tools/engine_tool/lib/src/gn.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 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as p;

 import 'environment.dart';
 import 'label.dart';
 import 'typed_json.dart';

 /// An interface to the [GN](https://gn.googlesource.com/gn) build system.
 ///
 /// See also: <https://gn.googlesource.com/gn/+/main/docs/reference.md>.
 interface class Gn {
   /// Create a new GN interface using the given [environment].
   ///
   /// A GN binary must exist in `{engine.srcDir}/flutter/third_party/gn/gn`[^1].
   ///
   /// [^1]: On Windows, the binary is named `gn.exe`.
   const Gn.fromEnvironment(this._environment);

   final Environment _environment;

   String get _gnPath {
     return p.join(
       _environment.engine.srcDir.path,
       'flutter',
       'third_party',
       'gn',
       _environment.platform.isWindows ? 'gn.exe' : 'gn',
     );
   }

   /// Returns a list of build targets that match the given [pattern].
   ///
   /// This is equivalent to running:
   /// ```sh
   /// gn desc {outDir} {labelOrPattern}
   /// ```
   ///
   /// The [outDir] is the output directory of the build, e.g. `out/Release`.
   ///
   /// See also: <https://gn.googlesource.com/gn/+/main/docs/reference.md#cmd_desc>.
   Future<List<BuildTarget>> desc(
     String outDir,
     TargetPattern pattern,
   ) async {
     final command = [
       _gnPath,
       'desc',
       '--format=json',
       outDir,
       pattern.toGnPattern(),
     ];
     final process = await _environment.processRunner.runProcess(
       command,
       workingDirectory: _environment.engine.srcDir,
       failOk: true,
     );
     if (process.exitCode != 0) {
       // If the error was in the format:
       // "The input testing/scenario_app:scenario_app matches no targets, configs or files."
       //
       // Then report a nicer error, versus a fatal error.
       final stdout = process.stdout;
       if (stdout.contains('matches no targets, configs or files')) {
         final gnPattern = pattern.toGnPattern();
         if (!gnPattern.startsWith('//flutter')) {
           _environment.logger.warning(
             'No targets matched the pattern `$gnPattern`.'
             'Did you mean `//flutter/$gnPattern`?',
           );
         } else {
           _environment.logger.warning(
             'No targets matched the pattern `${pattern.toGnPattern()}`',
           );
         }
         return [];
       }

       _environment.logger.fatal(
         'Failed to run `${command.join(' ')}` (exit code ${process.exitCode})'
         '\n\n'
         'STDOUT:\n${process.stdout}\n'
         'STDERR:\n${process.stderr}\n',
       );
     }

     final JsonObject result;
     try {
       result = JsonObject.parse(process.stdout);
     } on FormatException catch (e) {
       _environment.logger.fatal(
         'Failed to parse JSON output from `gn desc`:\n$e\n${process.stdout}',
       );
     }

     return result
         .asMap()
         .entries
         .map((entry) {
           final label = entry.key;
           final properties = entry.value;
           if (properties is! Map<String, Object?>) {
             return null;
           }
           final target = BuildTarget._fromJson(
             label,
             JsonObject(properties),
           );
           if (target == null) {
             _environment.logger.warning(
               'Unknown target type for $label: type=${properties['type']}',
             );
             return null;
           }
           return target;
         })
         .whereType<BuildTarget>()
         .toList();
   }
 }

 /// Information about a build target.
 @immutable
 sealed class BuildTarget {
   const BuildTarget({
     required this.label,
     required this.testOnly,
   });

   factory BuildTarget._parseFromAction(
     String label, {
     required bool testOnly,
     required JsonObject json,
   }) {
     final metadata = json.objectOrNull('metadata');
     if (metadata != null) {
       final actionTypes = metadata.stringListOrNull('action_type');
       if (actionTypes != null && actionTypes.contains('dart_test')) {
         final String executable;
         final outputs = json.stringListOrNull('outputs');
         if (outputs == null || outputs.isEmpty) {
           throw StateError('Expected at least one output for $label');
         }

         // Remove the leading // from the path.
         executable = outputs.first.substring(2);
         return ExecutableBuildTarget(
           label: Label.parseGn(label),
           testOnly: testOnly,
           executable: executable,
         );
       }
     }
     return ActionBuildTarget(
       label: Label.parseGn(label),
       testOnly: testOnly,
     );
   }

