tools/clang_tidy/lib/clang_tidy.dart - mirrors/engine - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:convert' show LineSplitter, jsonDecode;
 import 'dart:io' as io show File, ProcessSignal, stderr, stdout;

 import 'package:engine_repo_tools/engine_repo_tools.dart';
 import 'package:git_repo_tools/git_repo_tools.dart';
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;
 import 'package:process/process.dart';
 import 'package:process_runner/process_runner.dart';

 import 'src/command.dart';
 import 'src/lint_target.dart';
 import 'src/options.dart';

 const String _linterOutputHeader = '''
 ┌──────────────────────────┐
 │ Engine Clang Tidy Linter │
 └──────────────────────────┘
 The following errors have been reported by the Engine Clang Tidy Linter.  For
 more information on addressing these issues please see:
 https://github.com/flutter/flutter/wiki/Engine-Clang-Tidy-Linter
 ''';

 class _ComputeJobsResult {
   _ComputeJobsResult(this.jobs, this.sawMalformed);

   final List<WorkerJob> jobs;
   final bool sawMalformed;
 }

 enum _SetStatus {
   Intersection,
   Difference,
 }

 class _SetStatusCommand {
   _SetStatusCommand(this.setStatus, this.command);
   final _SetStatus setStatus;
   final Command command;
 }

 /// A class that runs clang-tidy on all or only the changed files in a git
 /// repo.
 class ClangTidy {
   /// Builds an instance of [ClangTidy] using a repo's [buildCommandPath].
   ///
   /// ## Required
   ///
   /// - [buildCommandsPath] is the path to the build_commands.json file.
   ///
   /// ## Optional
   ///
   /// - [checksArg] are specific checks for clang-tidy to do.
   ///
   ///   If omitted, checks will be determined by the `.clang-tidy` file in the
   ///   repo.
   ///
   /// - [lintTarget] is what files to lint.
   ///
   /// ## Optional (Test Overrides)
   ///
   /// _Most usages of this class will not need to override the following, which
   /// are primarily used for testing (i.e. to avoid real interaction with I/O)._
   ///
   /// - [outSink] when provided is the destination for normal log messages.
   ///
   ///   If omitted, [io.stdout] will be used.
   ///
   /// - [errSink] when provided is the destination for error messages.
   ///
   ///   If omitted, [io.stderr] will be used.
   ///
   /// - [processManager] when provided is delegated to for running processes.
   ///
   ///   If omitted, [LocalProcessManager] will be used.
   ClangTidy({
     required io.File buildCommandsPath,
     String checksArg = '',
     LintTarget lintTarget = const LintChanged(),
     bool fix = false,
     StringSink? outSink,
     StringSink? errSink,
     ProcessManager processManager = const LocalProcessManager(),
   }) :
     options = Options(
       buildCommandsPath: buildCommandsPath,
       checksArg: checksArg,
       lintTarget: lintTarget,
       fix: fix,
       errSink: errSink,
     ),
     _outSink = outSink ?? io.stdout,
     _errSink = errSink ?? io.stderr,
     _processManager = processManager,
     _engine = null;

   /// Builds an instance of [ClangTidy] from a command line.
   ClangTidy.fromCommandLine(
     List<String> args, {
     Engine? engine,
     StringSink? outSink,
     StringSink? errSink,
     ProcessManager processManager = const LocalProcessManager(),
   }) :
     options = Options.fromCommandLine(args, errSink: errSink, engine: engine),
     _outSink = outSink ?? io.stdout,
     _errSink = errSink ?? io.stderr,
     _processManager = processManager,
     _engine = engine;

   /// The [Options] that specify how this [ClangTidy] operates.
   final Options options;
   final StringSink _outSink;
   final StringSink _errSink;
   final ProcessManager _processManager;
   final Engine? _engine;

   late final DateTime _startTime;

   /// Runs clang-tidy on the repo as specified by the [Options].
   Future<int> run() async {
     _startTime = DateTime.now();

     if (options.help) {
       options.printUsage(engine: _engine);
       return 0;
     }

     if (options.errorMessage != null) {
       options.printUsage(message: options.errorMessage, engine: _engine);
       return 1;
     }

