1 files changed, 1 insertions, 3 deletions
diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index d15f91a745..5eb0d55a39 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -3988,9 +3988,7 @@ QualType TreeTransform<Derived>::
 template<typename Derived>
 QualType TreeTransform<Derived>::TransformPackExpansionType(TypeLocBuilder &TLB,
                                                       PackExpansionTypeLoc TL) {
-  // FIXME: Implement!
-  getSema().Diag(TL.getEllipsisLoc(), 
-                 diag::err_pack_expansion_instantiation_unsupported);
+  llvm_unreachable("Caller must expansion pack expansion types");
   return QualType();
 }