[Bug c++/71236] New: [5/6/7 Regression] ICE on invalid code

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71236

            Bug ID: 71236
           Summary: [5/6/7 Regression] ICE on invalid code
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

Hello.

Following snippet produces stack-overflow in:
#0  0x000000000055c39c in push_inner_scope_r (outer=0x7ffff69dd8e8, 
    outer@entry=<error reading variable: DWARF-2 expression error: Loop
detected (257).>, inner=0x7ffff688b000)
    at ../../gcc/cp/name-lookup.c:2848

$ cat tc.ii
struct T
{
};

class A {
  template <int> struct COMTypeInfo;
};

namespace
{
  class B : A {};
  template <int> struct B::COMTypeInfo {}
}

$ g++ tc.ii
g++: internal compiler error: Segmentation fault (program cc1plus)

Martin