I recommend using sloccount, you will get the LOC by directories and files as expected. You won't be able to have the LOC by class however.
If this limitation is ok, just use the --details
flag in the command line you are using, for example if you run the sloccount command in the root directory of your Xcode project::
sloccount --duplicates --wide --details YOUR-TARGET-NAME
The output is a bit hard to read but you will get all the information you need.
If you want to have a nice report and be able to drill down in the directories/files via a HTML report, I suggest using Jenkins. Just install the 'Jenkins plugin for sloccount' via Jenkins UI.
You can see how to setup it in this blog article (disclaimer: I am the author). You will also be able to see examples of such reports.