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

1 files changed, 7192 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
new file mode 100644
index 0000000..51ce2a1
--- /dev/null
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -0,0 +1,7192 @@
+//===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===/
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//===----------------------------------------------------------------------===/
+//
+//  This file implements semantic analysis for C++ templates.
+//===----------------------------------------------------------------------===/
+
+#include "clang/Sema/SemaInternal.h"
+#include "clang/Sema/Lookup.h"
+#include "clang/Sema/Scope.h"
+#include "clang/Sema/Template.h"
+#include "clang/Sema/TemplateDeduction.h"
+#include "TreeTransform.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/Expr.h"
+#include "clang/AST/ExprCXX.h"
+#include "clang/AST/DeclFriend.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/TypeVisitor.h"
+#include "clang/Sema/DeclSpec.h"
+#include "clang/Sema/ParsedTemplate.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "llvm/ADT/SmallBitVector.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+using namespace clang;
+using namespace sema;
+
+// Exported for use by Parser.
+SourceRange
+clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
+                              unsigned N) {
+  if (!N) return SourceRange();
+  return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
+}
+
+/// \brief Determine whether the declaration found is acceptable as the name
+/// of a template and, if so, return that template declaration. Otherwise,
+/// returns NULL.
+static NamedDecl *isAcceptableTemplateName(ASTContext &Context,
+                                           NamedDecl *Orig,
+                                           bool AllowFunctionTemplates) {
+  NamedDecl *D = Orig->getUnderlyingDecl();
+
+  if (isa<TemplateDecl>(D)) {
+    if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D))
+      return 0;
+    
+    return Orig;
+  }
+
+  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
+    // C++ [temp.local]p1:
+    //   Like normal (non-template) classes, class templates have an
+    //   injected-class-name (Clause 9). The injected-class-name
+    //   can be used with or without a template-argument-list. When
+    //   it is used without a template-argument-list, it is
+    //   equivalent to the injected-class-name followed by the
+    //   template-parameters of the class template enclosed in
+    //   <>. When it is used with a template-argument-list, it
+    //   refers to the specified class template specialization,
+    //   which could be the current specialization or another
+    //   specialization.
+    if (Record->isInjectedClassName()) {
+      Record = cast<CXXRecordDecl>(Record->getDeclContext());
+      if (Record->getDescribedClassTemplate())
+        return Record->getDescribedClassTemplate();
+
+      if (ClassTemplateSpecializationDecl *Spec
+            = dyn_cast<ClassTemplateSpecializationDecl>(Record))
+        return Spec->getSpecializedTemplate();
+    }
+
+    return 0;
+  }
+
+  return 0;
+}
+
+void Sema::FilterAcceptableTemplateNames(LookupResult &R, 
+                                         bool AllowFunctionTemplates) {
+  // The set of class templates we've already seen.
+  llvm::SmallPtrSet<ClassTemplateDecl *, 8> ClassTemplates;
+  LookupResult::Filter filter = R.makeFilter();
+  while (filter.hasNext()) {
+    NamedDecl *Orig = filter.next();
+    NamedDecl *Repl = isAcceptableTemplateName(Context, Orig, 
+                                               AllowFunctionTemplates);
+    if (!Repl)
+      filter.erase();
+    else if (Repl != Orig) {
+
+      // C++ [temp.local]p3:
+      //   A lookup that finds an injected-class-name (10.2) can result in an
+      //   ambiguity in certain cases (for example, if it is found in more than
+      //   one base class). If all of the injected-class-names that are found
+      //   refer to specializations of the same class template, and if the name
+      //   is used as a template-name, the reference refers to the class
+      //   template itself and not a specialization thereof, and is not
+      //   ambiguous.
+      if (ClassTemplateDecl *ClassTmpl = dyn_cast<ClassTemplateDecl>(Repl))
+        if (!ClassTemplates.insert(ClassTmpl)) {
+          filter.erase();
+          continue;
+        }
+
+      // FIXME: we promote access to public here as a workaround to
+      // the fact that LookupResult doesn't let us remember that we
+      // found this template through a particular injected class name,
+      // which means we end up doing nasty things to the invariants.
+      // Pretending that access is public is *much* safer.
+      filter.replace(Repl, AS_public);
+    }
+  }
+  filter.done();
+}
+
+bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
+                                         bool AllowFunctionTemplates) {
+  for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I)
+    if (isAcceptableTemplateName(Context, *I, AllowFunctionTemplates))
+      return true;
+  
+  return false;
+}
+
+TemplateNameKind Sema::isTemplateName(Scope *S,
+                                      CXXScopeSpec &SS,
+                                      bool hasTemplateKeyword,
+                                      UnqualifiedId &Name,
+                                      ParsedType ObjectTypePtr,
+                                      bool EnteringContext,
+                                      TemplateTy &TemplateResult,
+                                      bool &MemberOfUnknownSpecialization) {
+  assert(getLangOpts().CPlusPlus && "No template names in C!");
+
+  DeclarationName TName;
+  MemberOfUnknownSpecialization = false;
+
+  switch (Name.getKind()) {
+  case UnqualifiedId::IK_Identifier:
+    TName = DeclarationName(Name.Identifier);
+    break;
+
+  case UnqualifiedId::IK_OperatorFunctionId:
+    TName = Context.DeclarationNames.getCXXOperatorName(
+                                              Name.OperatorFunctionId.Operator);
+    break;
+
+  case UnqualifiedId::IK_LiteralOperatorId:
+    TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
+    break;
+
+  default:
+    return TNK_Non_template;
+  }
+
+  QualType ObjectType = ObjectTypePtr.get();
+
+  LookupResult R(*this, TName, Name.getLocStart(), LookupOrdinaryName);
+  LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
+                     MemberOfUnknownSpecialization);
+  if (R.empty()) return TNK_Non_template;
+  if (R.isAmbiguous()) {
+    // Suppress diagnostics;  we'll redo this lookup later.
+    R.suppressDiagnostics();
+
+    // FIXME: we might have ambiguous templates, in which case we
+    // should at least parse them properly!
+    return TNK_Non_template;
+  }
+
+  TemplateName Template;
+  TemplateNameKind TemplateKind;
+
+  unsigned ResultCount = R.end() - R.begin();
+  if (ResultCount > 1) {
+    // We assume that we'll preserve the qualifier from a function
+    // template name in other ways.
+    Template = Context.getOverloadedTemplateName(R.begin(), R.end());
+    TemplateKind = TNK_Function_template;
+
+    // We'll do this lookup again later.
+    R.suppressDiagnostics();
+  } else {
+    TemplateDecl *TD = cast<TemplateDecl>((*R.begin())->getUnderlyingDecl());
+
+    if (SS.isSet() && !SS.isInvalid()) {
+      NestedNameSpecifier *Qualifier
+        = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+      Template = Context.getQualifiedTemplateName(Qualifier,
+                                                  hasTemplateKeyword, TD);
+    } else {
+      Template = TemplateName(TD);
+    }
+
+    if (isa<FunctionTemplateDecl>(TD)) {
+      TemplateKind = TNK_Function_template;
+
+      // We'll do this lookup again later.
+      R.suppressDiagnostics();
+    } else {
+      assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||
+             isa<TypeAliasTemplateDecl>(TD));
+      TemplateKind = TNK_Type_template;
+    }
+  }
+
+  TemplateResult = TemplateTy::make(Template);
+  return TemplateKind;
+}
+
+bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
+                                       SourceLocation IILoc,
+                                       Scope *S,
+                                       const CXXScopeSpec *SS,
+                                       TemplateTy &SuggestedTemplate,
+                                       TemplateNameKind &SuggestedKind) {
+  // We can't recover unless there's a dependent scope specifier preceding the
+  // template name.
+  // FIXME: Typo correction?
+  if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) ||
+      computeDeclContext(*SS))
+    return false;
+
+  // The code is missing a 'template' keyword prior to the dependent template
+  // name.
+  NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
+  Diag(IILoc, diag::err_template_kw_missing)
+    << Qualifier << II.getName()
+    << FixItHint::CreateInsertion(IILoc, "template ");
+  SuggestedTemplate
+    = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
+  SuggestedKind = TNK_Dependent_template_name;
+  return true;
+}
+
+void Sema::LookupTemplateName(LookupResult &Found,
+                              Scope *S, CXXScopeSpec &SS,
+                              QualType ObjectType,
+                              bool EnteringContext,
+                              bool &MemberOfUnknownSpecialization) {
+  // Determine where to perform name lookup
+  MemberOfUnknownSpecialization = false;
+  DeclContext *LookupCtx = 0;
+  bool isDependent = false;
+  if (!ObjectType.isNull()) {
+    // This nested-name-specifier occurs in a member access expression, e.g.,
+    // x->B::f, and we are looking into the type of the object.
+    assert(!SS.isSet() && "ObjectType and scope specifier cannot coexist");
+    LookupCtx = computeDeclContext(ObjectType);
+    isDependent = ObjectType->isDependentType();
+    assert((isDependent || !ObjectType->isIncompleteType()) &&
+           "Caller should have completed object type");
+    
+    // Template names cannot appear inside an Objective-C class or object type.
+    if (ObjectType->isObjCObjectOrInterfaceType()) {
+      Found.clear();
+      return;
+    }
+  } else if (SS.isSet()) {
+    // This nested-name-specifier occurs after another nested-name-specifier,
+    // so long into the context associated with the prior nested-name-specifier.
+    LookupCtx = computeDeclContext(SS, EnteringContext);
+    isDependent = isDependentScopeSpecifier(SS);
+
+    // The declaration context must be complete.
+    if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx))
+      return;
+  }
+
+  bool ObjectTypeSearchedInScope = false;
+  bool AllowFunctionTemplatesInLookup = true;
+  if (LookupCtx) {
+    // Perform "qualified" name lookup into the declaration context we
+    // computed, which is either the type of the base of a member access
+    // expression or the declaration context associated with a prior
+    // nested-name-specifier.
+    LookupQualifiedName(Found, LookupCtx);
+    if (!ObjectType.isNull() && Found.empty()) {
+      // C++ [basic.lookup.classref]p1:
+      //   In a class member access expression (5.2.5), if the . or -> token is
+      //   immediately followed by an identifier followed by a <, the
+      //   identifier must be looked up to determine whether the < is the
+      //   beginning of a template argument list (14.2) or a less-than operator.
+      //   The identifier is first looked up in the class of the object
+      //   expression. If the identifier is not found, it is then looked up in
+      //   the context of the entire postfix-expression and shall name a class
+      //   or function template.
+      if (S) LookupName(Found, S);
+      ObjectTypeSearchedInScope = true;
+      AllowFunctionTemplatesInLookup = false;
+    }
+  } else if (isDependent && (!S || ObjectType.isNull())) {
+    // We cannot look into a dependent object type or nested nme
+    // specifier.
+    MemberOfUnknownSpecialization = true;
+    return;
+  } else {
+    // Perform unqualified name lookup in the current scope.
+    LookupName(Found, S);
+    
+    if (!ObjectType.isNull())
+      AllowFunctionTemplatesInLookup = false;
+  }
+
+  if (Found.empty() && !isDependent) {
+    // If we did not find any names, attempt to correct any typos.
+    DeclarationName Name = Found.getLookupName();
+    Found.clear();
+    // Simple filter callback that, for keywords, only accepts the C++ *_cast
+    CorrectionCandidateCallback FilterCCC;
+    FilterCCC.WantTypeSpecifiers = false;
+    FilterCCC.WantExpressionKeywords = false;
+    FilterCCC.WantRemainingKeywords = false;
+    FilterCCC.WantCXXNamedCasts = true;
+    if (TypoCorrection Corrected = CorrectTypo(Found.getLookupNameInfo(),
+                                               Found.getLookupKind(), S, &SS,
+                                               FilterCCC, LookupCtx)) {
+      Found.setLookupName(Corrected.getCorrection());
+      if (Corrected.getCorrectionDecl())
+        Found.addDecl(Corrected.getCorrectionDecl());
+      FilterAcceptableTemplateNames(Found);
+      if (!Found.empty()) {
+        std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
+        std::string CorrectedQuotedStr(Corrected.getQuoted(getLangOpts()));
+        if (LookupCtx)
+          Diag(Found.getNameLoc(), diag::err_no_member_template_suggest)
+            << Name << LookupCtx << CorrectedQuotedStr << SS.getRange()
+            << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
+        else
+          Diag(Found.getNameLoc(), diag::err_no_template_suggest)
+            << Name << CorrectedQuotedStr
+            << FixItHint::CreateReplacement(Found.getNameLoc(), CorrectedStr);
+        if (TemplateDecl *Template = Found.getAsSingle<TemplateDecl>())
+          Diag(Template->getLocation(), diag::note_previous_decl)
+            << CorrectedQuotedStr;
+      }
+    } else {
+      Found.setLookupName(Name);
+    }
+  }
+
+  FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
+  if (Found.empty()) {
+    if (isDependent)
+      MemberOfUnknownSpecialization = true;
+    return;
+  }
+
+  if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope) {
+    // C++ [basic.lookup.classref]p1:
+    //   [...] If the lookup in the class of the object expression finds a
+    //   template, the name is also looked up in the context of the entire
+    //   postfix-expression and [...]
+    //
+    LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
+                            LookupOrdinaryName);
+    LookupName(FoundOuter, S);
+    FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
+
+    if (FoundOuter.empty()) {
+      //   - if the name is not found, the name found in the class of the
+      //     object expression is used, otherwise
+    } else if (!FoundOuter.getAsSingle<ClassTemplateDecl>() ||
+               FoundOuter.isAmbiguous()) {
+      //   - if the name is found in the context of the entire
+      //     postfix-expression and does not name a class template, the name
+      //     found in the class of the object expression is used, otherwise
+      FoundOuter.clear();
+    } else if (!Found.isSuppressingDiagnostics()) {
+      //   - if the name found is a class template, it must refer to the same
+      //     entity as the one found in the class of the object expression,
+      //     otherwise the program is ill-formed.
+      if (!Found.isSingleResult() ||
+          Found.getFoundDecl()->getCanonicalDecl()
+            != FoundOuter.getFoundDecl()->getCanonicalDecl()) {
+        Diag(Found.getNameLoc(),
+             diag::ext_nested_name_member_ref_lookup_ambiguous)
+          << Found.getLookupName()
+          << ObjectType;
+        Diag(Found.getRepresentativeDecl()->getLocation(),
+             diag::note_ambig_member_ref_object_type)
+          << ObjectType;
+        Diag(FoundOuter.getFoundDecl()->getLocation(),
+             diag::note_ambig_member_ref_scope);
+
+        // Recover by taking the template that we found in the object
+        // expression's type.
+      }
+    }
+  }
+}
+
+/// ActOnDependentIdExpression - Handle a dependent id-expression that
+/// was just parsed.  This is only possible with an explicit scope
+/// specifier naming a dependent type.
+ExprResult
+Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
+                                 SourceLocation TemplateKWLoc,
+                                 const DeclarationNameInfo &NameInfo,
+                                 bool isAddressOfOperand,
+                           const TemplateArgumentListInfo *TemplateArgs) {
+  DeclContext *DC = getFunctionLevelDeclContext();
+
+  if (!isAddressOfOperand &&
+      isa<CXXMethodDecl>(DC) &&
+      cast<CXXMethodDecl>(DC)->isInstance()) {
+    QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType(Context);
+
+    // Since the 'this' expression is synthesized, we don't need to
+    // perform the double-lookup check.
+    NamedDecl *FirstQualifierInScope = 0;
+
+    return Owned(CXXDependentScopeMemberExpr::Create(Context,
+                                                     /*This*/ 0, ThisType,
+                                                     /*IsArrow*/ true,
+                                                     /*Op*/ SourceLocation(),
+                                               SS.getWithLocInContext(Context),
+                                                     TemplateKWLoc,
+                                                     FirstQualifierInScope,
+                                                     NameInfo,
+                                                     TemplateArgs));
+  }
+
+  return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
+}
+
+ExprResult
+Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
+                                SourceLocation TemplateKWLoc,
+                                const DeclarationNameInfo &NameInfo,
+                                const TemplateArgumentListInfo *TemplateArgs) {
+  return Owned(DependentScopeDeclRefExpr::Create(Context,
+                                               SS.getWithLocInContext(Context),
+                                                 TemplateKWLoc,
+                                                 NameInfo,
+                                                 TemplateArgs));
+}
+
+/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
+/// that the template parameter 'PrevDecl' is being shadowed by a new
+/// declaration at location Loc. Returns true to indicate that this is
+/// an error, and false otherwise.
+void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
+  assert(PrevDecl->isTemplateParameter() && "Not a template parameter");
+
+  // Microsoft Visual C++ permits template parameters to be shadowed.
+  if (getLangOpts().MicrosoftExt)
+    return;
+
+  // C++ [temp.local]p4:
+  //   A template-parameter shall not be redeclared within its
+  //   scope (including nested scopes).
+  Diag(Loc, diag::err_template_param_shadow)
+    << cast<NamedDecl>(PrevDecl)->getDeclName();
+  Diag(PrevDecl->getLocation(), diag::note_template_param_here);
+  return;
+}
+
+/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
+/// the parameter D to reference the templated declaration and return a pointer
+/// to the template declaration. Otherwise, do nothing to D and return null.
+TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
+  if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
+    D = Temp->getTemplatedDecl();
+    return Temp;
+  }
+  return 0;
+}
+
+ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
+                                             SourceLocation EllipsisLoc) const {
+  assert(Kind == Template &&
+         "Only template template arguments can be pack expansions here");
+  assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
+         "Template template argument pack expansion without packs");
+  ParsedTemplateArgument Result(*this);
+  Result.EllipsisLoc = EllipsisLoc;
+  return Result;
+}
+
+static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
+                                            const ParsedTemplateArgument &Arg) {
+
+  switch (Arg.getKind()) {
+  case ParsedTemplateArgument::Type: {
+    TypeSourceInfo *DI;
+    QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
+    if (!DI)
+      DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
+    return TemplateArgumentLoc(TemplateArgument(T), DI);
+  }
+
+  case ParsedTemplateArgument::NonType: {
+    Expr *E = static_cast<Expr *>(Arg.getAsExpr());
+    return TemplateArgumentLoc(TemplateArgument(E), E);
+  }
+
+  case ParsedTemplateArgument::Template: {
+    TemplateName Template = Arg.getAsTemplate().get();
+    TemplateArgument TArg;
+    if (Arg.getEllipsisLoc().isValid())
+      TArg = TemplateArgument(Template, llvm::Optional<unsigned int>());
+    else
+      TArg = Template;
+    return TemplateArgumentLoc(TArg,
+                               Arg.getScopeSpec().getWithLocInContext(
+                                                              SemaRef.Context),
+                               Arg.getLocation(),
+                               Arg.getEllipsisLoc());
+  }
+  }
+
+  llvm_unreachable("Unhandled parsed template argument");
+}
+
+/// \brief Translates template arguments as provided by the parser
+/// into template arguments used by semantic analysis.
+void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
+                                      TemplateArgumentListInfo &TemplateArgs) {
+ for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
+   TemplateArgs.addArgument(translateTemplateArgument(*this,
+                                                      TemplateArgsIn[I]));
+}
+
+/// ActOnTypeParameter - Called when a C++ template type parameter
+/// (e.g., "typename T") has been parsed. Typename specifies whether
+/// the keyword "typename" was used to declare the type parameter
+/// (otherwise, "class" was used), and KeyLoc is the location of the
+/// "class" or "typename" keyword. ParamName is the name of the
+/// parameter (NULL indicates an unnamed template parameter) and
+/// ParamNameLoc is the location of the parameter name (if any).
+/// If the type parameter has a default argument, it will be added
+/// later via ActOnTypeParameterDefault.
+Decl *Sema::ActOnTypeParameter(Scope *S, bool Typename, bool Ellipsis,
+                               SourceLocation EllipsisLoc,
+                               SourceLocation KeyLoc,
+                               IdentifierInfo *ParamName,
+                               SourceLocation ParamNameLoc,
+                               unsigned Depth, unsigned Position,
+                               SourceLocation EqualLoc,
+                               ParsedType DefaultArg) {
+  assert(S->isTemplateParamScope() &&
+         "Template type parameter not in template parameter scope!");
+  bool Invalid = false;
+
+  if (ParamName) {
+    NamedDecl *PrevDecl = LookupSingleName(S, ParamName, ParamNameLoc,
+                                           LookupOrdinaryName,
+                                           ForRedeclaration);
+    if (PrevDecl && PrevDecl->isTemplateParameter()) {
+      DiagnoseTemplateParameterShadow(ParamNameLoc, PrevDecl);
+      PrevDecl = 0;
+    }
+  }
+
+  SourceLocation Loc = ParamNameLoc;
+  if (!ParamName)
+    Loc = KeyLoc;
+
+  TemplateTypeParmDecl *Param
+    = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
+                                   KeyLoc, Loc, Depth, Position, ParamName,
+                                   Typename, Ellipsis);
+  Param->setAccess(AS_public);
+  if (Invalid)
+    Param->setInvalidDecl();
+
+  if (ParamName) {
+    // Add the template parameter into the current scope.
+    S->AddDecl(Param);
+    IdResolver.AddDecl(Param);
+  }
+
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (DefaultArg && Ellipsis) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    DefaultArg = ParsedType();
+  }
+
+  // Handle the default argument, if provided.
+  if (DefaultArg) {
+    TypeSourceInfo *DefaultTInfo;
+    GetTypeFromParser(DefaultArg, &DefaultTInfo);
+
+    assert(DefaultTInfo && "expected source information for type");
+
+    // Check for unexpanded parameter packs.
+    if (DiagnoseUnexpandedParameterPack(Loc, DefaultTInfo,
+                                        UPPC_DefaultArgument))
+      return Param;
+
+    // Check the template argument itself.
+    if (CheckTemplateArgument(Param, DefaultTInfo)) {
+      Param->setInvalidDecl();
+      return Param;
+    }
+
+    Param->setDefaultArgument(DefaultTInfo, false);
+  }
+
+  return Param;
+}
+
+/// \brief Check that the type of a non-type template parameter is
+/// well-formed.
+///
+/// \returns the (possibly-promoted) parameter type if valid;
+/// otherwise, produces a diagnostic and returns a NULL type.
+QualType
+Sema::CheckNonTypeTemplateParameterType(QualType T, SourceLocation Loc) {
+  // We don't allow variably-modified types as the type of non-type template
+  // parameters.
+  if (T->isVariablyModifiedType()) {
+    Diag(Loc, diag::err_variably_modified_nontype_template_param)
+      << T;
+    return QualType();
+  }
+
+  // C++ [temp.param]p4:
+  //
+  // A non-type template-parameter shall have one of the following
+  // (optionally cv-qualified) types:
+  //
+  //       -- integral or enumeration type,
+  if (T->isIntegralOrEnumerationType() ||
+      //   -- pointer to object or pointer to function,
+      T->isPointerType() ||
+      //   -- reference to object or reference to function,
+      T->isReferenceType() ||
+      //   -- pointer to member,
+      T->isMemberPointerType() ||
+      //   -- std::nullptr_t.
+      T->isNullPtrType() ||
+      // If T is a dependent type, we can't do the check now, so we
+      // assume that it is well-formed.
+      T->isDependentType()) {
+    // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
+    // are ignored when determining its type.
+    return T.getUnqualifiedType();
+  }
+
+  // C++ [temp.param]p8:
+  //
+  //   A non-type template-parameter of type "array of T" or
+  //   "function returning T" is adjusted to be of type "pointer to
+  //   T" or "pointer to function returning T", respectively.
+  else if (T->isArrayType())
+    // FIXME: Keep the type prior to promotion?
+    return Context.getArrayDecayedType(T);
+  else if (T->isFunctionType())
+    // FIXME: Keep the type prior to promotion?
+    return Context.getPointerType(T);
+
+  Diag(Loc, diag::err_template_nontype_parm_bad_type)
+    << T;
+
+  return QualType();
+}
+
+Decl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
+                                          unsigned Depth,
+                                          unsigned Position,
+                                          SourceLocation EqualLoc,
+                                          Expr *Default) {
+  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
+  QualType T = TInfo->getType();
+
+  assert(S->isTemplateParamScope() &&
+         "Non-type template parameter not in template parameter scope!");
+  bool Invalid = false;
+
+  IdentifierInfo *ParamName = D.getIdentifier();
+  if (ParamName) {
+    NamedDecl *PrevDecl = LookupSingleName(S, ParamName, D.getIdentifierLoc(),
+                                           LookupOrdinaryName,
+                                           ForRedeclaration);
+    if (PrevDecl && PrevDecl->isTemplateParameter()) {
+      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(), PrevDecl);
+      PrevDecl = 0;
+    }
+  }
+
+  T = CheckNonTypeTemplateParameterType(T, D.getIdentifierLoc());
+  if (T.isNull()) {
+    T = Context.IntTy; // Recover with an 'int' type.
+    Invalid = true;
+  }
+
+  bool IsParameterPack = D.hasEllipsis();
+  NonTypeTemplateParmDecl *Param
+    = NonTypeTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
+                                      D.getLocStart(),
+                                      D.getIdentifierLoc(),
+                                      Depth, Position, ParamName, T,
+                                      IsParameterPack, TInfo);
+  Param->setAccess(AS_public);
+  
+  if (Invalid)
+    Param->setInvalidDecl();
+
+  if (D.getIdentifier()) {
+    // Add the template parameter into the current scope.
+    S->AddDecl(Param);
+    IdResolver.AddDecl(Param);
+  }
+
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (Default && IsParameterPack) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    Default = 0;
+  }
+
+  // Check the well-formedness of the default template argument, if provided.
+  if (Default) {
+    // Check for unexpanded parameter packs.
+    if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
+      return Param;
+
+    TemplateArgument Converted;
+    ExprResult DefaultRes = CheckTemplateArgument(Param, Param->getType(), Default, Converted);
+    if (DefaultRes.isInvalid()) {
+      Param->setInvalidDecl();
+      return Param;
+    }
+    Default = DefaultRes.take();
+
+    Param->setDefaultArgument(Default, false);
+  }
+
+  return Param;
+}
+
+/// ActOnTemplateTemplateParameter - Called when a C++ template template
+/// parameter (e.g. T in template <template <typename> class T> class array)
+/// has been parsed. S is the current scope.
+Decl *Sema::ActOnTemplateTemplateParameter(Scope* S,
+                                           SourceLocation TmpLoc,
+                                           TemplateParameterList *Params,
+                                           SourceLocation EllipsisLoc,
+                                           IdentifierInfo *Name,
+                                           SourceLocation NameLoc,
+                                           unsigned Depth,
+                                           unsigned Position,
+                                           SourceLocation EqualLoc,
+                                           ParsedTemplateArgument Default) {
+  assert(S->isTemplateParamScope() &&
+         "Template template parameter not in template parameter scope!");
+
+  // Construct the parameter object.
+  bool IsParameterPack = EllipsisLoc.isValid();
+  TemplateTemplateParmDecl *Param =
+    TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
+                                     NameLoc.isInvalid()? TmpLoc : NameLoc,
+                                     Depth, Position, IsParameterPack,
+                                     Name, Params);
+  Param->setAccess(AS_public);
+  
+  // If the template template parameter has a name, then link the identifier
+  // into the scope and lookup mechanisms.
+  if (Name) {
+    S->AddDecl(Param);
+    IdResolver.AddDecl(Param);
+  }
+
+  if (Params->size() == 0) {
+    Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
+    << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
+    Param->setInvalidDecl();
+  }
+
+  // C++0x [temp.param]p9:
+  //   A default template-argument may be specified for any kind of
+  //   template-parameter that is not a template parameter pack.
+  if (IsParameterPack && !Default.isInvalid()) {
+    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
+    Default = ParsedTemplateArgument();
+  }
+
+  if (!Default.isInvalid()) {
+    // Check only that we have a template template argument. We don't want to
+    // try to check well-formedness now, because our template template parameter
+    // might have dependent types in its template parameters, which we wouldn't
+    // be able to match now.
+    //
+    // If none of the template template parameter's template arguments mention
+    // other template parameters, we could actually perform more checking here.
+    // However, it isn't worth doing.
+    TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
+    if (DefaultArg.getArgument().getAsTemplate().isNull()) {
+      Diag(DefaultArg.getLocation(), diag::err_template_arg_not_class_template)
+        << DefaultArg.getSourceRange();
+      return Param;
+    }
+
+    // Check for unexpanded parameter packs.
+    if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
+                                        DefaultArg.getArgument().getAsTemplate(),
+                                        UPPC_DefaultArgument))
+      return Param;
+
+    Param->setDefaultArgument(DefaultArg, false);
+  }
+
+  return Param;
+}
+
+/// ActOnTemplateParameterList - Builds a TemplateParameterList that
+/// contains the template parameters in Params/NumParams.
+TemplateParameterList *
+Sema::ActOnTemplateParameterList(unsigned Depth,
+                                 SourceLocation ExportLoc,
+                                 SourceLocation TemplateLoc,
+                                 SourceLocation LAngleLoc,
+                                 Decl **Params, unsigned NumParams,
+                                 SourceLocation RAngleLoc) {
+  if (ExportLoc.isValid())
+    Diag(ExportLoc, diag::warn_template_export_unsupported);
+
+  return TemplateParameterList::Create(Context, TemplateLoc, LAngleLoc,
+                                       (NamedDecl**)Params, NumParams,
+                                       RAngleLoc);
+}
+
+static void SetNestedNameSpecifier(TagDecl *T, const CXXScopeSpec &SS) {
+  if (SS.isSet())
+    T->setQualifierInfo(SS.getWithLocInContext(T->getASTContext()));
+}
+
+DeclResult
+Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
+                         SourceLocation KWLoc, CXXScopeSpec &SS,
+                         IdentifierInfo *Name, SourceLocation NameLoc,
+                         AttributeList *Attr,
+                         TemplateParameterList *TemplateParams,
+                         AccessSpecifier AS, SourceLocation ModulePrivateLoc,
+                         unsigned NumOuterTemplateParamLists,
+                         TemplateParameterList** OuterTemplateParamLists) {
+  assert(TemplateParams && TemplateParams->size() > 0 &&
+         "No template parameters");
+  assert(TUK != TUK_Reference && "Can only declare or define class templates");
+  bool Invalid = false;
+
+  // Check that we can declare a template here.
+  if (CheckTemplateDeclScope(S, TemplateParams))
+    return true;
+
+  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
+  assert(Kind != TTK_Enum && "can't build template of enumerated type");
+
+  // There is no such thing as an unnamed class template.
+  if (!Name) {
+    Diag(KWLoc, diag::err_template_unnamed_class);
+    return true;
+  }
+
+  // Find any previous declaration with this name.
+  DeclContext *SemanticContext;
+  LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName,
+                        ForRedeclaration);
+  if (SS.isNotEmpty() && !SS.isInvalid()) {
+    SemanticContext = computeDeclContext(SS, true);
+    if (!SemanticContext) {
+      // FIXME: Horrible, horrible hack! We can't currently represent this
+      // in the AST, and historically we have just ignored such friend
+      // class templates, so don't complain here.
