path: root/core/bin/setup_target

#!/bin/bash
# -----------------------------------------------------------------------------
#
# Copyright (c) 2011..2018 bwLehrpool-Projektteam
#
# This program/file is free software distributed under the GPL version 2.
# See https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
#
# If you have any feedback please consult https://bwlehrpool.de and
# send your feedback to bwlehrpool@hs-offenburg.de.
#
# General information about bwLehrpool can be found at https://bwlehrpool.de
#
# -----------------------------------------------------------------------------
#
#	This file contains the functions needed to setup a target.
#	The main function is 'generate_target' which will go over all
#	activated modules (symlinks found under core/targets/<target> or
#	overlay/targets/<target>) and run the module-specific 'fetch_source',
#	'build' and 'post_copy' functions of the modules.
#
#	The functions defined here are module-independent, meaning they
#	can process any module, as long as following requirements are met:
#
#		- Modules need to have a build-script and a config file,
#		  i.e. core/module/kernel/module.build
#		  and  core/module/kernel/module.conf
#		  as these will be read by 'process_module'.
#
#		- Modules do not change anything inside the module dirs anymore,
#		  everything (triggerfiles, source download, build) is done in
#		  tmp/work/<MODULE>
#
#		- Several information have to be set in the config file of
#		  a module:
#		    * REQUIRED_BINARIES - list of binaries
#		    * REQUIRED_FILES - list of regular files
#		    * REQUIRED_DIRECTORIES - list of directories
#		    * REQUIRED_SYSTEM_FILES - files to be copied directly from the system
#		    * REQUIRED_INSTALLED_PACKAGES - list of packages needed at build-time
#		    * REQUIRED_CONTENT_PACKAGES - list of packages where the contents are to be copied
#		    * (optional variables needed by the module-build-script)
#
#		  NOTE: REQUIRED_BINARIES, REQUIRED_FILES, REQUIRED_FILES will be ONLY looked
#		        for in the module's own build directory!
#
#	Optionally, a module can have a static data directory under
#	core/modules/<module>/data which will be copied as is to the target build directory.
#
#	Moreover modules do not need to specify the dynamic dependencies of given binaries
#	as these will be determined automaticly by the helper function 'get_dynamic_dependencies'
# -----------------------------------------------------------------------------
#
CORE_DIR="${ROOT_DIR}/core"
OVERLAY_DIR="${ROOT_DIR}/overlay"
EXPORT_DIR="/export/build"
[ -z "$REMOTE_EXPORT_DIR" ] || EXPORT_DIR=$REMOTE_EXPORT_DIR

initial_checks () {
	get_kernel_version
	detect_distribution
}

# WTF!?
set_target_dir () {
	if [ -d "${OVERLAY_DIR}/targets/${TARGET}" ]; then
		TARGET_DIR="${OVERLAY_DIR}/targets/${TARGET}"
	elif [ -d "${CORE_DIR}/targets/${TARGET}" ]; then
		TARGET_DIR="${CORE_DIR}/targets/${TARGET}"
	fi
}

#
# generic function to read the config file of the current $MODULE
#
read_config () {
	# unset previous variables from other config files
	for VARNAME in ${!REQUIRED_*}; do
		unset $VARNAME
	done

	local MODULE_CONFIG="${MODULE_DIR}/module.conf"

	# sanity checks
	[ ! -e "${MODULE_CONFIG}" ] && perror "Config for '$MODULE' not found."
	validate_config "$MODULE_CONFIG"
	# source the config file
	. "${MODULE_CONFIG}" || perror "Sourcing '${MODULE_CONFIG}' failed."
	# sanity checks - no distribution specific things in the global config
	local CHECK
	for CHECK in REQUIRED_CONTENT_PACKAGES REQUIRED_INSTALLED_PACKAGES; do
		[ -n "${!CHECK}" ] && perror "$CHECK is set in ${MODULE}.conf, but distribution specific config has to go to one of these files:\n$PRINT_SYS_VERSIONS"
	done
	local FILE
	for FILE in $SYS_VERSIONS; do
		if [ -e "${MODULE_CONFIG}.${FILE}" ]; then
			# a specific tool.conf seems to exist, use it to override/extend certain vars
			validate_config "${MODULE_CONFIG}.${FILE}"
			. "${MODULE_CONFIG}.${FILE}" || perror "Sourcing '${MODULE_CONFIG}.${FILE}' failed."
			pinfo "Sourced distribution specific config (${MODULE_CONFIG##*/}.${FILE})"
			return # end function
		fi
	done
	# reaching here means no specific config
	pinfo "Sourced general module config only (${MODULE_CONFIG##*/})"
}

