[Lldb-commits] [clang] [compiler-rt] [libcxx] [lldb] [llvm] Rename Sanitizer Coverage => Coverage Sanitizer (PR #106505)

[Izzy Muerte via lldb-commits]

bruxisma wrote:

> I think it change the meaning completely. I read "Coverage Sanitizer" as a tool which finds bugs in Coverage. When "Sanitizer Coverage" as a coverage used by sanitizers.
> 
> This component is not sanitizer at all, and the current name is more appropriate.

The documentation for this component literally reads

> LLVM has a simple code coverage instrumentation built in (SanitizerCoverage). It inserts calls to user-defined functions on function-, basic-block-, and edge- levels. 

Neither definition you've given fits what this feature does! It calls user defined instrumentation functions, it doesn't find bugs in coverage and it doesn't provide coverage used by sanitizers!

This is just like how instrumentation based command line arguments start with `-fprofile-` even if they *can't be used for profiling*, and how tools like *control flow integrity* use `-fsanitize`. This entire thing is a mess, and it's made even worse with the addition of [SanitizerStats](https://clang.llvm.org/docs/SanitizerStats.html) which relies on CFI and doesn't collect sanitizer statistics, even though CFI is only a sanitizer because it uses `-fsanitize` as a flag!

https://github.com/llvm/llvm-project/pull/106505