[Bug c++/101879] New: Broken diagnostic: 'vec_perm_expr' not supported by dump_expr<expression error>

[reichelt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101879

            Bug ID: 101879
           Summary: Broken diagnostic: 'vec_perm_expr' not supported by
                    dump_expr<expression error>
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: reichelt at gcc dot gnu.org
  Target Milestone: ---

The following invalid code snippet produces a garbled diagnostic
('vec_perm_expr' not supported by dump_expr<expression error>):

============================================================================
template<typename T>
auto foo(const T& x) -> decltype(__builtin_shuffle(x,x)) { return }
============================================================================

bug.cc: In function 'decltype ('vec_perm_expr' not supported by
dump_expr<expression error>) foo(const T&)':
bug.cc:6:67: error: expected primary-expression before '}' token
    6 | auto foo(const T& x) -> decltype(__builtin_shuffle(x,x)) { return }
      |                                                                   ^
bug.cc:6:66: error: expected ';' before '}' token
    6 | auto foo(const T& x) -> decltype(__builtin_shuffle(x,x)) { return }
      |                                                                  ^~
      |                                                                  ;