# git gc
# git rev-parse -q --verify 5478b37e294b44d4836c96d132e5be51e251eb08^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/mirror/linux-kbuild.git for-next
# git rev-parse -q --verify 5478b37e294b44d4836c96d132e5be51e251eb08^{commit}
5478b37e294b44d4836c96d132e5be51e251eb08
# git checkout -q -f -B kisskb 5478b37e294b44d4836c96d132e5be51e251eb08
# git clean -qxdf
# < git log -1
# commit 5478b37e294b44d4836c96d132e5be51e251eb08
# Author: Masahiro Yamada <masahiroy@kernel.org>
# Date:   Fri Feb 12 01:11:54 2021 +0900
# 
#     gen_compile_commands: prune some directories
#     
#     If directories are passed to gen_compile_commands.py, os.walk() traverses
#     all the subdirectories to search for .cmd files, but we know some of them
#     are not worth traversing.
#     
#     Use the 'topdown' parameter of os.walk to prune them.
#     
#     Documentation about the 'topdown' option of os.walk:
#       When topdown is True, the caller can modify the dirnames list
#       in-place (perhaps using del or slice assignment), and walk() will
#       only recurse into the subdirectories whose names remain in dirnames;
#       this can be used to prune the search, impose a specific order of
#       visiting, or even to inform walk() about directories the caller
#       creates or renames before it resumes walk() again. Modifying
#       dirnames when topdown is False has no effect on the behavior of
#       the walk, because in bottom-up mode the directories in dirnames
#       are generated before dirpath itself is generated.
#     
#     This commit prunes four directories, .git, Documentation, include, and
#     tools.
#     
#     The first three do not contain any C files. My main motivation is the
#     last one, tools/ directory.
#     
#     Commit 6ca4c6d25949 ("gen_compile_commands: do not support .cmd files
#     under tools/ directory") stopped supporting the tools/ directory.
#     The current code no longer picks up .cmd files from the tools/
#     directory.
#     
#     If you run:
#     
#       ./scripts/clang-tools/gen_compile_commands.py --log_level=INFO
#     
#     then, you will see several "File ... not found" log messages.
#     
#     This is expected, and I do not want to support the tools/ directory.
#     However, without an explicit comment "do not support tools/", somebody
#     might try to get it back. Clarify this.
#     
#     Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
#     Acked-by: Nathan Chancellor <nathan@kernel.org>
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 5478b37e294b44d4836c96d132e5be51e251eb08
# < make -s -j 10 ARCH=arm64 O=/kisskb/build/kbuild_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  defconfig
# < make -s -j 10 ARCH=arm64 O=/kisskb/build/kbuild_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  help
# make -s -j 10 ARCH=arm64 O=/kisskb/build/kbuild_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  olddefconfig
# make -s -j 10 ARCH=arm64 O=/kisskb/build/kbuild_arm64-defconfig_arm64-gcc5.4 CROSS_COMPILE=/opt/cross/kisskb/br-aarch64-glibc-2016.08-613-ge98b4dd/bin/aarch64-linux-  
arch/arm64/Makefile:25: ld does not support --fix-cortex-a53-843419; kernel may be susceptible to erratum
arch/arm64/Makefile:33: LSE atomics not supported by binutils
Completed OK
# rm -rf /kisskb/build/kbuild_arm64-defconfig_arm64-gcc5.4
# Build took: 0:11:03.005990