Revert "Revert "Use native async/await support in pub.""

sdk/lib/_internal/pub_generated/lib/src/command/barback.dart

Index: sdk/lib/_internal/pub_generated/lib/src/command/barback.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/command/barback.dart b/sdk/lib/_internal/pub_generated/lib/src/command/barback.dart
deleted file mode 100644
index 5fdc519b6abbe369bd9e96a99addbb0489daecf3..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/command/barback.dart
+++ /dev/null
@@ -1,204 +0,0 @@
-// Copyright (c) 2013, 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 pub.command.barback;
-
-import 'dart:async';
-
-import 'package:barback/barback.dart';
-import 'package:path/path.dart' as path;
-
-import '../command.dart';
-import '../io.dart';
-import '../log.dart' as log;
-import '../utils.dart';
-
-final _arrow = getSpecial('\u2192', '=>');
-
-/// The set of top level directories in the entrypoint package that are built
-/// when the user does "--all".
-final _allSourceDirectories =
-    new Set<String>.from(["benchmark", "bin", "example", "test", "web"]);
-
-/// Shared base class for [BuildCommand] and [ServeCommand].
-abstract class BarbackCommand extends PubCommand {
-  /// The build mode.
-  BarbackMode get mode => new BarbackMode(argResults["mode"]);
-
-  /// The directories in the entrypoint package that should be added to the
-  /// build environment.
-  final sourceDirectories = new Set<String>();
-
-  /// The default build mode.
-  BarbackMode get defaultMode => BarbackMode.RELEASE;
-
-  /// Override this to specify the default source directories if none are
-  /// provided on the command line.
-  List<String> get defaultSourceDirectories;
-
-  BarbackCommand() {
-    argParser.addOption(
-        "mode",
-        defaultsTo: defaultMode.toString(),
-        help: "Mode to run transformers in.");
-
-    argParser.addFlag(
-        "all",
-        help: "Use all default source directories.",
-        defaultsTo: false,
-        negatable: false);
-  }
-
-  Future run() {
-    // Switch to JSON output if specified. We need to do this before parsing
-    // the source directories so an error will be correctly reported in JSON
-    // format.
-    log.json.enabled =
-        argResults.options.contains("format") && argResults["format"] == "json";
-
-    _parseSourceDirectories();
-    return onRunTransformerCommand();
-  }
-
-  /// Override this to run the actual command.
-  Future onRunTransformerCommand();
-
-  /// Parses the command-line arguments to determine the set of source
-  /// directories to add to the build environment.
-  ///
-  /// If there are no arguments, this will just be [defaultSourceDirectories].
-  ///
-  /// If the `--all` flag is set, then it will be all default directories
-  /// that exist.
-  ///
-  /// Otherwise, all arguments should be the paths of directories to include.
-  ///
-  /// Throws an exception if the arguments are invalid.
-  void _parseSourceDirectories() {
-    if (argResults["all"]) {
-      _addAllDefaultSources();
-      return;
-    }
-
-    // If no directories were specified, use the defaults.
-    if (argResults.rest.isEmpty) {
-      _addDefaultSources();
-      return;
-    }
-
-    sourceDirectories.addAll(argResults.rest);
-
-    // Prohibit "lib".
-    var disallowed = sourceDirectories.where((dir) {
-      var parts = path.split(path.normalize(dir));
-      return parts.isNotEmpty && parts.first == "lib";
-    });
-
-    if (disallowed.isNotEmpty) {
-      usageException(
-          _directorySentence(disallowed, "is", "are", "not allowed"));
-    }
-
-    // Make sure the source directories don't reach out of the package.
-    var invalid = sourceDirectories.where((dir) => !path.isWithin('.', dir));
-    if (invalid.isNotEmpty) {
-      usageException(
-          _directorySentence(invalid, "isn't", "aren't", "in this package"));
-    }
-
-    // Make sure all of the source directories exist.
-    var missing =
-        sourceDirectories.where((dir) => !dirExists(entrypoint.root.path(dir)));
-
-    if (missing.isNotEmpty) {
-      dataError(_directorySentence(missing, "does", "do", "not exist"));
-    }
-
-    // Make sure the directories don't overlap.
-    var sources = sourceDirectories.toList();
-    var overlapping = new Set();
-    for (var i = 0; i < sources.length; i++) {
-      for (var j = i + 1; j < sources.length; j++) {
-        if (path.isWithin(sources[i], sources[j]) ||
-            path.isWithin(sources[j], sources[i])) {
-          overlapping.add(sources[i]);
-          overlapping.add(sources[j]);
-        }
-      }
-    }
-
-    if (overlapping.isNotEmpty) {
-      usageException(
-          _directorySentence(overlapping, "cannot", "cannot", "overlap"));
-    }
-  }
-
-  /// Handles "--all" by adding all default source directories that are
-  /// present.
-  void _addAllDefaultSources() {
-    if (argResults.rest.isNotEmpty) {
-      usageException('Directory names are not allowed if "--all" is passed.');
-    }
-
-    // Include every build directory that exists in the package.
-    var dirs =
-        _allSourceDirectories.where((dir) => dirExists(entrypoint.root.path(dir)));
-
-    if (dirs.isEmpty) {
-      var defaultDirs =
-          toSentence(_allSourceDirectories.map((name) => '"$name"'));
-      dataError(
-          'There are no source directories present.\n'
-              'The default directories are $defaultDirs.');
-    }
-
-    sourceDirectories.addAll(dirs);
-  }
-
-  /// Adds the default sources that should be used if no directories are passed
-  /// on the command line.
-  void _addDefaultSources() {
-    sourceDirectories.addAll(
-        defaultSourceDirectories.where((dir) => dirExists(entrypoint.root.path(dir))));
-
-    // TODO(rnystrom): Hackish. Assumes there will only be one or two
-    // default sources. That's true for pub build and serve, but isn't as
-    // general as it could be.
-    if (sourceDirectories.isEmpty) {
-      var defaults;
-      if (defaultSourceDirectories.length == 1) {
-        defaults = 'a "${defaultSourceDirectories.first}" directory';
-      } else {
-        defaults =
-            '"${defaultSourceDirectories[0]}" and/or '
-                '"${defaultSourceDirectories[1]}" directories';
-      }
-
-      dataError(
-          "Your package must have $defaults,\n"
-              "or you must specify the source directories.");
-    }
-  }
-
-  /// Converts a list of [directoryNames] to a sentence.
-  ///
-  /// After the list of directories, [singularVerb] will be used if there is
-  /// only one directory and [pluralVerb] will be used if there are more than
-  /// one. Then [suffix] is added to the end of the sentence, and, finally, a
-  /// period is added.
-  String _directorySentence(Iterable<String> directoryNames,
-      String singularVerb, String pluralVerb, String suffix) {
-    var directories =
-        pluralize('Directory', directoryNames.length, plural: 'Directories');
-    var names = toSentence(directoryNames.map((dir) => '"$dir"'));
-    var verb =
-        pluralize(singularVerb, directoryNames.length, plural: pluralVerb);
-
-    var result = "$directories $names $verb";
-    if (suffix != null) result += " $suffix";
-    result += ".";
-
-    return result;
-  }
-}