clock-correlation-validator: add clock correlation validation util
[babeltrace.git] / src / common / macros.h
1 /*
2 * SPDX-License-Identifier: MIT
3 *
4 * Copyright 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
5 */
6
7 #ifndef _BABELTRACE_INTERNAL_H
8 #define _BABELTRACE_INTERNAL_H
9
10 #ifdef __cplusplus
11 extern "C" {
12 #endif
13
14 #ifdef __cplusplus
15 #define BT_EXTERN_C extern "C"
16 #else
17 #define BT_EXTERN_C
18 #endif
19
20 #define bt_max_t(type, a, b) \
21 ((type) (a) > (type) (b) ? (type) (a) : (type) (b))
22
23 /*
24 * BT_EXPORT: set the visibility for exported functions.
25 */
26 #if defined(_WIN32) || defined(__CYGWIN__)
27 #define BT_EXPORT
28 #else
29 #define BT_EXPORT __attribute__((visibility("default")))
30 #endif
31
32 /*
33 * BT_NOEXCEPT: defined to `noexcept` if compiling as C++, else empty.
34 */
35 #if defined(__cplusplus)
36 #define BT_NOEXCEPT noexcept
37 #else
38 #define BT_NOEXCEPT
39 #endif
40
41 /* Enable `txt` if developer mode is enabled. */
42 #ifdef BT_DEV_MODE
43 #define BT_IF_DEV_MODE(txt) txt
44 #else
45 #define BT_IF_DEV_MODE(txt)
46 #endif
47
48 /*
49 * Yield `ref`'s value while setting `ref` to NULL.
50 *
51 * This can be used to give a strong reference to a callee:
52 *
53 * add_foo_to_list(list, BT_MOVE_REF(foo));
54 *
55 * or in a simple assignment:
56 *
57 * my_struct->foo = BT_MOVE_REF(foo);
58 *
59 * When moving a reference in a function call, the reference is given to the
60 * callee even if that function call fails, so make sure the called function
61 * is written accordingly.
62 */
63
64 #define BT_MOVE_REF(ref) \
65 ({ \
66 __typeof__(ref) _ref = ref; \
67 ref = NULL; \
68 _ref; \
69 })
70
71 /* Wrapper for g_array_index that adds bound checking. */
72 #define bt_g_array_index(a, t, i) \
73 g_array_index((a), t, ({ BT_ASSERT_DBG((i) < (a)->len); (i); }))
74
75 /*
76 * Copied from:
77 * <https://stackoverflow.com/questions/37411809/how-to-elegantly-fix-this-unused-variable-warning/37412551#37412551>:
78 *
79 * * sizeof() ensures that the expression is not evaluated at all, so
80 * its side-effects don't happen. That is to be consistent with the
81 * usual behaviour of debug-only constructs, such as assert().
82 *
83 * * `((_expr), 0)` uses the comma operator to swallow the actual type
84 * of `(_expr)`. This is to prevent VLAs from triggering evaluation.
85 *
86 * * `(void)` explicitly ignores the result of `(_expr)` and sizeof() so
87 * no "unused value" warning appears.
88 */
89
90 #define BT_USE_EXPR(_expr) ((void) sizeof((void) (_expr), 0))
91 #define BT_USE_EXPR2(_expr1, _expr2) \
92 ((void) sizeof((void) (_expr1), (void) (_expr2), 0))
93 #define BT_USE_EXPR3(_expr1, _expr2, _expr3) \
94 ((void) sizeof((void) (_expr1), (void) (_expr2), (void) (_expr3), 0))
95 #define BT_USE_EXPR4(_expr1, _expr2, _expr3, _expr4) \
96 ((void) sizeof((void) (_expr1), (void) (_expr2), \
97 (void) (_expr3), (void) (_expr4), 0))
98 #define BT_USE_EXPR5(_expr1, _expr2, _expr3, _expr4, _expr5) \
99 ((void) sizeof((void) (_expr1), (void) (_expr2), \
100 (void) (_expr3), (void) (_expr4), (void) (_expr5), 0))
101
102 #if defined __clang__
103 # if __has_warning("-Wunused-but-set-variable")
104 # define BT_DIAG_IGNORE_UNUSED_BUT_SET_VARIABLE \
105 _Pragma("GCC diagnostic ignored \"-Wunused-but-set-variable\"")
106 # endif
107 #endif
108
109 #if !defined BT_DIAG_IGNORE_UNUSED_BUT_SET_VARIABLE
110 # define BT_DIAG_IGNORE_UNUSED_BUT_SET_VARIABLE
111 #endif
112
113 #ifdef __cplusplus
114 }
115 #endif
116
117 #endif
This page took 0.031766 seconds and 4 git commands to generate.