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Date:   Fri, 3 Jan 2020 15:19:19 +0100
From:   "Jason A. Donenfeld" <Jason@zx2c4.com>
To:     linux-kernel@vger.kernel.org, llvmlinux@lists.linuxfoundation.org,
        clang-built-linux@googlegroups.com
Subject: instructions: using clang's static analyzer on arbitrary kernel
 modules
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Hi,

I figure I should document this somewhere. Here's what I've been using
to run both clang's scan-build and sparse at the same time on the
wireguard kernel module:

rm -rf /tmp/check-wireguard-linux
make CC=clang O=/tmp/check-wireguard-linux defconfig -j$(nproc)
printf 'CONFIG_WIREGUARD=m\nCONFIG_WIREGUARD_DEBUG=y\n' >> /tmp/check-wireguard-linux/.config
make CC=clang O=/tmp/check-wireguard-linux prepare -j$(nproc)
scan-build --use-cc=clang -maxloop 100 --view --keep-going make CC=clang O=/tmp/check-wireguard-linux drivers/net/wireguard/wireguard.ko -j$(nproc) C=2 CF="-D__CHECK_ENDIAN__"

It seems to generally work well at catching super stupid mistakes.

Regards,
Jason