Hi Julien,

Julien Lepiller <julien@lepiller.eu> writes:

> Hi Guix!
>
> This small patch series adds cross-clang, a cross-compiler version of
> clang. Clang doesn't really make a distinction between a native and a
> cross-build, it is already a cross-compiler, but this ensures that:
>
> 1. it actually works
> 2. it targets (%current-target-architecture) by default
>
> The rest of the series ensures that libcxx and libcxxabi can be
> cross-compiled with it.

That's really cool! Out of curiosity, what target are you interested in
that clang supports and GCC doesn't?  For instance I'm interested in
WebAssembly, and I've actually been contemplating how we could improve
support for cross-compilers based on Clang in Guix, to be able to
provide a working WebAssembly toolchain.

For context, such a toolchain will be needed to enable potential use of
WebAssembly in IceCat, for security purposes, see
https://hacks.mozilla.org/2021/12/webassembly-and-back-again-fine-grained-sandboxing-in-firefox-95/

I actually have a toolchain that works already, which targets the
wasm32-wasi-unknown triplet, but I wasn't convinced the way I did it was
the right way to go long term, so it needs more work.  I'm attaching the
patch in case there's anything useful to you in there already!

The approach I took was to create wrappers around clang/clang++ in order
to set the correct include paths, and then provide an isolated sysroot
for wasm32-wasi using union-build. This will work for IceCat, where
their should be a flag to pass a sysroot path, but we should be able to
do better in Guix.

I though I'd share in case that's helpful! I'll take a look at your
patches to see if I can build on top of them for a future WebAssembly
toolchain in Guix.

Thanks,
Pierre