src/lib/assert-cond-base.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2018 EfficiOS Inc. and Linux Foundation
   5  * Copyright (c) 2018-2020 Philippe Proulx <pproulx@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_ASSERT_COND_BASE_INTERNAL_H
   9 #define BABELTRACE_ASSERT_COND_BASE_INTERNAL_H
  10
  11 /*
  12  * The macros in this header use macros defined in "lib/logging.h". We
  13  * don't want this header to automatically include "lib/logging.h"
  14  * because you need to manually define BT_LOG_TAG before including
  15  * "lib/logging.h" and it is unexpected that you also need to define it
  16  * before including this header.
  17  *
  18  * This is a reminder that in order to use "lib/assert-cond.h", you also
  19  * need to use logging explicitly.
  20  */
  21
  22 #ifndef BT_LIB_LOG_SUPPORTED
  23 # error Include "lib/logging.h" before this header.
  24 #endif
  25
  26 #include <stdbool.h>
  27 #include "common/macros.h"
  28
  29 /*
  30  * Prints the details of an unsatisfied precondition or postcondition
  31  * without immediately aborting. You should use this within a function
  32  * which checks preconditions or postconditions, but which is called
  33  * from a BT_ASSERT_PRE() or BT_ASSERT_POST() context, so that the
  34  * function can still return its result for
  35  * BT_ASSERT_PRE()/BT_ASSERT_POST() to evaluate it.
  36  *
  37  * Example:
  38  *
  39  *     static inline bool check_complex_precond(...)
  40  *     {
  41  *         ...
  42  *
  43  *         if (...) {
  44  *             BT_ASSERT_COND_MSG("Invalid object: ...", ...);
  45  *             return false;
  46  *         }
  47  *
  48  *         ...
  49  *     }
  50  *
  51  *     ...
  52  *
  53  *     BT_ASSERT_PRE(check_complex_precond(...),
  54  *                   "Precondition is not satisfied: ...", ...);
  55  */
  56 #define BT_ASSERT_COND_MSG(_fmt, ...)                                   \
  57         do {                                                            \
  58                 bt_lib_log(__FILE__, __func__,                          \
  59                         __LINE__, BT_LOG_FATAL, BT_LOG_TAG,             \
  60                         (_fmt), ##__VA_ARGS__);                         \
  61         } while (0)
  62
  63 /*
  64  * This function:
  65  *
  66  * 1. Generates a condition ID based on `cond_type`, `func`, and
  67  *    `id_suffix`.
  68  *
  69  * 2. Logs (FATAL level) the generated condition ID and function name
  70  *    (`func`).
  71  *
  72  * 3. Logs (FATAL level) a message using `fmt` and the optional
  73  *    arguments (same usage as BT_LIB_LOGF()).
  74  *
  75  * 4. Aborts.
  76  */
  77 __attribute__((noreturn))
  78 void bt_lib_assert_cond_failed(const char *cond_type, const char *func,
  79                 const char *id_suffix, const char *fmt, ...);
  80
  81 /*
  82  * Internal to this file: asserts that the library condition `_cond` of
  83  * type `_cond_type` (`pre` or `post`), related to function `_func`,
  84  * and having the ID suffix `_id_suffix` is satisfied.
  85  *
  86  * If `_cond` is false, then this macro calls
  87  * bt_lib_assert_cond_failed().
  88  *
  89  * To assert that an _internal_ precondition or postcondition is
  90  * satisfied, use BT_ASSERT() or BT_ASSERT_DBG().
  91  */
  92 #define _BT_ASSERT_COND(_cond_type, _func, _id_suffix, _cond, _fmt, ...) \
  93         do {                                                            \
  94                 if (!(_cond)) {                                         \
  95                         bt_lib_assert_cond_failed(_cond_type, _func,    \
  96                                 _id_suffix, _fmt, ##__VA_ARGS__);       \
  97                 }                                                       \
  98         } while (0)
  99
 100 /*
 101  * Asserts that the library precondition `_cond` is satisfied.
