Is this a bug?

[Andrew Haley]

Here in Thumb2_Return I see:

void Thumb2_Return(Thumb2_Info *jinfo, unsigned opcode, int bci, int stackdepth)
{
...
  if (jinfo->method->is_synchronized()) {
    unsigned loc_success1, loc_success2, loc_failed, loc_retry, loc_exception;
    unsigned loc_illegal_monitor_state;
    Thumb2_Flush(jinfo);
//    Thumb2_save_locals(jinfo);

I'm wondering if Thumb2_save_locals should be commented out because if
we hit a safepoint we'll be processing stale versions of locals.  Is
that potentially a bug, or not?  I think it might be, because there
might be a new version of a local that gets missed.  But so what?  If
it only exists as a local, and the frame is about to be dropped, it
doesn't matter, it's unreachable anyway.  The GC will process stale
versions of the locals, which might mean that some old objects will be
kept alive for longer than they should, but that doesn't really
matter.

Is there any reason to save locals at a return statement, then?
I think not, but it doesn't feel right to have the GC scanning
stale data.  Thoughts?

Andrew.