#!/bin/sh

if [ $# -eq 1 ]  ; then
	OUTPUT=$1
fi

GVF=${OUTPUT}PERF-VERSION-FILE

LF='
'

# First check if there is a .git to get the version from git describe
# otherwise try to get the version from the kernel makefile
if test -d ../../.git -o -f ../../.git &&
	VN=$(git describe --abbrev=4 HEAD 2>/dev/null) &&
	case "$VN" in
	*$LF*) (exit 1) ;;
	v[0-9]*)
		git update-index -q --refresh
		test -z "$(git diff-index --name-only HEAD --)" ||
		VN="$VN-dirty" ;;
	esac
then
	VN=$(echo "$VN" | sed -e 's/-/./g');
else
	VN=$(make -sC ../.. kernelversion)
fi

VN=$(expr "$VN" : v*'\(.*\)')

if test -r $GVF
then
	VC=$(sed -e 's/^PERF_VERSION = //' <$GVF)
else
	VC=unset
fi
test "$VN" = "$VC" || {
	echo >&2 "PERF_VERSION = $VN"
	echo "PERF_VERSION = $VN" >$GVF
}