   /// Returns a build target from JSON originating from `gn desc --format=json`.
   ///
   /// If the JSON is not a supported build target, returns `null`.
   static BuildTarget? _fromJson(String label, JsonObject json) {
     final (
       String type,
       bool testOnly,
     ) = json.map((json) => (
           json.string('type'),
           json.boolean('testonly'),
         ));
     return switch (type) {
       'executable' => ExecutableBuildTarget(
           label: Label.parseGn(label),
           testOnly: testOnly,
           // Remove the leading // from the path.
           executable: json.stringList('outputs').first.substring(2),
         ),
       'shared_library' || 'static_library' => LibraryBuildTarget(
           label: Label.parseGn(label),
           testOnly: testOnly,
         ),
       'action' => BuildTarget._parseFromAction(
           label,
           testOnly: testOnly,
           json: json,
         ),
       'group' => GroupBuildTarget(
           label: Label.parseGn(label),
           testOnly: testOnly,
           deps: json.stringList('deps').map(Label.parseGn).toList(),
         ),
       _ => null,
     };
   }

   /// Build target label, e.g. `//flutter/fml:fml_unittests`.
   final Label label;

   /// Whether a target is only used for testing.
   final bool testOnly;

   @mustBeOverridden
   @override
   bool operator ==(Object other);

   @mustBeOverridden
   @override
   int get hashCode;

   @mustBeOverridden
   @override
   String toString();
 }

 /// A build target that performs some [action][].
 ///
 /// [action]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_action
 final class ActionBuildTarget extends BuildTarget {
   /// Construct an action build target.
   const ActionBuildTarget({
     required super.label,
     required super.testOnly,
   });

   @override
   bool operator ==(Object other) {
     return other is LibraryBuildTarget &&
         label == other.label &&
         testOnly == other.testOnly;
   }

   @override
   int get hashCode => Object.hash(label, testOnly);

   @override
   String toString() => 'ActionBuildTarget($label, testOnly=$testOnly)';
 }

 /// A build target that produces a [shared library][] or [static library][].
 ///
 /// [shared library]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_shared_library
 /// [static library]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_static_library
 final class LibraryBuildTarget extends BuildTarget {
   /// Construct a library build target.
   const LibraryBuildTarget({
     required super.label,
     required super.testOnly,
   });

   @override
   bool operator ==(Object other) {
     return other is LibraryBuildTarget &&
         label == other.label &&
         testOnly == other.testOnly;
   }

   @override
   int get hashCode => Object.hash(label, testOnly);

   @override
   String toString() => 'LibraryBuildTarget($label, testOnly=$testOnly)';
 }

 /// A build target that produces an [executable][] program.
 ///
 /// [executable]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_executable
 final class ExecutableBuildTarget extends BuildTarget {
   /// Construct an executable build target.
   const ExecutableBuildTarget({
     required super.label,
     required super.testOnly,
     required this.executable,
   });

   /// The path to the executable program.
   final String executable;

   @override
   bool operator ==(Object other) {
     return other is ExecutableBuildTarget &&
         label == other.label &&
         testOnly == other.testOnly &&
         executable == other.executable;
   }

   @override
   int get hashCode => Object.hash(label, testOnly, executable);

   @override
   String toString() =>
       'ExecutableBuildTarget($label, testOnly=$testOnly, executable=$executable)';
 }

 /// A build target that [group]s a meta-target of other build targets.
 ///
 /// [group]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_group
 final class GroupBuildTarget extends BuildTarget {
   /// Construct a group build target.
   const GroupBuildTarget({
     required super.label,
     required super.testOnly,
     required this.deps,
   });

   /// The list of dependencies for this group target.
   final List<Label> deps;

   @override
   bool operator ==(Object other) {
     if (other is! GroupBuildTarget) {
       return false;
     }
     if (label != other.label || testOnly != other.testOnly) {
       return false;
     }
     return const ListEquality<Object>().equals(deps, other.deps);
   }

   @override
   int get hashCode => Object.hash(label, testOnly, Object.hashAll(deps));

   @override
   String toString() =>
       'GroupBuildTarget($label, testOnly=$testOnly, deps=$deps)';
 }
	// 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 'package:collection/collection.dart';
	import 'package:meta/meta.dart';
	import 'package:path/path.dart' as p;

	import 'environment.dart';
	import 'label.dart';
	import 'typed_json.dart';

