Remove broken support for variadic templates, along with the various

abstractions (e.g., TemplateArgumentListBuilder) that were designed to
support variadic templates. Only a few remnants of variadic templates
remain, in the parser (parsing template type parameter packs), AST
(template type parameter pack bits and TemplateArgument::Pack), and
Sema; these are expected to be used in a future implementation of
variadic templates.

But don't get too excited about that happening now.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118385 91177308-0d34-0410-b5e6-96231b3b80d8

24 files changed, 257 insertions, 461 deletions

diff --git a/include/clang/AST/DeclTemplate.h b/include/clang/AST/DeclTemplate.h
index 96ab4a8a1c..bde2e24e19 100644
--- a/include/clang/AST/DeclTemplate.h
+++ b/include/clang/AST/DeclTemplate.h
@@ -85,7 +85,7 @@ public:
     return begin()[Idx];
   }
 
-  /// \btief Returns the minimum number of arguments needed to form a
+  /// \brief Returns the minimum number of arguments needed to form a
   /// template specialization. This may be fewer than the number of
   /// template parameters, if some of the parameters have default
   /// arguments or if there is a parameter pack.
@@ -107,101 +107,57 @@ public:
   }
 };
 
-/// \brief A helper class for making template argument lists.
-class TemplateArgumentListBuilder {
-  TemplateArgument *StructuredArgs;
-  unsigned MaxStructuredArgs;
-  unsigned NumStructuredArgs;
-
-  llvm::SmallVector<TemplateArgument, 4> FlatArgs;
-  unsigned MaxFlatArgs;
-  unsigned NumFlatArgs;
-
-  bool AddingToPack;
-  unsigned PackBeginIndex;
-
-public:
-  TemplateArgumentListBuilder(const TemplateParameterList *Parameters,
-                              unsigned NumTemplateArgs)
-  : StructuredArgs(0), MaxStructuredArgs(Parameters->size()),
-  NumStructuredArgs(0), FlatArgs(0),
-  MaxFlatArgs(std::max(MaxStructuredArgs, NumTemplateArgs)), NumFlatArgs(0),
-  AddingToPack(false), PackBeginIndex(0) { }
-
-  void Append(const TemplateArgument &Arg);
-  void BeginPack();
-  void EndPack();
-
-  unsigned flatSize() const { return FlatArgs.size(); }
-  const TemplateArgument *getFlatArguments() const { return FlatArgs.data(); }
-
-  unsigned structuredSize() const {
-    // If we don't have any structured args, just reuse the flat size.
-    if (!StructuredArgs)
-      return flatSize();
-
-    return NumStructuredArgs;
-  }
-  const TemplateArgument *getStructuredArguments() const {
-    // If we don't have any structured args, just reuse the flat args.
-    if (!StructuredArgs)
-      return getFlatArguments();
-
-    return StructuredArgs;
-  }
-};
-
 /// \brief A template argument list.
-///
-/// FIXME: In the future, this class will be extended to support
-/// variadic templates and member templates, which will make some of
-/// the function names below make more sense.
 class TemplateArgumentList {
   /// \brief The template argument list.
   ///
   /// The integer value will be non-zero to indicate that this
   /// template argument list does own the pointer.
-  llvm::PointerIntPair<const TemplateArgument *, 1> FlatArguments;
+  llvm::PointerIntPair<const TemplateArgument *, 1> Arguments;
 
   /// \brief The number of template arguments in this template
   /// argument list.
-  unsigned NumFlatArguments;
-
-  llvm::PointerIntPair<const TemplateArgument *, 1> StructuredArguments;
-  unsigned NumStructuredArguments;
+  unsigned NumArguments;
 
