I was wondering if it is possible (and whether it is a good idea in general) autoconf to print warnings for extra macro arguments instead of silently ignoring them.
Minimalistic example (from https://savannah.gnu.org/bugs/index.php?30766): AC_INIT AC_CHECK_HEADERS(pthread.h,, [AC_MSG_ERROR([Unable to find pthread.h.])]) AC_CHECK_ALIGNOF(pthread_mutex_t,,[AC_INCLUDES_DEFAULT #include <pthread.h>]) AS_IF([test -z $ac_cv_alignof_pthread_mutex_t], [AC_MSG_ERROR([Unable to determine alignment of pthread_mutex_t.])]) AC_OUTPUT The generated configure script fails on OpenBSD and Woe32, because <pthread.h> is not #include'd in the test program. It took me some time to spot where the problem is :-)
