#!/bin/sh
#
# This script is used to derive compiler flags and filesystem paths
# necessary to utilize Lua, LuaJIT, and particular versions thereof in both
# simple and mixed installation environments.
#
# For usage help information use the -h switch.
#
# This script attempts to adhere strictly to POSIX shell specifications. The
# known non-POSIX features used are the path of the shell at the very first
# line of this script, the default compiler command name of `cc' instead of
# `c99', and the use of /dev/urandom for generating a random sandbox
# directory suffix. All of these can be override. For any other issues
# please contact the author.
#
# WARNING: When searching for a Lua interpreter this script may execute
# various utilities in an attempt to deduce their fitness and release
# version. By default this script will search for and execute utilities
# using the glob patterns luac* and lua*. But this script CANNOT GUARANTEE
# that executing such utilities, or any other utilities, either wittingly or
# unwittingly, will not result in your COMPUTER EXPLODING. You have been
# warned.
#
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
# 
# Changelog:
#
# * 2013-08-02 - Published. Derived from an earlier script, lua.path,
#   written for the cqueues project.
#
# * 2013-08-05 - Redirect stdin from /dev/null when probing so we don't
#   	freeze if a utility tries to read from stdin.
#
# 	chdir to a read-only directory by default to try to prevent creation
# 	of temporary files. These features address the issues of LuaTeX
# 	reading from stdin and creating a luatex.out file in the current
# 	working directory. By default a directory with a random suffix
# 	generated from /dev/urandom is placed in TMPDIR and removed on exit.
#
# 	If CPPFLAGS is empty and no -I options directly specified then set
# 	INCDIRS to "/usr/include:/usr/local/include".
#
# * 2013-08-07 - Add pkg-config support and refactor header probing to delay
# 	recursive searching.
#
# * 2013-09-09 - NetBSD's sh gets upset over the noclobber option and
# 	redirection to /dev/null, so use append operator. And check $#
# 	before iterating over a null parameter set with `do X; ...  done`
# 	when `set -u` is enabled--it complains about $@ being unset.
#
# * 2013-10-22 - Initial ldflags detection.
#
# # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
#
# Copyright (C) 2012-2013 William Ahern
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.
#
set -e # strict errors
set -u # don't expand unbound variables
set -f # disable pathname expansion
set -C # noclobber
\unalias -a # no command surprises
export LC_ALL=C # no locale headaches
unset IFS # no field splitting surprises
: ${TMPDIR:=/tmp} # sane TMPDIR
: ${CC:=cc}

MYVERSION=20131025
MYVENDOR="william@25thandClement.com"


DEVRANDOM=/dev/urandom
SANDBOX="${TMPDIR}/${0##*/}-"

CPPDIRS=    # -I directories from CPPFLAGS
INCDIRS=
LDDIRS=     # -L directories from LDFLAGS
LIBDIRS=
BINDIRS=
RECURSE=no
MAXDEPTH=   # full command switch, like "-maxdepth 3", if supported
XDEV=       # do not cross device boundaries; i.e. "-xdev"
SHORTEST=   # continue searching until shortest pathname found
PKGCONFIG=  # path to pkg-config, found by `command -v` when -k option invoked

API_MIN=500
API_MAX=999
API_VER=
API_DIR=

JIT_REQ=
JIT_MIN=20000
JIT_MAX=99999
JIT_VER=
JIT_DIR=

LIBLUA_VER=
LIBLUA_DIR=
LIBLUA_LIB=

LIBJIT_VER=
LIBJIT_DIR=
LIBJIT_LIB=

LUAC_PATH=
LUAC_VER=

LUA_PATH=
LUA_VER=


#
# parse CPPFLAGS -I or LDFLAGS -L directories
#
xdirs() {
	OPTC="${1:-I}"
	DIRS=

	set -- ${2:-}

	while [ $# -gt 0 ]; do 
		case "${1}" in
		-${OPTC})
			shift

			if [ -n "${1:-}" ]; then
				DIRS="${DIRS}${DIRS:+:}${1}"
			fi

			;;
		-${OPTC}*)
			if [ "${1}" != "-${OPTC}" ]; then
				DIRS="${DIRS}${DIRS:+:}${1#-${OPTC}}"
			fi

