#!/bin/sh

# bail out fast if we already have a cache file, otherwise building is far too slow!

MAKEFILE_DIR="$3/$4"
if test -f "${MAKEFILE_DIR}/makefiles/gmake/platform.vars"; then
	. "${MAKEFILE_DIR}/makefiles/gmake/platform.vars"
else

	# operating system and major, minor version, more should not be necessary

	UNAME_SYSTEM=`(uname -s) 2>/dev/null`
	UNAME_RELEASE=`(uname -r) 2>/dev/null`
	UNAME_VERSION=`(uname -v) 2>/dev/null`
	UNAME_MACHINE=`(uname -m) 2>/dev/null`

	case "$UNAME_SYSTEM.$UNAME_RELEASE" in
		Linux*)		PLATFORM=LINUX
				OS_MAJOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2`
				
				# LSB-system? Check for lsb-release
				if test -x /usr/bin/lsb_release; then
					dist=`/usr/bin/lsb_release -i | cut -f 2`
					rev=`/usr/bin/lsb_release -r | cut -f 2`
					case "$dist" in
						Ubuntu)
							LINUX_DIST='ubuntu'
							LINUX_REV=$rev
							;;
						
						Debian)
							LINUX_DIST='debian'
							LINUX_REV=`echo $rev | cut -f 1 -d.`
							;;
							
						SUSE*LINUX)
							LINUX_DIST='suse'
							LINUX_REV=`echo $rev | tr -s ' ' '\t' | cut -f 2 -d ' '`
							;;
							
						*)
							LINUX_DIST='unknown'
							LINUX_REV='unknown'
							;;
					esac
				else
					# try the older way with release files in /etc
					
					if test -f /etc/arch-release; then
						LINUX_DIST='arch'
						LINUX_REV='current'
						if test "$OS_MAJOR_VERSION" = "3"; then
							OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2 | cut -d - -f 1`
						fi
					elif test -f /etc/debian_version; then
						LINUX_DIST='debian'
						LINUX_REV=`cat /etc/debian_version | cut -d . -f 1`
					elif test -f /etc/slackware-version; then
						LINUX_DIST='slackware'
						LINUX_REV=`cat /etc/slackware-version | cut -d ' ' -f 2 | cut -d . -f 1,2`
					elif test -f /etc/redhat-release; then
						LINUX_DIST='redhat'
						LINUX_REV=`cat /etc/redhat-release | sed s/.*release\ // | sed s/\ .*// | cut -f 1 -d .`
					elif test -f /etc/fedora-release; then
						LINUX_DIST='redhat'
						LINUX_REV=`cat /etc/fedora-release | cut -f 3 -d ' '`
					elif test -f /etc/SuSE-release; then
						grep "SUSE Linux Enterprise Server" /etc/SuSE-release
						if test $? = 0; then
							LINUX_DIST='sles'
							LINUX_REV=`grep VERSION /etc/SuSE-release | cut -f 3 -d ' '`
						else
							LINUX_DIST='suse'
							LINUX_REV=`grep VERSION /etc/SuSE-release | cut -f 3 -d ' '`
						fi
					else
						LINUX_DIST='unknown'
						LINUX_REV='unknown'
					fi
				fi
				;;

		FreeBSD*)	PLATFORM=FREEBSD
				OS_MAJOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2 | cut -d - -f 1`
				;;
				
		OpenBSD*)	PLATFORM=OPENBSD
				OS_MAJOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2 | cut -d - -f 1`
				;;

		NetBSD*)	PLATFORM=NETBSD
				OS_MAJOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2`
				;;

		SunOS*)		PLATFORM=SUNOS
				OS_MAJOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $UNAME_RELEASE | cut -d . -f 2`
				;;

		CYGWIN_NT*)	PLATFORM=CYGWIN
				_tmp=`echo $UNAME_SYSTEM | cut -d - -f 2`
				OS_MAJOR_VERSION=`echo $_tmp | cut -d . -f 1`
				OS_MINOR_VERSION=`echo $_tmp | cut -d . -f 2`
				;;

		*)
				PLATFORM=UNKNOWN
				echo "Unknown platform '$UNAME_SYSTEM $UNAME_RELEASE'"
				exit 1
	esac

	# the architecture

	case "$UNAME_MACHINE" in
		i*86*)		ARCH=x86
				;;
		x86_64|amd64)	ARCH=x86_64
				;;
		sun4u)		ARCH=sun4u
				;;

		*)		ARCH=UNKNOWN
				echo "Unknown architecture '$UNAME_MACHINE'"
				exit 1
				
	esac

	# get last line, old 'tail' syntax and POSIX syntax, both exist out there
	if test "x${PLATFORM}" = "xSUNOS"; then
		TAIL1='tail -1'
	else
		TAIL1='tail -n 1'
	fi

