src/lib/assert-post.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2019 EfficiOS Inc. and Linux Foundation
   5  * Copyright (c) 2019 Philippe Proulx <pproulx@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_ASSERT_POST_INTERNAL_H
   9 #define BABELTRACE_ASSERT_POST_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-post.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/macros.h"
  30 #include "common/common.h"
  31
  32 /*
  33  * Prints the details of an unsatisfied postcondition without
  34  * immediately aborting. You should use this within a function which
  35  * checks postconditions, but which is called from a
  36  * BT_ASSERT_POST() context, so that the function can still return
  37  * its result for BT_ASSERT_POST() to evaluate it.
  38  *
  39  * Example:
  40  *
  41  *     BT_ASSERT_POST_FUNC
  42  *     static inline bool check_complex_postcond(...)
  43  *     {
  44  *         ...
  45  *
  46  *         if (...) {
  47  *             BT_ASSERT_POST_MSG("Unexpected status: ...", ...);
  48  *             return false;
  49  *         }
  50  *
  51  *         ...
  52  *     }
  53  *
  54  *     ...
  55  *
  56  *     BT_ASSERT_POST(check_complex_postcond(...),
  57  *                         "Postcondition is not satisfied: ...", ...);
  58  */
  59 #define BT_ASSERT_POST_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  * Asserts that the library postcondition `_cond` is satisfied.
  68  *
  69  * If `_cond` is false, log a fatal statement using `_fmt` and the
  70  * optional arguments (same usage as BT_LIB_LOGF()), and abort.
  71  *
  72  * To assert that a library precondition is satisfied (parameters from
  73  * the user), use BT_ASSERT_PRE().
  74  *
  75  * To assert that an internal postcondition is satisfied, use
  76  * BT_ASSERT() or BT_ASSERT_DBG().
  77  */
  78 #define BT_ASSERT_POST(_cond, _fmt, ...)                                \
  79         do {                                                            \
  80                 if (!(_cond)) {                                         \
  81                         BT_ASSERT_POST_MSG("Babeltrace 2 library postcondition not satisfied; error is:"); \
  82                         BT_ASSERT_POST_MSG(_fmt, ##__VA_ARGS__);        \
  83                         BT_ASSERT_POST_MSG("Aborting...");              \
  84                         bt_common_abort();                                      \
  85                 }                                                       \
  86         } while (0)
  87
  88 /*
  89  * Asserts that if there's an error on the current thread, an error status code
  90  * was returned.  Puts back the error in place (if there is one) such that if
  91  * the assertion hits, it will be possible to inspect it with a debugger.
  92  */
  93 #define BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(_status)                     \
  94         do {                                                                    \
  95                 const struct bt_error *err = bt_current_thread_take_error();    \
  96                 if (err) {                                                      \
  97                         bt_current_thread_move_error(err);                      \
  98                 }                                                               \
  99                 BT_ASSERT_POST(_status < 0 || !err,                             \
 100                         "Current thread has an error, but user function "       \
 101                         "returned a non-error status: status=%s",               \
 102                         bt_common_func_status_string(_status));                 \
 103         } while (0)
 104
 105 /*
 106  * Asserts that the current thread has no error.
 107  */
 108 #define BT_ASSERT_POST_NO_ERROR() \
 109         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(0)
 110
 111 /*
 112  * Marks a function as being only used within a BT_ASSERT_POST()
 113  * context.
 114  */
 115 #define BT_ASSERT_POST_FUNC
 116
 117 #ifdef BT_DEV_MODE
 118 /* Developer mode version of BT_ASSERT_POST_MSG(). */
 119 # define BT_ASSERT_POST_DEV_MSG(_fmt, ...)                              \
 120         BT_ASSERT_POST_MSG(_fmt, ##__VA_ARGS__)
 121
 122 /* Developer mode version of BT_ASSERT_POST(). */
 123 # define BT_ASSERT_POST_DEV(_cond, _fmt, ...)                           \
 124         BT_ASSERT_POST((_cond), _fmt, ##__VA_ARGS__)
 125
 126 /* Developer mode version of BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(). */
 127 # define BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(_status) \
 128         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(_status)
 129
 130 /* Developer mode version of `BT_ASSERT_POST_FUNC`. */
 131 # define BT_ASSERT_POST_DEV_FUNC BT_ASSERT_POST_FUNC
 132 #else
 133 # define BT_ASSERT_POST_DEV_MSG(_fmt, ...)
 134 # define BT_ASSERT_POST_DEV(_cond, _fmt, ...)   ((void) sizeof((void) (_cond), 0))
 135 # define BT_ASSERT_POST_DEV_NO_ERROR_IF_NO_ERROR_STATUS(_status) \
 136         ((void) sizeof((void) (_status), 0))
 137 # define BT_ASSERT_POST_DEV_FUNC        __attribute__((unused))
 138 #endif /* BT_DEV_MODE */
 139
 140 #define BT_ASSERT_POST_SUPPORTED
 141
 142 #endif /* BABELTRACE_ASSERT_POST_INTERNAL_H */