false positive in cppcheck 2.5: pointerOutOfBounds

[Jo]

Not sure if this has been reported by before, but there's another false positive in cppcheck 2.5 when run with --enable=portability. The test case is:

#include <stdio.h>  
int main(int argc, const char* argv[]) {
    argv++;
    if (argc>0) printf("%s\n", (argv-1)[0]);
    return 0;
}

Code compiles fine and is perfectly valid C:

# gcc foo3.c -o foo3 && ./foo3 
./foo3

...but cppcheck complains:

# cppcheck --enable=portability foo3.c 
Checking foo3.c ...
foo3.c:4:37: portability: Undefined behaviour, pointer arithmetic 'argv-1' is out of bounds. [pointerOutOfBounds]
    if (argc>0) printf("%s\n", (argv-1)[0]);
                                    ^

[Daniel Marjamäki]

Thanks! I have created https://trac.cppcheck.net/ticket/10367