Add utility tool to update .status files automatically

pkg/compiler/tool/status_files/update_from_log.dart

Index: pkg/compiler/tool/status_files/update_from_log.dart
diff --git a/pkg/compiler/tool/status_files/update_from_log.dart b/pkg/compiler/tool/status_files/update_from_log.dart
new file mode 100644
index 0000000000000000000000000000000000000000..91eb4aaebbd4b16af7b088c56926870a7debdf4f
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+++ b/pkg/compiler/tool/status_files/update_from_log.dart
@@ -0,0 +1,217 @@
+// Copyright (c) 2017, 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.
+
+/// Script that updates dart2js status lines automatically for tests under the
+/// '$dart2js_with_kernel' configuration.
+///
+/// This script is hardcoded to only support this configuration and relies on
+/// a convention for how the status files are structured, In particular,
+/// every status file for dart2js should have 2 sections:
+///
+///   [ $compiler == dart2js && $dart2js_with_kernel && $host_checked ]
+///
+/// and:
+///
+///     [ $compiler == dart2js && $dart2js_with_kernel && $minified ]
+library status_files.update_from_log;
+
+import 'dart:io';
+
+import 'record.dart';
+import 'log_parser.dart';
+
+final configurations = {
+  'checked':
+      r'[ $compiler == dart2js && $dart2js_with_kernel && $host_checked ]',
+  'minified': r'[ $compiler == dart2js && $dart2js_with_kernel && $minified ]',
+};
+
+final statusFiles = {
+  'language': 'tests/language/language_dart2js.status',
+  'corelib': 'tests/corelib/corelib.status',
+  'language_2': 'tests/language_2/language_2_dart2js.status',
+  // TODO(sigmund,rnystrom): update when corelib_2 gets split into multiple
+  // status files.
+  'corelib_2': 'tests/corelib_2/corelib_2.status',
+  'dart2js_extra': 'tests/compiler/dart2js_extra/dart2js_extra.status',
+  'dart2js_native': 'tests/compiler/dart2js_native/dart2js_native.status',
+};
+
+main(args) {
+  if (args.length < 2) {
+    print('usage: udpate_from_log.dart <mode> log.txt');
+    print('  where mode is one of these values: ${configurations.keys}');
+    exit(1);
+  }
+  var mode = args[0];
+  if (!configurations.containsKey(mode)) {
+    print('invalid mode: $mode, expected one in ${configurations.keys}');
+    exit(1);
+  }
+
+  var uri = Uri.base.resolve(args[1]);
+  var file = new File.fromUri(uri);
+  if (!file.existsSync()) {
+    print('file not found: $file');
+    exit(1);
+  }
+
+  updateLogs(mode, file.readAsStringSync());
+}
+
+/// Update all status files based on the [log] records when running the compiler
+/// in [mode].
+void updateLogs(String mode, String log) {
+  List<Record> records = parse(log);
+  records.sort();
+  var last;
+  var section;
+  for (var record in records) {
+    if (last == record) continue; // ignore duplicates
+    if (section?.suite != record.suite) {
+      section?.update();
+      section = ConfigurationInSuiteSection.create(record.suite, mode);
+    }
+    section.add(record);
+    last = record;
+  }
+  section?.update();
+}
+
+/// Represents an existing entry in the logs.
+class ExistingEntry {
+  final String test;
+  final String status;
+
+  ExistingEntry(this.test, this.status);
+
+  static parse(String line) {
+    var colonIndex = line.indexOf(':');
+    var test = line.substring(0, colonIndex);
+    var status = line.substring(colonIndex + 1).trim();
+    var commentIndex = status.indexOf("#");
+    if (commentIndex != -1) {
+      status = status.substring(0, commentIndex);
+    }
+    return new ExistingEntry(test, status);
+  }
+}
+
+/// Represents a section in a .status file that corresponds to a specific suite
+/// and configuration.
+class ConfigurationInSuiteSection {
+  final String suite;
+  final String _statusFile;
+  final String _contents;
+  final int _begin;
+  final int _end;
+  final List<Record> _records = [];
+
+  ConfigurationInSuiteSection(
+      this.suite, this._statusFile, this._contents, this._begin, this._end);
+
+  /// Add a new test record, indicating that the test status should be updated.
+  void add(Record record) => _records.add(record);
+
+  /// Update the section in the file.
+  ///
+  /// This will reflect the new status lines as recorded in [_records].
+  void update() {
+    int changes = 0;
+    int ignored = 0;
+    var originalEntries = _contents.substring(_begin, _end).split('\n');
+
+    // The algorithm below walks entries in the file and from the log in the
+    // same order: preserving entries that didn't change, and updating entries
+    // where the logs show that the test status changed.
+
+    // Records are already sorted, but we sort the file contents in case the
+    // file has been tampered with.
+    originalEntries.sort();
+
+    var newContents = new StringBuffer();
+    newContents.write(_contents.substring(0, _begin));
+    addFromRecord(Record record) {
+      newContents.writeln('${record.test}: ${record.actual}');
+    }
+
+    int i = 0, j = 0;
+    while (i < originalEntries.length && j < _records.length) {
+      var existingLine = originalEntries[i];
+      if (existingLine.trim().isEmpty) {
+        i++;
+        continue;
+      }
+      var existing = ExistingEntry.parse(existingLine);
+      var record = _records[j];
+      var compare = existing.test.compareTo(record.test);
+      if (compare < 0) {
+        // Existing test was unaffected, copy the status line.
+        newContents.writeln(existingLine);
+        i++;
+      } else if (compare > 0) {
+        // New entry, if it's a failure, we haven't seen this before and must
+        // add it. If the status says it is passing, we ignore it. We do this
+        // to support making this script idempotent if the patching has already
+        // been done.
+        if (!record.isPassing) {
+          // New failure never seen before
+          addFromRecord(record);
+          changes++;
+        }
+        j++;
+      } else if (existing.status == record.actual) {
+        // This also should only happen if the patching has already been done.
+        // We don't complain to make this script idempotent.
+        newContents.writeln(existingLine);
+        ignored++;
+        i++;
+        j++;
+      } else {
+        changes++;
+        // The status changed, if it is now passing, we omit the entry entirely,
+        // otherwise we use the status from the logs.
+        if (!record.isPassing) {
+          addFromRecord(record);
+        }
+        i++;
+        j++;
+      }
+    }
+
+    for (; i < originalEntries.length; i++) {
+      newContents.writeln(originalEntries[i]);
+    }
+
+    for (; j < _records.length; j++) {
+      changes++;
+      addFromRecord(_records[j]);
+    }
+
+    newContents.write('\n');
+    newContents.write(_contents.substring(_end));
+    new File(_statusFile).writeAsStringSync('$newContents');
+    print("updated '$_statusFile' with $changes changes");
+    if (ignored > 0) {
+      print('  $ignored changes were already applied in the status file.');
+    }
+  }
+
+  static ConfigurationInSuiteSection create(String suite, String mode) {
+    var statusFile = statusFiles[suite];
+    var contents = new File(statusFile).readAsStringSync();
+    var condition = configurations[mode];
+    int sectionDeclaration = contents.indexOf(condition);
+    if (sectionDeclaration == -1) {
+      print('error: unable to find condition $condition in $statusFile');
+      exit(1);
+    }
+    int begin = contents.indexOf('\n', sectionDeclaration) + 1;
+    assert(begin != 0);
+    int end = contents.indexOf('\n[', begin + 1);
+    end = end == -1 ? contents.length : end + 1;
+    return new ConfigurationInSuiteSection(
+        suite, statusFile, contents, begin, end);
+  }
+}