Introduce a new type, PackExpansionType, to capture types that are

pack expansions, e.g. given

  template<typename... Types> struct tuple;

  template<typename... Types>
  struct tuple_of_refs {
    typedef tuple<Types&...> types;
  };

the type of the "types" typedef is a PackExpansionType whose pattern
is Types&. 

This commit introduces support for creating pack expansions for
template type arguments, as above, but not for any other kind of pack
expansion, nor for any form of instantiation.

llvm-svn: 122223

1 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index cc485c47d9f..7ff217e3345 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -707,7 +707,14 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
     }
     break;
   }
-  
+
+  case Type::PackExpansion:
+    if (!IsStructurallyEquivalent(Context,
+                                  cast<PackExpansionType>(T1)->getPattern(),
+                                  cast<PackExpansionType>(T2)->getPattern()))
+      return false;
+    break;
+
   case Type::ObjCInterface: {
     const ObjCInterfaceType *Iface1 = cast<ObjCInterfaceType>(T1);
     const ObjCInterfaceType *Iface2 = cast<ObjCInterfaceType>(T2);