validate_config () {
	local INVALID=$(grep -h -E -o '^\s*\w+=' "$1" | grep -v -E '^\s*REQUIRED_')
	[ -z "$INVALID" ] && return 0
	local i
	for i in $INVALID; do
		pwarning "Invalid variable $i"
	done
	perror "$1 contains invalid variables. All variables must start with REQUIRED_"
}

#
# generic function to read the build script of the current $MODULE
#
read_build () {
	local BUILD_SCRIPT="${MODULE_DIR}/module.build"

	[ ! -e "${BUILD_SCRIPT}" ] && perror "Build script for specified tool not found."

	. "${BUILD_SCRIPT}" || perror "Sourcing '${BUILD_SCRIPT}' failed."
}

export_builds() {
	[ ! -d "${ROOT_DIR}/var/builds" ] && perror "No ${ROOT_DIR}/var/builds, nothing to export."
	if mount|grep -q ${ROOT_DIR}/var/builds; then
		pwarning "${ROOT_DIR}/var/builds already exported! Ignoring..."
		return 1;
	fi
	pinfo "Mounting ${ROOT_DIR}/var/builds to ${EXPORT_DIR}."
	pinfo "This will make the local var/builds syncable from another machine."
	[ ! -d "${EXPORT_DIR}" ] && mkdir -p "${EXPORT_DIR}"
	mount --bind ${ROOT_DIR}/var/builds ${EXPORT_DIR} || perror "Failed to bind mount ${ROOT_DIR}/var/builds to ${EXPORT_DIR}"
}

#
# main function which copies all files, directories, binaries and external libraries to TARGET_BUILD_DIR
# called after building the module
#
copy_files_with_deps () {

	[ ! -d "$MODULE_BUILD_DIR" ] && pinfo "No build directory found, skipping dependency copying" && return 0
	cd "$MODULE_BUILD_DIR"

	local COPYFILES_LIST="${TARGET_BUILD_DIR}/opt/openslx/.mltk/${MODULE}.copy_files_with_deps"
	rm -f -- "${COPYFILES_LIST}"

	# from REQUIRED_BINARIES - follow symlinks and ldd the file
	[ ! -z "${REQUIRED_BINARIES}" ] && pinfo "Gathering required binaries from config file..."
	local OPTIONAL
	for FILENAME in ${REQUIRED_BINARIES}; do
		if [[ "$FILENAME" == @* ]]; then
			OPTIONAL="yes"
			FILENAME=$(echo "$FILENAME" | cut -c 2- )
		else
			OPTIONAL="no"
		fi
		local FILE_CANDIDATES=$( find . -name "${FILENAME}" -a \( -type f -o -type l \) )
		local FINAL_LIST=""
		# Check result of find
		if [ "$(echo "$FILE_CANDIDATES" | wc -l)" -gt 1 ]; then
			# More than one match for binary
			pdebug "Candidates for $FILENAME are: $(echo $FILE_CANDIDATES)"
			for FILE in $FILE_CANDIDATES; do
				local TESTFILE="$(readlink -f "$FILE")"
				pdebug "  $FILE leads to $TESTFILE"
				[ -f "$TESTFILE" -a -x "$TESTFILE" ] && FINAL_LIST="$FINAL_LIST $FILE"
			done
			FINAL_LIST=$(trim "$FINAL_LIST")
			if [ -z "$FINAL_LIST" ]; then
				perror "\tNo binary found for ${FILENAME}. None of the candidates ($FILE_CANDIDATES) is executable."
			fi
			if [[ "$FINAL_LIST" == *" "* ]]; then
				pdebug "Found more than one match for required file '$FILENAME': $FINAL_LIST"
			else
				pdebug "\tFound ${FILENAME} at ${FILE}"
			fi
		elif [ "$OPTIONAL" == "no" -a -z "$FILE_CANDIDATES" ]; then
			# No candidate
			perror "Could not find required binary $FILENAME"
		else
			# One candidate
			local TESTFILE=$(readlink -f "$FILE_CANDIDATES")
			if [ -f "$TESTFILE" -a -x "$TESTFILE" ]; then
				FINAL_LIST=${FILE_CANDIDATES}
			elif [ "$OPTIONAL" = "no" ]; then
				perror "No executable regular file found for '$FILENAME' (potential match was $(echo $FILE_CANDIDATES))"
			fi
		fi
		for FILE in $FINAL_LIST; do
			pdebug "* $FILE"
			get_link_chain "${MODULE_BUILD_DIR}/${FILE}" "${MODULE_BUILD_DIR}" >> "${COPYFILES_LIST}"
			get_dynamic_dependencies -l "${MODULE_BUILD_DIR}" "${FILE}" >> "${COPYFILES_LIST}"
		done
	done

