--enable-clang fails with against 3.0-6ubuntu3

[wting]

I'm on Ubuntu 12.04.1 LTS with clang installed. This seems like a possible regression of #800.

$ ../configure --enable-clang --enable-valgrind --disable-docs --prefix=/opt && make -j4
configure: looking for configure programs
configure: found cmp
configure: found mkdir
configure: found printf
configure: found cut
configure: found head
configure: found grep
configure: found xargs
configure: found cp
configure: found find
configure: found uname
configure: found date
configure: found tr
configure: found sed
configure: inspecting environment
configure: recreating config.tmp
configure:
configure: processing /home/ting/code/rust/configure args
configure:
configure: CFG_ENABLE_VALGRIND  := 1
configure: CFG_DISABLE_DOCS     := 1
configure: CFG_ENABLE_CLANG     := 1
configure: CFG_PREFIX           := /opt
configure: CFG_LOCAL_RUST_ROOT  := /usr/local
configure: CFG_LLVM_ROOT        :=
configure: CFG_HOST_TRIPLE      := x86_64-unknown-linux-gnu
configure: CFG_TARGET_TRIPLES   := x86_64-unknown-linux-gnu
configure:
configure: validating /home/ting/code/rust/configure args
configure:
configure:
configure: looking for build programs
configure:
configure: CFG_PERL             := /usr/bin/perl
configure: CFG_CURL             := /usr/bin/curl (7.22.0)
configure: CFG_PYTHON           := /usr/bin/python2.7
configure: CFG_GIT              := /usr/bin/git (1.7.9.5)
configure: CFG_CLANG            := /usr/bin/clang++ (3.0-6ubuntu3)
configure: CFG_GCC              := /usr/lib/ccache/gcc (4.6.3-1ubuntu5))
configure: CFG_LD               := /usr/bin/ld (2.22)
configure: CFG_LLVM_CONFIG      :=
configure: CFG_VALGRIND         := /usr/bin/valgrind (3.7.0)
configure: CFG_PERF             :=
configure: CFG_ISCC             :=
configure: CFG_LLNEXTGEN        :=
configure: CFG_PANDOC           := /usr/bin/pandoc (1.9.1.1)
configure: CFG_PDFLATEX         := /usr/bin/pdflatex (3.1415926-1.40.10-2.2)
configure: CFG_XETEX            := /usr/bin/xetex (3.1415926-2.2-0.9995.2)
configure: CFG_LUATEX           := /usr/bin/luatex (0.70.1-2011120612)
configure: CFG_NODE             :=
configure: CFG_PAXCTL           :=
configure: CFG_ZCAT             := /bin/zcat (1.4)
configure:
configure: GRSecurity: no
configure:
configure: error: bad CLANG version: 3.0-6ubuntu3, need >=3.0svn
$ 

[wting]

I patched configure and tried compiling v0.5 with clang v3.0-6ubuntu3 but it's failing with the following errors:

compile: rt/x86_64-unknown-linux-gnu/rust_port.o
compile: rt/x86_64-unknown-linux-gnu/rust_upcall.o
In file included from /home/ting/code/rust/src/rt/rust_upcall.cpp:22:
In file included from /home/ting/code/rust/src/rt/rust_unwind.h:24:
/usr/lib/gcc/x86_64-linux-gnu/4.6/include/unwind.h:43:46: error: unknown machine mode
      '__unwind_word__'
typedef unsigned _Unwind_Word __attribute__((__mode__(__unwind_word__)));
                                             ^
/usr/lib/gcc/x86_64-linux-gnu/4.6/include/unwind.h:44:45: error: unknown machine mode
      '__unwind_word__'
typedef signed _Unwind_Sword __attribute__((__mode__(__unwind_word__)));
                                            ^
In file included from /home/ting/code/rust/src/rt/rust_upcall.cpp:22:
/home/ting/code/rust/src/rt/rust_unwind.h:33:14: error: typedef redefinition with different
      types ('void' vs '_Unwind_Exception')
typedef void _Unwind_Exception;
             ^
/usr/lib/gcc/x86_64-linux-gnu/4.6/include/unwind.h:85:8: note: previous definition is here
struct _Unwind_Exception
       ^
3 errors generated.
make: *** [rt/x86_64-unknown-linux-gnu/rust_upcall.o] Error 1
make: *** Waiting for unfinished jobs....
extracting rust-stage0/bin/rustc
extracting rust-stage0/lib/libcore-c3ca5d77d81b46c1-0.5.so
extracting rust-stage0/lib/libstd-4782a756585a81-0.5.so
extracting rust-stage0/lib/librustc-c84825241471686d-0.5.so
extracting rust-stage0/lib/libsyntax-84efebcb12c867a2-0.5.so
extracting rust-stage0/lib/librustrt.so
extracting rust-stage0/lib/librustllvm.so

I'm going to upgrade to a newer version of clang to see if it's a compiler incompatibility or rust build error.

[catamorphism]

Fixed in bb51a84