[Bug c++/31899] New: [4.2/4.3 regression] -g and using declaration causing ICE in reference_to_unused

["zak at transversal dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following code, compiled with -g, causes an ICE on 4.2.0 RC3 (20070501) and
on my most recent 4.3.0 snapshot build (20070427):

---------------------
namespace NS {
  int x = 0;
  int &ref = x;
}

using NS::ref;
---------------------

test/ice.cc:6: internal compiler error: in reference_to_unused, at
dwarf2out.c:10128


This compiles cleanly with both 4.1.2 and 4.2.0 RC1 (20070316), suggesting that
this was exposed by a fairly recent patch.


Note that, in particular, this impacts code using Boost.Lambda in the following
style:

#include <boost/lambda/lambda.hpp>
using boost::lambda::_1;
...


-- 
           Summary: [4.2/4.3 regression] -g and using declaration causing
                    ICE in reference_to_unused
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: major
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: zak at transversal dot com
 GCC build triplet: x86_64_pc_linux_gnu
  GCC host triplet: x86_64-pc-linux-gnu
GCC target triplet: x86_64_pc_linux_gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31899