Adds a repeatable --url_mapping flag to dartanalyzer

pkg/analyzer/lib/options.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.
 
 library options;
 
 import 'dart:io';
 
 import 'package:args/args.dart';
 
@@ skipping 47 matching lines @@
 
   /** The source files to analyze */
   final List<String> sourceFiles;
 
   /** Whether to show both cold and hot performance statistics */
   final bool warmPerf;
 
   /** Whether to treat warnings as fatal */
   final bool warningsAreFatal;
 
+  /** A table mapping library URIs to the file system path where the library
+   *  source is located.
+   */
+  final Map<String, String> customUrlMappings;
+
   /**
    * Initialize options from the given parsed [args].
    */
   CommandLineOptions._fromArgs(ArgResults args, Map<String,
-      String> definedVariables)
+      String> definedVariables, Map<String, String> customUrlMappings)
       : dartSdkPath = args['dart-sdk'],
         this.definedVariables = definedVariables,
         disableHints = args['no-hints'],
         displayVersion = args['version'],
         enableTypeChecks = args['enable_type_checks'],
         ignoreUnrecognizedFlags = args['ignore-unrecognized-flags'],
         log = args['log'],
         machineFormat = args['machine'] || args['format'] == 'machine',
         packageRootPath = args['package-root'],
         perf = args['perf'],
         shouldBatch = args['batch'],
         showPackageWarnings = args['show-package-warnings'] ||
           args['package-warnings'],
         showSdkWarnings = args['show-sdk-warnings'] || args['warnings'],
         sourceFiles = args.rest,
         warmPerf = args['warm-perf'],
-        warningsAreFatal = args['fatal-warnings'];
+        warningsAreFatal = args['fatal-warnings'],
+        this.customUrlMappings = customUrlMappings;
 
   /**
    * Parse [args] into [CommandLineOptions] describing the specified
    * analyzer options. In case of a format error, prints error and exists.
    */
   static CommandLineOptions parse(List<String> args) {
     CommandLineOptions options = _parse(args);
     // check SDK
     {
       var sdkPath = options.dartSdkPath;
@@ skipping 92 matching lines @@
             'show-sdk-warnings',
             help: 'Show warnings from SDK imports (deprecated)',
             defaultsTo: false,
             negatable: false)
         ..addFlag(
             'help',
             abbr: 'h',
             help: 'Display this help message',
             defaultsTo: false,
             negatable: false)
+        ..addOption(
+            'url-mapping',
+            help: '--url-mapping=libraryUri,/path/to/library.dart directs the '
+                  'analyzer to use "library.dart" as the source for an import '
+                  'of "libraryUri"',
+            allowMultiple: true)
         //
         // Hidden flags.
         //
         ..addFlag(
             'enable-async',
             help: 'Enable support for the proposed async feature',
             defaultsTo: false,
             negatable: false,
             hide: true)
         ..addFlag(
@@ skipping 41 matching lines @@
         }
       } else if (results['version']) {
         print('$_BINARY_NAME version ${_getVersion()}');
         exit(0);
       } else {
         if (results.rest.isEmpty) {
           _showUsage(parser);
           exit(15);
         }
       }
-      return new CommandLineOptions._fromArgs(results, definedVariables);
+      Map<String, String> customUrlMappings = <String, String>{};
+      for (String mapping in results['url-mapping']) {
+        List<String> splitMapping = mapping.split(',');
+        if (splitMapping.length != 2) {
+          _showUsage(parser);
+          exit(15);
+        }
+        customUrlMappings[splitMapping[0]] = splitMapping[1];
+      }
+      return new CommandLineOptions._fromArgs(
+          results, definedVariables, customUrlMappings);
     } on FormatException catch (e) {
       print(e.message);
       _showUsage(parser);
       exit(15);
     }
 
   }
 
   static _showUsage(parser) {
     print('Usage: $_BINARY_NAME [options...] <libraries to analyze...>');
@@ skipping 128 matching lines @@
 
   _getNextFlagIndex(args, i) {
     for ( ; i < args.length; ++i) {
       if (args[i].startsWith('--')) {
         return i;
       }
     }
     return i;
   }
 }