[es6] Bound function names

src/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.
 
 var $functionSourceString;
 var $globalEval;
 var $objectDefineOwnProperty;
 var $objectGetOwnPropertyDescriptor;
 var $toCompletePropertyDescriptor;
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
 
 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 SetFunctionName = utils.SetFunctionName;
 
 var MathAbs;
 var ProxyDelegateCallAndConstruct;
 var ProxyDerivedHasOwnTrap;
 var ProxyDerivedKeysTrap;
 var StringIndexOf;
 
 utils.Import(function(from) {
   MathAbs = from.MathAbs;
   StringIndexOf = from.StringIndexOf;
@@ skipping 1723 matching lines @@
     var argc = %_ArgumentsLength();
     if (argc > 0) argc--;  // Don't count the thisArg as parameter.
     new_length = old_length - argc;
     if (new_length < 0) new_length = 0;
   }
   // This runtime function finds any remaining arguments on the stack,
   // so we don't pass the arguments object.
   var result = %FunctionBindArguments(boundFunction, this,
                                       this_arg, new_length);
 
+  var name = this.name;
+  var bound_name = IS_STRING(name) ? name : "";
+  SetFunctionName(result, bound_name, "bound");

[Toon Verwaest, 2015/07/06 15:23:00]

This does not work since it sets the name on the SFI, and there's only 1 such
SFI for all bound functions.

function f() {};
var o = f.bind();
function g() {};
g.bind();
assertEquals("bound f", o.name)

+
   // We already have caller and arguments properties on functions,
   // which are non-configurable. It therefore makes no sence to
   // try to redefine these as defined by the spec. The spec says
   // that bind should make these throw a TypeError if get or set
   // is called and make them non-enumerable and non-configurable.
   // To be consistent with our normal functions we leave this as it is.
   // TODO(lrn): Do set these to be thrower.
   return result;
 }
 
@@ skipping 88 matching lines @@
   to.ObjectGetOwnPropertyKeys = ObjectGetOwnPropertyKeys;
   to.ObjectHasOwnProperty = ObjectHasOwnProperty;
   to.ObjectIsFrozen = ObjectIsFrozen;
   to.ObjectIsSealed = ObjectIsSealed;
   to.ObjectToString = ObjectToString;
   to.OwnPropertyKeys = OwnPropertyKeys;
   to.ToNameArray = ToNameArray;
 });
 
 })