[Bug c++/96137] New: [11 Regression] GCC hang on in invalid function definition

[haoxintu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96137

            Bug ID: 96137
           Summary: [11 Regression] GCC hang on in invalid function
                    definition
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: haoxintu at gmail dot com
  Target Milestone: ---

Hi, all.

This simple code makes GCC-trunk hang on. The memory seems ok, only with
endless compiling.

$cat bug.cc
void a () { .operator b }

$g++ bug.cc
bug.cc: In function ‘void a()’:
bug.cc:1:13: error: expected primary-expression before ‘.’ token
    1 | void a () { .operator b }
      |             ^
...

I tested the trunk version:
GCC version 11.0.0 20200708 (experimental) (GCC) 

The GCC-10 or GCC-9 compiles this as normal. I guess this is a regression
issue?

Thanks,
Haoxin