Intial support for unifying command-line handling

pkg/analyzer/lib/src/command_line/arguments.dart

+// Copyright (c) 2016, 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.command_line.arguments;
+
+import 'dart:collection';
+
+import 'package:analyzer/file_system/file_system.dart';
+import 'package:analyzer/src/context/builder.dart';
+import 'package:analyzer/src/dart/sdk/sdk.dart';
+import 'package:analyzer/src/generated/engine.dart';
+import 'package:analyzer/src/generated/sdk.dart';
+import 'package:args/args.dart';
+import 'package:path/path.dart';
+
+const String analysisOptionsFileOption = 'options';
+const String defineVariableOption = 'D';
+const String enableInitializingFormalAccessFlag = 'initializing-formal-access';
+const String enableStrictCallChecksFlag = 'enable-strict-call-checks';
+const String enableSuperInMixinFlag = 'supermixin';
+const String ignoreUnrecognizedFlagsFlag = 'ignore_unrecognized_flags';
+const String noImplicitCastsFlag = 'no-implicit-casts';
+const String noImplicitDynamicFlag = 'no-implicit-dynamic';
+const String packageRootOption = 'package-root';
+const String packagesOption = 'packages';
+const String sdkPathOption = 'dart-sdk';
+const String sdkSummaryPathOption = 'dart-sdk-summary';
+const String strongModeFlag = 'strong';
+
+/**
+ * Use the given [resourceProvider], [contentCache] and command-line [args] to
+ * create a context builder.
+ */
+ContextBuilderOptions createContextBuilderOptions(ArgResults args) {
+  ContextBuilderOptions builderOptions = new ContextBuilderOptions();
+  //
+  // File locations.
+  //
+  builderOptions.dartSdkSummaryPath = args[sdkSummaryPathOption];
+  builderOptions.defaultAnalysisOptionsFilePath =
+      args[analysisOptionsFileOption];
+  builderOptions.defaultPackageFilePath = args[packagesOption];
+  builderOptions.defaultPackagesDirectoryPath = args[packageRootOption];
+  //
+  // Analysis options.
+  //
+  AnalysisOptionsImpl defaultOptions = new AnalysisOptionsImpl();
+  defaultOptions.enableInitializingFormalAccess =
+      args[enableInitializingFormalAccessFlag];
+  defaultOptions.enableStrictCallChecks = args[enableStrictCallChecksFlag];
+  defaultOptions.enableSuperMixins = args[enableSuperInMixinFlag];
+  defaultOptions.implicitCasts = !args[noImplicitCastsFlag];
+  defaultOptions.implicitDynamic = !args[noImplicitDynamicFlag];
+  defaultOptions.strongMode = args[strongModeFlag];
+  builderOptions.defaultOptions = defaultOptions;
+  //
+  // Declared variables.
+  //
+  Map<String, String> declaredVariables = <String, String>{};
+  List<String> variables = args[defineVariableOption] as List<String>;
+  for (String variable in variables) {
+    int index = variable.indexOf('=');
+    if (index < 0) {
+      // TODO (brianwilkerson) Decide the semantics we want in this case.
+      // The VM prints "No value given to -D option", then tries to load '-Dfoo'
+      // as a file and dies. Unless there was nothing after the '-D', in which
+      // case it prints the warning and ignores the option.
+    } else {
+      String name = variable.substring(0, index);
+      if (name.isNotEmpty) {
+        // TODO (brianwilkerson) Decide the semantics we want in the case where
+        // there is no name. If there is no name, the VM tries to load a file
+        // named '-D' and dies.
+        declaredVariables[name] = variable.substring(index + 1);
+      }
+    }
+  }
+  builderOptions.declaredVariables = declaredVariables;
+
+  return builderOptions;
+}
+
+/**
+ * Use the given [resourceProvider] and command-line [args] to create a Dart SDK
+ * manager. The manager will use summary information if [useSummaries] is `true`
+ * and if the summary information exists.
+ */
+DartSdkManager createDartSdkManager(
+    ResourceProvider resourceProvider, bool useSummaries, ArgResults args) {
+  String sdkPath = args[sdkPathOption];
+
+  bool canUseSummaries = useSummaries &&
+      args.rest.every((String sourcePath) {
+        sourcePath = context.absolute(sourcePath);
+        sourcePath = context.normalize(sourcePath);
+        return !context.isWithin(sdkPath, sourcePath);
+      });
+  return new DartSdkManager(
+      sdkPath ?? FolderBasedDartSdk.defaultSdkDirectory(resourceProvider),
+      canUseSummaries);
+}
+
+/**
+ * Add the standard flags and options to the given [parser]. The standard flags
+ * are those that are typically used to control the way in which the code is
+ * analyzed.
