AP_InternalError: change panic to return error code as string in SITL

libraries/AP_InternalError/AP_InternalError.cpp

@@ -17,7 +17,9 @@ void AP_InternalError::error(const AP_InternalError::error_t e, uint16_t line) {
         // don't panic on these to facilitate watchdog testing
         break;
     default:
-        AP_HAL::panic("internal error %u", unsigned(e));
+        char buffer[50];
+        AP::internalerror().error_to_string(buffer, ARRAY_SIZE(buffer), e);
+        AP_HAL::panic("AP_InternalError::error_t::%s", buffer);
     }
 #endif
     internal_errors |= uint32_t(e);
@@ -29,9 +31,7 @@ void AP_InternalError::error(const AP_InternalError::error_t e, uint16_t line) {
     hal.util->persistent_data.internal_error_last_line = line;
 }
 
-void AP_InternalError::errors_as_string(uint8_t *buffer, const uint16_t len) const
-{
-    static const char * const error_bit_descriptions[] {
+static const char * const error_bit_descriptions[] {
     "mapfailure",  // logger_mapfailure
     "miss_struct",  // logger_missing_logstructure
     "write_mssfmt",  // logger_logwrite_missingfmt
@@ -62,10 +62,18 @@ void AP_InternalError::errors_as_string(uint8_t *buffer, const uint16_t len) con
     "dma_fail",
     "params_restored",
     "invalid arguments",
-    };
+};
+
+static_assert((1U<<(ARRAY_SIZE(error_bit_descriptions))) == uint32_t(AP_InternalError::error_t::__LAST__), "too few descriptions for bits");
 
-    static_assert((1U<<(ARRAY_SIZE(error_bit_descriptions))) == uint32_t(AP_InternalError::error_t::__LAST__), "too few descriptions for bits");
+void AP_InternalError::error_to_string(char *buffer, const uint16_t len, error_t error_code) const
+{
+    uint32_t temp = log2f(int(error_code));
+    strncpy(buffer, error_bit_descriptions[temp], len - 1);
+}
 
+void AP_InternalError::errors_as_string(uint8_t *buffer, const uint16_t len) const
+{
     buffer[0] = 0;
     uint32_t buffer_used = 0;
     for (uint8_t i=0; i<ARRAY_SIZE(error_bit_descriptions); i++) {

libraries/AP_InternalError/AP_InternalError.h

@@ -83,6 +83,9 @@ public:
     // internal errors.  buffer will always be null-terminated.
     void errors_as_string(uint8_t *buffer, uint16_t len) const;
 
+    // convert an error code to a string
+    void error_to_string(char *buffer, uint16_t len, error_t error_code) const;
+
     uint32_t count() const { return total_error_count; }
 
     // internal_errors - return mask of internal errors seen