Fix a failure to correctly set the static type on a frame element at a...

src/virtual-frame.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 289 matching lines @@
   }
 
   // Forget the frame elements that will be popped by the call.
   Forget(dropped_args);
 }
 
 
 void VirtualFrame::PrepareForReturn() {
   // Spill all locals. This is necessary to make sure all locals have
   // the right value when breaking at the return site in the debugger.
-  //
-  // TODO(203): It is also necessary to ensure that merging at the
-  // return site does not generate code to overwrite eax, where the
-  // return value is kept in a non-refcounted register reference.
-  for (int i = 0; i < expression_base_index(); i++) SpillElementAt(i);
+  // Set their static type to unknown so that they will match the known
+  // return frame.
+  for (int i = 0; i < expression_base_index(); i++) {
+    SpillElementAt(i);
+    elements_[i].set_static_type(StaticType::unknown());
+  }
 }
 
 
 void VirtualFrame::SetElementAt(int index, Result* value) {
   int frame_index = elements_.length() - index - 1;
   ASSERT(frame_index >= 0);
   ASSERT(frame_index < elements_.length());
   ASSERT(value->is_valid());
   FrameElement original = elements_[frame_index];
 
@@ skipping 145 matching lines @@
 // Specialization of List::ResizeAdd to non-inlined version for FrameElements.
 // The function ResizeAdd becomes a real function, whose implementation is the
 // inlined ResizeAddInternal.
 template <>
 void List<FrameElement,
           FreeStoreAllocationPolicy>::ResizeAdd(const FrameElement& element) {
   ResizeAddInternal(element);
 }
 
 } }  // namespace v8::internal