--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/amd64/AMD64ThreadContext.java	Fri Aug 17 16:47:04 2012 -0700
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/debugger/amd64/AMD64ThreadContext.java	Thu Aug 30 11:20:01 2012 -0400
@@ -25,6 +25,7 @@
 package sun.jvm.hotspot.debugger.amd64;
 
 import sun.jvm.hotspot.debugger.*;
+import sun.jvm.hotspot.debugger.cdbg.*;
 
 /** Specifies the thread context on amd64 platforms; only a sub-portion
  * of the context is guaranteed to be present on all operating
@@ -98,6 +99,10 @@
         return data[index];
     }
 
+    public CFrame getTopFrame(Debugger dbg) {
+        return null;
+    }
+
     /** This can't be implemented in this class since we would have to
      * tie the implementation to, for example, the debugging system */
     public abstract void setRegisterAsAddress(int index, Address value);