Recover from incorrectly ordered library tags.

dart/pkg/compiler/lib/src/warnings.dart

 // Copyright (c) 2011, 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.
 
 part of dart2js;
 
 const DONT_KNOW_HOW_TO_FIX = "Computer says no!";
 
 /**
  * The messages in this file should meet the following guide lines:
@@ skipping 2160 matching lines @@
   static const MessageKind DART_EXT_NOT_SUPPORTED = const MessageKind(
       "The 'dart-ext' scheme is not supported.",
       howToFix: "Try analyzing the code with the --allow-native-extensions "
                 "option.",
       examples: const ["""
 import 'dart-ext:main';
 
 main() {}
 """]);
 
+  static const MessageKind LIBRARY_TAG_MUST_BE_FIRST = const MessageKind(
+      "The library declaration should come before other declarations.",
+      howToFix: "Try moving the declaration to the top of the file.",
+      examples: const [
+"""
+import 'dart:core';
+library foo;
+main() {}
+""",
+      ]);
+
+  static const MessageKind ONLY_ONE_LIBRARY_TAG = const MessageKind(
+      "There can only be one library declaration.",
+      howToFix: "Try removing all other library declarations.",
+      examples: const [
+"""
+library foo;
+library bar;
+main() {}
+""",
+"""
+library foo;
+import 'dart:core';
+library bar;
+main() {}
+""",
+      ]);
+
+  static const MessageKind IMPORT_BEFORE_PARTS = const MessageKind(
+      "Import declarations should come before parts.",
+      howToFix: "Try moving this import further up in the file.",
+      examples: const [
+          const <String, String>{
+            'main.dart': """
+library test.main;
+part 'part.dart';
+import 'dart:core';
+main() {}
+""",
+            'part.dart': """
+part of test.main;
+""",
+      }]);
+
+  static const MessageKind EXPORT_BEFORE_PARTS = const MessageKind(
+      "Export declarations should come before parts.",
+      howToFix: "Try moving this export further up in the file.",
+      examples: const [
+          const <String, String>{
+            'main.dart': """
+library test.main;
+part 'part.dart';
+export 'dart:core';
+main() {}
+""",
+            'part.dart': """
+part of test.main;
+""",
+      }]);
+
   //////////////////////////////////////////////////////////////////////////////
   // Patch errors start.
   //////////////////////////////////////////////////////////////////////////////
 
   static const MessageKind PATCH_RETURN_TYPE_MISMATCH = const MessageKind(
       "Patch return type '#{patchReturnType}' does not match "
       "'#{originReturnType}' on origin method '#{methodName}'.");
 
   static const MessageKind PATCH_REQUIRED_PARAMETER_COUNT_MISMATCH =
       const MessageKind(
@@ skipping 176 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }