[Bug c++/122112] New: internal compiler error: crash at cp/parser.cc:55180 with anonymous struct in function parameter containing auto

[attackerj1113 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122112

            Bug ID: 122112
           Summary: internal compiler error: crash at cp/parser.cc:55180
                    with anonymous struct in function parameter containing
                    auto
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Keywords: error-recovery, ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: attackerj1113 at gmail dot com
  Target Milestone: ---

The following code causes ICE on x86-64 gcc on trunk:


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void fun(
    struct
    {
        int xx;
        auto qq() { return xx; }
    } x
);

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Please check https://godbolt.org/z/hM9j9e4v3 for more info

Compiler Output:

<source>:4:5: error: types may not be defined in parameter types
    4 |     {
      |     ^
<source>:7:7: internal compiler error: in synthesize_implicit_template_parm, at
cp/parser.cc:55180
    7 |     } x
      |       ^
0x28cabd8 diagnostics::context::diagnostic_impl(rich_location*,
diagnostics::metadata const*, diagnostics::option_id, char const*,
__va_list_tag (*) [1], diagnostics::kind)
        ???:0
0x28bfb0b internal_error(char const*, ...)
        ???:0
0xb0063a fancy_abort(char const*, int, char const*)
        ???:0
0xd35b83 c_parse_file()
        ???:0
0xea5f99 c_common_parse_file()
        ???:0
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1