Set LastAdded to kNoneAdded in RawCopy.

src/heap.cc

 // Copyright 2012 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 4107 matching lines @@
   // global objects. They will be unused once we normalize the object.
   ASSERT(map->unused_property_fields() == 0);
   ASSERT(map->inobject_properties() == 0);
 
   // Initial size of the backing store to avoid resize of the storage during
   // bootstrapping. The size differs between the JS global object ad the
   // builtins object.
   int initial_size = map->instance_type() == JS_GLOBAL_OBJECT_TYPE ? 64 : 512;
 
   // Allocate a dictionary object for backing storage.
-  Object* obj;
-  { MaybeObject* maybe_obj =
-        StringDictionary::Allocate(
-            map->NumberOfDescribedProperties() * 2 + initial_size);
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
-  StringDictionary* dictionary = StringDictionary::cast(obj);
+  StringDictionary* dictionary;
+  MaybeObject* maybe_dictionary =
+      StringDictionary::Allocate(
+          map->NumberOfDescribedProperties() * 2 + initial_size);
+  if (!maybe_dictionary->To(&dictionary)) return maybe_dictionary;
 
   // The global object might be created from an object template with accessors.
   // Fill these accessors into the dictionary.
   DescriptorArray* descs = map->instance_descriptors();
   for (int i = 0; i < descs->number_of_descriptors(); i++) {
     PropertyDetails details = descs->GetDetails(i);
     ASSERT(details.type() == CALLBACKS);  // Only accessors are expected.
     PropertyDetails d =
         PropertyDetails(details.attributes(), CALLBACKS, details.index());
     Object* value = descs->GetCallbacksObject(i);
-    { MaybeObject* maybe_value = AllocateJSGlobalPropertyCell(value);
-      if (!maybe_value->ToObject(&value)) return maybe_value;
-    }
+    MaybeObject* maybe_value = AllocateJSGlobalPropertyCell(value);
+    if (!maybe_value->ToObject(&value)) return maybe_value;
 
-    Object* result;
-    { MaybeObject* maybe_result = dictionary->Add(descs->GetKey(i), value, d);
-      if (!maybe_result->ToObject(&result)) return maybe_result;
-    }
-    dictionary = StringDictionary::cast(result);
+    MaybeObject* maybe_added = dictionary->Add(descs->GetKey(i), value, d);
+    if (!maybe_added->To(&dictionary)) return maybe_added;
   }
 
   // Allocate the global object and initialize it with the backing store.
-  { MaybeObject* maybe_obj = Allocate(map, OLD_POINTER_SPACE);
-    if (!maybe_obj->ToObject(&obj)) return maybe_obj;
-  }
-  JSObject* global = JSObject::cast(obj);
+  JSObject* global;
+  MaybeObject* maybe_global = Allocate(map, OLD_POINTER_SPACE);
+  if (!maybe_global->To(&global)) return maybe_global;
+
   InitializeJSObjectFromMap(global, dictionary, map);
 
   // Create a new map for the global object.
   Map* new_map;
-  { MaybeObject* maybe_map = map->CopyDropDescriptors();
-    if (!maybe_map->To(&new_map)) return maybe_map;
-  }
+  MaybeObject* maybe_map = map->CopyDropDescriptors();
+  if (!maybe_map->To(&new_map)) return maybe_map;
+
+  ASSERT(new_map->LastAdded() == Map::kNoneAdded);
 
   // Set up the global object as a normalized object.
   global->set_map(new_map);
   global->set_properties(dictionary);
 
   // Make sure result is a global object with properties in dictionary.
   ASSERT(global->IsGlobalObject());
   ASSERT(!global->HasFastProperties());
   return global;
 }
@@ skipping 3058 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   FIXED_ARRAY_SUB_INSTANCE_TYPE_LIST(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   memcpy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   memcpy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal