fix mac build (#11873)

* fix mac build

* add notes

* fix_mac_build

* update

CMakeLists.txt

@@ -65,6 +65,7 @@ option(REPLACE_ENFORCE_GLOG "Replace PADDLE_ENFORCE with glog/CHECK for better d
 option(WITH_ANAKIN      "Compile with Anakin library"                   OFF)
 option(WITH_GRPC     "Use grpc as the default rpc framework"            ${WITH_DISTRIBUTE})
 option(WITH_BRPC_RDMA     "Use brpc rdma as the rpc protocal"           OFF)
+option(WITH_SYSTEM_BLAS   "Use system blas library"           OFF)
 
 # CMAKE_BUILD_TYPE
 if(NOT CMAKE_BUILD_TYPE)

cmake/cblas.cmake

@@ -83,6 +83,7 @@ else()
   set(REFERENCE_CBLAS_LIB_SEARCH_PATHS ${REFERENCE_CBLAS_ROOT}/lib)
 endif()
 
+if(WITH_SYSTEM_BLAS)
   find_path(REFERENCE_CBLAS_INCLUDE_DIR NAMES cblas.h PATHS
         ${REFERENCE_CBLAS_INCLUDE_SEARCH_PATHS})
   find_library(REFERENCE_CBLAS_LIBRARY NAMES cblas PATHS
@@ -96,6 +97,7 @@ if(REFERENCE_CBLAS_INCLUDE_DIR AND REFERENCE_CBLAS_LIBRARY)
     add_definitions(-DPADDLE_USE_REFERENCE_CBLAS)
     message(STATUS "Found reference-cblas (include: ${CBLAS_INC_DIR}, library: ${CBLAS_LIBRARIES})")
   endif()
+endif()
 
 if(IOS_USE_VECLIB_FOR_BLAS AND VECLIB_FOUND)
   set(CBLAS_FOUND ON)