# Copyright 1999-2003 Gentoo Technologies, Inc.
# Distributed under the terms of the GNU General Public License v2
# $Header: /var/cvsroot/gentoo-x86/eclass/flag-o-matic.eclass,v 1.38 2004/02/26 06:47:23 vapier Exp $
#
# Author Bart Verwilst <verwilst@gentoo.org>

ECLASS=flag-o-matic
INHERITED="$INHERITED $ECLASS"

#
#### filter-flags <flags> ####
# Remove particular flags from C[XX]FLAGS
# Matches only complete flags
#
#### append-flags <flags> ####
# Add extra flags to your current C[XX]FLAGS
#
#### replace-flags <orig.flag> <new.flag> ###
# Replace a flag by another one
#
#### replace-cpu-flags <new.cpu> <old.cpus> ###
# Replace march/mcpu flags that specify <old.cpus>
# with flags that specify <new.cpu>
#
#### is-flag <flag> ####
# Returns "true" if flag is set in C[XX]FLAGS
# Matches only complete a flag
#
#### strip-flags ####
# Strip C[XX]FLAGS of everything except known
# good options.
#
#### strip-unsupported-flags ####
# Strip C[XX]FLAGS of any flags not supported by
# installed version of gcc
#
#### get-flag <flag> ####
# Find and echo the value for a particular flag
#
#### replace-sparc64-flags ####
# Sets mcpu to v8 and uses the original value
# as mtune if none specified.
#
#### filter-mfpmath <math types> ####
# Remove specified math types from the fpmath specification
# If the user has -mfpmath=sse,386, running `filter-mfpmath sse`
# will leave the user with -mfpmath=386
#
#### append-ldflags ####
# Add extra flags to your current LDFLAGS
#
#### etexec-flags ####
# hooked function for hardened-gcc that appends 
# -yet_exec {C,CXX,LD}FLAGS when hardened-gcc is installed
# and a package is filtering -fPIC,-fpic, -fPIE, -fpie
#
#### fstack-flags ####
# hooked function for hardened-gcc that appends
# -yno_propolice to {C,CXX,LD}FLAGS when hardened-gcc is installed
# and a package is filtering -fstack-protector, -fstack-protector-all
#

# C[XX]FLAGS that we allow in strip-flags
setup-allowed-flags() {
	export ALLOWED_FLAGS="-O -O1 -O2 -mcpu -march -mtune -fstack-protector -pipe -g"
	case "${ARCH}" in
		mips)	ALLOWED_FLAGS="${ALLOWED_FLAGS} -mips1 -mips2 -mips3 -mips4 -mabi" ;;
		amd64)	ALLOWED_FLAGS="${ALLOWED_FLAGS} -fPIC" ;;
		alpha)	ALLOWED_FLAGS="${ALLOWED_FLAGS} -fPIC" ;;
		ia64)   ALLOWED_FLAGS="${ALLOWED_FLAGS} -fPIC" ;;
	esac

	# C[XX]FLAGS that we are think is ok, but needs testing
	# NOTE:  currently -Os have issues with gcc3 and K6* arch's
	export UNSTABLE_FLAGS="-Os -O3 -freorder-blocks -fprefetch-loop-arrays"
	return 0
}

filter-flags() {
	for x in "$@" ; do
		case "${x}" in
			-fPIC|-fpic|-fPIE|-fpie) etexec-flags;;
			-fstack-protector|-fstack-protector-all) fstack-flags;;
			*) ;;
		esac
	done

	# we do this fancy spacing stuff so as to not filter
	# out part of a flag ... we want flag atoms ! :D
	CFLAGS=" ${CFLAGS} "
	CXXFLAGS=" ${CXXFLAGS} "
	for x in "$@" ; do
		CFLAGS="${CFLAGS// ${x} / }"
		CXXFLAGS="${CXXFLAGS// ${x} / }"
	done
	CFLAGS="${CFLAGS:1:${#CFLAGS}-2}"
	CXXFLAGS="${CXXFLAGS:1:${#CXXFLAGS}-2}"
	return 0
}

append-flags() {
	export CFLAGS="${CFLAGS} $@"
	export CXXFLAGS="${CXXFLAGS} $@"
	[ "`is-flag -fno-stack-protector`" -o "`is-flag -fno-stack-protector-all`" ] && fstack-flags
	return 0
}

replace-flags() {
	# we do this fancy spacing stuff so as to not filter
	# out part of a flag ... we want flag atoms ! :D
	CFLAGS=" ${CFLAGS} "
	CXXFLAGS=" ${CXXFLAGS} "
	CFLAGS="${CFLAGS// ${1} / ${2} }"
	CXXFLAGS="${CXXFLAGS// ${1} / ${2} }"
	CFLAGS="${CFLAGS:1:${#CFLAGS}-2}"
	CXXFLAGS="${CXXFLAGS:1:${#CXXFLAGS}-2}"
	return 0
}

replace-cpu-flags() {
	local newcpu="$1" ; shift
	local oldcpu=""
	for oldcpu in "$@" ; do
		replace-flags -march=${oldcpu} -march=${newcpu}
		replace-flags -mcpu=${oldcpu} -mcpu=${newcpu}
		replace-flags -mtune=${oldcpu} -mtune=${newcpu}
	done
	return 0
}

is-flag() {
	for x in ${CFLAGS} ${CXXFLAGS} ; do
		if [ "${x}" == "$1" ] ; then
			echo true
			return 0
		fi
	done
	return 1
}

filter-mfpmath() {
	# save the original -mfpmath flag
	local orig_mfpmath="`get-flag -mfpmath`"
	# get the value of the current -mfpmath flag
	local new_math=" `get-flag mfpmath | tr , ' '` "
	# figure out which math values are to be removed
	local prune_math=""
	for prune_math in "$@" ; do
		new_math="${new_math/ ${prune_math} / }"
	done
	new_math="`echo ${new_math:1:${#new_math}-2} | tr ' ' ,`"

	if [ -z "${new_math}" ] ; then
		# if we're removing all user specified math values are
		# slated for removal, then we just filter the flag
		filter-flags ${orig_mfpmath}
	else
		# if we only want to filter some of the user specified
		# math values, then we replace the current flag
		replace-flags ${orig_mfpmath} -mfpmath=${new_math}
	fi
	return 0
}

strip-flags() {
	setup-allowed-flags

	local NEW_CFLAGS=""
	local NEW_CXXFLAGS=""

