[PATCH] D32842: Specify which sanitizers are covered by a sanitizer blacklist

[Vedant Kumar via Phabricator via cfe-commits]

vsk added a comment.

In https://reviews.llvm.org/D32842#768038, @eugenis wrote:

> This change scares me a bit, to be honest. Is this really that big of a problem? Blacklists are not supposed to be big, maybe we can tolerate a few false negatives?


I'd like to make it possible to deploy a larger default blacklist for one sanitizer without inhibiting the other sanitizers. This would be useful if we find a bug in a runtime check: we could temporarily work around the issue by deploying a new blacklist, instead of changing the compiler or build system. It won't be possible to do this if blacklist updates can introduce false negatives.

Also, as a separate point, I think a design which permits false negatives is worrisome in and of itself, and is worth fixing.

> Consider extending the blacklist syntax instead, the same way Valgrind does.

I like this idea. However, I think that it would require most of the changes in this patch, with some additional work to change SpecialCaseList.

> Blacklist entries could be annotated with a list of sanitizers they apply to, like
> 
> asan,ubsan : src: file.cc:line
> 
> or an even less verbose way using sections
> 
> [asan]
> src:
> src:
>  [msan]
> src:
> 
> As an extra benefit, all default blacklists can be merged into one.

It would be nice to combine the default blacklists into one file with separate sections for each sanitizer. I'll look into this (hopefully next week).


https://reviews.llvm.org/D32842