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References: <20210414184604.23473-1-ojeda@kernel.org> <20210414184604.23473-6-ojeda@kernel.org>
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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 14 Apr 2021 12:19:21 -0700
Message-ID: <CAHk-=wgJvJJtd2mpYpx5+zn_hPrSOqGqi-Pxb7e+h+anhsLnQg@mail.gmail.com>
Subject: Re: [PATCH 05/13] Rust: Compiler builtins crate
To:     ojeda@kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        rust-for-linux@vger.kernel.org,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Geoffrey Thomas <geofft@ldpreload.com>,
        Finn Behrens <me@kloenk.de>,
        Adam Bratschi-Kaye <ark.email@gmail.com>,
        Wedson Almeida Filho <wedsonaf@google.com>
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On Wed, Apr 14, 2021 at 11:46 AM <ojeda@kernel.org> wrote:
>
> We also need a helpers C source file to contain some forwarders
> to C macros and inlined functions. For the moment, we only need it
> to call the `BUG()` macro, but we will be adding more later.

Not being a Rust person, I can only guess based on random pattern
matching, but this _looks_ like these "panicking intrinsics" panic at
run-time (by calling BUG()).

Is there some way these things could cause built-time link errors
instead, so that if somebody uses 128-bit shifts, or floating point
ops in the rust code, they show up as build failures, not as run-time
ones?

Hmm?

          Linus