On 06/07/2011 06:23 PM, Bjørn Forsman wrote: > 2011/6/7 Michael Wild <them...@gmail.com>: >> On 06/07/2011 03:38 PM, Bjørn Forsman wrote: >>> Why not put find_package(Qt4) in the sub directories where it is actually >>> used? >> >> And if it is used in multiple subdirectories? > > What's bad about that? (Sorry, I really don't know).
Then you would need to call find_package in all the subdirectories, with all the work that goes along with that. > >> FindXXX.cmake modules should only do the minimum, i.e. finding the >> required libraries and include-directories, setting XXX_FOUND, >> XXX_INCLUDE_DIRS and XXX_LIBRARIES. Anything more complex, e.g. calling >> add_definitions(), include_directories(), function(), macro() etc. >> should go into a UseXXX.cmake module. > > Ok, I didn't know about that policy. > >> If you find a FindXXX.cmake module that calls add_definitions(), >> include_directories(), link_libraries() or some such, it is broken and >> needs to be fixed. > > Broken because of the above defined policy? Or of technical reasons? > Sorry, but I still don't see the reason why the current find_package + > use_file is better than a find_package that includes the use_file > itself. If the FindXXX.cmake file called add_definitions(), include_directories() et al., that could be potentially harmful. Some sources might required that some define is not set, or a wrong header file might be #include'ed (thing of all the different X.h that exist). FindXXX.cmake modules should just define a few variables, *not* change the build system. That's the caller's responsibility, either by calling the functions himself or by including the UseXXX.cmake (if provided). > > What I see is that current usage goes something like this: > > 1) find_package(Qt4 REQUIRED) at the top level > 2) subdirs that actually need Qt: set what modules to enable/disable > and then include the use_file. > > How about doing it this way: > 1) subdirs that actually need Qt: call find_package(Qt4 COMPONENTS > QtCore [...] REQUIRED) with the modules it needs. > > Is there a problem with this approach? Other than breaking the policy ;-) In principle not, except that all these redundant find_path() and find_library() calls will incur some slight overhead. Michael _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the CMake FAQ at: http://www.cmake.org/Wiki/CMake_FAQ Follow this link to subscribe/unsubscribe: http://www.cmake.org/mailman/listinfo/cmake