	/// An interface to the [GN](https://gn.googlesource.com/gn) build system.
	///
	/// See also: <https://gn.googlesource.com/gn/+/main/docs/reference.md>.
	interface class Gn {
	/// Create a new GN interface using the given [environment].
	///
	/// A GN binary must exist in `{engine.srcDir}/flutter/third_party/gn/gn`[^1].
	///
	/// [^1]: On Windows, the binary is named `gn.exe`.
	const Gn.fromEnvironment(this._environment);

	final Environment _environment;

	String get _gnPath {
	return p.join(
	_environment.engine.srcDir.path,
	'flutter',
	'third_party',
	'gn',
	_environment.platform.isWindows ? 'gn.exe' : 'gn',
	);
	}

	/// Returns a list of build targets that match the given [pattern].
	///
	/// This is equivalent to running:
	/// ```sh
	/// gn desc {outDir} {labelOrPattern}
	/// ```
	///
	/// The [outDir] is the output directory of the build, e.g. `out/Release`.
	///
	/// See also: <https://gn.googlesource.com/gn/+/main/docs/reference.md#cmd_desc>.
	Future<List<BuildTarget>> desc(
	String outDir,
	TargetPattern pattern,
	) async {
	final command = [
	_gnPath,
	'desc',
	'--format=json',
	outDir,
	pattern.toGnPattern(),
	];
	final process = await _environment.processRunner.runProcess(
	command,
	workingDirectory: _environment.engine.srcDir,
	failOk: true,
	);
	if (process.exitCode != 0) {
	// If the error was in the format:
	// "The input testing/scenario_app:scenario_app matches no targets, configs or files."
	//
	// Then report a nicer error, versus a fatal error.
	final stdout = process.stdout;
	if (stdout.contains('matches no targets, configs or files')) {
	final gnPattern = pattern.toGnPattern();
	if (!gnPattern.startsWith('//flutter')) {
	_environment.logger.warning(
	'No targets matched the pattern `$gnPattern`.'
	'Did you mean `//flutter/$gnPattern`?',
	);
	} else {
	_environment.logger.warning(
	'No targets matched the pattern `${pattern.toGnPattern()}`',
	);
	}
	return [];
	}

	_environment.logger.fatal(
	'Failed to run `${command.join(' ')}` (exit code ${process.exitCode})'
	'\n\n'
	'STDOUT:\n${process.stdout}\n'
	'STDERR:\n${process.stderr}\n',
	);
	}

	final JsonObject result;
	try {
	result = JsonObject.parse(process.stdout);
	} on FormatException catch (e) {
	_environment.logger.fatal(
	'Failed to parse JSON output from `gn desc`:\n$e\n${process.stdout}',
	);
	}

	return result
	.asMap()
	.entries
	.map((entry) {
	final label = entry.key;
	final properties = entry.value;
	if (properties is! Map<String, Object?>) {
	return null;
	}
	final target = BuildTarget._fromJson(
	label,
	JsonObject(properties),
	);
	if (target == null) {
	_environment.logger.warning(
	'Unknown target type for $label: type=${properties['type']}',
	);
	return null;
	}
	return target;
	})
	.whereType<BuildTarget>()
	.toList();
	}
	}

	/// Information about a build target.
	@immutable
	sealed class BuildTarget {
	const BuildTarget({
	required this.label,
	required this.testOnly,
	});

	factory BuildTarget._parseFromAction(
	String label, {
	required bool testOnly,
	required JsonObject json,
	}) {
	final metadata = json.objectOrNull('metadata');
	if (metadata != null) {
	final actionTypes = metadata.stringListOrNull('action_type');
	if (actionTypes != null && actionTypes.contains('dart_test')) {
	final String executable;
	final outputs = json.stringListOrNull('outputs');
	if (outputs == null \|\| outputs.isEmpty) {
	throw StateError('Expected at least one output for $label');
	}

	// Remove the leading // from the path.
	executable = outputs.first.substring(2);
	return ExecutableBuildTarget(
	label: Label.parseGn(label),
	testOnly: testOnly,
	executable: executable,
	);
	}
	}
	return ActionBuildTarget(
	label: Label.parseGn(label),
	testOnly: testOnly,
	);
	}

