Add StackOverflowError and expose error type to api.

src/messages.js

Index: src/messages.js
diff --git a/src/messages.js b/src/messages.js
index ca2da30472effb406677e912e6e6225dd5a175e7..e26a7440edb106c1e6bd1c700d65359c8a7306fb 100644
--- a/src/messages.js
+++ b/src/messages.js
@@ -129,10 +129,10 @@ var kMessages = {
   invalid_data_view_length:      ["Invalid data view length"],
   invalid_data_view_accessor_offset:
                                  ["Offset is outside the bounds of the DataView"],
-
-  stack_overflow:                ["Maximum call stack size exceeded"],
   invalid_time_value:            ["Invalid time value"],
   invalid_count_value:           ["Invalid count value"],
+  // StackOverflowError
+  stack_overflow:                ["Maximum call stack size exceeded"],
   // SyntaxError
   paren_in_arg_string:           ["Function arg string contains parenthesis"],
   not_isvar:                     ["builtin %IS_VAR: not a variable"],
@@ -252,6 +252,7 @@ function CanBeSafelyTreatedAsAnErrorObject(obj) {
     case 'SyntaxError':
     case 'TypeError':
     case 'URIError':
+    case 'StackOverflowError':
       return true;
   }
 
@@ -345,6 +346,11 @@ function MakeRangeError(type, args) {
 }
 
 
+function MakeStackOverflowError() {
+  return MakeGenericError($StackOverflowError, 'stack_overflow', []);
+}
+
+
 function MakeSyntaxError(type, args) {
   return MakeGenericError($SyntaxError, type, args);
 }
@@ -1187,7 +1193,7 @@ function captureStackTrace(obj, cons_opt) {
 function SetUpError() {
   // Define special error type constructors.
 
-  var DefineError = function(f) {
+  var DefineError = function(f, error_type) {
     // Store the error function in both the global object
     // and the runtime object. The function is fetched
     // from the runtime object when throwing errors from
@@ -1195,7 +1201,9 @@ function SetUpError() {
     // effects when overwriting the error functions from
     // user code.
     var name = f.name;
-    %SetProperty(global, name, f, DONT_ENUM);
+    if (name != 'StackOverflowError') {  // StackOverflowError is not in spec.
+      %SetProperty(global, name, f, DONT_ENUM);
+    }
     %SetProperty(builtins, '$' + name, f, DONT_ENUM | DONT_DELETE | READ_ONLY);
     // Configure the error function.
     if (name == 'Error') {
@@ -1207,6 +1215,9 @@ function SetUpError() {
       %FunctionSetPrototype(ErrorPrototype, $Object.prototype);
       %FunctionSetInstanceClassName(ErrorPrototype, 'Error');
       %FunctionSetPrototype(f, new ErrorPrototype());
+    } else if (name == 'StackOverflowError') {
+      // StackOverflowError extends RangeError for backward compatibility.
+      %FunctionSetPrototype(f, new $RangeError());
     } else {
       %FunctionSetPrototype(f, new $Error());
     }
@@ -1223,6 +1234,9 @@ function SetUpError() {
           %IgnoreAttributesAndSetProperty(
             this, 'message', ToString(m), DONT_ENUM);
         }
+        // Define error_type property as a private symbol.
+        %IgnoreAttributesAndSetProperty(
+          this, error_type_symbol, error_type, READ_ONLY | DONT_DELETE);
         captureStackTrace(this, f);
       } else {
         return new f(m);
@@ -1231,13 +1245,14 @@ function SetUpError() {
     %SetNativeFlag(f);
   };
 
-  DefineError(function Error() { });
-  DefineError(function TypeError() { });
-  DefineError(function RangeError() { });
-  DefineError(function SyntaxError() { });
-  DefineError(function ReferenceError() { });
-  DefineError(function EvalError() { });
-  DefineError(function URIError() { });
+  DefineError(function Error() { }, kError);
+  DefineError(function TypeError() { }, kTypeError);
+  DefineError(function RangeError() { }, kRangeError);
+  DefineError(function SyntaxError() { }, kSyntaxError);
+  DefineError(function ReferenceError() { }, kReferenceError);
+  DefineError(function EvalError() { }, kEvalError);
+  DefineError(function URIError() { }, kURIError);
+  DefineError(function StackOverflowError() { }, kStackOverflowError);
 }
 
 SetUpError();
@@ -1314,7 +1329,7 @@ InstallFunctions($Error.prototype, DONT_ENUM, ['toString', ErrorToString]);
 // Boilerplate for exceptions for stack overflows. Used from
 // Isolate::StackOverflow().
 function SetUpStackOverflowBoilerplate() {
-  var boilerplate = MakeRangeError('stack_overflow', []);
+  var boilerplate = MakeStackOverflowError();
 
   var error_string = boilerplate.name + ": " + boilerplate.message;