WTERMSIG (and others) are unsafe on macOS, but safe on Linux

[Thomasdezeeuw]

WTERMSIG and related functions have been changed to no longer require unsafe, seemingly in commit 5a1df22. However on macOS these functions are still unsafe. See the definition on Linux https://docs.rs/libc/0.2.77/libc/fn.WTERMSIG.html (no unsafe) vs. macOS https://docs.rs/libc/0.2.77/x86_64-apple-darwin/libc/fn.WTERMSIG.html (requires unsafe). Was it intentional to leave macOS out?

Also this causes warnings, e.g. see https://github.com/rust-lang/rust/pull/76561/checks?check_run_id=1096958697#step:23:213 (https://github.com/rust-lang/rust/commit/7c3e1ffd7a945b4044e5e80d7d74ba944ff54d0f/checks/1096958697/logs).

/cc @joshtriplett who wrote the commit.

[joshtriplett]

It's not that I intentionally left macOS out, I just didn't go changing any other targets systematically in that first commit. Now that the infrastructure is in place, by all means we should update various other functions to use it, including on other targets.

And yes, I'm not surprised that this resulted in "unused unsafe" warnings. We should prioritize adding this to matching functions for other targets, to avoid having problems where one target wants unsafe and another doesn't.

[joshtriplett]

773f556 should fix this on all platforms. The fix should be available in the next release of the libc crate.

[xmo-odoo]

@joshtriplett @Thomasdezeeuw rustc's Cargo.lock pins to 0.2.85 which was released on Feb. 2, 2021. The unsafe blocks & warning suppressions are still present in the latest rustc, are they still necessary?

[Thomasdezeeuw]

@xmo-odoo @joshtriplett did that in rust-lang/rust@16ebf75.

[xmo-odoo]

@Thomasdezeeuw

did that in rust-lang/rust@16ebf75.

Uh. Weird, I wonder what I fucked up that I apparently reached an outdated revision (through the github search according to my browser history, but now it links to an up-to-date one).

Sorry about that.