+      if (TUK != TUK_Friend)
+        Diag(NameLoc, diag::err_template_qualified_declarator_no_match)
+          << SS.getScopeRep() << SS.getRange();
+      return true;
+    }
+
+    if (RequireCompleteDeclContext(SS, SemanticContext))
+      return true;
+
+    // If we're adding a template to a dependent context, we may need to 
+    // rebuilding some of the types used within the template parameter list, 
+    // now that we know what the current instantiation is.
+    if (SemanticContext->isDependentContext()) {
+      ContextRAII SavedContext(*this, SemanticContext);
+      if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
+        Invalid = true;
+    } else if (TUK != TUK_Friend && TUK != TUK_Reference)
+      diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc);
+        
+    LookupQualifiedName(Previous, SemanticContext);
+  } else {
+    SemanticContext = CurContext;
+    LookupName(Previous, S);
+  }
+
+  if (Previous.isAmbiguous())
+    return true;
+
+  NamedDecl *PrevDecl = 0;
+  if (Previous.begin() != Previous.end())
+    PrevDecl = (*Previous.begin())->getUnderlyingDecl();
+
+  // If there is a previous declaration with the same name, check
+  // whether this is a valid redeclaration.
+  ClassTemplateDecl *PrevClassTemplate
+    = dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
+
+  // We may have found the injected-class-name of a class template,
+  // class template partial specialization, or class template specialization.
+  // In these cases, grab the template that is being defined or specialized.
+  if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
+      cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
+    PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
+    PrevClassTemplate
+      = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
+    if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
+      PrevClassTemplate
+        = cast<ClassTemplateSpecializationDecl>(PrevDecl)
+            ->getSpecializedTemplate();
+    }
+  }
+
+  if (TUK == TUK_Friend) {
+    // C++ [namespace.memdef]p3:
+    //   [...] When looking for a prior declaration of a class or a function
+    //   declared as a friend, and when the name of the friend class or
+    //   function is neither a qualified name nor a template-id, scopes outside
+    //   the innermost enclosing namespace scope are not considered.
+    if (!SS.isSet()) {
+      DeclContext *OutermostContext = CurContext;
+      while (!OutermostContext->isFileContext())
+        OutermostContext = OutermostContext->getLookupParent();
+
+      if (PrevDecl &&
+          (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
+           OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
+        SemanticContext = PrevDecl->getDeclContext();
+      } else {
+        // Declarations in outer scopes don't matter. However, the outermost
+        // context we computed is the semantic context for our new
+        // declaration.
+        PrevDecl = PrevClassTemplate = 0;
+        SemanticContext = OutermostContext;
+      }
+    }
+
+    if (CurContext->isDependentContext()) {
+      // If this is a dependent context, we don't want to link the friend
+      // class template to the template in scope, because that would perform
+      // checking of the template parameter lists that can't be performed
+      // until the outer context is instantiated.
+      PrevDecl = PrevClassTemplate = 0;
+    }
+  } else if (PrevDecl && !isDeclInScope(PrevDecl, SemanticContext, S))
+    PrevDecl = PrevClassTemplate = 0;
+
+  if (PrevClassTemplate) {
+    // Ensure that the template parameter lists are compatible.
+    if (!TemplateParameterListsAreEqual(TemplateParams,
+                                   PrevClassTemplate->getTemplateParameters(),
+                                        /*Complain=*/true,
+                                        TPL_TemplateMatch))
+      return true;
+
+    // C++ [temp.class]p4:
+    //   In a redeclaration, partial specialization, explicit
+    //   specialization or explicit instantiation of a class template,
+    //   the class-key shall agree in kind with the original class
+    //   template declaration (7.1.5.3).
+    RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
+    if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
+                                      TUK == TUK_Definition,  KWLoc, *Name)) {
+      Diag(KWLoc, diag::err_use_with_wrong_tag)
+        << Name
+        << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
+      Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
+      Kind = PrevRecordDecl->getTagKind();
+    }
+
+    // Check for redefinition of this class template.
+    if (TUK == TUK_Definition) {
+      if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
+        Diag(NameLoc, diag::err_redefinition) << Name;
+        Diag(Def->getLocation(), diag::note_previous_definition);
+        // FIXME: Would it make sense to try to "forget" the previous
+        // definition, as part of error recovery?
+        return true;
+      }
+    }    
+  } else if (PrevDecl && PrevDecl->isTemplateParameter()) {
+    // Maybe we will complain about the shadowed template parameter.
+    DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
+    // Just pretend that we didn't see the previous declaration.
+    PrevDecl = 0;
+  } else if (PrevDecl) {
+    // C++ [temp]p5:
+    //   A class template shall not have the same name as any other
+    //   template, class, function, object, enumeration, enumerator,
+    //   namespace, or type in the same scope (3.3), except as specified
+    //   in (14.5.4).
+    Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
+    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
+    return true;
+  }
+
+  // Check the template parameter list of this declaration, possibly
+  // merging in the template parameter list from the previous class
+  // template declaration.
+  if (CheckTemplateParameterList(TemplateParams,
+            PrevClassTemplate? PrevClassTemplate->getTemplateParameters() : 0,
+                                 (SS.isSet() && SemanticContext &&
+                                  SemanticContext->isRecord() &&
+                                  SemanticContext->isDependentContext())
+                                   ? TPC_ClassTemplateMember
+                                   : TPC_ClassTemplate))
+    Invalid = true;
+
+  if (SS.isSet()) {
+    // If the name of the template was qualified, we must be defining the
+    // template out-of-line.
+    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate &&
+        !(TUK == TUK_Friend && CurContext->isDependentContext())) {
+      Diag(NameLoc, diag::err_member_def_does_not_match)
+        << Name << SemanticContext << SS.getRange();
+      Invalid = true;
+    }
+  }
+
+  CXXRecordDecl *NewClass =
+    CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
+                          PrevClassTemplate?
+                            PrevClassTemplate->getTemplatedDecl() : 0,
+                          /*DelayTypeCreation=*/true);
+  SetNestedNameSpecifier(NewClass, SS);
+  if (NumOuterTemplateParamLists > 0)
+    NewClass->setTemplateParameterListsInfo(Context,
+                                            NumOuterTemplateParamLists,
+                                            OuterTemplateParamLists);
+
+  // Add alignment attributes if necessary; these attributes are checked when
+  // the ASTContext lays out the structure.
+  AddAlignmentAttributesForRecord(NewClass);
+  AddMsStructLayoutForRecord(NewClass);
+
+  ClassTemplateDecl *NewTemplate
+    = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
+                                DeclarationName(Name), TemplateParams,
+                                NewClass, PrevClassTemplate);
+  NewClass->setDescribedClassTemplate(NewTemplate);
+  
+  if (ModulePrivateLoc.isValid())
+    NewTemplate->setModulePrivate();
+  
+  // Build the type for the class template declaration now.
+  QualType T = NewTemplate->getInjectedClassNameSpecialization();
+  T = Context.getInjectedClassNameType(NewClass, T);
+  assert(T->isDependentType() && "Class template type is not dependent?");
+  (void)T;
+
+  // If we are providing an explicit specialization of a member that is a
+  // class template, make a note of that.
+  if (PrevClassTemplate &&
+      PrevClassTemplate->getInstantiatedFromMemberTemplate())
+    PrevClassTemplate->setMemberSpecialization();
+
+  // Set the access specifier.
+  if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
+    SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
+
+  // Set the lexical context of these templates
+  NewClass->setLexicalDeclContext(CurContext);
+  NewTemplate->setLexicalDeclContext(CurContext);
+
+  if (TUK == TUK_Definition)
+    NewClass->startDefinition();
+
+  if (Attr)
+    ProcessDeclAttributeList(S, NewClass, Attr);
+
+  if (TUK != TUK_Friend)
+    PushOnScopeChains(NewTemplate, S);
+  else {
+    if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
+      NewTemplate->setAccess(PrevClassTemplate->getAccess());
+      NewClass->setAccess(PrevClassTemplate->getAccess());
+    }
+
+    NewTemplate->setObjectOfFriendDecl(/* PreviouslyDeclared = */
+                                       PrevClassTemplate != NULL);
+
+    // Friend templates are visible in fairly strange ways.
+    if (!CurContext->isDependentContext()) {
+      DeclContext *DC = SemanticContext->getRedeclContext();
+      DC->makeDeclVisibleInContext(NewTemplate);
+      if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
+        PushOnScopeChains(NewTemplate, EnclosingScope,
+                          /* AddToContext = */ false);
+    }
+
+    FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
+                                            NewClass->getLocation(),
+                                            NewTemplate,
+                                    /*FIXME:*/NewClass->getLocation());
+    Friend->setAccess(AS_public);
+    CurContext->addDecl(Friend);
+  }
+
+  if (Invalid) {
+    NewTemplate->setInvalidDecl();
+    NewClass->setInvalidDecl();
+  }
+  return NewTemplate;
+}
+
+/// \brief Diagnose the presence of a default template argument on a
+/// template parameter, which is ill-formed in certain contexts.
+///
+/// \returns true if the default template argument should be dropped.
+static bool DiagnoseDefaultTemplateArgument(Sema &S,
+                                            Sema::TemplateParamListContext TPC,
+                                            SourceLocation ParamLoc,
+                                            SourceRange DefArgRange) {
+  switch (TPC) {
+  case Sema::TPC_ClassTemplate:
+  case Sema::TPC_TypeAliasTemplate:
+    return false;
+
+  case Sema::TPC_FunctionTemplate:
+  case Sema::TPC_FriendFunctionTemplateDefinition:
+    // C++ [temp.param]p9:
+    //   A default template-argument shall not be specified in a
+    //   function template declaration or a function template
+    //   definition [...]
+    //   If a friend function template declaration specifies a default 
+    //   template-argument, that declaration shall be a definition and shall be
+    //   the only declaration of the function template in the translation unit.
+    // (C++98/03 doesn't have this wording; see DR226).
+    S.Diag(ParamLoc, S.getLangOpts().CPlusPlus0x ?
+         diag::warn_cxx98_compat_template_parameter_default_in_function_template
+           : diag::ext_template_parameter_default_in_function_template)
+      << DefArgRange;
+    return false;
+
+  case Sema::TPC_ClassTemplateMember:
+    // C++0x [temp.param]p9:
+    //   A default template-argument shall not be specified in the
+    //   template-parameter-lists of the definition of a member of a
+    //   class template that appears outside of the member's class.
+    S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
+      << DefArgRange;
+    return true;
+
+  case Sema::TPC_FriendFunctionTemplate:
+    // C++ [temp.param]p9:
+    //   A default template-argument shall not be specified in a
+    //   friend template declaration.
+    S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
+      << DefArgRange;
+    return true;
+
+    // FIXME: C++0x [temp.param]p9 allows default template-arguments
+    // for friend function templates if there is only a single
+    // declaration (and it is a definition). Strange!
+  }
+
+  llvm_unreachable("Invalid TemplateParamListContext!");
+}
+
+/// \brief Check for unexpanded parameter packs within the template parameters
+/// of a template template parameter, recursively.
+static bool DiagnoseUnexpandedParameterPacks(Sema &S,
+                                             TemplateTemplateParmDecl *TTP) {
+  TemplateParameterList *Params = TTP->getTemplateParameters();
+  for (unsigned I = 0, N = Params->size(); I != N; ++I) {
+    NamedDecl *P = Params->getParam(I);
+    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
+      if (S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
+                                            NTTP->getTypeSourceInfo(),
+                                      Sema::UPPC_NonTypeTemplateParameterType))
+        return true;
+
+      continue;
+    }
+
+    if (TemplateTemplateParmDecl *InnerTTP
+                                        = dyn_cast<TemplateTemplateParmDecl>(P))
+      if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
+        return true;
+  }
+
+  return false;
+}
+
+/// \brief Checks the validity of a template parameter list, possibly
+/// considering the template parameter list from a previous
+/// declaration.
+///
+/// If an "old" template parameter list is provided, it must be
+/// equivalent (per TemplateParameterListsAreEqual) to the "new"
+/// template parameter list.
+///
+/// \param NewParams Template parameter list for a new template
+/// declaration. This template parameter list will be updated with any
+/// default arguments that are carried through from the previous
+/// template parameter list.
+///
+/// \param OldParams If provided, template parameter list from a
+/// previous declaration of the same template. Default template
+/// arguments will be merged from the old template parameter list to
+/// the new template parameter list.
+///
+/// \param TPC Describes the context in which we are checking the given
+/// template parameter list.
+///
+/// \returns true if an error occurred, false otherwise.
+bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
+                                      TemplateParameterList *OldParams,
+                                      TemplateParamListContext TPC) {
+  bool Invalid = false;
+
+  // C++ [temp.param]p10:
+  //   The set of default template-arguments available for use with a
+  //   template declaration or definition is obtained by merging the
+  //   default arguments from the definition (if in scope) and all
+  //   declarations in scope in the same way default function
+  //   arguments are (8.3.6).
+  bool SawDefaultArgument = false;
+  SourceLocation PreviousDefaultArgLoc;
+
+  // Dummy initialization to avoid warnings.
+  TemplateParameterList::iterator OldParam = NewParams->end();
+  if (OldParams)
+    OldParam = OldParams->begin();
+
+  bool RemoveDefaultArguments = false;
+  for (TemplateParameterList::iterator NewParam = NewParams->begin(),
+                                    NewParamEnd = NewParams->end();
+       NewParam != NewParamEnd; ++NewParam) {
+    // Variables used to diagnose redundant default arguments
+    bool RedundantDefaultArg = false;
+    SourceLocation OldDefaultLoc;
+    SourceLocation NewDefaultLoc;
+
+    // Variable used to diagnose missing default arguments
+    bool MissingDefaultArg = false;
+
+    // Variable used to diagnose non-final parameter packs
+    bool SawParameterPack = false;
+
+    if (TemplateTypeParmDecl *NewTypeParm
+          = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
+      // Check the presence of a default argument here.
+      if (NewTypeParm->hasDefaultArgument() &&
+          DiagnoseDefaultTemplateArgument(*this, TPC,
+                                          NewTypeParm->getLocation(),
+               NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
+                                                       .getSourceRange()))
+        NewTypeParm->removeDefaultArgument();
+
+      // Merge default arguments for template type parameters.
+      TemplateTypeParmDecl *OldTypeParm
+          = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : 0;
+
+      if (NewTypeParm->isParameterPack()) {
+        assert(!NewTypeParm->hasDefaultArgument() &&
+               "Parameter packs can't have a default argument!");
+        SawParameterPack = true;
+      } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() &&
+                 NewTypeParm->hasDefaultArgument()) {
+        OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
+        NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
+        SawDefaultArgument = true;
+        RedundantDefaultArg = true;
+        PreviousDefaultArgLoc = NewDefaultLoc;
+      } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
+        // Merge the default argument from the old declaration to the
+        // new declaration.
+        SawDefaultArgument = true;
+        NewTypeParm->setDefaultArgument(OldTypeParm->getDefaultArgumentInfo(),
+                                        true);
+        PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
+      } else if (NewTypeParm->hasDefaultArgument()) {
+        SawDefaultArgument = true;
+        PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
+      } else if (SawDefaultArgument)
+        MissingDefaultArg = true;
+    } else if (NonTypeTemplateParmDecl *NewNonTypeParm
+               = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
+      // Check for unexpanded parameter packs.
+      if (DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
+                                          NewNonTypeParm->getTypeSourceInfo(),
+                                          UPPC_NonTypeTemplateParameterType)) {
+        Invalid = true;
+        continue;
+      }
+
+      // Check the presence of a default argument here.
+      if (NewNonTypeParm->hasDefaultArgument() &&
+          DiagnoseDefaultTemplateArgument(*this, TPC,
+                                          NewNonTypeParm->getLocation(),
+                    NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
+        NewNonTypeParm->removeDefaultArgument();
+      }
+
+      // Merge default arguments for non-type template parameters
+      NonTypeTemplateParmDecl *OldNonTypeParm
+        = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : 0;
+      if (NewNonTypeParm->isParameterPack()) {
+        assert(!NewNonTypeParm->hasDefaultArgument() &&
+               "Parameter packs can't have a default argument!");
+        SawParameterPack = true;
+      } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() &&
+          NewNonTypeParm->hasDefaultArgument()) {
+        OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
+        NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
+        SawDefaultArgument = true;
+        RedundantDefaultArg = true;
+        PreviousDefaultArgLoc = NewDefaultLoc;
+      } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
+        // Merge the default argument from the old declaration to the
+        // new declaration.
+        SawDefaultArgument = true;
+        // FIXME: We need to create a new kind of "default argument"
+        // expression that points to a previous non-type template
+        // parameter.
+        NewNonTypeParm->setDefaultArgument(
+                                         OldNonTypeParm->getDefaultArgument(),
+                                         /*Inherited=*/ true);
+        PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
+      } else if (NewNonTypeParm->hasDefaultArgument()) {
+        SawDefaultArgument = true;
+        PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
+      } else if (SawDefaultArgument)
+        MissingDefaultArg = true;
+    } else {
+      TemplateTemplateParmDecl *NewTemplateParm
+        = cast<TemplateTemplateParmDecl>(*NewParam);
+
+      // Check for unexpanded parameter packs, recursively.
+      if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
+        Invalid = true;
+        continue;
+      }
+
+      // Check the presence of a default argument here.
+      if (NewTemplateParm->hasDefaultArgument() &&
+          DiagnoseDefaultTemplateArgument(*this, TPC,
+                                          NewTemplateParm->getLocation(),
+                     NewTemplateParm->getDefaultArgument().getSourceRange()))
+        NewTemplateParm->removeDefaultArgument();
+
+      // Merge default arguments for template template parameters
+      TemplateTemplateParmDecl *OldTemplateParm
+        = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : 0;
+      if (NewTemplateParm->isParameterPack()) {
+        assert(!NewTemplateParm->hasDefaultArgument() &&
+               "Parameter packs can't have a default argument!");
+        SawParameterPack = true;
+      } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() &&
+          NewTemplateParm->hasDefaultArgument()) {
+        OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
+        NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
+        SawDefaultArgument = true;
+        RedundantDefaultArg = true;
+        PreviousDefaultArgLoc = NewDefaultLoc;
+      } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
+        // Merge the default argument from the old declaration to the
+        // new declaration.
+        SawDefaultArgument = true;
+        // FIXME: We need to create a new kind of "default argument" expression
+        // that points to a previous template template parameter.
+        NewTemplateParm->setDefaultArgument(
+                                          OldTemplateParm->getDefaultArgument(),
+                                          /*Inherited=*/ true);
+        PreviousDefaultArgLoc
+          = OldTemplateParm->getDefaultArgument().getLocation();
+      } else if (NewTemplateParm->hasDefaultArgument()) {
+        SawDefaultArgument = true;
+        PreviousDefaultArgLoc
+          = NewTemplateParm->getDefaultArgument().getLocation();
+      } else if (SawDefaultArgument)
+        MissingDefaultArg = true;
+    }
+
+    // C++0x [temp.param]p11:
+    //   If a template parameter of a primary class template or alias template
+    //   is a template parameter pack, it shall be the last template parameter.
+    if (SawParameterPack && (NewParam + 1) != NewParamEnd && 
+        (TPC == TPC_ClassTemplate || TPC == TPC_TypeAliasTemplate)) {
+      Diag((*NewParam)->getLocation(),
+           diag::err_template_param_pack_must_be_last_template_parameter);
+      Invalid = true;
+    }
+
+    if (RedundantDefaultArg) {
+      // C++ [temp.param]p12:
+      //   A template-parameter shall not be given default arguments
+      //   by two different declarations in the same scope.
+      Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
+      Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
+      Invalid = true;
+    } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
+      // C++ [temp.param]p11:
+      //   If a template-parameter of a class template has a default
+      //   template-argument, each subsequent template-parameter shall either
+      //   have a default template-argument supplied or be a template parameter
+      //   pack.
+      Diag((*NewParam)->getLocation(),
+           diag::err_template_param_default_arg_missing);
+      Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
+      Invalid = true;
+      RemoveDefaultArguments = true;
+    }
+
+    // If we have an old template parameter list that we're merging
+    // in, move on to the next parameter.
+    if (OldParams)
+      ++OldParam;
+  }
+
+  // We were missing some default arguments at the end of the list, so remove
+  // all of the default arguments.
+  if (RemoveDefaultArguments) {
+    for (TemplateParameterList::iterator NewParam = NewParams->begin(),
+                                      NewParamEnd = NewParams->end();
+         NewParam != NewParamEnd; ++NewParam) {
+      if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
+        TTP->removeDefaultArgument();
+      else if (NonTypeTemplateParmDecl *NTTP
+                                = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
+        NTTP->removeDefaultArgument();
+      else
+        cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
+    }
+  }
+
+  return Invalid;
+}
+
+namespace {
+
+/// A class which looks for a use of a certain level of template
+/// parameter.
+struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
+  typedef RecursiveASTVisitor<DependencyChecker> super;
+
+  unsigned Depth;
+  bool Match;
+
+  DependencyChecker(TemplateParameterList *Params) : Match(false) {
+    NamedDecl *ND = Params->getParam(0);
+    if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
+      Depth = PD->getDepth();
+    } else if (NonTypeTemplateParmDecl *PD =
+                 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
+      Depth = PD->getDepth();
+    } else {
+      Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
+    }
+  }
+
+  bool Matches(unsigned ParmDepth) {
+    if (ParmDepth >= Depth) {
+      Match = true;
+      return true;
+    }
+    return false;
+  }
+
+  bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
+    return !Matches(T->getDepth());
+  }
+
+  bool TraverseTemplateName(TemplateName N) {
+    if (TemplateTemplateParmDecl *PD =
+          dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
+      if (Matches(PD->getDepth())) return false;
+    return super::TraverseTemplateName(N);
+  }
+
+  bool VisitDeclRefExpr(DeclRefExpr *E) {
+    if (NonTypeTemplateParmDecl *PD =
+          dyn_cast<NonTypeTemplateParmDecl>(E->getDecl())) {
+      if (PD->getDepth() == Depth) {
+        Match = true;
+        return false;
+      }
+    }
+    return super::VisitDeclRefExpr(E);
+  }
+  
+  bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
+    return TraverseType(T->getInjectedSpecializationType());
+  }
+};
+}
+
+/// Determines whether a given type depends on the given parameter
+/// list.
+static bool
+DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
+  DependencyChecker Checker(Params);
+  Checker.TraverseType(T);
+  return Checker.Match;
+}
+
+// Find the source range corresponding to the named type in the given
+// nested-name-specifier, if any.
+static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
+                                                       QualType T,
+                                                       const CXXScopeSpec &SS) {
+  NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
+  while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
+    if (const Type *CurType = NNS->getAsType()) {
+      if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
+        return NNSLoc.getTypeLoc().getSourceRange();
+    } else
+      break;
+    
+    NNSLoc = NNSLoc.getPrefix();
+  }
+  
+  return SourceRange();
+}
+
+/// \brief Match the given template parameter lists to the given scope
+/// specifier, returning the template parameter list that applies to the
+/// name.
+///
+/// \param DeclStartLoc the start of the declaration that has a scope
+/// specifier or a template parameter list.
+///
+/// \param DeclLoc The location of the declaration itself.
+///
+/// \param SS the scope specifier that will be matched to the given template
+/// parameter lists. This scope specifier precedes a qualified name that is
+/// being declared.
+///
+/// \param ParamLists the template parameter lists, from the outermost to the
+/// innermost template parameter lists.
+///
+/// \param NumParamLists the number of template parameter lists in ParamLists.
+///
+/// \param IsFriend Whether to apply the slightly different rules for
+/// matching template parameters to scope specifiers in friend
+/// declarations.
+///
+/// \param IsExplicitSpecialization will be set true if the entity being
+/// declared is an explicit specialization, false otherwise.
+///
+/// \returns the template parameter list, if any, that corresponds to the
+/// name that is preceded by the scope specifier @p SS. This template
+/// parameter list may have template parameters (if we're declaring a
+/// template) or may have no template parameters (if we're declaring a
+/// template specialization), or may be NULL (if what we're declaring isn't
+/// itself a template).
+TemplateParameterList *
+Sema::MatchTemplateParametersToScopeSpecifier(SourceLocation DeclStartLoc,
+                                              SourceLocation DeclLoc,
+                                              const CXXScopeSpec &SS,
+                                          TemplateParameterList **ParamLists,
+                                              unsigned NumParamLists,
+                                              bool IsFriend,
+                                              bool &IsExplicitSpecialization,
+                                              bool &Invalid) {
+  IsExplicitSpecialization = false;
+  Invalid = false;
+  
+  // The sequence of nested types to which we will match up the template
+  // parameter lists. We first build this list by starting with the type named
+  // by the nested-name-specifier and walking out until we run out of types.
+  SmallVector<QualType, 4> NestedTypes;
+  QualType T;
+  if (SS.getScopeRep()) {
+    if (CXXRecordDecl *Record 
+              = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
+      T = Context.getTypeDeclType(Record);
+    else
+      T = QualType(SS.getScopeRep()->getAsType(), 0);
+  }
+  
+  // If we found an explicit specialization that prevents us from needing
+  // 'template<>' headers, this will be set to the location of that
+  // explicit specialization.
+  SourceLocation ExplicitSpecLoc;
+  
+  while (!T.isNull()) {
+    NestedTypes.push_back(T);
+    
+    // Retrieve the parent of a record type.
+    if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
+      // If this type is an explicit specialization, we're done.
+      if (ClassTemplateSpecializationDecl *Spec
+          = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
+        if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) && 
+            Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
+          ExplicitSpecLoc = Spec->getLocation();
+          break;
+        }
+      } else if (Record->getTemplateSpecializationKind()
+                                                == TSK_ExplicitSpecialization) {
+        ExplicitSpecLoc = Record->getLocation();
+        break;
+      }
+      
+      if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
+        T = Context.getTypeDeclType(Parent);
+      else
+        T = QualType();
+      continue;
+    } 
+    
+    if (const TemplateSpecializationType *TST
+                                     = T->getAs<TemplateSpecializationType>()) {
+      if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
+        if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
+          T = Context.getTypeDeclType(Parent);
+        else
+          T = QualType();
+        continue;        
+      }
+    }
+    
+    // Look one step prior in a dependent template specialization type.
+    if (const DependentTemplateSpecializationType *DependentTST
+                          = T->getAs<DependentTemplateSpecializationType>()) {
+      if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
+        T = QualType(NNS->getAsType(), 0);
+      else
+        T = QualType();
+      continue;
+    }
+    
+    // Look one step prior in a dependent name type.
+    if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
+      if (NestedNameSpecifier *NNS = DependentName->getQualifier())
+        T = QualType(NNS->getAsType(), 0);
+      else
+        T = QualType();
+      continue;
+    }
+    
+    // Retrieve the parent of an enumeration type.
+    if (const EnumType *EnumT = T->getAs<EnumType>()) {
+      // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
+      // check here.
+      EnumDecl *Enum = EnumT->getDecl();
+      
+      // Get to the parent type.
+      if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
+        T = Context.getTypeDeclType(Parent);
+      else
+        T = QualType();      
+      continue;
+    }
+
+    T = QualType();
+  }
+  // Reverse the nested types list, since we want to traverse from the outermost
+  // to the innermost while checking template-parameter-lists.
+  std::reverse(NestedTypes.begin(), NestedTypes.end());
+
+  // C++0x [temp.expl.spec]p17:
+  //   A member or a member template may be nested within many
+  //   enclosing class templates. In an explicit specialization for
+  //   such a member, the member declaration shall be preceded by a
+  //   template<> for each enclosing class template that is
+  //   explicitly specialized.
+  bool SawNonEmptyTemplateParameterList = false;
+  unsigned ParamIdx = 0;
+  for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
+       ++TypeIdx) {
+    T = NestedTypes[TypeIdx];
+    
+    // Whether we expect a 'template<>' header.
+    bool NeedEmptyTemplateHeader = false;
+
+    // Whether we expect a template header with parameters.
+    bool NeedNonemptyTemplateHeader = false;
+    
+    // For a dependent type, the set of template parameters that we
+    // expect to see.
+    TemplateParameterList *ExpectedTemplateParams = 0;
+
+    // C++0x [temp.expl.spec]p15:
+    //   A member or a member template may be nested within many enclosing 
+    //   class templates. In an explicit specialization for such a member, the 
+    //   member declaration shall be preceded by a template<> for each 
+    //   enclosing class template that is explicitly specialized.
+    if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
+      if (ClassTemplatePartialSpecializationDecl *Partial
+            = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
+        ExpectedTemplateParams = Partial->getTemplateParameters();
+        NeedNonemptyTemplateHeader = true;
+      } else if (Record->isDependentType()) {
+        if (Record->getDescribedClassTemplate()) {
+          ExpectedTemplateParams = Record->getDescribedClassTemplate()
+                                                      ->getTemplateParameters();
+          NeedNonemptyTemplateHeader = true;
+        }
+      } else if (ClassTemplateSpecializationDecl *Spec
+                     = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
+        // C++0x [temp.expl.spec]p4:
+        //   Members of an explicitly specialized class template are defined
+        //   in the same manner as members of normal classes, and not using 
+        //   the template<> syntax. 
+        if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
+          NeedEmptyTemplateHeader = true;
+        else
+          continue;
+      } else if (Record->getTemplateSpecializationKind()) {
+        if (Record->getTemplateSpecializationKind() 
+                                                != TSK_ExplicitSpecialization &&
+            TypeIdx == NumTypes - 1)
+          IsExplicitSpecialization = true;
+        
+        continue;
+      }
+    } else if (const TemplateSpecializationType *TST
+                                     = T->getAs<TemplateSpecializationType>()) {
+      if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {        
+        ExpectedTemplateParams = Template->getTemplateParameters();
+        NeedNonemptyTemplateHeader = true;        
+      }
+    } else if (T->getAs<DependentTemplateSpecializationType>()) {
+      // FIXME:  We actually could/should check the template arguments here
+      // against the corresponding template parameter list.
+      NeedNonemptyTemplateHeader = false;
+    } 
+    
+    // C++ [temp.expl.spec]p16:
+    //   In an explicit specialization declaration for a member of a class 
+    //   template or a member template that ap- pears in namespace scope, the 
+    //   member template and some of its enclosing class templates may remain 
+    //   unspecialized, except that the declaration shall not explicitly 
+    //   specialize a class member template if its en- closing class templates 
+    //   are not explicitly specialized as well.
+    if (ParamIdx < NumParamLists) {
+      if (ParamLists[ParamIdx]->size() == 0) {
+        if (SawNonEmptyTemplateParameterList) {
+          Diag(DeclLoc, diag::err_specialize_member_of_template)
+            << ParamLists[ParamIdx]->getSourceRange();
+          Invalid = true;
+          IsExplicitSpecialization = false;
+          return 0;
+        }
+      } else
+        SawNonEmptyTemplateParameterList = true;
+    }
+    
+    if (NeedEmptyTemplateHeader) {
+      // If we're on the last of the types, and we need a 'template<>' header
+      // here, then it's an explicit specialization.
+      if (TypeIdx == NumTypes - 1)
+        IsExplicitSpecialization = true;
+      
+      if (ParamIdx < NumParamLists) {
+        if (ParamLists[ParamIdx]->size() > 0) {
+          // The header has template parameters when it shouldn't. Complain.
