Add support for modules help strings (Closes:#413)
[vlc.git] / include / modules_inner.h
1 /*****************************************************************************
2  * modules_inner.h : Macros used from within a module.
3  *****************************************************************************
4  * Copyright (C) 2001-2006 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Samuel Hocevar <sam@zoy.org>
8  *
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.
13  *
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.
18  *
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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22  *****************************************************************************/
23
24 /*****************************************************************************
25  * If we are not within a module, assume we're in the vlc core.
26  *****************************************************************************/
27 #if !defined( __PLUGIN__ ) && !defined( __BUILTIN__ )
28 #   define MODULE_NAME main
29 #endif
30
31 /*****************************************************************************
32  * Add a few defines. You do not want to read this section. Really.
33  *****************************************************************************/
34
35 /* Explanation:
36  *
37  * if user has #defined MODULE_NAME foo, then we will need:
38  * #define MODULE_STRING "foo"
39  *
40  * and, if __BUILTIN__ is set, we will also need:
41  * #define MODULE_FUNC( zog ) module_foo_zog
42  *
43  * this can't easily be done with the C preprocessor, thus a few ugly hacks.
44  */
45
46 /* I can't believe I need to do this to change « foo » to « "foo" » */
47 #define STRINGIFY( z )   UGLY_KLUDGE( z )
48 #define UGLY_KLUDGE( z ) #z
49 /* And I need to do _this_ to change « foo bar » to « module_foo_bar » ! */
50 #define CONCATENATE( y, z ) CRUDE_HACK( y, z )
51 #define CRUDE_HACK( y, z )  y##__##z
52
53 /* If the module is built-in, then we need to define foo_InitModule instead
54  * of InitModule. Same for Activate- and DeactivateModule. */
55 #if defined( __BUILTIN__ )
56 #   define E_( function )          CONCATENATE( function, MODULE_NAME )
57 #   define __VLC_SYMBOL( symbol )  CONCATENATE( symbol, MODULE_NAME )
58 #   define DECLARE_SYMBOLS         struct _u_n_u_s_e_d_
59 #   define STORE_SYMBOLS           struct _u_n_u_s_e_d_
60 #elif defined( __PLUGIN__ )
61 #   define E_( function )          CONCATENATE( function, MODULE_SYMBOL )
62 #   define __VLC_SYMBOL( symbol  ) CONCATENATE( symbol, MODULE_SYMBOL )
63 #   define DECLARE_SYMBOLS         module_symbols_t* p_symbols
64 #   define STORE_SYMBOLS           p_symbols = p_module->p_symbols
65 #endif
66
67 #if defined( __PLUGIN__ ) && ( defined( WIN32 ) || defined( UNDER_CE ) )
68 #   define DLL_SYMBOL              __declspec(dllexport)
69 #   define CDECL_SYMBOL            __cdecl
70 #else
71 #   define DLL_SYMBOL
72 #   define CDECL_SYMBOL
73 #endif
74
75 #if defined( __cplusplus )
76 #   define EXTERN_SYMBOL           extern "C"
77 #else
78 #   define EXTERN_SYMBOL
79 #endif
80
81 #if defined( USE_DLL )
82 #   define IMPORT_SYMBOL __declspec(dllimport)
83 #else
84 #   define IMPORT_SYMBOL
85 #endif
86
87 #define MODULE_STRING STRINGIFY( MODULE_NAME )
88
89 /*
90  * InitModule: this function is called once and only once, when the module
91  * is looked at for the first time. We get the useful data from it, for
92  * instance the module name, its shortcuts, its capabilities... we also create
93  * a copy of its config because the module can be unloaded at any time.
