1 /*****************************************************************************
2 * modules_plugin.h : Plugin management functions used by the core application.
3 *****************************************************************************
4 * Copyright (C) 2001 VideoLAN
5 * $Id: modules_plugin.h.in,v 1.10 2003/07/01 12:50:56 sam Exp $
7 * Authors: Samuel Hocevar <sam@zoy.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
22 *****************************************************************************/
24 /*****************************************************************************
25 * Inline functions for handling dynamic modules
26 *****************************************************************************/
28 /*****************************************************************************
29 * module_load: load a dynamic library
30 *****************************************************************************
31 * This function loads a dynamically linked library using a system dependant
32 * method, and returns a non-zero value on error, zero otherwise.
33 *****************************************************************************/
34 static int module_load( const MYCHAR * psz_filename, module_handle_t * handle )
37 *handle = load_add_on( psz_filename );
38 return( *handle < 0 );
40 #elif defined(WIN32) || defined(UNDER_CE)
41 *handle = LoadLibrary( psz_filename );
42 return( *handle == NULL );
44 #elif defined(RTLD_NOW)
45 /* static is OK, we are called atomically */
46 static vlc_bool_t b_kde = VLC_FALSE;
48 # if defined(SYS_LINUX)
49 /* XXX HACK #1 - we should NOT open modules with RTLD_GLOBAL, or we
50 * are going to get namespace collisions when two modules have common
51 * public symbols, but ALSA is being a pest here. */
52 if( strstr( psz_filename, "alsa_plugin" ) )
54 *handle = dlopen( psz_filename, RTLD_NOW | RTLD_GLOBAL );
55 return( *handle == NULL );
58 /* XXX HACK #2 - the ugly KDE workaround. It seems that libkdewhatever
59 * causes dlopen() to segfault if libstdc++ is not loaded in the caller,
60 * so we just load libstdc++. Bwahahaha! ph34r! -- Sam. */
61 /* Update: FYI, this is Debian bug #180505, and seems to be fixed. */
62 if( !b_kde && !strstr( psz_filename, "kde" ) )
64 dlopen( "libstdc++.so.6", RTLD_NOW )
65 || dlopen( "libstdc++.so.5", RTLD_NOW )
66 || dlopen( "libstdc++.so.4", RTLD_NOW )
67 || dlopen( "libstdc++.so.3", RTLD_NOW );
71 *handle = dlopen( psz_filename, RTLD_NOW );
72 return( *handle == NULL );
75 *handle = dlopen( psz_filename, DL_LAZY );
76 return( *handle == NULL );
81 /*****************************************************************************
82 * module_unload: unload a dynamic library
83 *****************************************************************************
84 * This function unloads a previously opened dynamically linked library
85 * using a system dependant method. No return value is taken in consideration,
86 * since some libraries sometimes refuse to close properly.
87 *****************************************************************************/
88 static void module_unload( module_handle_t handle )
91 unload_add_on( handle );
93 #elif defined(WIN32) || defined(UNDER_CE)
94 FreeLibrary( handle );
103 /*****************************************************************************
104 * module_getsymbol: get a symbol from a dynamic library
105 *****************************************************************************
106 * This function queries a loaded library for a symbol specified in a
107 * string, and returns a pointer to it. We don't check for dlerror() or
108 * similar functions, since we want a non-NULL symbol anyway.
109 *****************************************************************************/
110 static void * _module_getsymbol( module_handle_t handle,
111 const char * psz_function )
115 if( B_OK == get_image_symbol( handle, psz_function,
116 B_SYMBOL_TYPE_TEXT, &p_symbol ) )
125 #elif defined( UNDER_CE )
126 wchar_t psz_real[256];
127 MultiByteToWideChar( CP_ACP, 0, psz_function, -1, psz_real, 256 );
129 return (void *)GetProcAddress( handle, psz_real );
131 #elif defined( WIN32 )
132 return (void *)GetProcAddress( handle, (MYCHAR*)psz_function );
135 return dlsym( handle, psz_function );
140 static void * module_getsymbol( module_handle_t handle,
141 const char * psz_function )
143 void * p_symbol = _module_getsymbol( handle, psz_function );
145 /* MacOS X dl library expects symbols to begin with "_". So do
146 * some other operating systems. That's really lame, but hey, what
148 if( p_symbol == NULL )
150 char *psz_call = malloc( strlen( psz_function ) + 2 );
152 strcpy( psz_call + 1, psz_function );
154 p_symbol = _module_getsymbol( handle, psz_call );
161 /*****************************************************************************
162 * module_error: wrapper for dlerror()
163 *****************************************************************************
164 * This function returns the error message of the last module operation. It
165 * returns the string "failed" on systems which do not have a dlerror() like
166 * function. psz_buffer can be used to store temporary data, it is guaranteed
167 * to be kept intact until the return value of module_error has been used.
168 *****************************************************************************/
169 static const char * module_error( char *psz_buffer )
171 #if defined(SYS_BEOS)
174 #elif defined(UNDER_CE)
175 wchar_t psz_tmp[256];
177 int i, i_error = GetLastError();
179 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
180 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
181 (LPTSTR) psz_tmp, 256, NULL );
183 /* Go to the end of the string */
185 psz_tmp[i] && psz_tmp[i] != L'\r' && psz_tmp[i] != L'\n';
190 swprintf( psz_tmp + i, L" (error %i)", i_error );
191 psz_tmp[ 255 ] = L'\0';
194 WideCharToMultiByte( CP_ACP, WC_DEFAULTCHAR, psz_tmp, -1,
195 psz_buffer, 256, NULL, NULL );
200 int i, i_error = GetLastError();
202 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
203 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
204 (LPTSTR) psz_buffer, 256, NULL );
206 /* Go to the end of the string */
208 psz_buffer[i] && psz_buffer[i] != '\r' && psz_buffer[i] != '\n';
213 snprintf( psz_buffer + i, 256 - i, " (error %i)", i_error );
214 psz_buffer[ 255 ] = '\0';
225 /*****************************************************************************
226 * STORE_SYMBOLS: store known symbols into p_symbols for plugin access.
227 *****************************************************************************/