src/lib/assert-pre.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2018 EfficiOS Inc. and Linux Foundation
   5  * Copyright (c) 2018 Philippe Proulx <pproulx@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_ASSERT_PRE_INTERNAL_H
   9 #define BABELTRACE_ASSERT_PRE_INTERNAL_H
  10
  11 /*
  12  * The macros in this header use macros defined in "lib/logging.h".
  13  * We don't want this header to automatically include
  14  * "lib/logging.h" because you need to manually define BT_LOG_TAG
  15  * before including "lib/logging.h" and it is unexpected that you
  16  * also need to define it before including this header.
  17  *
  18  * This is a reminder that in order to use "lib/assert-pre.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 without immediately
  34  * aborting. You should use this within a function which checks
  35  * preconditions, but which is called from a BT_ASSERT_PRE() context, so
  36  * that the function can still return its result for BT_ASSERT_PRE() to
  37  * evaluate it.
  38  *
  39  * Example:
  40  *
  41  *     static inline bool check_complex_precond(...)
  42  *     {
  43  *         ...
  44  *
  45  *         if (...) {
  46  *             BT_ASSERT_PRE_MSG("Invalid object: ...", ...);
  47  *             return false;
  48  *         }
  49  *
  50  *         ...
  51  *     }
  52  *
  53  *     ...
  54  *
  55  *     BT_ASSERT_PRE(check_complex_precond(...),
  56  *                   "Precondition is not satisfied: ...", ...);
  57  */
  58 #define BT_ASSERT_PRE_MSG(_fmt, ...)                                    \
  59         do {                                                            \
  60                 bt_lib_log(_BT_LOG_SRCLOC_FUNCTION, __FILE__,           \
  61                         __LINE__, BT_LOG_FATAL, BT_LOG_TAG,             \
  62                         (_fmt), ##__VA_ARGS__);                         \
  63         } while (0)
  64
  65 /*
  66  * Asserts that the library precondition `_cond` is satisfied.
  67  *
  68  * If `_cond` is false, log a fatal statement using `_fmt` and the
  69  * optional arguments (same usage as BT_LIB_LOGF()), and abort.
  70  *
  71  * To assert that a library postcondition is satisfied (return from user
  72  * code), use BT_ASSERT_POST().
  73  *
  74  * To assert that an internal postcondition is satisfied, use
  75  * BT_ASSERT() or BT_ASSERT_DBG().
  76  */
  77 #define BT_ASSERT_PRE(_cond, _fmt, ...)                         \
  78         do {                                                            \
  79                 if (!(_cond)) {                                         \
  80                         BT_ASSERT_PRE_MSG("Babeltrace 2 library precondition not satisfied; error is:"); \
  81                         BT_ASSERT_PRE_MSG(_fmt, ##__VA_ARGS__); \
  82                         BT_ASSERT_PRE_MSG("Aborting...");               \
  83                         bt_common_abort();                                      \
  84                 }                                                       \
  85         } while (0)
  86
  87 /*
  88  * Asserts that a given variable `_obj` named `_obj_name` (capitalized)
  89  * is not `NULL`.
  90  */
  91 #define BT_ASSERT_PRE_NON_NULL(_obj, _obj_name)                         \
  92         BT_ASSERT_PRE((_obj), "%s is NULL: ", _obj_name)
  93
  94 /*
  95  * Asserts that a given index `_index` is less than a given length
  96  * `_length`.
  97  */
  98 #define BT_ASSERT_PRE_VALID_INDEX(_index, _length)                      \
  99         BT_ASSERT_PRE((_index) < (_length),                             \
 100                 "Index is out of bounds: index=%" PRIu64 ", "           \
 101                 "count=%" PRIu64, (uint64_t) (_index), (uint64_t) (_length))
 102
 103 /*
 104  * Asserts that the current thread has no error set.