			;;
		esac

		shift
	done

	printf -- "${DIRS}"
}

idirs() {
	xdirs "I" "${1:-}"
}

ldirs() {
	xdirs "L" "${1:-}"
}

# count ":" delimited directories generated by xdirs
ndirs() {
	IFS=:
	set -- ${1:-}
	unset IFS

	printf "$#\n"
}


#
# evalmacro PATH MACRO [REGEX] [SUBST]
#
# 	PATH   Header identifier--#include <PATH>
# 	MACRO  Macro identifier
# 	REGEX  Optional regex pattern to match macro evalutation result
# 	SUBST  Optional replacement expression
#
evalmacro() {
	printf "#include <$1>\n[===[$2]===]\n" \
	| ${CC:-cc} ${CPPFLAGS:-} -E - 2>>/dev/null \
	| sed -ne "
		s/^.*\\[===\\[ *\\(${3:-.*}\\) *\\]===\\].*$/${4:-\\1}/
		t Found
		d
		:Found
		p
		q
	"
}


#
# testsym PATH NAME
#
# Test whether global symbol NAME exists in object file at PATH. Exits with
# 0 (true) when found, non-0 (false) otherwise.
#
testsym() {
	# NOTE: No -P for OpenBSD nm(1), but the default output format is
	# close enough. Section types always have a leading and trailing
	# space. U section type means undefined. On AIX [VWZ] are weak
	# global symbols. Solaris and OS X have additional symbol types
	# beyond the canonical POSIX/BSD types, all of which are uppercase
	# and within [A-T].
	(nm -Pg ${1} 2>>/dev/null || nm -g 2>>/dev/null) \
	| sed -ne '/ [A-T] /p' \
	| grep -qE "${2}"
}


tryluainclude() {
	V="$(evalmacro ${1} LUA_VERSION_NUM '[0123456789][0123456789]*')"
	: ${V:=0}

	if [ "${1%/*}" != "${1}" ]; then
		D="${1%/*}"

		# cleanup after Solaris directory prune trick
		if [ "${D##*/./}" != "${D}" ]; then
			D="${D%%/./*}/${D##*/./}"
		else
			D="${D%/.}"
		fi
	else
		D=
	fi

	[ "$V" -gt 0 -a "$V" -ge "${API_VER:-0}" ] || return 0

	[ "$V" -gt "${API_VER:-0}" -o "${#D}" -lt "${#API_DIR}" -o \( "${JIT_REQ}" = "yes" -a "${JIT_VER:-0}" -lt "${JIT_MAX}" \) ] || return 0

	[ "$V" -ge "${API_MIN}" -a "$V" -le "${API_MAX}" ] || return 0

	if [ -n "${JIT_REQ}" ]; then
		J="$(evalmacro ${1%%lua.h}luajit.h LUAJIT_VERSION_NUM '[0123456789][0123456789]*')"
		: ${J:=0}

		if [ "${JIT_REQ}" = "skip" ]; then
			[ "${J}" -eq 0 ] || return 0
		elif [ "${JIT_REQ}" = "yes" ]; then
			[ "$J" -ge "${JIT_VER:-0}" ] || return 0
			[ "$J" -gt "${JIT_VER:-0}" -o "${#D}" -lt "${#JIT_DIR}" ] || return 0
			[ "$J" -ge ${JIT_MIN} ] || return 0
			[ "$J" -le "${JIT_MAX}" ] || return 0

			JIT_VER="$J"
			JIT_DIR="$D"
		fi
	fi

	API_VER="$V"
	API_DIR="$D"
}


#
# foundversion
#
# true if found the best (maximum) possible version, false otherwise
#
foundversion() {
	if [ "${API_VER:-0}" -lt "${API_MAX}" ]; then
		return 1
	fi

	if [ "${JIT_REQ}" = "yes" -a "${JIT_VER:-0}" -lt "${JIT_MAX}" ]; then
		return 1
	fi

	if [ "${SHORTEST}" = "yes" ]; then
		return 1
	fi

	return 0
}


#
# findversion
#
findversion() {
	tryluainclude "lua.h"

	if foundversion; then
		return 0
	fi


	# iterate through CPPFLAGS to probe different precedence
	if [ "${API_VER:-0}" -lt "${API_MAX}" ]; then
		IFS=:
		set -- ${CPPDIRS}
		unset IFS

