AP_Arming: remove bogus ARMING_CHECK_NONE 'bitmask value'

This looks like a bitmask value, but if you treat it like one (and
people have in the past!) by using logical operations then you get the
incorrect result.

Places which were checking for equivalence to ARMING_CHECK_NONE now
simply check the bitmask to see if it is all-empty.

libraries/AP_Arming/AP_Arming.cpp

@@ -155,8 +155,7 @@ bool AP_Arming::check_enabled(const enum AP_Arming::ArmingChecks check) const
 
 MAV_SEVERITY AP_Arming::check_severity(const enum AP_Arming::ArmingChecks check) const
 {
-    // A check value of ARMING_CHECK_NONE means that the check is always run
-    if (check_enabled(check) || check == ARMING_CHECK_NONE) {
+    if (check_enabled(check)) {
         return MAV_SEVERITY_CRITICAL;
     }
     return MAV_SEVERITY_DEBUG; // technically should be NOTICE, but will annoy users at that level
@@ -176,6 +175,19 @@ void AP_Arming::check_failed(const enum AP_Arming::ArmingChecks check, bool repo
     va_end(arg_list);
 }
 
+void AP_Arming::check_failed(bool report, const char *fmt, ...) const
+{
+    if (!report) {
+        return;
+    }
+    char taggedfmt[MAVLINK_MSG_STATUSTEXT_FIELD_TEXT_LEN+1];
+    hal.util->snprintf(taggedfmt, sizeof(taggedfmt), "PreArm: %s", fmt);
+    va_list arg_list;
+    va_start(arg_list, fmt);
+    gcs().send_textv(MAV_SEVERITY_CRITICAL, taggedfmt, arg_list);
+    va_end(arg_list);
+}
+
 bool AP_Arming::barometer_checks(bool report)
 {
     if ((checks_to_perform & ARMING_CHECK_ALL) ||
@@ -356,13 +368,13 @@ bool AP_Arming::compass_checks(bool report)
 
     // check if compass is calibrating
     if (_compass.is_calibrating()) {
-        check_failed(ARMING_CHECK_NONE, report, "Compass calibration running");
+        check_failed(report, "Compass calibration running");
         return false;
     }
 
     // check if compass has calibrated and requires reboot
     if (_compass.compass_cal_requires_reboot()) {
-        check_failed(ARMING_CHECK_NONE, report, "Compass calibrated requires reboot");
+        check_failed(report, "Compass calibrated requires reboot");
         return false;
     }
 
@@ -628,18 +640,18 @@ bool AP_Arming::servo_checks(bool report) const
 
         const uint16_t trim = c->get_trim();
         if (c->get_output_min() > trim) {
-            check_failed(ARMING_CHECK_NONE, report, "SERVO%d minimum is greater than trim", i + 1);
+            check_failed(report, "SERVO%d minimum is greater than trim", i + 1);
             check_passed = false;
         }
         if (c->get_output_max() < trim) {
-            check_failed(ARMING_CHECK_NONE, report, "SERVO%d maximum is less than trim", i + 1);
+            check_failed(report, "SERVO%d maximum is less than trim", i + 1);
             check_passed = false;
         }
     }
 
 #if HAL_WITH_IO_MCU
     if (!iomcu.healthy()) {
-        check_failed(ARMING_CHECK_NONE, report, "IOMCU is unhealthy");
+        check_failed(report, "IOMCU is unhealthy");
         check_passed = false;
     }
 #endif
@@ -687,7 +699,7 @@ bool AP_Arming::system_checks(bool report)
         }
     }
     if (AP::internalerror().errors() != 0) {
-        check_failed(ARMING_CHECK_NONE, report, "Internal errors (0x%x)", (unsigned int)AP::internalerror().errors());
+        check_failed(report, "Internal errors (0x%x)", (unsigned int)AP::internalerror().errors());
         return false;
     }
 
@@ -709,7 +721,7 @@ bool AP_Arming::proximity_checks(bool report) const
 
     // return false if proximity sensor unhealthy
     if (proximity->get_status() < AP_Proximity::Proximity_Good) {
-        check_failed(ARMING_CHECK_NONE, report, "check proximity sensor");
+        check_failed(report, "check proximity sensor");
         return false;
     }
 
@@ -769,9 +781,9 @@ bool AP_Arming::fence_checks(bool display_failure)
     }
 
     if (fail_msg == nullptr) {
-        check_failed(ARMING_CHECK_NONE, display_failure, "Check fence");
+        check_failed(display_failure, "Check fence");
     } else {
-        check_failed(ARMING_CHECK_NONE, display_failure, "%s", fail_msg);
+        check_failed(display_failure, "%s", fail_msg);
     }
 
     return false;

libraries/AP_Arming/AP_Arming.h

@@ -17,7 +17,6 @@ public:
     static AP_Arming *get_singleton();
 
     enum ArmingChecks {
-        ARMING_CHECK_NONE        = 0x0000,
         ARMING_CHECK_ALL         = (1U << 0),
         ARMING_CHECK_BARO        = (1U << 1),
         ARMING_CHECK_COMPASS     = (1U << 2),
@@ -140,6 +139,7 @@ protected:
     MAV_SEVERITY check_severity(const enum AP_Arming::ArmingChecks check) const;
     // handle the case where a check fails
     void check_failed(const enum AP_Arming::ArmingChecks check, bool report, const char *fmt, ...) const FMT_PRINTF(4, 5);
+    void check_failed(bool report, const char *fmt, ...) const FMT_PRINTF(3, 4);
 
     void Log_Write_Arm_Disarm();