[CMake] Why doesn't cmake generate the file?

[Bill Hoffman]

Jörg Förstner wrote:
> Hi,
> -----------------------
> So the big question is:
> -----------------------
> Why do I need to manually add "gen.h" to the ADD_LIBRARY() command?
> 
To let CMake know it is a generated file.

When the depend scanner runs the file will not be there.

It is just how it works.

-Bill