-AC_HEADER_DIRENT
-
-# This must be after CPP
-
-AC_CACHE_CHECK(which header file defines FD_ macros, s51_cv_fd,
-[sdcc_cv_fd="unknown"
-AC_EGREP_CPP(yes, [
-#include <sys/time.h>
-#ifdef FD_ZERO
-yes
-#endif], sdcc_cv_fd="<sys/time.h>")
-AC_EGREP_CPP(yes, [
-#include <sys/types.h>
-#ifdef FD_ZERO
-yes
-#endif], sdcc_cv_fd="<sys/types.h>")
-AC_EGREP_CPP(yes, [
-#include <sys/select.h>
-#ifdef FD_ZERO
-yes
-#endif], sdcc_cv_fd="<sys/types.h>")])
-
-AC_DEFINE(FD_HEADER_OK, 0)
-if echo $sdcc_cv_fd|grep time >/dev/null 2>&1; then
-AC_DEFINE(FD_NEED_TIME_H, 1)
-AC_DEFINE(FD_HEADER_OK, 1)
-else
-AC_DEFINE(FD_NEED_TIME_H, 0)
-fi
-if echo $sdcc_cv_fd|grep types >/dev/null 2>&1; then
-AC_DEFINE(FD_NEED_TYPES_H, 1)
-AC_DEFINE(FD_HEADER_OK, 1)
-else
-AC_DEFINE(FD_NEED_TYPES_H, 0)
-fi
-if echo $sdcc_cv_fd|grep select >/dev/null 2>&1; then
-AC_DEFINE(FD_NEED_SELECT_H, 1)
-AC_DEFINE(FD_HEADER_OK, 1)
-else
-AC_DEFINE(FD_NEED_SELECT_H, 0)
-fi
-
-AC_DEFINE_UNQUOTED(HEADER_FD, ${sdcc_cv_fd})