cmake_policy(SET CMP0050 OLD) add_library(empty empty.cpp) add_custom_command( TARGET empty SOURCE ${CMAKE_CURRENT_SOURCE_DIR}/input.h.in COMMAND ${CMAKE_COMMAND} ARGS -E copy ${CMAKE_CURRENT_SOURCE_DIR}/input.h.in ${CMAKE_CURRENT_BINARY_DIR}/input.h OUTPUTS ${CMAKE_CURRENT_BINARY_DIR}/input.h DEPENDS ${CMAKE_COMMAND} )