		if [ $# -gt 0 ]; then
			for D; do
				tryluainclude "${D}/lua.h"

				if foundversion; then
					return 0
				fi
			done
		fi
	fi


	if [ -n "${PKGCONFIG}" ]; then
		PKGFLAGS="$(${PKGCONFIG} --list-all </dev/null 2>>/dev/null | sed -ne 's/^\(lua[^ 	]*\).*/\1/p' | xargs -- ${PKGCONFIG} --cflags 2>>/dev/null | cat)"
		PKGDIRS="$(idirs "${PKGFLAGS}")"

		IFS=:
		set -- ${PKGDIRS}
		unset IFS

		if [ $# -gt 0 ]; then
			for D; do
				tryluainclude "${D}/lua.h"

				if foundversion; then
					return 0
				fi
			done
		fi
	fi


	IFS=:
	set -- ${INCDIRS}
	unset IFS

	if [ $# -gt 0 ]; then
		for D; do
			tryluainclude "${D}/lua.h"

			if foundversion; then
				return 0
			fi
		done
	fi


	[ "${RECURSE}" = "yes" ] || return 0


	# recurse into CPPDIRS
	IFS=:
	set -- ${CPPDIRS}
	unset IFS

	if [ $# -gt 0 ]; then
		for D; do
			for F in $(find ${D} ${MAXDEPTH} ${XDEV} -name lua.h -print 2>>/dev/null); do
				tryluainclude "${F}"

				if foundversion; then
					return 0
				fi
			done
		done
	fi


	# recurse into INCDIRS
	IFS=:
	set -- ${INCDIRS}
	unset IFS

	if [ $# -gt 0 ]; then
		for D; do
			for F in $(find ${D}/. ${MAXDEPTH} ${XDEV} -name lua.h -print 2>>/dev/null); do
				tryluainclude "${F}"

				if foundversion; then
					return 0
				fi
			done
		done
	fi
}


#
# Unlike API version checking, this is less likely to be accurately forward
# compatible.
#
trylib() {
	if ! testsym "${1}" "lua_newstate"; then
		return 0
	fi

	V=0
	J=0
	D=
	F="${1##*/}"
	L=

	if [ "${1%/*}" != "${1}" ]; then
		D="${1%/*}"

		# cleanup after Solaris directory prune trick
		if [ "${D##*/./}" != "${D}" ]; then
			D="${D%%/./*}/${D##*/./}"
		else
			D="${D%/.}"
		fi
	fi

	L="${F#lib}"
	L="${L%.so}"
	L="${L%.a}"
	L="${L%.dylib}"


	# FIXME: need more versioning tests
	if testsym "${1}" "lua_getfenv"; then
		V=501
	elif testsym "${1}" "lua_yieldk"; then
		V=502
	else
		return 0
	fi

	[ "$V" -gt 0 -a "$V" -ge "${LIBLUA_VER:-0}" ] || return 0

	[ "$V" -gt "${LIBLUA_VER:-0}" -o "${#D}" -lt "${#LIBLUA_DIR}" -o \( "${JIT_REQ}" = "yes" -a "${LIBJIT_VER:-0}" -lt "${JIT_MAX}" \) ] || return 0

	[ "$V" -ge "${API_MIN}" -a "$V" -le "${API_MAX}" ] || return 0


	if [ -n "${JIT_REQ}" ]; then
		# FIXME: need more versioning tests
		if testsym "${1}" "luaopen_jit"; then
			J=20000
		fi

		if [ "${JIT_REQ}" = "skip" ]; then
			[ "${J}" -eq 0 ] || return 0
		elif [ "${JIT_REQ}" = "yes" ]; then
			[ "$J" -ge "${LIBJIT_VER:-0}" ] || return 0
			[ "$J" -gt "${LIBJIT_VER:-0}" -o "${#D}" -lt "${#LIBJIT_DIR}" ] || return 0
			[ "$J" -ge ${JIT_MIN} ] || return 0
			[ "$J" -le "${JIT_MAX}" ] || return 0

