Improve the representation of template names in the AST. This

representation handles the various ways in which one can name a
template, including unqualified references ("vector"), qualified
references ("std::vector"), and dependent template names
("MetaFun::template apply").

One immediate effect of this change is that the representation of
nested-name-specifiers in type names for class template
specializations (e.g., std::vector<int>) is more accurate. Rather than
representing std::vector<int> as

  std::(vector<int>)

we represent it as

  (std::vector)<int>

which more closely follows the C++ grammar. 

Additionally, templates are no longer represented as declarations
(DeclPtrTy) in Parse-Sema interactions. Instead, I've introduced a new
OpaquePtr type (TemplateTy) that holds the representation of a
TemplateName. This will simplify the handling of dependent
template-names, once we get there.






git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68074 91177308-0d34-0410-b5e6-96231b3b80d8

14 files changed, 268 insertions, 153 deletions

diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index f3cf6b18eb..bb17954727 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -483,6 +483,10 @@ ASTContext::getTypeInfo(const Type *T) {
     Align = Layout.getAlignment();
     break;
   }
+
+  case Type::TemplateSpecialization:
+    assert(false && "Dependent types have no size");
+    break;
   }
   
   assert(Align && (Align & (Align-1)) == 0 && "Alignment must be power of 2");
@@ -1358,30 +1362,31 @@ QualType ASTContext::getTemplateTypeParmType(unsigned Depth, unsigned Index,
 }
 
 QualType 
-ASTContext::getClassTemplateSpecializationType(TemplateDecl *Template,
-                                               const TemplateArgument *Args,
-                                               unsigned NumArgs,
-                                               QualType Canon) {
+ASTContext::getTemplateSpecializationType(TemplateName Template,
+                                          const TemplateArgument *Args,
+                                          unsigned NumArgs,
+                                          QualType Canon) {
+  // FIXME: If Template is dependent, canonicalize it!
+
   if (!Canon.isNull())
     Canon = getCanonicalType(Canon);
 
   llvm::FoldingSetNodeID ID;
-  ClassTemplateSpecializationType::Profile(ID, Template, Args, NumArgs);
+  TemplateSpecializationType::Profile(ID, Template, Args, NumArgs);
 
   void *InsertPos = 0;
-  ClassTemplateSpecializationType *Spec
-    = ClassTemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
+  TemplateSpecializationType *Spec
+    = TemplateSpecializationTypes.FindNodeOrInsertPos(ID, InsertPos);
 
   if (Spec)
     return QualType(Spec, 0);
   
-  void *Mem = Allocate((sizeof(ClassTemplateSpecializationType) + 
+  void *Mem = Allocate((sizeof(TemplateSpecializationType) + 
                         sizeof(TemplateArgument) * NumArgs),
                        8);
-  Spec = new (Mem) ClassTemplateSpecializationType(Template, Args, NumArgs, 
-                                                   Canon);
+  Spec = new (Mem) TemplateSpecializationType(Template, Args, NumArgs, Canon);
   Types.push_back(Spec);
-  ClassTemplateSpecializationTypes.InsertNode(Spec, InsertPos);
+  TemplateSpecializationTypes.InsertNode(Spec, InsertPos);
 
   return QualType(Spec, 0);  
 }
@@ -2486,6 +2491,53 @@ void ASTContext::setObjCConstantStringInterface(ObjCInterfaceDecl *Decl) {
   ObjCConstantStringType = getObjCInterfaceType(Decl);
 }
 