   TemplateArgumentList(const TemplateArgumentList &Other); // DO NOT IMPL
   void operator=(const TemplateArgumentList &Other); // DO NOT IMPL
+
+  TemplateArgumentList(const TemplateArgument *Args, unsigned NumArgs,
+                       bool Owned)
+    : Arguments(Args, Owned), NumArguments(NumArgs) { }
+
 public:
-  /// TemplateArgumentList - If this constructor is passed "true" for 'TakeArgs'
-  /// it copies them into a locally new[]'d array.  If passed "false", then it
-  /// just references the array passed in.  This is only safe if the builder
-  /// outlives it, but saves a copy.
-  TemplateArgumentList(ASTContext &Context,
-                       TemplateArgumentListBuilder &Builder,
-                       bool TakeArgs);
-
-  /// TemplateArgumentList - It copies the template arguments into a locally
-  /// new[]'d array.
-  TemplateArgumentList(ASTContext &Context,
-                       const TemplateArgument *Args, unsigned NumArgs);
-
-  /// Produces a shallow copy of the given template argument list.  This
-  /// assumes that the input argument list outlives it.  This takes the list as
-  /// a pointer to avoid looking like a copy constructor, since this really
-  /// really isn't safe to use that way.
-  explicit TemplateArgumentList(const TemplateArgumentList *Other);
-
-  TemplateArgumentList() : NumFlatArguments(0), NumStructuredArguments(0) { }
-
-  /// \brief Copies the template arguments into a locally new[]'d array.
-  void init(ASTContext &Context,
-            const TemplateArgument *Args, unsigned NumArgs);
+  /// \brief Type used to indicate that the template argument list itself is a 
+  /// stack object. It does not own its template arguments.
+  enum OnStackType { OnStack };
+
+  /// \brief Create a new template argument list that copies the given set of
+  /// template arguments.
+  static TemplateArgumentList *CreateCopy(ASTContext &Context,
+                                          const TemplateArgument *Args,
+                                          unsigned NumArgs);
+
+  /// \brief Construct a new, temporary template argument list on the stack.
+  ///
+  /// The template argument list does not own the template arguments
+  /// provided.
+  explicit TemplateArgumentList(OnStackType, 
+                                const TemplateArgument *Args, unsigned NumArgs)
+    : Arguments(Args, false), NumArguments(NumArgs) { }
+                                
+  /// \brief Produces a shallow copy of the given template argument list.  
+  /// 
+  /// This operation assumes that the input argument list outlives it.
+  /// This takes the list as a pointer to avoid looking like a copy
+  /// constructor, since this really really isn't safe to use that
+  /// way.
+  explicit TemplateArgumentList(const TemplateArgumentList *Other)
+    : Arguments(Other->data(), false), NumArguments(Other->size()) { }
 
   /// \brief Retrieve the template argument at a given index.
   const TemplateArgument &get(unsigned Idx) const {
-    assert(Idx < NumFlatArguments && "Invalid template argument index");
-    return getFlatArgumentList()[Idx];
+    assert(Idx < NumArguments && "Invalid template argument index");
+    return data()[Idx];
   }
 
   /// \brief Retrieve the template argument at a given index.
@@ -209,15 +165,11 @@ public:
 
   /// \brief Retrieve the number of template arguments in this
   /// template argument list.
-  unsigned size() const { return NumFlatArguments; }
-
-  /// \brief Retrieve the number of template arguments in the
-  /// flattened template argument list.
-  unsigned flat_size() const { return NumFlatArguments; }
+  unsigned size() const { return NumArguments; }
 
-  /// \brief Retrieve the flattened template argument list.
-  const TemplateArgument *getFlatArgumentList() const {
-    return FlatArguments.getPointer();
+  /// \brief Retrieve a pointer to the template argument list.
+  const TemplateArgument *data() const {
+    return Arguments.getPointer();
   }
 };
 
@@ -369,8 +321,8 @@ public:
   }
   
   void Profile(llvm::FoldingSetNodeID &ID) {
-    Profile(ID, TemplateArguments->getFlatArgumentList(),
-            TemplateArguments->flat_size(),
+    Profile(ID, TemplateArguments->data(),
+            TemplateArguments->size(),
             Function->getASTContext());
   }
 
@@ -1229,7 +1181,7 @@ class ClassTemplateSpecializationDecl
   ExplicitSpecializationInfo *ExplicitInfo;
 
   /// \brief The template arguments used to describe this specialization.
-  TemplateArgumentList TemplateArgs;
+  TemplateArgumentList *TemplateArgs;
 
   /// \brief The point where this template was instantiated (if any)
   SourceLocation PointOfInstantiation;
@@ -1242,7 +1194,8 @@ protected:
   ClassTemplateSpecializationDecl(ASTContext &Context, Kind DK, TagKind TK,
                                   DeclContext *DC, SourceLocation L,
                                   ClassTemplateDecl *SpecializedTemplate,
-                                  TemplateArgumentListBuilder &Builder,
+                                  const TemplateArgument *Args,
+                                  unsigned NumArgs,
                                   ClassTemplateSpecializationDecl *PrevDecl);
 
   explicit ClassTemplateSpecializationDecl(Kind DK);
@@ -1251,7 +1204,8 @@ public:
   static ClassTemplateSpecializationDecl *
   Create(ASTContext &Context, TagKind TK, DeclContext *DC, SourceLocation L,
          ClassTemplateDecl *SpecializedTemplate,
-         TemplateArgumentListBuilder &Builder,
+         const TemplateArgument *Args,
+         unsigned NumArgs,
          ClassTemplateSpecializationDecl *PrevDecl);
   static ClassTemplateSpecializationDecl *
   Create(ASTContext &Context, EmptyShell Empty);
@@ -1277,7 +1231,7 @@ public:
   /// \brief Retrieve the template arguments of the class template
   /// specialization.
   const TemplateArgumentList &getTemplateArgs() const {
-    return TemplateArgs;
+    return *TemplateArgs;
   }
 
   /// \brief Determine the kind of specialization that this
@@ -1413,8 +1367,7 @@ public:
   SourceLocation getInnerLocStart() const { return getTemplateKeywordLoc(); }
 
   void Profile(llvm::FoldingSetNodeID &ID) const {
-    Profile(ID, TemplateArgs.getFlatArgumentList(), TemplateArgs.flat_size(),
-            getASTContext());
+    Profile(ID, TemplateArgs->data(), TemplateArgs->size(), getASTContext());
   }
 
   static void
@@ -1470,15 +1423,16 @@ class ClassTemplatePartialSpecializationDecl
                                          DeclContext *DC, SourceLocation L,
                                          TemplateParameterList *Params,
                                          ClassTemplateDecl *SpecializedTemplate,
-                                         TemplateArgumentListBuilder &Builder,
+                                         const TemplateArgument *Args,
+                                         unsigned NumArgs,
                                          TemplateArgumentLoc *ArgInfos,
                                          unsigned NumArgInfos,
                                ClassTemplatePartialSpecializationDecl *PrevDecl,
                                          unsigned SequenceNumber)
     : ClassTemplateSpecializationDecl(Context,
                                       ClassTemplatePartialSpecialization,
-                                      TK, DC, L, SpecializedTemplate, Builder,
-                                      PrevDecl),
+                                      TK, DC, L, SpecializedTemplate, 
+                                      Args, NumArgs, PrevDecl),
       TemplateParams(Params), ArgsAsWritten(ArgInfos),
       NumArgsAsWritten(NumArgInfos), SequenceNumber(SequenceNumber),
       InstantiatedFromMember(0, false) { }
@@ -1494,7 +1448,8 @@ public:
   Create(ASTContext &Context, TagKind TK,DeclContext *DC, SourceLocation L,
          TemplateParameterList *Params,
          ClassTemplateDecl *SpecializedTemplate,
-         TemplateArgumentListBuilder &Builder,
+         const TemplateArgument *Args,
+         unsigned NumArgs,
          const TemplateArgumentListInfo &ArgInfos,
          QualType CanonInjectedType,
          ClassTemplatePartialSpecializationDecl *PrevDecl,
diff --git a/include/clang/AST/TemplateBase.h b/include/clang/AST/TemplateBase.h
index 7d5123fb04..3d16ac8e84 100644
--- a/include/clang/AST/TemplateBase.h
+++ b/include/clang/AST/TemplateBase.h
@@ -44,7 +44,6 @@ class TemplateArgument {
     struct {
       TemplateArgument *Args;
       unsigned NumArgs;
-      bool CopyArgs;
     } Args;
   };
 
