#!/bin/sh

KERNELDIR=/lib/modules/$(uname -r)/build
KERNFIRST=false
PREPARSER="./preparser"
DODIFF=dodiff
UNIQUE=false

dodiff() {
  if $KERNFIRST ; then
    diff -u $EXTRAOPT $2 $1
  else
    diff -u $EXTRAOPT $1 $2
  fi
}

dodiffuni() {
    echo -n "Processing $1 ... "
    TMPNAME=/tmp/`basename $1`.$$ 
    $PREPARSER -c $CTRLNAME $1 $TMPNAME
    RES=$?
    if [ "$RES" -eq "0" ] ; then 
	echo diff original
	dodiff $1 $2
	rm $TMPNAME
	return 0
    fi
    if [ "$RES" -eq "2" ] ; then
	echo diff modified
	dodiff $TMPNAME $2
	rm $TMPNAME
	return 0
    fi
    echo "problem with $PREPARSER retcode $RES"
    exit 1
}


#
# Print usage and exit
#
usage() {
	cat<<EOM

	stddiff is used for generating diffs of the cvs-tree
		versus the kernel-tree.

	stddiff [-r] [-h] [-k DIR] [-u] [-c FILE] [-w] [files ...]

	Options:

	-h      This Text.
	-r      Reverse direction (kernel versus cvs).
	-k DIR  Kerneltree is in DIR instead of /usr/src/linux
	-u      Make a diff for a unique kernel-tree 
                (preprocessing with $PREPARSER)
	-c FILE	Use FILE as control file for $PREPARSER (only with -u)
	-w      Ignore white space when comparing lines 

	Without any files given, within the whole tree, the "right"
	files are diffed. When any files are given in the commandline,
	only those are diffed.

EOM
	exit
}

#
# Check, if argument is a linux kernel dir
#
checkkernel() {
	if [ -f $1/Makefile ] ; then
#		if [ "`grep ^vmlinux: $1/Makefile | grep vmlinux`" != "" ] ; then
			return 0
#		fi
	fi
	echo "The given argument does not look like a kernel dir"
	exit 1
}

#
# Determine a control file name
#
calc_ctrl_file() {
	eval `sed -n 's/^\([A-Z]*\) = \([0-9]*\)$/\1=\2/p' $KERNELDIR/Makefile`
	echo "Current kernel version is $VERSION.$PATCHLEVEL.$SUBLEVEL"
	if [ -z "$CTRLNAME" ] ; then
		CTRLNAME=v$VERSION.$PATCHLEVEL.$SUBLEVEL.ctrl
		if [ -f $CTRLNAME ] ; then
			return 0
		fi
		CTRLNAME=v$VERSION.$PATCHLEVEL.ctrl
		if [ -f $CTRLNAME ] ; then
			return 0
		fi
		CTRLNAME=default.ctrl
	fi
	if [ -f $CTRLNAME ] ; then
		return 0
	fi
	echo "No control file found"
	exit 1
}

#
# Determine a version depend file name
#
calc_version_file() {
	VERSION_NAME=$1.v$VERSION.$PATCHLEVEL.$SUBLEVEL
	if [ -f $VERSION_NAME ] ; then
		return 0
	fi
	VERSION_NAME=$1.v$VERSION.$PATCHLEVEL
	if [ -f $VERSION_NAME ] ; then
		return 0
	fi
	VERSION_NAME=""
	return 1
}

while getopts :rhk:uc:w a ; do
	case $a in
		\?) case $OPTARG in
			k)  echo "-k requires Kernel directory parameter"
					;;
			*)  echo "Unknown option: -$OPTARG"
				echo "Try stddiff -h"
				;;
			esac
			exit 1
			;;
		k)  checkkernel $OPTARG
			KERNELDIR=$OPTARG
			;;
		c)  CTRLNAME=$OPTARG
			;;
		u)  UNIQUE=true
			;;
		r)  KERNFIRST=true
			;;
		w)  EXTRAOPT=-w
			;;
		h)  usage
			;;
	esac
done
shift `expr $OPTIND - 1`

if [ -z "$VERSION" -o -z "$PATCHLEVEL" ] ; then
    if ! [ -f $KERNELDIR/Makefile ] ; then
	echo "VERSION/PATCHLEVEL not set and no Makefile to read from"
	exit 1
    fi
    eval `sed -n 's/^\([A-Z]*\) = \([0-9]*\)$/\1=\2/p' $KERNELDIR/Makefile`
fi
echo "Current kernel version is $VERSION.$PATCHLEVEL.$SUBLEVEL"

if $UNIQUE ; then
	DODIFF=dodiffuni
	calc_ctrl_file
fi

echo -n "Using $DODIFF $EXTRAOPT"

if $UNIQUE ; then
	echo " with controlfile $CTRLNAME"
else
	echo
fi

if [ $# != 0 ]; then
	for i in $* ; do
		$DODIFF $i $KERNELDIR/$i
	done
else
	for i in drivers/isdn/hardware/mISDN/*.[ch] ; do
		$DODIFF $i $KERNELDIR/$i
	done
	for i in include/linux/*.h ; do
		if [ "$i" = "include/linux/isdn_compat.h" -a \
		     "$UNIQUE" = "true" ] ; then
			echo "$i skipped"
		else
			$DODIFF $i $KERNELDIR/$i
		fi
	done
	
	for i in drivers/isdn/hardware/Makefile \
		drivers/isdn/hardware/Kconfig \
		drivers/isdn/hardware/mISDN/Makefile \
		drivers/isdn/hardware/mISDN/Rules.make \
		drivers/isdn/hardware/mISDN/Kconfig ; do
		calc_version_file $i 
		if [ -n "$VERSION_NAME" ] ; then
	    		dodiff $VERSION_NAME $KERNELDIR/$i
		else
			if [ -f $i ] ; then
				echo "use version independ $i for version v$VERSION.$PATCHLEVEL.$SUBLEVEL"
				$DODIFF $i $KERNELDIR/$i
			else
				echo "no $i for version v$VERSION.$PATCHLEVEL.$SUBLEVEL found -- skipped"
			fi
		fi
	done
fi