Initial work on hiding module_t layout from plugins
[vlc.git] / include / vlc_modules_macros.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 #if !defined( __LIBVLC__ )
25   #error You are not libvlc or one of its plugins. You cannot include this file
26 #endif
27
28 /*****************************************************************************
29  * If we are not within a module, assume we're in the vlc core.
30  *****************************************************************************/
31 #if !defined( __PLUGIN__ ) && !defined( __BUILTIN__ )
32 #   define MODULE_NAME main
33 #endif
34
35 /*****************************************************************************
36  * Add a few defines. You do not want to read this section. Really.
37  *****************************************************************************/
38
39 /* Explanation:
40  *
41  * if user has #defined MODULE_NAME foo, then we will need:
42  * #define MODULE_STRING "foo"
43  *
44  * and, if __BUILTIN__ is set, we will also need:
45  * #define MODULE_FUNC( zog ) module_foo_zog
46  *
47  * this can't easily be done with the C preprocessor, thus a few ugly hacks.
48  */
49
50 /* I can't believe I need to do this to change « foo » to « "foo" » */
51 #define STRINGIFY( z )   UGLY_KLUDGE( z )
52 #define UGLY_KLUDGE( z ) #z
53 /* And I need to do _this_ to change « foo bar » to « module_foo_bar » ! */
54 #define CONCATENATE( y, z ) CRUDE_HACK( y, z )
55 #define CRUDE_HACK( y, z )  y##__##z
56
57 /* If the module is built-in, then we need to define foo_InitModule instead
58  * of InitModule. Same for Activate- and DeactivateModule. */
59 #if defined( __BUILTIN__ )
60 #   define E_( function )          CONCATENATE( function, MODULE_NAME )
61 #   define __VLC_SYMBOL( symbol )  CONCATENATE( symbol, MODULE_NAME )
62 #   define DECLARE_SYMBOLS         struct _u_n_u_s_e_d_
63 #   define STORE_SYMBOLS           struct _u_n_u_s_e_d_
64 #elif defined( __PLUGIN__ )
65 #   define E_( function )          CONCATENATE( function, MODULE_SYMBOL )
66 #   define __VLC_SYMBOL( symbol  ) CONCATENATE( symbol, MODULE_SYMBOL )
67 #   define DECLARE_SYMBOLS         module_symbols_t* p_symbols
68 #   define STORE_SYMBOLS           p_symbols = p_module->p_symbols
69 #endif
70
71 #if defined( __PLUGIN__ ) && ( defined( WIN32 ) || defined( UNDER_CE ) )
72 #   define DLL_SYMBOL              __declspec(dllexport)
73 #   define CDECL_SYMBOL            __cdecl
74 #elif HAVE_ATTRIBUTE_VISIBILITY
75 #   define DLL_SYMBOL __attribute__((visibility("default")))
76 #   define CDECL_SYMBOL
77 #else
78 #   define DLL_SYMBOL
79 #   define CDECL_SYMBOL
80 #endif
81
82 #if defined( __cplusplus )
83 #   define EXTERN_SYMBOL           extern "C"
84 #else
85 #   define EXTERN_SYMBOL
86 #endif
87
88 #if defined( USE_DLL )
89 #   define IMPORT_SYMBOL __declspec(dllimport)
90 #else
91 #   define IMPORT_SYMBOL
92 #endif
93
94 #define MODULE_STRING STRINGIFY( MODULE_NAME )
95
96 /*
97  * InitModule: this function is called once and only once, when the module
98  * is looked at for the first time. We get the useful data from it, for
99  * instance the module name, its shortcuts, its capabilities... we also create
100  * a copy of its config because the module can be unloaded at any time.
