Allow engine variants other than "host_debug" to be clang-tidy linted

ci/lint.sh

@@ -41,6 +41,5 @@ cd "$SCRIPT_DIR"
 "$DART" \
   --disable-dart-dev \
   "$SRC_DIR/flutter/tools/clang_tidy/bin/main.dart" \
-  --compile-commands="$COMPILE_COMMANDS" \
-  --repo="$SRC_DIR/flutter" \
+  --src-dir="$SRC_DIR" \
   "$@"

tools/clang_tidy/README.md

@@ -1,9 +1,15 @@
 # clang_tidy
 
-This is a Dart program/library that runs clang_tidy over modified files. It
-takes two mandatory arguments that point at a compile_commands.json command
-and the root of the Flutter engine repo:
+This is a Dart program/library that runs clang_tidy over modified files in the Flutter engine repo.
+
+By default the linter runs on the repo files changed contained in `src/out/host_debug/compile_commands.json` command.
+To check files other than in `host_debug` use `--target-variant android_debug_unopt`,
+`--target-variant ios_debug_sim_unopt`, etc.
+
+Alternatively, use `--compile-commands` to specify a path to a `compile_commands.json` file.
 
 ```
-$ bin/main.dart --compile-commands <compile_commands.json-path> --repo <path-to-repo>
+$ bin/main.dart --target-variant <engine-variant>
+$ bin/main.dart --compile-commands <compile_commands.json-path>
+$ bin/main.dart --help
 ```

tools/clang_tidy/bin/main.dart

@@ -7,8 +7,8 @@
 // Runs clang-tidy on files with changes.
 //
 // Basic Usage:
-// dart bin/main.dart --compile-commands <path to compile_commands.json> \
-//                    --repo <path to git repository> \
+// dart bin/main.dart --compile-commands <path to compile_commands.json>
+// dart bin/main.dart --target-variant <engine-variant>
 //
 // User environment variable FLUTTER_LINT_ALL to run on all files.
 

tools/clang_tidy/lib/clang_tidy.dart

@@ -45,7 +45,6 @@ class ClangTidy {
   /// will otherwise go to stderr.
   ClangTidy({
     required io.File buildCommandsPath,
-    required io.Directory repoPath,
     String checksArg = '',
     bool lintAll = false,
     bool fix = false,
@@ -54,7 +53,6 @@ class ClangTidy {
   }) :
     options = Options(
       buildCommandsPath: buildCommandsPath,
-      repoPath: repoPath,
       checksArg: checksArg,
       lintAll: lintAll,
       fix: fix,
@@ -229,16 +227,8 @@ class ClangTidy {
       if (job.result.exitCode == 0) {
         continue;
       }
-      if (job.exception != null) {
-        _errSink.writeln(
-          '\n❗ A clang-tidy job failed to run, aborting:\n${job.exception}',
-        );
-        result = 1;
-        break;
-      } else {
-        _errSink.writeln('❌ Failures for ${job.name}:');
-        _errSink.writeln(job.result.stdout);
-      }
+      _errSink.writeln('❌ Failures for ${job.name}:');
+      _errSink.writeln(job.result.stdout);
       result = 1;
     }
     return result;

tools/clang_tidy/lib/src/command.dart

@@ -134,8 +134,10 @@ class Command {
       filePath,
       if (checks != null)
         checks,
-      if (fix)
+      if (fix) ...<String>[
         '--fix',
+        '--format-style=file',
+      ],
       '--',
     ];
     args.addAll(tidyArgs.split(' '));

tools/clang_tidy/lib/src/options.dart

@@ -5,14 +5,17 @@
 import 'dart:io' as io show Directory, File, Platform, stderr;
 
 import 'package:args/args.dart';
+import 'package:path/path.dart' as path;
+
+// Path to root of the flutter/engine repository containing this script.
+final String _engineRoot = path.dirname(path.dirname(path.dirname(path.dirname(path.fromUri(io.Platform.script)))));
 
 /// A class for organizing the options to the Engine linter, and the files
 /// that it operates on.
 class Options {
   /// Builds an instance of [Options] from the arguments.
   Options({
     required this.buildCommandsPath,
-    required this.repoPath,
     this.help = false,
     this.verbose = false,
     this.checksArg = '',
@@ -30,7 +33,6 @@ class Options {
     return Options(
       errorMessage: message,
       buildCommandsPath: io.File('none'),
-      repoPath: io.Directory('none'),
       errSink: errSink,
     );
   }
@@ -41,21 +43,20 @@ class Options {
     return Options(
       help: true,
       buildCommandsPath: io.File('none'),
-      repoPath: io.Directory('none'),
       errSink: errSink,
     );
   }
 
