[libcxx-commits] [libcxx] [libc++][test][shared] Add @CMAKE_DL_LIBS@ when needed (PR #222797)

[Amilendra Kodithuwakku via libcxx-commits]

amilendra wrote:

@ldionne 
Thanks for your reply.

> Also, you seem to be using Glibc 2.17, which is outside of libc++'s support policy. 

We maintain the [Arm Toolchain for Linux toolchain ](https://support.arm.com/tools-and-software/arm-toolchain-for-linux#Supported-Devices) that has RHEL-8 support, which is where we are facing this issue.
Defining our own .cfg.in file was also [considered](https://github.com/arm/arm-toolchain/pull/1048/changes/35985d5a20457fb1e13226aff03ef5e7bbbb3f6e), but that would add the complexity of having to keep track if upstream libc++ requires making changes to it. If the build or tests break it would be easy to identify when changes are needed, but if things silently pass we will not be aware that our downstream .cfg.in file needs maintenance. 

Having downstream config files almost identical to the upstream variants with just one line difference seemed a bit redundant, and because we could reproduce this on upstream libc++ as well, we felt there could be a issue in upstream libc++ that would be worth getting fixed.

However, if the libc++ maintainters do not see an issue in the behavior pointed out, and if Glibc 2.17 is out of upstream libc++ support, I suppose we have no option other than to go an alternative route.

Thanks again

CC: @pawosm-arm 



https://github.com/llvm/llvm-project/pull/222797