/*
 * Copyright (c) 2009-2015 Richard Braun.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Helper macros.
 *
 * Upstream site with license notes :
 * http://git.sceen.net/rbraun/librbraun.git/
 */

#ifndef _MACROS_H
#define _MACROS_H

#if !defined(__GNUC__) || (__GNUC__ < 4)
#error "GCC 4+ required"
#endif

#include <stddef.h>

#define MACRO_BEGIN         ({
#define MACRO_END           })

#define __QUOTE(x)          #x
#define QUOTE(x)            __QUOTE(x)

#define STRLEN(x)           (sizeof(x) - 1)
#define ARRAY_SIZE(x)       (sizeof(x) / sizeof((x)[0]))

#define MIN(a, b)           ((a) < (b) ? (a) : (b))
#define MAX(a, b)           ((a) > (b) ? (a) : (b))

#define DIV_CEIL(n, d)      (((n) + (d) - 1) / (d))

#define P2ALIGNED(x, a)     (((x) & ((a) - 1)) == 0)
#define ISP2(x)             P2ALIGNED(x, x)
#define P2ALIGN(x, a)       ((x) & -(a))
#define P2ROUND(x, a)       (-(-(x) & -(a)))
#define P2END(x, a)         (-(~(x) & -(a)))

#define structof(ptr, type, member) \
    ((type *)((char *)(ptr) - offsetof(type, member)))

#define access_once(x)      (*(volatile typeof(x) *)&(x))

#define alignof(x)          __alignof__(x)

#define likely(expr)        __builtin_expect(!!(expr), 1)
#define unlikely(expr)      __builtin_expect(!!(expr), 0)

#define barrier()           asm volatile("" : : : "memory")

#define __noreturn          __attribute__((noreturn))
#define __alias(x)          __attribute__((alias(x)))

#define __format_printf(fmt, args) \
    __attribute__((format(printf, fmt, args)))

/*
 * The following macros may be provided by the C environment.
 */

#ifndef __aligned
#define __aligned(x)        __attribute__((aligned(x)))
#endif

#ifndef __always_inline
#define __always_inline     inline __attribute__((always_inline))
#endif

#ifndef __section
#define __section(x)        __attribute__((section(x)))
#endif

#ifndef __packed
#define __packed            __attribute__((packed))
#endif

#endif /* _MACROS_H */