[Bug c++/107422] New: [12/13 Regression] ICE in lvalue_kind, at cp/tree.cc:293

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107422

            Bug ID: 107422
           Summary: [12/13 Regression] ICE in lvalue_kind, at
                    cp/tree.cc:293
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Started with r12 before 20210502 :
(gcc configured with --enable-checking=yes)


$ cat z1.cc
typedef decltype (__builtin_trap) t;
template <int> struct s;
union
{
  template <int a> using b = decltype (t () (s <a> {}));
  template <int a> b <a> get ();
};  // } u;


$ g++-13-20221023 -c z1.cc -fno-pretty-templates
z1.cc:5:26: error: 'template<int a> using<unnamed union>::b = decltype
(t()(s<a>{}))' invalid; an anonymous union may only have public non-static data
members [-fpermissive]
    5 |   template <int a> using b = decltype (t () (s <a> {}));
      |                          ^
'
Segmentation fault
    7 | };  // } u;
      | ^
0x11d0e4f crash_signal
        ../../gcc/toplev.cc:314
0xb15510 lvalue_kind(tree_node const*)
        ../../gcc/cp/tree.cc:293
0xae9fa7 finish_decltype_type(tree_node*, bool, int)
        ../../gcc/cp/semantics.cc:11488
0xb271af strip_typedefs(tree_node*, bool*, unsigned int)
        ../../gcc/cp/tree.cc:1788
0x91ae45 dump_type
        ../../gcc/cp/error.cc:538
0x91a6fc dump_type_prefix
        ../../gcc/cp/error.cc:981
0x92578d dump_function_decl
        ../../gcc/cp/error.cc:1804
0x9287f6 decl_to_string
        ../../gcc/cp/error.cc:3297
0x9287f6 cp_printer
        ../../gcc/cp/error.cc:4471
0x2202490 pp_format(pretty_printer*, text_info*)
        ../../gcc/pretty-print.cc:1475
0x21e13c0 diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        ../../gcc/diagnostic.cc:1548
0x21e1b0a diagnostic_impl
        ../../gcc/diagnostic.cc:1712
0x21e224a permerror(unsigned int, char const*, ...)
        ../../gcc/diagnostic.cc:1979
0x8c30e7 fixup_anonymous_aggr(tree_node*)
        ../../gcc/cp/decl.cc:5194
0x8ea67c shadow_tag(cp_decl_specifier_seq*)
        ../../gcc/cp/decl.cc:5498
0xa011c9 cp_parser_simple_declaration
        ../../gcc/cp/parser.cc:15422
0xa35d9b cp_parser_declaration
        ../../gcc/cp/parser.cc:14970
0xa368b8 cp_parser_translation_unit
        ../../gcc/cp/parser.cc:5076
0xa368b8 c_parse_file()
        ../../gcc/cp/parser.cc:48860
0xbcef21 c_common_parse_file()
        ../../gcc/c-family/c-opts.cc:1247