2014-02-28 Janus Weil <janus@gcc.gnu.org>
[official-gcc.git] / libiberty / xatexit.c
blob6fdad9ed806a0a336f75c7869bb19a23bc6521d3
1 /*
2 * Copyright (c) 1990 Regents of the University of California.
3 * All rights reserved.
5 * %sccs.include.redist.c%
6 */
9 /*
11 @deftypefun int xatexit (void (*@var{fn}) (void))
13 Behaves as the standard @code{atexit} function, but with no limit on
14 the number of registered functions. Returns 0 on success, or @minus{}1 on
15 failure. If you use @code{xatexit} to register functions, you must use
16 @code{xexit} to terminate your program.
18 @end deftypefun
22 /* Adapted from newlib/libc/stdlib/{,at}exit.[ch].
23 If you use xatexit, you must call xexit instead of exit. */
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 #include "ansidecl.h"
29 #include "libiberty.h"
31 #include <stdio.h>
33 #include <stddef.h>
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. */
40 PTR malloc (size_t);
41 #endif
43 static void xatexit_cleanup (void);
45 /* Pointer to function run by xexit. */
46 extern void (*_xexit_cleanup) (void);
48 #define XATEXIT_SIZE 32
50 struct 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 */
56 /* Allocate one struct statically to guarantee that we can register
57 at least a few handlers. */
58 static struct xatexit xatexit_first;
60 /* Points to head of LIFO stack. */
61 static struct xatexit *xatexit_head = &xatexit_first;
63 /* Register function FN to be run by xexit.
64 Return 0 if successful, -1 if not. */
66 int
67 xatexit (void (*fn) (void))
69 register struct xatexit *p;
71 /* Tell xexit to call xatexit_cleanup. */
72 if (!_xexit_cleanup)
73 _xexit_cleanup = xatexit_cleanup;
75 p = xatexit_head;
76 if (p->ind >= XATEXIT_SIZE)
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;
84 p->fns[p->ind++] = fn;
85 return 0;
88 /* Call any cleanup functions. */
90 static void
91 xatexit_cleanup (void)
93 register struct xatexit *p;
94 register int n;
96 for (p = xatexit_head; p; p = p->next)
97 for (n = p->ind; --n >= 0;)
98 (*p->fns[n]) ();