+          Diag(ParamLists[ParamIdx]->getTemplateLoc(), 
+               diag::err_template_param_list_matches_nontemplate)
+            << T
+            << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
+                           ParamLists[ParamIdx]->getRAngleLoc())
+            << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
+          Invalid = true;
+          return 0;
+        }
+        
+        // Consume this template header.
+        ++ParamIdx;
+        continue;
+      } 
+      
+      if (!IsFriend) {
+        // We don't have a template header, but we should.
+        SourceLocation ExpectedTemplateLoc;
+        if (NumParamLists > 0)
+          ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
+        else
+          ExpectedTemplateLoc = DeclStartLoc;
+
+        Diag(DeclLoc, diag::err_template_spec_needs_header)
+          << getRangeOfTypeInNestedNameSpecifier(Context, T, SS)
+          << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
+      }
+      
+      continue;
+    }
+    
+    if (NeedNonemptyTemplateHeader) {
+      // In friend declarations we can have template-ids which don't
+      // depend on the corresponding template parameter lists.  But
+      // assume that empty parameter lists are supposed to match this
+      // template-id.
+      if (IsFriend && T->isDependentType()) {
+        if (ParamIdx < NumParamLists &&
+            DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
+          ExpectedTemplateParams = 0;
+        else 
+          continue;
+      }
+
+      if (ParamIdx < NumParamLists) {
+        // Check the template parameter list, if we can.        
+        if (ExpectedTemplateParams &&
+            !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
+                                            ExpectedTemplateParams,
+                                            true, TPL_TemplateMatch))
+          Invalid = true;
+        
+        if (!Invalid &&
+            CheckTemplateParameterList(ParamLists[ParamIdx], 0,
+                                       TPC_ClassTemplateMember))
+          Invalid = true;
+        
+        ++ParamIdx;
+        continue;
+      }
+      
+      Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
+        << T
+        << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
+      Invalid = true;
+      continue;
+    }
+  }
+    
+  // If there were at least as many template-ids as there were template
+  // parameter lists, then there are no template parameter lists remaining for
+  // the declaration itself.
+  if (ParamIdx >= NumParamLists)
+    return 0;
+
+  // If there were too many template parameter lists, complain about that now.
+  if (ParamIdx < NumParamLists - 1) {
+    bool HasAnyExplicitSpecHeader = false;
+    bool AllExplicitSpecHeaders = true;
+    for (unsigned I = ParamIdx; I != NumParamLists - 1; ++I) {
+      if (ParamLists[I]->size() == 0)
+        HasAnyExplicitSpecHeader = true;
+      else
+        AllExplicitSpecHeaders = false;
+    }
+    
+    Diag(ParamLists[ParamIdx]->getTemplateLoc(),
+         AllExplicitSpecHeaders? diag::warn_template_spec_extra_headers
+                               : diag::err_template_spec_extra_headers)
+      << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
+                     ParamLists[NumParamLists - 2]->getRAngleLoc());
+
+    // If there was a specialization somewhere, such that 'template<>' is
+    // not required, and there were any 'template<>' headers, note where the
+    // specialization occurred.
+    if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader)
+      Diag(ExplicitSpecLoc, 
+           diag::note_explicit_template_spec_does_not_need_header)
+        << NestedTypes.back();
+    
+    // We have a template parameter list with no corresponding scope, which
+    // means that the resulting template declaration can't be instantiated
+    // properly (we'll end up with dependent nodes when we shouldn't).
+    if (!AllExplicitSpecHeaders)
+      Invalid = true;
+  }
+
+  // C++ [temp.expl.spec]p16:
+  //   In an explicit specialization declaration for a member of a class 
+  //   template or a member template that ap- pears in namespace scope, the 
+  //   member template and some of its enclosing class templates may remain 
+  //   unspecialized, except that the declaration shall not explicitly 
+  //   specialize a class member template if its en- closing class templates 
+  //   are not explicitly specialized as well.
+  if (ParamLists[NumParamLists - 1]->size() == 0 && 
+      SawNonEmptyTemplateParameterList) {
+    Diag(DeclLoc, diag::err_specialize_member_of_template)
+      << ParamLists[ParamIdx]->getSourceRange();
+    Invalid = true;
+    IsExplicitSpecialization = false;
+    return 0;
+  }
+  
+  // Return the last template parameter list, which corresponds to the
+  // entity being declared.
+  return ParamLists[NumParamLists - 1];
+}
+
+void Sema::NoteAllFoundTemplates(TemplateName Name) {
+  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
+    Diag(Template->getLocation(), diag::note_template_declared_here)
+      << (isa<FunctionTemplateDecl>(Template)? 0
+          : isa<ClassTemplateDecl>(Template)? 1
+          : isa<TypeAliasTemplateDecl>(Template)? 2
+          : 3)
+      << Template->getDeclName();
+    return;
+  }
+  
+  if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
+    for (OverloadedTemplateStorage::iterator I = OST->begin(), 
+                                          IEnd = OST->end();
+         I != IEnd; ++I)
+      Diag((*I)->getLocation(), diag::note_template_declared_here)
+        << 0 << (*I)->getDeclName();
+    
+    return;
+  }
+}
+
+QualType Sema::CheckTemplateIdType(TemplateName Name,
+                                   SourceLocation TemplateLoc,
+                                   TemplateArgumentListInfo &TemplateArgs) {
+  DependentTemplateName *DTN
+    = Name.getUnderlying().getAsDependentTemplateName();
+  if (DTN && DTN->isIdentifier())
+    // When building a template-id where the template-name is dependent,
+    // assume the template is a type template. Either our assumption is
+    // correct, or the code is ill-formed and will be diagnosed when the
+    // dependent name is substituted.
+    return Context.getDependentTemplateSpecializationType(ETK_None,
+                                                          DTN->getQualifier(),
+                                                          DTN->getIdentifier(),
+                                                          TemplateArgs);
+
+  TemplateDecl *Template = Name.getAsTemplateDecl();
+  if (!Template || isa<FunctionTemplateDecl>(Template)) {
+    // We might have a substituted template template parameter pack. If so,
+    // build a template specialization type for it.
+    if (Name.getAsSubstTemplateTemplateParmPack())
+      return Context.getTemplateSpecializationType(Name, TemplateArgs);
+
+    Diag(TemplateLoc, diag::err_template_id_not_a_type)
+      << Name;
+    NoteAllFoundTemplates(Name);
+    return QualType();
+  }
+
+  // Check that the template argument list is well-formed for this
+  // template.
+  SmallVector<TemplateArgument, 4> Converted;
+  bool ExpansionIntoFixedList = false;
+  if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
+                                false, Converted, &ExpansionIntoFixedList))
+    return QualType();
+
+  QualType CanonType;
+
+  bool InstantiationDependent = false;
+  TypeAliasTemplateDecl *AliasTemplate = 0;
+  if (!ExpansionIntoFixedList &&
+      (AliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Template))) {
+    // Find the canonical type for this type alias template specialization.
+    TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
+    if (Pattern->isInvalidDecl())
+      return QualType();
+
+    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                      Converted.data(), Converted.size());
+
+    // Only substitute for the innermost template argument list.
+    MultiLevelTemplateArgumentList TemplateArgLists;
+    TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
+    unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
+    for (unsigned I = 0; I < Depth; ++I)
+      TemplateArgLists.addOuterTemplateArguments(0, 0);
+
+    InstantiatingTemplate Inst(*this, TemplateLoc, Template);
+    CanonType = SubstType(Pattern->getUnderlyingType(),
+                          TemplateArgLists, AliasTemplate->getLocation(),
+                          AliasTemplate->getDeclName());
+    if (CanonType.isNull())
+      return QualType();
+  } else if (Name.isDependent() ||
+             TemplateSpecializationType::anyDependentTemplateArguments(
+               TemplateArgs, InstantiationDependent)) {
+    // This class template specialization is a dependent
+    // type. Therefore, its canonical type is another class template
+    // specialization type that contains all of the converted
+    // arguments in canonical form. This ensures that, e.g., A<T> and
+    // A<T, T> have identical types when A is declared as:
+    //
+    //   template<typename T, typename U = T> struct A;
+    TemplateName CanonName = Context.getCanonicalTemplateName(Name);
+    CanonType = Context.getTemplateSpecializationType(CanonName,
+                                                      Converted.data(),
+                                                      Converted.size());
+
+    // FIXME: CanonType is not actually the canonical type, and unfortunately
+    // it is a TemplateSpecializationType that we will never use again.
+    // In the future, we need to teach getTemplateSpecializationType to only
+    // build the canonical type and return that to us.
+    CanonType = Context.getCanonicalType(CanonType);
+
+    // This might work out to be a current instantiation, in which
+    // case the canonical type needs to be the InjectedClassNameType.
+    //
+    // TODO: in theory this could be a simple hashtable lookup; most
+    // changes to CurContext don't change the set of current
+    // instantiations.
+    if (isa<ClassTemplateDecl>(Template)) {
+      for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
+        // If we get out to a namespace, we're done.
+        if (Ctx->isFileContext()) break;
+
+        // If this isn't a record, keep looking.
+        CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
+        if (!Record) continue;
+
+        // Look for one of the two cases with InjectedClassNameTypes
+        // and check whether it's the same template.
+        if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
+            !Record->getDescribedClassTemplate())
+          continue;
+
+        // Fetch the injected class name type and check whether its
+        // injected type is equal to the type we just built.
+        QualType ICNT = Context.getTypeDeclType(Record);
+        QualType Injected = cast<InjectedClassNameType>(ICNT)
+          ->getInjectedSpecializationType();
+
+        if (CanonType != Injected->getCanonicalTypeInternal())
+          continue;
+
+        // If so, the canonical type of this TST is the injected
+        // class name type of the record we just found.
+        assert(ICNT.isCanonical());
+        CanonType = ICNT;
+        break;
+      }
+    }
+  } else if (ClassTemplateDecl *ClassTemplate
+               = dyn_cast<ClassTemplateDecl>(Template)) {
+    // Find the class template specialization declaration that
+    // corresponds to these arguments.
+    void *InsertPos = 0;
+    ClassTemplateSpecializationDecl *Decl
+      = ClassTemplate->findSpecialization(Converted.data(), Converted.size(),
+                                          InsertPos);
+    if (!Decl) {
+      // This is the first time we have referenced this class template
+      // specialization. Create the canonical declaration and add it to
+      // the set of specializations.
+      Decl = ClassTemplateSpecializationDecl::Create(Context,
+                            ClassTemplate->getTemplatedDecl()->getTagKind(),
+                                                ClassTemplate->getDeclContext(),
+                            ClassTemplate->getTemplatedDecl()->getLocStart(),
+                                                ClassTemplate->getLocation(),
+                                                     ClassTemplate,
+                                                     Converted.data(),
+                                                     Converted.size(), 0);
+      ClassTemplate->AddSpecialization(Decl, InsertPos);
+      Decl->setLexicalDeclContext(CurContext);
+    }
+
+    CanonType = Context.getTypeDeclType(Decl);
+    assert(isa<RecordType>(CanonType) &&
+           "type of non-dependent specialization is not a RecordType");
+  }
+
+  // Build the fully-sugared type for this class template
+  // specialization, which refers back to the class template
+  // specialization we created or found.
+  return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
+}
+
+TypeResult
+Sema::ActOnTemplateIdType(CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
+                          TemplateTy TemplateD, SourceLocation TemplateLoc,
+                          SourceLocation LAngleLoc,
+                          ASTTemplateArgsPtr TemplateArgsIn,
+                          SourceLocation RAngleLoc,
+                          bool IsCtorOrDtorName) {
+  if (SS.isInvalid())
+    return true;
+
+  TemplateName Template = TemplateD.getAsVal<TemplateName>();
+
+  // Translate the parser's template argument list in our AST format.
+  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
+  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
+
+  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
+    QualType T
+      = Context.getDependentTemplateSpecializationType(ETK_None,
+                                                       DTN->getQualifier(),
+                                                       DTN->getIdentifier(),
+                                                       TemplateArgs);
+    // Build type-source information.
+    TypeLocBuilder TLB;
+    DependentTemplateSpecializationTypeLoc SpecTL
+      = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
+    SpecTL.setElaboratedKeywordLoc(SourceLocation());
+    SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
+    SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+    SpecTL.setTemplateNameLoc(TemplateLoc);
+    SpecTL.setLAngleLoc(LAngleLoc);
+    SpecTL.setRAngleLoc(RAngleLoc);
+    for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
+      SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
+    return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
+  }
+  
+  QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
+  TemplateArgsIn.release();
+
+  if (Result.isNull())
+    return true;
+
+  // Build type-source information.
+  TypeLocBuilder TLB;
+  TemplateSpecializationTypeLoc SpecTL
+    = TLB.push<TemplateSpecializationTypeLoc>(Result);
+  SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+  SpecTL.setTemplateNameLoc(TemplateLoc);
+  SpecTL.setLAngleLoc(LAngleLoc);
+  SpecTL.setRAngleLoc(RAngleLoc);
+  for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
+    SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
+
+  // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
+  // constructor or destructor name (in such a case, the scope specifier
+  // will be attached to the enclosing Decl or Expr node).
+  if (SS.isNotEmpty() && !IsCtorOrDtorName) {
+    // Create an elaborated-type-specifier containing the nested-name-specifier.
+    Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
+    ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
+    ElabTL.setElaboratedKeywordLoc(SourceLocation());
+    ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
+  }
+  
+  return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
+}
+
+TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
+                                        TypeSpecifierType TagSpec,
+                                        SourceLocation TagLoc,
+                                        CXXScopeSpec &SS,
+                                        SourceLocation TemplateKWLoc,
+                                        TemplateTy TemplateD,
+                                        SourceLocation TemplateLoc,
+                                        SourceLocation LAngleLoc,
+                                        ASTTemplateArgsPtr TemplateArgsIn,
+                                        SourceLocation RAngleLoc) {
+  TemplateName Template = TemplateD.getAsVal<TemplateName>();
+  
+  // Translate the parser's template argument list in our AST format.
+  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
+  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
+  
+  // Determine the tag kind
+  TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
+  ElaboratedTypeKeyword Keyword
+    = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
+
+  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
+    QualType T = Context.getDependentTemplateSpecializationType(Keyword,
+                                                          DTN->getQualifier(), 
+                                                          DTN->getIdentifier(), 
+                                                                TemplateArgs);
+    
+    // Build type-source information.    
+    TypeLocBuilder TLB;
+    DependentTemplateSpecializationTypeLoc SpecTL
+      = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
+    SpecTL.setElaboratedKeywordLoc(TagLoc);
+    SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
+    SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+    SpecTL.setTemplateNameLoc(TemplateLoc);
+    SpecTL.setLAngleLoc(LAngleLoc);
+    SpecTL.setRAngleLoc(RAngleLoc);
+    for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
+      SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
+    return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
+  }
+
+  if (TypeAliasTemplateDecl *TAT =
+        dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
+    // C++0x [dcl.type.elab]p2:
+    //   If the identifier resolves to a typedef-name or the simple-template-id
+    //   resolves to an alias template specialization, the
+    //   elaborated-type-specifier is ill-formed.
+    Diag(TemplateLoc, diag::err_tag_reference_non_tag) << 4;
+    Diag(TAT->getLocation(), diag::note_declared_at);
+  }
+  
+  QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
+  if (Result.isNull())
+    return TypeResult(true);
+  
+  // Check the tag kind
+  if (const RecordType *RT = Result->getAs<RecordType>()) {
+    RecordDecl *D = RT->getDecl();
+    
+    IdentifierInfo *Id = D->getIdentifier();
+    assert(Id && "templated class must have an identifier");
+    
+    if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
+                                      TagLoc, *Id)) {
+      Diag(TagLoc, diag::err_use_with_wrong_tag)
+        << Result
+        << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
+      Diag(D->getLocation(), diag::note_previous_use);
+    }
+  }
+
+  // Provide source-location information for the template specialization.
+  TypeLocBuilder TLB;
+  TemplateSpecializationTypeLoc SpecTL
+    = TLB.push<TemplateSpecializationTypeLoc>(Result);
+  SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+  SpecTL.setTemplateNameLoc(TemplateLoc);
+  SpecTL.setLAngleLoc(LAngleLoc);
+  SpecTL.setRAngleLoc(RAngleLoc);
+  for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
+    SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
+
+  // Construct an elaborated type containing the nested-name-specifier (if any)
+  // and tag keyword.
+  Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
+  ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
+  ElabTL.setElaboratedKeywordLoc(TagLoc);
+  ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
+  return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
+}
+
+ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
+                                     SourceLocation TemplateKWLoc,
+                                     LookupResult &R,
+                                     bool RequiresADL,
+                                 const TemplateArgumentListInfo *TemplateArgs) {
+  // FIXME: Can we do any checking at this point? I guess we could check the
+  // template arguments that we have against the template name, if the template
+  // name refers to a single template. That's not a terribly common case,
+  // though.
+  // foo<int> could identify a single function unambiguously
+  // This approach does NOT work, since f<int>(1);
+  // gets resolved prior to resorting to overload resolution
+  // i.e., template<class T> void f(double);
+  //       vs template<class T, class U> void f(U);
+
+  // These should be filtered out by our callers.
+  assert(!R.empty() && "empty lookup results when building templateid");
+  assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
+
+  // We don't want lookup warnings at this point.
+  R.suppressDiagnostics();
+
+  UnresolvedLookupExpr *ULE
+    = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
+                                   SS.getWithLocInContext(Context),
+                                   TemplateKWLoc,
+                                   R.getLookupNameInfo(),
+                                   RequiresADL, TemplateArgs,
+                                   R.begin(), R.end());
+
+  return Owned(ULE);
+}
+
+// We actually only call this from template instantiation.
+ExprResult
+Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
+                                   SourceLocation TemplateKWLoc,
+                                   const DeclarationNameInfo &NameInfo,
+                             const TemplateArgumentListInfo *TemplateArgs) {
+  assert(TemplateArgs || TemplateKWLoc.isValid());
+  DeclContext *DC;
+  if (!(DC = computeDeclContext(SS, false)) ||
+      DC->isDependentContext() ||
+      RequireCompleteDeclContext(SS, DC))
+    return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
+
+  bool MemberOfUnknownSpecialization;
+  LookupResult R(*this, NameInfo, LookupOrdinaryName);
+  LookupTemplateName(R, (Scope*) 0, SS, QualType(), /*Entering*/ false,
+                     MemberOfUnknownSpecialization);
+
+  if (R.isAmbiguous())
+    return ExprError();
+
+  if (R.empty()) {
+    Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_non_template)
+      << NameInfo.getName() << SS.getRange();
+    return ExprError();
+  }
+
+  if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
+    Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
+      << (NestedNameSpecifier*) SS.getScopeRep()
+      << NameInfo.getName() << SS.getRange();
+    Diag(Temp->getLocation(), diag::note_referenced_class_template);
+    return ExprError();
+  }
+
+  return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
+}
+
+/// \brief Form a dependent template name.
+///
+/// This action forms a dependent template name given the template
+/// name and its (presumably dependent) scope specifier. For
+/// example, given "MetaFun::template apply", the scope specifier \p
+/// SS will be "MetaFun::", \p TemplateKWLoc contains the location
+/// of the "template" keyword, and "apply" is the \p Name.
+TemplateNameKind Sema::ActOnDependentTemplateName(Scope *S,
+                                                  CXXScopeSpec &SS,
+                                                  SourceLocation TemplateKWLoc,
+                                                  UnqualifiedId &Name,
+                                                  ParsedType ObjectType,
+                                                  bool EnteringContext,
+                                                  TemplateTy &Result) {
+  if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
+    Diag(TemplateKWLoc,
+         getLangOpts().CPlusPlus0x ?
+           diag::warn_cxx98_compat_template_outside_of_template :
+           diag::ext_template_outside_of_template)
+      << FixItHint::CreateRemoval(TemplateKWLoc);
+
+  DeclContext *LookupCtx = 0;
+  if (SS.isSet())
+    LookupCtx = computeDeclContext(SS, EnteringContext);
+  if (!LookupCtx && ObjectType)
+    LookupCtx = computeDeclContext(ObjectType.get());
+  if (LookupCtx) {
+    // C++0x [temp.names]p5:
+    //   If a name prefixed by the keyword template is not the name of
+    //   a template, the program is ill-formed. [Note: the keyword
+    //   template may not be applied to non-template members of class
+    //   templates. -end note ] [ Note: as is the case with the
+    //   typename prefix, the template prefix is allowed in cases
+    //   where it is not strictly necessary; i.e., when the
+    //   nested-name-specifier or the expression on the left of the ->
+    //   or . is not dependent on a template-parameter, or the use
+    //   does not appear in the scope of a template. -end note]
+    //
+    // Note: C++03 was more strict here, because it banned the use of
+    // the "template" keyword prior to a template-name that was not a
+    // dependent name. C++ DR468 relaxed this requirement (the
+    // "template" keyword is now permitted). We follow the C++0x
+    // rules, even in C++03 mode with a warning, retroactively applying the DR.
+    bool MemberOfUnknownSpecialization;
+    TemplateNameKind TNK = isTemplateName(0, SS, TemplateKWLoc.isValid(), Name,
+                                          ObjectType, EnteringContext, Result,
+                                          MemberOfUnknownSpecialization);
+    if (TNK == TNK_Non_template && LookupCtx->isDependentContext() &&
+        isa<CXXRecordDecl>(LookupCtx) &&
+        (!cast<CXXRecordDecl>(LookupCtx)->hasDefinition() ||
+         cast<CXXRecordDecl>(LookupCtx)->hasAnyDependentBases())) {
+      // This is a dependent template. Handle it below.
+    } else if (TNK == TNK_Non_template) {
+      Diag(Name.getLocStart(),
+           diag::err_template_kw_refers_to_non_template)
+        << GetNameFromUnqualifiedId(Name).getName()
+        << Name.getSourceRange()
+        << TemplateKWLoc;
+      return TNK_Non_template;
+    } else {
+      // We found something; return it.
+      return TNK;
+    }
+  }
+
+  NestedNameSpecifier *Qualifier
+    = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+
+  switch (Name.getKind()) {
+  case UnqualifiedId::IK_Identifier:
+    Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
+                                                              Name.Identifier));
+    return TNK_Dependent_template_name;
+
+  case UnqualifiedId::IK_OperatorFunctionId:
+    Result = TemplateTy::make(Context.getDependentTemplateName(Qualifier,
+                                             Name.OperatorFunctionId.Operator));
+    return TNK_Dependent_template_name;
+
+  case UnqualifiedId::IK_LiteralOperatorId:
+    llvm_unreachable(
+            "We don't support these; Parse shouldn't have allowed propagation");
+
+  default:
+    break;
+  }
+
+  Diag(Name.getLocStart(),
+       diag::err_template_kw_refers_to_non_template)
+    << GetNameFromUnqualifiedId(Name).getName()
+    << Name.getSourceRange()
+    << TemplateKWLoc;
+  return TNK_Non_template;
+}
+
+bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
+                                     const TemplateArgumentLoc &AL,
+                          SmallVectorImpl<TemplateArgument> &Converted) {
+  const TemplateArgument &Arg = AL.getArgument();
+
+  // Check template type parameter.
+  switch(Arg.getKind()) {
+  case TemplateArgument::Type:
+    // C++ [temp.arg.type]p1:
+    //   A template-argument for a template-parameter which is a
+    //   type shall be a type-id.
+    break;
+  case TemplateArgument::Template: {
+    // We have a template type parameter but the template argument
+    // is a template without any arguments.
+    SourceRange SR = AL.getSourceRange();
+    TemplateName Name = Arg.getAsTemplate();
+    Diag(SR.getBegin(), diag::err_template_missing_args)
+      << Name << SR;
+    if (TemplateDecl *Decl = Name.getAsTemplateDecl())
+      Diag(Decl->getLocation(), diag::note_template_decl_here);
+
+    return true;
+  }
+  default: {
+    // We have a template type parameter but the template argument
+    // is not a type.
+    SourceRange SR = AL.getSourceRange();
+    Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
+    Diag(Param->getLocation(), diag::note_template_param_here);
+
+    return true;
+  }
+  }
+
+  if (CheckTemplateArgument(Param, AL.getTypeSourceInfo()))
+    return true;
+
+  // Add the converted template type argument.
+  QualType ArgType = Context.getCanonicalType(Arg.getAsType());
+  
+  // Objective-C ARC:
+  //   If an explicitly-specified template argument type is a lifetime type
+  //   with no lifetime qualifier, the __strong lifetime qualifier is inferred.
+  if (getLangOpts().ObjCAutoRefCount &&
+      ArgType->isObjCLifetimeType() &&
+      !ArgType.getObjCLifetime()) {
+    Qualifiers Qs;
+    Qs.setObjCLifetime(Qualifiers::OCL_Strong);
+    ArgType = Context.getQualifiedType(ArgType, Qs);
+  }
+  
+  Converted.push_back(TemplateArgument(ArgType));
+  return false;
+}
+
+/// \brief Substitute template arguments into the default template argument for
+/// the given template type parameter.
+///
+/// \param SemaRef the semantic analysis object for which we are performing
+/// the substitution.
+///
+/// \param Template the template that we are synthesizing template arguments
+/// for.
+///
+/// \param TemplateLoc the location of the template name that started the
+/// template-id we are checking.
+///
+/// \param RAngleLoc the location of the right angle bracket ('>') that
+/// terminates the template-id.
+///
+/// \param Param the template template parameter whose default we are
+/// substituting into.
+///
+/// \param Converted the list of template arguments provided for template
+/// parameters that precede \p Param in the template parameter list.
+/// \returns the substituted template argument, or NULL if an error occurred.
+static TypeSourceInfo *
+SubstDefaultTemplateArgument(Sema &SemaRef,
+                             TemplateDecl *Template,
+                             SourceLocation TemplateLoc,
+                             SourceLocation RAngleLoc,
+                             TemplateTypeParmDecl *Param,
+                         SmallVectorImpl<TemplateArgument> &Converted) {
+  TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
+
+  // If the argument type is dependent, instantiate it now based
+  // on the previously-computed template arguments.
+  if (ArgType->getType()->isDependentType()) {
+    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                      Converted.data(), Converted.size());
+
+    MultiLevelTemplateArgumentList AllTemplateArgs
+      = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
+
+    Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
+                                     Template, Converted.data(),
+                                     Converted.size(),
+                                     SourceRange(TemplateLoc, RAngleLoc));
+
+    Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
+    ArgType = SemaRef.SubstType(ArgType, AllTemplateArgs,
+                                Param->getDefaultArgumentLoc(),
+                                Param->getDeclName());
+  }
+
+  return ArgType;
+}
+
+/// \brief Substitute template arguments into the default template argument for
+/// the given non-type template parameter.
+///
+/// \param SemaRef the semantic analysis object for which we are performing
+/// the substitution.
+///
+/// \param Template the template that we are synthesizing template arguments
+/// for.
+///
+/// \param TemplateLoc the location of the template name that started the
+/// template-id we are checking.
+///
+/// \param RAngleLoc the location of the right angle bracket ('>') that
+/// terminates the template-id.
+///
+/// \param Param the non-type template parameter whose default we are
+/// substituting into.
+///
+/// \param Converted the list of template arguments provided for template
+/// parameters that precede \p Param in the template parameter list.
+///
+/// \returns the substituted template argument, or NULL if an error occurred.
+static ExprResult
+SubstDefaultTemplateArgument(Sema &SemaRef,
+                             TemplateDecl *Template,
+                             SourceLocation TemplateLoc,
+                             SourceLocation RAngleLoc,
+                             NonTypeTemplateParmDecl *Param,
+                        SmallVectorImpl<TemplateArgument> &Converted) {
+  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                    Converted.data(), Converted.size());
+
+  MultiLevelTemplateArgumentList AllTemplateArgs
+    = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
+
+  Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
+                                   Template, Converted.data(),
+                                   Converted.size(),
+                                   SourceRange(TemplateLoc, RAngleLoc));
+
+  Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
+  EnterExpressionEvaluationContext Unevaluated(SemaRef, Sema::Unevaluated);
+  return SemaRef.SubstExpr(Param->getDefaultArgument(), AllTemplateArgs);
+}
+
+/// \brief Substitute template arguments into the default template argument for
+/// the given template template parameter.
+///
+/// \param SemaRef the semantic analysis object for which we are performing
+/// the substitution.
+///
+/// \param Template the template that we are synthesizing template arguments
+/// for.
+///
+/// \param TemplateLoc the location of the template name that started the
+/// template-id we are checking.
+///
+/// \param RAngleLoc the location of the right angle bracket ('>') that
+/// terminates the template-id.
+///
+/// \param Param the template template parameter whose default we are
+/// substituting into.
+///
+/// \param Converted the list of template arguments provided for template
+/// parameters that precede \p Param in the template parameter list.
+///
+/// \param QualifierLoc Will be set to the nested-name-specifier (with 
+/// source-location information) that precedes the template name.
+///
+/// \returns the substituted template argument, or NULL if an error occurred.
+static TemplateName
+SubstDefaultTemplateArgument(Sema &SemaRef,
+                             TemplateDecl *Template,
+                             SourceLocation TemplateLoc,
+                             SourceLocation RAngleLoc,
+                             TemplateTemplateParmDecl *Param,
+                       SmallVectorImpl<TemplateArgument> &Converted,
+                             NestedNameSpecifierLoc &QualifierLoc) {
+  TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                    Converted.data(), Converted.size());
+
+  MultiLevelTemplateArgumentList AllTemplateArgs
+    = SemaRef.getTemplateInstantiationArgs(Template, &TemplateArgs);
+
+  Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
+                                   Template, Converted.data(),
+                                   Converted.size(),
+                                   SourceRange(TemplateLoc, RAngleLoc));
+
+  Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
+  // Substitute into the nested-name-specifier first, 
+  QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
+  if (QualifierLoc) {
+    QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, 
+                                                       AllTemplateArgs);
+    if (!QualifierLoc)
+      return TemplateName();
+  }
+  
+  return SemaRef.SubstTemplateName(QualifierLoc,
+                      Param->getDefaultArgument().getArgument().getAsTemplate(),
+                              Param->getDefaultArgument().getTemplateNameLoc(),
+                                   AllTemplateArgs);
+}
+
+/// \brief If the given template parameter has a default template
+/// argument, substitute into that default template argument and
+/// return the corresponding template argument.
+TemplateArgumentLoc
+Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
+                                              SourceLocation TemplateLoc,
+                                              SourceLocation RAngleLoc,
+                                              Decl *Param,
+                      SmallVectorImpl<TemplateArgument> &Converted) {
+   if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
+    if (!TypeParm->hasDefaultArgument())
+      return TemplateArgumentLoc();
+
+    TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
+                                                      TemplateLoc,
+                                                      RAngleLoc,
+                                                      TypeParm,
+                                                      Converted);
+    if (DI)
+      return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
+
+    return TemplateArgumentLoc();
+  }
+
+  if (NonTypeTemplateParmDecl *NonTypeParm
+        = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
+    if (!NonTypeParm->hasDefaultArgument())
+      return TemplateArgumentLoc();
+
+    ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
+                                                  TemplateLoc,
+                                                  RAngleLoc,
+                                                  NonTypeParm,
+                                                  Converted);
+    if (Arg.isInvalid())
+      return TemplateArgumentLoc();
+
+    Expr *ArgE = Arg.takeAs<Expr>();
+    return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
+  }
+
+  TemplateTemplateParmDecl *TempTempParm
+    = cast<TemplateTemplateParmDecl>(Param);
+  if (!TempTempParm->hasDefaultArgument())
+    return TemplateArgumentLoc();
+
+
+  NestedNameSpecifierLoc QualifierLoc;
+  TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
+                                                    TemplateLoc,
+                                                    RAngleLoc,
+                                                    TempTempParm,
+                                                    Converted,
+                                                    QualifierLoc);
+  if (TName.isNull())
+    return TemplateArgumentLoc();
+
+  return TemplateArgumentLoc(TemplateArgument(TName),
+                TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
+                TempTempParm->getDefaultArgument().getTemplateNameLoc());
+}
+
+/// \brief Check that the given template argument corresponds to the given
+/// template parameter.
