src/CMakeLists.txt: FreeBSD/Clang fixes to compile RocksDB

 - make sure the right compiler is used
 - with the correct flags

Signed-off-by: Willem Jan Withagen <wjw@digiware.nl>

src/CMakeLists.txt

@@ -637,9 +637,14 @@ install(TARGETS ceph-mon DESTINATION bin)
 if(NOT ALLOCATOR STREQUAL "jemalloc")
   set(disable_jemalloc "DISABLE_JEMALLOC=1")
 endif()
+set(EXTRA_CXXFLAGS -fPIC -Wno-unused-variable -DNDEBUG)
+if(FREEBSD)
+  set(EXTRA_CXXFLAGS ${EXTRA_CXXFLAGS} -Irocksdb/include -I/usr/local/include)
+  set(MAKEFLAGS ${MAKEFLAGS})
+endif(FREEBSD)
 add_custom_target(build_rocksdb
     COMMAND
-    PORTABLE=1 ${disable_jemalloc} $(MAKE) static_lib EXTRA_CXXFLAGS='-fPIC -Wno-unused-variable'
+    PORTABLE=1 ${disable_jemalloc} $(MAKE) ${MAKEFLAGS} static_lib CXX="${CMAKE_CXX_COMPILER}" EXTRA_CXXFLAGS="${EXTRA_CXXFLAGS}"
     WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/src/rocksdb
     COMMENT "rocksdb building")