include/set-hooks.h

   1 /* Macros for using symbol sets for running lists of functions.
   2    Copyright (C) 1994, 1995, 1997, 2000 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    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 #ifdef symbol_set_define
  28 /* Define a hook variable called NAME.  Functions put on this hook take
  29    arguments described by PROTO.  Use `text_set_element (NAME, FUNCTION)'
  30    from gnu-stabs.h to add a function to the hook.  */
  31
  32 # define DEFINE_HOOK(NAME, PROTO)               \
  33   typedef void __##NAME##_hook_function_t PROTO; \
  34   symbol_set_define (NAME)
  35
  36 # define DECLARE_HOOK(NAME, PROTO)              \
  37   typedef void __##NAME##_hook_function_t PROTO;\
  38   symbol_set_declare (NAME)
  39
  40 /* Run all the functions hooked on the set called NAME.
  41    Each function is called like this: `function ARGS'.  */
  42
  43 # define RUN_HOOK(NAME, ARGS)                           \
  44 do {                                                    \
  45   void *const *__unbounded ptr;                         \
  46   for (ptr = symbol_set_first_element (NAME);           \
  47        ! symbol_set_end_p (NAME, ptr); ++ptr)           \
  48     (*(__##NAME##_hook_function_t *) *ptr) ARGS;        \
  49 } while (0)
  50
  51 /* Define a hook variable with NAME and PROTO, and a function called RUNNER
  52    which calls each function on the hook in turn, with ARGS.  */
  53
  54 # define DEFINE_HOOK_RUNNER(name, runner, proto, args) \
  55 DEFINE_HOOK (name, proto); \
  56 extern void runner proto; void runner proto { RUN_HOOK (name, args); }
  57
  58 #else
  59
  60 /* The system does not provide necessary support for this.  */
  61 # define DEFINE_HOOK(NAME, PROTO)
  62
  63 # define DECLARE_HOOK(NAME, PROTO)
  64
  65 # define RUN_HOOK(NAME, ARGS)
  66
  67 # define DEFINE_HOOK_RUNNER(name, runner, proto, args)
  68
  69 #endif
  70
  71 #endif /* set-hooks.h */