False positive running MISRA C 2012 Rule 13.4

[kylejacksonb]

There is odd behaviour, in that if we comment the first definition the violation is no longer reported.

struct MYPORT
{
    char a;
} *PORT;

#define FetOff (PORT->a = 1)    // Comment this line and the next is not reported
#define FetOn (PORT->a = 1)     // MISRA12_13.4    - Result of an assignment operator was used

Attached is a more complete example of the original code.

example.txt

[kylejacksonb]

Thanks @jasonbquinn