| 1 | /* Interface to byteswapping functions. |
| 2 | Copyright (C) 2006-2021 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of libctf. |
| 5 | |
| 6 | libctf is free software; you can redistribute it and/or modify it under |
| 7 | the terms of the GNU General Public License as published by the Free |
| 8 | Software Foundation; either version 3, or (at your option) any later |
| 9 | version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, but |
| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 14 | See the GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; see the file COPYING. If not see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #ifndef _CTF_SWAP_H |
| 21 | #define _CTF_SWAP_H |
| 22 | |
| 23 | #include "config.h" |
| 24 | #include <stdint.h> |
| 25 | #include <assert.h> |
| 26 | |
| 27 | #ifdef HAVE_BYTESWAP_H |
| 28 | #include <byteswap.h> |
| 29 | #endif /* defined(HAVE_BYTESWAP_H) */ |
| 30 | |
| 31 | /* Provide our own versions of the byteswap functions. */ |
| 32 | |
| 33 | #if !HAVE_DECL_BSWAP_16 |
| 34 | static inline uint16_t |
| 35 | bswap_16 (uint16_t v) |
| 36 | { |
| 37 | return ((v >> 8) & 0xff) | ((v & 0xff) << 8); |
| 38 | } |
| 39 | #endif /* !HAVE_DECL_BSWAP16 */ |
| 40 | |
| 41 | #if !HAVE_DECL_BSWAP_32 |
| 42 | static inline uint32_t |
| 43 | bswap_32 (uint32_t v) |
| 44 | { |
| 45 | return ( ((v & 0xff000000) >> 24) |
| 46 | | ((v & 0x00ff0000) >> 8) |
| 47 | | ((v & 0x0000ff00) << 8) |
| 48 | | ((v & 0x000000ff) << 24)); |
| 49 | } |
| 50 | #endif /* !HAVE_DECL_BSWAP32 */ |
| 51 | |
| 52 | #if !HAVE_DECL_BSWAP_64 |
| 53 | static inline uint64_t |
| 54 | bswap_64 (uint64_t v) |
| 55 | { |
| 56 | return ( ((v & 0xff00000000000000ULL) >> 56) |
| 57 | | ((v & 0x00ff000000000000ULL) >> 40) |
| 58 | | ((v & 0x0000ff0000000000ULL) >> 24) |
| 59 | | ((v & 0x000000ff00000000ULL) >> 8) |
| 60 | | ((v & 0x00000000ff000000ULL) << 8) |
| 61 | | ((v & 0x0000000000ff0000ULL) << 24) |
| 62 | | ((v & 0x000000000000ff00ULL) << 40) |
| 63 | | ((v & 0x00000000000000ffULL) << 56)); |
| 64 | } |
| 65 | #endif /* !HAVE_DECL_BSWAP64 */ |
| 66 | |
| 67 | /* < C11? define away static assertions. */ |
| 68 | |
| 69 | #if !defined (__STDC_VERSION__) || __STDC_VERSION__ < 201112L |
| 70 | #define _Static_assert(cond, err) |
| 71 | #endif |
| 72 | |
| 73 | /* Swap the endianness of something. */ |
| 74 | |
| 75 | #define swap_thing(x) \ |
| 76 | do \ |
| 77 | { \ |
| 78 | _Static_assert (sizeof (x) == 1 || (sizeof (x) % 2 == 0 \ |
| 79 | && sizeof (x) <= 8), \ |
| 80 | "Invalid size, update endianness code"); \ |
| 81 | switch (sizeof (x)) { \ |
| 82 | case 2: x = bswap_16 (x); break; \ |
| 83 | case 4: x = bswap_32 (x); break; \ |
| 84 | case 8: x = bswap_64 (x); break; \ |
| 85 | case 1: /* Nothing needs doing */ \ |
| 86 | break; \ |
| 87 | } \ |
| 88 | } \ |
| 89 | while (0); |
| 90 | |
| 91 | |
| 92 | #endif /* !defined(_CTF_SWAP_H) */ |