[lttng-ust.git] / include / usterr-signal-safe.h

#ifndef _USTERR_SIGNAL_SAFE_H
#define _USTERR_SIGNAL_SAFE_H

/*
 * Copyright (C) 2009  Pierre-Marc Fournier
 * Copyright (C) 2011  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; 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 <string.h>
#include <sys/types.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <share.h>
#include "lttng/ust-tid.h"

enum ust_loglevel {
	UST_LOGLEVEL_UNKNOWN = 0,
	UST_LOGLEVEL_NORMAL,
	UST_LOGLEVEL_DEBUG,
};

extern volatile enum ust_loglevel ust_loglevel;
void init_usterr(void);

#ifdef LTTNG_UST_DEBUG
static inline int ust_debug(void)
{
	return 1;
}
#else /* #ifdef LTTNG_UST_DEBUG */
static inline int ust_debug(void)
{
	return ust_loglevel == UST_LOGLEVEL_DEBUG;
}
#endif /* #else #ifdef LTTNG_UST_DEBUG */

#ifndef UST_COMPONENT
//#error UST_COMPONENT is undefined
#define UST_COMPONENT libust
#endif

/* To stringify the expansion of a define */
#define UST_XSTR(d) UST_STR(d)
#define UST_STR(s) #s

#define USTERR_MAX_LEN	512

/* We sometimes print in the tracing path, and tracing can occur in
 * signal handlers, so we must use a print method which is signal safe.
 */

extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...)
	__attribute__ ((format (printf, 3, 4)));

static inline void __attribute__ ((format (printf, 1, 2)))
	__check_ust_safe_fmt(const char *fmt, ...)
{
}

/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */
/* Add end of string in case of buffer overflow. */
#define sigsafe_print_err(fmt, args...)					\
do {									\
	if (ust_debug()) {						\
		char ____buf[USTERR_MAX_LEN];				\
		int ____saved_errno;					\
									\
		____saved_errno = errno;	/* signal-safety */	\
		ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
		____buf[sizeof(____buf) - 1] = 0;			\
		patient_write(STDERR_FILENO, ____buf, strlen(____buf));	\
		errno = ____saved_errno;	/* signal-safety */	\
		fflush(stderr);						\
	}								\
} while (0)

#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)

#define ERRMSG(fmt, args...)			\
	do {					\
		sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
		(long) getpid(),		\
		(long) lttng_gettid(),		\
		## args, __func__);		\
	} while(0)


#define DBG(fmt, args...)	ERRMSG(fmt, ## args)
#define DBG_raw(fmt, args...)	sigsafe_print_err(fmt, ## args)
#define WARN(fmt, args...)	ERRMSG("Warning: " fmt, ## args)
#define ERR(fmt, args...)	ERRMSG("Error: " fmt, ## args)
#define BUG(fmt, args...)	ERRMSG("BUG: " fmt, ## args)

#if !defined(__GLIBC__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
/*
 * Version using XSI strerror_r.
 */
#define PERROR(call, args...)						\
	do {								\
		if (ust_debug()) {					\
			char buf[200] = "Error in strerror_r()";	\
			strerror_r(errno, buf, sizeof(buf));		\
			ERRMSG("Error: " call ": %s", ## args, buf);	\
		}							\
	} while(0)
#else
/*
 * Version using GNU strerror_r, for linux with appropriate defines.
 */
#define PERROR(call, args...)						\
	do {								\
		if (ust_debug()) {					\
			char *buf;					\
			char tmp[200];					\
			buf = strerror_r(errno, tmp, sizeof(tmp));	\
			ERRMSG("Error: " call ": %s", ## args, buf);	\
		}							\
	} while(0)
#endif

#define BUG_ON(condition)					\
	do {							\
		if (caa_unlikely(condition))			\
			ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__);	\
	} while(0)
#define WARN_ON(condition)					\
	do {							\
		if (caa_unlikely(condition))			\
			WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	} while(0)
#define WARN_ON_ONCE(condition) WARN_ON(condition)