   /// Builds an [Options] instance with an [ArgResults] instance.
   factory Options._fromArgResults(
     ArgResults options, {
+    required io.File buildCommandsPath,
     StringSink? errSink,
   }) {
     return Options(
       help: options['help'] as bool,
       verbose: options['verbose'] as bool,
-      buildCommandsPath: io.File(options['compile-commands'] as String),
-      repoPath: io.Directory(options['repo'] as String),
+      buildCommandsPath: buildCommandsPath,
       checksArg: options.wasParsed('checks') ? options['checks'] as String : '',
       lintAll: io.Platform.environment['FLUTTER_LINT_ALL'] != null ||
                options['lint-all'] as bool,
@@ -70,7 +71,17 @@ class Options {
     StringSink? errSink,
   }) {
     final ArgResults argResults = _argParser.parse(arguments);
-    final String? message = _checkArguments(argResults);
+
+    String? buildCommandsPath = argResults['compile-commands'] as String?;
+    // path/to/engine/src/out/variant/compile_commands.json
+    buildCommandsPath ??= path.join(
+      argResults['src-dir'] as String,
+      'out',
+      argResults['target-variant'] as String,
+      'compile_commands.json',
+    );
+    final io.File buildCommands = io.File(buildCommandsPath);
+    final String? message = _checkArguments(argResults, buildCommands);
     if (message != null) {
       return Options._error(message, errSink: errSink);
     }
@@ -79,14 +90,17 @@ class Options {
     }
     return Options._fromArgResults(
       argResults,
+      buildCommandsPath: buildCommands,
       errSink: errSink,
     );
   }
 
   static final ArgParser _argParser = ArgParser()
     ..addFlag(
       'help',
+      abbr: 'h',
       help: 'Print help.',
+      negatable: false,
     )
     ..addFlag(
       'lint-all',
@@ -103,14 +117,25 @@ class Options {
       help: 'Print verbose output.',
       defaultsTo: false,
     )
-    ..addOption(
-      'repo',
-      help: 'Use the given path as the repo path',
-    )
     ..addOption(
       'compile-commands',
       help: 'Use the given path as the source of compile_commands.json. This '
-            'file is created by running tools/gn',
+            'file is created by running "tools/gn". Cannot be used with --target-variant '
+            'or --src-dir.',
+    )
+    ..addOption(
+      'target-variant',
+      aliases: <String>['variant'],
+      help: 'The engine variant directory containing compile_commands.json '
+            'created by running "tools/gn". Cannot be used with --compile-commands.',
+      valueHelp: 'host_debug|android_debug_unopt|ios_debug|ios_debug_sim_unopt',
+      defaultsTo: 'host_debug',
+    )
+    ..addOption(
+      'src-dir',
+      help: 'Path to the engine src directory. Cannot be used with --compile-commands.',
+      valueHelp: 'path/to/engine/src',
+      defaultsTo: path.dirname(_engineRoot),
     )
     ..addOption(
       'checks',
@@ -129,7 +154,7 @@ class Options {
   final io.File buildCommandsPath;
 
   /// The root of the flutter/engine repository.
-  final io.Directory repoPath;
+  final io.Directory repoPath = io.Directory(_engineRoot);
 
   /// Arguments to plumb through to clang-tidy formatted as a command line
   /// argument.
@@ -156,35 +181,30 @@ class Options {
       _errSink.writeln(message);
     }
     _errSink.writeln(
-      'Usage: bin/main.dart [--help] [--lint-all] [--fix] [--verbose] [--diff-branch]',
+      'Usage: bin/main.dart [--help] [--lint-all] [--fix] [--verbose] [--diff-branch] [--target-variant variant] [--src-dir path/to/engine/src]',
     );
     _errSink.writeln(_argParser.usage);
   }
 
   /// Command line argument validation.
-  static String? _checkArguments(ArgResults argResults) {
+  static String? _checkArguments(ArgResults argResults, io.File buildCommandsPath) {
     if (argResults.wasParsed('help')) {
       return null;
     }
 
-    if (!argResults.wasParsed('compile-commands')) {
-      return 'ERROR: The --compile-commands argument is required.';
+    final bool compileCommandsParsed = argResults.wasParsed('compile-commands');
+    if (compileCommandsParsed && argResults.wasParsed('target-variant')) {
+      return 'ERROR: --compile-commands option cannot be used with --target-variant.';
     }
 
-    if (!argResults.wasParsed('repo')) {
-      return 'ERROR: The --repo argument is required.';
+    if (compileCommandsParsed && argResults.wasParsed('src-dir')) {
+      return 'ERROR: --compile-commands option cannot be used with --src-dir.';
     }
 
-    final io.File buildCommandsPath = io.File(argResults['compile-commands'] as String);
     if (!buildCommandsPath.existsSync()) {
       return "ERROR: Build commands path ${buildCommandsPath.absolute.path} doesn't exist.";
     }
 
-    final io.Directory repoPath = io.Directory(argResults['repo'] as String);
-    if (!repoPath.existsSync()) {
-      return "ERROR: Repo path ${repoPath.absolute.path} doesn't exist.";
-    }
-
     return null;
   }
 }