xref: /openbsd/lib/libc/dlfcn/dlfcn_stubs.c (revision 9b7c3dbb)
1 /*	$OpenBSD: dlfcn_stubs.c,v 1.13 2015/11/01 03:00:01 guenther Exp $	*/
2 
3 /*
4  * Copyright (c) 1998 Per Fogelstrom, Opsycon AB
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  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  */
28 
29 #include <stddef.h>
30 
31 /*
32  *	All functions here are just stubs that will be overridden
33  *	by the real functions in ld.so when dynamic loading is
34  *	performed at exec. The symbols here are provided as a link
35  *	helper so we can link a program using the dl functions
36  *	without getting any unresolved references.
37  */
38 
39 void	*dlopen(const char *libname, int how) __attribute__((weak));
40 int	 dlclose(void *handle) __attribute__((weak));
41 void	*dlsym(void *handle, const char *name) __attribute__((weak));
42 int	 dlctl(void *handle, int command, void *data) __attribute__((weak));
43 char 	*dlerror(void) __attribute__((weak));
44 
45 struct dl_info;
46 int	dladdr(const void *addr, struct dl_info *info) __attribute__((weak));
47 
48 struct dl_phdr_info;
49 int	 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),	    void *date) __attribute__((weak));
50 
51 #include <stdio.h>
52 
53 void *
54 dlopen(const char *libname, int how)
55 {
56 	printf("Wrong dl symbols!\n");
57 	return NULL;
58 }
59 
60 int
61 dlclose(void *handle)
62 {
63 	printf("Wrong dl symbols!\n");
64 	return 0;
65 }
66 
67 void *
68 dlsym(void *handle, const char *name)
69 {
70 	printf("Wrong dl symbols!\n");
71 	return NULL;
72 }
73 
74 int
75 dlctl(void *handle, int command, void *data)
76 {
77 	return -1;
78 }
79 
80 char *
81 dlerror(void)
82 {
83 	return "Wrong dl symbols!\n";
84 }
85 
86 int
87 dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *),
88 	void *data)
89 {
90 	return -1;
91 }
92 
93 int
94 dladdr(const void *addr, struct dl_info *info)
95 {
96 	printf("Wrong dl symbols!\n");
97 	return -1;
98 }
99