[libc] re-enable warnings for tests

[nickdesaulniers]

Link: #81917
Link: #119054

d0c2c0a split the compiler flags between the tests and object files. #119054 fixes warnings that crept in because these warnings we not re-enabled (d0c2c0a makes it sounds like they were never enabled?) Either way, we should work towards getting these turned back on, such that downstream users with such testing aren't finding such bugs downstream; instead we are upstream.

Specifically, there are many commented out warning diagnostic flags in libc/cmake/modules/LLVMLibCCompileOptionRules.cmake. We should comment those back in, and fix the existing issues.

[llvmbot]

@llvm/issue-subscribers-libc

Author: Nick Desaulniers (nickdesaulniers)

Link: #81917 Link: #119054

d0c2c0a split the compiler flags between the tests and object files. #119054 fixes warnings that crept in because these warnings we not re-enabled (d0c2c0a makes it sounds like they were never enabled?) Either way, we should work towards getting these turned back on, such that downstream users with such testing aren't finding such bugs downstream; instead we are upstream.

Specifically, there are many commented out warning diagnostic flags in libc/cmake/modules/LLVMLibCCompileOptionRules.cmake. We should comment those back in, and fix the existing issues.

[vinay-deshmukh]

Hi,
I've started work on this issue.

(Currently blocked due to : #113790 AND #120736)

For the latter, a PR is out, should get merged soon enough if there are additional approvals on it.

For the previous issue, I do have the code building locally on my m1, but as this relies on merging #120736 , I'll raise a PR for fixing builds on mac m1 once the previous PR goes in.

And finally after all this, the PR to close the current issue can go in.

[nickdesaulniers]

You should still be able to build/run without setting -DLLVM_LIBC_FULL_BUILD=ON. We don't currently support fullbuild on macos (and should update our documentation to reflect that).

[vinay-deshmukh]

You should still be able to build/run without setting -DLLVM_LIBC_FULL_BUILD=ON. We don't currently support fullbuild on macos (and should update our documentation to reflect that).

TIL, I was able to trigger the warnings on an overlay build as well,

Raised https://github.com/llvm/llvm-project/pull/122835/files