AP_Compass: add and use AP_SIM_COMPASS_ENABLED

libraries/AP_Compass/AP_Compass.cpp

@@ -1227,7 +1227,7 @@ void Compass::_detect_backends(void)
     }
 #endif
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
+#if AP_SIM_COMPASS_ENABLED
     ADD_BACKEND(DRIVER_SITL, new AP_Compass_SITL());
 #endif
 

libraries/AP_Compass/AP_Compass.h

@@ -70,6 +70,10 @@
 
 #define MAX_CONNECTED_MAGS (COMPASS_MAX_UNREG_DEV+COMPASS_MAX_INSTANCES)
 
+#ifndef AP_SIM_COMPASS_ENABLED
+#define AP_SIM_COMPASS_ENABLED (CONFIG_HAL_BOARD == HAL_BOARD_SITL)
+#endif
+
 #include "CompassCalibrator.h"
 
 class CompassLearn;

libraries/AP_Compass/AP_Compass_SITL.cpp

@@ -1,8 +1,9 @@
 #include "AP_Compass_SITL.h"
 
+#if AP_SIM_COMPASS_ENABLED
+
 #include <AP_HAL/AP_HAL.h>
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
 extern const AP_HAL::HAL& hal;
 
 AP_Compass_SITL::AP_Compass_SITL()
@@ -158,4 +159,4 @@ void AP_Compass_SITL::read()
         drain_accumulated_samples(_compass_instance[i], nullptr);
     }
 }
-#endif
+#endif  // AP_SIM_COMPASS_ENABLED

libraries/AP_Compass/AP_Compass_SITL.h

@@ -1,13 +1,15 @@
 #pragma once
 
 #include "AP_Compass.h"
+
+#if AP_SIM_COMPASS_ENABLED
+
 #include "AP_Compass_Backend.h"
 
-#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
-#include <SITL/SITL.h>
 #include <AP_Math/vectorN.h>
 #include <AP_Math/AP_Math.h>
 #include <AP_Declination/AP_Declination.h>
+#include <SITL/SITL.h>
 
 #define MAX_SITL_COMPASSES 3
 
@@ -42,4 +44,4 @@ private:
     Vector3f _last_odi;
     Vector3f _last_data[MAX_SITL_COMPASSES];
 };
-#endif // CONFIG_HAL_BOARD
+#endif // AP_SIM_COMPASS_ENABLED