include/ust/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 <sys/syscall.h>
  26 #include <errno.h>
  27 #include <stdarg.h>
  28 #include <stdio.h>
  29
  30 #include <ust/core.h>
  31
  32 #include <ust/share.h>
  33
  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
  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 UST_XSTR(d) UST_STR(d)
  55 #define UST_STR(s) #s
  56
  57 #define USTERR_MAX_LEN  512
  58
  59 /* We sometimes print in the tracing path, and tracing can occur in
  60  * signal handlers, so we must use a print method which is signal safe.
  61  */
  62
  63 extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...)
  64         __attribute__ ((format (printf, 3, 4)));
  65
  66 static inline void __attribute__ ((format (printf, 1, 2)))
  67         __check_ust_safe_fmt(const char *fmt, ...)
  68 {
  69 }
  70
  71 #define sigsafe_print_err(fmt, args...)                                 \
  72 {                                                                       \
  73         /* Can't use dynamic allocation. Limit ourselves to USTERR_MAX_LEN chars. */ \
  74         char ____buf[USTERR_MAX_LEN];                                   \
  75         int ____saved_errno;                                            \
  76                                                                         \
  77         /* Save the errno. */                                           \
  78         ____saved_errno = errno;                                        \
  79                                                                         \
  80         ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args);      \
  81                                                                         \
  82         /* Add end of string in case of buffer overflow. */             \
  83         ____buf[sizeof(____buf) - 1] = 0;                               \
  84                                                                         \
  85         patient_write(STDERR_FILENO, ____buf, strlen(____buf));         \
  86         /*                                                              \
  87          * Can't print errors because we are in the error printing code \
  88          * path.                                                        \
  89          */                                                             \
  90                                                                         \
  91         /* Restore errno, in order to be async-signal safe. */          \
  92         errno = ____saved_errno;                                        \
  93 }
  94
  95 #define UST_STR_COMPONENT UST_XSTR(UST_COMPONENT)
  96
  97 #define ERRMSG(fmt, args...)                    \
  98         do {                                    \
  99                 sigsafe_print_err(UST_STR_COMPONENT "[%ld/%ld]: " fmt " (in %s() at " __FILE__ ":" UST_XSTR(__LINE__) ")\n",    \
 100                 (long) getpid(),                \
 101                 (long) syscall(SYS_gettid),     \
 102                 ## args, __func__);             \
 103                 fflush(stderr);                 \
 104         } while(0)
 105
 106 #ifdef UST_DEBUG
 107 # define DBG(fmt, args...)                      ERRMSG(fmt, ## args)
 108 # define DBG_raw(fmt, args...)                                  \
 109         do {                                                    \
 110                 sigsafe_print_err(fmt, ## args);                \
 111                 fflush(stderr);                                 \
 112         } while(0)
 113 #else
 114 # define DBG(fmt, args...)                                      \
 115         do {                                                    \
 116                 if (ust_debug())                                \
 117                         ERRMSG(fmt, ## args);                   \
 118         } while (0)
 119 # define DBG_raw(fmt, args...)                                  \
 120         do {                                                    \
 121                 if (ust_debug()) {                              \
 122                         sigsafe_print_err(fmt, ## args);        \
 123                         fflush(stderr);                         \
 124                 }                                               \
 125         } while(0)
 126 #endif
 127 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
 128 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
 129 #define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
 130
 131 #if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
 132 #define PERROR(call, args...)\
 133         do { \
 134                 char buf[200] = "Error in strerror_r()"; \
 135                 strerror_r(errno, buf, sizeof(buf)); \
 136                 ERRMSG("Error: " call ": %s", ## args, buf); \
 137         } while(0);
 138 #else
 139 #define PERROR(call, args...)\
 140         do { \
 141                 char *buf; \
 142                 char tmp[200]; \
 143                 buf = strerror_r(errno, tmp, sizeof(tmp)); \
 144                 ERRMSG("Error: " call ": %s", ## args, buf); \
 145         } while(0);
 146 #endif
 147
 148 #define BUG_ON(condition)                                       \
 149         do {                                                    \
 150                 if (caa_unlikely(condition))                    \
 151                         ERR("condition not respected (BUG) on line %s:%d", __FILE__, __LINE__); \
 152         } while(0)
 153 #define WARN_ON(condition)                                      \
 154         do {                                                    \
 155                 if (caa_unlikely(condition))                    \
 156                         WARN("condition not respected on line %s:%d", __FILE__, __LINE__); \
 157         } while(0)
 158 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 159
 160 #endif /* _USTERR_SIGNAL_SAFE_H */