[c4mpute]

> all you have to do to avoid UB on signed integer overflow is check for overflow before doing the operation

All you have to do is add a check for overflow _that the compiler will not throw away because "UB won't happen"_. The very thing you want to avoid makes avoiding it very hard, and lots of bugs have resulted from compilers "optimizing" away such overflow checks.

[chongli]

This is covered in the article and numerous replies in this thread. Use <stdckdint.h>.

[c4mpute]

stdckdint.h is only available in C23. The problem has existed before that and lead to tons of exploits and bugs.