[aengelke]

It's probably worth noting that TySan currently only catches aliasing violations that LLVM would be able to exploit. For some types, e.g. unions, Clang doesn't emit accurate type-based aliasing information and therefore TySan won't catch these.

[flohofwoe]

Which is fine I think, considering that union type punning is legal in C (and even in C++ where union type punning is UB I have never seen it break - theoretically it might of course).