add_definitions() and -U flag

[Dmitry Suzdalev]

Hi!

Is it intentional that add_definitions() doesn't support "-U" gcc flag?

For example, when I try to do the following

add_definitions( -UQT3_SUPPORT )

it doesn't show up in make VERBOSE=1 output.
If I add something with "-D" - then it's OK.

Bug/feature/me_doing_something_wrong? :)

Thanks.
Dmitry.

PS. One more thing - I'm just curious :). I see set(KDE4_DEFINITIONS ....) in 
kdelibs' FindKDE4Internal.cmake, but where does it gets passed to cmake? 
Can't find it with grep ;). Or cmake internals know about KDE4_DEFINITIONS 
variable and pick it up?