xref: /freebsd/lib/csu/common/crtend.c (revision d34048812292b714a0bf99967270d18fe3097c62)
1 /*-
2  * SPDX-License-Identifier: BSD-1-Clause
3  *
4  * Copyright 2018 Andrew Turner
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  *
12  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
13  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
14  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
15  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
16  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
17  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
18  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
19  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
20  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
21  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22  */
23 
24 #include <sys/cdefs.h>
25 __FBSDID("$FreeBSD$");
26 
27 #include "crt.h"
28 
29 #ifdef HAVE_CTORS
30 typedef void (*crt_func)(void);
31 
32 /*
33  * On some architectures and toolchains we may need to call the .ctors.
34  * These are called in the reverse order they are in the ELF file.
35  */
36 static void __do_global_ctors_aux(void) __used;
37 
38 static crt_func __CTOR_END__[] __section(".ctors") __used = {
39 	(crt_func)0
40 };
41 static crt_func __DTOR_END__[] __section(".dtors") __used = {
42 	(crt_func)0
43 };
44 static crt_func __JCR_LIST__[] __section(".jcr") __used = {
45 	(crt_func)0
46 };
47 
48 static void
49 __do_global_ctors_aux(void)
50 {
51 	crt_func fn;
52 	int n;
53 
54 	for (n = 1;; n++) {
55 		fn = __CTOR_END__[-n];
56 		if (fn == (crt_func)0 || fn == (crt_func)-1)
57 			break;
58 		fn();
59 	}
60 }
61 
62 asm (
63     ".pushsection .init		\n"
64     "\t" INIT_CALL_SEQ(__do_global_ctors_aux) "\n"
65     ".popsection		\n"
66 );
67 #endif
68