add verbose option to show hidden args

pkg/dev_compiler/lib/src/compiler/compiler.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:collection' show HashSet, Queue;
 import 'dart:convert' show BASE64, JSON, UTF8;
 import 'dart:io' show File;
 import 'package:analyzer/dart/element/element.dart' show LibraryElement;
 import 'package:analyzer/analyzer.dart'
     show AnalysisError, CompilationUnit, ErrorSeverity;
@@ skipping 287 matching lines @@
         closure = args['closure-experimental'],
         destructureNamedParams = args['destructure-named-params'],
         hoistInstanceCreation = args['hoist-instance-creation'],
         hoistSignatureTypes = args['hoist-signature-types'],
         nameTypeTests = args['name-type-tests'],
         hoistTypeTests = args['hoist-type-tests'],
         useAngular2Whitelist = args['unsafe-angular2-whitelist'],
         bazelMapping = _parseBazelMappings(args['bazel-mapping']),
         summaryOutPath = args['summary-out'];
 
-  static void addArguments(ArgParser parser) {
+  static void addArguments(ArgParser parser, {bool hide: true}) {
     parser
       ..addFlag('summarize', help: 'emit an API summary file', defaultsTo: true)
       ..addOption('summary-extension',
           help: 'file extension for Dart summary files',
           defaultsTo: 'sum',
-          hide: true)
+          hide: hide)
       ..addFlag('source-map', help: 'emit source mapping', defaultsTo: true)
       ..addFlag('source-map-comment',
           help: 'adds a sourceMappingURL comment to the end of the JS,\n'
               'disable if using X-SourceMap header',
           defaultsTo: true,
-          hide: true)
+          hide: hide)
       ..addFlag('inline-source-map',
           help: 'emit source mapping inline', defaultsTo: false)
       ..addFlag('emit-metadata',
           help: 'emit metadata annotations queriable via mirrors',
           defaultsTo: false)
       ..addFlag('closure-experimental',
           help: 'emit Closure Compiler-friendly code (experimental)',
           defaultsTo: false)
       ..addFlag('destructure-named-params',
-          help: 'Destructure named parameters', defaultsTo: false, hide: true)
+          help: 'Destructure named parameters', defaultsTo: false, hide: hide)
       ..addFlag('unsafe-force-compile',
           help: 'Compile code even if it has errors. ಠ_ಠ\n'
               'This has undefined behavior!',
           defaultsTo: false,
-          hide: true)
+          hide: hide)
       ..addFlag('repl-compile',
-          help: 'Compile code more permissively when in REPL mode allowing '
-              'access to private members across library boundaries.',
+          help: 'Compile code more permissively when in REPL mode\n'
+              'allowing access to private members across library boundaries.',
           defaultsTo: false,
-          hide: true)
+          hide: hide)
       ..addFlag('hoist-instance-creation',
           help: 'Hoist the class type from generic instance creations',
           defaultsTo: true,
-          hide: true)
+          hide: hide)
       ..addFlag('hoist-signature-types',
           help: 'Hoist types from class signatures',
           defaultsTo: false,
-          hide: true)
+          hide: hide)
       ..addFlag('name-type-tests',
-          help: 'Name types used in type tests', defaultsTo: true, hide: true)
+          help: 'Name types used in type tests', defaultsTo: true, hide: hide)
       ..addFlag('hoist-type-tests',
-          help: 'Hoist types used in type tests', defaultsTo: true, hide: true)
-      ..addFlag('unsafe-angular2-whitelist', defaultsTo: false, hide: true)
+          help: 'Hoist types used in type tests', defaultsTo: true, hide: hide)
+      ..addFlag('unsafe-angular2-whitelist', defaultsTo: false, hide: hide)
       ..addOption('bazel-mapping',
           help:
               '--bazel-mapping=genfiles/to/library.dart,to/library.dart uses \n'
               'to/library.dart as the path for library.dart in source maps.',
           allowMultiple: true,
           splitCommas: false,
-          hide: true)
+          hide: hide)
       ..addOption('summary-out',
-          help: 'location to write the summary file', hide: true);
+          help: 'location to write the summary file', hide: hide);
   }
 
   static Map<String, String> _parseBazelMappings(Iterable argument) {
     var mappings = <String, String>{};
     for (var mapping in argument) {
       var splitMapping = mapping.split(',');
       if (splitMapping.length >= 2) {
         mappings[path.absolute(splitMapping[0])] = splitMapping[1];
       }
     }
@@ skipping 181 matching lines @@
     // Fall back to a relative path.
     return path.toUri(path.relative(path.fromUri(uri), from: dir)).toString();
   }
 
   for (int i = 0; i < list.length; i++) {
     list[i] = transformUri(list[i]);
   }
   map['file'] = transformUri(map['file']);
   return map;
 }