AC_DEFUN(BISON_WARNING,
[AC_MSG_CHECKING(whether compiler accepts $1)
AC_SUBST(WARNING_CFLAGS)
ac_save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS $1"
AC_TRY_COMPILE(,
[int x;],
WARNING_CFLAGS="$WARNING_CFLAGS $1"
AC_MSG_RESULT(yes),
AC_MSG_RESULT(no))
CFLAGS="$ac_save_CFLAGS"])