[CMake] Manner to manage the dependencies

[Alexander Neundorf]

On Monday 25 October 2010, Weiyu Yi wrote:
> Hi,
>
> This is Weiyu, a student from University of Germany.  I have used
> CMake as the build system instead of autotool already for some
> projects. but I am still not sure about the way how the libraries
> dependencies should be handled,  is there any suggestion from CMAKE
> group that how the dependencies within the project are dealed with?
>
> I have roughly read the cmake files from KDE 4.0+ and OpenSG 2.0 beta.
>  The build system from OpenSG 2.0 seems too complicated for my code
> where there are only less than 10 parts(directories) of source codes.
> OpenSG 2.0 saves the dependencies and the information for building
> into txt files in order to manage great mount of dependencies
>
> While the cmake files from KDE 4.0 seems too simple, or?

Thanks for the compliment ! :-)
Building KDE is complex, it's nice that you consider the files simple :-)

> The way I use cmake now is like that :
>
> ---------------------------------------------------------------------------
>--------
>
> 1) write some macro and functions in a separate file, and
>
> 2) for each separate part(directoriy) of my codes with sub-project
> name "XXX", I make a FindXXX.cmake file, which will be called to
> handle the dependency
>
> 3) CMakeLists.txt in each directory, like
>
> ADD_INTERNAL_DEPENDENCY( XXX )
> SETUP_LIBRARY_BUILD()
>
> ---------------------------------------------------------------------------
>--------
>
> But the way how i use the mechanism of FindXXX.cmake and FIND_PACKAGE(
> XXX ) is not the suggested way from the CMake group
>
> because the library hasn't been created while cmake is processing. so
> FIND_LIBRARY() doesn't work, I use find_path() or direct assignment
> instead
>
> Is it a good way how to deal with dependencies with CMAKE?

CMake handles the dependencies automatically, you don't have to do anything 
special additionally.
Just go into subdirs using 
add_subdirectory(),
create the libraries there using 
add_library(myLibrary ...)
and then use these libraries via
target_link_libraries(myExecutable ... myLibrary)

Alex