Parameter packs can't have default arguments.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73262 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 8058ad2d63..00d3e54565 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -187,6 +187,15 @@ void Sema::ActOnTypeParameterDefault(DeclPtrTy TypeParam,
     = cast<TemplateTypeParmDecl>(TypeParam.getAs<Decl>());
   QualType Default = QualType::getFromOpaquePtr(DefaultT);
 
+  // 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 (Parm->isParameterPack()) {
+    Diag(DefaultLoc, diag::err_template_param_pack_default_arg);
+    Parm->setInvalidDecl();
+    return;
+  }
+  
   // C++ [temp.param]p14:
   //   A template-parameter shall not be used in its own default argument.
   // FIXME: Implement this check! Needs a recursive walk over the types.