cmake dependencies questions

[Alexander Dymo]

Hi! Can anybody look through the
http://websvn.kde.org/trunk/KDE/kdevelop/cmake/modules/KDevelopMacros.cmake?rev=519021&sortby=date&view=markup

This macro should look into some dirs and tar some files from those dirs.
Resulting archive should be installed. 
For example, if I have
- dir_a
	file_a
	file_b
	file_c
- dir_b
	file_a
	file_b
	file_c
Then the macro will produce
dir_a.tar.bz2
dir_b.tar.bz2

It works well but I'd like to add a dependency
between dir_a.tar.bz2 and file_a, file_b and file_c.
I collect a list of deps in ${_deps} variable, and pass it to the DEPENDS
in add_custom_command.
But this doesn't work like I want because if file_a is a cpp source file 
(smth.cpp) it gets compiled which is not wanted.
Is there any other way to list dependencies and avoid compilation?