| 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 <common/compat/string.hpp> |
| 13 | |
| 14 | #include <memory> |
| 15 | #include <pthread.h> |
| 16 | #include <stddef.h> |
| 17 | #include <stdlib.h> |
| 18 | #include <string.h> |
| 19 | #include <type_traits> |
| 20 | |
| 21 | /* |
| 22 | * Takes a pointer x and transform it so we can use it to access members |
| 23 | * without a function call. Here an example: |
| 24 | * |
| 25 | * #define GET_SIZE(x) LTTNG_REF(x)->size |
| 26 | * |
| 27 | * struct { int size; } s; |
| 28 | * |
| 29 | * printf("size : %d\n", GET_SIZE(&s)); |
| 30 | * |
| 31 | * For this example we can't use something like this for compatibility purpose |
| 32 | * since this will fail: |
| 33 | * |
| 34 | * #define GET_SIZE(x) x->size; |
| 35 | * |
| 36 | * This is mostly use for the compatibility layer of lttng-tools. See |
| 37 | * poll/epoll for a good example. Since x can be on the stack or allocated |
| 38 | * memory using malloc(), we must use generic accessors for compat in order to |
| 39 | * *not* use a function to access members and not the variable name. |
| 40 | */ |
| 41 | #define LTTNG_REF(x) ((typeof(*(x)) *) (x)) |
| 42 | |
| 43 | #ifdef NDEBUG |
| 44 | /* |
| 45 | * Force usage of the assertion condition to prevent unused variable warnings |
| 46 | * when `assert()` are disabled by the `NDEBUG` definition. |
| 47 | */ |
| 48 | #define LTTNG_ASSERT(_cond) ((void) sizeof((void) (_cond), 0)) |
| 49 | #else |
| 50 | #include <assert.h> |
| 51 | #define LTTNG_ASSERT(_cond) assert(_cond) |
| 52 | #endif |
| 53 | |
| 54 | /* |
| 55 | * Memory allocation zeroed |
| 56 | */ |
| 57 | |
| 58 | static inline void *zmalloc_internal(size_t size) |
| 59 | { |
| 60 | return calloc(1, size); |
| 61 | } |
| 62 | |
| 63 | template <typename MallocableType> |
| 64 | struct can_malloc { |
| 65 | /* |
| 66 | * gcc versions before 5.0 lack some type traits defined in C++11. |
| 67 | * Since in this instance we use the trait to prevent misuses |
| 68 | * of malloc (and statically assert) and not to generate different |
| 69 | * code based on this property, simply set value to true and allow |
| 70 | * the code to compile. Anyone using a contemporary compiler will |
| 71 | * catch the error. |
| 72 | */ |
| 73 | #if __GNUG__ && __GNUC__ < 5 |
| 74 | static constexpr bool value = true; |
| 75 | #else |
| 76 | static constexpr bool value = std::is_trivially_constructible<MallocableType>::value; |
| 77 | #endif |
| 78 | }; |
| 79 | |
| 80 | /* |
| 81 | * Malloc and zero-initialize an object of type T, asserting that MallocableType can be |
| 82 | * safely malloc-ed (is trivially constructible). |
| 83 | */ |
| 84 | template <typename MallocableType> |
| 85 | MallocableType *zmalloc() |
| 86 | { |
| 87 | static_assert(can_malloc<MallocableType>::value, "type can be malloc'ed"); |
| 88 | return (MallocableType *) zmalloc_internal(sizeof(MallocableType)); /* NOLINT sizeof |
| 89 | potentially used on a |
| 90 | pointer. */ |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * Malloc and zero-initialize a buffer of size `size`, asserting that type AllocatedType |
| 95 | * can be safely malloc-ed (is trivially constructible). |
| 96 | */ |
| 97 | template <typename AllocatedType> |
| 98 | AllocatedType *zmalloc(size_t size) |
| 99 | { |
| 100 | static_assert(can_malloc<AllocatedType>::value, "type can be malloc'ed"); |