	# from REQUIRED_LIBRARIES - like binaries, follow symlinks and ldd, but also expand the lib-name
	# by looking for files named <libname>.so*
	[ ! -z "$REQUIRED_LIBRARIES" ] && pinfo "Gathering required libraries from config file..."
	for LIB in $REQUIRED_LIBRARIES; do
		FILE_CANDIDATES=$(find . -name "${LIB}.so*")
		[ -z "$FILE_CANDIDATES" ] && perror "Cannot find required library $LIB"
		for LOCATION in $FILE_CANDIDATES; do
			pdebug "* $LOCATION"
			get_link_chain "${MODULE_BUILD_DIR}/${LOCATION}" "${MODULE_BUILD_DIR}"  >> "${COPYFILES_LIST}"
			get_dynamic_dependencies -l "${MODULE_BUILD_DIR}" "${LOCATION}" >> "${COPYFILES_LIST}"
		done
	done

	# from REQUIRED_DIRECTORIES - recursively copy given dirs, look for files that seem to be an elf
	# binary and do the symlink+ldd trick on them
	[ ! -z "${REQUIRED_DIRECTORIES}" ] && pinfo "Gathering required directories from config file..."
	local ENTRY=""
	for ENTRY in ${REQUIRED_DIRECTORIES}; do
		[[ "$ENTRY" == /* ]] || perror "All entries in REQUIRED_DIRECTORIES have to start with a slash '/', but $ENTRY does not!"
		[ -e "$ENTRY" -a ! -d "$ENTRY" ] && perror "$ENTRY is not a directory"
		pdebug "* $ENTRY"
		ENTRY=".${ENTRY}"
		echo "${ENTRY}" >> "${COPYFILES_LIST}"
		for BIN in $(find "${ENTRY}" -type f -a \( -executable -o -name '*.so*' \) -a -not -name '*.a'); do
			[ -f "$BIN" ] || continue
			#pdebug "\tSearching libs for ${BIN}..."
			get_link_chain "${MODULE_BUILD_DIR}/${BIN}" "${MODULE_BUILD_DIR}" >> "${COPYFILES_LIST}"
			get_dynamic_dependencies -l "${MODULE_BUILD_DIR}" "${BIN}" >> "${COPYFILES_LIST}"
		done
	done

	# from REQUIRED_FILES - these are assumed to be simple files, so only follow symlinks
	[ ! -z "${REQUIRED_FILES}" ] && pinfo "Gathering required files from config file..."
	for ENTRY in ${REQUIRED_FILES}; do
		get_link_chain "${MODULE_BUILD_DIR}/${ENTRY}" "${MODULE_BUILD_DIR}" >> "${COPYFILES_LIST}"
	done

	#copy to initramfsdir
	pdebug "File list generated at ${COPYFILES_LIST}."
	# empty?
	if [ ! -s "$COPYFILES_LIST" ]; then
		return
	fi
	# unchanged?
	local OLD="${COPYFILES_LIST}.old"
	if [ -s "$OLD" ] && diff "$OLD" "$COPYFILES_LIST"; then
		return
	fi
	local CLISTCOUNT=$(cat "$COPYFILES_LIST" | wc -l)
	pinfo "Copying $CLISTCOUNT files to '${TARGET_BUILD_DIR}'."
	tarcopy "$(sort -u "$COPYFILES_LIST")" "${TARGET_BUILD_DIR}"
	mv -f "$COPYFILES_LIST" "$OLD"
}

