Duplicate std::os::raw in core? (original) (raw)

Since the types in std::os::raw are not also in core, there’s no way to use them from a no-std program. Among other things, this is an issue for bindgen.

Is there a reason we should add a similar module to core (and maybe make the std types aliases for those)?

mcy July 29, 2018, 9:16pm 2

I was going to saw “but wait OsString is alloc!” but, as always, I forget it’s in std::ffi, not std::os. Those are all type aliases (except c_void which is special), so moving them to core is probably a trivial change.

emilio July 30, 2018, 12:15am 3

Since the types in std::os::raw are not also in core, there’s no way to use them from a no-std program. Among other things, this is an issue for bindgen.

FWIW, there is a way to use it from a #[no_std] program, which is using the libc crate, or at least that's the way you used to be able to do it IIRC . That's why bindgen has two different options, one to use core, and another to add a prefix for C-types, which usually is libc.

It's not the first report about this being confusing, so a nicer solution would be really appreciated. Though that may mean more requirements for #[no_std] targets which also don't need C types? Not sure about the trade-off here.

joshlf July 30, 2018, 12:21am 4

Ah, I see. That's a good point.

I don't think it introduces any extra requirements since none of these are extern declarations. They just happen to have the same memory layout as the equivalent C types.

I've put up a PR here.

New RFC to propose doing this for c_void (only, for now): https://github.com/rust-lang/rfcs/pull/2521

system Closed March 25, 2019, 8:30am 6

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