+///
+/// \param Param The template parameter against which the argument will be
+/// checked.
+///
+/// \param Arg The template argument.
+///
+/// \param Template The template in which the template argument resides.
+///
+/// \param TemplateLoc The location of the template name for the template
+/// whose argument list we're matching.
+///
+/// \param RAngleLoc The location of the right angle bracket ('>') that closes
+/// the template argument list.
+///
+/// \param ArgumentPackIndex The index into the argument pack where this
+/// argument will be placed. Only valid if the parameter is a parameter pack.
+///
+/// \param Converted The checked, converted argument will be added to the
+/// end of this small vector.
+///
+/// \param CTAK Describes how we arrived at this particular template argument:
+/// explicitly written, deduced, etc.
+///
+/// \returns true on error, false otherwise.
+bool Sema::CheckTemplateArgument(NamedDecl *Param,
+                                 const TemplateArgumentLoc &Arg,
+                                 NamedDecl *Template,
+                                 SourceLocation TemplateLoc,
+                                 SourceLocation RAngleLoc,
+                                 unsigned ArgumentPackIndex,
+                            SmallVectorImpl<TemplateArgument> &Converted,
+                                 CheckTemplateArgumentKind CTAK) {
+  // Check template type parameters.
+  if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
+    return CheckTemplateTypeArgument(TTP, Arg, Converted);
+
+  // Check non-type template parameters.
+  if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
+    // Do substitution on the type of the non-type template parameter
+    // with the template arguments we've seen thus far.  But if the
+    // template has a dependent context then we cannot substitute yet.
+    QualType NTTPType = NTTP->getType();
+    if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
+      NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
+
+    if (NTTPType->isDependentType() &&
+        !isa<TemplateTemplateParmDecl>(Template) &&
+        !Template->getDeclContext()->isDependentContext()) {
+      // Do substitution on the type of the non-type template parameter.
+      InstantiatingTemplate Inst(*this, TemplateLoc, Template,
+                                 NTTP, Converted.data(), Converted.size(),
+                                 SourceRange(TemplateLoc, RAngleLoc));
+
+      TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                        Converted.data(), Converted.size());
+      NTTPType = SubstType(NTTPType,
+                           MultiLevelTemplateArgumentList(TemplateArgs),
+                           NTTP->getLocation(),
+                           NTTP->getDeclName());
+      // If that worked, check the non-type template parameter type
+      // for validity.
+      if (!NTTPType.isNull())
+        NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
+                                                     NTTP->getLocation());
+      if (NTTPType.isNull())
+        return true;
+    }
+
+    switch (Arg.getArgument().getKind()) {
+    case TemplateArgument::Null:
+      llvm_unreachable("Should never see a NULL template argument here");
+
+    case TemplateArgument::Expression: {
+      TemplateArgument Result;
+      ExprResult Res =
+        CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
+                              Result, CTAK);
+      if (Res.isInvalid())
+        return true;
+
+      Converted.push_back(Result);
+      break;
+    }
+
+    case TemplateArgument::Declaration:
+    case TemplateArgument::Integral:
+      // We've already checked this template argument, so just copy
+      // it to the list of converted arguments.
+      Converted.push_back(Arg.getArgument());
+      break;
+
+    case TemplateArgument::Template:
+    case TemplateArgument::TemplateExpansion:
+      // We were given a template template argument. It may not be ill-formed;
+      // see below.
+      if (DependentTemplateName *DTN
+            = Arg.getArgument().getAsTemplateOrTemplatePattern()
+                                              .getAsDependentTemplateName()) {
+        // We have a template argument such as \c T::template X, which we
+        // parsed as a template template argument. However, since we now
+        // know that we need a non-type template argument, convert this
+        // template name into an expression.
+
+        DeclarationNameInfo NameInfo(DTN->getIdentifier(),
+                                     Arg.getTemplateNameLoc());
+
+        CXXScopeSpec SS;
+        SS.Adopt(Arg.getTemplateQualifierLoc());
+        // FIXME: the template-template arg was a DependentTemplateName,
+        // so it was provided with a template keyword. However, its source
+        // location is not stored in the template argument structure.
+        SourceLocation TemplateKWLoc;
+        ExprResult E = Owned(DependentScopeDeclRefExpr::Create(Context,
+                                                SS.getWithLocInContext(Context),
+                                                               TemplateKWLoc,
+                                                               NameInfo, 0));
+
+        // If we parsed the template argument as a pack expansion, create a
+        // pack expansion expression.
+        if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
+          E = ActOnPackExpansion(E.take(), Arg.getTemplateEllipsisLoc());
+          if (E.isInvalid())
+            return true;
+        }
+
+        TemplateArgument Result;
+        E = CheckTemplateArgument(NTTP, NTTPType, E.take(), Result);
+        if (E.isInvalid())
+          return true;
+
+        Converted.push_back(Result);
+        break;
+      }
+
+      // We have a template argument that actually does refer to a class
+      // template, alias template, or template template parameter, and
+      // therefore cannot be a non-type template argument.
+      Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
+        << Arg.getSourceRange();
+
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+
+    case TemplateArgument::Type: {
+      // We have a non-type template parameter but the template
+      // argument is a type.
+
+      // C++ [temp.arg]p2:
+      //   In a template-argument, an ambiguity between a type-id and
+      //   an expression is resolved to a type-id, regardless of the
+      //   form of the corresponding template-parameter.
+      //
+      // We warn specifically about this case, since it can be rather
+      // confusing for users.
+      QualType T = Arg.getArgument().getAsType();
+      SourceRange SR = Arg.getSourceRange();
+      if (T->isFunctionType())
+        Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
+      else
+        Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+    }
+
+    case TemplateArgument::Pack:
+      llvm_unreachable("Caller must expand template argument packs");
+    }
+
+    return false;
+  }
+
+
+  // Check template template parameters.
+  TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
+
+  // Substitute into the template parameter list of the template
+  // template parameter, since previously-supplied template arguments
+  // may appear within the template template parameter.
+  {
+    // Set up a template instantiation context.
+    LocalInstantiationScope Scope(*this);
+    InstantiatingTemplate Inst(*this, TemplateLoc, Template,
+                               TempParm, Converted.data(), Converted.size(),
+                               SourceRange(TemplateLoc, RAngleLoc));
+
+    TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
+                                      Converted.data(), Converted.size());
+    TempParm = cast_or_null<TemplateTemplateParmDecl>(
+                      SubstDecl(TempParm, CurContext,
+                                MultiLevelTemplateArgumentList(TemplateArgs)));
+    if (!TempParm)
+      return true;
+  }
+
+  switch (Arg.getArgument().getKind()) {
+  case TemplateArgument::Null:
+    llvm_unreachable("Should never see a NULL template argument here");
+
+  case TemplateArgument::Template:
+  case TemplateArgument::TemplateExpansion:
+    if (CheckTemplateArgument(TempParm, Arg))
+      return true;
+
+    Converted.push_back(Arg.getArgument());
+    break;
+
+  case TemplateArgument::Expression:
+  case TemplateArgument::Type:
+    // We have a template template parameter but the template
+    // argument does not refer to a template.
+    Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
+      << getLangOpts().CPlusPlus0x;
+    return true;
+
+  case TemplateArgument::Declaration:
+    llvm_unreachable("Declaration argument with template template parameter");
+  case TemplateArgument::Integral:
+    llvm_unreachable("Integral argument with template template parameter");
+
+  case TemplateArgument::Pack:
+    llvm_unreachable("Caller must expand template argument packs");
+  }
+
+  return false;
+}
+
+/// \brief Diagnose an arity mismatch in the 
+static bool diagnoseArityMismatch(Sema &S, TemplateDecl *Template,
+                                  SourceLocation TemplateLoc,
+                                  TemplateArgumentListInfo &TemplateArgs) {
+  TemplateParameterList *Params = Template->getTemplateParameters();
+  unsigned NumParams = Params->size();
+  unsigned NumArgs = TemplateArgs.size();
+
+  SourceRange Range;
+  if (NumArgs > NumParams)
+    Range = SourceRange(TemplateArgs[NumParams].getLocation(), 
+                        TemplateArgs.getRAngleLoc());
+  S.Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
+    << (NumArgs > NumParams)
+    << (isa<ClassTemplateDecl>(Template)? 0 :
+        isa<FunctionTemplateDecl>(Template)? 1 :
+        isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
+    << Template << Range;
+  S.Diag(Template->getLocation(), diag::note_template_decl_here)
+    << Params->getSourceRange();
+  return true;
+}
+
+/// \brief Check that the given template argument list is well-formed
+/// for specializing the given template.
+bool Sema::CheckTemplateArgumentList(TemplateDecl *Template,
+                                     SourceLocation TemplateLoc,
+                                     TemplateArgumentListInfo &TemplateArgs,
+                                     bool PartialTemplateArgs,
+                          SmallVectorImpl<TemplateArgument> &Converted,
+                                     bool *ExpansionIntoFixedList) {
+  if (ExpansionIntoFixedList)
+    *ExpansionIntoFixedList = false;
+
+  TemplateParameterList *Params = Template->getTemplateParameters();
+  unsigned NumParams = Params->size();
+  unsigned NumArgs = TemplateArgs.size();
+  bool Invalid = false;
+
+  SourceLocation RAngleLoc = TemplateArgs.getRAngleLoc();
+
+  bool HasParameterPack =
+    NumParams > 0 && Params->getParam(NumParams - 1)->isTemplateParameterPack();
+  
+  // C++ [temp.arg]p1:
+  //   [...] The type and form of each template-argument specified in
+  //   a template-id shall match the type and form specified for the
+  //   corresponding parameter declared by the template in its
+  //   template-parameter-list.
+  bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
+  SmallVector<TemplateArgument, 2> ArgumentPack;
+  TemplateParameterList::iterator Param = Params->begin(),
+                               ParamEnd = Params->end();
+  unsigned ArgIdx = 0;
+  LocalInstantiationScope InstScope(*this, true);
+  bool SawPackExpansion = false;
+  while (Param != ParamEnd) {
+    if (ArgIdx < NumArgs) {
+      // If we have an expanded parameter pack, make sure we don't have too
+      // many arguments.
+      // FIXME: This really should fall out from the normal arity checking.
+      if (NonTypeTemplateParmDecl *NTTP
+                                = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
+        if (NTTP->isExpandedParameterPack() &&
+            ArgumentPack.size() >= NTTP->getNumExpansionTypes()) {
+          Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
+            << true
+            << (isa<ClassTemplateDecl>(Template)? 0 :
+                isa<FunctionTemplateDecl>(Template)? 1 :
+                isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
+            << Template;
+          Diag(Template->getLocation(), diag::note_template_decl_here)
+            << Params->getSourceRange();
+          return true;
+        }
+      }
+
+      // Check the template argument we were given.
+      if (CheckTemplateArgument(*Param, TemplateArgs[ArgIdx], Template,
+                                TemplateLoc, RAngleLoc,
+                                ArgumentPack.size(), Converted))
+        return true;
+
+      if ((*Param)->isTemplateParameterPack()) {
+        // The template parameter was a template parameter pack, so take the
+        // deduced argument and place it on the argument pack. Note that we
+        // stay on the same template parameter so that we can deduce more
+        // arguments.
+        ArgumentPack.push_back(Converted.back());
+        Converted.pop_back();
+      } else {
+        // Move to the next template parameter.
+        ++Param;
+      }
+      
+      // If this template argument is a pack expansion, record that fact
+      // and break out; we can't actually check any more.
+      if (TemplateArgs[ArgIdx].getArgument().isPackExpansion()) {
+        SawPackExpansion = true;
+        ++ArgIdx;
+        break;
+      }
+      
+      ++ArgIdx;
+      continue;
+    }
+
+    // If we're checking a partial template argument list, we're done.
+    if (PartialTemplateArgs) {
+      if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
+        Converted.push_back(TemplateArgument::CreatePackCopy(Context,
+                                                         ArgumentPack.data(),
+                                                         ArgumentPack.size()));
+        
+      return Invalid;
+    }
+
+    // If we have a template parameter pack with no more corresponding
+    // arguments, just break out now and we'll fill in the argument pack below.
+    if ((*Param)->isTemplateParameterPack())
+      break;
+    
+    // Check whether we have a default argument.
+    TemplateArgumentLoc Arg;
+
+    // Retrieve the default template argument from the template
+    // parameter. For each kind of template parameter, we substitute the
+    // template arguments provided thus far and any "outer" template arguments
+    // (when the template parameter was part of a nested template) into
+    // the default argument.
+    if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
+      if (!TTP->hasDefaultArgument())
+        return diagnoseArityMismatch(*this, Template, TemplateLoc, 
+                                     TemplateArgs);
+
+      TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
+                                                             Template,
+                                                             TemplateLoc,
+                                                             RAngleLoc,
+                                                             TTP,
+                                                             Converted);
+      if (!ArgType)
+        return true;
+
+      Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
+                                ArgType);
+    } else if (NonTypeTemplateParmDecl *NTTP
+                 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
+      if (!NTTP->hasDefaultArgument())
+        return diagnoseArityMismatch(*this, Template, TemplateLoc, 
+                                     TemplateArgs);
+
+      ExprResult E = SubstDefaultTemplateArgument(*this, Template,
+                                                              TemplateLoc,
+                                                              RAngleLoc,
+                                                              NTTP,
+                                                              Converted);
+      if (E.isInvalid())
+        return true;
+
+      Expr *Ex = E.takeAs<Expr>();
+      Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
+    } else {
+      TemplateTemplateParmDecl *TempParm
+        = cast<TemplateTemplateParmDecl>(*Param);
+
+      if (!TempParm->hasDefaultArgument())
+        return diagnoseArityMismatch(*this, Template, TemplateLoc, 
+                                     TemplateArgs);
+
+      NestedNameSpecifierLoc QualifierLoc;
+      TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
+                                                       TemplateLoc,
+                                                       RAngleLoc,
+                                                       TempParm,
+                                                       Converted,
+                                                       QualifierLoc);
+      if (Name.isNull())
+        return true;
+
+      Arg = TemplateArgumentLoc(TemplateArgument(Name), QualifierLoc,
+                           TempParm->getDefaultArgument().getTemplateNameLoc());
+    }
+
+    // Introduce an instantiation record that describes where we are using
+    // the default template argument.
+    InstantiatingTemplate Instantiating(*this, RAngleLoc, Template, *Param,
+                                        Converted.data(), Converted.size(),
+                                        SourceRange(TemplateLoc, RAngleLoc));
+
+    // Check the default template argument.
+    if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
+                              RAngleLoc, 0, Converted))
+      return true;
+
+    // Core issue 150 (assumed resolution): if this is a template template 
+    // parameter, keep track of the default template arguments from the 
+    // template definition.
+    if (isTemplateTemplateParameter)
+      TemplateArgs.addArgument(Arg);
+    
+    // Move to the next template parameter and argument.
+    ++Param;
+    ++ArgIdx;
+  }
+
+  // If we saw a pack expansion, then directly convert the remaining arguments,
+  // because we don't know what parameters they'll match up with.
+  if (SawPackExpansion) {
+    bool AddToArgumentPack
+      = Param != ParamEnd && (*Param)->isTemplateParameterPack();
+    while (ArgIdx < NumArgs) {
+      if (AddToArgumentPack)
+        ArgumentPack.push_back(TemplateArgs[ArgIdx].getArgument());
+      else
+        Converted.push_back(TemplateArgs[ArgIdx].getArgument());
+      ++ArgIdx;
+    }
+
+    // Push the argument pack onto the list of converted arguments.
+    if (AddToArgumentPack) {
+      if (ArgumentPack.empty())
+        Converted.push_back(TemplateArgument(0, 0));
+      else {
+        Converted.push_back(
+          TemplateArgument::CreatePackCopy(Context,
+                                           ArgumentPack.data(),
+                                           ArgumentPack.size()));
+        ArgumentPack.clear();
+      }      
+    } else if (ExpansionIntoFixedList) {
+      // We have expanded a pack into a fixed list.
+      *ExpansionIntoFixedList = true;
+    }
+
+    return Invalid;
+  }
+
+  // If we have any leftover arguments, then there were too many arguments.
+  // Complain and fail.
+  if (ArgIdx < NumArgs)
+    return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs);
+  
+  // If we have an expanded parameter pack, make sure we don't have too
+  // many arguments.
+  // FIXME: This really should fall out from the normal arity checking.
+  if (Param != ParamEnd) {
+    if (NonTypeTemplateParmDecl *NTTP
+          = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
+      if (NTTP->isExpandedParameterPack() &&
+          ArgumentPack.size() < NTTP->getNumExpansionTypes()) {
+        Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
+          << false
+          << (isa<ClassTemplateDecl>(Template)? 0 :
+              isa<FunctionTemplateDecl>(Template)? 1 :
+              isa<TemplateTemplateParmDecl>(Template)? 2 : 3)
+          << Template;
+        Diag(Template->getLocation(), diag::note_template_decl_here)
+          << Params->getSourceRange();
+        return true;
+      }
+    }
+  }
+  
+  // Form argument packs for each of the parameter packs remaining.
+  while (Param != ParamEnd) {
+    // If we're checking a partial list of template arguments, don't fill
+    // in arguments for non-template parameter packs.
+    if ((*Param)->isTemplateParameterPack()) {
+      if (!HasParameterPack)
+        return true;
+      if (ArgumentPack.empty())
+        Converted.push_back(TemplateArgument(0, 0));
+      else {
+        Converted.push_back(TemplateArgument::CreatePackCopy(Context,
+                                                          ArgumentPack.data(),
+                                                         ArgumentPack.size()));
+        ArgumentPack.clear();
+      }
+    } else if (!PartialTemplateArgs)
+      return diagnoseArityMismatch(*this, Template, TemplateLoc, TemplateArgs);
+
+    ++Param;
+  }
+
+  return Invalid;
+}
+
+namespace {
+  class UnnamedLocalNoLinkageFinder
+    : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
+  {
+    Sema &S;
+    SourceRange SR;
+
+    typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
+
+  public:
+    UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
+
+    bool Visit(QualType T) {
+      return inherited::Visit(T.getTypePtr());
+    }
+
+#define TYPE(Class, Parent) \
+    bool Visit##Class##Type(const Class##Type *);
+#define ABSTRACT_TYPE(Class, Parent) \
+    bool Visit##Class##Type(const Class##Type *) { return false; }
+#define NON_CANONICAL_TYPE(Class, Parent) \
+    bool Visit##Class##Type(const Class##Type *) { return false; }
+#include "clang/AST/TypeNodes.def"
+
+    bool VisitTagDecl(const TagDecl *Tag);
+    bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
+  };
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
+  return Visit(T->getPointeeType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
+                                                    const BlockPointerType* T) {
+  return Visit(T->getPointeeType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
+                                                const LValueReferenceType* T) {
+  return Visit(T->getPointeeType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
+                                                const RValueReferenceType* T) {
+  return Visit(T->getPointeeType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
+                                                  const MemberPointerType* T) {
+  return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
+                                                  const ConstantArrayType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
+                                                 const IncompleteArrayType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
+                                                   const VariableArrayType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
+                                            const DependentSizedArrayType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
+                                         const DependentSizedExtVectorType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
+  return Visit(T->getElementType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
+                                                  const FunctionProtoType* T) {
+  for (FunctionProtoType::arg_type_iterator A = T->arg_type_begin(),
+                                         AEnd = T->arg_type_end();
+       A != AEnd; ++A) {
+    if (Visit(*A))
+      return true;
+  }
+
+  return Visit(T->getResultType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
+                                               const FunctionNoProtoType* T) {
+  return Visit(T->getResultType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
+                                                  const UnresolvedUsingType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
+  return Visit(T->getUnderlyingType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
+                                                    const UnaryTransformType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
+  return Visit(T->getDeducedType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
+  return VisitTagDecl(T->getDecl());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
+  return VisitTagDecl(T->getDecl());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
+                                                 const TemplateTypeParmType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
+                                        const SubstTemplateTypeParmPackType *) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
+                                            const TemplateSpecializationType*) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
+                                              const InjectedClassNameType* T) {
+  return VisitTagDecl(T->getDecl());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
+                                                   const DependentNameType* T) {
+  return VisitNestedNameSpecifier(T->getQualifier());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
+                                 const DependentTemplateSpecializationType* T) {
+  return VisitNestedNameSpecifier(T->getQualifier());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
+                                                   const PackExpansionType* T) {
+  return Visit(T->getPattern());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
+                                                   const ObjCInterfaceType *) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
+                                                const ObjCObjectPointerType *) {
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
+  return Visit(T->getValueType());
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
+  if (Tag->getDeclContext()->isFunctionOrMethod()) {
+    S.Diag(SR.getBegin(),
+           S.getLangOpts().CPlusPlus0x ?
+             diag::warn_cxx98_compat_template_arg_local_type :
+             diag::ext_template_arg_local_type)
+      << S.Context.getTypeDeclType(Tag) << SR;
+    return true;
+  }
+
+  if (!Tag->getDeclName() && !Tag->getTypedefNameForAnonDecl()) {
+    S.Diag(SR.getBegin(),
+           S.getLangOpts().CPlusPlus0x ?
+             diag::warn_cxx98_compat_template_arg_unnamed_type :
+             diag::ext_template_arg_unnamed_type) << SR;
+    S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
+    return true;
+  }
+
+  return false;
+}
+
+bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
+                                                    NestedNameSpecifier *NNS) {
+  if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
+    return true;
+
+  switch (NNS->getKind()) {
+  case NestedNameSpecifier::Identifier:
+  case NestedNameSpecifier::Namespace:
+  case NestedNameSpecifier::NamespaceAlias:
+  case NestedNameSpecifier::Global:
+    return false;
+
+  case NestedNameSpecifier::TypeSpec:
+  case NestedNameSpecifier::TypeSpecWithTemplate:
+    return Visit(QualType(NNS->getAsType(), 0));
+  }
+  llvm_unreachable("Invalid NestedNameSpecifier::Kind!");
+}
+
+
+/// \brief Check a template argument against its corresponding
+/// template type parameter.
+///
+/// This routine implements the semantics of C++ [temp.arg.type]. It
+/// returns true if an error occurred, and false otherwise.
+bool Sema::CheckTemplateArgument(TemplateTypeParmDecl *Param,
+                                 TypeSourceInfo *ArgInfo) {
+  assert(ArgInfo && "invalid TypeSourceInfo");
+  QualType Arg = ArgInfo->getType();
+  SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
+
+  if (Arg->isVariablyModifiedType()) {
+    return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
+  } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
+    return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
+  }
+
+  // C++03 [temp.arg.type]p2:
+  //   A local type, a type with no linkage, an unnamed type or a type
+  //   compounded from any of these types shall not be used as a
+  //   template-argument for a template type-parameter.
+  //
+  // C++11 allows these, and even in C++03 we allow them as an extension with
+  // a warning.
+  if (LangOpts.CPlusPlus0x ?
+     Diags.getDiagnosticLevel(diag::warn_cxx98_compat_template_arg_unnamed_type,
+                              SR.getBegin()) != DiagnosticsEngine::Ignored ||
+      Diags.getDiagnosticLevel(diag::warn_cxx98_compat_template_arg_local_type,
+                               SR.getBegin()) != DiagnosticsEngine::Ignored :
+      Arg->hasUnnamedOrLocalType()) {
+    UnnamedLocalNoLinkageFinder Finder(*this, SR);
+    (void)Finder.Visit(Context.getCanonicalType(Arg));
+  }
+
+  return false;
+}
+
+enum NullPointerValueKind {
+  NPV_NotNullPointer,
+  NPV_NullPointer,
+  NPV_Error
+};
+
+/// \brief Determine whether the given template argument is a null pointer
+/// value of the appropriate type.
+static NullPointerValueKind
+isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
+                                   QualType ParamType, Expr *Arg) {
+  if (Arg->isValueDependent() || Arg->isTypeDependent())
+    return NPV_NotNullPointer;
+  
+  if (!S.getLangOpts().CPlusPlus0x)
+    return NPV_NotNullPointer;
+  
+  // Determine whether we have a constant expression.
+  ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
+  if (ArgRV.isInvalid())
+    return NPV_Error;
+  Arg = ArgRV.take();
+  
+  Expr::EvalResult EvalResult;
+  llvm::SmallVector<PartialDiagnosticAt, 8> Notes;
+  EvalResult.Diag = &Notes;
+  if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
+      EvalResult.HasSideEffects) {
+    SourceLocation DiagLoc = Arg->getExprLoc();
+    
+    // If our only note is the usual "invalid subexpression" note, just point
+    // the caret at its location rather than producing an essentially
+    // redundant note.
+    if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
+        diag::note_invalid_subexpr_in_const_expr) {
+      DiagLoc = Notes[0].first;
+      Notes.clear();
+    }
+    
+    S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
+      << Arg->getType() << Arg->getSourceRange();
+    for (unsigned I = 0, N = Notes.size(); I != N; ++I)
+      S.Diag(Notes[I].first, Notes[I].second);
+    
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return NPV_Error;
+  }
+  
+  // C++11 [temp.arg.nontype]p1:
+  //   - an address constant expression of type std::nullptr_t
+  if (Arg->getType()->isNullPtrType())
+    return NPV_NullPointer;
+  
+  //   - a constant expression that evaluates to a null pointer value (4.10); or
+  //   - a constant expression that evaluates to a null member pointer value
+  //     (4.11); or
+  if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
+      (EvalResult.Val.isMemberPointer() &&
+       !EvalResult.Val.getMemberPointerDecl())) {
+    // If our expression has an appropriate type, we've succeeded.
+    bool ObjCLifetimeConversion;
+    if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
+        S.IsQualificationConversion(Arg->getType(), ParamType, false,
+                                     ObjCLifetimeConversion))
+      return NPV_NullPointer;
+    
+    // The types didn't match, but we know we got a null pointer; complain,
+    // then recover as if the types were correct.
+    S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
+      << Arg->getType() << ParamType << Arg->getSourceRange();
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return NPV_NullPointer;
+  }
+
+  // If we don't have a null pointer value, but we do have a NULL pointer
+  // constant, suggest a cast to the appropriate type.
+  if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
+    std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
+    S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
+      << ParamType
+      << FixItHint::CreateInsertion(Arg->getLocStart(), Code)
+      << FixItHint::CreateInsertion(S.PP.getLocForEndOfToken(Arg->getLocEnd()),
+                                    ")");
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return NPV_NullPointer;
+  }
+  
+  // FIXME: If we ever want to support general, address-constant expressions
+  // as non-type template arguments, we should return the ExprResult here to
+  // be interpreted by the caller.
+  return NPV_NotNullPointer;
+}
+
+/// \brief Checks whether the given template argument is the address
+/// of an object or function according to C++ [temp.arg.nontype]p1.
+static bool
+CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
+                                               NonTypeTemplateParmDecl *Param,
+                                               QualType ParamType,
+                                               Expr *ArgIn,
+                                               TemplateArgument &Converted) {
+  bool Invalid = false;
+  Expr *Arg = ArgIn;
+  QualType ArgType = Arg->getType();
+
+  // If our parameter has pointer type, check for a null template value.
+  if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
+    switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
+    case NPV_NullPointer:
+      Converted = TemplateArgument((Decl *)0);
+      return false;
+
+    case NPV_Error:
+      return true;
+        
+    case NPV_NotNullPointer:
+      break;
+    }
+  }
+  
+  // See through any implicit casts we added to fix the type.
+  Arg = Arg->IgnoreImpCasts();
+
+  // C++ [temp.arg.nontype]p1:
+  //
+  //   A template-argument for a non-type, non-template
+  //   template-parameter shall be one of: [...]
+  //
+  //     -- the address of an object or function with external
+  //        linkage, including function templates and function
+  //        template-ids but excluding non-static class members,
+  //        expressed as & id-expression where the & is optional if
+  //        the name refers to a function or array, or if the
+  //        corresponding template-parameter is a reference; or
+
+  // In C++98/03 mode, give an extension warning on any extra parentheses.
+  // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
+  bool ExtraParens = false;
+  while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
+    if (!Invalid && !ExtraParens) {
+      S.Diag(Arg->getLocStart(),
+             S.getLangOpts().CPlusPlus0x ?
+               diag::warn_cxx98_compat_template_arg_extra_parens :
+               diag::ext_template_arg_extra_parens)
+        << Arg->getSourceRange();
+      ExtraParens = true;
+    }
+
+    Arg = Parens->getSubExpr();
+  }
+
+  while (SubstNonTypeTemplateParmExpr *subst =
+           dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
+    Arg = subst->getReplacement()->IgnoreImpCasts();
+
+  bool AddressTaken = false;
+  SourceLocation AddrOpLoc;
+  if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
+    if (UnOp->getOpcode() == UO_AddrOf) {
+      Arg = UnOp->getSubExpr();
+      AddressTaken = true;
+      AddrOpLoc = UnOp->getOperatorLoc();
+    }
+  }
+
+  if (S.getLangOpts().MicrosoftExt && isa<CXXUuidofExpr>(Arg)) {
+    Converted = TemplateArgument(ArgIn);
+    return false;
+  }
+
+  while (SubstNonTypeTemplateParmExpr *subst =
+           dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
+    Arg = subst->getReplacement()->IgnoreImpCasts();
+
+  // Stop checking the precise nature of the argument if it is value dependent,
+  // it should be checked when instantiated.
+  if (Arg->isValueDependent()) {
+    Converted = TemplateArgument(ArgIn);
+    return false;
+  }
+  
+  DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg);
+  if (!DRE) {
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_not_decl_ref)
+    << Arg->getSourceRange();
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return true;
+  }
+
+  if (!isa<ValueDecl>(DRE->getDecl())) {
+    S.Diag(Arg->getLocStart(),
+           diag::err_template_arg_not_object_or_func_form)
+      << Arg->getSourceRange();
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return true;
+  }
+
+  NamedDecl *Entity = DRE->getDecl();
+
+  // Cannot refer to non-static data members
+  if (FieldDecl *Field = dyn_cast<FieldDecl>(Entity)) {
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_field)
+      << Field << Arg->getSourceRange();
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return true;
+  }
+
+  // Cannot refer to non-static member functions
+  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
+    if (!Method->isStatic()) {
+      S.Diag(Arg->getLocStart(), diag::err_template_arg_method)
+        << Method << Arg->getSourceRange();
+      S.Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+    }
+  }
+
+  FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
+  VarDecl *Var = dyn_cast<VarDecl>(Entity);
+
+  // A non-type template argument must refer to an object or function.
