Error reporting on File in dart:io

runtime/bin/utils.h

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef BIN_UTILS_H_
+#define BIN_UTILS_H_
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "include/dart_api.h"
+#include "platform/globals.h"
+
+class OSError {
+ public:
+  OSError();
+  OSError(int code, char* message) {
+    code_ = code;
+    SetMessage(message);
+  }
+  virtual ~OSError() { free(message_); }
+
+  int code() { return code_; }
+  void set_code(int code) { code_ = code; }
+  char* message() { return message_; }
+  void SetMessage(char* message) {
+    free(message_);
+    if (message == NULL) {
+      message_ = NULL;
+    } else {
+      message_ = strdup(message);
+    }
+  }
+
+ private:
+  int code_;
+  char* message_;
+
+  DISALLOW_COPY_AND_ASSIGN(OSError);
+};
+
+#endif  // BIN_UTILS_H_