@@ -92,6 +91,8 @@ public:
 
   /// \brief Construct an integral constant template argument.
   TemplateArgument(const llvm::APSInt &Value, QualType Type) : Kind(Integral) {
+    // FIXME: Large integral values will get leaked. Do something
+    // similar to what we did with IntegerLiteral.
     new (Integer.Value) llvm::APSInt(Value);
     Integer.Type = Type.getAsOpaquePtr();
   }
@@ -115,46 +116,54 @@ public:
     TypeOrValue = reinterpret_cast<uintptr_t>(E);
   }
 
+  /// \brief Construct a template argument that is a template argument pack.
+  ///
+  /// We assume that storage for the template arguments provided
+  /// outlives the TemplateArgument itself.
+  TemplateArgument(TemplateArgument *Args, unsigned NumArgs) : Kind(Pack) {
+    this->Args.Args = Args;
+    this->Args.NumArgs = NumArgs;
+  }
+
   /// \brief Copy constructor for a template argument.
   TemplateArgument(const TemplateArgument &Other) : Kind(Other.Kind) {
+    // FIXME: Large integral values will get leaked. Do something
+    // similar to what we did with IntegerLiteral.
     if (Kind == Integral) {
       new (Integer.Value) llvm::APSInt(*Other.getAsIntegral());
       Integer.Type = Other.Integer.Type;
     } else if (Kind == Pack) {
       Args.NumArgs = Other.Args.NumArgs;
-      Args.Args = new TemplateArgument[Args.NumArgs];
-      for (unsigned I = 0; I != Args.NumArgs; ++I)
-        Args.Args[I] = Other.Args.Args[I];
+      Args.Args = Other.Args.Args;
     }
     else
       TypeOrValue = Other.TypeOrValue;
   }
 
   TemplateArgument& operator=(const TemplateArgument& Other) {
-    // FIXME: Does not provide the strong guarantee for exception
-    // safety.
     using llvm::APSInt;
 
-    // FIXME: Handle Packs
-    assert(Kind != Pack && "FIXME: Handle packs");
-    assert(Other.Kind != Pack && "FIXME: Handle packs");
-
     if (Kind == Other.Kind && Kind == Integral) {
       // Copy integral values.
       *this->getAsIntegral() = *Other.getAsIntegral();
       Integer.Type = Other.Integer.Type;
-    } else {
-      // Destroy the current integral value, if that's what we're holding.
-      if (Kind == Integral)
-        getAsIntegral()->~APSInt();
+      return *this;
+    } 
+
+    // Destroy the current integral value, if that's what we're holding.
+    if (Kind == Integral)
+      getAsIntegral()->~APSInt();
 
-      Kind = Other.Kind;
+    Kind = Other.Kind;
 
-      if (Other.Kind == Integral) {
-        new (Integer.Value) llvm::APSInt(*Other.getAsIntegral());
-        Integer.Type = Other.Integer.Type;
-      } else
-        TypeOrValue = Other.TypeOrValue;
+    if (Other.Kind == Integral) {
+      new (Integer.Value) llvm::APSInt(*Other.getAsIntegral());
+      Integer.Type = Other.Integer.Type;
+    } else if (Other.Kind == Pack) {
+      Args.NumArgs = Other.Args.NumArgs;
+      Args.Args = Other.Args.Args;
+    } else {
+      TypeOrValue = Other.TypeOrValue;
     }
 
     return *this;
@@ -165,8 +174,6 @@ public:
 
     if (Kind == Integral)
       getAsIntegral()->~APSInt();
-    else if (Kind == Pack && Args.CopyArgs)
-      delete[] Args.Args;
   }
 
