| commit | eec56c088efc2e0b982cc84b5b6a0102ff9df8dc | [log] [tgz] |
|---|---|---|
| author | Paul Berry <paulberry@google.com> | Wed Jun 04 05:17:21 2025 -0700 |
| committer | Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> | Wed Jun 04 05:17:21 2025 -0700 |
| tree | af6827a2fa4c602ce45b71e83e0b633e890b0480 | |
| parent | 27952c536839aee47e8d2f8a898c692f666dd541 [diff] |
[flow analysis] Mark `false` branches of trivial `is` tests unreachable. When an `is` test is trivially satisfied (i.e. `expr is T`, when the static type of `expr` is a subtype of `T`), the `is` test is guaranteed by soundness to evaluate to `true`, so any code path that follows from the `is` test evaluating to `false` is unreachable. This reasoning wasn't valid prior to sound null safety, because in mixed mode programs, it was possible for an expression to evaluate to `null` even if its static type wasn't nullable, and hence `expr is T` might evaluate to `false` even if the static type of `expr` was a subtype of `T`. So this change is gated on the `sound-flow-analysis` language flag (which is enabled in Dart 3.9). Fixes https://github.com/dart-lang/sdk/issues/60718. Change-Id: I66a65580b738162f23b6fb468b71fcac66bfbb95 Bug: https://github.com/dart-lang/sdk/issues/60718 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/431740 Commit-Queue: Paul Berry <paulberry@google.com> Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
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 is free and open source.
See LICENSE and PATENT_GRANT.
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).
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.
The easiest way to contribute to Dart is to file issues.
You can also contribute patches, as described in Contributing.
Future plans for Dart are included in the combined Dart and Flutter roadmap on the Flutter wiki.