			LIBJIT_VER="$J"
			LIBJIT_DIR="$D"
			LIBJIT_LIB="$L"
		fi
	fi

	LIBLUA_VER="$V"
	LIBLUA_DIR="$D"
	LIBLUA_LIB="$L"
}


#
# foundlib
#
# true if found the best (maximum) possible version, false otherwise
#
foundlib() {
	if [ "${LIBLUA_VER:-0}" -lt "${API_MAX}" ]; then
		return 1
	fi

	if [ "${JIT_REQ}" = "yes" -a "${LIBJIT_VER:-0}" -lt "${JIT_MAX}" ]; then
		return 1
	fi

	if [ "${SHORTEST}" = "yes" ]; then
		return 1
	fi

	return 0
}


findlib() {
	if [ -n "${PKGCONFIG}" ]; then
		PKGFLAGS="$(${PKGCONFIG} --list-all </dev/null 2>>/dev/null | sed -ne 's/^\(lua[^ 	]*\).*/\1/p' | xargs -- ${PKGCONFIG} --libs 2>>/dev/null | cat)"
		PKGDIRS="$(ldirs "${PKGFLAGS}")"
		PKGDIRS="${PKGDIRS}${PKGDIRS:+:}/lib:/usr/lib:/usr/local/lib"
		NUMDIRS="$(ndirs "${PKGDIRS}")"
		PKGLIBS="$(xdirs "l" "${PKGFLAGS}")"
		NUMLIBS="$(ndirs "${PKGLIBS}")"
		ALLDIRS="${PKGDIRS}${PKGLIBS:+:}${PKGLIBS}"

		IFS=:
		set -- ${ALLDIRS}
		unset IFS

		I=1
		while [ $I -le ${NUMDIRS} ]; do
			K=$((1 + ${NUMDIRS}))
			while [ $K -le $# ]; do
				findlib_L=$(eval "printf \${$I}")
				findlib_l=$(eval "printf \${$K}")

				#printf -- "I=$I K=$K $findlib_L/lib$findlib_l*.*\n"

				for findlib_R in no ${RECURSE}; do
					for findlib_lib in $(findpath "lib${findlib_l}*.*" ${findlib_R} "${findlib_L}"); do
						trylib "${findlib_lib}"
					done

					if foundlib; then
						return 0
					fi
				done

				K=$(($K + 1))
			done
			I=$(($I + 1))
		done
	fi

	ALLDIRS="${LDDIRS}${LDDIRS:+:}${LIBDIRS}"

	IFS=:
	set -- ${ALLDIRS}
	unset IFS

	for findlib_D; do
		for findlib_R in no ${RECURSE}; do
			for findlib_lib in $(findpath "liblua*.*" ${findlib_R} "${findlib_D}"); do
				trylib "${findlib_lib}"
			done

			if foundlib; then
				return 0
			fi
		done
	done
}


findpath() {
	NAME="$1"
	WHERE="$3"

	PRUNE=

	if [ "${2}" = "no" ]; then
		PRUNE="-name . -o -type d -prune -o"
	fi

	[ ${#WHERE} -gt 0 ] || return 0

	IFS=:
	set -- ${WHERE}
	unset IFS

	if [ $# -gt 0 ]; then
		for findpath_D; do
			find "${findpath_D}/." ${MAXDEPTH} ${XDEV} ${PRUNE} -name "${NAME}" -print 2>>/dev/null | sed -e 's/\/\.//'
		done
	fi
}


# check setuid and setgid mode
safeperm() {
	[ -f "$1" -a ! -u "$1" -a ! -g "$1" ]
}


findluac() {
	while [ $# -gt 0 ]; do
		for F in $(findpath "${1}" no "${PATH}"; findpath "${1}" "${RECURSE}" "${BINDIRS}"); do
			[ -x "$F" ] && safeperm "$F" || continue

			V="$($F -v </dev/null 2>&1 | head -n1 | sed -ne 's/^Lua \([0123456789][0123456789]*\.[0123456789][0123456789]*\).*/\1/p')"
			: ${V:=0}
			V="$((${V%%.*} * 100 + ${V##*.} % 100))"

