blob: c71e0d5f8a0547e1de52f1c569c11bdeb8c9d2c0 [file] [log] [blame] [edit]
// 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 'dart:io';
import 'package:args/args.dart';
import 'package:path/path.dart' as path;
final ArgParser argParser = ArgParser()
..addOption('output-dir')
..addOption('input-dir')
..addFlag('ui', defaultsTo: false)
..addFlag('engine', defaultsTo: false)
..addMultiOption('input')
..addOption('stamp');
final List<Replacer> uiPatterns = <Replacer>[
AllReplacer(RegExp(r'library\s+ui;'), 'library dart.ui;'),
AllReplacer(RegExp(r'part\s+of\s+ui;'), 'part of dart.ui;'),
AllReplacer(RegExp(r'''
import\s*'src/engine.dart'\s*as\s+engine;
'''), r'''
import 'dart:_engine' as engine;
'''),
AllReplacer(RegExp(
r'''
export\s*'src/engine.dart'
'''),
r'''
export 'dart:_engine'
''',
),
];
final List<Replacer> engineLibraryPatterns = <Replacer>[
AllReplacer(RegExp(r'library\s+engine;'), '''
@JS()
library dart._engine;
import 'dart:async';
import 'dart:collection';
import 'dart:convert' hide Codec;
import 'dart:developer' as developer;
import 'dart:js_util' as js_util;
import 'dart:_js_annotations';
import 'dart:math' as math;
import 'dart:typed_data';
import 'dart:ui' as ui;
'''),
// Replace exports of engine files with "part" directives.
MappedReplacer(RegExp(r'''
export\s*'engine/(.*)';
'''), (Match match) => '''
part 'engine/${match.group(1)}';
'''),
];
final List<Replacer> enginePartsPatterns = <Replacer>[
AllReplacer(RegExp(r'part\s+of\s+engine;'), 'part of dart._engine;'),
// Remove library-level JS annotations.
AllReplacer(RegExp(r'\n@JS(.*)\nlibrary .+;'), ''),
// Remove library directives.
AllReplacer(RegExp(r'\nlibrary .+;'), ''),
// Remove imports/exports from all engine parts.
AllReplacer(RegExp(r'\nimport\s*.*'), ''),
AllReplacer(RegExp(r'\nexport\s*.*'), ''),
];
final List<Replacer> sharedPatterns = <Replacer>[
AllReplacer(RegExp(r"import\s*'package:meta/meta.dart';"), ''),
AllReplacer('@required', ''),
AllReplacer('@protected', ''),
AllReplacer('@mustCallSuper', ''),
AllReplacer('@immutable', ''),
AllReplacer('@visibleForTesting', ''),
];
// Rewrites the "package"-style web ui library into a dart:ui implementation.
// So far this only requires a replace of the library declarations.
void main(List<String> arguments) {
final ArgResults results = argParser.parse(arguments);
final Directory directory = Directory(results['output-dir'] as String);
final String inputDirectoryPath = results['input-dir'] as String;
for (final String inputFilePath in results['input'] as Iterable<String>) {
final File inputFile = File(inputFilePath);
final File outputFile = File(path.join(
directory.path, inputFile.path.substring(inputDirectoryPath.length)))
..createSync(recursive: true);
final String source = inputFile.readAsStringSync();
final String rewrittenContent = rewriteFile(
source,
filePath: inputFilePath,
isUi: results['ui'] as bool,
isEngine: results['engine'] as bool,
);
outputFile.writeAsStringSync(rewrittenContent);
if (results['stamp'] != null) {
File(results['stamp'] as String).writeAsStringSync('stamp');
}
}
}
String rewriteFile(String source, {required String filePath, required bool isUi, required bool isEngine}) {
final List<Replacer> replacementPatterns = <Replacer>[];
replacementPatterns.addAll(sharedPatterns);
if (isUi) {
replacementPatterns.addAll(uiPatterns);
} else if (isEngine) {
if (filePath.endsWith('lib/src/engine.dart')) {
_validateEngineSource(filePath, source);
replacementPatterns.addAll(engineLibraryPatterns);
} else {
source = _preprocessEnginePartFile(source);
replacementPatterns.addAll(enginePartsPatterns);
}
}
for (final Replacer replacer in replacementPatterns) {
source = replacer.perform(source);
}
return source;
}
// Enforces a particular structure in engine.dart source code.
//
// Code in `engine.dart` must only be made of the library directive, exports,
// and code comments. Imports are disallowed. Instead, the required imports are
// added by this script during the rewrite.
void _validateEngineSource(String engineDartPath, String engineDartCode) {
const List<String> expectedLines = <String>[
'library engine;',
];
final List<String> lines = engineDartCode.split('\n');
for (int i = 0; i < lines.length; i += 1) {
final int lineNumber = i + 1;
final String line = lines[i].trim();
if (line.isEmpty) {
// Emply lines are OK
continue;
}
if (expectedLines.contains(line)) {
// Expected; let it pass.
continue;
}
if (line.startsWith('//')) {
// Comments are OK
continue;
}
if (line.startsWith('export')) {
// Exports are OK
continue;
}
throw Exception(
'on line $lineNumber: unexpected code in $engineDartPath. This file '
'may only contain comments and exports. Found:\n'
'$line'
);
}
}
String _preprocessEnginePartFile(String source) {
if (source.startsWith('part of engine;') || source.contains('\npart of engine;')) {
// The file hasn't been migrated yet.
// Do nothing.
} else {
// Insert the part directive at the beginning of the file.
source = 'part of engine;\n' + source;
}
return source;
}
/// Responsible for performing string replacements.
abstract class Replacer {
/// Performs the replacement in the provided [text].
String perform(String text);
}
/// Replaces all occurrences of a pattern with a fixed string.
class AllReplacer implements Replacer {
/// Creates a new tuple with the given [pattern] and [replacement] string.
AllReplacer(this._pattern, this._replacement);
/// The pattern to be replaced.
final Pattern _pattern;
/// The replacement string.
final String _replacement;
@override
String perform(String text) {
return text.replaceAll(_pattern, _replacement);
}
}
/// Uses a callback to replace each occurrence of a pattern.
class MappedReplacer implements Replacer {
MappedReplacer(this._pattern, this._replace);
/// The pattern to be replaced.
final RegExp _pattern;
/// A callback to replace each occurrence of [_pattern].
final String Function(Match match) _replace;
@override
String perform(String text) {
return text.replaceAllMapped(_pattern, _replace);
}
}