src/lib/logging.c

   1 /*
   2  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #include <stdlib.h>
  24 #include <babeltrace2/logging.h>
  25 #include <babeltrace2/version.h>
  26
  27 #define BT_LOG_TAG "LIB/LOGGING"
  28 #include "lib/logging.h"
  29
  30 #ifdef BT_DEV_MODE
  31 /*
  32  * Default log level is FATAL in developer mode because fatal logging is
  33  * our way to communicate an unsatisfied precondition and the details.
  34  */
  35 # define DEFAULT_LOG_LEVEL      BT_LOG_FATAL
  36 #else
  37 /*
  38  * In non-developer mode, use NONE by default: we don't print logging
  39  * statements for any executable which links with the library. The
  40  * executable must call bt_logging_set_global_level() or the
  41  * executable's user must set the `LIBBABELTRACE2_INIT_LOG_LEVEL`
  42  * environment variable to enable logging.
  43  */
  44 # define DEFAULT_LOG_LEVEL      BT_LOG_NONE
  45 #endif /* BT_DEV_MODE */
  46
  47 /*
  48  * This is exported because even though the Python plugin provider is a
  49  * different shared object for packaging purposes, it's still considered
  50  * part of the library and therefore needs the library's run-time log
  51  * level.
  52  */
  53 int bt_lib_log_level = DEFAULT_LOG_LEVEL;
  54
  55 enum bt_logging_level bt_logging_get_minimal_level(void)
  56 {
  57         return BT_LOG_LEVEL;
  58 }
  59
  60 enum bt_logging_level bt_logging_get_global_level(void)
  61 {
  62         return bt_lib_log_level;
  63 }
  64
  65 void bt_logging_set_global_level(enum bt_logging_level log_level)
  66 {
  67 #ifdef BT_DEV_MODE
  68         /*
  69          * Do not allow the library's log level to fall to NONE when in
  70          * developer mode because fatal logging is our way to
  71          * communicate an unsatisfied precondition and the details.
  72          */
  73         if (log_level == BT_LOG_NONE) {
  74                 log_level = BT_LOG_FATAL;
  75         }
  76 #endif
  77
  78         bt_lib_log_level = log_level;
  79 }
  80
  81 static
  82 void __attribute__((constructor)) bt_logging_ctor(void)
  83 {
  84         const char *v_extra = bt_version_get_extra() ? bt_version_get_extra() :
  85                 "";
  86
  87         bt_logging_set_global_level(
  88                 bt_log_get_level_from_env("LIBBABELTRACE2_INIT_LOG_LEVEL"));
  89         BT_LOGI("Babeltrace %d.%d.%d%s library loaded: "
  90                 "major=%d, minor=%d, patch=%d, extra=\"%s\"",
  91                 bt_version_get_major(), bt_version_get_minor(),
  92                 bt_version_get_patch(), v_extra,
  93                 bt_version_get_major(), bt_version_get_minor(),
  94                 bt_version_get_patch(), v_extra);
  95 }