[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, 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) \|\| \
	45	__builtin_types_compatible_p(type, unsigned char) \|\| \
	46	__builtin_types_compatible_p(type, short) \|\| \
	47	__builtin_types_compatible_p(type, unsigned short) \|\| \
	48	__builtin_types_compatible_p(type, int) \|\| \
	49	__builtin_types_compatible_p(type, unsigned int) \|\| \
	50	__builtin_types_compatible_p(type, long) \|\| \
	51	__builtin_types_compatible_p(type, unsigned long) \|\| \
	52	__builtin_types_compatible_p(type, long long) \|\| \
	53	__builtin_types_compatible_p(type, unsigned long long))
	54	#endif
	55
	56	/**
	57	* lttng_ust_ctf_array_element_type_is_supported -
	58	*
	59	* Adds a compilation assertion that CTF arrays and sequences declared by the
	60	* user are of an integral type.
	61	*/
	62	#define lttng_ust_ctf_array_element_type_is_supported(type, item) \
	63	lttng_static_assert(lttng_ust_is_integer_type(type), \
	64	"Non-integer type `" #item "` not supported as element of CTF_ARRAY or CTF_SEQUENCE", \
65	Non_integer_type__##item##__not_supported_as_element_of_CTF_ARRAY_or_CTF_SEQUENCE);
66
67
68	/**
69	* lttng_ust_runtime_bug_on - check condition at runtime
70	* @condition: the condition which should be false.
71	*
72	* If the condition is true, a BUG will be triggered at runtime.
73	*/
74	#define lttng_ust_runtime_bug_on(condition) \
75	do { \
76	if (caa_unlikely(condition)) { \
77	fprintf(stderr, \
78	"LTTng BUG in file %s, line %d.\n", \
79	__FILE__, __LINE__); \
80	exit(EXIT_FAILURE); \
81	} \
82	} while (0)
83
84
85	/**
86	* lttng_ust_build_bug_on - check condition at build
87	* @condition: the condition which should be false.
88	*
89	* If the condition is true, the compiler will generate a build error.
90	*/
91	#define lttng_ust_build_bug_on(condition) \
92	((void) sizeof(char[-!!(condition)]))
93
94
95	/**
96	* lttng_ust_build_runtime_bug_on - check condition at build (if constant) or runtime
97	* @condition: the condition which should be false.
98	*
99	* If the condition is a constant and true, the compiler will generate a build
100	* error. If the condition is not constant, a BUG will be triggered at runtime
101	* if the condition is ever true. If the condition is constant and false, no
102	* code is emitted.
103	*/
104	#define lttng_ust_build_runtime_bug_on(condition) \
105	do { \
106	if (__builtin_constant_p(condition)) \
107	lttng_ust_build_bug_on(condition); \
108	else \
109	lttng_ust_runtime_bug_on(condition); \
110	} while (0)
111
112
113	/**
114	* lttng_ust_offset_align - Calculate the offset needed to align an object on
115	* its natural alignment towards higher addresses.
116	* @align_drift: object offset from an "alignment"-aligned address.
117	* @alignment: natural object alignment. Must be non-zero, power of 2.
118	*
119	* Returns the offset that must be added to align towards higher
120	* addresses.
121	*/
122	#define lttng_ust_offset_align(align_drift, alignment) \
123	({ \
124	lttng_ust_build_runtime_bug_on((alignment) == 0 \
125	\|\| ((alignment) & ((alignment) - 1))); \
126	(((alignment) - (align_drift)) & ((alignment) - 1)); \
127	})
128
129
130	/**
131	* lttng_ust_offset_align_floor - Calculate the offset needed to align an
132	* object on its natural alignment towards lower addresses.
133	* @align_drift: object offset from an "alignment"-aligned address.
134	* @alignment: natural object alignment. Must be non-zero, power of 2.
135	*
136	* Returns the offset that must be substracted to align towards lower addresses.
137	*/
138	#define lttng_ust_offset_align_floor(align_drift, alignment) \
139	({ \
140	lttng_ust_build_runtime_bug_on((alignment) == 0 \
141	\|\| ((alignment) & ((alignment) - 1))); \
142	(((align_drift) - (alignment)) & ((alignment) - 1)); \
143	})
144
145	#endif /* _LTTNG_UST_UTILS_H */