Calling a generator function returns a generator object

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 4071 matching lines @@
 
 MaybeObject* Heap::AllocateInitialMap(JSFunction* fun) {
   ASSERT(!fun->has_initial_map());
 
   // First create a new map with the size and number of in-object properties
   // suggested by the function.
   InstanceType instance_type;
   int instance_size;
   int in_object_properties;
   if (fun->shared()->is_generator()) {
-    // TODO(wingo): Replace with JS_GENERATOR_OBJECT_TYPE.
-    instance_type = JS_OBJECT_TYPE;
-    instance_size = JSObject::kHeaderSize;
+    instance_type = JS_GENERATOR_OBJECT_TYPE;
+    instance_size = JSGeneratorObject::kSize;
     in_object_properties = 0;
   } else {
     instance_type = JS_OBJECT_TYPE;
     instance_size = fun->shared()->CalculateInstanceSize();
     in_object_properties = fun->shared()->CalculateInObjectProperties();
   }
   Map* map;
   MaybeObject* maybe_map = AllocateMap(instance_type, instance_size);
   if (!maybe_map->To(&map)) return maybe_map;
 
@@ skipping 3728 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