[V8] Use Function.name in Error.stack

src/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.
 
 // -------------------------------------------------------------------
 
 var kMessages = {
   // Error
   cyclic_proto:                  ["Cyclic __proto__ value"],
   code_gen_from_strings:         ["%0"],
@@ skipping 805 matching lines @@
   var script = %FunctionGetScript(GET_PRIVATE(this, CallSiteFunctionKey));
   return script ? script.nameOrSourceURL() : null;
 }
 
 function CallSiteGetFunction() {
   return GET_PRIVATE(this, CallSiteStrictModeKey)
       ? UNDEFINED : GET_PRIVATE(this, CallSiteFunctionKey);
 }
 
 function CallSiteGetFunctionName() {
+  // See if the function has displayName
+  var fun = GET_PRIVATE(this, CallSiteFunctionKey);
+  var name = %GetDataProperty(fun, "displayName");
+  if (name && IS_STRING(name)) {

[Yang, 2015/02/12 14:15:29]

I think a single IS_STRING(name) would suffice, as undefined is not a String.

Unless you want to filter out the empty string, since it evaluates to false. In
which case it would be better to explicitly do a string length comparison.

[kozy, 2015/02/12 14:59:57]

Done.

+    return name;
+  }
   // See if the function knows its own name
-  var name = GET_PRIVATE(this, CallSiteFunctionKey).name;
+  name = fun.name;
   if (name) {
     return name;
   }
   name = %FunctionGetInferredName(GET_PRIVATE(this, CallSiteFunctionKey));
   if (name) {
     return name;
   }
   // Maybe this is an evaluation?
   var script = %FunctionGetScript(GET_PRIVATE(this, CallSiteFunctionKey));
   if (script && script.compilation_type == COMPILATION_TYPE_EVAL) {
@@ skipping 476 matching lines @@
 function SetUpStackOverflowBoilerplate() {
   var boilerplate = MakeRangeError('stack_overflow', []);
 
   %DefineAccessorPropertyUnchecked(
       boilerplate, 'stack', StackTraceGetter, StackTraceSetter, DONT_ENUM);
 
   return boilerplate;
 }
 
 var kStackOverflowBoilerplate = SetUpStackOverflowBoilerplate();