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Masahiro Yamada c8f3dea90e mkcompile_h: use printf for LINUX_COMPILE_BY

Commit 858805b336 ("kbuild: add $(BASH) to run scripts with
bash-extension") shed light on portability issues. Here is another one.

Since commit f07726048d ("Fix handling of backlash character in
LINUX_COMPILE_BY name"), we must escape a backslash contained in
LINUX_COMPILE_BY. This is not working on such distros as Ubuntu.

As the POSIX spec [1] says, if any of the operands contain a backslash
( '\' ) character, the results are implementation-defined.

The actual shell of /bin/sh could be bash, dash, etc. depending on
distros, and the behavior of builtin echo command is different among
them.

The bash builtin echo, unless -e is given, copies the arguments to
stdout without expanding escape sequences (BSD-like behavior).

The dash builtin echo, in contrast, adopts System V behavior, which
does expand escape sequences without any option given.

Even non-builtin /bin/echo behaves differently depending on the system.
Due to these variations, echo is considered as a non-portable command.
Using printf is the common solution to avoid the portability issue.

[1] https://pubs.opengroup.org/onlinepubs/009695399/utilities/echo.html

Fixes: 858805b336 ("kbuild: add $(BASH) to run scripts with bash-extension")
Reported-by: XXing Wei <xxing.wei@unisoc.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

2019-12-14 15:53:04 +09:00

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#!/bin/sh

SPDX-License-Identifier: GPL-2.0

TARGET=$1 ARCH=$2 SMP=$3 PREEMPT=$4 PREEMPT_RT=$5 CC=$6

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 if [ -n "$PREEMPT_RT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT_RT"; fi

Truncate to maximum length

UTS_LEN=64 UTS_VERSION="$(echo $UTS_VERSION $CONFIG_FLAGS $TIMESTAMP | cut -b -$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 "$UTS_VERSION"

printf '#define LINUX_COMPILE_BY "%s"\n' "$LINUX_COMPILE_BY" echo #define LINUX_COMPILE_HOST "$LINUX_COMPILE_HOST"

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

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