Clang is a new front-end for LLVM, written completely from scratch,
which is more-or-less feature complete for C99 and Objective-C 2
(parsing anyway - code generation is only finished for the Apple
runtimes), and now working towards C++ support.
Is this what you were using to try and compile GNustep base ? I
have just soent a while playing around with the llvm port on
FreeBSD (which seems to be lacking the compiler driver). Had some
success with plain old C, but not a lot with ObjC, eeven when I am not
doing anything objecty. e.g: