09bd7c75e5
One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and
their results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation
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Merge tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
"One of the most remarkable improvements in this cycle is, Kbuild is
now able to cache the result of shell commands. Some variables are
expensive to compute, for example, $(call cc-option,...) invokes the
compiler. It is not efficient to redo this computation every time,
even when we are not actually building anything. Kbuild creates a
hidden file ".cache.mk" that contains invoked shell commands and their
results. The speed-up should be noticeable.
Summary:
- Fix arch build issues (hexagon, sh)
- Clean up various Makefiles and scripts
- Fix wrong usage of {CFLAGS,LDFLAGS}_MODULE in arch Makefiles
- Cache variables that are expensive to compute
- Improve cc-ldopton and ld-option for Clang
- Optimize output directory creation"
* tag 'kbuild-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (30 commits)
kbuild: move coccicheck help from scripts/Makefile.help to top Makefile
sh: decompressor: add shipped files to .gitignore
frv: .gitignore: ignore vmlinux.lds
selinux: remove unnecessary assignment to subdir-
kbuild: specify FORCE in Makefile.headersinst as .PHONY target
kbuild: remove redundant mkdir from ./Kbuild
kbuild: optimize object directory creation for incremental build
kbuild: create object directories simpler and faster
kbuild: filter-out PHONY targets from "targets"
kbuild: remove redundant $(wildcard ...) for cmd_files calculation
kbuild: create directory for make cache only when necessary
sh: select KBUILD_DEFCONFIG depending on ARCH
kbuild: fix linker feature test macros when cross compiling with Clang
kbuild: shrink .cache.mk when it exceeds 1000 lines
kbuild: do not call cc-option before KBUILD_CFLAGS initialization
kbuild: Cache a few more calls to the compiler
kbuild: Add a cache for generated variables
kbuild: add forward declaration of default target to Makefile.asm-generic
kbuild: remove KBUILD_SUBDIR_ASFLAGS and KBUILD_SUBDIR_CCFLAGS
hexagon/kbuild: replace CFLAGS_MODULE with KBUILD_CFLAGS_MODULE
...
2.5 KiB
Executable File
#!/bin/sh
SPDX-License-Identifier: GPL-2.0
TARGET=$1 ARCH=$2 SMP=$3 PREEMPT=$4 CC=$5
vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
If compile.h exists already and we don't own autoconf.h
(i.e. we're not the same user who did make *config), don't
modify compile.h
So "sudo make install" won't change the "compiled by "
do "compiled by root"
if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then vecho " SKIPPED $TARGET" exit 0 fi
Do not expand names
set -f
Fix the language to get consistent output
LC_ALL=C export LC_ALL
if [ -z "$KBUILD_BUILD_VERSION" ]; then VERSION=$(cat .version 2>/dev/null || echo 1) else VERSION=$KBUILD_BUILD_VERSION fi
if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
TIMESTAMP=date
else
TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
fi
if test -z "$KBUILD_BUILD_USER"; then
LINUX_COMPILE_BY=$(whoami | sed 's/\/\\/')
else
LINUX_COMPILE_BY=$KBUILD_BUILD_USER
fi
if test -z "$KBUILD_BUILD_HOST"; then
LINUX_COMPILE_HOST=hostname
else
LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
fi
UTS_VERSION="#$VERSION" CONFIG_FLAGS="" if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
Truncate to maximum length
UTS_LEN=64 UTS_TRUNCATE="cut -b -$UTS_LEN"
Generate a temporary compile.h
( echo /* This file is auto generated, version $VERSION */ if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
echo #define UTS_MACHINE "$ARCH"
echo #define UTS_VERSION "echo $UTS_VERSION | $UTS_TRUNCATE"
echo #define LINUX_COMPILE_BY "echo $LINUX_COMPILE_BY | $UTS_TRUNCATE"
echo #define LINUX_COMPILE_HOST "echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE"
echo #define LINUX_COMPILER "$CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//'"
) > .tmpcompile
Only replace the real compile.h if the new one is different,
in order to preserve the timestamp and avoid unnecessary
recompilations.
We don't consider the file changed if only the date/time changed.
A kernel config change will increase the generation number, thus
causing compile.h to be updated (including date/time) due to the
changed comment in the
first line.
if [ -r $TARGET ] &&
grep -v 'UTS_VERSION' $TARGET > .tmpver.1 &&
grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 &&
cmp -s .tmpver.1 .tmpver.2; then
rm -f .tmpcompile
else
vecho " UPD $TARGET"
mv -f .tmpcompile $TARGET
fi
rm -f .tmpver.1 .tmpver.2