APMRover2: const correctness

APMrover2/APMrover2.cpp

@@ -119,7 +119,7 @@ void Rover::loop()
     // wait for an INS sample
     ins.wait_for_sample();
 
-    uint32_t timer = AP_HAL::micros();
+    const uint32_t timer = AP_HAL::micros();
 
     delta_us_fast_loop  = timer - fast_loopTimer_us;
     G_Dt                = delta_us_fast_loop * 1.0e-6f;
@@ -405,7 +405,7 @@ void Rover::update_GPS_10Hz(void)
                 init_home();
 
                 // set system clock for log timestamps
-                uint64_t gps_timestamp = gps.time_epoch_usec();
+                const uint64_t gps_timestamp = gps.time_epoch_usec();
 
                 hal.util->set_system_clock(gps_timestamp);
 

APMrover2/GCS_Mavlink.cpp

@@ -7,7 +7,7 @@ void Rover::send_heartbeat(mavlink_channel_t chan)
 {
     uint8_t base_mode = MAV_MODE_FLAG_CUSTOM_MODE_ENABLED;
     uint8_t system_status = MAV_STATE_ACTIVE;
-    uint32_t custom_mode = control_mode;
+    const uint32_t custom_mode = control_mode;
 
     if (failsafe.triggered != 0) {
         system_status = MAV_STATE_CRITICAL;
@@ -71,7 +71,7 @@ void Rover::send_heartbeat(mavlink_channel_t chan)
 
 void Rover::send_attitude(mavlink_channel_t chan)
 {
-    Vector3f omega = ahrs.get_gyro();
+    const Vector3f omega = ahrs.get_gyro();
     mavlink_msg_attitude_send(
         chan,
         millis(),
@@ -1498,7 +1498,7 @@ void Rover::mavlink_delay_cb()
 
     in_mavlink_delay = true;
 
-    uint32_t tnow = millis();
+    const uint32_t tnow = millis();
     if (tnow - last_1hz > 1000) {
         last_1hz = tnow;
         gcs_send_message(MSG_HEARTBEAT);

APMrover2/Log.cpp

@@ -93,15 +93,13 @@ int8_t Rover::erase_logs(uint8_t argc, const Menu::arg *argv)
 
 int8_t Rover::select_logs(uint8_t argc, const Menu::arg *argv)
 {
-    uint16_t bits;
+    uint16_t bits = 0;
 
     if (argc != 2) {
         cliSerial->printf("missing log type\n");
         return(-1);
     }
 
-    bits = 0;
-
     // Macro to make the following code a bit easier on the eye.
     // Pass it the capitalised name of the log option, as defined
     // in defines.h but without the LOG_ prefix.  It will check for
@@ -236,7 +234,7 @@ struct PACKED log_Control_Tuning {
 // Write a control tuning packet. Total length : 22 bytes
 void Rover::Log_Write_Control_Tuning()
 {
-    Vector3f accel = ins.get_accel();
+    const Vector3f accel = ins.get_accel();
     struct log_Control_Tuning pkt = {
         LOG_PACKET_HEADER_INIT(LOG_CTUN_MSG),
         time_us         : AP_HAL::micros64(),
@@ -279,7 +277,7 @@ void Rover::Log_Write_Nav_Tuning()
 // Write an attitude packet
 void Rover::Log_Write_Attitude()
 {
-    Vector3f targets(0.0f, 0.0f, 0.0f);  // Rover does not have attitude targets, use place-holder for commonality with Dataflash Log_Write_Attitude message
+    const Vector3f targets(0.0f, 0.0f, 0.0f);  // Rover does not have attitude targets, use place-holder for commonality with Dataflash Log_Write_Attitude message
 
     DataFlash.Log_Write_Attitude(ahrs, targets);
 

APMrover2/Parameters.cpp

@@ -599,7 +599,7 @@ void Rover::load_parameters(void)
         cliSerial->printf("done.\n");
     }
 
-    uint32_t before = micros();
+    const uint32_t before = micros();
     // Load all auto-loaded EEPROM variables
     AP_Param::load_all();
 

APMrover2/Steering.cpp

@@ -54,7 +54,7 @@ bool Rover::auto_check_trigger(void) {
     }
 
     if (!is_zero(g.auto_kickstart)) {
-        float xaccel = ins.get_accel().x;
+        const float xaccel = ins.get_accel().x;
         if (xaccel >= g.auto_kickstart) {
             gcs_send_text_fmt(MAV_SEVERITY_WARNING, "Triggered AUTO xaccel=%.1f", static_cast<double>(xaccel));
             auto_triggered = true;
@@ -70,7 +70,7 @@ bool Rover::auto_check_trigger(void) {
 */
 bool Rover::use_pivot_steering(void) {
     if (control_mode >= AUTO && g.skid_steer_out && g.pivot_turn_angle != 0) {
-        int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
+        const int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
         if (abs(bearing_error) > g.pivot_turn_angle) {
             return true;
         }
@@ -111,8 +111,8 @@ void Rover::calc_throttle(float target_speed) {
         return;
     }
 
