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 <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
  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 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
  69 #define sigsafe_print_err(fmt, args...)                                 \
  70 {                                                                       \
  71         /* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
  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;                                        \
  91 }
  92
  93 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
  94
  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)
 103
 104 #ifdef UST_DEBUG
 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)
 111 #else
 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)
 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
 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)
 156 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 157
 158
 159 #endif /* _USTERR_SIGNAL_SAFE_H */