| 1 | /* Checking macros for select functions. |
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| 2 | Copyright (C) 2011-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _SYS_SELECT_H |
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| 20 | # error "Never include <bits/select2.h> directly; use <sys/select.h> instead." |
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| 21 | #endif |
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| 22 | |
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| 23 | /* Helper functions to issue warnings and errors when needed. */ |
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| 24 | extern long int __fdelt_chk (long int __d); |
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| 25 | extern long int __fdelt_warn (long int __d) |
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| 26 | __warnattr ("bit outside of fd_set selected" ); |
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| 27 | #undef __FD_ELT |
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| 28 | #define __FD_ELT(d) \ |
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| 29 | __extension__ \ |
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| 30 | ({ long int __d = (d); \ |
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| 31 | (__builtin_constant_p (__d) \ |
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| 32 | ? (0 <= __d && __d < __FD_SETSIZE \ |
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| 33 | ? (__d / __NFDBITS) \ |
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| 34 | : __fdelt_warn (__d)) \ |
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| 35 | : __fdelt_chk (__d)); }) |
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| 36 | |
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