--- a/hotspot/src/share/vm/runtime/javaCalls.hpp	Tue Jul 16 07:33:29 2013 +0200
+++ b/hotspot/src/share/vm/runtime/javaCalls.hpp	Wed Jun 12 11:17:39 2013 +0200
@@ -80,6 +80,8 @@
   oop              receiver()               { return _receiver; }
   void             oops_do(OopClosure* f);
 
+  bool             is_first_frame() const   { return _anchor.last_Java_sp() == NULL; }
+
 };