All function pointer types should be `Option<unsafe extern "C" fn(...) -> ...>`

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@Deepak-negi11 is already working on this.

Since Oct 10, 2026.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
65/100
Issue type
Feature
Clarity
Mostly clear
Activity status
Quiet
Tech stack
rust
Domain
tooling

Research direction

Start by reading the style.rs checks and the related examples in issue #2198 and pull request #4341. Extend the checks to enforce Option<unsafe extern "C" fn(...) -> ...> for all function pointer types, covering the nullability, safety, and calling-convention requirements described in the issue.

Written by the indexing model from the issue text.

Description

https://github.com/rust-lang/libc/issues/2198 falls into this category, and https://github.com/rust-lang/libc/pull/4341 fixes at least a subset. We should enforce this rule in the style.rs checks.

Three things here:

  1. Option because API may allow a null pointer
  2. unsafe because functions may have side effects or be invalid pointers (https://github.com/rust-lang/libc/issues/4998 for a proposal to adjust the second part)
  3. extern "C" because that's what the C side expects
Dominant language
Rust
Stars
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Forks
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Avg merge
2d 13h
Merged PRs (30d)
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Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

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