	/// Returns a build target from JSON originating from `gn desc --format=json`.
	///
	/// If the JSON is not a supported build target, returns `null`.
	static BuildTarget? _fromJson(String label, JsonObject json) {
	final (
	String type,
	bool testOnly,
	) = json.map((json) => (
	json.string('type'),
	json.boolean('testonly'),
	));
	return switch (type) {
	'executable' => ExecutableBuildTarget(
	label: Label.parseGn(label),
	testOnly: testOnly,
	// Remove the leading // from the path.
	executable: json.stringList('outputs').first.substring(2),
	),
	'shared_library' \|\| 'static_library' => LibraryBuildTarget(
	label: Label.parseGn(label),
	testOnly: testOnly,
	),
	'action' => BuildTarget._parseFromAction(
	label,
	testOnly: testOnly,
	json: json,
	),
	'group' => GroupBuildTarget(
	label: Label.parseGn(label),
	testOnly: testOnly,
	deps: json.stringList('deps').map(Label.parseGn).toList(),
	),
	_ => null,
	};
	}

	/// Build target label, e.g. `//flutter/fml:fml_unittests`.
	final Label label;

	/// Whether a target is only used for testing.
	final bool testOnly;

	@mustBeOverridden
	@override
	bool operator ==(Object other);

	@mustBeOverridden
	@override
	int get hashCode;

	@mustBeOverridden
	@override
	String toString();
	}

	/// A build target that performs some [action][].
	///
	/// [action]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_action
	final class ActionBuildTarget extends BuildTarget {
	/// Construct an action build target.
	const ActionBuildTarget({
	required super.label,
	required super.testOnly,
	});

	@override
	bool operator ==(Object other) {
	return other is LibraryBuildTarget &&
	label == other.label &&
	testOnly == other.testOnly;
	}

	@override
	int get hashCode => Object.hash(label, testOnly);

	@override
	String toString() => 'ActionBuildTarget($label, testOnly=$testOnly)';
	}

	/// A build target that produces a [shared library][] or [static library][].
	///
	/// [shared library]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_shared_library
	/// [static library]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_static_library
	final class LibraryBuildTarget extends BuildTarget {
	/// Construct a library build target.
	const LibraryBuildTarget({
	required super.label,
	required super.testOnly,
	});

	@override
	bool operator ==(Object other) {
	return other is LibraryBuildTarget &&
	label == other.label &&
	testOnly == other.testOnly;
	}

	@override
	int get hashCode => Object.hash(label, testOnly);

	@override
	String toString() => 'LibraryBuildTarget($label, testOnly=$testOnly)';
	}

	/// A build target that produces an [executable][] program.
	///
	/// [executable]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_executable
	final class ExecutableBuildTarget extends BuildTarget {
	/// Construct an executable build target.
	const ExecutableBuildTarget({
	required super.label,
	required super.testOnly,
	required this.executable,
	});

	/// The path to the executable program.
	final String executable;

	@override
	bool operator ==(Object other) {
	return other is ExecutableBuildTarget &&
	label == other.label &&
	testOnly == other.testOnly &&
	executable == other.executable;
	}

	@override
	int get hashCode => Object.hash(label, testOnly, executable);

	@override
	String toString() =>
	'ExecutableBuildTarget($label, testOnly=$testOnly, executable=$executable)';
	}

	/// A build target that [group]s a meta-target of other build targets.
	///
	/// [group]: https://gn.googlesource.com/gn/+/main/docs/reference.md#func_group
	final class GroupBuildTarget extends BuildTarget {
	/// Construct a group build target.
	const GroupBuildTarget({
	required super.label,
	required super.testOnly,
	required this.deps,
	});

	/// The list of dependencies for this group target.
	final List<Label> deps;

	@override
	bool operator ==(Object other) {
	if (other is! GroupBuildTarget) {
	return false;
	}
	if (label != other.label \|\| testOnly != other.testOnly) {
	return false;
	}
	return const ListEquality<Object>().equals(deps, other.deps);
	}

	@override
	int get hashCode => Object.hash(label, testOnly, Object.hashAll(deps));

	@override
	String toString() =>
	'GroupBuildTarget($label, testOnly=$testOnly, deps=$deps)';
	}