101  */
102 #if defined (__PLUGIN__) || defined (__BUILTIN__)
103 EXTERN_SYMBOL DLL_SYMBOL int CDECL_SYMBOL
104 E_(vlc_entry) ( module_t *p_module );
105 #endif
106
107 #define vlc_module_begin( )                                                   \
108     DECLARE_SYMBOLS;                                                          \
109     EXTERN_SYMBOL DLL_SYMBOL int CDECL_SYMBOL                                 \
110     __VLC_SYMBOL(vlc_entry) ( module_t *p_module )                            \
111     {                                                                         \
112         int i_shortcut = 1, res;                                              \
113         size_t i_config = (size_t)(-1);                                       \
114         module_config_t *p_config = NULL;                                     \
115         STORE_SYMBOLS;                                                        \
116         p_module->b_submodule = VLC_FALSE;                                    \
117         p_module->b_unloadable = VLC_TRUE;                                    \
118         p_module->b_reentrant = VLC_TRUE;                                     \
119         p_module->psz_object_name = MODULE_STRING;                            \
120         p_module->psz_shortname = NULL;                                       \
121         p_module->psz_longname = MODULE_STRING;                               \
122         p_module->psz_help = NULL;                                            \
123         p_module->pp_shortcuts[ 0 ] = MODULE_STRING;                          \
124         for( unsigned i = 1; i < MODULE_SHORTCUT_MAX; i++ )                   \
125             p_module->pp_shortcuts[i] = NULL;                                 \
126         p_module->i_cpu = 0;                                                  \
127         p_module->psz_program = NULL;                                         \
128         p_module->psz_capability = "";                                        \
129         p_module->i_score = 1;                                                \
130         p_module->pf_activate = NULL;                                         \
131         p_module->pf_deactivate = NULL;                                       \
132         {                                                                     \
133             module_t *p_submodule = p_module /* the ; gets added */
134
135 #define vlc_module_end( )                                                     \
136             p_submodule->pp_shortcuts[ i_shortcut ] = NULL;                   \
137         }                                                                     \
138         res = config_Duplicate( p_module, p_config, ++i_config );             \
139         for( size_t i = 0; i < i_config; i++ )                                \
140         {                                                                     \
141             if( p_config[ i ].i_action )                                      \
142             {                                                                 \
143                 free( p_config[ i ].ppf_action );                             \
144                 free( p_config[ i ].ppsz_action_text );                       \
145             }                                                                 \
146         }                                                                     \
147         free( p_config );                                                     \
148         if (res)                                                              \
149             return res;                                                       \
150         (void)i_shortcut;                                                     \
151         return VLC_SUCCESS;                                                   \
152     }                                                                         \
153     struct _u_n_u_s_e_d_ /* the ; gets added */
154
155
156 #define add_submodule( ) \
157     p_submodule = vlc_submodule_create( p_module )
158
159 #define add_requirement( cap ) \
160     vlc_module_set (p_module, VLC_MODULE_CPU_REQUIREMENT, \
161                     (void *)(CPU_CAPABILITY_##cap))
162
163 #define add_shortcut( shortcut ) \
164     vlc_module_set (p_submodule, VLC_MODULE_SHORTCUT, (void*)(shortcut))
165
166 #define set_shortname( shortname ) \
167     vlc_module_set (p_submodule, VLC_MODULE_SHORTNAME, (void*)(shortname))
168
169 #define set_description( desc ) \
170     vlc_module_set (p_submodule, VLC_MODULE_DESCRIPTION, (void*)(desc))
171
172 #define set_help( help ) \
173     vlc_module_set (p_submodule, VLC_MODULE_HELP, (void*)(help))
174
175 #define set_capability( cap, score ) \
176     vlc_module_set (p_submodule, VLC_MODULE_CAPABILITY, (void *)(cap)); \
177     vlc_module_set (p_submodule, VLC_MODULE_SCORE, (void *)(score))
178
179 #define set_program( program ) \
180     vlc_module_set (p_submodule, VLC_MODULE_PROGRAM, (void *)(program))
181
182 #define set_callbacks( activate, deactivate ) \
183     vlc_module_set (p_submodule, VLC_MODULE_CB_OPEN, (void *)(activate)); \
184     vlc_module_set (p_submodule, VLC_MODULE_CB_CLOSE, (void *)(deactivate))
185
186 #define linked_with_a_crap_library_which_uses_atexit( ) \
187     vlc_module_set (p_submodule, VLC_MODULE_UNLOADABLE, NULL)
188