removed msvc compilation support

cmake/rocksdb.cmake

@@ -26,58 +26,40 @@ set(ROCKSDB_CMAKE_ARGS
   -DWITH_TOOLS=OFF
 )
 
-if(MSVC)
+if (MINGW)
+  if (CMAKE_TOOLCHAIN_FILE)
+    set(ROCKSDB_CMAKE_ARGS
+      ${ROCKSDB_CMAKE_ARGS}
+      -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE} 
+    )
+  endif()
+
   ExternalProject_Add(rocksdb_project
     DOWNLOAD_NO_PROGRESS 1
     URL https://github.com/facebook/rocksdb/archive/v${ROCKSDB_VERSION}.tar.gz
     PREFIX ${ROCKSDB_BUILD_ROOT}
-    CMAKE_ARGS ${ROCKSDB_CMAKE_ARGS} 
+    CMAKE_ARGS ${ROCKSDB_CMAKE_ARGS} -DWITH_GFLAGS=OFF
     INSTALL_COMMAND ${CMAKE_COMMAND} -E echo "Skipping install step."
   )
 
-  set(ROCKSDB_INCLUDE_DIRS ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project/include)
-
-  if (CMAKE_GENERATOR_LOWER STREQUAL "nmake makefiles")
-    set(ROCKSDB_LIBRARIES ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project-build/rocksdb.lib)
-  else ()
-    set(ROCKSDB_LIBRARIES ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project-build/${CMAKE_BUILD_TYPE}/rocksdb.lib)
-  endif ()
+  set(ROCKSDB_LIBRARIES ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project-build/librocksdb.a)
+  include_directories(SYSTEM ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project/include)
 else()
-  if (MINGW)
-    if (CMAKE_TOOLCHAIN_FILE)
-      set(ROCKSDB_CMAKE_ARGS
-        ${ROCKSDB_CMAKE_ARGS}
-        -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE} 
-      )
-    endif()
+  ExternalProject_Add(rocksdb_project
+    DOWNLOAD_NO_PROGRESS 1
+    URL https://github.com/facebook/rocksdb/archive/v${ROCKSDB_VERSION}.tar.gz
+    PREFIX ${ROCKSDB_BUILD_ROOT}
+    CMAKE_ARGS ${ROCKSDB_CMAKE_ARGS} -DWITH_GFLAGS=OFF
+  )
 
-    ExternalProject_Add(rocksdb_project
-      DOWNLOAD_NO_PROGRESS 1
-      URL https://github.com/facebook/rocksdb/archive/v${ROCKSDB_VERSION}.tar.gz
-      PREFIX ${ROCKSDB_BUILD_ROOT}
-      CMAKE_ARGS ${ROCKSDB_CMAKE_ARGS} -DWITH_GFLAGS=OFF
-      INSTALL_COMMAND ${CMAKE_COMMAND} -E echo "Skipping install step."
-    )
-
-    set(ROCKSDB_LIBRARIES ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project-build/librocksdb.a)
-    include_directories(SYSTEM ${ROCKSDB_BUILD_ROOT}/src/rocksdb_project/include)
+  if (MACOS)
+    set(ROCKSDB_LIBRARIES ${EXTERNAL_BUILD_ROOT}/lib/librocksdb.a)
   else()
-    ExternalProject_Add(rocksdb_project
-      DOWNLOAD_NO_PROGRESS 1
-      URL https://github.com/facebook/rocksdb/archive/v${ROCKSDB_VERSION}.tar.gz
-      PREFIX ${ROCKSDB_BUILD_ROOT}
-      CMAKE_ARGS ${ROCKSDB_CMAKE_ARGS} -DWITH_GFLAGS=OFF
-    )
-
-    if (MACOS)
-      set(ROCKSDB_LIBRARIES ${EXTERNAL_BUILD_ROOT}/lib/librocksdb.a)
-    else()
-      set(ROCKSDB_LIBRARIES librocksdb.a)
-    endif()
+    set(ROCKSDB_LIBRARIES librocksdb.a)
   endif()
 endif()
 
-if (MSVC OR LINUX OR MINGW)
+if (LINUX OR MINGW)
   add_dependencies(rocksdb_project curl_project)
 endif()