Move Object.assign implementation to C++

src/js/v8natives.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
@@ skipping 786 matching lines @@
   return obj;
 }
 
 
 // ES6 section 19.1.2.6
 function ObjectGetOwnPropertyDescriptor(obj, p) {
   return %GetOwnProperty(obj, p);
 }
 
 
-// ES6 section 9.1.12 / 9.5.12
-function OwnPropertyKeys(obj) {
-  return %GetOwnPropertyKeys(obj, PROPERTY_FILTER_NONE);
-}
-
-
 // ES5 section 15.2.3.4.
 function ObjectGetOwnPropertyNames(obj) {
   obj = TO_OBJECT(obj);
   return %GetOwnPropertyKeys(obj, PROPERTY_FILTER_SKIP_SYMBOLS);
 }
 
 
 // ES5 section 15.2.3.5.
 function ObjectCreate(proto, properties) {
   if (!IS_SPEC_OBJECT(proto) && proto !== null) {
@@ skipping 86 matching lines @@
 }
 
 
 // ES6 19.1.2.11
 function ObjectIsExtensible(obj) {
   if (!IS_SPEC_OBJECT(obj)) return false;
   return %IsExtensible(obj);
 }
 
 
-// ES6 19.1.2.1
-function ObjectAssign(target, sources) {
-  // TODO(bmeurer): Move this to toplevel.
-  "use strict";
-  var to = TO_OBJECT(target);
-  var argsLen = %_ArgumentsLength();
-  if (argsLen < 2) return to;
-
-  for (var i = 1; i < argsLen; ++i) {
-    var nextSource = %_Arguments(i);
-    if (IS_NULL_OR_UNDEFINED(nextSource)) {
-      continue;
-    }
-
-    var from = TO_OBJECT(nextSource);
-    var keys = OwnPropertyKeys(from);
-    var len = keys.length;
-
-    for (var j = 0; j < len; ++j) {
-      var key = keys[j];
-      if (%PropertyIsEnumerable(from, key)) {
-        var propValue = from[key];
-        to[key] = propValue;
-      }
-    }
-  }
-  return to;
-}
-
-
 // ES6 B.2.2.1.1
 function ObjectGetProto() {
   return %_GetPrototype(TO_OBJECT(this));
 }
 
 
 // ES6 B.2.2.1.2
 function ObjectSetProto(proto) {
   CHECK_OBJECT_COERCIBLE(this, "Object.prototype.__proto__");
 
@@ skipping 33 matching lines @@
   "__defineGetter__", ObjectDefineGetter,
   "__lookupGetter__", ObjectLookupGetter,
   "__defineSetter__", ObjectDefineSetter,
   "__lookupSetter__", ObjectLookupSetter
 ]);
 utils.InstallGetterSetter(GlobalObject.prototype, "__proto__", ObjectGetProto,
                     ObjectSetProto);
 
 // Set up non-enumerable functions in the Object object.
 utils.InstallFunctions(GlobalObject, DONT_ENUM, [
-  "assign", ObjectAssign,
+  // assign is added in bootstrapper.cc.
   "keys", ObjectKeys,
   "create", ObjectCreate,
   "defineProperty", ObjectDefineProperty,
   "defineProperties", ObjectDefineProperties,
   "freeze", ObjectFreezeJS,
   "getPrototypeOf", ObjectGetPrototypeOf,
   "setPrototypeOf", ObjectSetPrototypeOf,
   "getOwnPropertyDescriptor", ObjectGetOwnPropertyDescriptor,
   "getOwnPropertyNames", ObjectGetOwnPropertyNames,
   // getOwnPropertySymbols is added in symbol.js.
@@ skipping 477 matching lines @@
   to.ObjectIsSealed = ObjectIsSealed;
   to.ObjectKeys = ObjectKeys;
 });
 
 %InstallToContext([
   "global_eval_fun", GlobalEval,
   "object_value_of", ObjectValueOf,
 ]);
 
 })