| 1 | /* |
| 2 | * Copyright (C) 2011 EfficiOS Inc. |
| 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 | #define ASSERT_RCU_READ_LOCKED(lock) LTTNG_ASSERT(rcu_read_ongoing()) |
| 78 | |
| 79 | /* Attribute suitable to tag functions as having printf()-like arguments. */ |
| 80 | #define ATTR_FORMAT_PRINTF(_string_index, _first_to_check) \ |
| 81 | __attribute__((format(printf, _string_index, _first_to_check))) |
| 82 | |
| 83 | /* Attribute suitable to tag functions as having strftime()-like arguments. */ |
| 84 | #define ATTR_FORMAT_STRFTIME(_string_index) \ |
| 85 | __attribute__((format(strftime, _string_index, 0))) |
| 86 | |
| 87 | /* Macros used to ignore specific compiler diagnostics. */ |
| 88 | |
| 89 | #define DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push") |
| 90 | #define DIAGNOSTIC_POP _Pragma("GCC diagnostic pop") |
| 91 | |
| 92 | #if defined(__clang__) |
| 93 | /* Clang */ |
| 94 | # define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT |
| 95 | # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ |
| 96 | _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") |
| 97 | #else |
| 98 | /* GCC */ |
| 99 | # define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT \ |
| 100 | _Pragma("GCC diagnostic ignored \"-Wsuggest-attribute=format\"") |
| 101 | # define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ |
| 102 | _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") |
| 103 | #endif |
| 104 | |
| 105 | /* Used to make specific C++ functions to C code. */ |
| 106 | #ifdef __cplusplus |
| 107 | #define C_LINKAGE extern "C" |
| 108 | #else |
| 109 | #define C_LINKAGE |
| 110 | #endif |
| 111 | |
| 112 | /* |
| 113 | * lttng_strncpy returns 0 on success, or nonzero on failure. |
| 114 | * It checks that the @src string fits into @dst_len before performing |
| 115 | * the copy. On failure, no copy has been performed. |
| 116 | * |
| 117 | * dst_len includes the string's trailing NULL. |
| 118 | */ |
| 119 | static inline |
| 120 | int lttng_strncpy(char *dst, const char *src, size_t dst_len) |
| 121 | { |
| 122 | if (lttng_strnlen(src, dst_len) >= dst_len) { |
| 123 | /* Fail since copying would result in truncation. */ |
| 124 | return -1; |
| 125 | } |
| 126 | strcpy(dst, src); |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | #ifdef NDEBUG |
| 131 | /* |
| 132 | * Force usage of the assertion condition to prevent unused variable warnings |
| 133 | * when `assert()` are disabled by the `NDEBUG` definition. |
| 134 | */ |
| 135 | # define LTTNG_ASSERT(_cond) ((void) sizeof((void) (_cond), 0)) |
| 136 | #else |
| 137 | # include <assert.h> |
| 138 | # define LTTNG_ASSERT(_cond) assert(_cond) |
| 139 | #endif |
| 140 | |
| 141 | #endif /* _MACROS_H */ |