misra 2.5 doesn't handle macro definitions with #ifdefines

[Dzid]

1.c:

#ifdef TEST1
    #define A 1
#else
    #define B 2
#endif

#ifdef TEST2
    #include "1.h"
#endif


int main(void){
    #ifdef USE_A
        return A;
    #else
        return B;
    #endif
}

// of all the examples only this one is not reported
#ifndef TEST3
    #define TEST3
#endif

1.h:

#define C 1

./cppcheck --enable=all --addon=misra 1.c -DTEST1

I get:

Checking 1.c ...
Checking 1.c: TEST1=1...
1.c:4:0: style: misra violation (use --rule-texts=<file> to get proper output) [misra-c2012-2.5]
    #define A 1
^
1.c:6:0: style: misra violation (use --rule-texts=<file> to get proper output) [misra-c2012-2.5]
    #define B 2
^
1.h:3:0: style: misra violation (use --rule-texts=<file> to get proper output) [misra-c2012-2.5]
    #define C 1
^
nofile:0:0: information: Active checkers: 295/1002 (use --checkers-report=<filename> to see details) [checkersReport]

I would expect none of them be a violation.

The only one that is not reported is the TEST3 which is a special case used for header guards discussed here .

[Daniel Marjamäki]

If this was your explicit real world code then I would argue that the code is not well written. Why have two separate macros TEST1 and USE_A that must always be set to the same value otherwise the compiler will fail.

[Dzid]

I am so sorry. I don't know why this forum doesn't auto-subscribe to threads.

It was some time and I am trying to find the real world code. But by simply looking at my examples without cross-checking with the real code I tend to agree with you.

Except for unused #define C 1 violation. If the header is not included, I don't think it should be even checked.

[Daniel Marjamäki]

Do you have some proof that these violations are technically false positives? According to misra. Do you see some related discussion in the misra forum for instance?

[Daniel Marjamäki]

For information PC-lint Plus also seem to write such warnings. You can open URL https://pclintplus.com/gmp/demo/ and try this code:

#define A 1  // <- PC-lint reports 2.5 here

int main(void){
    #ifdef USE_A
        return A;
    #endif
    return 0;
}