     _outSink.writeln(_linterOutputHeader);

     final List<io.File> filesOfInterest = await computeFilesOfInterest();

     if (options.verbose) {
       _outSink.writeln('Checking lint in repo at ${options.repoPath.path}.');
       if (options.checksArg.isNotEmpty) {
         _outSink.writeln('Checking for specific checks: ${options.checks}.');
       }
       final int changedFilesCount = filesOfInterest.length;
       switch (options.lintTarget) {
         case LintAll():
           _outSink.writeln('Checking all $changedFilesCount files in the repo.');
         case LintChanged():
           _outSink.writeln(
             'Checking $changedFilesCount files that have changed since the '
             'last commit.',
           );
         case LintHead():
           _outSink.writeln(
             'Checking $changedFilesCount files that have changed compared to '
             'HEAD.',
           );
         case LintRegex(:final String regex):
           _outSink.writeln(
             'Checking $changedFilesCount files that match the regex "$regex".',
           );
       }
     }

     final List<Object?> buildCommandsData = jsonDecode(
       options.buildCommandsPath.readAsStringSync(),
     ) as List<Object?>;
     final List<List<Object?>> shardBuildCommandsData = options
         .shardCommandsPaths
         .map((io.File file) =>
             jsonDecode(file.readAsStringSync()) as List<Object?>)
         .toList();
     final List<Command> changedFileBuildCommands = await getLintCommandsForFiles(
       buildCommandsData,
       filesOfInterest,
       shardBuildCommandsData,
       options.shardId,
     );

     if (changedFileBuildCommands.isEmpty) {
       _outSink.writeln(
         'No changed files that have build commands associated with them were '
         'found.',
       );
       return 0;
     }

     if (options.verbose) {
       _outSink.writeln(
         'Found ${changedFileBuildCommands.length} files that have build '
         'commands associated with them and can be lint checked.',
       );
     }

     final _ComputeJobsResult computeJobsResult = await _computeJobs(
       changedFileBuildCommands,
       options,
     );
     final int computeResult = computeJobsResult.sawMalformed ? 1 : 0;
     final List<WorkerJob> jobs = computeJobsResult.jobs;

     final int runResult = await _runJobs(jobs);
     _outSink.writeln('\n');
     if (computeResult + runResult == 0) {
       _outSink.writeln('No lint problems found.');
     } else {
       _errSink.writeln('Lint problems found.');
     }

     return computeResult + runResult > 0 ? 1 : 0;
   }

   /// The files with local modifications or all/a subset of all files.
   ///
   /// See [LintTarget] for more information.
   @visibleForTesting
   Future<List<io.File>> computeFilesOfInterest() async {
     switch (options.lintTarget) {
       case LintAll():
         return options.repoPath
           .listSync(recursive: true)
           .whereType<io.File>()
           .toList();
       case LintRegex(:final String regex):
         final RegExp pattern = RegExp(regex);
         return options.repoPath
           .listSync(recursive: true)
           .whereType<io.File>()
           .where((io.File file) => pattern.hasMatch(file.path))
           .toList();
       case LintChanged():
         final GitRepo repo = GitRepo.fromRoot(
           options.repoPath,
           processManager: _processManager,
           verbose: options.verbose,
         );
         return repo.changedFiles;
       case LintHead():
         final GitRepo repo = GitRepo.fromRoot(
           options.repoPath,
           processManager: _processManager,
           verbose: options.verbose,
         );
         return repo.changedFilesAtHead;
     }
   }

   /// Returns f(n) = value(n * [shardCount] + [id]).
   Iterable<T> _takeShard<T>(Iterable<T> values, int id, int shardCount) sync* {
     int count = 0;
     for (final T val in values) {
       if (count % shardCount == id) {
         yield val;
       }
       count++;
     }
   }

   /// This returns a `_SetStatusCommand` for each [Command] in [items].
   /// `Intersection` if the Command shows up in [items] and its filePath in all
   /// [filePathSets], otherwise `Difference`.
   Iterable<_SetStatusCommand> _calcIntersection(
       Iterable<Command> items, Iterable<Set<String>> filePathSets) sync* {
     bool allSetsContain(Command command) {
       for (final Set<String> filePathSet in filePathSets) {
         if (!filePathSet.contains(command.filePath)) {
           return false;
         }
       }
       return true;
     }
     for (final Command command in items) {
       if (allSetsContain(command)) {
         yield _SetStatusCommand(_SetStatus.Intersection, command);
       } else {
         yield _SetStatusCommand(_SetStatus.Difference, command);
       }
     }
   }

