1 /*****************************************************************************
2 * os.c : Low-level dynamic library handling
3 *****************************************************************************
4 * Copyright (C) 2001-2007 the VideoLAN team
7 * Authors: Sam Hocevar <sam@zoy.org>
8 * Ethan C. Baldridge <BaldridgeE@cadmus.com>
9 * Hans-Peter Jansen <hpj@urpla.net>
10 * Gildas Bazin <gbazin@videolan.org>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
25 *****************************************************************************/
31 #include <vlc_common.h>
32 #include <vlc_plugin.h> /* MODULE_SUFFIX */
33 #include <vlc_charset.h>
37 #include <stdlib.h> /* free(), strtol() */
38 #include <stdio.h> /* sprintf() */
39 #include <string.h> /* strdup() */
41 #include <sys/types.h>
43 #if !defined(HAVE_DYNAMIC_PLUGINS)
44 /* no support for plugins */
45 #elif defined(HAVE_DL_BEOS)
46 # if defined(HAVE_IMAGE_H)
49 #elif defined(__APPLE__)
51 #elif defined(HAVE_DL_WINDOWS)
53 #elif defined(HAVE_DL_DLOPEN)
54 # if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
57 # if defined(HAVE_SYS_DL_H)
60 #elif defined(HAVE_DL_SHL_LOAD)
61 # if defined(HAVE_DL_H)
65 #ifdef HAVE_VALGRIND_VALGRIND_H
66 # include <valgrind/valgrind.h>
69 /*****************************************************************************
71 *****************************************************************************/
72 #ifdef HAVE_DYNAMIC_PLUGINS
73 static void *module_Lookup( module_handle_t, const char * );
75 #if defined(HAVE_DL_WINDOWS)
76 static char * GetWindowsError ( void );
82 * Call a symbol given its name and a module structure. The symbol MUST
83 * refer to a function returning int and taking a module_t* as an argument.
84 * \param p_module the modules
85 * \return 0 if it pass and -1 in case of a failure
87 int module_Call( vlc_object_t *obj, module_t *p_module )
89 static const char psz_name[] = "vlc_entry" MODULE_SUFFIX;
90 int (* pf_symbol) ( module_t * p_module );
92 /* Try to resolve the symbol */
93 pf_symbol = (int (*)(module_t *)) module_Lookup( p_module->handle,
96 if( pf_symbol == NULL )
98 #if defined(HAVE_DL_BEOS)
99 msg_Warn( obj, "cannot find symbol \"%s\" in file `%s'",
100 psz_name, p_module->psz_filename );
101 #elif defined(HAVE_DL_WINDOWS)
102 char *psz_error = GetWindowsError();
103 msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
104 psz_name, p_module->psz_filename, psz_error );
106 #elif defined(HAVE_DL_DLOPEN)
107 msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
108 psz_name, p_module->psz_filename, dlerror() );
109 #elif defined(HAVE_DL_SHL_LOAD)
110 msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%m)",
111 psz_name, p_module->psz_filename );
113 # error "Something is wrong in modules.c"
118 /* We can now try to call the symbol */
119 if( pf_symbol( p_module ) != 0 )
121 /* With a well-written module we shouldn't have to print an
122 * additional error message here, but just make sure. */
123 msg_Err( obj, "Failed to call symbol \"%s\" in file `%s'",
124 psz_name, p_module->psz_filename );
128 /* Everything worked fine, we can return */
133 * Load a dynamically linked library using a system dependent method.
135 * \param p_this vlc object
136 * \param psz_file library file
137 * \param p_handle the module handle returned
138 * \return 0 on success as well as the module handle.