   /// \brief Return the kind of stored template argument.
@@ -260,9 +267,6 @@ public:
   /// same.
   bool structurallyEquals(const TemplateArgument &Other) const;
 
-  /// \brief Construct a template argument pack.
-  void setArgumentPack(TemplateArgument *Args, unsigned NumArgs, bool CopyArgs);
-
   /// \brief Used to insert TemplateArguments into FoldingSets.
   void Profile(llvm::FoldingSetNodeID &ID, ASTContext &Context) const;
 };
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index a5b0aa5ec1..8f36ec9db0 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1769,6 +1769,8 @@ def ext_template_outside_of_template : ExtWarn<
   "'template' keyword outside of a template">;
 
 // C++0x Variadic Templates
+def err_variadic_templates_unsupported : Error<
+  "variadic templates are not yet implemented">;
 def err_template_param_pack_default_arg : Error<
   "template parameter pack cannot have a default argument">;
 def err_template_param_pack_must_be_last_template_parameter : Error<
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 54357eb1da..8e99ca1eb3 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -121,7 +121,6 @@ namespace clang {
   class TargetAttributesSema;
   class TemplateArgument;
   class TemplateArgumentList;
-  class TemplateArgumentListBuilder;
   class TemplateArgumentLoc;
   class TemplateDecl;
   class TemplateParameterList;
@@ -2883,7 +2882,7 @@ public:
 
   bool CheckClassTemplatePartialSpecializationArgs(
                                         TemplateParameterList *TemplateParams,
-                              const TemplateArgumentListBuilder &TemplateArgs,
+                        llvm::SmallVectorImpl<TemplateArgument> &TemplateArgs,
                                         bool &MirrorsPrimaryTemplate);
 
   DeclResult
@@ -2958,7 +2957,7 @@ public:
                                           SourceLocation TemplateLoc,
                                           SourceLocation RAngleLoc,
                                           Decl *Param,
-                                      TemplateArgumentListBuilder &Converted);
+                          llvm::SmallVectorImpl<TemplateArgument> &Converted);
 
   /// \brief Specifies the context in which a particular template
   /// argument is being checked.
@@ -2981,18 +2980,18 @@ public:
                              TemplateDecl *Template,
                              SourceLocation TemplateLoc,
                              SourceLocation RAngleLoc,
-                             TemplateArgumentListBuilder &Converted,
+                           llvm::SmallVectorImpl<TemplateArgument> &Converted,
                              CheckTemplateArgumentKind CTAK = CTAK_Specified);
 
   bool CheckTemplateArgumentList(TemplateDecl *Template,
                                  SourceLocation TemplateLoc,
                                  const TemplateArgumentListInfo &TemplateArgs,
                                  bool PartialTemplateArgs,
-                                 TemplateArgumentListBuilder &Converted);
+                           llvm::SmallVectorImpl<TemplateArgument> &Converted);
 
   bool CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
                                  const TemplateArgumentLoc &Arg,
-                                 TemplateArgumentListBuilder &Converted);
+                           llvm::SmallVectorImpl<TemplateArgument> &Converted);
 
   bool CheckTemplateArgument(TemplateTypeParmDecl *Param,
                              TypeSourceInfo *Arg);
diff --git a/include/clang/Sema/Template.h b/include/clang/Sema/Template.h
index a7b3b84618..23f1438f37 100644
--- a/include/clang/Sema/Template.h
+++ b/include/clang/Sema/Template.h
@@ -82,9 +82,8 @@ namespace clang {
     /// \brief Add a new outermost level to the multi-level template argument 
     /// list.
     void addOuterTemplateArguments(const TemplateArgumentList *TemplateArgs) {
-      TemplateArgumentLists.push_back(
-                                    ArgList(TemplateArgs->getFlatArgumentList(),
-                                            TemplateArgs->flat_size()));
+      TemplateArgumentLists.push_back(ArgList(TemplateArgs->data(),
+                                              TemplateArgs->size()));
     }
     
