Re-export c_char_def as c_char instead of defining c_char per target

[taiki-e]

Description

Replaces #4199 by doing #4199 (comment).

Closes #4199.

Sources

Checklist

• Relevant tests in libc-test/semver have been updated
• No placeholder or unstable values like *LAST or *MAX are
  included (see #3131)
• Tested locally (cd libc-test && cargo test --target mytarget);
  especially relevant for platforms that may not be checked in CI

[rustbot]

r? @tgross35

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[taiki-e]

Hmm...

https://github.com/rust-lang/libc/actions/runs/12372572407/job/34531085124?pr=4201

src/teeos/mod.rs:12: import found after module when it belongs before
src/vxworks/riscv64.rs:3: typedef found after module when it belongs before
src/vxworks/aarch64.rs:3: typedef found after module when it belongs before
src/vxworks/riscv32.rs:3: typedef found after module when it belongs before
src/vxworks/x86_64.rs:3: typedef found after module when it belongs before
... (omitted)
src/unix/nto/aarch64.rs:2: import found after module when it belongs before
src/unix/nto/x86_64.rs:2: import found after module when it belongs before
src/wasi/mod.rs:9: import found after module when it belongs before

[rustbot]

Some changes occurred in solarish module

cc @jclulow, @pfmooney

Some changes occurred in OpenBSD module

cc @semarie

[tgross35]

Hmm...

https://github.com/rust-lang/libc/actions/runs/12372572407/job/34531085124?pr=4201

src/teeos/mod.rs:12: import found after module when it belongs before
src/vxworks/riscv64.rs:3: typedef found after module when it belongs before
src/vxworks/aarch64.rs:3: typedef found after module when it belongs before
src/vxworks/riscv32.rs:3: typedef found after module when it belongs before
src/vxworks/x86_64.rs:3: typedef found after module when it belongs before
... (omitted)
src/unix/nto/aarch64.rs:2: import found after module when it belongs before
src/unix/nto/x86_64.rs:2: import found after module when it belongs before
src/wasi/mod.rs:9: import found after module when it belongs before

This repo has really old tooling that likes to complain about a lot. It might need a fix if it's not reporting something accurately.

My idea with having c_char_def is that I could go through one OS at a time and double check that things line up, replacing arch-specific type c_chars = ... in e.g. some_os/{aarch64,x86_64,arm}.rs with a pub use crate::arch::c_char_def as c_char; in some_os/mod.rs if things line up. Unfortunately I don't think that changing from definitions to reexports really highlights any remaining discrepancies.

Admittedly this plan was from before I knew anyone else was working on this so I am open to other suggestions, but could at least the known changes in #4199 get in before updating everything else?

[taiki-e]

(The approach I said I think is ideal in #4199 (comment), doesn't have such an CI problem: #4202)

[taiki-e]

Closing in favor of #4202, which is doing the approach I said I think is ideal in #4199 (comment).