaration!"); +      } +    } + +    D = Result; +  } + +  return D; +} + +/// \brief Performs template instantiation for all implicit template +/// instantiations we have seen until this point. +void Sema::PerformPendingInstantiations(bool LocalOnly) { +  // Load pending instantiations from the external source. +  if (!LocalOnly && ExternalSource) { +    SmallVector<std::pair<ValueDecl *, SourceLocation>, 4> Pending; +    ExternalSource->ReadPendingInstantiations(Pending); +    PendingInstantiations.insert(PendingInstantiations.begin(), +                                 Pending.begin(), Pending.end()); +  } + +  while (!PendingLocalImplicitInstantiations.empty() || +         (!LocalOnly && !PendingInstantiations.empty())) { +    PendingImplicitInstantiation Inst; + +    if (PendingLocalImplicitInstantiations.empty()) { +      Inst = PendingInstantiations.front(); +      PendingInstantiations.pop_front(); +    } else { +      Inst = PendingLocalImplicitInstantiations.front(); +      PendingLocalImplicitInstantiations.pop_front(); +    } + +    // Instantiate function definitions +    if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) { +      PrettyDeclStackTraceEntry CrashInfo(*this, Function, SourceLocation(), +                                          "instantiating function definition"); +      bool DefinitionRequired = Function->getTemplateSpecializationKind() == +                                TSK_ExplicitInstantiationDefinition; +      InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true, +                                    DefinitionRequired); +      continue; +    } + +    // Instantiate static data member definitions. +    VarDecl *Var = cast<VarDecl>(Inst.first); +    assert(Var->isStaticDataMember() && "Not a static data member?"); + +    // Don't try to instantiate declarations if the most recent redeclaration +    // is invalid. +    if (Var->getMostRecentDecl()->isInvalidDecl()) +      continue; + +    // Check if the most recent declaration has changed the specialization kind +    // and removed the need for implicit instantiation. +    switch (Var->getMostRecentDecl()->getTemplateSpecializationKind()) { +    case TSK_Undeclared: +      llvm_unreachable("Cannot instantitiate an undeclared specialization."); +    case TSK_ExplicitInstantiationDeclaration: +    case TSK_ExplicitSpecialization: +      continue;  // No longer need to instantiate this type. +    case TSK_ExplicitInstantiationDefinition: +      // We only need an instantiation if the pending instantiation *is* the +      // explicit instantiation. +      if (Var != Var->getMostRecentDecl()) continue; +    case TSK_ImplicitInstantiation: +      break; +    } + +    PrettyDeclStackTraceEntry CrashInfo(*this, Var, Var->getLocation(), +                                        "instantiating static data member " +                                        "definition"); + +    bool DefinitionRequired = Var->getTemplateSpecializationKind() == +                              TSK_ExplicitInstantiationDefinition; +    InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true, +                                          DefinitionRequired); +  } +} + +void Sema::PerformDependentDiagnostics(const DeclContext *Pattern, +                       const MultiLevelTemplateArgumentList &TemplateArgs) { +  for (DeclContext::ddiag_iterator I = Pattern->ddiag_begin(), +         E = Pattern->ddiag_end(); I != E; ++I) { +    DependentDiagnostic *DD = *I; + +    switch (DD->getKind()) { +    case DependentDiagnostic::Access: +      HandleDependentAccessCheck(*DD, TemplateArgs); +      break; +    } +  } +}  | 
