Introduce DisallowDeoptimization scope.

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 2763 matching lines @@
       proto_map = Handle<Map>(holder->map());
     }
   }
   return CurrentMapForDeprecatedInternal(map);
 }
 
 
 // static
 MaybeHandle<Map> Map::CurrentMapForDeprecatedInternal(Handle<Map> old_map) {
   DisallowHeapAllocation no_allocation;
+  DisallowDeoptimization no_deoptimization(old_map->GetIsolate());
 
   if (!old_map->is_deprecated()) return old_map;
 
   // Check the state of the root map.
   Map* root_map = old_map->FindRootMap();
   if (!old_map->EquivalentToForTransition(root_map)) return MaybeHandle<Map>();
   int root_nof = root_map->NumberOfOwnDescriptors();
 
   int old_nof = old_map->NumberOfOwnDescriptors();
   DescriptorArray* old_descriptors = old_map->instance_descriptors();
@@ skipping 1139 matching lines @@
       ALLOW_AS_CONSTANT);
   object->map()->set_migration_target(true);
   if (FLAG_trace_migration) {
     object->PrintInstanceMigration(stdout, *original_map, object->map());
   }
 }
 
 
 // static
 bool JSObject::TryMigrateInstance(Handle<JSObject> object) {
-  Handle<Map> original_map(object->map());
+  Isolate* isolate = object->GetIsolate();
+  DisallowDeoptimization no_deoptimization(isolate);
+  Handle<Map> original_map(object->map(), isolate);
   Handle<Map> new_map;
   if (!Map::CurrentMapForDeprecatedInternal(original_map).ToHandle(&new_map)) {
     return false;
   }
   JSObject::MigrateToMap(object, new_map);
   if (FLAG_trace_migration) {
     object->PrintInstanceMigration(stdout, *original_map, object->map());
   }
   return true;
 }
@@ skipping 13385 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