Add a fallback mode for building summaries.

pkg/analyzer_cli/lib/src/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_cli.src.options;
 
 import 'dart:io';
 
 import 'package:analyzer_cli/src/driver.dart';
 import 'package:args/args.dart';
@@ skipping 37 matching lines @@
   /// Whether to use diet parsing, i.e. skip function bodies. We don't need to
   /// analyze function bodies to use summaries during future compilation steps.
   final bool buildSummaryOnlyDiet;
 
   /// Whether to use exclude informative data from created summaries.
   final bool buildSummaryExcludeInformative;
 
   /// The path to output the summary when creating summaries in build mode.
   final String buildSummaryOutput;
 
+  /// Whether to output a summary in "fallback mode".
+  final bool buildSummaryFallback;
+
   /// Whether to suppress a nonzero exit code in build mode.
   final bool buildSuppressExitCode;
 
   /// The path to the dart SDK
   String dartSdkPath;
 
   /// A table mapping the names of defined variables to their values.
   final Map<String, String> definedVariables;
 
   /// Whether to report hints
@@ skipping 63 matching lines @@
   final bool warningsAreFatal;
 
   /// Whether to use strong static checking.
   final bool strongMode;
 
   /// Initialize options from the given parsed [args].
   CommandLineOptions._fromArgs(
       ArgResults args, Map<String, String> definedVariables)
       : buildAnalysisOutput = args['build-analysis-output'],
         buildMode = args['build-mode'],
+        buildSummaryFallback = args['build-summary-fallback'],
         buildSummaryInputs = args['build-summary-input'],
         buildSummaryOnly = args['build-summary-only'],
         buildSummaryOnlyDiet = args['build-summary-only-diet'],
         buildSummaryExcludeInformative =
             args['build-summary-exclude-informative'],
         buildSummaryOutput = args['build-summary-output'],
         buildSuppressExitCode = args['build-suppress-exit-code'],
         dartSdkPath = args['dart-sdk'],
         definedVariables = definedVariables,
         analysisOptionsFile = args['options'],
@@ skipping 198 matching lines @@
       ..addFlag('build-summary-only-diet',
           help: 'Diet parse function bodies.',
           defaultsTo: false,
           negatable: false,
           hide: true)
       ..addFlag('build-summary-exclude-informative',
           help: 'Exclude @informative information (docs, offsets, etc).',
           defaultsTo: false,
           negatable: false,
           hide: true)
+      ..addFlag('build-summary-fallback',
+          help: 'If outputting a summary, output it in fallback mode.',
+          defaultsTo: false,
+          negatable: false,
+          hide: true)
       ..addFlag('build-suppress-exit-code',
           help: 'Exit with code 0 even if errors are found.',
           defaultsTo: false,
           negatable: false,
           hide: true)
       //
       // Hidden flags.
       //
       ..addFlag('enable-async',
           help: 'Enable support for the proposed async feature.',
@@ skipping 227 matching lines @@
 
   int _getNextFlagIndex(args, i) {
     for (; i < args.length; ++i) {
       if (args[i].startsWith('--')) {
         return i;
       }
     }
     return i;
   }
 }