Rewrite Object.prototype.toString in 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
 
-var FLAG_harmony_tostring;
 var GlobalArray = global.Array;
 var GlobalBoolean = global.Boolean;
 var GlobalFunction = global.Function;
 var GlobalNumber = global.Number;
 var GlobalObject = global.Object;
 var InternalArray = utils.InternalArray;
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var MakeRangeError;
 var MakeSyntaxError;
 var MakeTypeError;
 var MathAbs;
 var NaN = %GetRootNaN();
+var ObjectToString = utils.ImportNow("object_to_string");
 var ObserveBeginPerformSplice;
 var ObserveEndPerformSplice;
 var ObserveEnqueueSpliceRecord;
 var SameValue = utils.ImportNow("SameValue");
 var StringIndexOf;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 
 utils.Import(function(from) {
   MakeRangeError = from.MakeRangeError;
   MakeSyntaxError = from.MakeSyntaxError;
   MakeTypeError = from.MakeTypeError;
   MathAbs = from.MathAbs;
   ObserveBeginPerformSplice = from.ObserveBeginPerformSplice;
   ObserveEndPerformSplice = from.ObserveEndPerformSplice;
   ObserveEnqueueSpliceRecord = from.ObserveEnqueueSpliceRecord;
   StringIndexOf = from.StringIndexOf;
 });
 
-utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tostring = from.FLAG_harmony_tostring;
-});
-
 // ----------------------------------------------------------------------------
 
 
 // ES6 18.2.3 isNaN(number)
 function GlobalIsNaN(number) {
   number = TO_NUMBER(number);
   return NUMBER_IS_NAN(number);
 }
 
 
@@ skipping 80 matching lines @@
   "isFinite", GlobalIsFinite,
   "parseInt", GlobalParseInt,
   "parseFloat", GlobalParseFloat,
   "eval", GlobalEval
 ]);
 
 
 // ----------------------------------------------------------------------------
 // Object
 
-// ES6 19.1.3.6 Object.prototype.toString()
-function ObjectToString() {
-  if (IS_UNDEFINED(this)) return "[object Undefined]";
-  if (IS_NULL(this)) return "[object Null]";
-  var O = TO_OBJECT(this);
-  var builtinTag = %_ClassOf(O);
-  var tag;
-
-  // TODO(caitp): cannot wait to get rid of this flag :>
-  if (FLAG_harmony_tostring) {
-    tag = O[toStringTagSymbol];
-    if (!IS_STRING(tag)) {
-      tag = builtinTag;
-    }
-  } else {
-    tag = builtinTag;
-  }
-
-  return `[object ${tag}]`;
-}
-
-
 // ES6 19.1.3.5 Object.prototype.toLocaleString([reserved1 [,reserved2]])
 function ObjectToLocaleString() {
   CHECK_OBJECT_COERCIBLE(this, "Object.prototype.toLocaleString");
   return this.toString();
 }
 
 
 // ES6 19.1.3.7 Object.prototype.valueOf()
 function ObjectValueOf() {
   return TO_OBJECT(this);
@@ skipping 1329 matching lines @@
   to.IsNaN = GlobalIsNaN;
   to.NewFunctionString = NewFunctionString;
   to.NumberIsNaN = NumberIsNaN;
   to.ObjectDefineProperties = ObjectDefineProperties;
   to.ObjectDefineProperty = ObjectDefineProperty;
   to.ObjectFreeze = ObjectFreezeJS;
   to.ObjectHasOwnProperty = ObjectHasOwnProperty;
   to.ObjectIsFrozen = ObjectIsFrozen;
   to.ObjectIsSealed = ObjectIsSealed;
   to.ObjectKeys = ObjectKeys;
-  to.ObjectToString = ObjectToString;
 });
 
 %InstallToContext([
   "global_eval_fun", GlobalEval,
   "object_value_of", ObjectValueOf,
-  "object_to_string", ObjectToString,
 ]);
 
 })