[Bug c++/79580] New: [5/6/7 Regression] ICE in nested_anon_class_index, at cp/mangle.c:1604

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79580

            Bug ID: 79580
           Summary: [5/6/7 Regression] ICE in nested_anon_class_index, at
                    cp/mangle.c:1604
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: hubicka at ucw dot cz, jason at gcc dot gnu.org
  Target Milestone: ---

Following test-case:

$ cat ice.C
class a
{
  static const double b;
};
const double a::b ((union { double c; }){}.c);

$ gcc ice.C -flto -std=c++98
ice.C:5:27: internal compiler error: in nested_anon_class_index, at
cp/mangle.c:1604
 const double a::b ((union { double c; }){}.c);
                           ^
0x7622cd nested_anon_class_index
        ../../gcc/cp/mangle.c:1604
0x7622cd write_unnamed_type_name
        ../../gcc/cp/mangle.c:1618
0x7622cd write_unqualified_name
        ../../gcc/cp/mangle.c:1380
0x7691f7 write_nested_name
        ../../gcc/cp/mangle.c:1077
0x7649b5 write_name
        ../../gcc/cp/mangle.c:976
0x76537c write_class_enum_type
        ../../gcc/cp/mangle.c:2781
0x76537c write_type
        ../../gcc/cp/mangle.c:2195
0x769938 mangle_decl_string
        ../../gcc/cp/mangle.c:3759
0x769a3b get_mangled_id
        ../../gcc/cp/mangle.c:3783
0x769a3b mangle_decl(tree_node*)
        ../../gcc/cp/mangle.c:3853
0xdaa00e decl_assembler_name(tree_node*)
        ../../gcc/tree.c:671
0xdaa00e assign_assembler_name_if_needed(tree_node*)
        ../../gcc/tree.c:5920
0xdab514 free_lang_data_in_cgraph
        ../../gcc/tree.c:5969
0xdab514 free_lang_data
        ../../gcc/tree.c:6006
0xdab514 execute
        ../../gcc/tree.c:6055