Merge pull request #1932 from emailweixu/fix_proj_root

Change PROJ_ROOT in CMakeList.txt to use CMAKE_CURRENT_SOURCE_DIR

CMakeLists.txt

@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License
 
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake")
-set(PROJ_ROOT ${CMAKE_SOURCE_DIR})
+set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake")
+set(PROJ_ROOT ${CMAKE_CURRENT_SOURCE_DIR})
 
 include(system)