include/usterr-signal-safe.h

   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 static inline int ust_debug(void)
  41 {
  42         return ust_loglevel == UST_LOGLEVEL_DEBUG;
  43 }
  44
  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 */
  51 #define UST_XSTR(d) UST_STR(d)
  52 #define UST_STR(s) #s
  53
  54 #define USTERR_MAX_LEN  512
  55
  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
  68 /* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */
  69 /* Add end of string in case of buffer overflow. */
  70 #define sigsafe_print_err(fmt, args...)                                 \
  71 do {                                                                    \
  72         char ____buf[USTERR_MAX_LEN];                                   \
  73         int ____saved_errno;                                            \
  74         ____saved_errno = errno;        /* signal-safety */             \
  75         ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args);      \
  76         ____buf[sizeof(____buf) - 1] = 0;                               \
  77         patient_write(STDERR_FILENO, ____buf, strlen(____buf));         \
  78         errno = ____saved_errno;        /* signal-safety */             \
  79 } while (0)
  80
  81 #define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
  82
  83 #define ERRMSG(fmt, args...)                    \
  84         do {                                    \
  85                 sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n",    \
  86                 (long) getpid(),                \
  87                 (long) gettid(),                \
  88                 ## args, __func__);             \
  89                 fflush(stderr);                 \
  90         } while(0)
  91
  92 #ifdef LTTNG_UST_DEBUG
  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)
  99 #else
 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)
 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
 117 #if !defined(__linux__) || ((_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE))
 118 /*
 119  * Version using XSI strerror_r.
 120  */
 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
 128 /*
 129  * Version using GNU strerror_r, for linux with appropriate defines.
 130  */
 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
 140 #define BUG_ON(condition)                                       \
 141         do {                                                    \
 142                 if (caa_unlikely(condition))                    \
 143                         ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
 144         } while(0)
 145 #define WARN_ON(condition)                                      \
 146         do {                                                    \
 147                 if (caa_unlikely(condition))                    \
 148                         WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
 149         } while(0)
 150 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 151
 152 #endif /* _USTERR_SIGNAL_SAFE_H */