blob: 4d0b48c9e759e9c002a3b5b70a16ccb4519365d0 [file] [log] [blame]
/* Interface to byteswapping functions.
Copyright (C) 2006-2021 Free Software Foundation, Inc.
This file is part of libctf.
libctf is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not see
<http://www.gnu.org/licenses/>. */
#ifndef _CTF_SWAP_H
#define _CTF_SWAP_H
#include "config.h"
#include <stdint.h>
#include <assert.h>
#ifdef HAVE_BYTESWAP_H
#include <byteswap.h>
#endif /* defined(HAVE_BYTESWAP_H) */
/* Provide our own versions of the byteswap functions. */
#if !HAVE_DECL_BSWAP_16
static inline uint16_t
bswap_16 (uint16_t v)
{
return ((v >> 8) & 0xff) | ((v & 0xff) << 8);
}
#endif /* !HAVE_DECL_BSWAP16 */
#if !HAVE_DECL_BSWAP_32
static inline uint32_t
bswap_32 (uint32_t v)
{
return ( ((v & 0xff000000) >> 24)
| ((v & 0x00ff0000) >> 8)
| ((v & 0x0000ff00) << 8)
| ((v & 0x000000ff) << 24));
}
#endif /* !HAVE_DECL_BSWAP32 */
#if !HAVE_DECL_BSWAP_64
static inline uint64_t
bswap_64 (uint64_t v)
{
return ( ((v & 0xff00000000000000ULL) >> 56)
| ((v & 0x00ff000000000000ULL) >> 40)
| ((v & 0x0000ff0000000000ULL) >> 24)
| ((v & 0x000000ff00000000ULL) >> 8)
| ((v & 0x00000000ff000000ULL) << 8)
| ((v & 0x0000000000ff0000ULL) << 24)
| ((v & 0x000000000000ff00ULL) << 40)
| ((v & 0x00000000000000ffULL) << 56));
}
#endif /* !HAVE_DECL_BSWAP64 */
/* < C11? define away static assertions. */
#if !defined (__STDC_VERSION__) || __STDC_VERSION__ < 201112L
#define _Static_assert(cond, err)
#endif
/* Swap the endianness of something. */
#define swap_thing(x) \
do \
{ \
_Static_assert (sizeof (x) == 1 || (sizeof (x) % 2 == 0 \
&& sizeof (x) <= 8), \
"Invalid size, update endianness code"); \
switch (sizeof (x)) { \
case 2: x = bswap_16 (x); break; \
case 4: x = bswap_32 (x); break; \
case 8: x = bswap_64 (x); break; \
case 1: /* Nothing needs doing */ \
break; \
} \
} \
while (0);
#endif /* !defined(_CTF_SWAP_H) */