dnl CF_RECHECK_FUNC version: 3 updated: 2000/10/18 19:29:13
dnl ---------------
dnl Re-check on a function to see if we can pick it up by adding a library.
dnl	$1 = function to check
dnl	$2 = library to check in
dnl	$3 = environment to update (e.g., $LIBS)
dnl	$4 = what to do if this fails
dnl
dnl This uses 'unset' if the shell happens to support it, but leaves the
dnl configuration variable set to 'unknown' if not.  This is a little better
dnl than the normal autoconf test, which gives misleading results if a test
dnl for the function is made (e.g., with AC_CHECK_FUNC) after this macro is
dnl used (autoconf does not distinguish between a null token and one that is
dnl set to 'no').
AC_DEFUN([CF_RECHECK_FUNC],[
AC_CHECK_LIB($2,$1,[
	CF_UPPER(cf_tr_func,$1)
	AC_DEFINE_UNQUOTED(HAVE_$cf_tr_func)
	ac_cv_func_$1=yes
	if test "$cf_used_lib_$2" != yes ; then cf_used_lib_$2=yes; $3="-l$2 [$]$3"; fi],[
	ac_cv_func_$1=unknown
	unset ac_cv_func_$1 2>/dev/null
	$4],
	[[$]$3])
])dnl
