Linux: add getitimer()/setitimer()
#3847
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r? @JohnTitor rustbot has assigned @JohnTitor. Use |
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| cfg_if! { | ||
| if #[cfg(target_env = "musl")] { | ||
| extern "C" { | ||
| pub fn getitimer(which: ::c_int, value: *mut ::itimerval) -> ::c_int; |
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not sure I follow, why not using the typedef you created above ?
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This is the result of a strange combination of issues. glibc and most other libc implementations typedef __itimer_which_t as an enum when _GNU_SOURCE is set, or as an int otherwise. musl unfortunately opts to just use an int directly within the function definitions for getitimer and setitimer. As a result of this:
- Using
__itimer_whiich_tdirectly in function definitions causes musl CI to fail as it's not a defined type - Removing
__itimer_which_taltogether for musl builds still causes CI to fail, as there is currently no way of opting out ofenumsemver checks (you can opt out forstructs,types, everything else butenums)
By defining __itimer_which_t as a type definition in musl and then opting out of it, CI passes.
A more clean solution to this may be to develop enum opt-out functions to the ctest2 crate.
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Another possible approach is not to bother with enums at all.
pub type __itimer_which_t = ::c_int;
...
pub const ITIMER_REAL: __itimer_which_t = 0;
...There are various places in this crate were C enums are handled as simple constants. Should pass in theory.
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r? @tgross35 |
| cfg_if! { | ||
| if #[cfg(target_env = "musl")] { | ||
| pub type __itimer_which_t = ::c_int; | ||
| } else { | ||
| pub type __itimer_which_t = ::c_uint; | ||
| } | ||
| } |
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glibc has int when it is not defined as an enum, and musl doesn't seem to define this type at all - why is the definition done this way?
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Ah nevermind, I see the reasoning below. I think we need to work with one of the ways that doesn't expose this on musl.
In general it is probably better to avoid Rust enums to represent C types at all, given how easy it is to cause UB. So some sort of solution that just typedefs an int on glibc seems preferable to me.
Resolves #1347