git.sesse.net Git - vlc/blob - include/modules_inner.h

   1 /*****************************************************************************
   2  * modules_inner.h : Macros used from within a module.
   3  *****************************************************************************
   4  * Copyright (C) 2001 VideoLAN
   5  * $Id: modules_inner.h,v 1.29 2002/08/08 22:28:22 sam Exp $
   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., 59 Temple Place - Suite 330, Boston, MA  02111, 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 #   define MODULE_PATH main
  30 #endif
  31
  32 /*****************************************************************************
  33  * Add a few defines. You do not want to read this section. Really.
  34  *****************************************************************************/
  35
  36 /* Explanation:
  37  *
  38  * if user has #defined MODULE_NAME foo, then we will need:
  39  * #define MODULE_STRING "foo"
  40  *
  41  * and, if __BUILTIN__ is set, we will also need:
  42  * #define MODULE_FUNC( zog ) module_foo_zog
  43  *
  44  * this can't easily be done with the C preprocessor, thus a few ugly hacks.
  45  */
  46
  47 /* I can't believe I need to do this to change « foo » to « "foo" » */
  48 #define STRINGIFY( z )   UGLY_KLUDGE( z )
  49 #define UGLY_KLUDGE( z ) #z
  50 /* And I need to do _this_ to change « foo bar » to « module_foo_bar » ! */
  51 #define CONCATENATE( y, z ) CRUDE_HACK( y, z )
  52 #define CRUDE_HACK( y, z )  y##__##z
  53
  54 /* If the module is built-in, then we need to define foo_InitModule instead
  55  * of InitModule. Same for Activate- and DeactivateModule. */
  56 #if defined( __BUILTIN__ )
  57 #   define E_( function )          CONCATENATE( function, MODULE_PATH )
  58 #   define __VLC_SYMBOL( symbol )  CONCATENATE( symbol, MODULE_PATH )
  59 #   define DECLARE_SYMBOLS         struct _u_n_u_s_e_d_
  60 #   define STORE_SYMBOLS           struct _u_n_u_s_e_d_
  61 #elif defined( __PLUGIN__ )
  62 #   define E_( function )          function
  63 #   define __VLC_SYMBOL( symbol  ) CONCATENATE( symbol, MODULE_SYMBOL )
  64 #   define DECLARE_SYMBOLS         module_symbols_t* p_symbols
  65 #   define STORE_SYMBOLS           p_symbols = p_module->p_symbols
  66 #endif
  67
  68 #if defined( __cplusplus )
  69 #   define EXTERN_SYMBOL           extern "C"
  70 #else
  71 #   define EXTERN_SYMBOL
  72 #endif
  73
  74 #define MODULE_STRING STRINGIFY( MODULE_NAME )
  75
  76 /*
  77  * InitModule: this function is called once and only once, when the module
  78  * is looked at for the first time. We get the useful data from it, for
  79  * instance the module name, its shortcuts, its capabilities... we also create
  80  * a copy of its config because the module can be unloaded at any time.