#
#
# If the system has no usr split, recreate the structure in the given
# directory, otherwise, do nothing
#
#
prepare_usr_split () {
	local DIR DEST
	local BASE=$1
	[ -z "$BASE" ] && perror "prepare_usr_split called with empty base dir"
	if [ "$USR_SPLIT" == "no" ]; then # no usr split, /bin /lib etc are symlinks
		for DIR in lib lib32 lib64 bin sbin; do
			[ -L "/${DIR}" ] || continue
			DEST=$(readlink "/${DIR}")
			if [ ! -L "/${DEST}" ]; then
				mkdir -p "${BASE}/${DEST}" || perror "Could not create '${BASE}/${DEST}'"
			fi
			[ -L "${BASE}/${DIR}" ] || ln -s "${DEST}" "${BASE}/${DIR}" || perror "Could not symlink '${BASE}/${DIR}' to '${DEST}'"
		done
	fi
}

#
#
# main public function. Requires the TARGET to be given as argument.
# this will simply go over all the modules as found in the core/target/<TARGET>
# and run following functions:
#
#
generate_target() {

	initial_checks

	TARGET="$1"
	shift
	set_target_dir
	if [[ "$TARGET" == *@* ]]; then
		VARNAME="${TARGET#*@}"
		TARGET="${TARGET%@*}"
		for VERSION in ${!VARNAME}; do
			TARGET_BUILD_DIR="${ROOT_DIR}/var/builds/${TARGET}@${VERSION}"
			generate_target_real "$@"
		done
	else
		TARGET_BUILD_DIR="${ROOT_DIR}/var/builds/${TARGET}"
		generate_target_real "$@"
	fi
}

generate_target_real() {
	# Keep track of processed modules so we don't
	# build a module multiple times when following dependencies
	local PROCESSED_MODULES=
	[ -e "${ROOT_DIR}/var/log/${TARGET}.size" ] && . "${ROOT_DIR}/var/log/${TARGET}.size" || echo "declare -A BUILD_SIZE" >> "${ROOT_DIR}/var/log/${TARGET}.size"

	[ -d "$TARGET_DIR" ] || perror "Given target directory does not exist: $TARGET_DIR"

	[[ "$TARGET" == "builds" || "$TARGET" == "modules" ]] && \
		perror "Target directory cannot be named 'builds' or 'modules'."

	pdebug "Generating '$TARGET_BUILD_DIR' for '$TARGET'"
	mkdir -p "$TARGET_BUILD_DIR" || perror "Failed to create $TARGET_BUILD_DIR"
	prepare_usr_split "${TARGET_BUILD_DIR}"

	# if no arguments assume all.
	if [ "x$1" = "x" -o "x$1" = "xall" ]; then
		MODULES=$( ls "${TARGET_DIR}" )
		set -- $MODULES
	else
		# tools = arguments given
		MODULES=$@
	fi

	pinfo "Activated modules in '${TARGET}':"
	pinfo "\t$(echo ${MODULES})"

	# copy basic libs
	pinfo "Copying libc and ld-linux used by ${SHELL}"
	tarcopy "$(list_basic_libs)" "${TARGET_BUILD_DIR}"

	# now iterate over given tools and copy them
	while (( "$#" )); do
		process_module "$1"
		shift
	done

	post_process_target

	pinfo "Target completed. Total size: $(du -bsh "${TARGET_BUILD_DIR}" | awk 'END {print $1}')"
	TOOL_STR=""
}

