[lttng-tools.git] / src / common / macros.h

/*
 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#ifndef _MACROS_H
#define _MACROS_H

#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <common/compat/string.h>

/*
 * 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 is_signed(type) (((type) -1) < (type) 1)

#define member_sizeof(type, field)	sizeof(((type *) 0)->field)

#define ASSERT_LOCKED(lock) LTTNG_ASSERT(pthread_mutex_trylock(&lock))

/*
 * 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.
 *
 * dst_len includes the string's trailing NULL.
 */
static inline
int lttng_strncpy(char *dst, const char *src, size_t dst_len)
{
	if (lttng_strnlen(src, dst_len) >= 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 <assert.h>
# define LTTNG_ASSERT(_cond) assert(_cond)
#endif

#endif /* _MACROS_H */
Commit	Line	Data
990570ed	1	/*
ab5be9fa MJ	2	* Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
ab5be9fa MJ	3	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
990570ed	4	*
ab5be9fa	5	* SPDX-License-Identifier: GPL-2.0-only
990570ed	6	*
990570ed DG	7	*/
	8
	9	#ifndef _MACROS_H
	10	#define _MACROS_H
	11
	12	#include <stdlib.h>
93375aa6	13	#include <stddef.h>
f6835b82	14	#include <string.h>
639082d2	15	#include <common/compat/string.h>
990570ed DG	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	*/
4616a46c MD	42	static inline
	43	void *zmalloc(size_t len)
	44	{
	45	return calloc(1, len);
	46	}
990570ed DG	47
	48	#ifndef ARRAY_SIZE
	49	#define ARRAY_SIZE(array) (sizeof(array) / (sizeof((array)[0])))
	50	#endif
	51
93375aa6 JG	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
54c90d10 DG	60	#ifndef LTTNG_PACKED
	61	#define LTTNG_PACKED __attribute__((__packed__))
	62	#endif
	63
1405051a FD	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
0c634962	72	#define is_signed(type) (((type) -1) < (type) 1)
159b042f	73
f8f3885c MD	74	#define member_sizeof(type, field) sizeof(((type *) 0)->field)
f8f3885c MD	75
a0377dfe	76	#define ASSERT_LOCKED(lock) LTTNG_ASSERT(pthread_mutex_trylock(&lock))
5e5c14ce	77
f6835b82 MD	78	/*
	79	* lttng_strncpy returns 0 on success, or nonzero on failure.
	80	* It checks that the @src string fits into @dst_len before performing
	81	* the copy. On failure, no copy has been performed.
	82	*
	83	* dst_len includes the string's trailing NULL.
	84	*/
	85	static inline
	86	int lttng_strncpy(char dst, const char src, size_t dst_len)
	87	{
c3ef76cd	88	if (lttng_strnlen(src, dst_len) >= dst_len) {
f6835b82 MD	89	/* Fail since copying would result in truncation. */
	90	return -1;
	91	}
c3ef76cd	92	strcpy(dst, src);
f6835b82 MD	93	return 0;
	94	}
	95
a0377dfe FD	96	#ifdef NDEBUG
	97	/*
	98	* Force usage of the assertion condition to prevent unused variable warnings
	99	* when `assert()` are disabled by the `NDEBUG` definition.
	100	*/
	101	# define LTTNG_ASSERT(_cond) ((void) sizeof((void) (_cond), 0))
	102	#else
	103	# include <assert.h>
	104	# define LTTNG_ASSERT(_cond) assert(_cond)
	105	#endif
	106
990570ed	107	#endif /* _MACROS_H */