AP_GPS: fixed build on non-PX4 platforms

libraries/AP_GPS/AP_GPS.cpp

@@ -145,20 +145,23 @@ AP_GPS::detect_instance(uint8_t instance)
     AP_GPS_Backend *new_gps = NULL;
     AP_HAL::UARTDriver *port = instance==0?hal.uartB:hal.uartE;
     struct detect_state *dstate = &detect_state[instance];
+    uint32_t now = hal.scheduler->millis();
 
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
     if (_type[instance] == GPS_TYPE_PX4) {
         // check for explicitely chosen PX4 GPS beforehand
         // it is not possible to autodetect it, nor does it require a real UART
         hal.console->print_P(PSTR(" PX4 "));
         new_gps = new AP_GPS_PX4(*this, state[instance], port);
+        goto found_gps;
     }
-    else if (port == NULL) {
+#endif
+
+    if (port == NULL) {
         // UART not available
         return;
     }
 
-    uint32_t now = hal.scheduler->millis();
-
     state[instance].instance = instance;
     state[instance].status = NO_GPS;
 
@@ -233,6 +236,7 @@ AP_GPS::detect_instance(uint8_t instance)
 #endif
 	}
 
+found_gps:
 	if (new_gps != NULL) {
         state[instance].status = NO_FIX;
         drivers[instance] = new_gps;

libraries/AP_GPS/AP_GPS_PX4.cpp

@@ -22,7 +22,10 @@
 //
 //  Code by Holger Steinhaus
 
+#include <AP_HAL.h>
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
 #include "AP_GPS_PX4.h"
+
 #include <uORB/uORB.h>
 
 #include <math.h>
@@ -75,4 +78,5 @@ AP_GPS_PX4::read(void)
     }
 
     return updated;
-}
+}
\ No newline at end of file
+#endif

libraries/AP_GPS/AP_GPS_PX4.h

@@ -23,6 +23,7 @@
 
 #include <AP_HAL.h>
 #include <AP_GPS.h>
+#if CONFIG_HAL_BOARD == HAL_BOARD_PX4
 #include <modules/uORB/topics/vehicle_gps_position.h>
 
 class AP_GPS_PX4 : public AP_GPS_Backend {
@@ -35,5 +36,6 @@ private:
     int                           _gps_sub;
     struct vehicle_gps_position_s _gps_pos;
 };
+#endif // CONFIG_HAL_BOARD
+#endif // AP_GPS_PX4_H
 
-#endif // AP_GPS_SIRF_h