Merge of descr-branch back into trunk.
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 4aa38d5..18cece8 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -236,7 +236,13 @@
#define PyObject_GC_Fini(op)
#define PyObject_AS_GC(op) (op)
#define PyObject_FROM_GC(op) (op)
-
+#define PyType_IS_GC(t) 0
+#define PyObject_IS_GC(o) 0
+#define PyObject_AS_GC(o) (o)
+#define PyObject_FROM_GC(o) (o)
+#define PyType_BASICSIZE(t) ((t)->tp_basicsize)
+#define PyType_SET_BASICSIZE(t, s) ((t)->tp_basicsize = (s))
+
#else
/* Add the object into the container set */
@@ -269,6 +275,13 @@
/* Get the object given the PyGC_Head */
#define PyObject_FROM_GC(g) ((PyObject *)(((PyGC_Head *)g)+1))
+/* Calculate tp_basicsize excluding PyGC_HEAD_SIZE if applicable */
+#define PyType_BASICSIZE(t) (!PyType_IS_GC(t) ? (t)->tp_basicsize : \
+ (t)->tp_basicsize - PyGC_HEAD_SIZE)
+#define PyType_SET_BASICSIZE(t, s) (!PyType_IS_GC(t) ? \
+ ((t)->tp_basicsize = (s)) : \
+ ((t)->tp_basicsize = (s) + PyGC_HEAD_SIZE))
+
extern DL_IMPORT(void) _PyGC_Dump(PyGC_Head *);
#endif /* WITH_CYCLE_GC */