+/// \brief Retrieve the template name that represents a qualified
+/// template name such as \c std::vector.
+TemplateName ASTContext::getQualifiedTemplateName(NestedNameSpecifier *NNS, 
+                                                  bool TemplateKeyword,
+                                                  TemplateDecl *Template) {
+  llvm::FoldingSetNodeID ID;
+  QualifiedTemplateName::Profile(ID, NNS, TemplateKeyword, Template);
+
+  void *InsertPos = 0;
+  QualifiedTemplateName *QTN =
+    QualifiedTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
+  if (!QTN) {
+    QTN = new (*this,4) QualifiedTemplateName(NNS, TemplateKeyword, Template);
+    QualifiedTemplateNames.InsertNode(QTN, InsertPos);
+  }
+
+  return TemplateName(QTN);
+}
+
+/// \brief Retrieve the template name that represents a dependent
+/// template name such as \c MetaFun::template apply.
+TemplateName ASTContext::getDependentTemplateName(NestedNameSpecifier *NNS, 
+                                                  const IdentifierInfo *Name) {
+  assert(NNS->isDependent() && "Nested name specifier must be dependent");
+
+  llvm::FoldingSetNodeID ID;
+  DependentTemplateName::Profile(ID, NNS, Name);
+
+  void *InsertPos = 0;
+  DependentTemplateName *QTN =
+    DependentTemplateNames.FindNodeOrInsertPos(ID, InsertPos);
+
+  if (QTN)
+    return TemplateName(QTN);
+
+  NestedNameSpecifier *CanonNNS = getCanonicalNestedNameSpecifier(NNS);
+  if (CanonNNS == NNS) {
+    QTN = new (*this,4) DependentTemplateName(NNS, Name);
+  } else {
+    TemplateName Canon = getDependentTemplateName(CanonNNS, Name);
+    QTN = new (*this,4) DependentTemplateName(NNS, Name, Canon);
+  }
+
+  DependentTemplateNames.InsertNode(QTN, InsertPos);
+  return TemplateName(QTN);
+}
+
 /// getFromTargetType - Given one of the integer types provided by
 /// TargetInfo, produce the corresponding type. The unsigned @p Type
 /// is actually a value of type @c TargetInfo::IntType.
@@ -3033,6 +3085,10 @@ QualType ASTContext::mergeTypes(QualType LHS, QualType RHS) {
     ResultType.setCVRQualifiers(LHSCan.getCVRQualifiers());
     return ResultType;
 #endif
+
+  case Type::TemplateSpecialization:
+    assert(false && "Dependent types have no size");
+    break;
   }
 
   return QualType();
diff --git a/lib/AST/TemplateName.cpp b/lib/AST/TemplateName.cpp
new file mode 100644
index 0000000000..4e54fe4955
--- /dev/null
+++ b/lib/AST/TemplateName.cpp
@@ -0,0 +1,54 @@
+//===--- TemplateName.h - C++ Template Name Representation-------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the TemplateName interface and subclasses.
+//
+//===----------------------------------------------------------------------===//
+#include "clang/AST/TemplateName.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/NestedNameSpecifier.h"
+#include "llvm/Support/raw_ostream.h"
+
+using namespace clang;
+
+TemplateDecl *TemplateName::getAsTemplateDecl() const {
+  if (TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>())
+    return Template;
+  
+  if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName())
+    return QTN->getTemplateDecl();
+
+  return 0;
+}
+
+bool TemplateName::isDependent() const {
+  if (TemplateDecl *Template = getAsTemplateDecl()) {
+    // FIXME: We don't yet have a notion of dependent
+    // declarations. When we do, check that. This hack won't last
+    // long!.
+    return isa<TemplateTemplateParmDecl>(Template);
+  }
+
+  return true;
+}
+
+void TemplateName::Print(llvm::raw_ostream &OS) const {
+  if (TemplateDecl *Template = Storage.dyn_cast<TemplateDecl *>())
+    OS << Template->getIdentifier()->getName();
+  else if (QualifiedTemplateName *QTN = getAsQualifiedTemplateName()) {
+    QTN->getQualifier()->Print(OS);
+    if (QTN->hasTemplateKeyword())
+      OS << "template ";
+    OS << QTN->getTemplateDecl()->getIdentifier()->getName();
+  } else if (DependentTemplateName *DTN = getAsDependentTemplateName()) {
+    DTN->getQualifier()->Print(OS);
+    OS << "template ";
+    OS << DTN->getName()->getName();
+  }
+}
diff --git a/lib/AST/Type.cpp b/lib/AST/Type.cpp
index 0a3e8f91f0..6922dcc6c0 100644
--- a/lib/AST/Type.cpp
+++ b/lib/AST/Type.cpp
@@ -93,8 +93,8 @@ QualType Type::getDesugaredType() const {
     return TOE->getUnderlyingExpr()->getType().getDesugaredType();
   if (const TypeOfType *TOT = dyn_cast<TypeOfType>(this))
     return TOT->getUnderlyingType().getDesugaredType();
-  if (const ClassTemplateSpecializationType *Spec 
-        = dyn_cast<ClassTemplateSpecializationType>(this))
+  if (const TemplateSpecializationType *Spec 
+        = dyn_cast<TemplateSpecializationType>(this))
     return Spec->getCanonicalTypeInternal().getDesugaredType();
   if (const QualifiedNameType *QualName  = dyn_cast<QualifiedNameType>(this))
     return QualName->getNamedType().getDesugaredType();
@@ -549,11 +549,11 @@ const TemplateTypeParmType *Type::getAsTemplateTypeParmType() const {
   return dyn_cast<TemplateTypeParmType>(CanonicalType);
 }
 
