add_library(test SHARED dummy.cpp)
add_custom_command(TARGET test PRE_BUILD
                   COMMAND g++ -shared ${CMAKE_CURRENT_SOURCE_DIR}/dummy.cpp -o ${CMAKE_CURRENT_BINARY_DIR}/test.so
                  )
add_custom_command(TARGET test POST_BUILD
                   COMMAND ${CMAKE_COMMAND} -E rename ${CMAKE_CURRENT_BINARY_DIR}/test.so ${LIBRARY_OUTPUT_PATH}/libtest.so
                  )
