[lttng-ust.git] / include / lttng / ust-utils.h

/*
 * SPDX-License-Identifier: MIT
 *
 * Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 */

#ifndef _LTTNG_UST_UTILS_H
#define _LTTNG_UST_UTILS_H

#include <stdio.h>
#include <stdlib.h>
#include <urcu/compiler.h>

/* For lttng_ust_is_integer_type */
#if defined (__cplusplus)
#include <type_traits>
#endif


/**
 * lttng_ust_stringify - convert a literal value to a C string
 */
#define __lttng_ust_stringify1(x)	#x
#define lttng_ust_stringify(x)	__lttng_ust_stringify1(x)

/**
 * lttng_ust_is_signed_type - check if type is signed
 *
 * Returns true if the type of @type is signed.
 */
#define lttng_ust_is_signed_type(type)           ((type) -1 < (type) 1)


/**
 * lttng_ust_is_integer_type - check if type is an integer
 *
 * Returns true if the type of @type is an integer.
 */
#if defined(__cplusplus)
#define lttng_ust_is_integer_type(type) (std::is_integral<type>::value)
#else
#define lttng_ust_is_integer_type(type) \
		(__builtin_types_compatible_p(type, _Bool) || \
		__builtin_types_compatible_p(type, char) || \
		__builtin_types_compatible_p(type, signed char) || \
		__builtin_types_compatible_p(type, unsigned char) || \
		__builtin_types_compatible_p(type, short) || \
		__builtin_types_compatible_p(type, unsigned short) || \
		__builtin_types_compatible_p(type, int) || \
		__builtin_types_compatible_p(type, unsigned int) || \
		__builtin_types_compatible_p(type, long) || \
		__builtin_types_compatible_p(type, unsigned long) || \
		__builtin_types_compatible_p(type, long long) || \
		__builtin_types_compatible_p(type, unsigned long long))
#endif

/**
 * lttng_ust_ctf_array_element_type_is_supported -
 *
 * Adds a compilation assertion that CTF arrays and sequences declared by the
 * user are of an integral type.
 */
#define lttng_ust_ctf_array_element_type_is_supported(type, item) \
		lttng_static_assert(lttng_ust_is_integer_type(type), \
			"Non-integer type `" #item "` not supported as element of CTF_ARRAY or CTF_SEQUENCE", \
			Non_integer_type__##item##__not_supported_as_element_of_CTF_ARRAY_or_CTF_SEQUENCE);


/**
 * lttng_ust_runtime_bug_on - check condition at runtime
 * @condition: the condition which should be false.
 *
 * If the condition is true, a BUG will be triggered at runtime.
 */
#define lttng_ust_runtime_bug_on(condition)				\
	do {								\
		if (caa_unlikely(condition)) {				\
			fprintf(stderr,					\
				"LTTng BUG in file %s, line %d.\n",	\
				__FILE__, __LINE__);			\
			exit(EXIT_FAILURE);				\
		}							\
	} while (0)


/**
 * lttng_ust_build_bug_on - check condition at build
 * @condition: the condition which should be false.
 *
 * If the condition is true, the compiler will generate a build error.
 */
#define lttng_ust_build_bug_on(condition)			\
	((void) sizeof(char[-!!(condition)]))


/**
 * lttng_ust_build_runtime_bug_on - check condition at build (if constant) or runtime
 * @condition: the condition which should be false.
 *
 * If the condition is a constant and true, the compiler will generate a build
 * error. If the condition is not constant, a BUG will be triggered at runtime
 * if the condition is ever true. If the condition is constant and false, no
 * code is emitted.
 */
#define lttng_ust_build_runtime_bug_on(condition)		\
	do {							\
		if (__builtin_constant_p(condition))		\
			lttng_ust_build_bug_on(condition);	\
		else						\
			lttng_ust_runtime_bug_on(condition);	\
	} while (0)


/**
 * lttng_ust_offset_align - Calculate the offset needed to align an object on
 *                its natural alignment towards higher addresses.
 * @align_drift:  object offset from an "alignment"-aligned address.
 * @alignment:    natural object alignment. Must be non-zero, power of 2.
 *
 * Returns the offset that must be added to align towards higher
 * addresses.
 */
#define lttng_ust_offset_align(align_drift, alignment)			       \
	({								       \
		lttng_ust_build_runtime_bug_on((alignment) == 0		       \
				   || ((alignment) & ((alignment) - 1)));      \
		(((alignment) - (align_drift)) & ((alignment) - 1));	       \
	})


/**
 * lttng_ust_offset_align_floor - Calculate the offset needed to align an
 *                object on its natural alignment towards lower addresses.
 * @align_drift:  object offset from an "alignment"-aligned address.
 * @alignment:    natural object alignment. Must be non-zero, power of 2.
 *
 * Returns the offset that must be substracted to align towards lower addresses.
 */
#define lttng_ust_offset_align_floor(align_drift, alignment)		       \
	({								       \
		lttng_ust_build_runtime_bug_on((alignment) == 0		       \
				   || ((alignment) & ((alignment) - 1)));      \
		(((align_drift) - (alignment)) & ((alignment) - 1));	       \
	})

#endif /* _LTTNG_UST_UTILS_H */
Commit	Line	Data
eae3c729 MJ	1	/*
	2	* SPDX-License-Identifier: MIT
	3	*
	4	* Copyright (C) 2010-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	5	*/
	6
	7	#ifndef _LTTNG_UST_UTILS_H
	8	#define _LTTNG_UST_UTILS_H
	9
	10	#include <stdio.h>
	11	#include <stdlib.h>
	12	#include <urcu/compiler.h>
	13
	14	/* For lttng_ust_is_integer_type */
	15	#if defined (__cplusplus)
	16	#include <type_traits>
	17	#endif
	18
	19
	20	/**
	21	* lttng_ust_stringify - convert a literal value to a C string
	22	*/
	23	#define __lttng_ust_stringify1(x) #x
	24	#define lttng_ust_stringify(x) __lttng_ust_stringify1(x)
	25
	26	/**
	27	* lttng_ust_is_signed_type - check if type is signed
	28	*
	29	* Returns true if the type of @type is signed.
	30	*/
	31	#define lttng_ust_is_signed_type(type) ((type) -1 < (type) 1)
	32
	33
	34	/**
	35	* lttng_ust_is_integer_type - check if type is an integer
	36	*
	37	* Returns true if the type of @type is an integer.
	38	*/
	39	#if defined(__cplusplus)
	40	#define lttng_ust_is_integer_type(type) (std::is_integral<type>::value)
	41	#else
	42	#define lttng_ust_is_integer_type(type) \
	43	(__builtin_types_compatible_p(type, _Bool) \|\| \
	44	__builtin_types_compatible_p(type, char) \|\| \
d465835d	45	__builtin_types_compatible_p(type, signed char) \|\| \
eae3c729 MJ	46	__builtin_types_compatible_p(type, unsigned char) \|\| \
	47	__builtin_types_compatible_p(type, short) \|\| \
	48	__builtin_types_compatible_p(type, unsigned short) \|\| \
	49	__builtin_types_compatible_p(type, int) \|\| \
	50	__builtin_types_compatible_p(type, unsigned int) \|\| \
	51	__builtin_types_compatible_p(type, long) \|\| \
	52	__builtin_types_compatible_p(type, unsigned long) \|\| \
	53	__builtin_types_compatible_p(type, long long) \|\| \
	54	__builtin_types_compatible_p(type, unsigned long long))
	55	#endif
	56
	57	/**
	58	* lttng_ust_ctf_array_element_type_is_supported -
	59	*
	60	* Adds a compilation assertion that CTF arrays and sequences declared by the
	61	* user are of an integral type.
	62	*/
	63	#define lttng_ust_ctf_array_element_type_is_supported(type, item) \
	64	lttng_static_assert(lttng_ust_is_integer_type(type), \
	65	"Non-integer type `" #item "` not supported as element of CTF_ARRAY or CTF_SEQUENCE", \
	66	Non_integer_type__##item##__not_supported_as_element_of_CTF_ARRAY_or_CTF_SEQUENCE);
	67
	68
	69	/**
	70	* lttng_ust_runtime_bug_on - check condition at runtime
	71	* @condition: the condition which should be false.
	72	*
	73	* If the condition is true, a BUG will be triggered at runtime.
	74	*/
	75	#define lttng_ust_runtime_bug_on(condition) \
	76	do { \
	77	if (caa_unlikely(condition)) { \
	78	fprintf(stderr, \
	79	"LTTng BUG in file %s, line %d.\n", \
	80	__FILE__, __LINE__); \
	81	exit(EXIT_FAILURE); \
	82	} \
	83	} while (0)
	84
	85
	86	/**
	87	* lttng_ust_build_bug_on - check condition at build
	88	* @condition: the condition which should be false.
	89	*
	90	* If the condition is true, the compiler will generate a build error.
	91	*/
	92	#define lttng_ust_build_bug_on(condition) \
	93	((void) sizeof(char[-!!(condition)]))
	94
	95
	96	/**
	97	* lttng_ust_build_runtime_bug_on - check condition at build (if constant) or runtime
	98	* @condition: the condition which should be false.
	99	*
	100	* If the condition is a constant and true, the compiler will generate a build
	101	* error. If the condition is not constant, a BUG will be triggered at runtime
	102	* if the condition is ever true. If the condition is constant and false, no
	103	* code is emitted.
	104	*/
	105	#define lttng_ust_build_runtime_bug_on(condition) \
	106	do { \
	107	if (__builtin_constant_p(condition)) \
	108	lttng_ust_build_bug_on(condition); \
	109	else \
110	lttng_ust_runtime_bug_on(condition); \
111	} while (0)
112
113
114	/**
115	* lttng_ust_offset_align - Calculate the offset needed to align an object on
116	* its natural alignment towards higher addresses.
117	* @align_drift: object offset from an "alignment"-aligned address.
118	* @alignment: natural object alignment. Must be non-zero, power of 2.
119	*
120	* Returns the offset that must be added to align towards higher
121	* addresses.
122	*/
123	#define lttng_ust_offset_align(align_drift, alignment) \
124	({ \
125	lttng_ust_build_runtime_bug_on((alignment) == 0 \
126	\|\| ((alignment) & ((alignment) - 1))); \
127	(((alignment) - (align_drift)) & ((alignment) - 1)); \
128	})
129
130
131	/**
132	* lttng_ust_offset_align_floor - Calculate the offset needed to align an
133	* object on its natural alignment towards lower addresses.
134	* @align_drift: object offset from an "alignment"-aligned address.
135	* @alignment: natural object alignment. Must be non-zero, power of 2.
136	*
137	* Returns the offset that must be substracted to align towards lower addresses.
138	*/
139	#define lttng_ust_offset_align_floor(align_drift, alignment) \
140	({ \
141	lttng_ust_build_runtime_bug_on((alignment) == 0 \
142	\|\| ((alignment) & ((alignment) - 1))); \
143	(((align_drift) - (alignment)) & ((alignment) - 1)); \
144	})
145
146	#endif /* _LTTNG_UST_UTILS_H */