| 101 | LTTNG_ASSERT(size >= sizeof(AllocatedType)); |
| 102 | return (AllocatedType *) zmalloc_internal(size); |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * Malloc and zero-initialize an array of `nmemb` elements of type AllocatedType, |
| 107 | * asserting that AllocatedType can be safely malloc-ed (is trivially constructible). |
| 108 | */ |
| 109 | template <typename AllocatedType> |
| 110 | AllocatedType *calloc(size_t nmemb) |
| 111 | { |
| 112 | static_assert(can_malloc<AllocatedType>::value, "type can be malloc'ed"); |
| 113 | return (AllocatedType *) zmalloc_internal(nmemb * sizeof(AllocatedType)); /* NOLINT sizeof |
| 114 | potentially |
| 115 | used on a |
| 116 | pointer. */ |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * Malloc an object of type AllocatedType, asserting that AllocatedType can be safely malloc-ed (is |
| 121 | * trivially constructible). |
| 122 | */ |
| 123 | template <typename AllocatedType> |
| 124 | AllocatedType *malloc() |
| 125 | { |
| 126 | static_assert(can_malloc<AllocatedType>::value, "type can be malloc'ed"); |
| 127 | return (AllocatedType *) malloc(sizeof(AllocatedType)); |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * Malloc a buffer of size `size`, asserting that AllocatedType can be safely |
| 132 | * malloc-ed (is trivially constructible). |
| 133 | */ |
| 134 | template <typename AllocatedType> |
| 135 | AllocatedType *malloc(size_t size) |
| 136 | { |
| 137 | static_assert(can_malloc<AllocatedType>::value, "type can be malloc'ed"); |
| 138 | return (AllocatedType *) malloc(size); |
| 139 | } |
| 140 | |
| 141 | /* |
| 142 | * Prevent using `free` on types that are non-POD. |
| 143 | * |
| 144 | * Declare a delete prototype of free if the parameter type is not safe to free |
| 145 | * (non-POD). |
| 146 | * |
| 147 | * If the parameter is a pointer to void, we can't check if what is pointed |
| 148 | * to is safe to free or not, as we don't know what is pointed to. Ideally, |
| 149 | * all calls to free would be with a typed pointer, but there are too many |
| 150 | * instances of passing a pointer to void to enforce that right now. So allow |
| 151 | * pointers to void, these will not be checked. |
| 152 | */ |
| 153 | |
| 154 | template <typename FreedType> |
| 155 | struct can_free { |
| 156 | /* |
| 157 | * gcc versions before 5.0 lack some type traits defined in C++11. |
| 158 | * Since in this instance we use the trait to prevent misuses |
| 159 | * of free (and statically assert) and not to generate different |
| 160 | * code based on this property, simply set value to true and allow |
| 161 | * the code to compile. Anyone using a contemporary compiler will |
| 162 | * catch the error. |
| 163 | */ |
| 164 | #if __GNUG__ && __GNUC__ < 5 |
| 165 | static constexpr bool value = true; |
| 166 | #else |
| 167 | static constexpr bool value = std::is_trivially_destructible<FreedType>::value || |
| 168 | std::is_void<FreedType>::value; |
| 169 | #endif |
| 170 | }; |
| 171 | |
| 172 | template <typename FreedType, typename = typename std::enable_if<!can_free<FreedType>::value>::type> |
| 173 | void free(FreedType *p) = delete; |
| 174 | |
| 175 | template <typename InitializedType> |
| 176 | struct can_memset { |
| 177 | static constexpr bool value = std::is_pod<InitializedType>::value || |
| 178 | std::is_void<InitializedType>::value; |
| 179 | }; |
| 180 | |
