# git rev-parse -q --verify 76426e238834f0927dee9925e8832179b8d56d6e^{commit}
76426e238834f0927dee9925e8832179b8d56d6e
already have revision, skipping fetch
# git checkout -q -f -B kisskb 76426e238834f0927dee9925e8832179b8d56d6e
# git clean -qxdf
# < git log -1
# commit 76426e238834f0927dee9925e8832179b8d56d6e
# Author: Masahiro Yamada <masahiroy@kernel.org>
# Date:   Wed Apr 8 00:53:52 2020 +0900
# 
#     kbuild: add dummy toolchains to enable all cc-option etc. in Kconfig
#     
#     Staring v4.18, Kconfig evaluates compiler capabilities, and hides CONFIG
#     options your compiler does not support. This works well if you configure
#     and build the kernel on the same host machine.
#     
#     It is inconvenient if you prepare the .config that is carried to a
#     different build environment (typically this happens when you package
#     the kernel for distros) because using a different compiler potentially
#     produces different CONFIG options than the real build environment.
#     So, you probably want to make as many options visible as possible.
#     In other words, you need to create a super-set of CONFIG options that
#     cover any build environment. If some of the CONFIG options turned out
#     to be unsupported on the build machine, they are automatically disabled
#     by the nature of Kconfig.
#     
#     However, it is not feasible to get a full-featured compiler for every
#     arch.
#     
#     This issue was discussed here:
#     
#       https://lkml.org/lkml/2019/12/9/620
#     
#     Other than distros, savedefconfig is also a problem. Some arch sub-systems
#     periodically resync defconfig files. If you use a less-capable compiler
#     for savedefconfig, options that do not meet 'depends on $(cc-option,...)'
#     will be forcibly disabled. So, 'make defconfig && make savedefconfig'
#     may silently change the behavior.
#     
#     This commit adds a set of dummy toolchains that pretend to support any
#     feature.
#     
#     Most of compiler features are tested by cc-option, which simply checks
#     the exit code of $(CC). The dummy tools are shell scripts that always
#     exit with 0. So, $(cc-option, ...) is evaluated as 'y'.
#     
#     There are more complicated checks such as:
#     
#       scripts/gcc-x86_{32,64}-has-stack-protector.sh
#       scripts/gcc-plugin.sh
#       scripts/tools-support-relr.sh
#     
#     scripts/dummy-tools/gcc passes all checks.
#     
#     From the top directory of the source tree, you can do:
#     
#        $ make CROSS_COMPILE=scripts/dummy-tools/ oldconfig
#     
#     Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
#     Reviewed-by: Philipp Rudo <prudo@linux.ibm.com>
#     Tested-by: Jeremy Cline <jcline@redhat.com>
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-gcc --version
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-ld --version
# < git log --format=%s --max-count=1 76426e238834f0927dee9925e8832179b8d56d6e
# < make -s -j 48 ARCH=sh O=/kisskb/build/kbuild_sh-defconfig_sh4-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-  defconfig
# < make -s -j 48 ARCH=sh O=/kisskb/build/kbuild_sh-defconfig_sh4-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-  help
# make -s -j 48 ARCH=sh O=/kisskb/build/kbuild_sh-defconfig_sh4-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-  olddefconfig
# make -s -j 48 ARCH=sh O=/kisskb/build/kbuild_sh-defconfig_sh4-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/sh4-linux/bin/sh4-linux-  
  Generating include/generated/machtypes.h
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
/kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S: Assembler messages:
/kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:385: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence
/kisskb/src/arch/sh/kernel/cpu/sh4/../sh3/../../entry-common.S:388: Warning: overflow in branch to syscall_exit_work; converted into longer instruction sequence
/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:471:21: note: 'pdeo' was declared here
/kisskb/src/mm/vmstat.c: In function 'sysctl_vm_numa_stat_handler':
/kisskb/src/mm/vmstat.c:90:5: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec':
/kisskb/src/fs/ext4/extents.c:4774:23: warning: 'ret' 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/kernel/trace/trace_events.c: In function 'event_create_dir':
/kisskb/src/kernel/trace/trace_events.c:2189:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/futex.c: In function 'do_futex':
/kisskb/src/kernel/futex.c:1676:3: warning: 'oldval' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/futex.c:1652:6: note: 'oldval' was declared here
/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/fs/ext4/readpage.c: In function 'ext4_mpage_readpages':
/kisskb/src/fs/ext4/readpage.c:416:1: warning: the frame size of 1180 bytes is larger than 1024 bytes [-Wframe-larger-than=]
/kisskb/src/fs/mpage.c: In function '__mpage_writepage':
/kisskb/src/fs/mpage.c:690:1: warning: the frame size of 1152 bytes is larger than 1024 bytes [-Wframe-larger-than=]
/kisskb/src/fs/mpage.c: In function 'do_mpage_readpage':
/kisskb/src/fs/mpage.c:338:1: warning: the frame size of 1108 bytes is larger than 1024 bytes [-Wframe-larger-than=]
/kisskb/src/drivers/sh/clk/cpg.c: In function 'r8':
/kisskb/src/drivers/sh/clk/cpg.c:41:2: warning: passing argument 1 of 'ioread8' discards 'const' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/iomap.h:29:21: note: expected 'void *' but argument is of type 'const void *'
/kisskb/src/drivers/sh/clk/cpg.c: In function 'r16':
/kisskb/src/drivers/sh/clk/cpg.c:46:2: warning: passing argument 1 of 'ioread16' discards 'const' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/iomap.h:30:21: note: expected 'void *' but argument is of type 'const void *'
/kisskb/src/drivers/sh/clk/cpg.c: In function 'r32':
/kisskb/src/drivers/sh/clk/cpg.c:51:2: warning: passing argument 1 of 'ioread32' discards 'const' qualifier from pointer target type [enabled by default]
/kisskb/src/include/asm-generic/iomap.h:32:21: note: expected 'void *' but argument is of type 'const void *'
/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/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]
  Kernel: arch/sh/boot/zImage is ready
Completed OK
# rm -rf /kisskb/build/kbuild_sh-defconfig_sh4-gcc4.6
# Build took: 0:00:48.616154