Add the clang library to the repo (with some of my changes, too).

1 files changed, 3502 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
new file mode 100644
index 0000000..c7bd99c
--- /dev/null
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -0,0 +1,3502 @@
+//===--- 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");
+  
+  CXXRecordDecl *ThisContext = 0;
+  unsigned ThisTypeQuals = 0;
+  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
+    ThisContext = Method->getParent();
+    ThisTypeQuals = Method->getTypeQualifiers();
+  }
+  
+  TypeSourceInfo *NewTInfo
+    = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
+                                    D->getTypeSpecStartLoc(),
+                                    D->getDeclName(),
+                                    ThisContext, ThisTypeQuals);
+  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;
+}
+
+/// Introduce the instantiated function parameters into the local
+/// instantiation scope, and set the parameter names to those used
+/// in the template.
+static void addInstantiatedParametersToScope(Sema &S, FunctionDecl *Function,
+                                             const FunctionDecl *PatternDecl,
+                                             LocalInstantiationScope &Scope,
+                           const MultiLevelTemplateArgumentList &TemplateArgs) {
+  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
+      = S.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;
+    }
+  }
+}
+
+static void InstantiateExceptionSpec(Sema &SemaRef, FunctionDecl *New,
+                                     const FunctionProtoType *Proto,
+                           const MultiLevelTemplateArgumentList &TemplateArgs) {
+  assert(Proto->getExceptionSpecType() != EST_Uninstantiated);
+
+  // C++11 [expr.prim.general]p3:
+  //   If a declaration declares a member function or member function 
+  //   template of a class X, the expression this is a prvalue of type 
+  //   "pointer to cv-qualifier-seq X" between the optional cv-qualifer-seq
+  //   and the end of the function-definition, member-declarator, or 
+  //   declarator.    
+  CXXRecordDecl *ThisContext = 0;
+  unsigned ThisTypeQuals = 0;
+  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(New)) {
+    ThisContext = Method->getParent();
+    ThisTypeQuals = Method->getTypeQualifiers();
+  }
+  Sema::CXXThisScopeRAII ThisScope(SemaRef, ThisContext, ThisTypeQuals,
+                                   SemaRef.getLangOpts().CPlusPlus0x);
+
+  // 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
+  const FunctionProtoType *NewProto
+    = New->getType()->getAs<FunctionProtoType>();
+  assert(NewProto && "Template instantiation without function prototype?");
+
+  FunctionProtoType::ExtProtoInfo EPI = NewProto->getExtProtoInfo();
+  EPI.ExceptionSpecType = Proto->getExceptionSpecType();
+  EPI.NumExceptions = Exceptions.size();
+  EPI.Exceptions = Exceptions.data();
+  EPI.NoexceptExpr = NoexceptExpr;
+
+  New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
+                                               NewProto->arg_type_begin(),
+                                               NewProto->getNumArgs(),
+                                               EPI));
+}
+
+void Sema::InstantiateExceptionSpec(SourceLocation PointOfInstantiation,
+                                    FunctionDecl *Decl) {
+  const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
+  if (Proto->getExceptionSpecType() != EST_Uninstantiated)
+    return;
+
+  InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
+                             InstantiatingTemplate::ExceptionSpecification());
+  if (Inst)
+    return;
+
+  // Enter the scope of this instantiation. We don't use
+  // PushDeclContext because we don't have a scope.
+  Sema::ContextRAII savedContext(*this, Decl);
+  LocalInstantiationScope Scope(*this);
+
+  MultiLevelTemplateArgumentList TemplateArgs =
+    getTemplateInstantiationArgs(Decl, 0, /*RelativeToPrimary*/true);
+
+  FunctionDecl *Template = Proto->getExceptionSpecTemplate();
+  addInstantiatedParametersToScope(*this, Decl, Template, Scope, TemplateArgs);
+
+  ::InstantiateExceptionSpec(*this, Decl,
+                             Template->getType()->castAs<FunctionProtoType>(),
+                             TemplateArgs);
+}
+
+/// \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()) {
+    FunctionProtoType::ExtProtoInfo EPI = Proto->getExtProtoInfo();
+
+    // DR1330: In C++11, defer instantiation of a non-trivial
+    // exception specification.
+    if (SemaRef.getLangOpts().CPlusPlus0x &&
+        EPI.ExceptionSpecType != EST_None &&
+        EPI.ExceptionSpecType != EST_DynamicNone &&
+        EPI.ExceptionSpecType != EST_BasicNoexcept) {
+      FunctionDecl *ExceptionSpecTemplate = Tmpl;
+      if (EPI.ExceptionSpecType == EST_Uninstantiated)
+        ExceptionSpecTemplate = EPI.ExceptionSpecTemplate;
+
+      // Mark the function has having an uninstantiated exception specification.
+      const FunctionProtoType *NewProto
+        = New->getType()->getAs<FunctionProtoType>();
+      assert(NewProto && "Template instantiation without function prototype?");
+      EPI = NewProto->getExtProtoInfo();
+      EPI.ExceptionSpecType = EST_Uninstantiated;
+      EPI.ExceptionSpecDecl = New;
+      EPI.ExceptionSpecTemplate = ExceptionSpecTemplate;
+      New->setType(SemaRef.Context.getFunctionType(NewProto->getResultType(),
+                                                   NewProto->arg_type_begin(),
+                                                   NewProto->getNumArgs(),
+                                                   EPI));
+    } else {
+      ::InstantiateExceptionSpec(SemaRef, New, Proto, TemplateArgs);
+    }
+  }
+
+  // Get the definition. Leaves the variable unchanged if undefined.
+  const FunctionDecl *Definition = Tmpl;
+  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);
+
+  addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
+                                   TemplateArgs);
+
+  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;
+    }
+  }
+}