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From:   Linus Torvalds <torvalds@linuxfoundation.org>
Date:   Sat, 4 Sep 2021 10:22:25 -0700
Message-ID: <CAHk-=wi+XKYN+3u=_fm=ExqpEaHdER0XuKxVauHYVCPKpKR97Q@mail.gmail.com>
Subject: Re: [GIT PULL v2] Kbuild updates for v5.15-rc1
To:     Florian Weimer <fweimer@redhat.com>
Cc:     Segher Boessenkool <segher@kernel.crashing.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        llvm@lists.linux.dev, linux-toolchains@vger.kernel.org
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On Sat, Sep 4, 2021 at 8:19 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> In any case, it would be nice to know what the real motivation is.

I don't know about the original motivation, but the reason I like that
patch after-the-fact is that I've actually been in situations where I
test out self-built compilers without installing them.

Then it's convenient to have a completely standalone kernel tree.

Nobody cares about things like <stdatomic.h> They are completely
irrelevant for the kernel, exactly because we've always just done our
own, or used __builtin_xyz() for things.

<stdarg.h> is the only actual core header file that we have always
taken from the installed system headers - because historically it
really was required. Everything else we can just do ourselves.

                 Linus