add_library(iface INTERFACE)
target_sources(iface INTERFACE $<TARGET_OBJECTS:NoTarget>)

file(GENERATE OUTPUT test_output CONTENT $<TARGET_OBJECTS:NoTarget>)
file(GENERATE OUTPUT test_output2 CONTENT $<TARGET_PROPERTY:iface,INTERFACE_SOURCES>)

install(FILES $<TARGET_OBJECTS:NoTarget> DESTINATION objects)