AP_HAL_SITL: add override keyword where required

libraries/AP_HAL_SITL/RCOutput.h

@@ -15,8 +15,8 @@ public:
     void write(uint8_t ch, uint16_t period_us) override;
     uint16_t read(uint8_t ch) override;
     void read(uint16_t* period_us, uint8_t len) override;
-    void cork(void);
-    void push(void);
+    void cork(void) override;
+    void push(void) override;
 
 private:
     SITL_State *_sitlState;

libraries/AP_HAL_SITL/Scheduler.h

@@ -18,19 +18,19 @@ public:
 
     /* AP_HAL::Scheduler methods */
 
-    void init();
-    void delay(uint16_t ms);
-    void delay_microseconds(uint16_t us);
+    void init() override;
+    void delay(uint16_t ms) override;
+    void delay_microseconds(uint16_t us) override;
 
-    void register_timer_process(AP_HAL::MemberProc);
-    void register_io_process(AP_HAL::MemberProc);
+    void register_timer_process(AP_HAL::MemberProc) override;
+    void register_io_process(AP_HAL::MemberProc) override;
 
-    void register_timer_failsafe(AP_HAL::Proc, uint32_t period_us);
+    void register_timer_failsafe(AP_HAL::Proc, uint32_t period_us) override;
 
     bool in_main_thread() const override;
-    void system_initialized();
+    void system_initialized() override;
 
-    void reboot(bool hold_in_bootloader);
+    void reboot(bool hold_in_bootloader) override;
 
     bool interrupts_are_blocked(void) {
         return _nested_atomic_ctr != 0;
@@ -72,7 +72,7 @@ private:
     static bool _in_timer_proc;
     static bool _in_io_proc;
 
-    void stop_clock(uint64_t time_usec);
+    void stop_clock(uint64_t time_usec) override;
 
     static void *thread_create_trampoline(void *ctx);
     static void check_thread_stacks(void);

libraries/AP_HAL_SITL/UARTDriver.h

@@ -26,22 +26,22 @@ public:
     }
     
     /* Implementations of UARTDriver virtual methods */
-    void begin(uint32_t b) {
+    void begin(uint32_t b) override {
         begin(b, 0, 0);
     }
-    void begin(uint32_t b, uint16_t rxS, uint16_t txS);
-    void end();
-    void flush();
-    bool is_initialized() {
+    void begin(uint32_t b, uint16_t rxS, uint16_t txS) override;
+    void end() override;
+    void flush() override;
+    bool is_initialized() override {
         return true;
     }
 
-    void set_blocking_writes(bool blocking)
+    void set_blocking_writes(bool blocking) override
     {
         _nonblocking_writes = !blocking;
     }
 
-    bool tx_pending() {
+    bool tx_pending() override {
         return false;
     }
 
@@ -51,21 +51,21 @@ public:
     int16_t read() override;
 
     /* Implementations of Print virtual methods */
-    size_t write(uint8_t c);
-    size_t write(const uint8_t *buffer, size_t size);
+    size_t write(uint8_t c) override;
+    size_t write(const uint8_t *buffer, size_t size) override;
 
     // file descriptor, exposed so SITL_State::loop_hook() can use it
     int _fd;
 
     bool _unbuffered_writes;
 
-    enum flow_control get_flow_control(void) { return FLOW_CONTROL_ENABLE; }
+    enum flow_control get_flow_control(void) override { return FLOW_CONTROL_ENABLE; }
 
     void configure_parity(uint8_t v) override;
     void set_stop_bits(int n) override;
     bool set_unbuffered_writes(bool on) override;
 
-    void _timer_tick(void);
+    void _timer_tick(void) override;
 
     /*
       return timestamp estimate in microseconds for when the start of

libraries/AP_HAL_SITL/Util.h

@@ -10,7 +10,7 @@ public:
     Util(SITL_State *_sitlState) :
         sitlState(_sitlState) {}
     
-    bool run_debug_shell(AP_HAL::BetterStream *stream) {
+    bool run_debug_shell(AP_HAL::BetterStream *stream) override {
         return false;
     }