   /// Given a build commands json file's contents in [buildCommandsData], and
   /// the [files] with local changes, compute the lint commands to run.  If
   /// build commands are supplied in [sharedBuildCommandsData] the intersection
   /// of those build commands will be calculated and distributed across
   /// instances via the [shardId].
   @visibleForTesting
   Future<List<Command>> getLintCommandsForFiles(
     List<Object?> buildCommandsData,
     List<io.File> files,
     List<List<Object?>> sharedBuildCommandsData,
     int? shardId,
   ) {
     final List<Command> totalCommands = <Command>[];
     if (sharedBuildCommandsData.isNotEmpty) {
       final List<Command> buildCommands = <Command>[
         for (final Object? data in buildCommandsData)
           Command.fromMap((data as Map<String, Object?>?)!)
       ];
       final List<Set<String>> shardFilePaths = <Set<String>>[
         for (final List<Object?> list in sharedBuildCommandsData)
           <String>{
             for (final Object? data in list)
               Command.fromMap((data as Map<String, Object?>?)!).filePath
           }
       ];
       final Iterable<_SetStatusCommand> intersectionResults =
           _calcIntersection(buildCommands, shardFilePaths);
       for (final _SetStatusCommand result in intersectionResults) {
         if (result.setStatus == _SetStatus.Difference) {
           totalCommands.add(result.command);
         }
       }
       final List<Command> intersection = <Command>[
         for (final _SetStatusCommand result in intersectionResults)
           if (result.setStatus == _SetStatus.Intersection) result.command
       ];
       // Make sure to sort results so the sharding scheme is guaranteed to work
       // since we are not sure if there is a defined order in the json file.
       intersection
           .sort((Command x, Command y) => x.filePath.compareTo(y.filePath));
       totalCommands.addAll(
           _takeShard(intersection, shardId!, 1 + sharedBuildCommandsData.length));
     } else {
       totalCommands.addAll(<Command>[
         for (final Object? data in buildCommandsData)
           Command.fromMap((data as Map<String, Object?>?)!)
       ]);
     }
     return () async {
       final List<Command> result = <Command>[];
       for (final Command command in totalCommands) {
         final LintAction lintAction = await command.lintAction;
         // Short-circuit the expensive containsAny call for the many third_party files.
         if (lintAction != LintAction.skipThirdParty &&
             command.containsAny(files)) {
           result.add(command);
         }
       }
       return result;
     }();
   }

   Future<_ComputeJobsResult> _computeJobs(
     List<Command> commands,
     Options options,
   ) async {
     bool sawMalformed = false;
     final List<WorkerJob> jobs = <WorkerJob>[];
     for (final Command command in commands) {
       final String relativePath = path.relative(
         command.filePath,
         from: options.repoPath.parent.path,
       );
       final LintAction action = await command.lintAction;
       switch (action) {
         case LintAction.skipNoLint:
           _outSink.writeln('🔷 ignoring $relativePath (FLUTTER_NOLINT)');
         case LintAction.failMalformedNoLint:
           _errSink.writeln('❌ malformed opt-out $relativePath');
           _errSink.writeln(
             '   Required format: // FLUTTER_NOLINT: $issueUrlPrefix/ISSUE_ID',
           );
           sawMalformed = true;
         case LintAction.lint:
           _outSink.writeln('🔶 linting $relativePath');
           jobs.add(command.createLintJob(options));
         case LintAction.skipThirdParty:
           _outSink.writeln('🔷 ignoring $relativePath (third_party)');
         case LintAction.skipMissing:
           _outSink.writeln('🔷 ignoring $relativePath (missing)');
       }
     }
     return _ComputeJobsResult(jobs, sawMalformed);
   }

   static Iterable<String> _trimGenerator(String output) sync* {
     const LineSplitter splitter = LineSplitter();
     final List<String> lines = splitter.convert(output);
     bool isPrintingError = false;
     for (final String line in lines) {
       if (line.contains(': error:') || line.contains(': warning:')) {
         isPrintingError = true;
         yield line;
       } else if (line == ':') {
           isPrintingError = false;
       } else if (isPrintingError) {
         yield line;
       }
     }
   }

   /// Visible for testing.
   /// Function for trimming raw clang-tidy output.
   @visibleForTesting
   static String trimOutput(String output) => _trimGenerator(output).join('\n');