	# Allow unstable C[XX]FLAGS if we are using unstable profile ...
	if [ `has ~${ARCH} ${ACCEPT_KEYWORDS}` ] ; then
		[ `use debug` ] && einfo "Enabling the use of some unstable flags"
		ALLOWED_FLAGS="${ALLOWED_FLAGS} ${UNSTABLE_FLAGS}"
	fi

	set -f

	for x in ${CFLAGS}
	do
		for y in ${ALLOWED_FLAGS}
		do
			flag=${x%%=*}
			if [ "${flag%%${y}}" = "" ]
			then
				NEW_CFLAGS="${NEW_CFLAGS} ${x}"
				break
			fi
		done
	done

	for x in ${CXXFLAGS}
	do
		for y in ${ALLOWED_FLAGS}
		do
			flag=${x%%=*}
			if [ "${flag%%${y}}" = "" ]
			then
				NEW_CXXFLAGS="${NEW_CXXFLAGS} ${x}"
				break
			fi
		done
	done

	# In case we filtered out all optimization flags fallback to -O2
	if [ "${CFLAGS/-O}" != "${CFLAGS}" -a "${NEW_CFLAGS/-O}" = "${NEW_CFLAGS}" ]; then
		NEW_CFLAGS="${NEW_CFLAGS} -O2"
	fi
	if [ "${CXXFLAGS/-O}" != "${CXXFLAGS}" -a "${NEW_CXXFLAGS/-O}" = "${NEW_CXXFLAGS}" ]; then
		NEW_CXXFLAGS="${NEW_CXXFLAGS} -O2"
	fi

	set +f

	[ `use debug` ] \
		&& einfo "CFLAGS=\"${NEW_CFLAGS}\"" \
		&& einfo "CXXFLAGS=\"${NEW_CXXFLAGS}\""

	export CFLAGS="${NEW_CFLAGS}"
	export CXXFLAGS="${NEW_CXXFLAGS}"
	return 0
}

test_flag() {
	if gcc -S -xc "$@" -o /dev/null /dev/null >/dev/null 2>&1; then
		echo "$@"
		return 0
	fi
	return 1
}

strip-unsupported-flags() {
	for x in ${CFLAGS} ; do
		NEW_CFLAGS=${NEW_CFLAGS}" ""`test_flag ${x}`"
	done
	for x in ${CXXFLAGS} ; do
		NEW_CXXFLAGS=${NEW_CXXFLAGS}" ""`test_flag ${x}`"
	done

	export CFLAGS="${NEW_CFLAGS}"
	export CXXFLAGS="${NEW_CXXFLAGS}"
}

get-flag() {
	# this code looks a little flaky but seems to work for
	# everything we want ...
	# for example, if CFLAGS="-march=i686":
	# `get-flags -march` == "-march=i686"
	# `get-flags march` == "i686"
	local findflag="$1"
	for f in ${CFLAGS} ${CXXFLAGS} ; do
		if [ "${f/${findflag}}" != "${f}" ] ; then
			echo "${f/-${findflag}=}"
			return 0
		fi
	done
	return 1
}

replace-sparc64-flags() {
	local SPARC64_CPUS="ultrasparc v9"

 	if [ "${CFLAGS/mtune}" != "${CFLAGS}" ]
	then
		for x in ${SPARC64_CPUS}
		do
			CFLAGS="${CFLAGS/-mcpu=${x}/-mcpu=v8}"
		done
 	else
	 	for x in ${SPARC64_CPUS}
		do
			CFLAGS="${CFLAGS/-mcpu=${x}/-mcpu=v8 -mtune=${x}}"
		done
	fi
	
 	if [ "${CXXFLAGS/mtune}" != "${CXXFLAGS}" ]
	then
		for x in ${SPARC64_CPUS}
		do
			CXXFLAGS="${CXXFLAGS/-mcpu=${x}/-mcpu=v8}"
		done
	else
	 	for x in ${SPARC64_CPUS}
		do
			CXXFLAGS="${CXXFLAGS/-mcpu=${x}/-mcpu=v8 -mtune=${x}}"
		done
	fi
}

append-ldflags() {
	LDFLAGS="${LDFLAGS} $@"
	return 0
}

etexec-flags() {
	has_version sys-devel/hardened-gcc
	if [ $? == 0 ] ; then
		if [ "`is-flag -yet_exec`" != "true" ]; then
			debug-print ">>> appending flags -yet_exec"
			append-flags -yet_exec
			append-ldflags -yet_exec
		fi
	fi
}

fstack-flags() {
	has_version sys-devel/hardened-gcc
	if [ $? == 0 ] ; then
		if [ "`is-flag -yno_propolice`" != "true" ]; then
			debug-print ">>> appending flags -yno_propolice"
			append-flags -yno_propolice
			append-ldflags -yno_propolice
		fi
	fi
}