-    float throttle_base = (fabsf(target_speed) / g.speed_cruise) * g.throttle_cruise;
+    const float throttle_base = (fabsf(target_speed) / g.speed_cruise) * g.throttle_cruise;
-    int throttle_target = throttle_base + throttle_nudge;
+    const int throttle_target = throttle_base + throttle_nudge;
 
     /*
         reduce target speed in proportion to turning rate, up to the
@@ -123,15 +123,15 @@ void Rover::calc_throttle(float target_speed) {
 
     // use g.speed_turn_gain for a 90 degree turn, and in proportion
     // for other turn angles
-    int32_t turn_angle = wrap_180_cd(next_navigation_leg_cd - ahrs.yaw_sensor);
+    const int32_t turn_angle = wrap_180_cd(next_navigation_leg_cd - ahrs.yaw_sensor);
-    float speed_turn_ratio = constrain_float(fabsf(turn_angle / 9000.0f), 0, 1);
+    const float speed_turn_ratio = constrain_float(fabsf(turn_angle / 9000.0f), 0, 1);
-    float speed_turn_reduction = (100 - g.speed_turn_gain) * speed_turn_ratio * 0.01f;
+    const float speed_turn_reduction = (100 - g.speed_turn_gain) * speed_turn_ratio * 0.01f;
 
     float reduction = 1.0f - steer_rate * speed_turn_reduction;
 
     if (control_mode >= AUTO && wp_distance <= g.speed_turn_dist) {
         // in auto-modes we reduce speed when approaching waypoints
-        float reduction2 = 1.0f - speed_turn_reduction;
+        const float reduction2 = 1.0f - speed_turn_reduction;
         if (reduction2 < reduction) {
             reduction = reduction2;
         }
@@ -162,8 +162,8 @@ void Rover::calc_throttle(float target_speed) {
         // We use a linear gain, with 0 gain at a ground speed error
         // of braking_speederr, and 100% gain when groundspeed_error
         // is 2*braking_speederr
-        float brake_gain = constrain_float(((-groundspeed_error)-g.braking_speederr)/g.braking_speederr, 0, 1);
+        const float brake_gain = constrain_float(((-groundspeed_error)-g.braking_speederr)/g.braking_speederr, 0, 1);
-        int16_t braking_throttle = g.throttle_max * (g.braking_percent * 0.01f) * brake_gain;
+        const int16_t braking_throttle = g.throttle_max * (g.braking_percent * 0.01f) * brake_gain;
         SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, constrain_int16(-braking_throttle, -g.throttle_max, -g.throttle_min));
 
         // temporarily set us in reverse to allow the PWM setting to
@@ -207,7 +207,7 @@ void Rover::calc_lateral_acceleration() {
     // positive error = right turn
     lateral_acceleration = nav_controller->lateral_acceleration();
     if (use_pivot_steering()) {
-        int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
+        const int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
         if (bearing_error > 0) {
             lateral_acceleration = g.turn_max_g * GRAVITY_MSS;
         } else {

APMrover2/commands_logic.cpp

@@ -137,7 +137,7 @@ void Rover::exit_mission()
 bool Rover::verify_command_callback(const AP_Mission::Mission_Command& cmd)
 {
     if (control_mode == AUTO) {
-        bool cmd_complete = verify_command(cmd);
+        const bool cmd_complete = verify_command(cmd);
 
         // send message to GCS
         if (cmd_complete) {
@@ -304,7 +304,7 @@ bool Rover::verify_nav_wp(const AP_Mission::Mission_Command& cmd)
         }
 
         // check if distance to the WP has changed and output new message if it has
-        float dist_to_wp = get_distance(current_loc, next_WP);
+        const float dist_to_wp = get_distance(current_loc, next_WP);
         if (!is_equal(distance_past_wp, dist_to_wp)) {
             distance_past_wp = dist_to_wp;
             gcs_send_text_fmt(MAV_SEVERITY_INFO, "Passed waypoint #%i. Distance %um",
@@ -356,7 +356,7 @@ bool Rover::verify_loiter_unlimited(const AP_Mission::Mission_Command& cmd)
 // verify_loiter_time - check if we have loitered long enough
 bool Rover::verify_loiter_time(const AP_Mission::Mission_Command& cmd)
 {
-    bool result = verify_nav_wp(cmd);
+    const bool result = verify_nav_wp(cmd);
     if (result) {
         gcs_send_text(MAV_SEVERITY_WARNING, "Finished active loiter\n");
         // if we have finished active loitering - turn it off
@@ -376,7 +376,7 @@ void Rover::nav_set_yaw_speed()
         return;
     }
 
