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From:   Kees Cook <keescook@chromium.org>
Date:   Wed, 28 Mar 2018 04:29:26 -0700
Message-ID: <CAGXu5j+mJeG+POhgPkoanX8SVnY0LvTDoBUsyTNGpKh0KYiHMQ@mail.gmail.com>
Subject: Re: [PATCH v2 17/21] gcc-plugins: always build plugins with C++
To:     Masahiro Yamada <yamada.masahiro@socionext.com>
Cc:     linux-kbuild <linux-kbuild@vger.kernel.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Ulf Magnusson <ulfalizer@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        "Luis R . Rodriguez" <mcgrof@kernel.org>,
        Nicolas Pitre <nico@linaro.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Kernel Hardening <kernel-hardening@lists.openwall.com>,
        Emese Revfy <re.emese@gmail.com>
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On Mon, Mar 26, 2018 at 10:29 PM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> If the target compiler is GCC 4.8 or newer, plugins are compiled with
> HOSTCXX.  Otherwise, gcc-plugin.sh will select HOSTCC or HOSTCXX.
>
> To simplify things, drop the HOSTCC support for plugins.  If you use
> GCC plugins, the requirement for the target compiler is GCC 4.8 (or
> older compiler with necessary features backported).  This is a feature
> for advanced users, so this requirement would not be a big deal.
> Currently, building plugins requires GCC 4.5, so this is not a big jump.

Emese already NAKed this, and I'd agree. 4.5 to 4.8 is quite a jump
(see all the threads on minimum gcc versions). Until we're at 4.8 as a
minimum, let's leave this as-is. "To simply things" doesn't seem like
a good enough reason to me.

-Kees

-- 
Kees Cook
Pixel Security