/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.149 2003/03/24 14:46:53 simonmar Exp $
+ * $Id: GC.c,v 1.150 2003/03/24 15:33:25 simonmar Exp $
*
* (c) The GHC Team 1998-2003
*
selector_loop:
+ // We don't want to end up in to-space, because this causes
+ // problems when the GC later tries to evacuate the result of
+ // eval_thunk_selector(). There are various ways this could
+ // happen:
+ //
+ // - following an IND_STATIC
+ //
+ // - when the old generation is compacted, the mark phase updates
+ // from-space pointers to be to-space pointers, and we can't
+ // reliably tell which we're following (eg. from an IND_STATIC).
+ //
+ // So we use the block-descriptor test to find out if we're in
+ // to-space.
+ //
if (Bdescr((StgPtr)selectee)->flags & BF_EVACUATED) {
- SET_INFO(p, info_ptr);
- return NULL;
+ goto bale_out;
}
info = get_itbl(selectee);
ASSERT(field < (StgWord32)(info->layout.payload.ptrs +
info->layout.payload.nptrs));
+ // ToDo: shouldn't we test whether this pointer is in
+ // to-space?
return selectee->payload[field];
case IND:
case IND_PERM:
case IND_OLDGEN:
case IND_OLDGEN_PERM:
+ case IND_STATIC:
selectee = ((StgInd *)selectee)->indirectee;
goto selector_loop;
// leaks by evaluating this selector thunk anyhow.
break;
- case IND_STATIC:
- // We can't easily tell whether the indirectee is into
- // from or to-space, so just bail out here.
- break;
-
case THUNK_SELECTOR:
{
StgClosure *val;
(int)(info->type));
}
+bale_out:
// We didn't manage to evaluate this thunk; restore the old info pointer
SET_INFO(p, info_ptr);
return NULL;