diff --git a/js/src/jsdbgapi.cpp b/js/src/jsdbgapi.cpp
index e27c20c675d..15ff0cf9210 100644
--- a/js/src/jsdbgapi.cpp
+++ b/js/src/jsdbgapi.cpp
@@ -73,16 +73,18 @@ JS_SetRuntimeDebugMode(JSRuntime *rt, JSBool debug)
 }
 
 JSTrapStatus
-js::ScriptDebugPrologue(JSContext *cx, StackFrame *fp)
+js::ScriptDebugPrologue(JSContext *cx, AbstractFramePtr frame)
 {
-    JS_ASSERT(fp == cx->fp());
+    JS_ASSERT_IF(frame.isStackFrame(), frame.asStackFrame() == cx->fp());
 
-    if (fp->isFramePushedByExecute()) {
+    if (frame.isFramePushedByExecute()) {
         if (JSInterpreterHook hook = cx->runtime->debugHooks.executeHook)
-            fp->setHookData(hook(cx, Jsvalify(fp), true, 0, cx->runtime->debugHooks.executeHookData));
+            frame.setHookData(hook(cx, Jsvalify(frame.asStackFrame()), true, 0,
+                                   cx->runtime->debugHooks.executeHookData));
     } else {
         if (JSInterpreterHook hook = cx->runtime->debugHooks.callHook)
-            fp->setHookData(hook(cx, Jsvalify(fp), true, 0, cx->runtime->debugHooks.callHookData));
+            frame.setHookData(hook(cx, Jsvalify(frame.asStackFrame()), true, 0,
+                                   cx->runtime->debugHooks.callHookData));
     }
 
     Value rval;
@@ -97,7 +99,7 @@ js::ScriptDebugPrologue(JSContext *cx, StackFrame *fp)
         cx->clearPendingException();
         break;
       case JSTRAP_RETURN:
-        fp->setReturnValue(rval);
+        frame.setReturnValue(rval);
         break;
       default:
         JS_NOT_REACHED("bad Debugger::onEnterFrame JSTrapStatus value");
@@ -106,18 +108,18 @@ js::ScriptDebugPrologue(JSContext *cx, StackFrame *fp)
 }
 
 bool
-js::ScriptDebugEpilogue(JSContext *cx, StackFrame *fp, bool okArg)
+js::ScriptDebugEpilogue(JSContext *cx, AbstractFramePtr frame, bool okArg)
 {
-    JS_ASSERT(fp == cx->fp());
+    JS_ASSERT_IF(frame.isStackFrame(), frame.asStackFrame() == cx->fp());
     JSBool ok = okArg;
 
-    if (void *hookData = fp->maybeHookData()) {
-        if (fp->isFramePushedByExecute()) {
+    if (void *hookData = frame.maybeHookData()) {
+        if (frame.isFramePushedByExecute()) {
             if (JSInterpreterHook hook = cx->runtime->debugHooks.executeHook)
-                hook(cx, Jsvalify(fp), false, &ok, hookData);
+                hook(cx, Jsvalify(frame.asStackFrame()), false, &ok, hookData);
         } else {
             if (JSInterpreterHook hook = cx->runtime->debugHooks.callHook)
-                hook(cx, Jsvalify(fp), false, &ok, hookData);
+                hook(cx, Jsvalify(frame.asStackFrame()), false, &ok, hookData);
         }
     }
 
diff --git a/js/src/jsinterp.h b/js/src/jsinterp.h
index a0c9f58d964..2123b0992f3 100644
--- a/js/src/jsinterp.h
+++ b/js/src/jsinterp.h
@@ -22,7 +22,7 @@ namespace js {
 
