[vm/aot] Fix crash in AddConstObject

It used `ObjectVisitor` to peak into constant objects. The visitor
called `AddConstObject` directly while keeping raw pointers around.
This is unsafe because `AddConstObject` can cause GC for several
different reasons - which would potentially invalidate those raw
pointers.

I have added `NoSafepointScope` around `VisitPointers` but this
does not actually easily reveal the bug because allocations are
really sporadic and often require to be running in PRODUCT mode
to trigger corresponding code path. Unfortunately we don't have
any existing infrastructure to catch "allocation from unsafe
place" which works across all build modes and catches even
situations where allocation can _potentially_ happen.

Fixes https://github.com/flutter/flutter/issues/153358

TEST=manually with a reproduction provided by internal user.
R=kustermann@google.com

Change-Id: I0c9e14a137b1f8ac749443d80f6904f1e9b20ed7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/382883
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Slava Egorov <vegorov@google.com>
1 file changed
tree: bea6b1d67a254e77d9a81396286c244ca0a26d2b
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. docs/
  6. pkg/
  7. runtime/
  8. samples/
  9. sdk/
  10. tests/
  11. third_party/
  12. tools/
  13. utils/
  14. .clang-format
  15. .gitattributes
  16. .gitconfig
  17. .gitignore
  18. .gn
  19. .mailmap
  20. .style.yapf
  21. AUTHORS
  22. BUILD.gn
  23. CHANGELOG.md
  24. codereview.settings
  25. CONTRIBUTING.md
  26. DEPS
  27. LICENSE
  28. OWNERS
  29. PATENT_GRANT
  30. PRESUBMIT.py
  31. README.dart-sdk
  32. README.md
  33. sdk.code-workspace
  34. sdk_args.gni
  35. sdk_packages.yaml
  36. SECURITY.md
  37. WATCHLISTS
README.md

Dart

An approachable, portable, and productive language for high-quality apps on any platform

Dart is:

  • Approachable: Develop with a strongly typed programming language that is consistent, concise, and offers modern language features like null safety and patterns.

  • Portable: Compile to ARM, x64, or RISC-V machine code for mobile, desktop, and backend. Compile to JavaScript or WebAssembly for the web.

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app. Diagnose app issues using DevTools.

Dart's flexible compiler technology lets you run Dart code in different ways, depending on your target platform and goals:

  • Dart Native: For programs targeting devices (mobile, desktop, server, and more), Dart Native includes both a Dart VM with JIT (just-in-time) compilation and an AOT (ahead-of-time) compiler for producing machine code.

  • Dart Web: For programs targeting the web, Dart Web includes both a development time compiler (dartdevc) and a production time compiler (dart2js).

Dart platforms illustration

License & patents

Dart is free and open source.

See LICENSE and PATENT_GRANT.

Using Dart

Visit dart.dev to learn more about the language, tools, and to find codelabs.

Browse pub.dev for more packages and libraries contributed by the community and the Dart team.

Our API reference documentation is published at api.dart.dev, based on the stable release. (We also publish docs from our beta and dev channels, as well as from the primary development branch).

Building Dart

If you want to build Dart yourself, here is a guide to getting the source, preparing your machine to build the SDK, and building.

There are more documents in our repo at docs.

Contributing to Dart

The easiest way to contribute to Dart is to file issues.

You can also contribute patches, as described in Contributing.

Roadmap

Future plans for Dart are included in the combined Dart and Flutter roadmap on the Flutter wiki.