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rust/rust/6f109d8a2da2fe8d0fbfc52178300c033737b218
commit
6f109d8a2da2fe8d0fbfc52178300c033737b218
[log]
author
bors <bors@rust-lang.org>
Sat Apr 18 23:46:37 2026 +0000
committer
bors <bors@rust-lang.org>
Sat Apr 18 23:46:37 2026 +0000
tree
68f8ed2a5b134b2f04b16ee397d5f17619921cad
parent
0febdbab2720dc0360cd294c67db88d6d06580d4 [diff]
parent
a70f37baa6ba8925e18771e1cf34ec2247246c48 [diff]
Auto merge of #155223 - teor2345:fndef-refactor, r=mati865

Refactor FnDecl and FnSig non-type fields into a new wrapper type





#### Why this Refactor?

This PR is part of an initial cleanup for the [arg splat experiment](https://github.com/rust-lang/rust/issues/153629), but it's a useful refactor by itself.

It refactors the non-type fields of `FnDecl`, `FnSig`, and `FnHeader` into a new packed wrapper types, based on this comment in the `splat` experiment PR:
https://github.com/rust-lang/rust/pull/153697#discussion_r3004637413

It also refactors some common `FnSig` creation settings into their own methods. I did this instead of creating a struct with defaults.

#### Relationship to `splat` Experiment

I don't think we can use functional struct updates (`..default()`) to create `FnDecl` and `FnSig`, because we need the bit-packing for the `splat` experiment.

Bit-packing will avoid breaking "type is small" assertions for commonly used types when `splat` is added.
This PR packs these types:
- ExternAbi: enum + `unwind` variants (38) -> 6 bits
- ImplicitSelfKind: enum variants (5) -> 3 bits
- lifetime_elision_allowed, safety, c_variadic: bool -> 1 bit

#### Minor Changes

Fixes some typos, and applies rustfmt to clippy files that got skipped somehow.
tree: 68f8ed2a5b134b2f04b16ee397d5f17619921cad
  1. .github/
  2. compiler/
  3. library/
  4. LICENSES/
  5. src/
  6. tests/
  7. .clang-format
  8. .editorconfig
  9. .git-blame-ignore-revs
  10. .gitattributes
  11. .gitignore
  12. .gitmodules
  13. .ignore
  14. .mailmap
  15. bootstrap.example.toml
  16. Cargo.lock
  17. Cargo.toml
  18. CODE_OF_CONDUCT.md
  19. configure
  20. CONTRIBUTING.md
  21. COPYRIGHT
  22. INSTALL.md
  23. LICENSE-APACHE
  24. license-metadata.json
  25. LICENSE-MIT
  26. package.json
  27. README.md
  28. RELEASES.md
  29. REUSE.toml
  30. rust-bors.toml
  31. rustfmt.toml
  32. triagebot.toml
  33. typos.toml
  34. x
  35. x.ps1
  36. x.py
  37. yarn.lock
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