# git rev-parse -q --verify 7d42223a874f7426b58792166fce20f78581b5c4^{commit} 7d42223a874f7426b58792166fce20f78581b5c4 already have revision, skipping fetch # git checkout -q -f -B kisskb 7d42223a874f7426b58792166fce20f78581b5c4 # git clean -qxdf # < git log -1 # commit 7d42223a874f7426b58792166fce20f78581b5c4 # Author: Masahiro Yamada # Date: Wed Apr 8 03:43:36 2020 +0900 # # kbuild: support LLVM=1 to switch the default tools to Clang/LLVM # # As Documentation/kbuild/llvm.rst implies, building the kernel with a # full set of LLVM tools gets very verbose and unwieldy. # # Provide a single switch LLVM=1 to use Clang and LLVM tools instead # of GCC and Binutils. You can pass it from the command line or as an # environment variable. # # Please note LLVM=1 does not turn on the integrated assembler. You need # to pass LLVM_IA=1 to use it. When the upstream kernel is ready for the # integrated assembler, I think we can make it default. # # We discussed what we need, and we agreed to go with a simple boolean # flag that switches both target and host tools: # # https://lkml.org/lkml/2020/3/28/494 # https://lkml.org/lkml/2020/4/3/43 # # Some items discussed, but not adopted: # # - LLVM_DIR # # When multiple versions of LLVM are installed, I just thought supporting # LLVM_DIR=/path/to/my/llvm/bin/ might be useful. # # CC = $(LLVM_DIR)clang # LD = $(LLVM_DIR)ld.lld # ... # # However, we can handle this by modifying PATH. So, we decided to not do # this. # # - LLVM_SUFFIX # # Some distributions (e.g. Debian) package specific versions of LLVM with # naming conventions that use the version as a suffix. # # CC = clang$(LLVM_SUFFIX) # LD = ld.lld(LLVM_SUFFIX) # ... # # will allow a user to pass LLVM_SUFFIX=-11 to use clang-11 etc., # but the suffixed versions in /usr/bin/ are symlinks to binaries in # /usr/lib/llvm-#/bin/, so this can also be handled by PATH. # # Signed-off-by: Masahiro Yamada # Reviewed-by: Nathan Chancellor # Tested-by: Nathan Chancellor # build # Tested-by: Nick Desaulniers # Reviewed-by: Nick Desaulniers # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 7d42223a874f7426b58792166fce20f78581b5c4 # < make -s -j 10 ARCH=powerpc O=/kisskb/build/kbuild_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc64_defconfig # Added to kconfig CONFIG_SMP=n # < make -s -j 10 ARCH=powerpc O=/kisskb/build/kbuild_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- help # make -s -j 10 ARCH=powerpc O=/kisskb/build/kbuild_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- olddefconfig # make -s -j 10 ARCH=powerpc O=/kisskb/build/kbuild_ppc64_defconfig+UP_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:72:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:401:21: note: 'pdeo' was declared here /kisskb/src/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec': /kisskb/src/fs/ext4/extents.c:5009:23: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/trace/trace_events.c: In function 'event_create_dir': /kisskb/src/kernel/trace/trace_events.c:2040:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1741:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:247:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:227:19: note: 'i' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2598:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1859:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/core/devlink.c: In function 'devlink_fmsg_prepare_skb': /kisskb/src/net/core/devlink.c:4957:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/btrfs/backref.c: In function 'is_shared_data_backref': /kisskb/src/fs/btrfs/backref.c:394:9: warning: missing braces around initializer [-Wmissing-braces] /kisskb/src/fs/btrfs/backref.c:394:9: warning: (near initialization for 'target.rbnode') [-Wmissing-braces] /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2151:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/namei.c: In function 'handle_dots': /kisskb/src/fs/namei.c:1805:10: warning: 'inode' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/namei.c:1805:10: warning: 'seq' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1799:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1712:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/usb/core/devio.c: In function 'async_completed': /kisskb/src/drivers/usb/core/devio.c:625:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/bridge/br_netlink.c: In function 'br_process_vlan_info': /kisskb/src/net/bridge/br_netlink.c:571:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/io_uring.c: In function '__io_sqe_files_update': /kisskb/src/fs/io_uring.c:6617:13: warning: 'err' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/kbuild_ppc64_defconfig+UP_powerpc-gcc4.6 # Build took: 0:05:34.895892