diff options
| author | Warner Losh <imp@FreeBSD.org> | 2023-01-20 23:33:37 +0000 |
|---|---|---|
| committer | Warner Losh <imp@FreeBSD.org> | 2023-01-24 23:26:28 +0000 |
| commit | 1dd126163b9448c2dcfe27978fee50649548437c (patch) | |
| tree | f44652aea68c4fbeeab3943f90cb45481e0119e6 | |
| parent | 1004da283d45d2f343a3b2fcde48dc8c558a339a (diff) | |
byteswap.h: Add a glibc/linux compatible byteswap.h
For endian.h to work instead of sys/endian.h, some software needs
byteswap.h available. It must define {__,}byteswap_{16,32,64}.
Included sys/_endian.h to get an appropriate __byteswap16, etc
and defines the new macros in terms of them. Enhance _endian.h
to allow it to be included from here too.
Sponsored by: Netflix
Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D32051
(cherry picked from commit 1761b09bf42d2842e82c1ac614c23d31c4d4c0dc)
| -rw-r--r-- | include/Makefile | 3 | ||||
| -rw-r--r-- | include/byteswap.h | 41 | ||||
| -rw-r--r-- | sys/sys/_endian.h | 2 |
3 files changed, 44 insertions, 2 deletions
diff --git a/include/Makefile b/include/Makefile index b7aa723a562f..490b430d94c6 100644 --- a/include/Makefile +++ b/include/Makefile @@ -9,7 +9,8 @@ PACKAGE=runtime CLEANFILES= osreldate.h version SUBDIR= arpa protocols rpcsvc rpc xlocale SUBDIR_PARALLEL= -INCS= a.out.h ar.h assert.h bitstring.h complex.h cpio.h _ctype.h ctype.h \ +INCS= a.out.h ar.h assert.h bitstring.h byteswap.h \ + complex.h cpio.h _ctype.h ctype.h \ db.h \ dirent.h dlfcn.h elf.h elf-hints.h endian.h err.h fmtmsg.h fnmatch.h \ fstab.h fts.h ftw.h getopt.h glob.h grp.h \ diff --git a/include/byteswap.h b/include/byteswap.h new file mode 100644 index 000000000000..a7b816ee82b0 --- /dev/null +++ b/include/byteswap.h @@ -0,0 +1,41 @@ +/*- + * Copyright (c) 2021 M. Warner Losh <imp@FreeBSD.org> + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +/* + * A mostly Linux/glibc-compatible byteswap.h + */ + +#ifndef _BYTESWAP_H_ +#define _BYTESWAP_H_ + +/* + * sys/_endian.h brings in the shared interfaces between BSD's sys/endian.h, and + * glibc's endian.h. However, we need to include it here to get the + * __bswap{16,32,64} definitions that we use. sys/_endian.h has been consturcted to + * be compatible with including <endian.h>, <byteswap.h> or both in either order, + * as well as providing the BSD the bulk of sys/endian.h functionality. + */ +#include <sys/_endian.h> + +/* + * glibc's <byteswap.h> defines the bswap_* and __bswap_* macros below. Most + * software uses either just <sys/endian.h>, or both <endian.h> and + * <byteswap.h>. However, one can't define bswap16, etc in <endian.h> because + * several software packages will define them only when they detect <endian.h> + * is included (but not when sys/endian.h is included). Defining bswap16, etc + * here causes compilation errors for those packages. <endian.h> and + * <byteswap.h> need to be paired together, with the below defines here, for + * the highest level of glibc compatibility. + */ +#define __bswap_16(x) __bswap16(x) +#define __bswap_32(x) __bswap32(x) +#define __bswap_64(x) __bswap64(x) + +#define bswap_16(x) __bswap16(x) +#define bswap_32(x) __bswap32(x) +#define bswap_64(x) __bswap64(x) + +#endif /* _BYTESWAP_H_ */ diff --git a/sys/sys/_endian.h b/sys/sys/_endian.h index 72e1a40a8deb..ff909f532663 100644 --- a/sys/sys/_endian.h +++ b/sys/sys/_endian.h @@ -32,7 +32,7 @@ #ifndef _SYS__ENDIAN_H_ #define _SYS__ENDIAN_H_ -#if !defined(_MACHINE_ENDIAN_H_) && !defined(_ENDIAN_H_) +#if !defined(_MACHINE_ENDIAN_H_) && !defined(_BYTESWAP_H_) && !defined(_ENDIAN_H_) #error "sys/_endian.h should not be included directly" #endif |