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/*

 * Copyright (c) 1990 Regents of the University of California.

 * All rights reserved.

 *

 * %sccs.include.redist.c%

 */

/*

@deftypefun int xatexit (void (*@var{fn}) (void))

Behaves as the standard @code{atexit} function, but with no limit on

the number of registered functions.  Returns 0 on success, or @minus{}1 on

failure.  If you use @code{xatexit} to register functions, you must use

@code{xexit} to terminate your program.

@end deftypefun

*/

/* Adapted from newlib/libc/stdlib/{,at}exit.[ch].

   If you use xatexit, you must call xexit instead of exit.  */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "ansidecl.h"

#include "libiberty.h"

#include <stdio.h>

#include <stddef.h>

#if VMS

#include <stdlib.h>

#include <unixlib.h>

#else

/* For systems with larger pointers than ints, this must be declared.  */

PTR malloc (size_t);

#endif

static void xatexit_cleanup (void);

/* Pointer to function run by xexit.  */

extern void (*_xexit_cleanup) (void);

#define XATEXIT_SIZE 32

struct xatexit {

        struct  xatexit *next;          /* next in list */

        int     ind;                    /* next index in this table */

        void    (*fns[XATEXIT_SIZE]) (void);    /* the table itself */

};

/* Allocate one struct statically to guarantee that we can register

   at least a few handlers.  */

static struct xatexit xatexit_first;

/* Points to head of LIFO stack.  */

static struct xatexit *xatexit_head = &xatexit_first;

/* Register function FN to be run by xexit.

   Return 0 if successful, -1 if not.  */

int

xatexit (void (*fn) (void))

{

  register struct xatexit *p;

  /* Tell xexit to call xatexit_cleanup.  */

  if (!_xexit_cleanup)

    _xexit_cleanup = xatexit_cleanup;

  p = xatexit_head;

  if (p->ind >= XATEXIT_SIZE)

    {

      if ((p = (struct xatexit *) malloc (sizeof *p)) == NULL)

        return -1;

      p->ind = 0;

      p->next = xatexit_head;

      xatexit_head = p;

    }

  p->fns[p->ind++] = fn;

  return 0;

}

/* Call any cleanup functions.  */

static void

xatexit_cleanup (void)

{

  register struct xatexit *p;

  register int n;

  for (p = xatexit_head; p; p = p->next)

    for (n = p->ind; --n >= 0;)

      (*p->fns[n]) ();

}