AC_PROG_CC_C99 and -std=c99

['Chris Hall']

I have been going mano-a-mano with configure.ac for the Quagga suite.

It seemed to me to be a Good Thing to stick as far as possible to
standard C99 (and, for that matter, POSIX).

Disappointingly, AC_PROG_CC_C99 seems to prefer -std=gnu99 or any
other *extended* C99 compiler support.

It looks as though AC_PROG_CC_STDC is essentially a synonym for
AC_PROG_CC_C99.

So, my first question is: am I mistaken in thinking that using
-std=c99 will help, portability-wise ?

And, if not, is there a place for a AC_PROG_CC_STD_C99 ?

Chris
-- 
Chris Hall,  Highwayman.