#!/bin/sh
#
# Copyright (c) 2015 Antti Kantee.  All Rights Reserved.
# Copyright (c) 2015 Martin Lucina.  All Rights Reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#

_RUMPBAKE_VERSION=20160209

#
# rumprun-bake: script for final stage linking ("baking") of a unikernel image
#

unset runcmd
unset CONF
unset CFGFILE

if [ "$(basename $0)" = "rumpbake" ]; then
	echo '>>'
	echo '>> name "rumpbake" is deprecated.  use rumprun-bake instead'
	echo '>> (waiting 5s for you to see this)'
	echo '>>'
	sleep 5
fi

if [ "${RUMPRUN_WARNING_STFU}" != 'please' ]; then
	exec 3>&1 1>&2
	echo
	echo !!!
	echo !!! NOTE: rumprun-bake is experimental. syntax may change in the future
	echo !!!
	echo
	exec 1>&3 3>&-
fi

_die()
{

	echo ">> ERROR: $*"
	exit 1
}

#
# configuration management
#

_filter ()
{
	local filtee vname tmplist

	filtee=$1
	vname=$2
	for x in $(eval echo \${${vname}}); do
		[ "${filtee}" = "${x}" ] || tmplist="${tmplist} ${x}"
	done

	eval ${vname}="\${tmplist}"
}

_haveconf ()
{

	for x in ${ALLCONFIGS}; do
		[ "${x}" != "${1}" ] || return
	done
	_die "config \"${1}\" not found (${CFGFILE})"
}

_nothaveconf ()
{

	for x in ${ALLCONFIGS}; do
		[ "${x}" != "${1}" ] \
		    || _die "config ${1} already exists (${CFGFILE})"
	done
}

# Implement "sort | uniq" ourselves so that we don't completely
# screw up the order of the arguments.  not 100% sure it matters, but it's
# easy enough.  Also, notably, doing it locally is ~50% faster (which
# starts to matter when you have enough configs).
_uniq ()
{
	local listname newlist

	listname=$1
	shift || _die need listname for _uniq

	eval _UNIQREMAINING=\${$listname}
	set -- ${_UNIQREMAINING}
	while [ $# -gt 0 ]; do
		newlist="${newlist} $1"
		_filter $1 _UNIQREMAINING
		set -- ${_UNIQREMAINING}
	done
	eval ${listname}=\${newlist}
}

ALLCONFIGS=
version ()
{

	[ "${1}" = "${_RUMPBAKE_VERSION}" ] \
	    || _die ${CFGFILE} mismatch: expect ${_RUMPBAKE_VERSION}, got \"$1\"
	_VERSOK=true
}

conf ()
{

	if ! echo ${1} | egrep -q '^(xen|hw|sel4)?_'; then
		_die "conf: invalid \"$1\" (${CFGFILE})"
	fi
	CONF=$1
}

fnoc ()
{

	unset CONF
}

create ()
{

	[ -n "$*" ] || _die "create: need description (${CFGFILE})"

	_nothaveconf ${CONF}

	ALLCONFIGS="${ALLCONFIGS} ${CONF}"
	eval CONFDESCR_${CONF}=\"${*}\"
}

assimilate ()
{
	local from

	_haveconf ${CONF}

	for from; do
		_haveconf ${from}
		eval CONFIG_${CONF}=\"\${CONFIG_${CONF}} \${CONFIG_${from}}\"
	done
}

nuke ()
{

	[ $# -eq 0 ] || _die "nuke: wrong number of args (${CFGFILE})"
	_haveconf ${CONF}
	_filter ${CONF} ALLCONFIGS
}

add ()
{

	_haveconf ${CONF}
	eval CONFIG_${CONF}=\"\${CONFIG_${CONF}} $@\"
}

remove ()
{
	local compvar

	_haveconf ${CONF}

	compvar=CONFIG_${CONF}
	for x; do
		_filter ${x} ${compvar}
	done
}

# debug routine
debugdump ()
{

	_haveconf ${CONF}

	_uniq CONFIG_${CONF}
	eval echo \${CONFIG_${CONF}}
}

_usage ()
{
	cat <<EOM
rumprun-bake version: ${_RUMPBAKE_VERSION}

usage:	rumprun-bake [-c conffile ...] list
	rumprun-bake [-c conffile ...] [-m cmd ...] describe config
	rumprun-bake [-c conffile ...] [-m cmd ...] config out in [in ...]

"list" outputs available configs.

"describe" outputs details for the given config.

Final usage creates a unikernel image:
	config	: rumprun board configuration to use.
	output	: output file name for the unikernel image.
	input	: executable(s) to bake.
EOM
	exit 1
}

_nuketmpdir ()
{

	nukeme="${TMPDIR}"
	TMPDIR=''
	rm -rf ${nukeme}
}

_readconfig ()
{
	local x

	CFGFILE="$1"
	if [ ! -f "${CFGFILE}" ]; then
		echo "rumprun-bake: error: Configuration file ${CFGFILE} not found"
		exit 1
	fi

	_VERSOK=false

	# ". foo" doesn't work everywhere/always, so do a dance here.
	# Note: CFGFILE needs to remain as what the user gave.
	case "$1" in
	/*)
		. "${CFGFILE}"
		;;
	*)
		. "$(pwd)/${CFGFILE}"
		;;
	esac
	${_VERSOK} || _die "config version not specified (${CFGFILE})"

	unset CFGFILE

	# Publish configs which are not private
	for x in ${ALLCONFIGS}; do
		[ "${x#_}" = "${x}" ] || _filter ${x} ALLCONFIGS
	done
}

_getoneinfo ()
{

	bin="$1"
	var="$2"
	unset tmp

	notesect=.note.rumprun.bakerecipe
	tmp="$(!LIBEXEC_READELF! -p ${notesect} ${bin} 2>/dev/null \
	    | sed -n '/.*rumprun_'"${var}"': /p')"
	[ -n "${tmp}" ] \
	    || _die "Could not extract \"${var}\" from ${bin}. Not rumprun bin?"

