Tuomas Ahola <taahol@xxxxxx> writes: > In file bulk-checkin.c, three warnings are emitted by > "-Wsign-compare", two of which are caused by trivial loop iterator > type mismatches. The third one is also an uncomplicated case for > which a simple cast is a safe and sufficient action as the variable in > question only holds positive values (from sizeof() expression). The point of the sign-compare is that a positive value that is assigned to a signed variable may wrap around to become negative, causing a comparison with an unsigned type with the same size to fail. So "only holds positive" is not a good enough explanation for the reason why this workaround for the "-Wsign-compare" false-positive [*] does not make things too bad. The key thing is that the value assigned to this "ssize_t rsize" variable is a small non-negative value that can fit both size_t and ssize_t. [Footnote] * If we take -Wsign-compare too literally, it is warning every time a signed quantity and an unsigned quantity is being compared, so we could argue that there is no false-positive. But that is an obviously pretty useless warning, when we can trivially tell that the value in a signed variable cannot have wrapped around.
