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8d138742 CE |
1 | /* loader-dld_link.c -- dynamic linking with dld |
2 | ||
3 | Copyright (C) 1998, 1999, 2000, 2004, 2006, | |
4 | 2007, 2008 Free Software Foundation, Inc. | |
5 | Written by Thomas Tanner, 1998 | |
6 | ||
7 | NOTE: The canonical source of this file is maintained with the | |
8 | GNU Libtool package. Report bugs to bug-libtool@gnu.org. | |
9 | ||
10 | GNU Libltdl is free software; you can redistribute it and/or | |
11 | modify it under the terms of the GNU Lesser General Public | |
12 | License as published by the Free Software Foundation; either | |
13 | version 2 of the License, or (at your option) any later version. | |
14 | ||
15 | As a special exception to the GNU Lesser General Public License, | |
16 | if you distribute this file as part of a program or library that | |
17 | is built using GNU Libtool, you may include this file under the | |
18 | same distribution terms that you use for the rest of that program. | |
19 | ||
20 | GNU Libltdl is distributed in the hope that it will be useful, | |
21 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
22 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
23 | GNU Lesser General Public License for more details. | |
24 | ||
25 | You should have received a copy of the GNU Lesser General Public | |
26 | License along with GNU Libltdl; see the file COPYING.LIB. If not, a | |
27 | copy can be downloaded from http://www.gnu.org/licenses/lgpl.html, | |
28 | or obtained by writing to the Free Software Foundation, Inc., | |
29 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. | |
30 | */ | |
31 | ||
32 | #include "lt__private.h" | |
33 | #include "lt_dlloader.h" | |
34 | ||
35 | /* Use the preprocessor to rename non-static symbols to avoid namespace | |
36 | collisions when the loader code is statically linked into libltdl. | |
37 | Use the "<module_name>_LTX_" prefix so that the symbol addresses can | |
38 | be fetched from the preloaded symbol list by lt_dlsym(): */ | |
39 | #define get_vtable dld_link_LTX_get_vtable | |
40 | ||
41 | LT_BEGIN_C_DECLS | |
42 | LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data); | |
43 | LT_END_C_DECLS | |
44 | ||
45 | ||
46 | /* Boilerplate code to set up the vtable for hooking this loader into | |
47 | libltdl's loader list: */ | |
48 | static int vl_exit (lt_user_data loader_data); | |
49 | static lt_module vm_open (lt_user_data loader_data, const char *filename, | |
50 | lt_dladvise advise); | |
51 | static int vm_close (lt_user_data loader_data, lt_module module); | |
52 | static void * vm_sym (lt_user_data loader_data, lt_module module, | |
53 | const char *symbolname); | |
54 | ||
55 | static lt_dlvtable *vtable = 0; | |
56 | ||
57 | /* Return the vtable for this loader, only the name and sym_prefix | |
58 | attributes (plus the virtual function implementations, obviously) | |
59 | change between loaders. */ | |
60 | lt_dlvtable * | |
61 | get_vtable (lt_user_data loader_data) | |
62 | { | |
63 | if (!vtable) | |
64 | { | |
65 | vtable = lt__zalloc (sizeof *vtable); | |
66 | } | |
67 | ||
68 | if (vtable && !vtable->name) | |
69 | { | |
70 | vtable->name = "lt_dld_link"; | |
71 | vtable->module_open = vm_open; | |
72 | vtable->module_close = vm_close; | |
73 | vtable->find_sym = vm_sym; | |
74 | vtable->dlloader_exit = vl_exit; | |
75 | vtable->dlloader_data = loader_data; | |
76 | vtable->priority = LT_DLLOADER_APPEND; | |
77 | } | |
78 | ||
79 | if (vtable && (vtable->dlloader_data != loader_data)) | |
80 | { | |
81 | LT__SETERROR (INIT_LOADER); | |
82 | return 0; | |
83 | } | |
84 | ||
85 | return vtable; | |
86 | } | |
87 | ||
88 | ||
89 | ||
90 | /* --- IMPLEMENTATION --- */ | |
91 | ||
92 | ||
93 | #if defined(HAVE_DLD_H) | |
94 | # include <dld.h> | |
95 | #endif | |
96 | ||
97 | /* A function called through the vtable when this loader is no | |
98 | longer needed by the application. */ | |
99 | static int | |
100 | vl_exit (lt_user_data LT__UNUSED loader_data) | |
101 | { | |
102 | vtable = NULL; | |
103 | return 0; | |
104 | } | |
105 | ||
106 | /* A function called through the vtable to open a module with this | |
107 | loader. Returns an opaque representation of the newly opened | |
108 | module for processing with this loader's other vtable functions. */ | |
109 | static lt_module | |
110 | vm_open (lt_user_data LT__UNUSED loader_data, const char *filename, | |
111 | lt_dladvise LT__UNUSED advise) | |
112 | { | |
113 | lt_module module = lt__strdup (filename); | |
114 | ||
115 | if (dld_link (filename) != 0) | |
116 | { | |
117 | LT__SETERROR (CANNOT_OPEN); | |
118 | FREE (module); | |
119 | } | |
120 | ||
121 | return module; | |
122 | } | |
123 | ||
124 | /* A function called through the vtable when a particular module | |
125 | should be unloaded. */ | |
126 | static int | |
127 | vm_close (lt_user_data LT__UNUSED loader_data, lt_module module) | |
128 | { | |
129 | int errors = 0; | |
130 | ||
131 | if (dld_unlink_by_file ((char*)(module), 1) != 0) | |
132 | { | |
133 | LT__SETERROR (CANNOT_CLOSE); | |
134 | ++errors; | |
135 | } | |
136 | else | |
137 | { | |
138 | FREE (module); | |
139 | } | |
140 | ||
141 | return errors; | |
142 | } | |
143 | ||
144 | /* A function called through the vtable to get the address of | |
145 | a symbol loaded from a particular module. */ | |
146 | static void * | |
147 | vm_sym (lt_user_data LT__UNUSED loader_data, lt_module LT__UNUSED module, | |
148 | const char *name) | |
149 | { | |
150 | void *address = dld_get_func (name); | |
151 | ||
152 | if (!address) | |
153 | { | |
154 | LT__SETERROR (SYMBOL_NOT_FOUND); | |
155 | } | |
156 | ||
157 | return address; | |
158 | } |