			[ "${V}" -gt 0 -a "${V}" -ge "${LUAC_VER:-0}" ] || continue

			[ "${V}" -gt "${LUAC_VER:-0}" -o "${#F}" -lt "${#LUAC_PATH}" ] || continue

			[ "${V}" -ge "${API_MIN}" -a "${V}" -le "${API_MAX}" ] || continue

			printf "return true" 2>>/dev/null | ${F} -p - </dev/null >>/dev/null 2>&1 || continue

			LUAC_PATH="$F"
			LUAC_VER="$V"

			[ "${SHORTEST}" = "yes" -o "${LUAC_VER}" -lt "${API_MAX}" ] || break 2
		done

		shift
	done
}


checkints() {
	while [ $# -gt 0 ]; do
		I="${1}"
		while [ "${#I}" -gt 0 ]; do
			if [ "${I##[0123456789]}" = "${I}" ]; then
				printf -- "${0##*/}: ${1}: not a number\n" >&2
				exit 1
			fi

			I=${I##[0123456789]}
		done

		shift
	done
}


lua2num() {
	M=0
	m="${2:-0}"

	IFS=.
	set -- ${1}
	unset IFS

	M=${1:-${M}}
	m=${2:-${m}}

	checkints $M $m

	printf "$((${M} * 100 + ${m}))\n"
}


jit2num() {
	M=0
	m="${2:-0}"
	p="${3:-0}"

	IFS=.
	set -- ${1}
	unset IFS

	M=${1:-${M}}
	m=${2:-${m}}
	p=${3:-${p}}

	checkints $M $m $p

	printf "$((${M} * 10000 + ${m} * 100 + ${p}))\n"
}


findlua() {
	while [ $# -gt 0 ]; do
		for F in $(findpath "${1}" no "${PATH}"; findpath "${1}" "${RECURSE}" "${BINDIRS}"); do
			[ -x "$F" ] && safeperm "$F" || continue

			V="$($F -e 'print(string.match(_VERSION, [[[%d.]+]]))' </dev/null 2>>/dev/null | head -n1 | sed -ne 's/^\([0123456789][0123456789]*\.[0123456789][0123456789]*\).*/\1/p')"
			: ${V:=0}
			V="$((${V%%.*} * 100 + ${V##*.} % 100))"

			[ "${V}" -gt 0 -a "${V}" -ge "${LUA_VER:-0}" ] || continue

			[ "${V}" -gt "${LUA_VER:-0}" -o "${#F}" -lt "${#LUA_PATH}" ] || continue

			[ "${V}" -ge "${API_MIN}" -a "${V}" -le "${API_MAX}" ] || continue

			if [ -n "${JIT_REQ}" ]; then
				J="$($F -v </dev/null 2>&1 | head -n1 | sed -ne 's/^LuaJIT \([0123456789][0123456789]*\.[0123456789][0123456789]*\.[0123456789][0123456789]*\).*/\1/p')"
				J="$(jit2num ${J:-0})"

				if [ "${JIT_REQ}" = "skip" ]; then
					[ "${J}" -eq 0 ] || continue
				elif [ "${JIT_REQ}" = "yes" ]; then
					[ "${J}" -gt 0 ] || continue
					[ "${J}" -ge "${JIT_MIN}" ] || continue
					[ "${J}" -le "${JIT_MAX}" ] || continue
				fi
			fi

			LUA_PATH="$F"
			LUA_VER="$V"

			[ "${SHORTEST}" = "yes" -o "${LUA_VER}" -lt "${API_MAX}" ] || break 2
		done

		shift
	done
}


usage() {
	cat <<-EOF
	usage: ${0##*/} [-I:L:P:d:Dkrm:xsv:j:JVh] cppflags|ldflags|version|lua|luac
	  -I PATH      additional search directory for includes
	  -L PATH      additional search directory for libraries
	  -P PATH      additional search directory for binaries
	  -d PATH      use PATH as sandbox directory; a random 16 byte suffix is
	               generated from /dev/urandom and the directory removed on exit
	               unless a trailing "/" is present
	               (default sandbox is \$TMPDIR/${0##*/}-XXXXXXXXXXXXXXXX)
	  -D           do not create a sandbox
	  -k           query pkg-config if available
	  -r           recursively search directories
	  -m MAXDEPTH  limit recursion to MAXDEPTH (only for GNU and BSD find)
	  -x           do not cross device mounts when recursing
	  -s           find shortest pathname, otherwise print first best match
	  -v VERSION   require specific Lua version or range
	               (e.g. "5.1" or "5.1-5.2")
	  -j VERSION   require specific LuaJIT version or range
	               (e.g. "2.0.1"; empty ranges like "-" force any LuaJIT version)
	  -J           skip LuaJIT if encountered
	  -V           print this script's version information
	  -h           print this usage message

