1 /* Checking macros for select functions. 2 Copyright (C) 2011-2022 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 <https://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. */ 24 extern long int __fdelt_chk (long int __d); 25 extern 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