[dart/vm] Replaces eager with lazy reading of constants table

Rationale:
Previously all constants were read from the constants table,
whether they were needed (at that point or at all) or not. This
CL replaces that eager reading with a lazy reading that makes
the raw bytes of the constants table available through
KernelProgramInfo and attaches a hashmap to KernelProgramInfo,
which maps offsets into the constant table to evaluated constants.
The maps starts empty and on a miss, the constant is evaluated,
but no sooner than when it it needed.

https://github.com/dart-lang/sdk/issues/36220

Change-Id: Ief4df3d70c950c4beb61d896632ce06cfd12d525
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/99088
Commit-Queue: Aart Bik <ajcbik@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
12 files changed
tree: 37fb870cb18bdaabe9b70626b17aee221bbfc719
  1. .clang-format
  2. .gitattributes
  3. .gitconfig
  4. .github/
  5. .gitignore
  6. .gn
  7. .mailmap
  8. .packages
  9. .vpython
  10. AUTHORS
  11. BUILD.gn
  12. CHANGELOG.md
  13. CONTRIBUTING.md
  14. DEPS
  15. LICENSE
  16. PATENTS
  17. PRESUBMIT.py
  18. README.dart-sdk
  19. README.md
  20. WATCHLISTS
  21. build/
  22. client/
  23. codereview.settings
  24. docs/
  25. pkg/
  26. runtime/
  27. samples-dev/
  28. samples/
  29. sdk/
  30. tests/
  31. third_party/
  32. tools/
  33. utils/
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 has 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 PATENTS.

Using Dart

Visit the 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.

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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.

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You can also contribute patches, as described in Contributing.