-const ClassTemplateSpecializationType *
-Type::getAsClassTemplateSpecializationType() const {
+const TemplateSpecializationType *
+Type::getAsTemplateSpecializationType() const {
   // There is no sugar for class template specialization types, so
   // just return the canonical type pointer if it is the right class.
-  return dyn_cast<ClassTemplateSpecializationType>(CanonicalType);
+  return dyn_cast<TemplateSpecializationType>(CanonicalType);
 }
 
 bool Type::isIntegerType() const {
@@ -972,7 +972,7 @@ bool EnumType::classof(const TagType *TT) {
 }
 
 bool 
-ClassTemplateSpecializationType::
+TemplateSpecializationType::
 anyDependentTemplateArguments(const TemplateArgument *Args, unsigned NumArgs) {
   for (unsigned Idx = 0; Idx < NumArgs; ++Idx) {
     switch (Args[Idx].getKind()) {
@@ -997,17 +997,16 @@ anyDependentTemplateArguments(const TemplateArgument *Args, unsigned NumArgs) {
   return false;
 }
 
-ClassTemplateSpecializationType::
-ClassTemplateSpecializationType(TemplateDecl *T, const TemplateArgument *Args,
-                                unsigned NumArgs, QualType Canon)
-  : Type(ClassTemplateSpecialization, 
+TemplateSpecializationType::
+TemplateSpecializationType(TemplateName T, const TemplateArgument *Args,
+                           unsigned NumArgs, QualType Canon)
+  : Type(TemplateSpecialization, 
          Canon.isNull()? QualType(this, 0) : Canon,
-         /*FIXME: Check for dependent template */
-         anyDependentTemplateArguments(Args, NumArgs)),
+         T.isDependent() || anyDependentTemplateArguments(Args, NumArgs)),
     Template(T), NumArgs(NumArgs)
 {
   assert((!Canon.isNull() || 
-          anyDependentTemplateArguments(Args, NumArgs)) &&
+          T.isDependent() || anyDependentTemplateArguments(Args, NumArgs)) &&
          "No canonical type for non-dependent class template specialization");
 
   TemplateArgument *TemplateArgs 
@@ -1016,7 +1015,7 @@ ClassTemplateSpecializationType(TemplateDecl *T, const TemplateArgument *Args,
     new (&TemplateArgs[Arg]) TemplateArgument(Args[Arg]);
 }
 
-void ClassTemplateSpecializationType::Destroy(ASTContext& C) {
+void TemplateSpecializationType::Destroy(ASTContext& C) {
   for (unsigned Arg = 0; Arg < NumArgs; ++Arg) {
     // FIXME: Not all expressions get cloned, so we can't yet perform
     // this destruction.
@@ -1025,24 +1024,23 @@ void ClassTemplateSpecializationType::Destroy(ASTContext& C) {
   }
 }
 
-ClassTemplateSpecializationType::iterator
-ClassTemplateSpecializationType::end() const {
+TemplateSpecializationType::iterator
+TemplateSpecializationType::end() const {
   return begin() + getNumArgs();
 }
 
 const TemplateArgument &
-ClassTemplateSpecializationType::getArg(unsigned Idx) const {
+TemplateSpecializationType::getArg(unsigned Idx) const {
   assert(Idx < getNumArgs() && "Template argument out of range");
   return getArgs()[Idx];
 }
 
 void 
-ClassTemplateSpecializationType::Profile(llvm::FoldingSetNodeID &ID, 
-                                         TemplateDecl *T, 
-                                         const TemplateArgument *Args, 
-                                         unsigned NumArgs) {
-  ID.AddPointer(T);
-
+TemplateSpecializationType::Profile(llvm::FoldingSetNodeID &ID, 
+                                    TemplateName T, 
+                                    const TemplateArgument *Args, 
+                                    unsigned NumArgs) {
+  T.Profile(ID);
   for (unsigned Idx = 0; Idx < NumArgs; ++Idx)
     Args[Idx].Profile(ID);
 }
@@ -1351,7 +1349,7 @@ void TemplateTypeParmType::getAsStringInternal(std::string &InnerString) const {
     InnerString = Name->getName() + InnerString;
 }
 