| 181 | template <typename InitializedType, |
| 182 | typename = typename std::enable_if<!can_memset<InitializedType>::value>::type> |
| 183 | void *memset(InitializedType *s, int c, size_t n) = delete; |
| 184 | |
| 185 | template <typename T> |
| 186 | struct can_memcpy { |
| 187 | /* |
| 188 | * gcc versions before 5.0 lack some type traits defined in C++11. |
| 189 | * Since in this instance we use the trait to prevent misuses |
| 190 | * of memcpy (and statically assert) and not to generate different |
| 191 | * code based on this property, simply set value to true and allow |
| 192 | * the code to compile. Anyone using a contemporary compiler will |
| 193 | * catch the error. |
| 194 | */ |
| 195 | #if __GNUG__ && __GNUC__ < 5 |
| 196 | static constexpr bool value = true; |
| 197 | #else |
| 198 | static constexpr bool value = std::is_trivially_copyable<T>::value; |
| 199 | #endif |
| 200 | }; |
| 201 | |
| 202 | template <typename DestinationType, |
| 203 | typename SourceType, |
| 204 | typename = typename std::enable_if<!can_memcpy<DestinationType>::value>::type, |
| 205 | typename = typename std::enable_if<!can_memcpy<SourceType>::value>::type> |
| 206 | void *memcpy(DestinationType *d, const SourceType *s, size_t n) = delete; |
| 207 | |
| 208 | template <typename MovedType> |
| 209 | struct can_memmove { |
| 210 | /* |
| 211 | * gcc versions before 5.0 lack some type traits defined in C++11. |
| 212 | * Since in this instance we use the trait to prevent misuses |
| 213 | * of memmove (and statically assert) and not to generate different |
| 214 | * code based on this property, simply set value to true and allow |
| 215 | * the code to compile. Anyone using a contemporary compiler will |
| 216 | * catch the error. |
| 217 | */ |
| 218 | #if __GNUG__ && __GNUC__ < 5 |
| 219 | static constexpr bool value = true; |
| 220 | #else |
| 221 | static constexpr bool value = std::is_trivially_copyable<MovedType>::value; |
| 222 | #endif |
| 223 | }; |
| 224 | |
| 225 | template <typename DestinationType, |
| 226 | typename SourceType, |
| 227 | typename = typename std::enable_if<!can_memmove<DestinationType>::value>::type, |
| 228 | typename = typename std::enable_if<!can_memmove<SourceType>::value>::type> |
| 229 | void *memmove(DestinationType *d, const SourceType *s, size_t n) = delete; |
| 230 | |
| 231 | #ifndef ARRAY_SIZE |
| 232 | #define ARRAY_SIZE(array) (sizeof(array) / (sizeof((array)[0]))) |
| 233 | #endif |
| 234 | |
| 235 | #ifndef LTTNG_PACKED |
| 236 | #define LTTNG_PACKED __attribute__((__packed__)) |
| 237 | #endif |
| 238 | |
| 239 | #ifndef LTTNG_NO_SANITIZE_ADDRESS |
| 240 | #if defined(__clang__) || defined(__GNUC__) |
| 241 | #define LTTNG_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address)) |
| 242 | #else |
| 243 | #define LTTNG_NO_SANITIZE_ADDRESS |
| 244 | #endif |
| 245 | #endif |
| 246 | |
| 247 | #define member_sizeof(type, field) sizeof(((type *) 0)->field) |
| 248 | |
| 249 | #define ASSERT_LOCKED(lock) LTTNG_ASSERT(pthread_mutex_trylock(&(lock))) |
| 250 | #define ASSERT_RCU_READ_LOCKED() LTTNG_ASSERT(rcu_read_ongoing()) |
| 251 | #define ASSERT_RCU_READ_UNLOCKED() LTTNG_ASSERT(!rcu_read_ongoing()) |
| 252 | |
| 253 | /* Attribute suitable to tag functions as having printf()-like arguments. */ |
| 254 | #define ATTR_FORMAT_PRINTF(_string_index, _first_to_check) \ |