140 int module_Load( vlc_object_t *p_this, const char *psz_file,
141 module_handle_t *p_handle )
143 module_handle_t handle;
145 #if defined(HAVE_DL_BEOS)
146 handle = load_add_on( psz_file );
149 msg_Warn( p_this, "cannot load module `%s'", psz_file );
153 #elif defined(HAVE_DL_WINDOWS)
154 wchar_t psz_wfile[MAX_PATH];
155 MultiByteToWideChar( CP_UTF8, 0, psz_file, -1, psz_wfile, MAX_PATH );
158 /* FIXME: this is not thread-safe -- Courmisch */
159 UINT mode = SetErrorMode (SEM_FAILCRITICALERRORS);
160 SetErrorMode (mode|SEM_FAILCRITICALERRORS);
163 handle = LoadLibraryW( psz_wfile );
171 char *psz_err = GetWindowsError();
172 msg_Warn( p_this, "cannot load module `%s' (%s)", psz_file, psz_err );
177 #elif defined(HAVE_DL_DLOPEN)
179 # if defined (RTLD_NOW)
180 const int flags = RTLD_NOW;
181 # elif defined (DL_LAZY)
182 const int flags = DL_LAZY;
186 char *path = ToLocale( psz_file );
188 handle = dlopen( path, flags );
191 msg_Warn( p_this, "cannot load module `%s' (%s)", path, dlerror() );
197 #elif defined(HAVE_DL_SHL_LOAD)
198 handle = shl_load( psz_file, BIND_IMMEDIATE | BIND_NONFATAL, NULL );
201 msg_Warn( p_this, "cannot load module `%s' (%m)", psz_file );
206 # error "Something is wrong in modules.c"
215 * CloseModule: unload a dynamic library
217 * This function unloads a previously opened dynamically linked library
218 * using a system dependent method. No return value is taken in consideration,
219 * since some libraries sometimes refuse to close properly.
220 * \param handle handle of the library
223 void module_Unload( module_handle_t handle )
225 #if defined(HAVE_DL_BEOS)
226 unload_add_on( handle );
228 #elif defined(HAVE_DL_WINDOWS)
229 FreeLibrary( handle );
231 #elif defined(HAVE_DL_DLOPEN)
232 # ifdef HAVE_VALGRIND_VALGRIND_H
233 if( RUNNING_ON_VALGRIND > 0 )
234 return; /* do not dlclose() so that we get proper stack traces */
238 #elif defined(HAVE_DL_SHL_LOAD)
239 shl_unload( handle );
246 * Looks up a symbol from a dynamically loaded library
248 * This function queries a loaded library for a symbol specified in a
249 * string, and returns a pointer to it. We don't check for dlerror() or
250 * similar functions, since we want a non-NULL symbol anyway.
252 * @param handle handle to the module
253 * @param psz_function function name
254 * @return NULL on error, or the address of the symbol
256 static void *module_Lookup( module_handle_t handle, const char *psz_function )
258 #if defined(HAVE_DL_BEOS)
260 if( B_OK == get_image_symbol( handle, psz_function,
261 B_SYMBOL_TYPE_TEXT, &p_symbol ) )
270 #elif defined(HAVE_DL_WINDOWS) && defined(UNDER_CE)
271 wchar_t wide[strlen( psz_function ) + 1];
274 wide[i] = psz_function[i]; /* UTF-16 <- ASCII */
275 while( psz_function[i++] );
277 return (void *)GetProcAddress( handle, wide );
279 #elif defined(HAVE_DL_WINDOWS) && defined(WIN32)
280 return (void *)GetProcAddress( handle, (char *)psz_function );
282 #elif defined(HAVE_DL_DLOPEN)
283 return dlsym( handle, psz_function );
285 #elif defined(HAVE_DL_SHL_LOAD)
287 shl_findsym( &handle, psz_function, TYPE_UNDEFINED, &p_sym );
293 #if defined(HAVE_DL_WINDOWS)
296 static char * GetWindowsError( void )
299 int i = 0, i_error = GetLastError();
301 FormatMessageW( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
302 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
305 /* Go to the end of the string */
306 while( !wmemchr( L"\r\n\0", wmsg[i], 3 ) )
309 snwprintf( wmsg + i, 256 - i, L" (error %i)", i_error );
310 return FromWide( wmsg );
312 #endif /* HAVE_DL_WINDOWS */
313 #endif /* HAVE_DYNAMIC_PLUGINS */