-std::string ClassTemplateSpecializationType::PrintTemplateArgumentList(
+std::string TemplateSpecializationType::PrintTemplateArgumentList(
                                               const TemplateArgument *Args,
                                               unsigned NumArgs) {
   std::string SpecString;
@@ -1403,9 +1401,15 @@ std::string ClassTemplateSpecializationType::PrintTemplateArgumentList(
 }
 
 void 
-ClassTemplateSpecializationType::
+TemplateSpecializationType::
 getAsStringInternal(std::string &InnerString) const {
-  std::string SpecString = Template->getNameAsString();
+  std::string SpecString;
+
+  {
+    llvm::raw_string_ostream OS(SpecString);
+    Template.Print(OS);
+  }
+
   SpecString += PrintTemplateArgumentList(getArgs(), getNumArgs());
   if (InnerString.empty())
     InnerString.swap(SpecString);
@@ -1515,7 +1519,7 @@ void TagType::getAsStringInternal(std::string &InnerString,
   if (ClassTemplateSpecializationDecl *Spec 
         = dyn_cast<ClassTemplateSpecializationDecl>(getDecl())) {
     std::string TemplateArgs 
-      = ClassTemplateSpecializationType::PrintTemplateArgumentList(
+      = TemplateSpecializationType::PrintTemplateArgumentList(
                                                   Spec->getTemplateArgs(),
                                                   Spec->getNumTemplateArgs());
     InnerString = TemplateArgs + InnerString;
@@ -1534,7 +1538,7 @@ void TagType::getAsStringInternal(std::string &InnerString,
       } else if (ClassTemplateSpecializationDecl *Spec 
                    = dyn_cast<ClassTemplateSpecializationDecl>(DC)) {
         std::string TemplateArgs 
-          = ClassTemplateSpecializationType::PrintTemplateArgumentList(
+          = TemplateSpecializationType::PrintTemplateArgumentList(
                                                   Spec->getTemplateArgs(),
                                                   Spec->getNumTemplateArgs());
         MyPart = Spec->getIdentifier()->getName() + TemplateArgs;
diff --git a/lib/AST/TypeSerialization.cpp b/lib/AST/TypeSerialization.cpp
index 4f0334f47a..0562416da0 100644
--- a/lib/AST/TypeSerialization.cpp
+++ b/lib/AST/TypeSerialization.cpp
@@ -391,29 +391,17 @@ Type* TemplateTypeParmType::CreateImpl(ASTContext& Context, Deserializer& D) {
 }
 
 //===----------------------------------------------------------------------===//
-// ClassTemplateSpecializationType
+// TemplateSpecializationType
 //===----------------------------------------------------------------------===//
 
-void ClassTemplateSpecializationType::EmitImpl(Serializer& S) const {
-  S.Emit(getCanonicalTypeInternal());
-  S.EmitPtr(Template);
-  S.EmitInt(NumArgs);
-  // FIXME: Serialize class template specialization types
+void TemplateSpecializationType::EmitImpl(Serializer& S) const {
+  // FIXME: Serialization support
 }
 
 Type* 
-ClassTemplateSpecializationType::
+TemplateSpecializationType::
 CreateImpl(ASTContext& Context, Deserializer& D) {
-  llvm::SmallVector<uintptr_t, 16> Args;
-  llvm::SmallVector<bool, 16> ArgIsType;
-
-  QualType Canon = QualType::ReadVal(D);
-  TemplateDecl *Template = cast<TemplateDecl>(D.ReadPtr<Decl>());
-  unsigned NumArgs = D.ReadInt();
-
-  // FIXME: De-serialize class template specialization types
-  (void)Template;
-  (void)NumArgs;
+  // FIXME: Deserialization support
   return 0;
 }
 
