compiler.h

/*
 * Copyright (C) 2013 Philippe Gerum <rpm@xenomai.org>.
 *
 * 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; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#ifndef _BOILERPLATE_COMPILER_H
#define _BOILERPLATE_COMPILER_H
 
#include <stddef.h>
 
#define container_of(ptr, type, member)                                 \
        ({                                                              \
                const __typeof__(((type *)0)->member) *__mptr = (ptr);  \
                (type *)((char *)__mptr - offsetof(type, member));      \
        })
 
#define __stringify_1(x...)     #x
#define __stringify(x...)       __stringify_1(x)
 
#ifndef __noreturn
#define __noreturn      __attribute__((__noreturn__))
#endif
 
#ifndef __must_check
#define __must_check    __attribute__((__warn_unused_result__))
#endif
 
#ifndef __weak
#define __weak          __attribute__((__weak__))
#endif
 
#ifndef __maybe_unused
#define __maybe_unused  __attribute__((__unused__))
#endif
 
#ifndef __aligned
#define __aligned(__n)  __attribute__((aligned (__n)))
#endif
 
#ifndef __deprecated
#define __deprecated    __attribute__((__deprecated__))
#endif
 
#ifndef __packed
#define __packed        __attribute__((__packed__))
#endif
 
#ifndef __alloc_size
#define __alloc_size(__args)    __attribute__((__alloc_size__(__args)))
#endif
 
#define __align_to(__size, __al)  (((__size) + (__al) - 1) & (~((__al) - 1)))
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define xenomai_count_trailing_zeros(x)                                 \
        ((x) == 0 ? (int)(sizeof(x) * __CHAR_BIT__)                     \
        : sizeof(x) <= sizeof(unsigned int) ?                           \
                __builtin_ctz((unsigned int)x)                          \
        : sizeof(x) <= sizeof(unsigned long) ?                          \
                __builtin_ctzl((unsigned long)x)                        \
        : __builtin_ctzll(x))
 
#define xenomai_count_leading_zeros(x)                                  \
        ((x) == 0 ? (int)(sizeof(x) * __CHAR_BIT__)                     \
        : sizeof(x) <= sizeof(unsigned int) ?                           \
                __builtin_clz((unsigned int)x) +                        \
                        (int)(sizeof(unsigned int) - sizeof(x))         \
        : sizeof(x) <= sizeof(unsigned long) ?                          \
                __builtin_clzl((unsigned long)x)                        \
        : __builtin_clzll(x))
 
#ifdef __cplusplus
}
#endif
 
#endif /* _BOILERPLATE_COMPILER_H */