xref: /freebsd/lib/csu/common/crtbegin.c (revision 1b6c2589164a3a7b2f62d4c28c2ffa1be860959e)
1 /*-
2  * Copyright 1996, 1997, 1998, 2000 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  * $FreeBSD$
26  */
27 
28 #include <sys/param.h>
29 
30 #define ABI_VENDOR	"FreeBSD"
31 #define ABI_SECTION	".note.ABI-tag"
32 #define ABI_NOTETYPE	1
33 
34 typedef void (*fptr)(void);
35 
36 static fptr ctor_list[1] __attribute__((section(".ctors"))) = { (fptr) -1 };
37 static fptr dtor_list[1] __attribute__((section(".dtors"))) = { (fptr) -1 };
38 
39 static void
40 do_ctors(void)
41 {
42     fptr *fpp;
43 
44     for(fpp = ctor_list + 1;  *fpp != 0;  ++fpp)
45 	;
46     while(--fpp > ctor_list)
47 	(**fpp)();
48 }
49 
50 static void
51 do_dtors(void)
52 {
53     fptr *fpp;
54 
55     for(fpp = dtor_list + 1;  *fpp != 0;  ++fpp)
56 	(**fpp)();
57 }
58 
59 /*
60  * With very large programs on some architectures (e.g., the Alpha),
61  * it is possible to get relocation overflows on the limited
62  * displacements of call/bsr instructions.  It is particularly likely
63  * for the calls from _init() and _fini(), because they are in
64  * separate sections.  Avoid the problem by forcing indirect calls.
65  */
66 static void (*p_do_ctors)(void) = do_ctors;
67 static void (*p_do_dtors)(void) = do_dtors;
68 
69 extern void _init(void) __attribute__((section(".init")));
70 
71 void
72 _init(void)
73 {
74 	(*p_do_ctors)();
75 }
76 
77 extern void _fini(void) __attribute__((section(".fini")));
78 
79 void
80 _fini(void)
81 {
82 	(*p_do_dtors)();
83 }
84 
85 #include "crtbrand.c"
86