#!/bin/sh

# config.guess: an alternate implementation for modern (cross-)systems.

# modern-hosts: machine detection either via slibtool's --dumpmachine

#               output, or by way of a native compiler that implements

#               the -dumpmachine switch.

# this file is covered by COPYING.BAUTOMAKE.

# the order of attempted things:

#

# $NATIVE_CC

# $CC_FOR_BUILD

# c99

# cc

# ucc

# gcc

# clang

# cparser

set -eu

mb_script="$0"

mb_status=1

mb_dstamp='2021-06-11'

mb_target=

mb_extarg="${1:-}"

export LC_ALL=C

config_usage()

{

	printf 'usage:\n'                                   >&2

	printf '\t%s [OPTION]\n' "$mb_script"               >&2

	printf '\t%s (cross-)target-alias\n\n' "$mb_script" >&2

	printf 'Options:\n' >&2

	printf '\t%s\n'            \

		'-h, --help'       \

		'-t, --time-stamp' \

		'-v, --version'    \

		>&2

	printf '\nThis is an alternate config.guess implementation for modern (cross-)systems.' >&2

	printf '\nA native system is identified either via `slibtool --dumpmachine`, or by way' >&2

	printf '\n  of the -dumpmachine output of its priority native compiler.\n\n'            >&2

	printf 'Native compilers are tried in the following order:\n'                         >&2

	printf '\t%s\n' '$NATIVE_CC' '$CC_FOR_BUILD' 'c99' 'cc' 'ucc' 'gcc' 'clang' 'cparser' >&2

	printf '\npkgsite: https://git.foss21.org/bautomake' >&2

	printf '\npkgbugs: bugs.automake@foss21.org\n\n'     >&2

	exit ${mb_status}

}

config_output()

{

	printf '%s\n' "$mb_target"

	exit 0

}

for arg ; do

	case "$arg" in

		-h | --help)

			mb_status=0

			config_usage

			;;

		-t | --time-stamp)

			printf '%s\n' "$mb_dstamp"

			exit 0

			;;

		-v | --version)

			printf 'foss21.org config.guess (%s)\n' "$mb_dstamp"

			exit 0

			;;

		-*)

			printf '%s: the argument `%s is not supported.\n\n' "$mb_script" "$arg'" >&2

			exit 2

	esac

done

# no unused arguments

if [ -n "$mb_extarg" ]; then

	mb_status=2

	config_usage

fi

# try slibtool

if command -v slibtool > /dev/null 2>&1; then

	mb_target=$(slibtool --dumpmachine 2>/dev/null || true)

	if [ -n "$mb_target" ]; then

		config_output

	fi

fi

# explicit

mb_native_cc="${NATIVE_CC:-false}"

mb_cc_for_build="${CC_FOR_BUILD:-false}"

# try

for mb_cc_guess in "$mb_native_cc" "$mb_cc_for_build" c99 cc ucc gcc clang cparser; do

	mb_target=$($mb_cc_guess -dumpmachine 2>/dev/null || true)

	if [ -n "$mb_target" ]; then

		config_output

	fi

done

# fail

printf '%s: native compiler not found, or does not support -dumpmachine.\n\n' "$mb_script" >&2

exit 2