1/*
2 * Copyright (c) 1990 Regents of the University of California.
3 * All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8
9/*
10
11@deftypefun int xatexit (void (*@var{fn}) (void))
12
13Behaves as the standard @code{atexit} function, but with no limit on
14the number of registered functions.  Returns 0 on success, or @minus{}1 on
15failure.  If you use @code{xatexit} to register functions, you must use
16@code{xexit} to terminate your program.
17
18@end deftypefun
19
20*/
21
22/* Adapted from newlib/libc/stdlib/{,at}exit.[ch].
23   If you use xatexit, you must call xexit instead of exit.  */
24
25#ifdef HAVE_CONFIG_H
26#include "config.h"
27#endif
28#include "ansidecl.h"
29#include "libiberty.h"
30
31#include <stdio.h>
32
33#include <stddef.h>
34
35#if VMS
36#include <stdlib.h>
37#include <unixlib.h>
38#else
39/* For systems with larger pointers than ints, this must be declared.  */
40PTR malloc (size_t);
41#endif
42
43static void xatexit_cleanup (void);
44
45/* Pointer to function run by xexit.  */
46extern void (*_xexit_cleanup) (void);
47
48#define	XATEXIT_SIZE 32
49
50struct xatexit {
51	struct	xatexit *next;		/* next in list */
52	int	ind;			/* next index in this table */
53	void	(*fns[XATEXIT_SIZE]) (void);	/* the table itself */
54};
55
56/* Allocate one struct statically to guarantee that we can register
57   at least a few handlers.  */
58static struct xatexit xatexit_first;
59
60/* Points to head of LIFO stack.  */
61static struct xatexit *xatexit_head = &xatexit_first;
62
63/* Register function FN to be run by xexit.
64   Return 0 if successful, -1 if not.  */
65
66int
67xatexit (void (*fn) (void))
68{
69  register struct xatexit *p;
70
71  /* Tell xexit to call xatexit_cleanup.  */
72  if (!_xexit_cleanup)
73    _xexit_cleanup = xatexit_cleanup;
74
75  p = xatexit_head;
76  if (p->ind >= XATEXIT_SIZE)
77    {
78      if ((p = (struct xatexit *) malloc (sizeof *p)) == NULL)
79	return -1;
80      p->ind = 0;
81      p->next = xatexit_head;
82      xatexit_head = p;
83    }
84  p->fns[p->ind++] = fn;
85  return 0;
86}
87
88/* Call any cleanup functions.  */
89
90static void
91xatexit_cleanup (void)
92{
93  register struct xatexit *p;
94  register int n;
95
96  for (p = xatexit_head; p; p = p->next)
97    for (n = p->ind; --n >= 0;)
98      (*p->fns[n]) ();
99}
100