Fine. Compute and persist LibraryManifest.hashForRequirements

Introduce a stable, order-independent hash derived from exactly the
parts of a library manifest that the requirements checker reads. This
hash is stored on each `LibraryManifest` (`hashForRequirements`) and
serialized as part of the binary format. When unchanged, it serves as a
fast path to skip the detailed `RequirementsManifest.isSatisfied` walk;
when it differs, the full check is re-run.

Key details:
- Hash content covers:
  - Library identity and flags (name, `isSynthetic`, `featureSet`),
    language versions (package/override), and `libraryMetadata.id`.
  - Export surface (sorted `exportedLibraryUris`, re-export
    `deprecatedOnly` names).
  - All declared top-level items; for instance/Interface items also hash
    members, inherited constructors, `hasNonFinalField`, and the
    interface id.
  - Export map id and entries, and exported extension ids.
- Determinism is ensured by sorting map entries by `LookupName` and
  lists before hashing.
- New helpers on `ApiSignature` (`addList`, `addMapEntryList`) simplify
  writing length-prefixed sequences.
- The manifest printer now shows the requirements hash as a compact
  `#H*` identifier to aid debugging.
- Binary format change bumps `AnalysisDriver.DATA_VERSION` to 563.

This change provides a cheap, deterministic indicator for whether a
library’s manifest remains equivalent for requirements checking,
reducing unnecessary revalidation while preserving correctness.

Change-Id: If00778bac077e2bd36a480ca0475ad356bc1d822
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/451663
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
5 files changed
tree: 44ecefde0d0d6cd5fbc24dc5a89bb092d7a4c121
  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. pubspec.yaml
  32. README.dart-sdk
  33. README.md
  34. sdk.code-workspace
  35. sdk_args.gni
  36. sdk_packages.yaml
  37. SECURITY.md
  38. 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.