lc-addrlabels.h 2.8 KB

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  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 1.4 2006/06/03 11:29:43 adam Exp $
  34. */
  35. /**
  36. * \addtogroup lc
  37. * @{
  38. */
  39. /**
  40. * \file
  41. * Implementation of local continuations based on the "Labels as
  42. * values" feature of gcc
  43. * \author
  44. * Adam Dunkels <adam@sics.se>
  45. *
  46. * This implementation of local continuations is based on a special
  47. * feature of the GCC C compiler called "labels as values". This
  48. * feature allows assigning pointers with the address of the code
  49. * corresponding to a particular C label.
  50. *
  51. * For more information, see the GCC documentation:
  52. * http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html
  53. *
  54. */
  55. #ifndef __LC_ADDRLABELS_H__
  56. #define __LC_ADDRLABELS_H__
  57. /** \hideinitializer */
  58. typedef void * lc_t;
  59. #define LC_INIT(s) s = NULL
  60. #define LC_RESUME(s) \
  61. do { \
  62. if(s != NULL) { \
  63. goto *s; \
  64. } \
  65. } while(0)
  66. #define LC_CONCAT2(s1, s2) s1##s2
  67. #define LC_CONCAT(s1, s2) LC_CONCAT2(s1, s2)
  68. #define LC_SET(s) \
  69. do { \
  70. LC_CONCAT(LC_LABEL, __LINE__): \
  71. (s) = &&LC_CONCAT(LC_LABEL, __LINE__); \
  72. } while(0)
  73. #define LC_END(s)
  74. #endif /* __LC_ADDRLABELS_H__ */
  75. /** @} */