[libcxx-commits] [libcxx] [libcxx] Recognize __UEFI__ predefine (PR #139327)

[Louis Dionne via libcxx-commits]

https://github.com/ldionne requested changes to this pull request.

There is no such thing as using libc++ "header only". Even using basic functionality like `std::sort` requires `libc++.so` or `libc++.a` to be available, because we externally instantiate some specializations of `std::sort` into the built library. Failing to have a built library available will yield to linker errors when you do perfectly normal things like calling `std::sort(int*, int*)`.

>From your comment, this target is still experimental. I would rather add support in libc++ once you have a good understanding of the changes required to libc++ to support the target, and it looks like this might be a bit early for that. Otherwise, as far as the project is concerned, this patch is introducing dead code and our policy is to reject such patches.

https://github.com/llvm/llvm-project/pull/139327