#!/bin/bash

#

# This script merges together the hierarchy of CONFIG_* files under generic

# and debug to form the necessary $PACKAGE_NAME<version>-<arch>-<variant>.config

# files for building RHEL kernels, based on the contents of a control file

PACKAGE_NAME="${1:-kernel}" # defines the package name used

KVERREL="${2:-}"

SUBARCH="${3:-}" # defines a specific arch

SCRIPT="$(readlink -f $0)"

OUTPUT_DIR="$PWD"

SCRIPT_DIR="$(dirname $SCRIPT)"

LANG=en_US.UTF-8

# to handle this script being a symlink

cd $SCRIPT_DIR

set errexit

set nounset

control_file="config_generation"

cleanup()

{

	rm -f config-*

}

die()

{

	echo "$1"

	cleanup

	exit 1

}

function combine_config_layer()

{

	dir=$1

	file="config-$(echo $dir | sed -e 's|/|-|g')"

	if [ $(ls $dir/ | grep -c "^CONFIG_") -eq 0 ]; then

		touch $file

		return

	fi

	cat $dir/CONFIG_* > $file

}

function merge_configs()

{

	archvar=$1

	arch=$(echo "$archvar" | cut -f1 -d"-")

	configs=$2

	order=$3

	name=$OUTPUT_DIR/$PACKAGE_NAME-$archvar.config

	echo -n "Building $name ... "

	touch config-merging config-merged

	# apply based on order

	skip_if_missing=""

	for o in $order

	do

		for config in $(echo $configs | sed -e 's/:/ /g')

		do

			cfile="config-$o-$config"

			test -n "$skip_if_missing" && test ! -e $cfile && continue

			perl merge.pl $cfile config-merging > config-merged

			if [ ! $? -eq 0 ]; then

				die "Failed to merge $cfile"

			fi

			mv config-merged config-merging

		done

		# first configs in $order is baseline, all files should be

		# there.  second pass is overrides and can be missing.

		skip_if_missing="1"

	done

	if [ "x$arch" == "xaarch64" ]; then

		echo "# arm64" > $name

	elif [ "x$arch" == "xppc64le" ]; then

		echo "# powerpc" > $name

	elif [ "x$arch" == "xs390x" ]; then

		echo "# s390" > $name

	elif [ "x$arch" == "xarmv7hl" ]; then

		echo "# arm" > $name

	elif [ "x$arch" == "xi686" ]; then

		echo "# i386" > $name

	else

		echo "# $arch" > $name

	fi

	sort config-merging >> $name

	rm -f config-merged config-merging

	echo "done"

}

while read line

do

	if [ $(echo "$line" | grep -c "^#") -ne 0 ]; then

		continue

	elif [ $(echo "$line" | grep -c "^$") -ne 0 ]; then

		continue

	elif [ $(echo "$line" | grep -c "^ORDER") -ne 0 ]; then

		order=$(echo "$line" | cut -f2 -d"=")

		for o in $order

		do

			glist=$(find $o -type d)

			for d in $glist

			do

				combine_config_layer $d

			done

		done

	else

		arch=$(echo "$line" | cut -f1 -d"=")

		configs=$(echo "$line" | cut -f2 -d"=")

		if [ -n "$SUBARCH" -a "$SUBARCH" != "$arch" ]; then

			continue

		fi

		merge_configs $arch $configs "$order"

	fi

done < $control_file

# A passed in kernel version implies copy to final location

# otherwise defer to another script

if test -n "$KVERREL"

then

	for i in kernel-*.config

	do

		NEW="$(echo $i | sed "s/$PACKAGE_NAME-$SUBARCH/$PACKAGE_NAME-$KVERREL-$SUBARCH/")"

		mv $i $NEW

	done

fi

cleanup