diff --git a/lib/CodeGen/CGDebugInfo.cpp b/lib/CodeGen/CGDebugInfo.cpp
index 7233bbf8e2..bde6fba137 100644
--- a/lib/CodeGen/CGDebugInfo.cpp
+++ b/lib/CodeGen/CGDebugInfo.cpp
@@ -561,7 +561,7 @@ llvm::DIType CGDebugInfo::getOrCreateType(QualType Ty,
   case Type::FixedWidthInt:
   case Type::BlockPointer:
   case Type::MemberPointer:
-  case Type::ClassTemplateSpecialization:
+  case Type::TemplateSpecialization:
   case Type::QualifiedName:
   case Type::ObjCQualifiedClass:
     // Unsupported types
diff --git a/lib/CodeGen/CodeGenTypes.cpp b/lib/CodeGen/CodeGenTypes.cpp
index 85d7384c6c..5367c71b2c 100644
--- a/lib/CodeGen/CodeGenTypes.cpp
+++ b/lib/CodeGen/CodeGenTypes.cpp
@@ -392,6 +392,9 @@ const llvm::Type *CodeGenTypes::ConvertNewType(QualType T) {
     // http://gcc.gnu.org/onlinedocs/gccint/Type-Layout.html#Type-Layout
     assert(0 && "FIXME: We can't handle member pointers yet.");
     return llvm::OpaqueType::get();
+
+  case Type::TemplateSpecialization:
+    assert(false && "Dependent types can't get here");
   }
   
   // FIXME: implement.
diff --git a/lib/Parse/MinimalAction.cpp b/lib/Parse/MinimalAction.cpp
index f31aef61d3..e99e96a7dc 100644
--- a/lib/Parse/MinimalAction.cpp
+++ b/lib/Parse/MinimalAction.cpp
@@ -135,7 +135,7 @@ bool MinimalAction::isCurrentClassName(const IdentifierInfo &, Scope *,
 
 TemplateNameKind 
 MinimalAction::isTemplateName(IdentifierInfo &II, Scope *S,
-                              DeclPtrTy &TemplateDecl,
+                              TemplateTy &TemplateDecl,
                               const CXXScopeSpec *SS) {
   return TNK_Non_template;
 }
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index 37a460cd41..fdfc7315a8 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -474,7 +474,7 @@ void Parser::ParseClassSpecifier(DeclSpec &DS,
     TagOrTempResult
       = Actions.ActOnClassTemplateSpecialization(CurScope, TagType, TK,
                        StartLoc, SS,
-                       DeclPtrTy::make(TemplateId->Template), 
+                       TemplateTy::make(TemplateId->Template), 
                        TemplateId->TemplateNameLoc, 
                        TemplateId->LAngleLoc, 
                        TemplateArgsPtr,
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index dc57ac141c..4d419bbd87 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -117,7 +117,7 @@ bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS) {
         // an operator and not as part of a simple-template-id.
       }
 
-      DeclPtrTy Template;
+      TemplateTy Template;
       TemplateNameKind TNK = TNK_Non_template;
       // FIXME: If the nested-name-specifier thus far is dependent,
       // set TNK = TNK_Dependent_template_name and skip the
diff --git a/lib/Parse/ParseTemplate.cpp b/lib/Parse/ParseTemplate.cpp
index b962cbf646..8eda694864 100644
--- a/lib/Parse/ParseTemplate.cpp
+++ b/lib/Parse/ParseTemplate.cpp
@@ -406,7 +406,7 @@ Parser::ParseNonTypeTemplateParameter(unsigned Depth, unsigned Position) {
 /// last token in the stream (e.g., so that it can be replaced with an
 /// annotation token).
 bool 
-Parser::ParseTemplateIdAfterTemplateName(DeclPtrTy Template,
+Parser::ParseTemplateIdAfterTemplateName(TemplateTy Template,
                                          SourceLocation TemplateNameLoc, 
                                          const CXXScopeSpec *SS,
                                          bool ConsumeLastToken,
@@ -499,7 +499,7 @@ Parser::ParseTemplateIdAfterTemplateName(DeclPtrTy Template,
 /// replaced with a type annotation token. Otherwise, the
 /// simple-template-id is always replaced with a template-id
 /// annotation token.
-void Parser::AnnotateTemplateIdToken(DeclPtrTy Template, TemplateNameKind TNK,
+void Parser::AnnotateTemplateIdToken(TemplateTy Template, TemplateNameKind TNK,
                                      const CXXScopeSpec *SS, 
                                      SourceLocation TemplateKWLoc,
                                      bool AllowTypeAnnotation) {
@@ -531,12 +531,13 @@ void Parser::AnnotateTemplateIdToken(DeclPtrTy Template, TemplateNameKind TNK,
     return; 
 