+ */
+void defineAnalysisArguments(ArgParser parser) {
+  parser.addOption(defineVariableOption,
+      abbr: 'D',
+      allowMultiple: true,
+      help: 'Define environment variables. For example, "-Dfoo=bar" defines an '
+          'environment variable named "foo" whose value is "bar".');
+  parser.addOption(sdkPathOption, help: 'The path to the Dart SDK.');
+  parser.addOption(sdkSummaryPathOption,
+      help: 'The path to the Dart SDK summary file.', hide: true);
+  parser.addOption(analysisOptionsFileOption,
+      help: 'Path to an analysis options file.');
+  parser.addOption(packagesOption,
+      help: 'The path to the package resolution configuration file, which '
+          'supplies a mapping of package names to paths. This option cannot be '
+          'used with --package-root.');
+  parser.addOption(packageRootOption,
+      abbr: 'p',
+      help: 'The path to a package root directory (deprecated). This option '
+          'cannot be used with --packages.');
+
+  parser.addFlag(strongModeFlag,
+      help: 'Enable strong static checks (https://goo.gl/DqcBsw)');
+  parser.addFlag(noImplicitCastsFlag,
+      negatable: false,
+      help: 'Disable implicit casts in strong mode (https://goo.gl/cTLz40)');
+  parser.addFlag(noImplicitDynamicFlag,
+      negatable: false,
+      help: 'Disable implicit dynamic (https://goo.gl/m0UgXD)');
+  //
+  // Hidden flags and options.
+  //
+//  parser.addFlag(enableNullAwareOperatorsFlag, // 'enable-null-aware-operators'
+//      help: 'Enable support for null-aware operators (DEP 9).',
+//      defaultsTo: false,
+//      negatable: false,
+//      hide: true);
+  parser.addFlag(enableStrictCallChecksFlag,
+      help: 'Fix issue 21938.',
+      defaultsTo: false,
+      negatable: false,
+      hide: true);
+  parser.addFlag(enableInitializingFormalAccessFlag,
+      help:
+          'Enable support for allowing access to field formal parameters in a '
+          'constructor\'s initializer list',
+      defaultsTo: false,
+      negatable: false,
+      hide: true);
+  parser.addFlag(enableSuperInMixinFlag,
+      help: 'Relax restrictions on mixins (DEP 34).',
+      defaultsTo: false,
+      negatable: false,
+      hide: true);
+//  parser.addFlag('enable_type_checks',
+//      help: 'Check types in constant evaluation.',
+//      defaultsTo: false,
+//      negatable: false,
+//      hide: true);
+}
+
+/**
+ * Return a list of command-line arguments containing all of the given [args]
+ * that are defined by the given [parser]. An argument is considered to be
+ * defined by the parser if
+ * - it starts with '--' and the rest of the argument (minus any value
+ *   introduced by '=') is the name of a known option,
+ * - it starts with '-' and the rest of the argument (minus any value
+ *   introduced by '=') is the name of a known abbreviation, or
+ * - it starts with something other than '--' or '-'.
+ *
+ * This function allows command-line tools to implement the
+ * '--ignore_unrecognized_flags' option.
+ */
+List<String> filterUnknownArguments(List<String> args, ArgParser parser) {
+  Set<String> knownOptions = new HashSet<String>();
+  Set<String> knownAbbreviations = new HashSet<String>();
+  parser.options.forEach((String name, Option option) {
+    knownOptions.add(name);
+    String abbreviation = option.abbreviation;
+    if (abbreviation != null) {
+      knownAbbreviations.add(abbreviation);
+    }
+  });
+  String optionName(int prefixLength, String argument) {
+    int equalsOffset = argument.lastIndexOf('=');
+    if (equalsOffset < 0) {
+      return argument.substring(prefixLength);
+    }
+    return argument.substring(prefixLength, equalsOffset);
+  }
+
+  List<String> filtered = <String>[];
+  for (int i = 0; i < args.length; i++) {
+    String argument = args[i];
+    if (argument.startsWith('--') && argument.length > 2) {
+      if (knownOptions.contains(optionName(2, argument))) {
+        filtered.add(argument);
+      }
+    } else if (argument.startsWith('-') && argument.length > 1) {
+      if (knownAbbreviations.contains(optionName(1, argument))) {
+        filtered.add(argument);
+      }
+    } else {
+      filtered.add(argument);
+    }
+  }
+  return filtered;
+}
+
+/**
+ * Use the given [parser] to parse the given command-line [args], and return the
+ * result.
+ */
+ArgResults parse(
+    ResourceProvider provider, ArgParser parser, List<String> args) {
+  args = preprocessArgs(provider, args);
+  if (args.contains('--$ignoreUnrecognizedFlagsFlag')) {
+    args = filterUnknownArguments(args, parser);
+  }
+  return parser.parse(args);
+}
+
+/**
+ * Preprocess the given list of command line [args] by checking whether the real
+ * arguments are in a file (Bazel worker mode).
+ */
+List<String> preprocessArgs(ResourceProvider provider, List<String> args) {
+  if (args.isEmpty) {
+    return args;
+  }
+  String lastArg = args.last;
+  if (lastArg.startsWith('@')) {
+    File argsFile = provider.getFile(lastArg.substring(1));
+    try {
+      List<String> newArgs = args.sublist(0, args.length - 1).toList();
+      newArgs.addAll(argsFile
+          .readAsStringSync()
+          .replaceAll('\r\n', '\n')
+          .replaceAll('\r', '\n')
+          .split('\n')
+          .where((String line) => line.isNotEmpty));
+      return newArgs;
+    } on FileSystemException {
+      // Don't modify args if the file does not exist or cannot be read.
+    }
+  }
+  return args;
+}