[libcxx-dev] [RFC] A vision for building the runtimes

[Martin Storsjö via libcxx-dev]

On Thu, 22 Oct 2020, Louis Dionne via libcxx-dev wrote:

> - Monorepo
>    This is the "easy" and most common way to build the runtimes. It 
> builds the runtimes as subprojects of LLVM (with LLVM_ENABLE_PROJECTS), 
> with the same compiler that's used to build LLVM.

Btw, unrelated to the topic at hand, but related to monorepo builds in 
general, as I've brought up some time before - it'd be great for various 
reasons to be able to do such a build (building the tools, not the 
runtimes) by pointing cmake directly at the llvm-project root instead of 
at the llvm subdir.

Last time this was brought up, Chris [1] mentioned that it'd be doable, 
but would require a bit of work to make the produced files 
(<builddir>/bin/clang etc) end up in the root of the build dir, instead of 
in a subdir, like <builddir>/llvm/bin/clang. My cmake-fu is a bit too weak 
to easily pinpoint what needs to be fixed to proceed with this though...

[1] http://lists.llvm.org/pipermail/llvm-dev/2019-November/136466.html

// Martin