include/usterr_signal_safe.h

   1 /* Copyright (C) 2009  Pierre-Marc Fournier
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #ifndef _USTERR_SIGNAL_SAFE_H
  19 #define _USTERR_SIGNAL_SAFE_H
  20
  21 #include <string.h>
  22 #include <sys/types.h>
  23 #include <sys/syscall.h>
  24 #include <errno.h>
  25 #include <stdarg.h>
  26 #include <stdio.h>
  27
  28 #include <ust/core.h>
  29
  30 #include "share.h"
  31
  32 #ifndef UST_COMPONENT
  33 //#error UST_COMPONENT is undefined
  34 #define UST_COMPONENT libust
  35 #endif
  36
  37 /* To stringify the expansion of a define */
  38 #define XSTR(d) STR(d)
  39 #define STR(s) #s
  40
  41 /* We sometimes print in the tracing path, and tracing can occur in
  42  * signal handlers, so we must use a print method which is signal safe.
  43  */
  44
  45 extern int ust_safe_snprintf(char *str, size_t n, const char *fmt, ...)
  46         __attribute__ ((format (printf, 3, 4)));
  47
  48 static inline void __attribute__ ((format (printf, 1, 2)))
  49         __check_ust_safe_fmt(const char *fmt, ...)
  50 {
  51 }
  52
  53 #define sigsafe_print_err(fmt, args...) \
  54 { \
  55         /* Can't use dynamic allocation. Limit ourselves to 250 chars. */ \
  56         char ____buf[250]; \
  57         int ____saved_errno; \
  58 \
  59         /* Save the errno. */ \
  60         ____saved_errno = errno; \
  61 \
  62         ust_safe_snprintf(____buf, sizeof(____buf), fmt, ## args); \
  63 \
  64         /* Add end of string in case of buffer overflow. */ \
  65         ____buf[sizeof(____buf)-1] = 0; \
  66 \
  67         patient_write(STDERR_FILENO, ____buf, strlen(____buf)); \
  68         /* Can't print errors because we are in the error printing code path. */ \
  69 \
  70         /* Restore errno, in order to be async-signal safe. */ \
  71         errno = ____saved_errno; \
  72 }
  73
  74 #define UST_STR_COMPONENT XSTR(UST_COMPONENT)
  75
  76 #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)
  77
  78 #ifdef UST_DEBUG
  79 # define DBG(fmt, args...) ERRMSG(fmt, ## args)
  80 # define DBG_raw(fmt, args...) do { sigsafe_print_err(fmt, ## args); fflush(stderr); } while(0)
  81 #else
  82 # define DBG(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
  83 # define DBG_raw(fmt, args...) __check_ust_safe_fmt(fmt, ## args)
  84 #endif
  85 #define WARN(fmt, args...) ERRMSG("Warning: " fmt, ## args)
  86 #define ERR(fmt, args...) ERRMSG("Error: " fmt, ## args)
  87 #define BUG(fmt, args...) ERRMSG("BUG: " fmt, ## args)
  88
  89 #if (_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600) && !defined(_GNU_SOURCE)
  90 #define PERROR(call, args...)\
  91         do { \
  92                 char buf[200] = "Error in strerror_r()"; \
  93                 strerror_r(errno, buf, sizeof(buf)); \
  94                 ERRMSG("Error: " call ": %s", ## args, buf); \
  95         } while(0);
  96 #else
  97 #define PERROR(call, args...)\
  98         do { \
  99                 char *buf; \
 100                 char tmp[200]; \
 101                 buf = strerror_r(errno, tmp, sizeof(tmp)); \
 102                 ERRMSG("Error: " call ": %s", ## args, buf); \
 103         } while(0);
 104 #endif
 105
 106 #define BUG_ON(condition) do { if (unlikely(condition)) ERR("condition not respected (BUG)"); } while(0)
 107 #define WARN_ON(condition) do { if (unlikely(condition)) WARN("condition not respected on line %s:%d", __FILE__, __LINE__); } while(0)
 108 #define WARN_ON_ONCE(condition) WARN_ON(condition)
 109
 110 #endif /* _USTERR_SIGNAL_SAFE_H */