/* Checking macros for select functions. Copyright (C) 2011-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, see . */ #ifndef _SYS_SELECT_H # error "Never include directly; use instead." #endif /* Helper functions to issue warnings and errors when needed. */ extern long int __fdelt_chk (long int __d); extern long int __fdelt_warn (long int __d) __warnattr ("bit outside of fd_set selected"); #undef __FD_ELT #define __FD_ELT(d) \ __extension__ \ ({ long int __d = (d); \ (__builtin_constant_p (__d) \ ? (0 <= __d && __d < __FD_SETSIZE \ ? (__d / __NFDBITS) \ : __fdelt_warn (__d)) \ : __fdelt_chk (__d)); })