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 1.7 2002/11/18 18:05:13 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 # if defined(SYS_LINUX)
46 /* We should NOT open modules with RTLD_GLOBAL, or we are going to get
47 * namespace collisions when two modules have common public symbols,
48 * but ALSA is being a pest here. */
49 if( strstr( psz_filename, "alsa" ) )
51 *handle = dlopen( psz_filename, RTLD_NOW | RTLD_GLOBAL );
52 return( *handle == NULL );
55 *handle = dlopen( psz_filename, RTLD_NOW );
56 return( *handle == NULL );
59 *handle = dlopen( psz_filename, DL_LAZY );
60 return( *handle == NULL );
65 /*****************************************************************************
66 * module_unload: unload a dynamic library
67 *****************************************************************************
68 * This function unloads a previously opened dynamically linked library
69 * using a system dependant method. No return value is taken in consideration,
70 * since some libraries sometimes refuse to close properly.
71 *****************************************************************************/
72 static void module_unload( module_handle_t handle )
75 unload_add_on( handle );
77 #elif defined(WIN32) || defined(UNDER_CE)
78 FreeLibrary( handle );
87 /*****************************************************************************
88 * module_getsymbol: get a symbol from a dynamic library
89 *****************************************************************************
90 * This function queries a loaded library for a symbol specified in a
91 * string, and returns a pointer to it. We don't check for dlerror() or
92 * similar functions, since we want a non-NULL symbol anyway.
93 *****************************************************************************/
94 static void * _module_getsymbol( module_handle_t handle,
95 const char * psz_function )
99 if( B_OK == get_image_symbol( handle, psz_function,
100 B_SYMBOL_TYPE_TEXT, &p_symbol ) )
109 #elif defined( UNDER_CE )
110 wchar_t psz_real[256];
111 MultiByteToWideChar( CP_ACP, 0, psz_function, -1, psz_real, 256 );
113 return (void *)GetProcAddress( handle, psz_real );
115 #elif defined( WIN32 )
116 return (void *)GetProcAddress( handle, (MYCHAR*)psz_function );
119 return dlsym( handle, psz_function );
124 static void * module_getsymbol( module_handle_t handle,
125 const char * psz_function )
127 void * p_symbol = _module_getsymbol( handle, psz_function );
129 /* MacOS X dl library expects symbols to begin with "_". So do
130 * some other operating systems. That's really lame, but hey, what
132 if( p_symbol == NULL )
134 char *psz_call = malloc( strlen( psz_function ) + 2 );
136 strcpy( psz_call + 1, psz_function );
138 p_symbol = _module_getsymbol( handle, psz_call );
145 /*****************************************************************************
146 * module_error: wrapper for dlerror()
147 *****************************************************************************
148 * This function returns the error message of the last module operation. It
149 * returns the string "failed" on systems which do not have a dlerror() like
150 * function. psz_buffer can be used to store temporary data, it is guaranteed
151 * to be kept intact until the return value of module_error has been used.
152 *****************************************************************************/
153 static const char * module_error( char *psz_buffer )
155 #if defined(SYS_BEOS)
158 #elif defined(UNDER_CE)
159 wchar_t psz_tmp[256];
161 int i, i_error = GetLastError();
163 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
164 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
165 (LPTSTR) psz_tmp, 256, NULL );
167 /* Go to the end of the string */
169 psz_tmp[i] && psz_tmp[i] != L'\r' && psz_tmp[i] != L'\n';
174 swprintf( psz_tmp + i, L" (error %i)", i_error );
175 psz_tmp[ 255 ] = L'\0';
178 WideCharToMultiByte( CP_ACP, WC_DEFAULTCHAR, psz_tmp, -1,
179 psz_buffer, 256, NULL, NULL );
184 int i, i_error = GetLastError();
186 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
187 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
188 (LPTSTR) psz_buffer, 256, NULL );
190 /* Go to the end of the string */
192 psz_buffer[i] && psz_buffer[i] != '\r' && psz_buffer[i] != '\n';
197 snprintf( psz_buffer + i, 256 - i, " (error %i)", i_error );
198 psz_buffer[ 255 ] = '\0';
209 /*****************************************************************************
210 * STORE_SYMBOLS: store known symbols into p_symbols for plugin access.
211 *****************************************************************************/