src/common/assert.h

   1 #ifndef BABELTRACE_ASSERT_INTERNAL_H
   2 #define BABELTRACE_ASSERT_INTERNAL_H
   3
   4 /*
   5  * Copyright (c) 2018-2019 EfficiOS Inc. and Linux Foundation
   6  * Copyright (c) 2018-2019 Philippe Proulx <pproulx@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24  * SOFTWARE.
  25  */
  26
  27 #include <assert.h>
  28 #include <glib.h>
  29
  30 #include "common/macros.h"
  31
  32 BT_HIDDEN
  33 extern void bt_common_assert_failed(const char *file, int line,
  34                 const char *func, const char *assertion)
  35                 __attribute__((noreturn));
  36
  37 /*
  38  * Internal assertion (to detect logic errors on which the library user
  39  * has no influence). Use BT_ASSERT_PRE*() or BT_ASSERT_POST*() to check
  40  * preconditions or postconditions which must be directly or indirectly
  41  * satisfied by the library user.
  42  *
  43  * BT_ASSERT() is enabled in both debug and non-debug modes.
  44  */
  45 #define BT_ASSERT(_cond)                                                       \
  46         do {                                                                   \
  47                 if (!(_cond)) {                                                \
  48                         bt_common_assert_failed(__FILE__, __LINE__, __func__,  \
  49                                 G_STRINGIFY(_cond));                           \
  50                 }                                                              \
  51         } while (0)
  52
  53 /*
  54  * Marks a function as being only used within a BT_ASSERT() context.
  55  */
  56 #define BT_ASSERT_FUNC
  57
  58 #ifdef BT_DEBUG_MODE
  59
  60 /*
  61  * Debug mode internal assertion.
  62  */
  63 #define BT_ASSERT_DBG(_cond)    BT_ASSERT(_cond)
  64
  65 /*
  66  * Marks a function as being only used within a BT_ASSERT_DBG() context.
  67  */
  68 #define BT_ASSERT_DBG_FUNC
  69
  70 #else /* BT_DEBUG_MODE */
  71
  72 /*
  73  * When `BT_DEBUG_MODE` is _not_ defined, define BT_ASSERT_DBG() macro
  74  * to the following to trick the compiler into thinking that the
  75  * variable passed as condition to the assertion is used. This is to
  76  * prevent set-but-not-used warnings from the compiler when assertions
  77  * are disabled. The sizeof() operator also makes sure that the `_cond`
  78  * expression is not evaluated, thus preventing unwanted side effects.
  79  *
  80  * In-depth explanation:
  81  * https://stackoverflow.com/questions/37411809/how-to-elegantly-fix-this-unused-variable-warning/37412551#37412551
  82  */
  83 # define BT_ASSERT_DBG(_cond)   ((void) sizeof((void) (_cond), 0))
  84 # define BT_ASSERT_DBG_FUNC     __attribute__((unused))
  85
  86 #endif /* BT_DEBUG_MODE */
  87
  88 #endif /* BABELTRACE_ASSERT_INTERNAL_H */