Building FreeBSD-STABLE

[Norbert Aschendorff]

Hey,
I downloaded FreeBSD-STABLE source via SVN and I'm now at r241038 from
2012-09-28 22:29:06 +0200 (Fri, 28 Sep 2012).

If I want to build world (make buildworld), I get the following errors:
http://pastebin.com/raw.php?i=Yrs8JSwg

I've set the CC and CXX variables in make.conf to gcc respectively g++.
If I set CC and CXX to clang/clang++, the same error appears:

---
/usr/src/lib/clang/libllvmsupport/../../../contrib/llvm/lib/Support/APFloat.cpp:15:10:
fatal error: 'llvm/ADT/APFloat.h' file not found
#include "llvm/ADT/APFloat.h"
         ^
1 error generated.
---

The error stems obviously from C++ files including files from the wrong
place (following code taken from contrib/llvm/lib/Support/APInt.cpp):

#include "llvm/ADT/APInt.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"

The files included here are actually located at
contrib/llvm/include/llvm. As far as I currently see, all files needed
by the C++ files are there, so the only action which should be taken is
to change/add a C Preprocessor include switch in the correct Makefile,
right?

Or is the error located between chair and screen and I don't see the
solution?

--Norbert