ABI Breaks

This document lists the ABI breaks that were made in each mlibc major version.

Version 4

#814: struct timex's long int tai changed to the correct int tai, and int __padding[11] got appended to the struct.
#816: sys_wait4 on Linux now correctly returns a pid_t, not an int as previously.
#816: All MS_* macros of the sys/mount.h header were adjusted to match linux.
#816: struct epoll_event now gets correctly packed on x86_64.
#819: str(n)dupa is now defined as a pure macro, and not as a macro that points to a function.
#828: Linux-specific functions previously included in the posix option in pthreads.h and sched.h are not correctly guarded behind the linux option.
#828: The CPU_* macros of sched.h have been rewritten to resolve to internal mlibc implementations, and are now correctly guarded behind the linux option.
#735: sched_getcpu and setns were previously mistakenly C++-mangled and not declared, which has now been rectified.

#728: The macros CMSG_{LEN,SPACE,DATA} were not accounting for padding between struct cmsghdr and it's respective data. This manifested itself as some parts of control data being skipped on platforms where struct cmsghdr is not divisible by alignof(size_t).
#452: The functions FD_{CLR,ISSET,SET,ZERO} were renamed to __FD_{CLR,ISSET,SET,ZERO} and replaced by macros to match Wine's assumptions.
#511: Musl's regex engine was added, implementing regcomp and regexec. This required some changes to the regex_t struct.
#504: In the Linux ABI, a domainname member was added to struct utsname, which is a glibc extension.
#311: Added all necessary fields in pthread_attr_t required for implementing all pthread_attr functions.
#652: The ABI of struct statfs and struct statvfs was changed to match Linux. socklen_t was also changed from unsigned long to unsigned int.
#658: In the Linux ABI, cc_t was changed from an unsigned int to an unsigned char.
#679: The struct glob_t received some additional members to bring it up to par with glibc.