packages/flutter_tools/lib/src/build_system/targets/ios.dart - external/github.com/flutter/flutter - Git at Google

 // Copyright 2014 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 '../../artifacts.dart';
 import '../../base/build.dart';
 import '../../base/common.dart';
 import '../../base/file_system.dart';
 import '../../base/io.dart';
 import '../../base/process.dart';
 import '../../build_info.dart';
 import '../../globals.dart' as globals hide fs, logger, processManager, artifacts;
 import '../../macos/xcode.dart';
 import '../../project.dart';
 import '../build_system.dart';
 import '../depfile.dart';
 import '../exceptions.dart';
 import 'assets.dart';
 import 'common.dart';
 import 'icon_tree_shaker.dart';

 /// Supports compiling a dart kernel file to an assembly file.
 ///
 /// If more than one iOS arch is provided, then this rule will
 /// produce a universal binary.
 abstract class AotAssemblyBase extends Target {
   const AotAssemblyBase();

   @override
   String get analyticsName => 'ios_aot';

   @override
   Future<void> build(Environment environment) async {
     final AOTSnapshotter snapshotter = AOTSnapshotter(
       reportTimings: false,
       fileSystem: environment.fileSystem,
       logger: environment.logger,
       xcode: globals.xcode,
       artifacts: environment.artifacts,
       processManager: environment.processManager,
     );
     final String buildOutputPath = environment.buildDir.path;
     if (environment.defines[kBuildMode] == null) {
       throw MissingDefineException(kBuildMode, 'aot_assembly');
     }
     if (environment.defines[kTargetPlatform] == null) {
       throw MissingDefineException(kTargetPlatform, 'aot_assembly');
     }
     final List<String> extraGenSnapshotOptions = decodeDartDefines(environment.defines, kExtraGenSnapshotOptions);
     final bool bitcode = environment.defines[kBitcodeFlag] == 'true';
     final BuildMode buildMode = getBuildModeForName(environment.defines[kBuildMode]);
     final TargetPlatform targetPlatform = getTargetPlatformForName(environment.defines[kTargetPlatform]);
     final String splitDebugInfo = environment.defines[kSplitDebugInfo];
     final bool dartObfuscation = environment.defines[kDartObfuscation] == 'true';
     final List<DarwinArch> darwinArchs = environment.defines[kIosArchs]
       ?.split(' ')
       ?.map(getIOSArchForName)
       ?.toList()
       ?? <DarwinArch>[DarwinArch.arm64];
     if (targetPlatform != TargetPlatform.ios) {
       throw Exception('aot_assembly is only supported for iOS applications.');
     }
     if (darwinArchs.contains(DarwinArch.x86_64)) {
       throw Exception(
         'release/profile builds are only supported for physical devices. '
         'attempted to build for $darwinArchs.'
       );
     }
     final String codeSizeDirectory = environment.defines[kCodeSizeDirectory];

     // If we're building multiple iOS archs the binaries need to be lipo'd
     // together.
     final List<Future<int>> pending = <Future<int>>[];
     for (final DarwinArch darwinArch in darwinArchs) {
       final List<String> archExtraGenSnapshotOptions = List<String>.of(extraGenSnapshotOptions);
       if (codeSizeDirectory != null) {
         final File codeSizeFile = environment.fileSystem
           .directory(codeSizeDirectory)
           .childFile('snapshot.${getNameForDarwinArch(darwinArch)}.json');
         final File precompilerTraceFile = environment.fileSystem
           .directory(codeSizeDirectory)
           .childFile('trace.${getNameForDarwinArch(darwinArch)}.json');
         archExtraGenSnapshotOptions.add('--write-v8-snapshot-profile-to=${codeSizeFile.path}');
         archExtraGenSnapshotOptions.add('--trace-precompiler-to=${precompilerTraceFile.path}');
       }
       pending.add(snapshotter.build(
         platform: targetPlatform,
         buildMode: buildMode,
         mainPath: environment.buildDir.childFile('app.dill').path,
         packagesPath: environment.projectDir.childFile('.packages').path,
         outputPath: environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(darwinArch)),
         darwinArch: darwinArch,
         bitcode: bitcode,
         quiet: true,
         splitDebugInfo: splitDebugInfo,
         dartObfuscation: dartObfuscation,
         extraGenSnapshotOptions: archExtraGenSnapshotOptions,
       ));
     }
     final List<int> results = await Future.wait(pending);
     if (results.any((int result) => result != 0)) {
       throw Exception('AOT snapshotter exited with code ${results.join()}');
     }
     final String resultPath = environment.fileSystem.path.join(environment.buildDir.path, 'App.framework', 'App');
     environment.fileSystem.directory(resultPath).parent.createSync(recursive: true);
     final ProcessResult result = await environment.processManager.run(<String>[
       'lipo',
       ...darwinArchs.map((DarwinArch iosArch) =>
           environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(iosArch), 'App.framework', 'App')),
       '-create',
       '-output',
       resultPath,
     ]);
     if (result.exitCode != 0) {
       throw Exception('lipo exited with code ${result.exitCode}.\n${result.stderr}');
     }
   }
 }

