degesch: add introspection for "app_context"

degesch.c

@@ -2110,6 +2110,18 @@ struct app_context
 }
 *g_ctx;
 
+static struct ispect_field g_ctx_ispect_fields[] =
+{
+	ISPECT_( app_context, global_buffer,  REF, buffer )
+	ISPECT_( app_context, current_buffer, REF, buffer )
+	{}
+};
+
+static struct ispect g_ctx_ispect =
+{
+	.fields = g_ctx_ispect_fields,
+};
+
 static int *
 filter_color_cube_for_acceptable_nick_colors (size_t *len)
 {
@@ -8570,7 +8582,9 @@ lua_weak_push (struct lua_plugin *plugin, void *object,
 	wrapper->plugin = plugin;
 	wrapper->info = info;
 	wrapper->object = object;
-	wrapper->weak_ref = info->ref (object, lua_weak_invalidate, wrapper);
+	wrapper->weak_ref = NULL;
+	if (info->ref)
+		wrapper->weak_ref = info->ref (object, lua_weak_invalidate, wrapper);
 	lua_cache_store (L, object, -1);
 }
 
@@ -8581,7 +8595,8 @@ lua_weak_gc (lua_State *L, const struct lua_weak_info *info)
 	if (wrapper->object)
 	{
 		lua_cache_invalidate (L, wrapper->object);
-		info->unref (wrapper->object, &wrapper->weak_ref);
+		if (info->unref)
+			info->unref (wrapper->object, &wrapper->weak_ref);
 		wrapper->object = NULL;
 	}
 	return 0;
@@ -8616,6 +8631,14 @@ LUA_WEAK_DECLARE (channel, XLUA_CHANNEL_METATABLE)
 LUA_WEAK_DECLARE (buffer,  XLUA_BUFFER_METATABLE)
 LUA_WEAK_DECLARE (server,  XLUA_SERVER_METATABLE)
 
+// The global context is kind of fake and don't have any ref-counting,
+// however it's still very much an object
+static struct lua_weak_info lua_ctx_info =
+{
+	.name = PROGRAM_NAME,
+	.ispect = &g_ctx_ispect,
+};
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
 static int
@@ -9730,8 +9753,18 @@ lua_plugin_connect (lua_State *L)
 	return 1;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+static int
+lua_ctx_gc (lua_State *L)
+{
+	return lua_weak_gc (L, &lua_ctx_info);
+}
+
 static luaL_Reg lua_plugin_library[] =
 {
+	// These are global functions:
+
 	{ "parse",           lua_plugin_parse           },
 	{ "hook_input",      lua_plugin_hook_input      },
 	{ "hook_irc",        lua_plugin_hook_irc        },
@@ -9739,6 +9772,10 @@ static luaL_Reg lua_plugin_library[] =
 	{ "hook_timer",      lua_plugin_hook_timer      },
 	{ "setup_config",    lua_plugin_setup_config    },
 	{ "connect",         lua_plugin_connect         },
+
+	// And these are methods:
+	{ "__gc",            lua_ctx_gc                 },
+	// TODO: get_prompt_ignore_markers()
 	{ NULL,              NULL                       },
 };
 
@@ -9908,7 +9945,6 @@ lua_plugin_reg_finish (lua_State *L, struct lua_weak_info *info)
 	lua_setfield (L, -2, "__index");
 	lua_pushcfunction (L, lua_plugin_property_set);
 	lua_setfield (L, -2, "__newindex");
-
 	lua_pop (L, 1);
 }
 
@@ -9948,12 +9984,17 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
 	plugin->ctx = ctx;
 	plugin->L = L;
 
-	// Register the degesch library with "plugin" as an upvalue
 	luaL_checkversion (L);
-	luaL_newlibtable (L, lua_plugin_library);
+
+	// Register the degesch library as a singleton with "plugin" as an upvalue
+	// (mostly historical, but rather convenient)
+	luaL_newmetatable (L, lua_ctx_info.name);
 	lua_pushlightuserdata (L, plugin);
 	luaL_setfuncs (L, lua_plugin_library, 1);
-	lua_setglobal (L, PROGRAM_NAME);
+	lua_plugin_reg_finish (L, &lua_ctx_info);
+
+	lua_weak_push (plugin, ctx, &lua_ctx_info);
+	lua_setglobal (L, lua_ctx_info.name);
 
 	// Create metatables for our objects
 	lua_plugin_reg_meta (L, XLUA_HOOK_METATABLE,       lua_hook_table);