     /// \brief Add a new outmost level to the multi-level template argument
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 8f87b2f23b..b2451a2d86 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -2684,17 +2684,15 @@ ASTContext::getCanonicalTemplateArgument(const TemplateArgument &Arg) {
       return TemplateArgument(getCanonicalType(Arg.getAsType()));
 
     case TemplateArgument::Pack: {
-      // FIXME: Allocate in ASTContext
-      TemplateArgument *CanonArgs = new TemplateArgument[Arg.pack_size()];
+      TemplateArgument *CanonArgs
+        = new (*this) TemplateArgument[Arg.pack_size()];
       unsigned Idx = 0;
       for (TemplateArgument::pack_iterator A = Arg.pack_begin(),
                                         AEnd = Arg.pack_end();
            A != AEnd; (void)++A, ++Idx)
         CanonArgs[Idx] = getCanonicalTemplateArgument(*A);
 
-      TemplateArgument Result;
-      Result.setArgumentPack(CanonArgs, Arg.pack_size(), false);
-      return Result;
+      return TemplateArgument(CanonArgs, Arg.pack_size());
     }
   }
 
@@ -3897,8 +3895,8 @@ void ASTContext::getObjCEncodingForTypeImpl(QualType T, std::string& S,
         const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
         std::string TemplateArgsStr
           = TemplateSpecializationType::PrintTemplateArgumentList(
-                                            TemplateArgs.getFlatArgumentList(),
-                                            TemplateArgs.flat_size(),
+                                            TemplateArgs.data(),
+                                            TemplateArgs.size(),
                                             (*this).PrintingPolicy);
 
         S += TemplateArgsStr;
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index c88f79b29f..c448116ed2 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -164,8 +164,7 @@ static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
 
 static LVPair
 getLVForTemplateArgumentList(const TemplateArgumentList &TArgs) {
-  return getLVForTemplateArgumentList(TArgs.getFlatArgumentList(), 
-                                      TArgs.flat_size());
+  return getLVForTemplateArgumentList(TArgs.data(), TArgs.size());
 }
 
 /// getLVForDecl - Get the cached linkage and visibility for the given
@@ -650,8 +649,8 @@ std::string NamedDecl::getQualifiedNameAsString(const PrintingPolicy &P) const {
       const TemplateArgumentList &TemplateArgs = Spec->getTemplateArgs();
       std::string TemplateArgsStr
         = TemplateSpecializationType::PrintTemplateArgumentList(
-                                           TemplateArgs.getFlatArgumentList(),
-                                           TemplateArgs.flat_size(),
+                                           TemplateArgs.data(),
+                                           TemplateArgs.size(),
                                            P);
       OS << Spec->getName() << TemplateArgsStr;
     } else if (const NamespaceDecl *ND = dyn_cast<NamespaceDecl>(*I)) {
@@ -1161,8 +1160,8 @@ void FunctionDecl::getNameForDiagnostic(std::string &S,
   const TemplateArgumentList *TemplateArgs = getTemplateSpecializationArgs();
   if (TemplateArgs)
     S += TemplateSpecializationType::PrintTemplateArgumentList(
-                                         TemplateArgs->getFlatArgumentList(),
-                                         TemplateArgs->flat_size(),
+                                                         TemplateArgs->data(),
+                                                         TemplateArgs->size(),
                                                                Policy);
     
 }
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index c07d832073..cce434364f 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -19,6 +19,7 @@
 #include "clang/AST/ASTMutationListener.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "llvm/ADT/STLExtras.h"
+#include <memory>
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -394,120 +395,20 @@ TemplateTemplateParmDecl::Create(ASTContext &C, DeclContext *DC,
 }
 
