Remove hidden prototype for builtin functions.

src/runtime.cc

 // Copyright 2011 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 865 matching lines @@
   Object* V = args[1];
   while (true) {
     Object* prototype = V->GetPrototype();
     if (prototype->IsNull()) return isolate->heap()->false_value();
     if (O == prototype) return isolate->heap()->true_value();
     V = prototype;
   }
 }
 
 
-// Inserts an object as the hidden prototype of another object.
-RUNTIME_FUNCTION(MaybeObject*, Runtime_SetHiddenPrototype) {
-  NoHandleAllocation ha;
-  ASSERT(args.length() == 2);
-  CONVERT_CHECKED(JSObject, jsobject, args[0]);
-  CONVERT_CHECKED(JSObject, proto, args[1]);
-
-  // Sanity checks.  The old prototype (that we are replacing) could
-  // theoretically be null, but if it is not null then check that we
-  // didn't already install a hidden prototype here.
-  RUNTIME_ASSERT(!jsobject->GetPrototype()->IsHeapObject() ||
-    !HeapObject::cast(jsobject->GetPrototype())->map()->is_hidden_prototype());
-  RUNTIME_ASSERT(!proto->map()->is_hidden_prototype());
-
-  // Allocate up front before we start altering state in case we get a GC.
-  Object* map_or_failure;
-  { MaybeObject* maybe_map_or_failure = proto->map()->CopyDropTransitions();
-    if (!maybe_map_or_failure->ToObject(&map_or_failure)) {
-      return maybe_map_or_failure;
-    }
-  }
-  Map* new_proto_map = Map::cast(map_or_failure);
-
-  { MaybeObject* maybe_map_or_failure = jsobject->map()->CopyDropTransitions();
-    if (!maybe_map_or_failure->ToObject(&map_or_failure)) {
-      return maybe_map_or_failure;
-    }
-  }
-  Map* new_map = Map::cast(map_or_failure);
-
-  // Set proto's prototype to be the old prototype of the object.
-  new_proto_map->set_prototype(jsobject->GetPrototype());
-  proto->set_map(new_proto_map);
-  new_proto_map->set_is_hidden_prototype();
-
-  // Set the object's prototype to proto.
-  new_map->set_prototype(proto);
-  jsobject->set_map(new_map);
-
-  return isolate->heap()->undefined_value();
-}
-
-
 RUNTIME_FUNCTION(MaybeObject*, Runtime_IsConstructCall) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 0);
   JavaScriptFrameIterator it(isolate);
   return isolate->heap()->ToBoolean(it.frame()->IsConstructor());
 }
 
 
 // Recursively traverses hidden prototypes if property is not found
 static void GetOwnPropertyImplementation(JSObject* obj,
@@ skipping 12632 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags);
   }
 }
 
 
 } }  // namespace v8::internal