-    int32_t steering = steerController.get_steering_out_angle_error(guided_yaw_speed.turn_angle);
+    const int32_t steering = steerController.get_steering_out_angle_error(guided_yaw_speed.turn_angle);
     SRV_Channels::set_output_scaled(SRV_Channel::k_steering, steering);
 
     // speed param in the message gives speed as a proportion of cruise speed.

APMrover2/control_modes.cpp

@@ -5,7 +5,7 @@ static const int16_t CH_7_PWM_TRIGGER = 1800;
 void Rover::read_control_switch()
 {
     static bool switch_debouncer;
-    uint8_t switchPosition = readSwitch();
+    const uint8_t switchPosition = readSwitch();
 
     // If switchPosition = 255 this indicates that the mode control channel input was out of range
     // If we get this value we do not want to change modes.
@@ -49,7 +49,7 @@ void Rover::read_control_switch()
 }
 
 uint8_t Rover::readSwitch(void) {
-    uint16_t pulsewidth = hal.rcin->read(g.mode_channel - 1);
+    const uint16_t pulsewidth = hal.rcin->read(g.mode_channel - 1);
     if (pulsewidth <= 900 || pulsewidth >= 2200) {
         return 255;  // This is an error condition
     }

APMrover2/failsafe.cpp

@@ -19,7 +19,7 @@ void Rover::failsafe_check()
     static uint16_t last_mainLoop_count;
     static uint32_t last_timestamp;
     static bool in_failsafe;
-    uint32_t tnow = AP_HAL::micros();
+    const uint32_t tnow = AP_HAL::micros();
 
     if (mainLoop_count != last_mainLoop_count) {
         // the main loop is running, all is OK

APMrover2/radio.cpp

@@ -78,7 +78,7 @@ void Rover::rudder_arm_disarm_check()
     if (!arming.is_armed()) {
         // when not armed, full right rudder starts arming counter
         if (channel_steer->get_control_in() > 4000) {
-            uint32_t now = millis();
+            const uint32_t now = millis();
 
             if (rudder_arm_timer == 0 ||
                 now - rudder_arm_timer < 3000) {
@@ -99,7 +99,7 @@ void Rover::rudder_arm_disarm_check()
         // This is disabled for skid steering otherwise when tring to turn a skid steering rover around
         // the rover would disarm
         if (channel_steer->get_control_in() < -4000) {
-            uint32_t now = millis();
+            const uint32_t now = millis();
 
             if (rudder_arm_timer == 0 ||
                 now - rudder_arm_timer < 3000) {
@@ -154,10 +154,10 @@ void Rover::read_radio()
           motor2 = throttle - 0.5*steering
         */          
 
-        float motor1 = channel_steer->norm_input();
+        const float motor1 = channel_steer->norm_input();
-        float motor2 = channel_throttle->norm_input();
+        const float motor2 = channel_throttle->norm_input();
-        float steering_scaled = motor1 - motor2;
+        const float steering_scaled = motor1 - motor2;
-        float throttle_scaled = 0.5f * (motor1 + motor2);
+        const float throttle_scaled = 0.5f * (motor1 + motor2);
 
         int16_t steer = channel_steer->get_radio_trim();
         int16_t thr   = channel_throttle->get_radio_trim();

APMrover2/system.cpp

@@ -513,7 +513,7 @@ void Rover::notify_mode(enum mode new_mode)
  */
 uint8_t Rover::check_digital_pin(uint8_t pin)
 {
-    int8_t dpin = hal.gpio->analogPinToDigitalPin(pin);
+    const int8_t dpin = hal.gpio->analogPinToDigitalPin(pin);
     if (dpin == -1) {
         return 0;
     }
@@ -534,7 +534,7 @@ bool Rover::should_log(uint32_t mask)
     if (!(mask & g.log_bitmask) || in_mavlink_delay) {
         return false;
     }
-    bool ret = hal.util->get_soft_armed() || DataFlash.log_while_disarmed();
+    const bool ret = hal.util->get_soft_armed() || DataFlash.log_while_disarmed();
     if (ret && !DataFlash.logging_started() && !in_log_download) {
         start_logging();
     }