 //===----------------------------------------------------------------------===//
-// TemplateArgumentListBuilder Implementation
-//===----------------------------------------------------------------------===//
-
-void TemplateArgumentListBuilder::Append(const TemplateArgument &Arg) {
-  assert((Arg.getKind() != TemplateArgument::Type ||
-          Arg.getAsType().isCanonical()) && "Type must be canonical!");
-  assert(FlatArgs.size() < MaxFlatArgs && "Argument list builder is full!");
-  assert(!StructuredArgs &&
-         "Can't append arguments when an argument pack has been added!");
-
-  FlatArgs.push_back(Arg);
-}
-
-void TemplateArgumentListBuilder::BeginPack() {
-  assert(!AddingToPack && "Already adding to pack!");
-  assert(!StructuredArgs && "Argument list already contains a pack!");
-
-  AddingToPack = true;
-  PackBeginIndex = FlatArgs.size();
-}
-
-void TemplateArgumentListBuilder::EndPack() {
-  assert(AddingToPack && "Not adding to pack!");
-  assert(!StructuredArgs && "Argument list already contains a pack!");
-
-  AddingToPack = false;
-
-  // FIXME: This is a memory leak!
-  StructuredArgs = new TemplateArgument[MaxStructuredArgs];
-
-  // First copy the flat entries over to the list  (if any)
-  for (unsigned I = 0; I != PackBeginIndex; ++I) {
-    NumStructuredArgs++;
-    StructuredArgs[I] = FlatArgs[I];
-  }
-
-  // Next, set the pack.
-  TemplateArgument *PackArgs = 0;
-  unsigned NumPackArgs = NumFlatArgs - PackBeginIndex;
-  // FIXME: NumPackArgs shouldn't be negative here???
-  if (NumPackArgs)
-    PackArgs = FlatArgs.data()+PackBeginIndex;
-
-  StructuredArgs[NumStructuredArgs++].setArgumentPack(PackArgs, NumPackArgs,
-                                                      /*CopyArgs=*/false);
-}
-
-//===----------------------------------------------------------------------===//
 // TemplateArgumentList Implementation
 //===----------------------------------------------------------------------===//
-TemplateArgumentList::TemplateArgumentList(ASTContext &Context,
-                                           TemplateArgumentListBuilder &Builder,
-                                           bool TakeArgs)
-  : FlatArguments(Builder.getFlatArguments(), TakeArgs),
-    NumFlatArguments(Builder.flatSize()),
-    StructuredArguments(Builder.getStructuredArguments(), TakeArgs),
-    NumStructuredArguments(Builder.structuredSize()) {
-
-  if (!TakeArgs)
-    return;
-
-  // If this does take ownership of the arguments, then we have to new them
-  // and copy over.
-  TemplateArgument *NewArgs =
-    new (Context) TemplateArgument[Builder.flatSize()];
-  std::copy(Builder.getFlatArguments(),
-            Builder.getFlatArguments()+Builder.flatSize(), NewArgs);
-  FlatArguments.setPointer(NewArgs);
-      
-  // Just reuse the structured and flat arguments array if possible.
-  if (Builder.getStructuredArguments() == Builder.getFlatArguments()) {
-    StructuredArguments.setPointer(NewArgs);    
-    StructuredArguments.setInt(0);
-  } else {
-    TemplateArgument *NewSArgs =
-      new (Context) TemplateArgument[Builder.flatSize()];
-    std::copy(Builder.getFlatArguments(),
-              Builder.getFlatArguments()+Builder.flatSize(), NewSArgs);
-    StructuredArguments.setPointer(NewSArgs);
-  }
-}
-
-TemplateArgumentList::TemplateArgumentList(ASTContext &Context,
-                                           const TemplateArgument *Args,
-                                           unsigned NumArgs)
-  : NumFlatArguments(0), NumStructuredArguments(0) {
-  init(Context, Args, NumArgs);
-}
-
-/// Produces a shallow copy of the given template argument list.  This
-/// assumes that the input argument list outlives it.  This takes the list as
-/// a pointer to avoid looking like a copy constructor, since this really
-/// really isn't safe to use that way.
-TemplateArgumentList::TemplateArgumentList(const TemplateArgumentList *Other)
-  : FlatArguments(Other->FlatArguments.getPointer(), false),
-    NumFlatArguments(Other->flat_size()),
-    StructuredArguments(Other->StructuredArguments.getPointer(), false),
-    NumStructuredArguments(Other->NumStructuredArguments) { }
-
-void TemplateArgumentList::init(ASTContext &Context,
-                           const TemplateArgument *Args,
-                           unsigned NumArgs) {
-assert(NumFlatArguments == 0 && NumStructuredArguments == 0 &&
-       "Already initialized!");
-
-NumFlatArguments = NumStructuredArguments = NumArgs;
-TemplateArgument *NewArgs = new (Context) TemplateArgument[NumArgs];
-std::copy(Args, Args+NumArgs, NewArgs);
-FlatArguments.setPointer(NewArgs);
-FlatArguments.setInt(1); // Owns the pointer.
-
-// Just reuse the flat arguments array.
-StructuredArguments.setPointer(NewArgs);    
-StructuredArguments.setInt(0); // Doesn't own the pointer.
+TemplateArgumentList *
+TemplateArgumentList::CreateCopy(ASTContext &Context,
+                                 const TemplateArgument *Args,
+                                 unsigned NumArgs) {
+  std::size_t Size = sizeof(TemplateArgumentList)
+                   + NumArgs * sizeof(TemplateArgument);
+  void *Mem = Context.Allocate(Size);
+  TemplateArgument *StoredArgs 
+    = reinterpret_cast<TemplateArgument *>(
+                                static_cast<TemplateArgumentList *>(Mem) + 1);
+  std::uninitialized_copy(Args, Args + NumArgs, StoredArgs);
+  return new (Mem) TemplateArgumentList(StoredArgs, NumArgs, true);
 }
 
