--- a/hotspot/src/share/vm/utilities/vmError.cpp	Fri Feb 17 15:11:32 2012 -0800
+++ b/hotspot/src/share/vm/utilities/vmError.cpp	Thu Feb 23 14:58:35 2012 +0100
@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "compiler/compileBroker.hpp"
 #include "gc_interface/collectedHeap.hpp"
+#include "prims/whitebox.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/frame.inline.hpp"
 #include "runtime/init.hpp"
@@ -717,6 +718,13 @@
        st->cr();
      }
 
+  STEP(215, "(printing warning if internal testing API used)" )
+
+     if (WhiteBox::used()) {
+       st->print_cr("Unsupported internal testing APIs have been used.");
+       st->cr();
+     }
+
   STEP(220, "(printing environment variables)" )
 
      if (_verbose) {