Use ansi color in the dartanalyzer cli output.

pkg/analyzer_cli/lib/src/options.dart

 // Copyright (c) 2015, 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 analyzer_cli.src.options;
 
 import 'dart:io';
 
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/src/command_line/arguments.dart';
 import 'package:analyzer/src/context/builder.dart';
+import 'package:analyzer_cli/src/ansi.dart' as ansi;
 import 'package:analyzer_cli/src/driver.dart';
 import 'package:args/args.dart';
 import 'package:cli_util/cli_util.dart' show getSdkDir;
 
 const _binaryName = 'dartanalyzer';
 
 /// Shared exit handler.
 ///
 /// *Visible for testing.*
 ExitHandler exitHandler = exit;
@@ skipping 114 matching lines @@
 
   /// Whether to treat lints as fatal
   final bool lintsAreFatal;
 
   /// Whether to use memory byte store for analysis driver.
   final bool useAnalysisDriverMemoryByteStore;
 
   /// Emit output in a verbose mode.
   final bool verbose;
 
+  /// Use ANSI color codes for output.
+  final bool color;
+
   /// Initialize options from the given parsed [args].
   CommandLineOptions._fromArgs(ArgResults args)
       : buildAnalysisOutput = args['build-analysis-output'],
         buildMode = args['build-mode'],
         buildModePersistentWorker = args['persistent_worker'],
         buildSummaryInputs = args['build-summary-input'] as List<String>,
         buildSummaryOnly = args['build-summary-only'],
         buildSummaryOnlyDiet = args['build-summary-only-diet'],
         buildSummaryOutput = args['build-summary-output'],
         buildSummaryOutputSemantic = args['build-summary-output-semantic'],
@@ skipping 18 matching lines @@
         showPackageWarningsPrefix = args['x-package-warnings-prefix'],
         showSdkWarnings = args['sdk-warnings'],
         _sourceFiles = args.rest,
         warningsAreFatal = args['fatal-warnings'],
         strongMode = args['strong'],
         implicitCasts = !args['no-implicit-casts'],
         implicitDynamic = !args['no-implicit-dynamic'],
         lintsAreFatal = args['fatal-lints'],
         useAnalysisDriverMemoryByteStore =
             args['use-analysis-driver-memory-byte-store'],
-        verbose = args['verbose'];
+        verbose = args['verbose'],
+        color = args['color'];
 
   /// The path to an analysis options file
   String get analysisOptionsFile =>
       contextBuilderOptions.defaultAnalysisOptionsFilePath;
 
   /// A table mapping the names of defined variables to their values.
   Map<String, String> get definedVariables =>
       contextBuilderOptions.declaredVariables;
 
   /// Whether to strictly follow the specification when generating warnings on
@@ skipping 181 matching lines @@
           hide: hide)
       ..addFlag('build-summary-only-diet',
           help: 'Diet parse function bodies.',
           defaultsTo: false,
           negatable: false,
           hide: hide)
       ..addFlag('build-suppress-exit-code',
           help: 'Exit with code 0 even if errors are found.',
           defaultsTo: false,
           negatable: false,
+          hide: hide)
+      ..addFlag('color',
+          help: 'Use asni colors when printing messages.',
+          defaultsTo: ansi.terminalSupportsAnsi(),
           hide: hide);
 
     // Hidden flags.
     if (!hide) {
       parser.addSeparator('Less frequently used flags:');
     }
 
     parser
       ..addFlag('batch',
           help: 'Read commands from standard input (for testing).',
@@ skipping 120 matching lines @@
         'Usage: $_binaryName [options...] <directory or list of files>');
     errorSink.writeln('');
     errorSink.writeln(parser.usage);
     errorSink.writeln('');
     errorSink.writeln('''
 Run "dartanalyzer -h -v" for verbose help output, including less commonly used options.
 For more information, see http://www.dartlang.org/tools/analyzer.
 ''');
   }
 }