Make cells pointing to JSObjects weak in optimized code.

src/objects.cc

 // Copyright 2013 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 10326 matching lines @@
 }
 
 
 void Code::InvalidateRelocation() {
   set_relocation_info(GetHeap()->empty_byte_array());
 }
 
 
 void Code::InvalidateEmbeddedObjects() {
   Object* undefined = GetHeap()->undefined_value();
-  int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
+  Cell* undefined_cell = GetHeap()->undefined_cell();
+  int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT) |
+                  RelocInfo::ModeMask(RelocInfo::CELL);
   for (RelocIterator it(this, mode_mask); !it.done(); it.next()) {
     RelocInfo::Mode mode = it.rinfo()->rmode();
     if (mode == RelocInfo::EMBEDDED_OBJECT) {
       it.rinfo()->set_target_object(undefined, SKIP_WRITE_BARRIER);
+    } else if (mode == RelocInfo::CELL) {
+      it.rinfo()->set_target_cell(undefined_cell, SKIP_WRITE_BARRIER);
     }
   }
 }
 
 
 void Code::Relocate(intptr_t delta) {
   for (RelocIterator it(this, RelocInfo::kApplyMask); !it.done(); it.next()) {
     it.rinfo()->apply(delta);
   }
   CPU::FlushICache(instruction_start(), instruction_size());
@@ skipping 941 matching lines @@
 
 bool Code::IsWeakEmbeddedObject(Kind kind, Object* object) {
   if (kind != Code::OPTIMIZED_FUNCTION) return false;
 
   if (object->IsMap()) {
     return Map::cast(object)->CanTransition() &&
            FLAG_collect_maps &&
            FLAG_weak_embedded_maps_in_optimized_code;
   }
 
-  if (object->IsJSObject()) {
+  if (object->IsJSObject() ||
+      (object->IsCell() && Cell::cast(object)->value()->IsJSObject())) {
     return FLAG_weak_embedded_objects_in_optimized_code;
   }
 
   return false;
 }
 
 
 void JSObject::SetFastDoubleElementsCapacityAndLength(Handle<JSObject> object,
                                                       int capacity,
                                                       int length) {
@@ skipping 5351 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal