# lc-addrlabels.h

Go to the documentation of this file.

    00001 /*
    00002  * Copyright (c) 2004-2005, Swedish Institute of Computer Science.
    00003  * All rights reserved.
    00004  *
    00005  * Redistribution and use in source and binary forms, with or without
    00006  * modification, are permitted provided that the following conditions
    00007  * are met:
    00008  * 1. Redistributions of source code must retain the above copyright
    00009  *    notice, this list of conditions and the following disclaimer.
    00010  * 2. Redistributions in binary form must reproduce the above copyright
    00011  *    notice, this list of conditions and the following disclaimer in the
    00012  *    documentation and/or other materials provided with the distribution.
    00013  * 3. Neither the name of the Institute nor the names of its contributors
    00014  *    may be used to endorse or promote products derived from this software
    00015  *    without specific prior written permission.
    00016  *
    00017  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
    00018  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    00019  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    00020  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
    00021  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    00022  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    00023  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    00024  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    00025  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    00026  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    00027  * SUCH DAMAGE.
    00028  *
    00029  * This file is part of the Contiki operating system.
    00030  *
    00031  * Author: Adam Dunkels <adam@sics.se>
    00032  *
    00033  * $Id: lc-addrlabels.h,v 1.4 2006/06/03 11:29:43 adam Exp $
    00034  */
    00035
    00036 /**
    00037  * \addtogroup lc
    00038  * @{
    00039  */
    00040
    00041 /**
    00042  * \file
    00043  * Implementation of local continuations based on the "Labels as
    00044  * values" feature of gcc
    00045  * \author
    00046  * Adam Dunkels <adam@sics.se>
    00047  *
    00048  * This implementation of local continuations is based on a special
    00049  * feature of the GCC C compiler called "labels as values". This
    00050  * feature allows assigning pointers with the address of the code
    00051  * corresponding to a particular C label.
    00052  *
    00053  * For more information, see the GCC documentation:
    00054  * http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
    00055  *
    00056  */
    00057
    00058 #ifndef __LC_ADDRLABELS_H__
    00059 #define __LC_ADDRLABELS_H__
    00060
    00061 /** \hideinitializer */
    00062 typedef void * lc_t;
    00063
    00064 #define LC_INIT(s) s = NULL
    00065
    00066 #define LC_RESUME(s)                            \
    00067   do {                                          \
    00068     if(s != NULL) {                             \
    00069       goto *s;                                  \
    00070     }                                           \
    00071   } while(0)
    00072
    00073 #define LC_CONCAT2(s1, s2) s1##s2
    00074 #define LC_CONCAT(s1, s2) LC_CONCAT2(s1, s2)
    00075
    00076 #define LC_SET(s)                               \
    00077   do {                                          \
    00078     LC_CONCAT(LC_LABEL, __LINE__):              \
    00079     (s) = &&LC_CONCAT(LC_LABEL, __LINE__);      \
    00080   } while(0)
    00081
    00082 #define LC_END(s)
    00083
    00084 #endif /* __LC_ADDRLABELS_H__ */
    00085 /** @} */