This only shows in release mode, the compiler tries to preserve some
value in rdi, but that gets replaced inside the fiber. This would not
happen in the C calling convention, but in these normal Zig functions,
it can happen.
In the future, it might be nice to introduce a type for file system path
names. This would be a way to avoid having InvalidFileName in the error
set, since construction of such type could validate it above the
interface.
Calling recvmsg first means no poll syscall needed when messages are
already in the operating system queue. Empirically, this happens when
repeating a DNS query that has been already been made recently. In such
case, poll() is never called!
glibc and linux kernel use size_t for some field lengths while POSIX and
musl use int. This bug would have caused breakage the first time someone
tried to call sendmsg on a 64-bit big endian system when linking musl
libc.
my opinion:
* msghdr.iovlen: kernel and glibc have it right. This field should
definitely be size_t. With int, the padding bytes are wasted for no
reason.
* msghdr.controllen: POSIX and musl have it right. 4 bytes is plenty for
the length, and it saves 4 bytes next to flags.
* cmsghdr.len: POSIX and musl have it right. 4 bytes is plenty for the
length, and it saves 4 bytes since the other fields are also 32-bits
each.
The one about INT_MAX is self-evident from the type system.
The one about kernel having bad types doesn't seem accurate as I checked
the source code and it uses size_t for all the appropriate types,
matching the libc struct definition for msghdr and msghdr_const.
extract pure functional logic into pure functions and then layer the
scope crap on top properly
the formatting code incorrectly didn't do the reverse operation
(if_indextoname). fix that with some TODO panics
