Define _POSIX_C_SOURCE globally · 842093bbSimon Ser authored
Stop trying to maintain a per-file _POSIX_C_SOURCE. Instead, require POSIX.1-2008 globally. A lot of core source files depend on that already. Some care must be taken on a few select files where we need a bit more than POSIX. Some files need XSI extensions (_XOPEN_SOURCE) and some files need BSD extensions (_DEFAULT_SOURCE). In both cases, these feature test macros imply _POSIX_C_SOURCE. Make sure to not define both these macros and _POSIX_C_SOURCE explicitly to avoid POSIX requirement conflicts (e.g. _POSIX_C_SOURCE says POSIX.1-2001 but _XOPEN_SOURCE says POSIX.1-2008). Additionally, there is one special case in render/vulkan/vulkan.c. That file needs major()/minor(), and these are system-specific. On FreeBSD, _POSIX_C_SOURCE hides system-specific symbols so we need to make sure it's not defined for this file. On Linux, we can explicitly include <sys/sysmacros.h> and ensure that apart from symbols defined there the file only uses POSIX toys.