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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu, 8 Feb 2018 09:45:09 -0800
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Subject: Re: [RFC PATCH 5/7] kconfig: invoke silentoldconfig when compiler is updated
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Nicolas Pitre <nicolas.pitre@linaro.org>,
        "Luis R . Rodriguez" <mcgrof@suse.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Ulf Magnusson <ulfalizer@gmail.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Martin Schwidefsky <schwidefsky@de.ibm.com>,
        Pavel Machek <pavel@ucw.cz>,
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On Thu, Feb 8, 2018 at 9:19 AM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> Should this be checked?
> Or, is it just "Don't do it" thing?

I think it's probably a "Don't do it".

In fact, maybe we should just make it very explicit that you need to
re-run "make *config" by hand if you have updated your compiler.

So instead of your "run silentoldconfig" if the compiler version has
changed, just literally error out and say "compiler has changed,
re-run configuration".

That way there are no subtle silent failures where you might end up -
by mistake - building just modules with a new compiler and different
options. Because people would be *aware* of the re-configuration.

Anyway, I suspect this is a tiny detail that we don't have to set in
stone right now. Maybe worry about it more when/if it actually becomes
something that people notice?

              Linus