src/lib/assert-cond.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_INTERNAL_H
   9 #define BABELTRACE_ASSERT_COND_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 <stdlib.h>
  28 #include <inttypes.h>
  29 #include "common/common.h"
  30 #include "common/macros.h"
  31
  32 /*
  33  * Prints the details of an unsatisfied precondition or postcondition
  34  * without immediately aborting. You should use this within a function
  35  * which checks preconditions or postconditions, but which is called
  36  * from a BT_ASSERT_PRE() or BT_ASSERT_POST() context, so that the
  37  * function can still return its result for
  38  * BT_ASSERT_PRE()/BT_ASSERT_POST() to evaluate it.
  39  *
  40  * Example:
  41  *
  42  *     static inline bool check_complex_precond(...)
  43  *     {
  44  *         ...
  45  *
  46  *         if (...) {
  47  *             BT_ASSERT_COND_MSG("Invalid object: ...", ...);
  48  *             return false;
  49  *         }
  50  *
  51  *         ...
  52  *     }
  53  *
  54  *     ...
  55  *
  56  *     BT_ASSERT_PRE(check_complex_precond(...),
  57  *                   "Precondition is not satisfied: ...", ...);
  58  */
  59 #define BT_ASSERT_COND_MSG(_fmt, ...)                                   \
  60         do {                                                            \
  61                 bt_lib_log(_BT_LOG_SRCLOC_FUNCTION, __FILE__,           \
  62                         __LINE__, BT_LOG_FATAL, BT_LOG_TAG,             \
  63                         (_fmt), ##__VA_ARGS__);                         \
  64         } while (0)
  65
  66 /*
  67  * Internal to this file: asserts that the library condition `_cond` of
  68  * type `_cond_type` (`pre` or `post`) is satisfied.
  69  *
  70  * If `_cond` is false, this macro logs a fatal message using `_fmt` and
  71  * the optional arguments (same usage as BT_LIB_LOGF()), and abort.
  72  *
  73  * To assert that an internal precondition or postcondition is
  74  * satisfied, use BT_ASSERT() or BT_ASSERT_DBG().
  75  */
  76 #define _BT_ASSERT_COND(_cond_type, _cond, _fmt, ...)                   \
  77         do {                                                            \
  78                 if (!(_cond)) {                                         \
  79                         BT_ASSERT_COND_MSG("Babeltrace 2 library " _cond_type "condition not satisfied. Error is:"); \
  80                         BT_ASSERT_COND_MSG(_fmt, ##__VA_ARGS__);        \
  81                         BT_ASSERT_COND_MSG("Aborting...");              \
  82                         bt_common_abort();                              \
  83                 }                                                       \
  84         } while (0)
  85
  86 /*
  87  * Asserts that the library precondition `_cond` is satisfied.
  88  *
  89  * If `_cond` is false, log a fatal message using `_fmt` and the
  90  * optional arguments (same usage as BT_LIB_LOGF()), and abort.
  91  *
  92  * To assert that a library postcondition is satisfied (return from user
  93  * code), use BT_ASSERT_POST().
  94  *
  95  * To assert that an internal precondition or postcondition is
  96  * satisfied, use BT_ASSERT() or BT_ASSERT_DBG().
  97  */
  98 #define BT_ASSERT_PRE(_cond, _fmt, ...)                                 \
  99         _BT_ASSERT_COND("pre", _cond, _fmt, ##__VA_ARGS__)
 100
 101 /*
 102  * Asserts that the library postcondition `_cond` is satisfied.
 103  *
 104  * If `_cond` is false, log a fatal message using `_fmt` and the
 105  * optional arguments (same usage as BT_LIB_LOGF()), and abort.
 106  *
 107  * To assert that a library precondition is satisfied (return from user
 108  * code), use BT_ASSERT_PRE().
 109  *
 110  * To assert that an internal precondition or postcondition is
 111  * satisfied, use BT_ASSERT() or BT_ASSERT_DBG().
 112  */
 113 #define BT_ASSERT_POST(_cond, _fmt, ...)                                        \
 114         _BT_ASSERT_COND("post", _cond, _fmt, ##__VA_ARGS__)
 115
 116 /*
 117  * Asserts that a given variable `_obj` named `_obj_name` (capitalized)
 118  * is not `NULL`.
 119  */
 120 #define BT_ASSERT_PRE_NON_NULL(_obj, _obj_name)                         \
 121         BT_ASSERT_PRE((_obj), "%s is NULL: ", _obj_name)
 122
 123 /*
 124  * Asserts that a given index `_index` is less than a given length
 125  * `_length`.
 126  */
 127 #define BT_ASSERT_PRE_VALID_INDEX(_index, _length)                      \
 128         BT_ASSERT_PRE((_index) < (_length),                             \
 129                 "Index is out of bounds: index=%" PRIu64 ", "           \
 130                 "count=%" PRIu64, (uint64_t) (_index), (uint64_t) (_length))
 131
 132 /*
 133  * Asserts that the current thread has no error set.
 134  */
 135 #define BT_ASSERT_PRE_NO_ERROR() \
 136         do {                                                                    \
 137                 const struct bt_error *err = bt_current_thread_take_error();    \
 138                 if (err) {                                                      \
 139                         bt_current_thread_move_error(err);                      \
 140                 }                                                               \
 141                 BT_ASSERT_PRE(!err,                                             \
 142                         "API function called while current thread has an "      \
 143                         "error: function=%s", __func__);                        \
 144         } while (0)
 145
 146 /*
 147  * Asserts that, if the current thread has an error, `_status` is an
 148  * error status code.
