[runtime] Rewrite Function.prototype.toString in C++.

src/js/messages.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 ArrayJoin;
 var Bool16x8ToString;
 var Bool32x4ToString;
 var Bool8x16ToString;
 var callSiteReceiverSymbol =
     utils.ImportNow("call_site_receiver_symbol");
 var callSiteFunctionSymbol =
     utils.ImportNow("call_site_function_symbol");
 var callSitePositionSymbol =
     utils.ImportNow("call_site_position_symbol");
 var callSiteStrictSymbol =
     utils.ImportNow("call_site_strict_symbol");
 var FLAG_harmony_tostring;
 var Float32x4ToString;
 var formattedStackTraceSymbol =
     utils.ImportNow("formatted_stack_trace_symbol");
-var FunctionSourceString
 var GlobalObject = global.Object;
 var Int16x8ToString;
 var Int32x4ToString;
 var Int8x16ToString;
 var InternalArray = utils.InternalArray;
 var internalErrorSymbol = utils.ImportNow("internal_error_symbol");
 var ObjectDefineProperty;
 var ObjectToString = utils.ImportNow("object_to_string");
 var Script = utils.ImportNow("Script");
 var stackTraceSymbol = utils.ImportNow("stack_trace_symbol");
 var StringCharAt;
 var StringIndexOf;
 var StringSubstring;
 var SymbolToString;
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 var Uint16x8ToString;
 var Uint32x4ToString;
 var Uint8x16ToString;
 
 utils.Import(function(from) {
   ArrayJoin = from.ArrayJoin;
   Bool16x8ToString = from.Bool16x8ToString;
   Bool32x4ToString = from.Bool32x4ToString;
   Bool8x16ToString = from.Bool8x16ToString;
   Float32x4ToString = from.Float32x4ToString;
-  FunctionSourceString = from.FunctionSourceString;
   Int16x8ToString = from.Int16x8ToString;
   Int32x4ToString = from.Int32x4ToString;
   Int8x16ToString = from.Int8x16ToString;
   ObjectDefineProperty = from.ObjectDefineProperty;
   StringCharAt = from.StringCharAt;
   StringIndexOf = from.StringIndexOf;
   StringSubstring = from.StringSubstring;
   SymbolToString = from.SymbolToString;
   Uint16x8ToString = from.Uint16x8ToString;
   Uint32x4ToString = from.Uint32x4ToString;
@@ skipping 46 matching lines @@
   return `${name}: ${message}`;
 }
 
 function NoSideEffectsToString(obj) {
   if (IS_STRING(obj)) return obj;
   if (IS_NUMBER(obj)) return %_NumberToString(obj);
   if (IS_BOOLEAN(obj)) return obj ? 'true' : 'false';
   if (IS_UNDEFINED(obj)) return 'undefined';
   if (IS_NULL(obj)) return 'null';
   if (IS_FUNCTION(obj)) {
-    var str = %_Call(FunctionSourceString, obj, obj);
+    var str = %FunctionToString(obj);
     if (str.length > 128) {
       str = %_SubString(str, 0, 111) + "...<omitted>..." +
             %_SubString(str, str.length - 2, str.length);
     }
     return str;
   }
   if (IS_SYMBOL(obj)) return %_Call(SymbolToString, obj);
   if (IS_SIMD_VALUE(obj)) {
     switch (typeof(obj)) {
       case 'float32x4': return %_Call(Float32x4ToString, obj);
@@ skipping 872 matching lines @@
 utils.Export(function(to) {
   to.ErrorToString = ErrorToString;
   to.MakeError = MakeError;
   to.MakeRangeError = MakeRangeError;
   to.MakeSyntaxError = MakeSyntaxError;
   to.MakeTypeError = MakeTypeError;
   to.MakeURIError = MakeURIError;
 });
 
 });