1 /* ltdl.h -- generic dlopen functions
2 
3    Copyright (C) 1998-2000, 2004, 2005,
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 /* Only include this header file once. */
33 #if !defined(LTDL_H)
34 #define LTDL_H 1
35 
36 #include <libltdl/lt_system.h>
37 #include <libltdl/lt_error.h>
38 #include <libltdl/lt_dlloader.h>
39 
40 LT_BEGIN_C_DECLS
41 
42 
43 /* LT_STRLEN can be used safely on NULL pointers.  */
44 #define LT_STRLEN(s)	(((s) && (s)[0]) ? strlen (s) : 0)
45 
46 
47 /* --- DYNAMIC MODULE LOADING API --- */
48 
49 
50 typedef	struct lt__handle *lt_dlhandle;	/* A loaded module.  */
51 
52 /* Initialisation and finalisation functions for libltdl. */
53 LT_SCOPE int	    lt_dlinit		(void);
54 LT_SCOPE int	    lt_dlexit		(void);
55 
56 /* Module search path manipulation.  */
57 LT_SCOPE int	    lt_dladdsearchdir	 (const char *search_dir);
58 LT_SCOPE int	    lt_dlinsertsearchdir (const char *before,
59 						  const char *search_dir);
60 LT_SCOPE int 	    lt_dlsetsearchpath	 (const char *search_path);
61 LT_SCOPE const char *lt_dlgetsearchpath	 (void);
62 LT_SCOPE int	    lt_dlforeachfile	 (
63 			const char *search_path,
64 			int (*func) (const char *filename, void *data),
65 			void *data);
66 
67 /* User module loading advisors.  */
68 LT_SCOPE int	    lt_dladvise_init	 (lt_dladvise *advise);
69 LT_SCOPE int	    lt_dladvise_destroy  (lt_dladvise *advise);
70 LT_SCOPE int	    lt_dladvise_ext	 (lt_dladvise *advise);
71 LT_SCOPE int	    lt_dladvise_resident (lt_dladvise *advise);
72 LT_SCOPE int	    lt_dladvise_local	 (lt_dladvise *advise);
73 LT_SCOPE int	    lt_dladvise_global   (lt_dladvise *advise);
74 LT_SCOPE int	    lt_dladvise_preload	 (lt_dladvise *advise);
75 
76 /* Portable libltdl versions of the system dlopen() API. */
77 LT_SCOPE lt_dlhandle lt_dlopen		(const char *filename);
78 LT_SCOPE lt_dlhandle lt_dlopenext	(const char *filename);
79 LT_SCOPE lt_dlhandle lt_dlopenadvise	(const char *filename,
80 					 lt_dladvise advise);
81 LT_SCOPE void *	    lt_dlsym		(lt_dlhandle handle, const char *name);
82 LT_SCOPE const char *lt_dlerror		(void);
83 LT_SCOPE int	    lt_dlclose		(lt_dlhandle handle);
84 
85 
86 
87 /* --- PRELOADED MODULE SUPPORT --- */
88 
89 
90 /* A preopened symbol. Arrays of this type comprise the exported
91    symbols for a dlpreopened module. */
92 typedef struct {
93   const char *name;
94   void       *address;
95 } lt_dlsymlist;
96 
97 typedef int lt_dlpreload_callback_func (lt_dlhandle handle);
98 
99 LT_SCOPE int	lt_dlpreload	     (const lt_dlsymlist *preloaded);
100 LT_SCOPE int	lt_dlpreload_default (const lt_dlsymlist *preloaded);
101 LT_SCOPE int	lt_dlpreload_open    (const char *originator,
102 				      lt_dlpreload_callback_func *func);
103 
104 #define lt_preloaded_symbols	lt__PROGRAM__LTX_preloaded_symbols
105 /* Ensure C linkage.  */
106 extern LT_DLSYM_CONST lt_dlsymlist lt__PROGRAM__LTX_preloaded_symbols[];
107 
108 #define LTDL_SET_PRELOADED_SYMBOLS() \
109 	lt_dlpreload_default(lt_preloaded_symbols)
110 
111 
112 
113 
114 /* --- MODULE INFORMATION --- */
115 
116 
117 /* Associating user data with loaded modules. */
118 typedef void * lt_dlinterface_id;
119 typedef int lt_dlhandle_interface (lt_dlhandle handle, const char *id_string);
120 
121 LT_SCOPE lt_dlinterface_id lt_dlinterface_register (const char *id_string,
122 					  lt_dlhandle_interface *iface);
123 LT_SCOPE void	lt_dlinterface_free (lt_dlinterface_id key);
124 LT_SCOPE void *	lt_dlcaller_set_data  (lt_dlinterface_id key,
125 					  lt_dlhandle handle, void *data);
126 LT_SCOPE void *	lt_dlcaller_get_data  (lt_dlinterface_id key,
127 					  lt_dlhandle handle);
128 
129 
130 /* Read only information pertaining to a loaded module. */
131 typedef	struct {
132   char *	filename;	/* file name */
133   char *	name;		/* module name */
134   int		ref_count;	/* number of times lt_dlopened minus
135 				   number of times lt_dlclosed. */
136   unsigned int	is_resident:1;	/* module can't be unloaded. */
137   unsigned int	is_symglobal:1;	/* module symbols can satisfy
138 				   subsequently loaded modules.  */
139   unsigned int	is_symlocal:1;	/* module symbols are only available
140 				   locally. */
141 } lt_dlinfo;
142 
143 LT_SCOPE const lt_dlinfo *lt_dlgetinfo	    (lt_dlhandle handle);
144 
145 LT_SCOPE lt_dlhandle	lt_dlhandle_iterate (lt_dlinterface_id iface,
146 					     lt_dlhandle place);
147 LT_SCOPE lt_dlhandle	lt_dlhandle_fetch   (lt_dlinterface_id iface,
148 					     const char *module_name);
149 LT_SCOPE int		lt_dlhandle_map	    (lt_dlinterface_id iface,
150 				int (*func) (lt_dlhandle handle, void *data),
151 				void *data);
152 
153 
154 
155 /* Deprecated module residency management API. */
156 LT_SCOPE int	    lt_dlmakeresident	(lt_dlhandle handle);
157 LT_SCOPE int	    lt_dlisresident	(lt_dlhandle handle);
158 
159 #define lt_ptr void *
160 
161 LT_END_C_DECLS
162 
163 #endif /*!defined(LTDL_H)*/
164