 149  *
 150  * Puts back the error in place (if there is one) such that if this
 151  * macro aborts, it will be possible to inspect it with a debugger.
 152  */
 153 #define BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(_status)                     \
 154         do {                                                                    \
 155                 const struct bt_error *err = bt_current_thread_take_error();    \
 156                 if (err) {                                                      \
 157                         bt_current_thread_move_error(err);                      \
 158                 }                                                               \
 159                 BT_ASSERT_POST(_status < 0 || !err,                             \
 160                         "Current thread has an error, but user function "       \
 161                         "returned a non-error status: status=%s",               \
 162                         bt_common_func_status_string(_status));                 \
 163         } while (0)
 164
 165 /*
 166  * Asserts that the current thread has no error.
 167  */
 168 #define BT_ASSERT_POST_NO_ERROR() \
 169         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(0)
 170
 171 #ifdef BT_DEV_MODE
 172 /* Developer mode version of BT_ASSERT_PRE(). */
 173 # define BT_ASSERT_PRE_DEV(_cond, _fmt, ...)                            \
 174         BT_ASSERT_PRE((_cond), _fmt, ##__VA_ARGS__)
 175
 176 /* Developer mode version of BT_ASSERT_PRE_NON_NULL() */
 177 # define BT_ASSERT_PRE_DEV_NON_NULL(_obj, _obj_name)                    \
 178         BT_ASSERT_PRE_NON_NULL((_obj), (_obj_name))
 179
 180 /*
 181  * Developer mode: asserts that a given object `_obj` named `_obj_name`
 182  * (capitalized) is NOT frozen. This macro checks the `frozen` field of
 183  * `_obj`.
 184  *
 185  * This currently only exists in developer mode because some freezing
 186  * functions can be called on the fast path, so they too are only
 187  * enabled in developer mode.
 188  */
 189 # define BT_ASSERT_PRE_DEV_HOT(_obj, _obj_name, _fmt, ...)              \
 190         BT_ASSERT_PRE(!(_obj)->frozen, "%s is frozen" _fmt, _obj_name,  \
 191                 ##__VA_ARGS__)
 192
 193 /* Developer mode version of BT_ASSERT_PRE_VALID_INDEX() */
 194 # define BT_ASSERT_PRE_DEV_VALID_INDEX(_index, _length)                 \
 195         BT_ASSERT_PRE_VALID_INDEX((_index), (_length))
 196
 197 /* Developer mode version of BT_ASSERT_PRE_NO_ERROR(). */
 198 # define BT_ASSERT_PRE_DEV_NO_ERROR() \
 199         BT_ASSERT_PRE_NO_ERROR()
 200
 201 /* Developer mode version of BT_ASSERT_POST(). */
 202 # define BT_ASSERT_POST_DEV(_cond, _fmt, ...)                           \
 203         BT_ASSERT_POST((_cond), _fmt, ##__VA_ARGS__)
 204
 205 /*
 206  * Developer mode version of
 207  * BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS().
 208  */
 209 # define BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(_status) \
 210         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(_status)
 211
 212 /* Developer mode version of BT_ASSERT_POST_NO_ERROR(). */
 213 # define BT_ASSERT_POST_DEV_NO_ERROR()  \
 214         BT_ASSERT_POST_NO_ERROR()
 215
 216 /* Developer mode version of BT_ASSERT_COND_MSG(). */
 217 # define BT_ASSERT_COND_DEV_MSG(_fmt, ...)                              \
 218         BT_ASSERT_COND_MSG(_fmt, ##__VA_ARGS__)
 219
 220 /*
 221  * Marks a function as being only used within a BT_ASSERT_PRE_DEV() or
 222  * BT_ASSERT_POST_DEV() context.
 223  */
 224 # define BT_ASSERT_COND_DEV_FUNC
 225 #else
 226 # define BT_ASSERT_COND_DEV_MSG(_fmt, ...)
 227 # define BT_ASSERT_PRE_DEV(_cond, _fmt, ...)    ((void) sizeof((void) (_cond), 0))
 228 # define BT_ASSERT_PRE_DEV_NON_NULL(_obj, _obj_name)                    \
 229         ((void) sizeof((void) (_obj), (void) (_obj_name), 0))
 230 # define BT_ASSERT_PRE_DEV_HOT(_obj, _obj_name, _fmt, ...)              \
 231         ((void) sizeof((void) (_obj), (void) (_obj_name), 0))
 232 # define BT_ASSERT_PRE_DEV_VALID_INDEX(_index, _length)                 \
 233         ((void) sizeof((void) (_index), (void) (_length), 0))
 234 # define BT_ASSERT_PRE_DEV_NO_ERROR()
 235 # define BT_ASSERT_POST_DEV(_cond, _fmt, ...)   ((void) sizeof((void) (_cond), 0))
 236 # define BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(_status) \
 237         ((void) sizeof((void) (_status), 0))
 238 # define BT_ASSERT_POST_DEV_NO_ERROR()
 239 # define BT_ASSERT_COND_DEV_FUNC        __attribute__((unused))
 240 #endif /* BT_DEV_MODE */
 241
 242 /*
 243  * Mark anything that includes this file as supporting precondition and
 244  * postcondition assertion macros.
 245  */
 246 #define BT_ASSERT_COND_SUPPORTED
 247
 248 #endif /* BABELTRACE_ASSERT_COND_INTERNAL_H */