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

// SPDX-FileCopyrightText: 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
// SPDX-FileCopyrightText: 2011-2012 Paul Woegerer <paul_woegerer@mentor.com>
//
// SPDX-License-Identifier: MIT

#ifndef _LTTNG_UST_COMPILER_H
#define _LTTNG_UST_COMPILER_H

#include <assert.h>

/*
 * By default, LTTng-UST uses the priority 150 for the tracepoint and probe
 * provider constructors to trace tracepoints located within
 * constructors/destructors with a higher priority value within the same
 * module. This priority can be overridden by the application.
 */
#ifndef LTTNG_UST_CONSTRUCTOR_PRIO
#define LTTNG_UST_CONSTRUCTOR_PRIO	150
#endif

#define lttng_ust_notrace __attribute__((no_instrument_function))

/*
 * Clang supports the no_sanitize variable attribute on global variables.
 * GCC only supports the no_sanitize_address function attribute, which is
 * not what we need.
 */
#if defined(__clang__)
# if __has_feature(address_sanitizer)
#  define __lttng_ust_variable_attribute_no_sanitize_address \
	__attribute__((no_sanitize("address")))
# else
#  define __lttng_ust_variable_attribute_no_sanitize_address
# endif
#else
#  define __lttng_ust_variable_attribute_no_sanitize_address
#endif

/*
 * g++ 4.8 and prior do not support C99 compound literals. Therefore,
 * force allocating those on the heap with these C++ compilers.
 */
#if defined (__cplusplus) && !defined (__clang__) && defined (__GNUC__) && \
	((__GNUC__ < 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 8)))
# ifndef LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP
#  define LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP
# endif
#endif

/*
 * Compound literals with static storage are needed by LTTng.
 * Compound literals are part of the C99 and C11 standards, but not
 * part of the C++ standards. However, those are supported by both g++ and
 * clang. In order to be strictly C++11 compliant, defining
 * LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP before including this header
 * allocates those on the heap in C++.
 *
 * Example use:
 * static struct mystruct *var = LTTNG_UST_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 });
 */
#if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP)
#define LTTNG_UST_COMPOUND_LITERAL(type, ...)	new (type) __VA_ARGS__
#else
#define LTTNG_UST_COMPOUND_LITERAL(type, ...)	(type[]) { __VA_ARGS__ }
#endif

/*
 * Compile time assertion.
 * - predicate: boolean expression to evaluate,
 * - msg: string to print to the user on failure when `static_assert()` is
 *   supported,
 * - c_identifier_msg: message to be included in the typedef to emulate a
 *   static assertion. This parameter must be a valid C identifier as it will
 *   be used as a typedef name.
 */
#ifdef __cplusplus
#define lttng_ust_static_assert(predicate, msg, c_identifier_msg)  \
	static_assert(predicate, msg)
#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
#define lttng_ust_static_assert(predicate, msg, c_identifier_msg)  \
	_Static_assert(predicate, msg)
#else
/*
 * Evaluates the predicate and emit a compilation error on failure.
 *
 * If the predicate evaluates to true, this macro emits a function
 * prototype with an argument type which is an array of size 0.
 *
 * If the predicate evaluates to false, this macro emits a function
 * prototype with an argument type which is an array of negative size
 * which is invalid in C and forces a compiler error. The
 * c_identifier_msg parameter is used as the argument identifier so it
 * is printed to the user when the error is reported.
 */
#define lttng_ust_static_assert(predicate, msg, c_identifier_msg)  \
	void lttng_ust_static_assert_proto(char c_identifier_msg[2*!!(predicate)-1])
#endif

/* Combine two tokens. */
#define LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb)			\
		_tokena##_tokenb
#define LTTNG_UST_COMPILER_COMBINE_TOKENS(_tokena, _tokenb)			\
		LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb)
/*
 * Wrap constructor and destructor functions to invoke them as functions with
 * the constructor/destructor GNU C attributes, which ensures that those
 * constructors/destructors are ordered before/after C++
 * constructors/destructors.
 *
 * Wrap constructor and destructor functions as the constructor/destructor of a
 * variable defined within an anonymous namespace when building as C++ with
 * LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP defined. With this option,
 * there are no guarantees that the events in C++ constructors/destructors will
 * be traced.
 */
#if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP)
#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func,	\
						 destructor_func, ...)		\
namespace lttng {								\
namespace ust {									\
namespace details {								\
class LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_,      \
				   name) {					\
public:										\
	LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \
	~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \
};										\
LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \
{										\
	constructor_func();							\
}										\
LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \
{										\
	destructor_func();							\
}										\
}										\
}										\
}										\
										\
namespace {									\
const lttng::ust::details::LTTNG_UST_COMPILER_COMBINE_TOKENS(			\
	lttng_ust_constructor_destructor_, name)				\
		LTTNG_UST_COMPILER_COMBINE_TOKENS(name, registration_instance); \
}
#else
#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func,	\
						 destructor_func, ...)		\
	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \
		__attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \
	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \
	{									\
		constructor_func();						\
	}									\
	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \
		__attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \
	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \
	{									\
		destructor_func();						\
	}
#endif

