[libcxx-commits] [PATCH] D148753: [libcxx] convert symbol checker from CMake target to lit test

[Louis Dionne via Phabricator via libcxx-commits]

ldionne added a comment.

In D148753#4332277 <https://reviews.llvm.org/D148753#4332277>, @daltenty wrote:

> Not to sure about the history of this filtering business either. Wouldn't removing one of these filtered symbols still constitute an ABI break, so you'd want to know about it regardless?

I mean, technically if we start depending on a symbol that we didn't depend on before, we could impact our ability to back-deploy to previous targets. However, I don't think that's really the intent of theses tests. What we're really trying to test is what the library is exporting.

And yeah, I don't think we should filter out any of the symbols we export, since they are all part of our ABI.

Stepping back, I think adding ABI testing to libc++abi and libunwind should hence not reuse the logic for libc++. I think we should do it "the right way" using llvm-ifs or similar, and then we can actually refactor the libc++ tests to use the same mechanism instead of the other way around. That's just a suggestion on how to proceed, however it doesn't seem logical to me to do work towards sharing the libc++ test mechanism with libc++abi when we know the libc++ mechanism is wrong.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D148753/new/

https://reviews.llvm.org/D148753