set-hooks.h

   1 /* Macros for using symbol sets for running lists of functions.
   2 Copyright (C) 1994, 1995 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 The GNU C Library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #ifndef _SET_HOOKS_H
  21
  22 #define __need_size_t
  23 #include <stddef.h>
  24 #include <sys/cdefs.h>
  25
  26 /* Define a hook variable called NAME.  Functions put on this hook take
  27    arguments described by PROTO.  Use `text_set_element (NAME, FUNCTION)'
  28    from gnu-stabs.h to add a function to the hook.  */
  29
  30 #define DEFINE_HOOK(NAME, PROTO)                \
  31   typedef void __##NAME##_hook_function_t PROTO; \
  32   symbol_set_define (NAME)
  33
  34 #define DECLARE_HOOK(NAME, PROTO)               \
  35   typedef void __##NAME##_hook_function_t PROTO;\
  36   symbol_set_declare (NAME)
  37
  38 /* Run all the functions hooked on the set called NAME.
  39    Each function is called like this: `function ARGS'.  */
  40
  41 #define RUN_HOOK(NAME, ARGS) \
  42 do {                                                                          \
  43   void *const *ptr;                                                           \
  44   for (ptr = symbol_set_first_element (NAME);                                 \
  45        ! symbol_set_end_p (NAME, ptr); ++ptr)                                 \
  46     (*(__##NAME##_hook_function_t *) *ptr) ARGS;                              \
  47 } while (0)
  48
  49 /* Define a hook variable with NAME and PROTO, and a function called RUNNER
  50    which calls each function on the hook in turn, with ARGS.  */
  51
  52 #define DEFINE_HOOK_RUNNER(name, runner, proto, args) \
  53 DEFINE_HOOK (name, proto); void runner proto { RUN_HOOK (name, args); }
  54
  55
  56 #endif