#! /bin/sh
#
# Prex configuration script
#

quit()
{
    cat >&2 <<ERRORMSG

ERROR: $@
ERRORMSG
	exit 1
}

usage()
{
	if [ -n "$*" ]; then
		echo "configure: $*"
	fi
	cat <<USAGE

Usage: configure [options]

 General options:
    --target=TARGET         target system
    --cross-compile=PREFIX  prefix for cros-compile tools
    --no-debug              disable all debug code

 Supported targets:
    i386-pc i386-nommu arm-gba avr32-ngw100
USAGE
	exit 1
}

setdefaults()
{
	[ -d conf ] ||
		quit "configure must be run from the top source level"

	target=""
	cross=""
	srcdir=`pwd`
}

checkpath()
{
	CONFIG_IN=$srcdir/conf/$arch/config.$arch-$platform
	CMDBOX_IN=$srcdir/conf/etc/cmdbox.conf
	CONFIG_MK=$srcdir/conf/config.mk
	CONFIG_H=$srcdir/conf/config.h

	[ -f $CONFIG_IN ] ||
		quit "can not find $CONFIG_IN"
}

getoptions()
{
	while [ $# != 0 ]; do
		case $1 in
		--*=*)
			option=`expr "x$1" : 'x\([^=]*\)='`
			optarg=`expr "x$1" : 'x[^=]*=\(.*\)'`
			;;
		--*)
			option=$1
			;;
		*)
			usage "unrecognized option $1"
			;;
		esac

		case $option in
		--help)
			usage
			;;
		--target)
			target=$optarg
			;;
		--cross-compile)
			cross=$optarg
			;;
		--no-debug)
			nodebug=1
			;;
		*)
			usage "unrecognized option $1"
			;;
		esac
		shift
	done
}

gettarget()
{
	if [ "x$target" = x ] ; then
		echo "Warning: '--target' option was not specified"
		echo "The target system was set to 'i386-pc'"	
		target="i386-pc"
	fi

	arch=`expr "x$target" : 'x\([^=]*\)-'`
	platform=`expr "x$target" : 'x[^=]*-\(.*\)'`

	case "$arch" in
	i386|arm|avr32|ppc|sh|mips)
		;;
	*)
		quit "Unkown target architecture: $arch"
		;;
	esac

	host_name=`uname -s`
	case $host_name in
	CYGWIN*)
		case $arch in
		i386)    cross="i386-elf-" ;;
		arm)     cross="arm-elf-" ;;
		avr32)     cross="avr32-" ;;
		ppc)     cross="powerpc-eabi-" ;;
		sh)      cross="sh-elf-" ;;
		mips)    cross="mips-elf-" ;;
		esac
		;;
	esac
	cc="${cross}gcc"
}

setparm()
{
	echo "$1=$2"
	echo "$1=$2" >>$CONFIG_MK
	if [ "$2" = "n" ] ; then
		echo "#undef $1" >>$CONFIG_H
	else
		echo "#define $1 $2" >>$CONFIG_H
	fi
}

setgccoption()
{
	if $cc $1 -S -xc /dev/null -o /dev/null > /dev/null 2>&1; then
		echo "CONFIG_CFLAGS+= $1" >>$CONFIG_MK
	fi
}

parseconfig()
{
	while read line; do
		word=`expr "x$line" : 'x\(CONFIG_[A-Za-z0-9_=]*\)'`
		param=`expr "x$word" : 'x\([^=]*\)='`
		value=`expr "x$word" : 'x[^=]*=\([A-Za-z0-9]*\)'`
		if [ -n "$param" ] ; then
		    setparm "$param" "$value"
		fi
	done < $1
	echo "" >> $CONFIG_MK
}

main()
{
	setdefaults
	getoptions "$@"
	gettarget
	checkpath

	echo "Processing configuration files..."

	echo "#" > $CONFIG_MK
	echo "# Automatically generated file. Don't edit" >> $CONFIG_MK
	echo "#" >> $CONFIG_MK

	echo "/*" > $CONFIG_H
	echo " * Automatically generated file. Don't edit" >> $CONFIG_H
	echo " */" >> $CONFIG_H

	#
	# Generate configuration parameters
	#
	parseconfig $CONFIG_IN
	parseconfig $CMDBOX_IN

	#
	# Check arch/platform setting
	#
	echo "SRCDIR=$srcdir" >> $CONFIG_MK
	echo "ARCH=$arch" >> $CONFIG_MK
	echo "PLATFORM=$platform" >> $CONFIG_MK
	[ "x$cross" != x ] && echo "CROSS_COMPILE=$cross" >> $CONFIG_MK
	[ "x$nodebug" != x ] && echo "NDEBUG=1" >> $CONFIG_MK
	echo "" >> $CONFIG_MK

	#
	# Check gcc options
	#
	setgccoption "-fno-stack-protector"
	setgccoption "-Wno-variadic-macros"
}

main "$@"