  81  */
  82 #define vlc_module_begin( )                                                   \
  83     DECLARE_SYMBOLS;                                                          \
  84     EXTERN_SYMBOL int __VLC_SYMBOL(vlc_entry) ( module_t *p_module )          \
  85     {                                                                         \
  86         int i_shortcut = 1, i_config = 0;                                     \
  87         module_config_t p_config[ 100 ];                                      \
  88         STORE_SYMBOLS;                                                        \
  89         p_module->b_submodule = VLC_FALSE;                                    \
  90         p_module->psz_object_name = MODULE_STRING;                            \
  91         p_module->psz_longname = MODULE_STRING;                               \
  92         p_module->pp_shortcuts[ 0 ] = MODULE_STRING;                          \
  93         p_module->i_cpu = 0;                                                  \
  94         p_module->psz_program = NULL;                                         \
  95         p_module->psz_capability = "";                                        \
  96         p_module->i_score = 1;                                                \
  97         p_module->pf_activate = NULL;                                         \
  98         p_module->pf_deactivate = NULL;                                       \
  99         {                                                                     \
 100             module_t *p_submodule = p_module /* the ; gets added */
 101
 102 #define vlc_module_end( )                                                     \
 103             p_submodule->pp_shortcuts[ i_shortcut ] = NULL;                   \
 104         }                                                                     \
 105         {                                                                     \
 106             module_config_t tmp = { CONFIG_HINT_END, NULL, NULL, '\0' };      \
 107             p_config[ i_config ] = tmp;                                       \
 108         }                                                                     \
 109         config_Duplicate( p_module, p_config );                               \
 110         if( p_module->p_config == NULL )                                      \
 111         {                                                                     \
 112             return -1;                                                        \
 113         }                                                                     \
 114         return 0 && i_shortcut;                                               \
 115     }                                                                         \
 116     int __VLC_SYMBOL(vlc_entry) ( module_t * ) /* the ; gets added */
 117
 118
 119 #define add_submodule( )                                                      \
 120     p_submodule->pp_shortcuts[ i_shortcut ] = NULL;                           \
 121     p_submodule =                                                             \
 122             (module_t *)vlc_object_create( p_module, VLC_OBJECT_MODULE );     \
 123     vlc_object_attach( p_submodule, p_module );                               \
 124     p_submodule->b_submodule = VLC_TRUE;                                      \
 125     /* Nuahahaha! Heritage! Polymorphism! Ugliness!! */                       \
 126     for( i_shortcut = 0; p_module->pp_shortcuts[ i_shortcut ]; i_shortcut++ ) \
 127     {                                                                         \
 128         p_submodule->pp_shortcuts[ i_shortcut ] =                             \
 129                                 p_module->pp_shortcuts[ i_shortcut ];         \
 130     }                                                                         \
 131     p_submodule->psz_object_name = p_module->psz_object_name;                 \
 132     p_submodule->psz_program = p_module->psz_program;                         \
 133     p_submodule->psz_capability = p_module->psz_capability;                   \
 134     p_submodule->i_score = p_module->i_score;                                 \
 135     p_submodule->i_cpu = p_module->i_cpu;                                     \
 136     p_submodule->pf_activate = NULL;                                          \
 137     p_submodule->pf_deactivate = NULL
 138
 139 #define add_requirement( cap )                                                \
 140     p_module->i_cpu |= CPU_CAPABILITY_##cap
 141
 142 #define add_shortcut( shortcut )                                              \
 143     p_submodule->pp_shortcuts[ i_shortcut ] = shortcut;                       \
 144     i_shortcut++
 145
 146 #define set_description( desc )                                               \
 147     p_module->psz_longname = desc
 148
 149 #define set_capability( cap, score )                                          \
 150     p_submodule->psz_capability = cap;                                        \
 151     p_submodule->i_score = score
 152
 153 #define set_program( program )                                                \
 154     p_submodule->psz_program = program
 155
 156 #define set_callbacks( activate, deactivate )                                 \
 157     p_submodule->pf_activate = activate;                                      \
 158     p_submodule->pf_deactivate = deactivate
 159
 160 /*
 161  * module_activate: this function is called before functions can be accessed,
 162  * we do allocation tasks here, and maybe additional stuff such as large
 163  * table allocation. Once ActivateModule is called we are almost sure the
 164  * module will be used.
 165  */
 166 #define module_activate( prototype )                                          \
 167     __module_activate( prototype );                                           \
 168     int __VLC_SYMBOL( module_activate ) ( module_t *p_module )                \
 169     {                                                                         \
 170         STORE_SYMBOLS;                                                        \
 171         config_SetCallbacks( p_module->p_config, p_config );                  \
 172         return __module_activate( p_module );                                 \
 173     }                                                                         \
 174                                                                               \
 175     static int __module_activate( prototype )
 176
 177 /*
 178  * DeactivateModule: this function is called after we are finished with the
 179  * module. Everything that has been done in ActivateModule needs to be undone
 180  * here.
 181  */
 182 #define module_deactivate( prototype )                                        \
 183     __module_deactivate( prototype );                                         \
 184     int __VLC_SYMBOL( module_deactivate )( module_t *p_module )               \
 185     {                                                                         \
 186         int i_ret = __module_deactivate( p_module );                          \
 187         config_UnsetCallbacks( p_module->p_config );                          \
 188         return i_ret;                                                         \
 189     }                                                                         \
 190                                                                               \
 191     static int __module_deactivate( prototype )
 192