ABI Breaks

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

Version 3

#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.