[lttng-ust.git] / src / common / logging.h

/*
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 * Copyright (C) 2009 Pierre-Marc Fournier
 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#ifndef _UST_COMMON_LOGGING_H
#define _UST_COMMON_LOGGING_H

#include <string.h>
#include <sys/types.h>
#include <errno.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>

#include <lttng/ust-utils.h>
#include <urcu/compiler.h>
#include <urcu/system.h>

#include "common/patient.h"
#include "common/compat/tid.h"
#include "common/safe-snprintf.h"

enum lttng_ust_log_level {
	LTTNG_UST_LOG_LEVEL_UNKNOWN = 0,
	LTTNG_UST_LOG_LEVEL_SILENT,
	LTTNG_UST_LOG_LEVEL_DEBUG,
};

extern int lttng_ust_log_level			/* enum lttng_ust_log_level */
	__attribute__((visibility("hidden")));

/*
 * Initialize the global log level from the "LTTNG_UST_DEBUG" environment
 * variable.
 *
 * This could end up being called concurrently by multiple threads but doesn't
 * require a mutex since the input is invariant across threads and the result
 * will be the same.
 *
 * Return the current log level to save the caller a second read of the global
 * log level.
 */
int lttng_ust_logging_init(void)
	__attribute__((visibility("hidden")));

#ifdef LTTNG_UST_DEBUG
static inline
bool lttng_ust_logging_debug_enabled(void)
{
	return true;
}
#else /* #ifdef LTTNG_UST_DEBUG */
static inline
bool lttng_ust_logging_debug_enabled(void)
{
	int current_log_level;

	current_log_level = CMM_LOAD_SHARED(lttng_ust_log_level);

	/* If the global log level is unknown, lazy-initialize it. */
	if (caa_unlikely(current_log_level == LTTNG_UST_LOG_LEVEL_UNKNOWN))
		current_log_level = lttng_ust_logging_init();

	return current_log_level == LTTNG_UST_LOG_LEVEL_DEBUG;
}
#endif /* #ifdef LTTNG_UST_DEBUG */

/*
 * The default component for error messages.
 */
#ifndef UST_COMPONENT
#define UST_COMPONENT libust
#endif

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

#define LTTNG_UST_STR_COMPONENT lttng_ust_stringify(UST_COMPONENT)