   Future<int> _runJobs(List<WorkerJob> jobs) async {
     int result = 0;
     int ignoredFailures = 0;
     final Set<String> pendingJobs = <String>{for (final WorkerJob job in jobs) job.name};

     void reporter(int totalJobs, int completed, int inProgress, int pending, int failed) {
       return _logWithTimestamp(ProcessPool.defaultReportToString(
         totalJobs, completed, inProgress, pending, failed - ignoredFailures));
     }

     final ProcessPool pool = ProcessPool(
       printReport: reporter,
       processRunner: ProcessRunner(processManager: _processManager),
     );
     await for (final WorkerJob job in pool.startWorkers(jobs)) {
       pendingJobs.remove(job.name);
       if (pendingJobs.isNotEmpty && pendingJobs.length <= 3) {
         final List<String> sortedJobs = pendingJobs.toList()..sort();
         _logWithTimestamp('Still running: $sortedJobs');
       }
       if (job.result.exitCode == 0) {
         if (options.enableCheckProfile) {
           // stderr is lazily evaluated, so force it to be evaluated here.
           final String stderr = job.result.stderr;
           _errSink.writeln('Results of --enable-check-profile for ${job.name}:');
           _errSink.writeln(stderr);
         }
         continue;
       }
       // Recent versions of clang-tidy are segfaulting when processing some
       // engine source files.
       // (see https://github.com/flutter/flutter/issues/143178)
       // TODO(jsimmons): remove this when the issue is fixed in Clang.
       if (job.result.exitCode == -io.ProcessSignal.sigsegv.signalNumber) {
         _errSink.writeln('❗ Crash when running clang-tidy for ${job.name}.  Skipping this file.');
         ignoredFailures++;
         continue;
       }
       _errSink.writeln('❌ Failures for ${job.name}:');
       if (!job.printOutput) {
         final Exception? exception = job.exception;
         if (exception != null) {
           _errSink.writeln(trimOutput(exception.toString()));
         } else {
           _errSink.writeln(trimOutput(job.result.stdout));
         }
       }
       result = 1;
     }
     return result;
   }

   void _logWithTimestamp(String message) {
     final Duration elapsedTime = DateTime.now().difference(_startTime);
     final String seconds = (elapsedTime.inSeconds % 60).toString().padLeft(2, '0');
     _outSink.writeln('[${elapsedTime.inMinutes}:$seconds] $message');
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:convert' show LineSplitter, jsonDecode;
	import 'dart:io' as io show File, ProcessSignal, stderr, stdout;

	import 'package:engine_repo_tools/engine_repo_tools.dart';
	import 'package:git_repo_tools/git_repo_tools.dart';
	import 'package:meta/meta.dart';
	import 'package:path/path.dart' as path;
	import 'package:process/process.dart';
	import 'package:process_runner/process_runner.dart';

	import 'src/command.dart';
	import 'src/lint_target.dart';
	import 'src/options.dart';

	const String _linterOutputHeader = '''
	┌──────────────────────────┐
	│ Engine Clang Tidy Linter │
	└──────────────────────────┘
	The following errors have been reported by the Engine Clang Tidy Linter. For
	more information on addressing these issues please see:
	https://github.com/flutter/flutter/wiki/Engine-Clang-Tidy-Linter
	''';

	class _ComputeJobsResult {
	_ComputeJobsResult(this.jobs, this.sawMalformed);

	final List<WorkerJob> jobs;
	final bool sawMalformed;
	}

	enum _SetStatus {
	Intersection,
	Difference,
	}

	class _SetStatusCommand {
	_SetStatusCommand(this.setStatus, this.command);
	final _SetStatus setStatus;
	final Command command;
	}

	/// A class that runs clang-tidy on all or only the changed files in a git
	/// repo.
	class ClangTidy {
	/// Builds an instance of [ClangTidy] using a repo's [buildCommandPath].
	///
	/// ## Required
	///
	/// - [buildCommandsPath] is the path to the build_commands.json file.
	///
	/// ## Optional
	///
	/// - [checksArg] are specific checks for clang-tidy to do.
	///
	/// If omitted, checks will be determined by the `.clang-tidy` file in the
	/// repo.
	///
	/// - [lintTarget] is what files to lint.
	///
	/// ## Optional (Test Overrides)
	///
	/// _Most usages of this class will not need to override the following, which
	/// are primarily used for testing (i.e. to avoid real interaction with I/O)._
	///
	/// - [outSink] when provided is the destination for normal log messages.
	///
	/// If omitted, [io.stdout] will be used.
	///
	/// - [errSink] when provided is the destination for error messages.
	///
	/// If omitted, [io.stderr] will be used.
	///
	/// - [processManager] when provided is delegated to for running processes.
	///
	/// If omitted, [LocalProcessManager] will be used.
	ClangTidy({
	required io.File buildCommandsPath,
	String checksArg = '',
	LintTarget lintTarget = const LintChanged(),
	bool fix = false,
	StringSink? outSink,
	StringSink? errSink,
	ProcessManager processManager = const LocalProcessManager(),
	}) :
	options = Options(
	buildCommandsPath: buildCommandsPath,
	checksArg: checksArg,
	lintTarget: lintTarget,
	fix: fix,
	errSink: errSink,
	),
	_outSink = outSink ?? io.stdout,
	_errSink = errSink ?? io.stderr,
	_processManager = processManager,
	_engine = null;

