Post Syndicated from original https://lwn.net/Articles/911914/

Among the many quirks that make the C language so charming is the set of
behaviors that
it does not define; these include whether a char variable is a
signed quantity or not. The distinction often does not make a difference,
but there are exceptions. Kernel code, which runs on many different
architectures, is where exceptions can certainly be found. A recent
attempt to eliminate the uncertain signedness of char variables
did not get far — at least not in the direction it originally attempted to
go.