[cfe-users] Failure building llvm/clang with gcc 4.7.2

[Edward Diener]

On Fedora 17 I attempt to build llvm/clang and receive the errors:

"llvm[0]: Constructing LLVMBuild project information.
gmake[1]: Entering directory `/home/fceldiener/dev/clang/build/lib/Support'
llvm[1]: Compiling APFloat.cpp for Debug+Asserts build
llvm[1]: Compiling APInt.cpp for Debug+Asserts build
llvm[1]: Compiling APSInt.cpp for Debug+Asserts build
llvm[1]: Compiling Allocator.cpp for Debug+Asserts build
In file included from 
/home/fceldiener/vcs/llvm/lib/Support/Allocator.cpp:14:
In file included from 
/home/fceldiener/vcs/llvm/include/llvm/Support/Allocator.h:19:
In file included from 
/home/fceldiener/vcs/llvm/include/llvm/Support/MathExtras.h:17:
In file included from 
/home/fceldiener/vcs/llvm/include/llvm/Support/SwapByteOrder.h:20:
/usr/bin/../lib/gcc/x86_64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/limits:1404:27: 
error: use of undeclared identifier
       '__int128'; did you mean '__int128_t'?
     struct numeric_limits<__int128>
                           ^
/usr/bin/../lib/gcc/x86_64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/limits:1478:36: 
error: expected '>'
     struct numeric_limits<unsigned __int128>
                                    ^
/usr/bin/../lib/gcc/x86_64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/limits:1478:5: 
error: cannot combine with previous '(error)'
       declaration specifier
     struct numeric_limits<unsigned __int128>
     ^
/usr/bin/../lib/gcc/x86_64-redhat-linux/4.7.2/../../../../include/c++/4.7.2/limits:1478:44: 
error: expected unqualified-id
     struct numeric_limits<unsigned __int128>"

There is more but the messages should suffice. Evidently 4.7.2 uses 
"__int28' instead of __int128_t' in its own header files and then does 
not accept this as valid ?

What do I do to work around this problem, or is it just that gcc 4.7.2 
is too new and the llvm configure script does not yet configure the 
makefiles correctly to build clang with it ?

Is it possible to use an earlier version of gcc and how do i set that up 
so that llvm/clang configure script finds it ?