	# now that we've verified the entry is present, reduce to
	# contents (which may be empty)
	tmp="${tmp#*rumprun_${var}: }"

	cvar=$(echo ${var} | tr '[a-z]' '[A-Z]')

	eval [ \"\${RUMPBAKE_${cvar}:=${tmp}}\" = \"${tmp}\" ] || \
	    _die ${var} mismatch in binaries
}

_getbininfo ()
{

	# extract bake recipe
	for x in tuple tooldir backingcc cflags; do
		_getoneinfo "${1}" ${x}
	done
}

# does not respect runcmd.  let's not mope and whine over it
TMPDIR=$(mktemp -d /tmp/rumprun-bake.XXXXXX)
trap _nuketmpdir 0 INT TERM

_readconfig "!DESTDIR!/etc/rumprun-bake.conf"

while getopts "c:m:n" opt; do
	case "${opt}" in
	c)
		_readconfig "${OPTARG}"
		;;
	m)
		# save.  we have to process them after configs are processed
		echo "${OPTARG}" >> ${TMPDIR}/manualcmds
		;;
	n)
		runcmd=echo
		;;
	*)
		_usage
		;;
	esac
done

shift $((${OPTIND}-1))
TARGET="${1}"

if [ "${TARGET}" = "list" ]; then
	for x in ${ALLCONFIGS}; do
		eval mydesc="\${CONFDESCR_${x}}"
		printf '%-16s' "${x}"
		printf ': %s' "${mydesc}"
		printf '\n'
	done
	exit 0
fi

if [ "${TARGET}" = "describe" ]; then
	CONFIG=$2
else
	CONFIG=$1
fi

# process potential manual commands
if [ -f ${TMPDIR}/manualcmds ]; then
	printf "version %s\n" ${_RUMPBAKE_VERSION} > ${TMPDIR}/cmdconfig
	printf "conf %s\n" ${CONFIG} >> ${TMPDIR}/cmdconfig
	cat ${TMPDIR}/manualcmds >> ${TMPDIR}/cmdconfig
	printf 'fnoc\n' >> ${TMPDIR}/cmdconfig
	_readconfig ${TMPDIR}/cmdconfig
fi

if [ "${TARGET}" = "describe" ]; then
	[ $# -eq 2 ] || _die \"describe\" needs exactly one config.
	CONF=$2
	debugdump
	exit 0
fi

OUTPUT="${2}"
[ $# -gt 2 ] || _usage
shift 2

unset RUMPBAKE_BACKINGCC
unset RUMPBAKE_TUPLE
unset RUMPBAKE_CFLAGS

# XXX: TOOLDIR is just dirname $0, so can simplify that bit
unset RUMPBAKE_TOOLDIR

[ $# -le 8 ] || { echo '>> max 8 binaries supported currently' ; exit 1; }

# Santize the config argument passed in to remove shell
# metacharacters
config="$(echo ${TARGET} | sed -e 's/-/_/g' -e 's/[^A-Za-z0-9_]//g')"
for c in ${ALLCONFIGS}; do
	[ "$c" = "$config" ] && break
done
if [ "$c" != "$config" ]; then
	echo "rumprun-bake: error: unsupported config \"$config\""
	exit 1
fi

_uniq CONFIG_${config}

PLATFORM=${config%%_*}
eval LIBS="\${CONFIG_${config}}"

# Check if the file is a relocatable object produced by a rumprun toolchain.
# Create a temporary object with a unique "main"
objnum=1
allobjs=
for f in "$@"; do
	_getbininfo ${f}

	${runcmd} ${RUMPBAKE_TOOLDIR}/bin/${RUMPBAKE_TUPLE}-objcopy	\
	    --redefine-sym main=rumprun_main${objnum}			\
	    ${f} ${TMPDIR}/tmp${objnum}.obj
	allobjs="${allobjs} ${TMPDIR}/tmp${objnum}.obj"
	objnum=$((${objnum}+1))
done

MACHINE_GNU_ARCH=${RUMPBAKE_TUPLE%%-*}


# Final link using cc to produce the unikernel image.
${runcmd} ${RUMPBAKE_BACKINGCC} ${RUMPBAKE_CFLAGS} !EXTRACCFLAGS!	\
    --sysroot ${RUMPBAKE_TOOLDIR}/rumprun-${MACHINE_GNU_ARCH}		\
    -specs=${RUMPBAKE_TOOLDIR}/rumprun-${MACHINE_GNU_ARCH}/lib/rumprun-${PLATFORM}/specs-bake \
    -o ${OUTPUT} ${allobjs}						\
    -Wl,--whole-archive ${LIBS} || exit 1

exit 0