[PATCH] D52386: [Lexer] Add udefined_behavior_sanitizer feature

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

I'm not at all convinced that this is a good thing. There isn't such a thing as "undefined behavior sanitizer". Rather, there are a whole bunch of different checks that fall under the same umbrella. This test seems on the surface to be about as meaningless as `__has_feature(warnings)` would be: it's useless to ask the question without knowing *which* warnings you're talking about. But perhaps there's some use case I've overlooked (and your description of the patch doesn't mention why you want this). What is the use case you're trying to address with this change?

If we want to change this, you'll also need to update `getPPTransparentSanitizers` to exclude all the UBSan checks, because it's no longer the case that those sanitizers only affect code generation.


Repository:
  rL LLVM

https://reviews.llvm.org/D52386