	# the compiler and version

	# do we have ccache or distcc in CC, then check the compiler, not the wrapper
	CC=$2
	CC=`echo $CC | sed 's/distcc//g' | sed 's/ccache//g'`

	# what compiler do we have (we can't relly on it's name as it may be a cc link to the binary!)
	(( $CC -v 2>&1 | $TAIL1 ) | grep -i GCC ) 2>/dev/null 1>/dev/null
	if test $? = 0; then
		COMPILER='gcc'
	else
	#	( $CC -V 2>&1 | grep l_cproc_p ) >/dev/null
		( $CC -V 2>&1 | grep "Intel(R) C" | grep "Compiler" ) >/dev/null
		if test $? = 0; then
			COMPILER='icc'
		else
			( $CC -xhelp=readme | head -n 1 | grep 'Sun Studio' ) >/dev/null
			if test $? = 0; then
				COMPILER='spro'
			else
				COMPILER='unknown'
			fi
		fi
	fi

	# version of gcc (GNU C compiler)

	if test $COMPILER = "gcc"; then
		GCC_VERSION=`gcc -dumpversion`
		GCC_MAJOR_VERSION=`echo $GCC_VERSION | cut -d . -f 1`
		GCC_MINOR_VERSION=`echo $GCC_VERSION | cut -d . -f 2`
	fi

	# version of icc (Intel C compiler)

	if test $COMPILER = "icc"; then
		ICC_VERSION=`icc -dumpversion`
		ICC_MAJOR_VERSION=`echo $ICC_VERSION | cut -d . -f 1`
		ICC_MINOR_VERSION=`echo $ICC_VERSION | cut -d . -f 2`
	fi

	# version of spro (Sun Pro compiler, Sun Studio)

	if test $COMPILER = "spro"; then
		SPRO_VERSION=`$CC -xhelp=readme | head -n 1 | cut -d ' ' -f 3`
		SPRO_MAJOR_VERSION=`echo $SPRO_VERSION | cut -d : -f 1`
	fi

	# generate the makefile snippet with conditional variables
	# (conditional, so that users can overwrite them for instance
	# for cross-compilation)
	cat >"${MAKEFILE_DIR}/makefiles/gmake/platform.mk.vars" <<EOF
ARCH?=$ARCH
PLATFORM?=$PLATFORM
OS_MAJOR_VERSION?=$OS_MAJOR_VERSION
OS_MINOR_VERSION?=$OS_MINOR_VERSION
COMPILER?=$COMPILER
GCC_MAJOR_VERSION?=$GCC_MAJOR_VERSION
GCC_MINOR_VERSION?=$GCC_MINOR_VERSION
ICC_MAJOR_VERSION?=$ICC_MAJOR_VERSION
ICC_MINOR_VERSION?=$ICC_MINOR_VERSION
SPRO_MAJOR_VERSION?=$SPRO_MAJOR_VERSION
LINUX_DIST?=$LINUX_DIST
LINUX_REV?=$LINUX_REV
EOF

	# write the cache file (to protect against constant recomputations!)
	cat >"${MAKEFILE_DIR}/makefiles/gmake/platform.vars" <<EOF
ARCH=$ARCH
PLATFORM=$PLATFORM
OS_MAJOR_VERSION=$OS_MAJOR_VERSION
OS_MINOR_VERSION=$OS_MINOR_VERSION
COMPILER=$COMPILER
GCC_MAJOR_VERSION=$GCC_MAJOR_VERSION
GCC_MINOR_VERSION=$GCC_MINOR_VERSION
ICC_MAJOR_VERSION=$ICC_MAJOR_VERSION
ICC_MINOR_VERSION=$ICC_MINOR_VERSION
SPRO_MAJOR_VERSION=$SPRO_MAJOR_VERSION
LINUX_DIST=$LINUX_DIST
LINUX_REV=$LINUX_REV
EOF

fi

case "$1" in
	--platform)		echo $PLATFORM
				;;

	--os-major-version)	echo $OS_MAJOR_VERSION
				;;

	--os-minor-version)	echo $OS_MINOR_VERSION
				;;

	--arch)			echo $ARCH
				;;

	--compiler)		echo $COMPILER
				;;

	--gcc-major-version)	echo $GCC_MAJOR_VERSION
				;;

	--gcc-minor-version)	echo $GCC_MINOR_VERSION
				;;

	--icc-major-version)	echo $ICC_MAJOR_VERSION
				;;

	--icc-minor-version)	echo $ICC_MINOR_VERSION
				;;

	--spro-major-version)	echo $SPRO_MAJOR_VERSION
				;;

	*)			echo "unkown flag '$1' requested!"
				exit 1
esac