 /// Generate an assembly target from a dart kernel file in release mode.
 class AotAssemblyRelease extends AotAssemblyBase {
   const AotAssemblyRelease();

   @override
   String get name => 'aot_assembly_release';

   @override
   List<Source> get inputs => const <Source>[
     Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
     Source.pattern('{BUILD_DIR}/app.dill'),
     Source.pattern('{PROJECT_DIR}/.packages'),
     Source.artifact(Artifact.engineDartBinary),
     Source.artifact(Artifact.skyEnginePath),
     // TODO(jonahwilliams): cannot reference gen_snapshot with artifacts since
     // it resolves to a file (ios/gen_snapshot) that never exists. This was
     // split into gen_snapshot_arm64 and gen_snapshot_armv7.
     // Source.artifact(Artifact.genSnapshot,
     //   platform: TargetPlatform.ios,
     //   mode: BuildMode.release,
     // ),
   ];

   @override
   List<Source> get outputs => const <Source>[
     Source.pattern('{OUTPUT_DIR}/App.framework/App'),
   ];

   @override
   List<Target> get dependencies => const <Target>[
     KernelSnapshot(),
   ];
 }


 /// Generate an assembly target from a dart kernel file in profile mode.
 class AotAssemblyProfile extends AotAssemblyBase {
   const AotAssemblyProfile();

   @override
   String get name => 'aot_assembly_profile';

   @override
   List<Source> get inputs => const <Source>[
     Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
     Source.pattern('{BUILD_DIR}/app.dill'),
     Source.pattern('{PROJECT_DIR}/.packages'),
     Source.artifact(Artifact.engineDartBinary),
     Source.artifact(Artifact.skyEnginePath),
     // TODO(jonahwilliams): cannot reference gen_snapshot with artifacts since
     // it resolves to a file (ios/gen_snapshot) that never exists. This was
     // split into gen_snapshot_arm64 and gen_snapshot_armv7.
     // Source.artifact(Artifact.genSnapshot,
     //   platform: TargetPlatform.ios,
     //   mode: BuildMode.profile,
     // ),
   ];

   @override
   List<Source> get outputs => const <Source>[
     Source.pattern('{OUTPUT_DIR}/App.framework/App'),
   ];

   @override
   List<Target> get dependencies => const <Target>[
     KernelSnapshot(),
   ];
 }

 /// Create a trivial App.framework file for debug iOS builds.
 class DebugUniversalFramework extends Target {
   const DebugUniversalFramework();

   @override
   String get name => 'debug_universal_framework';

   @override
   List<Target> get dependencies => const <Target>[
     KernelSnapshot(),
   ];

   @override
   List<Source> get inputs => const <Source>[
      Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
   ];

   @override
   List<Source> get outputs => const <Source>[
     Source.pattern('{BUILD_DIR}/App.framework/App'),
   ];

   @override
   Future<void> build(Environment environment) async {
     // Generate a trivial App.framework.
     final Set<DarwinArch> iosArchs = environment.defines[kIosArchs]
       ?.split(' ')
       ?.map(getIOSArchForName)
       ?.toSet()
       ?? <DarwinArch>{DarwinArch.arm64};
     final File iphoneFile = environment.buildDir.childFile('iphone_framework');
     final File simulatorFile = environment.buildDir.childFile('simulator_framework');
     final File lipoOutputFile = environment.buildDir
       .childDirectory('App.framework')
       .childFile('App');
     lipoOutputFile.parent.createSync(recursive: true);
     final RunResult iphoneResult = await createStubAppFramework(
       iphoneFile,
       SdkType.iPhone,
       // Only include 32bit if it is contained in the active architectures.
       include32Bit: iosArchs.contains(DarwinArch.armv7)
     );
     final RunResult simulatorResult = await createStubAppFramework(
       simulatorFile,
       SdkType.iPhoneSimulator,
     );
     if (iphoneResult.exitCode != 0 || simulatorResult.exitCode != 0) {
       throw Exception('Failed to create App.framework.');
     }
     final List<String> lipoCommand = <String>[
       ...globals.xcode.xcrunCommand(),
       'lipo',
       '-create',
       iphoneFile.path,
       simulatorFile.path,
       '-output',
       lipoOutputFile.path,
     ];

     final RunResult lipoResult = await globals.processUtils.run(
       lipoCommand,
     );

     if (lipoResult.exitCode != 0) {
       throw Exception('Failed to create App.framework.');
     }
   }
 }

 /// The base class for all iOS bundle targets.
 ///
 /// This is responsible for setting up the basic App.framework structure, including:
 /// * Copying the app.dill/kernel_blob.bin from the build directory to assets (debug)
 /// * Copying the precompiled isolate/vm data from the engine (debug)
 /// * Copying the flutter assets to App.framework/flutter_assets
 /// * Copying either the stub or real App assembly file to App.framework/App
 abstract class IosAssetBundle extends Target {
   const IosAssetBundle();

   @override
   List<Target> get dependencies => const <Target>[
     KernelSnapshot(),
   ];

   @override
   List<Source> get inputs => const <Source>[
     Source.pattern('{BUILD_DIR}/App.framework/App'),
     Source.pattern('{PROJECT_DIR}/pubspec.yaml'),
     ...IconTreeShaker.inputs,
   ];

   @override
   List<Source> get outputs => const <Source>[
     Source.pattern('{OUTPUT_DIR}/App.framework/App'),
     Source.pattern('{OUTPUT_DIR}/App.framework/Info.plist')
   ];

   @override
   List<String> get depfiles => <String>[
     'flutter_assets.d',
   ];

   @override
   Future<void> build(Environment environment) async {
     if (environment.defines[kBuildMode] == null) {
       throw MissingDefineException(kBuildMode, name);
     }
     final BuildMode buildMode = getBuildModeForName(environment.defines[kBuildMode]);
     final Directory frameworkDirectory = environment.outputDir.childDirectory('App.framework');
     final Directory assetDirectory = frameworkDirectory.childDirectory('flutter_assets');
     frameworkDirectory.createSync(recursive: true);
     assetDirectory.createSync();

     // Only copy the prebuilt runtimes and kernel blob in debug mode.
     if (buildMode == BuildMode.debug) {
       // Copy the App.framework to the output directory.
       environment.buildDir
         .childDirectory('App.framework')
         .childFile('App')
         .copySync(frameworkDirectory.childFile('App').path);

       final String vmSnapshotData = environment.artifacts.getArtifactPath(Artifact.vmSnapshotData, mode: BuildMode.debug);
       final String isolateSnapshotData = environment.artifacts.getArtifactPath(Artifact.isolateSnapshotData, mode: BuildMode.debug);
       environment.buildDir.childFile('app.dill')
           .copySync(assetDirectory.childFile('kernel_blob.bin').path);
       environment.fileSystem.file(vmSnapshotData)
           .copySync(assetDirectory.childFile('vm_snapshot_data').path);
       environment.fileSystem.file(isolateSnapshotData)
           .copySync(assetDirectory.childFile('isolate_snapshot_data').path);
     } else {
       environment.buildDir.childDirectory('App.framework').childFile('App')
         .copySync(frameworkDirectory.childFile('App').path);
     }

     // Copy the assets.
     final Depfile assetDepfile = await copyAssets(
       environment,
       assetDirectory,
       targetPlatform: TargetPlatform.ios,
     );
     final DepfileService depfileService = DepfileService(
       fileSystem: environment.fileSystem,
       logger: environment.logger,
     );
     depfileService.writeToFile(
       assetDepfile,
       environment.buildDir.childFile('flutter_assets.d'),
     );


     // Copy the plist from either the project or module.
     // TODO(jonahwilliams): add plist to inputs
     final FlutterProject flutterProject = FlutterProject.fromDirectory(environment.projectDir);
     final Directory plistRoot = flutterProject.isModule
       ? flutterProject.ios.ephemeralDirectory
       : environment.projectDir.childDirectory('ios');
     plistRoot
       .childDirectory('Flutter')
       .childFile('AppFrameworkInfo.plist')
       .copySync(environment.outputDir
       .childDirectory('App.framework')
       .childFile('Info.plist').path);
   }
 }

 /// Build a debug iOS application bundle.
 class DebugIosApplicationBundle extends IosAssetBundle {
   const DebugIosApplicationBundle();

   @override
   String get name => 'debug_ios_bundle_flutter_assets';

   @override
   List<Source> get inputs => <Source>[
     const Source.artifact(Artifact.vmSnapshotData, mode: BuildMode.debug),
     const Source.artifact(Artifact.isolateSnapshotData, mode: BuildMode.debug),
     const Source.pattern('{BUILD_DIR}/app.dill'),
     ...super.inputs,
   ];

   @override
   List<Source> get outputs => <Source>[
     const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/vm_snapshot_data'),
     const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/isolate_snapshot_data'),
     const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/kernel_blob.bin'),
     ...super.outputs,
   ];

   @override
   List<Target> get dependencies => <Target>[
     const DebugUniversalFramework(),
     ...super.dependencies,
   ];
 }

 /// Build a profile iOS application bundle.
 class ProfileIosApplicationBundle extends IosAssetBundle {
   const ProfileIosApplicationBundle();

   @override
   String get name => 'profile_ios_bundle_flutter_assets';

   @override
   List<Target> get dependencies => const <Target>[
     AotAssemblyProfile(),
   ];
 }

 /// Build a release iOS application bundle.
 class ReleaseIosApplicationBundle extends IosAssetBundle {
   const ReleaseIosApplicationBundle();

   @override
   String get name => 'release_ios_bundle_flutter_assets';

   @override
   List<Target> get dependencies => const <Target>[
     AotAssemblyRelease(),
   ];
 }

 /// Create an App.framework for debug iOS targets.
 ///
 /// This framework needs to exist for the Xcode project to link/bundle,
 /// but it isn't actually executed. To generate something valid, we compile a trivial
 /// constant.
 Future<RunResult> createStubAppFramework(File outputFile, SdkType sdk, { bool include32Bit = true }) async {
   try {
     outputFile.createSync(recursive: true);
   } on Exception catch (e) {
     throwToolExit('Failed to create App.framework stub at ${outputFile.path}: $e');
   }

   final Directory tempDir = outputFile.fileSystem.systemTempDirectory
     .createTempSync('flutter_tools_stub_source.');
   try {
     final File stubSource = tempDir.childFile('debug_app.cc')
       ..writeAsStringSync(r'''
   static const int Moo = 88;
   ''');

     List<String> archFlags;
     if (sdk == SdkType.iPhone) {
       archFlags = <String>[
         if (include32Bit)
           ...<String>['-arch', getNameForDarwinArch(DarwinArch.armv7)],
         '-arch',
         getNameForDarwinArch(DarwinArch.arm64),
       ];
     } else {
       archFlags = <String>[
         '-arch',
         getNameForDarwinArch(DarwinArch.x86_64),
       ];
     }

     return await globals.xcode.clang(<String>[
       '-x',
       'c',
       ...archFlags,
       stubSource.path,
       '-dynamiclib',
       '-fembed-bitcode-marker',
       '-Xlinker', '-rpath', '-Xlinker', '@executable_path/Frameworks',
       '-Xlinker', '-rpath', '-Xlinker', '@loader_path/Frameworks',
       '-install_name', '@rpath/App.framework/App',
       '-isysroot', await globals.xcode.sdkLocation(sdk),
       '-o', outputFile.path,
     ]);
   } finally {
     try {
       tempDir.deleteSync(recursive: true);
     } on FileSystemException {
       // Best effort. Sometimes we can't delete things from system temp.
     } on Exception catch (e) {
       throwToolExit('Failed to create App.framework stub at ${outputFile.path}: $e');
     }
   }
 }
	// Copyright 2014 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 '../../artifacts.dart';
	import '../../base/build.dart';
	import '../../base/common.dart';
	import '../../base/file_system.dart';
	import '../../base/io.dart';
	import '../../base/process.dart';
	import '../../build_info.dart';
	import '../../globals.dart' as globals hide fs, logger, processManager, artifacts;
	import '../../macos/xcode.dart';
	import '../../project.dart';
	import '../build_system.dart';
	import '../depfile.dart';
	import '../exceptions.dart';
	import 'assets.dart';
	import 'common.dart';
	import 'icon_tree_shaker.dart';

	/// Supports compiling a dart kernel file to an assembly file.
	///
	/// If more than one iOS arch is provided, then this rule will
	/// produce a universal binary.
	abstract class AotAssemblyBase extends Target {
	const AotAssemblyBase();

	@override
	String get analyticsName => 'ios_aot';

	@override
	Future<void> build(Environment environment) async {
	final AOTSnapshotter snapshotter = AOTSnapshotter(
	reportTimings: false,
	fileSystem: environment.fileSystem,
	logger: environment.logger,
	xcode: globals.xcode,
	artifacts: environment.artifacts,
	processManager: environment.processManager,
	);
	final String buildOutputPath = environment.buildDir.path;
	if (environment.defines[kBuildMode] == null) {
	throw MissingDefineException(kBuildMode, 'aot_assembly');
	}
	if (environment.defines[kTargetPlatform] == null) {
	throw MissingDefineException(kTargetPlatform, 'aot_assembly');
	}
	final List<String> extraGenSnapshotOptions = decodeDartDefines(environment.defines, kExtraGenSnapshotOptions);
	final bool bitcode = environment.defines[kBitcodeFlag] == 'true';
	final BuildMode buildMode = getBuildModeForName(environment.defines[kBuildMode]);
	final TargetPlatform targetPlatform = getTargetPlatformForName(environment.defines[kTargetPlatform]);
	final String splitDebugInfo = environment.defines[kSplitDebugInfo];
	final bool dartObfuscation = environment.defines[kDartObfuscation] == 'true';
	final List<DarwinArch> darwinArchs = environment.defines[kIosArchs]
	?.split(' ')
	?.map(getIOSArchForName)
	?.toList()
	?? <DarwinArch>[DarwinArch.arm64];
	if (targetPlatform != TargetPlatform.ios) {
	throw Exception('aot_assembly is only supported for iOS applications.');
	}
	if (darwinArchs.contains(DarwinArch.x86_64)) {
	throw Exception(
	'release/profile builds are only supported for physical devices. '
	'attempted to build for $darwinArchs.'
	);
	}
	final String codeSizeDirectory = environment.defines[kCodeSizeDirectory];

	// If we're building multiple iOS archs the binaries need to be lipo'd
	// together.
	final List<Future<int>> pending = <Future<int>>[];
	for (final DarwinArch darwinArch in darwinArchs) {
	final List<String> archExtraGenSnapshotOptions = List<String>.of(extraGenSnapshotOptions);
	if (codeSizeDirectory != null) {
	final File codeSizeFile = environment.fileSystem
	.directory(codeSizeDirectory)
	.childFile('snapshot.${getNameForDarwinArch(darwinArch)}.json');
	final File precompilerTraceFile = environment.fileSystem
	.directory(codeSizeDirectory)
	.childFile('trace.${getNameForDarwinArch(darwinArch)}.json');
	archExtraGenSnapshotOptions.add('--write-v8-snapshot-profile-to=${codeSizeFile.path}');
	archExtraGenSnapshotOptions.add('--trace-precompiler-to=${precompilerTraceFile.path}');
	}
	pending.add(snapshotter.build(
	platform: targetPlatform,
	buildMode: buildMode,
	mainPath: environment.buildDir.childFile('app.dill').path,
	packagesPath: environment.projectDir.childFile('.packages').path,
	outputPath: environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(darwinArch)),
	darwinArch: darwinArch,
	bitcode: bitcode,
	quiet: true,
	splitDebugInfo: splitDebugInfo,
	dartObfuscation: dartObfuscation,
	extraGenSnapshotOptions: archExtraGenSnapshotOptions,
	));
	}
	final List<int> results = await Future.wait(pending);
	if (results.any((int result) => result != 0)) {
	throw Exception('AOT snapshotter exited with code ${results.join()}');
	}
	final String resultPath = environment.fileSystem.path.join(environment.buildDir.path, 'App.framework', 'App');
	environment.fileSystem.directory(resultPath).parent.createSync(recursive: true);
	final ProcessResult result = await environment.processManager.run(<String>[
	'lipo',
	...darwinArchs.map((DarwinArch iosArch) =>
	environment.fileSystem.path.join(buildOutputPath, getNameForDarwinArch(iosArch), 'App.framework', 'App')),
	'-create',
	'-output',
	resultPath,
	]);
	if (result.exitCode != 0) {
	throw Exception('lipo exited with code ${result.exitCode}.\n${result.stderr}');
	}
	}
	}

	/// Generate an assembly target from a dart kernel file in release mode.
	class AotAssemblyRelease extends AotAssemblyBase {
	const AotAssemblyRelease();

	@override
	String get name => 'aot_assembly_release';

	@override
	List<Source> get inputs => const <Source>[
	Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
	Source.pattern('{BUILD_DIR}/app.dill'),
	Source.pattern('{PROJECT_DIR}/.packages'),
	Source.artifact(Artifact.engineDartBinary),
	Source.artifact(Artifact.skyEnginePath),
	// TODO(jonahwilliams): cannot reference gen_snapshot with artifacts since
	// it resolves to a file (ios/gen_snapshot) that never exists. This was
	// split into gen_snapshot_arm64 and gen_snapshot_armv7.
	// Source.artifact(Artifact.genSnapshot,
	// platform: TargetPlatform.ios,
	// mode: BuildMode.release,
	// ),
	];

	@override
	List<Source> get outputs => const <Source>[
	Source.pattern('{OUTPUT_DIR}/App.framework/App'),
	];

	@override
	List<Target> get dependencies => const <Target>[
	KernelSnapshot(),
	];
	}


	/// Generate an assembly target from a dart kernel file in profile mode.
	class AotAssemblyProfile extends AotAssemblyBase {
	const AotAssemblyProfile();

	@override
	String get name => 'aot_assembly_profile';

	@override
	List<Source> get inputs => const <Source>[
	Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
	Source.pattern('{BUILD_DIR}/app.dill'),
	Source.pattern('{PROJECT_DIR}/.packages'),
	Source.artifact(Artifact.engineDartBinary),
	Source.artifact(Artifact.skyEnginePath),
	// TODO(jonahwilliams): cannot reference gen_snapshot with artifacts since
	// it resolves to a file (ios/gen_snapshot) that never exists. This was
	// split into gen_snapshot_arm64 and gen_snapshot_armv7.
	// Source.artifact(Artifact.genSnapshot,
	// platform: TargetPlatform.ios,
	// mode: BuildMode.profile,
	// ),
	];

	@override
	List<Source> get outputs => const <Source>[
	Source.pattern('{OUTPUT_DIR}/App.framework/App'),
	];

	@override
	List<Target> get dependencies => const <Target>[
	KernelSnapshot(),
	];
	}

	/// Create a trivial App.framework file for debug iOS builds.
	class DebugUniversalFramework extends Target {
	const DebugUniversalFramework();

	@override
	String get name => 'debug_universal_framework';

	@override
	List<Target> get dependencies => const <Target>[
	KernelSnapshot(),
	];

	@override
	List<Source> get inputs => const <Source>[
	Source.pattern('{FLUTTER_ROOT}/packages/flutter_tools/lib/src/build_system/targets/ios.dart'),
	];

	@override
	List<Source> get outputs => const <Source>[
	Source.pattern('{BUILD_DIR}/App.framework/App'),
	];

