CLI support for `enableConditionalDirectives`.

pkg/analyzer_cli/lib/src/driver.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.driver;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
@@ skipping 253 matching lines @@
     }
     if (options.lints != _previousOptions.lints) {
       return false;
     }
     if (options.strongMode != _previousOptions.strongMode) {
       return false;
     }
     if (options.enableSuperMixins != _previousOptions.enableSuperMixins) {
       return false;
     }
+    if (options.enableConditionalDirectives !=
+        _previousOptions.enableConditionalDirectives) {
+      return false;
+    }
     return true;
   }
 
   /// Decide on the appropriate policy for which files need to be fully parsed
   /// and which files need to be diet parsed, based on [options], and return an
   /// [AnalyzeFunctionBodiesPredicate] that implements this policy.
   AnalyzeFunctionBodiesPredicate _chooseDietParsingPolicy(
       CommandLineOptions options) {
     if (_isBatch) {
       // As analyzer is currently implemented, once a file has been diet
@@ skipping 288 matching lines @@
 
     if (options.log) {
       AnalysisEngine.instance.logger = new StdLogger();
     }
 
     // Prepare context options.
     AnalysisOptionsImpl contextOptions = new AnalysisOptionsImpl();
     contextOptions.hint = !options.disableHints;
     contextOptions.enableStrictCallChecks = options.enableStrictCallChecks;
     contextOptions.enableSuperMixins = options.enableSuperMixins;
+    contextOptions.enableConditionalDirectives =
+        options.enableConditionalDirectives;
     contextOptions.generateImplicitErrors = options.showPackageWarnings;
     contextOptions.generateSdkErrors = options.showSdkWarnings;
     contextOptions.lint = options.lints;
     contextOptions.strongMode = options.strongMode;
     configureContextOptions(contextOptions);
 
     // Set context options.
     context.analysisOptions = contextOptions;
     context.sourceFactory.dartSdk.context.analysisOptions = contextOptions;
 
@@ skipping 144 matching lines @@
     for (var package in packages) {
       var packageName = path.basename(package.path);
       var realPath = package.resolveSymbolicLinksSync();
       result[packageName] = [
         PhysicalResourceProvider.INSTANCE.getFolder(realPath)
       ];
     }
     return result;
   }
 }