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Date:   Sat, 11 Jul 2020 14:03:17 -0700
From:   Josh Triplett <josh@joshtriplett.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Christian Brauner <christian.brauner@ubuntu.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        alex.gaynor@gmail.com, Greg KH <gregkh@linuxfoundation.org>,
        geofft@ldpreload.com, jbaublitz@redhat.com,
        Masahiro Yamada <masahiroy@kernel.org>,
        Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        LKML <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        Kees Cook <keescook@chromium.org>
Subject: Re: Linux kernel in-tree Rust support
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On Fri, Jul 10, 2020 at 04:54:11PM -0700, Linus Torvalds wrote:
> On Fri, Jul 10, 2020 at 3:59 PM Josh Triplett <josh@joshtriplett.org> wrote:
> > As I recall, Greg's biggest condition for initial introduction of this
> > was to do the same kind of "turn this Kconfig option on and turn an
> > option under it off" trick that LTO uses, so that neither "make
> > allnoconfig" nor "make allyesconfig" would require Rust until we've had
> > plenty of time to experiment with it.
> 
> No, please make it a "is rust available" automatic config option. The
> exact same way we already do the compiler versions and check for
> various availability of compiler flags at config time.

That sounds even better, and will definitely allow for more testing.

We just need to make sure that any kernel CI infrastructure tests that
right away, then, so that failures don't get introduced by a patch from
someone without a Rust toolchain and not noticed until someone with a
Rust toolchain tests it.

- Josh