	/// Builds an instance of [ClangTidy] from a command line.
	ClangTidy.fromCommandLine(
	List<String> args, {
	Engine? engine,
	StringSink? outSink,
	StringSink? errSink,
	ProcessManager processManager = const LocalProcessManager(),
	}) :
	options = Options.fromCommandLine(args, errSink: errSink, engine: engine),
	_outSink = outSink ?? io.stdout,
	_errSink = errSink ?? io.stderr,
	_processManager = processManager,
	_engine = engine;

	/// The [Options] that specify how this [ClangTidy] operates.
	final Options options;
	final StringSink _outSink;
	final StringSink _errSink;
	final ProcessManager _processManager;
	final Engine? _engine;

	late final DateTime _startTime;

	/// Runs clang-tidy on the repo as specified by the [Options].
	Future<int> run() async {
	_startTime = DateTime.now();

	if (options.help) {
	options.printUsage(engine: _engine);
	return 0;
	}

	if (options.errorMessage != null) {
	options.printUsage(message: options.errorMessage, engine: _engine);
	return 1;
	}

	_outSink.writeln(_linterOutputHeader);

	final List<io.File> filesOfInterest = await computeFilesOfInterest();

	if (options.verbose) {
	_outSink.writeln('Checking lint in repo at ${options.repoPath.path}.');
	if (options.checksArg.isNotEmpty) {
	_outSink.writeln('Checking for specific checks: ${options.checks}.');
	}
	final int changedFilesCount = filesOfInterest.length;
	switch (options.lintTarget) {
	case LintAll():
	_outSink.writeln('Checking all $changedFilesCount files in the repo.');
	case LintChanged():
	_outSink.writeln(
	'Checking $changedFilesCount files that have changed since the '
	'last commit.',
	);
	case LintHead():
	_outSink.writeln(
	'Checking $changedFilesCount files that have changed compared to '
	'HEAD.',
	);
	case LintRegex(:final String regex):
	_outSink.writeln(
	'Checking $changedFilesCount files that match the regex "$regex".',
	);
	}
	}

	final List<Object?> buildCommandsData = jsonDecode(
	options.buildCommandsPath.readAsStringSync(),
	) as List<Object?>;
	final List<List<Object?>> shardBuildCommandsData = options
	.shardCommandsPaths
	.map((io.File file) =>
	jsonDecode(file.readAsStringSync()) as List<Object?>)
	.toList();
	final List<Command> changedFileBuildCommands = await getLintCommandsForFiles(
	buildCommandsData,
	filesOfInterest,
	shardBuildCommandsData,
	options.shardId,
	);

	if (changedFileBuildCommands.isEmpty) {
	_outSink.writeln(
	'No changed files that have build commands associated with them were '
	'found.',
	);
	return 0;
	}

	if (options.verbose) {
	_outSink.writeln(
	'Found ${changedFileBuildCommands.length} files that have build '
	'commands associated with them and can be lint checked.',
	);
	}

	final _ComputeJobsResult computeJobsResult = await _computeJobs(
	changedFileBuildCommands,
	options,
	);
	final int computeResult = computeJobsResult.sawMalformed ? 1 : 0;
	final List<WorkerJob> jobs = computeJobsResult.jobs;

	final int runResult = await _runJobs(jobs);
	_outSink.writeln('\n');
	if (computeResult + runResult == 0) {
	_outSink.writeln('No lint problems found.');
	} else {
	_errSink.writeln('Lint problems found.');
	}