 /*
  * Announce to the debugger that the thread has entered a new JavaScript frame,
- * |fp|. Call whatever hooks have been registered to observe new frames, and
+ * |frame|. Call whatever hooks have been registered to observe new frames, and
  * return a JSTrapStatus code indication how execution should proceed:
  *
  * - JSTRAP_CONTINUE: Continue execution normally.
@@ -35,18 +35,18 @@ namespace js {
  *   exception.
  *
  * - JSTRAP_RETURN: Return from the new frame immediately. ScriptDebugPrologue
- *   has set |cx->fp()|'s return value appropriately.
+ *   has set |frame|'s return value appropriately.
  */
 extern JSTrapStatus
-ScriptDebugPrologue(JSContext *cx, StackFrame *fp);
+ScriptDebugPrologue(JSContext *cx, AbstractFramePtr frame);
 
 /*
- * Announce to the debugger that the thread has exited a JavaScript frame, |fp|.
+ * Announce to the debugger that the thread has exited a JavaScript frame, |frame|.
  * If |ok| is true, the frame is returning normally; if |ok| is false, the frame
  * is throwing an exception or terminating.
  *
  * Call whatever hooks have been registered to observe frame exits. Change cx's
- * current exception and |fp|'s return value to reflect the changes in behavior
+ * current exception and |frame|'s return value to reflect the changes in behavior
  * the hooks request, if any. Return the new error/success value.
  *
  * This function may be called twice for the same outgoing frame; only the
@@ -56,7 +56,7 @@ ScriptDebugPrologue(JSContext *cx, StackFrame *fp);
  * alternative path, containing its own call to ScriptDebugEpilogue.)
  */
 extern bool
-ScriptDebugEpilogue(JSContext *cx, StackFrame *fp, bool ok);
+ScriptDebugEpilogue(JSContext *cx, AbstractFramePtr frame, bool ok);
 
 /*
  * For a given |call|, convert null/undefined |this| into the global object for
diff --git a/js/src/vm/Stack-inl.h b/js/src/vm/Stack-inl.h
index 2ca994750dc..b934ff65cda 100644
--- a/js/src/vm/Stack-inl.h
+++ b/js/src/vm/Stack-inl.h
@@ -609,6 +609,35 @@ StackIter::ionForEachCanonicalActualArg(Op op)
 #endif
 }
 
+inline void *
+AbstractFramePtr::maybeHookData() const
+{
+    if (isStackFrame())
+        return asStackFrame()->maybeHookData();
+    JS_NOT_REACHED("Invalid frame");
+    return NULL;
+}
+
+inline void
+AbstractFramePtr::setHookData(void *data) const
+{
+    if (isStackFrame()) {
+        asStackFrame()->setHookData(data);
+        return;
+    }
+    JS_NOT_REACHED("Invalid frame");
+}
+
+inline void
+AbstractFramePtr::setReturnValue(const Value &rval) const
+{
+    if (isStackFrame()) {
+        asStackFrame()->setReturnValue(rval);
+        return;
+    }
+    JS_NOT_REACHED("Invalid frame");
+}
+
 inline UnrootedObject
 AbstractFramePtr::scopeChain() const
 {
diff --git a/js/src/vm/Stack.h b/js/src/vm/Stack.h
index 6a8d8db1f94..5b09473d388 100644
--- a/js/src/vm/Stack.h
+++ b/js/src/vm/Stack.h
@@ -1790,6 +1790,9 @@ class AbstractFramePtr
         JS_NOT_REACHED("Invalid frame");
         return false;
     }
+    bool isFramePushedByExecute() const {
+        return isGlobalFrame() || isEvalFrame();
+    }
     bool isDebuggerFrame() const {
         if (isStackFrame())
             return asStackFrame()->isDebuggerFrame();
@@ -1898,6 +1901,10 @@ class AbstractFramePtr
         JS_NOT_REACHED("Invalid frame");
         return AbstractFramePtr();
     }
+
+    inline void *maybeHookData() const;
+    inline void setHookData(void *data) const;
+    inline void setReturnValue(const Value &rval) const;
 };
 
 template <>