toString() on generator functions prints with function*

src/v8natives.js

 // 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 1647 matching lines @@
 
 
 // ----------------------------------------------------------------------------
 // Function
 
 function FunctionSourceString(func) {
   while (%IsJSFunctionProxy(func)) {
     func = %GetCallTrap(func);
   }
 
-  // TODO(wingo): Print source using function* for generators.
   if (!IS_FUNCTION(func)) {
     throw new $TypeError('Function.prototype.toString is not generic');
   }
 
   var source = %FunctionGetSourceCode(func);
   if (!IS_STRING(source) || %FunctionIsBuiltin(func)) {
     var name = %FunctionGetName(func);
     if (name) {
       // Mimic what KJS does.
       return 'function ' + name + '() { [native code] }';
     } else {
       return 'function () { [native code] }';
     }
   }
 
   var name = %FunctionNameShouldPrintAsAnonymous(func)
       ? 'anonymous'
       : %FunctionGetName(func);
-  return 'function ' + name + source;
+  var head = %FunctionIsGenerator(func) ? 'function* ' : 'function ';
+  return head + name + source;
 }
 
 
 function FunctionToString() {
   return FunctionSourceString(this);
 }
 
 
 // ES5 15.3.4.5
 function FunctionBind(this_arg) { // Length is 1.
@@ skipping 95 matching lines @@
   %SetCode($Function, NewFunction);
   %SetProperty($Function.prototype, "constructor", $Function, DONT_ENUM);
 
   InstallFunctions($Function.prototype, DONT_ENUM, $Array(
     "bind", FunctionBind,
     "toString", FunctionToString
   ));
 }
 
 SetUpFunction();