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

pkg/analyzer/lib/src/generated/engine.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.
 
 library analyzer.src.generated.engine;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:typed_data';
 
@@ skipping 1343 matching lines @@
    * bodies.
    */
   AnalyzeFunctionBodiesPredicate _analyzeFunctionBodiesPredicate =
       _analyzeAllFunctionBodies;
 
   /**
    * The cached [signature].
    */
   Uint32List _signature;
 
+  /**
+   * A flag indicating whether declaration casts are allowed in [strongMode]
+   * (they are always allowed in Dart 1.0 mode).
+   *
+   * This option is experimental and subject to change.
+   */
+  bool declarationCasts = true;
+
   @override
   @deprecated
   int cacheSize = 64;
 
   @override
   bool dart2jsHint = false;
 
   @override
   bool enableAssertInitializer = false;
 
@@ skipping 110 matching lines @@
     errorProcessors = options.errorProcessors;
     excludePatterns = options.excludePatterns;
     generateImplicitErrors = options.generateImplicitErrors;
     generateSdkErrors = options.generateSdkErrors;
     hint = options.hint;
     lint = options.lint;
     lintRules = options.lintRules;
     preserveComments = options.preserveComments;
     strongMode = options.strongMode;
     if (options is AnalysisOptionsImpl) {
+      declarationCasts = options.declarationCasts;
       strongModeHints = options.strongModeHints;
       implicitCasts = options.implicitCasts;
       nonnullableTypes = options.nonnullableTypes;
       implicitDynamic = options.implicitDynamic;
     }
     trackCacheDependencies = options.trackCacheDependencies;
     disableCacheFlushing = options.disableCacheFlushing;
     patchPaths = options.patchPaths;
   }
 
@@ skipping 96 matching lines @@
   void set lintRules(List<Linter> rules) {
     _lintRules = rules;
   }
 
   @override
   Uint32List get signature {
     if (_signature == null) {
       ApiSignature buffer = new ApiSignature();
 
       // Append boolean flags.
+      buffer.addBool(declarationCasts);
       buffer.addBool(enableAssertInitializer);
       buffer.addBool(enableLazyAssignmentOperators);
       buffer.addBool(enableStrictCallChecks);
       buffer.addBool(enableSuperMixins);
       buffer.addBool(enableUriInPartOf);
       buffer.addBool(implicitCasts);
       buffer.addBool(implicitDynamic);
       buffer.addBool(strongMode);
       buffer.addBool(strongModeHints);
 
@@ skipping 11 matching lines @@
 
       // Hash and convert to Uint32List.
       List<int> bytes = buffer.toByteList();
       _signature = new Uint8List.fromList(bytes).buffer.asUint32List();
     }
     return _signature;
   }
 
   @override
   void resetToDefaults() {
+    declarationCasts = true;
     dart2jsHint = false;
     disableCacheFlushing = false;
     enableAssertInitializer = false;
     enableLazyAssignmentOperators = false;
     enableStrictCallChecks = false;
     enableSuperMixins = false;
     enableTiming = false;
     enableUriInPartOf = true;
     _errorProcessors = null;
     _excludePatterns = null;
@@ skipping 1193 matching lines @@
    */
   bool get wereSourcesAdded => _changeSet.addedSources.length > 0;
 
   /**
    * Return `true` if any sources were removed or deleted.
    */
   bool get wereSourcesRemoved =>
       _changeSet.removedSources.length > 0 ||
       _changeSet.removedContainers.length > 0;
 }