[Bug c++/76481] New: ICE on (invalid) redeclaration of extern variable as constexpr variable

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=76481

            Bug ID: 76481
           Summary: ICE on (invalid) redeclaration of extern variable as
                    constexpr variable
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ppalka at gcc dot gnu.org
  Target Milestone: ---

Test case:

extern int x;
constexpr int x = 5;

Error:

Segmentation fault
 constexpr int x = 5;
               ^
0xd821af crash_signal
        /home/patrick/code/gcc/gcc/toplev.c:335
0x74455b dump_simple_decl
        /home/patrick/code/gcc/gcc/cp/error.c:965
0x744af5 dump_decl
        /home/patrick/code/gcc/gcc/cp/error.c:1071
0x7502d2 decl_to_string
        /home/patrick/code/gcc/gcc/cp/error.c:2979
0x7502d2 cp_printer
        /home/patrick/code/gcc/gcc/cp/error.c:3559
0x150bf68 pp_format(pretty_printer*, text_info*)
        /home/patrick/code/gcc/gcc/pretty-print.c:643
0x15068a0 diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        /home/patrick/code/gcc/gcc/diagnostic.c:934
0x1506ba3 diagnostic_impl
        /home/patrick/code/gcc/gcc/diagnostic.c:1054
0x1507474 error(char const*, ...)
        /home/patrick/code/gcc/gcc/diagnostic.c:1254
0x678655 duplicate_decls(tree_node*, tree_node*, bool)
        /home/patrick/code/gcc/gcc/cp/decl.c:1686
0x85116c pushdecl_maybe_friend_1
        /home/patrick/code/gcc/gcc/cp/name-lookup.c:808
0x85116c pushdecl_maybe_friend(tree_node*, bool)
        /home/patrick/code/gcc/gcc/cp/name-lookup.c:1301
0x692483 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
        /home/patrick/code/gcc/gcc/cp/decl.c:5045
0x788881 cp_parser_init_declarator
        /home/patrick/code/gcc/gcc/cp/parser.c:18697
0x7894d7 cp_parser_simple_declaration
        /home/patrick/code/gcc/gcc/cp/parser.c:12485
0x7897fa cp_parser_block_declaration
        /home/patrick/code/gcc/gcc/cp/parser.c:12361
0x791e5e cp_parser_declaration
        /home/patrick/code/gcc/gcc/cp/parser.c:12258
0x790846 cp_parser_declaration_seq_opt
        /home/patrick/code/gcc/gcc/cp/parser.c:12137
0x790b78 cp_parser_translation_unit
        /home/patrick/code/gcc/gcc/cp/parser.c:4354
0x790b78 c_parse_file()
        /home/patrick/code/gcc/gcc/cp/parser.c:37667