[Bug c++/90995] New: [8/9/10 Regression] ICE in grokdeclarator, at cp/decl.c:12024

[gscfq@t-online.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90995

            Bug ID: 90995
           Summary: [8/9/10 Regression] ICE in grokdeclarator, at
                    cp/decl.c:12024
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gscfq@t-online.de
  Target Milestone: ---

Started with early versions of gcc-8 (before 20180525) :


$ cat z1.cc
bool f ()
{ enum : int a alignas; }


$ g++-7 -c z1.cc
$
$ g++-10-20190623 -c z1.cc
z1.cc: In function 'bool f()':
z1.cc:2:16: internal compiler error: in grokdeclarator, at cp/decl.c:12024
    2 | { enum : int a alignas; }
      |                ^~~~~~~
0x6411e6 grokdeclarator(cp_declarator const*, cp_decl_specifier_seq*,
decl_context, int, tree_node**)
        ../../gcc/cp/decl.c:12024
0x644fd6 start_decl(cp_declarator const*, cp_decl_specifier_seq*, int,
tree_node*, tree_node*, tree_node**)
        ../../gcc/cp/decl.c:5081
0x6c923c cp_parser_init_declarator
        ../../gcc/cp/parser.c:20378
0x6af10e cp_parser_simple_declaration
        ../../gcc/cp/parser.c:13546
0x6b0c49 cp_parser_declaration_statement
        ../../gcc/cp/parser.c:12976
0x6b16a7 cp_parser_statement
        ../../gcc/cp/parser.c:11305
0x6b2540 cp_parser_statement_seq_opt
        ../../gcc/cp/parser.c:11667
0x6b25ef cp_parser_compound_statement
        ../../gcc/cp/parser.c:11621
0x6c89c8 cp_parser_function_body
        ../../gcc/cp/parser.c:22645
0x6c89c8 cp_parser_ctor_initializer_opt_and_function_body
        ../../gcc/cp/parser.c:22696
0x6c8cd6 cp_parser_function_definition_after_declarator
        ../../gcc/cp/parser.c:28010
0x6c9993 cp_parser_function_definition_from_specifiers_and_declarator
        ../../gcc/cp/parser.c:27926
0x6c9993 cp_parser_init_declarator
        ../../gcc/cp/parser.c:20282
0x6af10e cp_parser_simple_declaration
        ../../gcc/cp/parser.c:13546
0x6cecf4 cp_parser_declaration
        ../../gcc/cp/parser.c:13243
0x6cf451 cp_parser_translation_unit
        ../../gcc/cp/parser.c:4699
0x6cf451 c_parse_file()
        ../../gcc/cp/parser.c:41489
0x78ec40 c_common_parse_file()
        ../../gcc/c-family/c-opts.c:1156