blob: b68b32fc727f061672294269279f9f832063736e [file] [log] [blame]
#!/usr/bin/env dart
// Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
// for details. 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 'dart:typed_data';
import 'package:kernel/kernel.dart'
show Component, Source, loadComponentFromBytes;
import 'package:kernel/binary/tag.dart' show Tag;
void main(List<String> args) {
if (args.length != 1) {
throw "Usage: dart <script> <dillFile>";
}
File file = new File(args.single);
if (!file.existsSync()) {
throw "Given file doesn't exist.\n"
"Usage: dart <script> <dillFile>";
}
Uint8List bytes = file.readAsBytesSync();
List<Component> components = splitAndRead(bytes);
print("Successfully read ${components.length} sub-components.");
for (int i = 0; i < components.length; i++) {
Component component = components[i];
print("Component #${i + 1}:");
for (MapEntry<Uri, Source> entry in component.uriToSource.entries) {
String importUri = entry.value.importUri.toString();
String fileUri = entry.key.toString();
if (importUri != fileUri) {
print(" - $importUri ($fileUri)");
} else {
print(" - $fileUri");
}
}
}
// TODO(jensj): Could we read _some_ (useful) data from a partial component
// (e.g. one that stops after the first few libraries)?
}
List<Component> splitAndRead(Uint8List bytes) {
List<Component> components = [];
// Search for magic component file tag.
List<int> magicTagBytes = [
(Tag.ComponentFile >> 24) & 0XFF,
(Tag.ComponentFile >> 16) & 0XFF,
(Tag.ComponentFile >> 8) & 0XFF,
(Tag.ComponentFile >> 0) & 0XFF,
];
List<int> tagOffsets = [];
for (int index = 0; index < bytes.length - 7; index++) {
if (bytes[index] == magicTagBytes[0] &&
bytes[index + 1] == magicTagBytes[1] &&
bytes[index + 2] == magicTagBytes[2] &&
bytes[index + 3] == magicTagBytes[3]) {
// Try to read binary version too and see if it matches.
int version = (bytes[index + 4] << 24) |
(bytes[index + 5] << 16) |
(bytes[index + 6] << 8) |
bytes[index + 7];
if (version != Tag.BinaryFormatVersion) {
print("Found tag, but version mismatches "
"('$version' vs readable version '${Tag.BinaryFormatVersion}'). "
"Try again in a different checkout.");
} else {
tagOffsets.add(index);
}
}
}
print("Found ${tagOffsets.length} possible tag offsets.");
// Add fake file tag after end of bytes to also attempt "last component".
tagOffsets.add(bytes.length);
// Warning: O(n²) algorithm (though, as the tag is assumed to be rather unique
// in normal cases it will probably much better in practice
// (and n will be low)).
int fromIndex = 0;
while (fromIndex < tagOffsets.length - 1) {
int toIndex = fromIndex + 1;
while (toIndex < tagOffsets.length) {
// Cut bytes and try to load.
int fromOffset = tagOffsets[fromIndex];
int toOffset = tagOffsets[toIndex];
Uint8List bytesView =
new Uint8List.sublistView(bytes, fromOffset, toOffset);
try {
Component loaded = loadComponentFromBytes(bytesView);
components.add(loaded);
print("Loaded from tag ${fromIndex} to ${toIndex}.");
break;
} catch (e) {
print("Failed loading from tag ${fromIndex} to ${toIndex}"
" (${toOffset - fromOffset} bytes).");
toIndex++;
}
}
fromIndex++;
}
return components;
}