Option support for `enableGenericMethods`.

pkg/analyzer/lib/src/task/options.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.src.task.options;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/plugin/options.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 17 matching lines @@
 
 /// Configure this [context] based on configuration details specified in
 /// the given [options].
 void configureContextOptions(
         AnalysisContext context, Map<String, YamlNode> options) =>
     _processor.configure(context, options);
 
 /// `analyzer` analysis options constants.
 class AnalyzerOptions {
   static const String analyzer = 'analyzer';
+  static const String enableGenericMethods = 'enableGenericMethods';
   static const String enableSuperMixins = 'enableSuperMixins';
   static const String errors = 'errors';
   static const String exclude = 'exclude';
   static const String language = 'language';
   static const String plugins = 'plugins';
   static const String strong_mode = 'strong-mode';
 
   /// Ways to say `ignore`.
   static const List<String> ignoreSynonyms = const ['ignore', 'false'];
 
   /// Ways to say `include`.
   static const List<String> includeSynonyms = const ['include', 'true'];
 
   /// Ways to say `true` or `false`.
   static const List<String> trueOrFalse = const ['true', 'false'];
 
   /// Supported top-level `analyzer` options.
   static const List<String> topLevel = const [
     errors,
     exclude,
     language,
     plugins,
     strong_mode
   ];
 
   /// Supported `analyzer` language configuration options.
-  static const List<String> languageOptions = const [enableSuperMixins];
+  static const List<String> languageOptions = const [
+    enableGenericMethods,
+    enableSuperMixins
+  ];
 }
 
 /// Validates `analyzer` options.
 class AnalyzerOptionsValidator extends CompositeValidator {
   AnalyzerOptionsValidator()
       : super([
           new TopLevelAnalyzerOptionsValidator(),
           new ErrorFilterOptionValidator(),
           new LanguageOptionValidator()
         ]);
@@ skipping 309 matching lines @@
 
   void setLanguageOptions(AnalysisContext context, YamlNode configs) {
     if (configs is YamlMap) {
       configs.nodes.forEach((k, v) {
         String feature;
         if (k is YamlScalar && v is YamlScalar) {
           feature = k.value?.toString();
           if (feature == AnalyzerOptions.enableSuperMixins) {
             if (isTrue(v.value)) {
               AnalysisOptionsImpl options =
-                  new AnalysisOptionsImpl.from(context.analysisOptions);
+              new AnalysisOptionsImpl.from(context.analysisOptions);
               options.enableSuperMixins = true;
               context.analysisOptions = options;
             }
           }
+          if (feature == AnalyzerOptions.enableGenericMethods) {
+            if (isTrue(v.value)) {
+              AnalysisOptionsImpl options =
+              new AnalysisOptionsImpl.from(context.analysisOptions);
+              options.enableGenericMethods = true;
+              context.analysisOptions = options;
+            }
+          }
         }
       });
     }
   }
 
   void setStrongMode(AnalysisContext context, bool strongMode) {
     if (context.analysisOptions.strongMode != strongMode) {
       AnalysisOptionsImpl options =
           new AnalysisOptionsImpl.from(context.analysisOptions);
       options.strongMode = strongMode;
       context.analysisOptions = options;
     }
   }
 }