xref: /freebsd/lib/csu/common/crtbegin.c (revision 11afcc8f9f96d657b8e6f7547c02c1957331fc96)
1 /*-
2  * Copyright 1996-1998 John D. Polstra.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  *      $Id: crtbegin.c,v 1.3 1996/04/12 02:24:35 jdp Exp $
26  */
27 
28 typedef void (*fptr)(void);
29 
30 static fptr ctor_list[1] __attribute__((section(".ctors"))) = { (fptr) -1 };
31 static fptr dtor_list[1] __attribute__((section(".dtors"))) = { (fptr) -1 };
32 
33 static void
34 do_ctors(void)
35 {
36     fptr *fpp;
37 
38     for(fpp = ctor_list + 1;  *fpp != 0;  ++fpp)
39 	(**fpp)();
40 }
41 
42 static void
43 do_dtors(void)
44 {
45     fptr *fpp;
46 
47     for(fpp = dtor_list + 1;  *fpp != 0;  ++fpp)
48 	;
49     while(--fpp > dtor_list)
50 	(**fpp)();
51 }
52 
53 static void
54 function_skeleton(void)
55 {
56     __asm__(".section .init,\"ax\",@progbits");
57     do_ctors();
58     __asm__(".section .fini,\"ax\",@progbits");
59     do_dtors();
60     __asm__(".text");
61 }
62