   // Build the annotation token.
+  // FIXME: Not just for class templates!
   if (TNK == TNK_Class_template && AllowTypeAnnotation) {
     Action::TypeResult Type 
-      = Actions.ActOnClassTemplateId(Template, TemplateNameLoc,
-                                     LAngleLoc, TemplateArgsPtr,
-                                     &TemplateArgLocations[0],
-                                     RAngleLoc, SS);
+      = Actions.ActOnTemplateIdType(Template, TemplateNameLoc,
+                                    LAngleLoc, TemplateArgsPtr,
+                                    &TemplateArgLocations[0],
+                                    RAngleLoc);
     if (Type.isInvalid()) // FIXME: better recovery?
       return;
 
@@ -603,12 +604,12 @@ bool Parser::AnnotateTemplateIdTokenAsType(const CXXScopeSpec *SS) {
                                      TemplateId->NumArgs);
 
   Action::TypeResult Type 
-    = Actions.ActOnClassTemplateId(DeclPtrTy::make(TemplateId->Template),
-                                   TemplateId->TemplateNameLoc,
-                                   TemplateId->LAngleLoc, 
-                                   TemplateArgsPtr,
-                                   TemplateId->getTemplateArgLocations(),
-                                   TemplateId->RAngleLoc, SS);
+    = Actions.ActOnTemplateIdType(TemplateTy::make(TemplateId->Template),
+                                  TemplateId->TemplateNameLoc,
+                                  TemplateId->LAngleLoc, 
+                                  TemplateArgsPtr,
+                                  TemplateId->getTemplateArgLocations(),
+                                  TemplateId->RAngleLoc);
   if (Type.isInvalid()) {
     // FIXME: better recovery?
     ConsumeToken();
diff --git a/lib/Parse/Parser.cpp b/lib/Parse/Parser.cpp
index b34c241fd1..a101aaa732 100644
--- a/lib/Parse/Parser.cpp
+++ b/lib/Parse/Parser.cpp
@@ -885,7 +885,7 @@ bool Parser::TryAnnotateTypeOrScopeToken() {
     
     // If this is a template-id, annotate with a template-id or type token.
     if (NextToken().is(tok::less)) {
-      DeclPtrTy Template;
+      TemplateTy Template;
       if (TemplateNameKind TNK 
             = Actions.isTemplateName(*Tok.getIdentifierInfo(),
                                      CurScope, Template, &SS))
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index b7903c1b59..c46b044c29 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1691,7 +1691,7 @@ public:
   // C++ Templates [C++ 14]
   //
   virtual TemplateNameKind isTemplateName(IdentifierInfo &II, Scope *S,
-                                          DeclPtrTy &TemplateDecl,
+                                          TemplateTy &Template,
                                           const CXXScopeSpec *SS = 0);
   bool DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl);
   TemplateDecl *AdjustDeclIfTemplate(DeclPtrTy &Decl);
@@ -1742,20 +1742,19 @@ public:
                      MultiTemplateParamsArg TemplateParameterLists,
                      AccessSpecifier AS);
 
-  QualType CheckClassTemplateId(ClassTemplateDecl *ClassTemplate,
-                                SourceLocation TemplateLoc,
-                                SourceLocation LAngleLoc,
-                                const TemplateArgument *TemplateArgs,
-                                unsigned NumTemplateArgs,
-                                SourceLocation RAngleLoc);
+  QualType CheckTemplateIdType(TemplateName Template,
+                               SourceLocation TemplateLoc,
+                               SourceLocation LAngleLoc,
+                               const TemplateArgument *TemplateArgs,
+                               unsigned NumTemplateArgs,
+                               SourceLocation RAngleLoc);
 
   virtual TypeResult
-  ActOnClassTemplateId(DeclPtrTy Template, SourceLocation TemplateLoc,
-                       SourceLocation LAngleLoc,
-                       ASTTemplateArgsPtr TemplateArgs,
-                       SourceLocation *TemplateArgLocs,
-                       SourceLocation RAngleLoc,
-                       const CXXScopeSpec *SS);
+  ActOnTemplateIdType(TemplateTy Template, SourceLocation TemplateLoc,
+                      SourceLocation LAngleLoc,
+                      ASTTemplateArgsPtr TemplateArgs,
+                      SourceLocation *TemplateArgLocs,
+                      SourceLocation RAngleLoc);
   
