Eagerly parse expected transitions in JSON.

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 2584 matching lines @@
   if (IsFastElementsKind(to_kind)) {
     allow_store_transition &=
         IsTransitionableFastElementsKind(from_kind) &&
         IsMoreGeneralElementsKindTransition(from_kind, to_kind);
   }
 
   if (!allow_store_transition) {
     return start_map->CopyAsElementsKind(to_kind, OMIT_TRANSITION);
   }
 
-  Map* closest_map = FindClosestElementsTransition(start_map, to_kind);
+  return start_map->AsElementsKind(to_kind);
+}
 
-  if (closest_map->elements_kind() == to_kind) {
+
+MaybeObject* Map::AsElementsKind(ElementsKind kind) {
+  Map* closest_map = FindClosestElementsTransition(this, kind);
+
+  if (closest_map->elements_kind() == kind) {
     return closest_map;
   }
 
-  return AddMissingElementsTransitions(closest_map, to_kind);
+  return AddMissingElementsTransitions(closest_map, kind);
 }
 
 
 void JSObject::LocalLookupRealNamedProperty(Name* name, LookupResult* result) {
   if (IsJSGlobalProxy()) {
     Object* proto = GetPrototype();
     if (proto->IsNull()) return result->NotFound();
     ASSERT(proto->IsJSGlobalObject());
     // A GlobalProxy's prototype should always be a proper JSObject.
     return JSObject::cast(proto)->LocalLookupRealNamedProperty(name, result);
@@ skipping 444 matching lines @@
 
 
 void JSObject::AddFastPropertyUsingMap(Handle<JSObject> object,
                                        Handle<Map> map) {
   CALL_HEAP_FUNCTION_VOID(
       object->GetIsolate(),
       object->AddFastPropertyUsingMap(*map));
 }
 
 
+void JSObject::TransitionToMap(Handle<JSObject> object, Handle<Map> map) {
+  CALL_HEAP_FUNCTION_VOID(
+      object->GetIsolate(),
+      object->TransitionToMap(*map));
+}
+
+
 MaybeObject* JSObject::SetPropertyForResult(LookupResult* lookup,
                                             Name* name_raw,
                                             Object* value_raw,
                                             PropertyAttributes attributes,
                                             StrictModeFlag strict_mode,
                                             StoreFromKeyed store_mode) {
   Heap* heap = GetHeap();
   Isolate* isolate = heap->isolate();
   // Make sure that the top context does not change when doing callbacks or
   // interceptor calls.
@@ skipping 11379 matching lines @@
   set_year(Smi::FromInt(year), SKIP_WRITE_BARRIER);
   set_month(Smi::FromInt(month), SKIP_WRITE_BARRIER);
   set_day(Smi::FromInt(day), SKIP_WRITE_BARRIER);
   set_weekday(Smi::FromInt(weekday), SKIP_WRITE_BARRIER);
   set_hour(Smi::FromInt(hour), SKIP_WRITE_BARRIER);
   set_min(Smi::FromInt(min), SKIP_WRITE_BARRIER);
   set_sec(Smi::FromInt(sec), SKIP_WRITE_BARRIER);
 }
 
 } }  // namespace v8::internal