Received-SPF: pass (google.com: domain of linux-kernel+bounces-30334-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
Precedence: bulk
MIME-Version: 1.0
References: <20230307102441.94417-1-conor.dooley@microchip.com>
 <20230608-dispatch-sneer-aa09bd7b2eb8@wendy> <CANiq72nnph7LS1fLRtHz8NJ91PWXPaUnm0EuoV3wrbvK398AnA@mail.gmail.com>
 <20230608-spiritism-gonad-5f5aff4c3a24@wendy> <20240117-swiftly-parasail-618d62972d6e@spud>
 <CANiq72mVKCOAuK4Qe+8AHmpkFwyJsVfx8AqB7ccGi3DYpSSWcw@mail.gmail.com> <20240118-implode-delirium-eefdd86e170e@spud>
In-Reply-To: <20240118-implode-delirium-eefdd86e170e@spud>
From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date: Thu, 18 Jan 2024 17:09:40 +0100
Message-ID: <CANiq72nx1s_nyvPW86jL7eiOxROr18LfOJqNtw8L42CP+gkhRg@mail.gmail.com>
Subject: Re: [PATCH v1 0/2] RISC-V: enable rust
To: Conor Dooley <conor@kernel.org>
Cc: Conor Dooley <conor.dooley@microchip.com>, linux-riscv@lists.infradead.org, 
	Miguel Ojeda <ojeda@kernel.org>, Alex Gaynor <alex.gaynor@gmail.com>, 
	Wedson Almeida Filho <wedsonaf@gmail.com>, Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>, 
	=?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>, 
	Jonathan Corbet <corbet@lwn.net>, Paul Walmsley <paul.walmsley@sifive.com>, 
	Palmer Dabbelt <palmer@dabbelt.com>, Nathan Chancellor <nathan@kernel.org>, 
	Nick Desaulniers <ndesaulniers@google.com>, Tom Rix <trix@redhat.com>, 
	rust-for-linux@vger.kernel.org, linux-doc@vger.kernel.org, 
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

On Thu, Jan 18, 2024 at 4:49=E2=80=AFPM Conor Dooley <conor@kernel.org> wro=
te:
>
> The bit that worries me most is bindgen, and in particular detecting the
> version of libclang used. I mentioned to Nathan or Nick about needing a
> buildtime test for the version of LIBCLANG being used.
> I'm less worried about this for LLVM=3D1 builds, since while I think it i=
s
> possible to provide a LIBCLANG path to the build system, I suspect that
> for LLVM=3D1 builds it's almost always going to match the LLVM toolchain
> in use.

`scripts/rust_is_available.sh` tests whether `libclang` is at least
the minimum LLVM supported version; and under `LLVM=3D1` builds, it also
tests whether the `bindgen` found one matches the C compiler. Do you
mean something like that?

For `bindgen` under GCC builds, we will eventually want a "proper" way
to use GCC instead (or possibly other approaches like querying the
information): https://github.com/rust-lang/rust-bindgen/issues/1949.
Recently, there has been a thread in our Zulip and a couple people are
experimenting: https://rust-for-linux.zulipchat.com/#narrow/stream/288089-G=
eneral/topic/Bindgen.20--.20GCC.20backend.20port

> I'll do another rebase and resend after the merge window closes I
> suppose :)

Thanks!

Cheers,
Miguel