// 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 '../base/error_handling_io.dart'; import '../base/file_system.dart'; import '../base/logger.dart'; /// A service for creating and parsing [Depfile]s. class DepfileService { DepfileService({ required Logger logger, required FileSystem fileSystem, }) : _logger = logger, _fileSystem = fileSystem; final Logger _logger; final FileSystem _fileSystem; static final RegExp _separatorExpr = RegExp(r'([^\\]) '); static final RegExp _escapeExpr = RegExp(r'\\(.)'); /// Given an [depfile] File, write the depfile contents. /// /// If both [inputs] and [outputs] are empty, ensures the file does not /// exist. This can be overridden with the [writeEmpty] parameter when /// both static and runtime dependencies exist and it is not desired /// to force a rerun due to no depfile. void writeToFile(Depfile depfile, File output, {bool writeEmpty = false}) { if (depfile.inputs.isEmpty && depfile.outputs.isEmpty && !writeEmpty) { ErrorHandlingFileSystem.deleteIfExists(output); return; } final StringBuffer buffer = StringBuffer(); _writeFilesToBuffer(depfile.outputs, buffer); buffer.write(': '); _writeFilesToBuffer(depfile.inputs, buffer); output.writeAsStringSync(buffer.toString()); } /// Parse the depfile contents from [file]. /// /// If the syntax is invalid, returns an empty [Depfile]. Depfile parse(File file) { final String contents = file.readAsStringSync(); final List<String> colonSeparated = contents.split(': '); if (colonSeparated.length != 2) { _logger.printError('Invalid depfile: ${file.path}'); return const Depfile(<File>[], <File>[]); } final List<File> inputs = _processList(colonSeparated[1].trim()); final List<File> outputs = _processList(colonSeparated[0].trim()); return Depfile(inputs, outputs); } /// Parse the output of dart2js's used dependencies. /// /// The [file] contains a list of newline separated file URIs. The output /// file must be manually specified. Depfile parseDart2js(File file, File output) { final List<File> inputs = <File>[]; for (final String rawUri in file.readAsLinesSync()) { if (rawUri.trim().isEmpty) { continue; } final Uri? fileUri = Uri.tryParse(rawUri); if (fileUri == null) { continue; } if (fileUri.scheme != 'file') { continue; } inputs.add(_fileSystem.file(fileUri)); } return Depfile(inputs, <File>[output]); } void _writeFilesToBuffer(List<File> files, StringBuffer buffer) { for (final File outputFile in files) { if (_fileSystem.path.style.separator == r'\') { // backslashes and spaces in a depfile have to be escaped if the // platform separator is a backslash. final String path = outputFile.path .replaceAll(r'\', r'\\') .replaceAll(r' ', r'\ '); buffer.write(' $path'); } else { final String path = outputFile.path .replaceAll(r' ', r'\ '); buffer.write(' $path'); } } } List<File> _processList(String rawText) { return rawText // Put every file on right-hand side on the separate line .replaceAllMapped(_separatorExpr, (Match match) => '${match.group(1)}\n') .split('\n') // Expand escape sequences, so that '\ ', for example,ß becomes ' ' .map<String>((String path) => path.replaceAllMapped(_escapeExpr, (Match match) => match.group(1)!).trim()) .where((String path) => path.isNotEmpty) // The tool doesn't write duplicates to these lists. This call is an attempt to // be resilient to the outputs of other tools which write or user edits to depfiles. .toSet() .map(_fileSystem.file) .toList(); } } /// A class for representing depfile formats. class Depfile { /// Create a [Depfile] from a list of [input] files and [output] files. const Depfile(this.inputs, this.outputs); /// The input files for this depfile. final List<File> inputs; /// The output files for this depfile. final List<File> outputs; }