# git gc
# git rev-parse -q --verify 0a6de78cff600cb991f2a1b7ed376935871796a0^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/mirror/linux-kbuild.git for-next
# git rev-parse -q --verify 0a6de78cff600cb991f2a1b7ed376935871796a0^{commit}
0a6de78cff600cb991f2a1b7ed376935871796a0
# git checkout -q -f -B kisskb 0a6de78cff600cb991f2a1b7ed376935871796a0
# git clean -qxdf
# < git log -1
# commit 0a6de78cff600cb991f2a1b7ed376935871796a0
# Author: Nathan Chancellor <nathan@kernel.org>
# Date:   Fri Oct 14 13:42:11 2022 -0700
# 
#     lib/Kconfig.debug: Add check for non-constant .{s,u}leb128 support to DWARF5
#     
#     When building with a RISC-V kernel with DWARF5 debug info using clang
#     and the GNU assembler, several instances of the following error appear:
#     
#       /tmp/vgettimeofday-48aa35.s:2963: Error: non-constant .uleb128 is not supported
#     
#     Dumping the .s file reveals these .uleb128 directives come from
#     .debug_loc and .debug_ranges:
#     
#       .Ldebug_loc0:
#               .byte   4                               # DW_LLE_offset_pair
#               .uleb128 .Lfunc_begin0-.Lfunc_begin0    #   starting offset
#               .uleb128 .Ltmp1-.Lfunc_begin0           #   ending offset
#               .byte   1                               # Loc expr size
#               .byte   90                              # DW_OP_reg10
#               .byte   0                               # DW_LLE_end_of_list
#     
#       .Ldebug_ranges0:
#               .byte   4                               # DW_RLE_offset_pair
#               .uleb128 .Ltmp6-.Lfunc_begin0           #   starting offset
#               .uleb128 .Ltmp27-.Lfunc_begin0          #   ending offset
#               .byte   4                               # DW_RLE_offset_pair
#               .uleb128 .Ltmp28-.Lfunc_begin0          #   starting offset
#               .uleb128 .Ltmp30-.Lfunc_begin0          #   ending offset
#               .byte   0                               # DW_RLE_end_of_list
#     
#     There is an outstanding binutils issue to support a non-constant operand
#     to .sleb128 and .uleb128 in GAS for RISC-V but there does not appear to
#     be any movement on it, due to concerns over how it would work with
#     linker relaxation.
#     
#     To avoid these build errors, prevent DWARF5 from being selected when
#     using clang and an assembler that does not have support for these symbol
#     deltas, which can be easily checked in Kconfig with as-instr plus the
#     small test program from the dwz test suite from the binutils issue.
#     
#     Link: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
#     Link: https://github.com/ClangBuiltLinux/linux/issues/1719
#     Signed-off-by: Nathan Chancellor <nathan@kernel.org>
#     Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
#     Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-ld --version
# < git log --format=%s --max-count=1 0a6de78cff600cb991f2a1b7ed376935871796a0
# < make -s -j 24 ARCH=m68k O=/kisskb/build/kbuild_m68k-defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-  defconfig
# < make -s -j 24 ARCH=m68k O=/kisskb/build/kbuild_m68k-defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-  help
# make -s -j 24 ARCH=m68k O=/kisskb/build/kbuild_m68k-defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-  olddefconfig
# make -s -j 24 ARCH=m68k O=/kisskb/build/kbuild_m68k-defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/m68k-linux/bin/m68k-linux-  
Completed OK
# rm -rf /kisskb/build/kbuild_m68k-defconfig_m68k-gcc11
# Build took: 0:08:49.214185