if(CMAKE_GENERATOR MATCHES "Unix Makefiles" OR CMAKE_GENERATOR MATCHES "MinGW Makefiles")
set(CLEAN_COMMAND make clean)
elseif(CMAKE_GENERATOR MATCHES "NMake Makefiles")
if(CMAKE_GENERATOR MATCHES "Unix Makefiles" OR CMAKE_GENERATOR MATCHES "MinGW Makefiles")
set(CLEAN_COMMAND make clean)
elseif(CMAKE_GENERATOR MATCHES "NMake Makefiles")