[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 <sys/syscall.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>

#include <ust/core.h>

#include "share.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 XSTR(d) STR(d)
#define STR(s) #s

/* 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, ...)
{
}

#define sigsafe_print_err(fmt, args...)					\
{									\
	/* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
	char ____buf[250];						\
	int ____saved_errno;						\
									\
	/* Save the errno. */						\
	____saved_errno = errno;					\
									\
	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args);	\
									\
	/* Add end of string in case of buffer overflow. */		\
	____buf[sizeof(____buf) - 1] = 0;				\
									\
	patient_write(STDERR_FILENO, ____buf, strlen(____buf));		\
	/*								\
	 * Can't print errors because we are in the error printing code \
	 * path.							\
	 */								\
									\
	/* Restore errno, in order to be async-signal safe. */		\
	errno = ____saved_errno;					\
}

#define UST_STR_COMPONENT XSTR(UST_COMPONENT)

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

#ifdef 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 (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
#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
#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 (unlikely(condition))			\
			ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__);	\
	} while(0)
#define WARN_ON(condition)					\
	do {							\
		if (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>
	24	#include <sys/types.h>
	25	#include <sys/syscall.h>
	26	#include <errno.h>
	27	#include <stdarg.h>
	28	#include <stdio.h>
	29
	30	#include <ust/core.h>
	31
	32	#include "share.h"
	33
5e96a467 MD	34	enum ust_loglevel {
	35	UST_LOGLEVEL_UNKNOWN = 0,
	36	UST_LOGLEVEL_NORMAL,
	37	UST_LOGLEVEL_DEBUG,
	38	};
	39
	40	extern volatile enum ust_loglevel ust_loglevel;
	41	void init_usterr(void);
	42
	43	static inline int ust_debug(void)
	44	{
	45	return ust_loglevel == UST_LOGLEVEL_DEBUG;
	46	}
	47
30ffe279 NC	48	#ifndef UST_COMPONENT
	49	//#error UST_COMPONENT is undefined
	50	#define UST_COMPONENT libust
	51	#endif
	52
	53	/* To stringify the expansion of a define */
	54	#define XSTR(d) STR(d)
	55	#define STR(s) #s
	56
	57	/* We sometimes print in the tracing path, and tracing can occur in
	58	* signal handlers, so we must use a print method which is signal safe.
	59	*/
	60
	61	extern int ust_safe_snprintf(char str, size_t n, const char fmt, ...)
	62	__attribute__ ((format (printf, 3, 4)));
	63
	64	static inline void __attribute__ ((format (printf, 1, 2)))
	65	__check_ust_safe_fmt(const char *fmt, ...)
	66	{
	67	}
	68
5e96a467 MD	69	#define sigsafe_print_err(fmt, args...) \
5e96a467 MD	70	{ \
30ffe279	71	/* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
5e96a467 MD	72	char ____buf[250]; \
	73	int ____saved_errno; \
	74	\
	75	/* Save the errno. */ \
	76	____saved_errno = errno; \
	77	\
	78	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
	79	\
	80	/* Add end of string in case of buffer overflow. */ \
	81	____buf[sizeof(____buf) - 1] = 0; \
	82	\
	83	patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
	84	/* \
	85	* Can't print errors because we are in the error printing code \
	86	* path. \
	87	*/ \
	88	\
	89	/* Restore errno, in order to be async-signal safe. */ \
	90	errno = ____saved_errno; \
30ffe279 NC	91	}
	92
	93	#define UST_STR_COMPONENT XSTR(UST_COMPONENT)
	94
5e96a467 MD	95	#define ERRMSG(fmt, args...) \
	96	do { \
	97	sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" XSTR(__LINE__) ")\n", \
	98	(long) getpid(), \
	99	(long) syscall(SYS_gettid), \
	100	## args, __func__); \
	101	fflush(stderr); \
	102	} while(0)
30ffe279 NC	103
30ffe279 NC	104	#ifdef UST_DEBUG
5e96a467 MD	105	# define DBG(fmt, args...) ERRMSG(fmt, ## args)
	106	# define DBG_raw(fmt, args...) \
	107	do { \
	108	sigsafe_print_err(fmt, ## args); \
	109	fflush(stderr); \
	110	} while(0)
30ffe279	111	#else
5e96a467 MD	112	# define DBG(fmt, args...) \
	113	do { \
	114	if (ust_debug()) \
	115	ERRMSG(fmt, ## args); \
	116	} while (0)
	117	# define DBG_raw(fmt, args...) \
	118	do { \
	119	if (ust_debug()) { \
	120	sigsafe_print_err(fmt, ## args); \
	121	fflush(stderr); \
	122	} \
	123	} while(0)
30ffe279 NC	124	#endif
	125	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	126	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	127	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	128
	129	#if (_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
	130	#define PERROR(call, args...)\
	131	do { \
	132	char buf[200] = "Error in strerror_r()"; \
	133	strerror_r(errno, buf, sizeof(buf)); \
	134	ERRMSG("Error: " call ": %s", ## args, buf); \
	135	} while(0);
	136	#else
	137	#define PERROR(call, args...)\
	138	do { \
	139	char *buf; \
	140	char tmp[200]; \
	141	buf = strerror_r(errno, tmp, sizeof(tmp)); \
	142	ERRMSG("Error: " call ": %s", ## args, buf); \
	143	} while(0);
	144	#endif
	145
5e96a467 MD	146	#define BUG_ON(condition) \
	147	do { \
	148	if (unlikely(condition)) \
	149	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	150	} while(0)
	151	#define WARN_ON(condition) \
	152	do { \
	153	if (unlikely(condition)) \
	154	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	155	} while(0)
30ffe279 NC	156	#define WARN_ON_ONCE(condition) WARN_ON(condition)
30ffe279 NC	157
5e96a467	158
30ffe279	159	#endif /* _USTERR_SIGNAL_SAFE_H */