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)
294 static char * GetWindowsError( void )
296 #if defined(UNDER_CE)
297 wchar_t psz_tmp
[MAX_PATH
];
298 char * psz_buffer
= malloc( MAX_PATH
);
300 char * psz_tmp
= malloc( MAX_PATH
);
302 int i
= 0, i_error
= GetLastError();
304 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM
| FORMAT_MESSAGE_IGNORE_INSERTS
,
305 NULL
, i_error
, MAKELANGID (LANG_NEUTRAL
, SUBLANG_DEFAULT
),
306 (LPTSTR
)psz_tmp
, MAX_PATH
, NULL
);
308 /* Go to the end of the string */
309 while( psz_tmp
[i
] && psz_tmp
[i
] != _T('\r') && psz_tmp
[i
] != _T('\n') )
316 #if defined(UNDER_CE)
317 swprintf( psz_tmp
+ i
, L
" (error %i)", i_error
);
318 psz_tmp
[ 255 ] = L
'\0';
320 snprintf( psz_tmp
+ i
, 256 - i
, " (error %i)", i_error
);
321 psz_tmp
[ 255 ] = '\0';
325 #if defined(UNDER_CE)
326 wcstombs( psz_buffer
, psz_tmp
, MAX_PATH
);
332 #endif /* HAVE_DL_WINDOWS */
333 #endif /* HAVE_DYNAMIC_PLUGINS */