	  cppflags     print derived additional CPPFLAGS necessary
	  ldflags      print derived additional LDFLAGS necessary (TODO)
	  version      print derived Lua API version
	  luac [GLOB]  print path to luac utility using optional glob patterns
	               (e.g. "luac5.?"; default is "luac*")
	  lua [GLOB]   print path to lua interpreter using optional glob patterns
	               (e.g. "lua luajit"; default is "lua*")
	  evalmacro    run internal macro evaluator for debugging
	  testsym      run internal library symbol reader for debugging

	This utility is used to derive compiler flags and filesystem paths
	necessary to utilize Lua, LuaJIT, and particular versions thereof.
	On success it prints the requested information and exits with 0,
	otherwise it fails with an exit status of 1.

	Note that cppflags may not print anything if no additional flags are
	required to compile against the requested API version.

	When searching, the highest Lua version is preferred. Searching
	stops once the highest version in the allowable range is found
	unless the -s flag is specified.

	LuaJIT is treated like any other Lua installation. If an explicit
	LuaJIT version or range is specified, then only LuaJIT installations
	will match. To exclude LuaJIT entirely use the -J switch.

	This utility processes the environment variables CC, CPPFLAGS,
	LDFLAGS, and PATH if present. If recursion is requested, then
	directories specified in CPPFLAGS, LDFLAGS, and PATH are also
	recursed.

	If the environment variable CPPFLAGS is empty and no -I options are
	specified directly, then /usr/include and /usr/local/include are
	used when probing for cppflags and API version.

	Report bugs to <william@25thandClement.com>
	EOF
}


version() {
	cat <<-EOF
	luapath $MYVERSION
	vendor  $MYVENDOR
	release $MYVERSION
	EOF
}


while getopts I:L:P:d:Dkrm:xsv:j:JVh OPT; do
	case "${OPT}" in
	I)
		INCDIRS="${INCDIRS:-}${INCDIRS:+:}${OPTARG}"
		;;
	L)
		LIBDIRS="${LIBDIRS:-}${LIBDIRS:+:}${OPTARG}"
		;;
	P)
		BINDIRS="${BINDIRS:-}${BINDIRS:+:}${OPTARG}"
		;;
	d)
		SANDBOX="${OPTARG}"
		;;
	D)
		SANDBOX=
		;;
	k)
		PKGCONFIG="$(command -v pkg-config || true)"
		;;
	r)
		RECURSE=yes
		;;
	m)
		if [ -n "${OPTARG##[0123456789]}" ]; then
			printf -- "${0##*/}: ${OPTARG}: invalid maxdepth\n" >&2
			exit 1
		fi

		if find "${TMPDIR:-/tmp}" -maxdepth ${OPTARG} -prune >>/dev/null 2>&1; then
			MAXDEPTH="-maxdepth ${OPTARG}"
		else
			printf -- "${0##*/}: $(command -v find): -maxdepth unsupported\n" >&2
		fi

		;;
	x)
		XDEV="-xdev"
		;;
	s)
		SHORTEST=yes
		;;
	v)
		MIN=${OPTARG%%[,:-]*}
		MAX=${OPTARG##*[,:-]}

		API_MIN="$(lua2num ${MIN:-0} 0)"
		API_MAX="$(lua2num ${MAX:-99} 99)"

		if [ "${API_MIN}" -gt "${API_MAX}" ]; then
			printf -- "${0##*/}: ${OPTARG}: invalid version range\n" >&2
			exit 1
		fi

		;;
	j)
		MIN=${OPTARG%%[,:-]*}
		MAX=${OPTARG##*[,:-]}

		JIT_MIN="$(jit2num ${MIN:-0} 0 0)"
		JIT_MAX="$(jit2num ${MAX:-99} 99 99)"

		if [ "${JIT_MIN}" -gt "${JIT_MAX}" ]; then
			printf -- "${0##*/}: ${OPTARG}: invalid version range\n" >&2
			exit 1
		fi