 102  *
 103  * See _BT_ASSERT_COND() for details about the `_func` and `_id_suffix`
 104  * parameters.
 105  */
 106 #define BT_ASSERT_PRE_FROM_FUNC(_func, _id_suffix, _cond, _fmt, ...)    \
 107         _BT_ASSERT_COND("pre", _func, _id_suffix, (_cond), _fmt, ##__VA_ARGS__)
 108
 109 /*
 110  * Like BT_ASSERT_PRE_FROM_FUNC(), but uses `__func__` (current function
 111  * name) as the `_func` parameter.
 112  */
 113 #define BT_ASSERT_PRE(_id_suffix, _cond, _fmt, ...)                     \
 114         BT_ASSERT_PRE_FROM_FUNC(__func__, _id_suffix, (_cond), _fmt, ##__VA_ARGS__)
 115
 116 /*
 117  * Asserts that the library postcondition `_cond` is satisfied.
 118  *
 119  * See _BT_ASSERT_COND() for details about the `_func` and `_id_suffix`
 120  * parameters.
 121  */
 122 #define BT_ASSERT_POST(_func, _id_suffix, _cond, _fmt, ...)                             \
 123         _BT_ASSERT_COND("post", _func, _id_suffix, (_cond), _fmt, ##__VA_ARGS__);
 124
 125 #ifdef BT_DEV_MODE
 126 /* Developer mode version of BT_ASSERT_PRE_FROM_FUNC(). */
 127 # define BT_ASSERT_PRE_DEV_FROM_FUNC(_func, _id_suffix, _cond, _fmt, ...) \
 128         BT_ASSERT_PRE_FROM_FUNC(_func, _id_suffix, (_cond), _fmt, ##__VA_ARGS__)
 129
 130 /* Developer mode version of BT_ASSERT_PRE(). */
 131 # define BT_ASSERT_PRE_DEV(_id_suffix, _cond, _fmt, ...)                \
 132         BT_ASSERT_PRE(_id_suffix, (_cond), _fmt, ##__VA_ARGS__)
 133
 134 /* Developer mode version of BT_ASSERT_POST(). */
 135 # define BT_ASSERT_POST_DEV(_func, _id_suffix, _cond, _fmt, ...)        \
 136         BT_ASSERT_POST(_func, _id_suffix, (_cond), _fmt, ##__VA_ARGS__)
 137
 138 /* Developer mode version of BT_ASSERT_COND_MSG(). */
 139 # define BT_ASSERT_COND_DEV_MSG(_fmt, ...)                              \
 140         BT_ASSERT_COND_MSG(_fmt, ##__VA_ARGS__)
 141
 142 /*
 143  * Marks a function as being only used within a BT_ASSERT_PRE_DEV() or
 144  * BT_ASSERT_POST_DEV() context.
 145  */
 146 # define BT_ASSERT_COND_DEV_FUNC
 147 #else
 148 # define BT_ASSERT_COND_DEV_MSG(_fmt, ...)
 149
 150 # define BT_ASSERT_PRE_DEV_FROM_FUNC(_func, _id_suffix, _cond, _fmt, ...) \
 151         BT_USE_EXPR4(_func, _id_suffix, _cond, _fmt)
 152
 153 # define BT_ASSERT_PRE_DEV(_id_suffix, _cond, _fmt, ...)                \
 154         BT_USE_EXPR3(_id_suffix, _cond, _fmt)
 155
 156 # define BT_ASSERT_POST_DEV(_func, _id_suffix, _cond, _fmt, ...)        \
 157         BT_USE_EXPR4(_func, _id_suffix, _cond, _fmt)
 158
 159 # define BT_ASSERT_COND_DEV_FUNC        __attribute__((unused))
 160 #endif /* BT_DEV_MODE */
 161
 162 /*
 163  * Mark anything that includes this file as supporting precondition and
 164  * postcondition assertion macros.
 165  */
 166 #define BT_ASSERT_COND_SUPPORTED
 167
 168 #endif /* BABELTRACE_ASSERT_COND_BASE_INTERNAL_H */