binutils-gdb/libctf/swap.h
Nick Alcock e755667f94 libctf, elfcpp, gold: do not assume that <byteswap.h> contains bswap_*
At least one C library (uclibc-ng) defines some of these only when
the compiler is GCC.  We might as well test for all three cases and
handle any of them being missing.

Very similar code exists in libctf and split between elfcpp and gold:
fix both.

(Also sync up elfcpp with a change made to libctf swap.h a few months
ago: since there is no out-of-line definition of the bswap replacements,
they should be declared static inline, not just inline, to prevent the
linker generating out-of-line references to them.)

	PR libctf/25120
libctf/
	* configure.ac: Check for bswap_16, bswap_32, and bswap_64 decls.
	* swap.h (bswap_16): Do not assume that presence of <byteswap.h>
	means this is declared.
	(bswap_32): Likewise.
	(bswap_64): Likewise.
	(bswap_identity_64): Remove, unused.
	* configure: Regenerated.
	* config.h.in: Likewise.
gold/
	* configure.ac: Check for bswap_16, bswap_32, and bswap_64 decls.
	* configure: Regenerated.
	* config.h.in: Likewise.
elfcpp/
	* elfcpp_swap.h (bswap_16): Do not assume that presence of
	<byteswap.h> means this is declared.  Make static inline, matching
	recent change to libctf, since there is no non-inline definition
	of these functions.
	(bswap_32): Likewise.
	(bswap_64): Likewise.
2020-06-26 15:56:39 +01:00

67 lines
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C

/* Interface to byteswapping functions.
Copyright (C) 2006-2020 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>
#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 */
#endif /* !defined(_CTF_SWAP_H) */