[Bug c++/42057] New: [4.5 Regression] ICE with invalid parameter of virtual function

["reichelt at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

The following invalid testcase triggers an ICE on trunk:

====================================
struct A;

struct B
{
  virtual B* foo(A);
};

struct C : virtual B
{
  virtual C* foo(A) { return 0; }
};

C c;
====================================

bug.cc: In member function 'virtual C* C::foo(A)':
bug.cc:10:14: error: '<anonymous>' has incomplete type
bug.cc:1:8: error: forward declaration of 'struct A'
bug.cc: In member function 'C* C::_ZTch0_v0_n16_N1C3fooE1A(A)':
bug.cc:13:4: internal compiler error: tree check: expected class 'type', have
'exceptional' (error_mark) in create_tmp_var, at gimplify.c:504
Please submit a full bug report, [etc.]

When the code snippet is compiles with "-Wall" then the ICE happens in a
different place (the rest of the error message is identical):

bug.cc:13:4: internal compiler error: tree check: expected class 'type', have
'exceptional' (error_mark) in operand_equal_p, at fold-const.c:3182


-- 
           Summary: [4.5 Regression] ICE with invalid parameter of virtual
                    function
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code, error-recovery, monitored
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: reichelt at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42057