1/* Checking macros for select functions.
2 Copyright (C) 2011-2018 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19#ifndef _SYS_SELECT_H
20# error "Never include <bits/select2.h> directly; use <sys/select.h> instead."
21#endif
22
23/* Helper functions to issue warnings and errors when needed. */
24extern long int __fdelt_chk (long int __d);
25extern long int __fdelt_warn (long int __d)
26 __warnattr ("bit outside of fd_set selected");
27#undef __FD_ELT
28#define __FD_ELT(d) \
29 __extension__ \
30 ({ long int __d = (d); \
31 (__builtin_constant_p (__d) \
32 ? (0 <= __d && __d < __FD_SETSIZE \
33 ? (__d / __NFDBITS) \
34 : __fdelt_warn (__d)) \
35 : __fdelt_chk (__d)); })
36