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[binutils.git] / libiberty / xatexit.c
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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 #include "ansidecl.h"
26 #include "libiberty.h"
28 #include <stdio.h>
30 #ifdef ANSI_PROTOTYPES
31 #include <stddef.h>
32 #else
33 #define size_t unsigned long
34 #endif
36 #if VMS
37 #include <stdlib.h>
38 #include <unixlib.h>
39 #else
40 /* For systems with larger pointers than ints, this must be declared. */
41 PTR malloc PARAMS ((size_t));
42 #endif
44 static void xatexit_cleanup PARAMS ((void));
46 /* Pointer to function run by xexit. */
47 extern void (*_xexit_cleanup) PARAMS ((void));
49 #define XATEXIT_SIZE 32
51 struct xatexit {
52 struct xatexit *next; /* next in list */
53 int ind; /* next index in this table */
54 void (*fns[XATEXIT_SIZE]) PARAMS ((void)); /* the table itself */
57 /* Allocate one struct statically to guarantee that we can register
58 at least a few handlers. */
59 static struct xatexit xatexit_first;
61 /* Points to head of LIFO stack. */
62 static struct xatexit *xatexit_head = &xatexit_first;
64 /* Register function FN to be run by xexit.
65 Return 0 if successful, -1 if not. */
67 int
68 xatexit (fn)
69 void (*fn) PARAMS ((void));
71 register struct xatexit *p;
73 /* Tell xexit to call xatexit_cleanup. */
74 if (!_xexit_cleanup)
75 _xexit_cleanup = xatexit_cleanup;
77 p = xatexit_head;
78 if (p->ind >= XATEXIT_SIZE)
80 if ((p = (struct xatexit *) malloc (sizeof *p)) == NULL)
81 return -1;
82 p->ind = 0;
83 p->next = xatexit_head;
84 xatexit_head = p;
86 p->fns[p->ind++] = fn;
87 return 0;
90 /* Call any cleanup functions. */
92 static void
93 xatexit_cleanup ()
95 register struct xatexit *p;
96 register int n;
98 for (p = xatexit_head; p; p = p->next)
99 for (n = p->ind; --n >= 0;)
100 (*p->fns[n]) ();