Add flag to disable hashing

lib/src/options.dart

 // Copyright (c) 2014, 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.
 
 /// Set of flags and options passed to the compiler
 library dev_compiler.src.options;
 
 import 'dart:io';
 
 import 'package:args/args.dart';
@@ skipping 133 matching lines @@
   /// File where to start compilation from.
   final String entryPointFile;
 
   /// Whether to allow casts in constant contexts.
   @override
   final bool allowConstCasts;
 
   /// Whether to run as a development server.
   final bool serverMode;
 
+  /// Whether to enable hash-based caching of files.
+  final bool enableHashing;
+
   /// Port used for the HTTP server when [serverMode] is on.
   final int port;
 
   /// Host name or address for HTTP server when [serverMode] is on.
   final String host;
 
   /// Whether to use covariant generics
   @override
   final bool covariantGenerics;
 
@@ skipping 61 matching lines @@
       this.covariantGenerics: true, this.relaxedCasts: true,
       this.useMultiPackage: false, this.packageRoot: 'packages/',
       this.packagePaths: const <String>[],
       this.inferDownwards: RulesOptions.inferDownwardsDefault,
       this.inferFromOverrides: ResolverOptions.inferFromOverridesDefault,
       this.inferTransitively: ResolverOptions.inferTransitivelyDefault,
       this.onlyInferConstsAndFinalFields: ResolverOptions.onlyInferConstAndFinalFieldsDefault,
       this.nonnullableTypes: TypeOptions.NONNULLABLE_TYPES, this.help: false,
       this.useMockSdk: false, this.dartSdkPath, this.logLevel: Level.SEVERE,
       this.emitSourceMaps: true, this.entryPointFile: null,
-      this.serverMode: false, this.host: 'localhost', this.port: 8080,
-      this.runtimeDir});
+      this.serverMode: false, this.enableHashing: false, this.host: 'localhost',
+      this.port: 8080, this.runtimeDir});
 }
 
 /// Parses options from the command-line
 CompilerOptions parseOptions(List<String> argv) {
   ArgResults args = argParser.parse(argv);
   var serverMode = args['server'];
+  var enableHashing = args['hashing'];
+  if (enableHashing == null) {
+    enableHashing = serverMode;
+  }
   var logLevel = serverMode ? Level.ALL : Level.SEVERE;
   var levelName = args['log'];
   if (levelName != null) {
     levelName = levelName.toUpperCase();
     logLevel = Level.LEVELS.firstWhere((l) => l.name == levelName,
         orElse: () => logLevel);
   }
   var useColors = stdioType(stdout) == StdioType.TERMINAL;
   var sdkPath = args['dart-sdk'];
   if (sdkPath == null && !args['mock-sdk']) {
@@ skipping 34 matching lines @@
       onlyInferConstsAndFinalFields: args['infer-only-finals'],
       nonnullableTypes: optionsToList(args['nonnullable'],
           defaultValue: TypeOptions.NONNULLABLE_TYPES),
       help: args['help'],
       useMockSdk: args['mock-sdk'],
       dartSdkPath: sdkPath,
       logLevel: logLevel,
       emitSourceMaps: args['source-maps'],
       entryPointFile: args.rest.length == 0 ? null : args.rest.first,
       serverMode: serverMode,
+      enableHashing: enableHashing,
       host: args['host'],
       port: int.parse(args['port']),
       runtimeDir: runtimeDir);
 }
 
 final ArgParser argParser = new ArgParser()
   // resolver/checker options
   ..addFlag('allow-const-casts',
       help: 'Allow casts in const contexts', defaultsTo: true)
   ..addFlag('sdk-check',
@@ skipping 46 matching lines @@
       help: 'if using the multi-package resolver, the list of directories to\n'
       'look for packages in.', defaultsTo: '')
   ..addFlag('source-maps',
       help: 'Whether to emit source map files', defaultsTo: true)
   ..addOption('runtime-dir',
       help: 'Where to find dev_compiler\'s runtime files', defaultsTo: null)
 
   // general options
   ..addFlag('help', abbr: 'h', help: 'Display this message')
   ..addFlag('server', help: 'Run as a development server.', defaultsTo: false)
+  ..addFlag('hashing',
+      help: 'Enable hash-based file caching.', defaultsTo: null)
   ..addOption('host',
       help: 'Host name or address to serve files from, e.g. --host=0.0.0.0\n'
       'to listen on all interfaces (used only when --serve is on)',
       defaultsTo: 'localhost')
   ..addOption('port',
       help: 'Port to serve files from (used only when --serve is on)',
       defaultsTo: '8080')
   ..addFlag('force-compile',
       help: 'Compile code with static errors', defaultsTo: false)
   ..addOption('log', abbr: 'l', help: 'Logging level (defaults to severe)')
@@ skipping 47 matching lines @@
     // The pub-cache directory is two levels up, but we verify that the layout
     // looks correct.
     if (path.basename(dir) != 'dev_compiler') return null;
     dir = path.dirname(dir);
     if (path.basename(dir) != 'global_packages') return null;
     dir = path.dirname(dir);
     return path.join(dir, cacheDir, 'lib', 'runtime');
   }
   return null;
 }