xref: /openbsd-src/lib/csu/crtbegin.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: crtbegin.c,v 1.5 2001/02/03 23:11:23 art Exp $	*/
2 /*	$NetBSD: crtbegin.c,v 1.1 1996/09/12 16:59:03 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1993 Paul Kranenburg
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Paul Kranenburg.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Run-time module for GNU C++ compiled shared libraries.
36  *
37  * The linker constructs the following arrays of pointers to global
38  * constructors and destructors. The first element contains the
39  * number of pointers in each.
40  * The tables are also null-terminated.
41  */
42 #include <stdlib.h>
43 
44 #include "os-note-elf.h"
45 
46 static void (*__CTOR_LIST__[1]) __P((void))
47     __attribute__((section(".ctors"))) = { (void *)-1 };	/* XXX */
48 static void (*__DTOR_LIST__[1]) __P((void))
49     __attribute__((section(".dtors"))) = { (void *)-1 };	/* XXX */
50 
51 static void	__dtors __P((void));
52 static void	__ctors __P((void));
53 
54 static void
55 __dtors()
56 {
57 	unsigned long i = (unsigned long) __DTOR_LIST__[0];
58 	void (**p)(void);
59 
60 	if (i == -1)  {
61 		for (i = 1; __DTOR_LIST__[i] != NULL; i++)
62 			;
63 		i--;
64 	}
65 	p = __DTOR_LIST__ + i;
66 	while (i--)
67 		(**p--)();
68 }
69 
70 static void
71 __ctors()
72 {
73 	void (**p)(void) = __CTOR_LIST__ + 1;
74 
75 	while (*p)
76 		(**p++)();
77 }
78 
79 void __init(void) __attribute__((section(".init")));
80 void __fini(void) __attribute__((section(".fini")));
81 
82 void
83 __init()
84 {
85 	static int initialized = 0;
86 
87 	/*
88 	 * Call global constructors.
89 	 * Arrange to call global destructors at exit.
90 	 */
91 	if (!initialized) {
92 		initialized = 1;
93 		__ctors();
94 	}
95 
96 	atexit(__fini);
97 }
98 
99 void
100 __fini()
101 {
102 	/*
103 	 * Call global destructors.
104 	 */
105 	__dtors();
106 }
107 
108