Better handling of stepping out of a function...

src/debug.cc

Index: src/debug.cc
===================================================================
--- src/debug.cc	(revision 4834)
+++ src/debug.cc	(working copy)
@@ -1713,6 +1713,40 @@
 }
 
 
+bool Debug::IsBreakAtReturn(JavaScriptFrame* frame) {
+  HandleScope scope;
+
+  // Get the executing function in which the debug break occurred.
+  Handle<SharedFunctionInfo> shared =
+      Handle<SharedFunctionInfo>(JSFunction::cast(frame->function())->shared());
+  if (!EnsureDebugInfo(shared)) {
+    // Return if we failed to retrieve the debug info.
+    return false;
+  }
+  Handle<DebugInfo> debug_info = GetDebugInfo(shared);
+  Handle<Code> code(debug_info->code());
+#ifdef DEBUG
+  // Get the code which is actually executing.
+  Handle<Code> frame_code(frame->code());
+  ASSERT(frame_code.is_identical_to(code));
+#endif
+
+  // Find the call address in the running code.
+  Address addr = frame->pc() - Assembler::kCallTargetAddressOffset;
+
+  // Check if the location is at JS return.
+  RelocIterator it(debug_info->code());
+  while (!it.done()) {
+    if (RelocInfo::IsJSReturn(it.rinfo()->rmode())) {
+      return (it.rinfo()->pc() ==
+          addr - Assembler::kPatchReturnSequenceAddressOffset);
+    }
+    it.next();
+  }
+  return false;
+}
+
+
 void Debug::FramesHaveBeenDropped(StackFrame::Id new_break_frame_id) {
   thread_local_.frames_are_dropped_ = true;
   thread_local_.break_frame_id_ = new_break_frame_id;