emacs/lib/endian.in.h

253 lines
4.4 KiB
C

/* endian.h - Byte order macros
Copyright 2024 Free Software Foundation, Inc.
This file is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
This file 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Collin Funk. */
#ifndef _@GUARD_PREFIX@_ENDIAN_H
#if __GNUC__ >= 3
@PRAGMA_SYSTEM_HEADER@
#endif
@PRAGMA_COLUMNS@
#if @HAVE_ENDIAN_H@
/* The include_next requires a split double-inclusion guard. */
# @INCLUDE_NEXT@ @NEXT_ENDIAN_H@
#endif
/* glibc defines all macros and functions but is missing types from
stdint.h. */
#if @ENDIAN_H_JUST_MISSING_STDINT@
# include <stdint.h>
#else
/* Others platforms. */
#ifndef _@GUARD_PREFIX@_ENDIAN_H
#define _@GUARD_PREFIX@_ENDIAN_H 1
/* This file uses _GL_INLINE, WORDS_BIGENDIAN. */
#if !_GL_CONFIG_H_INCLUDED
#error "Please include config.h first."
#endif
/* Define uint16_t and uint32_t.
Define uint64_t if it is available. */
#include <stdint.h>
/* Byteswap functions. */
#include <byteswap.h>
_GL_INLINE_HEADER_BEGIN
#ifndef _GL_ENDIAN_INLINE
# define _GL_ENDIAN_INLINE _GL_INLINE
#endif
#define LITTLE_ENDIAN 1234
#define BIG_ENDIAN 4321
#define PDP_ENDIAN 3412
#ifdef WORDS_BIGENDIAN
# define BYTE_ORDER BIG_ENDIAN
#else
# define BYTE_ORDER LITTLE_ENDIAN
#endif
#if @HAVE_ENDIAN_H@
/* Make sure we don't have any system definitions. */
# undef be16toh
# undef be32toh
# undef be64toh
# undef htobe16
# undef htobe32
# undef htobe64
# undef le16toh
# undef le32toh
# undef le64toh
# undef htole16
# undef htole32
# undef htole64
/* Define our own. */
# define be16toh rpl_endian_be16toh
# define be32toh rpl_endian_be32toh
# define be64toh rpl_endian_be64toh
# define htobe16 rpl_endian_htobe16
# define htobe32 rpl_endian_htobe32
# define htobe64 rpl_endian_htobe64
# define le16toh rpl_endian_le16toh
# define le32toh rpl_endian_le32toh
# define le64toh rpl_endian_le64toh
# define htole16 rpl_endian_htole16
# define htole32 rpl_endian_htole32
# define htole64 rpl_endian_htole64
#endif
#ifdef __cplusplus
extern "C" {
#endif
/* Big endian to host. */
_GL_ENDIAN_INLINE uint16_t
be16toh (uint16_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return x;
#else
return bswap_16 (x);
#endif
}
_GL_ENDIAN_INLINE uint32_t
be32toh (uint32_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return x;
#else
return bswap_32 (x);
#endif
}
#ifdef UINT64_MAX
_GL_ENDIAN_INLINE uint64_t
be64toh (uint64_t x)
{
# if BYTE_ORDER == BIG_ENDIAN
return x;
# else
return bswap_64 (x);
# endif
}
#endif
/* Host to big endian. */
_GL_ENDIAN_INLINE uint16_t
htobe16 (uint16_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return x;
#else
return bswap_16 (x);
#endif
}
_GL_ENDIAN_INLINE uint32_t
htobe32 (uint32_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return x;
#else
return bswap_32 (x);
#endif
}
#ifdef UINT64_MAX
_GL_ENDIAN_INLINE uint64_t
htobe64 (uint64_t x)
{
# if BYTE_ORDER == BIG_ENDIAN
return x;
# else
return bswap_64 (x);
# endif
}
#endif
/* Little endian to host. */
_GL_ENDIAN_INLINE uint16_t
le16toh (uint16_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return bswap_16 (x);
#else
return x;
#endif
}
_GL_ENDIAN_INLINE uint32_t
le32toh (uint32_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return bswap_32 (x);
#else
return x;
#endif
}
#ifdef UINT64_MAX
_GL_ENDIAN_INLINE uint64_t
le64toh (uint64_t x)
{
# if BYTE_ORDER == BIG_ENDIAN
return bswap_64 (x);
# else
return x;
# endif
}
#endif
/* Host to little endian. */
_GL_ENDIAN_INLINE uint16_t
htole16 (uint16_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return bswap_16 (x);
#else
return x;
#endif
}
_GL_ENDIAN_INLINE uint32_t
htole32 (uint32_t x)
{
#if BYTE_ORDER == BIG_ENDIAN
return bswap_32 (x);
#else
return x;
#endif
}
#ifdef UINT64_MAX
_GL_ENDIAN_INLINE uint64_t
htole64 (uint64_t x)
{
# if BYTE_ORDER == BIG_ENDIAN
return bswap_64 (x);
# else
return x;
# endif
}
#endif
#ifdef __cplusplus
}
#endif
_GL_INLINE_HEADER_END
#endif /* @ENDIAN_H_JUST_MISSING_STDINT@ */
#endif /* _@GUARD_PREFIX@_ENDIAN_H */
#endif /* _@GUARD_PREFIX@_ENDIAN_H */