process_module() {
	# Parse arguments
	[ "$#" -lt "1" ] && perror "process_module: want >= 1 param."
	if [ "x$1" = "x--dep-of" ]; then
		shift
		local DEPOF=" $1"
		shift
	else
		local DEPOF=""
	fi
	local MODULE="$1"
	[ -z "$MODULE" ] && perror "No module given when calling process_module"
	[[ "$PROCESSED_MODULES" == *"!${MODULE}!"* ]] && return # Already processed this module
	# Set up dirs ans variables
	PROCESSED_MODULES="${PROCESSED_MODULES}!${MODULE}!"
	local MODULE_DIR="${TARGET_DIR}/${MODULE}"
	local MODULE_WORK_DIR="${ROOT_DIR}/tmp/work/${MODULE}"
	local MODULE_BUILD_DIR="${MODULE_WORK_DIR}/build"
	local TOOL_STR="[${MODULE}]"
	local SOURCE_FLAG="$MODULE_BUILD_DIR/fetched_source.flag"
	local BUILD_FLAG="$MODULE_BUILD_DIR/build_complete.flag"
	local MD5FILE="${TARGET_BUILD_DIR}/opt/openslx/.mltk/${MODULE}.md5"
	mkdir -p "${TARGET_BUILD_DIR}/opt/openslx/.mltk"
	if [ ! -d "${MODULE_DIR}" ]; then
		if [ -z "$DEPOF" ]; then
			perror "Module directory for '$MODULE' not found in ${TARGET_DIR}"
		fi
		perror "Module directory for '$MODULE' not found in ${TARGET_DIR} (is a dependency of${DEPOF})"
		return
	fi
	mkdir -p "${MODULE_WORK_DIR}"
	cd "${MODULE_DIR}" || perror "Module work dir '${MODULE_DIR}' seems to exist, but cd to it failed."
	# Simple check for modified .build / .config, in which case we'll run a module clean first
	if [ -f "$MD5FILE" ]; then
		if ! md5sum --check "$MD5FILE"; then
			# Mismatch
			if [ "x$MODULE" = "xkernel" ]; then
				pwarning " ** Kernel .build/.config changed, but won't autoclean."
				pwarning " ** Check if cleaning should be done and use '-c kernel'"
			else
				pwarning "Module's .build/.config has changed, rebuilding!"
				clean_module "${TARGET}:${MODULE}"
			fi
		elif [ ! -e "$SOURCE_FLAG" ] || [ ! -e "$BUILD_FLAG" ]; then
			# One of the flags is missing, in this case delete the .md5 file
			# which would prevent dependency copying etc. below
			rm -f -- "$MD5FILE"
		fi
	fi
	# Process module
	pdebug "## Reading config of $MODULE"
	read_config
	# Prepare build directory
	mkdir -p "${MODULE_BUILD_DIR}" || perror "Could not create build dir"
	prepare_usr_split "${MODULE_BUILD_DIR}"
	# Check if this module has a dependency that wasn't built yet:
	if [ ! -z "$REQUIRED_MODULES" ]; then
		pdebug "$MODULE depends on ${REQUIRED_MODULES}...."
		for DEP in $REQUIRED_MODULES; do
			process_module --dep-of "${MODULE}${DEPOF}" "$DEP"
		done
		# Read old config again, as it got overwritten by the deps
		cd "${MODULE_WORK_DIR}" || perror "Tool dir '${MODULE_WORK_DIR}' seems to exist, but cd to it failed (after building deps)."
		read_config
	fi
	[ -n "$DEPOF" ] && local DEPOF_STR="(dependency of${DEPOF})"
	pinfo ">>>>>>>>>>>>>>>>> Processing module [ $MODULE ] $DEPOF_STR"
	# Update size of target build dir
	if [ -d "${TARGET_BUILD_DIR}" ]; then
		TARGET_BUILD_SIZE=$(du -bc "${TARGET_BUILD_DIR}" | awk 'END {print $1}')
	else
		TARGET_BUILD_SIZE=0
	fi
	# Source .build script of module
	pdebug "## Reading .build of $MODULE"
	. "${CORE_DIR}/includes/clean_module_funcs.inc" # Clean all hooks, in case the module doesn't define them all
	read_build # Read all the hooks from the module
	# Install module's dependencies
	pdebug "## Installing dependencies"
	cd "${MODULE_DIR}" || perror "cd to '${MODULE_DIR}' failed."
	install_dependencies
	# update kernel version variables before running a module, as the last one might have been the kernel...
	get_kernel_version
	# Execute load-hook before anything else
	module_load
	cd "${MODULE_WORK_DIR}" || perror "cd to '${MODULE_WORK_DIR}' failed."
	# Fetch source code
	if [ ! -e "$SOURCE_FLAG" ]; then
		pinfo "## Fetching source"
		fetch_source
		touch "$SOURCE_FLAG" || pwarning "Error setting source-flag"
	fi
	# Build
	if [ ! -e "$BUILD_FLAG" ]; then
		pinfo "## Building"
		cd "${MODULE_WORK_DIR}" || perror "cd to '${MODULE_WORK_DIR}' failed."
		build # calls perror if something fails, no need to do that here
		strip_recursive "$MODULE_BUILD_DIR"
		touch "$BUILD_FLAG" || pwarning "Error setting built-flag"
	fi
	# Remove *.la files as they might confuse libtool/linker of other tool packages
	[ -d "${MODULE_BUILD_DIR}" ] && find "${MODULE_BUILD_DIR}" -name '*.la' -exec rm -f {} \;
	# Only copy stuff from system or build dir if md5s didn't change
	if [ ! -f "$MD5FILE" ]; then
		pinfo "## Copying files with dependencies"
		cd "${MODULE_DIR}" || perror "cd to '${MODULE_DIR}' failed."
		copy_files_with_deps
		if [ -n "$REQUIRED_SYSTEM_FILES" ]; then
			pinfo "## Copying required system files" # REQUIRED_SYSTEM_FILES
			cd "${MODULE_DIR}" || perror "cd to '${MODULE_DIR}' failed."
			copy_system_files
		fi
	fi
	# Always copy static data
	if [ -d "${MODULE_DIR}/data" ]; then
		pinfo "## Copying static module files"
		copy_static_data
	fi
	# TODO: automatic copy of REQUIRED_CONTENT_PACKAGES
	pinfo "## Post copy"
	cd "${MODULE_DIR}" || perror "cd to '${MODULE_DIR}' failed."
	post_copy
	# Write new md5 file if not existent yet
	if [ ! -f "$MD5FILE" ]; then
		md5sum "$MODULE_DIR/module".* > "$MD5FILE" || perror "Could not create $MD5FILE"
	fi
	# Sanity checks
	[ -e "$TARGET_BUILD_DIR/var/run" -a ! -L "$TARGET_BUILD_DIR/var/run" ] && perror "Messup datected: $TARGET_BUILD_DIR/var/run exists and is not a symlink!"
	[ -e "$TARGET_BUILD_DIR/var/lock" -a ! -L "$TARGET_BUILD_DIR/var/lock" ] && perror "Messup datected: $TARGET_BUILD_DIR/var/lock exists and is not a symlink!"
	[ -n "$(ls -A "$TARGET_BUILD_DIR/run" 2>> /dev/null)" ] && perror "Messup detected: $TARGET_BUILD_DIR/run is not empty. You cannot place static files there, use /etc/tmpfiles.d instead!"
	# set MODULE_BUILD_SIZE
	calc_size
	pinfo "Module completed. Total size: ${MODULE_BUILD_SIZE}"
}

