gcc/config/m68k/aux-exit.c

   1 /* Generic atexit()
   2    Copyright (C) 1996 Free Software Foundation, Inc.
   3
   4 This file is free software; you can redistribute it and/or modify it
   5 under the terms of the GNU General Public License as published by the
   6 Free Software Foundation; either version 2, or (at your option) any
   7 later version.
   8
   9 In addition to the permissions in the GNU General Public License, the
  10 Free Software Foundation gives you unlimited permission to link the
  11 compiled version of this file into combinations with other programs,
  12 and to distribute those combinations without any restriction coming
  13 from the use of this file.  (The General Public License restrictions
  14 do apply in other respects; for example, they cover modification of
  15 the file, and distribution when not linked into a combine
  16 executable.)
  17
  18 This file is distributed in the hope that it will be useful, but
  19 WITHOUT ANY WARRANTY; without even the implied warranty of
  20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21 General Public License for more details.
  22
  23 You should have received a copy of the GNU General Public License
  24 along with this program; see the file COPYING.  If not, write to
  25 the Free Software Foundation, 59 Temple Place - Suite 330,
  26 Boston, MA 02111-1307, USA.  */
  27
  28 /* Rather than come up with some ugly hack to make mcrt1 work, it is
  29    better to just go ahead and provide atexit().  */
  30
  31
  32 #include <stdlib.h>
  33
  34
  35 void exit(int) __attribute__((noreturn));
  36 void _exit(int) __attribute__((noreturn));
  37 void _cleanup(void);
  38
  39
  40 #define FNS_PER_BLOCK   32
  41
  42 struct atexit_fn_block
  43 {
  44   struct atexit_fn_block *next;
  45   void (*fns[FNS_PER_BLOCK])(void);
  46   short used;
  47 };
  48
  49
  50 /* statically allocate the first block */
  51 static struct atexit_fn_block atexit_fns;
  52 static struct atexit_fn_block *current_block = &atexit_fns;
  53
  54
  55 int atexit(void (*fn)(void))
  56 {
  57   if (current_block->used >= FNS_PER_BLOCK)
  58     {
  59       struct atexit_fn_block *new_block =
  60         (struct atexit_fn_block *)malloc(sizeof(struct atexit_fn_block));
  61       if (new_block == NULL)
  62         return -1;
  63
  64       new_block->used = 0;
  65       new_block->next = current_block;
  66       current_block = new_block;
  67     }
  68
  69   current_block->fns[current_block->used++] = fn;
  70
  71   return 0;
  72 }
  73
  74
  75 void exit(int status)
  76 {
  77   struct atexit_fn_block *block = current_block, *old_block;
  78   short i;
  79
  80   while (1)
  81     {
  82       for (i = block->used; --i >= 0 ;)
  83         (*block->fns[i])();
  84       if (block == &atexit_fns)
  85         break;
  86       /* I know what you are thinking -- we are about to exit, why free?
  87          Because it is friendly to memory leak detectors, that's why. */
  88       old_block = block;
  89       block = block->next;
  90       free(old_block);
  91     }
  92
  93   _exit(status);
  94 }