		JIT_REQ=yes
		;;
	J)
		JIT_REQ=skip
		;;
	V)
		version
		exit 0
		;;
	h)
		usage
		exit 0
		;;
	*)
		usage >&2
		exit 1
		;;
	esac
done

shift $(($OPTIND - 1))


for U in ${CC:-cc} find grep od rm rmdir sed xargs; do
	if ! command -v ${U} >>/dev/null 2>&1; then
		printf -- "${0##*/}: ${U}: command not found\n" >&2
	fi
done


if [ -n "${SANDBOX}" ]; then
	if [ "${SANDBOX}" = "${SANDBOX%/}" ]; then
		if [ ! -c "${DEVRANDOM}" ]; then
			# TODO: expand DEVRANDOM into set of different possibilities to check
			printf -- "${0##*/}: ${DEVRANDDOM}: no character random device available\n" >&2
			exit 1
		fi

		TMP="${SANDBOX}$(od -An -N8 -tx1 < ${DEVRANDOM} 2>>/dev/null | tr -d ' 	')"

		if [ ${#TMP} -ne $((${#SANDBOX} + 16)) ]; then
			printf -- "${0##*/}: ${SANDBOX}: unable to generate random suffix\n" >&2
			exit 1
		fi

		SANDBOX="${TMP}"

		trap "cd .. && rm -f -- ${SANDBOX}/* && rmdir -- ${SANDBOX}" EXIT
	fi

	if [ ! -d "${SANDBOX}" ]; then
		OMASK="$(umask)"
		umask 0777
		mkdir -m0550 -- "${SANDBOX}" || exit 1
		umask ${OMASK}
	fi

	cd ${SANDBOX}
fi


CPPDIRS="$(idirs "${CPPFLAGS:-}")"

if [ -z "${CPPDIRS}" -a -z "${INCDIRS}" ]; then
	INCDIRS="/usr/include:/usr/local/include"
fi


LDDIRS="$(ldirs "${LDFLAGS:-}")"

if [ -z "${LDDIRS}" -a -z "${LIBDIRS}" ]; then
	LIBDIRS="/lib:/usr/lib:/usr/local/lib"
fi


case "${1:-}" in
cppflags)
	findversion

	[ "${API_VER:-0}" -gt 0 ] || exit 1

	[ -z "${API_DIR:-}" ] || printf -- "-I${API_DIR}\n"

	;;
ldflags)
	findlib

	[ "${LIBLUA_VER:-0}" -gt 0 ] || exit 1

	printf -- "-L${LIBLUA_DIR} -l${LIBLUA_LIB}\n"

	;;
version)
	findversion

	[ "${API_VER:-0}" -gt 0 ] || exit 1

	printf "$(((${API_VER} / 100) % 100)).$((($API_VER) % 100))\n"

	;;
libv*)
	findlib

	[ "${LIBLUA_VER:-0}" -gt 0 ] || exit 1

	printf "$(((${LIBLUA_VER} / 100) % 100)).$((($LIBLUA_VER) % 100))\n"

	;;
luac)
	shift

	if [ $# -eq 0 ]; then
		set -- luac\*
	fi

	findluac $*

	[ -n "${LUAC_PATH}" ] || exit 1
	
	printf -- "${LUAC_PATH}\n"

	;;
lua)
	shift

	if [ $# -eq 0 ]; then
		set -- lua\*
	fi

	findlua $*

	[ -n "${LUA_PATH}" ] || exit 1
	
	printf -- "${LUA_PATH}\n"

	;;
evalmacro)
	shift

	evalmacro  $*
	;;
testsym)
	shift

	if testsym $*; then
		printf "found\n"
		exit 0
	else
		printf "not found\n"
		exit 1
	fi
	;;
*)
	if [ -n "${1:-}" ]; then
		printf -- "${0##*/}: ${1}: unknown command\n" >&2
	else
		printf -- "${0##*/}: no command specified\n" >&2
	fi

	exit 1
	;;
esac

exit 0