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Date:   Tue, 9 Mar 2021 13:15:27 -0800
From:   Fangrui Song <maskray@google.com>
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        clang-built-linux@googlegroups.com,
        Sedat Dilek <sedat.dilek@gmail.com>
Subject: Re: [PATCH v2 1/2] Makefile: Remove '--gcc-toolchain' flag
Message-ID: <20210309211527.us52fgxdzpf25xzw@google.com>
References: <20210302210646.3044738-1-nathan@kernel.org>
 <20210309205915.2340265-1-nathan@kernel.org>
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On 2021-03-09, Nathan Chancellor wrote:
>This flag was originally added to allow clang to find the GNU cross
>tools in commit 785f11aa595b ("kbuild: Add better clang cross build
>support"). This flag was not enough to find the tools at times so
>'--prefix' was added to the list in commit ef8c4ed9db80 ("kbuild: allow
>to use GCC toolchain not in Clang search path") and improved upon in
>commit ca9b31f6bb9c ("Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang
>cross compilation"). Now that '--prefix' specifies a full path and
>prefix, '--gcc-toolchain' serves no purpose because the kernel builds
>with '-nostdinc' and '-nostdlib'.
>
>This has been verified with self compiled LLVM 10.0.1 and LLVM 13.0.0 as
>well as a distribution version of LLVM 11.1.0 without binutils in the
>LLVM toolchain locations.
>
>Link: https://reviews.llvm.org/D97902
>Signed-off-by: Nathan Chancellor <nathan@kernel.org>

The wording looks good.

Reviewed-by: Fangrui Song <maskray@google.com>