CMakeLists.txt

Defining main-target
...

add_custom_target(generate_version_header
    COMMAND ${CMAKE_COMMAND}
     -DVERSION_TEMPLATE:STRING=version.hpp.in 
     -DVERSION_FILE:STRING=version.hpp
     -DSOURCE_DIR:STRING=${CMAKE_SOURCE_DIR}
     -P ${CMAKE_SOURCE_DIR}/generate_version_header.cmake
    COMMENT "Generating version header"
)

add_dependencies(main-target generate_version_header)