[dart2js] Add --experiment-unreachable-throw

If a method appears unreachable because a parameter is inferred
'[empty]', compile the body to a throw.

Playing with the flag found some cases where the inferrer was not
inferring parameters because the call sites are not visible in Kernel.
The first example is _isTestViaProperty, which is referenced as a raw
function. To fix this we consider RAW_DART_FUNCTION_REF to escape the
function. The inputs are now inferred to be TOP, and we can remove the
dynamic entry checks with 'trust' annotations.

Other cases are functions that are injected into generators by a
JavaScript-level transform. Annotate these to prevent bad codegen.



Change-Id: I991fe85936ffde6fc2c794f753171df141dde8f3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/162822
Commit-Queue: Stephen Adams <sra@google.com>
Reviewed-by: Mayank Patke <fishythefish@google.com>
8 files changed
tree: ed7c8ed2a353cb5e350d5fcb6a0b474689cfdffc
  1. .dart_tool/
  2. .github/
  3. benchmarks/
  4. build/
  5. client/
  6. docs/
  7. pkg/
  8. runtime/
  9. samples/
  10. samples-dev/
  11. sdk/
  12. tests/
  13. third_party/
  14. tools/
  15. utils/
  16. .clang-format
  17. .gitattributes
  18. .gitconfig
  19. .gitignore
  20. .gn
  21. .mailmap
  22. .packages
  23. .style.yapf
  24. .vpython
  25. AUTHORS
  26. BUILD.gn
  27. CHANGELOG.md
  28. codereview.settings
  29. CONTRIBUTING.md
  30. DEPS
  31. LICENSE
  32. PATENT_GRANT
  33. PRESUBMIT.py
  34. README.dart-sdk
  35. README.md
  36. sdk_args.gni
  37. WATCHLISTS
README.md

Dart

A client-optimized language for fast apps on any platform

Dart is:

  • Optimized for UI: Develop with a programming language specialized around the needs of user interface creation

  • Productive: Make changes iteratively: use hot reload to see the result instantly in your running app

  • Fast on all platforms: Compile to ARM & x64 machine code for mobile, desktop, and backend. Or compile to JavaScript for the web

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, getting started, and more.

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

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 on our wiki.

Contributing to Dart

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

You can also contribute patches, as described in Contributing.