[dart2wasm] Unify deferred loading implementation

This CL does a few things

* only have one way to lower deferred loading constructs
* only have one runtime implementation
* only use load ids now and refer to them as integers instead of strings
* remove AST repository for load ids (no need to serialize them across
  kernel serialization - as we assign them during codegen phase now)
* make runtime metadata smaller for deferred loading (wasm arrays)
* inject the loading map (runtime data structure) after codegen
* it fixes the stress test module strategy to inject `LoadLibrary`
  AST nodes (as the CFE does) instead of calls to the lowered form

Overall this simplifies the code significantly, removes complexity &
code from the codebase.

This refactoring opens up for the possibility for the codegen phase
to add more modules (e.g. if two deferred modules use the same constant,
we could *create* module to contain them).

Closes https://github.com/dart-lang/sdk/issues/61844
Issue https://github.com/dart-lang/sdk/issues/61727

Change-Id: Idfefee25d5f84f8717808a0aee1b189d8f15d16d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/458000
Reviewed-by: Nate Biggs <natebiggs@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
19 files changed
tree: 0146adf3dac089aa47448ec24f9c2463820396b0
  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

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See LICENSE and PATENT_GRANT.

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