add multi-thread static link for MAC

Makefile

@@ -21,9 +21,17 @@ endif
 ifeq ($(no_omp),1)
 	CFLAGS += -DDISABLE_OPENMP
 else
+	#CFLAGS += -fopenmp
+	ifeq ($(omp_mac_static),1)
+		#CFLAGS += -fopenmp -Bstatic
+		CFLAGS += -static-libgcc -static-libstdc++ -L. -fopenmp
+		#LDFLAGS += -Wl,--whole-archive -lpthread -Wl --no-whole-archive
+	else
 		CFLAGS += -fopenmp
+	endif
 endif
 
+
 # by default use c++11
 ifeq ($(cxx11),1)
 	CFLAGS += -std=c++11

build.sh

@@ -6,6 +6,18 @@
 
 # See additional instruction in doc/build.md
 
+#for building static OpenMP lib in MAC for easier installation in MAC
+#doesn't work with XCode clang/LLVM since Apple doesn't support, 
+#needs brew install gcc 4.9+ with OpenMP
+static_omp=1
+if ((${static_omp}==1)); then
+    rm libgomp.a
+    ln -s `g++ -print-file-name=libgomp.a`
+    make clean
+    make omp_mac_static=1
+    echo "Successfully build multi-thread static link xgboost"
+    exit 0
+fi
 
 if make; then
     echo "Successfully build multi-thread xgboost"