updated build system

cmake/libraries/rocksdb.cmake

@@ -2,7 +2,23 @@ if(PROJECT_ENABLE_ROCKSDB)
   if(PROJECT_BUILD)
     add_definitions(-DPROJECT_ENABLE_ROCKSDB)
     find_library(ROCKSDB_LIBRARY NAMES librocksdb.a REQUIRED)
-    link_libraries(${ROCKSDB_LIBRARY})
+
+    find_package(ZLIB REQUIRED)
+    include_directories(BEFORE SYSTEM ${ZLIB_INCLUDE_DIRS})
+
+    if(PROJECT_IS_MINGW_UNIX)
+      if(PROJECT_STATIC_LINK)
+        set(ROCKSDB_ZLIB_LIBRARY /mingw64/lib/libzs.a)
+      else()
+        set(ROCKSDB_ZLIB_LIBRARY /mingw64/lib/libz.dll.a)
+      endif()
+    else()
+      set(ROCKSDB_ZLIB_LIBRARY ${ZLIB_LIBRARIES})
+    endif()
+
+    link_libraries(
+      "-Wl,--start-group,${ROCKSDB_LIBRARY},${ROCKSDB_ZLIB_LIBRARY},--end-group"
+    )
   elseif(NOT PROJECT_IS_MINGW OR CMAKE_HOST_WIN32)
     ExternalProject_Add(rocksdb_project
       PREFIX external