Switch case fall through

[aca_broj_1]

I'm trying to get cppcheck 1.68 to warn on case statements without a dedicated break or fall through comment.

When I add the --experimental argument I get: cppcheck: error: unrecognized command line option: "--experimental". Has it been deprecated? Is there a replacement?

Thanks,
Aleks

[Daniel Marjamäki]

ehm.. as far as I know we haven't had a "--experimental" flag. But maybe I'm wrong.

I don't want to have that warning in cppcheck. I guess we should remove it.

I really like to warn about unintentional missing breaks. But Cppcheck does it without looking at comments/annotations.

I don't know if it helps you.. but clang has this warning.

[aca_broj_1]

I could have sworn it was in an earlier version... maybe I confused it with something else.

I know the functionality is there, and it's even in the test cases, take a look at https://github.com/danmar/cppcheck/blob/master/test/testother.cpp and see switchFallThroughCase
I would love to have this in cppcheck, 95% of the bugs in my code seem to stem from missing breaks.

[Daniel Marjamäki]

I don't want to have any FP here in this general case:

switch (x) {
case 1:
   foo();
case 2:
   bar();
};

With the checker switchFallThroughCase a comment must be added to suppress the warning. I don't like that. I think it's a bad idea that comments or annotations must be used to silence all FP.

I would love to detect more unintentional switch case fallthrough. If you have some good ideas how we can do it feel free to write a suggestion.

As an inspiration, we warn if a fall through results in useless code. For example the assignment "y = 1;" is useless here:

switch (x) {
case 1:
    y = 1;
case 2:
    y = 7;
    break;
}

If you check that code you'll get this warning:

[a.c:6] -> [a.c:8]: (warning) Variable 'y' is reassigned a value before the old one has been used. 'break;' missing?