include/set-hooks.h

   1 /* Macros for using symbol sets for running lists of functions.
   2    Copyright (C) 1994, 1995, 1997 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 not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef _SET_HOOKS_H
  21 #define _SET_HOOKS_H 1
  22
  23 #define __need_size_t
  24 #include <stddef.h>
  25 #include <sys/cdefs.h>
  26
  27 /* Define a hook variable called NAME.  Functions put on this hook take
  28    arguments described by PROTO.  Use `text_set_element (NAME, FUNCTION)'
  29    from gnu-stabs.h to add a function to the hook.  */
  30
  31 #define DEFINE_HOOK(NAME, PROTO)                \
  32   typedef void __##NAME##_hook_function_t PROTO; \
  33   symbol_set_define (NAME)
  34
  35 #define DECLARE_HOOK(NAME, PROTO)               \
  36   typedef void __##NAME##_hook_function_t PROTO;\
  37   symbol_set_declare (NAME)
  38
  39 /* Run all the functions hooked on the set called NAME.
  40    Each function is called like this: `function ARGS'.  */
  41
  42 #define RUN_HOOK(NAME, ARGS) \
  43 do {                                                                          \
  44   void *const *ptr;                                                           \
  45   for (ptr = symbol_set_first_element (NAME);                                 \
  46        ! symbol_set_end_p (NAME, ptr); ++ptr)                                 \
  47     (*(__##NAME##_hook_function_t *) *ptr) ARGS;                              \
  48 } while (0)
  49
  50 /* Define a hook variable with NAME and PROTO, and a function called RUNNER
  51    which calls each function on the hook in turn, with ARGS.  */
  52
  53 #define DEFINE_HOOK_RUNNER(name, runner, proto, args) \
  54 DEFINE_HOOK (name, proto); void runner proto { RUN_HOOK (name, args); }
  55
  56
  57 #endif /* set-hooks.h */