post_process_target() {
	local TOOL_STR="$TOOL_STR post_process_target:"

	# figure out all relevant ld-paths
	pinfo "Running ldconfig"
	cp -r -L /etc/ld.so.conf* "${TARGET_BUILD_DIR}/etc/"
	ldconfig -v -r "${TARGET_BUILD_DIR}"
}

clean_modules() {

	TARGET=$1
	shift
	# TODO: what was the idea of target path? presumably something to do with the 'overlays' folder?
	#TARGET_DIR="$(target_path ${TARGET})"
	TARGET_DIR="${CORE_DIR}/targets/${TARGET}"
	TARGET_BUILD_DIR="${ROOT_DIR}/var/builds/${TARGET}"
	[ -d $TARGET_DIR ] || perror "Given target directory does not exist: $TARGET_DIR"

	if [ "x$1" = "x" -o "x$1" = "xall" ]; then
		if [ -e "${ROOT_DIR}/var/log/${TARGET}.size" ]; then
			rm "${ROOT_DIR}/var/log/${TARGET}.size" || perror "Could not delete var/log/${TARGET}.size"
		fi
		if [[ "$TARGET" == *@* ]]; then
			rm -rf -- "${TARGET_BUILD_DIR%@*}"@* || perror "Could not delete target build dirs for $TARGET"
		else
			rm -rf -- "${TARGET_BUILD_DIR}" || perror "Could not delete target build dir for $TARGET"
		fi
		# exclude kernel on "all"
		set -- $(ls "${TARGET_DIR}" | grep -vE "^kernel$")
	fi
	cd "$TARGET_DIR"