   bool CheckClassTemplateSpecializationScope(ClassTemplateDecl *ClassTemplate,
                                     ClassTemplateSpecializationDecl *PrevDecl,
@@ -1766,7 +1765,7 @@ public:
   ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec, TagKind TK,
                                    SourceLocation KWLoc, 
                                    const CXXScopeSpec &SS,
-                                   DeclPtrTy Template,
+                                   TemplateTy Template,
                                    SourceLocation TemplateNameLoc,
                                    SourceLocation LAngleLoc,
                                    ASTTemplateArgsPtr TemplateArgs,
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 773a2b1b92..56a016d270 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -27,19 +27,23 @@ using namespace clang;
 /// passed to indicate the C++ scope in which the identifier will be
 /// found. 
 TemplateNameKind Sema::isTemplateName(IdentifierInfo &II, Scope *S,
-                                      DeclPtrTy &Template,
+                                      TemplateTy &TemplateResult,
                                       const CXXScopeSpec *SS) {
   NamedDecl *IIDecl = LookupParsedName(S, SS, &II, LookupOrdinaryName);
 
+  TemplateNameKind TNK = TNK_Non_template;
+  TemplateDecl *Template = 0;
+
   if (IIDecl) {
-    if (isa<TemplateDecl>(IIDecl)) {
-      Template = DeclPtrTy::make(IIDecl);
+    if ((Template = dyn_cast<TemplateDecl>(IIDecl))) {
       if (isa<FunctionTemplateDecl>(IIDecl))
-        return TNK_Function_template;
-      if (isa<ClassTemplateDecl>(IIDecl))
-        return TNK_Class_template;
-      assert(isa<TemplateTemplateParmDecl>(IIDecl) && "Unknown TemplateDecl");
-      return TNK_Template_template_parm;
+        TNK = TNK_Function_template;
+      else if (isa<ClassTemplateDecl>(IIDecl))
+        TNK = TNK_Class_template;
+      else if (isa<TemplateTemplateParmDecl>(IIDecl))
+        TNK = TNK_Template_template_parm;
+      else
+        assert(false && "Unknown template declaration kind");
     } else if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(IIDecl)) {
       // C++ [temp.local]p1:
       //   Like normal (non-template) classes, class templates have an
@@ -54,12 +58,12 @@ TemplateNameKind Sema::isTemplateName(IdentifierInfo &II, Scope *S,
       //   specialization.
       if (Record->isInjectedClassName()) {
         Record = cast<CXXRecordDecl>(Context.getCanonicalDecl(Record));
-        if ((Template = DeclPtrTy::make(Record->getDescribedClassTemplate())))
-          return TNK_Class_template;
-        if (ClassTemplateSpecializationDecl *Spec
+        if ((Template = Record->getDescribedClassTemplate()))
+          TNK = TNK_Class_template;
+        else if (ClassTemplateSpecializationDecl *Spec
                    = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
-          Template = DeclPtrTy::make(Spec->getSpecializedTemplate());
-          return TNK_Class_template;
+          Template = Spec->getSpecializedTemplate();
+          TNK = TNK_Class_template;
         }
       }
     }
@@ -67,7 +71,7 @@ TemplateNameKind Sema::isTemplateName(IdentifierInfo &II, Scope *S,
     // FIXME: What follows is a gross hack.
     if (FunctionDecl *FD = dyn_cast<FunctionDecl>(IIDecl)) {
       if (FD->getType()->isDependentType()) {
-        Template = DeclPtrTy::make(FD);
+        TemplateResult = TemplateTy::make(FD);
         return TNK_Function_template;
       }
     } else if (OverloadedFunctionDecl *Ovl 
@@ -76,13 +80,25 @@ TemplateNameKind Sema::isTemplateName(IdentifierInfo &II, Scope *S,
                                                   FEnd = Ovl->function_end();
            F != FEnd; ++F) {
         if ((*F)->getType()->isDependentType()) {
-          Template = DeclPtrTy::make(Ovl);
+          TemplateResult = TemplateTy::make(Ovl);
           return TNK_Function_template;
         }
       }
     }
+
+    if (TNK != TNK_Non_template) {
+      if (SS && SS->isSet() && !SS->isInvalid()) {
+        NestedNameSpecifier *Qualifier 
+          = static_cast<NestedNameSpecifier *>(SS->getScopeRep());
+        TemplateResult 
+          = TemplateTy::make(Context.getQualifiedTemplateName(Qualifier, 
+                                                              false,
+                                                              Template));
+      } else
+        TemplateResult = TemplateTy::make(TemplateName(Template));
+    }
   }
-  return TNK_Non_template;
+  return TNK;
 }
 
 /// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
@@ -700,27 +716,30 @@ translateTemplateArguments(ASTTemplateArgsPtr &TemplateArgsIn,
   }
 }
 
