[clang] [WIP][DO NOT MERGE][Clang][Driver] Emit warning when -fsanitize-trap=<...> is passed without associated -fsanitize=<...> (PR #147997)

[Dan Liew via cfe-commits]

delcypher wrote:

@MaskRay 
> The current -fsanitize-trap behavior is intentional. See
https://discourse.llvm.org/t/clang-gsoc-2025-usability-improvements-for-trapping-undefined-behavior-sanitizer/84568/11

Yes we aware the current behavior is intentional. That however doesn't mean it's the right behavior. Our intention is to post a corresponding RFC but as part of the RFC we also wanted a sketch patch of what we are proposing so we can be concrete about our proposed alternative. We (myself & @Michael137) are working with a @anthonyhatran a Google Summer of Code mentee to get the sketch patch in good shape and then we will work on an RFC and then post it.

Although I understand you have good intentions behind proactively closing the PR please do not close our mentee's PR again. If it's ultimately rejected, we'll do it.

https://github.com/llvm/llvm-project/pull/147997