| 255 | __attribute__((format(printf, _string_index, _first_to_check))) |
| 256 | |
| 257 | /* Attribute suitable to tag functions as having strftime()-like arguments. */ |
| 258 | #define ATTR_FORMAT_STRFTIME(_string_index) __attribute__((format(strftime, _string_index, 0))) |
| 259 | |
| 260 | /* Macros used to ignore specific compiler diagnostics. */ |
| 261 | |
| 262 | #define DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push") |
| 263 | #define DIAGNOSTIC_POP _Pragma("GCC diagnostic pop") |
| 264 | |
| 265 | #if defined(__clang__) |
| 266 | /* Clang */ |
| 267 | #define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT |
| 268 | #define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ |
| 269 | _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") |
| 270 | #define DIAGNOSTIC_IGNORE_LOGICAL_OP |
| 271 | #define DIAGNOSTIC_IGNORE_DUPLICATED_BRANCHES |
| 272 | #define DIAGNOSTIC_IGNORE_INVALID_OFFSETOF |
| 273 | _Pragma("GCC diagnostic ignored \"-Winvalid-offsetof\"") |
| 274 | #else |
| 275 | /* GCC */ |
| 276 | #define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT \ |
| 277 | _Pragma("GCC diagnostic ignored \"-Wsuggest-attribute=format\"") |
| 278 | #define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ |
| 279 | _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") |
| 280 | #define DIAGNOSTIC_IGNORE_LOGICAL_OP _Pragma("GCC diagnostic ignored \"-Wlogical-op\"") |
| 281 | #if __GNUG__ && __GNUC__ >= 7 |
| 282 | #define DIAGNOSTIC_IGNORE_DUPLICATED_BRANCHES \ |
| 283 | _Pragma("GCC diagnostic ignored \"-Wduplicated-branches\"") |
| 284 | #else |
| 285 | #define DIAGNOSTIC_IGNORE_DUPLICATED_BRANCHES |
| 286 | #endif /* __GNUG__ && __GNUC__ >= 7 */ |
| 287 | #define DIAGNOSTIC_IGNORE_INVALID_OFFSETOF _Pragma("GCC diagnostic ignored \"-Winvalid-offsetof\"") |
| 288 | #endif |
| 289 | |
| 290 | /* Used to make specific C++ functions to C code. */ |
| 291 | #ifdef __cplusplus |
| 292 | #define C_LINKAGE extern "C" |
| 293 | #else |
| 294 | #define C_LINKAGE |
| 295 | #endif |
| 296 | |
| 297 | /* |
| 298 | * lttng_strncpy returns 0 on success, or nonzero on failure. |
| 299 | * It checks that the @src string fits into @dst_len before performing |
| 300 | * the copy. On failure, no copy has been performed. |
| 301 | * |
| 302 | * Assumes that 'src' is null-terminated. |
| 303 | * |
| 304 | * dst_len includes the string's trailing NULL. |
| 305 | */ |
| 306 | static inline int lttng_strncpy(char *dst, const char *src, size_t dst_len) |
| 307 | { |
| 308 | if (strlen(src) >= dst_len) { |
| 309 | /* Fail since copying would result in truncation. */ |
| 310 | return -1; |
| 311 | } |
| 312 | strcpy(dst, src); |
| 313 | return 0; |
| 314 | } |
| 315 | |
| 316 | namespace lttng { |
| 317 | namespace utils { |
| 318 | template <class ParentType, class MemberType> |
| 319 | ParentType *container_of(const MemberType *member, const MemberType ParentType::*ptr_to_member) |
| 320 | { |
| 321 | const ParentType *dummy_parent = nullptr; |
| 322 | auto *offset_of_member = reinterpret_cast<const char *>(&(dummy_parent->*ptr_to_member)); |
| 323 | auto address_of_parent = reinterpret_cast<const char *>(member) - offset_of_member; |
| 324 | |
| 325 | return reinterpret_cast<ParentType *>(address_of_parent); |
| 326 | } |
| 327 | } /* namespace utils */ |
| 328 | } /* namespace lttng */ |
| 329 | |
| 330 | #endif /* _MACROS_H */ |