 //===----------------------------------------------------------------------===//
@@ -517,14 +418,15 @@ ClassTemplateSpecializationDecl::
 ClassTemplateSpecializationDecl(ASTContext &Context, Kind DK, TagKind TK,
                                 DeclContext *DC, SourceLocation L,
                                 ClassTemplateDecl *SpecializedTemplate,
-                                TemplateArgumentListBuilder &Builder,
+                                const TemplateArgument *Args,
+                                unsigned NumArgs,
                                 ClassTemplateSpecializationDecl *PrevDecl)
   : CXXRecordDecl(DK, TK, DC, L,
                   SpecializedTemplate->getIdentifier(),
                   PrevDecl),
     SpecializedTemplate(SpecializedTemplate),
     ExplicitInfo(0),
-    TemplateArgs(Context, Builder, /*TakeArgs=*/true),
+    TemplateArgs(TemplateArgumentList::CreateCopy(Context, Args, NumArgs)),
     SpecializationKind(TSK_Undeclared) {
 }
 
@@ -538,14 +440,15 @@ ClassTemplateSpecializationDecl *
 ClassTemplateSpecializationDecl::Create(ASTContext &Context, TagKind TK,
                                         DeclContext *DC, SourceLocation L,
                                         ClassTemplateDecl *SpecializedTemplate,
-                                        TemplateArgumentListBuilder &Builder,
+                                        const TemplateArgument *Args,
+                                        unsigned NumArgs,
                                    ClassTemplateSpecializationDecl *PrevDecl) {
   ClassTemplateSpecializationDecl *Result
     = new (Context)ClassTemplateSpecializationDecl(Context,
                                                    ClassTemplateSpecialization,
                                                    TK, DC, L,
                                                    SpecializedTemplate,
-                                                   Builder,
+                                                   Args, NumArgs,
                                                    PrevDecl);
   Context.getTypeDeclType(Result, PrevDecl);
   return Resu