	return computeResult + runResult > 0 ? 1 : 0;
	}

	/// The files with local modifications or all/a subset of all files.
	///
	/// See [LintTarget] for more information.
	@visibleForTesting
	Future<List<io.File>> computeFilesOfInterest() async {
	switch (options.lintTarget) {
	case LintAll():
	return options.repoPath
	.listSync(recursive: true)
	.whereType<io.File>()
	.toList();
	case LintRegex(:final String regex):
	final RegExp pattern = RegExp(regex);
	return options.repoPath
	.listSync(recursive: true)
	.whereType<io.File>()
	.where((io.File file) => pattern.hasMatch(file.path))
	.toList();
	case LintChanged():
	final GitRepo repo = GitRepo.fromRoot(
	options.repoPath,
	processManager: _processManager,
	verbose: options.verbose,
	);
	return repo.changedFiles;
	case LintHead():
	final GitRepo repo = GitRepo.fromRoot(
	options.repoPath,
	processManager: _processManager,
	verbose: options.verbose,
	);
	return repo.changedFilesAtHead;
	}
	}

	/// Returns f(n) = value(n * [shardCount] + [id]).
	Iterable<T> _takeShard<T>(Iterable<T> values, int id, int shardCount) sync* {
	int count = 0;
	for (final T val in values) {
	if (count % shardCount == id) {
	yield val;
	}
	count++;
	}
	}

	/// This returns a `_SetStatusCommand` for each [Command] in [items].
	/// `Intersection` if the Command shows up in [items] and its filePath in all
	/// [filePathSets], otherwise `Difference`.
	Iterable<_SetStatusCommand> _calcIntersection(
	Iterable<Command> items, Iterable<Set<String>> filePathSets) sync* {
	bool allSetsContain(Command command) {
	for (final Set<String> filePathSet in filePathSets) {
	if (!filePathSet.contains(command.filePath)) {
	return false;
	}
	}
	return true;
	}
	for (final Command command in items) {
	if (allSetsContain(command)) {
	yield _SetStatusCommand(_SetStatus.Intersection, command);
	} else {
	yield _SetStatusCommand(_SetStatus.Difference, command);
	}
	}
	}

	/// Given a build commands json file's contents in [buildCommandsData], and
	/// the [files] with local changes, compute the lint commands to run. If
	/// build commands are supplied in [sharedBuildCommandsData] the intersection
	/// of those build commands will be calculated and distributed across
	/// instances via the [shardId].
	@visibleForTesting
	Future<List<Command>> getLintCommandsForFiles(
	List<Object?> buildCommandsData,
	List<io.File> files,
	List<List<Object?>> sharedBuildCommandsData,
	int? shardId,
	) {
	final List<Command> totalCommands = <Command>[];
	if (sharedBuildCommandsData.isNotEmpty) {
	final List<Command> buildCommands = <Command>[
	for (final Object? data in buildCommandsData)
	Command.fromMap((data as Map<String, Object?>?)!)
	];
	final List<Set<String>> shardFilePaths = <Set<String>>[
	for (final List<Object?> list in sharedBuildCommandsData)
	<String>{
	for (final Object? data in list)
	Command.fromMap((data as Map<String, Object?>?)!).filePath
	}
	];
	final Iterable<_SetStatusCommand> intersectionResults =
	_calcIntersection(buildCommands, shardFilePaths);
	for (final _SetStatusCommand result in intersectionResults) {
	if (result.setStatus == _SetStatus.Difference) {
	totalCommands.add(result.command);
	}
	}
	final List<Command> intersection = <Command>[
	for (final _SetStatusCommand result in intersectionResults)
	if (result.setStatus == _SetStatus.Intersection) result.command
	];
	// Make sure to sort results so the sharding scheme is guaranteed to work
	// since we are not sure if there is a defined order in the json file.
	intersection
	.sort((Command x, Command y) => x.filePath.compareTo(y.filePath));
	totalCommands.addAll(
	_takeShard(intersection, shardId!, 1 + sharedBuildCommandsData.length));
	} else {
	totalCommands.addAll(<Command>[
	for (final Object? data in buildCommandsData)
	Command.fromMap((data as Map<String, Object?>?)!)
	]);
	}
	return () async {
	final List<Command> result = <Command>[];
	for (final Command command in totalCommands) {
	final LintAction lintAction = await command.lintAction;
	// Short-circuit the expensive containsAny call for the many third_party files.
	if (lintAction != LintAction.skipThirdParty &&
	command.containsAny(files)) {
	result.add(command);
	}
	}
	return result;
	}();
	}