#endif /* _LTTNG_UST_COMPILER_H */
Commit	Line	Data
1c196845 MJ	1	// SPDX-FileCopyrightText: 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	2	// SPDX-FileCopyrightText: 2011-2012 Paul Woegerer <paul_woegerer@mentor.com>
	3	//
	4	// SPDX-License-Identifier: MIT
a8909ba5	5
c0c0989a MJ	6	#ifndef _LTTNG_UST_COMPILER_H
	7	#define _LTTNG_UST_COMPILER_H
	8
7f264068 FD	9	#include <assert.h>
7f264068 FD	10
63661b66 MD	11	/*
	12	* By default, LTTng-UST uses the priority 150 for the tracepoint and probe
	13	* provider constructors to trace tracepoints located within
	14	* constructors/destructors with a higher priority value within the same
	15	* module. This priority can be overridden by the application.
	16	*/
	17	#ifndef LTTNG_UST_CONSTRUCTOR_PRIO
	18	#define LTTNG_UST_CONSTRUCTOR_PRIO 150
	19	#endif
	20
a8909ba5 PW	21	#define lttng_ust_notrace __attribute__((no_instrument_function))
a8909ba5 PW	22
4f74bc5e MD	23	/*
	24	* Clang supports the no_sanitize variable attribute on global variables.
	25	* GCC only supports the no_sanitize_address function attribute, which is
	26	* not what we need.
	27	*/
	28	#if defined(__clang__)
	29	# if __has_feature(address_sanitizer)
	30	# define __lttng_ust_variable_attribute_no_sanitize_address \
	31	__attribute__((no_sanitize("address")))
	32	# else
	33	# define __lttng_ust_variable_attribute_no_sanitize_address
	34	# endif
	35	#else
	36	# define __lttng_ust_variable_attribute_no_sanitize_address
	37	#endif
	38
e1904921 MD	39	/*
	40	* g++ 4.8 and prior do not support C99 compound literals. Therefore,
	41	* force allocating those on the heap with these C++ compilers.
	42	*/
7850c5cc MJ	43	#if defined (__cplusplus) && !defined (__clang__) && defined (__GNUC__) && \
7850c5cc MJ	44	((__GNUC__ < 4) \|\| ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 8)))
439f90cf MD	45	# ifndef LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP
439f90cf MD	46	# define LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP
e1904921 MD	47	# endif
	48	#endif
	49
7edfc172 MD	50	/*
	51	* Compound literals with static storage are needed by LTTng.
	52	* Compound literals are part of the C99 and C11 standards, but not
	53	* part of the C++ standards. However, those are supported by both g++ and
	54	* clang. In order to be strictly C++11 compliant, defining
439f90cf	55	* LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP before including this header
7edfc172 MD	56	* allocates those on the heap in C++.
	57	*
	58	* Example use:
5defa774	59	* static struct mystruct *var = LTTNG_UST_COMPOUND_LITERAL(struct mystruct, { 1, 2, 3 });
7edfc172	60	*/
439f90cf	61	#if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP)
5defa774	62	#define LTTNG_UST_COMPOUND_LITERAL(type, ...) new (type) __VA_ARGS__
7edfc172	63	#else
5defa774	64	#define LTTNG_UST_COMPOUND_LITERAL(type, ...) (type[]) { __VA_ARGS__ }
7edfc172 MD	65	#endif
7edfc172 MD	66
7f264068 FD	67	/*
	68	* Compile time assertion.
	69	* - predicate: boolean expression to evaluate,
	70	* - msg: string to print to the user on failure when `static_assert()` is
	71	* supported,
	72	* - c_identifier_msg: message to be included in the typedef to emulate a
	73	* static assertion. This parameter must be a valid C identifier as it will
	74	* be used as a typedef name.
	75	*/
89350fda	76	#ifdef __cplusplus
3a98c813	77	#define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \
7f264068	78	static_assert(predicate, msg)
3615ef97	79	#elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
89350fda MD	80	#define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \
89350fda MD	81	_Static_assert(predicate, msg)
7f264068 FD	82	#else
	83	/*
	84	* Evaluates the predicate and emit a compilation error on failure.
	85	*
4c3d9cd0 MD	86	* If the predicate evaluates to true, this macro emits a function
4c3d9cd0 MD	87	* prototype with an argument type which is an array of size 0.
7f264068	88	*
4c3d9cd0 MD	89	* If the predicate evaluates to false, this macro emits a function
	90	* prototype with an argument type which is an array of negative size
	91	* which is invalid in C and forces a compiler error. The
	92	* c_identifier_msg parameter is used as the argument identifier so it
	93	* is printed to the user when the error is reported.
7f264068	94	*/
3a98c813	95	#define lttng_ust_static_assert(predicate, msg, c_identifier_msg) \
4c3d9cd0	96	void lttng_ust_static_assert_proto(char c_identifier_msg[2*!!(predicate)-1])
7f264068 FD	97	#endif
7f264068 FD	98
08f6e282 MD	99	/* Combine two tokens. */
	100	#define LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb) \
	101	_tokena##_tokenb
	102	#define LTTNG_UST_COMPILER_COMBINE_TOKENS(_tokena, _tokenb) \
	103	LTTNG_UST_COMPILER__COMBINE_TOKENS(_tokena, _tokenb)
05bfa3dc JG	104	/*
05bfa3dc JG	105	* Wrap constructor and destructor functions to invoke them as functions with
0b5a6313 MD	106	* the constructor/destructor GNU C attributes, which ensures that those
	107	* constructors/destructors are ordered before/after C++
	108	* constructors/destructors.
	109	*
	110	* Wrap constructor and destructor functions as the constructor/destructor of a
	111	* variable defined within an anonymous namespace when building as C++ with
	112	* LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP defined. With this option,
	113	* there are no guarantees that the events in C++ constructors/destructors will
	114	* be traced.
05bfa3dc	115	*/
0b5a6313	116	#if defined (__cplusplus) && defined (LTTNG_UST_ALLOCATE_COMPOUND_LITERAL_ON_HEAP)
08f6e282 MD	117	#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \
	118	destructor_func, ...) \
	119	namespace lttng { \
	120	namespace ust { \
	121	namespace details { \
	122	class LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, \
	123	name) { \
	124	public: \
801389e7 MD	125	LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \
801389e7 MD	126	~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() __VA_ARGS__; \
08f6e282	127	}; \
801389e7 MD	128	LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \
	129	{ \
	130	constructor_func(); \
	131	} \
	132	LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)::~LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_destructor_, name)() \
	133	{ \
	134	destructor_func(); \
	135	} \
08f6e282 MD	136	} \
	137	} \
	138	} \
	139	\
	140	namespace { \
	141	const lttng::ust::details::LTTNG_UST_COMPILER_COMBINE_TOKENS( \
	142	lttng_ust_constructor_destructor_, name) \
	143	LTTNG_UST_COMPILER_COMBINE_TOKENS(name, registration_instance); \
05bfa3dc	144	}
0b5a6313	145	#else
08f6e282 MD	146	#define LTTNG_UST_DECLARE_CONSTRUCTOR_DESTRUCTOR(name, constructor_func, \
	147	destructor_func, ...) \
	148	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \
63661b66	149	__attribute__((constructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \
08f6e282 MD	150	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_constructor_, name)(void) \
	151	{ \
	152	constructor_func(); \
	153	} \
	154	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \
63661b66	155	__attribute__((destructor(LTTNG_UST_CONSTRUCTOR_PRIO))) __VA_ARGS__; \
08f6e282 MD	156	static void LTTNG_UST_COMPILER_COMBINE_TOKENS(lttng_ust_destructor_, name)(void) \
	157	{ \
	158	destructor_func(); \
05bfa3dc JG	159	}
	160	#endif
	161
a8909ba5	162	#endif /* _LTTNG_UST_COMPILER_H */