depend on namespace pollution and as such become more portable. This
means including headers like <sys/types.h> or <stdlib.h>, but also
making sure we include system/host headers before local headers.
While here: define ENOATTR as ENOMSG in mtree.c. There is no ENOATTR
on Linux.
With this, makefs is ready for compilation on macOS and Linux.
- Let panic() use _Noreturn and __printflike() instead of GCC-specific
attributes.
- Remove prototype from ffs_subr.c and let it include ffs_extern.h.
- Forward declare struct inode to make ffs_extern.h not depend on it.
and usr.sbin/makefs/ffs/ffs_subr.c as they have no need of anything in that
file. No other programs or libraries include <ufs/ffs/ffs_extern.h> (nor
should they as it is totally in-kernel interfaces). For added protection
I enclosed the entire contents of <ufs/ffs/ffs_extern.h> in ifdef _KERNEL.
Feedback from: Bruce Evans and Tai-hwa Liang
