How to compile/include unrarsrc in an objective-c project?

Question

I'm trying to replicate the unrar functionality in this project:

http://github.com/tarasis/QuietUnrar

But having trouble. I have copied the relevant files (/libunrar/,QuietUnrarAppDelegate.) into my project so I can turn QuietUnrarAppDelegate into a more generalised Unrar class, and immediately I run into problems. All the source files in /libunrar throw countless errors when I try and include them in my project - I presume this is just a question of settings, but I'm unable to work out what to do to get the source to compile. I see that it compiles into libunrar.so, but I... don't get how.

This is probably a moment's work for some C++ veteran - anyone want to point me in the right direction? I have done enough fruitless googling that I think karmically it would be fine for someone to hold my hand a bit.