# Copyright 1999-2017 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$

# Robin H. Johnson <robbat2@gentoo.org>, 12 Nov 2007:
# This still needs major work.
# But it is significently better than the previous version.
# In that it will now build on biarch systems, such as ppc64-32ul.

# NOTES:
# ======
# We need to bring in the kernel sources seperately
# Because they have to be configured in a way that differs from the copy in
# /usr/src/. The sys-kernel/linux-headers are too stripped down to use
# unfortunately.
# This will be able to go away once the klibc author updates his code
# to build again the headers provided by the kernel's 'headers_install' target.

EAPI=6
K_TARBALL_SUFFIX="xz"

inherit eutils toolchain-funcs flag-o-matic

DESCRIPTION="A minimal libc subset for use with initramfs"
HOMEPAGE="http://www.zytor.com/mailman/listinfo/klibc/ https://www.kernel.org/pub/linux/libs/klibc/"
KV_MAJOR="4" KV_MINOR="x" KV_SUB="4"
PKV_EXTRA=""
if [[ ${PKV_EXTRA} ]]; then
	if [[ ${KV_MAJOR} == 2 ]]; then
		PKV="${KV_MAJOR}.${KV_MINOR}.$((${KV_SUB}+1))-${PKV_EXTRA}"
	else
		PKV="${KV_MAJOR}.$((${KV_SUB}+1))-${PKV_EXTRA}"
	fi
	PATCH_URI="mirror://kernel/linux/kernel/v${KV_MAJOR}.${KV_MINOR}/patch-${PKV}.${K_TARBALL_SUFFIX}"
fi
if [[ ${KV_MAJOR} == 2 ]]; then
	OKV="${KV_MAJOR}.${KV_MINOR}.${KV_SUB}"
else
	OKV="${KV_MAJOR}.${KV_SUB}"
fi
KERNEL_URI="
	mirror://kernel/linux/kernel/v${KV_MAJOR}.${KV_MINOR}/linux-${OKV}.tar.${K_TARBALL_SUFFIX}
	mirror://kernel/linux/kernel/v${KV_MAJOR}.${KV_MINOR}/testing/linux-${OKV}.tar.${K_TARBALL_SUFFIX}"
DEBIAN_PV=2.0.4
DEBIAN_PR=9
DEBIAN_A="${PN}_${DEBIAN_PV}-${DEBIAN_PR}.debian.tar.xz"
SRC_URI="
	mirror://kernel/linux/libs/klibc/${PV:0:3}/${P}.tar.${K_TARBALL_SUFFIX}
	mirror://debian/pool/main/k/klibc/${DEBIAN_A}
	${PATCH_URI}
	${KERNEL_URI}"

LICENSE="|| ( GPL-2 LGPL-2 )"
KEYWORDS="~alpha amd64 ~arm ~ia64 -mips ~ppc ~ppc64 ~sparc x86"
SLOT="0"
IUSE="debug test custom-cflags"

DEPEND="dev-lang/perl"
RDEPEND="${DEPEND}"

KS="${WORKDIR}/linux-${OKV}"

# Klibc has no PT_GNU_STACK support, so scanning for execstacks is moot
QA_EXECSTACK="*"
# Do not strip
RESTRICT="strip"

kernel_asm_arch() {
	a="${1:${ARCH}}"
	case ${a} in
		# Merged arches
		x86) echo i386 ;; # for build on x86 userspace & 64bit kernel
		amd64) echo x86 ;;
		ppc*) echo powerpc ;;
		# Non-merged
		alpha|arm|arm64|ia64|m68k|mips|sh|sparc*) echo ${1} ;;
		*) die "TODO: Update the code for your asm-ARCH symlink" ;;
	esac
}

# For a given Gentoo ARCH,
# specify the kernel defconfig most relevant
kernel_defconfig() {
	a="${1:${ARCH}}"
	# most, but not all arches have a sanely named defconfig
	case ${a} in
		ppc64) echo ppc64_defconfig ;;
		ppc) echo pmac32_defconfig ;;
		sh*) die "TODO: Your arch is not supported by the klibc ebuild. Please suggest a defconfig in a bug." ;;
		*) echo defconfig ;;
	esac
}

src_unpack() {
	unpack linux-${OKV}.tar.${K_TARBALL_SUFFIX} ${P}.tar.${K_TARBALL_SUFFIX} ${DEBIAN_A}
}

