[PATCH] D71082: Allow system header to provide their own implementation of some builtin

[George Burgess IV via Phabricator via cfe-commits]

george.burgess.iv added a comment.

Until recently, both CrOS and Android disabled FORTIFY wholesale when any of asan/msan/tsan were active. Bionic recently got support for FORTIFY playing nicely with sanitizers, but that support boils down to "turn off all the FORTIFY runtime checks, but leave the ones that generate compiler diags on."

A quick fix here would likely be to disable this builtin interception functionality if a sanitizer that isn't ubsan/CFI is enabled. Since all of this code + the nop `__warn` builtin we added is specifically targeted at supporting glibc's FORTIFY patterns, I don't think adding a `!sanitizers` check would be too ugly on its own?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D71082/new/

https://reviews.llvm.org/D71082