#define ERRMSG(fmt, args...)			\
	do {					\
		sigsafe_print_err(LTTNG_UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" lttng_ust_stringify(__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 (lttng_ust_logging_debug_enabled()) {		\
			char perror_buf[200] = "Error in strerror_r()";	\
			strerror_r(errno, perror_buf,			\
					sizeof(perror_buf));		\
			ERRMSG("Error: " call ": %s", ## args, 		\
					perror_buf);			\
		}							\
	} while(0)
#else
/*
 * Version using GNU strerror_r, for linux with appropriate defines.
 */
#define PERROR(call, args...)						\
	do {								\
		if (lttng_ust_logging_debug_enabled()) {		\
			char *perror_buf;				\
			char perror_tmp[200];				\
			perror_buf = strerror_r(errno, perror_tmp,	\
					sizeof(perror_tmp));		\
			ERRMSG("Error: " call ": %s", ## args,		\
					perror_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 /* _UST_COMMON_LOGGING_H */
Commit	Line	Data
	1	/*
	2	* SPDX-License-Identifier: LGPL-2.1-only
	3	*
	4	* Copyright (C) 2009 Pierre-Marc Fournier
	5	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	6	*/
	7
	8	#ifndef _UST_COMMON_LOGGING_H
	9	#define _UST_COMMON_LOGGING_H
	10
	11	#include <string.h>
	12	#include <sys/types.h>
	13	#include <errno.h>
	14	#include <stdarg.h>
	15	#include <stdbool.h>
	16	#include <stdio.h>
	17
	18	#include <lttng/ust-utils.h>
	19	#include <urcu/compiler.h>
	20	#include <urcu/system.h>
	21
	22	#include "common/patient.h"
	23	#include "common/compat/tid.h"
	24	#include "common/safe-snprintf.h"
	25
	26	enum lttng_ust_log_level {
	27	LTTNG_UST_LOG_LEVEL_UNKNOWN = 0,
	28	LTTNG_UST_LOG_LEVEL_SILENT,
	29	LTTNG_UST_LOG_LEVEL_DEBUG,
	30	};
	31
	32	extern int lttng_ust_log_level /* enum lttng_ust_log_level */
	33	__attribute__((visibility("hidden")));
	34
	35	/*
	36	* Initialize the global log level from the "LTTNG_UST_DEBUG" environment
	37	* variable.
	38	*
	39	* This could end up being called concurrently by multiple threads but doesn't
	40	* require a mutex since the input is invariant across threads and the result
	41	* will be the same.
	42	*
	43	* Return the current log level to save the caller a second read of the global
	44	* log level.
	45	*/
	46	int lttng_ust_logging_init(void)
	47	__attribute__((visibility("hidden")));
	48
	49	#ifdef LTTNG_UST_DEBUG
	50	static inline
	51	bool lttng_ust_logging_debug_enabled(void)
	52	{
	53	return true;
	54	}
	55	#else /* #ifdef LTTNG_UST_DEBUG */
	56	static inline
	57	bool lttng_ust_logging_debug_enabled(void)
	58	{
	59	int current_log_level;
	60
	61	current_log_level = CMM_LOAD_SHARED(lttng_ust_log_level);
	62
	63	/* If the global log level is unknown, lazy-initialize it. */
	64	if (caa_unlikely(current_log_level == LTTNG_UST_LOG_LEVEL_UNKNOWN))
	65	current_log_level = lttng_ust_logging_init();
	66
	67	return current_log_level == LTTNG_UST_LOG_LEVEL_DEBUG;
	68	}
	69	#endif /* #ifdef LTTNG_UST_DEBUG */
	70
	71	/*
	72	* The default component for error messages.
	73	*/
	74	#ifndef UST_COMPONENT
	75	#define UST_COMPONENT libust
	76	#endif
	77
	78	#define LTTNG_UST_LOG_MAX_LEN 512
	79
	80	/*
	81	* We sometimes print in the tracing path, and tracing can occur in
	82	* signal handlers, so we must use a print method which is signal safe.
	83	*/
	84	/* Can't use dynamic allocation. Limit ourselves to LTTNG_UST_LOG_MAX_LEN chars. */
	85	/* Add end of string in case of buffer overflow. */
	86	#define sigsafe_print_err(fmt, args...) \
	87	do { \
	88	if (lttng_ust_logging_debug_enabled()) { \
	89	char ____buf[LTTNG_UST_LOG_MAX_LEN]; \
	90	int ____saved_errno; \
	91	\
	92	____saved_errno = errno; /* signal-safety */ \
	93	ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
	94	____buf[sizeof(____buf) - 1] = 0; \
	95	ust_patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
	96	errno = ____saved_errno; /* signal-safety */ \
	97	fflush(stderr); \
	98	} \
	99	} while (0)
	100
	101	#define LTTNG_UST_STR_COMPONENT lttng_ust_stringify(UST_COMPONENT)
	102
	103	#define ERRMSG(fmt, args...) \
	104	do { \
	105	sigsafe_print_err(LTTNG_UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" lttng_ust_stringify(__LINE__) ")\n", \
	106	(long) getpid(), \
	107	(long) lttng_gettid(), \
	108	## args, __func__); \
	109	} while(0)
	110
	111
	112	#define DBG(fmt, args...) ERRMSG(fmt, ## args)
	113	#define DBG_raw(fmt, args...) sigsafe_print_err(fmt, ## args)
	114	#define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
	115	#define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
	116	#define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
	117
	118	#if !defined(__GLIBC__) \|\| ((_POSIX_C_SOURCE >= 200112L \|\| _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
	119	/*
	120	* Version using XSI strerror_r.
	121	*/
	122	#define PERROR(call, args...) \
	123	do { \
	124	if (lttng_ust_logging_debug_enabled()) { \
	125	char perror_buf[200] = "Error in strerror_r()"; \
	126	strerror_r(errno, perror_buf, \
	127	sizeof(perror_buf)); \
	128	ERRMSG("Error: " call ": %s", ## args, \
	129	perror_buf); \
	130	} \
	131	} while(0)
	132	#else
	133	/*
	134	* Version using GNU strerror_r, for linux with appropriate defines.
	135	*/
	136	#define PERROR(call, args...) \
	137	do { \
	138	if (lttng_ust_logging_debug_enabled()) { \
	139	char *perror_buf; \
	140	char perror_tmp[200]; \
	141	perror_buf = strerror_r(errno, perror_tmp, \
	142	sizeof(perror_tmp)); \
	143	ERRMSG("Error: " call ": %s", ## args, \
	144	perror_buf); \
	145	} \
	146	} while(0)
	147	#endif
	148
	149	#define BUG_ON(condition) \
	150	do { \
	151	if (caa_unlikely(condition)) \
	152	ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
	153	} while(0)
	154	#define WARN_ON(condition) \
	155	do { \
	156	if (caa_unlikely(condition)) \
	157	WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
	158	} while(0)
	159	#define WARN_ON_ONCE(condition) WARN_ON(condition)
	160
	161	#endif /* _UST_COMMON_LOGGING_H */