xref: /linux/scripts/mkcompile_h (revision b24413180f5600bcb3bb70fbed5cf186b60864bd)
1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3
4TARGET=$1
5ARCH=$2
6SMP=$3
7PREEMPT=$4
8CC=$5
9
10vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
11
12# If compile.h exists already and we don't own autoconf.h
13# (i.e. we're not the same user who did make *config), don't
14# modify compile.h
15# So "sudo make install" won't change the "compiled by <user>"
16# do "compiled by root"
17
18if [ -r $TARGET -a ! -O include/generated/autoconf.h ]; then
19  vecho "  SKIPPED $TARGET"
20  exit 0
21fi
22
23# Do not expand names
24set -f
25
26# Fix the language to get consistent output
27LC_ALL=C
28export LC_ALL
29
30if [ -z "$KBUILD_BUILD_VERSION" ]; then
31	if [ -r .version ]; then
32		VERSION=`cat .version`
33	else
34		VERSION=0
35		echo 0 > .version
36	fi
37else
38	VERSION=$KBUILD_BUILD_VERSION
39fi
40
41if [ -z "$KBUILD_BUILD_TIMESTAMP" ]; then
42	TIMESTAMP=`date`
43else
44	TIMESTAMP=$KBUILD_BUILD_TIMESTAMP
45fi
46if test -z "$KBUILD_BUILD_USER"; then
47	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
48else
49	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
50fi
51if test -z "$KBUILD_BUILD_HOST"; then
52	LINUX_COMPILE_HOST=`hostname`
53else
54	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
55fi
56
57UTS_VERSION="#$VERSION"
58CONFIG_FLAGS=""
59if [ -n "$SMP" ] ; then CONFIG_FLAGS="SMP"; fi
60if [ -n "$PREEMPT" ] ; then CONFIG_FLAGS="$CONFIG_FLAGS PREEMPT"; fi
61UTS_VERSION="$UTS_VERSION $CONFIG_FLAGS $TIMESTAMP"
62
63# Truncate to maximum length
64
65UTS_LEN=64
66UTS_TRUNCATE="cut -b -$UTS_LEN"
67
68# Generate a temporary compile.h
69
70( echo /\* This file is auto generated, version $VERSION \*/
71  if [ -n "$CONFIG_FLAGS" ] ; then echo "/* $CONFIG_FLAGS */"; fi
72
73  echo \#define UTS_MACHINE \"$ARCH\"
74
75  echo \#define UTS_VERSION \"`echo $UTS_VERSION | $UTS_TRUNCATE`\"
76
77  echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
78  echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"
79
80  echo \#define LINUX_COMPILER \"`$CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//'`\"
81) > .tmpcompile
82
83# Only replace the real compile.h if the new one is different,
84# in order to preserve the timestamp and avoid unnecessary
85# recompilations.
86# We don't consider the file changed if only the date/time changed.
87# A kernel config change will increase the generation number, thus
88# causing compile.h to be updated (including date/time) due to the
89# changed comment in the
90# first line.
91
92if [ -r $TARGET ] && \
93      grep -v 'UTS_VERSION' $TARGET > .tmpver.1 && \
94      grep -v 'UTS_VERSION' .tmpcompile > .tmpver.2 && \
95      cmp -s .tmpver.1 .tmpver.2; then
96   rm -f .tmpcompile
97else
98   vecho "  UPD     $TARGET"
99   mv -f .tmpcompile $TARGET
100fi
101rm -f .tmpver.1 .tmpver.2
102