Currently we have both EOPNOTSUPP ("Operation not supported") and
ENOTSUP ("Not supported") errnos. EOPNOTSUPP is historical; ENOTSUP
was randomly added by POSIX relatively recently.
And lately I've noticed a tendency to conflate them, which isn't
healthy.
It is too late to do #define ENOTSUP EOPNOTSUPP (although we could do
this as part of the mythical libc major version bump to happen
Sometime(TM)) but I think we should take steps to prevent any more
confusion than already exists:
- do not add new uses of ENOTSUP except where specifically mandated
by POSIX;
- avoid creating interfaces where ENOTSUP and EOPNOTSUPP are both
expected error conditions (and remove any that have crept in);
- mention this in errno(2);
- also add a notice to this effect somewhere it will be seen
(although I have no idea where that would be);
Alternatively we could try to articulate a distinction between them
and adjust the messages to match; but I'm not sure this is compatible
with the mandated behavior.
Thoughts anyone?
--
David A. Holland
dholl...@netbsd.org
