[Bug c++/97762] New: [11 Regression] ICE: Segmentation fault (in warn_about_ambiguous_parse)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97762

            Bug ID: 97762
           Summary: [11 Regression] ICE: Segmentation fault (in
                    warn_about_ambiguous_parse)
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

g++-11.0.0-alpha20201108 snapshot (g:b642fca1c31b2e2175e0860daf32b4ee0d918085)
ICEs when compiling gcc/testsuite/gcc.c-torture/execute/nestfunc-3.c:

% g++-11.0.0 -c gcc/testsuite/gcc.c-torture/execute/nestfunc-3.c
gcc/testsuite/gcc.c-torture/execute/nestfunc-3.c: In function 'int main()':
gcc/testsuite/gcc.c-torture/execute/nestfunc-3.c:12:32: internal compiler
error: Segmentation fault
   12 |   long nested_0 (long a, long b)
      |                                ^
0x10302ff crash_signal
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/toplev.c:330
0x9bf80b warn_about_ambiguous_parse
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:20656
0x9f6199 cp_parser_init_declarator
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:20943
0x9d56de cp_parser_simple_declaration
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:13892
0x9d768c cp_parser_declaration_statement
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:13332
0x9d835f cp_parser_statement
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:11578
0x9d943d cp_parser_statement_seq_opt
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:11944
0x9d9518 cp_parser_compound_statement
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:11894
0x9f2524 cp_parser_function_body
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:23410
0x9f2524 cp_parser_ctor_initializer_opt_and_function_body
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:23461
0x9f5dc9 cp_parser_function_definition_after_declarator
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:29355
0x9f6e19 cp_parser_function_definition_from_specifiers_and_declarator
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:29271
0x9f6e19 cp_parser_init_declarator
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:20983
0x9d56de cp_parser_simple_declaration
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:13892
0xa02266 cp_parser_declaration
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:13591
0xa028d0 cp_parser_translation_unit
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:4796
0xa028d0 c_parse_file()
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/cp/parser.c:44444
0xb2621d c_common_parse_file()
       
/var/tmp/portage/sys-devel/gcc-11.0.0_alpha20201108/work/gcc-11-20201108/gcc/c-family/c-opts.c:1196