[Buildroot] [Patch v6 0/7] Add support for the Rust programming language

[Eric Le Bihan]

Hi!

On 17-06-28 12:20:35, Adrian Perez de Castro wrote:
> Hello Eric (and everybody else :D),
>
> I think it's great that there is work being done to bring Rust support to
> Buildroot, because the languge has been gaining a lot of traction, and people
> are now writing very interesting programs in it (I am a fan of RipGrep myself!
> If you don't know it, take a look at: https://github.com/BurntSushi/ripgrep)
>
> Recently I submitted v2 of a patch to add a LLVM package, and it would be
> interesting to coordinate to make your Rust patchset use it, instead of the
> Rust packaging providing its own copy of LLVM. You can see the patch in
> Patchwork:
>
>   https://patchwork.ozlabs.org/patch/777949/
>
> I am addin some comments inline below, please keep reading...
>
> On Sun, 25 Jun 2017 22:56:07 +0200, Eric Le Bihan <eric.le.bihan.dev at free.fr> wrote:
> > This series adds support for the Rust programming language by adding the
> > following packages:
> >
> >  - rustc: a virtual package for the Rust compiler.
> >  - rust-bin: provides a pre-built version of rustc.
> >  - rust: builds rustc from source.
> >
> > Both providers are able to cross-compile code for ARM, MIPS, PowerPC and
> > x86_64 architectures. Only the host variants are provided.
>
> This means that the “llvm” package should also provide a host variant of the
> package. I did a quick try adding “$(eval $(host-cmake-package))” plus a few
> minor changs locally and LLVM built just fine.

Yes. To build host-rust, the libraries from host-llvm would be required.
If you could provide a patch adding host-llvm, I'll happily test it.

> Regarding the architecture backends to enable, I imagine we would want host
> variant to have enabled *both* the host-native backend, and the target
> backend. Example: When building for ARM in x86_64, we would enable the “ARM”
> and “X86” LLVM backends for “host-llvm”, and only “ARM” for “llvm” (the target
> package). Would this be correct? Do you foresee any situation in which other
> backends should be enabled for either the host or target variants? Should we
> allow selecting from menuconfig which backends are compiled for the target
> “llvm” package?

IMHO, it is best to keep it simple with only the host and the target archs.

> Last but not least: Right now my patch for adding LLVM only builds the main
> libraries and binaries. Is this enough for Rust?

Yes.

BR,

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ELB