#!/bin/ksh93

CMD=${.sh.file##*/}

function usage {
	print -u2 "Usage: ${CMD} [--linkwith-{exec|so|a}] heapfile execfile"
	exit 1
}

function die {
	print -u2 "${CMD}: $1"
	exit 1
}

[[ -z ${SMLNJ_HOME} ]] && BIN_DIR="@CLIENT_BASEDIR@/lib/smlnj/bin" || BIN_DIR=${SMLNJ_HOME}/bin
. "${BIN_DIR}/.arch-n-opsys"

RUNX="${BIN_DIR}/.run/runx.${ARCH}-${OPSYS}"
RUN_SO="${BIN_DIR}/.run/run.${ARCH}-${OPSYS}.so"
RUN_A="${BIN_DIR}/.run/run.${ARCH}-${OPSYS}.a"

# prefer heap2asm from the same directory as this script
H2A=${.sh.file}
[[ ${H2A} =~ / ]] && H2A="${H2A%/*}" || H2A=
[[ ${H2A:0:1} == '/' ]] || H2A="${PWD}/${H2A}"
H2A+='/heap2asm'
[[ ! -x ${H2A} ]] && H2A="${BIN_DIR}/heap2asm"

FORMAT=
if (( $# != 2 )); then
	(( $# != 3 )) && usage
	case $1 in
		--linkwith-exec) FORMAT='exec' ;;
		--linkwith-so) FORMAT='so' ;;
		--linkwith-a) FORMAT='a' ;;
		*) usage ;;
	esac
	shift
elif [[ ${OPSYS} == 'darwin' ]]; then
	FORMAT='exec'
elif [[ ${OPSYS} == 'freebsd' || ${OPSYS} == 'linux' ]]; then
	FORMAT='a'
fi
[[ -z ${FORMAT} ]] && die "no runtime object format specified"

heapfile="$1"
execfile="$2"

CC=gcc
LD=ld

EXEC_PROG=
EXEC_FLAGS=
EXEC_LIBS=
SO_PROG=
SO_FLAGS=
SO_LIBS=
A_PROG=
A_FLAGS=
A_LIBS=

case "${OPSYS}" in
	darwin)
		EXEC_PROG=${LD}
		EXEC_LIBS=-lc
		;;
	freebsd)
		SO_PROG=${CC}
		SO_FLAGS=-Wl,--export-dynamic
		SO_LIBS=-lm
		A_PROG=${CC}
		A_FLAGS=-Wl,--export-dynamic
		A_LIBS=-lm
		;;
	linux)
		SO_PROG=${CC}
		SO_FLAGS=-Wl,--export-dynamic
		A_PROG=${CC}
		A_FLAGS=-Wl,--export-dynamic
		A_LIBS="-lm -ldl"
		;;
esac

# die early
[[ -x ${H2A} ]] || { print -u2 "${CMD}: heap2asm is not found"; exit 2; }
if [[ ${FORMAT} == 'exec' && -f "${RUNX}" ]]; then
	[[ -z ${EXEC_PROG} ]] && die "${MSG}"
elif [[ ${FORMAT} == 'so' && -f ${RUN_SO} ]]; then
	[[ -z ${SO_PROG} ]] && die "${MSG}"
elif [[ ${FORMAT} == 'a' && -f ${RUN_A} ]]; then
	[[ -z ${A_PROG} ]] && die "${MSG}"
else
	print -u2 "${CMD}: linkable runtime system object (${FORMAT}) not available"
	exit 2
fi

integer RESULT=0

${H2A} ${heapfile} ${execfile}.s || die "heap2asm failed"
[[ -f ${execfile}.s ]] || die "${execfile}.s creation failed"
if ${CC} -c -o "${execfile}".o "${execfile}".s ; then
	rm "${execfile}".s
else
	rm "${execfile}".s
	die "${execfile}.o creation failed"
fi

MSG="no linker specified for runtime format ${FORMAT}"
if [[ ${FORMAT} == 'exec' ]] ; then
	${EXEC_PROG} ${EXEC_FLAGS} -o "${execfile}" ${RUNX} "${execfile}".o ${EXEC_LIBS}
	RESULT=$?
elif [[ ${FORMAT} == 'so' ]] ; then
	${SO_PROG} ${SO_FLAGS} -o "${execfile}" ${RUN_SO} "${execfile}".o ${SO_LIBS}
	RESULT=$?
elif [[ ${FORMAT} == 'a' ]] ; then
	${A_PROG} ${A_FLAGS} -o "${execfile}" ${RUN_A} "${execfile}".o ${A_LIBS}
	RESULT=$?
fi
rm "${execfile}".o

(( RESULT )) && die "linking failed with return code ${RESULT}"

exit 0