orb macros: cleanup some unused code (#4576)

msg/mission.msg

@@ -2,6 +2,4 @@ int32 dataman_id	# default 0, there are two offboard storage places in the datam
 uint32 count		# count of the missions stored in the dataman
 int32 current_seq	# default -1, start at the one changed latest
 
-# fixme: there is no mission definition in objects_common.cpp
-# but it's required for systemcmds/topic_listener/topic_listener
 # TOPICS mission offboard_mission onboard_mission

src/drivers/drv_orb_dev.h

@@ -45,9 +45,6 @@
 #include <sys/ioctl.h>
 #include <stdint.h>
 
-/* XXX for ORB_DECLARE used in many drivers */
-#include "../modules/uORB/uORB.h"
-
 /*
  * ioctl() definitions
  */

src/modules/navigator/navigation.h

@@ -119,8 +119,5 @@ struct mission_item_s {
  * @}
  */
 
-/* register this as object request broker structure */
-ORB_DECLARE(offboard_mission);
-ORB_DECLARE(onboard_mission);
 
 #endif

src/modules/uORB/uORB.h

@@ -89,16 +89,14 @@ enum ORB_PRIO {
 #define ORB_ID(_name)		&__orb_##_name
 
 /**
- * Declare (prototype) the uORB metadata for a topic.
+ * Declare (prototype) the uORB metadata for a topic (used by code generators).
  *
  * @param _name		The name of the topic.
  */
 #if defined(__cplusplus)
 # define ORB_DECLARE(_name)		extern "C" const struct orb_metadata __orb_##_name __EXPORT
-# define ORB_DECLARE_OPTIONAL(_name)	extern "C" const struct orb_metadata __orb_##_name __EXPORT
 #else
 # define ORB_DECLARE(_name)		extern const struct orb_metadata __orb_##_name __EXPORT
-# define ORB_DECLARE_OPTIONAL(_name)	extern const struct orb_metadata __orb_##_name __EXPORT
 #endif
 
 /**

src/modules/uORB/uORBManager.hpp

@@ -187,9 +187,6 @@ public:
 	 *      for the topic.
 	 * @return    ERROR on error, otherwise returns a handle
 	 *      that can be used to read and update the topic.
-	 *      If the topic in question is not known (due to an
-	 *      ORB_DEFINE_OPTIONAL with no corresponding ORB_DECLARE)
-	 *      this function will return -1 and set errno to ENOENT.
 	 */
 	int  orb_subscribe(const struct orb_metadata *meta) ;