gpp-run

#!/bin/bash

function usage {
	echo "Usage: $(basename "$0") {--gdb, force} [sources] -- [args to program]" >&2
	exit 255
}

function array_add {
	eval "$1[\${#$1[@]}]=\"\$2\""
}

function array_echo {
	local elements="$1[@]"
	for x in ${!elements}; do
		echo "$x"
	done
}

function run_echo {
	echo "$@" >&2
	"$@"
}

function check_age {
	# @ [targets] -- [sources]
	# return 0, target needs recreation
	# return 1, target is updated
	# return 128 >= errors

	local dts="" ndts=
	while [[ $# != 0 && "$1" != "--" ]]; do
		local destfile="$1"
		shift

		if [[ ! -e "${destfile}" ]]; then
			ndts=0

		elif [[ ! -f "${destfile}" ]]; then
			echo "target '${destfile}' must be a regular file" >&2
			return 134

		else
			ndts="$(stat -L -c %Y "${destfile}")"
		fi

		[[ ! "$dts" || "$ndts" -lt "$dts" ]] && dts="$ndts"
	done

	if [[ ! "$dts" ]]; then
		echo "no targets specified" >&2
		return 133
	fi

	shift # throw "--"

	local sourcefile= nsts= sts= has_sources=
	for sourcefile in "$@"; do
		if [[ ! -e "${sourcefile}" ]]; then
			echo "missing source '${sourcefile}'" >&2
			return 128

		elif [[ ! -f "${sourcefile}" ]]; then
			echo "source '${sourcefile}' must be a regular file" >&2
			return 130

		else
			nsts="$(stat -L -c %Y "${sourcefile}")" || return 131
			has_sources=1
		fi
		# Dest timestamp lower than source timestamp ? The update the destination.
		# Don't break loop just yet, so to check that all sources are available.
		[[ "$nsts" && "$dts" -lt "$nsts" ]] && sts="$nsts"
	done

	if [[ ! "$has_sources" ]]; then
		echo "no sources specified" >&2
		return 132

	elif [[ "$sts" ]]; then
		# sts now holds a time with a more recent source, then the destinations.
		return 0

	else
		# Source are older
		return 1
	fi
}


function parse_arguments {
	while [[ $# != 0 ]]; do
	case "$1" in
	-h|--help)
		usage
		;;
	--force)
		force=1
		;;
	--gdb)
		gdb_prolog=( gdb -ex=run --args )
		;;
	--)
		break;
		;;
	-*)
		array_add compiler_args "$1"
		;;
	*)
		array_add sources "$(readlink -m "$1")"
		;;
	esac
	shift
	done

	program_args=( "$@" )

	[[ ${#sources[@]} = 0 ]] && usage
}

function main {
	# Uncomment to CD into script folder.
	# cd "$(readlink -m "$BASH_SOURCE" | xargs dirname)"
	local compiler_args=()
	local sources=()
	local program_args=()
	local gdb_prolog=()
	local force=

	parse_arguments "$@"

	local checksum="$(array_echo sources | sort | md5sum | awk '{print $1}')"

	local executable="/tmp/${checksum}"

	if [[ "$force" ]] || check_age "$executable" -- "${sources[@]}"; then
		run_echo g++ -std=c++11 "${sources[@]}" -Werror -Wall -g -O0 -o "$executable"

		local status=$?
		if [[ $status != 0 ]]; then
			rm -f "$executable"
			exit $status
		fi
	fi

	if [[ -x "$executable" ]]; then
		echo "Have executable $executable" >&2

		"${gdb_prolog[@]}" "$executable" "${program_args[@]}"

		exit $?
	fi

	exit 0
}

main "$@"