/* * Copyright (c) 2004-2005, Swedish Institute of Computer Science. * 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. * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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. * * This file is part of the Contiki operating system. * * Author: Adam Dunkels <adam@sics.se> * * $Id: lc-addrlabels.h,v 1.1 2006/06/17 22:41:20 adamdunkels Exp $ */ /** * \addtogroup lc * @{ */ /** * \file * Implementation of local continuations based on the "Labels as * values" feature of gcc * \author * Adam Dunkels <adam@sics.se> * * This implementation of local continuations is based on a special * feature of the GCC C compiler called "labels as values". This * feature allows assigning pointers with the address of the code * corresponding to a particular C label. * * For more information, see the GCC documentation: * http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html * * Thanks to dividuum for finding the nice local scope label * implementation. */ #ifndef __LC_ADDRLABELS_H__ #define __LC_ADDRLABELS_H__ /** \hideinitializer */ typedef void * lc_t; #define LC_INIT(s) s = NULL #define LC_RESUME(s) \ do { \ if(s != NULL) { \ goto *s; \ } \ } while(0) #define LC_SET(s) \ do { ({ __label__ resume; resume: (s) = &&resume; }); }while(0) #define LC_END(s) #endif /* __LC_ADDRLABELS_H__ */ /** @} */