# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: /var/cvsroot/gentoo-x86/dev-lang/ghc/ghc-6.4.ebuild,v 1.1 2005/03/11 16:30:24 kosmikus Exp $

# THIS IS AN UNOFFICIAL EBUILD. PLEASE CONTACT kosmikus@gentoo.org DIRECTLY
# IF YOU EXPERIENCE PROBLEMS. PLEASE DO NOT WRITE TO GENTOO-MAILING LISTS
# AND DON'T FILE ANY BUGS IN BUGZILLA ABOUT THIS BUILD.

GHC_REPOSITORY="http://darcs.haskell.org/ghc-6.8"
EDARCS_REPOSITORY="${GHC_REPOSITORY}/ghc"

inherit base eutils flag-o-matic darcs ghc-package

DESCRIPTION="The Glasgow Haskell Compiler"
HOMEPAGE="http://www.haskell.org/ghc/"

LICENSE="BSD"
SLOT="0"
KEYWORDS="~alpha ~amd64 ~hppa ~ia64 ~ppc ~ppc64 ~sparc ~x86 ~x86-fbsd"
IUSE="doc ghcquickbuild"

RDEPEND="
	!dev-lang/ghc-bin
	>=sys-devel/gcc-2.95.3
	>=sys-devel/binutils-2.17
	>=dev-lang/perl-5.6.1
	>=dev-libs/gmp-4.1
	>=sys-libs/readline-4.2"

# ghc cannot usually be bootstrapped using later versions ...
DEPEND="${RDEPEND}
	<dev-lang/ghc-6.8
	>=dev-haskell/happy-1.16
	>=dev-haskell/alex-2.1
	doc? (  ~app-text/docbook-xml-dtd-4.2
			app-text/docbook-xsl-stylesheets
			>=dev-libs/libxslt-1.1.2
			>=dev-haskell/haddock-0.8 )"

# The following function fetches each of the sub-repositories that
# ghc requires.
fetch_pkg() {
	local EDARCS_REPOSITORY EDARCS_LOCALREPO
	EDARCS_REPOSITORY="${GHC_REPOSITORY}/packages/$1"
	EDARCS_LOCALREPO="ghc/libraries/$1"
	darcs_fetch
}

append-ghc-cflags() {
	local flag compile assemble link
	for flag in $*; do
		case ${flag} in
			compile)	compile="yes";;
			assemble)	assemble="yes";;
			link)		link="yes";;
			*)
				[[ ${compile}  ]] && GHC_CFLAGS="${GHC_CFLAGS} -optc${flag}"
				[[ ${assemble} ]] && GHC_CFLAGS="${GHC_CFLAGS} -opta${flag}"
				[[ ${link}     ]] && GHC_CFLAGS="${GHC_CFLAGS} -optl${flag}";;
		esac
	done
}

ghc_setup_cflags() {
	# We need to be very careful with the CFLAGS we ask ghc to pass through to
	# gcc. There are plenty of flags which will make gcc produce output that
	# breaks ghc in various ways. The main ones we want to pass through are
	# -mcpu / -march flags. These are important for arches like alpha & sparc.
	# We also use these CFLAGS for building the C parts of ghc, ie the rts.
	strip-flags
	strip-unsupported-flags
	filter-flags -fPIC

	GHC_CFLAGS=""
	for flag in ${CFLAGS}; do
		case ${flag} in

			# Ignore extra optimisation (ghc passes -O to gcc anyway)
			# -O2 and above break on too many systems
			-O*) ;;

			# Arch and ABI flags are what we're really after
			-m*) append-ghc-cflags compile assemble ${flag};;

			# Debugging flags don't help either. You can't debug Haskell code
			# at the C source level and the mangler discards the debug info.
			-g*) ;;

			# Ignore all other flags, including all -f* flags
		esac
	done

	# hardened-gcc needs to be disabled, because the mangler doesn't accept
	# its output.
	gcc-specs-pie && append-ghc-cflags compile link	-nopie
	gcc-specs-ssp && append-ghc-cflags compile		-fno-stack-protector

	# We also add -Wa,--noexecstack to get ghc to generate .o files with
	# non-exectable stack. This it a hack until ghc does it itself properly.
	append-ghc-cflags assemble		"-Wa,--noexecstack"
}

src_unpack() {
	# get main GHC darcs repo
	darcs_fetch
	for pkg in $(cat "${EDARCS_TOP_DIR}/${EDARCS_LOCALREPO}/libraries/core-packages"); do
		fetch_pkg "${pkg}"
	done
	# copy everything
	darcs_src_unpack
	ghc_setup_cflags

	# Modify the ghc driver script to use GHC_CFLAGS
	echo "SCRIPT_SUBST_VARS += GHC_CFLAGS" >> "${S}/driver/ghc/Makefile"
	echo "GHC_CFLAGS = ${GHC_CFLAGS}"      >> "${S}/driver/ghc/Makefile"
	sed -i -e 's|$TOPDIROPT|$TOPDIROPT $GHC_CFLAGS|' "${S}/driver/ghc/ghc.sh"
}

src_compile() {
	# darcs checkout requires to run this
	sh boot

	# initialize build.mk
	echo '# Gentoo changes' > mk/build.mk

	# We also need to use the GHC_CFLAGS flags when building ghc itself
	echo "SRC_HC_OPTS+=${GHC_CFLAGS}" >> mk/build.mk
	echo "SRC_CC_OPTS+=${CFLAGS} -Wa,--noexecstack" >> mk/build.mk

	# The settings that give you the fastest complete GHC build are these:
	if use ghcquickbuild; then
		echo "SRC_HC_OPTS     = -H64m -Onot -fasm" >> mk/build.mk
		echo "GhcStage1HcOpts = -O -fasm" >> mk/build.mk
		echo "GhcStage2HcOpts = -Onot -fasm" >> mk/build.mk
		echo "GhcLibHcOpts    = -Onot -fasm" >> mk/build.mk
		echo "GhcLibWays      =" >> mk/build.mk
		echo "SplitObjs       = NO" >> mk/build.mk
	fi
	# However, note that the libraries are built without optimisation, so
	# this build isn't very useful. The resulting compiler will be very
	# slow. On a 4-core x86 machine using MAKEOPTS="-j10", this build was
	# timed at less than 8 minutes.

	# determine what to do with documentation
	if use doc; then
		echo XMLDocWays="html" >> mk/build.mk
	else
		echo XMLDocWays="" >> mk/build.mk
		# needed to prevent haddock from being called
		echo NO_HADDOCK_DOCS=YES >> mk/build.mk
	fi

	# circumvent a very strange bug that seems related with ghc producing too much
	# output while being filtered through tee (e.g. due to portage logging)
	# reported as bug #111183
	echo "SRC_HC_OPTS+=-fno-warn-deprecations" >> mk/build.mk

	# GHC build system knows to build unregisterised on alpha and hppa,
	# but we have to tell it to build unregisterised on some other arches
	if use ppc64 || use sparc; then
		echo "GhcUnregisterised=YES" >> mk/build.mk
		echo "GhcWithNativeCodeGen=NO" >> mk/build.mk
		echo "GhcWithInterpreter=NO" >> mk/build.mk
		echo "SplitObjs=NO" >> mk/build.mk
		echo "GhcRTSWays := debug" >> mk/build.mk
		echo "GhcNotThreaded=YES" >> mk/build.mk
	fi

	econf || die "econf failed"

	emake all || die "make failed"
}

src_install () {
	local insttarget

	insttarget="install"
	use doc && insttarget="${insttarget} install-docs"

	emake -j1 ${insttarget} \
		DESTDIR="${D}" \
		|| die "make ${insttarget} failed"

	#need to remove ${D} from ghcprof script
	# TODO: does this actually work?
	sed -i -e 's:$FPTOOLS_TOP_ABS:#$FPTOOLS_TOP_ABS:' "${D}/usr/bin/ghcprof"

	#rename non-version-specific files
	nonvers=$(find -path "./*" -and -not -path "*${PV}*")
	nondef=""
	for f in ${nonvers}; do
		f=$(basename ${f})
		mv ${f} ${f}-darcs
		if test -e /usr/bin/${f}; then
			if test -L /usr/bin/${f} -a -e /usr/bin/${f}-darcs; then
				if diff -q "/usr/bin/${f}" "/usr/bin/${f}-darcs" > /dev/null; then
					# link seems to be okay, recreate to keep
					einfo "recreating link /usr/bin/${f} -> /usr/bin/${f}-darcs"
					dosym /usr/bin/${f}-darcs /usr/bin/{f}
					continue
				fi
			fi
			einfo "did not touch existing file /usr/bin/${f}"
			# presumably not our file, will not be unmerged
			nondef="${nondef} /usr/bin/${f}"
		else
			# interestingly, the file in question does not yet exist ...
			einfo "creating new link /usr/bin/${f} -> /usr/bin/${f}-darcs"
			dosym /usr/bin/${f}-darcs /usr/bin/${f}
		fi
	done
	if test -n "${nondef}"; then
		elog "If you want to make the Darcs version of GHC the default version,"
		elog "you should create the following symbolic links:"
		for f in ${nondef}; do
			einfo "   ln -s ${f}-darcs /usr/bin/${f}"
		done
		elog "Note that this is optional."
	fi

	cd "${S}"
	dodoc README ANNOUNCE LICENSE VERSION
}