[clang] [Clang] Overflow Pattern Exclusions (PR #100272)

[Kees Cook via cfe-commits]

kees wrote:

> Can we split `-fsanitize=unsigned-integer-overflow` into `-fsanitize=unsigned-integer-overflow-patternA,unsigned-integer-overflow-patternB,unsigned-integer-overflow-patternC...` ?
> 
> Then it's quite intuitive to disable them with `no-sanitize`.

Yikes, no way. The pattern exclusions apply to all of the overflow-related sanitizers. Each is a small behavioral difference; they're not separate sanitizers nor do they apply to only one sanitizer.

If `-fsanitize-pattern-exclusion` isn't wanted, perhaps `-fsanitize-overflow=pattern-exclude-{none,all,add-overflow-test,post-decr-while,negated-unsigned-const}`? But I still prefer it as-as.

https://github.com/llvm/llvm-project/pull/100272