Yep, the copy-libcxx-headers-into-build-tree logic is so that they end
up somewhere where a just built clang will find them relative to itself
(it looks for something like ../include/c++/v1). It's purely a
convenience so you don't need to call `ninja install` to use a clang
that refers to headers t
(+Bogner, I think he originally added this)
My understanding is that we only did this copy step if you are building with a
clang that isn't installed so that the non-installed clang could find these
headers.
I'm pretty sure compiler-rt finds libcxx via the sources, not the build
directory.
I'
> Eric, this part of this change seems wrong to me. It causes the headers to
> be installed into the libcxx build directory instead of the LLVM one. If
> you build using the LLVM runtimes directory this puts the headers in the
> wrong place for clang to find them.
>
> Is there a reason you're copyi
