devel/dmlc-core: use clang on architectures without openmp and disabl…

…e openmp

devel/dmlc-core/Makefile

@@ -9,19 +9,15 @@ COMMENT=	Common library for scalable and portable distributed machine learning
 
 LICENSE=	APACHE20
 
-USES=		cmake
+USES=		cmake compiler:c++11-lang
 USE_GITHUB=	yes
 GH_ACCOUNT=	dmlc
 USE_LDCONFIG=	yes
 
 CMAKE_ON=	BUILD_SHARED_LIBS
 
-.include <bsd.port.options.mk>
-
-.if ${ARCH} == powerpc
-USES+=		compiler:gcc-c++11-lib
-.else
-USES+=		compiler:c++11-lang
+.if !exists(/usr/include/omp.h)
+CMAKE_ARGS+=	-DUSE_OPENMP:BOOL=OFF
 .endif
 
 .include <bsd.port.mk>