-QualType Sema::CheckClassTemplateId(ClassTemplateDecl *ClassTemplate,
-                                    SourceLocation TemplateLoc,
-                                    SourceLocation LAngleLoc,
-                                    const TemplateArgument *TemplateArgs,
-                                    unsigned NumTemplateArgs,
-                                    SourceLocation RAngleLoc) {
+QualType Sema::CheckTemplateIdType(TemplateName Name,
+                                   SourceLocation TemplateLoc,
+                                   SourceLocation LAngleLoc,
+                                   const TemplateArgument *TemplateArgs,
+                                   unsigned NumTemplateArgs,
+                                   SourceLocation RAngleLoc) {
+  TemplateDecl *Template = Name.getAsTemplateDecl();
+  assert(Template && "Cannot handle dependent template-names yet");
+
   // Check that the template argument list is well-formed for this
   // template.
   llvm::SmallVector<TemplateArgument, 16> ConvertedTemplateArgs;
-  if (CheckTemplateArgumentList(ClassTemplate, TemplateLoc, LAngleLoc, 
+  if (CheckTemplateArgumentList(Template, TemplateLoc, LAngleLoc, 
                                 TemplateArgs, NumTemplateArgs, RAngleLoc,
                                 ConvertedTemplateArgs))
     return QualType();
 
   assert((ConvertedTemplateArgs.size() == 
-            ClassTemplate->getTemplateParameters()->size()) &&
+            Template->getTemplateParameters()->size()) &&
          "Converted template argument list is too short!");
 
   QualType CanonType;
 
-  if (ClassTemplateSpecializationType::anyDependentTemplateArguments(
+  if (TemplateSpecializationType::anyDependentTemplateArguments(
                                                       TemplateArgs,
                                                       NumTemplateArgs)) {
     // This class template specialization is a dependent
@@ -731,10 +750,11 @@ QualType Sema::CheckClassTemplateId(ClassTemplateDecl *ClassTemplate,
     //
     //   template<typename T, typename U = T> struct A;
 
-    CanonType = Context.getClassTemplateSpecializationType(ClassTemplate, 
+    CanonType = Context.getTemplateSpecializationType(Name, 
                                                     &ConvertedTemplateArgs[0],
                                                 ConvertedTemplateArgs.size());
-  } else {
+  } else if (ClassTemplateDecl *ClassTemplate 
+               = dyn_cast<ClassTemplateDecl>(Template)) {
     // Find the class template specialization declaration that
     // corresponds to these arguments.
     llvm::FoldingSetNodeID ID;
@@ -764,35 +784,26 @@ QualType Sema::CheckClassTemplateId(ClassTemplateDecl *ClassTemplate,
   // Build the fully-sugared type for this class template
   // specialization, which refers back to the class template
   // specialization we created or found.
-  return Context.getClassTemplateSpecializationType(ClassTemplate, 
-                                                    TemplateArgs,
-                                                    NumTemplateArgs, 
-                                                    CanonType);
+  return Context.getTemplateSpecializationType(Name, TemplateArgs,
+                                               NumTemplateArgs, CanonType);
 }
 
 Action::TypeResult
-Sema::ActOnClassTemplateId(DeclPtrTy TemplateD, SourceLocation TemplateLoc,
-                           SourceLocation LAngleLoc, 
-                           ASTTemplateArgsPtr TemplateArgsIn,
-                           SourceLocation *TemplateArgLocs,
-                           SourceLocation RAngleLoc,
-                           const CXXScopeSpec *SS) {
-  TemplateDecl *Template = cast<TemplateDecl>(TemplateD.getAs<Decl>());
-  ClassTemplateDecl *ClassTemplate = cast<ClassTemplateDecl>(Template);
+Sema::ActOnTemplateIdType(TemplateTy TemplateD, SourceLocation TemplateLoc,
+                          SourceLocation LAngleLoc, 
+                          ASTTemplateArgsPtr TemplateArgsIn,
+                          SourceLocation *TemplateArgLocs,
+                          SourceLocation RAngleLoc) {
+  TemplateName Template = TemplateD.getAsVal<TemplateName>();
 
   // Translate the parser's template argument list in our AST format.
   llvm::SmallVector<TemplateArgument, 16> TemplateArgs;
   translateTemplateArguments(TemplateArgsIn, TemplateArgLocs, TemplateArgs);
 
-  QualType Result = CheckClassTemplateId(ClassTemplate, TemplateLoc,