Future-proof the kevent ABI #1572
Conversation
FreeBSD 12 adds some new private fields to struct kevent, and it changes the type of "data" from intptr_t to i64. For now libc only binds the 11-compat ABI, but that will change some day. Adjust mio's structure definitions for compatibility with either ABI. This should work on all 32 and 64 bit platforms.
| target_os = "ios", | ||
| target_os = "macos" | ||
| ))] | ||
| type Data = libc::intptr_t; |
There was a problem hiding this comment.
DragonFlyBSD and MacOS (and likely iOS) still use intptr_t in the manual. I think to be safe we should stick to that as well. You can just move FreeBSD down to NetBSD and OpenBSD.
There was a problem hiding this comment.
Except that FreeBSD 11 also still uses intptr_t. And currently there's no way for a crate to select which libc ABI it wants to use. So by removing that type entirely we'll just rely on type inference.
There was a problem hiding this comment.
But you're using as i64 in multiple places below, so it doesn't use type interference.
There was a problem hiding this comment.
Yeah. I changed the argument type of kevent_register to use i64 everywhere, instead of being platform-dependent. So now there's only one place that needs type inference: line 284 (and line 61, before my second commit). Those are the only places that actually use the libc type.
| @@ -60,6 +49,7 @@ macro_rules! kevent { | |||
| fflags: 0, | |||
| data: 0, | |||
| udata: $data as UData, | |||
| ..unsafe { mem::zeroed() } | |||
There was a problem hiding this comment.
Could you add a note that this is needed for FreeBSD?
There was a problem hiding this comment.
Sure. Except, looking at it again, I realize that I should've just deleted the fflags and data field initializers.
|
Thanks @asomers. |
FreeBSD 12 adds some new private fields to struct kevent, and it changes
the type of "data" from intptr_t to i64. For now libc only binds the
11-compat ABI, but that will change some day. Adjust mio's structure
definitions for compatibility with either ABI.
This should work on all 32 and 64 bit platforms.