Preliminary checked mirrors (not ready for review yet)

pkg/checked_mirrors/example/symbol.dart

+// Copyright (c) 2013, 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.
+
+/// Example illustrating how to use checked_mirrors, and how it works when you
+/// declare a symbol with [MirrorsUsed].
+library checked_mirrors.example.symbol;
+
+import 'package:checked_mirrors/checked_mirrors.dart';
+import 'package:checked_mirrors/control.dart' as control;
+import 'package:logging/logging.dart';
+
+// Typically this annotation goes in an import to 'dart:mirrors', we would like
+// to put it in the import of checked_mirrors, but we moved it here until
+// dartbug.com/10360 is fixed.
+@MirrorsUsed(symbols: 'x')
+const checked_mirrors_workaround_for_issue_10360 = 0;
+
+var a = new A();
+
+main() {
+  // This loads up the rules declared with @MirrorsUsed.
+  control.initialize(log: true);
+
+  // Print the warnings to the console.
+  Logger.root.onRecord.listen((r) => print(r));
+
+  // These are OK:
+  MirrorSystem.getName(#x);
+  MirrorSystem.getSymbol('x');
+
+  // These will issue a warning:
+  MirrorSystem.getName(#y);
+  MirrorSystem.getSymbol('y');
+}