#endif /* _USTERR_SIGNAL_SAFE_H */
Commit	Line	Data
	1	#ifndef _USTERR_SIGNAL_SAFE_H
	2	#define _USTERR_SIGNAL_SAFE_H
	3
	4	/*
	5	* Copyright (C) 2009 Pierre-Marc Fournier
	6	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	7	*
	8	* This library is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; version 2.1 of
	11	* the License.
	12	*
	13	* This library is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with this library; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	#include <string.h>
	24	#include <sys/types.h>
	25	#include <errno.h>
	26	#include <stdarg.h>
	27	#include <stdio.h>
	28	#include <share.h>
	29	#include "lttng/ust-tid.h"
	30
	31	enum ust_loglevel {
	32	UST_LOGLEVEL_UNKNOWN = 0,
	33	UST_LOGLEVEL_NORMAL,
	34	UST_LOGLEVEL_DEBUG,
	35	};
	36
	37	extern volatile enum ust_loglevel ust_loglevel;
	38	void init_usterr(void);
	39
	40	#ifdef LTTNG_UST_DEBUG
	41	static inline int ust_debug(void)
	42	{
	43	return 1;
	44	}
	45	#else /* #ifdef LTTNG_UST_DEBUG */
	46	static inline int ust_debug(void)
	47	{
	48	return ust_loglevel == UST_LOGLEVEL_DEBUG;
	49	}
	50	#endif /* #else #ifdef LTTNG_UST_DEBUG */
	51
	52	#ifndef UST_COMPONENT
	53	//#error UST_COMPONENT is undefined
	54	#define UST_COMPONENT libust
	55	#endif
	56
	57	/* To stringify the expansion of a define */
	58	#define UST_XSTR(d) UST_STR(d)
	59	#define UST_STR(s) #s
	60
	61	#define USTERR_MAX_LEN 512
	62
	63	/* We sometimes print in the tracing path, and tracing can occur in
	64	* signal handlers, so we must use a print method which is signal safe.
	65	*/
	66
	67	extern int ust_safe_snprintf(char str, size_t n, const char fmt, ...)
	68	__attribute__ ((format (printf, 3, 4)));
	69
	70	static inline void __attribute__ ((format (printf, 1, 2)))
	71	__check_ust_safe_fmt(const char *fmt, ...)
	72	{
	73	}
	74
	75	/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */
	76	/* Add end of string in case of buffer overflow. */
	77	#define sigsafe_print_err(fmt, args...) \
	78	do { \
	79	if (ust_debug()) { \
	80	char ____buf[USTERR_MAX_LEN]; \
	81	int ____saved_errno; \
	82	\
	83	____saved_errno = errno; /* signal-safety */ \
	84	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
	85	____buf[sizeof(____buf) - 1] = 0; \
	86	patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
	87	errno = ____saved_errno; /* signal-safety */ \
	88	fflush(stderr); \
	89	} \
	90	} while (0)
	91
	92	#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
	93
	94	#define ERRMSG(fmt, args...) \
	95	do { \
	96	sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
	97	(long) getpid(), \
	98	(long) lttng_gettid(), \
	99	## args, __func__); \
	100	} while(0)
	101
	102
	103	#define DBG(fmt, args...) ERRMSG(fmt, ## args)
	104	#define DBG_raw(fmt, args...) sigsafe_print_err(fmt, ## args)
	105	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	106	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	107	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	108
	109	#if !defined(__GLIBC__) \|\| ((_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
	110	/*
	111	* Version using XSI strerror_r.
	112	*/
	113	#define PERROR(call, args...) \
	114	do { \
	115	if (ust_debug()) { \
	116	char buf[200] = "Error in strerror_r()"; \
	117	strerror_r(errno, buf, sizeof(buf)); \
	118	ERRMSG("Error: " call ": %s", ## args, buf); \
	119	} \
	120	} while(0)
	121	#else
	122	/*
	123	* Version using GNU strerror_r, for linux with appropriate defines.
	124	*/
	125	#define PERROR(call, args...) \
	126	do { \
	127	if (ust_debug()) { \
	128	char *buf; \
	129	char tmp[200]; \
	130	buf = strerror_r(errno, tmp, sizeof(tmp)); \
	131	ERRMSG("Error: " call ": %s", ## args, buf); \
	132	} \
	133	} while(0)
	134	#endif
	135
	136	#define BUG_ON(condition) \
	137	do { \
	138	if (caa_unlikely(condition)) \
	139	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	140	} while(0)
	141	#define WARN_ON(condition) \
	142	do { \
	143	if (caa_unlikely(condition)) \
	144	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	145	} while(0)
	146	#define WARN_ON_ONCE(condition) WARN_ON(condition)
	147
	148	#endif /* _USTERR_SIGNAL_SAFE_H */