[libc-commits] [libc] [libc] Add LIBC_NAMESPACE_HIDDEN_DECL macro (PR #97109)

[Joseph Huber via libc-commits]

jhuber6 wrote:

> > So, the patch where I prefer `-fvisibility=hidden` is at #97123. I believe this is much easier to manage than updating every single namespace declaration, specifically because all the normal entrypoints are actually inside of a namespace.
> 
> #97123 only addresses the issue for the CMake build though and we have other users that build LLVM libc with their own build system and want to make that they always get the right behavior. I don't think it's either or, we really want both of these changes since they're addressing different use cases.

Yeah, I think the solution is to take #97123 and then modify the `LIBC_NAMESPACE` macro to include the visibility in a follow-up.

https://github.com/llvm/llvm-project/pull/97109