[PATCH] D23638: [compiler-rt] Don't build ubsan cxxabi sources when unused

[Francis Ricci via llvm-commits]

fjricci added a comment.

@beanz We could certainly do that, but the scope of that patch would be pretty significant - many of the sanitizers rely directly on these targets (which is why `RTUbsan_cxx` has to be created as a dummy target, instead of just not being created at all). It's probably the right move long term, but I think it's outside the scope of fixing the bug here.

The reason why this patch is necessary is that static linking of a sanitizer which includes `RTUbsan_cxx` will fail if libc++abi is unavailable, even though this code is never used or called when `SANITIZER_CAN_USE_CXXABI` is false.


https://reviews.llvm.org/D23638