+  if (!Func && !Var) {
+    // We found something, but we don't know specifically what it is.
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_not_object_or_func)
+      << Arg->getSourceRange();
+    S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
+    return true;
+  }
+
+  // Address / reference template args must have external linkage in C++98.
+  if (Entity->getLinkage() == InternalLinkage) {
+    S.Diag(Arg->getLocStart(), S.getLangOpts().CPlusPlus0x ?
+             diag::warn_cxx98_compat_template_arg_object_internal :
+             diag::ext_template_arg_object_internal)
+      << !Func << Entity << Arg->getSourceRange();
+    S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
+      << !Func;
+  } else if (Entity->getLinkage() == NoLinkage) {
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_object_no_linkage)
+      << !Func << Entity << Arg->getSourceRange();
+    S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
+      << !Func;
+    return true;
+  }
+
+  if (Func) {
+    // If the template parameter has pointer type, the function decays.
+    if (ParamType->isPointerType() && !AddressTaken)
+      ArgType = S.Context.getPointerType(Func->getType());
+    else if (AddressTaken && ParamType->isReferenceType()) {
+      // If we originally had an address-of operator, but the
+      // parameter has reference type, complain and (if things look
+      // like they will work) drop the address-of operator.
+      if (!S.Context.hasSameUnqualifiedType(Func->getType(),
+                                            ParamType.getNonReferenceType())) {
+        S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
+          << ParamType;
+        S.Diag(Param->getLocation(), diag::note_template_param_here);
+        return true;
+      }
+
+      S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
+        << ParamType
+        << FixItHint::CreateRemoval(AddrOpLoc);
+      S.Diag(Param->getLocation(), diag::note_template_param_here);
+
+      ArgType = Func->getType();
+    }
+  } else {
+    // A value of reference type is not an object.
+    if (Var->getType()->isReferenceType()) {
+      S.Diag(Arg->getLocStart(),
+             diag::err_template_arg_reference_var)
+        << Var->getType() << Arg->getSourceRange();
+      S.Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+    }
+
+    // A template argument must have static storage duration.
+    // FIXME: Ensure this works for thread_local as well as __thread.
+    if (Var->isThreadSpecified()) {
+      S.Diag(Arg->getLocStart(), diag::err_template_arg_thread_local)
+        << Arg->getSourceRange();
+      S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
+      return true;
+    }
+
+    // If the template parameter has pointer type, we must have taken
+    // the address of this object.
+    if (ParamType->isReferenceType()) {
+      if (AddressTaken) {
+        // If we originally had an address-of operator, but the
+        // parameter has reference type, complain and (if things look
+        // like they will work) drop the address-of operator.
+        if (!S.Context.hasSameUnqualifiedType(Var->getType(),
+                                            ParamType.getNonReferenceType())) {
+          S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
+            << ParamType;
+          S.Diag(Param->getLocation(), diag::note_template_param_here);
+          return true;
+        }
+
+        S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
+          << ParamType
+          << FixItHint::CreateRemoval(AddrOpLoc);
+        S.Diag(Param->getLocation(), diag::note_template_param_here);
+
+        ArgType = Var->getType();
+      }
+    } else if (!AddressTaken && ParamType->isPointerType()) {
+      if (Var->getType()->isArrayType()) {
+        // Array-to-pointer decay.
+        ArgType = S.Context.getArrayDecayedType(Var->getType());
+      } else {
+        // If the template parameter has pointer type but the address of
+        // this object was not taken, complain and (possibly) recover by
+        // taking the address of the entity.
+        ArgType = S.Context.getPointerType(Var->getType());
+        if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
+          S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
+            << ParamType;
+          S.Diag(Param->getLocation(), diag::note_template_param_here);
+          return true;
+        }
+
+        S.Diag(Arg->getLocStart(), diag::err_template_arg_not_address_of)
+          << ParamType
+          << FixItHint::CreateInsertion(Arg->getLocStart(), "&");
+
+        S.Diag(Param->getLocation(), diag::note_template_param_here);
+      }
+    }
+  }
+
+  bool ObjCLifetimeConversion;
+  if (ParamType->isPointerType() &&
+      !ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
+      S.IsQualificationConversion(ArgType, ParamType, false, 
+                                  ObjCLifetimeConversion)) {
+    // For pointer-to-object types, qualification conversions are
+    // permitted.
+  } else {
+    if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
+      if (!ParamRef->getPointeeType()->isFunctionType()) {
+        // C++ [temp.arg.nontype]p5b3:
+        //   For a non-type template-parameter of type reference to
+        //   object, no conversions apply. The type referred to by the
+        //   reference may be more cv-qualified than the (otherwise
+        //   identical) type of the template- argument. The
+        //   template-parameter is bound directly to the
+        //   template-argument, which shall be an lvalue.
+
+        // FIXME: Other qualifiers?
+        unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
+        unsigned ArgQuals = ArgType.getCVRQualifiers();
+
+        if ((ParamQuals | ArgQuals) != ParamQuals) {
+          S.Diag(Arg->getLocStart(),
+                 diag::err_template_arg_ref_bind_ignores_quals)
+            << ParamType << Arg->getType()
+            << Arg->getSourceRange();
+          S.Diag(Param->getLocation(), diag::note_template_param_here);
+          return true;
+        }
+      }
+    }
+
+    // At this point, the template argument refers to an object or
+    // function with external linkage. We now need to check whether the
+    // argument and parameter types are compatible.
+    if (!S.Context.hasSameUnqualifiedType(ArgType,
+                                          ParamType.getNonReferenceType())) {
+      // We can't perform this conversion or binding.
+      if (ParamType->isReferenceType())
+        S.Diag(Arg->getLocStart(), diag::err_template_arg_no_ref_bind)
+          << ParamType << ArgIn->getType() << Arg->getSourceRange();
+      else
+        S.Diag(Arg->getLocStart(),  diag::err_template_arg_not_convertible)
+          << ArgIn->getType() << ParamType << Arg->getSourceRange();
+      S.Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+    }
+  }
+
+  // Create the template argument.
+  Converted = TemplateArgument(Entity->getCanonicalDecl());
+  S.MarkAnyDeclReferenced(Arg->getLocStart(), Entity);
+  return false;
+}
+
+/// \brief Checks whether the given template argument is a pointer to
+/// member constant according to C++ [temp.arg.nontype]p1.
+static bool CheckTemplateArgumentPointerToMember(Sema &S,
+                                                 NonTypeTemplateParmDecl *Param,
+                                                 QualType ParamType,
+                                                 Expr *&ResultArg,
+                                                 TemplateArgument &Converted) {
+  bool Invalid = false;
+
+  // Check for a null pointer value.
+  Expr *Arg = ResultArg;
+  switch (isNullPointerValueTemplateArgument(S, Param, ParamType, Arg)) {
+  case NPV_Error:
+    return true;
+  case NPV_NullPointer:
+    Converted = TemplateArgument((Decl *)0);
+    return false;
+  case NPV_NotNullPointer:
+    break;
+  }
+
+  bool ObjCLifetimeConversion;
+  if (S.IsQualificationConversion(Arg->getType(),
+                                  ParamType.getNonReferenceType(),
+                                  false, ObjCLifetimeConversion)) {
+    Arg = S.ImpCastExprToType(Arg, ParamType, CK_NoOp,
+                              Arg->getValueKind()).take();
+    ResultArg = Arg;
+  } else if (!S.Context.hasSameUnqualifiedType(Arg->getType(),
+                ParamType.getNonReferenceType())) {
+    // We can't perform this conversion.
+    S.Diag(Arg->getLocStart(), diag::err_template_arg_not_convertible)
+      << Arg->getType() << ParamType << Arg->getSourceRange();
+    S.Diag(Param->getLocation(), diag::note_template_param_here);
+    return true;
+  }
+
+  // See through any implicit casts we added to fix the type.
+  while (ImplicitCastExpr *Cast = dyn_cast<ImplicitCastExpr>(Arg))
+    Arg = Cast->getSubExpr();
+
+  // C++ [temp.arg.nontype]p1:
+  //
+  //   A template-argument for a non-type, non-template
+  //   template-parameter shall be one of: [...]
+  //
+  //     -- a pointer to member expressed as described in 5.3.1.
+  DeclRefExpr *DRE = 0;
+
+  // In C++98/03 mode, give an extension warning on any extra parentheses.
+  // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
+  bool ExtraParens = false;
+  while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
+    if (!Invalid && !ExtraParens) {
+      S.Diag(Arg->getLocStart(),
+             S.getLangOpts().CPlusPlus0x ?
+               diag::warn_cxx98_compat_template_arg_extra_parens :
+               diag::ext_template_arg_extra_parens)
+        << Arg->getSourceRange();
+      ExtraParens = true;
+    }
+
+    Arg = Parens->getSubExpr();
+  }
+
+  while (SubstNonTypeTemplateParmExpr *subst =
+           dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
+    Arg = subst->getReplacement()->IgnoreImpCasts();
+
+  // A pointer-to-member constant written &Class::member.
+  if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
+    if (UnOp->getOpcode() == UO_AddrOf) {
+      DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
+      if (DRE && !DRE->getQualifier())
+        DRE = 0;
+    }
+  }
+  // A constant of pointer-to-member type.
+  else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
+    if (ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl())) {
+      if (VD->getType()->isMemberPointerType()) {
+        if (isa<NonTypeTemplateParmDecl>(VD) ||
+            (isa<VarDecl>(VD) &&
+             S.Context.getCanonicalType(VD->getType()).isConstQualified())) {
+          if (Arg->isTypeDependent() || Arg->isValueDependent())
+            Converted = TemplateArgument(Arg);
+          else
+            Converted = TemplateArgument(VD->getCanonicalDecl());
+          return Invalid;
+        }
+      }
+    }
+
+    DRE = 0;
+  }
+
+  if (!DRE)
+    return S.Diag(Arg->getLocStart(),
+                  diag::err_template_arg_not_pointer_to_member_form)
+      << Arg->getSourceRange();
+
+  if (isa<FieldDecl>(DRE->getDecl()) || isa<CXXMethodDecl>(DRE->getDecl())) {
+    assert((isa<FieldDecl>(DRE->getDecl()) ||
+            !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
+           "Only non-static member pointers can make it here");
+
+    // Okay: this is the address of a non-static member, and therefore
+    // a member pointer constant.
+    if (Arg->isTypeDependent() || Arg->isValueDependent())
+      Converted = TemplateArgument(Arg);
+    else
+      Converted = TemplateArgument(DRE->getDecl()->getCanonicalDecl());
+    return Invalid;
+  }
+
+  // We found something else, but we don't know specifically what it is.
+  S.Diag(Arg->getLocStart(),
+         diag::err_template_arg_not_pointer_to_member_form)
+    << Arg->getSourceRange();
+  S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
+  return true;
+}
+
+/// \brief Check a template argument against its corresponding
+/// non-type template parameter.
+///
+/// This routine implements the semantics of C++ [temp.arg.nontype].
+/// If an error occurred, it returns ExprError(); otherwise, it
+/// returns the converted template argument. \p
+/// InstantiatedParamType is the type of the non-type template
+/// parameter after it has been instantiated.
+ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
+                                       QualType InstantiatedParamType, Expr *Arg,
+                                       TemplateArgument &Converted,
+                                       CheckTemplateArgumentKind CTAK) {
+  SourceLocation StartLoc = Arg->getLocStart();
+
+  // If either the parameter has a dependent type or the argument is
+  // type-dependent, there's nothing we can check now.
+  if (InstantiatedParamType->isDependentType() || Arg->isTypeDependent()) {
+    // FIXME: Produce a cloned, canonical expression?
+    Converted = TemplateArgument(Arg);
+    return Owned(Arg);
+  }
+
+  // C++ [temp.arg.nontype]p5:
+  //   The following conversions are performed on each expression used
+  //   as a non-type template-argument. If a non-type
+  //   template-argument cannot be converted to the type of the
+  //   corresponding template-parameter then the program is
+  //   ill-formed.
+  QualType ParamType = InstantiatedParamType;
+  if (ParamType->isIntegralOrEnumerationType()) {
+    // C++11:
+    //   -- for a non-type template-parameter of integral or
+    //      enumeration type, conversions permitted in a converted
+    //      constant expression are applied.
+    //
+    // C++98:
+    //   -- for a non-type template-parameter of integral or
+    //      enumeration type, integral promotions (4.5) and integral
+    //      conversions (4.7) are applied.
+
+    if (CTAK == CTAK_Deduced &&
+        !Context.hasSameUnqualifiedType(ParamType, Arg->getType())) {
+      // C++ [temp.deduct.type]p17:
+      //   If, in the declaration of a function template with a non-type
+      //   template-parameter, the non-type template-parameter is used
+      //   in an expression in the function parameter-list and, if the
+      //   corresponding template-argument is deduced, the
+      //   template-argument type shall match the type of the
+      //   template-parameter exactly, except that a template-argument
+      //   deduced from an array bound may be of any integral type.
+      Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
+        << Arg->getType().getUnqualifiedType()
+        << ParamType.getUnqualifiedType();
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return ExprError();
+    }
+
+    if (getLangOpts().CPlusPlus0x) {
+      // We can't check arbitrary value-dependent arguments.
+      // FIXME: If there's no viable conversion to the template parameter type,
+      // we should be able to diagnose that prior to instantiation.
+      if (Arg->isValueDependent()) {
+        Converted = TemplateArgument(Arg);
+        return Owned(Arg);
+      }
+
+      // C++ [temp.arg.nontype]p1:
+      //   A template-argument for a non-type, non-template template-parameter
+      //   shall be one of:
+      //
+      //     -- for a non-type template-parameter of integral or enumeration
+      //        type, a converted constant expression of the type of the
+      //        template-parameter; or
+      llvm::APSInt Value;
+      ExprResult ArgResult =
+        CheckConvertedConstantExpression(Arg, ParamType, Value,
+                                         CCEK_TemplateArg);
+      if (ArgResult.isInvalid())
+        return ExprError();
+
+      // Widen the argument value to sizeof(parameter type). This is almost
+      // always a no-op, except when the parameter type is bool. In
+      // that case, this may extend the argument from 1 bit to 8 bits.
+      QualType IntegerType = ParamType;
+      if (const EnumType *Enum = IntegerType->getAs<EnumType>())
+        IntegerType = Enum->getDecl()->getIntegerType();
+      Value = Value.extOrTrunc(Context.getTypeSize(IntegerType));
+
+      Converted = TemplateArgument(Value, Context.getCanonicalType(ParamType));
+      return ArgResult;
+    }
+
+    ExprResult ArgResult = DefaultLvalueConversion(Arg);
+    if (ArgResult.isInvalid())
+      return ExprError();
+    Arg = ArgResult.take();
+
+    QualType ArgType = Arg->getType();
+
+    // C++ [temp.arg.nontype]p1:
+    //   A template-argument for a non-type, non-template
+    //   template-parameter shall be one of:
+    //
+    //     -- an integral constant-expression of integral or enumeration
+    //        type; or
+    //     -- the name of a non-type template-parameter; or
+    SourceLocation NonConstantLoc;
+    llvm::APSInt Value;
+    if (!ArgType->isIntegralOrEnumerationType()) {
+      Diag(Arg->getLocStart(),
+           diag::err_template_arg_not_integral_or_enumeral)
+        << ArgType << Arg->getSourceRange();
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return ExprError();
+    } else if (!Arg->isValueDependent()) {
+      Arg = VerifyIntegerConstantExpression(Arg, &Value,
+        PDiag(diag::err_template_arg_not_ice) << ArgType, false).take();
+      if (!Arg)
+        return ExprError();
+    }
+
+    // From here on out, all we care about are the unqualified forms
+    // of the parameter and argument types.
+    ParamType = ParamType.getUnqualifiedType();
+    ArgType = ArgType.getUnqualifiedType();
+
+    // Try to convert the argument to the parameter's type.
+    if (Context.hasSameType(ParamType, ArgType)) {
+      // Okay: no conversion necessary
+    } else if (ParamType->isBooleanType()) {
+      // This is an integral-to-boolean conversion.
+      Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).take();
+    } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
+               !ParamType->isEnumeralType()) {
+      // This is an integral promotion or conversion.
+      Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).take();
+    } else {
+      // We can't perform this conversion.
+      Diag(Arg->getLocStart(),
+           diag::err_template_arg_not_convertible)
+        << Arg->getType() << InstantiatedParamType << Arg->getSourceRange();
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return ExprError();
+    }
+
+    // Add the value of this argument to the list of converted
+    // arguments. We use the bitwidth and signedness of the template
+    // parameter.
+    if (Arg->isValueDependent()) {
+      // The argument is value-dependent. Create a new
+      // TemplateArgument with the converted expression.
+      Converted = TemplateArgument(Arg);
+      return Owned(Arg);
+    }
+
+    QualType IntegerType = Context.getCanonicalType(ParamType);
+    if (const EnumType *Enum = IntegerType->getAs<EnumType>())
+      IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
+
+    if (ParamType->isBooleanType()) {
+      // Value must be zero or one.
+      Value = Value != 0;
+      unsigned AllowedBits = Context.getTypeSize(IntegerType);
+      if (Value.getBitWidth() != AllowedBits)
+        Value = Value.extOrTrunc(AllowedBits);
+      Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
+    } else {
+      llvm::APSInt OldValue = Value;
+      
+      // Coerce the template argument's value to the value it will have
+      // based on the template parameter's type.
+      unsigned AllowedBits = Context.getTypeSize(IntegerType);
+      if (Value.getBitWidth() != AllowedBits)
+        Value = Value.extOrTrunc(AllowedBits);
+      Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
+      
+      // Complain if an unsigned parameter received a negative value.
+      if (IntegerType->isUnsignedIntegerOrEnumerationType()
+               && (OldValue.isSigned() && OldValue.isNegative())) {
+        Diag(Arg->getLocStart(), diag::warn_template_arg_negative)
+          << OldValue.toString(10) << Value.toString(10) << Param->getType()
+          << Arg->getSourceRange();
+        Diag(Param->getLocation(), diag::note_template_param_here);
+      }
+      
+      // Complain if we overflowed the template parameter's type.
+      unsigned RequiredBits;
+      if (IntegerType->isUnsignedIntegerOrEnumerationType())
+        RequiredBits = OldValue.getActiveBits();
+      else if (OldValue.isUnsigned())
+        RequiredBits = OldValue.getActiveBits() + 1;
+      else
+        RequiredBits = OldValue.getMinSignedBits();
+      if (RequiredBits > AllowedBits) {
+        Diag(Arg->getLocStart(),
+             diag::warn_template_arg_too_large)
+          << OldValue.toString(10) << Value.toString(10) << Param->getType()
+          << Arg->getSourceRange();
+        Diag(Param->getLocation(), diag::note_template_param_here);
+      }
+    }
+
+    Converted = TemplateArgument(Value,
+                                 ParamType->isEnumeralType() 
+                                   ? Context.getCanonicalType(ParamType)
+                                   : IntegerType);
+    return Owned(Arg);
+  }
+
+  QualType ArgType = Arg->getType();
+  DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
+
+  // Handle pointer-to-function, reference-to-function, and
+  // pointer-to-member-function all in (roughly) the same way.
+  if (// -- For a non-type template-parameter of type pointer to
+      //    function, only the function-to-pointer conversion (4.3) is
+      //    applied. If the template-argument represents a set of
+      //    overloaded functions (or a pointer to such), the matching
+      //    function is selected from the set (13.4).
+      (ParamType->isPointerType() &&
+       ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
+      // -- For a non-type template-parameter of type reference to
+      //    function, no conversions apply. If the template-argument
+      //    represents a set of overloaded functions, the matching
+      //    function is selected from the set (13.4).
+      (ParamType->isReferenceType() &&
+       ParamType->getAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
+      // -- For a non-type template-parameter of type pointer to
+      //    member function, no conversions apply. If the
+      //    template-argument represents a set of overloaded member
+      //    functions, the matching member function is selected from
+      //    the set (13.4).
+      (ParamType->isMemberPointerType() &&
+       ParamType->getAs<MemberPointerType>()->getPointeeType()
+         ->isFunctionType())) {
+
+    if (Arg->getType() == Context.OverloadTy) {
+      if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
+                                                                true,
+                                                                FoundResult)) {
+        if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
+          return ExprError();
+
+        Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
+        ArgType = Arg->getType();
+      } else
+        return ExprError();
+    }
+
+    if (!ParamType->isMemberPointerType()) {
+      if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
+                                                         ParamType,
+                                                         Arg, Converted))
+        return ExprError();
+      return Owned(Arg);
+    }
+
+    if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
+                                             Converted))
+      return ExprError();
+    return Owned(Arg);
+  }
+
+  if (ParamType->isPointerType()) {
+    //   -- for a non-type template-parameter of type pointer to
+    //      object, qualification conversions (4.4) and the
+    //      array-to-pointer conversion (4.2) are applied.
+    // C++0x also allows a value of std::nullptr_t.
+    assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&
+           "Only object pointers allowed here");
+
+    if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
+                                                       ParamType,
+                                                       Arg, Converted))
+      return ExprError();
+    return Owned(Arg);
+  }
+
+  if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
+    //   -- For a non-type template-parameter of type reference to
+    //      object, no conversions apply. The type referred to by the
+    //      reference may be more cv-qualified than the (otherwise
+    //      identical) type of the template-argument. The
+    //      template-parameter is bound directly to the
+    //      template-argument, which must be an lvalue.
+    assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&
+           "Only object references allowed here");
+
+    if (Arg->getType() == Context.OverloadTy) {
+      if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
+                                                 ParamRefType->getPointeeType(),
+                                                                true,
+                                                                FoundResult)) {
+        if (DiagnoseUseOfDecl(Fn, Arg->getLocStart()))
+          return ExprError();
+
+        Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
+        ArgType = Arg->getType();
+      } else
+        return ExprError();
+    }
+
+    if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
+                                                       ParamType,
+                                                       Arg, Converted))
+      return ExprError();
+    return Owned(Arg);
+  }
+
+  // Deal with parameters of type std::nullptr_t.
+  if (ParamType->isNullPtrType()) {
+    if (Arg->isTypeDependent() || Arg->isValueDependent()) {
+      Converted = TemplateArgument(Arg);
+      return Owned(Arg);
+    }
+    
+    switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
+    case NPV_NotNullPointer:
+      Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
+        << Arg->getType() << ParamType;
+      Diag(Param->getLocation(), diag::note_template_param_here);
+      return ExprError();
+      
+    case NPV_Error:
+      return ExprError();
+      
+    case NPV_NullPointer:
+      Converted = TemplateArgument((Decl *)0);
+      return Owned(Arg);;
+    }
+  }
+
+  //     -- For a non-type template-parameter of type pointer to data
+  //        member, qualification conversions (4.4) are applied.
+  assert(ParamType->isMemberPointerType() && "Only pointers to members remain");
+
+  if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
+                                           Converted))
+    return ExprError();
+  return Owned(Arg);
+}
+
+/// \brief Check a template argument against its corresponding
+/// template template parameter.
+///
+/// This routine implements the semantics of C++ [temp.arg.template].
+/// It returns true if an error occurred, and false otherwise.
+bool Sema::CheckTemplateArgument(TemplateTemplateParmDecl *Param,
+                                 const TemplateArgumentLoc &Arg) {
+  TemplateName Name = Arg.getArgument().getAsTemplate();
+  TemplateDecl *Template = Name.getAsTemplateDecl();
+  if (!Template) {
+    // Any dependent template name is fine.
+    assert(Name.isDependent() && "Non-dependent template isn't a declaration?");
+    return false;
+  }
+
+  // C++0x [temp.arg.template]p1:
+  //   A template-argument for a template template-parameter shall be
+  //   the name of a class template or an alias template, expressed as an
+  //   id-expression. When the template-argument names a class template, only
+  //   primary class templates are considered when matching the
+  //   template template argument with the corresponding parameter;
+  //   partial specializations are not considered even if their
+  //   parameter lists match that of the template template parameter.
+  //
+  // Note that we also allow template template parameters here, which
+  // will happen when we are dealing with, e.g., class template
+  // partial specializations.
+  if (!isa<ClassTemplateDecl>(Template) &&
+      !isa<TemplateTemplateParmDecl>(Template) &&
+      !isa<TypeAliasTemplateDecl>(Template)) {
+    assert(isa<FunctionTemplateDecl>(Template) &&
+           "Only function templates are possible here");
+    Diag(Arg.getLocation(), diag::err_template_arg_not_class_template);
+    Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
+      << Template;
+  }
+
+  return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
+                                         Param->getTemplateParameters(),
+                                         true,
+                                         TPL_TemplateTemplateArgumentMatch,
+                                         Arg.getLocation());
+}
+
+/// \brief Given a non-type template argument that refers to a
+/// declaration and the type of its corresponding non-type template
+/// parameter, produce an expression that properly refers to that
+/// declaration.
+ExprResult
+Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
+                                              QualType ParamType,
+                                              SourceLocation Loc) {
+  assert(Arg.getKind() == TemplateArgument::Declaration &&
+         "Only declaration template arguments permitted here");
+  
+  // For a NULL non-type template argument, return nullptr casted to the
+  // parameter's type.
+  if (!Arg.getAsDecl()) {
+    return ImpCastExprToType(
+             new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
+                             ParamType,
+                             ParamType->getAs<MemberPointerType>()
+                               ? CK_NullToMemberPointer
+                               : CK_NullToPointer);
+  }
+  
+  ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
+
+  if (VD->getDeclContext()->isRecord() &&
+      (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD))) {
+    // If the value is a class member, we might have a pointer-to-member.
+    // Determine whether the non-type template template parameter is of
+    // pointer-to-member type. If so, we need to build an appropriate
+    // expression for a pointer-to-member, since a "normal" DeclRefExpr
+    // would refer to the member itself.
+    if (ParamType->isMemberPointerType()) {
+      QualType ClassType
+        = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
+      NestedNameSpecifier *Qualifier
+        = NestedNameSpecifier::Create(Context, 0, false,
+                                      ClassType.getTypePtr());
+      CXXScopeSpec SS;
+      SS.MakeTrivial(Context, Qualifier, Loc);
+
+      // The actual value-ness of this is unimportant, but for
+      // internal consistency's sake, references to instance methods
+      // are r-values.
+      ExprValueKind VK = VK_LValue;
+      if (isa<CXXMethodDecl>(VD) && cast<CXXMethodDecl>(VD)->isInstance())
+        VK = VK_RValue;
+
+      ExprResult RefExpr = BuildDeclRefExpr(VD,
+                                            VD->getType().getNonReferenceType(),
+                                            VK,
+                                            Loc,
+                                            &SS);
+      if (RefExpr.isInvalid())
+        return ExprError();
+
+      RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
+
+      // We might need to perform a trailing qualification conversion, since
+      // the element type on the parameter could be more qualified than the
+      // element type in the expression we constructed.
+      bool ObjCLifetimeConversion;
+      if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
+                                    ParamType.getUnqualifiedType(), false,
+                                    ObjCLifetimeConversion))
+        RefExpr = ImpCastExprToType(RefExpr.take(), ParamType.getUnqualifiedType(), CK_NoOp);
+
+      assert(!RefExpr.isInvalid() &&
+             Context.hasSameType(((Expr*) RefExpr.get())->getType(),
+                                 ParamType.getUnqualifiedType()));
+      return move(RefExpr);
+    }
+  }
+
+  QualType T = VD->getType().getNonReferenceType();
+  if (ParamType->isPointerType()) {
+    // When the non-type template parameter is a pointer, take the
+    // address of the declaration.
+    ExprResult RefExpr = BuildDeclRefExpr(VD, T, VK_LValue, Loc);
+    if (RefExpr.isInvalid())
+      return ExprError();
+
+    if (T->isFunctionType() || T->isArrayType()) {
+      // Decay functions and arrays.
+      RefExpr = DefaultFunctionArrayConversion(RefExpr.take());
+      if (RefExpr.isInvalid())
+        return ExprError();
+
+      return move(RefExpr);
+    }
+
+    // Take the address of everything else
+    return CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
+  }
+
+  ExprValueKind VK = VK_RValue;
+
+  // If the non-type template parameter has reference type, qualify the
+  // resulting declaration reference with the extra qualifiers on the
+  // type that the reference refers to.
+  if (const ReferenceType *TargetRef = ParamType->getAs<ReferenceType>()) {
+    VK = VK_LValue;
+    T = Context.getQualifiedType(T,
+                              TargetRef->getPointeeType().getQualifiers());
+  }
+
+  return BuildDeclRefExpr(VD, T, VK, Loc);
+}
+
+/// \brief Construct a new expression that refers to the given
+/// integral template argument with the given source-location
+/// information.
+///
+/// This routine takes care of the mapping from an integral template
+/// argument (which may have any integral type) to the appropriate
+/// literal value.
+ExprResult
+Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
+                                                  SourceLocation Loc) {
+  assert(Arg.getKind() == TemplateArgument::Integral &&
+         "Operation is only valid for integral template arguments");
+  QualType T = Arg.getIntegralType();
+  if (T->isAnyCharacterType()) {
+    CharacterLiteral::CharacterKind Kind;
+    if (T->isWideCharType())
+      Kind = CharacterLiteral::Wide;
+    else if (T->isChar16Type())
+      Kind = CharacterLiteral::UTF16;
+    else if (T->isChar32Type())
+      Kind = CharacterLiteral::UTF32;
+    else
+      Kind = CharacterLiteral::Ascii;
+
+    return Owned(new (Context) CharacterLiteral(
+                                            Arg.getAsIntegral()->getZExtValue(),
+                                            Kind, T, Loc));
+  }
+
+  if (T->isBooleanType())
+    return Owned(new (Context) CXXBoolLiteralExpr(
+                                            Arg.getAsIntegral()->getBoolValue(),
+                                            T, Loc));
+
+  if (T->isNullPtrType())
+    return Owned(new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc));
+  
+  // If this is an enum type that we're instantiating, we need to use an integer
+  // type the same size as the enumerator.  We don't want to build an
+  // IntegerLiteral with enum type.
+  QualType BT;
+  if (const EnumType *ET = T->getAs<EnumType>())
+    BT = ET->getDecl()->getIntegerType();
+  else
+    BT = T;
+
+  Expr *E = IntegerLiteral::Create(Context, *Arg.getAsIntegral(), BT, Loc);
+  if (T->isEnumeralType()) {
+    // FIXME: This is a hack. We need a better way to handle substituted
+    // non-type template parameters.
+    E = CStyleCastExpr::Create(Context, T, VK_RValue, CK_IntegralCast, E, 0, 
+                               Context.getTrivialTypeSourceInfo(T, Loc),
+                               Loc, Loc);
+  }
+  
+  return Owned(E);
+}
+
+/// \brief Match two template parameters within template parameter lists.
+static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
+                                       bool Complain,
+                                     Sema::TemplateParameterListEqualKind Kind,
+                                       SourceLocation TemplateArgLoc) {
+  // Check the actual kind (type, non-type, template).
+  if (Old->getKind() != New->getKind()) {
+    if (Complain) {
+      unsigned NextDiag = diag::err_template_param_different_kind;
+      if (TemplateArgLoc.isValid()) {
+        S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
+        NextDiag = diag::note_template_param_different_kind;
+      }
+      S.Diag(New->getLocation(), NextDiag)
+        << (Kind != Sema::TPL_TemplateMatch);
+      S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
+        << (Kind != Sema::TPL_TemplateMatch);
+    }
+
+    return false;
+  }
+
+  // Check that both are parameter packs are neither are parameter packs.
