Populate PrototypeInfo with prototype_object value

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 28a7ce623bfb35d8eae2c880c01ed033858e05a5..931ef0a0a9896ff80c2df17410d9ea471ad9c233 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9905,7 +9905,8 @@ void JSObject::OptimizeAsPrototype(Handle<JSObject> object,
     JSObject::NormalizeProperties(object, KEEP_INOBJECT_PROPERTIES, 0,
                                   "NormalizeAsPrototype");
   }
-  Handle<Map> previous_map(object->map());
+  Isolate* isolate = object->GetIsolate();
+  Handle<Map> previous_map(object->map(), isolate);
   if (!object->HasFastProperties()) {
     JSObject::MigrateSlowToFast(object, 0, "OptimizeAsPrototype");
   }
@@ -9921,8 +9922,7 @@ void JSObject::OptimizeAsPrototype(Handle<JSObject> object,
       // from the same context if undetectable from JS. This is to avoid keeping
       // memory alive unnecessarily.
       if (!constructor->shared()->IsApiFunction() &&
-          object->class_name() ==
-              object->GetIsolate()->heap()->Object_string()) {
+          object->class_name() == isolate->heap()->Object_string()) {
         Context* context = constructor->context()->native_context();
         JSFunction* object_function = context->object_function();
         object->map()->SetConstructor(object_function);
@@ -9930,6 +9930,8 @@ void JSObject::OptimizeAsPrototype(Handle<JSObject> object,
     }
     object->map()->set_is_prototype_map(true);
   }
+  Handle<Map> new_map(object->map(), isolate);
+  Map::SetPrototypeObject(new_map, object, isolate);
 }
 
 
@@ -9948,14 +9950,10 @@ void JSObject::RegisterPrototypeUser(Handle<JSObject> prototype,
   if (prototype->IsJSGlobalProxy()) {
     prototype = handle(JSObject::cast(prototype->map()->prototype()), isolate);
   }
-  Handle<PrototypeInfo> proto_info;
-  Object* maybe_proto_info = prototype->map()->prototype_info();
-  if (maybe_proto_info->IsPrototypeInfo()) {
-    proto_info = handle(PrototypeInfo::cast(maybe_proto_info), isolate);
-  } else {
-    proto_info = isolate->factory()->NewPrototypeInfo(prototype);
-    prototype->map()->set_prototype_info(*proto_info);
-  }
+  Handle<Map> proto_map(prototype->map(), isolate);
+  Handle<PrototypeInfo> proto_info =
+      Map::GetOrCreatePrototypeInfo(proto_map, isolate);
+  proto_info->set_prototype_object(*prototype);
   Handle<Object> maybe_registry(proto_info->prototype_users(), isolate);
   Handle<WeakFixedArray> new_array = WeakFixedArray::Add(maybe_registry, user);
   if (!maybe_registry.is_identical_to(new_array)) {
@@ -9983,6 +9981,45 @@ void JSObject::UnregisterPrototypeUser(Handle<JSObject> prototype,
 
 
 // static
+Handle<PrototypeInfo> Map::GetOrCreatePrototypeInfo(Handle<Map> map,
+                                                    Isolate* isolate) {
+  Object* maybe_proto_info = map->prototype_info();
+  if (maybe_proto_info->IsPrototypeInfo()) {
+    return handle(PrototypeInfo::cast(maybe_proto_info), isolate);
+  }
+  Handle<PrototypeInfo> proto_info = isolate->factory()->NewPrototypeInfo();
+  map->set_prototype_info(*proto_info);
+  return proto_info;
+}
+
+
+// static
+void Map::SetPrototypeObject(Handle<Map> map, Handle<JSObject> prototype_obj,
+                             Isolate* isolate) {
+  if (!FLAG_track_prototype_users) return;
+  Handle<PrototypeInfo> proto_info = GetOrCreatePrototypeInfo(map, isolate);
+  proto_info->set_prototype_object(*prototype_obj);
+}
+
+
+Object* Map::GetPrototypeObject() {
+  DisallowHeapAllocation no_handlification_required;
+  if (!is_prototype_map()) return Smi::FromInt(0);
+  Object* maybe_prototype_info = prototype_info();
+  if (!maybe_prototype_info->IsPrototypeInfo()) return Smi::FromInt(0);
+  PrototypeInfo* proto_info = PrototypeInfo::cast(maybe_prototype_info);
+  Object* maybe_obj = proto_info->prototype_object();
+  if (maybe_obj->IsSmi()) return maybe_obj;
+  JSObject* object = JSObject::cast(maybe_obj);
+  if (object->map() != this) {
+    proto_info->set_prototype_object(Smi::FromInt(0));
+    return Smi::FromInt(0);
+  }
+  return object;
+}
+
+
+// static
 void Map::SetPrototype(Handle<Map> map, Handle<Object> prototype,
                        PrototypeOptimizationMode proto_mode) {
   if (map->prototype()->IsJSObject() && FLAG_track_prototype_users) {