specific_ss.add(files('accel-common.c')) softmmu_ss.add(files('accel-softmmu.c')) user_ss.add(files('accel-user.c')) subdir('hvf') subdir('qtest') subdir('kvm') subdir('tcg') subdir('xen') subdir('stubs') dummy_ss = ss.source_set() dummy_ss.add(files( 'dummy-cpus.c', )) specific_ss.add_all(when: ['CONFIG_SOFTMMU', 'CONFIG_POSIX'], if_true: dummy_ss) specific_ss.add_all(when: ['CONFIG_XEN'], if_true: dummy_ss)