xref: /freebsd/lib/csu/common/crtbegin.c (revision fe2494903422ba3b924eba82cb63a6a9188fad7a)
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 extern void *__dso_handle __hidden;
34 
35 #ifdef SHARED
36 void *__dso_handle = &__dso_handle;
37 #else
38 void *__dso_handle = 0;
39 #endif
40 
41 /*
42  * On some architectures and toolchains we may need to call the .dtors.
43  * These are called in the order they are in the ELF file.
44  */
45 #ifdef HAVE_CTORS
46 static void __do_global_dtors_aux(void) __used;
47 
48 static crt_func __CTOR_LIST__[] __section(".ctors") __used = {
49 	(crt_func)-1
50 };
51 static crt_func __DTOR_LIST__[] __section(".dtors") __used = {
52 	(crt_func)-1
53 };
54 
55 static void
56 __do_global_dtors_aux(void)
57 {
58 	crt_func fn;
59 	int n;
60 
61 	for (n = 1;; n++) {
62 		fn = __DTOR_LIST__[n];
63 		if (fn == (crt_func)0 || fn == (crt_func)-1)
64 			break;
65 		fn();
66 	}
67 }
68 
69 asm (
70     ".pushsection .fini		\n"
71     "\t" INIT_CALL_SEQ(__do_global_dtors_aux) "\n"
72     ".popsection		\n"
73 );
74 #endif
75 
76 /*
77  * Handler for gcj. These provide a _Jv_RegisterClasses function and fill
78  * out the .jcr section. We just need to call this function with a pointer
79  * to the appropriate section.
80  */
81 extern void _Jv_RegisterClasses(void *) __weak_symbol;
82 static void register_classes(void) __used;
83 
84 static crt_func __JCR_LIST__[] __section(".jcr") __used = { };
85 
86 #ifndef CTORS_CONSTRUCTORS
87 __attribute__((constructor))
88 #endif
89 static void
90 register_classes(void)
91 {
92 
93 	if (_Jv_RegisterClasses != NULL && __JCR_LIST__[0] != 0)
94 		_Jv_RegisterClasses(__JCR_LIST__);
95 }
96 
97 /*
98  * We can't use constructors when they use the .ctors section as they may be
99  * placed before __CTOR_LIST__.
100  */
101 #ifdef CTORS_CONSTRUCTORS
102 asm (
103     ".pushsection .init		\n"
104     "\t" INIT_CALL_SEQ(register_classes) "\n"
105     ".popsection		\n"
106 );
107 #endif
108