Error codes are constants, not enum. That fixes another MISRA violation.

libuavcan/include/uavcan/error.hpp

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <uavcan/impl_constants.hpp>
+#include <uavcan/stdint.hpp>
 
 namespace uavcan
 {
@@ -13,20 +14,22 @@ namespace uavcan
  * Functions that return signed integers may also return inverted error codes,
  * i.e. returned value should be inverted back to get the actual error code.
  */
-enum
+namespace
 {
-    ErrOk,
-    ErrFailure,
-    ErrInvalidParam,
-    ErrMemory,
-    ErrDriver,
-    ErrUnknownDataType,
-    ErrInvalidMarshalData,
-    ErrInvalidTransferListener,
-    ErrNotInited,
-    ErrRecursiveCall,
-    ErrLogic
-};
+
+const int16_t ErrOk                      = 0;
+const int16_t ErrFailure                 = 1;
+const int16_t ErrInvalidParam            = 2;
+const int16_t ErrMemory                  = 3;
+const int16_t ErrDriver                  = 4;
+const int16_t ErrUnknownDataType         = 5;
+const int16_t ErrInvalidMarshalData      = 6;
+const int16_t ErrInvalidTransferListener = 7;
+const int16_t ErrNotInited               = 8;
+const int16_t ErrRecursiveCall           = 9;
+const int16_t ErrLogic                   = 10;
+
+}
 
 /**
  * Fatal error handler.

libuavcan_drivers/linux/include/uavcan_linux/socketcan.hpp

@@ -226,7 +226,7 @@ class SocketCanIface : public uavcan::ICanIface
         /*
          * Flags
          */
-        loopback = !!(msg.msg_flags & MSG_CONFIRM);
+        loopback = (msg.msg_flags & static_cast<int>(MSG_CONFIRM)) != 0;
         return 1;
     }