
add_custom_rule(simple OUTPUT <CURRENT_BINARY_DIR>/<BASE_NAME>.c
  COMMAND "${CMAKE_COMMAND}" -E copy <SOURCE> <CURRENT_BINARY_DIR>
  COMMAND "${CMAKE_COMMAND}" -E rename <CURRENT_BINARY_DIR>/<FILE_NAME> <CURRENT_BINARY_DIR>/<BASE_NAME>.c)

target_sources(foo PRIVATE FILE_SET fs TYPE simple BASE_DIRS ${CMAKE_SOURCE_DIR} FILES ../file.i)