	while (( "$#" )); do
		clean_module "${TARGET}:$1"
		shift
	done
	cd - &> /dev/null
}

clean_module() {
	[ -z "$1" ] && perror "No module given on clean_module()"
    pinfo "## clean_module $1"

	local TARGET=${1%:*}
	local MODULE=${1#*:}
	local MODULE_DIR="${CORE_DIR}/targets/${TARGET}/${MODULE}"
	local MODULE_WORK_DIR="${ROOT_DIR}/tmp/work/${MODULE}"

	if ! [ -d "$MODULE_DIR" ]; then
		pwarning "No such module '$MODULE' in current target '$TARGET'"
		pwarning "Check your spelling"
		if [ -d "$MODULE_WORK_DIR" ]; then
			pwarning "Continuing anyways since the according work dir exists..."
		else
			return 1
		fi
	fi

	pinfo "Cleaning '$1'..."
	rm -rf -- "${MODULE_WORK_DIR}" || perror "Could not delete work dir"
	rm -f -- "${TARGET_BUILD_DIR}/opt/openslx/.mltk/${MODULE}."* # no space here!
	return 1
}

# Recursively strip binaries and libraries in the given directory
strip_recursive() {
	local DIR="$1"
	[ -n "$DIR" -a -d "$DIR" ] || perror "strip_recursive(): No such directory: '$DIR'"
	# Will try to strip shell scripts too but shouldn't do any harm
	# Ignore anything we compile ourselves so we have usable core dumps
	find "$DIR" -type f \! -path "*openslx*bin*" -a \( -executable -o -name "*.so*" \) -exec strip {} \; 2> /dev/null
}

# copies static data files from <MODULE>/data/ to <TARGET_BUILD_DIR>
copy_static_data() {
	[ ! -d "${MODULE_DIR}/data" ] && pinfo "${MODULE} has no static 'data' directory." && return
	cd "${MODULE_DIR}/data/" || perror "could not cd to '${MODULE_DIR}/data/'"
	pinfo "tarcopy ${MODULE_DIR}/data/"
	tarcopy "$(find . -type f -o -type l)" "${TARGET_BUILD_DIR}"
	cd -
}

# Copies files with their absolute paths in $REQUIRED_SYSTEM_FILES to $TARGET_BUILD_DIR
copy_system_files() {
	[ -z "$REQUIRED_SYSTEM_FILES" ] && return
	local file list
	list=
	for file in $REQUIRED_SYSTEM_FILES; do
		list+=" $(get_link_chain "$file")"
	done
	tarcopy "$list" "$TARGET_BUILD_DIR"
}

# Tries to calculate the size of modules - doesn't seem to work all the time
calc_size() {

	local CURRENT_BUILD_SIZE=$(du -bc "${TARGET_BUILD_DIR}" | awk 'END {print $1}')

	[ ! -z "${BUILD_SIZE[$MODULE]}" ] && local OLD_MODULE_SIZE=${BUILD_SIZE[$MODULE]} || local OLD_MODULE_SIZE=0
	local diff=$((CURRENT_BUILD_SIZE-TARGET_BUILD_SIZE+OLD_MODULE_SIZE))

	if [ -z "${BUILD_SIZE[$MODULE]}" ]; then 
		echo "BUILD_SIZE[$MODULE]=${diff}" >> "${ROOT_DIR}/var/log/${TARGET}.size"
	else
		sed -i "s/^BUILD_SIZE\[${MODULE}\]=.*$/BUILD_SIZE\[${MODULE}\]=${diff}/g" "${ROOT_DIR}/var/log/${TARGET}.size"
	fi
	
	MODULE_BUILD_SIZE=$(echo $diff | awk '{ sum=$1; hum[1024^3]="GB"; hum[1024^2]="MB"; hum[1024]="KB"; 
					for (x=1024^3; x>=1024; x/=1024){ 
						if (sum>=x) { printf "%.2f %s\n",sum/x,hum[x]; break }
					}
				}')
}