Add --no-declaration-casts option to analyzer.

pkg/analyzer/lib/src/command_line/arguments.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.
 
 library analyzer.src.command_line.arguments;
 
 import 'dart:collection';
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/context/builder.dart';
 import 'package:analyzer/src/dart/sdk/sdk.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:args/args.dart';
 import 'package:path/path.dart';
 
 const String analysisOptionsFileOption = 'options';
 const String bazelAnalysisOptionsPath =
     'package:dart.analysis_options/default.yaml';
+const String declarationCastsFlag = 'declaration-casts';
 const String defineVariableOption = 'D';
 const String enableInitializingFormalAccessFlag = 'initializing-formal-access';
 const String enableStrictCallChecksFlag = 'enable-strict-call-checks';
 const String enableSuperMixinFlag = 'supermixin';
 const String flutterAnalysisOptionsPath =
     'package:flutter/analysis_options_user.yaml';
 const String ignoreUnrecognizedFlagsFlag = 'ignore-unrecognized-flags';
+const String implicitCastsFlag = 'implicit-casts';
 const String lintsFlag = 'lints';
-const String noImplicitCastsFlag = 'no-implicit-casts';
 const String noImplicitDynamicFlag = 'no-implicit-dynamic';
 const String packageDefaultAnalysisOptions = 'package-default-analysis-options';
 const String packageRootOption = 'package-root';
 const String packagesOption = 'packages';
 const String sdkPathOption = 'dart-sdk';
 
 const String sdkSummaryPathOption = 'dart-sdk-summary';
 const String strongModeFlag = 'strong';
 
 /**
  * Update [options] with the value of each analysis option command line flag.
  */
 void applyAnalysisOptionFlags(AnalysisOptionsImpl options, ArgResults args,
     {void verbosePrint(String text)}) {
   void verbose(String text) {
     if (verbosePrint != null) {
       verbosePrint('Analysis options: $text');
     }
   }
 
   if (args.wasParsed(enableStrictCallChecksFlag)) {
     options.enableStrictCallChecks = args[enableStrictCallChecksFlag];
     verbose('$enableStrictCallChecksFlag = ${options.enableStrictCallChecks}');
   }
   if (args.wasParsed(enableSuperMixinFlag)) {
     options.enableSuperMixins = args[enableSuperMixinFlag];
     verbose('$enableSuperMixinFlag = ${options.enableSuperMixins}');
   }
-  if (args.wasParsed(noImplicitCastsFlag)) {
-    options.implicitCasts = !args[noImplicitCastsFlag];
-    verbose('$noImplicitCastsFlag = ${options.implicitCasts}');
+  if (args.wasParsed(implicitCastsFlag)) {
+    options.implicitCasts = args[implicitCastsFlag];
+    verbose('$implicitCastsFlag = ${options.implicitCasts}');
+  }
+  if (args.wasParsed(declarationCastsFlag)) {
+    options.declarationCasts = args[declarationCastsFlag];
+    verbose('$declarationCastsFlag = ${options.declarationCasts}');
+  } else if (args.wasParsed(implicitCastsFlag)) {
+    options.declarationCasts = args[implicitCastsFlag];
+    verbose('$declarationCastsFlag = ${options.declarationCasts}');
   }
   if (args.wasParsed(noImplicitDynamicFlag)) {
     options.implicitDynamic = !args[noImplicitDynamicFlag];
     verbose('$noImplicitDynamicFlag = ${options.implicitDynamic}');
   }
   if (args.wasParsed(strongModeFlag)) {
     options.strongMode = args[strongModeFlag];
     verbose('$strongModeFlag = ${options.strongMode}');
   }
   try {
@@ skipping 97 matching lines @@
 void defineAnalysisArguments(ArgParser parser, {bool hide: true, ddc: false}) {
   parser.addOption(sdkPathOption, help: 'The path to the Dart SDK.');
   parser.addOption(analysisOptionsFileOption,
       help: 'Path to an analysis options file.');
   parser.addOption(packageRootOption,
       help: 'The path to a package root directory (deprecated). '
           'This option cannot be used with --packages.');
   parser.addFlag(strongModeFlag,
       help: 'Enable strong static checks (https://goo.gl/DqcBsw).',
       defaultsTo: ddc);
-  parser.addFlag(noImplicitCastsFlag,
-      negatable: false,
+  parser.addFlag(declarationCastsFlag,
+      negatable: true,
+      help:
+          'Disable declaration casts in strong mode (https://goo.gl/cTLz40).');
+  parser.addFlag(implicitCastsFlag,
+      negatable: true,
       help: 'Disable implicit casts in strong mode (https://goo.gl/cTLz40).');
   parser.addFlag(noImplicitDynamicFlag,
       negatable: false,
       help: 'Disable implicit dynamic (https://goo.gl/m0UgXD).');
 
   //
   // Hidden flags and options.
   //
   parser.addOption(defineVariableOption,
       abbr: 'D',
@@ skipping 160 matching lines @@
           .replaceAll('\r\n', '\n')
           .replaceAll('\r', '\n')
           .split('\n')
           .where((String line) => line.isNotEmpty));
     } on FileSystemException catch (e) {
       throw new Exception('Failed to read file specified by $lastArg : $e');
     }
   }
   return args;
 }