Using Clang: plugin enabled, configure problem

Hi all,

On Ubuntu 14.04, trying to use Clang, I built clang 3.8.0.

Then, on LO master, git-6240b6b while configuring with plug in enabled I 
got:

"
checking clang/AST/RecursiveASTVisitor.h presence... yes
configure: WARNING: clang/AST/RecursiveASTVisitor.h: present but cannot 
be compiled
configure: WARNING: clang/AST/RecursiveASTVisitor.h:     check for 
missing prerequisite headers?
configure: WARNING: clang/AST/RecursiveASTVisitor.h: see the Autoconf 
documentation
configure: WARNING: clang/AST/RecursiveASTVisitor.h:     section 
"Present But Cannot Be Compiled"
configure: WARNING: clang/AST/RecursiveASTVisitor.h: proceeding with the 
compiler's result
checking for clang/AST/RecursiveASTVisitor.h... no
configure: error: Cannot find Clang headers to build compiler plugins.
Error running configure at ./autogen.sh line 281.
Reading autogen.lastrun. Please rename it to autogen.input to avoid this 
message.
configure: WARNING: clang/AST/RecursiveASTVisitor.h: present but cannot 
be compiled
configure: WARNING: clang/AST/RecursiveASTVisitor.h:     check for 
missing prerequisite headers?
configure: WARNING: clang/AST/RecursiveASTVisitor.h: see the Autoconf 
documentation
configure: WARNING: clang/AST/RecursiveASTVisitor.h:     section 
"Present But Cannot Be Compiled"
configure: WARNING: clang/AST/RecursiveASTVisitor.h: proceeding with the 
compiler's result
configure: error: Cannot find Clang headers to build compiler plugins.
Error running configure at /srv5/git/LO/lo-serf/autogen.sh line 281.
make: *** [/srv5/git/LO/lo-serf/config_host.mk] Error 2
"

examining config.log I saw this:

"
| /* end confdefs.h.  */
|
| int
| main ()
| {
|  return 0;
|   ;
|   return 0;
| }
configure:17414: result: no
configure:17448: checking clang/AST/RecursiveASTVisitor.h usability
configure:17448: clang++ -c   -std=gnu++11 -I/usr/include 
-I/usr/tools/clang/include -D__STDC_CONSTANT_MACROS 
-D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS conftest.cpp >&5
In file included from conftest.cpp:117:
In file included from /usr/local/include/clang/AST/RecursiveASTVisitor.h:17:
In file included from /usr/local/include/clang/AST/Attr.h:17:
In file included from /usr/local/include/clang/AST/AttrIterator.h:17:
In file included from /usr/local/include/clang/Basic/LLVM.h:22:
In file included from /usr/include/llvm/Support/Casting.h:19:
In file included from /usr/include/llvm/Support/type_traits.h:17:
/usr/bin/../lib/gcc/x86_64-linux-gnu/4.8/../../../../include/c++/4.8/type_traits:549:38: 
error: incomplete type 'clang::ASTContext' used in type trait expression
    : public integral_constant<bool, __is_abstract(_Tp)>
                                     ^
"

full config.log here:
<http://pastebin.com/URgn8ChJ>

What's the error?

Thanks for any help.

--
Kind Regards,
Giuseppe Castagno
Acca Esse http://www.acca-esse.eu
giuseppe.castagno at acca-esse.eu