Fix: relayd: rotation failure for multi-domain session
[lttng-tools.git] / src / common / macros.h
1 /*
2 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
3 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * SPDX-License-Identifier: GPL-2.0-only
6 *
7 */
8
9 #ifndef _MACROS_H
10 #define _MACROS_H
11
12 #include <stdlib.h>
13 #include <stddef.h>
14 #include <string.h>
15 #include <common/compat/string.h>
16
17 /*
18 * Takes a pointer x and transform it so we can use it to access members
19 * without a function call. Here an example:
20 *
21 * #define GET_SIZE(x) LTTNG_REF(x)->size
22 *
23 * struct { int size; } s;
24 *
25 * printf("size : %d\n", GET_SIZE(&s));
26 *
27 * For this example we can't use something like this for compatibility purpose
28 * since this will fail:
29 *
30 * #define GET_SIZE(x) x->size;
31 *
32 * This is mostly use for the compatibility layer of lttng-tools. See
33 * poll/epoll for a good example. Since x can be on the stack or allocated
34 * memory using malloc(), we must use generic accessors for compat in order to
35 * *not* use a function to access members and not the variable name.
36 */
37 #define LTTNG_REF(x) ((typeof(*x) *)(x))
38
39 /*
40 * Memory allocation zeroed
41 */
42 static inline
43 void *zmalloc(size_t len)
44 {
45 return calloc(1, len);
46 }
47
48 #ifndef ARRAY_SIZE
49 #define ARRAY_SIZE(array) (sizeof(array) / (sizeof((array)[0])))
50 #endif
51
52 #ifndef container_of
53 #define container_of(ptr, type, member) \
54 ({ \
55 const typeof(((type *)NULL)->member) * __ptr = (ptr); \
56 (type *)((char *)__ptr - offsetof(type, member)); \
57 })
58 #endif
59
60 #ifndef LTTNG_PACKED
61 #define LTTNG_PACKED __attribute__((__packed__))
62 #endif
63
64 #ifndef LTTNG_NO_SANITIZE_ADDRESS
65 #if defined(__clang__) || defined (__GNUC__)
66 #define LTTNG_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address))
67 #else
68 #define LTTNG_NO_SANITIZE_ADDRESS
69 #endif
70 #endif
71
72 #define is_signed(type) (((type) -1) < (type) 1)
73
74 #define member_sizeof(type, field) sizeof(((type *) 0)->field)
75
76 #define ASSERT_LOCKED(lock) LTTNG_ASSERT(pthread_mutex_trylock(&lock))
77
78 /* Attribute suitable to tag functions as having printf()-like arguments. */
79 #define ATTR_FORMAT_PRINTF(_string_index, _first_to_check) \
80 __attribute__((format(printf, _string_index, _first_to_check)))
81
82 /* Attribute suitable to tag functions as having strftime()-like arguments. */
83 #define ATTR_FORMAT_STRFTIME(_string_index) \
84 __attribute__((format(strftime, _string_index, 0)))
85
86 /* Macros used to ignore specific compiler diagnostics. */
87
88 #define DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push")
89 #define DIAGNOSTIC_POP _Pragma("GCC diagnostic pop")
90
91 #if defined(__clang__)
92 /* Clang */
93 # define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT
94 # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
95 _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
96 #else
97 /* GCC */
98 # define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT \
99 _Pragma("GCC diagnostic ignored \"-Wsuggest-attribute=format\"")
100 # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \
101 _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"")
102 #endif
103
104 /* Used to make specific C++ functions to C code. */
105 #ifdef __cplusplus
106 #define C_LINKAGE extern "C"
107 #else
108 #define C_LINKAGE
109 #endif
110
111 /*
112 * lttng_strncpy returns 0 on success, or nonzero on failure.
113 * It checks that the @src string fits into @dst_len before performing
114 * the copy. On failure, no copy has been performed.
115 *
116 * dst_len includes the string's trailing NULL.
117 */
118 static inline
119 int lttng_strncpy(char *dst, const char *src, size_t dst_len)
120 {
121 if (lttng_strnlen(src, dst_len) >= dst_len) {
122 /* Fail since copying would result in truncation. */
123 return -1;
124 }
125 strcpy(dst, src);
126 return 0;
127 }
128
129 #ifdef NDEBUG
130 /*
131 * Force usage of the assertion condition to prevent unused variable warnings
132 * when `assert()` are disabled by the `NDEBUG` definition.
133 */
134 # define LTTNG_ASSERT(_cond) ((void) sizeof((void) (_cond), 0))
135 #else
136 # include <assert.h>
137 # define LTTNG_ASSERT(_cond) assert(_cond)
138 #endif
139
140 #endif /* _MACROS_H */
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