/* SPDX-License-Identifier: LGPL-2.1-only */

/*
 * The Rin Library – special definitions
 *
 * Copyright (C) 2015-2021 Gediminas Jakutis
 */

#ifndef LIBRIN_DEFINITIONS_INCLUDED
#define LIBRIN_DEFINITIONS_INCLUDED

/* gcc */
#ifdef __GNUC__

/* weak symbols */
#	define WEAK_SYM __attribute__((weak))

/* allow the compiler to check varargs */
#	define FORMAT_STRING(a, b)  __attribute__((format (gnu_printf, a, b)))

/* optimizing likely / unlikely branches */
#	define likely(a) (__builtin_expect(!!(a), 1))
#	define unlikely(a) (__builtin_expect(!!(a), 0))

/* MSVC */
#elif defined(_MSC_VER)

/* weak symbols */
#	define WEAK_SYM __declspec(selectany)

#	define FORMAT_STRING(a, b)

/* optimizing likely / unlikely branches */
#	define likely(a) (a)
#	define unlikely(a) (a)

/* the rest – NOOP */
#else
#	define WEAK_SYM
#	define FORMAT_STRING(a, b)
#	define likely(a) (a)
#	define unlikely(a) (a)
#endif

#define rin_once(func) \
do { \
	static unsigned int __rin_firstrun = 1; \
	if (__rin_firstrun) { \
		--__rin_firstrun; \
		func; \
	} \
} while (0)

/* CLOCK_MONOTONIC is prefered when available, as
 * it does not suffer from discontinous jumps.
 * Otherwise use CLOCK_REALTIME as fallback.
 */
#if defined CLOCK_MONOTONIC
#	define RIN_CLOCK_WALL_COUNTER CLOCK_MONOTONIC
#else
#	define RIN_CLOCK_WALL_COUNTER CLOCK_REALTIME
#endif /* defined CLOCK_MONOTONIC */

#endif /* LIBRIN_DEFINITIONS_INCLUDED */