Re: [PATCH] kbuild: rust: add `CONFIG_RUSTC_LLVM_VERSION`

Masahiro Yamada
2024-10-14T16:27:53Z

On Fri, Oct 11, 2024 at 9:06 PM Gary Guo <gary@garyguo.net> wrote:
>
> On Fri, 11 Oct 2024 13:53:47 +0200
> Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote:
>
> > On Fri, Oct 11, 2024 at 1:41 PM Gary Guo <gary@garyguo.net> wrote:
> > >
> > > The invocation of rustc-version is being moved from init/Kconfig to
> > > scripts/Kconfig.include for consistency with cc-version.
> >
> > Yeah, I am ambivalent. Dropping them would minimize changes and avoid
> > introducing something only used once, which would be nice too. Happy
> > either way.
>
> Another motivation is that in my helper inline series, I need to do
> arithmetic on LLVM version (divide it by 10000 to get major verison),
> which isn't possible for config options, but will work for variables
> defiend in Kconfig.include.
>
> I didn't mention it in the commit message for this patch because this
> is not my patch series :)

I tend to agree with Muguel.
The motivation of having cc-version in scripts/Kconfig.include
is to check the presence of the supported C compiler, as C compiler
is mandatory (in contrast, Rust compiler is optional).

If you have a reason to have it in scripts/Kconfig.include
for your future works, it is OK with me, but I cannot judge it.

>
> Best,
> Gary
>
> > > +if output=$("$@" --version --verbose 2>/dev/null | grep LLVM); then
> >
> > Similarly, I wonder if we should use '^LLVM version: ' here or similar
> > to minimize the chances the "LLVM" string appears elsewhere in the
> > future (perhaps in a custom string a vendor adds, though I would
> > expect them to add it lowercase). We are relying on having a $3 when
> > splitting anyway.
> >
> > Depending on what Masahiro prefers, I will take this one or the
> > one-invocation-only one.
> >
> > Thanks Gary!
> >
> > Cheers,
> > Miguel
>
>

--
Best Regards
Masahiro Yamada