+  // However, if we are matching a template template argument to a
+  // template template parameter, the template template parameter can have
+  // a parameter pack where the template template argument does not.
+  if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
+      !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
+        Old->isTemplateParameterPack())) {
+    if (Complain) {
+      unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
+      if (TemplateArgLoc.isValid()) {
+        S.Diag(TemplateArgLoc,
+             diag::err_template_arg_template_params_mismatch);
+        NextDiag = diag::note_template_parameter_pack_non_pack;
+      }
+
+      unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
+                      : isa<NonTypeTemplateParmDecl>(New)? 1
+                      : 2;
+      S.Diag(New->getLocation(), NextDiag)
+        << ParamKind << New->isParameterPack();
+      S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
+        << ParamKind << Old->isParameterPack();
+    }
+
+    return false;
+  }
+
+  // For non-type template parameters, check the type of the parameter.
+  if (NonTypeTemplateParmDecl *OldNTTP
+                                    = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
+    NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
+
+    // If we are matching a template template argument to a template
+    // template parameter and one of the non-type template parameter types
+    // is dependent, then we must wait until template instantiation time
+    // to actually compare the arguments.
+    if (Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
+        (OldNTTP->getType()->isDependentType() ||
+         NewNTTP->getType()->isDependentType()))
+      return true;
+
+    if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
+      if (Complain) {
+        unsigned NextDiag = diag::err_template_nontype_parm_different_type;
+        if (TemplateArgLoc.isValid()) {
+          S.Diag(TemplateArgLoc,
+                 diag::err_template_arg_template_params_mismatch);
+          NextDiag = diag::note_template_nontype_parm_different_type;
+        }
+        S.Diag(NewNTTP->getLocation(), NextDiag)
+          << NewNTTP->getType()
+          << (Kind != Sema::TPL_TemplateMatch);
+        S.Diag(OldNTTP->getLocation(),
+               diag::note_template_nontype_parm_prev_declaration)
+          << OldNTTP->getType();
+      }
+
+      return false;
+    }
+
+    return true;
+  }
+
+  // For template template parameters, check the template parameter types.
+  // The template parameter lists of template template
+  // parameters must agree.
+  if (TemplateTemplateParmDecl *OldTTP
+                                    = dyn_cast<TemplateTemplateParmDecl>(Old)) {
+    TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
+    return S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
+                                            OldTTP->getTemplateParameters(),
+                                            Complain,
+                                        (Kind == Sema::TPL_TemplateMatch
+                                           ? Sema::TPL_TemplateTemplateParmMatch
+                                           : Kind),
+                                            TemplateArgLoc);
+  }
+
+  return true;
+}
+
+/// \brief Diagnose a known arity mismatch when comparing template argument
+/// lists.
+static
+void DiagnoseTemplateParameterListArityMismatch(Sema &S,
+                                                TemplateParameterList *New,
+                                                TemplateParameterList *Old,
+                                      Sema::TemplateParameterListEqualKind Kind,
+                                                SourceLocation TemplateArgLoc) {
+  unsigned NextDiag = diag::err_template_param_list_different_arity;
+  if (TemplateArgLoc.isValid()) {
+    S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
+    NextDiag = diag::note_template_param_list_different_arity;
+  }
+  S.Diag(New->getTemplateLoc(), NextDiag)
+    << (New->size() > Old->size())
+    << (Kind != Sema::TPL_TemplateMatch)
+    << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
+  S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
+    << (Kind != Sema::TPL_TemplateMatch)
+    << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
+}
+
+/// \brief Determine whether the given template parameter lists are
+/// equivalent.
+///
+/// \param New  The new template parameter list, typically written in the
+/// source code as part of a new template declaration.
+///
+/// \param Old  The old template parameter list, typically found via
+/// name lookup of the template declared with this template parameter
+/// list.
+///
+/// \param Complain  If true, this routine will produce a diagnostic if
+/// the template parameter lists are not equivalent.
+///
+/// \param Kind describes how we are to match the template parameter lists.
+///
+/// \param TemplateArgLoc If this source location is valid, then we
+/// are actually checking the template parameter list of a template
+/// argument (New) against the template parameter list of its
+/// corresponding template template parameter (Old). We produce
+/// slightly different diagnostics in this scenario.
+///
+/// \returns True if the template parameter lists are equal, false
+/// otherwise.
+bool
+Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
+                                     TemplateParameterList *Old,
+                                     bool Complain,
+                                     TemplateParameterListEqualKind Kind,
+                                     SourceLocation TemplateArgLoc) {
+  if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
+    if (Complain)
+      DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
+                                                 TemplateArgLoc);
+
+    return false;
+  }
+
+  // C++0x [temp.arg.template]p3:
+  //   A template-argument matches a template template-parameter (call it P)
+  //   when each of the template parameters in the template-parameter-list of
+  //   the template-argument's corresponding class template or alias template
+  //   (call it A) matches the corresponding template parameter in the
+  //   template-parameter-list of P. [...]
+  TemplateParameterList::iterator NewParm = New->begin();
+  TemplateParameterList::iterator NewParmEnd = New->end();
+  for (TemplateParameterList::iterator OldParm = Old->begin(),
+                                    OldParmEnd = Old->end();
+       OldParm != OldParmEnd; ++OldParm) {
+    if (Kind != TPL_TemplateTemplateArgumentMatch ||
+        !(*OldParm)->isTemplateParameterPack()) {
+      if (NewParm == NewParmEnd) {
+        if (Complain)
+          DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
+                                                     TemplateArgLoc);
+
+        return false;
+      }
+
+      if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
+                                      Kind, TemplateArgLoc))
+        return false;
+
+      ++NewParm;
+      continue;
+    }
+
+    // C++0x [temp.arg.template]p3:
+    //   [...] When P's template- parameter-list contains a template parameter
+    //   pack (14.5.3), the template parameter pack will match zero or more
+    //   template parameters or template parameter packs in the
+    //   template-parameter-list of A with the same type and form as the
+    //   template parameter pack in P (ignoring whether those template
+    //   parameters are template parameter packs).
+    for (; NewParm != NewParmEnd; ++NewParm) {
+      if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
+                                      Kind, TemplateArgLoc))
+        return false;
+    }
+  }
+
+  // Make sure we exhausted all of the arguments.
+  if (NewParm != NewParmEnd) {
+    if (Complain)
+      DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
+                                                 TemplateArgLoc);
+
+    return false;
+  }
+
+  return true;
+}
+
+/// \brief Check whether a template can be declared within this scope.
+///
+/// If the template declaration is valid in this scope, returns
+/// false. Otherwise, issues a diagnostic and returns true.
+bool
+Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
+  if (!S)
+    return false;
+
+  // Find the nearest enclosing declaration scope.
+  while ((S->getFlags() & Scope::DeclScope) == 0 ||
+         (S->getFlags() & Scope::TemplateParamScope) != 0)
+    S = S->getParent();
+
+  // C++ [temp]p2:
+  //   A template-declaration can appear only as a namespace scope or
+  //   class scope declaration.
+  DeclContext *Ctx = static_cast<DeclContext *>(S->getEntity());
+  if (Ctx && isa<LinkageSpecDecl>(Ctx) &&
+      cast<LinkageSpecDecl>(Ctx)->getLanguage() != LinkageSpecDecl::lang_cxx)
+    return Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
+             << TemplateParams->getSourceRange();
+
+  while (Ctx && isa<LinkageSpecDecl>(Ctx))
+    Ctx = Ctx->getParent();
+
+  if (Ctx && (Ctx->isFileContext() || Ctx->isRecord()))
+    return false;
+
+  return Diag(TemplateParams->getTemplateLoc(),
+              diag::err_template_outside_namespace_or_class_scope)
+    << TemplateParams->getSourceRange();
+}
+
+/// \brief Determine what kind of template specialization the given declaration
+/// is.
+static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
+  if (!D)
+    return TSK_Undeclared;
+
+  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
+    return Record->getTemplateSpecializationKind();
+  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
+    return Function->getTemplateSpecializationKind();
+  if (VarDecl *Var = dyn_cast<VarDecl>(D))
+    return Var->getTemplateSpecializationKind();
+
+  return TSK_Undeclared;
+}
+
+/// \brief Check whether a specialization is well-formed in the current
+/// context.
+///
+/// This routine determines whether a template specialization can be declared
+/// in the current context (C++ [temp.expl.spec]p2).
+///
+/// \param S the semantic analysis object for which this check is being
+/// performed.
+///
+/// \param Specialized the entity being specialized or instantiated, which
+/// may be a kind of template (class template, function template, etc.) or
+/// a member of a class template (member function, static data member,
+/// member class).
+///
+/// \param PrevDecl the previous declaration of this entity, if any.
+///
+/// \param Loc the location of the explicit specialization or instantiation of
+/// this entity.
+///
+/// \param IsPartialSpecialization whether this is a partial specialization of
+/// a class template.
+///
+/// \returns true if there was an error that we cannot recover from, false
+/// otherwise.
+static bool CheckTemplateSpecializationScope(Sema &S,
+                                             NamedDecl *Specialized,
+                                             NamedDecl *PrevDecl,
+                                             SourceLocation Loc,
+                                             bool IsPartialSpecialization) {
+  // Keep these "kind" numbers in sync with the %select statements in the
+  // various diagnostics emitted by this routine.
+  int EntityKind = 0;
+  if (isa<ClassTemplateDecl>(Specialized))
+    EntityKind = IsPartialSpecialization? 1 : 0;
+  else if (isa<FunctionTemplateDecl>(Specialized))
+    EntityKind = 2;
+  else if (isa<CXXMethodDecl>(Specialized))
+    EntityKind = 3;
+  else if (isa<VarDecl>(Specialized))
+    EntityKind = 4;
+  else if (isa<RecordDecl>(Specialized))
+    EntityKind = 5;
+  else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus0x)
+    EntityKind = 6;
+  else {
+    S.Diag(Loc, diag::err_template_spec_unknown_kind)
+      << S.getLangOpts().CPlusPlus0x;
+    S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
+    return true;
+  }
+
+  // C++ [temp.expl.spec]p2:
+  //   An explicit specialization shall be declared in the namespace
+  //   of which the template is a member, or, for member templates, in
+  //   the namespace of which the enclosing class or enclosing class
+  //   template is a member. An explicit specialization of a member
+  //   function, member class or static data member of a class
+  //   template shall be declared in the namespace of which the class
+  //   template is a member. Such a declaration may also be a
+  //   definition. If the declaration is not a definition, the
+  //   specialization may be defined later in the name- space in which
+  //   the explicit specialization was declared, or in a namespace
+  //   that encloses the one in which the explicit specialization was
+  //   declared.
+  if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
+    S.Diag(Loc, diag::err_template_spec_decl_function_scope)
+      << Specialized;
+    return true;
+  }
+
+  if (S.CurContext->isRecord() && !IsPartialSpecialization) {
+    if (S.getLangOpts().MicrosoftExt) {
+      // Do not warn for class scope explicit specialization during
+      // instantiation, warning was already emitted during pattern
+      // semantic analysis.
+      if (!S.ActiveTemplateInstantiations.size())
+        S.Diag(Loc, diag::ext_function_specialization_in_class)
+          << Specialized;
+    } else {
+      S.Diag(Loc, diag::err_template_spec_decl_class_scope)
+        << Specialized;
+      return true;
+    }
+  }
+
+  if (S.CurContext->isRecord() &&
+      !S.CurContext->Equals(Specialized->getDeclContext())) {
+    // Make sure that we're specializing in the right record context.
+    // Otherwise, things can go horribly wrong.
+    S.Diag(Loc, diag::err_template_spec_decl_class_scope)
+      << Specialized;
+    return true;
+  }
+  
+  // C++ [temp.class.spec]p6:
+  //   A class template partial specialization may be declared or redeclared
+  //   in any namespace scope in which its definition may be defined (14.5.1
+  //   and 14.5.2).
+  bool ComplainedAboutScope = false;
+  DeclContext *SpecializedContext 
+    = Specialized->getDeclContext()->getEnclosingNamespaceContext();
+  DeclContext *DC = S.CurContext->getEnclosingNamespaceContext();
+  if ((!PrevDecl ||
+       getTemplateSpecializationKind(PrevDecl) == TSK_Undeclared ||
+       getTemplateSpecializationKind(PrevDecl) == TSK_ImplicitInstantiation)){
+    // C++ [temp.exp.spec]p2:
+    //   An explicit specialization shall be declared in the namespace of which
+    //   the template is a member, or, for member templates, in the namespace
+    //   of which the enclosing class or enclosing class template is a member.
+    //   An explicit specialization of a member function, member class or
+    //   static data member of a class template shall be declared in the
+    //   namespace of which the class template is a member.
+    //
+    // C++0x [temp.expl.spec]p2:
+    //   An explicit specialization shall be declared in a namespace enclosing
+    //   the specialized template.
+    if (!DC->InEnclosingNamespaceSetOf(SpecializedContext)) {
+      bool IsCPlusPlus0xExtension = DC->Encloses(SpecializedContext);
+      if (isa<TranslationUnitDecl>(SpecializedContext)) {
+        assert(!IsCPlusPlus0xExtension &&
+               "DC encloses TU but isn't in enclosing namespace set");
+        S.Diag(Loc, diag::err_template_spec_decl_out_of_scope_global)
+          << EntityKind << Specialized;
+      } else if (isa<NamespaceDecl>(SpecializedContext)) {
+        int Diag;
+        if (!IsCPlusPlus0xExtension)
+          Diag = diag::err_template_spec_decl_out_of_scope;
+        else if (!S.getLangOpts().CPlusPlus0x)
+          Diag = diag::ext_template_spec_decl_out_of_scope;
+        else
+          Diag = diag::warn_cxx98_compat_template_spec_decl_out_of_scope;
+        S.Diag(Loc, Diag)
+          << EntityKind << Specialized << cast<NamedDecl>(SpecializedContext);
+      }
+
+      S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
+      ComplainedAboutScope =
+        !(IsCPlusPlus0xExtension && S.getLangOpts().CPlusPlus0x);
+    }
+  }
+
+  // Make sure that this redeclaration (or definition) occurs in an enclosing
+  // namespace.
+  // Note that HandleDeclarator() performs this check for explicit
+  // specializations of function templates, static data members, and member
+  // functions, so we skip the check here for those kinds of entities.
+  // FIXME: HandleDeclarator's diagnostics aren't quite as good, though.
+  // Should we refactor that check, so that it occurs later?
+  if (!ComplainedAboutScope && !DC->Encloses(SpecializedContext) &&
+      !(isa<FunctionTemplateDecl>(Specialized) || isa<VarDecl>(Specialized) ||
+        isa<FunctionDecl>(Specialized))) {
+    if (isa<TranslationUnitDecl>(SpecializedContext))
+      S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
+        << EntityKind << Specialized;
+    else if (isa<NamespaceDecl>(SpecializedContext))
+      S.Diag(Loc, diag::err_template_spec_redecl_out_of_scope)
+        << EntityKind << Specialized
+        << cast<NamedDecl>(SpecializedContext);
+
+    S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
+  }
+
+  // FIXME: check for specialization-after-instantiation errors and such.
+
+  return false;
+}
+
+/// \brief Subroutine of Sema::CheckClassTemplatePartialSpecializationArgs
+/// that checks non-type template partial specialization arguments.
+static bool CheckNonTypeClassTemplatePartialSpecializationArgs(Sema &S,
+                                                NonTypeTemplateParmDecl *Param,
+                                                  const TemplateArgument *Args,
+                                                        unsigned NumArgs) {
+  for (unsigned I = 0; I != NumArgs; ++I) {
+    if (Args[I].getKind() == TemplateArgument::Pack) {
+      if (CheckNonTypeClassTemplatePartialSpecializationArgs(S, Param,
+                                                           Args[I].pack_begin(),
+                                                           Args[I].pack_size()))
+        return true;
+
+      continue;
+    }
+
+    Expr *ArgExpr = Args[I].getAsExpr();
+    if (!ArgExpr) {
+      continue;
+    }
+
+    // We can have a pack expansion of any of the bullets below.
+    if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
+      ArgExpr = Expansion->getPattern();
+
+    // Strip off any implicit casts we added as part of type checking.
+    while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
+      ArgExpr = ICE->getSubExpr();
+
+    // C++ [temp.class.spec]p8:
+    //   A non-type argument is non-specialized if it is the name of a
+    //   non-type parameter. All other non-type arguments are
+    //   specialized.
+    //
+    // Below, we check the two conditions that only apply to
+    // specialized non-type arguments, so skip any non-specialized
+    // arguments.
+    if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
+      if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
+        continue;
+
+    // C++ [temp.class.spec]p9:
+    //   Within the argument list of a class template partial
+    //   specialization, the following restrictions apply:
+    //     -- A partially specialized non-type argument expression
+    //        shall not involve a template parameter of the partial
+    //        specialization except when the argument expression is a
+    //        simple identifier.
+    if (ArgExpr->isTypeDependent() || ArgExpr->isValueDependent()) {
+      S.Diag(ArgExpr->getLocStart(),
+           diag::err_dependent_non_type_arg_in_partial_spec)
+        << ArgExpr->getSourceRange();
+      return true;
+    }
+
+    //     -- The type of a template parameter corresponding to a
+    //        specialized non-type argument shall not be dependent on a
+    //        parameter of the specialization.
+    if (Param->getType()->isDependentType()) {
+      S.Diag(ArgExpr->getLocStart(),
+           diag::err_dependent_typed_non_type_arg_in_partial_spec)
+        << Param->getType()
+        << ArgExpr->getSourceRange();
+      S.Diag(Param->getLocation(), diag::note_template_param_here);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+/// \brief Check the non-type template arguments of a class template
+/// partial specialization according to C++ [temp.class.spec]p9.
+///
+/// \param TemplateParams the template parameters of the primary class
+/// template.
+///
+/// \param TemplateArg the template arguments of the class template
+/// partial specialization.
+///
+/// \returns true if there was an error, false otherwise.
+static bool CheckClassTemplatePartialSpecializationArgs(Sema &S,
+                                        TemplateParameterList *TemplateParams,
+                       SmallVectorImpl<TemplateArgument> &TemplateArgs) {
+  const TemplateArgument *ArgList = TemplateArgs.data();
+
+  for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
+    NonTypeTemplateParmDecl *Param
+      = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
+    if (!Param)
+      continue;
+
+    if (CheckNonTypeClassTemplatePartialSpecializationArgs(S, Param,
+                                                           &ArgList[I], 1))
+      return true;
+  }
+
+  return false;
+}
+
+DeclResult
+Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
+                                       TagUseKind TUK,
+                                       SourceLocation KWLoc,
+                                       SourceLocation ModulePrivateLoc,
+                                       CXXScopeSpec &SS,
+                                       TemplateTy TemplateD,
+                                       SourceLocation TemplateNameLoc,
+                                       SourceLocation LAngleLoc,
+                                       ASTTemplateArgsPtr TemplateArgsIn,
+                                       SourceLocation RAngleLoc,
+                                       AttributeList *Attr,
+                               MultiTemplateParamsArg TemplateParameterLists) {
+  assert(TUK != TUK_Reference && "References are not specializations");
+
+  // NOTE: KWLoc is the location of the tag keyword. This will instead
+  // store the location of the outermost template keyword in the declaration.
+  SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
+    ? TemplateParameterLists.get()[0]->getTemplateLoc() : SourceLocation();
+
+  // Find the class template we're specializing
+  TemplateName Name = TemplateD.getAsVal<TemplateName>();
+  ClassTemplateDecl *ClassTemplate
+    = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
+
+  if (!ClassTemplate) {
+    Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
+      << (Name.getAsTemplateDecl() &&
+          isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
+    return true;
+  }
+
+  bool isExplicitSpecialization = false;
+  bool isPartialSpecialization = false;
+
+  // Check the validity of the template headers that introduce this
+  // template.
+  // FIXME: We probably shouldn't complain about these headers for
+  // friend declarations.
+  bool Invalid = false;
+  TemplateParameterList *TemplateParams
+    = MatchTemplateParametersToScopeSpecifier(TemplateNameLoc, 
+                                              TemplateNameLoc,
+                                              SS,
+                        (TemplateParameterList**)TemplateParameterLists.get(),
+                                              TemplateParameterLists.size(),
+                                              TUK == TUK_Friend,
+                                              isExplicitSpecialization,
+                                              Invalid);
+  if (Invalid)
+    return true;
+
+  if (TemplateParams && TemplateParams->size() > 0) {
+    isPartialSpecialization = true;
+
+    if (TUK == TUK_Friend) {
+      Diag(KWLoc, diag::err_partial_specialization_friend)
+        << SourceRange(LAngleLoc, RAngleLoc);
+      return true;
+    }
+
+    // C++ [temp.class.spec]p10:
+    //   The template parameter list of a specialization shall not
+    //   contain default template argument values.
+    for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
+      Decl *Param = TemplateParams->getParam(I);
+      if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
+        if (TTP->hasDefaultArgument()) {
+          Diag(TTP->getDefaultArgumentLoc(),
+               diag::err_default_arg_in_partial_spec);
+          TTP->removeDefaultArgument();
+        }
+      } else if (NonTypeTemplateParmDecl *NTTP
+                   = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
+        if (Expr *DefArg = NTTP->getDefaultArgument()) {
+          Diag(NTTP->getDefaultArgumentLoc(),
+               diag::err_default_arg_in_partial_spec)
+            << DefArg->getSourceRange();
+          NTTP->removeDefaultArgument();
+        }
+      } else {
+        TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
+        if (TTP->hasDefaultArgument()) {
+          Diag(TTP->getDefaultArgument().getLocation(),
+               diag::err_default_arg_in_partial_spec)
+            << TTP->getDefaultArgument().getSourceRange();
+          TTP->removeDefaultArgument();
+        }
+      }
+    }
+  } else if (TemplateParams) {
+    if (TUK == TUK_Friend)
+      Diag(KWLoc, diag::err_template_spec_friend)
+        << FixItHint::CreateRemoval(
+                                SourceRange(TemplateParams->getTemplateLoc(),
+                                            TemplateParams->getRAngleLoc()))
+        << SourceRange(LAngleLoc, RAngleLoc);
+    else
+      isExplicitSpecialization = true;
+  } else if (TUK != TUK_Friend) {
+    Diag(KWLoc, diag::err_template_spec_needs_header)
+      << FixItHint::CreateInsertion(KWLoc, "template<> ");
+    isExplicitSpecialization = true;
+  }
+
+  // Check that the specialization uses the same tag kind as the
+  // original template.
+  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
+  assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
+  if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
+                                    Kind, TUK == TUK_Definition, KWLoc,
+                                    *ClassTemplate->getIdentifier())) {
+    Diag(KWLoc, diag::err_use_with_wrong_tag)
+      << ClassTemplate
+      << FixItHint::CreateReplacement(KWLoc,
+                            ClassTemplate->getTemplatedDecl()->getKindName());
+    Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
+         diag::note_previous_use);
+    Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
+  }
+
+  // Translate the parser's template argument list in our AST format.
+  TemplateArgumentListInfo TemplateArgs;
+  TemplateArgs.setLAngleLoc(LAngleLoc);
+  TemplateArgs.setRAngleLoc(RAngleLoc);
+  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
+
+  // Check for unexpanded parameter packs in any of the template arguments.
+  for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
+    if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
+                                        UPPC_PartialSpecialization))
+      return true;
+
+  // Check that the template argument list is well-formed for this
+  // template.
+  SmallVector<TemplateArgument, 4> Converted;
+  if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
+                                TemplateArgs, false, Converted))
+    return true;
+
+  // Find the class template (partial) specialization declaration that
+  // corresponds to these arguments.
+  if (isPartialSpecialization) {
+    if (CheckClassTemplatePartialSpecializationArgs(*this,
+                                         ClassTemplate->getTemplateParameters(),
+                                         Converted))
+      return true;
+
+    bool InstantiationDependent;
+    if (!Name.isDependent() &&
+        !TemplateSpecializationType::anyDependentTemplateArguments(
+                                             TemplateArgs.getArgumentArray(),
+                                                         TemplateArgs.size(),
+                                                     InstantiationDependent)) {
+      Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
+        << ClassTemplate->getDeclName();
+      isPartialSpecialization = false;
+    }
+  }
+
+  void *InsertPos = 0;
+  ClassTemplateSpecializationDecl *PrevDecl = 0;
+
+  if (isPartialSpecialization)
+    // FIXME: Template parameter list matters, too
+    PrevDecl
+      = ClassTemplate->findPartialSpecialization(Converted.data(),
+                                                 Converted.size(),
+                                                 InsertPos);
+  else
+    PrevDecl
+      = ClassTemplate->findSpecialization(Converted.data(),
+                                          Converted.size(), InsertPos);
+
+  ClassTemplateSpecializationDecl *Specialization = 0;
+
+  // Check whether we can declare a class template specialization in
+  // the current scope.
+  if (TUK != TUK_Friend &&
+      CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
+                                       TemplateNameLoc,
+                                       isPartialSpecialization))
+    return true;
+
+  // The canonical type
+  QualType CanonType;
+  if (PrevDecl &&
+      (PrevDecl->getSpecializationKind() == TSK_Undeclared ||
+               TUK == TUK_Friend)) {
+    // Since the only prior class template specialization with these
+    // arguments was referenced but not declared, or we're only
+    // referencing this specialization as a friend, reuse that
+    // declaration node as our own, updating its source location and
+    // the list of outer template parameters to reflect our new declaration.
+    Specialization = PrevDecl;
+    Specialization->setLocation(TemplateNameLoc);
+    if (TemplateParameterLists.size() > 0) {
+      Specialization->setTemplateParameterListsInfo(Context,
+                                              TemplateParameterLists.size(),
+                    (TemplateParameterList**) TemplateParameterLists.release());
+    }
+    PrevDecl = 0;
+    CanonType = Context.getTypeDeclType(Specialization);
+  } else if (isPartialSpecialization) {
+    // Build the canonical type that describes the converted template
+    // arguments of the class template partial specialization.
+    TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
+    CanonType = Context.getTemplateSpecializationType(CanonTemplate,
+                                                      Converted.data(),
+                                                      Converted.size());
+
+    if (Context.hasSameType(CanonType,
+                        ClassTemplate->getInjectedClassNameSpecialization())) {
+      // C++ [temp.class.spec]p9b3:
+      //
+      //   -- The argument list of the specialization shall not be identical
+      //      to the implicit argument list of the primary template.
+      Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
+        << (TUK == TUK_Definition)
+        << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
+      return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
+                                ClassTemplate->getIdentifier(),
+                                TemplateNameLoc,
+                                Attr,
+                                TemplateParams,
+                                AS_none, /*ModulePrivateLoc=*/SourceLocation(),
+                                TemplateParameterLists.size() - 1,
+                  (TemplateParameterList**) TemplateParameterLists.release());
+    }
+
+    // Create a new class template partial specialization declaration node.
+    ClassTemplatePartialSpecializationDecl *PrevPartial
+      = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
+    unsigned SequenceNumber = PrevPartial? PrevPartial->getSequenceNumber()
+                            : ClassTemplate->getNextPartialSpecSequenceNumber();
+    ClassTemplatePartialSpecializationDecl *Partial
+      = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
+                                             ClassTemplate->getDeclContext(),
+                                                       KWLoc, TemplateNameLoc,
+                                                       TemplateParams,
+                                                       ClassTemplate,
+                                                       Converted.data(),
+                                                       Converted.size(),
+                                                       TemplateArgs,
+                                                       CanonType,
+                                                       PrevPartial,
+                                                       SequenceNumber);
+    SetNestedNameSpecifier(Partial, SS);
+    if (TemplateParameterLists.size() > 1 && SS.isSet()) {
+      Partial->setTemplateParameterListsInfo(Context,
+                                             TemplateParameterLists.size() - 1,
+                    (TemplateParameterList**) TemplateParameterLists.release());
+    }
+
+    if (!PrevPartial)
+      ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
+    Specialization = Partial;
+
+    // If we are providing an explicit specialization of a member class
+    // template specialization, make a note of that.
+    if (PrevPartial && PrevPartial->getInstantiatedFromMember())
+      PrevPartial->setMemberSpecialization();
+
+    // Check that all of the template parameters of the class template
+    // partial specialization are deducible from the template
+    // arguments. If not, this class template partial specialization
+    // will never be used.
+    llvm::SmallBitVector DeducibleParams(TemplateParams->size());
+    MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
+                               TemplateParams->getDepth(),
+                               DeducibleParams);
+
+    if (!DeducibleParams.all()) {
+      unsigned NumNonDeducible = DeducibleParams.size()-DeducibleParams.count();
+      Diag(TemplateNameLoc, diag::warn_partial_specs_not_deducible)
+        << (NumNonDeducible > 1)
+        << SourceRange(TemplateNameLoc, RAngleLoc);
+      for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
+        if (!DeducibleParams[I]) {
+          NamedDecl *Param = cast<NamedDecl>(TemplateParams->getParam(I));
+          if (Param->getDeclName())
+            Diag(Param->getLocation(),
+                 diag::note_partial_spec_unused_parameter)
+              << Param->getDeclName();
+          else
+            Diag(Param->getLocation(),
+                 diag::note_partial_spec_unused_parameter)
+              << "<anonymous>";
+        }
+      }
+    }
+  } else {
+    // Create a new class template specialization declaration node for
+    // this explicit specialization or friend declaration.
+    Specialization
+      = ClassTemplateSpecializationDecl::Create(Context, Kind,
+                                             ClassTemplate->getDeclContext(),
+                                                KWLoc, TemplateNameLoc,
+                                                ClassTemplate,
+                                                Converted.data(),
+                                                Converted.size(),
+                                                PrevDecl);
+    SetNestedNameSpecifier(Specialization, SS);
+    if (TemplateParameterLists.size() > 0) {
+      Specialization->setTemplateParameterListsInfo(Context,
+                                              TemplateParameterLists.size(),
+                    (TemplateParameterList**) TemplateParameterLists.release());
+    }
+
+    if (!PrevDecl)
+      ClassTemplate->AddSpecialization(Specialization, InsertPos);
+
+    CanonType = Context.getTypeDeclType(Specialization);
+  }
+
+  // C++ [temp.expl.spec]p6:
+  //   If a template, a member template or the member of a class template is
+  //   explicitly specialized then that specialization shall be declared
+  //   before the first use of that specialization that would cause an implicit
+  //   instantiation to take place, in every translation unit in which such a
+  //   use occurs; no diagnostic is required.
+  if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
+    bool Okay = false;
+    for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
+      // Is there any previous explicit specialization declaration?
+      if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
+        Okay = true;
+        break;
+      }
+    }
+
+    if (!Okay) {
+      SourceRange Range(TemplateNameLoc, RAngleLoc);
+      Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
+        << Context.getTypeDeclType(Specialization) << Range;
+
+      Diag(PrevDecl->getPointOfInstantiation(),
+           diag::note_instantiation_required_here)
+        << (PrevDecl->getTemplateSpecializationKind()
+                                                != TSK_ImplicitInstantiation);
+      return true;
+    }
+  }
+
+  // If this is not a friend, note that this is an explicit specialization.
