CI: add clang build for travis-ci

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

.travis.yml

@@ -5,6 +5,7 @@ services:
   - docker
 env:
   - TR_ARCH=local       GCOV=1
+  - TR_ARCH=local       GCOV=0  CLANG=1
   - TR_ARCH=x86_64      GCOV=1
   - TR_ARCH=armv7hf     GCOV=1
   - TR_ARCH=aarch64     GCOV=1

scripts/travis/travis-tests

@@ -12,6 +12,10 @@ travis_prep () {
 	apt-get install -qq protobuf-c-compiler libprotobuf-c0-dev libaio-dev	\
 		libprotobuf-dev protobuf-compiler python-ipaddr libcap-dev	\
 		libnl-3-dev gdb bash python-protobuf
+		if [ "$CLANG" = "1" ]; then
+			apt-get install -qq clang
+			MAKE_VARS=CC=clang
+		fi
 	chmod a+x $HOME
 }
 
@@ -21,8 +25,8 @@ ulimit -c unlimited
 echo "|`pwd`/test/abrt.sh %P %p %s %e" > /proc/sys/kernel/core_pattern
 
 export GCOV
-make
-make -C test/zdtm
+make $(MAKE_VARS)
+make $(MAKE_VARS) -C test/zdtm
 
 ./criu/criu check
 ./criu/criu check --all || echo $?