mhd_assume.h (3146B)
1 /* SPDX-License-Identifier: LGPL-2.1-or-later OR (GPL-2.0-or-later WITH eCos-exception-2.0) */ 2 /* 3 This file is part of GNU libmicrohttpd. 4 Copyright (C) 2025 Evgeny Grin (Karlson2k) 5 6 GNU libmicrohttpd is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 GNU libmicrohttpd is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 Alternatively, you can redistribute GNU libmicrohttpd and/or 17 modify it under the terms of the GNU General Public License as 18 published by the Free Software Foundation; either version 2 of 19 the License, or (at your option) any later version, together 20 with the eCos exception, as follows: 21 22 As a special exception, if other files instantiate templates or 23 use macros or inline functions from this file, or you compile this 24 file and link it with other works to produce a work based on this 25 file, this file does not by itself cause the resulting work to be 26 covered by the GNU General Public License. However the source code 27 for this file must still be made available in accordance with 28 section (3) of the GNU General Public License v2. 29 30 This exception does not invalidate any other reasons why a work 31 based on this file might be covered by the GNU General Public 32 License. 33 34 You should have received copies of the GNU Lesser General Public 35 License and the GNU General Public License along with this library; 36 if not, see <https://www.gnu.org/licenses/>. 37 */ 38 39 /** 40 * @file src/mhd2/mhd_assume.h 41 * @brief The definition of the mhd_ASSUME() macro 42 * @author Karlson2k (Evgeny Grin) 43 */ 44 45 #ifndef MHD_ASSUME_H 46 #define MHD_ASSUME_H 1 47 48 #include "mhd_sys_options.h" 49 50 #if !defined(NDEBUG) 51 # include "mhd_assert.h" 52 #elif !defined(MHD_ASSUME_KEYWORD) && defined(MHD_UNREACHABLE_KEYWORD) 53 # include "mhd_unreachable.h" 54 #endif 55 56 /** 57 * mhd_ASSUME() should be used in locations where the given statement is known 58 * in advance to be always 'true'. 59 * It gives the compiler a hint that it may assume the statement to be true, 60 * helping it to optimise the code (for example, to drop impossible branches). 61 * In debug builds this macro is converted to assert() to ensure that the 62 * expectation is always correct. 63 * The statement must have no side effects: it may not be evaluated at all in 64 * non-debug builds. 65 */ 66 #ifdef NDEBUG 67 # ifdef MHD_ASSUME_KEYWORD 68 # define mhd_ASSUME(statement) MHD_ASSUME_KEYWORD ((statement)) 69 # elif defined(MHD_UNREACHABLE_KEYWORD) 70 # define mhd_ASSUME(statement) \ 71 do { if (! (statement)) mhd_UNREACHABLE (); } while (0) 72 # else 73 # define mhd_ASSUME(statement) ((void) 0) 74 # endif 75 #else 76 # define mhd_ASSUME(statement) \ 77 mhd_assert ((statement) && "This statement must be always 'true'") 78 #endif 79 80 #endif /* ! MHD_ASSUME_H */