UPSTREAM: kbuild: add clang-version.sh

#!/bin/sh

# SPDX-License-Identifier: GPL-2.0

#

# clang-version [-p] clang-command

#

# Prints the compiler version of `clang-command' in a canonical 4-digit form

# such as `0500' for clang-5.0 etc.

#

# With the -p option, prints the patchlevel as well, for example `050001' for

# clang-5.0.1 etc.

#

if [ "$1" = "-p" ] ; then

	with_patchlevel=1;

	shift;

fi

compiler="$*"

if [ ${#compiler} -eq 0 ]; then

	echo "Error: No compiler specified."

	printf "Usage:\n\t$0 <clang-command>\n"

	exit 1

fi

MAJOR=$(echo __clang_major__ | $compiler -E -x c - | tail -n 1)

MINOR=$(echo __clang_minor__ | $compiler -E -x c - | tail -n 1)

if [ "x$with_patchlevel" != "x" ] ; then

	PATCHLEVEL=$(echo __clang_patchlevel__ | $compiler -E -x c - | tail -n 1)

	printf "%02d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL

else

	printf "%02d%02d\\n" $MAJOR $MINOR

fi