AC_AutoTune: add and use header guards

libraries/AC_AutoTune/AC_AutoTune.cpp

@@ -1,3 +1,7 @@
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include "AC_AutoTune.h"
 
 #include <AP_Logger/AP_Logger.h>
@@ -757,3 +761,4 @@ void AC_AutoTune::next_tune_type(TuneType &curr_tune_type, bool reset)
     curr_tune_type = tune_seq[tune_seq_curr];
 }
 
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune.h

@@ -18,6 +18,10 @@
  */
 #pragma once
 
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include <AC_AttitudeControl/AC_AttitudeControl.h>
 #include <AC_AttitudeControl/AC_PosControl.h>
 #include <AP_Math/AP_Math.h>
@@ -327,3 +331,5 @@ private:
     uint32_t last_pilot_override_warning;
 
 };
+
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune_Heli.cpp

@@ -17,6 +17,10 @@
   Converted to a library by Andrew Tridgell, and rewritten to include helicopters by Bill Geyer
  */
 
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include "AC_AutoTune_Heli.h"
 
 #include <AP_Logger/AP_Logger.h>
@@ -1941,3 +1945,5 @@ bool AC_AutoTune_Heli::exceeded_freq_range(float frequency)
     }
     return ret;
 }
+
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune_Heli.h

@@ -18,6 +18,10 @@
 
 #pragma once
 
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include "AC_AutoTune.h"
 #include <AP_Math/chirp.h>
 #include <GCS_MAVLink/GCS.h>
@@ -296,3 +300,5 @@ private:
 
     Chirp chirp_input;
 };
+
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune_Multi.cpp

@@ -1,3 +1,7 @@
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include "AC_AutoTune_Multi.h"
 
 #include <AP_Logger/AP_Logger.h>
@@ -1246,3 +1250,5 @@ uint32_t AC_AutoTune_Multi::get_testing_step_timeout_ms() const
     return AUTOTUNE_TESTING_STEP_TIMEOUT_MS;
 }
 
+
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune_Multi.h

@@ -19,6 +19,10 @@
 
 #pragma once
 
+#include "AC_AutoTune_config.h"
+
+#if AC_AUTOTUNE_ENABLED
+
 #include "AC_AutoTune.h"
 
 class AC_AutoTune_Multi : public AC_AutoTune
@@ -168,3 +172,5 @@ private:
     AP_Float aggressiveness;      // aircraft response aggressiveness to be tuned
     AP_Float min_d;               // minimum rate d gain allowed during tuning
 };
+
+#endif  // AC_AUTOTUNE_ENABLED

libraries/AC_AutoTune/AC_AutoTune_config.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <AP_HAL/AP_HAL_Boards.h>
+
+#ifndef AC_AUTOTUNE_ENABLED
+#define AC_AUTOTUNE_ENABLED 1
+#endif