Hi All,
I posted a message to the Cygwin developers list asking if anyone had an
objection to doing this. Since noone expressed any, I think we should enable
this since it will enhance our printf and improve compatibility w.r.t. sources
from other *nixes. As mentioned before in my message to the devel list, it
also is specifed as a standard for Unix98. However, I was required to fix what
appeared to be a typo in vfprintf.c for %n when the argument is a long long.
The pointer quad_ptr_t was already defined with the *, so the extra * after
quad_ptr_t is extraneous and causes the CPP concatination to fail when
positional args are enabled.
In any event, after fixing that up, I sucessfully compiled the Cygwin dll. I
ran a few tests, including some portions of the glibc printf test. The results
were as expected and confirmed that positional arguments were functioning
properly. For reference, I have attached a small, working testcase to
demonstrate postional arguments and prove they work on Cygwin. Also attached
is the patch adding -DWANT_IO_POS_ARGS to Cygwin's line in configure.host and
fixing the aforementioned problem in vfprintf.c.
Of course, this is up to Chris or Corinna to approve, so I await their
comments/criticism.
Cheers,
Nicholas