+  if (TUK != TUK_Friend)
+    Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
+
+  // Check that this isn't a redefinition of this specialization.
+  if (TUK == TUK_Definition) {
+    if (RecordDecl *Def = Specialization->getDefinition()) {
+      SourceRange Range(TemplateNameLoc, RAngleLoc);
+      Diag(TemplateNameLoc, diag::err_redefinition)
+        << Context.getTypeDeclType(Specialization) << Range;
+      Diag(Def->getLocation(), diag::note_previous_definition);
+      Specialization->setInvalidDecl();
+      return true;
+    }
+  }
+
+  if (Attr)
+    ProcessDeclAttributeList(S, Specialization, Attr);
+
+  if (ModulePrivateLoc.isValid())
+    Diag(Specialization->getLocation(), diag::err_module_private_specialization)
+      << (isPartialSpecialization? 1 : 0)
+      << FixItHint::CreateRemoval(ModulePrivateLoc);
+  
+  // 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
+    = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
+                                                TemplateArgs, CanonType);
+  if (TUK != TUK_Friend) {
+    Specialization->setTypeAsWritten(WrittenTy);
+    Specialization->setTemplateKeywordLoc(TemplateKWLoc);
+  }
+  TemplateArgsIn.release();
+
+  // C++ [temp.expl.spec]p9:
+  //   A template explicit specialization is in the scope of the
+  //   namespace in which the template was defined.
+  //
+  // We actually implement this paragraph where we set the semantic
+  // context (in the creation of the ClassTemplateSpecializationDecl),
+  // but we also maintain the lexical context where the actual
+  // definition occurs.
+  Specialization->setLexicalDeclContext(CurContext);
+
+  // We may be starting the definition of this specialization.
+  if (TUK == TUK_Definition)
+    Specialization->startDefinition();
+
+  if (TUK == TUK_Friend) {
+    FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
+                                            TemplateNameLoc,
+                                            WrittenTy,
+                                            /*FIXME:*/KWLoc);
+    Friend->setAccess(AS_public);
+    CurContext->addDecl(Friend);
+  } else {
+    // Add the specialization into its lexical context, so that it can
+    // be seen when iterating through the list of declarations in that
+    // context. However, specializations are not found by name lookup.
+    CurContext->addDecl(Specialization);
+  }
+  return Specialization;
+}
+
+Decl *Sema::ActOnTemplateDeclarator(Scope *S,
+                              MultiTemplateParamsArg TemplateParameterLists,
+                                    Declarator &D) {
+  return HandleDeclarator(S, D, move(TemplateParameterLists));
+}
+
+Decl *Sema::ActOnStartOfFunctionTemplateDef(Scope *FnBodyScope,
+                               MultiTemplateParamsArg TemplateParameterLists,
+                                            Declarator &D) {
+  assert(getCurFunctionDecl() == 0 && "Function parsing confused");
+  DeclaratorChunk::FunctionTypeInfo &FTI = D.getFunctionTypeInfo();
+
+  if (FTI.hasPrototype) {
+    // FIXME: Diagnose arguments without names in C.
+  }
+
+  Scope *ParentScope = FnBodyScope->getParent();
+
+  D.setFunctionDefinitionKind(FDK_Definition);
+  Decl *DP = HandleDeclarator(ParentScope, D,
+                              move(TemplateParameterLists));
+  if (FunctionTemplateDecl *FunctionTemplate
+        = dyn_cast_or_null<FunctionTemplateDecl>(DP))
+    return ActOnStartOfFunctionDef(FnBodyScope,
+                                   FunctionTemplate->getTemplatedDecl());
+  if (FunctionDecl *Function = dyn_cast_or_null<FunctionDecl>(DP))
+    return ActOnStartOfFunctionDef(FnBodyScope, Function);
+  return 0;
+}
+
+/// \brief Strips various properties off an implicit instantiation
+/// that has just been explicitly specialized.
+static void StripImplicitInstantiation(NamedDecl *D) {
+  // FIXME: "make check" is clean if the call to dropAttrs() is commented out.
+  D->dropAttrs();
+
+  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    FD->setInlineSpecified(false);
+  }
+}
+
+/// \brief Compute the diagnostic location for an explicit instantiation
+//  declaration or definition.
+static SourceLocation DiagLocForExplicitInstantiation(
+    NamedDecl* D, SourceLocation PointOfInstantiation) {
+  // Explicit instantiations following a specialization have no effect and
+  // hence no PointOfInstantiation. In that case, walk decl backwards
+  // until a valid name loc is found.
+  SourceLocation PrevDiagLoc = PointOfInstantiation;
+  for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
+       Prev = Prev->getPreviousDecl()) {
+    PrevDiagLoc = Prev->getLocation();
+  }
+  assert(PrevDiagLoc.isValid() &&
+         "Explicit instantiation without point of instantiation?");
+  return PrevDiagLoc;
+}
+
+/// \brief Diagnose cases where we have an explicit template specialization
+/// before/after an explicit template instantiation, producing diagnostics
+/// for those cases where they are required and determining whether the
+/// new specialization/instantiation will have any effect.
+///
+/// \param NewLoc the location of the new explicit specialization or
+/// instantiation.
+///
+/// \param NewTSK the kind of the new explicit specialization or instantiation.
+///
+/// \param PrevDecl the previous declaration of the entity.
+///
+/// \param PrevTSK the kind of the old explicit specialization or instantiatin.
+///
+/// \param PrevPointOfInstantiation if valid, indicates where the previus
+/// declaration was instantiated (either implicitly or explicitly).
+///
+/// \param HasNoEffect will be set to true to indicate that the new
+/// specialization or instantiation has no effect and should be ignored.
+///
+/// \returns true if there was an error that should prevent the introduction of
+/// the new declaration into the AST, false otherwise.
+bool
+Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
+                                             TemplateSpecializationKind NewTSK,
+                                             NamedDecl *PrevDecl,
+                                             TemplateSpecializationKind PrevTSK,
+                                        SourceLocation PrevPointOfInstantiation,
+                                             bool &HasNoEffect) {
+  HasNoEffect = false;
+
+  switch (NewTSK) {
+  case TSK_Undeclared:
+  case TSK_ImplicitInstantiation:
+    llvm_unreachable("Don't check implicit instantiations here");
+
+  case TSK_ExplicitSpecialization:
+    switch (PrevTSK) {
+    case TSK_Undeclared:
+    case TSK_ExplicitSpecialization:
+      // Okay, we're just specializing something that is either already
+      // explicitly specialized or has merely been mentioned without any
+      // instantiation.
+      return false;
+
+    case TSK_ImplicitInstantiation:
+      if (PrevPointOfInstantiation.isInvalid()) {
+        // The declaration itself has not actually been instantiated, so it is
+        // still okay to specialize it.
+        StripImplicitInstantiation(PrevDecl);
+        return false;
+      }
+      // Fall through
+
+    case TSK_ExplicitInstantiationDeclaration:
+    case TSK_ExplicitInstantiationDefinition:
+      assert((PrevTSK == TSK_ImplicitInstantiation ||
+              PrevPointOfInstantiation.isValid()) &&
+             "Explicit instantiation without point of instantiation?");
+
+      // C++ [temp.expl.spec]p6:
+      //   If a template, a member template or the member of a class template
+      //   is explicitly specialized then that specialization shall be declared
+      //   before the first use of that specialization that would cause an
+      //   implicit instantiation to take place, in every translation unit in
+      //   which such a use occurs; no diagnostic is required.
+      for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
+        // Is there any previous explicit specialization declaration?
+        if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
+          return false;
+      }
+
+      Diag(NewLoc, diag::err_specialization_after_instantiation)
+        << PrevDecl;
+      Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
+        << (PrevTSK != TSK_ImplicitInstantiation);
+
+      return true;
+    }
+
+  case TSK_ExplicitInstantiationDeclaration:
+    switch (PrevTSK) {
+    case TSK_ExplicitInstantiationDeclaration:
+      // This explicit instantiation declaration is redundant (that's okay).
+      HasNoEffect = true;
+      return false;
+
+    case TSK_Undeclared:
+    case TSK_ImplicitInstantiation:
+      // We're explicitly instantiating something that may have already been
+      // implicitly instantiated; that's fine.
+      return false;
+
+    case TSK_ExplicitSpecialization:
+      // C++0x [temp.explicit]p4:
+      //   For a given set of template parameters, if an explicit instantiation
+      //   of a template appears after a declaration of an explicit
+      //   specialization for that template, the explicit instantiation has no
+      //   effect.
+      HasNoEffect = true;
+      return false;
+
+    case TSK_ExplicitInstantiationDefinition:
+      // C++0x [temp.explicit]p10:
+      //   If an entity is the subject of both an explicit instantiation
+      //   declaration and an explicit instantiation definition in the same
+      //   translation unit, the definition shall follow the declaration.
+      Diag(NewLoc,
+           diag::err_explicit_instantiation_declaration_after_definition);
+
+      // Explicit instantiations following a specialization have no effect and
+      // hence no PrevPointOfInstantiation. In that case, walk decl backwards
+      // until a valid name loc is found.
+      Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
+           diag::note_explicit_instantiation_definition_here);
+      HasNoEffect = true;
+      return false;
+    }
+
+  case TSK_ExplicitInstantiationDefinition:
+    switch (PrevTSK) {
+    case TSK_Undeclared:
+    case TSK_ImplicitInstantiation:
+      // We're explicitly instantiating something that may have already been
+      // implicitly instantiated; that's fine.
+      return false;
+
+    case TSK_ExplicitSpecialization:
+      // C++ DR 259, C++0x [temp.explicit]p4:
+      //   For a given set of template parameters, if an explicit
+      //   instantiation of a template appears after a declaration of
+      //   an explicit specialization for that template, the explicit
+      //   instantiation has no effect.
+      //
+      // In C++98/03 mode, we only give an extension warning here, because it
+      // is not harmful to try to explicitly instantiate something that
+      // has been explicitly specialized.
+      Diag(NewLoc, getLangOpts().CPlusPlus0x ?
+           diag::warn_cxx98_compat_explicit_instantiation_after_specialization :
+           diag::ext_explicit_instantiation_after_specialization)
+        << PrevDecl;
+      Diag(PrevDecl->getLocation(),
+           diag::note_previous_template_specialization);
+      HasNoEffect = true;
+      return false;
+
+    case TSK_ExplicitInstantiationDeclaration:
+      // We're explicity instantiating a definition for something for which we
+      // were previously asked to suppress instantiations. That's fine.
+
+      // C++0x [temp.explicit]p4:
+      //   For a given set of template parameters, if an explicit instantiation
+      //   of a template appears after a declaration of an explicit
+      //   specialization for that template, the explicit instantiation has no
+      //   effect.
+      for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
+        // Is there any previous explicit specialization declaration?
+        if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
+          HasNoEffect = true;
+          break;
+        }
+      }
+
+      return false;
+
+    case TSK_ExplicitInstantiationDefinition:
+      // C++0x [temp.spec]p5:
+      //   For a given template and a given set of template-arguments,
+      //     - an explicit instantiation definition shall appear at most once
+      //       in a program,
+      Diag(NewLoc, diag::err_explicit_instantiation_duplicate)
+        << PrevDecl;
+      Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
+           diag::note_previous_explicit_instantiation);
+      HasNoEffect = true;
+      return false;
+    }
+  }
+
+  llvm_unreachable("Missing specialization/instantiation case?");
+}
+
+/// \brief Perform semantic analysis for the given dependent function
+/// template specialization.  The only possible way to get a dependent
+/// function template specialization is with a friend declaration,
+/// like so:
+///
+///   template <class T> void foo(T);
+///   template <class T> class A {
+///     friend void foo<>(T);
+///   };
+///
+/// There really isn't any useful analysis we can do here, so we
+/// just store the information.
+bool
+Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
+                   const TemplateArgumentListInfo &ExplicitTemplateArgs,
+                                                   LookupResult &Previous) {
+  // Remove anything from Previous that isn't a function template in
+  // the correct context.
+  DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
+  LookupResult::Filter F = Previous.makeFilter();
+  while (F.hasNext()) {
+    NamedDecl *D = F.next()->getUnderlyingDecl();
+    if (!isa<FunctionTemplateDecl>(D) ||
+        !FDLookupContext->InEnclosingNamespaceSetOf(
+                              D->getDeclContext()->getRedeclContext()))
+      F.erase();
+  }
+  F.done();
+
+  // Should this be diagnosed here?
+  if (Previous.empty()) return true;
+
+  FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
+                                         ExplicitTemplateArgs);
+  return false;
+}
+
+/// \brief Perform semantic analysis for the given function template
+/// specialization.
+///
+/// This routine performs all of the semantic analysis required for an
+/// explicit function template specialization. On successful completion,
+/// the function declaration \p FD will become a function template
+/// specialization.
+///
+/// \param FD the function declaration, which will be updated to become a
+/// function template specialization.
+///
+/// \param ExplicitTemplateArgs the explicitly-provided template arguments,
+/// if any. Note that this may be valid info even when 0 arguments are
+/// explicitly provided as in, e.g., \c void sort<>(char*, char*);
+/// as it anyway contains info on the angle brackets locations.
+///
+/// \param Previous the set of declarations that may be specialized by
+/// this function specialization.
+bool
+Sema::CheckFunctionTemplateSpecialization(FunctionDecl *FD,
+                                 TemplateArgumentListInfo *ExplicitTemplateArgs,
+                                          LookupResult &Previous) {
+  // The set of function template specializations that could match this
+  // explicit function template specialization.
+  UnresolvedSet<8> Candidates;
+
+  DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
+  for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
+         I != E; ++I) {
+    NamedDecl *Ovl = (*I)->getUnderlyingDecl();
+    if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
+      // Only consider templates found within the same semantic lookup scope as
+      // FD.
+      if (!FDLookupContext->InEnclosingNamespaceSetOf(
+                                Ovl->getDeclContext()->getRedeclContext()))
+        continue;
+
+      // C++ [temp.expl.spec]p11:
+      //   A trailing template-argument can be left unspecified in the
+      //   template-id naming an explicit function template specialization
+      //   provided it can be deduced from the function argument type.
+      // Perform template argument deduction to determine whether we may be
+      // specializing this template.
+      // FIXME: It is somewhat wasteful to build
+      TemplateDeductionInfo Info(Context, FD->getLocation());
+      FunctionDecl *Specialization = 0;
+      if (TemplateDeductionResult TDK
+            = DeduceTemplateArguments(FunTmpl, ExplicitTemplateArgs,
+                                      FD->getType(),
+                                      Specialization,
+                                      Info)) {
+        // FIXME: Template argument deduction failed; record why it failed, so
+        // that we can provide nifty diagnostics.
+        (void)TDK;
+        continue;
+      }
+
+      // Record this candidate.
+      Candidates.addDecl(Specialization, I.getAccess());
+    }
+  }
+
+  // Find the most specialized function template.
+  UnresolvedSetIterator Result
+    = getMostSpecialized(Candidates.begin(), Candidates.end(),
+                         TPOC_Other, 0, FD->getLocation(),
+                  PDiag(diag::err_function_template_spec_no_match)
+                    << FD->getDeclName(),
+                  PDiag(diag::err_function_template_spec_ambiguous)
+                    << FD->getDeclName() << (ExplicitTemplateArgs != 0),
+                  PDiag(diag::note_function_template_spec_matched));
+  if (Result == Candidates.end())
+    return true;
+
+  // Ignore access information;  it doesn't figure into redeclaration checking.
+  FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
+
+  FunctionTemplateSpecializationInfo *SpecInfo
+    = Specialization->getTemplateSpecializationInfo();
+  assert(SpecInfo && "Function template specialization info missing?");
+
+  // Note: do not overwrite location info if previous template
+  // specialization kind was explicit.
+  TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
+  if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
+    Specialization->setLocation(FD->getLocation());
+    // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
+    // function can differ from the template declaration with respect to
+    // the constexpr specifier.
+    Specialization->setConstexpr(FD->isConstexpr());
+  }
+
+  // FIXME: Check if the prior specialization has a point of instantiation.
+  // If so, we have run afoul of .
+
+  // If this is a friend declaration, then we're not really declaring
+  // an explicit specialization.
+  bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
+
+  // Check the scope of this explicit specialization.
+  if (!isFriend &&
+      CheckTemplateSpecializationScope(*this,
+                                       Specialization->getPrimaryTemplate(),
+                                       Specialization, FD->getLocation(),
+                                       false))
+    return true;
+
+  // C++ [temp.expl.spec]p6:
+  //   If a template, a member template or the member of a class template is
+  //   explicitly specialized then that specialization shall be declared
+  //   before the first use of that specialization that would cause an implicit
+  //   instantiation to take place, in every translation unit in which such a
+  //   use occurs; no diagnostic is required.
+  bool HasNoEffect = false;
+  if (!isFriend &&
+      CheckSpecializationInstantiationRedecl(FD->getLocation(),
+                                             TSK_ExplicitSpecialization,
+                                             Specialization,
+                                   SpecInfo->getTemplateSpecializationKind(),
+                                         SpecInfo->getPointOfInstantiation(),
+                                             HasNoEffect))
+    return true;
+  
+  // Mark the prior declaration as an explicit specialization, so that later
+  // clients know that this is an explicit specialization.
+  if (!isFriend) {
+    SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
+    MarkUnusedFileScopedDecl(Specialization);
+  }
+
+  // Turn the given function declaration into a function template
+  // specialization, with the template arguments from the previous
+  // specialization.
+  // Take copies of (semantic and syntactic) template argument lists.
+  const TemplateArgumentList* TemplArgs = new (Context)
+    TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
+  FD->setFunctionTemplateSpecialization(Specialization->getPrimaryTemplate(),
+                                        TemplArgs, /*InsertPos=*/0,
+                                    SpecInfo->getTemplateSpecializationKind(),
+                                        ExplicitTemplateArgs);
+  FD->setStorageClass(Specialization->getStorageClass());
+  
+  // The "previous declaration" for this function template specialization is
+  // the prior function template specialization.
+  Previous.clear();
+  Previous.addDecl(Specialization);
+  return false;
+}
+
+/// \brief Perform semantic analysis for the given non-template member
+/// specialization.
+///
+/// This routine performs all of the semantic analysis required for an
+/// explicit member function specialization. On successful completion,
+/// the function declaration \p FD will become a member function
+/// specialization.
+///
+/// \param Member the member declaration, which will be updated to become a
+/// specialization.
+///
+/// \param Previous the set of declarations, one of which may be specialized
+/// by this function specialization;  the set will be modified to contain the
+/// redeclared member.
+bool
+Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
+  assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
+
+  // Try to find the member we are instantiating.
+  NamedDecl *Instantiation = 0;
+  NamedDecl *InstantiatedFrom = 0;
+  MemberSpecializationInfo *MSInfo = 0;
+
+  if (Previous.empty()) {
+    // Nowhere to look anyway.
+  } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
+    for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
+           I != E; ++I) {
+      NamedDecl *D = (*I)->getUnderlyingDecl();
+      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
+        if (Context.hasSameType(Function->getType(), Method->getType())) {
+          Instantiation = Method;
+          InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
+          MSInfo = Method->getMemberSpecializationInfo();
+          break;
+        }
+      }
+    }
+  } else if (isa<VarDecl>(Member)) {
+    VarDecl *PrevVar;
+    if (Previous.isSingleResult() &&
+        (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
+      if (PrevVar->isStaticDataMember()) {
+        Instantiation = PrevVar;
+        InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
+        MSInfo = PrevVar->getMemberSpecializationInfo();
+      }
+  } else if (isa<RecordDecl>(Member)) {
+    CXXRecordDecl *PrevRecord;
+    if (Previous.isSingleResult() &&
+        (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
+      Instantiation = PrevRecord;
+      InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
+      MSInfo = PrevRecord->getMemberSpecializationInfo();
+    }
+  } else if (isa<EnumDecl>(Member)) {
+    EnumDecl *PrevEnum;
+    if (Previous.isSingleResult() &&
+        (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
+      Instantiation = PrevEnum;
+      InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
+      MSInfo = PrevEnum->getMemberSpecializationInfo();
+    }
+  }
+
+  if (!Instantiation) {
+    // There is no previous declaration that matches. Since member
+    // specializations are always out-of-line, the caller will complain about
+    // this mismatch later.
+    return false;
+  }
+
+  // If this is a friend, just bail out here before we start turning
+  // things into explicit specializations.
+  if (Member->getFriendObjectKind() != Decl::FOK_None) {
+    // Preserve instantiation information.
+    if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
+      cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
+                                      cast<CXXMethodDecl>(InstantiatedFrom),
+        cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
+    } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
+      cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
+                                      cast<CXXRecordDecl>(InstantiatedFrom),
+        cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
+    }
+
+    Previous.clear();
+    Previous.addDecl(Instantiation);
+    return false;
+  }
+
+  // Make sure that this is a specialization of a member.
+  if (!InstantiatedFrom) {
+    Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
+      << Member;
+    Diag(Instantiation->getLocation(), diag::note_specialized_decl);
+    return true;
+  }
+
+  // C++ [temp.expl.spec]p6:
+  //   If a template, a member template or the member of a class template is
+  //   explicitly specialized then that specialization shall be declared
+  //   before the first use of that specialization that would cause an implicit
+  //   instantiation to take place, in every translation unit in which such a
+  //   use occurs; no diagnostic is required.
+  assert(MSInfo && "Member specialization info missing?");
+
+  bool HasNoEffect = false;
+  if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
+                                             TSK_ExplicitSpecialization,
+                                             Instantiation,
+                                     MSInfo->getTemplateSpecializationKind(),
+                                           MSInfo->getPointOfInstantiation(),
+                                             HasNoEffect))
+    return true;
+
+  // Check the scope of this explicit specialization.
+  if (CheckTemplateSpecializationScope(*this,
+                                       InstantiatedFrom,
+                                       Instantiation, Member->getLocation(),
+                                       false))
+    return true;
+
+  // Note that this is an explicit instantiation of a member.
+  // the original declaration to note that it is an explicit specialization
+  // (if it was previously an implicit instantiation). This latter step
+  // makes bookkeeping easier.
+  if (isa<FunctionDecl>(Member)) {
+    FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
+    if (InstantiationFunction->getTemplateSpecializationKind() ==
+          TSK_ImplicitInstantiation) {
+      InstantiationFunction->setTemplateSpecializationKind(
+                                                  TSK_ExplicitSpecialization);
+      InstantiationFunction->setLocation(Member->getLocation());
+    }
+
+    cast<FunctionDecl>(Member)->setInstantiationOfMemberFunction(
+                                        cast<CXXMethodDecl>(InstantiatedFrom),
+                                                  TSK_ExplicitSpecialization);
+    MarkUnusedFileScopedDecl(InstantiationFunction);
+  } else if (isa<VarDecl>(Member)) {
+    VarDecl *InstantiationVar = cast<VarDecl>(Instantiation);
+    if (InstantiationVar->getTemplateSpecializationKind() ==
+          TSK_ImplicitInstantiation) {
+      InstantiationVar->setTemplateSpecializationKind(
+                                                  TSK_ExplicitSpecialization);
+      InstantiationVar->setLocation(Member->getLocation());
+    }
+
+    Context.setInstantiatedFromStaticDataMember(cast<VarDecl>(Member),
+                                                cast<VarDecl>(InstantiatedFrom),
+                                                TSK_ExplicitSpecialization);
+    MarkUnusedFileScopedDecl(InstantiationVar);
+  } else if (isa<CXXRecordDecl>(Member)) {
+    CXXRecordDecl *InstantiationClass = cast<CXXRecordDecl>(Instantiation);
+    if (InstantiationClass->getTemplateSpecializationKind() ==
+          TSK_ImplicitInstantiation) {
+      InstantiationClass->setTemplateSpecializationKind(
+                                                   TSK_ExplicitSpecialization);
+      InstantiationClass->setLocation(Member->getLocation());
+    }
+
+    cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
+                                        cast<CXXRecordDecl>(InstantiatedFrom),
+                                                   TSK_ExplicitSpecialization);
+  } else {
+    assert(isa<EnumDecl>(Member) && "Only member enums remain");
+    EnumDecl *InstantiationEnum = cast<EnumDecl>(Instantiation);
+    if (InstantiationEnum->getTemplateSpecializationKind() ==
+          TSK_ImplicitInstantiation) {
+      InstantiationEnum->setTemplateSpecializationKind(
+                                                   TSK_ExplicitSpecialization);
+      InstantiationEnum->setLocation(Member->getLocation());
+    }
+
+    cast<EnumDecl>(Member)->setInstantiationOfMemberEnum(
+        cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
+  }
+
+  // Save the caller the trouble of having to figure out which declaration
+  // this specialization matches.
+  Previous.clear();
+  Previous.addDecl(Instantiation);
+  return false;
+}
+
+/// \brief Check the scope of an explicit instantiation.
+///
+/// \returns true if a serious error occurs, false otherwise.
+static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
+                                            SourceLocation InstLoc,
+                                            bool WasQualifiedName) {
+  DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
+  DeclContext *CurContext = S.CurContext->getRedeclContext();
+
+  if (CurContext->isRecord()) {
+    S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
+      << D;
+    return true;
+  }
+
+  // C++11 [temp.explicit]p3:
+  //   An explicit instantiation shall appear in an enclosing namespace of its
+  //   template. If the name declared in the explicit instantiation is an
+  //   unqualified name, the explicit instantiation shall appear in the
+  //   namespace where its template is declared or, if that namespace is inline
+  //   (7.3.1), any namespace from its enclosing namespace set.
+  //
+  // This is DR275, which we do not retroactively apply to C++98/03.
+  if (WasQualifiedName) {
+    if (CurContext->Encloses(OrigContext))
+      return false;
+  } else {
+    if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
+      return false;
+  }
+
+  if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
+    if (WasQualifiedName)
+      S.Diag(InstLoc,
+             S.getLangOpts().CPlusPlus0x?
+               diag::err_explicit_instantiation_out_of_scope :
+               diag::warn_explicit_instantiation_out_of_scope_0x)
+        << D << NS;
+    else
+      S.Diag(InstLoc,
+             S.getLangOpts().CPlusPlus0x?
+               diag::err_explicit_instantiation_unqualified_wrong_namespace :
+               diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
+        << D << NS;
+  } else
+    S.Diag(InstLoc,
+           S.getLangOpts().CPlusPlus0x?
+             diag::err_explicit_instantiation_must_be_global :
+             diag::warn_explicit_instantiation_must_be_global_0x)
+      << D;
+  S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
+  return false;
+}
+
+/// \brief Determine whether the given scope specifier has a template-id in it.
+static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
+  if (!SS.isSet())
+    return false;
+
+  // C++11 [temp.explicit]p3:
+  //   If the explicit instantiation is for a member function, a member class
+  //   or a static data member of a class template specialization, the name of
+  //   the class template specialization in the qualified-id for the member
+  //   name shall be a simple-template-id.
+  //
+  // C++98 has the same restriction, just worded differently.
+  for (NestedNameSpecifier *NNS = (NestedNameSpecifier *)SS.getScopeRep();
+       NNS; NNS = NNS->getPrefix())
+    if (const Type *T = NNS->getAsType())
+      if (isa<TemplateSpecializationType>(T))
+        return true;
+
+  return false;
+}
+
+// Explicit instantiation of a class template specialization
+DeclResult
+Sema::ActOnExplicitInstantiation(Scope *S,
+                                 SourceLocation ExternLoc,
+                                 SourceLocation TemplateLoc,
+                                 unsigned TagSpec,
+                                 SourceLocation KWLoc,
+                                 const CXXScopeSpec &SS,
+                                 TemplateTy TemplateD,
+                                 SourceLocation TemplateNameLoc,
+                                 SourceLocation LAngleLoc,
+                                 ASTTemplateArgsPtr TemplateArgsIn,
+                                 SourceLocation RAngleLoc,
+                                 AttributeList *Attr) {
+  // Find the class template we're specializing
+  TemplateName Name = TemplateD.getAsVal<TemplateName>();
+  ClassTemplateDecl *ClassTemplate
+    = cast<ClassTemplateDecl>(Name.getAsTemplateDecl());
+
+  // Check that the specialization uses the same tag kind as the
+  // original template.
+  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
+  assert(Kind != TTK_Enum &&
+         "Invalid enum tag in class template explicit instantiation!");
+  if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
+                                    Kind, /*isDefinition*/false, KWLoc,
+                                    *ClassTemplate->getIdentifier())) {
+    Diag(KWLoc, diag::err_use_with_wrong_tag)
+      << ClassTemplate
+      << FixItHint::CreateReplacement(KWLoc,
+                            ClassTemplate->getTemplatedDecl()->getKindName());
+    Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
+         diag::note_previous_use);
+    Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
+  }
+
+  // C++0x [temp.explicit]p2:
+  //   There are two forms of explicit instantiation: an explicit instantiation
+  //   definition and an explicit instantiation declaration. An explicit
+  //   instantiation declaration begins with the extern keyword. [...]
+  TemplateSpecializationKind TSK
+    = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
+                           : TSK_ExplicitInstantiationDeclaration;
+
+  // Translate the parser's template argument list in our AST format.
+  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
+  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
+
+  // Check that the template argument list is well-formed for this
+  // template.
+  SmallVector<TemplateArgument, 4> Converted;
+  if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
+                                TemplateArgs, false, Converted))
+    return true;
+
+  // Find the class template specialization declaration that
+  // corresponds to these arguments.
+  void *InsertPos = 0;
+  ClassTemplateSpecializationDecl *PrevDecl
+    = ClassTemplate->findSpecialization(Converted.data(),
+                                        Converted.size(), InsertPos);
+
+  TemplateSpecializationKind PrevDecl_TSK
+    = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
+
+  // C++0x [temp.explicit]p2:
+  //   [...] An explicit instantiation shall appear in an enclosing
+  //   namespace of its template. [...]
+  //
+  // This is C++ DR 275.
+  if (CheckExplicitInstantiationScope(*this, ClassTemplate, TemplateNameLoc,
+                                      SS.isSet()))
+    return true;
+
+  ClassTemplateSpecializationDecl *Specialization = 0;
+
+  bool HasNoEffect = false;
+  if (PrevDecl) {
+    if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
+                                               PrevDecl, PrevDecl_TSK,
+                                            PrevDecl->getPointOfInstantiation(),
+                                               HasNoEffect))
+      return PrevDecl;
+
+    // Even though HasNoEffect == true means that this explicit instantiation
+    // has no effect on semantics, we go on to put its syntax in the AST.
+
+    if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
+        PrevDecl_TSK == TSK_Undeclared) {
+      // Since the only prior class template specialization with these
+      // arguments was referenced but not declared, reuse that
+      // declaration node as our own, updating the source location
+      // for the template name to reflect our new declaration.
+      // (Other source locations will be updated later.)
+      Specialization = PrevDecl;
+      Specialization->setLocation(TemplateNameLoc);
+      PrevDecl = 0;
+    }
+  }
+
+  if (!Specialization) {
+    // Create a new class template specialization declaration node for
+    // this explicit specialization.
