RepoMirrors
/
musl
mirror of git://git.musl-libc.org/musl
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
musl/include/endian.h

81 lines
1.9 KiB
C
Raw Normal View History

initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#ifndef _ENDIAN_H
#define _ENDIAN_H
default features: make musl usable without feature test macros the old behavior of exposing nothing except plain ISO C can be obtained by defining __STRICT_ANSI__ or using a compiler option (such as -std=c99) that predefines it. the new default featureset is POSIX with XSI plus _BSD_SOURCE. any explicit feature test macros will inhibit the default. installation docs have also been updated to reflect this change.
2012-09-08 03:13:55 +00:00
#include <features.h>
avoid "inline" in public headers for strict c89 compatibility while musl itself requires a c99 compiler, some applications insist on being compiled with c89 compilers, and use of "inline" in the headers was breaking them. much of this had been avoided already by just skipping the inline keyword in pre-c99 compilers or modes, but this new unified solution is cleaner and may/should result in better code generation in the default gcc configuration.
2012-09-02 16:46:06 +00:00
make endian.h expose unprefixed macros, functions in standard profile the resolution of Austin Group issue #162 adds endian.h as a standard header for future versions of the standard, making it no longer acceptable for some of the functionality to be hidden behind _BSD_SOURCE or _GNU_SOURCE. the definitions of the [lb]etoh{16,32,64} function-like macros are kept conditional since they are alternate names which the standard did not adopt.
2019-10-17 20:26:22 +00:00
#define __NEED_uint16_t
#define __NEED_uint32_t
#define __NEED_uint64_t
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
move __BYTE_ORDER definition to alltypes.h this change is motivated by the intersection of several factors. presently, despite being a nonstandard header, endian.h is exposing the unprefixed byte order macros and functions only if _BSD_SOURCE or _GNU_SOURCE is defined. this is to accommodate use of endian.h from other headers, including bits headers, which need to define structure layout in terms of endianness. with time64 switch-over, even more headers will need to do this. at the same time, the resolution of Austin Group issue 162 makes endian.h a standard header for POSIX-future, requiring that it expose the unprefixed macros and the functions even in standards-conforming profiles. changes to meet this new requirement would break existing internal usage of endian.h by causing it to violate namespace where it's used. instead, have the arch's alltypes.h define __BYTE_ORDER, either as a fixed constant or depending on the right arch-specific predefined macros for determining endianness. explicit literals 1234 and 4321 are used instead of __LITTLE_ENDIAN and __BIG_ENDIAN so that there's no danger of getting the wrong result if a macro is undefined and implicitly evaluates to 0 at the preprocessor level. the powerpc (32-bit) bits/endian.h being removed had logic for varying endianness, but our powerpc arch has never supported that and has always been big-endian-only. this logic is not carried over to the new __BYTE_ORDER definition in alltypes.h.
2019-10-17 19:40:16 +00:00
#include <bits/alltypes.h>
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
make endian.h expose unprefixed macros, functions in standard profile the resolution of Austin Group issue #162 adds endian.h as a standard header for future versions of the standard, making it no longer acceptable for some of the functionality to be hidden behind _BSD_SOURCE or _GNU_SOURCE. the definitions of the [lb]etoh{16,32,64} function-like macros are kept conditional since they are alternate names which the standard did not adopt.
2019-10-17 20:26:22 +00:00
#define __PDP_ENDIAN 3412
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#define BIG_ENDIAN __BIG_ENDIAN
#define LITTLE_ENDIAN __LITTLE_ENDIAN
#define PDP_ENDIAN __PDP_ENDIAN
#define BYTE_ORDER __BYTE_ORDER
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
avoid "inline" in public headers for strict c89 compatibility while musl itself requires a c99 compiler, some applications insist on being compiled with c89 compilers, and use of "inline" in the headers was breaking them. much of this had been avoided already by just skipping the inline keyword in pre-c99 compilers or modes, but this new unified solution is cleaner and may/should result in better code generation in the default gcc configuration.
2012-09-02 16:46:06 +00:00
static __inline uint16_t __bswap16(uint16_t __x)
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
{
return __x<<8 | __x>>8;
}
avoid "inline" in public headers for strict c89 compatibility while musl itself requires a c99 compiler, some applications insist on being compiled with c89 compilers, and use of "inline" in the headers was breaking them. much of this had been avoided already by just skipping the inline keyword in pre-c99 compilers or modes, but this new unified solution is cleaner and may/should result in better code generation in the default gcc configuration.
2012-09-02 16:46:06 +00:00
static __inline uint32_t __bswap32(uint32_t __x)
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
{
return __x>>24 | __x>>8&0xff00 | __x<<8&0xff0000 | __x<<24;
}
avoid "inline" in public headers for strict c89 compatibility while musl itself requires a c99 compiler, some applications insist on being compiled with c89 compilers, and use of "inline" in the headers was breaking them. much of this had been avoided already by just skipping the inline keyword in pre-c99 compilers or modes, but this new unified solution is cleaner and may/should result in better code generation in the default gcc configuration.
2012-09-02 16:46:06 +00:00
static __inline uint64_t __bswap64(uint64_t __x)
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
{
fix breakage in endian.h
2012-04-22 15:19:17 +00:00
return __bswap32(__x)+0ULL<<32 | __bswap32(__x>>32);
add some ugly byte swapping cruft in endian.h
2012-04-22 15:08:01 +00:00
}
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define htobe16(x) __bswap16(x)
#define be16toh(x) __bswap16(x)
#define htobe32(x) __bswap32(x)
#define be32toh(x) __bswap32(x)
#define htobe64(x) __bswap64(x)
#define be64toh(x) __bswap64(x)
#define htole16(x) (uint16_t)(x)
#define le16toh(x) (uint16_t)(x)
#define htole32(x) (uint32_t)(x)
#define le32toh(x) (uint32_t)(x)
#define htole64(x) (uint64_t)(x)
#define le64toh(x) (uint64_t)(x)
#else
#define htobe16(x) (uint16_t)(x)
#define be16toh(x) (uint16_t)(x)
#define htobe32(x) (uint32_t)(x)
#define be32toh(x) (uint32_t)(x)
#define htobe64(x) (uint64_t)(x)
#define be64toh(x) (uint64_t)(x)
#define htole16(x) __bswap16(x)
#define le16toh(x) __bswap16(x)
#define htole32(x) __bswap32(x)
#define le32toh(x) __bswap32(x)
#define htole64(x) __bswap64(x)
#define le64toh(x) __bswap64(x)
#endif
make endian.h expose unprefixed macros, functions in standard profile the resolution of Austin Group issue #162 adds endian.h as a standard header for future versions of the standard, making it no longer acceptable for some of the functionality to be hidden behind _BSD_SOURCE or _GNU_SOURCE. the definitions of the [lb]etoh{16,32,64} function-like macros are kept conditional since they are alternate names which the standard did not adopt.
2019-10-17 20:26:22 +00:00
#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define betoh16(x) __bswap16(x)
#define betoh32(x) __bswap32(x)
#define betoh64(x) __bswap64(x)
#define letoh16(x) (uint16_t)(x)
#define letoh32(x) (uint32_t)(x)
#define letoh64(x) (uint64_t)(x)
#else
#define betoh16(x) (uint16_t)(x)
#define betoh32(x) (uint32_t)(x)
#define betoh64(x) (uint64_t)(x)
#define letoh16(x) __bswap16(x)
#define letoh32(x) __bswap32(x)
#define letoh64(x) __bswap64(x)
#endif
initial check-in, version 0.5.0
2011-02-12 05:22:29 +00:00
#endif
#endif