	Future<_ComputeJobsResult> _computeJobs(
	List<Command> commands,
	Options options,
	) async {
	bool sawMalformed = false;
	final List<WorkerJob> jobs = <WorkerJob>[];
	for (final Command command in commands) {
	final String relativePath = path.relative(
	command.filePath,
	from: options.repoPath.parent.path,
	);
	final LintAction action = await command.lintAction;
	switch (action) {
	case LintAction.skipNoLint:
	_outSink.writeln('🔷 ignoring $relativePath (FLUTTER_NOLINT)');
	case LintAction.failMalformedNoLint:
	_errSink.writeln('❌ malformed opt-out $relativePath');
	_errSink.writeln(
	' Required format: // FLUTTER_NOLINT: $issueUrlPrefix/ISSUE_ID',
	);
	sawMalformed = true;
	case LintAction.lint:
	_outSink.writeln('🔶 linting $relativePath');
	jobs.add(command.createLintJob(options));
	case LintAction.skipThirdParty:
	_outSink.writeln('🔷 ignoring $relativePath (third_party)');
	case LintAction.skipMissing:
	_outSink.writeln('🔷 ignoring $relativePath (missing)');
	}
	}
	return _ComputeJobsResult(jobs, sawMalformed);
	}

	static Iterable<String> _trimGenerator(String output) sync* {
	const LineSplitter splitter = LineSplitter();
	final List<String> lines = splitter.convert(output);
	bool isPrintingError = false;
	for (final String line in lines) {
	if (line.contains(': error:') \|\| line.contains(': warning:')) {
	isPrintingError = true;
	yield line;
	} else if (line == ':') {
	isPrintingError = false;
	} else if (isPrintingError) {
	yield line;
	}
	}
	}

	/// Visible for testing.
	/// Function for trimming raw clang-tidy output.
	@visibleForTesting
	static String trimOutput(String output) => _trimGenerator(output).join('\n');

	Future<int> _runJobs(List<WorkerJob> jobs) async {
	int result = 0;
	int ignoredFailures = 0;
	final Set<String> pendingJobs = <String>{for (final WorkerJob job in jobs) job.name};

	void reporter(int totalJobs, int completed, int inProgress, int pending, int failed) {
	return _logWithTimestamp(ProcessPool.defaultReportToString(
	totalJobs, completed, inProgress, pending, failed - ignoredFailures));
	}

	final ProcessPool pool = ProcessPool(
	printReport: reporter,
	processRunner: ProcessRunner(processManager: _processManager),
	);
	await for (final WorkerJob job in pool.startWorkers(jobs)) {
	pendingJobs.remove(job.name);
	if (pendingJobs.isNotEmpty && pendingJobs.length <= 3) {
	final List<String> sortedJobs = pendingJobs.toList()..sort();
	_logWithTimestamp('Still running: $sortedJobs');
	}
	if (job.result.exitCode == 0) {
	if (options.enableCheckProfile) {
	// stderr is lazily evaluated, so force it to be evaluated here.
	final String stderr = job.result.stderr;
	_errSink.writeln('Results of --enable-check-profile for ${job.name}:');
	_errSink.writeln(stderr);
	}
	continue;
	}
	// Recent versions of clang-tidy are segfaulting when processing some
	// engine source files.
	// (see https://github.com/flutter/flutter/issues/143178)
	// TODO(jsimmons): remove this when the issue is fixed in Clang.
	if (job.result.exitCode == -io.ProcessSignal.sigsegv.signalNumber) {
	_errSink.writeln('❗ Crash when running clang-tidy for ${job.name}. Skipping this file.');
	ignoredFailures++;
	continue;
	}
	_errSink.writeln('❌ Failures for ${job.name}:');
	if (!job.printOutput) {
	final Exception? exception = job.exception;
	if (exception != null) {
	_errSink.writeln(trimOutput(exception.toString()));
	} else {
	_errSink.writeln(trimOutput(job.result.stdout));
	}
	}
	result = 1;
	}
	return result;
	}

	void _logWithTimestamp(String message) {
	final Duration elapsedTime = DateTime.now().difference(_startTime);
	final String seconds = (elapsedTime.inSeconds % 60).toString().padLeft(2, '0');
	_outSink.writeln('[${elapsedTime.inMinutes}:$seconds] $message');
	}
	}