+    Specialization
+      = ClassTemplateSpecializationDecl::Create(Context, Kind,
+                                             ClassTemplate->getDeclContext(),
+                                                KWLoc, TemplateNameLoc,
+                                                ClassTemplate,
+                                                Converted.data(),
+                                                Converted.size(),
+                                                PrevDecl);
+    SetNestedNameSpecifier(Specialization, SS);
+
+    if (!HasNoEffect && !PrevDecl) {
+      // Insert the new specialization.
+      ClassTemplate->AddSpecialization(Specialization, InsertPos);
+    }
+  }
+
+  // Build the fully-sugared type for this explicit instantiation as
+  // the user wrote in the explicit instantiation itself. This means
+  // that we'll pretty-print the type retrieved from the
+  // specialization's declaration the way that the user actually wrote
+  // the explicit instantiation, rather than formatting the name based
+  // on the "canonical" representation used to store the template
+  // arguments in the specialization.
+  TypeSourceInfo *WrittenTy
+    = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
+                                                TemplateArgs,
+                                  Context.getTypeDeclType(Specialization));
+  Specialization->setTypeAsWritten(WrittenTy);
+  TemplateArgsIn.release();
+
+  // Set source locations for keywords.
+  Specialization->setExternLoc(ExternLoc);
+  Specialization->setTemplateKeywordLoc(TemplateLoc);
+
+  if (Attr)
+    ProcessDeclAttributeList(S, Specialization, Attr);
+
+  // Add the explicit instantiation into its lexical context. However,
+  // since explicit instantiations are never found by name lookup, we
+  // just put it into the declaration context directly.
+  Specialization->setLexicalDeclContext(CurContext);
+  CurContext->addDecl(Specialization);
+
+  // Syntax is now OK, so return if it has no other effect on semantics.
+  if (HasNoEffect) {
+    // Set the template specialization kind.
+    Specialization->setTemplateSpecializationKind(TSK);
+    return Specialization;
+  }
+
+  // C++ [temp.explicit]p3:
+  //   A definition of a class template or class member template
+  //   shall be in scope at the point of the explicit instantiation of
+  //   the class template or class member template.
+  //
+  // This check comes when we actually try to perform the
+  // instantiation.
+  ClassTemplateSpecializationDecl *Def
+    = cast_or_null<ClassTemplateSpecializationDecl>(
+                                              Specialization->getDefinition());
+  if (!Def)
+    InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
+  else if (TSK == TSK_ExplicitInstantiationDefinition) {
+    MarkVTableUsed(TemplateNameLoc, Specialization, true);
+    Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
+  }
+
+  // Instantiate the members of this class template specialization.
+  Def = cast_or_null<ClassTemplateSpecializationDecl>(
+                                       Specialization->getDefinition());
+  if (Def) {
+    TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
+
+    // Fix a TSK_ExplicitInstantiationDeclaration followed by a
+    // TSK_ExplicitInstantiationDefinition
+    if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
+        TSK == TSK_ExplicitInstantiationDefinition)
+      Def->setTemplateSpecializationKind(TSK);
+
+    InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
+  }
+
+  // Set the template specialization kind.
+  Specialization->setTemplateSpecializationKind(TSK);
+  return Specialization;
+}
+
+// Explicit instantiation of a member class of a class template.
+DeclResult
+Sema::ActOnExplicitInstantiation(Scope *S,
+                                 SourceLocation ExternLoc,
+                                 SourceLocation TemplateLoc,
+                                 unsigned TagSpec,
+                                 SourceLocation KWLoc,
+                                 CXXScopeSpec &SS,
+                                 IdentifierInfo *Name,
+                                 SourceLocation NameLoc,
+                                 AttributeList *Attr) {
+
+  bool Owned = false;
+  bool IsDependent = false;
+  Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
+                        KWLoc, SS, Name, NameLoc, Attr, AS_none,
+                        /*ModulePrivateLoc=*/SourceLocation(),
+                        MultiTemplateParamsArg(*this, 0, 0),
+                        Owned, IsDependent, SourceLocation(), false,
+                        TypeResult());
+  assert(!IsDependent && "explicit instantiation of dependent name not yet handled");
+
+  if (!TagD)
+    return true;
+
+  TagDecl *Tag = cast<TagDecl>(TagD);
+  assert(!Tag->isEnum() && "shouldn't see enumerations here");
+
+  if (Tag->isInvalidDecl())
+    return true;
+
+  CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
+  CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
+  if (!Pattern) {
+    Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
+      << Context.getTypeDeclType(Record);
+    Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
+    return true;
+  }
+
+  // C++0x [temp.explicit]p2:
+  //   If the explicit instantiation is for a class or member class, the
+  //   elaborated-type-specifier in the declaration shall include a
+  //   simple-template-id.
+  //
+  // C++98 has the same restriction, just worded differently.
+  if (!ScopeSpecifierHasTemplateId(SS))
+    Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
+      << Record << SS.getRange();
+
+  // C++0x [temp.explicit]p2:
+  //   There are two forms of explicit instantiation: an explicit instantiation
+  //   definition and an explicit instantiation declaration. An explicit
+  //   instantiation declaration begins with the extern keyword. [...]
+  TemplateSpecializationKind TSK
+    = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
+                           : TSK_ExplicitInstantiationDeclaration;
+
+  // C++0x [temp.explicit]p2:
+  //   [...] An explicit instantiation shall appear in an enclosing
+  //   namespace of its template. [...]
+  //
+  // This is C++ DR 275.
+  CheckExplicitInstantiationScope(*this, Record, NameLoc, true);
+
+  // Verify that it is okay to explicitly instantiate here.
+  CXXRecordDecl *PrevDecl
+    = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
+  if (!PrevDecl && Record->getDefinition())
+    PrevDecl = Record;
+  if (PrevDecl) {
+    MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
+    bool HasNoEffect = false;
+    assert(MSInfo && "No member specialization information?");
+    if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
+                                               PrevDecl,
+                                        MSInfo->getTemplateSpecializationKind(),
+                                             MSInfo->getPointOfInstantiation(),
+                                               HasNoEffect))
+      return true;
+    if (HasNoEffect)
+      return TagD;
+  }
+
+  CXXRecordDecl *RecordDef
+    = cast_or_null<CXXRecordDecl>(Record->getDefinition());
+  if (!RecordDef) {
+    // C++ [temp.explicit]p3:
+    //   A definition of a member class of a class template shall be in scope
+    //   at the point of an explicit instantiation of the member class.
+    CXXRecordDecl *Def
+      = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
+    if (!Def) {
+      Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
+        << 0 << Record->getDeclName() << Record->getDeclContext();
+      Diag(Pattern->getLocation(), diag::note_forward_declaration)
+        << Pattern;
+      return true;
+    } else {
+      if (InstantiateClass(NameLoc, Record, Def,
+                           getTemplateInstantiationArgs(Record),
+                           TSK))
+        return true;
+
+      RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
+      if (!RecordDef)
+        return true;
+    }
+  }
+
+  // Instantiate all of the members of the class.
+  InstantiateClassMembers(NameLoc, RecordDef,
+                          getTemplateInstantiationArgs(Record), TSK);
+
+  if (TSK == TSK_ExplicitInstantiationDefinition)
+    MarkVTableUsed(NameLoc, RecordDef, true);
+
+  // FIXME: We don't have any representation for explicit instantiations of
+  // member classes. Such a representation is not needed for compilation, but it
+  // should be available for clients that want to see all of the declarations in
+  // the source code.
+  return TagD;
+}
+
+DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
+                                            SourceLocation ExternLoc,
+                                            SourceLocation TemplateLoc,
+                                            Declarator &D) {
+  // Explicit instantiations always require a name.
+  // TODO: check if/when DNInfo should replace Name.
+  DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
+  DeclarationName Name = NameInfo.getName();
+  if (!Name) {
+    if (!D.isInvalidType())
+      Diag(D.getDeclSpec().getLocStart(),
+           diag::err_explicit_instantiation_requires_name)
+        << D.getDeclSpec().getSourceRange()
+        << D.getSourceRange();
+
+    return true;
+  }
+
+  // The scope passed in may not be a decl scope.  Zip up the scope tree until
+  // we find one that is.
+  while ((S->getFlags() & Scope::DeclScope) == 0 ||
+         (S->getFlags() & Scope::TemplateParamScope) != 0)
+    S = S->getParent();
+
+  // Determine the type of the declaration.
+  TypeSourceInfo *T = GetTypeForDeclarator(D, S);
+  QualType R = T->getType();
+  if (R.isNull())
+    return true;
+
+  // C++ [dcl.stc]p1:
+  //   A storage-class-specifier shall not be specified in [...] an explicit 
+  //   instantiation (14.7.2) directive.
+  if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
+    Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
+      << Name;
+    return true;
+  } else if (D.getDeclSpec().getStorageClassSpec() 
+                                                != DeclSpec::SCS_unspecified) {
+    // Complain about then remove the storage class specifier.
+    Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
+      << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
+    
+    D.getMutableDeclSpec().ClearStorageClassSpecs();
+  }
+
+  // C++0x [temp.explicit]p1:
+  //   [...] An explicit instantiation of a function template shall not use the
+  //   inline or constexpr specifiers.
+  // Presumably, this also applies to member functions of class templates as
+  // well.
+  if (D.getDeclSpec().isInlineSpecified())
+    Diag(D.getDeclSpec().getInlineSpecLoc(),
+         getLangOpts().CPlusPlus0x ?
+           diag::err_explicit_instantiation_inline :
+           diag::warn_explicit_instantiation_inline_0x)
+      << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
+  if (D.getDeclSpec().isConstexprSpecified())
+    // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
+    // not already specified.
+    Diag(D.getDeclSpec().getConstexprSpecLoc(),
+         diag::err_explicit_instantiation_constexpr);
+
+  // C++0x [temp.explicit]p2:
+  //   There are two forms of explicit instantiation: an explicit instantiation
+  //   definition and an explicit instantiation declaration. An explicit
+  //   instantiation declaration begins with the extern keyword. [...]
+  TemplateSpecializationKind TSK
+    = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
+                           : TSK_ExplicitInstantiationDeclaration;
+
+  LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
+  LookupParsedName(Previous, S, &D.getCXXScopeSpec());
+
+  if (!R->isFunctionType()) {
+    // C++ [temp.explicit]p1:
+    //   A [...] static data member of a class template can be explicitly
+    //   instantiated from the member definition associated with its class
+    //   template.
+    if (Previous.isAmbiguous())
+      return true;
+
+    VarDecl *Prev = Previous.getAsSingle<VarDecl>();
+    if (!Prev || !Prev->isStaticDataMember()) {
+      // We expect to see a data data member here.
+      Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
+        << Name;
+      for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
+           P != PEnd; ++P)
+        Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
+      return true;
+    }
+
+    if (!Prev->getInstantiatedFromStaticDataMember()) {
+      // FIXME: Check for explicit specialization?
+      Diag(D.getIdentifierLoc(),
+           diag::err_explicit_instantiation_data_member_not_instantiated)
+        << Prev;
+      Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
+      // FIXME: Can we provide a note showing where this was declared?
+      return true;
+    }
+
+    // C++0x [temp.explicit]p2:
+    //   If the explicit instantiation is for a member function, a member class
+    //   or a static data member of a class template specialization, the name of
+    //   the class template specialization in the qualified-id for the member
+    //   name shall be a simple-template-id.
+    //
+    // C++98 has the same restriction, just worded differently.
+    if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
+      Diag(D.getIdentifierLoc(),
+           diag::ext_explicit_instantiation_without_qualified_id)
+        << Prev << D.getCXXScopeSpec().getRange();
+
+    // Check the scope of this explicit instantiation.
+    CheckExplicitInstantiationScope(*this, Prev, D.getIdentifierLoc(), true);
+
+    // Verify that it is okay to explicitly instantiate here.
+    MemberSpecializationInfo *MSInfo = Prev->getMemberSpecializationInfo();
+    assert(MSInfo && "Missing static data member specialization info?");
+    bool HasNoEffect = false;
+    if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
+                                        MSInfo->getTemplateSpecializationKind(),
+                                              MSInfo->getPointOfInstantiation(),
+                                               HasNoEffect))
+      return true;
+    if (HasNoEffect)
+      return (Decl*) 0;
+
+    // Instantiate static data member.
+    Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
+    if (TSK == TSK_ExplicitInstantiationDefinition)
+      InstantiateStaticDataMemberDefinition(D.getIdentifierLoc(), Prev);
+
+    // FIXME: Create an ExplicitInstantiation node?
+    return (Decl*) 0;
+  }
+
+  // If the declarator is a template-id, translate the parser's template
+  // argument list into our AST format.
+  bool HasExplicitTemplateArgs = false;
+  TemplateArgumentListInfo TemplateArgs;
+  if (D.getName().getKind() == UnqualifiedId::IK_TemplateId) {
+    TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
+    TemplateArgs.setLAngleLoc(TemplateId->LAngleLoc);
+    TemplateArgs.setRAngleLoc(TemplateId->RAngleLoc);
+    ASTTemplateArgsPtr TemplateArgsPtr(*this,
+                                       TemplateId->getTemplateArgs(),
+                                       TemplateId->NumArgs);
+    translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
+    HasExplicitTemplateArgs = true;
+    TemplateArgsPtr.release();
+  }
+
+  // C++ [temp.explicit]p1:
+  //   A [...] function [...] can be explicitly instantiated from its template.
+  //   A member function [...] of a class template can be explicitly
+  //  instantiated from the member definition associated with its class
+  //  template.
+  UnresolvedSet<8> Matches;
+  for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
+       P != PEnd; ++P) {
+    NamedDecl *Prev = *P;
+    if (!HasExplicitTemplateArgs) {
+      if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
+        if (Context.hasSameUnqualifiedType(Method->getType(), R)) {
+          Matches.clear();
+
+          Matches.addDecl(Method, P.getAccess());
+          if (Method->getTemplateSpecializationKind() == TSK_Undeclared)
+            break;
+        }
+      }
+    }
+
+    FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
+    if (!FunTmpl)
+      continue;
+
+    TemplateDeductionInfo Info(Context, D.getIdentifierLoc());
+    FunctionDecl *Specialization = 0;
+    if (TemplateDeductionResult TDK
+          = DeduceTemplateArguments(FunTmpl,
+                               (HasExplicitTemplateArgs ? &TemplateArgs : 0),
+                                    R, Specialization, Info)) {
+      // FIXME: Keep track of almost-matches?
+      (void)TDK;
+      continue;
+    }
+
+    Matches.addDecl(Specialization, P.getAccess());
+  }
+
+  // Find the most specialized function template specialization.
+  UnresolvedSetIterator Result
+    = getMostSpecialized(Matches.begin(), Matches.end(), TPOC_Other, 0,
+                         D.getIdentifierLoc(),
+                     PDiag(diag::err_explicit_instantiation_not_known) << Name,
+                     PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
+                         PDiag(diag::note_explicit_instantiation_candidate));
+
+  if (Result == Matches.end())
+    return true;
+
+  // Ignore access control bits, we don't need them for redeclaration checking.
+  FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
+
+  if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
+    Diag(D.getIdentifierLoc(),
+         diag::err_explicit_instantiation_member_function_not_instantiated)
+      << Specialization
+      << (Specialization->getTemplateSpecializationKind() ==
+          TSK_ExplicitSpecialization);
+    Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
+    return true;
+  }
+
+  FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
+  if (!PrevDecl && Specialization->isThisDeclarationADefinition())
+    PrevDecl = Specialization;
+
+  if (PrevDecl) {
+    bool HasNoEffect = false;
+    if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
+                                               PrevDecl,
+                                     PrevDecl->getTemplateSpecializationKind(),
+                                          PrevDecl->getPointOfInstantiation(),
+                                               HasNoEffect))
+      return true;
+
+    // FIXME: We may still want to build some representation of this
+    // explicit specialization.
+    if (HasNoEffect)
+      return (Decl*) 0;
+  }
+
+  Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
+  AttributeList *Attr = D.getDeclSpec().getAttributes().getList();
+  if (Attr)
+    ProcessDeclAttributeList(S, Specialization, Attr);
+
+  if (TSK == TSK_ExplicitInstantiationDefinition)
+    InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
+
+  // C++0x [temp.explicit]p2:
+  //   If the explicit instantiation is for a member function, a member class
+  //   or a static data member of a class template specialization, the name of
+  //   the class template specialization in the qualified-id for the member
+  //   name shall be a simple-template-id.
+  //
+  // C++98 has the same restriction, just worded differently.
+  FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
+  if (D.getName().getKind() != UnqualifiedId::IK_TemplateId && !FunTmpl &&
+      D.getCXXScopeSpec().isSet() &&
+      !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
+    Diag(D.getIdentifierLoc(),
+         diag::ext_explicit_instantiation_without_qualified_id)
+    << Specialization << D.getCXXScopeSpec().getRange();
+
+  CheckExplicitInstantiationScope(*this,
+                   FunTmpl? (NamedDecl *)FunTmpl
+                          : Specialization->getInstantiatedFromMemberFunction(),
+                                  D.getIdentifierLoc(),
+                                  D.getCXXScopeSpec().isSet());
+
+  // FIXME: Create some kind of ExplicitInstantiationDecl here.
+  return (Decl*) 0;
+}
+
+TypeResult
+Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
+                        const CXXScopeSpec &SS, IdentifierInfo *Name,
+                        SourceLocation TagLoc, SourceLocation NameLoc) {
+  // This has to hold, because SS is expected to be defined.
+  assert(Name && "Expected a name in a dependent tag");
+
+  NestedNameSpecifier *NNS
+    = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
+  if (!NNS)
+    return true;
+
+  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
+
+  if (TUK == TUK_Declaration || TUK == TUK_Definition) {
+    Diag(NameLoc, diag::err_dependent_tag_decl)
+      << (TUK == TUK_Definition) << Kind << SS.getRange();
+    return true;
+  }
+
+  // Create the resulting type.
+  ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
+  QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
+  
+  // Create type-source location information for this type.
+  TypeLocBuilder TLB;
+  DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
+  TL.setElaboratedKeywordLoc(TagLoc);
+  TL.setQualifierLoc(SS.getWithLocInContext(Context));
+  TL.setNameLoc(NameLoc);
+  return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
+}
+
+TypeResult
+Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
+                        const CXXScopeSpec &SS, const IdentifierInfo &II,
+                        SourceLocation IdLoc) {
+  if (SS.isInvalid())
+    return true;
+  
+  if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
+    Diag(TypenameLoc,
+         getLangOpts().CPlusPlus0x ?
+           diag::warn_cxx98_compat_typename_outside_of_template :
+           diag::ext_typename_outside_of_template)
+      << FixItHint::CreateRemoval(TypenameLoc);
+
+  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
+  QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
+                                 TypenameLoc, QualifierLoc, II, IdLoc);
+  if (T.isNull())
+    return true;
+
+  TypeSourceInfo *TSI = Context.CreateTypeSourceInfo(T);
+  if (isa<DependentNameType>(T)) {
+    DependentNameTypeLoc TL = cast<DependentNameTypeLoc>(TSI->getTypeLoc());
+    TL.setElaboratedKeywordLoc(TypenameLoc);
+    TL.setQualifierLoc(QualifierLoc);
+    TL.setNameLoc(IdLoc);
+  } else {
+    ElaboratedTypeLoc TL = cast<ElaboratedTypeLoc>(TSI->getTypeLoc());
+    TL.setElaboratedKeywordLoc(TypenameLoc);
+    TL.setQualifierLoc(QualifierLoc);
+    cast<TypeSpecTypeLoc>(TL.getNamedTypeLoc()).setNameLoc(IdLoc);
+  }
+
+  return CreateParsedType(T, TSI);
+}
+
+TypeResult
+Sema::ActOnTypenameType(Scope *S,
+                        SourceLocation TypenameLoc,
+                        const CXXScopeSpec &SS,
+                        SourceLocation TemplateKWLoc,
+                        TemplateTy TemplateIn,
+                        SourceLocation TemplateNameLoc,
+                        SourceLocation LAngleLoc,
+                        ASTTemplateArgsPtr TemplateArgsIn,
+                        SourceLocation RAngleLoc) {
+  if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
+    Diag(TypenameLoc,
+         getLangOpts().CPlusPlus0x ?
+           diag::warn_cxx98_compat_typename_outside_of_template :
+           diag::ext_typename_outside_of_template)
+      << FixItHint::CreateRemoval(TypenameLoc);
+  
+  // Translate the parser's template argument list in our AST format.
+  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
+  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
+  
+  TemplateName Template = TemplateIn.get();
+  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
+    // Construct a dependent template specialization type.
+    assert(DTN && "dependent template has non-dependent name?");
+    assert(DTN->getQualifier()
+           == static_cast<NestedNameSpecifier*>(SS.getScopeRep()));
+    QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
+                                                          DTN->getQualifier(),
+                                                          DTN->getIdentifier(),
+                                                                TemplateArgs);
+    
+    // Create source-location information for this type.
+    TypeLocBuilder Builder;
+    DependentTemplateSpecializationTypeLoc SpecTL 
+    = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
+    SpecTL.setElaboratedKeywordLoc(TypenameLoc);
+    SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
+    SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+    SpecTL.setTemplateNameLoc(TemplateNameLoc);
+    SpecTL.setLAngleLoc(LAngleLoc);
+    SpecTL.setRAngleLoc(RAngleLoc);
+    for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
+      SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
+    return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
+  }
+  
+  QualType T = CheckTemplateIdType(Template, TemplateNameLoc, TemplateArgs);
+  if (T.isNull())
+    return true;
+  
+  // Provide source-location information for the template specialization type.
+  TypeLocBuilder Builder;
+  TemplateSpecializationTypeLoc SpecTL
+    = Builder.push<TemplateSpecializationTypeLoc>(T);
+  SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
+  SpecTL.setTemplateNameLoc(TemplateNameLoc);
+  SpecTL.setLAngleLoc(LAngleLoc);
+  SpecTL.setRAngleLoc(RAngleLoc);
+  for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
+    SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
+  
+  T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
+  ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
+  TL.setElaboratedKeywordLoc(TypenameLoc);
+  TL.setQualifierLoc(SS.getWithLocInContext(Context));
+  
+  TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
+  return CreateParsedType(T, TSI);
+}
+
+
+/// \brief Build the type that describes a C++ typename specifier,
+/// e.g., "typename T::type".
+QualType
+Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword, 
+                        SourceLocation KeywordLoc,
+                        NestedNameSpecifierLoc QualifierLoc, 
+                        const IdentifierInfo &II,
+                        SourceLocation IILoc) {
+  CXXScopeSpec SS;
+  SS.Adopt(QualifierLoc);
+
+  DeclContext *Ctx = computeDeclContext(SS);
+  if (!Ctx) {
+    // If the nested-name-specifier is dependent and couldn't be
+    // resolved to a type, build a typename type.
+    assert(QualifierLoc.getNestedNameSpecifier()->isDependent());
+    return Context.getDependentNameType(Keyword, 
+                                        QualifierLoc.getNestedNameSpecifier(), 
+                                        &II);
+  }
+
+  // If the nested-name-specifier refers to the current instantiation,
+  // the "typename" keyword itself is superfluous. In C++03, the
+  // program is actually ill-formed. However, DR 382 (in C++0x CD1)
+  // allows such extraneous "typename" keywords, and we retroactively
+  // apply this DR to C++03 code with only a warning. In any case we continue.
+
+  if (RequireCompleteDeclContext(SS, Ctx))
+    return QualType();
+
+  DeclarationName Name(&II);
+  LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
+  LookupQualifiedName(Result, Ctx);
+  unsigned DiagID = 0;
+  Decl *Referenced = 0;
+  switch (Result.getResultKind()) {
+  case LookupResult::NotFound:
+    DiagID = diag::err_typename_nested_not_found;
+    break;
+
+  case LookupResult::FoundUnresolvedValue: {
+    // We found a using declaration that is a value. Most likely, the using
+    // declaration itself is meant to have the 'typename' keyword.
+    SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
+                          IILoc);
+    Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
+      << Name << Ctx << FullRange;
+    if (UnresolvedUsingValueDecl *Using
+          = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
+      SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
+      Diag(Loc, diag::note_using_value_decl_missing_typename)
+        << FixItHint::CreateInsertion(Loc, "typename ");
+    }
+  }
+  // Fall through to create a dependent typename type, from which we can recover
+  // better.
+
+  case LookupResult::NotFoundInCurrentInstantiation:
+    // Okay, it's a member of an unknown instantiation.
+    return Context.getDependentNameType(Keyword, 
+                                        QualifierLoc.getNestedNameSpecifier(), 
+                                        &II);
+
+  case LookupResult::Found:
+    if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
+      // We found a type. Build an ElaboratedType, since the
+      // typename-specifier was just sugar.
+      return Context.getElaboratedType(ETK_Typename, 
+                                       QualifierLoc.getNestedNameSpecifier(),
+                                       Context.getTypeDeclType(Type));
+    }
+
+    DiagID = diag::err_typename_nested_not_type;
+    Referenced = Result.getFoundDecl();
+    break;
+
+  case LookupResult::FoundOverloaded:
+    DiagID = diag::err_typename_nested_not_type;
+    Referenced = *Result.begin();
+    break;
+
+  case LookupResult::Ambiguous:
+    return QualType();
+  }
+
+  // If we get here, it's because name lookup did not find a
+  // type. Emit an appropriate diagnostic and return an error.
+  SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
+                        IILoc);
+  Diag(IILoc, DiagID) << FullRange << Name << Ctx;
+  if (Referenced)
+    Diag(Referenced->getLocation(), diag::note_typename_refers_here)
+      << Name;
+  return QualType();
+}
+
+namespace {
+  // See Sema::RebuildTypeInCurrentInstantiation
+  class CurrentInstantiationRebuilder
+    : public TreeTransform<CurrentInstantiationRebuilder> {
+    SourceLocation Loc;
+    DeclarationName Entity;
+
+  public:
+    typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
+
+    CurrentInstantiationRebuilder(Sema &SemaRef,
+                                  SourceLocation Loc,
+                                  DeclarationName Entity)
+    : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
+      Loc(Loc), Entity(Entity) { }
+
+    /// \brief Determine whether the given type \p T has already been
+    /// transformed.
+    ///
+    /// For the purposes of type reconstruction, a type has already been
+    /// transformed if it is NULL or if it is not dependent.
+    bool AlreadyTransformed(QualType T) {
+      return T.isNull() || !T->isDependentType();
+    }
+
+    /// \brief Returns the location of the entity whose type is being
+    /// rebuilt.
+    SourceLocation getBaseLocation() { return Loc; }
+
+    /// \brief Returns the name of the entity whose type is being rebuilt.
+    DeclarationName getBaseEntity() { return Entity; }
+
+    /// \brief Sets the "base" location and entity when that
+    /// information is known based on another transformation.
+    void setBase(SourceLocation Loc, DeclarationName Entity) {
+      this->Loc = Loc;
+      this->Entity = Entity;
+    }
+      
+    ExprResult TransformLambdaExpr(LambdaExpr *E) {
+      // Lambdas never need to be transformed.
+      return E;
+    }
+  };
+}
+
+/// \brief Rebuilds a type within the context of the current instantiation.
+///
+/// The type \p T is part of the type of an out-of-line member definition of
+/// a class template (or class template partial specialization) that was parsed
+/// and constructed before we entered the scope of the class template (or
+/// partial specialization thereof). This routine will rebuild that type now
+/// that we have entered the declarator's scope, which may produce different
+/// canonical types, e.g.,
+///
+/// \code
+/// template<typename T>
+/// struct X {
+///   typedef T* pointer;
+///   pointer data();
+/// };
+///
+/// template<typename T>
+/// typename X<T>::pointer X<T>::data() { ... }
+/// \endcode
+///
+/// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
+/// since we do not know that we can look into X<T> when we parsed the type.
+/// This function will rebuild the type, performing the lookup of "pointer"
+/// in X<T> and returning an ElaboratedType whose canonical type is the same
+/// as the canonical type of T*, allowing the return types of the out-of-line
+/// definition and the declaration to match.
+TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
+                                                        SourceLocation Loc,
+                                                        DeclarationName Name) {
+  if (!T || !T->getType()->isDependentType())
+    return T;
+
+  CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
+  return Rebuilder.TransformType(T);
+}
+
+ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
+  CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
+                                          DeclarationName());
+  return Rebuilder.TransformExpr(E);
+}
+
+bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
+  if (SS.isInvalid()) 
+    return true;
+
+  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
+  CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
+                                          DeclarationName());
+  NestedNameSpecifierLoc Rebuilt 
+    = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
+  if (!Rebuilt) 
+    return true;
+
+  SS.Adopt(Rebuilt);
+  return false;
+}
+
+/// \brief Rebuild the template parameters now that we know we're in a current
+/// instantiation.
+bool Sema::RebuildTemplateParamsInCurrentInstantiation(
+                                               TemplateParameterList *Params) {
+  for (unsigned I = 0, N = Params->size(); I != N; ++I) {
+    Decl *Param = Params->getParam(I);
+    
+    // There is nothing to rebuild in a type parameter.
+    if (isa<TemplateTypeParmDecl>(Param))
+      continue;
+    
+    // Rebuild the template parameter list of a template template parameter.
+    if (TemplateTemplateParmDecl *TTP 
+        = dyn_cast<TemplateTemplateParmDecl>(Param)) {
+      if (RebuildTemplateParamsInCurrentInstantiation(
+            TTP->getTemplateParameters()))
+        return true;
+      
+      continue;
+    }
+    
+    // Rebuild the type of a non-type template parameter.
+    NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
+    TypeSourceInfo *NewTSI 
+      = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(), 
+                                          NTTP->getLocation(), 
+                                          NTTP->getDeclName());
+    if (!NewTSI)
+      return true;
+    
+    if (NewTSI != NTTP->getTypeSourceInfo()) {
+      NTTP->setTypeSourceInfo(NewTSI);
+      NTTP->setType(NewTSI->getType());
+    }
+  }
+  
+  return false;
+}
+
+/// \brief Produces a formatted string that describes the binding of
+/// template parameters to template arguments.
+std::string
+Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
+                                      const TemplateArgumentList &Args) {
+  return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
+}
+
+std::string
+Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
+                                      const TemplateArgument *Args,
+                                      unsigned NumArgs) {
+  SmallString<128> Str;
+  llvm::raw_svector_ostream Out(Str);
+
+  if (!Params || Params->size() == 0 || NumArgs == 0)
+    return std::string();
+
+  for (unsigned I = 0, N = Params->size(); I != N; ++I) {
+    if (I >= NumArgs)
+      break;
+
+    if (I == 0)
+      Out << "[with ";
+    else
+      Out << ", ";
+
+    if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
+      Out << Id->getName();
+    } else {
+      Out << '$' << I;
+    }
+
+    Out << " = ";
+    Args[I].print(getPrintingPolicy(), Out);
+  }
+
+  Out << ']';
+  return Out.str();
+}
+
+void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, bool Flag) {
+  if (!FD)
+    return;
+  FD->setLateTemplateParsed(Flag);
+} 
+
+bool Sema::IsInsideALocalClassWithinATemplateFunction() {
+  DeclContext *DC = CurContext;
+
+  while (DC) {
+    if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
+      const FunctionDecl *FD = RD->isLocalClass();
+      return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
+    } else if (DC->isTranslationUnit() || DC->isNamespace())
+      return false;
+
+    DC = DC->getParent();
+  }
+  return false;
+}