[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);

static inline int ust_debug(void)
{
	return ust_loglevel == UST_LOGLEVEL_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 {									\
	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 */		\
} 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) gettid(),		\
		## args, __func__);		\
		fflush(stderr);			\
	} while(0)

#ifdef LTTNG_UST_DEBUG
# define DBG(fmt, args...)			ERRMSG(fmt, ## args)
# define DBG_raw(fmt, args...)					\
	do {							\
		sigsafe_print_err(fmt, ## args);		\
		fflush(stderr);					\
	} while(0)
#else
# define DBG(fmt, args...)					\
	do {							\
		if (ust_debug())				\
			ERRMSG(fmt, ## args);			\
	} while (0)
# define DBG_raw(fmt, args...)					\
	do {							\
		if (ust_debug()) {				\
			sigsafe_print_err(fmt, ## args);	\
			fflush(stderr);				\
		}						\
	} while(0)
#endif
#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(__linux__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
/*
 * Version using XSI strerror_r.
 */
#define PERROR(call, args...)\
	do { \
		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 { \
		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
5e96a467 MD	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>
30ffe279 NC	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
5e96a467 MD	10	* License as published by the Free Software Foundation; version 2.1 of
5e96a467 MD	11	* the License.
30ffe279 NC	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
30ffe279 NC	23	#include <string.h>
30ffe279 NC	24	#include <sys/types.h>
30ffe279 NC	25	#include <errno.h>
	26	#include <stdarg.h>
	27	#include <stdio.h>
2f864739	28	#include <share.h>
d9ecffa9	29	#include "lttng/ust-tid.h"
30ffe279	30
5e96a467 MD	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	static inline int ust_debug(void)
	41	{
	42	return ust_loglevel == UST_LOGLEVEL_DEBUG;
	43	}
	44
30ffe279 NC	45	#ifndef UST_COMPONENT
	46	//#error UST_COMPONENT is undefined
	47	#define UST_COMPONENT libust
	48	#endif
	49
	50	/* To stringify the expansion of a define */
1dbfff0c MD	51	#define UST_XSTR(d) UST_STR(d)
1dbfff0c MD	52	#define UST_STR(s) #s
30ffe279	53
37ed587a MD	54	#define USTERR_MAX_LEN 512
37ed587a MD	55
30ffe279 NC	56	/* We sometimes print in the tracing path, and tracing can occur in
	57	* signal handlers, so we must use a print method which is signal safe.
	58	*/
	59
	60	extern int ust_safe_snprintf(char str, size_t n, const char fmt, ...)
	61	__attribute__ ((format (printf, 3, 4)));
	62
	63	static inline void __attribute__ ((format (printf, 1, 2)))
	64	__check_ust_safe_fmt(const char *fmt, ...)
	65	{
	66	}
	67
648bb724 MD	68	/* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */
648bb724 MD	69	/* Add end of string in case of buffer overflow. */
5e96a467	70	#define sigsafe_print_err(fmt, args...) \
648bb724	71	do { \
37ed587a	72	char ____buf[USTERR_MAX_LEN]; \
5e96a467	73	int ____saved_errno; \
648bb724	74	____saved_errno = errno; /* signal-safety */ \
5e96a467	75	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
5e96a467	76	____buf[sizeof(____buf) - 1] = 0; \
5e96a467	77	patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
648bb724 MD	78	errno = ____saved_errno; /* signal-safety */ \
648bb724 MD	79	} while (0)
30ffe279	80
1dbfff0c	81	#define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
30ffe279	82
5e96a467 MD	83	#define ERRMSG(fmt, args...) \
5e96a467 MD	84	do { \
1dbfff0c	85	sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n", \
5e96a467	86	(long) getpid(), \
d9ecffa9	87	(long) gettid(), \
5e96a467 MD	88	## args, __func__); \
	89	fflush(stderr); \
	90	} while(0)
30ffe279	91
69400ac4	92	#ifdef LTTNG_UST_DEBUG
5e96a467 MD	93	# define DBG(fmt, args...) ERRMSG(fmt, ## args)
	94	# define DBG_raw(fmt, args...) \
	95	do { \
	96	sigsafe_print_err(fmt, ## args); \
	97	fflush(stderr); \
	98	} while(0)
30ffe279	99	#else
5e96a467 MD	100	# define DBG(fmt, args...) \
	101	do { \
	102	if (ust_debug()) \
	103	ERRMSG(fmt, ## args); \
	104	} while (0)
	105	# define DBG_raw(fmt, args...) \
	106	do { \
	107	if (ust_debug()) { \
	108	sigsafe_print_err(fmt, ## args); \
	109	fflush(stderr); \
	110	} \
	111	} while(0)
30ffe279 NC	112	#endif
	113	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	114	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	115	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	116
fb8c8e5f MD	117	#if !defined(__linux__) \|\| ((_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
	118	/*
	119	* Version using XSI strerror_r.
	120	*/
30ffe279 NC	121	#define PERROR(call, args...)\
	122	do { \
	123	char buf[200] = "Error in strerror_r()"; \
	124	strerror_r(errno, buf, sizeof(buf)); \
	125	ERRMSG("Error: " call ": %s", ## args, buf); \
	126	} while(0);
	127	#else
fb8c8e5f MD	128	/*
	129	* Version using GNU strerror_r, for linux with appropriate defines.
	130	*/
30ffe279 NC	131	#define PERROR(call, args...)\
	132	do { \
	133	char *buf; \
	134	char tmp[200]; \
	135	buf = strerror_r(errno, tmp, sizeof(tmp)); \
	136	ERRMSG("Error: " call ": %s", ## args, buf); \
	137	} while(0);
	138	#endif
	139
5e96a467 MD	140	#define BUG_ON(condition) \
5e96a467 MD	141	do { \
b5a3dfa5	142	if (caa_unlikely(condition)) \
5e96a467 MD	143	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	144	} while(0)
	145	#define WARN_ON(condition) \
	146	do { \
b5a3dfa5	147	if (caa_unlikely(condition)) \
5e96a467 MD	148	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
5e96a467 MD	149	} while(0)
30ffe279 NC	150	#define WARN_ON_ONCE(condition) WARN_ON(condition)
	151
	152	#endif /* _USTERR_SIGNAL_SAFE_H */