kbuild: add clang-version.sh

Based on gcc-version.sh, clang-version.sh prints out the correct
version of clang.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/scripts/clang-version.sh b/scripts/clang-version.sh
new file mode 100755 (executable)
index 0000000..9780efa
--- /dev/null
+++ b/scripts/clang-version.sh
@@ -0,0 +1,33 @@
+#!/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