xref: /freebsd/lib/csu/common/crtbegin.c (revision 31d62a73c2e6ac0ff413a7a17700ffc7dce254ef)
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 <sys/param.h>
28 
29 #include "crt.h"
30 
31 typedef void (*crt_func)(void);
32 
33 /*
34  * On some architectures and toolchains we may need to call the .dtors.
35  * These are called in the order they are in the ELF file.
36  */
37 #ifdef HAVE_CTORS
38 static void __do_global_dtors_aux(void) __used;
39 
40 crt_func __CTOR_LIST__[] __section(".ctors") __hidden = {
41 	(crt_func)-1
42 };
43 crt_func __DTOR_LIST__[] __section(".dtors") __hidden = {
44 	(crt_func)-1
45 };
46 
47 static void
48 __do_global_dtors_aux(void)
49 {
50 	crt_func fn;
51 	int n;
52 
53 	for (n = 1;; n++) {
54 		fn = __DTOR_LIST__[n];
55 		if (fn == (crt_func)0 || fn == (crt_func)-1)
56 			break;
57 		fn();
58 	}
59 }
60 
61 asm (
62     ".pushsection .fini		\n"
63     "\t" INIT_CALL_SEQ(__do_global_dtors_aux) "\n"
64     ".popsection		\n"
65 );
66 #endif
67 
68 /*
69  * Handler for gcj. These provide a _Jv_RegisterClasses function and fill
70  * out the .jcr section. We just need to call this function with a pointer
71  * to the appropriate section.
72  */
73 extern void _Jv_RegisterClasses(void *) __weak_symbol;
74 static void register_classes(void) __used;
75 
76 crt_func __JCR_LIST__[] __section(".jcr") __used __hidden = { };
77 
78 #ifndef CTORS_CONSTRUCTORS
79 __attribute__((constructor))
80 #endif
81 static void
82 register_classes(void)
83 {
84 
85 	if (_Jv_RegisterClasses != NULL && __JCR_LIST__[0] != 0)
86 		_Jv_RegisterClasses(__JCR_LIST__);
87 }
88 
89 /*
90  * We can't use constructors when they use the .ctors section as they may be
91  * placed before __CTOR_LIST__.
92  */
93 #ifdef CTORS_CONSTRUCTORS
94 asm (
95     ".pushsection .init		\n"
96     "\t" INIT_CALL_SEQ(register_classes) "\n"
97     ".popsection		\n"
98 );
99 #endif
100