[CMake] add_custom_target always runs?

[Tyler Roscoe]

On Wed, Dec 17, 2008 at 08:45:01AM +0100, Martin Apel wrote:
> I had a similar problem some time ago. I worked around it by first
> generating the header files into ${CMAKE_CURRENT_BINARY_DIR} and then
> execute 'cmake -E
> copy_if_different' to their target location. This way dependent files
> will only be rebuilt, if the header has actually changed.

Good idea. I'll take this approach if I can't figure out how to do it
more "natively".

Thanks,
tyler