mhd_cntnr_ptr.h (3865B)
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) 2024 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_cntnr_ptr.h 41 * @brief The definition of mhd_CNTNR_PTR() and mhd_CNTNR_CPTR() macros. 42 * @author Karlson2k (Evgeny Grin) 43 */ 44 45 #ifndef MHD_CNTNR_PTR_H 46 #define MHD_CNTNR_PTR_H 1 47 48 #include "mhd_sys_options.h" 49 50 #include "sys_base_types.h" 51 52 #include "sys_offsetof.h" 53 54 /** 55 * Get the pointer to the outer @a cntnr_type structure containing @a membr_name 56 * member by the @a membr_ptr pointer to the member. 57 * 58 * This macro checks at compile time whether pointer to the @a membr_name in 59 * the @a cntnr_type is compatible with the provided @a membr_ptr pointer. 60 * 61 * @param membr_ptr the pointer to the member 62 * @param cntnr_type the type of the container with the @a membr_name member 63 * @param membr_name the name of the member pointed by @a membr_ptr 64 * @return the pointer to the outer structure 65 */ 66 #define mhd_CNTNR_PTR(membr_ptr,cntnr_type,membr_name) \ 67 ((cntnr_type*) (void*) \ 68 (((char*) (0 ? \ 69 (&(((cntnr_type*) NULL)->membr_name)) : \ 70 (membr_ptr))) - offsetof (cntnr_type,membr_name))) 71 72 /** 73 * Get the const pointer to the outer @a cntnr_type structure 74 * containing @a membr_name member by the @a membr_ptr pointer to the member. 75 * 76 * This macro checks at compile time whether pointer to the @a membr_name in 77 * the @a cntnr_type is compatible with the provided @a membr_ptr pointer. 78 * 79 * @param membr_ptr the pointer to the member 80 * @param cntnr_type the type of the container with the @a membr_name member 81 * @param membr_name the name of the member pointed by @a membr_ptr 82 * @return the pointer to the outer structure 83 */ 84 #define mhd_CNTNR_CPTR(membr_ptr,cntnr_type,membr_name) \ 85 ((const cntnr_type*) (const void*) \ 86 (((const char*) (0 ? \ 87 (&(((cntnr_type*) NULL)->membr_name)) : \ 88 (membr_ptr))) - offsetof (cntnr_type,membr_name))) 89 90 #endif /* ! MHD_CNTNR_PTR_H */