kconfig: add merge_config.sh script

#!/bin/sh

#  merge_config.sh - Takes a list of config fragment values, and merges

#  them one by one. Provides warnings on overridden values, and specified

#  values that did not make it to the resulting .config file (due to missed

#  dependencies or config symbol removal).

#

#  Portions reused from kconf_check and generate_cfg:

#  http://git.yoctoproject.org/cgit/cgit.cgi/yocto-kernel-tools/tree/tools/kconf_check

#  http://git.yoctoproject.org/cgit/cgit.cgi/yocto-kernel-tools/tree/tools/generate_cfg

#

#  Copyright (c) 2009-2010 Wind River Systems, Inc.

#  Copyright 2011 Linaro

#

#  This program is free software; you can redistribute it and/or modify

#  it under the terms of the GNU General Public License version 2 as

#  published by the Free Software Foundation.

#

#  This program is distributed in the hope that it will be useful,

#  but WITHOUT ANY WARRANTY; without even the implied warranty of

#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

#  See the GNU General Public License for more details.

clean_up() {

       rm -f $TMP_FILE

       exit

}

trap clean_up SIGHUP SIGINT SIGTERM

usage() {

	echo "Usage: $0 [OPTIONS] [CONFIG [...]]"

	echo "  -h    display this help text"

	echo "  -m    only merge the fragments, do not execute the make command"

	echo "  -n    use allnoconfig instead of alldefconfig"

}

MAKE=true

ALLTARGET=alldefconfig

while true; do

	case $1 in

	"-n")

		ALLTARGET=allnoconfig

		shift

		continue

		;;

	"-m")

		MAKE=false

		shift

		continue

		;;

	"-h")

		usage

		exit

		;;

	*)

		break

		;;

	esac

done

MERGE_LIST=$*

SED_CONFIG_EXP="s/^\(# \)\{0,1\}\(CONFIG_[a-zA-Z0-9_]*\)[= ].*/\2/p"

TMP_FILE=$(mktemp ./.tmp.config.XXXXXXXXXX)

# Merge files, printing warnings on overrided values

for MERGE_FILE in $MERGE_LIST ; do

	echo "Merging $MERGE_FILE"

	CFG_LIST=$(sed -n "$SED_CONFIG_EXP" $MERGE_FILE)

	for CFG in $CFG_LIST ; do

		grep -q -w $CFG $TMP_FILE

		if [ $? -eq 0 ] ; then

			PREV_VAL=$(grep -w $CFG $TMP_FILE)

			NEW_VAL=$(grep -w $CFG $MERGE_FILE)

			if [ "x$PREV_VAL" != "x$NEW_VAL" ] ; then

			echo Value of $CFG is redefined by fragment $MERGE_FILE:

			echo Previous  value: $PREV_VAL

			echo New value:       $NEW_VAL

			echo

			fi

			sed -i "/$CFG[ =]/d" $TMP_FILE

		fi

	done

	cat $MERGE_FILE >> $TMP_FILE

done

if [ "$MAKE" = "false" ]; then

	cp $TMP_FILE .config

	echo "#"

	echo "# merged configuration written to .config (needs make)"

	echo "#"

	clean_up

	exit

fi

# Use the merged file as the starting point for:

# alldefconfig: Fills in any missing symbols with Kconfig default

# allnoconfig: Fills in any missing symbols with # CONFIG_* is not set

make KCONFIG_ALLCONFIG=$TMP_FILE $ALLTARGET

# Check all specified config values took (might have missed-dependency issues)

for CFG in $(sed -n "$SED_CONFIG_EXP" $TMP_FILE); do

	REQUESTED_VAL=$(sed -n "$SED_CONFIG_EXP" $TMP_FILE | grep -w -e "$CFG")

	ACTUAL_VAL=$(sed -n "$SED_CONFIG_EXP" .config | grep -w -e "$CFG")

	if [ "x$REQUESTED_VAL" != "x$ACTUAL_VAL" ] ; then

		echo "Value requested for $CFG not in final .config"

		echo "Requested value:  $REQUESTED_VAL"

		echo "Actual value:     $ACTUAL_VAL"

		echo ""

	fi

done

clean_up