PATCHES=(
	# Build interp.o with EXTRA_KLIBCAFLAGS (.S source)
	"${FILESDIR}"/${PN}-1.4.11-interp-flags.patch
	# Fix usage of -s, bug #201006
	"${FILESDIR}"/klibc-1.5.7-strip-fix-dash-s.patch
	# The inline definition from sys/stat.h does not seem to get used
	# So just copy it to make this compile for now
	"${FILESDIR}"/klibc-2.0.2-mkfifo.patch
	# Newer kernels have some headers in the uapi dir
	"${FILESDIR}"/klibc-2.0.3-kernel-uapi.patch
)

src_prepare() {
	[[ ${PKV} ]] && eapply "${DISTDIR}"/patch-${PKV}.${K_TARBALL_SUFFIX}

	# Symlink /usr/src/linux to ${S}/linux
	ln -snf "${KS}" linux
	#ln -snf "/usr" linux

	# Borrow the debian fixes too
	for p in $(<"${WORKDIR}"/debian/patches/series) ; do
		PATCHES+=( "${WORKDIR}/debian/patches/${p}" )
	done

	default
}

# klibc has it's own ideas of arches
# They reflect userspace strictly.
# This functions maps from a Gentoo ARCH, to an arch that klibc expects
# Look at klibc-${S}/usr/klibc/arch for a list of these arches
klibc_arch() {
	a="${1:${ARCH}}"
	case ${a} in
		amd64) echo x86_64;;
		mips) die 'TODO: Use the $ABI' ;;
		x86) echo i386;;
		*) echo ${a} ;;
	esac
}

src_compile() {
	local myargs="all"
	local myARCH="${ARCH}" myABI="${ABI}"
	# TODO: For cross-compiling
	# You should set ARCH and ABI here
	CC="$(tc-getCC)"
	LD="$(tc-getLD)"
	HOSTCC="$(tc-getBUILD_CC)"
	HOSTLD="$(tc-getBUILD_LD)"
	KLIBCARCH="$(klibc_arch ${ARCH})"
	KLIBCASMARCH="$(kernel_asm_arch ${ARCH})"
	libdir="$(get_libdir)"
	# This should be the defconfig corresponding to your userspace!
	# NOT your kernel. PPC64-32ul would choose 'ppc' for example.
	defconfig=$(kernel_defconfig ${ARCH})
	unset ABI ARCH # Unset these, because they interfere
	unset KBUILD_OUTPUT # we are using a private copy

	cd "${KS}"
	emake ${defconfig} CC="${CC}" HOSTCC="${HOSTCC}" ARCH="${KLIBCASMARCH}" || die "No defconfig"
	if [[ "${KLIBCARCH/arm}" != "${KLIBCARCH}" ]] && \
	   [[ "${CHOST/eabi}" != "${CHOST}" ]]; then
		# The delete and insert are seperate statements
		# so that they are reliably used.
		sed -i \
		-e '/CONFIG_AEABI/d' \
		-e '1iCONFIG_AEABI=y' \
		-e '/CONFIG_OABI_COMPAT/d' \
		-e '1iCONFIG_OABI_COMPAT=y' \
		-e '1iCONFIG_ARM_UNWIND=y' \
		"${KS}"/.config \
		"${S}"/defconfig
	fi
	emake prepare CC="${CC}" HOSTCC="${HOSTCC}" ARCH="${KLIBCASMARCH}" || die "Failed to prepare kernel sources for header usage"

	cd "${S}"

	use debug && myargs="${myargs} V=1"
	use test && myargs="${myargs} test"
	append-ldflags -z noexecstack
	append-flags -nostdlib

	emake \
		EXTRA_KLIBCAFLAGS="-Wa,--noexecstack" \
		EXTRA_KLIBCLDFLAGS="-z noexecstack" \
		HOSTLDFLAGS="-z noexecstack" \
		KLIBCOPTFLAGS='-nostdlib' \
		HOSTCC="${HOSTCC}" CC="${CC}" \
		HOSTLD="${HOSTLD}" LD="${LD}" \
		INSTALLDIR="/usr/${libdir}/klibc" \
		KLIBCARCH=${KLIBCARCH} \
		KLIBCASMARCH=${KLIBCASMARCH} \
		SHLIBDIR="/${libdir}" \
		libdir="/usr/${libdir}" \
		mandir="/usr/share/man" \
		T="${T}" \
		$(use custom-cflags || echo SKIP_)HOSTCFLAGS="${CFLAGS}" \
		$(use custom-cflags || echo SKIP_)HOSTLDFLAGS="${LDFLAGS}" \
		$(use custom-cflags || echo SKIP_)KLIBCOPTFLAGS="${CFLAGS}" \
		${myargs} || die "Compile failed!"

