dnl AC_TRY_LINK_MOD(INCLUDES, FUNCTION-BODY,
dnl             [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]])
AC_DEFUN(AC_TRY_LINK_MOD,
[cat > conftest.$ac_ext <<EOF
ifelse(AC_LANG, [FORTRAN77],
[
      program main
      call [$2]
      end
],
[dnl This sometimes fails to find confdefs.h, for some reason.
dnl [#]line __oline__ "[$]0"
[#]line __oline__ "configure"
#include "confdefs.h"
[$1]
int main() {
[$2]
; return 0; }
])EOF
if AC_TRY_EVAL(ac_link) && test -s conftest${ac_exeext}; then
  ifelse([$3], , :, [
  $3])
else
  echo "configure: failed program was:" >&AC_FD_CC
  cat conftest.$ac_ext >&AC_FD_CC
ifelse([$4], , , [  
  $4
])dnl
fi
rm -f conftest*])