[Bug c++/121950] New: -Wimplicit-fallthrough doesn't warn on bugs if there are declarations with vacuous initializations and non-trivial destructors

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121950

            Bug ID: 121950
           Summary: -Wimplicit-fallthrough doesn't warn on bugs if there
                    are declarations with vacuous initializations and
                    non-trivial destructors
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jakub at gcc dot gnu.org
  Target Milestone: ---

struct S { int a, b, c; ~S (); };

int i;

void
foo (int x)
{
  switch (x)
    {
    case 1:
      S s1;
      ++i;
    case 2:
      S s2;
      ++i;
      // FALLTHRU
    case 3:
      S s3;
      ++i;
      [[fallthrough]];
    default:
      S s4;
      ++i;
      break;
    }
}

doesn't warn about implicit fallthrough unless ~S (); is commented out.