cmake ALLEGRO_HAVE_SYS_IO_H examples

liballeg/allegro5 CMakeLists.txt :508 

check_include_files(sys/io.h ALLEGRO_HAVE_SYS_IO_H)

adventuregamestudio/ags libsrc/allegro/CMakeLists.txt :42 

check_include_files(sys/io.h ALLEGRO_HAVE_SYS_IO_H)