#!/bin/bash
# Copyright 2008-2010 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2

if [[ $1 == "--help" || $1 == "-h" ]] ; then
	cat <<-EOF
	Usage: emerge-wrapper [--target <chost>] <--init|commands for cross-emerge>

	emerge-wrapper is used in one of two ways:
	  - Use --init to setup cross-toolchain environment(s)
	  - Pass the command line through to cross-emerge
	EOF
	exit 0
fi

PREFIX="__PREFIX__"
# Enable this script to be manually installed while debugging
[[ ${PREFIX} == \_\_\P\R\E\F\I\X\_\_ ]] && PREFIX="/usr"

err() { echo "emerge-wrapper: $*" 1>&2; exit 1; }

emit_setup_warning()
{
	${setup_warning:-false} && return 0
	setup_warning=true
	echo "!!! WARNING - Cannot auto-configure CHOST ${CHOST}"
	echo "!!! You should edit ${conf}"
	echo "!!! by hand to complete your configuration"
}

cross_wrap_etc()
{
	[[ $1 == "-q" ]] || echo "${CHOST}: setting up cross basics in ${SYSROOT}/etc"

	setup_warning=false

	cp -a "${PREFIX}"/share/crossdev/etc ${SYSROOT}/     || return 1
	ln -sf /etc/make.globals ${SYSROOT}/etc/make.globals || return 1

	local conf=${SYSROOT}/etc/make.conf

	# Re-use existing CHOST->portage ARCH mapping code
	ARCH=$(
		inherit() { :; }
		. "${PORTDIR}"/eclass/toolchain-funcs.eclass
		tc-arch
	)
	[[ ${ARCH} == "unknown" ]] && emit_setup_warning

	# Now map out the non-standard EM values
	case ${ARCH} in
		amd64) E_MACHINE=X86_64 ;;
		hppa)  E_MACHINE=PARISC ;;
		ia64)  E_MACHINE=IA_64  ;;
		m68k)  E_MACHINE=68K    ;;
		*)     E_MACHINE=`echo ${ARCH} | tr '[:lower:]' '[:upper:]'` ;;
	esac
	E_MACHINE="EM_${E_MACHINE}"

	LIBC="__LIBC__"
	case ${CHOST} in
		*gnu*)    LIBC=glibc ;;
		*uclibc*) LIBC=uclibc ;;
		*)        emit_setup_warning ;;
	esac

	sed -i \
		-e "s:__LIBC__:${LIBC}:g" \
		-e "s:__E_MACHINE__:${E_MACHINE}:g" \
		-e "s:__ARCH__:${ARCH}:g" \
		-e "s:__CBUILD__:${CBUILD}:g" \
		"${conf}"
	[[ ${EM_MACHINE} == "EM_UNKNOWN" ]] \
		&& sed -i '/^E_MACHINE/s:^:#:' "${conf}"

	# Merge UCLIBC_CPU from env only
	local v
	for v in ${import_vars} UCLIBC_CPU ; do
		[[ -n ${!v} ]] && echo "${v}=\"${!v}\""
	done >> "${conf}"

	return 0
}

cross_wrap_bin()
{
	[[ $1 == "-q" ]] || echo "${CHOST}: Setting up symlinks"
	local wrapper
	for wrapper in emerge fix-root pkg-config ; do
		ln -sf cross-${wrapper} ${CHOST}-${wrapper}
	done
	# some people like their tab completion
	ln -sf cross-emerge emerge-${CHOST}
}

cross_wrap()
{
	SYSROOT=/usr/${CHOST}
	cross_wrap_bin "$@" || return $?
	if [[ -d ${SYSROOT} ]] && [[ ! -d ${SYSROOT}/etc ]] ; then
		cross_wrap_etc "$@"
	fi
	return $?
}

cross_init()
{
	cd "${0%/*}" || err "unable to cd to ${0%/*}"

	# Initialize env for just one target.  This is the automated behavior
	# when crossdev is setting things up for people.
	if [[ ${CHOST} != "wrapper" ]] ; then
		cross_wrap -q
		return $?
	fi

	# When called generically, blindly set up wrappers for all installed
	# toolchains.  This is more historical behavior and not really
	# recommended anymore ...
	[[ ${0##*/} != emerge-wrapper ]] && err "I wont understand things"

	for CHOST in `find /usr/lib/gcc -maxdepth 1 -mindepth 1 -type d` ; do
		CHOST=${CHOST##*/}
		[[ ${CHOST} == ${CBUILD} ]] && continue
		type -P -- ${CHOST}-gcc >/dev/null || continue
		cross_wrap
	done
}

# CBUILD must be the first thing we export, but might as well avoid
# running portageq multiple times ...
import_vars="PORTDIR DISTDIR PORTDIR_OVERLAY MAKEOPTS GENTOO_MIRRORS"
eval $(portageq envvar -v CBUILD ${import_vars})
export CBUILD

# Get default CHOST value from program name
CHOST=${0##*/}
CHOST=${CHOST%-emerge}
CHOST=${CHOST#emerge-}
export CHOST

if [[ $1 == "--target" ]] ; then
	CHOST=$2
	shift 2
fi

if [[ $1 == "--init" ]] ; then
	cross_init
	exit $?
fi

if [[ $CHOST == "wrapper" ]] ; then
	echo "After running this program with the --init option as root"
	echo "you can call it directly like emerge-wrapper --target CHOST <emerge options>"
	echo "or using the emerge-CHOST wrappers"
	exit 1
fi

type -P -- ${CHOST}-gcc >/dev/null || err "you need to 'crossdev $CHOST' first"

exec cross-emerge "$@"