A MessageObject is a purely internal object to hold information about

src/api.cc

 // Copyright 2010 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 1460 matching lines @@
   return scope.Close(result);
 }
 
 
 v8::Handle<Value> Message::GetScriptResourceName() const {
   if (IsDeadCheck("v8::Message::GetScriptResourceName()")) {
     return Local<String>();
   }
   ENTER_V8;
   HandleScope scope;
-  i::Handle<i::JSObject> obj =
-      i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(Utils::OpenHandle(this));
   // Return this.script.name.
   i::Handle<i::JSValue> script =
-      i::Handle<i::JSValue>::cast(GetProperty(obj, "script"));
+      i::Handle<i::JSValue>::cast(i::Handle<i::Object>(message->script()));
   i::Handle<i::Object> resource_name(i::Script::cast(script->value())->name());
   return scope.Close(Utils::ToLocal(resource_name));
 }
 
 
 v8::Handle<Value> Message::GetScriptData() const {
   if (IsDeadCheck("v8::Message::GetScriptResourceData()")) {
     return Local<Value>();
   }
   ENTER_V8;
   HandleScope scope;
-  i::Handle<i::JSObject> obj =
-      i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(Utils::OpenHandle(this));
   // Return this.script.data.
   i::Handle<i::JSValue> script =
-      i::Handle<i::JSValue>::cast(GetProperty(obj, "script"));
+      i::Handle<i::JSValue>::cast(i::Handle<i::Object>(message->script()));
   i::Handle<i::Object> data(i::Script::cast(script->value())->data());
   return scope.Close(Utils::ToLocal(data));
 }
 
 
 v8::Handle<v8::StackTrace> Message::GetStackTrace() const {
   if (IsDeadCheck("v8::Message::GetStackTrace()")) {
     return Local<v8::StackTrace>();
   }
   ENTER_V8;
   HandleScope scope;
-  i::Handle<i::JSObject> obj =
-      i::Handle<i::JSObject>::cast(Utils::OpenHandle(this));
-  i::Handle<i::Object> stackFramesObj = GetProperty(obj, "stackFrames");
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(Utils::OpenHandle(this));
+  i::Handle<i::Object> stackFramesObj(message->stack_frames());
   if (!stackFramesObj->IsJSArray()) return v8::Handle<v8::StackTrace>();
   i::Handle<i::JSArray> stackTrace =
       i::Handle<i::JSArray>::cast(stackFramesObj);
   return scope.Close(Utils::StackTraceToLocal(stackTrace));
 }
 
 
 static i::Handle<i::Object> CallV8HeapFunction(const char* name,
                                                i::Handle<i::Object> recv,
                                                int argc,
@@ skipping 19 matching lines @@
                             1,
                             argv,
                             has_pending_exception);
 }
 
 
 int Message::GetLineNumber() const {
   ON_BAILOUT("v8::Message::GetLineNumber()", return kNoLineNumberInfo);
   ENTER_V8;
   HandleScope scope;
+
   EXCEPTION_PREAMBLE();
   i::Handle<i::Object> result = CallV8HeapFunction("GetLineNumber",
                                                    Utils::OpenHandle(this),
                                                    &has_pending_exception);
   EXCEPTION_BAILOUT_CHECK(0);
   return static_cast<int>(result->Number());
 }
 
 
 int Message::GetStartPosition() const {
   if (IsDeadCheck("v8::Message::GetStartPosition()")) return 0;
   ENTER_V8;
   HandleScope scope;
-
-  i::Handle<i::JSObject> data_obj = Utils::OpenHandle(this);
-  return static_cast<int>(GetProperty(data_obj, "startPos")->Number());
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(Utils::OpenHandle(this));
+  return message->start_position();
 }
 
 
 int Message::GetEndPosition() const {
   if (IsDeadCheck("v8::Message::GetEndPosition()")) return 0;
   ENTER_V8;
   HandleScope scope;
-  i::Handle<i::JSObject> data_obj = Utils::OpenHandle(this);
-  return static_cast<int>(GetProperty(data_obj, "endPos")->Number());
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(Utils::OpenHandle(this));
+  return message->end_position();
 }
 
 
 int Message::GetStartColumn() const {
   if (IsDeadCheck("v8::Message::GetStartColumn()")) return kNoColumnInfo;
   ENTER_V8;
   HandleScope scope;
   i::Handle<i::JSObject> data_obj = Utils::OpenHandle(this);
   EXCEPTION_PREAMBLE();
   i::Handle<i::Object> start_col_obj = CallV8HeapFunction(
       "GetPositionInLine",
       data_obj,
       &has_pending_exception);
   EXCEPTION_BAILOUT_CHECK(0);
   return static_cast<int>(start_col_obj->Number());
 }
 
 
 int Message::GetEndColumn() const {
   if (IsDeadCheck("v8::Message::GetEndColumn()")) return kNoColumnInfo;
   ENTER_V8;
   HandleScope scope;
   i::Handle<i::JSObject> data_obj = Utils::OpenHandle(this);
   EXCEPTION_PREAMBLE();
   i::Handle<i::Object> start_col_obj = CallV8HeapFunction(
       "GetPositionInLine",
       data_obj,
       &has_pending_exception);
   EXCEPTION_BAILOUT_CHECK(0);
-  int start = static_cast<int>(GetProperty(data_obj, "startPos")->Number());
-  int end = static_cast<int>(GetProperty(data_obj, "endPos")->Number());
+  i::Handle<i::JSMessageObject> message =
+      i::Handle<i::JSMessageObject>::cast(data_obj);
+  int start = message->start_position();
+  int end = message->end_position();
   return static_cast<int>(start_col_obj->Number()) + (end - start);
 }
 
 
 Local<String> Message::GetSourceLine() const {
   ON_BAILOUT("v8::Message::GetSourceLine()", return Local<String>());
   ENTER_V8;
   HandleScope scope;
   EXCEPTION_PREAMBLE();
   i::Handle<i::Object> result = CallV8HeapFunction("GetSourceLine",
@@ skipping 3535 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* thread_local =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   thread_local->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal