packages/flutter_build/lib/src/kernel_builder.dart - mirrors/flutter - Git at Google

 // Copyright 2019 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 // Note: this Builder does not run in the same process as the flutter_tool, so
 // the DI provided getters such as `fs` will not work.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';

 import 'package:build_modules/build_modules.dart';
 import 'package:build/build.dart';
 import 'package:package_config/packages_file.dart' as packages_file;
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;

 const String _kFlutterDillOutputExtension = '.app.dill';
 const String _kPackagesExtension = '.packages';

 /// A builder which creates a kernel and packages file for a Flutter app.
 ///
 /// Unlike the package:build kernel builders, this creates a single kernel from
 /// dart source using the frontend server binary. The newly created .package
 /// file replaces the relative root of the current package with a multi-root
 /// which includes the generated directory.
 class FlutterKernelBuilder implements Builder {
   const FlutterKernelBuilder({
     @required this.disabled,
     @required this.mainPath,
     @required this.aot,
     @required this.trackWidgetCreation,
     @required this.targetProductVm,
     @required this.linkPlatformKernelIn,
     @required this.extraFrontEndOptions,
     @required this.sdkRoot,
     @required this.packagesPath,
     @required this.incrementalCompilerByteStorePath,
     @required this.frontendServerPath,
     @required this.engineDartBinaryPath,
   });

   /// The path to the entrypoint that will be compiled.
   final String mainPath;

   /// The path to the pub generated .packages file.
   final String packagesPath;

   /// The path to the root of the flutter patched SDK.
   final String sdkRoot;

   /// The path to the frontend server snapshot.
   final String frontendServerPath;

   /// The path to the dart executable to use to run the frontend server
   /// snapshot.
   final String engineDartBinaryPath;

   /// Whether to build an ahead of time build.
   final bool aot;

   /// Whether to disable production of kernel.
   final bool disabled;

   /// Whether the `trackWidgetCreation` flag is provided to the frontend
   /// server.
   final bool trackWidgetCreation;

   /// Whether to provide the Dart product define to the frontend server.
   final bool targetProductVm;

   /// When in batch mode, link platform kernel file into result kernel file.
   final bool linkPlatformKernelIn;

   /// Whether to compile incrementally.
   final String incrementalCompilerByteStorePath;

   /// Additional arguments to pass to the frontend server.
   final List<String> extraFrontEndOptions;

   @override
   Map<String, List<String>> get buildExtensions => const <String, List<String>>{
     '.dart': <String>[_kFlutterDillOutputExtension, _kPackagesExtension],
   };

   @override
   Future<void> build(BuildStep buildStep) async {
     // Do not resolve dependencies if this does not correspond to the main
     // entrypoint.
     if (!mainPath.contains(buildStep.inputId.path)) {
       return;
     }
     final AssetId outputId = buildStep.inputId.changeExtension(_kFlutterDillOutputExtension);
     final AssetId packagesOutputId = buildStep.inputId.changeExtension(_kPackagesExtension);

     // Use modules to verify dependencies are sound.
     final AssetId moduleId = buildStep.inputId.changeExtension(moduleExtension(DartPlatform.flutter));
     final Module module = Module.fromJson(json.decode(await buildStep.readAsString(moduleId)));
     try {
       await module.computeTransitiveDependencies(buildStep);
     } on MissingModulesException catch (err) {
       log.shout(err);
       return;
     }

     // Do not generate kernel if it has been disabled.
     if (disabled) {
       return;
     }

     // Create a scratch space file that can be read/written by the frontend server.
     // It is okay to hard-code these file names because we will copy them back
     // from the temp directory at the end of the build step.
     final Directory tempDirecory = await Directory.systemTemp.createTemp('_flutter_build');
     final File packagesFile = File(path.join(tempDirecory.path, _kPackagesExtension));
     final File outputFile =  File(path.join(tempDirecory.path, 'main.app.dill'));
     await outputFile.create();
     await packagesFile.create();

     final Directory projectDir = File(packagesPath).parent;
     final String packageName = buildStep.inputId.package;
     final String oldPackagesContents = await File(packagesPath).readAsString();
     // Note: currently we only replace the root package with a multiroot
     // scheme. To support codegen on arbitrary packages we will need to do
     // this for each dependency.
     final String newPackagesContents = oldPackagesContents.replaceFirst('$packageName:lib/', '$packageName:$multiRootScheme:/');
     await packagesFile.writeAsString(newPackagesContents);
     String absoluteMainPath;
     if (path.isAbsolute(mainPath)) {
       absoluteMainPath = mainPath;
     } else {
       absoluteMainPath = path.join(projectDir.absolute.path, mainPath);
     }

     // start up the frontend server with configuration.
     final List<String> arguments = <String>[
       frontendServerPath,
       '--sdk-root',
       sdkRoot,
       '--strong',
       '--target=flutter',
     ];
     if (trackWidgetCreation) {
       arguments.add('--track-widget-creation');
     }
     if (!linkPlatformKernelIn) {
       arguments.add('--no-link-platform');
     }
     if (aot) {
       arguments.add('--aot');
       arguments.add('--tfa');
     }
     if (targetProductVm) {
       arguments.add('-Ddart.vm.product=true');
     }
     if (incrementalCompilerByteStorePath != null) {
       arguments.add('--incremental');
     }
     final String generatedRoot = path.join(projectDir.absolute.path, '.dart_tool', 'build', 'generated', '$packageName', 'lib${Platform.pathSeparator}');
     final String normalRoot =  path.join(projectDir.absolute.path, 'lib${Platform.pathSeparator}');
     arguments.addAll(<String>[
       '--packages',
       Uri.file(packagesFile.path).toString(),
       '--output-dill',
       outputFile.path,
       '--filesystem-root',
       normalRoot,
       '--filesystem-root',
       generatedRoot,
       '--filesystem-scheme',
       multiRootScheme,
     ]);
     if (extraFrontEndOptions != null) {
       arguments.addAll(extraFrontEndOptions);
     }
     final Uri mainUri = _PackageUriMapper.findUri(
       absoluteMainPath,
       packagesFile.path,
       multiRootScheme,
       <String>[normalRoot, generatedRoot],
     );
     arguments.add(mainUri?.toString() ?? absoluteMainPath);
     // Invoke the frontend server and copy the dill back to the output
     // directory.
     try {
       final Process server = await Process.start(engineDartBinaryPath, arguments);
       final _StdoutHandler _stdoutHandler = _StdoutHandler();
       server.stderr
         .transform<String>(utf8.decoder)
         .listen(log.shout);
       server.stdout
         .transform<String>(utf8.decoder)
         .transform<String>(const LineSplitter())
         .listen(_stdoutHandler.handler);
       await server.exitCode;
       await _stdoutHandler.compilerOutput.future;
       await buildStep.writeAsBytes(outputId, await outputFile.readAsBytes());
       await buildStep.writeAsBytes(packagesOutputId, await packagesFile.readAsBytes());
     } catch (err, stackTrace) {
       log.shout('frontend server failed to start: $err, $stackTrace');
     }
   }
 }

 class _StdoutHandler {
   _StdoutHandler() {
     reset();
   }

   bool compilerMessageReceived = false;
   String boundaryKey;
   Completer<_CompilerOutput> compilerOutput;

   bool _suppressCompilerMessages;

   void handler(String message) {
     const String kResultPrefix = 'result ';
     if (boundaryKey == null) {
       if (message.startsWith(kResultPrefix))
         boundaryKey = message.substring(kResultPrefix.length);
     } else if (message.startsWith(boundaryKey)) {
       if (message.length <= boundaryKey.length) {
         compilerOutput.complete(null);
         return;
       }
       final int spaceDelimiter = message.lastIndexOf(' ');
       compilerOutput.complete(
         _CompilerOutput(
           message.substring(boundaryKey.length + 1, spaceDelimiter),
           int.parse(message.substring(spaceDelimiter + 1).trim())));
     } else if (!_suppressCompilerMessages) {
       if (compilerMessageReceived == false) {
         log.info('\nCompiler message:');
         compilerMessageReceived = true;
       }
       log.info(message);
     }
   }

   // This is needed to get ready to process next compilation result output,
   // with its own boundary key and new completer.
   void reset({bool suppressCompilerMessages = false}) {
     boundaryKey = null;
     compilerMessageReceived = false;
     compilerOutput = Completer<_CompilerOutput>();
     _suppressCompilerMessages = suppressCompilerMessages;
   }
 }


 class _CompilerOutput {
   const _CompilerOutput(this.outputFilename, this.errorCount);

   final String outputFilename;
   final int errorCount;
 }

 /// Converts filesystem paths to package URIs.
 class _PackageUriMapper {
   _PackageUriMapper(String scriptPath, String packagesPath, String fileSystemScheme, List<String> fileSystemRoots) {
     final List<int> bytes = File(path.absolute(packagesPath)).readAsBytesSync();
     final Map<String, Uri> packageMap = packages_file.parse(bytes, Uri.file(packagesPath, windows: Platform.isWindows));
     final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();

     for (String packageName in packageMap.keys) {
       final String prefix = packageMap[packageName].toString();
       if (fileSystemScheme != null && fileSystemRoots != null && prefix.contains(fileSystemScheme)) {
         _packageName = packageName;
         _uriPrefixes = fileSystemRoots
           .map((String name) => Uri.file(name, windows: Platform.isWindows).toString())
           .toList();
         return;
       }
       if (scriptUri.startsWith(prefix)) {
         _packageName = packageName;
         _uriPrefixes = <String>[prefix];
         return;
       }
     }
   }

   String _packageName;
   List<String> _uriPrefixes;

   Uri map(String scriptPath) {
     if (_packageName == null) {
       return null;
     }
     final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();
     for (String uriPrefix in _uriPrefixes) {
       if (scriptUri.startsWith(uriPrefix)) {
         return Uri.parse('package:$_packageName/${scriptUri.substring(uriPrefix.length)}');
       }
     }
     return null;
   }

   static Uri findUri(String scriptPath, String packagesPath, String fileSystemScheme, List<String> fileSystemRoots) {
     return _PackageUriMapper(scriptPath, packagesPath, fileSystemScheme, fileSystemRoots).map(scriptPath);
   }
 }
	// Copyright 2019 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	// Note: this Builder does not run in the same process as the flutter_tool, so
	// the DI provided getters such as `fs` will not work.
	import 'dart:async';
	import 'dart:convert';
	import 'dart:io';

	import 'package:build_modules/build_modules.dart';
	import 'package:build/build.dart';
	import 'package:package_config/packages_file.dart' as packages_file;
	import 'package:meta/meta.dart';
	import 'package:path/path.dart' as path;

	const String _kFlutterDillOutputExtension = '.app.dill';
	const String _kPackagesExtension = '.packages';

	/// A builder which creates a kernel and packages file for a Flutter app.
	///
	/// Unlike the package:build kernel builders, this creates a single kernel from
	/// dart source using the frontend server binary. The newly created .package
	/// file replaces the relative root of the current package with a multi-root
	/// which includes the generated directory.
	class FlutterKernelBuilder implements Builder {
	const FlutterKernelBuilder({
	@required this.disabled,
	@required this.mainPath,
	@required this.aot,
	@required this.trackWidgetCreation,
	@required this.targetProductVm,
	@required this.linkPlatformKernelIn,
	@required this.extraFrontEndOptions,
	@required this.sdkRoot,
	@required this.packagesPath,
	@required this.incrementalCompilerByteStorePath,
	@required this.frontendServerPath,
	@required this.engineDartBinaryPath,
	});

	/// The path to the entrypoint that will be compiled.
	final String mainPath;

	/// The path to the pub generated .packages file.
	final String packagesPath;

	/// The path to the root of the flutter patched SDK.
	final String sdkRoot;

	/// The path to the frontend server snapshot.
	final String frontendServerPath;

	/// The path to the dart executable to use to run the frontend server
	/// snapshot.
	final String engineDartBinaryPath;

	/// Whether to build an ahead of time build.
	final bool aot;

	/// Whether to disable production of kernel.
	final bool disabled;

	/// Whether the `trackWidgetCreation` flag is provided to the frontend
	/// server.
	final bool trackWidgetCreation;

	/// Whether to provide the Dart product define to the frontend server.
	final bool targetProductVm;

	/// When in batch mode, link platform kernel file into result kernel file.
	final bool linkPlatformKernelIn;

	/// Whether to compile incrementally.
	final String incrementalCompilerByteStorePath;

	/// Additional arguments to pass to the frontend server.
	final List<String> extraFrontEndOptions;

	@override
	Map<String, List<String>> get buildExtensions => const <String, List<String>>{
	'.dart': <String>[_kFlutterDillOutputExtension, _kPackagesExtension],
	};

	@override
	Future<void> build(BuildStep buildStep) async {
	// Do not resolve dependencies if this does not correspond to the main
	// entrypoint.
	if (!mainPath.contains(buildStep.inputId.path)) {
	return;
	}
	final AssetId outputId = buildStep.inputId.changeExtension(_kFlutterDillOutputExtension);
	final AssetId packagesOutputId = buildStep.inputId.changeExtension(_kPackagesExtension);

	// Use modules to verify dependencies are sound.
	final AssetId moduleId = buildStep.inputId.changeExtension(moduleExtension(DartPlatform.flutter));
	final Module module = Module.fromJson(json.decode(await buildStep.readAsString(moduleId)));
	try {
	await module.computeTransitiveDependencies(buildStep);
	} on MissingModulesException catch (err) {
	log.shout(err);
	return;
	}

	// Do not generate kernel if it has been disabled.
	if (disabled) {
	return;
	}

	// Create a scratch space file that can be read/written by the frontend server.
	// It is okay to hard-code these file names because we will copy them back
	// from the temp directory at the end of the build step.
	final Directory tempDirecory = await Directory.systemTemp.createTemp('_flutter_build');
	final File packagesFile = File(path.join(tempDirecory.path, _kPackagesExtension));
	final File outputFile = File(path.join(tempDirecory.path, 'main.app.dill'));
	await outputFile.create();
	await packagesFile.create();

	final Directory projectDir = File(packagesPath).parent;
	final String packageName = buildStep.inputId.package;
	final String oldPackagesContents = await File(packagesPath).readAsString();
	// Note: currently we only replace the root package with a multiroot
	// scheme. To support codegen on arbitrary packages we will need to do
	// this for each dependency.
	final String newPackagesContents = oldPackagesContents.replaceFirst('$packageName:lib/', '$packageName:$multiRootScheme:/');
	await packagesFile.writeAsString(newPackagesContents);
	String absoluteMainPath;
	if (path.isAbsolute(mainPath)) {
	absoluteMainPath = mainPath;
	} else {
	absoluteMainPath = path.join(projectDir.absolute.path, mainPath);
	}

	// start up the frontend server with configuration.
	final List<String> arguments = <String>[
	frontendServerPath,
	'--sdk-root',
	sdkRoot,
	'--strong',
	'--target=flutter',
	];
	if (trackWidgetCreation) {
	arguments.add('--track-widget-creation');
	}
	if (!linkPlatformKernelIn) {
	arguments.add('--no-link-platform');
	}
	if (aot) {
	arguments.add('--aot');
	arguments.add('--tfa');
	}
	if (targetProductVm) {
	arguments.add('-Ddart.vm.product=true');
	}
	if (incrementalCompilerByteStorePath != null) {
	arguments.add('--incremental');
	}
	final String generatedRoot = path.join(projectDir.absolute.path, '.dart_tool', 'build', 'generated', '$packageName', 'lib${Platform.pathSeparator}');
	final String normalRoot = path.join(projectDir.absolute.path, 'lib${Platform.pathSeparator}');
	arguments.addAll(<String>[
	'--packages',
	Uri.file(packagesFile.path).toString(),
	'--output-dill',
	outputFile.path,
	'--filesystem-root',
	normalRoot,
	'--filesystem-root',
	generatedRoot,
	'--filesystem-scheme',
	multiRootScheme,
	]);
	if (extraFrontEndOptions != null) {
	arguments.addAll(extraFrontEndOptions);
	}
	final Uri mainUri = _PackageUriMapper.findUri(
	absoluteMainPath,
	packagesFile.path,
	multiRootScheme,
	<String>[normalRoot, generatedRoot],
	);
	arguments.add(mainUri?.toString() ?? absoluteMainPath);
	// Invoke the frontend server and copy the dill back to the output
	// directory.
	try {
	final Process server = await Process.start(engineDartBinaryPath, arguments);
	final _StdoutHandler _stdoutHandler = _StdoutHandler();
	server.stderr
	.transform<String>(utf8.decoder)
	.listen(log.shout);
	server.stdout
	.transform<String>(utf8.decoder)
	.transform<String>(const LineSplitter())
	.listen(_stdoutHandler.handler);
	await server.exitCode;
	await _stdoutHandler.compilerOutput.future;
	await buildStep.writeAsBytes(outputId, await outputFile.readAsBytes());
	await buildStep.writeAsBytes(packagesOutputId, await packagesFile.readAsBytes());
	} catch (err, stackTrace) {
	log.shout('frontend server failed to start: $err, $stackTrace');
	}
	}
	}

	class _StdoutHandler {
	_StdoutHandler() {
	reset();
	}

	bool compilerMessageReceived = false;
	String boundaryKey;
	Completer<_CompilerOutput> compilerOutput;

	bool _suppressCompilerMessages;

	void handler(String message) {
	const String kResultPrefix = 'result ';
	if (boundaryKey == null) {
	if (message.startsWith(kResultPrefix))
	boundaryKey = message.substring(kResultPrefix.length);
	} else if (message.startsWith(boundaryKey)) {
	if (message.length <= boundaryKey.length) {
	compilerOutput.complete(null);
	return;
	}
	final int spaceDelimiter = message.lastIndexOf(' ');
	compilerOutput.complete(
	_CompilerOutput(
	message.substring(boundaryKey.length + 1, spaceDelimiter),
	int.parse(message.substring(spaceDelimiter + 1).trim())));
	} else if (!_suppressCompilerMessages) {
	if (compilerMessageReceived == false) {
	log.info('\nCompiler message:');
	compilerMessageReceived = true;
	}
	log.info(message);
	}
	}

	// This is needed to get ready to process next compilation result output,
	// with its own boundary key and new completer.
	void reset({bool suppressCompilerMessages = false}) {
	boundaryKey = null;
	compilerMessageReceived = false;
	compilerOutput = Completer<_CompilerOutput>();
	_suppressCompilerMessages = suppressCompilerMessages;
	}
	}


	class _CompilerOutput {
	const _CompilerOutput(this.outputFilename, this.errorCount);

	final String outputFilename;
	final int errorCount;
	}

	/// Converts filesystem paths to package URIs.
	class _PackageUriMapper {
	_PackageUriMapper(String scriptPath, String packagesPath, String fileSystemScheme, List<String> fileSystemRoots) {
	final List<int> bytes = File(path.absolute(packagesPath)).readAsBytesSync();
	final Map<String, Uri> packageMap = packages_file.parse(bytes, Uri.file(packagesPath, windows: Platform.isWindows));
	final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();

	for (String packageName in packageMap.keys) {
	final String prefix = packageMap[packageName].toString();
	if (fileSystemScheme != null && fileSystemRoots != null && prefix.contains(fileSystemScheme)) {
	_packageName = packageName;
	_uriPrefixes = fileSystemRoots
	.map((String name) => Uri.file(name, windows: Platform.isWindows).toString())
	.toList();
	return;
	}
	if (scriptUri.startsWith(prefix)) {
	_packageName = packageName;
	_uriPrefixes = <String>[prefix];
	return;
	}
	}
	}

	String _packageName;
	List<String> _uriPrefixes;

	Uri map(String scriptPath) {
	if (_packageName == null) {
	return null;
	}
	final String scriptUri = Uri.file(scriptPath, windows: Platform.isWindows).toString();
	for (String uriPrefix in _uriPrefixes) {
	if (scriptUri.startsWith(uriPrefix)) {
	return Uri.parse('package:$_packageName/${scriptUri.substring(uriPrefix.length)}');
	}
	}
	return null;
	}

	static Uri findUri(String scriptPath, String packagesPath, String fileSystemScheme, List<String> fileSystemRoots) {
	return _PackageUriMapper(scriptPath, packagesPath, fileSystemScheme, fileSystemRoots).map(scriptPath);
	}
	}