94  */
95 #define vlc_module_begin( )                                                   \
96     DECLARE_SYMBOLS;                                                          \
97     EXTERN_SYMBOL DLL_SYMBOL int CDECL_SYMBOL                                 \
98     __VLC_SYMBOL(vlc_entry) ( module_t *p_module )                            \
99     {                                                                         \
100         int i_shortcut = 1, i_config = -1;                                    \
101         module_config_t *p_config = NULL;                                     \
102         static module_config_t config_end = {                                 \
103             CONFIG_HINT_END, NULL, NULL, 0, NULL, NULL, NULL, 0, 0., 0, 0,    \
104             0., 0., NULL, NULL, NULL, NULL, NULL, 0, NULL, NULL, 0, NULL,     \
105             VLC_FALSE, NULL, VLC_FALSE, VLC_FALSE, VLC_FALSE, VLC_FALSE,      \
106             NULL, 0, 0., NULL, 0, 0., VLC_FALSE                               \
107         };                                                                    \
108         STORE_SYMBOLS;                                                        \
109         p_module->b_submodule = VLC_FALSE;                                    \
110         p_module->b_unloadable = VLC_TRUE;                                    \
111         p_module->b_reentrant = VLC_TRUE;                                     \
112         p_module->psz_object_name = MODULE_STRING;                            \
113         p_module->psz_shortname = NULL;                                       \
114         p_module->psz_longname = MODULE_STRING;                               \
115         p_module->psz_help = NULL;                                            \
116         p_module->pp_shortcuts[ 0 ] = MODULE_STRING;                          \
117         p_module->i_cpu = 0;                                                  \
118         p_module->psz_program = NULL;                                         \
119         p_module->psz_capability = "";                                        \
120         p_module->i_score = 1;                                                \
121         p_module->pf_activate = NULL;                                         \
122         p_module->pf_deactivate = NULL;                                       \
123         {                                                                     \
124             module_t *p_submodule = p_module /* the ; gets added */
125
126 #define vlc_module_end( )                                                     \
127             p_submodule->pp_shortcuts[ i_shortcut ] = NULL;                   \
128         }                                                                     \
129         if( p_config )                                                        \
130         {                                                                     \
131             int i;                                                            \
132             p_config[ ++i_config ] = config_end;                              \
133             config_Duplicate( p_module, p_config );                           \
134             for( i = 0; i < i_config; i++ )                                   \
135             {                                                                 \
136                 if( p_config[ i ].i_action )                                  \
137                 {                                                             \
138                     free( p_config[ i ].ppf_action );                         \
139                     free( p_config[ i ].ppsz_action_text );                   \
140                 }                                                             \
141             }                                                                 \
142             free( p_config );                                                 \
143         }                                                                     \
144         else config_Duplicate( p_module, &config_end );                       \
145         if( p_module->p_config == NULL )                                      \
146         {                                                                     \
147             return VLC_EGENERIC;                                              \
148         }                                                                     \
149         return VLC_SUCCESS && i_shortcut;                                     \
150     }                                                                         \
151     struct _u_n_u_s_e_d_ /* the ; gets added */
152
153
154 #define add_submodule( )                                                      \
155     p_submodule->pp_shortcuts[ i_shortcut ] = NULL;                           \
156     p_submodule =                                                             \
157             (module_t *)vlc_object_create( p_module, VLC_OBJECT_MODULE );     \
158     vlc_object_attach( p_submodule, p_module );                               \
159     p_submodule->b_submodule = VLC_TRUE;                                      \
160     /* Nuahahaha! Heritage! Polymorphism! Ugliness!! */                       \
161     for( i_shortcut = 0; p_module->pp_shortcuts[ i_shortcut ]; i_shortcut++ ) \
162     {                                                                         \
163         p_submodule->pp_shortcuts[ i_shortcut ] =                             \
164                                 p_module->pp_shortcuts[ i_shortcut ];         \
165     }                                                                         \
166     p_submodule->psz_object_name = p_module->psz_object_name;                 \
167     p_submodule->psz_shortname = p_module->psz_shortname;                     \
168     p_submodule->psz_longname = p_module->psz_longname;                       \
169     p_submodule->psz_program = p_module->psz_program;                         \
170     p_submodule->psz_capability = p_module->psz_capability;                   \
171     p_submodule->i_score = p_module->i_score;                                 \
172     p_submodule->i_cpu = p_module->i_cpu;                                     \
173     p_submodule->pf_activate = NULL;                                          \
174     p_submodule->pf_deactivate = NULL
175
176 #define add_requirement( cap )                                                \
177     p_module->i_cpu |= CPU_CAPABILITY_##cap
178
179 #define add_shortcut( shortcut )                                              \
180     p_submodule->pp_shortcuts[ i_shortcut ] = shortcut;                       \
181     i_shortcut++
182
183 #define set_shortname( desc )                                                 \
184     p_submodule->psz_shortname = desc
185
186 #define set_description( desc )                                               \
187     p_submodule->psz_longname = desc
188
189 #define set_help( help )                                                      \
190     p_submodule->psz_help = help
191
192 #define set_capability( cap, score )                                          \
193     p_submodule->psz_capability = cap;                                        \
194     p_submodule->i_score = score
195
196 #define set_program( program )                                                \
197     p_submodule->psz_program = program
198
199 #define set_callbacks( activate, deactivate )                                 \
200     p_submodule->pf_activate = activate;                                      \
201     p_submodule->pf_deactivate = deactivate
202
203 #define linked_with_a_crap_library_which_uses_atexit( )                       \
204     p_module->b_unloadable = VLC_FALSE
205