 105  */
 106 #define BT_ASSERT_PRE_NO_ERROR() \
 107         do {                                                                    \
 108                 const struct bt_error *err = bt_current_thread_take_error();    \
 109                 if (err) {                                                      \
 110                         bt_current_thread_move_error(err);                      \
 111                 }                                                               \
 112                 BT_ASSERT_PRE(!err,                                             \
 113                         "API function called while current thread has an "      \
 114                         "error: function=%s", __func__);                        \
 115         } while (0)
 116
 117 #ifdef BT_DEV_MODE
 118 /* Developer mode version of BT_ASSERT_PRE_MSG(). */
 119 # define BT_ASSERT_PRE_DEV_MSG(_fmt, ...)                               \
 120         BT_ASSERT_PRE_MSG(_fmt, ##__VA_ARGS__)
 121
 122 /* Developer mode version of BT_ASSERT_PRE(). */
 123 # define BT_ASSERT_PRE_DEV(_cond, _fmt, ...)                            \
 124         BT_ASSERT_PRE((_cond), _fmt, ##__VA_ARGS__)
 125
 126 /* Developer mode version of BT_ASSERT_PRE_NON_NULL() */
 127 # define BT_ASSERT_PRE_DEV_NON_NULL(_obj, _obj_name)                    \
 128         BT_ASSERT_PRE_NON_NULL((_obj), (_obj_name))
 129
 130 /*
 131  * Developer mode: asserts that a given object `_obj` named `_obj_name`
 132  * (capitalized) is NOT frozen. This macro checks the `frozen` field of
 133  * `_obj`.
 134  *
 135  * This currently only exists in developer mode because some freezing
 136  * functions can be called on the fast path, so they too are only
 137  * enabled in developer mode.
 138  */
 139 # define BT_ASSERT_PRE_DEV_HOT(_obj, _obj_name, _fmt, ...)              \
 140         BT_ASSERT_PRE(!(_obj)->frozen, "%s is frozen" _fmt, _obj_name,  \
 141                 ##__VA_ARGS__)
 142
 143 /* Developer mode version of BT_ASSERT_PRE_VALID_INDEX() */
 144 # define BT_ASSERT_PRE_DEV_VALID_INDEX(_index, _length)                 \
 145         BT_ASSERT_PRE_VALID_INDEX((_index), (_length))
 146
 147 /* Developer mode version of BT_ASSERT_PRE_NO_ERROR(). */
 148 # define BT_ASSERT_PRE_DEV_NO_ERROR() \
 149         BT_ASSERT_PRE_NO_ERROR()
 150
 151 /*
 152  * Marks a function as being only used within a BT_ASSERT_PRE_DEV()
 153  * context.
 154  */
 155 # define BT_ASSERT_PRE_DEV_FUNC
 156 #else
 157 # define BT_ASSERT_PRE_DEV_MSG(_fmt, ...)
 158 # define BT_ASSERT_PRE_DEV(_cond, _fmt, ...)    ((void) sizeof((void) (_cond), 0))
 159 # define BT_ASSERT_PRE_DEV_NON_NULL(_obj, _obj_name)                    \
 160         ((void) sizeof((void) (_obj), (void) (_obj_name), 0))
 161 # define BT_ASSERT_PRE_DEV_HOT(_obj, _obj_name, _fmt, ...)              \
 162         ((void) sizeof((void) (_obj), (void) (_obj_name), 0))
 163 # define BT_ASSERT_PRE_DEV_VALID_INDEX(_index, _length)                 \
 164         ((void) sizeof((void) (_index), (void) (_length), 0))
 165 # define BT_ASSERT_PRE_DEV_NO_ERROR()
 166 # define BT_ASSERT_PRE_DEV_FUNC         __attribute__((unused))
 167 #endif /* BT_DEV_MODE */
 168
 169 #define BT_ASSERT_PRE_SUPPORTED
 170
 171 #endif /* BABELTRACE_ASSERT_PRE_INTERNAL_H */