xref: /openbsd-src/lib/csu/crtbegin.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: crtbegin.c,v 1.13 2009/04/13 20:15:24 kurt Exp $	*/
2 /*	$NetBSD: crtbegin.c,v 1.1 1996/09/12 16:59:03 cgd Exp $	*/
3 
4 /*
5  * Copyright (c) 1993 Paul Kranenburg
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed by Paul Kranenburg.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Run-time module for GNU C++ compiled shared libraries.
36  *
37  * The linker constructs the following arrays of pointers to global
38  * constructors and destructors. The first element contains the
39  * number of pointers in each.
40  * The tables are also null-terminated.
41  */
42 #include <stdlib.h>
43 
44 #include "md_init.h"
45 #include "os-note-elf.h"
46 #include "extern.h"
47 
48 struct dwarf2_eh_object {
49 	void *space[8];
50 };
51 
52 void __register_frame_info(const void *, struct dwarf2_eh_object *)
53     __attribute__((weak));
54 
55 void __register_frame_info(const void *begin, struct dwarf2_eh_object *ob)
56 {
57 }
58 
59 static const char __EH_FRAME_BEGIN__[]
60     __attribute__((section(".eh_frame"), aligned(4))) = { };
61 
62 /*
63  * java class registration hooks
64  */
65 
66 #if (__GNUC__ > 2)
67 static void *__JCR_LIST__[]
68     __attribute__((section(".jcr"), aligned(sizeof(void*)))) = { };
69 
70 extern void _Jv_RegisterClasses (void *)
71     __attribute__((weak));
72 #endif
73 
74 /*
75  * Include support for the __cxa_atexit/__cxa_finalize C++ abi for
76  * gcc > 2.x. __dso_handle is NULL in the main program and a unique
77  * value for each C++ shared library. For more info on this API, see:
78  *
79  *     http://www.codesourcery.com/cxx-abi/abi.html#dso-dtor
80  */
81 
82 #if (__GNUC__ > 2)
83 void *__dso_handle = NULL;
84 __asm(".hidden  __dso_handle");
85 #endif
86 
87 static const init_f __CTOR_LIST__[1]
88     __attribute__((section(".ctors"))) = { (void *)-1 };	/* XXX */
89 static const init_f __DTOR_LIST__[1]
90     __attribute__((section(".dtors"))) = { (void *)-1 };	/* XXX */
91 
92 static void	__dtors(void);
93 static void	__ctors(void);
94 
95 static void
96 __dtors()
97 {
98 	unsigned long i = (unsigned long) __DTOR_LIST__[0];
99 	const init_f *p;
100 
101 	if (i == -1)  {
102 		for (i = 1; __DTOR_LIST__[i] != NULL; i++)
103 			;
104 		i--;
105 	}
106 	p = __DTOR_LIST__ + i;
107 	while (i--)
108 		(**p--)();
109 }
110 
111 static void
112 __ctors()
113 {
114 	const init_f *p = __CTOR_LIST__ + 1;
115 
116 	while (*p)
117 		(**p++)();
118 }
119 
120 void __init(void);
121 void __fini(void);
122 static void __do_init(void);
123 static void __do_fini(void);
124 
125 MD_SECTION_PROLOGUE(".init", __init);
126 
127 MD_SECTION_PROLOGUE(".fini", __fini);
128 
129 MD_SECT_CALL_FUNC(".init", __do_init);
130 MD_SECT_CALL_FUNC(".fini", __do_fini);
131 
132 
133 void
134 __do_init()
135 {
136 	static int initialized = 0;
137 	static struct dwarf2_eh_object object;
138 
139 	/*
140 	 * Call global constructors.
141 	 * Arrange to call global destructors at exit.
142 	 */
143 	if (!initialized) {
144 		initialized = 1;
145 
146 		__register_frame_info(__EH_FRAME_BEGIN__, &object);
147 
148 #if (__GNUC__ > 2)
149 		if (__JCR_LIST__[0] && _Jv_RegisterClasses)
150 			_Jv_RegisterClasses(__JCR_LIST__);
151 #endif
152 
153 		(__ctors)();
154 
155 		atexit(__fini);
156 	}
157 }
158 
159 void
160 __do_fini()
161 {
162 	static int finalized = 0;
163 
164 	if (!finalized) {
165 		finalized = 1;
166 		/*
167 		 * Call global destructors.
168 		 */
169 		(__dtors)();
170 	}
171 }
172 
173