Use callback and opaque pointer for plugin descriptors

This is more flexible and extensible.

src/modules/bank.c

@@ -56,8 +56,6 @@ static struct
     unsigned usage;
 } modules = { VLC_STATIC_MUTEX, NULL, 0 };
 
-module_t *vlc_entry__main (void);
-
 /*****************************************************************************
  * Local prototypes
  *****************************************************************************/
@@ -467,7 +465,7 @@ static module_t *module_InitDynamic (vlc_object_t *obj,
     }
 
     /* We can now try to call the symbol */
-    module_t *module = entry ();
+    module_t *module = vlc_plugin_describe (entry);
     if (unlikely(module == NULL))
     {
         /* With a well-written module we shouldn't have to print an
@@ -497,8 +495,8 @@ error:
 static module_t *module_InitStatic (vlc_plugin_cb entry)
 {
     /* Initializes the module */
-    module_t *module = entry ();
-    if (unlikely (module == NULL))
+    module_t *module = vlc_plugin_describe (entry);
+    if (unlikely(module == NULL))
         return NULL;
 
     module->b_loaded = true;

src/modules/entry.c

@@ -145,8 +145,14 @@ static module_config_t *vlc_config_create (module_t *module, int type)
 }
 
 
-int vlc_plugin_set (module_t *module, module_config_t *item, int propid, ...)
+/**
+ * Callback for the plugin descriptor functions.
+ */
+static int vlc_plugin_setter (void *plugin, void *tgt, int propid, ...)
 {
+    module_t **pprimary = plugin;
+    module_t *module = tgt;
+    module_config_t *item = tgt;
     va_list ap;
     int ret = 0;
 
@@ -155,18 +161,20 @@ int vlc_plugin_set (module_t *module, module_config_t *item, int propid, ...)
     {
         case VLC_MODULE_CREATE:
         {
-            module_t **pp = va_arg (ap, module_t **);
+            module = *pprimary;
             module_t *submodule = vlc_module_create (module);
-
             if (unlikely(submodule == NULL))
             {
                 ret = -1;
                 break;
             }
 
-            *pp = submodule;
-            if (module == NULL)
+            *(va_arg (ap, module_t **)) = submodule;
+            if (*pprimary == NULL)
+            {
+                *pprimary = submodule;
                 break;
+            }
             /* Inheritance. Ugly!! */
             submodule->pp_shortcuts = xmalloc (sizeof (char **));
             submodule->pp_shortcuts[0] = strdup_null (module->pp_shortcuts[0]);
@@ -182,9 +190,14 @@ int vlc_plugin_set (module_t *module, module_config_t *item, int propid, ...)
         {
             int type = va_arg (ap, int);
             module_config_t **pp = va_arg (ap, module_config_t **);
-            *pp = vlc_config_create (module, type);
-            if (*pp == NULL)
+
+            item = vlc_config_create (*pprimary, type);
+            if (unlikely(item == NULL))
+            {
                 ret = -1;
+                break;
+            }
+            *pp = item;
             break;
         }
 
@@ -465,3 +478,19 @@ int vlc_plugin_set (module_t *module, module_config_t *item, int propid, ...)
     va_end (ap);
     return ret;
 }
+
+/**
+ * Runs a plug-in descriptor. This loads the plug-in meta-data in memory.
+ */
+module_t *vlc_plugin_describe (vlc_plugin_cb entry)
+{
+    module_t *module = NULL;
+
+    if (entry (vlc_plugin_setter, &module) != 0)
+    {
+        if (module != NULL) /* partially initialized plug-in... */
+            vlc_module_destroy (module);
+        module = NULL;
+    }
+    return module;
+}

src/modules/modules.h

@@ -46,7 +46,11 @@ struct module_cache_t
 /** The module handle type */
 typedef void *module_handle_t;
 
-typedef module_t *(*vlc_plugin_cb) (void);
+/** Plugin entry point prototype */
+typedef int (*vlc_plugin_cb) (int (*)(void *, void *, int, ...), void *);
+
+/** Main module */
+int vlc_entry__main (int (*)(void *, void *, int, ...), void *);
 
 /**
  * Internal module descriptor
@@ -96,6 +100,7 @@ struct module_t
     char *              domain;                            /* gettext domain */
 };
 
+module_t *vlc_plugin_describe (vlc_plugin_cb);
 module_t *vlc_module_create (module_t *);
 void vlc_module_destroy (module_t *);