	@override
	Future<void> build(Environment environment) async {
	// Generate a trivial App.framework.
	final Set<DarwinArch> iosArchs = environment.defines[kIosArchs]
	?.split(' ')
	?.map(getIOSArchForName)
	?.toSet()
	?? <DarwinArch>{DarwinArch.arm64};
	final File iphoneFile = environment.buildDir.childFile('iphone_framework');
	final File simulatorFile = environment.buildDir.childFile('simulator_framework');
	final File lipoOutputFile = environment.buildDir
	.childDirectory('App.framework')
	.childFile('App');
	lipoOutputFile.parent.createSync(recursive: true);
	final RunResult iphoneResult = await createStubAppFramework(
	iphoneFile,
	SdkType.iPhone,
	// Only include 32bit if it is contained in the active architectures.
	include32Bit: iosArchs.contains(DarwinArch.armv7)
	);
	final RunResult simulatorResult = await createStubAppFramework(
	simulatorFile,
	SdkType.iPhoneSimulator,
	);
	if (iphoneResult.exitCode != 0 \|\| simulatorResult.exitCode != 0) {
	throw Exception('Failed to create App.framework.');
	}
	final List<String> lipoCommand = <String>[
	...globals.xcode.xcrunCommand(),
	'lipo',
	'-create',
	iphoneFile.path,
	simulatorFile.path,
	'-output',
	lipoOutputFile.path,
	];

	final RunResult lipoResult = await globals.processUtils.run(
	lipoCommand,
	);

	if (lipoResult.exitCode != 0) {
	throw Exception('Failed to create App.framework.');
	}
	}
	}

	/// The base class for all iOS bundle targets.
	///
	/// This is responsible for setting up the basic App.framework structure, including:
	/// * Copying the app.dill/kernel_blob.bin from the build directory to assets (debug)
	/// * Copying the precompiled isolate/vm data from the engine (debug)
	/// * Copying the flutter assets to App.framework/flutter_assets
	/// * Copying either the stub or real App assembly file to App.framework/App
	abstract class IosAssetBundle extends Target {
	const IosAssetBundle();

	@override
	List<Target> get dependencies => const <Target>[
	KernelSnapshot(),
	];

	@override
	List<Source> get inputs => const <Source>[
	Source.pattern('{BUILD_DIR}/App.framework/App'),
	Source.pattern('{PROJECT_DIR}/pubspec.yaml'),
	...IconTreeShaker.inputs,
	];

	@override
	List<Source> get outputs => const <Source>[
	Source.pattern('{OUTPUT_DIR}/App.framework/App'),
	Source.pattern('{OUTPUT_DIR}/App.framework/Info.plist')
	];

	@override
	List<String> get depfiles => <String>[
	'flutter_assets.d',
	];

	@override
	Future<void> build(Environment environment) async {
	if (environment.defines[kBuildMode] == null) {
	throw MissingDefineException(kBuildMode, name);
	}
	final BuildMode buildMode = getBuildModeForName(environment.defines[kBuildMode]);
	final Directory frameworkDirectory = environment.outputDir.childDirectory('App.framework');
	final Directory assetDirectory = frameworkDirectory.childDirectory('flutter_assets');
	frameworkDirectory.createSync(recursive: true);
	assetDirectory.createSync();

	// Only copy the prebuilt runtimes and kernel blob in debug mode.
	if (buildMode == BuildMode.debug) {
	// Copy the App.framework to the output directory.
	environment.buildDir
	.childDirectory('App.framework')
	.childFile('App')
	.copySync(frameworkDirectory.childFile('App').path);

	final String vmSnapshotData = environment.artifacts.getArtifactPath(Artifact.vmSnapshotData, mode: BuildMode.debug);
	final String isolateSnapshotData = environment.artifacts.getArtifactPath(Artifact.isolateSnapshotData, mode: BuildMode.debug);
	environment.buildDir.childFile('app.dill')
	.copySync(assetDirectory.childFile('kernel_blob.bin').path);
	environment.fileSystem.file(vmSnapshotData)
	.copySync(assetDirectory.childFile('vm_snapshot_data').path);
	environment.fileSystem.file(isolateSnapshotData)
	.copySync(assetDirectory.childFile('isolate_snapshot_data').path);
	} else {
	environment.buildDir.childDirectory('App.framework').childFile('App')
	.copySync(frameworkDirectory.childFile('App').path);
	}

	// Copy the assets.
	final Depfile assetDepfile = await copyAssets(
	environment,
	assetDirectory,
	targetPlatform: TargetPlatform.ios,
	);
	final DepfileService depfileService = DepfileService(
	fileSystem: environment.fileSystem,
	logger: environment.logger,
	);
	depfileService.writeToFile(
	assetDepfile,
	environment.buildDir.childFile('flutter_assets.d'),
	);


