1 /* Checking macros for select functions. 2 Copyright (C) 2011 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, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 02111-1307 USA. */ 19 20 #ifndef _SYS_SELECT_H 21 # error "Never include <bits/select2.h> directly; use <sys/select.h> instead." 22 #endif 23 24 /* Helper functions to issue warnings and errors when needed. */ 25 extern unsigned long int __fdelt_chk (unsigned long int __d); 26 extern unsigned long int __fdelt_warn (unsigned long int __d) 27 __warnattr ("bit outside of fd_set selected"); 28 #undef __FD_ELT 29 #define __FD_ELT(d) \ 30 __extension__ \ 31 ({ unsigned long int __d = (d); \ 32 (__builtin_constant_p (__d) \ 33 ? (__d >= __FD_SETSIZE \ 34 ? __fdelt_warn (__d) : (__d / __NFDBITS)) \ 35 : __fdelt_chk (__d)); }) 36
