Missing bindings of sys/syscall.h

[marmistrz]

At least on glibc 2.25 there's a header sys/syscall.h which defines all the syscall numbers by name. It effectively includes asm/unistd_64.h (on x86_64) which is structured like this:

#define __NR_read 0
#define __NR_write 1
#define __NR_open 2

and bits/syscall.h, which does something like this:

#define SYS_write __NR_write

I don't insist on 1-1 binding but I believe we should have a syscall registry in Rust. Currently, every Rust application that uses seccomp or ptrace has to hardcode the syscall numbers.

Btw. do you think that such thing should be a part of the libc crate or rather an external crate such as https://github.com/nix-rust/nix ?

[alexcrichton]

PRs are of course always welcome! There's no reason these haven't been added other than no one's gotten around to doing it yet.

[marmistrz]

So let's find a cute name for that... :)
What about libc::syscall_num::write for getting the number of write syscall?

[alexcrichton]

Oh we should just stick to the libc names, not invent new names.

[marmistrz]

Ok, so which of two names: SYS_write or __NR_write? Both of them are available, as mentioned in the first post.

[marmistrz]

Fixed by #672