[native_stack_traces] Remove initial spaces check in stack trace lines.

The strictness of the old "check for four spaces" was causing failures
in `flutter symbolize`, and there's no reason to check how much initial
whitespace we got prior to the line contents anyway.

TEST=pkg/native_stack_traces/test/convert/regress_262474517_test

Change-Id: I6a6e31732cb2a5b5d40a088b9a04877052726be2
Bug: b/262474517
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/276905
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Commit-Queue: Tess Strickland <sstrickl@google.com>

pkg/native_stack_traces/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.5.4
+
+- Relaxed requirement for spaces before non-symbolic stack trace line.
+
 ## 0.5.3
 
 - Exported more ELF utilities for use in Dart tests.

pkg/native_stack_traces/lib/src/convert.dart

@@ -125,9 +125,9 @@ const _symbolOffsetREString = r'(?<symbol>' +
     constants.isolateSymbolName +
     r')\+(?<offset>(?:0x)?[\da-f]+)';
 final _symbolOffsetRE = RegExp(_symbolOffsetREString);
-final _traceLineRE = RegExp(
-    r'    #(\d+) abs (?<absolute>[\da-f]+)(?: virt (?<virtual>[\da-f]+))? '
-    r'(?<rest>.*)$');
+final _traceLineRE =
+    RegExp(r'#(\d+) abs (?<absolute>[\da-f]+)(?: virt (?<virtual>[\da-f]+))? '
+        r'(?<rest>.*)$');
 
 /// Parses strings of the format <static symbol>+<integer offset>, where
 /// <static symbol> is one of the static symbols used for Dart instruction

pkg/native_stack_traces/pubspec.yaml

@@ -1,5 +1,5 @@
 name: native_stack_traces
-version: 0.5.3
+version: 0.5.4
 description: Utilities for working with non-symbolic stack traces.
 repository: https://github.com/dart-lang/sdk/tree/main/pkg/native_stack_traces
 
@@ -19,3 +19,4 @@ dependencies:
 # See also https://dart.dev/tools/pub/dependencies.
 dev_dependencies:
   lints: any
+  test: any

pkg/native_stack_traces/test/convert/regress_262474517_test.dart

@@ -0,0 +1,33 @@
+// Copyright (c) 2022, 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 'package:native_stack_traces/src/convert.dart';
+import 'package:native_stack_traces/src/dwarf.dart';
+import 'package:path/path.dart' as path;
+import 'package:test/test.dart';
+
+void main() {
+  group('convert tests', defineConvertTests);
+}
+
+final String pkgDir = Platform.script.resolve('../..').toFilePath();
+
+void defineConvertTests() {
+  test('b/262474517 regression', () async {
+    final inputPath = path.join(
+        pkgDir, 'testcases', 'convert', 'regress_262474517_trace.txt');
+    final contents = await File(inputPath).readAsLines();
+    final pcOffsets = collectPCOffsets(contents);
+    expect(pcOffsets.map((o) => o.offset).toList(),
+        [0x14e87f, 0x2a4e27, 0x4ee12b, 0x477fc7]);
+    expect(pcOffsets.map((o) => o.section).toList(), [
+      InstructionsSection.isolate,
+      InstructionsSection.isolate,
+      InstructionsSection.isolate,
+      InstructionsSection.isolate
+    ]);
+  });
+}

pkg/native_stack_traces/testcases/convert/regress_262474517_trace.txt

@@ -0,0 +1,6 @@
+Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Bad state: No element. Error thrown null.
+BuildId: c3126a4381294e13185549e5e94a4db9
+at . #00 abs 0 virt 000000000031ba6f _kDartIsolateSnapshotInstructions+0x14e87f
+at . #01 abs 0 virt 0000000000472017 _kDartIsolateSnapshotInstructions+0x2a4e27
+at . #02 abs 0 virt 00000000006bb31b _kDartIsolateSnapshotInstructions+0x4ee12b
+at . #03 abs 0 virt 00000000006451b7 _kDartIsolateSnapshotInstructions+0x477fc7