/*
 * The Rin Library – special definitions
 *
 * Copyright (C) 2015-2019 Gediminas Jakutis
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; version 2.1
 * of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#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 */