		#SHLIBDIR="/${libdir}" \

	ARCH="${myARCH}" ABI="${myABI}"
}

src_install() {
	local myargs
	local myARCH="${ARCH}" myABI="${ABI}"
	# TODO: For cross-compiling
	# You should set ARCH and ABI here
	CC="$(tc-getCC)"
	HOSTCC="$(tc-getBUILD_CC)"
	KLIBCARCH="$(klibc_arch ${ARCH})"
	KLIBCASMARCH="$(kernel_asm_arch ${ARCH})"
	libdir="$(get_libdir)"
	# This should be the defconfig corresponding to your userspace!
	# NOT your kernel. PPC64-32ul would choose 'ppc' for example.
	defconfig=$(kernel_defconfig ${ARCH})

	use debug && myargs="${myargs} V=1"

	local klibc_prefix
	if tc-is-cross-compiler ; then
		klibc_prefix=$("${S}/klcc/${KLIBCARCH}-klcc" -print-klibc-prefix)
	else
		klibc_prefix=$("${S}/klcc/klcc" -print-klibc-prefix)
	fi

	unset ABI ARCH # Unset these, because they interfere
	unset KBUILD_OUTPUT # we are using a private copy

	emake \
		EXTRA_KLIBCAFLAGS="-Wa,--noexecstack" \
		EXTRA_KLIBCLDFLAGS="-z noexecstack" \
		HOSTLDFLAGS="-z noexecstack" \
		KLIBCOPTFLAGS='-nostdlib' \
		HOSTCC="${HOSTCC}" CC="${CC}" \
		HOSTLD="${HOSTLD}" LD="${LD}" \
		INSTALLDIR="/usr/${libdir}/klibc" \
		INSTALLROOT="${D}" \
		KLIBCARCH=${KLIBCARCH} \
		KLIBCASMARCH=${KLIBCASMARCH} \
		SHLIBDIR="/${libdir}" \
		libdir="/usr/${libdir}" \
		mandir="/usr/share/man" \
		T="${T}" \
		$(use custom-cflags || echo SKIP_)HOSTCFLAGS="${CFLAGS}" \
		$(use custom-cflags || echo SKIP_)HOSTLDFLAGS="${LDFLAGS}" \
		$(use custom-cflags || echo SKIP_)KLIBCOPTFLAGS="${CFLAGS}" \
		${myargs} \
		install || die "Install failed!"

		#SHLIBDIR="/${libdir}" \

	# klibc doesn't support prelinking, so we need to mask it
	cat > "${T}/70klibc" <<-EOF
		PRELINK_PATH_MASK="/usr/${libdir}/klibc"
	EOF

	doenvd "${T}"/70klibc

	# Fix the permissions (bug #178053) on /usr/${libdir}/klibc/include
	# Actually I have no idea, why the includes have those weird-ass permissions
	# on a particular system, might be due to inherited permissions from parent
	# directory
	# NOTE: This totally violates sandbox <asturm@gentoo.org>
	# find "${D}"/usr/${libdir}/klibc/include | xargs chmod o+rX
	find "${D}"/usr/${libdir}/klibc/include -type f \
		\( -name '.install' -o -name '..install.cmd' \) -delete || die

	# Hardlinks becoming copies
	for x in gunzip zcat ; do
		rm -f "${D}/${klibc_prefix}/bin/${x}"
		dosym gzip "${klibc_prefix}/bin/${x}"
	done

	# Restore now, so we can use the tc- functions
	ARCH="${myARCH}" ABI="${myABI}"
	if ! tc-is-cross-compiler ; then
		cd "${S}"
		insinto /usr/share/aclocal
		doins contrib/klibc.m4

		dodoc README usr/klibc/CAVEATS
		docinto gzip; dodoc usr/gzip/README
	fi

	# Fix up the symlink
	# Mainly for merged arches
	linkname="${D}/usr/${libdir}/klibc/include/asm"
	if [ -L "${linkname}" ] && [ ! -e "${linkname}" ] ; then
		ln -snf asm-${KLIBCASMARCH} "${linkname}"
	fi
}

pkg_preinst() {
	rm -rf ${EROOT}/usr/lib/klibc/include/{asm,asm-generic,linux}
}

src_test() {
	if ! tc-is-cross-compiler ; then
		cd "${S}"/usr/klibc/tests
		ALL_TESTS="$(ls *.c |sed 's,\.c$,,g')"
		BROKEN_TESTS="fcntl fnmatch testrand48"
		failed=0
		for t in $ALL_TESTS ; do
			if has $t $BROKEN_TESTS ; then
				echo "=== $t SKIP"
			else
				echo -n "=== $t "
				./$t </dev/null >/dev/null
				rc=$?
				if [ $rc -eq 0 ]; then
					echo PASS
				else
					echo FAIL
					failed=1
				fi
			fi
		done
		[ $failed -ne 0 ] && die "Some tests failed."
	fi
}