- move `CGAL_WARNING` in `<CGAL/config.h>`, - create the macro `CGAL_pragma_warning`, - use `CGAL_pragma_warning` to simplify `<CGAL/license/lgpl.h>` and `<CGAL/license/gpl.h.in>`. - add messages in `include/CGAL/license/generate_files.cmake` - add test files, that do nothing but can be modified to check errors and warning.