supress CMP0048 warning

CMakeLists.txt

@@ -36,13 +36,13 @@ cat("${CMAKE_SUPPORT_DIR}/zlib_CMakeLists.txt.in" ${DEPS_TMP_FILE})
 cat("${CMAKE_SUPPORT_DIR}/cjson_CMakeLists.txt.in" ${DEPS_TMP_FILE})
 
 ## leveldb
-option(BUILD_WITH_LEVELDB "If build with leveldb" ON)
+option(BUILD_WITH_LEVELDB "If build with leveldb" OFF)
 if(${BUILD_WITH_LEVELDB})
     cat("${CMAKE_SUPPORT_DIR}/leveldb_CMakeLists.txt.in" ${DEPS_TMP_FILE})
 endif(${BUILD_WITH_LEVELDB})
 
 ## rocksdb
-option(BUILD_WITH_ROCKSDB "If build with rocksdb" ON)
+option(BUILD_WITH_ROCKSDB "If build with rocksdb" OFF)
 if(${BUILD_WITH_ROCKSDB})
     cat("${CMAKE_SUPPORT_DIR}/rocksdb_CMakeLists.txt.in" ${DEPS_TMP_FILE})
 endif(${BUILD_WITH_ROCKSDB})

cmake/EnableCMP0048.txt.in

+cmake_policy(SET CMP0048 NEW)
\ No newline at end of file

deps/CMakeLists.txt

@@ -4,12 +4,15 @@ if(${BUILD_TEST})
 endif(${BUILD_TEST})
 
 # cJson
+# see https://stackoverflow.com/questions/37582508/silence-cmp0048-warnings-in-vendored-projects
+set(CMAKE_PROJECT_INCLUDE_BEFORE "${CMAKE_SUPPORT_DIR}/EnableCMP0048.txt.in")
 add_subdirectory(cJson)
 target_include_directories(
     cjson
     # see https://stackoverflow.com/questions/25676277/cmake-target-include-directories-prints-an-error-when-i-try-to-add-the-source
     PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/cJson>
 )
+unset(CMAKE_PROJECT_INCLUDE_BEFORE)
 
 # lz4
 add_subdirectory(lz4/build/cmake)
@@ -19,12 +22,14 @@ target_include_directories(
 )
 
 # zlib
+set(CMAKE_PROJECT_INCLUDE_BEFORE "${CMAKE_SUPPORT_DIR}/EnableCMP0048.txt.in")
 add_subdirectory(zlib)
 target_include_directories(
     zlib
     PUBLIC ${CMAKE_CURRENT_BINARY_DIR}/zlib
     PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}/zlib
 )
+unset(CMAKE_PROJECT_INCLUDE_BEFORE)
 
 # leveldb
 if(${BUILD_WITH_LEVELDB})