cmake/modules/BuildRocksDB.cmake: use string(APPEND ..) when appropriate

less repeatings this way.

Signed-off-by: Kefu Chai <tchaikov@gmail.com>

diff --git a/cmake/modules/BuildRocksDB.cmake b/cmake/modules/BuildRocksDB.cmake
index f9a28274c40d2d9e3d7f0383784a755a94981f49..f81f5248506dda0059a77c84bfe835c5d241c597 100644 (file)
--- a/cmake/modules/BuildRocksDB.cmake
+++ b/cmake/modules/BuildRocksDB.cmake
@@ -60,11 +60,11 @@ function(build_rocksdb)
   include(CheckCXXCompilerFlag)
   check_cxx_compiler_flag("-Wno-deprecated-copy" HAS_WARNING_DEPRECATED_COPY)
   if(HAS_WARNING_DEPRECATED_COPY)
-    set(rocksdb_CXX_FLAGS -Wno-deprecated-copy)
+    string(APPEND rocksdb_CXX_FLAGS " -Wno-deprecated-copy")
   endif()
   check_cxx_compiler_flag("-Wno-pessimizing-move" HAS_WARNING_PESSIMIZING_MOVE)
   if(HAS_WARNING_PESSIMIZING_MOVE)
-    set(rocksdb_CXX_FLAGS "${rocksdb_CXX_FLAGS} -Wno-pessimizing-move")
+    string(APPEND rocksdb_CXX_FLAGS " -Wno-pessimizing-move")
   endif()
   if(rocksdb_CXX_FLAGS)
     list(APPEND rocksdb_CMAKE_ARGS -DCMAKE_CXX_FLAGS='${rocksdb_CXX_FLAGS}')