	// Copy the plist from either the project or module.
	// TODO(jonahwilliams): add plist to inputs
	final FlutterProject flutterProject = FlutterProject.fromDirectory(environment.projectDir);
	final Directory plistRoot = flutterProject.isModule
	? flutterProject.ios.ephemeralDirectory
	: environment.projectDir.childDirectory('ios');
	plistRoot
	.childDirectory('Flutter')
	.childFile('AppFrameworkInfo.plist')
	.copySync(environment.outputDir
	.childDirectory('App.framework')
	.childFile('Info.plist').path);
	}
	}

	/// Build a debug iOS application bundle.
	class DebugIosApplicationBundle extends IosAssetBundle {
	const DebugIosApplicationBundle();

	@override
	String get name => 'debug_ios_bundle_flutter_assets';

	@override
	List<Source> get inputs => <Source>[
	const Source.artifact(Artifact.vmSnapshotData, mode: BuildMode.debug),
	const Source.artifact(Artifact.isolateSnapshotData, mode: BuildMode.debug),
	const Source.pattern('{BUILD_DIR}/app.dill'),
	...super.inputs,
	];

	@override
	List<Source> get outputs => <Source>[
	const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/vm_snapshot_data'),
	const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/isolate_snapshot_data'),
	const Source.pattern('{OUTPUT_DIR}/App.framework/flutter_assets/kernel_blob.bin'),
	...super.outputs,
	];

	@override
	List<Target> get dependencies => <Target>[
	const DebugUniversalFramework(),
	...super.dependencies,
	];
	}

	/// Build a profile iOS application bundle.
	class ProfileIosApplicationBundle extends IosAssetBundle {
	const ProfileIosApplicationBundle();

	@override
	String get name => 'profile_ios_bundle_flutter_assets';

	@override
	List<Target> get dependencies => const <Target>[
	AotAssemblyProfile(),
	];
	}

	/// Build a release iOS application bundle.
	class ReleaseIosApplicationBundle extends IosAssetBundle {
	const ReleaseIosApplicationBundle();

	@override
	String get name => 'release_ios_bundle_flutter_assets';

	@override
	List<Target> get dependencies => const <Target>[
	AotAssemblyRelease(),
	];
	}

	/// Create an App.framework for debug iOS targets.
	///
	/// This framework needs to exist for the Xcode project to link/bundle,
	/// but it isn't actually executed. To generate something valid, we compile a trivial
	/// constant.
	Future<RunResult> createStubAppFramework(File outputFile, SdkType sdk, { bool include32Bit = true }) async {
	try {
	outputFile.createSync(recursive: true);
	} on Exception catch (e) {
	throwToolExit('Failed to create App.framework stub at ${outputFile.path}: $e');
	}

	final Directory tempDir = outputFile.fileSystem.systemTempDirectory
	.createTempSync('flutter_tools_stub_source.');
	try {
	final File stubSource = tempDir.childFile('debug_app.cc')
	..writeAsStringSync(r'''
	static const int Moo = 88;
	''');

	List<String> archFlags;
	if (sdk == SdkType.iPhone) {
	archFlags = <String>[
	if (include32Bit)
	...<String>['-arch', getNameForDarwinArch(DarwinArch.armv7)],
	'-arch',
	getNameForDarwinArch(DarwinArch.arm64),
	];
	} else {
	archFlags = <String>[
	'-arch',
	getNameForDarwinArch(DarwinArch.x86_64),
	];
	}

	return await globals.xcode.clang(<String>[
	'-x',
	'c',
	...archFlags,
	stubSource.path,
	'-dynamiclib',
	'-fembed-bitcode-marker',
	'-Xlinker', '-rpath', '-Xlinker', '@executable_path/Frameworks',
	'-Xlinker', '-rpath', '-Xlinker', '@loader_path/Frameworks',
	'-install_name', '@rpath/App.framework/App',
	'-isysroot', await globals.xcode.sdkLocation(sdk),
	'-o', outputFile.path,
	]);
	} finally {
	try {
	tempDir.deleteSync(recursive: true);
	} on FileSystemException {
	// Best effort. Sometimes we can't delete things from system temp.
	} on Exception catch (e) {
	throwToolExit('Failed to create App.framework stub at ${outputFile.path}: $e');
	}
	}
	}