[Bug c++/100172] New: ICE with "concept concept" keyword in struct

[Bug c++/100172] New: ICE with "concept concept" keyword in struct

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100172

            Bug ID: 100172
           Summary: ICE with "concept concept" keyword in struct
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

The following only shows a warning, which may be related to fixed PR97536.

struct {
  concept concept;
};


<source>:2:3: warning: C++20 concept definition syntax is 'concept <name> =
<expr>'
    2 |   concept concept;
      |   ^~~~~~~
<source>:2:11: warning: C++20 concept definition syntax is 'concept <name> =
<expr>'
    2 |   concept concept;
      |           ^~~~~~~
'
Segmentation fault
0x1d030c9 internal_error(char const*, ...)
        ???:0
0x1d1eb4b pp_format(pretty_printer*, text_info*)
        ???:0
0x1d01c4a diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        ???:0
0x1d049e6 error_at(rich_location*, char const*, ...)
        ???:0
0x8e261d c_parse_file()
        ???:0
0xa62752 c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.

[Bug c++/100172] ICE with "concept concept" keyword in struct

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100172

--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> ---
And gcc-trunk accepts this non-sense snippet:

https://godbolt.org/z/PbTa55eTx

void f(auto) {
  struct S {
    concept enum E {};
  };
  []() requires S::E {};
}

template void f(int);

[Bug c++/100172] ICE with "concept concept" keyword in struct

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100172

--- Comment #2 from 康桓瑋 <hewillk at gmail dot com> ---
The struct bit is a red herring. It can be boiled down to just two concept
keywords:

https://godbolt.org/z/sW7vr3sso

concept concept;

<source>:1:1: warning: C++20 concept definition syntax is 'concept <name> =
<expr>'
    1 | concept concept;
      | ^~~~~~~
<source>:1:9: warning: C++20 concept definition syntax is 'concept <name> =
<expr>'
    1 | concept concept;
      |         ^~~~~~~
'
Segmentation fault
0x1d030c9 internal_error(char const*, ...)
        ???:0
0x1d1eb4b pp_format(pretty_printer*, text_info*)
        ???:0
0x1d01c4a diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        ???:0
0x1d049e6 error_at(rich_location*, char const*, ...)
        ???:0
0x8e261d c_parse_file()
        ???:0
0xa62752 c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.

[Bug c++/100172] ICE with "concept concept" keyword

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100172

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
                 CC|                            |mpolacek at gcc dot gnu.org
   Last reconfirmed|                            |2021-04-21
             Status|UNCONFIRMED                 |NEW

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed.

[Bug c++/100172] ICE with "concept concept" keyword

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100172

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |needs-bisection

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Seems have been fixed for GCC 12.1.0.