| adamdunkels | d2eb552 | 2005-02-22 22:36:51 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2004-2005, Swedish Institute of Computer Science. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. Neither the name of the Institute nor the names of its contributors |
| 14 | * may be used to endorse or promote products derived from this software |
| 15 | * without specific prior written permission. |
| 16 | * |
| 17 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND |
| 18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE |
| 21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 27 | * SUCH DAMAGE. |
| 28 | * |
| 29 | * This file is part of the Contiki operating system. |
| 30 | * |
| 31 | * Author: Adam Dunkels <adam@sics.se> |
| 32 | * |
| 33 | * $Id: lc-addrlabels.h,v 1.1 2005/02/22 22:36:51 adamdunkels Exp $ |
| 34 | */ |
| 35 | |
| 36 | /** |
| 37 | * \addtogroup lc |
| 38 | * @{ |
| 39 | */ |
| 40 | |
| 41 | /** |
| 42 | * \file |
| 43 | * Implementation of local continuations based on the "Labels as |
| 44 | * values" feature of gcc |
| 45 | * \author |
| 46 | * Adam Dunkels <adam@sics.se> |
| 47 | * |
| 48 | * This implementation of local continuations is based on a special |
| 49 | * feature of the GCC C compiler called "labels as values". This |
| 50 | * feature allows assigning pointers with the address of the code |
| 51 | * corresponding to a particular C label. |
| 52 | * |
| 53 | * For more information, see the GCC documentation: |
| 54 | * http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html |
| 55 | * |
| 56 | */ |
| 57 | |
| 58 | #ifndef __LC_ADDRLABELS_H__ |
| 59 | #define __LC_ADDRLABELS_H__ |
| 60 | |
| 61 | /** \hideinitializer */ |
| 62 | typedef void * lc_t; |
| 63 | |
| 64 | #define LC_CONCAT2(s1, s2) s1##s2 |
| 65 | #define LC_CONCAT(s1, s2) LC_CONCAT2(s1, s2) |
| 66 | |
| 67 | #define LC_SET(s) \ |
| 68 | do { \ |
| 69 | LC_CONCAT(LC_LABEL, __LINE__): \ |
| 70 | (s) = &&LC_CONCAT(LC_LABEL, __LINE__); \ |
| 71 | } while(0) |
| 72 | |
| 73 | #define LC_RESUME(s) \ |
| 74 | do { \ |
| 75 | if(s != NULL) { \ |
| 76 | goto *s; \ |
| 77 | } \ |
| 78 | } while(0) |
| 79 | |
| 80 | #define LC_END(s) |
| 81 | |
| 82 | #define LC_INIT(s) s = NULL |
| 83 | |
| 84 | #endif /* __LC_ADDRLABELS_H__ */ |