[lttng-modules.git] / wrapper / compiler.h

#ifndef _LTTNG_WRAPPER_COMPILER_H
#define _LTTNG_WRAPPER_COMPILER_H

/*
 * wrapper/compiler.h
 *
 * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library 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; only
 * version 2.1 of the License.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <linux/compiler.h>

/*
 * Don't allow compiling with buggy compiler.
 */

#ifdef GCC_VERSION

/*
 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854
 */
# ifdef __ARMEL__
#  if GCC_VERSION >= 40800 && GCC_VERSION <= 40802
#   error Your gcc version produces clobbered frame accesses
#  endif
# endif
#endif

/*
 * READ/WRITE_ONCE were introduced in kernel 3.19 and ACCESS_ONCE
 * was removed in 4.15. Prefer READ/WRITE but fallback to ACCESS
 * when they are not available.
 */
#ifndef READ_ONCE
# define READ_ONCE(x)		ACCESS_ONCE(x)
#endif

#ifndef WRITE_ONCE
# define WRITE_ONCE(x, val)	({ ACCESS_ONCE(x) = val; })
#endif

#endif /* _LTTNG_WRAPPER_COMPILER_H */
Commit	Line	Data
	1	#ifndef _LTTNG_WRAPPER_COMPILER_H
	2	#define _LTTNG_WRAPPER_COMPILER_H
	3
	4	/*
	5	* wrapper/compiler.h
	6	*
	7	* Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	8	*
	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; only
	12	* version 2.1 of the License.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	22	*/
	23
	24	#include <linux/compiler.h>
	25
	26	/*
	27	* Don't allow compiling with buggy compiler.
	28	*/
	29
	30	#ifdef GCC_VERSION
	31
	32	/*
	33	* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854
	34	*/
	35	# ifdef __ARMEL__
	36	# if GCC_VERSION >= 40800 && GCC_VERSION <= 40802
	37	# error Your gcc version produces clobbered frame accesses
	38	# endif
	39	# endif
	40	#endif
	41
	42	/*
	43	* READ/WRITE_ONCE were introduced in kernel 3.19 and ACCESS_ONCE
	44	* was removed in 4.15. Prefer READ/WRITE but fallback to ACCESS
	45	* when they are not available.
	46	*/
	47	#ifndef READ_ONCE
	48	# define READ_ONCE(x) ACCESS_ONCE(x)
	49	#endif
	50
	51	#ifndef WRITE_ONCE
	52	# define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; })
	53	#endif
	54
	55	#endif /* _LTTNG_WRAPPER_COMPILER_H */