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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
...
97 lines
2.5 KiB
Bash
Executable File
97 lines
2.5 KiB
Bash
Executable File
#!/bin/sh
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# SPDX-License-Identifier: GPL-2.0
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TARGET=$1
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ARCH=$2
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SMP=$3
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PREEMPT=$4
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CC=$5
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vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
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# If compile.h exists already and we don't own autoconf.h
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# (i.e. we're not the same user who did make *config), don't
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# modify compile.h
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# So "sudo make install" won't change the "compiled by <user>"
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# do "compiled by root"
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if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then
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vecho " SKIPPED $TARGET"
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exit 0
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fi
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# Do not expand names
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set -f
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# Fix the language to get consistent output
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LC_ALL=C
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export LC_ALL
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if [ -z "$KBUILD_BUILD_VERSION" ]; then
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VERSION=$(cat .version 2>/dev/null || echo 1)
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else
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VERSION=$KBUILD_BUILD_VERSION
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fi
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if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
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TIMESTAMP=`date`
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else
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TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
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fi
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if test -z "$KBUILD_BUILD_USER"; then
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LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
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else
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LINUX_COMPILE_BY=$KBUILD_BUILD_USER
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fi
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if test -z "$KBUILD_BUILD_HOST"; then
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LINUX_COMPILE_HOST=`hostname`
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else
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LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
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fi
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UTS_VERSION="#$VERSION"
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CONFIG_FLAGS=""
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if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
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if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
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UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
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# Truncate to maximum length
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UTS_LEN=64
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UTS_TRUNCATE="cut -b -$UTS_LEN"
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# Generate a temporary compile.h
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( echo /\* This file is auto generated, version $VERSION \*/
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if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
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echo \#define UTS_MACHINE \"$ARCH\"
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echo \#define UTS_VERSION \"`echo $UTS_VERSION | $UTS_TRUNCATE`\"
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echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
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echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"
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echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//'`\"
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) > .tmpcompile
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# Only replace the real compile.h if the new one is different,
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# in order to preserve the timestamp and avoid unnecessary
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# recompilations.
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# We don't consider the file changed if only the date/time changed.
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# A kernel config change will increase the generation number, thus
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# causing compile.h to be updated (including date/time) due to the
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# changed comment in the
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# first line.
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if [ -r $TARGET ] && \
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grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
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grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
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cmp -s .tmpver.1 .tmpver.2; then
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rm -f .tmpcompile
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else
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vecho " UPD $TARGET"
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mv -f .tmpcompile $TARGET
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fi
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rm -f .tmpver.1 .tmpver.2
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