Tidy up macros

Author: markshannon

Include/cpython/object.h

@@ -448,8 +448,8 @@ without deallocating anything (and so unbounded call-stack depth is avoided).
 When the call stack finishes unwinding again, code generated by the END macro
 notices this, and calls another routine to deallocate all the objects that
 may have been added to the list of deferred deallocations.  In effect, a
-chain of N deallocations is broken into (N-1)/(_PyTrash_UNWIND_LEVEL-1) pieces,
-with the call stack never exceeding a depth of _PyTrash_UNWIND_LEVEL.
+chain of N deallocations is broken into (N-1)/(Py_TRASHCAN_HEADROOM-1) pieces,
+with the call stack never exceeding a depth of Py_TRASHCAN_HEADROOM.
 
 Since the tp_dealloc of a subclass typically calls the tp_dealloc of the base
 class, we need to ensure that the trashcan is only triggered on the tp_dealloc

Include/internal/pycore_object.h

@@ -600,7 +600,6 @@ _PyObject_GET_WEAKREFS_LISTPTR_FROM_OFFSET(PyObject *op)
     return (PyWeakReference **)((char *)op + offset);
 }
 
-
 // Fast inlined version of PyObject_IS_GC()
 static inline int
 _PyObject_IS_GC(PyObject *obj)

Objects/object.c

@@ -2686,8 +2686,6 @@ Py_ReprLeave(PyObject *obj)
 
 /* Trashcan support. */
 
-#define _PyTrash_UNWIND_LEVEL 50
-
 /* Add op to the gcstate->trash_delete_later list.  Called when the current
  * call-stack depth gets large.  op must be a currently untracked gc'ed
  * object, with refcount 0.  Py_DECREF must already have been called on it.
@@ -2723,7 +2721,7 @@ _PyTrash_thread_destroy_chain(PyThreadState *tstate)
                tups = [(tup,) for tup in tups]
            del tups
     */
-    assert(tstate->c_recursion_remaining > 100);
+    assert(tstate->c_recursion_remaining > Py_TRASHCAN_HEADROOM);
     tstate->c_recursion_remaining--;
     while (tstate->delete_later) {
         PyObject *op = tstate->delete_later;