[PATCH v2 14/21] kconfig: add CC_IS_CLANG and CLANG_VERSION

[Masahiro Yamada]

This will be useful to describe the clang version dependency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
---

Changes in v2: None

 init/Kconfig             |  7 +++++++
 scripts/clang-version.sh | 24 +++++++++++-------------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/init/Kconfig b/init/Kconfig
index 923cab5..5998034 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -22,6 +22,13 @@ config GCC_VERSION
 	default $(shell $srctree/scripts/gcc-version.sh -p $CC | sed 's/^0*//') if CC_IS_GCC
 	default 0
 
+config CC_IS_CLANG
+	def_bool $(success $CC --version | grep -q clang)
+
+config CLANG_VERSION
+	int
+	default $(shell $srctree/scripts/clang-version.sh $CC)
+
 config CONSTRUCTORS
 	bool
 	depends on !UML
diff --git a/scripts/clang-version.sh b/scripts/clang-version.sh
index 9780efa..d8002d2 100755
--- a/scripts/clang-version.sh
+++ b/scripts/clang-version.sh
@@ -10,24 +10,22 @@
 # 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"
+	echo "Error: No compiler specified." >&2
+	printf "Usage:\n\t$0 <clang-command>\n" >&2
+	echo 0
+	exit 1
+fi
+
+if !( $compiler --version | grep -q clang) ; then
+	echo "This is not clang." >&2
+	echo 0
 	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 $MINOR
-fi
+PATCHLEVEL=$(echo __clang_patchlevel__ | $compiler -E -x c - | tail -n 1)
+printf "%d%02d%02d\\n" $MAJOR $MINOR $PATCHLEVEL
-- 
2.7.4