X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fmacros.hpp;fp=src%2Fcommon%2Fmacros.hpp;h=d2b78200e7ebab9e7e6faffd16749f2a88082bae;hb=c9e313bc594f40a86eed237dce222c0fc99c957f;hp=0000000000000000000000000000000000000000;hpb=4878de5c7deb512bbdac4fdfc498907efa06fb7c;p=lttng-tools.git diff --git a/src/common/macros.hpp b/src/common/macros.hpp new file mode 100644 index 000000000..d2b78200e --- /dev/null +++ b/src/common/macros.hpp @@ -0,0 +1,144 @@ +/* + * Copyright (C) 2011 EfficiOS Inc. + * Copyright (C) 2011 Mathieu Desnoyers + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#ifndef _MACROS_H +#define _MACROS_H + +#include +#include +#include +#include + +/* + * Takes a pointer x and transform it so we can use it to access members + * without a function call. Here an example: + * + * #define GET_SIZE(x) LTTNG_REF(x)->size + * + * struct { int size; } s; + * + * printf("size : %d\n", GET_SIZE(&s)); + * + * For this example we can't use something like this for compatibility purpose + * since this will fail: + * + * #define GET_SIZE(x) x->size; + * + * This is mostly use for the compatibility layer of lttng-tools. See + * poll/epoll for a good example. Since x can be on the stack or allocated + * memory using malloc(), we must use generic accessors for compat in order to + * *not* use a function to access members and not the variable name. + */ +#define LTTNG_REF(x) ((typeof(*x) *)(x)) + +/* + * Memory allocation zeroed + */ +static inline +void *zmalloc(size_t len) +{ + return calloc(1, len); +} + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(array) (sizeof(array) / (sizeof((array)[0]))) +#endif + +#ifndef container_of +#define container_of(ptr, type, member) \ + ({ \ + const typeof(((type *)NULL)->member) * __ptr = (ptr); \ + (type *)((char *)__ptr - offsetof(type, member)); \ + }) +#endif + +#ifndef LTTNG_PACKED +#define LTTNG_PACKED __attribute__((__packed__)) +#endif + +#ifndef LTTNG_NO_SANITIZE_ADDRESS +#if defined(__clang__) || defined (__GNUC__) +#define LTTNG_NO_SANITIZE_ADDRESS __attribute__((no_sanitize_address)) +#else +#define LTTNG_NO_SANITIZE_ADDRESS +#endif +#endif + +#define member_sizeof(type, field) sizeof(((type *) 0)->field) + +#define ASSERT_LOCKED(lock) LTTNG_ASSERT(pthread_mutex_trylock(&lock)) +#define ASSERT_RCU_READ_LOCKED(lock) LTTNG_ASSERT(rcu_read_ongoing()) + +/* Attribute suitable to tag functions as having printf()-like arguments. */ +#define ATTR_FORMAT_PRINTF(_string_index, _first_to_check) \ + __attribute__((format(printf, _string_index, _first_to_check))) + +/* Attribute suitable to tag functions as having strftime()-like arguments. */ +#define ATTR_FORMAT_STRFTIME(_string_index) \ + __attribute__((format(strftime, _string_index, 0))) + +/* Macros used to ignore specific compiler diagnostics. */ + +#define DIAGNOSTIC_PUSH _Pragma("GCC diagnostic push") +#define DIAGNOSTIC_POP _Pragma("GCC diagnostic pop") + +#if defined(__clang__) + /* Clang */ +# define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT +# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ + _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") +# define DIAGNOSTIC_IGNORE_LOGICAL_OP +#else + /* GCC */ +# define DIAGNOSTIC_IGNORE_SUGGEST_ATTRIBUTE_FORMAT \ + _Pragma("GCC diagnostic ignored \"-Wsuggest-attribute=format\"") +# define DIAGNOSTIC_IGNORE_FORMAT_NONLITERAL \ + _Pragma("GCC diagnostic ignored \"-Wformat-nonliteral\"") +# define DIAGNOSTIC_IGNORE_LOGICAL_OP \ + _Pragma("GCC diagnostic ignored \"-Wlogical-op\"") +#endif + +/* Used to make specific C++ functions to C code. */ +#ifdef __cplusplus +#define C_LINKAGE extern "C" +#else +#define C_LINKAGE +#endif + +/* + * lttng_strncpy returns 0 on success, or nonzero on failure. + * It checks that the @src string fits into @dst_len before performing + * the copy. On failure, no copy has been performed. + * + * Assumes that 'src' is null-terminated. + * + * dst_len includes the string's trailing NULL. + */ +static inline +int lttng_strncpy(char *dst, const char *src, size_t dst_len) +{ + if (strlen(src) >= dst_len) { + /* Fail since copying would result in truncation. */ + return -1; + } + strcpy(dst, src); + return 0; +} + +#ifdef NDEBUG +/* +* Force usage of the assertion condition to prevent unused variable warnings +* when `assert()` are disabled by the `NDEBUG` definition. +*/ +# define LTTNG_ASSERT(_cond) ((void) sizeof((void) (_cond), 0)) +#else +# include +# define LTTNG_ASSERT(_cond) assert(_cond) +#endif + +#endif /* _MACROS_H */