added missing file + code cleanup

contrib/db/libmdbx/CMakeLists.txt

@@ -14,14 +14,6 @@ endif()
 
 include_directories("${CMAKE_CURRENT_SOURCE_DIR}")
 
-if(NOT MSVC)
-  # set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-missing-field-initializers -Wno-missing-braces -Wno-aggregate-return")
-endif()
-
-if(FREEBSD)
-  # add_definitions(-DMDB_DSYNC=O_SYNC)
-endif()
-
 add_library(mdbx  ${mdbx_sources})
 
 target_link_libraries(mdbx PRIVATE ${CMAKE_THREAD_LIBS_INIT})

src/common/db_backend_selector.h

@@ -0,0 +1,21 @@
+// Copyright (c) 2014-2019 Zano Project
+// Copyright (c) 2014-2018 The Louisdor Project
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#pragma once
+
+#include "db_backend_lmdb.h"
+#include "db_backend_mdbx.h"
+
+namespace tools
+{
+  namespace db
+  {
+#ifdef DB_ENGINE_LMDB
+    typedef lmdb_db_backend default_db_backend;
+#elif DB_ENGINE_MDBX
+    typedef mdbx_db_backend default_db_backend;
+#endif
+  }
+}