1 files changed, 44 insertions, 11 deletions

diff --git a/include/clang/AST/TemplateBase.h b/include/clang/AST/TemplateBase.h
index 93ec35bebe..a4e074e083 100644
--- a/include/clang/AST/TemplateBase.h
+++ b/include/clang/AST/TemplateBase.h
@@ -80,8 +80,14 @@ private:
       const TemplateArgument *Args;
       unsigned NumArgs;
     } Args;
+    struct {
+      void *Name;
+      unsigned NumExpansions;
+    } TemplateArg;
   };
 
+  TemplateArgument(TemplateName, bool); // DO NOT USE
+  
 public:
   /// \brief Construct an empty, invalid template argument.
   TemplateArgument() : Kind(Null), TypeOrValue(0) { }
@@ -107,8 +113,7 @@ public:
     Integer.Type = Type.getAsOpaquePtr();
   }
 
-  /// \brief Construct a template argument that is a template or a pack
-  /// expansion of templates.
+  /// \brief Construct a template argument that is a template.
   ///
   /// This form of template argument is generally used for template template
   /// parameters. However, the template name could be a dependent template
@@ -116,13 +121,33 @@ public:
   /// is taken.
   ///
   /// \param Name The template name.
-  /// \param PackExpansion Whether this template argument is a pack expansion.
-  TemplateArgument(TemplateName Name, bool PackExpansion = false) 
-    : Kind(PackExpansion? TemplateExpansion : Template) 
+  TemplateArgument(TemplateName Name) : Kind(Template) 
   {
-    TypeOrValue = reinterpret_cast<uintptr_t>(Name.getAsVoidPointer());
+    TemplateArg.Name = Name.getAsVoidPointer();
+    TemplateArg.NumExpansions = 0;
   }
-  
+
+  /// \brief Construct a template argument that is a template pack expansion.
+  ///
+  /// This form of template argument is generally used for template template
+  /// parameters. However, the template name could be a dependent template
+  /// name that ends up being instantiated to a function template whose address
+  /// is taken.
+  ///
+  /// \param Name The template name.
+  ///
+  /// \param NumExpansions The number of expansions that will be generated by
+  /// instantiating
+  TemplateArgument(TemplateName Name, llvm::Optional<unsigned> NumExpansions)
+    : Kind(TemplateExpansion) 
+  {
+    TemplateArg.Name = Name.getAsVoidPointer();
+    if (NumExpansions)
+      TemplateArg.NumExpansions = *NumExpansions + 1;
+    else
+      TemplateArg.NumExpansions = 0;
+  }
+
   /// \brief Construct a template argument that is an expression.
   ///
   /// This form of template argument only occurs in template argument
@@ -151,6 +176,9 @@ public:
     } else if (Kind == Pack) {
       Args.NumArgs = Other.Args.NumArgs;
       Args.Args = Other.Args.Args;
+    } else if (Kind == Template || Kind == TemplateExpansion) {
+      TemplateArg.Name = Other.TemplateArg.Name;
+      TemplateArg.NumExpansions = Other.TemplateArg.NumExpansions;
     } else
       TypeOrValue = Other.TypeOrValue;
   }
@@ -177,6 +205,9 @@ public:
     } else if (Other.Kind == Pack) {
       Args.NumArgs = Other.Args.NumArgs;
       Args.Args = Other.Args.Args;
+    } else if (Kind == Template || Kind == TemplateExpansion) {
+      TemplateArg.Name = Other.TemplateArg.Name;
+      TemplateArg.NumExpansions = Other.TemplateArg.NumExpansions;
     } else {
       TypeOrValue = Other.TypeOrValue;
     }
@@ -234,8 +265,7 @@ public:
     if (Kind != Template)
       return TemplateName();
     
-    return TemplateName::getFromVoidPointer(
-                                          reinterpret_cast<void*>(TypeOrValue));
+    return TemplateName::getFromVoidPointer(TemplateArg.Name);
   }
 
   /// \brief Retrieve the template argument as a template name; if the argument
@@ -244,10 +274,13 @@ public:
     if (Kind != Template && Kind != TemplateExpansion)
       return TemplateName();
     
-    return TemplateName::getFromVoidPointer(
-                                          reinterpret_cast<void*>(TypeOrValue));
+    return TemplateName::getFromVoidPointer(TemplateArg.Name);
   }
 
+  /// \brief Retrieve the number of expansions that a template template argument
+  /// expansion will produce, if known.
+  llvm::Optional<unsigned> getNumTemplateExpansions() const;
+  
   /// \brief Retrieve the template argument as an integral value.
   llvm::APSInt *getAsIntegral() {
     if (Kind != Integral)