# Check if asio folder is empty and clone submodule if needed file(GLOB RESULT "${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/asio/asio/include") list(LENGTH RESULT RES_LEN) if(RES_LEN EQUAL 0) message(STATUS "Asio not found, cloning it...") execute_process(COMMAND git submodule update --init -- 3rdparty/asio WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}") endif() add_library(asio INTERFACE IMPORTED) set_property(TARGET asio PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${CMAKE_CURRENT_SOURCE_DIR}/3rdparty/asio/asio/include")